SEARCH · Engineering Papers
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.
The percent void of the Fort Saint Vrain (FSV) material is estimated to be 21.1% based on the volume of the gap at the top of the drums, the volume of the coolant channels in the FSV fuel element, and the volume of the fuel handling channel in the FSV fuel element.
In 2004, at the request of the Department of Energy, Sandia National Laboratories (Sandia) prepared a report, "Guidance on the Risk and Safety Analysis of Large Liquefied Natural Gas (LNG) Spills Over Water". That report provided a framework for assessing hazards and identifying approaches to minimize the consequences to people and property from an LNG spill over water. Because of increasing domestic U.S. supplies of natural gas and associated by products, such as liquefied propane gas (LPG), the United states Coast Guard requested that Sandia assess the general scale of possible hazards for a breach and spill of an LPG carrier. Because of the broad range of LPG carriers types -- refrigerated and pressurized, ships and barges, Sandia chose to focus this analysis on the larger LPG refrigerated systems. With cargo capacities ranging up to 100,000 m 3 , these types of ships can be expected to support potential increased LPG exports. Sandia assessed potential accidental and intentional threats, and based on LPG carrier configurations and designs, estimated potential breach sizes, spill rates and volumes, and conducted fire, vapor dispersion, and detonation hazard analyses. This report summarizes the analyses conducted, the expected range of potential hazards from an associated refrigerated LPG carrier spill over water, and risk management approaches to minimize consequences to people and property from such a spill.
This report provides a detailed description of the development of a reduced order model (ROM) that could be used for estimation of safe charge limits based on a computational fluid dynamics (CFD) parametric study. The ROM was developed to simulate leak events from a single side-wall duct penetration into a room and provide estimates of refrigerant concentration together with flammable volume fraction (FVF), accumulated fuel volume (AFV) and other outputs vs. time. The ROM is based on a range of seven parameters listed in Table ES1 and assumes that the AC unit air circulation blower is off. A total of 586 CFD “training” cases were run and used as the basis for development and training or calibration of the ROM. The regression analysis used to develop the ROM was performed in Tasmanian ( T oolkit for A daptive S tochastic M odeling A nd N on- I ntrusive A pproximatio N ). This is a tool developed at ORNL for high-dimensional integration, interpolation and parameter calibration. Comparison of the ROM vs. several CFD test cases (at points not used in the training set) showed maximum absolute and root mean square errors (RMSE) for FVF of 1.32% and 0.5%, respectively. Initial CFD runs were conducted to gauge the sensitivity of the results to each parameter. Based on the findings, the numbers of design of experiment (DoE) levels for each parameter was determined. Then, for each parameter, Tasmanian calculated the value of each level and defined a DoE of 586 unique CFD simulation cases.
Water is often used when there is the potential for air and water pollution from dust traveling across the landscape or through the air. If water is used for dust suppression at the Hanford Site’s Central Plateau, infiltration of the dust-suppression water has the potential to provide a hydraulic driving force to further mobilize contaminants in the vadose zone and accelerate their arrival at the water table. The scope of this investigation is to use modeling analyses to estimate contaminant mobilization as a function of volume and rate of water addition, subsurface properties, and contaminant properties. Four sets of simulations were conducted to investigate the impact of water application for dust suppression on solute transport in the vadose zone of the Hanford Site 200 Area and each set consists of several simulation cases. In first two sets of investigations (i.e., 200E and 200W), typical geologic profiles for the Hanford 200 East and 200 West Areas were used and contaminants were assumed to reside in the middle of the domain within the finer 10- to 20-m-thick layers. The third set of simulations (i.e., BY) investigated the impact of water applied for dust suppression on NO3 transport below the BY Cribs. The fourth set of simulations (i.e., S7) investigated the impact of applied water on I 129 transport below the S7 Crib. The main findings are summarized below. For all four sets of investigations, the water for dust suppression creates water pulses at higher flux rates than the base case (i.e., no water application). As more water is applied, the peak aqueous flux rates are higher. The impact of the water pulses on solute transport is dependent on the distribution of the solute in the vadose zone. When the solute is not distributed over a wide vertical range within the soil profile, the solute pulse arrives at the groundwater much later, as in the 200 East and 200 West simulations. In these cases, a larger volume of water translates to slightly earlier arrival times for the solute peak (up to 7 years) but has little impact on the peak flux rate and hence little impact on the solute concentration in the groundwater. When the solutes are vertically distributed throughout the soil profile, as they are for the BY and S7 Cribs, the solute pulse arrives at the groundwater at nearly the same time as the water pulse, possibly because solute resides in nearly all of the profile and hence diffusion plays a minor role in solute transport. In these cases, the peak solute flux rate is much higher than the value of the corresponding base case, ranging from 12% to 167% for the BY Cribs and from 2.4% to 32.5% for the S7 Crib. Because the vadose water flux is only a small fraction (about 2% for the base case) of the groundwater flux rate, a higher solute flux rate because of applied water indicates a near proportionally higher solute concentration in the groundwater. Among the cases, the peak solute flux arrival time varies up to 100 years for BY Cribs and only 7 years for the S7 Crib. When the same amount of water is applied, the variation of water application rate has very little impact on solute transport entering the water table.
In December 2021, SRR-E sent an ~185 mL sample identified as FPP-3 from a F-Area pump pit sump to SRNL for analysis. The sample was pale yellow in color and contained a small amount of suspended solids visually estimated to be less than 1% by volume. SRNL analysis indicated that the sample contained 4.4 E+05 dpm/mL Cs-137, 6.2 E+05 dpm/mL total beta activity, 9.3 E+02 dpm/mL beta activity following cesium removal, and below detectable levels of alpha activity following cesium removal. In addition, the sample contained 0.015 M free OH- and 947 μg total organic carbon/mL.
Savannah River Remediation Engineering (SRR-E) requested that the Savannah River National Laboratory (SRNL) analyze the Concentration, Storage, and Transfer Facility (CSTF) samples from the following Tank Farm areas: the sump encasement, catch tank, drain cell, and waste tank annulus. In general, these CSTF samples will be analyzed on an infrequent basis and analyses will include detection for total beta/gamma, total alpha activities, density, free hydroxide, and pH measurements. This report presents characterization results for the H-Area diversion box 1 sump (HDB-1) January 2022 sample. The sample was slightly brown with a small amount of suspended fine particulates visually estimated to be less than 1% by volume. The results are measurements for total gamma, total alpha, total beta, density, free hydroxide, and pH.
Forthcoming in the next decade of neutrino physics advancements is the construction of the Deep Underground Neutrino Experiment (DUNE), a long baseline neutrino oscillation experiment which has the potential to answer fundamental questions such as why there is more matter than antimatter in the universe, and ultimately why we exist at all. A prototype of this experiment, ProtoDUNE, sits in a charged particle test beam at the European Organization for Nuclear Research (CERN) and uses Liquid Argon time projection chambers to image interactions of these particles. ProtoDUNE Single-Phase (ProtoDUNESP) had positively charged hadrons as well as positrons in its initial 2018 beam data run. Because ProtoDUNE is a surface-based time projection chamber, it experiences a constant influx of cosmic rays. These cosmic rays ionize the liquid argon within the detector, resulting in an accumulation of slow moving positive ions towards the cathode. This local charge distribution results in electric field non uniformities, which can have a significant effect on the accuracy of the event reconstruction. This paper outlines a monte carlo simulation study which adapts methodology from the MicroBooNE experiment, another neutrino oscillation experiment, to derive electric field correction maps which can correct for distortions of the electric field within the detector. These correction maps accurately estimate the electric field throughout the detector volume and correct for uncertainties in reconstructed event data enabling for physics discoveries.
In this work, we investigate the size, thermal inertia, surface roughness, and geometric albedo of 10 Vesta family asteroids using the Advanced Thermophysical Model, based on the thermal-infrared data acquired by mainly NASA’s Wide-field Infrared Survey Explorer. Here, we show that the average thermal inertia and geometric albedo of the investigated Vesta family members are 42 J m{sup −2} s{sup −1/2} K{sup −1} and 0.314, respectively, where the derived effective diameters are less than 10 km. Moreover, the family members have a relatively low roughness fraction on their surfaces. The similarity in thermal inertia and geometric albedo among the V-type Vesta family members may reveal their close connection in origin and evolution. As the fragments of the cratering event of Vesta, the family members may have undergone a similar evolutionary process, thereby leading to very close thermal properties. Finally, we estimate their regolith grain sizes with different volume filling factors.
Atmospheric pressure at surface of Mars estimated from photoelectric measurements of eclipses of Phobos
A preliminary estimate is presented of the resources required to develop the basic general purpose walking boom manipulator system. It is assumed that the necessary full scale zero g test facilities will be available on a no cost basis. A four year development effort is also assumed and it is phased with an estimated shuttle development program since the shuttle will be developed prior to the space station. Based on delivery of one qualification unit and one flight unit and without including any ground support equipment or flight test support it is estimated (within approximately + or - 25%) that a total of 3551 man months of effort and $17,387,000 are required.
The volume consists of a text on theory, estimation, and measurement, together with its bibliography, the main body of numerical data and its references, and the material index. The text material assumes a role complementary to the main body of numerical data. The physics and basic concepts of thermal radiation are discussed in detail, focusing attention on treatment of nonmetallic materials: theory, estimation, and methods of measurement. Numerical data is presented in a comprehensive manner. The scope of coverage includes the nonmetallic elements and their compounds, intermetallics, polymers, glasses, and minerals. Analyzed data graphs provide an evaluative review of the data. All data have been obtained from their original sources, and each data set is so referenced.
A number of appendices were presented, dealing with the following topics: (1) a summary of the recommendations for spectral band location from six studies and for six disciplines. (2) demonstration of the LANDSAT scenes required for a satellite of 18-day repeat cycle, and comparison of the data volume associated with scene transmission with the data volume based on length-of-swath estimates, (3) presentation of a sample of the potential user demand projected based on polar orbiter passes over Conus and Alaska, (4) presentation of the nominal and expanded user demands for both Conus and Alaska, (5) derivation of a mathematical relation, (6) tables giving cost calculations for certain data points, (7) presentation of the UOT G/T and link budgets for leased-transponder transmission alternative, and (8) flow charts of the simulation program.
Measurement accuracy goals of 2 cm rms range estimation error and 0.003 cm/sec rms range rate estimation error, with no more than 1 cm (range) static bias error are requirements for laser measurement systems to be used in planned space-based earth physics investigations. Constraints and parameters were defined for links between a high altitude, transmit/receive satellite (HATRS), and one of three targets: a low altitude target satellite, passive (LATS), and active low altitude target, and a ground-based target, as well as with operations with a primary transmit/receive terminal intended to be carried as a shuttle payload, in conjunction with the Spacelab program.
From an operational standpoint, the most significant item the classification and mensuration subsystem (CAMS) had to overcome in providing the acreage component of the wheat production estimates for LACIE was the scope (segment volume processing required). Peak processing requirements per day increased from 16 to 20 for phase 1 with 700 total segments, to 35 to 40 per day for phase 2 with 1700 total segments, to 75 to 80 per day for phase 3 with 3000 total segments. Key issues regarding interrelationships between man and machines were identified during phase 1 using first generation technology. Procedure 1, tested and evaluated during phase 2 and continued through the initial phase 3 processing period for winter wheat, showed the need for software modification, procedures development, and analyst training. CAMS operations are described with emphasis on the training backgrounds of the analysts, the available data, and the labeling logic.
The requirements for future data systems for earth resource observation data are examined. Estimates are made for both expected data volumes and data delivery requirements. Research and development activities presently underway are described, including (1) high-speed processors such as the massively parallel processor; (2) data storage systems, including optical disk configurations and (3) distributed data systems such as high-speed local networks and the applications data service system.
A strain-based fatigue life prediction method is proposed for an intermetallic matrix composite (IMC) under tensile cyclic loadings at elevated temperatures. Styled after the Universal Slopes method, the model utilizes the composite's tensile properties to estimate fatigue life. Factors such as fiber volume ratio, number of plys and temperature dependence are implicitly incorporated into the model through these properties. The model constants are determined by using unidirectional fatigue data at temperatures of 425 and 815 C. Fatigue lives from two independent sources are used to verify the model at temperatures of 650 and 760 C. Cross-ply lives at 760 C are also predicted. It is demonstrated that the correlation between experimental and predicted lives is within a factor of two.
A strain-based fatigue life prediction method is proposed for an intermetallic matrix composite (IMC) under tensile cyclic loadings at elevated temperatures. Styled after the 'Universal Slopes' method, the model utilizes the composite's tensile properties to estimate fatigue life. Factors such as fiber volume ratio (Vf), number of plys and temperature dependence are implicitly incorporated into the model through these properties. The model constants are determined by using unidirectional fatigue data at temperatures of 425 and 815 C. Fatigue lives from two independent sources are used to verify the model at temperatures of 650 and 760 C. Cross-ply lives at 760 C are also predicted. It is demonstrated that the correlation between experimental and predicted lives is within a factor of two.
On a global scale, forests represent most of the terrestrial standing biomass (80 to 90 percent). Thus, natural and anthropogenic change in forest covers can have major impacts not only on local ecosystems but also on global hydrologic, climatic, and biogeochemical cycles that involve exchange of energy, water, carbon, and other elements between the earth and atmosphere. Quantitative information on the state and dynamics of forest ecosystems and their interactions with the global cycles appear necessary to understand how the earth works as a natural system. The information required includes the lateral and vertical distribution of forest cover, the estimates of standing biomass (woody and foliar volume), the phenological and environmental variations and disturbances (clearcutting, fires, flood), and the longer term variations following deforestation (regeneration, successional stages). To this end, seasonal, annual, and decadal information is necessary in order to separate the long term effects in the global ecosystem from short term seasonal and interannual variations. Optical remote sensing has been used until now to study the forest cover at local, regional, and global scales. Radar remote sensing, which provides recent SAR data from space on a regular basis, represents an unique means of consistently monitoring different time scales, at all latitudes and in any atmospheric conditions. Also, SAR data have shown the potential to detect several forest parameters that cannot be inferred from optical data. The differences--and complementarity--lie in the penetration capabilities of SAR data and their sensitivity to dielectric and geometric properties of the canopy volume, whereas optical data are sensitive to the chemical composition of the external foliar layer of the vegetation canopy.