Search NASA⌕ Search

SEARCH · Search NASA

Results for “DR.”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 37 records · Page 2
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

NLRP1 deficiency attenuates diabetic retinopathy (DR) in mice through suppressing inflammation response

Highlights: • NLRP1 expression was increased in retina of diabetic mice. • NLRP1 deletion attenuates STZ-induced diabetic retinopathy. • Knockout of NLRP1 reduces inflammation and alleviates diabetic retinopathy in STZ mice. • Suppression of NLRP1 restrains inflammation in high fructose-incubated retinal ganglion cells. Diabetic retinopathy (DR) is the common cause of diabetic vascular complications. The NOD-like receptor (NLR) family, pyrin domain containing 1 (NLRP1), also known as NALP1, inflammasome is the first member of the NLR family to be discovered, playing an important role in inflammatory response. However, its effect on DR development has not been reported. In the study, the wild type (WT) and NLRP1{sup −/−} mice were injected with streptozotocin (STZ) to induce DR. The results indicated that NLRP1{sup −/−} significantly increased bodyweight reduction and decreased blood glucose levels induced by STZ. WT/DR mice exhibited higher levels of NLRP1 in retinas. NLRP1{sup −/−} ameliorated retinal abnormalities in DR mice using H&E staining. In addition, attenuated avascular areas and neovascular tufts were also observed in NLRP1{sup −/−}/DR mice. The levels of pro-inflammatory cytokines in serum and retinas were highly induced in WT/DR mice, whereas being markedly reduced by NLRP1{sup −/−}. In addition, vascular endothelial growth factor (VEGF) and Iba1 expressions induced by STZ in serum or retinas were significantly down-regulated in NLRP1{sup −/−}/DR mice. Consistently, NLRP1{sup −/−} attenuated ASC and Caspase-1 expressions in retinas of DR mice. Compared to WT/DR group, NLRP1{sup −/−} markedly decreased retina p-nuclear factor-κB (NF-κB), interleukin-1β (IL-1β) and IL-18 levels. And similar results were confirmed in vitro that suppressing NLRP1/ASC inflammasome ameliorated inflammatory response in fructose-treated retinal ganglion cells. The results above indicated that the modulation of NLRP1 inflammasome might be a promising strategy for DR therapy.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2014

Demonstration of automated price response in large customers in New York City using Auto-DR and OpenADR

Demand response (DR) – allowing customers to respond to reliability requests and market prices by changing electricity use from their normal consumption pattern – continues to be seen as an attractive means of demand-side management and a fundamental smart-grid improvement that links supply and demand. From October 2011 to December 2013, the Demand Response Research Center at Lawrence Berkeley National Laboratory, the New York State Energy Research and Development Authority, and partners Honeywell and Akuacom, have conducted a demonstration project enabling Automated Demand Response (Auto-DR) in large commercial buildings located in New York City using Open Automated Demand Response (OpenADR) communication protocols. In particular, this project focuses on demonstrating how the OpenADR platform, enabled by Akuacom, can automate and simplify interactions between buildings and various stakeholders in New York State and enable the automation of customers’ price response to yield bill savings under dynamic pricing. In this paper, the cost control opportunities under day-ahead hourly pricing and Auto-DR control strategies are presented for four demonstration buildings; present the breakdown of Auto-DR enablement costs; summarize the field test results and their load impact; and show potential bill savings by enabling automated price response under Consolidated Edison’s Mandatory Hourly Pricing (MHP) tariff. For one of the sites, the potential bill savings at the site’s current retail rate are shown. Facility managers were given granular equipment-level opt-out capability to ensure full control of the sites during the Auto-DR implementation. The expected bill savings ranged from 1.1% to 8.0% of the total MHP bill. The automation and enablement costs ranged from $70 to $725 per kW shed. The results show that OpenADR can facilitate the automation of price response, deliver savings to the customers and opt-out capability of the implementation retains control of the sites by facility managers.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2023

Modular adjuvant-free pan-HLA-DR-immunotargeting subunit vaccine against SARS-CoV-2 elicits broad sarbecovirus-neutralizing antibody responses

Subunit vaccines typically require co-administration with an adjuvant to elicit protective immunity, adding development hurdles that can impede rapid pandemic responses. To circumvent the need for adjuvant in a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) subunit vaccine, we engineer a thermostable immunotargeting vaccine (ITV) that leverages the pan-HLA-DR monoclonal antibody 44H10 to deliver the viral spike protein receptor-binding domain (RBD) to antigen-presenting cells. X-ray crystallography shows that 44H10 binds to a conserved epitope on HLA-DR, providing the basis for its broad HLA-DR reactivity. Adjuvant-free ITV immunization in rabbits and ferrets induces robust anti-RBD antibody responses that neutralize SARS-CoV-2 variants of concern and protect recipients from SARS-CoV-2 challenge. We demonstrate that the modular nature of the ITV scaffold with respect to helper T cell epitopes and diverse RBD antigens facilitates broad sarbecovirus neutralization. Our findings support anti-HLA-DR immunotargeting as an effective means to induce strong antibody responses to subunit antigens without requiring an adjuvant.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2023

At the interfaces of the hydrologic sciences: Connecting water, elements, ecosystems, and people through the major contributions of Dr. Emily Bernhardt

Here, in this paper, we describe the major contributions of Professor Emily Bernhardt to the hydrologic sciences. Dr. Bernhardt’s work addresses how carbon, nutrient, and contaminant dynamics respond to a wide range of environmental perturbations that alter hydrologic dynamics within and connectivity among ecosystems. Her research leverages intensive and extensive field sampling, experimental manipulations, macroscale data harmonization and exploration, and continental to global-scale synthesis activities to uncover key drivers and patterns of the impacts human perturbations have on water and elemental cycles. Dr. Bernhardt’s research program is defined by her ability to ask questions and use approaches that explicitly consider connectivity and interfaces in a variety of ways. Here, we highlight significant contributions from Dr. Bernhardt’s work, organized by connectivity, interfaces, and interactions among and across (1) elemental cycles, (2) ecosystems, (3) watersheds, (4) scales, and (5) disciplines. We conclude with a section on Dr. Bernhardt’s impact on the hydrologic sciences and beyond through her exceptional dedication to mentorship, engagement, and service.

58 GEOSCIENCES↗
DOE OSTI2024

Celebrating Notable Advances in Compound Semiconductors: A Tribute to Dr. Wladyslaw Walukiewicz

The Special Topic "Native Defects, Impurities and the Electronic Structure of Compound Semiconductors" is dedicated to Dr. Wladyslaw (Wladek) Walukiewicz, our esteemed colleague who passed away on November 9, 2022, at age 76. It is not often that a scientist is able to profoundly impact more than one to two scientific topics in their lifetime. Dr. Walukiewicz, a condensed matter theorist by training, arguably did that for at least four. While his scientific accomplishments tell the story of a successful career and valuable contributions, it does not convey the entire story. For the rest, one has only to look at the community of researchers he brought together across the globe. Dr. Walukiewicz conducted his work with curiosity, integrity, and respect for others that elevated those around him. Here, we pay tribute to Dr. Walukiewicz's ideas and the legacy he leaves behind.

defects↗
DOE OSTI2012

VERY LARGE ARRAY H I ZEEMAN OBSERVATIONS OF THE CYGNUS X REGION: DR 22 AND ON 2

We have used the Very Large Array to study the Zeeman effect in 21 cm H I absorption lines from two star-forming regions in the Cygnus X complex, DR 22 and ON 2. We measure the line-of-sight magnetic field toward these regions, finding B{sub los} = -84 {+-} 11 {mu}G toward the DR 22 H II region and B{sub los} < 50 {mu}G toward each of the two H II regions in ON 2. We interpret these results in terms of two different models. In one model, we assume that the H I Zeeman effect is a measure of magnetic fields in the associated molecular clouds. If so, then the DR 22 molecular cloud is magnetically subcritical, that is, magnetically dominated. The ON 2 molecular clouds are magnetically supercritical. In a second model, we assume that the H I Zeeman effect is a measure of magnetic fields in photon-dominated regions where the gas has been compressed (and the field amplified) by absorption of stellar radiation. We find that this second model, where the measured field strength has been affected by star formation, accounts well for the DR 22 H I Zeeman effect. This same model, however, overpredicts the magnetic field in ON 2. ON 2 may be a region where the magnetic field is energetically insignificant or where the field happens to lie nearly in the plane of the sky.

79 ASTRONOMY AND ASTROPHYSICS↗
NASA NTRS2001

The Research of Dr. Joanne Simpson: Fifty Years Investigating Hurricanes, Tropical Clouds and Cloud Systems

This AMS Meteorological Monographs is dedicated to Dr. Joanne Simpson for her many pioneering research efforts in tropical meteorology during her fifty-year career. Dr. Simpson's major areas of scientific research involved the "hot tower" hypothesis and its role in hurricanes, structure and maintenance of trade winds, air-sea interaction, and observations and the mechanism for hurricanes and waterspouts. She was also a pioneer in cloud modeling with the first one-dimensional model and had the first cumulus model on a computer. She also played a major role in planning and leading observational experiments on convective cloud systems. The launch of the Tropical Rainfall Measuring Mission (TRMM) satellite, a joint U.S.-Japan project, in November of 1997 made it possible for quantitative measurements of tropical rainfall to be obtained on a continuous basis over the entire global tropics. Dr. Simpson was the TRAM Project Scientist from 1986 until its launch in 1997. Her efforts during this crucial period ensured that the mission was both well planned scientifically and well engineered as well as within budget. In this paper, Dr. J. Simpson's nine specific accomplishments during her fifty-year career: (1) hot tower hypothesis, (2) hurricanes, (3) airflow and clouds over heated islands, (4) cloud models, (5) trade winds and their role in cumulus development, (6) air-sea interaction, (7) cloud-cloud interactions and mergers, (8) waterspouts, and (9) TRMM science, will be described and discussed.

Tao, W. -K.↗
NASA NTRSDate not supplied

Dissociative Recombination (DR) and Associative Ionization (AI) Cross Section Calculations for the NO+ + e yields N + O (2D+3P, 2P+3P, and 2D+1D) Reaction for Atmospheric Entry Modeling

During entry of a space craft into Earth atmosphere, the flow surrounding the vehicle becomes partially ionized leading to significant cation and free-electron production. Subsequently, electron impact excitation and dissociation form radiating excited state species that contribute to the heat load on the vehicle. While experimental data on selected total cross sections are available, few experiments address the need for accurate AI cross sections for metastable atomic states at the high temperatures realized in atmospheric re-entry. In order to maintain desired safety margins during atmospheric entry of a space vehicle, chemical reaction models need to accurately account for this process. For the present study, we have computed vibrationally resolved cross sections for the DR of NO+ for electron energies between 0.01 to 10 eV and apply microscopic reversibility to obtain the AI cross sections and rate coefficients. For the DR cross section calculations, we use state-of-the-art MRCI potential energy curves. The resulting adiabatic potential curves are transformed to a diabatic representation, which is used in time-dependent wave packet calculations to describe the nuclear motion of the dissociating cation upon collision with an electron. Based on the wave function evolution in time, these calculations provide T-matrix and cross sections for the DR including recombination into the low energy metastable atomic states. The DR and AI rate coefficients are compared with the available experimental data.

Ewa Papajak↗
DOE OSTI2015

Purification and characterization of DR_2577 (SlpA) a major S-layer protein from Deinococcus radiodurans

The protein DR_2577 is a major Surface layer component of the radio-resistant bacterium Deinococcus radiodurans. In the present study DR_2577 has been purified and its oligomeric profile characterized by means of size exclusion chromatography and gel electrophoresis. DR_2577 was found to be organized into three hierarchical orders characterized by monomers, stable dimers formed by the occurrence of disulfide bonds, and hexamers resulting from a combination of dimers. Finally, the structural implications of these findings are discussed providing new elements for a more integrated model of this S-layer.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2013

TEST REPORT #11: Compressor Calorimeter Test of R-410A Alternatives R-32, DR-5, and L-41a

As a contribution to the AHRI Low-GWP Alternative Refrigerants Evaluation Program (AREP), this study compares performance of alternative refrigerants R32, DR-5, and L-41A to that of refrigerant R-410A (baseline) in a scroll compressor designed for air-conditioning and heat pump applications. Compressor calorimeter tests were performed to evaluate the performance of the lower-GWP alternative refrigerants in place of the common refrigerant R-410A in a 36,000 Btu/hr compressor calorimeter using a compressor having a nominal rated capacity of 21,300 Btu/hr. Tests were conducted over a suction dew point temperature range of 10°F to 55°F in 5°F increments and a discharge dew point temperature range of 70°F to 140°F in 10°F increments. All the tests were performed with 20°F superheat, 40°F superheat and 65°F suction temperature. A liquid subcooling level of 15°F was maintained for all the test conditions. The tests showed that performance of these three lower-GWP alternative refrigerants is comparable to that of R-410A. For the 20°F superheat and 15°F subcooling test conditions, EERs of R32, DR-5, and L-41A were 90% to 99%, 96% to 99%, and 94% to 101%, respectively, compared to that of R-410A. Similarly, cooling capacities of R32, DR-5, and L-41A were 98% to 103%, 92% to 96%, and 84% to 92%, respectively, compared to that of R-410A.

Alternative Refrigerants↗
DOE OSTI2018

Surface Ice and Tholins on the Extreme Centaur 2012 DR{sub 30}

2012 DR{sub 30} is one of the known solar system objects with the largest aphelion distance, exceeding 2200 au, on a high inclination orbit (i = 78°). It has been recognized to be either a borderline representative of high inclination, high perihelion distance (HiHq) objects, or even a new class of bodies, similar to HiHq objects for orbit but with an aphelion in the inner Oort Cloud. Here, we present photometry using long-term data from 2000 to 2013 taken by the SDSS sky survey, ESO MPG 2.2 m and McDonald 2.1 m telescopes, and a visual+near-infrared spectrum taken with the Southern Astrophysical Research Telescope and Magellan telescopes, providing insights into the surface composition of this body. Our best fit suggests that the surface contains 60% of complex organics (30% of Titan and 30% of Triton tholins) with a significant fraction of ice (30%, including pure water and water with inclusions of complex organics) and 10% silicates. The models also suggest a low limit of amorphous carbons, and hence the fragmentation of long-chained complex organics is slower than their rate of generation. 2012 DR{sub 30} just recently passed the perihelion, and the long-term photometry of the object suggested ambiguous signs of activity, since the long-term photometric scatter well exceeded the supposed measurement errors and the expected brightness variation related to rotation. Photometric colors put 2012 DR{sub 30} exactly between dark neutral and red objects, thus it either can be in a transition phase between the two classes or have differing surface properties from these populated classes.

79 ASTRONOMY AND ASTROPHYSICS↗
NASA NTRS1986

High angular resolution infrared mapping of the compact H II regions W51 and DR 21/W75

Far-infrared maps of W51/G49.5-0.4, W51/G49.4-0.3, and the DR 21 W75 S regions are presented. The simultaneous 50 and 100 micron maps enable a determination of the dust temperature and density structure in these areas. In G49.5-0.4 a luminosity and dust column-density peak at the position of the W51-Main maser is found, suggesting that this is the dominant luminosity source in W51. In G49.4-0.3 three components associated with the three known 2.7 GHz sources are resolved. A comparison of the total far-infrared luminosity with the radio continuum brightness in both G49.5-0.4 and G49.4-0.3 shows that the ratio of Lyman continuum to total luminosity of the exciting stars in not consistent with excitation by a single ZAMS star if most of the Lyman continuum photons are being absorbed bay gas rather than dust. In DR 21 micron far-infrared data and some new 2-20 micron results reveal a region of hot dust associated with the 2 micron H2 emission to the east and west of DR 21. Finally, a new 1.5-100 micron 'protostellar' source 2 deg north of W75 S at the position of a 1 mm continuum peak is reported.

Harvey, P. M.↗
NASA NTRS2000

Summary of Symposium on Cloud Systems, Hurricanes and TRMM: Celebration of Dr. Joanne Simpson's Career, The First Fifty Years

A symposium celebrating the first 50 years of Dr. Joanne Simpson's career took place at the NASA/Goddard Space Flight Center from December 1 - 3, 1999. This symposium consisted of presentations that focused on: historical and personal points of view concerning Dr. Simpson's research career, her interactions with the American Meteorological Society, and her leadership in TRMM; scientific interactions with Dr. Simpson that influenced personal research; research related to observations and modeling of clouds, cloud systems and hurricanes; and research related to the Tropical Rainfall Measuring Mission (TRMM). There were a total of 36 presentations and 103 participants from the US, Japan and Australia. The specific presentations during the symposium are summarized in this paper.

Tao, W.-K.↗
NASA NTRS2006

Collected Papers in Structural Mechanics Honoring Dr. James H. Starnes, Jr.

This special publication contains a collection of structural mechanics papers honoring Dr. James H. Starnes, Jr. presented at the 46th AIAA/ASME/ASCE/AHS/ASC Structures, Structural Dynamics, and Materials Conference held in Austin, Texas, April 18-21, 2005. Contributors to this publication represent a small number of those influenced by Dr. Starnes' technical leadership, his technical prowess and diversity, and his technical breath and depth in engineering mechanics. These papers cover some of the research areas Dr. Starnes investigated, which included buckling, postbuckling, and collapse of structures; composite structural mechanics, residual strength and damage tolerance of metallic and composite structures; and aircraft structural design, certification and verification. He actively pursued technical understanding and clarity, championed technical excellence, and modeled humility and perseverance.

Knight, Norman F., Jr.↗
DOE OSTI2014

Fast DR: Controlling Small Loads over the Internet

Current state-of-the-art demand response systems are expensive due to extreme reliability constraints in telemetry, control, and metering. The typical cost of enabling a site for regulation services is between $50k and $80k. These costs are orders of magnitude too high for small loads to participate in high-value grid services. Traditional demand response (DR) schedules events in advance and provides basic on/off control. We developed fast DR measurement and communication technologies, which are scalable cost-effective demand response systems with sufficient reliability for real-time control and monitoring of loads over the internet, and we demonstrated an example system for under $100. We installed FastDR systems for lighting, motor, and thermostat control along with power metering at a total of 10 sites, including 6 commercial buildings and 4 residential buildings. This demonstration addressed the following important methodological questions: 1) Can we reliably control loads simultaneously and with low latency across multiple sites within a specified response time; 2) How reliable is using the internet or 4G cellular network as the mode of control and metering; and 3) Can existing Smart Meters provide data for real-time telemetry services. Testing shows fast DR is capable of control to response in 4 seconds and loads complete transition in seconds to less than one minute depending on load type. We demonstrated 4s regulation services and synchronized load control, and we successfully met specifications for ancillary services across the US. Telemetry via the 4G cellular network demonstrated 94.5% success rate, and residential Internet demonstrated a 98% success rate.

Kiliccote, Sila↗
DOE OSTI2019

The Effect of Chemical Composition and Processing Technology on the Microstructure, Texture and Earing Behavior of DR Tinplate

The influence of alloying elements and processing technology on the microstructure, crystallographic texture and earing propensity has been investigated in two kinds of DR tinplate differing in Ti content: steel A, no Ti addition, and steel B 0.015% added. The cementite distribution, second-phase particles and the content of dissolved carbon and nitrogen atoms were obtained by SEM, TEM and XPS, respectively. Since the two steels develop both a partial 〈110〉//RD fiber and a {111}//ND fiber, the relative intensities of the several vital texture components seem to differ visibly. There are three types of strengthening mechanisms involved here: strengthening by grain size reduction, solution strengthening and strain hardening. That the tensile strength of steel B is greater than A implies the third mode plays a dominant role in the strength increasing for the DR tinplate. The crystallographic texture of materials not only results in a “preferential orientation” of the mechanical property, but also takes the primary responsibility for ears forming during drawing. Increasing the second cold-rolled reduction is not favorable to reduce the ear height, but this situation seems to be ameliorable. The average ears height of steel B is smaller than that of A, which demonstrated a low level of solute atoms and an ideal texture characteristic before deformation could alleviate the adverse effect caused by an elevated second cold reduction.

36 MATERIALS SCIENCE↗
DOE OSTI2014

A UV-to-MIR monitoring of DR Tau: Exploring how water vapor in the planet formation region is affected by stellar accretion variability

Young stars are known to show variability due to non-steady mass accretion rate from their circumstellar disks. Accretion flares can produce strong energetic irradiation and heating that may affect the disk in the planet formation region, close to the central star. During an extreme accretion outburst in the young star EX Lupi, the prototype of EXor variables, remarkable changes in molecular gas emission from ∼1 AU in the disk have recently been observed. Here, we focus on water vapor and explore how it is affected by variable accretion luminosity in T Tauri stars. We monitored a young highly variable solar-mass star, DR Tau, using simultaneously two high/medium-resolution spectrographs at the European Southern Observatory Very Large Telescope: VISIR at 12.4 μm to observe water lines from the disk and X-shooter covering from 0.3 to 2.5 μm to constrain the stellar accretion. Three epochs spanning timescales from several days to several weeks were obtained. The accretion luminosity was estimated to change within a factor of ∼2 and no change in water emission was detected at a significant level. In comparison with EX Lupi and EXor outbursts, DR Tau suggests that the less long-lived and weaker variability phenomena typical of T Tauri stars may leave water at planet-forming radii in the disk mostly unaffected. We propose that these systems may provide evidence for two processes that act over different timescales: ultraviolet photochemistry in the disk atmosphere (faster) and heating of the deeper disk layers (slower).

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2015

SU-D-204-07: Comparison of AAPM TG150 Draft Image Receptor Tests with Vendor Automated QC Tests for Five Mobile DR Units

Purpose: To determine the consistency of digital detector (DR) tests recommended by AAPM TG150 and tests provided by commercially available DirectView Total Quality Tool (TQT). Methods: The DR tests recommended by the TG150 Detector Subgroup[1] were performed on 4 new Carestream DRX-Revolution and one Carestream DRX1C retrofit of a GE AMX-4 that had been in service for three years. After detector calibration, flat-field images plus images of two bar patterns oriented parallel and perpendicular to the A-C axis, were acquired at conditions recommended by TG150. Raw images were harvested and then analyzed using a MATLAB software previously validated[2,3,4]. Data were analyzed using ROIs of two different dimensions: 1) 128 x 128 ROIs matching the detector electronics; and 2) 256 x 256 ROIs, each including 4 adjacent smaller ROIs. TG150 metrics from 128 x 128 ROIs were compared to TQT metrics, which are also obtained from 128 x 128 ROIs[5]. Results: The results show that both TG150 and TQT measurements were consistent among these detectors. Differences between TG150 and TQT values appear systematic. Compared with 128 x 128 ROIs, noise and SNR non-uniformity were lower with 256 x 256 ROIs, although signal non-uniformity was similar, indicating detectors were appropriately calibrated for gain and offset. MTF of the retrofit unit remained essentially the same between 2012 and 2015, but was inferior to the new units. The older generator focal spot is smaller (0.75mm vs. 1.2mm), and the SID for acquisition is 182cm as well, so focal spot dimensions cannot explain the difference. The difference in MTF may be secondary to differences in generator X-ray spectrum or by unannounced changes in detector architecture. Further investigation is needed. Conclusion: The study shows that both TG150 and TQT tests are consistent. The numerical value of some metrics are dependent on ROI size.

60 APPLIED LIFE SCIENCES↗