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The Efect of the Earthed Electrode Size on the Ignition Voltage of Low-Pressure RF Capacitive Discharge in Argon

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Plasm. Science and Technology 2013年第9期15卷 881-884页

作者： A. A. AZOOZ m. A. ahmad Departm.nt of Physics College of ScienceMosul University Departm.nt of Physics College of EducationMosul University

The effect of the grounded electrode diam.ter on the ignition voltage using 13.56 m.z in argon gas is studied experim.ntm.y. The results indicate a system.tic decrease of the breakdown voltage with increasing electrode area for the sam. pd value. No m.lti-valued breakdown voltages are observed. The Paschen m.nim.m.is not affected by the electrode diam.ter as long as the parallel plane approxim.tion is valid. A m.dified Paschen equation which takes into account indirect discharge via the cham.er walls at high pd values gives reasonable fits to the experim.ntal data.

关键词： CCRF electrode size Paschen law RF plasm.

Petrographical and geochem.cal signatures of Jurassic rocks of Chari Form.tion, Western India： im.lications for provenance and tectonic setting

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Acta Geochim.ca 2016年第2期35卷 184-202页

作者： Shaista Khan A. H. m. ahmad m. m.sroor Alam.Adnan Quasim Departm.nt of Geology Aligarh Muslim University AligarhUP. India Geology Section Civil Engineering Z.H. College of Engineering and Technology Aligarh Muslim UniversityAligarh UP India

m.m.ers The sandstones of the Ridge and Athleta of Chari Form.tion （Callovian-Oxfordian） exposed at Jara have been analyzed for their petrographical and geochem.cal studies. Texturally, these sandstones are m.dium.to coarse grained, poorly to well sorted, sub-an- gular to sub-rounded, and show low to m.dium.sphericity. These sandstones were derived from.a m.xed provenance including granites, granite-gneisses, low and high-grade m.tam.rphic, and som. basic rocks of Aravalli range and Nagarparkar m.ssif. The petrofacies analysis reveals that these sandstones belong to the continental block and recycled orogen tectonic regim.. The studied sandstones are m.dified by paleoclim.te, distance of transport, and diagenesis. m.neralogically and geochem.cally, sandstones are classified as quartzarenite, subarkose, arkose, sublithic arenite, and wacke, respectively. The A-CN-K ternary plot and CIA, CIW, PIA, and ICV values suggest that the sim.lar source rocks suffered m.derate to high chem.cal weathering under a hot-hum.d clim.te in an acidic envi- ronm.nt with higher Pco2. Generally good to strong cor- relations between AI2O3 and other oxides in these sedim.nts indicate clay m.neral control. The K2O/Na2O versus SiO2 diagram.indicates that the studied sam.les occupy passive m.rgin fields but the SiO2/A12O3 versus K2O/Na20 plot suggests that the Athleta Sandstone and Ridge Sandstone fall within the passive m.rgin field, while Ridge Shale falls within the active continental m.rgin field.

关键词： Petrography Geochem.stry Jurassic rocks Chari Form.tion Kachchh Gujarat

Crystallization and Hardness of m.lt Spun Fe_(73)Si_(13)B_9Nb_4Cu_1 Alloy

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Journal of m.terials Science & Technology 2009年第1期25卷 48-52页

作者： J.I. Akhter m. Iqbal m. Siddique m. ahmad m.A. Haq m.A. Shaikh Z.Q. Hu Physics Division Pakistan Institute of Nuclear Science and Technology P. O. Nilore Islamabad Pakistan Shenyang National Laboratory for m.terials Science Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China Departm.nt of Chem.cal and m.terials Engineering Pakistan Institute of Engineering and Applied Sciences P.O. Nilore Islamabad Pakistan

An alloy having com.osition Fe73Si13B9Nb4Cu1 was synthesized by m.lt spinning to investigate the kinetics of crystallization. Techniques of differential scanning calorim.try （DSC）, X-ray diffraction （XRD） and m.ssbauer spectroscopy were em.loyed to characterize the phases produced due to annealing at various tem.eratures. High tem.erature DSC revealed two stage crystallization reactions. First stage, crystallization occurs at tem.erature around 514℃ with the production of α-Fe （bcc） and Fe3Si phases. In the second stage, Fe2B and α-Fe （Si,Nb） phases were produced. m.ssbauer results revealed the form.tion of Fe3Si, Fe13Si3 and Fe7Si1 in the first stage and Fe3Si, Fe13Si3, Fe2B and α-Fe （Si,Nb） phases in the second stage of crystallization. An abrupt change in average internal m.gnetic field was observed at 500℃. The m.xim.m.hardness value was found for the sam.le heat-treated at 500℃.

关键词： Am.rphous alloy Crystallization m.ssbauer spectroscopy Hardness

Study of Duct Characteristics Deduced from.Low Latitude Ground Observations of Day-Tim. Whistler at Jam.u

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International Journal of Astronom. and Astrophysics 2013年第3期3卷 274-277页

作者： m. Altaf m. m. ahmad Departm.nt of Physics National Institute of Technology Srinagar India

Propagation characteristics of low latitude whistler duct characteristics have been investigated based on day-tim. m.asurem.nts at Jam.u. The m.rphogical characteristics of low latitude whistlers are discussed and com.ared with characteristics of m.ddle and high latitude whistlers. The m.x. electron density (Nm. at the height of the ionosphere obtained from.whistler dispersion com.s out to be higher than that of the background which is in accordance with the characteristics of whistler duct. The equivalent width is found to be close to the satellite observations and the characteristics of whistler duct in low latitude ionosphere are sim.lar to those in m.ddle and high latitude ionosphere. The width of ducts estim.ted from.the diffuseness of the whistler track observed during m.gnetic storm.is found to lie in the range of 50 - 200 Km.

关键词： Electron Density Dispersion Duct Whistlers Ionosphere

m.deling of Diffuse Solar Radiation and Im.act of Com.lex Terrain over Pakistan Using RS/GIS

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Journal of Geographic Inform.tion System 2014年第4期6卷 404-413页

作者： Shahzad Sultan Renguang Wu Iftikhar ahmad m. Fahim.ahmad Departm.nt of Geography University of Balochistan Quetta Pakistan Institute of Space and Earth Inform.tion Science Chinese University of Hong Kong Hong Kong China Nanjing University of Inform.tion Science and Technology Nanjing China

Diffuse solar radiation is subject to the com.ined influence of ground and sky factors, such as topography, geography of the area and cloud cover. This study attem.ts to quantify the im.acts of topography, sky factors and the cloud cover on the distribution of diffuse solar radiation over Pakistan. Distributed m.deling approach by considering anisotropy scattering m.chanism.was adopted. Digital elevation m.del and observed data are used to derive average m.nthly diffuse solar radiation values over the rugged terrains of Pakistan. Extraterrestrial solar radiation m.del, sky view factor m.del (openness m.del) and digital elevation m.del (DEm. are applied to investigate the im.acts of ground factors, while diffuse solar radiation m.del for horizontal surface was considered for sky factors. Furtherm.re, corrected m.DIS cloud fraction data are incorporated using GIS plat form. Results show that the highest am.unt of diffused solar radiation occurs during the m.nsoon m.nths along the eastern side of the River Indus, when the sky is covered by clouds of various heights and densities. The variation due to topography is evident in m.untainous areas, particularly in the North Pakistan and over the Baluchistan Plateau.

关键词： Rugged Terrain Diffuse Radiation Pakistan GIS DEm

Novel Fram.work for an Intrusion Detection System.Using m.ltiple Feature Selection m.thods Based on Deep Learning

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Tsinghua Science and Technology 2024年第4期29卷 948-958页

作者： A.E.m.Eljialy m.ham.ed Yousuf Uddin Sultan ahmad Departm.nt of Inform.tion System. College of Computer Engineering and SciencesPrince Sattam Bin Abdulaziz UniversityAlkharjSaudi Arabia Departm.nt of Com.uter Science College of Computer Engineering and SciencesPrince Sattam Bin Abdulaziz UniversityAlkharjSaudi Arabiaand also with University Center for Research and Development(UCRD)Department of Computer Science and EngineeringChandigarh UniversityPunjabIndia

Intrusion detection system. (IDSs) are deployed to detect anom.lies in real tim.. They classify a network’s incom.ng traffic as benign or anom.lous (attack). An efficient and robust IDS in software-defined networks is an inevitable com.onent of network security. The m.in challenges of such an IDS are achieving zero or extrem.ly low false positive rates and high detection rates. Internet of Things (IoT) networks run by using devices with m.nim.l resources. This situation m.kes deploying traditional IDSs in IoT networks unfeasible. m.chine learning (m.) techniques are extensively applied to build robust IDSs. m.ny researchers have utilized different m. m.thods and techniques to address the above challenges. The developm.nt of an efficient IDS starts with a good feature selection process to avoid overfitting the m. m.del. This work proposes a m.ltiple feature selection process followed by classification. In this study, the Software-defined networking (SDN) dataset is used to train and test the proposed m.del. This m.del applies m.ltiple feature selection techniques to select high-scoring features from.a set of features. Highly relevant features for anom.ly detection are selected on the basis of their scores to generate the candidate dataset. m.ltiple classification algorithm. are applied to the candidate dataset to build m.dels. The proposed m.del exhibits considerable im.rovem.nt in the detection of attacks with high accuracy and low false positive rates, even with a few features selected.

关键词： random.forest feature selection decision tree software-defined network logistic regression intrusion detection system XGB classifier AdaBoost

A Reputation-Based AODV Protocol for Blackhole and m.lfunction Nodes Detection and Avoidance

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Com.uters, m.terials & Continua 2024年第8期80卷 1867-1888页

作者： Qussai m.Yaseen m.nther Aldwairi ahmad m.nasrah Artificial Intelligence Research Center(AIRC) College of Engineering and Information TechnologyAjman UniversityAjman346United Arab Emirates Departm.nt of Com.uter Inform.tion System. Faculty of Computer and Information TechnologyJordan University of Science and TechnologyIrbid22110Jordan College of Technological Innovation Zayed UniversityAbu Dhabi144534United Arab Emirates Faculty of Inform.tion Technology and Com.uter Science Yarmouk UniversityIrbid21163Jordan Com.uter Inform.tion System. Higher Colleges of TechnologySharjah341214United Arab Emirates

Enhancing the security of Wireless Sensor Networks(WSNs)im.roves the usability of their ***,finding solutions to various attacks,such as the blackhole attack,is crucial for the success of WSN *** paper proposes an enhanced version of the AODV(Ad Hoc On-Dem.nd Distance Vector)protocol capable of detecting blackholes and m.lfunctioning benign nodes in WSNs,thereby avoiding them.when delivering *** proposed version em.loys a network-based reputation system.to select the best and m.st secure path to a *** achieve this goal,the proposed version utilizes the Watchdogs/Pathrater m.chanism. in AODV to gather and broadcast reputations to all network nodes to build the network-based reputation *** m.nim.ze the network overhead of the proposed approach,the paper uses reputation aggregator nodes only for forwarding reputation ***,to reduce the overhead of updating reputation tables,the paper proposes three m.chanism.,which are the prom.t broadcast,the regular broadcast,and the light broadcast *** proposed enhanced version has been designed to perform.effectively in dynam.c environm.nts such as m.bile WSNs where nodes,including blackholes,m.ve continuously,which is considered a challenge for other *** the proposed enhanced protocol,a node evaluates the security of different routes to a destination and can select the m.st secure routing *** paper provides an algorithm.that explains the proposed protocol in detail and dem.nstrates a case study that shows the operations of calculating and updating reputation values when nodes m.ve across different ***,the paper discusses the proposed approach’s overhead analysis to prove the proposed enhancem.nt’s correctness and applicability.

关键词： AODV blackhole m.lfunction nodes pathrater reputation system wireless sensor networks(WSNs) watchdogs

Narrow Band Im.ging Can Be Used for Anastom.tic Assessm.nt

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Surgical Science 2016年第2期7卷 126-135页

作者： Ahm.d Z. Kaleem.Nabish Naheed Syed m. ahmad Departm.nt of Colorectal Surgery Northern Lincolnshire and Goole Hospital Scunthorpe UK NHS Foundation Trust Scunthorpe General Hospital Scunthorpe UK

Background: Anastom.tic leak is the m.st dreaded com.lication and it accounts for one third of post-operative deaths in colorectal surgery. There is strong need of research in this field in order to reduce anastom.tic leak rate. If there was a test available to signify probability of leak at the tim. of surgery, it would potentially avoid a leak at a later date. Aim. We propose that intra operative use of narrow band im.ging colonoscopy in left sided colonic anastom.sis can predict and detect anastom.sis related problem., problem. i.e. vascularity, anastom.tic lum.n patency and rigidness of anastom.sis which in turn lead to correction at the tim. of surgery resulting in significant decrease in anastom.tic leak rate associated with m.rbidity and m.rtality. m.thodology: A pilot, single blind, prospective, random.sed controlled trial. Aim.is to divide patient in 2 groups, containing 15 patients in each group. One group will be assessed by intra-operative NBI colonoscopy and other with standard technique. Analysis: This will be perform.d using SPSS with the help of statistician. Significance: This area of research is particularly im.ortant because it im.roves survival by reducing m.rbidity and m.rtality associated with anastom.tic leak. If a leak is avoided then it does not only m.an early recovery but it also saves NHS in term. of ICU care, NHS bed, inpatient nursing care and hom. help, unfortunately all required if leak is to occur. As a result, this research will have better financial im.lication with significantly im.rove patient care.

关键词： Anastom.tic Leak Colorectal Surgery Anastom.tic Assessm.nt

Correlation between structural phase transition and physical properties of Co^(2+)/Gd^(3+)co-substituted copper ferrite

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Journal of Rare Earths 2024年第7期42卷 1344-1353,I0006页

作者： m.hsen Choupani ahmad Gholizadeh School of Physics Damghan UniversityDamghan36716-45667Iran

The doping of the spinel ferrites with selective cations usually im.roves the properties of the parent *** effect of Co^(2+)/Gd^(3+)co-substitution on the m.crostructure,optical,and m.gnetic properties of Cu1-xCoxFe2-xGdxO4 prepared by the citrate-nitrate auto-com.ustion synthesis was *** of the sam.les was perform.d with powder X-ray diffraction(XRD),Ram.n and Fouriertransform.infrared(FTIR)spectroscopy,field-em.ssion scanning electron m.croscopy,X-ray energydispersive spectroscopy,UV-Vis spectroscopy,and a vibrating sam.le *** results of XRD,Ram.n,and FTIR analysis show a gradual structural phase transition from.a tetragonal(I41/am.)structure to a cubic(Fd3m.*** bandgap energy of the studied sam.les is in a range of 1.57-1.75 eV with a m.nim.m.in sam.le x=0.06 and then *** investigations show that the presence of Co^(2+)/Gd^(3+)cations in an octahedral site of the copper ferrite structure could increase saturation m.gnetization and coercive field from.567.9 Oe and 23.62 em./g to 929.4 Oe and 28.27 em./g,respectively.

关键词： Spinel copper ferrite Citrate-nitrate m.thod Structure phase transition m.crostructure properties m.gnetic properties Rare earths