Thesis (Ph. D.)--University of Wisconsin--Madison, 1968. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin--Madison, 1971. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.

Thesis (PH. D.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 173-184). Also available on the World Wide Web.

Thesis (M.B.A.)--Boston University / Quality control as a concept and working tool in modern industry takes many shapes and forms. It is one of the more recent management tools to be incorporated into the complex manufacturing organizations in present day industry. There are almost as many different working concepts and definitions of quality control as there are industrial organizations. When attempting to define quality control, its purposes and objectives, we can find general agreement on its overall scope. W. A. MacCrehan defines quality as "a planned, continuing effort to maintain product quality in manufacturing". 1 A. V. Feigenbaum of General Electric Co., a noted authority in the field of quality control, goes a step further and defines it, "as an effective system for coordinating the quality maintainance and quality improvement efforts of the various groups in an organization so as to enable production at the most economical levels which allow for full customer satisfaction". These text definitions are generally carried over and incorporated in working company philosophies. The General Tire and Rubber Co. carries the following definition in its corporate manual for quality control: "Quality control is the act of assuring that outgoing product levels meet the established quality levels and of coordinating the activities of all departments in such a manner that established quality levels are maintained at the lowest possible cost" .3 This general concept of quality control, however, takes many varying manifestations when translated into specific working tools for use in the day to day activities of each industrial concern.

Made available in DSpace on 2014-06-11T19:25:32Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-08-21Bitstream added on 2014-06-13T18:53:40Z : No. of bitstreams: 1 gavari_lk_me_ilha_parcial.pdf: 85040 bytes, checksum: 73228359233872d55258f162234ca61e (MD5) Bitstreams deleted on 2014-08-22T14:57:11Z: gavari_lk_me_ilha_parcial.pdf,Bitstream added on 2014-08-22T15:02:12Z : No. of bitstreams: 1 000730478.pdf: 1256039 bytes, checksum: 7a614fac06d8bead69f000c6bd55a48c (MD5) Bitstreams deleted on 2016-01-12T18:57:28Z: 000730478.pdf,. Added 1 bitstream(s) on 2016-01-12T18:58:35Z : No. of bitstreams: 1 000730478_20181101.pdf: 76016 bytes, checksum: a383c7060536f713ed5f64fe1ead6a8a (MD5) Bitstreams deleted on 2018-11-01T18:31:48Z: 000730478_20181101.pdf,. Added 1 bitstream(s) on 2018-11-01T18:32:49Z : No. of bitstreams: 1 000730478.pdf: 1256036 bytes, checksum: 8830e64c83c68e9a02ff426d4a897522 (MD5) / Compósito de Borracha Natural e polianilina dopada com o ácido dodecilbenzenosulfonico foram obtidos por meio da polimerização in situ da anilina no látex de borracha natural, utilizando o persulfato de amônio como oxidante. Compósitos foram obtidos a partir de diferentes razões em massa de Borracha Natural/Anilina (BN/AN variando de 4 a 19) e caracterizados pelo método de duas e quatro pontas, espectroscopia ultravioleta-visível (UV-Vis-NIR), calorimetria diferencial de varredura (DSC), difratometria de raios-X (DRX) e microscopia eletrônica de varredura (MEV). A condutividade do compósito aumentou com a diminuição da razão BN/AN alcançando a ordem de 10-2 S/cm (BN/AN = 4), na qual é cerca de 10 ordens de grandeza maior do que a condutividade elétrica da borracha natural. Os espectros na região UV-Vis-NIR, demonstraram que a polianilina se encontra no estado de oxidação sal esmeraldina. Os difratogramas de raios-X mostraram que a polianilina sintetizada no meio látex apresenta planos cristalinos semelhantes às amostras sintetizadas em meio aquoso. Nas micrografias de MEV observou-se que a PAni-DBSA apresenta morfologia globular com boa dispersão na matriz BN, sendo a maioria com tamanho menores que 200 nm. A transição vítrea da borracha não foi alterada com o conteúdo de PAni observado nas análise de DSC. Os compósitos ternários de borracha natural com polianilina-DBSA e ferrita de bário foram também obtidos via da polimerização in situ da anilina, em meio látex de borracha natural contendo as partículas de ferrita de bário. Um expressivo aumento na absorção de energia eletromagnética no intervalo de 8 à 12 GHz, foi observada com a medida que a quantidade de ferrita foi aumentada na matriz. Para o compósito com a razão BN/AN = 12, a medida de refletividade máxima foi de -8 dB o que... / Composites of Natural Rubber with Polyaniline doped with dodceylbenzenesulphonic acid, were obtained by in situ polymerization of aniline in natural rubber latex medium using ammonium peroxydisulfate - (NH4)2S2O8 - as oxidant. The composites were obtained for different mass ratio of Natural Rubber/Aniline (NR/AN) in the range of NR/AN = 4 to 19 and characterized by four and two probe electrical conductivity, ultraviolet-visible-near infrared spectroscopy (UV-Vis-NIR), differential scanning calorimetry, scanning electron microscopy and X-ray diffraction. The electrical conductivity increase as NR/AN ratio decrease, reaching around 10-2 S/cm (NR/AN = 4) which is 1012 of magnitude higher than pure natural rubber. UV-Vis-NIR spectrum showed that polyaniline synthesized in latex medium is in its emeraldine salt form. The X-ray pattern showed that the polyaniline synthetized in latex medium has the same crystal planes of the synthesized in an aqueous medium. The scanning electron microscopy micrograph showed globular morphology of PAni-DBSA phase, uniformly distributed in the NR matrix with size mostly smaller than 200nm. The glass transition temperature was unaffected by the PAni amount in the NR matrix according to differential scanning calorimetry thermograms. Ternary composites of NR with PAni-DBSA and Barium Ferrite were also obtained by in situ polymerization of aniline in latex medium containing Barium Ferrite particle. Considerable increase in the reflection loss, in the range of 8 to 12 GHz, was observed increasing the amount of Barium Ferrite in the rubber matrix. For the composite NR/AN=12 the maximum reflection loss was -8 dB which correspond to 84 % of absorbed energy. Adding 20wt% of Barium Ferrite, related... (Complete abstract click electronic access below)

A prototype agroforestry system, which combined the low-input features and environmental benefits of the traditional Indonesian multi-species 'jungle rubber' system with high yielding rubber clones developed in monoculture plantations, was tested under on-farm conditions. Secondary forest was allowed to regenerate between weeded rows of clonal rubber. Clonal rubber establishment was studied, and the interactions between it, secondary forest species and farmer management were investigated using a combination of researcher- and farmermanaged weeding trials. In one trial, alteration of below-ground resources (using root barriers and trenches to create three soil volumes) did not affect above or below-ground growth of clonal rubber, although weeding significantly increased stem diameter and volume. It was concluded that secondary forest regrowth interfered with resource capture at the level of individual roots; interference was not due to depletion of total available resources. Shoot:root ratios and ratios of horizontally- to vertically-oriented proximal roots were not affected by weeding. Growth of clonal rubber in N-fertilised plots, in the presence of weeds, was significantly greater than in corresponding unfertilised plots, indicating that N-addition may overcome some negative effects of competition in the system. However, a bioassay of nutrient limitation showed no significant differences in root biomass or root-length density, for either rubber or weed rootingrowth into soil cores enriched with various nutrients. The second researcher-managed trial, on steep slopes, showed that the survival rate of clonal rubber was 33% higher than that of the 'seedling' rubber variety traditionally used, and that mean stem height and diameter of clonal rubber trees were significantly greater than those of seedling rubber, 21 months after planting. Damage to trees by banded leaf monkeys (Presbytis melalophos nobilis) and feral pigs (Sus barbatus) was severe, unexpected, and greater for seedling than for clonal rubber. For undamaged trees, weeding frequency within the rubber-tree row had no significant effect, indicating that the major influence on rubber tree growth was interference from secondary forest regrowth between rows, operating both aboveand below-ground. In a farmer-managed, trial, vertebrate pest damage was the major influence on clonal rubber establishment, explaining almost 70% of the variation in rubber growth. The amount of labour invested in weeding was positively correlated with rubber growth. However, fanners generally decided to completely cut back the secondary forest regrowth between rows of rubber trees, including potentially valuable trees, rather than weeding within the rows and selectively pruning inter-row trees. Farmers considered that the inter-row vegetation may harbour vertebrate pests and compete with the clonal rubber, and they had access to fruits, firewood and non-timber forest products on other land. Thus, contrary to expectations, when offered clonal germplasm, these 'progressive' farmers opted to use plantation methods to protect what they considered a valuable asset suited to monoculture, rather than maintain the traditional multispecies strategy they use with local germplasm. Thus, although clonal rubber can technically be established in a 'jungle rubber'-like system (albeit with lower growth rates than achieved in plantations), not all farmers may be prepared to adopt this type of system.

No description available.

Made available in DSpace on 2014-06-11T19:25:32Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-02-29Bitstream added on 2014-06-13T19:53:25Z : No. of bitstreams: 1 sanches_ao_me_ilha_parcial.pdf: 112225 bytes, checksum: a627f8885c53db81f69c1f28e2674083 (MD5) Bitstreams deleted on 2015-03-16T11:30:17Z: sanches_ao_me_ilha_parcial.pdf,Bitstream added on 2015-03-16T11:31:02Z : No. of bitstreams: 1 000711534.pdf: 2034833 bytes, checksum: 302e3bad38c6ea4df6f7ff1742ba16c2 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Compósitos de borracha natural vulcanizada (BV) e Titanato Zirconato de Chumbo (PZT) em diferentes composições foram obtidos a partir do látex pré-vulcanizado e da cerâmica PZT na forma de pó. As composições estudadas foram 90/10, 80/20, 70/30 e 60/40 v/v. Um aumento no coeficiente piezoelétrico (d33) foi verificado com o aumento do volume de cerâmica no compósito, atingindo um valor de aproximadamente 6 pC/N para compósitos de composição 60/40 polarizados a 8MV/m na temperatura de 90°C. Verificou-se um decaimento da atividade piezoelétrica em função do tempo após a polarização para os compósitos com até 30% em volume de cerâmica. Este decaimento foi atribuído principalmente à relaxação da matriz. A adição de nanofibras de celulose para a composição 70/30 nas proporções 5,10 e 15% em massa (em relação à massa da borracha), inibiu o processo de relaxação, como também promoveu uma melhor transferência de tensões mecânicas aplicadas no material aos grãos cerâmicos, ocasionando em um aumento de até 400% nos valores obtidos para o coeficiente piezoelétrico. A incorporação de 5% em massa de nanofibras recobertas com polianilina aumentou três ordens de grandeza a condutividade elétrica dos compósitos 70/30 e 60/40. Por outro lado, uma redução nos valores do coeficiente piezoelétrico foi observada, o que foi atribuído a um efeito de blindagem elétrica dos grãos cerâmicos / Vulcanized natural rubber(VNR) and Lead Zirconate Titanate (PZT) composites with different composition were obtained by mixing PZT ceramic powder with prevulcanized latex. The investigated composition of VNR/PZT were 90/10, 80/20, 70/30 and 60/40 v/v. The piezoelectric coefficient d33 increased with increasing of PZT volume fraction in the composite reaching approximately 6 pC/N for composites composition 60/40 %v/v, polarized with 8MV/m at 900C. It was verified that piezoelectric activity decay as a function of time for composite up to 30% of ceramic, that was attributed mainly to matrix relaxation. The incorporation of cellulose nanofibers in the compositions 70/30 and 60/40 %v/v inhibited the matrix relaxation besides of promoting better transference of the applied mechanical stress on the ceramic grains, increasing the piezoelectric coefficient d33 about 400%. The electrical conductivity of composites 70/30 and 60/40 increased three order of magnitude by adding 5% in mass (related to rubber mass), of cellulose nanofiber coated with polyaniline in the composite. On the another hand, the piezoelectricity activity d33 decreased and this behavior was attributed to electrical field shielding of ceramic grain promoted by coated fibers

Made available in DSpace on 2014-06-11T19:32:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-09-05Bitstream added on 2014-06-13T20:42:50Z : No. of bitstreams: 1 silva_mj_dr_ilha.pdf: 3897170 bytes, checksum: 3925fdc558f8229f09ef385d50600cc9 (MD5) / Nanowhiskers de celulose (CNF) foram obtidas de microfibras de algodão comercial (MFC) por meio de hidrólise ácida e recobertas com polianilina (PANI) via polimerização “in situ”, visando a obtenção de amostras condutoras (CNF-PANI). Nanocompósitos de Borracha Natural (BN) com nanowhiskers (nanofibras) recobertos e não recoberto com PANI também foram obtidos em diferentes proporções em massa, pelo método casting/evaporação, nas proporções em massa 97/03, 95/05, 93/07 e 90/10. Os nanocompósitos foram caracterizados utilizando as técnicas de espectroscopia UV-Vis-NIR, FTIR, DSC, TG/DTG, difratometria de raios-X, MEV-FEG, ensaios de mecânicos em tração e medidas elétricas dc e ac. Pelas as análises elétricas as amostras de CNF-PANI, alcançaram condutividade da ordem de 10-1 S/cm independente do ácido dopante utilizado (DBSA ou HCl). As CNF-PANI também apresentaram estabilidade térmica maior do que as CNF não recobertas, pois a PANI atua como uma barreira protegendo as CNF. Nas análises de TG/DTG foi observado que a estabilidade térmica dos nanocompósitos de BN/CNF e BN/CNF-PANI apresentaram comportamento semelhantes ao da BN. A temperatura de transição vítrea dos nanocompósitos foi similar ao da BN (-63 °C) não sofrendo mudança com a introdução de CNF e de CNF-PANI. A introdução de CNF e CNF-PANI impactaram positivamente nas propriedades mecânicas da BN devido ao fenômeno de percolação mecânica dos nanowhiskers que formam uma rede contínua na matriz de nanopartículas unidas por meio de ligações de hidrogênio. Os nanocompósitos reforçados com CNF (BN/CNF) exibiram maior módulo de Young e resistência mecânica na ruptura, do que os nanocompósitos BN/CNF-PANI. Já as análises elétricas demonstraram que a condutividade elétrica dos nanocompósitos... / Cellulose nanowhiskers (CNF) were isolated from cotton microfibrils (MCF) by acid hydrolysis and coated with polyaniline (PANI) by in situ polymerization of aniline onto CNF to produce conductive nanocomposite (CNF-PANI). Nanocomposites of natural rubber (NR) reinforced with CNF and CNF-PANI also were obtained by casting/evaporation method. The samples were characterized by ac and dc electrical conductivity, UV-Vis-NIR and Fourier-transform infrared (FTIR) spectroscopies, X-ray diffraction, DSC, TGA/DTG, SEM and strain-stress technique. Electrical conductivity about 10-1 S/cm was achieved for the CNF-PANI nanocomposites independent of dopant acids (DBSA or HCl). The nanowhiskers coated with PANI shown to be more thermally stable than the uncoated CNF, because the PANI acts as a barrier protecting the CNF. The NR/CNF and NR/CNF-PANI nanocomposites and neat NR sample showed the same thermal profiles. The glass transition temperature of the NR was not affected by nanowhiskers content. The mechanical properties of natural rubber improved with nanofibrils incorporation. Young’s modulus and tensile strength were higher for NR/CNF than the NR/CNF-PANI nanocomposites, probably because the CNF is more hydrophobic than CNF-PANI. The electrical conductivity of natural rubber increased five and seven orders of magnitude for NR with 10 wt% of CNF-PANI(HCl) and CNF-PANI(DBSA) content, respectively. A partial PANI dedoping might be responsible for the low electrical conductivity of the nanocomposites compared to CNF-PANI (HCL and DBSA). A statistical model of a resistor network was developed to simulate the structure and reproduced the ac conductivity of the NR/CNF-PANI nanocomposite by the application of a transfer-matrix technique. According to the simulation results, the conduction process between two sites of... (Complete abstract click electronic access below)