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1616 Uppsatser om Surface water - Sida 41 av 108

Cone. En armatur som bärs upp av sin egen ljuskägla.

Inspired by how to sketch a light cone from a flashlight in a comic I wanted to create an armature carried only by its own light cone. To manage this challenge I sketched in an architectural and sculptural way, where I chose to ignore the function of the lamp as long as possible.As a result I developed an armature with a stunning shape, with an illusion that it was carried by its own light cone. It could be hanged on a wall, placed on a table, pushed against a ceiling or standing on the floor.Depending of its size the light cone from the light source lightens up the surface and draws attention to the otherwise forgotten wallpaper or the undisposed statue in the darkness of the city..

Inverkan av torrsubstanshalt och temperatur på kompostens syrabildning :

Composting is a process in which organic matter is mineralized by microorganisms. In January 2005 landfilling of organic waste was prohibited in Sweden. With this prohibition composting has become an important alternative to handle the produced organic wastes. One problem with continuous small-scale composting is the production of organic acids that will inhibit a further composting process. The aim of these theses was to study what effects temperature and dry matter content had on the production of organics acids, and what effect the organic acids had on the mineralisation of the substrate as well as the stability during storage of the product.

IMO:s barlastkonventions konsekvenser för sjöfarten inom Östersjön

Arbetet behandlade vilka konsekvenser inom driften (ekonomiska kostnader och teknologi) som rederier kommer att drabbas av när IMO:s barlastkonvention träder i kraft då barlastvattnet måste renas innan inträde i Östersjön. Arbetets syfte var att få fram vilka konsekvenser det blir för rederier när IMO:s barlastkonvention träder i kraft. Resultatet skulle jämföra skillnaden mellan lag och rekommendation då Helsingforskonventionens rekommendationer baseras på IMO:s barlastkonventions krav. En kvalitativ metod valdes för att komma fram till resultatet, i form av en öppen intervjustudie, där fyra olika företag har intervjuats. Syftet med intervjuerna var att se ifall de följde Helsingforskonventionens rekommendationer och vilka konsekvenser det skulle innebära och skulle komma att krävas då Barlastkonventionen träder i kraft.

Undersökning av vissa beläggningars påverkan på antenners effektivitet i tågmiljö

For several years Uppsala University together with several companies has been involved in a WISENET project aimed at improving railway transport security. By placing a sensor system near the wheels of each wagon, the temperature of the bearings can be measured and transmitted to a collector placed centrally on the wagon. This in turn transmits the collected data to RFID receivers placed intermittently along the railway.As the signals are transmitted wirelessly, problems may occur as the antennas get dirty or coated with ice and snow. To determine the effects of these coatings, several tests were performed examining the reflection coefficient S11, the impedance Z11 and the efficiency eta of an antenna, and how they varied when various coatings were placed over the antenna. Examined coatings were ice, snow and water to determine the effects of weather, and various metal-based coatings: powdered iron both pure and partially oxidized, and iron ore granules.

Resonans

This report describes how the system may be exposed to oscillations and how this can lead to resonance. Resonance is a phenomenon that occurs when a system is affected by external periodic oscillations with frequencies close to the system's natural frequencies. Structures subjected to resonance can risk great damage and destruction, why resonance is something that is important to take into account when designing structures. Alternative ways to counteract resonance is to supply damping in the system. Damping means that the resonance decreases instead of letting the amplitude increase.The report discusses some examples on constructions that have experienced the effect of resonance.

VISION SJÖSTAD : Flytande Bostäder

Floating housing is a concept gaining ground in Sweden. The dwellings are different in many ways from traditional homes, not only regarding flotation, but also several other technologies. The purpose of this thesis is to emphasize the qualities that exist in living on water. The ambition was to present a proposal for a floating residential area located in Jönköping, containing homes of varying sizes, and to present their technologies. In order to find inspiration and solutions studies have been made on existing floating homes in Stockholm and Kalmar, focusing on their technical and functional solutions.

Karakterisering och klassificering av gotländska ytvatten enligt ramdirektivet för vatten

In this study the practical work with the EU Water Framework starts on the island of Gotland. 33 lakes and 32 streams have been characterized and classified regarding to their ecological status. The aim with the characterisation is to create a uniform discription of all waterbodies and a comparable estimation for the future. The aim with the classification is both to study the waterbodies ecological status and to gain knowledge of where the resources should be concentrated so that the ecological status in all waterbodies will be good in 2015.The characterisation has been done according to the EU Water Framework Directive, and the factors that have been applied are the mean depth and area of the lake. The length and size on the catchment area are the factors that have been used on streams.

Idiopatisk cystit hos katt : en retrospektiv studie

Lower urinary tract diseases are a common problem in cats all over the world. The symptoms are for example dysuria, pollakuria, stranguria, periuria and hematuria. In approximately two thirds of these cats the underlying cause is not known and the disease is therefore called feline idiopathic cystitis (FIC). We need to know more about the disease to get a consistently effective treatment and prevention. A retrospective study was performed in 50 cats with symptoms of FIC and where other causes of inflammation were ruled out. Data like breed, age, sex, body weight, feeding, therapy and therapeutic results were collected, also if it was an indoor or outdoor cat, duration of the symptoms, if there was any stress and if the cat was living with another cat.

Spårning av miljöstörande ämnen i Uppsala stads spillvattennät

To the sewer systems households, industries and other activities are connected. The wastewater is collected at treatment plants where a nutritious sludge is produced. The sludge does not only contain nutrients, but also hazardous substances originating from different activities in society. To reduce the flow of hazardous substances to treatment plants and to create a sustainable recycling of plant nutrients the Swedish Water & Wastewater Association has developed the certificate system REVAQ. This certificate requires a good quality of the sludge but also that the treatment plants maps the origin of the unwanted substances.

Skadliga nollflödespunkter i Fortum Värmes fjärrvärmenät i Stockholm : En analys av dess förekomst och effekter

When several production units provide a district heating network, water is pumped from different directions. When the flows from the plants finally meet in the network, the water can be completely still. These places are called zero flow zones. In district heating networks with several plants, which also have different supply temperatures, large and frequent temperature fluctuations can occur when the zero flow zones move. This may cause wear on the pipes, a phenomenon called low cycle fatigue.For this reason it is important to examine where and when zero flow zones that cause temperature changes occur.

Säkring av samtliga kritiska skruvförband i mellanstora asynkronmotorer

The purpose with this thesis is to get a compilation of all the critical bolted joints of all enginesproduced at LV Motors. ABB LV Motors produces induction engines with seven shaft heights. Eachengine size exists several variants of components ex. standard shield and flange shield. Depending onwhich components the engine is equipped with arises various types of strains in the engine's parts,certain assembly ways are more favourable than other.The most critical parts in the engine from a mechanical point of view are the screw units betweenshield/stator, feet/stator and bearing cover/shield.

Elektrolytlösningar som vätsketerapi hos mjölkkor med löpmagsförskjutning :

Ten cows suffering from displacement of abomasum (DA) were treated with two different electrolytesolutions. The DA cows showed symptoms typical for the disease. Four out of 10 cows had a metabolic alkalosis and two a metabolic acidosis. The cows were mildly hypocalcemic, and 9 out of 10 were mildly to moderately hypokalemic. Six out of 10 cows showed muscle fasciculations.

Rostfärgat slam i dränagesystem vid vattenkraftsanläggningar : orsaker och åtgärder

From embankment dams is something that has long been noticed and given rise to different questions. The most serious question is if the sludge is a result of inner erosion through the dam, and thus consists of material transported from the dam. Concerns have also been raised whether the sludge could interfere with the systems drainage capacity and thereby lead to high pore pressure in the dam, or if the measurement of seepage is disturbed, as the measuring is usually made via Thomson weirs, which could risk being blocked. The result of this investigation shows that the sludge is a result of the oxidation of iron by iron bacteria, and to the greater part consists of these oxides as well as the bacteria?s own structures. The iron oxidizing bacteria, FeOB, oxides ferrous iron to ferric as a part of their metabolism, and thereby create large quantities of iron(oxy)hydroxides.

Luft/luftvärmepump : - Med möjlighet till återvinning

Sweden has long had access to low electricity prices due to the wide availability of hydro and nuclear power. This has now changed because of today's rising electricity rates resulting in increasing heating costs for properties, especially in the properties with electric heating systems."Ankaret" is a parish for "Svenska Alliansmissionen", which is located at "Gullbrannagården".The parish has installed electrical radiators and an exhaust ventilation system that makes the energy demand high due to the large ventilation flows. The building was built as the price of electricity was still low and would reduce energy use today by combining its heating system with an air/air heat pump. The heat pump delivers more heat into the room than the electrical energy that it uses. This lowers the electricity needs.

Energieffektivisering och solenergi i en universitetsbyggnad : Undervisningshuset och Biblioteket i Uppsala

Akademiska hus is a real estate company that specializes in providing Swedish universities with housing facilities for educational and research purposes. The company strives to reduce its use of energy by 40% between the years 2000 and 2025. The aim of this thesis is to determine which measures can be taken to reduce the need of purchased energy in a building that is used by theSwedishUniversityof Agricultural Sciences inUppsala.In order to determine the results of various changes to the building envelope and ventilation system, the building was modelled in the computer simulation program VIP-Energy. Other proposed changes to make the use of energy more efficient concerned water use and lighting. The need of purchased energy can also be reduced by producing electricity or heat on site, using solar energy.Results show that economically viable measures include upgrading windows and faucets, adjusting control systems for ventilation and lighting, and installing roof mounted solar panels for power production.

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