8,746 research outputs found
Simulation study on light ions identification methods for carbon beams from 95 to 400 MeV/A
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
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
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 . The
comparison between the values of extracted from existing data on the
Debye-Waller factor for various metal surfaces and the 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
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
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
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
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
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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