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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.
11

The Influence of Elliptical Nozzle Holes on Mixing and Combustion in Direct Injection Natural Gas Engines

Wager, David 26 February 2009 (has links)
Experiments were conducted to compare mixing and combustion of natural gas jets from round and elliptical nozzle holes in an optically accessible combustion bomb. A flame ionization detector was used to measure the concentration fields of the two jet types. Pressure data, combustion imaging, and hydrocarbon measurements of exhaust gas were used to compare the ignition delay, heat release, and combustion efficiency of the two nozzles. Concentration measurements indicated that the elliptical nozzle produced jets with smaller rich core regions and lower peak concentrations at all conditions. Firing tests indicated that the two nozzles produced equivalent ignition delays. Peak heat release rates were higher for the round nozzle, while the elliptical nozzle produced smoother transitions from premixed to diffusion burning. Combustion efficiency was slightly higher for the round nozzle. Results indicate that elliptical nozzles could potentially lower NOx and particulate emissions, but further experiments are required to test this hypothesis.
12

The Influence of Elliptical Nozzle Holes on Mixing and Combustion in Direct Injection Natural Gas Engines

Wager, David 26 February 2009 (has links)
Experiments were conducted to compare mixing and combustion of natural gas jets from round and elliptical nozzle holes in an optically accessible combustion bomb. A flame ionization detector was used to measure the concentration fields of the two jet types. Pressure data, combustion imaging, and hydrocarbon measurements of exhaust gas were used to compare the ignition delay, heat release, and combustion efficiency of the two nozzles. Concentration measurements indicated that the elliptical nozzle produced jets with smaller rich core regions and lower peak concentrations at all conditions. Firing tests indicated that the two nozzles produced equivalent ignition delays. Peak heat release rates were higher for the round nozzle, while the elliptical nozzle produced smoother transitions from premixed to diffusion burning. Combustion efficiency was slightly higher for the round nozzle. Results indicate that elliptical nozzles could potentially lower NOx and particulate emissions, but further experiments are required to test this hypothesis.
13

A Bass Diffusion Model Analysis: Understanding Alternative Fuel Vehicle Sales

Shoemaker, Michael H. 01 January 2012 (has links)
Frank M. Bass developed the Bass Diffusion Model to predict how innovative consumer durable products diffuse through consumer markets. This thesis will use data from 1999-2011 to examine the applicability of the Bass Diffusion Model to the introduction of alternative fuel vehicles (AFVs) in the automobile market. The findings in this thesis indicate the Bass Diffusion Model fit the diffusion pattern exhibited by AFVs well, but failed to accurately forecast diffusion patterns outside a given range of data. This thesis investigates potential reasons for the inaccurate 'Out of Sample Forecast', and gives recommendations for directions of future research on AFV diffusion.
14

What happens when we have no more crude oil?

Adenfelt, Elin January 2004 (has links)
No description available.
15

Combustion characteristics and in-cylinder process of CAI combustion with alcohol fuels

Tongroon, Manida January 2010 (has links)
Controlled auto-ignition (CAI) combustion in the gasoline engine has been extensively studied in the last several years due to its potential for simultaneous improvement in fuel consumption and exhaust emissions. At the same time, there has been increasing interest in the use of alternative fuels in order to reduce reliance on conventional fossil fuels. Therefore, this study has been carried out to investigate the effect of alcohol fuels on the combustion characteristics and in-cylinder processes of CAI combustion in a single cylinder gasoline engine. In order to study the effect of alcohol fuels, combustion characteristics were investigated by heat releases analysis in the first part. The combustion process was studied through flame structure and excited molecule by chemiluminescence imaging. Furthermore, in-cylinder gas composition was analysis by GC-MS to identify the auto-ignition reactions involved in the CAI combustion. In addition, the influence of spark-assisted ignition and injection timings were also studied. Alcohol fuels, in particular methanol, resulted in advanced auto-ignition and faster combustion than that of gasoline. In addition, their use could lead to substantially lower HC, NOX and CO exhaust emissions. Spark-assisted ignition assisted gasoline combustion by advancing ignition timing and initiating flame kernel at the centre of combustion chamber but it had marginal effect on alcohol fuels. Auto-ignition always took place at the perimeter of the chamber and occurred earlier with alcohol fuels. Fuel reforming reactions during the NVO period were observed and they had significant effect on alcohol combustion.
16

Analysis and control of an in situ hydrogen generation and fuel cell power system for automotive applications

Kolavennu, Panini K. Palanki, Srinivas. January 2006 (has links)
Thesis (Ph. D.)--Florida State University, 2006. / Advisor: Srinivas Palanki, Florida State University, FAMU-FSU College of Engineering, Dept. of Chemical Engineering. Title and description from dissertation home page (viewed June 8, 2006). Document formatted into pages; contains xi, 145 pages. Includes bibliographical references.
17

Consumers’ Willingness to Pay for Alternative Fueled Rental Cars : A Choice Experiment Study in Luleå, Sweden

Björklund, Emma January 2018 (has links)
Sweden, as a country, has set the goal to achieve a fossil independent vehicle fleet by 2030, which means that Sweden has to reduce its CO2 emissions by 80 percent. Sources argue that the regulations and different implementations that have been done are not enough to reach the 80 percent reduction in time. The purpose of this paper is to analyze consumers’ preferences towards alternative fuel vehicles by estimating the willingness to pay for rental cars in Sweden. The paper also tries to define the explanatory factors for choosing an alternative fuel vehicle. The data used in this thesis was collected through a choice experiment questionnaire that was distributed to employees and students at Luleå University of Technology. The study concludes that respondents have a willingness to pay at approximately SEK 280 extra to rent and use an electric rental car.
18

Modulation of Catalyst@MOF Host-Guest Composites in Pursuit of Synthetic Artificial Enzymes:

Rayder, Thomas M. January 2020 (has links)
Thesis advisor: Jeffery A. Byers / Thesis advisor: Chia-Kuang (Frank) Tsung / Biological systems have evolved over time to favor structures beneficial for the efficient transformation of simple feedstocks to sophisticated products. In particular, enzymes have evolved such that cooperative and geometrically controlled interactions between active sites and substrates enhance catalytic activity and selectivity. Separation of these active sites from other incompatible catalytic components allows for chemical transformation in a stepwise fashion, circumventing the inherent limitations to performing reactions in a single step. This dissertation describes the use of porous crystalline materials called metal-organic frameworks (MOFs) as hosts to mimic the component separation and precise active site control observed in nature. The first phase of these efforts explores the use of dissociative “aperture-opening” linker exchange pathways in a MOF to encapsulate transition metal complexes for carbon dioxide hydrogenation to formate. This strategy is then used to separate two incompatible complexes and perform the cascade conversion of carbon dioxide to methanol, resulting in unique and previously unobserved network autocatalytic behavior. Finally, the modularity of the MOF host is leveraged to install beneficial functionality in close proximity to the encapsulated transition metal complex, leading to activity exceeding that of any reported homogeneous system for carbon dioxide reduction. The insights gained through these studies can inform the development of composites for other reactions, allowing for access to new and unique reaction manifolds. / Thesis (PhD) — Boston College, 2020. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.
19

Bioetanol pro pohon automobilu / Bioetanol and Drive of Automobile

Smeták, Pavel January 2010 (has links)
Content of my diploma thesis focuses on identification of properties and usability of nascent fuel for automotive use. It is a bio-ethanol which can be produced from renewable sources. The heart of this work is to develop methodology of experimental trials in connection with utilization of bio-ethanol E85 as a fuel for vehicle combustion engines. The aim is to perform tests with E85 and BA95 fuels in engine testing room of ÚADI FSI, to compare these trials amongst themselves and to analyze obtained results. Subsequent part of diploma thesis covers overview of general usage of bio-ethanol in road transportation.
20

The Challenges of Biofuels in Ohio: From the Perspective of Small-Scale Producers

McHenry, John Carl Izaak 28 April 2008 (has links)
No description available.

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