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Making More-Complex Molecules Using Superthermal Atom/Molecule Collisions

Atoms adsorbed on cold surfaces react with energetic impinging atoms. A method of making more-complex molecules from simpler ones has emerged as a by-product of an experimental study in outer-space atom/ surface collision physics. The subject of the study was the formation of CO2 molecules as a result of impingement of O atoms at controlled kinetic energies upon cold surfaces onto which CO molecules had been adsorbed. In this study, the O/CO system served as a laboratory model, not only for the formation of CO2 but also for the formation of other compounds through impingement of rapidly moving atoms upon molecules adsorbed on such cold interstellar surfaces as those of dust grains or comets. By contributing to the formation of increasingly complex molecules, including organic ones, this study and related other studies may eventually contribute to understanding of the origins of life.

Posted in: Briefs, TSP

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Embedded Computing Options Meet Rugged Industrial Requirements

While industrial applications typically require high levels of reliability, availability, ruggedness, and longevity, there often is a set of unique system requirements dependent upon the specific goals of the system. For instance, an industrial automation application may call for a particular I/O interface or the ability to support custom control software.

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Thermal Spray Formation of Polymer Coatings

This innovation forms a sprayable polymer film using powdered precursor materials and an in-process heating method. This device directly applies a powdered polymer onto a substrate to form an adherent, mechanically-sound, and thickness-regulated film. The process can be used to lay down both fully dense and porous, e.g., foam, coatings. This system is field-deployable and includes power distribution, heater controls, polymer constituent material bins, flow controls, material transportation functions, and a thermal spray apparatus.

Posted in: Briefs

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Improved Gas Filling and Sealing of an HC-PCF

Compact hermetic joint is formed to seal connectorized all-fiber gas reference cell. An improved packaging approach has been devised for filling a hollow-core photonic-crystal fiber (HC-PCF) with a gas, sealing the HC-PCF to retain the gas, and providing for optical connections and, optionally, a plumbing fitting for changing or augmenting the gas filling. Gas-filled HC-PCFs can be many meters long and have been found to be attractive as relatively compact, lightweight, rugged alternatives to conventional gas-filled glass cells for use as molecular-resonance frequency references for stabilization of lasers in some optical-metrology, lidar, optical-communication, and other advanced applications. Prior approaches to gas filling and sealing of HC-PCFs have involved, variously, omission of any attempt to connectorize the PCF, connectorization inside a vacuum chamber (an awkward and expensive process), or temporary exposure of one end of an HC-PCF to the atmosphere, potentially resulting in contamination of the gas filling. Prior approaches have also involved, variously, fusion splicing of HC-PCFs with other optical fibers or other termination techniques that give rise to Fresnel reflections of about 4 percent, which results in output intensity noise.

Posted in: Briefs, TSP

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Software for Continuous Replanning During Execution

Feedback from execution of a plan is used to update the plan continuously. Continuous Activity Scheduling Planning Execution and Replanning (CASPER) is a computer program for automated planning of interdependent activities within a system subject to requirements, constraints, and limitations on resources. Now at the prototype stage of development, CASPER was conceived to enable a robotic exploratory spacecraft to perform onboard, autonomous planning and replanning of scientific observations and other functions in response to diverse unanticipated phenomena that could include unknown or changing environmental conditions, equipment failures, and errors in mathematical models used in planning. On Earth, CASPER could be adapted to use in scheduling operations of production lines and other complex systems.

Posted in: Briefs, TSP

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An Efficient Algorithm for Propagation of Temporal-Constraint Networks

The computational cost is much less than in prior algorithms. An efficient artificial-intelligence-type algorithm for the propagation of temporal constraints has been devised for incorporation into software that performs scheduling and planning of tasks in real time. This algorithm checks for temporal consistency and computes time windows of time points within temporal-constraint networks, which are often used in scheduling and planning. A C++-language computer program that implements the algorithm has been devised for incorporation into the control software of the Mission Data System of NASA’s Jet Propulsion Laboratory. The algorithm and program could also be applied to industrial planning and scheduling problems.

Posted in: Briefs, TSP

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Estimating Heterodyne-Interferometer Polarization Leakage

Correction for the nonlinearity contributed by polarization leakage can be made in real time. A method of estimating and correcting for the effect of polarization leakage on the response of a heterodyne optical interferometer has been devised. In a typical application in which a heterodyne interferometer is used as a displacement or length gauge, the effect of the polarization leakage is a nonlinearity that typically gives rise to an error of the order of 1 nm in the displacement or length. By use of the present method, it should eventually be possible, in principle, to reduce the error to the order of 10 pm or less. The technique is primarily computational and does not require any additional interferometer hardware. Moreover, the computations can be performed on almost any modern computer in real time.

Posted in: Briefs, TSP

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