997 resultados para Wood construction


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Acacia mearnsii de Wild (black wattle) is one of the most important trees planted in Southern Brazil for tannin extraction and charcoal production. The pyrolysis of the black wattle wood used for obtaining charcoal is performed in brick ovens, with the gas fraction being sent directly into the environment. The present study examines the condensable compounds present in the liquor produced from black wattle wood at different thermal degradation conditions, using gas chromatography coupled with mass spectrometry (GC/MS). Branches of black wattle were thermally degraded at controlled ambient and temperature conditions. Overall, a higher variety of compounds were obtained under atmospheric air pressure than under synthetic air pressure. Most of the tentatively identified compounds, such as carboxylic acids, phenols, aldehydes, and low molecular mass lignin fragments, such as guayacol, syringol, and eugenol, were products of lignin thermoconversion. Substituted aromatic compounds, such as vanillin, ethyl vanillin, and 2-methoxy-4-propeny-phenol, were also identified. At temperatures above 200 ºC, furan, 2-acetylfuran, methyl-2-furoate, and furfural, amongst others, were identified as polysaccharide derivatives from cellulose and hemicellulose depolymerization. This study evidences the need for adequate management of the condensable by-products of charcoal production, both for economic reasons and for controlling their potential environmental impact.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The purpose of the thesis is to study innovativeness in a context of the construction industry especially the front-end of the innovation process. The construction industry is often considered an old-fashioned manufacturing industry. Innovations and innovativeness are rarely linked to the industry. The construction industry, as well as other industries in Finland, is facing challenges such as productivity, the climate change and internationalization. The meaning of innovations is greater than ever in continuously changing markets, for standing out from competitors or increasing the competitiveness. Traditional production methods, tight building regulations, unique buildings, one-of-a-kind project organizations and highlighting the cheapest price in building contracts are particular challenges in the construction industry. The research questions of the thesis were: - What kind of factors shift the existing company culture towards innovativeness? - What are the phases of the front-end of the innovation process? - What kind of tools and methods enable managing the front-end of the innovation process? The theoretical part of the thesis bases on the literature review. The research methodology of the empirical part was the action research and qualitative approach. Empirical data was collected by the theme interviews from three companies. The results were practical methods and experiences from innovation activities of the companies. The results of the thesis can be clarified as follows: enhancement of the innovation activities requires support and commitment of the top management, innovative culture and innovation strategy. Innovativeness can be promoted by systematical methods for example collecting ideas from employees. Controlling and managing the front-end phase is essential to succeeding. Despite that managing the front-end is the most challenging part of the innovation process, development and management of that save companies’ money, resources and prevents useless investments. Further clarification and studies are needed to find out furthermore functional tools and methods to manage innovations and implementing them to the culture of the companies.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Työssä käsitellään puutuotteiden ja -rakenteiden liiketoiminta-alueita yhtenä toimialana. Tavoitteena on tuoda esille tämän toimialan ja rakentamisen toimialan yhteistyön motiiveja ja haasteita pientalorakentamisen liiketoiminta-alueella. Koska toimialojen välinen yhteistyö näkyy aina käytännön tasolla yritysten välisenä yhteistyönä, työssä käydään läpi yritysten välisen yhteistyön motiiveja ja haasteita, erityisesti T&K- yhteistyön ja arvoketjuyhteistyön osalta. T&K-yhteistyön avulla on mahdollista luoda uusia innovaatioita erilaisten kyvykkyyksien pohjalta. Yhteistyöllä voidaan saavuttaa yhteistuotannon tuottoja, kilpailuetua ja asiakasarvon kasvattamista. Yhteistyön syntymiselle aiheutuu eniten haasteita sen vaatiman luottamuksellisuuden ja opportunismin uhan myötä. Toimialojen välinen yhteistyö suomalaisen pientalorakentamisen liiketoiminta-alueella on enimmäkseen melko yksinkertaisen arvoketjuyhteistyön tasolla. Toimialan rakenne on haastava, joten syvällisemmän yhteistyön avulla voitaisiin parantaa puutuotealan PK-yritysten asemaa. Erityisesti PK- yritysten strateginen T&K- ja markkinointiyhteistyö olisi suotavaa, mutta se vaatii myös uskallusta luottaa yhteistyökumppaniin.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Interest in recovery of valuable components from process streams has increased in recent years. Purpose of biorefinery is to utilize components that otherwise would go to waste. Hemicelluloses, for example, could be utilized in production of many valuable products. One possible way to separate and fractionate hemicelluloses is membrane filtration. In the literature part of this work membrane fouling in filtration processes of pulp and paper process- and wastewaters was investigated. Especially purpose was to find out the possible fouling compounds, after which facilities to remove or modify such components less harmful were studied. In the experimental part different pretreatment methods, mainly to remove or degrade lignin from wood hydrolysate, were studied. In addition, concentration of hemicelluloses and separation from lignin were examined with two ultrafiltration membranes; UFX5 and RC70PP. Changes in feed solution, filtration capacity and fouling of membranes were used to evaluate the effects of pretreatment methods. Changes in hydrolysate composition were observed with different analysis methods. Filtration of hydrolysate proved to be challenging, especially with the UFX5 membrane. The more hydrophilic RC70PP membrane did not seem to be fouled as severely as the UFX5 membrane, according to pure water flux measurements. The UFX5 membrane retained hemicelluloses rather well, but problems arose from rapid flux decline resulting from concentration polarization and fouling of membrane. Most effective pretreatment methods in the case with the UFX5 membrane proved to be prefiltration with the RC70PP membrane, activated carbon adsorption and photocatalytic oxidation using titanium dioxide and UV radiation. An additional experiment with PHW extract showed that pulsed corona discharge treatment degraded lignin quite efficiently and thus improved filtration capacity remarkably, even over six times compared to the filtration with untreated extract.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The usage of the non-wood pulps in furnishes for various paper grades is the real alternative for substitution of wood fibres in the papermaking. This is especially important now, when the prices for wood are increasing and forest resources are depleting in many regions of our planet. However, there are several problems associated with utilization of such pulps. In terms of the papermaking process one of the main problems is the poor dewatering of the non-wood pulps. This problem can be partially solved by means of retention aids. In the literature part were described technological features of the non-wood pulps as the raw materials for paper production. Moreover, overviews of the retention chemicals and methods for retention measurement were done; special attention was paid to the mechanisms of retention and drainage. Finally, factors affecting on the drainage and retention of non-wood pulps were considered holistically. Particular emphasis was put on the possibility of enzyme treatment for drainage improvement. It was stated that retention aids can significantly improve dewatering of non-wood pulps. In the experimental part the goal was to investigate influence of various microparticle retention aids on the drainage, retention and formation of furnish containing wheat straw pulp, obtained by novel pulping process (Formico™Fib). The parallel test were performed with reference furnish containing only wood pulps. It was found that Bentonite-CPAM retention aid can significantly improve drainage and retention; however formation seems be suffer from such additives. It was stated that performance of the Silica-Starch retention aid significantly depends on the starch dosing sequence and wet-end conditions; this system have shown better formation than other tested retention aids. Silica-CPAM retention aid have provided comparable results in retention and drainage with Bentonite-CPAM, while Silica-starch did not improve dewatering and yielded in lowest filler retention among other aids. Ultimately, optimal dosages for the tested retention chemicals have been suggested.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The correct utilization of non-wood raw material allows reducing tree cutting and reduces emissions of carbon dioxide from burning of non-wood plants on farmers fields. Also it allows increasing economical situation in regions that non-wood plants are grown and where they are converted into pulp and paper. Also it gives positive effect on population pressure of work by addition of working place. In the literature survey included an overview of the historical meaning of non-wood pulp on developing paper production and structure of non-wood pulps. Moreover, anatomical and chemical composition of straw, reed and bamboo were studied more detailed. Also, an overview of the utilization of non-wood pulp in papermaking was made. Especially tissue, tree-free and release papers were reviewed. In the experimental part the goal was to investigate suitability of non-wood pulp like wheat straw pulp and bamboo pulp for different fiber products. Finally release and tree-free paper products were selected for experimental studies. It was discovered that wheat straw, especially screened wheat straw, showed good results for release paper. Also utilization of wheat straw and bamboo pulp in tree-free paper showed good results and suitability of these non-wood pulps for tree-free paper production. Also it was noticed that addition of wheat straw pulp gave positive effect on initial wet strength for release and tree-free paper.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The pre-treatment step has a significant influence on the performance of bioenergy chains, especially on logistics. In nowadays conditions it is important to have technologies allowing to convert biomass at modest scales into dense energy carriers that ease transportation and handling. There are such technologies as charring and torrefaction. It is a thermal treatment of organic waste (only woody biomass is considered as a raw material in this work), which aims to produce a fuel with increased energy density. Wood processing is attractive under meaning of green house gas emissions. Charring and torrefaction are promising technologies due to its high process efficiency. It may be also attractive in the future as a renewable fuel with improved storage properties, increased energy density (compared to raw wood) for co-combustion and/or gasification.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The purpose of this case study is to clarify how KM (knowledge management) capability is constructed through six different activities and to explore how this capability can be diagnosed and developed in the three case organizations. The study examines the knowledge management capability of the three factories in UPM-Kymmene Wood Oy, a major Finnish plywood producer. Forest industry is usually considered to be quite hierarchical. The importance of leveraging employee skills and knowledge has been recognized in all types of organizations – including those that mainly deal with tangible resources. However, the largest part of empirical knowledge management literature examines KM in so called knowledge-intensive or knowledge-based organizations. This study extends existing literature by providing an in depth case study into assessment and development of KM activities in these three organizations with little awareness of the KM discourse. This subject is analyzed through literature review, theoretical analysis and empirical research in the case organizations. The study also presents a structured method for evaluating KM activities of a company and for diagnosing the main weaknesses that should be developed in order to achieve KM excellence. The results help in understanding how knowledge management capability is constructed and provide insight into developing and exploiting it within an organization.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

During the past century, an increasingly diverse world provided us with opportunities for intercultural communication; especially the growth of commerce at all levels from domestic to international has made the combination of the theories of intercultural communication and international business necessary. As one of the main beneficiaries in international business in recent years, companies in airline industries have developed their international market. For instance, Finnair has developed its Asian strategy which responds to the increasing market demand for flights from Europe to Asia in the new millennium. Therefore, the company manages marketing communication in a global environment and becomes a suitable case for studying the theories of intercultural communication in the context of international marketing. Finnair implemented a large number of international advertisements to promote its Asian routes, where Asia has been constructed as a number of exotic destinations. Meanwhile, the company itself as a provider of these destinations has also been constructed contrastively. Thus, this thesis aims at research how Finnair constructs Asia and the company itself in the new millennium, and how these constructions compare with the theories of intercultural communication. This research applied the theories of international marketing, intercultural communication and culture. In order to analyze the collected corpora as Finnair’s international advertisements and its annual reports in the new millennium, the methods of content analysis and discourse analysis have been used in this research. As a result, Finnair has purposefully applied the essentialist approach to intercultural communication and constructed Asia as an exotic “Other” due to the company’s market orientation. Meanwhile, Finnair has also constructed the company itself two identities based on the same approach: as an international airline provider between Europe and Asia, as well as a part of Finnish society. The combination of intercultural communication and international marketing theories, together with the combination of the methods of content analysis and discourse analysis ensure the originality of this paper.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

This work is based on the utilisation of sawdust and wood chip screenings for different purposes. A substantial amount of these byproducts are readily available in the Finnish forest industry. A black liquor impregnation study showed that sawdust-like wood material behaves differently from normal chips. Furthermore, the fractionation and removal of the smallest size fractions did not have a significant effect on the impregnation of sawdust-like wood material. Sawdust kraft cooking equipped with an impregnation stage increases the cooking yield and decreases the lignin content of the produced pulp. Impregnation also increases viscosity of the pulp and decreases chlorine dioxide consumption in bleaching. In addition, impregnation increases certain pulp properties after refining. Hydrotropic extraction showed that more lignin can be extracted from hardwood than softwood. However, the particle size had a major influence on the lignin extraction. It was possible to extract more lignin from spruce sawdust than spruce chips. Wood chip screenings are usually combusted to generate energy. They can also be used in the production of kraft pulp, ethanol and chemicals. It is not economical to produce ethanol from wood chip screenings because of the expensive wood material. Instead, they should be used for production of steam and energy, kraft pulp and higher value added chemicals. Bleached sawdust kraft pulp can be used to replace softwood kraft pulp in mechanical pulp based papers because it can improve certain physical properties. It is economically more feasible to use bleached sawdust kraft pulp in stead of softwood kraft pulp, especially when the reinforcement power requirement is moderate.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

PIXE (Particle Induce X-ray Emission spectrometry) was used for analysing stem bark and stem wood of Scots pine, Norway spruce and Silver birch. Thick samples were irradiated, in laboratory atmosphere, with 3 MeV protons and the beam current was measured indirectly using a photo multiplicator (PM) tube. Both point scans and bulk analyses were performed with the 1 mm diameter proton beam. In bulk analyses, whole bark and sectors of discs of the stem wood were dry ashed at 550 ˚C. The ashes were homogenised by shaking and prepared to target pellets for PIXE analyses. This procedure generated representative samples to be analysed, but the enrichment also enabled quantification of some additional trace elements. The ash contents obtained as a product of the sample preparation procedure also showed to be of great importance in the evaluation of results in environmental studies. Spot scans from the pith of pine wood outwards, showed clearly highest concentrations of manganese, calcium and zinc in the first spot irradiated, or 2-3 times higher than in the surrounding wood. For stem wood from the crown part of a pine this higher concentration level was found in the first four spots/mms, including the pith and the two following growth rings. Zinc showed increasing concentrations outwards in sapwood of the pine stem, with the over-all lowest concentrations in the inner half of the sapwood. This could indicate emigration of this element from sapwood being under transformation to heartwood. Point scans across sapwood of pine and spruce showed more distinct variations in concentrations relative to hearth wood. Higher concentrations of e.g. zinc, calcium and manganese were found in earlywood than in denser latewood. Very high concentrations of iron and copper were also seen for some earlywood increments. The ash content of stem bark is up to and order higher than for the stem wood. However, when the elemental concentration in ashes of bark and wood of the same disc were compared, these are very similar – this when trees are growing at spots with no anthropogenic contamination from the atmosphere. The largest difference was obtained for calcium which appeared at two times high concentrations in ashes of bark than in ashes of the wood (ratio of 2). Pine bark is often used in monitoring of atmospheric pollution, where concentrations in bark samples are compared. Here an alternative approach is suggested: Bark and the underlying stem wood of a pine trees are dry ashed and analysed. The elemental concentration in the bark ash is then compared to the concentration of the same element in the wood ash. Comparing bark to wood includes a normalisation for the varying availability of an element from the soil at different sites. When this comparison is done for the ashes of the materials, a normalisation is also obtained for the general and locally different enrichment of inorganic elements from wood to bark. Already a ratio >2 between the concentration in the bark ash and the concentration in the wood ash could indicate atmospheric pollution. For monitoring where bark is used, this way of “inwards” comparison is suggested - instead of comparing to results from analyses of bark from other trees (read reference areas), growing at sites with different soil and, locally, different climate conditions. This approach also enables evaluation of atmospheric pollution from sampling of only relative few individual trees –preferable during forest felling.