At nuclear power plants, electrical valve actuators are important for ensuring that the reactor core is water covered and the pressure in the reactor tank and containment is limited. The electrical actuators are provided with overload protection in case of drawing higher current then the motors are rated for. When safety manoeuvres are needed, the overload protection must not trig and cause the valve to stop before completing the manoeuvre. Analyses have showed that the current settings of the overload protection may cause an illegitimate trig at the worst theoretically possible accident. A new method has been developed with conservative assumptions and applies overload protections for all electrical valve actuators at the three reactors in Forsmark..

Efficient energy use in the housing sector is crucial for achieving a sustainable society. The expansion of this sector only represents a fraction of the existing houses, hence it?s within the existing houses the potential for energy savings lie. This potential has been analyzed in order to determine if it?s possible to cut the current energy demand in half.

I have done a follow up study of the restoration of two rivers, Röälven and Grundan, in order to evaluate the effects of the restoration on the endemic population of trout. Both rivers have been used for timber floating during many years throughout the 20th century, and because of this, had all obstacles such as rocks and wood parts removed. In 2004-2005 both rivers were restored, and rocks and wood were put back into the rivers. Spawning grounds were created and boulder dams were constructed to promote the streaming water. The result showed that the trout population of both rivers increased after the restoration, but also that the trout population of Röälven increased more than that of Grundan.

Föryngring av skog är en nödvändig, men kostsam åtgärd och därför är det eftersträvansvärt att hitta en föryngringsmetod som är både kostnadseffektiv och ger en bra föryngring. Ett sätt att få en billigare föryngringsåtgärd är att använda frösådd. Vid en lyckad sådd gör det stora plantuppslaget att plantorna får bra förutsättningar för god kvalitet. Dessa plantor får dessutom bättre rotutveckling och stabilitet än planterade plantor. Användningen av skogssådd är dock begränsad av bl.a.

Denna rapport beskriver en produktutvecklingsprocess som behandlar utvecklandet av ett textilt material som isolerar och skyddar. Det textila materialet ska fungera till ett kylande fodral utan att förstöra dess funktion och behöver därför uppfylla en speciell kravspecifikation. Materialet ska isolera mot kroppsvärme, vara stabilt, skyddande och slitstarkt. Dubbelväv valdes tidigt i arbetet då det är ett enkelt sätt att kunna påverka det textila materialets egenskaper i form av material- och konstruktionsval, i en betydligt större utsträckning än i en enkelsidig väv. För att utveckla ett material med de efterfrågade egenskaperna har tester utförs och den metod som har använts är hypotesprövning.

The aim of this thesis was to answer a number of questions about the environmental consequences of aircraft de-icing. A further aim was to suggest how the environmental consequences due to the release of de-icing fluids can be measured and reduced.The main impact of the aircraft de-icing on the environment is due to the large oxygen demand for the degradation of glycol based de-icing fluids which are released in the environment. The effect of the increase in oxygen demand depends on where the degradation occurs in the ecosystem. In a sensitive ecosystem, the large demand of oxygen could provide an anaerobic environment which would be harmful for many types of organisms.In order to reduce the negative effects of the applied de-icing fluid, there is some type of collection system at every regular airport in Sweden. The methods of collection can be divided into two general groups, hydrological isolation or vacuum sweeper trucks.

Discharge of untreated wastewater leads to unnaturally high levels of nitrogen and phosphorus in rivers, lakes and the sea, which results in unbalanced ecosystems with eutrophication and lack of oxygen. Part of the phosphorus in surface waters is coming from on-site wastewater treatment from scattered households with unsatisfactory purification. Blast furnace slag is a by-product from iron production, and has in laboratory trials showed good phosphorus binding capacity. To test blast furnace slag as a reactive filter media for phosphorus separation in a full scale experiment, a wastewater treatment plant has been built behind the picnic area at Ångersjön alongside the road E4 in central-eastern Sweden. The plant contains two parallel lines, one with blast furnaces slag and the other with Filtralite-P as phosphorus sorbent. Both filters have showed decreasing phosphorus purification effect with time in spite of a low wastewater load.

Vaccination of fish can be assumed to cause pain. This study was designed to see if we can minimize the suffering of fish following vaccination. Fishes are cold-blooded animals and thus more primitive than warm-blooded animals. Despite this, many organs, e.g. the nervous system, have the same basic structure as that of other vertebrates. The fibre system for conducting pain is more diffuse than in humans.

If you have access to wood, a wood burning boiler is a cheap way to heat your home, but it is certainly not the most convenient option. Wood requires many operations and management, which takes time. One way to reduce this workload is to have a modern boiler with automatic ignition. Enertech/CTC has a desire to create an accessory with automatic ignition to a modern wood burning boiler. Today there is no boiler on the market that can ignite firewood automatically without the introduction of paper and sticks.

Every year new premises are built in Sweden, and even if they are made as energy efficient as possible, this will not reduce the energy demands, but the rate of the increase of the energy use will be reduced. One type of facility in Sweden that is a major energy user is public baths, and this makes public baths an interesting facility to study more closely. There are around 500 public baths in Sweden and about 75 % of those can be seen as older baths with large need of renovation, and they all require a high level of energy efficiency measures. To show how the energy demand increase or decrease depending on the changes chosen to be made, the simulation application IDA Indoor Climate and Energy was used. Simulations were made and compared for several cases, with two extreme cases as starting points.

Mankind has always been communicating, it is almost impossible to not communicate. The communication tree has grown a new branch, the environmental communication branch, and an ISO standard, the ISO 14 063 Environmental communication- guidelines and examples was issued October 2006. The purpose of this thesis is commissioned by the managing director of NQA Nordic AB in order to examine and analyse how organisations communicate environmental issues today, and how big the need for ISO 14 063 actually is, and further more if there are needs and wishes to make ISO 14 063 a certifiable standard. The main conclusion is that the there is a need for the standard, but it is difficult to say in which form since the knowledge about the standard is far to low among the organisations examined in this thesis. Clarity and transparency as ISO 14 063 promotes are important ingredients in organisations? environmental work, so sure a standard for environmental communication can help improve environmental performance, for example through opening up for two-way communication and from that on take part of the stakeholders? opinions.This study is based on a literature study and a questionnaire survey where 70 organisations (in this case authorities, corporations and non-governmental organisations) randomly chosen from the seven criteria, which ISO 14 001 defines as the environment: land, water, air, flora, fauna, natural resources and man and his collaboration with those.

Waste appears to be a low-cost fuel compared to biofuel. This Masters thesis was conducted for Vattenfall Utveckling AB and deals with how waste in the fuel affects the performance of a SCR-catalyst. Different mechanisms of deactivation were surveyed, focusing on the poisoning mechanism. A literature study was carried out, which was used as a reference when analysing the results.Small samples (9x2x2 cm, 64 pieces) cut out from a full-scale unused honeycomb catalyst were exposed up to 1500h in two different combustion plants, Johannes in Gävle (co-combustion) and Högdalen in Stockholm (waste-combustion). The activity was measured mainly at 300°C but also at 250, 350, 375 and 400°C.

This report describes a study of two different methods to achive the best possible result in setting out apartment details. These two methods are the setting out of details with a measuring tape from baselines and the setting out procedure with an instrument (totalstation).Through our knowledge in surveying and mapping technology and help from a carpenter, this investigation has been implemented. The setting out using a tape has been performed by letting the carpenter to set out windows, bathroom and water- and drain-details from baselines and drawing. The setting out using a surveying instrument was carried out by means of a Trimble Total Station. These two methods have been compared in order to detect and show the difference that occurs.The report shows the investigation background story from the practice of Swedish Mätcenter in Karlstad.A result of differences in accuracy and time is described in the report, as well as their theoretical consequences.

To turn the dairy heifers out on pasture is the most natural way for the cattle to get feed. At the same time it is cheap and if it is right treated a feed of high nutritive value. The problem today is to get dairy heifers to grow enough when they are grazing at natural pasture for the entire summer. Therefore, the opinions differ whether pasture is a resource or a problem. The increasing interest of pasture production is due to the fact that you can receive grants for preserving valuable natural assets and cultural landscape elements in the pasture land. A high grazing pressure is necessary to preserve an open landscape and a great variety of species. In the same time the heifers have to supply their nutritive needs in order to grow and be large enough to show heat and be pregnant in right time to calve with a sufficient body size and at an economically right age. This paper includes a literature review on natural pasture, pasture production, and growth of dairy heifers together with own interviews with dairy farmers about their point of view to the pasture husbandry on the farms, how they plan for pasture, look after natural pasture, treatment areas and take care of the calves and heifers. The results indicate that the time it takes and the demanded work are the biggest factors to how and why the farmers do as they do..

The building sector accounted for around a fourth of the total energy usage in Sweden in year 2010 (Energimyndigheten, 2012). Therefore it has become very interesting to achieve a lower energy usage in residential buildings. One way to achieve that is to build so called passive houses. By being very well insulated and have low leakage through the walls, they can reduce the energy usage for heating with a substantial amount. The first passive house was built during the 90?s in Germany; and in Sweden the first passive house was built in Gothenburg 2001.