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353 Uppsatser om Chemical precipitation - Sida 14 av 24

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.

Spatiella mönster och lager av organiskt klor och klorid i barrskogsjord i sydöstra Sverige

The concentration and storage of organic chlorine and chloride were determined in soil, to a depth of 40 cm, in a coniferous forest in the Stubbetorp catchment area in south-east Sweden. Also, the spatial distribution of the two forms of chlorine was determined. Soil samples were collected at 49 of the nodes in a grid with approximately 105 m between the nodes. The analysis of spatial variability suggested that no spatial autocorrelation was present either within the variable organic chlorine or chloride. This means that no sample was more influenced by another nearby sample, as compared to other samples further away.

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.

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.

En ?terinventering och analys av den svenska populationen av svart nervmossa (Campylopus atrovirens)

Bristly swan-neck moss (Campylopus atrovirens) is in Sweden a very rare moss that only grows on a few blocks and cliffs around Gothenburg. The species can globally only be found in areas with high precipitation. Rain fall in Gothenburg has increased with a stronger greenhouse effect. Air pollution in Gothenburg has also improved. Mosses generally benefit from these conditions and this papers hypothesis is that the population of the species has grown because of these more beneficial conditions.

Miljöcertifieringssystemet Miljöbyggnad : Inverkan på utformningen av ett kontor

The use and attention given to the certification system ?Miljöbyggnad? has increasedin recent years. The system is completely Swedish and was initiated in 2005 by theBygga-Bo-Dialogen. Miljöbyggnad aims to create a healthy indoor environment, reduceenergy consumption and discourage the use of hazardous chemical substances. Thegrades that can be obtained are Classified, Brons, Silver and finally Gold.The work has been to examine three different models and conclude how the designof the models affect the grades in the certification system Miljöbyggnad.

Eutanasi : en skonsam död

This work is about euthanasia and how to use it on horses, dogs and cats. A description for each animal is done, about when it is time, why, which methods can be used and who is allowed to use them, how and where it shall be done. The methods we have concentrated on are: - Chemical destruction and the most common drugs for euthanatize horses, dogs and cats. - Physical disruption of the brain activity by a captive bolt, only for horses. The captive bolt only makes the horse unconscious and must always be followed by cutting off the vena jugularis. Then the horse dies because of loss of blood. No matter which method used for euthanizing, the animal must be declared to be dead by the operator before other measures. The testing criteria for death: muscle relaxation and cyanosis, cessation of reflex activity and pupillary dilatation, cessation of respiratory activity and cessation of all cardiac activity.

Foderhäckar till hästar i lösdrift :

Knowledge about feed racks for feeding forages to horses is lacking. Racks for sheep and cows are sometimes used for horses. Feeding roughage on the ground, or feeding silage bales with the plastic and net still on, can bring on a lot of different problems. The opportunity to control the hygienic quality is small and feed losses can be high. The purpose of this experiment was to investigate how the eating behaviour and consumption of horses were influenced by feeding racks of different constructions. Feed losses and changes in chemical composition of the forage were also studied.

Aquaculture : animal welfare, the environment, and ethical implications

The aim of this review is to assess the ethical implications of aquaculture, regarding fish welfare and environmental aspects. The aquaculture industry has grown substantially the last decades, both as a result of the over-fishing of wild fish populations, and because of the increasing consumer demand for fish meat. As the industry is growing, a significant amount of research on the subject is being conducted, monitoring the effects of aquaculture on the environment and on animal welfare. The areas of concern when it comes to animal welfare have here been divided into four different stages: breeding period; growth period; capturing and handling; and slaughter. Besides these stages, this report includes a chapter on the current evidence of fish sentience, since this issue is still being debated among biologists.

Foraging behaviour of cattle, sheep and goats on semi-arid pastures in Kenya

ABSTRACTThe principal aim of the study was to compare the feeding behaviour of cattle, sheep and goats on pasture and explain any differences between speices. Furthermore, I compared foraging behaviour between dry season and the beginning of the rainy season, in order to see any relationships between weather and behaviour.The study was carried out in Shompole in southern Kenya. Behavioural data were collected by observing herds of cattle, sheep and goats on pasture. The livestock were herded on pasture during the days and kept in bomas, where people live, during the nights. The weather in Shompole is characterized by high ambient temperature and low, bimodal rainfall.

Vattenkemin i Fyrisån under snösmältningen

Chemical substances are spread diffusely and uncontrollably as a result of the increased consumption of goods. REVAQ is a certification system that works to reduce the flow of hazardous substances to Swedish treatment plants and to create a sustainable nutrient recycling. According to REVAQ, the yearly accumulating rate of metals should not exceed 0.2% in soil per year. Silver and bismuth are two metals that do not fulfill this requirement. The silver concentration in sludge decreased during the last decade, however the last few years, it has leveled off.

Sederingsrutinens påverkan på resultatet av höftledsröntgen : en pilotstudie

Hip dysplasia is a common, inherited malformation of the coxofemoral joint that eventually leads to osteoarthrosis. Several breeds of dogs are affected and the prevalence varies between different breeds. As part of the effort to reduce the prevalence of hip dysplasia and select dogs suitable for breeding, radiological screening is performed by at least 12 months of age. Before the radiological examination the dog has to be chemically restrained, sedated or anesthetized. The sedation protocol used differs between veterinary clinics. The impact of sedation method of the screening result for hip dysplasia has been studied.

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