bluuebunny/crossref_metadata_2025_split huggingface dataset:
First results of an international multisite multitechnique campaign on o micron And
Authors: Sareyan J.P. , Chauville J. , Briot D. , Adelman S.J. , Alvarez M. , Balega I. , Balega Y. , Bardin D. , Belkin I. , Bonneau D. , Bossi M. , Desnoux V. , Espoto M. , Fried R. , Gonzalez-Bedolla S. , Guo X.Z. , Guo Y.L. , Hao J.X. , Huang L. , Klotz A. , Leister N. , Morand F. , Mourard D. , Vakili F. , Valera F. , Zhao F.Y. 
Published: July 2016

Omicron Andromedae is a multiple system of at least four stars: a B ↔Be star (component A), a spectroscopic binary (components B1–B2) and a close companion (component a). According to several studies (see Hill et al. 1988, 1989):
-the distance between A and the B1–B2 system decreased from 0.39″ in 1975 to 0.25″ in 1987 (McAlister and Hartkopf 1988)-the few previous speckle measurements of component a have shown the possibility of a 3.7 years orbit around A, according to the 1975 to 1984 observations (mean distance 0.05″). The calculations with this 3.7 yr orbit lead to the prediction of a maximum distance of 0.77″ at 1992.738, i.e. at the end of september 1992, with a North-South orientation.
The number of Be stars compared with the number of B stars, taking into account the specific physical characteristics of Be stars
Authors: Briot D. , Zorec J. 
Published: July 2016

It is very important for the understanding of the Be phenomenon, and particularly for locating a possible Be phase in the evolutionary track of B stars, to accurately determine the proportion of Be stars among all B stars. This type of study was already made several times in the past. Results obtained generally show a maximum Be frequency around spectral type B2 then a decrease towards late spectral types. Actually Be stars do not have the same characteristics as “normal” B stars and we have to take this into account in the determination of the ratio : number of Be stars / number of B stars. We use the Bright Star Catalogue (Hoffleit & Jaschek 1982) and the Supplement to the Bright Star Catalogue (Hoffleit, Saladyga & Wlasuk 1983) containing stars V= 7.10 and brighter. This study needed to be made separately for the different spectral types because:- Physical parameters of B stars are very different from B0 to B9;- Emission characteristics of Be stars vary very much, with a decrease from B0e to B9e.We successively consider three effects which can influence the frequency of Be stars:- The over-luminosity of Be stars as compared with B stars;- Spectral type changes during constant mass evolution;- Spectral type changes due to the fast rotation of Be stars.
Gravitational Microlensing, The Distance Scale, And The Ages
Authors: Paczyński Bohdan 
Published: July 2016

A high optical depth to gravitational microlensing towards the galactic bulge is consistent with current models of the galactic bar. The low optical depth towards the LMC can probably be accounted for by the ordinary stars in our galaxy and in the LMC itself. No conclusive evidence is available yet for the presence or absence of a large number of brown dwarfs or other non-stellar compact objects which might account for the dark matter. There is little doubt that the amount of mass in objects in the range 10–8 ≤ M/M⊙ ≤ 106 will be determined within the next few years with the continuing and expanding searches.Billions of photometric measurements generated by the microlensing searches have lead to the discovery of ∼ 105 variable stars. In particular, a number of detached eclipsing binaries were discovered in the galactic bulge, in the LMC, and in the globular cluster Omega Centauri. The follow-up observations of these binaries will allow the determination of accurate distances to all these objects, as well as robust age determination of globular clusters.
NIR Imaging of the Box/Peanut Bulge in NGC 4302
Authors: Dettmar R.-J. , Ferrara A. 
Published: July 2016

The central, spheroidal component of spiral galaxies is frequently found to be “box- or peanut” (b/p) shaped. More than 30% of edge-on galaxies may show this phenomenon (Dettmar 1995). To explain this large frequency a very common process for the origin of this specific shape is required. N-body simulations have shown that this can be attributed to instabilities and resonances caused by bars in spiral disks (e. g., Combes et al. 1990, Raha et al. 1991).Previous statistics (Jarvis 1986, Shaw 1987, de Souza & dos Anjos 1987) are hampered by the low dynamic range of the photographic material used as well as by dust absorption in late type spirals and the difficulty to disentangle disk and bulge in such systems. We present K-band imaging of the very dusty edge-on galaxy NGC 4302 in the Virgo cluster supporting the presence of b/p bulges in late type spirals.NIR Observations were obtained with the NICMOS-3 ARNICA camera at TIRGO1 in spring 1994. The combined image of NGC 4302 clearly shows a flat-top “boxy” structure of the spheroid and an additional very thin component appears on the major axis cut. This latter component could be identified with a bar. The example of NGC 4302 demonstrates that b/p bulges are indeed present in disks of late type spirals and that bars can account for a significant fraction of these structures. As a consequence, the bulge/disk ratio of late type spirals has to be interpreted in an evolutionary scenario rather than as a primordial property.
A Linkup Between Seyfert's and their Surroundings
Authors: Mahtessian A.P. , Khachikian E.Ye. , Tiersch H. 
Published: July 2016

The observed physical characteristics of galaxies are (at least partly) determined by the influence of the surroundings after the formation of the galaxies. The examination of the frequency of the occurence of active galaxies, i.e. Seyfert galaxies, in different galaxy systems compared to a sample of field galaxies gives possibly an insight into this problem.The galaxy groups were taken from the CfA redshift survey, the list of them is published in Mahtessian (1992, Soob. Byurakan. Obs. 65).
Mechanisms for Flash Phase Phenomena in Solar Flares
Authors: Smith Dean F. 
Published: July 2016

Mechanisms for explaining the various forms of particles and radiation observed during the flash phase of solar flares are reviewed under the working hypothesis that the flash phase is the time in which electrons and to a lesser degree protons are accelerated in less than one second. A succession of such accelerations is allowed to explain longer lasting or quasi-periodic phenomena. Mechanisms capable of such acceleration are reviewed and it is concluded that first-order Fermi acceleration in a reconnecting current sheet is the most likely basic process. Such acceleration, however, gives rise to a rather narrow distribution of particle velocities along a given field line which is unstable to the production of electron plasma and ion-acoustic waves. This plasma turbulence can heat the plasma to produce soft X-rays and filter the initially narrow velocity distribution to produce a power law energy distribution. Electrons travelling inward from the acceleration region produce hard X-rays by bremsstrahlung and microwave bursts by gyro-synchrotron emission. Whereas the interpretation of X-ray spectra is relatively straightforward, the interpretation of microwave spectra is difficult because the source at low frequencies can be made optically thick by several different mechanisms.Electrons travelling further inward presumably thermalize and produce impulsive EUV and Hα emission. The theory for these emissions, although amenable to present techniques in radiative transfer, has not been worked out. Electrons travelling outward give rise to type III radio bursts by excitation of electron plasma waves and the electrons observed at the Earth. Study of the interaction of a stream of electrons with the ambient plasma shows that the electron spectra observed at the Earth do not necessarily reflect their spectrum at the acceleration region since they interact via plasma waves as well as through Coulomb collisions. The mechanisms for the conversion of plasma waves into radiation and the propagation of the radiation from its source to the observer are reviewed.
On the Thermal Interpretation of Hard X-Ray Bursts from Solar Flares
Authors: Brown John C. 
Published: July 2016

The possible validity of thermal bremsstrahlung models of flare hard X-ray bursts is investigated quantitatively. In particular, the problem of rapid thermal conduction in ‘multi-temperature’ models is adequately examined for the first time by using a continuous temperature distribution consistent with the observed X-ray spectrum. This distribution is obtained from a general analytic solution for the temperature structure required to mimick any ‘non-thermal’ spectrum, the method being equally applicable to cosmic sources.It is concluded that the thermal interpretation might extend to X-rays of hundreds of keV, a result with important consequences for flare energetics. The relationship of such a model to observations of X-ray polarization and rapid time variations is also considered.
2. Magneto-hydrodynamic waves in compressible fluids by finite viscosity and heat conductivity
Authors: Baños Alfredo 
Published: July 2016

The general theory of magneto-hydrodynamic waves in an ideal conducting fluid embedded in a uniform field of magnetic induction, and the application of the theory to the systematic analysis of the various modes of propagation in incompressible and compressible fluids have been presented by the author in two earlier papers[1, 2]. In these papers, however, no effort was made to include the thermodynamics of the situation, which amounts to the tacit assumption that the fluid is of zero heat conductivity. In this case the resulting modes are of two kinds: isothermal (v-modes) and adiabatic (p-modes).In this paper we first establish the conservation laws of momentum and energy for a (macroscopic) compressible fluid with finite viscosity and finite thermal and electrical conductivities, which is embedded in a uniform field of magnetic induction, and we then derive quite generally the exact (nonlinearized) equation governing the distribution of temperature in such a fluid. Next, making use of the linearized magneto-hydrodynamic wave equation in the fluid velocity, combined with the resulting heat diffusion equation and with the equation of state of the fluid, and applying the mathematical techniques developed earlier, we obtain a higher order partial differential equation in the fluid temperature from which ensue all the temperature modes.In particular, we examine in detail the behavior of plane homogeneous waves, and it is shown that a compressible fluid with the indicated properties sustains altogether six different modes, two of which are pure shear modes, devoid of density, pressure, and hence temperature fluctuations (v-modes), while the remaining four are shear-compression waves accompanied necessarily by density, pressure, and temperature fluctuations (p-modes). The two shear modes, which are isothermal, comprise a slightly attenuated Alfvén wave, and a highly attenuated viscous mode, sometimes referred to as a vorticity mode. The four shear-compression modes have in general very complex properties, but in the low frequency and low heat conductivity case they are easily identified as (1) a modified (adiabatic) sound wave slightly attenuated; (2) a slightly attenuated modified Alfvén p-wave; (3) a highly attenuated viscous wave; and (4) a highly attenuated thermal wave governed in the main by the thermal properties of the medium.
4. Non-stable magneto-hydrodynamical processes in stars
Authors: Kipper A. J. 
Published: July 2016

1. The behaviour of the magnetic field of a star was investigated by Cowling, Lamb and Wrubel on the assumption of the star as a solid body and on the assumption that the field variations caused by the extinction do not create any motions of the stellar matter. The important results obtained make possible the interpretation of magneto-hydrodynamical processes in stars only quite roughly. When motions of stellar matter caused by the electromagnetic forces are taken into account new properties may be revealed and the non-stability of the magneto-hydrodynamical processes in stars established. Entangled magnetic fields are the general expression of non-stability.2. The mathematical criterion of a confused stellar magnetic field is given in the preceding paper from the magneto-hydrodynamical equations for an ideal incompressible fluid. The conception of a confused field as a superposition of various fields of different scales is introduced.3. It is known that the presence of a magnetic field causes an increase of the stability of hydrodynamical processes, as compared with processes in the absence of a magnetic field. It may most probably be concluded that the extent of confusion of a magnetic field is not the same, as it happens as a result of ordinary turbulent motions in a liquid. However, owing to magneto-hydrodynamical formulae, it may be stated in the present paper that if the field confusion is considered as a superposition of fields of different dimensions and not as a field of entangled magnetic lines, no stability of the above kind can be expected.4. The theory of a totally entangled magnetic field, as a field in a state of maximum confusion is examined. A very close similarity between a totally entangled magnetic field and the turbulent motion in a viscous liquid is established. The question of the time of extinction of a magnetic field of a star is discussed.Note. Sections 1, 2, 4 of the paper are based upon the results obtained by the author, reported by him at the 4th Cosmological Conference. Section 3 contains unpublished results.
37. Correlation between cosmic ray intensity and geomagnetic activity
Authors: Venkatesan D. 
Published: July 2016

The Chree method of analysis has been adopted for the analysis of the Ionization Chamber data for Huancayo, Cheltenham and Godhavn for 1946 and for the former two stations for 1945. The same procedure is adopted for the planetary index Kp also.The cosmic ray minimum (or maximum) precedes the minimum (or maximum) of Kp by about 4–5 days. It is also observed that the relative decrease in cosmic ray intensity per day, – ΔI/(I. Δt), follows the changes in Kp in a general way, and hence the electric field as would be expected from the consideration of the theory of emission of beams of particles from the sun with the associated frozen magnetic field and the electric field arising due to polarization.
38. Solar production and modulation of cosmic rays, and their propagation through interplanetary space
Authors: Simpson J. A. 
Published: July 2016

The principal characteristics for changes of cosmic ray intensity as a function of time and primary particle energy are reviewed for those intensity variations which are thought to be of non-terrestrial origin. These variations are either (a) temporary increases of cosmic ray intensity arising from thede novoproduction of cosmic ray particles in the vicinity of the sun in association with some solar flares, or (b) the modulation of extra-solar cosmic radiation within the interplanetary volume by a modulation mechanism related to solar activity.The study of these variations for low-energy cosmic ray particles is also a unique tool for the investigation of interplanetary magnetic fields and other properties of interplanetary space. As an example, the cosmic ray events associated with the giant solar flare of 23 February 1956 have been studied. The experimental evidence shows that interplanetary magnetic fields must exist for the storage and redistribution of the solar flare cosmic ray particles. A more specific model indicates that disordered magnetic fields lie mainly beyond the orbit of the earth and that diffusion through these irregular magnetic fields is the prominent mechanism for particle storage. In addition, this cosmic ray intensity increase was fortunately superposed in such a way upon a change of intensity arising from a modulation mechanism that it is possible to restrict the kinds of models which account for modulation of cosmic ray intensity within the interplanetary volume.
Random affine code tree fractals: Hausdorff and affinity dimensions and pressure
Authors: JÄRVENPÄÄ ESA , JÄRVENPÄÄ MAARIT , WU MENG , WU WEN 
Published: July 2016

AbstractWe prove that for random affine code tree fractals the affinity dimension is almost surely equal to the unique zero of the pressure function. As a consequence, we show that the Hausdorff, packing and box counting dimensions of such systems are equal to the zero of the pressure. In particular, we do not presume the validity of the Falconer–Sloan condition or any other additional assumptions which have been essential in all the previously known results.
Sustainability Concepts in Indigenous and Non-Indigenous Cultures
Authors: Throsby David , Petetskaya Ekaterina 
Published: July 2016

Abstract:The concepts of sustainability, and of the more specific notion of sustainable development, have become entrenched in national and international policy making over the last half century. However, little attention has been paid to sustainability as it relates to indigenous communities. This article discusses sustainability concepts as understood in indigenous and non-indigenous societies, drawing a number of illustrations from the experiences and practices of the Aboriginal and Torres Strait Islander peoples of Australia. We point out that the two approaches to sustainability share many common concerns, although significant differences are evident. While the paradigm of sustainability can be seen as a universal concept that can be applied irrespective of social, political, or cultural context, it is argued that a fully realized model of sustainability for application in non-indigenous societies will only be possible if it acknowledges the importance of culture and incorporates the insights that have been accumulated over generations in indigenous knowledge systems.
Cities as biological computers
Authors: Pasquero Claudia , Poletto Marco 
Published: July 2016

In this paper the authors propose a conceptual model and a bio-computational design method to articulate the world's Urbansphere, suggesting new terms for its co-evolution with the Biosphere.The proposed model responds to principles of biological self-organisation, and operates by embedding a numerical/computational engine, a living Physarum polycephalum, onto a spatial/morphogenetic substratum, a Satellite driven informational territory. This integration is embodied in the Physarum Machine, a bio-digital design apparatus conceived by the authors and further developed within the Urban Morphogenesis Lab at the UCL in London.The use of specifically designed apparatus of material computation to demonstrate and solve problems of urban morphogenesis is not new and the authors refer to the work of German Architect Frei Otto and his theory for the occupation and connection of territories.This research leads to a notion of bio-city of the future where manmade infrastructures and non-human biological systems will constitute parts of a single biotechnological whole. To this respect it can be read as a manifesto for the extension of biotechnology to the scale of the Biosphere (biosphere geo-engineering) by expanding the scope and material articulation of global informational and energetic infrastructures (the internet of things and the internet of energy).In the tradition of design based research, the paper also suggests an application of the proposed model to a specific case study demonstrating its efficacy in the re-conceptualization of the post-industrial and ecologically depleted landscapes of eastern Arizona. In conclusion the experiment describes the potential of augmenting materiality through sensors and microprocessors so that it would become possible to harvest the computational power latent in micro-organisms like the slime mould.The dream outlined here is for an era where descriptive computation will be superseded by our capability to simulate and compute through the world that surrounds us.
Buds of the tree: the highway to the last universal common ancestor
Authors: de Farias Savio Torres , Prosdocimi Francisco 
Published: July 2016

AbstractThe last universal common ancestor (LUCA) has been considered as the branching point on which Bacteria, Archaea and Eukaryotes have diverged. However, the increased information relating to viruses’ genomes and the perception that many virus genes do not have homologs in other organisms opened a new discussion. Based on these facts, there has emerged the idea of an early LUCA that should be moved further into the past to include viruses, implicating that life should have originated before the appearance of cellular life forms. Another point of view from advocates of the RNA-world suggests that the origin of life happened a long time before organisms were capable of organizing themselves into cellular entities. Relevant data about the origin of ribosomes indicate that the catalytic unit of the large ribosomal subunit is what should actually be considered as the turning point that separated chemistry from biology. Other researchers seem to think that a tRNA was probably some sort of a strange attractor on which life has originated. Here we propose a theoretical synthesis that tries to provide a crosstalk among the theories and define important points on which the origin of life could have been originated and made more complex, taking into account gradualist assumptions. Thus, discussions involving the origin of biological activities in the RNA-world might lead into a world of progenotes on which viruses have been taken part until the appearance of the very first cells. Along this route of complexification, we identified some key points on which researchers may consider life as an emerging principle.