Prasidėjus antrajai sovietinei okupacijai, Lietuva prievarta inkorporuota į Sovietų Sąjungą. Pramonė Lietuvoje po karo buvo itin skurdi. Todėl kreiptas didelis dėmesys jos atstatymui. Medžio apdirbimo pramonė Šiaulių mieste sovietmečiu reikšmingesnio valdžios dėmesio nesulaukė. Po karo trūko miško medžiagos, o aplink Šiaulius miškų beveik nebuvo (iškirto okupacinė nacių kariuomenė). Kaip vieną pagrindinių medžio apdirbimo įmonių Šiaulių mieste galima išskirti medžio apdirbimo kombinatą, kuris įkurtas 1944 m., susivienijus Navicko lentpjūvei, įmonei „Guoba“, lentpjūvei – malūnui „Skirpstas“, Lazdinio lentpjūvei. Kombinatas buvo pavaldus Lietuvos SSR Miškų pramonės komisariatui. 1949 vasario 10 d. Lietuvos miškų ir popieriaus pramonės ministerijos įsakymų likviduotas Šiaulių baldų fabrikas ,,Rūdė“, kuris įjungtas į Šiaulių medžio apdirbimo kombinato sudėtį. 1974 sausio 8 d. Lietuvos SSR baldų ir medžio apdirbimo pramonės ministerijos įsakymu buvo reorganizuotas kombinatas į Šiaulių baldų susivienijimą ,,Venta“. / As the second Soviet occupation commenced, Lithuania was forcibly incorporated in the Soviet Union. Industry in Lithuania was very poor after the war. Therefore a lot of attention was paid to rebuilding it. Wood processing industry in Šiauliai City did not receive any significant attention from the authorities during the Soviet period. There was a lack of timber after the war and there almost were no forests nearby Šiauliai (they were cut down by the occupant Nazi army). A wood processing factory established in 1944 upon merger of Navickas Sawmill, Company “Guoba”, Sawmill – Mill “Skirpstas”, Lazdinis Sawmill can be distinguished as one of the major wood processing companies in Šiauliai City. The Factory was subordinate to the Lithuanian SSR Forest Industry Headquarters. Šiauliai Furniture Factory “Rūdė” was liquidated on 10 February 1949 subject to an Order of the Ministry of Lithuanian Forest and Paper Industry and was incorporated in Šiauliai Wood Processing Factory. The Factory was reorganized into Šiauliai Furniture Association “Venta” on 8 January 1974 following Order of Ministry of Furniture and Wood Processing Industry of Lithuanian SSR.

New Zealand has ratified the Kyoto Protocol and agreed to reduce greenhouse gas emissions to 1990 levels in the first commitment period 2008-2012. Energy generated from renewable sources, such as New Zealand plantation forests and wood processing sites, is considered greenhouse gas neutral. But the use of biomass for bioenergy in New Zealand is very small. Some of the reasons for this include a lack of information about the future fuel supply and delivered cost. This thesis aims to provide a methodology to estimate biomass fuel availability and the delivered cost, of a range of forest and wood processing sources within a district, and to analyse the impact of harvest age, harvesting practices, terrain, collection and chipping costs, opportunity cost and transport costs on the availability and delivered cost of biomass for bioenergy. The six biomass streams included were chiplogs, forest landing residues, cutover residues, sawdust, bark and chip. The methodology was developed based on an area in Canterbury, and tested on an area in the Nelson/Marlborough region. It utilises forest growth models, Geographic Information Systems and Microsoft Excel. Growth models allow the analysis to be customised to a particular area or region, while the use of GIS allows the model to take spatial aspects (for example slope and transport distance) into consideration. Developing the overall framework within Excel allows easy analysis of the results and changes to the underlying assumptions. Opportunity costs make up a large proportion of the total cost of delivery for the chiplog, sawdust, bark and chip biomass and need to be included in any estimate of cost for these biomass streams. The logistic system chosen for collecting and chipping the forest residues has a large impact on their delivered cost as do the transport costs. However transport cost is not the most significant influence on the delivered cost of other biomass streams. The use of biomass for electricity generation only is not currently economic in either of the areas analysed. The use of biomass for heat production is currently economic if compared to the electricity purchase price.

Lower tolerance limits (LTLs) methods was used to estimate design values of furniture joints. To have higher reliability in joint, LTLs were chosen for higher confidence/proportional level. The logic behind phenomena is that if stress on joint exceeds the given LTLs, failure on joints is most likely observed. Therefore, joint sizes were determined to maintain internal stresses on joint below LTLs value corresponding to external load.

Didžiulės elektros energijos vartojimo sąnaudos karkasinių namų gamyboje ganėtinai ženkliai didina gamybos savikainos kaštus, kas tiesiogiai atsiliepia įmonės pelnui. Medienos apdorojimo pramonės produkcijos galima pagaminti gerokai daugiau (arba pagaminant tą patį kiekį suvartoti mažiau elektros energijos), ne vien tik kuriant naujus didesnio našumo medienos apdirbimo įrenginius, bet ir racionaliai naudojant esamus, bei nuolat juos modernizuojant. Šiame darbe tiriamas karkasinius namus gaminančios ir statančios įmonės UAB „Namų statyba“ elektros energijos suvartojimas. Buvo siekiama nustatyti elektros energijos taupymo galimybes, iš įmonės elektros energijos suvartojimo pereiti prie energijos sunaudojimo normos vienam karkasiniam namui pagaminti. Atlikus tyrimą nustatyta, kurioje medienos apdirbimo operacijoje galima būtų sumažinti elektros energijos suvartojimą. Taip pat pateikiami pagrįsti elektros energijos efektyvumo didinimo būdai. / Engineering prime costs increase because of a great consumption input of electricity energy at framework house manufacture, which directly influence company profit. It is possible to produce much more wood processing industry output (or to consume less electricity energy while producing the same quantity), not only by creating new mechanisms of greater wood processing productivity, but also by racionally using the present ones and constantly modernizing them. The consume of electricity energy of the JSC „Namų statyba“ which specializes at manufacturing and building framework houses is being researched at this work. The target was to estimate the saving potencial of electricity energy and to come from company electricity energy consume to the norm of electricity energy that is necessary to build a single framework house. Wood processing operation at which it is possible to reduce electricity energy consumtion was estimated after the research. The reasoned methods how to increase the effectiveness of electricity energy are presented as well.

Made available in DSpace on 2016-12-12T20:25:11Z (GMT). No. of bitstreams: 1 Daniel Giovani Possamai.pdf: 5728163 bytes, checksum: fa0767d89c96a437378f4ccb89802dc7 (MD5) Previous issue date: 2013-07-10 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The main objective of the present work is the numerical simulation of an incompressible, isothermal turbulent flow inside a timber dry kiln using the commercial software ANSYS CFX®. The physical study aims at assessing the dry kiln aerodynamics by determining the velocity distribution inside the kiln for different operating conditions. In the study of the flow topology inside the dry kiln, the analysis is focused mainly on the evaluation of the influence of the (i) width of the inlet plenum and (ii) flow velocity at its entrance. The simulations show that the plenum width has a direct influence on the velocity distribution in the kiln. This parameter directly affects the location and size of the vortex generated just after the plenum entrance corner. Moreover, the variation of the inlet velocity imposes no significant differences in the flow topology inside the kiln. Finally, it is worth to emphasize that to significantly improve flow uniformity in the channels across the stack height it is necessary to find alternatives able to reduce or eliminate the vortex generated at the entrance of the inlet plenum . / O presente trabalho teve por objetivo principal a análise de um escoamento turbulento incompressível e isotérmico no interior de um secador de madeira utilizando uma metodologia numérica baseada no programa comercial ANSYS CFX®. O estudo físico realizado consistiu em avaliar a aerodinâmica do secador, a saber: determinar a distribuição de velocidades no interior do dispositivo em diferentes condições de operação. No estudo da topologia do escoamento no interior do secador de madeira, a análise foi focada, principalmente, na avaliação da influência dos seguintes parâmetros: (i) largura do canal vertical de entrada, plenum e (ii) velocidade do escoamento na entrada. De acordo com os resultados obtidos, a largura do plenum tem influência direta na distribuição de velocidades no interior do secador. Este parâmetro está diretamente relacionado à localização e tamanho do vórtice gerado após a quina de entrada. Por outro lado, a variação da velocidade de entrada não apresentou diferenças significativas na topologia do escoamento no interior do secador. Por fim, vale salientar que para se obter ganhos significativos na uniformidade do escoamento nos canais faz-se necessário encontrar alternativas que minimizem o vórtice gerado na quina de entrada do secador.

<p>   </p> <p>Biochar and charcoal cannot properly be discussed without understanding the diverse technologies available for their production. This is because approximately 70% of wood harvested worldwide is burned for energy and this, in addition to unstainable agricultural activities, has caused a massive increase in deforestation and contributed to climate change. Due to this, current global interventions are focused on promoting sustainable approaches through the expansion of agricultural technologies in countries where the deforestation rate keeps increasing due to overdependency on unsustainable and inefficient conversion technologies. It is therefore obvious that African regions cannot be left out when talking about the impact of global agriculture and charcoal production. Not only is 95% of all household energy used in Africa derived from burning wood in the form of charcoal and firewood, but sub-Saharan Africa regions also contribute 62% to global charcoal production. Since sustainability approaches are of global concern and must be understood from different perspectives and regions, this work analyzed sustainable agriculture and climate mitigation strategies using charcoal and biochar production as indicators. From a sustainability point of view, the study categorized this assessment into three chapters to help understand the preferences of local producers in relation to technologies used and the necessary actions or interventions needed for future improvements.</p> <p><br></p> <p>In the first chapter, 492 charcoal producers from Ghana were interviewed with semi-structured questionnaires to understand the demographics of charcoal producers, species used for charcoal, and how these producers intend to sustain the charcoal industry in terms of acquisition of wood resources/raw materials. This helped to analyze how the demographics of charcoal producers influence the charcoal production industry, characterize some wood species suitable and acceptable for sustainable charcoal production, and to recommend some necessary interventions toward sustainability.</p> <p><br></p> <p>In the second chapter, the heating characteristics of the most common indigenous species and exotic species identified in the first chapter were examined for their charcoal production properties (yield and calorific values) using the most common conversion technology available in the study area (earth mound). The heating/calorific values of these species were also determined using a ballistic bomb calorimeter. This also helped in examining the impact of the common charcoal production technologies on the qualities of charcoal produced and their corresponding impacts on the environment. Additionally, this chapter identified that most charcoal production species have longer rotation times with added values other than being used for charcoal. Furthermore, inappropriate conversion technologies minimize charcoal yield and quality; therefore, developing more efficient and affordable conversion kilns would increase charcoal production efficiency and improve the sustainable production of charcoal.</p> <p><br></p> <p>Based on the recommendation from chapter two, chapter three focused on building transferable skills and knowledge to help smallholder farmers and charcoal producers to fabricate cost-effective retorts/kilns for biochar and charcoal production. Through the process, we reviewed, selected, redesigned, and manufactured three common global conversion technologies and tested their potential for sustainable biochar and charcoal production using wood and crop stubbles (corn husk, corn cob, and sorghum residues). This helped in proposing best techniques and technologies suitable for biochar and charcoal production based on their production and use variables. It was therefore concluded that when farmers gain more knowledge and skills in manufacturing relevant and cheap technologies at their convenience, they could make the right subsequent choices towards sustainable agricultural practices.</p> <p>  </p>

Made available in DSpace on 2016-04-28T14:56:18Z (GMT). No. of bitstreams: 1 2008 - Kelysson de Freitas Amparo.pdf: 3210670 bytes, checksum: fc139c4d95da126bd1c41d4980ceb74a (MD5) Previous issue date: 2008-08-23 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / In this research were studied thirty trees of Eucalyptus saligna Smith wood, sampled in a twenty year-old plantation located in Serop?dica/RJ. Each tree supplied a log with 2.30 meters in length for the study of the sawn process and panels production ( PCLs ). The processing of the logs was made in the LPZ Madeiras and Artefatos Ltda sawmill - Pira?/RJ, being determined the revenue in sawnwood. Later on, the boards went by the process of artificial drying, with controlled conditions, in the Laboratory of Wood Drying, of the Forest Products Department, of the Forest Institute, of UFRuralRJ. In the qualitative evaluation, were determinate the defects indexes of the wood after drying. Smaller pieces were produced and were used in the glued panels production. The glued panels were produced from four treatments, for comparison among them, being these: simple panel with simple top connection (T1), simple panel with finger-joint connection (T2), double panel with simple top connection (T3), and double panel with finger-joint connection (T4). Were quantified the revenue of the conversion of the logs in sawnwood; the qualitative indexes of boards defects after the artificial drying; the revenue of the conversion of the boards in glued panels (being eliminated defects as cracks and severe torsion); and the resistance properties of PCLs through the shear, traction and static bending tests, following normative procedures of the document ABNT NBR 7190:1997 and ASTM D-1037. As practical example of the application of the eucalyptus glued panels was produced an experimental furniture (armchair), being discussed the problems and solutions found in the application of the studied material. / Neste trabalho foram avaliadas trinta ?rvores do g?nero Eucalyptus saligna Smith, amostradas em um talh?o de vinte anos de idade localizado no campus da Universidade Federal Rural do Rio de Janeiro, em Serop?dica/RJ. Cada ?rvore forneceu uma tora com 2,30 metros de comprimento cada uma, para o estudo do processo em escala piloto de obten??o de madeira serrada e pain?is colados lateralmente (PCLs). O processamento das toras foi efetuado na serraria LPZ Madeiras e Artefatos Ltda., em Pira?/RJ, determinando-se o rendimento em madeira serrada. Posteriormente, as t?buas passaram pelo processo de secagem artificial, em c?mara de secagem automatizada com condi??es controladas, no Laborat?rio de Secagem, do Departamento de Produtos Florestais, do Instituto de Florestas da UFRuralRJ. Na avalia??o qualitativa, foram avaliados os ?ndices de defeitos na madeira ap?s secagem. A seguir as t?buas foram levadas para o Laborat?rio de Usinagem e Beneficiamento da Madeira do DPF/IF/UFRuralRJ, onde foram resserradas, produzindo sarrafos, que foram utilizados na confec??o de pain?is colados lateralmente e de um m?vel (poltrona). Os pain?is colados lateralmente foram produzidos a partir de quatro tratamentos, para compara??o entre eles, sendo estes: painel simples com emendas de topo (T1), painel simples com emendas tipo finger-joint (T2), painel com dupla camada de sarrafos com emendas de topo (T3), e painel com dupla camada de sarrafos com emendas tipo finger-joint (T4). Foram quantificados o rendimento da convers?o das toras em madeira serrada; os ?ndices qualitativos de defeitos presentes nas t?buas ap?s a secagem artificial; o rendimento da convers?o da madeira serrada em pain?is colados lateralmente (eliminando-se defeitos como rachaduras, n?s soltos e empenamentos severos); e as propriedades de resist?ncia dos PCLs atrav?s dos ensaios de cisalhamento e tra??o, adaptados ao material e seguindo procedimentos normativos do documento ABNT NBR 7190:1997 e ensaios de flex?o orientados pelo documento normativo ASTM D-1037 (norma americana). Como exemplo pr?tico da aplica??o dos pain?is colados de eucalipto foi produzido um m?vel (poltrona), sendo discutidos e avaliados os problemas e solu??es encontrados na aplica??o do material estudado.

Denna studie handlar om pelletering som möjlig lönsam marginalaffär vid mindre sågverk/hyvlerier. Studien, vilken skett genom djupintervjuer på plats, omfattar fem olika mindre sågverk/hyvlerier i Småland. Verksamheterna är sinsemellan på många sätt olika men har samtliga satsat på pelletering av ekonomiska skäl och av miljöskäl. Studien visar att pelletering är lönsam men också att det krävs vissa förutsättningar för att långsiktigt nå denna lönsamhet. Den viktigaste är långsiktig tillgång till råvara i form av torrt spån men det krävs även ett genuint intresse och en stor kunskap inom såväl teknik som trä för den som skall pelletera Detta beror på att produktionsprocessen är mycket komplicerad och även beroende av en del yttre omständigheter som t.ex. fukt, kyla och torka. Eftersom komplexiteten, och därmed den initiala personella insatsen är stor, bör man också uppnå vissa minimikvantiteter i produktionen. Studien visar också att det även krävs ett antal övriga element för att pelleteringen skall uppvisa den lönsamhet som en hastig förkalkyl ger vid handen. Klarar man att leva upp till de flesta av dessa finns det goda förutsättningar att pelletering över en konjunkturcykel kan medverka till att förbättra lönsamheten för den typ av mindre anläggningar som studerats. / This study is about pelleting as a possible profitable marginal business for minor saw-mills and planing mills. It has been carried out through in depth interviews of five different minor saw-mills and planing mills in Småland. These businesses are different themselves but all of them have invested in pelleting for financial and environmental reasons. The study shows that pelleting is profitable but also that a number of conditions must be fulfilled to reach profitability in the long run. The most important success factor is long-term access to raw material (dry chip) but the production process also demands a high interest and knowledge in wood and processing technology. This is due to the fact that the process is very complex and also depending on external circumstances like humidity, coldness and dryness. Due to this complexity and that the demand of manpower is rather high one should aim for producing at least a certain minimum quantity. The study also shows that there are a couple of other factors that are needed to be fulfilled to reach the profitability that the pre-calculation indicates. If most of these conditions are fulfilled there are very good possibilities that pelleting over a business cycle can contribute to an improved profitability for the type of businesses that have been studied.

<p>Denna studie handlar om pelletering som möjlig lönsam marginalaffär vid mindre sågverk/hyvlerier. Studien, vilken skett genom djupintervjuer på plats, omfattar fem olika mindre sågverk/hyvlerier i Småland. Verksamheterna är sinsemellan på många sätt olika men har samtliga satsat på pelletering av ekonomiska skäl och av miljöskäl.</p><p>Studien visar att pelletering är lönsam men också att det krävs vissa förutsättningar för att långsiktigt nå denna lönsamhet. Den viktigaste är långsiktig tillgång till råvara i form av torrt spån men det krävs även ett genuint intresse och en stor kunskap inom såväl teknik som trä för den som skall pelletera Detta beror på att produktionsprocessen är mycket komplicerad och även beroende av en del yttre omständigheter som t.ex. fukt, kyla och torka. Eftersom komplexiteten, och därmed den initiala personella insatsen är stor, bör man också uppnå vissa minimikvantiteter i produktionen. Studien visar också att det även krävs ett antal övriga element för att pelleteringen skall uppvisa den lönsamhet som en hastig förkalkyl ger vid handen.</p><p>Klarar man att leva upp till de flesta av dessa finns det goda förutsättningar att pelletering över en konjunkturcykel kan medverka till att förbättra lönsamheten för den typ av mindre anläggningar som studerats.</p> / <p>This study is about pelleting as a possible profitable marginal business for minor saw-mills and planing mills. It has been carried out through in depth interviews of five different minor saw-mills and planing mills in Småland. These businesses are different themselves but all of them have invested in pelleting for financial and environmental reasons.</p><p>The study shows that pelleting is profitable but also that a number of conditions must be fulfilled to reach profitability in the long run. The most important success factor is long-term access to raw material (dry chip) but the production process also demands a high interest and knowledge in wood and processing technology. This is due to the fact that the process is very complex and also depending on external circumstances like humidity, coldness and dryness. Due to this complexity and that the demand of manpower is rather high one should aim for producing at least a certain minimum quantity.</p><p>The study also shows that there are a couple of other factors that are needed to be fulfilled to reach the profitability that the pre-calculation indicates.</p><p>If most of these conditions are fulfilled there are very good possibilities that pelleting over a business cycle can contribute to an improved profitability for the type of businesses that have been studied.</p>

Thesis (MEng)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: For wood manufacturers around the world, the single biggest cost factor is known to be its raw material. Thus maximum utilisation, specifically volume recovery of this raw material, is of key importance for the industry. The wood products industry consists of several interrelated manufacturing steps for converting trees into logs and logs into finished lumber. At most primary and secondary wood processors the different manufacturing steps are optimised in isolation or based on operator experience. This can lead to suboptimal decisions and a substantial waste of raw material. The objective of this study was to determine the optimal machine settings for two interrelated operations, namely the sawing and ripping operations which have traditionally been optimised individually. A model, having two decision variables, was developed which aims to satisfy market demand at a minimal cost. The first decision was how to saw the log supply into different thicknesses by choosing specific sawing patterns. The second was to decide on a rip saw’s settings, namely part priority values, which determines how the products from the primary sawing operation are ripped into products of a certain thickness and width. The techniques used to determine the machine settings included static simulation with the SIMSAW software to represent the sawing operation and mixed integer programming to model the ripping operation. A metaheuristic, namely the Population Based Incremental Learning algorithm, was the link between the two operations and determined the optimal settings for the combined process. The model’s objective function was formulated to minimise the cost of production. This cost included the raw material waste cost and the over or under production cost. The over production cost was estimated to include the stock keeping costs. The under production cost was estimated as the buy-in cost of purchasing the under supplied products from another wood supplier. The model performed well against current decision software available in South Africa, namely the Sawmill Production Planning System package, which combines simulation (SIMSAW) and mixed integer programming techniques to maximise profit. The model added further value in modelling and determining the ripping priority settings in addition to the primary sawing patterns. / AFRIKAANSE OPSOMMING: Die grootste enkele koste vir houtprodukvervaardigers wêreldwyd is dié van hulle roumateriaal. Die maksimale gebruik van rou materiaal, of volume herwinning, is dus van primêre belang vir hierdie industrie. Die vervaardigingsproses in die houtprodukte-industrie bestaan uit ‘n verskeidenheid interafhanklike stappe om bome na stompe te verwerk en stompe na eindprodukte. By meeste primêre -en sekondêre houtvervaardigers word die verskillende vervaardigingsstappe in isolasie ge-optimeer. Hierdie praktyk lei tot sub-optimale besluite en ‘n vermorsing van roumateriale. Die doelwit van hierdie studie was om die optimale masjienverstellings vir twee interafhanklike prosesse, die primêre -en kloofsaag prosesse, te bepaal. Tradisioneel word hierdie twee prosesse individueel optimeer. ‘n Model met twee besluitnemingsveranderlikes is ontwikkel wat poog om die markaanvraag te bevredig teen ‘n minimum koste. Die eerste besluit was watter saagpatroon gekies moet word om die stompe in die regte dikte produkte te saag. Die tweede besluit was wat die kloofsaagstellings, ook bekend as prioriteitswaardes, moet wees sodat die regte wydte produkte gesaag word. Die tegnieke wat gebruik is sluit statiese simulasie met SIMSAW sagteware in om die primêre saagproses te modelleer en gemengde heelgetalprogammering (“mixed integer programming”) om die kloofsaagproses te modelleer. ‘n Metaheuristiek genaamd die “Population Based Incremental Learning” algoritme,was die skakel tussen die twee operasies om die optimale masjienstellings vir die proses te bepaal. Die model se doelfunksie was geformuleer om die koste van produksie te minimeer. Hierdie koste sluit die roumateriaal afvalkoste en die kostes van oor -en onderproduksie in. Die oorproduksiekoste was ‘n skatting van die voorraadkostes. Die onderproduksiekoste was ‘n skatting van die koste om voorraad van ‘n ander verskaffer aan te koop. Die model het goed opgeweeg teen die beskikbare besluitnemingssagteware in Suid Afrika, die “Sawmill Production Planning System”, wat ‘n kombinasie van SIMSAW en ‘n gemengde heelgetalprogrammeringstegniek is. Die model het verder waarde toegevoeg deur die kloofsaag se prioriteitswaardes te modelleer saam met die primêre saagpatrone.