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447 Uppsatser om Bone mineral density - Sida 25 av 30

Simulering av valkar i pappersrullar : och analys av de slappa stråk som uppkommer

Då en pappersrulle har partier där pappret är längre kallas det ibland för slappa stråk. Det finns flera orsaker till slappa stråk och en av dessa orsaker är att pappret har en ojämn tjockleksprofil. I dessa fall uppstår de slappa stråken eftersom den ojämna tjockleksprofilen gör att pappersrullen på de positioner där pappret är tjockare får en större diameter än i övrigt. Då papper rullas över dessa åsar eller valkar som har en större diameter töjs pappret ut och då det rullas av rullen är det slappt. Körbarhetsproblem till följd av att pappret är slappt i vissa partier är ett stort problem inom pappersindustrin.

Kemisk stabilisering av gruvavfall från Ljusnarsbergsfältet med mesakalk och avloppsslam

Mine waste from Ljusnarsbergsfältet in Kopparberg, Sweden, is considered to constitute a great risk for human health and the surrounding environment. Some of the waste rock consists of sulphide minerals. When sulphide minerals come into contact with dissolved oxygen and precipitation, oxidation may occur resulting in acid mine drainage (AMD) and the release of heavy metals. The purpose of this study has been to characterise the waste material and try to chemically stabilize the waste rock with a mixture of sewage sludge and calcium carbonate. The drawback of using organic matter is the risk that dissolved organic matter can act as a complexing agent for heavy metals and in this way increase their mobility.

Lokaliseringens betydelse vid deponering av avfall på stort djup: Ett exempel med slutförvar för kvicksilverhaltigt avfall

Av de många olika ämnen som används i vårt samhälle kan vissa klassas som miljöskadliga och farliga. Metallen kvicksilver är ett av de allra farligaste gifterna i vår miljö. Beslut har fattats att all användning av kvicksilver ska avvecklas och det kvicksilver som finns i omlopp behöver bortskaffas på bästa sätt så att risker för miljö och människors hälsa minimeras. Det säkraste alternativet för ett slutförvar av kvicksilver anses vara en djupt bergdeponi. Möjligheten finns då att använda sig av befintliga anläggningar såsom till exempel en gruva, som påtalas av Naturvårdsverket i deras rapport ?Slutförvar av kvicksilver?.

Ekonomi vid uttag av långa toppar som skogsbränsle i slutavverkning :

The market for biofuels from the forests have had a positive development and the job initiators for this master´s thesis wanted to examine the profitability of a method for harvesting forest fuel, which was unfamiliar to them. The method was the ?long tree tops-method?, here called the LT-method. The LT-method is characterised by the fact that timber is harvested as the only roundwood assortment while the rest of the stem, which in other cases would become pulpwood, is harvested as forest fuel together with the logging residues. The method is based on the assumption that advantages in handling of the forest fuel assortment such as increased load weights for forest hauling and truck transportation, should compensate for the lower price for pulpwood when sold as forest fuel. The aim of the study was to compare the profitability of the LT-method with the GROT-method (harvest of timber, pulpwood and logging residues) and conventional logging without any harvest of forest fuel, and aslo to try to identify factors affecting the profitability of the different methods.

Femtio Nyanser av Co-branding - En kvantitativ studie om effekterna av co-branding på konsumenters varumärkes- och produktutvärdering beroende av kvalitetssegment och hedoniska shoppingmotivationer

The retailing industry has an extremely high density of brands. In order to differentiate its offer, both retailers and suppliers, are constantly forced to come up with new ways to launch their products. A collaborative strategy between two brands is called co-branding, which means that both the private label and the supplier's brand are displayed on the new product packaging. Several studies have shown that a co-branding strategy is successful, but many operators are still reluctant to use co-branding in fear of long-term losses due to potentially damaged business relations. The objective of this study is to explain how the product- and brand related value for customers, retailers and suppliers is affected by co-branding between private labels and national brands.

Förändring av radiocesiumtillståndet i jordbruksgrödor i Gävleborgs, Västmanlands och Uppsala län efter Tjernobylolyckan samt en fallstudie med stallbalansberäkningar på en mjölkgård :

Several radioactive nuclides were deposited in Sweden after the Chernobyl accident in 1986. The greatest attention was given to 137Cs because of its relative long physical half life of about 30 years. 137Cs will be present in nature for more than 100 years before it has vanished completely. When radiocaesium decays to a stable end product ionizing radiation is emitted, which can cause cancer in humans that has been exposed to a high radiation dose. Radiocaesium behaves like potassium and is easily taken up into biological systems.

Jämförelsestudie av tilläggsisolering

Rapporten behandlar och utvärderar tre olika isolermaterial, Polyisocyanurat (PIR), grafitcellplast och mineralull, vid tilläggsisolering av miljonprogrammets byggnationer.  Stora delar av miljonprogrammet är nu i behov av upprustning. Samhällets skärpta krav gällande energiförbrukning gör att nya rationella metoder och material krävs för att tillgodose ställda krav. Att tilläggsisolera är en del i denna upprustning, och eftersom valet av isolermaterial ofta faller på gamla beprövade metoder och materialval, såsom mineralull, syftar denna rapport till att öka kunskapen om alternativa, mer högpresterande isolermaterial.Isolermaterialens egenskaper tas först upp och behandlas i en generell jämförelse där ekonomiska och tekniska aspekter beaktas.För att konkretisera och påvisa utfallet i ett specifikt fall genomförs en studie för ett referensprojekt, kvarteret Hundlokan, som ägs och förvaltas av Fastighets AB Förvaltaren. I studien undersöks tre olika alternativ för vart och ett av materialen vid tilläggsisolering utvändigt av Hundlokans fasader. Samtliga alternativ ställs sedan mot varandra och utvärderas med hjälp av: fukt-, U-värdes-, energi-, kostnads- och LCC-beräkningar (livscykelkostnad).Enklare fuktberäkningar som påvisar relativ fuktighet (RF), ånghalt och temperatur i väggens olika skikt genomförs.

Produktivitet vid selektiv mekaniserad bioenergiröjning av eftersatta röjningsbestånd :

In Sweden, harvesting pre-commercial thinning (PCT) stems for energy purposes is a interesting way of financing the high cost of preparing dense stands for a profitable first conventional thinning. This concept can be labelled bioenergy thinning. The aim of this study was to quantify the productivity of a Vimek 404R light harvester with an accumulating Naarva-Grip cutting head during the bioenergy thinning of a self-regenerated stand west of Sunnansjö in Dalarna. The stand was birch-dominated, contained 15 371 stems/ha, and measured on average 4,6 cm Dbh and 7 m tall. Even though the driver was well experienced with the machine, the stand in question was the first one that he ever thinned in this manner. Nevertheless, the driver strived to accumulate as many stems as possible during each crane cycle and chose to cut taller stems in half so as to make the handling and forwarding of the harvested stems easier.

Klövform och klövsjukdomar hos intensivt uppfödda köttrastjurar :

The top selection of Swedish beef bulls are evaluated yearly by Svensk Köttrasprövning AB at Gismestad. The bulls are selected from six different breeds; Angus, Blonde d´Aquitaine, Charolais, Hereford, Limousin and Simmental, and are kept on straw bedding apart from a concrete alley in front of the feeding area during the six months of evaluation period. The bulls are evaluated according to their fertility scores, growth, exterior and temperament and the exterior, body posture and claw conformation reflect important qualities for their longevity. In spite of good values for fertility, it has been noticed in the last years that the fertility results and longevity have been unsatisfactory and claw and/or bone disorders have been suspected as a contributory cause. Persson et al. (2007) studied breeding bulls from Gismestad and other places, which had been slaughtered due to poor fertility (no pregnancies in the herd during their last year in service).

Structure and tree diversity of lowland limestone forest on Seram Island, Indonesia

There have previously been very few studies of forests on Seram Island in the Eastern Indonesian archipelago and none before on lowland limestone primary forests. The COLUPSIA project on collaborative land use planning has therefore chosen Seram as one of two project sites. The objective of the COLUPSIA project is to establish collaborative and equitable land use planning. In order to achieve its objective the COLUPSIA project aims to improve understanding of traditional resource management and how it interacts with governmental systems, as well as enhancing knowledge about tropical landscapes and ecosystem services.The aim of this study was to contribute to the COLUPSIA project through describing lowland limestone forest on Seram Island in respect to (1) forest structure, (2) tree species richness and (3) tree species composition. We set up 5 plots, each of 0.2 ha, at one site, Mawalai, and collected data on tree variables (tree diameter ?10 cm) as well as for some other life forms and environmental data.

Fertilization in Eucalyptus urophylla plantations in Guangxi, southern China

StoraEnso decided in year 2002 to build a pulp mill in the province of Guangxi, southernChina, and also establish eucalyptus plantations to provide it with raw material. By 2010StoraEnso controls about 90 000 of planned 120 000 ha, out of 75 000 ha is already plantedwith Eucalyptus.By using better genetic material, improve the tending, selecting the sites more careful and byusing a proper fertilization regime StoraEnso hopes to increase the mean annual incrementfrom today?s 25 m3/ha, on bark, to 35 m3/ha. This study is one part in this work to increase themean annual increment in the plantation.This master thesis is the forth in a series, that has followed up a fertilization trial that startedin spring 2006 when the trial was laid out and treatments decided. The aim with the trial is toexamine the production potential of Eucalyptus urophylla in Guangxi, southern China.

Gestaltning av stadens utemiljöer - Naturlikt kontra formellt & abstrakt :

In the increasing urban environments and the modern societies demands for sustainability there is a challange in planning cities with a balance between density and a satisfying access of recreational environments. For attractive cities these environments need to be designed to fit every inhabitants? demands and opinions in some way. Increased knowledge and understanding is therefore needed about how different design styles in landscape architecture affect people and the cities. In this bachelor thesis benefits and disadvantages as well as the experience and impact of two fundamental design styles i discussed; naturalistic and formal/abstract design.

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.

Uppföljning och analys av råmaterialmarknaden: Volvo Aero
Trollhättan

Flygmotorindustrin är en ledande industri i att utveckla och nyttja avancerade legeringar. Titanlegeringar har använts inom flygbranschen sedan 40-talet, men i andra branscher har de varit mindre vanliga. I dag ökar titananvändningen inom flera olika branscher samtidigt som flygbranschen är i en kraftig högkonjunktur. Efterfrågan är stor på nya flygplan och motorer för att minska vikt och bränsleförbrukning. Den ökade efterfrågan har bidragit till att priset på titanmetall har flerdubblats under en tvåårsperiod.

Utfackningsvägg av lättbetongblock i passivhus

AbstractThis report intends through a case study to investigate if lightweight concrete isappropriate as main material in the outer wall of a seven storey residential building.A technical design is carried out in accordance with the definitions and requirementsfor passive houses, given by FEBY?s1 ?Demand specification for passive houses?.A literature review is also carried out for a comparison between regular bolt wall andlight weight concrete wall, with a focus on the safety of moisture.The lightweight concrete block used in the report is as a celblock produced by thecompany H+H Sweden AB.The methods used have resulted in compliance with requirements andrecommendations from authorities. Calculations of energy, noise and moisture riskassessment has been carried out.The work has resulted in the conclusion that the lightweight concrete itself is notable to isolate in the extent necessary to obtain chosen U-value of 0,1 W/m2 ° C,without getting to thick. Therefore additional insulation is needed. There are fewrelevant reference objects built with only light weight concrete.

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