bluuebunny/crossref_metadata_2025 huggingface dataset:
University of Rome Carbon-14 Dates XII
Authors: Alessio M , Bella F , Improta S , Belluomini G , Calderoni G , Cortesi C , Turi B
Published: July 2016

This list includes age measurements carried out from January 1972 to December 1973 with previously described CO2-proportional counters (Alessio et al, 1970). All archaeologic and geologic samples but one come from Italian territory.
University of Tokyo Radiocarbon Measurements V
Authors: Kobayashi Hiromi , Hirose Taeko , Sugino Miyoi , Watanabe Naotune
Published: July 2016

Most of the 14C measurements reported here were made between August 1970 and August 1972. Chemical treatment of samples and counting technique remain as described previously (R, 1968, v 10, p 144–148; 1971, v 13, p 97–102). We have added Houtermans-Oeschger type multi-anode anticoincidence gas proportional counter, manufactured by Tokyo Atomic, Japan. The central counter tube, which has several small holes, 5mm diam, is made of aluminized polyethylene foil, 0.06mm thick, with 72mm inside diam and 300mm sensitive length. The external counter tube is made of stainless steel 4mm thick, with 93mm inside diam and 350mm length. The anode wires of both counters are also made of stainless steel 0.05mm diam. The counters are surrounded by a paraffin shield 50mm thick and encased in a 250mm shield of steel on all sides. Acetylene is used as the counting gas at 753.3mm Hg (22 ± 1°C). Counting rates of background and 95% activity of NBS oxalic acid standard were 1.25 ± 0.02cpm and 14.39 ± 0.12cpm, respectively.
Birmingham University Radiocarbon Dates IX
Authors: Shotton F W , Williams R E G , Johnson A S
Published: July 2016

The following list of dates contains the majority of measurements made during 1974,ie, since our last list (R, 1974, v 16, p 285–303).
Radiocarbon Dating Blood Residues on Prehistoric Stone Tools
Authors: Nelson D E , Loy T H , Vogel J S , Southon J R
Published: July 2016

We report here the first radiocarbon dating of blood residues on prehistoric stone tools. The residues found on two stone artifacts were subjected to various exploratory biochemical techniques to identify the species from which they were derived and to separate a suitable sample for dating by accelerator mass spectrometry. Although these techniques need much further development and detailed testing, the ages obtained in this first study were consistent with other data, indicating that the concept is viable. For the first time, the time of use of stone tools has been found directly, rather than by stratigraphic or other archaeologic inferential techniques.
Radiocarbon Fluctuations During the Third Millennium BC
Authors: Vogel J C , Fuls Annemarie , Visser Ebbie , Becker Bernd
Published: July 2016

Precision14C analyses have been performed on samples comprising 1 to 4 annual rings from the south-central European dendrochronologic sequence of sub-fossil oak wood covering the period 1930 to 3100 bc. Apart from a major deviation in the 29th century bc, the14C fluctuations have amplitudes of ca 10‰ and a possible periodicity of 90 years. A14C peak at 2190 bc has a rise- and decay-time of <20 years indicating rather abrupt changes in the production rate of14C. The14C calibration curve derived from these data can be used for precise dating of the Early Bronze Age in the Near East.
High-Precision Radiocarbon Dating of Bristlecone Pine from 6554 to 5350 BC
Authors: Linick Timothy W , Long Austin , Damon Paul E , Ferguson C Wesley
Published: July 2016

New results of radiocarbon dating of ca 100 decadal bristlecone pine samples from 6554 BC to 6084 BC and from 5820 to 5350 BC are presented. Using 3 new 2.5L counters filled to ca 3atm with carbon dioxide, high-precision dating has been performed by this laboratory for more than two years. Demonstration of the precision and accuracy of these counters is presented using ±2‰ measurements from the Spörer minimum period. For the older samples, ±3‰ measurements were made using ca 12-day counting times. Results are presented both as C age bpvsdendro-year BC, particularly for calibration purposes, and as Δ14Cvstime.
Overview of the Workshop on Secular Variations in Production Rates of Cosmogenic Nuclides on Earth
Authors: Gosse John C. , Reedy Robert C. , Harrington Charles D. , Poths Jane
Published: July 2016

Measurements of cosmogenic nuclides made in situ in the Earth's surface are being used to help resolve a wide range of geologic and chronologic questions. Cosmogenic nuclides (3He, 10Be, 14C, 21Ne, 26Al 36C1 are presently used) can reveal rock exposure history information leading to estimates of timing of surface forming events, rates and styles of erosion, and timing and durations of episodes of burial. Depending on the problems being tackled, a significant source of error (±10–25%) for any cosmogenic nuclide method is the present uncertainty in the spatial and temporal variability of the rates of production of these in-situ nuclides.
A Review of Current Approaches in the Pretreatment of Bone for Radiocarbon Dating by AMS
Authors: Hedges R. E. M. , Van Klinken G. J.
Published: July 2016

Although the reliability of 14C dates of bone has increased greatly since AMS methods permitted better pretreatment on smaller samples, most old, badly contaminated or severely weathered bone still give serious problems. Several groups have recently proposed improvements to sample purification methods, often supported by a number of 14C measurements. We present here an overview of these improvements. The issue is complicated by the following:

1.

Different problems are presented depending on age, preservation and degree of contamination of bone.

2.

Methods may or may not be developed with routine application in mind.

3.

Determining the conditions for which any method can be regarded as reliable is not at all straightforward.
Reduction of CO2-to-Graphite Conversion Time of Organic Materials for14C AMS
Authors: Thomsen Mette S. , Gulliksen Steinar
Published: July 2016

Graphite is the most common type of target for14C accelerator mass spectrometry (AMS). It is readily produced by catalytic reduction of CO2, but the presence of a small amount of impurities (e.g.,sulfur compounds) may retard the reaction. We have tested some techniques to find a method that reduces the impurity content of CO2produced by combustion of organic material. We found that using water during combustion reduces the average time for graphite conversion of CO2from organic matter from >3 h toca.2 h. This is the time for graphite production from CO2obtained by acid hydrolysis of calcite. Measurements of known-age and background samples show that this combustion method neither changes the isotopic ratios nor introduces any additional background.
Gamma Flux in 14C Laboratories
Authors: Theodórsson Páll , Kaihola Lauri , Loosli H. H. , Rodríguez José M.
Published: July 2016

An informal collaborative group of radiocarbon dating laboratories, the Low-Level Club, has been established to measure the gamma radiation flux and to test the efficiency of the anticoincidence counting system in laboratories with a NaI detector unit. The detector will record gamma radiation from cosmogenic nuclides, muons and secondary γ radiation formed in the passive shield by charged cosmic-ray particles. We present here the first phase of this work.
Half-Life Determination of41Ca and Some Other Radioisotopes
Authors: Kutschera Walter , Ahmad Irshad , Paul Michael
Published: July 2016

We have performed a new determination of the half-life of41Ca by measuring the specific activity of an enriched Ca material with known41Ca abundance. We measured the activityviathe 3.3-keV X-rays emitted in the electron capture decay of41Ca, and the41Ca abundance was measured by low-energy mass spectrometry. The result, t1/2= (1.01 ± 0.10) × 105yr, agrees with the recent ‘geological’ half-life of Kleinet al.,(1991), t1/2= (1.03 ± 0.07) × 105yr, and with the corrected value of Mabuchiet al.(1974), t1/2= (1.13 ± 0.12) × 105yr. We recommend the weighted mean of these three measurements, t1/2= (1.04 ± 0.05) × 105yr, as the most probable half-life of41Ca. We also discuss the situation of the radioisotopes,32Si,44Ti,79Se and126Sn, whose half-lives, though still uncertain, are potentially interesting for future AMS studies and other applications.
Accelerator Mass Spectrometry at the Lund Pelletron Accelerator
Authors: Skog Göran , Hellborg Ragnar , Erlandsson Bengt
Published: July 2016

Three years ago, funds were raised to equip the 3 MV Pelletron accelerator at the Department of Physics, Lund University for accelerator mass spectroscopy (AMS). We have modified the accelerator for mass spectroscopy by relocating focusing devices on both the low- and high-energy side of the accelerator and installing a Wien velocity filter and detectors for measuring the particle energy (E) and energy loss (ΔE). We have been working exclusively with 14C during the initial period. About 40 samples of elemental carbon have been produced, using Fe or Co as catalyst, during the last two years. The 12C− current from these samples is about 3–5 μA using an ANIS sputtering source. We are now planning 14C analyses in the fields of archaeology, Quaternary geology and radioecology.
The Use of Natural 14C and 13C in Soils for Studies on Global Climate Change
Authors: Becker-Heidmann Peter , Scharpenseel Hans-Wilhelm
Published: July 2016

Some examples are given to show that the depth distribution curves of natural 14C and 13C of thin-layer sampled soil profiles can be used for inferring changes in soil organic matter and climate changes. By using a simple exchange model, we can determine whether decomposition products are fixed by clay or transported downward toward the groundwater table. We can also estimate the amount of the Greenhouse gases, CO2 and CH4, produced by the decomposition of the organic matter in terrestrial and paddy soils and emitted from the soil. A change from C3 to C4 plants, which might occur during a predicted temperature rise in some areas, thereby influencing the carbon balance, can be clearly detected by the δ13C depth profiles. A change in organic matter input can also be calculated under certain circumstances.
Accurate Dating of Organic Deposits by AMS 14C Measurement of Macrofossils
Authors: Törnqvist Torbjörn E. , de Jong Arie F. M. , Oosterbaan Wilma A. , Van Der Borg Klaas
Published: July 2016

We made a comparative study of AMS 14C ages of organic deposits (minerotrophic peats and gyttjas) and macrofossils in order to evaluate the magnitude of a number of sources of error that may be present in bulk sediment samples. The consistency of 14C ages found for coexisting macrofossils suggests that they are unlikely to record disturbances. Some of our gyttja samples yielded an age 0.2–0.6 ka 14C years too old due to hardwater effect. We also found an aging effect in several bulk samples with a high admixture of siliciclastic material; this is attributed to fluvial input of reworked, older organic debris. Rejuvenation of bulk material as a result of root contamination occurs mainly in samples overlain by slowly accumulated deposits, and particularly in samples affected by (sub)recent roots.
Dissolved Organic and Inorganic 14C Concentrations and Ages for Coastal Plain Aquifers in Southern Maryland
Authors: Purdy C. B. , Burr G. S. , Rubin Meyer , Helz G. R. , Mignerey A. C.
Published: July 2016

The Aquia (Paleocene) and Magothy (Late Cretaceous) Formations of the Atlantic Coastal Plain represent two well-characterized (hydrodynamically and geochemically) aquifers in southern Maryland. 14C measurements of the dissolved organic (DOC) and inorganic carbon (DIC) of Aquia and Magothy groundwaters have been made using accelerator mass spectrometry (AMS). Both DI14C and DO14C concentrations in the initial flow path are unexpectedly low. As the water progresses farther from the recharge area, the DI14C percent modern carbon (pMC) is consistently lower than the DO14C pMC; this difference stays constant for all samples. The 14C-derived ages for an Aquia water sample downgradient at Site 4 are 17 ka and 12 ka for DI14C and DO14C, respectively. Radiocarbon ages have been compared to ages determined by two other independent dating methods: computer-simulated hydrodynamic modeling and age estimates based on changes in Cl−, 18O and 2H distributions, which are interpreted to be influenced by sea level and climate.
δ13C Variations in C3 Plants Over the Past 50,000 Years
Authors: Leavitt S. W. , Danzer S. R.
Published: July 2016

We examined three sets of data to determine if there are consistent changes in δ13C of C3 plants through time, under the hypothesis that environmental changes from glacial to postglacial may have caused such isotopic changes over the last 50 ka. The records of δ13C change in all types of plant data from Radiocarbon and from the University of Arizona Radiocarbon Laboratory archives both reveal significant decline of 0.8–1.0‰ in δ13C from pre- to post-10 ka BP averages. The δ13C of wood data alone from Radiocarbon shows a larger significant decline of 3.0‰, and twigs, leaves and Juniperus categories from the Arizona data individually show declines of 0.4–1.44‰. Peat and charcoal from both data sets show no significant mean δ13C differences. A highly constrained set of wood samples from the Great Lakes region spanning the last 12 ka show isotopic changes of ca. 3‰, but most of that variation apparently does not reflect global environmental changes.
Isotopes’ Radiocarbon Measurements VII
Authors: Buckley James D. , Willis Eric H.
Published: July 2016

The following list presents dates on a portion of the samples measured at ISOTOPES during 1967 and 1968 and measurements made previously for which either complete sample data has been recently received, or, in some cases, deferred due to the editorial load in preparing the definitive list.
National Physical Laboratory Radiocarbon Measurements VI
Authors: Callow W. J. , Hassall Geraldine I.
Published: July 2016

The following list comprises measurements made since those reported in NPL V.

No changes have been made in measurement technique or in the method of calculating results described in NPL III.
A Batch Preparation Method for Graphite Targets With Low Background for AMS 14C Measurements
Authors: Kitagawa Hiroyuki , Masuzawa Toshiyuki , Makamura Toshio , Matsumoto Eiji
Published: July 2016

We have developed a method of graphitization from CO2 samples for accurate 14C measurements by accelerator mass spectrometry. Our batch method, using a sealed Vycor tube, reduces the risk of contamination during graphitization and makes it possible to prepare many samples in a short time (typically 20 samples per day).
Dilemma of Dating on Lacustrine Deposits in an Hyperarid Inland Basin of NW China
Authors: Zhang H C , Ming Q Z , Lei G L , Zhang W X , Fan H F , Chang F Q , Wünnemann B , Hartmann K
Published: July 2016

Conventional and accelerator mass spectrometry (AMS) radiocarbon, TL, OSL, and IRSL dating results on samples from the cores D100 and I70 from Ejina Basin, one of the most important inland basins in arid-hyperarid NW China, show that it is difficult to determine the ages of sediments at different depths. AMS ages of core D100 samples demonstrate that the sediments at depths from 10 to 90 m were formed between 14 to 30 kyr BP. The inverted ages from both the D100 and I70 cores imply that there was a strong reworking of the sediments during and after deposition processes. The inverted ages also indicate drastic fluctuations of groundwater bearing soluble organic matters, which might be related to neotectonic activities and climate changes during the period. Consequently, it is impossible to establish an accurate and reliable chronology for the cores based only on these dates. All AMS ages, if they are reliable and acceptable, indicate a high deposition rate (5∼8 mm/yr), and since all TL, OSL, and IRSL ages are much older than those given by AMS, it makes these methods questionable for determining the ages of lacustrine-fluvial-alluvial deposits.
Masonic Theatre Pieces in London 1730–1780
Authors: Pedicord Harry William
Published: July 2016

The Age of Reason brought with it a new faith in the future of humanity which evolved from abstract ideas into a tremendous social power. Nowhere is this more evident than in the increasing influence of Freemasonry in England throughout the eighteenth century. Almost fifty years ago Bernard Fäy gave an eloquent tribute to this phenomenon: “… It [the new faith] became a social force and a concrete fact through the agency of Freemasonry which at once accepted it and advocated it; the great historical importance of modern Freemasonry results from this attitude that it took then and to which it has since consistently adhered.…”
The Possibilities of Theatrical Montage (Successive and Simultaneous)
Authors: Hořinek Zdeněk
Published: July 2016

The aesthetic concept of montage finds its origins in film and film theory. Montage, as understood by Sergei Eisenstein, is not only a mechanical linking at random, a “sticking together” of pictures from scenes and shots. The basis of montage is dramatic and dialectical; among the elements of the montage chain there are contradictory relationships, and from these new meanings develop what the separate elements do not contain. “Any two pieces, put side by side, are inevitably linked together and form a new idea, which arises from this comparison as a new quality.” The inception of new meanings through a mere connection of parts arises from the perception of a montage of parts as one unit, even though the connection was only arbitrary.
Galactic continuum source counts
Authors: Wilson T. L.
Published: July 2016

The CSIRO 11 cm continuum survey of the galactic plane from lII = 280° to 37° has recently been finished. I have used this survey to compare the number of sources in various 5° intervals north and south of the galactic center. The NRAO-CSIRO-MIT H 109α line survey (Wilson et al., 1970) found 39 sources lying between 330° and 340°, while the NRAO-MIT (Reifenstein et al., 1970) survey found only 14 between 20° and 30°. If the galaxy were symmetric, one would expect roughly equal numbers. One suspects a selection effect is present, and a rough check is very worthwhile. The CSIRO survey is particularly valuable since it is the highest resolution survey covering large portions of the galaxy on both sides of the center.
Reflection nebulae and spiral structure
Authors: Racine R. , Van Den Bergh S.
Published: July 2016

It is shown that stars embedded in reflection nebulosity may be used as spiral-arm tracers.
Photometric investigation of the association Car OB 2
Authors: Seggewiss W.
Published: July 2016

A photometric investigation of the association Car OB 2 was carried out with a photoelectric standard sequence observed with the ESO photometric telescope and plates taken with the ADH telescope of Boyden Observatory. The distance of Car OB 2 is 2.04 kpc, the color excess EB–V is 0m.38. The main sequence of this ‘OB’ association reaches at least to late A-type stars. The luminosity function was determined and compared with the luminosity functions of very young open clusters observed by Walker (1957). The distance of a group of 13 early-type stars in the area of Car OB 2 (‘group c’) was found to be 2.5 kpc, the reddening 0m.68. The relation of Car OB 2 and group c to the structure of the Carina arm is regarded.
Grape-4: A Teraflops Machine for N-Body Simulations
Authors: Taiji Makoto , Makino Junichiro , Fukushige Toshiyuki , Ebisuzaki Toshikazu , Sugimoto Daiichiro
Published: July 2016

We have developed a massively parallel special-purpose computer system for N-body simulations, GRAPE-4 (GRAvity-PipE 4). The GRAPE-4 system is designed for high-accuracy simulations of dense stellar systems. The GRAPE-4 calculates gravitational forces, their derivatives in time and potential energies. It has a hardware for prediction of positions and velocities, which is used for the individual timestep scheme. Using multi-chip module technology, we integrated 1692 chips of 640 megaflops performance. The peak speed of GRAPE-4 is 1.08 teraflops.
High Resolution Studies of Compact Binaries in Globular Clusters With HST and ROSAT
Authors: Grindlay Jonathan E.
Published: July 2016

The studies of compact binaries containing an accreting white dwarf or neutron star in the dense cores of globular clusters have made considerable progress in the past few years as a result of the high resolution images obtained with HST and ROSAT. It is now clear that cluster cores contain a significant population of these systems which must constrain the similarly large populations of millisecond pulsars as well as dynamical histories of clusters. The population of dim x-ray sources appears to be dominated by cataclysmic variables (CVs) formed by tidal capture and not exchange collisions. Our recent HST/FOS spectra of the first CVs in a cluster core, summarized here in more detail, suggest that cluster cores may contain a significant population of magnetic CVs. The required magnetic WDs may arise in spun-up cores of blue stragglers.
Deep IV-N and Yellow-Red Spectral Surveys for Carbon Stars
Authors: Kurtanidze O. M. , Nikolashvili M. G.
Published: July 2016

We present the results of the First and Second Abastumani Objective Prism Spectral Surveys along with other surveys for carbon stars carried out in recent years.
Dust Formation in Stellar Photospheres
Authors: Tsuji Takashi
Published: July 2016

We examine whether dust forms in the photospheres of carbon-rich stars by referring to the case of red and brown dwarfs for which some observational clues on dust formation are now known. Dust may form in the photospheres of dwarf carbon stars and produce significant effects on both their structure and spectra. In carbon-rich asymptotic giant branch stars, dust probably forms in the photosphere, if not in the circumstellar envelope, and radiation pressure on dust is sufficient to expel the matter directly from the photosphere. This fact may play some role in mass-loss from cool luminous stars in general, including non-pulsating stars for which no successful mechanism of mass-loss was known.
Observational results on diffuse cosmic X-rays: (Invited discourse)
Authors: Oda Minoru
Published: July 2016

The present status of observations of the diffuse cosmic X-rays is discussed. The energy spectrum in the energy range 1–100 keV has been well established. The flux around 0.25 keV appears to be rather high. The basis of the classical argument that the integration of normal galaxies in the universe is not sufficient to explain the diffuse X-ray flux is re-examined. Recent observations around 0.25 keV are discussed and results are compiled.
Some Characteristics of Interstellar Gas in the Galaxy
Authors: Weaver Harold F.
Published: July 2016

The task assigned for this review is to discuss structural features of the Galaxy as they may involve or relate to gas dynamics. Since a topic of such great breadth would permit discussion of essentially any aspect of the Galaxy, we shall narrow the view and direct attention primarily towards the larger-scale features of the system. In particular, effort will be made to place emphasis on those areas of the subject in which problems of interpretation exist and in which new theoretical models are needed.
QSQs and Radio Galaxies - their Spectra and Time Variations at Radio Frequencies
Authors: Harris Beverley J.
Published: July 2016

Accurate relative spectra for 300 radio sources from the Parkes catalogue have been measured and a statistical study made of their relation to class of optical identification and to other radio properties. Individual spectra and their time variations have also been investigated.

The results support the contention that radio sources for which no identification appears on the Palomar Sky Survey prints may be galaxies more luminous at radio frequencies than those which are identified. From a study of QSOs, radio galaxies and these blank field objects, it appears (a) that with increasing radio luminosity compact components are more often found, their presence being indicated by synchrotron self-absorption at low and high frequencies, by flat, variable spectra at high frequencies, and by interplanetary scintillations; and (b) that where no compact component contributes to the spectrum at high frequencies, many spectra steepen with increasing frequency, an effect which may be more marked for the more radio luminous objects.

Detailed analyses of the time variations in the compact components of 22 variable sources are generally consistent with the adiabatically expanding, uniform sphere model of Shklovsky, Kellermann, van der Laan and others. The model was modified to include relativistic expansion according to the formulae given by Rees and Simon. The results suggest that these components have evolved within months or years, have linear dimension of 0.1 to 100 pc and magnetic fields of 1 to 10−4 G. Some spectra at frequencies above 5000 MHz suggest non-adiabatic expansion which may be the result of continued injection of energy into an expanding region.
The Radial Velocities of Galaxies Near NGC 7331
Authors: Lynds C. R.
Published: July 2016

Radial velocity determinations for galaxies in the vicinity of NGC 7331, including the members of ‘Stephan's Quintet’, show clearly a superposition of at least two distinct physical systems. One includes NGC 7331, NGC 7320 (a Quintet member), and NGC 7343, while the other - seven or eight times more distant - contains the four remaining ‘Quintet’ constituents and six of the seven optical ‘companions’ of NGC 7331.
Secular Perturbations on Periodic Comets
Authors: Giacaglia G. E. O.
Published: July 2016

In this work we propose an approach to the calculation of secular perturbations on a comet, valid for any eccentricity (less than unity) and any inclination (not zero). The effect of several planets is discussed, but we suppose that there are no significant close approaches to any planet.
A Numerical Analysis of the Motion of Periodic Comet Brooks 2
Authors: Stumpff P.
Published: July 2016

Various sets of osculating elements of P/Brooks 2, derived by Dubyago, are introduced into an N-body integration programme and run from 1686 to 1976. Attempts are made to find a system of elements which links the apparitions before and after the close approach to Jupiter in 1922. The propagation of differential perturbations, and also nongravitational effects, is examined.
On the Problem of the Origin of Comets
Authors: Witkowski J. M.
Published: July 2016

The various hypotheses on the origin of comets are surveyed, with particular reference to the phenomenon of comet-streaming, as revealed by statistical analysis of the directions of the perihelia of cometary orbits. The difficulties of reconciling comet-streaming with any of the hypotheses of cometary origin is pointed out. It is shown that in the case of the interstellar hypothesis these difficulties may be overcome by supposing that the velocities of incoming comets are decreased through the accretion of material from an Oort cloud of solar-system comets. An estimate is made of the total number of interstellar comets in the Galaxy.
Stellar Activity of the Solar Type Observational Aspects
Authors: Godoli G.
Published: July 2016

By the expression ‘stellar activity of the solar type’ we mean the manifestations of stellar activity determined by a mechanism of the same kind as that producing the solar activity.
Molecular depletions in cloud cores
Authors: Mundy Lee G. , McMullin Joseph P.
Published: July 2016

The condensation of gas-phase molecules onto grain surfaces in cold molecular clouds is widely expected, and the presence of the resultant icy mantles well established, but quantitative study of the gas-phase depletions has not proved easy. This paper reviews the methods for determining depletions and the associated problems. Further observations are critical to testing our expectations for depletions and for the chemical evolution of forming stellar systems.
The PAH Hypothesis
Authors: D'Hendecourt L. , Dartois E.
Published: July 2016

Polycyclic Aromatic Hydrocarbons (PAHs) are undoubtedly present in large amounts in many different astronomical objects as well as in the diffuse interstellar medium. They are detected through their infrared vibrational transitions in the mid-infared but are expected to be observable in other regions of the spectrum such as the UV, the visible and the far-infrared. PAHs are suggested to be the most abundant free organic molecules in the interstellar environment. In the laboratory, investigations have been undertaken to provide the tools for the interpretation of astronomical observations. For example, the recent detection of the overtone of the well-known 3.28 μm band around 1.67 μm has led to the determination of a relatively large minimum average size of about 60 atoms. In the far-infrared, above 15 up to 100 μm, expected transitions from laboratory measurements are scattered all over this region, making the detection of these lines difficult. In the diffuse medium, a complex aromatic network is expected on interstellar grains and its similarity with carbon extracts from primitive meteorites is suggestive of a link between interstellar matter and primitive Solar System bodies, in particular comets.
A search for interstellar gas-phase CO2
Authors: Van Dishoeck E.F. , Helmich F.P.
Published: July 2016

CO2 is one of the simplest carbon- and oxygen-containing molecules, for which little is known in interstellar space, because of its high abundance in the Earth's atmosphere. Only indirect searches of the chemically related HOCO+ ion have been possible from the ground (Thaddeus et al. 1981; Minh et al. 1988, 1991). The ISO Short Wavelength Spectrometer (SWS) (de Graauw et al. 1996a) opens up the possibility to search for the infraredactive asymmetric stretch and bending modes of gas-phase CO2 around 4.3 and 15.0 μm toward bright infrared sources.
Flare Stars in Star Clusters and Associations
Authors: Ambartsumian V. A. , Mirzoyan L. V.
Published: July 2016

The study of stellar evolution can be undertaken either from a purely theoretical point of view or from a more observational approach. The present standpoint is the second one. It starts from the concepts of stellar evolution in associations and open clusters and from stellar flare activity. Statistical considerations show that flare activity is a regular stage in the evolution of stars through which all the dwarf stars go.
A Preliminary Study of the Classical Cepheid P-L Relation in the R, I Photometric System
Authors: Fernie J. D.
Published: July 2016

It is pointed out that observational work on Cepheids in the R, I photometric system offers a number of advantages: the stars are generally brighter at these wavelengths and so can be more easily and accurately observed; effects of binary companions, which are usually earlier type stars, are minimized; reddening is less, can be more easily determined, and is less liable to differing extinction laws than in the UBV system; line-blanketing problems are smaller; the range in (R — I)0 is probably less than in (B — V)0, and the importance of the colour term in the P-L-C relation thus reduced.

Available R, I data for classical Cepheids are gathered from the literature, and the P-L, P-C, and P-L-C relations investigated. It is found that the preliminary relations

represent the data to within ± 0.13 mag. in 〈MR〉 and ± 0.02 mag. in 〈R–I〉o.

There is some indication that the intrinsic colours of EV Set, U Sgr, and S Nor are bluer than hitherto believed, conceivably due to circumstellar reddening.
The Relationship of the Oe to the Be Stars
Authors: Frost Stewart A. , Conti Peter S.
Published: July 2016

Oe stars are earlier type analogues of the better known Be class. These stars have relatively narrow emission in the hydrogen lines and sometimes in the helium lines, which often appears to be double. In several Oe stars, the emission is intermittent. Other properties of the class include relatively broad absorption lines and luminosities near the main sequence. Line profiles in three representative Oe stars are presented and discussed. The similarity of the spectra of Oe and Be stars suggests that the formation mechanism for the emitting region, whatever it is, must extend to the mid O-type stars, at least.
The Motions of Uranus' Satellites: Theory and Application
Authors: Greenberg Richard
Published: July 2016

As spacecraft and sophisticated ground-based observations measure physical properties of many planets and satellites, dynamical theory and astrometry remain a principal source of such knowledge of the Uranian system. Study of the motions of Uranus' satellites thus has broad application to planetary studies as well as to celestial mechanics. Moreover, the structure and dynamics of the system provide important cosmogonical constraints; any theory of solar system origin and evolution must account for the formation within it of analogous systems of regular satellites.
Winds in hot, subluminous stars
Authors: Heap Sara R.
Published: July 2016

Recent observations with the International Ultraviolet Explorer (IUE) satellite show that two very different types of hot stars have stellar winds: not only do the young, massive OB stars (the subjects of our discussion in this symposium, so far) undergo high-velocity mass-loss, but so also do hot evolved, solar mass stars, among them the central star of planetary nebulae. In this talk, I would like to show ultraviolet spectra of two central stars, the nuclei of NGC 6826 and Abell 78, and to describe how the characteristics of these spectra may be used to derive information concerning winds in these stars and in hot stars in general.
Radio and infrared emission by O-type and related stars
Authors: Barlow M. J.
Published: July 2016

In addition to O-type stars, this review will discuss the radio and infrared properties of B supergiants and Wolf-Rayet stars, since it is generally accepted that these objects represent later stages in the evolution of O stars. The radio properties of X-ray binaries which exhibit non-thermal emission will not be discussed. Hjellming (1977) gives an excellent review of the radio properties of close binaries, including X-ray binaries.
The O-type spectroscopic binary system HD 93206
Authors: Morrison Nancy D. , Conti Peter S.
Published: July 2016

The star HD 93206 (=QZ Carinae) is a double-lined (Conti et al. 1977), eclipsing (Moffat and Seggewiss 1972) binary with a period of 6 d. Walborn (1973) classified it 09.7Ib:(n). Since the star is probably a member of the cluster Collander 228 (which is near η Carinae), its distance can be assumed to be 2600 pc. In principle, one can determine the masses of the components of HD 93206 from observations of the radial velocities and the light curve, and a spectroscopic orbit is the object of this investigation. A mass determination for an evolved star such as this one is especially important for checking recently computed evolutionary tracks with mass loss for massive stars (de Loore et al. 1977, Chiosi et al. 1978, Dearborn et al. 1978).
Introduction to the session
Authors: Heiles Carl
Published: July 2016

Five years ago, at the previous IAU Symposium (No. 60) on the galaxy, most of us pictured the interstellar medium (ISM) as a mainly quiescent medium which evolved by orderly processes–the “steady state” ISM. Radhakrishnan reviewed the “intercloud medium” which was warm (some few thousand degrees), rarefied (some few tenths cm−3), uniformly - distributed, partly ionized, and responsible for the smoothly-distributed pulsar dispersion measures and Faraday rotations. Heiles reviewed the “clouds,” which had densities of tens cm−3, temperatures of tens K, and nonspherical shapes. These two components were in approximate pressure equilibrium; Grewing, in his review of heating mechanisms, emphasized pervasive, nonvarying processes.
Large supernova remnants as common features of the disk
Authors: Weaver Harold
Published: July 2016

The distribution of the column density of HI over the sky shows strongly organized features of large angular extent. In particular, there is (1) a conspicuous set of arching concentric filaments extending more than 80° on either side of ℓ = 330°, and (2) a prominent extended region of low column density above ℓ ∼ +40° and centered on ℓ ∼ 130°. The changes is column density in the b-direction in this region of low NH is almost step-like at ℓ ∼ +40°.
Molecules in the inner few kpc of the galaxy
Authors: Liszt H. S. , Burton W. B.
Published: July 2016

Emission and absorption spectra of several molecules have been used to trace the kinematic patterns of molecular material in the inner Galaxy. For a variety of reasons, the great majority of effort in this area has focussed on the region 357 ≳ ℓ ≳ 3° very near the plane b = 0°. Extending the observational coverage of the molecular distribution away from this plane and over a wider longitude range is a tedious process only now beginning and severely hampered by relatively small beamwidths and long integration times. Our knowledge of the arrangement of molecular material in the inner few kpc of the Galaxy is primitive and quite incomplete compared to that of the atomic gas sampled at λ21 cm.
Afterthoughts from a theoretical point of view
Authors: Trimble Virginia
Published: July 2016

APOLOGIA: The edifice we call science is built of bricks contributed by many, many workers, laid according to a design too large to be comprehended by any one reviewer. My apologies, therefore, to all those whose bricks I have, through ignorance, prejudice, or lack of space, put in the wrong place, attributed to someone else, or ignored completely. Names cited below are generally those of the speakers who mentioned particular points. Proper references to who did what can thus be found in their papers and discussion remarks.
The Physics of Radio Sources and Cosmology
Authors: Scheuer P. A. G.
Published: July 2016

There are two important questions in which the physics of radio sources impinges upon cosmology. The first is whether the large apparent expansion velocities of certain compact sources can be explained satisfactorily within the hypothesis that their red-shifts are due to the Hubble expansion. The second is the whole broad question of the evolution of the radio source population with epoch. I do not have a new and convincing answer to the first, and the second is pretty nebulous, since we do not even understand radio sources at the present epoch very well. So I shall not present a general survey: instead, I shall use my allotted time to discuss a smaller question to which one can now give a fairly definite answer.
Mixing Between the Core and the Envelope in Stars with Deep Convection Zones
Authors: Sugimoto Daiichiro , Nomoto Ken-Ichi
Published: July 2016

The extensive surface convection zone of a red giant star becomes deeper and deeper, as the star evolves. In some cases it reaches the bottom of the hydrogen-rich envelope and even penetrates into the stellar core. From the standpoint of entropy distribution in the star, the structure of the convective envelope and the mechanism of its penetration into the core are summarized. Possibilities of the penetration are discussed for stars of masses in the range of 1–60 M⊙ over their entire lifetimes of evolution. Effects of uncertainty in the mixing length theory of convection, neutrino loss and thermal instability of helium-burning shell are studied also. When the convection penetrates into the core, material of the core is brought up to the stellar surface and the star will be a peculiar star. It is concluded that there are possibilities to interpret the origin of peculiar stars with luminosities fainter than 7 × 104L⊙, but that the more luminous ones do not originate from the penetration of surface convection.
Stars of T Tauri and UV Ceti Types and the Phenomenon of Continuous Emission
Authors: Ambartsumian V. A.
Published: July 2016

Our knowledge concerning stars of the T Tauri and UV Ceti types has been considerably enlarged during recent years, owing to the accumulation of a large number of facts. As a result, we may now make certain suggestions regarding the causes of the non-stability of these stars, based on observational data. Such an approach to the solution of the problem is altogether different from that applied heretofore in attempts to develop a theory of certain types of variable stars. The method of construction of models has usually been applied in the past. We do not exclude, of course, the possibility of solving a problem on the basis of some theoretical model. However, the physical phenomena observed in the T Tauri and UV Ceti stars are so unusual that it is first of all necessary to define the nature of these phenomena and their mutual interrelation. Only then will detailed mathematical construction of a definite model be possible.
2. Oblique-scattering method for measuring individual radiants and meteor velocities
Authors: Andrianov N. S. , Kurganov R. A. , Nasirov A. M. , Sidorov V. V.
Published: July 2016

In recent years, in addition to back-scatter radio methods of meteor studies, the oblique-scattering technique, earlier utilized for purposes of meteor radio-communication, has been more widely used. This has produced results, not only because of the availability of large quantities of experimental data obtained on numerous radio-communication lines, but also due to certain advantages of this ‘forward-scatter’ technique.
9. The influence of exposure duration and trail orientation on photographic meteor spectra
Authors: Halliday I.
Published: July 2016

The effects on photographic meteor spectra produced by an occulting shutter and by the geometric orientation of the trail with respect to the camera are considered. A Perseid meteor photographed with both an occulted and unocculted spectrograph shows that large changes in the relative intensity of spectral lines can be caused by a shutter. The strong wake spectrum of this meteor is studied and a classification of multiplets according to duration and wake intensity is presented. It is emphazised that a strong wake is produced by a coasting gas rather than by particles or droplets. The gas may coast an appreciable distance during the radiating lifetime of some multiplets.

The spectrum of a bright Quadrantid meteor is used to show that long-duration multiplets are strongly enhanced when the orientation of the trail lengthens the effective path length of the wake column, i.e., the meteor is observed near its radiant. The abundance of calcium appears to be above average in this meteor.

Multiple photographs of the λ5577 line of neutral oxygen have been secured showing a decay time in excess of 1·5 sec. The decay is more rapid at lower heights and it appears that the mechanism of excitation to the metastable level operates for an interval of about 0·1 sec.

As more accurate photometry of meteor spectra is achieved it will be essential to give careful attention to all of these effects.
Radio Emission
Authors: Davies J.G.
Published: July 2016

I understand that my task is to summarize the present state of radio observation of planetary nebulae, and to give us radio observers our marching orders for the next few years. Where, then, do we stand at the end of this Symposium? Well over 100 planetary nebulae have been looked at by one or more groups at one or more frequencies, and nearly that number have been detected. Most nebulae which have been observed at several frequencies show optically thin spectra, about eight to a wavelength of 40 cm, and three to 70 cm. The fluxes of these nebulae agree well with the values predicted from the observed Hβ radiation, after correction for interstellar extinction. Some are clearly optically thick at long wavelengths, but none have been shown to remain so at the shortest wavelengths. NGC 6853 becomes optically thin near 75 cm, and NGC 6857 may become thin near 5 cm. Eight further nebulae become thin at intermediate wavelengths.
Oscillatory modes of energy transport in solar magnetic regions
Authors: Danielson R. E. , Savage B. D.
Published: July 2016

It appears that it is necessary to look for oscillatory (i.e. overstable) instabilities as the cause of energy transport in sunspots. Making use of recent calculations on the hydromagnetic stability of thermally unstable layers with open boundary conditions, it is found that oscillatory modes can occur in the interior of sunspots. Some possible consequences of these oscillatory modes are discussed.
Some comments about correlations between magnetic field and velocity, magnetic field and line intensity in the undisturbed photosphere
Authors: Vassilyeva G. Y. , Tchandaev A. K.
Published: July 2016

Test cross-correlation functions between the magnetic field recordings and the sight-line velocity recordings with East and West relative lag for two regions near the centre of the disk have been computed. We have also found the deviations of the absolute value of the magnetic-field strength |H| from the mean absolute value of magnetic-field strength |H̄| for the whole region. The same procedure for the velocity field has been made. The cross-correlation functions for these deviations have also been computed (Figure 1).
Observation des jets et concentrations de la couronne au-dessus des régions actives
Authors: Dollfus Audouin
Published: July 2016

The ‘K-Coronameters’ in use since 1956 at Pic-du-Midi and Meudon Observatories for the study of the white-light corona were replaced in 1963 by new improved instruments.

The coronal activity was continuously recorded from 1964 to 1967. The electron density in the low corona and its variation with height are summarized by curves and maps.

A study is given of the corona streamers above the proton flares area in July and September 1966.
Observations of the solar proton event of August 28, 1966
Authors: Kinsey J. H. , McDonald F.B.
Published: July 2016

The CSI scintillator telescope aboard IMP-III indicated a peak intensity of 6·25 proton/sec cm2 ster for a SPE (Solar Proton Event) commencing during the period 1600 to 1700 UT on August 28, 1966. This SPE appears to have been associated with the importance 2–3 flare occurring at 22N/06S at 1522 UT on this date. The comparison of this event to other large proton events occurring during the period May 25, 1965 to September 30, 1966, is made.
Conditions of acceleration of solar electrons, and determination of the magnetic field in the high corona from the characteristics of a type-IV burst
Authors: Boischot A. , Clavelier B.
Published: July 2016

The study of a moving type-IV burst shows that acceleration of electrons can happen in the high corona, and a mechanism is proposed for such an acceleration. The low-frequency cut-off of radio spectrum is interpreted as due to the effect of the coronal plasma upon the synchrotron emission, and this leads to an accurate determination of the intensity of the magnetic field at an altitude of 1 R⊙. Then it is possible to compute the energy and the density of the relativistic electrons.
Systematic Errors of the Crimean Vector Magnetograph
Authors: Kotov V. A.
Published: July 2016

The influence of some ‘effective’ asymmetry (miscentering) of spectral line on the accuracy of the complete field vector is considered for the measurements with the Crimean magnetograph. This miscentering appears in the device for H⊥ records if the longitudinal field is strong.
A Short Report on the Magnetic Beam Absorption Filter Research at the Rome Astronomical Observatory
Authors: Cacciani A. , Cimino M. , Fofi M.
Published: July 2016

Some possible developments of magnetic beam absorption devices are described, in view of their very promising possibilities of practical application in the field of solar magnetic field observations.
Opposite Polarities in the Development of Some Regularities in the Distribution of Large-Scale Magnetic Fields
Authors: Ambrož P. , Bumba V. , Howard R. , Sýkora J.
Published: July 2016

When viewed separately in the two polarities, the large-scale pattern of magnetic fields on the Sun gives an appearance reminiscent of a very large cellular structure. These structures and their relation to ‘active longitudes’ are discussed.