• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 63
  • 29
  • 13
  • 4
  • 3
  • 2
  • 2
  • 1
  • 1
  • Tagged with
  • 134
  • 55
  • 27
  • 19
  • 13
  • 12
  • 11
  • 11
  • 11
  • 11
  • 10
  • 9
  • 8
  • 8
  • 8
  • 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.
31

Etude de la spéciation chimique de la collection nationale de violettes et mise en place d'un agro-raffinage de la violette de Toulouse / Study of the chemical speciation of the national violet collection and setting up of an agro-refining of the violet of Toulouse

Chervin, Justine 09 November 2018 (has links)
Le projet « Viola Tolosa » a pour objectif de valoriser une plante produite en Occitanie, la violette et plus particulièrement l’emblématique violette de Toulouse, pour des domaines essentiellement non alimentaires tels que la chimie des substances naturelles et la cosmétique. Les violettes appartiennent au genre Viola qui comprend plus de 500 espèces. Aujourd’hui, leurs usages sont principalement limités à des aspects ornementaux et culinaires. Néanmoins, l’intérêt croissant de la part des acteurs de la filière (industriels, cultivateurs et académiques) a conduit la région Occitanie à mettre en place le projet Viola Tolosa intitulé « Spéciation chimique de la collection nationale des violettes et mise en place d’un agro-raffinage de la violette de Toulouse ». Il comporte quatre aspects interdisciplinaires associant aspects fondamentaux et applicatifs. La caractérisation de la centaine de plants de la collection de violettes détenue par les serres municipales de Toulouse, identifiée à 80% par des noms de cultivars ou vernaculaires, a été réalisée par l’intermédiaire d’études génétique et chimiotaxonomique. Une première étude génétique basée sur les séquences des espaces internes transcrits a permis de classer 58% de la collection au rang d’espèce. Cette étude phylogénétique a été complétée par une étude chimiotaxonomique à l’aide des profils chimiques des fractions volatiles des fleurs et non-volatiles des parties aériennes de la collection. Une projection orthogonale de structures latentes a permis d’indexer 96% de l’ensemble des plants par un nom d’espèce. L’étude des métabolites secondaires non volatils des feuilles a été entreprise dans le but d’étudier le potentiel biologique des violettes, notamment les activités antioxydante, antifongique et inductrice des réponses immunitaires des plantes. L’étude détaillée d’un extrait hydroalcoolique de la violette de Toulouse a permis d’identifier huit composés antioxydants de la famille des flavonoïdes et des coumarines, dont trois ont été caractérisés par RMN 1D et 2D et deux de novo dérépliqués par réseau moléculaire. L’application sur l’ensemble de la collection a ensuite permis d’identifier six composés antioxydants, dont deux coumarines et quatre flavonoïdes, prépondérants chez deux espèces. Une relation espèce-activité a donc été mise en évidence. Au niveau des activités antifongiques, réalisées sur cinq souches de champignons, et de défenses végétales, par l’intermédiaire de l’étude de l’expression du gène marqueur « pathogenesis-related protein 1 », les résultats sont plus ambigus. Cependant, certaines espèces ont présenté une activité plus prononcée que les autres et ce criblage a permis de poser une hypothèse forte quant à l’implication des cyclotides. Finalement, l’ensemble de ces travaux a permis d’obtenir une carte d’identité des violettes de la collection (identification génétique, profil chimique, potentiel biologique) et une description semi-quantitative de l’ensemble des groupes chimiques est proposée par combinaison des données chromatographiques du détecteur Corona (CAD) et des données spectrales. Différentes méthodes d’extraction (électroporation, micro-ondes, CO2 supercritique et extraction hydroalcoolique) répondant aux préceptes de la chimie verte ont ensuite été comparées afin de sélectionner celle présentant le meilleur compromis entre le cahier des charges cosmétiques et l’enrichissement en molécules d’intérêt, en vue d’un transfert technologique. / The "Viola Tolosa" project aims to promote a plant produced in Occitanie region, the violet and especially the emblematic violet of Toulouse, essentially for non-food fields such as the chemistry of natural compounds and cosmetics. Violets belong to Viola genus including more than 500 species. Today, their uses are mainly limited to ornamental and culinary aspects. Nevertheless, the growing interest of the actors of the sector (industrials, growers and academicals) led the Occitanie region to implement the Viola Tolosa project entitled "Chemical speciation of the national collection of violets et establishment of an agro-refining of the violet of Toulouse ". It comprises four interdisciplinary aspects associating fundamental and applicative aspects. The characterization of the 100 or so plants in the violet collection owned by the Toulouse municipal greenhouses, including 80% identified by cultivar or vernacular names, was carried out through genetic and chemotaxonomic studies. A first genetic study based on internal transcribed spacers conducted to classify 58% of the collection as a species. This phylogenetic study was completed by chemotaxonomic studies of chemical profiles of flowers volatile fractions and non-volatile aerial parts of the collection. Discriminant analysis of orthogonal projection to latent structure model finally allowed indexation of 96% of all plants with a species name. Study of non-volatile secondary metabolites of leaves has also been undertaken to study the biological potential of violets, including antioxidant, antifungal and defense inducer. The detailed study of a hydroalcoholic extract of the violet of Toulouse allowed the identification of eight antioxidant compounds belonging to flavonoids and coumarins. Three of them have been characterized by 1D and 2D NMR and two were de novo dereplicated through molecular network. The application to the whole collection conducted to highlight six antioxidant compounds, including two coumarins and four flavonoids, predominant in two species. A species-activity relationship was therefore highlighted. Regarding antifungal activities carried out on five fungal strains, and defense inducer through the study of pathogenesis-related protein 1, the results are more ambiguous. However, some species showed better activity than others and this screening led to a strong hypothesis regarding the involvement of cyclotides. Finally, all this work led to the establishment of an identity card of violets of the collection (genetic identification, chemical profiling, et biological potential) et a semi-quantitative description of all the species is considered by combining chromatographic data based on corona detector et spectral data. Different methods of extraction (electroporation, microwaves, supercritical CO2 et hydroalcoholic extraction) corresponding to green chemistry precepts were then compared in order to select the one presenting the best compromise between cosmetic specifications et enrichment in molecules of interest, for technological transfer.
32

Síntese de zeólitas a partir de cinzas de carvão e aplicação como adsorventes

Zen, Barbara Potrich January 2016 (has links)
Cinzas oriundas da combustão de carvão são resíduos produzidos no processo de geração de energia em termoelétricas. Esses resíduos industriais podem ser aproveitados como matéria prima para síntese de zeólitas, as quais são materiais aluminossilicatos porosos com importantes aplicações, como adsorventes no tratamento de efluentes líquidos. Nesse contexto, o objetivo deste trabalho foi sintetizar zeólitas a partir de três diferentes cinzas de carvão e utilizá-las na remoção de corante violeta cristal em soluções aquosas via processo de adsorção. Para isso, foram sintetizadas zeólitas denominadas ZP, ZF e ZFD a partir de três diferentes cinzas de carvão, sendo elas, respectivamente: cinzas de carvão de combustão em leito pulverizado, de combustão em planta piloto de leito fluidizado e de combustão em planta piloto de leito fluidizado utilizando processo de dessulfuração interna. A síntese foi feita pelo método hidrotérmico, utilizando NaOH 3 mol L-1 como agente mineralizante, relação líquido/sólido (L/S) igual a 6 e tempo de reação de 24 h a 100 °C. Os materiais obtidos foram submetidos à caracterização física, química e morfológica, nas quais foi observada a formação de três diferentes fases zeolíticas (zeólitas P, X e sodalita) nas amostras ZF e ZFD, e uma única fase (zeólita P) na amostra ZP. Os valores de área superficial BET encontrados foram de 17, 35 e 40 m2 g-1 para as zeólitas ZP, ZFD e ZF, respectivamente, com tamanho de poros na faixa de 3 a 4 nm para os três materiais. Os valores de capacidade de troca catiônica (CTC) ficaram entre 2,07 e 2,85 meq NH4 + g-1. Posteriormente foram realizados ensaios de adsorção do corante em que foi avaliada a influência do pH, tempo de contato e concentração de sólido adsorvente. Ainda, foram construídas isotermas de adsorção para esses sistemas e os modelos de isotermas de Langmuir, Freundlich e BET modificado foram ajustados aos dados experimentais. Os resultados mostraram que a maior eficiência foi obtida pela zeólita ZF, alcançando máxima remoção de corante de 85 % nos estudos do efeito do tempo de contato, e as melhores condições experimentais obtidas foram de 60 min e 15 g L-1 de concentração de sólido adsorvente. O modelo de isotermas que melhor se ajustou aos dados experimentais foi BET modificado, com R2 = 0,9894. A síntese de zeólita a partir de cinzas de carvão mostrou potencial na produção de um adsorvente alternativo para remoção do corante violeta cristal de águas contaminadas, contribuindo também para a diminuição do impacto ambiental das atividades de combustão de carvão. / Ashes from coal combustion are waste produced in the process of power generation in thermoelectric. These industrial wastes can be used as raw material for zeolite synthesis, which are porous aluminosilicate with important applications, such as adsorbents in the treatment of liquid effluents. The objective of this study was to synthesize zeolites from three different coal ash and apply it in crystal violet dye adsorption processes in aqueous solution. Thereunto, zeolites called ZP, ZF e ZFD were synthesized from the three different coal ashes, as so, respectively: coal ashes from powdered bed combustion, from combustion in a fluidized bed pilot plant and from combustion in a fluidized bed pilot plant with internal desulphurization. The synthesis was carried by hydrothermal method, using NaOH 3 mol L-1 as the mineralizing agent, the liquid/solid ratio (L/S) equal to 6 and 24 hours reaction time at 100 ° C. The materials were subjected to physical, chemical and morphological characterization and it was observed the formation of three different zeolite phases (zeolites P, X and sodalite) in the sample ZF and ZFD, and a single phase (zeolite P) in ZP sample. The BET surface area values were 17, 35 and 40 m2 g-1 to ZP, ZFD and ZF zeolites, respectively, with pore size in the range of 3 to 4 nm for all three materials. The values of cation exchange capacity (CEC) were between 2.07 and 2.85 meq NH4 + g-1. Subsequently, adsorption tests were carried out in which it was evaluated the influence of pH, contact time and adsorbent solid concentration. Still, adsorption isotherms were built for these systems and isotherm models of Langmuir, Freundlich and modified BET were fitted to experimental data. The results showed that the highest efficiency was obtained by zeolite ZF, achieving maximum dye removal of 85 % in the studies of contact time effects, and the best experimental conditions were 60 min and adsorbent solid concentration of 15 g L-1. The BET isotherm model was found to be the best fit to experimental data, with R2 = 0.9894. The zeolite synthesis from coal ash has shown potential in the production of an alternative adsorbent to remove the crystal violet dye from contaminated water, also contributing to reducing the environmental impact of coal combustion activities.
33

Comparison of The Solid Phase Extraction and The Liquid-Liquid Extraction Methods for Triarylmethanes and Corresponding Metabolites in Aquatic Animal Tissues

Hsiang, Huang-Sung 01 September 2010 (has links)
This research investigate the matrix effect, operation time, cost and solvent comsumption for triarylmethanes and corresponding metabolites in different aquaculture products by different extraction methods. Triarylmethane was determined by LC-ESI-MS/MS in positive mode. The analytical method validation were followed the regulation of 2002/657/EC. HPLC separation was conducted with the RP-18 column. The mobile phases consisted of 0.5 mM ammonium acetate buffer (pH 3.8, adjusted with acetic acid) ¡V acetonitrile (contained 0.1% formic acid) solution. The ratios of standard deviation to average residual time for all compounds are less than 0.05. The ion ratio is stable and allowed by the regulation of 2002/657/EC. The regression constant of calibration curve is in the range from 0.998 to 0.999. The CC£\ for MG, LMG, CV, LCV are 0.09 ¡Ó 0.05, 0.19 ¡Ó 0.14, 0.15 ¡Ó 0.13, 0.15 ¡Ó 0.10 £ggkg-1, respectively. The CC£] for MG, LMG, CV, LCV are 0.09 ¡Ó 0.05, 0.19 ¡Ó 0.14, 0.15 ¡Ó 0.13, 0.15 ¡Ó0.10 £ggkg-1, respectively. The results for SPE and liquid-liquid extraction are not significantly different; the liquid-liquid extraction have shorter operation time, cheaper cost and less solvent consumption in comparison with SPE.
34

Study of SERS effect by controlling the arrangement of colloids

Lin, Zhe-Hong 15 August 2011 (has links)
In this research, two major experiments, including the self-assembly of silica spheres, were performed by using a physical confinement method with an attractive capillary force. The silica spheres were dragged and aggregated as results of the evaporation of the solvent. In the first experiment, silica spheres were assembled into the two-dimensional pattered substrate, constructed by the photo-resist film formed under a lithography process. Several patterned substrates could work as a physical trap during the flow of the silica spheres. The ordered arrangement of the silica spheres was controlled by the concentration and the size of the silica spheres, the thickness of the photo-resist film, and the titled angle of the substrate. In our conditions, the silica spheres could orderly arrange in larger area of the substrate. In the second experiment, a surface-enhanced Raman scattering (SERS) enhancement was observed from a chain of silica spheres with silver nanoparticles, which worked as a excitation source to provid a strong local electromagnetic fields exciting the crystal violet (CV) dye coated on the silica spheres. We found that the CV molecules has a strong SERS intensity due to the refraction and reflection of the incident light within the silica spheres. When the silica spheres were linearly arranged, longer length of the chained silica spheres would lead to a maximum value of the SERS intensity.
35

Roses of Love, Violets of Humility and Lilies of Suffering: A Phenomenological Hermeneutic Study of Floral Experiences in the Diary of St. Faustina Kowalska (1905-1938)

Kandler, Renate 16 September 2013 (has links)
The presence of flowers is felt in Catholic architecture, literature, artwork, personal histories and devotional practices. This, however, has not always been the case. The Catholic Church has had a long and tumultuous relationship with flowers, the focus of which has been the subject of considerable scholarship (e.g. Fisher (2011, 2007), Ward (1999), Winston-Allen (1997), Goody (1993), Coats (1970)). What has not been much considered is a phenomenological treatment of Catholic floral experience, and how such experiences have shaped individual and shared understandings of the Catholic faith. This thesis seeks to redress this omission through an exploration of the life of the Polish Catholic mystic, St. Faustina Kowalska (1905-1938), whose mystical experiences with the divine were explicitly mediated and narrated through flowers. Through Faustina’s diary, Divine Mercy in my Soul, we gain access to powerful, and unequivocally Catholic, experiences with flowers which comprise the very centre of her religious convictions. This thesis queries the ways in which flowers have dynamically shaped, and have been shaped by, St. Faustina's relationship with God and Catholic holy figures. To address this question I use the semiotic, phenomenological and hermeneutic approach of Max van Manen. Van Manen uses four elements of lived experience he calls lifeworld existentials, these are: lived space, lived time, lived body and lived relationality. These four categories are applied to St. Faustina’s life as she engages with God spatially, temporally, corporeally and relationally; each reveals the centrality of flowers in her religious experiences. While this thesis focuses on the religio-floral experiences of a particular mystic-saint, its significance lies also in the broader Catholic narrative of which it is a part. Writing about flowers was a transformative medium in Faustina's life and has been historically significant in the lives of many other Catholic saints and mystics who recorded similar experiences. This thesis, in describing the details of St. Faustina’s floral-saturated experiences from her diary, reveals a particularized instance of a paradigmatic Catholic phenomenon whereby flowers provide access to the sacred.
36

The effect on bacterial biofilms of endoscopic sinus surgery and long term low-dose macrolide antibiotics for chronic rhinosinusitis

Vu Thanh Hai Phan Unknown Date (has links)
Abstract: The role of bacterial biofilms in patients with persistent CRS is of growing concern. The limited efficacy of some medical and surgical treatments for CRS illustrates the need for further progress in this area. The current treatments of chronic rhinosinusitis are concentrated on medical +/- surgical therapy. In this thesis, we consider two methods performed in chronic rhinosinusitis, endoscopic sinus surgery and long term low-dose macrolide therapy, and consider how they can affect bacterial biofilms. The effect of endoscopic sinus surgery on bacterial biofilms and the clinical impact of this condition on CRS patients may be far more profound than we can currently understand. To understand the impact of ESS on bacterial biofilms, we have performed the first prospective study to evaluate the effect of ESS on bacterial biofilms in patients with CRS and patients’ clinical outcomes after 3 months follow-up. We have shown that ESS results in a statistically significant improvement in QoL, subjective and objective outcome measures. In terms of bacterial biofilms, the mean OD630nm of isolates was significantly reduced after 3 months follow-up (p=0.043). No correlations between the reduction of bacterial biofilms with any of the objective, subjective and QoL outcomes were seen in our study. Macrolides have demonstrated their anti-inflamatory effects in the treatment of diffuse panbronchiolitis, asthma, cystis fibrosis and chronic rhinosinusitis. In recent years, there are a number of in vitro studies supporting the anti-biofilm effects of macrolide antibiotics, especially at sub-MICs level. These have shown that macrolides alter the outer membrane, lipopolysaccharide of biomass and inhibit the expression of other bacterial virulence factors which may disrupt the adherence of bacteria to form biofilms. Long term low dose macrolide therapy, therefore, may transform bacterial biofilms from the protected organized form into the plantonic form. In this thesis, we also report the first in vivo efficacy of long term low dose macrolides on bacterial biofilms in patients with CRS. Patients receiving oral macrolide showed significant improvements in subjective, objective and QoL scores following a 12 week course. Nasal swabs were taken from CRS patients at the first visit and 3 months after macrolide therapy. Using the microtiter biofilm assay, these swabs showed a reduction in the mean OD630nm of isolates in 8/12 patients. While it is well-known that bacterial biofilms are established in CRS patients, the relationship between the improvement of clinical symptoms and the severity of bacterial biofilm is less clear.
37

"Come look at the freaks" the complexities of valorizing the "freak" in "Side show" /

Harrick, Stephen. January 2007 (has links)
Thesis (M.A.)--Bowling Green State University, 2007. / Document formatted into pages; contains viii, 71 p. Includes bibliographical references.
38

Síntese de zeólitas a partir de cinzas de carvão e aplicação como adsorventes

Zen, Barbara Potrich January 2016 (has links)
Cinzas oriundas da combustão de carvão são resíduos produzidos no processo de geração de energia em termoelétricas. Esses resíduos industriais podem ser aproveitados como matéria prima para síntese de zeólitas, as quais são materiais aluminossilicatos porosos com importantes aplicações, como adsorventes no tratamento de efluentes líquidos. Nesse contexto, o objetivo deste trabalho foi sintetizar zeólitas a partir de três diferentes cinzas de carvão e utilizá-las na remoção de corante violeta cristal em soluções aquosas via processo de adsorção. Para isso, foram sintetizadas zeólitas denominadas ZP, ZF e ZFD a partir de três diferentes cinzas de carvão, sendo elas, respectivamente: cinzas de carvão de combustão em leito pulverizado, de combustão em planta piloto de leito fluidizado e de combustão em planta piloto de leito fluidizado utilizando processo de dessulfuração interna. A síntese foi feita pelo método hidrotérmico, utilizando NaOH 3 mol L-1 como agente mineralizante, relação líquido/sólido (L/S) igual a 6 e tempo de reação de 24 h a 100 °C. Os materiais obtidos foram submetidos à caracterização física, química e morfológica, nas quais foi observada a formação de três diferentes fases zeolíticas (zeólitas P, X e sodalita) nas amostras ZF e ZFD, e uma única fase (zeólita P) na amostra ZP. Os valores de área superficial BET encontrados foram de 17, 35 e 40 m2 g-1 para as zeólitas ZP, ZFD e ZF, respectivamente, com tamanho de poros na faixa de 3 a 4 nm para os três materiais. Os valores de capacidade de troca catiônica (CTC) ficaram entre 2,07 e 2,85 meq NH4 + g-1. Posteriormente foram realizados ensaios de adsorção do corante em que foi avaliada a influência do pH, tempo de contato e concentração de sólido adsorvente. Ainda, foram construídas isotermas de adsorção para esses sistemas e os modelos de isotermas de Langmuir, Freundlich e BET modificado foram ajustados aos dados experimentais. Os resultados mostraram que a maior eficiência foi obtida pela zeólita ZF, alcançando máxima remoção de corante de 85 % nos estudos do efeito do tempo de contato, e as melhores condições experimentais obtidas foram de 60 min e 15 g L-1 de concentração de sólido adsorvente. O modelo de isotermas que melhor se ajustou aos dados experimentais foi BET modificado, com R2 = 0,9894. A síntese de zeólita a partir de cinzas de carvão mostrou potencial na produção de um adsorvente alternativo para remoção do corante violeta cristal de águas contaminadas, contribuindo também para a diminuição do impacto ambiental das atividades de combustão de carvão. / Ashes from coal combustion are waste produced in the process of power generation in thermoelectric. These industrial wastes can be used as raw material for zeolite synthesis, which are porous aluminosilicate with important applications, such as adsorbents in the treatment of liquid effluents. The objective of this study was to synthesize zeolites from three different coal ash and apply it in crystal violet dye adsorption processes in aqueous solution. Thereunto, zeolites called ZP, ZF e ZFD were synthesized from the three different coal ashes, as so, respectively: coal ashes from powdered bed combustion, from combustion in a fluidized bed pilot plant and from combustion in a fluidized bed pilot plant with internal desulphurization. The synthesis was carried by hydrothermal method, using NaOH 3 mol L-1 as the mineralizing agent, the liquid/solid ratio (L/S) equal to 6 and 24 hours reaction time at 100 ° C. The materials were subjected to physical, chemical and morphological characterization and it was observed the formation of three different zeolite phases (zeolites P, X and sodalite) in the sample ZF and ZFD, and a single phase (zeolite P) in ZP sample. The BET surface area values were 17, 35 and 40 m2 g-1 to ZP, ZFD and ZF zeolites, respectively, with pore size in the range of 3 to 4 nm for all three materials. The values of cation exchange capacity (CEC) were between 2.07 and 2.85 meq NH4 + g-1. Subsequently, adsorption tests were carried out in which it was evaluated the influence of pH, contact time and adsorbent solid concentration. Still, adsorption isotherms were built for these systems and isotherm models of Langmuir, Freundlich and modified BET were fitted to experimental data. The results showed that the highest efficiency was obtained by zeolite ZF, achieving maximum dye removal of 85 % in the studies of contact time effects, and the best experimental conditions were 60 min and adsorbent solid concentration of 15 g L-1. The BET isotherm model was found to be the best fit to experimental data, with R2 = 0.9894. The zeolite synthesis from coal ash has shown potential in the production of an alternative adsorbent to remove the crystal violet dye from contaminated water, also contributing to reducing the environmental impact of coal combustion activities.
39

Bioecologia e controle microbiano de sarsina violascens (Herrich-schaeffer, 1856) (Lepidoptera: Lymantriidae) em Eucalyptus spp

Winckler, Daniela Cristina Firmino [UNESP] 03 July 2010 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:34:59Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-07-03Bitstream added on 2014-06-13T18:45:52Z : No. of bitstreams: 1 winckler_dcf_dr_botfca.pdf: 826861 bytes, checksum: 0065d6bc13ca46069b7bee48b655a961 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / A espécie Sarsina violascens (Herrich–Schaeffer, 1856) (Lepidoptera: Lymantriidae) é relatada como praga primária em plantios de eucalipto e teve sua primeira ocorrência registrada em 1975. No período de 2006 a 2009 houve grandes surtos dessa praga, causando desfolhamento intenso em plantios de eucalipto no norte da Bahia. Apesar dos estudos feitos no passado terem considerado espécies de eucalipto, há pouca informação sobre a suscetibilidade de clones híbridos de eucalipto à mariposa violácea. O presente trabalho teve por objetivo avaliar a biologia de S. violascens em diferentes espécies e híbridos de eucalipto e em diferentes temperaturas, além de avaliar a eficiência de entomopatógenos no controle de S. violascens. No experimento 1 a biologia de S. violascens foi determinada nas espécies Eucalyptus grandis, E. urophylla e dois híbridos de E. grandis x E. urophylla (‘urograndis’). Os parâmetros avaliados foram duração e viabilidade dos estágios larval, pupal, adulto e de ovo e do ciclo total. No experimento 2 foi selecionada a espécie E. urophylla como padrão e avaliou-se o efeito de diferentes temperaturas (18, 22, 26 e 30oC) no desenvolvimento de S. violascens, avaliando-se os mesmos parâmetros anteriores. Os resultados obtidos no experimento 1 revelaram que E. urophylla ofereceu melhores condições para odesenvolvimento de S. violascens, com maior viabilidade larval (85,3 %), pupal (78,7 %) e de ovos (72,6 %), e menor duração do ciclo total (54,4 dias). A espécie E. grandis foi considerada a menos adequada ao desenvolvimento de S. violascens, revelando baixas viabilidades larval (29,2 %) e pupal (28,9 %). Os resultados obtidos com os dois híbridos foram intermediários comparativamente com as espécies testadas. No experimento 2 as temperaturas de 18, 22 e 26°C foram adequadas para o desenvolvimento e reprodução de S. violascens, com alta viabilidade... / Defoliator lepidopterous are one of the main Eucalyptus pest groups in Brazil. There are records of caterpillars outbreaks since 1940, with important occurrences during 1980’s to 1990’s. The species Sarsina violascens (Herrich–Schaeffer, 1856) (Lepidoptera: Lymantriidae), named as violet moth, is related as pest in eucalypts plantations since 1975 and during 2006 to 2009, this species has occurred in outbreaks, causing intense defoliation in eucalypt plantations in Northern Bahia, Brazil. Despite studies in the past have considered species of eucalyptus, there is little information about susceptibility of Eucalyptus hybrid clones to violet moth. This study aimed to determine the biology of S. violascens in different species and hybrids of eucalyptus and in different temperatures. The insects were observed diary to evaluate life cycle in different species of eucalyptus (experiment 1) and in different temperatures (experiment 2). In experiment 1 were tested the following species: Eucalyptus grandis, E. urophylla and two hybrids of E. grandis x E. urophylla (‘urograndis’). The parameters evaluated were: duration and viability of larvae, pupae, adult and eggs phases and total life cycle. In experiment 2 was chose the species E. urophylla as standard and evaluated the effect of temperatures of 18, 22, 26 and 30oC, considering the same previous parameters. The results obtained in experiment 1 showed that E. urophylla offered better conditions to S. violascens development and reproduction, due the higher larvae, pupae and eggs viability, and shorter total life cycle duration. The species E. grandis was considered as less adequate to S. violascens development and reproduction, with low larvae and pupae viability. To the two hybrid clones, the results were intermediary comparatively with tested species. In experiment 2 temperature of 18°C showed the most adequate to S. violascens... (Complete abstract click electronic access below)
40

Síntese de zeólitas a partir de cinzas de carvão e aplicação como adsorventes

Zen, Barbara Potrich January 2016 (has links)
Cinzas oriundas da combustão de carvão são resíduos produzidos no processo de geração de energia em termoelétricas. Esses resíduos industriais podem ser aproveitados como matéria prima para síntese de zeólitas, as quais são materiais aluminossilicatos porosos com importantes aplicações, como adsorventes no tratamento de efluentes líquidos. Nesse contexto, o objetivo deste trabalho foi sintetizar zeólitas a partir de três diferentes cinzas de carvão e utilizá-las na remoção de corante violeta cristal em soluções aquosas via processo de adsorção. Para isso, foram sintetizadas zeólitas denominadas ZP, ZF e ZFD a partir de três diferentes cinzas de carvão, sendo elas, respectivamente: cinzas de carvão de combustão em leito pulverizado, de combustão em planta piloto de leito fluidizado e de combustão em planta piloto de leito fluidizado utilizando processo de dessulfuração interna. A síntese foi feita pelo método hidrotérmico, utilizando NaOH 3 mol L-1 como agente mineralizante, relação líquido/sólido (L/S) igual a 6 e tempo de reação de 24 h a 100 °C. Os materiais obtidos foram submetidos à caracterização física, química e morfológica, nas quais foi observada a formação de três diferentes fases zeolíticas (zeólitas P, X e sodalita) nas amostras ZF e ZFD, e uma única fase (zeólita P) na amostra ZP. Os valores de área superficial BET encontrados foram de 17, 35 e 40 m2 g-1 para as zeólitas ZP, ZFD e ZF, respectivamente, com tamanho de poros na faixa de 3 a 4 nm para os três materiais. Os valores de capacidade de troca catiônica (CTC) ficaram entre 2,07 e 2,85 meq NH4 + g-1. Posteriormente foram realizados ensaios de adsorção do corante em que foi avaliada a influência do pH, tempo de contato e concentração de sólido adsorvente. Ainda, foram construídas isotermas de adsorção para esses sistemas e os modelos de isotermas de Langmuir, Freundlich e BET modificado foram ajustados aos dados experimentais. Os resultados mostraram que a maior eficiência foi obtida pela zeólita ZF, alcançando máxima remoção de corante de 85 % nos estudos do efeito do tempo de contato, e as melhores condições experimentais obtidas foram de 60 min e 15 g L-1 de concentração de sólido adsorvente. O modelo de isotermas que melhor se ajustou aos dados experimentais foi BET modificado, com R2 = 0,9894. A síntese de zeólita a partir de cinzas de carvão mostrou potencial na produção de um adsorvente alternativo para remoção do corante violeta cristal de águas contaminadas, contribuindo também para a diminuição do impacto ambiental das atividades de combustão de carvão. / Ashes from coal combustion are waste produced in the process of power generation in thermoelectric. These industrial wastes can be used as raw material for zeolite synthesis, which are porous aluminosilicate with important applications, such as adsorbents in the treatment of liquid effluents. The objective of this study was to synthesize zeolites from three different coal ash and apply it in crystal violet dye adsorption processes in aqueous solution. Thereunto, zeolites called ZP, ZF e ZFD were synthesized from the three different coal ashes, as so, respectively: coal ashes from powdered bed combustion, from combustion in a fluidized bed pilot plant and from combustion in a fluidized bed pilot plant with internal desulphurization. The synthesis was carried by hydrothermal method, using NaOH 3 mol L-1 as the mineralizing agent, the liquid/solid ratio (L/S) equal to 6 and 24 hours reaction time at 100 ° C. The materials were subjected to physical, chemical and morphological characterization and it was observed the formation of three different zeolite phases (zeolites P, X and sodalite) in the sample ZF and ZFD, and a single phase (zeolite P) in ZP sample. The BET surface area values were 17, 35 and 40 m2 g-1 to ZP, ZFD and ZF zeolites, respectively, with pore size in the range of 3 to 4 nm for all three materials. The values of cation exchange capacity (CEC) were between 2.07 and 2.85 meq NH4 + g-1. Subsequently, adsorption tests were carried out in which it was evaluated the influence of pH, contact time and adsorbent solid concentration. Still, adsorption isotherms were built for these systems and isotherm models of Langmuir, Freundlich and modified BET were fitted to experimental data. The results showed that the highest efficiency was obtained by zeolite ZF, achieving maximum dye removal of 85 % in the studies of contact time effects, and the best experimental conditions were 60 min and adsorbent solid concentration of 15 g L-1. The BET isotherm model was found to be the best fit to experimental data, with R2 = 0.9894. The zeolite synthesis from coal ash has shown potential in the production of an alternative adsorbent to remove the crystal violet dye from contaminated water, also contributing to reducing the environmental impact of coal combustion activities.

Page generated in 0.0662 seconds