Thesis (Ph. D. in food science)--Washington State University, December 2007. / Includes bibliographical references.

Clomazone is an effective herbicide widely used for preemergence grass control in rice. However, use of clomazone on sandy textured soils of the western Texas rice belt may cause serious rice injury. When labeled for rice in 2001, sandy textured soils were excluded. Laboratory experiments were conducted to determine the effect of soil characteristics and water potential on plant-available clomazone and rice injury. A centrifugal double-tube technique was used to determine plant-available concentration in soil solution (ACSS), total amount available in soil solution (TASS), and Kd values for clomazone on four soils at four water potentials. A rice bioassay was conducted parallel to the plant-available study to correlate biological availability to ACSS, TASS, and Kd. TASS was significantly different in all soils at the 1% level of significance. The order of increasing TASS for the soils studied was Morey Edna Nada Crowley which correlated well with soil characteristics. Two field experiments at three locations were conducted in 2002 and 2003 to determine the optimum rate range that maximizes weed control and minimizes crop injury across a wide variety of soil textures and planting dates. At Beaumont, Eagle Lake, and Ganado, TX, preemergence application of 0.41 to 0.56, 0.38 to 0.43, and 0.36 to 0.42 kg ha-1 clomazone, respectively, provided optimum weed control with minimal rice injury. Data suggests that clomazone is safe to use on rice on sandy textured soils. Injury may occur, but, rates suggested from this research will minimize injury and achieve excellent weed control. As a result, amendments to the herbicide label will allow clomazone use on sandy textured soils giving rice producers more flexibility and access to another effective herbicide.

In visualization problems, surface shape is often a piece of data that must be shown effectively. One factor that strongly affects shape perception is texture. For example, patterns of texture on a surface can show the surface orientation from foreshortening or compression of the texture marks, and surface depth through size variation from perspective projection. However, texture is generally under-used in the scientific visualization community. The benefits of using texture on single surfaces also apply to layered surfaces. Layering of multiple surfaces in a single viewpoint allows direct comparison of surface shape. The studies presented in this dissertation aim to find optimal methods for texturing of both single and layered surfaces. This line of research starts with open, many-parameter experiments using human subjects to find what factors are important for optimal texturing of layered surfaces. These experiments showed that texture shape parameters are very important, and that texture brightness is critical so that shading cues are available. Also, the optimal textures seem to be task dependent; a feature finding task needed relatively little texture information, but more shape-dependent tasks needed stronger texture cues. In visualization problems, surface shape is often a piece of data that must be shown effectively. One factor that strongly affects shape perception is texture. For example, patterns of texture on a surface can show the surface orientation from foreshortening or compression of the texture marks, and surface depth through size variation from perspective projection. However, texture is generally under-used in the scientific visualization community. The benefits of using texture on single surfaces also apply to layered surfaces. Layering of multiple surfaces in a single viewpoint allows direct comparison of surface shape. The studies presented in this dissertation aim to find optimal methods for texturing of both single and layered surfaces. This line of research starts with open, many-parameter experiments using human subjects to find what factors are important for optimal texturing of layered surfaces. These experiments showed that texture shape parameters are very important, and that texture brightness is critical so that shading cues are available. Also, the optimal textures seem to be task dependent; a feature finding task needed relatively little texture information, but more shape-dependent tasks needed stronger texture cues.

"none"

In visualization problems, surface shape is often a piece of data that must be shown effectively. One factor that strongly affects shape perception is texture. For example, patterns of texture on a surface can show the surface orientation from foreshortening or compression of the texture marks, and surface depth through size variation from perspective projection. However, texture is generally under-used in the scientific visualization community. The benefits of using texture on single surfaces also apply to layered surfaces. Layering of multiple surfaces in a single viewpoint allows direct comparison of surface shape. The studies presented in this dissertation aim to find optimal methods for texturing of both single and layered surfaces. This line of research starts with open, many-parameter experiments using human subjects to find what factors are important for optimal texturing of layered surfaces. These experiments showed that texture shape parameters are very important, and that texture brightness is critical so that shading cues are available. Also, the optimal textures seem to be task dependent; a feature finding task needed relatively little texture information, but more shape-dependent tasks needed stronger texture cues. In visualization problems, surface shape is often a piece of data that must be shown effectively. One factor that strongly affects shape perception is texture. For example, patterns of texture on a surface can show the surface orientation from foreshortening or compression of the texture marks, and surface depth through size variation from perspective projection. However, texture is generally under-used in the scientific visualization community. The benefits of using texture on single surfaces also apply to layered surfaces. Layering of multiple surfaces in a single viewpoint allows direct comparison of surface shape. The studies presented in this dissertation aim to find optimal methods for texturing of both single and layered surfaces. This line of research starts with open, many-parameter experiments using human subjects to find what factors are important for optimal texturing of layered surfaces. These experiments showed that texture shape parameters are very important, and that texture brightness is critical so that shading cues are available. Also, the optimal textures seem to be task dependent; a feature finding task needed relatively little texture information, but more shape-dependent tasks needed stronger texture cues.

none

The current study developed a simple rolling-type TMT to process the commerical 5083 Al to exhibit low temperature superplacticity at 230 and 250 oC, with optimum tensile elongation to 511% and 443%. The TMT processed thin sheet contained (sub)grains measureing 0.3 um. The bimodal of grain boundary misorientation distribution of as-TMT3 would be gradually replaced by a more random distribution if the alloy was subjected to increase TMT or tensile deformation strain level. It would be lost it's superplasticity when the testing temperature was higher than 270 oC. But it would exhibit superplasticity again when the thsting temperature was higher than 400 oC.

Clomazone is an effective herbicide widely used for preemergence grass control in rice. However, use of clomazone on sandy textured soils of the western Texas rice belt may cause serious rice injury. When labeled for rice in 2001, sandy textured soils were excluded. Laboratory experiments were conducted to determine the effect of soil characteristics and water potential on plant-available clomazone and rice injury. A centrifugal double-tube technique was used to determine plant-available concentration in soil solution (ACSS), total amount available in soil solution (TASS), and Kd values for clomazone on four soils at four water potentials. A rice bioassay was conducted parallel to the plant-available study to correlate biological availability to ACSS, TASS, and Kd. TASS was significantly different in all soils at the 1% level of significance. The order of increasing TASS for the soils studied was Morey Edna Nada Crowley which correlated well with soil characteristics. Two field experiments at three locations were conducted in 2002 and 2003 to determine the optimum rate range that maximizes weed control and minimizes crop injury across a wide variety of soil textures and planting dates. At Beaumont, Eagle Lake, and Ganado, TX, preemergence application of 0.41 to 0.56, 0.38 to 0.43, and 0.36 to 0.42 kg ha-1 clomazone, respectively, provided optimum weed control with minimal rice injury. Data suggests that clomazone is safe to use on rice on sandy textured soils. Injury may occur, but, rates suggested from this research will minimize injury and achieve excellent weed control. As a result, amendments to the herbicide label will allow clomazone use on sandy textured soils giving rice producers more flexibility and access to another effective herbicide.

Non-contacting annular seals are internal sealing devices used in rotating machinery, such as multistage centrifugal pumps and compressors. Their design affects both efficiency and rotor stability. Traditional plain and labyrinth seals are being replaced with stators containing different roughness patterns to reduce leakage and enhance rotor response. Several roughened seal experiments with liquid and air have produced leakage data indicating that the friction factor increases as the seal clearance is increased. Simplified models based on bulk flow theory and Moody’s approach to characterize wall friction in pipes cannot explain this outcome. This research is an extension of a 2-D numerical analysis of flat plate experiments with water which found that friction factor of these surfaces is governed by the roughness’ ability to develop high static pressures. An exhaustive 3-D numerical analysis of several experiments with liquid annular seals has been performed using a CFD code. Direct numerical simulations (DNS) of turbulent channel flow and smooth seals were replicated within 1% using Reynolds-averaged Navier-Stokes (RANS) equations and turbulence modeling. Similarly, measured groove seal leakage rates were reproduced within 2%. On the other hand, no turbulence model combination predicts the leakage in most 3-D pattern roughened seals with the same accuracy. Present results reproduce the friction factor ‘plateau’ behavior predicted with the 2-D analysis and observed in the flat plate experiments. They also reproduce the friction-factor-to-clearance indifference behavior, the maximum friction factor observed in a specific roughness pattern size is independent of the actual clearance in a certain Reynolds number range, but clarify the role of the roughness length-to-clearance ratio and the actual roughness size in defining the friction-factor-toclearance proportionality. All simulations indicate that roughened surface area and roughness aspect ratios are the parameters defining the friction factor at a given seal clearance. The roughness pattern size, relevant in determining the friction-factor-to-clearance proportionality, plays a moderate role once the above cited ratios are defined. In any shape and size, shallow patterns are predicted and observed to provide larger friction factors than deep patterns. Predictions also confirm limited experimental data showing that friction factor is affected by the mean flow orientation relative to the roughness pattern. Solving RANS equations is sufficient to model simple seal geometries but might not be enough to replicate turbulent flow in liquid annular seals with roughened surfaces.

It is a time consuming task to generate textures for large 3D terrain surfaces in computer games, flight simulations and computer animations. This work explores the use of cellular automata in the automatic generation of textures for large surfaces. I propose a method for generating textures for 3D terrains using various approaches - in particular, a hybrid approach that integrates the concepts of cellular automata, probabilistic distribution according to height and Wang tiles. I also look at other hybrid combinations using cellular automata to generate textures for 3D terrains. Work for this thesis includes development of a tool called "Texullar" that allows users to generate textures for 3D terrain surfaces by configuring various input parameters and choosing cellular automata rules. I evaluate the effectiveness of the approach by conducting a user survey to compare the results obtained by using different inputs and analyzing the results. The findings show that incorporating concepts of cellular automata in texture generation for terrains can lead to better results than random generation of textures. The analysis also reveals that incorporating height information along with cellular automata yields better results than using cellular automata alone. Results from the user survey indicate that a hybrid approach incorporating height information along with cellular automata and Wang tiles is better than incorporating height information along with cellular automata in the context of texture generation for 3D meshes. The survey did not yield enough evidence to suggest whether the use of Wang tiles in combination with cellular automata and probabilistic distribution according to height results in a higher mean score than the use of only cellular automata and probabilistic distribution. However, this outcome could have been influenced by the fact that the survey respondents did not have information about the parameters used to generate the final image - such as probabilistic distributions, the population configurations and rules of the cellular automata.