Detecting Compton Reflection and a Broad Iron Line in MCG-5-23-16 with the Rossi X-ray Timing Explorer

We report the detection with the Rossi X-ray Timing Explorer of a Compton reflection signature in the Seyfert galaxy MCG-5-23-16. RXTE also resolves the Fe K-alpha fluorescence line with FWHM ~48,000 km s^{-1}. This measurement provides the first independent confirmation of ASCA detections in Seyfert galaxies of broad Fe K-alpha lines that are thought to be the signature of emission from the inner regions of an accretion disk orbiting a black hole. Under the assumption that reflection arises from an isotropic source located above a neutral accretion disk, and using a theoretical model that accounts for the dependence of the reflected spectrum on inclination angle, we derive a 90% confidence range for the disk inclination of i = 50 to 81 degrees. The large inclination is consistent with that expected from the unified model for MCG-5-23-16 based on its Seyfert 1.9 classification. If we assume that the high-energy cutoff in the incident spectrum lies at energies larger than a few hundred keV, then the equivalent width of the Fe K-alpha line is much larger than predicted for the amount of reflection. This implies either an enhanced iron abundance, a covering factor of reflecting material > 0.5, or a cutoff in the incident spectrum at energies between ~60 and ~200 keV.Comment: Accepted for publication in ApJ, LaTeX. 14 pages including 3 figures, with 1 table as a separate postscript file. Typo corrected in abstrac

Hydrogen Balmer Line Broadening in Solar and Stellar Flares

The broadening of the hydrogen lines during flares is thought to result from increased charge (electron, proton) density in the flare chromosphere. However, disagreements between theory and modeling prescriptions have precluded an accurate diagnostic of the degree of ionization and compression resulting from flare heating in the chromosphere. To resolve this issue, we have incorporated the unified theory of electric pressure broadening of the hydrogen lines into the non-LTE radiative transfer code RH. This broadening prescription produces a much more realistic spectrum of the quiescent, A0 star Vega compared to the analytic approximations used as a damping parameter in the Voigt profiles. We test recent radiative-hydrodynamic (RHD) simulations of the atmospheric response to high nonthermal electron beam fluxes with the new broadening prescription and find that the Balmer lines are over-broadened at the densest times in the simulations. Adding many simultaneously heated and cooling model loops as a "multithread" model improves the agreement with the observations. We revisit the three-component phenomenological flare model of the YZ CMi Megaflare using recent and new RHD models. The evolution of the broadening, line flux ratios, and continuum flux ratios are well-reproduced by a multithread model with high-flux nonthermal electron beam heating, an extended decay phase model, and a "hot spot" atmosphere heated by an ultrarelativistic electron beam with reasonable filling factors: 0.1%, 1%, and 0.1% of the visible stellar hemisphere, respectively. The new modeling motivates future work to understand the origin of the extended gradual phase emission.Comment: 31 pages, 13 figures, 2 tables, accepted for publication in the Astrophysical Journa

Wave Scattering through Classically Chaotic Cavities in the Presence of Absorption: An Information-Theoretic Model

We propose an information-theoretic model for the transport of waves through a chaotic cavity in the presence of absorption. The entropy of the S-matrix statistical distribution is maximized, with the constraint $=\alpha n$: n is the dimensionality of S, and $0\leq \alpha \leq 1, \alpha =0(1)$ meaning complete (no) absorption. For strong absorption our result agrees with a number of analytical calculations already given in the literature. In that limit, the distribution of the individual (angular) transmission and reflection coefficients becomes exponential -Rayleigh statistics- even for n=1. For $n\gg 1$ Rayleigh statistics is attained even with no absorption; here we extend the study to $\alpha <1$. The model is compared with random-matrix-theory numerical simulations: it describes the problem very well for strong absorption, but fails for moderate and weak absorptions. Thus, in the latter regime, some important physical constraint is missing in the construction of the model.Comment: 4 pages, latex, 3 ps figure

Production of laccase by Botrytis cinerea and fermentation studies with strain F226

After induction, seven strains ofBotrytis cinerea released into the culture broth considerable amounts of laccase in a brief production time. The set-up of a suitable production process was studied with a selected strain in a 10-L fermenter. The optimum fermentation conditions were a 3% inoculum with a high degree of sporulation, a simple medium containing 20 g L−1 of glucose and 2 g L−1 of yeast extract at pH 3.5, 2 g L−1 gallic acid as inducer, added after 2 days of growth, an agitation speed of 300 rpm, an aeration rate of 1.2 vvm and a temperature of 24°C. By optimizing the culture conditions, the enzyme activity reached 28 U ml−1 in 5 days with a specific activity of 560 U mg−1 protein. The best procedure to obtain a suitable crude enzyme preparation was concentration of the supernatant medium to 10% of the initial volume by ultrafiltration, followed by a fractional precipitation with ethanol. The optimum pH and temperature for laccase activity were 5.5 and 40°C, respectively, with syringaldazine as the substrate

HCV Prevalence in Italy an Epidemiological, Observational, Cross-Sectional, Multicenter Study Participating Centers.

There is a lack of updated nationwide records regarding hepatitis C virus (HCV) infection among drug addicts in Italy. The prevalence and characteristics of HCV infection in a national sample of drug addicts in Italy were determined. Five hundred forty-three drug addicts (mean age 35.3 years, 85.1% males), selected from 25 Italian Centers for Substance Dependence were enrolled to be evaluated for anti-HCV, HCV-RNA, HCV genotype, HBV markers, anti-HDV, and anti-HIV during the period of April-November 2009. Anti-HCV prevalence was 63.9%. HCV-RNA was detected in 68.3% of patients positive for anti-HCV. Genotypes 1 and 3 prevailed (49.3% and 39.7%, respectively). However, 9.3% of the subjects had genotype 4, a rate over threefold higher than the one observed in 1996 among drug addicts in central Italy. Needle sharing was the strongest independent predictor of the likelihood to contract an HCV infection (OR 8.9; 95% CI: 5.0-16.0). Only 19.3% of subjects received antiviral treatment for HCV. The prevalence of HBsAg and HIV positivity was 2.8% and 3.1%, respectively. The pattern of HBV markers showed that nearly one-third of subjects had been vaccinated, while 42.3% were negative for any marker of HCV. The prevalence of HCV infection is high among drug addicts in Italy. The incidence of Genotype 4 is increasing and this may lead to the spreading of the disease to the general population in the near future. Efforts should be made to improve the rate of antiviral treatment for drug addicts with HCV infection and vaccination against hepatitis B

Actividades experimentais nas escolas através de uma interacção com a universidade

A forma como a ciência é ensinada nas escolas afecta profundamente a percepção que os estudantes têm do mundo que os rodeia e consequentemente a escolha de uma futura carreira nas ciências. Por outro lado, a abertura da escola à comunidade envolvente, proporciona as condições para a sua participação activa na vida escolar, assim como a promoção do sucesso escolar, através da formação integral dos alunos, dotando-os das competências científicas, tecnológicas e sócio-culturais necessárias a sólidas opções futuras. A química como uma ciência de cariz experimental oferece aos estudantes uma melhor compreensão dos conceitos teóricos leccionados. Este trabalho descreve actividades experimentais realizadas no âmbito de um intercâmbio entre a Escola Secundária/3 de Barcelinhos e o Departamento de Química. Os projectos desenvolvidos foram “Museu das Ciências” na disciplina de Área Projecto do 12º ano de escolaridade. A actividade A Ciência na investigação criminal foi baseada nas oficinas apresentadas no projecto Sentidos da Ciência [1]. Estas actividades experimentais executadas em colaboração entre as escolas e a universidade contribuem para uma maior motivação dos alunos, uma formação científica mais sólida e um conhecimento mais integrado

Reflection Symmetric Ballistic Microstructures: Quantum Transport Properties

We show that reflection symmetry has a strong influence on quantum transport properties. Using a random S-matrix theory approach, we derive the weak-localization correction, the magnitude of the conductance fluctuations, and the distribution of the conductance for three classes of reflection symmetry relevant for experimental ballistic microstructures. The S-matrix ensembles used fall within the general classification scheme introduced by Dyson, but because the conductance couples blocks of the S-matrix of different parity, the resulting conductance properties are highly non-trivial.Comment: 4 pages, includes 3 postscript figs, uses revte

Box-Behnken Design for optimization of Fenton-type reaction for water treatment using heterogeneous catalysts

Response Surface Methodology (RSM) was widely used in numerous research works for the optimization of different processes for liquid effluents treatment, since water pollution is one of the most serious environmental problem concerning human health and sustainability.1,2 RSM is a statistical technique applied to reduce the number of experiments, optimize and analyze the experimental independent parameters, that affect a process efficiency, and to generate a mathematical model which describes the process behavior.1,3 In this work, Box-Behnken design (BBD) was used for optimize the Fenton-type reaction using different bimetallic catalysts based in Rare Earth Elements with iron ion exchanged in zeolite (NaY) or a natural clay from Morocco. The effect of different experimental parameters such as, temperature, concentration of H2O2 and the heterogeneous catalysis used, was studied and optimized.We thank the Fundação para a Ciência e Tecnologia for financial support through Centre of Chemistry (UID/QUI/00686/2013 and UID/QUI/0686/2016) and BioTecNorte (operation NORTE-01-0145-FEDER-000004)info:eu-repo/semantics/publishedVersio