Dissertations / Theses on the topic 'OCT investigation'

X-ray fluorescence (XRF) detection of heavy metals is a cost- and time-effective method for investigation of polluted areas. Compared to laboratory analysis, XRF analysis is limited by high detection limits and uncertainties in some situations. Preparation of samples is known to affect the results of measurements.

The purpose of this thesis is to bring a deeper understanding of how different factors affect the results of XRF-analysis. A large number of measurements have been made with the instruments Niton XLt 700 and Niton Xli 700. Results from measurements of lead, zinc and copper have been analysed.

This study has shown that a greater moisture content will give a lower measured concentration for the same sample. If the moisture content is known, it is possible to make good approximations of concentrations in dry samples. No obvious differences were found between different metals.

Proper homogenisation of samples was found to be one of the most critical issues. It should be noted that laboratories do not usually homogenise samples prior to analysis, so samples sent for laboratory verification should therefore be homogenised before sending.

Sample preparation, including drying, sieving to finer grain-sizes and analysing in a special sample cup was found to increase the measured concentrations and decrease the variation between measurements. The concentrations differed with different sample matrices and with sample preparation. Because of the differences, measurements should always be correlated with laboratory analysis before any conclusions can be made. In situations when metals are well within detection range of the XRF instrument, the only preparation needed is in most cases homogenisation. If metal levels are just at the limit, or just below the detection limit, further preparations of samples should be made. When drying samples makes detection possible, more preparation is usually not worth the effort. If detection limits still are a problem after drying, the samples should be sieved and analysed in sample cups. In situations where concentrations still are below the

detection limit when analysing in sample cups, or if the measurements are disturbed for other reasons, another method than XRF-analysis must be used. When XRF analysis is possible, the method is preferable compared to only laboratory analysis. This cost- and time effective method makes a larger number of measurements possible, and gives a more complete overview of a polluted area.

Analys med röntgenfluorescensdetektor (XRF) är en snabb och kostnadseffektiv fältmetod för detektion av tungmetaller i mark. Nackdelen är att mätningarna inte är tillförlitliga i alla sammanhang och att detektionsgränsen för många ämnen är förhållandevis hög. Det är sedan tidigare känt att olika former av provbearbetning påverkar mätresultaten.

I detta examensarbete har undersökts hur olika faktorer påverkar mätresultaten vid analys av jordprover med XRF instrument. Faktorerna som undersökts är inverkan av vattenkvot, kornstorlek, provpåsar och olika provbearbetningsmetoder. Vid provbearbetningsförsöken skickades prover även in till externt laboratorium för jämförande analys. Metaller som undersökts är bly, zink och koppar.

Vid undersökningen konstaterades att en ökad vattenkvot ger upphov till lägre mätvärden. Vid kännedom om vattenkvot kan halt per torrsubstans med god överensstämmelse uppskattas utifrån mätningar på fuktiga prov. Är precisionskraven stora och vattenkvoten varierande och okänd bör dock proverna torkas innan mätningar görs. Ingen avsevärd skillnad sågs mellan de olika metaller som undersöktes.

Vid undersökningen om provbearbetningens betydelse visade det sig att homogeniseringen av proverna är mycket viktig, inte minst av prover som skickas till laboratorieanalys.

Ökad provbearbetning med torkning och siktning till mindre kornstorlek tenderar att ge högre mätvärden med XRF instrument. Storleksmässigt är mätvärden vid obearbetade prov mest överensstämmande med laboratorieanalys. Mest skiljer sig analys på finsiktade prover i provkopp. Korrelationsmässigt finns i en del fall en tendens till bättre överensstämmelse med mer bearbetade prov. Den största vinsten med ökad bearbetning av prover konstaterades i detta arbete vara att mark med lägre metallkoncentrationer då kan analyseras.

I de fall där halterna av metaller ligger väl inom XRF instrumentets detektionsområde visade det sig att det oftast är tillräckligt att endast homogenisera proverna innan analys görs. I de fall där koncentrationen av metaller är på gränsen till vad XRF instrumentet kan detektera rekommenderas att proverna torkas, eller om nödvändigt torkas, siktas och analyseras i provkopp. Där nivåerna av metaller ligger under detektionsgränsen för XRF instrument trots provbearbetning, eller där andra ämnen till exempel järn stör mätningarna, måste en annan analysmetod väljas.

Transfers of joint stock companies can be executed in several ways - for example by transferring individual shares or by transferring all shares or by selling the company's assets and liabilities. It is not fully clear which rules should apply to transfers of joint stock companies. Some legal experts claim that the Sales Act (Köplagen) is applicable, while others claim that the rules for promissory notes (Skuldebrevslagen) should apply. This distinction is of great significance regarding the extent of the vendor's liability. According to Skuldebrevslagen the vendor's liability is rather limited, while Köplagen enjoins the vendor a more extensive liability.A transfer of a joint stock company brings about great economical risks, both for the vendor and for the purchaser. Therefore it has become customary to execute a so-called due diligence, before the actual purchase takes place. The concept of due diligence derives from Anglosaxon law and appears in Sweden since the 1990's. The purchaser is allowed to examine the company before the purchase. Normally the purchaser engages expertise to do the actual investigation, for example a law firm. An interesting question is to what extent the actual examiner (i.e. the lawyer) can be considered liable.

The purpose with this study was to examine six caseworkers and two clients’ experiences of interaction in the investigative work of social assistance. Moreover, how the interaction between caseworkers and clients are affected by the structure of the social assistance unit. The study also wanted to show how interaction rituals contribute to the change in assessment procedure in the investigative work. The study even aimed to highlight the ways in which social exclusion occurs in investigative work from caseworkers and client’s capital and gender. Finally, the study intended to look at how caseworkers and client’s positions as superior and subordinate affect the interaction of the investigative work and what roles are shaped during their meeting and how the roles form the interaction. The questions were examined using qualitative methodology in the form of semi-structured interviews. I´ve based the paper on social exclusion processes and applied organizational sociology. The theoretical perspectives used in this thesis work is moreover Ahrne’s organization theory, Collins’s theory of interaction rituals, Goffman’s role theory, Bourdieus’ theory of distinction and capital concept and Mulinari and de los Reyes intersectionality concept. Main conclusions I could draw from the survey results and analysis are that the caseworkers and clients’ experiences tend to resemble each other in many aspects. Overall the caseworkers and clients experience that the interaction is multidimensional; however, the interaction is founded in the authority structure. The interaction is represented by the caseworker’s dominant position, where their overall superior role exists in which the underlying dual roles as helpers and personal authorities also occur. Unlike the caseworkers the clients hold a dominated position, where their overall subordinate role exists in which the underlying dual roles as clients and as individuals occur. This means that the interaction is primarily governed by the caseworkers and client’s freedom of movement is restricted. Clients welfare and their meaningfulness of everyday life including their financial situation are thereby affected by the interaction of the investigative work as a result of the interaction leading toward that the client is justified social assistance or not.

This study is about how social workers use knowledge in their investigation work. The study includes 16 social workers documentation of their knowledge use in 21 investigations in three personal social services in Västerbotten, Sweden. The three research-questions that the study aims to answer are: what knowledge do they use, how do they use their knowledge and on what grounds do they choose these knowledge’s?

The studies empirical findings are a result of a systematic documentation instrument SPP (Systematic Planned Practice). The instrument consists of seven different forms that together correspond to the whole investigation process, from the first meeting with the client to a complete investigation. The SPP-instrument was designed by Professor Aaron Rosen from Washington University in St. Louis, USA. The SPP-instrument was used in this study as tool to gather information on what knowledge social workers use in the investigation work. The seven forms that the instrument consists of were sent to the social workers electronically. In each step of the investigation work the social workers filled out each form and send them back to the researcher for analyse.

The results from the study shows that social workers use a variety of different types of knowledge as a base for their decisions in the investigation work. In the majority of these knowledge’s the social workers relates them to actual client situations. When the social workers describe how they use their knowledge the result shows that they use different strategies to express their use of knowledge in relation to specific decisions in the investigation work. How they use these knowledge’s seams not to correspond with what kind of knowledge they have used. The social workers claims that their choice of knowledge as roughly has to do with two different set of circumstances: 1) circumstances that limits their choice of knowledge and 2) circumstances that they intellectual know that they can influence ones they reflect upon their choices, but not during the actual choice of knowledge.

All together the study shows that the social workers use of knowledge is partly a hidden process that they have trouble to express in writing. However this do not mean that they are short of relevant knowledge for their profession. Instead it shows that social workers use of knowledge is highly situational and that their use of knowledge is a cognitive process that is difficult to describe or conceptualise.

The road traffic density is continuously increasing. By the intensive use of automobiles, it comes

to considerable difficulties and unpredictable events. The frequency of traffic obstructions, traffic

jams and accidents will also increase in future. A solution for this problem would be that

the driver would be supplied information when he is on the road. The information should be

including about road and traffic conditions and also information about other vehicles, which in

the near vicinity.

This kind of information sharing between vehicles is called C2C communication.Especially in

Europe there are many projects which are working for different C2C communcation applications,

like.

Objective of this thesis is based on former works, which optimized the antenna positions

for C2C communication by ray tracing simulation. The investigation of antennas for the C2C

communication, two different approches are taken in to account, a narrow band, and broad band.

Investigation of transparent material for broad band is also the part of this thesis.

Med den här uppsatsen vill jag belysa estetikämnenas roll och status i två grundskolor i en medelstor västsvensk stad. Jag vill även se i vilken mån de estetiska arbetsformerna praktiseras i skolornas vardag och i vilken mån lärarna anser sig ha nytta av styrdokumenten i detta arbete. För det här syftet har min metod blivit en enkätundersökning där pedagoger från de båda skolorna har fått besvara frågor kopplade till följande fyra estetiska arbetsformer: bild och form, drama, musik och dans. Resultaten redovisas utifrån tre kategorier: skola, ålder och yrkesgrupp. Vad som bland annat framkommit i undersökningen är att bilden är den arbetsform som tar upp mest tid och dansen den arbetsform som tar upp minst tid. Vidare ser man att skolorna planerar och förbereder estetiska arbetsformer mindre än 30 minuter i veckan eller inte alls samt undervisar generellt sett mindre än 60 minuter i veckan i dessa arbetsformer. Dessutom framgår det att pedagogerna anser sig ha endast viss eller mycket liten nytta av central och lokala styrdokument när de skall planera lektioner inom de estetiska arbetsformerna.

The aim of this composition is to enlighten the role and status of the artistic work forms in two compulsory schools in an average town in the western part of Sweden. I would also like to see to what degree the artistic work forms practises in the average school day. For this object, my method has become a questionnaire investigation where the educating staff from each school has answered questions connected to these four artistic work forms; art, drama, music and dance. The results is presented thru three categories; School, age and work category. A part that has been presented from the investigation is that the art form is the one that takes up most of the time and dance the one that takes least of the time. Furthermore can one see that the schools plans and prepare less then 30 minutes a week or no time at all and educate generally seen less then 60 minutes a week in artistic work forms. It also shows that the educators only have some or little use of the steering documents when they plan the lessons within the artistic work forms.