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High Voltage 2017年第3期2卷 205-210页

作者： Rahmat Ullah Abdur Rashid Arooj Rashid Faisal Khan Amjad Ali Department of Electrical Engineering CIIT AbbottabadPakistan

In this study,dichlorodifluoromethane(R12)gas and mixtures with nitrogen(N_(2))and air at different pressures and mixing ratios have been investigated and showed good alternative to SF_(6) gas in terms of high-voltage *** gases contain R12 gas,they offer good dielectric properties and possibility to be used in low-temperature *** effects and self-recoverability test have been *** strength under quasi-uniform field showed in the order of SF_(6)>R12>N_(2)>air in alternating current(AC),direct current(DC)and impulse was *** R12/N_(2)(80/20%)could reach over 0.90–0.95 times to that of SF_(6) gas at 50 lb/in^(2) at AC and R12/air(70/30%)gives 0.80–0.90 to SF_(6) gas.R12 gas presents brilliant *** optimal ratio to switch SF_(6) gas is R12/N_(2)(80/20%)and R12/air(70/30%)is based on the authors’experimental condition and setup.

关键词： characteristic mixture mixing

Optimization of moderator assembly for neutron flux measurement:experimental and theoretical approaches

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Nuclear Science and Techniques 2017年第5期28卷 7-12页

作者： Abdul Waheed Nawab Ali Muzahir A.Baloch Aziz A.Qureshi Eid A.Munem Muhammad Usman Rajput Tauseef Jamal Wazir Muhammad Radiation Physics Laboratory Physics DepartmentCOMSATS Institute of Information Technology(CIIT)

A moderator of paraffin wax assembly has been demonstrated where its thickness can be optimized to thermalize fast neutrons. The assembly is used for measuring fast neutron flux of a neutron probe at different neutron energies, using BF03(U10and 200) and3He(U0.500)neutron detectors. The paraffin wax thickness was optimized at 6 cm for the neutron probe which contains an Am–Be neutron source. The experimental data are compared with Monte Carlo simulation results using MCNP5 version 1.4. Neutron flux comparison and neutron activation techniques are used for measuring neutron flux of the neutron probe to validate the optimum paraffin moderator thickness in the assembly. The neutron fluxes are measured at(1.17 ± 0.09) 9 105 and(1.19 ± 0.1) 9 105n/s, being in agreement with the simulated values. The moderator assembly can easily be utilized for essential requirements of neutron flux measurements.

关键词： Am–Be and 252Cf neutron sources BF3&3He detectors Paraffin wax Neutron flux Monte Carlo simulation

Seismic Hazard Assessment of District Mansehra,Khyber Pakhtoonkhawa,Pakistan

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Acta Geologica Sinica(English Edition) 2014年第4期88卷 1157-1168页

作者： MONA Lisa COMSATS Institute of Information Technology(ciit) Islamabad PakistanDepartment of Earth SciencesQuaid-i-Azam University

The site of Mansehra is located seismically in an active regime, known as the Crystalline Nappe Zone and Hazara-Kashmir Syntaxis in NW Himalayas, Pakistan. Seismic Hazard Assessment （SHA） for the site has been carried out by considering the earthquake source zones, selection of appropriate attenuation equations, near fault effects and maximum potential magnitude estimation. The Mansehra Thrust, Oghi Fault, Banna Thrust, Balakot Shear Zone, Main Boundary Thrust, Panjal Thrust, Jhelum Fault and Muzaffarabad Fault and, further to the south, the Sanghargali, Nathiagali, and Thandiani Thrusts are the most critical tectonic features within the 50 km radius of Mansehra. Using the available instrumental seismological data from 1904 to 2007, SHA has been carried out. Other reactivated critical tectonic features in the area have been investigated. Among them the Balakot-Bagh fault, with the fault length of 120 km from Balakot to Poonch, has been considered as the most critical tectonic feature on the basis of geological/structural/seismological data. The potential earthquake of maximum magnitude 7.8 has been assigned to the Balakot-Bagh fault using four regression relations. The peak ground acceleration value of 0.25 g （10% probability of exceedance for 50 years） and 0.5 g has been calculated with the help of the attenuation equation using probabilistic and deterministic approaches.

关键词： Seismic Hazard Assessment Mansehra District NW Himalayas Pakistan Probabilistic and Deterministic Approaches Balakot-Bagh Fault

Crustal structure beneath Tien Shan orogenic belt and its adjacent regions from multi-scale seismic data

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Science China Earth Sciences 2017年第10期60卷 1769-1782页

作者： N.Ghani KHAN BAI Ling ZHAO JunMeng LI GuoHui M.Moklesur RAHMAN CHENG Cheng YANG JianYa Key Laboratory of Continental Collision and Plateau Uplift Institute of Tibetan Plateau ResearchChinese Academy of Sciences Department of Earth Sciences COMSATS Institute of Information Technology (CIIT)

As one of the world's most active intracontinental mountain belts, Tien Shan has posed questions for researchers regarding the formation of different tectonic units and active shallow seismicity. Here, we used a huge data set comprising of 7094 earthquakes from local, regional and teleseismic seismic stations. We used waveform modeling and multi-scale double-difference earthquake relocation technique to better constrain the source parameters of the earthquakes. The new set of events provided us with better initial earthquake locations for further tomographic investigation. We found that reverse-faulting earthquakes dominate the whole study area while the fault plane solutions for earthquakes beneath the northwestern Tarim Basin and the Main Pamir Thrust are diverse. There is a low-velocity anomaly beneath Bashkaingdy at depth of 80 km, and high-velocity anomalies beneath central Tien Shan at shallower depths. These observations are the keys to understand the mechanism of Tien Shan's formation because of Tarim Basin northward and Kazakh Shield's southward subduction in the south and north respectively. Velocities beneath western Tien Shan are relatively high. We thus infer that the Western Tien Shan is relatively less deformed than the eastern Tien Shan primarily due to a relatively brittle mantle.

关键词：地震资料多尺度地壳结构塔里木盆地北部邻区 c带速度异常陆内造山带

SER estimation method for 56 GBaud PAM-4 transmission system

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Chinese Optics Letters 2018年第4期16卷 30-34页

作者： Aadil Raza Kangping Zhong Salman Ghafoor Saeed Iqbal Muhammad Adeel Shahid Habib Muhammad Fasih Uddin Butt Chao Lu COMSATS Institute of Information Technology (ciit) Islamabad Pakistan Department of Electronic and Information Engineering The Hong Kong Polytechnic University Hong Kong China National University of Sciences and Technology (NUST) Islamabad Pakistan

In this Letter, we have proposed a generalized Gaussian probability density function（GGPDF）-based method to estimate the symbol error ratio（SER） for pulse amplitude modulation（PAM-4） in an intensity modulation/direct detection（IM/DD） system. Furthermore, a closed form expression of SERGGDfor PAM-4 has been derived. The performance of the proposed method is evaluated through simulation as well as experimental *** fitting of probability density functions of the received signal is applied via GGPDF and shape parameters P1 and P2 associated with different PAM-4 levels are determined. The optimum single value of shape parameter P is then calculated to estimate the SER. The mathematical relationship of P with different received optical powers and receiver bandwidths has been determined and verified. The proposed method is a fast and accurate method to estimate SER of a PAM-4 system, which is more reliable and in agreement with the error counting method.

关键词： PAM SER estimation method for 56 GBaud PAM-4 transmission system

Identification and genomic analysis of a novel member of Microviridae, IME-16, through high-throughput sequencing

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Virologica Sinica 2015年第4期30卷 301-304页

作者： Peng Shu Azeem Mehmood Butt Zhiqiang Mi Wei Wang Xiaoping An Guangqian Pei Zhiyi Zhang Yong Huang Xianglilan Zhang Taoxing Shi Yigang Tong Anhui Medical University State Key Laboratory of Pathogen and Biosecurity Beijing Institute of Microbiology and Epidemiology Department of Biosciences COMSATS Institute of Information Technology (CIIT)

Dear Editor,Bacteriophages predominate in the biosphere and outnumber their hosts by at least one order of magnitude(Srinivasiah et al.,2008).They have been used for over90 years as an alternative to antibiotics in Eastern Europe(Deresinski,2009).With the increasing emergence of antibiotic resistance,the therapeutic potential of bacteriophages is being reevaluated(Kutter et al.,2010).Until recently,phages possessing ds DNA genomes have

关键词： sequencing throughput genomic antibiotics magnitud

Varying Track Etch Rates along the Fission Fragments＇ Trajectories in CR-39 Detectors

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Chinese Physics Letters 2010年第5期27卷 76-79页

作者： N. All E. U. Khan A. Waheed S. Karim F. Khan A. Majeed DPAM PLEAS P.O. Nilore Islamabad Pakistan P.D PINSTECH P.O. Nilore Islamabad Pakistan International Islamic University Islamabad Pakistan Department of Physics CIIT Islamabad Pakistan

We determine the behavior of track etch rate VT along the tracks in CR-39 detectors exposed to fission fragments from ^252Cf source. CR-39 detectors are etched at 70℃ in different concentrations of Na2COa-mixed 6M NaOH solutions for different etching time intervals of 5-10min starting from 15 min up to 210min. Two values of track etch rate are determined along the fission fragment trajectories. The variation in VT is correlated with the energy loss rate of the fission fragment in the detector material.

关键词： track etch etch rate rate

Efficient Energy Performance within Smart Grid

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Smart Grid and Renewable Energy 2017年第3期8卷 75-86页

作者： Khizer Ayaz Muhammad Sohail Sulemani Naseer Ahmed Department of Electrical Engineering CIIT Abbottabad Pakistan

The Smart Grid, regarded as the next generation power grid, uses two-way flows of electricity and information to create a widely distributed automated energy delivery network. Energy/power plays a critical role for social, economic and industrial development. Because of industrial generalization, especially in agricultural and economical activities, the energy demand has increased rapidly in developed countries. Generation and usage of energy has direct impact on modern power grid. In this scenario energy management is a hard task because load is dynamic and we don’t have control over it. Renewable or undepleted energy resources have great applications and impact in current electric power system situation. For example it gives pollution free (green) energy which is environment and user friendly. It is cost effective;it uses natural resources for its generation and hence do not waste any coal, gas etc. There are many inducements to empower energy productivity. As current smart grid is complex and non linear in operation and design, it used an optimized method that provides maximum efficiency with minimum input. Our work depicts a case study of hybrid electric aircraft for achieving high performance.

关键词： Smart Grid (SG) Demand Response (DR) Renewable Energy Distributed Generators (DG)

Characterization of Drought and Its Assessment over Sindh,Pakistan During 1951-2010

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Journal of Meteorological Research 2015年第5期29卷 837-857页

作者： Shahzada ADNAN Kalim ULLAH 高守亭 Department of Meteorology COMSATS Institute of Information Technology(CIIT) National Drought Monitoring Centre Pakistan Meteorological Department Institute of Atmospheric Physics Chinese Academy of Sciences State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences

Drought is one of the complex meteorological disasters affecting water resources, agriculture, livestock, and socioeconomic patterns of a region. Although drought prediction is difficult, it can be monitored based on climatological information. In this study, we provide high spatiotemporal resolution drought climatology, using observational, gridded precipitation data （0.5°×0.5°） from the Global Precipitation Climatological Center and soil moisture data from the Climate Prediction Center for the 60-yr period 1951-2010. The standardized precipitation index （SPI） based on a fitted Gamma distribution and Run method has been calculated from the regional drought identification model （ReDIM） for 3, 6, 9, 12, and 24 months. The results show strong temporal correlations among anomalies of precipitation, soil moisture, and SPI. Analysis of long-term precipitation data reveals that the drought vulnerability concentrates on monsoon season （July- September）, which contributes 72.4% and 82.1% of the annual precipitation in northern and southern Sindh, respectively. Annual and seasonal analyses show no significant changes in the observed precipitation. The category classification criteria are defined to monitor/forecast drought in the selected area. Further analysis identifies two longest episodes of drought, i.e., 1972 1974 and 2000 2002, while 1969, 1974, 1987, and 2002 are found to be the most severe historical drought years. A drought hazard map of Sindh was developed, in which 10 districts are recognized as highly vulnerable to drought. This study helps to explain the time, duration, intensity, and frequency of meteorological droughts over Sindh as well as its neighboring regions, and provides useful information to disaster management agencies and forecasters for assessing both the regional vulnerabilitv of drought and its seasonal predictability in Pakistan.

关键词： climatology drought standardized precipitation index (SPI) regional drought identification model (ReDIM) Sindh

Mass Transfer： a Deciding Factor for the Multiplicity of an Event in Deep Inelastic Collisions

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Chinese Physics Letters 2006年第10期23卷 2714-2716页

作者： Tabassum Nasir J.J.Baluch E.U.Khan F.N.Khattak M.I.Shahzad Department of Physics Gomal University D.I. Khan Pakistan Department of Physics CIIT Islamabad Pakistan U.W.C. Gomal UniversityD.I.KhanPakistan physics Research Division PINSTECH Islamabad Pakistan

Intermediate stage of the three and four-pronged events is investigated in the reaction ^208Pb＋^197Au at beam energy 11.67 MeV/u. Multiprong events are analysed numerically using an empirical mass-dependent velocityrauge relation. Using the measured three-dimensional coordinates of correlated tracks, it is possible to determine the quantities such as mass transfer and total kinetic energy loss. These quantities are then used to study the intermediate stage of the reaction. It has been observed that mass transfer and total kinetic energy loss at the first step of the reaction decides the multiplicity of an event at the second stage of the sequential fission process.

关键词： HEAVY-ION INTERACTION MICA TRACK DETECTORS CHANNELS FISSION U-238