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International Journal of Coal Science & Technology 2020年第3期7卷 560-570页

作者： Thanh Viet nguyen Khanh Duc nguyen nang Xuan Ho Vinh Duy nguyen Department of Internal Combustion Engine School of Transportation EngineeringHanoi University of Science and TechnologyHanoiViet Nam Faculty of Vehicle and Energy Engineering Phenikaa UniversityYen NghiaHa-Dong DistrictHanoiViet Nam

Biodiesels produced from various feedstocks have been considered as alternative fuels used in internal combustion engines without major *** research focuses on producing biodiesel from waste cooking oil(WCOSD)by the catalytic cracking method using MgO as the catalyst and comparing the engine operating characteristics of the test engine when using WCOSD and traditional diesel(CD)as test *** a result,the brake power of the test engine fueled WCOSD,and traditional diesel is ***,the engine fuel consumption in the case of using WCOSD is slight increases in some operating ***,the nitrogen oxides emissions of the test engine fueled WCOSD are higher than those of CD at all tested *** trend is opposite for hydrocarbon emission as the HC emission of the engine fueled by WCOSD reduces 26.3%on *** smoke emission of the test engine in case of using WCOSD is lower 17%on average than that of ***,the carbon monoxide emissions are lower at the low and medium loads and higher at the full *** results show that the new biodiesel has the same characteristics as those of commercial biodiesel and can be used as fuel for diesel engines.

关键词： Feedstock Waste cooking oil Engine characteristics Exhaust missions Ignition timing Fuel consumption

An analytical model for cross-Kerr nonlinearity in a four-level N-type atomic system with Doppler broadening

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Chinese Physics B 2022年第2期31卷 314-319页

作者： dinh Xuan Khoa nguyen Huy Bang nguyen Le Thuy An nguyen Van Phu Le Van Doai Vinh University 182 Le Duan StreetVinh CityVietna

We present an analytical model for cross-Kerr nonlinear coefficient in a four-level N-type atomic medium under Doppler *** model is applied to87 Rb atoms to analyze the dependence of the cross-Kerr nonlinear coefficient on the external light field and the temperature of atomic *** analysis shows that in the absence of electromagnetically induced transparency(EIT)the cross-Kerr nonlinear coefficient is zero,but it is significantly enhanced when the EIT is *** means that the cross-Kerr effect can be turned on/off when the external light field is on or ***,the amplitude and the sign of the cross-Kerr nonlinear coefficient are easily changed according to the intensity and frequency of the external light *** amplitude of the cross-Kerr nonlinear coefficient remarkably decreases when the temperature of atomic medium *** analytical model can be convenient to fit experimental observations and applied to photonic devices.

关键词： electromagnetically induced transparency Kerr nonlinear effect Doppler effect

Thermal Performance Prediction in the Air Gap of a Rotor-Stator Configuration: Effects of Numerical Models

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Journal of Thermal Science 2020年第1期29卷 206-218页

作者： DANG dinh-Dong PHAM Xuan-Tan nguyen Chi-Cong Department of Mechanical Engineering École de technologie supérieureMontrealQCCanada Hydro-Québec’s research institute VarennesQCCanada

This study is dedicated to a numerical investigation of convective heat transfer on the rotor surfaces of a rotor-stator configuration that is typically found in large *** computational fluid dynamics calculations with two turbulence modelling approaches are used to predict the flow structure and heat transfer in the air gap of the rotor-stator *** steady state mixing plane approach is employed at the interface to couple the rotor and stator *** show that the location of mixing plane interface in the air gap plays an important role in the prediction of heat transfer on the pole ***,it is indicated that the prediction of temperature distribution on the pole face is greatly affected by the turbulence models ***,through a comparison between the pure convective and conjugate heat transfer methodologies,it is shown that the inclusion of solid domain into the numerical model significantly improves the thermal prediction of the solid components of the machine.

关键词： hydro-generators electrical cooling mixing plane windage loss conjugate heat transfer

Long-Term Improvement in Precautions for Flood Risk Mitigation:A Case Study in the Low-Lying Area of Central Vietnam

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International Journal of Disaster Risk Science 2021年第2期12卷 250-266页

作者： Cong dinh nguyen Funiikazu Ubukata Quang Tan nguyen Hoang Ha Vo Graduate School of Environmental and Life Science Okayama UniversityOkayama 700-8530Japan Faculty of Economics and Development Studies University of EconomicsHue UniversityHue City 49000Vietnam International School Hue UniversityHue City 49000Vietnam

Local actors appear as inseparable components of the integrated flood risk mitigation strategy in *** this fact,this study examined the long-term improvement in precautions taken by commune authorities and households between two major floods in 1999 and 2017 by applying both quantitative and qualitative *** flood-prone villages were selected for a survey;one in a rural area and the other in a suburban area of Thua Thien Hue Province,central *** findings indicate that most villagers doubted the structural works’efficacy and were dissatisfied with the current efforts of local ***’self-preparation thus became the decisive factor in mitigating *** most households have paid greater attention to flood precautions in 2017,others seem to be ***-related barriers were the root causes restraining households in both rural and suburban *** suburban riverine residents were further identified as vulnerable by their limitations in upgrading structural measures,which was ascribed to the inconsistency in the ancient town’s preservation *** multidimensional comparison,in terms of vulnerability,emphasized the importance of space-function links in the suburb and the contradictions of different policy initiatives,such as landscape rehabilitation,disaster prevention,and livelihood maintenance.

关键词： Central Vietnam Flood risk mitigation Long-term improvement Natural hazards Precautionary measures

Regularization of the Inverse Problem for Time Fractional Pseudo-parabolic Equation with Non-local in Time Conditions

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Acta Mathematica Sinica,English Series 2022年第12期38卷 2199-2219页

作者： nguyen Duc PHUONG Le dinh LONG Anh Tuan nguyen Dumitru BALEANU Faculty of Fundamental Science Industrial University of Ho Chi Minh CityVietnam Division of Applied Mathematics Science and Technology Advanced InstituteVanLang UniversityHoChi Minh CityVietnam Faculty of Technology Van Lang UniversityHo Chi Minh CityVietnam Department of Mathematics Cankaya UniversityAnkaraTurkey Lebanese AmericanUniversity BeirutLebanon Institute of Space Sciences Magurele-BucharestRomania

This paper is devoted to identifying an unknown source for a time-fractional diffusion equation in a general bounded ***,we prove the problem is non-well posed and the stability of the source ***,by using the Modified Fractional Landweber method,we present regularization solutions and show the convergence rate between regularization solutions and sought solution are given under a priori and a posteriori choice rules of the regularization parameter,***,we present an illustrative numerical example to test the results of our theory.

关键词： Source problem fractional pseudo-parabolic problem ill-posed problem convergence estimates regularization

Effect of three tree species on UV weathering of wood flour-HDPE composites

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Journal of Forestry Research 2020年第3期31卷 1071-1079页

作者： Van dinh nguyen Tat Thang nguyen Aihong Zhang Jianxiu Hao Weihong Wang Key Laboratory of Biobased Material Science&Technology(Ministry of Education) Northeast Forestry UniversityHarbin 150040China

Eucalyptus urophylla, Acacia mangium, and Pinus caribaea are the primary species for the wood industry in Vietnam. Wood residues of these species were used to reinforce high-density polyethylene(HDPE) composites. The flexural or bending property, impact strength and surface color were evaluated after exposure to accelerated ultraviolet weathering up to 2000 h. The weathered surface was characterized by scanning electron microscopy(SEM) and Fourier transform infrared(FTIR) spectroscopy. The results indicate that A. mangium/HDPE composites had the lowest color change and least fading,and remained stable after 1500 h exposure. FTIR spectroscopy showed that the oxidation of the composites increased in parallel with duration of exposure by assessing the concentration of carbonyl groups on the surfaces. SEM showed that all three species reinforced composites exhibited similar severe cracks after 1000 h;however, at the end of the weathering test, E. urophylla and P. caribaea composites were more severely cracked than A. mangium composites. A. mangium also had the highest flexural strength, impact strength and crystallinity duringweathering. A. mangium is the most preferable among the three species to reinforce HDPE.

关键词： Eucalyptus urophylla Acacia mangium Pinus caribaea Polyethylene Weathering Color Mechanical property

Metagenomic markings of myeloid malignancies

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Genes & Diseases 2023年第1期10卷 4-6页

作者： An dinh Duy nguyen Maryssa Shanteau-Jackson Thomas LaFramboise Department of Genetics and Genome Sciences School of MedicineCase Western Reserve UniversityClevelandOH44106USA

Human microbiome studies have exploded in number in recent years with the advent of high-throughput sequencing *** dramatic increase in sensitivity facilitated by deep-sequencing capability has led to hundreds of studies characterizing microbial communities in multiple human tissues,as well as the relationships between the composition of these communities and disease.

关键词： methods. myeloid hundreds

Rotational Forms of Large Eddy Simulation Turbulence Models:Modeling and Mathematical Theory

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Chinese Annals of Mathematics,Series B 2021年第1期42卷 17-40页

作者： Luigi C.BERSELLI Roger LEWANDOWSKI dinh Duong nguyen Universita di Pisa Dipartimento di MatematicaVia Buonarroti 1/c1-56127 Pisa Italy IRMAR UMR CNRS 6625University of Rennes 1 and FLUMINANCE TeamINRIA RennesFrance

In this paper the authors present a derivation of a back-scatter rotational Large Eddy Simulation model,which is the extension of the Baldwin&Lomax model to nonequilibrium *** model is particularly designed to mathematically describe a fluid filling a domain with solid walls and consequently the differential operators appearing in the smoothing terms are degenerate at the *** the derivation of the model,the authors prove some of the mathematical properties coming from the weighted energy estimates,which allow to prove existence and uniqueness of a class of regular weak solutions.

关键词： Fluid mechanics Turbulence models Rotational Large Eddy Simulation models Navier-Stokes equations

A Note on Skew Cyclic Codes over a Class of Rings

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Algebra Colloquium 2020年第4期27卷 703-712页

作者： Hai Q.dinh Bac T.nguyen Songsak Sriboonchitta Division of Computational Mathematics and Engineering Institute for Computational Science Ton Due Thang University Ho Chi Minh CityVietnam Faculty of Mathematics and Statistics Ton Due Thang University Ho Chi Minh CityVietnam Department of Basic Sciences University of Economics and Business Administration Thai Nguyen UniversityThai Nguyen ProvinceVietnam Centre of Excellence in Econometrics Faculty of Economics Chiang Mai UniversityChiang Mai 52000Thailand

We study skew cyclic codes over a class of rings R=F0■F1■⋯■Ft−1,where each Fi(i=0,…,t−1)is a finite *** prove that a skew cyclic code of arbitrary length over R is equivalent to either a usual cyclic code or a quasi-cyclic code over ***,we discuss possible extension of our results in the more general setting ofδR-dual skew constacyclic codes over R,whereδR is an automorphism of R.

关键词： skew constacyclic codes dual codes repeated-root codes quasi-cyclic codes local rings

Blockchain for Education:Verification and Management of Lifelong Learning Data

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Computer Systems Science & Engineering 2022年第11期43卷 591-604页

作者： Ba-Lam Do Van-Thanh nguyen Hoang-Nam dinh Thanh-Chung Dao BinhMinh nguyen School of Information and Communication Technology Hanoi University of Science and TechnologyHanoiVietnam

In recent years,blockchain technology has been applied in the educational domain because of its salient advantages,i.e.,transparency,decentralization,and *** systems typically use public blockchain networks such as Ethereum and Bitcoin to store learning ***,the cost of writing data on these networks is significant,making educational institutions limit data sent to the target network,typically containing only hash codes of the issued *** this paper,we present a system based on a private blockchain network for lifelong learning data authentication and management named B4E(Blockchain For Education).B4E stores not only certificates but also learners’training data such as transcripts and educational programs in order to create a complete record of the lifelong education of each user and verify certificates that they have *** a result,B4E can address two types of fake certificates,i.e.,certificates printed by unlawful organizations and certificates issued by educational institutions for learners who have not met the training *** addition,B4E is designed to allow all participants to easily deploy software packages to manage,share,and check stored information without depending on a single point of *** such,the system enhances the transparency and reliability of the stored *** experiments show that B4E meets expectations for deployment in reality.

关键词： Training data certificate verification and management private blockchain