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  • 751.
    Welander, Ulrika
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design. Bioenergi.
    Hydrogen peroxide degradation by immobilized cells of alkaliphilic Bacillus halodurans2006In: Biocatalysis and Biotransformation, ISSN 1024-2422, Vol. 24, no 3, p. 215-222Article in journal (Refereed)
    Abstract [en]

    Whole cells of Bacillus halodurans LBK 261 were used as a source of hydrogen peroxide. The organism B halodurans grown at 55 C and pH 10, yielded a maximum catalase activity of 275 U g-1 (Wet wt.) cells. The catalase in the whole cells was active over a broad range of pH with a maximum at pH 8-9. The enzyme was optimally active at 55 C, but had low stability above 40 C. The whole cell biocatalyst exhibited a Km of 6.6 mM for H2O2 and Vmax of 707 mM H2O2 min-1 g-1 wet wt. cells, and showed saturation kinetics at 50 mM H2O2. The cells were entrapped in calcium alginate and used for H2O2 degradation at pH 9 in batch and continuous mode. In the batch process, the immobilized prepration containing 1.5 g (wet wt.) cells could be recycled at least four times for complete degradation of the peroxide in 50 ml solution at 25 C. An excess of immobilized biocatalyst could be used in a continuous stirred tank reactor for an average of 9 days at temperatures upto 55C, and in a packed bed (PBR) for 5 days before the beads started to deform.

  • 752.
    Welander, Ulrika
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Forss, Jörgen
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Decolourization of reactive azo dyes with microorganisms growing on soft wood chips2009In: International Biodeterioration & Biodegradation, ISSN 0964-8305, E-ISSN 1879-0208, ISSN 0964-8305, Vol. 63, p. 752-758Article in journal (Refereed)
    Abstract [en]

    The decolourization of a mixture of 200 mg/l each of Reactive Black 5 and Reactive REd 2 dye was studied in batch experiments using microorganisms growing on forest residue wood chips in combination with or without added white-rot fungus, Bjerakndera sp. BOL 13. The study was performed as a first stage in the development of a relatively simple treatement process for textile wastewater, designed to work in developing countries. Forest residue wood chips contain a mixture of fungi and bacteria which is an advantage when complex molecules should be degraded. The wood chips furthermore provide the microorganisms with carbon source which make the addition of e.g. glucose unnecessary. The results showed that the microorganisms growing on the forest residue wood chips decolourized the mixture of the two dyes; adding extra nutrients approximately doubled the decolourization rate. The time needed for decolourization was approximately 18 days when nutrients were added. Lignocellulosic material is complex and so were the analysis, microorganisms were therfore transferred to ordinary soft wood chips from forest residue wood chips, Decolourization was measured with spectrophotometer an in order to determine intermediates HPLC was used.

  • 753.
    Wernius, Stina
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Vaggan Liten: - det nya vaggandet.2007Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Denna rapport innehåller en sammanfattning av ett examensarbete för kandidatexamen vid Växjöuniversitet, Institutionen för Teknik och Design. Projektet utfördes under 10 veckor våren 2007.

    Projektet gick ut på att undersöka det traditionella sättet att söva sitt barn. Vaggan som möbel har under det senaste åren försvunnit mer och mer från marknaden och ersatts med andra lösningar.

     Syftet med projektet var att formge och ge förslag på en ny sänglösning med tillhörande sängtextil utifrån föräldrars önskemål, specialisters råd och material anpassande för ett litet spädbarn.

     Målsättningen var att intressera brukaren för det nya vaggandet.

     Resultatet blev en variant av en vagga, med stort fokus för gynnandet av barnets välbefinnande.

  • 754.
    Wiberg-Bocek, Sebastian
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Energisparande åtgärder för uppvärmning i en 70-tals villa: Energy-saving measures for heating in a 70-century detached house2008Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [sv]

    Detta examensarbete på 15 högskolepoäng har som syfte att undersöka några åtgärder för minskade uppvärmningskostnader. Då det byggs mycket nytt idag får man inte glömma bort alla befintliga byggnader. Det första steget mot minskad energianvändning är att minimera uppvärmningsbehovet. I detta arbete har vissa utvalda åtgärder beräknats på en 70-tals villa för att se vad man sparar in. Genom mätningar och information från villans byggnadsbeskrivning beräknas byggnadsdelarnas U-värden. Köldbryggor beräknas med datorprogram. Genom vetskap om ortens gradtimmar kan de totala energiförlusterna beräknas, som är transmissionsförluster, köldbryggor och ventilationsförluster. Tillskott från gratisvärme räknas in.

    Åtgärder som beräknas är sänkt inomhustemperatur, som är en enkel lösning och inte kräver någon investering av pengar. Sänker man temperaturen i denna villa 1 ºC så sparar man ca. 9% energi varje år, vilket blir 2158 kr per år. Tilläggsisolering av vindsbjälklag är också relativt enkelt. För att uppnå en isoleringstjocklek på 500 mm används lösull. Denna åtgärd ger besparing på 2193 kr varje år vilket ger en återbetalningstid på knappt 6 år med arbete och materialkostnader inräknat. Att byta till nya fönster kostar desto mer och är inte lönsamt om de befintliga fönstren inte är i behov av att bytas ut. De fönster som används är 3-glasfönster med isolerruta. Med ett U-värde på 1,2 fås den lägsta återbetalningstiden på 24 år. Att byta till ett ventilationssystem av typen FTX har för denna villa en återbetalningstid på 10 år vilket är en rimlig åtgärd. Det förutsätter då att ventilationsaggregatet är i drift hela året och inte kräver någon eftervärmning av tilluften.

  • 755.
    Wiemer, Marcus
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Lidby, Per
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Tillgänglighet på rastplatser: en fallstudie2009Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report is about accessibility at rest areas. We have examined the aisles and furniture of seven rest areas with a focus on accessibility for disabled persons. At the end of the report, we provide suggestions on how some of the weaknesses we have discovered can be addressed.

  • 756.
    Wieslander, Ida
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    A model to prepare and secure an implementation of a performance measurement system: A case study2008Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    What you do not measure you cannot control and what you do not control you cannot improve, implies that measurement is a pre-requisite for improvements. Especially for Small and Medium Sized Enterprises (SME) an implementation of a Performance Measurement System is mostly critical in terms of the fact that SMEs often is restricted of limited resources, lack of strategic thinking, lack of formal planning, as well as a reactive mentality. A model to prepare and secure an implementation of a performance measurement system at SMEs, has been developed, tested and validated through a single case study at a small enterprise, that is a well-renowned refiner of castings. The model is constituted by phases and steps supporting the advantages as well as over bridges the most common disadvantages for SMEs. The significant advantages on behalf of SMEs; loose structure, informal operating practices and lack of bureaucracy are reinforced by integrating the project and especially the output such as specification of requirements, new routines, improvement groups and forums within the organisation and in turn over bridge the disadvantages of limited resources and lack of formal planning. Identification and prioritisation of strategic objectives is the first step and creates a foundation of a continuous strategic thinking, which often SMEs are lacking, and in turn navigate the company in the right direction in order to maximise the utilisation of resources and consequently increase the profitability.

  • 757.
    Wilander, Stina
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Byggnadsekonomi: En jäförelse ellan passivhus och konventionella hus2008Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Along with increasing energy costs, and effection on the environment, it is more and more important to save

    energy. One thing we can do is to build so called passivehouses, as the houses takes up almost 40 % of the

    total energy, spent in Sweden.

    Increasing production costs stands in the way of building low-energy buildings. Therefore it’s important not

    only to consider the cost of building the house, but also to look at what the yearly costs will be. If more money is

    spent, during the production of the house, at extra isolation and more effective installation systems, the yearly

    costs will decrease. That leads to the conclusion that the house is repaid in a certain amount of years. How long

    it takes and which factors it depends on the most, will be revealed in this paper.

    One of the conclusion is that the passivehouses works, and the extra money spent when building the house,

    is repaid in about 16 years. The repayment time, depends on a huge number of scenarios, but the money will

    still be repaid, it’s just a matter of time

  • 758.
    Winton, Marcus
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Engström, Anders
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Värmeisoleringsberäkningar av flerbostadshus: byggda 1996-20052009Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In 1987, a new law of building became effective, Plan- och bygglagen(PBL). The building committees' inspection of construction sites and documents decreased. The final quality of the buildings now depended in greater extent on the property developers and the contractors internal control. Due to different interests within the municipality and because of strong connections between property developers and contractors, it is not always a matter of course that e.g. the inspection of thermal insulation and energy housekeeping is executed in a satifactory fashion. With the above in mind we examined four multi-dwelling buildings, two in municipality of Värnamo and two in Kristianstad. We examined if the buildings comply with the thermal insulation requirement according to BBR (the swedish building code) and which requirements that were stated in the different projects documents of inspection.Only one out of the four buildings complies with the requirements according to BBR. In the municipality documents there are requirements of thermal insulation calculations but there are no documents that verifies that such calculations have been executed.

  • 759.
    Witten, Thomas
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    En lättviktsskiva i massivt trä för möbelindustrin2006Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Light-weight panels to the furniture industry have been a well documented task in line papers the last

    time. This work describes and studies a new type of a construction of a light-weight panel in massive

    wood. The light-weight panel in massive wood is built like a sandwich construction in three levels. The

    outer layers are made of 6 mm thick massive wood glue panels and the core material by profiled

    distances. Material is pine and the light-weight panel has a density of 310–332 kg/m3. Out of contacts

    with selected producers and users of board materials, as in combination with tests, has this construction

    been checked and purposes for improvements have been stated. The original distances, which were put

    together by two parts including a centre hole have been replaced by a type of distance in massive wood

    with a similar profiling. In contacts with companies has a slightly reserve been shown to finger-joints

    on visible surfaces, which the originally prototype had. I conclusion with this presents a suggestion for

    different kinds of qualities for visible and not visible respectively and hidden surfaces in conclusion

    with the investigation of aesthetically and production technically aspects.

  • 760.
    Witten, Thomas
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Nya produktionsformer inom möbelindustrin: Ett pilotprojekt hos Spaljisten AB2007Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The master thesis has been realized in direct contact with the host company Spaljisten AB, Åseda Sweden and

    is dealing with the production philosophy Lean production and the production concept TPM. Main object for the

    studies was a machine line for processing of furniture details (Homag VI). An actual condition analysis has been

    done to determinate stop reasons and the OEE (35.9 %). In all classes of stop reasons occur mainly short stops

    (81 %) those indicate chronic problems in the line. Together with the employees of the line Homag VI was a fault

    analysis done (Ishikawa diagram). Actual condition analysis and fault analysis can generate a potential of

    improvement of 33 % for increased availability. Furthermore was a SMED analysis done where the main work of

    analyzing was done together with the employees of the line. By a deeper analysis a classification of IED and

    OED respectively could be done including even simplifications that led to a reducing of time for set up of 55

    minutes and 43 seconds. Also tools like the Lean start up and communication, operator’s maintenance, 5S,

    constant improvements have been studied. An efficiency analysis of the kaizen groups was done that shows that

    a lack of motivation exists among the employees. The main explanation for this is that the company does not

    have a plan for the organisation structure and neither a plan for implementation of new production forms. The

    work contains an extended summary in English, German and Swedish.

  • 761.
    Wreinerth, Joachim
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Hjalmarsson, Joel
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Undersökning av vindlaster på en parabolantenn2009Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Vi fick i uppdrag av Swepart Transmission AB att med lämpliga metoder beräkna vindlaster på en godtycklig parabolantenn samt att konstruera en växellåda för att positionera den. Vi insåg i ett tidigt skede att vi var tvungna att ta fram vindlastfaktorerna laborativt. Och på grund av den begränsade tiden var vi tvungna att fokusera endast på vindlasterna på en parabolform.

    Först uppskattade vi de maximala vindlaster som kunde uppkomma för att kunna dimensionera vår mätram. Sedan beräknade vi lastcellerna och konstruerade erforderlig elektronik. För att simulera vind monterades parabolen och dess mätram på ett fordon, mätningarna utfördes sedan på Uråsa flygfält. Efter mätningen kunde vi fastslå de sökta vindlastfaktorerna och deras ekvationer

  • 762.
    Yang, Yong
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Pop, Claudiu
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Improving the quality of products during production by applying different quality control tools2005Independent thesis Advanced level (degree of Master (One Year))Student thesis
    Abstract [en]

    In the competing market every company tries v to have good quality on their product or to be a step ahead of their competitors. To be able to do this, many things have to be taken in consideration. The case company wanted to improve their quality on a product called PX 21, which is a pellet burner. They did not really know how they should proceed to improve its quality. The authors of this thesis helped them find the measuring quality tools needed for this problem and they also showed the case company how to use them. The biggest problem with the PX 21`s quality was that the radiator broke down to often. To fix this problem the authors suggested the case company to use the 7 basic quality control tools to measure their quality and at the same time improve it. An investigation has also been done by the authors in form of calling the case companies retailers to get their opinion about the PX 21. The result was that the company has already a very high customer service level, up to 90%. But they could improve their quality even more if they would just use the 7 quality tools suggested by the authors, and looking at the recommendations given.

  • 763.
    Yassin, Karmel
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Produktionsuppföljning på WilloMaskin AB2007Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose with this bachelor thesis is to identify risks and insufficiencies concerning the production at WilloMaskin AB. The project is limited to only 4 machines, where theories as “OEE” (overall equipment efficacy) should be illuminated and analyzed. The theory of “Single Minute Exchange of Die” is also presented.

    The method used in this project is mostly based on qualitative studies but also quantitative studies are presented. Information has been gathered from Willo Maskin ABs own calculations, the university library of Växjö and electronical sources. The studies have been made through observation and notes of the production process at the workplace. Routines have been checked and discussions with people involved in the process have been passed. The observation also included machine stand still measurement and OEE calculations. The measuring for each machine under a time period shows the lack in the production progress and the methods used. The results show that the machine adjustment is the part of the process that requires the most production time. Discussions with machine operators prove that a lot of them don’t know how to handle new machines. However, the machines work very efficient when they work. It takes short adjustments and further education of operators to increase the availability. The introduction of different production follow-up systems is necessary to be able to measure, and in a long term even reduce the reasons of standstill.

  • 764.
    Yderborg, Anna
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Lundahl, Jacob
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Structuring of maintenance data for identifying and elimination of problem machines2004Independent thesis Advanced level (degree of Master (One Year))Student thesis
    Abstract [en]

    Manufacturing companies of today are using maintenance system to keep good historical information about their machines, to make sure that preventive maintenance is preformed and to keep track of breakdowns. Many companies are doing this but the data quality is often very varying, which leads to that the information in this system is useless. The problem arises because the maintenance technicians finds the reporting of a failure too time consuming. To solve this problem we have created a model for information input that will facilitate the report of a problem and structure the data. This will lead to that the data will become searchable and useful for decision making. The model has been created during a case study by evaluating the existing data and validating the model at a case company.

  • 765.
    Zadig, Lennart
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Enochsson, Anders
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Pelletring som marginalaffär för mindre sågverk/hyvlerier: en studie av 5 anläggningar i Småland2007Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study is about pelleting as a possible profitable marginal business for minor saw-mills and planing mills. It has been carried out through in depth interviews of five different minor saw-mills and planing mills in Småland. These businesses are different themselves but all of them have invested in pelleting for financial and environmental reasons.

    The study shows that pelleting is profitable but also that a number of conditions must be fulfilled to reach profitability in the long run. The most important success factor is long-term access to raw material (dry chip) but the production process also demands a high interest and knowledge in wood and processing technology. This is due to the fact that the process is very complex and also depending on external circumstances like humidity, coldness and dryness. Due to this complexity and that the demand of manpower is rather high one should aim for producing at least a certain minimum quantity.

    The study also shows that there are a couple of other factors that are needed to be fulfilled to reach the profitability that the pre-calculation indicates.

    If most of these conditions are fulfilled there are very good possibilities that pelleting over a business cycle can contribute to an improved profitability for the type of businesses that have been studied.

  • 766. Zander, A
    et al.
    Hidemark, O
    Thörnqvist, Thomas
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Trä som byggnadsmaterial: -tekniska anvisningar2007Report (Other academic)
  • 767.
    Zander, Carin
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Evaluation of the released thermal power in wood pellets2006Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This Degree Project has been done at Växjö University, department of bioenergy technology and discusses the released thermal power in wood pellets. The purpose of the project is to investigate if two new types of wood biofuels (pellets) are more or less reactive than the pellets previously investigated at Växjö University. To measure the released thermal power, an isothermal calorimeter with eight channels has been used. To see how the microbial activity is influenced, the pellets have been stored under various conditions with focus on temperature and metal.

  • 768.
    Zeeshan, Muhammad
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Djaya, Irawati
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    A model to support development of procedural description to improve the quality control of production in different cultures: A case study of a Swedish toys vendee and its outsourcing2007Student thesis
    Abstract [en]

    The main purpose of this thesis is to develop a model for designing a quality control procedural description with respect to cultural differences. This project is conducted at the case company. The problem in the case company is to analyse the existing procedural description of quality control to develop a model to improve the quality control of production with respect to different cultures. The authors visit the case company to collect essential information to accomplish the thesis, face-to-face user interviews, Question & Answer via email. The knowledge gained on different quality tools during studies at School of Technology and Design (Terotechnology) for the basis of this research. The plan of this thesis uses the different quality tools and techniques to solve the problem by analyzing, mapping the existing processes. The analysis is based on theoretical and empirical facts, also different quality tools like process mapping, cause & effect diagram and flowchart are use to identify the problem and relevant suggestions have been proposed to improve their current situation. In the results and conclusions the authors explain a model for designing a quality control procedural description. The authors believed by implementing the suggested improved model company can address their quality issues, which will improve the productivity to a greater extent and enable them to achieve their goal of continuous improvement.

    Communication is main factor in this thesis. In the case company there is such as no main problem of low or bad quality in the product. Occurrence is more important to develop good relations with the suppliers. Continuously repeat of the specification and demand over & over again is very important for clear communication between buyer & seller as well as feed back and follow up of the order from both parties.

  • 769.
    Zeng, Xiong yu
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Ren, Su Xin
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Omar, Sabri
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Vertical Displacements in a Medium-rise Timber Building: Limnologen in Växjö, Sweden2009Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The history of timber buildings in Sweden entered a new era when the authorities decided to lift the ban on constructing more than two-storey timber buildings in Sweden. This change in legislations has contributed to the emergence of timber construction during the last decade. The Cross Laminated Timber (CLT) has become recognized as a new technology that used correctly in construction gives strong and reliable structures. The building material is gaining more credit day by day mainly due to the stiffness and strength it proved throughout the tests in projects where it was used.

    One of the projects that used CLT as load bearing elements was Limnologen in the city of Växjö 500 kilometres south of Stockholm. In this project, a system of CLT floors as well as CLT walls has been used. One of the challenges related to medium-rise timber buildings in general is to calculate and take account of the vertical displacement of the whole building. The sources for the displacements are instantaneous elastic as well as time dependent. In this thesis we are introducing two evaluation methods for the vertical displacements in Limnologen. The first is the experimentally measured vertical displacement that was performed by a group of researchers from Växjö University, and the second is a Finite Element Model simulating the vertical displacement according to the factors and parameters thought to be important to be included in the modelling. The output of the simulation was to be compared with the experimentally obtained values. Simulation is an important way to predict the vertical displacement in future CLT buildings. All modelling were done using the finite element software Abaqus.

    The Abaqus model of the Limnologen building consists of six wall elements from six storeys. The modelled wall elements are the wall elements that the vertical displacement devices were installed on. The reason for this is to get a better picture of how the results from the model would yield in comparison to the site measurements. The floor itself and the sylodyn used in the interface between wall and floor were also modelled.

    The data collected from the site were processed in the software Matlab. Several graphs were attained out of the data processing. The most important graph is the one that include both the total relative displacement and the equivalent moisture content in the CLT. The equivalent moisture content was calculated from the measured temperature and relative humidity.

    In this thesis it is concluded that a simulation can accomplish an acceptable reliability with respect to the vertical displacements. The shrinkage factor has played a vital role in simulation of the displacements. The maximum displacement obtained from the measurements was 21 mm while the maximum displacement gained from the simulation based on three different assumptions was 35 mm, 33 mm, and 17 mm respectively with the similar displacement pattern. The difference in the results can partly be explained by the assumptions used for the equivalent moisture content and local coordinate system of the CLT layers. In the simulation the moisture content was assumed to be equal over each layer of the CLT-panel. The first two assumptions were formulated due to the amphibolous grain of the middle layer of the CLT-panel which was considered having effect on the vertical displacement. The third assumption was formulated due to the glue layer between the wood layers of the CLT-panel which was considered having effect on preventing moisture diffuse from one layer to another layer. In reality it is questionable if the moisture content is varied in the different layers of the CLT-panel. The diffusion of the moisture content hasn't been taken into account.

  • 770. Ziethén, Rune
    et al.
    Bengtsson, Charlotte
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Machine strength grading – a new method for derivation of settings2009In: CIB-W18 Timber Structures, Zürich, August 2009: Paper 42-5-1 / [ed] Blass, H J, Karlsruhe, 2009Conference paper (Refereed)
  • 771.
    Zubair, Ghaith
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    El-Thalji, Idriss
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    A model for analysis and design of an integrated operations management system using systems engineering approach: A case study2007Report (Other academic)
    Abstract [en]

    Background: Generally, operation management includes a set of complicated systems interfacing each other. Most important systems which impact and impacted by the operations management system are production management system and maintenance management system. But to treat the interfacing losses has been difficult as interact and partially overlap each other. In this study, case-operational system was treated with developed model that analysis and design integrated operational system in order to make it easier and cost effective to manage.

    Methods: A model was developed based on latest literature survey work using systems paradigm methodology and systems engineering approach.

    Results: Among five analysis techniques, four types of interfacing losses were identified, seven requirements were extracted, nine conceptual solutions were generated, one of them was selected and based on it the integrated operational management system were designed.

    Conclusions: The results suggest that the operational system in case-company shall be integrated by organization management, process management, and control management, in addition to data management.

  • 772.
    Zuna, Zarko
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Utvärdering av pelletsförgasning för glassmältning: Fullskaleexperiment vid Kosta glasbruk våren 20042004Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The negative environmental impact of the consumption of fossil fuels has led to an increased claim for a wider use of renewable energy sources. Biomass appears as a particularly promising option. This project demonstrates the possibility to heat glass furnaces with gas from biofuel gasification combusted without visible flames. By better technique you can both retain production and reduce nitrogenoxide emissions with economical benefit. The biofuel doesn’t contribute to the greenhouse effect. A part of the whole project is the experiments performed on June 1st 2004 in Kosta glass- factory, total 7 hours and 50 minutes. A major effort of this diploma work is to evaluate mass and energy balances of the down – draft fixed bed gasifier used in the experiments.

  • 773.
    Åkesson, Ulf
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    En jämförelse mellan pallsystem i olika material: -kostnader, hygien och miljö2004Independent thesis Basic level (degree of Bachelor)Student thesis
    Abstract [en]

    The purpose with this diplomawork is to compare EUR-pallets, single trip pallets made of wood and the plastic pallet Everest within the Swedish food industry regarding costs, hygiene and environment.

  • 774.
    Ödlund, Lars-Olof
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Varför sågas så lite björk i Sverige?: Why isn't more birch wood being sawn in Sweden?2009Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Summary in English

     

    Sweden is a forest country with a standing wood balance of more than 3 000 million m3sk. Pine and spruce are dominating species but there is also a wood balance of some 420 million m3sk of birch. Birch is offering excellent timber properties and is well matching both pine and spruce with the exception of its sensitivity to moisture. Despite of this, quite small quantities of birch timber are being used in Sweden. Most birch wood being cut is used for the production of paper and pulp (95%). Although the birch tree is an old species in Sweden it was during the 2000th century until the end of the 1970s treated as a weed and was struggled with by means of herbicides. Subsequently Sweden lost knowledge and experience in how to deal with this wood which in turn leads to a poor quality of now existing clumps of birch trees. Compared to coniferous trees little research has been done of broadleaf trees but it’s anyhow known that the clearing and thinning of birch trees have to be stricter than that of softwood. Birch trees have an interesting potential with a shorter production cycle than pine and spruce. Used for timber the yield for the forest owner could be quite interesting. Broadleaf trees are also playing an important role to improve the overall environment.

     

    To increase the use of birch wood more information about this specific timber has to be spread to all parties concerned. That involves owners of forest land, silviculture, sawmills, industry and distributors. Activities along the chain of actors have to be market oriented and include economic incentives for parties concerned. To be able to increase the volume of birch timber used new areas of deployment have to be found outside the traditional production of furniture etc. An interesting area is then the building industry.

  • 775.
    Östgård, Katarina
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Ström, Neta
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Hantverksteknik F och gesällprov, finns det likheter?2009Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Det här arbetet är en undersökning som baseras på en dokumentanalys. Analysen är gjord på dels Hantverksteknik F och gesällbrevsprovet för frisör respektive låssmed. I uppsatsen jämförs dessa styrdokument med gesällbrevet. Finns det någon samstämmighet mellan dessa olika styrdokument? I resultatet framgår att det finns en korrelation mellan skolans styrdokument som i detta fall är Hantverksteknik F och gesällbrevsprovet för frisör och låssmed. Samtidigt syns det i resultatet att det finns en diskrepans och i och med det en möjlighet att välja för varje karaktärsämneslärare hur man vill rikta undervisningen. Antingen styr man mot gesällbrevsprovet eller inte. Generellt sett ökar önskan från kunder att det skall finas någon form av kompetensbevis och då är gesällbrevet ett sådant.

    Nyckelord: frisör, låssmed, gesällbrev, styrdokument och dokumentanalys.

  • 776.
    Özdemir, Gonca
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Optimering av biogasproduktion från gödsel2009Independent thesis Basic level (degree of Bachelor), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

                          In this study, the bioconversion of manure and silage to biogas by an anaerobic digestion process in batch reactors was studied. Biogas is a valuable alternative energy source, mainly in rural areas. The main aim for the environment is to use biogas as a fuel instead of crude oil or natural gas. In this study, two different parameters were studied to observe the changes in methane productivity. The first three reactors were shaken once per week and the following three reactors were shaken 5 times per week. The results showed that mixing has no major effect on the methane production yield. In the second six reactors a mixture of 1% and 3% silage was added and the results were recorded. When the data from the reactors with just manure was compared to the reactors with 1% and 3% silage, it was seen that the silage increased the production rate and total gas produced. The process stabilization took a long time for digestion with the 3% silage possibly caused by release of too much fatty acids.

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