Дисертації з теми "Hydrolysis conditions"
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Relvas, Frederico Miguel Horta de Albuquerque Moura. "Kinetic study of biomass hydrolysis under high pressure conditions." Master's thesis, Universidade de Aveiro, 2014. http://hdl.handle.net/10773/13848.
Повний текст джерелаThis study was focused on the kinetics of lignocellulosic biomass pre-treatment, in particular CO2-assisted autohydrolysis. The temperature was fixed at 180 ºC, varying pressure from 0 (CO2-free autohydrolysis), 20, 35 to 50 bar. For every pressure, a set of isothermal reactions was performed for various reaction times from 0 and 45 minutes. The pre-treatment resulted in a liquid, solid and gas phases, which were analyzed by HPLC. The liquid phase is essentially composed by sugars both in oligomer and monomer forms, mainly from xylan, also containing acetic acid and degradation products such as furfural and formic acid. In turn, there was an improvement of lignin and glucan’s fraction in the solid residue, being more pronounced for longer treatments. Regarding gas phase collected during depressurization, no traces of products from biomass hydrolysis were found. Basing on the literature and experimental results, 4 kinetic models were developed to predict the behavior of the biomass hydrolysis. Models for xylan, arabinoxylan, glucan and another for acetyl groups were presented. According to the results, the use of CO2 is beneficial for the selective fractionation of biomass, including hemicellulose and amorphous cellulose fractions. Beside, CO2 favors the production of xylooligosaccharides (XOS) achieving a maximum concentration of 14.76 g·L-1 at 50 bar assay vs 13.62 g·L-1 in case of autohydrolysis. Furthermore the conversion of oligomers to monomers is directly proportional to pressure and is enhanced by CO2 presence. With respect to the developed kinetic models, all showed good correlation with experimental data, with R2 as high as 0.9986. In the worst case, the R2 was 0.7865 what considering the so complex multistep analysis process can be acknowledge as a good result. Despite kinetic constants showed an increase of hydrolysis rate of xylan and arabinan in the presence of CO2, they decreases for higher pressures used. In turn, the model for acetyl groups also shows very consistent results with the lowest R2 of 0.9491. The removal of acetyl groups seems to be impaired by the carbon dioxide presence. With respect to glucan, the obtained data shows that reactions are close to zero order as they are independent on the products’ concentrations.
O presente trabalho focou-se no estudo cinético do pré-tratamento de biomassa lignocelulósica, em particular no processo de autohidrólise assistido com dióxido de carbono. O estudo foi feito fixando a temperatura em 180 ºC, variando a pressão entre 0 (ausência de CO2), 20, 35 e 50 bar. Para todas as gamas de pressão foram feitos ensaios isotérmicos entre 0 e 45 minutos. Os pré-tratamentos resultaram em 3 fases, líquida, sólida e gasosa, que foram analisadas por HPLC. A fase líquida é consituída essencialmente por açúcares (monómeros e oligómeros) provenientes maioritariamente do xilana, encontrando-se também ácido acético e produtos de degradação, tais como furfural e ácido fórmico. Por sua vez, as fracções de lignina e celulose na fase sólida aumentaram, sendo mais evidente para tratamentos mais longos. Em relação à fase gasosa, não foram encontrados quaisquer produtos de hidrólise da biomassa. Com base na literatura e nos resultados experimentais, foram desenvolvidos 4 modelos cinéticos para prever o comportamento da hidrólise da biomassa, correspondentes à fracção de xilana, arabinoxilana, celulose e grupos acetilo. De acordo com os resultados obtidos, concluiu-se que o uso de CO2 é útil para fraccionamento selectivo da biomassa, nomeadamente da fracção de hemicelulose e de celulose amorfa, apresentando também melhores resultados do que a autohidrólise na produção de xilooligossacarídeos (XOS), com um máximo de concentração de 14.76 g·L-1 para 50 bar vs. 13.62 g·L-1 na autohidrólise. Além disso, a conversão de oligomeros em monómeros é proporcional à pressão e favorecida pela presença de CO2. Quanto aos modelos cinéticos apresentam uma boa correlação com os dados experimentais, com um R2 mais alto de 0.9986. No pior caso, o R2 foi de 0.7865 que, tratando-se de uma reacção complexa, pode ser considerado um boa resultado. Apesar das constantes cinéticas mostrarem um aumento da hidrólise de xilana e arabinana na presença de CO2, estas decrescem em pressões mais elevadas. Por sua vez, os grupos acetilo também mostram resultados bastante consistentes, com o R2 mais baixo de 0.9491. A remoção de ácido acético parece ser prejudicada pela presença de CO2, enquanto os resultados da hidrólise de glucano sugerem uma cinética de ordem zero, uma vez que a concentração dos produtos aparenta ser independente da concentração dos diferentes produtos.
Molwantwa, Jennifer Balatedi. "The hydrolysis of primary sewage sludge under biosulphidogenic conditions." Thesis, Rhodes University, 2003. http://hdl.handle.net/10962/d1004020.
Повний текст джерелаAwasume, Ignatius Ekwe, and Abel Prince Jabakumar Sathiyaraj. "Optimization of Pre-hydrolysis Conditions for the Production of Biogas." Thesis, Högskolan i Borås, Institutionen Ingenjörshögskolan, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-16495.
Повний текст джерелаAcknowledgements: The authors are heartily thankful to their supervisor Ilona Sárvári Horváth whose guidance and support from the initial to the final level of this thesis work enabled us to gain a deeper understanding of the project.
We equally extend our sincere gratitude to the following persons who never ceased in helping until this work was complete.
Solmaz Aslanzadeh: For sharing her precious time and positive insight in coping with associated challenges of the project.
Hanson Jonas: Your assistance and patience over our laboratory experiments given the limited resources vis-a-vis students demand is quite reminding and saluted.
The support team at Sobacken Biogas plant: Your concern and timely assistance beginning from the supply of the substrate and the opportunity granted us to use your laboratory station greatly ensured results validation.
Program: MSc in Resource Recovery - Sustainable Engineering
Program: MSc in Resource Recovery - Industrial Biotechnology
Ahuja, Nandita. "Impact of operating conditions on thermal hydrolysis pre-treated digestion return liquor." Thesis, Virginia Tech, 2015. http://hdl.handle.net/10919/56647.
Повний текст джерелаMaster of Science
Mirshokraie, S. Ahmad (Seyed Ahmad). "Reactions of a-substituted non-phenolic lignin model compounds under alkaline hydrolysis conditions." Thesis, McGill University, 1988. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=75783.
Повний текст джерелаA series of compounds of the general structure 1-(3$ sp prime$-4$ sp prime$,dimethoxyphenyl)-1-aryl-2-guaiacyloxyethane, where the 1-aryl group bore a hydroxy substituent, also exhibited alkaline hydrolysis, at 150$ sp circ$C, at the $ beta$-carbon. The extent was greater when the 1-aryl group bore an $o$-OH than when it bore a $p$-OH. Thus, the reaction was assisted by the nucleophilic attack of the $o$-phenoxide anion on the $ beta$-carbon.
A relatively high release of guaiacol occurred on treatment of 1-(3$ sp prime$,4$ sp prime$-dimethoxyphenyl)-1-thio-2-guaiacyloxyethane with 2N NaOH at 150$ sp circ$C, and the yield of guaiacol was increased when the terminal sidechain carbon bore a $-$CH$ sb2$OH group. Analogous $ alpha$-thioaryl and $ alpha$-thioalkyl compounds also exhibited greater ether cleavage than their oxy counterparts. The hydrolysis of the $ beta$-guaiacyl group was also enhanced by the presence of $ alpha$-seleno-containing groups.
Henry, Lucile. "Étude et développement d'un procédé propre et innovant de traitement de la surface de fibres céramiques en conditions hydrothermales." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0328.
Повний текст джерелаThis thesis project was carried out in order to develop a hydrothermal processfor the surface treatment of ceramic fibres which are integrated into the fabrication of ceramicmatrix composites (CMCs). A conventional process was developed by Safran Ceramics tomodify the surface chemistry of the Nicalon fibres following 3 steps. The main step consistsin dissolving the oxidised phases at the fibre surface by the use of strong acids. As aconsequence, the chemical homogeneity of the surface is enhanced and a microporouscarbon film is generated helping its compatibilization with the pyrocarbon interphase that isdeposited in between the fibres and the matrix. It was suggested to substitute thisconventional process by a hydrothermal treatment. Indeed, as water displays tunablephysico-chemical properties regarding the temperature and pressure conditions, it waspossible to recover fibres demonstrating reproducible and similar characteristics. Theefficiency and competitivity of the hydrothermal treatment have been assessed throughoptimised surface properties obtained after one single step. Next, the mechanisminvestigation revealed a selective attack of the Si atoms contained in the fibre via hydrolysisreactions. Then, the thermodynamic study pointed out the fact that the process wasdominated by a kinetic regim. Finally, the mechanical caracterisation of the CMCs made ofhydrothermal treated fibres showed results which met all the requirements. These finalobservations allowed us to complete the qualification of the hydrothermal process to treat thesurface of Nicalon fibres
O'Neil, Joseph M. "Factors contributing to the degradation of poly(p-phenylene benzobisoxazole) (PBO) fibers under elevated temperature and humidity conditions." Thesis, Texas A&M University, 2006. http://hdl.handle.net/1969.1/4439.
Повний текст джерелаDong, Shuping. "Effects of acid hydrolysis conditions on cellulose nanocrystal yield and properties: A response surface methodology study." Thesis, Virginia Tech, 2014. http://hdl.handle.net/10919/78102.
Повний текст джерелаMaster of Science
Oyekola, Oluwaseun Oyekanmi. "The enzymology of sludge solubilisation under biosulphidogenic conditions : isolation, characterisation and partial purification of endoglucanases." Thesis, Rhodes University, 2004. http://hdl.handle.net/10962/d1003980.
Повний текст джерелаChassery, Aurélien. "Étude expérimentale et modélisation phénoménologique de l’hydrolyse de sodium tritié : influence des conditions opératoires sur la distribution du tritium dans les effluents." Phd thesis, Toulouse, INPT, 2014. http://oatao.univ-toulouse.fr/13934/1/chassery.pdf.
Повний текст джерелаSun, Peizhe. "Transformation of veterinary ionophore antibiotics under conditions related to water-soil-litter systems." Diss., Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/51880.
Повний текст джерелаBoutiche, Mohamed. "Stabilité physico-chimique des smectites et de l'illite en présence de solutions chargées en électrolytes : étude expérimentale à 150°C." Vandoeuvre-les-Nancy, INPL, 1995. http://www.theses.fr/1995INPL057N.
Повний текст джерелаOliveux, Géraldine. "Influence des conditions d'hydrolyse sous-critique sur le recyclage des matériaux composites fibres de verre / résine polyester insaturé : influence des conditions et de la structure de la résine sur les cinétiques réactionnelles." Nantes, 2012. http://www.theses.fr/2012NANT2110.
Повний текст джерелаA hydrolysis process in batch conditions is applied to break ester bonds of unsaturated polyester resins, crosslinked with styrene, as matrices of composite materials reinforced with glass fibres. Subcritical two-phase conditions appear adapted in view of the involved chemistry. The hydrolysis reaction follows in fact an Aac2 mechanism and requires then conditions enhancing ionic reactions, that is to say in particular sufficient values of the ionic product and of the relative dielectric constant of water. It allows the recovery of the initial monomers of the resin. But the latter’s are subjected to secondary ionic reactions. This hydrolysis treatment also affects the quality of the recovered glass fibres. They are corroded, loosing thus some of their mechanical properties, and require a washing phase to remove residual organic components. Conditions have however been identified as allowing minimizing the degradation of their mechanical properties. Those conditions also allow a maximum recovery rate of the initial monomers of the resin. Thus in less than an hour, it is possible to break almost all the ester bonds of the resin. A longer treatment time only allows secondary reactions to continue. A semi-continuous process appears to be essential to minimize secondary reactions and avoid the washing post-treatment of the fibres. It can also allow a less important degradation of them
Benyattou, Abdelkader. "Thermohydrolyse de solutions d'aluminium III, conditions d'apparition de phases solides : caractérisations physico-chimiques des précipités." Lyon 1, 1994. http://www.theses.fr/1994LYO10071.
Повний текст джерелаBrandam, Cédric. "Optimisation des conditions opératoires d'un procédé de brassage : étude expérimentale et modélisation." Toulouse, INPT, 2001. http://www.theses.fr/2001INPT036G.
Повний текст джерелаBull, Joseph. "The application of hydrolytic enzymes for biotransformations of natural products in non-aqueous reaction conditions." Thesis, University of Exeter, 2009. http://hdl.handle.net/10036/76873.
Повний текст джерелаTeixeira, Stefanie Helena. "Catalyzed hydrolysis of PLA twines in composting conditions." Master's thesis, 2019. https://hdl.handle.net/10216/119302.
Повний текст джерелаTeixeira, Stefanie Helena. "Catalyzed hydrolysis of PLA twines in composting conditions." Dissertação, 2019. https://hdl.handle.net/10216/119302.
Повний текст джерелаHuang, Chiung-Dai, and 黃瓊代. "Component Analysis and Investigation of Hydrolysis Conditions for Chodatella sp." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/s7a843.
Повний текст джерела大仁科技大學
食品科技研究所
104
Microalgae products have been widely used in food, medicines, biomass energy and environmental purposes. In this study, the nutritional compositions, active ingredients and anti-oxidative abilities of microalgae - Chodatella sp. were analyzed, hydrolysis conditions were investigated. Finally, the chodatella sp. hydrolysate was compared with commercial products, such as chicken or clam extracts. The nutritional composition of chodatella sp. contains high amounts of proteins and total dietary fiber, at 35.26% and 42.77%, respectively. The highest mineral content was magnesium at 1225.7 mg/100g. The contents of branch chain amino acids, leucine, valine and isoleucine, and semi-essential amino acids, arginine, were 1443.6, 784.2, 565.4 and 2526.8mg/100g, respectively. The highest concentration of non-essential amino acids was alanine, at 2394.6 mg/100g. The content of non-protein amino acids, γ-aminobutyric acid, was 598.0 mg/100g, accounting for 3.11% of total hydrolytic amino acids. The highest fatty acid compositions were two essential fatty acids, linoleic and linolenic acids, which accounted for 41.34 and 10.24% of fatty acids, respectively; dietary fiber from chodatella sp. was mostly non-soluble dietary fiber. It showed that chodatella sp. could be a low-calorie, protein-rich and nutrient-rich food source. After treated under high heat and pressure to destroy cell-wall structures, the chodatella sp. solutions (algae-water ratio 1:20) were hydrolyzed for an hour with 5% Cellulase AP3 at 30ºC and pH 4.0, and then hydrolyzed with the 3 enzymes – Alcalase, Neutrase and Protease N “Amano” for 48 hours. Analysis of the chodatella sp. hydrolysates showed that concentrations of chlorella growth factors (CGA), total pholyphenols, soluble proteins and peptides after hydrolysis with 5 or 10% Alcalase for 36-48 hours were higher than those treated with the other two enzymes. Comparing the chodatella sp. hydrolysate of 5% Alcalase for 36 hours with commercial chicken essence, clam extracts, plain chicken essence and vegetarian peptide drinks, the chodatella sp. hydrolysate is the only one containing CGA. Soluble protein content, peptides, polyphenols and scavenging effect on DPPH free radicals of chodatella sp. hydrolysate were all higher than 3 commercial clam extract products. In the future, the concentration of beneficial ingredients in the hydrolysate may be increased by increasing the amount of chodatella sp. used, in order to enhance market competitiveness over products such as chicken essence or vegetarian peptide drinks.
Tsai, Hui-Ru, and 蔡慧如. "Investigation of Hydrolysis Conditions for Purple Flesh Sweet Potato Beverage." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/60120656044304948945.
Повний текст джерела大仁科技大學
食品科技研究所
98
Sweet potato is ranked as the sixth major staple food in the world and characterized by its high nutritional values. Due to its higher vitamin, mineral and protein contents than the common vegetables, sweet potato was the major dietary food source for the poor populace in the food-shortage Japanese Occupation Period and the early years after the end of the World War Two. The overall size of Taiwan’s beverage market is approximately 50 billion New Taiwan dollars a year. Characterized by the unique tastes, diversified selections, and convenience, the beverages have become part of our daily life. The purple flesh sweet potato contains abundant anthocyanins and total polyphenols and exhibits multiple health maintenance functions. Therefore, this study is planning to investigate the hydrolytic conditions of the purple flesh sweet potato (PFSP) and develop it into a functional and health-oriented beverage for increasing the sweet potato’s added values. When the pH of the 2.5% steamed and freeze-dry purple flesh sweet potato (SFPSW) was adjusted by the baking soda or citric acid, the optimal hydrolytic conditions obtained with the Response Surface Methodology (RSM) for the α-amylase were pH 6.3, hydrolytic temperature at 60℃, and 30 minute hydrolytic duration. The hydrolytic ratio could reach 59.31%. However, the optimal hydrolytic conditions for the glucoamylase were pH 5.5, hydrolytic temperature at 50 ℃, and hydrolytic duration for 66.8 minutes. The hydrolytic ratio could reach as high as 93.86 %. When the 2.5% SFPSW underwent hydrolysis by the α-amylase and glucoamylase, the hydrolysis ratio was 93.52 %, which did not differ significantly from the single application of the glucoamylase. The hydrolysis ratio of using the alcalase and neutrase enzymes to hydrolyze the proteins of PFSP was significantly higher than the use of the papain and bromelain. Due to the fact that the hydrolysis conditions for the alcalase were relatively more basic and disadvantageous for the stability of anthocyanins in PFSP, the neutrase was therefore selected as the protein hydrolysis enzyme for the PFSP. The analysis of RSM showed the most optimal hydrolysis conditions for the neutrase were pH 6.0, hydrolytic temperature at 50 ℃, and hydrolytic duration for 70 minutes. The hydrolysis ratio was 59.45%. If simplifying the hydrolysis conditions by changing the hydrolysis pH of neutrase’s to be as the same as that for the glucoamylase (pH 5.5), the hydrolysis ratio could also reach 57.18%. When the SFPSW solution was hydrolyzed in sequence by the glucoamylase and neutrase for 70 minutes under the conditions of pH 5.5 and hydrolytic temperature at 50 ℃, the sugar and protein hydrolysis ratio of 91.38% and 69.53%,respectively. To conclude, the 7.5% SFPSW solution was hydrolyzed in sequence by the glucoamylase and neutrase for 70 minutes at the water temperature below 50 ℃ after modifying the pH value to 5.5. The sweet potato juice, which was acquired after the centrifuge process, was flavored with 20% pineapple juice, 10% sugarcane juice and 0.25% lemon juice, and added with 0.5% Gellan for increasing the stability. Thus the preparation of purple sweet potato beverage was completed.
Wang, Chi Wen, and 王祈文. "The influence of dilute acid pretreatment conditions to enzymatic hydrolysis and structural." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/38981148905462597509.
Повний текст джерела明新科技大學
化學工程研究所
97
Under the double impact of global warming and crude oil shortage, the exploration of clean and sustainable resources has become one of the most important issues in many countries. Biomass is a renewable and sustainable resource that can be produced from agricultural feedstocks. However, some biomasses such as starch and sugar are also an imoportant food sources for mankind and livestocks. Utilization of these biomasses may be detrimental to food supply. Therefore, the use of non-ediable biomasses such as lignocellulosic materials as a liquid fuel source is inevitable. Because the structure of lignocellulose is relatively rigid, pretreatments will be helpful to release more sugar from lignocellulose in the following enzyme hydrolysis stage. In this study, dilute-acid hydrolysis was adopted to pretreat rice straw before it was further hydrolyzed by enzymes. The influences of three parameters, including concentration of sulfuric acid, reaction temperature and reaction time, to the extend of decomposition of rice straw, and composition and structure of rice straw are discussed. It was found that a more severe condition released more xylose in acidic hydrolysis. However, byproducts were produced when the operation condition got too severe. The formation of byproducts not only reduced the sugar released in acidic hydrolysis, but also resulted in the low converiosn in enzymatic hydrolysis. Among the acidic hydrolysis conditions investigated in this research, the preatment of rice straw with 1.8% of sulfuric acid at 180℃ for 20 minutes released the most aboundant sugars in a two stage acidic-enzymatic hydrolysis, with 16.68 g of xylose/100g of dry rice straw released, and 24.18 g of glucose/100g of dry rice straw released in acidic hydrolysis and enzymatic hydrolysis, respectively.
Yeh, Wan-Chi, and 葉宛綺. "The Optimal Hydrolysis Conditions for the Conversion of Waste Biomass to Bioethanol." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/16615147633170321249.
Повний текст джерела弘光科技大學
環境工程研究所
99
With the shortage of traditional fossil fuels and global climate change worsening, the development of sustainable and renewable energy is highly emphasized by the industry, government and academia of many countries. Among the renewable energy, the conversion of lignocellulose into bioethanol is believed to have the most potential. Due to the hydrolysis of lignocellulosic materials into reducing saccharides is the bottleneck of producing bioethanol, it is important to clarify the influences of different operating parameters on the hydrolysis efficiency of lignocellulosic materials. Our laboratory has studied the microwave hydrolysis and fermentation of various lignocellulosic materials. In this study, all of the previous experimental conditions and results (132 data) are evaluated by the Principal Component Analysis (PCA) to find the major influences. Then the orthogonal array of Taguchi method and response surface method are applied to optimize the experimental conditions and parameters for the microwave hydrolysis of lignocellulose. The results of Principal Component Analysis show that there are three major components influence the microwave hydrolysis of waste biomass. The first major component is hydrolysis efficiency and reducing sugar. The second major component is microwave temperature. Different microwave temperatures provide different microwave energy for the destruction of cellulose. The third major component is the type and concentration of acid reagent. Different chemical reagents have different reaction ability and affinity with the celluloses. The results of Taguchi orthogonal array shows that the optimum hydrolysis efficiency and conditions are 106.67%, Goosegrass as substrate, with 5% H2SO4, and microwave 110℃ for 30 min. With the response surface method, the optimal parameters are narrowed down. The optimum hydrolysis conditions are Goosegrass, with 2.77% H2SO4 and microwave 117℃ for 37 min. At such conditions, the hydrolysis efficiency and reducing sugar were 118.25% and 18.62 g/L, respectively. The byproducts of lignocellulose hydrolysis are also analyzed and the concentrations are furfural 0.06 g/L, HMF 0.05 g/L, levulinic acid 2.79 g/L and formic acid 0.09 g/L. The hydrolysate at optimal hydrolysis conditions are further fermented with different yeasts. The fermentation temperature is 30℃ and pH is 5.0. The results show the hexose yeast, Saccharomyces cerevisiae, can produce the maximum ethanol concentration 2114.34 mg/L and ethanol yield 95 mg/g. The fermentation efficiency is 80.22%.
Levitt, David Benjamin 1980. "The optimal use of enhanced oil recovery polymers under hostile conditions." 2009. http://hdl.handle.net/2152/18417.
Повний текст джерелаtext
Pan, Chuan-Yi, and 潘泉亦. "Effects of Co-B catalysts synthesis conditions on sodium borohydride hydrolysis reactors design." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/02431300131127318413.
Повний текст джерела淡江大學
化學工程與材料工程學系博士班
101
The objective of this work is to study the effect of various Co-B catalyst synthesis conditions on the catalyst surface morphology and kinetic parameters. The Co/B catalyst was synthesized on IR-120/TP-207 resin surface by using ion exchange and chemical reduction method using NaBH4 as a reduction agent. The reduction conditions which were investigated here were: reduction temperature, NaBH4 concentration, pH value, NaBH4 adding flow rate and different types of resins. The result shows reduction temperature gives the most dramatic effect on surface morphology which is caused by competing reactions of reduction and hydrolysis. Low reduction temperature resulted in a slower Co/B reduction rate and made the catalyst surface denser with a branched structure. This created more surface area than higher reduction temperatures. Low reduction temperature catalyst had the better performance on NaBH4 hydrolysis reaction for hydrogen generation rate. The optimal reduction temperature of the Co-B/IR-120 is 25 oC. The L-H model was used to regress kinetic parameters from the experiment data. The frequency factor, activation energy and adsorption constant are 1.17x109 mol/g-min, 70.65 kJ/mol, and 6.8 L/mol at 40oC, respectively. Finally, the TP-207 resin was used instead of IR-120. After scanning for all catalyst synthesis conditions, the Co-B/TP-207 had the higher catalyst loading, faster hydrogen generation rate and more durability than Co-B/IR-120. A mathematical model was built to design the NaBH4 hydrolysis reactor for hydrogen generation. The operating variables of the system are: reaction temperature and NaBH4 inlet concentration, inlet flowrate. From sensitivity analysis, the dominant variable of the hydrogen generation system is NaBH4 inlet flowrate. The I-4 catalyst shows the better operability at 80oC than other Co-B/IR-120 catalyst.
Moura, Maria Eduarda Nogueira. "Bioactive potential of Mytilus galloprovincialis hydrolysates: effect of hydrolysis conditions and sample processing." Master's thesis, 2021. http://hdl.handle.net/10773/30856.
Повний текст джерелаEste estágio permitiu a integração no projeto ValorMar, que visa melhorar indústrias de aquacultura e ao mesmo tempo fornecer benefícios de saúde ao homem. A aquacultura gera grandes quantidades de desperdício e subprodutos, o que constitui um problema económico, de saúde e ambiental. Estes subprodutos são conhecidos por possuírem potencial nutritivo e bioativo, merecedores de exploração para o fabrico de novos alimentos funcionais que possam exercer efeitos benéficos específicos na saúde e bem-estar humano. Deste modo, o objetivo do presente trabalho foi explorar o potencial bioativo do mexilhão Mediterrâneo (Mytilus galloprovincialis), um produto comum na aquacultura europeia e que gera altas quantidades de desperdício, através de hidrólise enzimática, para extrair compostos potencialmente bioativos que possam ser posteriormente aplicados na criação de novos alimentos funcionais. Homogeneizados de carne de mexilhão foram hidrolisados com Alcalase® e Protamex®, a um pH 7.5, temperatura de 60 °C, com diferentes concentrações de enzima (0, 1, 2 e 3%), de quantidade de substrato (25 e 50 g) e de duração (1 e 2 h). Os hidrolisados resultantes foram posteriormente processados através de liofilização ou ultrafiltração por Amicon®. Condições de pré-tratamento termal, hidrólise e processamento de hidrolisados foram avaliadas para compreender quais levariam à produção de péptidos bioativos. Os hidrolisados foram testados quanto à sua capacidade antioxidante, através do método de eliminação do radical 2,2-diphenyl-1-picrylhydrazyl (DPPH), atividade antimicrobiana, pelas técnicas de difusão em disco e por poço, e atividade anti-hipertensiva pela sua capacidade em inibir a enzima conversora de angiotensina (iACE). Os hidrolisados produzidos revelaram que hidrólise com múltiplas enzimas produz um maior potencial bioativo. A capacidade de eliminar o radical DPPH aumentou com o substrato e mostrou ser inferior com a fração >3 kDa, ao contrário do potencial iACE, que aumentou com a fração ultrafiltrada. Em geral, hidrolisados de mexilhão fervido mostraram um alto potencial anti-hipertensivo. No entanto, nenhum efeito antimicrobiano foi observado nas amostras obtidas nas condições testadas. Estudos posteriores deverão ser realizados, ampliando condições de hidrólise e purificação e testando variados potenciais bioativos, de modo a reunir mais informação acerca do potencial desta espécie como fonte de compostos bioativos. Mais ensaios são requeridos para avaliar a estabilidade dos hidrolisados na matriz do alimento e durante digestão, e o seu efeito nos locais alvos.
Mestrado em Microbiologia
Yu-chain, Hsu, and 許佑銓. "Effects of Delignification Conditions and Surfactants on The Enzymatic Hydrolysis of Steam-Exploded Napiergrass." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/bgx6qb.
Повний текст джерела國立臺北科技大學
有機高分子研究所
100
Napiergrass (Pennisetum Purpureum) is regarded as apotential energy crop, the napiergrass via enzymatic hydrolysis, follow by fermentation can be converted to platform chemicals, such as ethanol, succinic acid, etc. The residual solids after steam explosion were subjected to alkaline hydrogen peroxide treatment before enzymatic hydrolysis. The effects of alkaline hydrogen peroxide residence time and hydrogen peroxide concentration on lignin removal and enzymatic saccharification was studied. When saccharides recovery are considered, a milder alkaline hydrogen peroxide condition should be used, The results indicate that the highest yield of saccharides was the hydrogen peroxide concentration is 2 %(wt/wt), Solid-liquid ratio is 1:20 and the residence time is 30 minute, the lignin removal and enzymatic saccharification were 71.76 % and 84.98 %. In addition, surfactants could incrase enzyme stability and enhance the yield of cellulose to fermentationable sugars. Therefore, we add different types and different concentration of surfactants in the process of enzymatic hydrolysis to explore the effect of surfactant in the Napiergrass hydrolysis. When the surfactant is Tween 80, and a dose of 4.5 g / L, glucose concentrations can be up to the highest.
Wu, Ya-Jing, and 吳雅靜. "Optimization on the Conditions for the Hydrolysis and Probiotic Fermentation on Waste Coffee Grounds." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/65msbn.
Повний текст джерела國立高雄海洋科技大學
水產食品科學研究所
102
This study evaluated the acid, bile salts tolerances and antioxidant ability to optimize the hydrolysis and fermentation conditions of coffee grounds. The highest reducing sugars (33.14±1.64 mg/mL) calibrated by glucose was obtained after 6 hrs hydrolysis of cellulase (150 U/mL) at 37oC, 120 rpm, which is considered to be the optimal hydrolysis conditions. The carbohydrates were significantly released from coffee grounds after hydrolysis, compared to the non-hydrolyzed and commercial coffee extracts by analyzing with thin layer chromatography (TLC). The LAB counts increased from 5.98 to 8.52 log CFU/mL, while the pHs decreased from 4.63 to 3.77, after 24 hr fermentation by 0.05% Lactobacillus plantarum BCRC 10069 at 37oC. The reducing sugars decreased 19.08, 16.93 and 13.87 mg/mL, calibrated by glucose, mannose and arabinose, respectively. And trolox equivalent antioxidant capacity was 7.75 mM (relatively to trolox as standard), respectively. The pH 3 of acid tolerance for 3 hr, the LAB counts remained to 8.19±0.05 log CFU/mL. And the bile salt tolerance was 99.35%. According to the data obtained, coffee hydrolysates are with high potential in the production of functional prebiotics.
Lin, Shou Pu, and 林守璞. "Tryptic hydrolysis of Ca-caseinate by immobilized bioreactor : optimum operating conditions and bioreactor design." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/30509360517638015245.
Повний текст джерелаOyekola, Oluwaseun Oyekanmi. "The enzymology of sludge solubilisation under biosulphidogenic conditions : isolation, characterisation and partial purification of endoglucanases /." 2003. http://eprints.ru.ac.za/143/.
Повний текст джерелаLee, Kuan-Wei, and 李冠緯. "Effect of Co-B catalysts synthesis conditions on hydrogen generation curves during NaBH4 hydrolysis reaction." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/66243271742117001470.
Повний текст джерела淡江大學
化學工程與材料工程學系碩士班
103
In this work, the ion exchange and chemical reduction method were used to synthesize Co-B catalyst. Catalyst loading, surface structure, surface area, metal composition, and crystal structure of Co-B catalyst were investigated in order to understand the connection between surface morphology/composition and the kinetic parameters of NaBH4 hydrolysis reaction. In the ion exchange step, the maximum Co ion exchange amount over TP-207 resin was operated at the synthesis condition: CoCl2 precursor, 3.93 pH, 25 oC ion exchange temperature. In the reduction step, types and concentrations of reduction agents, the concentration of dispersion agent, the reduction temperatures, and injection rates were investigated. The metal composition, surface area, and crystal structure were adjusted by the synthesis variable. The 40 and 80oC activities of Co-B catalyst were improved by adjusting the ratio of Co and B to 2, increasing surface area, and synthesing the certain Co-B crystal type. The results show that the 40 and 80 oC activity of Co-B catalyst was improved while different crystal structure was formation. The optimal result shows the best Co-B catalyst activity was located on following synthesis condition: 0.5 wt.% KBH4, 10 wt.% Ethylene glycol, 75 oC reduction temperature and 5 ml/min injection rate. After regressing kinetic parameters by using L-H model, the catalyst activity can be improved by decreasing KBH4 concentration, reduction temperature and injection rate; the tail of hydrogen generation curve can be improved by decreasing KBH4 concentration and injection rate.
Peng, Xian-Hui, and 彭顯惠. "Screening of the Cellulase-Producing Bacteria and Optimizing the Conditions for the Hydrolysis of Chlorella by Cellulase." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/31684836201347975954.
Повний текст джерела國立臺灣海洋大學
食品科學系
94
A cellulase-producing bacterium, could form a clear zone on carboxy methyl cellulose (CMC) agar plates and designated as C-6, was isolated from soil and identified to be a Cellulomonas sp.. The optimal conditions for its growth were pH 6.8 in nutrient broth with 1.0 % carboxy methyl cellulose (CMC) at temperature of 30 oC and 150 rpm of shaking speed. The maximal cellulase activity was obtained after 96 hr incubation at 30 oC. In order to hydrolyze the cell wall of Chlorella, 10 % and 20 % extracellular enzyme solution hydrolyzed 10 % and 20 % Chlorella water were tested. Higher chlorophyll and protein contents, and lower residual dry weight were observed after the hydrolysis with 10 % extracellular fluid hydrolyzed 20 % Chlorella water. Although the cellulase activity lost gradually during 2 hr hydrolysis at 50 oC, breaking of Chlorella cell walls and release of chlorophyll were clearly observed after 30 min hydrolysis. According to the microscopic observation and measurement of chlorophyll content, obvious lysis of cell walls was obtained after 60 min hydrolysis. In order to increase Chlorella nutritive value, the extracellular fluid was determined protease activity and this property can hydrolyze protein from breaking of Chlorella. After, the peptide contents raised gradually and the free amino acid contents also raised during 3 hr hydrolysis.
Notturno, Melissa Hagstrom. "Lipase-catalyzed hydrolysis of olive oil an in vitro method that mimics conditions in the human duodenum /." 1994. http://catalog.hathitrust.org/api/volumes/oclc/32841349.html.
Повний текст джерелаTypescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 134-146).
Yu, Hui-Chuan, and 游慧娟. "Investigation of different enzymes, ultrasonic treatments, and hydrolysis conditions on the antioxidant properties of porcine liver protein hydrolysates." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/69602188411705469717.
Повний текст джерела國立中興大學
動物科學系所
105
Porcine liver, a by-product of pig slaughtering, is rich in proteins and various nutrients. However, it is rarely used in Taiwan. Enzymatic hydrolysis is used to recover and improve the nutritional and functional properties of proteins from fish and animal byproducts to yield functional components. Ultrasonic has been used to improve protein hydrolysis and modify enzyme activities. Therefore, the objective of this study was to evaluate the effects of different enzymes, ultrasonic treatments, and hydrolysis conditions on the enzymatic hydrolysis of porcine liver for the production of hydrolysates and further characterization of their antioxidant activities. In the experiment 1, the antioxidant activity of porcine liver protein hydrolysates (PLPH) prepared by using Alcalase®, papain, pepsin, or Monascus purpureus microbial suspension (APLH, PaPLH, PePLH, and MPLH, respectively) after various hydrolysis time (3, 6, and 12 h) was evaluated. The results exhibited that the highest yield and peptide content were obtained from APLH, whereas the degree of hydrolysis (DH) of PaPLH was higher than the others. MPLH had the highest 2, 2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity and reducing power, whereas APLH and PaPLH had higher ferrous ion-chelating ability than did MPLH. The molecular weights of all the hydrolysates were <10 kDa. The PaPLH exhibited the highest contents of total amino acids and hydrophobic amino acids. Fifteen antioxidant fractions obtained from MPLH contained one or more of the following amino acids in their sequences: Tyr, Trp, Ala, Pro, Met, Lys, Asp, Cys, Val, Leu, and His. Even though the hydrolysate hydrolyzed by Monascus purpureus microbial suspension exhibited the highest DPPH free radical scavenging activity and reducing power, it had the lowest yield and DH. Therefore, Alcalase® which exhibited the highest yield, peptide content and ferrous ion-chelating ability has been selected to hydrolyze porcine liver proteins in the next experiment. In the experiment 2, ultrasonic was applied on the enzymatic hydrolysis in order to improve the antioxidant activity of the porcine liver hydrolysate. The effect of the ultrasonic pretreatment (0, 15, 30, 45, and 60 s) on the antioxidant activity of PLPH employing Alcalase® was evaluated. The results exhibited the DH and peptide contents of the PLPHs increased as the time of ultrasonication increased. The hydrolysate pretreated with ultrasonication for 60 s exhibited the highest DH and peptide contents. The hydrolysate pretreated with ultrasonication for 45 s exhibited the highest ferrous ion chelating ability and reducing power. The hydrolysate pretreated with ultrasonication for 30 s exhibited the highest DPPH radical scavenging activity and the higher inhibitory activity in the linoleic acid autoxidation system. The molecular weight of the peptides in the hydrolysates was less than 6.2 kDa. In the experiment 3, by using response surface methodology (RSM), the effect of various hydrolysis parameters (E/S ratio, pH, and temperature) on the ultrasonic-assisted enzymatic hydrolysis of PLPH was evaluated. The results exhibited that E/S ratio, pH, and temperature significantly affected the antioxidant activity of the hydrolysate (P < 0.01). The optimal conditions for producing PLPH with the highest scavenging activity by using RSM were as follows: E/S ratio, 1.4% (v/w); temperature, 55.5°C; and initial pH, 10.15. Under these conditions, the degree of hydrolysis, DPPH free radical scavenging activity, ferrous ion chelating ability, and reducing power of PLPHs were 24.12%, 79%, 98.18%, and 0.601, respectively. The molecular weight of PLPH produced under these optimal conditions was less than 5,400 Da and contained 45.7% hydrophobic amino acids. In conclusion, favorable antioxidant hydrolysates from porcine liver enzymatic hydrolysis, which have a potential application for retarding lipid oxidation in food products, can be obtained by using Monascus purpureus microbial suspension, applying of ultrasonic treatment as well as selecting of the optimal hydrolysis conditions.
Mei-Hong, Jhuang, and 莊美虹. "Isolation conditions of feruloylated oligosaccharides from rice bran by using hydrochloric acid,phosphoric acid hydrolysis and antioxidant activity." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/43319381578404372444.
Повний текст джерела國立澎湖科技大學
食品科學研究所
102
This study was to investigate the isolation conditions of feruloylated oligosaccharides from rice bran by using hydrochloric acid, phosphoric acid hydrolysis and the antioxidant activity of feruloylated oligosaccharides. First, tested the range of hygrolyzed rice bran and reaction time the following were: Hydrochloric acid (HCl) concentration- 0.05, 0.1, 0.2, 0.3M; reaction time- 30, 60, 90 minute.Phosphoric acid (H3PO4) concentration- 0.25, 0.5, 1M; reaction time- 60, 90, 120 minute. The result of conditions scope were calculated by regression equation, then obtained a defferential analysis of the optimal conditions for acid hydrolysis and validation tests. The result showed that the optimal conditions of hydrolysis rice bran for hydrochloric acid, phosphoric acid were: Hydrochloric acid (HCl) concentration- 0.144M; reaction time- 62 minute. Phosphoric acid (H3PO4) concentration- 0.64M; reaction time- 72 minute. Furthermore, after hydrolysis rice bran by the optimal conditions of hydrochloric acid and phosphoric acid. The feruloylated oligosaccharides of rice bran was separated and purified from the extract. In the activity of Trolox equivalent antioxidant that the sample of feruloylated oligosaccharides from rice bran by using HCl hydrolysis without neutralization. Concentration of the sample were diluted to 100, 200, 300 μg / ml. The result were 7.2, 11.6, 44.5 trolox eq. μg / g. Activity for the sample of feruloylated oligosaccharides from rice bran by using HCl hydrolysis with neutralization were 3.5, 6.9, 22.4 trolox eq. μg / g. Then, activity of Trolox equivalent antioxidant that the sample of feruloylated oligosaccharides from rice bran by using H3PO4 hydrolysis without neutralization. Concentration of the sample were diluted to 100, 200, 300 μg / ml. The result were 6.7, 12.2, 33.7 trolox eq. μg / g. Activity for the sample of feruloylated oligosaccharides from rice bran by using H3PO4 hydrolysis with neutralization were 5.4, 9.6, 23.9 trolox eq. μg / g. Both of the sample by using hydrochloric acid, phosphoric acid hydrolysis that have activity of Trolox equivalent antioxidant, but the sample without neutralization were higher than the sample with neutralization. The situation might due to the sample after neutralization cause by ion of feruloylated oligosaccharides were dissociation, thereby affecting the antioxidant activity. X The result that ferulic acid connected oligosahharides with higher antioxidant activity.
"Ab initio molecular dynamics study of the solvation effect on chlorine hydrolysis and its reverse reaction." 1999. http://library.cuhk.edu.hk/record=b5890057.
Повний текст джерелаThesis (M.Phil.)--Chinese University of Hong Kong, 1999.
Includes bibliographical references (leaves 48-52).
Abstracts in English and Chinese.
TITLE PAGE --- p.i
THESIS COMMITTEE --- p.ii
ABSTRACT (ENGLISH) --- p.iii
(CHINESE) --- p.iv
ACKNOWLEDGEMENTS --- p.v
TABLE OF CONTENTS --- p.vi
LIST OF TABLES --- p.viii
LIST OF FIGURES --- p.ix
Chapter CHAPTER 1 --- Introduction --- p.1
Chapter Section 1.1 --- Introduction --- p.1
Chapter Section 1.2 --- Reaction of Chlorine Hydrolysis and Its Reverse Reaction --- p.2
Chapter 1.2.1 --- Reaction in the Gas Phase --- p.2
Chapter 1.2.2 --- Reaction in Aqueous Solution --- p.4
Chapter 1.2.3 --- Reaction on Ice Surface --- p.5
Chapter Section 1.3 --- Computational Method --- p.6
Chapter Section 1.4 --- Study of Chemical Reaction by Constraint Molecular Dynamics --- p.8
Chapter 1.4.1 --- Constraint Molecular Dynamics --- p.8
Chapter 1.4.2 --- RATTLE Constraint Dynamics --- p.9
Chapter 1.4.3 --- Free Energy of Chemical Reaction --- p.10
Chapter 1.4.4 --- Radial Distribution Function --- p.11
Chapter CHAPTER 2 --- "Ab initio Molecular Dynamics Study of the Reaction Between HC1 and HOC1 in Gas Phase, in Aqueous Solution and on Ice Surface" --- p.12
Chapter Section 2.1 --- Structure of the Isolated Molecules --- p.13
Chapter Section 2.2 --- Chlorine Hydrolysis in Aqueous Solution --- p.17
Chapter 2.2.1 --- Model --- p.17
Chapter 2.2.2 --- Results and Discussion --- p.18
Chapter 2.2.3 --- Conclusion --- p.31
Chapter Section 2.3 --- Heterogeneous Reaction of HC1 and HOC1 on Ice Surface --- p.32
Chapter 2.3.1 --- Model --- p.32
Chapter 2.3.2 --- Results and Discussion --- p.36
Chapter 2.3.3 --- Conclusion --- p.45
Chapter Section 2.4 --- "Comparison of the Reaction between HC1 and HOC1 in Gas Phase, in Aqueous Solution and on Ice Surface" --- p.46
REFERENCES --- p.48
Liu, Shu-Ying, and 劉淑櫻. "Distribution of cyanogens in mei fruit at different growth periods and the hydrolysis of cyanogens under simulated gastraintestinal tract conditions." Thesis, 1990. http://ndltd.ncl.edu.tw/handle/51081019677694573862.
Повний текст джерелаGuo, Ya-Ting, and 郭雅婷. "Optimization on conditions for the hydrolysis of shrimp waste by protease and chitinase from Bacillus subtilis YJ1 and Development of probiotics fermented chitooligosaccharide beverages." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/02917216057794960159.
Повний текст джерела國立高雄海洋科技大學
水產食品科學研究所
97
To produce high protease and chitinase activities, extra addition of chitins and CMC to the medium was conducted on the cultivation of Bacillus subtilis YJ-1. When this strain was incubated in a complex medium containing 0.5% (w/v) commercial chitin at 37oC, 150 rpm for 3 days, the highest neutral (655.2 U/mL•min) and alkaline (638.2 U/mL•min) proteases activities were obtained. The chitinases activities were 438.04 U/mL•min and 4.22 U/mL•min measured by neocuproine and DMBA methods, respectively. The shrimp shell solution was subjected to the hydrolysis by the above crude selective enzymes at 50oC for 3-4 hr, the soluble proteins, peptides, total free amino acid and reducing sugar of shrimp hydrolysates increased significantly (p<0.05), compared with those before hydrolysis. This phenomenon suggested the degradation of proteins contained in shrimp shell solution occurred. This study also investigated the effects of glucose content and pH on the fermerntation by Lactobacillus acidophilus BCRC 17010, Bifidobacterium adolescentis BCRC 14608 or Lactobacillus casei BCRC 12272. It was found that addition of 2% glucose at neutra pH was benefit for the growth of Bifidobacterium adolescentis BCRC 14608 (10.68 log CFU/mL after 36 hr fermentation). This result indicated that the shrimp shell hydrolysates were a good medium for Bifidobacterium adolescentis BCRC 14608. The molecular mass of the degraded products by electrophoresis weas approximately 2.5 kDa and the degraded chitooligosaccharides were pentaacetylchitopentaose and N-acetylchitobiose to pentaacetylchitopentaose measured by TLC and HPLC, respectively. The antioxidation ability including trolox equivalent antioxidant capacity, reducing power and Fe2+ ion chelating ability of the hydrolysate were 4 mM, 1.5 nm and 80.42% respectively. These results suggested that the combination use of selective enzymes produced by B. subtilis YJ1 with B. adolescentis BCRC 14608 fermentation could process the shrimp shell into a fermented functional chitooligosaccharide beverages.
Tao, Yuan Ching, and 袁景道. "The Studies on the Effect of Fermenter Production Conditions on Pseudomonas vesicularis MA103 Agarases and on the Application of algal Polysaccharides and Its Oligosaccharides via Agarases Hydrolysis." Thesis, 2001. http://ndltd.ncl.edu.tw/handle/59625431032593577036.
Повний текст джерела國立海洋大學
食品科學系
89
Pseudomonas vesicularis MA103 is a marine bacterium, which has the ability to degrade agar. As P. vesicularis MA103 was incubated in MM-P broth, containing 0.15% agar, 0.1% yeast extract, 1.0 mM CaCl2, 1% b-glycerophosphate and 0.6% NaCl, at 26oC with shaking speed of 120 rpm, the cultured broth could reach 98.30 unit/mL agarase activity and pH value of 6.21 after 48 hr. P. vesicularis MA103 was cultivated in various incubation conditions as (1) 500 mL MM-P broth in a 1 L fermenter, (2) 3 L MM-P broth in a 5 L fermenter, or (3) 3 L MM-P broth with controlled pH value at 6.20 in a 5 L fermenter. While being cultivated in (1) 500 mL MM-P broth, strain MA103 performed 51.91 unit/mL agarase activity. As incubated in (3) 3 L MM-P broth, strain MA103 achieved a higher agarase activity, 101.20 unit/mL. Total carbohydrate contents of algal polysaccharides that extracts from Gracilaria, Porphyra dentata, and Monostroma nitidium with different methods are ranged from 23.34 to 49.25%. The highest content of sulfate (1.41%) was observed in the polysaccharides extracted from Porphyra dentata as treated with hot water. The highest content of 3, 6-anhydro- galactose (31.26%) was revealed on the polysaccharides extracted from Gracilaria as treated with enzymes or mixture. The highest yield 50.16% of polysaccharide extract was obtained when Porphyra dentata was treated with enzymes or mixture. Total sugar contents of oligosaccharide lysates derived from algal polysaccharides extracts following digested by P. vesicularis MA103 agarases at 26oC for 48 hr are ranged from 5.74 to 31.26%. Molecular weight of the oligosaccharide mixture, derived from eight algal polysaccharides extracts that digested by P. vesicularis MA103 agarases at 26oC for 48 hr, were determined by the gel permeation chromatography (with Sephadex G-10) are in the range of 292.0 - 1689.6 Da. In the experiment of emulsifying properties of algal polysaccharide extracts, as the concentration of algal polysaccharide was increased from 0.0 to 1.0% (w/v), the emulsifying activity of the reacting mixture was also increased. When 1.0% polysaccharide extract, derived from Porphyra dentata with hot water treatment, were added to the emulsifying mixture, the best performance of emulsifying activity and emulsion stability were measured as 100% and 90%, respectively. Porphyra oligosaccharide mixtures, which obtained from the porphyral polysaccharide extract with enzyme or hot water treatment followed by digested by P. vesicularis MA103 agarases, were added (2.0%) individually to the emulsifying reacting solution, and the resulting emulsifying activity was 52.63 and 56.25%, repectively. The emulsifying activity of the rest oligosaccharide mixtures were measured between 45.00 and 46.66%. As to the emulsion stability, various oligosaccharide lysates did not show significant differences, which are among 40.00 and 46.15%. After dehydration under 60oC for 8 hr, eight algal polysaccharides extracts showed the capability of film formation. The higher penetration force (796.96 g) was observed happened on the film made by the polysaccharide extract derived from Gracilaria that treated with enzymes. Among various oligosaccharide hydrolysates, film made by oligosaccharides derived from Gracilaria polysaccharide extract treated with enzyme and then digested by P. vesicularis MA103 agarases, showed a higher penetration force (288.66 g).
(14010168), Mirta Golic. "The preparation of dienes and dienophiles containing nucleic acid bases." Thesis, 1999. https://figshare.com/articles/thesis/The_preparation_of_dienes_and_dienophiles_containing_nucleic_acid_bases/21397758.
Повний текст джерелаThe work presented in this thesis deals initially with the synthesis of rigid polyalicyclic dienes and dienophiles with pyrimidine moieties inbuilt in a rigid fashion (building BLOCKS). This work has allowed the production of a new class of ribbon molecules with precisely defined size, shape and position of the pyrimidine ring. In the second stage of the project, an assessment of their ability to participate in cycloaddition reactions as pyrimidine building BLOCK* components was investigated.
2,4-Dimethoxy-1,3-diazaanthracene (I) has acted as the pyrimidine transfer reagent for preparing building BLOCKs. The Diels-Alder adducts IV and V (Scheme I), prepared by reaction of I with norbomadiene, are new pyrimidine dienophilic BLOCKs. Both I and 2,4-dichloro-1,3-diazaanthracene (II) were active in photochemical [4π+4π] cycloaddition reactions with cyclopentadiene to form a second class of building BLOCKs VII and VIII (Scheme I). In addition, the photodimerisation of I and II was studied and structures IX-XII assigned on the basis of spectral and X-ray method.
The 2,4-dichloro-photoadduct VIII is of particular importance for this work since it is easily hydrolysed (2M NaOH, 60 °C, overnight) to the corresponding uracil XIII In contrast, thermal adducts IV and V were very difficult to hydrolyse (NaOH fusion) to uracils XIV and XV (Figure I).
The availability of pyrimidine BLOCKs which contain a reactive π-bond, e.g. (IV, V, VII and VIII) has enabled us to employ 3,6-di(2'-pyridyl)-s-tetrazine (XVI) and ACE (Alkene plus Cyclobutene Epoxide) coupling methods to obtain precisely functionalised ribbon molecules in a direct, convergent synthetic strategy.
The synthesis of the bis-pyrimidines by coupling norbornene reagents using 3,6-di(2'-pyridyl)-s-tetrazine is illustrated in Scheme II. In the first step, s-tetrazine XVI was reacted with pyrimidine BLOCK V under basic conditions to generate the dihydropyridazine XVII. This diaza-1,3-diene was reacted with a further equivalent of V under high pressure conditions to yield the bis-pyrimidines XVIII and XIX, which were separated by radial chromatography. The same procedure was used to link pyrimiclines to other effectors by using alternative alkenes in the second step.
The ACE coupling protocol is illustrated by the reaction of alkene VIII with the dimethoxynaphthalene-containing epoxide XX (Scheme III). The reaction can be conducted under thermal or photochemical conditions and is considered to proceed via 1,3-dipolar intermediate formed by ring-opening of the epoxide C-C bond of XX (See Chapter 4).
Each class of coupled adduct could be hydrolysed to the corresponding uracil by using either acid (XXII) or base (XXIII) hydrolysis conditions, the choice depending on the structure of the molecule in question and its substituents.
The work presented in this thesis involves a deal of new work and has been instrumental in the development of the Lego®-based BLOCK assembly protocol for ribbon molecules construction.
Tsai, Sheng Fen, and 蔡昇奮. "The study of Hydrolysis Optimal condition of N-2-(vinylbenzylamino)-ethyl-3-aminopropyltrimethoxysilane." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/22625466992855251437.
Повний текст джерела國立中正大學
化學工程研究所
92
The printed circuit board equipped in computers and various type of mechanism is made from single-face or double-face copper clad laminate, which includes the following types: (1) phenolic copper clad laminate made from paper substrate/ phenolic resin; (2) hard copper clad laminate made from glass cloth impregnated with epoxy resin and polyester resin. The glass cloth, which is used in the glass fiber epoxy copper clad laminate, adopts plain weave after being bound into glass yarn, and then use silane coupling agent to conduct surface treatment. The main purpose is to increase adhesion of glass cloth and epoxy interface. The surface of glass cloth impregnated with silane coupling agent will increase not only the interface adhesion with resin, but also the permeability of epoxy resin into glass yarn. In addition, it will increase laminate heat resistance, reduce moisture absorption rate, improve dimensional stability and stabilize the electronic characteristic of glass fiber. It is necessary to hydrolyze alkoxy groups into hydroxide groups before the silane coupling agent is coated on the surface of glass cloth. Then the hydroxide groups will form covalent bonds with the surface’s hydroxide groups. The hydrolysis reaction of silane coupling agent is influenced by the following factors: PH value, acid type, grade of stirring, concentration of silane coupling agent, type of silane coupling agent, aging time and etc. The hydrolysis of Dow Corning’s N-2-(vinylbenzylamino)- ethyl-3-aminopropyltrimethoxysilane(Z-6032) was studied using The Taguchi Method by setting up four factors and three levels. Nucleus magnetism resonance spectroscopic analysis (29Si-NMR-Spectroscopic analysis) was used to measure the relative quantity of D-structure and T-structure in first hydrolysis of Z-6032. After changing various factors and levels, the optimum conditions for the maximum relative quantity of D-structures in the first hydrolysis was figured out. The second hydrolysis solution was then coated on the glass fiber, and the micro-bond pulling out test was conducted to verify the change in bond strength due to the combination with epoxy resin micro drops.
Shih-WeiChang and 張詩偉. "Studies on Effect and Optimizing Condition for Saccharum-Miscanthus Leaves Pretreatment via Acid Hydrolysis." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/46817743500795866829.
Повний текст джерела國立成功大學
化學工程學系
102
The leaves of Saccharum-Miscanthus, which is a hybrid of sugarcane and miscanthus, provide a good biomaterial due to its high holocellulose contain and production. In the present study, dilute acid hydrolysis process is applied to hydrolyze cellulose and hemicellulose to produce reducing sugars such as glucose and xylose. After process optimization, we obtained that under the condition of 30oC, with the leaf size of 3-5mm soaked in 70wt.% H2SO4 solution for 1hr followed by 5wt.% H2SO4 solution hydrolysis under 121oC, 1.2atm for 1hr, the highest total reducing sugar yield was 0.487g reducing sugar/g raw-material-added. To cost down and make it economic viable, we developed a process that using two-stage pretreatment. In the developed process, Saccharum- Miscanthus leaves were first soaked in 30oC, 4wt.%NaOH solution for 6hr, then soaked in 70oC, 20wt.% H2SO4 for 1hr. The two-stage pretreated leaves could give total reducing sugar yield of 0.402g reducing sugar/g raw-material, followed by 5wt.% H2SO4 hydrolysis at 121oC for 1hr.
Huang, Chih-Hao, and 黃致豪. "Sequential Diluted Acid and Enzymatic Hydrolysis of Spent Coffee Ground at High Solids Condition for Bioproductions." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/25619771736019945501.
Повний текст джерела國立雲林科技大學
化學工程與材料工程系
103
Spent coffee ground (SCG) has been indicated as a potential feedstock for bioproductions by many research reports. However, as a kind of lignocellulosic biomass, SCG also requires pretreatment and enzymatic hydrolysis to liberate the fermentable sugars from it. In this study, a bio-refinery concept was applied to fully utilize the SCG. The locally collected SCG was first extracted by hexane to obtain the coffee oil, and then the de-oiled biomass was subjected to dilute acid hydrolysis and enzymatic saccharification to generate fermentable sugars for microbial oil production. In order to have the optimal pretreatment condition, a response surface methodology was applied to investigate the effects of concentration of dilute sulfuric acid (2-6 % w/w) and reaction time (1- 2 hours) on the yield of fermentable sugar from enzymatic saccharification. The result indicated that the reducing sugar yield was around 0.55 g/g biomass at the optimal condition which was corresponding to ~90% conversion rate of biomass carbohydrate.
Wu, Ling-Tsai, and 吳鈴彩. "Establishment of an optimal pasteurization condition of fresh milk by the peptide content from protein hydrolysis in vitro." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/41773484110993331486.
Повний текст джерела東海大學
畜產與生物科技學系
93
Milk is a highly nutritious food, and must be pasteurized to destroy all the pathogenic and microorganisms in order to extend shelf life. However, the different pasteurization conditions could induce physicochemical changes in milk. This study was intended to establish an optimal pasteurization condition of milk using response surface methodology by the peptide content from protein hydrolysis in vitro. The first factor temperature (X1) and the second factor holding time (X2) of response surface were located through preliminary study. Then X1 and X2 were used as the center point of central composite rotatable design in order to establish an optimal pasteurization condition of fresh milk. The physicochemical properties of fresh milk processed from the optimal pasteurization condition were then compared with market milk. Results suggested that temperature (X1) of 81℃ and holding time (X2) of 20 seconds, were used as center point for central composite rotatable design. Fresh milk pasteurized by 81℃ for 20 seconds had the highest peptide content. The alkaline phosphatase and lactoperoxidase activity tests were negative of fresh milk pasteurized by 81℃ for 20 seconds. The L*, b* value and titratable acidity of fresh milk pasteurized by 81℃ for 20 seconds were significantly lower (P<0.05) than market milk. In addition, pH value, available lysine content, undenatured whey protein content and peptide content were significantly (P<0.05) higher than market milk. The electrophoresis showed that fresh milk pasteurized by 81℃ for 20 seconds had more undenatured whey protein than market milk. The overall acceptability of fresh milk pasteurized by 81℃ for 20 seconds in sensory evaluation was among different market milk. Therefore, temperature of 81℃ and holding time of 20 seconds was the optimal pasteurization condition of fresh milk.
Akhurst, P., P. D. Rose, Chris G. Whiteley, and B. I. Pletsheke. "Accelerated sludge solubilisation under sulphate reducing conditions: the effect of hydrolytic enzymes on sludge floc size distribution and EPS composition." 2002. http://hdl.handle.net/10962/d1010430.
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