Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “new construction”

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 289 records · Page 16
All sourcesNASA NTRSDOE OSTI
NASA NTRS1973

Thailand national programme of the Earth Resources Technology Satellite

The author has identified the following significant results. ERTS-1 data has been used to delineate floating rice regions with a clear distinction between irrigated and nonirrigated areas and recognition of orchard and horitcultural crops. Alluvial fans marking the ancient river outlets in the northwestern portion of the Central Plain of Thailand and the shape and size of the flood plains in the central region have been identified and outlined. A new forestry map was constructed using band 5 and band 7 imagery combined with ground observations. A geologic map of Thailand has been constructed from ERTS imagery.

Cheosakul, P.↗
NASA NTRS1973

Design, fabrication, and performance of foil journal bearing for the brayton rotating unit

Foil bearings were designed and manufactured to replace pivoted-shoe journal bearings in an existing Brayton Cycle turbo-alternator-compressor. The design of this unconventional rotor support was accomplished within the constraints and space limitations imposed by the present machine, and the substitution of foil bearings was effected without changes or modification other machine components. A housing and a test rig were constructed to incorporate the new foil-bearing support into a unified assemble with an air-driven rotor and the gimbal-mounted thrust bearing, seals, and shrouds of an actual Brayton Rotating Unit. The foil bearing required no external pressure source, and stable self-acting rotation was achieved at all speeds up to 43,200 rpm. Excellent wipe-wear characteristics of the foil bearing permitted well over 1000 start-stop cycles with no deterioriation of performance in the entire speed range.

Licht, L.↗
NASA NTRS1973

Advanced high efficient liquid transport garments

The heat transfer characteristics, design, fabrication, and current and anticipated applications of a new liquid transport garment (LTG) are discussed. The new LTG is being constructed from highly efficient liquid transport modules which have been developed to replace the current tygon tubing networks for applications in Apollo and other liquid cooling garment designs.

Elkins, W.↗
NASA NTRS1976

Improved Einzel lenses

New insulator configuration simplifies construction of three-electrode electrostatic electron lenses in which center electrode is at high electrical potential. Spherical sapphire insulators are used in lieu of conventional tubular ceramic or plastic insulators in Einzel lens assembly.

Hart, R. K.↗
NASA NTRS1976

Development of a higher power fission-fragment-excited CO laser

Moderate dilution of the CO with Ar lowers the reactor excitation threshold for lasing. Fission coatings on ceramic substrates have been developed which minimize fouling of laser mirrors. A new laser apparatus was constructed which more closely resembles large electrically excited CO lasers. Measurements of the energy emerging from the foils indicate that excitation of the gas is still below optimum values. Laser action at room temperature has also been observed.

Mcarthur, D. A.↗
NASA NTRS1978

Mercury's helium exosphere after Mariner 10's third encounter

From a comparison of the Mariner 10 third encounter UV spectrometer data with intensities generated from a newly constructed model exosphere, a new value of 4.5 x 10 to the -4th power for the fraction of the solar wind He(++) flux to be intercepted and captured by Mercury's magnetosphere, if the observed He atmosphere is maintained by the solar wind, has been derived. If an internal source for He prevails, the corresponding upper bound for the global outgassing rate is estimated to be 4.5 x 10 to the 22nd power/s. These values differ from those given earlier because of the present use of a surface temperature distribution satisfying the heat equation over Mercury's entire surface which employs Mariner-10-determined mean surface thermal characteristics. The mean standoff distance of Mercury's magnetopause averaged over Mercury's orbit is also used. Agreement between the observed and calculated intensities is found to be good. Minor discrepancies on the nightside of the terminator are explicable in terms of differences between actual and computed temperatures and scale height structure changes.

Curtis, S. A.↗
NASA NTRS1976

OAST Theme Workshop. Volume 3: Working group summary. 8: Structures, dynamics (M-2). A. Statement. B. Technology needs (form 1). C. Priority assessments (form 2)

A technology program on large space structures was defined to respond to common need perceived for five of the six themes. Greatly expanded power, facilities, and communications/sensing requirements appear to demand a new structures technology for construction in space. Requirements to construct huge structural arrays with precision surfaces in space will need creative research efforts to identify practical structural elements and construction techniques. Requirements for advanced transportation structures were defined to respond to the space transportation theme. Because of the criticality of thermal structures to achieve lower cost transportation systems, renewed emphasis on technology in this area is recommended. A second technology needing renewed emphasis is the area of recovery and landing technology structures to permit full reuse of launch vehicle propulsion elements.

Source record↗
NASA NTRS1979

Update of KSC activities for the space transportation system

The paper is a status report on the facilities and planned operations at the Kennedy Space Center (KSC) that will support Space Shuttle launches. The conversion of KSC facilities to support efficient and economical checkout and launch operations in the era of the Space Shuttle is nearing completion. The driving force behind the KSC effort has been the necessity of providing adequate and indispensable facilities and support systems at minimum cost. This required the optimum utilization of existing buildings, equipment and systems, both at KSC and at Air Force property on Cape Canaveral, as well as the construction of two major new facilities and several minor ones. The entirely new structures discussed are the Shuttle Landing Facility and Orbiter Processing Facility. KSC stands ready to provide the rapid reliable economical landing-to-launch processing needed to ensure the success of this new space transportation system.

Gray, R. H.↗
NASA NTRS1981

Mars - Far-infrared spectra and thermal-emission models

Spectra of Mars from 100 to 360 kaysers were obtained during three different observation periods from NASA's Kuiper Airborne Observatory. Also, a new thermal model was constructed for the surface of Mars, and synthetic spectra were computed from the models to compare with the observations. The models include the effects of a dusty atmosphere which absorbs, scatters, and reradiates energy. The synthetic spectra show significant effects on disk-averaged brightness temperatures, as well as absorption features due to silicate dust. The spectra of Mars, which are ratios of Mars to the moon, do not fit the synthetic spectra unless the surface emissivities of Mars and the moon have different dependencies on wavelength. A possible explanation for this behavior is a difference in soil particle-size distributions between Mars and the moon, with Mars being depleted in large particles compared to the moon. Small particles are consistent with clay minerals which have been suggested elsewhere as constituents of the Martian surface.

Simpson, J. P.↗
NASA NTRS1983

A fuel-efficient cruise performance model for general aviation piston engine airplanes

A fuel-efficient cruise performance model which facilitates maximizing the specific range of General Aviation airplanes powered by spark-ignition piston engines and propellers is presented. Airplanes of fixed design only are considered. The uses and limitations of typical Pilot Operating Handbook cruise performance data, for constructing cruise performance models suitable for maximizing specific range, are first examined. These data are found to be inadequate for constructing such models. A new model of General Aviation piston-prop airplane cruise performance is then developed. This model consists of two subsystem models: the airframe-propeller-atmosphere subsystem model; and the engine-atmosphere subsystem model. The new model facilitates maximizing specific range; and by virtue of its implicity and low volume data storge requirements, appears suitable for airborne microprocessor implementation.

Parkinson, R. C. H.↗
NASA NTRS1985

Glass mirrors for space telescopes

The Hubble Space Telescope uses a primary mirror having an area of 5 sq m. The mirrors needed for two possible future telescopes, 50 sq m and 500 sq m in area, are considered. The former would be an 8-m diameter monolithic mirror of 'zero-expansion' glass, and would be diffraction-limited at optical wavelengths (0.015 arcsecond images). The 500 sq m mirror, the area proposed for the Large Deployable Reflector, would be diffraction-limited down to 30-micron wavelength (0.3 arcsecond images). Both types of mirror could be of honeycomb sandwich construction made by a new 'air inflation' method. The larger reflector would consist of ultralightweight glass panels.

Angel, J. R. P.↗
NASA NTRS1988

A relational data-knowledge base system and its potential in developing a distributed data-knowledge system

A new approach used in constructing a rational data knowledge base system is described. The relational database is well suited for distribution due to its property of allowing data fragmentation and fragmentation transparency. An example is formulated of a simple relational data knowledge base which may be generalized for use in developing a relational distributed data knowledge base system. The efficiency and ease of application of such a data knowledge base management system is briefly discussed. Also discussed are the potentials of the developed model for sharing the data knowledge base as well as the possible areas of difficulty in implementing the relational data knowledge base management system.

Rahimian, Eric N.↗
NASA NTRS1988

The vertical motion simulator

Today's flight simulators, such as NASA's multimillion dollar Vertical Motion Simulator (VMS), recreate an authentic aircraft environment, and reproduce the sensations of flight by mechanically generating true physical events. In addition to their application as a training tool for pilots, simulators have become essential in the design, construction, and testing of new aircraft. Simulators allow engineers to study an aircraft's flight performance and characteristics without the cost or risk of an actual test flight. Because of their practicality, simulators will become more and more important in the development and design of new, safer aircraft.

Hosein, Todd↗
NASA NTRS1989

A (13)C NMR analysis of the effects of electron radiation on graphite/polyetherimide composites

Initial investigations have been made into the use of high resolution nuclear magnetic resonance (NMR) for the characterization of radiation effects in graphite and Kevlar fibers, polymers, and the fiber/matrix interface in graphite/polyetherimide composites. Sample preparation techniques were refined. Essential equipment has been procured. A new NMR probe was constructed to increase the proton signal-to-noise ratio. Problem areas have been identified and plans developed to resolve them.

Ferguson, Milton W.↗
NASA NTRS1990

High speed all optical networks

An inherent problem of conventional point-to-point wide area network (WAN) architectures is that they cannot translate optical transmission bandwidth into comparable user available throughput due to the limiting electronic processing speed of the switching nodes. The first solution to wavelength division multiplexing (WDM) based WAN networks that overcomes this limitation is presented. The proposed Lightnet architecture takes into account the idiosyncrasies of WDM switching/transmission leading to an efficient and pragmatic solution. The Lightnet architecture trades the ample WDM bandwidth for a reduction in the number of processing stages and a simplification of each switching stage, leading to drastically increased effective network throughputs. The principle of the Lightnet architecture is the construction and use of virtual topology networks, embedded in the original network in the wavelength domain. For this construction Lightnets utilize the new concept of lightpaths which constitute the links of the virtual topology. Lightpaths are all-optical, multihop, paths in the network that allow data to be switched through intermediate nodes using high throughput passive optical switches. The use of the virtual topologies and the associated switching design introduce a number of new ideas, which are discussed in detail.

Chlamtac, Imrich↗
NASA NTRS1989

Computational neural learning formalisms for manipulator inverse kinematics

An efficient, adaptive neural learning paradigm for addressing the inverse kinematics of redundant manipulators is presented. The proposed methodology exploits the infinite local stability of terminal attractors - a new class of mathematical constructs which provide unique information processing capabilities to artificial neural systems. For robotic applications, synaptic elements of such networks can rapidly acquire the kinematic invariances embedded within the presented samples. Subsequently, joint-space configurations, required to follow arbitrary end-effector trajectories, can readily be computed. In a significant departure from prior neuromorphic learning algorithms, this methodology provides mechanisms for incorporating an in-training skew to handle kinematics and environmental constraints.

Gulati, Sandeep↗
NASA NTRS1990

Luminosity-velocity diagrams for Virgo Cluster spirals. I - Inner rotation curves

Optical rotation curves are presented for the innermost portions of nine spiral galaxies in the Virgo Cluster. The emission-line (H-alpha and forbidden N II) velocity data are to be used in combination with new CCD photometry to construct luminosity-velocity diagrams, in a continuing investigation of an apparent initial linear branch and its potential as a distance indicator. Compared to recent H I data, the present optical rotation curves generally show systematically steeper inner gradients. This effect is ascribed to the poorer resolution of the H I data and/or to holes in the gas distribution.

Woods, David↗
NASA NTRS1991

Algebraic grid generation for complex geometries

An efficient computer program called GRID2D/3D has been developed to generate single and composite grid systems within geometrically complex two- and three-dimensional (2D and 3D) spatial domains that can deform with time. GRID2D/3D generates single grid systems by using algebraic grid generation methods based on transfinite interpolation. The distribution of grid points within the spatial domain is controlled by stretching functions and grid lines can intersect boundaries of the spatial domain orthogonally. GRID2D/3D generates composite grid systems by patching together two or more single grid systems. The patching can be discontinuous or continuous. For 2D spatial domains the boundary curves are constructed by using either cubic or tension spline interpolation. For 3D spatial domains the boundary surfaces are constructed by using a new technique, developed in this study, referred to as 3D bidirectional Hermite interpolation.

Shih, T. I.-P.↗