8,746 research outputs found

    Simulation study on light ions identification methods for carbon beams from 95 to 400 MeV/A

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    Monte Carlo simulations have been performed in order to evaluate the efficiencies of several light ions identification techniques. The detection system was composed with layers of scintillating material to measure either the deposited energy or the time-of-flight of ions produced by nuclear reactions between 12C projectiles and a PMMA target. Well known techniques such as (DELTA) E--Range, (DELTA) E--E--ToF and (DELTA)E--E are presented and their particle identification efficiencies are compared one to another regarding the generated charge and mass of the particle to be identified. The simulations allowed to change the beam energy matching the ones proposed in an hadron therapy facility, namely from 95 to 400 MeV/A

    Imaging and mapping the impact of clouds on skyglow with all-sky photometry

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    Artificial skyglow is constantly growing on a global scale, with potential ecological consequences ranging up to affecting biodiversity. To understand these consequences, worldwide mapping of skyglow for all weather conditions is urgently required. In particular, the amplification of skyglow by clouds needs to be studied, as clouds can extend the reach of skyglow into remote areas not affected by light pollution on clear nights. Here we use commercial digital single lens reflex cameras with fisheye lenses for all-sky photometry. We track the reach of skyglow from a peri-urban into a remote area on a clear and a partly cloudy night by performing transects from the Spanish town of Balaguer towards Montsec Astronomical Park. From one single all-sky image, we extract zenith luminance, horizontal and scalar illuminance. While zenith luminance reaches near-natural levels at 5km distance from the town on the clear night, similar levels are only reached at 27km on the partly cloudy night. Our results show the dramatic increase of the reach of skyglow even for moderate cloud coverage at this site. The powerful and easy-to-use method promises to be widely applicable for studies of ecological light pollution on a global scale also by non-specialists in photometry.Comment: 13 pages, 7 figure

    The electron-phonon coupling strength at metal surfaces directly determined from the Helium atom scattering Debye-Waller factor

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    A new quantum-theoretical derivation of the elastic and inelastic scattering probability of He atoms from a metal surface, where the energy and momentum exchange with the phonon gas can only occur through the mediation of the surface free-electron density, shows that the Debye-Waller exponent is directly proportional to the electron-phonon mass coupling constant λ\lambda. The comparison between the values of λ\lambda extracted from existing data on the Debye-Waller factor for various metal surfaces and the λ\lambda values known from literature indicates a substantial agreement, which opens the possibility of directly extracting the electron-phonon coupling strength in quasi-2D conducting systems from the temperature or incident energy dependence of the elastic Helium atom scattering intensities.Comment: 14 pages, 2 figures, 1 tabl

    The Baltic banking system in the enlarged European Union: The effect of the financial crisis on efficiency

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    The main objective of this study is to analyse the evolution of banking efficiency in the Baltic countries after their accession to the EU and during the financial crisis, and to check whether there are significant differences between these countries as a consequence of their particular characteristics. To that end, we have estimated the evolution of cost and profit efficiency in the Baltic countries in the context of the enlarged EU during the period 2000-2013 using Bayesian stochastic frontier models. Our results show the greater robustness of Estonian banking in terms of profits during the financial crisis in comparison to their neighbours. Additionally, Baltic banking has recovered its profit efficiencies very quickly after the financial crisis. However, cost efficiency is still at low levels in line with the other European countries

    Hurst Coefficient in long time series of population size: Model for two plant populations with different reproductive strategies

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    Can the fractal dimension of fluctuations in population size be used to estimate extinction risk? The problem with estimating this fractal dimension is that the lengths of the time series are usually too short for conclusive results. This study answered this question with long time series data obtained from an iterative competition model. This model produces competitive extinction at different perturbation intensities for two different germination strategies: germination of all seeds vs. dormancy in half the seeds. This provided long time series of 900 years and different extinction risks. The results support the hypothesis for the effectiveness of the Hurst coefficient for estimating extinction risk

    Double di ffential fragmentation cross sections measurements of 95 MeV/u 12C on thin targets for hadrontherapy

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    During therapeutic treatment with heavy ions like carbon, the beam undergoes nuclear fragmentation and secondary light charged particles, in particular protons and alpha particles, are produced. To estimate the dose deposited into the tumors and the surrounding healthy tissues, an accurate prediction on the fluences of these secondary fragments is necessary. Nowadays, a very limited set of double di ffential carbon fragmentation cross sections are being measured in the energy range used in hadrontherapy (40 to 400 MeV/u). Therefore, new measurements are performed to determine the double di ffential cross section of carbon on di erent thin targets. This work describes the experimental results of an experiment performed on May 2011 at GANIL. The double di ffential cross sections and the angular distributions of secondary fragments produced in the 12C fragmentation at 95 MeV/u on thin targets (C, CH2, Al, Al2O3, Ti and PMMA) have been measured. The experimental setup will be precisely described, the systematic error study will be explained and all the experimental data will be presented.Comment: Submitted to PR

    Pemahaman dan Sikap Guru Wanita Tentang Informasi Balita Sehat dan Pola Pengasuhan Anak di Kota Kupang

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    This research aims to know the difference levels of knowledge and attitude of female teachers toward the examination of the information content of under- five's health and the children taking care pattern through interpersonal communication and mass media. This research was conducted by using pre-experimental design. In this experiment, the multistage sampling was used to determine the number of respondents. So there was 28 respondents. So there was 28 respondents which conducted to be tested. The pretest and posttest was used was used to know how far the levels of knowledge and attitude of the female teachers in achieving the information of the under-five's health and the children taking care pattern in Kupang Municipal. The research result shows that the levels and attitude of female teachers positively changed after conveying the information of the under-five's health and children taking care pattern through interpersonal communication and mass media. Besides that, there was the difference level of score of knowledge and attitude of female teachers in the information content which consists of giving nutrient to the children (PMA) and the actual pattern of taking care (PPA) of them

    Efficient methane production from lipid-rich wastewater in high-rate anaerobic treatment

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    In this work, high rate anaerobic mineralization of a synthetic dairy effluent containing 50% COD as oleic acid was accomplished in two reactors operated in parallel. The anaerobic reactors were able to accommodate organic loading rates up to 21 kg COD m-3 day-1, HRT of 9 hours, attaining 99% of soluble COD removal efficiency and methane yield higher than 70%. Long chain fatty acids (LCFA) accumulated inside the reactor only during the last two phases of operation and palmitic acid was the main LCFA quantified, representing 40–100% of the total LCFA detected. High specific methanogenic activity was determined at the end of the operation, in the presence of acetate (1346±87 mg COD-CH4 gVS-1 day-1) and H2/CO2 (3582±309 mg COD-CH4 gVS-1 day-1). The specific activity of the anaerobic consortia present in the reactors during the operation was also determined, and a maximum value of 1170±170 mg COD-CH4 gVS-1 day-1 was obtained. The high performance accomplished in the reactors was a consequence of the discontinuous acclimation strategy applied, that produced an anaerobic microbial community specialized in the efficient mineralization of LCFA.Fundação para a Ciência e Tecnologia (FCT) projecto FAT-METHANE (POCTI/CTA/46328/2002), bolsa de doutoramento SFRH/BD/24256/200
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