117 research outputs found
Groundwork-Based Research to Design Application SCC - Building a Sustainable Community for Children in Mountainous Area
Children’s clothing is a prime example of fast fashion, as their continuous growth requires frequent purchases. This not only impacts the environment but also puts financial strain on parents. Concurrently, many highland children lack essential material and educational resources, contributing to poverty in the region. To address these challenges, local authorities urgently require a sustainable solution that supports children, communities, and localities, fostering comprehensive development. The project development criteria are evaluated based on the United Nations’ 17 sustainable development goals (SDGs). Data was collected through an online survey of 50 married individuals, 162 non-married individuals, and interviews with those who have organized events for children in the highlands. Additionally, insights were obtained from three children from disadvantaged areas. The results indicate that all target groups show a keen interest in social activities for children. Parents facing difficulties accessing charities, and the lack of effective collaboration between charities and local authorities, hinders sustainable development efforts.
Keywords: children, SDG, social sustainabilty, communit
Effect of Rare Earth on M7C3 Eutectic Carbide in 13% Chromium Alloy Cast Iron
The crystallization process of hypoeutectic white cast iron consists of the first secreted austenite branch after the reaction of the austenite -carbide crystal is formed, and the phase crystal fills in the middle of the austenite branches. If the austenite branches are small and smooth, the crystals carbide are fine. The cast iron with 13% chromium which has 3 – 3.2% carbon, have the carbide crystalline as M7C3. The elements in rare earth have a strong affinity for oxygen and sulfur to produce rare earth oxides. These rare earth oxides can create heterogeneous germ center for austenite phases and smooth down these phases. The effect of rare earth on the M7C3 and crystals of 13% chrome white iron has been elucidated. Along with the increase of rare earth content, the microstructure of M7C3 with fine finely graded, more uniformly distributed, dispersed throughout the sample surface. When the carbide is fine and dispersion, will contribute to improving the properties of cast iron especially the impact strength as well as the abrasion resistance of the alloy. The research results show that in the presence of rare earth, rare earth elements created with oxygen and form La2O3 and Ce2O3 as the nucleation for the solidification process and create the small fineness of phases. The orientation of the crystal structure of these oxides is similar to the crystal structure orientation of Fe-γ phase. Finding and proving the oxides of rare earth has crystal structure with phase γ which will be small smooth exogenous minds that the microstructure has a smooth, small size
INFLUENCE OF SYNTHESIS FACTORS ON PROPERTIES OF GEOPOLYMERS BASED ON RED MUD AND RICE HUSK ASH
In this paper, the effect of mixing ratio of raw materials, curing temperature and time on geopolymerization between red mud and rice husk ash were investigated. The results showed that the optimum conditions were SiO2/Al2O3 ratio of 4 and Na2O/Al2O3 ratio of 2.0, curing temperature of 100oC and curing time of 24 hours. The compressive strength, bulk density, total shrinkage of the obtained product were 22.8 MPa, 2.39 g.cm-3, 15%, respectively that met requirement of unsintered bricks using for construction
A STUDY ON THE SYNTHESIS OF MgAl2O4 SPINEL BY STARCH ASSISTED SOL-GEL PROCESS
In this paper, the synthesis of ceramic spinel MgAl2O4 by starch assisted sol - gel process is presented. The gel mixture was prepared by using Mg(NO3)2.6H2O, Al(NO3)3.9H2O as precursors and starch as a gel agent. The study focused on relevant components of gel mixture and the calcinating temperature. The results showed that suitable molar proportion of Mg2+/Al3+; starch/(Mg2+ + Al3+) and H2O/starch were 0.5, 0.4 and 60, respectively. The calcination at 1100 oC for 60 minutes was suitable for forming phase of spinel. The product was a single phase of spinel MgAl2O4 with excellent crystallinity and uniform size in the range of 300 to 400 nm
Geometrically nonlinear buckling analysis of truss with length imperfection subjected to mechanical and thermal load using hybrid FEM
This paper presents a novel hybrid FEM-based approach to establish the mathematical model for solving the nonlinear buckling problem of truss systems with length imperfection under mechanical and thermal load. due to constant temperature change-based hybrid FEM. The proposed approach deals with establishing hybrid types of truss elements, including perfect truss elements without thermal deformation and truss elements with length imperfection and thermal deformation. The equilibrium equation of both truss elements is established based on compatibility relationships considering geometric nonlinearity. The hybrid global equilibrium equations of truss systems are developed by assembling constructed perfect truss elements without thermal deformation and truss elements with length imperfection and thermal deformation. The incremental-iterative algorithm based on the arc-length method is used to establish calculation programs to solve the hybrid global equilibrium equation for investigating the geometrically nonlinear buckling behavior of the truss system. The numerical test is presented to investigate the buckling and post-buckling behavior of truss systems having some elements with length imperfection under thermal and mechanical load
RESEARCH ON THE MANUFACTURING MAGNESIUM FROM THANHHOA DOLOMITE BY PIDGEON PROCESS
The magnesium and magnesium alloys has applied widely in different industrial aspects in Vietnam in the modern life. Especially, the products from magnesium alloys implementing in the automotive have increased rapidly since the car elements tend to be generated by the light alloys in order to save the fuel. However, in the current time, Vietnam has no factories to produce the magnesium to adapt the domestic demand although it owns an enrich resource of raw materials. This research indicates the possibility of using the dolomite ore in Thanhhoa – Vietnam to make the magnesium as well as evaluate the primary factors like recovering temperature, reducing agent rate, recovering time having effect on the reduction efficiency of Thanhhoa dolomite by metallothermic method in vacuum (Pidgeon Process). This is basic process, low investment and suitable for the small and medium scales in Vietnam. The experiment includes heating, indicating the chemical ingredients and recovering experiment on the dolomite after calcination (dolime) by using ferrosilicon. The thermodynamic model is created to estimate the recovering efficiency in the Pidgeon. The result shows that the CaO/MgO molar ratio of calcination dolomite in Thanhhoa is nearly 1.5 which is suitable to produce magnesium in the case of highly-required efficiency and pureness. Besides, the result from the furnace of the experiment is lower than the one in the model. The samples are set up to check the influence of the rate of ferrosilicon in the compound. The result indicates that the ideal efficiency reaches 85 % with 30 % ferrosilicon. Moreover, the study confirms that the optimal operating conditions in this process are recovering during three hours at 1200 °C and 100 Pa pressure. This result proves the potential application of Thanhhoa dolomite in the industry suitable with the current condition in Vietna
Developing a comprehensive quality control framework for roadway bridge management: a case study approach using key performance indicators
Transportation infrastructures, especially roadway bridges, play a pivotal role in socioeconomic development. Recently, bridge engineers are increasingly facing the challenge in terms of shifting their strategy from building new facilities to maintaining the existing aging infrastructures, to preserve their service performance during the operational stage. In fact, the infrastructure administrators lack a quality control (QC) strategy for the existing roadway bridges, which leads to the decision-making application and tool being still minor. To overcome those
challenging issues, this paper proposes a quality control framework for roadway bridge management using key performance indicators (KPIs). The case study methodology is suggested to be used and then conducted for several bridges, mostly in European countries. In which the performance indicators (PIs) and goals (PGs) are defined, after assessing the bridges and vulnerable zones, the derivation KPIs from those PIs are introduced and developed considering time functions and different maintenance scenarios. Eventually, a two-stage quality control framework will be proposed in which the static stage includes preparatory works, inspection responsibilities, and a quick assessment of KPIs; while the dynamic stage helps the decision maker in estimating the time remaining of the bridge service life, managing the evolution of KPIs as well as planning the best possible maintenance strategy. The selected two case studies are present and curated, which show
the excellent potential to develop a long-term strategy for roadway bridge management on a lifecycle level.This research was funded by FCT/MCTES through national funds (PIDDAC) from the
R&D Unit Institute for Sustainability and Innovation in Structural Engineering (ISISE), under the
reference UIDB/04029/2020, and from the Associate Laboratory Advanced Production and
Intelligent Systems ARISE, under the reference LA/P/0112/2020, as well as financial support of the
project re-search “B2022-GHA-03” from the Ministry of Education and Training. And The APC was
funded by ANI (“Agência Nacional de Inovação”) through the financial support given to the R&D
Project “GOA Bridge Management System—Bridge Intelligence”, with reference PO-CI-01-0247-
FEDER-069642, which was cofinanced by the European Regional Development Fund (FEDER)
through the Operational Competitiveness and Internationalisation Program (POCI).Minh Q. Tran acknowledges the support by the doctoral grant reference
PRT/BD/154268/2022, financed by Portuguese Foundation for Science and Technology (FCT), under
the MIT Portugal Program (2022 MPP2030-FCT)
Finite element model updating for composite plate structures using particle swarm optimization algorithm
In the Architecture, Engineering, and Construction (AEC) industry, particularly civil
engineering, the Finite Element Method (FEM) is a widely applied method for computational
designs. In this regard, computational simulation has increasingly become challenging due to
uncertain parameters, significantly affecting structural analysis and evaluation results, especially
for composite and complex structures. Therefore, determining the exact computational parameters
is crucial since the structures involve many components with different material properties, even
removing some additional components affects the calculation results. This study presents a solution
to increase the accuracy of the finite element (FE) model using a swarm intelligence-based approach
called the particle swarm optimization (PSO) algorithm. The FE model is created based on the
structure’s easily observable characteristics, in which uncertainty parameters are assumed
empirically and will be updated via PSO using dynamic experimental results. The results show that
the finite element model achieves high accuracy, significantly improved after updating (shown by
the evaluation parameters presented in the article). In this way, a precise and reliable model can be
applied to reliability analysis and structural design optimization tasks. During this research project,
the FE model considering the PSO algorithm was integrated into an actual bridge’s structural health
monitoring (SHM) system, which was the premise for creating the initial digital twin model for the
advanced digital twinning technologyThis work was partly financed by FCT/MCTES through national funds (PIDDAC) under the R&D Unit Institute for Sustainability and Innovation in Structural Engineering (ISISE), under reference UIDB/04029/2020, and under the Associate Laboratory Advanced Production and Intelligent Systems ARISE under reference LA/P/0112/2020. The authors also acknowledge ANI (“Agência Nacional de Inovação”) for the financial support given to the R&D Project “GOA Bridge Management System—Bridge Intelligence”, with reference POCI-01-0247-FEDER-069642,
cofinanced by the European Regional Development Fund (FEDER) through the Operational Competitiveness and Internationalization Program (POCI).Minh Q. Tran was supported by the doctoral grant reference PRT/BD/154268/2022 financed by the Portuguese Foundation for Science and Technology (FCT), under the MIT Portugal Program (2022 MPP2030-FCT). Minh Q. Tran acknowledges Huan X. Nguyen (Faculty of Science and Technology, Middlesex University, London NW4 4BT, UK) and Thuc V. Ngo (Mien Tay Construction University, Institute of Science and International Cooperation, 85100 Vĩnh Long, Vietnam) for their support as cosupervisors as well as specific suggestions in terms of the “conceptualization” and “methodology” of this paper. Helder S. Sousa acknowledges the funding by FCT through the Scientific Employment Stimulus—4th Editio
MULTI-PIXEL PHOTON COUNTER FOR OPERATING A TABLETOP COSMIC RAY DETECTOR UNDER LOOSELY CONTROLLED CONDITIONS
The multi-pixel photon counter (MPPC) has recently emerged as a great type of silicon photomultiplier to replace or compensate for conventional vacuum-based photomultiplier tubes. An MPPC provides many advantageous features, such as high electrical gain, outstanding photon detection efficiency, fast timing response, immunity to magnetic fields, low-voltage operation, compactness, portability, and cost-effectiveness. This article examines the electrical and optical characteristics of an MPPC under loosely controlled environmental conditions. We also report a measurement of the light yield captured by the MPPC when a cosmic ray passes through the plastic scintillator, demonstrating that such a setup is suitable as a simple, cost-effective tabletop cosmic ray detector for educational and research purposes
The acceptability of and willingness to pay for a herpes zoster vaccine: A systematic review
Patients, predominantly the elderly, with Herpes Zoster (HZ) not only suffer symptoms of the disease but also bear considerable expenses. This study systematically reviewed the acceptability of and willingness to pay for the HZ vaccine. This review was registered in PROSPERO 2023 (CRD42023403062). We used “acceptance”, “willing to pay”, and “HZ vaccine” (and variations thereof) as keywords in a systematic search for original English research articles published up to April 7, 2023. The search was conducted over Scopus, PubMed, ScienceDirect, Cochrane, and Google Scholar in accordance with PRISMA 2020 guidelines. The inclusion criteria were as follows: studies (1) that mentioned HZ vaccination, (2) related to acceptability or willingness to pay, and (3) with full texts available and peer-reviewed prior to final publication. Grey literature, letters to editors, commentaries, case reports or series, systematic reviews, meta-analyses, articles of poor quality, and articles with ambiguously defined and measured outcome variables were excluded. The Joanna Briggs Institute (JBI) critical appraisal checklist was used to evaluate the methodological quality of the studies. Finally, the search yielded 24 studies, of which 9 were conducted in Asia, 8 in Europe, and 7 in America. General adults or patients aged 50 or older were often the target populations, for whom treatments were accompanied by healthcare providers’ recommendations. The willingness to pay and willingness to accept the vaccine ranged from 150 and 16.6% to 85.8%, respectively. Compared to the US, Asia and Europe had higher acceptance rates for HZ immunization. The most frequent excuses given for not being vaccinated are side effects, cost, lack of recommendations, anti-vaccination views, ignorance about the HZ vaccine, and the belief that one is not at risk for the disease. National campaigns should be developed to increase public awareness of HZ, and more international research should be conducted to understand the WTA and WTP for HZ immunizations
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