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Experimental Study on Heat Storage Properties Comparison of Paraffin/metal Foams Phase Change material Composites

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Journal of Thermal Science 2024年第2期33卷 469-478页

作者： Waqar AHmED Abid HUSSAIN Hanzla shahid Imran ALI Hafiz muhammad ALI Department of mechanical Engineering University of Engineering and TechnologyTaxila47080Pakistan Department of mechanical Engineering Institute of Space TechnologyIslamabadPakistan Department of mechanical Mechatronics and Manufacturing EngineeringUniversity of Engineering and Technology LahoreFaisalabad CampusPunjabPakistan mechanical Engineering Department King Fahd University of Petroleum and MineralsDhahran31261Saudi Arabia Interdisciplinary Research Center for Renewable Energy and Power Systems(IRC-REPS) King Fahd University of Petroleum and MineralsDhahran31261Saudi Arabia

Heat storage properties of phase change materials(PCms) are essential characteristics that perform a key role in thermal heat energy storage *** thermal properties of PCms can be improved by developing metal foam/PCm *** addition of metal foam in PCms has a significant effect on the thermal characteristics of *** this paper,the heat storage properties of two different metal foam/PCm composites were experimentally *** behavior of paraffin in metal foam(copper and iron-nickel)/paraffin composites concerning pure paraffin at a constant heat flux of 1000 W/m^(2) in three directions simultaneously(x,y,and z) was *** was infiltrated into copper and iron-nickel foams to develop composite materials which resulted in enhancing the thermal conductivity of the paraffin.A comparative analysis is made on the heat storage properties of paraffin in copper and iron-nickel foams/paraffin *** temperature distribution during the phase transition process is experimentally *** comparison indicates that temperature uniformity in copper foam/paraffin composite is better than in iron-nickel foam/paraffin composite and pure paraffin at the same heat *** results show that at heat flux of 1000 W/m^(2),the heat storage time for copper foam/paraffin composite is 20.63% of that of iron-nickel foam/paraffin composite.

关键词： heat storage capacity paraffin/metal foam composite temperature uniformity heat storage rate phase transition process

Geotechnical behavior of uranium mill tailings from Saskatchewan,Canada

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International Journal of mining Science and Technology 2016年第3期26卷 369-375页

作者： Bhuiyan Imteaz Azam shahid Khaled Shifullah Landine Patrick Environmental Systems Engineering University of Regina Thurber Engineering Limited Cameco Corporation

This paper investigates the geotechnical behavior of uranium mill tailings from Saskatchewan, *** 4% tailings were well-graded with 29% fines whereas the 5% and 6% tailings were gap-graded with 49% fines. All samples exhibited a negligible strength(0.4 k Pa) up to 60% solids, followed by a rapid increase. The 4% tailings exhibited a lower rate and amount of settlement than 5% and 6% tailings. The kidecreased from 10^(-2)to 10^(-4)m/s with a decrease in eifrom 16 to 4 and a decrease in ef from 8 to 4 such that 4% tailings showed one order of magnitude lower values than the 5% and 6%tailings. The settling potential decreased ten times(50%–5%) for 4% tailings and four times(60%–15%)for 5% and 6% tailings. The effective stress increased from 80 to 260 Pa in the settling tests. The 4%tailings were less prone to segregation when compared with 5% and 6% tailings. The average solids content after settling was 35% for 4% tailings, 40% for 5% tailings and 39% for 6% tailings with a solids content deviation of ±3%, ±8%, ±6%, respectively. All materials were essentially non-segregating at 40%initial solids.

关键词： Uranium mill tailings Rheology Settling Segregation

Composition,Structure and Regeneration Dynamics of Olea ferruginea Royle Forests from Hindukush Range of Pakistan

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Journal of mountain Science 2015年第3期12卷 647-658页

作者： NASRULLAH Khan FAYAZ Ali KISHWAR Ali shahid Shaukat Laboratory of Plant Ecology Department of Botany University of malakand Department of Plant Sciences School of Biological SciencesUniversity of Reading Institute of Environmental Studies University of Karachi

Abstract＂ The abundance of Olea ferruginea in malakand Division has been significantly reduced across its distribution range due to anthropogenic pressure in the recent past. A number of initiatives were taken for grafting this species to obtain better seeds for oil production, without the basic information on their ecology and management. To address this knowledge gap, we quantified the composition, structure and regeneration dynamics of Olea ferruginea forests in malakand Division, Hindukush range of Pakistan. In the present study, five communities dominated by Oleaferruginea were identified using Ward＇s agglomerative cluster analysis. Total tree density ranged from 153-26o2 plants/ha, and basal area from 19.55 to 2353 m~ ha-1 with Olea having a relative density of 51% to 87% and basal area of 48% to 93%, respectively. The density of juveniles of the dominant and subordinate tree species were generally low which reflect their narrow distribution in the study area. Size-class distributions of O. ferruginea disclosed a bell-shaped pattern, indicating that forests were heavily exploited by local inhabitants in previous periods and recently by armed forces owing to security risks in the study area. The age （mean max. 300±34 years） and annual increment （3.2±1.2 years/cm） indicates that the species is long lived and generally slow growing among the different broad leaved species studied so far. However, the oldest trees can be found by the exploration of large diameter trees in the area. In addition, we found a stable linear relationship between the age and diameter （r2 = o.779）, indicating that diameter is a good predictor of age for this broad leaved species. In view of its relatively slow growth, longevity and positive ring-width characteristics O. ferruginea seems to be a suitable choice for dendroecological and dendrochronological studies in lesser Himalayan and Hindukush ranges of Pakistan. The results obtained from this study may help in understanding the composi

关键词： Oleaferruginea Species composition Ward's agglomerative cluster analysis Seedling Dendroecology

Comprehensive spectral analysis of Cyg X-1 using RXTE data

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Research in Astronomy and Astrophysics 2012年第10期12卷 1427-1438页

作者： Rizwan shahid Ranjeev misra S.N.A.Jaaffrey Department of Physics M.L.Sukhadia UniversityUdaipur-313001India Inter University Centre for Astronomy and Astrophysics Pune-411007India

We analyze a large number （〉 500） of pointed Rossi X-Ray Timing Explorer （RXTE） observations of Cyg X- 1 and model the spectrum of each one. A subset of the observations for which there is a simultaneous reliable measure of the hardness ratio by the All Sky monitor shows that the sample covers nearly all the spectral shapes of Cyg X-1. Each observation is fitted with a generic empirical model consisting of a disk black body spectrum, a Comptonized component whose input photon shape is the same as the disk emission, a Gaussian to represent the iron line and a reflection feature. The relative strength, width of the iron line and the reflection parameter are in general correlated with the high energy photon spectral index F. This is broadly consistent with a geometry where for the hard state （low F ~ 1.7） there is a hot in- ner Comptonizing region surrounded by a truncated cold disk. The inner edge of the disk moves inwards as the source becomes softer till finally in the soft state （high F 〉 2.2） the disk fills the inner region and active regions above the disk produce the Comptonized component. However, the reflection parameter shows non-monotonic behavior near the transition region （F ~ 2）, which suggests a more complex geometry or physical state of the reflector. In addition, the inner disk temperature, during the hard state, is on average higher than in the soft one, albeit with large scatter. These inconsistencies could be due to limitations in the data and the empirical model used to fit them. The flux of each spectral component is well correlated with F, which shows that unlike some other black hole systems, Cyg X- 1 does not show any hysteresis be- havior. In the soft state, the flux of the Comptonized component is always similar to the disk one, which confirms that the ultra-soft state （seen in other brighter black hole systems） is not exhibited by Cyg X-1. The rapid variation of the Compton amplifica- tion factor with F naturally explains the absence of spec

关键词： accretion accretion disks -- X-rays: binaries

Structural and magnetic Properties of Chemically Synthesized Pd-modified NiFe2O4 Nanoparticles

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Chinese Journal of Chemical Physics 2016年第2期29卷 245-248,I0002页

作者： shahid Aatiq shahid m. Ramay Asif mahmood SairaRiaza shahzad Naseem 巴基斯坦旁遮普邦大学固体物理卓越中心拉合尔100190 沙特阿拉伯沙特国王大学理学院物理与天文学系利雅得11421 沙特阿拉伯沙特国王大学工程学院化学工程系利雅得11421

magnetic nanoparticles of NiFe2O4-Pd composites have been synthesized using a simple, low cost, sol-gel auto-combustion method. As-prepared samples were sintered at 800℃ for 6 h in order to develop the crystalline phase. X-ray diffraction confirmed the spinel structure of the ferrite samples. Structural morphology and size of the nanoparticles were evaluated using a field emission scanning electron microscope. magnetic hysteresis loops were obtained at 300 and 100 K using a physical properties measurement system. The value of saturation magnetization was observed to decrease at the temperatures with the increase of Pd contents up to 5% but then a sudden rise in saturation magnetization was observed for the addition of 10% Pd in NiFe2O4.

关键词： magnetic nanoparticles Sol-gel auto-combustion Low temperature magneticproperty

Examining the Quality metrics of a Communication Network with Distributed Software-Defined Networking Architecture

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Computer modeling in Engineering & Sciences 2024年第11期141卷 1673-1708页

作者： Khawaja Tahir mehmood shahid Atiq Intisar Ali Sajjad muhammad majid Hussain malik m.Abdul Basit Department of Electrical Engineering Khwaja Fareed University of Engineering and Information TechnologyRahim Yar Khan64200Pakistan Department of Telecommunication Systems Bahauddin Zakariya UniversityMultan60000Pakistan Department of Electrical Engineering University of Engineering and TechnologyTaxila47050Pakistan School of Engineering and Physical Sciences Heriot-Watt UniversityEdinburghEH144ASUK

Software-Defined Networking(SDN),with segregated data and control planes,provides faster data routing,stability,and enhanced quality metrics,such as throughput(Th),maximum available bandwidth(Bd(max)),data transfer(DTransfer),and reduction in end-to-end delay(D(E-E)).This paper explores the critical work of deploying SDN in large-scale Data Center Networks(DCNs)to enhance its Quality of Service(QoS)parameters,using logically distributed control *** is a noticeable increase in Delay(E-E)when adopting SDN with a unified(single)control structure in big DCNs to handle Hypertext Transfer Protocol(HTTP)requests causing a reduction in network quality parameters(Bd(max),Th,DTransfer,D(E-E),etc.).This article examines the network performance in terms of quality matrices(bandwidth,throughput,data transfer,etc.),by establishing a large-scale SDN-based virtual network in the mininet *** SDN network is simulated in three stages:(1)An SDN network with unitary controller-POX to manage the data traffic flow of the network without the server load management algorithm.(2)An SDN network with only one controller to manage the data traffic flow of the network with a server load management algorithm.(3)Deployment of SDN in proposed control arrangement(logically distributed controlled framework)with multiple controllers managing data traffic flow under the proposed Intelligent Sensing Server Load management(ISSLm)*** a result of this approach,the network quality parameters in large-scale networks are enhanced.

关键词： Software defined networking quality of service hypertext transfer protocol data transfer rate latency maximum available bandwidth server load management

Extension of Direct Citation model Using In-Text Citations

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Computers, materials & Continua 2021年第3期66卷 3121-3138页

作者： Abdul shahid muhammad Tanvir Afzal muhammad Qaiser Saleem m.S.Elsayed Idrees majzoob K.Omer Institute of Computing Kohat University of Science and TechnologyKohat26000Pakistan Department of Computer Science NAMAL InstituteMianwali42250Pakistan College of Computer Science and Information Technology Albaha UniversityAl BahaSaudi Arabia

Citations based relevant research paper recommendations can be generated primarily with the assistance of three citation models:(1)Bibliographic Coupling,(2)Co-Citation,and(3)Direct *** of new scholarly articles are published every *** flux of scientific information has made it a challenging task to devise techniques that could help researchers to find the most relevant research papers for the paper at *** this study,we have deployed an in-text citation analysis that extends the Direct Citation model to discover the nature of the relationship degree-ofrelevancy among scientific *** this purpose,the relationship between citing and cited articles is categorized into three categories:weak,medium,and *** an experiment,around 5,000 research papers were crawled from the *** research papers were parsed for the identification of in-text citation ***,0.1 million references of those articles were extracted,and their in-text citation frequencies were computed.A comprehensive benchmark dataset was established based on the user ***,the results were validated with the help of Least Square Approximation by Quadratic Polynomial *** was found that degreeof-relevancy between scientific papers is a quadratic increasing/decreasing polynomial with respect to-increase/decrease in the in-text citation frequencies of a cited ***,the results of the proposed model were compared with state-of-the-art techniques by utilizing a well-known measure,known as the normalized Discount Cumulative Gain(nDCG).The proposed method received an nDCG score of 0.89,whereas the state-of-the-art models such as the Content,Bibliographic-coupling,and metadata-based models were able to acquire the nDCG values of 0.65,0.54,and 0.51 *** results indicate that the proposed mechanism may be applied in future information retrieval systems for better results.

关键词： Direct citation model in-text citations frequencies normalized discount cumulative gain least square approximation

In vivo immunomodulatory profile of histamine receptors(H1,H2,H3 and H4):a comparative antagonists study

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Asian Pacific Journal of Tropical medicine 2010年第6期3卷 465-470页

作者： Trivendra Tripathi mohammad shahid Haris m Khan Aijaz Ahmed Khan mashiatullah Siddiqui Rahat Ali Khan Department of Biochemistry Faculty of MedicineJawaharlal Nehru Medical College & HospitalAligarh Muslim UniversityAligarh-202002U.P.India Department of microbiology Faculty of MedicineJawaharlal Nehru Medical College & HospitalAligarh Muslim UniversityAligarh-202002U.P.India Department of Anatomy Faculty of MedicineJawaharlal Nehru Medical College & HospitalAligarh Muslim UniversityAligarh-202002U.P.India Department of Pharmacology Faculty of MedicineJawaharlal Nehru Medical College & HospitalAligarh Muslim UniversityAligarh-202002U.P.India

Objective:To delineate the comparative immunomodulatory roles of H1R-H4R in antibody generation profile in rabbit ***:The cohort comprised of eight groups containing 18(9 male and 9 female) rabbits in each ***Ⅰremained non-immunized and received only vehicle(sterile distilled water,1 mL/kg×b.i.d.) ***Ⅱreceived vehicle (1 mL/kg×b.i.d.) while GroupsⅢ-Ⅶ(drugs-treated) received subcutaneous histamine (100μg/kg×b.i.d.),and intramuscular H1R-antagonist(pheniramine,10 mg/kg×b.i.d.), H2R-antagonist(ranitidine,10 mg/kg×b.i.d.),H3R-antagonist(iodophenpropit,1μg/kg×b.i.d.) and H4R-antagonist(JNJ 7777120,10μg/kg×b.i.d.),and GroupⅧDmSO(1 mL/kg×b.i.d.),respectively for 10 days(starting from day 1).They were subsequendy immunized with intravenous injection of sheep red blood cells(SRBC) at day *** estimation of serum Igs,Igm and IgG were done by ELISA,and observed at day 0(pre-immunization),and 7,14,21,28 and 58(post-immunization).Results:It was shown that histamine and HRs-antagonists could influence a detectable antibody response to SRBC as early as day 7-post-immunization(post-Ⅰ), which lasted until day 58 post-Ⅰ.The results were found statistically significant(Pmine receptors play important roles in modulation of antibody generation in which H1R,H2R and H4R have immunosuppressive roles and conversely, H3R playes an immune enhancing *** findings of this study may have clinical significance and provide the baseline information for future study.

关键词： Histamine receptors Immunomodulation Humoral immune response H3R-antagonist H4R-antagonist

Land use/land cover classification and its change detection using multi-temporal mODIS NDVI data

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Journal of Geographical Sciences 2015年第12期25卷 1479-1506页

作者： m USmAN R LIEDLI m A shahid A ABBAS Institute for Groundwater management TU Dresden 01069 Dresden Germany University of Agriculture Faisalabad Pakistan Leibniz Centre for Agricultural Landscape Research (ZALF) Eberswalder Str. 84 15374 Mencheberg Germany

Detailed analysis of Land Use/Land Cover （LULC） using remote sensing data in complex irrigated basins provides complete profile for better water resource management and planning. Using remote sensing data, this study provides detailed land use maps of the Lower Chenab Canal irrigated region of Pakistan from 2005 to 2012 for LULC change detection. major crop types are demarcated by identifying temporal profiles of NDVI using mODIS 250 m × 250 m spatial resolution data. Wheat and rice are found to be major crops in rabi and kharif seasons, respectively. Accuracy assessment of prepared maps is performed using three dif- ferent techniques： error matrix approach, comparison with ancillary data and with previous study. Producer and user accuracies for each class are calculated along with kappa coeffi- cients （K）. The average overall accuracies for rabi and kharif are 82.83% and 78.21%, re- spectively. Producer and user accuracies for individual class range respectively between 72.5% to 77% and 70.1% to 84.3% for rabi and 76.6% to 90.2% and 72% to 84.7% for kharif. The K values range between 0.66 to 0.77 for rabi with average of 0.73, and from 0.69 to 0.74 with average of 0.71 for kharif. LULC change detection indicates that wheat and rice have less volatility of change in comparison with both rabi and kharif fodders. Transformation be- tween cotton and rice is less common due to their completely different cropping conditions. Results of spatial and temporal LULC distributions and their seasonal variations provide useful insights for establishing realistic LULC scenarios for hydrological studies.

关键词： land use/land cover remote sensing normalized difference vegetation index accuracy assessment change detection hydrological modeling