An experimental study of energy loss mechanisms and efficiency consideration in the low power dc arcjet

The potential utility of the low power dc arcjet in auxiliary propulsion was investigated. It was indicated that improvements in the areas of stability, energy efficiency, reliability, and electrode erosion are necessary to obtain a useful device. A water-cooled arcjet simulator was tested to investigate both the energy loss mechanisms at the electrodes and the stability of different conventional arcjet configurations in the presence of a vortex flow field. It is shown that in certain configurations only 25 to 30% of the input energy is lost to the electrodes. It is also shown that vortex stabilization is not difficult to obtain in many cases at the flow rates used and that a careful starting procedure is effective in minimizing electrode damage

Brief, Aerobic-surge Exercises for Effective Weight Loss: a Randomized, Controlled Trial

Background: Obesity is a growing disease and a consistently effective protocol is needed to reduce this epidemic. The purpose of this study was to determine if a frequent, brief (2-minute) high intensity aerobic exercise (≥75% max HR) was effective in reducing subjects’ weight (BMI) and girth sizes. Methods: A randomized, controlled trial lasting 60 days was conducted at three sites and forty-six subjects completed this study (mean age 39 ± 8 and BMI 32 ±2). The Experimental group was shown how to make movements such as riding a stationary bicycle or lifting dumbbells into an ‘Aerobic-surge’ exercise at or above 75% of calculated maximum heart rate. Control subjects were simply told to “exercise more.” No dietary changes were made for either group. The dependent variables were changes in weight and ‘body summation’ of 10 girth measurements. A 2x2 ANOVA was used to calculate differences. A post-hoc analysis of changes in BMI was also calculated. Results: There was a significant difference between groups (P<0.0001). The mean change of the groups were as follows: Experimental (N=23) mean reductions = -18.lbs and -18.7” vs. Control (N=23) mean changes = +1.3.lbs and +1.3.” Conclusion: The repeated, brief (2-minute) aerobic-surge exercise protocol, performed 4.2 times/day was effective in reducing subjects’ weight and body circumferences. Isolated tests of body composition showed that change were primarily in body fat. This could be a tool in reducing the obesity epidemic. The Aerobic-surge exercise was effective without a dietary changes. Retrospectively Registered Trial: ISRCTN 17326333

Tax and Policy Implications of Changes to Reporting Requirements for Construction Services

[Excerpt] New York and other states could increase revenue and improve their tax systems by requiring information reporting for all payments by businesses for construction services, utilizing a form similar to the Federal form 1099. The state could also advance other important policy goals including an increase in the fairness of the tax system and a reduction of the misclassification of workers as independent contractors

Hollow cathodes in high pressure arc discharges

An orified hallow cathode was tested at high pressure to improve lifetime and efficiency in arcjet thrusters. It is indicated that the arc would not operate with emission from the insert above 200 torr in nitrogen regardless of insert material, orifice diameter, or gas flow direction. Emission occurred from the insert in argon and xenon although it could not be ascertained whether diffuse or spot emission existed within the cathode. Over the extended range of configurations and operating parameters explored the desired diffuse emission mode could not be obtained at high enough pressures for orified hollow cathodes to operate in the range which is considered for arcjet applications

The Long Civil War: New Explorations of America\u27s Enduring Conflict

Reviewer Thomas F. Curran writes that The Long Civil War: New Explorations of America’s Enduring Conflict, edited by John David Smith and Raymond Arsenault provides an “expansive spectrum of scholarship being produced” on the Civil War era “that employs a broader chronological understanding of the war.” The collected essays investigate several aspects of the Civil War era—antebellum antislaveryism, Civil War commanders and their tactics, disabled veterans and veteran suicide, historical memory of Lincoln, including that of President Dwight D. Eisenhower, the historiography of slavery, and the Civil War era in film culture. The book “provides a taste” of the sweeping chronological approach to Civil War studies

Influência sobre as políticas de disciplina escolar: Variação de acordo com a governança, contextos escolares e tempo

Little research explores the relative influence of various stakeholders on school discipline policy. Using data from the SASS and ordered logistic regression, this study explores such influence while assessing variation across schools types and changes over time. Principals consistently rate themselves and teachers as the most influential stakeholders over setting school discipline policy. The proportion of racial minorities in a school predicts greater influence from higher levels of governance while charter schools report less. Increases in influence of principals and teachers over time are documented. The results may inform both policymakers and practitioners as they work to improve equitable disciplinary outcomes for students.Pocos estudios exploran la influencia relativa de varias partes interesadas en las políticas de disciplina escolar. Utilizando datos del SASS y la regresión logística ordenada, este estudio explora esta influencia al evaluar la variación entre los tipos de escuelas y los cambios a lo largo del tiempo. Los directores constantemente califican a sí mismos y a los maestros como los interesados más influyentes en establecer la política de disciplina escolar. La proporción de minorías raciales en una escuela predice una mayor influencia de los niveles superiores de gobierno, mientras que las escuelas autónomas informan menos. Se documentan aumentos en la influencia de los directores y docentes a lo largo del tiempo. Los resultados pueden informar tanto a los legisladores como a los profesionales a medida que trabajan para mejorar los resultados disciplinarios equitativos para los estudiantes.Poucos estudos exploram a influência relativa de várias partes interessadas sobre as políticas de disciplina escolar. Usando dados do SASS e ordenou regressão logística, este estudo explora essa influência ao avaliar a variação entre os tipos de escolas e mudanças ao longo do tempo. Os directores classificam-se de forma consistente e os professores como as partes interessadas mais influentes sobre a definição da política de disciplina escolar. A proporção de minorias raciais em uma escola prevê uma maior influência dos níveis mais altos de governança, enquanto as escolas charter relatam menos. Aumenta a influência dos diretores e professores ao longo do tempo. Os resultados podem informar tanto os formuladores de políticas como os profissionais, na medida em que trabalham para melhorar os resultados disciplinares equitativos para os alunos