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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.
71

Estudo comparativo das caracteristicas sensoriais do rum e da cachaça /

Magnani, Bruna Dias. January 2009 (has links)
Orientador: João Bosco Faria / Banca: João Bosco Faria / Banca: Daniela Cardoso Umbelino Cavallini / Banca: Maria Regina Bueno Franco / Resumo: Tendo em vista diminuir eventuais dúvidas em relação à identidade da cachaça brasileira, cuja exportação tem aumentado consideravelmente nos últimos anos, foi objetivo do presente trabalho estabelecer as diferenças sensoriais entre o rum e a cachaça, aguardentes oriundas da cana-de-açúcar, porém distintas. Nesse sentido, foi realizado um estudo comparativo entre amostras de rum e de cachaça obtidas em laboratório sob condições praticamente idênticas, visando estabelecer seus perfis sensoriais e descrever as similaridades e diferenças entre essas bebidas. Assim, quatro amostras, sendo uma de aguardente de melaço, outra de cachaça e mais duas envelhecidas, sendo uma de rum e outra de cachaça envelhecida, tiveram seus perfis sensoriais determinados por Análise Descritiva Quantitativa (ADQ), por uma equipe de 7 julgadores treinados e selecionados de acordo com seu poder discriminativo, reprodutibilidade dos julgamentos e consenso com a equipe. Para descrever e comparar os perfis sensoriais das diferentes amostras foram levantados e quantificados 17 atributos sensoriais. Os dados obtidos foram submetidos à análise de variância (ANOVA), testes de média de Tukey e análise de componentes principais (ACP). Os resultados revelaram haver diferenças significativas (p ≤ 0,05) entre as características sensoriais das amostras e os dois primeiros componentes principais explicaram juntos 98,49% (ACP) das variações entre as amostras em relação aos seus atributos sensoriais. Os atributos que contribuíram para a diferenciação do rum e da cachaça envelhecida foram cor dourada, corpo, turbidez, aroma amadeirado, sabor madeira, sabor adocicado e viscosidade, enquanto que as amostras de aguardente de melaço e cachaça sem envelhecer foram diferenciadas pelos atributos aroma metálico, sabor metálico e pungência. / Abstract: In order to reduce fortuitous doubts about the identity of Brazilian cachaça, whose export has increased considerably in recent years, it was goal of this study to establish sensory differences between rum and cachaça , spirits from the sugar cane, distinct however. Therefore, it was realized a comparative study among samples of rum and cachaça obtained in laboratory through practically identical conditions, to establish their sensory profiles and describe the similarities and differences between these beverages. Thus, four samples, one of molasses spirit and another of cachaça, and more two aged, which were, one of rum and another of aged cachaça had their sensory profiles determined by Quantitative Descriptive Analysis (QDA) conducted by a panel of 7 trained panelists and selected according to their discriminatory potential, reproducibility of trials and consensus with the panel. To describe and compare the sensory profiles of the different samples were developed and quantified 17 sensory attributes. The obtained data were submitted to analysis of variance (ANOVA), Tukey tests and Principal Components Analysis (PCA). The results revealed significant differences (p ≤ 0,05) about the sensory characteristics of spirits and the first principal component and the second principal component explained together 98.49% (PCA) of variations among the samples on their sensory attributes. The attributes that contributed to the differentiation of rum and aged cachaça were golden color, body appearance, turbidity, wood aroma, wood flavor, sweet taste and viscosity, while the samples of molasses spirit and non-aged cachaça were differentiated by attributes metallic aroma, metallic taste and pungency chemestetic. The results showed that the process of aging provided higher intensity of favorable sensory attributes for aged cachaça. / Mestre
72

Comportamento de linhagens industriais de Saccharomyces frente a compostos inibitorios presentes no melaço de cana-de-açucar na produção de bioetanol / Behavior of industrial strains of Saccharomyces front inhibitory compunds present in sugarcane molasses in the production of biothenol

Tosetto, Gisele Mantei 07 November 2008 (has links)
Orientador: Silvio Roberto Andrietta / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-11T09:00:01Z (GMT). No. of bitstreams: 1 Tosetto_GiseleMantei_D.pdf: 7845574 bytes, checksum: c216dd147ba44b14c8004a51300ce14b (MD5) Previous issue date: 2008 / Resumo: O objetivo geral deste trabalho foi avaliar os efeitos de algumas substancias organicas presentes no melaco de cana-de-acucar sobre cepas de leveduras de uso industrial. O Capitulo I refere-se a uma breve introducao e historico da fermentacao alcoolica. No Capitulo II, foi analisado amostras de melacos industriais, provenientes de 10 unidades produtoras de acucar e alcool, localizadas nos estados de Sao Paulo, Minas Gerais, Goias e Parana, com a finalidade de determinar e quantificar alguns compostos organicos presentes no mesmo. Para tanto foi utilizada a tecnica de Cromatografia Liquida de Alta Eficiencia (CLAE). No Capitulo III foram realizados ensaios para escolher as cepas de melhor desempenho em condicoes de estresse, utilizando-se o planejamento fatorial 23 tipo estrela com triplicata no ponto central. Os fatores estudados foram: a pressao osmotica (utilizando KCl), temperatura e concentracao inicial de Alcool. As cepas Y904 e SA1 foram as que mais se destacaram. No Capitulo IV foram avaliados os efeitos dos compostos organicos (acidos cafeico, galico, latico, piruvico, siringico, vanilico, acetico, formico, butirico e Hidroximetilfurfural) sobre as cepas SA1 e Y904, atraves de fermentacoes em triplicata, utilizando meio sintetico controle e variando as concentracoes de cada composto. Dentro das concentracoes estudadas, apenas os acidos galico, latico, acetico, formico, butirico e Hidroximetilfurfural demonstraram influencia sobre as cepas. A avaliacao do efeito acumulativo das substancias quando se trabalha com reciclo de celulas esta descrita no Capitulo V. Todos os experimentos foram realizados em triplicata e repetidos por oito vezes consecutivas (8 ciclos). O acido latico foi a substancia que mais interferiu no rendimento em etanol (YP/S) e na produtividade, parametros estes de maior importancia nos processos industriais para producao de alcool. Por outro lado, o acido formico apresentou a menor interferencia e efeito negativo para praticamente todos os parametros estudados. Finalmente no Capitulo VI, foram analisados os efeitos dos acidos latico e formico sobre o comportamento cinetico das cepas SA1 e Y904. Os testes foram realizados em biorreator de bancada, por dez horas de fermentacao. O acido latico aumentou tanto a inibicao pelo substrato como pelo produto, mostrando-se ser uma substancia com alto grau de toxicidade para as celulas de leveduras das linhagens estudadas. " RANAXTAU/EJAXGU" / fermentacao alcoolica, cinetica, substratos industriais, compostos organicos, inibicao, levedura / Abstract: The general objective of this project was the evaluation of the effects of some organic substances present in molasses, sugar cane on strains of yeast for industrial use. Chapter I refer to a brief introduction and history of alcoholic fermentation. In Chapter II, samples of industrial molasses were examined, from 10 units producing sugar, located in the states of Sao Paulo, Minas Gerais, Goias, and Parana, in order to determine and quantify some organic compounds present in them. In order to this, the technique for High Performance Liquid Chromatography (HPLC) was used. In Chapter III trials were conducted to choose the strains of better performance in terms of stress, using a 23 factorial planning star type with triplicate in central point. The studied factors were: the osmotic pressure (using KCl), temperature and initial concentration of alcohol. The strains Y904 and SA1 were those which stressed most. In Chapter IV were assessed the effects of organic compounds (caffeic, gallic, lactic, pyruvic, syringic, vanillic, acetic, formic, butyric and Hidroximetilfurfural acids) on the strains SA1 and Y904 by the fermentation in triplicate, using synthetic medium and control varying concentrations of each compound. Within the concentrations studied, only the gallic acid, lactic acid, acetic acid, formic, butyric and Hidroximetilfurfural demonstrated influence on the strains. The assessment of the cumulative effect of the substances when working with recycle cell is described in Chapter V. All experiments were performed in triplicate and repeated by eight consecutive times (8 cycles). The lactic acid is the substance that interfere most in income in ethanol (YP/S) and productivity, these parameters of most importance in industrial processes to produce alcohol. Moreover, the formic acid showed the smallest negative interference for almost all parameters studied. Finally in Chapter VI, were analyzed the effects of lactic acid and formic on the behavior of kinetic strains SA1 and Y904. The tests were performed in bench bioreactor for ten hours of fermentation. The lactic acid increased by inhibiting both the substrate and the product, showing to be a substance with a high degree of toxicity to the strains of yeast cells studied. YQTFU" /" alcoholic fermentation, kinetics, industrial substract, organic compounds, inhibition, yeast / Doutorado / Desenvolvimento de Processos Biotecnologicos / Doutor em Engenharia Química
73

Codigestão de vinhaça e melaço em biorreator anaeróbio operado em bateladas sequenciais com biomassa imobilizada visando a produção de hidrogênio / Co-digestion of vinasse and molasses in an anaerobic sequencing batch biofilm reactor operated with immobilized biomass for hydrogen production

Roberta Albanez 24 November 2015 (has links)
Este estudo investigou a aplicação de um AnSBBR operado de forma descontínua e/ou descontínua alimentada com agitação mecânica, no processo de produção de hidrogênio a partir da codigestão de vinhaça e melaço. O desempenho do processo foi avaliado em função da eficiência de remoção da matéria orgânica, da estabilidade, e dos índices de desempenho referentes à produtividade e ao rendimento molar do hidrogênio e à composição do biogás gerado. Foram avaliadas a influência dos seguintes parâmetros: composição (codigestão com sacarose ou melaço) e concentração afluente, tempo de ciclo, suplementação de micronutrientes (completa/parcial/ausência), tipo de alimentação (batelada/batelada alimentada) e a necessidade do tratamento do inóculo. O sistema estudado se mostrou estável e a codigestão da vinhaça e melaço viável para produção de hidrogênio. Os melhores resultados foram obtidos na condição em que o reator foi operado em batelada (tempo de alimentação 5% do tempo de ciclo), afluente com concentração 6000 mgDQO.L-1 e composição 67% vinhaça e 33% melaço, tempo de ciclo de 3 horas, ausência da suplementação de micronutrientes e foi realizado tratamento térmico do inóculo. Nesta condição a produtividade molar foi de 13,5 mol H2.m-3.d-1 e metano não foi produzido. As demais condições mostraram que o aumento da porcentagem de vinhaça no afluente e a operação em batelada alimentada prejudicaram a produção de hidrogênio. O aumento da concentração da matéria orgânica do afluente, a diminuição do tempo de ciclo, a ausência da suplementação de micronutrientes e a realização do tratamento térmico do inóculo favoreceram a produtividade e rendimento molares de hidrogênio. / A mechanically stirred anaerobic batch and/or fed-batch reactor, containing biomass immobilized on inert support (AnSBBR) was investigated as to its ability to produce hydrogen from the co-digestion of vinasse and molasses. Process performance was assessed in terms of organic matter removal efficiency, stability, and of performance indicators related to hydrogen productivity and molar yield and to composition of the generated biogas. The effects of the following parameters have been assessed: influent composition and concentration (co-digestion with sucrose or molasses), cycle length, micronutrient supplementation (complete/partial/absence), feeding strategy (batch or fed-batch) and need for pre-treatment of the inoculum. The system showed to be stable and the co-digestion of vinasse and molasses showed to be feasible. The best results were obtained at the following conditions: 3-h cycle sequencing batch (feed time equaled 5% of cycle length), influent concentration of 6000 mgCOD.L-1 containing 67% vinasse and 33% molasses, preheating of the inoculum, and with no micronutrient supplementation. At this condition, the molar yield was 13.5 mol H2.m-3.d-1, and no methane was produced. The remaining conditions showed that increase in vinasse content in the influent and fed-batch operation were detrimental to system performance. The increase in organic matter concentration, reduction in cycle length, no micronutrient supplementation and inoculum preheating favored productivity and molar hydrogen yield.
74

Trapping and cooling of fermionic alkali atoms to quantum degeneracy : Sub-Doppler cooling of Potassium-40 and Lithium-6 in gray molasses / Piégeage et refroidissement d'atomes fermioniques alcalins jusqu'à dégénérescence quantique : refroidissement sub-doppler du Potassium-40 et du Lithium-6 dans des mélasses grises

Rio Fernandes, Diogo 29 September 2014 (has links)
Ce mémoire décrit la conception, la construction et la caractérisation d'un appareil capable de piéger et refroidir des atomes fermioniques de 6Li et 40K à des températures ultrabasses. L'étude des mélanges des gazes de Fermi dégénérés ouvre la porte vers la création des nouveaux systèmes quantiques à N corps. Nous présentons une nouvelle technique de refroidissement laser capable de refroidir simultanément 6Li et 40K à des températures sub-doppler basée sur un schéma de molasses grises fonctionnant sur la transition atomique D1. Cette stratégie améliore la densité dans le espace des phases des deux espèces atomiques à 104, la valeur la plus élevée rapportée dans la littérature pour le refroidissement laser du 6Li et du40K. L'optimisation d'un dispositif capable de transporter un nuage atomique piégé magnétiquement de l'enceinte MOT à une cellule de science est décrite. Dans cette cellule on effectue du refroidissement évaporatif d'abord dans un piège magnétique quadripolaire dont le zéro du champ est interdit par un potentiel répulsif et après dans un piège optique dipolaire. Nous rapportons la production d'un gaz quantique de Fermi dégénéré de 1.1x106 atomes de 40K dans un piège dipolaire croisé avec T/TF = 0.27,ouvrant la voie à la création des superfluides de 40K en interactions fortes. / This thesis describes the design, construction and characterization of an apparat us capable of trapping and cooling fermionic atoms of 6Li and 40K to ultracold temperatures.The study of mixtures of degenerate Fermi gases opens the door for the creation of new many-body quantum systems.We present a novel laser cooling technique able to simultaneously cool 6Li and 40K to the sub-Doppler regime based on the gray molasses scheme operating on the D1 atomic transition. This strategy enhances the phase space density of both atomic species to 104, the highest value reported in the literature for laser cooled 6Li and 40K. The optimization of a device able to transport a magnetically trapped atomic cloud from the MOT chamber to a science cell is described. In this cell evaporative cooling is performed first in a plugged magnetic quadrupole trap and then in an optical dipoletrap. We report the production of a quantum degenerate Fermi gas of 1.1x106 atoms40K in a crossed dipole trap with T/TF = 0.27, paving the way for the creation of strongly interacting superfluids of 40K.
75

Otimização do meio de cultura para a fermentação direta de melaço de cana para produção de ácido láctico por Lactobacillus delbrueckii spp. bulgaricus / Optimization of medium for direct fermentation of sugarcane molasses for lactic acid production by Lactobacillus delbrueckii spp. bulgaricus

Alcazar Alay, Sylvia Carolina 09 June 2011 (has links)
Orientador: Ranulfo Monte Alegre / Dissertação (mestrado) - Universidade Estsadual de Cam,pinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-18T17:54:10Z (GMT). No. of bitstreams: 1 AlcazarAlay_SylviaCarolina_M.pdf: 2176104 bytes, checksum: 32f8cdfe0b86e00e15edc533c76b33cb (MD5) Previous issue date: 2011 / Resumo: O interesse pela produção de ácido láctico tem crescido fortemente nos últimos anos desde a descoberta das propriedades de seus polímeros, os que apresentam caraterísticas de biodegradabilidade e biocompatibilidade; e sua aplicação como solvente ¿verde¿ ou ambientalmente saudável para os processos de misturas de solventes na indústria química. Dado o potencial econômico do ácido láctico, são necessários processos mais eficazes para sua síntese e redução dos custos de produção. Este trabalho visou aperfeiçoar o processo de produção fermentativa do ácido láctico, determinando formulações do meio de cultura que auxiliarão no desenvolvimento de tecnologias competitivas de produção. Além disso, esse trabalho propõe a utilização de matérias-primas de baixo custo e grande disponibilidade no mercado brasileiro como por exemplo melaço de cana e água de maceração de milho. A espécie selecionada para o estudo foi Lactobacillus delbrueckii, duas linhagens foram estudadas, selecionando-se a que apresentou maior velocidade de crescimento e produção de ácido láctico no meio de cultura padrão. O estudo de otimização da produção de ácido láctico foi realizado utilizando a estratégia de planejamentos experimentais. O uso de melaço de cana e água de maceração de milho como fonte de carbono e nitrogênio, em concentração de 240 gL-1 e 14 gL-1 respectivamente, possibilitou produtividade de até 57,17 gL-1 após 96 horas, com eficiência de 82% (gramas de ácido láctico produzido / grama de substrato utilizado) / Abstract: The interest in lactic acid has grown strongly in the last years since the discovery of its properties of application in production of biodegradable and biocompatible polylactate polymers and their application as "green solvent¿ or ¿safety solvent¿ to processes of mixtures of solvents in the chemical industry. Considering the commercial potential of lactic acid, more efficient processes are needed for its synthesis, reducing costs of production and turning its industrial application more atractive, as its cost still prevents it from being used in some areas. This work aimed at improving the process of fermentative lactic acid production, determining formulations that will help develop competitive technologies of production. Furthermore, the use of low cost raw materials, easily available on the brazilian market, such as sugarcane molasses and corn steep liquor is proposed. The species selected for the study was Lactobacillus delbrueckii, two strains were studied, Lactobacillus delbrueckii spp. bulgaricus, shown the greatest growth speed and lactic acid production in the standard culture medium. The optimization study of lactic acid production was performed using the strategy of experimental design, using sugarcane molasses as a carbon source and corn steep liquor as a nitrogen source allowed a productivity of up to 57,17 gL-1 after 96 hours, with 82% lactic acid yield efficiency (g lactic acid produced / g substrate utilized) using an initial concentration of 240 gL-1 and 14 gL-1 of sugarcane molasses and corn steep liquor respectively / Mestrado / Engenharia de Alimentos / Mestre em Engenharia de Alimentos
76

Produção enzimática de frutooligossacarídeos (FOS) por leveduras a partir de melaço de cana-de-açúcar / Production of fructooligosaccharides from sugarcane molasses by Saccharomyces cerevisiae and Kluveromyces marxianus cells

Carlos Eduardo Vieira da Silva 18 February 2009 (has links)
Frutooligossacarídeos (FOS), açúcares não convencionais, são oligossacarídeos de ocorrência natural principalmente em produtos de origem vegetal. Os FOS são produzidos através de uma reação enzimática de transfrutosilação em resíduos de sacarose resultando em 1-kestose (GF2), nistose (GF3) e frutofuranosil nistose (GF4). Com o objetivo de produzir frutooligossacarídeos (FOS) a partir do melaço de cana-de-açúcar, linhagens das leveduras Saccharomyces cerevisiae e Kluveromyces marxianus foram cultivadas em meio contendo sacarose ou melaço de cana de açúcar. Após diferentes períodos de cultivo, foram retiradas alíquotas para analisar açúcares redutores (AR) e redutores totais (ART) pelo método do DNS (ácido 3,5-dinitrossalicílico); o crescimento celular por turbidimetria a 600nm e a viabilidade celular por coloração com azul de metileno. A produção de frutooligossacarídeos foi acompanhada por cromatografia em papel ou cromatografia líquida. Através da análise qualitativa em cromatografia em papel foi observada a presença de FOS quando o meio contendo melaço foi cultivado por Kluveromyces marxianus o mesmo não ocorrendo para o Saccharomyces cerevisiae. Em meio contendo sacarose as duas leveduras não apresentaram nenhuma atividade de produção de FOS. / Fructooligosaccharides (FOS), sugars unconventional, are oligosaccharides of naturally occurring mainly in products of plant origin. The FOS are produced through an enzymatic reaction of transfructosylation of sucrose resulting in 1-kestose (GF2), nistose (GF3) and fructofuranosyl nistose (GF4). Aiming to produce fructooligosaccharides (FOS) from sugar cane molasses, strains of yeast Saccharomyces cerevisiae and Kluveromyces marxianus were grown in medium containing sucrose or sugar cane molasses. After different periods of cultivation, aliquots were removed to analyze reducing sugars (AR) and reducing total sugars (ART) by the method of DNS (3.5- dinitrossalicilic acid), the cell growth by turbidimetry to 600nm and cell viability by staining with methylene blue. The production of fructooligosaccharides was accompanied by chromatography on paper and liquid chromatography. Through qualitative analysis on chromatography on paper was observed the presence of FOS when the medium containing molasses cultivated by Kluveromyces marxianus otherwise cultivation by Saccharomyces cerevisiae did not resulted in the production of the FOS. Both of the yeast did not show any activity for the production of FOS when the medium contained sucrose.
77

Nutritivni profil, antioksidacioni potencijal i senzorski kvalitet specijalnih vrsta hlebova sa dodatkom melase šećerne repe / Nutrition profile, antioxidative potential and sensory quality of bread supplemented with sugar beet molasses

Filipčev Bojana 27 August 2009 (has links)
<p>U radu je ispitivan efekat dodatka čiste melase i voda/povrda (jabuke, &scaron;ljive, mrkva i crveni kupus), prethodno osmotski dehidriranih u melasi &scaron;ederne repe, na kvalitet hleba. Ispitivane su sledede grupe suplemenata u dve doze: čista melasa (5 i 10%, računato na bra&scaron;no), sveži (u obliku komadida osmotski dehidriranog voda/povrda, 10 i 30%, računato na bra&scaron;no) spra&scaron;eni (osu&scaron;eno i samleveno osmotski dehidrirano vode/povrde, 5 i 10%, računato na bra&scaron;no).<br />Dobijeni rezultati su pokazali da su ispitivani dodaci uticali na značajno pobolj&scaron;anje mineralnog sastava hleba. Najznačajni je povedanje u odnosu na kontrolni je zabeleženo u sadržaju kalijuma: za niže doze dodataka, najvede povedanje se kretalo u opsegu 89.1% (hleb sa melasom)-94.1% (hleb sa &scaron;ljivom u prahu) dok su za vi&scaron;e doze dodataka zabeležena slededa maksimalna povedanja:<br />157.5% (hleb sa kupusom u prahu) i 167.5% (hleb sa melasom). Hlebovi sa dodacima su takođe imali značajno vi&scaron;e sadržaje magnezijuma i kalcijuma u odnosu na kontrolni hleb. Najvi&scaron;i sadržaji Mg i Ca su određeni u hlebovima sa dodatkom vi&scaron;e doze kupusa u prahu (58 i 100%, respektivno). Hlebovi sa dodacima su pokazivali značajno vi&scaron;i antioksidacioni potencijal, pri čemu su najvi&scaron;i potencijali zabeleženi u hlebu sa dodatkom &scaron;ljive u prahu, 62.5-81.6% za 5 i 10% dodatak, respektivno.<br />Dodaci na bazi melase su uticali na promenu fizičkih, teksturnih i senzorskih svojstava hleba u pravcu smanjenja specifične zapremine, povedanja čvrstode sredine i potamnjivanja boje. Međutim, pri nižim dozama dodataka, ove promene su bile manje izražene. Hlebovi sa dodatkom jabuke i &scaron;ljive su ocenjeni kao najbolji po ukusu.</p> / <p>Osmotical dehydration in sugar beet molasses as hypertonic medium was used to treat apples, plums, carrots and red cabbage. Following the treatment, the fruits/vegetables were dried and ground. The study was aimed at determining the quality parameters of bread supplemented with the following ingredients: The freshly treated fruits/vegetables (at 10% and 30% level, flour basis), The powders derived from them (at 5% and 10% level flour basis), Sugar beet molasses (at 5% and 10% level flour basis).<br />The results showed that these ingredients significantly improved the mineral content of breads. The most marked was the increase in K content: for lower supplementation level, 89.1% (bread with<br />molasses)-94.1% (bread with plum, powder). For higher supplementation level, the rise in K content was 157.5% (bread with cabbage, powder) and 167, 5% (bread with molasses). Contents of Mg and Ca were also significantly increased as compared to the control. The highest increase in Mg and Ca was obtained by supplementation with cabbage at higher applied dose (around 58% and 100%, respectively). Moreover, the supplemented breads showed significantly higher antioxidant potentials with the highest increase measured in the breads made with plum (62.5-81.6% for 5 and 10% levels, respectively). The molasses-based ingredients influenced the physical, textural and sensory properties of bread by lowering the specific volume, increasing the crumb firmness and changing the color and flavor. However, the lower supplementation levels had relatively mild effect on these properties. The breads made with apples and plums were scored highest for flavor.</p>
78

Evaluation of Alternative Methods for Leafy Spurge Control in the Northern Great Plains

Ellig, Tracy Lynn January 2018 (has links)
Leafy spurge (Euphorbia esula L.) is a costly noxious weed to manage in the Northern Great Plains; it invades rangelands and displaces native and desirable vegetation. Our first objective was to test the recommended full rate and half rate of selected herbicides applied in September following a spring burn on a leafy spurge invaded plant community. Our second objective was to determine if raffinate (desugared beet molasses) applied to leafy spurge invaded rangeland would attract cattle to consume leafy spurge. The aminocyclopyrachlor with chlorosulfuron treatment had the best leafy spurge control at the full rate, with stem density reductions of 95 percent for both sites nine and twelve months after treatment. The salt block treatment had the best success at reducing leafy spurge stem density. Herbicides can be the most common and effective type of management; however, manipulating livestock to graze noxious weeds converts a weed into a useable forage.
79

Analysis of vortex movement in an YBCO thin film : Models of the vortex solid-to-liquid transition compared to a sensitive resistive measurement of a strongly pinned YBCO thin film

Ellgren, Alex January 2013 (has links)
When a high-temperature superconductor transitions in the presence of a magnetic field, the resistance does not immediately go to zero. Instead, the transition is smoothed by the resistive effects of moving vortices so that perfect conductivity isn't reached until several K below Tc, where the vortices have frozen into a glass state. The properties of this glass depend mainly on the amount and correlation between impurities in the superconductor. This report describes a study of the glass transition in an YBCO thin film rich in uncorrelated impurities. The aim was to use sensitive resistive measurements to determine which of two models of this transition, the vortex glass model and the vortex molasses model, is more accurate. After evaluation, both models are found lacking and a third model is put forth. This model, which resembles the normal distribution, excellently describes the YBCO thin film case. When the new model is tested against data from similar measurements, an YBCO single crystal and a TlBaCaCuO thin film, the results are mixed. Further study is suggested to determine the model's range of validity.
80

Evaluation of different process designs for biobutanol production from sugarcane molasses

Van der Merwe, Abraham Blignault 03 1900 (has links)
Thesis (MScEng (Process Engineering))--Stellenbosch University, 2010. / ENGLISH ABSTRACT: Recently, improved technologies have been developed for the biobutanol fermentation process: higher butanol concentrations and productivities are achieved during fermentation, and separation and purification techniques are less energy intensive. This may result in an economically viable process when compared to the petrochemical pathway for butanol production. The objective of this study is to develop process models to compare different possible process designs for biobutanol production from sugarcane molasses. Some of the best improved strains, which include Clostridium acetobutylicum PCSIR-10 and Clostridium beijerinckii BA101, produce total solvent concentrations of up to 24 g/L. Among the novel technologies for fermentation and downstream processing, fedbatch fermentation with in situ product recovery by gas-stripping, followed by either liquid-liquid extraction or adsorption, appears to be the most promising techniques for current industrial application. Incorporating these technologies into a biorefinery concept will contribute toward the development of an economically viable process. In this study three process routes are developed. The first two process routes incorporate well established industrial technologies: Process Route 1 consist of batch fermentation and steam stripping distillation, while in Process Route 2, some of the distillation columns is replaced with a liquid-liquid extraction column. The third process route incorporates fed-batch fermentation and gas-stripping, an unproven technology on industrial scale. Process modelling in ASPEN PLUS® and economic analyses in ASPEN Icarus® are performed to determine the economic feasibility of these biobutanol production process designs. Process Route 3 proved to be the only profitable design in current economic conditions. For the latter process, the first order estimate of the total project capital cost is $187 345 000.00 (IRR: 35.96%). Improved fermentation strains currently available are not sufficient to attain a profitable process design without implementation of advanced processing techniques. Gas stripping is shown to be the single most effective process step (of those evaluated in this study) which can be employed on an industrial scale to improve process economics of biobutanol production. / AFRIKAANSE OPSOMMING: Onlangse verbeteringe in die tegnologie vir die vervaardiging van butanol via die fermentasie roete het tot gevolg dat: hoër butanol konsentrasies en produktiwiteit verkry kan word tydens die fermentasie proses, en energie verbruik tydens skeiding-en suiweringsprosesse laer is. Hierdie verbeteringe kan daartoe lei dat biobutanol op ʼn ekonomiese vlak kan kompeteer met die petrochemiese vervaardigings proses vir butanol. Die doelwit van die studie is om proses modelle te ontwikkel waarmee verskillende proses ontwerpe vir die vervaardiging van biobutanol vanaf suikerriet melasse vergelyk kan word. Verbeterde fermentasie organismes, wat insluit Clostridium acetobutylicum PCSIR-10 en Clostridium beijerinckii BA101, het die vermoë om ABE konsentrasies so hoog as 24 g/L te produseer. Wat nuwe tegnologie vir fermentasie en skeidingprosesse behels, wil dit voorkom of wisselvoer fermentasie met gelyktydige verwydering van produkte deur gasstroping, gevolg deur of vloeistof-vloeistof ekstraksie of adsorpsie, van die mees belowende tegnieke is om tans in die nywerheid te implementeer. Deur hierdie tegnologie in ʼn bioraffinadery konsep te inkorporeer sal bydra tot die ontwikkeling van ʼn ekonomies lewensvatbare proses. Drie prosesserings roetes word in die studie ontwikkel. Die eerste twee maak gebruik van goed gevestigde industriële tegnologie: Proses Roete 1 implementeer enkellading fermentasie en stoom stroping distillasie, terwyl in Proses Roete 2 van die distilasiekolomme vervang word met ʼn vloeistof-vloeistof ekstraksiekolom. Die derde proses roete maak gebruik van wisselvoer fermentasie met gelyktydige verwydering van produkte deur gas stroping. Die tegnologie is nog nie in die nywerheid bewys of gevestig nie. Om die ekonomiese uitvoerbaarheid van die proses ontwerpe te bepaal word proses modellering uitgevoer in ASPEN PLUS® en ekonomiese analises in ASPEN Icarus® gedoen. Proses Roete 3 is die enigste ontwerp wat winsgewend is in huidige ekonomiese toestande. Die eerste orde koste beraming van die laasgenoemde projek se totale kapitale koste is $187 345 000.00 (opbrengskoers: 35.96%). Die verbeterde fermentasie organismes wat tans beskikbaar is, is nie voldoende om ʼn proses winsgewend te maak nie; gevorderde proses tegnologie moet geïmplementeer word. Gasstroping is bewys as die mees effektiewe proses stap (getoets in die studie) wat op industriële skaal geïmplementeer kan word om die winsgewendheid van die biobutanol proses te verbeter. / Centre for Renewable and Sustainable Energy Studies

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