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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
211

Obten??o de novos derivados de ?-naftol e cardanol hidrogenado e avalia??o dos seus efeitos antioxidativos em gasolina automotiva

Dantas, Michelle Sinara Greg?rio 14 October 2005 (has links)
Made available in DSpace on 2014-12-17T15:01:57Z (GMT). No. of bitstreams: 1 MicheleSGD_tese.pdf: 2430121 bytes, checksum: 4479472ce6fc90295b8c785bc52f29fd (MD5) Previous issue date: 2005-10-14 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The chemical nature of the hidrocarbons found in gasoline directly affects the formation of oxidation complexes known as gums. Such complexes are slightly soluble in gasoline and their formation is delayed with the use of inhibitors, known as antioxidants. In this study, a synthetic compound (βnaphtol) and a natural subproduct (hydrogenated cardanol, derived from cashewnut shell liquid CNSL) have been used in order to generate novel antioxidant substances. These compounds were submitted to chemical reactions including alkylation, nitration and reduction, with the purpose of forming the following derivatives: 6(Nethyl,Nethylamino)βnaphtol (AO1); 6(Nethyl,Ndiethylamino)βnaphtol (AO2); aminoβnaphtol (AO3); 2(Nethyl,Nethylamino)pentadecylphenol (AOC1), 2(Nethyl,Ndiethylamino)pentadecylphenol (AOC2) and aminopentadecylphenol (AOC3). The derivatives were subjected to accelerated oxidative stability assays (Potential Gum and Induction Period) and to storage assays (Washed Gum and ASTM Color) during six months, with naphtha provided by the petroleum refinery RPBC (Refinaria Presidente Bernardes de Cubat?o, in Brazil). The results for the derivatives were compared to those for commercial additives [DBPC (2,6ditbutyl4methylpcresol) and PDA (N,N disecbutylpphenylenediamine)], which were also added to the naphtha produced at RPBC at the moment of sampling. From all tested antioxidants, the novel antioxidant AOC1 (derived from hydrogenated cardanol) yielded a better global performance. During the period of time in which the naphtha was stored, an examination of this material was carried out in parallel, using the mass spectrometry technique. This study allowed to monitor the formation of a triolefinic compound, as well as the observation of subsequent formation and rupture of the olefinic constituents. As an eventual result from these experimental investigations, a reaction route leading to gum formation has been suggested / O tipo de hidrocarboneto presente na gasolina influencia diretamente na forma??o de complexos de oxida??o conhecidos como goma. Estes complexos s?o levemente sol?veis em gasolinas e sua forma??o ? retardada atrav?s de uso de inibidor, conhecido como antioxidante. Neste estudo utilizouse um composto de origem sint?tica (βnaftol) e um subproduto natural (cardanol hidrogenado (derivado do l?quido da castanha de caju (LCC)) para obten??o de novas subst?ncias antioxidantes. Os compostos citados foram submetidos a rea??es qu?micas de alquila??o, nitra??o e redu??o para obten??o dos seguintes derivados : 6(Netil,Netilamino)βnaftol (AO1), 6(Netil,Ndietilamino)βnaftol (AO2), Aminoβnaftol (AO3), 2(Netil,Netilamino)pentadecilfenol (AOC1), 2(Netil,Ndietilamino)pentadecilfenol (AOC2) e Aminopentadecilfenol (AOC3). Os novos derivados foram submetidos a ensaios acelerados de estabilidade oxidativa (Goma Potencial e Per?odo de Indu??o) e a testes de estocagem (Goma Lavada e Cor ASTM) durante seis meses com nafta amostrada na RPBC (Refinaria Presidente Bernardes de Cubat?o). Os resultados com os novos derivados foram comparados ?queles obtidos com aditivos comerciais [DBPC (2,6diterbutil (4 metil)pcresol) e PDA (N,N disecbutilpfenilenodiamina)]que tamb?m foram adicionados ?s naftas da RPBC no momento da amostragem. O novo antioxidante AOC1(derivado do cardanol hidrogenado) apresentou melhor desempenho global dentre todos os antioxidantes amostrados. Durante o per?odo em que as naftas amostradas foram estocadas, foi realizado, em paralelo, um acompanhamento deste material atrav?s da t?cnica de Espectrometria de Massas e registrouse, n?o somente, a forma??o de um composto triolef?nico, como tamb?m acompanhouse as forma??es e as rupturas, subseq?entes, de compostos olef?nicos. Este acompanhamento possibilitou a sugest?o de uma rota reacional que leva ? forma??o de goma
212

Analys och jämförelse av två pilotanläggningar med olika sammansättning av membran : Vid rening av processvatten från industri

Nygren, Astrid, Slättengren, Robin January 2017 (has links)
Vattentillgången på Öland har under en lång tid varit mycket ansträngd och har kommit till en punkt då det inte längre är hållbart. För att nå en mer långsiktig lösning planerar Mörbylånga kommun med hjälp av Norconsult att bygga ett vattenreningsverk. Detta kommer att rena bräckt vatten ifrån Kalmarsund samt processvatten ifrån Guldfågeln AB, som tillsammans kommer att fungera som ett komplement till det redan befintliga sötvattnet. Två pilotanläggningar som renar processvatten ifrån en industri, genom ultrafilter kombinerat med omvänd osmos, har utvärderats. En metod för att sammanställa de kostsamma driftparametrarna elförbrukning, förbrukning av kemikalier samt underhållsarbete vid drift och membranens inköpskostnad genom en LCC har tagits fram. Denna metod ger en ungefärlig totalkostnad per kubikmeter av det renade vattnet. Även vattenkvaliteten på ingående råvatten, vattnet mellan membranen samt det utgående vattnet har analyserats. Detta för att undersöka att processerna fungerar som den ska, samt ge en indikation på vilka mineraler som kommer att behöva tillsättas i efterhand. Pilot B blir ca fem kronor dyrare per kubikmeter jämfört med Pilot A. De totala kostnaderna, 9.70 – 10.79 kr/m3 för Pilot A och 15.19 – 15.28 kr/m3 för Pilot B, kan jämföras med den nuvarande kostnaden för en kubikmeter vatten i Mörbylånga, 15 kr/m3, samt den kostnad kommunen betalade sommaren 2016 för att frakta vatten i tankbilar, 70 kr/m3.
213

Power Loss Evaluation of Submarine Cables in 500 MW Offshore Wind Farm

Jayasinghe, Lahiru Kushan January 2017 (has links)
The main objective of this thesis is to develop a new methodology to evaluate the transmission cable losses of wind-generated electricity. The research included the power loss variations of submarine cables in relation to the line length, cable capacity and the transmission technology in an offshore wind farm having a capacity of 500 MW. The literature of similar studies helped to generate a solid background for the research.   The comprehensive analysis carried out is based on a hypothetical wind farm and using three different power transmission wind farm models to investigate the technical reliability of transmission technology, namely, High Voltage Alternative Current (HVAC), High Voltage Direct Current Voltage Source Converter (HVDC VSC) and High Voltage Direct Current Line Commutated Converter (HVDC LCC). The analyses carried out are performed under assumptions and simplifications of power system models to evaluate the submarine cable transmission losses of 3 different transmission systems by using the MATLAB/ Simulink software.   With relevance to the simulation results, the HVAC submarine cable has more losses than any other transmission technology cables and it is suitable for short distance power transmission. The VSC technology has less losses than HVAC. Comparing with afore-mention technologies the HVDC LCC technology transmission links have the lowest line losses. Moreover, the transformer losses and the converter losses were calculated. The simulation results also included the overall power system losses by each of the transmission models.
214

Desenvolvimento de sensores eletroquÃmicos para detecÃÃo de molinato e Ãxido nÃtrico / Electrochemical sensors development for detection of nitric oxide and molinate

TÃlio Ãtalo da Silva Oliveira 01 March 2013 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / O presente trabalho ilustra o desenvolvimento de uma rota sintÃtica para a obtenÃÃo de uma meso-metaloporfirina, a partir de uma meso-porfirina base livre, macromolÃcula derivada do LÃquido da Casca da Castanha de Caju (LCC), subproduto do agronegÃcio do caju. A obtenÃÃo dessas espÃcies seguida de estudos preliminares da modificaÃÃo da superfÃcie do eletrodo de ouro com a meso-metaloporfirina de cobre com aplicaÃÃo para sensor de NO (Ãxido NÃtrico) tambÃm compÃe os objetivos desse trabalho. A partir do processo de metalaÃÃo,foi sintetizada uma meso-metaloporfirina utilizando Cu (II) como centro metÃlico, a partir da macromolÃcula base livre, e testes voltamÃtricos foram realizados utilizando o eletrodo de ouro, em meio de diclorometano e PTBA 0,1 mol L-1, obtido a 100 mV s-1.Estudos foram realizados a cerca do comportamento eletroquÃmico dos filmes formados em presenÃa de NO em meio aquoso de Na2SO4 0,5 mol L-1 obtendo o voltamograma cÃclico para o eletrodo de ouro modificado com a porfirina de cobre(II) na detecÃÃo de NO e foi observado no voltamograma para NO sobre uma intensidade de corrente 7,6 vezes maior comparada à do pico observado para o mesmo processo do NO na superfÃcie de ouro nÃo modificado demonstrando elevado potencial para aplicaÃÃo como sensor eletroquÃmico. Outra metodologia eletroanalÃtica foi desenvolvida para a obtenÃÃo de um biossensor, baseado em uma enzima, glutationa-S-transferase (GST), para determinaÃÃo do pesticida molinato, um herbicida prÃ-emergente, em amostras reais de Ãgua de campos de arrozais da cidade do Porto, em Portugal. A construÃÃo deste biossensor baseou-se a imobilizaÃÃo de GST em um eletrodo de carbono vÃtreo (GCE), atravÃs da ligaÃÃo covalente glutaraldeÃdo-amino-silano (APTES/GA). O princÃpio deste biossensor consistiu no processo de inibiÃÃo da GST promovida pelo molinato. A curva de calibraÃÃo foi obtida por meio da tÃcnica de voltametria de pulso diferencial (VPD) variando a concentraÃÃo do pesticida entre 1,01x10-6 â 4,20x10-5 mol L-1 apresentando um limite de detecÃÃo (LD) de 0,064 mg L-1. O biossensor baseado na GST foi aplicado para quantificar o molinato nas amostras de Ãgua das lavouras de arrozais. Os resultados obtidos com este biossensor foram comparados com aqueles obtidos por HPLC e nÃo houve diferenÃas estatisticamente significativas comprovando, entÃo, que a metodologia desenvolvida foi precisa no nÃvel de concentraÃÃo estudada. / This study illustrates the development of synthetic route will be obtaining meso-metalloporphyrin, from porphyrin meso-free base macromolecule derived from Shell Liquid Cashew Nut (CNSL), byproduct of cashew agribusiness. Obtaining these species followed by preliminary studies of surface modification of gold electrode with copper meso-metalloporphyrin with application to sensor of NO (Nitric Oxide) also composed the objectives of this work. From metalation process, was synthesized by meso-metalloporphyrin using Cu (II) the a metal to center, from the macromolecule free base, and voltametric tests were carried out using the gold electrode in the middle of dichloromethane and TBAP 0,1 mol L-1, obtained at 100 mV s-1. Studies have been conducted about the electrochemical behavior of the films formed in the presence of NO in aqueous Na2SO4 0,5 mol L-1 the cyclic voltammogram obtained will be the gold electrode modified with porphyrin to copper (II) the detection of NO and voltammogram was observed in about one NO to current intensity 7,6 times larger compared to the peak observed for the same process of NO in unmodified gold surface showing high potential for application as an electrochemical sensor. Electroanalytical another methodology was developed will be obtaining the biosensor, based on an enzyme, glutathione-S-transferase (GST), will be determining the pesticide molinate, the real daily pre-emergent herbicide in samples of to water of paddy fields City Porto, in Portugal. The construction of this biosensor was based on the immobilization of GST in glassy carbon electrode (GCE) by covalent glutaraldehyde-amino-silane (APTES/GA). The principle of this biosensor consisted of the process promoted by inhibition of GST molinate. The calibration curve was obtained by the technique of differential pulse voltammetry (DPV) varying the concentration of the pesticide between 1,01 x10-6 to 4,20 x10-5 mol L-1 having a limit of detection (DL) of 0,064 mg L-1. The biosensor based on GST was applied to quantify the molinate in water samples of paddy crop. The results obtained with this biosensor were compared with those obtained by HPLC and no statistically significant differences proving therefore that the developed methodology has been studied in terms of concentration.
215

Integrate Building Information Modeling (BIM) and Sustainable Design at the Conceptual Stage of Building Projects

Jalaei, Farzad January 2015 (has links)
Lately the construction industry has become more interested in designing and constructing environmentally friendly buildings (e.g. sustainable buildings) that can provide both high performance and monetary savings. Analyzing various parameters during sustainable design such as Life Cycle Assessment (LCA) and energy consumption, lighting simulation, green building rating system criteria and associated cost of building components at the conceptual design stage is very useful for designers needing to make decisions related to the selection of optimum design alternatives. Building Information Modeling (BIM) offers designers the ability to assess different design options and to select vital energy strategies and systems at the conceptual stage of proposed buildings. This thesis describes a methodology to implement sustainable design for proposed buildings at their conceptual stage. The proposed methodology is to be implemented through the design and development of a model that simplifies the process of designing sustainable buildings, evaluating their Environmental Impacts (EI), assessing their operational and embodied energy and listing their potential accumulated certification points in an integrated environment. Therefore, a Decision Support System (DSS) is developed by using Multiple Criteria Decision Making (MCDM) techniques to help design team decides and selects the best type of sustainable building components and design families for proposed projects based on three main criteria (i.e. Environmental, Economical factor «cost efficiency » and Social wellbeing) in an attempt to identify the influence of design variations on the sustainable performance of the whole building. The DSS outcomes are incorporated in an integrated model capable of guiding users when performing sustainable design for building projects. The proposed methodology contains five modules: 1) Database Management System (DBMS), 2) Energy and lighting analysis, 3) Life Cycle Assessment (LCA), 4) LEED and 5) Life Cycle Cost (LCC). To improve the workability of the proposed model, a use case of abovementioned modules are going to be created as plug-ins in BIM tool. The successful implementation of such a methodology represents a significant advancement in the ability to attain sustainable design of a building during the early stages, to evaluate its EI, and to list its potentially earned certification points and associated soft costs.
216

Uncertainty in life cycle costing for long-range infrastructure. Part I: leveling the playing field to address uncertainties

Scope, Christoph, Ilg, Patrick, Muench, Stefan, Guenther, Edeltraud 25 August 2021 (has links)
Purpose Life cycle costing (LCC) is a state-of-the-art method to analyze investment decisions in infrastructure projects. However, uncertainties inherent in long-term planning question the credibility of LCC results. Previous research has not systematically linked sources and methods to address this uncertainty. Part I of this series develops a framework to collect and categorize different sources of uncertainty and addressing methods. This systematization is a prerequisite to further analyze the suitability of methods and levels the playing field for part II. Methods Past reviews have dealt with selected issues of uncertainty in LCC. However, none has systematically collected uncertainties and linked methods to address them. No comprehensive categorization has been published to date. Part I addresses these two research gaps by conducting a systematic literature review. In a rigorous four-step approach, we first scrutinized major databases. Second, we performed a practical and methodological screening to identify in total 115 relevant publications, mostly case studies. Third, we applied content analysis using MAXQDA. Fourth, we illustrated results and concluded upon the research gaps. Results and discussion We identified 33 sources of uncertainty and 24 addressing methods. Sources of uncertainties were categorized according to (i) its origin, i.e., parameter, model, and scenario uncertainty and (ii) the nature of uncertainty, i.e., aleatoric or epistemic uncertainty. The methods to address uncertainties were classified into deterministic, probabilistic, possibilistic, and other methods. With regard to sources of uncertainties, lack of data and data quality was analyzed most often. Most uncertainties having been discussed were located in the use stage. With regard to methods, sensitivity analyses were applied most widely, while more complex methods such as Bayesian models were used less frequently. Data availability and the individual expertise of LCC practitioner foremost influence the selection of methods. Conclusions This article complements existing research by providing a thorough systematization of uncertainties in LCC. However, an unambiguous categorization of uncertainties is difficult and overlapping occurs. Such a systemizing approach is nevertheless necessary for further analyses and levels the playing field for readers not yet familiar with the topic. Part I concludes the following: First, an investigation about which methods are best suited to address a certain type of uncertainty is still outstanding. Second, an analysis of types of uncertainty that have been insufficiently addressed in previous LCC cases is still missing. Part II will focus on these research gaps.
217

Life Cycle Costing - Systematisierung bestehender Studien

Höhne, Christoph 30 April 2010 (has links)
Die vorliegende Arbeit untersucht Wesensmerkmale des Life Cycle Costing (LCC, dt. Lebenszykluskostenrechnung) und dessen Anwendung veröffentlicht in Fachzeitschriften. Aufgrund der langen Historie des LCC seit Beginn der 30er Jahre, gibt es zu dem Forschungsthema bereits eine Vielzahl theoretischer und empirischer Studien. Dennoch existiert bis heute keine einheitliche Definition oder ein standardisierter methodischer Rahmen. Das Ziel dieser Arbeit ist es, LCC zu charakterisieren und eine sinnvolle Methode für die Klassifizierung der vorhandenen Forschungsarbeiten zu identifizieren um methodische und inhaltliche Unterschiede darzustellen. Angewandt wird die Methodik des Literature Review, respektive einer Mischform explorativ-induktiver, qualitativer und quantitativer Inhaltsanalyse. Den Prozess der Charakterisierung und Systematisierung leiten folgende Fragestellungen: Was sind die Motivatoren der Anwendung von LCC in Firmen? Gibt es ein standardisiertes Konzept analog zur Ökobilanz (LCA)? Was sind die wesentlichen Vorteile von LCC? Was ist momentan unbefriedigend erforscht? Wo und in welcher Form wird LCC angewandt? Ergeben sich aus F-1 bis F-4 spezifische Anwendungsbereiche? Zu Beginn erfolgt im Sinne der Vision des Life Cycle Thinking eine Erörterung möglicher Motivationen einer Zuwendung zu LCC aus unternehmerischer Entscheidungsperspektive. Dem folgt eine umfangreiche Analyse und Diskussion der wesentlichen Charakterzüge. Ausgehend dieser Erkenntnis ist ein Analyseraster abgeleitet um die zu bewertenden Studien geeignet zu kategorisieren. Ein direktes Ergebnis stellt die Evaluierung von 34 Studien zu LCC dar. Als mittelbare Ergebnisse der Systematisierung gelten die Erkenntnisse zur Wahl einer optimierten Suchstrategie und die Schaffung eines Startpunkts für Forscher, die sich zukünftig mit Detailfragen des LCC beschäftigen.
218

Life Cycle Analysis and Life Cycle Cost Assessmentof a Single-family house Energy Renovation : Case study Växjö, Sweden

Abou Ghadir, Mohammed, Aghaei, Zahra January 2022 (has links)
Humans are increasingly influencing the climate and the temperature of the Earth by burning fossilfuels, destroying forests, and raising livestock. This adds massive amounts of greenhouse gases(GHG) to those already present in the atmosphere, amplifying the greenhouse effect andcontributing to global warming. The building sector accounts for a significant amount ofgreenhouse gas emissions. Decarbonizing the building industry can result in significant emissionreductions in the future years. Sweden's energy and climate goals have been updated, and some ofthem include reducing GHG emissions in the building sector, increasing energy efficiency, andmaking electricity production 100 percent renewable. In Sweden, energy renovations in singlefamily houses (SFHs) have the potential to reduce GHG emissions and improve energy efficiency,but the rate of energy renovations remains low because of financial, social, and behavioral barriers.This thesis aims to use LCA and LCC methodologies to assess energy renovations on SFH inVäxjö by combining various combinations of energy efficiency measures (EEMs) to reduce energyuse. The energy performance and eight different renovation scenarios using different EEMs havebeen evaluated for the selected single-family building. To evaluate building renovation measures,we developed a method based on life cycle assessment (LCA) and life cycle cost (LCC) thatincorporates building information modeling (BIM). Five different renovation measures werecombined in eight scenarios in this research, including different thicknesses of thermal insulationfor walls and roofs, triple-glazed windows, and doors with different U-values, air-source heatpumps, mechanical ventilation with heat recovery, and solar photovoltaic. The present cost valuesof renovation measures over 50 years for LCC calculation were calculated. The global warmingpotential (GWP) of each renovation measure was estimated over 50 years using One-click LCA.According to the findings of this thesis project, scenarios 1 and 8 had the lowest and highestreductions in primary energy number, respectively. Scenarios 5, 6, 7, and 8 are the most costeffective in comparison to other scenarios. All scenarios resulted in a reduction in GWP impactfrom an LCA perspective in which scenario 7 resulted in the highest reduction in GWP impact.
219

LCC-analys parametrar för underhåll av inklädda tunnlar

Bascunan, Daniel January 2020 (has links)
Syftet med detta examensarbete är att undersöka och få fram underhållsparametrar för LCC-analysen (LivsCykelKostnad) av de nya inklädda tunnlarna. För arbetet har elektroniska källor använts samt intervjuer med tre yrkesverksamma från Trafikverket gällande bergtunnlar och de inklädda tunnlarna. Arbetet undersökte inte skillnaden mellan olika typer av tunnlar samt inkluderar inte utforskandet av andra länders LCC-analys parameterval. Trafikverket är en Svensk myndighet vars uppgift är att ansvara för och upprätthålla Sveriges transportsystem. Trafikverket har verksamhet inom sex områden: planering, trafik, underhåll, investering, stora projekt samt informations- och kommunikationsteknik. Huvudsakligen finns det två inklädnadssystem, fullinklädd, i vilket används antingen prefabricerad betong eller plastingjuten betong som inklädnad runt tunnel, samt halvinklädd, då en duk/membran med- eller utan sprutbetong används. Dessa inklädnadsystem har i uppgift att ta hand om vattenläckage och isbildning i tunneln. Fullinklädnad kan också användas som bärande element. En lättinklädd tunnel kan bestå av följande delar: duk/membranet, brandskydd, täckande nät, infästningsbultar och mindre delar. En fullinklädd tunnel består av antingen prefabricerad betong eller plastingjuten betong. Underhåll görs för att säkerställa den fortlöpande användningen av tunneln/anläggningen genom att åtgärda skador och fel som har uppkommit. En tunnel kan få skador på själva berget eller materialet. Underhåll av tunnlar består av flera steg. Först ut är tillståndsmätning, sedan objektplanering och sist åtgärd. En viktig del av åtgärd är trafikupphållet som uppstår när den utförs, kostnaden som uppstår påverkas av var tunneln är och hur länge det tar att åtgärda felet. LCC-analys är ett system som ger ett mått på ett objekts totalkostnad under dess hela livstid. LCC används på systemnivå för analys av tunnlarna och för att jämföra olika investeringsmetoder. För att utföra LCC-analys på systemnivå måste gränser för analysen sättas upp, LCC-modell och indata väljas. LCC-metoden som redovisas i rapporten använder investeringskostnaden och nuvärdet av underhållet- samt driftstoppskostnaden för att få fram LCC-värdet av underhållet för en komponent. Utifrån källorna och intervjuerna har det framgått att de avgörande parametrarna för LLC-analysen är följande: bergets tillstånd, materialets/konstruktionens tillstånd, kostnader för avstängning samt kostnaden för att ta ner inklädnaden.
220

Ballast eller ballastfritt, det är frågan : Modellförslag för icke–monetär nyttovärdering av två olika järnvägskonstruktioner

Persson, Madeleine January 2020 (has links)
To cut transport carbon dioxide emissions by 70% by the year of 2030, the Swedish government is investing in new railway infrastructure, hoping to stem the emissions caused by the transport sector. It is planned to stretch between Stockholm–Malmö and Stockholm–Gothenburg. The first section Ostlänken, is located between Järna in Södertälje municipality (Stockholm) and Linköping. It will be a 160 kilometers long railway with double track in ballast. All railways in Sweden are built with ballast, but internationally, ballast–free methods, so called slab tracks, are increasing in popularity. This master thesis aims to compare ballast tracks with a general model of slab tracks, in regard to carbon dioxide emissions. The study also aims to evaluate how several criteria can be compared to each other as non-monetary, in an evaluation model. Three criterions will be considered: availability, economic costs and carbon dioxide emissions. A case study of Ostlänken was used as a methodological framework. Further, a literature review has been implemented as well as several interviews. Calculations of carbon dioxide emissions from the two tracks respectively were performed through a life cycle analysis (LCA). Through a multicriteria analyse, the three criteria were evaluated in respect of each other. All calculations were performed in Excel. The result that could be drawn from the study, was that from a carbon dioxide point of view, ballast tracks have a much greater need for maintenance to preserve the track geometry. Slab track on the other hand, generate higher emissions in the start of the life cycle, due to its large amount of concrete and steel. Multicriteria analysis were shown to be a helpful tool when making decisions in complex systems. The multicriteria analysis could benefit from including other case specific factors as well. This might however also lead to a far too complex model, from which fewer conclusions can be drawn.

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