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667 Uppsatser om Temperature dependence - Sida 31 av 45
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.
Optimering av OTEC-system
Ocean Thermal Energy Conversion, OTEC, is a sustainable energy conversion technology that is not yet commercialized. OTEC is a technology that utilizes the temperature difference in oceans between the warm surface water and the cold water at 1 000 m depth to run a Rankine Cycle. This technology can produce electricity and provide synergies like fresh water, air conditioning and aquaculture. A simulation program for three alternative OTEC systems has been created in order to decide which OTEC system is most profitable; closed, open or hybrid system. In this simulation a production cost analysis is performed in order to investigate and decide which one of the three systems that has the lowest production cost. The production cost analysis also analyzes if the profitability is affected by the size of the facility. After these analyzes, the most profitable of the three different OTEC-systems is expanded by an installation of solar collectors in order to see if the thermal efficiency is improved. The result shows that the most profitable system varies with the size of the facility.
MEMS baserad referensoscillator
The interest in tiny wireless applications raises the demand for an integrated reference oscillator with the same performance as the macroscopic quartz crystal reference oscillators. The main challenge of the thesis is to prove that it is possible to build a MEMS based oscillator that approaches the accuracy level of existing quartz crystal oscillators. The MEMS resonator samples which Philips provides are measured and an equivalent electrical model is designed for them. This model is used in the simulations of the Pierce oscillator and the transresistance amplifier oscillator that are evaluated in this thesis. Finally the Pierce oscillator is implemented in the A BCD2 process and manufactured at Philips Semiconductors in Nijmegen, The Netherlands.
Att integrera i det svenska samhället : En undersökning om kvinnor med invandrarbakgrund och deras syn på introduktion och andra faktorer som påverkar inträdet i det svenska arbetslivet och samhället
The integration policy in Sweden shall encourage individuals to support themselves and take part in society. It shall alsocontribute to equal rights and opportunities for women as well as for men. In Borlänge this has resulted in a program ofintroduction for new arrivals from other countries. However, at the unit responsible for economic support, they havediscovered that women with immigrant background more often than men seem to have trouble starting or became to anending of the program, which then especially leads women to a long-term dependence for economic support. The purpose of this study has therefore been to investigate what factors affect immigrant women?s participation in theintroduction, and what significance this participation has for their possibilities to become economically self-supporting,and integrated into Swedish society.
Utveckling av processparametrar inom en hårdmetallindustri
This report analyzes and examines a hypothesis for finding a method to optimize thelength of the delubrication process time based on a total charge weight. The work hasfocused on the holding time for delubrication and the total charge weight.An important step in the manufacturing chain of cutting tools is when the greenbodies undergo the sintering process. Today, the delubrication step has the sameprocess time independent of the total charge weight. An implementation of a methodto adjust the delubrication process time would give more consistent quality of thecutting tool´s internal characteristics but also reduce the time course of the sinteringprocess. In the present project two methods for this goal were tested, thedevelopment of an algorithm and a weight interval subdivision with associateddelubrication process times.During delubrication a pressure increase is observed due to the decomposition of thePEG in the powder mixture.
Tubular polyethylene biogas digesters : development and testing of a biogas technology in Malawi to reduce deforestation and support climate change mitigation and adaptation
The aim of the study was to install a biogas system consisting of three tubular polyethylene biogas
digesters at a rural household in Malawi and to evaluate the constructed biogas system with regards
to relevant system parameters. The purpose was to evaluate if the technology is a possible solution
to reduce deforestation and support Malawi in climate change mitigation and adaptation.
The study was carried out in the southern part of Malawi in cooperation with the University of Malawi. Locally available materials were used to construct and install the system. Three different feed materials, cow, goat and a mix of cow and goat manure, were used in order to determine
which one was best suited to utilise as a digester substrate. After the installation, measurements of
temperature, pH, biogas production, biogas composition and system functionality were made.
The results of the study show that a biogas system with tubular polyethylene biogas digesters can be successfully installed at a rural household and that the most suitable feed material is a mix of cow and goat manure.
Provmetod för olje- och partikelöverdrag från kompressor till tryckluftssystem
Compressed air is an energy source that is widely used in today's trucks and buses.Compressor located next to the engine supplies the pneumatic system with the compressed air and is lubricated with the engine oil. Some of the oil follows the air flow in both liquid and solid phase. The solid phase, namely the carbon particles are created due to the high temperature in the compression chamber.Oil- and particles carryover softens and destroys the rubber material in the air valves and disturbs the mechanical function of various components in the pneumatic system. In order to reduce oil- and particles carryover is an Air Processing System (APS) set downstream the compressor.No method for establishment of oil- and particles carryover from the compressor exists at the moment. Therefore the filtration efficiency of APS is currently unknown.
ESC-analys och studering av knack på en "Diesel Dual Fuel"-motor
A one-cylinder research engine has been used for studies with a Diesel Dual Fuel concept (DDF). DDF is a concept that utilizes a pilot diesel injection to ignite a homogenous natural gas/air mixture. Emissions and engine efficiency have been analyzed in an emission cycle called European Stationary Cycle (ESC) and the knock/pre-ignition problems with this type of engine have been investigated.At low and mid torque levels, an early diesel injection around 60 crank angles degrees (CAD) before top dead center (TDC) was used. At these loads raw NOxemissions was below EURO 6 level (0.2 g/kWh). NOxwas at EURO 5 level over the complete ESC without after treatment and with SCR at high loads it should be possible to reach EURO 6.One issue with DDF is the high HC emission levels.
Vanvårdens inverkan på nötkreaturs välfärd och hälsa
Farmers are required to make sure that cattles basic needs are met, but still every year cases of neglect occur where the farmer has not complied within the animal welfare law and regulations. The aim of this study was to investigate how cattle are affected physically and behaviourally by neglect in the form of underfeeding, starvation and lack of sanitation, which animals are most vulnerable to the impact and what prospects they have to recover. The study was conducted as a literature study and the results show that these types of neglect have a large impact on the cattle welfare. Underfeeding and starvation causes physical changes leading to reduced milk production, reduced muscle mass, impaired immune function, poor reproductive performance and changes in rumen microflora leading to decreased number of microbes and pH change. Physical changes due to the lack of sanitation consist of increased vulnerability to hoof diseases and mastitis, burns, and increased sensitivity to temperature.
Tilla?mpning och simulering av naturlig ventilation : Potential fo?r utnyttjande i kontorsrum
Mechanical ventilation is the most common type ofventilation in newly constructed office buildings. Therehas been an interest to utilize natural ventilationinstead of mechanical ventilation among architects andHVAC consultants in recent years. This is due to thesize of mechanical ventilation systems, which arespace consuming. The mechanical ventilation system isalso complex and requires maintenance. Furthermore,the fan uses a considerable amount of energy.
Bogbladssår hos suggor : är höjden på tuber spina scapulae en riskfaktor för utveckling av bogbladssår?
Sow shoulder lesions are a common form of decubital ulcers in sows. The wounds are often bilateral and affect both loose housed and restrained sows. In most cases shoulder lesions develop after farrowing and heal after weaning. Sows that once have had decubital ulcera are however more proned to develop new wounds after the next farrowing. The problem is multifactorial and a number of risk factors have been described, including body condition, body size, parity, time spent lying down, flooring, moisture, breed, body temperature and some herd factors.
The aim of this study was to investigate whether the height of the tuber spina scapulae is a risk factor for the development of decubital ulcers.
Wildlife Detection Network
Traffic accidents where wild animals are involved represents between 60 and 80 percent of all reported accidents, depending on location in Sweden. In a country like Sweden, with a lot of forest, there is always risk of a collision with a wild animal. Imagine if you, as a road user, had the possibility to receive warnings when the risk of an accident according to statistics is extra high.Wildlife Detection Network is a wildlife warning system with an information service, which makes the whole concept unique. When an animal is approaching the road, it is registered by sensors, and warning lights along the road are lit to inform drivers of the potential danger. In conclusion, this is a direct warning to all drivers on the road where the system is placed.When an animal is registered by the sensors, information containing time, date, weather circumstances and coordinates are sent to a database.
Vårdberoende, behov av omvårdnad och insatser för äldre med regelbunden vård och omsorg ? del av SNAC-Blekinge, Vårdsystemdelen
Background: The relationship between advanced age, presence of illness and impaired functioning is well known. A large proportion of the elderly population has an extensive need of care and service and therefore need help from municipal care. Aging is a transition in life and also affects the person's identity and self image, making the person particularly vulnerable and challenging everyday safety. It is therefore of importance to gain knowledge about which factors at individual and organizational level that support a person-centered nursing care for the elderly so that caring responsibilities and staffing of nursing personnel may be scheduled based on need. Aim: This study aimed at describing dependency and care needs of elderly persons living in ordinary housing, sheltered housing and nursing homes.
Hussvamp : Skadeverkan och tänkbar ökning i Kronobergs län
Serpula lacrymans infestation has become an increasingly common problem, and is usually perceived as a tip of an iceberg.During the 21st century there has been a perceived increase of damage caused by serpula lacrymans, at AB Mats Fransson Saneringstjänst ? Anticimex in the county of Kronoberg. A similar increase has also been noted by employees at the offices in Kalmar, Karlstad, Piteå, Stockholm, Malmö, Söderhamn, Halmstad and Visby.The methods used to collect data for the project has been interviews with a number, for the project, relevant key persons, such as analysis engineers at Trygghansa and Anticimex, as well as personnel at the botanical institution at Gothenburg University and the Botaniska Analysgruppen in Gothenburg, further statistics from SMHI and analyses of reported instances of infestations have been used.The majority of the people interviewed believe that the increase is caused by renovations of old houses, higher precipitation during the summer months, as well as a moister climate and warmer winters. The latter can also be gleaned from statistics from SMHI concerning temperature, precipitation, and relative humidity.Analysed damage reports show that the most common cause for the infestation is ground moisture, even when combined wooden materials.Older houses that where built around 1900 are the ones most frequently infested with serpula lacrymans. The part of the building most frequently infested is the foundation, where cellars and suspended foundation are the most common types to be infested.
Självspridning av contortatall (Pinus contorta) på impedimentmark i Sverige
I Sverige finns det ungefär 475 000 hektar skogsmark där den från Kanada introducerade contortatallen (Pinus contorta) utgör mer än 65 % av den totala grundytan. Genom aktiv skogsanläggning har P. contorta blivit Sveriges sjunde vanligaste trädart sett i ett volymmässigt perspektiv. Därför är det av stor vikt att ha god kännedom om hur arten sprider sig i det svenska skogsekosystemet.
När P. contorta introducerades ansågs den sakna förmåga att självsprida sig (fröså sig), men senare visade det sig att andelen serotina kottar varierar mellan olika träd och att den kan självsprida sig på produktiv skogsmark.
Resultatet av studien visar att P.