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Acta Metallurgica Sinica(English Letters) 2015年第1期28卷 122-128页

作者： Thang Van Le ha tran Nguyen Anh Tuan Luu Man Van tran Phung Loan My Le Faculty of Materials Technology Ho Chi Minh University of Technology 268 Ly Thuong Kiet Ward 14 District 10 Ho Chi Minh City Vietnam Department of Physical Chemistry University of Science VNUHCM 227 Nguyen Van Cu Street District 5 Ho Chi Minh CityVietnam

The demand of higher energy density and higher power capacity of lithium（Li）-ion secondary batteries has led to the search for electrode materials whose capacities and performance are better than those available today. Carbon nanotubes（CNTs）, with their unique properties such as 1D tubular structure, high electrical and thermal conductivities, and extremely large surface area, have been used as materials to prepare cathodes for Li-ion batteries. The structure and morphology of CNTs were analyzed by X-ray diffraction（XRD）, scanning electron microscopy（SEM）, and transmission electron microscopy（TEM）. The functional groups on the purified CNT surface such as –COOH, –OH were characterized by Fourier transform infrared spectroscopy. The electrode materials were fabricated from LiMn2O4（LMO）, doped spinel LiNi0.5Mn1.5O4, and purified CNTs via solid-state reaction. The structure and morphology of the electrode were characterized using XRD, SEM, and TEM. Finally, the efficiency of the electrode materials using CNTs was evaluated by cyclic voltammetry and electrochemical impedance spectroscopy.

关键词： Nanocomposites Carbon nanotubes(CNTs) Spinel materials Lithium-ion batteries(LIBs)

Identifying nursing research priorities in Vietnam: a modified Delphi study

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Frontiers of Nursing 2019年第4期6卷 249-259页

作者： Yupin Aungsuroch Xuan ha thi Nhu tran Thuy Khanh Linh Rapin Polsook Rungrawee Navicharern Joko Gunawan Faculty of Nursing Chulalongkorn UniversityPathumwanBangkok 10330Thailand Faculty of Nursing and Medical Technology University of Medicine and PharmacyHo Chi MinhDong Nai 70000Vietnam

Objective: There is no single study that has examined nursing research priorities in Vietnam. this study aimed to gain consensus from experts on the nursing research priorities in ***: A three-round modified Delphi study was used in this study. A focus group discussion among experts was conducted in round I to identify the nursing research priorities(n=23). Data in round I were analyzed using content analysis. In round Ⅱ, participants were invited to rate the importance of each nursing priority topic in a 5-point Likert scale questionnaire, which had a 74%(n=17) response rate. In round Ⅲ, the questionnaire was returned to the experts(n=17) until consensus was reached. Data from round Ⅱ and round Ⅲ were analyzed to produce mean score and final ***: The top 12 research priority lists were identified, which included subthemes and areas of possible investigations. All priorities were classified into three groups in the rank order, namely:(i) nursing management and leadership, which included(1) nursing care quality,(2) management and leadership of nurse managers,(3) nursing image,(4) professional nurse competency, and(5) human resource management;(ii) nursing education, which included(1) knowledge-specific domain,(2) the linkage between education and practice, and(3) nurse teacher workforce;and(iii) nursing service, which included(1) adult nursing concern,(2) patient safety,(3) public health nursing concern, and(4) quality of life of patients and ***: Consensus among experts was achiever, and the findings are considered as the basis of resources to the most essential research needs in Vietnam.

关键词： Delphi method research priorities nursing Vietnam

Monte Carlo simulation of a cone-beam CT system for lightweight casts

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Radiation Detection Technology and Methods 2021年第4期5卷 504-512页

作者： Thuy Duong tran Ngoc ha Bui Kim Tuan tran Ngoc Toan tran Department of Nuclear Engineering and Environmental Physics School of Engineering PhysicsHanoi University of Science and Technology01 Dai Co VietHai Ba TrungHanoiVietnam Vietnam Atomic Energy Institute 59 Ly Thuong KietHoan KiemHanoiVietnam

Cone-beam computed tomography(CBCT),a modern technique with many applications,is becoming increasingly important and essential in many areas of economics and *** equipment has been commercialized in both hardware and ***,having a device system suitable for a specific group of objects will be the *** work used Monte Carlo simulation to optimize the design of a Cone-beam Computed Tomography(CBCT)for lightweight and small-size *** affecting image quality such as radiation-source,flat-panel detector,and geometrical distance were *** results indicate that an X-ray generator with a focal spot size of 4×4µm^(2),high voltage of 240 kV,and a radiation intensity of 10^(13) photon/s with a flat panel CsI(Tl)detector of 0.3 mm thickness and a pixel size of 0.1–0.2 mm,is suitable for a CBCT to inspect small objects in *** Monte Carlo model was validated against experiments and to evaluate some characteristics of the existing system.

关键词： Cone-beam computed technology Monte Carlo simulation Lightweight casts in industry Applied radiation

Morbidity and Mortality of Acute Renal Failure in COVID-19 Patients in Intensive Care According to Waves/Variant: Case of the Grand Hôpital de l’Est Francilien Site de Meaux

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Open Journal of Internal Medicine 2024年第1期14卷 16-29页

作者： Khazy Anga Ariel Makembi Éric Amisi Éric Delpierre Vivien hong Tuan ha Wilfrid Mbombo Jean Claude Mubenga Dan Kankonde Chris Nsituavibidila Lionel Diyamona Noelly Mukuna Gracia Likinda Tharcisse Mabiala Martin Mukenga Médard Bula-Bula Berthe Barhayiga Département d’Anesthésie Réanimation Université de Kinshasa Kinshasa République démocratique du Congo Service de Réanimation Grand H&ocircpital de l’Est Francilien Meaux France Département de Médecine Interne Université de Kinshasa Kinshasa République démocratique du Congo Service d’Anesthésie Réanimation Centre Hospitalier Monkole Kinshasa République démocratique du Congo Department of Anaesthesia and Intensive Care H&ocircpital Général de Référence de Kinshasa Kinshasa République démocratique du Congo Department of Anaesthesia and Intensive Care Université Protestante du Congo Kinshasa République démocratique du Congo

Introduction: The incidence of acute renal failure (ARF) varies between 20% and 40% of cases for COVID-19 patients admitted to the intensive care unit, with very high mortality, but heterogeneous according to the different epidemic waves, probably due to the genetic variant phenomenon of the virus. The aim of this study is to determine the morbidity and mortality of COVID-19 patients admitted with ARF to the intensive care unit of the Grand H?pital Est Francilien (GHEF) according to the waves and variants. Methods: Cross-sectional observational study of COVID-19 patients with ARF admitted to the intensive care unit of the GHEF site in Meaux covering the period from March 1st 2020 to December, 31st 2021. Per-hospitalisation and outcome data were collected and analysed with SPSS version 25.0 software using the Chi-square or Fischer’s exact test or Student’s t-test and logistic regression for p Results: A total of 86 patients were included. The mean age was higher (70 ± 8.5) in patients in the fourth wave than in the other waves (p = 0.015), with male predominance in all waves without significant difference. Co-morbidities: hypertension, diabetes, heart disease, dyslipidaemia and arrhythmia complete with fibrillation were present in all waves. The majority of patients were classified as KDIGO 1 for the different waves (1st: 61.9%, 2nd: 86.5%, 3rd: 80%, and 4th: 75%), with the same trend according to variant (alpha: 80%, beta: 75%, delta: 81.3%, omicron: 75%). Mortality by the wave was: 1st: 28.5%, 2nd: 37.5%, 3rd: 23% and 4th: 11%) and by variant: alpha: 24.2%, beta: 44.8%, delta: 20.7%, omicron: 10.3%). Overall mortality was 33.7%. Case fatality was higher in the fourth wave. Hypertension, shock, failure to recover renal function, acute lung oedema, ventilator-associated lung disease and hyperkalaemia were factors associated with mortality (p Conclusion: Acute renal failure is common in COVID-19 patients admitted to the intensive care unit, and m

关键词： Mortality COVID-19 Morbidity Renal Failure Intensive Care Unit

Evaluation of Weathering Performance of Rosin-Copper Based Treated Wood

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Journal of Renewable Materials 2022年第11期10卷 2765-2780页

作者： thi Thanh Hien Nguyen Nho Quyet tran thi Minh Nguyet Nguyen Hien Mai Trinh Xuan Phuong Le Trong Kien Nguyen College of Wood Industry and Interior Design Vietnam National University of ForestryHa NoiViet Nam College of Economics and Management Northeast Forestry UniversityHarbinChina

this study aimed to evaluate the effect of natural weathering on some surface characteristics and mechanical properties of Styrax wood treated with mixtures of 1.0%,2.0%,or 4.0%rosin sizing agent and 3%copper *** samples after treatment were exposed to outdoor conditions for one year and changes in color,glossiness,weight loss,compression strength parallel to grain(CSPG),modulus of rupture(MOR),and modulus of elasticity(MOE)were investigated after 6 and 12-month of natural *** results showed that rosin-copper treatment could improve color stability and gloss of samples after *** losses of all rosin-copper treated samples after 12 months of exposure were negligible compared with the untreated control *** addition,rosin-copper treatment enhanced the CSPG compared to untreated controls,but slightly decreased the MOR and MOE of Styrax wood before *** weathering factors induced a reduction for all strength properties,however,the decrease rate for strength properties of rosin-copper treated samples was negligible compared with the untreated control samples after 12-month natural weathering *** FTIR and SEM-EDX confirmed that the use of the rosin-copper formulations to impregnate wood could decrease the hazard of the copper preservative leaching into the environment,while also enhancing more resistance against weathering factors and other biotic factors.

关键词： Rosin-copper weathering color stability CSPG MOR MOE

Enhanced wear resistance,antibacterial performance,and biocompatibility using nanotubes containing nano-Ag and bioceramics in vitro

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Bio-Design and Manufacturing 2024年第5期7卷 670-686页

作者： Qingge Wang Jia Liu hong Wu Jingbo Liu Yaojia Ren Luxin Liang Xinxin Yan Ian Baker Shifeng Liu V.V.Uglov Chengliang Yang Liqiang Wang State Key Laboratory of Powder Metallurgy Central South UniversityChangsha 410083China Affiliated Hospital of Youjiang Medical University for Nationalities Guangxi Key Laboratory for Preclinical and Translational Research on Bone and Joint Degenerative DiseasesGuangxi Zhuang Autonomous Region Engineering Research Center for Biomaterials in Bone and Joint Degenerative DiseasesGuangxi Key Laboratory for Biomedical Material ResearchBaise 533000China Department of Orthopedics The Second Xiangya HospitalCentral South UniversityChangsha 410011China Department of Orthopedics Renmin HospitalWuhan UniversityWuhan 430060China Thayer School of Engineering Dartmouth CollegeHanoverNH 03755-8000USA School of Metallurgical Engineering Xi’an University of Architecture and TechnologyXi’an 710055China Belarusian State University 220030 MinskBelarus State Key Laboratory of Metal Matrix Composites School of Material Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China

A good Ti-based joint implant should prevent stress shielding and achieve good bioactivity and anti-infection *** meet these requirements,the low-elastic-modulus alloy—Ti–35Nb–2Ta–3Zr—was used as the substrate,and functional coatings that contained bioceramics and Ag ions were prepared for coating on TiO_(2)nanotubes(diameter:(80±20)nm and(150±40)nm)using anodization,deposition,and spin-coating *** effects of the bioceramics(nano-β-tricalcium phosphate,microhydroxyapatite(micro-ha),and meso-CaSiO_(3))and Ag nanoparticles(size:(50±20)nm)on the antibacterial activity and the tribocorrosion,corrosion,and early in vitro osteogenic behaviors of the nanotubes were *** tribocorrosion and corrosion results showed that the wear rate and corrosive rate were highly dependent on the features of the nanotube ***-ha showed great wear resistance with a wear rate of(1.26±0.06)×10^(−3)mm^(3)/(N·m)due to adhesive and ***-CaSiO_(3)showed enhanced cell adhesion,proliferation,and alkaline phosphatase *** coatings that contained nano-Ag exhibited good antibacterial activity with an antibacterial rate of≥89.5%against Escherichia *** findings indicate that hybrid coatings may have the potential to accelerate osteogenesis.

关键词： βTi alloy Surface modification Wear resistance Corrosion resistance Osteogenic behavior Antibacterial activity

Ecoregional variations of aboveground biomass and stand structure in evergreen broadleaved forests

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Journal of Forestry Research 2020年第5期31卷 1713-1722页

作者： tran Van Do Mamoru Yamamoto Osamu Kozan Vo Dai hai Phung Dinh Trung Nguyen Toan Thang Lai Thanh hai Vu Thanh Nam Trieu Thai Hung Hoang Van Thang tran Duc Manh Cao Chi Khiem Vu Tien Lam Nguyen Quang Hung tran Hoang Quy Pham Quang Tuyen Trinh Ngoc Bon Nguyen thi Thu Phuong Ninh Viet Khuong Nguyen Van Tuan Dang thi hai ha tran hai Long Dang Van Thuyet Dang thinh Trieu Nguyen Van thinh tran Anh hai Duong Quang Trung Nguyen Van Bich Dinh hai Dang Pham Tien Dung Nguyen Huy Hoang Le thi hanh Phan Minh Quang Nguyen thi Thuy Huong Hoang Thanh Son Nguyen Thanh Son Nguyen thi Van Anh Nguyen thi Hoai Anh Pham Dinh Sam Hoang thi Nhung Hoang Van Thanh Nguyen Huu thinh tran hong Van Ho Trung Luong Bui Kieu Hung Research Institute for Sustainable Humanosphere Kyoto UniversityUjiKyotoJapan Silviculture Research Institute Vietnamese Academy of Forest SciencesNorth Tu LiemHanoiVietnam Center for Southeast Asian Studies Kyoto UniversityKyotoJapan Vietnamese Academy of Forest Sciences North Tu LiemHanoiVietnam Vietnam Administration of Forestry No.2 Ngoc HaBa DinhHanoiVietnam

Biotic and abiotic factors control aboveground biomass(AGB)and the structure of forest *** study analyses the variation of AGB and stand structure of evergreen broadleaved forests among six ecoregions of Vietnam.A data set of 1731-ha plots from 52 locations in undisturbed old-growth forests was *** results indicate that basal area and AGB are closely correlated with annual precipitation,but not with annual temperature,evaporation or hours of *** area and AGB are positively correlated with trees>30 cm *** areas surveyed(52.6%)in these old-growth forests had AGB of 100–200 Mg ha^-1;5.2%had AGB of 400–500 Mg ha^-1,and 0.6%had AGB of>800 Mg ha^-*** percent of the areas surveyed had stand densities of 300–600 ***^-1,and 64%had basal areas of 20–40 m^2 ha^-*** is an important factor influencing the AGB of old-growth,evergreen broadleaved forests in *** causing the loss of large-diameter trees(e.g.,>100 cm DBH)affects AGB but may not seriously affect stand density.

关键词： Aboveground biomass Carbon storage Climatic variables Ecoregion Edaphic variables Oldgrowth forest

Development of Precise Geoid Model for the Establishment of Consistent Height System in Geoga Grand Bridge Construction Area

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China Ocean Engineering 2009年第4期23卷 679-694页

作者： Dong-ha LEE hong-Sic YUN Department of Civil Architectural and Environmental System EngineeringSungkyunkwan University

The national benchmarks on islands were mostly established by trigonometric leveling in Korea. this method results in inaccuracy, which is a serious problem in Geoga Grand Bridge construction work that tried to link the mainland and the islands. The Geoga Grand Bridge （Pusan-Geoje fixed link project） was selected as the study area, a huge construction work in Korea that will connect the mainland （Pnsan） and an island （Gecje island）. However, the orthometric heights issued at benchmarks （JINH and GOFJ） were not consistent, because they did not refer to the same zero point, which would make the linking of the sections problematic. this paper introduces the precise local geoidas a vertical datum for the construction area in order to establish a consistent height system. To determine the precise local geoid for the construction area, we firstly developed a precise gravimetric geoid for Korea and its adjoining seas as a whole. this gravimetric geoid was developed by use of all available gravity data, including surface and satellite data on land and on the ocean. The gravimetrie gecid was computed by spherical fast fourier transform with modified Stokes＇ kernels. The remove-restore technique was used to eliminate the terrain effects by use of the RTM reduction and to determine the residual geoid by combining the GGM02S/EGM96 geopotential model, free-air gravity anomalies and high-resolutinn DEM data. Finally, the gravimetric model was fitted to the geoid heights obtained from GPS and tide observations （Ncps/Tiae） by least square coUocatian, to provide the final GPS-consistent local precise geoid model. The post-fit error （std. dev. ） of the final geoid to the NetS/Tide derived from GPS and tide observations was ± 2.2 cm for the construction area. We solved the height inconsistency problem by calculating the orthometric height of the benchmarks and the cnntrol points using the final geoid model. Also, the highly accurate orthometric height was estimated through the GPS/lev

关键词： precise local geoid consistent height system gravity observations GPS! Tide observations least squares fitting

Study on Extraction and Conversion Annatto （Bixa orellana L.） Color into Norbixin to Prepare Food Grade Water-Soluble Norbixin Powder

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Journal of Life Sciences 2017年第2期11卷 97-104页

作者： tran thi ha Dao Phan Thoai Le thi Thu Thuy Phan The Dong The Department of Food- Environment & Nursing Dong Nai Technology University Dong Nai 810000 Viet Nam The Faculty of Science & Engineering Hoa Sen University Ho Chi Minh 700000 Viet Nam

Response surface methodology was used in this research to optimize the technical parameters of the extraction and conversion color compound in armatto seeds into norbixin. Parameters affected the extraction efficiency and norbixin recovery yield were solvent concentration, rate of solvent/seed, incubation time, and incubation temperature. The optimization results including： concentration of ethanol is 51.82°; concentration of NaOH is 0.52 M; ratio of solvent/seed is 7.1/1; incubation time is 33.12 minutes, incubation temperature is 58.6℃, and the rate of 36% HCl/color solution is 0.5/5 （v/v）.

关键词： Achiote Bixa orellana L. bixin norbixin extraction conversion food color.

Fuzzy Feedback Control for Electro-Hydraulic Actuators

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Intelligent Automation & Soft Computing 2023年第5期36卷 2441-2456页

作者： Tan Nguyen Van Huy Q.tran Vinh Xuan ha Cheolkeun ha Phu Huynh Minh School of Engineering-Technology Thu Dau Mot UniversityThu Dau Mot City590000Vietnam Faculty of Engineering-Technology Nguyen Tat Thanh UniversityHo Chi Minh City754000Vietnam Hue Industrial College Hue City530000Vietnam Robotics and Mechatronics Lab University of UlsanUlsan City44610Korea

Electro-hydraulic actuators(Eha)have recently played a signiﬁcant role in modern industrial applications,especially in systems requiring extremely high *** can be explained by Eha’s ability to precisely control the position and force through advanced sensors and innovative control *** of the promising approaches to improve control accuracy for Eha systems is applying classical to modern control algorithms,in which the proportional–inte-gral–derivative(PID)algorithm,fuzzy logic controller,and a hybrid of these methods are popular *** this paper,we developed a novel version of the fuzzy control algorithm and linear feedback control method,namely fuzzy lin-ear feedback control,to improve the control *** achieve the highest performance,weﬁrst designed a mathematical Eha model based on the Matlab/Simulink software packages thanks to the selected parameters,which are similar to a real Eha ***,we respectively applied PID,fuzzy PID(FPID),and fuzzy linear feedback control(FLFC)before comparing them to have a full view of the outstanding advantages of the proposed *** simulation results showed that the proposed FLFC algorithm is approximately 99%and 77%super-ior in performance to the PID and feedback control algorithms,respectively.

关键词： Electro-hydraulic actuator fuzzy PID feedback control