Analysis of payload bay magnetic fields due to dc power multipoint and single point ground configurations

An analysis of magnetic fields in the Orbiter Payload Bay resulting from the present grounding configuration (structure return) was presented and the amount of improvement that would result from installing wire returns for the three dc power buses was determined. Ac and dc magnetic fields at five points in a cross-section of the bay are calculated for both grounding configurations. Y and Z components of the field at each point are derived in terms of a constant coefficient and the current amplitude of each bus. The dc loads assumed are 100 Amperes for each bus. The ac noise current used is a spectrum 6 db higher than the Orbiter equipment limit for narrowband conducted emissions. It was concluded that installing return wiring to provide a single point ground for the dc Buses in the Payload Bay would reduce the ac and dc magnetic field intensity by approximately 30 db

Sail GTS ground system analysis: Avionics system engineering

A comparison of two different concepts for the guidance, navigation and control test set signal ground system is presented. The first is a concept utilizing a ground plate to which crew station, avionics racks, electrical power distribution system, master electrical common connection assembly and marshall mated elements system grounds are connected by 4/0 welding cable. An alternate approach has an aluminum sheet interconnecting the signal ground reference points between the crew station and avionics racks. The comparison analysis quantifies the differences between the two concepts in terms of dc resistance, ac resistance and inductive reactance. These parameters are figures of merit for ground system conductors in that the system with the lowest impedance is the most effective in minimizing noise voltage. Although the welding cable system is probably adequate, the aluminum sheet system provides a higher probability of a successful system design

Development and initial validation of the determinants of physical activity questionnaire

Background: Physical activity interventions are more likely to be effective if they target causal determinants of behaviour change. Targeting requires accurate identification of specific theoretical determinants of physical activity. Two studies were undertaken to develop and validate the Determinants of Physical Activity Questionnaire. Methods In Study 1, 832 male and female university staff and students were recruited from 49 universities across the UK and completed the 66-item measure, which is based on the Theoretical Domains Framework. Confirmatory factor analysis was undertaken on a calibration sample to generate the model, which resulted in a loss of 31 items. A validation sample was used to cross-validate the model. 20 new items were added and Study 2 tested the revised model in a sample of 466 male and female university students together with a physical activity measure. Results: The final model consisted of 11 factors and 34 items, and CFA produced a reasonable fit χ2 (472) = 852.3, p < .001, CFI = .933, SRMR = .105, RMSEA = .042 (CI = .037-.046), as well as generally acceptable levels of discriminant validity, internal consistency, and test-retest reliability. Eight subscales significantly differentiated between high and low exercisers, indicating that those who exercise less report more barriers for physical activity. Conclusions: A theoretically underpinned measure of determinants of physical activity has been developed with reasonable reliability and validity. Further work is required to test the measure amongst a more representative sample. This study provides an innovative approach to identifying potential barriers to physical activity. This approach illustrates a method for moving from diagnosing implementation difficulties to designing and evaluating interventions

Orbiter CCTV video signal noise analysis

The amount of steady state and transient noise which will couple to orbiter CCTV video signal wiring is predicted. The primary emphasis is on the interim system, however, some predictions are made concerning the operational system wiring in the cabin area. Noise sources considered are RF fields from on board transmitters, precipitation static, induced lightning currents, and induced noise from adjacent wiring. The most significant source is noise coupled to video circuits from associated circuits in common connectors. Video signal crosstalk is the primary cause of steady state interference, and mechanically switched control functions cause the largest induced transients

System Guidelines for EMC Safety-Critical Circuits: Design, Selection, and Margin Demonstration

Demonstration of required safety margins on critical electrical/electronic circuits in large complex systems has become an implementation and cost problem. These margins are the difference between the activation level of the circuit and the electrical noise on the circuit in the actual operating environment. This document discusses the origin of the requirement and gives a detailed process flow for the identification of the system electromagnetic compatibility (EMC) critical circuit list. The process flow discusses the roles of engineering disciplines such as systems engineering, safety, and EMC. Design and analysis guidelines are provided to assist the designer in assuring the system design has a high probability of meeting the margin requirements. Examples of approaches used on actual programs (Skylab and Space Shuttle Solid Rocket Booster) are provided to show how variations of the approach can be used successfully

Designing effective behavioral family interventions for stepfamilies

There is growing evidence that children living in stepfamilies are at greater risk of developing behavior problems, particularly aggressive, antisocial behavior problems, than children living in intact two-parent families. These children are also at high risk of serious long-term consequences including school drop-out and substance abuse. Despite the existence of an effective technology for treating behaviorally disturbed children within traditional family contexts, no research has examined the efficacy of intervention programs designed for children with behavior problems living in stepfamilies. This article reviews the stepfamily research literature to identify factors contributing to child behavior problems in the remarried family context. An integrated model of the development and maintenance of child behavior problems in stepfamilies is developed. Key areas relevant to the treatment of problems in the stepfamily context are discussed. A behavioral family intervention addressing the skills deficits identified in the model is outlined. The implications for the design of stepfamily interventions and issues relevant to conducting effective therapy are highlighted. There is a clear need for future research in this area. In particular, it is recommended that controlled trials be conducted of interventions that specifically address factors known to contribute to child behavior problems in stepfamilies, and which use state of the art behavioral family intervention techniques

Healthcare Innovation Across Sectors: Convergences and Divergences

All of the sectors analyzed in this volume face the same dual challenge: the invention of new technology and assuring its long-term clinical adoption by customers. These challenges are neither easy nor inexpensive. For many of the sectors, the technology and the underlying science have encountered the same phenomenon as other technology development in other endeavors, namely convergence of many skills. Pharmaceutical and biotechnology firms – long accustomed to both random discovery and synthesis of bioactive chemicals or recombination of known active proteins – are now relying on genomic and proteomic foundations for drug discovery. These new sciences are just the first steps in the long process of drug development wherein tools such as bioinformatics must be integrated. As companies in the sector pursue new avenues of discovery and development, and as the associated costs spiral ever upward, healthcare systems throughout the world seek to rationalize care and lower overall costs. The industry has the added burden, therefore, of demonstrating the economic advantages of new drugs, thus giving rise to yet another new discipline, pharmaco-economics

Simple training tricks for mastering and taming bypass procedures in neurosurgery

Background: Neurosurgeons devoted to bypass neurosurgery or revascularization neurosurgery are becoming scarcer. From a practical point of view, 'bypass neurosurgeons' are anastomosis makers, vessels technicians, and time-racing repairers of vessel walls. This requires understanding the key features and hidden tricks of bypass surgery. The goal of this paper is to provide simple and inexpensive tricks for taming the art of bypass neurosurgery. Most of these tricks and materials described can be borrowed, donated, or purchased inexpensively. Methods: We performed a review of relevant training materials and recorded videos for training bypass procedures for 3 years between June 2014 and July 2017. In total, 1,300 training bypass procedures were performed, of which 200 procedures were chosen for this paper. Results : A training laboratory bypass procedures is required to enable a neurosurgeon to develop the necessary skills. The important skills for training bypass procedures gained through meticulous practice to be as reflexes are coordination, speed, agility, flexibility, and reaction time. Bypassing requires synchronization between the surgeon's gross movements, fine motoric skills, and mental strength. The suturing rhythm must be timed in a brain-body-hand fashion. Conclusion: Bypass-Training is a critical part of neurosurgical training and not for a selected few. Diligent and meticulous training can enable every neurosurgeon to tame the art of bypass neurosurgery. This requires understanding the key features and hidden tricks of bypass surgery, as well as uncountable hours of training. In bypass neurosurgery, quality and time goes hand in hand. © 2017 Surgical Neurology International | Published by Wolters Kluwer - Medknow.Peer reviewe

Environmental support for outdoor activities and older people’s Quality of Life

Information unavailable on Web of Knowledge and PubMed

Role of affective attitudes and anticipated affective reactions in predicting health behaviors

Objective: Two measures of affect-affective attitude (AA) and anticipated affective reaction (AAR)- have frequently been used individually, but rarely simultaneously, in correlational studies predicting health behaviors. This research assessed their individual and combined impact in predicting intention and action for a range of health behaviors, controlling for theory of planned behavior (TPB) variables. Method: Self-reported intentions and performance of health behaviors were the main outcome measures. Design: Study 1 is a meta-analysis of published studies (k = 16) measuring the relevant variables. In Study 2, adults (N = 426) completed questionnaires assessing TPB variables, past behavior, AA, AAR, and subsequent behavior for a range of health behaviors. Results: Across both studies, AA and AAR were only moderately intercorrelated, although both had significant correlations with both intentions and behavior. AA was a significant predictor of intentions and behavior after controlling for TPB variables (Studies 1 and 2) plus past behavior (Study 2). In Study 1, AAR was a significant predictor of behavior, but not intentions, when controlling for TPB variables. In Study 2, AAR was a significant predictor of intentions when controlling for both TPB variables plus past behavior (Study 2), but was not a significant predictor of behavior when controlling for either of these variables. Several relationships were moderated by health-behavior category. Conclusions: Both AA and AAR are important predictors of health behaviors and can have independent effects on intentions and action. Studies manipulating both variables to test their independent and combined effects on behavior change are required