Do micro brown dwarf detections explain the galactic dark matter?

Context: The baryonic dark matter dominating the structures of galaxies is widely considered as mysterious, but hints for it have been in fact detected in several astronomical observations at optical, infrared, and radio wavelengths. We call attention to the nature of galaxy merging, the observed rapid microlensing of a quasar, the detection of "cometary knots" in planetary nebulae, and the Lyman-alpha clouds as optical phenomena revealing the compact objects. Radio observations of "extreme scattering events" and "parabolic arcs" and microwave observations of "cold dust cirrus" clouds are observed at 15 - 20 K temperatures are till now not considered in a unifying picture. Aims: The theory of gravitational hydrodynamics predicts galactic dark matter arises from Jeans clusters that are made up of almost a trillion micro brown dwarfs (mBDs) of earth weight. It is intended to explain the aforementioned anomalous observations and to make predictions within this framework. Methods: We employ analytical isothermal modeling to estimate various effects. Results: Estimates of their total number show that they comprise enough mass to constitute the missing baryonic matter. Mysterious radio events are explained by mBD pair merging in the Galaxy. The "dust" temperature of cold galaxy halos arises from a thermostat setting due to a slow release of latent heat at the 14 K gas to solid transition at the mBD surface. The proportionality of the central black hole mass of a galaxy and its number of globular clusters is explained. The visibility of an early galaxy at redshift 8.6 is obvious with most hydrogen locked up in mBDs. Conclusions: Numerical simulations of various steps would further test the approach. It looks promising to redo MACHO searches against the Magellanic clouds.Comment: 12 pages A&A tex, 3 pdf figure

Theoretical p Mode Oscillation Frequencies for the Rapidly Rotating Delta Scuti Star Alpha Ophiuchi

A rotating, two dimensional stellar model is evolved to match the approximate conditions of Alpha Oph. Both axisymmetric and nonaxisymmetric oscillation frequencies are computed for 2D rotating models which approximate the properties of Alpha Oph. These computed frequencies are compared to the observed frequencies. Oscillation calculations are made assuming the eigenfunction can be fit with six Legendre polynomials, but comparison calculations with eight Legendre polynomials show the frequencies agree to within about 0.26% on average. The surface horizontal shape of the eigenfunctions for the two sets of assumed number of Legendre polynomials agrees less well, but all calculations show significant departures from that of a single Legendre polynomial. It is still possible to determine the large separation, although the small separation is more complicated to estimate. With the addition of the nonaxisymmetric modes with |m| less than or equal 4, the frequency space becomes sufficiently dense that it is difficult to comment on the adequacy of the fit of the computed to the observed frequencies. While the nonaxisymmetric frequency mode splitting is no longer uniform, the frequency difference between the frequencies for positive and negative values of the same m remains 2m times the rotation rate.Comment: ApJ accepte

The Variable Stars of the Draco Dwarf Spheroidal Galaxy - Revisited

We present a CCD survey of variable stars in the Draco dwarf spheroidal galaxy. This survey, which has the largest areal coverage since the original variable star survey by Baade & Swope, includes photometry for 270 RR Lyrae stars, 9 anomalous Cepheids, 2 eclipsing binaries, and 12 slow, irregular red variables, as well as 30 background QSOs. Twenty-six probable double-mode RR Lyrae stars were identified. Observed parameters, including mean V and I magnitudes, V amplitudes, and periods, have been derived. Photometric metallicities of the ab-type RR Lyrae stars were calculated according to the method of Jurcsik & Kovacs, yielding a mean metallicity of = -2.19 +/- 0.03. The well known Oosterhoff intermediate nature of the RR Lyrae stars in Draco is reconfirmed, although the double-mode RR Lyrae stars with one exception have properties similar to those found in Oosterhoff type II globular clusters. The period-luminosity relation of the anomalous Cepheids is rediscussed with the addition of the new Draco anomalous Cepheids.Comment: Accepted to AJ. 61 pages, 14 figures, 10 table

Exciton-polariton emission from organic semiconductor optical waveguides

We photo-excite slab polymer waveguides doped with J-aggregating dye molecules and measure the leaky emission from strongly coupled waveguide exciton polariton modes at room temperature. We show that the momentum of the waveguide exciton polaritons can be controlled by modifying the thickness of the excitonic waveguide. Non-resonantly pumped excitons in the slab excitonic waveguide decay into transverse electric and transverse magnetic strongly coupled exciton waveguide modes with radial symmetry. These leak to cones of light with radial and azimuthal polarizations

Sekvensanalyse av PRV-1-isolater fra tidsrommet da HSMB brøt ut i Norge

Piscine orthoreovirus-1 (PRV-1) is the causative agent of heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon, first described in Norway in 1999. Not all infected fish develop HSMI, and the virus has been revived from archived samples dating back to 1988, leading to a hypothesis that viral evolution has generated new genotypes with increased virulence contributing to disease development. The objective was to identify PRV-1 isolates present in Norwegian farmed salmon in the years before and after 1999. Archived samples from Norwegian farmed salmon, comprising 204 samples from 1987-2008, were screened for PRV- 1. Coding sequences were obtained for segment S1, S4, M2, L1 and L2, putatively linked to virulence, from six isolates. Phylogenetic analysis and genogrouping was performed. Screening displayed that PRV-1 was common in farmed salmon predating the first described HSMI- outbreak, and sequence analysis demonstrated a mixture of assumed high and low virulent isolates following 1999. Coinfection with isolates belonging to different phylogenetic groups was demonstrated in two fish from 1998 and 2005. Co-infection is a prerequisite for reassortment, linked to the hypothesis of the origin of the high virulent strains through evolution. In the presumed receptor binding protein σ1, a new amino acid change was discovered (E254K).Piscine orthoreovirus-1 (PRV-1) er årsaken til hjerte- og skjelettmuskelbetennelse (HSMB) hos oppdrettslaks, først beskrevet i Norge i 1999. Alle PRV-1-infiserte fisk utvikler imidlertid ikke HSMB og viruset har blitt detektert helt tilbake til 1988, som har ført til en hypotese om at viral evolusjon har generert nye genotyper med økt virulens som har bidratt til sykdomsutvikling. Hovedmålet med studien var å kartlegge genomet til PRV-1-isolater før og etter første beskrevne HSMB-utbrudd. 204 arkiverte prøver fra norsk oppdrettslaks fra 1987-2008 ble screenet for PRV-1. Kodende sekvens ble sekvensert for segment S1, S4, M2, L1 og L2, antatt koblet til virulens, fra seks isolater. Fylogenetisk analyse og genogruppering ble utført. Screeningen viste at PRV-1 var et vanlig forekommende virus hos oppdrettslaks allerede før det første beskrevne HSMB-utbruddet og sekvensanalysen demonstrerte en blanding av antatt høyvirulente og lavvirulente isolater i tidsperioden etter 1999. Studien påviste også koinfeksjon med to isolater tilhørende ulike fylogenetiske grupper hos to fisk, fra 1998 og 2005. Koinfeksjon er en forutsetning for reassortering, som knyttes til hypotesen om at høyvirulente stammer har oppstått gjennom reassortering av ulike lavvirulente stammer. I det antatt reseptorbindende proteinet σ1 ble det oppdaget en ny aminosyreendring (E254K

Investigation Into Laser Shock Processing

Laser shock processing is a good candidate for surface industry due to its rapid processing, localized ablation, and precision of operation. In the current study, laser shock processing of steel was considered. The numerical solutions for temperature rise and recoil pressure development across the interface of the ablating front and solid are presented. The propagation of elastic-plastic waves in the solid due to recoil pressure loading at the surface is analyzed and numerical solution for the wave propagation was obtained. An experiment was conducted to ablate the steel surfaces for shock processing. Scanning electron microscopy was carried out to examine the ablated surfaces shock processing while transmission electron microscopy was conducted to obtain dislocation densities after the shock processing. It was found that surface hardness of the workpiece increased in the order of 1.8 times of the base material hardness, and the dislocation was the main source of the shock hardening in the region affected by laser shock processing

Advanced power plant training simulator for VVER-440/V230 nuclear power plants

An advanced, workstation based, nuclear power plant simulator has been developed for use in training the operational staff of the Bohunice Nuclear Power Plant. This training simulator uses state-of- the-art computer hardware and software and provides the capability to simultaneously include six members of the power plant operating staff in the training sessions. A detailed reactor model has been developed, representing the Bohunice VVER-44O/V230 plants, for use with the RELAP5 simulation software. In addition, a comprehensive validation program has been completed that compares the simulation results of the advanced simulator with the results from a current VVER-44O/V230 simulator. A summary of the training features and capabilities of the simulator is also provided