The grindability of segmented grinding wheels produced by Vietnam in rough machining aluminum material

Recently developed in Vietnam segmented grinding wheels is base on the fundamental of discontinuous machining is used to enhance the grindability of abrasive grains. The phenomenon of grinding chips adhesive to space between grains, that make the wheels became "dull", was reduce, special machining aluminum. In this paper, the evalution of segmented grinding wheel is based on the cutting performance. η is defined as a ratio between the discontinued regions and the of the grinding wheel’s working surface. There were five newly developed grinding wheels with (10.91%, 16.37%, 18.19%, 20.01% and 21.83% respectively) and one conventional η different η = 0%) were used to grind unhardened steel, hardened steel and aluminum. The results showed η grinding wheel (that segmented grinding wheels obtained a smoother surface in compared with conventional η = 20,01% for machining unhardened steel and at η = 18,19% machining aluminum material. On the other hand, segmented wheels with a less number of abrasive grains, show a higher efficiency for obtaining the smoother surface roughness than conventional wheels in the same working conditions. However, the mechanism of machining hardened and aluminum materials is a little bit different.В статье рассматриваются сегментированные шлифовальные круги, разработанные недавно во Вьетнаме с опорой на основы прерывистой механической обработки, с целью повышения шлифующей способности зерен. Явление "засаливания" шлифовального круга, возникающее при налипании шлифованной стружки в межзеренном пространстве, при использовании таких кругов уменьшается, особенно при обработке алюминия. Исследовались круги с различным соотношением прерывистых участков и рабочей поверхности круга. Испытания кругов проводились для алюминиевого сплава, а также закаленной и незакаленной стали при различных режимах обработки, при этом выявлены некоторые отличия в механизме механической обработки

Spatial Clustering Analysis Of Dengue Hemorrhagic Fever In The First 9-Monthsof 2023 In Ho Chi Minh City, Vietnam

Background: Dengue hemorrhagic fever is a notable vector-borne viral disease, currently becoming the most dreaded worldwide health problem in terms of the number of people affected. The objective of this study is to investigate spatial clustering of dengue hemorrhagic fever incidence in the first 9-months of 2023 in Ho Chi Minh city, Vietnam. Methods: the global Moran’s I statistic, Moran’s I scatterplot and local statistic were employed to spatial clusters (high-high and low-low) and spatial outliers (low-high and high-low) in the study area of Ho Chi Minh city. The first and third order of contiguity were used to constructe spatial weight matrix. Results: it was found from a case study of the first 9-months of 2023 in Ho Chi Minh city, a total of four high-high clusters, two low-low spatial clusters were detected in urban area and rural areas in the north and south of the Ho Chi Minh city, respectively when using the first order contiguity (statistically significance at the 0.05 level). For the case of using the third order of contiguity, a total of six high-low, two low-high spatial clusters and one low-low spatial cluster were successfully identified. Conclusions: the study results has proven the effective use of the global Moran’s I statistic, Moran’s I scatterplot and local Moran’s I statistic in the identification of spatial clustering of dengue hemorrhagic fever incidence

ENCHANCING THE EFFICIENCY OF HUMAN RESOURCE MANAGEMENT THROUGH A.I

With the rapid development of the Information Technology industry, Artificial Intelligence (AI) and Machine Learning (ML) are becoming the most popular keywords in the modern world. Companies around the world as well as in Vietnam have been finding powerful applications of Artificial Intelligence in their daily operation, especially in human resource management and development. AI application not only helps organizations to optimize their processes and increase performance, but also creates a flexible working environment and a better experience for employees. However, along with those benefits, the application of AI also creates new challenges, requiring organizations to consider and prepare carefully before applying new technology. This article will delve into the benefits and challenges of applying AI in human resource management, thereby helping businesses form and develop appropriate strategies in the future

Integrated teaching in primary schools: A systematic review of current practices, barriers, and future developments

Recent years have seen a rise in the use of integrated teaching in many nations across the globe due to the vital role it plays in the delivery of primary education programs that focus on the growth of students’ abilities. However, a comprehensive review of integrated classroom practices in elementary schools has yet to be conducted, making it difficult for interested readers to make education decisions about entering the sector or for established experts to keep up with the latest developments. To fill this gap, we performed a meta-analysis using the PRISMA procedure and a comprehensive literature search. Following the PRISMA guidelines, the study analyzed 24 publications on integrated teaching in primary school that appeared in Scopus and Google Scholar between 2014 and 2022. The study used text analysis and synthesis to highlight active nations, extracted keywords, drawing obstacles and challenges, and future research opportunities. The result reported 13 types of obstacles and challenges that need to be overcome in the long run. As such, five research directions were compiled based on prior publications, namely as teachers’ training program, integrated teaching materials, integrated teaching models, school policies and other interventions, and others. Interested readers, prospective researchers and policymakers could benefit from these findings by tackling existing issues or investigating recommended research directions

SOME DEFINITIONS FOR CONVOLUTIONS AND THE CONVOLUTIONS FOR THE FOURIER TRANSFORMS WITH GEOMETRIC VARIABLES

Joint Research on Environmental Science and Technology for the Eart

Convolution for the transform induced by Fourier integral transform and its inverse

Joint Research on Environmental Science and Technology for the Eart

Evaluation of plant growth regulators on root formation of semihardwood and hardwood cuttings of Sarcandra glabra (Thunb.) Nakai

The aim of this study is to evaluate the effects of three types of plant growth regulators (α- naphthyl acetic acid, indole-3-acetic acid and β-indol butyric acid) on the root formation of the semihardwood and hardwood cuttings of Sarcandra glabra (Thunb.) Nakai. The effects of plant growth regulators on root formation were evaluated based on living percentage, rooting percentage, secondary rooting percentage, and the number and the length of roots. The results showed that the best root growth regulator was β-IBA. The overall effective concentrations of growth regulators were 1.0 and 1.5%. The living percentage of the semihardwood cuttings was lower than that of the hardwood cuttings. However, the root growth parameters of the semihardwood cuttings were better than those of the hardwood cuttings.

On solutions of integral equations with reflections

Приводится алгебраический метод решения сингулярных интегральных уравнений в замкнутой форме

Factors Affecting the Perception of Happiness among Teachers in Vietnam

Vietnam is in the process of implementing education reforms in which teachers play a crucial role in determining success. This study aims to identify the main factors influencing the perception of happiness at work of Vietnamese teachers during the period of educational reform. In any period, teachers are always considered as being the force behind the success of education. Therefore, teachers' happiness is the most vital factor to be taken into consideration when educating students. Identifying the factors that affect teachers' happiness at work is the key to improving their teaching quality and quality of life. This study was conducted to investigate the factors affecting the perceived happiness of secondary school teachers in Vietnam today, thereby objectively assessing the emotional status of teachers in Vietnam in relation to the work they are doing. The results are as follows: 1) Teachers face a lot of pressure from many sides; 2) There is still a large percentage of teachers who do not really attach importance to the teaching profession; 3) State policies have not helped teachers feel secure in their professional activities; 4) Teacher capacity still needs to be greatly improved; 5) It is necessary to strengthen the connection between teachers, educational leaders, policy makers, school administrators and colleagues. This study uses descriptive statistics to present the research results. The survey was carried out in September 2021