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336 Uppsatser om Chemical Vapour Deposition - Sida 13 av 23

Micro plastics in the oceans and their effect on the marine fauna

Small pieces of plastic, termed ?micro plastic? in the oceans derive mainly from degradation of big plastics such as beach littering, but also from sources of direct emission from e.g. beauty scrubbers and synthetic sand-blasting. These micro plastics are ingested by marine animals ? mistaking them for plankton ? or via prey.

Sjuksköterskors arbetsmiljö inom slutenvård och äldreomsorg : En litteraturstudie

AbstractThe aim of this study was to illuminate and collect existing research from the beginning of the 21 st century about nurses work environment in institutional and elderly care in Sweden.A literature review was made by analyzing eleven scientific articles. The result showed mainly information about nurses work load. The information dealt with high work demands, too much responsibility, shortage of staff, time press and stress. Furthermore nurses reported a lack of co-operation between staff and management. An important part in nurses? work was appreciation from colleagues, management, patients and relatives.

Storjuktan ? Rekonstruktion av ett sekels kvicksilverbelastning. : En undersökning av kvicksilverkoncentrationer i daterat bottensediment.

The aim of this study was to examine the current and historic mercury(Hg) load of the lake Storjuktan due to its recent exposure to a local potential source of Hg in form of the Sulphide mine Blaikengruvan(2006) and an earlier potential sources of Hg-load, the damming of the lake(1960s). Sediments were extracted using a HTH-sampler, freeze-dried, and analyzed for tot-Hg, LOI and activity of 210Pb and compared to samples extracted prior to the opening of the mine(2006). Constant initial concentration (CIC)-dating model was used for dating the samples. Low levels of Hg (100ng/g) were found throughout the lakes sediment. The highest levels of Hg(220ng/g) was detected at a depth of 4-5cm dating back to the mid 1970:s, suggesting that increased levels of atmospheric Hg rather than damming of the lake has caused the increase of Hg.

Kemikalier på förskolor : En studie om hormonstörande ämnen och medvetenheten hos förskolepersonal

Chemicals in preschools - a study of endocrine disrupting chemicals and awareness among preschool teachers The purpose of this study was to investigate endocrine disrupting chemicals that have been shown in preschools and also the preschool teachers? awareness of these chemicals. There were two methods used for completing this study; a literature study and a practical study. The literature study was made by researching on the internet and in books. The practical study was performed by sending questionnaires to all preschools in Kiruna municipality to study awareness among staff.

Effekten av Bisfenol A (BPA) på hanråttors (Rattus norvegicus) reproduktion

Today evidence exist that environmental chemicals deteriorate male sperm quality and that testicular cancer is increasing. Bisphenol A (BPA) is a chemical with estrogenic effects used in the manufacture of polycarbonate plastic and are found in, for instance, plastic boxes, feeding bottles and food containers. Much of the research on how men's reproductive ability is influenced are performed on rats. This review article complies how male rat reproduction is affected by BPA as a model for humans. Studies have investigated how sperm are affected, hormonal changes during reproduction and how reactive oxygen species (ROS) affects sperm.

Establishment and evaluation of a Barley starch isolation method with focus on representability

The high viscosity of barley material makes starch isolation problematical using regular methods established for cereals. An adjusted starch isolation method has been set up for barley, based on fractionation and purification. The focus is on attaining truly representative isolates of six flour samples selected for widely differing characteristics within the research program BarleyFunFood (BFF). Beside establishment of the method, this diploma work aspires to serve the BFF with isolated material of sufficient yield valid for further starch characterisation. A pre study was conducted evaluating available wet mixing equipment, experimental conditions and mode of procedure.

Validation of realtime-PCR of Fusarium avenaceum for detection in wheat

Mould is a common contamination in cereals. The growth of mould can stimulate mycotoxins production andsome of which at critical concentrations cause health problems in humans and animals. Fusarium is one of thefungus species that has been found in crops and can cause major problems for farmers such as reduced harvestand economic losses. A group of Fusarium species, Fusarium avenaceum, Fusarium poae and Fusariumtricinctum express a mycotoxin, enniatin. The limited information available today about enniatin-forming fungiis that they grow out on fields of wheat in colder climates.

Dubbelkönighet hos mört : normalt eller miljöinducerat?

A number of chemical agents, and their degradation products, have been recognized as having estrogenic activity on animals. On fish they interfere with endogenous estrogen and in many cases mimic its activity, thus increase estrogenic reponse, with elevated levels of vitellogenin. Hence they are called Endocrine Disrupting Chemicals, EDCs. Vitellogenin levels is often used as a biomarker of exposure to estrogenic pollutants. Wastewater from sewage treatment works contains chemicals known as EDCs, and there are evidence of roach (Rutilus rutilus) living in recipients of such wastewater having traits of both gender, i.e. oocytes in male gonads (intersex) on histological examination. This study was done on roach living in Lake Funbosjön Uppland, Sweden.

Side effects of biological control agents in agriculture : does the bacteria Bacillus amyloliquefaciens affect the earthworm Aporrectodea longa?

Pathogenic microorganisms pose a big threat towards food production. Meanwhile, negative impacts on humans and environment are seen by the use of pesticides. Biological control agents are an alternative to the use of chemical pesticides, and plant-growth promoting rhizobacteria, such as Bacillus amyloliquefaciens has been shown to have good properties as biocontrol agents. Before these bacteria can be used commercially their impact on other soil organisms has to be evaluated. This thesis looks into what biocontrol bacteria are and how they might affect earthworms.

Behandling av lakvatten med kemiska oxidationsmedel för att delvis bryta ned oönskade organiska förening : en studie utförd vid Hovgårdens avfallsanläggning i Uppsala

A renewed application for environmental permit for the Hovgården landfill in Uppsala shall be submitted before December 2004, therefore the municipality of Uppsala needs improved knowledge of the contents, mostly organic compounds in the leachate and they also want to find a method to minimize the emissions of these compounds. The purpose of this study was to find a practical and economical method based on chemical oxidation using oxidants. The oxidants investigated are Fenton's reagent, hydrogen peroxide, Oxypro, potassium permanganate and potassium persulfate. The study was made on untreated leachate and leachate that has been treated in an aerated dam followed by sedimentation dams collected from the Hovgården landfill, and alson on sludge water from sludge storage cells. The effects of the five oxidants have been established by analysing the UV absorbance at the wavelengths 253,7 nm and 260,0 nm at different pH values. The UV absorbance was used to indicate the amount of aromatic hydrocarbons in the water. Also analyses of iron and manganese were done after the experiments with potassium permanganate, hydrogen peroxide and Fenton's reagent.

Utveckling av HPLC-metoder för kvantifiering av nyckelkomponenter i en villkorad emulsion

Traditionally, rolling mills use emulsions based on a mixture of oil and water for lubrication. Since two years ago SAPA has been using (instead of oil) a synthetic lubricant so called conditional emulsion for hot-rolling of aluminum. This lubricant is water based and homogenous at ambient temperature, but switches to a two-phase system at heating above the cloud point.This project aims to validate and if necessary modify an existing HPLC method for quantifying two out of three key components (A, B and C) in the conditional emulsion. Attempts to develop a method to quantify the pH adjusting components, X and Y were also made. These two methods are required to optimize the lubricant.Due to the complexity of the components, it has been difficult to present a method for quantification, and HPLC with ELS detection was chosen after a long series of trials.

I vatten eller jord? : Nytolkning av depåfyndet från Eskelhem

In 1886 Hans Hildebrand received a Bronze Age hoard found in a field that belonged to Eskelhem´s rectory. A record was made where Hildebrand presented and documented the artifacts. The following year Oscar Montelius reviewed the artifacts, which he described as horse gears. He compared the horse gears with similar artifacts found in Europe that roughly had the same dating in order to trace the origin of the hoard.  Montelius conclusion was that the hoard was created on Gotland around 500 BC.

Livet efter sfi : Vilka tankar har några sfi-elever om sin delaktighet i det nya landet och hur har de lyckats med att förverkliga uppsatta mål?

Boplatsvallar, often translated as semi-subterranean settlements, is an ancient monument with a diffuse definition. Defined as ?embankments that partially or completely surround a often lowered/dug down surface- this category of ancient monuments is also made up of a former category which traditionally was interpreted as winter settlements from the late Stone age in Sweden. This view of the ancient monuments carried over, to a certain extent, to this new definition. Should this be the case, that this category of ancient monuments are remains of winter settlements,  used recurringly over an extended period of time, then they should exhibit similar signals in regards to the distribution of the anthropogenically altered soil chemical and soil physical properties at the sites.The area around Lillsjön, Anundsjö parish in Ångermanland, have four boplatsvallar located separately in the regional area.

Uppfyller BIM förväntningarna som arbetsmetod för broprojekt?

The purpose of this work is to design and construct a device able to measure the mechanical attrition of oxygen carrier particles. Those particles are used in chemical looping combustion and in the present situation there is a lack of knowledge in how the attrition process work and in which extension. To find already tested solutions trying to answering this problem a literature study wascarried out and the best solution found was the so called Grace-Davison Jet-Cup method. This method is supposed to emulate the attrition caused by a cyclone separator and its advantages are that it is possible to use small test amounts, 5-10 g, and a thirty minutes long test will be enough to acquire useable results. An device was designed based on the Jet-Cup method with some slight modifications.

Amyloid beta inducerad klyvning av NG2 medierad via LRP-1 receptorn

Bakgrund: Deposition av fibrillär amyloid beta 1-42 (A?) i hjärnan är ett välkänt kännetecken för den neurodegenerativa sjukdomen Alzheimer?s (AD). Dessa ansamlingar påverkar pericyter, en celltyp involverad i blodkärlsfunktion och upprätthållande av blodhjärnbarriären (BBB). Pericyter uttrycker både receptorn low density lipoprotein receptor related protein 1 (LRP-1) till vilken A?1-42 binder, och proteoglykanet NG2.

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