15,067 research outputs found
O que é vinho de qualidade?
bitstream/item/123314/1/bonvivant-v14-n155-p42-dez-2013.pdfPublicado também no informativo A Vindima, v. 6, n. 57, p. 4, nov. 2013
Linear scaling computation of the Fock matrix. IX. Parallel computation of the Coulomb matrix
We present parallelization of a quantum-chemical tree-code [J. Chem. Phys.
{\bf 106}, 5526 (1997)] for linear scaling computation of the Coulomb matrix.
Equal time partition [J. Chem. Phys. {\bf 118}, 9128 (2003)] is used to load
balance computation of the Coulomb matrix. Equal time partition is a
measurement based algorithm for domain decomposition that exploits small
variation of the density between self-consistent-field cycles to achieve load
balance. Efficiency of the equal time partition is illustrated by several tests
involving both finite and periodic systems. It is found that equal time
partition is able to deliver 91 -- 98 % efficiency with 128 processors in the
most time consuming part of the Coulomb matrix calculation. The current
parallel quantum chemical tree code is able to deliver 63 -- 81% overall
efficiency on 128 processors with fine grained parallelism (less than two heavy
atoms per processor).Comment: 7 pages, 6 figure
Towards the Genealogy of Borderline Personality Disorder
Introdução: A perturbação borderline da
personalidade surge na ausência de uma
categoria para classificar pessoas que se encontravam entre o diagnóstico de neurose e
psicose e tem, desde o seu nascimento, sofrido modificações na sua definição e aplicação
clínica.
Objectivos: Este artigo tem por objectivo traçar a genealogia da perturbação borderline
da personalidade de modo a ensaiar hipóteses
para o surgimento desta categoria diagnóstica.
Métodos: Com base numa revisão da literatura, foi efectuada uma leitura crítica da evolução da categoria borderline na psiquiatria.
Resultados: A evolução do conceito pode ser
definida ao longo de três fases: desde o final
do XIX ao início do século XX são usadas múltiplas terminologias e o diagnóstico é heterogéneo; de 1960 a 1980 surge o conceito de organização borderline da personalidade e a sua
sistematização segundo a teoria psicanalítica;
desde 1980 até à actualidade ocorre a entrada
na DSM III e a homogeneização do diagnóstico sob a égide da biopsiquiatria. Os limites
entre as diferentes fases do conceito são fluídos e dependem das condições socio-políticas
associadas. Para o nascimento da doença em
análise são ensaiadas várias hipóteses: criação
de novos sujeitos-psíquicos, melhor acesso à
saúde mental e identificação da doença, governamentalidade biopolítica, identificação
de comportamentos anteriormente não considerados patológicos, descontinuidade social,
nova expressão de sofrimento e contágio social.
Conclusão: A perturbação borderline da personalidade resulta de práticas, representações,
interacções sociais e modos de subjectificação,
onde ocorre uma nova relação entre as ideias
de corpo e identidade.info:eu-repo/semantics/publishedVersio
Entanglement Swapping: Entangling Atoms That Never Interacted
In this paper we discuss four different proposals of entangling atomic states
of particles which have never interacted. The experimental realization proposed
makes use of the interaction of Rydberg atoms with a micromaser cavity prepared
in either a coherent state or in a superposition of the zero and one field Fock
states. We consider atoms in either a three-level cascade or lambda
configurationComment: 17 pages and 2 figure
Comparison of Four Space Propulsion Methods for Reducing Transfer Times of Manned Mars Mission
We assess the possibility of reducing the travel time of a manned mission to
Mars by examining four different propulsion methods, and keeping the mass at
departure under 2,500 tonnes, for a fixed architecture. We evaluated
representative systems of three different state of the art technologies
(chemical, nuclear thermal, and electric), and one advance technology, the
"Pure Electro-Magnetic Thrust" (PEMT) concept (proposed by Rubbia). A mission
architecture mostly based on the Design Reference Architecture 5.0 is assumed
in order to estimate the mass budget, that influences the performance of the
propulsion system. Pareto curves of the duration of the mission and time of
flight versus mass of mission are drawn. We conclude that the ion engine
technology, combined with the classical chemical engine, yields the shortest
mission times for this architecture with the lowest mass, and that chemical
propulsion alone is the best to minimise travel time. The results obtained
using the PEMT suggest that it could be a more suitable solution for farther
destinations than Mars.Comment: Change in title, abstract and presentation so to clarify the main
results. 14 pages, 7 figures and 2 table
Enological potential of grapes produced in different periods in a tropical region of Northeast Brazil.
The Lower-Middle São Francisco river Valley is a new vitivinicultural region located in northeast Brazil, between 8° and 9° S latitude. ln this region 11's possible to have two-three harvests a year, mainly due to an annual average temperature of 26.4°C, with about 567 mm of rainfall between January and April, altitude of 350 m above sea leveI and use of drip irrigation. There is';a. continuous vegetative developrnent and grapevine growth occurs throughout the whole year. Grap~ composition can vary strongly according to harvest time of the year due to different climatic conditions. Wineries harvest grapes for winemaking between May and December. The aim of t4~~ study was to compare Tempranillo grapes composition harvested in two periods: June and December 2007, to best understand the influence ofharvest date on grape quality.Resumo
- …