1,432 research outputs found
An Illustration of the Returns to Training Programmes: The Evaluation of the “Qualifying Contract" in France
We evaluate the labour market outcomes of a French training programme for youth, using a non-experimental sample of individuals who completed their studies (or dropped out) in 1998 and were observed until 2003. We use propensity score matching to estimate the impact of participation on three outcome variables: the net monthly wage, the monthly income and the probability of employment. We find a positive impact of participation on all three outcome variables. Non parametric robustness checks confirmed our results. We explain these results, which contrast with those of previous French studies, by the very strong training content of the programme.active labour market programmes, training programmes for youth, propensity score matching
Contact interaction in an unitary ultracold Fermi gas
An ultracold Fermi atomic gas at unitarity presents universal properties that
in the diluted limit can be well described by a contact interaction. By
employing a guide function with correct boundary conditions and making simple
modifications to the sampling procedure we are able to handle for the first
time a true contact interaction in a quantum Monte Carlo calculation. The
results are obtained with small variances. Our calculations for the Bertsch and
contact parameters are in excellent agreement with published experiments. The
possibility of using a more faithfully description of ultracold atomic gases
can help uncover features yet unknown of the ultracold atomic gases. In
addition, this work paves the way to perform quantum Monte Carlo calculations
for systems interacting with contact interactions, where in many cases the
description using potentials with finite effective range might not be accurate
Reemployment and substitution effects from increased activation: Evidence from times of crisis
Although activation services such as monitoring, training, or job subsidies have been shown to increase exits from unemployment, there is little comprehensive evidence about the effects of activation during recessions. Here we evaluate a large activation programme introduced in Portugal in 2012, a time of very high unemployment. This programme required specific unemployment benefit recipients to meet jobcentre caseworkers and then participate in active labour market policies. Our analysis draws on rich longitudinal data, the programme’s focus on those unemployed for at least six months, and fuzzy regression discontinuity methods. We find that, despite the weak labour market, the programme is very successful as it doubles the monthly reemployment probability. The results are robust to a number of checks, including a falsification exercise based on pre-programme data and an analysis of non-employment and income effects. Moreover, in a novel IV approach using information on all unemployed, we find no evidence of substitution effects such as decreased transitions to employment amongst non-eligible individuals.N/
Generalising the logistic map through the -product
We investigate a generalisation of the logistic map as (, )
where stands for a generalisation of the ordinary product, known as
-product [Borges, E.P. Physica A {\bf 340}, 95 (2004)]. The usual product,
and consequently the usual logistic map, is recovered in the limit ,
The tent map is also a particular case for . The
generalisation of this (and others) algebraic operator has been widely used
within nonextensive statistical mechanics context (see C. Tsallis, {\em
Introduction to Nonextensive Statistical Mechanics}, Springer, NY, 2009). We
focus the analysis for at the edge of chaos, particularly at the
first critical point , that depends on the value of . Bifurcation
diagrams, sensitivity to initial conditions, fractal dimension and rate of
entropy growth are evaluated at , and connections with
nonextensive statistical mechanics are explored.Comment: 12 pages, 23 figures, Dynamics Days South America. To be published in
Journal of Physics: Conference Series (JPCS - IOP
Zero-range Fermi gas along the BCS-BEC crossover
FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFAPEG - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE GOIÁSProperties of the ground state of an unpolarized ultracold Fermi gas along the BCS-BEC crossover are investigated by the variational and diffusion Monte Carlo methods. We apply the Wigner-Bethe-Peierls boundary condition in our calculations to avoid any bias from using an interatomic potential with finite effective range. Properties for several values of the scattering length are studied in the range -8 <= 1/ak(F) <= 4, including the unitary limit. The contact parameters as a function of scattering length are obtained by fitting the pair distribution functions for particles with different spins. The energies and contact parameters are in very good agreement with experimental data reported in the literature.100515FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFAPEG - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE GOIÁSFAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULOFAPEG - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE GOIÁS2016/17612-7Sem informaçãoThe authors acknowledge financial support from the Brazilian agencies Fundacao de Amparo a Pesquisa do Estado de Sao Paulo project (Proc. No. 2016/17612-7). Part of the computations was performed at the Centro Nacional de Processamento de Alto Desempenho em Sao Paulo. R.P. acknowledges the Fundacao de Amparo a Pesquisa do Estado de Goias and the computer resources of the Laboratorio de Computacao Cientifica - Universidade Federal de Goias. K.E.S. was supported by NSF Grant No. PHY-1404405
HEAT EXCHANGER NETWORK SYNTHESIS CONSIDERING CHANGING PHASE STREAMS
The Pinch Design Method was developed considering one-phase streams, with constant
specific heats (Cp) throughout streams temperature ranges. Its first stage, the determination
of utilities targets and pinch point (PP), is ruled by the number of streams, their temperatures
and MCp. But, for changing phase streams, the usual description of the Cp behavior by a
constant value can lead to errors in this stage and, hence, in the synthesis one. This work
proposes a procedure to deal with these streams and discusses its results through an example
involving multicomponent streams. First, bubble (BP) and dew (DP) points of the streams
are estimated. Then, changing phase streams are split into sub-streams, using BP and DP
as bounds. For each one, an effective Cp is estimated as the division of the enthalpy
change by the respective temperature difference. Results obtained show significant changes
on the PP, utilities targets and network proposed structure
Inibição in vitro de Colletotrichum Musae, agente da antracnose da banana, por meio de agentes vegetais, biológicos e químicos.
A antracnose ( Colletotrichum musae) destaca-se entre as doenças que afetam a banana. Com objetivo de controlar esse patógeno, avaliou--se, em ensaio in vitro, a eficiência dos extratos e óleos essenciais de: Lippia sidoides Cham., Caryophillus aromaticus L. e Eucalyptus citriodora Hook.; antagonistas, como o fungo Trichoderma sp., a levedura IA8 (UFC), e Bacillus subtilis; indutores de resistência, como o acibenzolar-S-metil, o fosfito de potássio e o ácido salicílico; e, ainda, antissépticos, como o hipoclorito de sódio (NaCLO), o dióxido de cloro e o sorbato de potássio. Os testes in vitro foram feitos em meio BDA + tetraciclina (50 µg.mL-1), nas concentrações de 5 mL, 10 mL, 15 mL, 20 mL, 25 mL e 30 mL de cada extrato; 0 µL, 25 µL, 50 µL e 100 µL de cada óleo; 0,05 g, 0,3 g e 300 µL dos indutores Bion®, ácido salicílico e fosfito de potássio, respectivamente; 0,1 g, 25 mL e 100 µL dos antissépticos sorbato de potássio, hipoclorito de sódio e dióxido de cloro, respectivamente, sendo a atividade antagônica determinada pelo método de culturas pareadas para Trichoderma sp. e pelo método do funil para a levedura IA8. A formulação com Bacillus subtilis foi testada na proporção de 100 µL/100 mL de BDA. Placas com apenas meio BDA ou o fungicida carbendazim (10 µL/100 mL) foram utilizadas como testemunhas. Os testes foram realizados à temperatura de 28°C ± 2°C e com fotoperíodo de 12h durante um período de sete dias. Em todos os casos estudados, os tratamentos foram distribuídos em delineamento inteiramente casualizado com cinco repetições. As médias foram comparadas pelo teste de Tukey a 5% de probabilidade. Em todas as concentrações testadas, os extratos e óleos essenciais de Lippia sidoides e Caryophillus aromaticus , assim como o ácido salicílico, o hipoclorito de sódio e o controle químico, foram efetivos, inibindo o patógeno. O fosfito de potássio e os antagonistas Trichoderma sp. e Bacilus subtilis também foram efetivos com reduções de 91,8%; 84,0% e 74,0%, respectivamente. Conclui-se que os extratos e óleos essenciais vegetais de Lippia sidoides e Caryophillus aromaticus , o ácido salicílico, o hipoclorito de sódio, fosfito e os antagonistas Trichoderma sp. e Bacillus subtilis poderão constituir-se em alternativa promissora ao controle do Colletotrichum musae.bitstream/item/69801/1/BPD12001.pd
- …