Noise Pollution? What\u27s the solution?: Understanding Traffic Noise Pollution in Gettysburg, Pennsylvania

Noise pollution can be damaging to a community by impacting its atmosphere as well as the health of its residents, local quality of life, and local economy. Our study sought to gain insight into the level of noise pollution in Gettysburg, both in-town and on the Gettysburg College campus, and how noise pollution may be affecting the local residents and students. We selected 9 sampling sites, 6 in-town and 3 on the college campus, and measured the noise pollution in dBA with portable sound meters three days a week and three times a day over a three week period. Our data showed no major trends in terms of time of day or day of the week, but there were clear differences in noise pollution levels between the different sites in that town sites were generally louder than on campus sites. Noise pollution in town was often louder than 70 dBA, the noise threshold that indicates possible hearing damage overtime set by the World Health Organization. Gettysburg has recently enacted a noise ordinance; our study suggests the Borough possibly could do more to mitigate traffic noise by repairing roads and manipulating road design

Low-energy local density of states of the 1D Hubbard model

We examine the local density of states (DOS) at low energies numerically and analytically for the Hubbard model in one dimension. The eigenstates represent separate spin and charge excitations with a remarkably rich structure of the local DOS in space and energy. The results predict signatures of strongly correlated excitations in the tunneling probability along finite quantum wires, such as carbon nanotubes, atomic chains or semiconductor wires in scanning tunneling spectroscopy (STS) experiments. However, the detailed signatures can only be partly explained by standard Luttinger liquid theory. In particular, we find that the effective boundary exponent can be negative in finite wires, which leads to an increase of the local DOS near the edges in contrast to the established behavior in the thermodynamic limit.Comment: 6 pages, 4 figures, more information can be found at http://www.physik.uni-kl.de/eggert/papers/index.htm

Stripes of Partially Fluorinated Alkyl Chains: Dipolar Langmuir Monolayers

Stripe-like domains of Langmuir monolayers formed by surfactants with partially fluorinated lipid anchors (F-alkyl lipids) are observed at the gas-liquid phase coexistence. The average periodicity of the stripes, measured by fluorescence microscopy, is in the micrometer range, varying between 2 and 8 microns. The observed stripe-like patterns are stabilized due to dipole-dipole interactions between terminal -CF3 groups. These interactions are particularly strong as compared with non-fluorinated lipids due to the low dielectric constant of the surrounding media (air). These long-range dipolar interactions tend to elongate the domains, in contrast to the line tension that tends to minimize the length of the domain boundary. This behavior should be compared with that of the lipid monolayer having alkyl chains, and which form spherical micro-domains (bubbles) at the gas-liquid coexistence. The measured stripe periodicity agrees quantitatively with a theoretical model. Moreover, the reduction in line tension by adding traces (0.1 mol fraction) of cholesterol results, as expected, in a decrease in the domain periodicity.Comment: 20 pages, 4 fig

Identification of the relationship between Chinese Adiantum reniforme var. sinense and Canary Adiantum reniforme

© 2014 Wang et al.; licensee BioMed Central. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated