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Hydrolysis mechanisms for iminosulphonate esters and fluorene estersSaid, M. S. January 1985 (has links)
No description available.
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Separation for regeneration : Chemical recycling of cotton and polyester textilesBjörquist, Stina January 2017 (has links)
In 2015, 96.7 million tonnes of textile fibres were produced world-wide. Our high consumption of textiles leads to an increased amount of textile waste. In Sweden, the majority of used clothing and textiles are incinerated due to the lack of recycling techniques. A large amount of post-consumer textile waste is made from blended materials. One of the most common blends, used in as near as all workwear and service textiles, is cotton/polyester. To enable chemical recycling of such textiles, cotton and polyester must first be separated. The aim of this thesis was to separate the materials by depolymerizing the polyester using alkaline hydrolysis. The focus of the work was on how such a process should be performed without a catalyst, in order to result in both a high yield and a high purity of the cotton residue. In order to recycle the residue as a raw material for manufacturing of man-made cellulosic fibres, the cellulose chains in the cotton must also be maintained as unaffected as possible. The polyester in new sheets was completely depolymerized after 390 min at a temperature of 90ºC using a 10% sodium hydroxide concentration and a 1% material-to-liquor concentration. The separation using these conditions gave high yields (above 96%) of the cotton residue regardless of the material fineness used in the process. Furthermore, the separation performed on old sheets show that a pure cotton residue could be produced using higher material concentrations. It was shown that the cotton residue from old sheets, laundered around 50 times, had an intrinsic viscosity comparable to dissolving pulps used for viscose fibre spinning. This study concludes that alkaline hydrolysis without the use of a catalyst could be used to separate cotton and polyester in blended textiles. Furthermore, the findings show that cotton percentage in old sheets only decreased slightly after 50 launderings. Characterization of the materials using ATR FTIR spectroscopy indicate that an integrated textile recycling of hospital bed sheets could be performed since the sheets only contain cotton and polyester in all parts of the sheets.
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Fluorescência molecular em nanopartículas de sílica marcadas com quercetina e rodamina B / Molecular fluorescence in silica nanoparticles doped with quercetin and rhodamine BFrederice, Rafael 16 April 2009 (has links)
Nanoesferas de sílica contendo fluoróforos encapsulados (o complexo quercetina- Al+3 e o corante rodamina B) foram preparadas com alto controle de tamanho e morfologia, utilizando catálise ácida e básica do tetraetilortossilicato (TEOS). As nanopartículas obtidas apresentaram diâmetro da ordem de 200-300 nm, possuindo maior regularidade quando preparadas em meio alcalino. Nas preparações foram utilizados o método de Stöber e o método caroço-casca. Devido à hidrólise da quercetina em meio básico, as partículas funcionalizadas com o flavonóide ou com o complexo quercetina-Al+3, apresentaram maior intensidade de emissão sob catálise ácida. No caso da catálise básica, as partículas apresentaram emissão significativa quando preparadas utilizando um sol de alumina, porém foram obtidos paralelepípedos nanométricos. Os decaimentos de fluorescência para o sistema quercetina-alumina são biexponenciais, em concordância com os dois complexos quercetina-Al+3 formados no interior da nanopartícula de sílica. No caso da rodamina B, foram realizadas medidas de espectroscopia de correlação de fluorescência, que mostraram uma relação entre relaxação difusional com tamanho e autoagregação das partículas. / Silica nanospheres doped with quercetin-Al+3 and rhodamine B were synthesized with high size control and morphology, using acid and basic catalysis of tetraethylorthosilicate (TEOS). The nanoparticle diameter obtained was about 200- 300 nm, with higher regularity when synthesized in alkaline media. The Stöber\'s and core-shell methods were used as preparation methods. Because the alkaline hydrolysis of quercetin, the flavonoid or the quercetin-Al+3 complex doped nanoparticles showed higher emission intensity when acid catalysis was used. When basic catalysis was performed, the particles prepared with an alumina-sol showed expressive emission intensity, but nanometric parallelepipeds were obtained. The quercetin-alumina fluorescence decays are biexponential, agreeing with the two types of quercetin-Al+3 complexes formed in the nanoparticles domain. In the case of rhodamine B, fluorescence correlation spectroscopy (FCS) measurements were performed, showing a relation between diffusion relaxation with size and aggregation behavior.
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Caracterização e solubilização de lodo anaeróbio provenientes de reatores de baixo tempo de retenção celular / Characterization and solubilization of anaerobic sludge produced on short celular retention time reactorLuna, Ysa Helena Diniz Morais de 11 April 2017 (has links)
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Previous issue date: 2017-04-11 / Conselho Nacional de Desenvolvimento Científico e Tecnológico - CNPq / The biological sludge approprieate treatment must be developed in order to take advantages of the products generated during the process. However, the anaerobic sludge treatment is arduous due to the complexity of the substances present in sludge flakes, granules and biofilms, becoming indispensable a pre-treatment step in order to raise the solubilization of the materials. At this study, anaerobic sludges produced by anaerobic reactos with low cell retention time (CRT) (2, 4, 6, 8, 10 and 20 days) were characterized and the 2 and 8 day sludge were submitted to solubilization from pre- treatment commonly called alkaline hydrolysis, consisting of the use of NaOH to reach pH 12, and subjected to stirring for 48 hours at room temperature. The objective of this study was to characterize the anaerobic sludges and evaluate the increase of organic materials solubilization, and make comparisons. The results of the soluble organic materials at 2 and 8 days, showed an increase in the concentrations of 14 and 28 times COD, 20 and 40 times to DQOS, 21 and 63 times to carbohydrates and 31 to 60 times to proteins respectively The solubilization of the 8-day solubilized sludge showed higher solubilization than the 2-day sludge, showing that the use of anaerobic low-CRT reactor to generate sludge is interesting in order to produce a sludge that releases higher amounts of soluble materials after a hidrolisis process, be rapidly degradeted by the anaerobic digestion. / O tratamento adequado do lodo biológico deve ocorrer visando tirar proveito dos produtos gerados durante o processo. No entanto o tratamento anaeróbio do lodo biológico é dificultado pela complexidade das substâncias formadoras dos flocos, grânulos e biofilmes, fazendo-se indispensável uma etapa de pré-tratamento empregada de modo a elevar a solubilização dos materiais. No presente trabalho foram caracterizados 6 lodos anaeróbios provenientes de reatores com baixo tempo de retenção celular (2, 4, 6, 8, 10 e 20 dias) e destes, os lodos de 2 e 8 dias (fase acidogênica) foram submetidos à solubilização a partir do pré-tratamento químico comumente chamado de hidrólise alcalina, consistindo na utilização de NaOH para alcançar pH 12, sob agitação por 48 horas em 28°C. Objetivou-se caracterizar os lodos anaeróbios de baixo tempo de retenção celular (TRC) e avaliar o aumento da solubilização dos materiais orgânicos nos lodos de 2 e 8 dias. Os resultados dos materiais orgânicos solúveis nos lodos de 2 e 8 dias, apresentaram incremento nas concentrações de 14 e 28 vezes para COD, 20 e 40 vezes para DQOS, 21 e 63 vezes para carboidratos e 31 e 60 vezes para proteínas respectivamente. Evidencia-se em todos os parâmetros analisados uma maior solubilização do lodo solubilizado de 8 dias em relação ao lodo de 2 dias, mostrando assim ser interessante a utilização de reatores anaeróbios de baixo TRC para gerar um lodo que após hidrolisado, se solubilize seus materiais e seja degradado mais rapidamente.
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Efeito do grupo racial e do mÃtodo de metilaÃÃo sobre o perfil de Ãcidos graxos da carne caprina do nordeste brasileiro / Effect of racial group and method methylation on fatty acid profile of meat goats of northeast BrazilAdriany das GraÃas Nascimento Amorim 31 August 2005 (has links)
Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / A pesquisa foi desenvolvida no LaboratÃrio de Carnes do Departamento de Tecnologia de Alimentos e no LaboratÃrio de Cromatografia do Departamento de QuÃmica AnalÃtica e FÃsico-QuÃmica da Universidade Federal do CearÃ. Esse trabalho objetivou comparar a composiÃÃo de Ãcidos graxos da carne caprina proveniente de animais de dois cruzamentos entre os grupos raciais BÃer x SRD e Anglo Nubiana x SRD caracterÃsticos do nordeste brasileiro, utilizando-se a metilaÃÃo por hidrÃlise Ãcida ou alcalina para a preparaÃÃo das amostras. No experimento foram utilizados 4 tratamentos com 4 repetiÃÃes, onde os fatores analisados foram dois cruzamentos (BÃer x SRD e Anglo Nubiana x SRD) e duas metodologias de obtenÃÃo dos Ãsteres metÃlicos dos Ãcidos graxos (hidrÃlise Ãcida e alcalina). A anÃlise estatÃstica dos dados utilizou o procedimento GLM (SAS Institute, 2000) para um modelo fatorial e a diferenÃa entre as mÃdias foi verificada pelo teste t. Os resultados mostraram que hà diferenÃa significativa (P<0,05) entre os cruzamentos raciais na composiÃÃo dos Ãcidos graxos do mÃsculo de animais caprinos; sendo que a principal diferenÃa està na composiÃÃo dos Ãcidos graxos saturados C8:0, C10:0, C12:0 e C14:0 no cruzamento Anglo Nubiana x SRD o qual apresentou um maior percentual dos mesmos. Por outro lado, a anÃlise do efeito da metilaÃÃo por hidrÃlise Ãcida e alcalina nÃo apresentou diferenÃa (P<0,05) significativa entre as mÃdias percentuais para a maioria dos Ãcidos graxos exceto para o Ãcido trans-9-elaÃdico C18:1t9 em que a reduÃÃo do seu percentual foi afetada pela hidrÃlise alcalina. O tipo genÃtico analisado afeta, consideravelmente, a composiÃÃo dos Ãcidos graxos dos animais caprinos estudados, influenciando na qualidade da carne. Dessa forma, o cruzamento Anglo Nubiana x SRD devido aos efeitos negativos que os Ãcidos graxos saturados proporcionam à saÃde humana produz carne de qualidade inferior a do cruzamento BÃer x SRD. O tipo de hidrÃlise usado para metilar os Ãcidos graxos, no entanto, nÃo afetou a composiÃÃo da maioria dos Ãcidos graxos das carnes estudadas, sendo que a hidrÃlise alcalina pode reduzir o percentual dos Ãcidos graxos monoinsaturados da sÃrie C18 de configuraÃÃo trans analisados por cromatografia de gÃs. / This research was conducted at the Meat Laboratory, Department of Food Technology and at the Chromatography Laboratory, Department of Chemistry and Physical Chemistry, Federal University of CearÃ. The objective of the study was to compare the fatty acid composition on meat from two breeds of goats from northeast Brazil (BÃer x SRD and Anglo Nubiana x SRD) analyzed by gas chromatography after two procedures (acid and alkaline hydrolysis) to prepare methyl ester derivatives. The experimental design consisted of 4 treatments including two breeds and two types of hydrolysis. Data were analyzed by the GLM procedure (SAS Institute, 2000) and the means were compared by the t-test. Results showed significant (p<0.05) differences in fatty acid composition between breeds. Main differences were detected for the saturated fatty acids C8:0, C10:0, C12:0 and C13:0 which were higher in the Anglo Nubiana x SRD meat related to the BÃer x SRD meat. Hydrolysis procedure, on the other hand, showed no significant (p<0.05) effect for most of the fatty acids except for C18:1t9 which was lower when the derivatization procedure included alkaline hydrolysis. The breed of the animals, therefore, affects the relative composition of fatty acids of the meat. It can be concluded that Anglo Nubiana x SRD goats from northeast Brazil produce meat of better quality than that from BÃer x SRD goats related to fatty acid composition. Alkaline hydrolysis does not affect the yield of most of the fatty acids but it can reduce the yield of the monounsaturated fatty acids of the trans C18 series when analyzed by gas chromatography.
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Fluorescência molecular em nanopartículas de sílica marcadas com quercetina e rodamina B / Molecular fluorescence in silica nanoparticles doped with quercetin and rhodamine BRafael Frederice 16 April 2009 (has links)
Nanoesferas de sílica contendo fluoróforos encapsulados (o complexo quercetina- Al+3 e o corante rodamina B) foram preparadas com alto controle de tamanho e morfologia, utilizando catálise ácida e básica do tetraetilortossilicato (TEOS). As nanopartículas obtidas apresentaram diâmetro da ordem de 200-300 nm, possuindo maior regularidade quando preparadas em meio alcalino. Nas preparações foram utilizados o método de Stöber e o método caroço-casca. Devido à hidrólise da quercetina em meio básico, as partículas funcionalizadas com o flavonóide ou com o complexo quercetina-Al+3, apresentaram maior intensidade de emissão sob catálise ácida. No caso da catálise básica, as partículas apresentaram emissão significativa quando preparadas utilizando um sol de alumina, porém foram obtidos paralelepípedos nanométricos. Os decaimentos de fluorescência para o sistema quercetina-alumina são biexponenciais, em concordância com os dois complexos quercetina-Al+3 formados no interior da nanopartícula de sílica. No caso da rodamina B, foram realizadas medidas de espectroscopia de correlação de fluorescência, que mostraram uma relação entre relaxação difusional com tamanho e autoagregação das partículas. / Silica nanospheres doped with quercetin-Al+3 and rhodamine B were synthesized with high size control and morphology, using acid and basic catalysis of tetraethylorthosilicate (TEOS). The nanoparticle diameter obtained was about 200- 300 nm, with higher regularity when synthesized in alkaline media. The Stöber\'s and core-shell methods were used as preparation methods. Because the alkaline hydrolysis of quercetin, the flavonoid or the quercetin-Al+3 complex doped nanoparticles showed higher emission intensity when acid catalysis was used. When basic catalysis was performed, the particles prepared with an alumina-sol showed expressive emission intensity, but nanometric parallelepipeds were obtained. The quercetin-alumina fluorescence decays are biexponential, agreeing with the two types of quercetin-Al+3 complexes formed in the nanoparticles domain. In the case of rhodamine B, fluorescence correlation spectroscopy (FCS) measurements were performed, showing a relation between diffusion relaxation with size and aggregation behavior.
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Vliv hydrolýzy na chemické a fyzikální vlastnosti PAN hydrogelů / The effect of hydrolysis on chemical and physical properties of PAN hydrogelsBinar, Radim January 2018 (has links)
Předložená diplomová práce se zabývá přípravou hydrogelů odvozených od polyakrylonitrilu a charakterizací jejich fyzikálních a chemických vlastností. Teoretická část shrnuje základní poznatky z oblasti hydrogelů, a také o polyakrylonitrilu. Dále se zabývá možností zpracování polyakrylonitrilu do reaktivní formy, takzvaného aquagelu a jeho zásadité hydrolýzy za účelem přípravy multi-blokových kopolymerů schopných tvořit 3D síť (gel). Experimentální část prezentuje výsledky charakterizace hydrogelů z polyakrylonitrilu neboli HYPANů, které byly připraveny bazicky katalyzovanou hydrolýzou aquagelu. Aquagel byl připraven rozpuštěním a následnou extruzí polyakrylonitrilu. Vzniklé vlákno bylo zpracováno do formy pelet, které byly dále užity pro zmiňovanou hydrolýzu. Hydrolýza byla prováděna za různých podmínek (teplota, NaOH koncentrace, reakční čas) za účelem přípravy produktů s různým stupněm konverze -CN skupiny. Hydrolýzou vytvořené hydrofóbní a hydrofilní bloky, mohou zformovat 3D síť o různých vlastnostech, závisejících na poměru mezi počtem a délkou bloků. Z hydrolyzátů byly připraveny hydrogely jejichž visko-elastické a optické vlastnosti byly dále charakterizovány. Optimalizací přípravy bylo dozaženo multi-blokového kopolymeru schopného vytvořit gel s vhodnými fyzikálními vlastnostmi. Tento gel může najít uplatnění v medicíně, například jako implantáty v oftamologii.
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Chemical Recycling of Blend and Copolymer of Polyethylene Terephthalate (PET) and Polyethylene 2,5-Furandicarboxylate (PEF) Using Alkaline Hydrolysis and Glycolysis.Alsheekh, Ruqayah 15 June 2023 (has links)
No description available.
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The Effect of Biobased Comonomers (Isosorbide and 2,5-furan dicarboxylic acid) on Alkaline Hydrolysis of Co-polyesters, PEIxT and PETFyDas, Ananya January 2021 (has links)
No description available.
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Delningsmetodens inverkan på mikrofiberduk / The splitting method's effect on microfiber clothNORDSTRÖM, LEA, BRUCE, ANNA January 2010 (has links)
I arbetet för Vikan AB var uppgiften att undersöka två olika delningsmetoder för mikrofibrer. Vikan AB är ett företag som utvecklar och framställer textila rengöringsredskap i mikrofibrer och tror sig ha kommit på en ny delningsmetod som förhoppningsvis ger en rad fördelar mot den nuvarande metoden. Den nya framställningsmetoden går under arbetsnamnet Easy Split och har ännu inte introducerats på marknaden.Studien har gått ut på att i fyra olika avseenden utvärdera de olika metodernas för- och nackdelar. De olika aspekterna har således varit processgång, utseende, hållbarhet och funktion. Utvärderingen utfördes med hjälp av en rad undersökningar där bland annat tester i absorption, kvadratmetervikt och fläckreduktion ingick.Många av egenskaperna undersöktes med hjälp av befintliga standarder medan undersökningen av fläckreduktionen skedde med en egenutvecklad testmetod. Till denna metod användes en Martindale vars rörelsemönster och tryck är valdes utifrån att göra testmetoden så verklighetstrogen som möjligt. Resultaten visar att det finns en skillnad på de olika metoderna och att de önskvärda egenskaperna finns starkast representerade hos den Easy split- baserade mikrofiberdelningen. De besparingar Vikan kan göra i och med att byta delningsmetod kan ha inverkan på energi- och vattenförbrukningen vilket resulterar i tidsbesparingar och minskade kostnader. / <p>In collaboration with Vikan AB the task has been to examine the different splitting types for microfibers. The company Vikan AB develops and produces textile cleaning products in microfibers and they now seem to have come up with a new splitting method that hopefully will give a range of advantages compared to the present method. The new method goes under the name Easy split and has not yet been introduced to the market.The study consisted of an analysis of the pros and cons of the methods in four different aspects. The different points of view were processing, appearance, durability and function. The investigation was made with a variety of tests including absorption, weight per square meter and stain reduction. Many of the properties were examined with help of existing standard tests while the stain reduction was analyzed with a method developed for this specific purpose. To represent the real environment a Martindale was used because of its uniform moving pattern. The conclusion indicates that the new splitting method not only results in advantages in adsorption, weight and stain reduction but also in water and energy consumption as well as time and expenses.</p><p>Program: Textilingenjörsutbildningen</p>
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