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Particle breakage of sand subjected to friction and collision in drum tests

Journal of Rock mechanics and Geotechnical Engineering 2021年第2期13卷 390-400页

作者： Fangwei Yu Chonglei Zhang Qijun Xie Lijun Su Tao Zhao m.qasim jan Key Laboratory of mountain Hazards and Earth Surface Process of CAS Institute of Mountain Hazards and EnvironmentChinese Academy of SciencesChengdu610041China Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of SciencesBeijing100101China China-Pakistan Joint Research Center on Earth Sciences CAS-HECIslamabad45320Pakistan Department of Civil Engineering The University of TokyoTokyo113-8656Japan University of Chinese Academy of Sciences Beijing100049China Department of Civil and Environmental Engineering Brunel University LondonLondonUB83PHUK National Centre of Excellence in Geology University of PeshawarPeshawar25130Pakistan

This paper presents a laboratory experimental study on particle breakage of sand subjected to friction and collision,by a number of drum tests on granular materials(silica sand No.3 and ceramic balls)to investigate the characteristics of particle breakage and its effect on the characteristics of grain size distribution of *** breakage increased in up convexity with increasing duration of drum tests,but increased linearly with increasing number of *** breakage showed an increase,followed by a decrease while increasing the amount of *** may be existence of a characteristic amount of sand causing a maximum particle *** tests caused much less particle breakage than collision tests *** and collision resulted in different mechanisms of particle breakage,mainly by abrasion for friction and by splitting for *** fines content increased with increasing relative *** breakage in the friction tests(abrasion)resulted in a sharper increase but with a smaller total amount of fines content in comparison with that in the collision tests(splitting).For the collision tests,the fines content showed a decrease followed by an increase as the amount of sand increased,whereas it increased in up convexity with increasing number of *** characteristic grain sizes D_(10) and D_(30) decreased in down convexity with increasing relative breakage,which could be described by a natural exponential ***,the characteristic grain sizes D50 and D60 decreased linearly while increasing the relative *** addition,the coefficients of uniformity and curvature of sand showed an increase followed by a decrease while increasing the relative breakage.

关键词： Grain size distribution Drum tests Granular flow Particle breakage

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Petrogenesis of middle Triassic Volcaniclastic Rocks from Balochistan,Pakistan:Implications for the Break-Up of Gondwanaland

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Journal of Earth Science 2017年第2期28卷 218-228页

作者： Rehanul Haq Siddiqui m.qasim jan m.Ishaq Kakar Andrew C.Kerr Abdul Salam Khan Ehsanullah Kakar Balochistan University of Information Technology Engineering and Management Seiences Quetta 87300 Pakistan National Centre of Excellence in Geology University of Peshawar Pakistan & COMSTECH Islamabad 44000 Pakistan Centre of Excellence in mineralogy University of Balochistan Quetta 87300 Pakistan School of Earth and Ocean Sciences Cardiff University Main Building Park Place Cardiff Wales CF 10 3AT UK

Basaltic volcanic conglomerates near the Wulgai village in Balochistan occur in the undivided sedimentary rock unit of the Bagh complex which is the mélange zone beneath the muslim Bagh ophiolite. The presence of middle Triassic grey radiolarian chert within the upper and lower horizon of the conglomerates suggests that the lavas, from which these conglomerates were principally derived, were eroded and re-deposited in the middle Triassic. The Wulgai conglomerate contains several textural and mineralogical varieties of volcanic rocks, such as porphyritic, glomerophyric, intersertal and vitrophyric basalts. The main minerals identified in these samples are augite, olivine, plagioclase（An35–78） leucite and nosean, with apatite ilmenite, magnetite and hematite occurring as accessory minerals. These rocks are mildly to strongly-alkaline with low mg~# and low Cr, Ni and Co contents suggesting that their parent magma had undergone considerable fractionation prior to eruption. Trace element-enriched mantle-normalized patterns with marked positive Nb anomalies are consistent with 10%–15% melting of an enriched mantle source in a within-plate tectonic setting. It is proposed that this middle Triassic intra-plate volcanism may represent mantle plume-derived melts related to the Late Triassic rifting of micro-continental blocks（including Afghan, Iran, Karakorum and Lhasa） from the northern margin of Gondwana.

关键词： middle Triassic Wulgai volcaniclastics juvenile Ceno-Tethys

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Geochemistry and Tectonic Settings of Felsic Dykes in the Neoproterozoic Nagar Parkar Igneous Complex, SE Sindh, Pakistan

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Acta Geologica Sinica(English Edition) 2016年第S1期90卷 124-页

作者： Tahseenullah Khan mamoru murata m.qasim jan Hafiz Ur Rehman muhammad Zafar Hiroaki Ozawa Anwar Qadir Saqib mehmood Department of Earth and Environmental Sciences Bahria University Department of Geosciences Faculty of Science Naruto University of Education National University Corporation National Centre of Excellence in Geology University of Peshawar and COMSTECH Islamabad Department of Earth and Environmental Science Faculty of Science Kagoshima University International Cooperation Center for the Teacher Education and Training Naruto University of Education Department of Geology Haripur University

The Nagar Parkar complex consists of Neoproterozoic igneous and metamorphic rocks dissected by episodic mafic and felsic *** latter can be classified broadly into porphyritic felsic dykes and aplitic felsic dykes(minor)

关键词： SE Sindh Pakistan Geochemistry and Tectonic Settings of Felsic Dykes in the Neoproterozoic Nagar Parkar Igneous Complex

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VARIATIONS IN KAmILA AmPHIBOLITES FROm SOUTHEASTERN PART OF THE KOHISTAN ISLAND-ARC TERRANE,PAKISTAN

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地学前缘 2000年第S1期7卷 200-200页

作者： m.Ahmed Khan\+1,m.Asif Khan\+2,m.qasim jan\+2[WT5,5”BX](1 Government College,Sargodha,Pakistan 2.National Centre of Excellence in Geology, University of Peshawar,Pakistan)

The Kohistan terrane in *** is sandwiched between the Shyok Suture in the north and Indus Suture in the *** SE base of the terrane is occupied by the stratiform Sapat mafic\|ultramafic complex,which overrides the crust of the Indian plate along the Indus *** complex was intruded into the base of a thick pile of metavolcanics (now amphibolites) of different environments (the Kamila belt).The Kamila amphibolite belt has a vast distribution in southern part of ***,it was considered that the belt occupies the entire southern part of the Kohistan terrane between the main mantle Thrust (mmT) or Indus Suture (IS) in the south and the Chilas Complex in the *** the Indus Valley,the unit was considered to overlie the Jijal Complex which occupies the hanging wall of the *** mapping during this study has revealed that the Kamila amphibolite belt is in direct contact with the mmT only in the extreme eastern (i.e..,Bunar valley) and western parts of the Kohistan *** the area between t he Babusar Pass in the east and the Indus Valley in the west,the belt is separated from the mmT by a basal ultramafic\|mafic layered complex in the hanging wall of the mmT,termed the Sapat *** the north,the belt is bounded by the Chilas Complex which occupies an axial position in the Kohistan *** Kamila amphibolites do not occur as a single,extensive body in the studied area but they occur in three main linear belts (from south to north as Bausar,Jal\|Niat,and Sumal)with small patches and screens within or between plutons of different compositions from diorites to granodiorites,trondhjemites and *** is a thin slice within the Jal\|Niat *** and Jal\|Niat are tholeiitic while Sumal is calc\|alkaline in *** tholeiitic amphibolites are further divided into two:Babusar amphibolites contain low TiO\-2 and very low Zr as compared to the Jal\|*** Jal\|Niat amphibolites show flat patterns with slight increas

关键词： amphibolite Kohistan terrane Pakistan

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Second law analysis of Blasius flow with nonlinear Rosseland thermal radiation in the presence of viscous dissipation

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Propulsion and Power Research 2019年第3期8卷 234-242页

作者： m.I.Afridi m.qasim Department of mathematics COMSATS Institute of Information TechnologyIslamabad45550Pakistan

In the present article,we perform the second law analysis of classical Blasius flow accounting the effects of nonlinear radiation and frictional *** two-dimensional boundary layer momentum and energy equations are converted to self-similar equations using similarity *** set of resultant ordinary differential equations are solved *** numerical results obtained from solutions of dimensionless momentum and energy equations are used to calculate the entropy generation number and Bejan *** velocity profile f'(ξ),temperature distributionθ(ξ),entropy production number Ns and Bejan number Be are plotted against the physical flow parameters and are discussed in ***,for the sake of validation of our numerical code,the obtained results are reproduced using matlab built-in boundary value solver bvp4c resulting in an excellent *** is observed that entropy generation is increasing function of heating parameter,Prandtl number,Eckert number and radiation ***,it is observed that entropy generation can be minimized by reducing the operating temperatureΔT=T_(w)−T_(∞).

关键词： Second law analysis Boundary layer Nonlinear Rosseland thermal radiation Energy dissipation bvp4c

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Dual Solutions of mHD Boundary Layer Flow of a micropolar Fluid with Weak Concentration over a Stretching/Shrinking Sheet

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Communications in Theoretical Physics 2017年第4期67卷 449-457页

作者： Z.H.Khan m.qasim Naeema Ishfaq W.A.Khan Department of mathematics University of MalakandChakdaraDir(Lower)Khyber PakhtunkhwaPakistan Department of mathematics COMSATS Institute of Information TechnologyPark RoadChak ShahzadIslamabadPakistan School of mathematical Sciences Peking UniversityBeijing 100871China Department of mechanical and Industrial Engineering College of Engineering Majmaah UniversityMajmaah 11952Kingdom of Saudi Arabia

We investigate the dual solutions for the mHD flow of micropolar fluid over a stretching/shrinking sheet with heat transfer. Suitable relations transform the partial differential equations into the ordinary differential *** forms solutions are also obtained in terms of confluent hypergeometric function. This is the first attempt to determine the exact solutions for the non-linear equations of mHD micropolar fluid model. It is demonstrated that the microrotation parameter helps in increasing Nusselt number and the dual solutions exist for all fluid flow parameters under consideration. The dual behavior of dimensionless velocity, temperature, microrotation, skin-friction coefficient,local Nusselt number is displayed on graphs and examined.

关键词： mHD micropolar fluid stretching/shrinking sheet exact and dual solutions

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Petrogenesis of the Late Cretaceous Tholeiitic Volcanism and Oceanic Island Arc Affinity of the Chagai Arc, Western Pakistan

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Acta Geologica Sinica(English Edition) 2017年第4期91卷 1248-1263页

作者： Rehanul Haq SIDDIQUI m. qasim jan mohammad Asif KHAN m. Ishaq KAKAR John D. FODEN Baluchistan University of Information Technology Engineering and Management Sciences Quetta Pakistan National Centre of Excellence in Geology University of Peshawar Peshawar & COMSTECH Islamabad Pakistan Karakoram International University Gilgit Pakistan Centre of Excellence in mineralogy University of Baluchistan Quetta Pakistan Department of Earth Sciences University of Adelaide SA 5005 Australia

The Late Cretaceous Chagai arc outcrops in western Pakistan, southern Afghanistan and eastern Iran. It is in the Tethyan convergence zone, formed by northward subduction of the Arabian oceanic plate beneath the Afghan block. The oldest unit of the Chagai arc is the Late Cretaceous Sinjrani Volcanic Group. This is composed of porphyritic lava flows and volcaniclastic rocks, and subordinate shale, sandstone, limestone and chert. The flows are fractionated low-K tholeiitic basalts, basaltic- andesites, and andesites. Relative enrichment in their LILE and depletion in HFSE, and negative Nb and Ta and positive K, Ba and Sr anomalies point to a subduction-related origin. Compared to mORB, the least fractionated Chagai basalts have low Na2O, Fe2O3^T, CaO, Ti, Zr, Y and ^87Sr/^86Sr. Rather than an Andean setting, these results suggest derivation from a highly depleted mantle in an intraoceanic arc formed by Late Cretaceous convergence in the Ceno-Tethys. The segmented subduction zone formed between Gondwana and a collage of small continental blocks （Iran, Afghan, Karakoram, Lhasa and Burma） was accompanied by a chain of oceanic island arcs and suprasubduction ophiolites including Semail, Zagros, Chagai-Raskoh, Kandahar, muslim Bagh, Waziristan and Kohistan-Ladakh, Nidar, Nagaland and manipur. These complexes accreted to the southern margin of Eurasia in the Late Cretaceous.

关键词： Chagai arc tholeiitic volcanics Late Cretaceous western Pakistan

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Parity-check and G-matrix based intelligent early stopping criterion for belief propagation decoder for polar codes

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Digital Communications and Networks 2023年第5期9卷 1148-1156页

作者： qasim jan Shahid Hussain Zhiwen Pan Nan Liu Zakir Ali Zechen Liu Xiaohu You National mobile Communications Research Laboratory Southeast UniversityNanjingJiangsu210096China Purple mountain Laboratories NanjingJiangsu211100China Department of Computer Science COMSATS University IslamabadAttock CampusAttock43600Pakistan School of medicine Computer Science and EngineeringUniversity of GalwayH91 TK33GalwayIreland Department of Computer Sciences Bahria University Lahore Campus54600Pakistan

The error correction performance of Belief Propagation(BP)decoding for polar codes is satisfactory compared with the Successive Cancellation(SC)***,it has to complete a fixed number of iterations,which results in high computational *** necessitates an intelligent identification of successful BP decoding for early termination of the decoding process to avoid unnecessary iterations and minimize the computational complexity of BP *** paper proposes a hybrid technique that combines the“paritycheck”with the“G-matrix”to reduce the computational complexity of BP decoder for polar *** proposed hybrid technique takes advantage of the parity-check to intelligently identify the valid codeword at an early stage and terminate the BP decoding process,which minimizes the overhead of the G-matrix and reduces the computational complexity of BP *** explore a detailed mechanism incorporating the parity bits as outer code and prove that the proposed hybrid technique minimizes the computational complexity while preserving the BP error correction ***,mathematical formulation for the proposed hybrid technique that minimizes the computation cost of the G-matrix is *** performance of the proposed hybrid technique is validated by comparing it with the state-of-the-art early stopping criteria for BP *** results show that the proposed hybrid technique reduces the iterations by about 90%of BP decoding in a high Signal-to-Noise Ratio(SNR)(i.e.,3.5~4 dB),and approaches the error correction performance of G-matrix and conventional BP decoder for polar codes.

关键词： Belief propagation Early termination G-matrix Parity-check Polar codes

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Improved Belief Propagation Decoder for LDPC-CRC-Polar Codes with Bit-Freezing

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China Communications 2024年第7期21卷 135-148页

作者： qasim jan Yin Chao Pan Zhiwen muhammad Furqan Zakir Ali You Xiaohu National mobile Communications Research Laboratory Southeast UniversityNanjing 210096China Purple mountain Laboratories Nanjing 211100China Department of Computer Science National University of Computer and Emerging Sciences Peshawar Campus 25100Pakistan Department of Software Engineering Capital University of Science and Technology(CUST)Islamabad 44000Pakistan Department of Computer Sciences Bahria University Lahore CampusPakistan

Though belief propagation bit-flip(BPBF)decoding improves the error correction performance of polar codes,it uses the exhaustive flips method to achieve the error correction performance of CA-SCL decoding,thus resulting in high decoding complexity and *** alleviate this issue,we incorporate the LDPC-CRC-Polar coding scheme with BPBF and propose an improved belief propagation decoder for LDPC-CRC-Polar codes with bit-freezing(LDPCCRC-Polar codes BPBFz).The proposed LDPCCRC-Polar codes BPBFz employs the LDPC code to ensure the reliability of the flipping set,i.e.,critical set(CS),and dynamically update *** modified CS is further utilized for the identification of error-prone *** proposed LDPC-CRC-Polar codes BPBFz obtains remarkable error correction performance and is comparable to that of the CA-SCL(L=16)decoder under medium-to-high signal-to-noise ratio(SNR)*** gains up to 1.2dB and 0.9dB at a fixed BLER=10-4compared with BP and BPBF(CS-1),*** addition,the proposed LDPC-CRC-Polar codes BPBFz has lower decoding latency compared with CA-SCL and BPBF,i.e.,it is 15 times faster than CA-SCL(L=16)at high SNR regions.

关键词： belief propagation bit-flipping concatenated codes LDPC-CRC-Polar codes polar codes

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Three-dimensional mixed convection flow with variable thermal conductivity and frictional heating

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Communications in Theoretical Physics 2020年第3期72卷 14-20页

作者： m.qasim N Riaz Dianchen Lu S Shafie Department of mathematics Faculty of ScienceJiangsu UniversityZhenjiang 212013China Department of mathematics COMSATS University Islamabad(CUI)455000Park RoadTarlai KalanIslamabad.Pakistan Department of mathematical Sciences Faculty of ScienceUniversiti Teknologi Malaysia81310 UTM Johor BahruJohor 81310Malaysia

In this article,three-dimensional mixed convection flow over an exponentially stretching sheet is *** equation is modelled in the presence of viscous dissipation and variable thermal *** of the sheet is varying exponentially and is chosen in a form that facilitates the similarity transformations to obtain self-similar *** nonlinear ordinary differential equations are solved numerically employing the Runge-Kutta shooting *** order to check the accuracy of the method,these equations are also solved using bvp4c built-in routine in *** solutions are in excellent *** effects of physical parameters on the dimensionless velocity field and temperature are demonstrated through various *** novelty of this analysis is the self-similar solution of the threedimensional boundary layer flow in the presence of mixed convection,viscous dissipation and variable thermal conductivity.

关键词： self-similar equations viscous dissipation mixed convection variable thermal conductivity shooting technique bvp4c matlab

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