10/25/1947 Letter from Superintendent A. A. Woodworth

Letter from A. A. Woodworth, Chairman on the Committee of Arrangements for the Maine Teachers\u27 Association, to Louis-Philippe Gagné.https://digitalcommons.usm.maine.edu/fac-lpg-1947-10-12/1018/thumbnail.jp

Palladium and nickel interactions with stepped 6H-silicon carbide

Silicon carbide (SiC) has long been recognized as a semiconductor with potential for use in a number of demanding environments. Recent developments in the quality of bulk grown 6H-SiC (and other hexagonal poly-types) have increased interest in issues surrounding the stability of device structures that operate at temperatures in excess of 600°C. It has been observed that the performance of metal-semiconductor devices created on SiC tend to degrade when operating at these temperatures. This change in device performance has been linked to inter-diffusion and reaction at the metal-semiconductor interface. Most of these devices have been fabricated on SiC substrates with surface and sub-surface damage associated with the polishing process (standard surfaces). Recent studies have shown that high temperature hydrogen etching of these substrates removes this damage and produces surfaces with wide atomically flat terraces and nanometer scale steps (stepped surfaces). The basic question this poses is, can such improvements in substrate quality lead to improvements in device performance.;The goal of this research is to better understand the interaction of metals on these stepped surfaces. To accomplish this, detailed surface studies of thermally induced Pd-SiC and Ni-SiC surface interactions have been performed on both the standard and stepped surfaces. The metal films range in thickness from the monolayer level (∼0.4 nm) to actual device dimensions (∼50 nm) and are deposited under ultrahigh vacuum conditions at ∼50°C. These films were characterized in-situ using Auger electron spectroscopy both before and after annealing at 670°C for Pd and 700°C for Ni. The Auger lineshapes provide quantitative and qualitative information on the chemistry of the reaction products. Ex-situ atomic force microscopy was used to characterize changes in surface morphology. The results of these experiments yield important insights into the nature of the transport process at the metal-semiconductor interface and the influence of initial surface structure in these processes. In addition differences in the interfacial chemistry for carbide forming metals has been revealed. The results provided insight into the mechanisms where by improvements in substrate quality may lead to improvements in device performance

The Globular Cluster Systems in the Coma Ellipticals. III: The Unique Case of IC 4051

Using archival \hst WFPC2 data, we derive the metallicity distribution, luminosity function, and spatial structure of the globular cluster system around IC 4051, a giant E galaxy on the outskirts of the Coma cluster core. The metallicity distribution derived from the (V-I) colors has a mean [Fe/H] = -0.3, a near-complete lack of metal-poor clusters, and only a small metallicity gradient with radius; it may, however, have two roughly equal metallicity subcomponents, centered at [Fe/H] ~ 0.0 and -1.0. The luminosity distribution (GCLF) has the Gaussian-like form observed in all other giant E galaxies, with a peak (turnover) at V = 27.8, consistent with a Coma distance of 100 Mpc. The radial profiles of both the GCS and the halo light show an unusually steep falloff which may indicate that the halo of this galaxy has been tidally truncated. Lastly, the specific frequency of the GCS is remarkably large: we find S_N = 11 +- 2, resembling the central cD-type galaxies even though IC 4051 is not a cD or brightest cluster elliptical. A formation model consistent with most of the observations would be that this galaxy was subjected to removal of a large fraction of its protogalactic gas shortly after its main phase of globular cluster formation, probably by its first passage through the Coma core. Since then, no significant additions due to accretions or mergers have taken place.Comment: 24 pp. plus 13 Figures. Postscript file for the complete paper can also be downloaded from http://www.physun.mcmaster.ca/~harris/WEHarris.html. Astron.J., in pres

Inversion improves the recognition of facial expression in thatcherized images

The Thatcher illusion provides a compelling example of the face inversion effect. However, the marked effect of inversion in the Thatcher illusion contrasts to other studies that report only a small effect of inversion on the recognition of facial expressions. To address this discrepancy, we compared the effects of inversion and thatcherization on the recognition of facial expressions. We found that inversion of normal faces caused only a small reduction in the recognition of facial expressions. In contrast, local inversion of facial features in upright thatcherized faces resulted in a much larger reduction in the recognition of facial expressions. Paradoxically, inversion of thatcherized faces caused a relative increase in the recognition of facial expressions. Together, these results suggest that different processes explain the effects of inversion on the recognition of facial expressions and on the perception of the Thatcher illusion. The grotesque perception of thatcherized images is based on a more orientation-sensitive representation of the face. In contrast, the recognition of facial expression is dependent on a more orientation-insensitive representation. A similar pattern of results was evident when only the mouth or eye region was visible. These findings demonstrate that a key component of the Thatcher illusion is to be found in orientation-specific encoding of the features of the face

Constant net-time headway as key mechanism behind pedestrian flow dynamics

We show that keeping a constant lower limit on the net-time headway is the key mechanism behind the dynamics of pedestrian streams. There is a large variety in flow and speed as functions of density for empirical data of pedestrian streams, obtained from studies in different countries. The net-time headway however, stays approximately constant over all these different data sets. By using this fact, we demonstrate how the underlying dynamics of pedestrian crowds, naturally follows from local interactions. This means that there is no need to come up with an arbitrary fit function (with arbitrary fit parameters) as has traditionally been done. Further, by using not only the average density values, but the variance as well, we show how the recently reported stop-and-go waves [Helbing et al., Physical Review E, 75, 046109] emerge when local density variations take values exceeding a certain maximum global (average) density, which makes pedestrians stop.Comment: 7 pages, 7 figure

A New Method to Grow SiC: Solvent-Laser Heated Floating Zone

The solvent-laser heated floating zone (solvent-LHFZ) growth method is being developed to grow long single crystal SiC fibers. The technique combines the single crystal fiber growth ability of laser heated floating zone with solvent based growth techniques (e.g. traveling solvent method) ability to grow SiC from the liquid phase. Initial investigations reported in this paper show that the solvent-LHFZ method readily grows single crystal SiC (retains polytype and orientation), but has a significant amount of inhomogeneous strain and solvent rich inclusions

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05/15/1947 Letter from Superintendent A. A. Woodworth

Letter from A. A. Woodworth, Superintendent of Public Schools in Lewiston, Maine, to Louis-Philippe Gagné.https://digitalcommons.usm.maine.edu/fac-lpg-1947-04-06/1017/thumbnail.jp

Gender Differences In Students Ethical Impressions Of Questionable Marketing Practices

In this study, we test the theory that female business majors are more sensitive than male business majors to the ethical issues in advertising promotions. We also examine whether or not business majors are as sensitive as liberal arts majors. Our sample is made up of 218 students from the Northeast area of the US. To measure ethical sensitivity in marketing situations, the participants responded to six scenarios developed from actual news data. The results indicate that female students and female business majors were more sensitive to potentially unethical advertising than male students. We also found that liberal arts students were more sensitive to ethical issues than their counterparts in business schools