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Design and analysis of intrusion detection systems for wireless mesh networks

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Digital Communications and Networks 2022年第6期8卷 1068-1076页

作者： Fawaz s.al-Anzi P.O.Ox 5969 safat 13060 Computer Engineering DepartmentKuwait UniversityKuwait

Intrusion is any unwanted activity that can disrupt the normal functions of wired or wireless networks. Wireless mesh networking technology has been pivotal in providing an affordable means to deploy a network and allow omnipresent access to users on the Internet. A multitude of emerging public services rely on the widespread, high-speed, and inexpensive connectivity provided by such networks. The absence of a centralized network infrastructure and open shared medium makes WMNs particularly susceptible to malevolent attacks, especially in multihop networks. Hence, it is becoming increasingly important to ensure privacy, security, and resilience when designing such networks. An effective method to detect possible internal and external attack vectors is to use an intrusion detection system. although many Intrusion Detection systems (IDss) were proposed for Wireless Mesh Networks (WMNs), they can only detect intrusions in a particular layer. Because WMNs are vulnerable to multilayer security attacks, a cross-layer IDs are required to detect and respond to such attacks. In this study, we analyzed cross-layer IDs options in WMN environments. The main objective was to understand how such schemes detect security attacks at several OsI layers. The suggested IDs is verified in many scenarios, and the experimental results show its efficiency.

关键词： Wireless Mesh network Intrusi on detection Cross-layer security

Effect of bond enhancement using carbon nanotubes on flexural behavior of RC beams strengthened with externally bonded CFRP sheets

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Frontiers of structural and Civil Engineering 2022年第1期16卷 131-143页

作者： Mohammad R.IRsHIDAT Rami s.al-HUsBAN Department of Civil Engineering Jordan University of Science and TechnologyIrbid 22110Jordan

This paper studied the effect of incorporation of carbon nanotubes(CNTs)in carbon fiber reinforced polymer(CFRP)on strengthening of reinforced concrete(RC)*** RC beams were prepared,strengthened in flexure by externally bonded CFRP or CNTs-modified CFRP sheets,and tested under four-point *** experimental results showed the ability of the CNTs to delay the initiation of the cracks and to enhance the flexural capacity of the beams strengthened with CFRP.A nonlinear finite element(FE)model was built,validated,and used to study the effect of various parameters on the strengthening efficiency of CNTs-modified *** studied parameters included concrete strength,flexural reinforcement ratio,and CFRP sheet *** numerical results showed that utilization of CNTs in CFRP production improved the flexural capacity of the strengthened beams for U-shape and underside-strip *** enhancement was more pronounced in the case of U-shape than in the case of use of sheet strip covers on the underside of the *** case of using underside-strip,the longer or the wider the sheet,the higher was the flexural capacity of the *** flexural enhancement of RC beams by strengthening with CNTs-modified CFRP decreased with increasing the rebar diameter and was not affected by concrete strength.

关键词： RC beams flexural strengthening CFRP CNTs finite element

Dynamical analysis and anti-synchronization of a new 6D model with self-excited attractors

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Applied Mathematics(A Journal of Chinese Universities) 2023年第1期38卷 27-43页

作者： saad Fawzi al-Azzawi Ahmed s.al-Obeidi Department of Mathematics College of Computer Science and MathematicsUniversity of MosulMosul 41002Iraq

A novel 6D dissipative model with an unstable equilibrium point is introduced *** of the dynamic characteristics of the proposed model were explored via analyses and numerical simulations including critical points,stability,Lyapunov exponents,time phase portraits,and circuit ***,anti-synchronization phenomena were implemented on the new ***,the error dynamics is ***,four different controllers are adopted to stabilize this error relying on the nonlinear control technique with two main ways:linearization and Lyapunov stability *** comparison with previous works,the present controllers realize anti-synchronization based on another method/linearization ***,a comparison between the two ways was *** simulation results show the effectiveness and accuracy of the first analytical strategy.

关键词： 6D hyperchaotic system self-excited attractor anti-synchronization Lyapunov stability theory

Annealing Effects on the structural, Optical, and UV Photoresponse Properties of ZnO Nanostructures Prepared by RF-Magnetron sputtering at Different Deposition Temperatures

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Acta Metallurgica sinica(English Letters) 2015年第2期28卷 230-242页

作者： Husam s.al-salman M.J.Abdullah school of Physics University Sains Malaysia Department of Physics College of Science University of Basrah

Undoped ZnO nanostructures were deposited on siO2/si substrates via radio 11：equency magnetron sputtenng at different deposition temperatures （room temperature, 200, 300, and 400 ℃）. The prepared samples were annealed at 500 ℃ for 2 h under an N2 flow. The structural, surface morphological, optical, and photoresponse characteristics of ZnO nanostructures as deposited and after annealing were then investigated. The energy bandgaps of all samples after annealing （3.22-3.28 eV） decreased compared with those of the as-deposited specimens. The barrier height increased when the deposition temperature increased and reached 0.77 eV at 400 ℃ after annealing with a leakage current of 0.17 gA at a 5 V bias. The UV photodetector device which was deposited at the optimal temperature of 300 ℃, has 12.51 × 10^3% pho- tosensitivity, 2.259 pA dark current, 0.508 s response time, and 0.466 s recovery time. The dark current significantly decreased for all samples after annealing. The proposed UV photodetectors exhibit high performance, high photosensi- tivity, shorter response and recovery times, and excellent stability at lower bias voltages of 5 and 2 V.

关键词： Undoped ZnO UV photoresponse Deposition temperatures Annealing effect

Fabrication and Characterization of Undoped and Cobalt-doped ZnO Based UV Photodetector Prepared by RF-sputtering

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Journal of Materials science & Technology 2013年第12期29卷 1139-1145页

作者： Husam s.al-salman M.J.Abdullah school of Physics University Sains Malaysia Department of Physics College of ScienceUniversity of Basrah

Undoped and 1 at.% Co-doped ZnO nanostructure based UV photodetectors were successfully fabricated by RF- magnetron sputtering technique with comb like Pt electrodes. Cobalt ions were successfully incorporated into the lattice of the ZnO nanostructure without changing its wurtzite structure. It was indicated that Co-doping can effectively adjust the luminescence properties of the ZnO nanostructure. The undoped and Co-doped ZnO photodetectors were observed to have photosensitivities of 1.44 x 104 % and 8.57 x 102 % and low dark currents of 9.74 x 10-8 A and 1.18 x 10-7 A, respectively.

关键词： Characterization Co-doped ZnO UV photodetector

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Applied Mathematics and Mechanics(English Edition) 2014年第9期35卷 1155-1166页

作者： D.M.WEI s.al-AsHHAB Department of Mathematics University of New Orleans Department of Mathematics Al Imam Mohammad Ibn Saud Islamic University

The problem of the boundary layer flow of power law non-Newtonian fluids with a novel boundary condition is studied. The existence and uniqueness of the solutions are examined, which are found to depend on the curvature of the solutions for different values of the power law index n. It is established with the aid of the Picard-Lindelof theorem that the nonlinear boundary value problem has a unique solution in the global domain for all values of the power law index n but with certain conditions on the curva- ture of the solutions. This is done after a suitable transformation of the dependent and independent variables. For 0 〈 n ≤ 1, the solution has a positive curvature, while for n 〉 1, the solution has a negative or zero curvature on some part of the global domain. some solutions are presented graphically to illustrate the results and the behaviors of the solutions.

关键词： existence uniqueness power law fluid boundary layer flow non-linearboundary value problem

Extraction of cobalt(Ⅱ) from aqueous solution by N,N'-carbonyl difatty amides

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Chinese Chemical Letters 2011年第4期22卷 469-472页

作者： Emad A.Jaffar al-Mulla Khalid Waleed s.al-Janabi Department of Chemistry College of ScienceUniversity of KufaAnNajafIraq Department of Chemistry College of EducationBaghdad UniversityBaghdadIraq

The development of economic and environmentally friendly extractants to recover cobalt metal is required due to the increasing demand for this *** this study,solvent extraction of Co（Ⅱ） from aqueous solution using a mixture of N,N＇-carbonyl difatty amides（CDFAs） synthesised from palm oil as the extractant was carried *** effects of various parameters such as acid,contact time,extractant concentration,metal ion concentration and stripping agent and the separation of Co（Ⅱ） from other metal ions such as Fe（Ⅱ）,Ni（Ⅱ）,Zn（Ⅲ） and Cd（Ⅱ） were *** was found that the extraction of Co（Ⅱ） into the organic phase involved the formation of 1：1 ***（Ⅱ） was successfully separated from commonly associated metal ions such as Fe（Ⅱ）,Ni（Ⅱ）,Zn（Ⅲ） and Cd（Ⅱ）.Co（Ⅱ） stripping from the loaded organic phase was studied in aqueous *** results are useful to recover Co（Ⅱ） from aqueous solution utilising（CDFAs） as an extractant.

关键词： N N'-Carbonyl difatty amides solvent extraction Co(Ⅱ)

Preparation of composite tubular grafts for vascular repair via electrospinning

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Progress in Natural science:Materials International 2012年第2期22卷 108-114页

作者： salem s.al-Deyab Mohamed El-Newehy Petrochemical Research Chair Department of ChemistryCollege of ScienceKing Saud UniversityRiyadh 11451Saudi Arabia Department of Chemistry Faculty of ScienceTanta UniversityTanta 31527Egypt

A novel type of composite vascular graft was developed via electrospinning in the present *** and chitosan were blended to form the inner and outer ***(l-lactide-co-caprolactone)(P(LLA-CL))was selected as a material for the middle layer of composite vascular *** morphology and diameter of the composite grafts were studied by scanning Electron Microscope(sEM).The results of mechanical tests showed that the composite scaffolds provided the whole grafts with better strength and flexibility compared with blended grafts,mainly due to the fact that the middle layer was P(LLA-CL).Cell viability studies with endothelial cells suggested a prompt adhesion and proliferation duo to the fact that the outer layer was collagen and *** microscopy demonstrated that a monolayer of endothelial cells could be formed after 7 days of *** above results indicated that the composite fibrous scaffolds could be a good candidate for blood vessel repair by electrospinning method.

关键词： Electrospinning Composite Vascular graft Endothelial cell Nanofiber

Decomposition of biomass gasification tar model compounds over waste tire pyrolysis char

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Waste Disposal and sustainable Energy 2022年第2期4卷 75-89页

作者： Amal s.al-Rahbi Paul T.Williams Present address:Applied sciences Department Higher College of TechnologyUniversity of Technology and Applied SciencesMuscatSultanate of Oman school of Chemical and Process Engineering University of LeedsLeedsLS29JTUK

Gasification of biomass produces a syngas containing trace amounts of viscous hydrocarbon tar,which causes serious problems in downstream pipelines,valves and processing *** study focuses on the use of tire-derived pyrolysis char for tar conversion using biomass tar model compounds representative of *** catalytic decomposition of tar model compounds,including methylnaphthalene,furfural,phenol,and toluene,over tire char was investigated using a fixed bed reactor at a bed temperature of 700℃and 60 min time on *** influence of temperature,reaction time,porous texture,and acidity of the tire char was investigated with the use of methylnaphthalene as the tar model *** tar model compounds were found to have higher conversion than those containing a single or multi-aromatic *** reactivity of tar compounds followed the order of furfural>phenol>toluene>*** conversion of the model compounds in the presence of the tire char was much higher than tar thermal *** production increased dramatically with the introduction of tire *** H_(2)potential for the studied tar model compounds was found to be in the range of 40%–50%.The activity of tire char for naphthalene removal was compared with two commercial activated carbons possessing a very well-developed porous *** results suggest that the influence of Brunauer-Emmett-Teller surface area of the carbon on tar cracking is negligible compared with the mineral content in the carbon samples.

关键词： Biomass Gasification syngas Tar Tire Char