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This study of the activity in the nuclei of normal galaxies began as an investigation into the spread in the observed properties of normal galaxies used as standard candles in measurements of departures from the Hubble flow (Hart & Davies 1982). Extensive studies of the integrated properties of normal galaxies show the influence on these properties of quiescent star formation and embedded starburst-type activity (Staveley-Smith & Davies, 1987,1988). Normal galaxies have a significant level of nuclear activity, although it is not strongly correlated with their integrated properties. This investigation of nuclear activity is based on a sample of the 100 brightest nearby Sbc galaxies, a sample unbiassed in its selection of activity.
In this paper we present preliminary results from 21-cm line observations with the Very Large Array (VLA) of the southern barred spiral galaxies NGC 1365 and NGC 1097. Despite a wealth of theoretical models describing the gas flow in a non-axisymmetric bar potential (see Prendergast this volume), few observations of the HI distribution and motions in barred spiral galaxies exist. A notable exception is NGC 5383 (Sancisi et al. 1979). The observations we performed with the VLA are described below. The velocity resolution is 25 km sec−1. The angular resolution is 28″x20″, p.a. 20° for NGC 1365 and 30″x25″, p.a. 20° for NGC 1097. Velocities are heliocentric.
The constraints on cosmic ray electron sources and propagation as derived from radio continuum observations of galaxies are reviewed. Special attention is paid to the inferences which can be obtained from the radio continuum properties of spiral galaxies seen edge-on.
We have mapped the southern galaxies NGC 613, 1313, 1433, 1566, 1672, and 2442 in the 12CO(1-0) line with the SEST telescope. The sample bases on galaxies observed previously in radio continuum at the Molonglo Observatory (Harnett, 1985).
Salivary glycoprotein profiles, obtained after boronic acid enrichment, were studied for the first time in pigs in order to search for specific overall alterations related to acute inflammatory condition. Five healthy pigs and five pigs suffering from rectal prolapse were used, and the levels of acute phase proteins were measured to determine the degree of inflammation of the animals. The enriched glycoprotein profiles, achieved by two-dimensional gel electrophoresis (2DE) were statistically evaluated and spots that appeared differentially regulated between states were subjected to MS analysis for protein identification. Spots from three unique proteins were identified: carbonic anhydrase VI (CA VI), α-1-antichymotrypsin and haptoglobin (Hp). CA VI appeared as two adjacent horizontal spot trains in the glycoprotein profile of healthy animals in its regular isoelectric points (pI). One spot of α-1-antichymotrypsin was found in saliva from pigs with rectal prolapse in an unusual basic pI, and was considered as a breakdown product. Hp was identified as several spot trains in saliva from pigs with rectal prolapse in an unusual alkaline pI and was consequently further investigated. SDS-PAGE and 2DE of paired serum and saliva samples combined with Western blot analysis showed that the unusual Hp position observed in saliva samples was absent in serum. Furthermore, N-glycans from serum and saliva Hp glycopatterns were evaluated from SDS-PAGE Hp bands and showed that the serum N-glycan distribution in Hp β-chain was comparable in quantity and quality in both groups of animals. In saliva, no Hp β-chain derived N-glycans could unambiguously be identified from this sample set, thus needing further detailed investigations in the future.
Since 1982, we are performing a long-term spectroscopic observing programme of emission-lines in Be stars (Hanuschik 1987, Hanuschik et al. 1988, Dachs et al. 1992, Sutorius 1992, Dietle 1993). We are using ESO's 1.4m CAT, at resolution R ≥ 50 000 and S/N = 100–1000. Spectral lines chosen are the optically thick Hα, Hβ lines and the optically thin Fe ii λ5317 line. The latter line is an extremely sharp tracer (Δvth = 2 km s−1) for the kinematics in the disks. We believe that our atlas shows the full range of intrinsic structure of these emission lines.
We have mapped the southern galaxies NGC 613, 1313, 1433, 1566, 1672 and 2442 in the 12CO(J = 1 → 0) transition with the 15-m Swedish European Submillimetre Telescope (SEST). The sample is based on galaxies previously observed in radio continuum with the Molonglo Observatory Synthesis Telescope (MOST). Strong emission is seen from the barred galaxies NGC 613 and NGC 2442 and from the active galaxies NGC 1566 and 1672. The weakest emission was from NGC 1433, while the Sd spiral NGC 1313 was not detected.
New radio continuum and spectral line observations of the Galactic radio source G18.95-1.1 are reported. The distance to G18.95-1.1 is 2 kpc as derived from HI-21 cm spectral line observations. These data also indicate an interaction with the interstellar medium. The radio continuum observations classify G18.95-1.1 as a composite supernova remnant.
Carbon-14 is an important radionuclide in the inventory of radioactive waste and is considered to be a key radionuclide in performance assessment. In Switzerland, the 14C inventory in a cement-based repository for low- and intermediate-level radioactive waste is mainly associated with activated steel (∼85%). Anaerobic corrosion of the activated steel will determine the time-dependent release of 14C-bearing compounds from the cementitious near field into the host rock. The present study was carried out to provide an overview on the current state of the art knowledge regarding the carbon speciation during the anaerobic corrosion of activated and non-activated iron/steel and to critically assess the capability of thermodynamic modelling to predict 14C speciation in anoxic alkaline conditions. Previous experimental work showed the presence of oxidized and reduced hydrocarbons during corrosion in iron-water systems in anoxic (near neutral to alkaline) conditions which appears to be inconsistent with the negative redox potential of the system. The capability of thermodynamic modelling to predict the carbon speciation in these conditions was found to be limited due to uncertainties associated with the concept of metastability in the C–H–O system.
From radio continuum observations it is known that the central regions of galaxies can be an important source of cosmic rays, in particular relativistic electrons. In order to get some insight in the properties of the central sources and their dependence on optical properties, especially morphological type, a large sample of galaxies (~ 400) was observed with the Westerbork Synthesis Radio Telescope at 1.4 GHz. The sample definitions, observations, reduction, survey characteristics and the analysis of the data are given in Hummel (1980, 1980a). Here we will concentrate on the results obtained for the central sources (> 20″).
Gravitational interaction is a straightforward interpretation of some of the peculiar optical morphologies shown by galaxies. There have also been attempts to study the effects of a gravitational interaction on the radio continuum emission. Statistically, the central radio sources (inner 1 kpc) in interacting spiral galaxies are about three times stronger than in isolated spirals; on the other hand, the intensity of the extended emission does not seem to be affected (Stocke, 1978; Hummel, 1981). Peculiar radio morphologies are not a general property of interacting galaxies, since in the complete sample studied by Hummel (1981) of spirals with a probability ≥0.8 of being physically related to their companion, less than 5% have a peculiar radio morphology.
In the wake of the recent terrorist attacks, such as the 2008 Mumbai hotel explosion or the December 25th 2009 “underwear bomber”, our group has developed a technique (US patent #7368292) to apply differential reflective spectroscopy to the problem of detecting explosives in order to detect terrorist threats. Briefly, light (200-500 nm) is shone on a surface such as a piece of luggage at an airport or a parcel at a courier distribution center. Upon reflection, the light is collected with a spectrometer combined with a camera. A computer processes the data and produces in turn a differential reflection spectrum taken between two adjacent areas of the surface. This differential technique is highly sensitive and provides spectroscopic data of explosives. As an example, 2,4,6, trinitrotoluene (TNT) displays strong and distinct features in differential reflectograms near 420 nm. Similar, but distinctly different features are observed for other explosives such as RDX, PETN or ANFO. Our detection system uses a two dimension detector (CCD camera) which provide spatial and spectroscopic information in each of the two dimensions. By scanning (involving fixed optical equipment and scanning moving bags or parcels on a conveyor belt), the surface to be surveyed the system provide the spatial location of the potential threat. We present in this paper how our detector works and how it is applied to the problem of explosive screening for explosives at airports and mail sorting centers. Additionally, we will present the effect of the explosives morphology on the detection response. In particular we will evaluate the implication on the limit of detection of the instrument as well as discuss the sample morphology with respect to a realistic threat scenario.
Porous silicon which has been prepared by a “dry” technique, that is, by spark erosion, yields similar photoluminescence spectra as anodically etched porous silicon which has been prepared in aqueous solutions. Fourier transform infrared spectra reveal that the dominant features in spark eroded silicon are the Si-O-Si stretching mode and the Si-O-Si bending mode. No infrared vibrational modes characteristic for siloxene have been found in spark eroded Si. Results from X-ray and electron diffraction studies suggest that spark eroded Si involves minute polycrystalline silicon particles which are imbedded in an amorphous matrix.
The effects of energetic Ar cluster ion impacts on Si(111) surfaces have been studied for cluster energies up to l5keV. The mean cluster size was about 1000 atoms, and the smaller sizes could be systematically excluded. Si samples irradiated at different cluster ion energies were analyzed by RBS, ellipsometry, and differential reflectometry. Implantation of Ar in samples irradiated with cluster ions was found by RBS to be detectable, but very small in comparison with samples irradiated with monomer ions of the same energy. The thickness of the damage layer as measured by both ellipsometry and differential reflectometry was also much smaller in the cluster ion irradiated samples.