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433 Uppsatser om Particle-emissions - Sida 3 av 29
Manure evaluation in dairy cows :
Manure evaluation has been suggested as a cheap, fast and easy method which can give information about the digestibility of the ration, the function of the rumen, where in the gastrointestinal tract the feed is digested and the health of the cow.
An experiment was conducted to study how manure evaluation could be used as a management tool in Swedish Dairy farming. Manure was collected from cows on Kungsängen Research Station and from 9 other farms. The manure samples were analysed for dry matter, ash, starch, pH-value and particle size (wet sieved). Also, the consistency of the manure was determined on a 5-point scale and the colour and smell were noticed. Penn State Forage Particle Separator was used for determining the particle size of the roughage.
Effect of plant maturity at harvest of haylage on digestibility and faecal particle size in horses fed forage-dominated diets
Time of harvest affects nutritional value and digestibility of haylage since plants are in different developmental stages. The aim of this study was to examine the effect of plant maturity of haylage cut in June, July and August on digestibility and faecal particle size in horses.Forage and faecal samples used for the analysis of apparent dry matter digestibility (DMd) and particle size distribution in faeces were from a feed-study performed in the autumn of 2009. Twelve horses were used in the study, divided into three groups in a change-over experiment. Each group was fed haylage harvested in June, July or August during three periods. Faecal grab samples were taken from each horse and pooled so that one sample represented one horse during one period.
GPU accelerated SPH simulation of fluids for VFX
Fluids are important to the Visual Effects Industry but extremely hard to control and simulate because of the complexity of the governing equations. Fluid solvers can be divided into two categories, those of the Eulerian point of reference and those of the Lagrangian. Both categories have different advantages and weaknesses and hybrid methods are popular. This thesis examines Smoothed Particle Hydrodynamics, a Lagrangian method for physically based uid simulations. To allow the artist the exibility given by shorter simulation times and increased number of iterations, the performance of the solver is key.
Majsensilage - partikelstorleksfördelning och hygienisk kvalité :
Fieldstudys on 22 farms (23 silos) to study relationships
between the actual particle size of the maize silage and the theoretical length of cut. The measure of theoretical length of cut were stated by the farmers and not measured by us.
Particle size of maize silage was determined using the New Penn State Forage Particle
Separator. SLU Skara made a special sieve for us, that had larger holes than de original
sieves. The samples were shaken after instructions and then the
material was weighted. We have also been taking out samples for microbiological
analyses from the silos on 13 of the farms.
Ammoniakförluster vid flytgödselhantering : myllning och surgörning som metoder för att minska avgång vid spridning
The ammonia emissions are an environmental issue since they contribute to eutrophication. By far the largest source of ammonia emissions is manure from agriculture and should therefore be reduced. Loss of ammonia is not only negative for the environment but also to the farmer who loses nitrogen that could have been used by the crop.
The focus of this study has been emissions from spreading slurry where the loss can vary widely
depending on slurry-, soil-, and weather conditions.
There are mainly two different ways to reduce the emissions. One is to inject or mix the slurry into the ground to avoid air contact. The other way is to use acid to reduce the pH in the slurry to a level between 5 and 6 where the equilibrium is so strongly pushed to NH4+ that hardly any NH3 can be lost.
Fordonsgas ur gödsel och vall
AbstractThe dependency of fossil fuels in the transport sector causes large emissions of carbondioxide. This problem can we reduce by using vehicle gas from digested solid manure and leftover of pasture. I have studied the potential for this in the county of Västernorrland. Thepurpose is to investigate how much vehicle gas that can be extracted.One central, large scale digestion and upgrade plant should be placed in Härnösand. Theamount of pasture and manure that is economical and practical available is enough to produce2,7-3,5 millions Nm3 vehicle gas.
Spridning av släckvattenpartiklar : En studie på spridning av partiklar genererade från brand
During a fire large amounts of particles and unhealthy agents occur. Polyaromatic hydrocarbons (PAH) and toxic metals are examples among many others. These agents have a capacity to bond to particles and when the fire is extinguished, the particles can be transferred with the extinguish water into the soil and to the groundwater.Recent studies in particles have been conducted. A study by Ulrika Iverfelt (2014) reviled that the particles from a fire contained large amounts of both PAH and metals, which is consistent with earlier analyses. Her column experiments with particles in the size ? 11 microns and ?100 microns in silica sand, reviled that the larger particles was immobilized because the transportation was influenced by sieving or physiochemical particle and surface interactions.The transport of the particles in soil and groundwater is regulated by two main mechanisms: physiochemical surface interactions and straining.
VVA-strategier för avgastemperaturhöjning på en HD-Dieselmotor
Regulations on the exhaust emissions of HD-diesel engines are becoming more and more stringent, and therefore, emission after-treatment systems are commonly used. These systems rely on catalytic conversion of NOx,CO , and HC emissions, and are thus dependant on temperature. At low load of the engine, exhaust temperatures are not sufficient for the after-treatment components. Therefore, means to increase the exhaust temperature while maintaining low emissions and fuel consumption are needed.The focus of this project has been to develop strategies for the lift profiles of exhaust and intake valves in the engine, with the goal to raise exhaust temperature in combination with low emissions and fuel consumption. The strategies have been tested in a single-cylinder research engine equipped with a hydraulic variable valve actuation system.
Bostadssektorns koldioxidutsläpp
Energy is an important issue in the current world which significantly affects sustainability and development. Energy generation and use are major sources of CO2 emissions which is one of the most important driving factors in global climate changes. The amount of energy used in house hold section can lead to estimation of the amount of CO2 emitted within this section which subsequently would be a ground to better management and maintaining a sustainable society. This study which is a bachelor?s project in sustainable energy, deals with estimation of CO2 emission from different types of residential houses in Sweden. An extensive literature review on energy use in Sweden by different residential sectors has been conducted.
Stubblyftningens initiala effekt på emissioner av växthusgaser från en granmark i Småland :
In order to reduce greenhouse gas emissions from human activities fossil fuels will have to be replaced with renewable energy alternatives, such as bioenergy. Sweden has a great potential to produce bioenergy derived from forest products and there is currently a great interest within Sweden in using stumps for bioenergy production. However, the environmental consequences of the method need to be investigated before stump removal can be performed on a large scale. Swedish forest soils contain large carbon pools and a different land use may change conditions so that soils that presently act as sinks of carbon could potentially turn into sources of carbon release instead.
This study investigates the initial effects of stump harvesting on the emissions of three greenhouse gases, carbon dioxide, methane and nitrous oxide. The emissions were measured from the soil surface in a Norway spruce forest located in the southern part of Sweden.
Luftutsläpp från järnmalmsproduktion : - Strategier för systematisk luftkvalitetsmätning
The mining company LKAB extracts iron ore in three areas in the north of Sweden, Kiruna, Malmberget and Svappavaara. The iron ore is refined and in the pelletizing plants the material is rolled to finished pellet product. The different steps of pelletizing plants causes among other things emissions to the air. It occurs occasionally stops in the production and the emissions are vented via an emergency chimney without purification. The aim for this work is to look into how LKAB may improve their monitoring of air emissions and control of ambient air quality and the analysis methods which are suitable for measuring.
Brännkammare för träpulver : Teoretisk analys och praktisk försök
The thesis describes a completely new biofuel system to generate particle-free heat from combustion of ash-containing biofuel particles at high temperatures.The suggested system gives opportunities to introduce biofuels in new areas.Main components in the suggested system is a heat radiating combustion chamber intended for pulverized wood, combined with regenerators to extract heat from flue gases and simultaneously preheating the combustion air.The thesis contains a description of the suggested system, theoretical considerations, calculations regarding the combustion, and includes results from tests performed.The results from calculations and tests performed concludes that the system is workable and possible to apply..
Påverkas miljökuznetskurvan olika av ekonomisk frihet än av demokrati
According to the theory of environmental Kuznets curve there is a relationship between carbon emissions and GDP. The relationship has an inverted U-shape. Carbon emissions rise initially and then decreases once a certain level of GDP is obtained.This essay interprets earlier studies in the field of environmental economics and uses public choice to seek answer on how the population acts on aggregate level. This essay analyses 115 countries in cross-sectional data. The analysis shows that there is a significant relationship between carbon dioxide emissions and GDP that is increasing at first and then decreases for a certain level of GDP.
Konsumtionens klimatpåverkan : En jämförande studie mellan två socioekonomiskt skilda bostadsområden, Araby och Söder i Växjö
The world is in a stage of climate crisis where the average temperature is rising, with consequences such as, melting ice sheets, increasing sea levels, and floods. The climate panel of the UN, IPCC, has stated that this is a reaction of anthropogenic emissions of greenhouse gases. The most important gas is carbon dioxide, which contributes with 80 per cent to the on going climate crisis.The increasing emissions of carbon dioxide are connected to human consumption patterns. This puts pressure on the earth, as humans demand more and more resources. Today the earth needs one and a half year to regenerate the resources humans? demand of it, by the year 2030 we will need two planets in order to cope with this increasing demand of resources.At a global level it is established that richer countries have a stronger consumption pattern than poorer, and thus generate higher levels of carbon dioxide emissions.
Storage stability in a milk based UHT-beverage : effect of pH, carrageenan and storage time
The different characteristics of many food products, such as aroma and texture, changes during storage time and become undesirable. The reason is instabilities within the product which become prominent as the product ages. These changes in characteristics are quality losses caused by changes in the product?s intrinsic and extrinsic environment. The stability in UHT-milk and beverages similar to it have been studied in the past decades and a certain focus have been on age gelation which is a common
defect in these type of products.