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LDH-based nanomaterials for photocatalytic applications:A comprehensive review on the role of bi/trivalent cations, anions,morphology, defect engineering, memory effect, and heterojunction formation

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Journal of Energy Chemistry 2023年第9期84卷 242-276页

作者： Azmat Ali khan Muhammad Tahir nazish khan Baluchistan University of Information Technology Engineering and Management Sciences(BUITEMS)P.O.Box 87100QuettaPakistan Chemical and Petroleum Engineering Department UAE UniversityP.O.Box 15551Al AinUnited Arab Emirates The University of Agriculture Swat P.O.Box 19040Pakistan

Using sunlight to drive chemical reactions via photocatalysis is paramount for a sustainable *** several photocatalysts,employing layered double hydrides(LDH) for photocatalytic application is most straightforward and desirable owing to their distinctive two-dimensional(2D) lamellar structure and optical *** article reviews the advancements in bimetallic/trimetallic LDHs and various strategies to achieve high efficiency toward an outstanding performing ***,the tuning of LDH components that control the electro nic and structural properties is *** tu ning obtained through the adoption,combination,and incorporation of different cations and anions is also *** progress of modification methods,such as the adoption of different morphologies,delamination,and defect engineering towards enhanced photocatalytic activities,is discussed in the *** band engineering,structural characteristics,and redox tuning are further deliberated to maximize solar energy harvesting for different photocatalytic ***,the progress obtained in forming hierarchical heterostructures through hybridization with other semiconductors or conducting materials is systematically disclosed to get maximum photocatalytic ***,the structural changes during the in-situ synthesis of LDH and the stability of LDH-based photocatalysts are *** review also summarizes the improvements in LDH properties obtained through modification tactics and discusses the prospects for future energy and environmental applications.

关键词： LDH Properties Potential photocatalyst Photocatalytic application Photocatalytic properties Improvement strategies

Stability analysis of a discrete biological model

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International Journal of Biomathematics 2016年第2期9卷 65-83页

作者： A. Q. khan M. n. Qureshi Department of MathematicsUniversity of Azad Jammu and Kashmir Muzaffarabad 13100 Pakistan

In this paper, we investigate the equilibrium point, local and global behavior of the unique positive equilibrium point, and rate of convergence of positive solutions of following discrete biological model： Xn＋1=Xne^ln（α）（1-Yn）,Yn＋1=（γδ-1）Yn（1＋1/γδ-1-Yn/Xn）, where parameters α,γ,δ and the initial conditions Xo, ]Io are positive real numbers. Some numerical examples are given to verify theoretical results.

关键词： Discrete biological model local stability global character rate of convergence.

Systematic study of Ce^(3+) on the structural and magnetic properties of Cu nanosized ferrites for potential applications

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Journal of Rare Earths 2018年第2期36卷 156-164页

作者： Majid niaz Akhtar A.B.Sulong M.n.Akhtar Muhammad Azhar khan Department of Physics Muhammad Nawaz Sharif University of Engineering and Technology (MNSUET) Department of Mechanical and Materials Engineering Faculty of Engineering and Built Environment Universiti Kebangsaan Malaysia (UKM) Institute of Pure and Applied Biology Department of ZoologyBahaudin Zakariya University Department of Physics The Islamia University of Bahawalpur

Ce^（3＋） substituted Cu-spinel nanoferrites CuCe_xFe_（2-x）O_4（x=0.00, 0.02, 0.04, 0.06, 0.08 and 0.10） were synthesized via sol-gel self-combustion hybrid route. Single phase spinel ferrite of Cu nanoferrites were examined using X-ray diffraction（XRD） analysis whereas the multiphase structure was observed as Ce contents increased from x=0.06. Field emission scanning electron microscopy（FESEM）, Thermogravimetric and differential thermal analysis（TGA and DTA） and Fourier transform infrared spectroscopy（FTIR） were used to find out the morphology phase and metal stretching vibrations of Ce^（3＋） substituted nanocrystalline ferrites. The crystallite size was increased and found in the range of 25-91 nm. The agglomerations in Cu ferrite samples increase as the Ce^（3＋） concentration increases. The magnetic properties such as remanence, saturation magnetization, coercivity, Bohr magneton and magnetocrystalline anisotropy constant（K） were determined using M-H loops recorded from a vibrating sample magnetometer（VSM）. Saturation magnetization, remanence and coercivity are increased as the Ce^（3＋）contents increase in Cu nanocrystalline samples. Moreover, law of approach to saturation（LoA） was used to calculate the maximum value of saturation for Ce-doped Cu nanoferrites. The soft magnetic behaviour of the Cu nanoferrite is observed as compared to the samples substituted with the increased Ce contents in Cu nanocrystalline ferrite. Bohr magneton and magnetocrystalline anisotropy are found to increase with the substitution of rare earth Ce^（3＋） contents in Cu spinel nanocrystalline ferrite. Cedoped Cu nanocrystalline ferrites with excellent properties may be suitable for potential applications in sensing, security, switching, core, multilayer chip inductor, biomedical and microwave absorption applications.

关键词： Ce-doped Cu nanocrystalline ferrites X-ray diffraction(XRD) Scanning electron microscopy(SEM) Transmission electron microscopy(TEM) Fourier transform infrared(FTIR) Vibrating sample magnetometer(VSM)

Deep learning approach to detect seizure using reconstructed phase space images

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The Journal of Biomedical Research 2020年第3期34卷 240-250页

作者： n.Ilakiyaselvan A.nayeemulla khan A.Shahina School of Computer Science and Engineering Vellore Institute of TechnologyChennaiTamilnadu 600127India Department of Information Technology SSN College of EngineeringKalavakkamTamilnadu 603110India

Epilepsy is a chronic neurological disorder that affects the function of the brain in people of all *** manifests in the electroencephalogram(EEG) signal which records the electrical activity of the *** image processing,signal processing,and machine-learning based techniques are employed to analyze epilepsy,using spatial and temporal *** nervous system that generates the EEG signal is considered nonlinear and the EEG signals exhibit chaotic *** order to capture these nonlinear dynamics,we use reconstructed phase space(RPS) representation of the *** studies have primarily addressed seizure detection as a binary classification(normal ***) problem and rarely as a ternary class(normal *** ***)*** employ transfer learning on a pre-trained deep neural network model and retrain it using RPS images of the EEG *** classification accuracy of the model for the binary classes is(98.5±1.5)% and(95±2)% for the ternary *** performance of the convolution neural network(Cnn) model is better than the other existing statistical approach for all performance indicators such as accuracy,sensitivity,and *** result of the proposed approach shows the prospect of employing RPS images with Cnn for predicting epileptic seizures.

关键词： epilepsy reconstructed phase space convolution neural network reconstructed phase space image Alexnet seizure

Phase analysis of AlFe2B2 by synchrotron X-ray diffraction,magnetic and M?ssbauer studies

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Progress in natural Science:Materials International 2017年第2期27卷 251-256页

作者： Tahir Ali M.n.khan E.Ahmed Asad Ali Physics Division Pakistan Institute of Nuclear Science and technology Department of Physics Abdul Wali khan University PInSAT Preston University

The structural and magnetic properties of essentially phase pure AlFe2B2prepared by arc melting were compared with a sample containing impurities. Analysis was carried out by means of synchrotron X-ray diffraction, magnetic measurements and M?ssbauer spectroscopy. The analysis of synchrotron X-ray diffraction data confirmed the orthorhombic structure of space group Cmmm for AlFe2B2with Al13Fe4as main impurity phase. The magnetic measurements revealed an unsaturated ferromagnetic state in AlFe2B2with a transition temperature（Tc） of 286 K. Isothermal magnetization measurment at 5 K gave a saturation magnetization of 0.7 μB per Fe atom while Arrott plots establish the second order nature of ferromagnetic transition. The thermal evolution of M?ssbauer spectra confirmed the ferromagnetic nature of this material revealing an hyperfine field of 73 kOe and an isomer shift of 0.46 mm/s at 100 K. The M?ssbauer spectra of a phase pure sample was compared with the one containing impurity phases. It is suggested that the low temperature paramagnetic contribution in M?ssbauer spectra of phase pure material may have its origin in some intrinsic phenomena arising from defects or inhomogeneities in crystal structure.

关键词： AlFe2B2 Synchrotron X-ray diffraction Ferromagnetism Mossbauer effect spectroscopy

Implication of 14-3-3ζ-BDnF pathway in long-lasting memory enhancement and the rescue from memory deficits

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neural Regeneration Research 2022年第12期17卷 2685-2686页

作者： Mariam Masmudi-Martín Irene navarro-Lobato Zafar U.khan Brain Metastasis Group National Cancer Research Centre(CNIO)MadridSpain Donders Institute for Brain Cognition and Behaviour Radboud UniversityNijmegenThe Netherlands Laboratory of neurobiology CIMESUniversity of MalagaMalagaSpain Department of Medicine Faculty of MedicineUniversity of MalagaMalagaSpain CIBERnED Institute of Health Carlos ⅢMadridSpain

Intact memory function is critical for carrying out daily life activities,such as managing finances,remembering to take medications,driving in familiar environments,remembering a grandchild’s birthday,and learning to use a new ***,memory deficits not only accompany normal aging but are also comorbid with many psychiatric,neurological,and neurodegenerative *** disability,autism,attention deficit disorder,learning disability,schizophrenia,and depression all have memory deficit components,as do Alzheimer’s disease,Parkinson’s disease,Huntington’s disease,and other neurodegenerative diseases(khan et al.,2014).Therefore,a large proportion of the human population is affected by this brain disorder.

关键词： Huntington remember finance

Synthesis of nanostructured Mg-ni Alloy and Its Hydrogen Storage Properties

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Journal of Materials Science & Technology 2012年第5期28卷 401-406页

作者： n.A. niaz I. Ahmad Waheed S. khan S. Tajammul Hussain Department of Physics COMSATS Institute of Information Technology Islamabad Pakistan Research Centre of Materials Science School of Materials Science and Engineering Beijing Institute of Technology national Centre for Physics Qaid-a-Azam University Islamabad Pakistan

nanostructured Mg–ni alloy with the particle size in the range of 40–50 nm was synthesized by the thermal decomposition of bipyridyl complexes of Mg and ni metals at 773 K for 24 h under dry argon gas ambient. The as-prepared nano-alloy was characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM） and transmission electron microscopy （TEM） for compositional and structural analysis. The alloy exhibited superior hydrogen absorption and desorption behavior with 3.2 wt% absorption within 1 min at 573 K and about 3 wt% desorption within 5–10 min at 573 K. This favorable behavior of Mg–ni compound for the hydrogen storage is due to the specific nanostructure of the material. The low activation energy values and favorable thermodynamics indicate that the prepared Mg–ni alloy is an attracting material for hydrogen storage applications.

关键词： Mg-ni alloy Hydrogen storage Pressure-composition-temperature (P-C-T) measurements Transmission electron microscopy

Development of Wheel-less Snake Robot with Two Distinct Gaits and Gait Transition Capability

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International Journal of Automation and computing 2013年第6期10卷 534-544页

作者： M.H.A.Majid M.R.khan S.n.Sidek Department of Mechatronics Engineering International Islamic University Malaysia

Snake robots are mostly designed based on single mode locomotion. However, single mode gait most likely could not work effectively when the robot is subject to an unstructured working environment with different measures of terrain complexity. As a solution, mixed mode locomotion is proposed in this paper by synchronizing two types of gaits known as serpentine and wriggler gaits used for non-constricted and narrow space environments, respectively, but for straight line locomotion only. A gait transition algorithm is developed to efficiently change the gait from one to another. This study includes the investigation on kinematics analysis followed by dynamics analysis while considering related structural constraints for both gaits. The approach utilizes the speed of the serpentine gait for open area locomotion and exploits the narrow space access capability of the wriggler gait. Hence, it can increase motion flexibility in view of the fact that the robot is able to change its mode of locomotion according to the working environment.

关键词： Bio-inspired robots robotics robot dynamics robot kinematics robotic mechanical systems.

Acupuncture enhances brain function in patients with mild cognitive impairment: evidence from a functional-near infrared spectroscopy study

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neural Regeneration Research 2022年第8期17卷 1850-1856页

作者： M.n.Afzal khan Usman Ghafoor Ho-Ryong Yoo Keum-Shik Hong School of Mechanical Engineering Pusan National UniversityBusanKorea Department of neurology Disorders Dunsan HospitalDaejeon UniversityDaejeonKorea

Mild cognitive impairment(MCI)is a precursor to Alzheimer’s *** is imperative to develop a proper treatment for this neurological disease in the aging *** observational study investigated the effects of acupuncture therapy on MCI *** healthy individuals and eleven MCI patients were recruited for this ***-and deoxy-hemoglobin signals in the prefrontal cortex during working-memory tasks were monitored using functional near-infrared *** acupuncture treatment,working-memory experiments were conducted for healthy control(HC)and MCI groups(MCI-0),followed by 24 sessions of acupuncture for the MCI *** acupuncture sessions were initially carried out for 6 weeks(two sessions per week),after which experiments were performed again on the MCI group(MCI-1).This was followed by another set of acupuncture sessions that also lasted for 6 weeks,after which the experiments were repeated on the MCI group(MCI-2).Statistical analyses of the signals and classifications based on activation maps as well as temporal features were *** highest classification accuracies obtained using binary connectivity maps were 85.7%HC ***-0,69.5%HC ***-1,and 61.69%HC *** classification accuracies using the temporal features mean from 5 seconds to 28 seconds and maximum(i.e,max(5:28 seconds))values were 60.6%HC ***-0,56.9%HC ***-1,and 56.4%HC *** results reveal that there was a change in the temporal characteristics of the hemodynamic response of MCI patients due to *** was reflected by a reduction in the classification accuracy after the therapy,indicating that the patients’brain responses improved and became comparable to those of healthy subjects.A similar trend was reflected in the classification using the image *** results indicate that acupuncture can be used for the treatment of MCI patients.

关键词： acupuncture Alzheimer’s disease cognition convolutional neural network functional connectivity functional-near infrared spectroscopy hemodynamic response linear discriminant analysis mild cognitive impairment