1,720,970 research outputs found
Numerical simulation of a cooling platform in the biomaterial 3d printing process
Get PDFV diplomskem delu je v programskem okolju Ansys obravnavan numerični model hladilnega sestava pri 3D tiskanju biološkega materiala. Izvedli smo tokovno-toplotno analizo sistema in rezultate primerjali z eksperimentalno dobljenimi vrednostmi. Dodani so tudi potrebni preračuni za pravilno postavitev robnih pogojev. Rezultati simulacije so pokazali ustrezno ohlajanje celotnega sestava. Odstopanja rezultatov smo razložili, predstavili smo tudi pomanjkljivosti in možne izboljšave.This diploma thesis deals with a numerical model for the cooling platform during 3D printing of biomaterial. Numerical simulation was performed in Ansys software. We performed a flow-thermal analysis of the system and compared the results with the experimentally obtained data. The necessary calculations for the correct setting of the boundary conditions have also been added. The simulation results showed adequate cooling of the whole cooling platform. We explained the discrepancies in the results, we also presented the shortcomings and possible improvements
Determination of process parameters for tablet film coating using perforated drum coater
Get PDFSodobni proizvodni procesi zdravilnih učinkovin v svojem postopku uporabljajo tehnologijo oblaganja s perforiranimi bobni. Pomembno je določiti pravilne procesne parametre za čim bolj učinkovito nanašanje obloge in s tem izdelavo enakomerno obloženih tablet. V prvem delu diplomske naloge bom pojasnil nekaj teoretičnih osnov za razumevanje procesa in opis različnih parametrov pomembnih za uspešno in kakovostno izdelavo tabletne obloge, v praktičnem delu pa je izveden preračun procesnih parametrov. Ugotovljeni so bili specifični procesni parametri za podane velikosti bobnov in vplivi spremembe procesnih parametrov na učinkovitost delovanja sistema. Zaključke praktičnega dela diplomske naloge smo podali na osnovi opravljenih matematičnih preračunov in analiz.Contemporary manufacturing processes of active ingredients use a technology of perforated pan system. It is important to determine the most suitable parameters for the process and thus enable the most effective coating and consequently production of evenly coated tablets. In the first part of my thesis I will explain some of the theory needed to understand the aforementioned process and parameters which are important for successful and quality production of tablet coating, and in practical part of the thesis a calculation of process parameters had been made.
Specific process parameters for given drum sizes and impact of changes in process parameters on system effectiveness were determined. Results of practical part of the thesis were derived from mathematical calculations and analyses
THE MODEL OF CONJUGATE HEAT AND MASS TRANSFER BETWEEN A PARTICLE AND A FLUID FLOW IN SPRAY DRYING BASED ON THE BOUNDARY ELEMENT METHOD
Get PDFSušenje vlažnih snovi je ena izmed najstarejših procesnih tehnik, ki se uporablja na mnogih industrijskih področjih. Pri sušenju obravnavamo zapletene fizikalne procese, ki obsegajo vezan večfazni prenos toplote, snovi in gibalne količine. Kadar obravnavamo sušenje delcev ki so porozni, moramo proces sušenja obravnavati v več stopnjah, saj delci poleg vlage na površini vsebujejo še vlago v notranjosti. V doktorski nalogi je obravnavan razvoj numeričnega modela za izračun sušenja poroznih delcev v toku sušilnega plina, pri čemer je reševanje problema izvedeno v sklopu Euler-Lagrange modela računalniške dinamike tekočin. Tako je za numerično rešitev dvofaznega prenosa toplote s premikajočo fazno mejo znotraj gibajočega se delca bil razvit numerični model na osnovi Metode robnih elementov. Razvit je bil tudi nov model za izračun povezave prenosa toplote in snovi znotraj delca s prenosom toplote in snovi v toku sušilnega plina, in sicer z nadgradnjo modela točkovnega izvora v Metodi robnih elementov za nestacionarni prevod toplote v model, ki upošteva tudi konvektivni prenos toplote in snovi v sušilnem plinu. Izvedeni testni primeri potrjujejo primernost razvitih numeričnih modelov za prostorski in časovni izračun sušenja delcev v toku sušilnega plina.Drying of porous particles is one of the oldest process technique which is used in different industrial applications. In drying processes, we consider complex physical processes which involve coupled multiphase heat, mass and momentum transfer. By the porous particle drying, drying process have to be treated in more stages because particles beside surface moisture includes moisture in his interior. After surface moisture removing, drying process moves in particles interior where heat transfer in particles interior has to be solved. Energy needed for drying process is supplied by hot drying gas.
Through the drying process heat and mass exchange between particles and drying gas occur which results in local change of drying gas conditions. One of the most important informations in particle drying process is a drying time. To get the accurate results all interactions (drying air to particle and particle to drying air) need to be considered. In present work the 3D-axisymmetrical model for heat transfer in the spherical porous particle and fully coupled model for heat and mass transfer between particles and drying gas on the base of Boundary Elements Method was developed. Particles in coupled model were modeled as points. Results represented in this work show that keeping of coupling between particles and drying gas is very important to provide the accurate results
Computational spray drying analysis of zeolite particles of different sizes
Get PDFV nalogi je obravnavano tristopenjsko sušenje zeolitnih poroznih delcev različnih velikosti. Kot osnova za nalogo je bilo vzeto doktorsko delo Gregorja Sagadina. V uvodu je bila narejena analiza obstoječega računalniškega programa in analiza dogajanja v primeru sušenja delcev različnih velikosti. Na osnovi dobljenih rezultatov je bil v nadaljevanju spremenjen numerični model druge stopnje sušenja, tako da omogoča spreminjanje števila vozlišč v računski mreži in časovno učinkovitejši preračun. Na koncu je bil izveden preračun sušenja za delce različnih velikosti. Na osnovi analize rezultatov je bilo ugotovljeno, da je preračun časovno učinkovitejši, primerjava rezultatov pa je pokazala uporabnost in fizikalno pravilnost spremenjenega numeričnega modela.Spray drying
Multiphase numerical model
Porous zeolite particle
Numerical metho
Sinthesis and analysis of the roof of the stadium with method of finite element
Get PDFInovativnost in sprejemanje inovacij je pogoj, da se družba razvija in ostaja konkurenčna. Pri tem ima vedno večjo vlogo računalniška tehnologija, katere razvoj je ravno v zadnjih petnajstih letih omogočil velik napredek na področju računalniško podprtega inženirstva. Računalniško podprto konstruiranje in računalniško inženirstvo z metodo končnih elementov sta dandanes praktično nepogrešljiva. V diplomskem delu bo predstavljena uporaba komercialnega mednarodno priznanega programa Abaqus/CAE, s katerim bodo narejene analize trdnosti statično obremenjene kovinske strehe stadiona s snežno obremenitvijo. Analize bodo opravljene na treh različnih konstrukcijah, ki bodo sestavljene iz konstrukcijskih elementov, katerih debeline sten bodo enake. Na koncu bo narejena SWOT analiza posamezne konstrukcije ter bodo podane rešitve oz. možnosti za izboljšavo posamezne konstrukcije.Innovation and acceptance of the innovation is a condition that the company develops and remains competitive. In this has an increasing role computer technology, which has in the last fifteen years enabled significant progress in the field of computer assisted engineering. Computer-aided desing and computer engineering, with finite element method, are nowadays practically indispensable. In diploma work will bbe presented the use of a commercial international acclaimed programme Abaqus/CAE, with whom will be made the analysis of the strenght of the static loaded metal roof of the stadium with a snow load. The analysis will be carried out on three different structures, which will be composed of structural elements, of wich the thickness of the walls will be the same. In the end there will be made a SWOT analysis of the each structure and it will be given the opportunites for improvement or resolution of the structure
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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