17,240 research outputs found
Vacuum gage system for radiation environment
Hot-cathode ionization gages used to measure high-vacuum pressures are subject to error when ionizing radiation is present. Because this radiation creates additional ions, a second ion gage is mounted near the pressure-measuring gage to detect and measure the radiation induced error
Estimating sensitivity of vacuum gages
Gage sensitivity for a particular gas is estimated using the known performance of the gage with a reference gas /nitrogen/ and employing several empirical rules which have usable accuracy. Relative gage sensitivities have been estimated for over 100 gases and vapors
Beating the Book: Are There Patterns in NFL Betting Lines?
Las Vegas sports books provide two even-money bets (not counting commission, or vigorish ) regarding National Football League games- the point-spread between each pair of teams and the total number of points scored by each pair of teams (the over-under ). Odds makers set the numbers ( lines ) for these two bets almost a week in advance of the games, and they may change these numbers throughout the week as new information becomes available regarding the teams or as bettors bet unequally on either side of the line. This study examines whether there are any predictable patterns in the betting lines over the course of the preceding week that bettors could exploit to improve their expected returns, including whether it would have been profitable to try for middles as the betting lines changed over the course of the week. We will also note whether during the years studied any simple betting strategy, such as betting on favorites, underdogs, home teams, or visiting teams, would have been profitable
NO sub X destruction by CO in NO sub X to NO converters of chemiluminescent NO analyzers
An instrument modification for chemiluminescent NO - NOx analyzers was developed which minimizes the NOx destruction in the NOx to NO converters of NO analyzers due to high concentrations of CO. This mechanism causes the NO analyzers to indicate incorrect NOx concentrations when the analyzers are operated in the NOx analysis mode. The modification is applicable to analyzers in which the detection chamber is evacuated
Empirical Observations on the Sensitivity of Hot Cathode Ionization Type Vacuum Gages
A study of empirical methods of predicting tile relative sensitivities of hot cathode ionization gages is presented. Using previously published gage sensitivities, several rules for predicting relative sensitivity are tested. The relative sensitivity to different gases is shown to be invariant with gage type, in the linear range of gage operation. The total ionization cross section, molecular and molar polarizability, and refractive index are demonstrated to be useful parameters for predicting relative gage sensitivity. Using data from the literature, the probable error of predictions of relative gage sensitivity based on these molecular properties is found to be about 10 percent. A comprehensive table of predicted relative sensitivities, based on empirical methods, is presented
On Deriving Space-Time From Quantum Observables and States
We prove that, under suitable assumptions, operationally motivated data
completely determine a space-time in which the quantum systems can be
interpreted as evolving. At the same time, the dynamics of the quantum system
is also determined. To minimize technical complications, this is done in the
example of three-dimensional Minkowski space.Comment: 19 pages, to appear in Communications in Mathematical Physics; minor
corrections mad
Integrated exhaust gas analysis system for aircraft turbine engine component testing
An integrated exhaust gas analysis system was designed and installed in the hot-section facility at the Lewis Research Center. The system is designed to operate either manually or automatically and also to be operated from a remote station. The system measures oxygen, water vapor, total hydrocarbons, carbon monoxide, carbon dioxide, and oxides of nitrogen. Two microprocessors control the system and the analyzers, collect data and process them into engineering units, and present the data to the facility computers and the system operator. Within the design of this system there are innovative concepts and procedures that are of general interest and application to other gas analysis tasks
Nonsteady flow-direction measurement
Nonsteady flow probe uses miniature pressure transducers mounted within probe support very close to tube inlets. Response speed depends on internal volume between tube inlet and pressure transducer location
An integrated exhaust gas analysis system with self-contained data processing and automatic calibration
An integrated gas analysis system designed to operate in automatic, semiautomatic, and manual modes from a remote control panel is described. The system measures the carbon monoxide, oxygen, water vapor, total hydrocarbons, carbon dioxide, and oxides of nitrogen. A pull through design provides increased reliability and eliminates the need for manual flow rate adjustment and pressure correction. The system contains two microprocessors to range the analyzers, calibrate the system, process the raw data to units of concentration, and provides information to the facility research computer and to the operator through terminal and the control panels. After initial setup, the system operates for several hours without significant operator attention
Teachers guide for building and operating weather satellite ground stations for high school science
A number of colleges and universities are operating APT direct readout stations. However, high school science teachers have often failed to realize the potential of meteorological satellites and their products as unique instructional tools. The ability to receive daily pictures from these satellites offers exciting opportunities for secondary school teachers and students to assemble the electronic hardware and to view real time pictures of Earth from outer space. The station and pictures can be used in the classroom to develop an approach to science teaching that could span many scientific disciplines and offer many opportunities for student research and participation in scientific processes. This can be accomplished with relatively small expenditures of funds for equipment. In most schools some of the equipment may already be available. Others can be constructed by teachers and/or students. Yet another source might be the purchase of used equipment from industry or through the government surplus channels. The information necessary for individuals unfamiliar with these systems to construct a direct readout for receiving real time APT photographs on a daily basis in the classroom is presented
- …