Phase limitations of Zames-Falb multipliers

Phase limitations of both continuous-time and discrete-time Zames-Falb multipliers and their relation with the Kalman conjecture are analysed. A phase limitation for continuous-time multipliers given by Megretski is generalised and its applicability is clarified; its relation to the Kalman conjecture is illustrated with a classical example from the literature. It is demonstrated that there exist fourth-order plants where the existence of a suitable Zames-Falb multiplier can be discarded and for which simulations show unstable behavior. A novel phase-limitation for discrete-time Zames-Falb multipliers is developed. Its application is demonstrated with a second-order counterexample to the Kalman conjecture. Finally, the discrete-time limitation is used to show that there can be no direct counterpart of the off-axis circle criterion in the discrete-time domain

Method of remotely characterizing thermal properties of a sample

A sample in a wind tunnel is radiated from a thermal energy source outside of the wind tunnel. A thermal imager system, also located outside of the wind tunnel, reads surface radiations from the sample as a function of time. The produced thermal images are characteristic of the heat transferred from the sample to the flow across the sample. In turn, the measured rates of heat loss of the sample are characteristic of the flow and the sample

PED: pressurized electroosmotic dewatering

Mechanical solid/liquid separation or dewatering of fine-grained suspensions is difficult to accomplish with any degree of success, cost effectiveness and/or practicality. The use of electroosmosis, the electrokinetic transport of water, which is theoretically independ- ent of pore size, on the other hand can be quite slow and consume a great deal of electrical energy. However, in combining pressure and electroosmosis, an effective dewatering process is realized because the strength of each dewatering process is the weakness in the other and the combination of the two processes has no ill effect on each other. The strength of electroosmosis is in its independence of pore size, whereas pressure removes the free water from the larger pores rapidly and causes consolidation to occur. Electroosmosis has no intergranular effects, so consolidation is beneficial to the electro- osmotic process in that the pores remain saturated for a longer time, menisci do not form and an induced hydraulic gradient opposing the electroosmotic gradient is not established as soon.;The experimental program investigated the optimization of pressurized electroosmotic dewatering (PED) of ultra-fine coal suspensions. The slurry characteristics of greatest interest were the particle size distribution and zeta potential. The particle size distri- bution controls the maximum packing density and thus, the lowest pore volume, obtainable. A reduction in pore volume increases the degree of saturation for a given quantity of water. The zeta potential of a suspension directly governs the electroosmotic flow rate.;A computerized data acquisition system was built to monitor the PED tests. This enhanced the research by allowing more test data to be obtained in a short time and more testing to be completed because of the reduced test analysis time. Also, other suspended materials such as kaolinite slurries, lignite slurries, phosphate slimes, red mud, fly ash scrubber slimes and diamond slimes were tested using PED.;The test results provide a basis for pilot-scale testing of PED in a continuous manner. A pilot-scale study will provide process;algorithms for economic commercial applications of PED and incorporate full-scale equipment constraints.; (\u271)DOE Report IS-T-1223. This work was performed under contract No. W-7405-Eng-82 with the U.S. Department of Energy

Examination of the World3 Model and the Development of a Novel Model of a Multi-market, Multi-regional Economy Driven by Adaptive Heterogeneous Consumer Agents

Ever since the human race developed consciousness we have battled against the elements to bring about prosperity and health. For millennia we closely observed the natural phenomena that seemed to influence future outcomes, gradually building and refining our conceptions of reality, our mental models. We refined the process of observation and discovery with the scientific method, and from that point on our power to control our environment grew immensely. Now our greatest foe is not only Mother Nature, but ourselves. We still act impulsively, and make decisions which seem irrational. We may guiltily watch hour after hour of Antiques Road Show, instead of spending a mere 30 minutes finishing off the final thesis chapter. The tradition of model development is continued herein, with a focus on holistic socio- ecological models. The first part of this thesis examines the pre-existing Limits to Growth model, originally developed by Meadows et. al. in 1972. Uncertainty analysis was per- formed on this model to develop a better understanding of its reliability. This model is also used to better understand the trade-off relationships between common goals humans wish to achieve in the future. A genetic algorithm was used to determine the Pareto front of the seven examined goals. The final part of the thesis presents a novel model designed to allow many simulated human actors to make purchasing decisions in a self determining fashion, based on the cost of various goods. The new model simulates multi-item market- places, floating prices on goods, and spacial effects on trading and resource extraction. A preliminary version of the model is tested under eight different conditions, and the results are presented and discussed

The Detection of Potato Cyst Nematode (PCN) Infestation Using Remotely Sensed Imagery

Potato cyst nematodes (PCN) Globodera pallida Stone and G. rostochiensis (Wollenweber) are economically-important pests which cause significant losses to potato production world-wide. Population control is a major objective of a sustainable management strategy as nematodes are persistent and reproductive rates can be high. Current methods of determining PCN population densities are both expensive and time consuming: an advance on current sampling methods would facilitate the application of precision farming methods to PCN management. The potential for using light reflected from the potato canopy as an assay to detect PCN infestation is investigated. Spectral reflectance was measured from the canopy of commercial potato crops, individual plants and single leaves with a field spectrometer, airborne remote sensing and from SPOT and Ikonos satellite images. Comparisons between the reflectance from healthy and infected plants revealed a significant reduction in green (c. 550nm) reflectance from infested plants, and this was consistent across seasons, cultivars and imaging methods. The strongest results were seen early in the crop cycle, although full canopy development is desirable in airborne and satellite image analysis. Yield-limiting pathogens are frequently reported as increasing visible reflectance by reducing chlorophyll concentration in the leaves of afflicted plants. The spectral response to PCN infestation is distinct from that from common plant stress factors and a PCN- specifrc detector system is proposed. A viable commercial PCN assay would need to be timely, reliable and cost-effective. Whilst aircraft and satellite platforms offer the rapid acquisition of data from large areas, these imaging methods are heavily dependent on weather conditions. Results from data collected using a hand-held chlorophyll meter in this investigation indicate that a closed, or semi-closed imaging system (enclosing or covering the plant canopy) would be suited to the detection of PCN under field conditions and less susceptible to inclement weather

A Wellness Profile of Student-Veterans at 4-Year Higher Education Institutions: The Role of Gender, Combat Tours, and Deployment

Afghanistan and Iraq war student-veterans have increased in population on college campuses in the United States (U.S.) as a result of using the Post 9/11 GI Bill. Healthy Campus 2020 (American College Health Association, 2012) highlighted the importance of college student wellbeing, health promotion and disease prevention, while the U.S. Department of Veteran Affairs has called for an approach to services that is strength based (United States Department of Veteran Affairs, 2008). To date, however, wellness studies conducted on Iraq and Afghanistan student-veterans using an evidenced-based model of holistic wellness have not been conducted. This study was designed to address this gap in the literature. An expo facto study was used in this research. This study received 143 respondents from 17 of the top 30 four-year universities in the U.S. with the greatest number of participants using the Post 9/11 GI Bill. Participants completed several forms on-line to collect data, including a demographics questionnaire and the Five Factor Wellness Inventory (5F-Wel) as the measure of holistic wellness. This study sought to investigate differences among student-veterans in terms of gender, deployment, tours of duty and holistic wellness levels. Out of the 143 student-veterans 132 were included for statistical analysis. This study used a series of two-way ANOVAs that resulted in a significant main gender effect on the Essential Self. Female student-veterans had a significantly higher mean score than male student-veterans, however there was a small to medium effect size

Does Self-Complexity Predict Dishonest Behavior Via Cognitive Dissonance?

Psychologists disagree about what, if any, benefit high self-complexity might provide. Although Linville (1987) demonstrated that high complexity buffers against stress, other studies have found that it leads to more negative outcomes in the long term (Diehl et al., 2001). Cognitive dissonance is an important factor in regulating behavior, particularly moral behavior (Aronson, Fried, & Stone, 1999), and may explain how self-complexity leads to negative life outcomes. The present study examined if high self-complexity might buffer against the tension of cognitive dissonance, thus increasing the likelihood of dishonest behavior. Participants completed a selfcomplexity measure, and then they completed a dissonance-rousing task where they must choose between providing honest answers or maximizing their personal gain. Regression analysis showed that high self-complexity predicted greater dishonest behavior, but a disruption of cognitive dissonance could not account for this relationship. The possibility of personality as a potential mediating variable for the established relationship, and avenues for future research, are discussed