Three-axis electron-beam test facility

An electron beam test facility, which consists of a precision multidimensional manipulator built into an ultra-high-vacuum bell jar, was designed, fabricated, and operated at Lewis Research Center. The position within the bell jar of a Faraday cup which samples current in the electron beam under test, is controlled by the manipulator. Three orthogonal axes of motion are controlled by stepping motors driven by digital indexers, and the positions are displayed on electronic totalizers. In the transverse directions, the limits of travel are approximately + or - 2.5 cm from the center with a precision of 2.54 micron (0.0001 in.); in the axial direction, approximately 15.0 cm of travel are permitted with an accuracy of 12.7 micron (0.0005 in.). In addition, two manually operated motions are provided, the pitch and yaw of the Faraday cup with respect to the electron beam can be adjusted to within a few degrees. The current is sensed by pulse transformers and the data are processed by a dual channel box car averager with a digital output. The beam tester can be operated manually or it can be programmed for automated operation. In the automated mode, the beam tester is controlled by a microcomputer (installed at the test site) which communicates with a minicomputer at the central computing facility. The data are recorded and later processed by computer to obtain the desired graphical presentations

More Care and Less Pay: The Phenomenon of Low Wages Among Care Occupations

This research examines the phenomenon of care occupations paying less than other occupations with similar levels of human capital investment. The paper evaluates the high concentration of women, especially Black women, the resulting wage penalties, social closure theory, temporal flexibility, and positive externalities as possible explanations for this problem. Potential solutions like raising the minimum wage and subsidizing education for care workers are also addressed

A cosmic gamma-ray burst on May 14, 1975

A cosmic gamma-ray burst is reported that occurred at 29309.11 s UTC, May 14, 1975. The burst was detected at an atmospheric depth of 4 g/sq cm residual atmosphere with the University of California double scatter gamma-ray telescope launched on a balloon from Palestine, Texas at 1150 UTC, May 13, 1975. The burst was observed both in the single scatter mode by the top liquid scintillator tank in anti-coincidence with the surrounding plastic scintillator and in the double scatter mode from which energy and directional information are obtained. The burst is 24 standard deviations above the background for single scatter events. The total gamma-ray flux in the burst, incident on the atmosphere with photon energy greater than 0.5 MeV, is 0.59 + or - 0.15 photons/sq cm. The initial rise time to 90% of maximum is 0.015 + or - 0.005 s and the duration is 0.11 s. Time structure down to the 5 ms resolution of the telescope is seen. The mean flux over this time period is 5.0 + or - 1.3 photons/sq cm/s and the maximum flux is 8.5 + or - 2.1 photons/sq cm/s

The Social Psychology of Identity and Intergroup Conflict: From Theory to Practice

Cataloged from PDF version of article.This paper reviews the seminal theories of social psychology which have guided scholarship on inter-group conflicts and describes how these theories have been used by conflict resolution practitioners to design Track Two diplomacy initiatives among citizens in conflict zones. The authors hope that such a review will provide scholars of conflict resolution and international politics with a better understanding of how complex social theories are adapted for use in the applied world, and how gaps between theory and practice can be identified and addressed. The paper begins with an overview of three of the main theoretical contributions of social psychology to the problem of inter-group conflict: social identity theory, stereotyping and prejudice, and contact theory. We then review how these theories have been applied by conflict resolution specialists in international and ethnic conflicts as they have sought to moderate intergroup hostilities in conflict zones. The paper concludes with an analysis of the gaps between theory and practice, namely: theory of change gap, transfer strategies gap, and unit of analysis gap. Finally, based on the reviewed social psychology research, the article makes policy recommendations about how these gaps between theory and practice can be narrowed. © 2011 International Studies Association

1/t pressure and fermion behaviour of water in two dimensions

A variety of metal vacuum systems display the celebrated 1/t pressure, namely power-law dependence on time t, with the exponent close to unity, the origin of which has been a long-standing controversy. Here we propose a chemisorption model for water adsorbates, based on the argument for fermion behaviour of water vapour adsorbed on a stainless-steel surface, and obtain analytically the power-law behaviour of pressure, with an exponent of unity. Further, the model predicts that the pressure should depend on the temperature T according to T^(3/2), which is indeed confirmed by our experiment. Our results should help elucidate the unique characteristics of the adsorbed water.Comment: 11 pages, 4 figure

Differential Item Functioning Amplification and Cancellation in a Reading Test

When testlet effects and item idiosyncratic features are both considered to be the reasons of DIF in educational tests using testlets (Wainer & Kiely, 1987) or item bundles (Rosenbaum, 1988), it is interesting to investigate the phenomena of DIF amplification and cancellation due to the interactive effects of these two factors. This research applies the multiple-group testlet item response theory model developed by Li et al. (2006) to examine in detail different situations of DIF amplification and cancellation at the item and testlet level using testlet characteristic curve procedures with signed/unsigned area indices and logistic regression. Accessed 9,037 times on https://pareonline.net from October 26, 2009 to December 31, 2019. For downloads from January 1, 2020 forward, please click on the PlumX Metrics link to the right

Dynamics and energetics of the South Pacific Convergence Zone during FGGE SOP-1 and South Pacific Convergence Zone and global-scale

Significant accomplishments (papers published, conference presentations, and education degrees) are presented. The focus of the current research is outlined. Plans for the coming year are discussed briefly