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Integrating data from remote sensing, geology and gravity for geological investigation in the Tarhunah area, Northwest Libya

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International Journal of Digital Earth 2008年第4期1卷 347-366页

作者： N.M.Saadi E.Aboud H.saibi K.Watanabe Laboratory of Economic Geology Faculty of EngineeringKyushu University744 MotookaFukuoka 819-0395Japan National Research Institute of Astronomy and Geophysics CairoEgypt Laboratory of Geothermics Faculty of EngineeringKyushu University744 MotookaNishi-kuFukuoka 819-0395Japan

The present work deals with the integration of remote-sensing,surface-geology and gravity-survey data to improve the structural knowledge of the Tarhunah area,northwest *** information and remote-sensing data provided information about the surface structure.A gravity survey was conducted to decipher the subsurface *** results revealed that a basin having a width of 39 to 48 km trends NE.A two-dimensional(2-D)schematic model shows that the basin gradually deepens toward the *** determined from a horizontal gradient,tilt derivative,and Euler deconvolution show a depth range of 2.5 to 7.5 *** integration and interpretation of the results indicate that volcanic activity was related to the tectonic activity of an anticlinal structure called the Jabal Uplift.

关键词： Libya Tarhunah area remote sensing gravity integration

Model variables identification of a gas turbine using a subspace approach based on input/output data measurements

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Control Theory and Technology 2021年第2期19卷 183-196页

作者： hakim Bagua Ahmed Hafaifa Abdelhamid Iratni Mouloud Guemana Applied Automation and Industrial Diagnostics Laboratory Faculty of Science and TechnologyUniversity of Djelfa17000DjelfaAlgeria Gas Turbine Joint Research Team University of Djelfa17000DjelfaAlgeria Faculty of Science and Technology University of Bordj Bou Arreridj34000Bordj Bou ArreridjAlgeria

This paper deals with a state model identification of a gas turbine used for gas transport, using a subspace approach of the state space model. This method provides a reliable and robust state representation of the model, taking advantage of its benefits in the control, monitoring, and supervision of this machine. The model for each variable is set so that the state matrices associated with the gas turbine model are determined from their real input/output data. The comparison of the obtained identification results with those of the actual turbine operation serves to validate the proposed model in this work. This numerical algorithm of the subspace identification method is full of information and more accurate in terms of residual modeling error, and expresses a very high level of confidence in the identified turbine system dynamics. Hence, the controllability and observability tests of turbine operation for different input/output variables allowed to validate the real-time operating stability of the turbine.

关键词： System identification Subspace identification State space model Gas turbine N4SID algorithm

A Discontinuous Galerkin Method for Ideal Two-Fluid Plasma Equations

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Communications in Computational Physics 2011年第2期9卷 240-268页

作者： John Loverich Ammar hakim Uri Shumlak Tech-X Corporation 5621 Arapahoe Avenue Suite ABoulder CO80303USA University of Washington Aerospace and Energetics Research ProgramSeattleWA 98195-2250USA

A discontinuous Galerkin method for the ideal 5 moment two-fluid plasma system is *** method uses a second or third order discontinuous Galerkin spatial discretization and a third order TVD Runge-Kutta time stepping *** method is benchmarked against an analytic solution of a dispersive electron acoustic square pulse as well as the two-fluid electromagnetic shock[1]and existing numerical solutions to the GEM challenge magnetic reconnection problem[2].The algorithm can be generalized to arbitrary geometries and three *** approach to maintaining small gauge errors based on error propagation is suggest.

关键词： Plasma two-fluid 5 moment discontinuous Galerkin electrostatic shock electromagnetic shock magnetic reconnection

Numerical Methods for Two-Fluid Dispersive Fast MHD Phenomena

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Communications in Computational Physics 2011年第6期10卷 183-215页

作者： Bhuvana Srinivasan Ammar hakim Uri Shumlak Aerospace and Energetics Research Program University of WashingtonSeattleWA 98195USA Tech-X Corporation 5621 Arapahoe Avenue Suite ABoulderCO 80303USA

The finite volume wave propagation method and the finite element RungeKutta discontinuous Galerkin(RKDG)method are studied for applications to balance laws describing plasma *** plasma fluid equations explored are dispersive and not *** physical dispersion introduced through the source terms leads to the wide variety of plasma *** dispersive nature of the plasma fluid equations explored separates the work in this paper from previous *** linearized Euler equations with dispersive source terms are used as a model equation system to compare the wave propagation and RKDG *** numerical methods are then studied for applications of the full two-fluid plasma *** two-fluid equations describe the self-consistent evolution of electron and ion fluids in the presence of electromagnetic *** is found that the wave propagation method,when run at a CFL number of 1,is more accurate for equation systems that do not have disparate characteristic ***,if the oscillation frequency is large compared to the frequency of information propagation,source splitting in the wave propagation method may cause phase *** Runge-Kutta discontinuous Galerkin method provides more accurate results for problems near steady-state as well as problems with disparate characteristic speeds when using higher spatial orders.

关键词： Two-fluid plasma model 5 moment discontinuous Galerkin high-resolution wave propagation dispersive source terms hyperbolic conservation laws dispersive Euler soliton Zpinch

Assessment of ship manoeuvrability by using a coupling between a nonlinear transient manoeuvring model and mathematical programming techniques

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Journal of Hydrodynamics 2013年第5期25卷 788-804页

作者： TRAN KHANH Toan OUAHSINE Abdellatif NACEUR hakim EL WASSIFI Karima Laboratoire Roberval Université de Technologie de Compiègne Laboratoire LAMIH Université de Valenciennes Université Cadi Ayyad Faculté des Sciences et Techniques

In this paper, a numerical method based on a coupling between a mathematical model of nonlinear transient ship manoeuvring motion in the horizontal plane and Mathematical Programming （MP） techniques is proposed. The aim of the proposed procedure is an efficient estimation of optimal ship hydrodynamic parameters in a dynamic model at the early design stage. The proposed procedure has been validated through turning circle and zigzag manoeuvres based on experimental data of sea trials of the 190 000- dwt oil tanker. Comparisons between experimental and computed data show a good agreement of overall tendency in manoeuvring traiectories.

关键词： ship manoeuvrability hydrodynamics coefficients nonlinear transient dynamics sensitivity analysis mathematical pro- gramming

Effect of axial load and transverse reinforcements on the seismic performance of reinforced concrete columns

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Frontiers of Structural and Civil Engineering 2019年第4期13卷 831-851页

作者： Mounir Ait BELKACEM hakim BECHTOULA Nouredine BOURAHLA Adel Ait BELKACEM Department of Earthquake Engineering National Earthquake Engineering Research Centre (C.G.S) Algiers 16005 Algeria Department of Civil Engineering LGGC Laboratory Blida 1-University Blida 09000 Algeria Department of Civil Engineering Science & Technology University (USTHB) Algiers 16111 Algeria

The aim of this research is to assess the seismic performance of reinforced concrete columns under different axial load and transverse reinforcement ratios. These two parameters are very important as for the ductility, strength, stiffness, and energy dissipation capacity for a given reinforced concrete column. Effects of variable axial load ratio and transverse reinforcement ratio on the seismic performance of reinforced concrete columns are thoroughly analyzed. The finite element computer program Seismo-Structure was used to perform the analysis of series of reinforced concrete columns tested by the second author and other researchers. In order to reflect the reality and grasp the actual behavior of the specimens, special attention was paid to select the models for concrete, confined concrete, and steel components. Good agreements were obtained between the experimental and the analytical results either for the lateral force-drift relationships or for the damage progress prediction at different stages of the loading.

关键词： reinforced concrete columns axial load transverse reinforcement ductility

Numerical Investigation of Flutter Stability in Subsonic Space Turbine Blisk with Emphasis on Cut-on/Cut-off Modes and Interblade Phase Angles

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热科学学报：英文版 2012年第6期21卷 492-499页

作者： hakim Ferria Pascal Ferrand Franois Pacull Stéphane Aubert Laboratoire de Mécanique des Fluides et d'Acoustique CNRS UMR 5509 Université de LyonUniversité Claude Bernard Lyon 1INSA Lyon 36avenue Guy de Collongue69134 EcullyFrance Fluorem 64 chemin des Mouilles69134 EcullyFrance

The so-called blisks,*** bladed disks,are characterized by very low viscous material damping and make the flutter prediction much more *** that framework,a two-dimensional numerical study of a space turbine blisk featuring complex deformation of blades and high eigenfrequency(>40kHz)is *** simulations are based on unsteady Reynolds Averaged Navier Stokes computations linearized in the frequency domain and consist in the superposition of an unsteady linear(in time)pressure field,generated by a harmonic perturbation,upon a steady nonlinear(in space)*** aerodynamic damping coefficient is calculated over a range of nodal diameters,and the blades are predicted aeroelastically ***,violent changes occur and are rather critical since sudden and large deviations in stability *** that context,the nature of the waves propagating from the cascade are *** an approach provides fundamental knowledge about the perturbations which can either propagate to the far-field(cut-on mode)or decay(cut-off mode).It is expected that the ability of the flow to damp or to amplify the blade motion is strongly affected by the way unsteady perturbations are transferred from the cascade to the *** nature of the waves are first assessed from the aforementioned linearized results,then they are evaluated analytically and finally compared.A good agreement is found despite the strong assumptions of the analytical *** results show a clear correlation between the cut-on/cut-off conditions and *** least stable configuration corresponds to cut-off mode at the inlet and no wave at the *** outgoing waves from the cascade,the blade is prone to be less stable:the energy from the blades vibration is necessarily dissipated or sent out by the cascade.

关键词：颤振稳定性数值模拟涡轮叶盘空间相位角亚音速非定常扰动叶片振动

Characteristics of fast-growing wood impregnated with nanoparticles

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Journal of Forestry Research 2020年第2期31卷 677-685页

作者： Istie Rahayu Wayan Darmawan Lukmanul hakim Zaini Esti Prihatini Forest Product Department Faculty of ForestryBogor Agricultural UniversityBogor 16680Indonesia

Falcataria moluccana or sengon is one of the fast-growing wood species widely grown in ***,its wood is low quality with low density,and poor strength,durability,and dimensional *** study determined the effects of impregnation with monoethylene glycol(MEG)and nano-SiO2 on the characteristics of sengon wood,including its dimensional stability and *** with MEG and nano-SiO2 had a significant effects on dimensional stability in terms of the weight percent gain,anti-swelling efficiency,water uptake,bulking effect,and *** impregnated wood was examined by scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy and X-ray *** results show that MEG and nano-SiO2 were distributed homogeneously into cell walls of wood treated with 0.5%MEGSiO2.

关键词： Falcataria moluccana Fast-growing species Impregnation:monoethylene glycol Nanoparticles Dimensional stability

Curcumin gum Arabic nanoparticles demonstrate potent antioxidant and cytotoxic properties in human cancer cells

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BIOCELL 2022年第3期46卷 677-687页

作者： ABDELKADER HASSANI SITI ASLINA HUSSAIN MOTHANNA SADIQ AL-QUBAISI MOHAMED LAKHDER BELFAR hakim BELKHALFA HAMID HAMMAD ENEZEI HAMID ZENTOU WISAM NABEEL IBRAHIM ABD ALMONEM DOOLAANEA Department of Pharmaceutical Technology Faculty of PharmacyInternational Islamic University MalaysiaKuantanMalaysia Department of Chemical and Environmental Engineering University Putra MalaysiaSerdang43400Malaysia Department of Chemistry Faculty of Mathematics and Material SciencesUniversity of kasdi MurbahOuarglaAlgeria UPM-MAKNA Cancer Research Laboratory Institute of BioscienceUniversity Putra MalaysiaSerdangMalaysia Scientific and Technical Research Center in Physicochemical Analysis Bou-IsmailTipazaAlgeria Department of Oral&Maxillofacial Surgery College of DentistryUniversity of AnbarRamadiIraq Department of Biomedical Sciences College of Health SciencesQU HealthQatar UniversityDohaQatar Pharmaceutical Research Unit QU HealthQatar UniversityDohaQatar

The main purpose of the study was to enhance the stability and therapeutic effects of Curcumin(Cur)through nanoformulation with gum Arabic(GA)as a coating agent through an efficient synthetic *** antioxidant properties of the developed nanoparticles(Cur/GANPs)were assessed through several in vitro assays,such asβ-carotene bleaching activity,DPPH,and nitric oxide scavenging activities in addition to evaluating its inhibitory activity on angiotensinconverting enzyme(ACE).The cytotoxicity of Cur/GANPs was evaluated in vitro using different types of human cancer cells including breast cancer(MCF7,MDA-MB231),liver cancer(HepG2),and colon cancer(HT29)*** prepared particles displayed an elliptical shape with a size ranging between 20–260 nm and a potential difference of–15 *** Cur/GANPs exhibited significant antioxidant activity compared to free curcumin when using concentrations between 31.5 and 500μg/*** Cur/GANPs also had inhibited the growth of all cancer cell lines in a proportional trend with concentrations ***,the encapsulation with gum Arabic has augmented the antioxidant and anti-neoplastic effects of ***,Cur/GANPs may have effective therapeutic properties in diseases attributed to oxidative stress like cancer and hypertension.

关键词： Curcumin Gum arabic Nanoparticles Cancer cells Antioxidants