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Transient responses of double-curved sandwich two-layer shells resting on Kerr's foundations with laminated three-phase polymer/GNP/fiber surface and auxetic honeycomb core subjected to the blast load

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Defence Technology（防务技术） 2024年第5期35卷 222-247页

作者： nguyen Thi Hai Van Thi Hong nguyen Researcher&Lecturer Faculty of Industrial EducationThe University of Danang-University of Technology and Education48 Cao ThangDanang550000Viet Nam Researcher&Lecturer Faculty of Mechanical EngineeringThuyloi University175 Tay SonDong DaHanoi100000Viet Nam

This work uses refined first-order shear theory to analyze the free vibration and transient responses of double-curved sandwich two-layer shells made of auxetic honeycomb core and laminated three-phase polymer/GNP/fiber surface subjected to the blast *** of the two layers that make up the double-curved shell structure is made up of an auxetic honeycomb core and two laminated sheets of three-phase polymer/GNP/*** exterior is supported by a Kerr elastic foundation with three *** key innovation of the proposed theory is that the transverse shear stresses are zero at two free surfaces of each *** contrast to previous first-order shear deformation theories,no shear correction factor is ***'s exact solution was used to treat the double-curved shell problem with a single title boundary,while the finite element technique and an eight-node quadrilateral were used to address the other boundary *** ensure the accuracy of these results,a thorough comparison technique is employed in conjunction with credible *** problem model's edge cases allow for this kind of *** study's findings may be used in the post-construction evaluation of military and civil works structures for their ability to sustain explosive *** addition,this is also an important basis for the calculation and design of shell structures made of smart materials when subjected to shock waves or explosive loads.

关键词： Blast load Two-layer shell Polymer/GNP/Fiber surface Auxetic honeycomb Shear connectors

Chebyshev polynomial-based Ritz method for thermal buckling and free vibration behaviors of metal foam beams

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Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 891-910页

作者： N.D.nguyen T.N.nguyen Faculty of Civil Engineering Ho Chi Minh City University of Technology and EducationHo Chi Minh City 71309Viet Nam Faculty of Engineering and Technology Kien Giang UniversityChau Thanh 92000Viet Nam

This study presents the Chebyshev polynomials-based Ritz method to examine the thermal buckling and free vibration characteristics of metal foam *** analyses include three models for porosity distribution and two scenarios for thermal *** material properties are assessed under two conditions,i.e.,temperature dependence and temperature *** theoretical framework for the beams is based on the higher-order shear deformation theory,which incorporates shear deformations with higher-order *** governing equations are established from the Lagrange equations,and the beam displacement fields are approximated by the Chebyshev *** simulations are performed to evaluate the effects of thermal load,slenderness,boundary condition(BC),and porosity distribution on the buckling and vibration behaviors of metal foam *** findings highlight the significant influence of temperature-dependent(TD)material properties on metal foam beams'buckling and vibration responses.

关键词： Ritz method Chebyshev function buckling vibration metal foam beam higher-order beam theory(HOBT)

Transient response of doubly-curved bio-inspired composite shells resting on viscoelastic foundation subject to blast load using improved first-order shear theory and isogeometric approach

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Defence Technology（防务技术） 2024年第8期38卷 171-193页

作者： Thuy Tran Thi Thu Tu nguyen Anh Hue nguyen Thi Hong nguyen Thi School of Mechanical and Automotive Engineering Hanoi University of IndustryHanoiViet Nam Faculty of Technical Fundamental University of Transport TechnologyHanoiViet Nam Faculty of Mechanical Engineering Thuyloi University175 Tay SonDong DaHanoiViet Nam

Investigating natural-inspired applications is a perennially appealing subject for scientists. The current increase in the speed of natural-origin structure growth may be linked to their superior mechanical properties and environmental resilience. Biological composite structures with helicoidal schemes and designs have remarkable capacities to absorb impact energy and withstand damage. However, there is a dearth of extensive study on the influence of fiber redirection and reorientation inside the matrix of a helicoid structure on its mechanical performance and reactivity. The present study aimed to explore the static and transient responses of a bio-inspired helicoid laminated composite(B-iHLC) shell under the influence of an explosive load using an isomorphic method. The structural integrity of the shell is maintained by a viscoelastic basis known as the Pasternak foundation, which encompasses two coefficients of stiffness and one coefficient of damping. The equilibrium equations governing shell dynamics are obtained by using Hamilton's principle and including the modified first-order shear theory,therefore obviating the need to employ a shear correction factor. The paper's model and approach are validated by doing numerical comparisons with respected publications. The findings of this study may be used in the construction of military and civilian infrastructure in situations when the structure is subjected to severe stresses that might potentially result in catastrophic collapse. The findings of this paper serve as the foundation for several other issues, including geometric optimization and the dynamic response of similar mechanical structures.

关键词： Blast load Modified first-order shear theory Biological composite structures

Push forward LC-MS-based therapeutic drug monitoring and pharmacometabolomics for anti-tuberculosis precision dosing and comprehensive clinical management

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Journal of Pharmaceutical Analysis 2024年第1期14卷 16-38页

作者： nguyen Quang Thu nguyen Tran Nam Tien nguyen Thi Hai Yen Thuc-Huy Duong nguyen Phuoc Long Huy Truong nguyen Department of Pharmacology and PharmacoGenomics Research Center Inje University College of MedicineBusan47392Republic of Korea Department of Chemistry University of EducationHo Chi Minh City700000Viet Nam Faculty of Pharmacy Ton Duc Thang UniversityHo Chi Minh City700000Viet Nam

The spread of tuberculosis(TB),especially multidrug-resistant TB and extensively drug-resistant TB,has strongly motivated the research and development of new anti-TB *** strategies to facilitate drug combinations,including pharmacokinetics-guided dose optimization and toxicology studies of first-and second-line anti-TB drugs have also been introduced and *** chromatography-mass spectrometry(LC-MS)has arguably become the gold standard in the analysis of both endo-and exo-genous *** technique has been applied successfully not only for therapeutic drug monitoring(TDM)but also for pharmacometabolomics *** improves the effectiveness of treatment,reduces adverse drug reactions,and the likelihood of drug resistance development in TB patients by determining dosage regimens that produce concentrations within the therapeutic target *** on TDM,the dose would be optimized individually to achieve favorable *** is essential in generating and validating hypotheses regarding the metabolism of anti-TB drugs,aiding in the discovery of potential biomarkers for TB diagnostics,treatment monitoring,and outcome *** article highlighted the current progresses in TDM of anti-TB drugs based on LC-MS bioassay in the last two ***,we discussed the advantages and disadvantages of this technique in practical *** pressing need for non-invasive sampling approaches and stability studies of anti-TB drugs was ***,we provided perspectives on the prospects of combining LC-MS-based TDM and pharmacometabolomics with other advanced strategies(pharmacometrics,drug and vaccine developments,machine learning/artificial intelligence,among others)to encapsulate in an all-inclusive approach to improve treatment outcomes of TB patients.

关键词： Tuberculosis Therapeutic drug monitoring LC-MS MIPD Pharmacometabolomics Precision medicine

Tungsten-based nanocatalysts with different structures for visible light responsive photocatalytic degradation of bisphenol A

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Journal of Environmental Sciences 2024年第5期139卷 569-588页

作者： Hai Bang Truong Thi Thu Loan Doan nguyen Tien Hoang nguyen Van Tam Minh Kim nguyen Le Gia Trung Jin Seog Gwag nguyen Tien Tran Optical Materials Research Group Science and Technology Advanced InstituteVan Lang UniversityHo Chi Minh CityViet Nam Faculty of Applied Technology School of TechnologyVan Lang UniversityHo Chi Minh CityViet Nam The University of Da Nang University of Science and Technology54 Nguyen Luong BangDa NangViet Nam The University of Da Nang University of Science and Education459 Ton Duc Thang St.Lien ChieuDa Nang 550000Viet Nam Institute of Veterinary Science and Technology 31ha zoneTrau QuyGia LamHa Noi 12400Viet Nam Department of Physics Yeungnam UniversityGyeongsanGyeongbuk 38541Republic of Korea Center for Advanced Chemistry Institute of Research and DevelopmentDuy Tan University03 Quang TrungDa Nang 550000Viet Nam Faculty of Natural Sciences Duy Tan University03 Quang TrungDa Nang 550000Viet Nam

Environmental pollution,such as water contamination,is a critical issue that must be absolutely ***,three different morphologies of tungsten-based photocatalysts(WO_(3)nanorods,WO_(3)/WS_(2)nanobricks,WO_(3)/WS_(2)nanorods)are made using a simple hydrothermal method by changing the solvents(H_(2)O,DMF,aqueous HCl solution).The as-prepared nanocatalysts have excellent thermal stability,large porosity,and high *** results show all materials have good photocatalytic activity in aqueous media,with WO_(3)/WS_(2)nanorods(NRs)having the best activity in the photodegradation of bisphenol A(BPA)under visible-light *** may originate from increased migration of charge carriers and effective prevention of electron–hole recombination in WO_(3)/WS_(2)NRs,whereby this photocatalyst is able to generate more reactive·OH and·O_(2)^(–)species,leading to greater photocatalytic *** 99.6% of BPA is photodegraded within 60 min when using 1.5 g/L WO_(3)/WS_(2)NRs and 5.0 mg/L BPA at pH ***,the optimal conditions(pH,catalyst dosage,initial BPA concentration)for WO_(3)/WS_(2)NRs are also elaborately *** rod-like heterostructures are expressed as potential catalysts with excellent photostability,efficient reusability,and highly active effectivity in different types of *** particular,the removal efficiency of BPA by WO_(3)/WS_(2)NRs reduces by only 1.5% after five recycling runs and even reaches 89.1%in contaminated lake *** study provides promising insights for the nearly complete removal of BPA from wastewater or different water resources,which is advantageous to various applications in environmental remediation.

关键词： Photodegradation Bisphenol A Tungsten-based nanocatalyst Structure Nanorod

Prognostic value of N-terminal pro B-type natriuretic peptide and troponin Ⅰ in children with dengue shock syndrome

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Asian Pacific Journal of Tropical Medicine 2024年第4期17卷 166-172页

作者： Truyen Phuoc Le Phung nguyen The nguyen University of Medicine and Pharmacy at Ho Chi Minh city Ho Chi Minh CityVietnam Children's Hospital 1 Ho Chi Minh CityVietnam

Objective:To investigate the contribution of N-terminal pro B-type natriuretic peptide(NT-pro BNP)and troponin Ⅰ to mortality in children with dengue shock ***:A longitudinal study was conducted on children with dengue shock syndrome in a hospital in southern *** clinical histories,physical examinations,and laboratory parameters,including NT-pro BNP and troponin Ⅰ,were recorded.A comparison between survival and non-survival was carried out to identify factors influencing ***:A total of 107 patients with a median age of 9 years were included in the *** them,63.6%(68/107)presented with compensated shock,36.4%(39/107)had hypotensive shock,23.4%(25/107)required mechanical ventilation,and 12.1%(13/107)*** NT-pro BNP levels were 3.9 pmol/L(IQR:1.9,10.3)and 15.2 pmol/L(5.8,46.3),while the median high sensitivity troponin Ⅰ levels were 20 pg/L(6,95)and 62 pg/L(12,325)at the first and second measurements,*** mortality group exhibited higher rates of hypotensive shock,prolonged shock,lactate levels,liver damage,NT-pro BNP,and troponin Ⅰ *** shock(OR 12.96,95%CI 2.70-62.30,P=0.004),prolonged shock(OR 39.40,95%CI 6.68-232.70,P1000 IU/L(OR 9.50,95%CI 2.63-34.34,P=0.041),and NT-pro BNP>7 pmol/L(OR 44.40,95%CI 5.44-362.20,P=0.001)were identified as predictive factors for mortality in dengue shock ***:The NT-pro BNP level could serve as a potential biomarker for predicting mortality in children with dengue shock syndrome.

关键词： Dengue shock syndrome Cardiac enzyme NT-pro BNP TroponinⅠ

Study of relationship between motion of mechanisms in gas operated weapon and its shock absorber

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Defence Technology（防务技术） 2024年第3期33卷 42-54页

作者： Jiri Balla Roman Vitek Dung nguyen Van Zbynek Krist Hung nguyen Van Department of Weapons and Ammunition University of Defence BrnoCzech Republic Department of Weapons Le Quy Don Technical UniversityHanoiViet Nam Department of Design and Special Engineering Alexander Dubcek University of TrencinSlovakia

The article deals with the motion of the breech block carrier and the weapon casing of an automatic weapon mounted on a flexible carriage and the base of the *** works,which did not consider the dynamic properties of the base of the weapon,did not allow to reconcile the calculated and experimental results of the weapon casing displacement when shooting from firing *** the analysis of the motion of individual parts,the methods of mathematical modelling and firing experiments using a high-speed camera were *** show the best accord with experiment when modelling the system with 4 degrees of *** oscillation of the system regarding the movement of the breech block carrier and the weapon casing was investigated under changed conditions of rate of fire,the use of a muzzle brake and different types of shock *** velocities and displacements of the weapon casing and the breech block carrier at different values of the impulse of the gases to the breech block carrier were determined.

关键词： Shock absorber Gas-operated weapon Force-impulse diagram Recoil system Breech block carrier

Fully Completed Spherical Fuzzy Approach-Based Z Numbers(PHIModel)for Enhanced Group Expert Consensus

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Computers, Materials & Continua 2024年第7期80卷 1655-1675页

作者： Phi-Hung nguyen Research Center of Applied Sciences Faculty of BusinessFPT UniversityHanoi100000Vietnam

This study aims to establish an expert consensus and enhance the efficacy of decision-making processes by integrating Spherical Fuzzy Sets(SFSs)and Z-Numbers(SFZs).A novel group expert consensus technique,the PHImodel,is developed to address the inherent limitations of both SFSs and the traditional Delphi technique,particularly in uncertain,complex *** such contexts,the accuracy of expert knowledge and the confidence in their judgments are pivotal *** study provides the fundamental operational principles and aggregation operators associated with SFSs and Z-numbers,encompassing weighted geometric and arithmetic operators alongside fully developed operators tailored for SFZs ***,a case study and comparative analysis are conducted to illustrate the practicality and effectiveness of the proposed operators and *** the PHI model with SFZs numbers represents a significant advancement in decision-making frameworks reliant on expert ***,this combination serves as a comprehensive tool for decision-makers,enabling them to achieve heightened levels of consensus while concurrently assessing the reliability of expert *** case study results demonstrate the PHI model’s utility in resolving complex decision-making scenarios,showcasing its ability to improve consensus-building processes and enhance decision ***,the comparative analysis highlights the superiority of the integrated approach over traditional methodologies,underscoring its potential to revolutionize decision-making practices in uncertain environments.

关键词： Spherical fuzzy sets Delphi method Z-numbers expert consensus PHI model uncertainty

Beta-lactam antibiotic resistance among Escherichia coli isolates from patients with urinary tract infections in Vietnam:A systematic review and meta-analysis

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Asian Pacific Journal of Tropical Medicine 2024年第6期17卷 243-255,I0001-I0003页

作者： Dat T nguyen Princess Margaret Cancer Centre University Health NetworkTorontoOntarioCanada

Objective:To investigate the evolving patterns of antimicrobial resistance against beta-lactam antibiotics in Escherichia coli isolates from urinary tract infection patients in Vietnam,covering the period from 2005 to ***:29 Descriptive studies published between 2010 and 2022 in English and Vietnamese were included in the *** on resistance rates to beta-lactam antibiotics,including cephalosporins and carbapenems,were extracted and *** pooled resistance rates were calculated using random-effects *** trends in resistance were assessed using linear regression ***:Among the beta-lactam antibiotics studied,Escherichia coli exhibited varying levels of resistance,with cephalosporins showing higher resistance rates compared to *** pooled resistance rates were 66%for cefotaxime,65%for ceftriaxone,54%for ceftazidime,and 56%for *** contrast,carbapenems demonstrated lower resistance rates,with weighted pooled resistance rates ranging from 3%to 4%for meropenem,ertapenem,and *** rates were also observed for amoxicillin/clavulanate(35%),ticarcillin/clavulanate(26%),and piperacillin/tazobactam(12%).Significant annual increases in resistance were noted for imipenem(0.56%,P<0.001).Conclusions:This study highlights the critical issue of antimicrobial resistance in urinary tract infections in Vietnam and emphasizes the importance of prudent antibiotic use and the regular monitoring of resistance *** insights are useful for guiding healthcare professionals in optimizing treatment strategies and for policymakers in formulating evidence-based clinical guidelines to combat antibiotic resistance effectively.

关键词： Antimicrobial resistance Urinary tract infection Vietnam