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72 Uppsatser om Singular value decomposition (SVD) - Sida 5 av 5

Bevattning av lagrat virke vid svensk skogsindustri : omfattning och miljökonsekvenser

Most of the saw and pulp industries have stored wood nearby their production, the main reason is to have a continuous wood flow to the production. Wet storage of wood is of great importance to keep the wood quality. Without water sprinkling the risk of drying outand decomposition through biological activity increases significantly and will result in a negative effect on future production and quality. One drawback of wet storage of wood is the leaching of chemical substances into the surrounding recipient. The log yard run-off contains phosphorus, nitrogen, phenols and organic substances. These substances can cause problems for the surrounding environment. The main objective of this project is to gain an understanding of the wet storage used by the Swedish wood industry and estimate the environmental consequences that run-off water will have on the recipient.

Varierad kaliumgödsling i potatis : en fältstudie i Hedemora

Variation in tuber quality within a single field was one of the motives for a pilot study in Halland, in south-western Sweden conducted during 2002. Quality problems in potatoes have been increasing due to the aggregation of several small fields with different land use history into larger farm units, which are heterogeneous in soil properties and fertility. The study in Halland indicated that both the uniformity and the mean size of tubers may increase from site-specific K fertilization, whereas total yields may be unaffected. The results from this pilot-study with site-specific fertilization showed that tubers reached a more uniform quality and gave a more uniform mean size, while the total yield wasn't affected at all. Site-specific K-fertilization has been applied for some years in Halland with good results. The aim of this study was to test this technique in another potato growing area.

Tickor på död ved

I dag råder det brist på död ved i Sveriges skogar. Detta på grund av det intensiva skogsbruket där man kalhugger och plockar bort all liggande ved. Dock är det viktigt med många döda träd i olika nedbrytningsstadier för många skogslevande arter. Svenska skogar har få urskogar där naturliga avdödningsprocesser av träd får ske och därför minskar den biologiska mångfalden i skogen. Tre arter som endast trivs i naturskog är tickorna ullticka, Phellinus ferrugineofuscus, gränsticka, Phellinus nigrolimitatus och vedticka, Phellinus viticola.

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.

Nästa år jag ska få G i svenska - en intervjustudie med andraspråkselever på gymnasiet

SammanfattningSyftet med studien var att undersöka tre andraspråkselevers situation på gymnasiet. De tre eleverna kommer från Afghanistan, och deras hemspråk dari är en dialekt av persiskan. En fråga var huruvida interferens från hemspråket kunde märkas i elevernas skriftliga och muntliga svenska. En andra fråga var på vilken nivå elevernas läs- och begreppsförståelse låg, och en tredje gällde vilka uppfattningar de hade om att lära sig svenska och att studera på gymnasiet. Slutligen söktes svar på hur lärare kan stödja eleverna i deras språkutveckling och därmed också i deras kunskapserövrande.Den metod som valdes var inspelning av intervjuer med eleverna för att få veta deras uppfattningar, samt kunna analysera uttal, syntax och form i talet och göra jämförelser med persiskan.

Kompostering av köksavfall och användning av kompost i köksträdgård i Chazuta, Peru : jordförbättring och/eller lösning på ett avfallsproblem?

All over the world the waste from human society is causing problems. In developing countries, large cities are polluted through huge amounts of wastes and people are forced to live very close to open deposits. Lima, capital of Peru, is no exception. The countryside in Peru has also a great challenge to face concerning the waste issue. Children and adults suffer from infectious diseases and contamination of the nature occurs as well. One solution to handle organic waste is to compost, which means a controlled decomposition of organic waste under aerobic conditions at certain temperatures.

Produktkoncept: lekhjälm i vintermiljö : ett nytt produktsortiment

A protection helmet for young people (3-7 years) in winter environment has been developed in this thesis. The result is a concept proposal for development at STIGA Sports AB in Eskilstuna. This thesis work has been performed during 20 weeks, for a Master of Science in Product and Process development at Mälardalen University Eskilstuna Sweden in September 2009 to January 2010. The helmet is shown as a CAD model with detailed solutions to the outer shell, interior and adjustability (in sizes 50-56 cm) which are the three focused areas in the development. Also a physical model in scale 1:1 has been developed and is shown in this thesis work.To achieve the best result possible the process started with an analysis of the market and the product.

Näringsretention i återskapad våtmark på betesmark : studier av en mad vid Bornsjön

It is important to construct or recreate different types of wetlands and study their retention of nutrients, since knowledge of their effectiveness in this matter is poor. In 2003 a wetland was constructed on an old meadow on the western shore of Lake Bornsjön in central Sweden. The main purpose of the wetland was to reduce the amount of phosphorus entering the lake, which is the back-up water supply for Stockholm when the city cannot obtain water from Lake Mälaren. Large areas around Lake Bornsjön consist of agricultural land and the nutrient concentrations in the inflows to the lake are usually relatively high (approx. 1 mg/l total nitrogen and 0.05-0.1 mg/l total phosphorus).

GIS och statistik vid dräneringsområdesvis kväveläckagebeskrivning i Halland

The last decades have shown increased nitrogen leeching from soil to water recipients. This is inSweden mainly due to over-manuring of agriculture land, effectivization of drainage systems and thedeclining extent of wetlands. The accumulated amount of nitrogen in water doesn?t only make itunsuitable for use by humans and cattle, but also decreases the biological diversity as well as negativelyaffect tourism and fish industry. In the most severe cases shallow maritime grounds can be completelydepleted of oxygen due to decomposition of the increased amount algae and plankton growth.This study have the aim to describe and quantify the nitrogen leeching from the Genevad drainagebasin, located in southern Halland, Sweden.

Variation i temperaturrespons (Q10) vid nedbrytning av biopolymerer

Nedbrytningshastigheten för organiskt material i marken kan komma att förändras vid varmare klimat. I dagsläget råder dock oenighet om hur nedbrytningen av organiskt material kommer att reagera på förändrade temperaturer; forskningsrapporter pekar åt olika håll. För att kunna förutsäga framtida scenarier är det viktigt att vi får kunskap om hur organiskt material kan komma att påverkas. Om koncentrationen av koldioxid i atmosfären ökar och den globala medeltemperaturen stiger kan nedbrytningshastigheten för organiskt material öka. Detta kan leda till en positiv feedback loop där mer koldioxid avgår från marken till atmosfären.

Geokemisk undersökning vid Rävlidmyrgruvan, Västerbottens län : provtagning, analys och förslag till åtgärder

The mining industry, in terms of ore excavation and metal production, is and has been important to the Swedish economy. In connection with the ore excavation process, large amounts of partly sulphidic waste are produced. When the metal sulphides are exposed to air and water they are eventually oxidised, which leads to the formation of acidic water with high concentrations of metal cations and sulphate ions, so called Acid Mine Drainage (AMD). This water may reach the nearest surroundings and cause negative environmental effects. By covering the waste with soil or water, the oxidation process can be minimised. At the Rävlidmyran mine in the county of Västerbotten open pit mining took place between 1951 and 1991.

Att restaurera forna tiders beståndsstruktur : ett exempel från Jämtgaveln

In Sweden today so-called "prescribed nature conservation burning" is performed due to the change in silvicultural law, certification and an increased knowledge regarding the field of fire in the forest landscape. The aim is to re-create structures and qualities made by the fire regimes of the past, though on a much smaller geographical scale. The structures and qualities to be re-created are for example broad leaf stands, trees with large diameter, heterogeneous stands regarding variables such as age and diameter. If we increase our knowledge of the constitution of forests characterized by fire, then we will be able to set goals for what achievements to reach both on landscape scale and stand scale. The aim of this paper is to try to describe how a stand from the past was composed regarding mainly the spatial arrangement and compare it with the stand of today in the same place. This to be done by using relict material, that is stumps and dead standing trees.

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