The degradation of alzak by short wavelength ultraviolet radiation

The changes in reflectance of thermal aluminum coating samples exposed to different irradiating utraviolet wavelengths are discussed. It is shown that the coating is damaged faster and further by 180 to 210 in radiation than by Lyman alpha radiation. On an equivalent incident energy basis, Lyman alpha does less damage than 180 to 210 nm radiation. Above 300 nm no degradation is observed for long exposures and below 300 nm increasing degradation with decreasing wavelength is found. It is concluded that Lyman alpha radiation need not be included in laboratory testing of this thermal coating for spacecraft structures

An Observational Diagnostic for Ultraluminous X-Ray Sources

We consider observational tests for the nature of Ultraluminous X-ray sources (ULXs). These must distinguish between thermal-timescale mass transfer on to stellar-mass black holes leading to anisotropic X-ray emission, and accretion on to intermediate-mass black holes. We suggest that long-term transient behavior via the thermal-viscous disk instability could discriminate between these two possibilities for ULXs in regions of young stellar populations. Thermal-timescale mass transfer generally produces stable disks and persistent X-ray emission. In contrast, mass transfer from massive stars to black holes produces unstable disks and thus transient behavior, provided that the black hole mass exceeds some minimum value. This minimum mass depends primarily on the donor mass and evolutionary state. We show that it exceeds 50 solar masses for a large fraction (greater than 90%) of the mass-transfer lifetime for the most likely donors in young clusters. Thus if long-term monitoring reveals a large transient fraction among ULXs in a young stellar population, these systems would be good candidates for intermediate-mass black holes in a statistical sense; information about the donor star is needed to make this identification secure in any individual case. A transient ULX population would imply a much larger population of quiescent systems of the same type.Comment: 4 pages, 2 figure, ApJ Letters, in press (correct figure 2 included in this version

Chapter 2: Navigating the mentoring process in a research-based teacher development project: A situated learning perspective

In this article, the authors investigate key aspects of a 2-year study of mentoring within a reform-based teacher development project, explore the various mentor relationships, and theorize about key events, tensions, and dynamics that resulted in an unexpected sense of community among project stakeholders as a direct result of mentoring. Data for this article describe the impact of teacher mentoring within the Assessment Initiative for Middle School Physical Education (AIMS-PE) project. AIMS-PE was a multi-year Center for Disease Control grant funded project with goals including assisting in-service teachers to examine and reframe their assessment practices and to increase their students. knowledge and behaviors of physical activity. Initiation and development of positive mentoring relationships among participating teachers and their mentors was a major component of this effort, providing necessary support and encouragement to meet project objectives. Also, the authors explore participants\u27 experiences in the project to better understand the influences of teacher mentoring that contributed to the development of a sense of community

B782: Performance Evaluations of Potato Clones and Varieties in the Northeastern States 1981

Cooperative variety trials were conducted at 33 locations to determine field, storage, and processing behavior of selected potato clones and varieties when grown under soil, climatic, and cultural conditions common to the potato growing areas of 12 cooperating States and the Province of New Brunswick, Canada. These trials are all contributions to Regional Project NE107 entitled, Breeding and Evaluation of New Potato Clones in the Northeast Area.https://digitalcommons.library.umaine.edu/aes_bulletin/1123/thumbnail.jp

B814: Performance Evaluations of Potato Clones and Varieties in the Northeastern States - 1985

New potato clones and varieties must be tested against commercially accepted cultivars to determine If they possess advantages over existing varieties. Possible Improvements over the existing varieties could Include greater disease resistance or tolerance, higher yield, more uniform tuber size distribution, Improved storagability, good processing characteristics, etc. Often new cultivars are sought to fill local special-purpose needs. The cooperative potato variety trials reported In this bulletin were conducted to provide Information on the performance, adaptation, and performance stability of new potato clones under a wide range of geographic, climatic, soil, and cultural conditions. These tests are contributions to Regional Project NE-107 entitled, Breeding and Evaluation of New Potato Clones for the Northeast. The objectives of this regional project are: 1). To develop high quality, widely adapted, productive, pest resistant potato varieties for use In the northeast; 2). To determine regional performance, quality, and storage characteristics for promising potato clones and new varieties; 3). To evaluate promising clones and varieties for special-purpose needs such as pest outbreaks, processing, export, specialized market opportunities and/or production situations; 4). To develop management practices such as plant population, fertilizer rate, disease, weed, and Insect control strategies that will I Improve the yield and/or quality of promising clones. Data presented In this report primarily address objectives 2 and 3.https://digitalcommons.library.umaine.edu/aes_bulletin/1118/thumbnail.jp