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在镁AZ91合金上化学共沉积GO与硅烷纳米复合涂层

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在镁AZ91合金上化学共沉积GO与硅烷纳米复合涂层

作者： muhammad uzair malik 北京化工大学

学位级别：硕士

镁合金是现有最轻的结构材料。镁合金的独特性能包括低密度、高导热率、高强度/重量比、出色的机加工性和良好的可回收性。由于这些优异的性能,镁合金具有减重和减少燃料消耗的能力,适合在航空航天零件、汽车、电子、海水电池和整形外... 详细信息

镁合金是现有最轻的结构材料。镁合金的独特性能包括低密度、高导热率、高强度/重量比、出色的机加工性和良好的可回收性。由于这些优异的性能,镁合金具有减重和减少燃料消耗的能力,适合在航空航天零件、汽车、电子、海水电池和整形外科等领域中应用。由于具有出色的抗蠕变性能和机械强度,镁合金已经在许多结构应用中使用。不幸的是,镁及其合金的主要局限性是其在腐蚀环境中的降解速率较快和热力学不稳定性较差。因此,研究人员一直致力于研究镁及其合金的降解机理。本论文研究的主要目的是使用基于硅烷的纳米复合涂层来增强AZ91镁合金的防腐蚀性能。该硅烷基纳米复合涂料无毒、环境友好,主要用于改善AZ91镁合金的屏蔽性能。该项工作分可为两个部分,一是增强硅烷涂层在AZ91镁合金上的耐腐蚀性,二是提高膜层的机械性能。在第一部分,使用无电共沉积技术在AZ91镁合金试样上开发了(3-环氧丙氧基丙基)三甲氧基硅烷/氧化石墨烯(GPTMS/GO)涂层,其中利用硅烷醇基团对GO薄板进行接枝改性。将AZ91镁合金浸入GPTMS/GO溶液中12 h,然后在120℃温度条件下固化,从而形成涂层。电化学测试结果表明,该涂层增强了 AZ91镁合金在3.5%NaCl溶液中的耐腐蚀性。由于在Mg AZ91的表面上形成了 GO接枝的GPTMS钝化膜层,使腐蚀电流密度值降低0.0102μA cm-2。由于共价金属硅氧烷键(MgOSi)和GO在AZ91基板上形成的层状结构,膜层的疏水性增强(108°),附着力(5A)和硬度(52 HV)均得到提高。在第二部分,使用无电沉积技术成功地在AZ91镁合金试样上制备得到GPTMS/GO/FAS涂层。通过将镁合金试样在GPTMS/GO和水解的FAS溶液浸泡24小时,然后在120℃的烤箱中固化,形成GPTMS/GO/FAS涂层。采用FTIR,XPS,SEM和EDS等不同的表征技术对镁AZ91合金表面形成的GPTMS/GO/FAS涂层进行表征。GPTMS/GO/FAS涂层的厚度随着浸入时间的增加而显著增加,GPTMS/GO/FAS涂层显示出优异的粘合性能和良好的疏水性。此外,涂层也显示出良好的机械性能。电化学测试证实了涂层耐腐蚀性能的提高。GPTMS/GO/FAS0.50mL涂层在3.5%NaCl溶液中显示出最低的腐蚀电流密度(5.03×10-μA cm-2)和最高的电阻(Rct=1272 kΩ cm2)。此外,还研究了浸泡时间对涂层完整性的影响,该试样浸入3.5%NaCl溶液中7天后仍显示出良好的效果。因此,GPTMS/GO/FAS0.50mL涂层对AZ91镁合金具有良好的防腐性能。

关键词： (3-环氧丙氧基丙基) 三甲氧基硅烷七氟-1,1,2,2-十四烷基三甲氧基硅烷氧化石墨烯 AZ91镁合金腐蚀防护

Decoding molecular mechanisms:brain aging and Alzheimer's disease

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Neural Regeneration Research 2025年第8期20卷 2279-2299页

作者： Mahnoor Hayat Rafay Ali Syed Hammad Qaiser Mohammad uzair Khalid Al-Regaiey Roaa Khallaf Lubna Abdullah Mohammed Albassam Imdad Kaleem Xueyi Wang Ran Wang Mehwish SBhatti Shahid Bashir Atta-ur-Rahman School of Applied Biosciences(ASAB) National University of Sciences and Technology(NUST)IslamabadPakistan Department of Biotechnology Quaid-i-Azam UniversityIslamabadPakistan Department of Biological Sciences Faculty of Basic&Applied SciencesInternational Islamic University Islamabad(IIUI)IslamabadPakistan Department of Bioengineering King Fahd University of Petroleum and MineralsDhahranSaudi Arabia Department of Physiology College of MedicineKing Saud UniversityRiyadhSaudi Arabia Department of Neurology Neuroscience CenterKing Fahad Specialist HospitalDammamSaudi Arabia Department of Mental Health Neuroscience CenterKing Fahad Specialist HospitalDammamSaudi Arabia Department of Biosciences Commission on Science and Technology for Sustainable Development in the South(COMSATS University)IslamabadPakistan Department of Psychiatry The First Hospital of Hebei Medical UniversityShijiazhuangHebei ProvinceChina Mental Health Institute of Hebei Medical University ShijiazhuangHebei ProvinceChina Department of Neurobiology and Behavior University of CaliforniaIrvineCAUSA Neuroscience Center King Fahad Specialist Hospital DammamDammamSaudi Arabia

The complex morphological,anatomical,physiological,and chemical mechanisms within the aging brain have been the hot topic of research for *** aging process alters the brain structure that affects functions and cognitions,but the worsening of such processes contributes to the pathogenesis of neurodegenerative disorders,such as Alzheimer's *** these observable,mild morphological shifts,significant functional modifications in neurotransmission and neuronal activity critically influence the aging *** these changes is important for maintaining cognitive health,especially given the increasing prevalence of age-related conditions that affect *** review aims to explore the age-induced changes in brain plasticity and molecular processes,differentiating normal aging from the pathogenesis of Alzheimer's disease,thereby providing insights into predicting the risk of dementia,particularly Alzheimer's disease.

关键词： Alzheimer’s disease brain aging cognitive health dementia molecular mechanisms neuronal activity neuroplasticity neurotransmission

Dynamic flexural strength of Aluminosilicate glass with a perspective of impulsive and quasi-impulsive responses: An experimental-numerical coupled evaluation

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Chinese Journal of Aeronautics 2024年第12期37卷 388-403页

作者： muhammad Aamir RAZA Tao SUO uzair Ahmed DAR muhammad ATIF muhammad Zakir SHEIKH School of Aeronautics and Institute of Extreme Mechanics Northwestern Polytechnical UniversityXi’an 710072China Joint International Research Center of Impact Dynamics and Its Engineering Application Northwestern Polytechnical UniversityXi’an 710072China Shaanxi Key Laboratory of Impact Dynamics and Engineering Application Northwestern Polytechnical UniversityXi’an 710072China National Key Laboratory of Strength and Structural Integrity Northwestern Polytechnical UniversityXi’an 710072China

The flexural strength of glass is a critical design parameter for applications encountering impact ***,the micro defects,specimen geometry,loading rate,and load transformation from a quasi-dynamic to quasi-impulsive state may influence the measurement *** to the stochastic and amorphous nature of the material,an accurate determination of the flexural strength remains a *** this two-fold study,a coupled experimental-numerical strategy was devised to evaluate the dynamic flexural *** the first phase,three-point bending experiments were conducted on a novel“Electromagnetic Split Hopkinson Pressure Bar(ESHPB)”.The incident stress signal and fracture time were recorded from experimental data,while the flexural strength was indirectly computed from a numerical algorithm.A quantitative comparison of the flexural strength with those in existing literature established the accuracy of the proposed *** of the study indicate that the specimen response became independent of the support conditions under impulsive *** being said,the specimen behaved like it had an infinite span length,and the measured flexural strength remained the same whether the specimen was supported or ***,the specimen also maintained contact at the interfaces of the incident bar and fixture supports for the entire loading *** the second part of this study,the computed flexural strength was used to calibrate the existing JH-2 *** prediction of the damage propagation corroborated with that obtained from reprography images,though *** work presents a precise and robust methodology to determine the dynamic flexural strength of brittle ceramics like Aluminosilicate glass over traditional experimental procedures to facilitate its adoption.

关键词： Dynamic flexural strength Damage mechanism Flexural fracture Numerical simulation Aluminosilicate glass

A Progressive Approach to Generic Object Detection: A Two-Stage Framework for Image Recognition

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Computers, Materials & Continua 2023年第6期75卷 6351-6373页

作者： muhammad Aamir Ziaur Rahman Waheed Ahmed Abro uzair Aslam Bhatti Zaheer Ahmed Dayo muhammad Ishfaq College of Computer Science Huanggang Normal UniversityHuanggangHubei438000China FAST School of Computing National University of Computer&Emerging Science(NUCES)Karachi CampusKarachi75030Pakistan School of Information and Communication Engineering Hainan UniversityHaikou68000China

Object detection in images has been identified as a critical area of research in computer vision image *** has developed several novel methods for determining an object’s location and category from an ***,there is still room for improvement in terms of detection *** study aims to develop a technique for detecting objects in *** enhance overall detection performance,we considered object detection a two-fold problem,including localization and *** proposed method generates class-independent,high-quality,and precise proposals using an agglomerative clustering *** then combine these proposals with the relevant input image to train our network on convolutional ***,a network refinement module decreases the quantity of generated proposals to produce fewer high-quality candidate ***,revised candidate proposals are sent into the network’s detection process to determine the object *** algorithm’s performance is evaluated using publicly available the PASCAL Visual Object Classes Challenge 2007(VOC2007),VOC2012,and Microsoft Common Objects in Context(MS-COCO)*** only 100 proposals per image at intersection over union((IoU)=0.5 and 0.7),the proposed method attains Detection Recall(DR)rates of(93.17%and 79.35%)and(69.4%and 58.35%),and Mean Average Best Overlap(MABO)values of(79.25%and 62.65%),for the VOC2007 and MS-COCO datasets,***,it achieves a Mean Average Precision(mAP)of(84.7%and 81.5%)on both VOC *** experiment findings reveal that our method exceeds previous approaches in terms of overall detection performance,proving its effectiveness.

关键词： Deep neural network deep learning features agglomerative clustering localizations refinement region of interest(ROI) object detection

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

A Low-Cost,Real-Time Rooftop IoT-Based Photovoltaic(PV)System for Energy Management and Home Automation

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Energy Engineering 2022年第1期119卷 83-101页

作者： muhammad uzair Salah Al-Kafrawi Karam Al-Janadi Ibrahim Al-Bulushi Electrical Engineering Department Islamic University of MedinaMedina42315Saudi Arabia

This work discusses the importance of monitoring and energy management of green energy resources in order to minimize the negative impacts of electricity generation by regular power *** paper introduces a highly efficient,low-cost rooftop photovoltaics(PV)solar panel system which can provide monitoring,controlling and *** proposed system is based on Internet of Things(IoT)and can be used to control different utilities in any premises automatically or set by the user-defined priority list,as compared to the existing IoT-based PV systems which can only perform monitoring and maintenance of the PV panels or only certain parameters,i.e.,temperature,dust,*** is a new step in improving the efficiency of IoT-based PV system where the facility loads are automated by the IoT *** proposed system can also provide a constant feedback about different parameters,i.e.,voltage,dust,sun irradiance and humidity,etc.,via low-cost open-source platforms for telemonitoring and controlling *** simulation results showthat the proposed system provides a high efficiency to energize the utilities and utilize the available energy as compared to the manual control.

关键词： Photovoltaic internet of things automation monitoring performance analysis

Transcranial magnetic stimulation in animal models of neurodegeneration

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Neural Regeneration Research 2022年第2期17卷 251-265页

作者： Mohammad uzair Turki Abualait muhammad Arshad Woo-Kyoung Yoo Ali Mir Reem Fahd Bunyan Shahid Bashir Department of Biological Sciences Faculty of Basic&Applied SciencesInternational Islamic University IslamabadPakistan College of Applied Medical Sciences Imam Abdulrahman Bin Faisal UniversityDammamSaudi Arabia Department of Physical Medicine and Rehabilitation Hallym University College of MedicineAnyangSouth Korea Hallym Institute for Translational Genomics&Bioinformatics Hallym University College of MedicineAnyangSouth Korea Neuroscience Center King Fahad Specialist Hospital DammamDammamSaudi Arabia

Brain stimulation techniques offer powerful means of modulating the physiology of specific neural structures. In recent years, non-invasive brain stimulation techniques, such as transcranial magnetic stimulation(TMS) and transcranial direct current stimulation, have emerged as therapeutic tools for neurology and neuroscience. However, the possible repercussions of these techniques remain unclear, and there are few reports on the incisive recovery mechanisms through brain stimulation. Although several studies have recommended the use of non-invasive brain stimulation in clinical neuroscience, with a special emphasis on TMS, the suggested mechanisms of action have not been confirmed directly at the neural level. Insights into the neural mechanisms of non-invasive brain stimulation would unveil the strategies necessary to enhance the safety and efficacy of this progressive approach. Therefore, animal studies investigating the mechanisms of TMSinduced recovery at the neural level are crucial for the elaboration of non-invasive brain stimulation. Translational research done using animal models has several advantages and is able to investigate knowledge gaps by directly targeting neuronal levels. In this review, we have discussed the role of TMS in different animal models, the impact of animal studies on various disease states, and the findings regarding brain function of animal models after TMS in pharmacology research.

关键词： Alzheimer's disease depression glial cells neurorehabilitation Parkinson's disease repetitive transcranial magnetic stimulation transcranial direct current stimulation transcranial magnetic stimulation

Natural gait analysis for a biped robot: jogging ***

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Science China(Information Sciences) 2019年第12期62卷 272-276页

作者： uzair KHAN Zhiyong CHEN School of Electrical Engineering and Computing University of NewcastleCallaghan

Dear editor,Humans have long been looking in animal locomotion for inspiration to solve their complex design problems. Numerous control strategies mimic simple biological processes. Feedback control is one such exampl... 详细信息

关键词： spring jogging vs.walking Natural gait analysis for a biped robot

3D Kronecker Convolutional Feature Pyramid for Brain Tumor Semantic Segmentation in MR Imaging

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Computers, Materials & Continua 2023年第9期76卷 2861-2877页

作者： Kainat Nazir Tahir Mustafa Madni uzair Iqbal Janjua Umer Javed muhammad Attique Khan Usman Tariq Jae-Hyuk Cha Medical Imaging and Diagnostics Lab NCAIDepartment of Computer ScienceCOMSATS University IslamabadIslamabad44000Pakistan Department of Electrical and Computer Engineering COMSATS University IslamabadWah CampusWahPakistan Department of Computer Science HITEC UniversityTaxilaPakistan Department of Management Information Systems College of Business AdministrationPrince Sattam Bin Abdulaziz UniversityAl-Kharj16273Saudi Arabia Department of Computer Science Hanyang UniversitySeoul04763Korea

Brain tumor significantly impacts the quality of life and changes everything for a patient and their loved *** a brain tumor usually begins with magnetic resonance imaging(MRI).The manual brain tumor diagnosis from the MRO images always requires an expert ***,this process is time-consuming and ***,a computerized technique is required for brain tumor detection in MRI *** the MRI,a novel mechanism of the three-dimensional(3D)Kronecker convolution feature pyramid(KCFP)is used to segment brain tumors,resolving the pixel loss and weak processing of multi-scale lesions.A single dilation rate was replaced with the 3D Kronecker convolution,while local feature learning was performed using the 3D Feature Selection(3DFSC).A 3D KCFP was added at the end of 3DFSC to resolve weak processing of multi-scale lesions,yielding efficient segmentation of brain tumors of different sizes.A 3D connected component analysis with a global threshold was used as a post-processing *** standard Multimodal Brain Tumor Segmentation 2020 dataset was used for model *** 3D KCFP model performed exceptionally well compared to other benchmark schemes with a dice similarity coefficient of 0.90,0.80,and 0.84 for the whole tumor,enhancing tumor,and tumor core,***,the proposed model was efficient in brain tumor segmentation,which may facilitate medical practitioners for an appropriate diagnosis for future treatment planning.

关键词： Brain tumor segmentation connect component analysis deep learning kronecker convolution magnetic resonance imaging