Construction contributes significantly to gas emissions. Diverse efforts have been undertaken to mitigate the effects of these emissions; however, there currently is no effective tool to estimate small-scale (e.g., project-based) emissions in construction. Discrete-event simulation (DES), a new approach, may be able to rectify this lack. This research has built a DES-based emission template using Simphony, a special purpose simulation (SPS) environment developed at the University of Alberta. This template permits inexperienced simulators to build simulation models that can estimate emissions of a construction project. Two case studies are used to showcase the modeling process and to demonstrate how valuable information concerning sustainability can be obtained through this method. In addition, this research introduces an emission federate in a high-level architecture (HLA) simulation environment that can estimate emissions without building models; it relies instead upon information provided by other federates (e.g., operation federate), which has been underdeveloped thus far. / Construction Engineering and Management

In this thesis various aspects of the diesel engine fuel injection, combustion and emission formation processes have been evaluated. Several types of evaluation tools and methods have been applied. Fuel spray momentum was used to characterize injection rate and hole-to-hole variations in fuel injectors. Using both instantaneous fuel impulse rates and instantaneous mass flow measurements, spray velocity and nozzle flow parameters were evaluated. Several other hole-to-hole resolved injector characterization methods were used to characterize a set of fuel injectors subjected to long term testing. Fuel injector nozzle hole-to-hole variations were found to have a large influence on engine efficiency and emissions. The degree of hole-to-hole variations for an injector has been shown to correlate well with the performance deterioration of that injector. The formation and atomization of fuel sprays, ignition onset and the development of diffusion flames were studied using an optical engine. Flame temperature evaluations have been made using two different methods. NO-formation depends strongly on flame temperature. By applying a NO-formation evaluation method based on both heat release rate and flame and gas temperature it was possible to achieve a reasonable degree of correlation with measured exhaust emissions for very varying operating conditions. The prediction capability of the NO-formation evaluation method was utilized to evaluate spatially and temporally resolved NO-formation from flame temperature distributions. This made it possible to pinpoint areas with a high degree of NO-formation. It was found that small hot zones in the flames can be responsible for a large part of the total amount of NO that is produced, especially in combustion cases where no EGR is used to lower the flame temperature. By applying optical diagnostics methods the combustion and emission formation phenomena encountered during production engine transients were evaluated. The transient strategy of the engine involved reducing the EGR-rate to zero during the initial parts of the transient. Increased general flame temperature and the occurrence of small hot zones were found to explain the increase in NO-emissions during these transients. / QC 20110530

Zugl.: Wuppertal, Univ., Diss.2007

Thesis (Ph. D.)--University of Texas at Austin, 2007. / Vita. Includes bibliographical references.

Ulm, Univ., Diss., 2007.

Thesis (M.Sc.)--University of Hong Kong, 2008. / Includes bibliographical references (p. 29-39).

Thesis (Ph. D.)--University of Washington, 1999. / Vita. Includes bibliographical references (leaves 81-89).

Sol-gel production of catalyst supports has been investigated in order to produce homogeneous, high surface area alumina/zirconia materials. A novel microwave method of preparing colloidal Pd has been developed and a range of alumina/zirconia supported Pd catalysts has been produced. These have been tested for activity in terms of temperature programmed three way catalysis (simultaneous removal of NO, CO and C3H8 from a simulated car exhaust stream) and from the array of catalysts produced a suitable catalyst was chosen for further investigation. This catalyst had a 3% zirconia / 97% alumina support and contained ~1% Pd by weight and was examined for activity in the NO + CO + O2 system at temperatures below 500°C. Temperature programmed catalytic experiments revealed the reactions to be chemically controlled below ~400°C but diffusion controlled above this. CO temperature programmed reduction was used to examine the oxidation state of the Pd and revealed a complex Pd/PdO system to be present involving bulk PdO and surface oxide. Further kinetic studies showed that the reactions between NO, CO and O2 to have positive orders in all components. The reaction rates were stable over a wide range of conditions and the NO + CO reaction proved to have a low selectivity towards N2O. In-situ DBIFTS experiments alongside transient pulse work were used to illustrate low CO adsorption which indicated that these reactions proceeded via a redox mechanism in which Pd is oxidised by NO or O2 before being reduced by CO. The support material was examined by XRD following extended heating regimes and then compared to an identically treated sol-gel alumina. The zirconia doped alumina was found to possess a far greater thermal resistance to sintering than the pure alumina material and this was attributed to Zr4+ ions preventing the diffusion of Al3+ to form a-alumina.

Thesis advisor: Christopher Maxwell / Reducing carbon dioxide emissions and strengthening the economies of developing countries are among the most pressing issues within Sustainable Development. In order to enact effective policies to move toward Sustainable Development Goals, a deep understanding of the pollution-income relationship, and how it differs between developed and developing countries, is imperative. Using advanced panel data analysis techniques, and using the IPAT and EKC models, my results find that the relationship between carbon dioxide emissions and economic development differs for developed and developing countries. Additionally, my analysis uses carbon dioxide emissions, a global pollutant, to proxy environmental quality. My results, however, oppose those of existing literature which use local pollutants as the proxy. This may suggest that the utility gained from reducing local pollutants differs from the utility gained by reducing global pollutants. Further exploration of the differing pollution-income relationship for local and global pollutants serves as an area for future research. / Thesis (BA) — Boston College, 2021. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: Departmental Honors. / Discipline: Economics.

90% of global trade is transported by cargo ships, with fossil fuel being the dominant energy source used. As global trade increases, shipping will be in greater demand resulting in increased emissions of carbon dioxide and other pollutants negatively impacting the environment and human health. Carbon dioxide (CO2), our area of interest, is the number one contributing gas to global warming. We, therefore, examine the role of the International Maritime Organization (IMO) in reducing CO2 emissions from shipping, and determine the progress made so far. Our research reveals that progress in this area is on a slow trajectory. The current IMO regulations focus solely on energy efficiency measures that do not appear to be as successful as envisioned in reducing CO2 emissions. In addition, the concept of decarbonization of the sector, which would lead to zero emissions, is delayed. With this in mind, we provide recommendations regarding future IMO actions.