1,248 research outputs found
Honeywell Enhancing Airplane State Awareness (EASA) Project: Final Report on Refinement and Evaluation of Candidate Solutions for Airplane System State Awareness
The loss of pilot airplane state awareness (ASA) has been implicated as a factor in several aviation accidents identified by the Commercial Aviation Safety Team (CAST). These accidents were investigated to identify precursors to the loss of ASA and develop technologies to address the loss of ASA. Based on a gap analysis, two technologies were prototyped and assessed with a formative pilot-in-the-loop evaluation in NASA Langleys full-motion Research Flight Deck. The technologies address: 1) data source anomaly detection in real-time, and 2) intelligent monitoring aids to provide nominal and predictive awareness of situations to be monitored and a mission timeline to visualize events of interest. The evaluation results indicated favorable impressions of both technologies for mitigating the loss of ASA in terms of operational utility, workload, acceptability, complexity, and usability. The team concludes that there is a feasible retrofit solution for improving ASA that would minimize certification risk, integration costs, and training impact
Creep and creep rupture of laminated graphite/epoxy composites
An incremental numerical procedure based on lamination theory is developed to predict creep and creep rupture of general laminates. Existing unidirectional creep compliance and delayed failure data is used to develop analytical models for lamina response. The compliance model is based on a procedure proposed by Findley which incorporates the power law for creep into a nonlinear constitutive relationship. The matrix octahedral shear stress is assumed to control the stress interaction effect. A modified superposition principle is used to account for the varying stress level effect on the creep strain. The lamina failure model is based on a modification of the Tsai-Hill theory which includes the time dependent creep rupture strength. A linear cumulative damage law is used to monitor the remaining lifetime in each ply
The Self-Reported Impact of Instructional Coaching on Middle School Teachers\u27 Practices in an Urban Georgia School District
Instructional coaching is viewed as a promising initiative in professional learning for teachers, but there is lack of evidence that links coaching to impacting teachers’ practices (Marsh, McCombs, & Martorell, 2010). This dissertation research investigated relationships between the reported amount and types of instructional coaching received by a sample of middle school teachers in a large, urban school district in Georgia and any reported changes in teacher practice. The population for this study included English Language Arts (ELA) and social studies teachers from Title I schools across the district. This ex post facto study utilized a new survey, based on the Wyoming Instructional Facilitator Survey, was developed at the University of Wyoming (Rush & Young, 2011), to collect data on the extent and focus of reported coaching activities during the 2013-14 school year. The teachers also self-reported on changes in their practices and to what degree those changes were impacted by coaching. Quantitative data analysis of survey research results using the Statistical Package for the Social Sciences (SPSS) took place to investigate the relationships between the amount and type of reported coaching activities and the reported teachers’ changes in practice, as measured by the overall teacher growth and the estimated teacher growth due to coaching. Means and standard deviations were also reported for reported teacher growth and estimated teacher growth due to coaching. Pearson correlation revealed that there were mixed results about coaching. There was no significant relationship between the reported amount and/or type of coaching activities received and the reported overall teacher growth score. There was a significant and positive relationship between the reported amount and type of coaching activities received and the estimated teacher growth due to coaching score. This study examined instructional coaching in a specific context of secondary literacy coaching across content areas. This study added to existing research regarding the focus and the extent of instructional coaching and its impact on teachers
Method of fabricating a photovoltaic module of a substantially transparent construction
A method characterized by the steps of positioning a plurality of uniformly dimensioned photovoltaic cells in registered relation with a plurality of openings formed in a planar tool is disclosed. The method allows acess to the P contact surface of each of the cells. The steps of the method are: (1) connecting the N contact surface of alternate cells to the P contact surface of the cells interposed therebetween, (2) removing therefrom residue of solder flux, (3) applying to the N contact surfaces of the cells a transparent adhesive, (4) placing a common transparent cover plate in engaged relation with the adhesive, (5) placing a film over the circular openings for hermetically sealing the openings, and (6) establishing a vacuum between the film and the cover plate
Confinement induced instability of thin elastic film
A confined incompressible elastic film does not deform uniformly when
subjected to adhesive interfacial stresses but with undulations which have a
characteristic wavelength scaling linearly with the thickness of the film. In
the classical peel geometry, undulations appear along the contact line below a
critical film thickness or below a critical curvature of the plate.
Perturbation analysis of the stress equilibrium equations shows that for a
critically confined film the total excess energy indeed attains a minima for a
finite amplitude of the perturbations which grow with further increase in the
confinement.Comment: 11 pages, 6 figure
Gaia Theory and the Anthropocene: : Radical Contingency in the Posthuman Future
Good readings of the Gaia hypothesis of James Lovelock understand the theory as positing multiple, interlocking Earth systems, characterized by rapidly-changing feedback loops, in a way that is harmonious both with Darwinian evolution and contemporary climate science. The dawning of the geologic epoch of the Anthropocene offers little comfort for those who would like to preserve a providential role for human beings in the unfolding of planetary systems. The climate crisis and its attendant catastrophes demonstrate that human beings cannot control themselves, much less the Earth systems on which they depend. The Gaia hypothesis, properly understood, provides an insight into the shock of radical contingency, the realization that the Earth and life can go along perfectly well without human beings. The Gaia hypothesis provides a good framework for seeing the place of humanity at the dawn of the Anthropocene, a decentering of the human even as humanity alters every Earth system and biome
Electron Spectroscopy for Chemical Analysis (ESCA) study of atmospheric particles
The results of analyses by ESCA (Electron Spectroscopy for Chemical Analysis) on several Nuclepore filters which were exposed during air pollution studies are presented along with correlative measurements by Neutron Activation Analysis and Scanning Electron Microscopy. Samples were exposed during air pollution studies at Norfolk, Virginia and the NASA Kennedy Space Center (KSC). It was demonstrated that with the ESCA technique it was possible to identify the chemical (bonding) state of elements contained in the atmospheric particulate matter collected on Nuclepore filters. Sulfur, nitrogen, mercury, chlorine, alkali, and alkaline earth metal species were identified in the Norfolk samples. ESCA binding energy data for aluminum indicated that three chemically different types of aluminum are present in the launch and background samples from NASA-KSC
Numerical solution methods for viscoelastic orthotropic materials
Numerical solution methods for viscoelastic orthotropic materials, specifically fiber reinforced composite materials, are examined. The methods include classical lamination theory using time increments, direction solution of the Volterra Integral, Zienkiewicz's linear Prony series method, and a new method called Nonlinear Differential Equation Method (NDEM) which uses a nonlinear Prony series. The criteria used for comparison of the various methods include the stability of the solution technique, time step size stability, computer solution time length, and computer memory storage. The Volterra Integral allowed the implementation of higher order solution techniques but had difficulties solving singular and weakly singular compliance function. The Zienkiewicz solution technique, which requires the viscoelastic response to be modeled by a Prony series, works well for linear viscoelastic isotropic materials and small time steps. The new method, NDEM, uses a modified Prony series which allows nonlinear stress effects to be included and can be used with orthotropic nonlinear viscoelastic materials. The NDEM technique is shown to be accurate and stable for both linear and nonlinear conditions with minimal computer time
- …