Analysis of tool wear and surface roughness in high-speed milling process of aluminum alloy Al6061

In this study, the influence of cutting parameters and machining time on the tool wear and surface roughness was investigated in high-speed milling process of Al6061 using face carbide inserts. Taguchi experimental matrix (L9) was chosen to design and conduct the experimental research with three input parameters (feed rate, cutting speed, and axial depth of cut). Tool wear (VB) and surface roughness (Ra) after different machining strokes (after 10, 30, and 50 machining strokes) were selected as the output parameters. In almost cases of high-speed face milling process, the most significant factor that influenced on the tool wear was cutting speed (84.94 % after 10 machining strokes, 52.13 % after 30 machining strokes, and 68.58 % after 50 machining strokes), and the most significant factors that influenced on the surface roughness were depth of cut and feed rate (70.54 % after 10 machining strokes, 43.28 % after 30 machining strokes, and 30.97 % after 50 machining strokes for depth of cut. And 22.01 % after 10 machining strokes, 44.39 % after 30 machining strokes, and 66.58 % after 50 machining strokes for feed rate). Linear regression was the most suitable regression of VB and Ra with the determination coefficients (R2) from 88.00 % to 91.99 % for VB, and from 90.24 % to 96.84 % for Ra. These regression models were successfully verified by comparison between predicted and measured results of VB and Ra. Besides, the relationship of VB, Ra, and different machining strokes was also investigated and evaluated. Tool wear, surface roughness models, and their relationship that were found in this study can be used to improve the surface quality and reduce the tool wear in the high-speed face milling of aluminum alloy Al606

STUDIES OF THE BENTHIC MACROINVERTEBRATE FOR WATER QUALITY MONITORING IN CAN GIO-HCMC

Joint Research on Environmental Science and Technology for the Eart

INFLUENCE OF MOTIVATION, SOCIAL SUPPORT AND BASIC NEED SATISFACTION ON BURNOUT AMONG FOOTBALL PLAYERS IN BANGLADESH

Football is ruminated in the guise of the most foremost and modish sports in Bangladesh reminiscent of other countries of the world, as sports are frolicked under prodigious coercion, young football athletes perpetually stumble into divergent circumstances which incorporate affirmative and apathetic scenarios confiding in athlete’s concurrent whereabouts & prospect dispatch which narrates to burnout. The perusal maneuvered motivation as an independent variable, basic need satisfaction which exerted as mediator variable and social support plied as moderator variable that governed young player’s burnout to ebb or to surge. The purpose of the study was to interrogate the relationship among burnout and motivation, social support, basic need satisfaction. The paper pursued quantitative technique to amass accessible data in which five hundred and twelve adolescent football players were surveyed in Bangladesh and their age ranged between 15 to 25 years. The survey questionnaire was in four tranches encompassing Athlete burnout questionnaire, Basic Need Satisfaction scale, Motivation questionnaire & SARASON Social Support scale; furthermore, the study wielded Pearson Correlation analysis, Moderated regression analysis and Process in the course of score reckoning. The study instituted that motivation and social support unconstructively associated with burnout and basic need satisfaction allied moderately with the burnout, when burnout escalates, motivation, social support, and basic need satisfaction went down or when burnout dwindles all of the independent variables augment. The research formed factors relationship with each other and comprehended coping tactic how athletes could trounce their melancholy, fatigue and mental grievance to burgeon their sports recital and would scrutinize players commotion towards their contented & constructive precinct as well.  Article visualizations

DESIGNING HEDGE ALGEBRAIC CONTROLLER AND OPTIMIZING BY GENETIC ALGORITHM FOR SERIAL ROBOTS ADHERING TRAJECTORIES

In recent years, the application of hedge algebras in the field of control has been studied. The results show that this approach has many advantages. In additions, industrial robots are being well-developed and extensively used, especially in the industrial revolution 4.0. Accurate control of industrial robots is a class of problems that many scientists are interested in. In this paper, we design a controller based on hedge algebra for serial robots. The control rule is given by linguistic rule base system. The goal is to accurately control the moving robot arm which adheres given trajectories. Optimization of fuzzy parameters for the controller is done by genetic algorithms. The system has been simulated on the Matlab-Simulink software. The simulation results show that the orbital deviation is very small. Moreover, the controller worked well with correct control quality. This result once presents the simplicity and efficiency of the hedge algebras approach to control

INFLUENCE OF MOTIVATION, SOCIAL SUPPORT AND BASIC NEED SATISFACTION ON BURNOUT AMONG FOOTBALL PLAYERS IN BANGLADESH

Football is ruminated in the guise of the most foremost and modish sports in Bangladesh reminiscent of other countries of the world, as sports are frolicked under prodigious coercion, young football athletes perpetually stumble into divergent circumstances which incorporate affirmative and apathetic scenarios confiding in athlete’s concurrent whereabouts & prospect dispatch which narrates to burnout. The perusal maneuvered motivation as an independent variable, basic need satisfaction which exerted as mediator variable and social support plied as moderator variable that governed young player’s burnout to ebb or to surge. The purpose of the study was to interrogate the relationship among burnout and motivation, social support, basic need satisfaction. The paper pursued quantitative technique to amass accessible data in which five hundred and twelve adolescent football players were surveyed in Bangladesh and their age ranged between 15 to 25 years. The survey questionnaire was in four tranches encompassing Athlete burnout questionnaire, Basic Need Satisfaction scale, Motivation questionnaire & SARASON Social Support scale; furthermore, the study wielded Pearson Correlation analysis, Moderated regression analysis and Process in the course of score reckoning. The study instituted that motivation and social support unconstructively associated with burnout and basic need satisfaction allied moderately with the burnout, when burnout escalates, motivation, social support, and basic need satisfaction went down or when burnout dwindles all of the independent variables augment. The research formed factors relationship with each other and comprehended coping tactic how athletes could trounce their melancholy, fatigue and mental grievance to burgeon their sports recital and would scrutinize players commotion towards their contented & constructive precinct as well

Analysis of flow characteristics of cylindrical and helical type multi-lobe roots blower

Roots blower is a positive displacement machine that has the advantage of a larger flow than conventional blowers. Roots blowers are widely used in industrial production such as chemicals, food, medical, etc. However, during actual operation, this type of machine often achieves low performance. One of the issues that greatly affect performance is the flow characteristics of the blower. Flow characteristics include factors related to flow rate, pressure, and flow phenomena in the blower chamber. Flow characteristic analysis is a complex problem in hydraulic machines. Flow analysis helps to investigate the motion of the flow to design high-performance machines. This study uses a mathematical model of gear theory to design the rotor profile with cylindrical and helical lobes of the multi-lobe Roots blower. The rotor profile is formed on the principle that the ellipse rolls without slipping on the base circle. On the basis of the mathematical model of the rotor profile, the paper compares the flow rate and pressure characteristics of the two blowers. The fluid dynamics analysis model was built on ANSYS software. The structural grid model is also built to increase the computational efficiency of the mathematical model. The lobes are embedded and rotated in the blower chamber. The results show that with the same radial and axial dimensions, the cylindrical lobe has a larger flow. However, the helical lobe has a more stable flow quality than the cylindrical lobe (15.2 % less flow fluctuation). In terms of pressure, the helical lobe type has a higher pressure than the cylindrical lobe type. In addition, the helical lobe type also reduces the influence of eddy currents acting on the blower chamber walls and rotors. That results in increased blower efficiency. The results of the paper will be a reliable basis for reducing time in the development of multi-lobe Roots blowers with high performanc

Diversity of plant-parasitic nematodes on medicinal plants in Melinh station for biodiversity, Vinh Phuc Province, Vietnam

Plant-parasitic nematodes are known as one of the most important pests attacking various plants in the world, and investigating the nematode component is very essential for management of this pest and prevent damage to plants in general. Our survey of plant-parasitic nematodes on medicinal plants in Melinh Station for Biodiversity, a place for conservation of precious plants and animals in Vietnam, identified ten species that belong to nine genera, five families, and two orders of plant-parasitic nematodes parasitizing six medicinal plants. Excoecaria cochinchinensis was parasitized by the highest number of nematode genera (5 genera, including Xiphinema, Discocriconemella, Meloidogyne, Helicotylenchus, and Hemicriconemoides), while Hymenocallis littoralis was associated with the highest number of plant-parasitic nematodes (2060 nematodes/250g soil). The results also showed that Discocriconemella limitanea was found to be a dominant species with the highest number of individuals on 6 medicinal plants, and the genus Helicotylenchus had the highest frequency of appearance (5/6 plants or 83.3%). These nematodes caused symptoms such as yellowing leaves, root galls, and root lesions, which directly affect the quality and yield of medicinal plants. Based on the results, this study showed that plant-parasitic nematodes are a potential threat to the cultivation of medicinal plants in Melinh Station for Biodiversity, and thus, control measures should be applied to ensure sustainable cultivation of medicinal plants in this place

RESEARCH ON FACTORS INFLUENCING THE INTENT TO USE NETFLIX MOVIES IN VIETNAM

Abstract The Netflix movies market is steadily growing, especially during the complex COVID-19 pandemic. Consumers, instead of opting for free movie streaming services with potential risks and copyright violations, are choosing to pay for a better experience while emphasizing responsibility for protecting copyrights and supporting authors and producers. This research aims to examine the factors influencing the intent to use Netflix movie streaming services among surveyed individuals, primarily focusing on employees aged 18 to 22 in Vietnam. Participants were surveyed through online and offline questionnaires. The author conducted logistic regression analysis, treating the use of Netflix movies as the dependent variable, with five independent variables sourced from a literature review. Through online and offline survey questionnaires and multivariate regression models, the study identified and concluded the factors influencing employees' intent to use Netflix movie streaming services in Vietnam. Data were quantitatively analyzed using IBM SPSS 20.0. The research results identified five positively influencing factors on the intent to use Netflix movie streaming services: Price perception, Risk perception, Attitude, Ethical awareness, Subjective norms. Among these factors, Price perception had the strongest influence on the intent to use Netflix movies, while the Subjective norms factor was found to be insignificant. Consequently, the article suggests managerial implications for businesses to attract customers and promote the Netflix movies market