Spontaneous Coherence and Collective Modes in Double-Layer Quantum Dot Systems

We study the ground state and the collective excitations of parabolically-confined double-layer quantum dot systems in a strong magnetic field. We identify parameter regimes where electrons form maximum density droplet states, quantum-dot analogs of the incompressible states of the bulk integer quantum Hall effect. In these regimes the Hartree-Fock approximation and the time-dependent Hartree-Fock approximations can be used to describe the ground state and collective excitations respectively. We comment on the relationship between edge excitations of dots and edge magneto-plasmon excitations of bulk double-layer systems.Comment: 20 pages (figures included) and also available at http://fangio.magnet.fsu.edu/~jhu/Paper/qdot_cond.ps, replaced to fix figure

Inhalation developmental toxicology studies: Teratology study of 1,3-butadiene in mice: Final report

Maternal toxicity, reproductive performance and developmental toxicology were evaluated in CD-1 mice following whole-body, inhalation exposures to 0, 40, 200 and 1000 ppM of 1,3-butadiene. The female mice, which had mated with unexposed males were exposed to the chemical for 6 hours/day on 6 through 15 dg and sacrificed on 18 dg. Maternal animals were weighed prior to mating and on 0, 6, 11 and 18 dg; the mice were observed for mortality, morbidity and signs of toxicity during exposure and examined for gross tissue abnormalities at necropsy. Live fetuses were weighed and subjected to external, visceral and skeletal examinations to detect growth retardation and morphologic anomalies. Significant concentration-related decreases were detected in a number of maternal body weight measures. There was a significant concentration-related depression of fetal body weights and placental weights. Body weights of male fetuses of all exposed groups were significantly lower than values for control fetuses; weights of female fetuses were significantly depressed in the mice exposed to 200 and 1000 ppM. In the 200- and 1000-ppM exposure groups, weights of placentas of male fetuses were significantly decreased, but placental weights of female fetuses were significantly affected only in litters exposed to the highest 1,3-butadiene concentration. This exposure regimen produced significant signs of maternal toxicity at concentrations of 200 and 1000 ppM 1,3-butadiene

Dominant lethal study in CD-1 mice following inhalation exposure to 1,3-butadiene: Final technical report

The effects of whole-body inhalation exposures to 1,3-butadiene on the reproductive system was evaluated. The results of dominant lethality in CD-1 male mice that were exposed to 1,3-butadiene are described. Subsequent to exposure, males were mated with two unexposed females. Mating was continued for 8 weeks with replacement of two females each week. Gravid uteri were removed, and the total number, position and status of implantations were determined. The mice were weighed prior to exposure and at 0, 1, 2, 3, 4, 5, 6, 7, and 8 weeks after exposure and at sacrifice. The animals were observed for mortality, morbidity and signs of toxicity throughout the study. 19 refs., 5 figs., 9 tabs

Protein Efficiency Ratio and Amounts of Selected Nutrients in Mechanically Deboned Spent Layer Meat

Three types of mechanically deboned spent layer meat (MDSL) were found to have adjusted protein efficiency ratios (PER) equivalent or superior to a standard (casein) diet. These same materials proved to be good sources of calcium, iron and zinc. Percentage protein ranged from 15.39 for MDSL from whole spent layers to 16.55 for MDSL from spent layer frames with wings. Fat levels were highest for whole birds (20.41%) and lowest for frames without skin (16.84%). High levels of unsaturated fatty acids were found to be associated with these products.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71440/1/j.1365-2621.1982.tb10143.x.pd

Research on Presence in Virtual Reality: A Survey

Virtual Reality (VR) is starting to be used in psychological therapy around the world. However, a thorough understanding of the reason why VR is effective and what effect it has on the human psyche is still missing. Most research on this subject is related to the concept of presence. This paper gives an up-to-date overview of research in this diverse field. It starts with the most prevailing definitions and theories on presence, most of which attribute special roles for the mental process of attention and for mental models of the virtual space. A review of the phenomena thought to be effected by presence shows that there is still a strong need for research on this subject because little conclusive evidence exists regarding the relationship between presence and phenoma such as emotional responses to virtual stimuli. An investigation shows there has been substantial research for developing methods for measuring presence and research regarding factors that contribute to presence. Knowledge of these contributing factors can play a vital role in development of new VR applications, but key knowledge elements in this area are still missing.Electrical Engineering, Mathematics and Computer Scienc