Growth of U.S. Ecotourism and Its Future in the 1990s

Ecotourism, a new term for low-impact nature travel, is receiving increasing attention. The author has researched the development of the U.S. ecotourism market from 1980-1989 in order to obtain data on the growth of this market segment. Factors involved in the growth of the U.S. ecotourism market are then examined in order to project the growth of this maeket during the 1990\u27s

The Role of Youth Arts: Providing Opportunity and Intervention for At-Risk Populations

The Role of Youth Arts: Providing Opportunity and Intervention for At-Risk Populations considers the positive outcomes of arts experiences during childhood and adolescence. The benefits of arts education include cognitive, social, and emotional growth. The arts are also seen to improve student learning, achievement, and engagement on many levels. Childhood arts participation directly affects adult arts engagement in which individuals gain the cultural capital that allows for social ascent. As well as being a means for opportunity, art can be used as a means of intervention for at-risk youth populations. Through art, children and teens find meaning, belonging, and success that they lack in other areas. This work will discuss my role developing an activity for an at-risk youth program called PATROL, that partners Johnson City police officers with children from local housing authorities. The programs teaches positive actions and decision making while offering support and mentorship for the youth participants

Time-resolved RHEED Studies of the Growth of Epitaxial ZnSe Films on GaAs By Pulsed Laser Deposition

Film growth consists of two basic processes, deposition and surface relaxation, with opposing effects on the evolution of surface roughness. The pulsed-laser deposition (PLD) growth process has the unique feature of having periods of very high deposition rates on ms time scales followed by periods, on the order of seconds, with only surface relaxation. In this paper we report the first efforts towards exploiting this unique feature to study these two basic processes independently. Thin epitaxial films of ZnSe were grown using PLD on (001) GaAs and 2° miscut (001) GaAs substrates. For growth on both the singular and vicinal surfaces, RHEED patterns taken following growth showed clear, streaky first zone and sharp second zone spots, and well-defined Kikuchi lines; these features are indicative of a smooth growth surface and high quality film. No reconstruction of the growth surface was observed, in contrast to behavior observed in molecular beam epitaxy. Time-resolved RHEED measurements show that a single morphology developed during growth on singular (001) GaAs. However, during growth on miscut (001) GaAs, two morphologies developed, one transitory and one appearing to evolve towards steady state. When growth on the miscut substrate was stopped, recovery of the RHEED signal was observed. The rate of recovery could be attributed to two relaxation processes, as differentiated by their time constants. Potential origins of these observations are discussed.Engineering and Applied Science

Retail Investors: Why Online Investing Platforms Need More Regulation and Oversight

Retail trading, in the age of the COVID-19 pandemic, has reached impressive and consequential levels, mostly due to the rise in popularity of online investing platforms. These platforms greatly increase the accessibility of the stock market and the ability to create wealth for young investors. However, this recent surge in activity has dramatically affected the stock market in various ways and led to many negative outcomes for retail investors themselves. This Note uses several examples, surrounding the use of the platform Robinhood, to argue for action by the SEC and FINRA to implement additional protections for retail investors who utilize such platforms. Specifically, this Note calls for FINRA to modify its existing rules regarding account opening and approval and to provide a more detailed account approval process. This Note also argues for required education for retail investors looking to access certain complex and high-risk trading products

Comparison of Morphology Evolution of Ge(001) Homoepitaxial Films Grown by Pulsed Laser Deposition and Molecular Beam Epitaxy

Using a dual Molecular Beam Epitaxy (MBE)-Pulsed Laser Deposition (PLD) Ultra-High Vacuum chamber, we have conducted the first experiments under identical thermal, background, and surface preparation conditions to compare Ge(001) homoepitaxial growth morphology in PLD and MBE. We find that in PLD with low kinetic energy and in MBE the film morphology evolves in a similar fashion: initially irregularly shaped mounds form, followed by pyramidal mounds with edges of the square-base along directions; the film roughness and mound separation increase with film thickness. In PLD with high kinetic energy, well-defined pyramidal mounds are not observed and the morphology rather resembles that of an ion-etched Ge(001) surface. The areal feature density is higher for PLD films than for MBE films grown at the same average growth rate and temperature. Furthermore, the dependence upon film thickness of roughness and feature separation differ for PLD and MBE. We attribute these differences to the higher yield of defect generation by energetic species in PLD.Engineering and Applied Science

Comparison of Growth Morphology in Ge (001) Homoepitaxy Using Pulsed Laser Deposition and MBE

Differences in the homoepitaxy of Ge(001) are explored using a dual MBE/PLD deposition system. With identical substrate preparation, temperature calibration, background pressure and analysis, the system provides a unique comparison of the processes arising only from kinetic differences in the flux and at the surface. All films show mounded growth. At substrate temperatures below 200ºC, PLD films are smoother than MBE films, whereas they are similar at higher temperatures.Engineering and Applied Science

On the Phase Shift of Reflection High Energy Electron Diffraction Intensity Oscillations during Ge(001) Homoepitaxy by Molecular Beam Epitaxy

We have conducted a systematic investigation of the phase shift of the Reflection High Energy Electron Diffraction (RHEED) intensity oscillations during homoepitaxy of Ge(001) by molecular beam epitaxy for a wide range of diffraction conditions. Our results show that for small incidence angles with a beam azimuth several degrees away from the crystallographic symmetry direction, the phase is independent of incidence angle; however, it starts to shift once the incidence angle is high enough that the (004) Kikuchi line appears in the RHEED pattern. Moreover, under some conditions we observe the oscillations from only the Kikuchi feature and not from the specular spot, and the oscillatory behavior of the Kikuchi feature is almost out of phase with that of the specular spot. We conclude that the phase shift is caused by the overlap of the specular spot and the Kikuchi features, in contrast to models involving dynamical scattering theory for the phase shift. We discuss necessary conditions for avoiding interference.Engineering and Applied Science

The effects of fixation target size and luminance on microsaccades and square-wave jerks

A large amount of classic and contemporary vision studies require subjects to fixate a target. Target fixation serves as a normalizing factor across studies, promoting the field’s ability to compare and contrast experiments. Yet, fixation target parameters, including luminance, contrast, size, shape and color, vary across studies, potentially affecting the interpretation of results. Previous research on the effects of fixation target size and luminance on the control of fixation position rendered conflicting results, and no study has examined the effects of fixation target characteristics on square-wave jerks, the most common type of saccadic intrusion. Here we set out to determine the effects of fixation target size and luminance on the characteristics of microsaccades and square-wave jerks, over a large range of stimulus parameters. Human subjects fixated a circular target with varying luminance and size while we recorded their eye movements with an infrared video tracker (EyeLink 1000, SR Research). We detected microsaccades and SWJs automatically with objective algorithms developed previously. Microsaccade rates decreased linearly and microsaccade magnitudes increased linearly with target size. The percent of microsaccades forming part of SWJs decreased, and the time from the end of the initial SWJ saccade to the beginning of the second SWJ saccade (SWJ inter-saccadic interval; ISI) increased with target size. The microsaccadic preference for horizontal direction also decreased moderately with target size . Target luminance did not affect significantly microsaccades or SWJs, however. In the absence of a fixation target, microsaccades became scarcer and larger, while SWJ prevalence decreased and SWJ ISIs increased. Thus, the choice of fixation target can affect experimental outcomes, especially in human factors and in visual and oculomotor studies. These results have implications for previous and future research conducted under fixation conditions, and should encourage forthcoming studies to report the size of fixation targets to aid the interpretation and replication of their results