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Beamforming techniques for massive MIMO systems in 5G:overview,classification,and trends for future research

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Frontiers of Information Technology & Electronic Engineering 2017年第6期18卷 753-772页

作者： Ehab ALI Mahamod ismail Rosdiadee NORDIN Nor Fadzilah ABDULAH Department of Electrical Electronic and System EngineeringUniversiti Kebangsaan Malaysia(UKM)Bangi 43600Malaysia

Massive multiple-input multiple-output(MIMO) systems combined with beamforming antenna array technologies are expected to play a key role in next-generation wireless communication systems(5G), which will be deployed in 2020 and beyond. The main objective of this review paper is to discuss the state-of-the-art research on the most favourable types of beamforming techniques that can be deployed in massive MIMO systems and to clarify the importance of beamforming techniques in massive MIMO systems for eliminating and resolving the many technical hitches that massive MIMO system implementation faces. Classifications of optimal beamforming techniques that are used in wireless communication systems are reviewed in detail to determine which techniques are more suitable for deployment in massive MIMO systems to improve system throughput and reduce intra-and inter-cell interference. To overcome the limitations in the literature, we have suggested an optimal beamforming technique that can provide the highest performance in massive MIMO systems, satisfying the requirements of next-generation wireless communication systems.

关键词： Beamforming classifications Massive MIMO Hybrid beamforming Millimetre-wave beamforming

Ground state energy of He isoelectronic sequence treated variationally via Hylleraas-like wavefunction

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Chinese Physics B 2009年第6期18卷 2238-2243页

作者： Serpil Sakiroglu Kadir Akgngr ismail Skmen Physics Department Dokuz Eyll University

In this study, the energy for the ground state of helium and a few helium-like ions （Z=1-6） is computed variationally by using a Hylleraas-like wavefunction. A four-parameters wavefunction, satisfying boundary conditions for coalescence points, is combined with a Hylleraas-like basis set which explicitly incorporates r12 interelectronic distance. The main contribution of this work is the introduction of modified correlation terms leading to the definition of integral transforms which provide the calculation of expectation value of energy to be done analytically over single-particle coordinates instead of Hylleraas coordinates.

关键词： He isoelectronic sequence Hylleraas basis set electronic correlation variational method

SARS-CoV-2 spike behavior in situ:a Cryo-EM images for a better understanding of the COVID-19 pandemic

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Signal Transduction and Targeted Therapy 2020年第1期5卷 326-327页

作者： Alaa M.ismail Abdo A.Elfiky Biophysics Department Faculty of SciencesCairo UniversityGizaEgypt

Most recently in Nature Journal,Ke et *** investigate the SARS-CoV-2 spike in situ by using cryo-electron microscopy(Cryo-EM)to reveal its different conformations,orientations,and distribution over the virion particles.

关键词： particles thoroughly behavior

Mesoporous WO_3-graphene photocatalyst for photocatalytic degradation of Methylene Blue dye under visible light illumination

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Journal of Environmental Sciences 2018年第4期30卷 328-337页

作者： Adel A.ismail M.Faisal Adel Al-Haddad Wastewater Treatment and Reclamation Technologies (WTRT) Water Research Center Kuwait Institute for Scientific Research Advanced Materials and Nano-Research Centre Najran University

Advanced oxidation technologies are a friendly environmental approach for the remediation of industrial wastewaters. Here, one pot synthesis of mesoporous WO3 and WO3-graphene oxide（GO） nanocomposites has been performed through the sol–gel method. Then, platinum（Pt） nanoparticles were deposited onto the WO3 and WO3-GO nanocomposite through photochemical reduction to produce mesoporous Pt/WO3 and Pt/WO3-GO nanocomposites. X-ray diffraction（XRD） findings exhibit a formation of monoclinic and triclinic WO3 phases. Transmission Electron Microscope（TEM） images of Pt/WO3-GO nanocomposites exhibited that WO3 nanoparticles are obviously agglomerated and the particle sizes of Pt and WO3 are ~ 10 nm and 20–50 nm, respectively. The mesoporous Pt/WO3 and Pt/WO3-GO nanocomposites were assessed for photocatalytic degradation of Methylene Blue（MB） as a probe molecule under visible light *** findings showed that mesoporous Pt/WO3, WO3-GO and Pt/WO3-GO nanocomposites exhibited much higher photocatalytic efficiencies than the pure WO3. The photodegradation rates by mesoporous Pt/WO3-GO nanocomposites are 3, 2 and 1.15 times greater than those by mesoporous WO3, WO3-GO, and Pt/WO3, respectively. The key factors of the enhanced photocatalytic performance of Pt/WO3-GO nanocomposites could be explained by the highly freedom electron transfer through the synergetic effect between WO3 and GO sheets, in addition to the Pt nanoparticles that act as active sites for O2 reduction, which suppresses the electron hole pair recombination in the Pt/WO3-GO nanocomposites.

关键词： Mesoporous Pt/WO3 nanocomposites Graphene oxide Methylene Blue photodegradation Visible light

Controlled multilevel switching and artificial synapse characteristics in transparent HfAlO-alloy based memristor with embedded TaN nanoparticles

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Journal of Materials Science & Technology 2021年第36期95卷 203-212页

作者： Chandreswar Mahata Hassan Algadi Muhammad ismail Daewoong Kwon Sungjun Kim Division of Electronics and Electrical Engineering Dongguk UniversitySeoul 04620Republic of Korea Department of Electrical Engineering Faculty of EngineeringNajran UniversityP.O.Box 1988Najran 11001Saudi Arabia Department of Electrical Engineering Inha UniversityIncheonRepublic of Korea

Atomic layer deposition technique has been used to prepare tantalum nitride nanoparticles(TaN-NPs)and sandwiched between Al-doped HfO;layers to achieve ITO/HfAlO/TaN-NP/HfAlO/ITO RRAM *** electron microscopy along with energy dispersive spectroscopy confirms the presence of TaN-NPs.X-ray photoelectron spectroscopy suggests that part of Ta N converted to tantalum oxynitride(TaO_(x)N_(y))which plays an important role in stable cycle-to-cycle resistive *** trapping and oxygen vacancy creation were found to be modified after the inclusion of Ta N-NPs inside RRAM ***,HfAlO/TaO_(x)N_(y)interface due to the presence TaN-NPs improves the device-to-device switching reliability by reducing the probability of random rupture/formation of conductive filaments(CFs).DC endurance of more than 10^(3)cycles and memory data retention up to 10^(4)s was achieved with an insignificant variation of different resistance *** conductance was attained by controlling RESET voltage with stable data retention in multiple *** volatile threshold switching was monitored after controlling the CF forming at 200 nA current compliance with high selectivity of~10^(3).Synaptic learning behavior has been demonstrated by spike-rate-dependent plasticity(SRDP).Reliable potentiation and depression processes were observed after the application of suitable negative and positive pulses which shows the capability of the TaN–NPs based RRAM device for transparent synaptic devices.

关键词： RRAM ALD TaN-nanoparticles Threshold switching Spike-rate-dependent plasticity Multilevel conductance Synaptic properties

Spatial Distribution and Anthropogenic Assessment of Heavy Metals in the Surface Sediments of Klang River

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湿地科学 2011年第1期9卷 8-18页

作者： Abolfazl Naji Ahmad ismail Department of Biology Faculty of science University Putra Malaysia

The study was conducted to quantify the concentration and distribution of metals (Cd, Zn, Ni, Cu, Pb, and Fe) in the surface sediments and to assess the status of metal contaminations in the Klang River, Malaysia. The concentrations of metals (μg∕g, Fe%, dry weight) were as follows: 0.57-2.19 μg∕g Cd; 31.89-272.33 μg∕g Zn; 5.96-24.47 μg∕g Ni; 10.57-52.87 μg∕g Cu; 24.23-64.11 μg∕g Pb and 1.56%-3.03% Fe. Sequential extraction technique (SET) showed that mean anthropogenic portions of metals were in the order of Zn (60.22%), Cu (56.01%), Cd (45.63%), Ni (42.08%), Pb (33.22%) and Fe (10.26%). The highest concentrations of metals ( p<0.05) were found in the stations located close to industrial parks and highly populated areas. The results of the present study showed that the effectiveness of total organic carbon (TOC) contents in controlling the distribution and enrichment of metals was a more important factor compared to grain size. The study also indicated that the control of metals pollution from direct influx of domestic wastes and insufficiently treated industrial wastes in the Klang River was an important and desirable way to minimize the detrimental effects of metals.

关键词： heavy metals spatial distribution surface sediment anthropogenic assessment

Rising incidence of acute hepatitis A among adults and clinical characteristics in a tertiary care center of Pakistan

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World Journal of Virology 2025年第1期14卷 73-82页

作者： Yumna Shahid Amna Subhan Butt Iqra Jamali Faisal Wasim ismail Division of Gastroenterology Department of MedicineAga Khan University HospitalKarachi 74800Pakistan Department of Medicine Aga Khan University HospitalKarachi 74800Pakistan

BACKGROUND For decades,hepatitis A virus(HAV)has been a leading cause of acute hepatitis among children and was less prevalent among ***,recently a paradigm shift has been observed in the epidemiology of HAV,as evident by cases of acute hepatitis due to HAV among *** To estimate frequency of HAV in acute viral hepatitis and compare characteristics in HAV and hepatitis E virus(HEV)*** This was a trend analysis conducted at Aga Khan University Hospital Karachi(Sindh,Pakistan)from February 2024 to May *** aged 18 years and older diagnosed with acute viral hepatitis attributed to hepatotropic viruses in 2024 were *** compare the trend patients admitted with acute hepatitis during 2019-2023 were also *** regarding clinical and laboratory parameters were *** yearly trend of acute hepatitis due to HAV and HEV was analyzed,and comparative analysis was done between HAV and HEV cases among *** A total of 396 patients were found to have acute hepatitis during our study *** was diagnosed in 234 patients(59%)while 157 patients(39.6%)were found to have acute HEV ***,acute hepatitis B virus infection was identified in 3 patients(0.7%),whereas acute hepatitis C virus infection was found in 2(0.5%)cases of acute *** trends showed increasing occurrence of HAV infection among adults over last 5 *** patients with acute HAV were younger than patients with HEV(28 years±8 years vs 30 years±8 years;P<0.01).Higher levels of total bilirubin were seen in HEV infection,while higher levels of alanine transaminase were seen in HAV ***,a higher proportion of acute liver failure(ALF),coagulopathy,and mortality were observed in *** An increase in acute hepatitis A cases among adults shows less severity than hepatitis E,highlighting the need for better sanitation,hygiene,and adult hepatitis A vaccination programs.

关键词： Acute hepatitis Hepatitis A virus Hepatitis E virus Acute liver failure Hepatotropic virus Vaccination

Issues and challenges in diabetic neuropathy management:A narrative review

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World Journal of Diabetes 2023年第6期14卷 741-757页

作者： Che Aishah Nazariah ismail Department of Physiology School of Medical SciencesUniversity Sains Malaysia Health CampusKubang Kerian 16150KelantanMalaysia

Diabetic neuropathy(DN)is a devastating disorder with an increasing prevalence *** epidemic can pose a critical burden on individuals and communities,subsequently affecting the productivity and economic output of a *** more people living a sedentary lifestyle,the incidence of DN is escalating *** researchers have relentlessly worked on ways to combat this devastating *** efforts have given rise to a number of commercially available therapies that can alleviate the symptoms of ***,most of these therapies are only partially *** still,some are associated with unfavorable side *** narrative review aims to highlight current issues and challenges in the management of DN,especially from the perspective of molecular mechanisms that lead to its progression,with the hope of providing future direction in the management of *** improve the approaches to diabetic management,the suggested resolutions in the literature are also discussed in this *** review will provide an in-depth understanding of the causative mechanisms of DN,apart from the insights to improve the quality and strategic approaches to DN management.

关键词： Diabetic neuropathy Pathophysiology Diabetic management Diabetic medication

Demonstration of synaptic and resistive switching characteristics in W/TiO_(2)/HfO_(2)/TaN memristor crossbar array for bioinspired neuromorphic computing

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Journal of Materials Science & Technology 2022年第1期96卷 94-102页

作者： Muhammad ismail Umesh Chand Chandreswar Mahata Jamel Nebhen Sungjun Kim Division of Electronics and Electrical Engineering Dongguk UniversitySeoul 04620South Korea Department of Electrical and Computer Engineering National University SingaporeSingapore 117583Singapore College of Computer Engineering and Sciences Prince Sattam bin Abdulaziz UniversityAl-Kharj 11942Saudi Arabia

In this study,resistive random-access memory(RRAM)-based crossbar arrays with a memristor W/TiO_(2)/HfO_(2)/TaN structure were fabricated through atomic layer deposition(ALD)to investigate synaptic plasticity and resistive switching(RS)characteristics for bioinspired neuromorphic computing.X-ray photoelectron spectroscopy(XPS)was employed to explore oxygen vacancy concentrations in bilayer TiO_(2)/HfO_(2)*** fitting for O1s peaks confirmed that the HfO_(2)layer contained a larger number of oxygen vacancies than the TiO_(2)*** addition,HfO_(2)had lower Gibbs free energy(ΔG°=-1010.8 kJ/mol)than the TiO_(2)layer(ΔG°=-924.0 kJ/mol),resulting in more oxygen vacancies in the HfO_(2)*** results andΔG°magnitudes confirmed that formation/disruption of oxygen-based conductive filaments took place in the TiO_(2)*** W/TiO_(2)/HfO_(2)/TaN memristive device exhibited excellent and repeatable RS characteristics,including superb 10^(3) dc switching cycles,outstanding 107 pulse endurance,and high-thermal stability(10^(4) s at 125℃)important for digital computing ***,some essential biological synaptic characteristics such as potentiation-depression plasticity,paired-pulse facilitation(PPF),and spike-timing-dependent plasticity(STDP,asymmetric Hebbian and asymmetric anti-Hebbian)were successfully mimicked herein using the crossbar-array memristive *** on experimental results,a migration and diffusion of oxygen vacancy based physical model is proposed to describe the synaptic plasticity and RS *** study demonstrates that the proposed W/TiO_(2)/HfO_(2)/TaN memristor crossbar-array has a significant potential for applications in non-volatile memory(NVM)and bioinspired neuromorphic systems.

关键词： Resistive switching Crossbar-array memristive device Synaptic plasticity TiO_(2)/HfO_(2)film Oxygen vacancy