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 master thesis has been a pilot study preceding a forthcoming project of a larger scale with the long term objective to separate the direct effect of added nitrogen on soil processes from indirect effects via trees. The aim of this study has been to investigate the allocation of nitrogen following direct injection of liquid solutions into the xylem of 40 year old Norway spruce. The field site is located at Flakaliden (64°07?N, 19°27?E), approximately 60 km northwest of Umeå, Sweden. A total of 18 trees were selected for treatment, equally divided between three treatments, potassium nitrate, glutamine and water (control).

The aim of my study is to investigate how last year students in upper secondary schoolunderstand certain mathematical concepts, in particular the unit circle and its trigonometry.I have used intentional analysis to interpret student?s actions when they solve certain tasks onthe basis of a cognitive, situated and cultural context.Interviews with four university teachers in mathematics about the unit circle, trigonometry,and mathematical understanding, serve both as background for the study and as basis for adiscussion, where I relate students understanding to what the teachers want new students toknow about these concepts when they begin university studies in mathematics.The students were arranged in three groups with three students in each group. Each group waspresented with two tasks, one in which they were asked to calculate the cosine values for onepointed, one blunt and one straight angle, each located in a separate triangle. They were alsoasked to decide whether the points (0,71; 0,71) and d (1 2 , 3 2 ) are located on the unit circleor not.My conclusion is that students mainly have an operational conception of the unit circle andtrigonometry. The lack of structural conceptions result in difficulties in seeing connectionsbetween the concepts in unfamiliar situations.

Designmönster inkluderas ofta i utbildningar inom objektorienterad programmering vid högre lärosäten. Det finns dock flera studier som indikerar att det kan vara svårt för nybörjare att förstå hur de ska tillämpas. M. Abdul Jalil och S. A.

AbstractSweden has over the past years grown into a multicultural society which has caused that people with numerous variances of religion and cultures have to interact. This essay will be based on several primary school teacher?s experiences with immigrant families. The purpose of this essay is finding out how they are introduced and integrated in Swedish primary schools by the teachers.I?ve interviewed six primary teachers that shared what they?ve experienced with immigrant families.

The aim of my study is to investigate how last year students in upper secondary schoolunderstand certain mathematical concepts, in particular the unit circle and its trigonometry.I have used intentional analysis to interpret student?s actions when they solve certain tasks onthe basis of a cognitive, situated and cultural context.Interviews with four university teachers in mathematics about the unit circle, trigonometry,and mathematical understanding, serve both as background for the study and as basis for adiscussion, where I relate students understanding to what the teachers want new students toknow about these concepts when they begin university studies in mathematics.The students were arranged in three groups with three students in each group. Each group waspresented with two tasks, one in which they were asked to calculate the cosine values for onepointed, one blunt and one straight angle, each located in a separate triangle. They were alsoasked to decide whether the points (0,71; 0,71) and d (1 2 , 3 2 ) are located on the unit circleor not.My conclusion is that students mainly have an operational conception of the unit circle andtrigonometry. The lack of structural conceptions result in difficulties in seeing connectionsbetween the concepts in unfamiliar situations.

The aim of my study is to investigate how last year students in upper secondary schoolunderstand certain mathematical concepts, in particular the unit circle and its trigonometry.I have used intentional analysis to interpret student?s actions when they solve certain tasks onthe basis of a cognitive, situated and cultural context.Interviews with four university teachers in mathematics about the unit circle, trigonometry,and mathematical understanding, serve both as background for the study and as basis for adiscussion, where I relate students understanding to what the teachers want new students toknow about these concepts when they begin university studies in mathematics.The students were arranged in three groups with three students in each group. Each group waspresented with two tasks, one in which they were asked to calculate the cosine values for onepointed, one blunt and one straight angle, each located in a separate triangle. They were alsoasked to decide whether the points (0,71; 0,71) and d (1 2 , 3 2 ) are located on the unit circleor not.My conclusion is that students mainly have an operational conception of the unit circle andtrigonometry. The lack of structural conceptions result in difficulties in seeing connectionsbetween the concepts in unfamiliar situations.

The aim of my study is to investigate how last year students in upper secondary schoolunderstand certain mathematical concepts, in particular the unit circle and its trigonometry.I have used intentional analysis to interpret student?s actions when they solve certain tasks onthe basis of a cognitive, situated and cultural context.Interviews with four university teachers in mathematics about the unit circle, trigonometry,and mathematical understanding, serve both as background for the study and as basis for adiscussion, where I relate students understanding to what the teachers want new students toknow about these concepts when they begin university studies in mathematics.The students were arranged in three groups with three students in each group. Each group waspresented with two tasks, one in which they were asked to calculate the cosine values for onepointed, one blunt and one straight angle, each located in a separate triangle. They were alsoasked to decide whether the points (0,71; 0,71) and d (1 2 , 3 2 ) are located on the unit circleor not.My conclusion is that students mainly have an operational conception of the unit circle andtrigonometry. The lack of structural conceptions result in difficulties in seeing connectionsbetween the concepts in unfamiliar situations.

The objective of this thesis is to explore the prerequisites for children?s participation in the activities of the public library as expressed by six children?s librarians. Qualitative semi-structured interviews were carried out to investigate how the librarians interpreted the concept of participation and viewed power issues between children and adults. Further, difficulties and possibilities experienced in working with children?s participation and manifestations of children?s participation in everyday library work were also investigated.

SvenskaDetta är en kvalitativ studie som är baserad på semistrukturerade intervjuer. Syftet med detta arbete är att ta reda på hur två matematiklärare och en specialpedagog ser på/beskriver matematik­svårigheter och hur de arbetar med elevernas matematiksvårigheter som de upp­täcker hos sina elever. Jag är väldigt intresserad av att höra vilka matematik­svårigheter och orsaker till matematiksvårigheter lärarna ser hos sina elever samt lära mig hur skolan och lärarna jobbar med dessa svårigheter hos eleverna. Samtliga informanter hade samma svar på mina forskningsfrågor. I resultaten av hela min studie har jag kommit fram till att orsaker till elevernas matematiksvårigheter bland annat är: dåliga baskunskaper, låga baskunskaper förståelse av positionssystem samt begrepp.

SvenskaDetta är en kvalitativ studie som är baserad på semistrukturerade intervjuer. Syftet med detta arbete är att ta reda på hur två matematiklärare och en specialpedagog ser på/beskriver matematik­svårigheter och hur de arbetar med elevernas matematiksvårigheter som de upp­täcker hos sina elever. Jag är väldigt intresserad av att höra vilka matematik­svårigheter och orsaker till matematiksvårigheter lärarna ser hos sina elever samt lära mig hur skolan och lärarna jobbar med dessa svårigheter hos eleverna. Samtliga informanter hade samma svar på mina forskningsfrågor. I resultaten av hela min studie har jag kommit fram till att orsaker till elevernas matematiksvårigheter bland annat är: dåliga baskunskaper, låga baskunskaper förståelse av positionssystem samt begrepp.

Title: What´s the problem? - A study of revenue recognition in IT-consultant     companiesProblem: How do the chosen IT-consultant companies recognize their revenues? What difficulties do the interviewed companies experience in connection with the revenue recognition?Purpose: The purpose of this empirical study is to study how companies in the IT-consultant industry recognize revenues, and to investigate if the companies perceive any difficulties in connection with the revenue recognition. The aim of the study is to give useful advice and guidelines to companies in the IT-consultant business based on the extracted result. Method: The survey took place in Vasteras and started with a preliminary interview with a certified accountant, who had great knowledge of the subject revenue recognition. Then seven companies from the IT-consultant industry were selected, whereof two took part in semi constructed interviews.  Study of the other five companies? ways to recognize revenue was made through their annual reports.   Conclusion: One of the studied companies recognizes their revenues according to the rules in IAS 18, which is because it is listed on the stock exchange.

When the population is getting older, the need for complex care and nursing interventions in elderly care increases. To create a holistic view of the elder and their life situation, interprofessional team collaboration is often desirable and necessary. Teamwork is often described in positive terms, but previous research has shown that this work method is complicated and requires constant reflection and development. The purpose of this study was to investigate how elderly care teamwork is formed in the interaction between representatives of different professionals. To accomplish this purpose, we have studied how the team members define a well-functioning teamwork and difficulties, and how consensus is achieved in the team.

Storm water is defined as runoff from precipitation such as rain or snow. It is collected in sewage disposal systems and since it mainly originates from urban areas it can contain high levels of heavy metals, nutrients and oil etc. Polluted storm water is currently treated by different methods such as wet ponds, constructed wetlands and filter strips. This study investigates these methods, which in earlier studies have shown to give varying results regarding their treatment efficiency.This thesis has been written on commission of SWECO VIAK and was aimed at studying those parameters that may affect the treatment efficiency of nutrients and heavy metals in storm water treatment facilities (STF:s). Through literature studies the dominating treatment processes in ponds and wetlands were examined.

This master thesis was a continuation of a previous study in the diesel exhaust characterization, which is part of the academical work embedded in the EMIR-1 project. The main objective of this thesis work was to finish the installation and make the proper modifications of the particulate mass measuring system located in one of the engine test cells at KTH, in order to be able to measure the mass of the particles from the exhaust of diesel engines.This experiment requires a diluted flow sample from the exhaust that should be sent to the device that makes possible the measurement of particle mass, called TEOM. In the first stage of this project, the objective was to study and make the proper modifications in the existing KTH diluter because there were several problems to obtain a constant dilution ratio from it during tests.This modifications were made and it resulted in a great improvement in the maximum inlet and outlet flow that this diluter can handle. Therefore another modification is proposed for controlling the inlet exhaust flow so it will be possible to regulate the dilution ratio and make it constant along a wide range of engine loads and speeds.The second and most important stage was to make particulate mass measurements possible by analyzing the frequency signal from the TEOM device. The idea was to obtain the frequency of oscillation from the tapered element in the TEOM, and therefore with the proper correlations, be able to predict the particulate mass concentration in the exhaust flow from the engine.An electrical problem in the TEOM circuit was detected and corrected, so the signal that carries the frequency from the TEOM can be analyzed properly.