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GPGPU-parallelised hybrid finite-discrete element modelling of rock chipping and fragmentation process in mechanical cutting

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Journal of Rock Mechanics and Geotechnical Engineering 2020年第2期12卷 310-325页

作者： Mojtaba Mohammadnejad sevda dehkhoda Daisuke Fukuda Hongyuan Liu Andrew Chan School of Engineering College of Science and EngineeringUniversity of TasmaniaHobartTAS7001Australia CSIRO Minerals Resources Business UnitQCAT 1 Technology CourtPullenvaleQLD4069Australia Hatch BrisbaneQLD4000Australia Division of Sustainable Resources Engineering Faculty of EngineeringHokkaido UniversityHokkaidoJapan

Mechanical cutting provides one of the most flexible and environmentally friendly excavation *** has attracted numerous efforts to model the rock chipping and fragmentation process,especially using the explicit finite element method(FEM) and bonded particle model(BPM),in order to improve cutting *** study investigates the application of a general-purpose graphic-processing-unit parallelised hybrid finite-discrete element method(FDEM) which enjoys the advantages of both explicit FEM and BPM,in modelling the rock chipping and fragmentation process in the rock scratch test of mechanical rock *** input parameters of FDEM are determined through a calibration procedure of modelling conventional Brazilian tensile and uniaxial compressive tests of limestone,A series of scratch tests with various cutting velocities,cutter rake angles and cutting depths is then modelled using FDEM with calibrated input parameters.A few cycles of cutter/rock interactions,including their engagement and detachment process,are modelled for each case,which is conducted for the first time to the best knowledge of the authors,thanks to the general purpose graphic processing units(GPGPU) *** failure mechanism,cutting force,chipping morphology and effect of various factors on them are discussed on the basis of the modelled ***,it is concluded that GPGPU-parallelised FDEM provides a powerful tool to further study rock cutting and improve cutting efficiencies since it can explicitly capture different fracture mechanisms contributing to the rock chipping as well as chip formation and the separation process in mechanical ***,it is concluded that chipping is mostly owed to the mix-mode Ⅰ-Ⅱ fracture in all cases although mode Ⅱ cracks and mode Ⅰ cracks are the dominant failures in rock cutting with shallow and deep cutting depths,*** chip morphology is found to be a function of cutter velocdty,cutting depth and cutter rake angl

关键词： Numerical simulation Finite-discrete element method(FDEM) Rock cutting Chipping Cracking

On power series statistical convergence and new uniform integrability of double sequences

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Applied Mathematics(A Journal of Chinese Universities) 2024年第3期39卷 519-532页

作者： sevda Y■ld■z Kamil Demirci Sinop University Department of MathematicsSinopTurkey

In the present paper,we mostly focus on P_(p)^(2)-statistical *** will look into the uniform integrability via the power series method and its characterizations for double ***,the notions of P_(p)^(2)-statistically Cauchy sequence,P_(p)^(2)-statistical boundedness and core for double sequences will be described in addition to these findings.

关键词： power series methods statistical convergence uniform integrability double sequences

Effect of environmental factors on species diversity of the Yenice Hot Spot Forests in Turkey

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Journal of Forestry Research 2018年第6期29卷 1719-1730页

作者： sevda Turkis Emire Elmas Faculty of Education Ordu UniversityOrduTurkey Faculty of Science and Art Sinop UniversitySinopTurkey

We quantified the diversity of vascular plant species and described soil properties and topographical and climatic conditions of the Citdere and Kavakli Nature Reserves in the Yenice Forest of Turkey. We used the Shannon-Weiner and Simpson's indices of diversity,Margalef's index of species richness and Pielou's evenness index to quantify the structure of vascular plant assemblages. We measured soil parameters(NO_3^-, NH_4^+,available P, Mg^(++), K^+, Na^+, Ca^(++), organic matter, pH,soil moisture), elevation, slope gradient and aspect and their correlations with plant community parameters. In total, we recorded and identified 207 species and subspecies in the study area. Species cover, richness and diversity indices varied significantly by vegetation type(P < 0.01). Available NO_3^- and Ca++ in the soil were important factors for the area and species representation in the species-environment correlations estimated for the Kavakli area. Available NO_3^-,pH, organic matter, Ca^(++) and K^+ in the soil were important factors for the area and species representation in the species-environment correlations analysed for the Citdere area.

关键词： Diversity Forest ecosystems Yenice hotspot Species richness

A narrative overview of utilizing biomaterials to recapitulate the salient regenerative features of dental-derived mesenchymal stem cells

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International Journal of Oral Science 2021年第2期13卷 117-128页

作者： sevda Pouraghaei Sevari Sahar Ansari Alireza Moshaverinia Weintraub Center for Reconstructive Biotechnology Division of Advanced ProsthodonticsSchool of DentistryUniversity of CaliforniaLos AngelesLos AngelesCAUSA California NanoSystems Institute University of CaliforniaLos AngelesLos AngelesCAUSA

Tissue engineering approaches have emerged recently to circumvent many limitations associated with current clinical *** elegant approach utilizes a natural/synthetic biomaterial with optimized physiomechanical properties to serve as a vehicle for delivery of exogenous stem cells and bioactive factors or induce local recruitment of endogenous cells for in situ tissue *** by the natural microenvironment,biomaterials could act as a biomimetic three-dimensional(3D)structure to help the cells establish their natural *** a strategy should not only employ a biocompatible biomaterial to induce new tissue formation but also benefit from an easily accessible and abundant source of stem cells with potent tissue regenerative *** human teeth and oral cavity harbor various populations of mesenchymal stem cells(MSCs)with self-renewing and multilineage differentiation *** the current review article,we seek to highlight recent progress and future opportunities in dental MSC-mediated therapeutic strategies for tissue regeneration using two possible approaches,cell transplantation and cell ***,this paper develops a general picture of current innovative strategies to employ dental-derived MSCs combined with biomaterials and bioactive factors for regenerating the lost or defective tissues and offers information regarding the available scientific data and possible applications.

关键词： biomaterials utilizing utilize

Real-time Energy Management of Grid-connected Microgrid with Flexible and Delay-tolerant Loads

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Journal of Modern Power Systems and Clean Energy 2020年第6期8卷 1196-1207页

作者： sevda Zeinal-Kheiri Amin Mohammadpour Shotorbani Behnam Mohammadi-Ivatloo IEEE the Faculty of Electrical and Computer Engineering University of TabrizTabrizIran the School of Engineering University of British Columbia OkanaganKelownaCanada the Institute of Research and Development Duy Tan UniversityDa NangVietnam

For optimal operation of microgrids,energy management is indispensable to reduce the operation cost and the emission of conventional *** goals can be impeded by several factors including uncertainties of market price,renewable generation,and ***-time energy management system(EMS)can effectively address uncertainties due to the online information of market price,renewable generation,and ***,some issues arise in real-time EMS as batterylimited energy *** this paper,Lyapunov optimization is used to minimize the operation cost of the microgrid and the emission of conventional ***,the problem is multiobjective and a Pareto front is derived to compromise between the operation cost and the *** a modified IEEE 33-bus distribution system,general algebraic modeling system(GAMS)is utilized for implementing the proposed EMS on two case studies to verify its applicability.

关键词： Battery energy management system(EMS) flexible and delay-tolerant load Lyapunov optimization microgrid optimal power flow renewable generation

Comparison via Digital Radiography of Radiopacity Levels of Composite Materials with Various Shades and Viscosities

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Journal of Wuhan University of Technology(Materials Science) 2022年第2期37卷 170-176页

作者： Gunce Ozan Oktay Yazicioglu Hidir Tatar sevda Ozel Yildiz Istanbul University Faculty of Dentistry Dept.of Restorative Dentistry Haseki Education and Research Hospital Istanbul University Faculty of Medicine Dept.of Biostatistics

Aim of the present in vitro study is to evaluate the radiopacity levels of composite resins with various shades and viscosity.10 mm×2 mm discs were prepared from 7 condensable and 4 flowable composites(n=10).An aluminum step wedge ranging from 2.0 to 10.0 mm in thickness was placed on the occlusal *** radiographs were taken using a dental X-ray device and radiographic densities of each step of the aluminum wedge and the samples were recorded to the *** readings were taken and means were ***-Way Anova and Tamhane post hoc tests were *** G-eanial Posterior has the highest radiopacity value followed by Filtek Z550,Aelite Flo has the lowest radiopacity *** composites show higher radiopacity and flowable composites with higher filler loadings have superior radiopacity levels to condensable *** and body shades of the composite brands have also statistically significant differences in radiopacity ***,radiopacity level of a composite resin material is not affected by the size of fillers;however,the composition,shape and loading of the fillers can specify the radiodensity.

关键词： radiopacity composite resins digital radiography flowable composites shade

HIGHLY OSCILLATORY DIFFUSION-TYPE EQUATIONS

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Journal of Computational Mathematics 2013年第6期31卷 549-572页

作者： sevda Uskiiplii Altlnbasak Marissa Condon Alfredo Deano Arieh Iserles Department of Applied Mathematics and Theoretical Physics Centre for Mathematical Sciences University of Cambridge Cambridge UK School of Electronic Engineering Dublin City University Dublin Ireland Department of Mathematics University Carlos III de Madrid Madrid Spain Department of Applied Mathematics and Theoretical Physics Centre for Mathematical Sciences University of Cambridge Cambridge UK

We explore new asymptotic-numeric solvers for partial differential equations with highly oscillatory forcing terms. Such methods represent the solution as an asymptotic series, whose terms can be evaluated by solving non-oscillatory problems and they guarantee high accuracy at a low computational cost. We consider two forms of oscillatory forcing terms, namely when the oscillation is in time or in space： each lends itself to different treatment. Numerical examples highlight the salient features of the new approach.

关键词： Diffusion-type PDEs High oscillation Asymptotic expansions Modulated Fourier expansions.

Soil chronosequence and biosequence on old lake sediments of the Burdur Lake in Turkey

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Pedosphere 2021年第6期31卷 882-891页

作者： Gafur GOZUKARA Yakun ZHANG Alfred EHARTEMINK sevda ALTUNBAS Mustafa SARI Department of Soil Science and Plant Nutrition Eskisehir Osmangazi UniversityEskisehir 26160(Turkey) Department of Soil Science FD Hole Soils Lab1525 Observatory DriveUniversity of Wisconsin-MadisonMadison 53706(USA) Department of Soil Science and Plant Nutrition Akdeniz UniversityAntalya 07059(Turkey)

The Burdur Lake is located in the southwest of Turkey,and its area has decreased by 40% from 211 km^(2) in 1975 to 126 km^(2) in *** this study,we investigated how the soil has changed in the lacustrine *** soil profiles were sampled from the former lakebed(chronosequence profiles:P1,2007;P2,1994;and P3,1975),and three soil profiles under different land use types(biosequence profiles:P4,native forest vegetation;P5,agriculture;and P6,lakebed)were *** chronosequence and biosequence soil profiles represented various distances from the Burdur Lake and showed different stages of lacustrine *** electrical conductivity(EC;18.1 to 0.4 dS m^(-1)),exchangeable Na^(+)(34.7 to 1.4 cmol kg^(-1))and K^(+)(0.61 to 0.56 cmol kg^(-1)),and water-soluble Cl^(-)(70.3 to 2.1 cmol L^(-1))and SO_(4)^(2-)(275.9 to 25.0 cmol L^(-1))decreased with increasing distance from the Burdur Lake,whereas the A horizon thickness(10 to 48 cm),structure formation(0 to 48 cm),gleization-oxidation depth(0 to 79 cm),and montmorillonite and organic matter(OM;25.9 to 46.0 g kg^(-1))contents increased in the chronosequence soil *** formation of P3 in the chronosequence and P5 in the biosequence soil profiles increased due to longer exposure to pedogenic processes(time,land use,vegetation,etc.).Changes in EC,exchangeable cation(Na^(+) and K^(+))and water-soluble anion(Cl^(-) and SO_(4)^(2-))concentrations of the salt-enriched horizon,OM,gleization-oxidation depth,A horizon thickness,and structure formation of the chronosequence and biosequence soil profiles(especially the topsoil horizon)were highly related to the distance from the Burdur Lake,time,and land use.

关键词： biosequence soil profile chronosequence soil profile lacustrine material lakebed soil formation

Levels of vocational satisfaction,burnout and compassion fatigue of health professionals working in pediatric clinics

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World Journal of Clinical Pediatrics 2022年第1期11卷 38-47页

作者： Oğuz Koyuncu sevda Arslan Department of Nursing Sakarya Training and Research HospitalSakarya 0080DüzceTurkey Department of Nursing Düzce University Faculty of Health SciencesMerkez 81100DüzceTurkey

BACKGROUND Burnout and compassion fatigue are affecting the quality of professional *** To investigate the levels of vocational satisfaction,burnout,and compassion fatigue and factors that may be related to health professionals working in children’s *** The study sample was in the west of *** were collected using the questionnaire form and the quality of life scale for *** The findings obtained in this study showed that the level of vocational satisfaction of female health professionals and the burnout level of male health professionals were *** professional satisfaction of the doctors was lower than that of the nurses and midwives,and the mean score of burnout and fatigue was *** Further studies are needed on this topic to help improve the factors that may affect the professional quality of life of health professionals.

关键词： Health professionals Professional life quality Professional satisfaction Burnout Compassion fatigue