A new dry biomedical electrode

Electronic circuitry contains new operational amplifier which incorporates monolithic super-gain transistors. Electrode does not provide voltage amplification; instead, it acts as current amplifier to make it possible to pick up electrical potentials from surface of highly resistant dry skin

An investigation of the reduction of carbon dioxide in a silent electric discharge

The reduction of CO2 to O2 and CO in a silent electric discharge was studied. It was found that current alone (in the ionized plasma induced by the silent electric discharge) was reponsible for the CO2 reduction process. Voltage and frequency were important only in so far as they induced current in the plasma. Pressure and temperature were of minimum influence in the process. The large power consumption in the process was recognized as resulting from the low power factor of the reactor vessel which electrically behaved like a capacitor. The power factor was subsequently improved by adding an inductive element to make the reactor vessel capacitance part of a resonant circuit. It was found that the CO2 reduction process was most efficient in terms of power vs reduction rate when a voltage was employed that was only slightly higher than that needed to induce the plasma

A NASTRAN/TREETOPS solution to a flexible, multi-body dynamics and controls problem on a UNIX workstation

Demands for nonlinear time history simulations of large, flexible multibody dynamic systems has created a need for efficient interfaces between finite-element modeling programs and time-history simulations. One such interface, TREEFLX, an interface between NASTRAN and TREETOPS, a nonlinear dynamics and controls time history simulation for multibody structures, is presented and demonstrated via example using the proposed Space Station Mobile Remote Manipulator System (MRMS). The ability to run all three programs (NASTRAN, TREEFLX and TREETOPS), in addition to other programs used for controller design and model reduction (such as DMATLAB and TREESEL, both described), under a UNIX Workstation environment demonstrates the flexibility engineers now have in designing, developing and testing control systems for dynamically complex systems

Uniqueness and Homogeneity of Ordered Relational Structures

There are four major results in the paper. (1) In a general ordered relational structure that is order dense, Dedekind complete, and whose dilations (automorphisms with fixed points) are Archimedean, various consequences of finite uniqueness are developed (Theorem 2.6). (2) Replacing the Archimedean assumption by the assumption that there is a homogeneous subgroup of automorphisms that is Archimedean ordered is sufficient to show that the structure can be represented numberically as a generalized unit structure in the sense that the defining real relations satisfy the usual numerical property of homogeneity (Theorem 3.4). The last two results pertain just to idempotent concatenation structures. (3) In a closed, idempotent, solvable, and Dedekind complete concatenation structure, homogeneity is equivalent to the structure satisfying an inductive property analogous to the condition for homogeneity in a positive concatenation structure (Theorem 4.3). Finally, (4) an axiomatization is given for an idempotent structure to be of scale type (2, 2), which has previously been shown to be equivalent to a dual bilinear representation. Basically two operations are defined in terms of the given one, and the conditions are that each must be right autodistributive and together they satisfy a generalized bisymmetry property. The paper ends listing several unsolved problems.Psycholog

Rational Versus Plausible Accounting Equivalences in Preference Judgments

Subjective expected utility (SEU) embodies four distinct principles of rational behavior. Although all have been called into some question empirically, the least plausible and least studied is the property that formally equivalent gambles are treated as indifferent in preference. The paper describes some results that arise when this property is sharply weakened and to some degree replaced by alternative rational and not-so-rational-assumptions. The resulting utility representations, like SEU, are weighted averages of the utilities of consequences, but with the weights dependent on more than the underlying chance event. In rank-dependent cases, which arise from a restricted assumption about formally equivalent gambles, the weights depend on the rank position of the corresponding consequence. In ank-and sign-dependent models, they depend both on the rank position of the consequence associated to the event and on whether it is a gain or a loss. The theory giving rise to the latter involves an additional primitive, namely, joint receipt of gambles, in terms of which new rational and irrational assumptions are invoked. The result generalizes prospect theory to gambles with more than a single gain and a single loss.Psycholog

Spin and energy transfer in nanocrystals without transport of charge

We describe a mechanism of spin transfer between individual quantum dots that does not require tunneling. Incident circularly-polarized photons create inter-band excitons with non-zero electron spin in the first quantum dot. When the quantum-dot pair is properly designed, this excitation can be transferred to the neighboring dot via the Coulomb interaction with either {\it conservation} or {\it flipping} of the electron spin. The second dot can radiate circularly-polarized photons at lower energy. Selection rules for spin transfer are determined by the resonant conditions and by the strong spin-orbit interaction in the valence band of nanocrystals. Coulomb-induced energy and spin transfer in pairs and chains of dots can become very efficient under resonant conditions. The electron can preserve its spin orientation even in randomly-oriented nanocrystals.Comment: 13 pages, 3 figure

Gravity-assisted trajectories for unmanned space exploration

Gravity assistance to modify heliocentric trajectories of manned space probe

Henri Temianka Correspondence; (luce)

https://digitalcommons.chapman.edu/temianka_correspondence/2332/thumbnail.jp

Thermal stress response of General Purpose Heat Source (GPHS) aeroshell material

A thermal stress test was conducted to determine the ability of the GPHS aeroshell 3 D FWPF material to maintain physical integrity when exposed to a severe heat flux such as would occur from prompt reentry of GPHS modules. The test was performed in the Giant Planetary Facility at NASA's Ames Research Center. Good agreement was obtained between the theoretical and experimental results for both temperature and strain time histories. No physical damage was observed in the test specimen. These results provide initial corroboration both of the analysis techniques and that the GPHS reentry member will survive the reentry thermal stress levels expected