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Power Allocation Strategy for Secret Key Generation Method in Wireless Communications

Computers, Materials & Continua 2021年第8期68卷 2179-2188页

作者： Bin Zhang muhammad waqas Shanshan Tu Syed Mudassir Hussain Sadaqat Ur Rehman School of Electronics and Information Engineering Hunan University of Science and EngineeringYongzhou425199China Engineering Research Center of Intelligent Perception and Autonomous Control Faculty of Information TechnologyBeijing University of TechnologyBeijing100124China Faculty of Computer Science and Engineering Ghulam Ishaq Khan(GIK)Institute of Engineering Sciences and TechnologyTopi23460Pakistan Department of Electronics Engineering FICTBalochistan University of Information TechnologyEngineering and Management SciencesQuetta87300Pakistan Department of Computer Science Namal InstituteMianwali42200Pakistan

Secret key generation(SKG)is an emerging technology to secure wireless communication from ***,the SKG at the physical layer is an alternate solution over traditional cryptographic methods due to wireless channels’***,the physical layer secret key generation(PHY-SKG)depends on two fundamental parameters,i.e.,coherence time and power *** coherence time for PHY-SKG is not applicable to secure wireless *** is because coherence time is for a certain period of ***,legitimate users generate the secret keys(SKs)with a shorter key length in ***,an attacker can quickly get information about the ***,the attacker can easily get valuable information from authentic ***,we considered the scheme of power allocation to enhance the secret key generation rate(SKGR)between legitimate ***,we propose an alternative method,i.e.,a power allocation,to improve the *** results show 72%higher SKGR in bits/sec by increasing power *** addition,the power transmission is based on two important parameters,i.e.,epsilon and power loss factor,as given in power transmission *** found out that a higher value of epsilon impacts power transmission and subsequently impacts the *** SKGR is approximately 40.7%greater at 250 from 50 mW at epsilon=*** value of SKGR is reduced to 18.5%at 250 mW when epsilonis ***,the transmission power is also measured against the different power loss factor values,i.e.,3.5,3,and 2.5,respectively,at epsilon=***,it is concluded that the value of epsilon and power loss factor impacts power transmission and,consequently,impacts the SKGR.

关键词： Secret key generation rate power allocation physical layer wireless communication

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An Optimal Dispatch Strategy for Distributed Microgrids Using PSO

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CSEE Journal of Power and Energy Systems 2020年第3期6卷 724-734页

作者： muhammad Yousif Qian Ai Yang Gao waqas Ahmad Wattoo Ziqing Jiang Ran Hao Key Laboratory of Control of Power Transmission and Conversion(SJTU) Ministry of EducationShanghai 200240China Department of Electrical and Computer Engineering COMSATS University Islamabad(CUI)Sahiwal campusPunjab 57000Pakistan

Grid structures are rapidly evolving in view of contemporary energy policies which ensure the addition of more renewable sources to reduce the carbon *** to a centralized approach,low voltage grids(decentralized and distributed)are promising approaches to integrating nondispatchable renewable energy sources(RESs).Installing local micro level power generation sources such as fuel cells,microturbines,and energy storage systems are a recent trend which helps in the intermittent effects of RESs and makes microgrids less dependable on the main *** to the increasing variety of distributed generation sources having diverse characteristics,power dispatch scheduling of distributed microgrids is becoming challenging.A dispatch scheduling solution from an operator’s point of view is presented by the *** core objective of this study is to minimize the carbon emissions and the cost of each ***,it is observed that sales and purchases from the main grid are ***,transmission losses are also decreased.

关键词： Energy management system microgrid multimicrogrid power dispatch PSO Power scheduling strategy

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Spin valve effect of NiFe/graphene/NiFe junctions

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Nano Research 2013年第5期6卷 373-379,380页

作者： muhammad Zahir Iqbal muhammad waqas Iqbal Jae Hong Lee Yong Seung Kim Seung-Hyun Chun Jonghwa Eom Department of Physics and Graphene Research Institute Sejong University Seou1143-747 Korea

When spins are injected through graphene layers from a transition metal ferromagnet, high spin polarization can be achieved. When detected by another ferromagnet, the spin-polarized current makes high- and low-resistance states in a ferromagnet/graphene/ferromagnet junction. Here, we report manifest spin valve effects from room temperature to 10 K in junctions comprising NiFe electrodes and an interlayer made of double-layer or single-layer graphene grown by chemical vapor deposition. We have found that the spin valve effect is stronger with double-layer graphene than with single-layer graphene. The ratio of relative magnetoresistance increases from 0.09% at room temperature to 0.14% at 10 K for single-layer graphene and from 0.27% at room temperature to 0.48% at 10 K for double-layer graphene. The spin valve effect is perceived to retain the spin-polarized transport in the vertical direction and the hysteretic nature of magnetoresistance provides the basic functionality of a memory device. We have also found that the junction resistance decreases monotonically as temperature is lowered and the current-voltage characteristics show linear behaviour. These results revealed that a graphene interlayer works not as a tunnel barrier but rather as a conducting thin film between two NiFe electrodes.

关键词： graphene spin valve magnetic junction magnetoresistance spintronics

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Role of copper grid mesh in the catalytic oxidation of CO over one-step synthesized Cu-Fe-Co ternary oxides thin film

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Chinese Chemical Letters 2020年第5期31卷 1201-1206页

作者： muhammad waqas Patrick Mountapmbeme Kouotou Achraf El Kasmi Yu Wang Zhen-Yu Tian Institute of Engineering Thermophysics Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China National Advanced School of Engineering of Maroua University of MarouaMaroua P.O.Box 46Cameroon Shanghai Research Institute of Petrochemical Technology Shanghai 201208China

The effective valuation of catalyst supports in the catalytic oxidation makes the contribution to understand the support effect of great ***,the role of active substrate in the performance and stability of CuFe-Co ternary oxides was studied towards the complete catalytic oxidation of *** Cu-Fe-Co oxide thin films were deposited on copper grid mesh(CUGM)using one-step pulsed-spray evaporation chemical vapor deposition *** structure and morphology analyses revealed nano-crystallite sizes and do me-top-like *** effects between Cu,Fe and Co,which affect the surface Cu^2+,Fe^3+,Co^3+and chemisorbed oxygen species(O2 and OH)of thin films over the active support and thus result in better *** thin film catalysts supported on CUGM exhibited attractive catalytic activity compared to the te rnary oxides supported on ine rt grid mesh at a high gas hourly space *** r,the stability in time-on-stream of the ternary oxides on CUGM was evaluated in the CO oxidation for 30 *** ad opted deposition strategy ofternary oxides on CUGM presents an excessive amount of adsorbed active oxygen species that play an impo rtant role in the complete CO *** catalysts supported on CUGM showed better catalytic conve rsion than that on inert grid mesh and some literature-reported noble metal oxides as well as transition metal oxides counterparts,revealing the beneficial effect of the CUGM suppo rt in the improvement of the catalytic performance.

关键词： Cu-Fe-Co ternary oxides PSE-CVD technique Support effect Time-on-stream Copper grid mesh

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乳液催化剂存在下空气辅助甲酸氧化法使油品脱硫(英文)

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催化学报 2013年第10期34卷 1839-1847页

作者： Ahmad Imtiaz Ahmad waqas Ishaq muhammad Institute of Chemical Sciences University of Peshawar

Catalytic oxidative desulfurization(ODS) of model oil and commercial oil samples was investigated using an air-assisted performic acid oxidation system with a phase transfer or emulsion catalyst comprising a quaternary ammonium salt-based *** emulsion catalysts with a Keggin type heteroployoxometalate anion(containing W,Mo,and V) and cetyltrimethylammonium bromide cation were prepared and characterized by X-ray fluorescence,Fourier transform infrared spectroscopy,and scanning electron microscopy.[C16H33N(CH3)3]3[PW9Mo3O40] was the most effective catalyst in the current oxidation system,which reduced the sulfur content of the model oil from 1275 μg/g to 57 μg/*** reactivity order of different model sulfur compounds was thiophene < dibenzothiophene < 4,6-dimethyldibenzothiophene. The ODS of model sulfur compounds followed first order kinetics with apparent activation energy from 29 to 27 kJ/*** catalysts also performed efficiently in the ODS of the industrial oil samples,including untreated naphtha,light gas oil,heavy gas oil,and Athabasca oil sands derived bitumen,for which sulfur removal rates were 83%,85%,68% and 64%,respectively.

关键词： Catalytic oxidative desulfurization Performic acid oxidation Emulsion catalyst Heteropolyoxometalate Air oxidation

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Multi-shelled TiO2/Fe2TiO5 heterostructured hollow microspheres for enhanced solar water oxidation

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Nano Research 2017年第11期10卷 3920-3928页

作者： muhammad waqas Yanze Wei Dan Mao Jian Qi Yu Yang Bao Wang Dan Wang State Key Laboratory of Biochemical Engineering CAS Center for Excellence in Nanoscience Institute of Process Engineering Chinese Academy of Sciences 1 North 2nd Street Zhongguancun Haidian District Beijing 100190 China Department of Physical Chemistry School of Metallurgical and Ecological Engineering University of Science & Technology Beijing No.30 Xueyuan Road Haidian District Beijing 100083 China University of Chinese Academy of Sciences Chinese Academy of Sciences No.19A Yuquanlu Beijing 100049 China

There remains a pressing challenge in the fabrication of superior photocatalysts for light-driven water ***,we designed and fabricated heterostructured TiO2/Fe2TiO5 hollow microspheres with single-,double-,closed-double-,triple-,and core-shell structures and different Fe/Ti molar ratios using a facile sequential templating *** closed-double-shelled TiO2/Fe2TiO5 hollow microspheres with 35% Fe exhibited the highest oxygen evolution reaction rate up to 375 μmol＆#183;g-1＆#183;h-1 and good stability for 5 *** high performance can be attributed to the closed-double shell,which had more reactive sites and greater light-harvesting ability,self-supported thin shells with short charge-transfer paths,and a favorable staggered band alignment between the TiO2 and Fe2TiOs.

关键词： multi-shelled hollow microsphere titanium oxide pseudo-brookite heterostructure photocatalytic water oxidation

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Exploring long-term effects of biochar on mitigating methane emissions from paddy soil:a review

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Biochar 2021年第2期3卷 125-134页

作者： Qiong Nan Liqing Xin Yong Qin muhammad waqas Weixiang Wu Institute of Environmental Science and Technology College of Environment and Resource ScienceZhejiang UniversityHangzhou 310029People’s Republic of China Department of Botanical and Environmental Science Kohat University of Science and TechnologyKohat 26000Khyber PakhtunkhwaPakistan

Biochar has been reported to mitigate short-term methane(CH4)emissions from paddy ***,CH4 mitigation by biochar has primarily focused on the abundance and variations of methanogens and methanotrophs,and changes in their activities during methane production and ***,long-term effects of biochar on methane mitigation from paddy soil remain *** review overviewed the existing mechanisms for CH4 mitigation as a result of biochar *** addition,the two existing opinions on the long-term CH4 mitigation effect upon biochar application were *** the already explored mechanisms of fresh biochar on CH4 mitigation from paddy soil and a novel discovery,the potential mechanisms of biochar on long-term methane emission response were *** review also revealed the uncertain responses of biochar on long-term CH4 ***,to achieve carbon neutral goal,it is important to further explore the mechanisms of long-term CH4 mitigation under biochar application.

关键词： Biochar Methane mitigation Methanogens Methanotrophs

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Is Ziarat a Potential Site for Conventional or Unconventional Energy Resources?

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Acta Geologica Sinica(English Edition) 2018年第4期92卷 1544-1557页

作者： Sarfraz KHAN Umair Bin NISAR Khawar A.AHMED muhammad WASEEM waqas AHMED National Centre of Excellence in Geology University of PeshawarPeshawar25130Pakistan Comsats Institute of Information and Technology AbbottabadPakistan Comsats Institute of Information and Technology IslamabadPakistan

A structural interpretation of the Ziarat block in the Balochistan region （a part of the Suleiman Fold and Thrust Belt） has been carried out using seismic and seismological data. Seismic data consists of nine 2.5D pre-stack migrated seismic lines, whereas the seismological data covers the Fault Plane Solution and source parameters. Structural interpretation describes two broad fault sets of fore and back thrusts in the study area that have resulted in the development of pop-up structures, accountable for the structural traps and seismicity pattern in terms of seismic hazard. Seismic interpretation includes time and depth contour maps of the Dungan Formation and Ranikot group, while seismological interpretation includes Fault Plane Solution, that is correlated with a geological and structural map of the area for the interpretation of the nature of the subsurface faults. Principal stresses are also estimated for the Ranikot group and Dungan Formation. In order to calculate anisotropic elastic properties, the parameters of the rock strength of the formations are first determined from seismic data, along with the dominant stresses （vertical, minimum horizontal, and maximum horizontal）. The differential ratio of the maximum and minimum horizontal stresses is obtained to indicate optimal zones for hydraulic fracturing, and to assess the potential for geothermal energy reservoir prospect generation. The stress maps indicate high values towards the deeper part of the horizon, and low towards the shallower part, attributed to the lithological and structural variation in the area. Outcomes of structural interpretation indicate a good correlation of structure and tectonics from both seismological and seismic methods.

关键词： fault plane solution reservoir monitoring stress analysis hydraulic fracturing geothermal energy structural interpretation

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Long-term manure application increased soil organic carbon and nitrogen mineralization through accumulation of unprotected and physically protected carbon fractions

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Pedosphere 2023年第2期33卷 343-354页

作者： muhammad Nadeem ASHRAF Cheng HU Xiangru XU Tariq AZIZ Lei WU muhammad Ahmed waqas muhammad FAROOQ Xu HU Wenju ZHANG Minggang XU Key Laboratory of Cultivated Land Quality Monitoring and Evaluation Ministry of Agriculture and Rural AffairsInstitute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural SciencesBeijing 100081(China) Institute of Soil and Environmental Sciences University of AgricultureFaisalabad 38040(Pakistan) Institute of Plant Protection and Soil Science Hubei Academy of Agricultural SciencesWuhan 430064(China) Institute of Soil and Environmental Sciences University of AgricultureFaisalabadSub-Campus DepalpurOkara 56130(Pakistan) Institute of Environment and Sustainable Development in Agriculture Chinese Academy of Agricultural SciencesBeijing 100081(China) Department of Plant Sciences College of Agricultural and Marine SciencesSultan Qaboos UniversityAl-Khoud 123(Oman) Shanxi Province Key Laboratory of Soil Environment and Nutrient Resources Engineer and Technology Academy of Ecology and EnvironmentShanxi Agricultural UniversityTaiyuan 030031(China)

Soil organic carbon(SOC)and nitrogen(N)mineralization are important biogeochemical processes associated with soil *** processes are influenced by physically,chemically,and biologically stabilized SOC fractions,the mechanisms of which are not well *** present study was conducted to evaluate the combined effect of manure and mineral fertilizers on the contents of SOC fractions to promote the mineralization of SOC and *** included:i)no fertilizer control(CK);ii)a combination of mineral N,phosphorus,and potassium fertilizers(NPK);iii)manure alone(M);iv)manure combined with NPK(MNPK);and v)a high dose of manure combined with NPK(hMNPK).The combined uses of manure and mineral fertilizers(MNPK and hMNPK)enhanced the accumulation of the unprotected coarse particulate organic carbon(C)fraction(cPOC)by 44%-72%compared to *** applications(M,MNPK and hMNPK)enhanced physically microaggregate-protected organic C(μagg),physicochemically protected organic C within the microaggregate-derived silt(μsilt)fraction(H-μsilt),and physicobiochemically protected organic C within theμsilt fraction(NH-μsilt)by 30%-56%,62%-150%,and 27%-51%,*** contrast,all chemically and biochemically protected SOC fractions showed a minor response to manure *** of cPOC,μagg,H-μsilt,and physicochemically protected organic C within the microaggregate-derived clay fraction(H-μclay)significantly contributed to the mineralization of SOC and N,resulting in a significant increase in rice grain yield with long-term manure *** summary,long-term combined use of manure and mineral fertilizers improved SOC accumulation in unprotected and physically protected fractions,which enhanced SOC and N mineralization and benefited soil productivity in a rice-wheat cropping system.

关键词： fertilization strategy grain yield organic C fraction organic matter stabilization protection mechanism

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In-process failure analysis of thin-wall structures made by laser powder bed fusion additive manufacturing

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Journal of Materials Science & Technology 2022年第3期98卷 233-243页

作者： Apratim Chakraborty Reza Tangestani Rasim Batmaz waqas muhammad Philippe Plamondon Andrew Wessman Lang Yuan Étienne Martin University of Waterloo 200 University Avenue WestWaterlooON N2L 3G1Canada Polytechnique Montréal 2500 Chemin de PolytechniqueMontréalQC H3T 1J4Canada University of Arizona 1235 E.James E.Rogers WayTucsonAZ 85721-0012United States University of South Carolina 301 Main StreetColumbiaSC 29208United States

Fabrication of thin-wall components using the laser powder bed fusion(LPBF)additive manufacturing(AM)technology was investigated for two“hard-to-weld”high gamma prime Ni-based superalloys RENé65(R65)and RENé108(R108).Simple block parts with wall thicknesses of 0.25 mm,1.00 mm,and5.00 mm are printed using a bidirectional laser scanning strategy without layer-wise *** with walls thinner than 5 mm fail before reaching the designated build *** indicate that reduction of limiting build height(LBH)corresponds to the reduction of part thickness and is unaffected by alloy *** the contrary,the number of internal micro-cracks along columnar grain boundaries in the build direction(BD)increases with part thickness and is significantly higher in R108 than *** findings suggest that reduced LBH in parts with thinner walls is not caused by internal micro-crack *** and finite element analysis(FEA)of the in-process thermal stresses show that the LBH trend is not explained by the conventional cracking *** suggest that part thickness affects stress distribution leading to more substantial distortion and consequent failure to add layers for continued fabrication of thinner parts.

关键词： Laser powder bed fusion Superalloys Thin-wall Residual stress Additive manufacturing

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