Development of solid-shell elements for large deformation simulation and springback prediction

Objective of the thesis is to develop a finite element that is effective for simulation of thin-walled behavior, such as in metal forming processes. The thesis includes six chapters and is structured as follows. The first chapter presents the objects for the research. The second chapter introduces background methods which will be incorporated in the solid-shell elements. The third chapter develops an alternative ANS technique and applies it to the solid-shell elements. As a result, in that chapter a new solid-shell element based on the alternative ANS technique is proposed. Elastic applications of the just developed solid-shell element are illustrated in Chapter 4. In Chapter 5, plasticity theory and numerical problems in plasticity deformation are presented. The thesis specially concentrates on treating a current industrial problem: spring back prediction. Results in Chapter 4 and Chapter 5 demonstrate the capabilities of the proposed solid-shell element. Chapter 6 withdraws conclusions and then makes some remarkable future developments

Unravelling the functional biomechanics of dental features and tooth wear

Most of the morphological features recognized in hominin teeth, particularly the topography of the occlusal surface, are generally interpreted as an evolutionary functional adaptation for mechanical food processing. In this respect, we can also expect that the general architecture of a tooth reflects a response to withstand the high stresses produced during masticatory loadings. Here we use an engineering approach, finite element analysis (FEA), with an advanced loading concept derived from individual occlusal wear information to evaluate whether some dental traits usually found in hominin and extant great ape molars, such as the trigonid crest, the entoconid-hypoconulid crest and the protostylid have important biomechanical implications. For this purpose, FEA was applied to 3D digital models of three Gorilla gorilla lower second molars (M2) differing in wear stages. Our results show that in unworn and slightly worn M2s tensile stresses concentrate in the grooves of the occlusal surface. In such condition, the trigonid and the entoconid-hypoconulid crests act to reinforce the crown locally against stresses produced along the mesiodistal groove. Similarly, the protostylid is shaped like a buttress to suffer the high tensile stresses concentrated in the deep buccal groove. These dental traits are less functional in the worn M2, because tensile stresses decrease physiologically in the crown with progressing wear due to the enlargement of antagonistic contact areas and changes in loading direction from oblique to nearly parallel direction to the dental axis. This suggests that the wear process might have a crucial influence in the evolution and structural adaptation of molars enabling to endure bite stresses and reduce tooth failure throughout the lifetime of an individual

Enzyme-Assisted Aqueous Extraction Of Cashew Nut (Anacardium occidentale L.) Oil

Enzyme-assisted aqueous extraction method was applied to extract oil from cashew nut (Anacardium occidentale L.). The commercial enzyme (Viscozyme cassava C) was tested for effectiveness in releasing oil during the aqueous extraction. The effect of several parameters such as material/water ratio, enzyme concentration and duration for enzyme incubation on the oil yield was investigated. The conditions for maximum oil release were found with the material/water ratio of 1:9, enzyme concentration of 1% (v/w E/S), and in 3 h of enzyme incubation at 50oC with constant shaking. The maximum oil yield obtained at those conditions (38.88 % raw material) was significantly (p <0.05) higher than that of the control (without enzyme) (35.92 %), and it represented 86.28 % recovery of the total oil in seed. No hexane and other organic solvents were needed for this process. The cashew nut oil by enzyme-assisted aqueous extraction was relatively stable. Both peroxide value and free fatty acid value were lower than those in the oil obtained by Soxhlet method. Total un-saturated fatty acid in the cashew nut oil was about 84.43 %, in which the most abundant was oleic acid (65.0 %), followed by linoleic acid (18.53%). Cashew nut oil is a good dietary source of un-saturated fatty acids

Mosaic Atlas: Interview with Trami Cron

Interview with Trami Nguyen Cron, Executive Artistic Director of Chopsticks Alley Art. She identifies as Vietnamese American. She is an author and directs the hub, Chopsticks Alley Art, promoting Southeast Asian art and culture. Topics discussed inclue the work of the organization, the move to Downtown San Jose, her books, including VietnamEAZY: A Novel about Mothers, Daughters, and Food, the importance of representation in the arts for the Vietnamese communities, Tet, and extension to broader Southeast Asian audiences. As part of the Mosaic Atlas project, SJSU students and faculty from the Anthropology and Geography Departments interviewed people who support and produce art throughout the Bay Area

The need for values education programs for both pre-service teachers and in-service teachers in Vietnam

This paper investigates the perceptions of pre-service teachers and in-service teachers regarding the concept of 'values education' and the preparation of values education in professional programs in Vietnam. Furthermore, the pedagogical strategies employed by teachers in addressing values education situations in their classrooms are explored. A qualitative research design was employed, involving interviews with forty-three pre-service teachers from a university. Additionally, eighteen teachers from two different high schools were interviewed, and their teaching sessions, along with school assemblies, were observed. The findings reveal that values education is primarily understood as the instruction of living skills and moral education. There is a lack of conceptualization and knowledge regarding values education among the participants. Both pre-service teachers and in-service teachers did not receive formal values education programs during their university education, and the support provided by schools in this regard was limited. Teachers tended to integrate values education into subjects randomly and subjectively, without employing advanced strategies. Inconsistencies in implementation and challenges associated with teaching values were observed. Highlighting an urgent necessity, this article emphasizes the imperative need for values education programs tailored for both pre-service and in-service teachers in Vietnam. It underscores the significance of adequately equipping teachers to effectively address values education in their classroom

Modified Dijkstra's Routing Algorithm for Security with Different Trust Degrees

A great number of efficient methods to improve the performance of the networks have been proposed in physical-layer security for wireless communications. So far, the security and privacy in wireless communications is optimized based on a fixed assumption about the trustworthiness or trust degrees (TD) of certain wireless nodes. The nodes are often classified into different types such as eavesdroppers, untrusted relays, and trusted cooperative nodes. Wireless nodes in different networks do not completely trust each other when cooperating or relaying information for each other. Optimizing the network based on trust degrees plays an important role in improving the security and privacy for the modern wireless network. We proposed a novel algorithm to find the route with the smallest total transmission time from the source to the destination and still guarantee that the accumulated TD is larger than a trust degree threshold. Simulation results are presented to analyze the affects of the transmit SNR, node density, and TD threshold on different network performance elements

SKILLS TO COPE WITH LEARNING STRESS OF STUDENTS IN CAN THO UNIVERSITY, VIETNAM

The research on the topic has systematized the theoretical basis of students' skills to cope with stress in learning. Currently, students face a lot of pressure and stress in their studies, so coping skills are an extremely important issue and need attention. The study presents the manifestations of skills to cope with stress in the learning of students of School of Education at Can Tho University (CTU), Vietnam. The research mainly uses a questionnaire survey method with 400 students from various fields of study, SoE, CTU. According to survey results, there were many manifestations of stress that students encountered. The survey results are the basis for finding the causes so students can plan and manage their time, set specific goals to find effective remedies, adapt and manage better emotions. From the current situation of the problem, the study has proposed measures to support students' skills to cope with stress in their studies. This study provides recommendations to deploy and apply the research results to Can Tho University lecturers and students as well.  Article visualizations

SOCIAL-EMOTIONAL SKILLS IN STUDENTS’ LEARNING IN CAN THO UNIVERSITY, VIETNAM

Based on an overview of domestic and foreign research related to the research field of the topic; the research of the topic has determined the urgency of the topic, research objectives, research objects and scope, research hypotheses, research tasks, and methods. The research on the topic has systematized the theoretical basis for the concept and manifestation of social-emotional skills in student learning: generalizing the picture of the current situation of recognizing the importance of social-emotional skills in student learning, the level of assessment of the manifestation and educational measures of social-emotional skills in learning, and finding out the factors that affect social emotions in student learning such as from the external environment, at school, family and external social relationships. Factors from the internal environment are the self-awareness of each student. From the current situation of the problem, the study has proposed educational measures for 504 students from 8 schools and colleges in Can Tho University (CTU), Vietnam. Some measures were to educate social-emotional skills for students through soft skills topics, teach soft skills to students through extracurricular activities, and soft skills education for students through integrated teaching.  Article visualizations

Consequences of infertility in developing countries: results of a questionnaire and interview survey in the South of Vietnam

BACKGROUND: This study explores the psychological, socio-cultural and economic consequences of infertility on couples' life. The purpose of this research is to improve knowledge about the potentially serious implications of infertility in the South of Vietnam. METHODS: This study included 118 infertile couples who filled in questionnaires and 28 men and women who were interviewed. RESULTS: Data of the questionnaire show men and women do not differ in their responses and attitudes towards infertility. Almost one-third of the participants require psychological support. Interviewees experience secrecy, social pressure and economic hardship. CONCLUSION: Offspring are very important to Vietnamese couples. Their future depends on children. Family plays an important role in the experiences of the infertile couple. Economic consequences are a particular distressing factor. There is a need for psychological counselling in the treatment of infertile couples in the South of Vietnam. It should be realised that in developing countries, despite overpopulation, unwanted childlessness is an important social and economical burden that needs attention

Applying convolutional neural networks for limited-memory application

Currently, convolutional neural networks (CNN) are considered as the most effective tool in image diagnosis and processing techniques. In this paper, we studied and applied the modified SSDLite_MobileNetV2 and proposed a solution to always maintain the boundary of the total memory capacity in the following robust bound and applied on the bridge navigational watch & alarm system (BNWAS). The hardware was designed based on raspberry Pi-3, an embedded single board computer with CPU smartphone level, limited RAM without CUDA GPU. Experimental results showed that the deep learning model on an embedded single board computer brings us high effectiveness in application