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The impact of Persian oak (Quercus brantii Lindl.) on soil characteristics in a declining forest

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Journal of Forestry Research 2020年第6期31卷 2359-2366页

作者： reza Soleimani ahmad Hosseini Crop and Horticultural Science Research Department Ilam Agricultural and Natural Resources Research and Education CenterAREEOIlamIran Forests and Rangelands Research Department Ilam Agricultural and Natural Resources Research and Education CenterAREEOIlamIran

Root activity has an important impact on soil development but we have little knowledge of the interaction of the root zone and soil genetic *** aim of this investigation was to study the interactions between soil chemical characteristics and root zone processes in a declining Persian oak forest(Quercus brantii Lindl.).A randomized complete block design was used to investigate the long-term eff ect of Persian oak on soil horizons,and the chemical and biological properties in two soil zones(under and outside the canopy).Results indicate that the rhizosphere zone had signifi cantly higher total organic carbon(TOC)than outside the canopy soil in the upper soil *** subsurface horizons,water-extractable organic carbon values were signifi cantly higher in rhizosphere than in non-rhizospheric *** biomass carbon(MBC)values in the rhizospheric zone decreased from the fi rst to the second *** MBC/TOC ratio indicated signifi-cant diff erences between the rhizosphere and soils outside of the canopy,with the exception of the subsurface *** the subsurface horizon of the rhizosphere,there was greater respiration of organic carbon(ΣCO 2/TOC)than in outside of canopy *** addition,root processes infl uenced pH,nitrogen fractions,and availability of phosphorus,potassium,iron,zinc and *** erences in soil characteristics between rhizospheric and non-rhizospheric zones were signifi cant in surface horizons due to higher root density than in deeper soil *** fi ndings indicate that Persian oak(Quercus brantii Lindl.)roots infl uenced the main soil chemical properties,even in calcareous soils.

关键词： Declining forest Persian oak Rhizosphere Soil horizons

Global stability analysis of computer networks with arbitrary topology and time-varying delays

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Journal of Zhejiang University-Science C(Computers and Electronics) 2010年第3期11卷 214-226页

作者： Behrooz rezaIE Mohammad-reza JAHED motlagh Siavash KHORSANDI Morteza ANALOUI Deparment of Electrical Engineering Iran University of Science and Technology Department of Computer Engineering and Information Technology Amirkabir University of Technology Deparment of Computer Engineering Iran University of Science and Technology

In this paper,we determine the delay-dependent conditions of global asymptotic stability for a class of multi-dimensional nonlinear time-delay systems with application to computer communication networks. A nonlinear delayed model is considered for a rate-based congestion control system of a heterogeneous network with arbitrary topology and time-varying delays. We propose a Lyapunov-based method to obtain a sufficient condition under which global asymptotic stability of the equilibrium is guaranteed. The main contribution of the paper lies in considering time variations of delays in a heterogeneous network which may be applicable in actual networks. Moreover,we obtain conditions for Internet-style networks with multi-source multi-link topology. We first prove the stability for a class of nonlinear time-delay systems. Then,we apply the results to a Kelly's rate-based ap-proximation of the congestion control system.

关键词： Intemet congestion control Global stability Nonlinear time-delay system Time-varying delay

Wet-Cupping Is Effective on Persistent Nonspecific Low Back Pain: A Randomized Clinical Trial

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Chinese Journal of Integrative Medicine 2019年第7期25卷 502-506页

作者： Mohsen Mardani-Kivi reza Montazar Mohammad Azizkhani Keyvan Hashemi-motlagh Department of Orthopedic Guilan University of Medical Sciences Rasht Iran General Practitioner Traditional Medicine Specialist Tehran Iran Orthopedic Research Center Rasht Iran

Objective: To compare the possible effects of wet-cupping therapy with conventional therapy on persiste nt non specific low back pain (PNSLBP). Methods: In this ran domized clinical trial, 180 participa nts with the mean age of 45 ±10 years old, who had been suffering from PNSLBP were randomly assigned to wet-cupping and conventional groups using random blook. The wet-cupping group was treated with two separate sessions (4 weeks in total) on the inter-scapular and sacrum area. In the conventional group, patients were conservatively treated using rest (6 weeks) and oral medicati ons (3 weeks). The primary and the sec on dary outcome were the qua ntity of disability using Oswestry Disability Index (ODI), and pain intensity using Visual Analogue Scale (VAS), respectively. Results: There was no significant difference in demographic characteristics (age, gender, and body mass index) between the two groups (P>0.05). Therapeutic effect of wet-cupping therapy was comparable to conventional treatment in the 1st month follow-up visits (P<0.05). The functional outcomes of wet-cupping at the 3rd and 6th month visits were significantly increased compared to the conventional group. Final ODI scores in the wet-cupping and conventional groups were 16.7 ±5.7 and 22.3 ±4.5, respectively (P<0.01). Conclusion: Wet-cupping may be a proper method to decrease PNSLBP without any conventional treatment. The therapeutic effects of wet-cupping can be longer lasting than conventional therapy.(Registration No. IRCT2013021672741).

关键词： low back pain chronic wet-cupping therapy traditi onal medici ne Chin ese medici ne alter native medicine conservative treatment randomized clinical trial

Magnetic metal organic framework for pre-concentration of ampicillin from cow milk samples

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Journal of Pharmaceutical Analysis 2020年第4期10卷 365-375页

作者： ahmad reza Bagheri Mehrorang Ghaedi Chemistry Department Yasouj UniversityYasouj75918-74831Iran

The aim of this study is a present of a simple solvothermal synthesis approach to preparation of Cu-based magnetic metal organic framework(MMOF)and subsequently its application as sorbent for ultrasound assisted magnetic solid phase extraction(UAMSPE)of ampicillin(AMP)from cow milk samples prior to high performance liquid chromatography-Ultraviolet(HPLC-UV)*** of prepared MMOF were fully investigated by different techniques which showed the exclusive properties of proposed sorbent in terms of proper functionality,desirable magnetic property and also high specific surface *** influential factors on extraction recovery including sorbent dosage,ultrasonic time,washing solvent volume and eluent solvent volume were assessed using central composite design(CCD)based response surface methodology(RSM)as an operative and powerful optimization *** is the first report for determination of AMP using *** proposed method addressed some drawbacks of other methods and sorbents for determination of *** presented method decreases the extraction time(4 min)and also enhances adsorption capacity(250 mg/g).Moreover,the magnetic property of presented sorbent(15 emu/g)accelerates the extraction process which does not need filtration,centrifuge and precipitation *** the optimized conditions,the proposed method is applicable for linear range of 1.0-5000.0 μg/L with detection limit of 0.29 μg/L,satisfactory recoveries(≥95.0%)and acceptable repeatability(RSD less than 4.0%).The present study indicates highly promising perspectives of MMOF for highly effective analysis of AMP in complicated matrices.

关键词： Magnetic metal organic framework Ultrasound assisted magnetic solid phase extraction Ampicillin Cow milk samples

Isoparametric Boundary Element Method Applied to the Rectangular and Delta Hydrofoils near the Free Surface

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China Ocean Engineering 2010年第2期24卷 321-331页

作者： Hassan GHASSEMI ahmad reza KOHANSAL Faculty of Marine Technology Amirkabir University of Technology

In this paper, the hydrodynamic characteristics and flow field around rectangular and delta hydrofoils, moving with a constant speed beneath the free surface are numerically studied by means of isoparametric boundary element method （IBEM）. The quantities （source and dipole strengths） and the geometry of the dements are represented by a linear distribution. Two types of three-dimensional hydrofoils （rectangular and delta） are selected with NACA4412 and symmetric Joukowski sections. Some numerical results of pressure distribution, lift, wave-making drag coefficients and velocity field around the hydrofoils are presented. Also, the wave pattern due to moving hydrofoil is predicted at different operational conditions. Comparisons are made between computational results obtained through this method and those from the experimental measurements and other numerical results which reveal good agreement.

关键词： isoparametric boundary element method delta and rectangular hydrofoils hydrodynamic characteristics free surface

Burial and thermal maturity modeling of the Middle Cretaceous-Early Miocene petroleum system,Iranian sector of the Persian Gulf

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Petroleum Science 2015年第3期12卷 367-390页

作者： Zahra Sadat Mashhadi ahmad reza Rabbani Mohammad reza Kamali Maryam Mirshahani ahmad Khajehzadeh Petroleum Engineering Department Amirkabir University of Technology Research Institute of Petroleum Industry (RIPI)

The Cretaceous Kazhdumi and Gurpi forma- tions, ahmadi Member of the Sarvak Formation, and Paleogene Pabdeh Formation are important source rock candidates of the Middle Cretaceous-Early Miocene pet- roleum system in the Persian Gulf. This study characterizes generation potential, type of organic matter, and thermal maturity of 262 cutting samples （marls and argillaceous limestones） from these rock units taken from 16 fields in the Iranian sector of the Persian Gulf. In addition, the burial and thermal histories of these source rocks were analyzed by one-dimensional basin modeling. Based on the total organic carbon and genetic potential values, fair hydro- carbon generation potential is suggested for the studied samples. Based on Tma~ and vitrinite reflectance values, the studied samples are thermally immature to mature for hydrocarbon generation. The generated models indicate that studied source rocks are immature in central wells. The Gurpi and Pabdeh formations are immature and the ahmadi Member and Kazhdumi Formation are early mature in the western wells. The Pabdeh Formation is within the main oil window and other source rocks are at the late oil window in the eastern wells. The hydrocarbon expulsion from the source rocks began after deposition of related caprocks which ensures entrapment and preserva- tion of migrated hydrocarbon.

关键词： Persian Gulf. Kazhdumi Formation ahmadiMember Gurpi Formation Pabdeh Formation - MiddleCretaceous-Early Miocene petroleum system

Synthesis of Cobalt Chromite Nanoparticles by Thermolysis of Mixed Cr^(3+) and Co^(2+) Chelates of 2-Mercaptopyridin N-Oxide

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Nano-Micro Letters 2012年第2期4卷 83-89页

作者： Mohammad.Edrissi ahmad reza Keshavarz Chemical Engineering Department Amirkabir University of Technology

Pure greenish-blue cobalt chromite(Co Cr/_2O_4) nanoparticles with narrow particle range of 4.1±1.9nm and surface area of 78.2 m2·g-1were synthesized through mixed chelates thermolysis of corresponding metals using 2-Mercaptopyridine N-oxide sodium salt as chelating agent. During the thermolysis procedure,high amount of gases were emitted that led to the formation of nanoparticles with high surface area. The product was characterized by TGA, DTG, XRD, TEM, SEM, LLS, BET and chemical analysis. Design of experiments was performed to fulfill the two levels L_4 Taguchi design. It was found that the temperature and time of thermolysis process have significant effect on the particle size reduction. The Oxidation of trichloroethylene was carried out over Co Cr_2O_4 nanocrystallite. Catalytic activity analysis revealed that the synthesis Co Cr_2O_4 possesses high catalytic activity for this process.

关键词： CoCr2O4 Nanoparticle Chelates Termolysis Taguchi experimental design Combustion of trichloroethylene

Preparation of nanocrystalline γ-Al_2O_3 catalyst using different procedures for methanol dehydration to dimethyl ether

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Journal of Natural Gas Chemistry 2011年第3期20卷 334-338页

作者： ahmad reza Keshavarz Mehran rezaei Fereydoon Yaripour Catalyst and Advanced Materials Research Laboratory Chemical Engineering Department Faculty of Engineering University of Kashan Institute of Nanoscience and Nanotechnology University of Kashan Catalyst Research Group Petrochemical Research & Technology Company National Petrochemical Company (NPC)

A series of nanocrystalline γ-alumina are synthesized by different procedures, namely, thermal decomposition method （sample A）, precipita-tion method （sample B） and sol-gel method using sucrose and hexadecyltrimethyl ammonium bromide （CTAB） as templates （samples C and D, respectively）. Textural and acidic properties of γ-alumina samples are characterized by XRD, N2 adsorption-desorption and NH3-TPD techniques. Vapor-phase dehydration of methanol into dimethyl ether is carried out over these samples. Among them, sample C shows the highest catalytic activity. NH3-TPD analysis reveals that the sample with smaller crystallite size possesses higher concentration of medium acidic sites and consequently higher catalytic activity. Thermal decomposition method leads to decrease in both surface area and moderate acidity, therefore it is the cause of lower catalytic activity.

关键词： methanol dehydration dimethyl ether gama alumina sol-gel

Coefficient of consolidation by end of arc method

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Journal of Central South University 2015年第1期22卷 332-337页

作者： Mohsen Abbaspout reza Porhoseini Kazem Barkhordari ahmad Ghorbani School of Technical & Engineering Department of Civil Engineering Yazd UniversityUniversity Blvd School of Mining and Metallurgy Department of Mine Exploration Yazd UniversityUniversity Blvd

One of the most important issues in geotechnical engineering is excess pore pressure caused by clay soil loading and consolidation. Regarding uncertainties and complexities, this issue has long been the subject of attention of many researchers. In this work, a one-dimensional consolidation apparatus was equipped in a way that pore water pressure and settlement could be continuously read and recorded during consolidation process under static loading. The end of primary consolidation was obtained using water pressure changes helping to present a new method for determining the end of primary consolidation and consolidation coefficient. This method was then compared with two classical theory methods of lg t and t. Using Terzaghi's theory, the way of pore pressure dissipation for lg t, t and the new method was found and compared with experimental results. It is concluded that the new method has better results.

关键词： one-dimensional consolidation of soil excess pore pressure end primary consolidation consolidation coefficient static loading