Over the last 50 years significant advancements have been made in the southern yellow pine (SYP) forests in the U.S. south. Due to silvicultural changes and large scale reforestation efforts the US south has seen significant increases in standing volume (more than 120% over the period). Landowners that grow SYP plantations largely manage for trees that are harvested to produce dimensional lumber. With the changes in growth patterns it is of interest if there have been any changes in structural properties of the lumber that is produced from timber grown today. Landowners desire confirmation that what they are doing in terms of management is maintaining the quality and strength of lumber that the market demands. This information is critical because timberland owners’ plant and manage trees that will ultimately be brought to market at lumber 25-40 years into the future. In an effort to provide clarity to this topic this dissertation investigates: 1) The extent to which the specific gravity (SG), bending strength (modulus of rupture, MOR), and bending stiffness (modulus of elasticity, MOE) of small clear specimens of SYP have changed, particularly with respect to reduction(s), during the interval from approximately 1965 to 2015. 2) The extent to which the compression parallel to grain and perpendicular to grain strength of small clear specimens of SYP have changed, particularly with respect to reduction(s), during the interval from approximately 1965 to 2015. Use statistical analysis of variance to investigate potential differences among data from a historical 1966 data set, a 2014 in-grade data set, and a 2018 staircase material data set. 3) The nature of the relationship between and among SG, MOE, and MOR of small clear specimens of SYP and how these relationships may have changed, during the interval from approximately 1965 to 2015. Use statistical regression analysis to explore changes to the interrelationships of SG, MOE, and MOR among the three samples, with particular interest toward how these may impact or influence non-destructive evaluation. This work consists of 3 independent chapters using varying appropriate statistical methods and is accompanied by an introduction and conclusion.

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The tensile resistance of No. 15 lap spliced reinforcing bars with varying transverse spacing and lap splice length was evaluated in full-scale concrete block wall splice specimens. The range of the transverse spacing between bars was limited to that which allowed the bars to remain within the same cell, and included the evaluation of tied spliced bars in contact. Two-and-a-half block wide by three course tall double pullout specimens reinforced with contact lap splices were initially used to determine the range of lap splice length values to be tested in the wall splice specimens such that bond failure of the reinforcement occurred. The double pullout specimens were tested in direct tension with six replicates per arrangement. Three values of lap splice length: 150, 200, and 250 mm, were selected from the testing of the double pullout specimens and tested in the wall splice specimens in combination with three values of transverse spacing: 0, 25, and 50 mm, with three replicates per configuration. A total of twenty-seven two-and-a-half block wide by thirteen course tall wall splice specimens reinforced with two lap splices were tested in four-point loading. Both the double pullout and the wall splice specimens were constructed in running bond with all cells fully grouted. The tensile resistance of the lap spliced bars in the double pullout specimens was measured directly. The contact lap splices with a 150, 200, and 250 mm lap splice length developed approximately 38, 35 and 29% of the theoretical yield load of the reinforcement, respectively. The difference between the mean tensile resistances of the three reinforcement configurations tested in the double pullout specimens was found to be statistically significant at the 95% confidence level. Different than expected, the tensile resistance of the lap spliced reinforcing bars in the double pullout specimens was inversely proportional to the lap splice length provided. For the short lap splice lengths used in this investigation, the linear but not proportional relationship between bond force and lap splice length known from reinforced concrete is believed to have caused this phenomenon. An iterative sectional analysis using moment-curvature response was used to calculate the tensile resistance of the lap spliced reinforcement in the wall splice specimens. The calculated mean tensile resistance of the reinforcement increased with increasing lap splice length, and was greater when the bars were in contact. Securing the bars in contact may have influenced the tensile capacity of the contact lap splices as higher stresses are likely to develop as a result of the bar ribs riding over each other with increasing slip. Results of the data analysis suggest that the tensile resistance of non-contact lap splices within the same cell is generally independent of the spacing between the bars. A comparison of the experimental results for the wall splice specimens with the development and splice length provisions in CSA S304.1-04 and TMS 402-11 indicate that both the Canadian and U.S. design standards are appropriate for both contact and non-contact lap splices located within the same cell given the limited test database included in this investigation.

A known method for the preservation of green foliage was adapted in order to preserve floral tissues, retaining the colour and texture, thereby providing a method suitable for the preservation of whole flowers. Initially, the effects of the existing foliage preservation process on floral tissues were studied and the resulting problems of limp sticky petals and colour loss were identified. Subsequently, with a knowledge of basic plant anatomy and of the properties of the main floral pigments, the anthocyanins, a series of experiments on petals and whole flowers were carried out in an attempt to rectify these problems and to incorporate the remedies into a method for preserving whole flowers. The problem of improving the texture and firmness of flower heads was tackled by investigating the effects of adding bulking or setting ingredients to the process fluid and establishing their optimum concentrations. In the case of flower colour, the addition of acid was required in order to maintain the bright anthocyanin colours and a range of acids was investigated. Furthermore, since it is known that in nature the anthocyanin pigments are stabilised by metal ions and copigments, the use of these agents in the preservation process was also considered. This empirical work was then validated by confirming the identity of the main pigments involved and by studying various aspects of the new preservation process. Factors examined included acid concentration, temperature, solvent composition and the addition of metal ions and copigments to solutions of petal extracts containing anthocyanin pigments. Physical changes resulting from processing, including process fluid content and the moisture absorption properties of processed petals were also measured. Finally, the application of a selection of coating materials was assessed in an attempt to increase the life span of the processed flowers by providing extra protection against environmental stresses.

Les superalliages monocristallins à base de nickel sont couramment utilisés dans la fabrication des aubes de turbines à gaz aéronautiques. En service, ces pièces mécaniques sont soumises à des sollicitations mécaniques et thermiques sévères. La composition chimique et la microstructure de ces superalliages monocristallins ont été optimisées à travers différentes générations d'alliages dans le but de résister au fluage à des températures supérieures à 1100°C. Pour protéger ces matériaux des agressions environnementales (oxydation isotherme et cyclique à très haute température, corrosion à moyenne et haute température), les aubes de turbine sont généralement revêtues d'une couche de NiAlPt ou de MCrAlY (M=Ni, Co). Le procédé de dépôt et les traitements thermomécaniques entrainent la formation d'une zone d'interdiffusion entre le revêtement et le substrat. De plus, la microstructure des différentes zones (le superalliage, le revêtement et la zone d'interdiffusion) évolue en service du fait de l'effet combiné des sollicitations mécaniques et thermiques. De telles évolutions sont susceptibles d'affecter localement les propriétés mécaniques des aubes de turbine. Les revêtements MCrAlY ont fait l'objet de nombreuses études portant sur l'oxydation et la corrosion à haute température. L'abattement des propriétés mécaniques du superalliage du fait de la présence du revêtement a été largement étudié sur le système complet, c'est à dire le superalliage revêtu. Ces études ont eu pour but d'estimer une épaisseur de superalliage qui soit considérée comme non porteuse de la charge, et ce indépendamment de la taille de la zone d'interdiffusion. L'affinement des modèles prédictifs de comportement mécanique et de durée de vie des matériaux requiert une base de données relative aux propriétés locales et à leur évolution au cours du vieillissement. Ces données n'étaient pas disponibles jusqu'à ce jour. Ce travail a donc porté sur la caractérisation microstructurale et mécanique de la zone d'interdiffusion du système MC2 revêtu de NiCoCrAlYTa par co-déposition électrolytique. Des éprouvettes de traction ont été extraites des différentes zones de ce système à gradient de propriétés à l'état de réception et aussi dans des états vieillis avec ou sans contrainte appliquée. Elles ont été ensuite testées mécaniquement à haute température dans des conditions environnementales optimisées de façon à limiter les effets induits par l'oxydation sur le comportement mécanique d'éprouvettes aussi minces. Ces échantillons de 20 à 400 μm d'épaisseur ont été obtenus en utilisant une machine de rodage afin de limiter l'impact de la méthode d'usinage sur l'état de contrainte résiduel. Deux bancs d'essais mécaniques ont spécialement été développés dans le cadre de cette étude pour réaliser des essais de fluage et de traction sur ces échantillons ultra-minces sous atmosphère contrôlée jusqu'à 1200°C. Les résultats obtenus sur ces échantillons minces ont été comparés aux résultats d'essais conduits sur des éprouvettes massives. L'effet « paroi mince » a été exploré parallèlement afin de statuer sur la possibilité d'utiliser ces données pour décrire le gradient de comportement du système. / Monocrystalline nickel based superalloys are the most suitable materials for the design of high performance turbine blades. In service, these mechanical parts undergo both harsh mechanical and thermal solicitations. The chemical composition and also microstructure of these superalloys have been optimized through different generations to resist creep deformation at temperature higher than 1373K. To protect these materials from environment stresses (isothermal and cyclic oxidation at high temperature, intermediate temperature corrosion) blades are generally coated with a NiAlPt or MCrAlY layer (M=Ni, Co). Both deposition process and thermomechanical treatment generate an interdiffusion zone (IDZ) between the coating and the substrate. Moreover, the microstructure of the different strata (superalloy, coating and interdiffusion zone) evolve in service due to the combine effect of high temperature and stress. Such evolutions may locally affect the mechanical properties of turbine blades. MCrAlY coatings have been studied extensively from an oxidation and hot corrosion point of view. The drop of mechanical properties of superalloys because of the presence of coating has been investigated on full system, so that to say the coated superalloy. These study aims to estimate a none bearing thickness of the superalloy independently from the size of the interdiffusion zone. Refinement of predictive models on mechanical behaviour and lifetime of materials require data relative to local properties and their evolution when ageing. These data were not available until now. Hence, this work deals with microstructural and mechanical characterisation of the interdiffusion zone of the system MC2 coated with NiCoCrAlYTa by electrochemical codeposition. Tensile specimens were extracted from the different zones of this functionally graded material on “as received” state and after ageing with and without applied stress. Then, these specimens were mechanically tested at high temperature in optimised controlled atmosphere in order to prevent ultrathin specimens from oxidation effects on the mechanical behaviour. These specimens in a range of 20 to 400μm thick were obtained by use of a lapping machine in order to limit the impact of gritting on residual stress. Two mechanical test rigs were especially designed for this study to perform creep and tensile testing on these ultrathin specimens under controlled atmosphere at temperature up to 1473K. Results obtained from these ultrathin specimens were compared with testing conducted on bulk materials. The “size effect” was explored in parallel so that to conclude on the feasibility of using these data to quantify the behaviour gradient of this system.

As a result of the quick rise of pXRF technology in archaeology, there are concerns regarding the reliability and validity of data output acquired from pXRF. In this study, I test the hypothesis that portable X-ray fluorescence (pXRF) spectrometry can provide reliable and valid results, using newly developed calibration curves, for the analysis of archaeological animal and human skeletal materials in prehistoric Peru to address hypotheses about ancient diet and trade. While pXRF systems may come with calibration software, the few if any standards and reference materials provided with the instrument rarely correspond to the vast array of archaeological materials capable of being analyzed by pXRF, including archaeological bone specimens. Empirical calibration curves for Ba, Ca, Fe, and Sr were created using the linear regression analysis of 19 human and animal bone standards analyzed via pXRF and ICP-MS. The results suggest the calibrations for Ca and Sr are sound, but the calibrations for Ba and Fe need to be further improved. In order to assess the reliability of pXRF (i.e. precision and accuracy), statistical analyses of 60 measurements on human bone specimens as well as on 19 human and animal bone specimens was performed in this study. The results indicate that the precision of pXRF is reliable, but additional work is needed with regard to accuracy. In contrast, the analysis of forty-four prehistoric human and animal bone specimens from varying regions in Peru were used to test the validity of pXRF. The pXRF data support the notion that pXRF is a valid technique to use in the analysis of bone specimens to address archaeological questions regarding paleodiet and possible trade interactions among individuals that reside in the highland and coastal valley regions of Peru

The aim of this work was to evaluate international trade with Manis. spp. according to the CITES database during the period 2002-2013. Manis spp. was classified in appendix II CITES in 1995. In 2000 there was an unsuccesfull attempt to reclassified Manis spp. to appendix I CITES. In this year the zero quota was set for Asian pangolins for commercial purpose. A rapid increase of an illegal trade was noticed after the setting of zero quota. The most frequent trade with pangolins was in these forms: 1) derivatives, 2) specimens, 3) scales, 4) live pangolins and 5) skins. Asian pangolins´ species were traded mostly in forms of derivatives, specimens, scales and skins in the period 2002-2013. M. javanica and M. pentadactyla with medium and large distribution area were quantitatively the most traded species, respectively. Main importers of Asian forms of pangolins were: USA (derivatives and specimens), China (scales in kg) and Indonesia (scales in pieces) and Mexico (skins). The African pangolin M. tricuspis was the third most frequent species in the international trade and was traded especially in form of live pangolins. M. tricuspis lives in one of the largest distribution area. Main importer of live pangolins was Italy. Breeding pangolins in captivity is due to the specific feeding requirements demanding. There are about 46 individuals of pangolins in Zoos all over the world, whereas in Europe there are only 2 pangolins in the Leipzig Zoo.

O aumento de demanda por combustíveis menos poluentes e de fontes renováveis faz com que o Etanol se destaque como uma alternativa as fontes convencionais de energia. O crescente aumento no consumo deste produto, para os próximos anos, exigirá meios de transporte e estocagem eficientes e seguros, desde os diversos produtores até os terminais de distribuição. O transporte por dutos é, sem dúvida, a forma mais econômica de transporte deste produto, porém, há evidências de que esses dutos de transporte e fundo de tanques de armazenamento de etanol poderiam ser susceptíveis ao fenômeno de corrosão sob tensão. Este fenômeno pode ser avaliado, por exemplo, por ensaios de baixa taxa de deformação (BTD) com corpos de prova com ou sem entalhe. Este trabalho tem por objetivo avaliar a influência da severidade do entalhe em corpos de prova ensaiados a baixa taxa de deformação no meio etanol combustível simulado (PRCI SFGE). Foram preparados quatro tipos de corpos de prova de aço API X70: sem entalhe, com entalhe da norma NACE TM 0111, com entalhe “intermediário” (severidade 18,9% menor que o da norma) e com entalhe “menos severo” (redução de 37,2% na severidade do entalhe, segundo concentração de tensões, quando comparado com o da norma). Os resultados mostram que os quatro tipos de corpos de prova apresentaram susceptibilidade ao meio (etanol PRCI SFGE). Nos corpos de prova sem entalhe esta susceptibilidade foi evidenciada somente nas imagens fractográficas. Já nos CPs com entalhe, mesmo com redução de concentrações de tensões no entalhe, observou-se resultados bem semelhantes, ficando evidenciada a susceptibilidade ao meio tanto nas imagens fractográficas (fratura frágil), quanto pela diminuição da ductilidade. / The increasing demand for cleaner fuels and renewable sources makes the ethanol rise as an alternative to conventional energy sources. The increasing consumption rate of this product, predicted for the upcoming years, will require safer and more efficient methods for transportation and storage through the entire transport cycle. Pipelines are the most economical way to transport it. However, there is evidence that pipeline transportation and the bottom of the storage tanks for ethanol might be susceptible to the stress corrosion cracking phenomenon. This phenomenon can be assessed by slow strain rate tests (SSRT) using smooth or notched specimen. This work aims to evaluate the influence of notch severity in specimens submitted to SSRT technique in simulated fuelgrade ethanol (PRCI SFGE). Four types of specimens of steel API X70 were prepared: unnotched, notched according to standard NACE TM 0111, notched with “intermediate” severity (severity 18.9% lower than the standard) and “less severe” notched (reduction of 37.2% on severity of the notched when compared with the standard). The results show that both sample types presented susceptibility in the solution (ethanol PRCI SFGE). For the unnotched specimens this susceptibility was observed only in fractographic images. In the notched specimens, despite the reduction of stress concentrations in the notch, the results were very similar. In this case the susceptibility can be observed in fractographic images (brittle fracture) as well as by decrease in the ductility.

Made available in DSpace on 2014-06-11T19:25:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2007-08-31Bitstream added on 2014-06-13T18:53:17Z : No. of bitstreams: 1 silva_af_me_ilha.pdf: 782444 bytes, checksum: 8a5261574387fc8eefd6cb7f482c662d (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Atualmente, a construção em alvenaria estrutural toma como base para determinação da resistência das paredes, a resistência de corpos-de-prova prismáticos, constituídos por dois blocos. Este tipo de ensaio é especificado por norma, mas apresenta problemas já bastante conhecidos, como a alteração do valor de sua resistência devido ao confinamento causado pelos pratos da prensa. Esta mesma norma também especifica o ensaio de paredes em tamanho real, que são tão onerosos e de difícil execução, que são poucos os laboratórios capazes de realizá-los. Para complementar as indicações feitas pela norma brasileiras, os laboratórios de pesquisa utilizam outros tipos de corpo-de-prova, como o prisma de três blocos, que atende às necessidades de praticidade sem apresentar a inconveniência da alteração no valor de sua resistência devido ao confinamento pelos pratos da prensa. Mas este corpo-de-prova ainda está longe de representar fielmente a alvenaria final, sendo sua resistência maior que a da parede. Com o presente trabalho deseja-se investigar, de forma ampla, a resistência à compressão e a deformação da alvenaria estrutural de blocos de concreto, utilizando-se de diferentes tipos de corpos-de-prova, compostos por blocos e argamassas de diferentes resistências. Foram utilizados dois tipos de blocos e quatro tipos de argamassas. Estas últimas podem ser divididas, segundo à sua origem, em mistas e industrializadas. Para analisar a influência do tipo de argamassa, foi definido que uma das argamassas industrializadas tivesse resistência próxima a de uma das mistas. Os corpos-de-prova utilizados foram: prisma de dois blocos, prisma de três blocos, painel de (45x60) cm, painel de (90x100) cm e parede de (90x240) cm. Portanto, foram realizadas várias séries de ensaio, com a combinação dos três fatores condicionantes: geometria do corpo-de-prova, resistência... / Currently, the strength of the structural masonry is based on the strength of prismatic specimens, built by two blocks. This type of test is specified by a Brazilian standard, but it presents some problems, such as the alteration of its strength value due to the confinement caused by the machine plates. The same standard also specifies the test of walls in real size, but they are too expensive and its execution is very difficult, so few laboratories are able to carry them out. Trying to attenuate such reality, research centers use other types of specimens, such as the prism of three blocks, which is easy to build and doesn’t present the inconvenience of the alteration of its strength value due to the confinement caused by the machine plates. But this kind of specimen is still far from representing, satisfactorily, the masonry: its strength is quite bigger than the masonry one. In this context, the present work aim to investigate, widely, the compressive strength and the deformation of the concrete structural masonry, using different types of specimens, built by blocks and mortars with different strengths. Two types of blocks and four types of mortars were used. These last ones can be divided, according to its origin, in mixing and industrialized. In order to analyze the influence of the type of mortar, it was defined that the strength of one of the industrialized mortar had to be next to one of the mixing. The specimens used were: prism of two blocks, prism of three blocks, panel of (45x60) cm, panel of (90x100) cm and wall of (90x240) cm. Therefore, many series of tests were carried out, with the combination of the three factors: type of specimen, block strength and mortar strength. The results were compared with values found in literature in order to conclude new trends or to reaffirm old theories about the efficiency interval of concrete structural masonry. The deformation was... (Complete abstract click electronic access below)

Made available in DSpace on 2014-10-09T12:55:40Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:05:05Z (GMT). No. of bitstreams: 0 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Dissertação (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP / FAPESP:06/58555-4