Iskanje po katalogu digitalne knjižnice

Opis: In the diploma thesis the flow pattern and conditions in the downcomer of a pressurized water nuclear reactor were simulated, to study coolant mixing inside the primary circuit. This was done using computational dynamics software Ansys CFX. The nuclear reactor in Krško (Slovenia) was used as a basis for the model. The downcomer geometry was simplied for a more feasible study. Three separate simulations were done: one with normal conditions, one with loss of coolant accident conditions and one with a modified geometry. The flow was then studied at different condition at the same levels using velocity contours. The results showed that the axial velocity profiles at the downcomer outlet are not completely uniform.
Ključne besede: Nuclear Power Plant, Pressurized Water Reactor, Downcomer, Flow simulation, Ansys CFX
Objavljeno: 13.10.2021; Ogledov: 39; Prenosov: 4
Celotno besedilo (2,49 MB)

Opis: The increasing demand for smaller, faster, and more efficient switch mode power supplies (SMPS) and energy converters has led to the development of new power MOSFET technologies, such as SiC (silicon carbide) power MOSFET transistors. Switching parameters, output voltages and currents and power consumption need to be measured accurately to assess different types of power electronics components more efficiently in today’s rapid implementation of new energy transfer and modulation technology. The need for improving switching circuits in power electronics and trying to use simple simulation circuits for designing PCBs to measure output values of said power electronics transistors is the basis of this thesis. Even though manufacturers of power electronics transistors provide data on drain-source voltages and currents, these are mostly measured for specific conditions regarding pulse duration, gate-source voltage, case temperature of the transistor etc., and as such do not provide information as to where the limits of the drain source voltages and currents for different measurement parameter values are. The goal of the thesis is to find a way to measure the limits of drain-source voltages and currents of power electronics transistors (in this case a SiC MOSFET transistor), and to see if a simple SPICE-model could be built for other power electronic transistors as well, based on the results of this thesis.
Ključne besede: SiC, MOSFET, transistor, simulation, PCB
Objavljeno: 02.06.2021; Ogledov: 151; Prenosov: 23
Celotno besedilo (4,35 MB)

Opis: V diplomski nalogi ergonomsko oblikovanje delovnega mesta na montažni liniji žarometov je predstavljena ergonomska analiza delovnega mesta na montažni liniji žarometov. V uvodu je predstavljeno podjetje, znanstvena veda ergonomija, ter njena načela. Opisani sta tudi ergonomski metodi OWAS in RULA, ter programski paket Tecnomatix Jack. Osrednji del diplomske naloge predstavlja predstavitev delovnega mesta, ki je predmet analize, ocena kontrole z vidika ergonomskih načel in opravljene ergonomske analize. Analize so opravljene ročno in računalniško z uporabo paketa Human simulation Jack. V zaključnem delu diplome so predstavljeni rezultati vseh analiz in predlogi izboljšav.
Ključne besede: ergonomija, Human simulation Jack, OWAS, RULA, ergonomske metode, ergonomska analiza
Objavljeno: 22.09.2020; Ogledov: 296; Prenosov: 75
Celotno besedilo (2,56 MB)

Opis: Perceptual researchers often argue that natural selection supports veridical perceptions, respectively those that accurately reflect the environment. They also claim that beings whose perceptions are truer are also more fit. This assumption was tested using standard tools of evolutionary game theory in a simple environment. The result was that more veridical perceptions are not necessarily more successful. In the majority of the parameter space, veridical perceptions are extinct in competition with simplified perceptions, based on adaptive behavior in a given environment. In the thesis, we build upon mentioned territorial games introduced by Mark, Marion, and Hoffman in 2010, and extend four of their territory perception and selection strategies with two novel ones that together constitute a model of technological readiness valley of death. Whenever utility of a resource is not monotonous in the amount of that resource, the technological valley of death emerges. While the development of the science behind these models is in its infancy, modeling and understanding the phenomenon may shed light on progress and related phenomena in society.
Ključne besede: evolution, perception, utility, Monte Carlo simulation, game theory
Objavljeno: 22.11.2019; Ogledov: 512; Prenosov: 74
Celotno besedilo (1,56 MB)

Opis: V diplomskem delu je ročno in s pomočjo programske opreme Human simulation Jack ocenjeno delovno mesto končne kontrole v podjetju KLS Ljubno, d. o. o. Bistvo dela sta ergonomska študija in optimizacija delovnega mesta. V uvodnem delu je predstavljeno podjetje, pomen ergonomije in obrazložitev, kako se bom lotil rešitve problema. V osrednjem delu je prikazana celotna analiza delovnega mesta in izsledki, ki so bili pridobljeni ročno ter z uporabo programske opreme. V zaključnem delu pa so predstavljeni optimizacija in predlogi za izboljšanje delovnega mesta, z največjim poudarkom na uvedbi kontrolne linije za končno kontrolo.
Ključne besede: ergonomija, optimizacija, Human simulation Jack, končna kontrola, OWAS, analiza ledvenega dela hrbtenice
Objavljeno: 17.09.2018; Ogledov: 667; Prenosov: 110
Celotno besedilo (3,51 MB)