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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.
91

Crude Glycerin associated with starch or fiber-based energy ingredients at two levels of concentrate for beef cattle /

Lage, Josiane Fonseca. January 2014 (has links)
Orientador: Telma Teresinha Berchielli / Banca: Ricardo Andrade Reis / Banca: Emanuel Almeida de Oliveira / Banca: Mário Luiz Chizzotti / Banca: Marco Antônio Álvares Balsalobre / Resumo: Objetivou-se neste trabalho avaliar os efeitos da alimentação com glicerina bruta (GB; 80% de glicerol) - incluída em 10% da MS da dieta, associada ao milho ou casca de soja (CS) em diferentes teores de concentrado (40 - BC ou 60% - AC) sobre a digestibilidade, fermentação ruminal, desempenho, emissão de metano, características da carcaça e qualidade da carne de bovinos Nelore alimentados em confinamento. Doze novilhos Nelore (401,0 ± 41,5 kg) canulados no rúmen foram usados em um delineamento de quadrado latino truncado replicado, com seis animais em seis tratamentos e quatro períodos para avaliar a fermentação ruminal. Períodos experimentais possuíam 19 dias (14 para adaptação e 5 dias para amostragem). Dietas utilizadas foram: CO - sem GB e milho como ingrediente do concentrado; GBM - inclusão de GB (10% na MS) associada ao milho; GBCS - inclusão de GB (10% na MS) associada á CS. Diferenças em consumo de MS (CMS; P = 0,47), digestibilidade da MS (P = 0,29) e digestibilidade da FDN (P = 0,77) não foram observadas entre dietas. As concentrações de propionato (P < 0,01) e relação acetato:propionato (P < 0,01) foram afetadas pela inclusão de GB nas dietas. As espécies de bactérias e protozoários não foram afetadas pela inclusão de GB nas dietas (P > 0.05). Setenta tourinhos Nelore (373,70 ± 24,70 kg) com 18 meses de idade foram utilizados para avaliar o desempenho e a qualidade da carne. O CMS (P = 0,89) e o GMD (P = 0,98) foram similar entre as dietas. Houve tendência a interação entre teor de concentrado e dietas para emissão de metano (g/kg de MS ingerida; P = 0,07). Animais alimentados com GBM apresentaram melhor eficiência alimentar (g ganho de carcaça (GCr) /kg MS ingerida; P < 0,01). Animais alimentados com GBM ou GBCS apresentaram maior porcentagem de ácidos graxos monoinsaturados (AGM; P < 0,01) e ácido linoléico conjugado (CLA, 18:2 cis-9, trans-11; P < 0,01). GB pode ser utilizada associada ao ... / Abstract: This trial aimed to evaluate the effects of feeding crude glycerin (CG) - 80% glycerol - included on 10% of DM diet, associated with corn or soybean hulls (SH) in different concentrate level (CL; 40 or 60%) on digestibility, ruminal fermentation, performance, methane emission, carcass and meat quality traits of Nellore young bulls fed in feedlot. Twelve ruminally cannulated Nellore steers (401.0 ± 41.5 kg) were used in a replicated truncated Latin Square arrangement of treatments with six animals in six treatments and four periods to evaluate the ruminal fermentation. Experimental periods were 19 d (14 d for adaptation and 5 d to sampling). Diets were: CO - without CG and corn as ingredient of concentrate; CGC - inclusion of CG (10% of DM) associated with corn; and CGSH - inclusion of CG (10% of DM) associated with SH. Differences in DMI (P = 0.47), DM digestibility (P = 0.29) and NDF digestibility (P = 0.77) were not observed among the diets. The propionate concentrations (P < 0.01) and A:P ratio (P < 0.01) were affected by inclusion of CG in diets. The bacteria or protozoa species were not affected by inclusion of CG in the diets (P > 0.05). Seventy Nellore bulls with 18 months of age were used to evaluate the performance and meat quality traits. The DMI (P = 0.89) and ADG (P = 0.98) were similar among the diets. The CL and the diets had a tendency an interaction for methane emissions (g) per kg of DMI (P = 0.07). Animals fed CGC had a greater G:F (g carcass gain/kg DMI; P < 0.01). Animals fed diets with CGC or CGSH showed meat with greater deposition of monounsaturated fatty acids (MUFA; P < 0.01) and CLA (18:2 cis-9, trans-11) contents (P < 0.01). CG can be used to replace corn or SH in 10% of diet DM, without affect the DMI, digestibility and growth of microorganisms in the rumen. The inclusion of CG in diets associated with SH in LC diets tends to decrease the methane emission than animals fed with CGSH in HC diets. When CG is ... / Doutor
92

Effects of Electronic Cigarette Liquid Solvents Propylene Glycol and Vegetable Glycerin on User Nicotine Delivery, Heart Rate, Subjective Effects, and Puff Topography

Spindle, Tory 01 January 2018 (has links)
Electronic cigarettes (ECIGs) are a class of tobacco products that use a heating element to aerosolize a liquid, typically containing nicotine, allowing for user inhalation. Despite their rapid growth in popularity, little is known about ECIGs including how certain device and liquid factors influence nicotine delivery, user physiological and subjective responses, and puffing behavior (puff topography). Limited pre-clinical research has demonstrated that the ratio of two solvents commonly found in ECIG liquids, propylene glycol (PG) and vegetable glycerin (VG), may have an influence on the nicotine content of ECIG aerosols. However, the extent to which PG:VG ratio in ECIG liquids influences acute effects experienced by ECIG users is unknown. The primary purpose of this clinical laboratory study was to examine the influence of PG:VG ratio on plasma nicotine concentration, heart rate (HR), subjective effects, and puff topography in experienced ECIG users. Thirty ECIG-experienced individuals participated in four independent laboratory conditions that differed only by the PG:VG ratio in the ECIG liquid (100:0, 55:45, 20:80, and 2:98). In each condition, participants used a 3.3 volt “eGo” ECIG battery attached to a 1.5 Ohm dual coil “cartomizer” loaded with 1 ml of ECIG liquid (nicotine concentration: 18 mg/ml). Participants completed two ECIG use bouts (10 puffs with 30 sec inter-puff-interval) in each study condition. ECIG PG:VG ratio had a direct influence on nicotine delivery, subjective effects, and puff topography. Nicotine delivery and overall nicotine intake were highest following the use of the liquids containing mostly PG, despite participants taking significantly shorter and smaller puffs in these conditions, suggesting PG may be a more efficient nicotine-delivery vehicle than VG. Abstinence symptoms were suppressed similarly across all PG:VG ratios, and HR also increased in a similar fashion in all conditions following ECIG use. Participants reported significantly lower scores on items assessing sensory ECIG effects following use of the 100PG:0VG liquid, indicating a lower overall satisfaction with this liquid. Further evaluating the influence of PG and VG and other ECIG device and liquid characteristics on ECIG acute effects using clinical laboratory methodologies could inform regulations of these products.
93

Anaerobic Co-digestion of Chicken Processing Wastewater and Crude Glycerol from Biodiesel

Foucault, Lucas Jose 2011 August 1900 (has links)
The main objective of this thesis was to study the anaerobic digestion (AD) of wastewater from a chicken processing facility and of crude glycerol from local biodiesel operations. The AD of these substrates was conducted in bench-scale reactors operated in the batch mode at 35°C. The secondary objective was to evaluate two sources of glycerol as co-substrates for AD to determine if different processing methods for the glycerol had an effect on CH₄ production. The biogas yields were higher for co-digestion than for digestion of wastewater alone, with average yields at 1 atmosphere and 0°C of 0.555 and 0.540 L (g VS added)⁻¹, respectively. Another set of results showed that the glycerol from an on-farm biodiesel operation had a CH₄ yield of 0.702 L (g VS added)⁻¹, and the glycerol from an industrial/commercial biodiesel operation had a CH₄ yield of 0.375 L (g VS added)⁻¹. Therefore, the farm glycerol likely had more carbon content than industrial glycerol. It was believed that the farm glycerol had more impurities, such as free fatty acids, biodiesel and methanol. In conclusion, anaerobic co-digestion of chicken processing wastewater and crude glycerol was successfully applied to produce biogas rich in CH₄.
94

Synthesis, degradation and practical applications of a glycerol/citric acid condensation polymer /

Trenkel-Amoroso, Jan. January 1900 (has links)
Thesis (M.S.)--Oregon State University, 2009. / Printout. Includes bibliographical references (leaves 53-54). Also available on the World Wide Web.
95

Development of a heterogeneously catalyzed chemical process to produce biodiesel

Singh, Alok Kumar, January 2008 (has links)
Thesis (Ph.D.)--Mississippi State University. Department of Agricultural and Biological Engineering. / Title from title screen. Includes bibliographical references.
96

Stoffliche Nutzung von Biomasse mit Hilfe von nah- und überkritischem Wasser homogenkatalysierte Dehydratisierung von Polyolen zu Aldehyden /

Ott, Lothar. Unknown Date (has links)
Techn. Universiẗat, Diss., 2005--Darmstadt.
97

The effects of the secondary carbon source glycerol on the lipid accumulation and fatty acid profile of Rhodotorula glutinis

Easterling, Emily Ruth Echols, January 2007 (has links)
Thesis (M.S.)--Mississippi State University. Department of Biological Sciences. / Title from title screen. Includes bibliographical references.
98

S?ntese e caracteriza??o de novos produtos a partir de glicerina para uso na agricultura

Rocha, Elisiane Dantas 13 May 2016 (has links)
Submitted by Jos? Henrique Henrique (jose.neves@ufvjm.edu.br) on 2017-08-28T19:40:42Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) elisiane_dantas_rocha.pdf: 1578502 bytes, checksum: 6377ba5382224c4f4ab2f117cb851a38 (MD5) / Approved for entry into archive by Rodrigo Martins Cruz (rodrigo.cruz@ufvjm.edu.br) on 2017-08-30T18:46:12Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) elisiane_dantas_rocha.pdf: 1578502 bytes, checksum: 6377ba5382224c4f4ab2f117cb851a38 (MD5) / Made available in DSpace on 2017-08-30T18:46:12Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) elisiane_dantas_rocha.pdf: 1578502 bytes, checksum: 6377ba5382224c4f4ab2f117cb851a38 (MD5) Previous issue date: 2016 / A glicerina bruta, obtida de forma direta no processo de produ??o de biodiesel, ? um insumo abundante e, devido a impurezas, ainda ? pouco atrativa para ser trabalhada como precursor em escala industrial. Apesar da sua aplica??o agr?cola, na fertiliza??o do solo ainda ter recebido pouca aten??o, a glicerina bruta tem potencial de utiliza??o na agricultura, sendo que a associa??o com outros tipos de materiais pode ampliar sua utiliza??o no mercado. O presente trabalho teve como objetivo sintetizar e caracterizar novos produtos a partir de glicerina e ?cido h?mico, para uso na agricultura. Os produtos sintetizados a partir de rea??o de esterifica??o entre glicerina purificada ou bruta, proveniente do processo de produ??o de biodiesel met?lico de ?leo de am?ndoa de maca?ba, utilizando hidr?xido de pot?ssio como catalisador, e ?cido h?mico foram obtidos na forma de p?, de colora??o preta. Os produtos foram caracterizados por espectroscopia no infravermelho com transformada de Fourier (FTIR), an?lise elementar, an?lise de fluoresc?ncia de raios-X, titula??o potenciom?trica e an?lise t?rmica. A modifica??o estrutural do ?cido h?mico por glicerina purificada (AH_GP) e glicerina bruta (AH_GB) originou produtos com caracter?sticas espec?ficas, devido ao tempo de rea??o e os diferentes tipos de glicerina utilizados como mat?ria-prima. Os produtos mostraram modifica??es de grupos carbox?licos em grupos ?ster devido ? s?ntese de esterifica??o, que proporcionou uma forma de modular a quantidade de grupos funcionais presentes na estrutura. A utiliza??o de glicerina bruta no processo promoveu a forma??o de diferentes tipos de ?steres, dependendo do tempo de rea??o. Com um tempo de rea??o curto, ocorreu a forma??o de ?steres de glicerol e ?steres met?licos, devido ? presen?a de metanol residual do processo de produ??o de biodiesel. Quando o tempo de rea??o foi aumentado, os ?steres met?licos foram convertidos em ?steres de glicerol, por transesterifica??o, o que foi confirmado por FTIR e an?lise elementar. Os produtos sintetizados apresentaram ganho de estabilidade t?rmica, o que indicou maior capacidade para reter ?gua comparado ao ?cido h?mico comercial. Dos resultados obtidos pela an?lise de fluoresc?ncia de raios-X, notou-se que os novos produtos cont?m enxofre e pot?ssio. Avaliou-se a capacidade de adsor??o de nitrog?nio amoniacal por amostras dos produtos. Os resultados referentes ? adsor??o de NH4+ foram submetidos ao teste t de Student com n?vel de confian?a de 90%. Os produtos sintetizados t?m capacidade de adsorver nitrog?nio em altas propor??es mesmo com a mudan?a na estrutura qu?mica dos produtos que, ap?s modifica??o tiveram diminui??o na quantidade absoluta de s?tios ativos fortemente ?cidos. / Disserta??o (Mestrado) ? Programa de P?s-gradua??o em Biocombust?veis, Universidade Federal dos Vales do Jequitinhonha e Mucuri, 2016. / The crude glycerin obtained directly in the biodiesel production process, is an abundant raw material, and due to impurities, it is still unattractive to be worked as a precursor on an industrial scale. Despite its agricultural application, soil fertilization still has received little attention, crude glycerin has a potential for use in agriculture and the association with other types of materials can expand its use in the market. This study aimed to synthesize and characterize new products from glycerin and humic acid for use in agriculture. The products synthesized via esterification reaction between purified or crude glycerin, obtained from the production of methyl biodiesel from macauba almond oil, using potassium hydroxide as a catalyst, and humic acid were obtained as a powder of black color. The products were characterized by infrared spectroscopy with Fourier transform (FTIR), elemental analysis, fluorescence X-ray analysis, thermal analysis and potentiometric titration. The structural modification of humic acid by purified glycerin (AH_GP) and crude glycerin (AH_GB) originated products with specific characteristics that varied with the reaction time and the types of glycerin used as a raw material. Transformation carboxylic groups into ester groups was observed, which provided a way to modulate the number of functional groups present in the structure. The use of crude glycerin in the process promoted the formation of different types of esters depending on the reaction time. With a short reaction time, occurred the formation of glycerol esters and methyl esters that resulted from the presence of residual methanol from the biodiesel production process. When the reaction time was increased, the methyl esters were converted to glycerol esters by transesterification, which was confirmed by elemental analysis and FTIR. The products synthesized had greater thermal stability than humic acid, which indicated a higher water-holding capacity than that to commercial humic acid. Results obtained by fluorescence X-ray analysis, it has noticed that the new products contain sulfur and potassium. It was evaluated the ability of ammonium ion by adsorption product samples. The results of the adsorption of NH4+ were submitted to the Student t test with a confidence level of 90. The synthetized products have a capacity adsorb nitrogen at high rates even with the change in their chemical structures that resulted in a reduction in the absolute quantity of strongly acid active sites after modification.
99

Hidrogenólise do glicerol sobre catalisadores de cobre e cromo

Fiuza Junior, Raildo Alves January 2012 (has links)
113 f. / Submitted by Ana Hilda Fonseca (anahilda@ufba.br) on 2013-04-05T17:38:46Z No. of bitstreams: 1 Dissertação_Raildo Alves Fiuza Junior.pdf: 4123130 bytes, checksum: 5d64b18d9c873984e7609ecb4496b552 (MD5) / Approved for entry into archive by Ana Hilda Fonseca(anahilda@ufba.br) on 2013-06-06T15:04:38Z (GMT) No. of bitstreams: 1 Dissertação_Raildo Alves Fiuza Junior.pdf: 4123130 bytes, checksum: 5d64b18d9c873984e7609ecb4496b552 (MD5) / Made available in DSpace on 2013-06-06T15:04:38Z (GMT). No. of bitstreams: 1 Dissertação_Raildo Alves Fiuza Junior.pdf: 4123130 bytes, checksum: 5d64b18d9c873984e7609ecb4496b552 (MD5) Previous issue date: 2012 / CAPES / A conversão catalítica do glicerol em insumos químicos de maior valor agregado é desejável para valorizar a cadeia de produção do biodiesel. O glicerol é obtido principalmente como co-produto do biodiesel, com rendimento de 10% em massa. Uma das vias mais promissoras na valorização do glicerol está na hidrogenólise do glicerol a propilenoglicol (1,2-PD), que é empregado como agente anti-congelante, na produção de polímeros, na indústria de alimentos e cosméticos. Muitos estudos têm relatado a hidrogenólise em fase líquida, que requer altas pressões de hidrogênio e demanda altos custos operacionais. Recentes estudos têm relatado a hidrogenólise do glicerol a 1,2-PDO em fase vapor, utilizando principalmente catalisadores a base de cobre. O principal catalisador empregado na hidrogenólise do glicerol tanto na fase liquida como vapor é a cromita de cobre, CuCr2O4. Neste trabalho, a atividade catalítica da cromita de cobre foi avaliada em fase vapor, estudando três fatores: a estruturação da cromita de cobre por diferentes temperaturas de calcinação (500-800°C); mudanças es truturais provocadas por diferentes métodos de síntese (Combustão e Pechini); e a modificação da estrutura da cromita pela introdução do alumínio em substituição do cromo. Todos os catalisadores foram caracterizados por DRX, FTIR, EDX, BET, TPR-H2 e área metálica do cobre. A hidrogenólise do glicerol em fase vapor se mostrou promissora e os resultados obtidos indicaram que a fase cromita de cobre propicia uma maior estabilidade para a fase ativa o cobre metálico. O aumento da área metálica do cobre é influenciado diretamente pelo método de síntese, maximizando a hidrogenólise. A introdução do alumínio provocou o aumento da seletividade ao propanodiol pela melhora nas propriedades texturais. / Salvador
100

Coprodutos do biodiesel na alimentação de cordeiros / Biodiesel coproducts at feeding of lambs

Romanzini, Eliéder Prates [UNESP] 29 February 2016 (has links)
Submitted by Eliéder Prates Romanzini null (elieder89@hotmail.com) on 2016-03-11T14:31:09Z No. of bitstreams: 1 Dissertação_FINAL.pdf: 974703 bytes, checksum: 4befa35fc8c2f6b60e5c8c624d1c4965 (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-03-14T17:30:20Z (GMT) No. of bitstreams: 1 romanzini_ep_me_jabo.pdf: 974703 bytes, checksum: 4befa35fc8c2f6b60e5c8c624d1c4965 (MD5) / Made available in DSpace on 2016-03-14T17:30:20Z (GMT). No. of bitstreams: 1 romanzini_ep_me_jabo.pdf: 974703 bytes, checksum: 4befa35fc8c2f6b60e5c8c624d1c4965 (MD5) Previous issue date: 2016-02-29 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O objetivo desta pesquisa foi avaliar a digestibilidade aparente da matéria seca e dos nutrientes, o balanço aparente de nitrogênio, a produção de gases in vitro com a determinação dos ácidos graxos de cadeia curta, o desempenho, os parâmetros quantitativos in vivo e da carcaça, assim como a avaliação econômica de dietas com coprodutos do biodiesel na alimentação de cordeiros. Para o ensaio in vivo utilizaram-se 40 cordeiros Ile de France, recém-desmamados, pesando 17,15 ± 1,56 kg e para o in vitro 4 cordeiros Santa Inês, com 31,2 ± 0,75 kg de peso corporal, como doadores de fluido ruminal. Os tratamentos foram compostos por dietas com 40% de silagem de milho e 60% dos concentrados: Cont: concentrado padrão; FAm: concentrado com 20% de farelo de amendoim na matéria seca; Gli: concentrado com 25% de glicerina bruta na matéria seca e FGl: concentrado com 10% de farelo de amendoim e 12,5% de glicerina bruta na matéria seca. O delineamento experimental foi inteiramente casualizado em ambos os ensaios, com uso do procedimento GLM do programa SAS (2003), sendo as comparações das médias dos tratamentos feitas pelo teste de Tukey a 5% de significância. O consumo de nutrientes, o balanço aparente de nitrogênio e as quantificações de metano e ácidos graxos de cadeia curta foram semelhantes. A inclusão de glicerina bruta resultou em maior (P<0,05) digestibilidade aparente da matéria seca (79,87%) e de nutrientes, exceto extrato etéreo (80,82%), se comparada às demais dietas. O desempenho dos cordeiros, as características quantitativas da carcaça e medidas no músculo Longissimus thoracis não diferiram (P>0,05) entre as dietas, enquanto que a largura da garupa in vivo, a compacidade corporal, o perímetro do tórax na carcaça e o peso dos cortes (paleta e lombo) diferiram (P<0,05). Na análise da alteração do rendimento líquido o farelo de amendoim resultou em maior valor econômico (R$ 16,23.cab-1). A inclusão de glicerina bruta foi uma alternativa nutricional viável devido às melhoras na digestibilidade aparente. Os coprodutos utilizados reduziram o custo total da dieta, sendo que a inclusão de 20% de farelo de amendoim na matéria seca foi o tratamento com maior ganho econômico. / The objective this study was to evaluate the apparent digestibility of dry matter and nutrients, the nitrogen balance, the total in vitro gas production with shortchain fat acids determination, the performance, the quantitative parameters in vivo and in carcass, as the economic evaluation of diets with biodiesel coproducts in feeding lambs. For in vivo trial were used 40 Ile de France lambs, weaning, weighing 17.15 ± 1.56 kg and for in vitro trial four Santa Inês lambs, with 31.2 ± 0.75 kg of body weight, as suppliers of ruminal fluid. The treatments were composed for diets with 40% of corn silage and 60% of concentrates: Cont: standard concentrate; PMe: concentrate with 20% of peanut meal on dry matter; CGl: concentrate with 25% of crude glycerin on dry matter and PGl: concentrate with 10% of peanut meal and 12.5% of crude glycerin on dry matter. The experimental design was completely randomized in both trials, with use of GLM procedure of SAS (2003) software and comparisons between the treatments means were made by Tukey test at 5 % significance. The nutrients intake, the nitrogen balance and concentration of methane and short-chain fat acids were similar. The crude glycerin inclusion resulted higher (P<0.05) apparent digestibility of dry matter (79.87%) and nutrients, except ether extract (80.82%), compared to other diets. The lambs performance, the carcass characteristics quantitatives and measurement in Longissimus thoracis muscle were not different (P>0.05) between the diets, while the rump width in vivo, the body compactness, the chest girth in carcass and the cuts weigh (shoulder and back) were changed (P<0.05). In evaluate of change in net income the peanut meal resulted in higher economic value (R$ 16.23.head-1 ). The inclusion of crude glycerin was the viable nutritional alternative due the improvements on apparent digestibility. The coproducts used decreased the total costs of diet, being the inclusion of 20% of peanut meal on dry matter was treatment with higher economic gain. / FAPESP: 2013/23495-5 / CNPq:131978/2014-4

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