73 research outputs found
A new laboratory for terahertz characterization of cosmic analog dusts
Two efforts have been underway to enable the laboratory study of cosmic analogs dusts in the frequency range 60--2000 GHz. They are: (1) the construction of a novel compact Fourier Transform Spectrometer (FTS) design coupled to a dry 4-K cryostat which houses a cooled sample exchanger (filter wheel) and a bolometer. (2) The production of Mg- and Fe-rich silicate dusts using sol-gel methodsvarious tests to determine their physical and chemical propertiesembedding of samples in LDPE pellets for insertion into the novel FTS. This presentation will focus on the current status of the apparatus and data from its first few months of use
Tests of a Novel Technique for Finding Galaxies in Millimeter Wavelength Maps
The study of very distant “dusty” galaxies whose visible light is obscured by cosmic dust is a developing field in astronomy. To discover such galaxies, images of the sky are made with telescopes sensitive to millimeter-wavelength light. Because these images are inherently low in signal-to-noise, special image processing techniques are needed to reliably identify galaxies in them. Usually, a software “filter” is applied to a sky image in order to better distinguish galaxies from noise. We have developed a novel filter that, in principle, performs better than the standard filter used in the astronomical community. Our study, which involved testing this new filter, is presented here. This is a continuation of an improvement over work previously presented in 2010
A Graphical Introduction to Special Relativity Based on a Modern Approach to Minkowski Diagrams
We present a graphical method that can be used to learn/teach Einstein’s special theory of relativity. The “Minkowski diagram”, developed in 1908 by Hermann Minkowski, has long been recognized as an effective graphical tool for introducing special relativity. In our study, we adapted and modernized this graphical method in a way that would help current college students progress from Galilean transformations (based on Newton\u27s Three Laws of Motion) to the kinematics of relativity and other key results. This study has revealed new ways to apply Minkowski diagrams to well known problems in relativity. Here, we will introduce our graphical technique and apply it to the resolution of the famous the twin paradox
Day of the Week Effect of Stock Returns: Empirical Evidence from Colombo Stock Exchange
Many empirical studies have been carried out both in the developed and developing economies to test the presence of anomalies in stock returns and volatility. The most commonly tested seasonal anomalies are day of the week effect, month of the year effect, holiday effect, Monday effect and Friday effect. Previous studies strongly support the existence of seasonal anomalies. Existence of seasonal anomalies let the investors to earn abnormal returns by trading on past information. This study attempts to test whether the day of the week effect is present in the stock returns of the Colombo Stock Exchange. For this purpose, stock returns based on ASPI for the period of 2002 to 2011 with 2390 observation are taken into account. The day of the week effect hypothesis is tested using both OLS model and GARCH (1,1) model. The research provides strong evidence to support the day of the week effect. Furthermore, there is a Thursday, Wednesday and Friday effect in the stock returns. Thus, investors can earn abnormal returns by trading on a strategy based on past information. It is recommended to buy stock on Mondays and Tuesdays and sell them on Wednesdays, Thursdays and Fridays to earn abnormal returns.DOI: http://dx.doi.org/10.4038/kjm.v1i2.6451 Kelaniya Journal of Management Vol.1(2) 2012:16-27</p
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