Computational Thermodynamics and Kinetics in Materials Modelling and Simulations

Over the past two decades, Computational Thermodynamics and Kinetics have been tremendously contributed to materials modeling and simulations and the demands on quantitative conceptual design and processing of various advanced materials arisen from various industries and academic institutions involved in materials manufacturing, engineering and applications are still rapidly increasing

Экспериментальная установка для определения тепловых свойств методом Фогеля

Выпускная квалификационная работа состоит из 67 страниц, 14 рисунков, 17 таблиц и 23 источника. Ключевые слова: тепловые свойства, метод пластины, теплопроводность. Объектом исследования является экспериментальная лабораторная установка для исследования тепловых свойств плохих проводников. Целью проекта является исследование и сравнение методов определения тепловых свойств плохих проводников тепла. В процессе выполнения проекта были проанализированы исследования методов измерения плохих проводников тепла. Изготовлены образцы из материала с низким коэффициентом теплопроводности - ТЗМК – 10 (вспененный кварц). Спроектирована вакуумная камера с внутренним водяным охлаждением и размещённым в ней теплоизолированным образцом. Так же в процессе исследований были получены экспериментальные данные.Final qualifying work consists of 67 pages, 14 figures, 17 tables and 23 source. Key words: thermal properties, method plate conductivity. The object of the research is an experimental laboratory installation for study of thermal properties of poor conductors. The aim of the project is to study and compare methods for the determination of thermal properties of bad heat conductors. In the process of implementation of the project has been analyzed and research methods measurement poor conductors of heat. Samples made from a material with a low coefficient of thermal conductivity - TZMK – 10 (foamed quartz). Designed vacuum chamber with internal water cooling and placed on the insulated sample. Also in the research process was the data obtained. Considered the issues of fire, industrial and

Perceived connections between information and communication technology use and mental symptoms among young adults - a qualitative study

<p>Abstract</p> <p>Background</p> <p>Prospective associations have been found between high use of information and communication technology (ICT) and reported mental symptoms among young adult university students, but the causal mechanisms are unclear. Our aim was to explore possible explanations for associations between high ICT use and symptoms of depression, sleep disorders, and stress among young adults in order to propose a model of possible pathways to mental health effects that can be tested epidemiologically.</p> <p>Methods</p> <p>We conducted a qualitative interview study with 16 women and 16 men (21-28 years), recruited from a cohort of university students on the basis of reporting high computer (n = 28) or mobile phone (n = 20) use at baseline and reporting mental symptoms at the one-year follow-up. Semi-structured interviews were performed, with open-ended questions about possible connections between the use of computers and mobile phones, and stress, depression, and sleep disturbances. The interview data were analyzed with qualitative content analysis and summarized in a model.</p> <p>Results</p> <p>Central factors appearing to explain high quantitative ICT use were personal dependency, and demands for achievement and availability originating from the domains of work, study, social life, and individual aspirations. Consequences included mental overload, neglect of other activities and personal needs, time pressure, role conflicts, guilt feelings, social isolation, physical symptoms, worry about electromagnetic radiation, and economic problems. Qualitative aspects (destructive communication and information) were also reported, with consequences including vulnerability, misunderstandings, altered values, and feelings of inadequacy. User problems were a source of frustration. Altered ICT use as an effect of mental symptoms was reported, as well as possible positive effects of ICT on mental health.</p> <p>Conclusions</p> <p>The concepts and ideas of the young adults with high ICT use and mental symptoms generated a model of possible paths for associations between ICT exposure and mental symptoms. Demands for achievement and availability as well as personal dependency were major causes of high ICT exposure but also direct sources of stress and mental symptoms. The proposed model shows that factors in different domains may have an impact and should be considered in epidemiological and intervention studies.</p

On the nearest neighbour interaction model with a concentration dependent interaction energy

In order to apply to alloy systems with asymmetric thermodynamic properties, the nearest neighbor interaction model must have a concentration dependent interaction energy. At least one new parameter is then introduced which can be used to make experiment agree with theory. The three systems Au-Ni, Al-Zn and Al-Ag are examined on this basis. In the Al-Ag system the concentration dependence is very strong. As a consequence the phase diagram contains a metastable miscibility gap and a metastable ordering region which overlap each other. This may explain how two types of zones can form during age-hardening in this system.Pour pouvoir être appliqué aux systèmes alliages possédant des propriétés thermodynamiques assymétriques, le modèle d'interaction des plus proches voisins doit avoir une énergie d'interaction dépendant de la concentration. On introduit alors au moins un nouveau paramètre qui peut être utilise pour réaliser l'accord entre l'expérience et la théorie. Les trois systèmes Au-Ni, Al-Zn, et Al-Ag sont examinés sur cette base. Dans le système Al-Ag, l'influence de la concentration est très forte. Une conséquence est que le diagramme de phase contient une région de miscibilité métastable et une région d'ordre métastable qui s'interpénètrent. Ceci peut expliquer comment deux types de zones peuvent se former pendant le durcissement par vieillissement dans ce système