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249 Uppsatser om Zink layer - Sida 13 av 17
Short-term responses of the field layer vegetation in a south Swedish deciduous forest after establishment of wild boars (Sus scrofa)
Inside the south Swedish national park Dalby Söderskog, wild boars (Sus scrofa L.) have been visiting since 2010. The presence of wild boars has earlier been proven to
impact both soil and vegetation characteristics, both positively and negatively. Still, there is a lack of knowledge regarding the rooting effect on the vegetation in
deciduous forest within the native range. In this study, I have compared the field vegetation collected before and after the invasion of wild boars in 74 permanent experimental plots. More specifically, the study aimed to qualify the effect of wild boar rooting on cover ratio, species richness and species composition in a temperate
deciduous forest.
Infectious bronchitis in Brazil : a minor field study in Bastos municipality, Sao Paulo
Infectious Bronchitis (IB) is a highly contagious viral respiratory and productiondepressant disease distributed world wide. The disease is caused by the InfectiousBronchitis Virus (IBV), a positive RNA strand Avian Coronavirus within thegenus Gammacoronavirus. Due to a combination of high mutation rate and atendency of recombination a constant emergence of new genotypes and serotypesis seen. In Brazil, a country with an extensive poultry production and majorproblems with disease control, the diversity of circulating strains are wide andoutbreaks of clinical disease despite intensive use of vaccines are common. Theaim of this study was to investigate the presence of IBV and to identify genotypesof isolated IBVs in a limited number of layer flocks in Bastos, São Paulo, as partof the screening for circulating genotypes in the country.
En studie av SSL
Dokumentet är ett resultat av studier gjorda under kursen Kandidatarbete I
Datavetenskap. Arbetet utforskade, genom fallstudie, två egenskaper av
distribuerade informationssystem och relation mellan dessa: säkerhet och
prestanda. Målet med fallstudien har varit att belysa nackdelen med användning
av Secure Socker Layer (SSL) dvs. dess effekt på hastigheten och fördelen med
SSL, dvs. SSL:s roll i informationssäkerhetsarbetet.
Arbetet visar hur prestanda i ett tillämpad distribuerat informationssystem kan
påverkas av en SSL tillämpning.
Effect of liming and free Ca2+ on Cd uptake of carrots, Daucus carota
The level of cadmium (Cd) in Swedish arable land has increased during the last century and the average concentration of Cd in the plough layer is today 0.23 mg/kg. The increase is mainly due to anthropogenic activities such as phosphorus fertilizing, liming, import of feed, and atmospheric deposition from industrial emissions. Cadmium in the soil will be taken up by crops and is thereby transferred to humans via food. Carrot is one of the crops of concern, both because it may contain quite high Cd concentrations and due to the large consumption in Sweden. In the body, Cd is stored mainly in the liver and the kidneys and may cause several diseases already at low concentrations.
Indirekta effekter på marklavars abundans och diversitet vid ökad kvävehalt i marken : en jämförelse mellan opåverkad och lågintensivt brukad mark
Lichens are adapted to bright and sparse forests on oligotrophic ground. Due to a slow growth rate and high light demand lichens will suffer from competition in eutrophic environments. Therefore, lichens have disappeared from managed forests where the forest industry has increased the productivity. A reduced abundance of lichens will affect both biodiversity of the forest and the reindeer winter graze lands. It is important to understand how and for how long fertilization affects the abundance and diversity of lichens in order to protect lichen rich ecosystems.
We have registered the biomass and number of lichen species in eight plots (four nitrogen rich and four nitrogen deficient) and compared fertilized Sami settlements with their oligotrophic surroundings in the nature reserves of Tjeggelvas.
The secret life of Bacillus anthracis
Bacillus anthracis is the causative agent of anthrax, a serious and globally distributed zoonosis affecting a wide range of wild and domestic animals, invariably also humans.
However, although known to humans since biblical times, much remains to be elucidated concerning the ecology and transmission of this bacterium. Of particular interest is the Bacillus anthracis spore, the uptake of which is the predominant way to contract anthrax and which is legendary for its resilience in the environment and thus crucial for persistence and spread of the disease. Hence, the aim of this study is to review the natural transmission of
Bacillus anthracis and investigate potential means by which soil persisting Bacillus anthracis spores reach concentrations sufficient to infect susceptible hosts. When reviewing the literature, three different theories can be distinguished. Firstly, ?the incubator area? hypothesis suggests that favourable soil factors, possibly in association with amoebas, may constitute an environment supporting repeated spore-bacterium-spore cycling, thus increasing the local amount of spores.
Kläder i hampa - ett miljövänligt alternativ/komplement till bomull?
Hemp has been used for textiles for a long time in history until it became illegal to grow in many countries in the 1930s. It is interesting from an environmental point of view because it doesn?t need any pesticides and in most locations it doesn?t need any irrigation either, compared to cotton, which normally requires big amounts of both pesticides and water for irrigation. Hemp is a bast fiber, which means that the fibers are located on the bast of the stem (on the outer layer of the stem). Therefore they cannot be spun directly, they have to be removed from the stem first.
3D-modellering i AutoCAD -att skapa en digital huskonstruktion
3D-modelling in AutoCAD This thesis is done in cooperation with LB-Hus in Bromölla, and have aimed to establish a digital AutoCAD model of one of the company?s house types and to find out what opportunities there are to do visualisations in the form of images directly from the programme. Modeling has been carried out so that the very construction of the house is included. Interiors and installations, with the exception of the ventilation system, have been left out in the model. The model has been created with solid models after a comparative study made between solid models and surface models to find out which option in this case was the easiest to handle and took up the least space.
Ägarlägenheter i miljonprogramsområden : - Ur ett förvaltningsperspektiv
AbstractIn November 2011 the Swedish Government announced that they were conducting an investigation to examine what impact the conversion of existing rental stock to condominiums could have on the development of the Million programme areas. The proposal of converting rental stocks to condominiums aims to help people living in these neighbourhoods to private ownership, while still allowing people who want to continue to rent their homes to do that. This thesis intends to investigate the effects of the proposed reform from a management perspective. The maintenance of the areas built during the Million Programme gets more neglected every year that passes. The majority of the housing stock is rental properties and extensive renovation of the surface layer, tribes and public spaces are essential in all Million programme areas studied. By transforming a portion of the housing stock into condominiums and by improve the living environment through renovations, these areas would be able to gets more attractive.
Riskbedömning vid Saltvikens kopparverk
AbstractAt Saltvikens copperindustry, which is located in the municipality of Oskarshamn, copper was refined from sulphiteore some hundred years ago. The ore underwent several steps in the process before the final product was received. These steps all had an influence on the environment through discharge of heavy metals. The area where the copper industry was located is today considered to be of specific national interest due to its valuable nature and cultural values, as well as its value for recreational outdoor activities. Therefore, it is important to determine the present level of contamination and if any transport of contaminants have occurred, and to identify the risks that are associated with the site both at present and in a longer time perspective.Thirtynine soil samples and 16 sediment samples have been analyzed.
Utredning om huruvida Dalarnas Tidningars produktion passar en KBA Cortina
This degree project illustrates newsprint and waterless offset. A new news press was introduced at Drupa-00, Cortina from KBA, which is the first news press dedicated the waterless technique. With actual statistics from the company in question an investigation was made whether their production fits this press. It came out in the investigation that the production of the company, from statistics, fits this press very good. A table was made where different timeschedules were accounted for the new press, with semi- and full automatic plate changing for present and to be added papers.
Livslängden hos kyllagrade spermier vid artificiell insemination hos häst - kan den förlängas?
Över 90 % av betäckningarna inom Avelsföreningen för svenska varmblodiga hästen (ASVH) skedde med artificiell insemination (AI) år 2011. AI har många fördelar i avelsarbetet då hingsten inte behöver vara på plats när stoet brunstar, möjligheten att välja bland både nationella och internationella hingstar ger en stor valmöjlighet för stoägaren. I Sverige samlas sperma från hingstarna normalt sett tre gånger i veckan genom upphopp på en fantomhäst där ejakulatet samlas i en artificiell vagina. Trots mycket forskning är det fortfarande ca 20 % av hingstarna som lämnar spermier som inte lämpar sig för frysning.
Innan nedkylning centrifugeras seminalplasman bort eller späds ut för att reducera inverkan på spermierna. Seminalplasman har positiv inverkan på spermierna vid naturlig betäckning men kan ha negativ inverkan på spermierna under lagring.
Optimering av ommalning i en flotationskrets i anrikningsverket i Boliden
Detta examensarbete för högskoleingenjörsexamen i Berg och Mineralteknik utfördes på uppdrag av Boliden Mineral AB under perioden från april till juni 2013.Rapporten beskriver Bolidens gruvors historia och uppkomst samt utveckling av ett av Sveriges största metallföretag, Boliden. Vidare beskrivs Skelleftefältets geologi där Boliden finns. Här finns många viktiga malmfält som innehåller guld, zink, koppar, silver och bly.Målet med examensarbetet var att undersöka och ge riktlinjer för förbättring av ommalningen i en kulkvarn i anrikningsverkets flotationskrets för att förbättra processutbytet.Rapporten följer malmens väg från gruvan genom anrikningsverket och vidare till slutprodukten. I den beskrivs metoder och utrustning för utvinning och i anrikningsprocessen.Genom att noggrant följa malmens väg analyserades alla moment som kan påverka anrikningsprocessen. Det upptäcktes att det finns problem med malmupplaget i gruvan och segregering av fraktioner i silon.
Flödesanalys av spårelement från källa till slam
I det svenska samhället tillför diffusa och direkta föroreningskällor metaller till avloppsreningsverk, metaller som sedan hamnar i avloppsslam och recipient. Avloppsslam innehåller höga halter av växtnäringsämnen som bör återföras till jordbruksmark, men om detta ska ske får inte metallhalterna i slammet vara för höga. REVAQ är ett certifieringssystem vars syfte är att utveckla och systematisera avloppsreningsverkens uppströmsarbete och därmed möjliggöra en återföring av det växtnäringsrika slammet till jordbruksmark. Flera REVAQ-certifierade avloppsreningsverk prioriterar antimon, guld, kadmium, silver och vismut i uppströmsarbete på grund av att ackumulationshastigheten för dessa spårelement är hög i jordbruksmark som gödslas med avloppsreningsverkens slam. Source Finder (SoFi) är ett verktyg som kan användas vid uppströmsarbete för att kvantifiera identifierade källor till utsläpp av kadmium, koppar, krom, kvicksilver och zink.Syftet med examensarbetet var att vidareutveckla och anpassa verktyget SoFi till att göra beräkningar på spårelementen antimon, guld, silver och vismut samt att utveckla källan hushåll så att emissioner inom hushåll kartläggs för spårelementen och kadmium.
Undersökning av bindningsmekanismer vid pressning av metallaminat : Investigation of bondning mechanisms at the pressing of metal laminates
Increased understanding of the mechanisms that operate in conjunction with the welding of metal surfaces may help to improve existing manufacturing processes, and to enable new products and combinations of materials. The purpose of the project has therefore been to acquire a deeper understanding of what is happening in the bond for steel and for the factors that form the basis for a bond to develop between metals in the production of laminates by pressing. The merge has been done by pressing and the surfaces after the experiments have been studied in detail in the scanning electron microscope (SEM), energy dispersive X-ray spectroscopy (EDX) and with interferenceprofilometry in Wyko, to provide a greater understanding of the mechanisms that influence the bonding in the interface between metals. The project was limited to contain the materials Docol 1000, HyTens 1200, Aluminum AA3003 and a commercial steel. The parameters varied in the experiments to study their influence closer are temperature, pressure, heat treatment and pretreatment. This has been implemented by pressing with varying temperature and pressure.