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2063 Uppsatser om Pore size distribution - Sida 1 av 138

Inverkan av olika joner och jonconcentrationer på porstorleksfördelningen i trämassa-fibrer

The basic ingredient of paper is the individual wood fibers. The property of the fibers depends on a variety of factors e.g., method of pulp production and processing. The final sheet quality depends in part on how the fibers interface between each other and therefore factors that affect the fiber size are of interest.The flexibility of the fibers depends in part on the pore water i.e., the fiber swelling. The sheet becomes less flexible at low water content which gives a loss in strength. Thus it becomes desirable to increase the water uptake.The experimental investigation described in this report consists of exposing the wood fibers to different ions and ionic strength and then measure the pore size by thermoporosimetry where a DSC (Differential Scanning Calorimeter) is used.

Hassel (Corylus avellana) som indikator på markanvändningshistorik

Hazel (Corylus avellana L.) is a common feature of meadows and pastures where it can grow in large populations and become very old. Is it possible to use the size of hazel stools for age determination and is it possible to use the size distribution of a population to provide information about how the land has been used? Hazel populations on ground where the lake-water level had been lowered, has been studied to validate an already developed growth model of hazel clones. Different hazel populations, on wooded meadows affected by mowing or grazing or overgrown meadows, were studied to evaluate the method utilizing hazel as land use indicator. The growth model was used to compare the size distributions of hazel populations with historical periods, which has been important for changes in agriculture or demography.

Effect of plant maturity at harvest of haylage on digestibility and faecal particle size in horses fed forage-dominated diets

Time of harvest affects nutritional value and digestibility of haylage since plants are in different developmental stages. The aim of this study was to examine the effect of plant maturity of haylage cut in June, July and August on digestibility and faecal particle size in horses.Forage and faecal samples used for the analysis of apparent dry matter digestibility (DMd) and particle size distribution in faeces were from a feed-study performed in the autumn of 2009. Twelve horses were used in the study, divided into three groups in a change-over experiment. Each group was fed haylage harvested in June, July or August during three periods. Faecal grab samples were taken from each horse and pooled so that one sample represented one horse during one period.

Distributionsekonomisk optimering av dagligvaruhandelns lokalisering : förstudie till ett forskningsprojekt

The structure and performance of grocery distribution in Sweden has changed profoundly since the second world war. Increasing access and usage of the private car, in combination with an accommodating town planning has enhanced the exploitation of scale economies within distribution firms. There is, however, some ambiguity concerning the overall efficiency of the distribution system when the costs associated with travelling and purchasing performed by households are treated as an integrated part of the total distribution cost function. The purpose of this master thesis is to develop the foundation of a spatial optimisation model, which defines the most efficient distribution system. The underlying idea is that the optimal localisation and size of grocery stores is a function of economies of scale within the firms weighed against distributions costs within the households, such as transportation costs.

Skogsbränslets fraktionsfördelning

This study has analyzed particel size distribution and needle content in chipped logging residuals (branches and tops) delivered to the district heating plant Ryaverket in city of Borås, Sweden. Two fuel assortments has been analyzed: Chipped logging residuals from pure softwood and from mixed fuel (connifers and broadleaves). The samples has been sieved at Linneaus University laboratory.The study of particle sizes indicates that only 53,2 % of delivered fuel is within the fuels specification (7? 45 mm). The needle content is in this study 12,4 % (dry mass) which is higher than expected..

Förbränning av pellets framställda av defibrerad granråvara :

Fuel pellets are in Sweden mainly produced from sawdust and cutter shavings. Before the pelletising process the raw material is dried to attain consistent moisture content and ground up in a hammer mill. In the densification process (pelletising) the ground material is forced through holes in a rotating die. This heats up the wood particles which cause them to soften and self bond. After the process the pellets are cooled, sieved and bagged. The milling process creates a wide range of particle sizes.

Uttorkning av lera : Orsaker och följder

When building a house or similar the stress on the ground increases and deformations can arise. The deformations create a foundation that the building is not constructed for and damages on the building arise. The increased stress on the ground can be derived back to the building, but it is possible that the increased stress may well derive from different sources such as other buildings or trees.       The building is an older property, built in the late 19th century alternatively early 20th century, and is today used for rental housing and has suffered severe damages due to subsidence. The goal of the thesis is to find possible causes for these subsidences. The thesis was executed as a combination between literature- and casestudie. After careful studies it has been found that a probable cause for these subsidences is trees. Through field- and lab studies it has been found that the trees has effected the ground through there accumulation of water.

Bestämning av optimal fordonspark -Distribution av bitumen vid Nynäs AB

Nynas produces bitumen at two refineries in Sweden. The bitumen is shipped to seven depots along the swedish coast line, and from the depots special trucks handle the transportation to customers. Recently Nynas has transformed its supply chain and closed down a few depots. At the moment the company is considering a further reduction of the number of depots. In connection to these discussions an analyse of the companys distributionsystem and of possible changes is required.

ANALYS AV FLERBOSTADSHUS : Med inriktning på ytfördelningen över tiden

Currently, there are no clear statistics on how the floor plan and room size in apartment buildings has changed over time since the postwar period. The statistics available is average area per apartment which can be found on Statistics Sweden's website. This report has the aim to increase knowledge about how the Swedish home have changed over time.The questions that the report will answer are:For apartment buildings, how has the living area been distributed since the postwar period?Why has the area distribution changed over time?A survey of the houses built during 1950-2014 was made before questions could be answered. A case study was also made which a total of 90 apartments were analyzed and divided into three eras, the people´s home, the million programme and the neomodernism.

Stjälkröksvamp (Tulostoma brumale) : stora eller små individer?

The spatial population structure of the saprotrophic basidiomycete Tulostoma brumale was investigated at a site in south eastern Sweden. Sporocarps were mapped and collected, and somatic incompatibility tests between mycelial cultures cultivated from the sporocarps were used to identify genets. Calculations of the size and numbers of genets and their distribution were performed. The spatial distribution of the tested sporocarps and the identified genets are presented graphically in a grid. The total number of identified genets within the investigated area (1210 m2) was 27 based on 48 tested sporocarps.

Latitudinal patterns in body size of Roesel?s bush cricketMetrioptera roeselii within and outside the continuous area of its distribution

Over time, species colonize new areas naturally or through humans. The colonizers areoften few and founded populations represent only a fraction of the genetic diversityexisting in the original population. If the established population becomes isolated afterthe colonization event genetic diversity will remain low and if the population, in addition,remains small in size for an extended period this will lead to increased inbreeding andpossibly inbreeding depression. Metrioptera roeselii is a common species with awidespread distribution in continental Europe. During the last century, it has expanded tothe Scandinavian Peninsula which is separated from continental Europe by the Baltic Sea.My aim was to test the hypothesis that individuals in isolated populations in Scandinaviaincluding Denmark and the Baltic Sea islands are smaller than individuals in thecontinuous part of its distribution due to low genetic diversity and lacking incoming geneflow.

Kartläggning av spånprodukter vid Sävar såg

A change towards using more biofuels than fossil fuels is taking place in Sweden, and in many other parts of the world. This makes the use of fuel pellets increasingly popular, causing a greater demand for sawmill sawdust products. There is a trend towards the use of multiple types of shredders, instead of a single type in each sawmill. The purpose of the study was to characterize the different flows of saw particles that can be found at Sävar såg when cutting thick or thin wood with different cutting techniques. The saw particles size, shape, moisture content and heat value were analysed by the cutting stations: first cutting fast and slow, second cutting fast and slow, grading fast and slow and planning.

Hur livshistoriekaraktärer hos Europeisk abborre (Perca fluviatilis L.) påverkas av cykliska förändringar i populationsstrukturen

This report deals with life-history variation for Eurasian perch (Perca fluviatilis L.), with special emphasis on age and size at maturity in females, in perch populations that have changed in size distribution. The collection of fish samples was made with multimesh gill nets year 2011. The perch?s length, height, weight, status of gonads has been analyzed, and by observing the opercular bone the age has been determined. In two lakes close to Umeå in northern Sweden, Fisksjön and Ängersjön, the live-history traits of perch have been studied.

How streaming media can be used in commercial mass
distribution

Mass distribution with techniques as multicast and peer-to-peer are becoming increasingly important in the Internet. Today the distribution of sound and video over Internet, so called streaming media, is static due to the unicast method. This results in a linear increase of distribution costs and therefore no conditions for commercial scalability. This thesis describes why multicast may be the only scalable alternative for commercial mass distribution of streaming media over Internet. Mass distribution through peer-to-peer technology promises a lot but is fronting a couple of great challenges, for example asymmetric bandwidth, locality and legalization.

Genetisk studie av inavel och fertilitet hos hund :

Inbreeding, the mating of related individuals, has been the one dominating breeding strategy for dog breeders during the last 200 years. However, its negative effects on fer-tility and other fitness traits, a phenomenon called inbreeding depression, have been ignored in the quest of perfect unity in conformation or performance. The purpose of this study was to test the hypotheses that litter size is reduced as a consequence of in-breeding, affected by both the inbreeding coefficient of the dam and the litter and that a rapid increase in the inbreeding coefficient affects litter size more than a slower rate. Data were collected from the Swedish Kennel Club registry of origin. Breeds included in the study were the Bernese Mountain Dog, the Cocker Spaniel, the Golden Retriever, the Rottweiler and the West Highland White Terrier.

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