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894 Uppsatser om Mechanical properties - Sida 46 av 60
Undersökningsmetodik för klorerade lösningsmedel i marken
Chlorinated solvent are volatile organic substances that can be harmful for humans and for the environment. Examples of common chlorinated solvents are perchloroethene, PCE, and trichloroethene, TCE. Chlorinated solvents appear as contaminants in soils primarily where they have been used as washing fluids in dry-cleaning facilities or as degreasers in metal industries. Chlorinated solvents are DNAPLs (dense non-aqueous phase liquids), which means that they are not easily dissolved in water and that they sink to the bottom of the aquifer. Adsorption to soils is low so chlorinated solvents are mobile in soils.
Mekanisk integration av en IR-detektor i en Stirlingkylare
The master thesis ?Mechanical Integration of an IR-detector in a Micro Cooler? has beenperformed at FLIR Systems AB in Danderyd. FLIR Systems is a world leader in the design,manufacture and marketing of thermal imaging camera systems.The thesis project is divided into to two areas, Production Method and Noise.The Production Method concerns the positioning of a detector on the cold finger within the IRcamera.The detector has to be positiond with very high accuracy at the center of the cold finger,so it can be placed in line with the optical axis to avoid movement of the picture during zooming.The positioning of the detector is at present done with the help of specially designed guides on aplate on top of the cold finger. The design workes well but the special machining needed for thisplate is very expensive.The goal concerning the production method was to derive a new more cost effective method forthe assembling and positioning of the detector on the cold finger by replacing the guides on theplate with a reusable equipment or some other alignement operation.Several concept ideas have been generated with the help of concept generation methods in theform of concept classification trees and concept combinational tables. Two of these conceptswere selected to be further refined.
Syntes och egenskapskarakterisering av volframoxid framställd med magnetronsputtring
The system tungsten-oxygen has potential of being suitable for decorative coatings since ceramic coatings are often hard and wear resistant, and since modulations in oxygen content or incorporation of small ions could give bright colours. The aim of this report was to investigate the relationship between process parameters and the properties of the films, with the wear resistance being of special interest.Samples with tungsten to oxygen ratios in the range of 100:0 to 25:75 at% were made using reactive sputter deposition, either with constant gas flow, or gas flow controlled by optical emission of the plasma. The hysteresis of the system, which means that a certain gas flow will cause different pressure and/or target voltage depending on in what way the flow is reached, makes it interesting to control the process where the system makes the steep change from metallic tungsten to ceramic tungsten oxide. This is difficult and thus requires precise control equipment.The samples were analysed using X-ray diffraction, X-ray photoelectron spectroscopy and an empirical wear test suitable for small components like cell phone cover for example, in order to characterize the structure, composition and wear resistance of the coatings. The results could be divided into three groups: (I) tungsten-like, with very low oxygen content; (II) mixed phase and (III) tungsten oxide like, with oxygen content close to 75 at%.
Vegetationsutveckling och brandhistorik i Tyresta under 9000 år : en pollenanalytisk studie av en skvattramtallmyr i Tyresta nationalpark, Södermanland
Analyses of pollen and charcoal in peat cores, together with age-structure data of Pinus sylvestris from a Ledum-Pinus-mire in the Tyresta National Park (south-east Sweden) show the regional vegetation succession and fire history over the last 9000 years. Five major stages of mire development are identified: 1. Lake (c 7000-6400 cal BC); 2. Wet fen (c 6400-6000 cal BC); 3. Deciduous fen (c 6000 cal BC to c cal AD 700); 4.
Hundar kring benen. En analys av belastning och storleksvariation hos hundarna i det mesolitiska Skåne
This paper deals with variations in the osteological material of dog (Canis familiaris L.) from the Mesolithic Scania, southern Sweden. The general aim is to discuss the use and specialisation of dog during the period, and differences or relations between cultures and traditions within the Mesolithic period. The study is based on a analysis of the bone material from the sites; Ageröd I:A-D, Ageröd I:H-C, Bredasten, Bökeberg III, Hög, Löddesborg, Ringsjöholm, Segebro, Sjöholmen, Skateholm I-II and Tågerup, phase 1-3, with datings from Late Maglemose Culture to Early Ertebølle Culture. The seminar paper also includes descriptive statistics of the osteometrical data of Denmark, from several studies of Degerbøhl (1927) and Noe-Nygaard (1995, 2003). The study is focused on the relation between size, robusticity, muscle grooves and ligaments of mandibula, tibia, radius, humerus, femur and metacarpalia/metatarsalia.
Efterfrågan av grova sågade dimensioner och hyvlade produkter bland Wallnäs AB:s kunder : en marknadsundersökning
The purpose of this thesis is to study whether there is a demand for sawn wood products of large dimensions and planed goods among Wallnäs AB:s customers. The thesis consist of two main parts, one survey among Wallnäs present customers and another one which purpose is to increase Wallnäs customer base. Finally there is a chapter that describes what properties the raw material has to have in order to produce the demanded products.
The survey to the present customers was conducted through a questioner. A sample of those who stated an interest for either sawn wood products of large dimensions or planed goods, were later contacted for a telephone interview.
To reach out to new customers, relevant companies has been identified through the Swedish Trade Councils data base and through the member list of the Timber Trade Federation.
Ljudlandskap i kulturmiljöer
This bachelor thesis aims to draw attention to sound in the heritage sector in Sweden. In particular, to thesoundscapes that can be identified in our cultural heritage environments. Sounds in an environment, here calledsoundscapes, affect our perception of the environment and how we remember it.To find out how the heritage sector uses and would be able to use sounds, I have firstly studied if audio recording iscomparable with the visual photographic image. I then present examples of sound documentation concerning theconservation of built environment. In addition, I have interviewed five key informants who all have a centralresponsibility for five cultural heritage environments.
Jämförelse Mellan Lätt och Tung Stomme på ett Kontorshus
I början av varje nytt projekt stöter man på de olika alternativ av stomme- och bjälklagskonstruktioner som finns att välja mellan, och frågan blir ofta vilken alternativ som är optimal för den aktuella projekteten.Den optimala lösningen för varje projekt existerar inte, på grund av de olika faktorer och förutsättningar som styr projektet, till exempel: ekonomi, typ av byggnad, terrängtyp etc.Frågeställningen i denna rapport är om limträ eller betong är den mest optimala alternativen som stommaterial i det aktuella projektet.Jämförelsearbetet utgående från förutsättningar har gjorts genom att dimensionera delar av ett projekt med både materialen. Fokus har lagts på skillnader i byggnadshöjd, vindstabilitet och grundläggningen. Resultaten tyder på om man ska bygga ett kontorshus eller flervåningshus vore betong mer lämpligare alternativ jämfört med limträ.Skillnaden i byggnadshöjd finns men är förvånansvärt inte så stor mellan de två olika stommaterial. Dock skillnaden varierar avsevärd när det gäller bjälklagshöjd mellan limträ och betong. Detta pga krav på nedböjning och svikt som ställs på limträbjälklag.Båda stommaterial klara vindstabiliteten utan plintar, som är ganska intressant speciellt med tanke på limträets låga vikt.När det gäller grundläggningen, blev skillnaden betydlig större mellan limträ och betong.Dimensionering enligt Eurokoder har gjorts genom egna handberäkningar och även användandet av programvaran Strusoft..
Att fånga flödet i kollektivtrafiken : En jämförelse mellan handelsplatser i Hong Kongs och Stockholms tunnelbana
The retail sector is in a continuous development. What demand looks like and where the consumers want to shop has changed during the last years. Market place, demand, supply, external factors and politics affect how the retail sector develops. To make a market place attractive a variety of factors have to be considered.In Hong Kong a model called Rail & Property is used, this means that the development of the subway is integrated with the development of the city. The model is both successful and economically sustainable.Today the supply of shops and services in Stockholm´s subway stations is rather small.
Verkligt värde : Hur tillämpas verkligt värde på förvaltningsfastigheter i förvaltningsbolags koncernredovisning?
Datum: 2010-06-03Kurs: Kandidatuppsats i företagsekonomi, 15 hp (FÖA300)Lärosäte: Mälardalens högskola, VästeråsInstitution: Akademin för hållbar samhälls- och teknikutvecklingTitel: Verkligt värde -Hur tillämpas verkligt värde på förvaltningsfastigheter i förvaltningsbolags koncernredovisning?Författare: Belma Bjelevac, Ida Emet, Hana KaramehmedovicHandledare: Riitta LehtisaloExaminator: Cecilia LindhProblemformulering: Vilka värderingsmetoder finns för fastställandet av verkligt värde och vilken är den vanligast förekommande samt mest lämpliga metoden idag hos de undersökta fastighetsbolagen?Hur förhåller sig de undersökta bolagen till begreppen försiktighetsprincipen och rättvisande bild vid värdering av deras förvaltningsfastigheter till verkligt värde?Syfte: Syftet med studien är att genom en empirisk undersökning få en ökad insikt om hur de undersökta fastighetsbolagen i sin koncernredovisning fastställer och redovisar det verkliga värdet på sina förvaltningsfastigheter.Metod: Uppsatsen bygger på en kvalitativ undersökning genomförd med hjälp av mejlintervjuer med tre fastighetsbolag samt studerande av deras årsredovisningar.Slutsats: De undersökta bolagen tillämpar en avkastningsbaserad metod, vilken kan ses som mest lämplig i den rådande ekonomiska situationen. Verkligt värde speglar en mer rättvisande bild än vid värdering till anskaffningsvärde, dock tas inte hänsyn till försiktighetsprincipen i lika stor utsträckning. Nyckelord: Försiktighetsprincipen, förvaltningsfastighet, IAS 40, rättvisande bild, verkligt värde.
Smart plombering och märkning
The background for this degree thesis is a need to replace the existing seal used to protect equipment containing secret or sensitive equipment used by Swedish Defence. The target design should satisfy both the need for tamper evidence and reduce Life Cycle Cost. In developing a new design for a seal, additional benefits such as improved logistics support and indication of attack methods such as heat and solvents have been considered.The lack of guiding principles for end users of seals became evident during the interviews. Major concerns for the future are education of users, information about actions if a seal is broken and user liability.The design work was divided into several phases. A feasibility study was performed including investigation of theory of labels, materials and possible technologies.
Att nyttja marken 30 meter från järnvägen : hur platser, syften och miljö vävs samman
The purpose of this work is to raise ideas and interest for land that is very much forgotten,unused and neglected in terms of maintenance and usability. Railroads are often seen as adirty and loud intrusion in the landscape and therefore cities turn their backs on them. Theland around railroads is not considered useful despite its often central location and scrublandis common in these areas.The starting point of this work is the restrictions and possibilities linked to the land withinthe security distance 30 meters from the railroad center. Within this security distance thereare numerous limitations and regulations due to the nature of railroad use. These limitationsare counted for in the initial chapter and lay the foundation for the rest of the work.
Utveckling av en fiberberikad probiotisk fruktdryck
The purpose of this study was to investigate whether resistant maltodextrin is suitable as a fiber source in the probiotic fruit drink ProViva Mango without affecting the probiotic bacterium Lactobacillus plantarum 299v, viscosity or the sensory experience of the drink. Resistant maltodextrin is produced from hydrolyzed corn starch and is classified as a soluble dietary fiber. It is relatively resistant to digestion in the small intestine, where approximately 10% can be broken down, 50% can be fermented in the colon by the intestinal flora and 40 % is excreted in the faeces. Resistant maltodextrin has several important qualities when it comes to food processing. When added in a product, it does not affect the viscosity or taste and it is heat and acid stable.
Ageism: A literature review
Background: The studies analyzed have shown among other things that ageism appears to be an overlooked category in intersectionality studies, elderly is offered care in worse conditions than non-elderly and stereotypes restrict elderlys social space to act. The gray tsunami is approaching but studies show that large gaps separate different agegroups.
Aims: The study discuss how scientists reason about ageism towards elderly in a social science discussion.
Method: A literature review was conducted in which fifteen articles were analyzed. The database used, is the librariescatalog Summon, at Malmö University. The articles was compiled in themes to give dilated clarity in ageisms complexity towards elderly. The results are being discussed on the basis of terror management theory, gerotranscendence and social identitity theory.
Results: Elderlys relation to society's expectations about aging can affect a self/body-dualism, a split.
Analys av lageregenskaper utifrån mätningar i testrigg
Vertical hydropower units has a rotating mass of up to 1000 tons. For the generator and turbine to work well the rotating system is required to be centered in relation to the surrounding structure. This is achieved by means of radial bearings. The dynamic characteristics of these bearings have a strong impact on the overall rotational dynamics of the total system and thus influence the vibrations in the unit. At Vattenfall Research & Development in Älvkarleby ongoing research is taking place on how the bearing parameters should be represented in the rotor dynamic calculations.