Field, greenhouse and laboratory experiments were implemented to investigate the effects of auxin herbicides on growth and yield of cotton in glyphosate based systems. Field experiments evaluated the effect of rate and timing of dicamba or 2,4-D exposure when applied in glyphosate-resistant cotton. Increasing rates of either dicamba or 2,4-D resulted in increased injury and yield reductions. Initial injury symptomology was similar for cotton exposed at vegetative and reproductive stages. When cotton was exposed to auxin herbicides during vegetative growth, injury increased with time, while foliar injury during reproductive growth was stagnant and often decreased with time. Subsequently, the strongest correlations to yield loss and injury were from later evaluations of vegetative timings. Recovery from injury due to auxin herbicide exposure was dependent upon favorable environmental conditions; however, recovery was often superficial and masked significant yield loss. Greenhouse studies evaluated the impact of the diglycolamine dicamba salt on the movement of 14C radio-labeled potassium salt glyphosate in barnyardgrass and johnsongrass. Increasing glyphosate rate increased total absorption of glyphosate in both species. Total absorption of glyphosate was not impacted by the presence of dicamba, for either johnsongrass or barnyardgrass. Dicamba did not consistently alter the translocation of glyphosate in johnsongrass; however, dicamba did reduce glyphosate translocation in barnyardgrass. Total amount of translocated glyphosate was 2.6 to 4.6% and 3.8 to 6.8% of applied in barnyardgrass and johnsongrass, respectively. Reduced translocation in barnyardgrass was a result of increased glyphosate accumulation in the distal portion of the treated leaf. Increasing the rate of glyphosate did overcome the dicamba induced antagonism; however, altered translocation of glyphosate has been documented to be a precursor to herbicide resistance.

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No description available.

No description available.

It is well established that musicians deviate substantially from regular timing in music performance, and numerous studies have sought to characterize the origin of different expressive deviations. However, this work has thus far been limited by the necessity of analyzing renditions produced by highly-trained adult musicians, which precludes the opportunity to ask questions about how development and formal experience might affect expressive timing. In the present dissertation, I introduce a new paradigm for examining musical production in non-expert participants, the musical dwell time paradigm. In Chapters 2 and 3, I show that musically untrained adults and children as young as three years pause on phrase-final chords when self-pacing through chord sequences, mirroring the phenomenon of phrase-final lengthening that has been reported in expert music performance. I additionally demonstrate that by four years of age, this lengthening can be elicited by harmonic cues when other cues to phrase boundaries (metrical regularity and melodic contour) are controlled for. In Chapter 4, I show that when communicating different emotions through music, nonmusicians use expressive cues in a way that is highly consistent with expert musicians, and that there is striking similarity across participants despite a wide range of musical training. Finally, in Chapter 5, I demonstrate that children as young as 5 years olds’ performances mirror adults’ in their use of timing and loudness cues, and that their renditions become more adult-like by 7 years. Altogether, these findings corroborate previous claims that musically untrained adults are “listening experts” with substantial musical knowledge, extend these results to show that in performance musically untrained adults use timing and loudness similarly as expert musicians to delineate phrases and express emotions, and show that some elements are in place by early childhood. Overall, the musical dwell time paradigm offers a new, highly flexible method for examining musical production in participants with a wide variety of musical training. / Thesis / Doctor of Philosophy (PhD) / Musicians often deviate from the durations notated in their musical score, slowing and speeding over the course of a performance. In the absence of deviations, music sounds mechanical or computerized rather than expressive. Studies of performances by highly-trained musicians have identified patterns in the way these duration changes are implemented, but no previous research has investigated whether formal musical experiences and development contribute to these patterns. I developed a simple music production apparatus that enables musically untrained adults and children to perform music. I asked participants to “perform” chord sequences under different conditions and measured the amount of time they spent on each chord. I uncovered how young children and untrained adults use timing deviations to delineate musical phrase groups and to communicate musical emotions. Overall, my work offers a new way to examine expressive timing patterns and suggest that formal training alone does not fully account for these patterns.

The paper presents a computer-based guide of the effect of layout and loading (tension and torque) on the timing belt life and uses it to show the sensitivity of life to changed conditions in an automotive camshaft drive. The predictions are in line with experience. The guide requires belt property information, such as the tooth and tension member stiffness, the friction coefficient between the belt lands and pulleys and the pitch difference from the pulley, in order to calculate the tooth deflections caused by the belt loadings on the various pulleys in the layout. It also requires information on how the belt life depends on the tooth deflections. Experimental data are presented on the life±deflection relations of a commercial automotive timing belt tested between 100 and 140 8C, although the bulk of the data has been obtained at 120 8C. Four different life laws have been found, depending on whether the failure-initiating deflection occurred on a driver or a driven pulley, and whether at entry to or exit from the pulley. Theoretical analysis of the tooth loading in the partial meshing state shows that, in three cases out of the four, the different life±deflection laws transform to a single relation between the life and the tooth root strain. The exception is failure caused by driven entry conditions; work is continuing to understand better the causes of failure in this circumstance

Piezoelectric actuation is an expanding field that makes use of piezoelectric materials that have high power density as actuators. These actuation systems have the potential higher power density than the traditional servo motor technology. However, due to tiny strain of the piezoelectric materials, displacement amplification mechanism should be incorporated into design for most commercial applications. Piezohydraulic actuation provides an ideal amplification that can achieve any combination of stroke and force, which is superior than most other amplification technologies. The concept of piezohydraulic actuation takes advantage of the high force capabilities that piezoceramics have and combines it with the operation at high frequencies, in order to achieve the hydraulic actuation of a system under a specified stroke and force. In this research, a compact piezohydraulic pump with active valves has been developed, tested and characterized. Furthermore, theoretical models are developed based on different levels of approximation of the hydraulic fluid. The first model, which assumes an incompressible and inviscid fluid, provides us views of the basic features of piezohydraulic actuation. The second model which takes into account the viscosity of the fluid and the third model which takes into account both viscosity and compressibility of the fluid are then presented. Then, their simulation results are compared with experimental data, which shows the compressibility of the fluid is important to system performance. At last, a power and efficiency analysis based on experimental results is presented. / Master of Science

In research environments, many soft switching inverters have been conceived, simulated, designed, implemented and proven to have advantages over hard switched inverters. To date however, no soft-switching inverters have reached commercial production for various reasons. The fixed timing coupled inductor soft-switching inverter is of interest because in simulation and previous implementation it exhibits load and source adaptability using simple RC timer circuitry and can be implemented with low cost active auxiliary devices. During the course of this implementation, it is noted that attempting to use excessively small/inexpensive active auxiliary devices has reliability ramifications related to device packaging. The issue of auxiliary active device reliability is conjectured upon by referencing available datasheet information, application specific requirements, device pulse testing and secondary research findings related to semiconductor failure characteristics. It is also noted that aspects of the simple fixed timing circuitry operation, in conjunction with coupled inductor and saturable inductor design, can lead to coupled inductor saturation if not properly addressed. Simulation is performed and validates various causes for this non-ideal behavior. / Master of Science

No / This paper presents and compares the most important and often used methods to measure turbine blade vibrations: use of strain gauges and telemetry system which is an intrusive method or, on the other site. The Blade Tip Timing (BTT) method known as Non-Intrusive Stress Measurement (System) NSMS. Both methods have advantages and disadvantages which are described below. This paper focused on synchronous vibrations, which are more important in terms of turbine blades fatigue prediction and design optimization.

This thesis presents a design system that significantly speeds up development of VHDL behavioral models with back annotated timing. The behavioral model is developed using the CAD tool called Modeler's Assistant by inputting the model in the form of a Process Model Graph. Then using the built-in primitive process library and user responses the Modeler's Assistant generates a complete VHDL source description of the model. The models developed can be classified into four classes. The first class of circuits are combinational fanout free circuits in which the fanout of each process in the Process Model Graph is one. Combinational circuits in which outputs of the processes are fed in as input to more than one process are classified as Class 2 circuits. Sequential register circuits are classified as class 3 circuits. Class 4 circuits are highly sequential circuits which have either feedback loops or irregular register or flip-flop structures. The principle for back annotating the generic delay values is discussed for the first three classes of circuits. The back annotation tool Backann2 uses the VHDL description from the Modelers Assistant, the CLSI -VTIP CAD tool and the Synopsys Design Compiler to calculate the timing delays and to back annotate the delays into the behavioral model. The CLSI -VTIP tool is used to extract the details from the VHDL model and store it in the form of data structures. These details are used for computing the paths traversed by the signals associated with the generics. The behavioral model is synthesized into a gate level design and the end to end delays in the model are obtained using Synopsys Design Compiler. With the end to end delays and the different paths traversed by the signals an algorithm to find realistic and accurate delays has been found. Thus a system is available to designers which builds behavioral models with accurate timing information. / Master of Science