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Behavioral effects of a four-wing attractor with circuit realization: a cryptographic perspective on immersion

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Communications in Theoretical Physics 2020年第12期72卷 35-70页

作者： Najeeb Alam Khan Muhammad Ali Qureshi Tooba hameed Saeed Akbar Saif Ullah Department of Mathematics University of KarachiKarachi 75270Pakistan Department of Physics University of KarachiKarachi 75270Pakistan Department of Mathematics Government College UniversityLahore 54000Pakistan

In this paper,we propose an innovative chaotic system,combining fractional derivative and sinehyperbolic nonlinearity with circuit *** study of this system is conducted via an analog circuit simulator,using two anti-parallel semiconductor diodes to provide hyperbolic sine nonlinearity,and to function as operational *** multi-stability of the system is also enhanced with the help of multi-equilibrium points for distinct real orders of *** system explores the generation of a four-wing attractor in different phases,both numerically and *** changing the input parameters of the system,different graphs are generated for current flow in state,phase,and space,to confirm the precision of the fractional order derivatives.A reasonable simulation shows that the deliberate circuit provides effective chaos in terms of speed and accuracy,which is comensurate with the numerical *** nonlinear chaotic behavior is utilized to encrypt sound(.wav),images(.jpg),and animated(.gif)data which are a major requirement for the security of communication *** proposed circuit performs chaos and cryptographic tasks with high-effective analog computation,and constitutes a novel approach to this area of research.

关键词： multi-wing attractors hyperbolic sine circuit realization encryption

Pulse width modulation voltage source deadtime effect on partial discharge and lifetime of inverter‐fed motor insulation

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High Voltage 2022年第6期7卷 1185-1193页

作者： Shakeel Akram Peng Wang Pengfei Meng Gian Carlo Montanari Farhan hameed Malik College of Electrical Engineering Sichuan UniversityChengduChina Center for Advanced Power Systems Florida State UniversityTallahasseeFloridaUSA Department of Electromechanical Engineering Abu Dhabi PolytechnicAbu DhabiUnited Arab Emirates

This paper analyses the impact of square wave pulse voltage deadtime on the partial discharge(PD)and the lifetime of turn-to-turn insulation.A bipolar repetitive pulse voltage with a deadtime of 0–10μs is produced using double half-bridge solid-state switches having push–pull technology controlled by a field-programmable gate *** mechanism of the discharge process at rising and falling edges of the pulse voltage before and after deadtime is analysed in *** discharge amplitude and PD probability at the rising/falling edges of the voltage waveform increase as the deadtime increases from 0 to 10μs due to the remanent *** number of PD and their intensity is higher at the first rising/falling edges of pulse voltage as compared to the second rising/falling edges for all deadtimes 0–10μ*** the deadtime increases beyond 2μs,the number of PDs increases and concentrates at a specific phase angle of rising/falling *** localise discharges degrade the insulation material and reduce its *** study helps to identify the inverter-fed motor insulation faults due to *** can provide guidelines to motor insulation designers to determine the limit value of deadtime to compensate PD and ensure the safer operation of such motors.

关键词： dead insulation inverter

Utilization of iron oxide bearing pellets waste for preparing hard and soft ferromagnetic glass ceramics

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Journal of Advanced Ceramics 2014年第4期3卷 259-268页

作者： Salwa A.M.ABDEL-hameed Ibrahim M.HAMED Nehal A.ERFAN Glass Research Department National Research CenterDokkiCairoEgypt Chemical Engineering Department Faculty of EngineeringMinia UniversityMiniaEgyp

About 8%of the imported iron oxide pellets burdens to Egypt are *** this paper,broken pellets waste(BPW)is used as raw material for the preparation of hard magnetic glass ceramics(HMGC)as well as soft magnetic glass ceramics(SMGC).About 54 wt%and 37 wt%of BPW are used to prepare SMGC and HMGC,*** thermal analysis(DTA)reveals two broad exothermic peaks for HMGC at 591℃and 697℃,whereas one exothermic peak at 820℃is detected for SMGC.X-ray diffraction(XRD)shows the crystallization of hematite as the sol phase in BPW,and meanwhile,Zn-ferrite and Ba-hexaferrite are identified in SMGC and HMGC,*** electron microscopy(TEM)reveals the crystallization of nanosize particles of~20 nm for SMGC and~12 nm for *** scanning magnetometer(VSM)reveals an increase in saturation magnetization from~1 emu/g for BPW to~77 emu/g for SMGC and 21 emu/g for HMGC.

关键词： magnetic materials nanostructure pellets waste

Tectonic Study of the Sub-Himalayas Based on Geophysical Data in Azad Jammu and Kashmir and Northern Pakistan

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Journal of Earth Science 2016年第6期27卷 981-988页

作者： Muhammad Rustam Khan Fahad hameed Muhammad Saleem Mughal Muhammad Basharat Sohail Mustafa Institute of Geology University of Azad Jammu and Kashmir Muzaffarabad

The tectonic study based on geophysical data has been carried out in Sub-Himalayas in Azad Jammu and Kashmir and northern Pakistan. A series of thin skinned and thick skinned faults have been delineated in the investigated area on the basis of present study. In the study area compressional stresses caused by the collisional of Indian and Eurasian plates developed the northwestsoutheast trending faults which are Shaheed Gala thrust, Bagh basement fault, Kashmir boundary thrust and Kawai fault or Indus Kohistan seismic zone. The crustal thickness increases towards north due to the stacking of the thrust sheets along these faults. The Murree Formation thrusts over the Si- waliks molasse along the Shaheed Gala thrust. This fault dips at an angle of 43° northeast and joins the thick skinned Bagh basement fault in subsurface which are penetrated up to Moho depth. In the northeast of Bagh basement fault the northwest-southeast trending Kashmir boundary thrust has been delineated in the sedimentary-metasedimentary wedge which joins the Indus Kohistan seismic zone in the subsurface. The present study suggested that the Kawai fault which is running within Murree Formation cuts 16 km thick sedimentary-metasedimentary wedge and also joins the Indus Kohistan seismic zone in the subsurface.

关键词： tectonic study Sub-Himalayas Bouguer anomaly magnetic anomaly gravity modeling.

Counter-current three-phase fluidization in a turbulent contact absorber： A CFD simulation

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Particuology 2017年第6期15卷 51-67页

作者： Syed Shah Jehan Gillani Atta Ullah Muhammad Zaman Imran Rafique Chugtai Mansoor hameed Inayat Department of Chemical Engineering Pakistan Institute of Engineering and Applied Sciences (PIEAS) 45650 Islamabad. Pakistan

A computational fluid dynamics study of three-phase counter-current fluidization occurring in a turbu- lent contact absorber was performed. A two-dimensional, transient Eulerian multi-fluid model was used, in which the dispersed solid phase was modeled employing a kinetic theory of granular flow. The grid independence of the model, the effect of wall boundary conditions, the choice of granular temperature model, the effects of order of discretization scheme and drag models were studied for a base case setting, The results of simulations were validated against experimental results obtained from the literature. Once the model settings were finalized, simulations were performed for different gas and liquid velocities to predict the hydrodynamics of the absorber. Computed bed expansion and pressure drop were compared with experimental data. Good agreement between the two was found for low velocities of gas and liquid.

关键词： Multiphase Counter-current Computational fluid dynamics (CFD) Fluidization Turbulent contact absorber

Cotton Leaf Curl Virus： Ionic Status of Leaves and Symptom Development

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Journal of Integrative Plant Biology 2006年第5期48卷 558-562页

作者： Naeem lqbal Muhammad Yasin Ashraf Farrukh Javed Muhammad Ashmf Sohail hameed Department of Botany University of Agriculture Faisalabad Pakistan Nuclear Institute for Agriculture and Biology Faisalabad Pakistan National Institute for Biotechnology and Genetic Engineering Faisalabad Pakistan

In the present study, the relationship between the nutritional status of leaves and the development of symptoms of cotton leaf curl virus （CLCuV） in two cotton （Gossypium hirsutum L.） cuItlvars （I.e. CIM-240 and S-12） was Investigated. The incidence of disease attack was found to be 100% In the S-12 cuItlvar and 16% in the CIM-240 cuItivar. Geminivirus particles in infected leaves were confirmed by transmission electron microscope examination of highly specific geminivirus coat protein antlsera-treated cell sap. The CLCuV Impaired the accumulation of different nutrients in both cuItivars. A marked decrease in the accumulation of Ca^2＋ and K^＋ was observed in infected leaves. However, the disease had no effect on leaf concentrations of Na^＋, N, and P. It was observed that the curling of leaf margins in CLCuV-Infected plants was associated with the leaf Ca^2＋ content; leaf curling was severe in plants with a significant reduction In Ca^2＋ content. Moreover, leaf K＆＋ content was found to be associated with resistance/susceptibility to CLCuV infection.

关键词： geminiviruses Gossypium hirsutum leaf curling nutrient accumulation.

Cultural characteristics of chromium resistant unicellular cyanobacteria isolated from local environment in Pakistan

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Chinese Journal of Oceanology and Limnology 2005年第4期23卷 433-441页

作者： Abdul hameed Shahida Hasnain Department of Botany University of the Punjab Quaid-e-Azam Campus Lahore-54590 Pakistan

Many unicellular cyanobacteria were isolated from different places： fields, ponds, polluted water, and soils from Muredkey and Kasur tannery areas, near Lahore, Pakistan. Different media like BG 11 medium, Bold Basal medium, Chu＇s # 10 medium and Gotham＇s medium, in standard forms and with slight variations of ingredients, and different pH, temperature and light regimes were checked for the optimum growth of the isolates. The isolation pro- cedure was repeated with different concentrations of chromium to select the resistant strains. These selected strains grew on chromium of the range 100-200 μg/ml in BG 11 medium. Cyanobacteria were maintained in solid and liquid media with/without shaking. Cyanobacterial strains were collected from natural habitats that were accompanied by a diversified group of organisms including bacteria, protozoan, and rotifers etc. In order to eliminate these agents termed as contaminants, we used several methods including phenol treatment, use of antibiotic and careful manual picking of unicellular cyanobacteria. Resistance of these strains against different heavy metals （ZnSO4, MnSO4, NiSO4, COCl2, Pb（NO3）3, CuSO4, HgCl2, AgNO3 and CdCl2） and antibiotics （erythromycin, streptomycin, kanamycin, chloramphenicol, neomycin） was evaluated. Optimum temperature was 30℃ with variable pH for the reduction of Cr^6＋ in to Cr^3＋ in majority of strains.

关键词： cyanobacteria Cr^6+ reduction heavy metals

Experimental investigation of a cook-off temperature in a hot barrel

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Defence Technology（防务技术） 2014年第2期10卷 86-91页

作者： Amer hameed Mathew AZAVEDO Philip PITCHER Centre for Defence Engineering Cranfield UniversityDefence Academy of the United Kingdom Cranfield University Defence Academy of the United Kingdom

The experimental investigations of the effect of contact time/temperature on initiating the cook-off using 7.62 mm calibre cartridge cases(CC) were conducted *** cartridges were hlled with commercial off-the-shelf(COTS) double based(DB) propellant(Bulls Eye)and were loaded in a hot *** thermal explosion temperature is of great significance to both weapon designers and safety inspectors as it provides the operational limit and safe operating *** CC under test,it was found that the cook-off temperatures of this propellant were encountered with the heat transfer profile of the simulated gun barrel between 151.4 ℃ and 153.4 ℃,with a reaction occurring in less than300 s after the round was ***,each experiment was found to be consistent and repeatable.

关键词：工作温度实验厨师接触时间 COTS 推进剂设计师检查员

Experimental and simulation optimization analysis of the Whipple shields against shaped charge

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Acta Mechanica Sinica 2012年第3期28卷 877-884页

作者： G.Hussain A.hameed I.Horsfall P.Barton A.Q.Malik School of Chemical&Materials Engineering(SCME) National University of Sciences&Technology(NUST)IslamabadPakistan Centre for Defence Engineering Department of Engineering and Applied Science(DEAS)Cranfield UniversityShrivenhamSwindonSN68LAUK

Occasionally, the Whipple shields are used for the protection of a space station and a satellite against the meteoroids and orbital debris. In the Whipple shields each layer of the shield depletes part of high speed projectile en- ergy either by breaking the projectile or absorbing its energy. Similarly, this investigation uses the Whipple shields against the shaped charge to protect the light armour such as infantry fighting vehicles with a little modification in their design. The unsteady multiple interactions of shaped charge jet with the Whipple shield package against the steady homogeneous target is scrutinized to optimize the shield thickness. Sim- ulations indicate that the shield thickness of 0.75 mm offers an optimum configuration against the shaped charge. Exper- iments also support this evidence.

关键词： Whipple shield Mass efficiency - Space effi-ciency Erosion. Pressure