Fluid valve assembly

A valve assembly is reported for controlling the flow of fluids between the inlet and outlet of a fluid valve. The valve assembly contains a barrier element which is porous for providing fluid communication between the valve inlet and outlet. The valve assembly also includes a sealing element that is movable relative to the barrier element between a first position, in which fluid flow through the porous portion of the barrier element is blocked preventing fluid communication between the valve inlet and outlet, and a second position, in which the porous portion is unblocked, permitting fluid communication between the valve inlet and outlet

Coping with Phantom Risks in the Courts

Dr. Huber describes phantom risks as those tending to hover indefinitely, never to crystallize. He argues that legal procedures should optimally lead\u27 to closure and eliminate unwarranted fears

Measurement of partial pressures in vacuum technology and vacuum physics

It is pointed out that the measurement of gaseous pressures of less than 0.0001 torr is based on the ionization of gas atoms and molecules due to collisions with electrons. The particle density is determined in place of the pressure. The ionization cross sections for molecules of various gases are discussed. It is found that the true pressure in a vacuum system cannot be determined with certainty if it is unknown which gas is present. Effects of partial pressure determination on the condition of the vacuum system are discussed together with ion sources, systems of separation, and ion detection

Inflatable tether Patent

Space expandable tether device for use as passageway between two docked spacecraf

Hand-held self-maneuvering unit Patent

Hand-held maneuvering unit for propulsion and attitude control of astronauts in zero or reduced gravity environmen

Combined potential of future long-baseline and reactor experiments

We investigate the determination of neutrino oscillation parameters by experiments within the next ten years. The potential of conventional beam experiments (MINOS, ICARUS, OPERA), superbeam experiments (T2K, NOvA), and reactor experiments (D-CHOOZ) to improve the precision on the ``atmospheric'' parameters $\Delta m^2_{31}$, $\theta_{23}$, as well as the sensitivity to $\theta_{13}$ are discussed. Further, we comment on the possibility to determine the leptonic CP-phase and the neutrino mass hierarchy if $\theta_{13}$ turns out to be large.Comment: 4 pages, 4 figures, Talk given by T.S. at the NOW2004 workshop, Conca Specchiulla (Otranto, Italy), 11--17 Sept. 200

Hyperbolic Discounting of Public Goods

This article examines revealed rates of time preference for public goods, using environmental quality as the case study. A nationally representative panel-based sample of 2,914 respondents considered a series of 5 conjoint policy choices, yielding 14,570 decisions. Both the conditional fixed effect logit estimates of the random utility model and mixed logit estimates implied that the rate of time preference is very high for immediate improvements and drops off substantially thereafter, which is inconsistent with exponential discounting but consistent with hyperbolic discounting. The implied marginal rate of time preference declines and then rises. Estimates of the quasi-hyperbolic discounting parameter range from 0.48 to 0.61. People who are older are especially likely to have a high disutility from delays in improving water quality.

Study of Lyndon B. Johnson Space Center utility systems

The results of an engineering study of potential energy saving utility system modifications for the NASA Lyndon B. Johnson Space Center are presented. The objective of the study was to define and analyze utility options that would provide facility energy savings in addition to the approximately 25 percent already achieved through an energy loads reduction program. A systems engineering approach was used to determine total system energy and cost savings resulting from each of the ten major options investigated. The results reported include detailed cost analyses and cost comparisons of various options. Cost are projected to the year 2000. Also included are a brief description of a mathematical model used for the analysis and the rationale used for a site survey to select buildings suitable for analysis