• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2
  • 2
  • 1
  • Tagged with
  • 5
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 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

Optimalizace kultivačních podmínek při množení česneku kuchyňského metodou in vitro

Spálovský, Miroslav January 2013 (has links)
No description available.
2

Performance of a solid propellent rocket

Yassin, Jamal Saleh January 1986 (has links)
No description available.
3

Exogenní a endogenní faktory tvorby cibule u česneku kuchyňského v podmínkách in vitro

Staňková, Zuzana January 2014 (has links)
In this thesis the study of effects exogenous and engoenous factors on garlic (Allium sativum L.) plats in vitro was done. Species 'Lukan', 'Lan', 'Bjetin', 'Slavin' a 'Havran' were observed with their reactions to growth regulators added to MS medium with 0,5 mg.l-1 2iP, 0,2 mg.l-1 NAA - variants with PP 333, ABA, CEPA and increased sucrose content. During the growth of the plant, ethylene, ethane and CO2 concentrations in culturing bulbs were determined and plant growth was monitored, namely bulb creation and mass increase. At the end of the experiment, the stability of donor plant and explant was verified using DNA markers in 'Lan' and 'Lukan' species.
4

Din?mica populacional da entomofauna deterioradora associada a tr?s ambientes no Sistema Integrado de Produ??o Agroecol?gica (SIPA) em Serop?dica, RJ / Population dynamics of deteriorater entomofauna associated with three environments in the Integrated Agroecological Production System (IAPS) in Serop?dica/RJ

SANTOS, Tamires Medeiros dos 01 March 2016 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2016-10-20T17:01:43Z No. of bitstreams: 1 2016 - Tamires Medeiros do Santos.pdf: 5083938 bytes, checksum: 468695a43a5e90373cf9817865775cc6 (MD5) / Made available in DSpace on 2016-10-20T17:01:43Z (GMT). No. of bitstreams: 1 2016 - Tamires Medeiros do Santos.pdf: 5083938 bytes, checksum: 468695a43a5e90373cf9817865775cc6 (MD5) Previous issue date: 2016-03-01 / CAPES / The searching for development of sustainable agricultural systems has shown satisfactory results from economic, social and agronomic perspectives. However, it is necessary to evaluate these systems about their impacts on the environment. The knowledge of insect fauna is essential in monitoring the impacts caused by anthropic action, and the Coleoptera order, because it?s the group with biggest richness, has been the focus of many studies that evaluate environmental conditions. Given the above, the objective of this study was to analyze the occurrence of beetles captured per impact trap in the period from November 2014 to November 2015, in three environments with different ecological characteristics, and assess the influence of climatic variables in the occurrence of Scolytinae group. In order to conduct the study, the chosen experimental area is located in the Integrated Agroecological Production System (IAPS), in the municipality of Serop?dica/RJ. Were selected, inside the IAPS, three distinct environments: organic coffee production (OC), agroforestry (AFS) and organic coffee (FF). Climatic data was obtained by an automatic station, of the National Institute of Meteorology (INMET), located in Serop?dica, named Agricultural Ecology Station. In each environment, there were set four ethanolic semifunil model traps. The traps were kept in the field in the period from November 2014 to November 2015, and every seven days the storers containers went replaced and the attractive baits were renewed using commercial ethanol (alcohol 96 ?). The samples were forwarded to the Laboratory of Wood Deterioration and Forestry Entomology, at the Rural Federal University of Rio de Janeiro ? UFRRJ, to perform the triage. The insects were separated by trap and their respective area where they were collected, and then identified. All insects collected were quantified and only the coleoptera were identified at the level of family and subfamily. However, four groups of borers beetles (Cerambycidae, Bostrichidae and, Curculionidae: Platypodinae and Scolytinae) were evaluated separately. The highest number of insects was found in the AFS, followed by the organic coffee and the agroforestry system. Nearly 75% of the trapped borers beetles were Scolytinae. The agroforestry system was the environment with more coleoborers, due to the management carried out in the area, because there is a greater diversity of plant species, thus requiring constant maintenance. Seasonality influenced in the number of Scolytinae in the three environments. The temperature, atmospheric pressure and wind speed influenced the Scolytinae fluctuation only in the organic coffee and the agroforestry system, considering that the composition of the forest fragment provides favorable conditions for its microclimate stability. / A busca por desenvolvimento de sistemas agr?colas sustent?veis tem demonstrado resultados satisfat?rios do ponto de vista econ?mico, social e agron?mico. Entretanto ? necess?rio avaliar tais sistemas quanto aos impactos gerados ao meio ambiente. O conhecimento da entomofauna ? essencial no acompanhamento de impactos causados pela a??o antr?pica e, a Ordem Coleoptera, por ser o grupo de maior riqueza, tem sido alvo de muitos estudos para avalia??o de condi??es ambientais. Diante disto, o objetivo deste trabalho foi analisar a ocorr?ncia de cole?pteros capturados por armadilha de impacto, no per?odo de novembro de 2014 a novembro de 2015, em tr?s ambientes com caracter?sticas ecol?gicas distintas e, avaliar a influ?ncia de vari?veis clim?ticas na ocorr?ncia do grupo Scolytinae. Para a realiza??o do estudo, a ?rea experimental escolhida est? localizada no Sistema Integrado de Produ??o Agroecol?gica (SIPA), no munic?pio de Serop?dica, RJ. Foram selecionados dentro do SIPA tr?s ambientes distintos: produ??o de caf? org?nico (CO), sistema agroflorestal (SAF) e fragmento florestal (FF). Os dados clim?ticos foram obtidos pela esta??o autom?tica do Instituto Nacional de Meteorologia (INMET) localizada em Serop?dica, esta??o Ecologia agr?cola. Em cada ambiente foram instaladas quatro armadilhas etan?licas modelo Semifunil. As armadilhas foram mantidas no campo no per?odo de novembro de 2014 a novembro de 2015 e, a cada sete dias os recipientes armazenadores foram substitu?dos e as iscas atrativas renovadas com etanol comercial (?lcool 96?). As amostras foram encaminhadas ao Laborat?rio Deteriora??o da madeira e Entomologia Florestal da Universidade Federal Rural do Rio de Janeiro - UFRRJ para a realiza??o da triagem. Os insetos foram separados por ?rea e armadilha, de onde foram coletados e, em seguida, identificados. Todos os insetos coletados foram quantificados e, os cole?pteros foram identificados em n?vel de Fam?lia e Subfam?lia. No entanto, quatro grupos de cole?pteros broqueadores (Cerambycidae, Bostrichidae e, Curculionidae: Platypodinae e Scolytinae) foram avaliadas separadamente. O maior n?mero de cole?pteros foi encontrado no sistema agroflorestal seguido do caf? org?nico e do fragmento florestal. Cerca de 75% dos cole?pteros broqueadores registrados foram Scolytinae. O sistema agroflorestal foi o ambiente com maior n?mero de cole?pteros broqueadores, devido ao manejo realizado na ?rea, pois ocorre maior diversidade de esp?cies vegetais, consequentemente, exigindo manuten??o constante. A sazonalidade influenciou no n?mero de Scolytinae nos tr?s ambientes. A temperatura, a press?o atmosf?rica e a velocidade do vento influenciaram na flutua??o de escolit?neos apenas no caf? org?nico e no sistema agroflorestal, considerando que a composi??o do fragmento florestal proporciona condi??es favor?veis para a estabilidade microclim?tica.
5

S?ntese, caracteriza??o e aplica??o de LaSBA-15 e como catalisador para obten??o de biodiesel de soja via rota et?lica

Ara?jo, Larissa Cicianny Luz Ferreira de 04 July 2011 (has links)
Made available in DSpace on 2014-12-17T14:08:46Z (GMT). No. of bitstreams: 1 LarissaCLA_DISSERT.pdf: 2411784 bytes, checksum: bc6175bf8ed881abf12e8c0d17d59264 (MD5) Previous issue date: 2011-07-04 / Biodiesel is an alternative fuel, renewable, biodegradable and nontoxic. The transesterification of vegetable oils or animal fat with alcohol is most common form of production of this fuel. The procedure for production of biodiesel occurs most commonly through the transesterification reaction in which catalysts are used to accelerate and increase their income and may be basic, acid or enzyme. The use of homogeneous catalysis requires specific conditions and purification steps of the reaction products (alkyl ester and glycerol) and removal of the catalyst at the end of the reaction. As an alternative to improve the yield of the transesterification reaction, minimize the cost of production is that many studies are being conducted with the application of heterogeneous catalysis. The use of nano-structured materials as catalysts in the production of biodiesel is a biofuel alternative for a similar to mineral diesel. Although slower, can esterify transesterified triglycerides and free fatty acids and suffer little influence of water, which may be present in the raw material. This study aimed at the synthesis, characterization and application of nano-structured materials as catalysts in the transesterification reaction of soybean oil to produce biodiesel by ethylic route. The type material containing SBA-15 mesoporous lanthanum embedded within rightly Si / La = 50 was used catalyst. Solid samples were characterized by X-ray diffraction, thermogravimetric analysis, infrared spectroscopy, nitrogen adsorption and desorption. For the transesterification process, we used a molar ratio of 20:1 alcohol and oil with 0.250 g of catalyst at 60?C and times of 6 hours of reaction. It was determined the content of ethyl esters by H-NMR analysis and gas chromatography. It was found that the variable of conversion obtained was 80%, showing a good catalytic activity LaSBA-15 in the transesterification of vegetable oils via ethylic route / O biodiesel ? um combust?vel alternativo, renov?vel, biodegrad?vel e n?o t?xico. A transesterifica??o dos ?leos vegetais ou gordura animal com ?lcool ? a forma mais usual de produ??o desse combust?vel. O procedimento de produ??o de biodiesel ocorre mais comumente atrav?s da rea??o de transesterifica??o, na qual se utiliza catalisadores para acelerar e aumentar seu rendimento, podendo ser b?sico, ?cido ou enzim?tico. O uso da cat?lise homog?nea requer condi??es e etapas espec?ficas de purifica??o dos produtos da rea??o (?ster alqu?licos e glicerol) e remo??o do catalisador ao t?rmino da rea??o. Como alternativa para melhorar o rendimento da rea??o de transesterifica??o, minimizar os custos com a produ??o ? que muitos estudos est?o sendo realizados com aplica??o de cat?lise heterog?nea. O uso de materiais nano-estruturados como catalisadores na produ??o de biodiesel ? uma alternativa para obter um biocombust?vel semelhante ao diesel mineral. Mesmo sendo mais lentos, conseguem transesterificar os triglicer?deos e esterificar os ?cidos graxos livres, al?m de sofrerem pouca influ?ncia da ?gua, que possa estar presente na mat?riaprima. Este trabalho teve como objetivo a s?ntese, caracteriza??o e aplica??o de materiais nano-estruturados como catalisadores na rea??o de transesterifica??o de ?leo de soja, para obten??o de biodiesel pela rota et?lica. O material do tipo SBA-15 contendo lant?nio incorporado na estrutura mesoporosa, com raz?o Si/La=50, foi utilizado como catalisador. As amostras s?lidas foram caracterizadas por difra??o de raios-X, an?lise termogravim?trica, espectroscopia na regi?o do infravermelho, adsor??o e dessor??o de nitrog?nio. Para o processo de transesterifica??o, utilizou-se uma raz?o molar entre ?lcool e ?leo de 20:1 com 0,250 g de catalisador, temperatura de 60?C e tempos de 6 horas de rea??o. Determinou-se o teor de ?steres et?licos pela an?lise de H-RMN e cromatografia a g?s. Foi verificado que a vari?vel de convers?o obtida foi de 80%, mostrando uma boa atividade catal?tica do LaSBA- 15 na transesterifica??o do ?leo de soja via rota et?lica

Page generated in 0.0351 seconds