Single acting translational/rotational brake

A brake system is provided that applies braking forces on surfaces in both the translational and rotational directions using a single acting self-contained actuator that travels with the translational mechanism. The brake engages a mechanical lock and creates a frictional force on the translational structure preventing translation while simultaneously creating a frictional torque that prevents rotation of the vertical support. The system may include serrations on the braking surfaces to provide increased braking forces

LaRC design analysis report for National Transonic Facility for 304 stainless steel tunnel shell. Volume 4S: Thermal analysis

For abstract, see N76-33552

LaRC design analysis report for National Transonic Facility for 304 stainless steel tunnel shell. Volume 7S: Special studies

For abstract, see N76-33552

LaRC design analysis report for national transonic facility for 9% nickel tunnel shell. Volume 7: Special studies

For abstract, see N76-33543

LaRC design analysis report for National Transonic Facility for 9% nickel tunnel shell. Volume 3: Finite element analysis of plenum region including side access reinforcement, side access door and angle of attack penetration

For abstract, see N76-33543

Online Learning and Mentors: Addressing the Shortage of Rural Special Educators Through Technology and Collaboration

This article describes a promising model in comprehensive special education personnel preparation to support the recruitment and retention of special education teachers in rural areas. The approach draws on several bodies of research to include best practices for teacher education, online service delivery, collaboration among key stakeholders, and the development of strong mentoring and induction programs. The implementation plan, based on evidence-based practice in special education and online learning, is presented. A key element of this plan is developing and maintaining strong relationships among rural districts, the state department of education, and higher education

Grasslands of the Great Plains: Their Nature and Use

This book is the result of a long-felt need by the authors and their students for a comprehensive survey of the numerous studies that have been made on plains grasslands. From southern Texas far into Saskatchewan the mid and short grasses form a magnificent prairie nearly 2,500 miles in length and approximately 400 miles wide. Kinds of communities, their composition, nature, significance and uses are fully described. Such information is of value not only to students, range technicians, and other professional conservationists, but also to ranchers and other land owners-in fact, to anyone interested in the economy of our midwestern grasslands. The damaging effects of drought on forage production in this unstable climate and the restoration of the plant cover are of such great importance that they have been given special attention. Climate, soils, and. the proper use of the forage for its sustained production are described. A third of a century of study and experimentation in plains grassland by the authors permits accurate description and interpretation. Important studies that have been made on the vegetation since the coming of the white man to the present day are reviewed. Early investigations have been recorded in papers, bulletins and books, many of which are now out of print or difficult of access. Therefore permission was asked and promptly given by the Carnegie Institution of Washington, Duke University Press, Ecological Monographs, Ecology, and several other journals to re-use materials originally furnished by the authors. Such sources are carefully cited in the text. Only by such cooperation has this book been made possible. This great prairie land has been thoroughly examined as to its way of life both above ground and deep into the soil, which it has helped to build and so efficiently protects. Extensive, long-time investigations have elucidated many problems. The scope of the work has been broadened and deepened by the aid of a large number of advanced students who have sought graduate study in this field. To them, many of whom are today leaders in conservation of range management or in teaching a new generation of students the values of ecology in our economy, we are deeply grateful for their interest and cooperation. Two of them are so familiar with the grasslands of Texas and New Mexico, respectively, that each has contributed a chapter to this book. Both common and scientific names of grasses are according to Hitchcock and Chase (1950) revised Manual of the Grasses of the United States. Other scientific names follow Gleason\u27s New Britton and Brown Illustrated Flora (1952) or Harrington\u27s Manual of the Plants of Colorado (1954). Common names are nearly all according to the second edition (1913) of Britton and Brown or the second edition of Standardized Plant Names (1942). 404 page

Symmetry of re-entrant tetragonal phase in Ba1-xNaxFe2As2: Magnetic versus orbital ordering mechanism

Magneto-structural phase transitions in Ba1-xAxFe2As2 (A = K, Na) materials are discussed for both magnetically and orbitally driven mechanisms, using a symmetry analysis formulated within the Landau theory of phase transitions. Both mechanisms predict identical orthorhombic space-group symmetries for the nematic and magnetic phases observed over much of the phase diagram, but they predict different tetragonal space-group symmetries for the newly discovered re-entrant tetragonal phase in Ba1-xNaxFe2As2 (x ~ 0.24-0.28). In a magnetic scenario, magnetic order with moments along the c-axis, as found experimentally, does not allow any type of orbital order, but in an orbital scenario, we have determined two possible orbital patterns, specified by P4/mnc1' and I4221' space groups, which do not require atomic displacements relative to the parent I4/mmm1' symmetry and, in consequence, are indistinguishable in conventional diffraction experiments. We demonstrate that the three possible space groups are however, distinct in resonant X-ray Bragg diffraction patterns created by Templeton & Templeton scattering. This provides an experimental method of distinguishing between magnetic and orbital models

Mentors Increasing Special Education Retention

Lack of effective professional mentoring and minimal ongoing support programs have been suggested as two primary contributors to the chronic shortages of special education teachers. Few programs have been designed to address these specific causes. In this article we describe TATERS, a partnership between a university special educator preparation program, a state Department of Education, and district level administrations designed to (a) develop effective mentoring systems, and (b) strengthen training and recruitment of preservice and new special education teachers, especially in rural areas

An inexpensive economical solar heating system for homes

A low-cost solar home heating system to supplement existing warm-air heating systems is described. The report is written in three parts: (1) a brief background on solar heating, (2) experience with a demonstration system, and (3) information for the homeowner who wishes to construct such a system. Instructions are given for a solar heating installation in which the homeowner supplies all labor necessary to install off-the-shelf components estimated to cost $2,000. These components, which include solar collector, heat exchanger, water pump, storage tank, piping, and controls to make the system completely automatic, are available at local lumber yards, hardware stores, and plumbing supply stores, and are relatively simple to install. Manufacturers and prices of each component used and a rough cost analysis based on these prices are included. This report also gives performance data obtained from a demonstration system which was built and tested at the Langley Research Center