The von Karman equations, the stress function, and elastic ridges in high dimensions

The elastic energy functional of a thin elastic rod or sheet is generalized to the case of an M-dimensional manifold in N-dimensional space. We derive potentials for the stress field and curvatures and find the generalized von Karman equations for a manifold in elastic equilibrium. We perform a scaling analysis of an M-1 dimensional ridge in an M = N-1 dimensional manifold. A ridge of linear size X in a manifold with thickness h << X has a width w ~ h^{1/3}X^{2/3} and a total energy E ~ h^{M} (X/h)^{M-5/3}. We also prove that the total bending energy of the ridge is exactly five times the total stretching energy. These results match those of A. Lobkovsky [Phys. Rev. E 53, 3750 (1996)] for the case of a bent plate in three dimensions.Comment: corrected references, 27 pages, RevTeX + epsf, 2 figures, Submitted to J. Math. Phy

Data Collection from a Sensor Network using a Quadcopter

The purpose of this project is to implement an automated data collection drone that fly’s to wireless sensor nodes and collects measurement data. This is intended for sensor networks that are placed too far apart to communicate wirelessly or need to operate on very low power in remote locations. An off the shelf quad copter was outfitted with an Arduino and a ZigBee for collecting data from nodes and storing the data on a micro SD card through openlog. The drone uses a GPS module with provided coordinates for navigation. Each node is constructed using an Arduino, a ZigBee and a temperature sensor

Decisions, Decisions: Analyzing College Choice Amongst NCAA Division II Transfer and Non-Transfer Athletes

Abstract Many pundits and fans within college sport have exhausted an inordinate amount of time analyzing the impact of recruiting in intercollegiate athletics amidst recent regulatory changes within the National Collegiate Athletic Association (NCAA). The most recent changes to Division I transfer regulations have introduced a level of uncertainty about the future of college athletics. While these changes may garner significant attention for Division I revenue sport programs, recruiting plays a critical role in across all levels of competition (Nixon, et al., 2021). Yet, scant research has been conducted to determine which factors are most influential in an NCAA Division II athlete’s decision to attend an institution, including those engaging in the transfer process. Therefore, a closer examination of the college choice factors of Division II transfer and non-transfer athletes is warranted. Using descriptive statistics, results suggested that academic factors were most important to Division II athletes in making their college choice decisions. T-test results indicated significant differences in the influence of specific college choice items for transfers and non-transfers, most notably athletic facilities and outside influences. This study was designed to assist college athletes, coaches, and administrators at Division II institutions to better understand the areas that significantly influence a college athlete\u27s decision to attend a particular institution, while also expanding the breadth of college choice research

Self-consistent calculation of electric potentials in Hall devices

Using a first-principles classical many-body simulation of a Hall bar, we study the necessary conditions for the formation of the Hall potential: (i) Ohmic contacts with metallic reservoirs, (ii) electron-electron interactions, and (iii) confinement to a finite system. By propagating thousands of interacting electrons over million time-steps we capture the build-up of the self-consistent potential, which resembles results obtained by conformal-mapping methods. As shown by a microscopic model of the current injection, the Hall effect is linked to specific boundary conditions at the particle reservoirs.Comment: 6 pages, 7 figure

Genomic function during the lampbrush chromosome stage of amphibian oogenesis

Throughout its lengthy developmental history the disposition of the genetic material in the amphibian oocyte nucleus differs from that in other cell types. The chromosomes in the oocyte nucleus, arrested for the whole of oogenesis at the prophase of the first meiotic division, are known to contain at least the tetraploid amount of DNA.(1,2) Oogenesis in amphibia requires months or even years to complete, depending on the species

Dust and gas emission from cometary nuclei: the case of comet 67P/Churyumov-Gerasimenko

Comets display with decreasing solar distance an increased emission of gas and dust particles, leading to the formation of the coma and tail. Spacecraft missions provide insight in the temporal and spatial variations of the dust and gas sources located on the cometary nucleus. For the case of comet 67P/Churyumov-Gerasimenko (67P/C-G), the long-term observations from the Rosetta mission point to a homogeneous dust emission across the entire illuminated surface. Despite the homogeneous initial distribution, a collimation in jet-like structures becomes visible. We propose that this observation is linked directly to the complex shape of the nucleus and projects concave topographical features into the dust coma. To test this hypothesis, we put forward a gas-dust description of 67P/C-G, where gravitational and gas forces are accurately determined from the surface mesh and the rotation of the nucleus is fully incorporated. The emerging jet-like structures persist for a wide range of gas-dust interactions and show a dust velocity dependent bending.Comment: 17 pages, with 7 figures. To appear in Advances in Physics X (2018

Chestnut Trees and Farm at Jas de Bouffan

The Cézanne family’s country home outside Aix-en-Provence appeared often in the artist’s work. Called Jas de Bouffan (“sheepfold of the winds”), the property consisted of an 18th-century manor house with surrounding gardens and a farm. Just out of sight of this view, beyond the farm buildings at right, loomed another favorite motif: the shimmering Montagne Sainte-Victoire. In 1881 Paul Cézanne built a studio at Jas de Bouffan and for the next eighteen years spent much of his time painting nearby landscapes. This composition features an allée of chestnut trees seen from the garden behind the house. Cézanne massed the trees at left, covering the yellow stucco planes of the house with a blanket of spring foliage. The trees, lawn, and sky are rendered as organized patches of color whose surface rhythms embrace the interlocking geometric shapes of the house, wall, and farm buildings. ca. 1886https://digitalcommons.risd.edu/risdmuseum_channel/1012/thumbnail.jp

Theory of the quantum Hall effect in graphene

We study the quantum Hall effect (QHE) in graphene based on the current injection model. In our model, the presence of disorder, the edge-state picture, extended states and localized states, which are believed to be indispensable ingredients in describing the QHE, do not play an important role. Instead the boundary conditions during the injection into the graphene sheet, which are enforced by the presence of the Ohmic contacts, determine the current-voltage characteristics.Comment: 4 pages, 3 figures, rewritten, role of contacts for boundary conditions in small device