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3796 Uppsatser om Nyckelord: Mixing-layer - Sida 1 av 254

Strömningen i och över en skog : utvärdering av en 'mixing-layer' hypotes

A new theory for predicting the windprofile over a canopy has been evaluated. The theory was first presented by Harman and Finnigan (2007). The theory relies on the forming of a mixing-layer above the canopy, due to different mean wind in and above the canopy. Characteristics from both mixing-layer and Monin Obukhov similarity theory have been used to develop the governingequations that give the wind profile. The theory has been used to calculate wind profiles for sixdifferent atmospheric stabilities.

Utvärdering av jetomrörning : En studie gällande utvärdering av omrörningssystem vid Ekeby reningsverk

Biogas is a renewable energy produced through anaerobic digestion, which means that organic matter is degraded by microorganisms under anaerobic conditions. The produced biogas can then be used for cogeneration, electricity, heat or upgraded to vehicle gas. Eskilstuna Energy & Environment AB has four digesters at Ekeby water sewage treatment plant, Eskilstuna. One of the biogas reactor (RK4) is equipped with a jet-mixing system while the remaining digester uses top-mixing. The mixing system is an important parameter to achieve optimum operating conditions for the process regarding gas production and degree of digestion.

Hur inverkar kontrollbordet på frekvenskurvan vid lyssningsposition i kontrollrummet när placeringar av högtalaren och lyssningsposition placerats efter ITU-R BS.1116-1 rekommendation?

The acoustics in a control room is a complicated phenomenon. Early reflections, reverberation time and area in the room are some of the problems. This report is about the reflection on the mixing console in a control room. The control room being built, these reflections are difficult to take into consideration since the mixing console is one of the very last items you place in the room. This report will explain three main measurements that were done in order to get the answer to the following question: Does the mixing console interfere the frequency curve at listening position? Three measurements were done and the difference between the measurements was that the microphone and the loudspeakers were placed in different places in the control room.

"BÄTTRE BALANS I BOENDESAMMANSÄTTNINGEN" - FÖR VEM? : En studie om boendes upplevelser av social mixing i tre bostadsområden i Köpenhamn

Social mixing går ut på att ?mixa? befolkning av olika klasser i ett bostadsområde med syfte att förändra områdets sociala sammansättning. Syftet med uppsatsen är att undersöka social mixing som urban utvecklingsstrategi i Köpenhamn utifrån boendes egna upplevelser av sina bostadsområden. I Danmark definieras 29 bostadsområden som ?ghetton? utifrån kriterier rörande de boendes anknytning till arbetsmarknaden, ?icke-västliga? härkomst samt kriminalitet.

Askdeponi i bergrum : Metoder för slurrytillverkning

This thesis work has been carried out at the consultant company Pöyry Sweden AB in Norrköping, whom performs the task for E.ON heating Sweden AB, Händelöverket in Norrköping. The report shows methods to manufacture slurry consisting of fly ash and water. The slurry shall be pumped into several former oil storage rock shelters that E.ON has put into operation for the specific purpose. The ash mixture also develops hydrogen gas in contact with water.The work has aimed to produce different suggestions of methods and equipment that can be used for the objective. Mixing method and security issues were in centre while working with the suggestions.

A Cross-Country Skiwear Collection for Beautiful Women

This thesis deals with cross-country ski clothing for non-competitive women. Women in this category look for different clothing features in comfort and aesthetics than male top athletes, for whom cross-country skiwear today often seems to be designed. In this thesis the demands of these women have been mapped out by an interview with a reference group of users. The ergonomics of exercising in the winter outdoors are naturally a base for the collection. The collection consists of three functional layers of garments.

Klimatsimulering av ett kontorsrum : Hur de termiska stigkrafterna påverkar ventilationseffektiviteten

AbstractIn urban societies people spend more and more time indoors, which put great demands on the indoor environment. If the ventilation is to manage the removal of unwanted substances in the indoor air, a good mixing of the air is required. The question arises that, whether the buoyancy forces will counteract a good mixing of the indoor air or not?This report aims to clear up the difficulties whether you need to consider the buoyancy forces or not, when adjusting a ventilation unit. For studying the indoor mixing of the air a two dimensional model is constructed in COMSOL Multiphysics.

Möjlig kvittblivning och eftermarknad av ridbaneunderlag - topplager

The aim of this study is to find information about what to do when riding arena footings are worn-out. Especially, the surface layer of riding arena footings is very interesting because of its importance of giving grip in every step for the horse, as well as shock ab-sorption. Generally, surface layers are containing several different parts in order to achieve desirable properties. These different parts can consist of organic material or in-organic material (mostly gravel). Gravel and many other materials in the top-layer are environmental friendly, and therefore, easy to get rid of.

Tidsåtgång i system med självgående/självlastande fullfoderblandare :

In this study I have compared two systems of handling TMR, self-propelled/ self loading mixers and conventional towed mixers, what has been investigated is the time for filling, mixing and feeding TMR as well as maintenance and fuel consumption. The background of this study is the structural rationalization within the Swedish milk production that has put focus on efficiency and reducing of costs. Forage and labour are the two biggest costs in milk production today. The study has been performed by visiting three farms and with a stopwatch measured the times for filling, mixing and feeding TMR. At the time for the visits, the users have been interviewed regarding maintenance and fuel consumption. They have also had an opportunity to give comments of how they experience the mixers. The result of the study after processing is that the average stock in the study can save 74000 SEK a year by reducing time for filling, mixing and feeding TMR to cows with a self propelled/ self loading mixer . The conclusion I can make of this study is that it?s not the size of the stock that decides whether it?s interesting to invest in a self propelled/ self loading mixer, but the presumptions on the farms, for instance forage logistics and mechanical equipment..

Modellering och simulering av hydraulik för användning i hardware-in-the-loop

Modeling and simulation is growing ever more important in the development of new products. This thesis describes the use of Hopsan for hydraulic modeling and its use in conjunction with Simulink with the intent of using the model in a hardware-in-the-loop setup. A sensor layer has been created in Simulink to emulate all the internal sensors in a modern forklift. The details of using legacy C-code instead of a hardware MCU for a fully simulated environment, software-in-the-loop has been outlined. There are two major routes one can follow implementing software-in-the-loop, exporting the C-functions to CAPL via a export layer or creating an s-function in Simulink.

Fällning av kisel från avloppsvatten vid Hellisheidarvirkjun - experimentell studie

This report is about the experiments with mixing of the separated water and the vacuum pump seal water at Hellisheiði power plant. This is done to prevent silica scaling and clogging in pipes and reinjection wells as well as eliminating vacuum pump seal water from the plant. The experiments were done in four stages: the first stage comprised of tests with different flows of separated water at 70°C, the second stage was carried out by mixing the separated water at 70°C and the seal water with different amounts of the seal water, the third and the fourth stages were like the first and second but with the separated water at 120°C. The results show that this method is good if the mixture is around 50/50 separated water and seal water, to control the silica scaling in the separated water and to be able to reinject the seal water with the separated water. This does not eliminate the silica scaling in all of the separated water because the amount of separated water is much more than the amount of seal water that comes from the plant. .

Nedfästning av oljemåleri på puts.En fallstudie från salongen på Mostorps slott i Halland

This thesis, designed as a case study, is about complications concerning conservation of a decorative oil paint on lime plaster from the drawing-room in Mostorp castle sited in the county of Halland in south-west of Sweden. The building was built 1878-80 with an exterior of granite. The interior walls were made of clay bricks, lime mortar and lime plaster. The oil paint is applied to a layer of putty. The combination of different materials, which are organic and inorganic, affects the movement caused by internal and external stress.

Energieffektiv design av ett inbyggt flashminneshanteringssystem

The report is the result of a master thesis at ENEA AB during the fall of 2009. Itaims to create a specification of flash memory management system which focuseson power efficiency and low RAM usage for embedded systems, and to design andimplement a prototype of such a system to facilitate further development toward thecreated specification. The system used by ENEA today is a Flash Translation Layer(FTL). It has a complex structure which prohibits modifications and customization,therefore a new flash memory management system needs to be developed.The suggested solution uses a translation layer called Metadata FTL (MFTL), wherefile system metadata and userdata are separated from each other in order to improveperformance. The partition holding userdata uses a block-level mapped translationlayer system called Fully Associative Sector Translation FTL.

Geokemin inom osorterade cirklar : Analys av tungmetallers distribution inom jordprofiler tagna från Abiskoområdet, nordvästra Sverige

The Arctic region appears as a pristine remote environment, yet there is increasing evidence that it is greatly impacted by pollution such as lead (Pb) and mercury (Hg). In this environment deposition of Hg has increased threefold since the last industrial revolution. In this study five cryosolic soil profiles within non-sorted circles (NSC) in the Abisko region, northwest of Sweden, has been analyzed to improve our understanding regarding how pollutants are distributed within such type of soil. The soil samples have been analyzed with the use of X-ray fluorescence analysis (XRF), for the measurements of the total concentrations of e.g. lead (Pb) and zirconium (Zr).

Betydelsen av hästens hud och päls för reglering av kroppstemperatur i kyla ? vad händer vid klippning och täckning?

The horse is a homeothermic animal and to keep a constant body temperature in winter season is important. Acclimatisation is to provide means for a good thermal insulation consisting of skin, hair, and an outer air layer. The skin covers the horses body and it is composed of three main layers where the top layer of the epidermis consists of dead keratinized cells that are constantly being sheed. The dermis is composed of collagen connective tissue that give the skin its strength. The bottom layer with subcutaneous fat provides a thermal insulation and can be used as an energy reserve in cold weather.

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