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Mean trophic level of coastal fisheries landings in the Persian Gulf(Hormuzgan Province), 2002–2011

Chinese Journal of Oceanology and Limnology 2017年第3期35卷 528-536页

作者： Marzieh RAZZAGHI Sakineh MASHJOOR ehsan KAMRANI Marine Biology Department Faculty of Marine Science and TechnologyHormuzgan University.Bandar-e-abbasIran Young Researchers Club Bandar-e-abbas BranchIslamic Azad UniversityBandar-e-abbasIran Young Researchers Club Ahvaz BranchIslamic Azad UniversityAhvazIran

Fishing activities can alter the structure of marine food webs by the selective removal of some species. The changes in the marine food webs of the Hormuzgan waters of the Persian Gulf, Iran were assessed, based on estimates of the mean trophic index （MTI） and Fishing in Balance index （FIB）, and on landing profile of the exploited marine community （49 species） during the period, 2002-2011. The total landings （Yt）（R=0.88, P〈0.001） increased gradually while the Y~ of carnivores has slightly declined, and the Yt of herbivores, detritivores and omnivores has increased. Consequently, the MTI significantly decreased （R=-0.69, P〈0.05） at a rate of 0.1 l during this decade. The MTI showed a decreasing trend, which indicates exploitation of marine resources. The FiB index also showed a downward trend and negative values from 2002 to 2009, which may be associated with unbalanced structure in the fisheries, but an upward trend from 2009 to 20ll. The time variation of the landing profile showed two periods with significant differences in their species composition （R=0.88; P=0.005）, and based on analysis of similarity, species have been identified as discriminator species, namely Thunnus albacores and Benthosema pterotum. Results indicate that changes in MTI reflected changes in the Hormuzgan landing structure. The examination of the MTI, FBI, and landing profile （LP） temporal pattern suggests that the status of fishery resources in Hormuzgan inshore waters is overexploited, and provides evidence of the probability that a fishing down process is occurring in this area, and that this trend may continue in the long-tenn. Therefore, environmental fisheries management and conservation programs should be prioritized for these valuable resources.

关键词： fishing-in-balance index trophic level landings Hormuzgan Persian Gulf

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An accurate empirical correlation for predicting natural gas viscosity

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Journal of Natural Gas Chemistry 2011年第6期20卷 654-658页

作者： ehsan Sanjari Ebrahim Nemati Lay Mohammad Peymani Department of Chemical Engineering Faculty of EngineeringUniversity of Kashan

Natural gas viscosity is an important parameter in many gas and petroleum engineering *** study presents a new empirical model for quickly calculating the natural gas *** model was derived from 4089 experimental viscosity data with varieties ranging from 0.01 to 21,and 1 to 3 of pseudo reduced pressure and temperature,*** accuracy of this new empirical correlation has been compared with commonly used empirical models,including Lee et al.,Heidaryan et al.,Carr et al.,and Adel Elsharkawy *** comparison indicates that this new empirical model can predict viscosity of natural gas with average absolute relative deviation percentage AARD （%） of 2.173.

关键词： viscosity natural gas correlation empirical model

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Design of binder jet additive manufactured co-continuous ceramic-reinforced metal matrix composites

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Journal of Materials Science & Technology 2020年第14期47卷 81-90页

作者： Pablo D.Enrique ehsan Marzbanrad Yahya Mahmoodkhani Ali Keshavarzkermani Hashem Al Momani ehsan Toyserkani Norman Y.Zhou University of Waterloo 200 University Ave WWaterlooOntarioN2L 3G1Canada

Ceramic-reinforced metal matrix composites(MMCs)display beneficial properties owing to their combination of ceramic and metal ***,the properties are highly dependent on the reinforcing phase composition,volume fraction and *** fiber or network reinforcement morphologies are difficult and expensive to manufacture,and the often-used discontinuous particle or whisker reinforcement morphologies result in less effective ***,we demonstrate the formation of a co-continuous ceramic-reinforced metal matrix composite using solid-state *** jet additive manufacturing(BJAM)was used to print a nickel superalloy part followed by post-processing via reactive sintering to form a continuous carbide reinforcing phase at the particle *** kinetics of reinforcement formation are investigated in order to develop a relationship between reactive sintering time,temperature and powder composition on the reinforcing phase thickness and volume *** evaluate performance,the wear resistance of the reinforced BJAM alloy 625 MMC was compared to unreinforced BJAM alloy 625,demonstrating a 64%decrease in the specific wear rate under abrasive wear conditions.

关键词： Binder jetting Reactive sintering Metal matrix composite Co-continuous composite Wear resistance

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U-shaped energy loss curves utilization for distributed generation optimization in distribution networks

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Journal of Zhejiang University-Science C(Computers and Electronics) 2013年第11期14卷 887-898页

作者： Reza EBRAHIMI Mehdi ehsan Hassan NOURI Department of Electrical Engineering Science and Research BranchIslamic Azad University Centre of Excellence in Power System Management and Control (CEPSMC) Sharif University of Technology Department of Engineering Design and Mathematics University of the West of England (UWE Bristol)

We propose novel techniques to find the optimal location,size,and power factor of distributed generation(DG) to achieve the maximum loss reduction for distribution *** the optimal DG location and size is achieved simultaneously using the energy loss curves technique for a pre-selected power factor that gives the best DG *** on the network's total load demand,four DG sizes are *** are used to form energy loss curves for each bus and then for determining the optimal DG *** study shows that by defining the energy loss minimization as the objective function,the time-varying load demand significantly affects the sizing of DG resources in distribution networks,whereas consideration of power loss as the objective function leads to inconsistent interpretation of loss reduction and other *** devised technique was tested on two test distribution systems of varying size and complexity and validated by comparison with the exhaustive iterative method(EIM) and recently published *** showed that the proposed technique can provide an optimal solution with less computation.

关键词： Distributed generation(DG) Distribution networks Loss reduction DG optimization Energy loss curves

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New design equations for estimation of ultimate bearing capacity of shallow foundations resting on rock masses

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Geoscience Frontiers 2016年第1期7卷 91-99页

作者： Amir H.Alavi ehsan Sadrossadat Department of Civil and Environmental Engineering Michigan State University Department of Civil Engineering Mashhad BranchIslamic Azad University

Rock masses are commonly used as the underlying layer of important structures such as bridges, dams and transportation constructions. The success of a foundation design for such structures mainly depends on the accuracy of estimating the bearing capacity of rock beneath them. Several traditional numerical approaches are proposed for the estimation of the bearing capacity of foundations resting on rock masses to avoid performing elaborate and expensive experimental studies. Despite this fact, there still exists a serious need to develop more robust predictive models. This paper proposes new nonlinear prediction models for the ultimate bearing capacity of shallow foundations resting on non-fractured rock masses using a novel evolutionary computational approach, called linear genetic programming. A comprehensive set of rock socket, centrifuge rock socket, plate load and large-scaled footing load test results is used to develop the models. In order to verify the validity of the models, the sensitivity analysis is conducted and discussed. The results indicate that the proposed models accurately characterize the bearing capacity of shallow foundations. The correlation coefficients between the experimental and predicted bearing capacity values are equal to 0.95 and 0.96 for the best LGP models. Moreover, the derived models reach a notably better prediction performance than the traditional equations.

关键词： Rock mass properties Ultimate bearing capacity Shallow foundation Prediction Evolutionary computation Linear genetic programming

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Effect of Functionalized Magnetite Nanoparticles and Diaminoxanthone on the Curing, Thermal Degradation Kinetic and Corrosion Property of Diglycidyl Ether of Bisphenol A-Based Epoxy Resin

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Chinese Journal of Polymer Science 2014年第11期32卷 1489-1499页

作者： Moslem Mansour Lakouraj Ghasem Rahpaima ehsan Nazarzadeh Zare Department of Polymer Chemistry Faculty of ChemistryUniversity of Mazandaran BabolsarIran

To prepare a high-performance epoxy resin with excellent thermal, chemical and corrosion stability, diaminoxanthone（DAX） was used to cure diglycidylether of bisphenol-A（DGEBA）-based epoxy resin and blend of DGEBA with functionalized Fe3O4 nanoparticles. Kinetic parameters of curing and thermal degradation of epoxy resin systems were estimated by differential scanning calorimetry（DSC） and thermogravimetric analysis（TGA）, respectively. The 10% weight loss temperature has been increased from 340 °C to 366 °C and there was an increase in the char yield from 32.6% to 45.3% for the above systems. The corrosion performance of epoxy coated carbon steel was examined by potentiodynamic polarization, along with immersion test in 1.0 mol/L HCl solution. The results showed that epoxy resins cured with DAX had low tendency to corrosion. In addition, the cured epoxy resin containing 10% Fe3O4 had higher anticorrosion activity than bare DGEBA system. The results showed that functionalized Fe3O4 nanoparticles enhanced char formation and improved the thermal stability as well as anticorrosion activity of the resin.

关键词： Epoxy resin Diaminoxanthone Nanocomposite Thermal properties Corrosion stability.

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Seismotectonics and consequences of the 1930s large earthquakes in eastern Mazandaran,north of Iran

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Journal of Mountain Science 2022年第2期19卷 513-528页

作者： Mohsen EHTESHAMI-MOINABADI ehsan ABBASI Ali SAKET Department of Sedimentary Basins and Petroleum Shahid Beheshti UniversityTehran ***Iran Natural Disaster Research Institute Tehran ***Iran

Early in the 1930 s,two relatively large earthquakes(Kosout,magnitude 6.8,and Talarrud,magnitude 5.8)shook the eastern Mazandaran,northern *** the historical and instrumental seismic activity of the eastern region of Mazandaran,little is known about the status of seismotectonics and consequences of these *** paper presents a compilation of available data from early reports of these earthquakes with new structural,geomorphic and local data on the effects of this earthquake,especially co-seismic landslides and liquefaction,to assess the seismotectonics and probable causative faults of the *** is proposed that the close times of occurrence of two earthquakes might be due to local loading or triggering effect of the first earthquake on the second *** many other instrumental earthquakes in the Central Alborz,it is difficult to find the exact causative faults of important earthquakes,however the Qadikola,Chachkam or North Alborz Fault have the potential of producing Kosout earthquake and the Lalehband fault is more promising for Talarrud ***,the structural complexity of the area is also discussed in the form of a hybrid tectonic *** this model,the boundary zone of thick-skinned and active thin-skinned domains has more structural complexity than outer ***-Badeleh Shahvar pop-up structure is bounded by major faults with thick-skinned deformation *** role of older inherited fault structures and their interaction with low-slope Neogene thrusts driven from north to south by crustal tectonics and deformation is ***-seismic landslides and rock falls have great potential to be investigated in the Alborz Range for identification of prehistoric earthquakes.

关键词： Seismotectonics Co-seismic Landslide Alborz Active Fault Earthquake

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Acta Metallurgica Sinica(English Letters) 2018年第11期31卷 1183-1196页

作者： Farhad Bakhtiari Argesi Ali Shamsipur Seyyed ehsan Mirsalehi Department of Mining and Metallurgical Engineering Amirkabir University of Technology

In this study, the dissimilar friction stir welding （FSW） butt joints between aluminum alloy 5754-H114 and commerciallypure copper were investigated. The thickness of welded plates was 4 mm and the aluminum plate was placed on theadvancing side. In order to obtain a suitable flow and a better material mixing, a 1-mm offset was considered for thealuminum plate, toward the butt centerline. For investigating the microstructure and mechanical properties of FSWedjoints, optical microscopy and mechanical tests （i.e., uniaxial tensile test and microhardness） were used, ***, the analysis of intermetallic compounds and fracture surface was examined by scanning electron microscopyand X-ray diffraction. The effect of heat generation on the mechanical properties and microstructure of the FSWed jointswas investigated. The results showed that there is an optimum amount of heat input. The intermetallic compounds formedin FSWed joints were A14Cu9 and AI2Cu. The best results were found in joints with 1000 rpm rotational speed and100 mm/min travel speed. The tensile strength was found as 219 MPa, which reached 84% of the aluminum base ***, maximum value of the microhardness of the stir zone （SZ） was attained as about 120 HV, which was greatlydepended on the grain size, intermetallic compounds and copper pieces in SZ.

关键词： Friction stir welding 5754-H114 aluminum alloy Pure copper Heat generation Microstructure Intermetallic compounds

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Probabilistic seismic loss estimation via endurance time method

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Earthquake Engineering and Engineering Vibration 2017年第1期16卷 233-245页

作者： ehsan Tafakori Saeid Pourzeynali Homayoon E. Estekanchi Department of Civil Engineering Faculty of EngineeringUniversity of GuilanP.O.Box 41635-3756RashtIran Department of Civil Engineering Sharif University of TechnologyP.O.Box 11155-9313TehranIran

Probabilistic Seismic Loss Estimation is a methodology used as a quantitative and explicit expression of the performance of buildings using terms that address the interests of both owners and insurance companies. Applying the ATC 58 approach for seismic loss assessment of buildings requires using Incremental Dynamic Analysis （IDA）, which needs hundreds of time-consuming analyses, which in turn hinders its wide application. The Endurance Time Method （ETM） is proposed herein as part of a demand propagation prediction procedure and is shown to be an economical alternative to IDA. Various scenarios were considered to achieve this purpose and their appropriateness has been evaluated using statistical methods. The most precise and efficient scenario was validated through comparison against IDA driven response predictions of 34 code conforming benchmark structures and was proven to be sufficiently precise while offering a great deal of efficiency. The loss values were estimated by replacing IDA with the proposed ETM-based procedure in the ATC 58 procedure and it was fotmd that these values suffer from varying inaccuracies, which were attributed to the discretized nature of damage and loss prediction functions provided by ATC 58.

关键词： performance-based earthquake engineering probabilistic seismic loss endurance time method uncertaintypropagation

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Role of heat balance on the microstructure evolution of cold spray coated AZ31B with AA7075

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Journal of Magnesium and Alloys 2021年第4期9卷 1467-1478页

作者： Bahareh Marzbanrad Mohammad Hadi Razmpoosh ehsan Toyserkani Hamid Jahed Mechanical and Mechatronics Engineering Department University of WaterlooCanada

A promising solid-state coating mechanism based on the cold spray technique provides highly advantageous conditions on thermal-sensitive magnesium *** study the effect of heat balance in cold spray coating on microstructure,experiments were designed to successfully coat AA7075 on AZ31B with two different heat balance conditions to yield a coated sample with tensile residual stress and a sample with compressive residual stress in both coating and *** effects of coating temperature on the microstructure of magnesium alloy and the interfaces of coated samples were then analyzed by SEM,EBSD,TEM in high-and low-heat input coating *** interface of the AA7075 coating and magnesium alloy substrate under both conditions consists of a narrow-band layer with very fine grains,followed by columnar grains of magnesium that have grown perpendicular to the *** higher temperatures,this layer became *** intermetallic phase was detected at the interface under either *** is shown that the microstructure of the substrate was affected by coating temperature,leading to stress relief,dynamic recrystallization and even dynamic grain growth of magnesium under high *** the heat input and increasing the heat transfer decreased microstructural changes in the substrate.

关键词： Cold spraying Heat balance Microstructural analysis Coating interface Magnesium Alloy AZ31B Residual Stress

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