LDEF atomic oxygen fluence update

The definition of LDEF atomic oxygen exposure involves theoretical prediction of fluxes, modeling of shielding and scattering effects, and comparison of predicted with observed atomic oxygen effects on LDEF experiments. Work is proceeding as follows: atomic oxygen fluxes and fluences have been recalculated using a more detailed orbit prediction program; a micro-environments program is being developed to account for the effects of experiment geometry on atomic oxygen flux; and chemical and physical measurements are being made on copper grounding straps to verify correspondence between predicted exposures and observed surface property variations. These three areas of work are reported briefly

Atomic oxygen flux and fluence calculation for Long Duration Exposure Facility (LDEF)

The LDEF mission was to study the effects of the space environment on various materials over an extended period of time. One of the important factors for materials degradation in low earth orbit is the atomic oxygen fluxes and fluences experienced by the materials. These fluxes and fluences are a function of orbital parameters, solar and geomagnetic activity, and material surface orientation. Calculations of atomic oxygen fluences and fluxes for the LDEF mission are summarized. Included are descriptions of LDEF orbital parameters, solar and geomagnetic data, computer code FLUXAV, which was used to perform calculations of fluxes and fluences, along with a discussion of the calculated fluxes and fluences

Analysis of selected specimens from the STS-46 Energetic Oxygen Interaction with Materials-3 experiment

The Energetic Oxygen Interaction with Materials 3 (EOIM-3) experiment was flown on the STS-46 mission, which was launched on 31 Jul. 1992 and returned 8 Aug. 1992. Boeing specimens were located on both the NASA Marshall Space Flight Center (MSFC) tray and the Ballistic Missile Defense Organization (BMDO) tray integrated by the Jet Propulsion Laboratory (JPL). The EOIM-3 pallet was mounted in the Space Shuttle payload bay near the aft bulkhead. During the mission, the atomic oxygen (AO) exposure levels of specimens in these passive sample trays was about 2.3 x 10(exp 20) atoms/sq cm. The specimens also received an estimated 22 equivalent sun hours of solar exposure. In addition, it appears that the EOIM-3 pallet was exposed to a silicone contamination source and many specimens had a thin layer of silicon based deposit on their surfaces after the flight. The specimens on the MSFC tray included seven solid film lubricants, a selection of butyl rubber (B612) and silicone (S383) o-rings, three indirect scatter surfaces, and Silver/Fluorinated Ethylene Propylene (Ag/FEP) and Chemglaze A276 specimens which had previously flown on trailing edge locations of the Long Duration Exposure Facility (LDEF). The specimens on the JPL tray included composites previously flown on LDEF and two indirect scattering surfaces

The winds and currents mission concept

© The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Rodriguez, E., Bourassa, M., Chelton, D., Farrar, J. T., Long, D., Perkovic-Martin, D., & Samelson, R. The winds and currents mission concept. Frontiers in Marine Science, 6, (2019): 438, doi:10.3389/fmars.2019.00438.The Winds and Currents Mission (WaCM) is a proposed approach to meet the need identified by the NRC Decadal Survey for the simultaneous measurements of ocean vector winds and currents. WaCM features a Ka-band pencil-beam Doppler scatterometer able to map ocean winds and currents globally. We review the principles behind the WaCM measurement and the requirements driving the mission. We then present an overview of the WaCM observatory and tie its capabilities to other OceanObs reviews and measurement approaches.ER was funded under NASA grant NNN13D462T. DC was funded under NASA grant NNX10AO98G. JF was funded under NASA grants NNX14AM71G and NNX16AH76G. DL was funded under NASA grant NNX14AM67G. DP-M was funded under NASA grant NNH13ZDA001N. RS was funded under NASA grant NNX14AM66G

Number preferences in lotteries

We explore people's preferences for numbers in large proprietary data sets from two different lottery games. We find that choice is far from uniform, and exhibits some familiar and some new tendencies and biases. Players favor personally meaningful and situationally available numbers, and are attracted towards numbers in the center of the choice form. Frequent players avoid winning numbers from recent draws, whereas infrequent players chase these. Combinations of numbers are formed with an eye for aesthetics, and players tend to spread their numbers relatively evenly across the possible range

2012 ACCF/AHA/ACP/AATS/PCNA/SCAI/STS guideline for the diagnosis and management of patients with stable ischemic heart disease

The recommendations listed in this document are, whenever possible, evidence based. An extensive evidence review was conducted as the document was compiled through December 2008. Repeated literature searches were performed by the guideline development staff and writing committee members as new issues were considered. New clinical trials published in peer-reviewed journals and articles through December 2011 were also reviewed and incorporated when relevant. Furthermore, because of the extended development time period for this guideline, peer review comments indicated that the sections focused on imaging technologies required additional updating, which occurred during 2011. Therefore, the evidence review for the imaging sections includes published literature through December 2011

El Niño Tropical Pacific Ocean Surface Current and Temperature Evolution in 2002 and Outlook for Early 2003

[1] The timing and magnitude of the 2002–2003 El Niño/Southern Oscillation (ENSO) warm episode has been monitored for the first time with near real time satellite-derived surface current (SC) fields in addition to the operational temperature, wind and sea level satellite and in situ measurements previously used. The record of the past decade shows that dominant SC anomalies generally lead ENSO sea surface temperature (SST) anomalies by 2.5–3 months, and that a rapid SC anomaly reversal has coincided with the peak SST of warm events. During September to December 2002, SST anomalies increased and spread eastward in conjunction with strong, sustained eastward SC anomalies that began in July. The SC anomaly peaked in early October, followed by a sharp decrease in November and December to negative values in January. This was much like the SC sequence during the same months of the 1997–1998 El Niño when the SST anomaly peaked in December 1997. The recent SST anomalies were maximum in November 2002 and declined thereafter. These SC and SST trends signify that the present warm event has peaked and SST anomalies will continue to decline in early 2003

El Niño Tropical Pacific Ocean Surface Current and Temperature Evolution in 2002 and Outlook for Early 2003

[1] The timing and magnitude of the 2002–2003 El Niño/Southern Oscillation (ENSO) warm episode has been monitored for the first time with near real time satellite-derived surface current (SC) fields in addition to the operational temperature, wind and sea level satellite and in situ measurements previously used. The record of the past decade shows that dominant SC anomalies generally lead ENSO sea surface temperature (SST) anomalies by 2.5–3 months, and that a rapid SC anomaly reversal has coincided with the peak SST of warm events. During September to December 2002, SST anomalies increased and spread eastward in conjunction with strong, sustained eastward SC anomalies that began in July. The SC anomaly peaked in early October, followed by a sharp decrease in November and December to negative values in January. This was much like the SC sequence during the same months of the 1997–1998 El Niño when the SST anomaly peaked in December 1997. The recent SST anomalies were maximum in November 2002 and declined thereafter. These SC and SST trends signify that the present warm event has peaked and SST anomalies will continue to decline in early 2003