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349 Uppsatser om Chemical pulp - Sida 13 av 24

Luftburna gifter som kemiskt stridsmedel : En jämförelse mellan moisternas rökkrigföring under de stridande staterna och tyskarnas klorutsläpp vid Ypres den 22 april 1915

Kemisk krigföring i form av luftburna gifter har förekommit i många historiska kontexter. Trots att luftburna gifter, som till exempel giftig rök och gas är likartade företeelser, har inte forskare kunnat enas om äldre former av denna krigföring är jämförbar med den moderna. Huvudorsaken är att deras analyser saknar teoretiska perspektiv som belyser hur respektive   kontexts kemiska förutsättningar påverkar krigföringen.Syftet med den här undersökningen är att jämföra ett modernt nyttjande av luftburna gifter, tyskarnas första klorutsläpp vid Ypres 1915 med ett forntida exempel, den moistiska skolans användande av brandrök som gift under århundradena f. Kr. i Kina.

Rening av lakvatten vid deponin Degermyran i Skellefteå kommun : Utvärdering av nuvarande reningseffekt och simulering av mängden bildat lakvatten under 2000-talets klimatförändringar

At Degermyran landfill, situated in the municipal Skellefteå, a leachate treatment system was installed in 2005. One of the aims of this study was to investigate how well the treatment system works by using data from chemical measurements made on the leachate before and after treatment. Further this study had the purpose of investigating how the predicted climate changes of the 21st century will affect the amount of leachate generated at Degermyran by using a modified version of Thornthwaites water balance model. The treatment system has the ability of reducing manganese by 90 %, nitrogen by 73 % och TOC by 79 %. By the turn of this century the amount of precipitation that percolates the waste at Degermyran will be between 254 and 298 mm, depending on the amount of greenhouse gases that will be released in the future to come.

Brandsläckning och textil restvärdesräddning Hur saneras textil efter en pulversläckning?

This bachelor thesis discusses firefighting and the use of portable fireextinguishers in the salvageof historic artefacts focusing on textiles. It also looks into the use of multi-purpose dry chemicalextinguishers in a textile context and the impact the actual dry-agent has on textiles afterfirefighting.Literature studies, interviews and tests on different textiles were carried out to write this thesis.During the tests textiles were exposed to the dry agent and also to dry agent plus water toinvestigate the difference in residue. After vacuumcleaning it was clear that when the textile wasexposed to dry agent and water it was almost impossible to remove the chemical without rinsingin water.By examining the residue left on the textile using SEM it was possible to see if a textile was aswell decontaminated after vacuum-cleaning as it looks to the eye. We know that the dry agentoften consists of ammonium phosphate which acts corrosively on many materials and one canassume it damages textiles as well after longer exposure.Buildings housing cultural collections are vulnerable as we cannot easily replace ruined materialwith new.

Bedömningsgrunder och reningskrav för avloppsreningsverk, 25-2000 pe, i Laholms kommun

The aim of this project was to look into ten small sewer systems in the municipality of Laholm, in Sweden, in order to work out common assessment grounds for them. The sizes of the systems for purification of wastewater were within the range of 25 to 2000 population equivalents. Our method was to study literature, the laws and regulations applicable and the files at the municipality. The conclusion is that every sewer system is different and every situation is unique. We concluded that based on laws and assessment grounds sewer systems equal in size and pollution load ought to have similar demands attached to them.

Bioenergi från röjningsgallringar : en jämförande studie av fyra flödeskedjor från avlägg till förbrukare

When the Swedish Forestry Act was changed in 1994, brushing of young stands became non mandatory. Since then the annual need for brushing in the country has increased by about 100 000 hectares per year. In later years the price for biomass energy has increased to the same level as pulp wood. The high price on biomass energy and the large areas of stands in the need of brushing has created a new market with its own technical, economical and environmental conditions. There is a development of various techniques to manage the forestry stands with late brushing.

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.

Experimentell studie av kinetiken vid peroxidblekning av pappersmassa

Vid TCF-blekning av pappersmassa är väteperoxid en av huvudkemikalierna. I dagsläget är det svårt att styra blekstegen. Operatörerna måste ta hänsyn till produktionstakt, blekbarheten på massan varierar och fördröjning i trender. PO-bleksteget på Södra Cell Värö har en ungefärlig uppehållstid på 4 timmar och det är först efter så lång tid som man kan se hur en förändring verkligen slår igenom. Överblekning kostar väldigt mycket i kemikalieåtgång och det är därför efterfrågat ett sätt att kunna styra och optimera peroxidblekningssteget.

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.

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