Time Periodic Perturbations of Quantum Systems

We discuss a method of calculating the mean energy of a quantum system if the latter is subjected to time periodic perturbations. This, e.g., includes the possibility of determining shapes of spectral lines for an arbitrary distribution of nonperturbed energy levels. The method is studied on a system of order 2 whose spectral line is exactly lorentzian. We prove that the next to lowest approximation reproduces this form exactly. © 1979, Walter de Gruyter. All rights reserved

Generic Satellite Monitoring Expert System

Air Force Satellite Operations is undergoing major changes. Operators no longer receive detailed satellite training, instead they are taught basic fundamentals of satellite operations and expected to control multiple multimillion dollar satellites. The need is clear. An efficient and economical automated system is necessary to assist the satellite operator in his daily tasks of maintaining these DOD priority resources. Satellite intelligent controllers been under R&D since the early 1980s to this need. These systems, however, have focused on the control of one constellation of satellites. In a military striving for efficiency and lower costs, developing a unique intelligent controller for each satellite constellation is unaffordable. This research provided support for the concept of a generic satellite intelligent controller, through the development of a prototype expert system. This capability would allow a generic rule-base to operate and maintain multiple satellite systems. The initial prototype detected anomalies on one subsystem of two different satellites. After the third satellite prototype was created, a third satellite was analyzed to show support for the viability of the satellite prototype. More research is necessary, but this thesis has created support for the concept of generic satellite controller and has laid the foundation for future extensions

Micro- and nanotechnology for cell biophysics

Procedures and methodologies used in cell biophysics have been improved tremendously with the revolutionary advances witnessed in the micro- and nanotechnology in the last two decades. With the advent of microfluidics it became possible to reduce laboratory-sized equipment to the scale of a microscope slide allowing massive parallelization of measurements with extremely low sample volume at the cellular level. Optical micromanipulation has been used to measure forces or distances or to alter the behavior of biological systems from the level of DNA to organelles or entire organisms. Among the main advantages is its non-invasiveness, giving researchers an invisible micro-hand to “touch” or “feel” the system under study, its freely and very often quickly adjustable experimental parameters such as wavelength, optical power or intensity distribution. Atomic force microscopy (AFM) opened avenues for in vitro biological applications concerning with single molecule imaging, cellular mechanics or morphology. As it can operate in liquid environment and at human body temperature, it became the most reliable and accurate nanoforce-tool in the research of cell biophysics. In this paper we review how the above three techniques help increase our knowledge in biophysics at the cellular level

Reconciling Geophysical and Petrological Estimates of the Thermal Structure of Southern Tibet

The thermal structure of the Tibetan plateau—the largest orogenic system on Earth—remains largely unknown. Numerous avenues provide fragmentary pressure/temperature information, both at the present (predominantly informed though geophysical observation) and on the evolution of the thermal structure over the recent past (combining petrological, geochemical, and geophysical observables). However, these individual constraints have proven hard to reconcile with each other. Here, we show that models for the simple underthrusting of India beneath southern Tibet are capable of matching all available constraints on its thermal structure, both at the present day and since the Miocene. Many parameters in such models remain poorly constrained, and we explore the various trade-offs among the competing influences these parameters may have. However, three consistent features to such models emerge: (i) that present-day geophysical observations require the presence of relatively cold underthrust Indian lithosphere beneath southern Tibet; (ii) that geochemical constraints require the removal of Indian mantle from beneath southern Tibet at some point during the early Miocene, although the mechanism of this removal, and whether it includes the removal of any crustal material, is not constrained by our models; and (iii) that the combination of the southern extent of Miocene mantle-derived magmatism and the present-day geophysical structure and earthquake distribution of southern Tibet require that the time-averaged rate of underthrusting of India relative to central Tibet since the middle Miocene has been faster than it is at present

The Cow That Stole Christmas: Framing the First U.S. Mad Cow Crisis

The discovery of bovine spongiform encephalopathy (BSE) in the United States made an impact on the beef industry. Determining how the BSE outbreak was framed by the news media is significant because research indicates that media shape public perceptions. This study examined how several key newspapers framed the 2003 outbreak of BSE in the United States. Determining how the media framed this issue can help communicators ensure bias-free media coverage of similar issues in the future. The study followed established framing analysis categories identified from the literature. There were 149 articles identified in The Washington Post, The Seattle Times, and USA Today for investigation in this study. Findings showed that the BSE issue was framed as an industry crisis and that the tone of the articles and headlines portrayed the beef industry negatively. When compared to the other two newspapers, USA Today framed the issue differently, with economic calamity being the dominant frame. The most heavily cited sources in the articles were government officials. This study recommends that media professionals avoid framing an issue for the public, focusing instead on reporting news in an objective and unbiased manner. Further research is recommended to examine the impact of tone and frame on specific audiences