Significant interior noise and vibrations in aircraft cabins are generated by the turbulent flow over the fuselage. The turbulent boundary layer (TBL) excitation is the most important noise source for jet powered aircraft during cruise flight. Reduced levels of interior noise are desirable both for comfort and health reasons. However, to efficiently design noise control systems, and to design new and optimized structures that are more efficient in the noise reduction, a clearer understanding of the sound radiation and transmission mechanisms is crucial. This task is far from being straightforward, mainly due to the complexity of the system consisted by the aircraft fuselage, and all the sound transmission mechanisms involved in a such complex environment. The present work aims to give a contribution for the understanding of these mechanisms. For that, a coupled aero-vibro-acoustic analytical model for the prediction of the TBL-induced noise and vibration in aircraft is developed. Closed form analytical expressions are obtained to predict the structural vibration levels, noise radiated from the structure and interior sound pressure levels. / Graduate

published_or_final_version / Chemistry / Master / Master of Philosophy

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Nurses who work with people who use drugs in the Downtown Eastside of Vancouver (DTES), British Columbia are on the forefront in advancing a harm reduction framework in very controversial, cutting-edge practice environments. The purpose of this study was to explore how these nurses, using the framework of harm reduction, make sense of their nursing practice. It is hoped that the results of this study may advance adopting a harm reduction framework in nursing practice, education and policy development and serve as the foundation for further nursing research. This study utilized a qualitative interpretive descriptive methodology to gather data from eight nurses who work with people who use drugs in harm reduction practice environments. The nurses were divided into two focus groups and data was collected through a semi-structured focus group interview. Following initial data analysis, each focus group was reconvened and a second semi-structured group interview was held to clarify and to further discuss the emerging themes. The data analysis proceeded simultaneously with the interviews utilizing a process of constant comparative analysis. I completed the thematic analysis as I moved between the transcripts and identified commonalties and variations within the emerging themes. Ultimately, I described one overarching theme, which encapsulated the range of experiences described by the nurses. The theme that I identified was: meeting people where they are at. The importance to the nurses of both the therapeutic nurse-client relationship and a commitment to praxis were apparent. In conclusion, the value the nurses placed on "meeting people where they are at" was integral in gaining an understanding of how they make sense of their nursing work.

Despite thirty published evaluation reports citing the effectiveness of Vancouver’s safe injection site (Small 2008), the Canadian federal government refuses to endorse safe injection sites as a health service option available to injection drug users (IDUs). Insite’ s evaluation results are undergoing debate, because two communicative spheres of knowledge, each with a unique authoritative language, are conflicting as each is attempting to gain moral authority over the right to recontextualize drug users. Drawing on a literature review of two harm reduction programs in Vancouver, Insite and Sheway, and expert interviews with evaluators, I show that what constitutes “evidence” is in fact subjective, determined by spheres of communicability that are built upon social, professional and political contexts. To confront the problematic nature of this issue, I suggest that evaluators and overseers need to treat program evaluation as a process of negotiation, best approached in a fluid manner. By obscuring multiple user experiences in the evaluation of harm reduction programs, evaluators and overseers risk imposing their communicative ideologies on what it means to be a drug user.

Biomass from forestry and agricultural sources has recently drawn a lot of attention as a new source of feedstock for energy and bio products. Size reduction is an important step in preparation of biomass as a feedstock. Each conversion process needs its own specific size or size distribution of particles. Modeling the size reduction process helps to optimize the design and control of the process while ensuring biomass particle sizes for an efficient biofuel conversion process. The objective of this study was to apply the population balance method for modeling the size reduction process. The model was applied to switchgrass size reduction by a grinder. Two population balance parameters, grinding rate (s⁻¹) and breakage distribution function (dimensionless) were estimated using experimental grinding data. The time dependent balance equations were solved using the Euler technique. The accumulation and depletion of the particles belonging to each size category were simulated as a function of time. The simulation predicted the residence time of particles inside the grinder in a way that the ground particles could meet the size and size distribution specifications for the downstream process. The thesis also describes preliminary steps in size reduction. Ground particles were fractionated based on their size by sieving. Weibull distribution was found to be the best probability density function to fit the data.

This job point was make a computer program, by Pakstiene (Lithuania) and Solheim (Norway) method. Only by WET observed you could set comperable stars spectral classes, when are known programmable stars spectral class, and score extinction.

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