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SI Engine Fueled with Gasoline, CNG and CNG-HHO Blend: Comparative Evaluation of Performance, Emission and Lubrication Oil Deterioration

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Journal of Thermal Science 2021年第4期30卷 1199-1211页

作者： usman muhammad HAYAT Nasir BHUTTA muhammad Mahmood Aslam Department of Mechanical Engineering University of Engineering and TechnologyLahore 54890Pakistan

Hydroxy gas (HHO) is one of the potential alternative fuels for spark ignition (SI) engine,notably due to simultaneous increase in engine performance and reduction in exhaust ***,impact of HHO gas on lubrication oil for longer periods of engine operation has not yet been *** study focuses on investigation of the effect of gasoline,CNG and CNG-HHO blend on lubrication oil deterioration along with engine performance and emissions in SI *** unit produces HHO gas at 4.72 L/min by using 6 g/L of KOH in the aqueous *** was supplied to the test engine at a pressure of 0.11 MPa using an electronically controlled solenoid *** tests were carried out at different speeds at 80%open throttle condition and various performance parameters such as brake power (BP),brake specific fuel consumption(BSFC),brake thermal efficiency (BTE),exhaust gas temperature and exhaust emissions (HC,CO_(2),CO and NO_(x))were *** addition,various lubrication oil samples were extracted over 120 h of engine running while topping for drain out volume and samples were analyzed as per ASTM ***-HHO blend exhibited better performance i.e.,15.4%increase in average BP in comparison to CNG,however,15.1%decrease was observed when compared to ***-HHO outperformed gasoline and CNG in the case of HC,CO_(2),CO and brake specific fuel consumption (31.1%decrease in comparison to gasoline).On the other hand,CNG-HHO produced higher average NO_(x) (12.9%) when compared to CNG ***,lubrication oil condition(kinematic viscosity,water contents,flash point and total base number (TBN)),wear debris (Iron (Fe),Aluminum(Al),Copper (Cu),Chromium (Cr)) and additives depletion (Zinc (Zn),Calcium (Ca)) presented a significant degradation in the case of CNG-HHO blend as compared to gasoline and *** oil analyses illustrated 19.6%,12.8%and 14.2%decrease in average viscosity,flash point and TBN for CNG-HHO blend ***,

关键词： spark ignition engine compressed natural gas hydrogen lubrication oil deterioration emission

Electromechanical Fields and Their Influence on the Internal Quantum Efficiency of GaN-Based Light-Emitting Diodes

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Acta Mechanica Solida Sinica 2018年第3期31卷 383-390页

作者： muhammad usman Kiran Saba Adnan Jahangir muhammad Kamran Nazeer muhammad Department of Engineering Sciences Ghulam Ishaq Khan Institute of Engineering Sciences and Technology Swabi 23460 Pakistan Department of Mathematics COMSATS Institute of Information Technology Wah Cantt 47040 Pakistan Department of Electrical Engineering COMSATS Institute of Information Technology Wah Cantt 47040 Pakistan

The effect ofelectromechanical fields, i.e., polarization fields, on the efficiency droop of GaN-based light-emitting diodes is presented using both experimental and numerical analyses. The role of incorporating such polarization charge density in device performance is numerically investigated and further compared with the experimental results of internal quantum efficiency of three different devices in consideration.

关键词： Optoelectronic devices Photonic bandgap materials Visible and ultraviolet sources Light-emitting devices

Structural elucidation of SARS-CoV-2 vital proteins: Computational methods reveal potential drug candidates against main protease, Nsp12 polymerase and Nsp13 helicase

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Journal of Pharmaceutical Analysis 2020年第4期10卷 320-328页

作者： muhammad usman Mirza Matheus Froeyen Department of Pharmaceutical and Pharmacological Sciences Rega Institute for Medical ResearchMedicinal ChemistryUniversity of LeuvenB-3000LeuvenBelgium

Recently emerged SARS-CoV-2 caused a major outbreak of coronavirus disease 2019(COVID-19)and instigated a widespread fear,threatening global health *** date,no licensed antiviral drugs or vaccines are available against COVID-19 although several clinical trials are under way to test possible *** this urgent situation,computational drug discovery methods provide an alternative to tiresome high-throughput screening,particularly in the hit-to-lead-optimization *** of small molecules that specifically target viral replication apparatus has indicated the highest potential towards antiviral drug *** this work,we present potential compounds that specifically target SARS-CoV-2 vital proteins,including the main protease,Nsp12 RNA polymerase and Nsp13 *** integrative virtual screening and molecular dynamics simulations approach has facilitated the identification of potential binding modes and favourable molecular interaction profile of corresponding ***,the identification of structurally important binding site residues in conserved motifs located inside the active site highlights relative importance of ligand binding based on residual energy decomposition *** the current study lacks experimental validation,the structural information obtained from this computational study has paved way for the design of targeted inhibitors to combat COVID-19 outbreak.

关键词： SARS-CoV-2 COVID-19 outbreak CoV-Mpro CoV-Nsp12 polymerase CoV-Nsp13 helicase

Joint Non-Orthogonal Multiple Access (NOMA) & Walsh-Hadamard Transform: Enhancing the Receiver Performance

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China Communications 2018年第9期15卷 160-177页

作者： muhammad Rehan usman Arsla Khan muhammad Arslan usman Soo young Shin Department of Electrical Engineering The Superior College (University Campus) Department of IT Convergence Engineering Kumoh National Institute of Technology (KIT) Department of Electrical Engineering COMSATS University Islamabad Lahore Campus

Non-orthogonal multiple access(NOMA) is a new access method to achieve high performance gains in terms of capacity and throughput, so it is currently under consideration as one of the candidates for fifth generation(5 G) technologies. NOMA utilizes power domain in order to superimpose signals of multiple users in a single transmitted signal. This creates a lot of interference at the receive side. Although the use of successive interference cancellation(SIC) technique reduces the interference, but to further improve the receiver performance, in this paper, we have proposed a joint Walsh-Hadamard transform(WHT) and NOMA approach for achieving better performance gains than the conventional NOMA. WHT is a well-known code used in communication systems and is used as an orthogonal variable spreading factor(OVSF) in communication systems. Application of WHT to NOMA results in low bit error rate(BER) and high throughput performance for both low and high channel gain users. Further, it also reduces peak to average power ratio(PAPR) of the user signal. The results are discussed in terms of comparison between the conventionalNOMA and the proposed technique, which shows that it offers high performance gains in terms of low BER at different SNR levels, reduced PAPR, high user throughput performance and better spectral efficiency.

关键词： Bit error rate (BER) non-orthogonal multiple access (NOMA) orthogonal frequency division multiplexing (OFDM) peak to average power ratio (PAPR) successive interference cancellation (SIC) throughput and Walsh-Hadamard transform (WHT).

First Principles Calculations for Corrosion in Mg-Li-Al Alloys with Focus on Corrosion Resistance: A Comprehensive Review

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Computers, Materials & Continua 2024年第11期81卷 1905-1952页

作者： muhammad Abdullah Khan muhammad usman Yuhong Zhao School of Materials Science and Engineering Collaborative Innovation Center of Ministry of Education and Shanxi Province for High-Performance Al/Mg Alloy MaterialsNorth University of ChinaTaiyuan030051China Electronics Department North University of ChinaTaiyuan030000China Beijing Advanced Innovation Center for Materials Genome Engineering University of Science and Technology BeijingBeijing100083China Institute of Materials Intelligent Technology Liaoning Academy of MaterialsShenyang110004China

This comprehensive review examines the structural,mechanical,electronic,and thermodynamic properties of Mg-Li-Al alloys,focusing on their corrosion resistance and mechanical performance *** first-principles calculations based on Density Functional Theory(DFT)and the quasi-harmonic approximation(QHA),the combined properties of the Mg-Li-Al phase are explored,revealing superior incompressibility,shear resistance,and stiffness compared to individual *** review highlights the brittleness of the alloy,supported by B/G ratios,Cauchy pressures,and Poisson’s *** structure analysis shows metallic behavior with varied covalent bonding characteristics,while Mulliken population analysis emphasizes significant electron transfer within the *** paper also studied thermodynamic properties,including Debye temperature,heat capacity,enthalpy,free energy,and entropy,which are precisely examined,highlighting the Mg-Li-Al phase sensitive to thermal conductivity and thermal performance *** density of states(PHDOS)confirms dynamic stability,while anisotropic sound velocities reveal elastic *** comprehensive review not only consolidates the current understanding of the Mg-Li-Al alloy’s properties but also proposes innovative strategies for enhancing corrosion *** these strategies is the introduction of a corrosion barrier akin to the Mg-Li-Al network,which holds promise for advancing both the applications and performance of these *** review serves as a crucial foundation for future research aimed at optimizing alloy design and processing methods.

关键词： First-principles calculations Mg-Li-Al alloys corrosion resistance thermodynamic properties mechanical properties

HybridHR-Net:Action Recognition in Video Sequences Using Optimal Deep Learning Fusion Assisted Framework

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Computers, Materials & Continua 2023年第9期76卷 3275-3295页

作者： muhammad Naeem Akbar Seemab Khan muhammad Umar Farooq Majed Alhaisoni usman Tariq muhammad usman Akram Department of Computer Engineering National University of Sciences and Technology(NUST)Islamabad46000Pakistan Department of Robotics SMME NUSTIslamabad45600Pakistan Computer Sciences Department College of Computer and Information SciencesPrincess Nourah Bint Abdulrahman UniversityRiyadh11671Saudi Arabia Management Information System Department College of Business AdministrationPrince Sattam bin Abdulaziz UniversityAl-Kharj16278Saudi Arabia

The combination of spatiotemporal videos and essential features can improve the performance of human action recognition(HAR);however,the individual type of features usually degrades the performance due to similar actions and complex *** deep convolutional neural network has improved performance in recent years for several computer vision applications due to its spatial *** article proposes a new framework called for video surveillance human action recognition dubbed *** a few selected datasets,deep transfer learning is used to pre-trained the EfficientNet-b0 deep learning *** optimization is employed for the tuning of hyperparameters of the fine-tuned deep *** of fully connected layer features,we considered the average pooling layer features and performed two feature selection techniques-an improved artificial bee colony and an entropy-based *** a serial nature technique,the features that were selected are combined into a single vector,and then the results are categorized by machine learning *** publically accessible datasets have been utilized for the experimental approach and obtained notable accuracy of 97%,98.7%,100%,99.7%,and 96.8%,***,a comparison of the proposed framework with contemporarymethods is done to demonstrate the increase in accuracy.

关键词： Action recognition entropy deep learning transfer learning artificial bee colony feature fusion

Consequences of Rényi entropy on the thermal geometries and Hawking evaporation of topological dyonic dilaton black hole

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Communications in Theoretical Physics 2024年第2期76卷 102-110页

作者： muhammad Yasir Xia Tiecheng muhammad usman Shahid Chaudhary Department of Mathematics Shanghai University and Newtouch Center for Mathematics of Shanghai UniversityShanghai200444China Department of Natural Sciences and Humanities University of Engineering and Technology LahoreNew CampusPakistan

The thermodynamics of black holes(BHs)has had a profound impact on theoretical physics,providing insight into the nature of gravity,the quantum structure of spacetime and the fundamental laws governing the *** this study,we investigate thermal geometries and Hawking evaporation of the recently proposed topological dyonic dilaton BH in anti-de Sitter(Ad S)*** consider Rényi entropy and obtain the relations for pressure,heat capacity and Gibbs free energy and observe that the Rényi parameter and dilaton field play a vital role in the phase transition and stability of the ***,we use Weinhold,Ruppeiner and Hendi Panahiyah Eslam Momennia models to evaluate the scalar curvature of the BH and find out that the divergence points of the scalar curvature coincides with the zero of specific ***,using Stefan–Boltzmann law,we determine that the BH without a dilaton field evaporates far more quickly compared to the dilaton BH in Ad S space.

关键词： topological dyonic dilaton black hole phase transition thermal geometry Hawking evaporation

Defocus Blur Segmentation Using Local Binary Patterns with Adaptive Threshold

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Computers, Materials & Continua 2022年第4期71卷 1597-1611页

作者： usman Ali muhammad Tariq Mahmood Future Convergence Engineering School of Computer Science and EngineeringKorea University of Technology and Education1600Chungjeol-roByeongcheon-myeonCheonan31253Korea

Enormousmethods have been proposed for the detection and segmentation of blur and non-blur regions of the *** to the limited available information about blur type,scenario and the level of blurriness,detection and segmentation is a challenging ***,the performance of the blur measure operator is an essential factor and needs improvement to attain *** this paper,we propose an effective blur measure based on local binary pattern(LBP)with adaptive threshold for blur *** sharpness metric developed based on LBP used a fixed threshold irrespective of the type and level of blur,that may not be suitable for images with variations in imaging conditions,blur amount and ***,the proposed measure uses an adaptive threshold for each input image based on the image and blur properties to generate improved sharpness *** adaptive threshold is computed based on the model learned through support vector machine(SVM).The performance of the proposed method is evaluated using two different datasets and is compared with five state-of-the-art *** analysis reveals that the proposed method performs significantly better qualitatively and quantitatively against all of the compared methods.

关键词： Adaptive threshold blur measure defocus blur segmentation local binary pattern support vector machine

Investigating the implications of technological innovations,financial inclusion,and renewable energy in diminishing ecological footprints levels in emerging economies

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Geoscience Frontiers 2023年第6期14卷 341-357页

作者： Najia Saqib Ilhan Ozturk muhammad usman Department of Finance College of Business AdministrationPrince Sultan UniversityRiyadhSaudi Arabia College of Business Administration University of SharjahSharjahUAE Faculty of Economics Administrative and Social SciencesNisantasi UniversityIstanbulTurkey School of Economics and Management and Center for Industrial EconomicsWuhan UniversityWuhan430072China

The correlation between technological innovation,economic growth,renewable energy,and ecological footprint carries significant policy implications for environmental ***,financial inclusion can drastically affect the technology-climate nexus across different countries and its moderating impacts have received sufficient *** do this,this study examined how technological innovation,financial inclusion,economic growth,and renewable energy affected emerging economies’ecological footprint from 1990 to ***,this study also scrutinizes the moderating role of financial inclusion with other regressors on ecological *** account for structural shifts,disguised cointegration,and numerous breaks in panel regression,this study applies advanced panel estimation methods for empirical *** estimated outcomes exhibit that the influence of technical innovation,climate technologies,and renewable energy significantly reduces the ecological footprint ***,economic growth and financial inclusion significantly increase the ecological footprint levels in the emerging ***,the integration of innovative technology and renewable energy in emerging countries mitigates the adverse effects of financial inclusion by making it easier for creative technologies and reducing ecological *** results show that emerging countries’innovative technology and renewable energy sources should be integrated with financial inclusion to enable longterm mitigation of environmental damages and sustainable *** on these estimated findings,the research recommends that emerging economies should hasten technological innovations along with stronger financial development to curtail ecological concerns without hindering the pace of sustainable economic growth.

关键词： Environmental-related technology Financial inclusion Renewable energy Ecological footprints Emerging countries