Unidirectional compression of electrorheological fluids in electric fields

A series of unidirectional compression tests on electrorheological fluids has been carried out with different plate sizes, initial plate separations, and applied voltages. Experimental results of compression pressure were compared with the continuum non-Newtonian squeeze-flow theory in a normalized form. It was found that the compression resistance of the electrorheological fluid in an electric field was much higher than that predicted by the theory when the fluid was compressed to some extent and/or when the initial plate separation was relatively small. Characteristics of the pressure variation with the reduction in electrode gap width have been analyzed, and the compression behaviors under different experimental conditions have been discussed in terms of the morphology of particle aggregations under compression.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87377/2/074901_1.pd

The effects of different additives on the dielectric relaxation and the dynamic mechanical properties of urethane dimethacrylate

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73548/1/j.1365-2842.2000.00491.x.pd

The effects of moisture on the dielectric relaxation of urethane dimethacrylate polymer and composites

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75059/1/j.1365-2842.2001.00669.x.pd

Developing attribute acquisition strategies in spoken dialogue systems via user simulation

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2006.Includes bibliographical references (p. 159-169).A spoken dialogue system (SDS) is an application that supports conversational interaction with a human to perform some task. SDSs are emerging as an intuitive and efficient means for accessing information. A critical barrier to their widespread deployment remains in the form of communication breakdown at strategic points in the dialogue, often when the user tries to supply a named entity from a large or open vocabulary set. For example, a weather system might know several thousand cities, but there is no easy way to inform the user about what those cities are. The system will likely misrecognize any unknown city as some known city. The inability of a system to acquire an unknown value can lead to unpredictable behavior by the system, as well as by the user. This thesis presents a framework for developing attribute acquisition strategies with a simulated user. We specifically focus on the acquisition of unknown city names in a flight domain, through a spell-mode subdialogue. Collecting data from real users is costly in both time and resources. In addition, our goal is to focus on situations that tend to occur sporadically in real dialogues, depending on the domain and the user's experience in that domain.(cont.) Therefore, we chose to employ user simulation, which would allow us to generate a large number of dialogues, and to configure the input as desired in order to exercise specific strategies. We present a novel method of utterance generation for user simulation, that exploits an existing corpus of real user dialogues, but recombines the utterances using an example-based, template approach. Items of interest not in the corpus, such as foreign or unknown cities, can be included by splicing in synthesized speech. This method allows us to produce realistic utterances by retaining the structural variety of real user utterances, while introducing cities that can only be resolved via spelling. We also developed a model of generic dialogue management, allowing a developer to quickly specify interaction properties on a per-attribute basis. This model was used to assess the effectiveness of various combinations of dialogue strategies and simulated user behavior. Current approaches to user simulation typically model simulated utterances at the intention level, assuming perfect recognition and understanding. We employ speech to develop our strategies in the context of errors that occur naturally from recognition and understanding.(cont.) We use simulation to address two problems: the conflict problem requires the system to choose how to act when a new hypothesis for an attribute conflicts with its current belief, while the compliance problem requires the system to decide whether a user was compliant with a spelling request. Decision models were learned from simulated data, and were tested with real users, showing that the learned model significantly outperformed a heuristic model in choosing the "ideal" response to the conflict problem, with accuracies of 84.1% and 52.1%, respectively. The learned model to predict compliance achieved a respectable 96.3% accuracy. These results suggest that such models learned from simulated data can attain similar, if not better, performance in dialogues with real users.by Edward A. Filisko.Ph.D

Thermoelastic effect in liquid mercury at high hydrostatic pressures

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43034/1/10855_2005_Article_BF01672058.pd

Thermal effects in styrene-butadiene rubber at high hydrostatic pressures

The temperature changes as a result of rapid hydrostatic pressure applications are reported for unvulcanized styrene-butadiene rubber (SBR) in the reference temperature range from 292 to 405 K and in the pressure range from 13.8 to 200 MN m-2. The thermal effects were found to be a function of pressure and temperature. A curve fitting analysis showed that the empirical curve ([part]T/[part]P)=ab([Delta]P)b-1, described the experimental thermoelastic coefficients obtained from the experiments. The data were analysed by determining the predicted thermoelastic coefficients derived from the Thomson equation ([part]T/[part]P)=[alpha]To/[varrho]Cp. The experimental and the predicted Gruneisen parameter [gamma]T were also estimated. Close agreement was found at low pressure but differences were observed at higher pressures between the experimental and expected values for the thermoelastic coefficients and the Gruneisen parameter.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25970/1/0000036.pd

Character of adsorbed bovine serum albumin from adsorption enthalpies

Heats of adsorption of BSA onto polystyrene and polycarbonate were determined microcalorimetrically. The polymers were coated onto 50 nm alumina particles which were immersed in buffer for the measurements. Experimental variations to isolate the various component reactions of the integral heats included adsorption of native and denatured BSA from solution, adsorption onto substrates precoated with BSA, varying the thicknesses of adsorbed BSA by varying concentrations of the adsorbing solutions, and determining the denaturation energy by solution of the solid native and denatured BSA into a denaturing solvent.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26061/1/0000135.pd

Similarities in the fracture surface features of borosilicate and polymer glasses

Considerable similarity exists between the features on the fracture surfaces of a borosilicate glass and those on the fracture surfaces of polymer thermoset glasses like epoxies and vinyl esters. These features include the steps and welts of the hackle, the arrays of skewed cracks, and the basic longitudinal texture. It was the latter, the basic longitudinal texture, that was the most surprising find on the fracture surfaces of borosilicate glass. On the fracture surfaces of polymer thermoset glasses, the basic longitudinal texture has been interpreted as a remnant from the fracturing process, arising from an instability in the meniscus between air and a polymer layer softened or “liquified” by the stresses of cracking. The meniscus instability results in an array of crack fingers preceding the nominal crack front. By analogy, it is suggested that the borosilicate glass fractures by a similar process, including the softening of the glass ahead of the crack front. The basic longitudinal texture is usually visible only at high magnification and often requires (a necessity for the borosilicate glass fracture surface) the tilting of the normal to the fracture surface toward the detector. The steps, welts and arrays of skewed cracks are simply explained with the crack fingering hypothesis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44692/1/10853_2006_Article_BF02385750.pd

Preceramic Polymer Route to Amorphous and Crystalline Potassium Aluminosilicate Powders and Their Electrorheological Properties

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65491/1/j.1151-2916.1997.tb03001.x.pd