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At least 1,243 records · Page 69
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Common Faults and Their Prioritization in Small Commercial Buildings: February 2017 - December 2017

To support an ongoing project at NREL titled 'An Open, Cloud-Based Platform for Whole-Building Fault Detection and Diagnostics' (work breakdown structure number 3.2.6.18 funded by the Department of Energy Building Technologies Office), this report documents faults that are commonly found in small commercial buildings (with a floor area of 10,000 ft2 or less) based on a literature review and discussions with building commissioning experts. It also provides a list of prioritized faults based on an estimation of the prevalence, energy impact, and financial impact of each fault.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2016

HST HOT-JUPITER TRANSMISSION SPECTRAL SURVEY: CLEAR SKIES FOR COOL SATURN WASP-39b

We present the Hubble Space Telescope (HST) Space Telescope Imaging Spectrograph (STIS) optical transmission spectroscopy of the cool Saturn-mass exoplanet WASP-39b from 0.29-1.025 μ m, along with complementary transit observations from Spitzer IRAC at 3.6 and 4.5 μ m. The low density and large atmospheric pressure scale height of WASP-39b make it particularly amenable to atmospheric characterization using this technique. We detect a Rayleigh scattering slope as well as sodium and potassium absorption features; this is the first exoplanet in which both alkali features are clearly detected with the extended wings predicted by cloud-free atmosphere models. The full transmission spectrum is well matched by a clear H{sub 2}-dominated atmosphere, or one containing a weak contribution from haze, in good agreement with the preliminary reduction of these data presented in Sing et al. WASP-39b is predicted to have a pressure-temperature profile comparable to that of HD 189733b and WASP-6b, making it one of the coolest transiting gas giants observed in our HST STIS survey. Despite this similarity, WASP-39b appears to be largely cloud-free, while the transmission spectra of HD 189733b and WASP-6b both indicate the presence of high altitude clouds or hazes. These observations further emphasize the surprising diversity of cloudy and cloud-free gas giant planets in short-period orbits and the corresponding challenges associated with developing predictive cloud models for these atmospheres.

79 ASTRONOMY AND ASTROPHYSICS↗
NASA NTRS1970

A search for life on earth at 100 meter resolution

A study of several thousand photos indicated approximately 1% of Gemini and Apollo photographs of the earth at 100 m resolution revealed signs of life; rectangular arrays due to human agricultural and urban territoriality, roads, canals, jet contrails, and industrial pollution. Potential false positives such as dunes, sand bars, and jet stream clouds abound. A curve was derived for the detectivity of contemporary life on earth, in a plot of ground resolution versus global coverage. A comparable biology on Mars would not have been detected by all observations of Mars through Mariner 7. Forthcoming Mars orbiter and lander imaging experiments hold significant promise of detecting life on Mars of contemporary terrestrial extent and advancement, should such life exist.

Sagan, C.↗
NASA NTRS1971

A search for life on earth at 100 meter resolution.

Study of several thousand photos indicating that about 0.01 of Gemini and Apollo photographs of the earth at 100 m resolution reveal signs of life - rectangular arrays due to human agricultural and urban territoriality, roads, canals, jet contrails, and industrial pollution. Potential false positives - e.g., dunes, sand bars, jetstream clouds - abound. A curve is derived for the detectivity of contemporary life on earth, in a plot of ground resolution versus global coverage. A comparable biology on Mars would not have been detected by all observations of Mars through Mariner 7.

Sagan, C.↗
NASA NTRS1973

Mapping Arctic sea ice from the Earth Resources Technology Satellite

The author has identified the following significant results. Methods of detecting ice and for distinguishing between ice and clouds are discussed, and examples of ERTS-1 data showing ice distributions in northern Hudson Bay, M'Clure Strait, the eastern Beaufort Sea, and the Greenland Sea are presented. The results of the initial analysis of ERTS-1 data indicate that the locations of ice edges and ice concentrations can be accurately mapped, and that considerable information on ice type can be derived through use of the various spectral bands. Ice features as small as 80 to 100 m width can be mapped.

Barnes, J. C.↗
NASA NTRS1974

A high-resolution map of the Orion Nebula region at far-infrared wavelengths

It is shown that the Kleinmann-Low nebula continues to radiate like a 70-deg-K blackbody at 69 microns, as it does at shorter wavelengths, but that most of the 69-micron flux from Ori A (M42) comes from an extended emission that roughly follows the free-free radio emission. Nearby sources also detected include the nebula M43 and the molecular cloud OMC-2.

Fazio, G. G.↗
NASA NTRS1978

Methane detected in Orion A

This letter reports the detection of line emission from the Orion Molecular Cloud corresponding to six distinct pure-rotational delta J = 0 transitions in CH4. The transitions observed and the transition frequencies are: J = 11 E(2) - E(1), 4600.359 MHz; J = 18 F1(4) - F2(1), 76,231.45 MHz; J = 18 A1(2) - A2(1), 76,700.02 MHz; J = 19 F1(4) - F2(1), 75,944.99 MHz; J = 19 F2(4) - F1(1), 78,233.59 MHz; and J = 20 F2(5) - F1(2), 82,873.59 MHz. The observed spectra at the six transition frequencies are plotted, and all but two of the methane lines are found to be very narrow (about 2 km/s). It is noted that the small velocity widths of the four weaker lines and an observed variability of the J = 18 A line are classic characteristics of a maser and that the excitation appears to be nonthermal. An effective excitation temperature of 1100 to 2100 K is estimated for the methane in Orion A.

Fox, K.↗
NASA NTRS1980

Optical polarization of the Seyfert galaxies Mrk 3, Mrk 231, NGC 3227 and NGC 3516

The paper presents intermediate resolution observations of the emission line and continuum polarization of the Seyfert galaxies Mrk 3, Mrk 231, NGC 3227, and NGC 3516. The polarization shows a strong wavelength dependence with the polarization increasing smoothly into the blue for each galaxy. This wavelength dependence, together with the presence of polarized H(alpha) emission, indicates that the polarization of each galaxy is caused by an asymmetric dust envelope surrounding the nucleus. Observations of the polarization of the /O III/ lambda 5007 emission in Mrk 3 and NGC 3227, and the polarization through the nonstellar Na ID line absorption in Mrk 231 are used to place constraints on the extent of the polarizing clouds in these galaxies. No polarization variability was detected with time-bases ranging from a few weeks to three years.

Thompson, I.↗
NASA NTRS1982

Precipitation measurements from space - Workshop summary 28 April-1 May 1981, Greenbelt, MD

The goals and methods for global precipitation measurements from space are examined. Records currently exist only for visible and IR scans of cloud properties, and are applied from GEO for detecting diurnal variations in precipitation. Microwave radiometry is noted to be a suitable method for supplementing the visible and IR data for measuring stratiform oceanic precipitation, and when used at up to 3 microns can detect areas, if not amounts, of precipitation from GEO. Applications of radar altimeters are proposed in terms of modifications to the Seasat-type 2.2 cm radar, the use of surface target attentuation radar, of frequency agile rain radar, or of adaptive pointing radar. Soil moisture sensing is available with passive microwave radiometry in the 20-50 cm bands, or active sensing in the 5-8 cm bands. The utilization of GARP ground truth data is explored, along with statistical methods for treating the data samples.

Atlas, D.↗
NASA NTRS1984

A new interstellar molecule - Tricarbon monoxide

The C3O molecule, whose pure rotational spectrum has only recently been studied in the laboratory, has been detected in the cold, dark interstellar Taurus Molecular Cloud 1. Since C3O is the first interstelar carbon chain molecule to contain oxygen, its existence places an important new constraint on chemical schemes for cold interstellar clouds. The abundance of C3O can be understood in terms of purely gas-phase ion-molecule chemistry.

Matthews, H. E.↗
NASA NTRS1990

The absence of circumstellar dust debris around G giants

The IRAS data base has been searched for evidence for circumstellar dust around luminosity class III G giants, stars whose progenitors are mostly main-sequence A stars. While 20 percent of all main-sequence A dwarfs have dust which absorbs at least 5 x 10 to the -6th of the light from the star, less than 3 percent of all G giants have such clouds. One possible explanation for the absence of detectable dust debris around the G giants is that the Poynting-Robertson effect leads to the decay of the dust around the main-sequence A stars, and that the supply of these grains is not renewed indefinitely. In this case, the derived upper limit to the grain radius of about 0.2 cm for the bulk of the grains emitting the far-infrared emission is consistent with data derived from ground-based submillimeter observations. Another possible explanation for the lack of grains around at least some G giants is that the dust around the original A dwarf is mainly composed of relatively volatile material like water ice which thermally evaporates in a relatively short time during the giant phase of higher luminosity.

Jura, M.↗
NASA NTRS1993

Balloon observations of interstellar CII (158 microns) and OI (63 microns) forbidden lines

Interstellar CII and OI forbidden lines were observed by the Balloon-Borne Infrared Telescope (BIRT) with a Fabry-Perot spectrometer. Two balloon flights were successfully made. With a method of 'frequency switching', diffuse CII forbidden-line emission was efficiently detected and mapped in extended regions around HII/molecular cloud complexes and in a wide area of the Galactic plane. It has been shown that the CII forbidden-line emission is very strong and ubiquitously distributed in interstellar space in the Galaxy.

Shibai, H.↗
NASA NTRS1996

The ROSAT All-Sky Survey view of the Large Magellanic Cloud (LMC)

During the Rosat all sky survey, centered on the Large Magellanic Cloud (LMC), 516 X-ray sources were detected. The field was covered from July 1990 to January 1991. The X-ray parameters of the sources, involving position, count rates, hardness ratios, extent, and time variability during the observations, are discussed. Identifications with objects from optical, radio and infrared wavelength allow the LMC candidates to be separated from the foreground stars and the background objects.

Pietsch, W.↗
NASA NTRS1999

Global Frequency and Distribution of Lightning as Observed by the Optical Transient Detector (OTD)

The Optical Transient Detector (OTD) is a space-based instrument specifically designed to detect and locate lightning discharges (intracloud and cloud-to-ground) as it orbits the Earth. A statistical examination of OTD lightning data reveals that nearly 1.2 billion flashes occurred over the entire earth during the one year period from September 1995 through August 1996. This translates to an average of 37 lightning flashes occurring around the globe every second, which is well below the traditional estimate of 100 flashes per second. An average of 75% of the global lightning activity during the year occurs between 30 deg S and 30 deg N. An analysis of the annual lightning distribution reveals that an average of 82% of the lightning flashes occur over the continents and 18% over the oceans, which translates to an average land-ocean flash density ratio of nearly 11.

Christian, Hugh J.↗
NASA NTRS1999

Global Frequency and Distribution of Lightning as Observed by the Optical Transient Detector (OTD)

The Optical Transient Detector (OTD) is a space-based instrument specifically designed to detect and locate lightning discharges (intracloud and cloud-to-ground) as it orbits the Earth. A statistical examination of OTD lightning data reveals that nearly 1.2 billion flashes occurred over the entire earth during the one year period from September 1995 through August 1996. This translates to an average of 37 lightning flashes occurring around the globe every second, which is well below the traditional estimate of 100 flashes per second. An average of 75% of the global lightning activity during the year occurs between 30' S and 30' N. An analysis of the annual lightning distribution reveals that an average of 82% of the lightning flashes occur over the continents and 18% over the oceans, which translates to an average land-ocean flash density ratio of nearly 11.

Christian, Hugh J.↗
NASA NTRS2002

[Activities of Harvard College Observatory]

With support from this grant, we have: 1) Developed techniques for improving wavelengths and f-values for singly and doubly charged ions of the iron group and have improved the accuracy of Fe III wavelengths by an order of magnitude. New Fe II f-values have also resulted from this work. 2) Measured line oscillator strengths and photoabsorption cross sections for UV molecular spectral feature that have been, or could be, used for searches for and detection of molecules in diffuse and translucent interstellar clouds and for determination of molecular column densities there. In addition, we have determined other molecular parameters -- line assignments, wavelengths, and line widths -- that are essential for theoretical descriptions of the abundance, fractionation, and excitation of interstellar molecules and for comparison of predictions with observations. 3) Measured A-values for spin-changing and other weak lines in low-Z ions. When A-values are available, these spectral features are useful for astrophysical plasma density and temperature diagnostics. Such lines are also used in interstellar abundance determinations in cases where the stronger allowed lines are saturated in astronomical spectra. 4) Taken an activist approach to ensuring that, (i), astronomers have ready access to our data, and, (ii), avenues of communication between data users and producers are strengthened.

Dalgarno, A.↗
NASA NTRS1998

Abundances of ethylene oxide and acetaldehyde in hot molecular cloud cores

We have searched for millimetre-wave line emission from ethylene oxide (c-C2H4O) and its structural isomer acetaldehyde (CH3CHO) in 11 molecular clouds using SEST. Ethylene oxide and acetaldehyde were detected through multiple lines in the hot cores NGC 6334F, G327.3-0.6, G31.41+0.31, and G34.3+0.2. Acetaldehyde was also detected towards G10.47+0.03, G322.2+0.6, and Orion 3'N, and one ethylene oxide line was tentatively detected in G10.47+0.03. Column densities and rotational excitation temperatures were derived using a procedure which fits the observed line intensifies by finding the minimum chi 2-value. The resulting rotational excitation temperatures of ethylene oxide and acetaldehyde are in the range 16-38 K, indicating that these species are excited in the outer, cooler parts of the hot cores or that the excitation is significantly subthermal. For an assumed source size of 20", the deduced column densities are (0.6-1)x10(14) cm-2 for ethylene oxide and (2-5)x10(14) cm-2 for acetaldehyde. The fractional abundances with respect to H2 are X[c-C2H4O]=(2-6)xl0(-10), and X[CH3CHO]=(0.8-3)x10(-9). The ratio X[CH3CHO]/X[c-C2H4O] varies between 2.6 (NGC 6334F) and 8.5 (G327.3-0.6). We also detected and analysed multiple transitions of CH3OH, CH3OCH3, C2H5OH, and HCOOH. The chemical, and possibly evolutionary, states of NGC 6334F, G327.3-0.6, G31.41+0.31, and G34.3+0.2 seem to be very similar.

Non-NASA Center↗