Infrared astronomical satellite (IRAS) catalogs and atlases. Volume 1: Explanatory supplement

The Infrared Astronomical Satellite (IRAS) was launched on January 26, 1983. During its 300-day mission, IRAS surveyed over 96 pct of the celestial sphere at four infrared wavelengths, centered approximately at 12, 25, 60, and 100 microns. Volume 1 describes the instrument, the mission, and data reduction

Emulsification in binary liquids containing colloidal particles: a structure-factor analysis

We present a quantitative confocal-microscopy study of the transient and final microstructure of particle-stabilised emulsions formed via demixing in a binary liquid. To this end, we have developed an image-analysis method that relies on structure factors obtained from discrete Fourier transforms of individual frames in confocal image sequences. Radially averaging the squared modulus of these Fourier transforms before peak fitting allows extraction of dominant length scales over the entire temperature range of the quench. Our procedure even yields information just after droplet nucleation, when the (fluorescence) contrast between the two separating phases is scarcely discernable in the images. We find that our emulsions are stabilised on experimental time scales by interfacial particles and that they are likely to have bimodal droplet-size distributions. We attribute the latter to coalescence together with creaming being the main coarsening mechanism during the late stages of emulsification and we support this claim with (direct) confocal-microscopy observations. In addition, our results imply that the observed droplets emerge from particle-promoted nucleation, possibly followed by a free-growth regime. Finally, we argue that creaming strongly affects droplet growth during the early stages of emulsification. Future investigations could clarify the link between quench conditions and resulting microstructure, paving the way for tailor-made particle-stabilised emulsions from binary liquids.Comment: http://iopscience.iop.org/0953-8984/22/45/455102

Spin-Correlation Coefficients and Phase-Shift Analysis for p+3^3He Elastic Scattering

Angular Distributions for the target spin-dependent observables A$_{0y}$, A$_{xx}$, and A$_{yy}$ have been measured using polarized proton beams at several energies between 2 and 6 MeV and a spin-exchange optical pumping polarized $^3$He target. These measurements have been included in a global phase-shift analysis following that of George and Knutson, who reported two best-fit phase-shift solutions to the previous global p+$^3$He elastic scattering database below 12 MeV. These new measurements, along with measurements of cross-section and beam-analyzing power made over a similar energy range by Fisher \textit{et al.}, allowed a single, unique solution to be obtained. The new measurements and phase-shifts are compared with theoretical calculations using realistic nucleon-nucleon potential models.Comment: Submitted to Phys. Rev.

First order isotropic - smectic-A transition in liquid crystal-aerosil gels

The short-range order which remains when the isotropic to smectic-A transition is perturbed by a gel of silica nanoparticles (aerosils) has been studied using high-resolution synchrotron x-ray diffraction. The gels have been created \textit{in situ} in decylcyanobiphenyl (10CB), which has a strongly first-order isotropic to smectic-A transition. The effects are determined by detailed analysis of the temperature and gel density dependence of the smectic structure factor. In previous studies of the continuous nematic to smectic-A transition in a variety of thermotropic liquid crystals the aerosil gel appeared to pin, at random, the phase of the smectic density modulation. For the isotropic to smectic-A transition the same gel perturbation yields different results. The smectic correlation length decreases more slowly with increasing random field variance in good quantitative agreement with the effect of a random pinning field at a transition from a uniform phase directly to a phase with one-dimensional translational order. We thus compare the influence of random fields on a \textit{freezing} transition with and without an intervening orientationally ordered phase.Comment: 8 pages, 8 figure

On the shopfloor: exploring the impact of teacher trade unions on school-based industrial relations

Teachers are highly unionised workers and their trade unions exert an important influence on the shaping and implementation of educational policy. Despite this importance there is relatively little analysis of the impact of teacher trade unions in educational management literature. Very little empirical research has sought to establish the impact of teacher unions at school level. In an era of devolved management and quasi-markets this omission is significant. New personnel issues continue to emerge at school level and this may well generate increased trade union activity at the workplace. This article explores the extent to which devolved management is drawing school-based union representation into a more prominent role. It argues that whilst there can be significant differences between individual schools, increased school autonomy is raising the profile of trade union activity in the workplace, and this needs to be better reflected in educational management research

The Intrinsic Absorber in QSO 2359-1241: Keck and HST Observations

We present detailed analyses of the absorption spectrum seen in QSO 2359-1241 (NVSS J235953-124148). Keck HIRES data reveal absorption from twenty transitions arising from: He I, Mg I, Mg II, Ca II, and Fe II. HST data show broad absorption lines (BALs) from Al III 1857, C IV 1549, Si IV 1397, and N V 1240. Absorption from excited Fe II states constrains the temperature of the absorber to 2000K < T < 10,000K and puts a lower limit of 10^5 cm^{-3} on the electron number density. Saturation diagnostics show that the real column densities of He I and Fe II can be determined, allowing to derive meaningful constraints on the ionization equilibrium and abundances in the flow. The ionization parameter is constrained by the iron, helium and magnesium data to -3.0 < log(U) < -2.5 and the observed column densities can be reproduced without assuming departure from solar abundances. From comparison of the He I and Fe II absorption features we infer that the outflow seen in QSO 2359-1241 is not shielded by a hydrogen ionization front and therefore that the existence of low-ionization species in the outflow (e.g., Mg II, Al III, Fe II) does not necessitate the existence of such a front. We find that the velocity width of the absorption systematically increases as a function of ionization and to a lesser extent with abundance. Complementary analyses of the radio and polarization properties of the object are discussed in a companion paper (Brotherton et al. 2000).Comment: 30 pages, 9 figures, in press with the Ap

A Compendium of Far-Infrared Line and Continuum Emission for 227 Galaxies Observed by the Infrared Space Observatory

Far-infrared line and continuum fluxes are presented for a sample of 227 galaxies observed with the Long Wavelength Spectrometer on the Infrared Space Observatory. The galaxy sample includes normal star-forming systems, starbursts, and active galactic nuclei covering a wide range of colors and morphologies. The dataset spans some 1300 line fluxes, 600 line upper limits, and 800 continuum fluxes. Several fine structure emission lines are detected that arise in either photodissociation or HII regions: [OIII]52um, [NIII]57um, [OI]63um, [OIII]88um, [NII]122um, [OI]145um, and [CII]158um. Molecular lines such as OH at 53um, 79um, 84um, 119um, and 163um, and H2O at 58um, 66um, 75um, 101um, and 108um are also detected in some galaxies. In addition to those lines emitted by the target galaxies, serendipitous detections of Milky Way [CII]158um and an unidentified line near 74um in NGC1068 are also reported. Finally, continuum fluxes at 52um, 57um, 63um, 88um, 122um, 145um, 158um, and 170um are derived for a subset of galaxies in which the far-infrared emission is contained within the ~75" ISO LWS beam. The statistics of this large database of continuum and line fluxes, including trends in line ratios with the far-infrared color and infrared-to-optical ratio, are explored.Comment: Accepted for publication in the Astrophysical Journal Supplement Serie

High-resolution x-ray study of the nematic - smectic-A and smectic-A - smectic-C transitions in 8barS5-aerosil gels

The effects of dispersed aerosil nanoparticles on two of the phase transitions of the thermotropic liquid crystal material 4-n-pentylphenylthiol-4'-n-octyloxybenzoate 8barS5 have been studied using high-resolution x-ray diffraction techniques. The aerosils hydrogen bond together to form a gel which imposes a weak quenched disorder on the liquid crystal. The smectic-A fluctuations are well characterized by a two-component line shape representing thermal and random-field contributions. An elaboration on this line shape is required to describe the fluctuations in the smectic-C phase; specifically the effect of the tilt on the wave-vector dependence of the thermal fluctuations must be explicitly taken into account. Both the magnitude and the temperature dependence of the smectic-C tilt order parameter are observed to be unaffected by the disorder. This may be a consequence of the large bare smectic correlation length in the direction of modulation for this transition. These results show that the understanding developed for the nematic to smectic-A transition for octylcyanobiphenyl (8CB) and octyloxycyanobiphenyl (8OCB) liquid crystals with quenched disorder can be extended to quite different materials and transitions.Comment: 7 pages, 8 figure