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Frontiers of Structural and Civil Engineering 2024年第3期18卷 461-489页

作者： quoc-Hoa PHAM Van Ke tran Phu-Cuong Nguyen Faculty of Engineering and Technology Nguyen Tat Thanh UniversityHo Chi Minh City 700000Vietnam Faculty of Mechanical Engineering Le Quy Don Technical UniversityHanoi 100000Vietnam Advanced Structural Engineering Laboratory Department of Structural EngineeringFaculty of Civil EngineeringHo Chi Minh City Open UniversityHo Chi Minh City 700000Vietnam

In this work,a novel refined higher-order shear deformation plate theory is integrated with nonlocal elasticity theory for analyzing the free vibration,bending,and transient behaviors of fluid-infiltrated porous metal foam piezoelectric nanoplates resting on Pasternak elastic foundation with flexoelectric *** analysis(IGA)and the Navier solution are applied to the *** innovation in the present study is that the influence of the in-plane variation of the nonlocal parameter on the free and forced vibration of the piezoelectric nanoplates is investigated for the first *** nonlocal parameter and material characteristics are assumed to be material-dependent and vary gradually over the thickness of *** on Hamilton’s principle,equations of motion are built,then the IGA approach combined with the Navier solution is used to analyze the static and dynamic response of the ***,we investigate the effects of the porosity coefficients,flexoelectric parameters,elastic stiffness,thickness,and variation of the nonlocal parameters on the mechanical behaviors of the rectangular and elliptical piezoelectric nanoplates.

关键词： isogeometric analysis fluid-infiltrated porous piezoelectric nanoplates static and transient analysis flexoelectric effect variable nonlocal parameters

Exact solution for thermal vibration of multi-directional functionally graded porous plates submerged in fluid medium

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Defence Technology（防务技术） 2024年第5期35卷 77-99页

作者： quoc-Hoa Pham Van Ke tran Phu-Cuong Nguyen Faculty of Engineering and Technology Nguyen Tat Thanh UniversityHo Chi Minh CityViet Nam Faculty of Mechanical Engineering Le Quy Don Technical UniversityHanoiViet Nam Advanced Structural Engineering Laboratory Department of Structural EngineeringFaculty of Civil EngineeringHo Chi Minh City Open UniversityHo Chi Minh CityViet Nam

An analytical method for analyzing the thermal vibration of multi-directional functionally graded porous rectangular plates in fluid media with novel porosity patterns is developed in this *** properties of MFG porous plates change according to the length,width,and thickness directions for various materials and the porosity distribution which can be widely applied in many fields of engineering and defence ***,new porous rules that depend on spatial coordinates and grading indexes are proposed in the present *** Hamilton's principle and the refined higher-order shear deformation plate theory,the governing equation of motion of an MFG porous rectangular plate in a fluid medium(the fluid-plate system)is *** fluid velocity potential is derived from the boundary conditions of the fluid-plate system and is used to compute the extra *** GalerkinVlasov solution is used to solve and give natural frequencies of MFG porous plates with various boundary conditions in a fluid *** validity and reliability of the suggested method are confirmed by comparing numerical results of the present work with those from available works in the *** effects of different parameters on the thermal vibration response of MFG porous rectangular plates are studied in *** findings demonstrate that the behavior of the structure within a liquid medium differs significantly from that within a vacuum ***,they offer appropriate operational approaches for the structure when employed in various mediums.

关键词： Plate-fluid contact Galerkin Vlasov's method Multi-directional functionally graded plate Novel porosity Thermal vibration Refined higher-order shear deformation theory

Control Rod Calibration and Worth Calculation for Optimized Power Reactor 1000 (OPR-1000) Using Core Simulator OPR1000

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World Journal of Nuclear Science and Technology 2017年第1期7卷 15-23页

作者： Nguyen An Son Nguyen Duc Hoa tran Trung Nguyen tran quoc tuan Osvaldo Camueje Raul Dalat University Da Lat Vietnam Agostinho Neto University Luanda Angola

Control rod is used to change the power in nuclear reactor.?Certainly, the core at any moment can be made subcritical condition and shut downs when occurring?to emergency instance in the core. The rod is grouped based?on their function and located at different places in the core where their feature is maximized.?Two methods of control rod calibration are the asymptotic period method and the rod-drop method, which were applied in this experiment. In the first method, the reactor is made supcritical by inserting the control rod to be calibrated a certain level. The rod drop method is to determine the subcritical;at the critical state, the rod to be calibrated is dropped into the core, and the resulting decay of neutron flux is observed and related to the reactivity. In this paper, the regulating rod will be calibrated according to the reactivity in OPR-1000 that corresponds to a certain control rod insert or withdraw, and the reactivity in power reactor depends?on the integral and differential control rod group too. The core simulator OPR1000 is used to test those methods.

关键词： Control Rod The Asymptotic Period Method The Rod-Drop Method Core Simulator OPR1000

An isogeometric approach for nonlocal bending and free oscillation of magneto-electro-elastic functionally graded nanobeam with elastic constraints

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Frontiers of Structural and Civil Engineering 2024年第9期18卷 1401-1423页

作者： Thu Huong NGUYEN THI Van Ke tran quoc Hoa PHAM School of Mechanical and Automotive Engineering Hanoi University of IndustryHanoi 100000Vietnam Faculty of Mechanical Engineering Le Quy Don Technical UniversityHanoi 100000Vietnam Faculty of Engineering and Technology Nguyen Tat Thanh UniversityHo Chi Minh City 700000Vietnam

This work uses isogeometric analysis(IGA),which is based on nonlocal hypothesis and higher-order shear beam hypothesis,to investigate the static bending and free oscillation of a magneto-electro-elastic functionally graded(MEE-FG)nanobeam subject to elastic boundary constraints(BCs).The magneto-electric boundary condition and the Maxwell equation are used to calculate the variation of electric and magnetic potentials along the thickness direction of the *** study is innovative since it does not use the conventional boundary ***,an elastic system of straight and torsion springs with controllable stiffness is used to support nanobeams’beginning and end positions,creating customizable *** governing equations of motion of nanobeams are established by applying Hamilton’s principle and IGA is used to determine deflections and natural frequency *** studies were performed to evaluate the convergence and accuracy of the proposed *** from this,the impact of the input parameters on the static bending and free oscillation of the MEE-FG nanobeam is examined in *** findings could be valuable for analyzing and designing innovative structures constructed of functionally graded MEE materials.

关键词： elastic boundary conditions isogeometric analysis nanobeam via nonlocal theory grading of magneto-electro-elastic functions

Nonlocal isogeometric analysis for bidirectional functionally graded porous curved microbeams with arbitrary boundary conditions

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Acta Mechanica Sinica 2024年第8期40卷 194-218页

作者： Thu-Huong Nguyen Thi Van Ke tran Van-Minh Phung Van Hai Trinh quoc Hoa Pham Faculty of Mechanical Engineering Hanoi University of IndustryHanoi100000Vietnam Faculty of Mechanical Engineering Le Quy Don Technical UniversityHanoi100000Vietnam Institute of Vehicle and Energy Engineering Le Quy Don Technical UniversityHanoi100000Vietnam Faculty of Engineering and Technology Nguyen Tat Thanh UniversityHo Chi Minh City700000Vietnam

This research aims to analyze the static bending and free vibration behaviors of bidirectional functionally graded porous(BFGP)curved microbeams with elastic boundary conditions resting on a Pasternak’s elastic foundation in a hygro-thermal *** analysis based on non-uniform rational B-splines,first-order shear deformation theory,nonlocal elasticity theory combined with the modified strain gradient theories,modified Timoshenko beam theory are formulated to depict bending and shear deformations of BFGP curved ***,because using the modified Timoshenko beam theory,this study removes the requirement for a shear correction factor and describes shear stress by zero at the upper and lower cross-sectional sites of the BFGP curved *** from traditional boundary conditions,where the beginning and end positions of a curved beam are connected by an elastic system of straight and torsion *** allows for greater flexibility in controlling the stiffness of the springs to obtain arbitrary *** assess the accuracy and convergence of the proposed approach,validation numerical examples were conducted in the various examples.

关键词： Bidirectional functionally graded porous material Elastic boundary condition Isogeometric analysis Curved microbeams Nonlocal elasticity theory Modified strain gradient theory

Prevalence and outcomes of neonates with severe COVID-19:An observational study at Children’s Hospital 1 in Ho Chi Minh City,Vietnam

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Asian Pacific Journal of Tropical Medicine 2024年第9期17卷 392-399,I0001页

作者： Phung Nguyen The Nguyen tran Thanh Thuc Nguyen Thanh Hung Ngo Ngoc Quang Minh Dang quoc Duy tran Minh Nhut Nguyen Hoang Dung tran Nguyen Ai Nuong Dinh Nguyen Cam Tu Department of Pediatrics University of Medicine and Pharmacy at Ho Chi Minh cityHo Chi Minh CityVietnam Children’s Hospital 1 Ho Chi Minh CityVietnam Pediatric Department School of MedicineVietnam National University Ho Chi Minh CityVietnam

Objective:To evaluate the impact of the severe COVID-19 pandemic on neonates and develop strategies to improve their ***:We conducted an observational cross-sectional study at Children's Hospital 1(CH1)from July 25,2021,to May 31,*** neonates who had fever or respiratory symptoms or were born from mothers with COVID-19 and had a positive RT-PCR SARS-CoV-2 result would be *** classified neonates with COVID-19 into 2 groups:mild/moderate and severe for *** between groups were analyzed using Fisher's exact test/Chi-square test for categorical variables and Student's t-test/Wilcoxon Rank Sum test for continuous ***:This study included 88 newborns who had positive RT-PCR SARS-CoV-2 *** severity COVID-19 rate among neonatal cases was found to be 13.6%(12/88),with a corresponding mortality rate of 1.1%(1/88).All severe cases showed lung abnormalities as evident on chest X-ray *** addition to respiratory symptoms,a higher incidence of gastrointestinal manifestations,such as vomiting and diarrhea,was observed in the severe group,indicating a compelling *** administration of anticoagulant and anti-inflammatory drugs in the study group resulted in a satisfactory outcome with no significant ***:The COVID-19 pandemic has had a substantial impact on the well-being of *** management of COVID-19 in this population presents significant challenges.

关键词： COVID-19 Neonate Anti-inflammatory Anticoagulant

EP Aquarii:A New Picture of the Circumstellar Envelope

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Research in Astronomy and Astrophysics 2024年第3期24卷 83-105页

作者： Pham T.Nhung Do T.Hoai Pierre Darriulat Pham tuan-Anh Pham N.Diep Nguyen B.Ngoc tran T.Thai Department of Astrophysics Vietnam National Space CenterVietnam Academy of Science and Technology18Hoang Quoc VietNghia DoCau GiayHa Noivietnam

New analyses of earlier ALMA observations of oxygen-rich AGB star EP Aquarii are presented,which complete a previously published analysis and offer a different interpretation of the morpho-kinematics of the circumstellar *** birth of the equatorial density enhancement(EDE)is shown to occur very close to the star where evidence for rotation has been *** to the star and where outflows have been observed:their interaction with the gas of the nascent EDE is seen to play an important role in the development of the wind and the evolution of its radial velocity from 8 to 10 km s^(-1) on the polar symmetry axis to~2 km s^(-1) at the *** implies complex morpho-kinematics:making reliable interpretations with reasonable confidence is *** particular,it questions an earlier interpretation implying the presence of a white dwarf companion orbiting the star at an angular distance of -0″4 from its *** proposes instead an interpretation in terms of a standard mass ejection associated with a shock wave leaving a void of emission in its *** Doppler velocity wings are seen to consist of two components,the upper velocity end of the global wind,reaching above±12 km s^(-1),and an effective line broadening,confined within 200 mas from the center of the star,reaching above±20 km s^(-1) and interpreted as caused by the pattern of shock waves resulting from the interaction between stellar pulsation and convective cell partition.

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

Effectiveness and safety of electroacupuncture analgesia in controlling intraoperative pain and hemodynamics during total thyroidectomy:A randomized controlled trial

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Journal of Traditional Chinese Medical Sciences 2024年第2期11卷 165-171页

作者： Dong Phuong tran quoc Dung Nguyen Ninh Khac Nguyen Van Hong Pham Senior Specialist Clinic National Hospital of AcupunctureHanoi10000Vietnam Vietnam National Association of Acupuncture Hanoi10000Vietnam Department of Training and Science National Hospital of AcupunctureHanoi10000Vietnam

Objective:To evaluate the effectiveness and safety of electroacupuncture in conjunction with additional medications in providing analgesia and stabilizing hemodynamic parameters during total ***:This randomized controlled trial included 100 patients who underwent a total thyroidectomy between October 2022 and October 2023 at the Vietnam National Hospital of *** patients were randomized into two *** electroacupuncture analgesia(EA)group received EA stimulation at five acupuncture points:Hegu(LI 4),Neiguan(PC 6),Shuitu(ST 10),Quepen(ST 12),and Yifeng(SJ 17),while the control group received a bilateral superficial cervical plexus *** outcomes included the level of analgesia and perioperative vital signs in both ***,pain thresholds and serum b-endorphin levels were measured before and after electroacupuncture in the EA ***:Complete analgesia(Level A)was attained in 86%and 76%of the patients in the EA and control groups,respectively,with no significant difference between the two groups(P¼1.00).In the EA group,the mean pain threshold after receiving EA doubled(648.7(77.4)g/s vs.305.3(45.3)g/s,P<.001),and the mean serum b-endorphin level increased by approximately 13.5 pg/mL(P<.001).All patients remained hemodynamically stable throughout the ***:EA,in conjunction with additional medications that stimulate five acupuncture points,LI 4,PC 6,ST 10,ST 12,and SJ 17,was well tolerated and effectively maintained a suitable level of analgesia and hemodynamic stability during total thyroidectomy.

关键词： Electroacupuncture Acupuncture analgesia Graves'disease Thyroidectomy Thyroid surgery b-Endorphin

A Study on Optimizing the Double-Spine Type Flow Path Design for the Overhead transportation System Using Tabu Search Algorithm

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Intelligent Automation & Soft Computing 2024年第2期39卷 255-279页

作者： Nguyen Huu Loc Khuu Thuy Duy Truong quoc Dien Le tran Thanh Cong Vu Hoa Binh tran Tuong Quan Vo Department of Mechatronics Faculty of Mechanical EngineeringHo Chi Minh City University of Technology(HCMUT)Ho Chi Minh CityVietnam Bach Khoa Research Center for Manufacturing Engineering Ho Chi Minh City University of Technology(HCMUT)Ho Chi Minh CityVietnam VietnamNational University Ho ChiMinh City Ho ChiMinh CityVietnam

Optimizing Flow Path Design(FPD)is a popular research area in transportation system design,but its application to Overhead transportation Systems(OTSs)has been *** study focuses on optimizing a double-spine flow path design for OTSs with 10 stations by minimizing the total travel distance for both loaded and empty *** employ transportation methods,specifically the North-West Corner and Stepping-Stone methods,to determine empty vehicle travel ***,the Tabu Search(TS)algorithm is applied to branch the 10 stations into two main layout *** results obtained from our proposed method demonstrate a reduction in the objective function value compared to the initial feasible ***,we explore howchanges in the parameters of the TS algorithm affect the optimal *** validate the feasibility of our approach by comparing it with relevant literature and conducting additional tests on layouts with 20 and 30 stations.

关键词： Overhead transportation systems tabu search double-spine layout transportationmethod empty travel flow path design

Products of Commutator Ideals of Some Lie-admissible Algebras

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Acta Mathematica Sinica,English Series 2024年第8期40卷 1875-1892页

作者： Ivan KAYGORODOV Farukh MASHUROV tran Giang NAM Ze Rui ZHANG CMA-UBI Universidade da Beira InteriorCovilhaPortugal Shenzhen International Center for Mathematics(SICM) Southern University of Science and TechnologyShenzhen 518055P.R.China Institute of Mathematics VAST18 Hoang Quoc VietCau GiayHanoiVietnam School of Mathematical Sciences South China Normal UniversityGuangzhou 510631P.R.China

In this article,we mainly study the products of commutator ideals of Lie-admissible algebras such as Novikov algebras,bicommutative algebras,and assosymmetric *** precisely,we first study the properties of the lower central chains for Novikov algebras and bicommutative *** we show that for every Lie nilpotent Novikov algebra or Lie nilpotent bicommutative algebra A,the ideal of A generated by the set{ab−ba|a,b∈A}is ***,we study properties of the lower central chains for assosymmetric algebras,study the products of commutator ideals of assosymmetric algebras and show that the products of commutator ideals have a similar property as that for associative algebras.

关键词： Novikov algebra bicommutative algebra assosymmetric algebra Lie nilpotent algebra