Injector for use in high voltage isolators for liquid feed lines

An improved injector is described for use in introducing fluid substances into feed lines employed in delivering flowing bodies of liquids. The injector includes a porous plug, concentrically related to a feed line, including an internally tapered surface of a truncated conical configuration with an inlet orifice of a first diameter substantially smaller than the first diameter and an external surface circumscribed by an annular chamber containing a body of insulating gas

The design and performance estimates for the propulsion module for the booster of a TSTO vehicle

A NASA study of the propulsion systems for possible low-risk replacements for the Space Shuttle is presented. Results of preliminary studies to define the USAF two-stage-to-orbit (TSTO) concept to deliver 10,000 pounds to low polar orbit are described. The booster engine module consists of an over/under turbine bypass engines/ramjet engine design for acceleration from takeoff to the staging point of Mach 6.5 and approximately 100,000 feet altitude. Propulsion system performance and weight are presented with preliminary mission study results of vehicle size

High-temperature LM cathode ion thrusters Quarterly progress report, 5 May - 4 Aug. 1968

Design and operation of high temperature liquid mercury cathode ion thruster

An optical heterodyne densitometer

Researchers are developing an optical heterodyne densitometer with the potential to measure optical density over an unprecedented dynamic range with high accuracy and sensitivity. This device uses a Mach-Zender interferometer configuration with heterodyne detection to make direct comparisons between optical and RF attenuators. Researchers expect to attain measurements of filter transmittance down to 10 to the minus 12th power with better than 1 percent uncertainty. In addition, they intend to extend the technique to the problem of measuring low levels of light scattering from reflective and transmissive optics

High-temperature LM cathode ion thrusters Quarterly progress report, 5 Feb. - 4 May 1968

Poiseuille flow measurements for high temperature liquid metal cathode ion thruster

Advanced core technology: Key to subsonic propulsion benefits

A study was conducted to identify the potential performance benefits and key technology drivers associated with advanced cores for subsonic high bypass turbofan engines. Investigated first were the individual sensitivities of varying compressor efficiency, pressure ratio and bleed (turbine cooling); combustor pressure recovery; and turbine efficiency and inlet temperature on thermal efficiency and core specific power output. Then, engine cycle and mission performance benefits were determined for systems incorporating all potentially achievable technology advancements. The individual thermodynamic sensitivities are shown over a range of turbine temperatures (at cruise) from 2900 to 3500 R and for both constant (current technology) and optimum (maximum thermal efficiency) overall pressure ratios. It is seen that no single parameter alone will provide a large increase in core thermal efficiency, which is the thermodynamic parameter of most concern for transport propulsion. However, when all potentially achievable advancements are considered, there occurs a synergism that produces significant cycle and mission performance benefits. The nature of these benefits are presented along with the technology challenges

"Napsterizing" Pharmaceuticals: Access, Innovation, and Consumer Welfare

We analyze the effects on consumers of an extreme policy experiment -- Napsterizing' pharmaceuticals -- whereby all patent rights on branded prescription drugs are eliminated for both existing and future prescription drugs without compensation to the patent holders. The question of whether this policy maximizes consumer welfare cannot be resolved on an a priori basis due to an obvious tradeoff: While accelerating generic entry will yield substantial gains in consumer surplus associated with greater access to the current stock of pharmaceuticals, future consumers will be harmed by reducing the flow of new pharmaceuticals to the market. Our estimates of the consumer surpluses at stake are based on the stylized facts concerning how generic entry has affected prices, outputs, and market shares. We find that providing greater access to the current stock of prescription drugs yields large benefits to existing consumers. However, realizing those benefits has a substantially greater cost in terms of lost consumer benefits from reductions in the flow of new drugs. Specifically, the model yields the result that for every dollar in consumer benefit realized from providing greater access to the current stock, future consumers would be harmed at a rate of three dollars in present value terms from reduced future innovation. We obtain this result even accounting for the stylized fact that after generic entry branded drugs continue to earn significant price premia over generic products and hence recognizing that Napsterizing does not completely eliminate the incentives to innovate.