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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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NASA NTRS2017

Standard Operating Procedure (SOP) for Preparation of an Operation & Configuration Control Plan (OCCP) of "Category B" Pressure Vessels/Systems

This Standard Operating Procedure (SOP) describes the requirements and methodology for preparation of an Operation & Configuration Control Plan (OCCP) as required by JPR 1710.13 to assure safe ground pressurization and pressurization during aircraft operations of “Category B” Pressure Vessels/Systems (PV/S) at Johnson Space Center (JSC), Ellington Field (EFD) and associated NASA spaceflight/aircraft operations facilities. An OCCP is a written assessment showing that a “Category B” PV/S is safe for ground pressurization and pressurization during aircraft operations, within the bounds established by the OCCP.

Nathanael J Greene↗
NASA NTRS2020

Projecting exposure to extreme climate impact events across six event categories and three spatial scales

The extent and impact of climate‐related extreme events depend on the underlying meteorological, hydrological, or climatological drivers as well as on human factors such as land use or population density. Here we quantify the pure effect of historical and future climate change on the exposure of land and population to extreme climate impact events using an unprecedentedly large ensemble of harmonized climate impact simulations from the Inter‐Sectoral Impact Model Intercomparison Project phase 2b. Our results indicate that global warming has already more than doubled both the global land area and the global population annually exposed to all six categories of extreme events considered: river floods, tropical cyclones, crop failure, wildfires, droughts, and heatwaves. Global warming of 2°C relative to preindustrial conditions is projected to lead to a more than five‐fold increase in cross‐category aggregate exposure globally. Changes in exposure are unevenly distributed, with tropical and subtropical regions facing larger increases than higher latitudes. The largest increases in overall exposure are projected for the population of South Asia.

climate‐related extreme events↗
NASA NTRS1972

Development of a category 2 approach system model

An analytical model is presented which provides, as its primary output, the probability of a successful Category II approach. Typical applications are included using several example systems (manual and automatic) which are subjected to random gusts and deterministic wind shear. The primary purpose of the approach system model is to establish a structure containing the system elements, command inputs, disturbances, and their interactions in an analytical framework so that the relative effects of changes in the various system elements on precision of control and available margins of safety can be estimated. The model is intended to provide insight for the design and integration of suitable autopilot, display, and navigation elements; and to assess the interaction of such elements with the pilot/copilot.

Johnson, W. A.↗
NASA NTRS1979

Large Area Crop Inventory Experiment (LACIE). Evaluation of three-category classification

The author has identified the following signficant results. Examination of both machine estimates and stratified areal estimates produced by clustering and classification reveal no significant differences between the proportion estimates and ground truth estimates. When testing the variances of the machine estimates, a significant reduction in the variances was found when the number of starting dots was increased from 30 to 45. The variances were again reduced, although not significantly, when the number of starting dots was increased from 45 to 60. From these results, 60 starting dots are recommended for a three-category classifier. When examining the variances of the estimates for the four estimation procedures (using 60 dots), no significant differences were found between procedures. Thus, only the machine clustering may be used to produce an estimate, and the stratified areal estimate computations and maximum likelihood classification can be deleted.

Havens, K. A.↗
NASA NTRS1982

The Snake River Plain, Idaho - Representative of a new category of volcanism

Studies of the volcanic geology of the Snake River Plain, Idaho, and comparison with other basaltic regions suggest a new category of volcanic activity, termed basaltic plains volcanism. Typified by the Snake River Plain, this style of volcanism is intermediate between basaltic flood (or plateau) eruptions and Hawaiian volcanism. Characteristics that are common to both Hawaiian and plains volcanism are: multiple lava flow units which erupt primarily from point sources, formation of low shields, and frequent emplacement through lava tubes or channels. Characteristics that are common to both flood basalts and plains volcanism are: high volume flows, vents aligned along rift zones, and planar surfaces. The recognition of plains volcanism in other areas provides a means to interpret the style of eruption and volcanic history.

Greeley, R.↗
NASA NTRS1986

Training and subjective workload in a category search task

This study examined automaticity as a means by which training influences mental workload. Two groups were trained in a category search task. One group received a training paradigm designed to promote the development of automaticity; the other group received a training paradigm designed to prohibit it. Resultant performance data showed the expected improvement as a result of the development of automaticity. Subjective workload assessments mirrored the performance results in most respects. The results supported the position that subjective mental workload assessments may be sensitive to the effect of training when it produces a lower level of cognitive load.

Vidulich, Michael A.↗
NASA NTRS1989

A comparison of communication modes for delivery of air traffic control clearance amendments in transport category aircraft

A user centered evaluation is performed on the use of flight deck automation for display and control of aircraft horizontal flight path. A survey was distributed to pilots with a wide range of experience with the use of flight management computers in transport category aircraft to determine the acceptability and use patterns as reflected by the need for information displayed on the electronic horizontal situation indicator. A summary of survey results and planned part-task simulation to compare three communication modes (verbal, alphanumeric, graphic) are presented.

Chandra, D.↗
NASA NTRS1990

The structure and formation of natural categories

Categorization and concept formation are critical activities of intelligence. These processes and the conceptual structures that support them raise important issues at the interface of cognitive psychology and artificial intelligence. The work presumes that advances in these and other areas are best facilitated by research methodologies that reward interdisciplinary interaction. In particular, a computational model is described of concept formation and categorization that exploits a rational analysis of basic level effects by Gluck and Corter. Their work provides a clean prescription of human category preferences that is adapted to the task of concept learning. Also, their analysis was extended to account for typicality and fan effects, and speculate on how the concept formation strategies might be extended to other facets of intelligence, such as problem solving.

Fisher, Douglas↗
NASA NTRS1993

Functional categories for future flight deck designs

With the addition of each new system on the flight deck, the danger of increasing overall operator workload while reducing crew understanding of critical mission information exists. The introduction of more powerful onboard computers, larger databases, and the increased use of electronic display media may lead to a situation of flight deck 'sophistication' at the expense of losses in flight crew capabilities and situational awareness. To counter this potentially negative impact of new technology, research activities are underway to reassess the flight deck design process. The fundamental premise of these activities is that a human-centered, systems-oriented approach to the development of advanced civil aircraft flight decks will be required for future designs to remain ergonomically sound and economically competitive. One of the initial steps in an integrated flight deck process is to define the primary flight deck functions needed to support the mission goals of the vehicle. This would allow the design team to evaluate candidate concepts in relation to their effectiveness in meeting the functional requirements. In addition, this would provide a framework to aid in categorizing and bookkeeping all of the activities that are required to be performed on the flight deck, not just activities of the crew or of a specific system. This could then allow for a better understanding and allocation of activities in the design, an understanding of the impact of a specific system on overall system performance, and an awareness of the total crew performance requirements for the design. One candidate set of functional categories that could be used to guide an advanced flight deck design are described.

Abbott, Terence S.↗
NASA NTRS1995

Flight test evaluation of the Stanford University/United Airlines differential GPS Category 3 automatic landing system

Test flights were conducted to evaluate the capability of Differential Global Positioning System (DGPS) to provide the accuracy and integrity required for International Civil Aviation Organization (ICAO) Category (CAT) 3 precision approach and landings. These test flights were part of a Federal Aviation Administration (FAA) program to evaluate the technical feasibility of using DGPS based technology for CAT 3 precision approach and landing applications. A United Airlines Boeing 737-300 (N304UA) was equipped with DGPS receiving equipment and additional computing capability provided by Stanford University. The test flights were conducted at NASA Ames Research Center's Crows Landing Flight Facility, Crows Landing, California. The flight test evaluation was based on completing 100 approaches and autolandings; 90 touch and go, and 10 terminating with a full stop. Two types of accuracy requirements were evaluated: 1) Total system error, based on the Required Navigation Performance (RNP), and 2) Navigation sensor error, based on ICAO requirements for the Microwave Landing System (MLS). All of the approaches and autolandings were evaluated against ground truth reference data provided by a laser tracker. Analysis of these approaches and autolandings shows that the Stanford University/United Airlines system met the requirements for a successful approach and autolanding 98 out of 100 approaches and autolandings, based on the total system error requirements as specified in the FAA CAT 3 Level 2 Flight Test Plan.

Kaufmann, David N.↗
NASA NTRS1995

Flight test evaluation of the E-systems Differential GPS category 3 automatic landing system

Test flights were conducted to evaluate the capability of Differential Global Positioning System (DGPS) to provide the accuracy and integrity required for International Civil Aviation Organization (ICAO) Category (CAT) III precision approach and landings. These test flights were part of a Federal Aviation Administration (FAA) program to evaluate the technical feasibility of using DGPS based technology for CAT III precision approach and landing applications. An IAI Westwind 1124 aircraft (N24RH) was equipped with DGPS receiving equipment and additional computing capability provided by E-Systems. The test flights were conducted at NASA Ames Research Center's Crows Landing Flight Facility, Crows Landing, California. The flight test evaluation was based on completing 100 approaches and landings. The navigation sensor error accuracy requirements were based on ICAO requirements for the Microwave Landing System (MLS). All of the approaches and landings were evaluated against ground truth reference data provided by a laser tracker. Analysis of these approaches and landings shows that the E-Systems DGPS system met the navigation sensor error requirements for a successful approach and landing 98 out of 100 approaches and landings, based on the requirements specified in the FAA CAT III Level 2 Flight Test Plan. In addition, the E-Systems DGPS system met the integrity requirements for a successful approach and landing or stationary trial for all 100 approaches and landings and all ten stationary trials, based on the requirements specified in the FAA CAT III Level 2 Flight Test Plan.

Kaufmann, David N.↗
NASA NTRS2001

Bandwidth Criteria for Category I and II PIOs

This presentation gives information on: pitch criteria based on airplane Bandwidth; apply research, experimental, operational data; compare Smith-Geddes, Gibson, Neal-Smith criteria; bandwidth criteria for Category II PIO; control/response sensitivity and PIO; extension to roll a axis; and some recommendations.

Mitchell, David G.↗
NASA NTRS2001

Closed-Shell Polycyclic Aromatic Hydrocarbon Cations: A New Category of Interstellar Polycyclic Aromatic Hydrocarbons

Density functional theory has been employed to calculate the harmonic frequencies and intensities of a range of polycyclic aromatic hydrocarbon (PAH) cations that explore both size and electronic structure effects of the infrared spectroscopic properties of these species. The sample extends the size range of PAH species considered to more than 50 carbon atoms and includes several representatives from each of two heretofore unexplored categories of PAH cations: (1) fully benzenoid PAH cations whose carbon skeleton is composed of an odd number of carbon atoms (C(sub odd) PAHs); and (2) protonated PAH cations (HPAH+). Unlike the radical electronic structures of the PAH cations that have been the subject of previous theoretical and experimental work, the species in these two classes have a closed-shell electronic configuration. The calculated spectra of circumcoronene, C54H18 in both neutral and (radical) cationic form are also reported and compared with those of the other species. Overall, the C(sub odd) PAHs spectra are dominated by strong CC stretching modes near 1600 cm(exp -1) and display spectra that are remarkably insensitive to molecular size. The HPAH+ species evince a more complex spectrum consistent with the added contributions of aliphatic modes and their generally lower symmetry. Finally, for both classes of closed-shell cations, the intensity of the aromatic CH stretching modes is found to increase with molecular size far out of proportion with the number of CH groups, approaching a value more typical of neutral PAHs for the largest species studied.

Hudgins, Douglas M.↗
NASA NTRS2007

Electric Field and Lightning Observations in the Core of Category 5 Hurricane Emily

Significant electric fields and lightning activity associated with Hurricane Emily were observed from a NASA high-altitude ER-2 aircraft on July 17, 2005 while this storm developed as a compact but intense category 5 hurricane in the Caribbean south of Cuba. The electrical measurements were acquired as part of the NASA sponsored Tropical Cloud Systems and Processes (TCSP) experiment. In addition to the electrical measurements, the aircraft's remote sensing instrument complement also included active radars, passive microwave, visible and infrared radiometers, and a temperature sounder providing details on the dynamical, microphysical, and environmental structure, characteristics and development of this intense storm. Cloud-to-ground lightning location data from Vaisala's long range lightning detection network were also acquired and displayed in real-time along with electric fields measured at the aircraft. These data and associated display also supported aircraft guidance and vectoring during the mission. During the observing period, flash rates in excess of 3 to 5 flashes per minute, as well as large electric field and field change values were observed as the storm appeared to undergo periods of intensification, especially in the northwest quadrant in the core eyewall regions. This is in contrast to most hurricanes that tend to be characterized by weak electrification and little or no lightning activity except in the outer rain bands. It should be noted that this storm also had significant lightning associated with its rain bands.

Blakeslee, Richard↗