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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.
41

Characterization of residual feed intake and relationships with performance, carcass and temperament traits in growing calves

Fox, James Trent 15 November 2004 (has links)
The objectives of this study were accomplished with two experiments in growing Bonsmara bulls (N = 68) (experiment 1), and Simmental crossbred calves (N = 132) (experiment 2). Specific objectives for experiment 1 were to characterize residual feed intake (RFI) in growing bulls, and examine relationships between RFI and performance, fertility, temperament and body composition traits. In experiment 2, the objectives were to examine stocker-phase supplementation effects on feedlot feed conversion ratio (FCR) and RFI and to characterize relationships between these feed efficiency traits, and performance and carcass traits in finishing calves. In both experiments, individual feed intakes and BW were measured. Ultrasound technology was used to measure body composition in experiment 1, while actual carcass measurements taken at harvest were used for experiment 2. Experiment 1 demonstrated that temperament affected ADG and DMI, but not FCR or RFI. Residual feed intake was not phenotypically correlated to scrotal circumference or bull fertility traits. Experiments 1 and 2 demonstrated that RFI was independent of ADG and BW, but that there was a tendency (P < 0.10) for RFI to be phenotypically correlated with 12th rib fat thickness (r = 0.20 and 0.22). However, RFI was not correlated with longissimus muscle area in either experiment. Both experiments demonstrated that low RFI (< 0.5 SD below mean RFI) calves consumed significantly (20 and 22%) less feed and had improved (21%) FCR compared to calves with high RFI (> 0.5 SD above mean RFI). Results from experiment 2 suggest that RFI measured while calves are consuming high-grain diets may be less influenced by previous level of stocker supplementation compared to FCR or residual gain efficiency traits. In summary, RFI was found to be phenotypically independent of growth rate and BW, had no effect on bull fertility or temperament traits, and was less impacted by previous plane of nutrition compared to FCR.
42

Feed efficiency, carcass, and temperament traits in F2 Nellore-Angus steers

Amen, Tonya Sue 10 October 2008 (has links)
Feed efficiency in fed F2 Nellore-Angus steers produced through embryo transfer was evaluated using two methods: residual feed intake (RFI) and NRC-based model predicted residual consumption (MPRC). Sire and family(sire) both contributed to differences in model predicted residual consumption (P = 0.036 and P < 0.001, respectively), but not in RFI (P = 0.117 and 0.455, respectively). This indicates that variation exists among the sires and families studied, and the opportunity exists to improve MPRC through selection; it also indicates these 2 evaluation methods could result in different conclusions about feed efficiency. Five aspects of temperament were also evaluated (aggressiveness, nervousness, flightiness, gregariousness, and overall temperament) on a 9-point scale shortly after weaning. Sire had a significant effect on all 5 aspects of temperament evaluated, but family was only responsible for variation in aggressiveness, nervousness, and overall temperament. Contemporary group had no effect on aggressiveness, but did contribute significantly to variation in all other temperament traits. All temperament traits were highly correlated with one another (r = 0.81 to 0.98). Recipient dam temperament was lowly correlated with gregariousness and overall temperament (r = 0.16 and 0.15, respectively), and the correlations with recipient dam temperament approached significance for aggressiveness, nervousness and flightiness. This suggests that the temperament of the recipient female may have a small effect on the temperament of the calf. This population was structured to identify QTL for economically important traits and appears to be useful to identify genetic markers for feed efficiency and animal temperament.
43

Feed efficiency, carcass, and temperament traits in F2 Nellore-Angus steers

Amen, Tonya Sue 15 May 2009 (has links)
Feed efficiency in fed F2 Nellore-Angus steers produced through embryo transfer was evaluated using two methods: residual feed intake (RFI) and NRC-based model predicted residual consumption (MPRC). Sire and family(sire) both contributed to differences in model predicted residual consumption (P = 0.036 and P < 0.001, respectively), but not in RFI (P = 0.117 and 0.455, respectively). This indicates that variation exists among the sires and families studied, and the opportunity exists to improve MPRC through selection; it also indicates these 2 evaluation methods could result in different conclusions about feed efficiency. Five aspects of temperament were also evaluated (aggressiveness, nervousness, flightiness, gregariousness, and overall temperament) on a 9-point scale shortly after weaning. Sire had a significant effect on all 5 aspects of temperament evaluated, but family was only responsible for variation in aggressiveness, nervousness, and overall temperament. Contemporary group had no effect on aggressiveness, but did contribute significantly to variation in all other temperament traits. All temperament traits were highly correlated with one another (r = 0.81 to 0.98). Recipient dam temperament was lowly correlated with gregariousness and overall temperament (r = 0.16 and 0.15, respectively), and the correlations with recipient dam temperament approached significance for aggressiveness, nervousness and flightiness. This suggests that the temperament of the recipient female may have a small effect on the temperament of the calf. This population was structured to identify QTL for economically important traits and appears to be useful to identify genetic markers for feed efficiency and animal temperament.
44

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.
45

Life-cycle Cost Evaluation of Building Envelope Energy Retrofits

Maleki, Afarin 17 January 2012 (has links)
Improving the energy efficiency of our existing building stock is attainable by upgrading the building envelope through carrying out various retrofit measures. The objective of this thesis is to evaluate the life-cycle cost implications of energy retrofits for existing buildings. Measures examined include improving insulation and air-tightness with overcladding strategies. The life-cycle costs of the upgrades are determined for an existing building and compared with model energy performance. A life-cycle cost evaluation for the building envelope upgrades is provided, together with the payback period and the projected return on investment (ROI) for two energy escalation rate scenarios. A costbenefit matrix for various over-cladding strategies is provided to facilitate the evaluation of each option. Further, this thesis presents a simplified ROI algorithm to enable owners, architects and engineers to evaluate the cost-benefit of their building envelope retrofit options.
46

Life-cycle Cost Evaluation of Building Envelope Energy Retrofits

Maleki, Afarin 17 January 2012 (has links)
Improving the energy efficiency of our existing building stock is attainable by upgrading the building envelope through carrying out various retrofit measures. The objective of this thesis is to evaluate the life-cycle cost implications of energy retrofits for existing buildings. Measures examined include improving insulation and air-tightness with overcladding strategies. The life-cycle costs of the upgrades are determined for an existing building and compared with model energy performance. A life-cycle cost evaluation for the building envelope upgrades is provided, together with the payback period and the projected return on investment (ROI) for two energy escalation rate scenarios. A costbenefit matrix for various over-cladding strategies is provided to facilitate the evaluation of each option. Further, this thesis presents a simplified ROI algorithm to enable owners, architects and engineers to evaluate the cost-benefit of their building envelope retrofit options.
47

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.
48

How to get things done

Schwab, Jordan Leo David 30 September 2009 (has links)
A thesis dedicated to getting things done.
49

Two-stage and Three-stage Virtual Impactor System for Bioaerosol Concentration

Wen, Jing 2009 December 1900 (has links)
The Circumferential Slot Virtual Impactor (CSVI) and The XMX/2A are two virtual impactors designed for sampling aerosol particles from a dilute environment by separating the aerosol into a fine and a coarse particle fraction. Dust particles in the ambient air may deposit within the virtual impactors and affect their performances. In this study the effect of dust loading within the CSVI on the efficiency of transmission was determined for particles from 0.49 to 9.9 mm in aerodynamic diameter (AD), and the performance of the three stage XMX/2A aerosol concentrator was characterized with 1 mm-9.9 ?m AD polystyrene latex microspheres (PSL). In the first experimental configuration, the two-stage CSVI had a first stage inflow of 100 L/min and a second stage minor flow of 1 L/min, each stage operating at an inflow/minor flow ratio of 10. An In-line Virtual Impactor (IVI) was used as a pre-separator for sampling inlets to exclude large particles. When the 100 L/min IVI with the two-stage CSVI was tested with Arizona Fine Road Dust (ARD A-2) particles, the transmission efficiency dropped to 50% when the dust entering the two-stage CSVI accumulated to about 100 mg. When it was tested with ASHRAE dust, a decrease of 43% in the efficiency was detected after more than 200mg ASHRAE dust entered the two-stage CSVI. After cleaning the CSVI unit, the transmission efficiency returned to 99%, which indicated that the dust dissemination resulted in the plugging of the CSVI unit. The transmission efficiency of CSVI dropped more quickly below 50% when tested with the ARD A-2 dust, which had smaller particle sizes. In the second configuration, XMX/2A, a three-stage aerosol concentrator designed to draw 800 L/min of air was used at a measured sampling flow rate of 742 L/min. XMX/2A equipped with an inlet was tested with 1 mm-9.9 mm AD PSL in a testing chamber. The peak transmission efficiency of XMX/2A was 39.5% for 8 mm AD PSL. By using the room air as cooling air and introducing dilution air to the flow cell, the transmission efficiency of each particle size increased. A combination of monodisperse PSL and oleic acid particles represent the performance of CSVI. In the IVI-CSVI dust test, the CSVI unit SN003 had the best performance when tested with ASHRAE dust. XMX/2A had relatively low transmission efficiency when tested with PSL particles in the chamber.
50

CFD optimization study of high-efficiency jet ejectors

Watanawanavet, Somsak 2008 May 1900 (has links)
Research was performed to optimize the high-efficiency jet ejector geometry by varying motive velocities from Mach 0.50 to 3.25, and mass flow ratio from 0.02 to 100.0. The high-efficiency jet ejector was simulated by Fluent Computational Fluid Dynamics (CFD) software. A conventional finite-volume scheme was utilized to solve two-dimensional transport equations with the standard k-ε turbulence model. In the optimization study of the constant-area jet ejectors, all parameters were expressed in dimensionless terms. The objective of the study was to investigate the optimal length, throat diameter, and optimal nozzle diameter at any operating conditions. Also, the optimum compression ratio and efficiency were calculated. By comparing simulation results to an experiment, CFD modeling has shown high-quality results. The overall deviation was 8.19%, thus confirming the reliability of the modeling results. The results from the optimization study indicate that the jet ejector efficiency improves significantly compared to a conventional jet-ejector design. In cases with a subsonic motive velocity, the efficiency of the jet ejector is greater than 90%. A high compression ratio can be achieved with greater motive velocity and mass flow ratio. The ejector performance between the optimal jet ejectors and conventional jet ejectors provided by Graham Corporation was compared. The results show that substituting a single optimal jet ejector for a single conventional ejector reduces the motive stream consumption by about 10% to 30%, which could decrease operating costs tremendously. Dimensionless group analysis reveals that the research results are valid for any fluid, operating pressure and geometric scale for a given motive-stream Mach number and momentum ratio. The explanation of how to implement the optimization results and selecting the best operating conditions to minimize the motive stream consumption was included at the end of the dissertation.

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