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NASA NTRS2020

Recommendations for Using Noise Monitors to Estimate Noise Exposure During X-59 Community Tests

A low fidelity simulation approach is used to explore how to place and use noise monitors during X-59 QueSST community tests, where people’s annoyance to the noise produced by the X-59 aircraft will be gathered. Several recommendations are provided including: 1) the desired number of sparsely spaced noise monitor sites within the survey area, 2) whether to group and average measurements across multiple noise monitors located at a site, 3) what spacing should be used if grouped noise monitors are used, 4) an approach to mitigate ambient noise contamination at the measurement sites, 5) a method to combine empirical and predicted dose estimates to provide a single dose estimate for respondents, and 6) assessing how changes in turbulence intensity and array configuration affect dose uncertainty. To make these recommendations, the error that is expected when fitting contrived, smoothly varying sonic boom “reference exposure surfaces” is studied when a spatially sparse and scattered set of samples is used as responses for the fit. The reference exposure surfaces mimic the sonic boom exposure at ground level that might be expected in the X-59 survey area in the absence of atmospheric turbulence, ambient noise, and other localized effects. The spatial extent of these surfaces varies and is representative of the different survey area sizes that might be expected during future X-59 community overflight tests. These contrived reference surfaces are sampled, and those reference samples are then perturbed to mimic atmospheric turbulence, ambient noise and other localized effects that might affect noise monitor measurements within overflown communities. Two different surface fitting methods are investigated when fitting these perturbed samples to approximate the reference surface. The first method uses interpolation between the perturbed data at the scattered sites to compute the fit. The second method fits a polynomial surface model to the perturbed data using ordinary least squares regression analysis. For both fitting methods, the root mean square fit error is computed from the pointwise difference between the fit surface and the reference surface as the count and configuration of the sites is varied while also averaging the error across many different realizations of both the smooth variation of the reference exposure surface and the random, localized perturbations at the sample sites. Different site configurations are compared using this error statistic to make the recommendations noted above. Additionally, the two fitting approaches (interpolation vs linear regression) are compared based on the fit error observed in these simulations. These analyses, comparisons, and recommendations should inform future decisions on the noise monitor placement and the methods used to analyze the noise monitor data that is collected during X-59 community overflights.

sonic boom↗

NASA NTRS1972

Spectral characteristics of normal and nutrient-deficient maize leaves

Reflectance, transmittance and absorbance spectra of normal and six types of mineral-deficient (N,P,K,S,Mg and Ca) maize (Zea mays L.) leaves were analyzed at 30 selected wavelengths along the electromagnetic spectrum from 500 to 2600 nm. Chlorophyll content and percent leaf moisture were also determined. Leaf thermograms were obtained for normal, N- and S- deficient leaves. The results of the analysis of variance showed significant differences in reflectance, transmittance and absorbance in the visible wavelengths among leaf numbers 3, 4, and 5, among the seven nutrient treatments, and among the interactions of leaves and treatments. In the reflective infrared wavelengths only treatments produced significant differences. The chlorophyll content of leaves was reduced in all deficiencies in comparison to controls. Percent moisture was increased in S-, Mg- and N- deficiencies. Positive correlation (r = 0.707) between moisture content and percent absorption at both 1450 and 1930 nm were obtained. Polynomial regression analysis of leaf thickness and leaf moisture content showed that these two variables were significantly and directly related (r = 0.894).

Al-Abbas, A. H.↗

DOE OSTI2015

Durable Airtightness in Single-Family Dwellings: Field Measurements and Analysis

Durability of the building envelope is important to new homes that are increasingly built with improved levels of airtightness. It is also important to weatherized homes such that energy savings from retrofit measures, such as air sealing, are persistent. This paper presents a comparison of air leakage measurements collected in November 2013 through March 2014, with two sets of prior data collected between 2001-2003 from 17 new homes located near Atlanta, GA, and 17 homes near Boise, ID that were weatherized in 2007-2008. The purpose of the comparison is to determine if there are changes to the airtightness of building envelopes over time. The air leakage increased in all but one of the new homes, with a mean increase of about 25%. A regression analysis was performed to describe the relationship between prior and current measurements in terms of normalized leakage (NL).

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

DOE OSTI2016

A mixed model approach for evaluating yield improvements in interspecific hybrids of shrub willow, a dedicated bioenergy crop

Lignocellulosic bioenergy crops such as shrub willow (Salix spp.) are expected to have a significant role in climate mitigation strategies. Yield is perhaps the most important trait for genetic selection and development of biomass feedstocks, but the selection process is complicated by the strong influence that environmental factors has on cultivar performance. Understanding the genotype-by-environment interactions using regional yield trials of shrub willow will inform future breeding efforts and improve the ability to make regionally-specific cultivar recommendations. Here we analyzed two yield trial datasets containing genotypes from successive rounds of breeding using a series of mixed models. Stability variance parameters were used together with overall yields to identify genotypes with stable yields or specific adaptation. Analysis of the first dataset revealed a group of triploid interspecific hybrid cultivars with exceptional performance and specific adaptation to either poor or good quality environments. The best performing cultivar showed a 14% yield improvement over the mean of the check cultivars. In the second dataset, new selections were assessed along with the top performing cultivars from dataset 1. New triploid hybrids had yields 19 to 27% greater than the check cultivar and exhibited similar patterns of specific adaptation as some of the selections from the first dataset. Partial least squares regression analysis indicated that top-yielding genotypes were favored in environments with higher temperatures and greater growing degree days. This analysis demonstrates incremental improvements in yield with successive rounds of breeding through the development of interspecific triploid hybrids.

09 BIOMASS FUELS↗

DOE OSTI2012

Iron deficiency is associated with increased levels of blood cadmium in the Korean general population: Analysis of 2008-2009 Korean National Health and Nutrition Examination Survey data

Introduction: We present data from the Korean National Health and Nutrition Examination Survey 2008-2009 on the distribution of blood cadmium levels and their association with iron deficiency in a representative sample of the adult Korean population. Methods: Serum ferritin was categorized into three levels: low (serum ferritin <15.0 {mu}g/L), low normal (15.0-30.0 {mu}g/L for women and 15.0-50.0 for men), and normal ({>=}30.0 {mu}g/L for women and {>=}50.0 for men), and its association with blood cadmium level was assessed after adjustment for various demographic and lifestyle factors. Results: Geometric means of blood cadmium in the low serum ferritin group in women, men, and all participants were significantly higher than in the normal group. Additionally, multiple regression analysis after adjusting for various covariates showed that blood cadmium was significantly higher in the low-ferritin group in women, men, and all participants compared with the normal group. We also found an association between serum ferritin and blood cadmium among never-smoking participants. Discussion: We found, similar to other recent population-based studies, an association between iron deficiency and increased blood cadmium in men and women, independent of smoking status. The results of the present study show that iron deficiency is associated with increased levels of blood cadmium in the general population.

54 ENVIRONMENTAL SCIENCES↗

NASA NTRS1983

Traction behavior of two traction lubricants

In the analysis of rolling-sliding concentrated contacts, such as gears, bearings and traction drives, the traction characteristics of the lubricant are of prime importance. The elastic shear modulus and limiting shear stress properties of the lubricant dictate the traction/slip characteristics and power loss associated with an EHD contact undergoing slip and/or spin. These properties can be deducted directly from the initial slope m and maximum traction coefficient micron of an experimental traction curve. In this investigation, correlation equations are presented to predict m and micron for two modern traction fluids based on the regression analysis of 334 separate traction disk machine experiments. The effects of contact pressure, temperature, surface velocity, ellipticity ratio are examined. Problems in deducing lubricant shear moduli from disk machine tests are discussed.

Loewenthal, S. H.↗

NASA NTRS1984

Elastic model of the traction behavior of two traction lubricants

Loewenthal, S. H.↗

DOE OSTI2015

Durable Airtightness in Single-Family Dwellings - Field Measurementsand Analysis

Here, durability of the building envelope is important to new homes that are increasingly built with improved levels of airtightness. It is also important to weatherized homes such that energy savings from retrofit measures, such as air sealing, are persistent. This paper presents a comparison of air leakage measurements collected in November 2013 through March 2014, with two sets of prior data collected between 2001-2003 from 17 new homes located near Atlanta, GA, and 17 homes near Boise, ID that were weatherized in 2007- 2008. The purpose of the comparison is to determine if there are changes to the airtightness of building envelopes over time. The air leakage increased in all but one of the new homes, with a mean increase of about 25%. The weatherized homes also showed an increase in the mean air leakage (12%). A regression analysis was performed to describe the relationship between prior and current measurements in terms of normalized leakage (NL). The best estimate of the ageing factor predicts a 15% increase in NL over ten years. Further analysis using ResDB data (LBNL’s Residential Diagnostic Database) showed the expected changes in air leakage if ageing were modelled. These results imply the need to examine the causes of increased leakage and methods to avoid them. This increase in leakage with time should be accounted for in long-term population-wide energy savings estimates, such as those used in ratings or energy savings programs.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

DOE OSTI2019

Altered fibrin clot properties in advanced lung cancer: strong impact of cigarette smoking

Background: Dense fibrin networks resistant to lysis have been reported in patients at high risk of thromboembolism. Little is known about fibrin clot properties in cancer. We investigated fibrin clot properties and their determinants in patients with inoperable lung cancer. Methods: We enrolled 150 patients with advanced lung cancer prior to therapy and 90 control subjects matched by age, sex, cardiovascular disease, and diabetes. Plasma clot permeability (K{sub s}), turbidimetric analysis of clot formation, clot lysis time (CLT), microparticle-associated tissue factor (MP-TF) activity, thrombin generation, and serum cotinine levels were determined. Results: Lung cancer patients, compared with controls, formed at a faster rate (− 8.1% lag phase) denser plasma fibrin networks (− 27.2% K{sub s}) that displayed impaired lysis (+ 26.5% CLT), along with 19.5% higher MP-TF activity and 100% higher peak thrombin generated, also after adjustment for potential confounders. Cotinine levels were associated with fibrin maximum absorbance (r = 0.20, p = 0.016) and K{sub s} (r = − 0.50, p < 0.0001) in cancer patients. On multivariate regression analysis, an increase in cotinine levels was a predictor of low K{sub s} (the lower quartile, < 5.8 × 10{sup −9} cm{sup 2}; odds ratio = 1.21 per 10 ng/ml, 95% confidence interval 1.02–1.46), but not CLT. Conclusion: Advanced lung cancer is associated with the prothrombotic plasma clot phenotype largely driven by smoking.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

DOE OSTI2024

Energy‐Water Asynchrony Principally Determines Water Available for Runoff From Snowmelt in Continental Montane Forests

ABSTRACT Changes in the volume, rate, and timing of the snowmelt water pulse have profound implications for seasonal soil moisture, evapotranspiration (ET), groundwater recharge, and downstream water availability, especially in the context of climate change. Here, we present an empirical analysis of water available for runoff using five eddy covariance towers located in continental montane forests across a regional gradient of snow depth, precipitation seasonality, and aridity. We specifically investigated how energy‐water asynchrony (i.e., snowmelt timing relative to atmospheric demand), surface water input intensity (rain and snowmelt), and observed winter ET (winter AET) impact multiple water balance metrics that determine water available for runoff (WAfR). Overall, we found that WAfR had the strongest relationship with energy‐water asynchrony (adjusted r 2 = 0.52) and that winter AET was correlated to total water year evapotranspiration but not to other water balance metrics. Stepwise regression analysis demonstrated that none of the tested mechanisms were strongly related to the Budyko‐type runoff anomaly (highest adjusted r 2 = 0.21). We, therefore, conclude that WAfR from continental montane forests is most sensitive to the degree of energy‐water asynchrony that occurs. The results of this empirical study identify the physical mechanisms driving variability of WAfR in continental montane forests and are thus broadly relevant to the hydrologic management and modelling communities.

Webb, Ryan William↗

NASA NTRS1972

Testing relativistic gravity theories using radio tracking data from planetary orbiting spacecraft.

We present a thorough analysis of a computational method for determining the numerical values of the relativity and other related dynamical parameters using two-way Doppler and ranging data from planetary orbiting spacecraft. The computational method consists of two parts. From Doppler data we first determine the earth-planet components of the position of the orbiting spacecraft relative to the center of gravity of the planet to high accuracy; adding the observed spacecraft range yields a range value to the center of the planet. These constructed earth-planet range data, referred to as normal points, are then treated as raw data in a regression analysis combined with planetary radar delay and meridian circle measurements to solve for the significant solar system dynamical parameters. The major errors sources in the planetary orbiter process are enumerated and their individual effects on the overall accuracy of the normal point accuracies are presented. The accuracies of the parameter estimates as a function of time, data sampling, and a priori assumptions are illustrated.

Jordan, J. F.↗

NASA NTRSDate not supplied

Shielding Considerations for CubeSat Structures During Solar Maximum

The purpose of this lessons learned is to communicate the utility of shielding in small spacecraft planning for the support of mission assurance and reliability. Numerous SmallSats have been flying in polar low earth orbit for scientific, communications, technology demonstrations, and imaging with academic, commercial, and government interests. Shielding has been part of mission assurance and reliability from the advent of long duration spacecraft missions. The Shields-1 CubeSat has been operating in polar low earth orbit since 16 December 2018 with atomic number (Z)-grade radiation shielding and demonstrates shielding effectiveness. Shields-1 has collected a representative example of solar minimum data in 2019 with 8 Teledyne dosimeters over varying shielding effectiveness. It serves as current experimental data and has been compared with NOVICE Shielding estimates using the AP8 –AE8 trapped radiation model with the Shields-1 CAD and generic CubeSat 3 unit (U) models. Using NOVICE model radiation analysis coding, the shielding effectiveness's, based on a generic CubeSat 3U structure with 4 electronic boards, were estimated for aluminum wall thicknesses ranging from 0.204 cmto4.44 cm (0.550 g/cm2–12.0 g/cm2) thick aluminum. For modeled polar orbiting spacecraft, solar maximum total ionizing dose (TID)increases by nearly a magnitude for thin-walled aluminum 0.550g/cm2-0.686 g/cm2(0.204 cm –0.254 cm) typical CubeSat structures. The shielding effectiveness by NOVICE Sigma estimates, which is a shielding sphere approximation around a detector, showed a linear relationship with wall thickness, which increased over the wall thickness by a ratio of 1.43 determined by linear regression analysis. Using NOVICE Adjoint Monte-Carlo Modeling of solar minimum and solar maximum with the inclusion of a worst-case solar particle event over a one year mission without geomagnetic shielding, the TID for minimum and maximum conditions for a generic 3U with a wall thickness of 0.254 cm is 158 RAD and 1540 RAD, respectively. The modeled total solar maximum TID is over estimated, because at low orbital latitudes a spacecraft will have shielding from Earth's magnetic field. However, TID will still be significant at high latitudes over the poles, where a spacecraft is exposed in a solar particle event. In contrast, to a thin walled generic 3U CubeSat, Shields-1 electronics enclosure has a shielding effectiveness of 21.3 g/cm2from NOVICE Sigma modeling and is expected to show reduced total ionizing dose increases during the present active Solar Cycle 25 period. Because solar particle events during solar maximum increase TID on electronic parts with thin-walled shielding in short periods of time, it is a mission assurance and reliability consideration on the spacecraft’s mission value versus adding shielding for risk reduction of premature spacecraft or instrument payload loss. Since the volumes of many instruments and system electronics have reduced with small spacecraft, shielding material costs and weight penalties have diminished. A small spacecraft project budget and schedule may limit traditional radiation-hardened part use and radiation testing requirements, where shielding can contribute to mission assurance and reliability with reduced costs.

Shields-1↗

DOE OSTI2018

Agricultural Burning and Air Quality over Northern India: A Synergistic Analysis using NASA’s A-train Satellite Data and Ground Measurements

In recent years, New Delhi, the capital city of India, has been ranked among the most polluted cities in the world in terms of air quality related to Particulate Matter (PM). In this paper, we show that the PM 2.5 , a major component of the measure of air quality, over New Delhi is strongly impacted by the agricultural fires in the north-western Indian states of Punjab and Haryana during the post-monsoon season (October and November). Using data from NASA’s A-train sensors (MODIS, OMI, and CALIOP) in conjunction with the ground-level PM 2.5 mass concentration measured at the US Embassy site in New Delhi (2013-2015), and back-trajectory analysis, it is shown that the smoke particles produced from numerous fires in Punjab and Haryana are advected over the national capital region under the influence of north-westerly winds, thereby greatly increasing the ground-level PM 2.5 from 50 µg/m -3 before the onset of burning in early October to as high as 300 µg/m -3 (24-hour averaged, 7-day running mean) during the peak burning period in early November. Relationships between the satellite measurements of fire counts and aerosols in the crop burning region and PM 2.5 over New Delhi are found to be strongly correlated. A linear regression analysis reveals that increments in the fire counts, aerosol optical depth, UV Aerosol Index, and aerosol absorption optical depth by 100, 1.0, 1.0, and 0.1 over the burning areas result in an increase in PM 2.5 by 20, 47, 134, and 142 µg/m -3 , respectively, over New Delhi. Back-trajectory analysis shows that about 74%, 62%, and 51% of total number of daily trajectories for altitudes 10 m, 500 m, and 1500 m, respectively, intercepted the biomass burning region before arriving at the receptor location in New Delhi; this further corroborates the transport mechanism observed in the satellite data. A 15-year long record of A-train satellite measurements shows an increasing number of agricultural fires (29% higher) and aerosol loading during the second half of the record (2009-2015) compared to that during the first half (2002-2008), which is one of the major concerns for the deteriorating air quality in the region.

54 ENVIRONMENTAL SCIENCES↗

NASA NTRSDate not supplied

Shielding Considerations for CubeSat Structures During Solar Maximum

The purpose of this lessons learned paper is to communicate the utility of shielding in small spacecraft planning for the support of mission assurance and reliability. Numerous SmallSats have been flying in polar low Earth orbit for science, communications, technology demonstrations, and imaging with academic, commercial, and government interests. Shielding has been part of mission assurance and reliability from the advent of long duration spacecraft missions. The Shields-1 CubeSat has been operating in polar low Earth orbit since 16 December 2018 with atomic number (Z)-grade radiation shielding and demonstrates shielding effectiveness. Shields-1 has collected a representative example of solar minimum data in 2019 with eight Teledyne µDosimeters over varying shielding effectivenesses. It serves as current experimental data and has been compared with NOVICE Shielding estimates using the AP8 – AE8 trapped radiation model with the Shields-1 CAD and generic CubeSat three unit (3U) models. Using NOVICE model radiation analysis coding, the shielding effectivenesses, based on a generic CubeSat 3U structure with four electronic boards, were estimated for aluminum wall thicknesses ranging from 0.204 cm to 4.44 cm (0.550 g/cm 2 to 12.0 g/cm 2 ). For modeled polar orbiting spacecraft, solar maximum total ionizing dose (TID) increases by nearly a magnitude for thin-walled aluminum 0.550-g/cm 2 - 0.686-g/cm 2 (0.204-cm – 0.254-cm) typical CubeSat structures. The shielding effectiveness estimated by NOVICE Sigma, which is a shielding sphere approximation around a detector, showed a linear relationship with wall thickness, which increased over the wall thickness by a ratio of 1.43 determined by linear regression analysis. Using NOVICE Adjoint Monte-Carlo Modeling of solar minimum and solar maximum with the inclusion of a worst-case solar particle event over a one-year mission without geomagnetic shielding, the TID for minimum and maximum conditions for a generic 3U with a wall thickness of 0.254 cm is 158 RAD and 1540 RAD, respectively. The modeled total solar maximum TID is over estimated, because at low orbital latitudes a spacecraft will have shielding from the Earth’s magnetic field. However, TID will still be significant at high latitudes over the poles, where a spacecraft is exposed in a solar particle event. In contrast to a thin-walled generic 3U CubeSat, the Shields-1 electronics enclosure has a shielding effectiveness of 21.3 g/cm 2 from NOVICE Sigma modeling and is expected to show reduced total ionizing dose increases during the present active Solar Cycle 25 period. Because solar particle events during solar maximum increase TID on electronic parts with thin-walled shielding in short periods of time, it is a mission assurance and reliability consideration on the mission value of the spacecraft versus adding shielding for risk reduction of premature spacecraft or instrument payload loss. Since the volumes of many instruments and system electronics have reduced with small spacecraft, shielding material costs and weight penalties have diminished. A small spacecraft project budget and schedule may limit traditional radiation-hardened part use and radiation testing requirements, where shielding can contribute to mission assurance and reliability with reduced costs.

Shields-1↗

NASA NTRS2018

Agricultural Burning and Air Quality over Northern India: A Synergistic Analysis Using NASA's A-Train Satellite Data and Ground Measurements

In the recent years, New Delhi, the capital city of India, has ranked among the most polluted cities in the world regarding its air quality related to the submicron Particulate Matter (PM(sub 2.5)). Using NASA's A-train satellite data (MODIS, OMI, and CALIOP), ground-level PM2.5 measured in New Delhi (2013-2016), and back-trajectory calculations, we show that the PM(sub 2.5). over New Delhi is strongly affected by the agricultural fires in the northwestern Indian states of Punjab and Haryana during the post-monsoon season (October and November). The mass concentration of PM2.5 escalates from ~50 μg m(exp -3) measured prior to the onset of residue burning in early October to as high as 300 μg m(exp -3) (24-hour averaged, 7- day running mean) during the peak burning period in early November. A linear regression analysis reveals that the variations in PM(sub 2.5) over New Delhi can be attributed to the concurrent changes in the satellite retrievals of fire counts and aerosols over the crop burning area. The back-trajectory analysis shows that most clusters (> 80%) of the northwesterly flow near the ground intercepted the crop burning region before arriving at the receptor location in New Delhi; this further corroborates the transport patterns inferred from the satellite data. A 15-year long satellite record (2002-2016) reveals an increasing trend in agricultural fires (~617 per year) and aerosol loading (0.031 and 0.04 per year in aerosol optical depth and UV aerosol index) in November. Increasing levels of crop residue burning and resulting particulate matter pollution at an alarming rate over northern India is a pressing concern demanding corrective measures to substantially reduce or completely diminish the crop burning through an effective residue management system.

Crop Residue Fires↗

DOE OSTI2013

Evidence of Progress - Measurement of Impacts of Australia's S&L Program from 1990-2010

Australia first put categorical energy efficiency labels on residential appliances in the mid-1980s, and the first Minimum Energy Performance Standards (MEPS) for refrigerators was implemented in 1999. Updated in 2005, these MEPS were aligned with US 2001 levels. Considered together, these actions set Australia apart as having one of the most aggressive appliance efficiency programs in the world. For these reasons, together with good data on product sales over time, Australia represents a potentially fruitful case study for understanding the dynamics energy efficiency standards and labeling (EES&L) programs impacts on appliance markets. This analysis attempts to distinguish between the impacts of labeling alone as opposed to MEPS, and to probe the time-dependency of such impacts. Fortunately, in the Australian case, detailed market sales data and a comprehensive registration system provides a solid basis for the empirical evaluation of these questions. This paper analyzes Australian refrigerator efficiency data covering the years 1993-2009. Sales data was purchased from a commercial market research organization (in this case, the GfK Group) and includes sales and average price in each year for each appliance model; this can be used to understand broader trends by product class and star rating category, even where data is aggregated. Statistical regression analysis is used to model market introduction and adoption of high efficiency refrigerators according to logistic adoption model formalism, and parameterizes the way in which the Australian programs accelerated adoption of high-efficiency products and phased out others. Through this analysis, the paper presents a detailed, robust and quantitative picture of the impacts of EES&L in the Australian case, but also demonstrates a methodology of the evaluation of program impacts that could form the basis of an international evaluation framework for similar programs in other countries.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

DOE OSTI2013

Evidence of progress. Measurement of impacts of Australia's S and L program from 1990-2010

Australia first put categorical energy efficiency labels on residential appliances in the mid-1980s, and the first Minimum Energy Performance Standards (MEPS) for refrigerators was implemented in 1999. Updated in 2005, these MEPS were aligned with US 2001 levels. Considered together, these actions set Australia apart as having one of the most aggressive appliance efficiency programs in the world. For these reasons, together with good data on product sales over time, Australia represents a potentially fruitful case study for understanding the dynamics energy efficiency standards and labeling (EES and L) programs impacts on appliance markets. This analysis attempts to distinguish between the impacts of labeling alone as opposed to MEPS, and to probe the time-dependency of such impacts. Fortunately, in the Australian case, detailed market sales data and a comprehensive registration system provides a solid basis for the empirical evaluation of these questions. This paper analyzes Australian refrigerator efficiency data covering the years 1993-2009. Sales data was purchased from a commercial market research organization (in this case, the GfK Group) and includes sales and average price in each year for each appliance model – this can be used to understand broader trends by product class and star rating category, even where data is aggregated. Statistical regression analysis is used to model market introduction and adoption of high efficiency refrigerators according to logistic adoption model formalism, and parameterizes the way in which the Australian programs accelerated adoption of high-efficiency products and phased out others. Through this analysis, the paper presents a detailed, robust and quantitative picture of the impacts of EES and L in the Australian case, but also demonstrates a methodology of the evaluation of program impacts that could form the basis of an international evaluation framework for similar programs in other countries.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

DOE OSTI2019

Detection of Spatiotemporal Prescription Opioid Hot Spots With Network Scan Statistics: Multistate Analysis

Background: Overuse and misuse of prescription opioids have become significant public health burdens in the United States. About 11.5 million people are estimated to have misused prescription opioids for nonmedical purposes in 2016. This has led to a significant number of drug overdose deaths in the United States. Previous studies have examined spatiotemporal clusters of opioid misuse, but they have been restricted to circular shaped regions. Objective: The goal of this study was to identify spatiotemporal hot spots of opioid users and opioid prescription claims using Medicare data. Methods: We examined spatiotemporal clusters with significantly higher number of beneficiaries and rate of prescriptions for opioids using Medicare payment data from the Centers for Medicare & Medicaid Services. We used network scan statistics to detect significant clusters with arbitrary shapes, the Kulldorff scan statistic to examine the significant clusters for each year (2013, 2014, and 2015) and an expectation-based version to examine the significant clusters relative to past years. Regression analysis was used to characterize the demographics of the counties that are a part of any significant cluster, and data mining techniques were used to discover the specialties of the anomalous providers. Results: We examined anomalous spatial clusters with respect to opioid prescription claims and beneficiary counts and found some common patterns across states: the counties in the most anomalous clusters were fairly stable in 2014 and 2015, but they have shrunk from 2013. In Virginia, a higher percentage of African Americans in a county lower the odds of the county being anomalous in terms of opioid beneficiary counts to about 0.96 in 2015. For opioid prescription claim counts, the odds were 0.92. This pattern was consistent across the 3 states and across the 3 years. A higher number of people in the county with access to Medicaid increased the odds of the county being in the anomalous cluster to 1.16 in both types of counts in Virginia. A higher number of people with access to direct purchase of insurance plans decreased the odds of a county being in an anomalous cluster to 0.85. The expectation-based scan statistic, which captures change over time, revealed different clusters than the Kulldorff statistic. Providers with an unusually high number of opioid beneficiaries and opioid claims include specialties such as physician’s assistant, nurse practitioner, and family practice. Conclusions: Our analysis of the Medicare claims data provides characteristics of the counties and provider specialties that have higher odds of being anomalous. The empirical analysis identifies highly refined spatial hot spots that are likely to encounter prescription opioid misuse and overdose. The methodology is generic and can be applied to monitor providers and their prescription behaviors in regions that are at a high risk of abuse.

60 APPLIED LIFE SCIENCES↗