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608 Uppsatser om Properties - Sida 35 av 41
Frystorkning Kontrollerad torkning av kulturhistorisk dräkt?
Cultural objects may become wet by deliberate water cleaning, water disaster or watersoaked for other reasons. Air drying textile objects and even other organic materials from awater wet state, involves many problems depending on the strong capillarity action of water.Damages and changes such as bleeding of dyes, stains or lines of impurities from watermovement, shrinking or stiffness can occur. Freeze-drying as an alternative drying methodhas often been used for wet archaeological and marine objects, but more seldom for historicalmaterials.This bachelor thesis addresses the issue of whether freeze-drying can be an alternative controlleddrying method for historic costumes. Costumes and related objects are often compositeobjects, consisting of multiple materials, as well as being three dimensional, all of whichwill complicate drying. The purpose of this study was to investigate whether it is possible tohandle costume objects after wet cleaning for drying by freeze-drying, and if damages due tosurface tension of water, can be avoided in this way.
Carbon sequestration in the pastoral area of Chepareria, western Kenya : a comparison between open-grazing, fenced pastures and maize cultivations
Carbon sequestration through restoration of degraded pastoral soils is an advocated way of mitigating global warming, and simultaneously alleviating poverty. An often proposed rehabilitation strategy is fencing of pastures, a method that was introduced to the farmers of Chepareria by the Vi-Agroforestry organization in 1987. The landscape of Chepareria changed from eroded, over-grazed grasslands, to a mixture of open-grazed commons, pastoral enclosures and cultivations. The aim of this study was to investigate (1) if the soil organic carbon (SOC) is higher inside the enclosures than on the open-grazed commons, (2) if SOC is affected by duration of fencing and (3) what effect cultivation of pastures has on the SOC. Estimations of vegetation cover and deep profile (100cm) soil sampling was performed on six clusters containing; (1) open-grazing (OG) (2) 1-5 years of fencing (FENCED(1)), (3) 7-10 years of fencing (FENCED(2)), (4) 15-23 years of fencing (FENCED(3)), (5) maize from OG (A(OG)), (6) maize from fenced pasture (A(FENCED)).
Fire impact in the wood quality and a fertilization experiment in Eucalyptus plantations in Guangxi, southern China
Chinas government has a multifunctional program for a more sustainable forestry since 2000. This six key forest programs goal is to develop a more sustainable forest sector but also take environment consideration. The state forest administration in China has decided to create 5.8 million hectare of fast growing and high yield forest. Eucalyptus has showed to have good Properties for pulp and timber production and therefore Eucalyptus plantations are under development in costal areas in southern China. By adding extra nutrients, growth can be enhanced in Eucalyptus plantations.
Vätedriven förbränningsmotor : Klarläggande av framtida hållbarhet
Today when new and harder demands on CO2 emissions are developed, vehicle manufacturers must work to develop new engine solutions to new kinds of fuels to replace fossil fuels. A fuel that could be applied is hydrogen. When hydrogen is combusted only water vapor occurs. Hydrogen is known to be explosive and flammable. These Properties are both good and bad for combustion.
Förpackning med förbättrad miljö- och säljaspekt : Ett projekt i samarbete med Primus Sverige AB
This work of examination describes an environmentally oriented product development aimed to develop new packaging with improved environmental and sale aspects of the products from Primus Sweden AB. The report covers the design process from the first collection of facts to the final results with a description of all methods involved in the work. The focus has been on a clear environmental awareness and the report contains a deepening of the concept life cycle assessment (LCA) for product development. In the process, the consumers? opinions of the brand Primus and environmental profiling formed the basis for the packaging to communicate the right values such as quality, technology, environmental awareness and adventurer?s first choice.The deepening of the life cycle analysis shows that composting and other alternative treatment of the biological cycle is not possible to implement in a satisfactory way in the design process.The work results in two final concepts.
Transporttidsmodellering vid provpumpning i heterogen jord : spårämnesförsök i en isälvsavlagring
When protection zones for wells are delineated, it is important to acquire good knowledge about possible travel time from different points in the catchment area to the well. Often, simple analytical methods are used for estimating travel times and the assumption is made that the hydraulic conductivity is relatively homogenous within the aquifer. Nevertheless, many aquifers are strongly heterogeneous which may lead to differences between estimates and actual travel times. As a part of the process to develop improved methods for delineating protection zones for groundwater supply wells, a tracer experiment was performed in a glaciofluvial esker formation in Järlåsa. On the basis of the experiment, a numerical flow model was created for the test site.The purpose of this master?s thesis was to apply the flow model to an aquifer where the hydraulic conductivity shows great variability and should be described by a stochastic distribution.
Simulation driven design : An iterative approach for mechanical engineerswith focus on mesh, quality and convergence
This thesis of 15 hp has been implemented at Halmstad University, incollaboration with Saab Dynamics in Linköping. Saab Dynamics is a companyoperating in the defence industry where competition is tough. This necessitatesnew ways to increase efficiency in the company, which is the basis for this thesis.Saab Dynamics wants to introduce simulation driven design. Since SaabDynamics engineers have little experience of simulation, required a usermethodology with clear guidelines. Due to lack of time, they chose to assign thetask to students, which resulted in this thesis.The aim of the thesis is to develop a methodology in mechanical design, wherethe designer uses the FE analysis early in the design process to develop thestructures' mechanical Properties.
Framtidens begravningsplatser : en historisk tillbakablick, dagssituationen och visioner för framtidens gestaltningsuttryck
The purpose of this article is partly to find out how
the burial grounds are used today and the needs of its
visitors, but also to develop the character and
expression of future burial grounds. My suggestions
focus on burial grounds without religious attributes;
something that, according to the burial law
(Begravningslagen, 1990:1144), the manager of the
burial ground is ordered to obey. In my design I aim to
fulfill any requests regarding the place of burial that
have been raised during my study.
I have chosen the history of burial grounds as my
starting point and will subsequently discuss their
significance in today's society. I describe what
distinguishes the burial ground throughout history
from medieval times and onwards. Tradition and
religion are closely linked regarding burial rituals.
Rehabilitation in a tropical secondary rain forest in Malaysian Borneo : early effects of canopy properties on light conditions at the forest floor
Tropisk regnskog i Sydostasien är ett av de områden som hyser störst biodiversitet i världen, av vilken stora ytor är hotat. Ön Borneo drabbades av en katastrof åren 1982-1983 efter att väderfenomenet El Niño orsakat torka med vidsträckta skogsbränder som följd. Detta lämnade stora ytor av Borneos skogar i ett undermåligt, sekundärt tillstånd. På grund av detta startades INIKEA projektet med syfte att rehabilitera skogar i regionen kring Tawau vid östkusten av delstaten Sabah i Malaysia. I denna studie undersökte jag resultatet av rehabiliteringsarbetet på krontaket i tre olika skogstyper genom att ta hemisfäriska foton med en digital systemkamera (DSLR).
Materialegenskaper och dimensioneringsmetodik för vattenledningar : En sammanställning av de material som förekommer i Norrvattens ledningsnät samt dimensioneringsverktyg för plastledningar
Detta examensarbete har genomförts med anledning av att Norrvatten har önskemål om att få en rapport om de material som används i deras vattenledningsnät med fokus på typiska skador kopplade till ett specifikt material eller tillverkningsmetod. Det har framkommit indikationer om att kunskapen om rörmaterial och dess egenskaper med tiden har försämrats då den äldre generationens projektörer efterlämnat en kunskapslucka efter sig.Syftet med rapporten är att ge en god överblick av materialen i Norrvattens ledningsnät. Det krävs kunskap om materialen för att analysera sambandet mellan läckningsstatistik och materialets egenskaper.Informationshalten varierar mellan de olika materialen. Detta beror framförallt på materialets uppbyggnad och svårighetshalten att redovisa en klar och rättvis bild över dem. Materialen och dess information är uppdelade i kapitel för att underlätta för läsaren att på ett enkelt sätt förstå sammanhangen.Ett annat viktigt kapitel i denna rapport är beskrivningen över de anläggningsmetoder som valdes att tas med, dels markförlagda ledningar men också två schaktfria metoder vilka är infodring och rörspräckning.
Utveckling av processparametrar inom en hårdmetallindustri
This report analyzes and examines a hypothesis for finding a method to optimize thelength of the delubrication process time based on a total charge weight. The work hasfocused on the holding time for delubrication and the total charge weight.An important step in the manufacturing chain of cutting tools is when the greenbodies undergo the sintering process. Today, the delubrication step has the sameprocess time independent of the total charge weight. An implementation of a methodto adjust the delubrication process time would give more consistent quality of thecutting tool´s internal characteristics but also reduce the time course of the sinteringprocess. In the present project two methods for this goal were tested, thedevelopment of an algorithm and a weight interval subdivision with associateddelubrication process times.During delubrication a pressure increase is observed due to the decomposition of thePEG in the powder mixture.
Värdering av förvaltningsfastigheter : Hur påverkar verkligt värde företagens intressenter?
År 2005 infördes standarden IAS 40 som ger svenska börsnoterade förvaltningsfastighetsbolag möjligheten att redovisa sina fastigheter till verkligt värde. Verkligt värde har kritiserats på grund av det bygger på subjektiva bedömningar och det kan leda till en missvisande redovisning som kan få negativa konsekvenser för intressenter. 1 januari 2013 infördes den nya standarden IFRS 13 för att ställa ytterligare upplysningskrav gällande värdering av tillgångar till verkligt värde. Denna studie behandlar hur värdering till verkligt värde påverkar intressenters informationsbehov, deras uppfattning av fastighetsvärdering till verkligt värde och resonemang kring införandet av IFRS 13.Syftet med undersökningen var att förklara för hur olika intressenters behov av redovisningsinformation påverkas vid värdering av förvaltningsfastigheter till verkligt värde. För att uppnå studiens syfte har en kvalitativ metod använts där djupgående intervjuer genomförts.
Specificering av produktionstransformatorer : Rekommenderade avsteg från IEC 60076 för att vid upphandling beskriva en robust enhet
As break downs of production transformers are costly and often result in long outages it is essential for reliability of operation that the transformers are manufactured to be robust. The aim of this M.Sc. thesis is to investigate if deviations should be made from the standard IEC 60076 ? Power Transformers in order to describe a robust large power transformer for procurement.The investigation has been conducted in three stages. In the first stage a definition of the term robust was developed in consultation with the client Vattenfall Vattenkraft.
Komfortsanalys med hänsyn till vibrationer orsakade av människoaktiviteter. : Ett modernt dimensioneringsproblem för huskonstruktörer
Comfort analyses regarding human induced vibrationsIt is not too common among civil engineers in Sweden to perform comfort analyses considering the vibrations caused by human activities. In addition, the Swedish standards lack requirements to be used for comfort analyses in design of floor-systems. The demand for large spans in combination with slender slabs, is today a reason to investigate the floor-system constructions, in order to prevent disturbing vibrations and oscillations.The purpose of this thesis is to create a guide for how a comfort analysis, considering vibrations, should be implemented. Göran Svedenbjörk who is an expert in structural dynamics has been interviewed where he presents his latest project Värtaterminalen and answers some questions about vibrations due to human activities.Floor-systems, consisting of concrete slabs supported by steel or concrete beams, have been investigated with simulations in the finite element program Abaqus. In the simulations, the influence of various factors on the natural frequency of floor-systems and the acceleration level caused by dynamic loads, is studied.
"en labyrint av vägar" : en kvantitativ och språkfilosofisk studie av taggar och taggstruktur i Stockholms stadsbiblioteks folksonomi
The purpose of this study is to perform both a quantitative and language philosophical analysis of the folksono-my and the tags in the Stockholm public library catalogue, which together with the Umeå university folksonomy, and the folksonomy of the Norrköping public library are the only library folksonomies in Sweden.The purpose of the first part of the study is to perform an analysis of the linguistical structure of the tags in the folksonomy. To do this a quantitative analysis has been conducted to grammatically categorize and evaluate tags using a method based on Louise Spiteri?s article ?The structure and form of folksonomy tags: the road to the public library catalogue? and the SAO guidelines. This part of the analysis aims to answer questions like: what characteristics do the tags in the folksonomy have and in what ways do they separate themselves from subject headings in a controlled vocabulary? Tags were here categorized according to grammatical Properties like parts of speech and their social and private characteristics.