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Articular cartilage has a low propensity for self-repair, due to which 27 million people are affected by osteoarthritis every year in North America. The current repair techniques used for cartilage defects possess flaws that reduce long-term clinical success. Tissue engineering carries with it the promise of engineering hyaline-like cartilage with physical and biochemical properties, similar to that of native cartilage. This being said, the primary objective of my project was to engineer clinically relevant sized articular cartilage constructs. To achieve my objective, first, I investigated the effect of continuous culture on cartilaginous tissue growth. Constructs grown under continuous media flow significantly accumulated more collagen and glycosaminoglycan, and displayed a stratified morphology, similar to that found in native cartilage. The second goal was to further increase chondrocyte proliferation, and extracellular matrix (ECM) accumulation. To achieve this, constructs were grown in a bioreactor with media supplemented with 14 mM sodium bicarbonate (NaHCO3). Constructs cultivated in the bioreactor with NaHCO3 supplementation exhibited a significant (p<0.05) increase in ECM accumulation (a 98-fold increase in glycosaminoglycans and a 25-fold increase in collagen content), cell proliferation (a 13-fold increase), and thickness (a 28-fold increase) compared to all other conditions (static and reactor without NaHCO3 supplementation). The third goal was to engineer cartilage constructs with as little cells as possible, reducing donor site morbidity. From the results obtained, it was evident that the monolayer constructs outperformed all the other constructs (pellet, biopsy, and minced). The final goal was to understand the underlying reason for the increased proliferation. First, I investigated if there were any differences present in intracellular pH (pHi) and intracellular buffering capacity. Second, I determined the role of extracellular pH (pHe) on cell proliferation. In an effort to accurately achieve this, I, for the first time, have reported on measuring pHi of chondrocytes while still in culture (2D and 3D cultures) using a confocal microscope. This study demonstrated the importance of extracellular environments, such as pHe, extracellular buffering capacity, and the presence of carbon dioxide and bicarbonate ions for chondrocyte proliferation. / Thesis (Ph.D, Chemical Engineering) -- Queen's University, 2012-10-30 19:19:32.026

Made available in DSpace on 2015-03-26T12:27:19Z (GMT). No. of bitstreams: 1 texto completo.pdf: 778013 bytes, checksum: 80573b20b6b26ae5c6d224941a486c2d (MD5) Previous issue date: 2014-06-04 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / This study aimed to investigate different types of materials for the production of compressed biofuel. The selected materials were: tree pruning waste, corrugated cardboard, cartons and sludge of water treatment obtained by flotation technique; these materials were chosen because of its abundance in the urban environment, the ease of finding them in urban areas and also the few studies related to them. The studywas divided into three chapters: in chapter I, was determinedthe physical, chemical and thermal characteristics of the residuesto give support for the subsequent chapters. In chapter II briquettes composed of mixtures of these residues were produced, using the urban pruning residues as the basis for the different blends, mainly because of its lignocellulosic composition; chemical and physical analysis were also made in the briquettes to analyze if the compactation process of the mixtures was effective and if the final product has favorable characteristics for energy use. In chapter III was described the production and evaluation of pellets composed by municipal solid waste, and similarly, we used the urban pruning residues as the main material for the blends with the other materials. After all analysis, it was observed that the urban pruning residues, the corrugated cardboard andthe aseptic cartons showed positivecharacteristics for use as biofuel, but the flotation sludge showed aninorganic character, presenting a low calorific value and high ash content. Nevertheless, the sludge was used for the production of briquettes and pellets in order to evaluate possible mixtures to minimize those problems. Even for the briquettes or for the pellets it was observed that the addition of sludge in the composition provided increases in the strength and density, but reduced the calorific value and increased the ash content. The incorporation of cardboard or carton caused an increase in density and strength and a small reduction in calorific value. It could be concluded that the municipal solid residues used in this researchhad characteristic to use them to produce compressed fuelsas asustainable alternative for energy production. Regards about the mixing ratios of the residues should be taken to optimize the overall process. / Este estudo teve por objetivo pesquisardiversos tipos deresíduos sólidos urbanos para a produção de combustíveis compactados. Foram selecionados resíduos de poda de árvores, papelão ondulado, embalagens cartonadas e lodo de tratamento de águas pela técnica de flotação. Optou-se por estes materiais devido a sua representatividade no ambiente urbano, pela facilidade em encontra-los e também por haver poucos estudos relacionados a eles. O trabalho foi dividido em três etapas, inicialmente, foram determinadas as características físicas, químicas e térmicas dos resíduos como forma de embasamento para os próximos capítulos. Na sequencia foram produzidos briquetes compostos por diferentes proporções destes resíduos, usando como base para as misturas os resíduos de podade árvores devido sua composição lignocelulósica; também foram feitas análises químicas e físicas nos briquetes para avaliar se o processo de compactação das misturas foi eficiente e se o produto final apresentou características energéticas favoráveis ao uso. Finalmente, avaliou-sea produção de pellets produzidos com os resíduos sólidos urbanos, e da mesma forma, utilizaram-se os resíduos de poda urbana como base para as misturas com os outros materiais. Após as análises observou- se que, os resíduos de poda urbana, papelão ondulado e embalagens cartonadas apresentaram características favoráveis para o uso como biocombustível, porém o lodo de flotação apresentou caráter inorgânico, com baixo poder calorífico e alto teor de cinzas. Apesar disso, o lodo foi utilizado para a produção dos briquetes e pellets com o intuito de avaliar possíveis misturas que minimizem estes problemas. Tanto para os briquetes quanto para os pellets, observou-se que a adição de lodo na composição destes materiais proporcionou incrementos na resistência e densidade, porém reduziu o poder calorífico a aumentou o teor de cinzas. A incorporação de papelão ou embalagens cartonadas ocasionou aumento na densidade e na resistência e uma pequena redução no poder calorífico. Conclui-se que os resíduos sólidos urbanos utilizados neste estudo apresentaram potencial para produção de combustíveis compactados, tornando-se uma alternativa sustentável para produção de energia, desde que otimizadas as proporções das misturas de materiais.

L'amélioration de la dissolution des médicaments peu solubles présente de nombreux défis.Dans cette thèse, un procédé d'extrusion-sphéronisation a été étudié en profondeur pour améliorer la dissolubilité du médicament avec une formulation de nano-émulsion. Le but du travail de thèse est de décrire les propriétés et les procédés de fabrication de minigranules permettant d'augmenter la solubilité des principes actifs peu solubles dans l'eau et donc d‘améliorer leur biodisponibilité lors de l'administration par voie orale, pour deux modèles de molécules différentes qui sont l‘acide folique (vitamine peu soluble dans l'eau) et le kétoprofène (anti-inflammatoire non stéroïdien qui présente une solubilité limitée dans les fluides gastriques à cause de son pKa (classe II dans le système de classification biopharmaceutique – BCS, ayant une action anti-inflammatoire, antalgique et antipyrétique). Cette étude décrit la préparation par extrusion-sphéronisation, caractérisation et étude de dissolution in vitro d'acide folique et de pastilles de kétoprofène revêtues de Acryl-EZE®, Advantia® Performance dans un minicoatère à lit fluidisé. Les résultats des essais ont montré la faisabilité de la préparation de pastilles enrobées entériques contenant un AINS et que, en revêtant le système multiparticulaire avec Acryl-EZE® 93A92545 et Advantia® Performance190024HA49 à un gain pondéral de 17,5%, 12,0%, respectivement, du médicament à partir des pastilles peuvent être obtenus. Les résultats des essais de dissolution ont indiqué que dans un milieu acide, le revêtement de film a entraîné un retard dans la libération du médicament, alors qu'aucun retard n'a été observé dans un milieu tampon à pH 6,8. / Improvement in dissolution of poorly soluble drugs has many challenges.In this thesis, an extrusion-spheronization process was thoroughly studied forimproving dissolubility of drug with nano-emulsion formulation.The aim of the thesis work is to describe the properties and manufacturing processes ofpellets to increase the solubility of poorly soluble active ingredients in water and thus improvetheir bioavailability when administered orally: folic acid (water-insoluble vitamin) andketoprofen (Non-steroidal anti-inflammatory, having anti-inflammatory, analgesic andantipyretic action, class II in the Biopharmaceutical Classification System).This study describes the preparation by extrusion-spheronization, characterisation andin vitro dissolution study of folic acid and ketoprofen pellets. Ketoprofen pellets coated withAcryl-EZE®, Advantia® Performance in a fluid-bed minicoater. The results of the tests showedthe feasibility of the preparation of enteric-coated pellets containing a NSAID and that bycoating the multiparticulate system with either 17.5% Acryl-EZE® 93A92545 or with 12%Advantia® Performance 190024HA49 weight gain, an enteric release of the drug from thepellets can be obtained. The results of dissolution testing indicated that in acidic media, entericfilm coating resulted in a delay in the release of the drug, while no delay was observed in pH6.8 buffer media.

<p>U savremenom uzgoju živine i svinja sme&scaron;e se retko koriste u pra&scaron;kastom obliku<br />već se uglavnom peletiraju nakon ume&scaron;avanja pojedinačnih sastojaka. Pri<br />peletiranju dolazi do naru&scaron;avanja granulacije sme&scaron;e, odnosno do gotovo<br />potpunog eliminisanja krupnih čestica, kao i do nastajanja velike količine najsitnijih čestica. U okviru istraživanja u ovoj doktorskoj disertaciji ispitivan je uticaj promene odabranih parametara mlevenja i peletiranja na granulaciju čestica od kojih su pelete sačinjene. Cilj je bio da se utvrdi kombinacija parametara koja doprinosi povećanju sadržaja krupnih čestica, &scaron;to je značajno u ishrani živine, odnosno da se utvrdi kombinacija parametara koja će u &scaron;to većoj meri uvećati sadržaj čestica srednje veličine i umanjiti udeo najsitnijih čestica, &scaron;to je značajno u ishrani svinja. Pri tome je određivan i kvalitet peleta, koji ne sme biti značajnije naru&scaron;en, kao i potro&scaron;nja energije pelet prese za koju je poželjno da je &scaron;to niža.<br />Nezavisni parametri peletiranja bili su granulacija kukuruznog mliva, rastojanje (zazor) između valjaka i matrice pelet prese, debljina matrice pelet prese i sadržaj vode materijala koji se vodi na peletiranje. Istraživanje je podeljeno u dve faze, gde je u prvoj za usitnjavanje primenjen mlin čekićar, a u drugoj mlin sa valjcima. Na oba uređaja prizvedene su po tri granulacije mliva, pri čemu se granulacija ukrupnjava od najsitnijeg mliva dobijenog na mlinu čekićaru do najkrupnijeg mliva dobijenog na mlinu sa valjcima. U prvoj fazi tri granulacije mliva dobijene na mlinu čekićaru su peletirane u kombinaciji sa tri zazora valjci-matrica (0,30; 1,15 i 2,00 mm) i tri sadržaja vode materijala (14,5%, 16,0% i 17,5%), a u drugoj fazi tri granulacije mliva dobijene na mlinu sa valjcima peletirane su u kombinaciji sa tri debljine matrice (24, 30 i 36 mm) i tri sadržaja vode materijala (14,5%, 16,0% i 17,5%). Dakle, u obe faze su varirana tri parametra na tri nivoa pri čemu je primenjen Box-Behnken eksperimentalni dizajn. Zavisno promenljive karakteristike (odzivi) bili su temperatura matrice pelet prese, specifična potro&scaron;nja energije pelet prese, udeo pra&scaron;ine u peletama, stepen želatinizacije skroba, tvrdoća, stepen otiranja i nasipna masa peleta, kao i granulacija materijala nakon peletiranja. Za svaki od pomenutih odziva definisan je polinom (model) drugog reda. Dobijeni modeli upotrebljeni su za optimizaciju procesa peletiranja sa ciljem da se postigne željena granulacija peletiranog materijala, uz &scaron;to bolji kvalitet peleta i uz &scaron;to manju potro&scaron;nju energije.<br />U istraživanju je utvrđeno da mliva sa približno istom vredno&scaron;ću geometrijskog srednjeg prečnika, dobijena na mlinu čekićaru i mlinu sa valjcima, imaju značajno različitu raspodelu veličine čestica. Na mlinu čekićaru dobija se &scaron;ira raspodela, sa većim sadržajem najkrupnijih i najsitnijih čestica, u poređenju sa mlinom<br />sa valjcima. Za proizvodnju mliva približno istog geometrijskog srednjeg prečnika, a pogotovo mliva sa relativno sličnom raspodelom veličine čestica,<br />potro&scaron;nja energije kod mlina sa valjcima značajno je manja u poređenju sa mlinom<br />čekićarom. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; Potvrđeno je da peletiranje uzrokuje veliki intenzitet usitnjavanja čestica bez obzira na primenjene parametre. Međutim, određene kombinacije parametara mogu doprineti značajnijem očuvanju krupnih čestica. Parametar peletiranja koji najvi&scaron;e doprinosi<br />povećanju udela krupnih čestica u peletama je granulacija mliva koje se upućuje na<br />peletiranje. &Scaron;to je krupnija granulacija, udeo krupnih čestica u peletama će biti veći.<br />Rezultati optimizacije procesa peletiranja u prvoj fazi ukazuju da je u pogledu proizvodnje peletirane hrane za živinu, kada je poželjno očuvanje određene količine krupnih čestica, potrebno primeniti krupno mlevenje na mlinu čekićaru, uz<br />pode&scaron;avanje zazora između valjaka i matrice od 2 mm i uz sadržaj vode materijala od 17,5%. U drugoj fazi optimizacijom je utvrđeno da je potrebno koristiti debljinu matrice od 30 mm, najkrupniju granulaciju mliva na mlinu sa valjcima i vlagu od 17,5%. Pri proizvodnji peletirane hrane za živnu povoljnije je koristiti mlin čekićar, s obzirom da je utvrđeno da su čestice mliva dobijenog na čekićaru otpornije na usitnjavanje tokom peletiranja od čestica dobijenih na mlinu sa valjcima &scaron;to omogućuje očuvanje većeg broja krupnih čestica tokom peletiranja. Povećanje &scaron;irine zazora valjci-matrica nije poželjno prilikom peletiranja hrane za svinje jer se povećava intenzitet usitnjavanja čestica, a time i udeo najsitnije frakcije čestica. Sličano je i sa povećanjem debljine matrice. U prvoj fazi istraživanja, rezultati optimizacije pokazuju da je u cilju povećanja udela frakcija čestica srednje veličine (630 &ndash; 1600 &mu;m), kao i smanjenja sadržaja najsitnijih čestica (&lt; 125 &mu;m), potrebno primeniti najsitnije mlevenje na mlinu čekićaru, najveći sadržaj vode materijala (17,5%), dok zazor između valjaka i matrice treba podestiti da bude ne&scaron;to veći od 0,30 mm. I u drugoj fazi istraživanja optimizacija je ukazala da je najveći udeo čestica srednje veličine (630 &ndash;<br />1600 &mu;m), kao i najmanji udeo čestica &lt; 125 &mu;m, ostvaren pri peletiranju najsitnijeg<br />mliva dobijenog na mlinu sa valjcima. Pri tome sadržaj vode je potrebno podesiti na<br />17,5%, dok debljina matrice treba biti oko 28 mm.<br />Pri predloženim optimalnim parametrima peletiranja ostvaren je zadovoljavajući<br />kvalitet peleta, a potro&scaron;nja energije pelet prese bila je na prihvatljivom nivou.</p> / <p>In modern poultry and swine breeding, animal feed is rarely used in powder form but mainly pelleted after mixing of different ingredients. During pelleting process, granulation of the feed is compromised, i.e. coarse particles are<br />almost completely destroyed and the content of fine particles is strongly<br />increased. This doctoral thesis investigated the impact of changes in selected grinding and pelleting parameters on granulation of particles after pelleting. The goal was to achieve the quantity of coarse particles in pellets to be as high as possible, which is important in poultry nutrition. Another goal was to determine the combination of parameters that will increase, as much as possible, the content of particles medium in size and reduce the share of the smallest particles, which is important in swine nutrition. At the same time quality of the pellets must not be significantly degraded and energy consumption of pellet press should be as low as possible.<br />Independent pelleting parameters were corn granulation after grinding, the distance (gap) between the rollers and the die of pellet presses (roller-die gap), the thickness<br />of the pellet press die (die thickness) and the water content of pelleted material. The study was divided in two stages. In the first stage the corn was ground using a hammer mill and in the second stage, roller mill was used. Three different granulations were produced on both mills. Coarseness of the ground material increased from the finest material produced using the hammer mill to the coarsest material obtained at the roller mill. In the first stage, three different granulations produced at the hammer mill were pelleted in combination with three different roller-die gaps (0.30, 1.15 and 2.00 mm) and three different water contents of material (14.5%, 16.0% and 17.5%). In the second stage three different granulations produced at the roller mill were pelleted in combination with three different die thicknesses (24, 30 and 36 mm) and three different water content of material (14.5%, 16.0% and 17.5%). Thus, three parameters were varied at three levels in both stages and experiments were designed according to Box-Behnken design. Depended variables (responses) were: temperature of the pellet press die, specific energy consumption of pellet press, dust content in pellets, degree of starch gelatinization,&nbsp; particle size of the material after pelleting. For each of the responses, a second order polynomial model was defined and used for optimization of the pelleting process. It was determined that particle size distribution of material with similar geometric mean diameter, obtained with hammer mill and roller mill, is significantly different from each other. Hammer mill produced higher quantity of the coarsest and the finest particles comparing to roller mill. Energy consumption of roller mill for grinding to similar particle size distribution or similar geometric mean diameter is lower compared to hammer mill. Even though it was determined that secondary grinding of particles during pelleting is inevitable, certain combinations of pelleting parameters may contribute to significant preservation of large particles and to reduction of quantity of small particles. Results of optimization in the first stage indicated that for the production of pelleted poultry feed, when certain amount of coarse particles should be preserved, it is necessary to apply coarse grinding on hammer mill, with the roller-die gap of 2 mm and with material water content of 17.5%. In the second stage it was determined that it is necessary to use die with thickness of 30 mm, coarsest granulation at the roller mill and material water content of 17.5%. In the production of pelleted poultry feed it is better to use a hammer mill since it was found that the particles obtained on hammer mill are more resistant to secondary grinding than the particles obtained with the roller mill. Roller-die gap increase is not desirable during pelleting of swine feed because it increases secondary grinding, and thus the proportion of the smallest particles. Similar effect has an increase of the die thickness. In the first stage of the study, the results of the optimization showed that the largest quantity of medium-sized particles (630 &ndash; 1600 &mu;m), and the lowest quantity of the smallest particles (&lt; 125 &mu;m), were achieved with the finest grinding on the hammer mill. At the same time water content of 17.5% should be applied, while the roller-die gap should be close to 0.30 mm. In the second stage of the study, the largest quantity of medium-sized particles, and the lowest quantity of the smallest<br />particles, was achieved with the finest grinding on the roller mill. According to the optimization results, the water content should be set to 17.5%, while die thickness should approx. 28 mm. With the proposed optimal parameters, satisfactory pellet quality was achieved, and energy consumption of the pellet<br />presses was at an acceptable level.</p>

Inom EU finns mål på att sänka utsläppen med 40% till år 2030. I Sverige står bygg och fastighetssektorn för cirka 21% av Sveriges totala utsläpp. För att lyckas nå EU:s klimatmål måste en konvertering till förnybara uppvärmningskällor ske. Region Gotland ansvarar idag för över 500 000m2 fastigheter. Många använder idag pellets till uppvärmning. Pellets ses som klimatneutralt och släpper därför inte ut mer koldioxid än vad trädet plockat upp. Ett problem som uppstår då pelletspannorna kräver underhåll och leveranser. Flera av Region Gotlands fastigheter ligger flera mil iväg från både leverantör och underhållspersonal vilket ökar kostnader och miljöpåverkan än mer. En av dessa fastigheter, brandstationen i Öja, ligger till grund för denna studie. Då det finns flera fastigheter med liknande förutsättningar kan rapporten användas som underlag för dessa. Studien undersöker ifall en konvertering från pelletspannan till en värmepump kan sänka kostnaderna och bidra till lägre utsläpp. Vid en konvertering till värmepump sänks systemtemperaturerna från 80/60 till 55/45 vilket kan skapa problem för befintliga radiatorer, rör och pumpar. Radiatorernas och rörens kompatibilitet med nya temperaturerna under söks därför i studien men pumpar utelämnas för en framtida studie. Med hjälp av transmissionsberäkningar och en formel baserad på grad dagar och tidigare energiförbrukning beräknades ett värmebehov för fastigheten på 23,8 kW den kallaste dagen på året. Med detta kunde tre värmepumplösningar tas fram. Samtliga lösningar innefattar även en ny ackumulatortank då den nuvarande är över 40 år gammal och har ett flertal brister. Med optimering av uppvärmningssystemet genom att sänka temperaturen i de fläktvärmda rummen till 15 grader kan värmebehovet sänkas med 4kW. En undersökning gällande installation av solfångare har även gjorts, där det inte visade sig lönsamt med dagens tappvarmvattenbehov.  Efter de dimensioneringar som gjorts framkommer även att två rörslingor behöver bytas, men att ett eventuellt radiatorbyte lämnas till efter en konvertering för att se om dessa behöver bytas. Undersökningarna visar även att de befintliga fläktvärmarna är överdimensionerade och inte behöver bytas. Utsläppsberäkningar visar att utsläppen kan minskas med 2565 kg CO2 eq per år vid en eventuell konvertering. Payoffmetoden har använts för att visa att de tre lösningarna har en mycket kort återbetalningstid mellan 3,9 år för luft/vattenvärmepumpar från CTC till 4,7 år för Thermias bergvärmelösning. Med hjälp av LCC kalkyler har lösningarna livstidskostnad tagits fram. Ställt mot den be fintliga pelletspannan uppgår besparingen till 879 000kr för Thermias lösning – 966 000kr för CTC:s lösning med en kalkylränta på 1,5%. Slutsatsen är därför att en konvertering till värmepump bör ske för att spara både ekonomiskt men även för att minska utsläppen. / One of EU’s climate goals is to reduce the greenhouse gas emissions by 40% by the year of 2030. In Sweden the “building and real estate sector” stands for 21% of Sweden’s total pollution of greenhouse gas emissions. To reach EU’s goals by 2030 there must be a transformation to renewable sources for use in the heating of real estates. Region Gotland manages over 500 000 m2 of estates. Many of which uses pellet as the source of heating. This heating alternative requires regular deliveries of material and maintenance. Many of the estates in the care of Region Gotland are far away from both the supplier and maintenance team which creates great transport costs and gas emissions. The fire sta- tion in “Öja” is one of them and is the one used in this study. As there are many similar buildings the results here can be used as a foundation for those estates. This study is exploring if a conversion from pellet to a heating pump can lower the expenses and greenhouse gas emissions. By changing to a heat- ing pump from a pellet boiler the temperatures are reduced from 80/60°C to 55/45 °C in the system. This may cause problem with radiators, pumps and pipes. Because of this, radiators and pipes will also be inves- tigated, but pumps will be left out for another study. The heat needed to increase the temperature in the building to 21 °C at a DVUT of -8,7 °C was calculated using transmission losses calculations and a formula based on “graddagar” and earlier energy uses by the estate, to 23,8 kW. Based on the calculated heat, three heating pump solutions were created, all of whom included a new water heater with storage tank. The old storage tank is over 40 years by age and therefore has many short- comings. Using calculations to optimize the heat usage, the heat needed can be re- duced by 4kW at DVUT by lowering the temperature to 15 °C in the fan heated area of the building while still being within the laws of the Swe- dish work environment authority. An investigation was made to see if solar collectors could be used to heat the domestic hot water in the estate. The results showed that in this case it wouldn’t be economically justifiable due to low energy cost with a new heating pump. The calculations done for pipes and radiators showed that two pipes must be replaced but that the radiators are mostly fine with the new tempera- tures. A replacement of the radiators should be left till after the conver- sion. Calculations on the fan heaters showed that there is no need to re- place these. Calculations on greenhouse gas emissions showed that the emissions can be reduce by 2565 kg CO CO2-eq each year if the pellet boiler is replaced by a heating pump. The Pay-off method and LCC calculations was used to show the profita- bility in the three heating pump solutions. The Pay-off time for the solu- tions ranged from CTC’s air to water heating pumps at 3,9 years to 4,7 years for Thermia’s geothermal heating pump. The LCC calculations showed that changing to a heat pump could generate a saving of 879 000 SEK for Thermia’s solution to 966 000 SEK for CTC’s solution. The conclusion is therefore that the pellet boiler should be changed to a heating pump to save money and reduce the greenhouse gas emissions.

Les crayons combustibles au sein des Réacteurs à Eau Pressurisée (REP) sont constitués de pastilles de céramique (UO2 ou (U-Pu)O2) empilées dans des gaines en alliage de zirconium, le Zircaloy. Avant l'irradiation, il existe un jeu de fabrication entre les pastilles et la gaine de l'ordre d'une centaine de microns. Au cours de l'irradiation, ce jeu est rapidement réduit ou totalement rattrapé du fait des différentes déformations que subissent les pastilles et la gaine. La connaissance de la nature de ce contact pastille-gaine à chaud, nécessaire pour comprendre les phénomènes et valider les modélisations de l'évolution de l'état de l’interface en fonction du taux de combustion, est accessible aujourd’hui exclusivement à partir de mesures destructives effectuées en laboratoire de haute activité, après retour à froid des combustibles. Pour obtenir un plus grand nombre d’informations sur des zones d’intérêt étendues, ou sur un tronçon de crayon avant refabrication pour ré-irradiation en réacteur expérimental, un moyen de caractérisation non destructif de l’interface pastille-gaine est nécessaire. C'est dans ce contexte que l'Institut d'Electronique et des Systèmes UMR CNRS 5214 de l'Université de Montpellier développe, dans le cadre d'une collaboration avec le Commissariat à l'Energie Atomique et aux Energies Alternatives, et en partenariat avec EDF et Framatome, un microscope acoustique adapté aux géométries cylindriques. Le travail mené au cours de cette thèse inclut la conception et l’adaptation d’une tête de mesure sur un banc prototype et la démonstration de la faisabilité de l’acquisition d’images haute résolution (quelques dizaines de microns) sur tubes de gaine, l’enjeu étant de conserver la focalisation sur l’ensemble des zones imagées sur un même tube de diamètre externe de l’ordre de 10 mm et de longueur de 100 à 500 mm. La difficulté à reproduire les conditions de contact pastille-gaine en laboratoire ont orienté le choix des échantillons simulants, élaborés à partir de tubes de gaine avec ou sans zircone et chargés localement de colle. Les acquisitions réalisées sur ces échantillons simulants montrent la capacité de la méthode à détecter les changements de structure de la surface interne de la gaine. La mesure est ainsi sensible à la présence d’une couche de zircone interne d’épaisseur de 10 $mu$m, et à la présence de matériau adhérent à l’intérieur du tube. Ces résultats montrent l’intérêt de poursuivre ces études, pour améliorer grâce à du traitement du signal l’interprétation des images avec pour objectif final l’adaptation de la méthode et sa qualification sur un banc sur crayon irradié. / Pressurized Water Reactor (PWR) fuel rods are made of ceramic pellets (UO2,(U,Pu)O2 or gadolinium fuel) assembled in a zirconium alloy cladding tube. By design, an initial gap, filled with helium, exists between these two elements. However during irradiation this gap decreases gradually, on the one hand, owing to a variation in cladding diameter, due to creepdown caused by pressure from the coolant, and, on the other hand, increased pellet diameter, due to thermal expansion, and swelling. In hot conditions, during the second or third cycle of irradiation, the pellet/cladding gap is closed. However, during the return to cooler conditions, the gap can reopen. At a high burnup (generally beyond the 3rd cycle of irradiation) an inner zirconia layer of the order of 10 to 15 $mu$m is developed by oxidation leading to a chemical bonding between the pellet and the cladding. This bonding layer may contribute to a non-reopening of the pellet-cladding gap.Currently, only destructive examinations, after cutting fuel rods, allow the visualization of this area, however, they require a preliminary preparation of the samples in a hot cell. This limits the number of tests and measurements on the fuel rods. In this context, the Institute of Electronic and Systems of Montpellier University (IES - UMR CNRS 5214), in collaboration with the Alternative Energies and Atomic Energy Commission (CEA), Electricité de France (EDF) and Framatome, is developing a high frequency acoustic microscope adapted to the control and imaging of the pellet/cladding interface by taking into account the complexity of the structure's cladding which has a tubular form. Because the geometrical, chemical and mechanical nature of the contact interface is neither axially nor radially homogeneous, the ultrasonic system must allow the acquisition of 2D images of this interface by means of controlled displacements of the sample rod along both its axis and its circumference. The final objective of the designed acoustic microscope is to be introduced in hot cells.

<p>Suncokretova sačma ima manju zastupljenost u peletiranim sme&scaron;ama za<br />ishranu životinja od sojine sačme zbog većeg udela sirovih vlakana. Sirova<br />vlakna depresivno deluju na svarljivost obroka i proizvodne rezultate, a mogu<br />da imaju negativan uticaj na fizički kvalitet peleta. Pri peletiranju sme&scaron;a za<br />ishranu životinja u poslednje vreme značajna pažnja se posvećuje<br />funkcionalnim promenama makronutrijenata, jer se smatra da ove promene<br />pozitivno utiču na fizički kvalitet peleta. Razvojem modernih analitičkih tehnika,<br />posebno termalne analize, moguće je opisati promene na skrobu u procesu<br />peletiranja, nastale usled uticaja toplote i vlage. Sa druge strane, promene na<br />proteinskoj komponenti u procesu peletiranja nisu dovoljno obja&scaron;njene.<br />Najče&scaron;će se tumačenja svode na pretpostavke, bez obja&scaron;njenja o promenama<br />u veličini molekula proteina, kao i njihovoj koncentraciji. Inovativan pristup ove<br />doktorske disertacije je usmeren na opisivanje uticaja dodatka sojine i<br />suncokretovih sačmi različitog sadržaja proteina u sme&scaron;e na bazi kukuruza na<br />tehnolo&scaron;ke parametre procesa peletiranja, funkcionalne promene<br />makronutrijenata (želatinizaciju skroba i denaturaciju i degradaciju proteina) i<br />fizički kvalitet peleta. U okviru svake sme&scaron;e takođe je ispitivan uticaj procesnih<br />parametara, prečnika otvora sita mlina čekićara (2, 3 i 4 mm), vremena<br />produženog kondicioniranja parom (bez produženog kondicioniranja, 5 i 10<br />minuta) na fizički kvalitet peleta. Istraživanja su pokazala da temperatura<br />peletiranja, specifična potro&scaron;nja električne energije i udeo pra&scaron;ine u peletama<br />zavise od sirovinskog sastava sme&scaron;a, prečnika otvora sita mlina čekićara i<br />vremena zadržavanja u kondicioneru, pri čemu temperatura peletiranja i<br />specifična potro&scaron;nja električne energije rastu, a udeo pra&scaron;ine u peletama<br />opada sa porastom koncentracije proteina u sme&scaron;ama. Dokazano je i da<br />proces peletiranja utiče na funkcionalne promene makronutrijenata,<br />želatinizaciju skroba i strukturne promene na proteinima. Takođe je dokazano i<br />da za optimalno vreme zadržavanja materijala u kondicioneru, smanjenje<br />prečnika otvora sita mlina čekićara i povećanje sadržaja proteina u sme&scaron;ama<br />utiču na pobolj&scaron;anje fizičkog kvaliteta peleta, tj. tvrdoće peleta i stepena<br />otiranja peleta. Optimalni uslovi procesa peletiranja određeni su metodom<br />željene funkcije. Dat je predlog opsega procesnih parametara za dobijanje<br />peleta minimalnog stepena otiranja uz optimalnu specifičnu potro&scaron;nju<br />električne energije.<br />Istraživanja u ovoj doktorskoj disartaciji dala su doprinos novim saznanjima o<br />uticaju dodatka sačme različitog sadržaja proteina (37,3, 40,3 i 42,6 %) na<br />fizički kvalitet peleta. Kvalitet peleta sa dodatkom suncokretove sačme je<br />poređen sa kvalitetom peleta sa dodatom sojinom sačmom, kao i kvalitetom<br />peleta od čistog kukuruza, u cilju obja&scaron;njenja uticaja izvora i koncentracije<br />proteina. Ispitivanja su vr&scaron;ena ne samo za standardno vreme kondicioniranja,<br />nego uz primenu najsavremenijih postupaka termičke obrade hrane za<br />životinje, tj. uz upotrebu produženog kondicioniranja od 5 i 10 minuta.<br />Doprinos nauci je dat i time &scaron;to je pokazano da proces peletiranja utiče ne<br />samo na denaturaciju i degradaciju proteina, nego i na njihovo povezivanje.</p> / <p>Sunflower meal has a lesser presence in pelleted compound feed than<br />soybean meal due to a higher proportion of raw fiber. Raw fiber has<br />depressing effect on the digestibility and production results, and can have a<br />negative impact on the physical quality of the pellets. Lately, considerable<br />attention is paid to the functional changes of macronutrients in pelleting of<br />animal feed. It is believed that these changes have a positive impact on the<br />physical quality of the pellets. With the development of modern analytical<br />techniques, especially the thermal analysis, it is possible to describe the<br />changes of starch in pelleting process, caused by the impact of heat and<br />moisture. On the other hand, changes of the protein components in the<br />pelleting process are not sufficiently explained. The most common<br />interpretation is reduced to the presumption, with no explanation of changes in<br />the size of protein molecules, as well as in their concentration. The innovative<br />approach of this dissertation is focused on describing the effect of the addition<br />of soybean meal and sunflower meals, with different protein content, in<br />mixtures based on corn, on the technological parameters of the pelleting<br />process, functional changes of macronutrients (starch gelatinization, and<br />protein denaturation and degradation), and physical quality of the pellets.<br />Within each of the mixtures, the influence of process parameters, the diameter<br />of the hammer mill sieve openings (2, 3 and 4 mm), duration of long term<br />steam conditioning (without extended conditioning, 5 and 10 minutes) on the<br />physical quality of the pellets was also investigated. Studies have shown that<br />pelleting temperatures, the specific power consumption and the proportion of<br />dust in pellets were dependent of composition of the mixtures, the diameter of<br />the hammer mill sieve openings, and residence time in the conditioner.<br />Pelleting temperature and specific power consumption increased, and the<br />extent of fines in pellets decreased with increasing of concentration of protein<br />in the diets. Additionally, it is proved that pelleting process affects functional<br />changes of macronutrients, starch gelatinization and structural changes in<br />proteins. It is also proved that for the optimal retention time of material in<br />conditioner, decrease of diameter of the hammer mill sieve openings and<br />increase of protein content in the diets had positive effect on the physical<br />quality of pellets, i.e. pellet hardness and degree of abrasion of pellets. The<br />optimum process conditions in pelleting process were determined by the<br />method of desired function. A proposal has been made for setting the range of<br />process parameters for obtaining the minimum degree of abrasion of pellets,<br />with optimal specific energy consumption.<br />The research within this Ph.D. thesis contributed to the knowledge about the<br />effects of addition of sunflower meal with different protein content (37.3, 40.3<br />and 42.6 %) on the physical quality of the pellets. Quality of pelleted mixtures<br />with sunflower meal added were compared with the quality of pelleted mixtures<br />with soybean meal added and quality of pelleted corn, in order to explain the<br />effects of starch concentration, protein concentration and protein source.<br />Studies were performed not only for the standard time of conditioning, but with<br />the use of modern techniques for heat treatment of animal feed, i.e. with the<br />use of long term conditioning process for a 5 or 10 minutes. Additional<br />contribution to science has been given with showing that the pelleting process<br />causing not only the denaturation and degradation of proteins, but also<br />synthesis of proteins.</p>

This thesis addresses the problem healthcare facilities are having in maintaining proper food temperatures while transporting meals to patients after food has left the kitchen area. Induction heat has been a known method for generating heat for many years. The commercial food industry currently uses this technology, which is beginning to appear in the residential sector as well because of developments made by manufacturers. This study focuses on the top commercial brand models of induction heaters and the supporting materials currently used to create heat sources to maintain food temperatures in hospitals and long term care facilities. The research in this thesis includes data recorded from 6,000 total induction cycles from the 3 leading induction heating models. The focus of the research was to gather data concerning the models’ reliability to consistently create the intended inducement of radio frequency waves as well as deliver consistent temperature reactions from the recorded induction cycles. There were 18,000 temperature data points recorded during different time intervals for each of the induction cycles for the entire study. The results indicate the current technology not only is reliable in creating inductions fields but also in delivering consistent temperatures in the supporting materials being heated. Induction has been used historically as a fast heating process to treat large metal products and requires no direct contact to create or transfer heat to a surface (Rudnev et al., 2003). The speed and consistent application of heat transfer that has been derived by modern manufacturing induction practices makes it a logical use of existing technology to be applied in maintaining temperatures of food in the healthcare market. However, the focus for commercial equipment manufacturers has been to market products that can consistently maintain desired food temperatures, particularly in the healthcare industry. Traditionally, heating foods was accomplished by physically applying heat to areas where food is stored, in order to reach a certain temperature, and then working to deliver that food to the patient in a timely manner or before it cooled to temperatures that would be deemed too cold for consumption. If the food was too cold, before it was served to the patient, then it was typically micro waved in order to reheat the food. However, reheating food in the microwave is not only detrimental, but it also degrades food quality, texture, and visual presentation (Harvard Health, 2015). As a result, the effort demanded to deliver all foods to all patients, while the food is still at an ideal temperature, has resulted in an increased cost of labor. This is because healthcare facilities have had to hire additional workers to meet the demands placed on the nutrition department related to safe temperatures and speed of food delivery (Aladdin, 2013).