6,734 research outputs found
Summary of XB-70 airplane cockpit environmental data
Thermal, acoustical, and acceleration environments of XB-70 airplane crew compartment in airworthiness test
Results from tests, with van-mounted sensor, of magnetic leader cable for aircraft guidance during roll-out and turnoff
Tests were conducted with a van mounted experimental magnetic leader cable sensor to evaluate its potential for measuring aircraft displacement and heading with respect to the leader cable during roll out and turnoff. Test results show that the system may be usable in measuring displacement but the heading measurement contains errors introduced by distortion of the magnetic field by the metal van or aircraft
High power operation of an X-band gyrotwistron
We report the first experimental verification of a gyrotwistron amplifier. The device utilized a single 9.858 GHz, TE011 cavity, a heavily attenuated drift tube, and a long tapered output waveguide section. With a 440 kV, 200-245 A, 1 μs electron beam and a sharply tapered axial magnetic field, peak powers above 21 MW were achieved with a gain near 24 dB. Performance was limited by competition from a fundamental TE11 mode. A multimode code was developed to analyze this system, and simulations were in good agreement with the experiment
AN ANALYSIS OF THE PROFILES AND MOTIVATIONS OF HABITUAL COMMODITY SPECULATORS
The focus of this study is the habitual speculator in commodity futures markets. The speculator's activity broadens a market, creates essential liquidity, and performs an irreplaceable pricing function. Working knowledge of the profiles and motivations of habitual speculators is essential to both market theorist and policy makers. Responses to a 73 question survey were collected directly from retail commodity brokers with offices in Alabama. Each questionnaire recorded information on an individual commodity client who had traded for an extended period of time. The typical trader studied is a married, white male, age 52. He is affluent and well educated. He is a self-employed business owner who can recover from financial setbacks. He is a politically right wing conservative involved in the political process. He assumes a good deal of risk in most phases of his life. He is both an aggressive investor and an active gambler. This trader does not consider preservation of his commodity capital to be a very high trading priority. As a result, he rarely uses stop loss orders. He wins more frequently than he loses (over 51% of the time) but is an overall net loser in dollar terms. In spite of recurring trading losses, he has never made any substantial change in his basic trading style. To this trader, whether he won or lost on a particular trade is more important than the size of the win or loss. Thus he consistently cuts his profits short while letting his losses run. He also worries more about missing a move in the market by being on the sidelines than about losing by being on the wrong side of a market move; i.e., being in the action is more important than the financial consequences. Participating brokers confirmed that for the majority of the speculators studied, the primary motivation for continuous trading is the recreational utility derived largely from having a market position.Marketing,
The Predictability of Commodity Trading Advisor Returns
This study investigates the performance and predictability of returns generated by advisors to Commodity Trading Funds from 1979 through 1989. Rates of return and Sharpe Ratios show evidence of predictability from one year to the next for all Commodity Trading Advisors (CTAs). Returns for the top one-third and top 5 performing CTAs show more predictability than for all CTAs
Discovery of High-Latitude CO in a HI Supershell in NGC 5775
We report the discovery of very high latitude molecular gas in the edge-on
spiral galaxy, NGC 5775. Emission from both the J=1-0 and 2-1 lines of 12CO is
detected up to 4.8 kpc away from the mid-plane of the galaxy. NGC 5775 is known
to host a number of HI supershells. The association of the molecular gas
M(H2,F2) = 3.1x10^7 solar masses reported here with one of the HI supershells
(labeled F2) is clear, which suggests that molecular gas may have survived the
process which originally formed the supershell. Alternatively, part of the gas
could have been formed in situ at high latitude from shock-compression of
pre-existing HI gas. The CO J=2-1/J=1-0 line ratio of 0.34+-40% is
significantly lower than unity, which suggests that the gas is excited
subthermally, with gas density a few times 100 cubic cm. The molecular gas is
likely in the form of cloudlets which are confined by magnetic and cosmic rays
pressure. The potential energy of the gas at high latitude is found to be
2x10^56 ergs and the total (HI + H2) kinetic energy is 9x10^53 ergs. Based on
the energetics of the supershell, we suggest that most of the energy in the
supershell is in the form of potential energy and that the supershell is on the
verge of falling and returning the gas to the disk of the galaxy.Comment: Accept by ApJL, 4 pages, 3 ps figure
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