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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Resistência ao embutimento da madeira compensada / not available

Stamato, Guilherme Corrêa 15 April 1998 (has links)
A utilização da madeira compensada como componente de estruturas permanentes ainda é pouco difundida no Brasil, apesar de ser bastante utilizada em diversos países, onde tem se mostrado bastante eficiente como solução competitiva, segura e durável. O estudo do embutimento de pinos metálicos no compensado visa fornecer subsídios técnicos para o desenvolvimento desta tecnologia no país. Foram realizados ensaios de embutimento com os três diâmetros de prego e três de parafuso mais recomendados para estruturas de madeira, em oito chapas de madeira compensada, caracterizadas em ensaios especificados por normas brasileiras, avaliando a aplicação, para o compensado, do método de ensaio de embutimento em madeira maciça proposto pela NBR 7190/97, \"Projeto de estruturas de madeira\", concluindo que este é aplicável quando se utiliza espessuras comerciais do compensado como espessura do corpo de prova. Foram também realizados ensaios para análise dos efeitos da pré-furação no comportamento do compensado no embutimento. Um modelo numérico foi desenvolvido, utilizando o programa ANSYS v.5.2, para simular o comportamento do compensado no embutimento, encontrando resultados satisfatórios para elementos compostos por camadas e considerando comportamento elasto-plástico do compensado. Os resultados mostraram a viabilidade técnica da utilização do compensado em estruturas de madeira. / The use of plywood as a component of permanent structures is still not very diffused in Brazil, although it has been used in several countries, where it has been considered efficient as a competitive, safe and durable solution. The study of the embedment of steel dowels in plywood aims to supply parameters for the development of this technology in the country. Embedment tests were carried out with six different nail and bolt diameters recommended for timber structures, in eight types of plywood, characterized in tests specified by Brazilian norms. Such tests evaluated the application of the method of embedment tests in massive timber proposed by the Brazilian Association of Technical Norms (ABNT), NBR 7190/97, \"Design of timber structures\", concluding that it was applicable when the commercial thickness of plywood was used as thickness of the specimen. Tests were realized for the analysis of the pre-hole effects on the behavior of the plywood in the embedment. A numerical model was developed, using the ANSYS v.5.2 program, to simulate the behavior of the plywood in the embedment, finding satisfactory results for composed elements for layers and considering the elasto-plastic behavior of plywood. The results showed the technical viability of the use of plywood in the construction of timber structures.
42

Producer cooperatives and industrial democracy: a comparative study of the performance of cooperative and conventional plywood plants

Khodaparast, Youssef 01 January 1986 (has links)
Widely differing theoretical expectations exist concerning the economic performance of labor-managed firms or producer cooperatives (PCs). While a good number of theoretical studies of these firms by economists have been undertaken, there remain considerable gaps in the empirical record. This is especially true in the case of American PCs. In general, theoretical controversies have not been tempered by enough empirical analysis. While some expect good performance from PCs, others are much less sanguine. This study compares the economic performance of a group of eight worker-owned producer co-op plants with that of eight conventional mills in the Pacific Northwest softwood plywood industry. The purpose is to test the validity of several propositions that are typically maintained in the analysis of PCs suggesting that this type of organization basically lacks the incentive to utilize labor inputs efficiently, and is therefore less productive when compared to conventionally organized producing units. Using secondary data, pooled time-series cross-section equations are estimated. Results indicate that growth in annual output per employee per year is 18 percent greater in the co-ops than in their conventional counterparts. The study provides strong evidence that the two groups of plants differ significantly in their behavior. The major conclusion that emerges is that worker-owned co-ops are a viable and productive form of economic organization that utilize labor inputs efficiently and in doing so can achieve higher worker productivity than their conventional counterparts. In a public policy context, government support of employee ownership and establishment of worker-owned co-ops is viewed as a viable policy option to plant closings.
43

Oregon Modern in Bohmann Park: A Case Study of Northwest Mid-Century Architecture

Gordon, Samantha Marie 06 September 2018 (has links)
This thesis explores the Bohmann Park neighborhood of Washington County as a case study of contemporary style in Oregon. As both individual and the largest grouping of homes by Robert Rummer, Bohmann Park informs treatment of Rummer homes and contemporary resources. Nationally, contemporary homes by architects and builders have been recognized for their architectural and historic value through the historiography, National Register listing, and local protections. Modern architecture in Oregon has yet to be equally rigorously explored. Rummer’s prolific work is an ideal point of exploration. Within the context of architectural history and preservation practice, two condition assessments of individual residences in the neighborhood analyze the varied care and common threats faced by these resources. The adverse effects faced by Bohmann Park from the City of Portland’s Fanno Creek Pump Station and its mitigation efforts explore challenges faced by the subdivision as a potential historic district.
44

Resistência ao embutimento da madeira compensada / not available

Guilherme Corrêa Stamato 15 April 1998 (has links)
A utilização da madeira compensada como componente de estruturas permanentes ainda é pouco difundida no Brasil, apesar de ser bastante utilizada em diversos países, onde tem se mostrado bastante eficiente como solução competitiva, segura e durável. O estudo do embutimento de pinos metálicos no compensado visa fornecer subsídios técnicos para o desenvolvimento desta tecnologia no país. Foram realizados ensaios de embutimento com os três diâmetros de prego e três de parafuso mais recomendados para estruturas de madeira, em oito chapas de madeira compensada, caracterizadas em ensaios especificados por normas brasileiras, avaliando a aplicação, para o compensado, do método de ensaio de embutimento em madeira maciça proposto pela NBR 7190/97, \"Projeto de estruturas de madeira\", concluindo que este é aplicável quando se utiliza espessuras comerciais do compensado como espessura do corpo de prova. Foram também realizados ensaios para análise dos efeitos da pré-furação no comportamento do compensado no embutimento. Um modelo numérico foi desenvolvido, utilizando o programa ANSYS v.5.2, para simular o comportamento do compensado no embutimento, encontrando resultados satisfatórios para elementos compostos por camadas e considerando comportamento elasto-plástico do compensado. Os resultados mostraram a viabilidade técnica da utilização do compensado em estruturas de madeira. / The use of plywood as a component of permanent structures is still not very diffused in Brazil, although it has been used in several countries, where it has been considered efficient as a competitive, safe and durable solution. The study of the embedment of steel dowels in plywood aims to supply parameters for the development of this technology in the country. Embedment tests were carried out with six different nail and bolt diameters recommended for timber structures, in eight types of plywood, characterized in tests specified by Brazilian norms. Such tests evaluated the application of the method of embedment tests in massive timber proposed by the Brazilian Association of Technical Norms (ABNT), NBR 7190/97, \"Design of timber structures\", concluding that it was applicable when the commercial thickness of plywood was used as thickness of the specimen. Tests were realized for the analysis of the pre-hole effects on the behavior of the plywood in the embedment. A numerical model was developed, using the ANSYS v.5.2 program, to simulate the behavior of the plywood in the embedment, finding satisfactory results for composed elements for layers and considering the elasto-plastic behavior of plywood. The results showed the technical viability of the use of plywood in the construction of timber structures.
45

Potencial da madeira de clones do híbrido Eucalyptus grandis x Eucalyptus urophyla para a produção de lâminas e manufatura de painéis compensados. / Potential use of wood from Eucalyptus grandis x Eucalyptus urophylla hybrid clones for veneer and plywood production.

Renato Rocha Almeida 09 May 2002 (has links)
O presente estudo teve como objetivo principal avaliar o potencial da madeira de dois clones do híbrido Eucalyptus grandis x Eucalyptus urophylla para a produção de lâminas e manufatura de painéis compensados. Foram coletadas 5 árvores para cada clone (I e II) e duas toras de cada árvore, sendo uma da base (A) e outra subseqüente (B), totalizando 20 toras. As toras após descascamento e aquecimento em água quente foram processadas em torno laminador gerando lâminas de 2,00 mm de espessura nominal. O rendimento médio do processo de laminação foi de 51,74% para as toras do clone I e de 56,81% para as toras do clone II. A qualidade das lâminas produzidas foi avaliada com base na Norma de Controle de Qualidade e Classificação de Compensados, da ABNT. O clone I gerou lâminas de melhor qualidade: 11,94 % na classe A; 32,84 % na B; 54,48 % na C e 0,75 % na classe D, enquanto que o clone II gerou: 1,20 % na classe A; 8,40 % na B; 67,47 % na C e 22,89 % na classe D. Foram manufaturados compensados de 5 camadas, com lâminas da classe C para as capas e o miolo, coladas com adesivo à base de uréia-formaldeído. Os fatores de tratamento empregados na manufatura foram: clone (I e II), gramatura de cola (320 e 360 g/m2) e tempo de prensagem (8 e 12 minutos). O delineamento experimental foi inteiramente casualizado com arranjo fatorial do tipo 2 x 2 x 2. A partir dos compensados manufaturados foram obtidos corpos de prova para avaliação das propriedades físicas – massa específica aparente, absorção superficial de água, absorção total de água, inchamento mais recuperação em espessura e recuperação em espessura, e avaliação das propriedades mecânicas – flexão estática paralela e perpendicular (MOR e MOE) e resistência da linha de colagem ao esforço do cisalhamento nas condições seca e úmida. A análise estatística dos resultados das propriedades físicas e mecânicas foi realizada através de uma análise de variância. Não houve interação significativa entre os fatores clone, gramatura de cola e tempo de prensagem, considerando todas as variáveis avaliadas. Foram detectadas diferenças significativas para o fator clone em relação às variáveis massa específica aparente (maior para o clone I), absorção superficial e total de água (menores para o clone I); resistência da linha de colagem ao esforço do cisalhamento – condição seca e flexão estática – MOR paralelo e perpendicular (maiores para o clone I). Para o fator gramatura de cola não houve diferença significativa entre os tratamentos para nenhuma das variáveis avaliadas. Houve diferença significativa para o fator tempo de prensagem em relação às variáveis absorção superficial de água (menor para o tempo de prensagem de 12 minutos), inchamento mais recuperação em espessura e recuperação em espessura (menores para o tempo de prensagem de 8 minutos). A conclusão do trabalho é que as madeiras de ambos clones do híbrido Eucalyptus grandis x Eucalyptus urophylla apresentam alto potencial para produção de lâminas e manufatura de compensados. / The main objective of this work was to evaluate the potencial of eucalyptus grandis x Eucalyptus urophylla hybrid clones wood for plywood and veneer production. Five (5) trees were collected for each clone (I and II) and 2 logs of each tree, being one from base (A) and other subsequent one (B), totaling 20 logs. The logs after debarked and heated in hot water were processed in rotary cutting lathe generating veneers of 2,00 mm nominal thickness. The peeling yield was evaluated and mean values were 51,74% from clone I logs and 56,81% from the II one. The veneer quality graded was conduced following Norma de Controle de Qualidade e Classificação de Compensados, Brazilians standards. The clone I generated veneers of better quality: 11,94% of grade A veneer; 32,84% of B; 54,48% of C and 0,75% of grade D veneer, while the clone II generated: 1,20% of grade A veneer; 8,40% of B; 67,47% of C and 22,89% of grade D veneer. 5 layers plywood was manufactured with grade C veneers. The plywood manufacture treatment factors were: clone (I and II), glue amount (320 and 360 g/m2) and press time (8 and 12 minutes). From manufacture plywood were obtained specimens to evaluate the physical properties - apparent specific mass, superficial absorption of water, total absorption of water, thickness swelling more thickness recovery and thickness recovery, and the mechanical properties - parallel and perpendicular static bending (MOR and MOE) and bonding line shear test in the dry and wet conditions. The result obtained during the physical and mechanical assessments of plywood were analyzed using a variance analysis, executed by SAS (Statistical Analysis System). There was not significant interaction among the factors clone, glue amount and press time, considering all the appraised variables. Significant differences were detected for factor clone in relation to the variables apparent specific mass (clone I higher than clone II), superficial and total absorption of water (clone I smaller than clone II); bonding line shear test (dry condition) and static bending - parallel and perpendicular MOR (clone I higher than clone II). To the factor glue amount there was not significant difference among the treatments for none of the appraised variables. There was significant difference for the factor press time in relation to the variables superficial absorption of water (12 minutes smaller than 8 minutes), thickness swelling more thickness recovery and thickness recovery (8 minutes smaller than 12 minutes). It's concluded that Eucalyptus grandis x Eucalyptus urophylla hybrid clones wood have a high potencial for phywood and veneer production.
46

An investigation of residence design and construction involving plywood, new materials, and prefabrication

Kinzey, Bertram York January 1943 (has links)
no abstract provided by author / Master of Science
47

plywood work: setting up looms and other works of mischief

Rada, Nicholas S. 05 September 2007 (has links)
'after all, it takes a baker' / Master of Architecture
48

Factors influencing the production of Indonesian sawnwood and plywood

Siregar, Hezlisyah 17 December 2008 (has links)
The forest products industry of Indonesia grew rapidly after the establishment of the log export ban policy in May 1980. As a result, within about five years, Indonesia was transformed from the biggest exporter of tropical logs into a major exporter of processed wood products. To better understand this transition, this study presents multiple regression models of Indonesian sawnwood and plywood production and consumption based on time series data from 1970 to 1994. This study had three main objectives: 1) to create models that can be used for projecting future production of Indonesian sawnwood and plywood, 2) to identify the relationship and establish the degree of association between production and factors that influence their trends, and 3) to analyze Indonesian forestry policies of log export ban and sawnwood export tax as they affect production of sawnwood and plywood. Domestic sawnwood consumption was modeled as a function of population, log export policy (no log export ban vs. log export ban), and sawnwood tax policy (tax vs. no tax). Domestic plywood consumption was modeled as a function of population, consumer price index (CPI), and log export policy (ban vs. no ban). Export plywood consumption was modeled as function of exchange rate, log export policy, and sawnwood tax policy. The consumption and production of sawnwood and plywood were analyzed by multiple regression techniques. All parameters in the sawnwood and plywood equation were found to be significant. However, price did not influence the consumption or production of sawnwood and plywood significantly. All parameters in this study were found to be elastic. It is found that, during the period under investigation (using 1970 as the base year), the production and consumption of Indonesian sawnwood and plywood increased considerably. The projection of sawnwood and plywood productions for 5 years (1995-1999) also shows an increasing trend. / Master of Science
49

Ligações em estruturas de madeira compostas por chapas de madeira compensada / not available

Stamato, Guilherme Corrêa 06 May 2002 (has links)
As estruturas de madeira composta com alma em compensado já vem sendo amplamente utilizadas em diversos países onde as estruturas de madeira estão tecnologicamente mais desenvolvidas, oferecendo aos engenheiros civis mais uma opção de sistema construtivo eficiente, seguro e duradouro. Nesse trabalho são apresentados estudos teóricos e experimentais referentes às estruturas de madeira compostas utilizando compensado nas almas, e em especial as estruturas cuja ligação alma mesa é feita por pinos metálicos. O objetivo desse trabalho é desenvolver critérios de dimensionamento dessas estruturas para serem aplicados no Brasil. Vários critérios de dimensionamento de elementos compostos foram encontrados na bibliografia, alguns com simplificações que desconsideram efeitos de composição parcial e outros mais completos, que consideram deformações por cisalhamento, composição parcial etc. Com os resultados dos ensaios de vigas compostas pregadas foi possível comparar valores experimentais com resultados teóricos, concluiu-se que os critérios de dimensionamento do EUROCODE 5 são adequados. Os ensaios de rigidez de nó de pórtico de seção composta permitiram o desenvolvimento de metodologia para o cálculo da rigidez dessas ligações, visto que não existe formulação equivalente na bibliografia internacional. Concluiu-se que as ligações por pinos metálicos apresentam boa eficiência para serem utilizadas nas seções compostas com alma em compensado. As ligações de nó de pórtico com ligação alma/mesa pregadas podem ser consideradas rígidas na maioria dos casos estudados. / Plywood webbed structures have been applied in at several countries where timber structures are commonly used, giving civil engineers and builders one more option when looking for a safe, efficient and durable construction system. This work presents theoretical and experimental studies about plywood-webbed structures, with emphasis on nailed plywood webbed structures. The aim of this work is to develop design criteria for these structures to be used in Brazil. Several design criteria where found in the bibliography, some of them using simplifications for shear deflexions and joint deformations. Experimental results of nailed plywood webbed beams were compared with theoretical values from formulations found in the bibliography, concluding that EUROCODE 5 gives the best design criteria for nailed composite beams. Based on plywood webbed knee joints tests, a methodology to calculate the joint rigidity was proposed. The conclusions show the efficiency of this system and that nailed plywood webbed knee joints can be considered fixed for the majority of the specimens tested.
50

Ligações em estruturas de madeira compostas por chapas de madeira compensada / not available

Guilherme Corrêa Stamato 06 May 2002 (has links)
As estruturas de madeira composta com alma em compensado já vem sendo amplamente utilizadas em diversos países onde as estruturas de madeira estão tecnologicamente mais desenvolvidas, oferecendo aos engenheiros civis mais uma opção de sistema construtivo eficiente, seguro e duradouro. Nesse trabalho são apresentados estudos teóricos e experimentais referentes às estruturas de madeira compostas utilizando compensado nas almas, e em especial as estruturas cuja ligação alma mesa é feita por pinos metálicos. O objetivo desse trabalho é desenvolver critérios de dimensionamento dessas estruturas para serem aplicados no Brasil. Vários critérios de dimensionamento de elementos compostos foram encontrados na bibliografia, alguns com simplificações que desconsideram efeitos de composição parcial e outros mais completos, que consideram deformações por cisalhamento, composição parcial etc. Com os resultados dos ensaios de vigas compostas pregadas foi possível comparar valores experimentais com resultados teóricos, concluiu-se que os critérios de dimensionamento do EUROCODE 5 são adequados. Os ensaios de rigidez de nó de pórtico de seção composta permitiram o desenvolvimento de metodologia para o cálculo da rigidez dessas ligações, visto que não existe formulação equivalente na bibliografia internacional. Concluiu-se que as ligações por pinos metálicos apresentam boa eficiência para serem utilizadas nas seções compostas com alma em compensado. As ligações de nó de pórtico com ligação alma/mesa pregadas podem ser consideradas rígidas na maioria dos casos estudados. / Plywood webbed structures have been applied in at several countries where timber structures are commonly used, giving civil engineers and builders one more option when looking for a safe, efficient and durable construction system. This work presents theoretical and experimental studies about plywood-webbed structures, with emphasis on nailed plywood webbed structures. The aim of this work is to develop design criteria for these structures to be used in Brazil. Several design criteria where found in the bibliography, some of them using simplifications for shear deflexions and joint deformations. Experimental results of nailed plywood webbed beams were compared with theoretical values from formulations found in the bibliography, concluding that EUROCODE 5 gives the best design criteria for nailed composite beams. Based on plywood webbed knee joints tests, a methodology to calculate the joint rigidity was proposed. The conclusions show the efficiency of this system and that nailed plywood webbed knee joints can be considered fixed for the majority of the specimens tested.

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