مهندسی دریا
Mohsen Shojaie; Mostafa Jafarzadeh Khatibani; Etemad ODin Rabei Gholami
Abstract
Estimating the required propulsive power of a vessel at early stage of design is important from two aspects, which are estimating the weight of the machinery as a function of required power and estimating the amount of fuel needed to determine the initial capacity of the vessel. This approximation can ...
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Estimating the required propulsive power of a vessel at early stage of design is important from two aspects, which are estimating the weight of the machinery as a function of required power and estimating the amount of fuel needed to determine the initial capacity of the vessel. This approximation can be based on empirical formulas, data of similar ships or diagrams deduced from statistical data for various types and sizes of ships. Current empirical formulas for estimating ship power are only limited to very few general equations and are inaccurate for specific type of vessels. In this study, by using 90 container ship data and multiple linear regression method, several statistical models were prepared and statistically analyzed considering the influence of the main parameters of the vessels on the required amount of power, and finally a suitable formula extracted. Evaluation of the extracted formula indicates acceptable accuracy for the container ships which can be used to estimate the required power of container ships within the range of this formula.
علوم زیستی دریا
Amir Bosak; Vahid Yavari; Hossein Mohammad Asgari
Abstract
One of the most important concerns in fisheries management is finding suitable areas and zones to invest in aquaculture with a sustainable development approach. The use of GIS is one of the most important factors for success in aquaculture development. Site selection of sturgeon breeding and farming ...
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One of the most important concerns in fisheries management is finding suitable areas and zones to invest in aquaculture with a sustainable development approach. The use of GIS is one of the most important factors for success in aquaculture development. Site selection of sturgeon breeding and farming locations was carried out using the facilities of GIS and data analysis was performed using fuzzy model, hierarchical analysis process and the fuzzy criteria AHP. The main criteria used in this study were ecological, climatic, natural and environmental, economic and social factors, barriers and limitations and sensitive habitats. Then, using the weighting method, a competency map was prepared and with considering the merit and applying the average of the merit value of each place, the priority of each place was determined. Combining this method with fuzzy logic and application in GIS environment and also taking into consideration the weight and relative importance of each feature and option, has increased the efficiency of this method. According to the results, the highest weight was awarded to ecological factors (0.321), the next ranks were awarded to climate (0.205), economic and social (0.179), natural (0.167) factors and barriers and restrictions (0.129), respectively. The most suitable areas for the development of sturgeon breeding and culture centers are located in the northern, northeastern and eastern regions of the Khuzestan province. The most unsuitable sites are located in the southern regions of the province.
علوم انسانی دریا
Seyed Jafar Sadjadi Parsa; Morteza Aalaee Meherzi; Mostafa Alaee Meherzie
Abstract
Ports play a key intermediate role between maritime and other systemes of transport. Due to the many activities that are carried out in ports nowadays, there are various dangers at any point in port and working in the port is considered a high risk job. In this research, the factors affecting occurrence ...
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Ports play a key intermediate role between maritime and other systemes of transport. Due to the many activities that are carried out in ports nowadays, there are various dangers at any point in port and working in the port is considered a high risk job. In this research, the factors affecting occurrence of work accidents in Shahid Rajaee Port were identified and prioritized. At first, the factors were identified using numerous interviews and meetings with operational managers, experts and HSE professionals and also review previous research and literature and then using Delphi technique they were selected. Prioritize the factors was done using AHP method and distributing 105 questionnaires which out of them 86 valid ones collected. The statistical population of this study are the managers and experts of HSE and operation Shahid Rajaee Port. Since research findings can be used to reduce number of work accidents in Shahid Rajaee Port, it is considered as an applied research in terms of purpose and is descriptive, in terms of the type and nature of the research. The importance and prioritization of each of the factors affecting the occurrence of workplace accidents were identified using the (AHP) hierarchical analysis process. The results showed that high risk-taking of the employees, excessive fatigue, inadequate supervision of contractors and staff / workers, respectively, were the first to third priority in influencing factors of work accidents in Shahid Rajaee Port.
علوم زیستی دریا
Halimeh Bameri; Mehran Loghmani; Gilan Attaran Fariman
Abstract
Polychaetes are important in determining the environmental status of seabed and their role in the food chain. Sampling of sediments in three areas of Beris, Ramin and Pasabandar was performed at 10 stations in the north of the Makoran Sea by Garb van-veen during three periods of pre-monsoon, monsoon, ...
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Polychaetes are important in determining the environmental status of seabed and their role in the food chain. Sampling of sediments in three areas of Beris, Ramin and Pasabandar was performed at 10 stations in the north of the Makoran Sea by Garb van-veen during three periods of pre-monsoon, monsoon, and post-monsoon winter with recordings of chemical physical parameters from November to March 2016. In the study identified 18 families of polychaetes communities it was found that the highest density in Monson period and in Post-Monsoon with 4364.67 ± 570 ind/m2 and the lowest density in Post-Manson period in Roman region with 225.33 ± 89 ind/m2. In the pasaBandar area, the highest percentages belonged to the families Spionidae, Maldanidae and Cirratulidae, and to the families of Nephtydae, Phyllodocidae and Cirratulidae and to the Ramin family's Orbiniidae, Maldanidae and Cirratulidae. One-way ANOVA showed significant differences between stations and time periods (P <0.05). The highest densities of the polychaetes were estimated in terms of the period of Monsoon> Pre-Monsoon> Post-Monsoon period, respectively. Results of correlation between polychaete density and environmental factors of grain size sediment and TOM in pre-monsoon period showed a positive and significant correlation. There was no positive and significant correlation with environmental factors in monsoon period (P <0.05), but there was a significant positive correlation with grain size in post-monsoon period (p<0.05). The results showed that winter monsoon causes significant changes in the populations of the studied areas and the increase in density in monsoon can be due to the change of the currents direction and consequent increase of nutrient load in the area.
علوم زیستی دریا
Seyed Mahmoud Rabiei; Sakineh Yeganeh; Mina Esmaeili Kharyeki
Abstract
In the present study, the antioxidant properties of protein hydrolysate produced from Caspian mullet by-products at different hydrolysis times were investigated. For this purpose, 20 pieces of Mullet fish with average weight of 300±50 g were prepared, and their by-products including head, fins ...
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In the present study, the antioxidant properties of protein hydrolysate produced from Caspian mullet by-products at different hydrolysis times were investigated. For this purpose, 20 pieces of Mullet fish with average weight of 300±50 g were prepared, and their by-products including head, fins and viscera were used for hydrolysis by alcalase enzyme 2.4 L (concentration 1.5%, temperature 55 ° C and pH 8) at different hydrolysis times including 30, 60, 120 and 180 minutes. Results showed that protein and ash content of protein hydrolysate powder were significantly increased and fat content significantly decreased compared to the raw samples (p <0.05). The soluble protein and the degree of hydrolysis of Mullet by-products increased with increasing the hydrolysis time up to 120 min (p>0.05). Free radical scavenging (DPPH) assay showed that increased with increasing the protein concentration up to 120 min. (p<0.05). The lowest IC50 value of DPPH scavenging activity was obtained at 120 and 180 min (1.04±0.06 and 1.01±0.01 mg/ml, respectively) (p<0.05). With increasing protein concentration and time of hydrolysis, the reduction ferric ion power increased significantly at all times and protein concentrations (p <0.05). Moreover, ABTS increased with increasing hydrolysis time up to 120 min (p <0.05). In general, due to the proper performance of the Mullet by-products protein hydrolysate on DPPH and ABTS free radicals scavenging and the ferric ion reduction, it can be stated that, this product can be used as an antioxidant compound.
علوم انسانی دریا
Ahmad Jafarnejad Chaghooshi; Hani Arbabi; Mohammad Ali Hatefi; Abdolkarim Pahlevani
Abstract
aturity of project management has a great impact on the rate of project success. However, the existing project management maturity models when in use both organizationally and efficiently are costly, time consuming and difficult. The purpose of this paper is to design a project management maturity ...
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aturity of project management has a great impact on the rate of project success. However, the existing project management maturity models when in use both organizationally and efficiently are costly, time consuming and difficult. The purpose of this paper is to design a project management maturity assessment model for large petrochemical industry projects to assessment project management maturity by existing project management tools and models at every level of project life cycle. In this project by means of multi granded theory that combination of granded theory and transcendent, Project management functional areas are identified.Due to the combination of the two methods, fitslty About 20 studies out of more than 150 related studies were used for hybridization and the corresponding codes were identified then by using 16 structured surveys in the form of a grounded theory, functional areas were extracted, the areas are : Project Management and Leadership Areas, Project Strategy Management, Integrated Project Management, Project Area Management, Project Time Management, Project Cost Management, Project Financing Management, Project Quality Management, Project Human Resource Management, Project Communication Management, Management Project contract logistics, project claims management, project safety and health management, project environment management, inventory management and project technologies, project business management.
مهندسی دریا
Mohammad Ramezankhani; Ali Moazemi Goudarzi; Fattaneh Morshedsolouk; Seyed Komeil Hashemi Heidari; Ali Hassani
Abstract
In this paper, the quasi-static compressive strength of two different sandwich structure designs in which cores consist of trapezoidal corrugated panels is investigated. In one design, the core consists of a cross-corrugated multilayer structure, while in the other design the core is consists of two ...
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In this paper, the quasi-static compressive strength of two different sandwich structure designs in which cores consist of trapezoidal corrugated panels is investigated. In one design, the core consists of a cross-corrugated multilayer structure, while in the other design the core is consists of two interlocking bidirectional cross-corrugated panels. For each design, three different trapezoidal wave profiles are studied and one of them is constructed and tested. The results of specimens' crushing tests under quasi-static compressive loads are compared with the numerical modeling results. Afterward, the mechanical behavior of the other four designs is evaluated numerically. The results showed that the ultimate strength of the sandwich structures with an interlocked corrugated core is higher than the ultimate strength of the other design. It was also found that, in a given design, the ultimate strength depends on the corrugation profile geometry. These results can be used in the design of high-strength light-weight structures. Measures that can be taken to improve the ultimate strength of sandwich panels include the use of polyurethane foam, which is light in weight but has high strength, or the geometry of the structure be changed.
علوم زیستی دریا
Mona Izadian; Farhad Hosseini Tayefeh; Behzad Rayegani
Abstract
Coastal-marine wetlands consisting of mangrove forests, sandy beaches, and mudflats are among the sensitive and important habitats of the southern coasts of Iran, which play an important role in the economy and livelihood of local communities. The International Mangrove Wetland of Shur, Shirin, and Minab ...
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Coastal-marine wetlands consisting of mangrove forests, sandy beaches, and mudflats are among the sensitive and important habitats of the southern coasts of Iran, which play an important role in the economy and livelihood of local communities. The International Mangrove Wetland of Shur, Shirin, and Minab Rivers is one of the important coastal wetlands of Iran, and due to facing many threats, it needs new and effective protection planning. This research has been conducted to investigate the significant changes in the levels of mangrove forests as an indicator species of the wetland, identify and prioritize the factors that threaten the biodiversity of the wetland, and provide Participatory management solutions. The calculation of mangrove level changes was done based on the time series analysis method of OLI (Operational Land Imager) sensor data from Landsat 8. The planning and implementation of participatory protection in this research included reviewing the current situation, identifying stakeholders, and holding participatory meetings to identify and prioritize threats and formulate an action plan for cooperative wetland protection. The results showed that from 2015 to 2022, mangrove forests have been destroyed in some areas by 30.78 hectares. According to the survey of the participants and stakeholder’s beneficiaries, two threats of pollution caused by the dumping of smuggled fuel and illegal fishing activities have the highest priority among the total of 15 threats identified in the wetland. In this research, for the ten important threats prioritized by the opinion of the participants, an action plan to reduce the effects of threats, including the mechanism of the threat effect, the effect on the indicator species, the economic and social effects, and the priority plan to reduce the effects of each threat has been developed. The results of this research are used in raising awareness and preparing educational content for community-based conservation programs with the participation of stakeholders, including the implementation of participatory wetland conservation and restoration projects.