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11262 Uppsatser om Composite material - Sida 1 av 751

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.

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.

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.

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.

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.

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.

Asymptotiska egenskaper hos vissa kombinatoriska strukturer

In an attempt to develop a more cost-efficient material for solar   energy applications, nano-particles of nickel oxide composite in a silikatmatris manufactured with solar gelmethod and studied structurally by electron microscopy. Furthermore, the thin film optical properties characterized by Variable. Angel Spectroscopic Ellipsometry. Sol gelfilms suitability as a selective absorber surface is also analyzed by optical modeling..

Grupperingar i en nysammansatt klass

The purpose of this paper is to try to get an understanding of the underlying causes and reasons that students starting in seventh grade junior high school seek out a particular group, and the extent to which they do so.The work is based on the questions: How do students perceive the meeting with their prospective bench-companion in a new composite class? What should a teacher consider when it comes to bench placement in a new composite class? Do the students change, and if so to what extent, friends when they start high school? What are the factors that affect/have affected the students' choice of friends? How large a role does the school play for pupils relationships? What thoughts and feelings do the students have regarding new encounters?I have conducted in-depth interviews with six adolescents in grade seven as the basis for the understanding of how students relate to group selection and group affiliation, and I have then compared this material with previous research on the subject. Furthermore I have availed myself of literature in social- and group psychology.The conclusion which has emerged is that the most important component of a group-process is the sense of solidarity and security, and the results show that students largely retain their old relationships rather than adding new, when they start high school. Hence the teacher plays an important role in ensuring that any imbalance in the group is offset and make sure that nobody is excluded, but also to help make room for new groups and be aware of the sensitive and responsive phase of life that the young people are in..

Vikingatida eller medeltida kammar i Västergarn? : en fallstudie av enkelkammarna funna vid Högskolan på Gotlands seminariegrävningar i Västergarn mellan åren 2006-2011

The University of Gotland has between the years 2006-2011 conducted seminar excavations in Västergarn parish, Gotland. During this time 167 comb fragments have been registered. Out of these are 51 of importance for this study, since they are defined as either a single-sided composite comb or a comb case. The purpose of this thesis is to enlighten the earliest period in the history of Västergarn by focusing on the earliest forms of combs and their cases. And as the title expresses do the combs date to the Viking Age or the Middle Ages? The combs from the excavations will be compared to different type schemes, both Viking Age and Middle Age and different places in Scandinavia such as Lund, Oslo, Lödöse and Gotland.

En studie av metodbyte vid sintring av hårdmetaller till mikrovågsintring samt dess ekonomiska fördelar : Självständigt arbete i teknisk fysik med materialvetenskap & Självständigt arbete i kemiteknik

The aim with this study was to investigate the effects a change of manufacturing process would have on the mechanical properties of drill bits made of a WC/Co composite used for stone cutting. The method used today is sintering, where the material is heated in a conventional sintering oven. The other method was microwave sintering, where the material is heated by radiation in the microwave region. Also an investigation of the manufacturing cost were made.The main difference between the two heating methods is that the conventional way is a rather slow process and the microwave method is very fast. The material is also heated homogeniously in the method with mirowaves, aposed to the case with the conventional sintering where the material is heated from the outside in.This makes the material harder and more wear resistent.

Optisk karakterisering av tunna SiO2/NiO-filmer syntetiserade med en sol-gelmetod

In an attempt to develop a more cost-efficient material for solar   energy applications, nano-particles of nickel oxide composite in a silikatmatris manufactured with solar gelmethod and studied structurally by electron microscopy. Furthermore, the thin film optical properties characterized by Variable. Angel Spectroscopic Ellipsometry. Sol gelfilms suitability as a selective absorber surface is also analyzed by optical modeling..

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.

Viktoptimering av ett kompositchassi till en multimodal lättviktsfarkost

This report describes the master thesis project ?Weight Optimization of a Composite Chassis for a Multimodal Lightweight Vehicle? which is a part of the Master program in Naval Architecture and a part of a research project at the Centre for Naval Architecture, KTH. Demands on smart and energy efficient transport solutions are continuously increasing. In the Stockholm region the citizens are expected to increase with 25% and the road vehicles with 80% until 2030, putting high demands on the traffic system. Using a small multimodal vehicle deals with this problem and uses both the land and waterways for transportation.

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