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326 Uppsatser om Experiments - Sida 13 av 22

Varför svänger stenen? : En studie i curlingens komplexa tribosystem

The tribo system ice-curling stone was investigated in order to understand the mechanisms behind the stones' behavior on the ice sheet. The problem with non-identical stones should also be addressed.The stone curls, that is, its sliding path deviates from a straight line to the right for a clock-wise rotation and to the left for a anti-clock-wise rotation. Several mechanisms to explain this behavior have been proposed over the years but none has been successful.By carrying out Experiments at the local curling rink and studying silicon castings of ice- and stone-surfaces with scanning electron microscopy and vertical scanning interferometry, it has been decided that the curl is not due to dry friction, ice-debris or the difference in friction on the left and right side of the stone. The side force comes from the fact that the friction is higher at the back of the stone than at the front.The contact between stone and ice is never completely dry, nor in the hydrodynamic lubrication regime. It is probably a combination of hydrodynamic lubrication and a contribution from mechanical scratching of the ice.

En jämförande studie av fluiddynamiken för olika fluidiseringsmedium i en kallmodell av en 100 kW-anläggning för kemcyklisk förbränning

To reduce emissions of carbon dioxide (CO2) Carbon Capture and Storage (CCS) technologieshave been developed. Chemical Looping Combustion (CLC) is a CO2 capture technologywith the CCS framework, and at Chalmers University of Technology in Gothenburg,Sweden, a 100 kW chemical looping combustor has been built.This project aimed to investigate to what degree air can replace helium as the uidizinggas for uid dynamical studies in a CLC cold ow model of the above mentioned 100 kWfacility. Experiments were performed using air and helium separately as uidizing gas andpressure data were obtained, which formed the basis for the comparison. The project alsoaimed to investigate uid dynamics in the uidized bed and study when the risk of sluggingoccuring was greatest. The results were presented in the form of figures and tables dividedinto pressure, concentration and standard deviation of the pressure.The results obtained showed that air as uidizing gas did not create the same uid dynamicsas helium over the entire fuel reactor.

Koncentrisk hämning och stimulans av bakterietillväxt i agarkulturer

The aim of this study is to elucidate factors that effect growth of Sarcina lutea and Bacillus subtilis, exposed to the growth inhibitor SDS (Sodiumdodecylsulfat). Agar diffusion Experiments revealed repeated, concentric zones of inhibition and stimulation upon exposure to Sodiumdodecylsulphate or to Amoxicillin. Temperature, nutrient concentration and inhibitor concentration were controlled. Formation of successively repeated zones of inhibition, stimulation, inhibition and stimulation is discussed: ? The extension of the primary inhibition zone is due to the concentration of applied Sodium dodecyl sulphate.? Immediately outside the primary inhibition zone the bacteria have access to diffusing nutrients that have not been consumed in the primary inhabitation zone.? In zones of dense bacterial growth the bacteria may produce inhibiting substances, affecting growth of bacteria in adjacent zones.? In zones of dense bacterial growth the nutrients will soon become depleted, thus affecting bacteria in adjacent zones..

Sandfångaren : En undersökning av mötet mellan en byggd struktur och ett landskap i förändring

The Sand Catcher                                                       The thesis project The Sand Catcher investigates the encounter between permanent structures and an ever-changing landscape. The migrating sand dune Råbjerg Mile in northern Denmark is 40 meters high and moves more than 15 meters every year. By introducing a solid structure on the site, the fast movement of the sand dune is emphasised and thereby our view of time and space.Through intuitively building models with varied openings and densities I investigated how architectural elements react with sand. From these Experiments a series of spatial features and effects were found, generated from the meeting with the sand.The Sand Catcher is a solid and permanent structure. The sand is the liquid element that generates new spaces, circulations and experiences.

Självgående renslastare till sockerbetor :

Our greatest interest within crop farming is to grow sugarbeets, that?s why we want to write about something new in this sector. We heard that a new concept had come to Sweden so we wanted to find out everything about this machine. This new technique was a self-propelled cleaning loader for sugarbeets. This machine is supposed to replace a loader and a cleaning machine when the sugarbeets is going to be loaded, cleaned and delivered to the sugerbeet factory. The cleaning loader picks up the sugarbeets with rollers from the pile, which is placed close to the road.

Gud, magin och vetenskapen : En analys av August Strindbergs Inferno

This literature review aims to investigate, expose and explain August Strindberg's religious position in his partly autobiographical work Inferno, published in Swedish in 1897, in relation to Peter Berger's socialization theory. Strindberg says in the beginning of Inferno that he goes from being an atheist, occultist and Swedenborgian to finally return to his ancestral religion, Christianity. This is questionable, as Strindberg seems to be religious in its atheistic era, and occultist during his Christian period. Strindberg's own religious views seem not always match what he portrays, compared to what he writes in his correspondence and diary entries. This literature review aims to highlight the influences of Strindberg affected to clarify his religiosity which is implicitly and explicitly depicted in Inferno.

Utdragshållfasthet hos limmade och olimmade gängstänger i limträ

This essay examines pull-out strength of threaded rods fixed into glulam timber. The technology is intended to be used in hidden joints between glulam components. The work began with a study of literature focusing on current research within the topic, mainly to create a base of knowledge before the testing was initiated. Studies of scientific articles reveals a lack of research within this area, which makes it difficult to develop standards and calculation models for these joints. The drill holes in the tests have a diameter of 7 mm.

Hur låter ditt varumärke? En kvantitativ studie om matchande bakgrundsmusik i sällanköpshandeln.

This paper examines the impact of the congruence between the background music and the brand image on the customer behaviour in retail store. The essay's hypotheses are built after the famous S-O-R-model that unveils if congruence background music affects the customers' emotions, brand image and response. The aim of the study is mainly to answer if the congruent background music stimuli in the retail store environment will affect the customer's emotions and if it will increase spent time and money. The congruent background music has been selected through two pre-studies based on consumers' brand image. A quantitative study has been conducted where triangulation was applied in a real store environment, where in total 201 surveys was collected for the main study.

Borrelia burgdorferi : metodutveckling och tillämpning avseende odling och resistensstudier mot komplement, särskilt interaktion med faktor H

The genus Borrelia is a widespread, pathogenic pest and the causative of among others borreliosis or Lyme disease. The vector for the bacteria is the hard tick, Ixodes ricinus and the infection is transferred through a bite. Untreated, Borrelia may cause arthritis, heart damage or neuroborreliosis. Infection is made possible through different strategies for avoiding the body?s complement system.

Ethics and Animal Experimentation in the Laboratory. A Critical Analysis of the Arguments for"Animal Rights"and"Animal Equality"

Growing up as a child, we had a Dog. To us, it was like a means to an end. That is, hunting other animals for food and for protection, with no special care and treatment given to this animal. Butas days passed by I began to witness a wind of change against such actions. I was made to understand that we were committing two crimes-: using the Dog as a means to an end (for hunting and for eating animals).

Renovering av miljonprogrammet till Umeå kommuns nybyggnadskrav för energianvändning

A lot of houses built during the Million Homes Programme are in need of major renovation. Today?s technology and materials are better than in the 60?s and 70?s. Both Swedish government and the European Union have set climate goals regarding energy consumption by 2020 and 2050. Achieving these goals would require better standards in buildings than the Building regulations demands, such as Umeå municipality?s construction requirements for new buildings.The report aims to investigate if a renovation of apartment buildings from the Million Homes Programme can reach Umeå municipality?s construction requirements.

Behandling av lakvatten med kemiska oxidationsmedel för att delvis bryta ned oönskade organiska förening : en studie utförd vid Hovgårdens avfallsanläggning i Uppsala

A renewed application for environmental permit for the Hovgården landfill in Uppsala shall be submitted before December 2004, therefore the municipality of Uppsala needs improved knowledge of the contents, mostly organic compounds in the leachate and they also want to find a method to minimize the emissions of these compounds. The purpose of this study was to find a practical and economical method based on chemical oxidation using oxidants. The oxidants investigated are Fenton's reagent, hydrogen peroxide, Oxypro, potassium permanganate and potassium persulfate. The study was made on untreated leachate and leachate that has been treated in an aerated dam followed by sedimentation dams collected from the Hovgården landfill, and alson on sludge water from sludge storage cells. The effects of the five oxidants have been established by analysing the UV absorbance at the wavelengths 253,7 nm and 260,0 nm at different pH values. The UV absorbance was used to indicate the amount of aromatic hydrocarbons in the water. Also analyses of iron and manganese were done after the Experiments with potassium permanganate, hydrogen peroxide and Fenton's reagent.

Analys av åldersstrukturen hos sik (Coregonus lavaretus) i sjöar utan gädda (Esox lucius)

Development of morphs within European whitefish (Coregonus lavaretus), might be considered as a beginning of a sympatric speciation process. Unpublished data suggests that presence of the keystone piscivore northern pike (Esox lucius) is the main driver of sympatric divergence in European whitefish (Coregonus lavaretus). Using introduced whitefish populations as controlled Experiments, it is possible to determine when different characters diverge in the speciation process. In this study, I analysed age and growth within European whitefish populations of different age to assess if these characters change over time in absence of pike. With using otoliths from whitefish populations of different age, I was possible to determine individual age, and by measuring the length of the fish, growth was calculated.

Brist på själslig insikt? : Utomjordingar och deras forskning kring människan i Dark City

The paper examines how human inner properties and the interpretation of the external worldare explained and presented in Dark City (Alex Proyas, 1998). Aspects as the relationship between the body and soul/consciousness, body snatching, memory transferences and dystopian cities are analyzed. The field of study is compared to a general science-fiction film perspective regarding the aspects. Dark City contains an alien race with a common mind, but who lacks soul and individuality. They represent what humanity can become if the scientific development goes too far.

Observatörer för skattning av verktygspositionen hos en industrirobot : Design, simulering och experimentell verifiering

This thesis approaches the problem of estimating the arm angles of an industrial robot with flexibilities in joints and links. Due to cost-cutting efforts in the industrial robots industry, weaker components and more cost-effective structures have been introduced which in turn has led to problems with flexibilities, nonlinearities and friction. In order to handle these challenging dynamic problems and achieve high accuracy this study introduces state observers to estimate the tool position.The observers use measurements of the motor angles and an accelerometer and the different evaluated observers are based on an Extended Kalman Filter and a deterministic variant. They have been evaluated in Experiments on an industrial robot with two degrees of freedom. The experimental verification shows that the state estimates can be highly accurate for medium frequency motions, ranging from 3-30Hz.

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