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Chinese Journal of Chemical Engineering 2015年第5期23卷 812-815页

作者： Md khalid Anwer Faiyaz Shakeel Department of Pharmaceutics College of Pharmacy Salman Bin Abdulaziz University Center of Excellence in Biotechnology Research King Saud University Department of Pharmaceutics College of Pharmacy King Saud University

The aim of present study was to measure and correlate the solubility of poorly water-soluble flavonoid diosmin in water, ethanol, isopropyl alcohol （IPA）, polyethylene glycol-400 （PEG-400） and β-cyclodextrin （β-CD） aqueous solution （0.02 mol·L^-1 ）. The solubility of diosmio was measured using the shake flask method from （298.15 to 333.15） K at atmospheric pressure. The experimental solubilities of diosmin were regressed by the modified Apelblat model with a relative deviation in the range of 0.048% to 5.940%. The correlation coefficients were observed in the range of 0.9957 to 0.9995. The solubility of diosmin was found to be increased with temperature in all sample matrices investigated. The mole fraction solubility of diosmin was found to be higher in 5-CD aqueous solution and PEG-400 as compared to water, ethanol and IPA. Based on solubility data of present study, diosmin was considered as practically insoluble in water, insoluble in ethanol ＆ IPA and soluble in PEG- 400 and β-CD aqueous solution.

关键词： Apelblat model Cyclodextrin Diosmin Solubility Thermodynamics

Glassy behaviour of random field Ising spins on Bethe lattice in external magnetic field

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Chinese Physics B 2011年第6期20卷 416-425页

作者： khalid Bannora Galal Ismail Wafaa Hassan Mathematics Department Faculty of Science Zagazig University Mathematics and Physics Department Faculty of Engineering Port Said Branch of Suez Canal University

The thermodynamics and the phase diagram of random field Ising model （RFIM） on Bethe lattice are studied by using a replica trick. This lattice is placed in an external magnetic field （B）. A Gaussian distribution of random field （hi） with zero mean and variance （hi2 = H2RF is considered. The free-energy （F）, the magnetization （M） and the order parameter （q） are investigated for several values of coordination number （z）. The phase diagram shows several interesting behaviours and presents tricritical point at critical temperature Tc = J/k and when HRF = 0 for finite z. The free-energy （F） values increase as T increases for different intensities of random field （HRE） and finite z. The internal energy （U） has a similar behaviour to that obtained from the Monte Carlo simulations. The ground state of magnetization decreases as the intensity of random field HRF increases, The ferromagnetic （FM） paramagnetic （PM） phase boundary is clearly observed only when z →∞. While FM PM-spin glass （SG） phase boundaries are present for finite z. The magnetic susceptibility （X） shows a sharp cusp at Tc in a small random field for finite z and rounded different peaks on increasing HRF.

关键词： random field replica trick coordination number order parameter susceptibility and phase diagram

Glassy phase and thermodynamics for random field Ising model on spherical lattice in magnetic field

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Chinese Physics B 2010年第10期19卷 525-533页

Phase diagram and thermodynamic parameters of the random field Ising model （RFIM） on spherical lattice are studied by using mean field theory. This lattice is placed in an external magnetic field （B）. The random field （hi） is assumed to be Gaussian distributed with zero mean and a variance （hi2） = HRF2. The free energy （F）, the magnetization （M） and the order parameter （q） are calculated. The ferromagnetic （FM） spin-glass （SG） phase transition is clearly observed. The critical temperature （Tc） is computed under a critical intensity of random field HRF = V/2/πJ. The phase transition from FM to paramagnetic （PM） occurs at TC = J/k in the absence of magnetic field. The critical temperature decreases as HRF increases in the phase boundary of FM-to-SG. The magnetic susceptibility （X） shows a sharp cusp at TC and the specific heat （C） has a singularity in small random field. The internal energy （U） has a similar behaviour to that obtained from the Monte Carlo simulation.

关键词： random field mean field theory magnetization specific heat and phase diagram

Mutational analysis of hepatitis E virus ORF1 'Y-domain' : Effects on RNA replication and virion infectivity

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World Journal of Gastroenterology 2017年第4期23卷 590-602页

作者： Mohammad khalid Parvez Department of Pharmacognosy King Saud University College of PharmacyRiyadh 11451Saudi Arabia

AIMTo investigate the role of non-structural open reading frame 1 “Y-domain” sequences in the hepatitis E virus (HEV) life *** of human HEV Y-domain (amino acid sequences 216-442) and closely-related viruses were analyzed in silico. Site-directed mutagenesis of the Y-domain (HEV SAR55) was carried out and studied in the replicon-baculovirus-hepatoma cell model. In vitro transcribed mRNA (pSK-GFP) constructs were transfected into S10-3 cells and viral RNA replicating GFP-positive cells were scored by flow cytometry. Mutant virions’ infectivity was assayed on naïve HepG2/C3A *** silico analysis identified a potential palmitoylation-site (C336C337) and an α-helix segment (L410Y411S412W413L414F415E416) in the HEV Y-domain. Molecular characterization of C336A, C337A and W413A mutants of the three universally conserved residues showed non-viability. Further, of the 10 consecutive saturation mutants covering the entire Y-domain nucleotide sequences (nts 650-1339), three constructs (nts 788-994) severely affected virus replication. This revealed the indispensability of the internal sequences but not of the up- or downstream sequences at the transcriptional level. Interestingly, the three mutated residues corresponded to the downstream codons that tolerated saturation mutation, indicating their post-translational functional/structural essentiality. In addition, RNA secondary structure prediction revealed formation of stable hairpins (nts 788-994) where saturation mutation drastically inhibited virion *** is the first demonstration of the critical role of Y-domain sequences in HEV life cycle, which may involve gene regulation and/or membrane binding in intracellular replication complexes.

关键词： Hepatitis E virus Open reading frame 1 Y-domain Palmitoylation α -helix

Distributed cooperative control of autonomous multi-agent UAV systems using smooth control

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Journal of Systems Engineering and Electronics 2020年第6期31卷 1297-1307页

作者： BELKACEM Kada MUNAWAR khalid MUHAMMAD Shafique Shaikh Department of Aerospace Engineering King Abdulaziz UniversityJeddah 21589Saudi Arabia Department of Electrical and Computer Engineering King Abdulaziz UniversityJeddah 21589Saudi Arabia

This paper addresses the cooperative control problem of multiple unmanned aerial vehicles(multi-UAV)***,a new distributed consensus algorithm for second-order nonlinear multi-agent systems(MAS)is formulated under the leader-following *** algorithm provides smooth input signals to the agents’control channels,which avoids the chattering effect generated by the conventional sliding mode-based control ***,a new formation control scheme is developed by integrating smooth distributed consensus control protocols into the geometric pattern model to achieve three-dimensional formation *** Lyapunov theory is used to prove the stability and convergence of both distributed consensus and formation *** effectiveness of the proposed algorithms is demonstrated through simulation results.

关键词： cooperative control distributed consensus three-dimensional formation control multiple-UAV system

Pre-existing frailty in the elderly and long-term mortality following percutaneous coronary intervention

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Journal of Geriatric Cardiology 2023年第11期20卷 832-836页

作者： Muhammad Ali Tariq Zoha khalid Minhail khalid Malik Department of Medicine Dow University of Health SciencesKarachiPakistan

With global improvements in life expectancy,the proportion of the world’s population over 60 years of age has grown by 3%annually,and it is expected that by 2050,this population segment will nearly double.[1]This demographic transition carries profound impact on public health,with far-reaching economic implications for healthcare delivery,social and inhome care.[2]One of the most troublesome health manifestations of an ageing population is frailty,a multidimensional syndrome of accumulated ageand disease-related deficits that results in reduced resilience and increased vulnerability to stressors.

关键词： demographic annually population

Detecting Driver Distraction Using Deep-Learning Approach

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Computers, Materials & Continua 2021年第7期68卷 689-704页

作者： khalid A.AlShalfan Mohammed Zakariah College of Computer and Information Sciences Al-Imam Muhammad Ibn Saud Islamic UniversityRiyadh11564Saudi Arabia College of Computer and Information Science King Saud UniversityRiyadh11442Saudi Arabia

Currently,distracted driving is among the most important causes of traffic ***,intelligent vehicle driving systems have become increasingly ***,interest in driver-assistance systems that detect driver actions and help them drive safely has *** these studies,although some distinct data types,such as the physical conditions of the driver,audio and visual features,and vehicle information,are used,the primary data source is images of the driver that include the face,arms,and hands taken with a camera inside the *** this study,an architecture based on a convolution neural network(CNN)is proposed to classify and detect driver *** efficient CNN with high accuracy is implemented,and to implement intense convolutional networks for large-scale image recognition,a new architecture was proposed based on the available Visual Geometry Group(VGG-16)*** proposed architecture was evaluated using the StateFarm dataset for driver-distraction *** dataset is publicly available on Kaggle and is frequently used for this type of *** proposed architecture achieved 96.95%accuracy.

关键词： Deep learning driver-distraction detection convolution neural networks VGG-16

Exchange Coupling and Magnetic Behavior of SmCo_(5-x)Sn_x Alloys

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Journal of Materials Science & Technology 2011年第3期27卷 218-222页

作者： Hamid Zaigham F.Ahmad khalid Faculty of Materials Science and Engineering GIK Institute of Engineering Sciences and Technology

Exchange coupling and magnetic properties of SmCo5 alloys containing different amounts of Sn were investigated in sintered magnets. X-ray diffraction analysis revealed the formation of Sm2Co17 and Sm2Co7 phases in SmCo5 matrix. Exchange coupling mechanism was evaluated by switching field distribution, dcdemagnetization and magnetization curves as function of reverse applied field. Energy product of 59.2 kJ/m3 （7.4 MGOe）, remanent magnetization to maximum magnetization ratio of 0.97 and remanence coercivity to intrinsic coercivity ratio of 1.75 were achieved for 0.2 at.% Sn.

关键词： Nanocomposite magnet Nanocrystalline phases Sintering Exchange interactions

Effect of Filler Composition on the Brazing of Alumina to Copper Using Ultrasonic Wave

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Journal of Materials Science & Technology 2003年第Z1期19卷 176-178页

作者： khalid M. HAFEZ Masaaki NAKA Joining & Welding Research Institute Osaka University Ibaraki Osaka 567-0047 Japan Joining & Welding Research Institute Osaka University Ibaraki Osaka 567-0047 Japan

An ultrasonic wave was applied during brazing of alumina to Cu. First alumina was metallized by applying ultrasonicwave in braze bath. Then the metallized alumina was brazed with Cu using the same filler alloy. The filler used wereZn-Al alloys and Zn-Sn Alloys. The weight percent of Al in filler was ranging between 0, 5%, 10%, *** weight percent of tin in filler was ranging between 0, 30%, 60% and 91%, respectively. The joining mechanismwas investigated by measuring the joining strength, hardness and analyzing the microstructure at interface of thejoint. The shear strength and microstructure of the joint strongly depend on the filler composition. The effect ofultrasound was derived primarily from acoustic cavitations, impact and friction of the filler against alumina *** improved the wetting between alumina and the filler, and reflected to improve the joint strength. Anotherultrasonic advantage as to reduce of the joining temperature, that reduced the thermal stress in the braze joint.

关键词： Alumina, Copper, Ultrasonic waves, Fracture stress, Microstructure, Brazing

Quantum Stackelberg Duopoly in a Noninertial Frame

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Chinese Physics Letters 2011年第7期28卷 5-8页

作者： Salman Khan M.khalid Khan Department of Physics Quaid-i-Azam UniversityIslamabad 45320Pakistan

We study the influence of the Unruh effect on quantum Stackelberg *** is shown that the acceleration of a noninertial frame strongly affects the payoffs of the *** validation of the subgame perfect Nash equilibrium is limited to a particular range of acceleration of the noninertial *** benefit of the initial state entanglement in the quantum form of the duopoly in the inertial frame is adversely affected by the *** duopoly can become a follower advantage only in a small region of the acceleration.

关键词： acceleration Stackelberg Quantum