264 research outputs found
CHANGES IN PRECIPITATION EXTREMES IN BRAZIL (PARANÁ RIVER BASIN)
Made available in DSpace on 2018-12-11T17:00:33Z (GMT). No. of bitstreams: 0
Previous issue date: 2016-02-01This research was aimed at addressing aspects related to variation in the amount of precipitation during the period from 1986 to 2011 in the Paraná River Hydrographical Basin, Brazil, for 32 meteorological stations using 11 climate indices created by the ETCCDI (Expert Team, ET, on Climate Change Detection and Indices, ETCCDI). The daily rainfall data were organized in spreadsheets, which were subjected to an intense quality control and an accurate historical research. For each pluviometric index, we have estimated the trends and the statistical significant of the slopes have been calculated. The results confirm that an increase in total precipitation in almost all analyzed stations was registered, and the extreme precipitations were the main contributors to such additions. In fact, the significant increase in total annual rainfall in north-central sector of the basin are related to higher rates of heavy rain, mainly above 95th percentile, as well as to the highest event of rainfall above 10 mm. Instead the northern part of the region, showed declining trends of extreme rainfall, caused mainly by the reduction in the rainfall occurrences over 95th percentile. In order to evaluate the impact that the increasing extreme rainfall may cause in large urban centers, we have investigated the data of two municipalities (Curitiba, PR and Goiânia, GO-Brazil), where the positive trend can cause inconvenience to the population (floods and inundations) suggesting, at least, the need of implementation of more effective urban planning for the future.Programa de Pós-Graduação em Geografia Universidade Estadual Paulista - UNESP Instituto de Geociências e Ciências Exatas, Avenida 24 A, número 1515Dipartimento di Scienze della Terra Università di Torino, Via Valperga Caluso 35Centro di Ricerca sui Rischi Naturali in Ambiente Montano e Collinare (NatRisk), via Leonardo da Vinci 4Programa de Pós-Graduação em Geografia Universidade Estadual Paulista - UNESP Instituto de Geociências e Ciências Exatas, Avenida 24 A, número 151
Axion interpretation of the PVLAS data?
The PVLAS collaboration has recently reported the observation of a rotation
of the polarization plane of light propagating through a transverse static
magnetic field. Such an effect can arise from the production of a light, m_A ~
meV, pseudoscalar coupled to two photons with coupling strength g_{A\gamma} ~
5x10^{-6} GeV^{-1}. Here, we review these experimental findings, discuss how
astrophysical and helioscope bounds on this coupling can be evaded, and
emphasize some experimental proposals to test the scenario.Comment: 4 pages, 1 figure, jpconf.cls, talk presented at the ninth
International Conference on Topics in Astroparticle and Underground Physics,
TAUP 2005, Zaragoza, Spain, September 10-14, 200
From parental-fetal attachment to a parent-infant relationship: a systematic review about prenatal protective and risk factors
Developing an attachment to an unborn child is considered a milestone in the future parents’ developmental trajectory. Furthermore, the quality of the parent-fetus relationship is related to the quality of the postnatal parent-infant relationship. We have aimed to provide an overview of the recent findings highlighting factors that can influence parental prenatal attachment and the postpartum parent-child relationship. PubMed and PsycINFO were systematically explored looking for longitudinal studies, published from 2005 to 2016, reporting clearly the prenatal attachment measures used. We found 28 studies heterogeneous for sampling techniques, sample size and periods of assessment. Studies considered a broad range of individual, relational and contextual variables as potential risk or protective factors, but no one has of yet evaluated the interaction between them. The main focus remains on mothers. From these studies emerged conflicting and difficult to generalize results, and this does not facilitate the understanding of the phenomenon investigated. The current literature needs to be integrated with more longitudinal studies using comparable tools and periods of observation, at either a normal or at risk sample. There is also need for additional studies focused on fathers and couples, and considering the effects of the fetal behavior on the development of prenatal attachment
Ultrafast Resonant Polarization Interferometry: Towards the First Direct Detection of Vacuum Polarization
Vacuum polarization, an effect predicted nearly 70 years ago, is still yet to
be directly detected despite significant experimental effort. Previous attempts
have made use of large liquid-helium cooled electromagnets which inadvertently
generate spurious signals that mask the desired signal. We present a novel
approach for the ultra-sensitive detection of optical birefringence that can be
usefully applied to a laboratory detection of vacuum polarization. The new
technique has a predicted birefringence measurement sensitivity of in a 1 second measurement. When combined with the extreme
polarizing fields achievable in this design we predict that a vacuum
polarization signal will be seen in a measurement of just a few days in
duration.Comment: 9 pages, 2 figures. submitted to PR
Suspension of the fiber mode-cleaner launcher and measurement of the high extinction-ratio (10^{-9}) ellipsometer for the Q & A experiment
The Q & A experiment, first proposed and started in 1994, provides a feasible
way of exploring the quantum vacuum through the detection of vacuum
birefringence effect generated by QED loop diagram and the detection of the
polarization rotation effect generated by photon-interacting (pseudo-)scalar
particles. Three main parts of the experiment are: (1) Optics System (including
associated Electronic System) based on a suspended 3.5-m high finesse
Fabry-Perot cavity, (2) Ellipsometer using ultra-high extinction-ratio
polarizer and analyzer, and (3) Magnetic Field Modulation System for generating
the birefringence and the polarization rotation effect. In 2002, the Q & A
experiment achieved the Phase I sensitivity goal. During Phase II, we set (i)
to improve the control system of the cavity mirrors for suppressing the
relative motion noise, (ii) to enhance the birefringence signal by setting-up a
60-cm long 2.3 T transverse permanent magnet rotatable to 10 rev/s, (iii) to
reduce geometrical noise by inserting a polarization-maintaining optical fiber
(PM fiber) as a mode cleaner, and (iv) to use ultra-high extinction-ratio
(10^{-9}) polarizer and analyzer for ellipsometry. Here we report on (iii) &
(iv); specifically, we present the properties of the PM-fiber mode-cleaner, the
transfer function of its suspension system, and the result of our measurement
of high extinction-ratio polarizer and analyzer.Comment: 8 pages, 6 figures, presented in the 6th Edoardo Amaldi Conference on
Gravitational Waves, Okinawa, Japan, June 2005, and accepted by "Journal of
Physics: Conference Series". Modifications from version 2 were made based on
the referees' comments on figures. Ref. [31] were update
- …