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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
211

Biomassa inicial do híbrido Eucalyptus urophylla vs. Eucalyptus grandis em diferentes espaçamentos /

Sereghetti, Guilherme Corrêa, 1987- January 2012 (has links)
Orientador: Kléber Pereira Lanças / Banca:Marcos Antonio de Rezende / Banca: José Mauro Santana da Silva / Resumo: A utilização da biomassa como insumo energético é uma tendência mundial. No Brasil, dentre as espécies florestais utilizadas, o eucalipto pode ser considerado a mais promissora em decorrência de uma silvicultura avançada e eficiente. O presente trabalho objetivou avaliar o desenvolvimento inicial em diferentes espaçamentos de plantio de um clone de eucalipto. O experimento foi conduzido no município de Sarapuí, estado de São Paulo, utilizando o delineamento experimental em blocos casualizados, contendo três blocos, com nove tratamentos quanto ao espaçamento de plantio, variando a área útil de cada planta entre 2,0 e 8,0 m². A área das parcelas era de 72 m², determinando a quantia de 9 a 36 plantas por parcela, além de uma bordadura dupla. Aos doze meses foram realizadas medições do diâmetro de colo e altura total de todas as plantas de cada parcela para determinação do volume, e foram derrubadas 1 árvore por parcela para cubagem rigorosa e coleta dos discos de madeiras à 0%, 12,5%, 37,5% e 62,5%, a fim de se determinar a densidade básica e porcentagem de casca. Aplicando-se ANOVA para as variáveis volume, densidade básica da madeira, densidade básica da casca e porcentagem de casca, obteve-se diferença significativa ao nível de 5% de significância apenas para as variáveis volume e porcentagem de casca. Com relação ao volume, os menores espaçamentos apresentaram maiores volumes por hectare. Para a variável porcentagem de casca houve certa correlação com a densidade básica da madeira. O tratamento 2x1 apresentou o maior volume por ha / Abstract: The use of biomass as energy input is a worldwide trend. In Brazil, among the forest species, eucalyptus can be considered the most promising due to an advanced and efficient forestry. This study aimed to evaluate the initial development in different planting spacings of a Eucalyptus clone. The experiment was conducted in the city of Sarapuí in São Paulo state, using a randomized complete block design containing three blocks with nine treatments for planting space, varying the floor area of each plant between 2.0 and 8.0 m². The area of plots was 72 m², determining the amount of 9-36 plants per plot, plus a double border. At twelve months have been carried out measurements of stem diameter and total height of all plants in each plot to determine the volume, and were cut down one tree per plot for cubing and collection of disks of wood at 0%, 12.5%, 37.5% and 62.5% in order to determine the basic density and percentage of bark. Applying ANOVA for the variables volume, basic wood density, basic density of bark and bark percentage, obtained a significant difference at 5% significance level only for the variables volume and percentage of bark. With respect to volume, the smallest spacings had higher volumes per hectare. For the variable percentage of bark there was some correlation with basic density. Treatment 2x1 showed the largest amount per ha / Mestre
212

Produção e caracterização da protease coagulante obtida por fermentação submersa a partir do fungo termofílico Thermomucor indicae-seudaticae N31 /

Silva, Bruna Lima da. January 2013 (has links)
Orientador: Roberto da Silva / Banca: Hamilton Cabral / Banca: Gustavo O. Bonilla Rodriguez / Resumo: Proteases constituem uma das mais importantes enzimas industriais e uma de suas principais aplicações é na indústria láctica para produção de queijos. Devido à escassez do coalho tradicional de origem animal, proteases coagulantes microbianas estão sendo pesquisadas como substitutos. O coalho apresenta duas ações hidrolíticas sobre a caseína que caracterizam sua adequação como um bom coagulante, que são a atividade coagulante e a proteolítica. Quanto maior a razão entre coagulante / proteolítica (AC/AP), melhor o coagulante. O presente trabalho objetivou estudar a produção e caracterização da protease coagulante produzida pelo fungo termofilico Thermomucor indicae-seudaticae N31 via fermentação submersa. As condições de produção estudadas foram: natureza e concentração da fonte de carbono e da solução salina, períodos de incubação e velocidade de agitação. Após a produção foi feita a caracterização físico- química que consistiu em determinar as condições de atuações ótimas da enzima. A partir dos resultados, observou-se que a melhor composição no meio fermentativo foi: 4 % de farelo de trigo, 0,3 % de solução salina, 72 horas de incubação a 45 °C e 150 rpm de agitação. Nestas condições os valores da atividade coagulante e da razão AC/AP foram 60,5 U/mL e 510, respectivamente. A enzima coagulante apresentou as características: pH e temperatura ótimos foram 5,5 e 65 °C, respectivamente; pH e temperatura de estabilidade foram 3,5 - 5,0 (retendo cerca de 80 % da atividade depois de 24 horas à temperatura ambiente) e até 60 °C (após uma hora na ausência de substrato). O conjunto dos resultados sugere a conclusão que a protease coagulante é promissora do ponto de vista tecnológico como substituto do coalho animal, principalmente, devido à sua alta especificidade representada pelo elevado valor da razão / Abstract: Proteases are one of the most important industrial enzymes and one of its main applications is in the dairy industry for the production of cheese. Due to the scarcity of renin bovine, microbial coagulants proteases are being researched as a substitute. The rennet has two hydrolytic action on casein featuring its suitability as a good coagulant, which are the milk-clotting and proteolytic activity. The higher the ratio milk-clotting / proteolytic (MCA/PA), the better the coagulant. The present study investigated the production and characterization of coagulant protease produced by thermophilic fungus Thermomucor indicae-seudaticae N31 on submerged fermentation. The production conditions were: nature and concentration of the carbon source and saline, incubation and agitation speed. After production was performed physicochemical characterization that determined the conditions optimal of the enzyme. From the results, it was observed that the best composition of the fermentative medium was: 4 % wheat bran, 0,3 % saline, 72 hours of incubation at 45 °C and 150 rpm agitation. In these conditions the values of milk-clotting activity and the ratio MCA/PA were 60,5 U/mL and 510, respectively. The clotting enzyme had the characteristics: optimum of pH and temperature were 5,5 and 65 °C, respectively, pH and temperature of stability were 3,5 - 5,0 (retaining approximately 80 % of activity 24 hours at temperature environment) and even 60 °C (after one hour in the absence of substrate). The group of results showed that coagulant protease is promising technological point of view as a substitute for animal rennet, mainly due to their high specificity shown by the high value of the ratio / Mestre
213

Análise dos compostos flavorizantes da cana-de-açúcar e otimização da aplicação de extratos ricos em β-glicosidases para liberação de aroma na produção de aguardente de cana /

Aquino, Amanda Jordano. January 2013 (has links)
Orientador: Maurício Boscolo / Coorientador: Roberto da Silva / Banca: Vanildo Del Bianchi / Banca: Milla Alves Baffi / Resumo: A aceitação de bebidas destiladas deriva principalmente de pequenas concentrações de numerosos compostos flavorizantes incluindo alcoóis superiores (óleo fúsel), ésteres, aldeídos, acetais, ácidos, cetonas, lactonas, fenóis voláteis, monoterpenos e norisoprenóides. Dentro deste contexto, para a melhora da qualidade da aguardente de cana-de-açúcar faz-se necessário pesquisas em aplicações tecnológicas e biotecnológicas que visem acentuar o sabor e o aroma, além do desenvolvimento de metodologias de analítica. Assim, neste trabalho foi analisado 21 variedades de cana-de-açúcar, sendo que na variedade SP813250 foi encontrado alta concentração do aldeído 2,6-decadienal, composto de aroma desagradável na produção de bebidas destiladas, e as variedades RB855536, RB987935 e RB975952 produziu grande diversidade e quantidade de voláteis favoráveis ao aroma de bebidas alcóolicas o que leva a inferir que estas variedades possam ser melhor indicadas para a produção de aguardente de cana e além disto, foi possível constatar que maior quantidade de voláteis foram obtidos na casca e nos nódulos da planta. Após a etapa de seleção variáveis para catálise enzimática foram indicadas pelo delineamento fatorial fracionado as seguintes condições: (i) o extrato do fungo Thermoascus aurantiacus, (ii) aplicação pós-fermentação alcoólica, (iii) Brix 16°, (iv) agitação de 200 rpm. Para a fase de otimização foram variados a concentração de extrato enzimático e tempo de aplicação assim, verificou-se aumento da concentração de terpenóides e norisoprenóides como limoneno, terpineol, isoeugenol, 4-alildimetoxibenzeno, α-ionona e linalol em função do tempo de hidrólise e da concentração de β-glicosidase. Nerolidol, 2,6,10,10-tetrametil-1-oxa-espiro-(4,5)-dec-6-eno e β-damascenona tiveram aumento... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The acceptance of liquor derives primarily numerous small concentrations of flavor compounds including higher alcohols (fuel oil), esters, aldehydes, acetals, acids, ketones, lactones, phenols volatile monoterpenes and norisoprenóides. Within this context, to improve the quality of sugar cane-sugar is necessary technological research and biotechnological applications aimed accentuate the flavor and aroma, and the development of analytical methodologies. Thus, this study was analyzed 21 varieties of cane sugar, and the variety SP813250 found high concentration of aldehyde 2,6-decadienal, unpleasant aroma compound in the production of distilled spirits, and the varieties RB855536, RB987935 and RB975952 produced great diversity and quantity of volatile friendly aroma of alcohol which leads to the inference that these varieties may be better suited for the production of sugar cane and in addition, it was found that greater amounts of volatiles were obtained from the bark and nodules of the plant. After the selection stage variables for enzymatic catalysis are indicated by fractional factorial design with the following conditions: (i) the extract of the fungus Thermoascus aurantiacus, (ii) applying post-alcoholic fermentation, (iii) 16° Brix, (iv) stirring 200 rpm. For the optimization phase were varied concentration of enzyme extract and application time thus found to increase the concentration of norisoprenóides as limonene and terpenoid, terpineol, isoeugenol, 4-alildimetoxibenzeno, α-ionone and linalool as a function of hydrolysis time and the concentration of β-glucosidase. Nerolidol, 2,6,10,10-tetramethyl-1-oxa-spiro-(4,5)-dec-6-ene and β-damascenone concentration had increased proportionately enzymatic activity leading... (Complete abstract click electronic access below) / Mestre
214

Extração de invertase solúvel a partir de levedura de panificação (Saccharomyces cerevisiae) / Extraction of soluble invertase from Bakers yeast (Saccharomyces cerevisiae)

Michele Vitolo 28 June 1979 (has links)
Não consta resumo na publicação. / Abstract not available.
215

Performance of zeolite ZSM-5 synthesised from South African fly ash in the conversion of methanol to hydrocarbons

Folifac, Leo January 2018 (has links)
Thesis (Master of Engineering in Chemical Engineering)--Cape Peninsula University of Technology, 2018. / Zeolites have found applications as heterogeneous or solid catalyst in the petrochemical and refining industries. Zeolite ZSM-5 in particular is a highly siliceous solid catalyst with a porous network that consists of medium pore structure (pore openings 5-5.5 A). The solid catalyst (ZSM-5) is well known for its high temperature stability and strong acidity, which makes it an established catalyst used for different petrochemical processes such as Methanol-To-Gasoline (MTG), isomerisation, disproportionation, and cracking. Unlike in the past, the synthesis of zeolite ZSM-5 from other sources that contains silica (Si) and alumina (Al) with the addition of a template (TPBr) as a structure-directing agent is eminent. Its synthesis can be achievable from coal fly ash that is a waste material and a cheap source of Si and Al. Coal fly ash is a waste material that is produced during the combustion of coal to generate electricity. The elemental composition of coal fly ash consists of mostly SiO2 and Al2O3 together with other significant and trace elements. Zeolite ZSM-5 catalyst synthesised from coal fly ash by previous authors required an excessive amount of additional source of silica even though the XRD spectra still show the presence of quartz and mullite phase in the final products. These phases prevented the use of fly ash (solid) as a precursor to synthesise zeolite ZSM-5 products. However, the synthesis of high purity zeolite ZSM-5 products by extracting silica and alumina from South African fly ash and then using it with small amounts of fumed silica was investigated This aim was achieved by fusing fly ash (FA) with sodium hydroxide (NaOH) under hydrothermal condition set at 550 oC for 1 hour 30 minutes. The quartz and mullite phase observed by previous authors was digested by the fusion process. Thereafter, the treatment of fused fly ash filtrate (FFAF) with concentrated H2SO4 (98-99%), precipitated silica and removed Al that therefore increased the Si/Al ratio from 1.97 in fly ash (FA) to 9.5 in the silica extract (named fused fly ash extract). This route was designed to improve the quality of the final products and reduced the amount of fumed silica added to the synthesis mixture prior to hydrothermal synthesis. In this line of investigation, the process of adding fumed silica to the hydrothermal gel was optimised. H-FF1 with a Si/Al ratio of 9.5 was synthesised using the silica extract without the addition of fumed silica. Its XRD, SEM and relative crystallinity results proved that H-FF1 was inactive and hence was not further characterised and utilised in the conversion of methanol to hydrocarbons (MTH). Purer phase zeolite ZSM-5 products (H-FF2 and H-FF3) that were synthesised from silica extract with the addition of small amounts of fumed silica were characterised and successfully used in the methanol to hydrocarbons (MTH) reaction. The synthesised ZSM-5 products had different Si/Al ratio, different morphology, crystal size, BET surface area, and relative crystallinity as well as different trends in the MTH reaction. It was also observed that H-FF2 and H-FF3 (pure phase) solid catalyst deactivated faster than the commercial H-ZSM-5 in the MTH reaction. However, the MTH conversion over H-FF2 competed with that of the commercial H-ZSM-5 within 3 hours of time on stream (TOS) but later deactivated at a faster rate. This was caused by the large crystal size and reduced BET surface area of H-FF2 when compared to the commercial H-ZSM-5. However, H-FF2 performed better than H-FF3 on stream (MTH reaction) due to its smaller crystal size and higher BET. This study has successfully utilised a route that synthesised high purity zeolite ZSM-5 products from the South African fused fly ash extract (FFAE) with the addition of small amounts of fumed silica. The properties of the synthesised zeolite ZSM-5 products (H-FF2 and H-FF3) were similar to that of the commercial H-ZSM-5 as well as active in the MTH reaction. This promoted the utilisation of a waste material (coal fly ash) to synthesise highly siliceous zeolite ZSM-5 products that avoided the presence of mineral phases from fly ash in the final products.
216

Computer vision based embedded fire detection system. / 基於計算機視覺的嵌入式火災監測系統 / Ji yu ji suan ji shi jue de qian ru shi huo zai jian ce xi tong

January 2011 (has links)
Gong, Yibo. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (p. 99-108). / Abstracts in English and Chinese. / Abstract --- p.ii / Acknowledgement --- p.v / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Motivation and Objective --- p.1 / Chapter 1.2 --- Contributions --- p.4 / Chapter 1.2.1 --- Embedded fire detection platform --- p.4 / Chapter 1.2.2 --- Extended CAMSHIFT object detection frame work --- p.5 / Chapter 1.2.3 --- Cooperative multiple camera module --- p.8 / Chapter 1.2.4 --- Aerial maritime survivor detection system --- p.9 / Chapter 1.3 --- Organization of this thesis --- p.9 / Chapter 2 --- Background Study --- p.11 / Chapter 2.1 --- Embedded computer vision --- p.11 / Chapter 2.2 --- Visual Fire detection --- p.12 / Chapter 2.3 --- Color-based object detection and tracking --- p.15 / Chapter 2.4 --- Multiple-camera system cooperation --- p.16 / Chapter 2.5 --- Multiple-camera system calibration --- p.18 / Chapter 3 --- Overview of the embedded fire detection system --- p.22 / Chapter 3.1 --- Functional modules of the detection unit --- p.25 / Chapter 3.2 --- Dataflow within the detection unit --- p.28 / Chapter 4 --- Simulated annealing based MEAN SHIFT framework --- p.31 / Chapter 4.1 --- Simulated annealing framework --- p.33 / Chapter 4.2 --- Combination of simulated annealing with MEAN SHIFT --- p.37 / Chapter 5 --- Extended CAMSHIFT framework for fire detection --- p.42 / Chapter 5.1 --- Bidirectional color histogram training and backprojection --- p.43 / Chapter 5.2 --- Choice of properly sized fire window --- p.48 / Chapter 5.3 --- Alternative optimization based search window resizing --- p.49 / Chapter 5.4 --- Multiple modal particle filter based window size optimization --- p.53 / Chapter 5.4.1 --- Multiple modal particle filter --- p.53 / Chapter 5.4.2 --- Integration of the MMPF with CAMSHIFT framework --- p.57 / Chapter 5.5 --- fire monitoring --- p.63 / Chapter 6 --- The multiple camera module --- p.65 / Chapter 6.1 --- Calibration of the multi-camera system --- p.66 / Chapter 6.2 --- Region mapping and cooperation among the cameras --- p.69 / Chapter 7 --- Implementation and Experiments --- p.71 / Chapter 7.1 --- Implementation --- p.71 / Chapter 7.2 --- Experiments and performance evaluations --- p.74 / Chapter 7.2.1 --- Bidirectional histogram training and backprojection --- p.76 / Chapter 7.2.2 --- Performance of the hybrid Simulated annealing-Mean shift framework --- p.78 / Chapter 7.2.3 --- Alternative optimization based search window resizing for CAMSHIFT --- p.84 / Chapter 7.2.4 --- Multiple modal particle filter based search window resizing for CAMSHIFT --- p.87 / Chapter 7.2.5 --- Real-scenario test on the arm system --- p.94 / Chapter 7.2.6 --- Comparison of the two search window resizing mechanisms --- p.96 / Chapter 7.2.7 --- Accuracy of the multiple camera calibration method --- p.97 / Chapter 8 --- Extension to aerial maritime survivor search --- p.99 / Chapter 8.1 --- Introduction --- p.99 / Chapter 8.2 --- Implementation and experiment results --- p.102 / Chapter 9 --- Conclusion --- p.105 / Chapter 9.1 --- Contribution and summary of the work --- p.105 / Chapter 9.2 --- Future work --- p.107 / Bibliography --- p.109
217

Evaluation of the radiation detection properties of synthetic diamonds for medical applications

Ade, Nicholas 06 May 2015 (has links)
A thesis submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Doctor of Philosophy. Johannesburg, 2015.
218

APPLICATION OF BLOCKCHAIN NETWORK FOR THE USE OF INFORMATION SHARING

Unknown Date (has links)
The Blockchain concept was originally developed to provide security in the Bitcoin cryptocurrency network, where trust is achieved through the provision of an agreed-upon and immutable record of transactions between parties. The use of a Blockchain as a secure, publicly distributed ledger is applicable to fields beyond finance, and is an emerging area of research across many other fields in the industry. This thesis considers the feasibility of using a Blockchain to facilitate secured information sharing between parties, where a lack of trust and absence of central control are common characteristics. Implementation of a Blockchain Information Sharing system will be designed on an existing Blockchain network with as a communicative party members sharing secured information. The benefits and risks associated with using a public Blockchain for information sharing will also be discussed. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2019. / FAU Electronic Theses and Dissertations Collection
219

Exopolymère de Ramlibacter tataouinensis : optimisation de sa production , caractérisation biochimique et génétique / Exopolymer of Ramlibacter tataouinensis : optimization of its production, biochemical and genetic characterization

Jivkova, Desislava 02 July 2018 (has links)
Les exopolysaccharides (EPS) bactériens peuvent avoir une haute valeur ajoutée comme agents de rétention d’eau en cosmétologie. Cette étude s’est intéressée à l’EPS de Ramlibacter tataouinensis TTB310 (Rta). Cette bactérie, isolée d'un sol semi-aride, possède un cycle cellulaire particulier avec des bâtonnets mobiles sensibles à la dessiccation et des kystes non-mobiles produisant un EPS lui permettant de tolérer la dessiccation prolongée. La production d’EPS et la croissance ont été optimisées par le choix de lactate comme source de C et d'énergie, le maintien du pH pendant la croissance avec de l'acide lactique, l’augmentation des concentrations des autres substrats et l’ajout des micro- et macro éléments. Ainsi des quantités suffisantes d'EPS ont été obtenues. Une extraction de l'EPS fermement attachée à la surface des bactéries en utilisant de l’acide trichloroacétique a été élaborée et optimisée. La caractérisation biochimique de l'EPS a été réalisée en combinant différentes techniques : CPG, FTICR-MS, RMN et FTIR. L'unité répétée de l'EPS de Rta est un décasaccharide constitué de ribose, glucose, galactose, mannose, rhamnose, acide glucuronique, désoxyhexose et avec des substituants tels que acétyle, succinyle et méthyle. Enfin, grâce à la disponibilité du génome entièrement séquencé de Rta, le cluster de gènes impliqué dans la production d'EPS a été identifié à l’aide des approches de biologie moléculaire et d'imagerie. La connaissance de la structure de l'EPS de Rta permettra de mettre au point les modifications physico-chimiques nécessaires à sa solubilisation pour en étudier les propriétés rhéologiques. / Bacterial exopolysaccharides (EPS) can have a high added value when used as water retention agents in cosmetology. This work was focused on the EPS of Ramlibacter tataouinensis TTB310 (Rta). Rta, isolated from a semi-arid soil, has a special cell cycle with mobile rods sensitive to desiccation and non-mobile cysts producing an EPS allowing it to tolerate desiccation. EPS production and bacterial growth were optimized by : choosing lactate as a source of C and energy, maintaining the pH during the growth with lactic acid, increasing the concentrations of the other substrates, and additionning of micro- and macro elements. Thus sufficient amounts of EPS have been obtained. An extraction of EPS firmly attached to the bacteria surface using trichloroacetic acid was developed and optimized. The biochemical characterization of Rta EPS was performed by combining different techniques : CPG, FTICR-MS, RMN and FTIR. The repeated unit of Rta EPS is a decasaccharide consisting of ribose, glucose, galactose, mannose, rhamnose, glucuronic acid, deoxyhexose and with substituents such as acetyl, succinyl and methyl. Finally, thanks to the availability of the fully sequenced Rta genome, the gene cluster involved in the production of EPS has been identified, through molecular biology and imaging approaches. The elucidation of the structure of Rta EPS makes possible the future development of the physico-chemical modifications necessary for its solubilization in order to study its rheological properties.
220

Microwave-assisted extraction and synthesis studies and the scale-up study with the aid of FDTD simulation

Dai, Jianming. January 2006 (has links)
No description available.

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