Electric arc in the switchgear

Tato práce se zaměřuje na popis vzniku, vlastnosti a chování elektrického oblouku v elektrických přístrojích. Dále se zaměřuje na to, jakým způsobem vzniká elektrický oblouk a jaký má vliv na kontakty elektrického přístroje. Elektrický oblouk se dělí na elektrický oblouk napájený se stejnosměrným nebo střídavým elektrickým proudem. Zhášení elektrického oblouku napájeného stejnosměrným proudem je obtížnější než při napájení střídavým proudem, protože stejnosměrný proud neprochází nulovou hodnotou. Pro návrh zhášecí komory je důležité znát vlastnosti elektrického oblouku napájeného stejnosměrným a střídavým proudem. Chování statické V-A charakteristiky elektrického oblouku napájeného stejnosměrným proudem bylo stanoveno experimentálně pomocí rovnice Ayrtonové. Následně byla proměřena dynamická charakteristika elektrického oblouku napájený střídavým proudem s cílem proměřit mezní hodnoty vzniku oblouku a popsat četné vlivy působící na oblouk. Závěrem byla data zhodnocena a podány návrhy pro rozšíření měřených úloh a diagnostiky oblouku v laboratorních podmínkách.This thesis focuses on description of creation, properties and behavior of an electric arc in the switchgear. In addition, it focuses on description how an electric arc can be created and how it effects contacts in electrical switchgear. Electric arcs is divided into arc with DC or AC. Quenching of the electric arc supplied by DC is more difficult than in case of AC since the DC does not pass through zero value. For the design of quenching chamber it is important to know the characteristics of the electric arc under both conditions. The behavior of static V-A characteristic of the electric arc supplied by DC was determined with experimental measurements using the equation by Ayrton. Subsequently, measurement of the dynamic characteristics of the electric arc with AC were determined. And the limits values for the emergence of electric arc were measured of. Last, the results wereevaluated and expansion of measurement task was proposed. The numerous influences on the arc were described. In conclusion the thesis extends diagnostic of the arc under the laboratory conditions.

The University of Georgia STEM Initiative II Projects, Programs and Partnerships

No abstract is available

Increasing the Number of Undergraduates who Succeed in STEM at UGA

The University of Georgia has implemented several strategies focused on improving instruction and student achievement in STEM courses and assisting in the preparation and professional development of K-12 science and math teachers. Specific activities include a mini-grants program, learning communities, pre-service teacher recruitment, expanding Project FOCUS, and increasing faculty effort to improve instruction and student learning in the STEM disciplines

Math 1113 Precalculus Emporium: A Multi-Institutional Online Pre-Calculus Course

One stumbling block for students considering becoming a STEM major has been introductory math courses. A new, innovative precalculus course being developed and delivered by five USG institutions may provide a solution. MATH 1113e Precalculus Emporium combines lessons learned from the Math Emporium model pioneered at Virginia Tech with elements of MOOC delivery to create a highly interactive and support rich online course model. While the pilot debuted in January 2014 with students and faculty from five institutions, the larger vision is for the course to become available for all USG institutions in the near future

Peripheral and Central Nutrient Sensing Underlying Appetite Regulation

The precise regulation of fluid and energy homeostasis is essential for survival. It is well appreciated that ingestive behaviors are tightly regulated by both peripheral sensory inputs and central appetite signals. With recent neurogenetic technologies, considerable progress has been made in our understanding of basic taste qualities, the molecular and/or cellular basis of taste sensing, and the central circuits for thirst and hunger. In this review, we first highlight the functional similarities and differences between mammalian and invertebrate taste processing. We then discuss how central thirst and hunger signals interact with peripheral sensory signals to regulate ingestive behaviors. We finally indicate some of the directions for future research

Peripheral and Central Nutrient Sensing Underlying Appetite Regulation

The precise regulation of fluid and energy homeostasis is essential for survival. It is well appreciated that ingestive behaviors are tightly regulated by both peripheral sensory inputs and central appetite signals. With recent neurogenetic technologies, considerable progress has been made in our understanding of basic taste qualities, the molecular and/or cellular basis of taste sensing, and the central circuits for thirst and hunger. In this review, we first highlight the functional similarities and differences between mammalian and invertebrate taste processing. We then discuss how central thirst and hunger signals interact with peripheral sensory signals to regulate ingestive behaviors. We finally indicate some of the directions for future research

Categorization of Arc Welding Workplaces According to the UV Radiation Intensity

Import 02/11/2016Diplomová práce se zabývá problematikou bezpečnosti práce na svařovacích pracovištích v souvislosti s intenzitou ultrafialového záření. Je zde proveden záznam svařovacích parametrů a návrh rizikové kategorie pracovišť v závislosti na změřené intenzitě UV záření. V poslední části práce jsou navrhnuty možné alternativní osobní ochranné pracovní prostředky pro svářeče.The diploma thesis deals with the issue of work safety at welding workplaces in connection with the intensity of ultraviolet radiation. Welding parameters and suggested risk categories of workplaces depending on the measured intensity of ultraviolet radiation is monitored. There is suggested an alternative personal protective equipment for welders in the last part of the thesis.345 - Katedra mechanické technologievýborn

Mathematical graphics with the Asymptote program

summary:Tento článek je vytvořen na základě diplomové práce autora (Kutal, 2012). Popisuje tvorbu matematické grafiky s programem Asymptote. Cílem textu je, aby čtenář z pestrých příkladů pochopil základní myšlenky práce s programem a zároveň měl dostatek informací o pozadí těchto postupů. V první části jsou vysvětlena základní syntaktická pravidla, v dalších částech je pak podrobně popsána metodika práce ve 2D a 3D. V závěrečné části jsou rozebrány algoritmy, které v Asymptote převádějí rovinné útvary do 3D reprezentace.summary:The aim of this paper is to describe creating of mathematical graphics with the program Asymptote with emphasis on 3D graphics. The task of this text is to make learning of the program easier with various examples used, while at the same time providing a solid description of the background of techniques used. In the first part, the basic syntax rules are explained, then in following chapters the routines for 2D and 3D are described. In the last chapter, algorithms converting planar regions into 3D surfaces are explained

Solution of Transport Coal Dust in Limestone

Import 05/08/2014Bakalářská práce se zabývá problematikou dopravy paliva vápenické pece, konkrétně uhelného prachu do podniku Vápenka Vitošov s.r.o., jeho vyskladněním a uložením v místě spotřeby. První část bakalářské práce se zabývá obecnými pojmy, jako jsou racionalizace, logistika a doprava. V další části práce je analyzován a zhodnocen současný systém dopravy a skladování mletého uhlí v podniku Vápenka Vitošov s.r.o. Následuje návrh řešení jiného druhu dopravy mletého uhlí do podniku Vápenka Vitošov s.r.o. včetně kalkulace nákladů daného projektu. V závěru práce jsou zhodnoceny oba druhy doprav včetně návratnosti vložené investice (prostředků).This bachelor thesis deals with the issue of the coal dust transportation to the lime kiln in Vápenka Vitošov s.r.o. There are mentioned general terms such as rationalization, logistic and transportation in the first part of this thesis. The present method of the coal dust transportation and storing in Vápenka Vitošov s.r.o. is analyzed and evaluated in the next section. A description of an alternative method of the coal dust transportation in Vápenka Vitošov follows, including the transportation cost and calculation of the costs of this suggested project. Both methods of coal dust transportation are compared and assessed in the conclusion of this thesis, including the return on investment.345 - Katedra mechanické technologievýborn

STEM II Initiative-Updates from Participating Institutions (Part 2)

STEM II Initiative – Updates from Participating Institutions (Part 2) is made up of a series of “sampler sessions” so that interested individuals can get an overview but not comprehensive coverage. Dr. Pamela Gore will begin this session by discussing the STEM II Initiative at Georgia Perimeter College. Second, Dr. Dabney Dixon will talk about the STEM II Initiative at Georgia State University. Third, Dr. Charles Kutal will provide information concerning the STEM II Initiative at the University of Georgia. Fourth, Dr. Farooq Khan and Dr. Myrna Gantner will discuss what is happening with the STEM II Initiative at the University of West Georgia