Dissociation phenomena in electron-beam sustained carbon dioxide lasers

A number of applications are emerging requiring efficient, long pulse, long-life sealed CO2 lasers. Examples include the proposed NASA and ESA wind lidars. Electron-beam sustained discharge devices are strong contenders. Unlike self-sustained discharges, e-beam sustenance readily provides efficient performance from large volume discharges and offers pulse lengths well in excess of the microsecond or so generally associated with self-sustained devices. In the case of the e-beam sustained laser, since the plasma is externally maintained and operated at electric field strengths less than that associated with the glow to arc transition, the discharges can be run even in the presence of strongly attacking species such as O2. Build up of large levels of attacking contaminants is nevertheless undesirable as their presence reduces the current drawn by the plasma and thus the pumping rate to the upper laser level. The impedance rise leads to a mismatch of the pulse forming network with a consequent loss of control over energy deposition, operating E/N, and gain. Clearly CO2 dissociation rates, the influence of dissociation products on the discharge and gain, and tolerance of the discharge to these products need to be determined. This information can then be used to assess co-oxidation catalyst requirements for sealed operation

A Phenomenological Analysis of Social Justice/Injustice on the lives of African-American High School Males

The purpose of this study is to analyze what high school African-American males perceive as significant influences that directly impact their academic achievement while attending a predominantly White suburban high school. This qualitative research study will utilize semi-structured case interviews to collect and analyze data gathered from among a criteria-based subgroup of African-American high school males. An examination of archival data such as student course selections, a review of high school Carnegie units earned and attempted, the availability of support resources and interventions, as well discipline and attendance reports will each provide evidence of the probable obstacles impacting the achievement of African-American male students in their local high school. The study will identify factors that are feasible in ameliorating the influence and perception of social justice/injustice while enrolled in high school

The Malingering of Psychotic Disorders

The phenomenon of malingered psychosis is examined through a review of the available literature. Possible motivations for malingering are discussed, and clinical indicators of feigned psychotic symptoms are reviewed. The methods discussed focus on the inpatient evaluation of suspected malingerers and include discussions of interview techniques and psychometric testing to supplement clinical impressions. A differential diagnosis is presented, and techniques for confronting a malingering patient are reviewed

Large mode radius resonators

Resonator configurations permitting operation with large mode radius while maintaining good transverse mode discrimination are considered. Stable resonators incorporating an intracavity telescope and unstable resonator geometries utilizing an output coupler with a Gaussian reflectivity profile are shown to enable large radius single mode laser operation. Results of heterodyne studies of pulsed CO2 lasers with large (11mm e sup-2 radius) fundamental mode sizes are presented demonstrating minimal frequency sweeping in accordance with the theory of laser-induced medium perturbations

It Is More Than Just the Message: Presentation Effects in Scoring Writing

People write for many reasons. Writing is used as a tool to record ideas and information, communicate with others, chronicle experiences, express one's feelings, persuade others, facilitate learning, create imagined worlds, and evaluate students' competence (Graham, 2006). In some instances, the only intended reader of a piece of writing is the author. Examples of such writing include diaries, to do lists, and lecture notes. In other instances, writing is meant to be both read and formally evaluated by others. This kind of writing can range from term papers to state and federal writing assessments to writing requirements included as part of college entrance applications

Risk management strategies using seasonal climate forecasting in irrigated cotton production: a tale of stochastic dominance

Decision‐making in agriculture is carried out in an uncertain environment with farmers often seeking information to reduce risk. As a result of the extreme variability of rainfall and stream‐flows in north‐eastern Australia, water supplies for irrigated agriculture are a limiting factor and a source of risk. The present study examined the use of seasonal climate forecasting (SCF) when calculating planting areas for irrigated cotton in the northern Murray Darling Basin. Results show that minimising risk by adjusting plant areas in response to SCF can lead to significant gains in gross margin returns. However, how farmers respond to SCF is dependent on several other factors including irrigators’ attitude towards risk.Crop Production/Industries, Risk and Uncertainty,