Inelaticity in hadron-nucleus collisions from emulsion chamber studies

The inelasticity of hadron-carbon nucleus collisions in the energy region exceeding 100 TeV is estimated from the carbon-emulsion chamber data at Pamirs to be $= 0.65\pm 0.08$. When combined with the recently presented data on hadron-lead nucleus collisions taken at the same energy range it results in the $K\sim A^{0.086}$ mass number dependence of inelasticity. The evaluated partial inelasticity for secondary ($\nu > 1$) interactions, $K_{\nu >1} \simeq 0.2$, suggests that the second and higher interactions of the excited hadron inside the nucleus proceed with only slight energy losses.Comment: LaTeX file and 5 LaTeX files with figures, 11 pages altogether. Thoroughly rewritten and modified, one figure addded one removed. To be published in Phys. Rev.

Electroweak Corrections to the Top Quark Decay

We have calculated the one-loop electroweak corrections to the decay t-> bW+, including the counterterm for the CKM matrix elements V(tb). Previous calculations used an incorrect delta V(tb) that led to a gauge dependent amplitude. However, since the contribution stemming from delta V(tb) is small, those calculations only underestimate the width by roughly one part in 10^5.Comment: 7 pages, 2 figure

Higgs-photon associated production at eeˉe\bar{e} colliders

We present complete analytical expressions for the amplitudes of the process $e\bar{e}\rightarrow H\gamma$. The calculation is performed using nonlinear gauges, which significantly simplifies both the actual analytical calculation and the check of its gauge invariance. After comparing our results with a previous numerical calculation, we extend the range of Higgs masses and center of mass energies to those appropriate to LEP 200 and a future linear collider.Comment: To appear in PRD. 18 pages latex, uses REVTEX; 5 postscript figure

Phenols, essential oils and carotenoids of Rosa canina from Tunisia and their antioxidant activities

The antioxidant activity of leaf extracts of Rosa canina from diverse localities of Tunisia were evaluated by ABTS and DPPH methods, whereas in those of essential oils and carotenoids extracts such activity was determined only by the ABTS method. Total phenols determined by the Folin method revealed that at Aindraham, samples showed a great variability of phenol content in contrast to those from Feija. After chemical analysis of the essential oils by gas chromatography (GC) and gas chromatography coupled to mass spectra (GC-MS), revealed that the oils of Feija were predominantly composed of palmitic acid, vitispirane, linoleic acid, lauric acid, myristic acid and phytol acetate, while in those samples from Aindraham predominated vitispirane, palmitic acid, linoleic acid and phytol acetate. Higher concentrations of beta-carotene and lycopene were found in the samples from Aindraham after determination by high performance liquid chromatography (HPLC). All samples possess antioxidant activity, nevertheless much more significant in phenol extracts in contrast to the carotenoid extracts, which possess the lowest activity

The space density distribution of galaxies in the absolute magnitude - rotation velocity plane: a volume-complete Tully-Fisher relation from CALIFA stellar kinematics

The space density distribution of galaxies in the absolute magnitude - rotation velocity plane: a volume-complete Tully-Fisher relation from CALIFA stellar kinematicsComment: Accepted to A&

Shrinkage and mechanical performance of geopolymeric mortars based on calcined Tunisian clay

"Special Issue for International Congress on Materials & Structural Stability, Rabat, Morocco, 27-30 November 2013"Infrastructure rehabilitation represents a multitrillion dollar opportunity for the construction industry. Since the majority of the existent infrastructures are Portland cement concrete based this means that concrete infrastructure rehabilitation is a hot issue to be dealt with. Geopolymers are novel inorganic binders with high potential to replace Portland cement based ones. Geopolymerization is a complex chemical process evolving various aluminosilicate oxides with silicates under highly alkaline conditions, yielding polymeric units, similar to those of an aluminosilicate glass. So far very few studies in the geopolymer field have addressed the rehabilitation of deteriorated concrete structures. This paper discloses some results of an investigation concerning the development geopolymeric repair mortars based on a calcined Tunisian clay. The results show that Tunisian calcined clay based mortars have hydration products with typical geopolymeric phases. Results also show that the geopolymeric mortar shows a high unrestrained shrinkage behavior and that its modulus of elasticity is below the threshold required for this repair mortar

On the Milnor formula in arbitrary characteristic

The Milnor formula $\mu=2\delta-r+1$ relates the Milnor number $\mu$, the double point number $\delta$ and the number $r$ of branches of a plane curve singularity. It holds over the fields of characteristic zero. Melle and Wall based on a result by Deligne proved the inequality $\mu\geq 2\delta-r+1$ in arbitrary characteristic and showed that the equality $\mu=2\delta-r+1$ characterizes the singularities with no wild vanishing cycles. In this note we give an account of results on the Milnor formula in characteristic $p$. It holds if the plane singularity is Newton non-degenerate (Boubakri et al. Rev. Mat. Complut. (2010) 25) or if $p$ is greater than the intersection number of the singularity with its generic polar (Nguyen H.D., Annales de l'Institut Fourier, Tome 66 (5) (2016)). Then we improve our result on the Milnor number of irreducible singularities (Bull. London Math. Soc. 48 (2016)). Our considerations are based on the properties of polars of plane singularities in characteristic $p$.Comment: 18 page

Avaliação da aptidão agroecológica das terras de paisagens montanhosas da Região Serrana do Estado do Rio de Janeiro.

A avaliação do potencial agrícola fornece informações relevantes para subsidiar o planejamento do uso das terras. O objetivo deste trabalho foi aplicar um conjunto de procedimentos para a avaliação do potencial agroecológico das terras em uma área montanhosa na região Serrana do Estado do Rio de Janeiro, ocupada por pequenos produtores rurais, em regime de agricultura familiar. Foram considerados, na avaliação agroecológica, informações de solos, geomorfologia, litologia, rede de drenagem, estrutura fundiária, uso e cobertura vegetal, declividade e unidades ambientais, extraídas de estudos anteriores. Essas informações foram incorporadas a um banco de dados desenvolvido no SIG e associadas com informações socioeconômicas de pluviosidade e áreas de proteção legal e, a partir dessas informações, avaliou-se a aptidão agroecológica por unidades ambientais delimitadas. O modelo de aptidão agroecológica considerado envolve a indicação de uso, manejo e sugestão de alternativas sustentáveis de utilização das terras com menor índice de agressão ao meio ambiente, de forma a incrementar a qualidade ambiental sem descuidar da integridade das terras. A metodologia usada foi adequada ao planejamento de áreas de relevo movimentado, pois, onde se identificou a ocorrência de compartimentos mais frágeis e problemáticos em função dos solos, da declividade, da suscetibilidade aos processos erosivos e ao maior grau de fragilidade ambiental, estes se encaixaram nas classes de aptidão inapta, restrita, preservação ambiental ou áreas de recomposição de matas.bitstream/item/146012/1/BPD-254-Avaliacao-Aptidao-Serrana-RJ.pd

The nature of LINER galaxies: Ubiquitous hot old stars and rare accreting black holes

Galaxies, which often contain ionised gas, sometimes also exhibit a so-called low-ionisation nuclear emission line region (LINER). For 30 years this was attributed to a central mass-accreting supermassive black hole (AGN) of low luminosity, making LINER galaxies the largest AGN-sub-population, dominating in numbers over higher luminosity Seyfert galaxies and quasars. This, however, poses a serious problem. While the inferred energy balance is plausible, many LINERs clearly do not contain any other independent signatures of an AGN. Using integral field spectroscopic data from the CALIFA survey, we aim at comparing the observed radial surface brightness profiles with what is expected from illumination by an AGN. Essential for this analysis is a proper extraction of emission-lines, especially weak lines such as the Balmer Hb line which is superposed on an absorption trough. To accomplish this, we use the GANDALF code which simultaneously fits the underlying stellar continuum and emission lines. We show for 48 galaxies with LINER-like emission, that the radial emission-line surface brightness profiles are inconsistent with ionisation by a central point-source and hence cannot be due to an AGN alone. The most probable explanation for the excess LINER-like emission is ionisation by evolved stars during the short but very hot and energetic phase known as post-AGB. This leads us to an entirely new interpretation. Post-AGB stars are ubiquitous and their ionising effect should be potentially observable in every galaxy with gas present and stars older than ~1 Gyr, unless a stronger radiation field from young hot stars or an AGN outshines them. This means that galaxies with LINER-like emission are in fact not a class defined by a property, but rather by the absence of a property. It also explains why LINER emission is observed mostly in massive galaxies with old stars and little star formation.Comment: 8 pages, 7 figure

Estratégias para a obtenção de ácido lático via processo fermentativo utilizando planejamento experimental.

Este trabalho teve como objetivo principal a produção de ácido lático (AL) por via fermentativa utilizando a bactéria Klebsiella pneumoniae e glicerol (subproduto da indústria de biodiesel) como fonte de carbono. Primeiramente, foram realizados experimentos com base em um planejamento fatorial completo 23 com triplicatas no ponto central para avaliação dos fatores (concentração de inóculo, pH e temperatura) de maior influência sobre o crescimento celular e produção de AL por 48 horas. O planejamento preliminar serviu de base para realização de novos experimentos a luz de um planejamento fatorial central composto rotacional para avaliação da concentração de inóculo e pH, em fermentações conduzidas a 37 °C por 72 horas. Em ambos os casos, a avaliação da significância dos efeitos foi realizada com base em ANOVA com nível de confiança de 95% (p = 0,05). Para o primeiro planejamento fatorial, o diagrama de Pareto para efeitos normalizados com relação à produção de AL indicou somente a temperatura era uma variável significativa ao final das 48 horas de fermentação, com curvas de nível indicando uma tendência de maior produção do AL em temperatura e pH elevado e pouca influência da concentração celular não foi significativa. Para o plano central composto rotacional, o diagrama de Pareto para efeitos normalizados com relação à produção de AL indicou que a concentração de inóculo e o pH são significativos para a produção de AL e satisfazem a hipótese estatística dentro da faixa avaliada. De acordo com o gráfico de superfície e sua respectiva curva de nível verifica-se que um ponto de máximo consumo de glicerol para o plano central (pH=9,5) composto rotacional, correspondente à máxima produção do AL (3,03 g/L). A partir desse experimento, foi possível verificar quais parâmetros influenciam de forma mais significativa na produção do AL e usá-los futuramente em experimento no biorreator. As condições ótimas que maximizaram a produção de AL e o consumo do glicerol foram: pH 9,5, temperatura de 37 °C e 14,9 g/L de concentração de inóculo. Estes resultados mostram que o glicerol pode ser utilizado para obtenção eficiente de produtos químicos de alto valor agregado, como ácido lático.Evento virtual para a troca e difusão de conhecimentos. Trabalho: ConBraPA#003