Feasibility of standard evaluation procedures for ablating materials

Teflon and high density phenolic-nylon models evaluated at various enthalpies and heating rates under supersonic condition

Subglacial floods beneath ice sheets.

Subglacial floods (jökulhlaups) are well documented as occurring beneath present day glaciers and ice caps. In addition, it is known that massive floods have occurred from ice-dammed lakes proximal to the Laurentide ice sheet during the last ice age, and it has been suggested that at least one such flood below the waning ice sheet was responsible for a dramatic cooling event some 8000 years ago. We propose that drainage of lakes from beneath ice sheets will generally occur in a time-periodic fashion, and that such floods can be of severe magnitude. Such hydraulic eruptions are likely to have caused severe climatic disturbances in the past, and may well do so in the future

Use of thermal infrared and colour infrared imagery to detect crop moisture stress

The author has identified the following significant results. In the presence of variable plant cover (primarily percent cover) and variable available water content, the remotely sensed apparent temperatures correlate closely with plant cover and poorly with soil water. To the extent that plant cover is not systematically related to available soil water, available water in the root zone values may not be reliably predicted from the thermal infrared data. On the other hand, if plant cover is uniform and the soil surface is shown in a minor way, the thermal data indicate plant stress and consequently available water in the soil profile

Meeting the Needs of Young Adolescents

During the past 40 years, research from more than 80 studies has shown that students in interdisciplinary programs do as well as, if not better than students in single­ subject curricular structures on standardized tests (Vars, 1991). In addition, the opportunities for teachers to work together to develop learning experiences for their students create school climates that focus efforts on student needs, curriculum and instructional improvement, and reflection (Clark and Clark, 1994a)

Relationships between stratospheric clear air turbulence and synoptic meteorological parameters over the western United States between 12-20 km altitude

Procedures for forecasting clear air turbulence in the stratosphere over the western United States from rawinsonde data are described and results presented. Approaches taken to relate meteorological parameters to regions of turbulence and nonturbulence encountered by the XB-70 during 46 flights at altitudes between 12-20 km include: empirical probabilities, discriminant function analysis, and mountainwave theory. Results from these techniques were combined into a procedure to forecast regions of clear air turbulence with an accuracy of 70-80 percent. A computer program was developed to provide an objective forecast directly from the rawinsonde sounding data

Beta lives - some statistical perspectives on the capital asset pricing model

This note summarizes some technical issues relevant to the use of the idea of excess return in empirical modelling. We cover the case where the aim is to construct a measure of expected return on an asset and a model of the CAPM type is used. We review some of the problems and show examples where the basic CAPM may be used to develop other results which relate the expected returns on assets both to the expected return on the market and other factors

A critical analysis of the tools to evaluate neuropsychiatric lupus.

Neuropsychiatric symptoms occur commonly in patients with systemic lupus erythematosus, but they are not always due to active disease. It is crucial to identify cases that are due to active systemic lupus erythematosus so that appropriate treatment can be instituted. There is no single serological or imaging test that distinguishes active neuropsychiatric systemic lupus erythematosus from neuropsychiatric manifestations caused by other factors such as infection. Most patients with neuropsychiatric systemic lupus erythematosus have generalised features of disease activity. Raised anti-dsDNA and low C3 complement levels are often seen, but are not an invariable guide. The presence of antiphospholipid antibodies is more suggestive of thrombotic than inflammatory causation. A number of other autoantibody tests have been proposed as biomarkers for neuropsychiatric systemic lupus erythematosus, but results in clinical studies have been inconsistent and none has so far entered routine clinical practice. Cerebrospinal fluid features and magnetic resonance imaging appearances are non-specific in neuropsychiatric systemic lupus erythematosus, but are useful in excluding other causes of neuropsychiatric symptoms. Newer magnetic resonance imaging sequences show promise for distinguishing new neuropsychiatric systemic lupus erythematosus activity from previous damage and recent research suggests these may correlate with changes in cognitive function in patients with systemic lupus erythematosus. However, formal cognitive testing is seldom carried out in the acute setting