Sökresultat:
520 Uppsatser om Temperature - Sida 26 av 35
Teknisk undersökning : Rötgaskammare för småskalig biogasproduktion
Biogas mainly consists of methane and carbon dioxide, where methane is theenergy-rich gas, and is naturally created when organic matter breaks down in absenceof oxygen, also known as anaerobic digestion. A biogas plant re-creates the anaerobicconditions inside a digester where the organic substrate is fed into and digests toproduce biogas. The gas is then used to produce energy by combustion and can beseen as a completely renewable fuel.Today, energy from biogas is used primarily by major stakeholders such asmunicipalities and thus the plants become very large with high investment- andconstruction costs. There are currently few small plants in Sweden, even though thepotential for agriculture and medium-sized to smaller farms to become self-sufficientin terms of electricity and heat is great. Farms have a natural stock of digestibleorganic material in form of manure or crops for example, which are constantlyavailable.
Design av försöksanläggning för trycksatt rökgasrening vid oxy-fuelförbränning
Reducing the CO2-pollution, resulting from the combustion of fossil coal for energyproduction, is important to affect environmental changes. One way to achieve a reductionis to use the oxy-fuel technology. The technology uses O2 and re-circulated flue gasduring the combustion which results in a flue gas mainly consisting of CO2. The flue gascould then be compressed and stored without environmental effects. A problem thatfollows from the compression is the risk of acidification in sensitive parts of the process.Acidification can occur because of reactions following from the contact of condensedwater and sulphur- and nitrogen-oxides which are also present in the flue gas.This report compiles and evaluates the basis of a scientific unit with the purpose ofexploring the possibilities of extracting impurities of SOx and NOx from the flue gases.The dimensions of the unit are based on basic conditions, defined for an existing oxy-fuelprocess at Chalmers, and on the results of computer modelling.
Fjällfåglar : En jämförande studie från dal till topp i ett nordligt och sydligt svenskt fjäll
Title: Mountain birds ? a comparative study from valley to mountaintop in a northern and southern Swedish fjeld Author: Kristian Zackrisson Abstract Main aim in this study was to increase the knowledge about birds in the Swedish mountain area. Three questions were asked: 1) Which bird species can be found during the breeding season along a low mountain slope from a forested valley to a mountaintop with bare mountain environment? 2) Do the number of species and individuals differ in different elevation zones? 3) Is the composition of bird species along a low mountain slope the same in the Kebnekaise mountains inLaplandand the Grövelsjön mountains in Dalarna? Bird census in two study sites located in the Kebnekaise mountains and the Grövelsjön mountains and subsequent analysis of the results from the bird census was the main parts in this study. Totally 20 bird species were found along a low mountain slope in the Kebnekaise mountains.
Cleaning process of abattoir wastewater with focus on bacterial pathogens
This study was conducted at the City Abattoir in Kampala, Uganda to evaluate the cleaning process, with focus on bacterial pathogens, in a pilot scale integrated bioprocess. This consisted of four steps: anaerobic sequencing batch reactors; aerobic/anoxic sequencing batch
reactors; a high performance Temperature controlled methanogenesis digester and a constructed wetland. The objective was to determine if this type of cleaning process could be used to clean wastewater from abattoirs in a satisfactory way.
The indicator organisms for faecal contamination, Escherichia coli and Enterococcus spp. were used to investigate in what numbers bacteria could be found in the untreated wastewater and how much that was reduced in the different steps of the cleaning process. The water was
analysed for Salmonella to see if human pathogens could be found and could survive the different steps of the treatment process.
Majs till mogen skörd :
Corn is an important food and feed crop in the world, in Sweden it?s up till now grown
on limited acreages mainly for silage. But I think it can get more important if you can
grow it also for grain, because it?s a good animal feed for example, for life stock-, pigsand
poultry. On of corns advantage is that it can produce the same amount of dry matter
as for example wheat, barley and rise but with 25% less water.
I will examine if it possible to grow corn for grain production in the south of Sweden.
Effektivisering av energianvändningen i en förskola
This rapport contains an examination of the energy consumption of a kindergarten, which areas that have the largest impact on the energy consumption and what can be done to reduce those areas in ways that are relatively easy and profitable. It is also analyzed if it is possible to reduce the energy consumption from today?s consumption to a consumption that fulfils the demands placed on low energy houses by FEBY.The focus has been on reducing the energy consumption of the areas ventilation, heating system and hot water system, since those seemed to be the easiest ones to affect and since the building is quite recently built.There are different kinds of ventilation systems, at the moment the building have a CAV-system, which means that the ventilation is too high during large parts of the day. There are different ways to manage the ventilation system, for example presence detection, humidity sensors, CO2 sensors, Temperature sensors and season adjustment. Many of those are in the end dependent on CO2 sensors to guarantee a good indoor climate, therefore the focus have been placed on this system.
Hur enkel- & dubbelportsturbin i kombination med två olika avgassamlare påverkar gasväxlingsprestanda på en Scania V8
The exhaust arrangement on a Scania V8 consists of one manifold at each bank connected to a twin entry turbine (8-2-2). A study in GT-Power has shown improved performance and reduced cylinder to cylinder variations using two manifolds at each bank in combination with a single entry turbine (8-4-1). This thesis work analyses the difference in performance shown in simulation and verify it by engine test.The initial work was focused on simulation in GT-Power. Investigating how exhaust manifold volume and pulses effects the turbine efficiency and the mean effective pressure during the gas exchange. To verify GT-Power simulations four engine tests with different exhaust arrangement have been made.The results from GT-Power simulation indicate that a larger exhaust volume improve the turbine efficiency.
Styrsystem : För en forskningsutrustning
The division of Engineering Materials at Linköping University, department of Management and Engineering, conducted a research project concerning Fatigue life of thermal barrier coatings during 2009. During this project equipment to provoke these fatigue failure by rapidly heating and cooling test subjects in cycles, was ordered.Design and manufacturing of the equipment was handled internally at LIU.The equipment was built using a furnace that is lowered and raised over the table where the test subject is placed. To keep the Temperature of the furnace a lid slides in place to close the downward facing opening of the furnace when it is in the raised position. On this door there is nozzle that is used to cooling of the test subject by air.To make sure that the equipment can work independently you need an automation controller that can evaluate if movement can occur without danger of collisions. The control system also needs to monitor that all elements are performed according to plan.This degree project is based on a modular system from OPTO 22 and includes the configuration of a PLC that will be supplied with logic and a user interface.The degree project resulted in a graphic interface in which a user can set desired values for different parameters and get information about current values for them.
Foraging behaviour of cattle, sheep and goats on semi-arid pastures in Kenya
ABSTRACTThe principal aim of the study was to compare the feeding behaviour of cattle, sheep and goats on pasture and explain any differences between speices. Furthermore, I compared foraging behaviour between dry season and the beginning of the rainy season, in order to see any relationships between weather and behaviour.The study was carried out in Shompole in southern Kenya. Behavioural data were collected by observing herds of cattle, sheep and goats on pasture. The livestock were herded on pasture during the days and kept in bomas, where people live, during the nights. The weather in Shompole is characterized by high ambient Temperature and low, bimodal rainfall.
Analys av off-design prestanda för ett absorptionskylsystem
This master thesis project at KTH is performed in the Mechanical and Aerospace Engineeringdepartment at University of Florida (UF). The thesis is a small part of a gas turbine researchproject where a vapour absorption refrigeration system (VARS) and a high pressure regenerativeturbine engine (HPRTE) are integrated together. The main objective is to build a computermodel of the VARS. The computer model is supposed to be used to analyse the off-designperformance of the VARS and should also be easy to integrate as a subroutine in a more complexsystem model. To model the VARS some knowledge of the absorbent/refrigerant mixture had tobe well known, in this case a mixture of ammonia and water.
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.
Halvledare för höga strömmar i fordon
Mechanical relays are more and more being replaced with semiconductortechnology. In this thesis it is investigated if and how the larger loads couldbe controlled by transistors. The main part of this work aims to create andverify a solution that can control the starter motor, as well as protect it incase of any failure. The different malfunctions that the solution protectsagainst is high current, too high peak current, low current, maximum cranktime and minimum cool off time. The timers also protect indirectly againstoverheating of the starter engine.The transistors used are BTS555, from Infineon.
Sensory profiling of Swedish white wines and a contextual analysis of Swedish viticulture
The aim of the study is twofold, to generate a sensory profile of Swedish wine today and to investigate the opinion of both wine producers and wine experts on viticulture in Sweden and wine from grapes grown in Sweden, achieved through a contextual analysis comprising a literature study and interviews with wine producers in Sweden and Denmark and wine experts from Sweden and Germany, and a sensory analysis at the company Ipsos. ?Mixed methods? was the chosen research strategy as the semi-structured interviews gave qualitative results and the sensory analysis would give quantitative results displayed as spider charts.
There is a lack of studies investigating how the Swedish wine is perceived by consumers and consumers might be unaware that the Swedish wine, established through ?trial and error?, is increasing in quality every season, creating a need to display the sensory profile of Swedish wine to strengthening the perception of Swedish white wine.
This study shows that the Swedish white wine today is a wine with a fresh, citrusy and flowery aroma and a fresh, citrusy and green apple taste, however, a sensory analysis cannot show if the attributes are those that are desired by the customer, a consumer test is necessary to conclude that. Trends point towards locally produced products, one reason why Swedish wine has great potential, yet the future needs to be secured through job opportunities and education. Creating an approval system for Swedish wine is suggested as a future improvement, it is a common procedure in most wine regions.
Klimatförändringars påverkan på kulturmiljöer i Uppsala stad ur ett geovetenskapligt perspektiv
Cultural heritages are environments created by humans that are considered to have a conservation value for the posterity. They can be seen as one of society's non renewable resources. It is important to have knowledge of how cultural heritages are affected by future climate changes.The water flow in Uppsala is estimated to increase during winter and decrease during spring and summer. Precipitation will gradually increase as well as the intense short period precipitation. The average Temperature is estimated to increase as well.
Glowtest Fixture
The project, Glowtest Fixture, has been carried out to and in collaboration with MSA SordinLtd. MSA Sordin Ltd produces and sells ear protector and is at present a supplier on theworld market. Glowtest Fixture is a product for glow testing off detailed components in oneear protector. MSA Sordin Ltd sends today away your products for testing what is anexpensive aspect in their development. The project's aim is to take forward a test equipmentthat copes with those high nonplussed requirements and wishes that are required for anapproved physical execution.Glowtest Fixture is a physical equipment that comes used stem glow physical off all detailedcomponents in one ear protector.