• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 3
  • Tagged with
  • 4
  • 4
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 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.
1

ParÃmentros fÃsicos, perfil fermentativo e composiÃÃo quÃmica de silagem de Pennisetum purpureum com feno de GliricÃdia sepium / Physical parameters, fermentation characteristics and chemical composition of Pennisetum purpureum silage with Gliricidia sepium hay

Weverton Filgueira Pacheco 19 July 2010 (has links)
FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / Objetivou-se atravÃs desse trabalho, avaliar as caracterÃsticas fÃsicas, o perfil fermentativo e a composiÃÃo quÃmica de silagem de capim-elefante com feno de gliricÃdia, utilizando-se mini-silos experimentais em delineamento inteiramente casualizado, com cinco tratamentos: 100% capim-elefante; 95% de capim-elefante com 5% de feno de gliricÃdia; 90% de capim-elefante com 10% de feno de gliricÃdia; 80% de capim-elefante com 20% de feno de gliricÃdia e 60% de capim-elefante com 40% de feno de gliricÃdia, com cinco repetiÃÃes por tratamento. Foram determinados pH, nitrogÃnio amoniacal (NA), capacidade tampÃo (CT), massa especÃfica (ME), massa especÃfica seca (MES), produÃÃo de efluentes (PE), produÃÃo de gases (PG), recuperaÃÃo de matÃria seca (RMS), matÃria seca (MS), matÃria orgÃnica (MO), proteÃna bruta (PB), fibra em detergente neutro (FDN), fibra em detergente Ãcido (FDA), hemicelulose (HEM), celulose (CEL), lignina (LG), extrato etÃreo (EE) e carboidratos totais (CHOT). A adiÃÃo de feno de gliricÃdia nas silagens de capim-elefante causou efeito linear para as variÃveis MS, MES e CT. Houve resposta quadrÃtica para as variÃveis ME, PE, RMS, MO, PB, FDN, HEM, LG e CHOT. As silagens apresentaram pH variando de 4,18 para silagens sem adiÃÃo de feno a 4,38 para silagens com 40% de adiÃÃo de feno. O teor de NA foi maior para silagens sem adiÃÃo de feno (12,24%) e menor em silagens com 40% de adiÃÃo de feno (1,40%). As silagens sem adiÃÃo de feno apresentaram menor capacidade tampÃo (41,69 n.e.mg/100g MS) e as silagens com 40% de adiÃÃo de feno apresentaram maior valor de capacidade tampÃo (52,45 n.e.mg/100g MS). As silagens sem adiÃÃo de feno apresentaram menores MS (14,96%), enquanto que as silagens com 40% de adiÃÃo de feno de gliricÃdia apresentaram maiores teores de MS (43,84%). Os teores de PB variaram de 5,36 % (sem adiÃÃo de feno) a 8,20 % (40% de adiÃÃo de feno). Com relaÃÃo aos teores de FDN, observou-se que as silagens com adiÃÃo 40% de feno apresentaram os menores teores de FDN (46,73%). Os teores de CEL variaram de 19,54% (40% de adiÃÃo feno) a 31,14% (sem adiÃÃo de feno). Os teores de CHOT das silagens variaram de 74,45% (40% de feno) a 81,33% (0% de feno). Com base nos resultados obtidos, pode-se concluir que a adiÃÃo de feno de gliricÃdia na ensilagem do capim elefante melhorou a sua composiÃÃo quÃmica, as caracterÃsticas fÃsicas e o perfil fermentativo das silagens. / The objective was to evaluated the physical parameters, the fermentation characteristics and chemical composition of the elephant grass silage with gliricidia hay, using experimental mini-silos in a randomized design with five treatments: 100% elephant grass; 95% elephant grass with 5% gliricÃdia hay; 90% elephant grass with 10% gliricÃdia hay; 80% elephant grass with 20% gliricÃdia hay and 60% elephant grass with 40% gliricidia hay, with five replicates per treatment. Were determined pH, ammonia nitrogen (AN), buffering capacity (BC), specific mass (SM), dry specific mass (DSM), effluent yield (EY), gas production (GP), dry matter recovery (DMR), dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), hemicellulose (HEM), cellulose (CEL), lignin (LG) , ether extract (EE) and total carbohydrates (TC). The addition of gliricÃdia hay in elephant grass silage increased linearly the DM, DMS and BC. There was a quadratic for SM, EY, DMR, OM, CP, NDF, HEM, LG and TC. The silages presented pH varying from 4.18 for silage without hay to 4.38 for silages with 40% of the hay. The content of AN was higher for silages without hay (12.24%) and lowest in silages with 40% of the hay (1.40%). The silage without hay had presented lower buffering capacity (41.69 meq/100g of DM) and highest buffering capacity (52.45 meq/100g of MS), for silage with 40% of the hay. The silage without hay had lower DM (14.96%) and higher DM (43.84%) for silage with 40% of gliricidia hay. The CEL varying from 19.54% (40% of the hay) to 31.14% (without hay). The silage presented TC varying from 74.45% (40% hay) to 81.33 % (without hay). It can be concluded that the addition of gliricidia hay in the elephant grass silage improved the chemical composition, the physical parameters and the fermentation characteristics of the elephant grass silage.
2

UTILIZAÇÃO DE DIFERENTES MATERIAIS COMO ADSORVENTES NA REMOÇÃO DE NITROGÊNIO AMONIACAL / DIFFERENT MATERIALS AS ADSORBENTS FOR THE REMOVAL OF NITROGEN AMMONIACAL

Silva, Naiana Pommerening da 09 January 2015 (has links)
The discharge of effluents without proper treatment, in water bodies has been one of the main environmental problems in aquatic systems. Macronutrients launched, such as nitrogen can cause the effect known as eutrophication leading to deterioration of the receiving body, smell, dissolved oxygen reduction, etc. Therefore, it is necessary to the viability of alternative processes to minimize the impact on the environment. Among them we can highlight the adsorption. In this work was up to evaluate the potential of ammonia nitrogen removal of Typha domingensis (Taboa) and activated carbon adsorption process by using synthetic wastewater produced from ammonia chloride solution (NH4Cl). Were used as adsorbents activated carbon, shoot and rhizome the Typha sp. The adsorption experiments were carried out in Wagner shaker with NH4 concentrations of 80, 160, 250 and 350 mg/L; solid sorbent concentration of 4 and 8 g/l and the residence time of 15, 30, 45, 60, 75, 90, 105 and 120 min., stirred at a speed of 15 rpm at a temperature 20±2 °C. The initial and resulting concentration was determined by spectrophotometry UV-VIS technique the method Nessler described in Vogel 1991. Was determined specific area and apparent density of the materials. The adsorption isotherms were generated in the models of Langmuir and Freundlich. The values found for specific surface area activated carbon, leaf, root and bagasse were 1357, 8270, 6708 and 10613 m²/g respectively. The resulting values of bulk density for activated carbon, leaf, root and bagasse were 0.885; 0.15; 0.27 and 0.24 g/cm³ respectively. There was little variation in the final concentration of ammonia in relation to the contact time for both materials. Leaf, root and bagasse showed no removal of ammonia at low concentrations (80 and 160 mg/L), so increasing the final concentration of the solution being added to the mass of 8 g/l. Positive results were found in concentrations of 250 and 350 mg/L, with a mean removal the 6 % for the materials. The activated carbon had removed 14 % at a concentration of 80 mg/L weight 4 g/l. The ammonia removal is greater with increasing the amount of activated carbon (8 g/L), since the plant largest removals was the mass 4 g/l of adsorbent. The removal efficiency is small for the temperature used in the experiments (20°C) and improves over the course of increasing contact time. The Freundlich model was the best fit for the activated carbon in the masses of 4 and 8 g/L, resulting correlation coefficient R² = 0.8702 and R² = 0.8936, respectively. However, the activated carbon can be used as an adsorbent for the removal of ammonia in domestic wastewater. The plant did not show satisfactory results ammonia removal at lower concentrations and is not suitable for use in sewage treatment. / O lançamento de efluentes, sem o devido tratamento, em corpos hídricos tem sido um dos principais problemas ambientais dos sistemas aquáticos. Os macronutrientes lançados, como o nitrogênio pode causar o efeito conhecido como eutrofização levando a deterioração do corpo receptor, odor, redução de oxigênio dissolvido, etc. Diante disso, faz-se necessário a viabilização de processos alternativos visando minimizar o impacto no meio ambiente. Entre eles pode-se destacar a adsorção. Neste trabalho teve-se como objetivo avaliar o potencial de remoção de nitrogênio amoniacal da Typha domingensis (Taboa) e do carvão ativado, por processo de adsorção, utilizando solução de cloreto de amônia (NH4Cl). Foram utilizados como adsorventes o carvão ativado, a parte aérea e o rizoma raízes da Typha sp. Os ensaios de adsorção foram realizados no agitador de Wagner com as concentrações de NH4 de 80, 160, 250 e 350 mg/L; concentração de sólido sorvente de 4 e 8 g/L e tempo de residência de 15, 30, 45, 60, 75, 90, 105 e 120 min., sob agitação com velocidade de 15 rpm, e temperatura de 20±2°C. A concentração inicial e resultante foi determinada pela técnica de espectrofotometria UV-VIS, pelo método de Nessler. Foi determinada a área específica e densidade aparente dos materiais. Foram geradas as isotermas de adsorção nos modelos de Langmuir e Freundlich. Os valores encontrados de área superficial específica para o carvão ativado, folha, raiz e bagaço foram de 1357, 8270, 6708 e 10613 m²/g respectivamente. Os valores resultantes de densidade aparente para carvão ativado, folha, raiz e bagaço foram 0,885; 0,15; 0,27 e 0,24 g/cm³ respectivamente. Houve pouca variação da concentração final de amônia em relação ao tempo de contato para ambos os materiais. Folha, raiz e bagaço não apresentaram remoção de amônia nas menores concentrações (80 e 160 mg/L) e, sim aumento da concentração final da solução, sendo maior para a massa de 8 g/L. Resultados positivos para estes materiais foram encontrados nas concentrações de 250 e 350 mg/L, apresentando remoção média de 6% para os materiais. O carvão ativado apresentou remoção de 14% na concentração de 80 mg/L com massa de 4 g/L. A remoção de amônia é maior com o aumento da quantidade de carvão ativado (8 g/L), já na planta as maiores remoções foram na massa de 4 g/L de adsorvente. A eficiência de remoção é pequena para a temperatura utilizada nos experimentos (20°C) e melhora com o decorrer do aumento do tempo de contato. O modelo de Freundlich foi o que melhor se ajustou para o carvão ativado nas massas de 4 e 8 g/L, obtendo coeficiente de correlação R² = 0,8702 e R² = 0,8936, respectivamente. Contudo, o carvão ativado pode ser utilizado como adsorvente na remoção de nitrogênio amoniacal em esgoto doméstico. A planta não mostrou resultados satisfatórios de remoção de amônia nas concentrações mais baixas, não sendo indicada para uso em tratamento de esgoto doméstico.
3

Grazing and Feeding Management of Lactating Dairy Cows

Soriano, Felix Diego 12 August 1998 (has links)
Two studies were conducted during the grazing season of 1997. Study 1 consisted of three Experiments, and the objectives were to compare milk production and composition, body weight change and body condition score, and to determine time patterns of grazing between cows supplemented with different forms and amounts of corn. Also rumen fermentation parameters were measured in cows supplemented with two different types of corn. In study 2, milk yield was measured when grazing pasture was supplemented to lactating Holstein cows fed a typical TMR diet. Predominantly orchardgrass pastures with lesser amounts of white clover and Kentucky bluegrass were grazed during both studies. In Experiment 1, 36 Holstein cows were supplemented either with 6, 6, 6, or 4 kg/d DM of high moisture corn, coarsely ground corn, finely ground corn, or high moisture corn in two equal feedings, respectively. Milk yield was similar (30.3 kg/d) among treatments. Milk protein (2.97%) and MUN (14.7 mg/dl) did not differ among treatments. Body weight change and body condition score change were similar among treatments (23.1 kg and -0.24). During Experiment 2, four rumen-cannulated cows in mid-lactation were supplemented 6 kg/d DM of either coarsely ground corn or high moisture corn in two equal feedings. After the p.m. milking, ruminal pH was measured and rumen fluid samples were collected to determine ammonia N and VFA. While grazing, this was repeated at 0.5, 1, 2, 3,...8 h post-corn feeding (0 h). Ruminal pH was similar for both corn supplements and was lowest (5.9 and 5.8) at 5 and 8 h, respectively. Rumen ammonia N concentrations started to increase approximately 2 h after cows began grazing, reaching maximum levels 5 h later. In Experiment 3, the number of cows grazing, lying, or standing were recorded every half hour, for two consecutive days, while grazing. Cows grazed an average of 6.4 h/d, 4.1 h in the afternoon and 2.3 h in the morning. Similarity in milk production, milk composition, BW change, and BCS between treatments indicates that the quality and availability of pasture permitted equal response regardless of the type or amount of corn supplemented. Fifty four Holstein cows in mid lactation were used in Study 2. Cows were fed either a TMR diet only, or were fed TMR during half of the day (after the a.m. or p.m. milking according to the treatment) and supplemented with grazing pasture during the other half of the day. Milk production was slightly but significantly higher for cows on the TMR treatment (29.1 vs. 28.2 and 27.6). No significant difference between treatments was observed in FCM (27.7 kg/d), and milk fat (3.47) and protein percentage (3.23). While BW change did not differ among treatments (25.7 kg), body condition score increased more in cows fed only a TMR diet (0.14 vs. -0.06 and 0.01). The TMR intake was significantly different between treatments, being highest for cows on the TMR treatment and lowest for cows grazing after the p.m. milking (26.6 vs. 20.3 vs. 17.5 kg/d DM). Income over feed cost differed between treatments, and was approximately 15.3% higher for cows supplemented with high quality pasture during the afternoon compared to cows on TMR. Dairy farmers may obtain economical benefits by practicing this type of management during the grazing season with little effect on milk yield. / Master of Science
4

Parâmentros físicos, perfil fermentativo e composição química de silagem de Pennisetum purpureum com feno de Gliricídia sepium / Physical parameters, fermentation characteristics and chemical composition of Pennisetum purpureum silage with Gliricidia sepium hay

Pacheco, Weverton Filgueira January 2010 (has links)
PACHECO, Weverton Filgueira. Parâmentros físicos, perfil fermentativo e composição química de silagem de Pennisetum purpureum com feno de Gliricídia sepium. 2010. x, 46 f. : Dissertação (Mestrado) - Universidade Federal do Ceará, Centro de Ciências, Departamento de Zootecnia, Programa de Pós-Graduação em Zootecnia. Fortaleza-CE, 2010. / Submitted by Eric Santiago (erichhcl@gmail.com) on 2016-08-03T15:03:58Z No. of bitstreams: 1 2010_dis_wfpacheco.pdf: 263740 bytes, checksum: bcb5a344bdf5eb7031ac3bea3631b2fa (MD5) / Approved for entry into archive by Nádja Goes (nmoraissoares@gmail.com) on 2016-08-03T15:38:02Z (GMT) No. of bitstreams: 1 2010_dis_wfpacheco.pdf: 263740 bytes, checksum: bcb5a344bdf5eb7031ac3bea3631b2fa (MD5) / Made available in DSpace on 2016-08-03T15:38:02Z (GMT). No. of bitstreams: 1 2010_dis_wfpacheco.pdf: 263740 bytes, checksum: bcb5a344bdf5eb7031ac3bea3631b2fa (MD5) Previous issue date: 2010 / The objective was to evaluated the physical parameters, the fermentation characteristics and chemical composition of the elephant grass silage with gliricidia hay, using experimental mini-silos in a randomized design with five treatments: 100% elephant grass; 95% elephant grass with 5% gliricídia hay; 90% elephant grass with 10% gliricídia hay; 80% elephant grass with 20% gliricídia hay and 60% elephant grass with 40% gliricidia hay, with five replicates per treatment. Were determined pH, ammonia nitrogen (AN), buffering capacity (BC), specific mass (SM), dry specific mass (DSM), effluent yield (EY), gas production (GP), dry matter recovery (DMR), dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), hemicellulose (HEM), cellulose (CEL), lignin (LG) , ether extract (EE) and total carbohydrates (TC). The addition of gliricídia hay in elephant grass silage increased linearly the DM, DMS and BC. There was a quadratic for SM, EY, DMR, OM, CP, NDF, HEM, LG and TC. The silages presented pH varying from 4.18 for silage without hay to 4.38 for silages with 40% of the hay. The content of AN was higher for silages without hay (12.24%) and lowest in silages with 40% of the hay (1.40%). The silage without hay had presented lower buffering capacity (41.69 meq/100g of DM) and highest buffering capacity (52.45 meq/100g of MS), for silage with 40% of the hay. The silage without hay had lower DM (14.96%) and higher DM (43.84%) for silage with 40% of gliricidia hay. The CEL varying from 19.54% (40% of the hay) to 31.14% (without hay). The silage presented TC varying from 74.45% (40% hay) to 81.33 % (without hay). It can be concluded that the addition of gliricidia hay in the elephant grass silage improved the chemical composition, the physical parameters and the fermentation characteristics of the elephant grass silage. / Objetivou-se através desse trabalho, avaliar as características físicas, o perfil fermentativo e a composição química de silagem de capim-elefante com feno de gliricídia, utilizando-se mini-silos experimentais em delineamento inteiramente casualizado, com cinco tratamentos: 100% capim-elefante; 95% de capim-elefante com 5% de feno de gliricídia; 90% de capim-elefante com 10% de feno de gliricídia; 80% de capim-elefante com 20% de feno de gliricídia e 60% de capim-elefante com 40% de feno de gliricídia, com cinco repetições por tratamento. Foram determinados pH, nitrogênio amoniacal (NA), capacidade tampão (CT), massa específica (ME), massa específica seca (MES), produção de efluentes (PE), produção de gases (PG), recuperação de matéria seca (RMS), matéria seca (MS), matéria orgânica (MO), proteína bruta (PB), fibra em detergente neutro (FDN), fibra em detergente ácido (FDA), hemicelulose (HEM), celulose (CEL), lignina (LG), extrato etéreo (EE) e carboidratos totais (CHOT). A adição de feno de gliricídia nas silagens de capim-elefante causou efeito linear para as variáveis MS, MES e CT. Houve resposta quadrática para as variáveis ME, PE, RMS, MO, PB, FDN, HEM, LG e CHOT. As silagens apresentaram pH variando de 4,18 para silagens sem adição de feno a 4,38 para silagens com 40% de adição de feno. O teor de NA foi maior para silagens sem adição de feno (12,24%) e menor em silagens com 40% de adição de feno (1,40%). As silagens sem adição de feno apresentaram menor capacidade tampão (41,69 n.e.mg/100g MS) e as silagens com 40% de adição de feno apresentaram maior valor de capacidade tampão (52,45 n.e.mg/100g MS). As silagens sem adição de feno apresentaram menores MS (14,96%), enquanto que as silagens com 40% de adição de feno de gliricídia apresentaram maiores teores de MS (43,84%). Os teores de PB variaram de 5,36 % (sem adição de feno) a 8,20 % (40% de adição de feno). Com relação aos teores de FDN, observou-se que as silagens com adição 40% de feno apresentaram os menores teores de FDN (46,73%). Os teores de CEL variaram de 19,54% (40% de adição feno) a 31,14% (sem adição de feno). Os teores de CHOT das silagens variaram de 74,45% (40% de feno) a 81,33% (0% de feno). Com base nos resultados obtidos, pode-se concluir que a adição de feno de gliricídia na ensilagem do capim elefante melhorou a sua composição química, as características físicas e o perfil fermentativo das silagens.

Page generated in 0.0349 seconds