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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The chemical and sensorial effects of plant-based fining agents on Washington State Riesling and Gewürztraminer wines

Hill, Laura Ellen. January 2009 (has links) (PDF)
Thesis (M.S. in food science)--Washington State University, December 2009. / Title from PDF title page (viewed on Jan. 19, 2010). "School of Food Science." Includes bibliographical references (p. 94-99).
2

The impact of fining on the chemical and sensory properties of Washington State Chardonnay and Gewürztraminer wines

Sanborn, Melissa, January 2008 (has links) (PDF)
Thesis (M.S. in food science)--Washington State University, August 2008. / Includes bibliographical references (p. 80-88).
3

Ottimazione dei processi di chiarificazione di vini bianchi mediante l'impiego di bentonite / Optimization of white wine clarification processes by means of bentonites

DORDONI, ROBERTA 24 February 2011 (has links)
La presente tesi di dottorato ha riguardato la valutazione di differenti campioni di bentoniti sodiche. Le attività pianificate sono state indirizzate a comprendere l’interazione dei suddetti materiali con proteine a diverso peso molecolare naturalmente contenute nei vini bianchi. Ulteriori indagini hanno riguardato l’eventuale impatto delle argille testate sui composti aromatici di origine varietale e fermentativa dei mosti e/o dei vini. I risultati sottolineano il ruolo chiave esercitato dal “fattore matrice”: oltre al tipo di vino, prima di pianificare un trattamento di fining, devono essere considerate anche la tipologia e la dose di bentonite da utilizzare. / This PhD thesis dealt with the evaluation of different sodium bentonite samples. The planned activities were aimed to understand the interactions between bentonites and different molecular weight proteins naturally contained in white wines. Further investigations were related to the impact of the clays on varietal and fermentative aroma compounds of musts and/or wines. Results underscore the key role exerted by the “matrix factors”: bentonite dose and typology and wine style have to be carefully considered before planning a fining treatment.
4

Redox reactions and structure - properties relations in mixed alkali/alkaline earth glasses : - The role of antimony oxides during the fining process- A structural study of copper(I) and copper(II)

Grund Bäck, Lina January 2015 (has links)
It is important to optimize glass compositions for their specific purpose but also for the efficiency of the production process, the manufacturing of glass. This will be beneficial economically and environmentally. Today many processes and glass compositions are already optimized, but due to more strict legislation on toxic elements and substances there must be changes in many glass compositions. One of these elements is antimony; the oxide is used as fining agent to obtain a bubble free glass within a reasonable process time. One aim with this thesis is to obtain a deeper understanding of the fining mechanism in 20R2O-10MO-70SiO2 (R=Na and/or K, M = Ca and/or Ba, Mg, Sr) glasses in order to minimise the amount of Sb2O3. Another intention is to study the structure of 20R2O-10CaO-70SiO2 (R = Na, K) with Cu2+ as probe ion and thus get a deeper knowledge of the surrounding glass matrix.  The optical basicity scale is used to determine the acid/base character of the different glass compositions.   Fining efficiency results showed a remarkable increase of the number of remaining bubbles when the glass contains either approximately equal amounts of Na and K or Ca and Ba, Mg or Sr. The much higher number of bubbles in the potassium containing glasses compared to the sodium containing is explained by the increase in viscosity, the increase in optical basicity and thus lower oxygen activity. The differences in the fining efficiency when altering alkaline earth ions cannot be explained by the optical basicity values, it seems to be a more complicated situation.   This thesis also reports maximum in Vickers hardness and packing density as well as minimum in glass transition temperature for the mixed alkali glasses. The mixed alkaline earth glasses do not exhibit any clear nonlinear behaviour. Raman spectroscopy measurements showed a variation in the network connectivity which has a clear relation to the optical basicity of the different glass compositions. The combination of UV-Vis-NIR and X-ray absorption spectroscopy measurements showed that the coordination sphere for Cu(II) is a tetragonal distorted octahedron with two elongated Cu-O bonds along the z axis. There were no trends in the degree of tetragonal distortion, thus it was about the same for all the investigated glass compositions. Cu(I) is found to be coordinated by two oxygen ligands in mainly linear coordination sphere, evidenced from X-ray absorption spectroscopy.
5

The effects of dissolved oxygen and enological treatments on quality parameters in wine and cider

Ragnemalm, Johan January 2014 (has links)
Dissolved oxygen has previously been shown to affect the colour and sensory properties of red and white wine during storage. A number of different wines and wine based sparkling ciders are made at Kiviks Musteri AB. The aim of this work is to study the effects of dissolved oxygen and different enological treatments on sensory quality and colour of red wine and sparkling apple cider during storage at different temperatures. The effects of fermentation and fining on foaming ability of pear wine are also studied.   Samples of red wine were taken after different processing steps such as pumping, sulphuration, pasteurization and filling. To evaluate the effects of the processes on the wine, dissolved oxygen, colour and free SO2 were measured in each. Measurements were also made on samples of red wine stored at either 38°C or room temperature for different amounts of time. Sensory evaluations were also made of the wine samples. Colour was measured by measuring absorbance at 420, 520 and 620 nm. Dissolved oxygen was also measured after different processing steps during production of apple cider. To study the effects of dissolved oxygen on cider, three different batches of apple cider were produced, with different concentrations of dissolved oxygen. The samples were stored at either 38°C or room temperature for one week. Measurements of absorbance at 420 nm and free SO2, along with sensory evaluation were made on the cider samples before and after storage. Fermentation and fining of pear wine were made in small scale and the foaming ability was compared to that of large scale factory produced wine.   Pumping and filling had negative impact on the flavour of red wine. Colour intensity increased while free SO2 decreased during storage of red wine. The sensory quality decreased during storage and a higher storage temperature had a distinctive impact on this decrease. Dissolved oxygen had no noticeable effect on changes in sensory properties of neither red wine nor cider during storage. A higher concentration of dissolved oxygen was correlated to a higher increase in colour intensity of red wine though. A higher decrease was also seen in free SO2 in red wine samples with higher dissolved oxygen content when stored at 38°C. Fermentation had a large impact on foaming properties of pear wine. Small scale wine fermentation resulted in much lower foaming ability than large scale fermentation. / Syrehalten i viner har i tidigare studier visat sig kunna påverka både färg- och smakförändringar i vinerna under längre tids lagring. På Kiviks Musteri AB i Skåne produceras en mängd olika sorters vin och vinbaserade cidrar. Målet med den här studien är att studera vilken effekt syrehalten har på smak och färg i viner och cidrar från Kiviks Musteri som får lagras i olika temperaturer. Effekten av olika processteg under produktionen studeras också. Slutligen studeras även hur skumbildningen i päronvin påverkas av jäsning och klarning av vinet.   Prover av rödvin togs efter de olika processtegen vinet genomgår på Kiviks Musteri. Proverna lagrades olika länge i antingen 38°C eller rumstemperatur. Färgstyrka och smak analyserades på proverna före och efter lagringen. Syrehalten analyserades också i proverna direkt efter att de tagits och svavelhalten i proverna analyserades före och efter lagringen för att mäta hur mycket proverna oxiderades under lagringen. Mätningar av syrehalt gjordes även efter olika processteg under produktionen av äppelcider på Kiviks Musteri. Vilken effekt syrehalten har på äppelcider studerades genom att tre olika satser äppelcider med olika syrehalt tillverkades. Prover från dessa lagrades en vecka i antingen 38°C eller rumstemperatur. Därefter analyserades färgstyrka, svavelhalt och smak på proverna. Hur skumbildning i päronvin påverkas av jäsning och klarning studerades genom att päronvin fick jäsa och klarnas antingen i stor skala i musteriets tankar eller i liten skala på ett laboratorium. Skumbildningen mättes genom ett test där vinprover blandades med kolsyrat vatten.   De processer som inverkade starkast på smaken på rödvin var pumpning och tappning, vilka gav tydliga smakförsämringar. När rödvin lagrades så minskade svavelhalten medan färgstyrkan ökade. En försämring av smaken skedde också under lagringen, särskilt när vinet lagrades i 38°C. Syrehalten hade ingen tydlig påverkan på smaken av vare sig rödvin eller äppelcider. Syrehalten i rödvin hade däremot ett svagt samband med ökningen i förgstyrka i rödvin. Syrehalten hade även ett samband med minskningen av svavelhalten i de prover av rödvin som lagrades i 38°C. Skumbildningen i päronvin påverkades väldigt starkt av jäsningen, medan klarningen hade begränsad effekt. Skumbildningen var vesäntligt mycket lägre i päronvin som jäst i liten skala på laboratoriet än i det vin som jäst i musteriets tankar.
6

Tendências granulométricas dos sedimentos de fundo no Rio Marrecas, região Sudoeste do Paraná / Downstream finning of bottom sediments in the Marrecas river, South West region of Paraná

Luz, Constantino Eleuthério da 23 November 2011 (has links)
Made available in DSpace on 2017-07-10T17:31:15Z (GMT). No. of bitstreams: 1 Constantino_Eleutherio_Luz.pdf: 2845155 bytes, checksum: f9e51c3d07bfcebf178a79ea1cc6f916 (MD5) Previous issue date: 2011-11-23 / The dissertation examines the downstream finning phenomenon as it operates in the bottom sediments in the Marrecas river, located in South West region of Parana state, Brazil. The area of basin has 865,43 km2 and encompasses he municipalities of Francisco Beltrão, Marmeleiro, Flor da Serra do Sul, Verê and Itapejara D Oeste. The Marrecas river basin inserted in Cretaceous age rock composed of basaltic rocks of the Serra Geral Formation with plateaus characterized by dissecting medium and high, elongated tops and slopes convex and straight. Were calculated the main basin morphometric index based on 1:260,000 scale map and longitudinal thalweg profile of the main channel based on 1:50,000 scale topographic maps. The botton sediments samples was performed in December 2009 and January 2010 with a van Veen samples in a location preferably located in the vicinity of the main tributaries of Marrecas river and easy access to river banks. The sandy and coarse sediments were analyzed by sieving techniques and use of gravelometer device. Were calculated grain-size statistical parameters: mean, median, sorting, skewness and kurtosis as defined by Folk & Ward (1957). The sphericity of the coarse sediments was defined by adopting the classification of Zingg (1935). The trends observed particle size showed a clear downstream finning of botton sediments in the downstream direction, changed locally due to the contribution of sediments by tributaries. The sorting showed no trend with values ranged from moderately to very poorly. Skewness shows a trend of variation of positive values in the upper reaches of the Marrecas river for negative values in the lower reaches, while the kurtosis showed a slight tendency passing values platikurtic to leptokurtic. The predominance of spherical shape in bottom sediments was attributed to spheroidal weathering and low resistance to abrasion of the rock. / A presente dissertação trata sobre a variação longitudinal das características texturais dos sedimentos de fundo no rio Marrecas, localizado na região Sudoeste do Paraná. A área da bacia do rio Marrecas possui 865,43 km2 e abarca parte dos municípios de Francisco Beltrão, Marmeleiro, Flor da Serra do Sul, Verê e Itapejara D Oeste. O total da bacia do rio Marrecas está inserida em terrenos de idade cretácea formada por rochas basálticas da formação Serra Geral que formam planaltos caracterizados por dissecação média e alta, topos alongados, vertentes convexas e retilíneas. Foram calculados os principais índices morfométricos da bacia baseados em mapas em escala 1:260.000 e elaborado perfil longitudinal do canal principal com base em cartas topográficas em escala 1:50.000. A coleta de sedimentos de fundo foi executada em dezembro de 2009 e janeiro de 2010, com amostrador de mandíbula tipo Van Veen em locais situados preferentemente nas imediações dos principais afluentes do rio Marrecas e em trechos de acesso fácil às margens do rio. Os sedimentos arenosos e rudáceos foram analisados mediante técnicas de peneiramento e emprego de cascalhômetro. Foram calculados os seguintes parâmetros estatísticos: diâmetro médio, mediana, grau de seleção, assimetria e curtose segundo a definição de Folk & Ward (1957). A esfericidade dos sedimentos rudáceos foi definida adotando a classificação de Zingg (1935). As tendências granulométricas observadas mostraram uma nítida granodecrescência dos sedimentos de fundo em direção à jusante, alterada localmente devido ao aporte de sedimentos pelos afluentes. O grau de seleção não mostrou nenhuma tendência e variou de moderadamente a muito pobremente selecionado. A assimetria mostra uma tendência de variação de valores positivos nos trechos superiores do rio Marrecas para valores negativos nos trechos inferiores, enquanto que a curtose exibiu uma passagem de valores platicúrticos para leptocúrticos em direção à jusante. O predomínio da forma esférica nos sedimentos de fundo foi atribuído a decomposição esferoidal do basalto e a baixa resistência desta rocha à abrasão.
7

Tendências granulométricas dos sedimentos de fundo no Rio Marrecas, região Sudoeste do Paraná / Downstream finning of bottom sediments in the Marrecas river, South West region of Paraná

Luz, Constantino Eleuthério da 23 November 2011 (has links)
Made available in DSpace on 2017-05-12T14:42:47Z (GMT). No. of bitstreams: 1 Constantino_Eleutherio_Luz.pdf: 2845155 bytes, checksum: f9e51c3d07bfcebf178a79ea1cc6f916 (MD5) Previous issue date: 2011-11-23 / The dissertation examines the downstream finning phenomenon as it operates in the bottom sediments in the Marrecas river, located in South West region of Parana state, Brazil. The area of basin has 865,43 km2 and encompasses he municipalities of Francisco Beltrão, Marmeleiro, Flor da Serra do Sul, Verê and Itapejara D Oeste. The Marrecas river basin inserted in Cretaceous age rock composed of basaltic rocks of the Serra Geral Formation with plateaus characterized by dissecting medium and high, elongated tops and slopes convex and straight. Were calculated the main basin morphometric index based on 1:260,000 scale map and longitudinal thalweg profile of the main channel based on 1:50,000 scale topographic maps. The botton sediments samples was performed in December 2009 and January 2010 with a van Veen samples in a location preferably located in the vicinity of the main tributaries of Marrecas river and easy access to river banks. The sandy and coarse sediments were analyzed by sieving techniques and use of gravelometer device. Were calculated grain-size statistical parameters: mean, median, sorting, skewness and kurtosis as defined by Folk & Ward (1957). The sphericity of the coarse sediments was defined by adopting the classification of Zingg (1935). The trends observed particle size showed a clear downstream finning of botton sediments in the downstream direction, changed locally due to the contribution of sediments by tributaries. The sorting showed no trend with values ranged from moderately to very poorly. Skewness shows a trend of variation of positive values in the upper reaches of the Marrecas river for negative values in the lower reaches, while the kurtosis showed a slight tendency passing values platikurtic to leptokurtic. The predominance of spherical shape in bottom sediments was attributed to spheroidal weathering and low resistance to abrasion of the rock. / A presente dissertação trata sobre a variação longitudinal das características texturais dos sedimentos de fundo no rio Marrecas, localizado na região Sudoeste do Paraná. A área da bacia do rio Marrecas possui 865,43 km2 e abarca parte dos municípios de Francisco Beltrão, Marmeleiro, Flor da Serra do Sul, Verê e Itapejara D Oeste. O total da bacia do rio Marrecas está inserida em terrenos de idade cretácea formada por rochas basálticas da formação Serra Geral que formam planaltos caracterizados por dissecação média e alta, topos alongados, vertentes convexas e retilíneas. Foram calculados os principais índices morfométricos da bacia baseados em mapas em escala 1:260.000 e elaborado perfil longitudinal do canal principal com base em cartas topográficas em escala 1:50.000. A coleta de sedimentos de fundo foi executada em dezembro de 2009 e janeiro de 2010, com amostrador de mandíbula tipo Van Veen em locais situados preferentemente nas imediações dos principais afluentes do rio Marrecas e em trechos de acesso fácil às margens do rio. Os sedimentos arenosos e rudáceos foram analisados mediante técnicas de peneiramento e emprego de cascalhômetro. Foram calculados os seguintes parâmetros estatísticos: diâmetro médio, mediana, grau de seleção, assimetria e curtose segundo a definição de Folk & Ward (1957). A esfericidade dos sedimentos rudáceos foi definida adotando a classificação de Zingg (1935). As tendências granulométricas observadas mostraram uma nítida granodecrescência dos sedimentos de fundo em direção à jusante, alterada localmente devido ao aporte de sedimentos pelos afluentes. O grau de seleção não mostrou nenhuma tendência e variou de moderadamente a muito pobremente selecionado. A assimetria mostra uma tendência de variação de valores positivos nos trechos superiores do rio Marrecas para valores negativos nos trechos inferiores, enquanto que a curtose exibiu uma passagem de valores platicúrticos para leptocúrticos em direção à jusante. O predomínio da forma esférica nos sedimentos de fundo foi atribuído a decomposição esferoidal do basalto e a baixa resistência desta rocha à abrasão.
8

Theoretische Betrachtung des Glasschmelzprozesses in Glasschmelzöfen

Wiltzsch, Sven 03 May 2014 (has links) (PDF)
Die vorliegende Arbeit beinhaltet die theoretische Betrachtung des Glasschmelzprozesses in Glasschmelzöfen und die Darstellung von fünf Bewertungsprinzipien zur qualitativen Bewertung von Glasschmelztechnologien für die Abschmelz-, Restquarz- und Läuterzone. Es konnte gezeigt werden, dass zum verbesserten Einschmelzen des Gemenges nicht nur der Energieeintrag, sondern auch der Abtransport der neu entstehenden Schmelze intensiviert werden muss. Bei der qualitativen Bewertung und der Auswahl von Schmelztechnologien zur Beschleunigung der Restquarzlösung wurde dargestellt, dass der Einfluss der Schmelztechnologie auf das Verweilzeitverhalten und damit rückwirkend auf die Effizienz der Restquarzlösezone bei der Vorauswahl von Schmelztechnologien berücksichtigt werden muss. Für die Läuterzone wurde nachgewiesen, dass zwei teils in der Literatur diskutierte Bewertungsprinzipien zur Läuterung von Glasschmelzen abzulehnen sind bzw. zu überschätzten Aussagen zur Effizienz von Läutertechnologien führen. Weiterhin konnte gezeigt werden, dass für den theoretischen Fall einer Läuterbank ohne Konvektionsströmungen die Blasenwachstumsgeschwindigkeiten für Konstruktionen mit minimalen Kosten im Bereich von 4-12*10-7 m/s mit möglichen Ausreißern zu 5*10-6 m/s bei Massengläsern liegen sollten.
9

Sediment Transport Conditions Near Culverts

Rowley, Kyle Jay 01 August 2014 (has links) (PDF)
Relatively little work has been done to understand how coarse grained sediments behave near culverts. Particularly for embedded culverts, sediment transport must be understood to achieve sustainable culvert designs for aquatic organism passage and peak discharge requirements. Several culvert sites in the Wasatch Mountains of Utah were studied through the spring flood season of 2014. Data obtained from the culvert sites were used to create numerical models with the Sedimentation and River Hydraulics Two-Dimensional model. The field sites and numerical model were used to study deposition of sediments at the entrance to culverts, sediment replenishment inside culverts, and lateral fining within the culvert barrel. Each element of the study was observed in the field. It was shown that the Sedimentation and River Hydraulics Two-Dimensional model is a useful tool to simulate the observed phenomenon of sediment deposition upstream of culverts, sediment replenishment, and lateral fining. Sedimentation and River Hydraulics Two-Dimensional model should be used in culvert design procedures as a means to understand sediment transport conditions.This work documents the first time that deposition of sediments upstream of a culvert and lateral fining within a culvert barrel have been successfully modeled. The work shows that culvert replenishment occurs naturally in many scenarios and should be simulated as part of the culvert design process. The results from this work will be useful for future design guidelines for culvert installations.
10

Clarificação de suco de laranja core wash por processo de flotação auxiliado por enzimas pectinolíticas e agentes clarificantes

Albuquerque, Carolina Maria [UNESP] 14 August 2009 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:24:46Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-08-14Bitstream added on 2014-06-13T18:21:12Z : No. of bitstreams: 1 albuquerque_cm_me_sjrp.pdf: 2192673 bytes, checksum: 95c4d486da5e0308e967a8ea5475dd6c (MD5) / A recuperação dos sólidos solúveis presentes na membrana central da laranja, separada durante a etapa de extração industrial do suco, normalmente produz um suco contendo de 5 a 6ºBrix e uma série de outros compostos insolúveis (cerca de 9%), muitos dos quais contribuem para a baixa qualidade do suco, sendo responsáveis pelo amargor e adstringência. O presente trabalho propôs-se a clarificar esse suco contendo sólidos recuperados, empregando um pré-tratamento com enzimas pectinolíticas seguido por tratamento por flotação por injeção de ar comprimido auxiliada por agentes clarificantes: bentonita, sílica sol e colágeno hidrolisado. Constituíram-se os objetivos: (i) a determinação das melhores condições (tipo de enzima pectinolítica, duas hidrolases e duas pectinases, e tempo de incubação) para a degradação enzimática da pectina presente; (ii) a determinação da melhor combinação dos agentes clarificantes visando obter um subproduto clarificado através do monitoramento de parâmetros físico-químicos (capacidade floculante e transmitância) e (iii) a avaliação do processo de flotação com diferentes concentrações de bentonita (500, 1.000 e 1.500 mg L-suco-1 e pressões (490, 680 e 880 kPa) pela determinação do grau de clarificação através de monitoramento da transmitância do clarificado, pela determinação da velocidade de flotação/separação das fases, através da verificação das frações volumétricas das fases separadas (clarificado, sedimentado e flotado), em intervalos de tempos regulares durante o processo de flotação e pela análise do produto final clarificado. Os produtos clarificados foram analisados com relação ao conteúdo de sólidos solúveis e insolúveis, pH, acidez titulável, polpa, transmitância, cor (parâmetros L*, a*, b*) proteína, pectina total, sódio, hesperidina, polifenóis e bioflavonóides. Para o tratamento... / Core membrane of the orange fruit separated during the juice extraction step in the citrus processing industrial plant, is currently submitted to a soluble solids recovery process, normally producing a by product (secondary) juice containing about 5 to 6º Brix and other insoluble components (about 9%), which contribute to the juice’s low quality, since many are responsible for the bitterness and adstringency. This research aimed to clarify this by-product juice containing recovered solids, by enzyme pre-treatment with pectic enzymes, followed by a flotation treatment with compressed air injection using fining agents: bentonite, silica sol and hydrolyzed collagen. The objectives were (i) to determine the best conditions (enzyme type, two hydrolyses and two pectin-liases and incubation time) for the enzyme treatment for pectin degradation; (ii) to determine the best combination of the fining agents to obtain a clarified by-product through monitoring physical chemical parameters (flocculating ability and product transmittance); and (iii) to evaluate the flotation process and the effects of bentonite concentration (500, 1.000 and 1.500 mg L-juice-1) and saturation pressure (490, 680 and 880 kPa) by determining the degree of clarification through monitoring the product transmittance and by determining the flotation rate (and phase separation) through measurements of volumetric fractions of the separated phases (clarified, floated and sediment) over time during the flotation and phase separation processes. Both untreated and clarified juices were analyzed for soluble and insoluble solid contents, pH, total titratable acidity, pulp content, transmittance, color (parameters L*, a* and b*), protein and pectin contents, sodium, hesperidine, poliphenols and bioflavonoids. The results indicates a purified poligalacturonase as the adequate for the enzyme treatment in 1 hour, 45ºC, with 0,05 mL... (Complete abstract click electronic access below)

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