An Experimental Method of Measuring Spectral, Directional Emissivity of Various Materials and Joule Heating

Emissivity is an important parameter in calculating radiative cooling of a surface. In experiments at the NASA Ames hypervelocity ballistic range, one of the main errors indicated in temperature measurements is the uncertainty of emissivity for the materials under investigation. This thesis offers a method for measuring emissivity of materials at elevated temperatures at the University of Kentucky. A test specimen which consists of different sample materials under investigation and a blackbody cavity was heated in a furnace to an isothermal condition at known temperature. The emitted thermal radiation was measured and the comparison of sample and blackbody radiation yielded the desired emissivity. In addition to the furnace measurements, separate experiments were conducted in ambient air to determine how much irradiation is reflected back to the samples from the radiation shield used in the furnace to block undesired ambient radiation. Here, the sample heating was accomplished by applying a direct current across the samples. ANSYS simulations were performed to assist the design and analysis. Experiments were conducted in ambient air and a vacuum environment to verify these simulations

Opening Doors: A Guide to Spontaneous Creation-Making

In this monograph the artists (co-authors) share the background experience that led to developing Spontaneous Creation-making for group processes and community-building. They develop easy to use guidelines to show how to create a safe and sacred space for spontaneous creativity and how to share the outcomes in a non-judgmental sharing circle. Art-making of this kind is not based on problems but on social communal ritual and healthy relations. Resources are offered for further reading

Poor Rural Neighborhoods and Early School Achievement

School consolidation and the search for economies of scale are threatening to render the neighborhood school obsolete. Nevertheless, students and their families do live in neighborhoods. Consequently, education researchers have asked if there are neighborhood-based advantages and disadvantages which influence student achievement. Research has yielded conflicting results. This may be due to failure to properly define and measure neighborhood, acknowledging variation in its nature from place to place. We use ethnographic material to help operationalize the concept neighborhood for use in quantitative research on two very poor, rural counties in West Virginia. We then do a contextual analysis to gauge neighborhood effects among kindergarten children in twelve randomly selected elementary schools. Poor, rural West Virginia neighborhoods turn out not to be the uniformly socially disorganized, culturally pernicious contexts which gave rise to the dubious concept culture of poverty. Instead, they can be sources of safety and stability, where extended families endure, like-minded neighbors are socially accessible and supportive, and early school achievement is enhanced

Top-Down, Routinized Reform in Low-Income, Rural Schools

Since 1991, the National Science Foundation has funded fifty-nine state, urban, and rural systemic initiatives. The purpose of the initiatives is to promote achievement in math, science, and technology among all students, and to encourage schools and communities to secure the resources needed to maintain such outcomes. The Appalachian Rural Systemic Initiative (ARSI) is a six-state consortium which focuses these efforts on low-income, rural schools. The primary means of accomplishing ARSI's aims is a one-day-one-school site visit, called a Program Improvement Review, done by an ARSI math or science expert. The centrally important Program Improvement Reviews, however, seem to be premised on unsubstantiated assumptions as to the static, easy-to-understand, easy-to-evaluate nature of educational achievement in rural Appalachian schools. As a result, the Reviews resemble exercises in early-twentieth century scientific management, and are unlikely to enhance achievement in science or math. Consequently, even if there is merit to the commonsense human capital approach to economic growth and development on which systemic initiatives are tacitly premised, this first- person account makes a case that desired payoffs are unlikely to follow from the work of ARSI

Top-Down, Routinized Reform in Low-Income, Rural Schools: NSF\u27s Appalachian Rural Systemic Initiative

Since 1991, the National Science Foundation has funded fifty-nine state, urban, and rural systemic initiatives. The purpose of the initiatives is to promote achievement in math, science, and technology among all students, and to encourage schools and communities to secure the resources needed to maintain such outcomes. The Appalachian Rural Systemic Initiative (ARSI) is a six-state consortium which focuses these efforts on low-income, rural schools. The primary means of accomplishing ARSI\u27s aims is a one-day-one-school site visit, called a Program Improvement Review, done by an ARSI math or science expert. The centrally important Program Improvement Reviews, however, seem to be premised on unsubstantiated assumptions as to the static, easy-to-understand, easy-to-evaluate nature of educational achievement in rural Appalachian schools. As a result, the Reviews resemble exercises in early-twentieth century scientific management, and are unlikely to enhance achievement in science or math. Consequently, even if there is merit to the commonsense human capital approach to economic growth and development on which systemic initiatives are tacitly premised, this first- person account makes a case that desired payoffs are unlikely to follow from the work of ARSI

Opportunity, Community, and Teen Pregnancy in an Appalachian State

Teen pregnancy has become an issue that educators and public policy makers are obliged to treat as a serious problem. Too often, explanations of teen pregnancy have included uncritical use of the notion of adolescents at risk. Recently, however, attention has been given to structurally-determined contextual factors in explaining teen pregnancy. Such contextual factors include economic and educational opportunities and costs, as well as chances for valued participation in socially and culturally stable communities. This interest in contextual factors parallels a development in the literature on high school dropouts. A data set previously employed to study variability in drop-out rates among school districts in the Appalachian state of West Virginia was used. Results show that teen pregnancy can be explained in much the same way as dropping out. Explanation in terms of contextual factors helps to avoid the victim-blaming accounts sometimes associated with the notion of teenagers at risk. It also suggests that conventional pregnancy prevention programs may be constrained by these same contextual factors in ways that are not typically appreciated

High School Size, Achievement Equity, and Cost

The past decade has occasioned a dramatic increase in research on relationships between school size and a variety of outcomes, including measured achievement, high school completion rates, and postsecondary enrollment rates. An interesting interaction effect which has been found in replications across seven very different states is that as school size increases, the "achievement test score costs" associated with the proportion of economically disadvantaged students enrolled in a school also increase. In short, as schools get larger, average achievement among schools enrolling larger proportions of low socioeconomic-status students suffers. A traditional argument against smaller schools, however, is that they are simpl

Information transfer by vector spin chirality in finite magnetic chains

Vector spin chirality is one of the fundamental characteristics of complex magnets. For a one-dimensional spin-spiral state it can be interpreted as the handedness, or rotational sense of the spiral. Here, using spin-polarized scanning tunneling microscopy, we demonstrate the occurrence of an atomic-scale spin-spiral in finite individual bi-atomic Fe chains on the (5x1)-Ir(001) surface. We show that the broken inversion symmetry at the surface promotes one direction of the vector spin chirality, leading to a unique rotational sense of the spiral in all chains. Correspondingly, changes in the spin direction of one chain end can be probed tens of nanometers away, suggesting a new way of transmitting information about the state of magnetic objects on the nanoscale.Comment: accepted by Physical Review Letter

Stationarity and Geometric Ergodicity of BEKK Multivariate GARCH Models

Conditions for the existence of strictly stationary multivariate GARCH processes in the so-called BEKK parametrisation, which is the most general form of multivariate GARCH processes typically used in applications, and for their geometric ergodicity are obtained. The conditions are that the driving noise is absolutely continuous with respect to the Lebesgue measure and zero is in the interior of its support and that a certain matrix built from the GARCH coefficients has spectral radius smaller than one. To establish the results semi-polynomial Markov chains are defined and analysed using algebraic geometry.Comment: version to appear in Stochastic Processes and their Applications, 2011; http://www.sciencedirect.com/science/article/pii/S030441491100137