A new method for satellite orbit determination using an operational worldwide transponder network

The method utilizes computer programs developed for the forthcoming ATS-F/NIMBUS-F tracking and data relay experiment where the basic tracking measurements are multiple path round-trip propagation times and rates. This method of orbit computation has recently been successfully evaluated by tracking a geostationary satellite (ATS-3) using an existing VHF (150 MHz) network of automatic transponders. A master station sequentially interrogates each transponder via the ATS-3. The master site is located at Schenectady, N. Y. and four automatic transponders were located at Shannon, Reykajavik, Buenos Aires, and Seattle respectively. Data at hourly intervals were collected during a 24 hour period on April 18-19, 1973. After correcting this data for known systematic errors it was provided as input to an orbit determination program where all satellite motions during signal propagation are rigorously accounted for. The resulting estimated ATS-3 orbit yielded observational residuals on the order of 100 meters. By using more than one satellite the present scheme is further capable of accurately locating several stationary or mobile terminals as part of the overall orbital solution

Development of sputtered techniques for thrust chambers, task 1

Filler materials proposed for use in the sputter fabrication regeneratively cooled thrust chambers were evaluated. Low melting castable alloys, CERROBEND. CERROCAST, and CERROTRU, slurry applied SERMETEL 481 and flame-sprayed aluminum were investigated as filler materials. Sputter deposition from a cylindrical cathode inverted magnestron was used to apply an OFHC copper closeout layer to filled OFHC copper ribbed-wall cylindrical substrates. The sputtered closeout layer structure was evaluated with respect to filler material contamination, predeposition machining and finishing operations, and deposition parameters. The application of aluminum by flame-spraying resulted in excessiver filler porosity. Though the outgassing from this porosity was found to be detrimental to the closeout layer structure, bond strengths in excess of 10,500 psi were achieved. Removal of the aluminum from the grooves was readily accomplished by leaching in a 7.0 molar solution of sodium hydroxide at 353 K. Of the other filler materials evaluated, CERROTRU was found to be the most suitable material with respect to completely filling the ribbed-wall cylinders and vacuum system compatibility. However, bond contamination resulted in low closeout layer bond strength with the CERROTRU filler. CERROBEND, CERROCAST, and SERMETEL 481 were found to be unacceptable as filler materials

IS SOCIAL CAPITAL REALLY CAPITAL?

Social capital in the past two decades has emerged as a dominant paradigm in the various social science disciplines. However, its adoption by the different social science disciplines has led to multiple and often conflicting definitions of social capital. Some differences in the definition of social capital can be explained because scientists have included in the definition expressions of its possible uses, where it resides, and how its service capacity can be changed. This paper defends the social capital metaphor by pointing out that social capital has many important capital-like properties including service potential, durability, flexibility, substitutability, opportunities for decay (maintenance), reliability, ability to create other capital forms, and investment (disinvestment) opportunities. Social capital is compared to other forms of capital including cultural capital and human capital. Keywords: social capital, cultural capital, human capital, physical/financial capital, service potential, durability, flexibility, substitutability, decay (maintenance), reliability, investment (disinvestment)social capital, cultural capital, human capital, physical/financial capital, service potential, durability, flexibility, substitutability, decay (maintenance), reliability, investment (disinvestment), Institutional and Behavioral Economics,

Geodetic Earth Orbiting Satellite /GEOS-C/, Applications Technology Satellite /ATS-F/ tracking experiment

Design analysis of GEOS-C/ATS-F tracking experimen

SOCIAL CAPITAL AND POVERTY REDUCTION: TOWARD A MATURE PARADIGM

Introduction The purposes of this paper are: (1) to introduce the social capital paradigm; (2) to present evidence that social capital has an important role in poverty reduction; and (3) to suggest several policy prescriptions for building and using social capital to reduce poverty. The social capital paradigm includes social capital, networks, socio-emotional goods, attachment values, institutions, and power. Social capital is a person or group's sympathy for others. Social capital resides in sympathetic relationships that can be described using networks. One reason to value social capital is because it can produce economic benefits and if neglected, economic disadvantages. Another reason to value social capital is because it can be used to produce socio-emotional goods. Sometimes socio-emotional goods become embedded in objects. When this occurs, the meaning and value of the object change. The change in the value of an object produced by embedded socio-emotional goods is the object's attachment value. Individuals exchange both physical and socio-emotional goods. Institutions are the rules that order and give meaning to exchanges. Institutions with high attachment values are more likely to be observed than those whose compliance depends on economic incentives or threats. Finally, power, the ability to influence others, depends on one's resources, including one's social capital. In most personalized transactions, persons exchange both socio-emotional goods and physical goods and services. Moreover, the relative amounts of socio-emotional goods and physical goods and services exchanged will alter the levels and terms of trade when measured in physical units. Since one's ability to include socio-emotional goods in exchanges for physical goods and services depends on one's social capital, the terms and levels of exchange of physical goods and services will be influenced by the transacting party's social capital. Those with high levels of social capital will have advantages over those who lack social capital because they can exchange both socio-emotional goods and physical goods and services. Furthermore, since social capital alters the terms and levels of trade and the terms and levels of trade influence the distribution of incomes derived from trades, then social capital also has an important influence on the distribution of household income and poverty. Some evidence suggests that the distribution of social capital in networks and the distribution of household incomes are connected.Food Security and Poverty, Institutional and Behavioral Economics,

Development of sputtered techniques for thrust chambers

Techniques and materials were developed and evaluated for the fabrication and coating of advanced, long life, regeneratively cooled thrust chambers. Materials were analyzed as fillers for sputter application of OFHC copper as a closeout layer to channeled inner structures; of the materials evaluated, aluminum was found to provide the highest bond strength and to be the most desirable for chamber fabrication. The structures and properties were investigated of thick sputtered OFHC copper, 0.15 Zr-Cu, Al2O3,-Cu, and SiC-Cu. Layered structures of OFHC copper and 0.15 Zr-Cu were investigated as means of improving chamber inner wall fatigue life. The evaluation of sputtered Ti-5Al-2.5Sn, NASA IIb-11, aluminum and Al2O3-Al alloys as high strength chamber outer jackets was performed. Techniques for refurbishing degraded thrust chambers with OFHC copper and coating thrust chambers with protective ZrO2 and graded ZrO2-copper thermal barrier coatings were developed

Probing of the Kondo peak by the impurity charge measurement

We consider the real-time dynamics of the Kondo system after the local probe of the charge state of the magnetic impurity. Using the exactly solvable infinite-degeneracy Anderson model we find explicitly the evolution of the impurity charge after the measurement.Comment: 4 pages, 1 eps figure, revte

Hamiltonian systems with symmetry, coadjoint orbits and plasma physics

The symplectic and Poisson structures on reduced phase spaces are reviewed, including the symplectic structure on coadjoint orbits of a Lie group and the Lie-Poisson structure on the dual of a Lie algebra. These results are applied to plasma physics. We show in three steps how the Maxwell-Vlasov equations for a collisionless plasma can be written in Hamiltonian form relative to a certain Poisson bracket. First, the Poisson-Vlasov equations are shown to be in Hamiltonian form relative to the Lie-Poisson bracket on the dual of the (nite dimensional) Lie algebra of innitesimal canonical transformations. Then we write Maxwell's equations in Hamiltonian form using the canonical symplectic structure on the phase space of the electromagnetic elds, regarded as a gauge theory. In the last step we couple these two systems via the reduction procedure for interacting systems. We also show that two other standard models in plasma physics, ideal MHD and two- uid electrodynamics, can be written in Hamiltonian form using similar group theoretic techniques

Position and Mode Dependent Optical Detection Back-Action in Cantilever Beam Resonators

Optical detection back-action in cantilever resonant or static detection presents a challenge when striving for state-of-the-art performance. The origin and possible routes for minimizing optical back-action have received little attention in literature. Here, we investigate the position and mode dependent optical back-action on cantilever beam resonators. A high power heating laser (100 {\mu}W) is scanned across a silicon nitride cantilever while its effect on the first three resonance modes is detected via a low-power readout laser (1 {\mu}W) positioned at the cantilever tip. We find that the measured effect of back-action is not only dependent on position but also the shape of the resonance mode. Relevant silicon nitride material parameters are extracted by fitting the temperature-dependent frequency response of the first three modes to finite element (FE) simulations. In a second round of simulations, using the extracted parameters, we successfully fit the FEM results with the measured mode and position dependent back-action. Finally, different routes for minimizing the effect of this optical detection back-action are described, allowing further improvements of cantilever-based sensing in general

Device for in-situ cleaving of hard crystals

Cleaving crystals in a vacuum chamber is a simple method for obtaining atomically flat and clean surfaces for materials that have a preferential cleaving plane. Most in-situ cleavers use parallel cutting edges that are applied from two sides on the sample. We found in ambient experiments that diagonal cutting pliers, where the cleavage force is introduced in a single point instead of a line work very well also for hard materials. Here, we incorporate the diagonal cutting plier principle in a design compatible with ultra-high vacuum requirements. We show optical microscopy (mm scale) and atomic force microscopy (atomic scale) images of NiO(001) surfaces cleaved with this device.Comment: 7 pages, 3 figures Submitted to Review of Scientific Instruments (2005