1,380 research outputs found

    Multivariate analysis of the water quality variation in the Serra da Estrela (Portugal) Natural Park as a consequence of road deicing with salt.

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    The concentration of some anions (Cl, F, NO3, and SO4), cations (Na, K, Ca, and Mg), pH and conductivity was determined in seven sampling points in the Serra da Estrela Mountains (Portugal) to verify if the application of road deicing with salt provokes impact in the water quality. Multivariate chemometric data analysis techniques of clustering and factor analysis were used. Preliminary analysis shows an overall conductivity increase in late spring and a decrease in late summer. A strong association between sodium chloride and the conductivity was observed by cluster analysis. Factor analysis supports the previous results and shows that the variation of the concentration of sodium chloride is the main source of the variance of the data along the year. In conclusion, the spreading of salt during the winter creates a local and seasonal impact on the water quality

    Integral elastic, electronic-state, ionization, and total cross sections for electron scattering with furfural

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    8 págs.; 2 figs.; 2 tabs.We report absolute experimental integral cross sections (ICSs) for electron impact excitation of bands of electronic-states in furfural, for incident electron energies in the range 20-250 eV. Wherever possible, those results are compared to corresponding excitation cross sections in the structurally similar species furan, as previously reported by da Costa et al. [Phys. Rev. A 85, 062706 (2012)] and Regeta and Allan [Phys. Rev. A 91, 012707 (2015)]. Generally, very good agreement is found. In addition, ICSs calculated with our independent atom model (IAM) with screening corrected additivity rule (SCAR) formalism, extended to account for interference (I) terms that arise due to the multi-centre nature of the scattering problem, are also reported. The sum of those ICSs gives the IAM-SCAR+I total cross section for electron-furfural scattering. Where possible, those calculated IAM-SCAR+I ICS results are compared against corresponding results from the present measurements with an acceptable level of accord being obtained. Similarly, but only for the band I and band II excited electronic states, we also present results from our Schwinger multichannel method with pseudopotentials calculations. Those results are found to be in good qualitative accord with the present experimental ICSs. Finally, with a view to assembling a complete cross section data base for furfural, some binary-encounter-Bethe-level total ionization cross sections for this collision system are presented.D.B.J. thanks the Australian Research Council (ARC) for financial support provided through a Discovery Early Career Research Award, while M.J.B. also thanks the ARC for their support. M.J.B. acknowledges the Brazilian agency CNPq for his “Special Visiting Professor” position at the Federal University of Juiz de Fora. G.G. acknowledges partial financial support from the Spanish Ministry MINECO (Project No. FIS2012-31230) and the European Union COST Action No. CM1301 (CELINA). Finally R.F.C., M.T.doN.V, M.H.F.B, and M.A.P.L. also acknowledge support from CNPq, while M.T.doN.V. thanks FAPESPPeer Reviewe

    Levantamento das patologias e monitorização do Arco-Cruzeiro da Igreja da Misericórdia de Aveiro

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    O estado de conservação das construções tradicionais motiva para um crescente interesse na recuperação e manutenção do património construído. Antes de mais, é importante obter uma visão geral da evolução temporal das construções permitindo assim a caracterização dos diversos aspectos estruturais e construtivos. Este trabalho foi desenvolvido com o objectivo de estudar as patologias associadas à nave principal da Igreja da Misericórdia de Aveiro e em particular as patologias associadas ao Arco-Cruzeiro que se encontra no interior desta, com o intuito de se estabelecer a melhor estratégia de monitorização dos danos estruturais a aplicar. Como resultado desta análise foi proposto e implementado um plano de monitorização, com o desenvolvimento de meios de instrumentação, que permitem monitorizar o comportamento estrutural do arco, de forma não intrusiva, garantindo a reversibilidade e a eventual futura extensão da instrumentação. Foi ainda desenvolvido um modelo numérico em elementos finitos que serviu de apoio à interpretação das causas dos danos estruturais encontrados

    A mega-analysis of expression quantitative trait loci (eQTL) provides insight into the regulatory architecture of gene expression variation in liver

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    TS was an awardee of the Roche Internships for Scientific Exchange (RiSE) Programme. The work has been supported in part by institutional funds (TG77) of the Institute of Human Genetics Regensburg and by a grant from the Helmut Ecker Foundation (Ingolstadt, Germany) to BHFW (No. 05/17).Peer reviewedPublisher PD

    Ligand-Free Palladium-Catalyzed Oxyarylation of Dihydronaphthal­enes and Chromenequinone with o-Iodophenols and 3-Iodolawsone in PEG-400: An Efficient Synthesis of 5-Carbapterocarpans and Pterocarpanquinones

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    Dihydronaphthalenes were oxyarylated with o-iodophenols, in PEG-400 at 140 or 170 °C, leading regio- and stereoselectively to 5-carbapterocarpans. By using Pd(OAc)2 (5–10 mol%) as precatalyst and Ag2CO3 (1.1 equiv) as base (conditions A), products were obtained in good to excellent chemical yields, in 5–30 minutes, irrespective of the pattern of substitution the starting materials. Alternatively, when p-hydroxyacetophenone oxime derived palladacycle (1 mol%) was used as precatalyst, and dicyclohexylamine (2 equiv) was used as base (silver-free, conditions B), the corresponding adducts were obtained in moderate to good yields, in 0.5 to 4 hours. Finally, the oxyarylation of dihydronaphthalenes­ and chromenquinone with o-iodophenols and 3-iodolawsone in PEG-400 under conditions A led regio- and stereoselectively to the formation of carbapterocarpanquinones and pterocarpanquinones in moderate yield.Financial support from Brazilian agencies CAPES-DGU (Project 200/09), CNPq, FAPERJ and UFRJ are acknowledged. Spanish MICINN (Projects PHB2008-0037-PC, CTQ2007-62771/BQU, CTQ2010-20387, Consolider INGENIO 2010 CSD2007-00006), FEDER, Generalitat Valenciana (Project PROMETEO/2009/038), and the University of Alicante are acknowledged

    The electron-furfural scattering dynamics for 63 energetically open electronic states

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    14 págs.; 15 figs.We report on integral-, momentum transfer- and differential cross sections for elastic and electronically inelastic electron collisions with furfural (CHO). The calculations were performed with two different theoretical methodologies, the Schwinger multichannel method with pseudopotentials (SMCPP) and the independent atom method with screening corrected additivity rule (IAM-SCAR) that now incorporates a further interference (I) term. The SMCPP with N energetically open electronic states (N) at either the static-exchange (N ch-SE) or the static-exchange-plus-polarisation (N ch-SEP) approximation was employed to calculate the scattering amplitudes at impact energies lying between 5 eV and 50 eV, using a channel coupling scheme that ranges from the 1ch-SEP up to the 63ch-SE level of approximation depending on the energy considered. For elastic scattering, we found very good overall agreement at higher energies among our SMCPP cross sections, our IAM-SCAR+I cross sections and the experimental data for furan (a molecule that differs from furfural only by the substitution of a hydrogen atom in furan with an aldehyde functional group). This is a good indication that our elastic cross sections are converged with respect to the multichannel coupling effect for most of the investigated intermediate energies. However, although the present application represents the most sophisticated calculation performed with the SMCPP method thus far, the inelastic cross sections, even for the low lying energy states, are still not completely converged for intermediate and higher energies. We discuss possible reasons leading to this discrepancy and point out what further steps need to be undertaken in order to improve the agreement between the calculated and measured cross sections. ©2016 AIP Publishing LLCR.F.d.C., M.C.A.L., M.H.F.B., M.T.d.N.V., and M.A.P.L. acknowledge support from the Brazilian agency Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq). M.T.d.N.V. acknowledges support from Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP). D.B.J. thanks the Australian Research Council (ARC) for financial support provided through a Discovery Early Career Researcher Award. M.J.B. thanks the ARC for some financial support and also thanks CNPq for his “Special Visiting Professor” award at the Federal University of Juiz de Fora. G.G. thanks the Spanish Ministerio de Economia y Competitividad under Project No. FIS2012- 31230 and the European Union COST Action No. CM1301 for funding.Peer Reviewe

    Theoretical and experimental differential cross sections for electron impact excitation of the electronic bands of furfural

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    13 págs.; 8 figs.; 6 tabs.We report results from a joint experimental and theoretical investigation into electron scattering from the important industrial species furfural (CHO). Specifically, differential cross sections (DCSs) have been measured and calculated for the electron-impact excitation of the electronic states of CHO. The measurements were carried out at energies in the range 20-40 eV, and for scattered-electron angles between 10°and 90°. The energy resolution of those experiments was typically ∼80 meV. Corresponding Schwinger multichannel method with pseudo-potential calculations, for energies between 6-50 eV and with and without Born-closure, were also performed for a sub-set of the excited electronic-states that were accessed in the measurements. Those calculations were undertaken at the static exchange plus polarisation-level using a minimum orbital basis for single configuration interaction (MOB-SCI) approach. Agreement between the measured and calculated DCSs was qualitatively quite good, although to obtain quantitative accord, the theory would need to incorporate even more channels into the MOB-SCI. The role of multichannel coupling on the computed electronic-state DCSs is also explored in some detail. ©2016 AIP Publishing LLCR.F.C.N. thanks CNPq (Brazil) and the Science Without Borders Programme for opportunities to study abroad. D.B.J. thanks the Australian Research Council (ARC) for financial support provided through a Discovery Early Career Research Award, while M.J.B. also thanks the ARC for their support. M.J.B. and M.C.A.L. acknowledge the Brazilian agencies CNPq and FAPEMIG. P.L.-V. acknowledges the Portuguese Foundation for Science and Technology (FCTMEC) through Grant Nos. PTDC/FIS-ATO/1832/2012 and UIO/FIS/00068/2013. G.G. acknowledges partial financial support from the Spanish Ministry MINECO (Project No. FIS2012-31230) and the European Union COST Action No. CM1301 (CELINA). Finally, R.F.d.C., M.T.d.N.V., M.H.F.B., and M.A.P.L. acknowledge support from the Brazilian agency CNPq and M.T.d.N.V. also thanks FAPESP.Peer Reviewe

    The Five Factor Model of personality and evaluation of drug consumption risk

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    The problem of evaluating an individual's risk of drug consumption and misuse is highly important. An online survey methodology was employed to collect data including Big Five personality traits (NEO-FFI-R), impulsivity (BIS-11), sensation seeking (ImpSS), and demographic information. The data set contained information on the consumption of 18 central nervous system psychoactive drugs. Correlation analysis demonstrated the existence of groups of drugs with strongly correlated consumption patterns. Three correlation pleiades were identified, named by the central drug in the pleiade: ecstasy, heroin, and benzodiazepines pleiades. An exhaustive search was performed to select the most effective subset of input features and data mining methods to classify users and non-users for each drug and pleiad. A number of classification methods were employed (decision tree, random forest, kk-nearest neighbors, linear discriminant analysis, Gaussian mixture, probability density function estimation, logistic regression and na{\"i}ve Bayes) and the most effective classifier was selected for each drug. The quality of classification was surprisingly high with sensitivity and specificity (evaluated by leave-one-out cross-validation) being greater than 70\% for almost all classification tasks. The best results with sensitivity and specificity being greater than 75\% were achieved for cannabis, crack, ecstasy, legal highs, LSD, and volatile substance abuse (VSA).Comment: Significantly extended report with 67 pages, 27 tables, 21 figure
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