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370 Uppsatser om Numerical simulations - Sida 16 av 25

Energianvändning i badhus : Simulering och jämförelse av gamla och nya system

Every year new premises are built in Sweden, and even if they are made as energy efficient as possible, this will not reduce the energy demands, but the rate of the increase of the energy use will be reduced. One type of facility in Sweden that is a major energy user is public baths, and this makes public baths an interesting facility to study more closely. There are around 500 public baths in Sweden and about 75 % of those can be seen as older baths with large need of renovation, and they all require a high level of energy efficiency measures. To show how the energy demand increase or decrease depending on the changes chosen to be made, the simulation application IDA Indoor Climate and Energy was used. Simulations were made and compared for several cases, with two extreme cases as starting points.

Ha?llbar sockerro?rsodling fo?r etanolframsta?llning i Brasilien : Hur slagkraftig a?r dagens ha?llbarhetscertifiering och kan den fo?ra?ndra mark- och vattenpa?verkan fra?n odlingarna?

Climate changes today are mainly caused by anthropogenic activities and the increased emissions of greenhouse gases to the atmosphere and this has raised questions on how to reduce the usage of fossil fuels. Ethanol is a good alternative to conventional gas and has been used in Brazil since the 1970 ?s. In Sweden several newspapers has written about the poor working conditions on many farms thus making the Swedish company SEKAB design a certification for their ethanol to ensure that it can be considered to be a sustainable alternative.Furthermore WWF has developed a certification tool called Bonsucro in cooperation with Coca Cola, Ferrero group, BP and Shell. This is due to the fact that no global certification tool has been available up until now.

Energikartläggning och energieffektiviseringsåtgärder i Zoologen på Göteborgs Universitet

The question of excessive global energy use needs to be solved. All energy production and usage have negative environmental impacts, which are best solved by reducing energy consumption and by using energy more efficiently. A large part of the Swedish energy use is concentrated to the building sector and to reduce the total energy consumption real efforts need to be made to make buildings more energy efficient.The aim of this study was to investigate how energy is used in one of Göteborg University?s buildings and to find measures that can be taken to improve its energy efficiency. The chosen building Zoologen, is used for research and education.The main method of the study is computer simulations of the present building and of possible energy reducing measures to be made in the future.

Torkning av flis med restvärme : Metoder för att sänka återledningstemperaturen

The purpose of this study has been to evaluate whether a Low temperature bio-mass dryer could be integrated with the local district heating system in Malå. The aim is to increase the thermal efficiency of the cogeneration plant in Malå, by lowering the temperature of the cooling medium. Another benefit that comes from this is improved combustion efficiency at the power plant, since drying the fuel causes an Increase of the heating value.Simulations has been made in Excel, and with use of linear regression, to find out if it is profitable. Data for this purpose has been supplied by the power company Skellefteåkraft and furthermore SMHI.The result of the Calculations shows that a very efficient bio-mass dryer is needed, if yield of investments should be made possible. An Investment of 4,27 Mkr, in a dryer, could at a such criterium return 60000 kr/year, if the price of the biomass is 190kr/MWh.

Hur ska tall- och gran bestånd i Götaland gallras för att minska risken för vindskador?

With knowledge of how the southern Swedish forests have been affected by storms the past years, this study intended to find out which factors affect the storm firmness of a stand the most. The study was based on data from stands in the, by the storm Gudrun, affected area. The results of the analyses that tested the stand factors that influence the amount of storm damage to the greatest extent showed that the storm sensitivity of Norway spruce stands were largely due to previous management actions. The factors that could be controlled by thinning and had relevance of storm damage standpoint, according to the results were; the dominant height, volume, basal area weighted mean diameter and stand age at last thinning. In this study, these results are not as clear for Scots pine.

Ämnestransport med grundvatten i hydrogeologiska typmiljöer

Certain types of waste, e.g. bottom ash originating from municipal solid waste incineration (MSWI bottom ash) can be used as road construction materials. A potential problem is the possibility of substances leaching out of the road and spreading in the surrounding groundwater.The aim of this master?s thesis is to conclude whether hydrogeological type settings can be employed to, based on local conditions, provide an estimate of the probable spreading of these substances in the surrounding groundwater, and whether certain types of soils can be identified as being less suitable for the localization of a MSWI bottom ash road. A hydrogeological type setting is defined as a mappable unit with similar hydrogeological properties.

Virtuellt ledarskap i näringslivet: Hur affärssimulering kan skapa kompetens, samsyn, och ökad ekonomisk förståelse i en organisation

The purpose of this thesis has been to explore the topic of business simulation from a theoretical foundation in social constructivism and theories concerning leadership as the management of meaning. The most important findings are that business simulation can be used for strategical leadership by management to create a common vision in the organisation members, which affects their perception of the business and the decisions and actions they make, which in turn can lead to a more efficient organisation that becomes better at meeting set goals. This can be viewed in different ways from different theoretical viewpoints: as inducing targeted changes in mental models to create changes in decision making and actions; as a secondary socialization process where the vision of management is externalized as a business simulation that is in turn internalized by the organisation members that participate in the business simulation, or as a way to frame and define the reality of the organisational members which creates a shared reference point against which a feeling of organisation and direction can emerge. In the future, business simulations may become increasingly used by organizations to create a common vision or to communicate a new decision to the organization members..

Rätt fönster i olika väderstreck : En undersökning av energieffektiva fönsters påverkan på byggnaders energiprestanda

The Swedish building stock accounts for nearly 40 percent of the total energyconsumption in the country. Properties built today are likely to last for 100 years orlonger. This places high demands on long-term and smart energy solutions that willkeep the future Swedish building stock energy consumption at low levels. This thesishas focused on examining how the energy performance of buildings is affected bydifferent choices of window types in different cardinal directions. The objective wasto obtain a basis for recommendations on how window properties can be optimizedfor different types of buildings and orientations.

Sawn softwood in Egypt ? a market study

This market study was written on behalf of Uni4 Marketing (U4M) and investigates the Egyptian softwood market. The objective was to identify what characterises a good softwood supplier according to Egyptian importers. In addition to this U4M?s competitiveness compared to their competitors was evaluated. The study also identified possible sources of competitive advantage possessed by U4M.

Utvärdering av en beslutsåterkopplad kanalestimator för tredje generationens mobiltelefonisystem

This Masters thesis work describes a comparison between two different methods for estimation of the down channel (base station to mobile subscriber) in Wide-band Code Division Multiple Access (WCDMA). The first estimation method, Optimal Feed-forward Channel Estimation (OFCE), is a conventional method that bases the estimates on data that is known to both sender and receiver, so called pilots. The second method, Decision Directed Channel Estimation (DDCE), is an elaboration of OFCE. It also uses user data for estimation. Simulations show that DDCE, in comparison to OFCE, does not attain an improvement in signal-to-noise-ratio (SNR) for high bit error rates (BER).

Energieffektiviserande åtgärderpå Robertsfors VA-nät : En förstudie av vilka energieffektiviserande åtgärdersom kan göras på pumpstationer och reningsverk

The objective of this work was to introduce measures to reduce energy and water demand at Gävle Söder 17:10. To succeed, this energy audit has been made. The work is based on collected statistics from the property owner Norrporten, measurements, literature review and through consultation with experts in the field. Two models, one for each building, have been created in the simulation program BV2 to estimate the potential of energy measures based on the collected information. The models in BV2 have been verified against the statistics of the energy consumption.With the help of calculations and simulations, seven cost-effective measures have been identified.

Utvärdering av tillgänglighet på Stora Ensos massabruk i Skutskär

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.

Analys av mellanspänningsnätet i centrala delar av Västerås stad

The dependency of continuous electricity supply is high in the Swedish society today, at the same time no one is willing to pay for a too costly or over dimensioned power distribution system. The owners of the distribution systems are the ones responsible for this balance act of maintaining a high quality of electricity delivery to customers at a reasonable cost.In this master thesis a limited part of the primary distribution system (10 kV), owned by Mälarenergi Elnät AB and located in the city centre of Västerås, was chosen for a deeper analysis of its reliability. Its ability to handle outages of system components (N-1 and N-2 contingency analysis) was investigated to find out potential weak spots and parts of the grid that showed signs of being overdimensioned.The results of the performed simulations showed that in 74 % of the studied N-1 contingencies cases, consisting of outages of a bus bar in a distribution substation, the system could handle this without causing outages in other parts of the grid. For the N-2 contingencies 61 % passed the test. It was also found that one of the two included high voltage substations could alone supply the investigated part of the grid.

Konstruktion och utformning av skydd till spolverk

This thesis has been carried out in cooperation with Burseryds Bruk AB.Burseryds Bruk is a company that manufactures steel strapping. The thesis isabout developing a concept of protection that should be used to protect theoperators from the rotating parts of the machinery lines. The aim of the projectwas to improve work safety for operators working at the machines by producing aconcept for a protective device. The project's first part was based on ergonomic data collection methods tounderstand the operations performed on the machine and the hazard occurringduring the process. The methods used to collect data were, interviews,observations and questionnaires with the operators of the company. This was thenused to make the ergonomic analyzes hierarchical task analysis and link analysis. The data collected from the company's operators was used create 10 conceptswhich were then evaluated.

Analog-to-Digital Converter Design for Non-Uniform Quantization

The thesis demonstrates a low-cost, low-bandwidth and low-resolution Analog-to- Digital Converter(ADC) in 0.35 um CMOS Process. A second-order Sigma-Delta modulator is used as the basis of the A/D Converter. A Semi-Uniform quantizer is used with the modulator to take advantage of input distributions that are dominated by smaller-amplitude signals e.g. Audio, Voice and Image-sensor signals. A Single-bit feedback topology is used with a multi-bit quantizer in the modulator.

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