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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.
1

Incorporação de óleo essencial de manjericão em filmes biodegradáveis à base de galactomanana e óleo de canola / Essential oil of basil incorporation into biodegradable films galactomannan base and canola oil

Oliveira Filho, Rosueti Diógenes de January 2015 (has links)
OLIVEIRA FILHO, Rosueti Diógenes de. Incorporação de óleo essencial de manjericão em filmes biodegradáveis à base de galactomanana e óleo de canola. 2015. 77 f. Dissertação (mestrado em bioquímica)- Universidade Federal do Ceará, Fortaleza-CE, 2015 / Submitted by Elineudson Ribeiro (elineudsonr@gmail.com) on 2016-03-22T18:12:30Z No. of bitstreams: 1 2016_rdoliveirafilho.pdf: 1493866 bytes, checksum: bece9362961e66588fbfbaff693bdd5d (MD5) / Approved for entry into archive by José Jairo Viana de Sousa (jairo@ufc.br) on 2016-05-18T18:27:40Z (GMT) No. of bitstreams: 1 2016_rdoliveirafilho.pdf: 1493866 bytes, checksum: bece9362961e66588fbfbaff693bdd5d (MD5) / Made available in DSpace on 2016-05-18T18:27:40Z (GMT). No. of bitstreams: 1 2016_rdoliveirafilho.pdf: 1493866 bytes, checksum: bece9362961e66588fbfbaff693bdd5d (MD5) Previous issue date: 2015 / Biodegradable Packaging are used in foods as films or coatings formed by plant macromolecules such as animal, ensuring barrier properties and can serve as a carrier for antimicrobial compounds. The cell wall polysaccharides reservation, especially hemicelluloses as galactomannans, have been used widely as biodegradable polymer matrices films. The objective of this study was to evaluate the Basil essential oil (BEO) (Ocimum basilicum) incorporation in biodegradable films based on endospermic galactomannan Delonix regia seeds and canola oil (CO) (Brassica napus L.). The galactomannan (Gal) was isolated by aqueous extraction, followed by ethanol precipitation. The yield was 12.0% with high purity presented by low nitrogen content expressed protein (0.67%). The Gal showed an average intrinsic viscosity of 3.79 dL/g and molecular weight estimated in 1,04x106 g/mol. Infrared spectra by Fourier transform (FTIR) and nuclear magnetic resonance (NMR) 1H and 13C were similar to those found in the literature for other galactomannans. The fatty acid composition of CO by gas chromatography (GC-FID) showed oleic acid (62.07%), linoleic (18.91%) and heneicosanóico (6.61%) content. The major components of BEO determined by gas chromatography coupled to mass spectrometry (GC-MS) were camphor (14.85%) and 1.8-cineole (3.48%). The films were formulated with galactomannan 1% (w/v), glycerol 0.5% (w/v) and CO at different concentrations, 0.25, 0.5 and 0.75% (w/v). The films were obtained by the solvent evaporation method (casting) and characterized as the moisture content, thickness, water vapor permeability (WVP), color and opacity. The CO promoted increase of WPV and reduced moisture content when compared to the film based only in galactomannan but no significant difference between concentrations. BEO was tested against the bacterial strains of Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Salmonella choleraesuis, Staphylococcus aureus and Candida albicans yeast by broth microdilution and showed minimum inhibitory concentration (MIC) ranging between 2.5 and 5.0 mg/ml and minimum bactericidal concentration (MBC) between 5.0 and 20.0 mg/ml. BEO was incorporated into film formulation with CO 0.5% (w/v) in different concentrations (2.5, 5.0 and 7.5 mg/ml). The antimicrobial films were obtained by casting and disks of 1 cm in diameter were excised and tested by the agar diffusion method and a contact zone and inhibition halos analyzed. S. aureus, E. coli and P. aeruginosa were sensitive to film containing BEO 5.0 mg/ml showed halos of 14, 15 and 16.3 mm, respectively. K. pneumoniae was inhibited only in the contact zone of the film, while S. choleraesuis and C. albicans were resistant to all formulations. However, the OC promoted changes in physical and barrier properties of the films of with galactomannan. BEO when incorporated into the film showed a moderate antimicrobial activity for potential application as bioactive packaging. / Embalagens biodegradáveis são coberturas utilizadas em alimentos na forma de filmes ou revestimentos, formadas por macromoléculas tanto de origem vegetal como de origem animal, que garantem propriedades de barreira e podem servir como veículo para compostos antimicrobianos. Os polissacarídeos de reserva de parede celular, principalmente as hemiceluloses como as galactomananas, vêm sendo extensamente usadas como matrizes poliméricas de filmes biodegradáveis. O objetivo deste trabalho foi avaliar a incorporação de óleo essencial de manjericão (OEM) (Ocimum basilicum) em filmes biodegradáveis à base de galactomanana endospérmica de sementes de flamboyant (Delonix regia) e óleo canola (OC) (Brassica napus L.). A Galactomanana (Gal) foi isolada por extração aquosa, seguida por precipitação em etanol. O rendimento determinado foi de 12,0%, com alto grau de pureza apresentado pelo baixo teor de nitrogênio expresso em proteína (0,67%). A Gal apresentou viscosidade intrínseca média de 3,79 dL/g e massa molar estimada de 1,04x106 g/mol. Os espectros de infravermelho por transformada de Fourier (FTIR) e ressonância magnética nuclear (RMN) de 1H e 13C foram similares aos encontrados na literatura para outras galactomananas. A composição em ácidos graxos do OC por cromatografia a gás (GC-FID) apresentou teores de ácido oleico (62,07%), linoleico (18,91%) e heneicosanóico (6,61%). Os componentes majoritários do OEM determinados por cromatografia a gás acoplado à espectrometria de massas (GC-MS) foram cânfora (14,85%) e 1,8-cineol (3,48%). Os filmes foram formulados com Gal 1% (m/v), glicerol 0,5% (m/v) e OC em diferentes concentrações, 0,25, 0,5 e 0,75% (m/v). Os filmes foram obtidos pelo método de evaporação de solvente (casting) e caracterizados quanto ao teor de umidade, espessura, permeabilidade ao vapor de água (PVA), cor e opacidade. O OC promoveu aumento de PVA e diminuição do teor de umidade quando comparado ao filme apenas de galactomanana, mas sem diferença significativa entre as concentrações. O OEM foi testado frente às cepas bacterianas de Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Salmonella choleraesuis, Staphylococcus aureus e levedura Candida albicans por microdiluição em caldo e apresentou concentração inibitória mínima (CIM) variando entre 2,5 e 5,0 mg/mL e concentração bactericida mínima (CBM) entre 5,0 e 20,0 mg/mL. A partir do filme com formulação de 0,5 % (m/v) de OC incorporou-se OEM em diferentes concentrações (2,5, 5,0 e 7,5 mg/mL). Os filmes antimicrobianos foram obtidos por casting e discos de 1 cm de diâmetro foram excisados e testados por método de difusão em ágar e a zona de contato e os halos de inibição analisados. S. aureus, E. coli e P. aeruginosa foram sensíveis ao filme contendo 5,0 mg/mL de OEM apresentando halos de 14, 15 e 16,3 mm, respectivamente. K. pneumoniae foi inibida apenas na zona de contato do filme, enquanto que S. choleraesuis e C. albicans foram resistentes à todas as formulações. Contudo, O OC promoveu alterações nas propriedades físicas e de barreira dos filmes de galactomanana e OEM quando incorporado ao filme apresentou uma atividade antimicrobiana moderada para potencial aplicação como embalagens bioativas.
2

Atividade antimicrobiana e citotoxicidade dos extratos glicólicos de Pfaffia paniculata K. E Juglans regia L. / Activity antimicrobial and citotocixity of glycol extracts of Pfaffia paniculata K AND Juglans regia L

Ramos, Lucas de Paula [UNESP] 19 December 2016 (has links)
Submitted by LUCAS DE PAULA RAMOS null (lucas93paula@hotmail.com.br) on 2017-01-20T14:09:20Z No. of bitstreams: 1 Dissertação (correções biblioteca).pdf: 4172563 bytes, checksum: 3cfab803e9b5a294021bdd02082d4128 (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2017-01-24T17:04:02Z (GMT) No. of bitstreams: 1 ramos_lp_me_sjc.pdf: 4172563 bytes, checksum: 3cfab803e9b5a294021bdd02082d4128 (MD5) / Made available in DSpace on 2017-01-24T17:04:02Z (GMT). No. of bitstreams: 1 ramos_lp_me_sjc.pdf: 4172563 bytes, checksum: 3cfab803e9b5a294021bdd02082d4128 (MD5) Previous issue date: 2016-12-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O objetivo do trabalho foi investigar se os extratos de Pfaffia paniculata K. e Juglans regia L. possuem ação antifúngica, antibacteriana e toxicidade celular, com testes in vitro. Para os testes antifúngicos foram utilizadas cepas ATCC de Candida spp., e para os testes antibacterianos foram utilizadas cepas ATCC de Enterococcus faecalis, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus mutans e Pseudomonas aeruginosa. Para a atividade antimicrobiana primeiramente foram determinados os valores da Concentração Inibitória Mínima (CIM) e da Concentração Microbicida Mínima (CMM) dos extratos pelo método de microdiluição em caldo, segundo Clinical and Laboratory Standards Institute (CLSI). Os micro-organismos que apresentaram CMM foram selecionados para os testes em biofilme, no qual foi preparado em fundo de placa com 96 poços, por 48 h. Após os biofilmes foram tratados por 5 min. utilizando as concentrações de 200, 100 e 50 mg dos extratos. Para mensuração da biomassa foi utilizado o teste de Cristal violeta (CV), e para avaliar a atividade metabólica foi utilizado o teste de MTT. A citotoxicidade foi avaliada sobre fibroblastos gengivais humanos (FMM-1) utilizando os mesmos parâmetros de tratamento utilizados para os testes em biofilmes. Foram avaliadas a viabilidade celular pelos testes de MTT, vermelho neutro e cristal violeta. Os dados obtiveram distribuição normal e foram analisados por ANOVA e teste de Tukey, com significância de 5% (p<0.05%). O extrato de P. paniculata demostrou ação antifúngica em biofilmes, com reduções médias de 29,4 e 42,7% nos testes de CV e MTT. Já a ação antibacteriana foi restrita a S. mutans e P. aeruginosa com reduções médias de 15,7 e 28,6% nos respectivos testes. O extrato de J. regia também demostrou ação antifúngica com redução média de 22,2% na biomassa e 31,4% na atividade metabólica. A ação antimicrobiana ficou restrita a P. aeruginosa com reduções médias de 17,7 e 15,6%, indicados pelos testes de CV e MTT. Quanto a citotoxicidade, a média entre os três testes realizados, indicou que após exposição ao extrato de P. paniculata 58,8% das células continuaram viáveis e para J. regia a viabilidade foi de 65,1%. Conclui-se queo extrato de P. paniculata demostrou ação antifúngica sobre todas as cepas de Candida spp. testadas e demostrou ação antibacteriana para P. aeruginosa e S. mutans. As concentrações de 200, 100 e 50 mg do extrato demostraram ser citotóxicas conforme nova diretriz de toxicidade. J. regia demostrou ação antifúngica sobre todas as cepas de Candida spp. testadas e demostrou ação antibacteriana sobre P. aeruginosa. Apenas a concentração de 200 mg do extrato se mostrou tóxica a FMM-1. / The aim of this study was to investigate whether extracts of Pfaffia paniculata K. and Juglans regia L. have antifungal, antibacterial and cellular toxicity, with in vitro tests. ATCC strains of Candida spp. Were used for antifungal tests, and ATCC strains of Enterococcus faecalis, Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus mutans and Pseudomonas aeruginosa were used for the antibacterial tests. For the antimicrobial activity, the values of the Minimum Inhibitory Concentration (MIC) and the Minimal Microbicidal Concentration (CMM) of the extracts were determined by the microdilution method in broth, according to Clinical and Laboratory Standards Institute (CLSI). The microorganisms that presented CMM were selected for the biofilm tests, in which it was prepared on a 96-well plate bottom for 48 h. After the biofilms were treated for 5 min. Using the concentrations of 200, 100 and 50 mg of the extracts. To measure the biomass, the Violet Crystal test (CV) was used, and the MTT test was used to evaluate the metabolic activity. Cytotoxicity was assessed on human gingival fibroblasts (FMM-1) using the same treatment parameters used for biofilm tests. Cell viability was evaluated by the MTT, neutral red and violet crystal tests. The data obtained normal distribution and were analyzed by ANOVA and Tukey test, with significance of 5%. The extract of P. paniculata showed antifungal action in biofilms, with average reductions of 29.4 and 42.7% in CV and MTT tests; The antibacterial action was restricted to S. mutans and P. aeruginosa with mean reductions of 15.7 and 28.6% in the respective tests. The extract of J. regia also demonstrated antifungal action with an average reduction of 22.2% in biomass and 31.4% in metabolic activity. The antimicrobial action was restricted to P. aeruginosa with mean reductions of 17.7 and 15.6%, indicated by CV and MTT tests. As for cytotoxicity, the mean of the three tests carried out indicated that after exposure to P. paniculata extract 58.8% of the cells remained viable and for viability the viability was 65.1%. In conclusion the extract of P. paniculata showed antifungal action on all strains of Candida spp. Tested and demonstrated antibacterial action for P. aeruginosa and S. mutans. The concentrations of 200, 100 and 50 mg of the extract proved to be cytotoxic according to the new toxicity guideline. J. regia demonstrated antifungal action on all strains of Candida spp. Tested and demonstrated antibacterial action on P. aeruginosa. Only the 200 mg concentration of the extract was shown to be toxic to FMM-1.
3

A Novel Trace Elemental Analysis of Potassium Phosphates

Rohman, Joshua 28 June 2016 (has links)
No description available.
4

IncorporaÃÃo de Ãleo essencial de manjericÃo em filmes biodegradÃveis à base de galactomanana e Ãleo de canola / Essential oil of basil incorporation into biodegradable films galactomannan base and canola oil

Rosueti DiÃgenes de Oliveira Filho 12 August 2015 (has links)
FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico / Embalagens biodegradÃveis sÃo coberturas utilizadas em alimentos na forma de filmes ou revestimentos, formadas por macromolÃculas tanto de origem vegetal como de origem animal, que garantem propriedades de barreira e podem servir como veÃculo para compostos antimicrobianos. Os polissacarÃdeos de reserva de parede celular, principalmente as hemiceluloses como as galactomananas, vÃm sendo extensamente usadas como matrizes polimÃricas de filmes biodegradÃveis. O objetivo deste trabalho foi avaliar a incorporaÃÃo de Ãleo essencial de manjericÃo (OEM) (Ocimum basilicum) em filmes biodegradÃveis à base de galactomanana endospÃrmica de sementes de flamboyant (Delonix regia) e Ãleo canola (OC) (Brassica napus L.). A Galactomanana (Gal) foi isolada por extraÃÃo aquosa, seguida por precipitaÃÃo em etanol. O rendimento determinado foi de 12,0%, com alto grau de pureza apresentado pelo baixo teor de nitrogÃnio expresso em proteÃna (0,67%). A Gal apresentou viscosidade intrÃnseca mÃdia de 3,79 dL/g e massa molar estimada de 1,04x106 g/mol. Os espectros de infravermelho por transformada de Fourier (FTIR) e ressonÃncia magnÃtica nuclear (RMN) de 1H e 13C foram similares aos encontrados na literatura para outras galactomananas. A composiÃÃo em Ãcidos graxos do OC por cromatografia a gÃs (GC-FID) apresentou teores de Ãcido oleico (62,07%), linoleico (18,91%) e heneicosanÃico (6,61%). Os componentes majoritÃrios do OEM determinados por cromatografia a gÃs acoplado à espectrometria de massas (GC-MS) foram cÃnfora (14,85%) e 1,8-cineol (3,48%). Os filmes foram formulados com Gal 1% (m/v), glicerol 0,5% (m/v) e OC em diferentes concentraÃÃes, 0,25, 0,5 e 0,75% (m/v). Os filmes foram obtidos pelo mÃtodo de evaporaÃÃo de solvente (casting) e caracterizados quanto ao teor de umidade, espessura, permeabilidade ao vapor de Ãgua (PVA), cor e opacidade. O OC promoveu aumento de PVA e diminuiÃÃo do teor de umidade quando comparado ao filme apenas de galactomanana, mas sem diferenÃa significativa entre as concentraÃÃes. O OEM foi testado frente Ãs cepas bacterianas de Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Salmonella choleraesuis, Staphylococcus aureus e levedura Candida albicans por microdiluiÃÃo em caldo e apresentou concentraÃÃo inibitÃria mÃnima (CIM) variando entre 2,5 e 5,0 mg/mL e concentraÃÃo bactericida mÃnima (CBM) entre 5,0 e 20,0 mg/mL. A partir do filme com formulaÃÃo de 0,5 % (m/v) de OC incorporou-se OEM em diferentes concentraÃÃes (2,5, 5,0 e 7,5 mg/mL). Os filmes antimicrobianos foram obtidos por casting e discos de 1 cm de diÃmetro foram excisados e testados por mÃtodo de difusÃo em Ãgar e a zona de contato e os halos de inibiÃÃo analisados. S. aureus, E. coli e P. aeruginosa foram sensÃveis ao filme contendo 5,0 mg/mL de OEM apresentando halos de 14, 15 e 16,3 mm, respectivamente. K. pneumoniae foi inibida apenas na zona de contato do filme, enquanto que S. choleraesuis e C. albicans foram resistentes à todas as formulaÃÃes. Contudo, O OC promoveu alteraÃÃes nas propriedades fÃsicas e de barreira dos filmes de galactomanana e OEM quando incorporado ao filme apresentou uma atividade antimicrobiana moderada para potencial aplicaÃÃo como embalagens bioativas. / Biodegradable Packaging are used in foods as films or coatings formed by plant macromolecules such as animal, ensuring barrier properties and can serve as a carrier for antimicrobial compounds. The cell wall polysaccharides reservation, especially hemicelluloses as galactomannans, have been used widely as biodegradable polymer matrices films. The objective of this study was to evaluate the Basil essential oil (BEO) (Ocimum basilicum) incorporation in biodegradable films based on endospermic galactomannan Delonix regia seeds and canola oil (CO) (Brassica napus L.). The galactomannan (Gal) was isolated by aqueous extraction, followed by ethanol precipitation. The yield was 12.0% with high purity presented by low nitrogen content expressed protein (0.67%). The Gal showed an average intrinsic viscosity of 3.79 dL/g and molecular weight estimated in 1,04x106 g/mol. Infrared spectra by Fourier transform (FTIR) and nuclear magnetic resonance (NMR) 1H and 13C were similar to those found in the literature for other galactomannans. The fatty acid composition of CO by gas chromatography (GC-FID) showed oleic acid (62.07%), linoleic (18.91%) and heneicosanÃico (6.61%) content. The major components of BEO determined by gas chromatography coupled to mass spectrometry (GC-MS) were camphor (14.85%) and 1.8-cineole (3.48%). The films were formulated with galactomannan 1% (w/v), glycerol 0.5% (w/v) and CO at different concentrations, 0.25, 0.5 and 0.75% (w/v). The films were obtained by the solvent evaporation method (casting) and characterized as the moisture content, thickness, water vapor permeability (WVP), color and opacity. The CO promoted increase of WPV and reduced moisture content when compared to the film based only in galactomannan but no significant difference between concentrations. BEO was tested against the bacterial strains of Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae, Salmonella choleraesuis, Staphylococcus aureus and Candida albicans yeast by broth microdilution and showed minimum inhibitory concentration (MIC) ranging between 2.5 and 5.0 mg/ml and minimum bactericidal concentration (MBC) between 5.0 and 20.0 mg/ml. BEO was incorporated into film formulation with CO 0.5% (w/v) in different concentrations (2.5, 5.0 and 7.5 mg/ml). The antimicrobial films were obtained by casting and disks of 1 cm in diameter were excised and tested by the agar diffusion method and a contact zone and inhibition halos analyzed. S. aureus, E. coli and P. aeruginosa were sensitive to film containing BEO 5.0 mg/ml showed halos of 14, 15 and 16.3 mm, respectively. K. pneumoniae was inhibited only in the contact zone of the film, while S. choleraesuis and C. albicans were resistant to all formulations. However, the OC promoted changes in physical and barrier properties of the films of with galactomannan. BEO when incorporated into the film showed a moderate antimicrobial activity for potential application as bioactive packaging.
5

Métodos de superação de dormência de sementes de  Flamboyant / Methods of overcoming seed dormancy flamboyant

Bolognez, Claudinei Antonio 25 May 2012 (has links)
Made available in DSpace on 2014-08-20T13:44:28Z (GMT). No. of bitstreams: 1 dissertacao_claudinei_antonio_bolognez.pdf: 182881 bytes, checksum: 028c23054f130496cda513a0975aee69 (MD5) Previous issue date: 2012-05-25 / The Flamboyant (Delonix regia (Bojer ex Hook) Raf.) is an exotic ornamental species adapted to the conditions of the Brazilian territory, belonging to subfamily Caesalpinioideae and it has seeds with hard coat that promotes seed dormancy caused by the impermeability of seed coat to water and oxygen. The aim of this study was to test different types of mechanical scarification to overcome seedcoat dormancy of seed, associated with physical and biological aspects of Flamboyant. The study was conducted in laboratory and experimental area of the Department of Biological Sciences at the Institute of Exact and Natural Sciences, Federal University of Mato Grosso, in Rondonópolis, MT, from October 2011 to April 2012, the experimental field was protected by a screen shading retaining 50% of brightness. The treatments were: control, whose seeds had not been scarified, treatments with a hole in the coat, mechanical scarification with sandpaper number 150 for wood, water heated to 90 ° C with immersion of the seeds and water heating to 90 ° C and then immersion seeds leaving to cool to room temperature. Experimental design was completely randomized (CRD) with five treatments and four repetitions, totaling twenty installments of fifteen seeds each. With the observations, there were no significant differences between the means of overcoming the five methods employed in the work. To overcome dormancy in flamboyant the recommended method is immersion in water heated to 90 ° C and subsequent soaking of the seeds. The use of techniques to overcome flamboyant seeds may cause problems when growth in height and diameter of plants in the initial phase of establishment. / O Flamboyant (Delonix regia (Bojer ex Hook) Raf.) é uma espécie ornamental exótica adaptada as condições do território brasileiro, pertencente á subfamília Caesalpinioideae e apresenta sementes com tegumento duro que favorece a dormência das sementes causada pela impermeabilidade do tegumento à água e ao oxigênio. O objetivo deste estudo foi testar diferentes modalidades de escarificação mecânica para superar a dormência tegumentar da semente, associada a aspectos físicos e biológicos de Flamboyant. O trabalho foi desenvolvido em laboratório e área experimental pertencente ao Departamento de Ciências Biológicas do Instituto de Ciências Exatas e Naturais, Universidade Federal de Mato Grosso, em Rondonópolis, MT, no período de outubro de 2011 a abril de 2012, a área experimental de campo era protegida por uma tela sombrite retendo 50% da luminosidade. Os tratamentos foram os seguintes: testemunha cujas sementes não sofreram escarificação, tratamentos com furo no tegumento, escarificação mecânica com lixa nº 150 para madeira, água aquecida a 90°C com a imersão das sementes e aquecimento da água até 90°C e posterior imersão das sementes deixando esfriar até temperatura ambiente. Delineamento utilizado foi Inteiramente Casualizado (DIC), com cinco tratamentos e quatro repetições, totalizando vinte parcelas de quinze sementes cada. Com as observações, não foram detectadas diferença significativa entre as médias nos cinco métodos de superação empregados no trabalho. Para superação da dormência em flamboyant o método recomendado é a imersão em água aquecida até 90°C e posterior imersão das sementes. O uso das técnicas de superação de sementes de flamboyant pode causar problemas ao crescimento em altura e diâmetro das plantas, na fase inicial de estabelecimento.
6

Mécanismes et modélisation de l'acclimatation au gel des arbres : application au noyer Juglans regia L. / Mechanisms and modelling of tree frost acclimatization : application to walnut Juglans regia L.

Charrier, Guillaume 14 March 2011 (has links)
Le gel est un des facteurs majeurs limitant l’aire de répartition des végétaux. Il a pour conséquence de limiter l’efficience de la circulation de sève brute par formation d’embolie dans les vaisseaux du xylème. Lorsqu’il y a formation de glace dans les tissus, les cellules vivantes peuvent également être lysées dans les organes lignifiés, et dans les bourgeons. Pour pallier cela, différents mécanismes de résistance sont développés pour limiter la formation d’embolie ou la résorber, pour augmenter transitoirement la tolérance à la formation de glace dans les tissus et pour éviter d’exposer les bourgeons et jeunes feuilles aux gels printaniers tardifs. Ces différents traits ont été caractérisés pour onze espèces communes ayant des limites altitudinales potentielles contrastées. Puis la physiologie de l’acclimatation au gel chez Juglans regia L. a été caractérisée, essentiellement à travers les relations entre humidité pondérale, contenu en sucres solubles, climat et levée de dormance. L’ensemble de ces données a permis d’élaborer un modèle prédictif de la résistance au gel en relation avec la physiologie de l’arbre qui pourrait, couplé avec d’autres modèles simulant la période estivale, permettre d’estimer la conjonction de différents stress sur le potentiel de résistance. / Frost is one of the major limiting constraints for plants causing embolism, living cell lysis and damages on buds during spring. Several processes are observed in trees in order to limit embolism or refill vessels, to increase frost resistance and to avoid freezing period for buds while bursting. Those different processes were monitored in eleven common species according to their potential alitudinal limt. And one was selected (Juglans regia L.) and physiology of acclimation was caracterised through interaction between water content, soluble carbohydrate (which are the best explaining factors for frost resistance), climate and dormancy release. According to those data, a predicting model for frost hardiness was built related to physiology of acclimation. This kind of model would be usefull related to a summer simulating model in order to estimate interaction between different stresses for frost hardiness potential.
7

Recovery of PGM's from Spent Autocatalyst Using Hydrometallurgy and Ultrasound-Assisted Solvent Extraction

Hung, Ying-Shiu 02 August 2001 (has links)
In this study, various techniques of hydrometallurgy and ultrasound-assisted solvent extraction were used to recover the platinum group metals (PGM¡¦s) from a composite sample of honeycomb-type autocatalysts. After they were removed from the converter casings, the autocatalyst substrates were first crushed and then ground by a ball mill. The recovery procedures employed are shown as follows: (1) dissolve PGM¡¦s from ground spent autocatalyst by aqua regia leaching; (2) separate PGM¡¦s from base metals in the aqua regia leachate by metal cementation using zinc powder so that PGM¡¦s can be precipitated out; (3) the PGM¡¦s precipitate was first dissolved by aqua regia, then proceed to remove nitrate and hydrochloride within. The residue was further dissolved in hydrochloride acid as a preparation step for solvent extraction; (4) the PGM¡¦s pregnant solution of hydrochloride acid was treated by solvent extraction and stripping to separate and purify each component of PGM¡¦s. Effects of ultrasound agitation on the efficiency of solvent extraction was also evaluated in this work. Results of aqua regia leaching experiments have shown that the quantity of dissolved PGM¡¦s increased as the solid-to-liquid ratio decreased. The maximum dissolved quantity of PGM¡¦s could be obtained by a 3-hr leaching time. At this stage, the PGM¡¦s recoveries are 80-90% for platinum and rhodium and greater than 99% for palladium. The result of a preliminary test has indicated that acetic acid can not effectively separate the PGM¡¦s and base metals. Thus, the method of cementation by zinc powder was employed to separate PGM¡¦s from base metals. Before cementation, the aqua regia leachate was diluted and pH-adjusted to greater than 2. In so doing, an almost complete cementation (>99%) could be obtained by the least quantity of zinc powder. In addition, the base metals occurred with the PGM¡¦s precipitate have been minimized except lead and zinc. While palladium was extracted by di-n-octyl sulfide (DOS), ultrasound assistance has rendered a complete extraction within a few minutes. At this stage, the extraction efficiency was found to be independent of the HCl concentration. It was found that platinum and rhodium were not extracted by DOS. When platinum was extracted by tri-n-octylamine (TOA) and assisted by ultrasound, rhodium will be extracted at the HCl concentration higher than 4M. Thus, TOA is not an effective chemical for selective extraction of platinum. TOA was then replaced by tributyl phosphate (TBP). Experimental results have indicated that the extraction of platinum using TBP was affected by the HCl concentration. The best result was obtained when the HCl concentration was 5M. Extraction by TBP was found to be fast. It took only 20-30 seconds to reach the equilibrium even with no ultrasound assistance. But multi-stage extractions are generally required to extract platinum completely. Rhodium was found to be not extracted by TBP. After palladium and platinum were extracted, only rhodium was remained in the reffinate. In summary, solvent extraction using DOS and TBP has made it possible to separate palladium, platinum, and rhodium effectively. In the palladium stripping solution almost no base metals was determined. However, zinc and lead were found in the platinum stripping solution and the rhodium-containing raffinate. These base metals should be removed to achieve a better purity for each precious metal. The TCLP (i.e., a leaching test for toxicity) result of the autocatalyst substrate after aqua regia leaching has found to be non-hazardous. However, several streams of wastewater and acid gas generated in the recovery process should be properly managed to avoid the secondary pollution.
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An Examination of Possible Carnivory in Silene regia, a Member of the Caryophyllaceae

Dienno, Garrett John 31 July 2017 (has links)
No description available.
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Base cations in forest soils : A pilot project to evaluate different extraction methods / Baskatjoner i skogsmark : Ett pilotprojekt för att utvärdera olika bestämningsmetoder

Olofsson, Jonas January 2016 (has links)
The acidification has been a known problem in Sweden for several decades. Sulphurous compounds, spread from the British Isles and the European continent led to a decrease in the pH-value of the rain that fell over Sweden. Since the acidification was discovered in the 1960s, active measures against the sulphurous deposition have been undertaken. The sulphurous deposition has decreased by 90 %, and the problem was for some time considered under control, until recently when a new era of the acidification may have started. Due to the increased demand of renewable energy, and Sweden’s potential to use biomass instead of fossil fuels, whole tree harvesting has been more utilized. Studies indicate that the forest soils are depleted in base cations in a faster rate when whole tree harvesting is performed compared to regular stem harvesting. Mass balance calculations and simulations indicate that an increased bio uptake of base cations due to whole tree harvesting leads to an increased biological acidification. However, although many studies agree that the impact of the whole tree harvest on the base cation supply of the soils is significant, long running Swedish experiments indicate that the difference between whole tree harvesting and regular stem harvesting diminishes over time. After a 40 year period, the difference in base cation supply between whole tree harvested soils and stem harvested soils are small. The reason for this could be different processes that reallocate base cations from different pools, which are not usually studied. The aim has been to investigate and evaluate different chemical extraction methods (Aqua Regia, HCl, EDTA, BaCl2, NH4OAc and water) capability to extract the base cations calcium, potassium, magnesium and sodium from four different Swedish forest soils and what this means for our understanding of how much base cations a soil contains. The extractions indicated that there is a statistical significant difference between the methods ability to extract base cations. Generally Aqua Regia was the most potent method, followed by HCl, EDTA, BaCl2, NH4OAc and water in decreasing order of effectiveness to extract the base cations. Linear correlations were found between EDTA, BaCl2 and NH4OAc. The internationally widely used method NH4OAc was considered to be at risk of underestimating the amount of base cations in the soil. / Försurningsproblematiken har länge varit ett känt problem i Sverige. Svavelhaltiga föroreningar som spreds från de brittiska öarna och den europeiska kontinenten ledde till att pH-värdet i regnet som föll över Sverige sjönk. Sedan upptäckten på 60-talet har aktiva åtgärder vidtagits mot utsläppen vilket har lett till en minskning av de försurande föroreningarna med 90 %. På grund av den stora utsläppsreduktionen som skett ansågs försurningsproblematiken vara under kontroll, tills nyligen då en ny etapp av för- surningen kan ha påbörjats. På grund av den ökande efterfrågan av förnyelsebar energi, i kombination med Sveriges stora skogstillgångar, har helträdsskörd av träd blivit alltmer nyttjad. Studier visar att markens baskatjonförråd utarmas i större utsträckning av helträdsskörd, då även grenar, rötter och toppar tas om hand jämfört med vanlig stamskörd då endast stammen tas med från skogen. Massbalanssimuleringar antyder att ett ökat bioupptag av baskatjoner på grund av helträdsskörd leder till en ökad biologisk försurning. Trots att många studier är överens om helträdsskördens inverkan på markens innehåll av baskatjoner visar lång- liggande försök i Sverige att skillnaderna mellan uttag av hela träd och stamved minskar med tiden. Efter en period på 40 år återstår endast små skillnader mellan avverknings- metoderna. Orsakerna till varför mätningarna och massbalansberäkningarna och simuleringarna inte stämmer överens kan vara många, t.ex. att det finns processer som kan omfördela baskatjoner från de som vanligtvis studeras. Syftet har varit att undersöka och utvärdera olika kemiska extraktionsmetoders (Aqua Regia, HCl, EDTA, BaCl2, NH4OAc och vatten) förmåga att extrahera baskatjonerna kalcium, kalium, magnesium och natrium från fyra olika skogsjordar i Sverige och vad resultaten betyder för vår uppfattning av mängden baskatjoner i marken. Extraktionerna visade att en statistiskt signifikant skillnad fanns mellan metodernas förmåga att extrahera de olika baskatjonerna. Generellt var Aqua Regia den metod som extraherade den största mängden baskatjoner, HCl, EDTA, BaCl2, NH4OAc och vatten följde i fallande ordning efter förmåga att extrahera baskatjonerna. Linjära korrelationer mellan EDTA, BaCl2 och NH4OAc upptäcktes. Den internationellt ofta använda metodiken för att extrahera baskatjoner, NH4OAc, ansågs riskera att underskatta mängden baskatjoner i marken.
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Le théâtre de Bulla Regia dans son contexte urbain / The theatre of Bulla Regia in its urban context

Ksouri, Hichem 05 May 2012 (has links)
Le théâtre de Bulla Regia est un des mieux conservés de Tunisie. Malgré l'intérêt certain qu'il représente son étude nécessite de tenir compte du contexte monumental dans lequel il est apparu celui du secteur constitué par les deux "esplanades" situées au Sud et à l'Ouest. La première partie de la thèse est consacrée à l'étude du théâtre proprement dit. Elle se fonde sur l'ensemble des relevés des structures en place, la description des vestiges et l'étude des blocs épars. Le monument a été interprété et restitué par comparaison avec d'autres théâtres romains bien connus situés de façon préférentielle en Afrique. L'étude présente les dessins de restitution de l'édifice en plan, élévation et coupe, ainsi que sa modélisation informatique. La recherche a démontré que le monument a connu deux états successifs. C'est en effet à la suite d'une extension que sa façade est venue mordre sur la rue située au Nord. La seconde partie s'attache à l'étude du contexte monumental auquel le théâtre est lié. Elle commence par un chapitre technique qui définit les caractéristiques des murs numides par rapport aux murs romains. Il était fondamental de pouvoir restituer son évolution chronologique et principalement de distinguer les caractéristiques de son organisation à l'époque numide. L'étude des monuments s'est intéressée à tous les temples situés au sud du théâtre, avec leurs relevés, l'étude de leurs blocs épars et leur restitution architecturale. Pour la première fois a été proposée, sur des bases solides, la restitution d'un temple d'époque numide (le temple B).Dans la dernière partie ont été discutées les trois hypothèses possibles relatives à la fonction véritable du complexe monumental constitué par les deux esplanades et le théâtre. Il a été démontré qu'il ne pouvait s'agir d'un sanctuaire organisé autour d'un temple principal ni d'un grand gymnase de tradition grecque. La seule hypothèse satisfaisante est celle qui consiste à considérer que le premier état du complexe (à l'époque numide) aurait correspondu à un palais. Celui-ci aurait compris une partie résidentielle (autour de l'esplanade B) et une partie sacrée à laquelle le théâtre était lié (autour de l'esplanade A). Cette recherche nous éclaire sur la fonction et l'évolution d'une partie importante de la ville et révèle l'existence d'un programme architectural particulièrement rare en Afrique (une résidence royale numide). Cette thèse est celle d'un architecte dont le mérite est d'avoir réalisé pour la première fois un relevé très précis une description et une interprétation poussée de ce complexe. Elle soulève des questions soumises à la réflexion de la communauté scientifique qui devraient encourager la réalisation de sondages et de fouilles permettant de confirmer et de consolider l'hypothèse avancée. / The theatre of Bulla Regia is one of the best preserved in Tunisia. Its study needs to take in consideration the monumental context constituted by the two "esplanades" situated to the south and the west and linked to it. The first part of this study concerns the theatre itself. It includes the surveys of the structures, a precise description of the remains, and the registration of the scattered blocs. It concerns the functioning of the monument and its architectural restitution. The monument have been interpreted and restituted by comparison with other well-known roman theatres mainly situated in Africa. The study presents restitution drawings in plan, elevation and section and a computing model. It has demonstrated the existence of two successive states. The limits and the caracteristics of the two states have been studied. The superposition of the new façade of the theatre with the north street is the consequence of an extension of the building. The second part concerns the study of the monumental context linked to the theatre. It begins by a technical chapter giving a key for the interpretation of the whole sector. It gives a clear definition and the caracteristics of the numid walls by opposition to the roman ones. This is fundamental to restitute the chronological evolution of the complex. The study examines afterwards all the temples situated to the south: it gives a whole survey of the remains, a study of the scattered blocs and an architectural restitution for each monument. A relative dating of these monuments has been exposed. It also has been proposed the restitution of a numid temple (temple B) according to the study of its remains and their iconography (representations on coins). In the last part, have been discussed three possible hypotheses concerning the probable function of the monumental complex (a great sanctuary, a great gymnasium in the Greek tradition or to consider that the first state of the complex corresponded to a palace). The complex would have included a residential part (esplanade B) and a sacred one (esplanade A) including the theatre. The results of this research overcome largely the interest of a study limited to a theatre. They in light on the function and evolution of a major part of the city and reveal the existence of a program particularly scarce in Africa (a royal residence). The study gives an accurate survey of the monuments and a deep interpretation of this complex. It does arouse important questions worth to encourage the realization of excavations allowing confirming and consolidating the proposed hypothesis. Its underlines the major interest of this sector and can favor the initiatives that would help its preservation and presentation.

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