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Robust Half-Metallicity and Magnetic Properties of Cubic Perovskite CaFeO_(3)

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Chinese Physics Letters 2013年第4期30卷 192-196页

作者： Zahid Ali Iftikhar Ahmad Banaras khan imad khan Materials Modeling Center Department of PhysicsUniversity of MalakandChakdaraDir(L)Pakistan Department of Physics Hazara UniversityMansehraPakistan

Theoretical studies of the cubic perovskite CaFeO3 are performed using the full potential linearized augmented plane-wave method with GGA+*** calculated structural parameters are consistent with the experimental *** tolerance factor reveals the cubic phase of the *** spin polarized electronic band structures and densities of states as well as the integer value of the magnetic moment of the unit cell(4μB)demonstrate that CaFeO_(3)is half *** in CaFeO_(3)is due to Fe^(+4)–O^(2)–Fe^(+4)superexchange *** robust properties of the compound show that with their compression up to a certain critical lattice constant,known as the robust transition lattice constant,an abrupt change in the electronic and magnetic properties occurs;the compounds lose their integer magnetic moment and become metallic.

关键词： integer cubic magnetic

First principle studies of structural, elastic, electronic and optical properties of Zn-chalcogenides under pressure

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Journal of Semiconductors 2014年第7期35卷 1-9页

作者： Muhammad Bilal M.Shafiq Iftikhar Ahmad imad khan Department of Physics University of MalakandChakdaraPakistan

Structural, elastic, electronic and optical properties ofzinc-chalcogenides （viz. ZnX, X = S, Se and Te） are studied in zinc-blende structure under hydrostatic pressure using the full-potential linearized augmented plane wave method. Generalized gradient approximation is used for exchange correlation potentials. Pressure-dependent lattice constants and bulk moduli are obtained using the optimization method. Young＇s modulus, Poisson＇s ratio, internal strain parameter and anisotropy are also calculated. The higher values of Young＇s modulus in comparison to the bulk modulus show that these materials are hard to break. Poisson＇s ratio is computed for the first time for these materials to the best of our knowledge and its values show higher ionic contribution in these materials. Modified Becke and Johnson （mBJ） method is used to study band gaps, density of states, dielectric function and refractive index. Electronic study shows direct band gaps convert to indirect band gaps with increasing pressure in the case of ZnS and ZnTe. We compared our results with other theoretical and experimental results. Our results are far better than other theoretical results because mBJ is the best technique to treat Ⅱ-Ⅵ semiconductors.

关键词： semiconductors elastic properties electronic band structures

Structural and optoelectronic properties of CsLnZnTe_(3)(Ln=La,Pr,Nd and Sm)

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Journal of Rare Earths 2023年第3期41卷 388-396,I0003页

作者： imad khan Ihsan Ullah Izaz Ul Haq Akbar Ali A.Dahshan Zahid Ali Iftikhar Ahmad Center for Computational Materials Science Department of PhysicsUniversity of MalakandChakdaraPakistan Department of Physics Faculty of ScienceKing Khalid UniversityP.O.Box 9004AbhaSaudi Arabia Department of Physics Faculty of SciencePort Said UniversityPort SaidEgypt Gomal University Dera Ismail KhanPakistan

Zinc telluride is a versatile wide band gap semiconductor used in many *** it has certain limitations like large dimensions and large band *** alkali metal to its bulk lattice(3D)can reduce its dimensions and lanthanide can produce a red shift in the energy gap by converting it into quaternary *** alkali and lanthanide incorporated quaternary zinc tellurides CsLnZnTe_(3)(Ln=La,Pr,Nd and Sm)form layered crystal structure in which_(∞)^(2)[LnZnTe_(3)]-layers are separated by Cs+*** famous lanthanide contraction is experimental both from lattice constants and bond *** calculated band gaps are 2.26,2.28,2.12,2.05 eV for CsLaZnTe_(3),CsPrZnTe_(3),CsNdZnTe_(3) and CsSmZnTe_(3),*** compounds show direct band gap *** energy band gaps of these compounds have not been evaluated yet both experimentally and *** loss functions,refractive index and dielectric functions were also calculated to explore the potential applications of CsLnZnTe_(3) in optoelectronic devices.

关键词： Chalcogenides Optical materials Electronic structure Dimensions reduction Ab-initio calculations Rare earths

Optoelectronic and elastic properties of metal halides double perovskites Cs_(2)InBiX_(6)(X = F, Cl, Br, I)

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Chinese Optics Letters 2021年第3期19卷 17-26页

作者： Muhammad Saeed Izaz Ul Haq Shafiq Ur Rehman Akbar Ali Wajid Ali Shah Zahid Ali Qasim khan imad khan State Key Laboratory of Nuclear Resources and Environment East China University of TechnologyNanchang 330013China College of Nuclear Science and Engineering East China University of TechnologyNanchang 330013China Center for Computational Materials Science Department of PhysicsUniversity of MalakandChakdaraPakistan College of Physics and Optoelectronic Engineering Shenzhen UniversityShenzhen 518060China College of Electronic Science and Technology Shenzhen UniversityShenzhen 518000China

Structural geometry, electronic band gaps, density of states, optical and mechanical properties of double perovskite halides Cs2InBiX6(X = F, Cl, Br, I) are investigated using the density functional theory. These compounds possess genuine perovskite stoichiometry, evaluated using various geometry-based indices like tolerance factor, octahedral factor, and formation energy. The fundamental electronic band gaps are direct and valued in the range 0.80–2.79 e V. These compounds have narrow band gaps(except Cs2InBiX6) due to strong orbital coupling of the cations. The valence band maximum and conduction band minimum are confirmed to be essentially of In 5 s and Bi 6 p characters, respectively. The splitting of Bi 6 p bands due to strong spin-orbit coupling causes reduction in the band gaps. These compounds have large dispersion in their bands and very low carrier effective masses. The substitution of halogen atoms has great influence on the optical properties. The mechanical properties reveal that Cs2InBiX6(X = F, Cl, Br, I) satisfy the stability criteria in cubic structures.

关键词： optical materials metal halides density functional theory perovskite stoichiometry spin-orbit coupling

Integrated optical vortex beams:Ultrafast orbital angular momentum sources beyond traditional spatial light modulators

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Science Bulletin 2024年第17期69卷 2647-2649页

作者： imad Agha Department of Physics University of DaytonDayton OH 45469USA Department of Electro-Optics and Photonics University of DaytonDayton OH 45469USA

The rapid expansion of the field of optical communications,in both its classical and quantum variants,has led to a desire to increase the bandwidth available for encoding information[1,2].Effects such as crosstalk[3]due to polarization rotation,linearly polarized(LP)mode interactions,four-wave mixing,and linear dispersion often reduce the maximum achievable bandwidth in classical communication systems,while degrading the fidelity and security of their quantum *** angular momentum(OAM)modes are independent eigenstates suitable for spatial division multiplexing in fiber and free-space transmission.

关键词： momentum angular quantum

Deep Learning Approach for Hand Gesture Recognition:Applications in Deaf Communication and Healthcare

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Computers, Materials & Continua 2024年第1期78卷 127-144页

作者： Khursheed Aurangzeb Khalid Javeed Musaed Alhussein imad Rida Syed Irtaza Haider Anubha Parashar Department of Computer Engineering College of Computer and Information SciencesKing Saud UniversityP.O.Box 51178Riyadh11543Kingdom of Saudi Arabia Department of Computer Engineering College of Computing and InformaticsUniversity of SharjahSharjah27272United Arab Emirates Laboratory Biomechanics and Bioengineering University of Technology of CompiegneCompiegne60200France Department of Computer Science and Engineering Manipal University JaipurJaipur303007India

Hand gestures have been used as a significant mode of communication since the advent of human *** facilitating human-computer interaction(HCI),hand gesture recognition(HGRoc)technology is crucial for seamless and error-free *** technology is pivotal in healthcare and communication for the deaf *** significant advancements in computer vision-based gesture recognition for language understanding,two considerable challenges persist in this field:(a)limited and common gestures are considered,(b)processing multiple channels of information across a network takes huge computational time during discriminative feature ***,a novel hand vision-based convolutional neural network(CNN)model named(HVCNNM)offers several benefits,notably enhanced accuracy,robustness to variations,real-time performance,reduced channels,and ***,these models can be optimized for real-time performance,learn from large amounts of data,and are scalable to handle complex recognition tasks for efficient human-computer *** proposed model was evaluated on two challenging datasets,namely the Massey University Dataset(MUD)and the American Sign Language(ASL)Alphabet Dataset(ASLAD).On the MUD and ASLAD datasets,HVCNNM achieved a score of 99.23% and 99.00%,*** results demonstrate the effectiveness of CNN as a promising HGRoc *** findings suggest that the proposed model have potential roles in applications such as sign language recognition,human-computer interaction,and robotics.

关键词： Computer vision deep learning gait recognition sign language recognition machine learning

Evaluation of phase change materials for a light-weight building in Morocco:Effect of building’s volume,window orientation&infiltration

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Energy and Built Environment 2024年第6期5卷 863-877页

作者： imad Ait Laasri Niima Es-sakali Abdelkader Outzourhit Mohamed Oualid Mghazli Laboratory(LaMEE) Faculty of Sciences SemlaliaCadi Ayyad UniversityMarrakeshMorocco Laboratory(LMAID) Rabat National School of MineRabatMorocco Green Energy Park(UM6P/IRESEN) km2 R206BenguerirMorocco ENTPE LTDS UMR CNRS 5513Universitéde LyonCedexVaulx-en-VelinFrance

In this study,we will model a light-weight building made of phase change materials(PCMs)to analyze the impact of the building volume,window orientation,and air infiltration on the PCM *** is done by calculating the energy savings attained by the use of PCM across all of ***’ll use the commercial Rubitherm panels with RT28HC as a phase change material in this ***,the EnergyPlus simulation engine is chosen to perform the *** impact of building volumes is also evaluated on the PCM activation for light-weight square buildings with different side lengths of 10 m,9 m,8 m,and 7 ***,we looked at how well the PCM performed in terms of energy savings and thermal regulation at different window orientation placements(south,north,west,and east)and various air infiltration rates(0.5,1,1.5,and 3 ACH).This paper’s primary objective is to determine the energy savings for the PCM-enhanced building in Morocco,as well as the effect of building volume,window orientation,and infiltration on the PCM capabilities for stabilizing the indoor room *** results show good indoor temperature stabilization during the summer,for the light-weight square building with a south-facing window and no air *** configuration was able to achieve a total fluctuation reduction of 1303.3℃for the 10 m building in a semi-arid ***,a high energy savings percentage of 69.56%was achieved for the PCM-enhanced building with the south-oriented window and air infiltration of 0.5 air change per hour.

关键词： Building energy efficiency Phase change materials Passive thermal regulation

Automatic Finding of Brain-Tumour Group Using CNN Segmentation and Moth-Flame-Algorithm,Selected Deep and Handcrafted Features

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Computers, Materials & Continua 2024年第5期79卷 2585-2608页

作者： imad Saud Al Naimi Syed Alwee Aljunid Syed Junid Muhammad lmran Ahmad K.Suresh Manic Faculty of Electronic Engineering Technology University Malaysia Perils(UniMAP)Pauh Putra CampusArauPerlis02600Malaysia Department of Electrical and Communication Engineering National University of Science and TechnologyAL HailAL Seeb130Sultanate of Oman Department of Research and Innovation Saveetha School of EngineeringSaveetha Institute of Medical and Technical Sciences(SIMATS)ChennaiTamiNadu602105India

Augmentation of abnormal cells in the brain causes brain tumor(BT),and early screening and treatmentwill reduce its harshness in ***’s clinical level screening is usually performed with Magnetic Resonance Imaging(MRI)due to its multi-modality *** overall aims of the study is to introduce,test and verify an advanced image processing technique with algorithms to automatically extract tumour sections from brain MRI scans,facilitating improved *** research intends to devise a reliable framework for detecting the BT region in the twodimensional(2D)MRI slice,and identifying its class with improved *** methodology for the devised framework comprises the phases of:(i)Collection and resizing of images,(ii)Implementation and Segmentation of Convolutional Neural Network(CNN),(iii)Deep feature extraction,(iv)Handcrafted feature extraction,(v)Moth-Flame-Algorithm(MFA)supported feature reduction,and(vi)Performance *** study utilized clinical-grade brain MRI of BRATS and TCIA datasets for the *** framework segments detected the glioma(low/high grade)and glioblastoma class *** work helped to get a segmentation accuracy of over 98%with VGG-UNet and a classification accuracy of over 98%with the VGG16 *** study has confirmed that the implemented framework is very efficient in detecting the BT in MRI slices with/without the skull section.

关键词： Brain tumour VGG-UNet VGG16 moth-flame-algorithm classification

Copernicrinus zamorae *** ***.,the oldest thiolliericrinid crinoid(Crinoidea,Echinodermata) from the Bajocian strata of Algeria,Africa

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Journal of Palaeogeography 2024年第2期13卷 237-251页

作者： Bartosz J.Pιachno Madani Benyoucef Fayc al Mekki Mohammed Adaci imad Bouchemla Sreepat Jain Marcin Krajewski Mariusz A.Salamon Faculty of Biology Institute of BotanyJagiellonian University in KrakowGronostajowa Street 930-387 KrakowPoland Laboratoire de Géomatique Ecologie et EnvironnementMustapha Stambouli University of MascaraDZ-29000 MascaraAlgeria Abou Bekr Belkaid University of Tlemcen TlemcenAlgeria Department of Geological Sciences Faculty of Biological and Agricultural SciencesMouloud Mammeri University of Tizi-OuzouTizi-OuzouAlgeria Adama Science and Technology University School of Applied Natural SciencesDepartment of Applied GeologyP.O.Box 1888AdamaEthiopia Faculty of Geology Geophysics and Environmental ProtectionAGH University of Science and TechnologyAl.A.Mickiewicza 30PL-30-059KrakowPoland Faculty of Natural Sciences University of Silesia in KatowiceBedzinska Street 60PL-41-200 SosnowiecPoland

The thiolliericrinids(Thiolliericrinidae) are comatulids(Comatulida),which retained their stalks as ***,we report a centrodorsal from the Bajocian strata(Middle Jurassic) of the Djebel Kérdacha area,northwestern Algeria(Africa).It is the first thiolliericrinid report from outside of Europe and also the oldest representative of the Thiolliericrinidae whose first occurrence is from the *** crinoid is assigned to Copernicrinus zamorae *** *** reported new taxon shows strong similarities with the stemless ‘true’comatulids,Solanocrinites;the only difference is the presence of a facet to the stem in *** closest comparable thiolliericrinid to Copernicrinus is the Oxfordian Thiolliericrinus,interpreted as a descendant of the *** origin and overview of all thiolliericrinid representatives are also discussed herein.

关键词： Thiolliericrinidae Crinoids Coral facies Bajocian Jurassic Algeria Southern Tethys margin