24,249 research outputs found
Quantum statistical correlations in thermal field theories: boundary effective theory
We show that the one-loop effective action at finite temperature for a scalar
field with quartic interaction has the same renormalized expression as at zero
temperature if written in terms of a certain classical field , and if
we trade free propagators at zero temperature for their finite-temperature
counterparts. The result follows if we write the partition function as an
integral over field eigenstates (boundary fields) of the density matrix element
in the functional Schr\"{o}dinger field-representation, and perform a
semiclassical expansion in two steps: first, we integrate around the
saddle-point for fixed boundary fields, which is the classical field ,
a functional of the boundary fields; then, we perform a saddle-point
integration over the boundary fields, whose correlations characterize the
thermal properties of the system. This procedure provides a
dimensionally-reduced effective theory for the thermal system. We calculate the
two-point correlation as an example.Comment: 13 pages, 1 figur
Teratoma Sacrococcígeo:Caso Clínico
O teratoma sacrococcígeo, embora
raro, é a neoplasia mais frequentemente
diagnosticada no período
neonatal. O diagnóstico é geralmente
estabelecido após o nascimento, apesar
do uso da ultrassonografia obstétrica
permitir um número crescente de
sinalizações pré -natais. O principal
diagnóstico diferencial é o mielomeningocelo.
A monitorização de marcadores
tumorais sugestivos da presença de
células malignas de um tumor do saco
vitelino associado, tal como a alfa-
-fetoproteína, e a ressecção precoce
do tumor são recomendáveis.
Apresenta -se o caso clínico de
um recém -nascido do sexo feminino a
quem foi detectado ao nascimento uma
massa sacrococcígea. A ressonância
magnética nuclear admitiu tratar -se de
um teratoma sacrococcígeo e o valor
de alfa -fetoproteína era normal para
a idade da doente. Foi realizada ressecção
total do tumor com remoção do
cóccix e confi rmado o diagnóstico em
estudo anátomo -patológico. A reavaliação
posterior da criança revelou um
valor decrescente da alfa -fetoproteína,
ausência de défi ces motores e um bom
aspecto cosmético.
A apresentação deste caso clínico
pretende realçar a importância do diagnóstico
precoce, fundamental para a
abordagem terapêutica adequada e melhor
prognóstico
Teste de tetrazólio em trigo: vigor e classes de sementes.
Edição Especial contendo os Anais do XVIII Congresso Brasileiro de Sementes, Florianópolis, set. 2013
Improving the Knowledge on Seismogenic Sources in the Lower Tagus Valley for Seismic Hazard Purposes
The Lower Tagus Valley, that includes the metropolitan area of Lisbon, has been struck by several earthquakes which produced significant material damage and loss of lives. Their exact location remains unknown. Our goal is to shed some light into the seismogenic sources in the area using seismic reflection and geological data. In areas with no seismic coverage, potential-field data interpretation was carried out. Seismicity was overlaid to the potential seismogenic structures and high-resolution data was acquired in order to confirm which structures have been active into the Quaternary. Three major fault-zones affecting the Neogene were identified: V. F. Xira, Samora-Alcochete and Pinhal Novo. For the first fault, strong evidences suggest it is active. The other two fault-zones and other structures previously unknown can be correlated with several epicentres. Empirical relationships between maximum moment magnitude and fault area indicate that MW > 6.5 earthquakes can be expected for the larger structures
Adequação de metodologia para avaliação da viabilidade de sementes de trigo pelo teste de tetrazólio.
Edição Especial contendo os Anais do XVIII Congresso Brasileiro de Sementes, Florianópolis, set. 2013
Challenges and opportunities for livestock production in natural pastures: the case of Brazilian Pampa Biome.
Insights about destination brand: Madeira case study
The concept of brand as known today is passed through various (re) definitions over the years. Initially, the brand was associated with house products, but with the evolution of society has come to represent industrial products, people, values, and services. Nowadays due to the great offer of tourist destinations, brands also represent countries, cities, and regions. This type of brands, result from maturation and of the coverage of the functionality of the same. Thus, the tourist brands or place brands, come from the necessity to value the places through its unique characteristics, boosting the visit of tourists and the sustainability of the destination. The island of Madeira is a typical tourist destination, which stands out from the competition through its heritage, in terms of culture and patrimony. With its economy based on tourism and to measure the importance of the Brand, an interview was conducted at one of the main actors in this area, specifically the Regional Tourism Director of the Autonomous Region of Madeira. In addition we have interview 118 tourists during July and August 2017 at Madeira
airport.info:eu-repo/semantics/publishedVersio
Constraint on the chemical potentials of hydrogen and proton in recombination
In this paper, we revisit the hydrogen recombination history from a novel
perspective: the evolution of chemical potentials. We derive expressions for
the chemical potentials, which depend on the thermal bath temperature and the
ionization degree of the universe. Our main finding reveals a constraint
between the chemical potentials of hydrogen and proton at when
the free electron fraction is . Furthermore, we present
important data on the chemical potentials during recombination, highlighting
the differences between the predictions of the Peebles' and CosmoRec code
solutions. Finally, we discuss a particular case related to the chemical
potential of hydrogen.Comment: 5 pages, 3 figure
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