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The effect of multi-intermediate bands on the behavior of an InAs_(1-x)N_x/GaAs(1-y)Sb_y quantum dot solar cell

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Journal of Semiconductors 2015年第4期36卷 1-6页

作者： Abou El-Maaty M.Aly a.nasr Power Electronics and Energy Conversion Department ERINRCB College of Computer Qassim University Radiation Engineering Department NCRRTAtomic Energy Authority

A mathematical model of quantum dot intermediate band solar cells （QDIBSCs） is investigated using two intermediate bands （IBs）. These two IBs arise from the quantum dot （QD） semiconductor material within the bandgap energy. Some parameters such as the width of the QD （WQD） and the barrier thickness or the inter-dot distances between the QDs （BT） are studied to show their influence on the performance of the QDIBSC. The timeindependent Schr6dinger equation, which is solved using the Kronig-Penney model, is used to determine the posi- tion and bandwidth energies of the two IBs. In our proposed model, the cubic shape of the QDs from InAs0.9N0.1 and the barrier or host semiconductor material from GaAs0.98Sb0.02 are utilized. It is shown from the results obtained that changing the parameters WQD and Bx has more influence on the bandwidth energy for the first IB, A 1, than in the case of the second IB, A2. The optimum power conversion efficiencies （PCEs） of the QDIBSCs with two IBs for the model under study are 58.01% and 73.55% at 1 sun and maximum solar concentration, respectively. One can observe that, in the case of the two IBs, an improvement of the PCE is achieved.

关键词： intermediate bands solar cells quantum dots efficiency solar concentration

Lower extremity injuries in vehicle-pedestrian collisions using a legform impactor model

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第2期11卷 97-105页

作者： A.ABVABI a.nasr A.NOORPOOR M.S.KIASAT Department of Automotive Engineering Iran University of Science and TechnologyTehranIran School of Railway Engineering Iran University of Science and TechnologyTehranIran Faculty of Marine Technology Amirkabir University of TechnologyTehranIran

Though the bumper of a vehicle plays a major role in protecting the vehicle body against damage in low speed impacts, many bumpers, particularly in large vehicles, are too stiff for pedestrian protection. In designing a bumper for an automobile, pedestrian protection is as important as bumper energy absorption in low speed collisions. To prevent lower extremity injuries in car-pedestrian collisions, it is important to determine the loadings that car front structures impart on the lower extremities and the mechanisms by which injury is caused by these loadings. The present work was focused on gaining more insight into the injury mechanisms leading to both ligament damage and bone fracture during bumper-pedestrian collisions. The European Enhanced Vehicle-safety Committee （EEVC） legform impactor model was introduced and validated against EEVCAVG17 criteria. The collision mechanism between a bumper and this legform impactor was investigated numerically using LS-DYNA software. To identify the effect of the bumper beam material on leg injuries, four analyses were performed on bumpers that had the same assembly but were made from different materials.

关键词： Finite element model (FEM) Legform impactor Pedestrian safety Lower extremity injury Composite bumper

A New Reliable System For Managing Virtual Cloud Network

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Computers, Materials & Continua 2022年第12期73卷 5863-5885页

作者： Samah Alshathri Fatma M.Talaat Aida a.nasr Department of Information Technology College of Computer and Information SciencesPrincess Nourah bint Abdulrahman UniversityP.O.Box 84428Riyadh 11671Saudi Arabia Faculty of Artificial Intelligence Kafrelsheikh UniversityKafrelsheikhEgypt Faculity of Computers and Informatics Tanta UniversityTantaEgypt

Virtual cloud network(VCN)usage is popular today among large and small organizations due to its safety and ***,it makes all resources in the company work as one *** also facilitates sharing of files and applications without ***,cloud providers face many issues in managing the VCN on cloud computing including these issues:Power consumption,network failures,and data *** issues often occur due to overloaded and unbalanced load *** this paper,we propose a new automatic system to manage VCN for executing the *** new system calledMulti-User Hybrid Scheduling(MUSH)can solve running issues and save power during workflow *** consists of three phases:Initialization,virtual machine allocation,and task scheduling *** MUSH system focuses on the execution of the workflow with deadline ***,it considers the utilization of virtual *** new system can save makespan and increase the throughput of the execution operation.

关键词： Virtual network scheduling reliability VM allocation cloud computing

Thermal oil recovery factors from sandpacks of variable mineralogy

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Petroleum Research 2023年第4期8卷 481-489页

作者： Viacheslau Y.Kudrashou Hisham a.nasr-El-Din Slippery Rock University United States Texas A&M University United States

S Steam injection is commonly used for production of viscous crude *** rock often contains clay *** nature of steam and clay minerals may lead to formation *** work in-vestigates oil recovery and changes in petrophysical properties as a function of the ***-packs with quartz,calcite,feldspar,kaolinite,smectite,and illite were prepared for steam injection *** of the steamed sandpacks was determined using coreflood *** composition of the produced aqueous samples was determined using ICP-OES(inductively coupled plasma-optical emission spectroscopy).Morphology of the rock samples was studied using SEM-EDs(scanning electron microscope-energy dispersive X-ray spectroscopy).Mineralogy and elemental content of the solid samples were determined using XRD(X-ray diffraction)analysis and XRF(X-ray fluorescence)*** was found that aqueous phase samples produced from clay-rich sandpacks tend to have higher pH than samples produced from samples without clay *** recovery factors for 100%quartz case was determined to be 65 wt%.Calcite-and feldspar-rich sandpacks produced 56 and 61 wt%of oil *** with clay fractions have shown the lowest oil recovery-39,29,and 28 wt%for kaolinite-,smectite-,and illite-rich samples *** dissolution and pre-cipitation were the dominant damaging mechanism for quartz and calcite ***-rich sandpack demonstrated signs of structural destruction of the mineral and fines ***'s effect on oil recovery was found to be associated with fines *** hydration and swelling in presence of steam was the dominant formation damage effect on the oil *** interaction with illite-rich sandpack caused formation of amorphous *** paper presents oil recovery factors as a function of injected pore volume(PV)of steam for sandpacks of different *** results characterize petroph

关键词： Steam injection Oilrecovery Kaolinite Smectite Ilite Sandpack

A Robust Video Watermarking Scheme with Squirrel Search Algorithm

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Computers, Materials & Continua 2022年第5期71卷 3069-3089页

作者： Aman Bhaskar Chirag Sharma Khalid Mohiuddin Aman Singh Osman a.nasr Mamdooh Alwetaishi Computer Science and Engineering Lovely Professional UniversityPunjab144411India Department of Management Information Systems King Khalid UniversityGuraigerAbha62529Saudi Arabia Department of Civil Engineering College of EngineeringTaif UniversityTaif21944Saudi Arabia

Advancement in multimedia technology has resulted in protection against distortion,modification,and *** implementing such protection,we have an existing technique called watermarking but obtaining desired distortion level with sufficient robustness is a challenging task for watermarking in multimedia *** the paper,we proposed a smart technique for video watermarking associating meta-heuristic algorithms along with an embedding method to gain an optimized *** main aim of the optimization algorithm is to obtain solutions with maximum robustness,and which should not exceed the set threshold of *** represent the accuracy of the proposed scheme,we employ a popular video watermarking technique(DCT domain)having frame selection and embedding method for watermarking.A squirrel search algorithm is chosen as a meta-heuristic algorithm that utilizes the stated fitness *** results indicate that quality constraint is fulfilled,and the proposed technique gives improved robustness against different attacks with several quality *** proposed technique could be practically implemented in several multimedia applications such as the films industry,medical imagery,OOT platforms,etc.

关键词： Meta-heuristic algorithm constrain optimization problem fitness fiction frame selection squirrel search algorithm

ACCURATE ATTENUATION CORRECTION FOR ALGEBRAIC RECONSTRUCTION TECHNIQUE IN SPECT

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Journal of Computational Mathematics 2010年第3期28卷 401-417页

作者： Elie nasr IMB Institute of Mathematics of Bordeaux

We present a new iterative reconstruction algorithm to improve the algebraic reconstruction technique （ART） for the Single-Photon Emission Computed Tomography. Our method is a generalization of the Kaczmarz iterative algorithm for solving linear systems of equations and introduces exact and implicit attenuation correction derived from the attenuated Radon transform operator at each step of the algorithm. The performances of the presented algorithm have been tested upon various numerical experiments in presence of both strongly non-uniform attenuation and incomplete measurements data. We also tested the ability of our algorithm to handle moderate noisy data. Simulation studies demonstrate that the proposed method has a significant improvement in the quality of reconstructed images over ART. Moreover, convergence speed was improved and stability was established, facing noisy data, once we incorporate filtration procedure in our algorithm.

关键词： Single-photon emission computed tomography Attenuated radon transform,Algebraic reconstruction technique Attenuation correction.

The contribution of mediated oxidation mechanisms in the electrolytic degradation of cyanuric acid using diamond anodes

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Journal of Environmental Sciences 2016年第7期28卷 115-123页

作者： nasr Bensalah Sondos Dbira Ahmed Bedoui Department of Chemistry and Earth Sciences College of Arts and Sciences Qatar University Department of Chemistry Faculty of Sciences of Gabes University of Gabes

In this work, the contribution of mediated oxidation mechanisms in the electrolytic degradation of cyanuric acid using boron-doped diamond（BDD） anodes was investigated in different electrolytes. A complete mineralization of cyanuric acid was obtained in Na Cl;however lower degrees of mineralization of 70% and 40% were obtained in Na2SO4 and Na Cl O4, respectively. This can be explained by the nature of the oxidants electrogenerated in each electrolyte. It is clear that the contribution of active chlorine（Cl2, HCl O, Cl O-）electrogenerated from oxidation of chlorides on BDD is much more important in the electrolytic degradation of cyanuric acid than the persulfate and hydroxyl radicals produced by electro-oxidation of sulfate and water on BDD anodes. This could be explained by the high affinity of active chlorine towards nitrogen compounds. No organic intermediates were detected during the electrolytic degradation of cyanuric acid in any the electrolytes, which can be explained by their immediate depletion by hydroxyl radicals produced on the BDD surface. Nitrates and ammonium were the final products of electrolytic degradation of cyanuric acid on BDD anodes in all electrolytes. In addition, small amounts of chloramines were formed in the chloride medium. Low current density（≤ 10 m A/cm2） and neutral medium（p H in the range 6–9） should be used for high efficiency electrolytic degradation and negligible formation of hazardous chlorate and perchlorate.

关键词： Electrolytic degradation Diamond anode Supporting electrolyte Mediated oxidation Cyanuric acid

Evaporation of a Thin Binary Liquid Film by Forced Convection into Air and Superheated Steam

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Journal of Thermal Science 2010年第4期19卷 346-356页

作者： Abdelaziz nasr Chokri Debbissi Sassi Ben nasrallah LESTE cole Nationale d'Ingenieurs de MonastirUniversite de MonastirTunisie

This paper deals with a numerical analysis of the evaporation of a thin binary liquid film by forced convection inside a channel constituted by two *** first plate is externally insulated and wetted by a thin water ethylene glycol film while the second is dry and *** first part is concerned with the effects of inlet ambiance conditions and the liquid concentration of ethylene glycol on the distribution of the velocity,temperature,concentrations profiles and the axial variation of the evaporation *** second part is focused on the inversion temperature point of the evaporation of binary liquid *** show that the inversion temperature phenomenon for the evaporation of binary liquid mixture is observed for high liquid concentration of ethylene *** present results show that in the inlet temperature range considered here,the inversion temperature does not exit for the evaporation of pure ethylene glycol.

关键词： Binary liquid film evaporation inversion temperature forced convection combined heat and mass transfer

Fenton treatment of olive oil mill wastewater—applicability of the method and parameters effects on the degradation process

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Journal of Environmental Sciences 2004年第6期16卷 942-944页

作者： Bensalah nasr Bedoui Ahmed Gadri Abdellatif Institut Supérieur des Sciences Appliquées et Technologie de Gabès Rue Amor Ibn Elkhattab Zrig 6072 Gabès TunisiaFaculté des Sciences de Gabès Cité Erriadh Zrig 6072 Gabès TunisiaEcole Nationale d'Ingénieurs de Gabès Zrig 6029 Gabès Tunisia

The low biodegradability of polyphenolic compounds typically found in olive processing indicated that biological treatment is not always successful in the treatment of olive oil mill wastewater in term of COD removal. In this study the results of investigations on the applicability of Fenton's reagent in the treatment of this effluent were discussed. The efficiency of this method was determined. 86 % of removal COD was obtained using 5 mol H 2O 2 and 0.4 mol Fe 2+ per liter of crude OMW. The main parameters that govern the complex reactive system, i.e., time, pH, [H 2O 2] and [Fe(II)] were studied.

关键词： olive oil mill wastewater Fenton's reagent organic compounds removal COD