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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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At least 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Outdoor Air Emissions, Land Use, and Land Cover around Schools on Tribal Lands

Children from tribes are more burdened with adverse respiratory well-being outcomes versus other U.S. children. The objectives of this study were to identify stressors from the built and natural environments for tribal school-aged children. Outdoor air concentrations around U.S. tribal schools were linked to National Emission Inventories; ecoregions and National Land Cover Database; and American Community Survey and school map layers. Nine school sites (seven tribes, five U.S. states) were in three ecoregions: North American Deserts, Northern Forests, and Mediterranean California. Closest emission sources were oil, gas, airport, and manufacturing facilities. Maximum annual outdoor air concentrations were measured for toluene at two schools (29 ppb and 15 ppb, 2011), located four miles from a solid waste landfill and eight miles from paperboard/saw mills. Maximum annual concentrations of metals in particulate matter 10 micrometers and smaller were highest for manganese (68 ng/m3, 2011). Schools were in mainly arid and heavily forested lands. Closest emission sources were predominantly off tribal lands. Measurements were limited (<30/year). Compared to schools off tribal lands, schools on tribal lands were further away from roadway sources. Future research may examine outdoor air quality around schools with more developed land and indoor air for tribal children’s total exposure.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2023

Using an Absolute Cavity Pyrgeometer to Calibrate Pyrgeometers Outdoors with Respect to the International System of Units

Accurate measurement of the atmospheric longwave irradiance is important for renewable energy and atmospheric science applications. Pyrgeometers are deployed outdoors all over the world to measure the atmospheric longwave irradiance and presently are calibrated with traceability to the interim standards for atmospheric longwave radiation measurement, the standards are based on four pyrgeometers and their average irradiance is the World InfraRed Standard Group (WISG) which is developed and maintained by The Physikalisch-Meteorologisches Observatorium Davos/World Radiation Center (PMOD/WRC). Since 2013 the InfraRed Integrating Sphere (IRIS) developed by PMOD/WRC and the Absolute Cavity Pyrgeometer (ACP) developed by the National Renewable Energy Laboratory (NREL) have been compared outdoors six times at different locations and the difference between the measured atmospheric longwave irradiance by ACP and IRIS was less than 2 W/m2 with traceability to the International System of Units (SI). During the six comparisons the irradiance measured by the interim WISG was 5 W/m2 lower than the irradiance measured by the average irradiance measured by the ACP and IRIS [1]. Based on this discrepancy, the World Meteorological Organization's Commission for Instruments and Methods of Observation (CIMO) recommended that the interim WISG should be adjusted to be traceable to SI units [2]. In anticipation of CIMO's expert team agreement on establishing the world reference using the average irradiance measured by ACP and IRIS in this article we describe a procedure to calibrate pyrgeometers with traceability to SI. One Absolute Cavity Pyrgeometer (ACP95F3) was used to calibrate four pyrgeometers traceable to SI units. Three Eppley PIRs and one Kipp&Zonen CG4 were originally calibrated with traceability to the interim WISG. Using the described procedure below, the responsivity of each pyrgeometer was then adjusted to match the irradiance measured by ACP. Outdoor data was collected during one clear sky nights monitored by the output thermopile voltage of ACP95F3. The irradiance measured by the PIRs was calculated using NREL equation and the CG4 using NREL equation and PMOD/WRC equation. Using the NREL equation, the calculated uncertainty (U_95) of the PIRs varied from 2.43 W/m2 to 2.67 W/m2, and for the CG4 using the NREL equation U_95 equals 1.97 W/m2, and using the PMOD equation U_95 equals 2.88 W/m2 with respect to SI.

International System of Units↗
NASA NTRS1980

Effect of field of view and monocular viewing on angular size judgements in an outdoor scene

Observers typically overestimate the angular size of distant objects. Significantly, overestimations are greater in outdoor settings than in aircraft visual-scene simulators. The effect of field of view and monocular and binocular viewing conditions on angular size estimation in an outdoor field was examined. Subjects adjusted the size of a variable triangle to match the angular size of a standard triangle set at three greater distances. Goggles were used to vary the field of view from 11.5 deg to 90 deg for both monocular and binocular viewing. In addition, an unrestricted monocular and binocular viewing condition was used. It is concluded that neither restricted fields of view similar to those present in visual simulators nor the restriction of monocular viewing causes a significant loss in depth perception in outdoor settings. Thus, neither factor should significantly affect the depth realism of visual simulators.

Denz, E. A.↗
NASA NTRS1981

Outdoor and laboratory testing of photovoltaic modules

An overview of outdoor and laboratory testing being applied to terrestrial photovoltaic modules is presented. Descriptions of the test procedures, examples of results, and discussion of the advantages and shortcomings of each approach are included. The test program consists of real-time outdoor testing of systems, modules and materials, and accelerated outdoor testing and laboratory testing of modules. The test results suggest that the various types of tests complement each other and contribute toward the objective of verifying the environmental suitability of the product. A description of representative photovoltaic systems operational in the U.S. in 1981 is presented, along with an identification, description, and physical inspection summary of JPL test module sites and a summary of degradation and failure data for the modules.

Hoffman, A.↗
NASA NTRS2010

Human Response to Low-Intensity Sonic Booms Heard Indoors and Outdoors

Test subjects seated inside and outside a house were exposed to low-intensity N-wave sonic booms during a 3-week test period in June 2006- The house was instrumented to measure the booms both inside and out. F-18 aircraft were flown to achieve a variety of boom overpressures from approximately .1 to .6 psf During four test days, seventy-seven test subjects heard the booms while seated inside and outside the house. Using the Magnitude Estimation methodology and artificial reference sounds ; the subjects rated the annoyance of the booms. Since the same subjects heard similar booms both inside and outside the house, comparative ratings of indoor and outdoor annoyance were obtained. For a given metric level, indoor subjects gave higher annoyance scores than outdoor subjects. For a given boom; annoyance scores inside were on average the same as those outside. In a post-test questionnaire, the majority of subjects rated the indoor booms as more annoying than the outdoor ones. These results are discussed in this paper.

Sullivan, Brenda M.↗
NASA NTRSDate not supplied

Comparing Two Weather-Robust Microphone Configurations for Outdoor Measurements

This paper discusses comparisons made between two ground-based outdoor microphone configurations. The first is known as the Compact Outdoor Unit for Ground-based Acoustical Recordings (COUGAR) and consists of an inverted microphone placed above a convex circular plate and covered by a large dome windscreen. The second configuration is the COUGARxt, where the “xt” simultaneously refers to an extra thick windscreen and an extra thin ground plate. COUGAR and COUGARxt were subjected to laboratory testing where their responses to sound were recorded at several different elevation and azimuthal angles. At almost all shown elevation angles, both configurations recorded levels that were within ±3 dB of a baseline measurement between 50 Hz – 20 kHz. At all shown azimuthal angles and over the same frequency range, both recorded levels within ±2 dB of the levels reported at an azimuthal angle of 0°, with COUGARxt having less variation than COUGAR. The configurations were also subjected to wind noise testing, where COUGARxt demonstrated superior wind noise rejection at low frequencies. The conclusion is that both configurations are suitable for outdoor acoustical measurements and that COUGARxt is the superior configuration, especially when measuring low-frequency noise.

sonic boom↗
DOE OSTI2023

Using an Absolute Cavity Pyrgeometer to Calibrate Pyrgeometers Outdoors with Respect to the International System of Units

Accurate measurement of the atmospheric longwave irradiance is important for renewable energy and atmospheric science applications. Pyrgeometers are deployed outdoors all over the world to measure the atmospheric longwave irradiance and presently are calibrated with traceability to the interim standards for atmospheric longwave radiation measurement, the standards are based on four pyrgeometers and their average irradiance is the World InfraRed Standard Group (WISG) which is developed and maintained by The Physikalisch-Meteorologisches Observatorium Davos/World Radiation Center (PMOD/WRC). Since 2013 the InfraRed Integrating Sphere (IRIS) developed by PMOD/WRC and the Absolute Cavity Pyrgeometer (ACP) developed by the National Renewable Energy Laboratory (NREL) have been compared outdoors six times at different locations and the difference between the measured atmospheric longwave irradiance by ACP and IRIS was less than 2 w/m2 with traceability to the International System of Units (SI). During the six comparisons the irradiance measured by the interim WISG was 5 w/m2 lower than the irradiance measured by the average irradiance measured by the ACP and IRIS [1]. Based on this discrepancy, the World Meteorological Organization's Commission for Instruments and Methods of Observation (CIMO) recommended that the interim WISG should be adjusted to be traceable to SI units [2]. In anticipation of CIMO's expert team agreement on establishing the world reference using the average irradiance measured by ACP and IRIS in this article we describe a procedure to calibrate pyrgeometers with traceability to SI. One Absolute Cavity Pyrgeometer (ACP95F3) was used to calibrate four pyrgeometers traceable to SI units. Three Eppley PIRs and one Kipp&Zonen CG4 were originally calibrated with traceability to the interim WISG. Using the described procedure below, the responsivity of each pyrgeometer was then adjusted to match the irradiance measured by ACP. Outdoor data was collected during one clear sky night monitored by the output thermopile voltage of ACP95F3. The irradiance measured by the PIRs and CG4 was calculated using NREL equation. The calculated uncertainty (U95) of the PIRs varied from 2.43 w/m2 to 2.67 w/m2 , and for the CG4 equals 1.97 w/m2 with respect to SI.

absolute cavity pyrgeometer↗
DOE OSTI2020

Update on NREL Outdoor Exposure Campaign of Solar Mirrors

Beginning in 2018, the National Renewable Energy Laboratory restarted exposure campaigns on new and archived samples as part of a multiyear project, some with outdoor exposure for more than a decade. By resuming exposure and collecting and analyzing data on thousands of samples going back decades, several goals can be advanced that can be difficult to determine within the timeline of most projects: 1) correlating an accelerated exposure campaign to outdoor aging, specifically with xenon arc lamp exposure chambers; 2) drawing conclusions between specific corrosion mechanisms and weather patterns; and 3) finding novel relationships between mirror composition and performance. In addition to building and mining a database, we will experiment with new characterization techniques, primarily focused on macroscopic and microscopic imaging. In introducing these techniques more broadly, it may be possible to reveal a more direct line between optical performance and exposure campaigns by better understanding the degradation mechanisms occurring.

characterization techniques↗
DOE OSTI2016

Estimating the Maximum Achievable Productivity in Outdoor Ponds: Microalgae Biomass Growth Modeling and Climate Simulated Culturing

To address the challenge of determining the maximum achievable monthly, seasonal, and annual biomass productivity for selected promising strains in outdoor ponds at any geographic location of interest, we developed the following four step integrated strategy. First, the strain is characterized in terms of its specific growth rate response to temperature and light, including darkness, as well as its light attenuation characteristics. Second, these species-specific parameters serve as inputs to PNNL’s biomass growth model that, in conjunction with the sunlight and pond water temperature predictions provided by PNNL’s Biomass Assessment Tool, is used to predict the respective biomass productivities for tens of thousands of hypothetical pond locations in the United States. Third, monthly and annual biomass productivity maps are created to identify the geographic location(s) of optimum biomass productivity and to generate light and water temperature “scripts” (time series) for hypothetical ponds at the best site(s). Finally, the maximum achievable biomass productivity for the given strain is confirmed by conducting culture experiments in PNNL’s indoor LED-lighted and temperature-controlled ponds under climate-simulated conditions, using the previously determined light and temperature scripts. This integrated strategy provides an efficient and low risk approach to screen promising strains for their potential to exhibit high biomass productivities, and to validate their model-predicted performance in climate-simulation ponds before transitioning to cultivation in outdoor raceways.

biomass assessment tool↗
DOE OSTI2021

The Outdoor Lighting Accelerator: Lighting the Way Forward (Final Report)

This final report outlines the work performed by DOE’s Better Buildings Outdoor Lighting Accelerator, through which cities, states, and regional groups explored best practice approaches to improve the way communities apply advanced outdoor lighting technologies in parking lots and highways. It describes the related work of participants, including designing regional bonding authorities or joint purchasing programs, financing streetlight upgrades, and more.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2019

Revealing Urban Morphology and Outdoor Comfort through Genetic Algorithm-Driven Urban Block Design in Dry and Hot Regions of China

In areas with a dry and hot climate, factors such as strong solar radiation, high temperature, low humidity, dazzling light, and dust storms can tremendously reduce people’s thermal comfort. Therefore, researchers are paying more attention to outdoor thermal comfort in urban environments as part of urban design. This study proposed an automatic workflow to optimize urban spatial forms with the aim of improvement of outdoor thermal comfort conditions, characterized by the universal thermal climate index (UTCI). A city with a dry and hot climate—Kashgar, China—is further selected as an actual case study of an urban block and Rhino & Grasshopper is the platform used to conduct simulation and optimization process with the genetic algorithm. Results showed that in summer, the proposed method can reduce the averaged UTCI from 31.17 to 27.43 °C, a decrease of about 3.74 °C, and reduce mean radiation temperature (MRT) from 43.94 to 41.29 °C, a decrease of about 2.65 °C.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2026

Outdoor Deployment Data for a Four-Terminal GaAs//Si Tandem Solar Mini-Module

This dataset contains the complete outdoor measurement and analysis data for a mechanically stacked, four-terminal (4T) gallium arsenide (GaAs)//silicon (Si) tandem solar mini-module deployed from October 2019 to January 2021 at the Solar Radiation Research Laboratory (SRRL) in Golden, Colorado, USA. The data support a performance modeling and degradation analysis framework for tandem photovoltaic devices, as described in the accompanying publication. The dataset includes: (1) current–voltage (J–V) characteristics of each sub-cell measured approximately every five minutes, with extracted performance parameters; (2) spectral irradiance from an EKO MS-710 WISER spectroradiometer, along with derived spectral mismatch ratios (SMR) and average photon energy (APE); (3) one-minute resolution meteorological data from the co-located SRRL weather station and GPS-derived precipitable water vapor (PWV); (4) pre-deployment laboratory characterization (external quantum efficiency, J–V curves, standard test conditions parameters); (5) outdoor-extracted temperature and PWV correction coefficients; and (6) PVcircuit equivalent-circuit simulation outputs used for model validation. Degradation rates of −4.1 ± 0.2 %/year (GaAs) and −2.5 ± 0.9 %/year (Si) were determined using a filtering and normalization methodology adapted for fixed-tilt tandem modules. All data are provided in open, portable formats (Apache Parquet, CSV, JSON) to enable full reproducibility of the published analysis.

14 SOLAR ENERGY↗
DOE OSTI2014

Direct Analysis of JV-Curves Applied to an Outdoor-Degrading CdTe Module (Presentation)

We present the application of a phenomenological four parameter equation to fit and analyze regularly measured current density-voltage JV curves of a CdTe module during 2.5 years of outdoor operation. The parameters are physically meaningful, i.e. the short circuit current density Jsc, open circuit voltage Voc and differential resistances Rsc, and Roc. For the chosen module, the fill factor FF degradation overweighs the degradation of Jsc and Voc. Interestingly, with outdoor exposure, not only the conductance at short circuit, Gsc, increases but also the Gsc(Jsc)-dependence. This is well explained with an increase in voltage dependent charge carrier collection in CdTe.

14 SOLAR ENERGY↗
DOE OSTI2017

The Impact of Indoor and Outdoor Radiometer Calibration on Solar Measurements

This study addresses the effect of calibration methodologies on calibration responsivities and the resulting impact on radiometric measurements. The calibration responsivities used in this study are provided by NREL's broadband outdoor radiometer calibration (BORCAL) and a few prominent manufacturers. The BORCAL method provides outdoor calibration responsivity of pyranometers and pyrheliometers at a 45 degree solar zenith angle and responsivity as a function of solar zenith angle determined by clear-sky comparisons to reference irradiance. The BORCAL method also employs a thermal offset correction to the calibration responsivity of single-black thermopile detectors used in pyranometers. Indoor calibrations of radiometers by their manufacturers are performed using a stable artificial light source in a side-by-side comparison of the test radiometer under calibration to a reference radiometer of the same type. These different methods of calibration demonstrated 1percent to 2 percent differences in solar irradiance measurement. Analyzing these values will ultimately enable a reduction in radiometric measurement uncertainties and assist in developing consensus on a standard for calibration.

14 SOLAR ENERGY↗
DOE OSTI2025

HANDBOOK BEST PRACTICES FOR ORGANIZING PUBLIC E WASTE COLLECTION EVENTS Indoor and Outdoor Settings

This handbook was created to share best practices of organizing public e-waste collection events in the United States. The steps and checklists outlined in this handbook have been drawn from Sunnking’s decade’s long experience of organizing large scale outdoor collection events in New York. These practices have been verified by INL and ECyclers of Idaho to work well for both indoor and outdoor events in Idaho at a smaller scale. Understanding that the local conditions vary significantly, we have compiled key deciding factors to share in this handbook. We hope that by following these steps, you will succeed in organizing your own events. Although e-waste events typically require careful logistics planning due to the nature of the materials, the experience is very rewarding to bring the community together.

Collection Event↗
DOE OSTI2013

Assessment of outdoor radiofrequency electromagnetic field exposure through hotspot localization using kriging-based sequential sampling

In this study, a novel methodology is proposed to create heat maps that accurately pinpoint the outdoor locations with elevated exposure to radiofrequency electromagnetic fields (RF-EMF) in an extensive urban region (or, hotspots), and that would allow local authorities and epidemiologists to efficiently assess the locations and spectral composition of these hotspots, while at the same time developing a global picture of the exposure in the area. Moreover, no prior knowledge about the presence of radiofrequency radiation sources (e.g., base station parameters) is required. After building a surrogate model from the available data using kriging, the proposed method makes use of an iterative sampling strategy that selects new measurement locations at spots which are deemed to contain the most valuable information—inside hotspots or in search of them—based on the prediction uncertainty of the model. The method was tested and validated in an urban subarea of Ghent, Belgium with a size of approximately 1 km{sup 2}. In total, 600 input and 50 validation measurements were performed using a broadband probe. Five hotspots were discovered and assessed, with maximum total electric-field strengths ranging from 1.3 to 3.1 V/m, satisfying the reference levels issued by the International Commission on Non-Ionizing Radiation Protection for exposure of the general public to RF-EMF. Spectrum analyzer measurements in these hotspots revealed five radiofrequency signals with a relevant contribution to the exposure. The radiofrequency radiation emitted by 900 MHz Global System for Mobile Communications (GSM) base stations was always dominant, with contributions ranging from 45% to 100%. Finally, validation of the subsequent surrogate models shows high prediction accuracy, with the final model featuring an average relative error of less than 2 dB (factor 1.26 in electric-field strength), a correlation coefficient of 0.7, and a specificity of 0.96. -- Highlights: • We present an iterative measurement and modeling method for outdoor RF-EMF exposure. • Hotspots are rapidly identified, and accurately characterized. • An accurate graphical representation, or heat map, is created, using kriging. • Random validation shows good correlation (0.7) and low relative errors (2 dB)

61 RADIATION PROTECTION AND DOSIMETRY↗
DOE OSTI2018

Lung function association with outdoor temperature and relative humidity and its interaction with air pollution in the elderly

Highlights: • We studied pulmonary effects of temperature and relative humidity in elderly. • Temperature and relative humidity were associated with decreased FEV1 and FVC. • The lag structure suggested that acute effects may last several days. • Effects of temperature and relative humidity were stronger on FVC than on FEV1. • Effects of temperature and relative humidity were amplified by black carbon exposure. While the effects of weather variability on cardio-respiratory mortality are well described, research examining the effects on morbidity, especially for vulnerable populations, is warranted. We investigated the associations between lung function and outdoor temperature (T in Celsius degrees (°C)) and relative humidity (RH), in a cohort of elderly men, the Normative Aging Study. Our study included 1103 participants whose forced vital capacity (FVC), forced expiratory volume in one second (FEV{sub 1}), and weather exposures were assessed one to five times during the period 1995–2011 (i.e. 3162 observations). Temperature and relative humidity were measured at one location 4 h to 7 days before lung function tests. We used linear mixed-effects models to examine the associations with outdoor T and RH. A 5-degree increase in the 3-day moving average T was associated with a significant 0.7% decrease (95%CI: −1.24, −0.20) in FVC and a 5% increase in the 7-day moving average RH was associated with a significant 0.2% decrease (95%CI: −0.40, −0.02) in FVC and FEV{sub 1}. The associations with T were greater when combined with higher exposures of black carbon with a 1.6% decrease (95%CI −2.2; −0.9) in FVC and a 1% decrease (95%CI −1.7; −0.4) in FEV{sub 1}. The relationships between T and RH and lung function were linear. No synergistic effect of T and RH was found. Heat and lung function are two predictors of mortality. Our findings suggest that increases in temperature and relative humidity are related to decreases in lung function, and such observations might be amplified by high black carbon levels.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2017

Adhesion and aerodynamic forces for the resuspension of non-spherical particles in outdoor environments

Particles deposited on an outdoor surface can be resuspended by wind gusts, become airborne, and be inhaled if small enough. If toxic or infectious, these particles may be dangerous for the populace health. It is therefore important to determine under which weather conditions a deposit of particle could be resuspended to implement the best response actions and plan clean-up. To this scope, one needs to consider the competing forces acting on the particle keeping it attached to the surface (gravity and adhesion) or trying to remove it (aerodynamic forces, i.e., lift and drag). Here, this article reviews the current understanding of the aforementioned forces for colloidal spherical particles and extends the existing theories to rod-shaped particles, representative for instance of Bacillus spores. In particular, for the adhesion force, the Derjaguin approximation was used and the adhesion force was computed from the radii of curvature of the particle and the surface at the point of closest approach. For the aerodynamic forces, we re-derived the equations for the drag and lift forces accounting for the shape of the particle. Both smooth and rough surfaces will be discussed, the former as idealized cases, the latter as more representative of real outdoor surfaces.

54 ENVIRONMENTAL SCIENCES↗