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  • 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.
21

Sledování vlivu keramické vazby na vlastnosti izolačních žáromateriálů / Monitoring the Influence of ceramic bond on the properties of insulating refractory materials

Friček, Jakub January 2013 (has links)
Thermal insulating refractories are an integral part of each thermal unit since they reduce its energy consumption. The current phenomenon of saving in both environmental and financial aspects reflects in searching for such possibilities to produce at lower manufacturing and material costs. One of the possible ways is to valorise waste materials. The theoretical part then deals with the division of refractory materials, classification of thermal insulation refractory materials and manufacturing technologies. The experiment is focused on the production of insulating refractory materials made from plastic dough with a possibility of using sawdust and materials made by pressing mixture moist, with a focus on coal bottom ash. Both of these technologies will be tested for the possibility of modification by using mixed clays and of increasing the strength by using clays with lower sintering temperature.
22

Resposta de células pulpares a biomodificação do colágeno pela acroleína e seu efeito sobre a resistência máxima a tração da matriz dentinária e resistência da união resina-dentina /

Gomes, Lays Nobrega. January 2020 (has links)
Orientador: Josimeri Hebling / Resumo: Objetivo: Investigar a citotoxicidade transdentinária da acroleína (ACR) sobre células pulpares e a resistência máxima à tração (RMT) da matriz dentinária e resistência da união (RU) resina-dentina após a biomodificação do colágeno dentinário por esse agente promotor de ligações cruzadas. Métodos: Discos de dentina (0,4 mm de espessura) foram obtidos de molares humanos hígidos e adaptados em câmaras pulpares artificiais. Células MDPC-23 foram semeadas na superfície pulpar desses discos e a superfície oclusal foi condicionada com ácido fosfórico por 15s. Sobre a dentina condicionada foi aplicado (n=9): água deionizada (controle), ACR 0,02%, 0,01%, 0,005%, glutaraldeído 5% (GD) ou peróxido de hidrogênio 3%. Após 60s, a superfície foi lavada e as câmaras foram incubadas por 24h. Foi avaliada a viabilidade das MDPC-23 (alamarBlue) aderidas na parede pulpar dos discos e os extratos foram aplicados em novas MDPC-23 e HDPCs (células da polpa dental humana) cultivadas em placas de cultura. Após 24h, essas células foram avaliadas quanto a viabilidade, atividade de fosfatase alcalina (ensaio da timolftaleína), presença de nódulos de mineralização (Alizarin red) e expressão gênica de ALPL, DSPP, MMP2, MMP9 e IL1B (PCRq). Vinte cinco molares adicionais foram seccionados para obter espécimes de dentina (n=50) que foram completamente desmineralizados com ácido fosfórico por 24h. Os espécimes de matriz dentinária foram tratados por 60s com: água, ACR 0,02%, 0,01%, 0,005% ou GD 5% e submetid... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Objective: To investigate the transdentinal cytotoxicity of acrolein (ACR) on pulp cells, as well as the ultimate tensile strength (UTS) of the dentin matrix, and the strength of resin-dentin bonds after dentin collagen biomodification with this cross-linker. Methods: Dentin disks (0.4 mm thick) were cut from sound human molars and adapted in artificial pulp chambers. MDPC-23 were seeded on the pulpal side of the disks and the occlusal surface was etched with phosphoric acid for 15s. The etched dentin was treated with (n=9): deionized water (control), 0.02%, 0.01%, 0.005% ACR, 5% glutaraldehyde (GD), or 3% hydrogen peroxide. After 60s, the surface was rinsed, and the chambers were incubated for 24h. The viability of MDPC-23 cells seeded on the disk was assessed (alamarBlue) and the extracts were applied on new MDPC-23 and HDPCs (human dental pulp cells) seeded in culture plates. After 24h, the viability of the cells was investigated as well as the activity of alkaline phosphatase, presence of mineralized nodules (Alizarin red) and ALPL, DSPP, MMP2, MMP9 and IL1b gene expression (qPCR). Additional twenty-five human molars were sectioned to obtain dentin specimens (n=50) which were completely demineralized in 10% phosphoric acid for 24h. The specimens were treated for 60s with: water, 0.02%, 0.01%, 0.005% ACR or 5% GD, and then submitted to a mechanical test to determine the UBS. Finally, flat dentin surfaces prepared in 40 human molars were etched with phosphoric acid and trea... (Complete abstract click electronic access below) / Mestre
23

Arken : Bostäder i stadens skärgård / Arken : Residences in the archipelago of the city

Andersson, Jennifer, Franke, Klara January 2019 (has links)
Ett stenkast från stadsdelen Liljeholmen i Stockholm ligger området Lövholmen. Ett idag till stor del övergivet industriområde där man möts av krossade rutor, förfallna byggnader och nedklottrade fasader. Stockholms stad har tillsammans med en rad olika byggherrar gjort en stadsplanering som är ett förslag om ändring i detaljplan, från ett industriområde till ett bostadsområde. Stadsplaneringen Strukturplan och ramverk för Lövholmen innehåller föreslagna riktlinjer om utformningen för en ny stadsdel. Syftet är att utforma ett gestaltningsförslag till en av fastigheterna enligt den nya detaljplanen som om den vunnit laga kraft, me även att undersöka hur planlösningar kan påverka människans hälsa och trivsel. Förslaget kommer förhålla sig till strukturplanens direktiv där målet är att göra Lövholmen till en tryggare och trevligare plats. Detta kommer göras med hjälp av analyser och undersökningar från allmänhetens önskemål och synpunkter. Resultatet, Arken, kommer visa ett bostadsförslag med en arkitektonisk anknytning till platsen som kommer göra Lövholmen till en mer harmonisk plats. Bostadsförslaget kommer medföra gemenskap för människor som bosätter sig i kvarteret samt genom genomarbetade planlösningar som grundar sig i undersökningar kring människans välmående. / A few steps away from the district of Liljeholmen in Stockholm lies the area of Lövholmen. A largely abandoned industrial zone where visitors are greeted by crushed window panes, dilapidated buildings and defaced facades. Stockholm City has along with a number of different developers made a proposal for a change in the detailed development plan, from an industrial area to a residential area. The urban planning Strukturplan och Ramverk för Lövholmen contains proposed guidelines for the design of a new neighborhood. Our purpose in this thesis is to design a residential proposal as if the detailed development plan has won legal force, also to examine how floor plans can affect human health and well-being. The proposal will relate to urban development guidelines by Stockholm stad, where the aim is to make Lövholmen a safer and nicer place. This will be done with the help of analyzes and surveys from the public's wishes and views. The result of our vision; Arken, will consist a housing proposal with an architectural connection to the place that will make Lövholmen a more harmonious site. The housing proposal will bring a sense of community to people who settle in the neighborhood as well as elaborated floor plans based on surveys on human well-being.
24

Studené asfaltové směsi s R-materiálem / Cold asphalt mixtures with R-material

Ševc, Jan January 2016 (has links)
The thesis is focused on the use of R-material into cold asphalt mixtures. It deals with cold recycling and with input materials for this technology. It verifies properties of R-material and residues of bituminous binder. It also verifies properties of designed cold asphalt mixtures by the probative controls (indirect tensile strenght and water resistance). Furthermore is focused on the experimental measurement of selected mixtures to ensure more characteristics. The amount of homogenity of R-material, quantity and quality of residues bituminous binder is essential for positive results.
25

Směsný recyklát do podloží vozovek pozemních komunikací / Waste building material to subgrade pavement

Masař, Daniel Unknown Date (has links)
The theoretical part of the diploma thesis searches the production of Construction and demolition waste and their subsequent transformation into the final recyclate and its possible use in roads. Attention is focused on the use of mixed recycled material into subgrade of the pavement and the characteristics of tests that must be performed before its used to the road. The next chapters pai attention to the problematic properties of recyclates, foreign experience with the use of mixed recyclate in Construction and the possibilities of its development. The practical part verifies the suitability of mixed recycled material into subgrade of the pavement using laboratory tests. The tests are performer on individual mixtures of mixed recycled material with cement, blast furnace slag or cement dust in various percentages. The results are then compared and it is evaluated which mixtures show the best properties. Part of the practical part is also the economic evaluation of these mixtures against commonly used materials.
26

Testning av betongskivor för inredningsändamål / Testing of concrete slabs for interior decoration puposes

Ashrafi, Karzan, Ali Ahmed, Ibrahim January 2021 (has links)
Detta examensarbete syftar till att utveckla ett nytt sätt att använda betong för inredningsändamål. Betong har alltid använts i större byggnader, infrastruktur och andra kategorier. Nyligen började den moderna inredningen använda betong inomhus, till exempel som bänkskiva eller som en hylla. Arbetet fokuserar på en huvudfråga: Är betong ett bra materialval för inredning? För att besvara denna fråga bestämdes några punkter för att komma till huvudfrågan. Följande punkter behövde testat och analyserad för att komma till svaren:    - Beräkna och testa betongens hållfasthet    - Testa slagtålighet    - Analysera hur betong reagerar med kemikalier med olika pH-värde    - Förhållandet mellan miljö och betong    - Studera produktionen av betong Laborationstest, litteraturskällor och fältstudier användes som metoder för att få ett resultat av ovan nämnda punkter. Resultaten visar att betong kan användas som inredningsändamål och kan användas i större utsträckning än vad som är fallet idag. Sammanfattningsvis är betong ett bra material som används för inredningsändamål och den framtida tekniken kommer att minska koldioxidutsläppen som följer med produktionen av betongen. Det kommer att göra betong ännu bättre som material att använda i framtiden. / The following thesis aims to develop a new way to use concrete as interior material. Concrete has always been used in larger scale buildings, infrastructure and in other categories. Recently the modern interior design started to use concrete indoors for example as countertop or as a shelf. This thesis focuses on one main question: is concrete a good material choice for interior use. To answer that question, we decided to have sub questions to help to get to the main question. The following questions needed test and analysis methods to get to the answers:    - Calculate and test the strength of concrete    - Test impact resistance    - Analyze how concrete reacts with chemicals with different PH-values    - Study the production of concrete    - Relation between environment and concrete Lab tests, literature sources, and field studies was used as methods to answer those questions. The results shows that concrete can be utilized as interior material and can be used to a greater extent than is the case today. In conclusion concrete is a good material as used for interior purposes and the future technology will decrease carbon dioxide emissions that comes with production of the concrete. That will make concrete even better as material to use in the future.

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