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Full-Text Articles in Physics
Experiments On De Vries Liquid Crystals: A Software Approach, Austin Havens
Experiments On De Vries Liquid Crystals: A Software Approach, Austin Havens
Physics
This paper describes two programs I developed to facilitate the study of liquid crystals. The first program is a graphical user interface to increase the accuracy of the birefringence measurements , which relates to their orientational order, by using a camera. The second program was designed to help study the effects of time varying fields on liquid crystals by matching data from a recorded video to oscilloscope data in order to attach data from image analysis to the voltage applied to the cell.
Search For Dark Matter Annihilation In M5, Daniel Jackson
Search For Dark Matter Annihilation In M5, Daniel Jackson
Physics
We analyzed the Messier 5 (M5) globular cluster for dark matter annihilation using data from VERITAS (Very Energetic Radiation Imaging Telescope Array System) to improve the flux upper limit previously done by Michael McCutecheon. We used updated software and lower energy thresholds. VERITAS consists of four ground-based gamma-ray telescopes located at the Fred Lawrence Whipple Observatory in southern Arizona. Thirty-five 20 minute observations of M5 from VERITAS are used in our analysis. The observations were collected from February to March in 2009, for a total exposure time of 10.63 hours. Gamma-rays from dark matter annihilation were not found,
but better …
Reflectivity Of A Cholesteric Liquid Crystal, Justin Lawson
Reflectivity Of A Cholesteric Liquid Crystal, Justin Lawson
Physics
In this paper we investigate the light properties of a chiral liquid crystal or a crystal for which the director angle relative to some fixed axis changes as a function of the crystal depth. Sometimes a dopant can introduce a chirality or "twist" in a nematic liquid crystal. For such cases of non-linear depth dependence (where chirality is determined by a diffusion equation) we may use this research to work backwards from a crystal's light properties to intensity and duration of dopant exposure.