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1540 Uppsatser om Heat flow - Sida 18 av 103
Läsa och samtala : Vad betyder folkbibliotekets bokcirkel för användaren?
The aim of this Master?s thesis is to investigate the meaning the reading group of the public library has to a number of users. To fulfill the aim the following three questions have been formulated: 1) What do a number of users expect from the reading group of the public library? 2) Which approach/attitude or approaches/attitudes do a number of users have to reading and to talking about reading? 3) How do a number of users experience the ongoing reading group?The research is founded on qualitative interviews with five users that take part in three different reading groups in public libraries. The theories that are used is the theory of three so called strategies - the pragmatic, the traditionalistic, the emancipatory ? and the theory of flow.
Kompaktaggregat till Passivhus i Sverige
Kompaktaggregat är ett integrerat FTX- och FVP-system som används i passivhus. Vi har gjortenergiberäkningar i programmet VIP+ för att se hur kompaktaggregatet skulle kunna fungera ipassivhus i Sverige.De resultat vi har fått fram ur VIP+ visar att passivhus med ett installerat kompaktaggregat klararav att nå passivhuskraven ända upp till Skellefteå. De beräknade värdena understiger kraven förpassivhus, men en viss marginal behövs för att kraven ska nås även efter uppförandet avbyggnaden. Vi har även tolkat tekniska uppgifter på ett sätt som enligt oss har en positiv effektför passivhus på kallare orter. Därför tror vi inte att värdena för de tre nordligaste platserna ärhelt tillförlitliga.
Självkörande fordon : En analys av energianvändning och kapacitet
Self-driving cars are soon to become a reality to the commercial market. A self-driving car does not have a human operator, which enables some interesting characteristics. The main benefits are considered to be:The number of accidents and traffic jams should be reduced.Enhanced comfort.Energy usage could be decreased while capacity could be increased.This study concerns the causes for improved energy efficiency. The reason for improved energy efficiency is mainly because of the variation in terms of acceleration, braking and distance holding are reduced. The vehicles are more intelligent and can work together as a unity.
Simulering av översvämningar i Byälven
Severe floods caused by heavy autumn rains in year 2000 raised the question whether measures to reduce the damage from high water levels, in the area surrounding lake Glafsfjorden and along the river Byälven down to lake Vänern, are possible. One option is to reduce flow resistance along the river and thereby lower the maximum water level a given inflow would cause. Good knowledge of hydraulic and hydrological conditions is necessary in order to estimate the effect of such flow-reducing measures. In order to quantify such effect a 1-dimensional hydraulic flow model has been set up for the river Byälven using the software package MIKE 11. The model is more detailed, especially concerning topography and bathymetry, than earlier models used for studies of the river.
Kompaktaggregat till Passivhus i Sverige
Kompaktaggregat är ett integrerat FTX- och FVP-system som används i passivhus. Vi har gjortenergiberäkningar i programmet VIP+ för att se hur kompaktaggregatet skulle kunna fungera ipassivhus i Sverige.De resultat vi har fått fram ur VIP+ visar att passivhus med ett installerat kompaktaggregat klararav att nå passivhuskraven ända upp till Skellefteå. De beräknade värdena understiger kraven förpassivhus, men en viss marginal behövs för att kraven ska nås även efter uppförandet avbyggnaden. Vi har även tolkat tekniska uppgifter på ett sätt som enligt oss har en positiv effektför passivhus på kallare orter. Därför tror vi inte att värdena för de tre nordligaste platserna ärhelt tillförlitliga.
Småhusutformning och solenergiutnyttjande
This paper goes through solar energy and what uses it has. It is also a guide in the choice of solar collectors forthe real estate that I have drawn for the thesis work.Solar energy is a renewable source of energy from the Sun's light. Energy can be used to produce both heat andelectricity through solar collectors and solar cells. Some of the benefits of solar energy is that it is completely freeto extract, environmentally friendly and virtually maintenance-free. Disadvantages are that the technology isexpensive, does not cover the entire energy needs and takes a long time until it pays.
Synoptisk provtagning i vattendrag med eutrofieringsproblem : En studie för att identifiera områden för prioritering av åtgärder
In Halland, agriculture is the major source of eutrophication of water. In the study, synoptic sampling were performed in the three watercourses Nyrebäcken, Skintan and Vinån all located in the county of Halland. Sampling occurred during the period February to May on three occasions with different flow rates: high, low and base flow. Samples were taken in the mainstream and tributaries with intention to show how big the impact of eutrophication it is in the water and to assess the impact of the tributariesThe results show that all watercourses are affected by eutrophication. Nyrebäcken has the highest concentrations of nitrogen and phosphorus in the mainstream, then Skintan and last Vinån.
Underlag för bedömning av energibrunnar inom vattenskyddsområde
Denna rapport beskriver arbetet med utvecklingen av en ny modell för kaplanturbiner. Utvecklingen bygger på två kopplade differentialekvationer som under arbetets gång anpassats och implementerats i turbinmodellen.Modellen beskriver hur vattenflöde och turbinmoment påverkas av avvikelsen från den optimala kombineringskurvan för vinklarna på turbinens ledskena och löphjul, och är anpassad för ett referensaggregat med tillgängliga provdata. Även övriga enheter i vattenkraftaggregatet modelleras och sätts samman med frekvensregulator och elnät för att simulera aggregatets reglerstabilitet i önätsdrift.Verifieringen av turbinmodellen sker genom försök att återskapa de befintliga verkningsgradskurvorna med hjälp av modellen. Resultatet visar en god följning av de verkliga kurvformerna, dock med något lägre maximal verkningsgrad.Verifieringen av önätmodellen sker genom att prova stabiliteten i nätfrekvens och turbineffekt vid stegpålastningar. Resultatet ger en stabilare reglerstabilitet än i verkligheten, men uppfyller ändå förväntningarna på en fungerande modell.This report describes the development of a new kaplan turbine model.
Energy efficient storage of biomass at Vattenfall heat and power plants
Storage of biomass is often associated with problems such as heat development, dry
matter losses and reduction of fuel quality. The rise in temperature can potentially
cause a risk of self-ignition in the fuel storage. Moreover, emissions from storage piles
can cause health problems in the surrounding. The dry matter losses and reduction of
fuel quality can have economical effects. The aim of this thesis project is to develop
guidelines on how to store large amount of biomass at Vattenfalls heat and power
plants in an optimal way.
Biogasanvändning vid Käppalaförbundets Reningsverk: ? en värdering av miljöeffekter
This thesis calculates and compares the values of improved environmental quality due to future possible investment alternatives in biogas production facilities at Käppalaförbundets Reningsverk (Käppala Sewage Treatment Works) in an attempt to determine which alternative yields the highest such value. Käppala faces three investment alternatives for the usage of biogas. The alternatives are production of vehicle fuel, district heating and thirdly, heat and power production. Estimates of the value of environmental change are calculated for each of the three investment alternatives, and these estimates are then compared. The environmental change in question is the change in discharge levels of carbon dioxide (CO2), nitrogen oxides (NOx), sulphur dioxide (SO2) and particle matter.
Val av teknik för hastighetsmätning i kallvalsverk
An often encountered problem when implementing a mass flow regulator in a rolling mill is the one with measurement of speed. The most widely used solution is to fit a pulse counter to a wheel that is in contact with the strip. Common problems with this design are for instance scratch marks on the strip and problems with the flatness measuring system. One way of circumventing the aforementioned problems would be a non-contact measuring system. The market of today only offers systems based on the Doppler principle.This report evaluates three different systems for non-contact speed measurement. Important areas in the evaluation have been the ability to operate under normal rolling conditions, integration in existing control system and how well the sensor can be fitted to the rolling mill.
Konsekvenser av ny teknik på en sjukhusmottagning
An often encountered problem when implementing a mass flow regulator in a rolling mill is the one with measurement of speed. The most widely used solution is to fit a pulse counter to a wheel that is in contact with the strip. Common problems with this design are for instance scratch marks on the strip and problems with the flatness measuring system. One way of circumventing the aforementioned problems would be a non-contact measuring system. The market of today only offers systems based on the Doppler principle.This report evaluates three different systems for non-contact speed measurement. Important areas in the evaluation have been the ability to operate under normal rolling conditions, integration in existing control system and how well the sensor can be fitted to the rolling mill.
Förutsättningarna för ett parallellt generation IV system vid svensk nybyggnation av kärnkraft.
A new build in the Swedish nuclear power system would entail increased re-quirements for the proposed repository, which is adapted after the reactors of today. With a fast reactor, capable of burning nuclear waste, operating in parallel with the light water reactors, the increased requirements on the repository could be reduced.In this thesis, simulations of a light water reactor and a fast reactor have been performed by using the Monte Carlo code Serpent to investigate the changes in the fuel inventory. The light water reactor in the study is a boiling water reactor and the fast reactor of the type sodium-cooled fast reactor and they have been used for three different operation scenarios.By studying the fuel composition and the results from the simulations of the three scenarios conclusions can be drawn. Conclusions regarding the change of the fuel inventory and decay heat in Clab as well as the interim storage facility and in the repository. Depending on the operation alternative the changes dif-fered significantly and especially regarding the mass of burned actinides for different fuels in the fast reactor.The lowest increase of fuel assemblies was meet when using 50 years old fuel with 20MWd/kg U burnout and 2,0 % enrichment for start up of the fast reactor and 30 years old fuel assemblies with 50MWd/kg U burnout and 4,7 % enrichment for the further operation of the reactor.The increase of the number of fuel assemblies was 3174, which is equivalent to 641tons of heavy metal.
Biochar as soil amendment in flow-through planters - for increased treatment of zinc roof runoff
In times of increased flooding, enhanced by climate change, polluted stormwater poses an increased threat to the environment through contaminated water entering waterways. Bioretention utilizes natural processes in soil and vegetation to treat pollutants and combat this threat. Biochar produced through pyrolysis, has a high cation exchange capacity (CEC) and could therefore increase treatment in bioretention systems. This research applies a literature review, interview, and a model to explore the benefits and disadvantages of biochar in order to specify a soil-mix through an understanding of the production process and preferred application rate. High purification through CEC, increased water holding capacity, and carbon sequestration being the benefits discussed.
Noble Operations: En studie av Stadshuskällarens processflöden
The aim of this thesis is to study Stadshuskällaren?s operational processe flow and identify their operational characteristics. The uniqueness of Stadshuskällaren is that they are breaking the law of trade-offs regarding volume/variety, much like Toyota managed to do ? which spawned the entire field of research of the ?Lean Philosophy?. In the thesis the characteristics we identify through analysis, which enables Stadshuskällaren to break the trade-off, are compared with the principles of Lean service theory, which ultimately stem from Toyota.