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Orientador: Ivaldo de Domenico valarelli / Coorientador: Eduardo Carlos Bianchi / Banca: Marcos Tadeu Tiburcio Gonçalves / Banca: Manoel Cléber de Sampaio Alves / Resumo: O lixamento é um dos métodos de preparação de superfície mais comum nas indústrias moveleiras, que precede o processo de acabamento. O objetivo do lixamento é produzir superfícies livres de defeitos visíveis como também deixar a superfície uniforme. Este trabalho foi realizado com o objetivo de avaliar as propriedades físico-mecânicas e analisar a influência da granulometria das lixas no lixamento plano, sobre o acabamento superficial de chapas de partículas de bambu, quanto nos esforços no lixamento de força e potência de lixamento. As amostras foram confeccionadas especificamente para este estudo, teve na sua composição o adesivo uréia formaldeído em diferentes quantidades, sendo elas: 8,10,12 e 15%. no ensaio de lixamento, utilizou-se uma velocidade de avanço de 12 m/min e três granulometrias de lixas: 80,100 e 120. Uma central de aquisição de dados foi usada para a captação das variáveis: potência de corte, emissão acústica e vibração, em tempo real. A rugosidade das amostras foi medida por um rugosímetro após o lixamento. De acordo com os resultados dos ensaios físico-mecânico, as partículas de bambu utilizados de chapas de partículas aglomeradas, com adesivo convencional uréia-formaldeído, obtiveram comportamento aceitável em relação ao exigido pelas normas técnicas brasileiras, para maioria dos ensaios, isso indica bambu como uma alternativa tecnicamente viável para o emprego em chapas aglomeradas, desde que respeitadas as suas características de resistência. Para o ensaio de lixamento, a lixa P80 apresentou significância para o sinal de emissão acústica, podendo ser aplicado na produção industrial. Já na variação da quantidade de adesivo, o traço de 12% foi o que apresentou melhores resultados, tanto no melhor acabamento superficial, quanto na força de corte. Em ambos, os resultados médios foram significativos. Podendo ser utilizados na produção de chapas aglomeradas que exijam / Abstract: The sanding is a surface preparation methods common in the furniture industry, preceding the finishing process. The purpose of sanding is to produce surfaces free of visible defects but also leave the surface uniform. This study was to evaluate the physical and mechanical properties and to analyze the influence of the particle size of the plane grinding sandpaper on the surface finish of sheet bamboo particleboard, as in sanding efforts on strength and power sanding. The samples were prepared specifically for this study, had constituted the urea formaldehyde adhesive in different amounts, as follows: 8,10,12 and 15%. in the grinding test, we used a feed rate of 12 m/min and three particle sizes sandpaper: 80,100 and 120. A central data acquisition was used to capture the variables: cutting power, acoustic emission and vibration in real time. The roughness of the samples was measured by a profilometer after sanding. According to the results of physicomechanical particleboard used in the manufacturing of bamboo sheets of particleboard with conventional urea-formaldehyde adhesive, achieved acceptable performance in relation to that required by technical standards in Brazil, for most tests, it indicates bamboo as an alternative technically feasible for use in particlaboard, in compliance with the strength characteristics. To test the sanding, the sandpaper P80 showed significance for the acoustic emission signal and can be applied in industrial production. Already on varying the amount of adhesive, the trace of 12% showed the best result in both better surface finish , as the cutting force. In both, the average results were significant. May be used in the production of particleaboard that requier good surface finish and lower cutting force / Mestre

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A preocupação mundial em relação aos impactos ambientais e seus reflexos positivos ou negativos na natureza têm mobilizado diversos setores da indústria. O processo de fabricação da viscose quando não controlado é altamente poluidor, causando impactos ao meio ambiente. Portanto, a escolha da sua matéria-prima pode amenizar esses problemas. O objetivo deste trabalho é analisar comparativamente os tecidos de malha fabricados com fibras de viscose convencional eucalipto e outras - com fibras de viscose obtidas a partir do bambu. Para a análise foram escolhidas as seguintes matérias-primas: fios 100% viscose convencional (fiação de anéis e jato de ar) e fios 100% viscose de bambu (fiação de anéis) e fabricadas malhas com gramaturas médias estatisticamente iguais. Os tecidos foram beneficiados e realizados os ensaios de gramatura, tendência à formação de pilling e resistência à solidez à água. Os resultados experimentais mostraram que não existem diferenças significativas entre as características estudadas. / The global concern regarding the environmental impacts has assembled several industry sectors. This study has as a goal to analyze relatively two types of mesh fabrics: viscose, which can be produced through cellulose regeneration obtained by bamboo or from other trees or plants, and thus, it can be chosen one or the other within a sustainable development context. This manufacturing process of viscose is highly pollutant, provoking negative impacts to the environment. Therefore, the choice of raw material might reduce these issues relating to sustainability. This comparison also has an objective to open a space for discussions regarding to sustainability concept in textile sector, which many studies are limited to analyze the results comparing materials only, not considering the process as a whole, from the choice of raw material, obtention, cultivation, transformation, to the final product, including the lifecycle, the durability and disposal of a fashion product. The experimental results showed that no significant differences between the characteristics studied.

Dans cette étude, les matériaux composites poly 3-hydroxybutyrate-co-4-hydroxybutyrate (P34HB) / fibres de bambou et polybutylène succinate (PBS) / fibres de bambou ont été préparés en utilisant le mélangeur interne et le moulage par compression. Les propriétés thermo-mécaniques de P34HB et de PBS ont été caractérisées. Les fibres de bambou ont été modifiées par des traitements chimiques. Les propriétés mécaniques telles que la résistance à la traction, la résistance à la flexion, le module d’élasticité et les propriétés thermiques ont été étudiées. Pour les deux types de composites (P34HB et PBS), le module est significativement amélioré, cependant, la résistance du composite est légèrement diminuée. L'allongement à la rupture est plus faible que celui des polymères purs, ce qui indiquerait une bonne adhérence entre la matrice et les fibres. L'étude révèle que l'adhésion est améliorée avec les fibres modifiées avec le silane et l'acide acétique, ce qui entraîne une augmentation des propriétés mécaniques du matériau, par rapport à celles des composites renforcés avec des fibres non traitées. En outre, le taux de 20% de fibres est considéré comme la bonne composition de fibres pour garantir de bonnes propriétés thermo-mécaniques et une absorption d'eau faible.En étudiant ces matériaux composites, nous visons à produire des matériaux respectueux de l'environnement. De plus, l’abondance des fibres de bambou permettra de réduire le coût de la matière première. Ce travail porte principalement sur la modification des fibres de bambou afin d'améliorer les propriétés globales des composites et sur la comparaison de ces propriétés par rapport à celles des fibres non traitées. Pour atteindre une meilleure adhérence matrice-fibre, un agent de couplage et/ou compatibilisant peuvent être étudiés et utilisés dans une future étude. / In this study, poly 3,4 hydroxy butyrate (P34HB)/bamboo fibers and polybutylene succinate (PBS)/bamboo fibers composites were prepared by internal mixer and compression molding. P34HB and PBS were characterized with mechanical and thermal methods while bamboo fibers were modified with chemical treatments. Mechanical properties such as tensile strength, flexural strength, modulus and thermal properties were investigated. For both 2 kinds of composites (from P34HB and PBS), it was found that the modulus was significantly improved, however, the strength of the composite was slightly decreased and the elongation at break was a lower than the neat polymer suggesting that the adhesion between matrix and reinforcement should be improved more. The study reveals that modifying the fibers with both silane and acetic acid would improve the adhesion, resulting to the better mechanical properties of the material, compared with composites reinforced with untreated fiber or fiber treated with other methods. Also, 20 % of fiber content is regarded as the good composition of fiber to guarantee the good mechanical, water absorption and thermal properties.By taking advantage of P34HB, PBS and bamboo fibers, we aim to produce the material which is environmental friendly. Moreover, the abundant bamboo fibers can be used and these bamboo fibers will reduce the cost of the material. Within this work, we focus on the modification of bamboo fibers to reach our goal of improving the overall properties of the composites, compared with composites reinforced with untreated fibers. To achieve the better adhesion between fibers and matrix, coupling agent and compatibilizer may be used and studied in our future study.

Economic benefits obtained from Flagellaria guineensis, a climbing bamboo, by local people received attention in previous studies but little is known about its regeneration ecology in three different forest stand conditions, i.e. forest edges, forest gaps and mature closed-canopy stands. In the Eastern Cape of South Africa the species grows in the Transkei Coastal Forests. The main aim of this study was to assess the regeneration ecology of F. guineensis in those forests. The specific objectives were to describe the phenological state that would influence the flowering, fruiting and growth of the species, and to compare the culm (stem) development from the rhizome between the different forest stand conditions. Phenological comparison was done in forest edge and forest interior conditions two forests. Rating scales were applied to determine the phenological states of the presence and amount of flower buds, open flowers, fruits, shoots and seedlings. Development of F. guineensis was assessed by sampling clusters in the three different forest stand conditions in three forests. The observation made in two Transkei Coastal Forests indicate that F. guineensis regenerates by producing seed, new vegetative shoots from rootstocks and also shoots at the growing tips. The flowering and fruiting period occurred only in the rainy season in Mtambalala forest but both rainy and dry seasons in Bulolo forest. More flowers and fruits of F. guineensis were found in Bulolo forest and in the forest edge (where F. guineensis is able to form tangles on the canopy of its host tree) respectively. This climbing bamboo clings on any plant around it for support and forms tangles on the canopy of its host in forest edges with no direct damage caused to host trees. The production of seedlings, shoots from the rhizome and shoots at the growing tips was constant during the study period in both study sites. The growth pattern of F. guineensis was different when comparing the three Transkei Coastal Forests studied. Manubi forest was found to have clusters and culms with the highest diameters and length compared to Mtambalala and Mnenga forests. There was a significant difference in culm diameter and length of F. guineensis between all three forests, whereas cluster diameter and number of culms per cluster were not influenced by forest stand conditions. F. guineensis clusters were common in the forest edges or gaps, and formed tangles in the canopy of their host trees. The described pattern of growth of F. guineensis contributes to recovery of the forest edges or gaps by restricting easy movement in and out of the forests. Several recommendations were made for harvesting of culms for basketmaking, such as: it should be done with care to reduce tangles in the forest and tree canopies; it must take place during the dry season, when the culms in a cluster are not flowering or fruiting; and studies are needed on the growth rate of seedlings and their growth into the forest canopy and how the bamboo can be cultivated outside the forest for better production of culms. / Dissertation (MSc)--University of Pretoria, 2017. / SAFCOL / Microbiology and Plant Pathology / MSc / Unrestricted

Today’s environmental concerns have led a renewed search in industry to find new sustainable materials to replace non-renewable resources. President Barack Obama also quoted in the recent 2012 Presidential Debate “that there is a need to build the energy sources of the future and invest in solar, wind, and bio-fuels.” Bio-composites are believed to be the future and the new substitute for non-renewable resources. Bio-composites are similar to composites in that they are made up of two constituent materials; however the main difference is that bio-composites are made from natural fibers and a biopolymer matrix. This research investigates the buckling behavior of bamboo and will analyze and determine the slender ratio that will induce buckling when bamboo is used as a column. Along with the investigation of the bamboo under buckling, this study will also show the potential of bio-composites to replace non-renewable resources in industry through experimental and numerical analysis. However, in order to study the buckling behavior of the bamboo, the mechanical characteristics of the bamboo and optimal curing treatment first had to be established. This is because, in order for bamboo to acquire proper strength characteristics, the bamboo must first be treated. Due to the scarcity of bamboo material in the lab, the obtainment of the mechanical properties of the bamboo as well as the optimal curing treatment was done in collaboration with Jay Lopez. In order for bamboo to acquire proper strength characteristics, the bamboo must be treated. In the first study, a total of four different types of natural treatments were analyzed to optimize the mechanical characteristics of bamboo. To assess each curing method, tensile and compression tests were performed to obtain the mechanical properties. Due to each bamboo culm having different thicknesses and cross sections, the specific strength property is used to normalize the data and allow for easy comparison and assessing of each curing method equally. The specific strength parameter is defined as the ultimate stress divided by the density of the material. These curing treatments consisted of four thermo-treatments, three different percentages of salt treatments, one lime treatment, and one oil treatment. The thermo-treatments consisted of heating the bamboo internodes in an autoclave with no pressure at 150oF, 180°F, 200°F, and 220°F. The experimental results of the thermo-treatments determined that bamboo obtains higher mechanical properties as well as reduced weight when heated at higher temperatures. This is explained by the increasing bound water extracted from the bamboo material at higher temperatures. In addition to finding the optimal heat treatment, the internodes of bamboo were soaked in natural additives that included a 3%, 6%, and 9% Instant Ocean sea salt solution, a Bonide hydrated lime solution, and a Kirkland canola oil solution for approximately five days and then heat treated at the optimal temperature of 220°F. The experimental results showed that all of the different additives had a significant effect on the mechanical properties. After determining the mechanical properties of each curing method, the results were then analyzed through a trade study. The trade study parameters consisted of weight-drop of the material, the specific strength, and the ultimate stress for both compression and tension. Each parameter of the trade study is kept unbiased as the weighting of each parameter is set equal to each other. The results of the trade study indicated that the 3% salt solution was the optimal curing treatment, yielding a higher specific strength value for both compression and tension, along with a significantly lower weight-drop after curing. After we came up with the optimal treatment, the buckling behavior of bamboo was investigated. The buckling analysis was investigated to determine at what slenderness ratio the bamboo would buckle when used as a column. A total of seven cases were investigated using different lengths, that ranged from 1.5” to 10”. Through experimental results, it was determined that a slenderness ratio above approximately 34.7 would induce global buckling to the bamboo column. The last investigation of this study consisted of building a small prototype wall structure using bio-composites. The prototype wall structure was manufactured using a combination of bamboo and a bi-directional woven hemp fabric. The dimensions of the prototype were 15.13” long and 7.75” tall. The wall structure was tested under compression in the Aerospace Structures/Composites Lab and the Architectural Engineering Department’s high bay laboratory. The results of the experimental test on the wall showed great potential for bio-composites, as the structure withstood a force of 46,800 pounds. A numerical analysis technique was also employed through the finite element method using the Abaqus software. The purpose of the finite element method was to validate the experimental results by comparing the buckling behavior of the tests. The numerical analysis showed very good agreement with the experimental results.

Nature, as the major consideration of the Organic Architecture of Frank Lloyd Wright, has constantly been favored as a path for a pure soul to communicate with the spiritual. Inspired by Wright's Organic Architecture and Traditional Chinese Garden, this thesis celebrates the beauty of Nature in Pandapas Pond, Giles County, VA, where a "Water Garden" is created on the open space defined by its water. Formally, the whole garden complex takes the inspiration from lotus flowers floating on the water, which could be thought of as an "organic system of architecture." / Master of Architecture

A busca por produtos fabricados com matéria prima renovável e cuja transformação não cause impactos ambientais motivou a presente pesquisa que se refere à utilização do colmo de bambu como material lenhoso na fabricação de painéis estruturais, para uso na construção civil. O Bambu apresenta algumas vantagens em relação a outras matérias primas, pois além de ser renovável, como a madeira e crescer mesmo em área marginais, apresenta um crescimento tão rápido que permite sua utilização estrutural já a partir de 3 anos de idade. O presente trabalho foi desenvolvido com o objetivo de avaliar as propriedades físico-mecânicas de painéis à base de bambu da espécie Dendrocalamus giganteus e compará-los entre si. A variação radial dos feixes fibrovasculares dentro da parede do colmo motivou a obtenção de lâminas de duas posições consideradas anatomicamente discrepantes, próxima à epiderme e próxima à lacuna do centro do colmo. Os colmos foram processados mecanicamente de tal forma a produzirem-se lâminas externas e internas que foram coladas e prensadas, originando os painéis BLCe (Bambu laminado colado com lâminas externas) e BLCi (lâminas internas). Amostras foram retiradas desses compósitos e observadas no microscópio eletrônico de varredura (MEV) para avaliar variáveis da matéria prima e do processo de fabricação que influenciam na qualidade do painel, principalmente a adesão entre as lâminas constituintes. A resistência ao cisalhamento no plano de cola foi a propriedade mais crítica, dentre as estudadas na presente pesquisa, porque sendo baixa, influenciou negativamente no módulo de elasticidade e, mais intensamente ainda, no módulo de ruptura, ambos na flexão estática. O inchamento, que se refere à variação da espessura do painel por absorção de água, foi considerado a propriedade desfavorável do painel de bambu, pois acumulou ao inchamento das lâminas individuais afastamentos indesejados que ocorreram as camadas constituintes do painel. / The search for products manufactured with renewable raw material which can be produced through an industrialization which does not cause environmental impacts led this research work to considerate the use of bamboo culm as woody material to manufacture structural panels that can be used as construction material. Bamboo presents some advantages over other materials, because beside of being renewable as wood is and growing even in poor sites, presents so fast growth that allows the culm to be used for structural purposes from 3 years old. This study was carried out to evaluate physical and mechanical properties of bamboo based panels produced with Dendrocalamus giganteus bamboo species and comparing themselves with each other. The radial variation of fibre vascular bundles inside the bamboo culm wall had motivated taking laminas from two different positions considered anatomically discrepant, next to the epidermis and by the culm center. The culms were mechanically processed in a way to produce external and internal laminas that were glued and pressed originating the GLBe (Glued Laminate Bamboo with external laminas) and GLBi (internal laminas) panels. Specimens were taken from the composites and observed in a Scanning Electron Microscope (SEM) to evaluate raw material variables and manufacturing process variables that influence the panel quality especially the adhesion between component laminas. The shear strength on glued surface was the critical property among those studied in this research, because being low did affect the modulus of elasticity and, even more intensively, the modulus of rupture both in bending test. Swelling that refers to panel thickness variation due to absorption of water, was considered the most unfavorable property of the panel because accrued to the individual laminas swelling the unexpected displacement that pull apart the panel component layers.

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