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2844 Uppsatser om Specific surface - Sida 2 av 190

New Generation Surface treatment for tools : A preliminary study

The surface finishing technique called black oxidation is currently being used on thetool holders made of low alloyed tool steel produced by Sandvik Coromant. Blackoxidation isn?t considered a sufficient technique because it doesn?t make the toolholders look like the quality products that they actually are. The reasoning behind thisis that the tool holders can show signs of corrosion after prolonged storing times orin countries with high humidity and temperature. The corrosion doesn?t decrease thetool holders performance, but the customers might believe otherwise.

Vätning på mikroskala

Individual cellulose ?bers were studied to identify the transport and absorbtion phenomena as well as the in?uence of drying. A Chalmers University of Technologydeveloped method within ESEM (Enviromental Scanning Electron Microscope) has been used in this study. The results from the laborations gave the following conclu-sions: The transport of water occurs in ?bers in the ?ber wall surface and the lumen.

Vidhäftning mellan prefabelement och pågjutningsbetong : Undersökning hur skrovligheten påverkar vidhäftningskapaciteten vid skjuvning

Self-compacting concrete has soon been around for a decade. Recently the prefabrication industry has started to use this fairly new concrete type in larger scales, mainly because of its distinctive properties.  There are still certain areas that need to be thoroughly examined, such as bond capacity. There have been very few studies regarding shear capacity due to the fact that the procedure is complicated.This report will highlight a method to examine the shear capacity of different surfaces that have been prewetted as well as non-prewetted surfaces. The surface areas follow BBK 04?s and Eurocode 2?s demand for surface roughness.  A smooth surface will be completed in order to confirm if the different shapes influence the bond strength by shear stress or not.                       The purpose of this essay is to measure the bond strength within the shear capacity as well as examine the impact it has on surface roughness and treatment for shear bond.The method used to identify the shear capacity is called L-shaped Push-Off Test.

Växters förmåga att ackumulera metaller : Vass, bredkaveldun och gäddnate i Bergviks dagvattendamm

AbstractSurface-water includes different kinds of pollutants from traffic and roads. To prevent these pollutants to reach nearby lakes one can construct surface-water ponds on locations with heavy traffic. At Bergviks shopping centre in Karlstad, two ponds, one smaller and one bigger has been constructed in order to decrease the pollutant pressure from the receiving waters of Kattfjorden. Several heavy metals are essential for plants and animals in low concentration but when they occur in higher concentrations, they become toxic to the organism. The larger pond at Bergviks shopping centre has a sedimentation function so the heavy metals sink to the bottom thereby not releasing directly in to Kattfjorden.

Glidytor och ytjämnhet med avseende på friktion och tätning

Gliding and sealing functions in Öhlins shock absorbing systems sets great demands onthe contacting surfaces. In this particular case, the bushings and the sealings on acylinder piston. The surface wanted is a surface with both low frictional forces and smallleakage. This study was done with the goals of investigating and determining existingsurfaces due to the frictional force and leakage. How can we in an easy mannerdescribe these?A number of ten front forks were part of a main study.

BIM vid installationsprojektering

Planet rendering plays an important role in universe visualization and geographic visualization. The recent tools and methods allow better data acquisition, usually with very high resolution. However in computer graphics, there is always the limitation on the resolution of geometry and texture due to numerical imprecision. Not many applications can handle high resolution data effectively.This thesis introduces, Implicit Surface Scene, a level of detail scene management inspired by dynamic coordinate system and SCALEGRAPH? which change over time depending on the current camera position relative to the planet surface.

Ergonomisk och användarvänlig släplift anpassad för skidanläggningarnas och fjällturismens utveckling. : Rapport, examensarbete 2012

Surface lift adapted for today?s user Today?s T-bar lift looks almost the same as when it was launched in 1938, even though a lot has happened in the ski and mountain industries. New equipment has developed without any major adjustment to the lift. Snowboard, sit ski and downhill biking are just some examples of the evolution that demands new seating positions. It?s also very common for families to spend their holidays in the mountains nowadays.

Perkolationsfilter : En undersökning av reningseffekt med avseende på järn och mangan

This master thesis has been done in cooperation with Sweco Viak AB in Sundsvall. The aimwith the project is to investigate the purifying effect of percolation filter due to iron andmanganese. The overall goal was to investigate how the parameters surface load,sandfractions, and burden time affect the purifying effect. The expectation is to optimize thedesign and find a demouldning of the filter that gives sufficient purifying with a highersurface load. As an attempt to accelerate the curing of the filter, experiments with a layer ofsand which surface has been covered with manganese ore (MnO2) on top of the filter havebeen done.As test filters 10 L bars were used and the experimental work was performed at thewaterworks in Hassela and Munkbysjön.In Hassela different sandfractions were tested.

Utveckling av heltäckande gångbord

This thesis work is a 30hp D-level assignment in design as a co-operation between MälardalenUniversity and Scania CV AB in Södertälje. The purpose was to develope a close fitted catwalk.The market has seen an increasing value for these types of applications and have the ambition to keep up with the rest of the competitors. The catwalks of todays standards shall be estetical attractive, have a non slippery surface and be costefficient.While working with this project I have spent a lot of time with the concept proposals and with the evaluation of the concepts, resulting in a final CAD model and a approximation of the cost estimate. The new catwalk fulfils all the new recommendations and rules as sharp edges, ADR, the height of the stepup and a non slippery surface with built in drainage..

Behuggning av betongytor: ett test av hantverksmetoder

During the latter half of the 18th century, when concrete started seeing general use in modern cities, the use of different methods to give the concrete a finished surface texture saw use. One of these was using different methods of mechanically altering the surface using a slew of cutting and crushing techniques with mallet and chisel. This was done in order to hide the often dull and gray look of concrete, and allude to other more expensive and luxurious stones. The work would possibly have been done by experienced stonemasons, using much of the same techniques and tools they would have used while working natural stones. Or did they? This essay explores, through the use of traditional handcrafts and tools, the claim that the working of concrete surfaces can be done with the same tools and skillset as the working of natural stone.

Energieffektivisering i ett reningsverk för skogsindustriellt avloppsvatten genom förfällning av extraktivämnen

Pulp- and papermills expend vast amounts of water in order to produce pulp, paper and cardboard. Hence, they alsocreate vast amounts of waste water which has to be cleaned before it can be released into the receiving body of water. Insuch a wastewater treatment plant, tremendous amounts of energy are expended by the aeration in the biologicalcleaning process. This aeration is necessary to supply the microorganisms that shall decompose organic material withoxygen, which they need for their metabolism. The transfer of oxygen from the gas phase to the liquid phase isprimarily inhibited by surface-active substances in the waste water like resin acids or fatty acids.

Allergifritt boende genom val av invändiga ytmaterial

The number of people of getting allergic symptoms is increasing and the reasons are considered to be many. The human have changed their habits and spend more time indoor. In combination with new building technologies where denser housing constructions and new materials this causes bad indoor climate contributes to a higher occurrence of allergiesThere are several courses of action to deal with this problem. One action is by choosing allergy-free interior surface materials. An allergy-free material emits low concentrations of harmful substances resulting in a great indoor air quality.

Föroreningstransport i grundvatten : En modelljämförelse

This thesis compares different methods for risk assessment of a creosote contaminated site in Vansbro, Dalarna. In a complementary study the importance of using representative data for calibration and validation of stationary groundwater models is discussed. The time dependency between surface water levels and groundwater levels on the site in Vansbro is evaluated by step response analysis. The results show that the groundwater levels reflect only long-term variation in the surface water levels. Hence the use of such long-term means for calibration and validation of the stationary groundwater models is the only theoretically defendable alternative.As a first step in the comparison of risk assessment methods the degree of contamination is evaluated on the basis of generic guideline values for contaminated soils, developed by the Swedish Environmental Protection Agency.

En validitetsstudie på beeptestet : avseende maximal aerob kapacitet för elitishockeyspelare

Introduction: This study aimed to investigate the validity and reliability of the 20m multistage shuttle run test (MST) for elite ice hockey players as a predictor of the maximal aerobic capacity and the how the result is affected by the players age, aerobic and anaerobic capacity, body composition and test surface. The purpose of this was to find out the potential of the 20-m shuttle run test as a measuringtool for the maximal aerobic capacity in frequent testing periods during the season. It is very interesting to be able to administer this easily because the competative phase of the season is very long compared to the pre-seasonal phase and earlier studies have shown that the aerobic capacity is being lowered during this competative phase of the season for elite icehockey players.Methods: 34 elite ice hockey players participated in this study (20.0±3.6 yrs, BMI 24.2±1.6 and VO2-max 58.0±4.8 ml O2?kg-1?min-1). During 3-5 days they underwent 2 MST tests (wood and rubber surface), treadmill running with VO2-max assessed with open-circuit technique, Wingate10% and FFM-assessment with underwater-technique.

VRA-PROGRAMVARA MED TILLHÖRANDE STYRELEKTRONIK

This thesis has been done at the Unversity of Örebro for Örebro University Hospital (USÖ). In our work we have developed a product for hearing tests to determine hearing thresholds of small children. Our product contains software and a control surface for controlling two separate screens. One of the demands was that our software could handle big file libraries. Reliability and simplicity were essential for the user.In our work we have utilized programming of both microcontrollers and Windows software.

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