194 research outputs found
A study of large, medium and small scale structures in the topside ionosphere
Alouette and ISIS data were studied for large, medium, and small scale structures in the ionosphere. Correlation was also sought with measurements by other satellites, such as the Atmosphere Explorer C and E and the Dynamic Explorer 2 satellites, of both neutrals and ionization, and with measurements by ground facilities, such as the incoherent scatter radars. Large scale coherent wavelike structures were found from ISIS 2 electron density contours from above the F peak to nearly the satellite altitude. Such structures were also found to correlate with the observation by AE-C below the F peak during a conjunction of the two satellites. Vertical wavefronts found in the upper F region suggest the dominance of diffusion along field lines as well. Also discovered were multiple, evenly spaced field-aligned ducts in the F region that, at low latitudes, extended to the other hemisphere and were in the form of field-aligned sheets in the east-west direction. Low latitude heating events were discovered that could serve as sources for waves in the ionosphere
Multi-Point Combustion System: Final Report
A low-NOx emission combustor concept has been developed for NASA's Environmentally Responsible Aircraft (ERA) program to meet N+2 emissions goals for a 70,000 lb thrust engine application. These goals include 75 percent reduction of LTO NOx from CAEP6 standards without increasing CO, UHC, or smoke from that of current state of the art. An additional key factor in this work is to improve lean combustion stability over that of previous work performed on similar technology in the early 2000s. The purpose of this paper is to present the final report for the NASA contract. This work included the design, analysis, and test of a multi-point combustion system. All design work was based on the results of Computational Fluid Dynamics modeling with the end results tested on a medium pressure combustion rig at the UC and a medium pressure combustion rig at GRC. The theories behind the designs, results of analysis, and experimental test data will be discussed in this report. The combustion system consists of five radially staged rows of injectors, where ten small scale injectors are used in place of a single traditional nozzle. Major accomplishments of the current work include the design of a Multipoint Lean Direct Injection (MLDI) array and associated air blast and pilot fuel injectors, which is expected to meet or exceed the goal of a 75 percent reduction in LTO NOx from CAEP6 standards. This design incorporates a reduced number of injectors over previous multipoint designs, simplified and lightweight components, and a very compact combustor section. Additional outcomes of the program are validation that the design of these combustion systems can be aided by the use of Computational Fluid Dynamics to predict and reduce emissions. Furthermore, the staging of fuel through the individually controlled radially staged injector rows successfully demonstrated improved low power operability as well as improvements in emissions over previous multipoint designs. Additional comparison between Jet- A fuel and a hydrotreated biofuel is made to determine viability of the technology for use with alternative fuels. Finally, the operability of the array and associated nozzles proved to be very stable without requiring additional active or passive control systems. A number of publications have been publis
The presence of psychological trauma symptoms in resuscitation providers and an exploration of debriefing practices
Introduction
Witnessing traumatic experiences can cause post-traumatic stress disorder (PTSD). The true impact on healthcare staff of attending in-hospital cardiac arrests (IHCAs) has not been studied. This cross-sectional study examined cardiac arrest debriefing practices and the burden of attending IHCAs on nursing and medical staff.
Methods
A 33-item questionnaire-survey was sent to 517 doctors (of all grades), nurses and health-care assistants (HCAs) working in the emergency department, the acute medical unit and the intensive care unit of a district general hospital between April and August 2018. There were three sections: demographics; cardiac arrest and debriefing practices; trauma-screening questionnaire (TSQ).
Results
The response rate was 414/517 (80.1%); 312/414 (75.4%) were involved with IHCAs. Out of 1463 arrests, 258 (17.6%) were debriefed. Twenty-nine of 302 (9.6%) staff screened positively for PTSD. Healthcare assistants and Foundation Year 1 doctors had higher TSQ scores than nurses or more senior doctors (p = 0.02, p = 0.02, respectively). Debriefing was not associated with PTSD risk (p = 0.98). Only 8/67 (11.9%) of resuscitation leaders had prior debriefing training.
Conclusions
Nearly 10% of acute care staff screened positively for PTSD as a result of attending an IHCA, with junior staff being most at risk of developing trauma symptoms. Very few debriefs occurred, possibly because of a lack of debrief training amongst cardiac arrest team leaders. More support is required for acute care nursing and medical staff following an IHCA
PS210. Surgical Restoration of Flow Following Prolonged Ischemia Inhibits Neuromuscular Recovery in a Porcine (Sus Scrofa) Model of Extremity Vascular Injury
Snow Chemistry from Xixabangma Peak, Tibet
[From conclusion] Although the cause of the differences in chemistry of the Xixabangma glacier fresh snow events cannot be adequately inferred from the limited number of samples available for this study, the existence of such different chemical signatures is encouraging for future studies in the region
Accurate Methods for Large Molecular Systems
Three exciting new methods that address the accurate prediction of processes and properties of large molecular systems are discussed. The systematic fragmentation method (SFM) and the fragment molecular orbital (FMO) method both decompose a large molecular system (e.g., protein, liquid, zeolite) into small subunits (fragments) in very different ways that are designed to both retain the high accuracy of the chosen quantum mechanical level of theory while greatly reducing the demands on computational time and resources. Each of these methods is inherently scalable and is therefore eminently capable of taking advantage of massively parallel computer hardware while retaining the accuracy of the corresponding electronic structure method from which it is derived. The effective fragment potential (EFP) method is a sophisticated approach for the prediction of nonbonded and intermolecular interactions. Therefore, the EFP method provides a way to further reduce the computational effort while retaining accuracy by treating the far-field interactions in place of the full electronic structure method. The performance of the methods is demonstrated using applications to several systems, including benzene dimer, small organic species, pieces of the α helix, water, and ionic liquids
Affective Writing as a Promise of “Yet-To-Become:” Unearthing the Meaning of Writing Through the Voices of Tenure-Track Assistant Professors
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