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At least 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
DOE OSTI2012

Brief 70 Nuclear Engineering Enrollments and Degrees, 2011: Summary Information

The survey includes degrees granted between September 1, 2010 and August 31, 2011. Enrollment information refers to the fall term 2011. The enrollment and degree data include students majoring in nuclear engineering or in an option program equivalent to a major. Thirty-two academic programs reported having nuclear engineering programs during 2011, and data was received from all thirty-two programs. The data for two nuclear engineering programs include enrollments and degrees in health physics options that are also reported in the health physics enrollments and degrees data.

96 KNOWLEDGE MANAGEMENT AND PRESERVATION↗
DOE OSTI2012

Health Physics Enrollments and Degrees, 2011: Summary Information

The survey includes degrees granted between September 1, 2010 and August 31, 2011. Enrollment information refers to the fall term 2011. The enrollment and degree data include students majoring in health physics or in an option program equivalent to a major. Twenty-four academic programs reported having health physics programs during 2011. The data for two health physics options within nuclear engineering programs are also included in the enrollments and degrees that are reported in the nuclear engineering enrollments and degrees data.

96 KNOWLEDGE MANAGEMENT AND PRESERVATION↗
DOE OSTI2013

Data Report: Meteorological and Evapotranspiration Data from Sagebrush and Pinyon Pine/Juniper Communities at Pahute Mesa, Nevada National Security Site, 2011-2012

Pahute Mesa is a groundwater recharge area at the Nevada National Security Site. Because underground nuclear testing was conducted at Pahute Mesa, groundwater recharge may transport radionuclides from underground test sites downward to the water table; the amount of groundwater recharge is also an important component of contaminant transport models. To estimate the amount of groundwater recharge at Pahute Mesa, an INFIL3.0 recharge-runoff model is being developed. Two eddy covariance (EC) stations were installed on Pahute Mesa to estimate evapotranspiration (ET) to support the groundwater recharge modeling project. This data report describes the methods that were used to estimate ET and collect meteorological data. Evapotranspiration was estimated for two predominant plant communities on Pahute Mesa; one site was located in a sagebrush plant community, the other site in a pinyon pine/juniper community. Annual ET was estimated to be 310±13.9 mm for the sagebrush site and 347±15.9 mm for the pinyon pine/juniper site (March 26, 2011 to March 26, 2012). Annual precipitation measured with unheated tipping bucket rain gauges was 179 mm at the sagebrush site and 159 mm at the pinyon pine/juniper site. Annual precipitation measured with bulk precipitation gauges was 222 mm at the sagebrush site and 227 mm at the pinyon pine/juniper site (March 21, 2011 to March 28, 2012). A comparison of tipping bucket versus bulk precipitation data showed that total precipitation measured by the tipping bucket rain gauges was 17 to 20 percent lower than the bulk precipitation gauges. These differences were most likely the result of the unheated tipping bucket precipitation gauges not measuring frozen precipitation as accurately as the bulk precipitation gauges. In this one-year study, ET exceeded precipitation at both study sites because estimates of ET included precipitation that fell during the winter of 2010-2011 prior to EC instrumentation and the precipitation gauges started collecting data in March 2011.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2012

Tracking the Sun V: An Historical Summary of the Installed Price of Photovoltaics in the United States from 1998 to 2011

As the deployment of grid-connected solar photovoltaic (PV) systems has increased, so too has the desire to track the installed price of these systems over time and by location, customer type, and system characteristics. This report helps to fill this need by summarizing trends in the installed price of grid-connected PV systems in the United States from 1998 through 2011, with preliminary data for 2012. The analysis is based on project-level data for more than 150,000 individual residential, commercial, and utility-scale PV systems, totaling more than 3,000 megawatts (MW) and representing 76% of all grid-connected PV capacity installed in the United States through 2011. The report describes installed price trends for residential and commercial PV systems, and another set of trends for utility-scale PV. In all cases, installed prices are identified in terms of real 2011 dollars per installed watt (DC-STC), prior to receipt of any direct financial incentives or tax credits.

14 SOLAR ENERGY↗
DOE OSTI2012

Energy and Economic Impacts of U.S. Federal Energy and Water Conservation Standards Adopted From 1987 Through 2011

This paper presents estimates of the key impacts of Federal energy and water conservation standards adopted from 1987 through 2011. The standards for consumer products and commercial and industrial equipment include those set by legislation as well as standards adopted by DOE through rulemaking. In 2011, the standards saved an estimated 3.2 quads of primary energy, which is equivalent to 3% of total U.S. energy consumption. The savings in operating costs for households and businesses totaled $\$ $42 billion. The average household saved $\$ $309 in operating costs as a result of residential and plumbing product standards. The estimated reduction in CO 2 emissions associated with the standards in 2011 was 176 million metric tons , which is equivalent to 3 percent of total U.S. CO 2 emissions. The estimated cumulative energy savings over the period 1990-2070 amount to 176 quads. Accounting for the increased upfront costs of more-efficient products and the operating cost (energy and water) savings over the products’ lifetime, the standards have a projected cumulative net present value (NPV) of consumer benefit of between $\$ $938 billion and $\$ $1,279 billion, using 7 percent and 3 percent discount rates, respectively. The water conservation standards, together with energy conservation standards that also save water, reduced water use by 1.5 trillion gallons in 2010, and will achieve cumulative water savings by 2040 of 51.4 trillion gallons. The estimated consumer savings in 2010 from reduced water use amounted to $\$ $10.8 billon. Standards set by legislation account for 47 percent of total cumulative primary energy savings and 55 to 66 percent of the total cumulative NPV (depending on which discount rate is used). Standards set by DOE rulemakings account for 53 percent of total cumulative primary energy savings and 34 to 45 percent of the total cumulative NPV.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗
DOE OSTI2018

SPRUCE Tree Growth Assessments of Picea and Larix in S1-Bog Plots and SPRUCE Experimental Plots, Beginning in 2011, Version 2

This data set reports tree growth measurements of mature Picea mariana and Larix laricina located in the S1-Bog permanent plots and the SPRUCE experimental study plots. Data have been collected annually from 2011 to 2024 (2011-02-23 to 2024-02-26) in late February/ early March to capture the productivity of the previous growing season (i.e. the February 2024 measurements track the 2023 growing season). Data collections are anticipated to continue through February of 2026 and this data set will be appended annually. Initial observations in 2011 included measurements of circumference at 1.3 m (diameter at breast height assessments; DBH) above the nominal bog hollow surface, tree heights and crown diameters. Subsequent annual measurements have focused on the measures of circumference at DBH. Supplemental tree height data collected via terrestrial lidar (Graham et al. 2019) were initiated in 2016 and have been maintained annually. Circumference measurements to the nearest 0.1 cm are converted to DBH in cm and basal area at DBH in (cm2). Tree height and crown diameter are measured to the nearest 0.1 m. This dataset contains one data file in comma separate (*.csv) format. User Note: In this Version 2, some previously released ‘Circum_Status’ values were updated to fix misread field measurements in previous years. The new data file, SPRUCE_Tree_Growth_Archive_20240620.csv, supersedes and replaces the previous, SPRUCE_Tree_Growth_Archive_20230327.csv.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2016

SPRUCE S1 Bog Porewater, Groundwater, and Stream Chemistry Data: 2011-2013

This data set reports the chemistry of S1 bog porewater, outlet stream water, and groundwater from upland wells from 2011 through 2013. These data provide information for studies of the biogeochemical status of the bog and surrounding groundwater aquifer. Porewater samples were collected from one nest of 6 piezometers installed in a hollow in the south end of the S1 bog to characterize solute chemistry depth profiles. Peat porewater was collected from piezometers that opened at 0, 0.3, 0.5, 1, 2, and 3 m depths below hollow surfaces. Samples were collected weekly (2011) or monthly (2012 & 2013) when the samplers were not frozen (typically June – November). Stream water was sampled weekly (2011-2013) from the outlet of the S1 bog (located on the southern edge of the bog). Four groundwater wells located in the uplands of the S1 watershed were sampled monthly in 2013. Bog water level data are also reported for the S1 bog. Water samples were analyzed for pH, specific conductivity, nutrient concentrations (ammonium, nitrate, soluble reactive phosphorus, total nitrogen, total phosphorus), cation concentrations (calcium, potassium, magnesium, sodium, aluminum, iron, manganese, silicon, strontium), anion concentrations (chloride, sulfate), and total organic carbon concentrations. The experimental work is to be conducted in a Picea mariana [black spruce] – Sphagnum spp. bog forest in northern Minnesota, 40 km north of Grand Rapids, in the USDA Forest Service Marcell Experimental Forest (MEF).

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2021

A Differential Measurement of Circumstellar Extinction for AA Tau’s 2011 Dimming Event

AA Tau is a classical T Tauri star with a highly inclined, warped circumstellar disk. For decades, AA Tau exhibited photometric and spectroscopic variabilities that were successfully modeled as occultations of the primary star by circumstellar material. In 2011, AA Tau entered an extended faint state, presumably due to enhanced levels of circumstellar dust. We use two sets of contemporaneous optical–near-IR (NIR) spectra of AA Tau, obtained in 2008 and 2014 December, to directly measure the wavelength-dependent extinction associated with the dust enhancement driving AA Tau’s 2011 optical fade. Taken alone, AA Tau’s apparent optical–NIR increased extinction curve cannot be fit well with standard extinction laws. At optical wavelengths, AA Tau’s dimming event is consistent with predictions of common extinction models for an increase of A {sub V} = 2, but no such model reproduces AA Tau’s color–color excess at NIR wavelengths. We show that veiling emission accounts for the apparent anomalous NIR extinction: after including this veiling flux, AA Tau’s dimming event is consistent with a standard A {sub V} = 2 extinction law across the full optical–NIR range. We also report an increase in AA Tau’s mid-IR flux since its 2011 fade and suggest that an increase in the height of AA Tau’s inner disk is the most likely explanation for both the IR brightening and the additional extinction along the line of sight. In addition to informing our understanding of AA Tau, this analysis demonstrates that caution should be exercised when inferring extinction (and stellar parameters) from the NIR color–color excess of young stars with measurable NIR veiling fluxes.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
NASA NTRS1993

STS-55 pad abort: Engine 2011 oxidizer preburner augmented spark igniter check valve leak

The STS-55 initial launch attempt of Columbia (OV102) was terminated on KSC launch pad A March 22, 1993 at 9:51 AM E.S.T. due to violation of an ME-3 (Engine 2011) Launch Commit Criteria (LCC) limit exceedance. The event description and timeline are summarized. Propellant loading was initiated on 22 March, 1993 at 1:15 AM EST. All SSME chill parameters and launch commit criteria (LCC) were nominal. At engine start plus 1.44 seconds, a Failure Identification (FID) was posted against Engine 2011 for exceeding the 50 psia Oxidizer Preburner (OPB) purge pressure redline. The engine was shut down at 1.50 seconds followed by Engines 2034 and 2030. All shut down sequences were nominal and the mission was safely aborted. The OPB purge pressure redline violation and the abort profile/overlay for all three engines are depicted. SSME Avionics hardware and software performed nominally during the incident. A review of vehicle data table (VDT) data and controller software logic revealed no failure indications other than the single FID 013-414, OPB purge pressure redline exceeded. Software logic was executed according to requirements and there was no anomalous controller software operation. Immediately following the abort, a Rocketdyne/NASA failure investigation team was assembled. The team successfully isolated the failure cause to the oxidizer preburner augmented spark igniter purge check valve not being fully closed due to contamination. The source of the contaminant was traced to a cut segment from a rubber O-ring which was used in a fine clean tool during valve production prior to 1992. The valve was apparently contaminated during its fabrication in 1985. The valve had performed acceptably on four previous flights of the engine, and SSME flight history shows 780 combined check valve flights without failure. The failure of an Engine 3 (SSME No. 2011) check valve to close was sensed by onboard engine instruments even though all other engine operations were normal. This resulted in an engine shutdown and safe sequential shutdown of all three engines prior to ignition of the solid boosters.

Source record↗
NASA NTRS2011

The Arctic Vortex in March 2011: A Dynamical Perspective

Despite the record ozone loss observed in March 2011, dynamical conditions in the Arctic stratosphere were unusual but not unprecedented. Weak planetary wave driving in February preceded cold anomalies in t he polar lower stratosphere in March and a relatively late breakup of the Arctic vortex in April. La Nina conditions and the westerly phas e of the quasi-biennial oscillation (QBO) were observed in March 201 1. Though these conditions are generally associated with a stronger vortex in mid-winter, the respective cold anomalies do not persist t hrough March. Therefore, the La Nina and QBO-westerly conditions cannot explain the observed cold anomalies in March 2011. In contrast, po sitive sea surface temperature anomalies in the North Pacific may ha ve contributed to the unusually weak tropospheric wave driving and s trong Arctic vortex in late winter 2011.

Hurwitz, Margaret M.↗
NASA NTRS2012

Dual-Polarimetric Radar-Based Tornado Debris Signatures and Paths Associated with Tornadoes Over Northern Alabama During the Historic Outbreak of 27 April 2011

A historic tornado and severe weather outbreak devastated much of the southeastern United States between 25 and 28 April 2011. On 27 April 2011, northern Alabama was particularly hard hit by 40 tornadoes, including 6 that reached EF-4 to EF-5 on the Enhanced Fujita damage scale. In northern Alabama alone, there were approximately 100 fatalities and hundreds of people who were injured or lost their homes during the havoc caused by these violent tornadic storms. Many of these tornadoes occurred within range of the University of Alabama in Huntsville (UAHuntsville) Advanced Radar for Meteorological and Operational Research (ARMOR, C-band dual-polarimetric). A unique capability of dual-polarimetric radar is the near-real time identification of lofted debris associated with ongoing tornadoes. The focus of this paper is to analyze the dual-polarimetric radar-inferred tornado debris signatures in 6 tornadoes in North Alabama on April 27, 2011. Several of these debris signatures were disseminated in real-time to the NWS Huntsville and local media to confirm storm spotter reports, confidence to enhance wording within warnings, and accurately pinpoint the locations of tornadoes for residents downstream of the storm. Also, the debris signature locations were used in post-event storm surveys to help locate areas of damage in regions where damage went unreported, or to help separate tornado tracks that were in close proximity to each other. Furthermore, the relative locations of the debris and damage paths for long track EF-4 and EF-5 tornadoes will be ascertained by careful comparison of the ARMOR analysis with NASA MODIS (Moderate Resolution Imaging Spectroradiometer) and ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) satellite imagery of the tornado damage scenes and the National Weather Service tornado damage surveys.

Carey, Lawrence D.↗
NASA NTRS2012

2011 NASA Range Safety Annual Report

Welcome to the 2011 edition of the NASA Range Safety Annual Report. Funded by NASA Headquarters, this report provides a NASA Range Safety overview for current and potential range users. As is typical with odd year editions, this is an abbreviated Range Safety Annual Report providing updates and links to full articles from the previous year's report. It also provides more complete articles covering new subject areas, summaries of various NASA Range Safety Program activities conducted during the past year, and information on several projects that may have a profound impact on the way business will be done in the future. Specific topics discussed and updated in the 2011 NASA Range Safety Annual Report include a program overview and 2011 highlights; Range Safety Training; Range Safety Policy revision; Independent Assessments; Support to Program Operations at all ranges conducting NASA launch/flight operations; a continuing overview of emerging range safety-related technologies; and status reports from all of the NASA Centers that have Range Safety responsibilities. Every effort has been made to include the most current information available. We recommend this report be used only for guidance and that the validity and accuracy of all articles be verified for updates. Once again the web-based format was used to present the annual report. We continually receive positive feedback on the web-based edition and hope you enjoy this year's product as well. As is the case each year, contributors to this report are too numerous to mention, but we thank individuals from the NASA Centers, the Department of Defense, and civilian organizations for their contributions. In conclusion, it has been a busy and productive year. I'd like to extend a personal Thank You to everyone who contributed to make this year a successful one, and I look forward to working with all of you in the upcoming year.

Dumont, Alan G.↗
NASA NTRS2012

Post-Flight EDL Entry Guidance Performance of the 2011 Mars Science Laboratory Mission

The 2011 Mars Science Laboratory was the first successful Mars mission to attempt a guided entry which safely delivered the rover to a final position approximately 2 km from its target within a touchdown ellipse of 19.1 km x 6.9 km. The Entry Terminal Point Controller guidance algorithm is derived from the final phase Apollo Command Module guidance and, like Apollo, modulates the bank angle to control the range flown. For application to Mars landers which must make use of the tenuous Martian atmosphere, it is critical to balance the lift of the vehicle to minimize the range error while still ensuring a safe deploy altitude. An overview of the process to generate optimized guidance settings is presented, discussing improvements made over the last nine years. Key dispersions driving deploy ellipse and altitude performance are identified. Performance sensitivities including attitude initialization error and the velocity of transition from range control to heading alignment are presented. Just prior to the entry and landing of MSL in August 2012, the EDL team examined minute tuning of the reference trajectory for the selected landing site, analyzed whether adjustment of bank reversal deadbands were necessary, the heading alignment velocity trigger was in union with other parameters to balance the EDL risks, and the vertical L/D command limits. This paper details a preliminary postflight assessment of the telemetry and trajectory reconstruction that is being performed, and updates the information presented in the former paper Entry Guidance for the 2011 Mars Science Laboratory Mission (AIAA Atmospheric Flight Mechanics Conference; 8-11 Aug. 2011; Portland, OR; United States)

Mendeck, Gavin F.↗
NASA NTRS2012

Observations of the Crab Nebula with the Chandra X-Ray Observatory During the Gamma-Ray Flare of 2011 April

Recently, using the AGILE and Fermi satellites, gamma-ray flares have been discovered from the direction of the Crab Nebula (Tavani et al. 2011, Abdo et al. 2011). We have been using the Chandra X-Ray observatory to monitor the Crab on a monthly cadence since just after the 2010 September gamma-ray flare. We were fortunate to trigger series of pre-planned target of opportunity observations during the 2011 April flare. We present the results of these observations and address some implications both for now and for the future.

Weisskopf, Martin C.↗
NASA NTRS2012

Radio-to-Gamma-Ray Monitoring of the Narrow-line Seyfert 1 Galaxy PMN J0948+0022 from 2008 to 2011

We present more than three years of observations at different frequencies, from radio to high-energy γ-rays, of the Narrow-Line Seyfert 1 (NLS1) Galaxy PMN J0948+0022 (z = 0.585). This source is the first NLS1 detected at energies above 100 MeV and therefore can be considered the prototype of this emerging new class of γ-ray emitting active galactic nuclei (AGN). The observations performed from 2008 August 1 to 2011 December 31 confirmed that PMN J0948+0022 generates a powerful relativistic jet, which is able to develop an isotropic luminosity at gamma-rays of the order of 1048 erg per second, at the level of powerful quasars. The evolution of the radiation emission of this source in 2009 and 2010 followed the canonical expectations of relativistic jets with correlated multiwavelength variability (gamma-rays followed by radio emission after a few months), but it was difficult to retrieve a similar pattern in the light curves of 2011. The comparison of gamma-ray spectra before and including 2011 data suggested that there was a softening of the highenergy spectral slope. We selected five specific epochs to be studied by modelling the broad-band spectrum, which are characterised by an outburst at gamma-rays or very low/high flux at other wavelengths. The observed variability can largely be explained by changes in the injected power, the bulk Lorentz factor of the jet, or the electron spectrum. The characteristic time scale of doubling/halving flux ranges from a few days to a few months, depending on the frequency and the sampling rate. The shortest doubling time scale at gamma-rays is 2.3 +/- 0.5 days. These small values underline the need of highly sampled multiwavelength campaigns to better understand the physics of these sources.

monitoring↗
NASA NTRS2015

Epidemiologic and Environmental Risk Factors of Rift Valley Fever in Southern Africa from 2008 to 2011

Background: Rift Valley fever (RVF) outbreaks have been associated with periods of widespread and above normal rainfall over several months. Knowledge on the environmental factors influencing disease transmission dynamics has provided the basis for developing models to predict RVF outbreaks in Africa. From 2008 to 2011, South Africa experienced the worst wave of RVF outbreaks in almost 40 years. We investigated rainfall associated environmental factors in southern Africa preceding these outbreaks. Methods: RVF epizootic records obtained from the World Animal Health Information Database (WAHID), documenting livestock species affected, location, and time, were analyzed. Environmental variables including rainfall and satellite-derived normalized difference vegetation index (NDVI) data were collected and assessed in outbreak regions to understand the underlying drivers of the outbreaks. Results: The predominant domestic vertebrate species affected in 2008 and 2009 were cattle, when outbreaks were concentrated in the eastern provinces of South Africa. In 2010 and 2011, outbreaks occurred in the interior and southern provinces affecting over 16,000 sheep. The highest number of cases occurred between January and April but epidemics occurred in different regions every year, moving from the northeast of South Africa toward the southwest with each progressing year. The outbreaks showed a pattern of increased rainfall preceding epizootics ranging from 9 to 152 days; however, NDVI and rainfall were less correlated with the start of the outbreaks than has been observed in eastern Africa. Conclusions: Analyses of the multiyear RVF outbreaks of 2008 to 2011 in South Africa indicated that rainfall, NDVI, and other environmental and geographical factors, such as land use, drainage, and topography, play a role in disease emergence. Current and future investigations into these factors will be able to contribute to improving spatial accuracy of models to map risk areas, allowing adequate time for preparation and prevention before an outbreak occurs.

Rift Valley Fever (RVF)↗
DOE OSTI2012

Design and Performance of Solar Decathlon 2011 High-Penetration Microgrid: Preprint

The U.S. Department of Energy Solar Decathlon challenges collegiate teams to design, build, and operate solar-powered houses that are cost-effective, energy-efficient, and attractive. The Solar Decathlon 2011 was held in Washington, D.C., from September 23 to October 2, 2011 . A high-penetration microgrid was designed, installed, and operated for the Solar Decathlon 2011 to grid-connect 19 highlyenergy-efficient, solar-powered competition houses to a single utility connection point. The capacity penetration of this microgrid (defined as maximum PV generation divided by maximum system load over a two-week period) was 74% based on 1-minute averaged data. Temporary, ground-laid conductors and electrical distribution equipment were installed to grid-connect the Solar Decathlon village,which included the houses as well as other electrical loads used by the event organizers. While 16 of the houses were connected to the 60 Hz microgrid, three houses from Belgium, China, and New Zealand were supplied with 50 Hz power. The design of the microgrid, including the connection of the houses powered by 50 Hz and a standby diesel generator, is discussed in this paper. In addition to theutility-supplied net energy meters at each house, a microgrid monitoring system was installed to measure and record energy consumption and PV energy production at 1-second intervals at each house. Bidirectional electronic voltage regulators were installed for groups of competition houses, which held the service voltage at each house to acceptable levels. The design and successful performance ofthis high-penetration microgrid is presented from the house, microgrid operator, and utility perspectives.

14 SOLAR ENERGY↗
DOE OSTI2012

2011 Annual Industrial Wastewater Reuse Report for the Idaho National Laboratory Site's Advanced Test Reactor Complex Cold Waste Pond

This report describes conditions, as required by the state of Idaho Industrial Wastewater Reuse Permit (LA 000161 01, Modification B), for the wastewater land application site at the Idaho National Laboratory Site's Advanced Test Reactor Complex Cold Waste Pond from November 1, 2010 through October 31, 2011. The report contains the following information: Facility and system description Permit required effluent monitoring data and loading rates Groundwater monitoring data Status of compliance activities Noncompliance and other issues Discussion of the facility's environmental impacts During the 2011 permit year, approximately 166 million gallons of wastewater were discharged to the Cold Waste Pond. This is well below the maximum annual permit limit of 375 million gallons. As shown by the groundwater sampling data, sulfate and total dissolved solids concentrations are highest near the Cold Waste Pond and decrease rapidly as the distance from the Cold Waste Pond increases. Although concentrations of sulfate and total dissolved solids are elevated near the Cold Waste Pond, both parameters were below the Ground Water Quality Rule Secondary Constituent Standards in the down gradient monitoring wells.

2011 Annual Industrial Wastewater Reuse Report↗