268 research outputs found
Environmental Consciousness among Graduation Students: Comparing Ukraine with Portugal
The present study was undertaken to evaluate and compare the environmental consciousness in Ukraine and
Portugal and also to measure what is the impact of having this concept in the curricula of formal schooling,
the sex and the age of the person. To obtain micro data, as it is usual in the literature, we send a self-administered questionnaires by email to students of the Institute of Finance, Economics and Management of Sumy State University (Ukraine, Sumy) and to students of the Scholl of Economics and Management of the University of Porto (Portugal, Porto) from which we obtained 172 complete responses 104 from Porto and 68 from Sumy. We compute the Index of Environmental Consciousness and the Index of Schooling and we estimate a regression model using Weighted Linear Model from which were are able to conclude that 1) Portugal students have a significantly higher Environmental Consciousness than ones from Ukraine, 2) introducing the concept of Environmental Consciousness in the curricula of formal schooling has not significant impact on the Environmental Consciousness of students, 3) female people have a significantly higher Environmental Consciousness than the male ones and 4) age has a positive but not significant impact on the Environmental Consciousness of the person. Using bootstrapping we investigate whether the assumption of a normal distribution of the error term would not cause catastrophic impact on estimators’ t-statistics test and we concluded that results maintain valid. We observe that the majority of people, 80.1%, have environmental consciousness
Chaotic Motion Around Prolate Deformed Bodies
The motion of particles in the field of forces associated to an axially
symmetric attraction center modeled by a monopolar term plus a prolate
quadrupole deformation is studied using Poincare surface of sections and
Lyapunov characteristic numbers. We find chaotic motion for certain values of
the parameters, and that the instability of the orbits increases when the
quadrupole parameter increases. A general relativistic analogue is briefly
discussed.Comment: RevTEX, 7 eps figures, To appear in Phys Rev E (March 2001
Tunneling spectroscopy in the magnetic superconductor TmNi2B2C
We present new measurements about the tunneling conductance in the
borocarbide superconductor TmNiBC. The results show a very good
agreement with weak coupling BCS theory, without any lifetime broadening
parameter, over the whole sample surface. We detect no particular change of the
tunneling spectroscopy below 1.5K, when both the antiferromagnetic (AF) phase
and the superconducting order coexist.Comment: Submitted to Phys. Rev. B, Rapid Communication
Phonon-mediated anisotropic superconductivity in the Y and Lu nickel borocarbides
We present scanning tunneling spectroscopy and microscopy measurements at low
temperatures in the borocarbide materials RNi2B2C (R=Y, Lu). The characteristic
strong coupling structure due to the pairing interaction is unambiguously
resolved in the superconducting density of states. It is located at the
superconducting gap plus the energy corresponding to a phonon mode identified
in previous neutron scattering experiments. These measurements also show that
this mode is coupled to the electrons through a highly anisotropic
electron-phonon interaction originated by a nesting feature of the Fermi
surface. Our experiments, from which we can extract a large electron-phonon
coupling parameter lambda (between 0.5 and 0.8), demonstrate that this
anisotropic electron-phonon coupling has an essential contribution to the
pairing interaction. The tunneling spectra show an anisotropic s-wave
superconducting gap function.Comment: 5 pages, 3 figure
Biological properties of natural dyes
El propósito del presente trabajo es evaluar el aumento en el uso de colorantes naturales en la industria alimentaria
y la posibilidad de desarrollar nuevos medicamentos gracias a sus diversas propiedades biológicas. La presente
revisión aborda las principales actividades biológicas observadas en los carotenoides y las antocianinas y pone
énfasis en el amplio uso del extracto de achiote o bija (Bixa orellana L.) y de la curcumina (Curcuma longa) en estas
actividades.The aim of the present work is to evaluate the increase uses of natural colorants in the nourishing industry and in the
promising of new medicines due its several biological properties. In this review the main biological activities observed
in the carotenóids and the anthocyianins are boarded, with emphasis in the wide use of the urucum‘s extract from Bixa
orellana L.) and of curcumin from Curcuma longa in these activities
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