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A fully automated framework for helicopter rotor blades design and analysis including aerodynamics,structure, and manufacturing

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Chinese Journal of Aeronautics 2016年第6期29卷 1602-1617页

作者： Ngoc Anh Vu Jae Woo lee Tuan Phuong Nam le Song thanh Thao Nguyen Division of Computational Mechatronics Institute for Computational Science Ton Duc Thang University Faculty of Electrical & Electronics Engineering Ton Duc Thang University Department of Aerospace Information Engineering Konkuk University Faculty of Mechanical Engineering Industrial University of Ho Chi Minh City Department of Aerospace Engineering Ho Chi Minh City University of Technology Vietnam National University-Ho Chi Minh City

This study describes an integrated framework in which basic aerospace engineering aspects(performance, aerodynamics, and structure) and practical aspects(configuration visualization and manufacturing) are coupled and considered in one fully automated design optimization of rotor blades. A number of codes are developed to robustly perform estimation of helicopter configuration from sizing, performance analysis, trim analysis, to rotor blades configuration representation. These codes are then integrated with a two-dimensional airfoil analysis tool to fully design rotor blades configuration including rotor planform and airfoil shape for optimal aerodynamics in both hover and forward flights. A modular structure design methodology is developed for realistic composite rotor blades with a sophisticated cross-sectional geometry. A D-spar cross-sectional structure is chosen as a baseline. The framework is able to analyze all realistic inner configurations including thicknesses of D-spar, skin, web, number and ply angles of layers of each composite part,and materials. A number of codes and commercial software(ANSYS, Gridgen, VABS, Pre VABS,etc.) are implemented to automate the structural analysis from aerodynamic data processing to sectional properties and stress analysis. An integrated model for manufacturing cost estimation ofcomposite rotor blades developed at the Aerodynamic Analysis and Design Laboratory(AADL),Aerospace Information Engineering Department, Konkuk University is integrated into the framework to provide a rapid and dynamic feedback to configuration design. The integration of three modules has constructed a framework where the size of a helicopter, aerodynamic performance analysis, structure analysis, and manufacturing cost estimation could be quickly investigated. All aspects of a rotor blade including planform, airfoil shape, and inner structure are considered in a multidisciplinary design optimization without an exception of critical configuration.

关键词： Design optimization Helicopter rotor blades Integrated framework Modular structure design methodology Perform estimation

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Structural and luminescent properties of (Eu,Tb) PO_4·H_2O nanorods/nanowires prepared by microwave technique

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Journal of Rare Earths 2011年第12期29卷 1170-1173页

作者： Nguyen thanh Huong Nguyen Duc Van Dinh Manh Tien Do Khanh Tung Nguyen thanh Binh Tran Kim Anh le Quoc Minh Institute of Materials Science Vietnam Academy of Science and Technology University of Engineering and Technology National University HanoiVietnam

Nanowires/nanorods of europium/terbium orthophosphate monohydrate with Eu^3＋ concentration of 6, 11, and 20 at.% were prepared by microwave synthesis method. The effects of Eu^3＋ doping concentration on structure, morphology and optical properties of nanomaterials were also investigated. The results showed that, for all studied Eu^3＋ doping concentrations, a single-crystalline phase of rhabdophane-type （Eu,Tb）PO4·H2O nanowires/nanorods was obtained by using microwave heating of an aqueous solution of terbium（Ⅲ） nitrate, europium（Ⅲ） nitrate and NH4H2PO4 with pH=2. The length and width of these nanowires/nanorods ranged from 150 to 300 nm and from 10 to 50 nm, respectively. The evidence of energy transfer from Tb^3＋ to Eu^3＋ due to the energy overlap between the donor Tb^3＋ and the acceptor Eu^3＋was observed obviously via a significant enhancement in the luminescent intensity of Eu^3＋. Keywords：

关键词： microwave technique nanowires/nanorods energy transfer fluorescence spectroscopy rare earths

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Novel enzymatically crosslinked chitosan hydrogels with free-radical-scavenging property and promoted cellular behaviors under hyperglycemia

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Progress in Natural Science:Materials International 2020年第5期30卷 661-668页

作者： Dieu Linh Tran Phuong le Thi Thai thanh Hoang Thi Ki Dong Park Department of Molecular Science and Technology Ajou University Biomaterials and Nanotechnology Research Group Faculty of Applied Sciences Ton Duc Thang University

The impairment of regenerative processes induced by high blood-glucose level(hyperglycemia) and excessive reactive oxygen species(ROS) contributes to the diabetic complication progression and development. In this study, an injectable, in situ crosslinkable chitosan hydrogel with ROS-scavenging capability was developed by conjugating gallic acid onto the chitosan backbone(CGA). We hypothesized that gallic acid serves as both antioxidant and crosslinking moieties to form hydrogel in situ by means of enzymatic crosslinking with horseradish peroxidase(HRP). The rapid gelation(from 30 s) was observed by vial tilting. The mechanical properties and microstructures of CGA hydrogels can be well controlled by varying the concentrations of H2O2. The ROSscavenging ability of these CGA hydrogels was demonstrated against DPPH radical, hydroxyl radical, and total reducing power. Notably, in an in vitro hyperglycemia environment, CGA hydrogels significantly improved the proliferation and migration of human dermal fibroblast cells, which are closely related to diabetic wound healing. These results suggest that CGA hydrogels have potential as advanced materials for the treatment of diabetes-related diseases via attenuating the excessive ROS production and improving cellular behaviors.

关键词： Chitosan Gallic acid Injectable hydrogel Hyperglycemia Free-radical-scavenging

Myo-inositol versus metformin effects on clinical features, endocrine and metabolic profiles in infertile women with polycystic ovary syndrome: A randomized controlled trial

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Asian pacific Journal of Reproduction 2023年第6期12卷 256-265页

作者： Nguyen Sa Viet le Minh Tam le thanh Ngoc Cao Center for OBGYN Hue Central Hospital16 Le Loi StreetHueVietnam Center for Reproductive Endocrinology and Infertility Hue University of Medicine and PharmacyHue University06 Ngo Quyen StreetHueVietnam

Objective:To compare the effectiveness of inositol and metformin on the clinical characteristics,and endocrine and metabolic profiles of infertile polycystic ovarian syndrome(PCOS)women from ***:From June 2018 to August 2022,a randomized trial was undertaken at the Hue Center for Endocrinology and Reproduction on infertile women aged 18 to 40 years with polycystic ovarian *** clinical,endocrine,and metabolic features of these individuals were assessed before and after 3 months of treatment with 2 g of inositol or 1700 mg of metformin per *** pregnancy rates,adverse effects,and tolerance of inositol were ***:The study included 171 infertile PCOS women who were eligible to participate and took part in the baseline assessment,of whom 132 women participated in data analysis after 3 *** metformin treatment,42.1%of women with oligomenorrhea experienced regular *** significantly lowered body mass index(BMI),waist circumference and testosterone levels,but had no effect on other clinical characteristics,endocrine profiles,or metabolic profiles.29.2%Of women reported experiencing side effects.21%Of them attained pregnancy,which resulted in 17.1%of live *** the inositol group,the rate of regular cycle increased by 18.2%and the total testosterone concentration significantly *** overweight/obese women with PCOS,inositol significantly decreased weight,BMI,waist and hip circumferences(Plerated inositol and continued treatment.18.9%Of them became pregnant,leading to 17%of live ***:Metformin and inositol can improve weight and waist circumference in overweight/obese infertile women with *** is associated with a higher rate of regular menstruation,whereas inositol is associated with a lower rate of adverse *** spontaneous conception,clinical pregnancy,and live birth rates between two groups are comparable.

关键词： Polycystic ovarian syndrome Inositol Metformin Endocrine Metabolic Menstrual cycle Pregnancy

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生物质气化技术介绍

江苏锅炉 2024年第3期 41-48页

作者： thanh Phong Mai Dinh Quan Nguyen 汪小雯(译) Ho Chi Minh City University of Technology MAI THANH PHONG 无锡华光环保能源集团股份有限公司江苏无锡214024

气化是通过间接燃烧的方式将固体和液体生物质转化为可燃气体的过程。作为一种替代传统燃烧的方法,气化技术能够在很大程度上降低粉尘和有害气体的排放。本文旨在从环境影响和技术增益两个维度,对这两种生物质热转化方式展开比较分析,... 详细信息

气化是通过间接燃烧的方式将固体和液体生物质转化为可燃气体的过程。作为一种替代传统燃烧的方法,气化技术能够在很大程度上降低粉尘和有害气体的排放。本文旨在从环境影响和技术增益两个维度,对这两种生物质热转化方式展开比较分析,旨在为读者提供一个基础的选择参考。气化过程可细分为气化剂的选择、非催化工艺、催化工艺以及等离子体辅助工艺等几个方面。本文还将介绍常见的气化设备类型一一气化器,并结合其工作原理,对气化技术的利弊进行简要探讨。

关键词：气化气化炉生物质间接燃烧直接燃烧合成气等离子体上升降气流交又气流搭桥焦油木炭氢气蒸汽二氧化碳烟气

Dealing with the Class Imbalance Problem in the Detection of Fake Job Descriptions

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Computers, Materials & Continua 2021年第7期68卷 521-535页

作者： Minh thanh Vo Anh H.Vo Trang Nguyen Rohit Sharma Tuong le Faculty of Information Technology Ho Chi Minh City University of Technology(HUTECH)Ho Chi Minh CityVietnam Faculty of Information Technology Ton Duc Thang UniversityHo Chi Minh CityVietnam Faculty of Information Technology Ho Chi Minh City Open UniversityHo Chi Minh CityVietnam Department of Electronics&Communication Engineering SRM Institute of Science and TechnologyNCR CampusGhaziabadIndia Informetrics Research Group Ton Duc Thang UniversityHo Chi Minh CityVietnam

In recent years,the detection of fake job descriptions has become increasingly necessary because social networking has changed the way people access burgeoning information in the internet *** fraud in job descriptions can help jobseekers to avoid many of the risks of job ***,the problem of detecting fake job descriptions comes up against the problem of class imbalance when the number of genuine jobs exceeds the number of fake *** causes a reduction in the predictability and performance of traditional machine learning *** therefore present an efficient framework that uses an oversampling technique called FJD-OT(Fake Job Description Detection Using Oversampling Techniques)to improve the predictability of detecting fake job *** the proposed framework,we apply several techniques including the removal of stop words and the use of a tokenizer to preprocess the text data in the first *** then use a bag of words in combination with the term frequency-inverse document frequency(TF-IDF)approach to extract the features from the text data to create the feature dataset in the second ***,our framework applies k-fold cross-validation,a commonly used technique to test the effectiveness of machine learning models,that splits the experimental dataset[the Employment Scam Aegean(ESA)dataset in our study]into training and test sets for *** training set is passed through the third module,an oversampling module in which the SVMSMOTE method is used to balance data before training the classifiers in the last *** experimental results indicate that the proposed approach significantly improves the predictability of fake job description detection on the ESA dataset based on several popular performance metrics.

关键词： Fake job description detection class imbalance problem oversampling techniques

Effects of Serum Concentration, Synchronization Time and Confluence on the Cell-Cycle Synchronization Efficiency of Goat Fibroblasts

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Open Journal of Animal Sciences 2024年第3期14卷 194-203页

作者： Van Khanh Nguyen Huong Thu Thi Vu Au Thi Hoang Yen Kim Thi Pham Giang Thi thanh Nhan Hung Phu Lai Lan Doan Pham Key Laboratory of Animal Cell Biotechnology National Institute of Animal Science Hanoi Vietnam

This study aims to evaluate the effect of serum concentration, synchronization time, and confluence degree on the synchronisation efficiency of goat fibroblast cycle. The results indicated that there was no difference in the percentage of nucleated fibroblasts in the G0/G1 stage between serum concentrations of 0.3% and 0.4% (83.89% and 82.69%, respectively, P > 0.05) as well as between serum concentrations of 0.2% and 0.5% (76.95% and 75.46%, respectively, P > 0.05). The percentage of nucleated fibroblasts in the G0/G1 stage was highest at the concentration of 0.3% and lowest in the control group (83.89% vs. 62.67%, P 0.05). The beneficial effect of high confluence was confirmed by the large percentage of nucleated fibroblasts at the G0/G1 stage. The 60% confluency was significantly lower than the 80% and 100% confluency (73.44%, 86.63%, and 87.17%, respectively, P le synchronization is the most effective at the serum concentration of 0.3%, 72 hours of synchronization and 100% confluency.

关键词： Goat Fibroblast Cycle Synchronisation Serum Concentration Synchronization Time Confluence

Study of vertically ascending flight of a hawkmoth model

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Acta Mechanica Sinica 2020年第5期36卷 1031-1045,I0002页

作者： Anh Tuan Nguyen Vu Dan thanh le The Hung Tran V.N.Due Van Binh Phung Faculty of Aerospace Engineering Le Quy Don Technical UniversityHanoiVietnam Institute of Theoretical and Applied Research.Duy Tan University HanoiVietnam Division of Construction Computation Institute for Computational ScienceTon Due Thang UniversityHo Chi Minh CityVietnam Faculty of Civil Engineering Ton Due Thang UniversityHo Chi Minh CityVietnam

This paper provides insight into the wing kinematics,the power requirement and the dynamic stability characteristics of a hawkmoth model in vertically ascending *** wing kinematics of the hawkmoth model is obtained based on the minimum required power *** optimization process is conducted using genetic and simplex algorithms that are coupled with an artificial neural network to rapidly predict the aerodynamic force and required *** training data for the neural network are generated from an unsteady vortex-lattice *** to hover,the results in this study show the larger flapping frequency and the smaller rotation amplitude of the hawkmoth wing kinematics in ascending ***,more power is required when the ascending speed *** conducting a dynamic modal analysis based on a cycle-average approach,the certain effect of the ascending speed on the modal structures of the hawkmoth model was observed.

关键词： Hawkmoth Ascending flapping flight-Genetic algorithm Artificial neural network Flight dynamic stability

The Roles of Female Involvement and Risk Aversion in Open Access Publishing Patterns in Vietnamese Social Sciences and Humanities

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Journal of Data and Information Science 2022年第1期7卷 76-96页

作者： Minh-Hoang Nguyen Huyen thanh thanh Nguyen Manh-Toan Ho Tam-Tri le Quan-Hoang Vuong Centre for Interdisciplinary Social Research Phenikaa UniversityYen Nghia WardHa Dong DistrictHanoi 100803Vietnam

Purpose:The open-access(OA)publishing model can help improve researchers’outreach,thanks to its accessibility and visibility to the ***,the presentation of female researchers can benefit from the O A publishing *** that,little is known about how gender affects OA ***,the current study explores the effects of female involvement and risk aversion on OA publishing patterns among Vietname se social sciences and ***/methodology/approach:The study employed Bayesian Mindsponge Framework(BMF)on a dataset of 3,122 Vietnamese social sciences and humanities(SS&H)publications during *** Mindsponge mechanism was specifically used to construct theoretical models,while Bayesian inference was utilized for fitting ***:The result showed a positive association between female participation and OA publishing ***,the positive effect of female involvement on OA publishing probability was negated by the high ratio of female researchers in a *** status was negatively associated with the JIF of the journal in which the publication was published,but the relationship was moderated by the involvement of a female researcher(s).The findings suggested that Vietnamese female researchers might be more likely to publish under the OA model in journals with high JIF for avoiding the risk of public *** limitations:The study could only provide evidence on the association between female involvement and OA publishing ***,whether to publish under OA terms is often determined by the first or corresponding authors,but not necessarily *** implications:Systematically coordinated actions are suggested to better support women and promote the OA movement in ***/value:The findings show the OA publishing patterns of female researchers in Vietnamese SS&H.

关键词： Open science Gender inequality Risk-aversion Vietnam Bayesian analysis

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