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1
Brtníková, Jana. "Využití plynové chromatografie ke studiu permeace toxických látek bariérovými materiály." Doctoral thesis, Vysoké učení technické v Brně. Fakulta chemická, 2009. http://www.nusl.cz/ntk/nusl-233295.
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Transport phenomenon of gas and vapors through polymer barrier materials as well as the factors affecting permeability of gaseous and liquid toxic compounds were investigated and results are presented in this thesis. Permeation characteristics investigation methods were elaborated and verified with focusing on utilization of gas chromatographic method and its instrumental modifications.
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Dragana, Ilić-Udovičić. "Optimizacija tehnološkog procesa proizvodnje napitaka od enzimski hidrolizovanog permeata mleka." Phd thesis, Univerzitet u Novom Sadu, Tehnološki fakultet Novi Sad, 2015. http://www.cris.uns.ac.rs/record.jsf?recordId=95728&source=NDLTD&language=en.
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Valorizacija permeata kao sporednog proizvoda industrije mleka je od izuzetnog ekološkog, ekonomskog i tehnološkog značaja.Cilj doktorske disertacije je razvoj tehnološkog procesa prerade permeata, kao sporednog proizvoda dobijenog nakon ultrafiltracije mleka tokom proizvodnje feta sira i svežeg („mladog“) sira. Ispitana je mogućnost enzimske hidrolize laktoze u permeatu korišćenjem enzima β-galaktozidaze izolovanog iz Kluyveromyces lactis u koncentraciji 0,1, 0,3 i 0,5 g/100g na temperaturama 20º, 30º i 40 ºC. Praćene su promene sadržaja laktoze, D–galaktoze i D–glukoze u vremenskim intervalima tokom 60 minuta. Posebna faza istraživanja obuhvatila je matematičko modelovanje i kinetiku procesa hidrolize laktoze u permeatu pod dejstvom β –galaktozidaze i primenu hidrolizovanog permeata u proizvodnji mlečnih napitaka po odabranoj formulaciji. Predložen je tehnološki proces proizvodnje napitka na bazi hidrolizovanog permeata sa dodatkom voćnih baza. Utvrđeni su parametri kvaliteta i trajnosti napitaka tokom 60 dana skladištenja.Na temperaturi 40°C dodatkom enzima β -galaktozidaze u koncentraciji 0,1g/100g za 60 minuta postiže se 100% stepen hidrolize prisutne laktoze u permeatu. Sa većom koncentracijom enzima, 0,3 g/100g odnosno 0,5g/100g, na istoj temperaturi, isti efekat se postiže za 20 minuta.Ispitivanjem kinetike hidrolize laktoze potvrđena je kinetika prvog reda. Generalno posmatrano visoki koeficijenti determinacije pokazuju dobro poklapanje eksperimentalnih rezultata i matematičkog modela reakcije prvog reda. Vrednosti se kreću od 0,974 (temperatura 20°C) do preko 0,990 (na temperaturama 30°C i 40°C) pri koncentraciji enzima 0,1g/100g.Proizvedeni napici od hidrolizovanog permeata su delaktozirani i ne sadrže mlečnu mast. Od ukupnih šećera u svim napicima više od 50% čini glukoza: 50,16% - napitak šumsko voće, 50,42% - napitak pomorandža/šargarepa, 54,65% - napitak multivitamin, odnosno 55,13% - napitak crveno voće.Najveći sadržaj vitamina C nakon proizvodnje imao je napitak sa dodatkom voćne baze multivitamin 0,3972 mg/100g, zatim šumsko voće 0,2887 mg/100g i pomo-randža/šargarepa 0,1999 mg/100g.Najveću vrednost antioksidativne aktivnosti nakon proizvodnje pokazali su uzorci napitka sa multivitaminom i šumskim voćem. Tokom perioda skladištenja dolazi do smanjenja DPPH vrednosti. Najmanji pad je u napitku sa pomorandžom / šargarepom (smanjenje za 17%), a najveći u napitku sa šumskim voćem (za 39%). Analizirani uzorci sadrže ukupnih polifenola u intervalu od 47,84 do 120,38 mg GAE/l u zavisnosti od vrste napitka, odnosno dodatih voćnih baza.Generalno može se zaključiti da se prime-njenim tehnološkim procesom dobijaju napici stabilnog fizičko-hemijskog sastava tokom 60 dana skladištenja, visoke nutritivne i niske energetske vrednosti.Valuation of the permeate as a by-product of the dairy industry is of great ecological, economic and technological importance.The aim of the PhD thesis is the development of the technological process of refining permeate, as a by-product obtained after ultrafiltration of milk during the production of feta cheese and fresh cheese. The possibility of enzymatic hydrolysis of the lactose in the permeate using the enzyme β-galactosidase isolated from Kluyveromyces lactis in a concentration of 0.1, 0.3 and 0.5 g / 100 g at a temperature of 20°, 30° and 40° C was examined. Changes in the content of lactose, D-galactose and D-glucose at intervals of 60 minutes were monitored. A special stage of the research included mathematical modeling and kinetics of lactose hydrolysis in the permeate under the influence of β-galactosidase and application of hydrolyzed permeate in the production of dairy products under the selected formulation. A technological process of producing a beverage on the basis of hydrolyzed permeate with the addition of fruit bases was suggested. Quality and durability parameters were determined for drinks during the 60 days of storage.Addition of the enzyme β-galactosidase at a concentration of 0.1 g / 100 g for 60 minutes at a temperature of 40 ° C a 100% degree of hydrolysis of lactose is achieved, present in the permeate. With a higher concentration of enzyme, 0.3 g / 100 g or 0.5 g / 100g, at the same temperature, the same effect can be achieved in 20 minutes.By examining the kinetics of lactose hydrolysis the first order kinetics was confirmed. Generally high coefficients of determination show good correspondence between the experimental results and the mathematical model of the first order reaction. Values range from 0.974 (at a temperature of 20° C) up to over 0.990 (at temperatures 30° C and 40° C) at a an enzyme concentration of 0.1g / 100g.Beverages produced from hydrolyzed permeate are lactose-free and fat-free products. More than half of the total sugar content in all beverages consists of glucose: 50.16%-forest fruit beverage, 50.42%-beverage orange/carrot, 54.65% beverage multivitamin and 55.13% - beverage red fruit.The highest vitamin C content after production was in a beverage with the addition of fruit base multivitamin (0.3972 mg/100g), followed by forest fruit (0.2887 mg/100g) and orange/carrot (0.1999 mg/100g).Beverage samples with multivitamin and forest fruits showed the highest value of antioxidant activity after production. During the storage period there is a reduction of DPPH values. The smallest decrease was in the beverage with orange/carrot (decreased 17%), and the biggest in the beverage with forest fruit (39%). The content of polyphenols in analyzed samples ranges from 47.84 to 120.38 mg GAE/L depending on the type of beverage and added fruit base.Overall it can be concluded that the applied technological process gives beverages of stable physical and chemical content during the 60 days of storage, of high nutritional value and low energy.
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Santos, Barbara Belodi dos. "Utilização do permeado de leite como adjunto na produção de cerveja de alta fermentação (ALE)." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/97/97132/tde-06072016-145942/.
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O Brasil ocupa o 3º lugar entre os maiores produtores mundiais de cerveja e o mercado consumidor vem aumentando progressivamente. Tendo em vista que o consumidor brasileiro está em busca de novos sabores e aromas para a cerveja, uma alternativa para a redução de custos explorando tais características reside no uso de adjuntos não convencionais que possam agregar valor à bebida, principalmente na obtenção de boas características sensoriais. Ainda, visando à sustentabilidade, estes adjuntos podem ser coprodutos do processamento de alimentos. O permeado concentrado de leite, um coproduto dos laticínios, é obtido através da ultrafiltração do leite, sendo composto por água, lactose e sais. Neste trabalho foi desenvolvido um processo para a produção de uma cerveja de alta fermentação (ale), utilizando o permeado concentrado de leite como adjunto de fabricação. Foram obtidas cervejas ale com a proporção malte/permeado de 55/45 e 90/10, utilizando para isso, permeado hidrolisado pela enzima ?-galactosidase e permeado não hidrolisado. A caracterização do permeado revelou que este possui três vezes mais lactose que o soro de queijo. A melhor condição de hidrólise enzimática da lactose presente no permeado foi obtida empregando-se 2,0 mL/L de ?-galactosidase em 90 minutos, alcançando 92,5% de hidrólise. Nas cervejas com permeado hidrolisado observou-se que a presença de galactose aumentou o tempo de fermentação para 168h e a atenuação real de fermentação dos mostos também foi maior em comparação as cervejas com permeado não hidrolisado, nos quais a lactose não foi fermentada. As cervejas 90/10 com permeado hidrolisado e não hidrolisado receberam as maiores notas na análise sensorial, tendo boa aceitação entre os provadores. Como não houve diferença estatística entre as duas, foi possível reduzir custo e tempo na produção da cerveja 90/10 em escala piloto (120L) por não ser necessário o processo de hidrólise enzimática. O permeado concentrado de leite mostrou-se um excelente adjunto na produção de cervejas ale e quando empregado em baixa concentração, produziu cervejas com boa aceitação sensorial.Brazil ranks 3rd among the largest world producers of beer and the consumer market is increasing steadily. Considering that the Brazilian consumer is looking for new flavors and aromas to the beer, a possible solution for costs reduction exploring such characteristics is using unconventional adjuncts that can increase quality of the beverage, especially in getting good sensory characteristics. In addition, aiming at sustainability, such adjuncts can be coproducts of processing foods. The concentrated milk permeate, which is a dairy factory coproduct, is obtained by milk ultrafiltration, comprising water, lactose and salts. In this work it was development a process for the production of an ale beer using concentrated milk permeate as adjunct. Ale beers were obtained from the proportion malt/permeate 55/45 and 90/10, using both permeate hydrolyzed by ? - galactosidase enzyme and permeate not hydrolyzed. The characterization of the permeate revealed that it has three times more lactose than cheese whey. The best condition of enzymatic hydrolysis of lactose present in the permeate was obtained using 2.0 mL/L of ?-galactosidase within 90 minutes, reaching 92.5 % of hydrolysis. It was observed that the presence of galactose in beers wort with hydrolysed permeate increased fermentation time to 168 h and the real attenuation of fermentation were also higher compared with non-hydrolysed permeate beers, in which lactose is not fermented. The beers 90/10 with hydrolyzed and non-hydrolyzed permeate received the highest scores in sensory analysis, meaning a good acceptance among the tasters. Once there was no statistical difference between them, it was possible to reduce costs and time in beer 90/10 production on a pilot scale (120L) for not being necessary the enzymatic hydrolysis process. The concentrated milk permeate has proved to be an excellent adjunct in the production of ale beers. It produced ale beers with good sensory acceptance when used in low concentration.
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Fabricio, Mariana Fensterseifer. "Produção de ácidos graxos poli-insaturados pela levedura Meyerozyma Guilliermondii BI281a utilizando resíduos agro-industriais como substrato." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2018. http://hdl.handle.net/10183/180524.
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Leveduras oleaginosas possuem a capacidade de sintetizar grande quantidade de lipídeos em suas células, gerando produtos de alto valor agregado através de um processo sustentável. Um perfil de ácidos graxos poli-insaturados é de grande interesse por parte das industrias alimentícia e farmacêutica e têm sido alvo de diversos estudos em relação à sua produção e efeitos benéficos à saúde. O presente trabalho teve como objetivo produzir ácidos graxos poli-insaturados pela levedura Meyerozyma guilliermondii BI281 utilizando glicose, glicerol residual e permeado de soro de queijo como fontes de carbono. Avaliou-se o metabolismo da levedura em meios de cultivo com diferentes composições (“meio A” e “base YM”) e comparou-se o seu desempenho em razões C/N 100: 1 e 50:1. A levedura foi capaz de metabolizar todos os substratos testados e o meio de cultivo “A” com glicerol residual e razão C/N 50:1 mostrou-se o mais adequado, obtendo valores de 5,67 g.L-1 de biomassa e 1,04 g.L-1 de lipídeos, representando aproximadamente 18 % do peso da massa seca de biomassa. Esta condição foi escalonada para biorreator de 2 L, onde condições de aeração e controle de pH puderam ser avaliadas, apresentando quantidade semelhante de lipídeos (1,08 g.L-1) e uma maior produção de biomassa (7,05 g.L-1). Os ácidos graxos sintetizados apresentaram em sua composição ácido láurico (C12:0), ácido mistírico (C14:0), ácido palmítico (C16:0), ácido pamitoleico (C16:1), ácido esteárico (C18:0), ácido oleico (C18:1 n-9), ácido linoleico (C18:2 n-6) e ácido linolênico (C18:3 n-3).Oleaginous yeasts are able to synthesize high amounts of lipids in their cells, producing high added-value products through a sustainable process. Food and pharmaceutical companies have great interest in polyunsaturated fatty acids depending on their profiles and many studies related to their production and health benefits have been carried out. The aim of this study was to produce polyunsaturated fatty acids by the yeast Meyerozyma guilliermondii BI281A using glucose, crude glycerol, and cheese whey permeate as carbon sources. Yeast metabolism was evaluated in different compositions of culture media (“A” and “YM”) and at different C/N ratios (100:1 and 50:1). The yeast was able to assimilate all substrates tested, and medium “A” with crude glycerol as carbon source at a C/N ratio of 50:1 had the most efficient result with biomass production of 5.67 g.L-1 and lipid production of 1.08 g.L-1, which represented 18 % of dry cell weight. This composition was scaled-up to a 2 L bioreactor, where it was possible to measure pH and aeration conditions, and showed similar lipid production (1.08 g.L-1) and higher biomass production (7.05 g.L-1). Fatty acids profile obtained was composed by lauric acid (C12:0), myristic acid (C14:0), palmitic acid (C16:0), palmitoleic acid (C16:1), stearic acid (C18:0), oleic acid(C18:1), linoleic acid (C18:2 n-6), and linolenic acid (C18:3 n-3).
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Santos, Jordana Dorca dos. "Tratamento de efluente de fecularia utilizando coagulação/floculação e separação por membranas." Universidade Estadual do Oeste do Paraná, 2016. http://tede.unioeste.br/handle/tede/3064.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
This research aimed to study the treatment of manipueira by combined process of coagulation/flocculation and membrane separation, targeting the non-potable reuse this water. For pretreatment of the effluent triage was performed using five natural coagulants (Acquapol WW, and S5T Tanfloc POP, ST, SG), a chemical (Al2SO4) and a cationic flocculant (Zetag ® 8185).Experimental designs Plackett & Burman (PB12) followed by a full factorial 2k was used in order to obtain the best experimental conditions in the process. The supernatant obtained in step of coagulation/flocculation under went a process of separation of micro-and ultrafiltration membranes varying pressures (0,6, 1 and 1,4 bar), permeate flows being analyzed, fouling and removal efficiency.The raw sewage and water resulting from treatment in the best conditions of coagulation/flocculation and filtration, under went a toxicity test using brine shrimp body. From the selected sorting the sedimentation time 15 minutes and Tanfloc POP among the natural coagulants.The best condition of operation of the coagulation/flocculation obtained through experimental planning was 1 min to 10 min, TMR TML, 180 rpm for VMR and 10 rpm of VML, pH of 8.5 and coagulant concentration of 440 mg L-1, with removals of 88,5% to turbidity and 78,9% color. The model adjusted to the data in the color parameter removal complete factorial planning using coagulant Tanfloc POP. The tests of filtration (MF and UF) presented on pressure of 1,4 bar, above 95% removal of colour and turbidity, and above 60% for nitrogen and COT, but with lower COD removal (less than 70%). The toxicityof that treated wastewater (66% and 100%) reported toxic to the test organism due to the presence of free cyanide. The permeated obtained (MF) could be used for less noble purposes among the classes (2, 3 and 4) suggested by the ABNT NBR 13,696/1997. The results obtained in this study demonstrate the potential of C/F, MF and UF, for treatment of manipueira.
Esta pesquisa teve como objetivo estudar o tratamento da manipueira por processo combinado de coagulação/floculação e separação por membranas, visando o reuso não potável desta água. Para o pré-tratamento do efluente foi realizada uma triagem utilizando cinco coagulantes naturais (Acquapol WW, S5T e Tanfloc POP, ST, SG), um químico (Al2SO4) e um floculante catiônico (Zetag 8185®). Planejamentos experimentais Plackett & Burman (PB12) seguido de um fatorial completo 2k foram utilizados a fim de obter as melhores condições experimentais no processo. O sobrenadante obtido na etapa de coagulação/floculação foi submetido a um processo de separação por membranas de micro e ultrafiltração variando-se as pressões (0,6, 1 e 1,4 bar), sendo analisados os fluxos de permeado, fouling e eficiência de remoção. O efluente bruto e a água resultante do tratamento nas melhores condições dos ensaios de coagulação/floculação e filtração, foram submetidos a um ensaio de toxicidade utilizando o organismo Artemia salina. A partir da triagem selecionou-se o tempo de sedimentação de 15 minutos e o Tanfloc POP dentre os coagulantes naturais. A melhor condição de operação da coagulação/floculação obtida através dos planejamentos experimentais foi de 1 min para TMR, 10 min de TML, 180 rpm para VMR e 10 rpm de VML, pH de 8,5 e concentração do coagulante de 440 mg L-1, com remoções de 88,5% para cor e 78,9% de turbidez. O modelo ajustou-se aos dados de remoção do parâmetro cor no planejamento fatorial completo utilizando o coagulante Tanfloc POP. Os ensaios de filtração (MF e UF) apresentaram na pressão de 1,4 bar, remoções acima de 95% de cor e turbidez, e acima de 60% para nitrogênio e TOC, porém com baixa remoção de DQO (menor que 70%). A toxicidade, do efluente mesmo tratado (66% e 100%) apresentou-se tóxico para o organismo teste devido à presença de cianeto livre. O permeado obtido (MF) poderia ser utilizado para fins menos nobres dentre as classes (2, 3 e 4) sugeridas pela ABNT NBR 13.969/1997. Os resultados obtidos neste estudo demonstram o potencial dos processos de C/F, MF e UF, para tratamento da manipueira.
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Howell, John Michael. "Whey permeate fouling of evaporators." Thesis, University of Canterbury. Chemical and Process Engineering, 1998. http://hdl.handle.net/10092/10686.
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Whey permeate fouling was studied to gain a better understanding of the processes involved and find methods of alleviation. An apparatus was built which allowed study of fouling under industrial conditions. It was found that pretreatment by heating at 80°C for two minutes and then centrifuging at 630 g reduced fouling in the apparatus by 94%. This was attributed to precipitation of calcium phosphate in the solution bulk during preheating, which reduced the level of supersaturation. Heat treatment with the same conditions but without centrifuging reduced fouling by only 39%. Precipitate which forms in the bulk of solution fouls in later heat treatment processes and separation of the precipitated mineral is needed to minimise fouling.
Storage time affected fouling. In the short term (about 2 weeks), fouling slightly increased with storage time. When held for longer times (about 1 month) whey permeate did not appreciably foul.
The use of additives was also found to be an effective alleviation method, reducing fouling by 66% with 0.1% addition (by dry weight) of tetrasodium pyrophosphate. This addition would increase the price of a ton of lactose by $16.32 /ton.
Nanoftltration, ion dialysis and electrodialysis were also examined, but rejected as being uneconomic.
By observing the effect of preheating and storage time it was proposed that calcium phosphate exists in whey in two forms. The majority of the minerals are associated with non-protein nitrogen (NPN) species, which tends to provide stability and prevent precipitation. In the other form the calcium phosphate is in solution as free ions. When the NPN species release minerals due to cleavage by enzymes or denaturation by heat, the concentration of ionic species increases past the solubility product and precipitation occurs.
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Silva, Layane Priscila de Azevedo. "Utiliza??o de membranas no p?s-tratamento de esgotos para reuso do permeado e aproveitamento do concentrado." Universidade Federal do Rio Grande do Norte, 2014. http://repositorio.ufrn.br:8080/jspui/handle/123456789/16012.
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Previous issue date: 2014-02-28Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior
The use of membrane filters in the post-treatment of sewage has been increasingly employed to obtain water quality, applicable to various forms of reuse. Despite the advantages presented using the permeate membranes, such as saving water and reducing water pollution, the concentrate generated in the process ends up being an inconvenience to the deployment of this technology due to lack of sustainable solutions for their management. Thus, the main objective of this research was to evaluate the use of membranes for microfiltration, ultrafiltration, nanofiltration and reverse osmosis concentrated in agriculture, using it as liquid fertilizer. The permeated membranes were also assessed in order to identify activities in which they could be reused. Five configurations were established from four types of membranes, so that each configuration represents a different system. The tests were conducted in batch mode, with triplicate for each configuration. The results indicated that permeated the microfiltration and ultrafiltration can be used in urban areas, in non-potable uses. Have the nanofiltration permeate can be reused in the industry, replacement cooling towers, and other non -potable uses required in the manufacturing unit. The permeate obtained in reverse osmosis met the intended uses for nanofiltration as well as the standards required for boiler feed, adding alkalizing being required to raise the pH to the recommended value. Concentrates generated in nanofiltration and reverse osmosis can be availed as liquid fertilizer in agriculture, but they must be diluted in the irrigation water, in order to adjust the salt concentration allowed for the least tolerant crops patterns
A utiliza??o de membranas filtrantes no p?s-tratamento de esgotos tem sido cada vez mais empregada para obten??o de ?gua com qualidade, aplic?vel a v?rias modalidades de re?so. Apesar das vantagens apresentadas com o uso do permeado de membranas, como a economia de ?gua e a redu??o da polui??o h?drica, o concentrado gerado no processo acaba sendo um inconveniente para a implanta??o dessa tecnologia, devido ? falta de solu??es sustent?veis para seu gerenciamento. Sendo assim, o principal objetivo dessa pesquisa foi avaliar o uso do concentrado de membranas de microfiltra??o, ultrafiltra??o, nanofiltra??o e osmose inversa na agricultura, utilizando-o como adubo l?quido. Os permeados das membranas tamb?m foram avaliados, a fim de identificar em que atividades os mesmos poderiam ser reutilizados. Foram estabelecidas cinco configura??es, a partir dos quatro tipos de membranas, de modo que cada configura??o representou um sistema distinto. Os ensaios foram realizados em batelada, com triplicata para cada configura??o. Os resultados indicaram que os permeados da microfiltra??o e ultrafiltra??o podem ser utilizados no meio urbano, em usos n?o pot?veis. J? o permeado da nanofiltra??o pode ser reutilizado na ind?stria, para reposi??o em torres de resfriamento, e nos demais usos n?o pot?veis requeridos na unidade fabril. O permeado obtido no processo de osmose inversa atendeu aos usos previstos para nanofiltra??o, bem como aos padr?es exigidos para alimenta??o de caldeiras, sendo necess?ria a adi??o de alcalinizante, para elevar o pH at? o valor recomendado. Os concentrados gerados na nanofiltra??o e osmose inversa podem ser aproveitados na agricultura como adubo l?quido, mas precisam ser dilu?dos na ?gua de irriga??o, a fim de adequar a concentra??o de sais aos padr?es permitidos para culturas menos tolerantes
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Neil, Teresa Kathleen. "Structural studies of oligopetide permease A." Thesis, University of York, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.306526.
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Dixon, Elizabeth Marie. "Whey Permeate, Delactosed Permeate, and Delactosed Whey as Ingredients to Lower Sodium Content of Cream Based Soups." NCSU, 2008. http://www.lib.ncsu.edu/theses/available/etd-11072008-113327/.
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The use of whey permeates as salt substitutes can help to decrease sodium and chloride intake, increase potassium, calcium and magnesium intakes and decrease hypertension risk. Five different whey permeates from 5 different manufacturers were analyzed with ICP for mineral content (Na, K, Ca, Mg, Fe, Zn). Two permeates are powder and three are liquid. Lactose and protein content were also analyzed by Lactose/D-Glucose UV kit from Roche and BCA protein assay, respectively. Chloride and phosphate were measured spectrophotometrically. Basic tastes and aromas were quantified by a trained sensory panel. Based on the highest âsalty tasteâ identified by the trained sensory panel, one liquid and one solid permeate were further investigated as sodium substitutes. The sodium content of the guideline solutions for comparing salty taste of the permeates were used to calculate the equivalent concentrations of salt and permeate for salty taste in aqueous solution. Two soup formulations were used to test the use of permeate as a salt substitute; one retorted, canned, condensed cream soup base, and one fresh cream soup base. Each formulation of soup was tested on a separate day by 75 consumer panelists who averaged between 20 and 30 years of age. Four samples were given each day 0%, 50%, 100% of the standard salt content in condensed soup, and permeate at a content calculated to be equal in salty taste to the standard salt content. The permeate soup was ranked in salty taste slightly lower than the 50% sample for the fresh soup. In the retorted soups, the permeate was ranked slightly higher than the 50% sample. However, the fresh and retorted soup formulations made from permeate actually contained 11% and 19% sodium as compared to the 100% salt recipe, respectively. The permeate soup was described as higher in salty taste than expected based on actual sodium content, but not as high as predicted from the salty taste of the permeate in aqueous solution. Potassium and magnesium levels were increased in the formulations with permeate. This research gives an optimistic view on the possibility of whey permeates and their capability of replacing sodium in cream soups and other processed foods.
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Downes, David. "Interactive models of electrical machines." Thesis, Nottingham Trent University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.273777.
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Bastian, Eric Douglas. "Ultrafiltration: Retentate-Permeate Partititioning of Milk Constituents." DigitalCommons@USU, 1987. https://digitalcommons.usu.edu/etd/5335.
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The effect of ultrafiltration, diafiltration, and preacidification of milk on the partition of specific milk components between retentate and permeate was studied. Percent retention (for any component Y) was determined as:
[ l - (%Y in soln. permeate/%Y in soln. retentate)] X 100 where %Y in soln. = [%Y/(%Y + %H 20)]
Simultaneous samples of retentate and permeate were taken at several points during each process. Percent retention of total solids, fat, total protein, rennet clottable nitrogen, lactose, total calcium, ionic calcium, sodium, phosphorous, and riboflavin was determined at each sampling point. Percent retention of β-carotene, vitamin B12, retinol, and zinc was determined at different stages of ultrafiltration only.
As UF proceeded, percent retention of total solids, total protein, total calcium, ionic calcium, sodium, phosphorous, and riboflavin increased. Percent retention of lactose was not affected and was 0-4%. Percent retention of fat, rennet clottable nitrogen, zinc, retinal, β-carotene, and vitamin B12 was 99-100%. As diafiltration proceeded, percent retention of total solids, lactose, total calcium, ionic calcium, sodium, phosphorous, and riboflavin increased. Percent retention of these nutrients was increased when compared to ultrafiltration alone.
Milks with lower pH values (resulting from preacidification) also had lower percent retention of total calcium and phosphorous than milks with normal pH values. Percent retention of sodium was lower during ultrafiltration and diafiltration of acidified milk when compared to ultrafiltration and diafiltration of normal milk. Percent retention of other nutrients was not affected by acidification.
Loss of whey proteins into permeate resulted in a lower recovery of total protein after diafiltration than ultrafiltration alone and ultrafiltration of acidified milk. These proteins were determined to be α-lactogobulin and β-lactogobulin.
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Hedlöf, Ekvall Linnea. "Faktorer för effektiv infiltration av dagvatten hos permeabel asfalt." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-381159.
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För att permeabel asfalt skall vara ett bra sätt att ta hand om dagvatten i en stad med allt fler hårdgjorda ytor är det viktigt att den långsiktigt kan infiltrera dagvatten. Då det inte går att undvika att permeabel asfalt utsätts för små partiklar finns det en risk för att den skall sätta igen och förlora sin förmåga att infiltrera dagvatten. Som en skötselåtgärd för att förhindra att den sätter igen kan rengöring med högtryckstvätt och vakuumsugning göras. I detta examensarbete undersöktes det vilken effekt rengöring med högtryckstvätt och vakuumsugning har på permeabel asfalts infiltrationskapacitet. Vidare undersöktes även vilken typ av uppbyggnad av den permeabla asfalten som var mest lämplig för en effektiv infiltration. Litteraturstudie och intervjuer om permeabel asfalt samt infiltrationsförsök har utförts. För att uppbyggnaden av permeabel asfalt hydrologiskt sett skall fungera på ett bra sätt framkom det, i litteraturstudier och intervjuer, att det är viktigt att alla lager i uppbyggnaden verkligen är permeabla och att uppbyggnaden bör anpassas efter rådande förhållanden på anläggningsplatsen. Förhållanden som till exempel bör tas hänsyn till är underliggande jordart och närheten till grundvattenyta. I litteraturstudier och intervjuer framkom det att regelbunden skötsel av den permeabla asfalten är mycket viktig för dess långtidsfunktion att kunna infiltrera dagvatten. Infiltrationsförsöken skedde på två platser med permeabel asfalt i Uppsala; på en parkering vid ett köpcentrum i Gnista och på en lokalgata i Gränby backe. Infiltrationskapaciteten uppmättes innan och efter rengöring med högtryckstvätt och vakuumsugning på den permeabla asfalten. Vid Gnista kunde ingen infiltration uppmätas varken före eller efter rengöring. I Gränby backe ökade infiltrationskapaciteten från 0,47–0,71 mm/min till 1,24–12,23 mm/min efter rengöring. Denna infiltrationskapacitet visar på att den permeabla asfalten i Gränby backe kunde infiltrera dimensionerade regn med allt från 7 års återkomsttid till över 1000 års återkomsttid och med 10 minuters varaktighet. Det framkom i litteraturstudien att högtryckstvätt och vakuumsugning i olika studier har haft en positiv effekt på att upprätthålla och till viss del återskapa infiltrationskapaciteten hos permeabel asfalt. Vid infiltrationsförsöken i detta examensarbete påvisades även en positiv effekt, till viss del, av denna rengöringsmetod på infiltrationskapaciteten. Utifrån detta skulle rengöring med högtryckstvätt och vakuumsugning kunna rekommenderas som skötselmetod på permeabel asfalt. Resultaten i Gnista skiljde sig från de i Gränby backe då det i Gnista varken före eller efter rengöring fanns någon infiltrationskapacitet. Det skiljer sig endast ett år i ålder mellan de båda försöksplatserna, de har skötts på liknande sätt sedan anläggning och litteratur visar på att rengöring med högtryckstvätt och vakuumsugning skall ha en effekt på infiltrationskapaciteten. Detta kan tyda på att bristen på infiltrationsförmåga i Gnista kan bero på något annat än igensättning av den permeabla asfalten.It is important that permeable asphalt is able to infiltrate storm water in the long-term for it to be a viable alternative for handling storm water. Permeable asphalt will always, in some way, be exposed to fine particles and therefore there is a risk that clogging will occur and that the permeable asphalt will lose its ability to infiltrate storm water. As a mean of maintenance cleaning with high pressure washing and vacuum cleaning can be done to prevent clogging. In this master thesis the effect of high pressure washing and vacuum cleaning on the infiltration capacity of permeable asphalt was examined. Also, the most suitable type of substructure for effective infiltration was examined. A literature study and interviews were conducted in combination with infiltration experiments on two locations with permeable asphalt in Uppsala. Literature studies and interviews state that for the substructure to be hydrologically well functioning it is important that every layer in the substructure really is permeable. The substructure should also be adapted to the conditions at the site where it is built. For example, conditions to take into consideration are soil type and highest level of groundwater. All through literature and interviews regular maintenance is said to be very important for the long-term functioning and infiltration of permeable asphalt. The infiltration experiments were conducted at a parking lot at a shopping center in Gnista and a small local street in Gränby backe. The infiltration capacity of the permeable asphalt was measured before and after maintenance with high pressure washing and vacuum suction. No infiltration capacity could be measured before or after maintenance at Gnista. In Gränby backe the infiltration capacity was 0,47-0,71 mm/min before maintenance and 1,24-12,23 mm/min after. According to this infiltration capacity the permeable asphalt in Gränby backe can infiltrate design rains with return periods of 7 years to over 1000 years and with a duration of 10 minutes. In research, high pressure washing, and vacuum suction were found to be able to maintain, and in some cases restore, infiltration capacity. In this master thesis’ infiltration experiments a positive effect on infiltration capacity by cleaning with high pressure washing and vacuum suction was partially found. According to this high pressure washing and vacuum suction can be recommended as a maintenance method on permeable pavement. The results from the two experiment sites stood apart from each other as Gnista had no infiltration capacity neither before nor after cleaning. In age, the two sites only differ by one year, and since they were built they have received similar maintenance and literature shows that high pressure washing and vacuums suction have an effect on infiltration capacity. This might indicate that the lack of infiltration capacity at Gnista might be due to something else than clogging.
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De, Ugarte Berthoumieux Maria Alicia. "Characterisation of the oligopeptide permease of Escherichia coli." Thesis, Bangor University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.245170.
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Harper, G. "The structure and permeance of coatings on fruit." Thesis, University of Cambridge, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383110.
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Olson, Amie L. "Efficacy of a whey permeate based sports drink." Online version, 2003. http://www.uwstout.edu/lib/thesis/2003/2003olsona.pdf.
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Chen, Esther J. (Esther Jean) 1973. "Regulation of GAP1 permease sorting in Saccharomyces cerevisiae." Thesis, Massachusetts Institute of Technology, 2003. http://hdl.handle.net/1721.1/29367.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Biology, 2003.Includes bibliographical references.
The intracellular sorting of the general amino acid permease (Gaplp) of Saccharomyces cerevisiae is regulated by the nitrogen source in the growth medium. During growth on a non-preferred nitrogen source or during nitrogen starvation, Gaplp is sorted to the plasma membrane, where it is active and can transport amino acids into the cell. During growth on a preferred or intermediate nitrogen source, Gap p is sorted to the vacuole and degraded. To better understand the signals governing Gaplp sorting, we isolated mutants with defects in Gaplp sorting during growth on a non-preferred nitrogen source. We found that genes that regulate the glutamate and glutamine biosynthesis pathways have a pronounced effect on the intracellular sorting of Gaplp. Mutations in the genes encoding the principal enzymes for glutamate and glutamine synthesis, GDH1 and GLN1, decreased intracellular levels of glutamate and glutamine, respectively, and increased delivery of Gap Ip to the plasma membrane. In contrast, deletion of the MKS] gene, which encodes a negative regulator of glutamate synthesis, increased glutamate and glutamine levels and increased sorting of Gaplp to the vacuole. We also found that the LST8 gene, which was previously implicated in the regulation of Gap lp sorting, encodes a positively-acting component of the TOR signaling pathway. Because the TOR pathway inhibits glutamate and glutamine biosynthesis, lst8 mutants accumulated high levels of these amino acids and showed increased Gaplp sorting to the vacuole. Likewise, wild-type cells grown with a sublethal concentration of rapamycin showed increased glutamate and glutamine levels and increased Gaplp sorting to the vacuole.
(cont.) Glutamate and glutamine were not unusual in their ability to affect Gaplp sorting, since all natural amino acids and many amino acid analogs, regardless of their utility as nitrogen sources, also triggered sorting of Gaplp to the vacuole. Finally, we found that many individual amino acids were toxic to mutants that sorted Gaplp constitutively to the plasma membrane. Together, these results indicate that amino acids are a signal for sorting Gaplp to the vacuole and suggest that the sensitivity of Gaplp sorting to amino acids represents a mechanism to protect yeast from an intracellular amino acid imbalance.
by Esther J. Chen.
Ph.D.
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Trichez, Débora. "Análise estrutural da permease Agt1p de Saccharomyces cerevisiae." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/87/87131/tde-24092012-084112/.
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Em S. cerevisiae, as proteínas de membrana são responsáveis pelo transporte de açúcares através da membrana celular e, portanto, são importantes para os processos fermentativos. Visando melhorar a compreensão do metabolismo de açúcares, estudamos o transporte ativo de açúcares mediado pela permease Agt1p e o processo de inativação catabólica, promovido pela glicose. Para isso, mutantes em resíduos específicos do Agt1p foram gerados por mutagênese e expressados em uma linhagem agt1D. Os resultados obtidos indicam que os aminoácidos Glu-120, Asp-123, Glu-167, Arg-504 e Ile-505 estão envolvidos com o simporte açúcar-H+ realizado pelo Agt1p. Em relação aos resíduos e/ou domínios envolvidos com o processo de inativação catabólica, os resultados demonstram que a região N-terminal do Agt1p, bem como a alça citoplasmática presente entre os TMs 6 e 7, são essenciais para a resposta celular frente a presença de glicose. Finalmente, a fusão do Agt1p com GST permitiu purificar uma proteína de ~67 kDa, condizente com a massa molecular prevista para este transportador.In S. cerevisiae, membrane proteins are responsible for the transport of different sugars across the cellular membrane and, therefore, are important for fermentation processes. In order to improve our understanding of sugar metabolism, we studied the active sugar transport mediated by Agt1p permease and the catabolite inactivation induced by glucose. Thus, mutants in specific residues of the Agt1p were generated by site direct mutagenesis and expressed in a strain agt1D. The results indicate that the Glu-120, Asp-123, Glu-167, Arg-504 and Ile-505 residues are involved in the sugar-H+ symport mediated by the Agt1p permease. Regarding residues and/or domains involved in the process of catabolite inactivation promoted by glucose, the results indicate that the N-terminal region of Agt1p, and the intracellular loop between TMs 6 and 7, are essential for the cellular response to the presence of glucose. Finally, the fusion of the Agt1p to GST allowed the purification of a ~67 kDa protein, consistent with the predicted molecular weight of this transporter.
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Sazama, Matt. "The effect of vapor permeable versus non-vapor permeable shirts on heat stress." Online version, 2001. http://www.uwstout.edu/lib/thesis/2001/2001sazamam.pdf.
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Ravi, Madapusi Vidhya. "Structure and dynamics of a membrane symporter: The Melibiose Permease." Doctoral thesis, Universitat Autònoma de Barcelona, 2016. http://hdl.handle.net/10803/370110.
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L’objectiu principal d’aquesta tesi doctoral ha estat estudiar el mecanisme de simport de la permeasa de melibiosa, MelB, un transportador secundari d’Escherichia coli, utilitzant mètodes experimentals (fluorescència, infraroig, assajos de transport) i computacionals (simulacions de dinàmica molecular). La MelB és un exemple de transportador versàtil, que pot utilitzar tant protons, com ions sodi o liti per a transportar una varietat de sucres α i β galactòsids. La MelB és una proteïna de 473 aminoàcids estructurats en forma de 12 hèlix transmembrana amb un 70% de residus hidrofòbics. Alguns estudis anteriors han demostrat que els bucles citoplasmàtics de la proteïna són importants per a la seva funció. Per tal d’avaluar la importància dels bucles perimplasmàtics, en el present treball hem analitzat el paper del bucle perimplasmàtic 5-6 (ric en glicines), juntament amb el paper d’uns pocs residus als extrems de les dues hèlix que connecta el bucle, la V i al VI, per mutagènesi dirigida.
Els experiments de fluorescència (FRET) i d’infraroig (FTIR) han demostrat que les mutacions puntuals produeixen un efecte intermedi (50%) en la unió de substrats al transportador, exceptuant (i) els mutants Asp35 i Arg175/Asp35, que no uneixen substrat i (ii) els mutants Asn168 (bucle 5-6) i Phe177 (hèlix VI), que afecten en un grau elevat (més del 50%) la unió dels substrats.
L’aproximació computacional ha permès concloure que alguns residus, com la Leu164 (hèlix V), l’Asn168 i la Phe177 juguen un paper important en el manteniment de la forma parcialment oclosa, interaccionant amb la meitat C-terminal de la proteïna. A més també s’han analitzat el paper de les interaccions iòniques. La informació obtinguda dels estudis de dinàmica molecular s’ha enriquit a partir de la troballa i descripció, per primera vegada, d’una forma de la proteïna oberta a l’exterior, resultat d’una trajectòria de 250 ns a partir de l’estructura cristal·logràfica.
Els resultats indiquen que els residus Asp35, Asn168 i Phe177 tenen un paper important en el mecanisme de transport de la permeasa de melibiosa d’E. Coli.The main aim of this doctoral thesis was to study the symport mechanism of the secondary transporter, melibiose permease (MelB) from Escherichia coli using experimental (Fluorescence, Infrared and transport assays) and computational (Molecular dynamics simulation) methods. This prokaryotic transporter is a versatile example of a cation-substrate cotransport carrier. A remarkable feature of this carrier is that, it uses different cations such as proton, Na+ or Li+ to transport variety of - and - galactosides. MelB is a protein of 473 amino acids arranged in 12 transmembrane helices with 70% of hydrophobic residues. Previous studies have shown the importance of cytoplasmic loops in MelB. Thus, in this study we analyzed the role of glycine rich periplasmic loop 5-6 along with few residues at the end and beginning of Helix V/VI, Asp-35 in Helix I by cysteine mutagenesis. Fluorescence (FRET) and infrared (FTIR) difference spectroscopy experiments have shown that the generated point mutations resulted in an intermediate (50%) effect on substrate binding, except for (i) the mutants Asp-35 and Arg-175/Asp-35, which did not exhibit any substrate binding, (ii) the mutants Asn-168 (loop 5-6) and Phe-177 (Helix VI), which had a high effect on substrate binding. The computational approach has pointed out that some of the residues, such as Leu-164 (Helix V), Asn-168, and Phe-177 play a significant role in maintaining the outward partially occluded conformation of MelB by interacting with the other half of the transmembrane helices, the C-terminal helical bundle. Furthermore, we also analyzed the role of ionic lock residues in MelB. The information derived from the molecular dynamics analysis has taken advantage of the description, for the first time, of an outward-open structure resulting from the crystallographic structure in a 250 ns trajectory. The results indicate that residues Asp-35, Asn-168 and Phe-177 have an important structural role in the transport mechanism of MelB.
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Nadai, Barbara Lepretti de. "Efeito da suplementação de nutrientes e da concentração de permeado de soro de leite no crescimento de Saccharomyces boulardii em sistema descontínuo." Universidade Estadual do Oeste do Parana, 2015. http://tede.unioeste.br:8080/tede/handle/tede/1858.
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Whey is considered one of the most polluting waste from the food industry, and its treatment a highly expensive process. An alternative for its reuse is applied to obtain biotechnological products. The objective of this study was to optimize the cell biomass production conditions of S. boulardii yeast in a batch system, using whey permeate. An experimental design was applied DCCR (a central composite design), and in response to cellular biomass, in order to evaluate the effect of four variables on cell biomass response. Fermentations were carried out at different pH, ammonium sulfate concentrations, and permeate. Two experiments with aeration to the fermentation medium were performed, aiming to increase the production of cell biomass. The highest cell biomass obtained in DCCR was 40,06 gL-1, under the following conditions: 7,5 gL-1 of ammonium sulfate, 1,25 gL-1 of magnesium sulfate, 1,5 gL-1 of monobasic potassium phosphate and 180 gL-1 of permeate, 30°C, agitation 100 rpm and pH 5,5. The investigated pH that favored the production of cell biomass was 4,5. The permeate concentrations which favored the production of biomass are included in the range of 180 to 220 gL-1. Thus, the study demonstrated that the whey permeate is a residue having great potential in producing cellular biomass using the yeast S. boulardii, showing how to dispose of this alternative, reducing negative impacts on the environment and decreasing costs for wastewater treatment industries.
O soro do leite é considerado um dos resíduos mais poluentes da indústria alimentícia, sendo seu tratamento um processo altamente dispendioso. Uma alternativa para a sua reutilização é a aplicação para a obtenção de produtos biotecnológicos. O objetivo deste trabalho foi otimizar as condições de produção de biomassa celular da levedura S. boulardii em sistema descontínuo, utilizando permeado de soro de leite. Foi aplicado um planejamento experimental DCCR (delineamento composto central rotacional), tendo como resposta a biomassa celular, com o intuito de avaliar o efeito de quatro variáveis sobre a resposta de biomassa celular. Foram realizadas fermentações com diferentes valores de pH, concentrações de sulfato de amônio e permeado. Foram realizadas dois ensaios com aeração ao meio fermentativo, objetivando o aumento na produção de biomassa celular. O maior valor de biomassa celular obtido no DCCR foi de 40,06 gL-1, sob as seguintes condições: 7,5 gL-1 de sulfato de amônio, 1,25 gL-1 de sulfato de magnésio, 1,5 gL-1 de fosfato monobásico de potássio e 180 gL-1 de permeado, 30ºC, agitação de 100 rpm e pH 5,5. O valor de pH investigado que favoreceu a produção de biomassa celular foi 4,5. As concentrações de permeado que favoreceram a produção de biomassa estão compreendidas na faixa de 180 à 220 gL-1. Assim, o estudo demonstrou que o permeado de soro de leite é um resíduo com grande potencial na produção de biomassa celular utilizando a levedura S. boulardii, mostrando-se como alternativa ao descarte deste, reduzindo os impactos negativos ao meio ambiente e diminuindo os custos de tratamento deste efluente para as indústrias.
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Côté, Annie 1975. "Ethanol production from an acid hydrolysed concentrated whey permeate." Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=79223.
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This work focused on assessing the feasibility of using an acid hydrolysed whey permeate for ethanol production from the yeast Saccharomyces cerevisiae.Various temperatures, acid types and concentrations for lactose hydrolysis were studied. The use of pressurised CO2 was also investigated. For all conditions studied using mineral acids, the glucose produced was less than the stoichiometric amount. During the hydrolysis using CO2, both glucose and galactose were consumed in side reactions. These results were explained. A linear model was developed, and satisfactorily described the rate of lactose hydrolysis for all acid types tested.
The fermentability of the hydrolysates produced was assessed in shake flasks using the yeast Saccharomyces cerevisiae. For three hydrolysis conditions, complete consumption of the hexoses present occurred. The hydrolysates produced at low acid concentrations and temperatures and with a higher initial pH were more readily fermented. Increasing the number of transfers decreased the negative effect of a high temperature of hydrolysis, but not the effect of a high acid concentration.
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Dodds, Ian. "Bacterial activity in permeable beds." Thesis, University of Exeter, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.267222.
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Alyanak, Didem Balköse Devrim. "Water vapour permeable edible membranes/." [s.l.]: [s.n.], 2005. http://library.iyte.edu.tr/tezler/master/biyoteknoloji/T000420.pdf.
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Kaschura, Felix, Axel Fischer, Daniel Kasemann, and Karl Leo. "Ambipolar organic permeable base transistors." SPIE, 2015. https://tud.qucosa.de/id/qucosa%3A35191.
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Organic transistors with vertical current transport like the Permeable Base Transistor (PBT) show a high performance while allowing for an easy fabrication on the device level. For a simple implementation on a circuit level, ambipolar transistors, providing the functionality of n-type as well as p-type devices, have a benefit for complementary logic. This requires transistors where electrons and holes are present. Here, we investigate a potential concept of bipolar current transport in PBTs. In our device structure, we use the base electrode to control the current flow, but also to investigate the charge carrier transport. The ambipolar organic PBT achieves a charge carrier transmission of 88% and a current density above 200mA=cm². Additionally, we show that recombination near the base is required in an ambipolar PBT for a good performance.
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Kaschura, Felix. "The Organic Permeable Base Transistor:." Doctoral thesis, Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-229432.
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Organic transistors are a core component for basically all relevant types of fully organic circuits and consumer electronics. The Organic Permeable Base Transistor (OPBT) is a transistor with a sandwich geometry like in Organic Light Emitting Diodes (OLEDs) and has a vertical current transport. Therefore, it combines simple fabrication with high performance due its short transit paths and has a fairly good chance of being used in new organic electronics applications that have to fall back to silicon transistors up to now. A detailed understanding of the operation mechanism that allows a targeted engineering without trial-and-error is required and there is a need for universal optimization techniques which require as little effort as possible. Several mechanisms that explain certain aspects of the operation are proposed in literature, but a comprehensive study that covers all transistor regimes in detail is not found. High performances have been reported for organic transistors which are, however, usually limited to certain materials. E. g., n-type C60 OPBTs are presented with excellent performance, but an adequate p-type OPBT is missing. In this thesis, the OPBT is investigated under two aspects: Firstly, drift-diffusion simulations of the OPBT are evaluated. By comparing the results from different geometry parameters, conclusions about the detailed operation mechanism can be drawn. It is discussed where charge carriers flow in the device and which parameters affect the performance. In particular, the charge carrier transmission through the permeable base layer relies on small openings. Contrary to an intuitive view, however, the size of these openings does not limit the device performance. Secondly, p-type OPBTs using pentacene as the organic semiconductor are fabricated and characterized with the aim to catch up with the performance of the n-type OPBTs. It is shown how an additional seed-layer can improve the performance by changing the morphology, how leakage currents can be defeated, and how parameters like the layer thickness should be chosen. With the combination of all presented optimization strategies, pentacene OPBTs are built that show a current density above 1000 mA/cm^2 and a current gain of 100. This makes the OPBT useful for a variety of applications, and also complementary logic circuits are possible now. The discussed optimization strategies can be extended and used as a starting point for further enhancements. Together with the deep understanding obtained from the simulations, purposeful modifications can be studied that have a great potentialOrganische Transistoren stellen eine Kernkomponente für praktisch jede Art von organischen Schaltungen und Elektronikgeräten dar. Der “Organic Permeable Base Transistor” (OPBT, dt.: Organischer Transistor mit durchlässiger Basis) ist ein Transistor mit einem Schichtaufbau wie in organischen Leuchtdioden (OLEDs) und weist einen vertikalen Stromfluss auf. Somit wird eine einfache Herstellung mit gutem Verhalten und Leistungsfähigkeit kombiniert, welche aus den kurzen Weglängen der Ladungsträger resultiert. Damit ist der OPBT bestens für neuartige organische Elektronik geeignet, wofür andernfalls auf Siliziumtransistoren zurückgegriffen werden müsste. Notwendig sind ein tiefgehendes Verständnis der Funktionsweise, welches ein zielgerichtetes Entwickeln der Technologie ohne zahlreiche Fehlversuche ermöglicht, sowie universell einsetzbare und leicht anwendbare Optimierungsstrategien. In der Literatur werden einige Mechanismen vorgeschlagen, die Teile der Funktionsweise betrachten, aber eine umfassende Untersuchung, die alle Arbeitsbereiche des Transistors abdeckt, findet sich derzeit noch nicht. Ebenso gibt es einige Veröffentlichungen, die Transistoren mit hervorragender Leistungsfähigkeit zeigen, aber meist nur mit Materialien für einen Ladungsträgertyp erzielt werden. So gibt es z.B. n-typ OPBTs auf Basis von C60, für die bisher vergleichbare p-typ OPBTs fehlen. In dieser Arbeit werden daher die folgenden beiden Aspekte des OPBT untersucht: Einerseits werden Drift-Diffusions-Simulationen von OPBTs untersucht und ausgewertet. Kennlinien und Ergebnisse von Transistoren aus verschiedenen Parametervariationen können verglichen werden und erlauben damit Rückschlüsse auf verschiedenste Aspekte der Funktionsweise. Der Fluss der Ladungsträger sowie für die Leistungsfähigkeit wichtige Parameter werden besprochen. Insbesondere sind für die Transmission von Ladungsträgern durch die Basisschicht kleine Öffnungen in dieser nötig. Die Größe dieser Öffnungen stellt jedoch entgegen einer intuitiven Vorstellung keine Begrenzung für die erreichbaren Ströme dar. Andererseits werden p-typ OPBTs auf Basis des organischen Halbleiters Pentacen hergestellt und charakterisiert. Das Ziel ist hierbei die Leistungsfähigkeit an die n-typ OPBTs anzugleichen. In dieser Arbeit wird gezeigt, wie durch eine zusätzliche Schicht die Morphologie und die Transmission verbessert werden kann, wie Leckströme reduziert werden können und welche Parameter bei der Optimierung besondere Beachtung finden sollten. Mit all den Optimierungen zusammen können Pentacen OPBTs hergestellt werden, die Stromdichten über 1000 mA/cm^2 und eine Stromverstärkung über 100 aufweisen. Damit kann der OPBT für eine Vielzahl von Anwendungen eingesetzt werden, unter anderem auch in Logik-Schaltungen zusammen mit n-typ OPBTs. Die besprochenen Optimierungen können weiterentwickelt werden und somit als Startpunkt für anschließende Verbesserungen dienen. In Verbindung mit erlangten Verständnis aus den Simulationsergebnissen können somit aussichtsreiche Veränderungen an der Struktur des OPBTs zielgerichtet eingeführt werden
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Costa, Ricardo Calvo. "Obtenção de lactose a partir de permeado de soro de queijo e permeado de leite." [s.n.], 1995. http://repositorio.unicamp.br/jspui/handle/REPOSIP/255587.
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Orientador: Salvador M. RoigDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: Neste trabalho foi estudada a extração de lactose a partir de permeado de leite e de permeado de soro de queijo, obtidos por ultrafiltração de leite e soro de queijo. A antecipação da etapa de descoloração foi estudada com o objetivo de eliminar a etapa de refino no processo tradicional e obter uma lactose de alto teor de pureza. A pasta descorante composta de 750/0 de carvão ativo e negro de ossos e 25% de ácido clorídrico concentrado foi adicionada aos permeados de leite e de soro de queijo, e somente resultou em descoloração quando foram utilizados teores de pasta superiores a 8% da massa de lactose presente no permeado. Os melhores resultados foram obtidos a partir de permeado de leite, obtido através de ultrafiltração de leite em um sistema de ultrafiltração dotado de membranas minerais, sem descoloracão do permeado. Os compostos coloridos foram retidos durante o processo de ultrafiltração resultando em um permeado límpido. O melhor processo obtido para extração de lactose a partir de permeado foi ultrafiltração do leite em membrana mineral, seguido de concentração à vácuo do permeado, cristalização, separação, lavagem dos cristais com água a 5°e e secagem. A partir de permeado de leite com 0,027% de nitrogênio total 0,49% de cinzas e 4,71 % de lactose foi obtida lactose com 99,3% de pureza 0,66% de cinzas e 0,07% de nitrogênio total
Abstract: The lactose extraction by ultrafiltration from milk and whey permeates was studied. The aim of this work was to eliminate the refining step of the traditional process and produce a high purity level lactose yield before the discolouring step. The discolouring paste which is made of 75% of a mixture of active carbon and black bone and 25% of concentrated hydrogen chloride was added to milk and whey permeates resulting in discolouring only when the paste concentration was higher than 8% in relation to the lactose mass in the permeate. The best results carne from milk permeate processed in a mineral membranes milk ultrafiltration system without the discolouring step. The colouring compounds were retained in the ultrafiltration process resulting in a cleaned permeate. The best process to lactose extraction from permeate was milk ultrafiltration in a mineral membrane system followed by permeate vacuum concentration, crystallization, separation and crystal washing with 't\1Iter at 5°e and drying. From mill permeate with 0,027% total nitrogen, 0,49% ash and 4,71% of lactose it was possible to obtain lactose with a purity of 99,3%, 0.660% ash and 0,07% total nitrogen contents
Mestrado
Mestre em Tecnologia de Alimentos
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Boccia, Juliana Nogueira. "Aproveitamento de diferentes tipos de soro de leite na elaboração de bebidas lácteas acidificadas carbonatadas." Universidade Federal de Juiz de Fora (UFJF), 2018. https://repositorio.ufjf.br/jspui/handle/ufjf/6913.
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A proposta deste estudo foi oferecer novas alternativas para o aproveitamento sustentável do soro desproteinado através do desenvolvimento e disponibilização de tecnologias simples de fabricação de bebidas lácteas acidificadas carbonatadas, com vida útil estendida, sem a utilização de tratamentos térmicos extremos. Foram utilizados três diferentes tipos de soros desproteinados (permeado de ultrafiltração, soro de ricota e soro ácido obtido da fabricação de queijos coagulados por acidificação direta), que normalmente são descartados pelas indústrias de laticínios. Para cada tipo de soro foram produzidas bebidas acidificadas carbonatadas em 3 repetições que foram analisadas ao longo do período de 60 dias. Verificou-se diferenças significativas entre as bebidas em relação á acidez, pH e viscosidade. Porém, para cada bebida, não houveram diferenças significativas em relação ao tempo, o que significa que permaneceram estáveis sob esses aspectos durante os 60 dias de armazenamento. Entretanto, pôde - se observar a deposição de proteínas que iniciou entre 20 e 30 dias de estocagem , em razão do pH baixo, e à perda de capacidade do estabilizante de manter essas proteínas dispersas. Os produtos apresentaram estabilidade microbiológica durante todo o tempo de estocagem sob refrigeração, não apresentando contagem de microrganismos patogênicos, confirmando assim a eficácia das barreiras microbiológicas aplicadas (pH, tratamento térmico e dióxido de carbono). As análises sensoriais demonstraram que as bebidas apresentaram boa aceitação. No entanto, a bebida produzida com soro permeado de ultrafiltração obteve maior aceitação e foi preferida em relação às demais. Ao longo do tempo de estocagem as bebidas apresentaram a mesma aceitabilidade sensorial. A bebida láctea desenvolvida pode agregar valor ao soro desproteinado permitindo o seu uso adequado e sustentável por parte das indústrias de laticínios.
The purpose of this study was to offer new alternatives for the sustainable use of unprocessed whey through the development and availability of simple technologies for the production of acidified carbonated dairy drinks with an extended shelf life without the use of extreme heat treatments. Three different types of deproteinated sera (ultrafiltration permeate, ricotta whey and acid whey obtained from the manufacture of cheeses coagulated by direct acidification) were used, which are normally discarded by the dairy industry. For each type of serum, acidified carbonated beverages were produced in 3 replicates that were analyzed over the 60 day period. There were significant differences between the beverages in relation to acidity, pH and viscosity. However, for each beverage, there were no significant differences in time, which means that they remained stable under these aspects during the 60 days of storage. However, protein deposition occurred between 20 and 30 days of storage due to the low pH and the loss of capacity of the stabilizer to keep these proteins in solution. The products presented microbiological stability during the whole storage time under refrigeration, not counting pathogenic microorganisms, thus confirming the effectiveness of the applied microbiological barriers (pH, heat treatment and carbon dioxide). Sensory analysis showed that the drinks were well accepted. However, the beverage produced with permeated ultrafiltration serum obtained greater acceptance and was preferred over the others. Throughout the time of storage the drinks presented the same sensorial acceptability. The developed dairy beverage can add value to the unprotected whey allowing its proper and sustainable use by the dairy industries.
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Duy, Daniela. "PIC1, eine Eisen-Permease in der inneren Hüllmembran von Chloroplasten." Diss., lmu, 2009. http://nbn-resolving.de/urn:nbn:de:bvb:19-105669.
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Lin, Yibin. "Structural and Functional Studies of Melibiose permease of escherichia coli." Doctoral thesis, Universitat Autònoma de Barcelona, 2012. http://hdl.handle.net/10803/107893.
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Els transportadors de membrana tenen un paper molt important en el manteniment de la fisiologia normal de l'organisme, així com en l'eficàcia i la seguretat dels fàrmacs. Per tant, és molt important obtenir noves dades de l'estructura i la funció d'aquest tipus de proteïnes de membrana. La melibiosa permeasa (MelB), un transportador de membrana, és de gran interès, ja que pot utilitzar diferents sucres (ja sigui α- o β-galactòsids) i cations (Na+, Li+ i H +), mentre que altres simportadors com la lactosa permeasa, un membre de la important superfamília de facilitadors, utilitza només H+. Això implica que la MelB ha de presentar algunes característiques úniques en quant al reconeixement i el transport dels substrats. L'estudi en profunditat de l'estructura i funció de la MelB ens pot proporcionar millores clau en la comprensió del mecanisme de co-transport dels transportadors de membrana. Les dades actuals d’índole bioquímica, biofísica o estructural de la MelB no ens proporcionen una escena clara del mecanisme de reconeixement de substrats, i tampoc expliquen la reorganització estructural que es produeix i que en última instància, genera els canvis conformacionals necessaris per al transport a través de la membrana.
En aquesta tesi, he utilitzat tècniques espectroscòpiques, així com mètodes de cristal·lografia de macromolècules per explorar l'estructura i funció de la MelB. En primer lloc, m'he centrat en l’estudi del mutant R149C, el qual no pot unir el sucre i no pot transportar. En segon lloc, he estudiat el paper de l'hèlix V a partir de la substitució individual dels aminoàcids per cisteïna, per mutagènesi dirigida. Finalment, hem cristal·litzat el transportador MelB i hem aplicat difracció de raigs X per intentar obtenir la seva estructura 3D.
Els resultats mostren que la mutació R149C fixa la MelB en una conformació oberta cap al citoplasma. Per tant, l’Arg149, situada probablement al final del cantó citoplasmàtic de l'hèlix V, és una cadena lateral crucial per al mecanisme de reorientació de la MelB. Un altra resultat important és que l’Ala155, situat probablement cap el punt mig de l’hèlix V, és un residu essencial tan per la unió de Na+ com de melibiosa, ja que el mutant A155C perd absolutament qualsevol capacitat d'unir els substrats. Per altra banda, es proposa que l'hèlix V ha d'estar involucrada en el mecanisme de reorientació de la MelB.
Després de diversos intents de cristal·litzar la proteïna, hem estat capaços d'obtenir cristalls de la MelB silvestre i del mutant R149C, solubilitzats en β-DDM. Després de l'optimització, el millor cristall difracta a uns 8 Å a la font de radiació sincrotró.Membrane transporters play a very important role to maintain the normal physiology of the organism as well as in drug safety and efficacy. Therefore, it is very important to gain new information on the structure and function of this type of membrane proteins. Melibiose permease (MelB), a membrane transporter, is of great interest because it can use different sugars (either α- or β-galactosides) and cations (Na+, Li+, and H+), whereas other symporters like lactose permease, a member of the major facilitator superfamily uses only H+. This implies that MelB should present some unique substrate recognition and transport characteristics. The in-depth study of the structure and function of MelB may provide us with key advancements in the understanding of the cotransport mechanism of membrane transporters. The current biochemical, biophysical, and structural data for MelB fail to give us a clear scene of the substrates recognition mechanism, and to explain the structural reorganization that occurs and that ultimately forces the conformational changes needed for transport through the membrane. In this thesis, I used spectroscopic techniques as well as macromolecular crystallography methods to explore the structure and function of MelB. Firstly, I focused on the R149C mutant, which cannot bind sugar and cannot transport. Then I continued to study the role of helix V by cysteine scanning mutagenesis. Finally, I tried to crystallize the MelB transporter and apply X-ray diffraction to obtain its 3D structure. The results showed that the R149C mutation fixes the MelB in an inward-facing conformation. Therefore, Arg149, located probably in the cytoplasmic half of transmembrane helix V, is a crucial side chain for the reorientation mechanism of MelB. Ala155, located probably in the middle of helix V, is an essential residue for either Na+ or melibiose binding, since the mutant A155C absolutely loses the capability to bind substrates. The helix V should be involved in the reorientation mechanism of MelB from the outward-facing to the inward-facing conformation. After several attempts of crystallizing the protein, we were able to obtain crystals of MelB wt and R149C mutant solubilized in β-DDM. After optimization, the best crystal diffracted to about 8Å at the synchrotron radiation source.
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Gal, Yona. "Microbubble interferences with silt density index measurements of ultrafiltration permeate /." [Sede-Boker] : Ben-Gurion University of the Negev, 2007. http://aranne5.lib.ad.bgu.ac.il/others/GalYona.pdf.
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Walshaw, David L. "The general amino acid permease of Rhizobium leguminosarum biovar viciae." Thesis, University of Reading, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.283765.
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Worthen, Denise Lynne. "Lactose binding to the E. coli symport protein Lac permease." Diss., Pasadena, Calif. : California Institute of Technology, 1989. http://resolver.caltech.edu/CaltechTHESIS:11242009-093118312.
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Maier, Florentine, and Julia Brandl. "They're Natural and Everywhere: How Evaluative Practices Permeate the Organization." SpringerOpen, 2008. http://dx.doi.org/10.1007/BF03342703.
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How do evaluative practices become natural and ubiquitous in an organization? In this paper we integrate findings from previous empirical work on the adoption of evaluative practices in organizations with insights from institutional theory and social psychology research for advancing the understanding of possible states of evaluative practices within organizations and the processes through which organizations become permeated by evaluative practices. Our conceptual model suggests that once evaluative practices have gained a foothold in an organization, they tend to be applied to an increasing number of organiza-tional problems and become taken for granted.
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Hwang, Seokhwan. "Anaerobic Treatment of Whey Permeate Using Upflow Sludge Blanket Bioreactors." DigitalCommons@USU, 1993. https://digitalcommons.usu.edu/etd/5400.
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Whey permeate was anaerobically digested in laboratory scale upflow anaerobic sludge blanket reactors. Nine hydraulic retention times between 5 and 0.2 days were examined with a fixed influent concentration of 10.6 ± 0.2 g COD/L.
Chemical oxygen demand removal efficiency ranged from 99.0 to 18.9% and maximum production rate of methane gas was 2.67 L/L/day at a hydraulic loading rate of 12.97 kg COD/m3/day. About 70% of the chemical oxygen demand removed was converted to methane.
Both the nonlinear least square method with 95% confidence interval and linear regression were used to evaluate kinetic coefficients. The maximum substrate utilization rate, k, and half saturation coefficient, KL, were determined to be 1.269 ± 0.163 Kg COD/kg VSS/day and 1.000 ± 0.179 kg COD/kg VSS/day. The yield coefficient, Y, and biomass decay rate coefficient, Kd, were also determined to be 0.160 ± 0.012 kg VSS/kg COD and 0.027 ± 0.004 day-1, respectively.
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Gupta, Sona. "Rational design and delivery of peptide drugs." Thesis, Bangor University, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.323850.
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Duran, i. Hortalà Màrius. "Permeació transdèrmica d'una sèrie de benzodiazepines." Doctoral thesis, Universitat de Barcelona, 2002. http://hdl.handle.net/10803/1613.
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INTRODUCCIÓ: Les benzodiazepines figuraren entre els grups terapèutics de més consum (en import) del Sistema Nacional de Salud de l'estat Espanyol durant els anys 1999 i 2000 (Ministerio Sanidad y Consumo, 2000; 2001).
L'administració d'aquests fàrmacs a l'organisme es realitza majoritàriament per via oral. Una alternativa a la via oral, per a fàrmacs idònis, és la via transdèrmica. Els avenços en tecnologia farmacèutica han cristal·litzat en l'obtenció, per a determinats fàrmacs, de sistemes d'alliberament transdèrmic (SAT) coneguts amb el nom de pegats transdèrmics.
Les característiques de les benzodiazepines les fan estar dins del grup de fàrmacs candidats a ser potencialment usats per aquesta via.
En aquest treball s'ha realitzat un estudi comparat del comportament transdèrmic d'una sèrie de benzodiazepines (alprazolam, clobazam, clonazepam, lorazepam, midazolam, pinazepam).
OBJECTIUS DEL TREBALL
·Realització d'un estudi comparatiu in vitro del pas de diferents benzodiazepines a través de pell humana.
·Obtenció de correlacions entre paràmetres transdèrmics i físico-químics a fi i efecte de poder predir comportaments d'altres membres de la sèrie no sotmesos a experimentació.
·Estudi preliminar de l'activitat superficial i les cinètiques de penetració de les benzodiazepines seleccionades en monocapes artificials com a metòdica ràpida i senzilla per a l'elecció de penetrants.
PLA DE TREBALL I RESULTATS
1. Posada a punt de les metòdiques analítiques per cromatografia líquida d'alta eficàcia (CLAE) i la seva validació corresponent dins l'àmbit de concentracions de treball.
2. Es van determinar experimentalment paràmetres fisico-químics representatius del pas de fàrmac a través de la pell, com la solubilitat i el logaritme del coeficient de distribució (log D) per a intentar obtenir posteriorment correlacions matemàtiques amb paràmetres transdèrmics.
3. A continuació es va procedir a determinar el perfil de permeació in vitro de totes les benzodiazepines estudiades a través de pell humana, amb ajust matemàtic.
4. Es van fer estimacions dels paràmetres biofarmacèutics que caracteritzen el pas através de la pell (constant de permeabilitat, flux i període de latència) mitjançant l'ajustat de models representatius.
5. A partir dels paràmetres físico-químics i transdèrmics es va intentar de trobar correlacions matemàtiques entre ambdós.
6. Amb els fàrmacs de la sèrie seleccionats es va realitzar un estudi preliminar de l'activitat superficial i les cinètiques de penetració en monocapa artificial.
7. Finalment es va intentar determinar una possible correlació in vitro pell humana / in vitro activitat superficial.
CONCLUSIONS
Del treball realitzat s'indiquen a continuació algunes de les conclusions més significatives :
- En les condicions de treball emprades en els estudis transdèrmics la solubilitat de les benzodiazepines assajades, estan compreses entre 100.5 microgr·ml-1(Lorazepam) i 16 microgr·ml-1(Midazolam).
- No s'ha trobat una relació inversament proporcional entre solubilitat i coeficient de repartiment pel conjunt de benzodiazepines estudiades.
- Els valors de log P trobats experimentalment són majoritàriament del mateix ordre que els estimats a partir de les bases de dades KOWWIN i SciFInder 2001.
- Les diferencies estadístiques trobades entre els paràmetres de permeació transdèrmica corresponents als fàrmacs assajats, no estan esbiaxades pel factor pell.
- La constant de permeabilitat transdèrmica (kp) més elevada la presenta el Midazolam, amb un valor de 13.15·10-3 cm·h-1, i la kp més baixa la presenta l'Alprazolam.
- El flux més elevat el presenta el Diazepam.
- S'han predit les concentracions plasmàtiques en estat d'equilibri estacionari, a partir dels fluxos experimentals, en cap cas els valors estimats s'han situat dins de marge de concentracions terapèutiques.
- S'han realitzat estudis d'activitat superficial amb Alprazolam i Diazepam per avaluar la utilitat de la tècnica com a metòdica predictiva de l'activitat intrínseca de la permeació transdèrmica.
- L'increment de la pressió superficial de l'Alprazolam en presència de d-limonè està d'acord amb l'augment de kp que s'observa, en presència del mateix penetrant, en els estudis de penetració transdèrmica. Els increments de pressió estan directament relacionats amb els augments de la constant de permeabilitat.
- De les correlacions lineals múltiples assajades per a les benzodiazepines entre log kp i paràmetres físico-químics, el log P, pes molecular i punt de fusió, influeixen significativament en la permeació transdèrmica.
- El disseny d'un sistema d'administració transdèrmica d'una benzodiazepina comporta fer un estudi amb l'addició de penetrants a fi d'incrementar el flux transdèrmic d'aquesta sèrie de fàrmacs.
"RELATIONSHIP BETWEEN PREDICTED PERMEATION PARAMETERS BASED ON PHYSICOCHEMICAL PROPERTIES AND EXPERIMENTAL PERMEATION THROUGH HUMAN SKIN FOR A SERIES OF BENZODIAZEPINES. BEHAVIOUR IN PHOSPHOLIPIDS MONOLAYER".
ABSTRACT
Transdermal delivery of drugs is regarded as an alternative route to oral administration for certain drugs. The administration of drugs by this route overcomes the potential disadvantage of oral route, mainly presystemic elimination and side effects like digestive disturbances. Validated mathematical models represent an economically advantageous approach for the assessment of skin permeation, and their use is recommended before full-blown in vitro in vivo experiments are conducted. The transdermal permeation of the most important anxiolytics, namely, the benzodiazepines (alprazolam, clobazam, clonazepam, diazepam, lorazepam, midazolam and pinazepam) was studied in vitro with human skin. Permeation membrane consisted of abdominal human skin obtained from surplus of plastic surgery. The purpose of the study was to evaluate the physico-chemical suitability of these drugs for transdermal formulation, to predict the respectives permeation coefficients based on those values and to compare those results with experimental permeation parameters. Also it was studied benzodiazepines behaviour in phospholipids monolayer as a predictive and quickly method for determining skin permeability coefficients.
Methods. Benzodiazepines were quantified by HPLC-UV. For permeation experiments we used Franz-type vertical diffusion cells from Crown Glass Company, (Sommerville, NY) with an effective permeation area of 2.54 cm2 and a receptor compartment volume
of approximately 13 mL were used.
Among benzodiazepines assayed Midazolam showed the highest permeability coefficient (kp=11640 x 10-6 cm·h-1) while Lorazepam and Alprazolam exhibited the lowest values (kp=730 x 10-6 and 650 x 10-6 cm·h-1).
By a mathematical multilineal method we propose an empirical equation to predict experimental human skin permeability coefficient values of a series of benzodiazepines based on respectives Partition coefficient, Molecular weight, Melting point and Solubility.
The equation obtained to predict the permeability coefficient of benzodiazepines based on physicochemical properties gave a good correlation (R2=0.9851 and F=5.83%). Considering the whole transdermal permeation profile and required therapeutic plasma concentrations, none of the benzodiazepines reached therapeutic values, requiring to be formulated in the presence of suitable enhancers for reveal therapeutical usefulness.
KEYWORDS: Benzodiazepines, Human skin, Transdermal permeation, Permeation parameters, phospholipids monolayers.
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Waldbusser, George Gerard. "Infaunal effects on permeable sediment processes." College Park, Md.: University of Maryland, 2008. http://hdl.handle.net/1903/8099.
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Thesis (Ph. D.) -- University of Maryland, College Park, 2008.Thesis research directed by: Marine, Estuarine, Environmental Sciences Graduate Program. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
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Ore, Andrade Harold Oscar Rosil, and Diaz Miguel Angel Portillo. "Propuesta de diseño de mezcla para un concreto permeable de FC=175kg/cm² en veredas." Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2019. http://hdl.handle.net/10757/635423.
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El Perú presenta diversas eventualidades como las lluvias, que retrasan distintas actividades que promueven el crecimiento económico del país. Las zonas urbanas necesitan una mejora continua del entorno con mejores infraestructuras para promover el crecimiento y reducir los accidentes. En la actualidad, se necesita fomentar por el medio local soluciones innovadoras para la evacuación de altas precipitaciones.
El concreto permeable es un tipo de concreto cuya tecnología permite que el agua discurra a través de su estructura por la alta porosidad que posee a diferencia del concreto tradicional. Es fabricado de agregado grueso y material cementante, con un bajo porcentaje de finos de hasta el 10%.
Esta investigación consiste en proponer un diseño de mezcla de concreto permeable de f’c=175kg/cm² aplicado en veredas que satisfaga distintos requerimientos establecidos por las normas CE010 de Pavimentos Urbanos, ACI 211.3R, ACI 522R-10 y los propios de la zona de aplicación. Para ello se realizó una batería de 12 diseños de mezcla con relaciones a/c 0.30, 0.35 y 0.38; agregados de HUSO 7 y 67; cementos portland tipo 1 Sol y Quisqueya; y aditivo Z fluidizante SR. Se realizaron ensayos en estado fresco: Slump, peso volumétrico y contenido de vacíos; y en estado endurecido: Resistencia a la compresión y flexión, y permeabilidad. Finalmente se realizó un prototipo con el diseño que presentó mejores características con el propósito de validar la investigación y se realizo un comparativo entre las veredas de concreto permeable y tradicional.Peru presents various eventualities such as rainfall, which delay different activities that promote the country's economic growth. Urban areas need continuous improvement of the environment with better infrastructure to promote growth and reduce accidents. At present, innovative solutions for the evacuation of high rainfall need to be promoted through the local environment. Permeable concrete is a type of concrete whose technology allows water to flow through its structure due to the high porosity it possesses, unlike traditional concrete. It is made of coarse aggregate and cementitious material, with a low percentage of fines of up to 10%. This research consists in proposing a permeable concrete mix design of f'c = 175kg / cm² applied in sidewalks that satisfies different requirements established by the CE010 standards of Urban Pavements, ACI 211.3R, ACI 522R-10 and those of the area of application. For this, a battery of 12 mixing designs with a / c ratios of 0.30, 0.35 and 0.38; aggregates of HUSO 7 and 67; portland cements type 1 Sol and Quisqueya; and fluidizing Z additive SR. Fresh tests were performed: Slump, volumetric weight and void content; and in a hardened state: resistance to compression and flexion, and permeability. Finally, a prototype was made with the design that presented better characteristics with the purpose of validating the research and a comparison was made between the permeable and traditional concrete sidewalks.
Tesis
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Sen, Gupta Soma. "Purine and pyrimidine transport in Candida spp." Thesis, University of Cambridge, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.296640.
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Schuster, Cordelia Friederike. "Structural and molecular characterisation of the oligopeptide permease of Escherichia coli." Thesis, Bangor University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.262450.
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Ziegler, Maria Anne. "Mutagenesis studies of the DctA C₄ dicarboxylate permease of Sinorhizobium meliloti." Online access for everyone, 2004. http://www.dissertations.wsu.edu/Thesis/Fall2004/M%5FZiegler%5F090904.pdf.
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Cain, Natalie E. (Natalie Elaine). "Transport activity dependent regulation of the yeast general amino acid permease." Thesis, Massachusetts Institute of Technology, 2011. http://hdl.handle.net/1721.1/62612.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Biology, 2011.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student-submitted PDF version of thesis.
Includes bibliographical references.
The general amino acid permease Gap1p of Saccharomyces cerevisiae scavenges amino acids from the extracellular medium for use as nitrogen sources in starvation conditions. Because unlimited uptake of both naturally occurring amino acids and amino acid analogs is toxic, Gap1p is active at the plasma membrane only when amino acid levels are low. Gap1p is down regulated when amino acids are abundant by two distinct post-translational mechanisms. Gap1p is regulated post-translationally to respond quickly and efficiently to changing amino acid concentration. An increase in amino acids causes accumulation of Gap1p in the vacuole and inactivation of Gap1p located at the plasma membrane. Conversely, a decrease in amino acid levels allows for redistribution of Gap1p from internal membranes to the cell surface. Here I examine the mechanism of amino acid regulation of Gap1p. Previous studies of Gap1p sorting have focused on the trans-acting factors required for the distribution of Gap1p between the plasma membrane and internal compartments. To complement this body of work, these studies focus on the cis-elements required for Gap1p sorting. We find that post-translational regulation of Gap1p requires the catalytic activity of Gap1p, indicating that sorting and activity of Gap1p are controlled in cis. Gap1p therefore can serve as an amino acid sensor to control its activity in response to nutrient levels. This finding suggested that post-translational regulation of Gap1p could apply to other transporter proteins in yeast. I examined the activity and localization of a related transporter protein, the histidine-specific permease Hip1p in response to various amino acids, and found that although Hip1p is down regulated only in response to histidine, this regulation is less tightly controlled than the regulation of Gap1p. This observation supports previous assertions that the function of Gap1p in the cell is distinct among yeast amino acid transporters.
by Natalie E. Cain.
Ph.D.
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Calabria, Jorge Luis. "Wastewater Nutrient Recovery Using Anaerobic Membrane Bioreactor Permeate for Hydroponic Fertigation." Scholar Commons, 2014. https://scholarcommons.usf.edu/etd/5348.
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The imbalance between global population growth and resource consumption is indicative of unsustainable practices and foreshadows a grim future of continued resource depletion, food and water scarcity, social inequality, and deteriorating public and environmental health. Meanwhile, the urban centers of the world continue to experience exponential growth resulting in overwhelmed food, water, and sanitation infrastructure. Decentralized and satellite wastewater treatment technologies capable of resource recovery, such as anaerobic membrane bioreactors (AnMBR), foster synergistic opportunities to help manage the food, energy, and water sectors of urban environments. Specifically, the nutrient concentration and high effluent quality of permeate produced by AnMBR systems present applicability in controlled environment agriculture (CEA). The efficacy of AnMBR permeate is evaluated in a hydroponics growth study of cucumber (Cucumis sativus) grown in an outdoor greenhouse and tomato (Lycopersicon lycopersicum) grown indoors. Nutrient analysis of permeate generated by a small, pilot scale AnMBR developed for the treatment of domestic wastewater at ambient temperature indicated sufficient concentrations of N and P elements, however high proportion of NH4+ in N species decreased growth performance. Opportunities for optimizing AnMBR permeate for hydroponics applications exist and thus imply synergistic integration of decentralized AnMBR technology with controlled environment agriculture (CEA) such as hydroponics. A model is proposed for the integration of decentralized AnMBR and CEA systems capable of producing usable plant products within the urban environment. The integration of these systems is proposed as a solution to the challenges of with food security, stressed water supplies, and environmental degradation associated with unchecked urban growth in the developing and developed world
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Mariano, Humberto Rodrigues. "Influência do teor de argamassa e da granulometria da brita na permeabilidade e nas resistências à compressão e à abrasão de concretos permeáveis." Universidade Federal de Goiás, 2014. http://repositorio.bc.ufg.br/tede/handle/tede/4071.
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Rapid urbanization in Brazil produces significant impacts on the quality of life. Rains have been one of the main problems faced by managers of the environment due to the sealing of large areas in cities. This work aims to develop of permeable interlocki ng flooring that can be used in many types of flooring, such as in outdoor areas of homes, plazas, parking lots, roads and pedestrian routes traffic light vehicle traffic. The study examined the permeability of concrete made from gneiss rock with grain size rema ins in diameters (4.75, 6.3 and 9.5) mm and (4.75 and 6.3) mm and uniform particle size of 6.3 mm and 9.5 mm mortar with varying content of 30%, 33%, 35%, 40%, 42% a nd 44%. Compressive strength mortar with content of 30%, 33%, 35%, 40%, 42%, 44% and 55% and abrasion resistance with mortar content of 40%, 42%, 44% and 55%. After analyzing the results of the tests, the concrete produced with mortar content of 42% and continuous particle size of (4.75, 6.3 and 9.5) mm which was attended abrasion resistance based on NBR 12041, the compressive strength based on NBR 9781 and permeability according to standard ACI 522 to R 06 interlocked with permeable concrete floor.
A urbanização acelerada no Brasil produz impactos significativos quanto à qualidade de vida. As chuvas têm sido um dos principais problemas enfrentados pelos gestores do meio ambiente devido à impermeabilização de grandes áreas nas cidades. Este trabalho tem como finalidade o desenvolvimento de um piso intertravado permeável que possa ser utilizado em diversos tipos de pavimentações, tais como em áreas externas de residências, praças, estacionamentos, vias de tráfego de pedestres e vias de tráfego de veículos leves. O estudo analisou a permeabilidade em concretos produzidos com rocha gnaisse com granulometria continua nos diâmetros de (4,75; 6,3 e 9,5) mm e (4,75 e 6,3) mm e com granulometria uniforme de 6,3 mm e 9,5 mm com teor de argamassa variando em 30%, 33%, 35%, 40%, 42% e 44%. Resistência à compressão com teor de argamassa de 30%, 33%, 35%, 40%, 42%, 44% e 55% e resistência à abrasão com teor de argamassa de 40%, 42%, 44% e 55%. Após análise dos resultados dos ensaios, o concreto produzido com teor de argamassa de 42% e granulometria contínua de (4,75; 6,3 e 9,5) mm foi o que atendeu à resistência à abrasão baseado na norma NBR 12041, à resistência à compressão baseada na norma NBR 9781 e a permeabilidade de acordo com a norma ACI 522 R- 06 para piso intertravado com concreto permeável.
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Webb, Peter James. "Melt extraction from a permeable compacting mantle." Thesis, University of Leeds, 2012. http://etheses.whiterose.ac.uk/4682/.
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In this thesis, I present one- and three-dimensional numerical solutions to a two-phase fluid flow problem. The context of these investigations is the evolution of a viscous permeable matrix with a small fraction of melt that is representative of partial melt in the Earth's mantle. The matrix compacts under gravity as melt moves upward. In addition to the simple compaction solution, a range of solutions representing stably propagating waves are possible. I first present a coherent mathematical development of the governing equations for the three-dimensional problem. I then describe a one-dimensional numerical algorithm (1D2PF) that solves the second-order inhomogeneous P.D.E. for the velocity of the viscous matrix, V, for arbitrary melt fraction distribution, φ (the volume fraction occupied by melt). Combined with a time-stepping algorithm which advances the melt fraction in time, fully time-dependent 1D solutions are obtained. With an initial constant base melt fraction φ0 with a superposed localised concentration of melt, I explore the evolution and formation of solitary compaction waves. Using (1D2PF) I investigate the width, amplitude and phase velocity of stable solitary waves, and examine how these parameters depend on the initial conditions, permeability coefficient (k0) and melt and matrix viscosities (ηf and ηm). I demonstrate the existence of a threshold initial width above which secondary solitary waves form, with larger widths producing longer wave trains and smaller widths producing a small-amplitude oscillatory disturbance to the background melt fraction. Experiments with k0, ηf and ηm reveal that the width of the stable solitary wave is simply proportional to the compaction length parameter δ=√k0ηm/ ηf and its velocity varies as δ16/ 9/ηm . I also show that the width of the solitary waves varies as λS=4.6δ and the amplitude follows the relation AS≃89/δ . For initial melt fractions whose distribution is wider than the threshold width, secondary waves are produced with progressively smaller amplitude, and hence slower propagation velocity. I demonstrate that smaller values of δ result in the same volume of melt being partitioned over increasing numbers of relatively thinner solitary waves. The amplitude of the initial perturbation to the background melt fraction however is shown to have no effect on the number of solitary waves produced. A train of such waves arriving at the surface could provide an explanation of intermittentvolcanic activity above a region of partial melt. In a preliminary study of two-phase flow in three-dimensions I have also made significant progress toward the development of a three-dimensional two-phase flow simulation program. To do so, I have adapted the three-dimensional viscous fluid convection program (TDCON) by Houseman (1990). The new program TD2PF depends on a potential-function formulation similar to that of Spiegelman (1993a), in which the divergence of the matrix velocity field, D=∇·V, and the vector potential, A, are the primary variables. I have introduced new functionality to a significantly expanded threedimensional Poisson solver (program TDPOTS) but lack of time prevented a successful conclusion to the development of a general 3D solver for the divergence field D.
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Horsburgh, M. "Bubble propagation in flexible and permeable channels." Thesis, University of Cambridge, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.604240.
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The opening of lung airways from a collapsed, flooded state is an important process in many medical conditions including asthma, cystic fibrosis, emphysema and respiratory distress syndrome. Airway opening also plays a pivotal role in one of the most critical respiratory events in life - the first breath. As a simple physical model of the opening process, one may consider a bubble that propagates down a two-dimensional, flexible-walled channel. Previous workers have investigated the behaviour of this system when the channel walls are impermeable and the bubble advances with constant speed, U. They demonstrated the existence of two steady solution branches: one at low U for which the bubble pressure, pb, decreases with increasing U, contrary to experimental observations; and one at larger U for which pb increases with U. Two potentially important extensions of this model are investigated in this dissertation. First, the walls of lung airways are known to be permeable to small molecules such as water, so the model is extended to include the effects of weak wall permeability. This problem is solved asymptotically by dividing the solution domain into a number of different regions. These include a long region (described by lubrication theory) which extends far ahead of the bubble tip, a Landau-Levich region where the fluid pressure readjusts to allow for the pressure drop across the advancing meniscus, and another long region where the fluid behind the bubble tip slowly drains through the permeable wall. Unlike the impermeable-wall case, it is shown that at low U, pb generally increases with increasing U. The solution also exhibits a receding contract line for which wall permeability eliminates the usual stress singularity.
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McLean, Niall D. "Water wave diffraction by segmented permeable breakwaters." Thesis, Loughborough University, 1999. https://dspace.lboro.ac.uk/2134/7256.
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This thesis presents an original theoretical investigation, based on diffraction theory (extended for permeable structures by Sollitt & Cross [56]), of the performance of segmented rubble mound breakwaters. The amount of protection offered by such a breakwater is a function of the rubble construction (characterized by porosity and permeability), geometry and spacing of segments as well as depending on the the characteristics of the incident wave field. To explore the influence of these factors on the performance of these breakwaters, the diffraction by three related structures have been considered :a periodic array of impermeable blocks, a single continuous rectangular section permeable structure and a periodic array of permeable blocks in shallow water.
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Ying, Wang Li. "Study of the transport mechanism of the melibiose permease from Escherichia coli." Doctoral thesis, Universitat Autònoma de Barcelona, 2015. http://hdl.handle.net/10803/377470.
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El transportador de melibiosa d'Escherichia coli (MelB) pot utilitzar l'energia electroquímica tant de H+, Na+ o Li+ per transportar la melibiosa a l'interior de les cèl·lules en contra del seu gradient de concentració. La MelB és una proteïna de 473 aminoàcids disposats en 12 hèlices transmembrana, amb els extrems N- i C-terminal situats al costat citoplàsmic. Mitjançant l'ús de mètodes espectroscòpics i bioquímics, hem analitzat el paper d'alguns aminoàcids en el bucle 7-8/final d'hèlix VII, que conté diversos aminoàcids aromàtics altament conservats, així com dos residus carregats negativament. Aplicant tècniques de mutagènesi, es van obtenir mutants individuals en què cada aminoàcid s'ha canviat a cisteïna excepte Ser-259, que també es va canviar a alanina. L'espectroscòpia de fluorescència va mostrar que els mutants dels aminoàcids conservats Tyr-256, Tyr-257, Phe-258 i Tyr-260 no uneixen substrats, i els espectres de diferència d'infrarojos de Y256C i Y260C van confirmar l’absència d’unió al substrat. Simulacions de dinàmica molecular van mostrar que aquests residus aromàtics formen part d'un bloc d’interaccions hidrofòbiques que jugaria un paper destacat en el mecanisme de transport. D'altra banda, els espectres de fluorescència i de diferència d’infraroig van demostrar que el mutant Cys del residu Asp-266 i del restant aminoàcid aromàtic del bucle 7-8 Phe-268 són capaços d'unir sodi i melibiosa en una forma semblant a la MelB nativa (Cless). Altres mutants de cisteïna (S259C, S259A, V261C, G263C, D264C, A265C i L267C) del bucle 7-8/final d'hèlix VII mostren una capacitat d'unió similar a Cless. Aquests resultats suggereixen que els aminoàcids conservats Tyr-256, Tyr-257, Phe-Tyr-258 i 260 tenen un paper estructural important en el mecanisme de transport de la MelB.The melibiose transporter from Escherichia coli (MelB) can use the electrochemical energy of either H+, Na+ or Li+ to transport the melibiose to the cell interior against its concentration gradient. MelB is a protein of 473 amino acids arranged in 12 transmembrane helices, with the N- and C-terminus located in the cytoplasmic side. By using spectroscopic and biochemical methods, we have analyzed the role of some amino acids in the loop 7-8/end of helix VII, which contains several highly conserved aromatic amino acids as well as two negatively charged residues. Applying mutagenesis techniques, we obtained single mutants in which each amino acid has been changed to cysteine except Ser-259 also changed to alanine. Fluorescence spectroscopy showed that mutants of the conserved amino acids Tyr-256, Tyr-257, Phe-258 and Tyr-260 did not exhibit substrate binding, and the infrared difference spectra of Y256C and Y260C also showed no substrate binding. Molecular dynamics simulation experiments pointed out that these aromatic residues make part of a hydrophobic lock that would play a significant role in the transport mechanism. On the other hand, infrared difference and fluorescence spectra demonstrated that the Cys mutant of Asp-266 and the remaining aromatic amino acid of loop 7-8 Phe-268 are able to bind sodium and melibiose in a similar way as the wild type MelB (Cless). Other cysteine mutants (S259C, S259A, V261C, G263C, D264C, A265C and L267C) of the loop 7-8/end of helix VII show similar binding capacity as Cless. These results suggest that the conserved amino acids Tyr-256, Tyr-257, Phe-258 and Tyr-260 have an important structural role in the MelB transport mechanism.
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Suárez, Germà Carme. "Investigation of the phospholipid peripheral region of lactose permease in model membranes." Doctoral thesis, Universitat de Barcelona, 2013. http://hdl.handle.net/10803/125470.
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The interaction between a membrane protein and its surrounding phospholipids is thought to be crucial for the correct folding and function of the protein. This thesis is focused on the investigation of the interplay between Lactose permease (LacY), a paradigm for secondary transporters present in the inner membrane of Escherichia coli and model systems mimicking its natural lipid environment. Since the role of phospholipids in LacY’s activity is currently being refined, this work represents a contribution to the field by studying the interaction at two different levels: (i) the LacY interplay with the phospholipids present at the annular region in the vicinity of the protein was studied through FRET measurements between a single-tryptophan LacY mutant and diverse pyrene-marked phospholipids, and (ii) the LacY interaction with the more distanced bulk phospholipids was studied through supported proteo-lipid sheets that were analysed using topography, force-spectroscopy and force-volume Atomic Force Microscopy modes. First, after validating LacY preference for phospholipid fluid (Lα) phases in the studied two-component model systems, a different composition between bulk and annular regions was confirmed. Hence, bulk lipids, which were assimilated to the phospholipids in Lα phase, were mainly formed by PG, while PE was the main component of the annular region. This points to a direct annular phospholipid-LacY selectivity because it discards a random phospholipid distribution near the protein. Second, the LacY selectivity for precise phospholipid species at the annular region was found to be related to: (i) a neutral charged phosholipid (PE or PC, with preference for the former), and (ii) phospholipids with large negative spontaneous curvature (C0) (DOPE > POPE). In addition, D68 was revealed as an important amino acid for the protein annular lipid selectivity. Third, the interaction between LacY and the bulk lipids was described as reciprocal. Accordingly, the presence of the protein largely modified the topography and the nanomechanics of the lipid system, especially for the Lα phase, whilst the nanomechanics of LacY itself were different depending on the surrounding lipid matrix: more force was needed to pull LacY form the DPPE:POPG (3:1, mol/mol) system than from the POPE:POPG (3:1, mol/mol) one. Therefore, the bilayer lipid composition seems to determine the forces governing the LacY tight interaction with the membrane and can be thus decisive for the protein correct insertion and activity.La interacció entre una proteïna de membrana i els fosfolípids que l’envolten és crucial pel bon plegament i la correcta funció de la proteïna. Aquesta tesi està centrada en la investigació de la interacció entre la Lactosa permeasa (LacY), un paradigma dels transportadors secundaris situat a la membrana interna d’Escherichia coli, i sistemes models que mimetitzen el seu entorn lipídic. Aquest treball representa una contribució al camp a través de l’estudi de la interacció a dos nivells: (i) la interacció entre LacY i els fosfolípids presents a la regió anular propera a la proteïna ha estat estudiada a través de mesures de FRET entre un mutant de LacY amb un únic triptòfan i diversos fosfolípids marcats i (ii) la interacció entre LacY amb els fosfolípids més llunyans o bulk s’ha investigat a través de làmines de lípid i proteïna sobre un suport, les quals s’han analitzat a partir de diversos modes de microscòpia de força atòmica (topografia, espectroscòpia de força i force-volume). En primer lloc, s’ha validat la preferència de LacY pels fosfolípids en fases fluïdes (Lα). A més, s’ha confirmat una composició lipídica entre la regió anulars i el bulk. Així, els fosfolípids bulk, considerats com a fosfolípids en fase Lα, tenen PG com a principal component, mentre que PE és el major component de la regió anular. Això sembla indicar una selectivitat entre LacY i els fosfolípids anulars. En segon lloc, s’ha descrit que la selectivitat de LacY per fosfolípid determinat a la regió anular està relacionada amb (i) càrrega neutra i (ii) curvatura espontània (C0) negativa. A més, D68 s’ha assenyalat com un aminoàcid important per la selectivitat de la proteïna envers els lípids anulars. Finalment, s’ha descrit una interacció recíproca entre LacY i els lípids bulk. Així, la presencia de la proteïna modifica la topografia i la nanomecànica del sistema lipídic, especialment de la fase Lα, i, alhora, la nanomecànica de la pròpia LacY varia segons la matriu lipídica que l’envolta. En conseqüència, la composició lipídica de la bicapa sembla determinar les forces que governen l’estreta interacció de LacY amb la membrana i, per tant, aquesta composició és decisiva per la correcta inserció i activitat de la proteïna.
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El-Shamy, Awad. "Effect of permeate suction on the performance of spiral wound nanofiltration module." [Tampa, Fla.] : University of South Florida, 2009. http://digital.lib.usf.edu/?e14.2868.
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