Periods of hypoxia are a recurring issue in Brunnsviken. Main factors that trigger hypoxia in Brunnsviken are eutrophication  due to anthropogenic emission of nutrients, stratification in the water column due to salinity and temperature differences  that prevents mixing and a sill inlet that prevents water exchange. As an attempt to improve the oxygen levels, bottom water is pumped from Brunnsviken causing aerated surface water to flow back into the basin.  The objective of this Master?s thesis was to study the change in dissolved oxygen levels due to pumping.

In a multi-year project at Swerea Swecast AB studies on influence of dissolved gas on inclusions have been made. The knowledge about these parameters could be used to increase the quality of the final steel casting. The purpose of this thesis was to closer examine the impact of the oxygen level on inclusions.The questions asked were:? What was the amount of inclusions at different levels of oxygen?? What was the size of these inclusions at different levels of oxygen?? What does the inclusions consist of at different levels of oxygen?This was studied by measuring and sampling, sample preparation and microscopic analysis using an optical microscope and a scanning electron microscope (SEM). Measurements and sampling was performed at Smålands Stålgjuteri AB in Eksjö and at Swerea Swecast AB in Jönköping.

Kväve är ett element med både positiva och negativa effekter på ett kolståls egenskaper och det är därför av yttersta vikt att under tillverkningsprocessen kontrollera kvävehalten i stålet med hänsyn till kravet på slutproduktens egenskaper. Möjligheten att styra stålets slutliga kvävehalt påverkas i hög grad av förloppet i LD-processen, d.v.s. det processteg där högkolhaltigt råjärn konverteras till lågkolhaltigt råstål, i huvudsak genom tillförsel av ren syrgas. Både kol och syre har en stark inverkan på kvävets löslighet i flytande stål. Ett flertal planerade försök med provtagning under pågående LD-process och analys med LECO® har legat till grund för en kartläggning av kväveförloppet, särskilt med avseende på konvertering av stål som återanvänds i processen, s.k.

The aim of this thesis was to examine if it is possible to keep nitrogen in the form of nitrate(NO3-) in ponds from one season to another by keeping a high concentration of oxygen in thepond water. This hypothesis was tested by doing a lab experiment where two systems werecompared according to nitrate concentration. One system had high concentration of oxygen inthe water and one had low concentration of oxygen. Before the main experiment wasconducted I did a pilot study to test the system setup and included parameters. The result fromthis study and the main study did not show the same result.

The project has been provided by Zenit design group and the goal for this project was tomanufacture and perform tests of a prototype that supersaturates water in a continuous flow ofwater. The project has involved finding and sorting out relevant data in scientific papers, books,communication with foreign manufactures and other platforms for information.The project has resulted in manufacturing of a test rig and an oxygen infuser based onmembrane technology. The test rigs purpose was to perform tests on oxygen infusers fordifferent comparison test and performance benchmarks in a in a laboratory provided by Zenit.The project led to satisfying results using the oxygen infuser manufactured by the authors withcomparable levels of saturation to the reference infuser.The theory behind this project is based on medical research, belonging terms will be explainedbut the authors have chosen to delimit the project from the medical area. The reason for this islack of knowledge in this area and its irrelevance to the mechanical engineering education insuch..

Total organic carbon (TOC) and chemical oxygen demand (COD) are two methods used for measuring organic pollutants in wastewater. Both methods are widely used but the COD method results in production of hazardous wastes, including mercury.The purpose of this study was to validate the method TOC that will replace COD and find a factor to convert TOC to COD. In this study 26 samples were analyzed from four sewage treatment plant in the municipality of Enköping.The results show that the COD method could be replaced by the TOC method.The factor for COD/TOC was between 3.1 - 3.3. Both methods will be used in parallel until 2013 when it will be forbidden to use the COD analysis..

This master thesis in energy optimization was made during the autumn of 2006 at Käppala wastewater treatment plant in Lidingö, Stockholm. A preceding thesis, where all electricity consumption was mapped, showed that the aeration in the biological treatment is the single largest consumer in the plant, and it is therefore of interest to reduce this cost. The oxygen control strategy used at Käppala WWTP is working well from a nutrient removal point of view, but not from an economic one. The last aerobic zones have a very low oxygen consumption during low loading periods which give rise to enhanced dissolved oxygen concentrations with excessive costs and reduced denitrification as a result. But also during periods of normal loading unnecessary high oxygen concentration are sometimes given.By modifying the aeration control strategy three full-scale experiments have been made, with the intention to reduce the air consumption.

A wastewater treatment plant has the task to refine the wastewater from substances that should not be released into the environment. The decomposition process can, in a simple way, be described as follows: micro-organisms breathe oxygen and eat unwanted substances. The environment in which the micro-organism lives is known as sludge and the correct amount of oxygen available in the sludge is important for the decomposition to be effective. The oxygenation of the sludge alone stands for about 30% of the plant?s energy consumption.

The system tungsten-oxygen has potential of being suitable for decorative coatings since ceramic coatings are often hard and wear resistant, and since modulations in oxygen content or incorporation of small ions could give bright colours. The aim of this report was to investigate the relationship between process parameters and  the properties of the films, with the wear resistance being of special interest.Samples with tungsten to oxygen ratios in the range of 100:0 to 25:75 at% were made using reactive sputter deposition, either with constant gas flow, or gas flow controlled by optical emission of the plasma. The hysteresis of the system, which means that a certain gas flow will cause different pressure and/or target voltage depending on in what way the flow is reached, makes it interesting to control the process where the system makes the steep change from metallic tungsten to ceramic tungsten oxide. This is difficult and thus requires precise control equipment.The samples were analysed using X-ray diffraction, X-ray photoelectron spectroscopy and an empirical wear test suitable for small components like cell phone cover for example, in order to characterize the structure, composition and wear resistance of the coatings. The results could be divided into three groups: (I) tungsten-like, with very low oxygen content; (II) mixed phase and (III) tungsten oxide like, with oxygen content close to 75 at%.

AbstractTitle: Does supplementation with omega 3 improve oxygen uptake among athletes?Author: Jonna Gustafsson and Maria Bohlin Nygren Supervisor: Frode Slinde Examiner: Ingrid Larsson Programme: Programme in dietetics, 180/240 hp Type of paper: Bachelor?s thesis in clinical nutrition, 15 hp Date: May 26, 2015Background: Previous research has shown that omega 3 fatty acids may improve cardiovascular functions by decreased aggregation and increased red blood cell deformability. This produces an increased blood flow and could have a potential effect on oxygen uptake. Optimal aerobic capacity is a determinant factor of performance within endurance exercise.Objective: To compile scientific research of the possibility that omega 3 supplementation could improve oxygen uptake among athletes.Search strategy: The literature research is based on searches in PubMed and Scopus with the terms ?Physical Endurance?, ?Oxygen Consumption?, ?Fatty Acids Omega 3?, ?Dietary Supplements?, ?Exercise?, ?Fatty Acids Essential?, ?Docosahexaenoic Acids?, ?Eicosanoic Acids?, ?Fish Oils?, ?oxygen consumption?, ?maximal oxygen consumption?, ?VO2 max?, ?athlete?, ?omega-3 supplementation?, ?physical endurance?, ??-3?, ?omega-3?, ?Maximal Aerobic Power?, ?Oxygen Uptake?, ?VO2? and ?Maximal Aerobic Capacity?.Selection criteria: Randomized controlled trials (RCT) with an intervention of omega 3-supplementation during three weeks or more were included.

Deicing fluids based on Propylene glycol are used at Stockholm Arlanda airport to remove or prevent ice on aircrafts. The high oxygen demand of propylene glycol can cause oxygen depletion in rivers downstream from the airport if not collected. Mass balance calculations made by Swedavia indicate that the actual amount of gathered propylene glycol is underestimated. Suspicions that propylene glycol is degraded in the stormwatersystem designed to collect deicingfluids, called the B-glycolsystem, have to be investigated in order to establish with certainty that no propylene glycol in other ways leaves the B-glycol system.The purpose of this study was to determine if degradation of propylene glycol is present in the B-glycol system and also to estimate the extent of the degradation. Propylene glycols high biological oxygen demand can cause oxygen depletion in waters downstream from Stockholm Arlanda airport if not collected.

The purpose of this master thesis is to examine a proposal for basic class 4 in UDC, which has been empty since 1964, and to pick out a negotiable subject for that proposal. The proposal is analysed from a theoretical perspective based on principles created by S. R. Ranganathan. Three principles are used.

Background Atelectasis is a commun respiratory complication related to general anesthesia and may contribute to pneumonia and acute respiratory failure. Atelectasis apear within 10 minutes after anesthetization and occur in 90% or more anesthezied patients regardless of age and gender. The aim of this study was to indentify if there are any evidence for which methods are ultimate or are most efficacious to reduce and prevent the formation of atelectasis.                                                                                                          Methods This study is a descriptive litterature study where 28 scientific studies have been indentified for review and analysis.                                                                                                               ResultsThe use of 100% oxygen during the induction of anesthesia favors the developement of atelectasis. This can be prevented by preoxygenation with oxygen content of 100% combined with a PEEP of 6-10 cmH2O. When free airway is secured, oxygenation with 100% was found to be unnecessary.

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Yeast and Clostridia is a problem in silage for farmers as contaminated silage may result in poor animal health and milk quality. Clostridia can produce toxins that, when consumed, acts as neurotoxins, it may also cause blown cheeses if the Clostridia contaminates milk. The purpose of this study was to investigate the cause, effect and interaction of yeasts and Clostridia in silage. Clostridia are microorganisms which are strictly anaerobic and consume carbohydrates and protein in the silage. Yeast is a fungus that is facultative aerobic and feed on carbohydrates in the silage.