检索结果-南通市图书馆

Molybdenite alkali fusion and leaching:reactions and mechanism

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2010年第2期17卷 127-131页

作者： Reza Ebrahimi-Kahrizsangi mohammad hasan abbasi Ali Saidi Department of Materials Engineering Islamic Azad University Department of Materials Engineering Isfahan University of Technology

The production of MoO3 from Sarcheshmeh molybdenite concentrate via a pyro-hydrometallurgical process was *** molybdenite concentrate and sodium carbonate were premixed and fused under air *** the fused products were leached in water and the dissolved molybdenum was recovered as ammonium *** ammonium molybdate was then calcined to produce mo-lybdic *** the fusion stage,the effect of the mass ratio of carbonate to sulfide on the reaction products and the solubility of the products was *** results show that during the fusion,sodium molybdate and sodium sulfate are the final reaction products and sodium sulfide is detected as an intermediate reaction *** melting at 850℃with 5wt%excess carbonate,the maximum solubility of the products is *** molybdenum is recovered from the solutions as ammonium molybdate.

关键词： molybdenite alkali fusion leaching sodium molybdate molybdic oxide

Characterization of NbSi_2–Al_2O_3 nanocomposite coatings prepared with plasma spraying mechanically alloyed powders

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2015年第7期22卷 748-754页

作者： Zohreh Yazdani Fathallah Karimzadeh mohammad-hasan abbasi Abbas Amini Department of Materials Engineering Isfahan University of Technology

The present study characterized NbSi2-Al2O3 nanocomposite powders plasma-sprayed on Ti-6Al-4Vsubstrates. The powders were agglomerated to obtain suitable particle sizes for spraying. The agglomerated powders were then plasma-sprayed using atmospheric plasma spraying. The structural transformations of the powders along with the morphological and mechanical changes of the coatings were examined by X-ray diffraction, scanning electron microscopy, energy dispersive spectroscopy, transmission electron microscopy, and hard- ness testing. The results showed that after plasma spraying, the grain size increased, and the lattice strain decreased. However, the grain size of this compound after spraying was still in the nanometer range. The coating was uniform and exhibited good adhesion to the substrate. The microhardness and fracture toughness of the nanocomposite coating were higher than those of a nanostructured NbSi2 coating.

关键词： nanocomposites coatings plasma spraying mechanical alloying

Randomization Strategies in Image Steganography Techniques:A Review

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第8期80卷 3139-3171页

作者： AFM Zainul Abadin Rossilawati Sulaiman mohammad Kamrul hasan Center for Cyber Security Faculty of Information Science and TechnologyUniversiti Kebangsaan Malaysia(UKM)BangiSelangor43600Malaysia Department of Information and Communication Engineering Pabna University of Science and TechnologyPabna6600Bangladesh

Image steganography is one of the prominent technologies in data hiding *** system performance mostly depends on the embedding *** goal is to embed strictly confidential information into images without causing perceptible changes in the original *** randomization strategies in data embedding techniques may utilize random domains,pixels,or region-of-interest for concealing secrets into a cover image,preventing information from being discovered by an *** implementation of an appropriate embedding technique can achieve a fair balance between embedding capability and stego image imperceptibility,but it is challenging.A systematic approach is used with a standard methodology to carry out this *** review concentrates on the critical examination of several embedding strategies,incorporating experimental results with state-of-the-art methods emphasizing the robustness,security,payload capacity,and visual quality metrics of the stego *** fundamental ideas of steganography are presented in this work,along with a unique viewpoint that sets it apart from previous works by highlighting research gaps,important problems,and ***,it offers a discussion of suggested directions for future study to advance and investigate uncharted territory in image steganography.

关键词： Information hiding image steganography randomized embedding techniques payload capacity imperceptibility

Detecting anomalies in blockchain transactions using machine learning classifiers and explainability analysis

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Blockchain(Research and Applications) 2024年第3期5卷 106-122页

作者： mohammad hasan mohammad Shahriar Rahman Helge Janicke Iqbal H.Sarker Department of Computer Science and Engineering Premier University4000 ChitagongBangladesh Department of Computer Science and Engineering United International University1212 DhakaBangladesh Cyber Security Cooperative Research Centre 6027 PerthAustralia Centre for Securing Digital Futures Edith Cowan University6027 PerthAustralia

As the use of blockchain for digital payments continues to rise,it becomes susceptible to various malicious *** detecting anomalies within blockchain transactions is essential for bolstering trust in digital ***,the task of anomaly detection in blockchain transaction data is challenging due to the infrequent occurrence of illicit *** several studies have been conducted in the field,a limitation persists:the lack of explanations for the model’s *** study seeks to overcome this limitation by integrating explainable artificial intelligence(XAI)techniques and anomaly rules into tree-based ensemble classifiers for detecting anomalous Bitcoin *** shapley additive explanation(SHAP)method is employed to measure the contribution of each feature,and it is compatible with ensemble ***,we present rules for interpreting whether a Bitcoin transaction is anomalous or ***,we introduce an under-sampling algorithm named XGBCLUS,designed to balance anomalous and non-anomalous transaction *** algorithm is compared against other commonly used under-sampling and over-sampling ***,the outcomes of various tree-based single classifiers are compared with those of stacking and voting ensemble *** experimental results demonstrate that:(i)XGBCLUS enhances true positive rate(TPR)and receiver operating characteristic-area under curve(ROC-AUC)scores compared to state-of-the-art under-sampling and over-sampling techniques,and(ii)our proposed ensemble classifiers outperform traditional single tree-based machine learning classifiers in terms of accuracy,TPR,and false positive rate(FPR)scores.

关键词： Anomaly detection Blockchain Bitcoin transactions Data imbalance Data sampling Explainable AI Machine learning Decision tree Anomaly rules

Robust design of sliding mode control for airship trajectory tracking with uncertainty and disturbance estimation

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 Systems Engineering and Electronics 2024年第1期35卷 242-258页

作者： WASIM Muhammad ALI Ahsan CHOUDHRY mohammad Ahmad SHAIKH Inam Ul hasan SALEEM Faisal Department of Aeronautics and Astronautics Engineering Institute of Space TechnologyIslamabad 44000Pakistan Department of Electrical Engineering University of Engineering and TechnologyTaxila 47080Pakistan Department of Measurements and Control Systems Silesian University of TechnologyGliwice 44-101Poland The Joint Doctoral School Silesian University of TechnologyGliwice 44-100Poland

The robotic airship can provide a promising aerostatic platform for many potential *** applications require a precise autonomous trajectory tracking control for *** has a nonlinear and uncertain *** is prone to wind disturbances that offer a challenge for a trajectory tracking control *** paper addresses the airship trajectory tracking problem having time varying reference path.A lumped parameter estimation approach under model uncertainties and wind disturbances is opted against distributed *** uses extended Kalman filter(EKF)for uncertainty and disturbance *** estimated parameters are used by sliding mode controller(SMC)for ultimate control of airship trajectory *** comprehensive algorithm,EKF based SMC(ESMC),is used as a robust solution to track airship *** proposed estimator provides the estimates of wind disturbances as well as model uncertainty due to the mass matrix variations and aerodynamic model *** stability and convergence of the proposed method are investigated using the Lyapunov stability *** simulation results show that the proposed method efficiently tracks the desired *** method solves the stability,convergence,and chattering problem of SMC under model uncertainties and wind disturbances.

关键词： airship chattering extended Kalman filter(EKF) model uncertainties estimation sliding mode controller(SMC)

Investigation of a solid particle deposition velocity in drag reducing fluids with salinity

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

PETROLEUM RESEARCH 2024年第3期9卷 347-358页

作者： Obi, Chinemerem Rahman, mohammad Azizur Hassan, Ibrahim hasan, Rashid Texas A&M Univ Doha Qatar Texas A&M Univ CS College Stn TX 77840 USA

Optimal and cost-effective drilling operations in extended-reach horizontal wells depend on efficient solid cuttings removal from the borehole. Several solids-suspended multiphase processes such as crude petroleum transportation, separation, and processing of oil and gas streams also require the efficient removal of these solids. The terminal settling velocity (V-ts) of the solid particle is a vital parameter that controls the removal efficiency of these solids. In a drilling scenario when there is a hold on fluid circulation such as connection time, the accurate estimation of V-s provides the driller with time available to prevent solid deposition. In severe conditions, this can result in a stuck pipe, especially for extended-reach horizontal wells. In this work, both spherical and non-spherical particle deposition were experimentally investigated in several fluid rheology and salinity. Two concentrations (0.1 vol% and 0.05 vol%.) of partially-hydrolyzed polyacrylamide (PHPA) were used as a drag-reducing additive for water-based drilling mud. The PHPA drag-reducing fluid (reduced pressure loss) acts as a turbulence inhibitor. The PHPA polymer chain suppresses any turbulence in the flow, reducing the turbulent eddy viscosity. The effects of salinity (3wt.%NaCl and 3wt.%CaCl2 contamination) on solid particle settling velocity (V-s) in drag-reducing fluids were also investigated. Terminal velocity was achieved for all experiments and seemed to increase with increased diameter/sphericity. However, cases when this trend was not consistent were observed and therefore a new parameter of Phi (sphericity index x diameter) was proposed. V-s increases with Phi value for all cases. During drilling, PHPA also aids in sealing the fracture in the formation. With and without salt in the fluid, how lowering drag affected the settling velocity of solid particles (drill cuttings) could be observed. The settling velocity tests will be improved in drag-reducing PHPA solutions with the

关键词： Deposition velocity Drag reducing fluids Salinity Visualization Drilling SETTLING VELOCITY TERMINAL VELOCITY COEFFICIENT WATER PREDICTION TRANSPORT BEHAVIOR FIBER FALL

Fatal cases in pediatric patients after post-exposure prophylaxis for rabies:A report of two cases

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Medicine 2024年第1期17卷 39-42页

作者： Hekmatollah Khoubfekr mohammad Jokar Vahid Rahmanian hasan Blouch mohammad Reza Shirzadi Rouzbeh Bashar Department of Public Health Iranshahr University of Medical SciencesIranshahrIran Faculty of Veterinary Medicine Karaj BranchIslamic Azad UniversityKarajIran Department of Public Health Torbat Jam Faculty of Medical SciencesTorbat JamIran Center for Communicable Diseases Control Ministry of Health and Medical EducationTehranIran WHO Collaborating Center for Reference and Research on Rabies Virology DepartmentPasteur Institute of IranTehranIran

Rationale:Rabies is a zoonotic disease with a high mortality,primarily transmitted through the bite of infected mammals,particularly dogs and *** being a well-known disease since ancient times,it continues to cause a significant number of human deaths worldwide,with approximately 65000 fatalities reported *** concerns:We present two fatal cases of rabies in a 12-year-old immigrant boy and a 7-year-old *** first case was subject to a 24-hour delay in receiving appropriate medical attention and rabies preventive measures due to the lack of awareness among emergency hospital staff,leading to the administration of wound dressing *** second case received timely rabies immunoglobulin administration;however,there was a 4-day delay in administering the fourth dose of the rabies vaccine,despite presenting evident symptoms of ***:Postmortem examination of brain samples from both patients confirmed the presence of rabies ***:Post-exposure prophylaxis for ***:Both patients were admitted to the hospital after the manifestation of rabies-related symptoms,with the 12-year-old child seeking medical care 47 days after the animal bite and the 7-year-old child seeking medical care 58 days after the ***,the first patient died after 27 days and the second patient died after 40 days of ***:There is an urgent need for heightened awareness and education among both healthcare professionals and the public regarding the urgency of seeking immediate medical attention after potential rabies *** recognition and initiation of post-exposure prophylaxis are pivotal in preventing the progression of the *** surveillance and reporting systems,coupled with continuous training for healthcare professionals,can contribute to early detection and management of rabies cases.

关键词： Rabies Encephalitis Pediatric patients Rabies prophylaxis Public health awareness

Performance Comparison of Hyper-V and KVM for Cryptographic Tasks in Cloud Computing

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第2期78卷 2023-2045页

作者： Nader Abdel Karim Osama A.Khashan Waleed K.Abdulraheem Moutaz Alazab hasan Kanaker Mahmoud E.Farfoura mohammad Alshinwan Department of Intelligent Systems Faculty of Artificial IntelligenceAl-Balqa Applied UniversityAl-Salt1705Jordan Research and Innovation Centers Rabdan AcademyP.O.Box 114646Abu DhabiUnited Arab Emirates Department of Information Systems and Networks TheWorld Islamic Sciences and Education UniversityAmman11947Jordan Department of Cyber Security Isra UniversityAmman1162Jordan Faculty of Science and Information Technology Al-Zaytoonah University of JordanAmman11733Jordan Middle East University Research Unit Middle East UniversityAmman11831Jordan

As the extensive use of cloud computing raises questions about the security of any personal data stored there,cryptography is being used more frequently as a security tool to protect data confidentiality and privacy in the cloud environment.A hypervisor is a virtualization software used in cloud hosting to divide and allocate resources on various pieces of *** choice of hypervisor can significantly impact the performance of cryptographic operations in the cloud *** important issue that must be carefully examined is that no hypervisor is completely superior in terms of performance;Each hypervisor should be examined to meet specific *** main objective of this study is to provide accurate results to compare the performance of Hyper-V and Kernel-based Virtual Machine(KVM)while implementing different cryptographic algorithms to guide cloud service providers and end users in choosing the most suitable hypervisor for their cryptographic *** study evaluated the efficiency of two hypervisors,Hyper-V and KVM,in implementing six cryptographic algorithms:Rivest,Shamir,Adleman(RSA),Advanced Encryption Standard(AES),Triple Data Encryption Standard(TripleDES),Carlisle Adams and Stafford Tavares(CAST-128),BLOWFISH,and *** study’s findings show that KVM outperforms Hyper-V,with 12.2%less Central Processing Unit(CPU)use and 12.95%less time overall for encryption and decryption operations with various file *** study’s findings emphasize how crucial it is to pick a hypervisor that is appropriate for cryptographic needs in a cloud environment,which could assist both cloud service providers and end *** research may focus more on how various hypervisors perform while handling cryptographic workloads.

关键词： Cloud computing performance virtualization hypervisors Hyper-V KVM cryptographic algorithm

Enhancing Ulcerative Colitis Diagnosis:A Multi-Level Classification Approach with Deep Learning

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2024年第7期140卷 1129-1142页

作者： hasan J.Alyamani Department of Information Systems Faculty of Computing and Information Technology in RabighKing Abdulaziz UniversityJeddah21589Saudi Arabia

The evaluation of disease severity through endoscopy is pivotal in managing patients with ulcerative colitis,a condition with significant clinical ***,endoscopic assessment is susceptible to inherent variations,both within and between observers,compromising the reliability of individual *** study addresses this challenge by harnessing deep learning to develop a robust model capable of discerning discrete levels of endoscopic disease *** initiate this endeavor,a multi-faceted approach is embarked *** dataset is meticulously preprocessed,enhancing the quality and discriminative features of the images through contrast limited adaptive histogram equalization(CLAHE).A diverse array of data augmentation techniques,encompassing various geometric transformations,is leveraged to fortify the dataset’s diversity and facilitate effective feature extraction.A fundamental aspect of the approach involves the strategic incorporation of transfer learning principles,harnessing a modified ResNet-50 *** augmentation,informed by domain expertise,contributed significantly to enhancing the model’s classification *** outcome of this research endeavor yielded a highly promising model,demonstrating an accuracy rate of 86.85%,coupled with a recall rate of 82.11%and a precision rate of 89.23%.

关键词： Ulcerative colitis deep learning CLAHE transfer learning geometric transformations