No description available.

Radiata pine is a major plantation grown wood in the Southern hemisphere, but has inferior dimensional stability and low durability compared to other commercial species and the improvement of these features is the focus of this thesis. Specifically this thesis examines the dimensional stability, durability and mechanical properties of radiata pine after heat-treatment (160-210°C) in linseed oil. Changes in colour, micro-structure and chemistry with heat-treatment were studied. To optimise the treatment results, oil heat-treatment of wood was also carried out after thermo-mechanical compression of wood and the effect of the prior thermo-mechanical compression on stability, durability and mechanical properties were examined. The oil heat-treated wood turned uniformly darker in colour. The hydrophobicity (Water Repellence Efficiency-WRE up to 30%), dimensional stability (Ant-Swelling Efficiency-ASE up to 60%) and fungal resistance (up to 36%) were improved with the extent of the changes mainly depending on treatment temperature. However, the mechanical properties of oil heat-treated wood were reduced compared to the untreated control group. Accelerated UV weathering tests have shown that the oil heat-treated wood retained its colour and dimensional stability better than the untreated wood (the control group). The cell wall of treated wood was intact and no distinct structural changes were observed even at the most severe treatment (210°C for 6 hrs).The treatment resulted in changes to the wood chemical constituents, mainly the degradation of hemicelluloses which is believed to be principal reason for alterations in wood properties. A study of the effect of prolong heating on the linseed oil showed an increase in viscosity with heating time which in turn reduced the oil uptake and water repellency of treated wood. However, no significant difference in the colour and dimensional stability of the treated wood was noticed with oil of different heating ages. Oil absorbed by the wood during heat treatment was removed by organic solvent extraction and its contribution to the weight percentage change and moisture related properties were evaluated. The oil uptake percentage, determined by organic solvent extraction, was greater than the weight percentage loss that was deduced to occur during the heat treatment phase, which was attributed to mass losses or thermal degradation of wood constituents. Moisture excluding efficiency decreased after removal of the oil from treated wood, which suggested that the hydrophobicity of treated wood is affected by oil absorbtion. The influence of the post-treatment cooling period on properties of treated wood was studied separately. Oil uptake increased substantially with the post-treatment cooling time which in turn affected the hydrophobicity of treated wood although this effect was less important to dimensional stability. The loss of mechanical properties due to heat-treatment was successfully countered by thermo-mechanical compression of wood prior to the oil heat-treatment. The wood was compressed to 39% of its original thickness without any visible surface checks and cracks. Spring back and compression set recovery in densified wood decreased after oil heat-treatment. This combination treatment also resulted in improved fungal resistance compared to untreated wood. From this research, it is concluded that oil heat-treatment of radiata pine wood can improve its dimensional stability and durability obviating the need to introduce any persistent toxic chemicals. Thermo-mechanical densification of wood prior to oil heat-treatment can countered the loss of mechanical properties due to heat-treatment. The heating oil can be re-used in subsequent treatments and oil uptake can be minimised by limiting the post-treatment cooling time without any significant effect on the dimensional stability of treated wood.

Linseed oil (Linum usitatissimum L.) is valued for its food and non-food applications. Although Canada is the world’s largest linseed producer and exporter, linseed remains a minor crop in part because its yield has been stagnating over the last decade compared to other oilseeds. Narrow genetic base, absence of an efficient hybrid production system and limited genomic tools for linseed breeding are the main factors hindering yield and quality improvements. Here, we characterized the Canadian flax core collection of 407 accessions with 448 genome-wide simple sequence repeat markers and, using association mapping (AM), we demonstrated its potential for the improvement of seed quality and agronomic traits. Genetic structure analyses assigned all accessions to two major groups that were weakly differentiated (FST = 0.094). Genetic diversity was abundant in the total panel (5.32 alleles per locus) with weak familial relatedness (mean = 0.287) for most individual pairs. Linkage disequilibrium (LD) decayed relatively quickly with an average genome-wide LD of ~1 cM. AM for seven seed quality traits including oil content (OIL), palmitic acid (PAL), stearic acid (STE), oleic acid (OLE), linoleic acid (LIO), linolenic acid (LIN) and iodine value (IOD) identified nine stable candidate QTL. LIO and LIN QTL co-localized with previously identified QTL and some mapped in the vicinity of genes known to be involved in the fatty acid biosynthesis pathway. AM conducted for nine agronomic traits including yield, bolls per area (BPA), seeds per boll (SPB), thousand seed weight (TSW), start of flowering (FL5%), end of flowering (FL95%), plant height (PH), plant branching (PB) and lodging (LDG) identified twelve significant marker-trait associations for six of the traits. The associated markers explained between 0.5 to 18.5% of the phenotypic variation, with Lu526 and Lu2532 associated with TSW and Lu943 associated with flowering being the most promising for marker-assisted selection. Statistical simulation for five markers associated with TSW indicated that the favorable alleles have additive effects. None of the accessions carried the five favorable alleles but a few breeding lines had four, indicating that further improvement of TSW and yield could be achieved through marker assisted breeding

Diss. (sammanfattning) Uppsala : Sveriges lantbruksuniversitet, 2008. / Härtill 5 uppsatser.

Thesis (M.S.)--West Virginia University, 2009. / Title from document title page. Document formatted into pages; contains vii, 115 p. : ill. (some col.). Includes abstract. Includes bibliographical references.

Thesis (M.S.)--West Virginia University, 2006. / Title from document title page. Document formatted into pages; contains v, 33 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 30-33).

AN ABSTRACT OF THE THESIS OF TITLE: THE EFFECT OF SUPPLEMENTING GRAZING DAIRY CATTLE DIETS WITH FISH OIL AND LINSEED OIL ON MILK CLA AND OMEGA-3 FATTY ACID CONTENT In the recent years, there has been considerable interest in the potential health-promoting properties of both conjugated linoleic acid (cis-9, trans-11 CLA), a fatty acid produced naturally in ruminant animals, and omega-3 fatty acids. The objectives of this research were to evaluate the effects of supplementing grazing dairy cows' diet with fish oil(FO)-linseed oil(LO) blend on milk cis-9, trans-11 CLA and omega-3 fatty acids milk content. In experiment one, fourteen lactating Holstein cows were randomly assigned to one of two treatment groups (7 cows/treatment) and fed either a control or oil supplemented diet for 21 d. Treatment groups were: 1) confinement cows with free access to corn silage and hay mix plus 10 kg/d (DM basis) grain mix supplementation (CONT), or 2) grazing cows with free access to grass pasture plus 10 kg/d grain mix supplementation containing 300 g FO plus 700 g LO (FOLO). Milk samples were collected during the last 3 d of the study and analyzed for chemical and fatty acid composition. Milk production (37.05 vs. 37.29 kg/d), milk protein percentages (3.16 vs. 3.21), and milk protein yield (1.05 vs. 1.25 kg/d) were not affected (P > 0.05) by treatment diets. Milk fat percentages (3.71 and 2.28) and yield (1.25 and 0.87 kg/d) were higher (P < 0 .05) with the CONT group. The concentrations of cis-9, trans-11 CLA (0.29 vs. 2.56 g/100g fatty acid) and vaccenic acid (VA; 0.81 vs. 7.14 g/100g fatty acid) in milk fat were higher (P < 0.05) with the FOLO group. The concentrations of milk omega-3 C18:3n3, C20:5n3, and C22:6n3 were also higher (P < 0.05) with the FOLO group. In experiment two, eighteen lactating Holstein cows who were randomly assigned to one of three treatment groups for 21 d. Treatment groups were 1) indoor cows with free access to corn silage and alfalfa hay plus 10 kg/d (DM basis) grain mix supplementation (CONT), 2) indoor cows with free access to corn silage and alfalfa hay plus 10 kg/d grain mix supplementation containing 300 g FO plus 700 g LO (FOLO), and 3) grazing cows with free access to grass pasture plus 10 kg/d grain mix supplementation containing 300 g FO plus 700 g LO (FOLOP). Milk samples were taken from each cow during the last 3 d of the study. Milk production, milk protein percentages and milk protein yield were not affected (P > 0.05) by treatment diets. Milk fat percentages (3.55, 2.85, and 2.39) and yield (1.20, 0.98, and 0.84 kg/d) were lower (P < 0 .05) among the oil supplemented cows with cows on the FOLOP diet having the lowest values. Concentrations of milk cis-9 trans-11 CLA (0.33, 1.78, and 2.94 g/100g fatty acid) and VA (0.83, 5.09, and 7.15 g/100g fatty acid) were higher (P < 0 .05) among the oil supplemented cows and they were highest with cows on the FOLOP diet. Concentration of milk omega-3 fatty acids (0.5, 1.11, and 1.47 g/100g fatty acid) were higher (P < 0.05) among oil supplemented cows and was also highest for cows on the FOLOP diet. In conclusion cows fed diets containing the FO-LO blend resulted in higher milk concentrations of cis-9, trans-11 CLA and omega-3 fatty acids when compared to cows fed the CONT diet. However, greatest increases in cis-9, trans-11 CLA and omega-3 concentrations in the milk were achieved when the FO-LO blend was fed along with grazing.

Objetivou-se nesse trabalho avaliar os efeitos de fontes de óleo vegetal na dieta de bovinos Nelore em fase de terminação sobre a aceitação sensorial, teores de colesterol e óxidos de colesterol, composição de ácidos graxos e estabilidade oxidativa de hambúrgueres bovinos, avaliados após serem congelados e acondicionados a -18°C por 90 dias, então avaliados crus e grelhados. Foram confinados 96 bovinos, machos, castrados, Nelore, com aproximadamente 380 kg de peso inicial e idade média de 24 meses, alimentados com óleos de soja, girassol, linhaça e tratamento controle sem adição de óleo por 82 dias. A partir do músculo Longissimus e da gordura subcutânea dos animais foram produzidos hambúrgueres Os hambúrgueres produzidos com carne de bovinos que receberam óleo de soja tiveram maior estabilidade lipídica, tanto para zero quanto para 90 dias de armazenamento quando comparado às outras dietas. O método cru de preparo também resultou em menores valores tanto para o tempo zero quanto para o tempo 90 dias de armazenamento, em relação ao método grelhado. Os hambúrgueres dos animais alimentados com o óleo linhaça resultaram em menores valores para o atributo sabor. O tempo zero dias de armazenamento dos hambúrgueres resultou em maiores notas dos consumidores para a textura e aceitabilidade global, em relação às amostras armazenadas por 90 dias. A porcentagem de ácidos graxos polinsaturados foi reduzida, independente dos tratamentos, após 90 dias de armazenamento. O CLA c9 t11 foi encontrado em maiores quantidades nas amostras dos animais alimentados com os óleos de linhaça e soja, para zero e 90 dias de armazenamento. O teor de colesterol aumentou após as amostras de hambúrgueres serem grelhadas, enquanto que não foi observado efeito para as fontes de óleos e os tempos de armazenamento. Foi observada a presença de óxidos de colesterol após as amostras serem armazenadas por 90 dias, independente das fontes de óleos utilizadas. O fornecimento de óleos insaturados para bovinos confinados aumenta a porcentagem de ácidos graxos polinsaturados em hambúrgueres produzidos com carne e gordura desses. A inclusão de óleos vegetais para bovinos aumenta a oxidação lipídica de hambúrgueres produzidos a partir de carne e gordura provenientes desses animais quando comparados a um tratamento sem inclusão de óleos vegetais. Hambúrgueres produzidos com carne e gordura de animais alimentados com óleos vegetais na dieta possuem maior oxidação lipídica após 90 dias de armazenamento quando comparados com os hambúrgueres do tempo zero e dos hambúrgueres do tratamento controle enquanto que o processamento térmico não foi responsável pela maior oxidação lipídica. / The aim of this study was to evaluate the effects of vegetable oil sources in Nellore diet in the finishing phase of the sensory analysis, cholesterol analysis and cholesterol oxides, fatty acid composition and oxidative stability of beef burgers, raw and packaged grilled at -18 ° C in two stages (storage for zero and 90 days). 96 cattle were confined, castrated male, Nellore, with about 380 kg of initial weight and average age of 24 months, fed soybean oil, sunflower, linseed and a control treatment without oil for 82 days. From the Longissimus muscle and subcutaneous fat of animals burgers were produced. The beef burgers receiving soybean oil had higher lipid stability for both zero and 90 days of storage as compared to other diets. The raw patties resulted in lower values for zero as well as 90 days of storage compared to the grill method. The animal burgers fed the flaxseed oil resulted in lower values for the attribute flavor. The burgers of storage time zero days resulted in higher grades by consumers for texture and overall acceptability compared to the samples stored for 90 days. The percentage of polyunsaturated fatty acids was decreased, regardless of the treatment after 90 days of storage. The CLA c9 t11 were found in larger quantities in samples of animals fed with linseed and soybean oils, and 90 to zero days of storage. The cholesterol content increased after samples of burgers were grilled, while there was no effect for the sources of oils and storage times. The presence of cholesterol oxides was observed after the samples were stored for 90 days, independent of the used oil sources. The supply of unsaturated oils to feedlot cattle increases the percentage of polyunsaturated fatty acids in hamburgers produced from meat and fat of these animals. The addition of vegetable oils for cattle increases lipid oxidation in hamburgers produced from meat and fat from these animals when compared to a treatment without addition of vegetable oils. Hamburgers produced from meat and fat animals fed with vegetable oils in the diet have higher lipid oxidation after 90 days of storage compared to burgers with zero storage time and the control treatment burgers, while the heat process is not responsible for the higher lipid oxidation.

A corrosão nos materiais metálicos causa sérias perdas financeiras e impactos ambientais. Apesar de eficientes, os revestimentos orgânicos podem gerar fissuras com o tempo, propiciando locais favoráveis à corrosão. Diante disso, o conceito de autorreparação em revestimentos tem sido estudado, para que este tipo de dano seja minimizado, sem necessitar da intervenção humana. O método de encapsulamento de formadores de filme em microcápsulas poliméricas é bastante utilizado nos sistemas de autorregeneração. Neste trabalho, estudou-se o processo de emulsificação do óleo de linhaça, etapa determinante para a obtenção das microcápsulas, que serão posteriormente aditivadas em um primer de epóxi base água. Inicialmente, foi necessário aperfeiçoar o preparo da emulsão, analisando-se para isso três tipos diferentes de tensoativos em termos de propriedades e composições. Foi feito um planejamento estatístico no qual se adotou o modelo de projeto fatorial completo para cada um dos tensoativos, onde os fatores analisados foram a variação da fração mássica do tensoativo, a aplicabilidade do ultrassom ou dispersor Ultra-Turrax® e a adição ou não de cloreto de sódio. O pequeno número de ensaios envolvidos e a simplicidade para se analisar e interpretar os dados justificam a escolha deste modelo. As variáveis resposta foram a determinação do diâmetro médio volumétrico das gotículas e a medida do potencial zeta das emulsões para analisar a estabilidade das mesmas. Além disso, observou-se a forma, tamanho e característica das gotículas com o auxílio de um microscópio óptico. A estabilidade da emulsão também foi avaliada pela observação e registro fotográfico da separação de fases, depois de certo tempo em repouso, em um tubo de ensaio. Após a determinação do melhor tensoativo e condições de preparo da emulsão na obtenção das microcápsulas, estas foram obtidas e adicionadas no primer e o mesmo foi aplicado sobre corpos de prova de aço carbono. O efeito de autorreparação proporcionado pela ruptura das microcápsulas ao se provocar um defeito foi avaliado pelas técnicas de espectroscopia de impedância eletroquímica (EIS), técnica de varredura com eletrodo vibratório (SVET) e pelo ensaio acelerado de corrosão em câmara de névoa salina (SSC). As microcápsulas foram caracterizadas por microscopia óptica e microscopia eletrônica de varredura (SEM). / The corrosion of metallic materials causes serious financial losses and environmental impacts. Although efficient, organic coatings may generate cracks over time, generating potential sites for corrosion. Hence, the self-healing concept on coatings has been studied in order to minimize this type of damage, without requiring human intervention. The encapsulation method of film formers in polymeric microcapsules is widely used in self-healing systems. In this study, the emulsification process of linseed oil was investigated, since it is a determining step to obtain the microcapsules that will later be doped in a water based epoxy primer. Initially, it was necessary to improve the emulsion preparation, by analyzing three types of surfactants with different properties and compositions. A statistical planning adopting the full factorial design model was conducted for each of the surfactants, in which the factors considered were the variation of the weight fraction of surfactant, and the use or not of ultrasound, Ultra-Turrax® disperser and sodium chloride. The small number of trials involved and the simplicity to analyze and interpret the data justify the choice of this statistical model. The response variables were the determination of the droplet volumetric mean diameter and the measurement of the zeta potential of the emulsions to assess its stability. Moreover, the shape and characteristics of the droplets were observed with the aid of an optical microscope. The emulsion stability was also evaluated by observation and photographic register of phase separation after some rest time in a test tube. After determining the best surfactant and conditions for the emulsification to obtain the microcapsules, they were produced and added to the primer, which was applied on carbon steel specimens. The self-healing effect provided by the rupture of the microcapsules after an intentional defect was evaluated by electrochemical impedance spectroscopy (EIS), scanning vibrating electrode technique (SVET) and accelerated corrosion tests in a salt spray chamber (SSC). The microcapsules were characterized by optical and scanning electron microscopes (SEM).

O objetivo deste trabalho foi avaliar os efeitos de dois modificadores metabólicos, a sesamina, presente no óleo de gergelim, e ácido alfa-lipoico (na forma pura), sobre desempenho zootécnico, perfil de ácidos graxos, composição química dos filés de pacus e alterações histológicas no fígado. Foram utilizados 480 juvenis de pacu (3,35±0,78 g), distribuídos em 24 caixas de polietileno com volume de 50 litros, sendo estocados 20 peixes em cada unidade. Durante o período experimental de 90 dias, a temperatura média da água permaneceu em 26 °C e os demais parâmetros (amônia, nitrito, pH e oxigênio dissolvido) apresentaram-se dentro dos níveis adequados para o desenvolvimento desta espécie. O delineamento experimental foi inteiramente casualizado, no qual foram avaliados seis tratamentos em esquema fatorial 3x2, sendo três níveis do fator óleo (OS: óleo de soja; OG: óleo de gergelim; OL: óleo de linhaça) e dois níveis do fator ácido alfa-lipoico (AAL) (sem e com), resultando em seis tratamentos: T1: OS (controle); T2: OG+OL; T3: OL; T4: OS+AAL; T5: OG+OL+AAL e T6: OL+AAL. Os dados obtidos foram analisados estatisticamente por análise de variância (ANOVA) e diferenças significativas foram verificadas pelo teste de Tukey (5%). As dietas contendo OL como única fonte lipídica (T3 e T6) proporcionaram melhores índices de peso médio (PM) e ganho de peso individual (GPI) nos juvenis de pacu. Além disso, proporcionaram maiores (P&lt;0,05) teores de ácidos graxos poli-insaturados (AGPI) da família n-3 nos filés, especialmente do ácido eicosapentaenoico (EPA, 20:5n-3). A única variável da composição química dos filés dos juvenis de pacu que apresentou diferença (P&lt;0,05) foi o teor de proteína bruta, sendo maior nos filés dos peixes alimentados com as dietas sem ácido alfa-lipoico (T4, T5 e T6). Os óleos utilizados nas dietas experimentais não causaram alterações nas células dos fígados de juvenis de pacu. Conclui-se que a sesamina, fornecida por meio de óleo de gergelim, não promoveu alterações no desempenho zootécnico dos pacus, nem na composição química e metabolismo de ácidos graxos poli-insaturados (AGPI) dos filés de juvenis de pacu. A presença do ácido alfa-lipoico não afetou o desempenho zootécnico dos animais e sua ausência promoveu maiores teores de proteína bruta e ácidos graxos poli-insaturados nos filés dos pacus. / The objective of this work was to evaluate the effects of two metabolic modifiers, sesamin, present in sesame oil, and alpha lipoic acid (in pure form), on pacus growth performance, fatty acid profile, chemical composition of pacus fillets and histological alterations in the liver. We used 480 pacu juveniles (3.35±0.78 g), distributed in 24 boxes of polyethylene with volume of 50 liters, being stored 20 fish in each unit. During the experimental period of 90 days, the mean water temperature remained at 26 °C and the other parameters (ammonia, nitrite, pH and dissolved oxygen) were in the appropriate levels for the development of this species. The experimental design was completely randomized, in which six treatments were evaluated in a 3x2 factorial scheme, being three levels of the factor oil (OS: soybean oil, OG: sesame oil, OL: linseed oil) and two levels of the alpha acid factor -lipoic acid (AAL) (without and with), resulting in six treatments: T1: OS (control); T2: OG+OL; T3: OL; T4: OS+AAL; T5: OG+OL+AAL and T6: OL+AAL. Data were analyzed statistically by analysis of variance (ANOVA) and significant differences were verified by the Tukey test (5%). Diets containing OL as the only lipid source (T3 and T6) provided better average weight (PM) and individual weight gain (GPI) in pacu juveniles. In addition, they provided higher (P &lt;0.05) levels of polyunsaturated fatty acids (PUFA) of the n-3 family in fillets, especially eicosapentaenoic acid (EPA, 20:5n-3). The only variable of the chemical composition of pacu juvenile fillets that presented a difference (P &lt;0.05) was the crude protein content, being higher in the fish fillets fed the diets without alpha-lipoic acid (T4, T5 and T6). The oils used in the experimental diets did not cause changes in the livers cells of pacu juveniles. It was concluded that sesamin, provided by sesame oil, did not promote changes in the growth performance of pacus, nor in the chemical composition and metabolism of polyunsaturated fatty acids (PUFA) of pacu juvenile fillets. The presence of alpha-lipoic acid did not affect the animals growth performance and its absence promoted higher levels of crude protein and polyunsaturated fatty acids in pacus fillets.