检索结果-南通市图书馆

High performance room temperature gas sensor based on novel morphology of zinc oxide nanostructures

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2019年第1期29卷 143-156页

作者： Naila ZUBAIR Khalida akhtar National Center of Excellence in Physical Chemistry University of Peshawar

Zinc oxide uniform nanostructures with novel morphologies were synthesized through simple and fast ammonia based controlled precipitation method in aqueous media and in the absence of any additive. Selected batches of the synthesized solids were characterized by SEM, XRD, FTIR and TG/DTA. FTIR analysis revealed that the morphology of nanostructures had little effect on their IR spectral profile of the synthesized material. The as-prepared, calcined and commercial ZnO nanostructures (ZnO-AP, ZnO-Cal and ZnO-Com) were then employed as gas sensors for the detection of ammonia, acetone and ethanol. ZnO-AP and ZnO-Cal based sensors showed superior and reproducible performance towards 1×10^-6 ammonia with gas response of 63.79% and 66.87% and response/recovery time of 13 and 3 s, respectively, at room temperature (29℃). This was attributed to the unique morphology and remarkable uniformity in shape and size of the synthesized nanostructures. In contrast, the ZnO-Com based sensor did not respond to ammonia concentration less than 200×10^-6. In addition, ZnO-Cal showed high selectivity to ammonia as compared to acetone and ethanol at room temperature. Moreover, the lowest detection limit was 1×10^-6, which demonstrates excellent ammonia sensing characteristics of the synthesized ZnO.

关键词： zinc oxide nanostructures gas sensor sensitivity response/recovery time

Data Fusion of Velodyne LiDAR and Monocular Camera with Its Applications

在线全文

学校读者我要写书评

暂无评论

Data Fusion of Velodyne LiDAR and Monocular Camera with Its ...

作者： Mohd Rayyan akhtar 华南理工大学

学位级别：硕士

Data fusion of multi-modal sensors is required to build a robust system because the individualsensor has its own limitations to extract the information and process *** fusion integrates the merits of the multi-modal sensors to build a robust *** thesis is related to the data fusion of three dimensional（3D）Light Detection and Ranging（LiDAR）VLP-16 from Velodyne and a monocular camera for 3D reconstruction,two dimensional（2D）depth map,object detection and depth estimation.3D reconstruction is mainly categorized into two types indoor mapping and outdoor *** thesis is related to the indoor mapping in which the research is done in an indoor *** can detect the distance of the object very accurately but it cannot provide the information about the color and texture of the object.2D Image is limited to only plane information such as shape,texture and color information;hence it loses the details of the third dimension due to perspective *** thesis can be summarized in three ***,the development of a 3D-3D correspondence rigid-body extrinsic calibration methodology for the 3D LiDAR sensor and monocular *** is necessary to represent the sensor data in common coordinate ***-made calibration pattern is used for the LiDAR-camera extrinsic calibration to generate a transformation ***,the range sensor and image data fusion is performed by using transformation matrix to build a 2D depth map and 3D reconstruction of the scene objects.2D depth map is interpolated to fill the empty locations due to sparse data of range sensor by using the proposed method of ***,the application of sensor data fusion for the object detection and depth *** object detection is performed on the images by using convolutional neural network along with You Only Look Once（YOLO）*** data fused with image data is used to measure the object distance from the *** cloud segmentat

关键词： Velodyne激光雷达单目相机数据融合

Evaluating effect of chloride attack and concrete cover on the probability of corrosion

同方学位论文库评论

在线全文

同方学位论文库

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2013年第4期7卷 379-390页

作者： Sanjeev Kumar VERMA Sudhir Singh BHADAURIA Saleem akhtar Civil Engineering Department University Institute of TechnologyRajiv Gandhi Technological UniversityBHOPAL Madhya Pradesh 462036India S.G.S.Institute of Technology and Science INDORE Madhya Pradesh 452003India

Corrosion of reinforced concrete(RC)structures is one of the significant causes of deterioration of reinforced concrete(RC)*** is a major process governing the initiation and advancement of the injurious corrosion of steel ***,several researches on the chlorination of concrete structures have been ongoing around the *** article reviews several recently performed chlorination studies,and from results of a field survey evaluates the effect of chloride content on the probability of corrosion and the influence of concrete compressive strength on the chloride content and penetration,also evaluates the effect of concrete cover over the chloride content of the RC structures at rebar depth and on the probability of corrosion.

关键词： concrete chloride reinforcement corrosion deterioration cover

Influence of ellagic acid on prostate cancer cell proliferation:A caspase-dependent pathway

在线全文

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Medicine 2011年第7期4卷 550-555页

作者： Arshi Malik Sarah Afaq Mohammad Shahid Kafil akhtar Abdullah Assiri Department of Clinical Biochemistry College of MedicineKing Khalid UniversityAbhaKingdom of Saudi Arabia Department of Microbiology Jawaharlal Nehru Medical CollegeAligarh Muslim UniversityAligarhIndia Department of Pathology Jawaharlal Nehru Medical CollegeAligarh Muslim UniversityAligarhIndia Interventional Cardiologist College of MedicineKing Khalid UniversityAbhaKingdom of Saudi Arabia

Objective:To evaluate the effect of allagic acid treatment on the cell viability of human prostate cancer ***:Ellagic acid(10-100 mol/L) treatment(48 h) of human prostate carcinoma PC3 cells was found to result in a dose-dependent inhibition of cell growth and apoptosis of PC3 cells as assessed by MTT assay,western *** cytometry and confocal ***:We observed that ellagic acid treatment of PC3 cells resulted in a dose dependent inhibition of cell growth/cell *** ellagic acid caused cell growth inhibition was found to be accompanied by induction of apoptosis,as assessed by the cleavage of poly (ADP-ribose) polymerase(PARP) and morphological ***,induction of apoptosis accompanied a decrease in the levels of antiapoptotic protein Bcl-2 and increase in proapoptotic protein *** shifting the Bax:Bcl-2 ratio in favor of *** acid treatment of PC3 cells was also found to result in significant activation of caspases,as shown by the dose dependent decrease in the protein expression of procaspase-3,-6.-8 and -*** ellagic acid-mediated induction of apoptosis was significantly(80%-90%) inhibited by the caspase inhibitor N-benzyloxycarbonyl-Val-Ala-Asp(OMe)-fluoromethylketone(Z-VAD-FMK).Thus these data suggested an essential role of caspases in ellagic acid-mediated apoptosis of PC3 ***:It is tempting to suggest that consumption of tropical pigmented fruits and vegetables could be an effective strategy to combat prostate cancer.

关键词： Ellagic acid Apoptosis Prostate cancer Caspases

Assessment of alpine summit flora in Kashmir Himalaya and its implications for long-term monitoring of climate change impacts

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Mountain Science 2020年第8期17卷 1974-1988页

作者： Maroof HAMID Anzar Ahmad KHUROO akhtar Hussain MALIK Rameez AHMAD Chandra Prakash SINGH Centre for Biodiversity&Taxonomy Department of BotanyUniversity of KashmirSrinagar-190006J&KIndia Space Applications Centre Indian Space Research OrganizationAhmedabad-380015India

In an era of climate change,the availability of empirical data on alpine summit vegetation in the Himalaya is still *** we report the assessment of alpine summit flora in Gulmarg Wildlife Sanctuary,Kashmir *** employed a globally standardized Multi-Summit Approach and four spatially isolated summits spanning an elevation gradient of 210 m(between 3530-3740 m a.s.l.)from natural treeline to nival zone were *** of the summits was carried out in the year 2018 to collect floristic data together with records of soil temperature.A total of 142 vascular plant species were recorded in the sampled *** of the species were of herbaceous growth form and with perennial life *** on Raunkiaer’s life form,hemicryptophytes were the most dominant followed by therophytes and *** summit flora showed the predominance of narrow-endemic species,with broad-and non-endemics declining with elevation.A significant relationship between growth form,Raunkiaer’s life form,and the degree of endemism with elevation was *** species diversity and soil temperature showed a monotonic decrease with increasing ***,soil temperature clearly determined the magnitude of species diversity on the ***,based on floristic composition,the lowest summit had the highest dissimilarity with the rest of the *** present study employed globally standardized protocol to scientifically assess the patterns of plant diversity on the alpine mountain summits of Kashmir Himalaya,which in turn has wide implications towards long-term monitoring of climate change impact on alpine biodiversity in the rapidly warming Himalaya.

关键词： Alpine ecosystem Elevation gradient Endemism Himalaya Mountain summits

Silica-supported Thionyl Chloride-assisted Synthesis and Bioassay of Novel Tetrazinan-3-thione and 3-Oxo-pyrazolidine-4-carbonitrile Derivatives of Steroids

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2014年第1期30卷 55-62页

作者： PARVEEN Mehtabl MALLA Ali Mohammed ALl akhtar ALAM Mahboob MUSTAFA Mir Faisal Department of Chemistry Aligarh Muslim University Aligarh 202002 India Department of Biochemistry Aligarh Muslim University Aligarh 202002 India

A series of tetrazinan-3-thione and 3-oxo-pyrazolidine-4-carbonitrile derivatives of steroids（1-3） were synthesized with silica-chloride as a heterogeneous *** synthesized compounds 4-9 were obtained in substantial *** vitro evaluation of anticancer and antioxidant activity of the synthesized compounds was carried out via 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyltetrazolium bromide（MTT） and 1,1-diphenyl-2-picrylhydrazyl（DPPH）assays,*** 6 exhibited promising anti-proliferative activity towards a panel of cancer cell *** significant activity of compound 6 was further ascertained on structural,molecular modelling and docking *** study may provide a valuable insight into the further design and development of more potent biologically active compounds.

关键词： Steroid Biological evaluation Molecular docking

Optimization of Steel Bar Manufacturing Process Using Six Sigma

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2016年第2期29卷 332-341页

作者： NAEEM Khawar ULLAH Misbah TARIQ Adnan MAQSOOD Shahid akhtar Rehman NAWAZ Rashid HUSSAIN Iftikhar Department of Industrial Engineering University of Engineering and Technology(UET) Peshawar

Optimization of a manufacturing process results in higher productivity and reduced wastes. Production parameters of a local steel bar manufacturing industry of Pakistan is optimized by using six Sigma-Define, measure, analyze, improve, and controlmethodology. Production data is collected and analyzed. After analysis, experimental design result is used to identify significant factors affecting process performance. The significant factors are controlled to optimized level using two-level factorial design method. A regression model is developed that helps in the estimation of response under multi variable input values. Model is tested, verified, and validated by using industrial data collected at a local steel bar manufacturing industry of Peshawar（Khyber Pakhtunkhwa, Pakistan）. The sigma level of the manufacturing process is improved to 4.01 from 3.58. The novelty of the research is the identification of the significant factors along with the optimum levels that affects the process yield, and the methodology to optimize the steel bar manufacturing process.

关键词： steel bar manufacturing industry six sigma yield sigma level design of experiments

Large-Scale Expensive Optimization with a Switching Strategy

在线全文

学校读者我要写书评

暂无评论

Complex System Modeling and Simulation 2022年第3期2卷 253-263页

作者： Mai Sun Chaoli Sun Xiaobo Li Guochen Zhang Farooq akhtar School of Computer Science and Technology Taiyuan University of Science and TechnologyTaiyuan 030024China Department of Computer Sciences and Information Technology University of Kotli Azad Jammu and KashmirKotli 11100Pakistan

Some optimization problems in scientific research,such as the robustness optimization for the Internet of Things and the neural architecture search,are large-scale in decision space and expensive for objective *** order to get a good solution in a limited budget for the large-scale expensive optimization,a random grouping strategy is adopted to divide the problem into some low-dimensional sub-problems.A surrogate model is then trained for each sub-problem using different strategies to select training data *** that,a dynamic infill criterion is proposed corresponding to the models currently used in the surrogate-assisted sub-problem ***,an escape mechanism is proposed to keep the diversity of the *** performance of the method is evaluated on CEC’2013 benchmark *** results show that the algorithm has better performance in solving expensive large-scale optimization problems.

关键词： large-scale optimization problems computationally expensive problems random grouping surrogate models

Nanodiamond films deposited at moderate temperature on pure titanium substrate pretreated by ultrasonic scratching in diamond powder suspension

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of University of Science and Technology Beijing 2006年第6期13卷 542-545页

作者： Syed Jawid Askari Fanxiu Lv akhtar Farid Fengying Wang Qi He Zuyuan Zhou Materials Science and Engineering School University of Science and Technology Beijing Beijing 100083 China ES Department PNEC PNS Jauhar National University of Sciences ＆ Technology Karachi-75350 Pakistan

Nanocrystalline diamond （NCD） film deposition on pure titanium and Ti alloys is extraordinarily difficult because of the high diffusion coefficient of carbon in Ti, the large mismatch in their thermal expansion coefficients, the complex nature of the interlayer formed during diamond deposition, and the difficulty to achieve very high nucleation density. In this investigation, NCD films were successfully deposited on pure Ti substrate by using a novel substrate pretreatment of ultrasonic scratching in a diamond powder-ethanol suspension and by a two-step process at moderate temperature. It was shown that by scratching with a 30-μm diamond suspension for 1 h, followed by a 10-h diamond deposition, a continuous NCD film was obtained with an average grain size of about 200 nm. Detailed experimental results on the preparation, characterization, and successful deposition of the NCD films on Ti were discussed.

关键词： nanocrystalline diamond film pure Ti substrate nucleation enhancement moderate temperature