501 research outputs found
The prospects of rainwater harvesting in the Ho CHi Minh City
Wisely using natural water resources to serve human needs plays a decisive role in ensuring water and food security. In the natural water cycle, rainwater is considered as a valuable renewable resource. Rainwater harvesting (RWH) for daily life and production is a simple but effective and also environmentally sound measure. It is also a positive solution in a climate change adaptation strategy. However, this resource is being wasted in our country in general and in the HCM City in particular. This paper provides an overview of the status of rainwater use in the world; the general situation, the potential of rainwater collection and a number of issues related to the potential of rainwater harvesting in the city. Some solutions to enhance the use of rainwater and improve water supply for city residents are also suggested in this discussion
Distribution of Quinolones, Sulfonamides, Tetracyclines in Aquatic Environment and Antibiotic Resistance in Indochina
Southeast Asia has become the center of rapid industrial development and economic growth. However, this growth has far outpaced investment in public infrastructure, leading to the unregulated release of many pollutants, including wastewater-related contaminants such as antibiotics. Antibiotics are of major concern because they can easily be released into the environment from numerous sources, and can subsequently induce development of antibiotic-resistant bacteria. Recent studies have shown that for some categories of drugs this source-to-environment antibiotic resistance relationship is more complex. This review summarizes current understanding regarding the presence of quinolones, sulfonamides, and tetracyclines in aquatic environments of Indochina and the prevalence of bacteria resistant to them. Several noteworthy findings are discussed: (1) quinolone contamination and the occurrence of quinolone resistance are not correlated; (2) occurrence of the sul sulfonamide resistance gene varies geographically; and (3) microbial diversity might be related to the rate of oxytetracycline resistance
A Cultural Study on Linguistic Metaphors of Love in Poetry
Language is one of the cultural factors. Love, an abstract concept is mainly interpreted by metaphors which are considered as part of culture. It is consequently inevitable that the linguistic metaphors of love are under the influence of culture. In this research, we centre on investigating cultural factors in linguistic metaphors of romantic love in Vietnamese modern poetry, and then compare them to those in English. It is shown in our findings that linguistic metaphors of romantic love are considerably influenced by lifestyles, habits and customs and geographical conditions. Therefore, there are many variations in the ways of expressing romantic love between Vietnamese and English although the conceptualization is chiefly similar
PRODUCTION AND SUPPLY CHAIN OF SAFE VEGETABLES IN HUONG TRA TOWN, THUA THIEN HUE PROVINCE
Abstract: On the basis of descriptive statistical methods, the authors describe the supply chain of safe vegetables in Huong Tra Town. The primary data were collected from the survey of six households providing vegetable production in the region. 40 households growing safe vegetables (20 households per ward), 40 households growing vegetables normally (20 households per ward), 10 traders purchasing processed products to provide safe vegetables for supermarkets, 5 retailers, and 10 consumers are involved in the study. The results show that Huong Tra Town is one of the main areas for growing vegetables in Thua Thien Hue province, which mainly provides safe vegetables for Hue City and neighbouring provinces. Safe vegetable products are mainly supplied for the markets in the province, especially supermarkets, restaurants, hotels and clean vegetable shops in Huong Tra Town and Hue City. In this supply chain, safe vegetable households play an important role when creating the greatest added-value. However, their real income is low due to facing the highest risks. Other actors in this supply chain receive higher benefits and facing lower risks than the producers. Households’ income depends mainly on the price and weather conditions.Keywords: safe vegetables, supply chain, Huong Tra Tow
Contribution of Manufacturing Strategy to Competitive Performance of Manufacturing Companies: Empirical Evidence from Vietnam
This paper presents the results of an empirical study examining the relationship between manufacturing strategy and competitive performance of Vietnamese manufacturers, with focus on the technology factor of manufacturing strategy. Statistical techniques were used to analyze the data collected from 25 manufacturing enterprises, and the qualitative research method was employed to enrich the captured results. Findings indicate the positive impact that manufacturing strategy (together with its components namely competitive priorities and technology choices) has on firm’s competitive performance. Two case studies also provided more in-depth knowledge of the development and implementation of manufacturing strategy at Vietnamese manufacturers. From there, recommendations are proposed for management to better implement manufacturing strategy and utilize technology in order to improve competitive performance
Halliday\u27s Functional Grammar: Philosophical Foundation and Epistemology
It is difficult to track the philosophy foundation and epistemology of systemic functional grammar (SFG) formulated by Halliday in the 1980s as this kind of grammar views language as a systemic resource for meaning. Besides, it has had global impacts on linguistics and flourished in contemporary linguistic theory. Anyone who is familiar with Halliday\u27s work realizes that his SFG is an approach designed to analyze English texts. Halliday (1994: xv) explicitly states that “to construct a grammar for purposes of text analysis: one that would make it possible to say sensible and useful things about any text, spoken or written, in modern English.” The aim of this study is not about the applicability of SFG to text analysis as many researchers and scholars do. Our efforts are made to clarify the philosophical foundation of Halliday\u27s SFG. The paper presents on triangle: (i) language, mind and world; (ii) and empiricism in Halliday\u27s SFG
Effect of loading paths on hydroforming ability of stepped hollow shaft components from double layer pipes
The step hollow shaft components are composed of two layers of different materials, they are formed using tube hydroforming process due to its high strength and rigidity, low weight and flexible profiles, compared to traditional casting, welding, and forming methods. These products are effectively used in industries such as the automotive, shipbuilding, aerospace and defense, and oil and gas sectors. The success of various double layer pipe hydroforming process depends on several factors, with the most important being the internal pressure path and axial loading path. This paper presents research on the effect of input loading paths on the hydroforming ability of a different two-layer metal structure - an outer layer of SUS304 stainless steel and an inner layer of CDA110 copper - using 3D numerical simulations on Abaqus/CAE software. Output criteria were used to evaluate the forming ability of the formed components, including Von Mises stress, Plastic strain component (PEmax), wall thinning, and pipe profile, based on which the input loading paths were combined during the forming process. These output criteria allow for more accurate predictions of material behavior during the hydroforming process, as well as deformation and stress distribution. This can support the design process, improve product quality, reduce errors, and increase production efficiency. The research results can be applied as a basis for optimizing load paths for the next experimental step in the near future, for undergraduate and graduate training, as well as allowing designers and engineers to optimize the process of hydroforming of different 2-layer tubes, reducing costs, improving accuracy, flexible design, minimizing risks, and increasing efficienc
Nucleotide variation at the methionine synthase locus in an endangered tree species, Fokienia hodginsii (Cupressaceae) in Vietnam
Nucleotide variation at the methionine synthase (MetE) locus within and among populations of an endangered forest tree Fokienia hodginsii in Vietnam was investigated in the present study. A total of 12 populations were sampled across Vietnam. The length of the sequenced locus varied from 1567 to 1559 bp. A total of 42 polymorphic sites were detected among samples. Overall, nucleotide diversity was estimated to be 0.00499 and 0.00692 at the total (ðtot) and silent sites (ðsilent) in the pool, respectively. Nucleotide diversity within populations varied from 0.00300 to 0.00521 at the total and 0.00357 to 0.00666 at silent sites. The estimates of nucleotide diversity were lower in the 4 populations located in central and southern Vietnam (0.00300 to 0.00380) in comparison with the northern populations (ranging from 0.00399 to 0.00543). Overall estimates of genetic differentiation among 12 populations were low (FST = 0.093 and KST* = 0.078), even though both values were highly significant (P < 0.001). Pairwise analysis among 12 populations showed significant genetic differentiation as evaluated by FST and Snn but not significant as evaluated by KST*. Analysis of genetic clustering using BAPS provided the best support for all 144 sequences belonging to the same genetic cluster. The implication of the results revealed in this study in the genetic conservation of F. hodginsii was discussed.Key words: Population genetics, conservation, forest, methionine synthase (MetE), structure
Estimating Disturbance Torque Effects on the Stability and Control Performance of Two-Axis Gimbal Systems
Introduction. Two-axis gimbal systems are applied for stabilizing and controlling the line of sight (LOS) of an optical or imaging system mounted on a moving vehicle. Gimbal systems are intended to isolate various disturbance torques and control the LOS toward the direction of a target. Two-axis gimbals can be of two main types, namely Yaw-Pitch and Swing-Roll type. In this article, we focus on investigating mathematical models of two-axis gimbals, which describe the impact of cross-disturbance torques on their stability and control performance. Simulations were conducted to compare advantages and disadvantages of the two types of two-axis gimbals.Aim. To study mathematical models describing the impact of cross-disturbance torques on the stability and control performance of two-axis gimbals.Materials and methods. Mathematical models of two-axis gimbal systems were synthesized by the Lagrange method. The operation of two-axis gimbal systems was simulated in the Matlab-Simulink environment. Results. Mathematical models and structural diagrams of the synthesized Yaw-Pitch and Swing-Roll gimbals were obtained. The conducted simulations of typical cases revealed different cross-disturbance effects.Conclusion. Motion equations for Swing-Roll and Yaw-Pitch gimbals were derived using similar methodology. The impact of cross-disturbance torques on gimbal systems was evaluated. The obtained results form a basis for selecting an optimal structure of tracking systems meeting the desired characteristics.Introduction. Two-axis gimbal systems are applied for stabilizing and controlling the line of sight (LOS) of an optical or imaging system mounted on a moving vehicle. Gimbal systems are intended to isolate various disturbance torques and control the LOS toward the direction of a target. Two-axis gimbals can be of two main types, namely Yaw-Pitch and Swing-Roll type. In this article, we focus on investigating mathematical models of two-axis gimbals, which describe the impact of cross-disturbance torques on their stability and control performance. Simulations were conducted to compare advantages and disadvantages of the two types of two-axis gimbals.Aim. To study mathematical models describing the impact of cross-disturbance torques on the stability and control performance of two-axis gimbals.Materials and methods. Mathematical models of two-axis gimbal systems were synthesized by the Lagrange method. The operation of two-axis gimbal systems was simulated in the Matlab-Simulink environment. Results. Mathematical models and structural diagrams of the synthesized Yaw-Pitch and Swing-Roll gimbals were obtained. The conducted simulations of typical cases revealed different cross-disturbance effects.Conclusion. Motion equations for Swing-Roll and Yaw-Pitch gimbals were derived using similar methodology. The impact of cross-disturbance torques on gimbal systems was evaluated. The obtained results form a basis for selecting an optimal structure of tracking systems meeting the desired characteristics
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