A prototype DSN X/S-band feed: DSS 13 application status

A prototype X/S-band common aperture horn feed for future use at various DSN sites and the Network Consolidation Program is discussed. The final design and fabrication of the second generation feedhorn and combiner is dealt with. The results of the measurements obtained with the second generation, full scale feed configuration are presented

Elastomer coated filler and composites thereof comprising at least 60% by weight of a hydrated filler and an elastomer containing an acid substituent

The impact resistance of flame retardant composites, especially thermoplastic molding: compounds containing over 60% hydrated mineral filler such as Al(OH)3 or Mg(OH)2 as improved by coating the filler with 1 to 20% of an elastomer. The composite will fail by crazing or shearing rather than by brittle fracture. A well bonded elastomeric interphase resulted by utilizing acidic substituted resins such as ethyl-hexyl acrylate-acrylic acid copolymers which bond to and are cross-linked by the basic filler particles. Further improvement in impact resistance was provided by incorporating 1 to 10% of a resin fiber reinforcement such as polyvinyl alcohol fibers that decompose to yield at least 30% water when heated to decomposition temperature

Matthew Baillie's specimens and engravings

In 1799, Matthew Baillie, William Hunter's nephew, published his famous atlas of pathology. It was entitled A Series of Engravings Accompanied with Explanations which are Intended to Illustrate the Morbid Anatomy of Some of the Most Important Parts of the Human Body. The present study aims to match the illustrations to extant specimens in the collections of William and John Hunter, preserved at the University of Glasgow and at the Royal College of Surgeons of England respectively. Baillie's book contains 10 fasciculi, consisting of 73 plates and 206 figures. The specimens Baillie illustrated came from his own collection and those of ten others, including his uncles, William and John Hunter. The book was illustrated by William Clift and engraved by James Basire, William Skelton and James Heath. Excluding eight illustrations of intestinal worms where the provenance of the specimens is uncertain, a total of 98 specimens from William Hunter's collection were illustrated in 104 figures. Eight of the specimens were calculi impossible to identify specifically. Excluding worms and calculi, 72 of William Hunter's specimens illustrated by Baillie are extant in the Hunterian Collection at the University of Glasgow. All but one of the 20 specimens illustrated that had belonged to John Hunter were identified in the on-line catalogue of the Royal College of Surgeons of England. Baillie's own collection was destroyed when the Royal College of Surgeons of England was bombed in 1941. Baillie is credited with being the first to produce an illustrated systematic textbook of morbid anatomy and probably the first to illustrate emphysema and transposition of the great vessels. His book, however, was not comprehensive. It did not cover a number of topics such as muscles and bones and there is little coverage of the nervous system. Baillie's book, however, was an original concept as an atlas of morbid anatomy and showed his deep insight into pathology

Barriers to the utilization of synthetic fuels for transportation

The principal types of engines for transportation uses are reviewed and the specifications for conventional fuels are compared with specifications for synthetic fuels. Synfuel processes nearing the commercialization phase are reviewed. The barriers to using synfuels can be classified into four groups: technical, such as the uncertainty that a new engine design can satisfy the desired performance criteria; environmental, such as the risk that the engine emissions cannot meet the applicable environmental standards; economic, including the cost of using a synfuel relative to conventional transportation fuels; and market, involving market penetration by offering new engines, establishing new distribution systems and/or changing user expectations

Compatibility of elastomers in alternate jet fuels

The compatibility of elastomeric compositions of known resistance to aircraft fuels was tested for potential use in Jet A type fuels obtainable from alternate sources, such as coal. Since such fuels were not available at the time, synthetic alternate fuels were prepared by adding tetralin to a petroleum based Jet A type fuel to simulate coal derived fuels which are expected to contain higher amounts of aromatic and hydroaromatic hydrocarbons. The elastomeric compounds tested were based on butadiene-acrylonitrile rubber, a castable Thiokol polysulfide rubber, and a castable fluorosilicone rubber. Batches of various cross-link densities of these rubbers were made and their chemical stress relaxation behavior in fuel, air, and nitrogen, their swelling properties, and response to mechanical testing were determined

Development and evaluation of elastomeric materials for geothermal applications

A material for a casing packer for service for 24 hours in a geothermal environment was developed by synthesis of new elastomers and formulation of available materials. Formulation included use of commercial elastomer gumstocks and also crosslinking of plastic (high Tg) materials. Fibrous reinforcement of fluorocarbon rubbers was emphasized. Organic fiber reinforcement did not increase hot properties significantly. Glass fiber reinforcement gave significant increase in tensile properties. Elongation was reduced, and the glass-reinforced composition examined so far did not hold up well in the geothermal environment. Colloidal asbestos fibers were also investigated. A few experiments with polyphenyl ether gave material with low tensile and high compression set. Available high styrene SBR compositions were studied. Work to date suggests that new synthetic polymers will be required for service in geothermal environments

THE FDA AND PLAN B: The Legislative History of the Durham-Humphrey Amendments and the Consideration of Social Harms in the Rx-OTC Switch

The 1951 Durham-Humphrey Amendments limited the FDA’s power over the Rx-OTC decision by enacting an objective definition of a prescription drug that would be applied primarily by drug manufacturers. Under this regime, Congress likely intended the Rx-OTC decision to be limited to consideration of medical or scientific harms so as to insure the most limited role for the FDA, maximize the ability of the public to self-medicate, and insure consistency in different manufacturer’s Rx-OTC determinations. However, the 1962 Drug Amendments expanded the FDA’s power regarding Rx to OTC switches by requiring the FDA to balance the costs and benefits of a drug to determine whether it was in the best interest of society for the drug to be marketed OTC. Thus, social harms are appropriate considerations for the Rx-OTC decision if they are true societal costs of a drug, specifically, if they are quantifiable, generally accepted, and a reasonable probability. Applying these lessons to the proposed Rx to OTC switch of the emergency contraceptive Plan B, the FDA seems to have exceeded its authority by considering social harms—increased teen promiscuity and decreased teen condom use—that are not reasonably probable. Moreover, by failing to acknowledge that it was considering social harms the FDA threatened the transparency necessary to administrative accountability