2,932 research outputs found
Microprocessor-based multichannel flutter monitor using dynamic strain gage signals
Two microprocessor-based multichannel monitors for monitoring strain gage signals during aerodynamic instability (flutter) testing in production type turbojet engines were described. One system monitors strain gage signals in the time domain and gives an output indication whenever the signal amplitude of any gage exceeds a pre-set alarm or abort level for that particular gage. The second system monitors the strain gage signals in the frequency domain and therefore is able to use both the amplitude and frequency information. Thus, an alarm signal is given whenever the spectral content of the strain gage signal exceeds, at any point, its corresponding amplitude vs. frequency limit profiles. Each system design is described with details on design trade-offs, hardware, software, and operating experience
The UV absorption spectrum of C60 (buckminsterfullerene): A narrow band at 3860 Ã…
The absorption spectrum of the special C60 cluster buckminsterfullerene has been studied in a supersonic beam by laser depletion of the cold van der Waals complexes of C60 with benzene and methylene chloride. Both complexes were found to display a single, isolated absorption band in the near ultraviolet superimposed on a structureless absorption continuum. For the methylene chloride complex this feature is centered at 3860 Å, and is roughly 50 cm−1 wide. In the benzene van der Waals cluster, the corresponding feature is located at 3863 Å, and has a similar width. This spectrum is tentatively assigned to the 0–0 band of the lowest 1T1u<--1Ag (LUMO+1<--HOMO) transition of a truncated icosahedral carbon shell structure, broadened by coupling to the underlying quasicontinuum of ground state vibrational levels
SuperWASP observations of pulsating Am stars
We have studied over 1600 Am stars at a photometric precision of 1 mmag with SuperWASP photometric data. Contrary to previous belief, we find that around 200 Am stars are pulsating δ Sct and γ Dor stars, with low amplitudes that have been missed in previous, less extensive studies. While the amplitudes are generally low, the presence of pulsation in Am stars places a strong constraint on atmospheric convection, and may require the pulsation to be laminar. While some pulsating Am stars have been previously found to be δ Sct stars, the vast majority of Am stars known to pulsate are presented in this paper. They will form the basis of future statistical studies of pulsation in the presence of atomic diffusion
Synthesis of the Beryllium 3131A Spectral Region
The Beryllium spectral region of the Sun, Procyon and 4 stars in the open
cluster NGC6633 up to Teff = 7500K have been synthesised using ATLAS9 model
atmospheres and the MOOG spectral synthesis program.
The line list used for these syntheses has been modified from the ATLAS9 line
list to improve the quality of the fits in light of the improved opacities in
the new version of the MOOG code.
Significant changes have been made to the Mn I line at ATLAS9 wavelength
3131.037A and an OH line has been added at 3131.358A. In addition there are a
number of minor changes to gf-values throughout the synthesised region thus
improving the fit for the spectra across the temperature range considerably.Comment: 4 pages, 3 figures. To appear in the proceedings of the Workshop
"ATLAS 12 and related codes", Trieste, July 11-15, 200
The Habitable Zone Gallery
The Habitable Zone Gallery (www.hzgallery.org) is a new service to the
exoplanet community which provides Habitable Zone (HZ) information for each of
the exoplanetary systems with known planetary orbital parameters. The service
includes a sortable table with information on the percentage of orbital phase
spent within the HZ, planetary effective temperatures, and other basic
planetary properties. In addition to the table, we also plot the period and
eccentricity of the planets with respect to their time spent in the HZ. The
service includes a gallery of known systems which plot the orbits and the
location of the HZ with respect to those orbits. Also provided are animations
which aid in orbit visualization and provide the changing effective temperature
for those planets in eccentric orbits. Here we describe the science motivation,
the under-lying calculations, and the structure of the web site.Comment: 6 pages, 3 figures, accepted for publication in PAS
Workmen\u27s Compensation - Proceedings to Secure Compensation - Allowance of Attorney\u27s Fees to Claimants Unsuccessful on Appeal
Employee claimed total permanent disability as a result of an industrial accident, but was awarded compensation for only a twenty percent permanent disability. Claimant was denied certiorari by the Florida District Court of Appeals. However, claimant\u27s request for an allowance of reasonable attorney\u27s fees for the unsuccessful appeal was granted. Claimant\u27s employer was then granted certiorari on its contention that the Florida workmen\u27s compensation statute and a past Florida Supreme Court decision had established that attorney\u27s fees would be allowed only when the claimant\u27s appeal was successful. On certiorari, held, award of attorney\u27s fees affirmed. The statute allows an appellate court a sound judicial discretion as to whether attorney\u27s fees should be allowed to the attorneys for the claimant-employee, even though he is unsuccessful on appeal. However, the court should impose upon an unsuccessful claimant-appellant a heavy burden to show the justification for the allowance of additional attorney\u27s fees under such circumstances. Wick Roofing Co. v. Curtis, (Fla. 1959) 110 S. (2d) 385
Corporations - Amendment of Articles of Incorporation - Power of Majority to Require Holders of Redeemable Preferred Stock to Accept Bonds Instead of Money in Redemption
Plaintiffs owned 6 percent cumulative convertible prior preferred stock in defendant corporation. The stock had a stated value of 115 per share plus accumulated dividends. By vote of more than two-thirds of the outstanding shares of each class of stock issued, defendant\u27s articles of incorporation were amended to authorize its board of directors to redeem the prior stock at $120 per share, payable in the company\u27s 5 percent 30-year debentures. Interest on the debentures was to be cumulative, paid out of earnings, and subordinated to the other indebtedness of the company. Redemption was to be compulsory. Plaintiffs sought a declaratory judgment that the amendment was invalid. On appeal from a judgment for defendant, held, reversed. The amendment in question was beyond the powers of amendment given by the statute to the corporation. Bowman v. Armour & Co., (Ill. 1959) 160 N.E. (2d) 753
Creditors\u27 Rights - Physicians\u27 Liens on Patients\u27 Tort Claim
A recent Illinois statute creates a lien in favor of licensed physicians for their reasonable charges for treating persons injured by the negligent or wrongful act of another. The lien attaches to all claims or causes of action of the injured person against the person causing the injury, whether settled by litigation or by settlement. The maximum amount recoverable under the lien is one-third of the sum paid or due to the injured party, and the lien is expressly made to survive his death. The physician must serve notice of his assertion of the lien on both the injured party and the person liable for the injury. On ten-days\u27 written notice, any party to the action may have access to the physician\u27s records concerning his treatment of the injured party. The lien is made inferior to attorneys\u27 liens, does not apply at all in workmen\u27s compensation cases, and may be enforced in the courts of the state. Ill. Rev. Stat. (1959) c. 82, §§101.1-101.6
Spray automated balancing of rotors: Methods and materials
The work described consists of two parts. In the first part, a survey is performed to assess the state of the art in rotor balancing technology as it applies to Army gas turbine engines and associated power transmission hardware. The second part evaluates thermal spray processes for balancing weight addition in an automated balancing procedure. The industry survey reveals that: (1) computerized balancing equipment is valuable to reduce errors, improve balance quality, and provide documentation; (2) slow-speed balancing is used exclusively, with no forseeable need for production high-speed balancing; (3) automated procedures are desired; and (4) thermal spray balancing is viewed with cautious optimism whereas laser balancing is viewed with concern for flight propulsion hardware. The FARE method (Fuel/Air Repetitive Explosion) was selected for experimental evaluation of bond strength and fatigue strength. Material combinations tested were tungsten carbide on stainless steel (17-4), Inconel 718 on Inconel 718, and Triballoy 800 on Inconel 718. Bond strengths were entirely adequate for use in balancing. Material combinations have been identified for use in hot and cold sections of an engine, with fatigue strengths equivalent to those for hand-ground materials
The mass and radius of the M-dwarf in the short period eclipsing binary RR Caeli
We present new photometry and spectroscopy of the eclipsing white dwarf -
M-dwarf binary star RR Cae. We use timings of the primary eclipse from
white-light photo-electric photometry to derive a new ephemeris for the
eclipses. We find no evidence for any period change greater than Pdot/P ~ 5E-12
over a timescale of 10 years. We have measured the effective temperature of the
white dwarf, T_WD, from an analysis of two high resolution spectra of RR Cae
and find T_WD = (7540 +- 175)K. We estimate a spectral type of M4 for the
companion from the same spectra. We have combined new spectroscopic orbits for
the white dwarf and M-dwarf with an analysis of the primary eclipse and cooling
models for helium white dwarfs to measure the mass and radius of the M-dwarf.
The mass of the M-dwarf is (0.182 - 0.183) +- 0.013 Msun and the radius is
(0.203 - 0.215) +- 0.013 Rsun, where the ranges quoted for these values reflect
the range of white dwarf models used. In contrast to previous studies, which
lacked a spectroscopic orbit for the white dwarf, we find that the mass and
radius of the M-dwarf are normal for an M4 dwarf. The mass of the white dwarf
is (0.440 +-0.022) Msun. With these revised masses and radii we find that RR
Cae will become a cataclysmic variable star when the orbital period is reduced
from its current value of 7.3 hours to 121 minutes by magnetic braking in 9-20
Gyr. We note that there is night-to-night variability of a few seconds in the
timing of primary eclipse caused by changes to the shape of the primary
eclipse. We speculate as to the possible causes of this phenomenon. (Abridged)Comment: Accepted for publication in MNRAS. The paper contains 10 figures and
3 table
- …