Thesis (Ph. D.)--University of Wisconsin--Madison, 1939. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaf [15]).

Thesis (Ph. D.)--Worcester Polytechnic Institute. / Keywords: Water; Adsorption; Molecular simulation; Nanoporous materials. Includes bibliographical references (p. 117-119).

A primeira parte desta Tese incluiu a funcionalização em solução de polietileno linear de média densidade (LMDPE) com alil glicidil éter (AGE), na presença de peróxido de benzoíla (BPO) como iniciador de reações radicalares. A caracterização foi feita por espectroscopia no infravermelho com transformada de Fourier (FTIR) e o grau de funcionalização (GF) foi estimado por meio de duas curvas de calibração. Foi observado efeito do tipo de solvente sobre o GF. A segunda parte consistiu na funcionalização superficial por radiação ultravioleta (UV). Como monômeros foram usados AGE, anidrido maléico (MAH) e anidrido tetraidroftálico (THFAH). Como iniciadores, BPO e benzofenona (BP). A caracterização das superfícies foi realizada por medidas de ângulo de contato. THFAH apresentou a melhor performance. A terceira tratou da funcionalização por processamento reativo do LMDPE com AGE, na presença de BPO. A caracterização se deu por FTIR e o GF foi estimado conforme descrito acima. A funcionalização foi confirmada (indiretamente) por calorimetria diferencial exploratória, que evidenciou a diminuição do grau de cristalinidade com a funcionalização. Não foi possível confirmar a funcionalização por meio de análise elementar, termogravimetria e difração de raios X. A fragmentação das cadeias do LMDPE funcionalizado do ensaio 13 (e 13A) foi evidenciada por decréscimo no torque e nas propriedades mecânicas. Contudo, o índice de fluidez, surpreendentemente, diminuiu. Os valores relativamente superiores de resistência à tração e módulo de Young dos compósitos e blendas obtidos com LMDPE funcionalizado, contra os obtidos com LMDPE virgem, evidenciaram a interação favorável entre os grupos epóxidos inseridos nas cadeias do LMDPE e os grupos hidroxilas presentes no polissacarídeo. O aumento da adesão entre a matriz polimérica e as fibras de celulose foi confirmado por microscopia eletrônica de varredura e, qualitativamente, por quantidades relativamente maiores de resíduos remanescentes após extração em xileno sob refluxo. / The first part of this work included the functionalization in solution of linear medium density polyethylene (LMDPE) with allyl glycidyl ether (AGE), in the presence of benzoyl peroxide (BPO) as free radical reaction initiator. The characterization was made by Fourier transform infrared spectroscopy (FTIR) and the degree of functionalization was estimated by means of two calibration curves. The type of solvent influenced the DF. The second part comprised the surface functionalization by ultraviolet (UV) radiation. AGE, maleic anhydride (MAH) and tetrahydrophthalic anhydride (THFAH) were used as monomers and BPO and benzophenone (BP) as initiators. Contact angle measurements were used to characterize the surfaces. THFAH showed the best performance. The third part dealt with the functionalization by reactive processing of LMDPE with AGE, in the presence of BPO. FTIR was used to characterize the samples and the degree of functionalization was estimated as described above. The functionalization was (indirectly) confirmed by differential scanning calorimetry. The degree of crystallinity decreased with the functionalization. The functionalization couldn?t be confirmed by elemental analysis, thermogravimetry and X-ray diffraction. The chain scissions of the chemical modified LMDPE of trial 13 (and 13A) were evidenced by reduction of torque and mechanical properties. However, the melt flow index diminished. The favorable interaction between epoxide groups inserted on LMDPE chains and hydroxyl groups present in polysaccharide caused the increase in tensile strength and Young?s modulus values for composites and blends in relation to those obtained with virgin LMDPE. The increase in adhesion between the polymeric matrix and cellulose fibers was also confirmed by scanning electron microscopy and, qualitatively, by relatively large amounts of remaining residues after extraction in refluxing xylene.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / The objective of the present study was to evaluate the effect of diet substitution of maize silage by sunflower silage on performance and ingestive behavior of feedlot steers. Nine steers, with average initial live weight and age of 288 kg and 20 months, respectively, from Nellore (N), 21/32Charolais (C) 11/32N and 21/32N 11/32C genetic groups, were used. The tested diets were: SG0= roughage with 100% of maize silage and 0% of sunflower silage; SG33= roughage with 67% of maize silage and 33% of sunflower silage and SG66= roughage of 34% of maize silage and 66% of sunflower silage. For all diets, the roughage:concentrate ratio used was of 60:40. The substitution of maize silage by sunflower silage didn t influence (P>.05) dry matter, neutral and acid detergent fiber and digestible energy intakes. A significant difference (P<.05) was observed for ether extract, being the higher value for SG66 (.83kg/day), the intermediary for SG33 (.63 kg/day) and the lower for SG0 (.50 kg/day). The slaughter weight, average daily weight gain, final body condition, feed and energetic conversions weren t influenced (P>.05) by treatments. Steers fed with SG66 stayed more time ruminating (P<.05) in relation to SG33 and SG0 animals, being values of 9.45; 8.76 and 8.61 h, respectively for SG66; SG33 and SG0. Animals fed with SG0 presented better (P<.05) dry matter and detergent fiber rumination. The time spending with feeding was higher (P<.05) for SG0 (32.58 min), intermediary for SG33 (28.33 min) and lower for SG66 (23.46 min). / O objetivo do presente estudo foi avaliar a substituição da silagem de milho por silagem de girassol na dieta, através do desempenho e do comportamento ingestivo de novilhos confinados. Foram utilizados nove novilhos castrados, com peso vivo e idade média inicial de 288 kg e 20 meses, respectivamente, pertencentes aos grupos genéticos Nelore, 21/32Charolês (C) 11/32Nelore (N) e 21/32N 11/32C. As dietas testadas foram: SG0= volumoso com 100% de silagem de milho e 0% de silagem de girassol; SG33= volumoso com 67% de silagem de milho e 33% de silagem de girassol e SG66= volumoso com 34% de silagem de milho e 66% de silagem de girassol. A relação volumoso:concentrado utilizada foi 60:40 para todas as dietas. A substituição da silagem de milho por girassol não influenciou (P>0,05) o consumo de matéria seca, de fibra detergente neutro e ácido, de energia digestível. Houve diferença (P<0,05) no consumo de extrato etéreo, sendo maior para SG66 (0,83 kg/dia), intermediário para SG33 (0,63 kg/dia) e menor para SG0 (0,50 kg/dia). O peso de abate, o ganho de peso médio diário, o estado corporal final, a conversão alimentar e energética não foram influenciados (P>0,05) pelos tratamentos. Os novilhos alimentados com SG66 ruminaram por mais (P<0,05) tempo em relação aos animais que receberam SG33 e SG0, sendo os valores de 9,45; 8,76 e 8,61 h, respectivamente, para SG66; SG33 e SG0. Animais alimentados com SG0 apresentaram melhor (P<0,05) de ruminação da matéria seca e da fibra em detergente. O tempo de despendido por refeição foi maior (P<0,05) para SG0 (32,58 min), intermediário para o SG33 (28, 33 min) e menor para SG66 (23,46 min).

Afin d'obtenir une meilleure compréhension de l'étape clé du système photosynthétique (la formation d’un état à charges séparées), une nouvelle famille de systèmes donneur-accepteur supramoléculaires a été préparée.Nous avons notamment acquis une meilleure compréhension de la nature des interactions π-π entre le C60 et les porphyrines (résultant d'un processus régi principalement par des forces de van der Waals) et de l'affinité des éthers couronnes vis-à-vis des fullerènes (résultant d'une combinaison entre interactions π-π, n-π et CH-π). Les propriétés supramoléculaires des dimères de porphyrines ont été aussi explorées, prouvant leur communication électronique à travers leurs sous-unités. Finalement, la coopérativité chélate d'un de nos systèmes a été évaluée par la molarité efficace. / In order to gain a better understanding of the key step of the photosynthetic system (formation of a charged separated stated), a series of new supramolecular crown ether containing donnor-aceptor ensembles have been obtained.Notably we have gained further insight in the nature of π-π stacking between C60 and porphyrins (arising from a process mainly governed by van der Waals forces) and the affinity of crown ethers towards fullerenes(arising from an interplay of π-π, n-π and CH-π interactions). The properties of porphyrin arrays have been explored, evidencing the electronic communication through subunits. Finally, the chelate cooperativity of one our systems has also been assessed through the effective molarity.

Esta pesquisa teve como objetivo avaliar as diferenças nos padrões de desenvolvimento ponderal, composição de carcaça e qualidade de carne entre linhagens e touros representativos da raça Nelore, com aplicação de tecnologias modernas para coleta de dados e estimação de parâmetros genéticos e fenotípicos das características em estudo. Foram utilizados dados de desenvolvimento ponderal, características de carcaça e qualidade de carne de machos da raça Nelore, terminados a pasto e confinamento e pertencentes a programas de avaliação genética. Desses animais, foram coletadas informações individuais de características de carcaça avaliadas por ultrassonografia e medidas corporais para estimação do frame de cada animal. Ao abate, foram avaliadas características de carcaça e carne, diretamente na carcaça e também através de imagens digitais do músculo Longissimus para determinação de atributos relacionados à qualidade, como maciez, perdas por cozimento, gordura intramuscular e pH. Avaliações por infravermelho com comprimentos de onda na faixa do visível próximo (VIS-NIRS) foram tomadas para associação com valores de pH, força de cisalhamento e lipídios no músculo Longissimus. Foram estimados parâmetros genéticos para todas as características avaliadas neste trabalho. As características de ganho ponderal, frame, medidas de ultrassonografia e qualidade de carne foram utilizadas para comparação entre genearcas e novos genearcas da raça Nelore. Estas informações em conjunto com a validação ferramentas auxiliares para coleta de fenótipos poderão ajudar na condução de programas de melhoramento genético de características de desempenho e qualidade de nos rebanhos dessa raça, bem como a obtenção de importantes informações sobre a variabilidade e valor genético de genearcas e touros representativos da raça Nelore. / The objective of this study was to evaluate the differences of growth, carcass composition and beef quality traits among lineages and representative Nellore sires, using new technologies to collect data and estimate genetic and phenotypic parameters. Data on growth, carcass and meat quality traits of Nellore bulls, raised in pastures and included in genetic evaluation programs were analyzed. Individual information on live ultrasound carcass measurements and frame were, also, collected. After slaughter, carcass, beef quality traits and video image analysis (VIA) of muscle Longissimus were obtained for estimation of beef quality attributes like tenderness, cooking losses, intramuscular fat and pH. Evaluations with Near Infrared Spectroscopy (VIS-NIRS) were made to quantify tenderness and lipid in Longissimus muscle. Genetic parameters were estimated for all traits analyzed in this study. Traits like performance, frame, ultrasound carcass evaluation and meat quality were used to compare lineages and representative Nellore sires. This research provide precious information to development of auxiliary tools for genetic improvement of growth, carcass and meat quality traits in Nellore herds, and provide important information about variability and genetic value of founders and representative sires of this breed.

No description available.

This thesis deals with the stopping of hydration of alkali activated slag by organic solvents and investigates to what extent the selected organic solvent affects the results of the analyses. The solvents used were acetone, diethyl ether, ethanol, isopropanol and methanol, and this is because these are the most commonly used organic solvents in practice. Thermogravimetric analysis along with differential thermal analysis was used to assess the degree of influence of organic solvents on the alkali activated slag and Portland cement samples. Methanol and acetone affected the samples the most and the longer the sample was stored in the solvent, the more it reacted with the organic solvent. The adverse interaction of organic solvent was greatest for the Portland cement samples. Samples that were rinsed with diethyl ether prior to analysis had lower mass losses than samples that were not rinsed. In the case of alkali activated slag, it was found that the way in which the thermogravimetric results were affected by organic solvents was highly dependent on the activator used, with the smallest effect observed for Na2CO3 activation, while the largest effect was observed for NaOH activation at temperatures below 600 °C, and for higher temperatures for water glass activation.

The purpose of this thesis was to investigate how crown ethers behave and interact with different cations and to optimise the setup of the electrophoretic NMR. To get a good electrophoretic NMR measurement the electrophoretic phase shift needs to be big. To increase the phase shift some parameters needed to be adjusted, parameters such as the concentration of crown ether and cation, the duration of magnetic field gradient pulse δ, the magnetic field gradient strength g, the diffusion time Δ and the applied voltage V. The main focus then put on crown ethers 15-crown-5 and 18-crown-6. The cations used were lithium (Li), sodium (Na), potassium (K), caesium (Cs), calcium (Ca) and barium (Ba). The effective charge was obtained by using pulsed gradient NMR to derive the diffusion coefficient and electrophoretic NMR to get the electrophoretic mobility. These data were used to calculate the equilibrium constant of the formed complex. The outcome of the investigation: the affinity for 18-crown-6 was in the following order barium &gt; potassium &gt; caesium &gt; sodium &gt; calcium &gt; lithium and for 15-crown-5 barium &gt; sodium &gt; calcium &gt;  caesium &gt;  potassium &gt; lithium.

Lignin is the most abundant source of naturally occurring aromatic compounds but has mainly been considered as waste material or energy source in the pulp and paper industry. However, due to the drive to find new material applications derived from renewable resources, there are extensive research activities aiming to develop new routes to utilize this source toward novel polymer materials. In this project, cinnamyl alcohol was used as a benchmark substrate in determining the most favorable reaction conditions for the optimal dehydrative etherification of allylic alcohols. The optimal reaction conditions determined for cinnamyl alcohol aimed to be applied to the etherification of the structurally similar, lignin-derived coniferyl alcohol to produce a bio-based allylic ether of relevance for biomaterial applications. However, due to the COVID-19 pandemic, the investigation of the etherification of coniferyl alcohol could not be conducted and the project had to be limited to the synthesis of 2-phenylethyl cinnamyl ether. Thus, this project serves as a pre-study for the sustainable etherification of lignin-derived allylic alcohols of relevance for biomaterials. The optimal reaction conditions for the synthesis of 2-phenylethyl cinnamyl ether was concluded to be 0.25 M cinnamyl alcohol and 1.00 M 2-phenylethanol as initial concentration of the reactants, 0.02 M Zr(Cp)2(OTf)2 ∙ THF as initial concentration of the catalyst, benzotrifluoride as solvent, a reaction mixture temperature of 60 °C, and a reaction time of four hours. Using optimized reaction conditions, coniferyl alcohol, a lignin-derived allylic alcohol, could in further research be evaluated as a sustainably sourced allylating agent with potential for biomaterial purposes.