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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.
61

Retardance coefficients and other data for a vegetated irrigation border

Atchison, Kenneth Tella, 1944- January 1973 (has links)
No description available.
62

F-Note Acoustic Efficiency of an Upright Piano over Seven Octaves

Bang, Seok Jae 13 May 2009 (has links)
Pianos are machines. Their sound output is determined by acoustic efficiency which is a measure of acoustic energy produced per input mechanical work. The piano as an instrument is unique from other chordophones like violins and guitars as it uses hammers to cause string vibrations. Where work is done directly on the strings in a guitar, pianos utilize a two-step procedure in converting mechanical work into acoustic energy. First, mechanical energy is used to depress a piano key which lifts a hammer. Second, this hammer strikes the strings and acoustic energy is produced. Thus, pianos should be less efficient than strict chordophones. An index of acoustic efficiency as a function of frequency was generated using an F-note from each of the seven full octaves of a Yamaha upright piano (T118PE). Experimental results indicate an inversely proportional relationship between acoustic efficiency and key frequency.
63

Barriers and opportunities for improving energy efficiency in the social housing sector : case study of E4C's division of housing and mental health

Marchand-Smith, Patrick 18 December 2012 (has links)
Energy efficiency improvements in the social housing sector have the potential to produce a range of environmental and social benefits. These improvements can be produced through retrofits that deliver energy savings or new construction built to a high standard of energetic efficiency. However, implementation of these approaches is hindered by economic and organizational constraints affecting the agencies that provide society with social housing and the governments that support the provision of these services. This thesis builds on the work of other researchers studying these constraints by supplying an in-depth case study from Alberta and a discussion based on its findings. The case study focuses on E4C, a social service agency with several housing projects. Overall, findings matched important themes identified in the academic literature. The in-depth nature of the case study added additional insight to many of these themes. Most barriers are economic in nature and related to a lack of sufficient funding or the up-front costs of energy-saving retrofits. The recommendations presented are based on consideration of the multiple barriers and opportunities faced. Most of these require a considerable investment of time on the part of agencies and would be followed up by capital investments to implement energy-saving changes. Therefore it is important to note that the most significant barrier is commitment, which is one of E4C's central values. This thesis showed that commitment cannot exceed capacity to act. Greater commitment on the part of governments, agencies or society at large could have significant impacts in improving the energy efficiency of buildings in the Albertan, and Canadian, social housing sector.
64

Response organization and time-sharing in dual-task performance

Folds, D. (Dennis) 05 1900 (has links)
No description available.
65

Rumen Methanogenic Ecology under Different Diets and Cattle Feed Efficiency

Zhou, Mi Unknown Date
No description available.
66

The feasibility of waste heat recovery and energy efficiency assessment in a steel plant

Si, Minxing 20 July 2011 (has links)
Gerdau Manitoba Mill (Gerdau) at Selkirk, Manitoba is one of the biggest energy consumers in the province of Manitoba. This research analysis undertaken at Gerdau evaluated opportunities for energy efficiency, including the following six areas: 1) recovering waste heat to preheat billets, 2) upgrading the charge end in the reheat furnace, 3) recovering waste heat to preheat combustion air in the ladle preheater, 4) replacing direct-fired natural gas heaters with indirect-fired natural gas heaters, 5) Oxyfuel combustion, and 6) “tap to tap time” control in the eccentric bottom tapping (EBT) furnace in the melt shop. As part of this research, end-user distribution was analyzed and energy losses were assessed. An end-use analysis found that the melt shop that includes the EBT furnace is the biggest consumer of electricity consumption (kWh) and electric demand (kVa), which accounted for 68.7% and 73.6 % respectively. The 2010 delay time in the power-off time of EBT furnace at Gerdau was found to be 762.3 hr/yr. Further research to analyze the cause of each downtime at Gerdau is recommended to determine how these unplanned downtime can be reduced in the EBT furnace. The reheat furnace is the biggest natural gas consumer at Gerdau with 437,563 MCF in 2010. Flue gas losses from the reheat furnace are the biggest energy losses in the gross heat distribution with 26,874,657 Btu/hr. Energy losses from hearth and roof by heat transmission are the biggest energy losses in the net heat distribution during operation, which accounted for 8.9%. The average thermal efficiency in the reheat furnace at Gerdau is 58.9% ± 3.6%. Compared to peak capacity, idle and partial operations of the reheat furnace and idling were found to be less efficient. The opportunities that are considered feasible and recommended to Gerdau are: 1) recovering waste heat to preheat billets, 2) upgrading the charge end in the reheat furnace, 3) recovering waste heat to preheat combustion air in the ladle preheater, 4) replacing direct-fired natural gas heaters with indirect-fired natural gas heaters. These are both good for the environment, reducing fuel use and emissions and providing a good payback period and annual savings. Many opportunities are available for reducing energy as provided in Table A, which shows emissions reductions, costs, energy savings and payback. Oxyfuel combustion is not deemed feasible without considering productivity improvement as oxygen cost is more than natural gas saving. A number of incentive programs, including those from Manitoba Hydro, are applicable to Gerdau. However, a number of barriers to accessing these, particularly as regards tax incentive programs, should be explored to see if these barriers can be overcome.
67

Input-output technology forecasting : A micro-foundation approach

Field, K. F. January 1985 (has links)
No description available.
68

Explaining Inefficiency in an Ontario Bail Court: Perspectives of Criminal Defence Lawyers

Grech, Diana C. 29 June 2011 (has links)
Some academics and government officials have implicated defence counsel as the primary ‘villains’ in lengthy case processing times in Ontario bail courts. It has been suggested that defence counsel contribute to increasing case processing time through their use of ‘unproductive’ adjournments. This study examines this allegation through semi-structured interviews with defence counsel who practise in one Eastern Ontario bail court. The findings put the evidence that blames defence counsel into context and show that the explanations for their conduct are more complex than they may initially appear. They also reveal several explanations for bail inefficiency which are unrelated to the role of defence counsel but correspond grosso modo to the traditional factors associated with lengthy case processing time in the broader court process. The study concludes that although defence counsel are partly responsible for lengthy case processing times in bail court, they are only one contributor among many others.
69

The feasibility of waste heat recovery and energy efficiency assessment in a steel plant

Si, Minxing 20 July 2011 (has links)
Gerdau Manitoba Mill (Gerdau) at Selkirk, Manitoba is one of the biggest energy consumers in the province of Manitoba. This research analysis undertaken at Gerdau evaluated opportunities for energy efficiency, including the following six areas: 1) recovering waste heat to preheat billets, 2) upgrading the charge end in the reheat furnace, 3) recovering waste heat to preheat combustion air in the ladle preheater, 4) replacing direct-fired natural gas heaters with indirect-fired natural gas heaters, 5) Oxyfuel combustion, and 6) “tap to tap time” control in the eccentric bottom tapping (EBT) furnace in the melt shop. As part of this research, end-user distribution was analyzed and energy losses were assessed. An end-use analysis found that the melt shop that includes the EBT furnace is the biggest consumer of electricity consumption (kWh) and electric demand (kVa), which accounted for 68.7% and 73.6 % respectively. The 2010 delay time in the power-off time of EBT furnace at Gerdau was found to be 762.3 hr/yr. Further research to analyze the cause of each downtime at Gerdau is recommended to determine how these unplanned downtime can be reduced in the EBT furnace. The reheat furnace is the biggest natural gas consumer at Gerdau with 437,563 MCF in 2010. Flue gas losses from the reheat furnace are the biggest energy losses in the gross heat distribution with 26,874,657 Btu/hr. Energy losses from hearth and roof by heat transmission are the biggest energy losses in the net heat distribution during operation, which accounted for 8.9%. The average thermal efficiency in the reheat furnace at Gerdau is 58.9% ± 3.6%. Compared to peak capacity, idle and partial operations of the reheat furnace and idling were found to be less efficient. The opportunities that are considered feasible and recommended to Gerdau are: 1) recovering waste heat to preheat billets, 2) upgrading the charge end in the reheat furnace, 3) recovering waste heat to preheat combustion air in the ladle preheater, 4) replacing direct-fired natural gas heaters with indirect-fired natural gas heaters. These are both good for the environment, reducing fuel use and emissions and providing a good payback period and annual savings. Many opportunities are available for reducing energy as provided in Table A, which shows emissions reductions, costs, energy savings and payback. Oxyfuel combustion is not deemed feasible without considering productivity improvement as oxygen cost is more than natural gas saving. A number of incentive programs, including those from Manitoba Hydro, are applicable to Gerdau. However, a number of barriers to accessing these, particularly as regards tax incentive programs, should be explored to see if these barriers can be overcome.
70

On the unconditional and conditional cross section of expected futures returns

Miffre, Joelle January 1998 (has links)
While most of the literature on asset pricing examines the cross section of stock and bond returns, little attention has been devoted to the analyse of the trade-off between risk and return in futures markets. Since, alike stocks and bonds, futures contracts qualify as investments on their own, the purpose of this thesis is to remedy this problem by addressing three issues related to the unconditional and conditional cross section of expected futures returns. Chapter II investigates the presence of a futures risk premium and, ultimately, the validity of the normal backwardation theory in the context of constant expected return asset pricing models and argues that the inconsistency in the literature stems from methodology problems that might result in incorrect inferences regarding the applicability of the normal backwardation theory. With methodologies free from these problems, we show that, while producers and processors of agricultural commodities transfer their risk to one another at no cost, hedgers are willing to pay a premium to induce speculators to enter financial and metal futures markets. Chapter III looks at the integration between the futures and underlying asset markets. While we fail to reject the hypothesis that the prices of systematic risk in futures markets are equal to those in the underlying currency and equity markets, we present new results that the futures and commodity spot markets are segmented. Such results are of primary importance to investors who use constant expected return asset pricing models to adjust the risk-return trade-off of their portfolio and evaluate portfolio performance. The remainder of the thesis investigates the degree of efficiency with which futures contracts are priced. Since futures returns are predictable using information available at time t-1, the purpose of chapters IV, V. and VI is to analyse whether the variation in expected futures returns reflects rational pricing in an efficient market or is the result of weak-form market inefficiency. In this respect, chapter IV investigates the profitability of a trading rule based on available information and concludes that the implemented investment strategy does not generate any abnormal return on a risk and transaction cost adjusted basis. Chapter V looks at the link between the time-varying futures risk premia and the economy and demonstrates that the information variables predict futures returns because of their ability to proxy for change in the business cycle. Finally, chapter VI makes use of time-varying asset pricing models to analyse the relationship between the predictable movements in futures returns and the conditional cross section of expected futures returns. The results indicate that conditional versions of asset pricing models capture most of the predictable movements in futures returns. Hence the predictability of futures returns seem to mirror the change in the consumption-investment opportunity set over time. Chapters V and VI also raise some interesting observations that have not been evidenced to date in the literature on predictability. First, the time-variation in the expected returns of currency and agricultural commodity futures is not consistent with the evidence from the stock and bond markets and with traditional theoretical explanations of the trade-off between risk and expected return. Second, chapter VI demonstrates that shift in the sensitivities of futures returns to the constant prices of covariance risk accounts for most of the predictable movements in futures returns. This result is somehow surprising since the change in the prices of risk is the main source of predictability in the stock and bond markets.

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