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Journal of Environmental Science and Engineering(B) 2017年第2期6卷 80-83页

作者： Vu ngoc Pi Tran Thi Phuong Thao Dang anh Tuan Mechanical Engineering Faculty Thai Nguyen University of Technology Thai Nguyen 250000 Vietnam

This paper presents a study on optimum determination of partial ratios of mechanical drive systems using a chain drive and two-step helical gearbox for getting minimum size of the system. The chosen objective function was the cross section dimension of the system. In solving the optimization problem, the design equation for pitting resistance of a gear set was investigated and equations on moment equilibrium condition of a mechanic system including a chain drive and two helical gear units and their regular resistance condition were analyses. From the results of the study, effective formulas for determination of the partial ratios of the chain drive and two-step helical gearboxes were introduced. As the formulas are explicit, the partial ratios can be calculated accurately and simply.

关键词： Gearbox design optimum design helical gearbox chain drive transmission ratio.

Contributions of Rotation,Expansion and Line Broadening to the Morphology and Kinematics of the Inner CSE of Oxygen-rich AGB Star R Hya

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Research in Astronomy and Astrophysics 2023年第1期23卷 40-47页

作者： Pham Tuyet Nhung Do Thi Hoai Pierre Darriulat Pham ngoc Diep Nguyen Bich ngoc Tran Thi Thai Pham Tuan-anh Department of Astrophysics Vietnam National Space CenterVietnam Academy of Science and Technology18Hoang Quoc VietNghia DoCau GiayHa NoiVietnam

We use archival ALMA observations of the CO(2-1)and SiO(5-4)molecular line emissions of AGB star R Hya to illustrate the relative contributions of rotation,expansion and line broadening to the morphology and kinematics of the circumstellar envelope(CSE)within some~70 au(~0."5)from the centre of the *** give evidence for rotation and important line broadening to dominate the inner region,within~14 au(~100 mas)from the centre of the *** former is about an axis that projects a few degrees west of north and has a projected rotation velocity of a few km s^(-1).The latter occurs within some 7-14 au(50-100 mas)from the centre of the star,with the line width reaching two to three times its value outside this *** suggest that it is caused by shocks induced by stellar pulsations and convective cell *** show the importance of properly accounting for the observed line broadening when discussing rotation and evaluating the radial dependence of the rotation velocity.

关键词： stars AGB and post-AGB-(stars:)circumstellar matter-radio lines

Characteristics of Suspended Particulate Matter and the Coastal Turbidity Maximum Areas of the Mekong River

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Journal of Environmental Science and Engineering(A) 2015年第2期4卷 67-78页

作者： Vu Duy Vinh Tran anh Tu Tran Dinh Lan Nguyen ngoc Tien Institute of Marine Environment and Resources Vietnam Academy of Science and Technology Haiphong 35999 Vietnam Institute of Marine Geology and Geophysics Vietnam Academy of Science and Technology Hanoi 10999 Vietnam

This paper presents the results of application of a 3D （three-dimensional） numerical model to study on MTZ （maximum turbidity zone） in the coastal zone of Mekong River Delta. In this study, a 3D system model with combination of hydrodynamics--wave and suspended sediment transport was set up and validated with measured data in the study area. Based on calculated scenarios for the flood and the dry season, the results have shown appearance of MTZs in the coastal zone of Mekong River with suspended sediment concentration prevalent of 0.04-0.07 kg·m^3 （the dry season） and 0.05-0.1kg·m^3 （the flood season）. The position and MTZs scale change with the interaction between fresh water and tidal oscillations. The MTZ occur more in the dry seasons compared to the wet season. The MTZs are prevalent located far away from estuaries about in 12-22 km （in the dry season）, and 5-15 km in the flood season.

关键词： Modelling maximum turbidity zone suspended sediment transport Me Kong river coastal area.

Development of 24 and 59 keV Filtered Neutron Beams for Neutron Capture Experiments at Dalat Research Reactor

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World Journal of Nuclear Science and Technology 2014年第2期4卷 59-64页

作者： Pham ngoc Son Vuong Huu Tan Phu Chi Hoa Tran Tuan anh Nuclear Research Institute Dalat Vietnam The University of Dalat Dalat Vietnam Vietnam Agency for Radiation and Nuclear Safety Hanoi Vietnam

External filtered neutron beams have been developed at the horizontal radial channels No. 4 of Dalat research reactor. In the material composition of the neutron filters, the primary material components of Iron, Aluminum, Nickel and Vanadium are used to obtain the mono-energetic neutron beams of 24 and 59 keV, with low level of Gamma and slow neutron background. A computer code and Monte-Carlo simulation technique were applied to optimize the filter configurations and to deduce the neutron energy distributions in the filtered beams. A hydrogen-filled proton recoil detector and the activation method with Gold foils were used to measure the neutron energy spectrum and flux of each beam at sample position. The results of experimental neutron fluxes are 6.1 × 105 and 5.3 × 105 n/cm2/s for 24 and 59 keV beams, respectively.

关键词： Research Reactor Filtered Neutron 24 keV 59 keV

Cost Optimization of Internal Grinding

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材料科学与工程（中英文B版） 2016年第6期6卷 291-296页

作者： Vu ngoc Pi Le Xuan Hung Luu anh Tung Banh Tien Long Thai Nguyen University of Technology Thai Nguyen 23000 Vietnam Ha Noi University of Technology Ha Noi 100000 Vietnam

Cost Optimization of Surface Grinding Process

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Journal of Environmental Science and Engineering(A) 2016年第12期5卷 606-611页

作者： Vu ngoc Pi Luu anh Tung Le Xuan Hung Banh Tien Long Thai Nguyen University of Technology Thai Nguyen 23000 Vietnam Ha Noi University of Technology Ha Noi 100000 Vietnam

This paper introduces a new study on cost optimization of surface grinding. In the study, the effects of grinding parameters including the dressing regime parameters, the wheel life and the initial grinding wheel diameter on the exchanged grinding wheel diameter which were investigated. In addition, the influence of cost parameters including the machine tool hourly rate and the grinding wheel cost were taken into account. In order to find the optimum exchanged grinding wheel diameter, a cost optimization problem was built. From the results of the optimization problem, a model for determination of the optimum exchanged grinding wheel diameter was found. By using the optimum diameter, both the grinding cost and grinding time can be reduced significantly.

关键词： Grinding grinding process surface grinding cost optimization.

Applying Molecular Breeding to Improve Soybean Rust Resistance in Vietnamese Elite Soybean

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American Journal of Plant Sciences 2013年第1期4卷 1-6页

作者： Tran Dang Khanh Truong Quoc anh bui Chi Buu Tran Dang Xuan 2Institute of Agricultural Science for Southern Vietnam Ho Chi Minh City Vietnam Department of Molecular Biology Agricultural Genetics Institute Hanoi Vietnam Graduate School for International Development and Cooperation Hiroshima University Hiroshima Japan Institute of Agricultural Science for Southern Vietnam Ho Chi Minh City Vietnam

Soybean production in Vietnam has recently been threatened by the widespread dissemination of soybean rust (SBR) caused by the fungus Phakopsora pachyrhizi. Application of molecular breeding is considered as a feasible method to improve soybean rust resistance and minimize the adverse effects from overuse fungicides in this country. In this study, we have successfully applied molecular markers in a backcross breeding program to introgress the Rpp5 gene of SBR resistance into HL203, an elite Vietnamese soybean variety, from two donor lines of DT2000 and Stuart 99084B-28. The plants in BC4F1 generation had maximum contribution from the recurrent parents and retained SBR resistance gene.

关键词： Rust Resistant Gene Soybean Marker Assisted Selection Molecular Marker

Formulation Optimization Utilizing D-Optimal Experimental Design of Oral Capsules Containing Enteric-Coated Pellets of Lansoprazole and<i>in vivo </i>Bioequivalence

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Pharmacology & Pharmacy 2017年第5期8卷 153-171页

作者： anh Quang Luong Thang ngoc Vu Dang Hoa Nguyen Sultan M. Alshahrani John Mark Christensen Chien ngoc Nguyen Department of Pharmacy National Institute of Burns Hanoi Vietnam Research and Training Center for Pharmacy Military Medical University Hanoi Vietnam Military Institute of Pharmaceutical Analysis and Research Hanoi Vietnam Department of Pharmaceutics Hanoi University of Pharmacy Hanoi Vietnam Department of Pharmaceutical Sciences College of Pharmacy Oregon State University Corvallis Oregon USA National Institute of Pharmaceutical Technology Hanoi University of Pharmacy Hanoi Vietnam

An optimized formulation of capsules containing Lansoprazole enteric-coated pellets using D-Optimal design with a polynomial statistical model were prepared by using Eudragit?L100 as an enteric coated polymer to provide resistance to simulated gastric acid dissolution in buffer media. D-Optimal experimental design was used to determine the optimal level for three coating layers that were applied to formulate the enteric-coated pellets including a drug loading layer, a sub-coating, and an outer enteric coating. Dissolution studies were performed on the prepared Lansoprazole capsules. Less than 5 percent of Lansoprazole was released in 60 minutes in an acidic dissolution medium (pH 1.2) and greater than 90 percent of active ingredient was released in the next 60 minutes in a buffer dissolution medium (pH 6.8). The Lansoprazole capsules were stable with no observable change in physico-chemical properties in accelerated and normal storage conditions for 6 and 18 months, respectively. The pharmacokinetic parameters Cmax, Tmax, AUC0-t, and AUC0-∞ were determined after administration of the D-Optimal design optimized capsules of LPZ to healthy beagle dogs and were statistically compared to Gastevin? capsules as a reference (KRKA, Slovenia) using the non-compartmental method with the aid of WinNonlin 5.2 software. The analysis of variance showed that the two formulations did not demonstrate bioequivalence using a 90% confidence interval range (80% - 120%) of Cmax, AUC0-t, and AUC0-∞. No significant difference in Tmax was found at the 0.95 significance level using the Wilcoxon signed-rank test. D-Optimal Experimental Design provided definitive direction for an optimal formulation of capsules containing enteric-coated pellets of lansoprazole loaded within the coating of pellets that provided similar bioequivalence to Gastevin.

关键词： Lansoprazole D-Optimal Pellets Enteric-Coating Pharmacokinetic Parameters

Development and Application of a Distributed Conceptual Hydrological Model to Simulate Runoff in the Be River Basin and the Water Transfer Capacity to the Saigon River Basin,Vietnam

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Journal of Environmental Science and Engineering(A) 2020年第1期9卷 1-12页

作者： Vu Van Nghi Ha bui Nguyen Lam Tai Pham anh Can Thu Van Institute for Computational Science and Technology Ho Chi Minh City 700000Vietnam University of Science Vietnam National UniversityHo Chi Minh City 700000Vietnam Dalat University Lam Dong Province 66000Vietnam Institute for Science and Technology Innovation Ho Chi Minh City 700000Vietnam Ho Chi Minh City University of Natural Resources and Environment Ho Chi Minh City 700000Vietnam

A distributed conceptual model(FRASC(Flow Routed Accumulation Simulation in a Catchment))has been developed,in which a rainfall-runoff module is modified from an original lumped conceptual model(Xinanjiang)via a GIS(Geographic Information System)-aided approach and a water allocation module contains reservoirs,water users and hydropower *** model is relatively easy to use and can easily obtain input data,but still has the ability to generate hydrological information at many points within a *** model application to the Be River basin is evaluated and shows to be reliable in terms of close agreements between simulated and observed *** natural flow rates for 36 years are simulated at 7,981 grid cells within a studied area of 7,650 km^*** on this simulated database,design discharges are predicted in various ***,the research determines that the water transfer capacity from the Be River basin to the Saigon River basin reaches 14%,18% and 23% of a planned value of 75 m^3/s during the dry period in a wet year(P10%),average year(P50%)and dry year(P90%),respectively.

关键词： Be River basin distributed conceptual hydrological model FRASC

Morphology of the ^(13)CO(3–2) millimetre emission across the gas disc surrounding the triple protostar GG Tau A using ALMA observations

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Research in Astronomy and Astrophysics 2018年第3期18卷 63-76页

作者： Nguyen Thi Phuong Pham ngoc Diep Anne Dutrey Edwige Chapillon Pierre Darriulat Stéphane Guilloteau Do Thi Hoai Pham Tuyet Nhung Ya-Wen Tang Nguyen Thi Thao Pham Tuan-anh Department of Astrophysics Vietnam National Space CenterVietnam Academy of Science and Technology Graduate University of Science and Technology Vietnam Academy of Science and Technology Laboratoire d’Astrophysique de Bordeaux Université de Bordeaux IRAM F-38406 Saint Martin d’Hères Cedex Academia Sinica Institute of Astronomy and Astrophysics

Observations by the Atacama Large Millimetre/sub-millimetre Array of the dust continuum and ^13 CO（3–2） millimetre emissions of the triple stellar system GG Tau A are analysed,giving evidence for a rotating gas disc and a concentric and coplanar dust ring. The present work complements an earlier analysis（Tang et al.） by exploring detailed properties of the gas disc. A 95% confidence level upper limit of 0.24＂（34 au） is placed on the disc scale height at a distance of 1＂（140 au） from the central stars. Evidence for Keplerian rotation of the gas disc is presented,with the rotation velocity reaching-3.1 km s^-1 at 1＂ from the central stars,and a 99% confidence level upper limit of 9% is placed on relative contribution from a possible in-fall velocity. Variations of the intensity across the disc area are studied in detail and confirm the presence of a hot spot in the south-eastern quadrant. However several other significant intensity variations,in particular a depression in the northern direction,are also revealed. Variations of the intensity are found to be positively correlated to variations of the line width. Possible contributions to the measured line width are reviewed,suggesting an increase of the disc temperature and opacity with decreasing distance from the stars.

关键词： protoplanetary disks - stars low-mass - stars individual (GG Tau A)