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1901 Uppsatser om Water loss - Sida 43 av 127
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.
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.
Indelning av trakter inför gallring på Holmen Skog : en utvärdering av svårigheter och möjligheter
A common goal in practical forest management is to maximize the yield, measured in economical terms. When a forest stand is thinned a so called inoptimality loss can arise due to non-optimal decisions. This means that the selected management schedule results in a lower net present value than the optimal one which lowers the profitability for the forest owner. Holmen Skog uses the term tract which means an aggregation of stands made before a management action. A tract should be delineated in different tract parts in connection with pre-thinning planning if there is different bearing capacity within the tract, different thinning grades should be used or if the tract contains a weaker part that should not be thinned.
Personnnummer non grata- En kvalitativ studie om hur uppfattningen om äldre arbetskraft påverkar de äldres situation i arbetslivet och vid rekrytering
The average age of the working population in Sweden is increasing, along with the number of retirements. Meanwhile, the number of people entering the labour market is declining. In order to avoid a loss of key skills and competences because of the resulting labour gap, and to ensure future economic growth, it is vital to utilise the aging labour force more efficiently. Nevertheless, many Swedish companies are inefficient in managing their aging workforce. In fact, it has emerged that senior workers in Sweden are discriminated against their age and not attractive on the labour market.
En utmaning: Sjuksköterskans bedömning av smärta hos personer med demens.
People with dementia often have difficulties expressing their needs. Untreated pain within this group can be manifested as depression, agitation or loss in appetite. It can be a challenging task for a nurse to estimate, treat and evaluate pain for people with dementia. With good knowledge and an empathic approach, nurses can often recognize and relieve pain amongst these people. Despite this, litterature often suggest that unrecognized and untreated pain is common within this group..
Sammanvägda avrinningskoefficienter i rationella metoden : en jämförelse mellan idag och 1970-talet
Storm water is rain and melted snow that runs off, primarily from impervious surfaces.Future storm water management is facing the challenges of increased precipitation, asclimate changes, and increased areas of impervious surfaces due to the expansion anddensification of the cities. Impervious surfaces reduce the potential for water to infiltratein the ground leading to increased surface runoff and higher peak discharge.The runoff coefficient is closely related to the percentage of impervious surfaces andrepresents the maximum percentage of a catchment that can contribute to runoff. In thisstudy, the objective was to evaluate the weighted runoff coefficient for three differenturban types; apartment buildings, townhouses and residential areas and a comparisonbetween today and the 1970`s was made.The runoff coefficient was determined by manual mapping of the different surface typesin each area based on data in the form of orthophotos and aerial photographs. The surfacetypes that were mapped were asphalt, permeable areas, tiles, sand/gravel and roof.Tiles and sand/gravel were the most difficult surface types to map. In order to see towhat extent these categories influenced the weighted runoff coefficient a sensitivityanalysis was carried out and the runoff coefficient based on surface type was changed indifferent scenarios.The results of the sensitivity analysis showed that the surface types tiles and sand/gravelhad little impact on the weighted runoff coefficient which in mainly due to the fact thatthe percentage of these surfaces types of the total area is small.The result of the study showed that the largest change in the runoff coefficient occurredin residential areas where the increase in the percentage of impervious surfaces causedby new roofs in the form of porches and garages and from paved or tiled driveways.
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.
Nitrat i dricksvatten : jämförelse av nitrathalter, mellan åren 1975 och 2005
Ronneby Miljö- och hälsoskyddskontor ville genom undersökningen få information om nitrathalter ienskilda dricksvattenbrunnar inom kommunen, med bakgrund av den nya miljökvalitetsnormen.Riktvärdet för nitrat är 50 mg/l. Halter som överstiger detta bör inte ges till barn under ett års ålder pågrund av risk för methemoglobinemi. Jämförelsen skulle ske mellan områden präglade av jordbrukrespektive skogsbruk, samt mellan grävda och borrade brunnar. Jämförelsen skulle även ske över tiden,mellan 1975-1990 till 2005. Urvalet av provtagningspunkter baserades på en sammanställning frånbefintligt arkiv samt efter en annons i dagspressen.
Våtmarker i urbana miljöer : växtgestaltning och planering
The practice of landscape architectural involves forming the space in our cities and suburbs, as well as the landscape surrounding. The need of exploiting green environment leads up to, among other issues, flood problem during heavy rain and overfed water environments. The problem is partially caused by the shortage of knowledge, how the environment is responding of the innovations made by the city- urban planning and how to get sustainability.
Research and knowledge how to take care of our environment, in a natural way, is increasing. The object of the thesis is to propose control and balance in urban wetlands, and discuss the difference a plant design can do.
The thesis deals with discourses in the field of landscape architecture, biological diversity, dam construction, limnology, planting design and management, pollution of the environment and urban design practice.
Våtmarker för näringsretention i Lillån : var bör de ligga och vilken effekt kan vi förvänta
Construction of wetlands in the agricultural landscape may reduce nitrogen and phosphorus
transfer to streams, thereby reducing the eutrophication of lakes and seas. The agriculturalstream Lillån, a tributary to stream Sagån, ends up in Lake Mälaren and is transporting large amounts of these plant nutrients. The aim of this study was to estimate how hypothetical wetlands of different size and location may reduce nitrogen and phosphorus load from stream Lillån. Estimated nutrient retention in several small wetlands was compared to retention in a single large wetland based on existing data from the agricultural stream and from a nearby smaller stream. Retention in the stream was suggested to decrease along with the nutrient concentration in the water.
Klimatsäkrare städer : klimatförändringar, stadsplanering och översvämningar
The numbers of natural disasters caused by extreme weather are increasing through out the world. A large majority of the research concerning the climate shows that this is a trend that can be expected to continue. At the same time the urbanisation is increasing more than ever and for the first time in history more than fifty percent of the population lives in a city. How we build these cities will have a crucial importance for our adaption to the new climate. In Sweden, our capacity for an adaption are high because of our economic situation as well as our rather well built society.
Sekundärnät för lågtempererad fjärrvärme
Lower energy use in buildings is a result of increasingly stringent energy requirements across Europe. When conventional district heating technology is used in areas with low energy consumption heatlosses do not fall even though the amount of energy delivered is reduced. This reduces income for thedistrict heating company. To maintain their economic viability the district heating companies? majorchallenge is to implement new solutions that minimize heat loss.
Näringsretention i återskapad våtmark på betesmark : studier av en mad vid Bornsjön
It is important to construct or recreate different types of wetlands and study their retention of nutrients, since knowledge of their effectiveness in this matter is poor. In 2003 a wetland was constructed on an old meadow on the western shore of Lake Bornsjön in central Sweden. The main purpose of the wetland was to reduce the amount of phosphorus entering the lake, which is the back-up water supply for Stockholm when the city cannot obtain water from Lake Mälaren. Large areas around Lake Bornsjön consist of agricultural land and the nutrient concentrations in the inflows to the lake are usually relatively high (approx. 1 mg/l total nitrogen and 0.05-0.1 mg/l total phosphorus).