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Soil evolution along an alluvial-loess transect in the Herat Plain,western Afghanistan

Journal of Arid Land 2022年第11期14卷 1317-1330页

作者： Farsila MAHMOUDIAN Alireza KARIMI omid bayat Department of Soil Science Faculty of AgricultureHerat UniversityHerat 3001-272806Afghanistan Department of Soil Science Faculty of AgricultureFerdowsi University of MashhadMashhad ***Iran

Afghanistan is located in the Eurasian loess belt,however,there is little information on the soils in the *** has covered the Herat Plain in western Herat City,*** the diversity of landform and parent material,there is no information on the soil and landform evolution in this *** objectives of this study were to identify the soils along a transect of different landforms in the Herat Plain and determine the role of geomorphic processes on the soil and landform *** pedons from an alluvial fan,the depression between alluvial fan and piedmont plain,saline and non-saline piedmont plains,and the flood plain of the Hariroud River,were ***,the physical-chemical properties,mineralogy,and micromorphology of the samples were *** showed that the soil parent material in the piedmont plain is loess,whereas,in the flood plain it is a combination of loess and river alluvial ***,lessivage,salinization,and gleization are the most important pedogenic *** calcification and lessivage appear to be the result of a wetter climate during the late Quaternary,whereas the present topography causes the gleization and *** coatings on carbonate nodules and iron nodules are abundant pedofeatures in the Btk(argillic-calcic)*** oxides nodules are common in the soils of the flood *** formation of palygorskite in both alluvial-and loess-derived soils implies the onset of aridity and the trend of increase in environmental aridity in the *** seems that after the formation of a well developed paleosol on the alluvial fan in a more humid climate in the past,the piedmont plain has been covered by loess deposits,and the calcification,gleization,and salinization cause the formation of weakly developed surficial *** study highlights the role of the late Quaternary climatic changes on the evolution of landforms and soils in western Afghanistan.

关键词： alluvial fan loess-derived soils paleosol gleization Hariroud River

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Genesis and soil environmental implications of intact in-situ rhizoliths in dunes of the Badain Jaran Desert,northwestern China

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Acta Geochimica 2022年第5期41卷 811-822页

作者： Qingfeng Sun Kazem Zamanian Arnaud Huguet omid bayat Hong Wang Hanan SBadawy Key Laboratory of Resource Environment and Sustainable Development of Oasis Northwest Normal University730070 LanzhouGansu ProvinceGansuPR China Key Laboratory of Eco-function Polymer Materials of the Ministry of Education Northwest Normal University730070 LanzhouGansuPR China Institute of Soil Science Leibniz University of HannoverHerrenhäuser Straße 230419 HannoverGermany Sorbonne Université CNRSEPHEUMR METISF-75005 ParisPSLFrance Department of Soil Science Isfahan University of Technology84156-83111 IsfahanIran Interdisciplinary Research Center of Earth Science Frontier Beijing Normal University100875 BeijingPR China Department of Geology Faculty of ScienceBeni-Suef University62521 Beni-SuefEgypt School of Geographical Sciences Nanjing University of Information Science and Technolog210044NanjingChina

Desert rhizoliths are generally found as weathered,broken and scattered samples on dune field surface,but rarely insitu in their initial states buried under the soil of desert in the Badain Jaran Desert,northwest *** study off ers an assessment of the morphological,mineralogical,and chemical properties of intact and in-situ rhizoliths found in soils of swales and depressions among dune *** characteristics of these rare and precious objects were assessed using optical polarizing microscopy,cathodoluminescence,scanning electronic microscopy,radiocarbon dating,and stable isotopic analyses,providing the opportunity for discussion of the rhizolith formation mechanisms and associated environmental *** and laboratory investigations showed that the in-situ intact rhizoliths were formed only in the places where Artemisia shrubs are living,and the remaining root relicts within rhizoliths belong to this *** spatial distribution of rhizoliths also suggested that low topographic positions on a landscape provided soil moisture,and redox environments favored rhizolith formation.A semi-closed redox environment in the subsoil at swales and depressions,where water is always present,along with the sandy soil texture,facilitated fast water percolation to deeper depths and *** a soil environment not only provides water for Artemisia growth,but also for the weathering of minerals such as felspars and calcite from primary carbonates,and for the decomposition of root ***,harsh climatic conditions,such as strong winds and solar radiation,led to water evaporation through dead root channels and triggered the calcification along the root *** entrapped lithogenic carbonates and to a lesser extent the decomposition of Artemisia roots provided the carbon sources for the rhizoliths formation,while the weathering of soil minerals,particularly feldspars and carbonates,was the main source of *** in the Badain Jaran des

关键词： Rhizoliths Calcification Leptic regosols Artemisia roots Decomposition Soil moisture

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Nonlinear dynamics of two degree of freedom systems with linear and nonlinear stiffnesses

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Earthquake Engineering and Engineering Vibration 2013年第3期12卷 411-420页

作者： bayat Mahmoud I.Pakar Department of Civil Engineering Mashhad Branch Islamic Azad UniversityMashhad Iran

In this study, a new analytical approach is developed to analyze the free nonlinear vibration of conservative two-degree-of-freedom （TDOF） systems. The mathematical models of these systems are governed by second--order nonlinear partial differential equations. Nonlinear differential equations were transferred into a single equation by using some intermediate variables. The single nonlinear differential equations are solved by using the first order of the Hamiltonian approach （HA）. Different parameters, which have a significant impact on the response of the systems, are considered and discussed. Some comparisons are presented to verify the results between the Hamiltonian approach and the exact solution. The maximum relative error is less than 2.2124 % for large amplitudes of vibration. It has been established that the first iteration of the Hamiltonian approach achieves very accurate results, does not require any small perturbations, and can be used for a wide range of nonlinear problems.

关键词： nonlinear vibration two-degree-of-freedom (TDOF) analytical approach Hamitonian approach (HA)

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Optimized design of a linear vibrating screen based on efficiency maximisation and mesh wear minimisation employing discrete element method

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Particuology 2024年第7期90卷 307-322页

作者： omid Afsari Kamyar Hashemnia School of Mechanical Engineering Shiraz UniversityMolla Sadra St.ShirazIran

This article investigates the combined effect and the order of influence of feed rate,inclination angle,vibration amplitude,frequency,and angle on the efficiency and mesh wear rate of a linear vibrating screen,as well as the average velocity,and mass of the accumulated *** discrete element modeling simulations were conducted using LIGGGHTS open-source code to analyze particles *** Taguchi method was employed to evaluate the combined effect of the ***,the simulation results were analyzed using analysis of *** optimal values of the parameters for maximising efficiency and minimising mesh wear were determined using grey relational *** results indicated that the most effective parameters on screening efficiency and average velocity of particles were the inclination angle,vibration angle,frequency,amplitude,and feed rate,*** most influential parameters on screen mesh wear rate were feed rate,inclination angle,vibration angle,frequency,and amplitude,respectively.

关键词： Discrete element modeling Granular material Taguchi method Vibrating screen Wear

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Automatic actor-based program partitioning

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Journal of Zhejiang University-Science C(Computers and Electronics) 2010年第1期11卷 45-55页

作者： omid BUSHEHRIAN Department of Information Technology Shiraz University of Technology Shiraz 71555-313 Iran

Software reverse engineering techniques are applied most often to reconstruct the architecture of a program with respect to quality constraints, or non-functional requirements such as maintainability or reusability. In this paper, AOPR, a novel actor-oriented program reverse engineering approach, is proposed to reconstruct an object-oriented program architecture based on a high performance model such as an actor model. Reconstructing the program architecture based on this model results in the concurrent execution of the program invocations and consequently increases the overall performance of the program provided enough processors are available. The proposed reverse engineering approach applies a hill climbing clustering algorithm to find actors.

关键词： Actor model Software reverse engineering Performance evaluation

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The surface current method in gray Dancoff factor calculation

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Nuclear Science and Techniques 2019年第6期30卷 28-34页

作者： omid Safarzadeh Faculty of Engineering Shahed University

The Dancoff correction is important in the calculation of the effective cross section of resonant isotopes in a heterogeneous system. Although the neutron current method is a simple and straightforward approach to estimate the Dancoff factor, its use is limited to the black Dancoff factor. In this paper, we expand the current method used to determine both the black and gray Dancoff factors. The method developed also relies on a neutron transport solver, where a fixed source on a fuel rod surface has an outward direction, a cosine distribution, and a constant shape. The detector is located on the surface of the rods to measure incoming and outgoing currents;therefore, there is no need to calculate the chord length, and the development, validation, and verification of the code can be omitted. The mathematical foundation of the suggested method is derived using the integral transport equation. The effects of the moderator and lattice configuration are followed by a sensitivity analysis of the Dancoff factor for several problems, including pressurized water reactor and cluster fuel assemblies. The maximum and average relative errors of the calculated results are approximately 0.3% and 0.05%, respectively.

关键词： Black Dancoff Gray Dancoff Integral transport equation Interface current Transport solver

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Effects of a flexible joint on instability of a free-free jointed bipartite beam under the follower and transversal forces

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第9期10卷 1252-1262页

作者： Saied IRANI omid KAVIANIPOUR Department of Aerospace Engineering K.N.Toosi University of Technology

This paper deals with the problem of the instability regions of a free-free flexible jointed bipartite beam under the follower and transversal forces as a realistic simulation of a two-stage aerospace structure. The aim of this study is to analyze the effects of the characteristics of a flexible joint on the beam instability to use maximum bearable propulsion force. A parametric study is conducted to investigate the effects of the stiffness and the location of the joint on the critical follower force by the Ritz method and the Newmark method, then to research the vibrational properties of the structure. It has been shown that the nature of instability is quite unpredictable and dependent on the stiffness and the location of the joint. The increase of the follower force or the transversal force will increase the vibration of the model and consequently cause a destructive phenomenon in the control system of the aerospace structure. Furthermore, this paper introduces a new concept of the parametric approach to analyze the characteristics effects of a flexible two-stage aerospace structure joint design.

关键词： Two stage to orbit launch vehicle (TSTO LV) Beam instability Follower force Ritz's method Newmark's method

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Correlating thermal conductivity of pure hydrocarbons and aromatics via perceptron artificial neural network (PANN) method

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Chinese Journal of Chemical Engineering 2017年第5期25卷 547-554页

作者： Mostafa Lashkarbolooki Ali Zeinolabedini Hezave Mahdi bayat School of Chemical Engineering Babol University of Technology Islamic Azad University Dashtestan Branch Department of Chemical Engineering Faculty of EngineeringUniversity of Bojnord

Accurate estimation of liquid thermal conductivity is highly necessary to appropriately design equipments in different industries. Respect to this necessity, in the current investigation a feed-forward artificial neural network(ANN) model is examined to correlate the liquid thermal conductivity of normal and aromatic hydrocarbons at the temperatures range of 257–338 K and atmospheric pressure. For this purpose, 956 experimental thermal conductivities for normal and aromatic hydrocarbons are collected from different previously published *** the modeling stage, to discriminate different substances, critical temperature(Tc), critical pressure(Pc)and acentric factor(ω) are utilized as the network inputs besides the temperature. During the examination, effects of different transfer functions and number of neurons in hidden layer are investigated to find the optimum network architecture. Besides, statistical error analysis considering the results obtained from available correlations and group contribution methods and proposed neural network is performed to reliably check the feasibility and accuracy of the proposed method. Respect to the obtained results, it can be concluded that the proposed neural network consisted of three layers namely, input, hidden and output layers with 22 neurons in hidden layer was the optimum ANN model. Generally, the proposed model enables to correlate the thermal conductivity of normal and aromatic hydrocarbons with absolute average relative deviation percent(AARD), mean square error(MSE), and correlation coefficient(R^2) of lower than 0.2%, 1.05 × 10^(-7) and 0.9994, respectively.

关键词： Thermal conductivity Artificial neural network Critical properties Hydrocarbons Aromatics

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Graphene quantum dots decorated rutile TiO_2 nanoflowers for water splitting application

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Journal of Energy Chemistry 2018年第1期27卷 306-310页

作者： A.bayat E.Saievar-Iranizad Department of physics Faculty of Basic Science Tarbiat Modares University

Flower like rutile TiO_2 films were decorated with green-photoluminescent graphene quantum dots（GQDs） and photovoltaic properties were investigated for water splitting application. Rutile TiO_2 nanoflowers（NFs） and GQDs（average width of^12 nm） synthesized separately using a hydrothermal method and TiO_2 NFs were decorated with various amounts of GQDs solution（x = 5, 10, 15 and 20 μL） by spin coating. Optical characterization reveals that GQDs are highly luminescent and absorb UV and visible light photons with wavelengths up to 700 nm. GQDs-x/TiO_2 electrode shows a photocurrent enhancement of ~95% compared to pristine TiO_2 NFs for the optimum sample（x = 15 μL） at an applied potential of P = 0 V using 1 M Na_2SO_4 solution as electrolyte.

关键词： Graphene quantum dotsTiO2 nanoflowers Water splitting Photoanode

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Characterization of gas-liquid-solid fluidized beds by S statistics

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Particuology 2016年第6期14卷 135-142页

作者： omid Arjmandi-Tash Reza Zarghami Multiphase Systems Research Lab Oil and Gas Processing Centre of Excellence School of Chemical Engineering College of Engineering University of TehranP.O. Box 11155/4563 Tehran lran

The hydrodynamics of a gas-liquid-solid fluidized bed was investigated by applying the S statistics method to pressure fluctuations measured under various operating conditions in a laboratory-scale bed. S statistics tests reveal the existence of three transition velocities, especially at low gas velocities. Four distinct fluidization regimes, namely, the compacted bed, agitated bed and coalesced and discrete bubble regimes were detected. A comparison of reconstructed attractors of pressure fluctuations measured at different axial positions along the riser and with various solid loadings showed significant differences in the signals compared before fluidization, especially at minimum liquid agitation velocity. Close to the minimum liquid fluidization velocity and high liquid velocities, the variation in particle size has an insignificant effect on the bed hydrodynamics. Therefore, S statistics is a reliable method to demar- cate different fluidization regimes and to characterize the influence of various operating conditions on the hydrodynamics of gas-liquid-solid fluidized beds. The method is applicable in large-scale industrial installations to detect dynamic changes within a bed, such as regime transitions or agglomeration.

关键词： Gas-liquid-solid fluidized bed Pressure fluctuation Reconstructed attractor S statistics Transition velocity

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