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567 Uppsatser om Pollution load - Sida 28 av 38
Ett kandidatexamensarbete inom lättviktskonstruktioner .
Due to recent legal enactments regarding carbon dioxide emissions, the car industry is facing higher demands. An effective way of reducing these emissions is to minimize the weight of the vehicle. This thesis constitutes a feasibility study on whether or not it is applicable for the car industry to utilize an inner floor structure comprising composite materials. The principal was the projectSåNätt, in which the main participant was Volvo Cars Corp. In consultation with a reference group, consisting of delegates from the industry and KTH, a specification of requirements was produced.
Miljöhänsyn vid offentlig upphandling :
One of the biggest challenges in the human history is to prevent environmental pollution. Everybody has an indirect or direct influence on the environment through his or her consumption. The stakeholders are not just interested in price and quality, they are also interested in the circumstances of production and how this affects the environment. By taking environmental concern in public procurement it is possible to speed up the environmental adjustment of services and products. Environmental awareness has become more and more self evident in the environmental work.
Innovativ utmatningsteknik : Mediumstor bulkförvaringslösning
This master thesis was done for a company called BRUKS which is active in woodprocessing,bio-energy and bulk material handling industry. The idea for the master thesis wasto develop a new reclaiming method for silos where wood chips are being stored. A mediumsegment of between 1000 ? 5000 m3was defined as the segment with the most sales potential.Two different concepts were produced, one for new constructions and one for rebuildingalready existing silos.In the beginning of the master thesis a lot of time was spent on visiting different BRUKSoffices and customers to get an overview of the industry and the product. This informationwas the basis when the idea generating phase began.
Trygg belysning i stadens mörker : med en studie av Central Park, New York City, USA
Syftet med denna kandidatuppsats är att ge en ökad förståelse för ljusets betydelse för att människor ska känna sig trygga i städers offentliga rum efter mörkrets inbrott. Mörkret har alltid skrämt människan och varit en begränsande faktor i det vardagliga livet. Som skydd och för att kunna utnyttja dygnet på bästa sätt har ljus använts i otaliga former genom åren; allt från eld till elektricitet. Det artificiella ljuset har haft en stor betydelse för hur vi idag kan leva våra liv.
Trots att dagens städer är fulla av ljus under dygnets mörka timmar finns en otrygghet bland många att röra sig i stadens offentliga rum efter mörkrets inbrott.
Sustainable shopping : consumer behavior in purchasing and donating secondhand clothes
Textiles are made in an unsustainable way and there is a need to find alternative ways and material to reduce the negative impacts on the environment, humans and animals. Problems like pollution, excessive water consumption and loss of soil fertility is a result of this lack of diversity. It is a necessity to find innovative alternatives in other fabrics due to the unsustainable use of cotton and polyester fibers. As in many other countries in the Western part of the world, in Sweden there is a rapid turnover and increased selling of clothes that result in increased textile waste. About 15 kilogram of textiles (net inflow) is consumed per person each year.
Grundvattenskydd och markanvändning i tre olika länder- effekter för miljö och samhälle
AbstractDrinking water is an important resource on Earth both for humans and animals. Although most of the surface is covered by water only a small quantity is available as drinking water. Our manner of living creates a lot of pollution which has an environmental impact. Groundwater has a protracted turnover time in the soil and it can take many years before the effects of human impact are detected. The Swedish environmental object is ?Good groundwater quality? which aims to provide a safe and sustainable supply of drinking water today and in the future.
Fem-studie av rörelser i planet mellan bakaxelbrygga ADA1100 och centralväxelhuslock R780
This thesis has been performed at Scania CV AB Technical Centre in Södertälje and its aim hasbeen to study the causes and effects of deformations in the interface between the rear axlehousing ADA1100 and the central gear house R780 during operation. Design changes that wouldincrease the sealing capability of the studied interface are also suggested. Finite element (FE)and CAD software have been the primary tools in this study.Finite element (FE) simulations are used in the industry to predict and develop engineeringdesigns. The main motive for FE simulations has traditionally been to identify weak spots in thedesign, regarding high tensions and large deformations.The FE model is an aggregation of submodels and interface models that represents the rear axlehousing, suspension, central gear, central gear housing, wheels, bolts and weldings, and theirinteractions. The submodels have different material properties and they are connected withcontact interface models.Boundary conditions are defined on the bushings in front of the rear axle and on the air bellowsbehind the rear axle.
Inställning av automatikermed spänningsreglerande verkani det sydsvenska 400-130 kV nätet
The voltage level in the power grid varies due to variations in load and production. Normally these variations are manageable, but they may be excessively large during a disturbance. If the voltage is too high it may damage the equipment in the grid and too low voltages may cause problems like voltage instability. The magnitude of the voltage variation depends on the short circuit power capacity of the point of interest.This problem may become lore prominent due to automatic voltage regulation that acts on shunt reactors and shunt capacitors. When the shunt reactor is connected or disconnected to the grid it may cause such large changes in the voltage that the shunt reactor starts hunting.
Chassiintegrerade lastceller : Installation i fjädersäte på Scania tandemboggibakaxlar
The thesis presented in this report has been made on behalf of Scania and their basic frame design department with the subject to solve an implementation of a weight sensing system in the chassis. The system is supposed to be implemented in the seat springs, and the reason for this is that all the force will have to go through the weight sensing transducers. With all the force going through the transducers the weight sensing system will not be sensitive for the differences in tolerances from manufacturing. The transducers could be pre-calibrated to avoid a calibration of the whole vehicle after it?s completed from the manufacturing line.Weight sensing systems is today a reality in trucks with air springs.
SPICA - ARISTO JÄMFÖRELSE studie av analysprogram med avseende på spånningskollaps i elektriska kraftsystem
Safe operation of a large synchronous power system as Nordel is not an easy task.There are several aspects to take into consideration. This thesis focuses on the problems due to voltage collapses in a transmission system.The ability to foresee an upcoming collapse is vital to maintain stable operation of the grid. The grid operator at Svenska Kraftnät (SvK) uses the computer program SPICA to predict the maximum transfer limit at specified transfer sections. SPICA uses actual states from the grid to predict the transfer limitation, and a quarter later a renewed estimate is produced and so on. This means that the operator can se his transfer limits vary every fifteen minutes.Our task in this project is to validate the accuracy of the limitations obtained by SPICA.
Optimerad styrning av kondensatorbatterier - Ny möjlighet att minska förluster med elektronisk brytteknik
Transmission of reactive power is well known to cause active power losses. Thus, newcomponents who can help minimizing these expensive reactive power flows are ofgreat interest to the power distribution companies. ABB Corporate Research hasdeveloped the first electronic power breaker. One possible application for thisbreaker is transient-free switching of capacitor banks. This could prove a usefuldistribution voltage complement to the switch-sync technique, mainly applied to transmissionvoltage level.
Arkitekttävlingar : fallstudie : projekttävlingStockholmsporten
The population growth and urbanisation in low-income countries bring issues of poor living standards and miserable sanitation conditions onto the agenda. If well-functioning waste management systems were developed, this could master some of the problems. The already existing local informal waste handling system that is common in many low-income countries, needs to be developed with proper sorting and composting solutions to decrease the environmental burden and improve the overall situation in the dense cities.
This master?s thesis project is performed with the intention of developing functional decentralised waste management units in the city of Pune, India.
AKR:s inverkan på betongkonstruktioners bärförmåga
Alkali-kiselsyrareaktionen (AKR) är en kemisk reaktion som medför att spänningar uppstår i betongen då den bildade silikatgelen expanderar. Reaktionen kräver tillräcklig hög alkalihalt, reaktiv ballast samt vatten. På grund av de AKR-inducerade spänningarna är det av intresse att få kunskap i hur reaktionen påverkar betongens böjmomentkapacitet, förankring samt skjuvnings- och genomstansningskapacitet. För att besvara frågeställningen har därför en omfattande litteraturinventering tillsammans med tre kompletterande intervjuer utförts. Resultat som har erhållits, påvisar att två huvudsakliga effekter fås av AKR.
Hur förorenad är Tämnaren av Tungmetaller? En undersökning av bottensediment.
Tämnaren är en slättsjö i östra Svealand där ammunition går att finna i bottensedimenten. Ammunitionen härstammar från övningar som Flygvapnet hade över sjön under 1950- och 1960-talen. Sjön är mycket grund och näringsrik och befinner sig i ett område som fortfarande påverkas starkt av landhöjningen orsakad av den senaste inlandsisens tillbakadragande. Detta innebär att Tämnaren växer igen i rask takt och beräknas vara i princip borta om ungefär 600 år. Sjön har ett skyddsvärde dels genom sin rikedom på olika fågelarter som håller till i närområdet men också ett rekreationsvärde för människor i området runt sjön.
Projektering av ett småhus med fördjupning i uppvärmningssystem
This report aims to examine the design of a passive house. The design addresses the selection ofmaterial, sizing and selection of both building services systems and building technical features suchas load-bearing framework and moisture control. Interior layout is designed for a family of twoadults and one child.A big part of the report is devoted to an in-depth comparison of three different wall constructions ofpassive house standard. The structures that have been compared are a lightweight timber structure, aheavier concrete structure and a sandwich wall of the brand Weber Leca. The report covers variousaspects such as air flow, wall thickness, the risks associated with the construction, U-value, thermalbridges, power consumption, price, and assembly costs.