55 research outputs found

    Impact assessment of master plan of "attain to technical knowledge of specific pathogen free shrimp production and cut off to dependence on foreign products" on Bushehr city environment: A case study, Shoghab research station

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    This study is a part of the national and technology master plan entitled "Attain to technical knowledge of specific pathogen free shrimp production and cut off to dependence on foreign products". The goals of this work were to assess the environmental effects of Specific Pathogen Free shrimp production complex on surrounded region in Persian Gulf (Shoghab) research station in Bushehr city. The environmental impacts were assessed in Bandragah research station in Bushehr city by usage of comprehensive method for impacts prediction, and Pastakia Matrix for assessment during Feb 2012 till Sep 2014. Results showed 8 negative and 3 positive environmental factors that affect by operating phase including 48% very slightly negative and 44.5% slightly positive and 7.5% very slightly positive effects. Although there is no significant different between negative and positive effects but based on national strategy on getting the technology doing such a projects is highly recommended. By the usage of technical methods in effluents treatment control and reduction of bad impacts is achievable

    Environmental risk assessment of the activity of specific pathogen free shrimp production centers

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    This study is a part of the national and technology master plan entitled "Attain to technical knowledge of specific pathogen free shrimp production and cut off to dependence on foreign products". The goals of this work were to assess and analysis the risk factors of production of specific pathogen free Litopenaeus vannamei shrimp in its all stages (broodstocking, laravl production, shrimp farming, feeding and water quality), determining the pattern of outcomes monitoring, management and control of outcomes from April 2012 to September 2015 in Bandargah research station and Persian Gulf SPF Shrimp research station and their environment, belonging to Shrimp Research Center, located in Bushehr. Identification and screening of risk factors have been done based on Environment Aspect and Effect Analysis method, (EA)2, using a fine statement questionnaire and quantification of risks. The number of identified risk factors in Bandargah research station was 15 while it was 13 in Persian Gulf SPF Shrimp research station. The more number of risk factors in Bandargah station in respect to its number in Persian Gulf station is might due to lower level of biosecurity, physical structure and aging of Bandargah station and existence of two possible source of contamination, the Bushehr nuclear power plant pollutants and Bandargah fishing harbor, near to the station. On the basis of results, the maximum values of APN in Bandargah station was 42 while it was 30 in Persian Gulf station. These results revealed that the level of risk in Bandargah station is lower than that in Persian Gulf station. The most probable risks in both studied research stations are related to transmission of pathogens in shrimp feeding and water intake pollution

    Environmental impact assessment (EIA) on cultivation of the nile tilapia (Oreochromis niloticus) with brackish water in Dashtestan

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    EIA is a worthy tool for identifying and assessing potential impacts and control them.it compatibles environmental aspects with sustainable development. In order to predict the effects of tilapia culture activities on regional we gathered physical, biological, and social information to quantify the activities effects on them. We addressed 42 impacts consist of 31 positive, and 11 negative. These affect half of social, 33% of physical, and 17 of biological elements. This equivalent with -42, +304, and+36 when puts in the charts.in order to have a good and comprehensive assessment of activities Leopold matrices was employed. Based on summarized values from this we have +380and -82 results +298. This means that this activity has a great positive result especially on socio-economic environment. These kinds of studies are highly recommended for other parts of the Bushehr province e.g Dashtestan county that most of their water resources are brackish and not suitable for agriculture

    Determination of the density of water emulsions in the crude oil dehydration process

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    The salt elimination from produced crude oil is an important stage in oilfield processing and it is considered as a compulsory requirement in the oil industry. In most cases, salt is found a dissolved component in the brine phase in contact with oil. Different compositions of various salts might exist in the brine; however, sodium chloride (NaCl) has the highest fraction in the solution. The water existing in the crude oil is seen as very small drops dispersed in the bulk of oil. In the current study, a simple predictive strategy for density determination of aqueous salty solution in crude oil as a function of salinity (in vol% of sodium chloride concentration), temperature, and pressure is proposed through combination of an Arrhenius-type asymptotic exponential function and the relationship introduced by Spivey et al. (2004). The developed method predicts the amount of salt in the crude oil for temperatures up to 373 K, sodium chloride concentrations up to 250,000 ppm (25% by volume), and maximum pressure of 200 MPa, upon availability of the required input data. Estimations obtained from the proposed approach are found to be in very good agreement with the reported data in the literature so that the absolute error percentage varies in the range of 0.003–1.681%. The technique introduced in this research appears to provide reliable value for the oil engineers to attain a fast estimation of the salt content in the crude oil at various operating conditions without conducting laboratory tests. It is believed that the approach would be user-friendly without complicated computations for chemical and petroleum engineers and researchers. It can be also combined with existing thermodynamic software packages, resulting in an accurate and fast predictive model for practical applications

    Asphaltene deposition in petroleum reservoirs: dynamic test & connectionist modeling

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    Asphaltene Deposition is a complex process that can lead to a decline in oil production rates due to permeability and wettability alteration. Asphaltene instability occurs due to variations in thermodynamics properties such as pressure, temperature, and mixture composition. In this study, dynamic experiments were conducted using oil samples to measure important phase behaviour properties such as bubble point pressure (BPP) and the amount deposited as asphaltene. A thermodynamic model was also developed to determine equilibrium composition of the oil samples considering asphaltenes. We investigated the potential application of using feed-forward Artificial Neural Network (ANN) optimized by Imperialist Competitive Algorithm (ICA) and Particle Swarm Optimization (PSO) to estimate the boiling point pressure and asphaltene deposition. Comparison between the smart technique predictions and the experimental data shows an acceptable match. It is found that pressure drop and temperature are the most important factors contributing to asphaltene precipitation. Employing laboratory PVT data and connectionist modeling can result in the construction of an asphaltene phase envelope through an effective and accurate manner. The outcomes of this study, in terms of thermodynamic framework and predictive tools, appear to be useful in the design stage of more efficient EOR processes

    Optimization of Thermal Conductivity of NanoPCM-Based Graphene by Response Surface Methodology

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    Common phase change materials (PCMs) possess very low thermal conductivity whilst hybrid PCM with graphene filler could be produced to achieve increased thermal conductivity. This research focuses on the effects of graphene flakes on the thermal conductivity of a PCM (paraffin wax). Three experimental parameters at different levels of average lateral sizes of graphene flakes (4.5, 5 and 7µm), mass fractions (0.1, 0.2 and 0.25 wt.%), and rising temperatures (25-75°C) are considered. For the first time in the literature, the impact of various parameters on the thermal conductivity performance of the nanoPCM-based graphene nano-composites is investigated extensively by adopting response surface methodology supported by central composite design. Thermal conductivity prediction is proposed by a new general correlation and a promising value of the coefficient of determination (R2) higher than 0.88. Amongst the investigated various variables in terms of impact on thermal conductivity, the temperature is identified as the most influential parameter on response variables. According to the implemented optimization technique, for the composite with the average graphene flake size of 4.5 µm, the optimum value of the thermal conductivity is found 0.275 W/m K at the mass fraction of 0.186 wt.% and temperature of 69.73°C
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