Sökresultat:
1114 Uppsatser om Composite materials - Sida 1 av 75
Ett kandidatexamensarbete inom lättviktskonstruktioner .
Due to recent legal enactments regarding carbon dioxide emissions, the car industry is facing higher demands. An effective way of reducing these emissions is to minimize the weight of the vehicle. This thesis constitutes a feasibility study on whether or not it is applicable for the car industry to utilize an inner floor structure comprising Composite materials. The principal was the projectSåNätt, in which the main participant was Volvo Cars Corp. In consultation with a reference group, consisting of delegates from the industry and KTH, a specification of requirements was produced.
Kartläggning av energiförluster : gällande klimatskal och ventilation för Stora Enso Timbers Pelletsfabrik i Grums
Due to recent legal enactments regarding carbon dioxide emissions, the car industry is facing higher demands. An effective way of reducing these emissions is to minimize the weight of the vehicle. This thesis constitutes a feasibility study on whether or not it is applicable for the car industry to utilize an inner floor structure comprising Composite materials. The principal was the projectSåNätt, in which the main participant was Volvo Cars Corp. In consultation with a reference group, consisting of delegates from the industry and KTH, a specification of requirements was produced.
Konsolidering av v?vsp?nda papperstapeter: analys och metodutveckling
Printed and painted wallpaper on a weaved fabric backing was a common way to decorate homes in Sweden during the eighteenth and nineteenth centuries. Not much is written about the craftsmanship in relation to the hanging of these wallpapers and even less about the conservation of the objects. Even so, many wall segments remain in situ and in museums and are more often than not in dire need of conservation such as deacidification and consolidation. These are composite objects, consisting of cellulose materials with different properties along with adhesives and paints. Analysis of the materials is required to ensure safe handling and choice of conservation materials, and to establish a treatment plan which will be executed in several steps.
This thesis aims to identify these steps and develop a method for conserving the wall segments with suitable materials, preferably without altering the source material to any significant degree.
Förskollärare och barnskötare : yrkesroller i förändring
Syfte: Syftet med denna studie var att se hur och varför volatiliteten påverkades i DJIA, S&P 500 och NASDAQ Composite under IT-bubblan.Metod: Års- och månadsvolatiliteten för DJIA, S&P 500 och NASDAQ Composite har beräknats under 1995-2004 med hjälp av data från Yahoo Finance.Empiri: Resultatet visar att volatiliteten var väsentligt högre i NASDAQ Composite än vad den var i S&P 500 och DJIA som i sin tur höll en liknande volatilitet i förhållande till varandra.Analys: I analysen framträdde det att volatiliteten blev väsentligt högre i samband med att bubblan sprack under maj 2000 fram till dess att paniken lade sig kort efter maj 2002. Det fanns en hög överensstämmelse mellan denna rapport och övriga tidigare studier. Teorierna var mestadels väl applicerbara.Slutsats: Volatiliteten för DJIA, S&P 500 och NASDAQ Composite var som högst mellan 2000 och 2002 under undersökningsperioden 1995-2004. IT-bubblan uppstod samt sprack till följd av irrationellt investeringsbeteende bland investerarna på aktiemarknaden och paniken som uppstod efteråt gjorde att volatiliteten på aktiemarknaden höll sig förhållandevis hög fram tills den lade sig kort efter maj 2002. NASDAQ Composite hade högst volatilitet till följd av IT-bubblan medan DJIA och S&P 500 hade likvärdig volatilitet.
IT-bubblans inverkan på den amerikanska aktiemarknadens volatilitet
Syfte: Syftet med denna studie var att se hur och varför volatiliteten påverkades i DJIA, S&P 500 och NASDAQ Composite under IT-bubblan.Metod: Års- och månadsvolatiliteten för DJIA, S&P 500 och NASDAQ Composite har beräknats under 1995-2004 med hjälp av data från Yahoo Finance.Empiri: Resultatet visar att volatiliteten var väsentligt högre i NASDAQ Composite än vad den var i S&P 500 och DJIA som i sin tur höll en liknande volatilitet i förhållande till varandra.Analys: I analysen framträdde det att volatiliteten blev väsentligt högre i samband med att bubblan sprack under maj 2000 fram till dess att paniken lade sig kort efter maj 2002. Det fanns en hög överensstämmelse mellan denna rapport och övriga tidigare studier. Teorierna var mestadels väl applicerbara.Slutsats: Volatiliteten för DJIA, S&P 500 och NASDAQ Composite var som högst mellan 2000 och 2002 under undersökningsperioden 1995-2004. IT-bubblan uppstod samt sprack till följd av irrationellt investeringsbeteende bland investerarna på aktiemarknaden och paniken som uppstod efteråt gjorde att volatiliteten på aktiemarknaden höll sig förhållandevis hög fram tills den lade sig kort efter maj 2002. NASDAQ Composite hade högst volatilitet till följd av IT-bubblan medan DJIA och S&P 500 hade likvärdig volatilitet.
Celltal som mått på mjölkens kvalitet med avseende på mjölkens sammansättning
Mastitis, an inflammation of the udder mainly caused by a bacterial infection, induces an increase in the somatic cell count (SCC) in milk and is consequently one of several factors affecting SCC in milk. In this literature review it is investigated whether SCC; on udder quarter, cow composite or bulk tank milk level, can be used as a quality marker with focus on milk composition in terms of the content of fat, lactose, total protein, casein and whey protein. According to this literature review the relation between SCC and milk composition is not reliable either on udder quarter, cow composite or bulk tank milk level. SCC was related to lactose, casein and whey protein on udder quarter level; lactose and whey protein on cow composite level and lactose on bulk tank milk level.
Konceptarbete om skidbalk i kompositutförande till BVS10
This thesis has been performed at BAE Systems Hägglunds, which is located in Örnsköldsvik. Hägglunds has a wide background of engineering, where they have manufactured all from airplanes to lifting cranes. Currently they only produce track vehicles at Hägglunds, where they manufacture the CV90 and BVS10 models. This thesis concerns the BVS10 which is an all-terrain-vehicle. The main purpose with the BVS10 is to enable transportation of material and personnel thru tough terrain.
Syntes av hydroxyapatit/ nanocellulosa kompositer
Cellulose nanocrystals (CNC) are great candidates for Composite materials. The reasons why CNCs are such attractive materials for them are due to their great mechanical properties, high aspect ratio and low density. On the other hand, hydroxyapatite (HAp) is a kind of calcium phosphate and a main component of bones and teeth. The purpose of the present study is to make oriented nano-sized composites with CNC and HAp. Although some researchers carried out to make CNC composites with HAp for biomedical materials, nano-sized and oriented ones haven?t been achieved yet.
Konstruktion av efterbehandlare
The purpose of this report is to examine various roof structures that can operate in a warehouse with large spans. The building that is examined in the report is currently under construction, and the roof construction has already been selected. The selected roof system will therefore be compared with some other structures and materials that have been possible. The report will evaluate three different frame materials, two insulating barriers and two overlaying materials. Another important part in major construction projects is the roof safety.
Ny kölkonstruktion på segelbåtar
This Master Thesis is a product development project that has been carried out in cooperation withSvea Teknik AB. The company has developed an apparatus for attachment of a keel to a hull base ofa boat. The purpose for this thesis has been to compare a new concept of keel attachment incomposite material to thetraditionaldesign solution. This new keel attachment minimizes thedamages that may arise on the keel and the hull of the boat in shape of stresses impacts at grounding.Today it is a problem, relating to keel attachment on sailing boats having a fin keel or a bulbous keel.The manufacture focus on developing larger draught and shorter keel blades. The overall purpose isto increase performance of the sailing boat.The task for this thesis was to develop a concept of keel blade in composite material and investigateattachment to a sheet-shaped element.
Jämförelsestudier av Takkonstruktioner med Stora Spännvidder
The purpose of this report is to examine various roof structures that can operate in a warehouse with large spans. The building that is examined in the report is currently under construction, and the roof construction has already been selected. The selected roof system will therefore be compared with some other structures and materials that have been possible. The report will evaluate three different frame materials, two insulating barriers and two overlaying materials. Another important part in major construction projects is the roof safety.
FE-modellering av hjullast på sandwichpanel
This bachelor thesis in mechanical engineering was performed during the spring2015 in collaboration with Composite Consulting Group in Laholm. TheComposites Consulting Group works mainly with design and details of differentcomposite projects, their main area is FE-calculations, 3D-modelling andmechanical tests with Composite materials.The aim of this bachelor thesis was to simplify the calculation process of solidmechanics for sandwich panels by simulation with computer software. The goalwas to decrease the time for the design and calculation process of the constructionand the cost of the practical tests. Our task was to build a static three dimensionalmodel with the computer software Abaqus, where the result should correspondwith the practical pressure tests in laboratory.The project started with collection of material data from Composites ConsultingGroup and by learning the software Abaqus, simultaneously a specification wasdeveloped in corporation with the company. Later on, a static wheel pressuremodel in the software Abaqus was produced which simulated the behavior of thesandwich panel during static wheel-pressure by a pallet truck.
Kan en periodiseringsbaserad investeringsstrategi effektiviseras med hjälp av fundamental analys?
This paper investigates whether the traditional accrual based trading strategy first documented by Sloan (1996) can be refined using fundamental analysis. Specifically, this is done by implementing the composite signal F_SCORE introduced by Piotroski (2000) to identify financially strong or weak firms. We find that by applying both investment models simultaneously, in a model we call P_KOMB, the mean market-adjusted return earned by an investor exploiting the accrual anomaly can be increased by 14.8% annually. This is achieved by taking a long position in strong firms (as defined by the composite signal) in the lowest accrual portfolio, while an offsetting short position is taken in weak firms in the highest accrual portfolio, repeated annually between 1997 and 2007. Consistent with prior studies, positive market-adjusted returns can be attained through assessment of accruals as well as key value drivers found in historical financial data.
Bildernas byggstenar : En studie om pixlar och vektorers egenskaper i form av digitala material
With a new digital world that runs parallel with our physical one, we are also facing a new type of architecture and new materials that this new architecture is built on. In this thesis I examine pixels and vectors, two of the digital materials used to create pictures. By approaching them as digital materials, I have mapped their different qualities, when and where one or the other is more or less applicable and the reason behind it. My main research question asked was the following: Are the (digital) materials challenged outside their primary fields of application, and in that case, in which way? With this question in mind, I carried out a semiotic picture analysis on four pictures, later on dividing them into four different categories, based on their different qualities and their ability to deliver information.
Landet lagom och dess "lagomläromedel" : Om jämställdhet och genus i grundskolans läroplaner och läromedel från olika årtionden
The purpose of this study is to examine two educational materials from different decades, to see if they have a conscious gender and equality perspective, and to see if they have followed the development society made regarding gender and equality. Even the curricula have a part in my study as I will relate them to the educational materials. Equality as a concept means briefly that women and men should have the same conditions, and gender depicts our notions of femininity and masculinity.I have chosen to do textual analyses, focusing on multimodal discourse because I analyze both text and image. I also use both quantitative and qualitative methods.My questions are: In which way do the curricula and the educational materials express equality?; In which way do the curricula and the educational materials express gender?; Do the educational materials express the fundamental values written about equality and gender in the curricula? And, if this is the case, does it mean that educational materials have followed the development of the Swedish society?The conclusion of this work is that equality and gender are presented as goals in both curricula, but the new curricula have developed that section more.