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

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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

Elastic and optical properties of zinc-blende CrSb and its effective mass

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Rare Metals 2014年第5期33卷 615-621页

作者： Sahar Rezaee Arash Boochani Masoud Majidiyan Atefeh Ghaderi Shahram Solaymani Mosayeb Naseri Department of Physics College of ScienceIslamic Azad University Physics Department Sabzevar Tarbiat Moallem University Young researchers and Elite club Islamic Azad University

The elastic, optical, and effective mass properties of CrSb in zinc-blende（ZB） phase were *** calculations were carried out using the full-potential linearized augmented plane wave plus local orbital according to the density functional theory. The results of elastic calculations by generalized gradient approximation and local density approximation approximations indicate that ZB CrSb is a ductile material and its Debye temperature is rather low. Band structure and density of state calculations introduce the ZB CrSb as a half-metal with spin polarization of100 %. In metal state, 16 th and 17 th bands cut off the Fermi level. Calculations study the effective mass, Fermi velocity,and Fermi surface at 16 th and 17 th bands. In continue,optical quantities such as dielectric function, energy loss function, and optical conductivity were investigated.

关键词： Half-metal CrSb Elastic properties Optical properties

Properties of Defect Modes in Periodic Lossy Multilayer with Negative-Index-Materials

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Communications in Theoretical Physics 2013年第7期60卷 80-86页

作者： Alireza Aghajamal Mahmood Barati Department of Physics Science and Research Branch Islamic Azad University Young researchers club Science and Research Branch Islamic Azad University

Employing the characteristic matrix method, this study investigates transmission properties of onedimensional defective lossy photonic crystals composed of negative and positive refractive index layers with one lossless defect layer at the center of the crystal. The results of the study show that as the refractive index and thickness of the defect layer increase, the frequency of the defect mode decreases. In addition, the study shows that the frequency of the defect mode is sensitive to the incidence angle, polarization, and physical properties of the defect layer, but it is insensitive to the small lattice loss factor. The peak of the defect mode is very sensitive to the loss factor, incidence angle, polarization, refractive index, and thickness of the defect layer. This study also shows that the peak and the width of the defect mode are affected by the numbers of the lattice period and the loss factor. The results can lead to designing new types of narrow filter structures and other optical devices.

关键词： one-dimensional photonic crystal defect mode loss factor negative index material

Prediction of oil flow rate through an orifice flow meter: Artificial intelligence alternatives compared

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Petroleum 2020年第4期6卷 404-414页

作者： Hamzeh Ghorbani David A.Wood Abouzar Choubineh Afshin Tatar Pejman Ghazaeipour Abarghoyi Mohammad Madani Nima Mohamadian Young researchers and Elite club Ahvaz BranchIslamic Azad UniversityAhvazIran DWA Energy Limited LincolnUnited Kingdom Petroleum Department Petroleum University of TechnologyAhwazIran Young researchers and Elite club North Tehran BranchIslamic Azad UniversityTehranIran National Iranian South Oil Company(NISOC) AhvazIran Young researchers and Elite club Omidiyeh BranchIslamic Azad UniversityOmidiyehIran

Fluid-flow measurements of petroleum can be performed using a variety of equipment such as orifice meters and wellhead *** is useful to understand the relationship between flow rate through orifice meters(Qv)and the five fluid-flow influencing input variables:pressure(P),temperature(T),viscosity(μ),square root of differential pressure(ΔP^0.5),and oil specific gravity(SG).Here we evaluate these relationships using a range of machine-learning algorithms applied to orifice meter data from a pipeline flowing from the Cheshmeh Khosh Iranian oil *** coefficients indicate that(Qv)has weak to moderate positive correlations with T,P,andμ,a strong positive correlation with theΔP^0.5,and a weak negative correlation with oil specific *** order to predict the flow rate with reliable accuracy,five machine-learning algorithms are applied to a dataset of 1037 data records(830 used for algorithm training;207 used for testing)with the full input variable values for the data set *** algorithms evaluated are:Adaptive Neuro Fuzzy Inference System(ANFIS),Least Squares Support Vector Machine(LSSVM),Radial Basis Function(RBF),Multilayer Perceptron(MLP),and Gene expression programming(GEP).The prediction performance analysis reveals that all of the applied methods provide predictions at acceptable levels of *** MLP algorithm achieves the most accurate predictions of orifice meter flow rates for the dataset *** and RBF also achieve high levels of *** and LSSVM perform less well,particularly in the lower flow rate range(i.e.,<40,000 stb/day).Some machine learning algorithms have the potential to overcome the limitations of idealized streamline analysis applying the Bernoulli equation when predicting flow rate across an orifice meter,particularly at low flow rates and in turbulent flow *** studies on additional datasets are required to confirm this.

关键词： Orifice flow meters Flow-rate-predicting virtual meters Multiple machine-learning algorithm comparisons Metrics influencing oil flow Flow-rate prediction error analysis

Control over hysteresis curves and thresholds of optical bistability in different semiconductor double quantum wells

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Chinese Physics B 2015年第8期24卷 373-380页

作者： Hamedi H R Mehmannavaz M R Afshari Hadi Institute of Theoretical Physics and Astronomy Vilnius University Young researchers and Elite club Mashhad Branch Islamic Azad University Research Institute for Applied Physics University of Tabriz

The effects of optical field on the phenomenon of optical bistability(OB) are investigated in a K-type semiconductor double quantum well(SDQW) under various parametric conditions. It is shown that the OB threshold can be manipulated by increasing the intensity of coupling field. The dependence of the shift of OB hysteresis curve on probe wavelength detuning is then explored. In order to demonstrate controllability of the OB in this SDQW, we compare the OB features of three different configurations which could arise in this SDQW scheme, i.e., K-type, Y-type, and inverted Y-type systems. The controllability of this semiconductor nanostructure medium makes the presented OB scheme more valuable for applications in all-optical switches, information storage, and logic circuits of all optical information processing.

关键词： optical bistability semiconductor double quantum wells K-type Y-type and inverted Y-type schemes OB threshold intensity

Cesium carbonate supported on hydroxyapatite coated Ni_(0.5)Zn_(0.5)Fe_2O_4 magnetic nanoparticles as an efficient and green catalyst for the synthesis of pyrano[2,3-c]pyrazoles

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Chinese Chemical Letters 2015年第5期26卷 575-579页

作者： Farid Moeinpour Amir Khojastehnezhad Department of Chemistry Bandar Abbas BranchIslamic Azad University Young researchers and Elite club Mashhad BranchIslamic Azad University

Cesium carbonate supported on hydroxyapatite coated ***2O4 magnetic nanoparticles （***2O4@Hap-Cs2CO3） was found to be magnetically separable, highly efficient, green and recyclable heterogeneous catalyst. The synthesized nanocatalyst has been characterized with several methods （FT-IR, SEM, TEM, XRD and XRF） and these analyzes confirmed which the cesium carbonate is well supported to catalyst surface. After full characterization, its catalytic activity was investigated in the synthesis of pyranopyrazole derivatives and the reactions were carried out at room temperature in 50：50 water/ethanol with excellent yields （88-95%）. More importantly, the ***204@Hap-Cs2CO3 was easily separated from the reaction mixture by external magnetic field and efficiently reused at least six runs without any loss of its catalytic activity. Thus, the developed nanomagnetic base catalyst is potentially useful for the green and economic production of organic compounds.

关键词： Cesium carbonate Catalysis Pyranopyrazoles Magnetic nanoparticles Hydroxyapatite

Improved double-gate armchair silicene nanoribbon field-effect-transistor at large transport bandgap

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Chinese Physics B 2016年第1期25卷 809-816页

作者： Mohsen Mahmoudi Zahra Ahangari Morteza Fathipour Department of Electrical and Computer Engineering University of Tehran Young researchers and Elite club Yadegar-e-Imam Khomeini (RAH) Shahre-Rey Branch Islamic Azad University

The electrical characteristics of a double-gate armchair silicene nanoribbon field-effect-transistor （DG ASiNR FET） are thoroughly investigated by using a ballistic quantum transport model based on non-equilibrium Green＇s function （NEGF） approach self-consistently coupled with a three-dimensional （3D） Poisson equation. We evaluate the influence of variation in uniaxial tensile strain, ribbon temperature and oxide thickness on the on-off current ratio, subthreshold swing, transconductance and the delay time of a 12-nm-length ultranarrow ASiNR FET. A novel two-parameter strain mag- nitude and temperature-dependent model is presented for designing an optimized device possessing balanced amelioration of all the electrical parameters. We demonstrate that employing HfO2 as the gate insulator can be a favorable choice and simultaneous use of it with proper combination of temperature and strain magnitude can achieve better device performance. Furthermore, a general model power （GMP） is derived which explicitly provides the electron effective mass as a function of the bandgap of a hydrogen passivated ASiNR under strain.

关键词： silicene double-gate field-effect-transistor non-equilibrium Green's function tight binding

A RESULT OF SUZUKI TYPE IN PARTIAL G-METRIC SPACES

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Acta Mathematica Scientia 2014年第2期34卷 274-284页

作者： Peyman SALIMI Pasquale VETRO Young researchers and Elite club Rasht BranchIslamic Azad University Università degli Studi di Palermo Dipartimento di Matematica e Informatica

Recently, Suzuki [T. Suzuki characterizes metric completeness, Proc. A generalized Banach contractlon principle that Amer. Math. Soc. 136 （2008）, 1861-1869] proved a fixed point theorem that is a generalization of the Banach contraction principle and char- acterizes the metric completeness. Paesano and Vetro [D. Paesano and P. Vetro, Suzuki＇s type characterizations of completeness for partial metric spaces and fixed points for partially ordered metric spaces, Topology Appl., 159 （2012）, 911-920] proved an analogous fixed point result for a self-mapping on a partial metric space that characterizes the partial metric O- completeness. In this article, we introduce the notion of partial G-metric spaces and prove a result of Suzuki type in the setting of partial G-metric spaces. We deduce also a result of common fixed point.

关键词： Fixed and common fixed points Suzuki fixed point theorem partial G-metricspaces

Simulation and optimization of an industrial gas condensate stabilization unit to modify LPG and NGL production with minimizing CO2 emission to the environment

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Chinese Journal of Chemical Engineering 2017年第3期25卷 338-346页

作者： M.Bahmani J.Shariati A.Nemati Rouzbahani Young researchers and Elite club Darab BranchIslamic Azad UniversityDarabIran Department of Chemical Engineering Darab BranchIslamic Azad UniversityDarabIran

In the present study, a great effort was made to improve the performance of an industrial liquefied petroleum gas(LPG) and natural gas liquid(NGL) production unit in one of the major gas refinery located at Pars special economic zone in Iran. To demonstrate and obtain the optimal condition, the unit was simulated by using a steady-state flowsheet simulator, i.e. Aspen Plus, under different operational conditions. According to the simulation results,the unit was not operational under its optimal conditions due to some defects in the cooling system at top stage of the debutanizer tower(DBT) during hot and humid seasons. Additionally, the vapor pressure of produced LPG and accordingly the amount of its flaring were decreased by reducing the temperature of debutanizer tower at top stages. In the optimization section, the DBT condenser and reboiler heat duty, temperature, and pressure were regulated as adjustable parameters. The simulation results demonstrated that by applying the optimum suggestion in the hot months, the reflux stream temperature was reached about 55 ℃ which caused an efficient increment in LPG production(about 4%) with adjusting the propane component in LPG, based on the standard range as the plant criteria. Moreover, after applying modifications, about 750 t of LPG product was saved from flaring during five hot months of the year, which resulted in 360000 USD extra annual income for the ***, from environmental point of view, this optimization caused to reduce 81 t of CO_2 emission to the environment. Therefore, the current investigation must be introduced as a friendly environmentally process.

关键词： LPG NGL Simulation Optimization CO2 emission