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170 Uppsatser om Particle physics - Sida 10 av 12

Integrerad arbetsprocess mellan projektör och konstruktör, För effektiv och kvalitetssäker projektering med Tekla Structures och SAP2000

The purpose of this work is to design and construct a device able to measure the mechanical attrition of oxygen carrier particles. Those particles are used in chemical looping combustion and in the present situation there is a lack of knowledge in how the attrition process work and in which extension. To find already tested solutions trying to answering this problem a literature study wascarried out and the best solution found was the so called Grace-Davison Jet-Cup method. This method is supposed to emulate the attrition caused by a cyclone separator and its advantages are that it is possible to use small test amounts, 5-10 g, and a thirty minutes long test will be enough to acquire useable results. An device was designed based on the Jet-Cup method with some slight modifications.

Biomass losses during short-term storage of bark and recovered wood

Storage of biomass is associated with problems like heat development, biomasslosses, and reduction of the fuel quality. Certain processes such as biological- andchemical degradation are responsible for these storage problems. This master?sthesis was carried out at Vattenfall Research and Development AB and is alignedtowards quantifying the biomass losses from short-term storage (1-2 months) ofbark and recovered wood. The biomass was stored in outdoor piles during differentseasons, campaign 1 (summer) and campaign 2 (autumn).

MCNP-modell för beräkning av neutrondos och DPA på reaktortanken vid Ringhals 2

In this report an MCNP (Monte Carlo N-Particle) model is described for the reactor vessel at Ringhals 2. The model is validated against the specific activity in neutron dosimeters, extracted in 1977, 1984 and 1994. The validation showed that the calculations of the model are within the requirements of a maximum of 20 percent uncertainty for every neutron dosimeter except one, extracted after the first cycle. The uncertainty of this cycle was mostly due to the operation data rather than to the MCNP model.The model has been used to investigate various questions concerning radiation damage. The reliability of the traditional measure of radiation damage, fast neutron flux (En > 1MeV) has been evaluated.  This has been done by taking the ratio for this and another measure of radiation damage, DPA (Displacement Per Atom), for various positions and layers.

Mätning av Emissioner från en Diesel Motor under Transient Driftförhållande

Transient driftförhållande blir allt mer intressant för forskare och tillverkare och de största svårigheterna är att minska emissionerna utan att påverka bränsleförbrukningen eller motorns respons vid gaspådrag negativt. Huvudmålet med det här examensarbetet var utvärdera olika metoder för att mäta NOx och antal partiklar med hög tidsupplösning för att möjliggöra studier av emissioner under transient driftförhållande.I arbetet har en Horiba MEXA 120NOx NOx-sensor studerats med avseende på linearitet, mätsäkerhet och responstid. Försök för att öka noggrannheten har också gjorts genom att kompensera för varierande skalfaktor för utsignalen och för responstiden.Ett spädsytem har arbetats fram för att ge hög tidsupplösning och god repeterbarhet. I detta ingick en Rotating Disc spädare och en två-stegs Dekati spädare. Spädsystemet var kopplat till en TSI Ultrafine Condensation Particle Counter 3025 A (CPC) och var nödvändigt för att hålla koncentrationen inom det mätbara området.

Hur kan intresse utvecklas för fysik och kemi i grundskolans tidigare år : - En analys av tidigare forskning

I den senaste PISA undersökningen från 2012 testades elevernas kunskaper i matematik, läsning och naturvetenskap hos femtonåringar runt om i landet. Sverige var det land som försämrat sina resultat mest av alla deltagande länder inom samtliga områden. Detta tyder på att något måste göras. Vi har studerat hur man kan väcka intresse för ämnena fysik och kemi inom naturvetenskapen. Detta för att öka de naturvetenskapliga kunskaperna hos eleverna i skolan.

NTA i förskola : En studie i hur förskollärare upplever att arbeta med NTA

AbstractThis study deals with NTA in preschool and the purpose of the study is to find out how the NTA project works out in practice. In the empirical study I have used questionnaires as a research method (Trost2001). Questionnaires have been sent to preschool teachers in the whole of Sweden to get as good a selection as possible. The responses received have been processed and analyzed. The results are reported below.The majority of the teachers thought it worked well to work with the NTA.

Ambulanspersonals uppfattning om fysiska tester och fysisk träning inom ambulanssjukvården

There is no standardized test to control the appropriate physical ability in the Swedish ambulance service. The county in question does not perform annual physical tests. A project has been going to develop science-based physical tests, designed for the ambulance service. The research has resulted in the Aasa-test.Objective: The aims of this study were to examine the ambulance staff perception of the Aasa-test relevance, introduction of annual tests and the importance of their own physical training in relation to ambulance work.Method: A quasi-experimental study with a comparative design has been conducted. Aasa-tests were conducted in 41 randomly selected staff at an ambulance station in central Sweden.

Fisk- och fågelpredations påverkan på den bentiska makroevertebratfaunans sammansättning under tidig vår i Tåkern

Predation is one of many factors that form the structure of the macroinvertebrate community in lakes, wetlands and watercourses. Earlier studies lack an examination concerning how fish- and waterfowl predation affect macroinvertebrates during shorter periods in the spring. I performed an exclosure study in the shallow eutrophic Lake Tåkern which is located in the western part of Östergötland County, Sweden. The experiment was performed during a three week period (1-21 April 2012) when the water temperature was low and the density of migrating diving ducks was high. The experimental cages used included three out of four different treatments; general predation (open cages), bird exclusion (net with mesh size 90*45mm) and no predation (net with mesh size 1*1mm).

Doktorander i fysik söker information : en intervjuundersökning av forskarens första tid som informationssökare

The aim of this Master's thesis is to examine difficulties concerning information acquisition, use, and management experienced by graduate students in physics during their first years of research work. Semi-structured, qualitative interviews were carried out with nine doctoral students. The theoretical background for analysis of the material is based on the work of Patrick Wilson, with particular focus on the concept of cognitive authority, and on that of Lars Seldén, who has proposed the idea of an information seeking career running parallel to the academic career of the researcher. Results from the interviews indicate that most of the students, in the early stages of their information seeking careers, rely to a great extent on supervisors and more experienced colleagues when identifying material needed for the research project. In a situation where information of potential relevance is abundant and where experience and focus are not yet fully developed, senior researchers function as cognitive authorities and as guides to other cognitive authorities.

Paul Tillich och Verkligheten : Är Bibelberättelserna "bara" symboler

In this essay I have aimed to examine how the theology of Paul Tillich relate to modern views of reality, both the way it was expressed in his contemporary time and the way I see it today. Reality I have defined as an entirety of the physic- and metaphysic reality. A so called panentism where God is reality and the world is a part of this reality.With Tillichs Systematic Theology as my principal material, I have first made a brief presentation of his theology, of its construction and main concepts. Then I have chosen to further examine the way he describes being, reason and revelation to see how this particular concepts of Tillich agree with my definition of reality. In this I have consulted the books Tillich in Dialogue by Mackenzie-Brown and Natural Theology Versus Theology of Nature, a book edited after the forth international Tillich symposium 1992, which had "Tillichs thinking as impetus for a discourse among theology, philosophy and natural sciences" as a theme.I have tried to point out the possibilities opened up by the ontology and epistemology of Tillich for the dialogue between theology and natural sciences.

Bilder av fysik : En studie om fysik på gymnasiet

I detta arbete sa? vill jag studera hur praktisk fysikundervisning och bedo?mning i na?grasvenska gymnasieskolor o?verenssta?mmer med modern forskning om fysikpedagogik.Denna forskning spa?nner o?ver ett brett spektrum av metoder och teorier, varav jag harfokuserat pa? om la?rarnas undervisning kan beskrivas som-elevaktiv eller inte,-mer eller mindre baserad pa? bokstudier,-inriktad pa? konceptuell fo?rsta?else eller mer fo?rma?gan att ra?kna specifika uppgifter.Dessa aspekter diskuteras a?ven i relation till de inblandade la?rarnas utbildning.Fo?r att kunna ja?mfo?ra de olika klasserna och la?rarna har jag anva?nt ett test avkonceptuell fo?rsta?else (FCI, se sektion 3.2) samt enka?ter till la?rare och elever. Ur etttyva?rr skevt urval av klasser och la?rare framga?r att det finns stora skillnader pa? hurla?rarna ser pa? undervisningen och vilka undervisningsmetoder de anva?nder, samt hurstyrt de upplever sitt arbete. Korrelationerna mellan elevernas resultat pa? FCI och pa?ordinarie prov pa? motsvarande mekanik a?r sma?, vilket tyder pa? att regulja?ra provma?ter konceptuell fo?rsta?else i liten utstra?ckning.

Hur uppnår vi god inomhusmiljö i förskolan idag?

Abstract:This thesis work has been conducted at the Real Estate Department in Halmstad.The department consists of a construction/project management-unit and an operation/management-unit.Like many other towns in Sweden, Halmstad has had a long lasting problem with indoor environment. Not at least at their preschools.Today they are constructing from current building regulations. They have learned from negative experiences which have occurred in the indoor environment in older buildings.Focus is now on healthy materials, like low emission value, energy efficiency and optimization of the building, but still with soft parameters such as cleaning, interior and choice of materials.The fixtures is provides by the real estate department and the furnishings are provides by the children and youth administration. Together they are trying to provide a great indoor environment.I have, together with the real estate department and the children and youth administration of Halmstad, investigated how to provide a good indoor environment in the preschools with small funds.In my thesis there is one theoretical part with a questionnaire survey of how the preschool staff is experiencing their indoor environment to determine where the problems often start. And a practical part with measurements to try and come down to a result that analysis the cause of the problems and also to make sure that the ventilation systems are fulfilling projected values.The measurements and the questionnaire surveys was made at Lokes preschool in Frösakull, Askens preschool in Oskarström and Gullbrandstorps preschool.There were some differences between the staff-responses at the three different preschools.At Askens preschool they feel that the premises are cleaned poorly.At Gullbrandstorps preschool they feel that the indoor-air is bad because they can´t open the windows.

Analys av turbulensmodeller för CFD

This thesis has been a part of Forsmarks Kraftgrupp AB's evaluation of a turbulencemodel used in simulation of turbulent flow called PRNS (Partially Resolved NumericalSimulation). This model has promising properties and may be of use in savingcomputational resources. The purpose of this thesis was to analyze this model andcompare it with industrially applied models such as k-omega SST and LES (Large EddySimulations).PRNS works as a hybrid of the k-omega SST and DNS (Direct Numerical Simulation)where a constant, RCP (Resolution Control Parameter) with a value between 0 and 1are selected. This constant is then used in the calculations and determines thebehavior of the simulation. When RCP is set to zero the equation are the same as fora DNS simulation and when RCP is set to one the equations for k-omega SST issolved.

Lärande och Utomhuspedagogik i Fysik på högstadiet (Learning and Outdoor Education in Physics at high school)

Skolverket redogör i Läroplan för grundskolan, förskoleklassen och fritidshemmet 2011 för att undervisning i skolan ska innehålla olika arbetsformer och varierande arbetssätt för eleverna att nå samma mål. Ett sätt att variera klassrumsundervisning är genom utomhuspedagogik. Utomhuspedagogik är ett komplement till traditionell undervisning och handlar om att undervisning och lärande sker genom upplevelser i utemiljön. Utomhuspedagogik kräver ett växelspel mellan teori, upplevelse och reflektion. Syftet med denna studie var att utreda huruvida utomhuspedagogik i fysikundervisningen på högstadiet var ett väl motiverat sätt att variera undervisningen, med avseende på hur elever påverkas av utomhuspedagogik utifrån ett såväl lärar- som elevperspektiv. För studien utfördes semistrukturerade intervjuer med två lärare och sex elever från två olika skolor i Skåne.

Individuation : Ontogenes : Prolegomena till Gilbert Simondons genetiska ontologi

The following text constitutes an attempt to present the French philosopher Gilbert Simondon's genetic ontology through an account of his reconfiguration of the problem of individuation in his doctoral thesis from 1958, L'individuation à la lumière des notions de forme, information, potentiel, métastabilité. The intention is to show how Simondon through this reconfiguration of a classical philosophical problem ? in which concepts and schemas from contemporary physics and technology is utilised in a critique of the bi-polar hylomorphic schema as its traditional, substantialistic solution ? becomes able to articulate an anti-substantialistic and anti-reductionistic ontogenesis as first philosophy. A systematic philosophical conception that according to Simondon precedes every critical investigation of the subject as well as every scientific ontology ? not by establishing a pre-critical position, but by exceeding Kant's critical position: that is, through a displacement toward a conception of the transcendental conditions for the genesis of being and thought as real conditions, rather than conditions of mere possibility.

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