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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

The United States and the international struggle for rubber, 1914-1941

Chalk, Frank Robert, January 1900 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1970. Vita. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.
2

Quantificação do amido na madeira de seringueira [Hevea brasiliensis (Willd. ex Adr. de Juss.) Muell-Arg.] /

Cherelli, Sabrina Galetti, 1986- January 2018 (has links)
Orientador: Adriano Wagner Ballarin / Coorientador: Magali Leonel / Banca: Hernando Alfonso Lara Palma / Banca: José Nivaldo Garcia / Banca: Thais Paes Rodrigues dos Santos / Banca: Ana Paula Cerino Coutinho / Resumo: O amido é o principal carboidrato de reserva das plantas, composto por dois tipos de α-glucanas, amilose e amilopectina, e tem um importante papel no metabolismo das árvores, incluindo sua importância para estudos de resposta das plantas à diferentes situações durante seu ciclo fenológico e como uma ferramenta complementar para predição do desempenho de sistemas de sangria nas seringueiras, assim como a associação de seu acúmulo com o crescimento e com a rebrota. Este constituinte é encontrado em grande quantidade na madeira de H. brasiliensis. Contudo, a quantificação de amido em madeira ainda é considerada problemática por diversas razões que vão desde a escolha até a implementação de um método adequado, apesar da grande quantidade de estudos encontrados na literatura. Considerando a importância deste carboidrato nas plantas e a problemática envolvida na escolha de um método de quantificação adequado para madeira, quantificou-se o teor de amido em amostras provenientes da direção radial (sentido medula ‒ casca) em discos de H. brasiliensis por dois protocolos diferentes, buscando, entre as técnicas convencionais de hidrólise (ácida e enzimática), qual é a mais apropriada para esta espécie e sugerir um protocolo de quantificação de amido viável à empresas produtoras de seringueira, caso queiram utilizar a quantificação de amido num processo de controle de qualidade da espécie, e à laboratórios de pesquisa com madeiras. Também analisou-se a distribuição radial de amido em amo... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Starch is the principal carbohydrate reserve in plants, represented by two types of α-glucans, amylose and amylopectin and has a significant role in tree metabolism including its importance for studies of plant response to different situations during its phenological cycle and as a complementary tool to predict the performance of tapping systems in rubberwood, as well as the association of its accumulation to rebudding and growth. This constituent is found in great content in the wood of H. brasiliensis. However, the starch analysis is still problematic despite of the large amount of studies found in the literature. Considering these key factors, the starch content was quantified in samples from the radial direction (pith - bark) of H. brasiliensis disks by two different protocols, seeking, among the existing conventional hydrolysis techniques (acid and enzymatic), which is the most appropriate for that species and to suggest a protocol for starch quantification that can be viable to the rubberwood producing companies in a quality control process of the species and to research laboratories that works with wood characterization. It was also analyzed the radial distribution of starch content of H. brasiliensis samples collected in two different seasons of the year and two different growth site and additionally, it was estimated the sapwood longevity of this species by microscopic analyzes. For the methodological study, we analyzed five radial samples from disks of fifteen trees by two different protocols. The protocol 1 used acid to hydrolyze the starch and anthone method for glucose assay and protocol 2 used enzymes to hydrolyze the starch and peroxidase-glucose oxidade (PGO) and o-dianisidine for glucose assay. To analyze the radial distribution of starch content in different seasons and different growth sites it was used the protocol 2 (enzymatic hydrolysis) in five radial samples from disks ... / Doutor
3

Water and stress effects on growth and rubber accumulation in guayule (Parthenium argentatum gray) /

Garrot, Donald Jerome. January 1984 (has links) (PDF)
Thesis (Ph. D. - Plant Sciences)--University of Arizona, 1984. / Includes bibliographical references (leaves 75-77).
4

Estudo dos componentes não isoprênicos do látex de Hevea brasiliensis indutores de angiogênese

Agostini, Deuber Lincon da Silva [UNESP] 05 July 2013 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:32:51Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-07-05Bitstream added on 2014-06-13T18:44:19Z : No. of bitstreams: 1 agostini_dls_dr_bauru.pdf: 1803645 bytes, checksum: 1ba74c4c9393d0cd53d03478b6fe2f01 (MD5) / Atualmente é comprovado o poder de indução de angiogênese e neoformação tecidual através de membranas de borracha natural de Hevea brasiliensis. Este trabalho apresenta um estudo sobre as propriedades e a caracterização das frações não isoprênicas, separadas por centrifugação do látex, utilizado como biomaterial na indução de angiogênese e de neoformação. As frações constituintes, F2 e F3 sem o tradicional agente estabilizante de hidroxido de amônio (NH4OH), foram liofilizadas para a redução da quantidade de água e estabilização, em seguida tratadas termicamente a temperatura de 40,60,80, 100, 120 e 140ºC e novamente liofilizadas, sendo caracterizada através das técnicas de Kjeldahl, Soxhlet, de espectroscopia de absorção no infravermelho (FT-IR), Ressonância Magnética Nuclear (RMn-13C). Difração de raios x (DRX), termogravimetria (TG) acoplado ao FT-IR (IG/FT-IR), calorimetria exploratória diferencial (DSC), eletroforese, dosagens de citocinas e síntese de óxido nítrico considerando o fator limitate do uso do látex como um material bioativo, que é a temperatura de tratamento térmico, realizado para a obtenção das membranas de borracha natural, em torno de 85ºC. Foi possível verificar que a fração F3 constituinte do látex, tem propriedades anti-inflamatórias e que a fração F2 possui propriedades pró-inflamatórias / Currently it is proven the hability of inducing angiogenesis and tissue neoformating through membranes of natural rubber Hevea brasiliensis, so this work presents a study on the properties and characterization of non-isoprene fractions, separated by centrifugation, the latex used as biomaterial for induction and neoformation of angiongenesis and lyophilized without the traditional stabilizing agent, ammonium hydroxide (NH4OH). The fractions constituents, F2 and F3 fractions were lyophilized without the traditional stabilizing agent, ammonium hydroxide (NH4OH). The fractions constituents, F2 and F3 fractions were lyophilized to reduce the amount of water and stabilization, and then heat treated at temperature of 40, 60, 80, 100, 120 and 140ºC bieng characterized by the techniques of kjeldahl, Soxhlet, of absorption spectroscopy infrared (FT-IR), Nuclear Magnetic Resonance (NMR-13C), X-ray Diffraction (XRD), thermogravimetry (TG) coupled to FT-IR (TG-IR), differential scanning calorimetry (DSC), electrosphoresis, serum cytokines and oxide nitric (NO) considering the limiting factor in the use of latex as a bioactive material, which is the thermal treatment temperature, held for obtaining membranes of natural rubber, about 85ºC. It was possible to verify that the fraction F3 constituent latex has anti-inflammatory and the fraction F2 take inflammatory properties
5

Estudo dos componentes não isoprênicos do látex de Hevea brasiliensis indutores de angiogênese /

Agostini, Deuber Lincon da Silva. January 2013 (has links)
Orientador: Aldo Eloizo Job / Banca: Mariselma Ferreira / Banca: Ivan Helmuth Bechtold / Banca: José Antonio Malmonge / Banca: Eduardo René Perez / Resumo: Atualmente é comprovado o poder de indução de angiogênese e neoformação tecidual através de membranas de borracha natural de Hevea brasiliensis. Este trabalho apresenta um estudo sobre as propriedades e a caracterização das frações não isoprênicas, separadas por centrifugação do látex, utilizado como biomaterial na indução de angiogênese e de neoformação. As frações constituintes, F2 e F3 sem o tradicional agente estabilizante de hidroxido de amônio (NH4OH), foram liofilizadas para a redução da quantidade de água e estabilização, em seguida tratadas termicamente a temperatura de 40,60,80, 100, 120 e 140ºC e novamente liofilizadas, sendo caracterizada através das técnicas de Kjeldahl, Soxhlet, de espectroscopia de absorção no infravermelho (FT-IR), Ressonância Magnética Nuclear (RMn-13C). Difração de raios x (DRX), termogravimetria (TG) acoplado ao FT-IR (IG/FT-IR), calorimetria exploratória diferencial (DSC), eletroforese, dosagens de citocinas e síntese de óxido nítrico considerando o fator limitate do uso do látex como um material bioativo, que é a temperatura de tratamento térmico, realizado para a obtenção das membranas de borracha natural, em torno de 85ºC. Foi possível verificar que a fração F3 constituinte do látex, tem propriedades anti-inflamatórias e que a fração F2 possui propriedades pró-inflamatórias / Abstract: Currently it is proven the hability of inducing angiogenesis and tissue neoformating through membranes of natural rubber Hevea brasiliensis, so this work presents a study on the properties and characterization of non-isoprene fractions, separated by centrifugation, the latex used as biomaterial for induction and neoformation of angiongenesis and lyophilized without the traditional stabilizing agent, ammonium hydroxide (NH4OH). The fractions constituents, F2 and F3 fractions were lyophilized without the traditional stabilizing agent, ammonium hydroxide (NH4OH). The fractions constituents, F2 and F3 fractions were lyophilized to reduce the amount of water and stabilization, and then heat treated at temperature of 40, 60, 80, 100, 120 and 140ºC bieng characterized by the techniques of kjeldahl, Soxhlet, of absorption spectroscopy infrared (FT-IR), Nuclear Magnetic Resonance (NMR-13C), X-ray Diffraction (XRD), thermogravimetry (TG) coupled to FT-IR (TG-IR), differential scanning calorimetry (DSC), electrosphoresis, serum cytokines and oxide nitric (NO) considering the limiting factor in the use of latex as a bioactive material, which is the thermal treatment temperature, held for obtaining membranes of natural rubber, about 85ºC. It was possible to verify that the fraction F3 constituent latex has anti-inflammatory and the fraction F2 take inflammatory properties / Doutor
6

Rubber Content of Native Plants of the Southwestern Desert

Buehrer, T. F., Benson, Lyman 15 June 1945 (has links)
This item was digitized as part of the Million Books Project led by Carnegie Mellon University and supported by grants from the National Science Foundation (NSF). Cornell University coordinated the participation of land-grant and agricultural libraries in providing historical agricultural information for the digitization project; the University of Arizona Libraries, the College of Agriculture and Life Sciences, and the Office of Arid Lands Studies collaborated in the selection and provision of material for the digitization project.
7

An International Conference on the Utilization of Guayule: Proceedings of Meeting held at Tucson, Arizona, November 17-19, 1975

11 1900 (has links)
No description available.
8

Guayule Natural Rubber Commercialization: A Scale-Up Feasibility Study

Foster, Kennith E., Wright, N. Gene, Fansler, Susan Fitzgerald January 1991 (has links)
Conducted under USDA Agreement No. 58-3159-7-11 Guayule Natural Rubber Program / Introduction: The United States imports 100 percent of its natural rubber. Ninety-two percent of our natural rubber production is concentrated in Southeast Asia, which is subject to interruptions through political action or direct military intervention. Natural rubber, a critical and strategic material, is necessary in such articles as aircraft and ground vehicle tires, medical supplies, resilient mounts, and certain acoustical applications. Synthetic elastomers cannot meet performance requirements in these areas. A domestic source of natural rubber will assist in assuring a supply of this critical material for industry and defense. The U.S. Department of Defense (DoD) and the U.S. Department of Agriculture (USDA) signed a Master Memorandum of Understanding in 1982 that calls for cooperation with respect to food, agriculture, forestry, nutrition, and other research of mutual interest. With this MOU both agencies adopted a supplemental agreement in 1986 that initiated the Joint Guayule Domestic Rubber Program, whose ultimate goal is to promote an economically viable domestic guayule rubber industry. To accomplish this goal, both agencies have provided funding to plant and cultivate guayule shrubs, construct a 150 -long- ton -per -year prototype plant to extract rubber from the shrubs, and conduct evaluations to establish the performance capability of military products fabricated with domestic guayule rubber. A critical component of the supplemental agreement calls for the USDA to assess the feasibility of a commercial guayule rubber processing facility of 50,000-long-ton-per-year nameplace capacity. This report, based on the best available data (1990) and on assumptions of future advancements in technology (for 1996), is designed to address the commercial prospects for the establishment of a domestic guayule rubber industry. It also examines the feasibility and factors involved in meeting either 20 percent or 100 percent of the natural rubber needs of the U.S. Department of Defense in both peacetime and national emergency conditions.
9

Caracterização morfológica, cultural, molecular e enzimática de isolados de Fusarium spp., de Seringueira

Dória, Karolina Marie Alix Benedictte Van Sebroeck [UNESP] 14 December 2012 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:35:46Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-12-14Bitstream added on 2014-06-13T19:25:23Z : No. of bitstreams: 1 doria_kmabs_dr_botfca.pdf: 1440184 bytes, checksum: df65e19a8245aa12b6f0eb1ae9944257 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Dentro do setor florestal há diferentes culturas implantadas de forma comercial no Brasil, dentre elas destacam-se o eucalipto, o pinus e a seringueira. A produção nacional de borracha seca (oriunda da seringueira) cresceu mais de oito vezes nos últimos 18 anos, e chegou a 130 mil toneladas em 2010. A produção interna está concentrada em São Paulo (57,8%), Bahia (14,05%) e Mato Grosso (11,53%). Como em outras culturas de plantio, a heveicultura enfrenta inúmeros problemas com doenças, entre elas as doenças das folhas, tronco e painel. No presente trabalho, o objeto principal foi o estudo da fusariose, cujos sintomas se iniciam a partir de trincas na casca, a partir do porta-enxerto, e segue em direção ao painel, causando o secamento ao redor desta lesão. Com o passar do tempo esta lesão cresce em tamanho e a casca acaba se desprendendo, tornando a árvore imprópria para a sangria. Os objetivos específicos foram à caracterização dos isolados obtidos e o conhecimento das diversidades genética e patogênica de isolados oriundos das principais regiões produtoras de látex no Brasil, utilizando para isso: a) caracterização morfológica e cultural; b) estudo de agressividade dos isolados; c) teste de resistência clonal; d) efeito de fungicidas no controle in vitro; e) caracterização genética, através de sequenciamento de regiões gênicas com valor taxonômico, como a região ITS e f) produção in vitro de enzimas extracelulares. Nas coletas de isolados e levantamento de dados de campo, verificou-se alguns talhões com 49,20% de incidência de seca patológica, com árvores atacadas em agregados ou reboleiras e o patógeno se distribuindo mais no sentido da linha de plantio, o agente foi caracterizado a nível de gênero como Fusarium spp. que é um fungo mitospórico, da classe forma Hyphomycetes, que produz conídios... / In the Brazilian forestry sector there are different cultures, such as eucalyptus, pine and rubber, grown as a business. Domestic production of dry rubber (derived from the rubber tree) rose more than eight times in 18 years, and reached 130 thousand tons in 2010. Domestic production is concentrated in São Paulo (57.8%), Bahia (14.05%) and Mato Grosso (11.53%). As in other plantation crops, heveiculture faces numerous problems such as diseases, including diseases of the leaves, trunk and panel. In the present work, the main goal was the study of Fusarium, whose symptoms begin in the cracks in the bark, from the rootstock, and goes towards the panel, causing the bark around the injury to dry up. Over time the lesion grows in size and the bark ends up shedding, making the tree unsuitable for bleeding. Specific goals were characterizing the obtained isolates and cognition of the genetic and pathogenic diversity of isolates from the major latex producing regions in Brazil, using for this: a) morphological and cultural characterization b) study of the aggressiveness of isolates c) test of clonal resistance d) effect of fungicides on in vitro control e) genetic characterization by sequencing genic regions with a taxonomic value, such as the ITS region and f) in vitro production of extracellular enzymes. In the collections of isolates and survey field data, there were some plots with 49.20% of pathological incidence of drought, with trees... (Complete abstract click electronic access below)
10

Variabilidade genética de Colletotrichum gloeosporioides e Colletotrichum acutatum em seringueira (Hevea brasiliensis) no Brasil

Sierra Hayer, Juan Fernan [UNESP] 07 February 2014 (has links) (PDF)
Made available in DSpace on 2014-08-13T14:50:54Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-02-07Bitstream added on 2014-08-13T18:01:21Z : No. of bitstreams: 1 000766190.pdf: 2070584 bytes, checksum: 9a03514bca85630b682825636e50389c (MD5) / A seringueira [Hevea brasiliensis (Wild. ex Adr. de Juss.) Muell-Arg] é a maior fonte de borracha natural, amplamente cultivada, e de grande importância comercial devido a sua alta capacidade produtiva. Atualmente ela vem sendo atacada por várias doenças que causam enormes prejuízos econômicos. Dentre essas a antracnose, causada pelos fungos Colletotrichum gloeosporioides e Colletotrichum acutatum, está presente em todos os lugares heveícolas do mundo. Estes fungos causam vários danos na planta como lesões nos folíolos, nos ponteiros, nos ramos, nos frutos e cancros no painel de sangria. Diante desta situação e da alta incidência destes patógenos na cultura da seringueira, o presente trabalho teve como objetivo identificar a variabilidade genética dos isolados de C. gloeosporioides e C. acutatum associados à seringueira. Ferramentas filogenéticas e populacionais foram utilizados para determinar a distribuição e a frequência de cada um dos possíveis haplótipos. As 79 amostras coletadas em campo foram amplificadas por PCR com primers específicos das regiões espaçadores ITS e dos genes 18S, 28S e 5,8S. Posteriormente as regiões amplificadas foram sequenciadas pelo método Sanger. Para complementar as análises foram adicionadas sequências disponíveis no NCBI, totalizando uma matriz de dados de 263 amostras. As árvores geradas, a partir de análises filogenéticas Bayesiana, Máxima Verossimilhança e Neighbour-Joining, mostraram a divisão dos grupos de C. gloeosporioides e C. acutatum, possibilitando a separação da matriz em duas espécies específicas. As análises ... / The rubber tree [Hevea brasiliensis (Wild. ex Adr. Than Juss. ) Muell - Arg] is the largest source of natural rubber, widely cultivated, and of great commercial importance due to its high production capacity. Currently the rubber trees are being attacked for various diseases, causing huge economic losses. Among them, the anthracnose, caused by Colletotrichum gloeosporioides and Colletotrichum acutatum, is in all rubber crops places of the world. These fungi causes various damage, such as injuries on leaves, branches, fruits, as well as cankers in the taping panel. Given this situation, and the high incidence of this pathogen in the rubber crop, this study aimed to identify the genetic variability of the isolates of C. gloeosporioides and C. acutatum associated to rubber crop. Phylogenetic and population tools were performed to determine the distribution and frequency of each possible haplotypes. The 79 samples collected in the field were amplified by PCR by specific primers of the ITS spacers regions and the 18S, 28S and 5.8 S genes. Subsequently, the amplified regions were sequenced by the Sanger method. Several sequences available in NCBI were added, to complement the analysis, totaling a data matrix of 263 samples. Phylogenetic analyses generated by Bayesian, Maximum Likelihood and Neighbour -Joining methods, showed the division of the C. acutatum and C. gloeosporioides groups, enabling the separation of the matrix in two specific species. The population analysis showed some very common haplotypes distributed around the world, as well as another haplotypes with very restricted distribution, such as H1 haplotype of ...

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