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739 Uppsatser om Organic rankine cycle - Sida 19 av 50
Economizer i bostadsvärmepumpar
I takt med stigande energipriser finner fler och fler det lönsamt att installera värmepump för att reducera sitt energibehov. Värmepumpar har dock svårigheter att tillgodose värmebehovet när utomhustemperaturen sjunker under -10°C. Detta problem kan minskas med så kallade economizerkopplingar, denna rapport jämför de båda economizersystemen flash tank cycle (FTC) och internal heat exchanger cycle (IHXC). Eftersom det har visat sig att vinsterna med economizerkopplingar är som störst då temperaturlyftet är stort är det mest intressant att jämföra dem i luft/vatten värmepumpar. Detta på grund av att övriga applikationer som berg-, jord- eller luft/luft-värmepumpar inte utsätts för samma stora temperaturvariation då utetemperaturen faller.
Fröodling av Raj- och rörsvingel i Sverige
Festulolium (Festulolium) and tall fescue (Festuca arundinacea) has not been grown inSweden over a longer period. So far there is no greater area cultivated, but the area isincreasing. Festulolium and tall fescue are expected to eventually replace meadowfescue in many leyseed mixtures to dairy cows in southern and central Sweden. Tallfescue has in recent years become popular again. Festulolium is a hybrid betweenryegrass and fescue.
Betesdrift vid automatisk mjölkning i ekologisk produktion :
An automatic milking (AM) system should be combined with some form of controlled cow traffic to minimize the time spend on fetching cows to milking and to increase the milking frequency. By restricting the hours spent on pasture per day you optimise the AM system use during pasture period. A reason for this is becuase cows do not return to the stable for milking during night which cause that the milking unit stands empty those hours. In organic production it is required that the cows should be able to graze a certain amount of daily dry matter (DM) intake on the pasture. In the county of Dalarna where the farm is located the yield of the pasture is about 3000 kg DM per grazing season and hectar.This means that the pasture area should be 14,25 hectare to 57 milking cows.
Kväve i Östra Mälaren : hur kunskap förvaltas och används i tillståndsprocesser
The nitrogen cycle in freshwater bodies is complex and consists of many separate processes affected by a number of important factors for example oxygen concentration in the water, temperature and circulation. Knowledge of the different components of the nitrogen cycle exists; however, a complete and comprehensive picture is difficult conceptually as well as theoretically. The available literature illustrates that the research on nitrogen and the related freshwater processes is still associated with high uncertainty of how much of the supplied nitrogen from the catchment is transported with the water versus and how much is lost due to denitrification, sedimentation or uptake by plants. This report is an interdisciplinary survey of Nitrogen discharge permitting. The research focuses in particular on the decision-making process, the levels of scientific standard and the administrative framework.Application for Nitrogen discharge permits are decided by the Environmental Court with council from their own experts as well as relevant government authorities and organisations.
EU ger eko bland korna - från uppbundet till lösdrift :
ABSTRACT
For hundreds of years there has been a tradition with tethered dairy cows in Sweden. The last
decades the old fashioned way to hold cows have been questioned and the number of dairy
cows in loose housing has been increasing. Last year (2004) 19 percent in total of all farms
with milk production in Sweden had their cows in loose housing. Because of EU-legislation
concerning all organic production no farms are allowed to build tie stalls any more and after
2010 all organic dairy cows are supposed to live in loose-housing systems.
The aim of the thesis was mainly to find out the number of farms with tethered organic dairy
cows and if they will continue after the year 2010. Furthermore the purpose was to study if
there are any regional differences, how countries similar to Sweden interpret the EU-decision
about tethered cows and differences in buildings between organic and conventional farms and
the reasons to them.
Studie av verkningsgrad potentialen för ett vatten baserat Waste Heat Recovery system med kolvexpander
SammanfattningEn ånganna monterades i EGR (Exhaust Gas Recirculation) slingan på en 12,7 liters Scania Euro V motor (DC1306). En modell som beskriver Rankine cykel togs fram med vatten som köldmedium i simuleringsverktyget GT-Power. Ångpannan i GT-power modellen kalibrerades m.h.a experimentell data.Simuleringarna visade att det optimala ångtrycket, det trycket där högst effekt kan erhållas från expandern, är beroende av EGR temperaturen. Det innebär att ju högre EGR inloppstemperatur desto högre optimalt ångtryck. EGR temperaturen i punkt 2 i ESC cykeln är 514? C för denna motor, vilket resulterar i ett optimalt tryck på 120 bar enligt simuleringen.
Konstruktion av ränndalskap CPD08
Our Bachelor?s Thesies has been performed in co-operation with Cellplast Direkt AB inLaholm. Our task was to develop a construction that cuts gussets to ceiling disposition as isused to isolation.Our goal with our construction was to increase the degree of automation so that theproductivity increased and also meet the market which is getting tougher and tougher due tothe future business cycle.Cellplast Direkt gave us free hands in order to enable new ideas. A pair different principleproposal was developed and prepared to a final structure.The Bachelor?s Thesies resulted in one PLC - governed machine with three engines that runthree different moves, wich does that the degree of automation increases and the risk forerrors decreases.We have developed a complete production bases to Cellplast Direkt and our hope is that thecompany comes to produce the machine in the future..
Utvärdering av olika sätt att hantera avloppsslam i Värmdö
Important issues for the local authorities are what to do with the sludge produced insewagetreatment plants. The tax for landfill leads to higher costs with 250 SEK/ton. On the 31December 2004 it will be forbidden to landfill sludge.In Sweden the yearly production of sludge is 240 000 tons, counted as DS. The phosphorouscontent is 3 % in sludge. The total yearly production of sludge gives 6000 tons of phosphorous.
Biogaspotential vid samrötningav mikroalger och blandslam från Västerås kommunala reningsverk
Because of the increasing trends in energy consumption and increased environmental awareness, greater focus has been placed on improvement and development of renewable energy sources. An already proven and accepted method is biogas production from anaerobic digestion at municipal wastewater treatment plants.In the waste water treatment process solid material and dissolved pollutants are separated from the water, forming a sludge. The sludge is separated from the process and stabilized during anaerobic digestion or aerobic aeration. Most often, mesophilic anaerobic digestion is used. Because of degradation by microorganisms, biogas with a high content of methane is formed during the digestion.
Värdet av aktierekommendationer
This paper presents a study that evaluates the performance of stock recommendations issued on Swedish stocks during 2003. The selection of recommendations in this paper originates from banks, major brokerage firms and financial press located in Sweden. The total of 171 recommendations consisted of 99 buy recommendations and 72 sell recommendations. Forecast revisions presented in this paper suggest that Investment managers have no ability to predict performance winners, nor do their forecasts in general have any significant impact on stock prices. A mere 50 percent of the recommendations in this revision had a weak ability to outperform their benchmark indexes as in other similar revisions.
EKODESIGN I INDUSTRIN : En lägesanalys av producenters problem, drivkrafter och framtida utmaningar inom ekodesign
SammanfattningProdukter produceras idag i stor utsträckning för att tillfredsställa konsumenters behov varpåmiljöbelastningen eskalerar i takt med efterfrågan och produktionen som sker därefter. Lösningenpå problemet kan sammanfattas i ekodesign där miljöoptimering av produktutvecklingen skerutifrån ett helhetsperspektiv; råvaruutvinning, produktion, användning, återvinning, slutligtomhändertagande samt transporter.Teknik-konsultföretaget ÅF uppmärksammade detta problem hos svenska producenter ochstartade 2008 en intern sektion, EcoDesign center, som erbjöd sina kunder ekodesignrelateradetjänster. Utmaningarna och problemen hos kunderna har med tiden förändrats och för att centretska kunna erbjuda sina kunder relevanta tjänster, undersöks i detta arbete svenska producentersrelation till ekodesign idag.Syftet med arbetet har varit att kartlägga producenternas problem och utmaningar inommiljöanpassad produktutveckling och samtidigt utvärdera ÅF EcoDesign centers förutsättningaratt tillgodose sina kunder. Att utifrån denna kunskap komma med förbättringsförslag ochrekommendationer på hur centrets ekodesigntjänster kan optimeras har varit målet med arbetet.Resultatet visar att ekodesignarbetet inte är tillräckligt utbrett vilket främst beror på bristfälligefterfrågan av ekodesignade produkter. Kundefterfrågan är direkt kopplat till ekonomiskaincitament, företag drivs i vinstsyfte och utan en efterfrågan kommer ekodesignarbete inteimplementeras.
Annonsmediers miljöpåverkan : när ska miljön få en reklampaus?
The aim of the thesis was to investigate energy consumption and carbon dioxide emissions from an advertisement broadcasted on the radio or the television or
distributed through press. The object was to calculate the amount of carbon dioxide emissions per individual receiver of an advertisement in Sweden. There was no room
for a deeper investigation into editorial work within the framework of the thesis.
Consequently, main focus of the radio and television study was on broadcasting itself and the components involved. Focus for the press study was on paper production,
printing and distribution. Production and discarding of media equipment was not taken into account.
Varför handla svenskt kött? : en konsumentundersökning
The background to the work bases on the consumers view around Swedish and foreign meat products, and how the attitude around the meat products is pursued in the shops.
The consumers request high meat quality and security . Many consumers value local produced and ecological meat products but the price is too high.
We have done verbal interviews with consumers on three different shops, where we asked questions and had dialogues around Swedish meat products where the consumers have told us their arguments and opinions about Swedish and foreign meat.
The result shows that the majority of consumers consider that it is important to know that meat is produce in Sweden.
Design av verklighetsanknuten matematikundervisning
The aim of this study was to design short interventions based on the literature study, which will change the pupils? posture on mathematics and connections between problem-solving in mathematics and everyday life. An experimental group of 17 pupils in fifth grade participated in the study and were educated in everyday mathematics 20 minutes a day during four weeks. The intervention was measured in a pre- and after questionnaire, in order to control the design and discover possible changes in the pupils? posture on mathematics and connections between problems and everyday life.
Dried distiller?s grains with solubles and Swedish grown soya beans as protein feeds for dairy bull calves
The cattle production in the world has been questioned in Sweden due to its negative impacts on the environment. The use of imported soya bean meal as a protein feed for Swedish cattle results in the cutting of rainforest and an extensive use of pesticides in the countries were the soya beans are produced. As a consequence, the environmental impacts caused by cattle production increases. A production of protein feeds in Sweden would decrease the transportations and the cutting of rainforest. For organic beef producers the possibility to produce home-grown protein feeds is important since organic protein feeds can be difficult to obtain in another way.