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1707 Uppsatser om Shower water heat exchanger - Sida 50 av 114

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.

Varför uppförs så få bostadsrätter med passivhusstandard i Sverige? : En fallstudie mellan ett passivhus- och en konventionell fastighet

Abstract Background: In 1997 the Kyoto Protocol was signed, it?s an international agreement which is aimed to reduce greenhouse gas emissions. Sweden's goal is to reduce energy using in buildings with 20 percent by 2020 and 50 percent by 2050. This is a comparison with levels from 1995 (Glad, 2006). For Sweden to be able to reach its goals, they need to construct more low-energy buildings (Åhman, Wahlström & Lundblad, 2010).

Kaffesump som substrat i biogasanläggningar eller som bränsle i fjärrvärmeverk : en studie av effekter på växthusgasutsläpp och kostnader

Each year, the coffee machines at Ericsson in Kista produce around 100 tons of ground coffee waste.The companies Coor Service Management, Löfbergs Lila and Selecta are all responsible for differentstages in the logistical chain in delivering coffee and, together with Ericsson, they want to increasetheir environmental benefit. The plan is to produce biogas through anaerobic digestion instead ofincinerating the coffee waste in a heating plant. The results are to be presented as different businesscases in which different biogas plants are compared with the reference case (heating plant),comparing costs and environmental impacts.There are two major environmental benefits from producing biogas; reduced carbon dioxideemissions from when fossile fule is replaced by carbon neutral biogas, and reduced emissions fromreturning digestate from the bio reactor to farmland instead of using industrial fertelizer.In order to determine the biogas potential in coffee waste, a couple of properties had to bedetermined in a laboratory. Properties such as the dry substance content, heating value, moisturecontent and ash content. The results show that 100 tons coffee waste could produce around 16 500Nm3 biogas which would contain 163 MWh.The biogas reactor and upgrade plant both need energy gas to function and uses around 14 MWh ofthe produced gas.

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.

Optimering av sotningsfrekvens i biobränsleeldad CFB-panna : panna 5, Mälarenergi AB, Västerås

During the past 30 years the fuels for energy production in heating and power plants have changed. Fossil fuels have decreased in usage whereas bio fuels in Sweden have increased with 60% since the 1970's. Different fuels affects combustion and the release of various substances and particles into the flue gas. This is caused by the diverse components and chemical structures of fossil fuels and bio fuels. When the flue gas leave the combustion chamber and enters the path to the chimney particles in the gas are being transported out of the combustion chamber.

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.

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).

Torkning av vallfrö :

In Sweden, grass is the single largest crop grown. Nearly 1 000 000 Ha grows on the fields, this is primarily used as feed for livestock. To get a good seed, you need to handle the crop carefully from planting to delivery. The part that I have been interested in, is how to dry the harvested seed with out destroying the growth in the small seed. This is very easily done if you aren?t careful during the drying period.

Allt är möjligt hus i Gustavsberg

In a sequence described in the next paragraphs, I remove the poorly insulated roof of Gustavsberg Porcelain Factory and make new use of its  foundation. The monolith cement slab, once supporting heavy industrial machinery, is now the site of lakes and other movements:The top floor area is split, and a new built volume, one story higher, overtakes the southern half resting on the factory?s basement, digging into it at its western and eastern ends. Striking horizontally, the fissure exposes a long central axis, taking advantage of the factory?s horizontality to articulate vastness .

Trycksatta huvudvattenledningar : Guide för material och schaktfria metodval vid åtgärder av vattenledningar

Detta examensarbete har utförts på uppdrag av Johan Lundberg AB som har haft ett behov av att det tas fram en guide vid åtgärder av vattenledningar. Åtgärder kan innebära nyläggning, utbyte eller renovering av en vattenledning. Syftet med rapporten är att ta reda på om ett visst material eller metod kan användas till vattenledningar, få fram för- och nackdelar med dessa material och metoder, både för installationsfasen och för driftsfasen. Detta görs ur ett långsiktigt tekniskt, ekonomiskt och miljömässigt perspektiv. Rapporten innehåller en faktadel med tänkbara material och schaktfria metoder och sju stycken intervjuer med ledningsägare har genomförts och en sammanställning av dessa intervjuer presenteras i kapitel 5.3.

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