Superhumps in V348 Pup

The eclipsing novalike cataclysmic variable star V348 Pup exhibits a persistent luminosity modulation with a period 6 per cent longer than its 2.44 hour orbital-period (Porb). This has been interpreted as a `positive superhump' resulting from a slowly precessing non-axisymmetric accretion disc gravitationally interacting with the secondary. We find a clear modulation of mid-eclipse times on the superhump period, which agrees well with the predictions of a simple precessing eccentric disc model. Our modelling shows that the disc light centre is on the far side of the disc from the donor star when the superhump reaches maximum light. This phasing suggests a link between superhumps in V348 Pup and late superhumps in SU UMa systems. Modelling of the full lightcurve and maximum entropy eclipse mapping both show that the disc emission is concentrated closer to the white dwarf at superhump maximum than at superhump minimum. We detect additional signals consistent with the beat periods between the implied disc precession period and both (1/2)Porb and (1/3)Porb.Comment: 13 pages, 13 figures, accepted for publication in MNRA

Doppler Tomography of Dwarf Nova IY UMa during Quiescence

Quiescent Doppler tomography of the newly discovered deeply-eclipsing SU UMa system IY UMa reveals properties of the region where the accretion stream from the donor impacts the edge of the disc. A very strong bright spot is produced and the Keplerian disc emission in the impact region is disrupted or obscured. The differing properties of Halpha, Hbeta and He I emission will allow physical parameters of the converging flow region to be studied.Comment: 6 pages, 5 figures. To appear in Proceedings of Astro-Tomography Workshop, Brussels, July 2000, Eds. H. Boffin, D. Steeghs, Springer-Verlag Lecture Notes in Physic

Thermal control system corrosion study

During the development of an expert system for autonomous control of the Space Station Thermal Control System (TCS), the thermal performance of the Brassboard TCS began to gradually degrade. This degradation was due to filter clogging by metallic residue. A study was initiated to determine the source of the residue and the basic cause of the corrosion. The investigation focused on the TCS design, materials compatibility, Ames operating and maintenance procedures, and chemical analysis of the residue and of the anhydrous ammonia used as the principal refrigerant. It was concluded that the corrosion mechanisms involved two processes: the reaction of water alone with large, untreated aluminum parts in a high pH environment and the presence of chlorides and chloride salts. These salts will attack the aluminum oxide layer and may enable galvanic corrosion between the aluminum and the more noble stainless steel and other metallic elements present. Recommendations are made for modifications to the system design, the materials used, and the operating and maintenance procedures, which should largely prevent the recurrence of these corrosion mechanisms

A COMPARISON OF COMPOSITE MATERIAL FAILURE UNDER CYCLIC AND BLOCK AMPLITUDE LOADING

Military use of glass fiber composites (GFC) is growing due to their advantageous strength-to-weight ratio. Applications of GFC are currently limited by the incomplete understanding of the failure characteristics of composites. A universal failure criteria and predictive fatigue model have been proposed to predict composite failure. The goal of this study was to further validate and refine the predictive failure model. This study subjected notched quasi-isotropic GFC and cross-ply samples to cyclic loading at multiple percentages of their ultimate tensile strength. This testing generated S-N curves for these composites. Further block amplitude cyclic testing of the notched samples was conducted. The results of the cyclic and stepped cyclic testing were then compared to theoretical predictions from the predictive model. GFC offer a variety of benefits over traditionally used materials; a better understanding of the failure criteria will allow these benefits to be applied in more areas of ship and aircraft design.Distribution Statement A. Approved for public release: Distribution is unlimited.Lieutenant, United States Nav

Zoning--Townships--Complete Exclusion of Trailer Camps and Parks

Plaintiff challenged the validity of an amendment to the zoning ordinance of the defendant township which barred all trailer camps and parks from its industrial district. As trailer parks had previously been zoned out of the business, residential, and agricultural districts, this amendment had the effect of completely excluding them from the entire township, although approximately half of its twenty-three square miles consisted of open rural area. The parties stipulated that the plans of the plaintiff, who wanted to develop a trailer park on his premises, met all of the applicable health standards. The trial court sustained the amendment, but its decision was reversed by the appellate division. On appeal by the township to the New Jersey Supreme Court, held, reversed, two justices dissenting. As the exclusion of trailer parks was deemed necessary to enable the township to realize its full potential for extensive and rapid growth as a well-ordered community attractive to industry, the amendment to the zoning ordinance barring trailer parks from its industrial district constitutes a valid exercise of the zoning power of the township. Vickers v. Township Comm., 37 N.J. 232, 181 A.2d 129 (1962), cert. denied, 371 U.S. 233 (1963)

Constitutional Law-Relation of State and Federal Governments-Application of the Hatch Act to the Political Activity of a State Official

Plaintiff brought an action to set aside a determination of the United States Civil Service Commission that his political activities while Illinois State Director of Conservation were in violation of the Hatch Act. The district court held that such an application of the Hatch Act would infringe upon the plaintiff\u27s vested rights, and would contravene the constitutional guarantee to the state of a republican form of government. On appeal, held, reversed. Application of the Hatch Act to state employees does not deprive them of any vested rights under the United States Constitution. Palmer v. United States Civil Sero. Comm\u27n, 297 F.2d 450 (7th Cir. 1962)