A Chandra Survey of the X-ray Properties of Broad Absorption Line Radio-Loud Quasars

This work presents the results of a Chandra study of 21 broad absorption line (BAL) radio-loud quasars (RLQs). We conducted a Chandra snapshot survey of 12 bright BAL RLQs selected from SDSS/FIRST data and possessing a wide range of radio and CIV absorption properties. Optical spectra were obtained nearly contemporaneously with the Hobby-Eberly Telescope; no strong flux or BAL variability was seen between epochs. We also include in our sample 9 additional BAL RLQs possessing archival Chandra coverage. We compare the properties of (predominantly high-ionization) BAL RLQs to those of non-BAL RLQs as well as to BAL radio-quiet quasars (RQQs) and non-BAL RQQs for context. All 12 snapshot and 8/9 archival BAL RLQs are detected, with observed X-ray luminosities less than those of non-BAL RLQs having comparable optical/UV luminosities by typical factors of 4.1-8.5. (BAL RLQs are also X-ray weak by typical factors of 2.0-4.5 relative to non-BAL RLQs having both comparable optical/UV and radio luminosities.) However, BAL RLQs are not as X-ray weak relative to non-BAL RLQs as are BAL RQQs relative to non-BAL RQQs. While some BAL RLQs have harder X-ray spectra than typical non-BAL RLQs, some have hardness ratios consistent with those of non-BAL RLQs, and there does not appear to be a correlation between X-ray weakness and spectral hardness, in contrast to the situation for BAL RQQs. RLQs are expected to have X-ray continuum contributions from both disk-corona and small-scale jet emission. While the entire X-ray continuum in BAL RLQs cannot be obscured to the same degree as in BAL RQQs, we calculate that the jet is likely partially covered in many BAL RLQs. We comment briefly on implications for geometries and source ages in BAL RLQs.Comment: 48 pages, 5 tables, 14 figures, accepted by Ap

Rectification by charging -- the physics of contact-induced current asymmetry in molecular conductors

We outline the qualitatively different physics behind charging-induced current asymmetries in molecular conductors operating in the weakly interacting self-consistent field (SCF) and the strongly interacting Coulomb Blockade (CB) regimes. A conductance asymmetry arises in SCF because of the unequal mean-field potentials that shift a closed-shell conducting level differently for positive and negative bias. A very different current asymmetry arises for CB due to the unequal number of open-shell excitation channels at opposite bias voltages. The CB regime, dominated by single charge effects, typically requires a computationally demanding many-electron or Fock space description. However, our analysis of molecular Coulomb Blockade measurements reveals that many novel signatures can be explained using a {{simpler}} orthodox model that involves an incoherent sum of Fock space excitations and {\it{hence treats the molecule as a metallic dot or an island}}. This also reduces the complexity of the Fock space description by just including various charge configurations only, thus partially underscoring the importance of electronic structure, while retaining the essence of the single charge nature of the transport process. We finally point out, however, that the inclusion of electronic structure and hence well-resolved Fock space excitations is crucial in some notable examples.Comment: 12 pages, 10 figure

Perspective Greenhouse gas mitigation by covers on livestock slurry tanks and lagoons?

Liquid manure (slurry) storage facilities are important point sources of atmospheric pollution. Being point sources, containment of gaseous emissions via improved storage conditions may be possible, and permeable surface covers (natural crusts and artificial covers) are increasingly recognized for their capacity to reduce various gaseous emissions. Microbial transformations in permeable surface covers include bacterial-methane oxidation, but this interface between nitrogen-rich slurry and the atmosphere is also an environment with intense nitrogen turnover that can lead to nitrous oxide emissions. Both methane and nitrous oxide are greenhouse gases, and strategies to reduce environmental impact of slurry stores must consider the total greenhouse gas balance. In this paper, greenhouse gas mitigation options for manure storages are discussed with reference mainly to practical storage conditions in Europe and North America

Zero dimensional area law in a gapless fermion system

The entanglement entropy of a gapless fermion subsystem coupled to a gapless bulk by a "weak link" is considered. It is demonstrated numerically that each independent weak link contributes an entropy proportional to lnL, where L is linear dimension of the subsystem.Comment: 6 pages, 11 figures; added 3d computatio

ІНФОРМАЦІЙНО-КОМУНІКАЦІЙНІ ТЕХНОЛОГІЇ АКТИВІЗАЦІЇ НАВЧАЛЬНОГО ПРОЦЕСУ У ВИЩИХ НАВЧАЛЬНИХ ЗАКЛАДАХ МНС УКРАЇНИ

The main points of the development of the informative – communicative technologies of the educational training activisation at the higher establishments of TES of Ukraine are presente in this article. The positive aspects of the informative- communicative technologies introducing in the educational process is analysed as wen. It is set that introduction and activation of information technologies in an educational process opens new possibilities both for a scientifically pedagogical personnel and for students (students) in the plan of complex perception of educational material. Modern pedagogical technologies foresee the increase of interest to the studies, and consequently and increase of level of progress of specialists of higher educational establishments of MINISTRY of emergency measures.Розглянуто особливості впровадження інформаційно-комунікаційних технологій, як чинників активізації навчального процесу у вищих навчальних закладах МНС України. Висвітлено специфіку застосування та позитивні аспекти впровадження інформаційно-комунікаційних технологій у навчальному процесі. Встановлено, що впровадження та активізація інформаційних технологій в навчальному процесі відкриває нові можливості як для науково-педагогічного персоналу, так і для курсантів (студентів) у плані комплексного сприйняття навчального матеріалу. Сучасні педагогічні технології передбачають підвищення інтересу до навчання, а отже і підвищення рівня успішності фахівців вищих навчальних закладів МНС

Stabilization and control system power sensitivity study

Stabilization and control system sensitivity to power-off failure rate studied by simulated missions using block power switchin

Dynamic Kerr Effect and Spectral Weight Transfer in the Manganites

We perform pump-probe Kerr spectroscopy in the colossally magnetoresistive manganite Pr0.67Ca0.33MnO3. Kerr effects uncover surface magnetic dynamics undetected by established methods based on reflectivity and optical spectral weight transfer. Our findings indicate the connection between spin and charge dynamics in the manganites may be weaker than previously thought. Additionally, important differences between this system and conventional ferromagnetic metals manifest as long-lived, magneto-optical coupling transients, which may be generic to all manganites.Comment: 12 text pages, 4 figure

Neutrino-nucleus reactions on ^{12}C and ^{16}O

Exclusive and inclusive $(\nu_\mu, \mu^-), (\nu_e, e^-)$ cross-sections and $\mu^-$-capture rates are calculated for ^{12}C and ^{16}O using the consistent random phase approximation (RPA) and pairing model. After a pairing correction is introduced to the RPA results the flux-averaged theoretical $(\nu_\mu, \mu^-), (\nu_e, e^-)$ cross-sections and $\mu^-$-capture rates in $^{12}$C are in good agreement with experiment. In particular when one takes into account the experimental error bars, the recently measured range of values for the $(\nu_\mu, \mu^-)$ cross-section is in agreement with the present theoretical results. Predictions of $(\nu_\mu, \mu^-)$ and $(\nu_e, e^-)$ cross-sections in ^{16}O are also presented.Comment: 13 pages, Revte

Micro-Field Assessment of Soil Erosion and Surface Runoff Using Mini Rainfall Simulator In Upper River Njoro Watershed in Kenya

Soil erosion and surface runoff are consequences of integration of several factors and processes within a catchment. The use of a rainfall simulator and run off plots provides a valuable research tool and are often used in soil erosion and surface runoff studies. Cheruiyot (1984) used this approach to study infiltration rates and sediment yield in Kiboko, Kenya. The present study used the same method but with a mini-rainfall simulator (Kamphorst, 1987) to study the effects of different land use treatments on soil loss and surface runoff