Made available in DSpace on 2014-06-11T19:30:21Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-01-25Bitstream added on 2014-06-13T20:20:47Z : No. of bitstreams: 1 garcia_fm_me_botfca.pdf: 824639 bytes, checksum: 85eb7a18c33c01e8fedee4bb52011f47 (MD5) / Madeira é um material que vem sendo largamente utilizado pela humanidade ao longo da história. No Brasil que é um país rico em florestas nativas, ocorre por inúmeras vezes a exploração desenfreada desses recursos. O Cambará (Qualea albiflora Warm.) está entre as espécies de grande interesse do setor madeireiro por ser uma matéria prima de baixo custo e de alta durabilidade tornando a espécie visada pelos empresários desse setor. Com isto o presente trabalho tem como objetivo avaliar o rendimento de uma serraria beneficiando esta espécie como produto final de vigamento de várias medidas, procurando identificar os parâmetros significativos que devem ser levados em consideração no momento de seu beneficiamento. Em 895 árvores abatidas de Cambará apresentando amplitude de comprimento entre 2,50 e 8,00 metros e variação de diâmetro de 33 a 80 centímetros, oriundos de manejo florestal na região de Alta Floresta-MT sendo analisados os parâmetros intimamente relacionados com o rendimento que são o diâmetro, comprimento, número de toras beneficiadas ao longo do dia e quantidade em m³ de toras beneficiadas. Após o beneficiamento, foram avaliados os resultados diários referentes ao total de vigamentos, bem como seu rendimento diário percentual. O rendimento das toras de Cambará foi de 48,90%. Esse valor está de acordo com a literatura para os produtos analisados e para a amplitude de rendimento considerada normal para madeiras de folhosas (45-55%). A serraria não apresentou linearidade nos seus rendimentos, o que pode onerar os custos de produção e manutenção de seus maquinários. Por esse motivo, é importante salientar que não se deve analisar apenas o rendimento das toras como fator limitante do sucesso de uma empresa madeireira, haja vista que o cálculo desse parâmetro é feito por meio de proporção entre o total de madeira serrada e o total do metro cúbico de tora / Wood is material that has been widely used by humanity throughout history. In Brazil it is a country rich in native forests, occurs by unbridled exploitation of these countless times. The Cambará (Qualea albiflora Warm.) is among the species of great interest of the wood sector by being a low-cost raw material and high durability making the species targeted by entrepreneurs in this sector. The present work aims to evaluate the performance of a sawmill benefiting this species as the end product of framework of several measures, seeking to identify significant parameters that must be taken into consideration at the time of their processing. In 895 trees felled to cambará showing extent of length between 8.00 and 2.50 meters and variation of diameter of 33 to 80 cm from forest management in the region of Alta Floresta-MT, being analyzed parameters closely related income that are the diameter, length, number of logs benefited throughout the day and quantity in m³ of logs. After processing, the results were evaluated for the daily total of frames, as well as your daily income percentage. The yield of logs of Cambará was 48.90%. This value is consistent with the literature for the products examined and for the breadth of income considered normal for wood of hardwoods (45-55%). Despite this, the sawmill does not present a linearity in their income, which may charge the costs of production and maintenance of their machines. For this reason, it is important to stress that one should not look at only the yield of logs as a limiting factor of the success of a logging company, given that the calculation of this parameter is done by means of the ratio of the total of lumber and the total cubic meter of logs

Stormwater runoff from log yards in different BC regions can affect aquatic habitats to varying degrees given differences in weather, water quality and tree species. The objective of this thesis was to compare runoff quality and total runoff loadings from a coastal and interior log yard. Chemical analyses, toxicity tests and treatments were conducted. Data were compared to criteria, statistically compared between sites and assessed for seasonal trends. Export coefficients (ECs) were compared between sites. Relationships between toxicological and chemical variables were explored statistically. Runoff toxicity was similar between sites and fairly low. LC50s for 48-hour Ceriodaphnia dubia tests ranged from 32.95 to > 100 and 58.70 to > 100 for coastal and interior runoff, respectively. Microtox ®.5 minute EC50s ranged from 27.12 to > 100 for coastal runoff and 22.22 to > 100 for interior runoff. Several metals and dehydroabietic acid (DHA) exceeded criteria in runoff from both sites. Biochemical oxygen demand, alkalinity, pH and metals were significantly higher (p < 0.05) at the interior site. Sodium and conductivity were higher at the coastal site. No seasonal differences in runoff quality were observed. Therefore, acute effects would occur during periods of high runoff, during autumn at the coastal site and late winter at the interior site. The unpaved interior site generated less runoff per square meter due to ground infiltration. ECs were comparable to the paved coastal site. Exceptions to this include tannins and lignin (11 fold higher at the coastal site) and DHA (9 fold higher at the interior site). C. dubia toxicity was partially associated with TSS for both sites. Tannins and lignins were correlated (r² =0.91) with C. dubia toxicity for coastal runoff. Tannin and lignin concentrations ranged from 45 to 263 mg/L and 43 to 75 mg/L in coastal and interior samples, respectively. Since results suggest that TSS is partially responsible for toxicity, and since contaminants are often bound to TSS, source control and treatment options for TSS should be implemented. / Science, Faculty of / Resources, Environment and Sustainability (IRES), Institute for / Graduate

Different management regimes consisting of range of site indices and planting densities were simulated to evaluate price premiums required for growing high-quality southern pines across the southern United States. Optimal management regimes were identified maximizing the land expectation value. Growing high-quality pines on longer rotations are economically feasible, however, forest landowners need premiums which ranged from $1.40/ton to $9.81/ton for 10-year rotation extension and increased significantly with rotation ages. In uneven-aged management, price premiums for 5-year cutting cycle extension ranged from $1.75/ton to $2.25/ton. Additionally, sawmill’s willingness-to-pay price premiums for high-quality pine sawtimber were calculated using a mail survey. Sawmills showed a considerable interest in paying price premiums which ranged from $4.22/ton to $12.98/ton. Factors affecting mean WTP price premiums were sawlog size, procurement radius, grade, mill’s capacity, and employees. These findings will help landowners in deciding whether to extend rotation ages of their forest for growing higher quality pines.

De acordo com o Plano Nacional de Resíduos Sólidos - PNRS, a destinação de resíduos industriais é de responsabilidade do seu gerador. Serrarias do estado de Roraima enfrentam uma série de dificuldades para cumprimento desta norma, principalmente, pela falta de informações e ausência de estudos que comprovem alternativas viáveis específicas para a região. Sabe-se, contudo, que de uma forma ampla e genérica, alternativas poderiam ser propostas. Dentre elas, a conversão direta dos resíduos para geração de energia e a pirólise visando a produção de carvão vegetal e seus co-produtos. Neste sentido, o objetivo geral deste estudo foi identificar, caracterizar e realizar análises a isto vinculadas, considerando os resíduos madeireiros gerados nas serrarias localizadas no pólo de Rorainópolis, Roraima, Brasil. Foram realizadas aferições da granulometria, umidade, composição química, densidade e poder calorífico do material in natura (CAPÍTULO 1). Ainda sobre este material foram realizadas carbonizações à temperatura de 450°C e 650°C e avaliação do carvão vegetal e gases do processo (CAPÍTULO 2). Além disso, foram avaliadas as características físicas, químicas, energéticas dos resíduos obtidos em diferentes seções das pilhas preexistentes nas serrarias (CAPÍTULO 3). / According to the National Solid Waste Plan - PNRS, a destination of industrial solid waste is responsibility of it generator. Roraima\'s sawmills face a series of difficulties to comply this standard, mainly for lack of studies proving feasible alternatives specific to region. It is known, however, that of broad and generic form can be applied alternatives. Among them, the direct conversion of the waste to the generation of energy and pyrolysis for the production of charcoal and co-products. In this sense, the general objective of this study was to identify, characterize and carry out related analyzes, considering the wood residues generated at sawmills located at the Rorainópolis Timber Hub, state of Roraima, Brazil. The granulometry, moisture, chemical composition, density and calorific value of the in natura material were measured (CHAPTER 1). Carbonisations were also carried out at 450°C and 650°C and charcoal and process gases were evaluated (CHAPTER 2). In addition, the physical, chemical and energetic characteristics of residues obtained in different sections of the pre-existing piles in the sawmills were evaluated (CHAPTER 3).

The biggest obstacle to robust color image processing of wood is in developing a color model that represents all possible defect colors. When the color model is too general or too specific, defect recognition fails because too many or too few non-defect pixels match the model, respectively. Because a color image of wood contains far more clear and clear-grain colored pixels than grain-knot and knot colored pixels, it is beneficial to first statistically identify and remove the clear and clear-grain colors and to use the accumulated data to simultaneously enhance and normalize the remaining grainknot and knot colored pixels. This process is here called adaptive color correlation. The normal image processing strategy is to search and test for defect features directly. The strategy proposed and developed here is to instead classify all wood pixels containing non-defect colors first, and then identify defect features. Once non-defect features are removed from an image, the task of finding candidate defects becomes easier and faster. This improvement is realized in a sigmoid-shaped color correlation implemented as an adaptive look-up table. As wood has become more expensive relative to manufacturing costs, more efficient methods of maximizing the recovery of clear wood in every board are sought. Optimization, in the present context, is a broad term for selecting products that are made from wood boards so the value of products produced is maximized for a given production requirement. Wood contains random defects which prohibit the production of some products. The normal optimization strategy is to mathematically change the value of under/over-produced products directly. The strategy proposed and developed here is to instead separate optimization into two steps: 1) determine all possible product solutions for a board; and 2) select the single best solution that satisfies value and production goals. Maximum utilization of clear wood is achieved because the solution is "frozen" before mathematically changing the value of products. Recovering long-lengths of clear wood is achieved because various length-based valuation strategies may be implemented as postsolution processes. Separating the product selection process from the solution generation process is shown by this work (simulation) to maximize value recovery.

Outsourcing can be defined as transferring an activity from internal to external control. This thesis studies outsourcing in the wood product manufacturing (WPM) sector from both a customer and supplier perspective. The research design is a multiple case study approach, and it is based on six Scandinavian companies in the door, floor and window industries and one larger supplier of raw material. This study provides an understanding of driving forces for outsourcing in a different context than previously studied and has identified cost reduction in combination with reallocating resources from non-core activities as main driving forces. Compared to several other industrial sectors, outsourcing strategies for the WPM firms have little to do with accessing external sources’ capabilities. In the literature, there is often a main focus on the strategic level of outsourcing, however, such heavy resource-based focus in terms of a core competence approach in the formulation of outsourcing strategies at the customer side risks forgetting that components can still be vulnerable to supplier failure. Here, more focus needs to be put on the operational level when considering outsourcing. This thesis illustrates customers considering outsourcing where there are not any given outsourcing supplier partners developed. At the same time, for the supplier side, forward integration and specialising by taking over outsourcing is complicated by an initial divergent production flow of sawn timber. When not all contexts have developed supplier markets for directly managing outsourcing, it should not be assumed that general outsourcing models are directly applicable. In general, the question of whether or not to outsource seems too complex to simply be considered as either “in or out”. A company needs safeguards when conducting outsourcing and in a situation where there is a non-developed supplier market, parallel in-house production becomes an alternative.

Sammanfattning   Björk kan ge ett bra virke och med undantag för sämre fukttålighet finns endast formella restriktioner i virkets användning i relation till tall och gran. Trots detta och trots att det finns gott om björkråvara i landet är den sågade och använda björkvolymen påfallande liten. Björken utgör därför en underskattad skoglig och industriell resurs vars utnyttjande skulle kunna öka kraftigt.   Björken har varit ett lågprioriterat virke vilket sannolikt på grund av dålig skötsel påverkat kvalitén på våra nuvarande björkskogar och plantmaterialet. Det har också lett till att vi saknar tradition i vid mening att arbeta med björken. Forskning och utbildning fokuserar på barrvirke varför lövets, och då särskilt björkens möjligheter inte tillvaratas.   Björken kräver andra skötselmetoder än barrträden men utnyttjas dessa finns förutsättningar att skapa bra produktionsskogar både med avseende på volym och kvalitet. Mer forskning behövs dock i frågan om betesskador och hur dessa kan reduceras. Bra björktimmer kan pris- och lönsamhetsmässigt vara intressantare för skogsägaren än motsvarande barrtimmer. Dessa kunskaper måste nå ut till skogsägarna för att de skall förstå att det finns attraktiva alternativ till att slentrianmässigt anlägga nya tall- eller granskogar efter en föryngringsavverkning. Utöver det goda arbetet som Skogsstyrelsen gör med allmänna skötselråd gällande björkskogen borde de mer aktivt arbeta med skogsägarna för att stimulera till ett mer kommersiellt utnyttjande av björken. Denna uppmaning gäller även andra berörda parter vilket inkluderar skogsägarens alla rådgivare.   Den helt dominerande volymen av avverkad björk går i dagsläget till massabruken. Det finns flera skäl till detta. Ett kan vara att kvaliteten inte alltid svarar mot sågverkens krav men andra skäl är hanterings- och logistikproblem med att hantera små volymer sågtimmer och bristande kunskaper både hos skördarföraren och hos skogsägaren. Hade skogsägaren haft de goda förtjänstmöjligheterna på björktimmer klar för sig vid avverkningen hade han kunnat ge noggrannare instruktioner om hur björkvirket skulle hanteras.   Sågverken som hanterar björk är få och relativt små. För en verklig volymproduktion av björktimmer behövs en resurs- och teknikutbyggnad. Vissa satsningar görs men mer behövs. Dessa satsningar måste göras utifrån ett verkligt marknadsmässigt perspektiv. Vem skall svara för nödvändiga investeringar? Var finns industrin, riskkapitalisterna och investerarna som är beredda att satsa på en fabrik för svensk björkplywood eller byggsystem som inkluderar björk? Lönsamheten är inget att skryta med och branschen utövar ingen stor lockelse för nya entreprenörer. Även här kommer marknadsaspekterna in. Det behövs industriell efterfrågan på stora volymer sågad björk för att konstituera en verklig marknad. För att skapa denna räcker det inte med en satsning på snickeriindustrin utan björk måste även i Sverige användas som ett naturligt virke i byggsammanhang. Boverket har här en nyckelroll och måste anpassa svenska normer till motsvarande europeiska så att det blir möjligt att interiört bygga också med björk. Vem driver den frågan? Vem stimulerar arkitekter och byggnadskonstruktörer till att bygga med björk? På samma sätt som det sätts upp priser för bästa trähus kunde det möjligen också skapas ett pris för bästa anläggning byggd i björk. Hur kan man skapa intresse hos en kommun, ett företag eller organisation att genomföra ett profilbygge i björk? Sveriges Träbyggnadskansli är en lämplig mottagare av detta budskap men det borde finnas fler.   I takt med att skogens miljömål accentueras blir lövskogen än viktigare. Lika viktigt är då att alla parter samverkar för att skogsägaren som sköter sin lövskog på ett bra sätt skall få avsättning för sitt virke till acceptabla villkor. Skogsstyrelsen måste också ha en positiv syn på lövavverkningen och inte av miljöskäl i en framtid stoppa denna när den blir aktuell. Blotta misstanken hos skogsägaren att så kan bli fallet kommer att leda till ett minskat intresse för lövskogen.   Lövträ är inget homogent begrepp och egenskaperna skiljer sig märkbart mellan t.ex. al, alm, ask, lönn å ena sidan och björk å den andra. Det finns ingen anledning att i detta sammanhang tala om björk i allmänna ordalag som ett lövträd utan björk är björk och inget annat och skall så behandlas.   Sammanfattningsvis har vi gott om björk vars virke kan användas på mångahanda sätt. Att så inte sker kan inte förklaras av någon enstaka faktor. För att få en ändring till stånd krävs i första hand ett renodlat marknadsmässigt tänkesätt med ökad information och kunskap i alla led. Det talas om att skogsnäringen måste marknadsorientera sig i sin verksamhet. Detta gäller hela kedjan från skogsägaren till slutkonsumenten av skogsprodukten. / Summary in English   Sweden is a forest country with a standing wood balance of more than 3 000 million m3sk. Pine and spruce are dominating species but there is also a wood balance of some 420 million m3sk of birch. Birch is offering excellent timber properties and is well matching both pine and spruce with the exception of its sensitivity to moisture. Despite of this, quite small quantities of birch timber are being used in Sweden. Most birch wood being cut is used for the production of paper and pulp (95%). Although the birch tree is an old species in Sweden it was during the 2000th century until the end of the 1970s treated as a weed and was struggled with by means of herbicides. Subsequently Sweden lost knowledge and experience in how to deal with this wood which in turn leads to a poor quality of now existing clumps of birch trees. Compared to coniferous trees little research has been done of broadleaf trees but it’s anyhow known that the clearing and thinning of birch trees have to be stricter than that of softwood. Birch trees have an interesting potential with a shorter production cycle than pine and spruce. Used for timber the yield for the forest owner could be quite interesting. Broadleaf trees are also playing an important role to improve the overall environment.   To increase the use of birch wood more information about this specific timber has to be spread to all parties concerned. That involves owners of forest land, silviculture, sawmills, industry and distributors. Activities along the chain of actors have to be market oriented and include economic incentives for parties concerned. To be able to increase the volume of birch timber used new areas of deployment have to be found outside the traditional production of furniture etc. An interesting area is then the building industry.

<h1>       Sammanfattning</h1><p> </p><p>Björk kan ge ett bra virke och med undantag för sämre fukttålighet finns endast formella restriktioner i virkets användning i relation till tall och gran. Trots detta och trots att det finns gott om björkråvara i landet är den sågade och använda björkvolymen påfallande liten. Björken utgör därför en underskattad skoglig och industriell resurs vars utnyttjande skulle kunna öka kraftigt.</p><p> </p><p>Björken har varit ett lågprioriterat virke vilket sannolikt på grund av dålig skötsel påverkat kvalitén på våra nuvarande björkskogar och plantmaterialet. Det har också lett till att vi saknar tradition i vid mening att arbeta med björken. Forskning och utbildning fokuserar på barrvirke varför lövets, och då särskilt björkens möjligheter inte tillvaratas.</p><p> </p><p>Björken kräver andra skötselmetoder än barrträden men utnyttjas dessa finns förutsättningar att skapa bra produktionsskogar både med avseende på volym och kvalitet. Mer forskning behövs dock i frågan om betesskador och hur dessa kan reduceras. Bra björktimmer kan pris- och lönsamhetsmässigt vara intressantare för skogsägaren än motsvarande barrtimmer. Dessa kunskaper måste nå ut till skogsägarna för att de skall förstå att det finns attraktiva alternativ till att slentrianmässigt anlägga nya tall- eller granskogar efter en föryngringsavverkning. Utöver det goda arbetet som Skogsstyrelsen gör med allmänna skötselråd gällande björkskogen borde de mer aktivt arbeta med skogsägarna för att stimulera till ett mer kommersiellt utnyttjande av björken. Denna uppmaning gäller även andra berörda parter vilket inkluderar skogsägarens alla rådgivare.</p><p> </p><p>Den helt dominerande volymen av avverkad björk går i dagsläget till massabruken. Det finns flera skäl till detta. Ett kan vara att kvaliteten inte alltid svarar mot sågverkens krav men andra skäl är hanterings- och logistikproblem med att hantera små volymer sågtimmer och bristande kunskaper både hos skördarföraren och hos skogsägaren. Hade skogsägaren haft de goda förtjänstmöjligheterna på björktimmer klar för sig vid avverkningen hade han kunnat ge noggrannare instruktioner om hur björkvirket skulle hanteras.</p><p> </p><p>Sågverken som hanterar björk är få och relativt små. För en verklig volymproduktion av björktimmer behövs en resurs- och teknikutbyggnad. Vissa satsningar görs men mer behövs. Dessa satsningar måste göras utifrån ett verkligt marknadsmässigt perspektiv. Vem skall svara för nödvändiga investeringar? Var finns industrin, riskkapitalisterna och investerarna som är beredda att satsa på en fabrik för svensk björkplywood eller byggsystem som inkluderar björk? Lönsamheten är inget att skryta med och branschen utövar ingen stor lockelse för nya entreprenörer. Även här kommer marknadsaspekterna in. Det behövs industriell efterfrågan på stora volymer sågad björk för att konstituera en verklig marknad. För att skapa denna räcker det inte med en satsning på snickeriindustrin utan björk måste även i Sverige användas som ett naturligt virke i byggsammanhang. Boverket har här en nyckelroll och måste anpassa svenska normer till motsvarande europeiska så att det blir möjligt att interiört bygga också med björk. Vem driver den frågan? Vem stimulerar arkitekter och byggnadskonstruktörer till att bygga med björk? På samma sätt som det sätts upp priser för bästa trähus kunde det möjligen också skapas ett pris för bästa anläggning byggd i björk. Hur kan man skapa intresse hos en kommun, ett företag eller organisation att genomföra ett profilbygge i björk? Sveriges Träbyggnadskansli är en lämplig mottagare av detta budskap men det borde finnas fler.</p><p> </p><p>I takt med att skogens miljömål accentueras blir lövskogen än viktigare. Lika viktigt är då att alla parter samverkar för att skogsägaren som sköter sin lövskog på ett bra sätt skall få avsättning för sitt virke till acceptabla villkor. Skogsstyrelsen måste också ha en positiv syn på lövavverkningen och inte av miljöskäl i en framtid stoppa denna när den blir aktuell. Blotta misstanken hos skogsägaren att så kan bli fallet kommer att leda till ett minskat intresse för lövskogen.</p><p> </p><p>Lövträ är inget homogent begrepp och egenskaperna skiljer sig märkbart mellan t.ex. al, alm, ask, lönn å ena sidan och björk å den andra. Det finns ingen anledning att i detta sammanhang tala om björk i allmänna ordalag som ett lövträd utan björk är björk och inget annat och skall så behandlas.</p><p> </p><p>Sammanfattningsvis har vi gott om björk vars virke kan användas på mångahanda sätt. Att så inte sker kan inte förklaras av någon enstaka faktor. För att få en ändring till stånd krävs i första hand ett renodlat marknadsmässigt tänkesätt med ökad information och kunskap i alla led. Det talas om att skogsnäringen måste marknadsorientera sig i sin verksamhet. Detta gäller hela kedjan från skogsägaren till slutkonsumenten av skogsprodukten.</p><p> </p><p> </p> / <h1>Summary in English</h1><p> </p><p>Sweden is a forest country with a standing wood balance of more than 3 000 million m³sk. Pine and spruce are dominating species but there is also a wood balance of some 420 million m³sk of birch. Birch is offering excellent timber properties and is well matching both pine and spruce with the exception of its sensitivity to moisture. Despite of this, quite small quantities of birch timber are being used in Sweden. Most birch wood being cut is used for the production of paper and pulp (95%). Although the birch tree is an old species in Sweden it was during the 2000th century until the end of the 1970s treated as a weed and was struggled with by means of herbicides. Subsequently Sweden lost knowledge and experience in how to deal with this wood which in turn leads to a poor quality of now existing clumps of birch trees. Compared to coniferous trees little research has been done of broadleaf trees but it’s anyhow known that the clearing and thinning of birch trees have to be stricter than that of softwood. Birch trees have an interesting potential with a shorter production cycle than pine and spruce. Used for timber the yield for the forest owner could be quite interesting. Broadleaf trees are also playing an important role to improve the overall environment.</p><p> </p><p>To increase the use of birch wood more information about this specific timber has to be spread to all parties concerned. That involves owners of forest land, silviculture, sawmills, industry and distributors. Activities along the chain of actors have to be market oriented and include economic incentives for parties concerned. To be able to increase the volume of birch timber used new areas of deployment have to be found outside the traditional production of furniture etc. An interesting area is then the building industry.</p>

The goal of this study was to assess the potential of using hardwood lumber in CLT manufacturing. The goal was achieved by addressing four specific objectives. The first objective was to collect CLT manufacturers' perspectives for using hardwood lumber in the current manufacturing setup. The second objective was to determine hardwood sawmills' current ability to produce structural grade lumber (SGHL) from low value logs as a product mix through a survey of hardwood lumber producers in the US. The third objective was to conduct a log yield study of SGHL production from yellow poplar (YP) logs to produce 6'' and 8'' width SGHL to match the PRG 320 requirements. The fourth objective was to determine CLTs' production cost using SGHL and compared it with the CLTs manufactured from southern yellow pine (SYP). The results suggest that all three CLT industries visited and interviewed had sufficient technology to produce hardwood CLTs. The production of hardwood CLTs was mainly limited by the quality and quantity of lumber available. The hardwood sawmill survey results indicated that, currently, less than 10% of the sawmills had all the resources required to produce SGHL. The current ability of the sawmills was measured based on the resources necessary to begin SGHL production. Forty percent of the sawmills would require an investment in sawing technology to saw SGHL, 70% would require employing a certified lumber grader, and 80% would require a planer to surface lumber. Another significant finding was the sawmills' willingness to collaborate with other sawmills and lumber manufacturers. More than 50% of sawmills were open to potential collaboration with other stakeholders if necessary, which is crucial to commercializing SGHL for a new market. The log yield study of yellow poplar helped demonstrate that the mixed grade lumber production method to convert lumber from lower quality zones as SGHL yields higher lumber volume for sawmills and at the same time reduces lower-grade lumber volume. On average, SGHL production increased lumber volume by more than 6% compared to only NHLA grade lumber production when 65% of the lumber was converted to SGHL. The volume of lower lumber grades from 2 common and below decreased from an average of 85% to less than 30% when producing SGHL as a product mix with NHLA grade lumber. This study observed more than 95% of SGHL as Number 3 and better lumber grades. At estimated lumber value, 2x6 and 2x8 SGHL and NHLA grade lumber production as product mix from a log generate higher revenue for all log groups except for the diameter 13" logs. A lower percentage of higher-grade lumber was observed for diameter 13’’ logs than other log groups from this experiment, which resulted in lower revenue. Production cost of CLTs was determined based on the lumber value to manufacture 40' x 10' plain panels with different combinations by lumber grade of yellow poplar and southern yellow pine lumber alone. Production cost was determined by assuming that lumber value contributes 40% of CLTs' total production cost. The 3- ply CLT panels were manufactured using S. Selects lumber in a major direction, and No 1-grade lumber in the minor direction from YP had a production cost of $662.56 per cubic meter, which cost only $643.10 when SYP lumber was used at referenced lumber value. This study concludes that CLT panels from YP cost 3-7 % more than SYP-CLTs at the referenced lumber values. / Ph.D. / This research aims to expand the hardwood lumber consumption in the US by evaluating the opportunity to manufacture cross-laminated timber (CLTs). First, CLT manufacturing industries were visited to know their current capacity to process hardwood lumber. The results suggest that all three CLT industries had sufficient technology to produce hardwood CLTs, and the production was mainly limited by the quality and quantity of lumber available. Commercially hardwood can be used in CLT manufacturing if it can be used for structural application. Hardwood lumber must meet the structural application's minimum requirements to manufacture the structural grade CLTs, so we surveyed the hardwood sawmills to know if they have the required resources to manufacture the structural grade hardwood lumber (SGHL). Only ten percent of the sawmills had required technology to produce SGHL without additional investments. Production of the SGHL also required to generate more revenue for the hardwood sawmills, so we conducted the log yield study to know how the revenue structure of sawmill operation will change from the mixed grade lumber production. At estimated lumber value, 2x6 and 2x8 SGHL and 1-inch National Hardwood Lumber Association (NHLA) grade lumber production as product mix from logs generate higher revenue for all log groups except for the diameter 13" logs. Finally, the production cost of SGHL from the log yield study was evaluated and used to produce CLTs at 40% production cost from lumber at 15% profit margins for sawmills and compare with southern yellow pines CLTs. The results indicate that yellow poplar CLTs cost 3-7 % more than southern yellow pines CLTs at the referenced lumber values. This study concludes that hardwood lumber can be used in CLT manufacturing, so there is an opportunity for hardwood sawmills to expand the market. The first step for commercial production of hardwood CLTs is to produce SGHL on a commercial scale, given that sawmills can benefit from these new products in the current lumber market and meet the minimum requirements of the CLT raw materials.

Work is an essential activity that provides goods or services of value to oneself and others. Paradoxically, in a bid for self-realisation, workers are seriously endangered. Work-related or induced diseases and stresses pose serious threats to workers’ health and the general well-being, hence, the need to seriously consider the issue of occupational health and safety of workers. In terms of safety at work, the experience of small and medium scale enterprises (SMSEs) worldwide is that of neglect. Their incomes are very low and uncertain, coupled with high levels of risk and hazard in their work, with little or no social protection coverage (Chen, 2008). This study therefore examines how environmental and sociological factors determine occupational health and safety of workers in SMSEs in Lagos State, Nigeria. Ulrich Beck “Risk Society” theory, Political Economy of Health framework (PEH) (Minkler et al 1994, Linnan et al, 2001) and Labour Process Theory (LPT) (Braverman, 1974; Marx, 1976; Bottome, 1991) underpinned the study. The study adopts both the qualitative and quantitative methods of data collection. The qualitative method includes field observation of the selected workplaces, six Focus Group Discussion (FGD) and eight In-depth interviews (IDIs). The quantitative involved the use of structured questionnaire. The sample survey involved 180 respondents in a multi-stage sampling technique from purposively selected sawmills, mechanic villages and blacksmith cottages in three Local Government Areas in Lagos State. The quantitative data analysis uses simple percentile and univariate analyses, while the qualitative data are content-analysed, based on the objectives of the study. The findings identified low level of education (60.5%), and poor awareness of OHS in SMSEs (86.1%). It further reveals poor physical (69.5%) and technological environment (70.5%), unavailability of OHS facilities (60.5%) and prevention methods by manager/owners (60.5%), carefree attitudes of workers/managers/owners to OHS (69.5), non-acquaintance of workers to OHS laws (86.1%), workers’ economic incapacitation to deal with issues of occupational hazard (76.1%), lack of enforcement of OHS (88.3%), and transferring knowledge on OHS (82.2%) in the selected SMSEs. The study recommends roles for managers/owners, workers, trade associations, government, non-governmental organisations to promote effective OHS in the selected SMSEs. / Sociology / D.Phil. (Sociology)