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Deformation and failure in nanomaterials via a data driven modelling approach

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Theoretical & Applied mechanics Letters 2020年第4期10卷 249-252页

作者： m.amir Siddiq School of Engineering University of AberdeenAB243UEAberdeenUK

A data driven computational model that accounts for more than two material states has been presented in this work. Presented model can account for multiple state variables, such as stresses,strains, strain rates and failure stress, as compared to previously reported models with two *** is used to perform deformation and failure simulations of carbon nanotubes and carbon nanotube/epoxy nanocomposites. The model capability of capturing the strain rate dependent deformation and failure has been demonstrated through predictions against uniaxial test data taken from literature. The predicted results show a good agreement between data set taken from literature and simulations.

关键词： Data driven computational mechanics Nanomaterials Carbon nanotubes Nanocomposites

Eighteen-Element Antenna for metal-Rimmed Smartphone Sub-6 GHz LTE42 Band Applications

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Computers, materials & Continua 2022年第11期73卷 3181-3198页

作者： Saqer S.Alja’Afreh mallak H.Alshamaileh Eqab Almajali Jawad Yousaf amir Altaf Electrical Engineering Department Mutah UniversityAl-karak61710Jordan Electrical Engineering Department University of SharjahSharjahUAE Department of Electrical Computer&Biomedical EngineeringAbu Dhabi UniversityAbu DhabiUAE Department of Electrical and Computer Engineering Sungkyunkwan UniversityKorea

Due to the limited space and large mutual coupling levels,the design of sub-6 GHz massive multi-Input multi-Output(m-mImO)smartphone antenna system attracts antennas’designers and engineers ***,this paper presents 18-element m-mImO antenna system that covers the long-term evolution 42(LTE42)frequency band(3.4–3.6 GHz)for the fifth generation(5G)applications in metallic frame *** proposed array system is etched on the long sides of a metal rim of the mobile chassis symmetrically,which is electrically connected to the system ground plane with zero ground clearance.A low-profile frame of height 7 mm(λ/12.3)is symmetrically placed below&above the ground system *** two frame parts(above/below the ground level)are utilized separately for the implantation of the antenna elements to achieve good space exploitation and perfect pattern diversity between *** feeds are used to further increase the level of the isolation where each antenna element above the ground level is fed by a 50-ohm microstrip line,and each antenna element below the ground level is fed by a 50-ohm coplanar waveguide(CPW).The proposed antenna structure is a capacitive coupled-fed open-slot antenna with a small footprint area of 12×3.5 mm2(λ/7.2×λ/24.5,whereλrepresents the free space wavelength at 3.5 GHz).A small coupling L-shaped strip provides a capacitive coupling for the proposed 5G antenna *** establish the contribution of the proposed 18-element m-mImO,the prototype of the proposed system was manufactured and successfully *** measured and simulated results are shown to be in good *** proves that the proposed antenna provides coverage for the LTE42 band(3.4–3.6 GHz)with acceptable isolation and ***,the performance of the proposed m-mImO were further verified via channel capacity calculation and the envelope correlation coefficient(ECC)*** on that,the proposed m-mImO is shown to provide a desira

关键词： metal-rim smartphone antennas massive mImO 5G band

A Quality-aware Incremental LmS Algorithm for Distributed Adaptive Estimation

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International Journal of Automation and computing 2014年第6期11卷 676-682页

作者： Wael m.Bazzi amir Rastegarnia Azam Khalili Electrical and Computer Engineering Department American University in Dubai Dubai United Arab Emirates Department of Electrical Engineering Malayer University Malayer 65719-95863 Iran

In this paper, we consider the problem of unknown parameter estimation using a set of nodes that are deployed over an area. The recently proposed distributed adaptive estimation algorithms(also known as adaptive networks) are appealing solutions to the mentioned problem when the statistical information of the underlying process is not available or it varies over time. In this paper, our goal is to develop a new incremental least-mean square(LmS) adaptive network that considers the quality of measurements collected by the nodes. Thus, we use an adaptive combination strategy which assigns each node a step size according to its quality of measurement. The adaptive combination strategy improves the robustness of the proposed algorithm to the spatial variations of signal-to-noise ratio(SNR). The performance of our algorithm is more remarkable in inhomogeneous environments when there are some nodes with low SNRs in the network. The simulation results indicate the efficiency of the proposed algorithm.

关键词： Adaptive networks distributed estimation least mean-square (LmS) incremental cooperation quality aware

Recent Development in Defects Engineered Photocatalysts:An Overview of the Experimental and Theoretical Strategies

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Energy & Environmental materials 2022年第1期5卷 68-114页

作者： Zaiba Zafar Shasha Yi Jinpeng Li Chuanqi Li Yongfa Zhu amir Zada Weijing Yao Zhongyi Liu Xinzheng Yue College of Chemistry School of Material Science and EngineeringZhengzhou UniversityZhengzhou 450001China Department of Chemistry Tsinghua UniversityBeijing 100084China Department of Chemistry Abdul Wali Khan University MardanMardan 23200Pakistan

Recently,defect architectured photocatalysis is proved to be the most versatile choice for high solar to chemical energy conversion *** engineering strategies are of great demand to effectively tune the electronic microstructure and surface morphologies of semiconductors to boost charge carrier concentration and extend light harvesting *** review provides a comprehensive insight to various kinds of defects along with their synthesis procedures and controlling mechanism to uplift photocatalytic *** addition,the contribution made by defects and material optimization techniques toward electronic band structure of the photocatalyst,the optimal concentration of defects,the key adsorption processes,charge distribution,and transfer dynamics have been explained in ***,to clarify the relationship between photocatalytic activity and defect states in real,a comprehensive outlook to the versatile photocatalytic applications has been presented to highlight current challenges and future *** engineering therefore stands as the next step toward advancement in the design and configuration of modern photocatalysts for high efficiency photocatalysis.

关键词： defect engineering electronic structure photocatalysis vacancies

An Investigation of ~4He+^(12)C and ~4He+^(16)O Reactions Using the Cluster model

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Communications in Theoretical Physics 2012年第7期58卷 135-140页

作者： A.H.Al-Ghamdi Awad A.Ibraheem m.El-Azab farid Physics Department Faculty of ScienceKing Abdul Aziz UniversityJeddahSaudi Arabia Physics Department Al-Azhar UniversityAssiut BranchAssiut 71524Egypt Physics Department King Khalid UniversityAbhaSaudia Arabia Physics Department Assiut UniversityAssiut 71516Egypt

The α-target semimicroscopic single folding potentials have been derived by folding a composite (repul-sive and attractive) effective α-α interaction with the α-cluster distribution density in the target nuclei. The obtained potentials are considered as the real part of the nuclear optical model potentials, while the imaginary parts are phe-nomenologicaly expressed using the Woods-Saxon form. Nine sets of measured experimental data of the 4He+12C and 4 He+16O elastic rainbow scattering over the energy range 80-240 meV are analyzed using the obtained potentials. The data are successfully reproduced using the extracted potentials. The resulted reaction cross sections are also investigated and compared with the available corresponding data.

关键词：光学模型势反应截面比值群集相互作用分布密度苯丙氨酸实验数据

Assaying the allelopathic effects of Eucalyptus camaldulensis in a nursery bed incorporated with leaf litter

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Journal of Forestry Research 2018年第3期29卷 592-598页

作者： Romel Ahmed mohammad Shafioul Alam farid Uddin Ahmed m.K.Hossain Department of Forestry and Environmental Science Shahjalal University of Science and TechnologySylhet 3114Bangladesh ministry of Public Administration TeknafCoxsbazarDhaka 4761Bangladesh Arannayk Foundation House 21 Western RoadDOHSBananiDhaka 1206Bangladesh Institute of Forestry and Environmental Science University of ChittagongChittagong 4331Bangladesh

Allelopathic effects of Eucalyptus camaldulensis Dehnh. were confirmed in Petri dish and pot experiments in our previous studies. However, the degree to which such effects under controlled experiments exist in more complex ecological settings remains to be tested. Thus, the present study was carried out by incorporating different proportions of ground litter of E. camaldulensis in soil. The growth of three agricultural crops: falen(Vigna unguiculata(L.) Walp.), chickpea(Cicer arietinum L.), and arhor(Cajanus cajan(L.) millsp.), and two tree species, kala koroi(Albizia procera(Roxb.) Benth.) and ipil ipil(Leucaena leucocephala(Lam.) de Wit) were tested. There were inhibitory effects of leaf litter on germination, shoot and root growth, leaf number, and collar diameter as well as a reduction of nodulation by legume crops(25–80%reduction). The extent of the effects was dependent on the proportion of leaf litter, the species and the type of traits. In contrast to shoot growth, the effect on root growth was more severe. No effect on germination was found with the agriculture crops while the two tree species showed reduced germination. The effect was greater in the presence of higher proportions of leaf litter mixed in soil while in some cases lower proportions stimulated growth. Not all species were suppressed; A. procera, C. cajan, V. unguiculata showed compatible growth while C. arietinum and *** were found incompatible. This study provides evidence that E. camaldulensis has allelopathic potential under field conditions and a careful selection of associated crops in agroforestry systems is highly recommended.

关键词： Allelopathy Eucalyptus camaldulensis Inhibitory effects Germination Growth Nodulation

Some Criteria for the Cohen-macaulay Property and Local Cohomology

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Acta mathematica Sinica,English Series 2009年第6期25卷 917-922页

作者： amir mAFI Department of mathematics University of Kurdistan Institute for Studies in Theoretical Physics and mathematics

Let a be an ideal of a commutative Noetherian ring R and m be a finitely generated R-module of dimension d. We characterize Cohen-macaulay rings in term of a special homological dimension. Lastly, we prove that if R is a complete local ring, then the matlis dual of top local cohomology module Ha^d（m） is a Cohen-macaulay R-module provided that the R-module m satisfies some conditions.

关键词： Cohen-macaulay Gorenstein flat module local cohomology module

Temporal Correlation-Based Spatial Filtering of Rician Noise for Functional mRIs

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Chinese Physics Letters 2012年第1期29卷 287-290页

作者： amir.A.Khaliq I.m.Qureshi Jawad.A.Shah Department of Electronic Engineering International Islamic UniversityIslamabadPakistan Air University ISSSIslamabadPakistan

A novel correlation-based filter is presented for de-noising functional magnetic resonance imaging (fmRI) *** correlation-based exponential weights are defined for spatial smoothing of the data,with bias reduction using estimated noise *** proposed scheme is tested on simulated and real fmRI ***,the results are compared with conventional *** method is found to be effectively suppressing the Rician noise in fmRI data,while improving the SNR.

关键词： weights smoothing Spatial

mechanical and thermodynamical stability of BiVO4 polymorphs using first-principles study

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Chinese Physics B 2017年第3期26卷 395-403页

作者： A K m farid UI Islam md Nurul Huda Liton H m Tariqul Islam md Al Helal md Kamruzzaman Department of Computer Science and Engineering Begum Rokeya University Rangpur Rangpur-5400 Bangladesh Department of Physics Begum Rokeya University Rangpur Rangpur-5400 Bangladesh Department of Chemistry Begum Rokeya University Rangpur Rangpur-5400 Bangladesh Department of Physics and materials Science and Center of Super-Diamond and Advanced Films (COSDAF) City University of Hong Kong Hong Kong SAR China

First principles calculations of structural, electronic, mechanical, and thermodynamic properties of different poly- morphs of BiVO4 are performed using Bender-type plane/wave ultrasoft pseudopotentials within the generalized gradient approximation （GGA） in the flame of density functional theory （DFT）. The calculated structural and electronic properties are consistent with the previous theoretical and experimental results. The electronic structures reveal that m-BiVO4, op- BiVO4, and st-BiVO4 have indirect band gaps, on the other hand, zt-BiVO4 has a direct band gap. From the DOS and mulliken＇s charge analysis, it is observed that only m-BiVO4 has 6s2 Bi lone pair. Bond population analysis indicates that st-BiVO4 shows a more ionic nature and a similar result is obtained from the elastic properties. From the elastic prop- erties, it is observed that st-BiVO4 is more mechanically stable than the others, st-BiVO4 is more ductile and useful for high electro-optical and electro-mechanical coupling devices. Our calculated thermodynamic properties confirm the similar characteristics found from electronic and elastic properties, m-BiVO4 is useful as photocatalysts, solid state electrolyte, and electrode and other polymorphs are applicable in electronic device fabrications.

关键词： BiVO4 crystal structure lone pair mechanical stability