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121 Uppsatser om Oxygen - Sida 7 av 9
Elektrolytisk reduktion av zink vid reningsprocess
When cylinders for motor saws are manufactured there are high demands on the cylinders strength and wearing qualities. Aluminum is a material with low density and is used by Husqvarna AB for their motor saw cylinders. The aluminum is strengthening with nickel that is attached to the cylinders through electrolysis. When aluminum is in contact with Oxygen a film of oxide is formed. To eliminate the oxide and to prevent formation of new oxide zinc is used.
Vattenkvalitet och risker vid ändrat intag för vattenförsörjning i Västerås
Water is the most essential resource for life. In cases where drinking water is processed from surface water it is important to ensure the raw water is of good quality, and is suitable for processing through the water treatment plant.The drinking water for Västerås is sourced from Västeråsfjärden, in the western side of Lake Mälaren. The city itself is home to marinas, ports, a wastewater treatment plant, the Svartån outlet, sewage pumping stations and stormwater outlets. Because of the negative effects these activities have on surface water quality, Mälarenergi AB is interested in relocating the raw water intake point to Granfjärden, 10 km east of Västeråsfjärden. At Granfjärden the intake point would be less exposed to the activities in Västerås, and could be placed at a greater depth, resulting in better water quality.In this Master?s thesis the water quality and the pollution risks at Västeråsfjärden and Granfjärden sites are compared.
Fysisk träning som hjärtrehabilitering efter en myokardieinfarkt: en litteraturstudie
Background: Myocardial infarction is the most common individual disease among people in the west world. In Sweden there are over 50 000 women and men who get myocardial infarction every year and about 40 % of them dies. Exercise training is one part of cardiac rehabilitation and since 1980 Sweden use the guidelines from that time. Aim: The aim was to review exercise-training modalities in cardiac rehabilitation after myocardial infarction and the physiologic- and psychological effects. Method: Facts were obtained by searching through the database PubMed for articles published from 1994 and ten years forward.
Syntes av hydroxyapatit/ nanocellulosa kompositer
Cellulose nanocrystals (CNC) are great candidates for composite materials. The reasons why CNCs are such attractive materials for them are due to their great mechanical properties, high aspect ratio and low density. On the other hand, hydroxyapatite (HAp) is a kind of calcium phosphate and a main component of bones and teeth. The purpose of the present study is to make oriented nano-sized composites with CNC and HAp. Although some researchers carried out to make CNC composites with HAp for biomedical materials, nano-sized and oriented ones haven?t been achieved yet.
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.
Energieffektivisering i ett reningsverk för skogsindustriellt avloppsvatten genom förfällning av extraktivämnen
Pulp- and papermills expend vast amounts of water in order to produce pulp, paper and cardboard. Hence, they alsocreate vast amounts of waste water which has to be cleaned before it can be released into the receiving body of water. Insuch a wastewater treatment plant, tremendous amounts of energy are expended by the aeration in the biologicalcleaning process. This aeration is necessary to supply the microorganisms that shall decompose organic material withOxygen, which they need for their metabolism. The transfer of Oxygen from the gas phase to the liquid phase isprimarily inhibited by surface-active substances in the waste water like resin acids or fatty acids.
Effekten på nedbrytningen av rötter vid tillförsel av ammonium sulfat i en granskog i sydvästra Sverige
Decomposition of organic matter is a critical process in the ecosystem, which involves many essential biotic and physical parts. Decomposition is therefore an important process both above and below ground. The rate of decomposition is dependent of many environmental factors for example: pH, moisture and supply of Oxygen. The decomposition can therefore be affected by large scaled environmental influences, such as acidification and climatic changes. The root litter in the forest is in different ways affected by acidification, liming and manuering.
Utvärdering av avloppsvattenreningen vid Hallsta Pappersbruk : Kartläggning av inkommande avloppsvatten och optimering av driftparametrar
Hallsta paper mill uses large amounts of water during the pulp and paper making processes. The wastewater is treated in two separate activated sludge processes referred to as BIO 1 and BIO 2. The main aim is to reduce the organic substance content, measured as COD (Chemical Oxygen Demand) before the wastewater is released into the environment. Since the effluent produced is very rich in organic substances, the addition of nitrogen (N) and phosphorus (P) are necessary to give satisfactory treatment results. Problems with sludge bulking sometimes occur which lead to increased levels of suspended matter and nutrients in the effluent.
Elevers fysiska aktivitetsnivå under skoldagen på Bygg- och anläggningsprogrammet i gymnasieskolan
Syfte och frågeställningarSyftet med den här studien var att undersöka den aeroba fysiska aktivitetsnivån hos gymnasieungdomar på Bygg- och anläggningsprogrammet under skoldagar som innehöll teorilektioner, praktiska lektioner, idrottslektioner och raster. Frågan som ställdes var: Hur ser den fysiska aktivitetsnivån ut under teorilektioner, praktiska lektioner och lektioner i idrott och hälsa samt under raster hos gymnasieelever på Bygg- och anläggningsprogrammet.MetodI studien deltog 9 pojkar i åldern 16 år, längd 174-192cm och vikt 51-91kg. Den test som genomförts är 5 Minuters Pyramid Test (5MPT) och registrering av aerob fysisk belastning gjordes med hjärtfrekvensmätningar. 5MPT är ett skytteltest som är fem minuter långt, där försökspersonen tar sig fram och tillbaka mellan två stolpar och så snabbt som möjligt passerarfram och tillbaka över en vertikal pyramidformad trappramp (sträcka 5,5 meter). Antalet vändor, skattad ansträngning samt hjärtfrekvens (HF) registrerades.
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).
Förändring av olika fysiologiska parametrar vid styrketräning hos äldre
SammanfattningSyfte och frågeställningar. Syftet med denna studie var att på äldre personer studera olika fysiologiska parametrar före och efter en period på åtta veckor med styrketräning som utförs tre gånger i veckan. Frågeställningarna var: Hur påverkas statisk och dynamisk maximal styrka i främre lårmuskulaturen av styrketräning? Är det någon skillnad i resultat mellan koncentrisk och excentrisk styrka i lårmuskulaturen före och efter styrketräningsperioden? Är det någon skillnad i förändring mellan benstyrka uppmätt med isokinetisk teknik jämfört med uthållighetsstyrka och ett kort funktionellt benstyrketest? Hur påverkas maximal syreupptagningsförmåga registrerad via submaximalt cykeltest respektive vid pyramidtestet av träningsperioden?Metod. I studien deltog 20 generellt ej påtagligt aktiva män och kvinnor i åldrarna 66-79 år.
A porcine type 1 Diabetes Mellitus model, for non-invasive in vivo imaging of the glucagon-like peptide-1 receptor in the pancreas, using [68Ga]Ga-DO3A-VS-Cys40-conjugated synthetic exendin-4 in PET-CT
Diabetes mellitus is a rising epidemic throughout the world and there is currently great interest in quantifying the beta-cell mass (BCM) in vivo non-invasively. In the present experiment, the feasibility of in vivo imaging of the glucagon-like peptide-1 receptor (GLP-1R) in beta-cells was examined, using the positron emission tomography (PET) tracer [68Ga]Ga-DO3A-VS-Cys40-exendin-4 as a marker, in native pancreatic beta-cells of a porcine diabetic animal model and healthy controls.
Eight Swedish high-health domestic pigs were randomly assigned to be either controls or made diabetic using streptozotocin (STZ). The experiment proceeded during eight weeks, starting with an acclimatisation period. Once the pigs had been socialised they underwent surgery for the insertion of a jugular vein catheter, allowing induction of diabetes with STZ, intravenous (i.v.) injections and stress-free blood sampling. Development of diabetes was confirmed by clinical examinations, blood glucose values and insulin-staining of pancreatic sections post mortem.
The diabetic pigs were insulin treated and responded well.
Modellering av organiskt material i avloppsvatten vid mekanisk tillverkning av pappersmassa : Regressionsanalys baserad på COD- och TOC-analyser vid olika grader av blekning och raffinering
I avloppsreningen på Hallsta pappersbruk i Hallstavik reduceras dagligen tonvis med organiskt material innan avloppsvattnet släpps ut i den intilliggande Edeboviken. Bruket är ett så kallat integrerat pappersbruk vilket innebär att man tillverkar både pappersmassan och pappret på plats. Det är främst vid framställningen av massa som det organiska materialet löses ut ur veden och hamnar i processvattnet som så småningom når brukets avloppsreningsverk. På bruket tillverkas papper i olika ljusheter, vilket kräver olika stora insatser i form av blekkemikalier så som väteperoxid och hydrosulfit (även känt som ditionit). Blekningen varierar över tid i produktionscykler och det är sedan tidigare känt att en ökad blekning av massan löser ut mer organiska föreningar.
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.
Dokumentation av ensilering med fokus på clostridiesporer i mjölk :
To produce milk of good standard the feed for the animals kept for milk production is an important part in the work of quality. This makes it important to feed them with good forage, especially when feeding with silage. The process of making silage is very complex and requires a careful handling to be successful. The fundamental idea is to create an anaerobic environment in the herbage to favour the desirable micro-organisms, in this case the lactic acid bacteria. This environment is created by careful handlings were the importance is to pack the crop well and cover it as soon as possible to exclude Oxygen.