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Tracer gas measurement and simulation of turbulent diffusion in mine ventilation airways

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Journal of Coal Science & Engineering(China) 2008年第4期14卷 523-529页

作者： ARPA Gabriel widiatmojo arif WIDODO Nuhindro Priagung SASAKI Kyuro Department of Earth Resources Engineering Kyushu UniversityFukuoka 819-0383Japan Department of Mining Engineering Institute Teknologi BandungBandung 40132Indonesia

The effective diffusion coefficients in mine ventilation-flows had been obtained as 4 to 200 m^2/s by matching the measured concentration-time curves with the advec- tion-diffusion *** turbulent diffusion coefficients in the simple airways have good agreement with the equation proposed by ***,for complex airways in operat- ing mines,the evaluated effective diffusion coefficients in the mines show higher values than that calculated by the Taylor's equation.A numerical simulation model using with movements of discrete particles dosed into ventilation flows has been developed to simu- late diffusion phenomena of gas or dust in mine *** simulations had been conducted on distribution of tracers in single airways with ordinary profiles of mean velocity velocity fluctuations and Reynolds *** one of results,long band of diffused particles is obtained at the single airway of 600 m in length,and large effective diffusion coefficient is evaluated as 20 m^2/s.

关键词：绘图工作测量法矿山模拟

Discrete Tracer Point Method to Evaluate Turbulent Diffusion in Circular Pipe Flow

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Journal of Flow Control, Measurement & Visualization 2013年第2期1卷 57-68页

作者： arif widiatmojo Kyuro Sasaki Nuhindro Priagung Widodo Yuichi Sugai Department of Earth Resources Engineering Faculty of Engineering Kyushu University Fukuoka Japan Department of Mining Engineering Faculty of Mining and Petroleum EngineeringInstitut Teknologi Bandung Bandung Indonesia

Diffusion of a solute in turbulent flows through a circular pipe or tunnel is an important aspect of environmental safety. In this study, the diffusion coefficient of turbulent flow in circular pipe has been simulated by the Discrete Tracer Point Method (DTPM). The DTPM is a Lagrangian numerical method by a number of imaginary point displacement which satisfy turbulent mixing by velocity fluctuations, Reynolds stress, average velocity profile and a turbulent stochastic model. Numerical simulation results of points’ distribution by DTPM have been compared with the analytical solution for turbulent plug-flow. For the case of turbulent circular pipe flow, the appropriate DTPM calculation time step has been investigated using a constantβ, which represents the ratio between average mixing lengths over diameter of circular pipe. The evaluated values of diffusion coefficient by DTPM have been found to be in good agreement with Taylor’s analytical equation for turbulent circular pipe flow by givingβ=0.04 to 0.045. Further, history matching of experimental tracer gas measurement through turbulent smooth-straight pipe flow has been presented and the results showed good agreement.

关键词： Discrete Tracer Point Method (DTPM) Turbulent Diffusion Pipe Numerical Simulation Airflow

A review on edge analytics:Issues,challenges,opportunities,promises,future directions,and applications

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Digital Communications and Networks 2024年第3期10卷 783-804页

作者： Sabuzima Nayak Ripon Patgiri Lilapati Waikhom arif Ahmed National Institute of Technology Silchar India Ericsson Sweden

Edge technology aims to bring cloud resources(specifically,the computation,storage,and network)to the closed proximity of the edge devices,i.e.,smart devices where the data are produced and *** computing and application in edge devices lead to emerging of two new concepts in edge technology:edge computing and edge *** analytics uses some techniques or algorithms to analyse the data generated by the edge *** the emerging of edge analytics,the edge devices have become a complete ***,edge analytics is unable to provide full support to the analytic *** edge devices cannot execute advanced and sophisticated analytic algorithms following various constraints such as limited power supply,small memory size,limited resources,*** article aims to provide a detailed discussion on edge *** key contributions of the paper are as follows-a clear explanation to distinguish between the three concepts of edge technology:edge devices,edge computing,and edge analytics,along with their *** addition,the article discusses the implementation of edge analytics to solve many problems and applications in various areas such as retail,agriculture,industry,and ***,the research papers of the state-of-the-art edge analytics are rigorously reviewed in this article to explore the existing issues,emerging challenges,research opportunities and their directions,and applications.

关键词： Edge analytics Edge computing Edge devices Big data Sensor Artificial intelligence Machine learning Smart technology Healthcare

A Hybrid SIR-Fuzzy Model for Epidemic Dynamics:A Numerical Study

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Computer Modeling in Engineering & Sciences 2024年第6期139卷 3417-3434页

作者： Muhammad Shoaib arif Kamaleldin Abodayeh Yasir Nawaz Department of Mathematics and Sciences College of Humanities and SciencesPrince Sultan UniversityRiyadh11586Saudi Arabia Department of Mathematics Air UniversityIslamabad44000Pakistan

This study focuses on the urgent requirement for improved accuracy in diseasemodeling by introducing a newcomputational framework called the Hybrid SIR-Fuzzy *** integrating the traditional Susceptible-Infectious-Recovered(SIR)modelwith fuzzy logic,ourmethod effectively addresses the complex nature of epidemic dynamics by accurately accounting for uncertainties and imprecisions in both data and model *** main aim of this research is to provide a model for disease transmission using fuzzy theory,which can successfully address uncertainty in mathematical *** main emphasis is on the imprecise transmission rate parameter,utilizing a three-part description of its membership *** enhances the representation of disease processes with greater complexity and tackles the difficulties related to quantifying uncertainty in mathematical *** investigate equilibrium points for three separate scenarios and perform a comprehensive sensitivity analysis,providing insight into the complex correlation betweenmodel parameters and epidemic *** order to facilitate a quantitative analysis of the fuzzy model,we propose the implementation of a resilient numerical *** convergence study of the scheme demonstrates its trustworthiness,providing a conditionally positive solution,which represents a significant improvement compared to current forward Euler *** numerical findings demonstrate themodel’s effectiveness in accurately representing the dynamics of disease ***,when the mortality coefficient rises,both the susceptible and infected populations decrease,highlighting the model’s sensitivity to important epidemiological ***,there is a direct relationship between higher Holling type rate values and a decrease in the number of individuals who are infected,as well as an increase in the number of susceptible *** correlation offers a significant understanding of how many elements affect the con

关键词： Fuzzy-based model sensitivity equilibriumpoints proposed numerical scheme convergence and stability analysis

Construction of a Computational Scheme for the Fuzzy HIV/AIDS Epidemic Model with a Nonlinear Saturated Incidence Rate

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Computer Modeling in Engineering & Sciences 2024年第2期138卷 1405-1425页

This work aimed to construct an epidemic model with fuzzy *** the classical epidemic model doesnot elaborate on the successful interaction of susceptible and infective people,the constructed fuzzy epidemicmodel discusses the more detailed versions of the interactions between infective and susceptible ***-generation matrix approach is employed to find the reproduction number of a deterministic *** analysis and local stability analysis of the systemare also *** solving the fuzzy epidemic model,a numerical scheme is constructed which consists of three time *** numerical scheme has an advantage overthe existing forward Euler scheme for determining the conditions of getting the positive *** establishedscheme also has an advantage over existing non-standard finite difference methods in terms of order of *** stability of the scheme for the considered fuzzy model is also *** the plotted results,it can beobserved that susceptible people decay by rising interaction parameters.

关键词： Epidemic model fuzzy rate parameters next generation matrix local stability proposed numerical scheme

Optimizing Optical Fiber Faults Detection:A Comparative Analysis of Advanced Machine Learning Approaches

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Computers, Materials & Continua 2024年第5期79卷 2697-2721页

作者： Kamlesh Kumar Soothar Yuanxiang Chen arif Hussain Magsi Cong Hu Hussain Shah School of Electronics Engineering Beijing University of Posts and TelecommunicationsBeijing100876China State Key Laboratory of Integrated Services Networks Xidian UniversityXi’an710071China State Key Laboratory ofNetworking and Switching Technology Beijing University of Posts and TelecommunicationsBeijing100876China

Efficient optical network management poses significant importance in backhaul and access network communicationfor preventing service disruptions and ensuring Quality of Service(QoS)*** emerging faultsin optical networks introduce challenges that can jeopardize the network with a variety of *** existingliterature witnessed various partial or inadequate *** the other hand,Machine Learning(ML)hasrevolutionized as a promising technique for fault detection and *** traditional fault managementsystems,this research has three-fold ***,this research leverages the ML and Deep Learning(DL)multi-classification system and evaluates their accuracy in detecting six distinct fault types,including fiber cut,fibereavesdropping,splicing,bad connector,bending,and PC ***,this paper assesses the classificationdelay of each classification ***,this work proposes a fiber optics fault prevention algorithm thatdetermines to mitigate the faults *** work utilized a publicly available fiber optics dataset namedOTDR_Data and applied different ML classifiers,such as Gaussian Naive Bayes(GNB),Logistic Regression(LR),Support Vector Machine(SVM),K-Nearest Neighbor(KNN),Random Forest(RF),and Decision Tree(DT).Moreover,Ensemble Learning(EL)techniques are applied to evaluate the accuracy of various *** addition,this work evaluated the performance of DL-based Convolutional Neural Network and Long-Short Term Memory(CNN-LSTM)hybrid *** findings reveal that the CNN-LSTM hybrid technique achieved the highestaccuracy of 99%with a delay of 360 *** the other hand,EL techniques improved the accuracy in detecting fiberoptic ***,this research comprehensively assesses accuracy and delay metrics for various classifiers andproposes the most efficient attack detection system in fiber optics.

关键词： Fiber optics fault detection multiclassification machine learning ensemble learning

Experiments Using Capillary Mat as Ground Heat Exchanger for Ground Source Heat Pump Heating Application

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Energy and Power Engineering 2019年第11期11卷 363-378页

作者： arif widiatmojo Shrestha Gaurav Takeshi Ishihara Akira Tomigashi Kasumi Yasukawa Youhei Uchida Shohei Kaneko Mayumi Yoshioka Renewable Research Center National Institute of Advanced Industrial Science and Technology Koriyama Japan Japan Oil Gas and Metals National Corporation (JOGMEC) Tokyo Japan

The cooling and heating of spaces are among the largest sources for household’s energy demand. Ground Source Heat Pump (GSHP) is a promising technology to reduce the energy for cooling and heating purposes. However, the major obstacle hindering the utilization of this technology is the high initial cost, especially for the installation of ground coupled heat exchanger. The horizontal closed-loop system offers lower installation cost, as it requires no vertical borehole construction. Instead, the heat exchangers can be installed in shallow trenches that may be excavated, by small excavator or even by human labor. This paper presents the comparison of two different heat exchangers, namely, the capillary mat and the widely used slinky pipe. Both heat exchangers are connected to a heat pump, where continuous heating tests were carried out for 165 hours (~7 days) for each configuration. The purpose of this research is to show the performance of capillary mat in comparison to slinky pipe. Despite during the entire test for capillary mat required 6% higher electricity consumption, compared to slinky heat exchanger, the results still suggest the potential use of capillary mat as alternative to slinky heat exchanger. Additionally, the results also highlight the high hydraulic resistance of installed capillary mat heat exchangers may become the major disadvantage of the capillary mat.

关键词： Horizontal Heat Exchanger Ground Source Heat Pump Capillary Mat

Highly selective adsorption of rhenium by amyloid-like protein material

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Science China(Technological Sciences) 2024年第5期67卷 1417-1430页

作者： MUHAMMAD arif YANG QingMin KANWAL Aisha ZHAO Jian NAWAZ Mohsan REN Hao YANG Peng Key Laboratory of Applied Surface and Colloid Chemistry Ministry of Education Xi’an Key Laboratory of Polymeric Soft Matter International Joint Research Center on Functional Fiber and Soft Smart TextileSchool of Chemistry and Chemical EngineeringShaanxi Normal UniversityXi’an710119China School of Chemistry and Chemical Engineering Northwestern Polytechnical UniversityXi’an710072China

Rhenium separation from molybdenum in molybdenite minerals and waste leachate has become an emerging *** this challenge,we prepared a set of protein-based alkylamine/alkylammonium salts complexes as extractants for selective uptake of rhenium from molybdenum,where the protein component turned into the insoluble amyloid-like structure when its internal disulfide bonds were reduced,namely phase-transition *** them,the phase-transited lysozyme and methyletrioctyleammonium chloride complex(PTL-N263)exhibited the most efficient adsorption at the alkaline condition for the electrostatic interaction between negatively charged metal ions with positively charged center(R_(4)N^(+))in N263,where negatively charged protein residues hindered the ion exchange of Cl^(-)in N263 for larger size Mo species(Mo_(7)O_(24)^(6-))than smaller size Re species(ReO^(4-)).The adsorption follows the Freundlich model and pseudo-second-order kinetics,which exhibits toplevel adsorption performance with a maximum adsorption capacity of 124 mg/g and a separation factor(β_(Re/Mo))of 2.78×10^(3)for *** adsorption capacity per unit area(57.2 mg/(g m^(2)))is 1.6–41 times higher than previously reported adsorbents,and the cost for adsorbing 1 g of Re(VII)is$1.07,indicating its industrial *** adsorption strategy can be applied to separating Re from Mo in binary solutions and industrial wastewater with other competing ions.

关键词： amyloid phase-transited lysozyme selective adsorption rhenium waste leachate solution

Deferred revascularization in diabetic patient according to combined invasive functional and intravascular imaging data:A case report

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World Journal of Clinical Cases 2024年第13期12卷 2269-2274页

作者： arif Al Nooryani Wael Aboushokka Branko Beleslin Biljana Nedeljkovic-Beleslin Department of Cardiology Al Qassimi HospitalSharjah 1234United Arab Emirates Department of Cardiology Medical FacultyUniversity of BelgradeBelgrade 11000Serbia Institute of Endocrinology Diabetes and Metabolic DisordersUniveristy Clinical Center of SerbiaBelgrade 11000Serbia Department of Internal Medicine/Endocrinology Medical facultyUniversity of BelgradeBelgrade 11000Serbia

BACKGROUND Invasive functional evaluation by fractional flow reserve(FFR)is considered as a gold standard for the evaluation of intermediate coronary ***,in patients with diabetes due to accelerated progression of atherosclerosis the outcome may be worse even in the presence of negative functional *** SUMMARY We present a case of 55-year-old male diabetic patient who was admitted for chest *** coronary angiography disclosed 2 intermediate stenoses of the obtuse marginal branch with no evidence of restenosis on previously implanted *** undergone invasive functional testing of intermediate lesion with preserved FFR(0.88),low coronary flow reserve(1.2)and very high index of microvascular resistance(84).Due to discrepancy in invasive functional parameters,intravascular imaging with optical coherence tomography showed fibrotic stenoses without signs of thin-sup *** of the preserved FFR and no signs of vulnerable plaque,the interventional procedure was deferred and the patient continued with optimal *** Combined functional and anatomic imaging of intermediate coronary stenosis in diabetic patients represent comprehensive contemporary decision pathway in the management of the patients.

关键词： Fractional flow reserve Coronary flow reserve Index of microvascular resistance Optical coherence tomography Intermediate coronary stenosis Case report