56,561 research outputs found
Dynamic radiation force of acoustic waves on solid elastic spheres
The present study concerns the dynamic radiation force on solid elastic
spheres exerted by a plane wave with two frequencies (bichromatic wave)
considering the nonlinearity of the fluid. Our approach is based on solving the
wave scattering for the sphere in the quasilinear approximation within the
preshock wave range. The dynamic radiation force is then obtained by
integrating the component of the momentum flux tensor at the difference of the
primary frequencies over the boundary of the sphere. Results reveal that
effects of the nonlinearity of the fluid plays a major role in dynamic
radiation force leading it to a parametric amplification regime. The developed
theory is used to calculate the dynamic radiation force on three different
solid spheres (aluminium, silver, and tungsten). Resonances are observed in the
spectrum of the force on the spheres. They have larger amplitude and better
shape than resonances present in static radiation force.Comment: 9 pages, 4 figures, to appear in Physical Review
O feijão-caupi para processamento industrial e exportação.
O feijão-caupi (Vigna unguiculada (L.) Walp.) é uma leguminosa amplamente adaptada, versátil e nutritiva, devido ao seu conteúdo protéico e energético, sendo cultivado em diversas partes do mundo, proporcionando emprego e renda para milhares de pessoas.bitstream/item/64593/1/Caupi-agrosoft.pdfDisponível também nos seguintes endereços: http://www.portaldoagronegocio.com.br/index.php?p=texto&&idT=1136; http://www.maxpress.com.br/noticia-boxsa.asp?TIPO=PA&SQINF=292871; http://www.zoonews.com.br/noticias2/noticia.php?idnoticia=126209 ; http://www.paginarural.com.br/artigos_detalhes.php?id=1594; Comunique-se O Portal da comunicação; Agrosoft Brasil
The pion mass dependence of the nucleon form-factors of the energy momentum tensor in the chiral quark-soliton model
The nucleon form factors of the energy-momentum tensor are studied in the
large-Nc limit in the framework of the chiral quark-soliton model for model
parameters that simulate physical situations in which pions are heavy. This
allows for a direct comparison to lattice QCD results.Comment: 17 pages, 12 figure
Using mixed methods for analysing culture : The Cultural Capital and Social Exclusion project
This paper discusses the use of material generated in a mixed method investigation into cultural tastes and practices, conducted in Britain from 2003 to 2006, which employed a survey, focus groups and household interviews. The study analysed the patterning of cultural life across a number of fields, enhancing the empirical and methodological template provided by Bourdieu’s Distinction. Here we discuss criticisms of Bourdieu emerging from subsequent studies of class, culture and taste, outline the arguments related to the use of mixed methods and present illustrative results from the analysis of these different types of data. We discuss how the combination of quantitative and qualitative methods informed our analysis of cultural life in contemporary Britain. No single method was able to shed light on all aspects of our inquiry, lending support to the view that mixing methods is the most productive strategy for the investigation of complex social phenomena
Supertubes in reduced holonomy manifolds
We show that the supertube configurations exist in all supersymmetric type
IIA backgrounds which are purely geometrical and which have, at least, one flat
direction. In other words, they exist in any spacetime of the form R^{1,1} x
M_8, with M_8 any of the usual reduced holonomy manifolds. These generalised
supertubes preserve 1/4 of the supersymmetries preserved by the choice of the
manifold M_8. We also support this picture with the construction of their
corresponding family of IIA supergravity backgrounds preserving from 1/4 to
1/32 of the total supercharges.Comment: 20 page
Qualidade fisiológica de sementes de milheto armazenadas.
A cultura do trigo tem grande importância comercial, contudo ainda são escassos, resultados científicos referente ao uso de herbicidas nesta cultura. Em termos de mercado é notório a pequena quantidade de produtos recomendados para o controle de plantas daninhas em pós-emergência desta cultura, e limitadas são as informações sobre os efeitos que estes causam. Neste contexto, o objetivo do presente trabalho foi avaliar o desempenho agronômico e a qualidade fisiológica das sementes sob o efeito da aplicação de doses crescentes de Metsulfuron methyl (Ally) em estádios de desenvolvimento diferentes, assumindo que altas doses de Ally podem ser utilizadas em dois estádios de desenvolvimento e supondo que o emprego de altas doses em combinação com o estádio de desenvolvimento possa afetar a planta. Com este intuito foi conduzido um ensaio a campo, no Município de Marialva - PR, com delineamento em blocos completos casualizados, com quatro repetições, em que os tratamentos foram compostos por cinco doses do herbicida Ally O; 30; 60; 90; 120g i.a. ha; aplicadas em dois estádios da cultura: 4 e 10.4. As variáveis avaliadas foram: produtividade, massa de mil sementes, germinação e vigor (pela primeira contagem do teste de germinação). A partir dos resultados obtidos, pode-se inferir que: o herbicida Ally aplicado em altas doses no período reprodutivo tende a diminuir a produtividade (P<O, 1 O) e o vigor (P<0,03) de suas sementes, porém aplicações no vegetativo não apresentam efeitos significativos ai, 5 e 10% de probabilidade, com relação aos caracteres observados aqui.Edição dos Resumos do XVI Congresso Brasileiro de Sementes, Curitiba, PR, set. 2003
Hadronic Entropy Enhancement and Low Density QGP
Recent studies show that for central collisions the rising of the incident
energy from AGS to RHIC decreases the value of the chemical potential in the
Hadron-QGP phase diagram. Thus, the formation of QGP at RHIC energies in
central collisions may be expected to occur at very small values of the
chemical potential. Using many different relativistic mean-field hadronic
models (RMF) at this regime we show that the critical temperature for the
Hadron-QGP transition is hadronic model independent. We have traced back the
reason for this and conclude that it comes from the fact that the QGP entropy
is much larger than the hadronic entropy obtained in all the RMF models. We
also find that almost all of these models present a strong entropy enhancement
in the hadronic sector coming from the baryonic phase transition to a
nucleon-antinucleon plasma. This result is in agreement with the recent data
obtained in the STAR collaboration at RHIC where it was found a rich
proton-antiproton matter
- …