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An accumulation of high precision astrometric data in conjunction with high-precision monitoring of the Earth's orientation, motivates “Galactic Astronomy”. As regards local kinematics, all of the three components of both the vorticity and the shear of stars can be completely determined, in addition to the velocity ellipsoid. We can now be released from the constraint of the “axisymmetric” galaxy. The determination of the proper motion of the LMC will be crucial to understanding the global structure and dynamics of the Galaxy with the dark halo and MACHO's motions.
The meridian circle installed at the Tokyo Astronomical Observatory in 1982/83 is equipped with a photoelectric Double Slit Micrometer which is one of the basic prerequisites for fully automatic observation. A slit plate is located in the image field of the telescope. It oscillates parallel to right ascension while being guided at the mean traveling speed of the star.
The paper describes the procedure by which the moment of the star passage through the instrument's meridian and declination is determined. Furthermore, the autocollimation devices are described which are an essential prerequisite for the determination and periodical checking of the instrumental errors.
Also, the measuring devices for the passage of the sun and the moon are dealt with briefly.
In meridian observations, the main error sources of the declination observation reside in determination of the atmospheric refraction, the flexure of the telescope and the division errors of the graduated circle. In order to obtain higher accuracy in the declination observation, besides a full automation device, the photoelectric meridian circle at Tokyo Astronomical Observatory (Tokyo PMC) is equipped with photoelectric devices for circle reading and a zenith mirror in addition to the conventional mercury horizon. We report here on a preliminary determination of the horizontal and vertical flexures, and of the division errors of the glass circle.
Definitions of Instantaneous Instrumental Coordinates and Local Horizontal Coordinates of the photoelectric meridian circle of Tokyo Astronomical Observatory are given, and a method to determine the positions of stars by using a scanning double slits micrometer are presented. It is found that stars up to 12.2 mag are observable by making a composite photon intensity. Discussions on the application of observations of faint objects by meridian circles are presented.
This study evaluated the longitudinal and long-term effects of radiotherapy on swallowing function after tongue reconstruction.
The study comprised 16 patients who had: undergone glossectomy and tongue reconstruction with free flap transfer, received adjuvant radiotherapy, and survived without recurrence for at least 1 year. Swallowing function, as indicated by tolerance of oral intake, was evaluated before radiotherapy, at radiotherapy completion, and at 6 and 12 months after radiotherapy completion.
Before radiotherapy, all patients could tolerate oral intake. At radiotherapy completion, only three patients could consume all nutrition orally. However, swallowing function improved over time, and by 12 months after radiotherapy completion it had returned nearly to that before radiotherapy.
Acute dysphagia due to radiotherapy after tongue reconstruction is severe, but can improve gradually. Multidisciplinary support of patients during percutaneous endoscopic gastrostomy dependence is important to improve long-term functional outcomes.
Gas Technology Institute (GTI), together with its partners University of California at Merced (UC Merced) and MicroLink Devices Inc. (MicroLink) are developing a full spectrum solar energy collection system to deliver variable electricity and on-demand heat. The technology uses secondary optics in a solar receiver to achieve high efficiency at high temperature, collects heat in particles for low fire danger, stores heat in particles instead of molten salt for low cost, and uses double junction (2J) photovoltaic (PV) cells with backside infrared (IR) reflectors on the secondary optical element to raise exergy efficiency. The overall goal is to deliver enhancement to established trough technology while exceeding the heliostat power tower molten salt temperature limit. The use of inert particles for heat transfer may make parabolic troughs safer near population centers and may be valuable for industrial facilities.
According to the recommendations of the Paris IAU Secretariat, the present triennial commission report is intended to put special emphasis on outstanding achievements around the main objectives of the commission rather than on abstracting all the literatures relevant to the commission. The highlights of the commission during the triennium under review have been the establishment of the conventional stellar reference frame FK5, an intensive effort in extension of the stellar reference frame to a celestial network of higher star densities and fainter magnitudes, and the launch of the astrometric satellite HIPPARCOS, as are described in this report.
Several authors have contributed to this report: L. Blitz (Section V), W.B. Burton (Sections IIIB and IVB), J. Einasto (Section VII), B. Fuchs (Sections VIC and VID), W. Hermsen (Section VIF), G. Lynga (Sections IIIA and IVA), M. Mayor (Section II), M. Miyamoto (Sections VIB and VIE) and R. Wielen (Sections I, VIA, and editing). The layout of this report follows previous practice. The galactic center is included in Sections IV and V. The references are, as far as possible, coded by their numbers (VV.CCC.NNN) in the bibliography “Astronomy and Astrophysics Abstracts” (AAA). VV identifies the volume of AAA, while CCC.NNN gives the subject category and the serial number within that volume.
The president thanks those members contributing material to this report. The volume of the material necessitated some editing, but no substantive omissions occurred. Whenever available, AAA numbers are used in lieu of complete titles of publications to help conserve space.
IAU Symposium No. 109 Astrometric Techniques, was held in Gainesville, Florida in January 1984. Although the Proceedings of that meeting are not now available (January 1935), ccmnission members and other interested parties are urged to secure access to that voline when it appears since so many facets of the commission’s work are addressed therein.
The projects LIGHT and MIRA are the space-borne and ground-based optical/Infrared-interferometer projects of the National Astronomical Observatory of Japan. The contents of each project are gradually developing, and the descriptions given below are the preliminary ones studied at the present time.
LIGHT (Light Interferometer satellite for the studies of Galactic Halo Tracers) is a scanning astrometric satellite for stellar and galactic astronomy planned to be launched between 2007 and 2010 by a M-V launcher of ISAS, Japan. Two sets of Fizeau-type 40cm-pupil interferometers with 1 m baseline are the basic structure of the satellite optics. The multi-color (U, B, V, R, I, and K) CCD arrays are planned to be used in the focal plane of the interferometer, optimized for detecting the precise locations of fringe patterns. LIGHT is expected to observe the parallaxes and proper motions of nearly a hundred million stars up to 18th visual (15thK-band) magnitude with the precision better than 0.1 milli-arcsecond (about 50 microarcsecond in V-band and 90 micro-arcsecond in K-band) in parallaxes and better than 0.1 milli-arcsecond per year in proper motions, as well as the precise photometric characteristics of the observed stars. Almost all of the giant and supergiant stars belonging to the disk and halo components of our Galaxy within 10 to 15 kpc from the sun will be observed by LIGHT to study the most fundamental structure and evolution of the Galaxy. LIGHT will become a precursor of a more sophisticated future astrometric interferometer satellite like GAIA (Lindegren and Perryman, 1996).
Automated photoelectric meridian circles are able nowadays to have the full set of graduation errors of the decimation circle determined within a few days. Thus, the modern meridian circles can be monitored, and the annual and secular changes of the graduations can be easily detected to provide the graduation corrections at any date. In order to remove systematic declination errors in the form Δδα from absolute catalogs, these continuous changes should be taken into account.
We have analyzed proper motions of about 30000 K-M giants chosen from the astrometrie catalogue ACRS Part 1 (Corbin and Urban 1991). To avoid localized velocity fields, these K-M giants are chosen from the heliocentric distance interval 0.5 - 1.0 kpc. Starting from the initial trial of the luni-solar precessional correction Δρ ~ —0”.3/cy, we have found that the motion of stars are well expressed in terms of the Oort constants for the K-M giants. After confirming that the K-M giants are in a steady-state, we have applied the velocity-field model of the plane-parallel galactic rotation with non-zero Oort constants. Then, we have found a rational set of the corrections to the FK5 system: Δρ = -0”.27 ± 0”.03/cy and Δe + Δλ = —0”.12 ± 0”.03/cy, as is shown in Table 1 (Miyamoto and Sóma 1993). In consequence, the FK5 system is still rotating.
A balloon-borne X-ray instrument with the modulation collimator was designed and constructed to study the structure of solar X-ray flares. The angular resolution was approximately one arc minute. The instrument was used on an occasion of X-ray flare on Sept. 27, 1970.
A circular arm with elliptical cross-section is used as a model of the spiral arm. It is demonstrated magnetohydrodynamically that interstellar gas may flow in a helical path along the axis of the arm and interstellar helical magnetic lines of force can spiral around it. It is pointed out that though the rolling motions of gas do not always indicate the existence of the helical magnetic field, the latter cannot be in a stationary state without the former. Some observational supports to the present model are given.
Cosmic X-rays were observed with three sets of proportional counters covering the energy range between 0.15 and 20 keV. The detector born on a spinning rocket scanned a celestial region in which the galactic latitude bII changed from 30° to −55° across the galactic plane in the Cygnus-Cassiopeia region. The spectrum of Cyg XR-2 thus obtained is represented by a thermal bremsstrahlung of temperature 3.4 keV modified by the interstellar absorption for the hydrogen column density of 3 × 1021 cm−2. The diffuse component showed an interstellar absorption effect, which was however found much weaker than one would expect if the diffuse component were due entirely to be of extragalactic origin. The spectrum obtained in the highest latitude region is represented approximately by a power law E−1.8 but shows a possible trough at about 1 keV.
We performed a couple of balloon experiments to measure the size and the location of Cyg-X-1 using the techniques of the modulation collimator . The angular periods of the modulation collimator were 26′ and 10′ for the respective flights corresponding to the approximate angular resolutions of the size determination and location, 3′ and 1′ respectively. Preliminary results of the experiment with 3′ resolution are reported here.
The present determination of the absolute magnitude .Mv(RR) of RR Lyrae stars is twofold, relying upon Hipparcos proper motions and trigonometric parallaxes separately. First, applying the statistical parallax method to the proper motions, we find < Mv(RR)>= 0.69 ± 0.10 for 99 halo RR Lyraes with <[Fe/H]> = -1.58. Second, applying the Lutz-Kelker correction to the RR Lyrae HIP95497 with the most accurately measured parallax, we obtain Mv(RR) = 0.57-0.74 at [Fe/H]=-1.6. Furthermore, allowing full use of low accuracy and negative parallaxes as well for 125 RR Lyraes with - 2.49≤[Fe/H]≤0.07, the maximum likelihood estimation yields the relation, Mv(RR)= (0.59±0.37)+(0.20±0.63)([Fe/H]+1.60), which formally agrees with the recent preferred relation. The same estimation yields again My (RR) = 0.65 ± 0.33 for the 99 halo RR Lyraes. Although the formal errors in the latter two estimates are rather large, all of the four results suggest the fainter absolute magnitude, My(RR)=0.6-0.7 at [Fe/H]=-1.6. The present results still provide the lower limit on the age of the universe which is inconsistent with a fiat, matter-dominated universe and current estimates of the Hubble constant.
A case of salvage supracricoid laryngectomy with cricohyoidoepiglottopexy after failed radiation therapy and vertical partial laryngectomy had successful oncological and functional outcomes. This is the first reported application of salvage supracricoid laryngectomy with cricohyoidoepiglottopexy after the failure of two major treatments.
A 65-year-old man was referred for salvage supracricoid laryngectomy with cricohyoidoepiglottopexy. The right recurrent hemilarynx was successfully resected. After pexis, the right lobe of the thyroid gland was repositioned to overlap and reinforce the pexis gap and fill the devoid portion of the strap muscular closure. Multiple scattered foci (recurrent tumour–node–metastasis stage T2) were identified around the arytenoid cartilage and beneath the musculocutaneous flap. Four years after supracricoid laryngectomy with cricohyoidoepiglottopexy, the patient's recovery was following a favourable course and he had satisfactory laryngeal function.
Appropriate case selection and proficient surgical skills were essential for a successful outcome. Head and neck surgeons should not be afraid to adopt functional preservation open surgical procedures in well-selected and well-motivated patients. A requirement for more challenging surgical procedures and meticulous rehabilitation processes should not exclude appropriate treatments from a surgeon's repertoire.