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At least 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
NASA NTRS1987

Surges as tracers of magnetic lines

During the maximum activity year 1980, chromospheric mass ejections were observed with the Multichannel Subtractive Double Pass Spectrograph operating at Meudon (MSDP), while the UV and X-ray emissions were observed respectively with the UV Spectrograph (UVSP) and HXIS instruments on the SMM satellite. These ejections are not related directly to flares but are located in active regions near sunspots. As the magnetic field is frozen in the matter, the study of the velocity field leads to the geometry of the magnetic structures and the temporal evolution of the magnetic-field lines. Ejections of matter recur often with a period of 10 to 20 minutes. In C IV, the bright loops coincide with the H-alpha surge but are more extended. Associated with the events are either X-ray emission or type-III bursts.

Schmieder, B.↗
NASA NTRS1991

Deep FIFO Surge Buffer

First-in/first-out (FIFO) temporarily stores short surges of data generated by data-acquisition system at excessively high rate and releases data at lower rate suitable for processing by computer. Size and complexity reduced while capacity enhanced by use of newly developed, sophisticated integrated circuits and by "byte-folding" scheme doubling effective depth and data rate.

Temple, Gerald↗
NASA NTRS1991

Designs for surge immunity in critical electronic facilities

In recent years, Federal Aviation Administration (FAA) embarked on a program replacing older tube type electronic equipment with newer solid state equipment. This replacement program dramatically increased the susceptibility of the FAA's facilities to lightning related damages. The proposal is presented of techniques which may be employed to lessen the susceptibility of new FAA electronic facility designs to failures resulting from lightning related surges and transients as well as direct strikes. The general concept espoused is one of a consistent system approach employing both perimeter and internal protection. It compares the technique presently employed to reduce electronic noise with other techniques which reduce noise while lowering susceptibility to lightning related damage. It is anticipated that these techniques will be employed in the design of an Air Traffic Control Tower in a high isokeraunic area. This facility would be subjected to rigorous monitoring over a multi-year period to provide quantitative data hopefully supporting the advantage of this design.

Roberts, Edward F., Jr.↗
NASA NTRS1992

Flood surge through the Lunae Planum Outflow Complex, Mars

It is shown that the Maja outflow on Mars was released as a catastrophic outburst from Juventae Chasma. The flood surge traveled the first two-thirds of its length as a semiconfined sheetflood in a broad trough formed by the eastward-sloping Lunae Planum surface and the Xanthe Terra highlands to the east. At its northernmost extent, the flow ponded on the northern Lunae Planum surface. As the flow impounded on the upper Maja lake, waters rose to spill over the Xanthe Terra revetment onto the lower Chryse Planitia surface. The initial spillover crossed Xanthe Terra as sheetflood flow that muted topography over which it passed. The sheetflood was rapidly broken by the irregular topography to cut a complex series of anastomosing channels. A few main channels on eventually captured most of the drainage and local ponds formed in breached craters and irregular basins. The Maja Valles canyon eventually captured the remaining flow at the expense of all other channels.

De Hon, R. A.↗
NASA NTRS1994

Comparison between cool and hot plasma behaviors of surges

Ground-based coordinated observations with the Multichannel Subtractive Double Pass spectrograph (MSDP) allowed us to obtain chromospheric intensity and velocity field maps below coronal structures during the launch of the NIXT payload on 1991 July 11 (eclipse day). A large H-alpha ejection in AR 6713 (N38 W40) was detected during the NIXT flight. However, only a low level of X-ray emission was associated with this event. In contrast, bright X-ray emission associated with a subflare was observed in a nearby active region, but with only a weak associated ejection in H-alpha. A discussion of both of these events gives strong constraints on the triggering mechanisms of surges.

Schmieder, B.↗
NASA NTRS2000

Observations on Rotating Cavitation and Cavitation Surge From The Development of the Fastrac Engine Turbopump

The effects of rotating cavitation and cavitation surges on the Fastrac Engine Turbopump are described in a viewgraph presentation format. The bent inducer blade dilemma and observations of unsteady data and oscillation components are discussed. The pump-feed system stability modeling assessment is outlined. Recommendations are made urging further investigation.

Zoladz, Thomas F.↗
NASA NTRS2009

Smart Ultrasound Remote Guidance Experiment (SURGE) Preliminary Findings

To date, diagnostic quality ultrasound images were obtained aboard the International Space Station (ISS) using the ultrasound of the Human Research Facility (HRF) rack in the Laboratory module. Through the Advanced Diagnostic Ultrasound in Microgravity (ADUM) and the Braslet-M Occlusion Cuffs (BRASLET SDTO) studies, non-expert ultrasound operators aboard the ISS have performed cardiac, thoracic, abdominal, vascular, ocular, and musculoskeletal ultrasound assessments using remote guidance from ground-based ultrasound experts. With exploration class missions to the lunar and Martian surfaces on the horizon, crew medical officers will necessarily need to operate with greater autonomy given communication delays (round trip times of up to 5 seconds for the Moon and 90 minutes for Mars) and longer periods of communication blackouts (due to orbital constraints of communication assets). The SURGE project explored the feasibility and training requirements of having non-expert ultrasound operators perform autonomous ultrasound assessments in a simulated exploration mission outpost. The project aimed to identify experience, training, and human factors requirements for crew medical officers to perform autonomous ultrasonography. All of these aims pertained to the following risks from the NASA Bioastronautics Road Map: 1) Risk 18: Major Illness and Trauna; 2) Risk 20) Ambulatory Care; 3) Risk 22: Medical Informatics, Technologies, and Support Systems; and 4) Risk 23: Medical Skill Training and Maintenance.

Hurst, Victor↗
NASA NTRS2009

SURGE: Smart Ultrasound Remote Guidance Experiment

Exploration-class missions lead to longer communication delays with mission control. May not always have communication capability to stream real-time ultrasound images. SURGE explores use of a "just-in-time" learning tool, called OPEL = On-Board Proficiency Enhancer Light as an aid to a hypothetical crew medical officer working autonomously.

Peterson, Sean↗
NASA NTRS2013

A Storm Surge and Inundation Model of the Back River Watershed at NASA Langley Research Center

This report on a Virginia Institute for Marine Science project demonstrates that the sub-grid modeling technology (now as part of Chesapeake Bay Inundation Prediction System, CIPS) can incorporate high-resolution Lidar measurements provided by NASA Langley Research Center into the sub-grid model framework to resolve detailed topographic features for use as a hydrological transport model for run-off simulations within NASA Langley and Langley Air Force Base. The rainfall over land accumulates in the ditches/channels resolved via the model sub-grid was tested to simulate the run-off induced by heavy precipitation. Possessing both the capabilities for storm surge and run-off simulations, the CIPS model was then applied to simulate real storm events starting with Hurricane Isabel in 2003. It will be shown that the model can generate highly accurate on-land inundation maps as demonstrated by excellent comparison of the Langley tidal gauge time series data (CAPABLE.larc.nasa.gov) and spatial patterns of real storm wrack line measurements with the model results simulated during Hurricanes Isabel (2003), Irene (2011), and a 2009 Nor'easter. With confidence built upon the model's performance, sea level rise scenarios from the ICCP (International Climate Change Partnership) were also included in the model scenario runs to simulate future inundation cases.

Loftis, Jon Derek↗
NASA NTRS2011

On the Non-Monotonic Variation of the Opposition Surge Morphology with Albedo Exhibited by Satellites' Surface

We used well know phase functions of satellites and rings around the giant planets of our Solar System to study the morphology of the opposition effect (at phase angles alpha < 20 degrees. To avoid the effect of the variable finite size of the Sun, we use a deconvolution morphological model to retrieve the morphological parameters of the surge (A and HWHM). These parameters are found to have a non-monotonic variation with the single scattering albedo, similar to that observed in asteroids, which is unexplained so far. The non-monotonic variation is discussed in the framework of the coherent backscattering and shadow hiding mechanisms.

solar system↗
NASA NTRS1971

A study of LC-39 cryogenic systems. Part 1: A study of the vacuum insulated transfer lines at Kennedy Space Center. Part 2: Cooldown pressure surges

The vacuum liquid hydrogen and liquid oxygen transfer lines at Kennedy Space Center were studied to evaluate the feasibility of using a condensing gas such as CO2 inside the vacuum spaces to achieve a condensing-vacuum. The study indicates that at ambient temperature, a maximum vacuum hyphen space pressure of 4000 microns is acceptable for the LH2 transfer lines. In addition, the cooldown procedures for the 14-inch cross-country liquid oxygen line was studied using a simplified mathematical model. Preliminary cooldown times are presented for various heat leak rates to the line and for two vent configurations.

Ludtke, P. R.↗
NASA NTRS1977

Continuation of surge life of transient voltage suppressor

Efforts expended in testing, analyzing and the development of a meaningful definition of the mean number of peak pulses before failure (mp2bf) levels of a family of transient voltage suppressor devices were documented. Tests were done to determine the ability of the transient suppressor to effectively and reliably protect against severe short term, millisecond range, and transient voltages of the types resulting from inductive load switching and induced lightning. Existing pulse testing instrumentation was utilized, interfaced to an automatic sequencing test rack accommodating up to 50 devices. Tests were performed in step stress increments of 25% beginning at 25% and extending thru 100% rated I(pp) for each voltage category. The four voltage types test were the 6.8V, 33V, 91V, and 190V. Engineering efforts addressed the problem of improving the reliability of the 190V types.

Clark, O. M.↗