علوم زیستی دریا
Zohreh Ebrahimi; Giti Forghani Tehrani; Abd-al-Reza Kaboli
Abstract
The Ziarat River is one of the tributaries of the Qarah-su catchment, and a part of this river flows through Gorgan City. In order to investigate the environmental hydrogeochemistry of the river, 11 water samples were collected. Physicochemical parameters, the concentrations of major ions and metals, ...
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The Ziarat River is one of the tributaries of the Qarah-su catchment, and a part of this river flows through Gorgan City. In order to investigate the environmental hydrogeochemistry of the river, 11 water samples were collected. Physicochemical parameters, the concentrations of major ions and metals, as well as the biological parameters were analyzed. The obtained results show that pH and EC of the water samples vary from 7.2 to 7.9, and from 701 to 1422 μS/cm, respectively. The highest pH and EC values were observed near the discharging point of cowshed effluents and the Ziarat hot spring, respectively. On the basis of hydrogeochemical studies, the chemical composition of water samples is mainly controlled by the dissolution process. The water type changed from Ca-SO4 in upstream to Na-Cl in downstream, probably because of natural and anthropogenic factors. Regarding the major ion concentrations, all water samples are in the acceptable range for drinking usage. Based on the Wilcox diagram, and regarding the calculated residual sodium carbonate and sodium percentage values, the studied water samples are suitable for drinking and agricultural purposes; however, regarding the values of magnesium hazard index, most of the samples are not suitable for agricultural usage. Metal pollution indices show that studied samples are highly polluted, especially those samples which were collected at the wastewater discharging points. The values of dissolved oxygen in all samples are in the permissible limits. However, in some stations, BOD and COD levels are higher than permissible values, and the highest amount of these parameters is observed near the discharging point of cowshed and agricultural effluents. All water samples are microbially polluted, and the lowest microbial pollution is observed in upstream stations. The values of Water Quality Indices indicate that all studied samples are classified as low and very low quality.
علوم انسانی دریا
Mohammad Amin Kouhbor; Homayoun Yousefi
Abstract
The aim of this article is to examine the relationship between economic growth, international trade and marine freight transportation. For this reason, annual data for marine transport and economic growth determinants is used, during the period of 1978 to 2017 with the application of Auto Regressive ...
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The aim of this article is to examine the relationship between economic growth, international trade and marine freight transportation. For this reason, annual data for marine transport and economic growth determinants is used, during the period of 1978 to 2017 with the application of Auto Regressive Distributed Lag model to control the dynamics structure of the system in both of growth and marine transportation models. Results indicate an investment in marine transportation sector cause economic growth and also, marine transportation has a significant effect on International trade. Based on the results, its proposed to increase marine transport facilities in order to improve trade balance.
علوم انسانی دریا
Mohammad Amin Kouhbor; Homayoun Yousefi; Mohammad Esmaeil Doust; Arash Amraei
Abstract
The purpose of this present study was to identify the factors affecting the development of the maritime tourism industry in line with the economic growth of the ports of Khorramshahr and Abadan and its effect on attracting tourists in Arvand Free Zone. On the other hand, citing the research objective, ...
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The purpose of this present study was to identify the factors affecting the development of the maritime tourism industry in line with the economic growth of the ports of Khorramshahr and Abadan and its effect on attracting tourists in Arvand Free Zone. On the other hand, citing the research objective, ranking the factors affecting the development of the maritime tourism industry, will increase the income of the ports and maritime organizations of Abadan and Khorramshahr, Arvand Free Zone, as well as creating job opportunities in Khuzestan Province. The method of this research is applied in terms of its purpose and in terms of descriptive-survey nature which is conducted by interviewing, observing, studying and ... with a deductive approach to identify influential factors. On the other hand, in the quantitative part of the research, the analysis has been carried out. Data were analyzed by using SPSS and LISREL software based on T-test and structural equations model. Based on the results, natural variables of other variables were more effective than those with T-statistic 14.84 and impact factor, 0.85, has a significant amount. This value is considered strong in terms of the severity of the effect, since it is more than 70%. On the other hand, the variable of political factors, with the value of t statistic, is 9.71, and the coefficient of influence is 0.59, and the effect of average intensity has the least effect on attracting tourists in Arvand Free Zone.
The method of this research is applied in terms of its purpose and in terms of descriptive-survey nature which is conducted by interviewing, observing, studying and ... with a deductive approach to identify influential factors. On the other hand, in the quantitative part of the research, the analysis has been carried out. Data were analyzed by using SPSS and LISREL software based on the T-test and structural equations model. Based on the results, natural variables of other variables were more effective than those with T-statistic 14.84 and impact factor, 0.85, has a significant amount. This value is considered strong in terms of the severity of the effect since it is more than 70%. On the other hand, the variable of political factors, with the value of t statistic, is 9.71, and the coefficient of influence is 0.59, and the effect of average intensity has the least effect on attracting tourists in Arvand Free Zone.
علوم زیستی دریا
Seyed Hashem Beitalavi; Hamid Mohammadiazarm; Milad Maniat
Abstract
In this study, in order to use prebiotics as one of the best solutions to maintain the health of farmed aquatic animals and increase their resistance against pathogenic instead of antibiotics, the effects of different levels of isomaltooligosaccharide (ISO) prebiotics on growth performance, biochemical ...
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In this study, in order to use prebiotics as one of the best solutions to maintain the health of farmed aquatic animals and increase their resistance against pathogenic instead of antibiotics, the effects of different levels of isomaltooligosaccharide (ISO) prebiotics on growth performance, biochemical body composition, and mucosal immunity of red tilapia (Oreochromis mossambicus × Oreochromis niloticus) were investigated. For this purpose, 300 pieces of red tilapia were randomly divided into 15 aquariums with capacity of 100 L in 5 treatments with 3 replications. Experimental treatments as described in the control treatment without ISO, first treatment: the diet containing 2.5 g/kg of ISO, second treatment: the diet containing 5 g/kg of ISO, third treatment: the diet containing 10 g/kg of ISO, and fourth treatment: the diet containing 20 g/kg of ISO. Therefore, the fish were fed ad libitum three times per day for 8 weeks. The result showed that the used prebiotic ISO improves growth and nutritional performance, body biochemical composition, and some biochemical parameters of blood serum in red tilapia. In addition, the mucosal immunity indices of fish were improved under the effect of diets containing prebiotic ISO. Among the experimental treatments, the third treatment had the best performance in terms of final weight (13.4±0.31g), food conversion factor (1.02±0.02), percentage of protein content of body (13.49±0.25), blood serum protein (4.66±0.10 gr/dl), globulin (3.23±0.02 g/dl), and mucus immune indices such as mucus protein (20.29±1.05 mg/ml), immunoglobulin (62.0±0.32 mg/ml) 7), and lysozyme activity (9.14±0.24 u/ml). Therefore, it could be concluded that the use of ISO prebiotics at the level of 1% can have beneficial effects on performance of juveniles red tilapia fish.
علوم زیستی دریا
Rezvan Khavari; Fatemeh Mosavi
Abstract
Abkharvar Behbahan channel is 7 km long in Behbahan Plain located in arid and semi-arid area and it is limited in terms of water resources, therefore it is very important to preserve the quality of water resources and prevent them from being polluted. In order to investigate the pollution level of Abkharvar ...
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Abkharvar Behbahan channel is 7 km long in Behbahan Plain located in arid and semi-arid area and it is limited in terms of water resources, therefore it is very important to preserve the quality of water resources and prevent them from being polluted. In order to investigate the pollution level of Abkharvar Cannel, sampling operations were carried out from 6 locations in the studied area. Water samples to determine the concentration of heavy elements As, Fe, Pb, Se, Zn, Mn, Cr, anions Cl-, SO42-, NO3-, CO3-, HCO3-, and cations Ca2+, Na+, Mg2+, K+, and important water quality parameters including Ph, EC and TDS were analyzed by ICP-OES, FAES, OAS, titration, drying and conductivity methods. The pH levels in all samples are within the WHO standard and the standard of wastewater discharged to surface water and agricultural uses. The concentration of SO42- anion and Mg2+, Na+, Ca2+ cations and important water quality factors including EC, TDS in the sample taken from the Maroon River (S6) is higher than the WHO drinking water limit. Geochemical data show that the water chemistry in the region is strongly influenced by factors such as the entry of industrial and human wastewater into this chanel, as well as the dissolution of carbonate rocks and evaporative sediments containing gypsum, calcite, and halite minerals along the Abkharvar Behbahan channel.
علوم زیستی دریا
Maryam Hasani; Mahin Rigi; Moazameh Kordjazi; Shirin Hasani
Abstract
Omega-3 fatty acids play a role in achieving optimal health and protection against various diseases. Although the instability and oxidation of its essential fatty acids have limited its use in food products. Among the strategies used to avoid these challenges, the encapsulation method has been the most ...
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Omega-3 fatty acids play a role in achieving optimal health and protection against various diseases. Although the instability and oxidation of its essential fatty acids have limited its use in food products. Among the strategies used to avoid these challenges, the encapsulation method has been the most successful method. Therefore, the present study was performed with the aim of improving the stability of fish oil with encapsulation method and producing a useful product. In this research, the encapsulation of fish oil with a ratio of 3:1 (oil: coating) was done with malt dextrin, sodium casein ate, protein whey concentrates and modified starch (HICAP) by freeze drying. Yogurt enriched with encapsulated fish oil powder was produced and the physicochemical and sensory properties of the product were evaluated. The results showed that the particle size, particle dispersion index and encapsulation efficiency of the capsules were 0.85μm, 0.29 and 90%, respectively. Also, the results showed that the syneresis of yogurt enriched with microcapsules was lower and the water holding capacity was higher than the control and sample enriched with non-encapsulated fish oil. The increase of peroxide values in yogurt enriched with encapsulated fish oil had a slower trend than yogurt enriched with non-encapsulated oil. In all treatments, pH decreased and acidity increased. The sensory evaluation of the treatments revealed that the quality parameters of the yogurt treatments decreased during storage, and the yogurt treatments enriched with microencapsulated oil and the control treatment did not show any significant difference in terms of overall acceptance.
علوم زیستی دریا
Sahar Ahmadvand; Solmaz Shirali; Nasrin Sakhaei; Babak Doustshenas
Abstract
The Unionidae family is the most abundant family among freshwater bivalves which belongs to the Unionida order. Considering the nutritional, economic and environmental importance of bivalve molluscs, as well as the lack of information related to freshwater mussels of the Unionida order, especially the ...
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The Unionidae family is the most abundant family among freshwater bivalves which belongs to the Unionida order. Considering the nutritional, economic and environmental importance of bivalve molluscs, as well as the lack of information related to freshwater mussels of the Unionida order, especially the species belonging to the Unionidae family, as well as their global risk and concidering the importance of the ovary and the testis as an important organ of reproduction and survival and since histological studies are the most accurate method in determining the stages of the gonadal cycle, this research was conducted with the aim of investigating the histology of oogenesis and spermatogenesis in Unio tigridis of the Karun River. Sampling was done seasonally. For this purpose, the studied species after catching in every season were transferred to the histological laboratory, then they were biometrically identified using valid identification books and keys. After dissection, small pieces of gonads were separated and after tissue passage, they were examined histologically and histometrically. The results of the histological studies of the gonads showed that this species is often heterosexual. The results of the histological studies of gonads showed that out of 41 oysters in this study, there was only one hermaphrodite, and testicular and ovarian tissue were simultaneously observed in the gonad tissue. The ovary was asynchronous type because, at any time, all types of follicles in different stages of development (oogonia, previtellogenic oocytes, vitellogenic oocytes) were visible in the ovaries. The highest rate of development and maturation of both male and female gonads was observed in spring. It seems that the main breeding time of Unio tigridis species in the Karun River in the study area is in spring.
علوم انسانی دریا
Aryan Setareh Tabrizi; Ali Mohtashami; Hamed Rahmani
Abstract
Nowadays, more than 90% of the global huge transit transportation is carried out through the sea ways. Different factors such as the emission of gases related to the fuel of ships in the sea and especially in ports, the leakage of oil materials due to marine accidents and the negligence of ship crews, ...
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Nowadays, more than 90% of the global huge transit transportation is carried out through the sea ways. Different factors such as the emission of gases related to the fuel of ships in the sea and especially in ports, the leakage of oil materials due to marine accidents and the negligence of ship crews, the use of port equipment, impure diesel fuel in power station generators, etc., caused an increase in greenhouse gases emergence, environmental pollution and endangering human lives. Therefore, the creation and stablishing of green ports by applying the global and international standards and complying with maritime conventions and regulations would smooth out the process of the intelligentization of ports. In consequence, it can definitely increase the speed of goods transfer, the tracking of ships and goods, provide the transparency of statistics, reducing the costs and increasing the quality and capacity of the sea ports. This research for the above mentioned reasons, has applied the integrated theory that is empowered and developed by Dempster-Shafer and the interpretive structural equations of ISM (the green and smart components of ports). According to the carried out analysis, firstly, 9 key indicators were identified in the greening and smartness of ports, then the identified indicators were classified based on the Pestel analytical model. Finally, based on Dempster-Shafer method, it was indicated that the greenness indicator of the sea port margins with a weight of 0.141 is ranked in the first place and The amount of greenhouse gas production with a weight of 0.131 was ranked as the second one and in compliance with smart technology it was ranked in the third place with a weight of 0.128. This research is also applied the approach of the ISM method for identifying the applied indicators.
علوم زیستی دریا
Shahla Hamid; Faedeh Amini; Solmaz Shirali; Kamal Ghanemi; Ahmad Shadi
Abstract
In this study, the amount of heavy metals (nickel, cadmium, lead, copper, mercury) in brown algae Sargassum sp., Padina sp. and Cystoseira sp., sediments and the amount of mercury in water were also measured. ampling was done during winter 2016 and summer 2017 at four stations from the shores of Bushehr.Analysis ...
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In this study, the amount of heavy metals (nickel, cadmium, lead, copper, mercury) in brown algae Sargassum sp., Padina sp. and Cystoseira sp., sediments and the amount of mercury in water were also measured. ampling was done during winter 2016 and summer 2017 at four stations from the shores of Bushehr.Analysis of heavy metals in sediments and algae after chemical digestion and preparation was investigated by Savanta model atomic absorption spectrophotometer. The order obtained from the concentration of heavy metals in Padina sp. cadmium > lead > nickel > copper > mercury, for Sargassum sp. as lead > copper > nickel > cadmium > mercury and for Cystoseira sp. It is in the form of copper > lead > nickel > cadmium > mercury, among which Padina sp algae had the highest accumulation of heavy metals. The order of concentration of metals in sediments was nickel > lead > copper > cadmium > mercury. All metals, except for lead metal, have a higher average in the summer season, and the average mercury metal in water was measured at 0.23 micrograms per gram of dry weight. Correlation results showed that the concentration of heavy metals (nickel, cadmium, lead, copper, and mercury) in macroalgae Padina sp, Sargassum sp, sp. Cystoseira and their adjacent sediments in the shores of Bushehr, two algae Sargassum sp. and sp. Cystoseira have a greater ability to accumulate heavy metals.Cystoseira have a greater ability to accumulate heavy metals. According to the obtained results, the concentration of heavy metal mercury in the waters of the shores of Bushehr city with its amount in the studied algae, it seems that Sargassum sp. It is a suitable material for biological monitoring of this metal in the study area.
علوم انسانی دریا
Hamidreza Abdollahian; Javaher Latifi
Abstract
One of the most important issues in international marketing is the selection of export target markets, which is the first step in the process of internationalization of companies. In this study, the factors influencing the selection of export target markets of Iranian electricity industry in Persian ...
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One of the most important issues in international marketing is the selection of export target markets, which is the first step in the process of internationalization of companies. In this study, the factors influencing the selection of export target markets of Iranian electricity industry in Persian Gulf countries were investigated. The influencing factors were studied and categorized into six dimensions, including political, market potential, economic, cultural, infrastructural, and legal factors. The views of experts, electricity industry professionals, and senior executives and representatives of Iran's foreign electricity exporters in the Gulf countries were examined. The statistical population of this research consists of 86 executives of the exporters of products of the electrical industry in Iran. In this research, the standard questionnaire for assessing the model of international markets by Wood and Robertson (2000) with 59 items was used. The questionnaire has content validity and reliability with a Cronbach's alpha of 0.819. The Friedman test was used to prioritize the effective factors and indicators (questions). To examine the role of demographic variables, independent t-test and analysis of variance (ANOVA) were performed using SPSS software. The average index was used to analyze the data. The results obtained show that among the dimensions studied, the variable of market potential is the most important dimension in the selection of target markets. After that, in order of importance, legal and legislative, economic, political and infrastructural aspects are the most effective aspects, and finally, culture was found to be an unimportant dimension in selecting export target markets of Iranian electricity industry in Persian Gulf countries.
علوم زیستی دریا
Narges Saremi; Saeed Keyvanshokooh; Seyed Mohammad Mousavi; Hamid Mohammadiazarm
Abstract
Abstract
This study was conducted to investigate the effects of nano-selenium (Se) and vitamin C on the growth and nutritional indicators and body composition of common carp (Cyprinus carpio) juveniles. Experimental diets were prepared with three levels of nanoselenium (0, 0.5, and 1 mg/kg) and three ...
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Abstract
This study was conducted to investigate the effects of nano-selenium (Se) and vitamin C on the growth and nutritional indicators and body composition of common carp (Cyprinus carpio) juveniles. Experimental diets were prepared with three levels of nanoselenium (0, 0.5, and 1 mg/kg) and three levels of vitamin C (0, 500 and 1000 mg/kg). The fish were randomly divided into nine experimental groups in triplicate and fed with experimental diets for eight weeks. The results showed that fish fed with C500Se1 and C500Se0.5 diets had a significantly higher specific growth rate than other treatments (P<0.05). The lowest feed conversion ratio was observed in the C1000Se1 treatment and the highest in the control group (P<0.05). Also, based on the results, no significant change was observed in the carcass biochemical composition of common carp juveniles (P>0.05). In general, the results show that the composition of nanoselenium and vitamin C had positive effects on the growth and nutritional indicators of common carp, and it can be stated that the diet enriched with 500 mg of vitamin C and 1 mg of nanoselenium is recommended to increase the growth of common carp.
Introduction
Selenium (Se) is an essential micronutrient that participates in the structure of selenoproteins with vital biological functions in humans and animals. Selenium is involved in antioxidant defense, growth, fertility, immunity, digestion, and absorption of food in farmed animals, and has been used in nutritional studies on various fish species. Combined supplementation of nanoselenium and vitamin C improved growth performance and health status of Nile tilapia (Oreochromis niloticus) (Dawood et al., 2020). However, the positive effects of combining nanoselenium with vitamin C in common carp have not been investigated. As studies on other species suggest that the positive effects of nanoselenium can be enhanced in combination with other micronutrients (Khalil et al., 2022), the present study aimed to investigate the effects of nanoselenium and vitamin C on growth performance and body biochemistry of common carp (Cyprinus carpio) juveniles.
Materials and methods
Experimental diets were prepared with three levels of nanoselenium (0, 0.5 and 1 mg/kg) and three levels of vitamin C (0, 500 and 1000 mg/kg). The fish were randomly divided into 9 experimental groups in triplicates and were fed with experimental diets for 8 weeks. The fish were fed twice a day (9:00 am and 17:00 pm). Each experimental treatment was aerated with constant aeration and about 20% of water was daily exchanged. During the experiment, water quality parameters were daily monitored. Temperature ranges from 27.5 to 28.3oC, pH was between 7.5 and 7.8, dissolved oxygen was 7.2 to 7.5 mg/ml and photoperiods were about 10 hours of light and 14 hours of dark and was adjusted according to the daily natural light. At the end of the experimental period, all fish in each treatment were biometrically measured and the growth parameters were calculated.
Results
The results showed that fish fed with C500Se1 and C500Se0.5 diets had a significantly higher specific growth rate than other treatments (P<0.05). The lowest feed conversion ratio was observed in the C1000Se1 treatment and the highest in the control group (P<0.05). Also, based on the results, no significant change was observed in the carcass biochemical composition of common carp juvenile (P>0.05).
Conclusion
In the present study, the addition of nanoselenium and vitamin C, alone or in combination, to the diet of common carp increased the final weight and SGR and improved the FCR. These findings are in agreement with studies that investigated the effects of Nanoselenium or vitamin C supplements in their separate application on common carp (Ashouri et al., 2015; Ghafarifarsani et al., 2022) and other fish species (Çiçek and Özoğul, 2021, Dawood et al. 2021). In general, the results show that the composition of nanoselenium and vitamin C had positive effects on the growth and nutritional indicators of common carp and it can be stated that the diet enriched with 500 mg of vitamin C and 1 mg of nanoselenium is recommended to increase the growth of common carp.
علوم زیستی دریا
Ali Mohammadi; Leila Abdoli; Arash Akbarzadeh
Abstract
Abstract:Due to the implementation of breeding programs, imported rainbow trout have better growth and quality than the rainbow trout propagated in Iran. This compared the meat quality and stress resistance of Spanish imported and Iranian rainbow trout reared in both spring and river water sources. A ...
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Abstract:Due to the implementation of breeding programs, imported rainbow trout have better growth and quality than the rainbow trout propagated in Iran. This compared the meat quality and stress resistance of Spanish imported and Iranian rainbow trout reared in both spring and river water sources. A total of 432 individuals from each breed were subjected to four treatment conditions with three replicates in 12 pools over a 90-day period. At the conclusion of the rearing period, meat quality was assessed through proximate analysis. Additionally, 20 randomly selected fish from each treatment were subjected to acute temperature stress, as well as exposure to acidic and alkaline pH conditions. Our findings reveal no significant differences in carcass protein and fat percentages between Spanish and Iranian trout across both river and spring water sources. The highest protein content was observed in Iranian and Spanish trout reared in river water. Moreover, survival rates of Spanish trout were significantly higher than those of Iranian trout when subjected to temperature stress, acidic pH, and alkaline pH in both spring and river water sources (P<0.05). Overall, our results demonstrate that Spanish rainbow trout exhibit greater resilience to environmental stressors compared to Iranian trout, likely attributed to the implementation of targeted breeding programs in this breed. INTRODUCTION Despite the widespread interest among rainbow trout farms in using imported fish for cultivation, there is a lack of comprehensive and definitive information regarding the superior growth, survival, and resistance of these strains compared to domestically produced rainbow trout. Limited research conducted in this field in the country has shown that larvae's growth indices and survival rates of Danish imports were superior to domestically produced larvae (Mahdavi et al., 2012). Additionally, Fattahi Tari and colleagues (2013) revealed that French rainbow trout had a higher protein content than Iranian samples of the same weight. Currently, Spanish eyed eggs are abundantly imported into the country and cultured in many farms (Mohammadi et al., 2023). It had previously been established that imported Spanish rainbow trout had better growth performance and survival compared to Iranian rainbow trout (Mohammadi et al., 2023). The current study involved conducting approximate analysis tests and environmental stress challenges to compare the carcass quality and resistance to acute temperature and acidic/alkaline pH stressors in Spanish and Iranian rainbow trout raised in spring water and rivers. MATERIALS AND METHODSDuring this study, a total of 864 specimens of rainbow trout fry—both domestically bred and imported from Spain (432 specimens of each)—were selected as experimental populations. These specimens, with initial weights of 19 grams for Spanish rainbow trout and 25 grams for Iranian rainbow trout, were stocked in 12 rearing tanks. The experimental treatments comprised four groups of Iranian and Spanish rainbow trout, each reared in two different water sources (spring and river) over a three-month period (90 days) in three replicates.The approximate composition of the whole body, including moisture, protein, fat, and ash, was evaluated using standard methods recommended by the Association of Official Analytical Chemists (AOAC, 2005). At the end of the feeding period, 20 fish from each treatment were randomly selected and subjected to three stress challenges—temperature stress, acidic pH, and alkaline pH—in two replicates for each stressor. The survival rate of the fish after exposure to stress was assessed and compared. RESULTS Over the 90-day period, the protein content in the flesh of Spanish and Iranian rainbow trout did not show a significant difference in either the river or spring water sources. However, within Iranian rainbow trout, significantly, higher protein content observed in river compared to spring water (P<0.05). The percentage of carbohydrates in the flesh of Spanish rainbow trout from the river water treatment and Iranian rainbow trout from river water did not show a significant difference (P>0.05).Spanish rainbow trout showed a 75% survival rate in both spring and river water sources. However, 100% of Iranian rainbow trout in both spring and river water sources were observed to be lethargic, dark in color, and at the water surface after 6 hours of temperature stress and 7 hours of acidic and alkaline pH stress. The survival rate of Spanish rainbow trout in both spring and river water sources against temperature stress, acidic pH, and alkaline pH stressors was significantly higher than that of Iranian rainbow trout in both spring and river water sources (P<0.05). DISCUSSION AND CONCLUSION The largest exporters of eyed eggs of rainbow trout to Iran include countries such as Spain, Denmark, France, Norway, and the United States. Nevertheless, comprehensive and definitive information comparing the performance of imported cultured fish to those bred in Iran is lacking. Previous studies have shown that imported Spanish rainbow trout exhibit better growth performance and survival compared to Iranian rainbow trout (Mohammadi et al., 2023). In the current study, the meat quality and resistance to acute temperature and pH stressors in Spanish and Iranian rainbow trout raised in two different water sources, spring and river, were examined and compared.The results did not reveal significant differences in the flesh analysis between Spanish and Iranian rainbow trout. However, the carcass protein content in Iranian rainbow trout was significantly higher in river water compared to spring water, which may be due to temperature and water quality differences in these two water sources.Environmental stresses, including temperature and pH stresses, particularly in intensive fish farms, can lead to reduced growth performance, health issues, and fish mortality. According to a study by Wagner et al. (1997), high temperature stress combined with high pH significantly contributed to fish mortality in rainbow trout. The current research indicated that the survival rate of Spanish rainbow trout in both spring and river water sources against temperature stress, acidic pH, and alkaline pH stressors was significantly higher than that of Iranian rainbow trout. This suggests that the breeding improvement in Spanish rainbow trout likely contributed to enhanced resistance against environmental stressors. These findings align with the better growth0 performance of Spanish rainbow trout compared to Iranian rainbow trout (Mohammadi et al., 2023).In conclusion, this study demonstrated that Spanish rainbow trout exhibited greater resilience against environmental stressors compared to Iranian rainbow trout. Additionally, considering the better growth and survival of imported Spanish rainbow trout compared to Iranian ones, it can be inferred that the better performance of Spanish rainbow trout is due to the implementation of breeding improvement programs in this species.
علوم زیستی دریا
Behzad Dehwari; Arash Shakuri; Amir Vazirizadeh
Abstract
Biodiversity and population changes of waterfowl and waterside birds are considered as one of the indicators of evaluating the desirability of coastal habitats. In this research, the biodiversity of Waterfowl and waterside birds in the coastal habitats of Chabahar has been investigated and evaluated ...
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Biodiversity and population changes of waterfowl and waterside birds are considered as one of the indicators of evaluating the desirability of coastal habitats. In this research, the biodiversity of Waterfowl and waterside birds in the coastal habitats of Chabahar has been investigated and evaluated in a four-year period. In the four-year census in five coastal habitats of Chabahar, which was carried out by the total counting method, 43,946 birds belonging to 6 orders, 13 families and 46 species of Waterfowl and waterside wintering birds were observed and identified Waterfowl species with 82.62% and waterside species with 17.38% of all birds were included. The Laridae family was counted with 53.18% of the most birds. And the Charadriidae family (Plovers) with 20 species had the highest species diversity among Waterfowl and waterside wintering birds. The study of bidiversity indices showed that the highest species diversity index of Shannon Weiner belonging to Govater habitat in 2018 ( ) and the lowest related to the Pasabandar habitat in 2016 ( 1/68). The highest species richness index of Margalef related to Govater habitat in 2017 the (R=5/25) and the lowest value related to the Pasabandar habitat in 2016 (R=2.43). The highest value of Pielou's evenness index related to the Govater habitats was J=0.77 in 2016 and the lowest value was J=0.56 for the Pasabandar habitat in 2018. The highest value of Simpson's dominance index related to Govater habitat (D = 0.93) in 2017 and the lowest value related to Govater habitat (D = 0.08) in 2016. The highest value of Berger-Parker index number related to Pasabandar habitat (d=0.45) in 2017 and the lowest value related to Govater habitat (d=0.17) in 2018. The highest value of Buzas-Gibson's evenness index related to the Ramin habitat ( =0.24) in 1998 And the lowest value related to the Pasabandar habitat ( in 1997. The results of biodiversity indicators show that Govater and Tis habitats have more favorable conditions for aquatic and aquatic migratory birds than other habitats (p>0.05).
علوم غیرزیستی دریا
Shiva Mohammadi Shamsabadi; Hakimeh Amanipoor; Sedigheh Battaleb-Looie; Sayed Hussein Roshun
Abstract
In this study, to investigate the hydrological regime and determine the environmental flow requirement of Beshar River at the Pataveh hydrometric station, hydrological methods (Tennant, Tessman, flow duration curve shifting) and hydraulic methods (wetted area) were used. For this purpose, the river flow ...
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In this study, to investigate the hydrological regime and determine the environmental flow requirement of Beshar River at the Pataveh hydrometric station, hydrological methods (Tennant, Tessman, flow duration curve shifting) and hydraulic methods (wetted area) were used. For this purpose, the river flow data were used in the statistical period of 1998-2020. First, the homogeneity and normality of the data were checked with the Run and Klomogrov-Smirnov tests. Then the hydrological characteristics of the stream were calculated in the IHA software. Finally, the environmental flow (EF) for the desired station was obtained with the above-mentioned methods. The results of this research showed that the flow rate has decreased for at least one to 90 days and the continuous period for the minimum annual flow has increased, which can be a threat to the life of plants and animals of the Beshar river ecosystem if the increasing trend continues. The environmental flow for semi-saturated and dehydrated periods by using Tennant's method were determined at 3.99 and 11.97 m3/s, respectively. Also, the environmental flow by the Tessman method indicated that the environmental demand is particularly important in the low water season and the first half of the full water period, and this amount of flow should be maintained to prevent the destruction of the river ecosystem. In the FDC-Shifting method, the environmental flow requirement (EFR) in Class A (normal), 69.60%, in class B (slightly changed) 50.10%, in class C (relatively changed) 37.80%, in Class D (largely changed) was 29.70%, in class E (severely changed) 24.20% and in class F (critically changed) 20.10%. Based on this, the FDC-Shifting class C method with an EF of about 72.54 cubic meters per second was selected as an environmental component. The environmental flow series in class C showed a decrease in flow rate over time. Based on the hydraulic method of the wet environment, the amount of environmental flow required was found to be about 20.6% of MAR.
مهندسی دریا
Sina Gharavi; Seyed Mostafa Siadatmousavi; Ali Khoshk holgh
Abstract
Sedimentation and erosion are among the most significant issues that pose serious challenges in coastal areas. The consequences of these phenomena include reduced lifespan of ports, continuous dredging, and high costs. When ports experience sedimentation, engineering solutions are required. Predicting ...
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Sedimentation and erosion are among the most significant issues that pose serious challenges in coastal areas. The consequences of these phenomena include reduced lifespan of ports, continuous dredging, and high costs. When ports experience sedimentation, engineering solutions are required. Predicting the rate and pattern of sediment deposition in the access channel and the basin of ports enables better cost management. The objective of this study is to numerically model the hydrodynamic and morphological effects using the open-source numerical model TELEMAC in the Strait of Khuran and Shahid Rajaei Port, located in the Persian Gulf. For this purpose, water surface elevations at open boundaries were provided to the model, obtained from a calibrated MIKE21 model. The hydrodynamic model was executed, and the output included velocity and water surface elevation. Additionally, the sediment transport model GAIA was coupled with the hydrodynamic model and executed. The sediment model output includes bed level changes and suspended sediment concentrations. Finally, the simulated model was validated using measurement data, confirming that the dominant flow is tidal, parallel to the coast, and reaches a maximum velocity of 2 meters per second. The water surface elevation modeled by TELEMAC indicates that localized maximum water levels reach up to 4 meters. Wind speeds rarely reach 5 meters per second in the Khuran channel, and therefore, their influence on the currents is minimal. The results from the sediment model demonstrate that the intensity of sediment deposition in the port area and the access channel is higher in the central and eastern parts of the Strait of Khuran, as well as in the western area of Shahid Rajaei Port.
e n; hassan jafari
Abstract
Carriage of goods by sea starts with maritime carriage contracts that governed by freedom of contract principle but incorporation of non-liability clause in this contracts widely in favor of carrier led to governments make legislation for remedy of this non bargaining power so the legislations are in ...
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Carriage of goods by sea starts with maritime carriage contracts that governed by freedom of contract principle but incorporation of non-liability clause in this contracts widely in favor of carrier led to governments make legislation for remedy of this non bargaining power so the legislations are in order to make balance between carrier and sender, but internal legislation in this respect led to fragmentation and this phenomena led to conflict of law , for preventing of this ,international community attempted to unification law in this area is Convention on Contracts for the International Carriage of Goods Wholly or Partly by Sea adopted by United Nations that Popularly known as the Rotterdam Rules that extending the period of responsibility of the carrier beyond tackle-to tackle and port-to-port while still allowing the parties to agree on the otherwise.Several important principles are reflected in the Rotterdam Rules. Foremost among these is the desire to achieve broad uniformity in the law governing the international carriage of goods The Rotterdam Rules now offer the only realistic possibility for an internationally uniform regime in this respect.
khadijeh nemati
Abstract
Polycyclic aromatic compounds in the marine environment are often chemically stable and resistant to the toxic effects of these compounds can be carcinogenic properties and genetic changes noted. The study of Microalgae Tetraselmis sp for the removal of aromatic compounds benzo[a]pyrene and chrysene ...
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Polycyclic aromatic compounds in the marine environment are often chemically stable and resistant to the toxic effects of these compounds can be carcinogenic properties and genetic changes noted. The study of Microalgae Tetraselmis sp for the removal of aromatic compounds benzo[a]pyrene and chrysene ring of the effluent was Bandar Imam Petrochemical . Cultivation of Microalgae in order to achieve the desired number , petrochemical wastewater samples were subjected Microalgae . The reduction in the concentration of aromatic compounds by Microalgae were measured by HPLC showed that the removal of the two compounds at a concentration of benzo[a]pyrene./5 mg L, 49/6% ± 1.8 and the concentration chrysene 5/55 mg L,33/23% ± 1.2 respectively have been . The results showed that species have the ability to reduce aromatic compounds and is also suitable for petrochemical wastewater.
علوم غیرزیستی دریا
bagher behrooz; mohammadreza khalilabadi
Abstract
One of the main and effective components in the formation of hydrodynamic conditions and characteristics of coastal areas is tidal. In this research, the pattern of fluctuations in water level and tidal flow in Arvand River is studied. The results of these studies will be used for sedimentation, erosion ...
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One of the main and effective components in the formation of hydrodynamic conditions and characteristics of coastal areas is tidal. In this research, the pattern of fluctuations in water level and tidal flow in Arvand River is studied. The results of these studies will be used for sedimentation, erosion and coastal morphological changes. The purpose of this study was to evaluate and validate the Arvandrood plume numerical hydrodynamic model using field measurements at tidal stations and achieving a tidal plane pattern. This numerical model has been developed based on the Eulerian method and has been used to determine the pattern of flow of water flow from continuity and displacement equations. The hydrodynamic modulus is the basic modulus of the flow model, it is necessary to explain that this simulator module solves on a network with structure and governing equations using finite difference. In this research, a 70x70 depth-of-dimensional file system was networked, two open borders (the boundary of the sea and the upper boundary of the river) were considered for the model. The downstream boundary of the time series of water level changes was applied to the upstream boundary Water level changes have been applied to boundaries as a constant number. After calibration, the comparison of the model results with field measurements shows that the mean squared error for the water level level is 238 m and for the water velocity, it is 127.0 m / s.
Afshin Sotoudehpour; Aghil Madadi; sayyad Asghari
Abstract
Remote sensing data has played an important role in natural resource management studies in recent years. These data, especially in water resources studies and researches, have many uses. Among water-related studies, the use of water indexes in recent years has been widely considered.These indexes have ...
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Remote sensing data has played an important role in natural resource management studies in recent years. These data, especially in water resources studies and researches, have many uses. Among water-related studies, the use of water indexes in recent years has been widely considered.These indexes have grown and developed with the advancement and production of satellite images And their precision increased dramatically.In this research, Landsat 8 and Sentinel A2 satellite images were used on coast of Bushehr on the Persian Gulf. 8 water index were selected and executed on images.In spite of the fact to exist two clases water and land unsupervised classification was applied to images and Finally, The overall accuracy and kappa coefficient values range from 77.0% to 99.6% and 0.55 to 0.99 respectively. For Landsat images, the Modified Normalized Difference Water Index (MNDWI) and the Normalized Difference pond index (NDPI) were the best indexes.Water Ratio Index (WRI) and Normalized Difference Turbidity index (NDTI) were recognized as the worst index.For Sentinel 2A images, the Modified Normalized Difference Water Index (MNDWI) and the Normalized Water Difference Index (NDWI), respectively, were the best.and the Automatic Water Extraction Index (AWEI_NSH) had the worst result.In general, the performance of the water indexes, the accuracy level of the sentinel2A images was significantly higher than the Landsat 8 images This factor can be due to the higher spatial resolution of Sentinel images.For both Landsat 8 and Sentinel A2 images the Modified Normalized Difference Water Index (MNDWI) has the best results.
Ali ghavampour; Mohammad Ali Salari Aliabadi; Hossein Zolgharneen; bita archangi
Abstract
Resource genetics idendtification is one of the most efficient strategies for fisheries management regarding commercially important marine resources.One of the valuable species of shrimp in the Persian Gulf is the banana shrimp (Fenneropenaeus merguiensis), which accounts for about 60% of total annual ...
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Resource genetics idendtification is one of the most efficient strategies for fisheries management regarding commercially important marine resources.One of the valuable species of shrimp in the Persian Gulf is the banana shrimp (Fenneropenaeus merguiensis), which accounts for about 60% of total annual shrimp catch in Hormozgan province.Identifying the genetic structure of the country's marine reserves is an effective way of efficient fisheries management. In this study, the amount of genetic diversity in the populations of this species was studied using microsatellite markers by 10 primers in four populations at Jask, Kolahi, Bandar Abbas power plant and Tula catch area and their genetic characteristics were compared with a 1 gram shrimp batch as a sample from stock enhancement project which was being stocked near kolahi area. Results of Genetic Distance Matrix, Heterozygosity, Assignment Test and Hardy-Weinberg Equilibrium at the Locations Indicated Average Population Distance (over 0.05 ) and Possible Effects of nursery ground and Regional Hydrodynamic Flows.
علوم غیرزیستی دریا
mohamadreza mohamadifar; vahid chegini; MOHAMMAD ALI NAJARPOUR
Abstract
Wind waves are one of the most important environmental factors in marine engineering projects. due to the lack of measured wave data, predicted data are used to determine the climate of the waves. Today, numerical models have become the most practical tool for predicting wind waves. However, the results ...
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Wind waves are one of the most important environmental factors in marine engineering projects. due to the lack of measured wave data, predicted data are used to determine the climate of the waves. Today, numerical models have become the most practical tool for predicting wind waves. However, the results of these models are largely error-prone. Therefore, the outputs of numerical models have to be modified based on field data. A new approach used in the present study to modify the results of numerical model output variables in the computational domain is to create a local model and modify the results in boundary conditions which results in improved wave prediction in the computational domain. For this purpose, initial simulation of the waves (SWAN model) in Caspian Sea region was performed and the simulation results were compared with field data including Anzali, Noshahr and Offshore buoys. After initial simulation of the waves, the model parameter correction method is used to reduce error of the output results. By comparing the field data and the input data, we tried to approximate the results by applying the input parameter correction, which in turn improved the wave parameters and partly improved the simulation wave height. Then, a large-scale model of the entire Caspian Sea was implemented and then, a local model was defined, the boundary of which was slightly above the offshore deployment(located in the north of southern Caspian). The results show that using this method both the wave height and their periodicity are accurately predicted.
مهندسی دریا
Farnoosh Jahanbakhshi; Mohammad Reza Noorimehr; Mohammad Esmaeildoust
Abstract
Abstract- With growth of technology, the needs for data and information security over communication channels are necessary. One of the most important issues is the establishment of information security in marine communications. The RSA encryption algorithm is one of the most popular and most asymmetric ...
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Abstract- With growth of technology, the needs for data and information security over communication channels are necessary. One of the most important issues is the establishment of information security in marine communications. The RSA encryption algorithm is one of the most popular and most asymmetric algorithms used for secure data transfer. In the RSA encryption system, due to the very long key length, the encryption and decryption step speeds decrease, so it needs to improve its speed. One of the improving ways of RSA is RPrime RSA that includes the highest decryption of speed to RSA. In this paper, the encryption and decryption speed of RPrime RSA algorithm is improved using efficient residual number system. The result of implementation and comparison shows that the proposed method has an average of %22 and %36 improved at the encryption and decryption speed than the RPrime RSA algorithm.
علوم زیستی دریا
matin khaleghi; Ahmad Savari; Alireza Safahieh; Mohsen Hamidian pour; Sadroddin Ghaemmaghami
Abstract
This study was carried out in the Gowatr mangrove forests in Gulf of Oman, on September 2017 and May 2018 during high tide with the aim of quantifying production, biomass carbon stocks of Avicennia marina and introduce of PnET-CN model. The results was showed that the mean of aboveground biomass was ...
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This study was carried out in the Gowatr mangrove forests in Gulf of Oman, on September 2017 and May 2018 during high tide with the aim of quantifying production, biomass carbon stocks of Avicennia marina and introduce of PnET-CN model. The results was showed that the mean of aboveground biomass was 28.09 ± 4.52 and 28.51 ± 4.49 t/ha, moreover, the mean of aboveground carbon stock was 11.22 ± 1.83 and 11.34 ± 1.7 t/ha, and the mean of primary production was 219.251 and 238.171 gC/m2.mo in September 2017 and May 2018, respectively. The estimated of the production and biomass carbon stocks using PnET-CN model was showed that the mean of production was 289.051 and 291.487 gC/m2.mo and the mean of aboveground biomass carbon was 12.29 and 12.76 t/ha in September 2017 and May 2018, respectively. The PnET-CN model could predict the effects of simultaneous changes in several environmental variables on the interactions among several ecosystem processes and it could estimate the amount of tree carbon stock and primary production with proper validation. PnET-CN model shown ecosystem models extended our understanding of the forest carbon cycle spatially and temporally and generated additional information about carbon stocks and fluxes.
مهندسی دریا
MORTEZA BAKHTIARI; AMIR ASHTARILARKI; Samer adnan
Abstract
Estimation of sediment transportation is one of the significant factors in river engineering. This is especially important in rivers that are used and exploited in many ways. The problem of sediment transport itself has some complexities and will be much more complex in tidal rivers. In the present study ...
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Estimation of sediment transportation is one of the significant factors in river engineering. This is especially important in rivers that are used and exploited in many ways. The problem of sediment transport itself has some complexities and will be much more complex in tidal rivers. In the present study using MIKE 21 model, particle velocity fall, erosion and sedimentation critical shear stress, Transition parameter between layers, Vertical diffusion coefficient and Roughness of bed stream are investigated. The results showed that particle velocity fall and sedimentation critical shear stress has no significant effect on sediment transport and the slope of the suspended load changes at different speeds is approximately the same. The results also show that by increasing the coefficient of transfer between layers, the concentration of suspended charge increases slightly.
مهندسی دریا
Hamid reza Karimi; Etemad odin Rabei Gholami; Nima Shahni Karam Zadeh
Abstract
Development of industrial activities in the offshore areas has led to the importance of safety of helicopters. Understanding the behavior of the wind around Helideck, especially on take-off, approach and landing are essential to enhance the safe operation of helicopters. In this regard, legislators have ...
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Development of industrial activities in the offshore areas has led to the importance of safety of helicopters. Understanding the behavior of the wind around Helideck, especially on take-off, approach and landing are essential to enhance the safe operation of helicopters. In this regard, legislators have imposed restrictions on the operation of helicopters under varying conditions of disturbance through the standards and rules. In this paper based on the Reynolds-averaged Naviere-Stokes theory, the wind current on the SPD19-A offshore platform from the 19th phase of south pars gas field complex in the CFD environment is modeled, taking into account all the effective equipment. Considering variables such as wind direction, the horizontal and vertical direction of the crane boom, 42 scenarios considered to an appropriate insight of turbulence conditions been provided. The Norsok standard has been used to select the assessment criteria and the two criteria "Horizontal velocity deviation" and "Turbulence energy" has been evaluated, also the stream lines from numerical and experimental modeling have been compared. The results indicate that in the East-West wind direction, the increase in the vertical angle of the boom improves the turbulence conditions in the center of the Helideck. In the direction of the northeast-southwest, the increase in the vertical angle of the boom causes the turbulence conditions in the helideck center to become more complicated. Also, based on the turbulence kinetic energy index, the increase of the vertical angle of the boom for both wind directions makes turbulence conditions more complicated.
علوم انسانی دریا
asghar rashnoodi; Aliashraf Ahmadian
Abstract
AbstractThe present study seeks to examine the impact of innovative and focused programs on the development of sustainable exports and test it in the country's aquaculture industry. The research in the Iranian aquaculture industry has been carried out by a mixed (qualitative-quantitative) method and ...
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AbstractThe present study seeks to examine the impact of innovative and focused programs on the development of sustainable exports and test it in the country's aquaculture industry. The research in the Iranian aquaculture industry has been carried out by a mixed (qualitative-quantitative) method and 46 exporting companies and eight university professors related to the mentioned industry have been studied. Interviews and questionnaires were used to collect data and analyzed by thematic analysis method, fuzzy Delphi technique, structural-interpretive modeling and Minimal squares technique. The research findings show that the country's aquaculture industry needs empowerment to successfully implement innovation-oriented programs. Also, in order to successfully implement innovative programs, it is necessary to create the necessary infrastructure for this important and align the structure of the organization with innovative strategies. The research findings also led to the presentation of a new model of the need for comprehensive preparation of firms for the implementation of innovative programs by introducing new levels of organizational readiness.
علوم زیستی دریا
Rahim Abdi; Azam Asad Seftjani; Mohammad Ali Salari Aliabadi; Zahra Basir
Abstract
In order to study the effect of button mushroom compost, chemical fertilizer and superphosphate on head Kidney and some blood biochemical parameters in fresh water aquaculture, after transferring fish to pools with dimensions of one hectare with equal length and width with water height of two meters ...
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In order to study the effect of button mushroom compost, chemical fertilizer and superphosphate on head Kidney and some blood biochemical parameters in fresh water aquaculture, after transferring fish to pools with dimensions of one hectare with equal length and width with water height of two meters from a single source for two months, received button mushroom compost and chemical fertilizer. In each of groups, about 20 pieces of healthy fish with the same biometric characteristics were taken. After performing the usual laboratory procedures, separation of ALT and AST enzymes was assessed by parsazmon laboratory kit. The ALP enzyme was also measured by nitrofenil phosphate P, which is based on its ability to break phosphate groups in acidic pH. LDH, TG, Alb, COL, Na, K and Ca were measured by using the parsazmon laboratory kits and autoanalyzer device and TP levels were measured by Bradford method. The levels of AST, ALT, Alb and Ca in the group two showed a significant decrease compared to the treatment group three in most of the species (p0.05). LDH, COL, ALP and Na did not differ significantly between the groups.TP, K and TG in the group two showed a significant increase compared to the group three (p0.05). According to the recent findings, it can be concluded that button mushroom compost can be used as a suitable substitute for chemical fertilizers in fresh water fish breeding ponds.
مهندسی دریا
Abdolrahim Taheri; Mahdi Tasdighi
Abstract
Design with high Confidence over hard costs overwhelms the execution of the project. Also using a low reliability coefficient raises the risk of high project failure. The degree of contribution of each parameter to uncertainty can be detected by sensitivity analysis. In this paper, the effect of uncertainty ...
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Design with high Confidence over hard costs overwhelms the execution of the project. Also using a low reliability coefficient raises the risk of high project failure. The degree of contribution of each parameter to uncertainty can be detected by sensitivity analysis. In this paper, the effect of uncertainty of three parameters of modulus of elasticity, pipeline thickness and diameter of pipe, which are three influential parameters of a pipeline geometry on the vertical buckling of the offshore pipelines are considered. Both the First Order Second Moment and the Second Order Reliability Method analyzes are considered for the pipeline parameter sensitivity analysis. First Order Second Moment have 4 impact vector and Second Order Reliability Method have 1 impact vector. The results show that the diameter of the pipeline is more effective than the other two parameters. The least difference is between the modulus of elasticity and the thickness of the pipeline, in other words, these two parameters are closely related in sensitivity. Two parameters of thickness and diameter of pipeline are resistance variable and modulus of elasticity of is a load resistance variable. Reliability index values in FORM and FOSM are distinct but close to each other, which is lower in FOSM.
مهندسی دریا
Reza Shamsi; Ali Ebrahimi
Abstract
In the last decade, planing crafts are used widely in civil and military sector due to their good performance in high speeds. Due to complex behavior of planing vessels, the hydrodynamic analysis of planning vessels is important. Computational Fluid Dynamics (CFD) is an effective and efficient tool for ...
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In the last decade, planing crafts are used widely in civil and military sector due to their good performance in high speeds. Due to complex behavior of planing vessels, the hydrodynamic analysis of planning vessels is important. Computational Fluid Dynamics (CFD) is an effective and efficient tool for the numerical hydrodynamic analysis of high speed crafts. In the present study, the hydrodynamic performance of a Naples high-speed craft is investigated using CFD and Reynolds-averaged Navier–Stokes equations (RANS). This simulation is three-dimensional, considering free surface effect and turbulent flow. To calculate the resistance and trim, the vessel is considered in two degrees of freedom. In addition to, using the 6-DOF solver and using dynamic mesh, the rigid-body dynamic equations are coupled to the fluid-governing equations. Numerical simulation are performed at Re>3.5×106 for a range of Froude number from 0.52 to 1.65, and then verified by experimental data. Comparison of the numerical and experimental results shows that the average error values for resistance and trim of the vessel are less than 3% and 9%, respectively, which confirm accuracy of RANS method. Wake and wave pattern around the planing hull also analyzed.
علوم زیستی دریا
Iman Amirzadekani; Nasim Zanguee; Seyed Mohammad Mousavi; Mohammad Zakeri
Abstract
270 fish (with an average initial weight: 20.04±0.19 g) were randomly distributed in 27 polyethylene tanks and fed by the carp commercial diet. The experimental treatments of 9 groups (4 groups with 3, 6, 9, and 12% of alfalfa powder, 4 groups with 1, 2, 3, and 4% of alcoholic extract and one ...
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270 fish (with an average initial weight: 20.04±0.19 g) were randomly distributed in 27 polyethylene tanks and fed by the carp commercial diet. The experimental treatments of 9 groups (4 groups with 3, 6, 9, and 12% of alfalfa powder, 4 groups with 1, 2, 3, and 4% of alcoholic extract and one control group) with three replications were considered for 8 weeks. At the end of the experimental period, the activity of digestive enzymes was measured in terms of U/mg Protein and liver composition. Based on the results, the highest levels of activity of digestive enzymes, amylase (674.74±61.57), lipase (6/21±/096), alkaline phosphatase (452.84±28.18), trypsin (282.05±19.98) and chymotrypsin (0.10±0.001) in the extracts of 3%, 3%, 3%, 4% and 4% extracts, respectively, and the lowest amount of these enzymes were observed respectively with values of 388.17±38.27 (control), 2.51±0.55 (control), 187.7±19.36 (12% powder), 0.030±0.004 (12% powder) and 132.47±11.47 (9% powder) (P <0.05). The highest amount of hepatic glycogen (338.35±192.13 µg/g tissue) was measured in the 3% extract treatment and the lowest amount of hepatic glycogen (607.01±101.23 µg/g tissue was in the control treatment (P <0.05). The highest level of liver lipids (146.51±6.05 mg/g tissue) was observed in the treatment of 6% powder and the lowest level of liver lipids (72.99±4.46 mg/g tissue) was observed in the treatment of 12% powder (P <0.05). According to the present study, adding powder and especially alfalfa extract to the diet can increase the activity of digestive enzymes and increase liver lipid and glycogen at certain levels.
مهندسی دریا
Abdolhossein Mohammadrahimi; Mohammadreza Negahdari; Seyed Amin Hosseini; Ehsan Parsaei
Abstract
Extensive studies on cavitation have been conducted for years as an undesirable phenomenon in marine engineering. The cavitation phenomenon causes severe damage to the body of torpedoes, ship's propellers, pump impellers and turbines. It also increases the frictional drag of submarine vessels and ...
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Extensive studies on cavitation have been conducted for years as an undesirable phenomenon in marine engineering. The cavitation phenomenon causes severe damage to the body of torpedoes, ship's propellers, pump impellers and turbines. It also increases the frictional drag of submarine vessels and imposes many limitations on their design and construction. With increasing speed in submarines and increasing of the cavitation, supercavitation occurs which can be used to create a large bubble around the vessel. Because of drag in the water is mostly due to the friction of the body, by the supercavitation, the contact of water with the torpedo is reduced and as a result the friction drag is greatly reduced and the torpedo speed will increase significantly. In this regard, by artificially injecting air into the body in the state of cavitation, the process of creating supercavitation and reaching this stage can be accelerated.In this study, in order to investigate the effect of torpedo nose shape on supercavitation, different types of torpedo bodies have been modeled and studied different nose shapes. After modeling, meshing is performed with ANSYS Fluent software and the analysis of the model in cavitation numbers (0.2, 0.3 and 0.4) will be examined. Finally, the model will be analyzed in air injection mode (artificial supercavitation) with ANSYS CFX software and the results will be presented.
علوم انسانی دریا
asghar rashnoodi; Aliashraf Ahmadian
Abstract
The present study seeks to identify a framework for implementing innovative programs in the Covid 19 pandemic. The research in the value chain of Iran's seafood exporting industries has been carried out by a mixed method (qualitative-quantitative) and 32 companies exporting the mentioned industry have ...
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The present study seeks to identify a framework for implementing innovative programs in the Covid 19 pandemic. The research in the value chain of Iran's seafood exporting industries has been carried out by a mixed method (qualitative-quantitative) and 32 companies exporting the mentioned industry have been studied through multiple case studies. Interviews and questionnaires were used to collect data and were analyzed by theme analysis method, fuzzy Delphi technique, structural-interpretive modeling and partial least squares technique. First, the value chain of the design industry has been approved by experts. Research findings show that in critical situations such as the Covid 19 pandemic, parts of the value chain that are closer to customers have higher technical capabilities to design new tactics tailored to critical situations. In addition, managers' innovation and foresight are two important factors in achieving and managing innovative tactics to deal with critical situations. Finally, a new classification of different parts of the industry value chain has been designed and presented to better deal with possible future crises.
علوم زیستی دریا
Mozhdeh Nahayat; Mohammad Zakeri; Amir Parviz Salati; Ahmad Ghasemi
Abstract
This study aimed to determine the effect of feeding frequency on growth, nutrition, and survival indices in rainbow trout (Oncorhynchus mykiss). In this experiment, 216 rainbow trout with an average weight of 38 ± 0.11 g were distributed in 18 (300-liter fiberglass) tanks complete randomly. Three ...
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This study aimed to determine the effect of feeding frequency on growth, nutrition, and survival indices in rainbow trout (Oncorhynchus mykiss). In this experiment, 216 rainbow trout with an average weight of 38 ± 0.11 g were distributed in 18 (300-liter fiberglass) tanks complete randomly. Three experimental treatments include different feeding times 1, 3, and 5 times a day (treatments 1, 2, and 3, respectively), were fed with 6 replications and based on 5% of biomass weight for 90 days. At the end of the experimental period, a significant difference was observed in all growth indices. In all these indicators, treatment 2 was superior to treatment 3. A significant difference was observed between treatments 2 and 1. The results of measuring feed efficiency ratio in this study showed that feed efficiency in treatment 1 has the lowest value and has a significant difference with treatments 2 and 3 (P<0.05). The highest value of this index was observed for treatment 2, while there was no significant difference with treatment 3. The lowest survival rate was observed in treatment 1, and the highest value was observed in treatment 2. The economic efficiency ratio showed the three times a day in treatment 2 the most cost-effective feeding times. So that the maximum amount of food cost was observed in treatment 1, and the minimum amount was observed in treatment 2. The results showed the frequency of feeding 3 times a day in terms of production in rainbow trout.
مهندسی دریا
Elham Matori; Mohammad Esmaeildoust
Abstract
The PRINCE lightweight cryptographic algorithm was introduced as a template in 2012. In this paper, we intend to change the structure of the PRINCE encryption algorithm and use a Dynamic S-BOX to increase the complexity and security of the encryption process. In order to show the efficiency of the proposed ...
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The PRINCE lightweight cryptographic algorithm was introduced as a template in 2012. In this paper, we intend to change the structure of the PRINCE encryption algorithm and use a Dynamic S-BOX to increase the complexity and security of the encryption process. In order to show the efficiency of the proposed structure, differential analysis is performed on the algorithm as well as analysis on the optimal number of revolutions for the algorithm. Analyzes and implementations show that the cryptographic structure is more complex. Despite the slight increase in memory and execution time of the algorithm, compared to the PRINCE encryption algorithm with fixed S-BOX, it has more strength against differential attack and as a result, the security in the improved algorithm has increased. Stronger also increases security.
مهندسی دریا
Javad Ahsan; Mohammad Esmaeildoust; Amer Kaabi; vahid Zareii
Abstract
The residue number system has a parallel computational structure with carry-free operations and is widely used in cases such as digital signal processing, cryptography, design of FIR filters, etc. In this paper we design an efficient reverse converter for the four-moduli set {〖2^(n-2)+1,2〗^(n-3)-1,2^(n-3)+1,2^(n-5)-1}. ...
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The residue number system has a parallel computational structure with carry-free operations and is widely used in cases such as digital signal processing, cryptography, design of FIR filters, etc. In this paper we design an efficient reverse converter for the four-moduli set {〖2^(n-2)+1,2〗^(n-3)-1,2^(n-3)+1,2^(n-5)-1}. In this moduli set, due to the selection of well-formed and balanced modulus, it leads to optimal hardware implementation, with minimum area utilization and minimum time delay. The main advantage of this design is the use of a ROM free and adder base hardware structure. The proposed moduli set are relatively prime to most existed moduli sets in literature and as results it can be employed in the implementation of Montgomery multiplication. The proposed reverse converter has a two-level structure. In the first level, the Chinese remainder theorem is used, and in the second level, the Mixed-radix conversion is used to calculate the final weighted number. The results of computational theory show low time latency and minimal hardware space in this design.
مهندسی دریا
Saeid Khaksari Nezhad; Nima Shahni Karam Zadeh; Nassim Ale Ali
Abstract
The power absorption capability of a floating oscillating body depends on the proper wave-structure interaction. A wave energy converter (WEC) device would capture the wave power as the system radiates waves in the opposite direction (phase) to the incoming waves. Hence, in order to evaluate the initial ...
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The power absorption capability of a floating oscillating body depends on the proper wave-structure interaction. A wave energy converter (WEC) device would capture the wave power as the system radiates waves in the opposite direction (phase) to the incoming waves. Hence, in order to evaluate the initial performance of a point absorber wave energy converter, determination of radiation force is crucial to design and optimal control of wave energy absorption. In this paper, once the hydrodynamic parameters are obtained for a heaving vertical-cylinder buoy, the equation of motion for the system has been considered upon the Cummins integro-differential equation. Numerical analysis of this type of equation could be computationally demanding due to the presence of a convolution term. Therefore, a program was written using the high-level language in MATLAB and the expression for the radiation force in the equation of motion has been substituted with a linear state-space model. The results of the frequency domain analysis in the range of 1-2 radians per second are implemented into the model which corresponds to the predominant wave conditions of the offshore region in Persian Gulf. The proposed open source model compared to direct calculation of the convolution integral in the equation of the motion provides highly accurate prediction and maintains system stability. The model would also be computationally cost effective for higher degrees of freedom since other codes are practically not available.
علوم زیستی دریا
Zahra Yarahmadi; Bita Archangi; Ahmad Savari; Mohammad Bagher Nabavi
Abstract
The objective of this study was to morphological description and phylogenetic study of Ornithocercus magnificus in Bandar Abbas waters. The genus Ornithocercus is a heterotrophic dinoflagellate of the family Dinophysaceae. The samples were collected using a phytoplankton net (mesh size: 20 µm) ...
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The objective of this study was to morphological description and phylogenetic study of Ornithocercus magnificus in Bandar Abbas waters. The genus Ornithocercus is a heterotrophic dinoflagellate of the family Dinophysaceae. The samples were collected using a phytoplankton net (mesh size: 20 µm) equipped with a flowmeter in surface waters. The plankton samples were scanned and identified with an inverted microscope. Then, the SSU rDNA gene fragment from individual cells have been amplified using the polymerase chain reaction and sequenced for the Iranian strain of this species. Phylogenetic analyzes were performed by Maximum Likelihood (ML) and Maximum parsimony (MP) methods. In this study, two new sequences of SSU rDNA from O. magnificus were reported for the first time and deposited in the GenBank. Morphological studies showed that the isolated cells from Iranian water were O. magnificus. Generally, the results showed; the morphological results of O. magnificus were matched with the molecular results of this study. Phylogenetic analysis grouped isolated Iranian sequences with O. magnificus and formed a monophyletic clad with other members of this genus as sister groups. The genus Histioneis is the closest relative to Ornithocercus.
علوم زیستی دریا
Davood Mafi-Gholami; Abolfazl Jaafari
Abstract
This study investigates changes in the integration status of mangroves of Hara Biosphere Reserve in the face of changes of rainfall and drought occurrences over a 31-year period (1986-2017). For this purpose, the 31-year time series of satellite images and precipitation data were used and the values ...
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This study investigates changes in the integration status of mangroves of Hara Biosphere Reserve in the face of changes of rainfall and drought occurrences over a 31-year period (1986-2017). For this purpose, the 31-year time series of satellite images and precipitation data were used and the values of the number of patches (NP) and the largest patch index (LPI) as well as the SPI valueswere obtained during the period. The results of the change in the number of patches and the largest patch index with the change in the pre1998 (wet period) and post-1998 (dry period) showed that with increasing SPI values (positive values) in the pre-1998 period (wet season), the number of patches and the index of largest patch decreased and in the post-1998 (drought period) the negative SPI values increased the number of patches and the index of the largest In fact, the results showed an increase in the size of the main cores and large vegetative patches (increased structural integrity) of the Reservoir during the wet season and its reverse trend during the drought period. According to the principles of landscape ecology, an increase in the number of patches and in the index value of the largest patch (due to a decrease in the total area of the habitat) in the post-1998 period indicates the destruction of this habitat in recent years. The results of this study are of value to assess the vulnerability of these habitats to the consequences of climate change.
مهندسی دریا
Mehdi Alavinejhad; Madjid Ghodsi Hassanabad; Mohammadjavad Ketabdari; Masoud Nekooei
Abstract
The passage of personnel and the placement of facilities on the access stairs of offshore complexes have made it very important to identify damage to these components. Modal strain energy method is one of the non-destructive and practical methods in which using changes in the dynamic properties of the ...
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The passage of personnel and the placement of facilities on the access stairs of offshore complexes have made it very important to identify damage to these components. Modal strain energy method is one of the non-destructive and practical methods in which using changes in the dynamic properties of the structure to identify the location and determine the severity of damage in the structure. In recent years, modifications have been made to the initial version of this method, one of which is to take into account the natural frequencies in locating the damage. In this paper, using the improved modal strain energy method and considering natural frequencies, a new relationship is presented to more accurately identify the location of damage in the structure and three different damage indices in the offshore platform access bridge structure are studied and compared. The results show that the average error to accurately identify the location of damage in the average Stubbs index, the improved method and the novel method are 3.55, 2.82 and 2.21 percent, respectively, so the novel method is able to more accurately identify the location of damage in the structure. Also, comparing the results of different cases shows that the average damage location error decreases with increasing damage severity. The accuracy of identifying the location of the damage also increases when move away from the supports.
Hossein Bahrami; Soroush Farkhondeh; Javad Ahadiyan
Abstract
Civil construction work in coastal areas and problems caused by undesirable soils of these areas in some places has made geotechnical studies essential for the identification and improvement of these substrates. One of the important points in the improvement of soils in all construction projects is the ...
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Civil construction work in coastal areas and problems caused by undesirable soils of these areas in some places has made geotechnical studies essential for the identification and improvement of these substrates. One of the important points in the improvement of soils in all construction projects is the choice of the type and amount of material used in the mixing plan with the soil. This choice is usually based on Requirements for a development activity and practical experience. In this study, firstly, experiments were carried out on the seawater sand mix with cement, clay and nanoclay and soil characteristics such as optimum density and humidity, modulus of elasticity, cohesion and internal friction angle were investigated. Then, using plaxis software modeling, the final displacement, strain, and final ultimate stress were compared. The results of the software investigation revealed that the mixing design of the nano-cement and sandy soil is efficient. The total displacement in cement and nanoclay combination with sandy soil decreased from 1.86 to 0.858 mm. Also, the final strain rate decreased from 55.6 to 11.06% in the combination of cement and nanoclay with sandy soil. The increase in final stress was also observed from 111.47 to 130.71 kpa in the combination of nano and cement.
Mohammad Reza Fallah Nezhad; Mehdi Behdarvandi Askar
Abstract
Overtopping and diffractin of waves are among the hydrodynamic reactions to shore protection structures, which can interfere with the operation and unrest of ports. In order to reduce the effect of hydrodynamic reactions on the coast, in this research, using flow 3D software and numerical modeling, the ...
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Overtopping and diffractin of waves are among the hydrodynamic reactions to shore protection structures, which can interfere with the operation and unrest of ports. In order to reduce the effect of hydrodynamic reactions on the coast, in this research, using flow 3D software and numerical modeling, the effect of constructing a submerged breakwater in front of rubble mound breakwater and changes in geometric parameters including structural slope, constructtion distans, the depth of submerged and the type of armor has been addressed. The non-linear waveforms with the Jonswap spectrum and the number of modes examined are 72 different models. The outputs from modeling were analyzed after drawing tables and shapes. The results showed that decreasing the gradient of the structure and the depth of submergence and increasing the distance between the constructions of the submerged breakwater has the greatest effect on the decrease of the Overtopping and diffractin of the waves. Also, tetrapod type armored vehicles in the submerged breakwater have the highest reduction in Overtopping and diffractin of waves in rubble mound breakwater in comparison to cubic and antifer armor.
Rahim Abdi; Abdullah Reesi; Ahmad Savari; Mohammad Ali Salari Aliabadi; Gholam Reza Eskandari
Abstract
For this research, the required Acanthopagrus latus fish were selected by the expected catch method and finally the same size samples with an average weight of 150 g were selected. Then, five pieces of fish in 300 liter aquariums containing water with different salinities including Khor Musa with a mean ...
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For this research, the required Acanthopagrus latus fish were selected by the expected catch method and finally the same size samples with an average weight of 150 g were selected. Then, five pieces of fish in 300 liter aquariums containing water with different salinities including Khor Musa with a mean salinity of 42.7 ± 0.34 ppt and Arvand with a mean salinity of 14.4 ± 0.29 ppt were exposed to 0.1 LC5096 obtained from the lethal toxicity of silver nanoparticles and silver nitrate. For each environment and control treatment, after two weeks of adaptation, they were placed with three replications. The sampling was performed at 1, 6, 12 and 24 hours from the caudal stalk vein with 2 cc syringes and 5 millimeter samples of liver at the end of the experiment. To separate the serum, blood samples without anticoagulant were centrifuged for 15 minutes at 3000 rpm. Finally, the activity of ALP, AST and ALT enzymes was measured and evaluated by an autoanalyzer device using diagnostic kits. Also, to prepare microscopic micrographs, paraffin sections of liver tissue were stained with hematoxylin-eosin. Results showed that two different forms of silver, including silver nitrate and silver nanoparticles, had different effects on the health and liver function of the Acanthopagrus latus which was evident in the treatment of silver nitrate. This action has been seen as a change in the activity of serum enzymes especially the increase in more times, necrosis, hyperemia, hemorrhage, biliary regurgitation and vacuolar degeneration especially at low salinities.
علوم انسانی دریا
Mojtaba Abbaspour; Tahmors Hasangholipor yasory; Mohsen Nazari; Jafar Sayareh
Abstract
Change and development in the business environment have led to the creation of a new model of competition and cooperation in the market. The competition of most countries in the world market has led to a dramatic increase in competition in international trade. To consolidate the core role of companies ...
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Change and development in the business environment have led to the creation of a new model of competition and cooperation in the market. The competition of most countries in the world market has led to a dramatic increase in competition in international trade. To consolidate the core role of companies and meet market needs, maximize market share and minimize running costs, adopting a competitive strategy has become common. The purpose of this article is to review the frequency and type of published research, the contents of research of influential countries and their cooperation, as well as major and flourishing thematic categories in coopetition strategy research from 1996 to 2022. In this study, we used CiteSpace software to analyze coopetition strategy research. Based on the analysis of 2998 researches from WoSCC database, the critical features of coopetition strategy research were obtained, which provides an overview of a system of coopetition strategy research with a view to the transportation industry worldwide. The results showed that given the thematic categories related to the transportation industry, were formed during the last decade (since 2010), but in the discussion of the flourishing of subject categories, the subject categories "Transportation Science and Technology" and "Transportation" Among the first three subject categories, they were identified with the strongest prosperity, and in particular, the industry in the last three years (2019 to 2022) has become an active field of coopetition strategy research. The results of this research will help researchers to quickly understand the frontiers of competing strategy research and gain more valuable scientific information. This study also provides resources for future research and useful insights for relevant researchers.
علوم انسانی دریا
Damoon Razmjooei; Moslem Alimohammadlou; Habib-Allah Ranaei Kordshouli; Kazem Askarifar
Abstract
The maritime industry, Similar to many other industries, is adopting industry 4.0. The implementation of industry 4.0 presents significant advantages to the maritime industry including, creating new value, fostering cooperation between port actors reducing operational cost. This paper aims to analyze ...
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The maritime industry, Similar to many other industries, is adopting industry 4.0. The implementation of industry 4.0 presents significant advantages to the maritime industry including, creating new value, fostering cooperation between port actors reducing operational cost. This paper aims to analyze the most intellectual structure of industry 4.0 and maritime research. To identify the main clusters of this research, a document co-citation analysis was applied. Furthermore, the trend of total publications, the most cited authors, Geographical distribution, and cooperation of countries of this domain was analyzed with the help of CiteSpace and Histcite Software packages. The data collected for bibliometric analysis were collected from the web of science in the timespan of 2011 to 2021. The results reveal that the number of publications in Maritime 4.0 has significantly increased since 2011 and will continue to grow rapidly in the next few years. Regarding the Geographical Distribution of Publications in the research domain, such publications primarily originate from People R China, the USA, and Italy. According to document co-citation analysis, Digitalization, Artificial intelligence, and Blockchain are the most active clusters of maritime 4.0 research.
علوم زیستی دریا
Amin Mohammad Hosseini; Sedigheh Battaleb-Looie; Hakimeh Amanipoor
Abstract
The current situation of freshwater pollution is worrying, Due to the limited fresh water resources and the increase in population and the expansion of cities and the development of industry and agriculture around the rivers, it is necessary to use the available resources correctly. Heavy metals are ...
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The current situation of freshwater pollution is worrying, Due to the limited fresh water resources and the increase in population and the expansion of cities and the development of industry and agriculture around the rivers, it is necessary to use the available resources correctly. Heavy metals are one of the non-degradable and important pollutants that exist in water, sediments and living organisms. These elements are present both in natural sources, weathering of mineral rocks and seepage from the soil, and anthropogenic sources stemming from human activities. In this study, 45 water samples of the Karun River from 5 different stations were analyzed by an Atomic Absorption Spectrometer device (AAS) for lead, mercury and cadmium content. The results show that the highest amount of pollution is related to station number 1 and the lowest amount of heavy metal pollution is related to station number 5. Pollution decreases from station number 5 to station 5. According to the results of the indices: metal index (MI), heavy metal pollution index (HPI) and degree of pollution (Cdeg), the water of the Karun river in the study area is polluted with heavy metals, some samples have moderate pollution and some They have a high degree of pollution and are undrinkable. Statistical analysis also shows that the pollution of the Karun River is not from a single source and it is possible to look for the lithology of the area (natural factor) which should be traced to the formations upstream of the dam, as well as human activities in the area (human activities). Named as the main factors of pollution.
asoul Tukieh; Heeva Elmizadeh
Abstract
This study used Satellite image processing and GIS to identify and analyze spatial changes and quantify the change in water area of Zarivar Lake in northwestern Marivan. Using satellite imagery to extract information about lake water changes and land use changes, especially in identifying changes between ...
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This study used Satellite image processing and GIS to identify and analyze spatial changes and quantify the change in water area of Zarivar Lake in northwestern Marivan. Using satellite imagery to extract information about lake water changes and land use changes, especially in identifying changes between several different time periods, is faster and more accurate than other methods. This research is based on SVM classification and Landsat satellite image processing of SS, TM and OLI sensors for 1987, 2000, 2010 and 2020 in ENVI software environment. The results showed that the SVM technique works well in identifying and extracting land use and water areas adjacent to vegetation and soil from satellite images. Due to its non-parametric nature and the assumption that it does not follow the normal distribution, this algorithm has a high resolution in differentiating the water area from the plant and soil. So that favorable conditions for classification have been monitored and the identification and detection of water area has been assigned to itself. It also showed high efficiency in areas with low vegetation. According to the research results, the use of SVM technique indicated that the applications have grown a lot in the period under review. This unmanaged development has reduced the lake's water level. As with the growth of these uses, the water level of the lake has been declining. According to the research results, it is suggested that any user development near the lake should be done with full supervision. It is also one of the basic strategies for the protection of the lake and its integrated management.
علوم زیستی دریا
Ainaz Khodanazary; Soraya Salehi; Eshagh Zamani
Abstract
The aim of this study was the effect of peeled and unpeeled shrimp on microbiological, physicochemical and sensory properties of white shrimp (Metapenaeus affinis) stored under ice. Physicochemical (TVBN, pH, TBA and FFA), bacteriological (mesophilic, psychrophilic, Enterobacteriaceae and Staphylococcus), ...
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The aim of this study was the effect of peeled and unpeeled shrimp on microbiological, physicochemical and sensory properties of white shrimp (Metapenaeus affinis) stored under ice. Physicochemical (TVBN, pH, TBA and FFA), bacteriological (mesophilic, psychrophilic, Enterobacteriaceae and Staphylococcus), color and sensory analysis were carried out at 0, 4, 8, 12 and 16 days of storage. Mesophilic, psychrophilic, Entrobacteriaceae and Staphylococcus counts of peel and unpeeled shrimp stored in ice increased from 4.27 log10 cfu/g, 5.29-5.32 log10 cfu/g, 3.25-3.99 log10 cfu/g and 3.86 log10 cfu/g to 7.50-7.62, 7.20-7.83, 6.75-7.13 and 6.42-6.69 at day 16, respectively. Mesophile, Entrobacteriaceae and Staphylococcus counts were lower in unpeeled white shrimp compared to peeled white shrimp during ice storage. However, thiobarbituric acid, free fatty acid, total volatile nitrogen and pH contents of peeled and unpeeled white shrimp did not show significant difference during storage on ice (P>0.05). Results of sensory evaluation revealed that peeled shrimp has not improved the sensory quality and color parameter of the white shrimp. Using the acceptability limit mesophilic counts (7 log cfu/g) showed that shelf life for unpeeled and peeled white shrimp stored at ice was 8 days.
علوم زیستی دریا
Maryam Khorramabadi; Ainaz Khodanazary; Ebrahim Rajabzadeh Ghatrami
Abstract
In This study, effects of chitosan and alginate enriched with gallic acid on quality of common carp (Cyprinus carpio) were investigated during refrigerated storage at 12 days.Treatments included 1) control, 2) chitosan, 3)alginate, 4) alginate-chitosan, 5)alginate-gallic acid, 6)chitosan-gallic acid, ...
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In This study, effects of chitosan and alginate enriched with gallic acid on quality of common carp (Cyprinus carpio) were investigated during refrigerated storage at 12 days.Treatments included 1) control, 2) chitosan, 3)alginate, 4) alginate-chitosan, 5)alginate-gallic acid, 6)chitosan-gallic acid, 7)alginate-chitosan-gallic acid. Comparative aerobic mesophilic bacterial counts and psychrophilic bacterial counts of control and treated samples indicated that the highest amount of aerobic mesophilic bacterial and psychrophilic bacterial counts is related to control sample (8.47 and 8.91 Log10CFU /g, respectively) and the lowest amount of them is related with samples coated with chitosan-alginate enriched with gallic acid (7.21 and 7.22 Log10CFU /g, respectively). TBA, FFA, TVB-N, and pH contents of fillets coated with alginate-chitosan enriched with gallic acid were 0.21 mg MDA/kg fish tissue, 3.91 % Oleic acid, 25.24 mg N/100g, and 7.28, respectively, which had the lowest amount in the mentioned indexes compared with other treatments (P<0.05). The results showed that bacteria analysis, TVBN content, and pH content were significantly (P<0/05) lowest contents in the samples treated with alginate compared to control group in the end of storage. Results of sensory evaluation indicated that treated fillets had higher score in compared to control samples. Alginate-chitosan coating enriched with gallic acid indicated the gighest antimicrobial and antioxidant activities compared to other coatings. Therefore, to extend the shelf life and delay the deterioration of fresh common carp fillets during refrigerated storage, alginate-chitosan coating in combination of gallic acid is more effective for 3 days.
Hossein valipour; gholamreza shams; Elham Ghanbari Adivi; nariman mehranfar
Abstract
Sustainable development, engineering measures and selection of the most appropriate protection method to organize and stabilize the coasts, depends on knowledge of the behavior of waves on the coast.Among the methods of protective structures, we can mention the coastal walls, which weaken the wave passing ...
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Sustainable development, engineering measures and selection of the most appropriate protection method to organize and stabilize the coasts, depends on knowledge of the behavior of waves on the coast.Among the methods of protective structures, we can mention the coastal walls, which weaken the wave passing along the shore by creating damping in the height waves.According to the numerical modeling approach in this study, experimental results were used to evaluate the performance of Open FOAM open source software and K-ω SST turbulence model in modeling the behavior of waves on the body of the coastal dyke.By considering the different conditions for modeling, a total of 45 experiments were selected to run the program. Finally, the results were compared with laboratory findings, which indicates the ability of the numerical model to estimate the height of the wave passing along the shore after colliding with the dyke structure.As the wave height increases, the water height before the structure increases, but its effect on the water height after the structure is greater because at a constant height of the structure, when the wave height increases, the amount of water passing increases.Therefore, when the water height after the structure increases, its difference with the previous height decreases, and therefore the wave damping decreases from a wave height of 6 to 12 cm, and the existing structure reduces the water height to a lesser extent.From the general comparison of the results, it can be said that a structure with a height of 15 cm has a higher efficiency in wave damping and reduces a greater amount of water height.
Fatameh Ghasemi Pirbalouti; Elham Ghanbari Adivi; Rohollah Fattahi; Ehsan Khavasi
Abstract
One of the coastal protection techniques is the use of breakwaters. The aim of this study is to investigate the effect of pile breakwaters on coastal waves, considering rigid cylindrical obstacles on the coastal with constant slope, the effect of their roughness on flow pattern and waves by numerical ...
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One of the coastal protection techniques is the use of breakwaters. The aim of this study is to investigate the effect of pile breakwaters on coastal waves, considering rigid cylindrical obstacles on the coastal with constant slope, the effect of their roughness on flow pattern and waves by numerical modeling in OpenFOAM software was investigated. The method used in flow modeling is RANS method and k-ω, SST model. Modeling was performed in two modes with and without barriers for three different heights of wave. Rigid cylindrical obstacles had a diameter of 0.9 cm and a height of 32 cm. They were contracted at length and width of 45×45 cm and distances of 15×15 cm, with staggered layout. In all three wave heights, the presence of obstacles greatly causes the force of waves to dissipate relative to the unobstructed state. With wave heights of 6, 9 and 12 cm, the obstacles dissipated 47.17, 68.68 and 76.42 percent more than the unobstructed state of wave force, respectively. As the wave height increases, the obstacles have absorbed more force. At wave height of 12 cm, obstacles to wave height of 9 and 6 cm, respectively, 32.35 and 72.45 (compared to no force dimension) absorbed more power. In the discussion of wave mortality in obstacle scenarios compared to unobstructed scenarios, the ability of obstacles to reduce wave height and its mortality averaged 20.88%. The results were compared with laboratory data. The absorbed force for wave height of 6, 9 and 12 cm in numerical model was 17.14, 4.23 and 7.86 percent, respectively, with laboratory model, Also, the mean square root of normal error was 0.07 and correlation coefficient was 0.99, which indicates the conformity of two numerical and laboratory models and the appropriate performance of Open FOAM software in modeling.
علوم انسانی دریا
Fatimah Hosseinpour; Amin Tabae Izady
Abstract
The present study, by reviewing some of the views regarding the reduction of the role of ports in economic growth and development over time, has tried to evaluate the effect of ports on economic growth in a group of 122 countries between 2004 and 2021. To achieve the goal in this research, the causality ...
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The present study, by reviewing some of the views regarding the reduction of the role of ports in economic growth and development over time, has tried to evaluate the effect of ports on economic growth in a group of 122 countries between 2004 and 2021. To achieve the goal in this research, the causality analysis of Dumitrescu and Hurlin was used in Unbalanced panel data and unit specific lag order, as well as a set of panel regression estimates. In this research, the liner shipping connectivity index has been used as the port performance index. The results of the causality analysis show that the bidirectional causal relationship between port performance and economic growth cannot be rejected. Also, the results of various regressions estimates of economic growth show that the performance of ports has a remarkable and significant effect on the economic growth of countries. . . . . . .
علوم غیرزیستی دریا
Somayeh Farhang Baftani; Mohammad Ali Najarpour; Masoud Sadrinasab
Abstract
Determination of causes affecting sedimentation is very important in oceanography. This study investigates mean annual sediment transport in Bolkheir port (and surrounding ports, Ameri and Rostami ports) after breakwater construction through modeling by Mike21 software. Results of this study show that ...
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Determination of causes affecting sedimentation is very important in oceanography. This study investigates mean annual sediment transport in Bolkheir port (and surrounding ports, Ameri and Rostami ports) after breakwater construction through modeling by Mike21 software. Results of this study show that construction of new breakwater and situation of Bolkheir port location (between two other ports) affect the sediment transport so that successive erosion and sedimentation frequentely occur in region between ports. Also two-dimensional sediment transport model shows gross cumulative rate of sediment transport. Rate of sediment transport in northern coast is about 5000 m3 /yr and in the southern coast is about 7000 m3 /yr . The annual rate of coastal sediment is 500 in backside of west arm of breakwater which is a meaningful amount of sediment.
مهندسی دریا
Fatemeh Asadi Talebbeigi; Saeed Jamei
Abstract
Among the wide range of new industrial materials in the design process under-load structures, Honeycomb composites are said to be one of the best substitutes for common materials used in different industries. In the first part of the present work, three different core cell configurations were chosen ...
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Among the wide range of new industrial materials in the design process under-load structures, Honeycomb composites are said to be one of the best substitutes for common materials used in different industries. In the first part of the present work, three different core cell configurations were chosen as the core cells of a sandwich beam. Then, the effect of core cells’ shape on the mechanical behavior of each structure has numerically been investigated. In the first stage, the vibration of each beam has been investigated by taking advantage of Modal analysis. In the second part, by changing the core height in different cases, the effect of core thickness on the mechanical behavior of honeycomb composites has been studied. The results show that natural frequencies, deflections, and the strength-to-weight ratio of configurations: rectangular, honeycomb, and triangular have been in descending order. Deflection and Von-Mises stress were the results obtained from simulating each model as a cantilever beam. By increasing the core thickness even more, despite the weight being increased, the beam deflection decreases, and the load-bearing and strength of the structure get increased. In the case of the similar thickness of the isotropic plate and the honeycomb composite, the bending stiffness can be enhanced to 7 times at the expense of just a 25% volumetric increase. The comparison and validation of the obtained numerical results with the empirical result show that with just a 4% difference, the results do have a close agreement.
مهندسی دریا
Ali Mohammadi; Mehriar Alimohammadi; Ahmad zadegh abadi; Abbas Khazaei
Abstract
The great circle is of special importance as the shortest distance between two points in navigation. Navigating officers must always be able to calculate the path of the great circle and the turning points on that path. One of the drawbacks of calculations in the path of the great circle is the large ...
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The great circle is of special importance as the shortest distance between two points in navigation. Navigating officers must always be able to calculate the path of the great circle and the turning points on that path. One of the drawbacks of calculations in the path of the great circle is the large volume of calculations and the uncertainty of the correct result. In this research, using the method of composite triangles, the path of the great circle is solved and two general methods for calculating the rotation points of the great circle, which include a) calculating the rotation point with equal longitude difference and b) calculating the rotation point with distance difference equal is used. Next, using the method of equal longitude difference in calculating the points of rotation, a fast and reliable relationship has been developed to calculate the points of rotation. The premise of the developed method is that the point of rotation is always equal to the difference in longitude between the origin and destination. The developed method can calculate the width of the turning point only by calculating 5 sentences from Norris book.
علوم غیرزیستی دریا
Mohammadali Roshani; Mehdi Mumipour; Hakimeh Amanipour
Abstract
Landslides are a kind of mass movement that has significant human, financial and environmental damage. Due to the destructive effects of this phenomenon on socio-economic and natural systems, it is essential to identify areas prone to mass movement and landslides throughout the country for use in land ...
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Landslides are a kind of mass movement that has significant human, financial and environmental damage. Due to the destructive effects of this phenomenon on socio-economic and natural systems, it is essential to identify areas prone to mass movement and landslides throughout the country for use in land use planning. Sadat Hosseini region is sensitive to landslides due to its lithological, climatic and land use location, young roughness with high altitude differences and steep slopes. human activities Therefore, further studies in the region seem necessary. Three models have been used for landslide sensitivity zoning in the study area including Anbalagan, Haeri-Samiei method and AHP. In this study, lithology criteria, slope, type of land use and vegetation, slope direction, river length and seismic path and altitude classes have been used to identify landslide sensitivity. Effective factor maps were prepared in GIS environment and using GIS tools and statistical analysis, landslide sensitivity zoning map was obtained. The results of the output of the models showed that in landslide sensitivity zoning using the Anbalagan model, 0.01, 33.26, 48.20, 25.35, 90.17% of the area in the sensitivity classes are very low, respectively. , Low, medium, high, very high. Adaptation of landslide sensitivity zoning maps in the study area based on the three models as well as the current status of landslides shows that most landslides are seen in young alluviums consisting of barracks and young alluvial fans. Also, the results of the Anbalagan model in the region are more in line with the existing reality.
علوم غیرزیستی دریا
Heeva Elmizadeh; Hadi Mahdipour
Abstract
The purpose of this research is the automatic recognition of morphic patterns of drainage network in the center of Lahijan River using High Resolution Panchromatic Remotely Sensed (HR-PRS) and fuzzy clustering algorithms. It also investigates the efficiency of these methods in the GeoEye-1 satellite ...
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The purpose of this research is the automatic recognition of morphic patterns of drainage network in the center of Lahijan River using High Resolution Panchromatic Remotely Sensed (HR-PRS) and fuzzy clustering algorithms. It also investigates the efficiency of these methods in the GeoEye-1 satellite imagery segmentation of the study area in order to detect geomorphic features. In this regard, fuzzy segmentation of HR-PRS panchromatic images of the study area, after radiometric and geometric preprocessing using FWS, MSA, IDF and CFM algorithms, was performed in MATLAB software. Finally, the studied fuzzy clustering algorithms with fuzzy parameters are applied to the input HR-PRS images and the results are discussed. The results show that the Classical Fusion Method and FCM (CFM) clustering algorithm has the best performance in the field of fuzzy segmentation and detection of the studied indices. This algorithm can also reduce and improve segmentation problems due to the overlap of spectral features between classes of clustering results and well identify spatial phenomena and clusters with different sizes, shapes and densities. As a result, the image borders are well defined. The reason for this is the use of fuzzy numbers as well as efficient clustering methods in this method. These results also show that remote sensing technology, by providing multi-time images, can be a very good basis for monitoring and detecting environmental changes, detecting effects and accurately extracting information from images. Also, the use of clustering algorithms and fuzzy features is a suitable and optimal method for integrating HR-PRS satellite image information from a geographical area with the aim of segmentation.
علوم انسانی دریا
Hadi Keshavarz; Mohammad Rezaei; Maryam Rezaei
Abstract
Economic shocks due to the occurrence of uncertainty as well as the effect it has on various economic programs and some macro indicators, change the motivation of economic actors and affect the production of the country's economic sectors. For this purpose, ARDL model is used for shrimp production on ...
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Economic shocks due to the occurrence of uncertainty as well as the effect it has on various economic programs and some macro indicators, change the motivation of economic actors and affect the production of the country's economic sectors. For this purpose, ARDL model is used for shrimp production on an annual basis and VECM model is used for seasonal shrimp export. The results show that exchange rate shock, price and white spot disease affect shrimp production. Exchange rates have a positive and significant effect on shrimp shock exports and both interest rates and prices have a negative and significant effect. The results of variance decomposition indicate that the most influential factor between the explanatory variables is related to the exchange rate, which after about 10 chapters explains 22% of export fluctuations, and interest rates and prices with about 9 and 5, respectively. The important point in the production and export of shrimp is that the conditions of sanctions have not affected this industry and because of its export value, it can plan for it in any economic situation and increase investment in this sector.
علوم انسانی دریا
Abbas Khazaei; Ali Mohammadi; Ahmad Zadegh Abadi
Abstract
The issue of improving the quality of learning is a constant issue in any educational environment. In the training of seafarers, this issue is of particular importance due to international maritime regulations. The quality of learning that is influenced by a wide range of factors: from the labor market ...
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The issue of improving the quality of learning is a constant issue in any educational environment. In the training of seafarers, this issue is of particular importance due to international maritime regulations. The quality of learning that is influenced by a wide range of factors: from the labor market and educational policy to the motivation, effort and individual characteristics of students. The motivations for choosing a seafaring job and learning approaches are individual characteristics.The quality of learning is influenced by students' approaches to learning, a deep approach to learning is related to a higher quality of learning and a superficial approach to a lower quality of learning, on the other hand, learning approaches can also be influenced by job choice motivations that affect the entire career process. and both phenomena are important in improving the quality of learning.The purpose of the research is to evaluate the relationship between the motivation of choosing a seafaring job on students' learning and providing solutions to improve the quality of seafarers' education. The study of sources and documents was analyzed and then quantitative analysis was used to verify qualitative information.The statistical population consists of 100 ship navigation students who were selected through available sampling. The results show that the relationship between deep approach and emotional attractiveness of students, Spearman coefficient = 0.316, talent and personal interest, Spearman coefficient = 313. 0 and the use of the professional benefits of the seafaring job shows the Spearman coefficient = 0.186.That is, if a student chooses a job with the mentioned motives, his studies and education will be of higher quality. And in deciding to become a sailor with a superficial approach and choosing a job randomly or under the influence of relatives, the studies and learning of students will be of lower quality.
علوم زیستی دریا
Hooman Makvandi; Mahsa Haghi; Mohammad Zakeri
Abstract
The goal of the current study was to determine how feeding interactions among three species of tilapia affected growth and survival indices at various weights in the laboratory. In this study, four experimental groups were examined based on various weights at 60 days in the lab: control, the interaction ...
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The goal of the current study was to determine how feeding interactions among three species of tilapia affected growth and survival indices at various weights in the laboratory. In this study, four experimental groups were examined based on various weights at 60 days in the lab: control, the interaction of Blue-Nile, the interaction of Blue-Zilli, and the interaction of Nile-Zilli. The most of growth-related indices in the Nile control were more appropriate than in other control treatments. The increase in body weight was significantly different across various treatments, according to the results of the growth and survival indices of Blue and Zilli. Zilli had 100% survival in treatments 6-7 and minimal survival in treatment 5. Blue tilapia also had the maximum survival in treatment 4 and the lowest survival in treatment 7. The results of Nile and Blue's growth and survival indices similarly revealed significant differences in most growth and survival indicators. So, in treatment 11, Nile tilapia showed the highest growth in body weight. Furthermore, the 10th treatment for the Nile considerably reported the lowest FCR. In this experiment, the Nile's highest survival rate was 100%. In Blue, the survival rate was at least 73.3%. The results of growth and survival indices were significantly affected by the exposure of Nile and Zili, like the other two interactions. In the 12th and 13th treatments, the FCR was assessed to be the lowest in Zilli and Nile. Nile in treatment 13 achieved 100% survival in the feeding interaction of Nile and Zilli. Blue tilapia appears to have less food competition than Zili and Nile. It was discovered that Nile, Zilli, and, Blue tilapia of varying weights exhibit more intense food competition behavior in laboratory conditions.
علوم زیستی دریا
Abdolsamad Dehghan; Ahmad Savari; Tooraj Valinassab; babak Doustshenas; Parvin Sadeghi
Abstract
To study the effects of monsoon on the richness and seasonal changes in the density of crabs in the intertidal area of the southern coast of Sistan and Balouchestan province, sampling was carried out in 2013 (based on the intensity of the monsoon) in three seasons: pre-monsoon, monsoon and post-monsoon ...
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To study the effects of monsoon on the richness and seasonal changes in the density of crabs in the intertidal area of the southern coast of Sistan and Balouchestan province, sampling was carried out in 2013 (based on the intensity of the monsoon) in three seasons: pre-monsoon, monsoon and post-monsoon using quadrats (Dimensions 50x50 cm and depth 10 cm), in 5 different stations. During the research, organic matter, salinity and temperature were also measured. Altogether, in this study, 17 species belonging to 10 families and 15 genera were identified. Based on the two-way ANOVA analysis results, a significant difference in brachyuran crab density and diversity was observed between the three seasons. The lowest species richness and density between the three seasons were recorded during the monsoon due to environmental stress. On the other hand, due to the presence of favorable environmental conditions for crabs, the highest density and species richness were observed in the prior and post-monsoon seasons. The statistical comparison of density in different stations showed that due to the significant relationship between density, grain size, and other environmental conditions, Jazireh Krahang and Gowater stations have the highest amount of TOM throughout the year, the presence of mud substrate and mangrove ecosystem has the highest species richness and density. In contrast, the lowest density has been recorded at Tiss and Bris. Monsoons can affect the ecology of living organisms differently. Totally, Monsoons can cause a decrease in the density and abundance of crabs during monsoon season in the intertidal zone due to their extensive effects on environmental conditions such as the content of organic matter and substrate conditions.
علوم زیستی دریا
Marzieh Afrakhte; Hossein Mohammad Asgari; Heiva Elmizade; Oliagholi khalilipour; Seyed Hossein Khazaei
Abstract
the important causes of drying up of wetlands in recent years in Iran are the continuation of drought, improper water management, land use change, and pressures caused by water shortage in the downstream areas of rivers. With the drying of the wetland, in addition to the reduction of local biological, ...
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the important causes of drying up of wetlands in recent years in Iran are the continuation of drought, improper water management, land use change, and pressures caused by water shortage in the downstream areas of rivers. With the drying of the wetland, in addition to the reduction of local biological, social and economic services of the wetland, another big environmental problem is created, and that is the becoming wetland to dust source. This change causes many environmental, social and economic damages. The purpose of this research is to investigate the changes in the area of Horalazim wetland between 2000 and 2023. To achieve this goal, the Google Earth Engine {GEE} platform was used, and by using MODIS satellite images and calculating the NDWI index, the wetland area was calculated in each image. In order to check the condition of the wetland in detail, the annual minimum, maximum and average time series of the wetland area were extracted and the anomaly of area in three states of minimum, maximum and average were calculated. The results showed that the driest year is the year 2000 with less than 0.25 of the wetland area, and the largest area is in 2019 with about 3 times the average area. The analysis of the maximum and minimum limit series along with the corresponding images determines the areas affected by drought and flood, and it is possible to implement appropriate management programs in these areas during periods of drought and flood. It should be noted that by increasing the area of the wetland, the Horalazim dust center, which is one of the most active dust centers, is controlled.
علوم غیرزیستی دریا
Zahra Godini; Hossein Mohammad Asgari; Sorosh Zarghani
Abstract
Many wetlands and wet areas, including Hour al-Azim Wetland in Mesopotamia, is getting dried and small deserts have resulted that have been the source of many dust storms in recent years. One of ways to study this event is dust simulation and forecasting. In this study, the concentrations and behavior ...
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Many wetlands and wet areas, including Hour al-Azim Wetland in Mesopotamia, is getting dried and small deserts have resulted that have been the source of many dust storms in recent years. One of ways to study this event is dust simulation and forecasting. In this study, the concentrations and behavior of dust in the wetland area of Hour al-Azim was investigated using WRF 3.7 numerical model and GOCART Schema. The corresponding model, taking into account the maximum parameters affecting the weather forecast that have a strong role in scale analysis, performs the corresponding calculations using the related equations and relations governing the atmosphere such as the equation of continuity, thermodynamic equations and observing atmospheric-chemical reactions, and produces the output as numeric matrices. The WRF model provides a reasonable estimate of the aerosols in the area under study in terms of scale and temporal changes. The concentration of PM10 simulated by the WRF model was compared with the hourly concentrations of the measuring station of the Khuzestan Department of Environment for Ahvaz. The simulated concentrations are in agreement with the hourly concentrations of the measuring station, which shows that the WRF numerical model is effective in simulating the concentration of particles. By examining the model It can be seen that the PM10 concentration in the simulation basin has been correctly obtained by the dust emission model in the study, so it can be said that the performance of the GOCART scheme in estimating the quantity of PM10 as dust concentration, especially in terms of the pattern of changes and the detection of storms, has an acceptable quality.
علوم زیستی دریا
Nasim Parniyan; Leila Abdoli; Asghar Abdoli
Abstract
A study was conducted to determine food habits brown trout (Salmo trutta), 63 specimen (42 males and 21 females) were caught using an electrofishing in January 2016. The range of total Length for males were 10.3-17.0 cm and for females 10.4-19.3 cm. Weight of males and female were the range of 8.1- 46.1 ...
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A study was conducted to determine food habits brown trout (Salmo trutta), 63 specimen (42 males and 21 females) were caught using an electrofishing in January 2016. The range of total Length for males were 10.3-17.0 cm and for females 10.4-19.3 cm. Weight of males and female were the range of 8.1- 46.1 g and 8.05-76.12 g respectively. After counting and identifying the contents of the stomach, four prey, Trichoptera, Ephemeroptera, Plecoptera and Diptera were identified, with Trichoptera with 37.60% and Diptera with 52.24% having the highest relative frequency. According to Castello, the brown trout 's feeding strategy was general and the predominant prey was Trichoptera, and female specimens use Trichoptera exclusive. The mean Shannon index of male and female were 1.26 and 1.12, respectively, and there was no significant difference between the mean Shannon index of male and female. The mean Evenness index for males and females were 0.95 and 0.81, respectively, but there was no significant difference between the mean Evenness index in male and female. The relative gut Length (RLG) and diet composition of S. trutta suggests carnivore
علوم زیستی دریا
Hakime Fartoosi; Ebrahim Rajabzadeh Ghatrami; Ainaz Khodanazary; Hossein Pasha Zanoosi
Abstract
The acidic and alkaline conditions of marine food products have an effect on the quality of the products and the duration of their storage in the organolyptic state. In this research, the effect of different levels of Iranian lime juice on the biochemical and organoleptic characteristics of Vanami shrimp ...
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The acidic and alkaline conditions of marine food products have an effect on the quality of the products and the duration of their storage in the organolyptic state. In this research, the effect of different levels of Iranian lime juice on the biochemical and organoleptic characteristics of Vanami shrimp for 60 days at freezer temperature was investigated. Biochemical parameters TVB-N, TBA, FFA and pH and organoleptic characteristics in control treatments (without adding lime juice), treatment 1 with one percent, treatment 2 with two percent and treatment 3 with three percent lime juice in 0 days. 16, 32, 48 and 60 were examined. The results showed that the parameters of pH, FFA, TBA and TVB-N showed an increasing trend in all 4 treatments with increasing storage time, but the value of these parameters decreased significantly with the increase in the level of lemon juice, and the lowest in the treatment containing 3% lemon juice. had the amount (P<0.05). At the end of the storage period (60 days of storage) with the increase in the level of lemon juice, the score given to the taste, smell and color of the shrimps was more favorable (P<0.05). On day 60, the treatment with 2% lemon juice had the highest score and the control treatment had the lowest score for taste (P<0.05). There was a difference in the amount of 1, 2 and 3% lemon juice on the 12th day of shrimp shelf life (P<0.05). 0P<) and the treatment containing 3% lemon juice showed the highest quality. Regarding the sensory parameters such as taste and smell, the 2% lemon juice treatment showed the highest quality (P<0.05). According to the results, lemon juice can be used as a suitable additive to increase the shelf life of shrimp and maintain its quality and taste.
علوم زیستی دریا
Reza Soltani; Ainaz Khodanazary; Seyyed Nasrollah Hosseini
Abstract
The objective of this study was to evaluate the freshness of gutted tigertooth croaker stored on refrigerator up to 16 days. Changes during storage were observed with sensory evaluation (Quality Index Methode QIM), pH, total volatile basic nitrogen (TVB-N), thiobarbitoric acid (TBA), and microbiological ...
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The objective of this study was to evaluate the freshness of gutted tigertooth croaker stored on refrigerator up to 16 days. Changes during storage were observed with sensory evaluation (Quality Index Methode QIM), pH, total volatile basic nitrogen (TVB-N), thiobarbitoric acid (TBA), and microbiological analyses (total mesophilic and psychrotrophic count). The maximum shelf life of gutted tigertooth croaker stored in refrigerator was determined with loss of freshness (sensorial, physico-chemical and microbiological evaluations). High correlation R2= 0.857 between Quality Index (QI) and storage time was verified. QI ranged from zero (maximum freshness) to 34 (total loss of freshness) and reached the acceptable limit for consumption. The microbiological results showed an increase of mesohilic and psychrotrophic counts along the storage time. TVB-N ranged from 12.55 to 67.70 mg N/ 100g, pH from 5.95 to 7.85, and TBA from 0.70 to 2.16 in the first and 16th day of storage, respectively. It is suggested that gutted tigertooth croaker has to be fresh and acceptable for consumption by cooling up to 12 days.