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Study of magnetic and optical properties of Zn1-xTMxTe(TM = Mn,Fe,Co,Ni) diluted magnetic semiconductors：First principle approach

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Chinese Physics B 2017年第2期26卷 452-460页

作者： Q mahmood M Hassan M A Faridi Department of Physics University of the Punjab Quaid-e-Azam Campus-54590 Lahore Pakistan Centre for High Energy Physics University of the Punjab Lahore Pakistan

We present structural,magnetic and optical characteristics of Zn_（1-x）TM_xTe（TM = Mn,Fe,Co,Ni and x = 6.25%）,calculated through Wien2 k code,by using full potential linearized augmented plane wave（FP-LAPW） *** optimization of the crystal structures have been done to compare the ferromagnetic（FM） and antiferromagnetic（AFM） ground state energies,to elucidate the ferromagnetic phase stability,which further has been verified through the formation and cohesive ***,the estimated Curie temperatures T_c have demonstrated above room temperature ferromagnetism（RTFM） in Zn_（1-x）TM_xTe（TM =Mn,Fe,Co,Ni and x= 6.25%）.The calculated electronic properties have depicted that Mn- and Co-doped ZnTe behave as ferromagnetic semiconductors,while half-metallic ferromagnetic behaviors are observed in Fe- and Ni-doped *** presence of ferromagnetism is also demonstrated to be due to both the p-d and s-d hybridizations between the host lattice cations and TM *** calculated band gaps and static real dielectric constants have been observed to vary according to Penn＇s *** evaluated band gaps lie in near visible and ultraviolet regions,which make these materials suitable for various important device applications in optoelectronic and spintronic.

关键词： magnetic semiconductors density functional theory optical and dielectric properties electron density of states and band structure of crystalline solids

Activating solution gas drive as an extra oil production mechanism after carbonated water injection

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Chinese Journal of Chemical Engineering 2020年第11期28卷 2938-2945页

作者： mahmood Shakiba Shahab Ayatollahi Masoud Riazi Enhanced Oil Recovery(EOR)Research Centre IOR/EOR Research InstituteShiraz UniversityShirazIran Department of Petroleum Engineering Amirkabir University of TechnologyTehranIran School of Chemical and Petroleum Engineering Sharif University of TechnologyTehranIran

Enhanced oil recovery(EOR)methods are mostly based on different phenomena taking place at the interfaces between fluid–fluid and rock–fluid *** the last decade,carbonated water injection(CWI)has been considered as one of the multi-objective EOR techniques to store CO2 in the hydrocarbon bearing formations as well as improving oil recovery *** CWI process,as the reservoir pressure declines,the dissolved CO2 in the oil phase evolves and gas nucleation phenomenon would *** a result,it can lead to oil saturation restoration and subsequently,oil displacement due to the hysteresis *** this condition,CO2 would act as insitu dissolved gas into the oil phase,and play the role of an artificial solution gas drive(SGD).In this study,the effect of SGD as an extra oil recovery mechanism after secondary and tertiary CWI(SCWI-TCWI)modes has been experimentally investigated in carbonate rocks using coreflood *** depressurization tests resulted in more than 25%and 18%of original oil in place(OOIP)because of the SGD after SCWI and TCWI tests,*** the ultimate enhanced oil recovery point of view,the efficiency of SGD was observed to be more than one-third of that of CWI ***,the pressure drop data revealed that the system pressure depends more on the oil production pattern than water production.

关键词： Solution gas drive Gas nucleation Carbonated water Enhanced oil recovery CO2 capture

Assessing effectiveness of nature-based solution with big earth data:60 years mangrove plantation program in Bangladesh coast

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Ecological Processes 2023年第1期12卷 165-192页

作者： Riffat mahmood Li Zhang Guoqing Li Key Laboratory of Digital Earth Science Aerospace Information Research InstituteChinese Academy of SciencesBeijing 100094China College of Resources and Environmental Studies University of Chinese Academy of SciencesBeijing 100094China Department of Geography and Environment Faculty of Life and Earth SciencesJagannath UniversityDhaka 1100Bangladesh International Research Center of Big Data for Sustainable Development Goals Beijing 100094China

Background In the climate change context,nature-based solution(NBS)is considered one of the effective tools to increase the resilience of socio-ecological *** concept coincides with the government’s attempts of afforestation and reforestation programs that have been going on for 60 years in *** study,therefore,envisaged understanding how NBS(mangrove afforestation and reforestation)works to promote climate change resilience through the synthetization of remote sensing-based big earth data,statistical tools,and *** study took the entire coast of Bangladesh except for Sundarbans Reserve Forest and rolled back to 1962 to work on 60 years’time series *** CORONA satellite imagery along with Landsat satellite imagery was used,which is the first-ever attempt in the remote sensing-based ecosystem work in *** The study’s main innovation is to spatially establish the effectiveness of the *** study critically assessed and estimated stable lands and their socio-economic benefits as part of the effectiveness of the *** part of the NBS-derived benefits in the context of climate change,it estimated the sequestrated carbon in mangrove forests.A significant positive relationship was observed between the increase of mangroves and stable *** about 448,011 ha of agricultural land was stabilized due to the NBS intervention whose economic value is 18,837 million *** addition,29,755.71 kt of carbon have been sequestrated due to NBS *** The concept of NBS is still in the development stage and very little or no work has been done so far in measuring and labeling the effectiveness of the ***,our study can innovatively contribute to the scientific community to show the effectiveness of the NBS in three domains(social,economic and ecological)in the changing climatic scenario.

关键词： Nature-based solution(NBS) Mangrove afforestation program Coast Geographic Information System Remote sensing CORONA satellite image Land stabilization Sequestrated carbon Climate change

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Location of Disaster Management Bases Using Spatial Analysis

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Journal of Systems Science and Systems Engineering 2024年第1期33卷 1-29页

作者： Hadi Nayyeri Sahar Zandi mahmood Souri Department of Geomorphology Faculty of Natural ResourceUniversity of KurdistanSanandajKurdistanIran Department of Geography Sciences Kharazmi UniversityTehranIran Red Crescent Society of the Islamic Republic Employee of Iran HamedanIran

Pre-crisis management involves the optimal selection of relief and rescue centers to minimize *** is particularly vulnerable due to its location on the Alpine-Himalaya seismic belt,resulting in an average death rate six times higher than the global average during ***,selecting appropriate relief and rescue centers is crucial to Iran’s disaster *** selecting the placement of rescue centers,accessibility and the appropriateness of the land should be taken into account as well as the distance from high-risk *** location of these centers does not require any particular *** address this issue,a study was conducted utilizing GIS,artificial neural networks,fuzzy logic,and mathematical models to determine the optimal placement based on 12 indicators within two clusters:natural and *** examine the information layers of the initial stage,a spatial data repository concerning the variables impacting the placement of these centers was established using *** functions and algorithms such as Fuzzy Logic in IDRISI,TOPSIS,and VIKOR software,the layers were assessed for weightage before being *** study’s analysis of the models used revealed that the positioning priority limits of the areas differed across all four ***,the areas with high desirability varied to a greater extent:the fuzzy model varied by 9.3%,neural network by 12.4%,VIKOR by 4.5%,and TOPSIS by 16.2%.The variance in results can be attributed to the differing levels of risk acceptance and non-acceptance in each ***,the study yielded other significant findings such as the correlation between study area size and model ***,smaller study areas exhibited higher model *** research also demonstrated that both fuzzy and VIKOR models achieved greater *** a result,employing these models in crisis management planning,particularly in pre-crisis management for identifying rescue center lo

关键词： Crisis management GIS earthquake risk site selection

Complex neutrosophic generalised dice similarity measures and their application to decision making

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CAAI Transactions on Intelligence Technology 2020年第2期5卷 78-87页

作者： Zeeshan Ali Tahir mahmood Department of Mathematics and Statistics International Islamic UniversityIslamabadPakistan

Complex neutrosophic set(CNS)is a modified version of the complex fuzzy set,to cope with complicated and inconsistent information in the environment of fuzzy set *** CNS is characterised by three functions expressing the degree of complex-valued membership,complex-valued abstinence and degree of complex-valued *** aim of this manuscript is to initiate the novel dice similarity measures and generalised dice similarity using *** special cases of the investigated measures are discussed with the help of some ***,some distance measures based on CNS are also proposed in this ***,the authors applied the generalised dice similarity measures and weighted generalised dice similarity measures using CNS to the pattern recognition model to examine the reliability and superiority of the established *** advantages and comparative analysis of the proposed measures with existing measures are also discussed in *** last,a numerical example is provided to illustrate the validity and applicability of the presented measures.

关键词： theory. similarity valued

The NF-Number of a Simplicial Complex

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Algebra Colloquium 2022年第4期29卷 643-650页

作者： Takayuki Hibi Hasan mahmood Department of Pure and Applied Mathematics Graduate School of Information Science and Technology Osaka University SuitaOsaka 565-0871Japan Department of Mathematics Government College University LahorePakistan

Let△bea simplicial complex on[n].TheNF-complex of△is the simplicial complexδ_(NF)(△)on[n]for which the facet ideal of△is equal to the Stanley-Reisner ideal ofδ_(NF)(△).Furthermore,for each k=2,3,....,we introduce the kth NF-complexδ_(NF)^(k)(△),which is inductively defined asδ_(NF)(k)(△)=δ_(NF)(δ_(NF)^(k-1)(△))by settingδ_(NF)^(1)(△)=δ_(NF)(△).One canδ_(NF)^(0)(△)=△.The NF-number of△is the smallest integer k>0 for whichδ_(NF)^(k)(△)■△.In the present paper we are especilly interested in the NF-number of a finite graph,which can be regraded as a simplicial complex of dimension *** is shown that the NF-number of the finite graph K_(n)■K_(m)on[n+m],which is the disjoint union of the complete graphs K_(n)on[n]and K_(m)on[m]for n≥2 and m≥2 with(n,m)≠(2,2),is equal to n+m+*** a corollary,we find that the NF-number of the complete bipartite graph K_(n,m)on[n+m]is also equal to n+m+2.

关键词： Stanley-Reisner complex facet ideal simplicial complex vertex cover

Ab-initio calculations of bandgap tuning of In1-xGaxY(Y=N,P)alloys for optoelectronic applications

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Chinese Physics B 2021年第11期30卷 467-474页

作者： Muhammad Rashid Jamil M mahmood Q Shahid M Ramay Asif mahmood A Ghaithan H M Department of Physics Ghazi University City CampusDera Ghazi Khan32200Pakistan Department of Physics COMSATS University IslamabadIslamabad 44000Pakistan Basic and Applied Scientific Research Center(BASRC) College of Science of DammamImam Abdulrahman Bin Faisal UniversityP.O.Box 383Dammam 31113Saudi Arabia Department Physics College of ScienceImam Abdulrahman Bin Faisal UniversityP.O.Box 1982Dammam 31441Saudi Arabia Physics and Astronomy Department College of ScienceKing Saud UniversityRiyadhSaudi Arabia Chemical Engineering Department College of EngineeringKing Saud UniversityRiyadhSaudi Arabia

The III–V alloys and doping to tune the bandgap for solar cells and other optoelectronic devices has remained a hot topic of research for the last few *** the present article,the bandgap tuning and its influence on optical properties of In1-xGaxN/P,where(x=0.0,0.25,0.50,0.75,and 1.0)alloys are comprehensively analyzed by density functional theory based on full-potential linearized augmented plane wave method(FP-LAPW)and modified Becke and Johnson potentials(TB-mBJ).The direct bandgaps turn from 0.7 eV to 3.44 eV,and 1.41 eV to 2.32 eV for In1-xGaxN/P alloys,which increases their potentials for optoelectronic *** optical properties are discussed such as dielectric constants,refraction,absorption,optical conductivity,and *** light is polarized in the low energy region with minimum *** absorption and optical conduction are maxima in the visible region,and they are shifted into the ultraviolet region by Ga ***,static dielectric constant e1(0)is in line with the bandgap from Penn’s model.

关键词： density functional theory direct bandgap III-V semiconductors tuning of optical band gap solar cell applications

Properties of Defect Modes in Periodic Lossy Multilayer with Negative-Index-Materials

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Communications in Theoretical Physics 2013年第7期60卷 80-86页

作者： Alireza Aghajamal mahmood Barati Department of Physics Science and Research Branch Islamic Azad University Young Researchers Club Science and Research Branch Islamic Azad University

Employing the characteristic matrix method, this study investigates transmission properties of onedimensional defective lossy photonic crystals composed of negative and positive refractive index layers with one lossless defect layer at the center of the crystal. The results of the study show that as the refractive index and thickness of the defect layer increase, the frequency of the defect mode decreases. In addition, the study shows that the frequency of the defect mode is sensitive to the incidence angle, polarization, and physical properties of the defect layer, but it is insensitive to the small lattice loss factor. The peak of the defect mode is very sensitive to the loss factor, incidence angle, polarization, refractive index, and thickness of the defect layer. This study also shows that the peak and the width of the defect mode are affected by the numbers of the lattice period and the loss factor. The results can lead to designing new types of narrow filter structures and other optical devices.

关键词： one-dimensional photonic crystal defect mode loss factor negative index material

Complex Network Formation and Analysis of Online Social Media Systems

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Computer Modeling in Engineering & Sciences 2022年第3期130卷 1737-1750页

作者： Hafiz Abid mahmood Malik Faculty of Computer Studies Arab Open UniversityA’aliKingdom of Bahrain

To discover and identify the influential nodes in any complex network has been an important *** is a significant factor in order to control over the *** control on a network,any information can be spread and stopped in a short span of *** targets can be achieved,since network of information can be extended and as well ***,information spread and community formation have become one of the most crucial issues in the world of SNA(Social Network Analysis).In this work,the complex network of twitter social network has been formalized and results are *** this purpose,different network metrics have been *** of the network is provided in its original form and then filter out(different percentages)from the network to eliminate the less impacting nodes and edges for better *** network is analyzed according to different centrality measures,like edge-betweenness,betweenness centrality,closeness centrality and eigenvector *** nodes are detected and their impact is observed on the *** communities are analyzed in terms of network coverage considering theMinimum Spanning Tree,shortest path distribution and network *** is found that these are the very effective ways to find influential and central nodes from such big social networks like Facebook,Instagram,Twitter,LinkedIn,etc.

关键词： Complex network data extraction nodes and edges network visualization social media network main hubs centrality measures