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Optical Investigation of Sm^(3+) Doped Zinc-Lead-Phosphate Glass

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Chinese Physics Letters 2012年第8期29卷 233-236页

作者： Raja J.Amjad M.R.Sahar S.K.Ghoshal M.R.Dousti S.Riaz b.a.tahir Advanced Optical Material Research Group Faculty of ScienceUniversiti Teknologi Malaysia81310 SkudaiJohorMalaysia Centre for Solid State Physics University of the PunjabQACLahore-54590Pakistan

Samarium doped lead-zinc-phosphate glasses having composition(60-x)P_(2)O_(5)-20PbO-20ZnO-xSm_(2)O_(3) where x=0,0.5,1.0,3.0mol%were prepared by using the melt quenching *** Archimedes method was used to measure their densities,which are used to calculate the molar *** values of densities lie in the range 3.698–4.090 gm/cm^(3) whereas those of molar volume lie in the range of 37.24–40.00 cm^(-3).UV-vis-NIR absorption spectroscopy in the wavelength range 200–2000 nm was carried *** spectra consist of seven absorption peaks corresponding to the transitions from the 6H5/2 ground state to various excited energy *** energy band gap measured from the optical absorbance is found to be in the range of 3.88–4.43 eV and 3.68–4.33 eV for direct and indirect transitions,*** addition,the photoluminescence spectrum shows four prominent emission bands centered at 560,597,642 and 700 nm corresponding to the 4G5/2–6HJ(J=5/2,7/2,9/2,11/2)transitions respectively and the intensity of all the bands are enhanced as the concentration of Sm3+ions increases.

关键词： technique transitions bands

CT为基础的肺叶通气与3He-MR成像通气测量的比较

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国际医学放射学杂志 2016年第2期 197-197页

作者： b.a.tahir C.V.Holsbeke R.H.Ireland A.J.Swift F.C.Horn H.Mar-shall 韩宁 Academic Units of Academic Radiology University of SheffieldC FloorRoyal Hallamshire Hospital INSIGNEO Institute of In-silico Medicine

摘要目的比较吸气相及呼气相肺叶通气CT数据与超极化3He-MR成像上直接测量的肺通气数据,利用与3HeMR成像相同屏气时段所获得的1H-MR成像来配准多模态影像。材料与方法本研究经国家研究伦理委员会批准,并获得病人书面同意。30例哮喘病人... 详细信息

摘要目的比较吸气相及呼气相肺叶通气CT数据与超极化3He-MR成像上直接测量的肺通气数据,利用与3HeMR成像相同屏气时段所获得的1H-MR成像来配准多模态影像。材料与方法本研究经国家研究伦理委员会批准,并获得病人书面同意。30例哮喘病人在总肺容量及功能余气量的状态下屏气行CT检查。在功能余气量加上1 L的肺容量状态下相同屏气时段获得3He-MR和1H-MR影像。通过主

关键词：肺叶 MR 通气量 CT 左肺上叶

Constructing S-scheme 2D/0D g-C_(3)N_(4)/TiO_(2) NPs/MPs heterojunction with 2D-Ti3AlC2 MAX cocatalyst for photocatalytic CO_(2) reduction to CO/CH_(4) in fixed-bed and monolith photoreactors

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Journal of Materials Science & Technology 2022年第11期106卷 195-210页

作者： Muhammad tahir beenish tahir Department of Chemical Engineering School of Chemical and Energy EngineeringUniversiti Teknologi Malaysia81310UTM Johor BahruMalaysia Chemical and Petroleum Engineering Department UAE UniversityP.O.Box 15551Al AinUnited Arab Emirates

Exfoliated 2D MAX Ti_(3) AlC_(2) conductive cocatalyst anchored with g-C_(3)N_(4)/TiO_(2) to construct 2D/0D/2D het-erojunction has been explored for enhanced CO_(2) photoreduction in a fixed-bed and monolith *** TiO_(2) particle sizes(NPs and MPs)were systematically investigated to determine effective metal-support interaction with faster charge carrier separation among the composite *** TiO_(2) NPs were anchored with 2D Ti_(3) AlC_(2) MAX structure,10.44 folds higher CH_(4) production was observed com-pared to anchoring TiO_(2) *** CH_(4) yield rate of 2103.5μmol g^(−1) h^(−1) achieved at selectivity 96.59%using ternary g-C_(3)N_(4)/TiO_(2)/Ti_(3) AlC_(2)2D/0D/2D composite which is 2.73 and 7.45 folds higher than using binary g-C_(3)N_(4)/Ti_(3) AlC_(2) MAX and TiO_(2) NPs/Ti_(3)AlC_(2) samples,respectively.A step-scheme(S-scheme)photocatalytic mechanism operates in this composite,suppressed the recombination of useful electron and holes and provides higher reduction potential for efficient CO_(2) conversion to CO and CH_(4).More im-portantly,when light intensity was increased by 5 folds,CH_(4) production rate was increased by 3.59 folds under visible *** performance of composite catalyst was further investigated in a fixed-bed and monolith photoreactor and found monolithic support increased CO production by 2.64 folds,whereas,53.99 times lower CH_(4) production was *** lower photocatalytic activity in a monolith photore-actor was due to lower visible light penetration into the ***,2D MAX Ti_(3) AlC_(2) composite catalyst can be constructed for selective photocatalytic CO_(2) methanation under visible light in a fixed-bed photoreactor.

关键词： Photocatalytic CO_(2)methanation Exfoliated 2D MAX Ti_(3)AlC_(2) g-C_(3)N_(4)/TiO_(2) Fixed-bed reactor,Monolith photoreactor Solar energy

Emergency Prioritized and Congestion Handling Protocol for Medical Internet of Things

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Computers, Materials & Continua 2021年第1期66卷 733-749页

作者： Sabeen tahir Sheikh tahir bakhsh Rayed AlGhamdi Information Technology Department Faculty of Computing and Information TechnologyKing Abdulaziz UniversityJeddah21589Saudi Arabia

Medical Internet of Things(MIoTs)is a collection of small and energyefficient wireless sensor devices that monitor the patient’s *** healthcare networks transmit continuous data monitoring for the patients to survive them *** are many improvements in MIoTs,but still,there are critical issues that might affect the Quality of Service(QoS)of a *** handling is one of the critical factors that directly affect the QoS of the *** congestion in MIoT can cause more energy consumption,delay,and important data *** a patient has an emergency,then the life-critical signals must transmit with minimum *** emergencies,the MIoTs have to monitor the patients continuously and transmit data(e.g.,ECG,bP,heart rate,etc.)with minimum ***,there is an efficient technique required that can transmit emergency data of high-risk patients to the medical staff on time with maximum *** main objective of this research is to monitor and transmit the patient’s real-time data efficiently and to prioritize the emergency *** this paper,Emergency Prioritized and Congestion Handling Protocol for Medical IoTs(EPCP_MIoT)is proposed that efficiently monitors the patients and overcome the congestion by enabling different monitoring *** the emergency data transmissions are prioritized and transmit at SIFS *** proposed technique is implemented and compared with the previous technique,the comparison results show that the proposed technique outperforms the previous techniques in terms of network throughput,end to end delay,energy consumption,and packet loss ratio.

关键词： Congestion control MIoTs emergency prioritization energy-efficient

Characterization of ion irradiated silicon surfaces ablated by laser-induced breakdown spectroscopy

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Chinese Physics b 2018年第8期27卷 505-510页

作者： T Iqbal M Abrar M b tahir M Seemab A Majid S Rafique Department of Physics Faculty of Sciences University of Gujrat Hafiz Hayat Campus Department of Physics Hazara University Mansehra Department of Physics University of Engineering and Technology (UET)Lahore Pakistan

Low energy metallic ions, generated by a Q-switched Nd：YAG laser （1064-nm wavelength, 10-mJ energy, 9-nm 12-ns-pulse width, 1011 W/cm2 intensity） irradiated on a silicon substrate to modify various properties, such as electrical, morphological, and structural modifications. Thomson parabola technique is used to calculate the energy of these metallic ions whereas the electrical conductivity is calculated with the help of Four-point probe. Interestingly circular tracks forming chain like damage trails are produced via these energetic ions which are carefully examined by optical microscopy. It is observed that excitation, ionization, and cascade collisions are responsible for surface modifications of irradiated samples. Four-point probe analysis revealed that the electrical conductivity of substrate has reduced with increasing trend of atomic number of irradiated metallic ions （A1, Ti, Cu, and Au）. The x-ray diffraction analysis elucidated the crystallographic changes leading to reduction of grain size of N-type silicon substrate, which is also associated with the metallic ions used. The decreasing trend of conductivity and grain size is due to thermal stresses, scattering effect, structural imperfections, and non-uniform conduction of energy absorbed by substrate atoms after the ion irradiation.

关键词： ablation Thomson parabola technique four-point probe

Liquid Phase bonding of 316L Stainless Steel to AZ31 Magnesium Alloy

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Journal of Materials Science & Technology 2011年第1期27卷 22-28页

作者： Waled Elthalabawy tahir Khan Department of Mechanical and Manufacturing Engineering University of Calgary

The excellent corrosion resistance,formability and strength make stainless steels versatile for diverse ***,its high specific strength and good crashworthiness make it suitable for transportation and aerospace *** the other hand,the need to reduce the weight of vehicle and aerospace components has created renewed interest in the use of magnesium *** to their differences in physical and metallurgical properties,bonding of the 316L steel and AZ31 magnesium alloy using conventional fusion welding methods encountered many ***,the use of liquid phase forming interlayers is required to overcome the differences in their properties,eliminates the need for a high bonding pressure to achieve intimate contact between the bonded *** Cu and Ni interlayers successively formed a eutectic phase with *** formation of intermetallics and Mg diffusion caused the eutectic phase to isothermally solidify with increasing bonding *** formation of ternary intermetallic phases（λ1 and b2） impaired the bond shear strength particularly at the end of the isothermal solidification stage where no eutectic phase was ***,the joints showed a higher shear strength value of 57 MPa when bonding with Cu interlayer at 530℃ for 30 min compared to 32 MPa when Ni interlayer was used at 510℃ for 20 min.

关键词： Magnesium alloy Stainless steel Eutectic bonding Microstructure Shear strength

Proper Conformal Killing Vectors in Kantowski-Sachs Metric

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Communications in Theoretical Physics 2018年第4期69卷 393-398页

作者： tahir Hussain Muhammad Farhan Department of Mathematics University of Peshawar Khyber Pakhtunkhwa Pakista

This paper deals with the existence of proper conformal Killing vectors(CKVs) in Kantowski-Sachs *** to some integrability conditions, the general form of vector filed generating CKVs and the conformal factor is presented. The integrability conditions are solved generally as well as in some particular cases to show that the nonconformally flat Kantowski-Sachs metric admits two proper CKVs, while it admits a 15-dimensional Lie algebra of CKVs in the case when it becomes conformally flat. The inheriting conformal Killing vectors(ICKVs), which map fluid lines conformally, are also investigated.

关键词： conformal killing vectors killing vectors Kantowski-Sachs metric

Performance improvement of complementary feeders using static transfer switch system

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第2期10卷 189-200页

作者： tahir MAHMOOD Mohammad Ahmad CHOUDHRY Department of Electrical Engineering University of Engineering and Technology

The performance of complementary feeders, running in parallel, can be significantly improved by installing static transfer switches （STSs） at critical locations. We develop the STS control logic, which transfers the critical load from the preferred feeder to the alternate feeder when a voltage sag or a fault occurs on the preferred feeder. A forced commutation technique is proposed and implemented to turn off the preferred feeders＇ thyristor, thus avoiding cross current to flow and minimizing the transfer time. Simulation results show that the forced commutation technique is more effective as compared to the recently proposed time delay technique for STS operation. Two different feeders, namely New Exchange, the preferred feeder, and Sector 1-10/2, the alternate feeder of Islamabad Electric Supply COmpany （IESCO）, Pakistan, have been selected for case studies. The software PSCAD/EMTDC professional package has been used for simulation.

关键词： Complementary feeder Cross current Static transfer switch (STS) Sensitive load Voltage sag PSCAD/EMTDC

Neuroinflammation revisited through the microglial lens

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Neural Regeneration Research 2025年第7期20卷 1989-1990页

作者： Renato Socodato João b.Relvas Institute of Research and Innovation in Health(i3S)and Institute for Molecular and Cell biology(IbMC) University of PortoPortoPortugal Department of biomedicine Faculty of Medicine of the University of Porto(FMUP)PortoPortugal

Neuroimmunology is emerging as a pivotal field,shedding light on the intricate dialogues between the central nervous system(CNS)and the immune *** exploration is particularly significant in understanding microglia,the CNS’s innate immune cells,beyond the conventional conflation of“neuroinflammation”and“microglial activation.”This conflation has clouded the true complexity of these processes,potentially stalling scientific progress and the development of new *** challenge the long-standing perspectives that have oversimplified these interactions,advocating for a deeper exploration of the dynamic relationship between neuroinflammation and microglial *** dissecting specific molecular pathways,we aim to illuminate their elaborate roles in neuroinflammatory responses,especially in the context of Alzheimer’s disease(AD).Here,neuroinflammation is not merely a passive observer or a direct antagonist but a complex agent in the disease’s *** article calls for a significant paradigm shift towards an integrative,multi-omics approach to *** such a comprehensive framework is crucial for advancing our understanding of neuroinflammatory conditions and paving the way for targeted therapeutic strategies for brain diseases.

关键词： inflammation simplified activation