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1031 Uppsatser om Degradation rate - Sida 13 av 69
Analys av designalternativ för snabbare dynamik i kolkraftverk med koldioxidavskiljning
Combustion of fossil fuels is today the dominating source of energy. During combustion,carbon dioxide is formed. The carbon dioxide accumulates in the atmosphere,which raises the global average temperature on earth through the so called greenhouseeffect. The only way to reduce the emissions of carbon dioxide from combustionin a coal fired power plant is through carbon capture and storage (CCS).Post-combustion capture is a technology to separate carbon dioxide from the uegas after the combustion for efficient transport and storage. The steady state operationof coal fired power plants with post combustion capture has already beenthoroughly investigated on a pilot scale, however much work remains to investigatethe plants dynamic operation.
Markberedningens, planteringspunktens och behållardjupets inflytande på granminiplantors etablering i fält :
A new type of forest tree seedling, called mini seedling, has been developed by the University
of Dalarna in Garpenberg, Sweden. Compared to traditional containerized seedlings
that are grown for 1 ? 2 years, mini seedlings are grown for only 10 weeks. The mini seedlings
are small, easily planted, cost effective, and reduce the amount of chemicals used in
the nursery. Research has shown that mini seedlings tend to have higher overall survival
rates than traditional container seedlings.
Följdeffekter av olika användningssätt för vedråvara : en ekonomisk studie
Since the turn of the millennium a sharp increase in the interest for bio energy has been observed. Important reasons for this growing interest can be due to the fact that fossil fuels are a finite resource. A net discharge of greenhouse gases occur when fossil fuels are burned. The discharge of greenhouse gases are considered to be the main reason to the greenhouse effect. Means of control to increase the use of bio energy has been introduced and, as intended, the use of bio energy has increased.
As a result of the legal provisions the ability to pay for bio energy has increased, which the forest industry view as a problem.
Kvinnors och mäns motiv och ambivalens till att donera ägg och spermier i Sverige
Involuntary childlessness is a big problem around the world. One way to solve the problem is to receive oocytes or semen from a donor. In Sweden, semen donation has been regulated by law since 1985 and oocyte donation since 2003. The aim of this study was to investigate what motivations women and men in Sweden have to donate gametes, if they feel any ambivalence to donate, and to compare if there is any difference in motivation and ambivalence between women and men. Motivation was measured with eight statements based on previous results and clinical experience.
Genomisk selektion och uppbyggnaden av avelsprogram hos mjölkkor
During the last decade a new technique in animal breeding has developed called genomic selection. It is based on estimations of the effect from genetic markers on traits that are calculated in a reference population. By genotyping individuals, genomic breeding values can then be estimated without phenotypic observations. The aim of this essay is to investigate the response of genomic selection on breeding schemes for dairy cattle. The accuracy of the genomic breeding values is affected by the proportion of observations included in the validation set and how often the equation for estimating breeding values is reevaluated.
Sönderdelning av plogtilta med skärknivar :
During the last couple of years it has been more important to reduce the driving on the field to prepair the soil after ploughing. The machine costs are high so it is necessary to be effective. To reach a pleasant soilbed directly after ploughing is sometimes possible on easier soils but heavier clay soils always need more tillages. There is a lot of equipment mounted on the ploughs on the market, for example Furrow Cracker and Furrow presses, which makes a pleasant soilbed on easier soils. The last year Överum and Kverneland have presented knives which are mounted on the wing or moulboard.
Skogssådd med tall och gran : effekter av fröegenskaper och skärm/hygge på plantbildning, överlevnad och tillväxt de två första åren efter sådd
Over the past few years the Swedish forestry industry has become increasing interested in direct seeding. Although, in practice, this interest has been restricted to pine seed, the knowledge and techniques that have been developed for pine seeding can readily be transferred to spruce. Direct seeding is a method that is of interest to the forestry industry since it can lead to lower regeneration costs, denser stands and better root development than the more conventional planting method.
This study evaluated experiments that focused on direct seeding of spruce in the northern Sweden. Skogforsk set-up the experiments in Gideå and Sävar in 2003.
Fäst vid keramik : En experimentell undersökning av lipidrester i keramik, med GC-MS-metod, efter nedbrytningsförsök
Thisis an experimental study of lipid residues within the field of laboratoryarcheology. Pottery was made in a time like manner and used to cook grain and Icelandmoss and exposed to an organized biodegradation experiment inside an incubatorfor later analyzes with the GC-MS-method. Tests were also taken from pottery,grain and Iceland moss that had not been exposed for a biodegrading attempt.The grain is a domesticated cereal and the Icelandic moss fungi-alga mix. Thetest results showed mostly saturated fatty acids, sterols and monoacylglycerolsof saturated fatty acids. Within the laboratory archeology, ergosterol has beensuggested as a possible biomarker for yeast and alcohol fermentation.
Påverkar tidighetstyp fiberhalten hos rödklöver?
The high feeding value of red clover makes it into an important species in Swedish agriculture. There are three different maturity types grown in Sweden, early, medium late and late. The time for heading, regrowth and winter hardiness is affected by the maturity type, but there can also be other factors that are affected by the maturity type, for instance fiber content. In a greenhouse experiment three red clover varieties of different maturity types were compared; early Titus, middle late SW Nancy and late SW Torun. The features compared were fiber content and differences in development rates.
Effects of shade on milk production in Swedish dairy cows on pasture
Heat stress negatively influences the performance of dairy cattle such as lactation and reproduction. Heat stress can cause production losses as well as welfare problems. Years of research have shown that heat stress is a huge problem for dairy cattle in both the tropics and temperate zones but no such research have so far been done in northern European countries. It seems like shade is an important tool when improving pasture conditions and therefore
deserves more attention. The aim with this study was to investigate whether there is a need of providing shade for grazing dairy cows during the summer in Sweden.
Two groups of lactating Swedish Red dairy cows (n=15 per group) were kept on pasture.
Larynxmask eller endotrachealtub prehospitalt ? styrkor och svagheter : Litteraturstudie
ABSTRACTBackgroundWhen faced with an unexpected cardiac arrest the ambulance nurse is in responsible for taking advanced actions to create a clear airway. Two accepted methods for this is endotracheal intubation and application of laryngeal mask.AimThe purpose of this study was to examine the use of endotracheal intubation compared to application of the laryngeal mask in unexpected cardiac arrest.MethodLiterature study with quantitative approach. A systematic search of 21 articles comparing the laryngeal mask with the endotracheal intubation has been made using Pub-Med and CINAHL. A quality review according to Forsberg and Wengström has been made.ResultsLaryngeal mask had a higher rate of successful applications compared with endotracheal intubation. Time for applying the laryngeal mask was shorter in seven out of ten of the studied articles.
Integrerad arbetsprocess mellan projektör och konstruktör, För effektiv och kvalitetssäker projektering med Tekla Structures och SAP2000
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.
Glycerol till mjölkkor : effekter på våmmetabolismen
Glycerol is essential for the lipid metabolism of both plants and animals. Glycerol is formed in the rumen by hydrolysis of lipids from the feed. Glycerol is also a by-product from the production of biodiesel from rapeseed oil and other fat sources. Glycerol might be used as a dietary glucose precursor for dairy cows in similar ways as propylene glycol. Due to increased production of biodiesel more glycerol has been available to a lower price.
Genes involved in ovulation rate and litter size in sheep
Fertilitetsegenskaper har ofta låga arvbarheter och selektion baserat på fenotyp är ofta ineffektiv och långsam. För att förbättra fertilitetsegenskaper som ovulationsmängd och kullstorlek hos får är det effektivast att selektera avelsdjur utefter deras genotyp. Olika mutationer i gener tillhörande transforming growth factor-? (TGF?) superfamiljen har visat sig påverka ovulationsmängd och kullstorlek hos får. Dessa gener är BMPR-1B, BMP15 och GDF9.
Utsikt för olja : Hur värderas oljeaktier
Background: Oil is the most dominating source of energy of today, it constitutes for more than 40 per cent of the worlds total energy consumption. This together with the fact that stock in oil companies has soared on the stock exchanges around the world makes oil a very interesting topic to write within. In order to gain knowledge in how to value oil companies, the authors will collect information from theory and through a questionnaire. By applying the information gathered to three companies listed on the Stockholm Stock Exchange the authors will reach an objective picture of valuation of oil companies.Purpose: To investigate how shares of stock are valuated in the oil exploring and producing industry, and what specific measures and metrics that are used in the valuation of stocks in Exploring and Producing (E&P) companies.Method: By using a qualitative approach for this thesis, the authors will investigate how the valuation of oil companies works and what measures that should be applied. The authors will use a part descriptive and part explorative study.