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Functional relationships of nodulation response and biomass production at nursery stages of two fast-growing, leguminous-multipurpose tree species in Bangladesh: Albizia saman and Leucaena leucocephala

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Forestry Studies in China 2013年第4期15卷 274-285页

作者： Md.Salim AZAD samir mondol Md.Abdul MATIN Forestry and Wood Technology Discipline Khulna University Faculty of Forest Sciences and Forest Ecology Georg-August University

This study was carried out to assess the relationship of the status of nodulation(i.e., the number of nodules, their shape and size) in root and biomass production of plant growth parameters(i.e., number of leaves, root and shoot lengths, root biomass and shoot biomass) in Albizia saman and Leucaena leucocephala. The assessment started 60 days after seeding. The study revealed that nodulation response and biomass production in both species showed significant differences over time(p < 0.05) in all variables except in the root-shoot ratio(oven-dry) of L. leucocephala. The study also showed significant differences(p < 0.05) in nodule formation and biomass production at the end of the study period between the two species except in the number of nodules and leaves and the green root-shoot ratio. There were strong positive correlations between nodule formation and biomass production, i.e., the number of nodules and the age of plants, the number of nodules and leaves, as well as the number of nodules and biomass(root biomass and shoot biomass) in both species. The results obtained using principal component analysis(PCA) and correlation coefficients of the different characteristics of nodulation and biomass production were similar in both species. The PCA showed that shoot biomass(shoot green weight and shoot oven-dry weight) is positively correlated with PC1(with an eigenvalue of 7.50) and root length is positively correlated with PC2(with an eigenvalue of 0.19) in the case of A. saman. In the case of L. leucocephala, the PCA revealed that root biomass(root green weight and root oven-dry weight), shoot biomass and shoot length are also positively correlated with PC1, while nodule formation and the number of leaves are positively correlated with PC2(with an eigenvalue PC1 of 6.92 and PC2 of 0.49).

关键词： leguminous tree species,nitrogen fixation,nodule formation nursery practice seedling growth

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Stabilization and Synchronization of Discrete-time Fractional Chaotic Systems with Non-identical Dimensions

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Acta Mathematicae Applicatae Sinica 2021年第3期37卷 523-538页

作者： samir BENDOUKHA Department of Electrical Engineering College of EngineeringYanbuTaibah UniversitySaudi Arabia

This paper investigates the stabilization and synchronization of two fractional chaotic maps proposed recently,namely the 2D fractional Hénon map and the 3D fractional generalized Hénon *** show that although these maps have non–identical dimensions,their synchronization is still *** proposed controllers are evaluated experimentally in the case of non–identical orders or time–varying *** methods are used to illustrate the results.

关键词： discrete chaos fractional discrete calculus Hénon based maps stabilization synchronization

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DUALITY OF GENERALIZED DUNKL-LIPSCHITZ SPACES

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Acta Mathematica Scientia 2017年第6期37卷 1567-1593页

作者： samir KALLEL Department of Mathematics Higher Institute of Computer Sciences and Mathematics of MonastirMonastir University5000 MonastirTunisia

Abstract The aim of this paper is to prove duality and reflexivity of generalized Lipschitz spaces ∧κα,p,q（R）, α ∈R and 1≤〈 p, q ≤∞, in the context of Dunkl harmonic analysis.

关键词： Dunkl operator duality Herz spaces heat transform Dunkl transform gen-eralized Dunkl-Lipschitz spaces

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Snapthrough response of an innovative symmetric bistable composite wing

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Acta Mechanica Sinica 2024年第9期40卷 68-82页

作者： Sara Hijazi samir Emam Department of Mechanical Engineering American University of SharjahSharjah PO Box 26666United Arab Emirates

This study presents a numerical investigation into the equilibrium shapes and snapthrough response of an innovative bistable symmetric composite *** proposed design is a compound plate that consists of a symmetric flat platform followed by a winglet that utilizes the modified hybrid bistable symmetric laminate recently developed in the *** hybrid layup of the winglet resolves the issue of losing the bistability of the unsymmetric laminate when attached to another *** approximate analytical model based on the Rayleigh-Ritz method is developed for the compound plate that considers the geometric nonlinearity,the clamping conditions at the wing root,and the compatibility conditions at the *** static equilibrium positions predicted by the model were verified against the ABAQUS finite element(FE)results and an excellent agreement was *** influence of the geometrical and material parameters of the proposed design on the static equilibrium shapes and the snapthrough response was *** following parameters were considered:the length ratio of the flat plate to the bistable winglet,the thickness and location of the bidirectional glass epoxy layers,the load location,and the wing’s taperness and aspect *** parameters were found significant,and their effects were *** novelty of this work is that it presents the equilibrium shapes and the snapthrough response of a bistable laminate as a part of a bigger compliant structure,which mimics the scenario in real-life applications.

关键词： Compound laminate Bistable wing Hybrid symmetric laminates Snapthrough

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The effects of exhaust air vent location on thermal comfort inside a residential building equipped with an evaporative cooling system

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Building Simulation 2021年第4期14卷 1063-1075页

作者： rmin Saraei samir Farid Moujaes Department of Mechanical Engineering College of EngineeringUniversity of Nevada Las VegasLas VegasNV89154USA

The location of exhaust air vents of an evaporative cooling system can have significant effects on providing thermal comfort and controlling humidity, temperature and air distribution in buildings. In the current study, four different strategies have been evaluated for exhaust air vent locations to provide the optimum thermal comfort inside a typical residential house. This study provides a numerical solution for temperature and relative humidity profiles in the residential house and within the living space in each room typically at a height of 1.8 m or less. By evaluating different exhaust air vent locations in a room, the best strategy(ies) to provide more appropriate thermal comfort condition and obtained and as a conclusion, the exhaust vents should be located on furthest wall away from the entrance of the room and in the middle. The results provided in the current study can eventually be applied in the design of evaporative cooler exhaust vent systems in residential buildings and lead to improve the performance of these systems.

关键词： thermal comfort CFD evaporative cooling system exhaust air vents

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Finite Elementθ-Schemes for the Acoustic Wave Equation

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Advances in Applied Mathematics and Mechanics 2011年第2期3卷 181-203页

作者： samir Karaa Department of Mathematics and Statistics Sultan Qaboos UniversityP.O.Box 36Al-Khod 123MuscatSultanate of Oman

In this paper,we investigate the stability and convergence of a family of implicit finite difference schemes in time and Galerkin finite element methods in space for the numerical solution of the acoustic wave *** schemes cover the classical explicit second-order leapfrog scheme and the fourth-order accurate scheme in time obtained by the modified equation *** derive general stability conditions for the family of implicit schemes covering some well-known CFL *** error estimates are *** sufficiently smooth solutions,we demonstrate that the maximal error in the L^(2)-norm error over a finite time interval converges optimally as O(h^(p+1)+∆t^(s)),where p denotes the polynomial degree,s=2 or 4,h the mesh size,and∆t the time step.

关键词： Finite element methods discontinuous Galerkin methods wave equation implicit methods energy method stability condition optimal error estimates

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Simulation and analysis of resin flow in injection machine screw

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第3期9卷 338-345页

作者： Ling-feng LI samir MEKID College of Mechanical and Energy Engineering Zhejiang University Hangzhou 310027 China School of Mechanical Aerospace and Civil Engineering University of Manchester Manchester UK

A method with simulation and analysis of the resin flow in a screw is presented to ease the control of some problems that may affect the efficiency and the quality of the product among existing screws in an injection machine. The physical model of a screw is established to represent the stress, the strain, the relationship between velocity and stress, and the temperature of the cells. In this paper, a working case is considered where the velocity and the temperature distributions at any section of the flow are obtained. The analysis of the computational results shows an ability to master various parameters depending on the specifications.

关键词： Screw Plasticity Velocity distribution Temperature distribution

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BEZIER SPLINES INTERPOLATION ON STIEFEL AND GRASSMANN MANIFOLDS

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Journal of Computational Mathematics 2024年第6期42卷 1554-1578页

作者： Ines Adouani Chafik samir Department of Mathematics University of SousseTunisia LIMOS-CNRS University of Clermont AuvergneFrance

We propose a new method for smoothly interpolating a given set of data points on Grassmann and Stiefel manifolds using a generalization of the De Casteljau *** that end,we reduce interpolation problem to the classical Euclidean setting,allowing us to directly leverage the extensive toolbox of spline *** interpolated curve enjoy a number of nice properties:The solution exists and is optimal in many common *** applications,the structures with respect to chosen Riemannian metrics are detailed resulting in additional computational advantages.

关键词： Optimization B´ezier spline Curve fitting Grassmann manifolds Stiefel manifolds Canonical metrics

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Mechanisms of alcohol-mediated hepatotoxicity in human-immunodeficiency-virus-infected patients

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World Journal of Gastroenterology 2011年第20期17卷 2500-2506页

作者： Gyongyi Szabo samir Zakhari Department of Medicine LRB-208 University of Massachusetts Medical School National Institute on Alcohol Abuse and Al coholism National Institutes of Health

Clinical observations have demonstrated that excessive chronic alcohol use negatively affects human immuno- deficiency virus (HIV) infection and contributes to the liver manifestations of the disease, even in HIV mono- infection. HIV/hepatitis C virus (HCV) co-infection is as- sociated with increased progression of HVC liver disease compared to HCV infection alone, and both of these are negatively affected by alcohol use. Recent data suggest that alcohol use and HIV infection have common targets that contribute to progression of liver disease. Both HIV infection and chronic alcohol use are associated with increased gut permeability and elevated plasma levels of lipopolysaccharide; a central activator of inflammatory responses. Both alcoholic liver disease and HIV infec tionresult in non-specific activation of innate immunity, proinflammatory cytokine cascade upregulation, as well as impaired antigen presenting cell and dendritic cell functions. Finally, alcohol, HIV and antiretroviral therapyaffect hepatocyte functions, which contributes to liver damage. The common targets of alcohol and HIV infection in liver disease are discussed in this minireview.

关键词： Hepatitis C virus Hepatitis B virus Liver Intestine Inflammation

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Spatial Variability and Cartography of Maximum Annual Daily Rainfall under Different Return Periods in Northern Algeria

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Journal of Mountain Science 2015年第6期12卷 1403-1421页

作者： MEDDI Mohamed TOUMI samir National High School of Hydraulic (ENSH)

The estimation of precipitation quantiles has always been an area of great importance to meteorologists, hydrologists, planners and managers of hydrotechnical infrastructures. In many cases, it is necessary to estimate the values relating to extreme events for the sites where there is little or no measurement, as well as their return periods. A statistical approach is the most used in such cases. It aims to find the probability distribution that best fits the maximum daily rainfall values. In our study, 231 rainfall stations were used to regionalize and find the best distribution for modeling the maximum daily rainfall in Northern Algeria. The L-moments method was used to perform a regionalization based on discordance criteria and homogeneity test. It gave rise to twelve homogeneous regions in terms of LCoefficient of variation(L-CV), L-Skewness(L-CS) and L-Kurtosis(L-CK). This same technique allowed us to select the regional probability distribution for each group using the Z statistic. The generalized extreme values distribution(GEV) was selected to model the maximum daily rainfall of 10 groups located in the north of the steppe region and the generalized logistic distribution(GLO) for groups representing the steppes of Central and Western Algeria. The study of uncertainty by the bias and RMSE showed that the regional approach is acceptable. We have also developed maximum daily rainfall maps for 2, 5, 10, 20, 50 and 100 years return periods. We relied on a network of 255 rainfall stations. The spatial variability of quantiles was evaluated by semi-variograms. All rainfall frequency models have a spatial dependence with an exponential model adjusted to the experimental semi-variograms. The parameters of the fitted semi-variogram for different return periods are similar, throughout, while the nugget is more important for high return periods. Maximum daily rainfall increases from South to North and from West to East, and is more significant in the coastal areas of ea

关键词： Annual maximum daily rainfall Regionalisation L-moments Mapping Northern Algeria

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