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Green Energy & Environment 2024年第10期9卷 1627-1640页

作者： Junaid Saleem Moghal Zubair Khalid Baig usman Bin shahid Rafael Luque Gordon McKay Division of Sustainable Development College of Science and EngineeringHamad Bin Khalifa UniversityQatar FoundationQatar Center for Advanced Materials Qatar UniversityQatar Department of Chemical and Biological Engineering The Hong Kong University of Science and TechnologyKowloonHong KongChina Universidad ECOTEC Km 13.5 SamborondonSamborondonEC092302Ecuador

Plastic waste is an underutilized resource that has the potential to be transformed into value-added ***,its chemical diversity leads to cost-intensive sorting techniques,limiting recycling and upcycling ***,we report an open-loop recycling method to produce graded feedstock from mixed polyolefins waste,which makes up 60%of total plastic *** method uses heat flow scanning to quantify the composition of plastic waste and resolves its compatibility through controlled *** resulting feedstock is then used to synthesize blended pellets,porous sorbents,and superhydrophobic coatings via thermally induced phase separation and *** hybrid approach broadens the opportunities for reusing plastic waste,which is a step towards creating a more circular economy and better waste management practices.

关键词： Plastic waste Valorization Superhydrophobic coatings Blended pellets Porous materials Sorbents

Multi Criteria Decision Making for Evaluation and Ranking of Cancer Information

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Computers, Materials & Continua 2023年第2期74卷 4469-4481页

作者： shahid Mahmood Muhammad Amin Mubashir Baig Mirza Salem Abu-Ghumsan Muhammad Akram Zahid Mahmood Janjua Arslan shahid usman shahid College of Dentistry Prince Sattam Bin Abdul Aziz UniversityAlkharj11942Saudi Arabia Department of Avionics Engineering Institute of Space TechnologyIslamabadPakistan University of Engineering&Technology Lahore56000Pakistan Systems International Lahore56000Pakistan Arif Memorial Hospital Lahore56000Pakistan University of Central Punjab Lahore56000Pakistan

Cancer is a disease that is rapidly expanding in prevalence all over the *** cells canmetastasize,or spread,across the body and impact several different cell ***,the incidence rates of several subtypes of cancer have been on the rise in *** countermeasures for the cancer disease can be taken by determining the specific expansion rate of each *** rank the various forms of cancer’s rate of progression,we used some of the available *** studies are available in the literature which show the growth rate of cancer by different *** accuracy of the scheme in determining the highest growth rate may vary due to the variation in the dependent *** the context of this research,the Fuzzy triangular technique for order preference by similarity to ideal solution(TOPSIS),is utilized to rank the various categorizations of cancer with the help of four groups of medical professionals acting in the capacity of *** number of decision-makers may variate according to the required accuracy of *** findings of the three-dimensional Fuzzy TOPSIS analysis categorize each variety of cancer according to the rate at which it spreads over *** results along with visual representation are presented to examine the efficiency of our proposed work.

关键词： Cancer fuzzy set TOPSIS triangular fuzzy number

Platinum on nitrogen doped graphene and tungsten carbide supports for ammonia electro-oxidation reaction

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Frontiers of Chemical Science and Engineering 2022年第6期16卷 930-938页

作者： Kumar Siddharth Yian Wang Jing Wang Fei Xiao Gabriel Sikukuu Nambafu usman Bin shahid Fei Yang Ernest Pahuyo Delmo Minhua Shao Department of Chemical and Biological Engineering The Hong Kong University of Science and TechnologyHong KongChina Department of Materials Science and Engineering South University of Science and Technology of ChinaShenzhen 518055China Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) The Hong Kong University of Science and TechnologyHong KongChina Chinese National Engineering Research Center for Control&Treatment of Heavy Metal Pollution The Hong Kong University of Science and TechnologyHong KongChina

Ammonia electrooxidation reaction involving multistep electron-proton transfer is a significant reaction for fuel cells,hydrogen production and understanding nitrogen *** has been established as the best electrocatalyst for ammonia oxidation in aqueous alkaline *** this study,Pt/nitrogen-doped graphene(NDG)and Pt/tungsten monocarbide(WC)/NDG are synthesized by a wet chemistry method and their ammonia oxidation activities are compared to commercial Pt/***/NDG exhibits a specific activity of 0.472 mA·cm^(-2),which is 44%higher than commercial Pt/C,thus establishing NDG as a more effective support than carbon ***,it is demonstrated that WC as a support also impacts the activity with further 30%increase in comparison to *** modification with Ir resulted in the best electro-catalytic activity with Pt-IrAVC/NDG having almost thrice the current density of commercial Pt/*** work adds insights regarding the role of NDG and WC as efficient supports along with significant impact of Ir surface modification.

关键词： Ammonia electro-oxidation reaction electrocatalyst supports platinum nitrogen doped graphene tungsten carbide

不同封堵场景下火源位置对隧道火灾行为影响的数值模拟研究

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不同封堵场景下火源位置对隧道火灾行为影响的数值模拟研究

作者： MUHAMMAD usman shahid 中国科学技术大学

学位级别：硕士

地下隧道发生火灾时,火灾烟气的吸入会对人员的生命安全构成直接威胁,对火行为的了解是做出有效决策的关键。以往对隧道火灾动力学的研究多设定隧道两端均处于开口状态的通风条件。在列车车厢火灾、在建隧道火灾、隧道走廊火灾等特殊隧... 详细信息

地下隧道发生火灾时,火灾烟气的吸入会对人员的生命安全构成直接威胁,对火行为的了解是做出有效决策的关键。以往对隧道火灾动力学的研究多设定隧道两端均处于开口状态的通风条件。在列车车厢火灾、在建隧道火灾、隧道走廊火灾等特殊隧道火灾场景下,隧道两端可能会完全或不完全地被阻塞或封闭,这将严重干扰隧道内部通风和火灾烟气蔓延的情况。目前,针对隧道狭长空间两端端部封堵状态下火灾行为的研究非常有限。基于计算机的模拟仿真工作在评估隧道火灾的后果方面是非常有用、灵活和低成本的。本研究利用火灾动力学模拟软件(FDS)来评估全尺寸隧道内的火灾特性,开展了一系列数值模拟工作,以研究在不同火灾位置、封堵时间及封堵入口比的综合作用下的火灾行为,探测并计算得到了一系列特征参数,如火源上方温度,纵向烟气温度分布,纵向氧气分布,火源附近的热通量,入口处的CO浓度以及入口处的烟气温度等。研究结果表明,火源上方的温度随着火源远离隧道中心及入口处封堵的实施而降低,而峰值增加,最大值出现在不对等封堵的情况下(75%,100%),并且封堵时间越早,温度达到峰值的时间越短然后下降。当火源放置在隧道中央并且火源两侧对称封堵时,纵向烟气温度的分布也是对称的,峰值温度随着封堵率增加而增加,随着封堵时间延长而降低,封堵场景和无封堵场景之间的差异很大,并且呈指数衰减。此外,当火源远离隧道中央时,由于火焰向附近的入口倾斜,火源两侧的温度分布不再对称,左侧的温度值更高。火源附近的热通量总是随着火源远离隧道中心而减小,热通量减小但是其随着封堵时间的增加而增大。当火源非常靠近入口时,上述现象由于较高的入口温度而出现不同。在这种情况下,通过增加封堵率可增加热通量,在不对等封堵的情况下(75%,100%)记录到最大热通量。左侧入口处的CO浓度始终随着火源远离隧道中央和封堵率的增加而增加,但是没有发现封堵时间对其的显著影响。而且,在实施封堵之前,火源位置的变化对隧道内部的氧气浓度没有影响。由于隧道内的烟尘积累,提高封堵比会降低氧气含量,而更早的封堵时间将是更少的氧气,因为更早的封堵会限制隧道内的新鲜空气流动。封堵时间不会影响入口处的烟气温升,但是通过改变无封堵时的火源位置,入口处的温升会从200℃增加到300℃。通过实施(75%,100%)的封堵,入口处的温度可升至800℃以上。因此,消防人员在火灾发生时应考虑这种不对称的封堵因素。

关键词：隧道火灾火灾动力模拟器封堵入口封堵时间纵向温度衰减热通量 CO浓度

Consequences of Rényi entropy on the thermal geometries and Hawking evaporation of topological dyonic dilaton black hole

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Communications in Theoretical Physics 2024年第2期76卷 102-110页

作者： Muhammad Yasir Xia Tiecheng Muhammad usman shahid Chaudhary Department of Mathematics Shanghai University and Newtouch Center for Mathematics of Shanghai UniversityShanghai200444China Department of Natural Sciences and Humanities University of Engineering and Technology LahoreNew CampusPakistan

The thermodynamics of black holes(BHs)has had a profound impact on theoretical physics,providing insight into the nature of gravity,the quantum structure of spacetime and the fundamental laws governing the *** this study,we investigate thermal geometries and Hawking evaporation of the recently proposed topological dyonic dilaton BH in anti-de Sitter(Ad S)*** consider Rényi entropy and obtain the relations for pressure,heat capacity and Gibbs free energy and observe that the Rényi parameter and dilaton field play a vital role in the phase transition and stability of the ***,we use Weinhold,Ruppeiner and Hendi Panahiyah Eslam Momennia models to evaluate the scalar curvature of the BH and find out that the divergence points of the scalar curvature coincides with the zero of specific ***,using Stefan–Boltzmann law,we determine that the BH without a dilaton field evaporates far more quickly compared to the dilaton BH in Ad S space.

关键词： topological dyonic dilaton black hole phase transition thermal geometry Hawking evaporation

Floating Solid Particles Interacting with Tilted Square Obstacles in Fluid Affecting Drag Forces

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Advances in Applied Mathematics and Mechanics 2023年第2期15卷 359-375页

作者： K.usman S.Jabeen M.shahid Department of Mathematics Air UniversityPAF ComplexIslamabad 44000Pakistan

We have analyzed the kinetics of solid circular particles interacting with fluid,outer boundary and internal square shaped obstacles tilted at a 45°*** effects on the motion of particle due to collision with obstacles and wall are *** Eulerian approach is used to study the behavior of particle in the fixed computational *** interactions between fluid,particles and obstacles have been carried out in the whole domain by using fictitious boundary method(FBM).In this work,the particulate flow simulations are computed by using finite element solver *** results are presented by assigning different alignments to the obstacles and varying their positions in the ***-wall,particle-particle and particleobstacle collisions are treated by applying a modified collision model proposed by Glowinski et *** rapid change in drag forces acting on obstacles due to nearby passing particles and its effect on the fluid motion has been investigated.

关键词： Particulate flow direct numerical simulation fictitious boundary method finite element method multigrid sedimentation

A Secure Method for Data Storage and Transmission in Sustainable Cloud Computing

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Computers, Materials & Continua 2023年第5期75卷 2741-2757页

作者： Muhammad usman Sana Zhanli Li Tayybah Kiren Hannan Bin Liaqat shahid Naseem Atif Saeed College of Computer Science and Technology Xi’an University of Science and TechnologyXi’anShaanxi710054China Department of Computer Science(RCET Campus) University of Engineering and TechnologyLahore39161Pakistan Department of Information Sciences Division of Science&TechnologyUniversity of EducationLahore54700Pakistan Department of Computer Science COMSATS UniversityIslamabadLahore54700Pakistan

Cloud computing is a technology that provides secure storage space for the customer’s massive data and gives them the facility to retrieve and transmit their data efficiently through a secure network in which encryption and decryption algorithms are being *** cloud computation,data processing,storage,and transmission can be done through laptops andmobile *** Storing in cloud facilities is expanding each day and data is the most significant asset of *** important concern with the transmission of information to the cloud is security because there is no perceivability of the client’s *** have to be dependent on cloud service providers for assurance of the platform’s *** security and privacy issues reduce the progression of cloud computing and add ***;most of the data that is stored on cloud servers is in the form of images and photographs,which is a very confidential form of data that requires secured *** this research work,a public key cryptosystem is being implemented to store,retrieve and transmit information in cloud computation through a modified Rivest-Shamir-Adleman(RSA)algorithm for the encryption and decryption of *** implementation of a modified RSA algorithm results guaranteed the security of data in the cloud *** enhance the user data security level,a neural network is used for user authentication and ***;the proposed technique develops the performance of detection as a loss function of the bounding *** Faster Region-Based Convolutional Neural Network(Faster R-CNN)gets trained on images to identify authorized users with an accuracy of 99.9%on training.

关键词： Cloud computing data security RSA algorithm Faster R-CNN

Robust iris biometric system for visible wavelength data

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Chinese Optics Letters 2013年第8期11卷 57-63页

作者： Farmanullah Jan Imran usman shahid A. Khan Department of Physics COMSATS Institute of Information Technology Department of Electrical Engineering COMSATS Institute of Information Technology Center for Advanced Studies in Telecommunications COMSATS Institute of Information Technology

Commercial iris biometric systems exhibit good formance for visible wavelength （VW） data. To performance for near-infrared （NIR） images but poor per- address this problem, we propose an iris biometric system for VW data. The system includes localizing iris boundaries that use bimodal thresholding, Euclidean distance transform （EDT）, and a circular pixel counting scheme （CPCS）. Eyelids are localized using a parabolic pixel counting scheme （PPCS）, and eyelashes, light reflections, and skin parts are adaptively detected using image intensity. Features are extracted using the log Gabor filter, and finally, matching is performed using Hamming distance （HD）. The experimental results on UBIRIS and CASIA show that the proposed technique outperforms contemporary approaches.

关键词： Otsu FRR NIR SIFT ROI Figure

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

A Two Stream Fusion Assisted Deep Learning Framework for Stomach Diseases Classification

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Computers, Materials & Continua 2022年第11期73卷 4423-4439页

作者： Muhammad shahid Amin Jamal Hussain Shah Mussarat Yasmin Ghulam Jillani Ansari Muhamamd Attique Khan usman Tariq Ye Jin Kim Byoungchol Chang Department of Computer Science COMSATS University IslamabadWah CampusPakistan Department of Information Sciences University of Education Lahore(Multan Campus)Pakistan Department of Computer Science HITEC University TaxilaPakistan College of Computer Engineering and Sciences Prince Sattam bin Abdulaziz UniversityAl-KharjSaudi Arabia Department of Computer Science Hanyang UniversitySeoul04763Korea Center for Computational Social Science Hanyang UniversitySeoul04763Korea

Due to rapid development in Artificial Intelligence(AI)and Deep Learning(DL),it is difficult to maintain the security and robustness of these techniques and algorithms due to emergence of novel term adversary *** technique is sensitive to these ***,fake samples cause AI and DL model to produce diverse *** attacks that successfully implemented in real world scenarios highlight their applicability even *** this regard,minor modifications of input images cause“Adversarial Attacks”that altered the performance of competing attacks ***,such attacks and defensive strategies are gaining lot of attention by the machine learning and security *** use different kinds of technologies to examine the patient abnormalities including Wireless Capsule Endoscopy(WCE).However,using WCE it is very difficult for doctors to detect an abnormality within images since it takes enough time while inspection and deciding *** a result,it took weeks to generate patients test report,which is tiring and strenuous for ***,researchers come out with the solution to adopt computerized technologies,which are more suitable for the classification and detection of such *** far as the classification is concern,the adversarial attacks generate problems in classified *** days,to handle this issue machine learning is mainstream defensive approach against adversarial ***,this research exposes the attacks by altering the datasets with noise including salt and pepper and Fast Gradient Sign Method(FGSM)and then reflects that how machine learning algorithms work fine to handle these noises in order to avoid *** obtained on the WCE images which are vulnerable to adversarial attack are 96.30%accurate and prove that the proposed defensive model is robust when compared to competitive existing methods.

关键词： WCE images adversarial attacks FGSM noise salt and pepper noise feature fusion deep learning