A titania-supported nickel catalyst was prepared and tested in methanation in order to evaluate its catalytic properties (activity, selectivity and specially, activity loss), and compare it with an alumina-supported nickel catalyst.The titania-supported catalyst did not only show higher stability than alumina, but also presented a different cause of deactivation, carbon formation. In addition, a kinetic model was obtained for the titania-supported catalyst, and a study of the effect of different operating conditions (temperature, composition and partial pressures of synthesis gas and water) on the deactivation rate and carbon formation of this catalyst was performed.

This study aims to seek knowledge about what preschool teachers think about gender issues, and if it affects their work. The study has been performed in a multicultural district in Stockholm. A working party of three teachers, one male and two females, has been interviewed and observed. The empirical material from the interviews and observations has then been analyzed based on theories about gender, femaleness, maleness and cultural behaviour. The result proves that one of the three teachers considers that there are general typical female and male behaviour.

This essay focuses on the technical systems and functions behind how a Roman bath operated. I will present a general view by going through each part of the waters path through the bath one by one. Since there is no such thing as a standardised Roman bath I will, under each headline, present the sub subject with a presentation of the workings and then exemplifying through archaeological findings and ancient literary sources.This essay is therefore meant to present a thorough and clear presentation of the technical aspects of a roman bath. The aim is to give the reader an understanding of how a bathhouse worked in general and why. To this I want to present problems that the Romans were faced with and how they solved them..

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..

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.

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.

The purpose of this essay has been to study if all the districts in the city of Malmoe get to be seen in the city?s biggest newspaper, Sydsvenskan. Is the reporting proportional? What images is the newspaper offering the citizens? Do they match the reality? Or are some parts of Malmoe in the dark, in a media shadow?Research done in the past has shown that Stockholm in many ways is in a media shadow. The same pattern was shown in Gothenburg.

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.

The purpose with this study has been to get a previous knowledge about how pre-school teachers look at the impact of the picture book for children and their language development and participation at the age of three to five years. The study was carried through inquiries at a pre-school in a west Swedish urban district. The study proceed from the sociocultural theory which means that children learn by teamwork with other more experienced individuals. The result shows that the pre-school teachers consciously let the interest of the children guide the choice of books. At the same time they push for the meaning of conversation with the children.

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.

Denna rapport beskriver arbetet med utvecklingen av en ny modell för kaplanturbiner. Utvecklingen bygger på två kopplade differentialekvationer som under arbetets gång anpassats och implementerats i turbinmodellen.Modellen beskriver hur vattenflöde och turbinmoment påverkas av avvikelsen från den optimala kombineringskurvan för vinklarna på turbinens ledskena och löphjul, och är anpassad för ett referensaggregat med tillgängliga provdata. Även övriga enheter i vattenkraftaggregatet modelleras och sätts samman med frekvensregulator och elnät för att simulera aggregatets reglerstabilitet i önätsdrift.Verifieringen av turbinmodellen sker genom försök att återskapa de befintliga verkningsgradskurvorna med hjälp av modellen. Resultatet visar en god följning av de verkliga kurvformerna, dock med något lägre maximal verkningsgrad.Verifieringen av önätmodellen sker genom att prova stabiliteten i nätfrekvens och turbineffekt vid stegpålastningar. Resultatet ger en stabilare reglerstabilitet än i verkligheten, men uppfyller ändå förväntningarna på en fungerande modell.This report describes the development of a new kaplan turbine model.

This thesis provides a good introduction to the American environmental certification system LEED, Leadership in Energy and Environmental Design, and trough compar-isons between Sweden and the United States an explanation to the systems design is given. The work is closely linked to a LEED Core & Shell project in Stockholm, Swe-den, where the goal is to reach the second highest rating in LEED - Gold.This thesis gives a broad description of the LEED system and a more profound study of the energy sector, Energy and Atmosphere. Here, for example, an analysis has been made of how the energy consumption of an imaginary building designed according to the requirements of the BBR (Swedish building code) performs in comparison to the Baseline building in LEED.The existing model of Borgarfjord 3, which served as a case study in this work, has al-so been modified to investigate the energy savings that could have been achieved by adding extra insulation to the building. A description of the problems, regarding how the Swedish district heating system (DES) is treated in LEED, is given as well as the suggested modifications. This is an issue that will be pursued during the process of shaping a new, international, version of LEED due to be launched 2012..

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.