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Characterization of polycyclic aromatic hydrocarbon emissions from diesel engine retrofitted with selective catalytic reduction and continuously regenerating trap

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Journal of Environmental Sciences 2012年第8期24卷 1449-1456页

作者： asad Naeem Shah Yunshan Ge Jianwei Tan Zhihua Liu Chao He Tao Zeng National Lab of Auto Performance and Emission Test School of Mechanical and Vehicular EngineeringBeijing Institute of TechnologyBeijing 100081China Department of Mechanical Engineering University of Engineering and TechnologyLahore 54000Pakistan

Two after treatment units, selective catalytic reduction （SCR） and continuously regenerating trap （CRT）, were independently retrofitted to a diesel engine, with the objective to investigate their impact on the conversion/reduction （CR） of polycyclic aromatic hydrocarbons （PAHs）. The experiments were conducted under the European steady state cycle （ESC） first without any retrofits to get baseline emissions, and then with SCR and CRT respectively, on the same engine. The particulate matter （PM）-phase PAHs were trapped in fiberglass filters, whereas gas-phase PAHs were collected in cartridges, and then analyzed using a gas chromatograph-mass spectrometer （GC-MS）. Both PM-phase and gas-phase PAHs were greatly reduced with CRT showing respective CR of 90.7% and above 80%, whereas only gas-phase PAHs were abated in the case of SCR, with CR of above 75%. Lower molecular weight （LMW） PAHs were in abundance, while naphthalene exhibited a maximum relative contribution （RC） to LMW-PAHs for all three cases. Further, the CR of naphthalene and anthracene were increased with increasing catalyst temperature of SCR, most likely due to their conversion to solid particles. Moreover, the Benzo[a]Pyrene equivalent （BaPeq） of PAHs was greatly reduced with CRT, owing to substantial reduction of total PAHs.

关键词： diesel engine continuously regenerating trap urea-selective catalytic reduction polycyclic aromatic hydrocarbons unregulated emissions

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Phase analysis of AlFe2B2 by synchrotron X-ray diffraction,magnetic and M?ssbauer studies

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Progress in Natural Science:Materials International 2017年第2期27卷 251-256页

作者： Tahir Ali M.N.Khan E.Ahmed asad Ali Physics Division Pakistan Institute of Nuclear Science and technology Department of Physics Abdul Wali Khan University PINSAT Preston University

The structural and magnetic properties of essentially phase pure AlFe2B2prepared by arc melting were compared with a sample containing impurities. Analysis was carried out by means of synchrotron X-ray diffraction, magnetic measurements and M?ssbauer spectroscopy. The analysis of synchrotron X-ray diffraction data confirmed the orthorhombic structure of space group Cmmm for AlFe2B2with Al13Fe4as main impurity phase. The magnetic measurements revealed an unsaturated ferromagnetic state in AlFe2B2with a transition temperature（Tc） of 286 K. Isothermal magnetization measurment at 5 K gave a saturation magnetization of 0.7 μB per Fe atom while Arrott plots establish the second order nature of ferromagnetic transition. The thermal evolution of M?ssbauer spectra confirmed the ferromagnetic nature of this material revealing an hyperfine field of 73 kOe and an isomer shift of 0.46 mm/s at 100 K. The M?ssbauer spectra of a phase pure sample was compared with the one containing impurity phases. It is suggested that the low temperature paramagnetic contribution in M?ssbauer spectra of phase pure material may have its origin in some intrinsic phenomena arising from defects or inhomogeneities in crystal structure.

关键词： AlFe2B2 Synchrotron X-ray diffraction Ferromagnetism Mossbauer effect spectroscopy

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Developing Engagement in the Learning Management System Supported by Learning Analytics

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Computer Systems Science & Engineering 2022年第7期42卷 335-350页

作者： Suraya Hamid Shahrul Nizam Ismail Muzaffar Hamzah asad W.Malik Department of Information System Faculty of Computer Science and Information TechnologyUniversiti MalayaKuala LumpurMalaysia Faculty of Computing and Informatics Universiti Malaysia SabahSabahMalaysia Department of Computing School of Electrical Engineering and Computer Science(SEECS)National University of Sciences and Technology(NUST)IslamabadPakistan

Learning analytics is an emerging technique of analysing student par-ticipation and *** recent COVID-19 pandemic has signiﬁcantly increased the role of learning management systems(LMSs).LMSs previously only complemented face-to-face teaching,something which has not been possible between 2019 to *** date,the existing body of literature on LMSs has not analysed learning in the context of the pandemic,where an LMS serves as the only interface between students and ***,productive results will remain elusive if the key factors that contribute towards engaging students in learning are notﬁrst identiﬁ***,this study aimed to perform an exten-sive literature review with which to design and develop a student engagement model for holistic involvement in an *** required data was collected from an LMS that is currently utilised by a local Malaysian *** model was validated by a panel of experts as well as discussions with *** is our hope that the result of this study will help other institutions of higher learning determine factors of low engagement in their respective LMSs.

关键词： Engagement analysis learning analytics learning management system student engagement

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A Dynamic VANET Architecture with Efficient Privacy-Preserving Authentication Protocol

A Dynamic VANET Architecture with Efficient Privacy-Preservi...

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作者： Syed asad Shah 上海交通大学

学位级别：硕士

During communication in Intelligent Transportation Systems（ITS）,vehicle broadcast both critical and non-critical messages to avoid fatal road crashes and hazardous road traffic *** messages in an open-access environment raise security and privacy issues as VANET does not override all solutions of MANET due to its unique features like low volatility and high *** in VANET is a challenging and critical issue,receive the attention of all automobile *** this thesis,we propose a dynamic VANET architecture with an efficient privacy-preserving authentication *** introduce a novel idea of region topology to ensure the communication between vehicles using the social *** symmetric cryptographi c protocols are short in size and have high throughput but did not provide *** cryptographic based protocols are computationally expensive and cause storage *** protocol is a hybrid combination of symmetric advanced encryp tion standard（AES）and asymmetric elliptic curve cryptography（ECC）to preserve the privacy of the vehicle and secure the communication against different security *** simulation results and performance evaluation shows our protocol outperforms ot her protocols and schemes by reducing communication and computation overhead.

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Impact of Government Investment(Development Expenditures)and Chinese Investment on Economic Growth(GDP) of Pakistan

Impact of Government Investment(Development Expenditures)and...

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作者： asad Haseeb Khan 山东大学

学位级别：硕士

鉴于文献中的证据,外国直接投资和政府财政政策以及发展支出对该国的经济发展产生了影响。在这里,巴基斯坦被作为一个案例研究来检验其背后的理念。研究的核心重点是评估政府发展支出和中国外国直接投资对巴基斯坦经济增长的影响。该研... 详细信息

鉴于文献中的证据,外国直接投资和政府财政政策以及发展支出对该国的经济发展产生了影响。在这里,巴基斯坦被作为一个案例研究来检验其背后的理念。研究的核心重点是评估政府发展支出和中国外国直接投资对巴基斯坦经济增长的影响。该研究还观察了中国外国直接投资与政府发展支出对经济增长的关系。本文研究了 1980年至2020年这一时期的影响。上述研究的数据样本取自世界银行数据库和巴基斯坦投资委员会出版物的次要资源。本研究的因变量为GDP增长,自变量为中国对外直接投资、CFDI政府发展支出、GDE,以及两个CFDI*GDE之间的关系,以回归该国的经济增长。在本研究的实证分析中,对收集到的数据进行了多项测试,包括单位根测试、自回归分布滞后(ARDL)、误差修正模型(ECM)、怀特测试、滞后选择标准、Akaike信息标准(AIC)和格兰杰因果关系测试。实证分析采用Eviews和IBM SPSS统计数据。研究发现,中国的投资和GDE在短期内对巴基斯坦的经济增长有积极影响,而在长期内则会产生负面影响。由于政府的一些财政政策有利于中国的投资,并旨在增加投资流入,因此CFDI与政府发展支出之间在短期和长期都存在正相关关系。通过这种方式,GDE刺激了 CFDI,对GDP增长产生了积极影响。然后,该研究进一步分为两个分时期组,以分析CFDI急剧倾斜之前和急剧下降之后,以及2007年之前和之后的分时期之间的关系。尽管CFDI和GDE之间存在负相关关系,但在2007年太阳周期之前,CFDI和GDE促进了经济增长。2007年后,由于GDE为正,而CFDI为负,影响了经济增长,CFDI*GDE呈负相关,因此变量之间的关系发生了急剧下降。这些结果对政策制定者和政府为巴基斯坦经济发展制定有效的经济政策非常有用,对外国投资者了解这一趋势也很有洞察力。

关键词：中国投资政府发展支出经济增长 ARDL 实证研究

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A remotely sensed tracking of forest cover and associatedtemperature change in Margalla hills

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International Journal of Digital Earth 2019年第10期12卷 1133-1150页

作者： Noora Khalid Saleem Ullah Sheikh Saeed Ahmad asad Ali Farrukh Chishtie Department of Space Science Institute of Space TechnologyIslamabadPakistan Department of Environmental Sciences Fatima Jinnah Women UniversityRawalpindiPakistan

Worldwide, forest degradation is a serious environmental issue, and inPakistan, forest wealth is depleting at the highest rate in South Asia. Toensure sustainable development goals of environmental stewardship,social development and economic growth, a sound monitoring andregulatory mechanism is essential for tracking forest cover changes. Thisstudy aims to quantify the decline of forest reserves and associatedtemperature variations in a relatively unexplored biodiversity hotspot ofIslamabad, Margalla Hills National Park (MHNP). Imagery acquired byLandsat TM (Thematic Mapper) for the year 1992, 2000 and 2011 areused to assess the spatial and temporal changes occurred over the lasttwo decades (from 1992 to 2011). A robust hybrid-classification routineis implemented to monitor the changes in forest cover and ANOVAalong with Tukey’s HSD (Honestly Significant Difference) test is used totest the significance of temperature variation associated with a shift inland cover classes. The results showed a significant growth insettlements, agricultural area and barren soil whereas water body, lowervegetation, scrub and pine forest are diminishing. In both decades, thetemperature alteration associated with a change in land cover classesare statistically significant (confirmed by ANOVA and Tukey’s HSD tests)for most of the land use/land cover classes. Based on these findings, thisstudy concludes that forests are dwindling at MHNP and the degradingcondition of the forest is below par and necessitates the promotion ofconservation practices to minimize ecological disturbances.

关键词： Margalla hills Landsat thematic mapper(Landsat TM) forest cover change hybrid classification land cover classes ANOVA Tukey’s HSD

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Design and Development of a 6-DOF Joystick with Force/Torque Sensing

Design and Development of a 6-DOF Joystick with Force/Torque...

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作者： Talha Bin asad 上海交通大学

学位级别：硕士

本研究提出一套完整的操纵杆式感测器设计,该感测器可侦测六个轴的力,并提供力强度。其目的是开发一种适合于未来工业生产的制造技术。为了实现我们的目标,我们首先找到了一个便宜的,市场上可用的2轴力传感器称为跟踪点。经过评估,其输... 详细信息

本研究提出一套完整的操纵杆式感测器设计,该感测器可侦测六个轴的力,并提供力强度。其目的是开发一种适合于未来工业生产的制造技术。为了实现我们的目标,我们首先找到了一个便宜的,市场上可用的2轴力传感器称为跟踪点。经过评估,其输出是良好的可靠和精确到足以用于操纵杆,我们去定制创新的机械硬件设计。机械设计是在SolidWorks软件上进行的,分为多个部分。为了验证设计的可行性,在同一个软件上进行了仿真和有限元分析。在那之后,用三维打印技术来制造它。传感器,即轨迹点,用于沿6轴检测和确定力和扭矩的框架,因此称为6自由度。随后,将零件组装在一起,通过软件检查其可行性,然后实际打印出来。电子元件包括微型控制器,将传感器的原始输出转换为可测量的力强度整数,以及用于遥控操纵杆的无线加密狗;它们安装在操纵杆的下壳体中。开发了一种新的“力映射”方法,利用8个轨迹点传感器框架来确定操纵杆6轴的输出。在最后一步中,进行了一些测试来测试设备。顺便说一句,一个定制的图形用户界面被编程,显示传感器的输出为力方向箭头和力强度数字。实验结果与理论结果一致。在图形用户界面上,我们成功地显示了沿三个轴的力:上、下、左、右、前、后,以及沿三个轴的扭矩:横摆、横摆、纵摇、纵摇、横摇、横摇-。在走向成功的道路上,我们面临着许多问题和挑战。事实上,在测试被称为“柔性铰链”的关键机械部件时,改变设计参数是一个重要的步骤,这将导致更好的输出。随着项目的最新进展,我们将柔性铰链的3D打印材料改为一种比以前更灵活的新材料,设计了一种更好的“力映射”方法来获得准确的输出,并改进了图形用户界面的可视化。因此,最终的结果对于确定外部作用力的方向和强度以及扭矩是有用的。

关键词： FEA GUI 3D打印柔性铰链轨迹点

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A split target detection and tracking algorithm for ballistic missile tracking during the re-entry phase

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Defence Technology（防务技术） 2020年第6期16卷 1142-1150页

作者： Muhammad asad Sumair Khan Ihsanullah Zahid Mehmood Yifang Shi Sufyan Ali Memon Uzair Khan Department of Electrical and Computer Engineering COMSATS University IslamabadAbbottabad CampusPakistan Department of Computer Science COMSATS University IslamabadAbbottabad CampusPakistan Electrical Engineering Department Indus UniversityKarachiPakistan Department of Automation Hangzhou Dianzi UniversityXiasha Higher Education Zone2nd StreetHangzhou310018China

In the re-entry phase of a ballistic missile,decoys can be deployed as a mean to overburden enemy *** results in a single track being split into multiple *** of these track-lets is a critical task as any miss in the tracking procedure can become a cause of a major *** tracking process becomes more complicated in the presence of *** low detection rate is one of the factors that may contribute to increasing the difficulty level in terms of tracking in the cluttered *** work introduces a new algorithm for the split event detection and target tracking under the framework of the joint integrated probabilistic data association(JIPDA)*** proposed algorithm is termed as split event-JIPDA(SE-JIPDA).This work establishes the mathematical foundation for the split target detection and tracking *** performance analysis is made under different simulation conditions to provide a clear insight into the merits of the proposed *** performance parameters in these simulations are the root mean square error(RMSE),confirmed true track rate(CTTR)and confirmed split true track rate(CSTTR).

关键词： Split event probability JIPDA Data association Ballistic missile Estimation

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An enhanced authentication protocol for client server environment

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Frontiers of Computer Science 2020年第6期14卷 193-195页

作者： Muhammad asad SALEEM Shafiq AHMED Khalid MA HMOOD Saru KUMARI Hu XIONG Department of Computer Science COMSATS University IslamabadSahiwal Campus 57000Pakistan Department of Mathematics Ch.Charan Singh UniversityMeerutUtter Paradesh 250002India School of Computer Science and Engineering University of Electronic Science and Technology of ChinaChengdu 610000China

1 Introduction and our contributions Remote user access has become very easy because of different functions provided by rapid development in internet *** providing access to system the responsibility of the system does not limit *** system must implement some sort of security framework otherwise an adversary may disturb or use the resources of the system without seeking permission.

关键词： client server Remote

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A study of nonlinear biochemical reaction model

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International Journal of Biomathematics 2016年第5期9卷 121-129页

作者： Muhammad asad Iqbal Syed Tauseef Mohyud-Din Bandar Bin-Mohsin Department of Mathematics HITEC University Taxila Pakistan Department of Mathematics College of Science King Saud University Riyadh Saudi Arabia

The present study deals with the introduction of an alteration in Legendre wavelets method by availing of the Picard iteration method for system of differential equations and named it Legendre wavelet-Picard method （LWPM）. Convergence of the proposed method is also discussed. In order to check the competence of the proposed method, basic enzyme kinetics is considered. Systems of nonlinear ordinary differential equations are formed from the considered enzyme-substrate reaction. The results obtained by the proposed LWPM are compared with the numerical results obtained from Runge-Kutta method of order four （RK-4）. Numerical results and those obtained by LWPM are in excellent conformance, which would be explained by the help of table and figures. The proposed method is easy and simple to implement as compared to the other existing analytical methods used for solving systems of differential equations arising in biology, physics and engineering.

关键词： Legendre wavelets method Picard iteration method nonlinear biochemical reaction model Runge- Kutta method of order four.

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