Search NASA⌕ Search

SEARCH · Search NASA

Results for “total volume”

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 91 records · Page 5
All sourcesNASA NTRSDOE OSTI
NASA NTRS1976

Minimum wave drag for arbitrary arrangements of wings and bodies

Various arrangements of wings and bodies designed to provide favorable wave interference at supersonic speeds lead to the problem of determining the minimum possible value of the wave resistance obtainable by any disposition of the elements of an aircraft within a definitely prescribed region. Under the assumptions that the total lift and the total volume of the aircraft are given, conditions that must be satisfied if the drag is to be a minimum are found. The report concludes with a discussion of recent developments of the theory which lead to an improved understanding of the drag associated with the production of lift.

Jones, R. T.↗
NASA NTRS1976

Applications of space technology to developing nations

The use of imagery from the Landsat spacecraft for the monitoring and management of natural resources in developing countries is discussed. The Landsat imagery can be used to make cartographic maps at scales of 1:250,000 which meet the US National Map Accuracy Standards, providing a means of map updating to correct for river meanders or changing shorelines. The Landsat data can also be used in defining and measuring agricultural areas, identifying pest breeding areas, and monitoring irrigation practices and crop performance. Total volume estimates can be obtained in many cases for surface bodies of water, and subsurface water supplies can be detected from changes in vegetation in some instances.

Freden, S. C.↗
NASA NTRS1977

Advanced combined iodine dispenser and detector

A total weight of 1.23 kg (2.7 lb), a total volume of 1213 cu m (74 cu in), and an average power consumption of 5.5W was achieved in the advanced combined iodine dispenser/detector by integrating the detector with the iodine source, arranging all iodinator components within a compact package and lowering the parasitic power to the detector and electronics circuits. These achievements surpassed the design goals of 1.36 kg (3.0 lb), 1671 cu m (102 cu in) and 8W. The reliability and maintainability were improved by reducing the detector lamp power, using an interchangeable lamp concept, making the electronic circuit boards easily accessible, providing redundant water seals and improving the accessibility to the iodine accumulator for refilling. The system was designed to iodinate (to 5 ppm iodine) the fuel cell water generated during 27 seven-day orbiter missions (equivalent to 18,500 kg (40,700 lb) of water) before the unit must be recharged with iodine crystals.

Lantz, J. B.↗
NASA NTRS1977

Increase in effectiveness of low frequency acoustic liners by use of coupled Helmholtz resonators

Coupling of Helmholtz resonators in a low-frequency absorber array was studied as a means for increasing the effectiveness for absorbing low-frequency core engine noise. The equations for the impedance of the coupled-resonator systems were developed in terms of uncoupled-resonator parameters, and the predicted impedance for a parallel-coupled scheme is shown to compare favorably with measurements from a test model. In addition, attenuation measurements made in a flow duct on test coupled-resonator panels are shown to compare favorably with predicted values. Finally, the parallel-coupled concept is shown to give significantly more attenuation than that of a typical uncoupled resonator array of the same total volume.

Dean, L. W.↗
NASA NTRS1976

Water hyacinths for upgrading sewage lagoons to meet advanced wastewater treatment standards, part 2

Field tests using water hyacinths as biological filtration agents were conducted in the Mississippi gulf coast region. The plants were installed in one single cell and one multiple cell sewage lagoon systems. Water hyacinths demonstrated the ability to maintain BOD5 and total suspended solid (TSS) levels within the Environmental Protection Agency's prescribed limits of 30 mg/lBOD5 and 30 mg/l TSS. A multiple cell sewage lagoon system consisting of two aerated and one water hyacinth covered cell connected in series demonstrated the ability to maintain BOD5 and TSS levels below 30 mg/l year-round. A water hyacinth covered lagoon with a surface area of 0.28 hectare containing a total volume of 6.8 million liters demonstrated the capacity to treat 437,000 to 1,893,000 liters of sewage influent from 2.65 hectares of aerated lagoons daily and produce an effluent that met or exceeded standards year-round.

Wolverton, B. C.↗
NASA NTRS1977

Low cost miniature data collection platform

The development of the RF elements of a telecommunications package involved detailed study and analysis of concepts and techniques followed by laboratory testing and evaluation of designs. The design goals for a complete telecommunications package excluding antenna were a total weight of 300 grams, in a total volume of 400 cu cm with a capability of unattended operation for a period of six months. Of utmost importance is extremely low cost when produced in lots of 10,000. Early in the program it became apparent that a single Miniature Data Collection Platform would not satisfy all users. A single high efficiency system would not satisfy a user who had available a large battery capacity but required a low cost system. Conversely, the low cost system would not satisfy the end user who had a very limited battery capacity. A system design to satisfy these varied requirements was implemented by designing several versions of the system building blocks and then constructing three systems from these building blocks.

Source record↗
NASA NTRS1978

Direct evaluation of aerosol-mass loadings from multispectral extinction data

A formula is derived for the evaluation of the total volume of aerosol in a column, and hence for the aerosol columnar mass loading, from multispectral extinction data. This formula is exact in the 'anomalous diffraction' approximation, and reasonably accurate for Mie scattering, over a fairly wide range of refractive indices typical of real aerosols.

Box, M. A.↗
NASA NTRS1979

Thickness of western mare basalts

An isopach map of the basalt thickness in the western mare basins is constructed from measurements of the exposed external rim height of partially buried craters. The data, although numerically sparse, is sufficiently distributed to yield gross thickness variations. The average basalt thickness in Oceanus Procellarum and adjacent regions is 400 m with local lenses in excess of 1500 m in the circular maria. The total volume of basalt in the western maria is estimated to be in the range of 1.5 x 10 to the 6th power cu km. The chief distinction between the eastern and western maria appears to be one of basalt volumes erupted to the surface. Maximum volumes of basalt are deposited west of the central highlands and flood subjacent terrain to a greater extent than on the east. The surface structures of the western maria reflect the probability of a greater degree of isostatic response to a larger surface loading by the greater accumulation of mare basalt.

Dehon, R. A.↗
NASA NTRS1978

How thick are lunar mare basalts

It is argued that De Hon's estimates of the thickness of lunar mare basalts, made by analyzing 'ghost' craters on mare surfaces, were inflated as the result of the crater morphometric data of Pike (1977) to reconstruct rim heights of degraded craters. Crater rim heights of 82 randomly selected highland craters of various states of degradation were determined, and median rim height was compared to that of corresponding fresh impact structures. Results indicate that the thickness estimates of De Hon may be reduced by a factor of 2, and that the total volume of mare basalt produced throughout lunar history could be as little as 1-2 million cubic kilometers. A survey of geochemical and petrographic evidence indicates that lateral transport of regolith components over distances of much greater than 10 km is relatively inefficient; it is suggested that vertical mixing of a highland substrate underlying the basaltic fill may have had a primordial role in generating the observed mare width distributions and high concentrations of exotic components in intrabasin regoliths.

Hoerz, F.↗
NASA NTRS1980

Hydrothermal alteration of impact melt sheets with implications for Mars

A model of the interaction of water with an impact melt sheet is constructed to explain the presence of hydrothermal alteration, fluid flow channels, and the redistribution of volatile elements in terrestrial melt sheets. A calculation of the amount of water vaporized beneath a melt sheet with a large fraction of melt results in a maximum total steam/melt sheet ratio of 23% by weight. The model also applies to Martian impact melt sheets, which have a total volume greater than a global layer 60 m thick. Hydrothermal circulation of steam in Martian melt sheets may have produced iron-rich alteration clays, ferric hydroxides, and near-surface accumulations of salts. The ability of vapor-dominated hydrothermal systems to concentrate sulfate relative to chloride is consistent with the high sulfate to chloride ratio found in the Martian soil by the Viking landers. A major fraction of the Martian soil may consist of the erosion products of hydrothermally altered impact melt sheets.

Newsom, H. E.↗
NASA NTRS1985

A Preliminary Comparison of the Information Content of Data from the LANDSAT 4 Thematic Mapper and Multispectral Scanner

The thematic mapper (TM) on LANDSAT 4, acquires 6 spectral channels at 30 meter resolution as well as a thermal IR channel at 120 meter resolution. Because both MSS and TM can acquire data simultaneously, the advantages and disadvantages of the two instruments can be directly compared. The information content of the two instruments is compared for areas in a representative agricultural region. Although the parameter information does not equate in an obvious way to the value or utility of the data, it provides a basis for physical interpretation. By focusing on the redundancy of the digital data, the estimation of information content suggests possibilities for algorithms dealing with subsets of the image data, as well as transformations which reduce the total volume of data to be analyzed. To the degree that a satisfactory description by a reduced data set is possible, there exist implications both for design of future satellite instruments and for analysis procedures.

Price, J. C.↗
NASA NTRS1985

Estimates of Lava Eruption Rates at Alba Patera, Mars

The Martian volcanic complex Alba Patera exhibits a suite of well-defined, long and relatively narrow lava flows qualitatively resembling those found in Hawaii. Even without any information on the duration of the Martian flows, eruption rates (total volume discharge/duration of the extrusion) estimates are implied by the physical dimensions of the flows and the likely conjecture that Stephan-Boltzmann radiation is the dominating thermal loss mechanism. The ten flows in this analysis emanate radially from the central vent and were recently measured in length, plan areas, and average thicknesses by shadow measurement techniques. The dimensions of interest are shown. Although perhaps morphologically congruent to certain Hawaiian flows, the dramatically expanded physical dimensions of the Martian flows argues for some markedly distinct differences in lava flow composition for eruption characteristics.

Baloga, S. M.↗
NASA NTRS1985

An experimental and analytical study of the aerodynamic interference effects between two Sears-Haack bodies at Mach 2.7

Aerodynamic interference effects were studied for two slender, streamlined bodies of revolution at Mach 2.7. A wind tunnel investigation produced force and moment data and measurements of pressure distributions on the bodies. As these bodies remained parallel with each other and with the freestream flow, their relative lateral and longitudinal spacing were varied. Results of theoretical methods were used in the analysis of results. The interference effects between the two bodies yielded less total drag than a single body of equal total volume and the same length.

Bantle, J. W.↗
NASA NTRS1986

The chemical composition of comets and possible contribution to planet composition and evolution

The theory of cold aggregation of interstellar dust into comets is shown to support the ideas that comets provided not only a substantial part of the earth's water but also of its complex organic surface material. Comparison of the density of interstellar dust with meteor densities leads to the conclusion that comets are very fluffy bodies whose solid matter occupies no more than 2/5 of the total volume and possibly substantially less. This implies an extremely low comet albedo of about 0.05 in the visual even for slightly absorbing individual components.

Greenberg, J. Mayo↗
NASA NTRS1988

Some volcanologic aspects of Columbia River basalt volcanism relevant to the extinction controversy

The Columbia River Basalt Group is the youngest and most thoroughly studied flood-basalt province known; information about it should be relevant to questions about the possible relation of flood-basalt volcanism to mass extinctions. The group has a total volume of about 174,000 cu km and covers an area of about 164,000 sq km. It was erupted between 17.5 and 6 Ma, as measured by K-Ar and Ar-40/Ar-39 dates. Early eruptions formed the Imnaha Basalt. More than 85 percent of the group was produced during a 1.5 my period between 17 and 15.5 Ma, forming the Grande Ronde and greatly subordinate Picture Gorge Basalts. Later flows formed the Wanapum Basalt, which includes the well-known Roza Member, and the Saddle Mountains Basalt. Linear vent systems for many of the flows are known and are located only in the eastern third of the Columbia Plateau. No systematic migration of vents occurred throughout the 11.5 my period of activity; this and other considerations make it unlikely that the province is related to a hot spot. Model calculations based on observations that little cooling occurred during flow of hundreds of kilometers suggest eruption and emplacement durations of a few days. Some voluminous flows occur in all formations, but most such flows apparently were erupted during Grande Ronde time. The eruption and emplacement of more than 1,000 cu km of 1100 C basaltic lava on the surface within several days doubtless had at least local meteorologic effects. Whether the effects were broader can at present only be hypothesized. Grande Ronde Basalt and Picture Gorge Basalts contain moderately common but thin sedimentary interbeds between flows, whereas earlier and later formations contain numerous, locally thick sediment accumulations. Volcaniclastic debris derived from extra-plateau sources commonly occurs in the testbeds.

Swanson, Donald A.↗
NASA NTRS1990

The estimation of convective rainfall by area integrals. I - The theoretical and empirical basis. II - The height-area rainfall threshold (HART) method

A theory is developed which establishes the basis for the use of rainfall areas within present thresholds as a measure of either the instantaneous areawide rain rate of convective storms or the total volume of rain from an individual storm over its lifetime. The method is based upon the existence of a well-behaved pdf of rain rate either from the many storms at one instant or from a single storm during its life. The generality of the instantaneous areawide method was examined by applying it to quantitative radar data sets from the GARP Tropical Atlantic Experiment for South Africa, Texas, and Darwin (Australia). It is shown that the pdf's developed for each of these areas are consistent with the theory.

Rosenfeld, Daniel↗
NASA NTRS1991

An investigation of voids formation mechanisms and their effects on freeze and thaw processes of lithium and lithium fluoride

The mechanisms of void formation during the cooldown and freezing of lithium coolant within the primary loop of SP-100 type systems are investigated. These mechanisms are: (1) homogeneous nucleation; (2) heterogeneous nucleation; (3) normal segregation of helium gas dissolved in liquid lithium; and (4) shrinkage of lithium during freezing. To evaluate the void formation potential due to segregation, a numerical scheme that couples the freezing and mass diffusion processes in both the solid and liquid regions is developed. The results indicated that the formation of He bubbles is unlikely by either homogeneous or heterogeneous nucleation during the cooldown process. However, homogeneous nucleation of He bubbles following the segregation of dissolved He in liquid lithium ahead of the solid-liquid interface is likely to occur. Results also show that total volume of He void is insignificant when compared to that of shrinkage voids. In viewing this, the subsequent research focuses on the effects of shrinkage void forming during freezing of lithium on subsequent thaw processes are investigated using a numerical scheme that is based on a single (solid/liquid) cell approach. The cases of lithium-fluoride are also investigated to show the effect of larger volume shrinkage upon freezing on the freeze and thaw processes. Results show that a void forming at the wall appreciably reduces the solid-liquid interface velocity, during both freeze and thaw, and causes a substantial rise in the wall temperature during thaw. However, in the case of Li, the maximum wall temperature was much lower than the melting temperature of PWC-11, which is used as the structure material in the SP-100 system. Hence, it is included that a formation of hot spots is unlikely during the startup or restart of the SP-100 system.

El-Genk, Mohamed S.↗
NASA NTRS1991

Measures of large-scale structure in the CfA redshift survey slices

Variations of the counts-in-cells with cell size are used here to define two statistical measures of large-scale clustering in three 6 deg slices of the CfA redshift survey. A percolation criterion is used to estimate the filling factor which measures the fraction of the total volume in the survey occupied by the large-scale structures. For the full 18 deg slice of the CfA redshift survey, f is about 0.25 + or - 0.05. After removing groups with more than five members from two of the slices, variations of the counts in occupied cells with cell size have a power-law behavior with a slope beta about 2.2 on scales from 1-10/h Mpc. Application of both this statistic and the percolation analysis to simulations suggests that a network of two-dimensional structures is a better description of the geometry of the clustering in the CfA slices than a network of one-dimensional structures. Counts-in-cells are also used to estimate at 0.3 galaxy h-squared/Mpc the average galaxy surface density in sheets like the Great Wall.

De Lapparent, Valerie↗