• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 79
  • 68
  • 28
  • 16
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 218
  • 74
  • 72
  • 71
  • 61
  • 59
  • 59
  • 49
  • 48
  • 38
  • 38
  • 33
  • 24
  • 23
  • 23
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Projektering av KL-träbjälklag i bostäder med hänsyn till spännvidd och ljudkrav / Planning of CLT-floor in residential housing with regards to span and sound proofing

Namroud, Larsana, Hansson, Ellen January 2020 (has links)
Wood construction has increased in the recent years for apartment buildings consisting of four to five floors. Compared to other building materials, wood has great environmental benefits. For a building in a larger scale constructed in wood, cross-laminated timber, also known as CLT is an option. The technology for CLT originated in Sweden during the 1990s and since then the development has increased. CLT has excellent stiffness and strength properties. The design of a floor in CLT is important for how the building and the environment are perceived indoors. The wooden floor is about five times lighter than concrete, which means that measures are required to meet the sound requirements set by Boverkets building regulations in Sweden. This will affect the span. The aim of the project is to present a knowledge overview of CLT and for floor in CLT up to 9 meters in span, to compete with concrete floor in steel and prefabricated concrete frames. The study includes a quantitative methodology using three different data collection methods. These are literature study, document analysis and calculations. The literature study and the document analysis are based on scientific-and research articles, together with manuals. The calculations are carried out in Stora Enso's calculation program Calculatis by Stora Enso. The program follows Eurocode's design principles. The result of the study shows that a CLT-board with laminated beams gives greater span than just a CLT-board does. The calculation means that the plate must meet the deflection requirement L / 300. Research shows that construction with CLT is increasing and there is great potential to obtain a cost-effective reduction of the carbon footprint and at the same time improve the utilization of natural resources by replacing non-renewable building materials such as concrete and steel with CLT. In order to achieve the sound requirements that are established, the CLT floor must be dimensioned thicker and measures such as additional insulation. By looking at the results, the conclusion is drawn that CLT-floor may grow further to compete with concrete floor in the future. Currently the material is considered useful and environmental for smaller constructions for such as smaller houses, due to the sound insulation problem. For larger constructions with the similar problem can timber-concrete composite be an alternative. CLT-floor reinforced with glulam beams may be considered as a choice for larger and bigger constructions because the span widths increase, and the construction can withstand maximum deflection. The study is limited to mainly considering CLT but also a small amount of concrete and glulam. Vibrations and environmental risks such as moisture, sunlight and fire, are not considered. The calculations the work uses are based on Eurocode 5, dimensioning of wooden structures. Other types of design principles have been excluded.
2

Abstrakt eller konkret verklighet? : Om hur psykologisk distans inverkar på perception

Ahrén, Elin January 2013 (has links)
Förståelsen för andra människor som krävs för lyckade interaktioner, förklaras i attributionsteorierna "Theory of Mind" och "Simulation Theory. Ett vanligt men ouppklarat fenomen är det fundamentala attributionsfelet, där beteende felaktigt attribueras till inre generella egenskaper. Fenomenet reflekterar en abstrakt mental konstruktion i enlighet med Construal Level Theorys antagande om hur psykologisk distans inverkar på perception. I en modifierad Attitude Attribution Paradigm modell undersöks om spatial distans påverkar det fundamentala attributionsfelet och om skillnader föreligger mellan kvinnor och män. Kort/lång spatial distans primades genom en kontroversiell text, via information om dess kompositionsplats, som fungerade som underlag för bedömning av skribentens åsikt. En variansanalys visade ingen signifikant effekt av spatial distans, inte heller någon skillnad mellan kvinnor och män. Resultaten kan ha påverkats av den modifierade undersökningsmodellen, vilken kan ha medlat en implicit antydan om en uttryckt åsikt.
3

Projekt objektu dřevostavby

Václavek, Lukáš January 2015 (has links)
This thesis deals with drafting a residential building wood based on existing supermar-ket which is located on a plot placement - concealed in the village Omice. According to the location of the parcel has been designed layout and shape solutions objectively. The next step was to propose design solutions and their compositions with the assessed thermal solution. Peripheral construction of residential house was assessed according to ČSN 730540 proposed residential building study documentation was elaborated in abo-ve plans of the level of building permits. Furthermore, the study has been completed and the accompanying technical report.
4

Polyfunkční bytový dům s nosnou konstrukcí ze dřeva

Uchytil, Oto January 2013 (has links)
No description available.
5

Novostavba administrativní budovy v systému dřevostavby

Holčák, Martin January 2019 (has links)
The final thesis deals with the topic of fire safety of buildings in the Czech Republic in the theoretical part, and later in the practical part presents the project of a wooden-structure administrative building placed within a specific plot in the city of Brno. The project documentation used, regarding its content and implementation, accords with the project documentation related to the construction process set out in the decree 499/2006 Sb, as amended. The theoretical part only relates to selected criteria of fire safety of buildings connected to wooden-structure buildings projects in the Czech Republic and points out a potential normative limitation of the construction of these buildings, especially with regard to the criterion of fire protection height. The thesis also outlines the conditions of typically high-rise wooden buildings construction abroad where the storey number limitation differs significantly from the one in the Czech Republic. Methodologically, the thesis focuses on the method of partial calculations leading to the preparation of a fire safety construction plan. The required principles and methods of calculations are usually the subject of the often-referenced norm ČSN 73 0802 PBS – Non-production premises. The result of the thesis is a comprehensive take on the individual project of an administrative building designated to host a design company. The result consists in gradual satisfaction of all legislative and normative requirements related to the designing of this building type. The thesis’ content points out the interconnectedness of the fire safety topic with the design of the construction and inner organisation, and plot-placing of the building.
6

Composting of Cross Laminated Timber (CLT) Sawdust

Bahsi-Kaya, Gulbahar 10 August 2018 (has links)
A three-month study evaluated composting of cross laminated timber (CLT) sawdust amended with 10% and 20% chicken litter. Moisture was provided by rainwater or deionized water depending on the precipitation. The contents in the containers were mixed once or twice a week for aeration. Samples were collected at 0, 45, and 90-day intervals to measure weight loss, moisture content, pH, compost maturity, microbial count, and carbon-to-nitrogen ratio. Results indicated that composted CLT with 20% chicken litter had much higher weight reduction than others at day 45 and 90. Treatments with 10% and 20% chicken litter had a higher initial pH than controls and showed a slow increase near to neutral 7 by day 90. The germination rate of radish seeds to measure the compost maturity showed that composted CLT with 20% chicken litter had significantly higher germination rate than the others at days 45 and 90. A greenhouse study of composted material showed also that the 20% treatment could be used as soil amendment due to its excellent C/N ratio but appears to be unsuitable for container media. Longer composting time is suggested for CLT sawdust to be cured and used for potting media.
7

Evaluation of the durability of mass timber products against termites (Reticulitermes spp.) using choice testing.

McGinnis, Jazmine A 01 May 2020 (has links)
Mass timber products are rapidly growing in fascination and popularity across the North American construction market, in which wood products are tested for durability and resiliency according to standards set by the American Wood Protection Association. Presently, the American Wood Protection Association (AWPA) E1 Standard calls for a test sample size of 2.54cm x 2.54cm x 0.64cm, which may be too small to encompass the large spacing between the bond lines of CLT, a multilayered mass timber product composed of layers of kiln-dried lumber alternating in grain direction. The objective of this study was to evaluate the resistance of untreated CLT against subterranean termites (Reticulitermes spp.) found in the southeastern United States using two-sample choice testing and extend the AWPA E1-17 Standard to accommodate the larger building material. Choice-testing methods were evaluated over a 4-week period for mass loss, visual rating, mold formation, and termite mortality.
8

Diagonal compression of Cross-Laminated Timber / Diagonal hoptryckning av korslimmat trä

Turesson, Jonas January 2016 (has links)
Twelve blocks of Cross Laminated Timber (CLT) were built, tested and simulated. Three types of blocks with different laminate directions in the middle/second layers were used: 0/30/0, 0/45/0 and 0/90/0. Simulations with three-dimensional quadratic orthotropic linear elastic finite elements were conducted. The goal was to compare tested in-plane shear stiffnesses for CLT blocks made from Norway Spruce (Picea abies) boards of C24 quality with a finite element (FEM) simulated block stiffness. Three-layer CLT were studied with block dimensions of 600 x 600 x 45 mm. The first and last layer laminate directions were assumed to be 0○. The middle layer laminate directions were 30○, 45○ and 90○. A 1 mm gap was assumed between the side edges. The glued contact surfaces were assumed to be perfectly glued with rigid glue in the simulations. In the practically tested blocks a PVAc D2 classified glue was used. All blocks were simulated and tested in the same loading arrangement as the practical test set-up. The blocks were compressed in the diagonal direction. Blocks of 0/30/0 and 0/45/0 were compressed twice, once over each diagonal. The 0/90/0 blocks were compressed over one diagonal. A total of 19 practical compression tests was performed; in all cases, the displacements were measured in the force- and orthogonal direction. The stiffest loading case, measured in the force direction, was the loading arrangement 0/45/0-A. The weakest loading case, measured in the force direction, was the loading arrangement 0/30/0-B. The same result could be concluded from the FEM simulations. The calculated stiffness in the loading direction was between 1.21 – 1.87 times larger than the measured stiffness. The models pressed in the “weakest” direction gave the largest difference between the simulated and measured stiffness.
9

Impact Bias och Empathy Gaps : - en studie om skillnader mellan känslor och preferenser.

Marshall Shedden, Anna January 2012 (has links)
Syftet med föreliggande studie var att försöka reda i litteraturen kring två välkända begrepp inom Affective Forecasting nämligen Impact Bias, som innebär att människor har en tendens att överskatta i vilken utsträckning de kommer att uppleva en viss känsla i en framtida situation än vad som senare visar sig vara fallet, och Empathy Gaps, som innebär att människor har en tendens att underskatta i vilken grad känslotillstånd kommer att påverka deras preferenser i en framtida situation samt pröva dessa begrepp i en och samma enkätundersökning. Etthundra sextiotvå studenter, slumpvist uppdelade i två grupper, Känslogrupp och Preferensgrupp, deltog frivilligt i undersökningen. Enkätundersökningen var en mixad design med grupp (känsla kontra preferens) som mellangruppsfaktor och förtest kontra eftertest som inomgruppsfaktor. I studien visade samtliga gruppers resultat i linje med Impact Bias teorin, dvs. att deltagarna i både Känslogrupp och Preferensgrupp skattade lägre i eftertest (actual) än pretest (forecasting). Resultatet diskuteras bla. utifrån Construal Level Theory, CLT. Förslag på vidare forskning ges.
10

Grammar sequencing in the communicative Arabic classroom : students’ written production

Kauffman, Alan Ray 12 September 2013 (has links)
Over the course of the past 20 years, the rise in popularity of communicative language teaching as an alternative to traditional methodologies in Arabic-language pedagogy has led many within the field to re-examine their instructional priorities and methodological tenets. In general, traditional pedagogical approaches in the field of Arabic-language instruction dictate front-loaded presentation of grammatical concepts. The premise of communicative language teaching, on the other hand, is based on the primacy of successful foreign language interactions, where students are sequentially provided the grammatical concepts that are required to accomplish specific and targeted communicative functions and tasks. Concordantly, the instruction of grammar concepts that are deemed surplus to the requirements of level-appropriate interactions is deferred until the student has become linguistically prepared to incorporate and effectively utilize more complex grammatical structures. This thesis presents the results of a study of students’ spontaneous and planned written production in Arabic focusing on the production of dual and feminine plural forms, which have been strategically delayed in the sequence of grammar presentation. Additionally, individual interviews with both students and instructors were conducted to gather their impressions of, and strategies for, dealing with the sequence of grammar presentation in which these concepts are delayed. Results indicate that students who were not presented detailed instruction regarding the dual and feminine plural constructs early in their pedagogical sequence displayed level-appropriate patterns of avoidance and generalization in their early language production. As students progressed through the third-year courses and into post third-year courses, they displayed high levels of successful incorporation of the Modern Standard Arabic dual and feminine plural forms in their written production. With their successful conceptual uptake, the learners demonstrate their ability to acquire grammatical concepts despite the sequential delay in presentation thereof. Interview results show students’ and instructors’ awareness of the intent and focus of the pedagogical sequence. Based on their personal experience in studying and/or teaching Arabic, and despite instances of frustrations or challenges arising from the delay in grammar sequence, all interviewees expressed their support and endorsement of the methodology. / text

Page generated in 0.0261 seconds