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.
علوم زیستی دریا
Hassan Zadabbas Shahabadi; Arash Akbarzadeh; Hamideh Ofoghi; Sabihe Soleimanian-Zad; Saeid Kadkhodaei
Abstract
In modern aquaculture, energy consumption, raw materials used, and environmental effects should be considered, therefore, during the last decade, phytase has been used by aquatic feed industries as an enzyme supplement to increase the digestibility and absorption of plant compounds and improve growth ...
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In modern aquaculture, energy consumption, raw materials used, and environmental effects should be considered, therefore, during the last decade, phytase has been used by aquatic feed industries as an enzyme supplement to increase the digestibility and absorption of plant compounds and improve growth performance along with reducing phosphorus pollution in the aquatic environment. In this study, by using the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) system, the bacterial phytase gene was inserted into the model microalgae Chlamydomonas reinhardtii in the designed position of the NR gene, and the correct editing was checked and confirmed by PCR. Confirmation of the efficiency and expression of the phytase gene placed in the NR site was investigated using SDS Page gel. Also, the translation of the phytase gene was confirmed by SDS PAGE on five colonies containing the correct editing and one control sample colony as confirmation of the expression of the transgene inserted at the protein level, which indicated the successful transcription and translation of the phytase gene inserted in the exon 2 position of the microalgae NR gene. considering the benefits of producing and using phytase enzymes in aquatic diets, reducing production costs and eutrophication of aquatic ecosystems will be achieved and it can be a new perspective to accelerate the commercial production of other recombinant proteins in organisms with nutritional value "C. reinhardtii" and provide the development of the fish feed industry and modern aquaculture.
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.
علوم زیستی دریا
Afshin Sotoudehpour; Aghil Madadi; Sayyad Asghari
Abstract
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 research, have many uses. Among water-related studies, the use of water indexes in recent years has been widely considered. ...
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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 research, 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 the coast of Bushehr on the Persian Gulf. 8 water indexes were selected and executed on images. Despite the fact to exist two classes of water and land unsupervised classification were applied to images 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, and the accuracy level of the sentinel 2A 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.
Keywords: Sentinel 2A, landsat8, NDWI Index, MNDWI Index, NDPI Index
INTRODUCTION
More than 70% of the earth's surface is covered by water, then the use of remote sensing data to extract information from oceans, seas, and closed waters is very important (Alavipanah, 2004). Remote sensing data with different spatial, spectral, and temporal resolutions have provided a valuable resource for evaluating the water level and its changes in recent decades (Jawak et al., 2015). Extracting water from satellite images is more than two decades old. The use of satellite images for a general overview of phenomena and terrestrial resources recording the characteristics of phenomena by sensors and finally analyzing them in this field can help us a lot (Zarghami, 2011). activities such as checking water quality including salinity studies, checking suspended substances and sediments, checking watercolor, and chlorophyll level, and also quantitative studies of water sources are among the actions that can be done using remote sensing (Hashemi et al., 2018). Using such a technique to better control and manage the environment in advanced countries is considered a strategic technology (Mobasheri, 2014).
MATERIALS AND METHODS
The studied area is a 130-kilometer stretch from Bushehr Beach in Bushehr province. The area of the study area is about 182,650 hectares, which is located at 50° 45ʹ to 51° 6ʹ E, 28° 42ʹ to 29° 10ʹ N. The Landsat 8 satellite image of March 15, 2018, and July 17, 2001, as well as the SentinelA2 image of March 26, 2018, were used. Both images were taken with a short time interval. Landsat 8 images had a spatial resolution of 30 meters. In the Sentinel images, bands with a resolution of 10 meters were used, and for the use of other bands, the bands were unified using the Fusion operation. In this research, the 1:50000 topographic map of the Geographical Organization of the Armed Forces was also used. Also, soil maps from the Jihad Agriculture and Geology Organization with a scale of 1: 100,000 were obtained from the Mapping Organization and used. 8 indices were used: Normalized Difference Water Index (NDWI), Modified Normalized Difference Water Index (MNDWI), Normalized Difference pond index (NDPI), Normalized Difference Turbidity index (NDTI), Water Ratio Index (WRI), Normalized Difference Water Index (NDWI_A)), AWEI, AWEI_SH. To determine the correctness of the classified map, the control points prepared from the Google Heritage images were used along with 35 points taken using GPS. The Kappa coefficient was evaluated
RESULTS
By applying blue indices on both Landsat 8 and Sentinel A2 images, the blue areas were separated from the dry environment. In Landsat 8 images, the MNDWI index with an overall accuracy of 98% and a kappa coefficient of 0.97 had the best results, and the WRI index with an overall accuracy of 78% and a kappa coefficient of 0.55 presented the worst results. In Sentinel A2 images, the MNDWI index with an overall accuracy of 99% and a kappa coefficient of 0.99 had the best result, and the AWEI_NSH index with an accuracy of 77% and a kappa coefficient of 0.55 presented the worst result. For Landsat images, among the implemented indices, the modified normalized water difference index (MNDWI) and the normalized lake, wetland index (NDPI) were the best indices. Water ratio indices (WRI) and normalized turbidity difference index (NDTI) were recognized as the worst indices. For Sentinel A2 images, the modified normalized water difference index (MNDWI) and normalized water difference index (NDWI) had the best results, and the automatic water extraction index (AWEI_NSH) had the worst results. In general, in the implementation of blue indices, the level of accuracy and precision in the Cetinel A2 images was significantly higher than that of the Landsat 8 images.
CONCLUSION
In the present study, in general, the accuracy and precision of Sentinel A2 images were better than Landsat 8 in most of the indicators, and the higher spatial resolution of Sentinel images can be a reason for presenting better results. For both images, the modified normalized water difference index (MNDWI) was recognized as the best index that could distinguish water phenomena from other phenomena well; Although in the mentioned index, different results can be presented due to the combination of different bands. In both Landsat 8 and Sentinel A2 images, the automatic water extraction index (AWEI_NSH) presented the worst result in this index due to the high reflection of phenomena such as rocks, sand, the presence of shadows, and clouds with negative effects on the mentioned index. It is confused with water phenomena. On the other hand, this index showed that they provide poor results for revealing shallow waters (such as estuaries). In general, it can be said that the overall accuracy obtained in most of the applied indices shows reliable values, which is proof of the optimal choice of thresholds in these indices. Finally, the monitoring of the beaches of Bushehr from 2001 to 2018 shows that the beaches of Bushehr have undergone many changes during this period, and these changes were in the form of a regression of the coastline. The imbalance between the processes of erosion and sedimentation on this coast has caused the channel and estuary of most estuaries to shift and change in width.
References
Alavipanah, S.K., 2004. Application of remote sensing in the earth sciences (soil). University of Tehran Press. Tehran, Iran. (In Persian)
Hashemi, S.N., Akbarinasab, M. and Safarrad, T., 2018. The Detection of the Plume of the Arvand River Using Satellite Images. Hydrogeomorphology, 4(13), pp.147-164.
Jawak, S.D., Kulkarni, K. and Luis, A.J., 2015. A review on extraction of lakes from remotely sensed optical satellite data with a special focus on cryospheric lakes. Advances in Remote Sensing, 4(3), pp.196-213. DOI: 10.4236/ars.2015.43016
Mobasheri, M., 2014. Principles of physics in remote sensing and satellate technology. Khaje nasir university of technology publishers. Tehran, Iran. (In Persian).
Zarghami, M., 2011. Effective watershed management; case study of Urmia Lake, Iran. Lake and Reservoir Management, 27(1), pp.87-94. https://doi.org/10.1080/07438141.2010.541327.
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.
علوم زیستی دریا
Maryam Yaghoubzadeh; Abdolrassoul Salmanmahiny; Ali Reza Mikaeili Tabrizi; Afshin Danehkar
Abstract
In recent years, mangrove ecosystems have been threatened by effects of global climate change, in addition to human destructions. One of the most important impacts caused by climate change on mangroves, is the global sea- level rise and consequently, inundation of parts of coastal zone. Rising sea- level ...
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In recent years, mangrove ecosystems have been threatened by effects of global climate change, in addition to human destructions. One of the most important impacts caused by climate change on mangroves, is the global sea- level rise and consequently, inundation of parts of coastal zone. Rising sea- level causes mangrove retreat in many areas. However, in some regions, human settlements and coastal structures and facilities, act as limiting factors. In this study, using the two scenarios of the lowest and highest mean sea level rise over the period of 2046-2065, according to IPCC report and the results of internal studies, inundation zones caused by sea level rise in the two protected areas of Harra in Bandar Khamir and Harra Tiab and Minab was determined. Results demonstrated that if the sea level rises, the lowest and highest levels of inundation, will be 1000 and 2000 hectares respectively in Harra protected area, and about 3500 and 7000 hectares, respectively in the protected area of Tiab and Minab. Results of land cover and land use showed that, most of the hinterland, is related to poor rangeland cover and empty lands and according to regional and global predictions in sea- level rise, there is currently no barrier for mangrove migration into hinterland, but in next few years and in the future plans, land use changes need to be addressed to make more appropriate management decisions to protect these valuable ecosystems.
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 زیستی دریا
Somayeh Zangeneh; Solmaz Kakeshian; Solmaz Shirali; Ahmad Savari; Hossein Najafzadeh Varzi; Abdolali Movahedinia; Mohammad Zakeri
Abstract
The present study has performed to investigate the effects of different levels of soy and garlic phytoestrogens on ovarian structure in Yellowfin seabream (Acanthopagrus latus). A total of 105 Yellowfin seabream were divided in seven groups including a control group that were received standard ...
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The present study has performed to investigate the effects of different levels of soy and garlic phytoestrogens on ovarian structure in Yellowfin seabream (Acanthopagrus latus). A total of 105 Yellowfin seabream were divided in seven groups including a control group that were received standard food without any extract and six treatment groups that were received different doses of soy (2/5, 5 and 7/5%) and garlic (0/5, 1 and 2%) hydroalcoholic extract. Fish were fed daily at a rate of 3% of body weight twice for 14 days. Sampling was done in days of 0, 7, 10 and 14. In every time, a section of mid portion of gonad was cut for histological examination. The results showed that different doses of soy and garlic phytoestrogens have various effects on growth and development of gonad in Yellowfin seabream as a protandrous hermaphrodite fish, so that increase in dose and time of consumption of food containing garlic hydroalchoholic extract cause increase in number of vitellogenesis follicles and finally growth and development of ovary, while consumption of food containing soy hydroalcoholic extract cause observing of testis and immature ovaries containing previtellogenesis follicle and prevents gonad development from testis to ovary in protandrous hermaphrodite fish.
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.
مهندسی دریا
Mohammad Hosseini; Mohammad Hadi Fattahi; Saeid Eslamian
Abstract
The density current, as a part of the gravity currents, is the flow of one fluid within another caused by the density difference between two fluids. The density current consists of the nose, head, and body regions within the ambient fluid. In the present study, a flume with 8m length, 35cm width, and ...
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The density current, as a part of the gravity currents, is the flow of one fluid within another caused by the density difference between two fluids. The density current consists of the nose, head, and body regions within the ambient fluid. In the present study, a flume with 8m length, 35cm width, and 40cm height was used. The experiments were performed in 28 different states by changing the bed slope, density, and discharge. The results indicated that by increasing the bed slope, the concentration of the density current decreased by 12% and 19% after continuous and local narrowing, respectively, compared to the non-narrowing state. Further, the entrainment ratio increased by narrowing the flume wall, as the Richardson number decreased by 80% and the entrainment ratio increased by 5 times after narrowing. In addition, the profile formation pattern of the current velocity and concentration enhanced by increasing the inlet density and the pattern indicated more scattering in the jet region compared to the wall region.
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.