Studies of the role of metastables and doubly ionized species in the chemical and thermal structure of the Venusian and Martian ionospheres

Models of the upper atmospheres of Mars and Venus were constructed using Viking and Pioneer Venus data. The neutral densities, with the exception of NO, N(4S), N(2D) and N(2P) were taken from the measured values, along with the neutral, ion, and electron temperatures. Using solar fluxes and relevant cross sections, the production rates of ions and neutral fragments by photo and electron impact processes were computed. These production rates were combined with chemical production rates and loss along with one dimensional transport eddy diffusion, molecular and ambi polar diffusion, and thermal diffusion, to determine the densities of ions and odd nitrogen species. Preliminary calculations show that the chemistry of metastables and doubly ionized species is important in the ionospheres of Mars and Venus. Production of N(+) in metastable reactions is particularly important, and it explains the discrepancy between the measurements of earlier models. Production of CO(+) is also affected. Reactions of O(++) and O(+)(2D) with N2 have important consequences for the escape rate of atomic nitrogen from the Martian atmosphere

Studies of the chemistry of vibrationally and electronically excited species in planetary upper atmospheres

The vibrational distribution of O2(+) in the atmospheres of Venus and Mars was investigated to compare with analogous values in the Earth's atmosphere. The dipole moment of the Z(2) Pi sub u - X(2) Pi sub g transition of O2(+) is calculated as a function of internuclear distance. The band absorption oscillator strengths and band transition probabilities of the second negative system are derived. The vibrational distribution of O2(+) in the ionosphere of Venus is calculated for a model based on data from the Pioneer Venus neutral mass spectrometer

Studies of the aurorally-induced ultraviolet emissions on the nightside of Venus

The effect of a monoenergetic flux of electrons on a model atmosphere of the nightside thermosphere of Venus was examined. The neutral model chosen is that of Hedin for high solar activity and l65 degrees solar zenith angle. The model is based on measurements made by the Pioneer Venus Orbiter Neutral Mass Spectrometer. Four species were included in the calculation: CO2, O, CO, and N2. The numerical method that was chosen for energy deposition of the primary electrons is the continuous slowing down approximation. The secondary electron distribution was computed using the empirically determined shape of the differential cross section

One-step dual purpose joining technique

This fastener used in induction heating is a wire screen basically of an eddy current carrying material such as carbon steel. Selected wires in the screen are copper, sheathed in an insulating material. The screen is placed between two sheets of thermoplastics. When inductively heated, the composite softens and flows around the apertures of the screen. After this heating and joining, the copper wires may be used to conduct electricity

Variations in Texas school quality

Texas ; Education ; Federal Reserve District, 11th

The health and sport engagement (HASE) intervention and evaluation project: protocol for the design, outcome, process and economic evaluation of a complex community sport intervention to increase levels of physical activity.

INTRODUCTION: Sport is being promoted to raise population levels of physical activity for health. National sport participation policy focuses on complex community provision tailored to diverse local users. Few quality research studies exist that examine the role of community sport interventions in raising physical activity levels and no research to date has examined the costs and cost-effectiveness of such provision. This study is a protocol for the design, outcome, process and economic evaluation of a complex community sport intervention to increase levels of physical activity, the Health and Sport Engagement (HASE) project part of the national Get Healthy Get Active programme led by Sport England. METHODS AND ANALYSIS: The HASE study is a collaborative partnership between local community sport deliverers and sport and public health researchers. It involves designing, delivering and evaluating community sport interventions. The aim is to engage previously inactive people in sustained sporting activity for 1×30 min a week and to examine associated health and well-being outcomes. The study uses mixed methods. Outcomes (physical activity, health, well-being costs to individuals) will be measured by a series of self-report questionnaires and attendance data and evaluated using interrupted time series analysis controlling for a range of sociodemographic factors. Resource use will be identified and measured using diaries, interviews and records and presented alongside effectiveness data as incremental cost-effectiveness ratios and cost-effectiveness acceptability curves. A longitudinal process evaluation (focus groups, structured observations, in-depth interview methods) will examine the efficacy of the project for achieving its aim using the principles of thematic analysis. ETHICS AND DISSEMINATION: The results of this study will be disseminated through peer-reviewed publications, academic conference presentations, Sport England and national public health organisation policy conferences, and practice-based case studies. Ethical approval was obtained through Brunel University London's research ethics committee (reference number RE33-12)

Are geometric morphometric analyses replicable? Evaluating landmark measurement error and its impact on extant and fossil Microtus classification.

Geometric morphometric analyses are frequently employed to quantify biological shape and shape variation. Despite the popularity of this technique, quantification of measurement error in geometric morphometric datasets and its impact on statistical results is seldom assessed in the literature. Here, we evaluate error on 2D landmark coordinate configurations of the lower first molar of five North American Microtus (vole) species. We acquired data from the same specimens several times to quantify error from four data acquisition sources: specimen presentation, imaging devices, interobserver variation, and intraobserver variation. We then evaluated the impact of those errors on linear discriminant analysis-based classifications of the five species using recent specimens of known species affinity and fossil specimens of unknown species affinity. Results indicate that data acquisition error can be substantial, sometimes explaining >30% of the total variation among datasets. Comparisons of datasets digitized by different individuals exhibit the greatest discrepancies in landmark precision, and comparison of datasets photographed from different presentation angles yields the greatest discrepancies in species classification results. All error sources impact statistical classification to some extent. For example, no two landmark dataset replicates exhibit the same predicted group memberships of recent or fossil specimens. Our findings emphasize the need to mitigate error as much as possible during geometric morphometric data collection. Though the impact of measurement error on statistical fidelity is likely analysis-specific, we recommend that all geometric morphometric studies standardize specimen imaging equipment, specimen presentations (if analyses are 2D), and landmark digitizers to reduce error and subsequent analytical misinterpretations