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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.
151

Vliv typu atomizačního média na kvalitu spalování kapalných paliv / The influence of atomizing media on the quality of the combustion of liquid fuels

Bojanovský, Jiří Unknown Date (has links)
The aim of the present work was to experimentally investigate the influence of atomizing medium on combustion properties of methyl-ester of rapeseed oil. The experiments were carried out in a water-cooled horizontal combustion chamber. The pneumatic atomization using effervescent atomizer was used in test. As atomizing medium compressed air and superheated steam was chosen. The tests were performed at GLR = 15, 20 and 25 %. The experiments were focused on the investigation of the flame characteristics, quality of combustion, emissions, temperature of flue gas, distribution of heat fluxes and stability of combustion. Results revealed that atomization by compressed air is more efficient (approximately by 6 %), on the other hand it leads to higher NO emissions (for 13 mg/mN3 due to higher in-flame temperature).
152

Analýza dopadu dotačního programu na životní prostředí / Analysis of environmental subsidy and its environmental impact

Alferiová, Diana January 2009 (has links)
Efficiency of subsidies which aim at improving of environment quality in Czech Republic we evaluate through the use of regressive analysis and we pursue dependence between environmental protection government expenditures in Euro per capita and % of GDP in years 1996 -- 2008 and total greenhouse gas emissions of selected countries of EU in years 1998 -- 2008. The results show us that expenditures of GDP are better index for efficiency evaluation of subsidies, which confirms the importance of economic performance, though I supposed that expenditures in Euro per capita have more significant part.
153

Identification de sources acoustiques au passage d'un véhicule routier par imagerie acoustique parcimonieuse dans le domaine temporel / Identification of acoustic sources in a road vehicle pass-by situation with a sparse time-domain acoustic imaging method

Cousson, Rémi 14 December 2018 (has links)
Le présent travail de recherche s'inscrit dans le cadre de la caractérisation de l'émission de bruit des véhicules routiers. On désire identifier les sources de bruit d'un véhicule en mouvement, lors de son passage sur une voie de circulation en conditions réelles, à partir de mesures acoustiques effectuées à poste fixe en bord de voie. Les méthodes d'imagerie acoustique utilisées actuellement présentent des performances insuffisantes sur véhicules routiers. Un état de l'art a permis d’identifier une méthode existante, MSA-PSF, consistant à effectuer sous certaines hypothèses une déconvolution sur sources mobiles dans le domaine fréquentiel, et originellement utilisée en aéronautique. Cette méthode est ici adaptée au contexte des véhicules routiers. Dans un deuxième temps, une approche originale est introduite pour répondre spécifiquement aux contraintes de ce contexte : CLEANT. Il s’agit d’une méthode itérative, dans le domaine temporel avec une approche large bande, qui prend en compte les effets du déplacement des sources et qui comporte deux paramètres permettant d’affiner les résultats : le facteur de boucle et le critère d’arrêt. Une version filtrée en fréquence est également proposée et montre une amélioration de l’identification de sources secondaires dans certains cas. CLEANT présente l’avantage d’obtenir des signaux-sources temporels reconstruits, ouvrant la voie à d’autres analyses, en particulier l’utilisation de la cohérence avec des signaux issus de mesures embarquées pour la séparation des contributions de sources décorrélées. MSA-PSF et CLEANT sont évaluées sur des simulations numériques à l'aide d'indicateurs mesurant leurs performances sur les aspects localisation et quantification de sources. Elles sont par la suite testées expérimentalement en conditions contrôlées de laboratoire, par l'utilisation d'une source mobile. Cette expérience permet une première application à un cas pratique, impliquant un mouvement linéaire, la présence de deux sources simultanées et des signaux de différentes natures (tonale et large bande). Enfin, elles sont comparées à l’approche classique de formation de voies sur source mobile, dans le cadre d’une expérience avec véhicule en conditions réelles. L'approche originale CLEANT fournit des résultats très encourageants, représentant une amélioration de la formation de voies classique, notamment en basse fréquence sur les cas testés. L'application à un véhicule en conditions réelles illustre certains comportements potentiellement problématiques de CLEANT et les solutions apportées par sa version filtrée en fréquence ou par l'ajustement de ses différents paramètres. Un premier test des approches par référencement avec des signaux issus de mesures embarquées est également présenté pour discriminer l'origine physique des sources, et souligne l'incidence de la brièveté des signaux inhérente au contexte de sources au passage. / The study detailed in this manuscript is part of the effort to characterize the noise emission from road vehicles. We wish to identify the noise sources of a moving vehicle, when driven on a roadway in real-world conditions, with roadside acoustic measurements. The current acoustic imaging methods do not provide sufficient performance on road vehicles. A state of the art led to the selection of an existing method, MSA-PSF, which consists in deconvolving signals from mobile sources in the frequency domain under certain assumptions, and was originally developed for aeroacoustics. This method is adapted here to the context of road vehicles. Then, an original approach is proposed in order to tackle the specific constraints of this context: CLEANT. This is an iterative method, performed in time domain with a wideband approach, which takes into account the effect of sources motion and includes two parameters designed to refine the result: the loop factor and the stopping criterium. A further version of the algorithm, including a frequency filter, is also proposed and shows significant improvement in identifying secondary sources in some particular cases. An interesting point of CLEANT is the availability of the sources reconstructed time signals, which enables other types of analysis, especially the use of the coherence with signals from on-board measurements in order to separate the contributions of uncorrelated sources. MSA-PSF and CLEANT are evaluated with numerical simulations and a set of indicators to measure their source localization and quantification performance. They are then tested in a controlled laboratory conditions experiment, using a moving source. This experiment represents a first application of the methods to a practical case, involving a linear motion, two simultaneous sources and different kinds of signals (tone and wideband). They are finally compared to the classical approach of moving source beamforming, within the frame of an experiment on a road vehicle, in real-world conditions. The original approach CLEANT yields very encouraging results, and is a clear improvement from the conventional beamforming, especially at low frequency for the tested cases. Applying it to a road vehicle in real-world conditions highlights a potentially troublesome behavior of the method, and the solution brought by CLEANT's frequency filtered version, or by adapting its various parameters. The coherence with reference signals to discriminate the physical origins of the sources is also tested and underlines the role of the short duration of the signals related to the sources passing-by context.
154

Accounting for carbon in the FTSE100 : numbers, narratives and credibility

Malamatenios, John January 2015 (has links)
The United Kingdom Government has mandated ambitious carbon objectives, requiring an 80% reduction in emissions by 2050, and a 20% interim reduction by 2020. Their achievement will require government and large companies to work together, and for each to be assured of the other’s strategic intent. An emergent carbon accounting can provide reassurance if it produces credible information that supports the claims made by each party. This thesis investigates the extent to which carbon reduction narratives are supported or contradicted by actual carbon emissions disclosed in corporate accounting reports. It also investigates whether large corporations have delivered absolute carbon reductions in support of the government’s legally binding objectives. As a result of these and other investigations, the thesis contributes to the carbon accounting literature by critiquing the method of framing emissions employed by the Greenhouse Gas Protocol, the extent to which carbon reduction is supported by meaningful managerial incentives and the means by which analysts might rebalance financial return with carbon risk in portfolio construction. Following a middle ground approach, the research employs a numbers and narratives analysis in which critical alternative narratives are created at national, sectoral and firm levels. The analysis disaggregates macro carbon emissions data, and considers carbon emissions at a corporate meso and micro level. Narratives constituted out of these numbers, together with counter-narratives generated from corporate disclosures, are then evaluated to assess their credibility. The thesis adopts a practical approach, utilising multiple framing devices. In addition to reporting scopes 1, 2 and 3 carbon emissions, it describes a business model framework in which firms are expected to disclose their carbon-material stakeholder relations. Further recommendations are aimed at aligning the interests of corporate managers, investors and financial analysts with government carbon policy in order to modify behaviour and reduce emissions trajectories towards a lower carbon future.
155

Benchmarking the energy use of historic dwellings in Bath and the role for retrofit and LZC technologies to reduce CO2 emissions

Moran, Francis January 2013 (has links)
Historic dwellings in the UK make up 20% of all homes and are amongst the most poorly performing part of the English housing stock in energy use terms, with the lowest SAP rating and highest average annual CO2 emissions. The degree to which proposals to retrofit the UK housing stock can reduce emissions depends on current energy use and CO2 emissions. Current methodology relies on national aggregated statistics to provide average energy use data; historic buildings as a subset cannot be segregated. In order to assess realistic carbon reduction potential it is vital that performance of historic dwellings is established from disaggregated data sources or with validated and stakeholder accepted models that can accurately prescribe energy use in an affordable, easy to use and transparent manner. This research attempts to begin such orthodoxy. The benchmark derived in this study suggests that historic buildings in Bath use less energy than predicted by national, regional, and local average energy use, but they are not low energy dwellings. They therefore require retrofit adaptations to reduce CO2 emissions. Procedures to assess the potential for such measures are of primary importance as some adaptations impact on both fabric and aesthetics. It is therefore imperative that the contribution such alterations make towards reducing CO2 emissions can be weighed against the change they may make to our built heritage. Using the Passive House Planning Package modelling tool, predictions of energy use were provided and validated against actual energy use. The model demonstrated accuracy in predicting energy used when incorporating a reduction factor to reflect intermittent heating patterns. The model was then used to assess the retrofit adaptation measures with a suite of measures incorporating renewable energy technology, delivering CO2 emission reductions approaching 80%. This approach can be applied beyond the UK as the model permits the use of local weather data sets. In establishing a benchmark of energy use in domestic historic dwellings, this work assists in developing suitable and effective solutions that are replicable and durable, permitting built heritage to meet UK emissions targets through the provision of empirical data to evaluate any alteration to fabric or aesthetics against the benefit of carbon savings.
156

Spoplatnenie cestnej dopravy v Londýne / Charging for road transport in London

Koscelník, Štefan January 2011 (has links)
The aim of this work is to describe and evaluate the project of road charging in London. The theoretical part deals the issue of transport in urban conditions, its basic types, problems and possible approaches to tackling it. It also includes a description of the electronic toll systems as tools used to manage traffic in the city. The practical part deals with the use of video detection technology for road charging in London. It includes the preparation and implementation of the project, its basic principles of operation and adjustments made during the period of its operation. Followed by evaluation of the project in terms of impact on traffic, business and air quality in London. At the end of the work there are some recommendations for possible implementation of a similar charging system in terms of the city of Prague.
157

Modeling Returns on Carbon Emission Allowances: An Application to RGGI

Keneally, James 01 January 2019 (has links)
This thesis attempts to model the returns on Regional Greenhouse Gas Initiative (RGGI) allowances using logged monthly returns from 2011-2018. This asset, shown to be a useful diversifier in portfolios, has been identified by previous literature to behave similarly to commodities. I used auto-regressive, GARCH, and Markov regime switching models to analyze the returns because the returns displayed changing volatility. These models were comparatively analyzed both in and out-of-sample. In this limited data analysis, the Markov model outperformed both alternatives in-sample. The Markov and Garch models displayed similar predictive power out-of-sample, however neither were particularly effective.
158

Inter-pollutant and reactivity-weighted air pollutant emission trading in Texas

Wang, Linlin, January 1900 (has links) (PDF)
Thesis (Ph. D.)--University of Texas at Austin, 2006. / Vita. Includes bibliographical references.
159

The development of Comprehensive Community NOx Emissions Reduction Toolkit (CCNERT)

Sung, Yong Hoon 15 November 2004 (has links)
In this dissertation I will present and test a model linking actual applicant-interviewer demographic, human capital, and cultural capital similarity to an interviewer's recommendation to hire. Actual similarity is proposed to influence an interviewer's perceptions of similarity with an applicant. These perceptions, in turn, lead to the interviewer's perceptions of the applicant's Person-Organization (PO) fit and the applicant's Person-Job (PJ) fit. Two main mechanisms are proposed to mediate the relationship between an interviewer's perceptions of similarity and an interviewer's perceptions of an applicant's fit: liking and negative behavioral expectations. Lastly, both an interviewer's PO and PJ fit perceptions of an applicant are posited to influence the interviewer's recommendation to hire. A total of 118 interviewer-applicant dyads contacted through the Career Center Office at a University located in the southwestern United States participated in the study. Results partially support the model. An interviewer's perceptions of similarity with an applicant are positively related to an interviewer's fit evaluations. An interviewer's negative behavioral expectations of an applicant mediate this relationship. Furthermore, perceived similarity is positively related to an interviewer's liking of an applicant. In turn, liking is positively related to an interviewer's PO fit perceptions. However, liking does not function as a mediator between perceived similarity and fit evaluations. Finally, fit evaluations are positively related to hiring recommendations. I discuss the main implications of the study as well as strengths, limitations, and future research.
160

Grönt resande : En studie om hur företag arbetar med klimatkompensation

Karadag, Yeliz, Rickman, Marita January 2010 (has links)
Carbon offsetting means to offset those greenhouse gases that are caused by our actions. The purpose of this paper is to examine how companies are working with carbon offsetting. The focus of the research is how travel agencies and companies that provides carbon offsetting. The writers also highlight the problems carbon offsetting is facing. The study was performed with qualitative methods through interviews with three companies working with carbon offsetting. The research shows that carbon offsetting within air travel can vary in price between different companies and they find it more lucrative to work with business customers. The writers have come to the conclusion that it is people's attitudes as well as lack of promotion and information that is the problem that exists for carbon offsetting. The writers have also found out that it is the uncertainty about carbon offsetting that affects the individual's attitude towards the subject. This, as well as the awareness that exists about the subject and the economy which every individual is prepared to spend on the environment.

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