Dissertations / Theses on the topic 'Wood production industry'

L'objectif principal de cette thèse est d'étudier le problème de planification de la production dans le contexte d'une demande incertaine, d’un niveau de service variable et d’approvisionnements incontrôlables dans une usine de seconde transformation du bois. Les activités de planification et de contrôle de production sont des tâches intrinsèquement complexes et difficiles pour les entreprises de seconde transformation du bois. La complexité vient de certaines caractéristiques intrinsèques de cette industrie, comme la co-production, les procédés alternatifs divergents, les systèmes de production sur commande (make-to-order), des temps de setup variables et une offre incontrôlable. La première partie de cette thèse propose une plate-forme d'optimisation/simulation permettant de prendre des décisions concernant le choix d'une politique de planification de la production, pour traiter rapidement les demandes incertaines, tout en tenant compte des caractéristiques complexes de l'industrie de la seconde transformation du bois. À cet effet, une stratégie de re-planification périodique basée sur un horizon roulant est utilisée et validée par un modèle de simulation utilisant des données réelles provenant d'un partenaire industriel. Dans la deuxième partie de cette thèse, une méthode de gestion des stocks de sécurité dynamique est proposée afin de mieux gérer le niveau de service, qui est contraint par une capacité de production limitée et à la complexité de la gestion des temps de mise en course. Nous avons ainsi développé une approche de re-planification périodique à deux phases, dans laquelle des capacités non-utilisées (dans la première phase) sont attribuées (dans la seconde phase) afin de produire certains produits jugés importants, augmentant ainsi la capacité du système à atteindre le niveau de stock de sécurité. Enfin, dans la troisième partie de la thèse, nous étudions l’impact d’un approvisionnement incontrôlable sur la planification de la production. Différents scénarios d'approvisionnement servent à identifier les seuils critiques dans les variations de l’offre. Le cadre proposé permet aux gestionnaires de comprendre l'impact de politiques d'approvisionnement proposées pour faire face aux incertitudes. Les résultats obtenus à travers les études de cas considérés montrent que les nouvelles approches proposées dans cette thèse constituent des outils pratiques et efficaces pour la planification de production du bois.
The main objective of this thesis is to investigate the production planning problem in the context of uncertain demand, variable service level, and uncontrollable supply in a wood remanufacturing mill. Production planning and control activities are complex and represent difficult tasks for wood remanufacturers. The complexity comes from inherent characteristics of the industry such as divergent co-production, alternative processes, make-to-order, short customer lead times, variable setup time, and uncontrollable supply. The first part of this thesis proposes an optimization/simulation platform to make decisions about the selection of a production planning policy to deal swiftly with uncertain demands, under the complex characteristics of the wood remanufacturing industry. For this purpose, a periodic re-planning strategy based on a rolling horizon was used and validated through a simulation model using real data from an industrial partner. The computational results highlighted the significance of using the re-planning model as a practical tool for production planning under unstable demands. In the second part, a dynamic safety stock method was proposed to better manage service level, which was threatened by issues related to limited production capacity and the complexity of setup time. We developed a two-phase periodic re-planning approach whereby idle capacities were allocated to produce more important products thus increasing the realization of safety stock level. Numerical results indicated that the solution of the two-phase method was superior to the initial method in terms of backorder level as well as inventory level. Finally, we studied the impact of uncontrollable supply on demand-driven wood remanufacturing production planning through an optimization and simulation framework. Different supply scenarios were used to identify the safety threshold of supply changes. The proposed framework provided managers with a novel advanced planning approach that allowed understanding the impact of supply policies to deal with uncertainties. In general, the wood products industry offers a rich environment for dealing with uncertainties for which the literature fails to provide efficient solutions. Regarding the results that were obtained through the case studies, we believe that approaches proposed in this thesis can be considered as novel and practical tools for wood remanufacturing production planning.

Swedish wood product industry contributes significantly to the economy of the country. This industry adds more value to the sawn timber produced in order to manufacture different wooden products. Companies in Swedish wood product industry are presently seen as underdeveloped in terms of investments and developments in automation technologies. Automation technologies are seen by companies as a solution for improving productivity, product quality, manufacturing cost reduction and ultimately improving competitiveness. This has driven competing companies to pursue automation technologies that improve manufacturing processes. Literature in the Wood product industry field shows that there is need for extended automation technologies. The wood product industry has high degree of handcraft; for instance, some Swedish wood product manufacturers still have an essentially manual manufacturing process. This study seeks to understand the role of automation in the Swedish wood product industry and mainly focuses on the factors that drive and restrain companies in this industry to adopt and use automation technologies. An abductive research approach was applied, consisting of a literature review and multiple empirical case studies. The literature review was conducted to provide theoretical background on the general view of automation and the factors that affect adoption of new technologies in companies. The case studies were performed in collaboration with four wood product manufacturers within different business areas in order to analyse and compare similarities and differences in the factors that drive and restrain adoption of automation technologies. The findings imply that companies in the Swedish wood product industry face different factors that drive and restrain them from adopting automation technologies. The factors are both internal and external to the companies. Among the noticeable ones are the high product variety, lack of automation strategies, heterogeneous material property of wood, low competence levels regarding automation technologies, varying demands from the customers, and relationship with the suppliers of automation technologies. Regardles of the restraining factors faced by companies in the Swedish wood product industry, there is a great opportunity to improve their production systems in terms of automation technologies. There is now a growing treand in these companies to prioritise automation technologies as a competitive factor. This study contributes to the knowledge regarding the factors that drive and restrain the adoption of automation technologies and how companies could deal with such factors in the Swedish wood product industry.

Skanska, Sweden’s leading project development and construction groups, is increasingly striving for innovative solutions to reduce the carbon footprint of its operations and close the loop on waste materials. The company has expressed interest in investing in a pyrolysis plant in the Stockholm region to produce biochar out of wood waste from construction sites. Biochar, a charcoal-like substance, is produced through thermochemical decomposition of biomass. Recently recognized as a negative emissions technology thanks to its ability to act as a carbon sink, and with its many properties and applications, biochar has in recent years become an increasingly valued product on the Nordic market. However, the magnitude with which biochar production mitigates climate change depends on a number of parameters. The present thesis seeks to assess the potential of biochar production at Skanska and use for urban soils to reduce the company’s GHG emissions, and puts results in perspective with Skanska’s sustainability targets. Using the GHG Protocol for Project Accounting, and through a life-cycle perspective, the thesis examines whether biochar production results in a higher climate gain compared to the continuation of current activities, i.e. the treatment of wood waste through incineration for energy recovery. The results show that reductions in emissions depend on a number of factors including biochar stability, biochar yield, the availability of excess heat from the pyrolysis process and its use for district heating, and most importantly, the type of fuel substituted by waste wood for energy production. Ultimately, the quality, quantity, and geographic distribution of wood waste produced by Skanska determines the viability of this project, and this information should be carefully compiled by the company.
Skanska AB, Sveriges ledande bygg- och projektutvecklingsföretag, strävar alltmer efter innovativa lösningar för att minska koldioxidavtrycket i sin verksamhet och sluta cirkeln för avfallsmaterial. Företaget har uttryckt ett intresse att investera i en pyrolysanläggning i Stockholmsregionen för att producera biokol av träavfall från byggarbetsplatser. Biokol produceras genom termokemisk sönderdelning av biomassa och blev nyligen erkänd som en negativ utsläppsteknologi tack vare sin förmåga att fungera som kolsänka. Med sina många användningsområden och varierande egenskaper har biokol under senare år blivit en allt högre värderad produkt på den nordiska marknaden. Dock spelar flera faktorer roll när möjligheterna för biokolsproduktion att reducera klimatförändringarna ska bedömas. Det här examensarbetet syftar till att utvärdera potentialen för biokolsproduktion inom Skanska och användandet av biokol i urbana jordar för att minska företagets växthusgasutsläpp, samt sätta resultaten i perspektiv med Skanskas hållbarhetsmål. Genom att använda GHG-protokollet för projektredovisning, samt ur ett livscykelperspektiv, undersöker examensarbetet huruvida biokolproduktionen resulterar i en högre klimatnytta jämfört med den nuvarande verksamheten, det vill säga genom förbränning av träavfall för energiåtervinning. Resultaten visar att utsläppsminskningar beror på ett antal faktorer, inklusive biokolets stabilitet, produktionsutbyte, tillgång till överskottsvärme från pyrolysprocessen för användning i fjärrvärmenätet, samt viktigast av allt, vilken typ av bränsle som ersätts av träavfall för energiproduktion. I slutändan är det kvaliteten, kvantiteten samt geografisk tillgång till producerat träavfall för biokolsproduktion som avgör hur väl detta projekt kan genomföras, och denna information bör noggrant sammanställas av Skanska.

Particleboard was invented to increase the utilization of wood and it soon became an important core material for furniture production. Nowadays, other industries such as the pulp and papermaking industry and the thermal energy recovery industry claim the same type of raw material. This leads to increasing competition and higher prices than in the past when that kind of wood raw material was widely available and of low price. The particleboard-producing industry is therefore seeking opportunities to reduce the competition and ensure the future supply of lignocellulosic raw material for their products. The purpose of the work summarised in this thesis was to investigate the strategic supply of lignocellulosic raw materials for particleboard production and to evaluate alternatives for the supply of lignocellulosic raw material for particleboard production. To encompass the complex field of strategic raw material supply, several publications have considered different stages along the supply chain. These papers range from empirical studies to practical tests on a laboratory scale. In this thesis, some of the papers are linked together, building the base for the overall results. The results show that the task of increasing the supply of lignocellulosic raw material as primary raw material source is limited by several factors, but that improved product design coupled with a suitable recycling concept can greatly increase the availability of lignocellulosic raw material as a secondary source. Alternatively, the use of non-wood plants might be an opportunity to substitute wood as raw material but there are still some problems relating to the particle properties which must be overcome first.

There is a rapid change in the current market that requires more customisation and higher quality for a lower price. For SMEs, it is a challenge to compete and develop the production system in this increasingly competitive environment. One way to increase the competitive advantages is to investigate the possibilities to involve Lean tools such as VSM. The purpose of the VSM design is to get a quick holistic view of the production system to find value-added and non-value-added activities and improve the production system. A VSM is, however, not widely explored in a production system with high flexibility and a high number of variants in a functional layout. It has been discovered that there is a research gap in the literature, and some researchers proclaim that there is none or a negative correlation between VSM and flexible production. Therefore, there is a need to further explore these concepts together at a case company with these pa-rameters.The methodological approach is a single case study at a case company. The research focuses on investigating how the VSM can be applicable in a production system with high flexibility on a functional layout facility. The study will focus on hard aspects such as the VSM itself and soft aspects such as Lean concepts, Change Management, and employee’s behaviour and reactions. The reason is that enterprises need to investigate parameters and employee behaviour since a production system with high flexibility on a functional layout often perceives as a complex system. Therefore a conceptual model has been developed to facilitate the adoption of this kind of production system. The created conceptual model is based on the findings from the case company and theories from the literature studies. The methods that supported the data collection in the case are interviews with the production personnel and personnel from the management de-partment, observations, VSM and a literature review.

The thesis deals with possibilities of using of mobile band saws. An economic analysis of band saw utilization for woodworking was carried out. Further the work evaluates and analyses the technological string of lumber production in a selected area. In the first part there is a study of current state of technological string of saw timber production. The second chapter deals with the evaluation of state in consideration of woodworking in relation to selected location of production facilities. The third part is focused on evaluation of possibilities of mobile band saw utilization that is carried out on Husqvarna SMB - 70. The fourth section describes technological variations and tries to determine criteria for choosing of the best variant. It details opportunities of a small - grower that tries to find the most suitable variant by selling a wood, so as it brings the maximum profit. The work deals with various possibilities of timber production in which the band saw is included. Technical parameters of particular saws are described here. And by means of economic parameters the most suitable technology for sawn wood production is determined. The goal of this thesis is to choose a suitable technology for timber production based on economic analysis and with regard to conditions of the processing plant.

The progression of wood processing in Swedish saw mills is growing in a rapid pace which pushes internal resources to the limit. This calls for new and innovative ideas to further the capacity of the production to satisfy both requirements as well as demands. Logistics is a key factor in these processes which can both hide problems as well as solutions that could benefit production.   The objective of the study is to research the current timber yard model as it doesn’t suffice the demand, and instead present alternative ideas that will. The methods to do so are a collection of interviews, literary researches and a case study. Alternative models are generally presented in regards to volume capacity but also machine capacity, time and economic factors.   The results show the inefficiency of the current model with insufficient volume capacity of logs, and where unnecessary hauling between two yards have costly outcomes. Suggested model increases the total yard volume from 15 000 m³ to about 25 176 m³, but where hauling and transporting costs still are imminent due to the geographical position of the industry. The model is designed to decrease hauling distances along with lower fuel usage and ultimately effects on the environment.   Increasing the volume of the timber yard is carried out by taking advantage of unutilized areas as well as by a compromise of areas that are today used for other processes.   Lastly, the recommendations presented to the company are to analyze the results and research questions of the study and from there see to what actions are to be made. Developing the concepts of presented model along with the other suggestions and conclusions that follow.
Framfarten av vidareförädling av trä i svenska sågverk är mycket stor vilket sätter stor press på interna resurser. Detta efterfrågar nya och innovativa idéer for att utveckla produktionens kapacitet för att ha möjligheterna att både tillfredsställa krav och efterfråga. Logistik är en nyckelfaktor i dessa processer, vilket både kan gömma problem men även lösningar för produktionens fördel.   Målet för studien är att utforska den nuvarande timmerplanen då den inte räcker till för den efterfrågan som eftersträvas och istället presentera alternativa idéer som gör det. Metoderna som används för det är en samling av intervjuer, litterära undersökningar och fallstudier. Alternativa modeller presenteras framför allt sätt till volymkapacitet men även maskinkapacitet, tid och ekonomiska faktorer.   Resultaten visar en ineffektivitet i den nuvarande modellen vilket har en otillräcklig volymkapacitet för stock, där onödigt fraktande bidrar med dyra resultat. Modellen som föreslås ökar den nuvarande totala kapaciteten från cirka 15 000 m³ till 25 176 m³, men där fraktning och transporter fortfarande är ofrånkomligt på grund av den geografiska positionen industrin har. Modellen är utformad för att minska transportavstånd samt bränsleförbrukning och därmed även negativa effekter på miljön.   Ökningen av volym på timmer planen görs genom att använda oanvända områden samt genom kompromisser med områden som idag har ett annat användningsområde för andra delprocesser. De presenterade modeller ser till de förhållande av studien i relation till de satta ambitioner och begränsningar.   Slutligen, de rekommendationer som framförts till företaget är att analysera de tankar och idéer från studien och därifrån se vilka handlingar som ska tas. Vidareutveckla de koncept av presenterade modeller i samband med de förslag och slutsatser som följer.

Increasing competition and technological improvements have created new challenges for the firms. In Turkey, low-tech small and medium scale furniture industry does not seem to be well equipped to compete in this respect due to their weak economic and cultural capital. Necessity of innovative and distinguishing design-led policies has already arisen for improving the position of the low-tech small and medium scale furniture producers. However, to generate effective policies for them, it is essential to understand the design process and production domain related to cultural factors which affect the position of design and the designer. Within this perspective, this thesis examines the position of design and the designer within the product development process in eight cases of small and medium scale furniture companies based on the data gathered from, firstly, in-depth interviews with the owners, and secondly, product development stories narrated by the owner, the designers and head of the production departments of the companies.

Contract furniture which is manufactured depending on the client&
#8217
s design or specification requirements on a contract basis is executed in small and medium sized furniture companies in Turkey. This one-of-a-kind production organization provides component manufacturing opportunity to furniture SMEs via subcontracting. In this study, the use of design consultancy is investigated to understand how it should be used in the current organization, in order to implement this production system efficiently. This study also examines contract furniture production to have foresight for the development of furniture SMEs in Turkey. In a literature review, the generic context of contracting activities in relation to design activity is investigated. Methods of design consultancy use in product development processes are searched. Design consultancy in construction industry is examined Data about design and production capabilities of Turkish furniture SMEs is collected. Production planning processes of a contract furniture company was investigated and discussed in a case study. These two groups of data were compared in order to drive conclusions.

La planification tactique des opérations forêt-usines est centrée sur trois éléments principaux : la récolte, le transport et la transformation du bois. La planification de cette chaine d’approvisionnement est très complexe. Il existe déjà des outils pour faciliter la décision de décideur tels que FPInterface et Optitek, tous deux développés par FPInnovations. Cette mémoire vise à développer un module d’optimisation qui est connecté aux utiles de simulation. LogiOpt est constituée d'un modèle mathématique. Le modèle développé vise l’optimisation de la chaîne d’approvisionnement entre la forêt et l’usine en concentrant les efforts sur les activités que l’entreprise planifie conjointement avec son entrepreneur d’opérations forestières principal. Grâce à ces solutions de logiciels de simulation et de notre modèle mathématique, nous combinons à la fois dans notre cadre récolte, le transport, l'allocation des bois et des opérations de production. Pour tester notre model mathématique, nous avons utilisé les données d’une année d’exploitation à une entreprise québécoise œuvrant dans le milieu forestier. Nous avons comparé nos résultats avec un plan tactique manuel « simulé ». De ce fait, nous avons constaté que LogiOpt effectue une meilleure allocation de la matière première en allant récolter dans moins de blocs de récolte tout en utilisant des bois ayant un meilleur rendement en usine. Conséquemment, on produit plus de produits finis en usine tout en utilisant la même quantité de bois qu’un plan tactique plus traditionnel.
Forest and sawmills tactical planning is based on three main elements: wood harvesting, wood transportation and wood transformation. Planning the whole supply chain, is quite complex. Tools have been built to help manager in his decision process, for example FPInterface and Optitek, which were developed by FPInnovations. The aim of this thesis is to develop an optimization module, LogiOpt, which will be integrated to simulation tools. LogiOpt is made of a mathematical model. The developed model aims at optimizing the supply chain between the forest and the mills. Using simulation software solutions and our mathematical model, we combine at the same time in our framework harvesting, transportation, wood allocation and production operations. To test our mathematical model, we used data obtained from one business year of a Quebec based wood manufacturer. We compared our results with a manual simulated tactical plan. In this regard, we observed that LogiOpt performs better in wood allocation between sawmills, harvesting in less harvesting while using wood with better output. We then end up producing more finished products at sawmills using the same wood quantity as a traditional tactical plan.

Augmenter la part de marché du bois dans la construction non résidentielle est un objectif important dans les pays où les produits forestiers et de bois d'ingénierie jouent un rôle fondamental. Afin de faciliter la production de structures en bois innovantes, il est nécessaire de mettre sur pied des procédures de réingénierie en termes d’analyse de marché et d’amélioration de la productivité. L'objectif principal de cette thèse est de faciliter la production de bois d'ingénierie (produits en lamellé-collé) destiné à être utilisé dans des structures en bois innovantes telles que les résilles en bois. Pour atteindre ce but, trois objectifs spécifiques sont définis. Le premier objectif est de déterminer les phases de production et les opportunités de marché pour la production de résilles en bois. À cet égard, une revue de la littérature académique et de la littérature grise a été réalisée, et vingt échantillons ont été identifiés et analysés à l'aide de diagrammes de processus et de catégorisations. Les résultats ont montré qu’une structure en résille de bois est utilisée dans l'industrie de la construction en Europe et qu'elle est moins connue en Amérique du Nord, ce qui offre une opportunité de marché pour sa production et sa construction. La catégorisation des échantillons étudiés dans les petites, moyennes et grandes structures et l'identification des acteurs pour chaque catégorie fournissent une vue d'ensemble pour les entreprises qui envisagent la production de cette structure. Le deuxième objectif de cette thèse est de fournir un modèle de simulation pour la production de bois lamellé-collé dans de petites usines et le processus d'application de techniques Lean pour apporter des améliorations. À cet égard, le système de production d’une entreprise québécoise a été analysé et un modèle de simulation créé. Afin d'éliminer chaque source de gaspillage, un outil Lean a été suggéré en fonction de la réalité du système à l’étude. Les résultats ont montré une amélioration notable du temps d’attente et de cycle suite à l’utilisation de techniques issues du Lean. Ils ont également contribué à souligner qu’une élimination du gaspillage limitée à 50% pouvait améliorer la considérablement la productivité pour les petites entreprises et s’avérer un premier pas important dans l’implantation du Lean. Le troisième objectif est de fournir un outil de planification et d'ordonnancement de la production dans un contexte de production multi-projets d’ingénierie sur commande (Engineer-to-Order) de bois lamellé-collé. À cet égard, des modèles d'optimisation ont été créés. Le premier modèle (modèle 1) concerne la minimisation du coût de production total, tandis que le modèle 2 vise la minimisation de la durée totale des projets. Le modèle 3 cherche plutôt à réduire le temps de mise en route sur la presse, le poste goulot du système de production considéré. Le modèle 4 intègre les trois objectifs de réduction des coûts, de durée et de temps de mise en route. Deux scénarios d’ajout de projets de grande et de moyenne envergure ont été conçus et testés. Le test des scénarios démontre qu'il y a une capacité suffisante pour l’ajout d’un projet de grande envergure ou de neuf projets de taille moyenne sans recourir à la sous-traitance. L'ajout d'un projet de grande envergure est plus sensible à la période d'insertion, pouvant exiger du temps supplémentaire selon la date de début du projet. Les travaux de cette thèse permettent donc de fournir des outils d'aide à la décision pour les entreprises œuvrant dans un milieu d'ingénierie sur commande afin d'améliorer leur productivité et la standardisation de leurs processus.
Increasing the share of wood in non-residential construction is an important goal in countries with major forest and engineered wood products. In order to facilitate the production of innovative timber structures, procedures should be re-engineered in terms of market analysis and productivity improvement. The main objective of this thesis is to facilitate the production of engineered wood to be used in innovative wood structures such as timber gridshell. To achieve this goal, three specific objectives are defined. The first objective is to determine production phases and market opportunities for the production of timber gridshell. In this regard, a review of the academic and grey literature was conducted, and twenty samples were identified and analysed by making process charts and categorisations. The results showed that gridshell is used in the construction industry in Europe and is less recognised in North America, which provides a market opportunity for its production and construction. The categorisation of studied samples in small, medium and large structures provides an overview for the companies who consider the production of this structure. The second objective of this thesis is to provide a simulation model for the production of glued laminated timber in small factories and the process of applying lean techniques to make improvements. In this regard, the production system of a Small and medium-sized enterprise (SME) was analysed, and a simulation model was created. In order to eliminate each source of waste, a lean tool was suggested according to the reality of the system under investigation. The lean methods were applied in the simulation model to analyse the potential improvements. Results showed a noticeable improvement in waiting and cycle time. It also showed that applying even 50% elimination of the wastes is also a considerable solution to improve productivity as a beginning step for SMEs. The third objective is to provide a production planning and scheduling tool in the context of multi-project engineer-to-order production of glued laminated timber. In this regard, optimisation models were created. The first model (model 1) concerns the minimisation of total production cost while model 2 aims to minimise projects’ makespan. Model 3 introduces the set-up time reduction and model 4 integrates the three objectives of minimising cost, makespan and set-up time. Two scenarios of adding complex and medium projects were designed and tested. Testing the scenarios showed that there is enough capacity for adding one complex project or nine medium projects without the need to outsource. Adding a complex project is more sensitive to the insertion period and beginning the project in different weeks leads to different results in terms of the overtime requirement. As a result, the work of this thesis provides decision support tools for engineer-to-order environments which could help SMEs to improve their productivity and standardisation.
Résumé en espagnol

The research was conducted in the Hewu area situated between Queenstown (20 km) and Whittlesea (15km) in the Eastern Cape Province of South Africa. In this area communal farming is practiced. Livestock and livestock products (wool) are the main sources of income. The farmers are mainly farming with Merino and Döhne Merino sheep. The lack of management systems (production, reproduction and management) for communal farmers resulted into ineffective communal farming defining the research problem. The research objectives set were: • To establish production norms for wool sheep. • To establish reproduction norms for wool sheep. • To establish effective management practices for wool sheep farmers. • To examine key constraints of wool sheep farmers. The farmers shear their sheep every 12 months usually in October of every year. The average wool production per sheep is 2.17kg. The clip averages a fineness of 19.1-20 micron. That is far below the wool production of the commercial farmers of the Eastern Cape who are producing between 4kg to 5kg per sheep at an average growing period of 12 months. The lack of proper fencing and camps causes major reproduction problems. The lambing percentage of the ewes is 94.85 percent. The weaning percentage referring to the reproductive efficiency of the mated ewes is only 17.24 percent. The survival rate of the lambs born alive is only 18.18 percent. Reproduction is the biggest problem of communal farms. Effective livestock- and grazing management systems for communal areas are essential for the successful development of farmers on communal grazing areas. Unfortunately the Hewu farmers still have many problems effecting their wool production and the production of lambs.

The thesis considers a stabilization of temperature of a wood fiber during production of medium close fibre boards MDF in a wood-processing industry. The original purpose to solve energetic optimalization of a kiln dryer has become a serious problem. It turned out that production suffers with a big heat loss which results in big heat loss gained during a kiln drying. Primary aim of this thesis is an examination of a cooling effect of environment on chosen parts of a production line and suggestion of acceptable proceeding to minimize heat loss and to rise temperature of the wood fiber to required temperature. Solution is aimed on the section of a production line between drying equipment and press. First part of the thesis introduces technology of production of fibre boards, introduction to heat transfer problems and also basics of computer modeling of heat flow and transfer using CFD simulation. The next part includes an evaluation of the heat loss of chosen parts of the production line in a current working condition and its comparison with computer simulations. Verification of accuracy of the results while using both approaches to solution is a first step to the improvement of the current situation. It is possible to use the verified calculation model for the following solution of effects on convective and radiation heating of a wood fiber layer. An important factor in the last period of a calculation is a real temperature of the fiber board-mat at the entrance to a press. The higher entering temperature in a set temperature range is reached, the lower time needed for pressing will be and simultaneously the whole industrial process will be cut short. The solution of a problem leads to an achievement of an energy saving and should become a solid basis from which it would be possible to evaluate an improvement of production of MDF boards. The conclusion of the thesis includes an analysis of findings which refers to a heating of wood fiber and it’s effectiveness for a practical use.

Materialet i rapporten är 10% av det totala materialet som presenterats till SCA, de viktigaste resultaten redovisas i rapporten. Vid SCA:s sågverk Rundvik i Nordmaling finns en automatiserad emballeringsmaskin. Ingen bra anvisning för bruk/drift och underhåll för maskinen finns, vilket har gjort det svårt för personalen att hantera den. Syftet med detta arbete var att kartlägga maskinens delar, funktioner och därefter framta en bruksanvisning. Detta gjordes genom att först kartlägga placeringen av maskinens axlar samt dess funktioner. Därefter intervjuades personalen på hyvleriet för att reda ut svårigheter och problem med maskinen. En problemlösning som löser de mest förekommande felen har framställts. En underhållsplan har tagits fram för att underlätta underhåll av maskinen. En offert på en programuppdatering har skickats till maskinprogrammerare. En offert gällande en säkerhetsanordning till maskinen har skickats till maskintillverkare. Resultatet är en fullt användbar, enkelt läsbar bruksanvisning. Syftet har inte fullföljts helt då operatör inte hunnit testa instruktionerna.
The material in the report is 10% of the total material presented to SCA, the most important results are reported here. At SCA's sawmill Rundvik in Nordmaling, there is an automated packaging machine. There is no good user manual for use/operation and maintenance of the machine, which has made it difficult for the staff to handle it. The purpose of this work has been to map the machine's parts, functions and then produce a user manual. This was done by first mapping the location of the machine's axles and its functions. The staff at the planer were then interviewed to sort out difficulties and problems with the machine. A problem solution that solves the most common errors has been produced. A maintenance plan has been developed to facilitate maintenance of the machine. A quote for a software update has been sent to the machine programmer. A quote regarding a safety device for the machine has been sent to the machine manufacturer. The result is a fully usable, easy-to-read user manual. The purpose has not been fully fulfilled as the operator has not had time to test the instructions.

Thesis (MBA)--Stellenbosch University, 2000.
Page 62 of digitised copy may appear cut off and pages 63-64 missing due to the condition of the original hard copy.
ENGLISH ABSTRACT: Modern management planning and control systems dates back to World War I in 1915. The development of the bar chart during that time by Henry L. Gantt was a drastic improvement on previous methods. The size, complexity and risks associated with modern technical sophisticated projects has required the development of new methods. This led to the development of the critical path method which was developed in the United States of America during the period 1956 to 1958. Since then various methods have been developed with the aim of meeting special requirements. The extent of achieving success for construction projects, varies drastically according to the application of project scheduling techniques. This statement is confirmed by various studies conducted in an attempt to analyse the scheduling and controlling of construction projects, but due to the complexity of the time-cost-problem which is coupled to construction projects, problems are still being experienced with the successful or timeous completion of construction projects. Regarding the problems being experienced to complete construction projects timeously, this investigation will attempt to find underlying reasons for these problems and to determine proper solutions. This investigation will therefore focus on the reasons why deviations from the schedules occur so frequently, and what can possibly be done to prevent it. From the aforementioned the following can be concluded: An investigation into the reasons why construction projects making use of municipal services are often completed late, although it was scheduled with the help of network techniques. The procedure that was followed for the investigation was firstly the formulation of goals and study area. Thereafter a literature study was done that covered the following aspects of the study: • background of project management, network techniques, time and cost management; • identification of factors that could possibly contribute to the late completion of construction projects; • description of factors in terms of the following: definition and meaning of factors in context of project management; possible reasons why it occurs; consequences in the event of it occurring; possible solutions. Further follows the gathering, processing, analysing of the data and finally the conclusion and summary. With reference to this data, table i contains a list of factors that can possibly lead to the late completion of construction projects. All the factors that, according to the study, have a real contribution to the late completion of construction projects, are marked with an X in the remarks column of table i. When a project is thus initiated, it would be advisable to take note of the possible influences that the factors marked X in the remarks column of table i could have. This information is applicable to all projects in the study area irrespective of its characteristics. This information is also processed further so that conclusions can be drawn for projects with certain characteristics. This study shows that the average additional costs incurred for the late completion of a project are between 13,2 percent and 18,9 percent of the tender price, depending on the extent of the project. By focusing on critical factors, significant sums of money can thus be saved. The writer is of the opinion that the goals of the study regarding the actual subject were achieved. The results are highly applicable to the realities in practice and implementation thereof can certainly have significant results. Considering that no previous studies have been done on this subject, the focus of the study was wider than expected because the unknown is so much greater. With the study completed, further studies can now focus on the relevant aspects of the subject. This should lead to the refining of the aspects, resulting in a more practical implementation of the results.
AFRIKAANSE OPSOMMING: Moderne bestuursbeplanning en kontrolestelsels dateer sedert die Eerste Wêreldoorlog vanaf 1915. Henry L. Gantt het in dié tyd die strepieskaart ontwikkel, wat 'n drastiese verbetering op vorige metodes was. Die grootte, kompleksiteit en risiko's wat geassosieer word met hedendaagse, tegnies gesofistikeerde projekte, het vereis dat nuwe metodes ontwikkel moes word. Dit het gelei tot die ontwikkeling van die kritiekepad- metode, wat gedurende die tydperk 1956 tot 1958 in die Verenigde State van Amerika ontwikkel is. Sedertdien is verskeie metodes ontwikkel wat daarop gemik is om spesifieke behoeftes aan te spreek. Die mate van tydige voltooiing van konstruksieprojekte varieer drasties na gelang van die toepassing van projekskeduleringstegnieke. Hierdie stelling word bevestig deur verskeie studies wat geloods is om die skedulering en kontrolering van konstruksieprojekte te ontleed, maar vanweë :die komplekse tyd-koste-probleem wat gepaard gaan met konstruksieprojekte, word nog steeds probleme ondervind met die suksesvolle of tydige voltooiing van konstruksieprojekte. Met verwysing na die probleme wat ondervind word om konstruksieprojekte tydig te voltooi, gaan daar met dié ondersoek gepoog word om onderliggende redes daarvoor te soek en oplossings aan -,--..::.:.~.:.:" die hand te doen. Die ondersoek gaan dus-fokus op die redes waarom daar dikwels afgewyk word van skedules, en wat gedoen kan word om die afwykings te voorkom. Vandaar dan die onderwerp, wat as volg lui: 'n Ondersoek na die redes waarom konstruksieprojekte van munisipale dienste in baie gevalle laat voltooi word, alhoewel dit met behulp van netwerktegnieke geskeduleer is. Die prosedure wat gevolg is met die ondersoek, is eerstens die formulering van die doelwitte en studiegebied. Daarna volg 'n literatuurstudie, wat die volgende aspekte van die studie hanteer: • agtergrond van projekbestuur, netwerktegnieke en die bestuur van tyd en koste; • identifisering van faktore wat moontlik kan bydra tot die laat voltooiing van konstruksieprojekte; • beskrywing van die faktore in terme van die volgende: definisie en betekenis van faktor in konteks van projekbestuur; moontlike redes waarom dit voorkom; gevolge indien dit sou voorkom; moontlike oplossings. Verder volg die insameling, verwerking en analisering van die data en laastens die gevolgtrekkings en samevatting. Met verwysing na die data, toon Tabel ii 'n lys van die faktore wat geïdentifiseer is wat moontlik kan bydra tot die laat voltooiing van konstruksieprojekte. Alle faktore wat volgens die studie 'n wesenlike bydrae lewer tot die laat voltooiing van konstruksieprojekte, is in die opmerkingskolom van Tabel ii met 'n X gemerk. Wanneer 'n projek van stapel gestuur word, sal dit raadsaam wees om ag te slaan op die moontlike invloed van die faktore wat gemerk is met In X in die opmerkingskolom van Tabel ii. Die inligting is van toepassing op alle projekte in die studiegebied, ongeag die kenmerke van die projekte. Die inligting is ook verder verwerk sodat gevolgtrekkings gemaak kan word vir projekte met sekere kenmerke. Die studie toon aan dat die gemiddelde addisionele kostes as gevolg van die laat voltooiing van 'n projek, tussen 13,2 persent en 18,9 persent van die tenderbedrag beloop, afhangende van die omvang van die projek. Deur dus te fokus op die kritieke faktore, kan aansienlike bedrae geld bespaar word. Die skrywer is van mening dat die doelwitte van die studie aangaande dié aktuele onderwerp bereik is. Die resultate is hoogs van toepassing op die realiteite in die praktyk, en die toepassing daarvan kan beslis noemenswaardige resultate tot gevolg hê. Aangesien daar nie voorheen studies gedoen is oor die onderwerp nie, was die fokus van die studie breër as wat verwag is, omdat die onbekende soveel groter is. Met die studie voltooi, kan daar nou deur verdere studies gefokus word op die relevante aspekte van die onderwerp. Dit behoort te lei tot 'n verfyning van die aspekte, en gevolglik 'n meer praktiese toepassing van die resultate.

Submitted by Camila dos Anjos Ferraz (cacaferraz@gmail.com) on 2015-12-25T19:05:12Z No. of bitstreams: 1 Co-Creation in Hospitality Industry - a Case Study on the Drivers for Traveler-Generated Content.pdf: 2832811 bytes, checksum: de014292f47037eecdbc94c6ac2ec326 (MD5)
Rejected by Ana Luiza Holme (ana.holme@fgv.br), reason: Camila, O numero das paginas só pode aparecer a partir da introdução. Aguardo. Ana Luiza Holme 3799-3492 on 2016-01-04T11:14:13Z (GMT)
Submitted by Camila dos Anjos Ferraz (cacaferraz@gmail.com) on 2016-01-05T21:22:34Z No. of bitstreams: 1 Co-Creation in Hospitality Industry - a Case Study on the Drivers for Traveler-Generated Content.pdf: 2835215 bytes, checksum: 46c4a7a25788c28545d6f2e54f44fae6 (MD5)
Approved for entry into archive by Ana Luiza Holme (ana.holme@fgv.br) on 2016-01-06T11:12:17Z (GMT) No. of bitstreams: 1 Co-Creation in Hospitality Industry - a Case Study on the Drivers for Traveler-Generated Content.pdf: 2835215 bytes, checksum: 46c4a7a25788c28545d6f2e54f44fae6 (MD5)
Made available in DSpace on 2016-01-06T11:44:26Z (GMT). No. of bitstreams: 1 Co-Creation in Hospitality Industry - a Case Study on the Drivers for Traveler-Generated Content.pdf: 2835215 bytes, checksum: 46c4a7a25788c28545d6f2e54f44fae6 (MD5) Previous issue date: 2015-12-18
User-generated content in travel industry is the phenomenon studied in this research, which aims to fill the literature gap on the drivers to write reviews on TripAdvisor. The object of study is relevant from a managerial standpoint since the motivators that drive users to co-create can shape strategies and be turned into external leverages that generate value for brands through content production. From an academic perspective, the goal is to enhance literature on the field, and fill a gap on adherence of local culture to UGC given industry structure specificities. The business’ impact of UGC is supported by the fact that it increases e-commerce conversion rates since research undertaken by Ye, Law, Gu and Chen (2009) states each 10% in traveler review ratings boosts online booking in more than 5%. The literature review builds a theoretical framework on required concepts to support the TripAdvisor case study methodology. Quantitative and qualitative data compound the methodological approach through literature review, desk research, executive interview, and user survey which are analyzed under factor and cluster analysis to group users with similar drivers towards UGC. Additionally, cultural and country-specific aspects impact user behavior. Since hospitality industry in Brazil is concentrated on long tail – 92% of hotels in Brazil are independent ones (Jones Lang LaSalle, 2015, p. 7) – and lesser known hotels take better advantage of reviews – according to Luca (2011) each one Yelp-star increase in rating, increases in 9% independent restaurant revenue whereas in chain restaurants the reviews have no effect – , this dissertation sought to understand UGC in the context of travelers from São Paulo (Brazil) and adopted the case of TripAdvisor to describe what are the incentives that drives user’s co-creation among targeted travelers. It has an outcome of 4 different clusters with different drivers for UGC that enables to design marketing strategies, and it also concludes there’s a big potential to convert current content consumers into producers, the remaining importance of friends and family referrals and the role played by incentives. Among the conclusions, this study lead us to an exploration of positive feedback and network effect concepts, a reinforcement of the UGC relevance for long tail hotels, the interdependence across content production, consumption and participation; and the role played by technology allied with behavioral analysis to take effective decisions. The adherence of UGC to hospitality industry, also outlines the formulation of the concept present in the dissertation title of 'Traveler-Generated Content'.
Esta pesquisa estuda o fenômeno de conteúdo gerado por usuários aplicado à indústria de turismo com o objetivo de preencher a lacuna literária nas motivações que levam usuários à escrever avaliações no TripAdvisor. O objeto do estudo tem sua relevância gerencial uma vez que, identificadas as motivações dos viajantes para co-criar, estas possam tornar-se alavancas para geração de valor para marcas através da geração de conteúdo. Do ponto de vista acadêmico, o objetivo é expandir a literatura neste campo e endereçar a aderência de cultura local de co-criação aplicada às especifidades da indústria selecionada. O impacto de conteúdo gerado pelo usuário é endossado pelo fato das avaliações influenciarem as taxas de conversão. De acordo com a pesquisa conduzida por Ye, Law, Gu e Chen (2009), para cada 10% incremental na avaliação de um hotel, as reservas online crescem em 5%. A revisão literária constrói o modelo teórico para embasar a metodologia de estudo de caso do TripAdvisor. Aspectos quantitativos e qualitativos compõem a abordagem metodológica por meio de revisão literária, pesquisa por dados secundários, entrevista com executivo e pesquisa com usuários processadas com análises fatoriais e de agrupamentos (clusters). Além disso, o comportamento do usuário é impactado por aspectos culturais, o que diferencia suas motivações. A indústria de hospitalidade no Brasil é predominantemente dispersa sendo 92% dos quartos de hotéis independentes (Jones Lang LaSalle, 2015, p. 7) e hotéis menos conhecidos tendem a ser mais beneficiados em consideração do consumidor depois de receber avaliações segundo Luca (2011), que observou que o aumento de uma estrela na avaliação do Yelp, aumenta em 9% o faturamento de restaurantes independentes, enquanto nos de rede não há nenhum impacto. Portanto, essa dissertação almeja entender a geração de conteúdo por usuários no contexto de viajantes de São Paulo, Brasil, adotando o caso do TripAdvisor para descrever os incentivos para co-criação de usuários entre o público selecionado. A análise entrega quatro diferentes grupos que permitem embasar o desenvolvimento de estratégias de marketing. O estudo também sugere a existência de potencial na conversão de atuais consumidores de conteúdo em produtores de conteúdo, a remanescente importância das recomendações de familiares e amigos e o papel exercido por incentivos. Dentre as conclusões, a pesquisa leva à exploração dos conceitos de feedback positivo e efeito de rede, o reforço da relevância de conteúdo gerado por usuários para hotéis independentes, a interdependência entre participação, produção e consumo de conteúdo e o papel exercido pela tecnologia, aliada à análises comportamentais, na tomada de decisões. A aderência do conceito de UGC à indústria de hospitalidade nos leva ao conceito presente no título da dissertação de 'Conteúdo Gerado por Viajantes'.

L’augmentation de la demande en bois énergie nécessite une meilleure connaissance des systèmes le produisant. La thèse porte sur la modélisation de la filière de production de bois énergie sous forme de plaquettes forestières.Les sciences forestières conçoivent notamment des modèles de croissance dont certains permettent d’évaluer la répartition des biomasses et minéraux au sein des arbres. L’étude des procédés de récolte des bois et de leur transformation et mise à disposition est faite par une communauté de recherche en sciences forestières et sciences du bois selon les principes des sciences des procédés. En sciences de l’énergie le contenu élémentaire du bois est mis en relation avec son pouvoir calorifique.En articulant et en complétant ces connaissances, la thèse propose une approche originale d’intégration cohérente des modèles des différentes disciplines. Cette approche ascendante permet de conserver un niveau d’information fin sur le système étudié et une souplesse importante dans les configurations de filière envisagées.Des modèles originaux des tâches de la filière ont été développés. Leur formulation tient compte du niveau de détails le plus souvent rencontré dans la littérature de la discipline. Un modèle original a été développé pour prédire les caractéristiques du combustible livré à partir du contenu en nutriment estimé dans les arbres sur pied.Un dispositif logiciel original a permis l’articulation des modèles. Cet outil de simulation, « ForEnerChips », permet de calculer les flux de matière et d’énergie depuis la croissance forestière, via les tâches successives de la filière, jusqu’à l’entrée de la chaudière. Cela permet d’évaluer des bilans énergétiques, et la quantification des minéraux exportées et restituées au sol, selon les choix effectués tout le long de la filière. Son implémentation sur la plateforme logicielle CAPSIS doit favoriser une intégration en fonction des besoins à d’autres modèles de croissance parmi les quelques 70 disponibles ou en développement pour différentes espèces, régions ou sylvicultures.Dans le temps de la thèse, le simulateur de filière a été lié avec un modèle de croissance pour le hêtre (Fagus sylvatica L.). Un scénario représentatif de pratiques de terrain a été étudié puis comparé avec des scénarios alternatifs. D’autres pistes d’études sont proposées
The increasing demand for energy wood requires a better knowledge about the production system. This work is about modelling the chain producing wood chips for energy.Growth and yield models are built by forest scientists, and some models can predict contents in biomass and nutrients in trees. The study of the chain of harvesting, transforming and transporting energy wood is made by a community of forest and wood scientists, relying on principles from process engineering. Fuel qualities from elemental composition are modelled in the field of energy sciences.By connecting and completing this knowledge, the thesis proposes an original approach to consistently integrate models from the different fields of science. This bottom-up approach conserves a high level of information about the system, and a high flexibility in the configuration of the simulated chain.Original models were developed for the chain. Model formulation was made respecting the most frequent level of detail found in literature. An original model was developed to predict fuel quality relying on nutrient content predicted with models developed in forest sciences.A software tool was developed to integrate these models. “ForEnerChips” calculates material fluxes from forest growth to heating plant via the whole chain. This allows for the assessment of energy balances, and nutrient exportations and restitutions, according to choices made in the configuration of the chain (scenario analysis). Its implementation into the CAPSIS software platform allows a potential connection to about 70 growth and yield models for different species, regions or management regimes.The simulator was connected so far to a particular growth and yield model for common beech (Fagus sylvatica L.). A scenario representative of current management practices was studied and compared to alternative scenarios. Other ideas of potential uses are suggested

Les champignons basidiomycetes filamenteux sont parmi les plus performants pour la degradation de la lignine. Ils doivent leur activite a un complexe enzymatique au sein duquel trois enzymes jouent un role fondamental dans les mecanismes d'oxydation de la lignine. Il s'agit des lignines peroxydases (lip), des manganese peroxydases (mnp) et des laccases (lac). Trois souches fongiques, phlebia radiata (lip, mnp, lac), ceriporiopsis subvermispora (mnp, lac) et pleurotus eryngii (mnp, lac), ont ete selectionnees pour leur aptitude a degrader la paille de ble, dans le but d'utiliser les enzymes les plus efficaces pour la delignification de pates papetieres de paille. L'etude a ete realisee en microscopie electronique a transmission dans le but de montrer comment la nature du substrat et l'equipement enzymatique influencaient la degradation. L'organisation ultrastructurale des tissus lignifies constituant la paille de ble a tout d'abord ete etudiee. Pour cela nous avons mis en uvre de nouveaux marqueurs immunologiques des lignines. La caracterisation des differents types de lignine a mis en evidence des specificites liees a la nature des monolignols constitutifs et aussi a la nature des liaisons inter-unites de type condense et non-condense. L'application de ces marqueurs immunocytochimiques a revele l'heterogeneite de la distribution qualitative des lignines dans les differents tissus et au sein d'un meme type cellulaire. Dans une seconde partie du travail, l'aptitude des champignons a liberer leur enzymes lorsqu'ils se developpent dans la paille a ete etudiee. A l'aide d'anticorps diriges respectivement contre les mnp et les lac nous avons pu suivre la production, par les champignons, de leur enzymes extracellulaires. Ces enzymes sont excretees de facon concomitante au voisinage du site de degradation. Elles n'apparaissent pas dans les hyphes au contact des tissus sains. A des stades de degradation plus avances, l'excretion des mnp et lac a pu etre reliee a la nature de la lignine localement exposee a la degradation. Il a pu etre etabli que l'excretion etait plus forte au contact d'une lignine condensee. L'observation in situ a souligne le role du polysaccharide extracellulaire a l'interface entre paroi lignocellulosique et paroi de l'hyphe, dans le support de certaines enzymes excretees. Les marqueurs de lignines ont en outre revele la presence de fragments de degradation transitant a travers la paroi des hyphes. L'intensite des marquages avec les differents anticorps suggere que les fragments syringiques ont subi une demethylation avant d'etre metabolises dans la paroi de l'hyphe. La delignification des pates chimiomecaniques par des preparations de mnp et de lac purifiees ont montre que ces deux enzymes realisaient des defibrillations locales tres efficaces.

Bioplastics have been the focus of worldwide research and development to tackle the lack of biodegradability and dependence on fossil resources of most conventional plastics. In particular, polyhydroxyalkanoates (PHA) are fully biodegradable polymers that can be produced by microorganisms from low cost substrates, such as wood industry residues. Bio-oil corresponds to the liquid phase from the fast pyrolysis of lignocellulosic biomass and has high concentrations of carboxylic acids, sugars derivatives, and others that make it a potential feedstock for microbial processes, including PHA production. In terms of potential substrates for the microorganisms, the water-soluble phase of pinewood bio-oil contained mostly formic and acetic acids, as well as levoglucosan and other sugar derivatives. The latter were converted into Dglucose and D-mannose through acidic hydrolysis. In this work, the production of PHA by Cupriavidus necator and Pseudomonas GL01 was studied using pinewood bio-oil from fast pyrolysis as substrate. The preliminary flask assays were performed with glucose and acetic acid to assess their consumption by C. necator DSM 531 and DSM 545, which revealed that the strain DSM 545 was more efficient in using glucose, thus it was chosen for the tests with bio-oil. Several concentrations of hydrolysed bio-oil (HBO) and medium compositions were tested for C. necator DSM 545 to sort the optimal concentration for PHA production. These assays revealed that this strain was not able to use glucose in HBO. Nevertheless, the best medium for C. necator DSM 545 was composed of 9% (v/v) of HBO in the supplementary medium 2, with NaHCO3, FeCl3 and di-ammonium citrate. The bioreactor fed-batch assay performed with the selected medium composition and subsequent HBO pulses of 4.5% (v/v) resulted in a total cell concentration of 1.04 g L -1 , with 3.8% of P3HB-(10%)3HV and volumetric productivity of 0.83 mg L-1 h -1 , after 36 hours. Pseudomonas GL01 showed a better growth and PHA production in 9% (v/v) HBO, resulting in 1.62 g L-1 of cell concentration, with 33% of PHA, after 48 h. A fed-batch reactor assay was performed with 9% (v/v) of HBO and subsequent pulses of 4.5% (v/v), resulting in biomass concentration of 1.66 g L-1 . This work demonstrated, for the first time, the utilization of hydrolysed pinewood bio-oil by C. necator DSM 545 and Pseudomonas GL01 for the production of PHA as a potential route to the valorisation of forest residues.
Os bioplásticos têm sido alvo de investigação e desenvolvimento para solucionar a recalcitrância e dependência de recursos fósseis, características dos plásticos convencionais. Em particular, os poli-hidroxialcanoatos (PHA) são polímeros biodegradáveis que podem ser produzidos por microrganismos a partir de substratos de baixo custo, como os resíduos da indústria da madeira. O bio-óleo corresponde à fase líquida resultante do processo de pirólise rápida de biomassa lenhocelulósica e tem elevadas concentrações de ácidos carboxílicos, derivados de açúcares e outros, que o tornam uma potencial matéria-prima para processos microbianos, tais como a produção de PHA. Em termos de potenciais substratos para os microrganismos, a fase aquosa do bio-óleo continha sobretudo ácido fórmico e ácido acético, bem como levoglucosan e outros derivados de açúcares. Estes últimos foram convertidos em D-glucose e Dmanose através da hidrólise ácida. Neste trabalho estudou-se a produção de PHA por Cupriavidus necator e Pseudomonas GL01 usando bio-óleo de pirólise rápida de madeira pinho como substrato. Para avaliar o consumo de glucose e ácido acético por C. necator DSM 531 e DSM 545 realizaram-se ensaios preliminares em Erlenmeyer com meio sintético. Verificou-se que a estirpe DSM 545 usou glucose com maior eficiência e, por isso, foi escolhida para os testes com bio-óleo. Para escolher a concentração ótima de bio-óleo hidrolisado (HBO) para a produção de PHA por C. necator DSM 545, testaram-se várias concentrações, bem como diferentes composições do meio. Estes ensaios revelaram que esta estirpe não utilizava a glucose presente no HBO. Ainda assim, o meio que resultou em melhores resultados era composto de 9% (v/v) de HBO em meio suplementar 2, com a adição de NaHCO3, FeCl3 e citrato de amónia. Finalmente realizou-se um ensaio em fed-batch em biorreator com o meio selecionado e pulsos de HBO de 4.5% (v/v) que resultaram numa concentração celular de 1.04 g L-1 , com 3.8% de P3HB-(10%)3HV e uma produtividade volumétrica de 0.83 mg L-1 h -1 , após 36 horas. Pseudomonas GL01 demonstrou melhor crescimento e produção de PHA na concentração de 9% (v/v) de HBO, resultando numa concentração celular de 1.62 g L-1 , com 33% de PHA, após 48 h. O ensaio fed-batch em reator foi feito com 9% (v/v) de HBO e pulsos subsequentes de 4.5% (v/v), resultando na concentração celular de 1.66 g L-1 . Este trabalho demonstrou pela primeira vez a utilização de bio-óleo hidrolisado de madeira pinho por C. necator DSM 545 e Pseudomonas GL01 para a produção de PHA, como uma potencial oportunidade de valorização de resíduos da indústria da madeira.
Mestrado em Biotecnologia