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189 Uppsatser om Perfluoroalkyl substances - Sida 1 av 13

Perfluoroalkyl substances in Arctic birds : a comparison between glaucous gulls and black guillemots from Svalbard

Perfluoroalkyl substances (PFASs) are ubiquitous in the environment today and they have been detected even in remote areas such as the Arctic. PFASs can be transported by the atmosphere and ocean currents but the transport mechanism is not fully understood. PFASs may be harmful to organisms due to their persistence in the environment, bio-accumulation potential and toxicity. Studies have shown that PFASs can cause adverse effects on the metabolism as well as the endocrine- and reproduction systems in organisms. In this study, PFASs were investigated in glaucous gull (Larus hyperboreus) (n=5) and black guillemot (Cepphus grylle) (n=4) from Svalbard.

Removal efficiency of perfluoroalkyl substances (PFASs) in drinking water : evaluation of granular activated carbon (GAC) and anion exchange (AE) using column tests, and the effect of dissolved organic carbon

Poly- and Perfluoroalkyl substances (PFASs) are a group of environmental contaminants that have gained increasing attention due to their potential to bioaccumulate, environmental persistence and potential toxicity. PFASs have been found in surface water, sediment, air, soil, sludge and ice caps globally, as well as in wildlife and humans. Furthermore, PFASs have also been detected in drinking water, leading to raised concerns for human health, since drinking water is one of the most significant sources of PFASs for the general population. Conventional water treatment techniques have shown to be ineffective removing PFASs, highlighting the importance for further research to develop efficient removal techniques. The aim of this study was to investigate the removal efficiency of PFASs in water using two treatment techniques; granular activated carbon (GAC), type Filtrasorb 400®, and anion exchange (AE), type Purolite A-600. Additionally, the effect of dissolved organic carbon (DOC) on removal efficiency was studied.

Kan perfluorerade ämnen i kläder bidra till förhöjda halter i reningsverk?

Perfluorinated substances (PF) are environmental pollutants that are used to coat fibres of so called ?all weather clothes? to make them water resistant. PF are effectively spread through water. Waste water treatment plants (WWTPs) are a pollutant source of these substances. PF are poisonous to different kinds of organisms, and supposedly also to human beings, if concentrations are sufficiently high.Perfluorinated substances have been investigated at three waste water treatment plants in Stockholm during the 2000?s.

Use of dogs as odour detectors : a review of the scientific literture

A lot of various substances can be detected by dogs, as oestrous in cows, endangered species or non-biological substances like accelerants, narcotics, explosives, mines and pollutions and biological substances like identity (suspects), cancer (breast, lung, colorectal and bladder cancer), human remains (cadaver), bacteria and mould in buildings. The dogs are trained using non-scientific methods and not much research in detection training exists. This is a review of different types of dog detection, with focus on new research..

Systemidentifiering och reglering av en luftningsbassäng på ett reningsverk

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.

Identifiering av lakbara potentiellt farliga ämnen i gummiasfalt

The main purpose of the project was to identify potential environmentally harmful substances which can be leached from rubber asphalt. A method for analysing asphalt was developed and three rubber asphalt materials were analysed after being cryogrinded. One of the materials was also tested in a road machine made for testing of asphalt paving. The particles created in the machine were analysed in the same manner as the cryogrinded asphalt materials.The asphalt materials were leached by water during 24 hours. The leachates were extracted with dichloromethane, dried with sodium sulphate and concentrated to a small volume.

Förgiftningar hos hund och katt

Cats and dogs are often unattended by their owners both indoors and outdoors, and therefore there is always a risk that they will get hurt. In the past, poisoning cases was considered unusual, but nowadays they are considered more common. As a veterinary nurse, it is important to know the common symptoms of poisoning, especially when working with emergency veterinary care. A very essential part of the profession as a veterinary nurse is to inform pet owners about the potentially dangerous substances and how poisonings can be prevented. The purpose of this report was to find out what is written scientifically about some common poisonings in dogs and cats and to present available statistics that covers the number of animals poisoned by various substances in Sweden. Hopefully this essay can also be used as a handbook for professionals in animal health care and to assist in educating pet owners. The report mainly covers groceries found in many homes, often easy accessible.

Individualiseringens dilemma : Hur uppnås ett fungerande samspel mellan individualisering och gemensam undervisning i matematik?

Abstract.The levels of dioxin and comparable substances rose to a large extent in our environment during the second half of the 20'Th century. This was the result of the synthesis of, and careless usage of these substances in cooling fluids, hydraulics, pesticides etc. Background levels of dioxins and furans in sealed samples prior to this era suggest that former sources of these substances existed. Salt glazing is a method of adding a smooth acid resistant exterior to stoneware ceramics. The technique has been in use since the 16'Th century, maybe even earlier than that.

Är saltglaseringsindustrin en källa till tidig organokloridförekomst?

Abstract.The levels of dioxin and comparable substances rose to a large extent in our environment during the second half of the 20'Th century. This was the result of the synthesis of, and careless usage of these substances in cooling fluids, hydraulics, pesticides etc. Background levels of dioxins and furans in sealed samples prior to this era suggest that former sources of these substances existed. Salt glazing is a method of adding a smooth acid resistant exterior to stoneware ceramics. The technique has been in use since the 16'Th century, maybe even earlier than that.

Systematisk limning av kartong

This report is a documentation of the workflow and the result of a project carried out by twostudents from the Royal Institute of Technology in collaboration with a company. The report isstructured in a chronological order and describes the methods and systems developed in theworkflow. The report shows how the project evolved from a study phase to the various proposals onthe concept solutions.The project aims to develop a systematic way of bonding two different kind of cardboard under fiveminutes. By conducting a general study about glue and its different forms it was possible to obtain abroad knowledge, which helped to choose the right substances to later use in testing on the differentcardboard materials in question. Glues's survey resulted in a list of different substances that wererelevant to the project.

Feromoninnehållande substansers effekt på hjärtfrekvensen hos kvigor i östrus och diöstrus :

With increased milkproduction in our dairy cattle, comes a risk for a reduced fertility. Studies performed on animals and humans have shown that it is possible to manipulate the oestrous cycle through exposure to pheromones. This means that pheromones could potentionally be used to make reproduction more efficient. To evaluate the bioactivity of the substances in question, there is need for a bioassay. In insects, pheromones can induce a changed cardiac activity.

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.

Kemin bakom framtidens avgasrening : En studie av ureasönderfall under kvävgasatmosfär

The purpose of this work was to provide a better understanding of urea?s decomposition and byproduct formation in an SCR system on heavy trucks. In my experimental setup with TGA-DSC-FTIR (a combination of two thermal analysis methods and a method for gas phase detection), an FTIR method for urea in the gas phase was developed for the qualitative and quantitative determination of urea and its decomposition products. Chemicals such as urea, biuret, cyanuric acid and melamine of p.a. quality were used in this method development. Beforehand, there was no FTIR method available to detect these substances; hence, the aim of this work was to develop an FTIR method to understand the degradation chain of urea. The combination of TGA and DSC was used for analysis of different samples, where urea, biuret, cyanuric acid and melamine in varying amounts have been weighted in for various experiments in order to study the temperature at which a phase transition or reaction occurs, i.e.

Kemiskt försvar mot havstulpanskolonisering i marina svampdjur

The purpose of this project is to analyze and study the absorption of the substances ivermectin, spinosad and barettin to hydrophobic and hydrophilic surfaces, and to analyze and study if the barnacle larva are effected when they try to settle on the treated surface.Incubation tests with barnacle larva in Petri dishes were performed as well as absorption tests on hydrophobic and hydrophilic surfaces which were tested with ellipsometry. To determine the surface thickness.The barnacles were placed in hydrophobic as well as hydrophilic Petri dishes that had been incubated with ivermectin, spinosad or barettin. After four to six days the larva was counted to analyze the settling. From the results conclusions could be drawn about the adsorption abilities of the substances to the different surfaces.The barnacles were placed in hydrophobic as well as hydrophilic Petri dishes that had been incubated with ivermectin, spinosad or barettin. After four to six days the larva was counted to analyze the settling.

The screening for novel proteasome inhibitors as a treatment of cancer using IncuCyte FLR and fluorometric microculture cytotoxicity assay.

The problem of finding targeted medicine is a central problem in chemotherapy. From this point of view the ubiquitin-proteasome system is a highly promising object in the pharmaceutical approach. Proteasome plays a critical role in cellular protein degradation, cell cycle and apoptosis regulation.Proteasome inhibitors are substances blocking the actions of proteasome. Cancer cells are more sensitive to inhibition of the ubiquitin-proteasome system than normal cells. Therefore proteasome inhibitors have the potential to be successfully used in the cancer treatment.The study aimed to test various substances to identify possible proteasome inhibitors with the IncuCyteTM FLR image system and fluorometric microculture cytotoxicity assay.

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