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Estimating site productivity from non-site trees a site index based approach /Vopicka, Charles Edward. January 2007 (has links)
Thesis (M.S.)--University of Montana, 2007. / Title from title screen. Description based on contents viewed Aug. 13, 2007. Includes bibliographical references (p. 52-53).
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Composting of Cross Laminated Timber (CLT) SawdustBahsi-Kaya, Gulbahar 10 August 2018 (has links)
A three-month study evaluated composting of cross laminated timber (CLT) sawdust amended with 10% and 20% chicken litter. Moisture was provided by rainwater or deionized water depending on the precipitation. The contents in the containers were mixed once or twice a week for aeration. Samples were collected at 0, 45, and 90-day intervals to measure weight loss, moisture content, pH, compost maturity, microbial count, and carbon-to-nitrogen ratio. Results indicated that composted CLT with 20% chicken litter had much higher weight reduction than others at day 45 and 90. Treatments with 10% and 20% chicken litter had a higher initial pH than controls and showed a slow increase near to neutral 7 by day 90. The germination rate of radish seeds to measure the compost maturity showed that composted CLT with 20% chicken litter had significantly higher germination rate than the others at days 45 and 90. A greenhouse study of composted material showed also that the 20% treatment could be used as soil amendment due to its excellent C/N ratio but appears to be unsuitable for container media. Longer composting time is suggested for CLT sawdust to be cured and used for potting media.
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Evaluation of the durability of mass timber products against termites (Reticulitermes spp.) using choice testing.McGinnis, Jazmine A 01 May 2020 (has links)
Mass timber products are rapidly growing in fascination and popularity across the North American construction market, in which wood products are tested for durability and resiliency according to standards set by the American Wood Protection Association. Presently, the American Wood Protection Association (AWPA) E1 Standard calls for a test sample size of 2.54cm x 2.54cm x 0.64cm, which may be too small to encompass the large spacing between the bond lines of CLT, a multilayered mass timber product composed of layers of kiln-dried lumber alternating in grain direction. The objective of this study was to evaluate the resistance of untreated CLT against subterranean termites (Reticulitermes spp.) found in the southeastern United States using two-sample choice testing and extend the AWPA E1-17 Standard to accommodate the larger building material. Choice-testing methods were evaluated over a 4-week period for mass loss, visual rating, mold formation, and termite mortality.
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Watershed-scale sediment movement in relation to in-stream water quality:pre- and post-harvest observationsHamiter, Bonnie Leigh 02 May 2009 (has links)
Sediment is a leading contributor to nonpoint source (NPS) pollution in streams and rivers. Sources and sinks of sediment movement were identified for a 121-hectare watershed located in Webster County, Mississippi in order to evaluate the impact of forest harvesting on water quality and sedimentation rates. In a completely randomized design containing three replications of two treatments (unharvested vs. harvested) and two slopes (≤9% vs. >9%), twelve sub-watersheds were randomly selected for intensive measurement of the sources and sinks of sediment after precipitation events. In-stream, bank and forest road sediment movement were also monitored pre- and post-harvest. Total suspended sediment (TSS) in runoff from forest roads ranged from 36-188 g/L with a consistent trend of decreasing sediment concentrations with increasing distance from the road. Within the watershed, erosional processes dominated however there was little net change in soil elevation one year post-harvest.
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The Spirit of BuildingWolf, Collin Benjamin 17 July 2020 (has links)
What can be learned about design through the process of building?
The intent of this thesis is to learn about building; to gain a true understanding of the way design decisions are realized through built components. If by knowing what is to come in a project's future, does the designer change their way of working? A disconnect exists between imagined and realized design. As an idea moves closer to reality, much of its' initial spirit can be lost in translation.
This thesis was conceived as a design-build project, in an attempt to answer these questions. The intent was to consider a small-scale, built addition to an existing structure with a program simply focused on providing a place to vew from. By limiting the scope of building to a simple structure, it inherently forces a complete understanding of the nature of its connection.
Through this consideration, one also must consider the limitations of assembling the work; that is, what are one or two people capable of making? The limits of solidarity result in a design that requires modularity; something that is able to be broken down into small, manageable pieceswhich are assembled to produce a whole. Therein lies both the challenge and the value of this thesis, as well as the lessons learned in building architecture. / Master of Architecture / What can be learned about design through the process of building?
The aim of this Thesis was to take fundamental theoretical knowledge about building, acquired through my architectural education, and apply it through building a small structure.
A freestanding concrete staircase, located at a research facility on Virginia Tech's campus, was chosen for the structure's site. The intent was to add an additional set of stairs to it, allowing visitors to reach a higher viewing point to look out over the hills of Blacksburg.
The project was conceived as something small enough to be built quickly and with few people. By using primarily wood and simple hardware store materials, the project would be easy to work on and relatively inexpensive.
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Impacts of Land and Ownership Characteristics on the Stumpage Prices for Virginia's Nonindustrial ForestsHensyl, Curtis Hamilton 20 April 2005 (has links)
The character of Virginia's nonindustrial private forests is changing primarily for two reasons. First, many large, continuous forested tracts are being sub-divided, into with the resulting smaller tracts purchased for amenity values and recreation instead of as a timber investment (Hodge 1993). Second, the demographics of non-industrial private forest (NIPF) landowners are shifting away from an agricultural, rural focus to an urban oriented lifestyle and absentee ownership. These changes may mean less timber available for purchase by the forest industry. Timber that is sold will be on smaller parcels that is bound to have an impact on the procurement activities of forest industries. However, little research has been performed on the impacts of site and landowner characteristic on stumpage prices.
The objective of this research project is to identify how the stumpage price of timber is altered by the characteristics associated with the changing forest: decreasing tract size, decreasing harvested volumes, landowner residence, and landowner harvesting preferences. In addition to the price of timber, the competitiveness of timber sales is analyzed to determine what impact the fragmented forest could have on the competitiveness of timber markets.
To perform the study, site and landowner information was collected for 138 recent NIPF timber sales that occurred within central Virginia. This region is identified as a critical area for the study of forestry activities because of the growing urban and suburban residential populations and the large amount of forest industry activities taking place there.
Results show that access to the site is the most important characteristic determining the selling price of timber. Sites that are easy for logging crews and vehicles to approach dramatically increase the price paid per ton. Tract size is less important in determining bid prices for timber either once the total volume harvested passes a minimum of 500 tons, or there is mature hardwood sawtimber on the site and the acreage is greater than 50 acres. Landowners preference for select cut harvests results in a lower price per ton being paid by the purchaser due to the increased logging costs associated with this type of harvesting. / Master of Science
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Post-tensioned Timber Frames with Supplemental Damping DevicesSmith, Tobias January 2014 (has links)
In recent years the public expectation of what is acceptable in seismic resisting construction has changed significantly. Engineers today live under demands which are far more intensive than their historical counterparts and recent seismic events have shown that preserving life is no longer sufficient, and a preservation of livelihood is now the minimum. This means that after a major seismic event a building should not only be intact but be usable with no or minimal post-quake intervention. In addition to this already high expectation these demands must be met in a green and sustainable fashion with minimal (or even negative) environmental impact. This doctoral project looks to further advance the research into a new and innovative method of timber construction which satisfies (and exceeds) these demands.
In response to these higher expectations recent developments in the field of seismic design have led to the development of damage control design philosophies and innovative seismic resistant systems. Jointed ductile connections for precast concrete structures have been implemented and successfully validated. One of these systems, referred to as the hybrid system, combines the use of unbonded post-tensioned tendons with grouted longitudinal mild steel bars or any other form of dissipation reinforcing device. During the controlled rocking of the system under seismic loading the post-tensioning provides desirable recentering properties, while the devices allow adequate energy dissipation from the system as well as increased moment resistance at column bases and beam-column connections.
The hybrid concept is material independent and in 2004 an extensive campaign was begun to investigate the performance of the hybrid system when applied to large engineered timber members. Numerous small and large scale tests on both subassemblies and full buildings were performed showing that post-tensioned timber meets the seismic resilience demands now imposed by society. Recently this technology has also been applied in practice with over ten structures now using post-tensioned timber walls or frames, or a combination of the two, in New Zealand.
In-spite of the extensive research effort and the acceptance and adoption in practice of post-tensioned timber as a structural system, significant work was still required in the review and refinement of both the system itself and the analytical and numerical methods used to predict and analyse structural performance. The objectives of this research were to review and refine comprehension of the static and dynamic response, analytical and numerical modelling, and design of post-tensioned timber frames under lateral loading. In order to do this a three phase experimental testing campaign was devised and performed including quasi-static testing of an angle dissipative reinforcing device, quasi-static testing of a full-scale beam-column joint and the mono-directional dynamic testing of a 2/3rd scale three storey frame. All testing used glue laminated timber, which had not been previously used in post-tensioned timber structures.
Insight gained from the experimental testing was used to analyse and refine existing analytical modelling techniques. These techniques were split into two categories: 1) modelling of the local behaviour of a post-tensioned timber beam-column joint, with particular focus on stiffness and energy dissipation capacity, and 2) evaluation of the seismic demand (in the form of design base shear) on post-tensioned timber frames looking at current Force Based (FBD) and Displacement Based (DBD) design methods.
This analysis led to the development of recommended alterations in the existing beam-column joint analytical procedure enabling the procedure to provide better prediction of initial and post-yield stiffness. Analysis of the FBD and DBD procedures showed that both methods are capable of providing accurate prediction of seismic demand provided correct assumptions are made regarding system ductility and damping characteristics. Recommendations have been made on how designers can ensure that assumptions are either sufficiently accurate in the beginning of a design or require minimal iteration to be performed. Current numerical modelling techniques have also been compared against the quasi-static and dynamic testing results providing confidence in their accuracy when applied to post-tensioned timber frames. Modelling techniques were also extended to the widely used SAP2000 modelling programme which had not been previously used in post-tensioned timber research.
Although many observations and conclusions were made, a common theme continued throughout this research. This was the importance of the deep understanding of displacements within a post-tensioned timber frame and the impact of these displacements on frame performance. Displacements occur throughout a frame in dissipative reinforcing devices, in the connection of these devices, in beams, columns and joint panels as well as at the interfaces between members. When these displacements are allowed for through proper design excellent seismic performance, possible using this innovative system, is obtained.
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Modelo teórico-experimental de deterioração de postes de madeira aplicado ao Estado de São Paulo / Theoretical-experimental model of timber pole deterioration applied to the State of São PauloFreitas, Roberto Ramos de 30 September 2009 (has links)
Este trabalho tem por finalidade o estudo teórico e experimental de avaliação da degradação em postes de madeira utilizados em redes de energia elétrica. Com base em ampla revisão bibliográfica, de dados climáticos de várias cidades do Estado de São Paulo e resultados de ensaios de perfuração controlada realizadas em campo, em vários municípios do Estado de São Paulo, apresenta um modelo de apodrecimento de madeira em contato com o solo, identificando quais as cidades são mais e menos agressivas à madeira nestas condições, propondo a simplificação deste modelo, facilitando sua utilização na previsão da vida útil de madeiras em contato com o solo, predizendo o grau de deterioração destes. O modelo proposto se mostrou bastante adequado, dando uma boa previsão da deterioração de postes nas diversas regiões do Estado. / The purpose of this paper is the theoretical and experimental study of evaluation of timber deterioration in used poles in nets of electric energy. Basing on ample bibliographical reviews of climatic data of some cities in the State of São Paulo and results of controlled perforation testing done in field, in some cities of the State of São Paulo, it presents a model of timber decay in contact with the ground, identifying which cities are more aggressive or less aggressive to the wood in these conditions, proposing the simplification of this model, facilitating its use in the forecast of the timber service life in contact with the ground, predicting the degree of deterioration in them. The proposed model proved to be sufficiently adequate giving a good forecast of the pole deterioration in several regions of the State.
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Modelo teórico-experimental de deterioração de postes de madeira aplicado ao Estado de São Paulo / Theoretical-experimental model of timber pole deterioration applied to the State of São PauloRoberto Ramos de Freitas 30 September 2009 (has links)
Este trabalho tem por finalidade o estudo teórico e experimental de avaliação da degradação em postes de madeira utilizados em redes de energia elétrica. Com base em ampla revisão bibliográfica, de dados climáticos de várias cidades do Estado de São Paulo e resultados de ensaios de perfuração controlada realizadas em campo, em vários municípios do Estado de São Paulo, apresenta um modelo de apodrecimento de madeira em contato com o solo, identificando quais as cidades são mais e menos agressivas à madeira nestas condições, propondo a simplificação deste modelo, facilitando sua utilização na previsão da vida útil de madeiras em contato com o solo, predizendo o grau de deterioração destes. O modelo proposto se mostrou bastante adequado, dando uma boa previsão da deterioração de postes nas diversas regiões do Estado. / The purpose of this paper is the theoretical and experimental study of evaluation of timber deterioration in used poles in nets of electric energy. Basing on ample bibliographical reviews of climatic data of some cities in the State of São Paulo and results of controlled perforation testing done in field, in some cities of the State of São Paulo, it presents a model of timber decay in contact with the ground, identifying which cities are more aggressive or less aggressive to the wood in these conditions, proposing the simplification of this model, facilitating its use in the forecast of the timber service life in contact with the ground, predicting the degree of deterioration in them. The proposed model proved to be sufficiently adequate giving a good forecast of the pole deterioration in several regions of the State.
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Cross laminated timber: diretrizes para projeto de painel maciço em madeira no Estado de São Paulo / Cross laminated timber: guidelines for design of solid wood panel in the State of Sao PauloPassarelli, Rafael Novais 04 July 2013 (has links)
O trabalho tem o objetivo de estabelecer diretrizes para projeto de painel maciço em madeira utilizando o princípio da laminação cruzada de modo similiar ao Cross Laminated Timber (CLT), porém adequado ao setor madeireiro paulista. Não obstante, pretende-se contribuir para a difusão do conhecimento sobre sistemas construtivos com painéis maciços e ampliar a discussão sobre possibilidades de utilização da madeira na habitação. Primeiramente, foi delimitado o escopo da pesquisa e justificados os motivos que levaram à sua proposição; também foram discutidos os principais fundamentos teóricos, conceituais e metodológicos nos quais se baseia o trabalho. A seguir, as principais características de diferentes tipos de painéis maciços de madeira utilizando o princípio da laminação cruzada foram pesquisadas. Foram levantadas informações sobre as características básicas e processo produtivo de 5 produtos diferentes: Mayr Melnhof Holz BSP, Novatop Solid, Massivholz Mauer, Holz 100 e Massiv Wand 5. Depois, foi desenvolvida uma análise comparativa entre o setor madeireiro na Áustria, país que atualmente concentra a maior produção de CLT na Europa Central, e no Estado de São Paulo, local no qual se pretende avaliar as possibilidades e limitações para produção dos painéis maciços em madeira. A análise comparativa foi dividida em duas etapas: na primeira etapa foram analisadas as reservas florestais e indústria madeireira austríaca e paulista; na segunda etapa foram elaboradas estimativas de custo para a produção de um elemento vertical constituído por núcleo maciço utilizando o princípio da laminação cruzada em Viena e na região metropolitana de São Paulo. Por fim, relacionando as características do produto e sua influência no processo produtivo com as possibilidades e limitações proporcionadas pelo setor madeireiro paulista, foram estabelecidas diretrizes para o projeto de um painel maciço em madeira que utilize o princípio da laminação cruzada. As diretrizes foram elaboradas dos pontos de vista da utilização da madeira, do desenho do painel e de sua adaptação ao setor madeireiro paulista. A seguir, foi desenvolvido uma proposta preliminar para desenho de painel maciço. As informações levantadas durante o desenvolvimento desta dissertação foram obtidas por meio de visita às fábricas, pesquisa em teses e publicações relacionadas e pesquisa na página de internet dos fabricantes dos produtos. / The work aims to establish guidelines for cross laminated solid timber panel design, suitable to the forestry industry in São Paulo. It intendeds to contribute for knowledge diffusion about this building system and enhancing the discussion on timber construction in Brazil. First, the research\'s scope was explained as well as its main questions, hypothesis and objectives. Then, the main features of different types of cross laminated solid timber panels and it\'s production process were analysed. Information on the basic features and production process of five different products were gathered: Mayr Melnhof Holz BSP, Novatop Solid, Massivholz Mauer, Holz 100 and MassiveWand 5. Hereafter, a comparative analysis between the forestry industry in Austria, currently the largest cross laminated timber producer in Central Europe, and the State of São Paulo was developed. The analysis was divided into two stages: in the first stage, forest reserves and timber industry in Austria and in the State of São Paulo were investigated; in the second stage, cost estimates for the production of a solid timber vertical element in Vienna and in the metropolitan area of São Paulo were developed. Finally, all the information gathered previously was used in order to establish design guidelines for cross laminated solid timber panel relating product\'s design influence on the production process and the possibilities and limitations offered by the forestry industry in São Paulo. The guidelines were developed from the point of view of timber utilisation, panel design and its adaptation to São Paulo\'s forestry industry. Then, a preliminary solid wood panel proposal has been developed as a way to synthesise the guidelines set previously.Information for the research was obtained through factory visits, theses and related publications and research on the manufactures website.
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