Cold molecular welding study Quarterly report, 15 Sep. - 15 Dec. 1966

Cold welding evaluation techniques studied by using beryllium-copper pellets and 321 stainless steel wear plate

Inorganic solid film lubricants Patent

Preparation of inorganic solid film lubricants with long wear life and stability in aerospace environment

Space station momentum management

Gravity gradient stabilization is planned for the space station. Torques arise from air-drag since the center of pressure is not the same as the center of mass of the satellite. The magnitude of these torques varies depending upon the orientation of the solar panels. Adjustments are made through the use of CMG's (Control Moment Gyros). In time, if the CMG's saturate, torque must be bled off using thrusters; however, that is undesirable because it expends propellant and contaminates the local environment. The task of the engineer is to design the CMG's to handle the aerodynamic torques and design the configuration of the spacecraft to prevent, if possible, CMG saturation. For this application the long-term atmospheric density trends are of less importance than the rate of change of density within an orbit. In principle, CMG's could be designed for the worst case of maximum solar activity, but the penalty for overdesign is excess mass and cost. In summary, present models are inadequate for this application with the greatest need being a reliable prediction of maximum rates-of-change of density within an orbit

Design and breadboard evaluation of the SPS reference phase control system concept

The total breadboard system includes one pilot transmitter, one pilot receiver, nine phase distribution units, and two power transponders. With this complement of equipment, segments of a typical phase distribution system can be assembled to facilitate the evaluation of significant system parameters. The achievable accuracy of a large phase distribution system, the sensitivity of the system to parameter variations, and the limitations of commercially available components in such applications were determined

Examining collusion and voting biases between countries during the Eurovision song contest since 1957

The Eurovision Song Contest (ESC) is an annual event which attracts millions of viewers. It is an interesting activity to examine since the participants of the competition represent a particular country's musical performance that will be awarded a set of scores from other participating countries based upon a quality assessment of a performance. There is a question of whether the countries will vote exclusively according to the artistic merit of the song, or if the vote will be a public signal of national support for another country. Since the competition aims to bring people together, any consistent biases in the awarding of scores would defeat the purpose of the celebration of expression and this has attracted researchers to investigate the supporting evidence for biases. This paper builds upon an approach which produces a set of random samples from an unbiased distribution of score allocation, and extends the methodology to use the full set of years of the competition's life span which has seen fundamental changes to the voting schemes adopted. By building up networks from statistically significant edge sets of vote allocations during a set of years, the results display a plausible network for the origins of the culture anchors for the preferences of the awarded votes. With 60 years of data, the results support the hypothesis of regional collusion and biases arising from proximity, culture and other irrelevant factors in regards to the music which that alone is intended to affect the judgment of the contest.Comment: to be published in JASS

The radio AGN population dichotomy: Green valley Seyferts versus red sequence low-excitation AGN

Radio outflows of active galactic nuclei (AGN) are invoked in cosmological models as a key feedback mechanism in the latest phases of massive galaxy formation. Recently it has been suggested that the two major radio AGN populations -- the powerful high-excitation, and the weak low-excitation radio AGN (HERAGN and LERAGN, resp.) -- represent two earlier and later stages of massive galaxy build-up. To test this, here we make use of a local (0.04<z<0.1) sample of ~500 radio AGN with available optical spectroscopy, drawn from the FIRST, NVSS, SDSS, and 3CRR surveys. A clear dichotomy is found between the properties of low-excitation (absorption line AGN, and LINERs) and high-excitation (Seyferts) radio AGN. The hosts of the first have the highest stellar masses, reddest optical colors, and highest mass black holes but accrete inefficiently (at low rates). On the other hand, the high-excitation radio AGN have lower stellar masses, bluer optical colors (consistent with the `green valley'), and lower mass black holes that accrete efficiently (at high rates). Such properties can be explained if these two radio AGN populations represent different stages in the formation of massive galaxies, and thus are also linked to different phases of the `AGN feedback'.Comment: 5 pages, 4 figures, 1 table, to appear in ApJ

Marriage as a Rat Race: Noisy Pre-Marital Investments with Assortative Matching

We study the incentive to invest to improve marriage prospects, in a frictionless marriage market with non-transferable utility. Stochastic returns to investment eliminate the multiplicity of equilibria in models with deterministic returns, and a unique equilibrium exists under reasonable conditions. Equilibrium investment is efficient when the sexes are symmetric. However, when there is any asymmetry, including an unbalanced sex ratio, investments are generically excessive. For example, if there is an excess of boys, then there is parental over-investment in boys and under-investment in girls, and total investment will be excessive.marriage, ex ante investments, gender differences, assortative matching tournament, sex ratio