996 resultados para wall material
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This thesis investigated building information modeling (BIM) from a material supplier’s point of view. The objective was to gain understanding about how a building material supplier could benefit from the growing use of BIM in the AEC (architectural, engineering and construction) industry. Increasing amount of inquiries related to BIM from customers and other interest groups had awoken target company’s interest towards BIM. This thesis acts as a pre-study for the target company related to potential of BIM. First of all BIM and its meaning from a material supplier’s point of view was defined based on a literature review. To reveal the potential benefits of BIM for a material supplier a questionnaire survey and in total of 11 interviews were conducted. Based on the literature review and analyzed results it came clear that BIM offers benefits also for material suppliers. Product libraries and material databases for BIM tools can act as an important marketing channel for material suppliers. Material suppliers could also utilize the information from the BIM models to schedule their deliveries more precisely and potentially even to schedule their own production. All this needs deeper cooperation between material suppliers, contractors and other stakeholders in the AEC industry. Based on the results also first steps for the target company to utilize the growing use of BIM were defined.
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In many engineering applications, compliant piping systems conveying liquids are subjected to inelastic deformations due to severe pressure surges such as plastic tubes in modern water supply transmission lines and metallic pipings in nuclear power plants. In these cases the design of such systems may require an adequate modeling of the interactions between the fluid dynamics and the inelastic structural pipe motions. The reliability of the prediction of fluid-pipe behavior depends mainly on the adequacy of the constitutive equations employed in the analysis. In this paper it is proposed a systematic and general approach to consistently incorporate different kinds of inelastic behaviors of the pipe material in a fluid-structure interaction analysis. The main feature of the constitutive equations considered in this work is that a very simple numerical technique can be used for solving the coupled equations describing the dynamics of the fluid and pipe wall. Numerical examples concerning the analysis of polyethylene and stainless steel pipe networks are presented to illustrate the versatility of the proposed approach.
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Operation of pulp and paper mills generates waste including wastewater treatment sludge and deinking sludge. Both sludge types are generated in large amounts and are mainly disposed of in landfills in the Leningrad Region resulting in environmental degradation. The thesis was aimed at seeking new sustainable ways of sludge utilization. Two paper mills operating in the Leningrad Region and landfilling their sludge were identified: “SCA Hygiene Products Russia” and “Knauf”. The former generates 150 t/day of deinking sludge, the latter – 145 t/day of secondary sludge. Chemical analyses of deinking sludge were performed to assess applicability of sludge in construction materials production processes. Higher heating value on dry basis of both sludge types was determined to evaluate energy potential of sludge generated in the Leningrad Region. Total energy output from sludge incineration was calculated. Deinking sludge could be utilized in the production process of “LSR-Cement” or “Slantsy Cement Plant Cesla” factories, and “Pobeda” and “Nikolsky” brick mills without exceeding current sludge management costs.
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Fiber-reinforced composites (FRCs) are a new group of non-metallic biomaterials showing a growing popularity in many dental and medical applications. As an oral implant material, FRC is biocompatible in bone tissue environment. Soft tissue integration to FRC polymer material is unclear. This series of in vitro studies aimed at evaluating unidirectional E-glass FRC polymer in terms of mechanical, chemical, and biological properties in an attempt to develop a new non-metallic oral implant abutment alternative. Two different types of substrates were investigated: (a) Plain polymer (BisGMA 50%–TEGDMA 50%) and (b) Unidirectional FRC. The mechanical behavior of high fiber-density FRCs was assessed using a three-point bending test. Surface characterization was performed using scanning electron and spinning disk confocal microscopes. The surface wettability/energy was determined using sessile drop method. The blood response, including blood-clotting ability and platelet morphology was evaluated. Human gingival fibroblast cell responses - adhesion kinetics, adhesion strength, and proliferation activity - were studied in cell culture environment using routine test conditions. A novel tissue culture method was developed and used to evaluate porcine gingival tissue graft attachment and growth on the experimental composite implants. The analysis of the mechanical properties showed that there is a direct proportionality in the relationship between E-glass fiber volume fraction and toughness, modulus of elasticity, and load bearing capacity; however, flexural strength did not show significant improvement when high fiber-density FRC is used. FRCs showed moderate hydrophilic properties owing to the presence of exposed glass fibers on the polymer surface. Blood-clotting time was shorter on FRC substrates than on plain polymer. The FRC substrates also showed higher platelet activation state than plain polymer substrates. Fibroblast cell adhesion strength and proliferation rate were highly pronounced on FRCs. A tissue culture study revealed that gingival epithelium and connective tissue established an immediate close contact with both plain polymer and FRC implants. However, FRC seemed to guide epithelial migration outwards from the tissue/implant interface. Due to the anisotropic and hydrophilic nature of FRC, it can be concluded that this material enhances biological events related with soft tissue integration on oral implant surface.
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The aim of this work is to study the results of tensile tests for austenitic stainless steel type 304 and make accurate FE-models according to the results of the tests. Tensile tests were made at Central Research Institute of Structural Material, Prometey at Saint Petersburg and Mariyenburg in Russia. The test specimens for the tensile tests were produced at Lappeenranta University of Technology in a Laboratory of Steel Structures. In total 4 different tests were made, two with base material specimens and two with transverse butt weld specimens. Each kind of a specimen was tested at room temperature and at low temperature. By comparing the results of room and low temperature tests of similar test specimen we get to study the results of work hardening that affect the austenitic steels at below room temperature. The produced specimens are to be modeled accurately and then imported for nonlinear FEM- analyzing. Using the data gained from the tensile tests the aim is to get the models work like the specimens did during the tests. By using the analyzed results of the FE-models the aim is to calculate and get the stress-strain curves that correspond to the results acquired from the tensile tests.
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Dialypetalanthus fuscescens is an Amazonian endemic species with problematic taxonomic position. This neotropical rainforest tree belongs to the monospecific Dialypetalanthaceae. In the present work, we analysed the leaf cell-wall polysaccharide composition of Dialypetalanthus fuscescens and compared it to that of Bathysa meridionalis (Rubiaceae-Cinchonoideae). Glycosyl composition and glycosyl-linkage analysis indicated that both species have similar cell wall composition. Arabinogalactans were the major component of the pectic polysaccharides and xylans, although being reported in minor amounts in dicots, were found to be the predominant hemicellulosic polysaccharide in cell walls of both species. These findings are in agreement with previous data on cell wall composition reported for Rubiaceae and corroborate the current suggestion of the possible link between this family and Dialypetalanthaceae.
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O gênero Staurogyne Wall. reúne cerca de 140 espécies tropicais, com 28 destas reconhecidas para os neotrópicos, encontradas principalmente em áreas florestais preservadas. A revisão atualizada do gênero para as Américas revelou quatro espécies inéditas para o território brasileiro, aqui descritas. Os novos táxons são conhecidos para os Estados de Goiás, Minas Gerais, Espírito Santo, São Paulo, Rio de Janeiro, Paraná e Santa Catarina, três na Floresta Pluvial Atlântica, e uma nas matas de galeria, nos domínios do cerrado.
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Presentation at the 12th Bibliotheca Baltica Symposium at Södertörn University Library
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The aims were to find out 1) if schools’ oral health practices were associated with pupils’ oral health behaviour and whether 2) the national sweet-selling recommendation and 3) distributing oral health material (OHEM) affected schools as oral health promoters. Three independently collected datasets from Finnish upper comprehensive schools (N=988) were used: longitudinal oral health practices data (n=258) with three-year follow up (2007 n=480, 2008 n=508, 2009 n=593) from principals’ online questionnaires, oral health behaviour data from pupils participating in the national School Health Promotion Study (n=970 schools) and oral health education data from health education teachers’ online questionnaires (2008 n=563, 2009 n=477 teachers). Oral health practices data and oral health behaviour data were combined (n=414) to answer aim 1. For aims 2 and 3, oral health practices data and oral health education data were used independently. School sweet selling and an open campus policy were associated with pupils’ use of sweet products and tobacco products during school time. The National Recommendation was quite an effective way to reduce the number of sweet-selling schools, but there were large regional differences and a lack of a clear oral health policy in the schools. OHEM did not increase the proportion of teachers teaching oral health, but teachers started to cover oral health topics more frequently. Women started to use OHEM more often than men did. Schools’ oral health policy should include prohibiting the selling of sweet products in school by legislative actions, enabling healthy alternatives instead, and setting a closed campus policy to protect pupils from school-time sweet consuming and smoking.
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The objective of this Master´s Thesis was to conduct a wide scale preliminary survey regarding the package requirements of a cultured dairy package, and to compare the currently used material polystyrene to other suitable packaging materials. Polystyrene has a long history of use in dairy cups, but in recent years its price has increased significantly compared to other common packaging materials. The overall environmental effects of a package and a package material are today a part of designing a sustainable product life cycle. In addition, in certain contexts there has been discussion of the risks posed by styrene polymer for the environment and for humans. These risks are also discussed in this thesis. Polystyrene (PS) is still the most widely used material in dairy cups. In recent years, polypropylene (PP) cups have appeared in increasing numbers on market shelves. This study focuses on the differences of the suitable polymers and examines the suitability of alternative “suitable” polymers with regards to dairy packaging. Aside from focusing on the cup manufacturer, this thesis also examines its subject matter from the viewpoint of the dairy customer, as well as observing the concrete implications of material changes in the overall value chain. It was known in advance that material permeability would be one of the determining factors and that gas transmission testing would be a significant part of the thesis. Mechanical tests were the second part of the testing process, providing information regarding package strength and protectiveness during the package’s life cycle. Production efficiency, along with uninterrupted stable production, was another important factor that was taken into consideration. These two issues are sometimes neglected in similar contexts due to their self-evident nature. In addition, materials used in production may have a surprising significance to the production and efficiency. Consistent high quality is also partly based on material selection. All of the aforementioned factors have been documented and the results have been analyzed by the development team at Coveris Rigid Finland. Coveris is now calculating the total finance effects and capacities should the material changes be implemented in practice. There are many factors in favor of switching to polypropylene at the moment. The overall production costs, as well as the environmental effects of resin production are the primary influences for said switch from the converters’ perspective.
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The role gap junction channels play in the normal and abnormal functioning of the vascular wall is the subject of much research. The biophysical properties of gap junctions are an essential component in understanding how gap junctions function to allow coordinated relaxation and contraction of vascular smooth muscle. This study reviews the properties thus far elucidated and relates those properties to tissue function. We ask how biophysical and structural properties such as gating, permselectivity, subconductive states and channel type (heteromeric vs homotypic vs heterotypic) might affect vascular smooth muscle tone.
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Effective processes to fractionate the main compounds in biomass, such as wood, are a prerequisite for an effective biorefinery. Water is environmentally friendly and widely used in industry, which makes it a potential solvent also for forest biomass. At elevated temperatures over 100 °C, water can readily hydrolyse and dissolve hemicelluloses from biomass. In this work, birch sawdust was extracted using pressurized hot water (PHWE) flow-through systems. The hypothesis of the work was that it is possible to obtain polymeric, water-soluble hemicelluloses from birch sawdust using flow-through PHW extractions at both laboratory and large scale. Different extraction temperatures in the range 140–200 °C were evaluated to see the effect of temperature to the xylan yield. The yields and extracted hemicelluloses were analysed to obtain sugar ratios, the amount of acetyl groups, furfurals and the xylan yields. Higher extraction temperatures increased the xylan yield, but decreased the molar mass of the dissolved xylan. As the extraction temperature increased, more acetic acid was released from the hemicelluloses, thus further decreasing the pH of the extract. There were only trace amounts of furfurals present after the extractions, indicating that the treatment was mild enough not to degrade the sugars further. The sawdust extraction density was increased by packing more sawdust in the laboratory scale extraction vessel. The aim was to obtain extracts with higher concentration than in typical extraction densities. The extraction times and water flow rates were kept constant during these extractions. The higher sawdust packing degree decreased the water use in the extractions and the extracts had higher hemicellulose concentrations than extractions with lower sawdust degrees of packing. The molar masses of the hemicelluloses were similar in higher packing degrees and in the degrees of packing that were used in typical PHWE flow-through extractions. The structure of extracted sawdust was investigated using small angle-(SAXS) and wide angle (WAXS) x-ray scattering. The cell wall topography of birch sawdust and extracted sawdust was compared using x-ray tomography. The results showed that the structure of the cell walls of extracted birch sawdust was preserved but the cell walls were thinner after the extractions. Larger pores were opened inside the fibres and cellulose microfibrils were more tightly packed after the extraction. Acetate buffers were used to control the pH of the extracts during the extractions. The pH control prevented excessive xylan hydrolysis and increased the molar masses of the extracted xylans. The yields of buffered extractions were lower than for plain water extractions at 160–170 °C, but at 180 °C yields were similar to those from plain water and pH buffers. The pH can thus be controlled during extraction with acetate buffer to obtain xylan with higher molar mass than those obtainable using plain water. Birch sawdust was extracted both in the laboratory and pilot scale. The performance of the PHWE flow-through system was evaluated in the laboratory and the pilot scale using vessels with the same shape but different volumes, with the same relative water flow through the sawdust bed, and in the same extraction temperature. Pre-steaming improved the extraction efficiency and the water flow through the sawdust bed. The extracted birch sawdust and the extracted xylan were similar in both laboratory and pilot scale. The PHWE system was successfully scaled up by a factor of 6000 from the laboratory to pilot scale and extractions performed equally well in both scales. The results show that a flow-through system can be further scaled up and used to extract water-soluble xylans from birch sawdust. Extracted xylans can be concentrated, purified, and then used in e.g. films and barriers, or as building blocks for novel material applications.
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An alkali-insoluble fraction 1 (F1), which contains mainly ß-glucan isolated from the cell wall of Histoplasma capsulatum, induces eosinophil recruitment into the peritoneal cavity of mice. The present study was carried out to determine the participation of interleukin-5 (IL-5) in this process. Inbred C57BL/6 male mice weighing 15-20 g were treated ip with 100 µg of anti-IL-5 monoclonal antibody (TRFK-5, N = 7) or an isotype-matched antibody (N = 7), followed by 300 µg F1 in 1 ml PBS ip 24 h later. Controls (N = 5) received only 1 ml PBS. Two days later, cells from the peritoneal cavity were harvested by injection of 3 ml PBS and total cell counts were determined using diluting fluid in a Neubauer chamber. Differential counts were performed using Rosenfeld-stained cytospin preparations. The F1 injection induced significant (P < 0.01) leukocyte recruitment into the peritoneal cavity (8.4 x 10(6) cells/ml) when compared with PBS alone (5.5 x 10(6) cells/ml). Moreover, F1 selectively (P < 0.01) induced eosinophil recruitment (1 x 10(6) cells/ml) when compared to the control group (0.07 x 10(6) cells/ml). Treatment with TRFK-5 significantly (P < 0.01) inhibited eosinophil recruitment (0.18 x 10(6) cells/ml) by F1 without affecting recruitment of mononuclear cells or neutrophils. We conclude that the F1 fraction of the cell wall of H. capsulatum induces peritoneal eosinophilia by an IL-5-dependent mechanism. Depletion of this cytokine does not have effect on the recruitment of other cell types induced by F1.
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Laser additive manufacturing (LAM), known also as 3D printing, is a powder bed fusion (PBF) type of additive manufacturing (AM) technology used to manufacture metal parts layer by layer by assist of laser beam. The development of the technology from building just prototype parts to functional parts is due to design flexibility. And also possibility to manufacture tailored and optimised components in terms of performance and strength to weight ratio of final parts. The study of energy and raw material consumption in LAM is essential as it might facilitate the adoption and usage of the technique in manufacturing industries. The objective this thesis was find the impact of LAM on environmental and economic aspects and to conduct life cycle inventory of CNC machining and LAM in terms of energy and raw material consumption at production phases. Literature overview in this thesis include sustainability issues in manufacturing industries with focus on environmental and economic aspects. Also life cycle assessment and its applicability in manufacturing industry were studied. UPLCI-CO2PE! Initiative was identified as mostly applied exiting methodology to conduct LCI analysis in discrete manufacturing process like LAM. Many of the reviewed literature had focused to PBF of polymeric material and only few had considered metallic materials. The studies that had included metallic materials had only measured input and output energy or materials of the process and compared to different AM systems without comparing to any competitive process. Neither did any include effect of process variation when building metallic parts with LAM. Experimental testing were carried out to make dissimilar samples with CNC machining and LAM in this thesis. Test samples were designed to include part complexity and weight reductions. PUMA 2500Y lathe machine was used in the CNC machining whereas a modified research machine representing EOSINT M-series was used for the LAM. The raw material used for making the test pieces were stainless steel 316L bar (CNC machined parts) and stainless steel 316L powder (LAM built parts). An analysis of power, time, and the energy consumed in each of the manufacturing processes on production phase showed that LAM utilises more energy than CNC machining. The high energy consumption was as result of duration of production. Energy consumption profiles in CNC machining showed fluctuations with high and low power ranges. LAM energy usage within specific mode (standby, heating, process, sawing) remained relatively constant through the production. CNC machining was limited in terms of manufacturing freedom as it was not possible to manufacture all the designed sample by machining. And the one which was possible was aided with large amount of material removed as waste. Planning phase in LAM was shorter than in CNC machining as the latter required many preparation steps. Specific energy consumption (SEC) were estimated in LAM based on the practical results and assumed platform utilisation. The estimated platform utilisation showed SEC could reduce when more parts were placed in one build than it was in with the empirical results in this thesis (six parts).
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The mechanical and hygroscopic properties of paper and board are factors affecting the whole lifecycle of a product, including paper/board quality, production, converting, and material and energy savings. The progress of shrinkage profiles, loose edges of web, baggy web causing wrinkling and misregistration in printing are examples of factors affecting runnability and end product quality in the drying section and converting processes, where paper or board is treated as a moving web. The structural properties and internal stresses or plastic strain differences built up during production also cause the end-product defects related to distortion of the shape of the product such as sheet or box. The objective of this work was to construct a model capable of capturing the characteristic behavior of hygroscopic orthotropic material under moisture change, during different external in-plane stretch or stress conditions. Two independent experimental models were constructed: the elasto-plastic material model and the hygroexpansivity-shrinkage model. Both describe the structural properties of the sheet with a fiber orientation probability distribution, and both are functions of the dry solids content and fiber orientation anisotropy index. The anisotropy index, introduced in this work, simplifies the procedure of determining the constitutive parameters of the material model and the hygroexpansion coefficients in different in-plane directions of the orthotropic sheet. The mathematically consistent elasto-plastic material model and the dry solids content dependent hygroexpansivity have been constructed over the entire range from wet to dry. The presented elastoplastic and hygroexpansivity-shrinkage models can be used in an analytical approach to estimate the plastic strain and shrinkage in simple one-dimensional cases. For studies of the combined and more complicated effects of hygro-elasto-plastic behavior, both models were implemented in a finite element program for a numerical solution. The finite element approach also offered possibilities for studying different structural variations of orthotropic planar material, as well as local buckling behavior and internal stress situations of the sheet or web generated by local strain differences. A comparison of the simulation examples presented in this work to results published earlier confirms that the hygro-elasto-plastic model provides at least qualitatively reasonable estimates. The application potential of the hygro-elasto-plastic model is versatile, including several phenomena and defects appearing in the drying, converting and end-use conditions of the paper or board webs and products, or in other corresponding complex planar materials.