3,559 research outputs found
Acúmulo da biomassa em ipeca cultivada em casa-de-vegetação sob diferentes fontes e doses de matéria orgânica.
VIP: An Experiment to Search for a Violation of the Pauli Exclusion Principle
The Pauli Exclusion Principle is a basic principle of Quantum Mechanics, and
its validity has never been seriously challenged. However, given its
fundamental standing, it is very important to check it as thoroughly as
possible. Here we describe the VIP (VIolation of the Pauli exclusion principle)
experiment, an improved version of the Ramberg and Snow experiment (E. Ramberg
and G. Snow, {\it Phys. Lett. B} {\bf 238}, 438 (1990)); VIP has just completed
the installation at the Gran Sasso underground laboratory, and aims to test the
Pauli Exclusion Principle for electrons with unprecedented accuracy, down to
. We report preliminary experimental
results and briefly discuss some of the implications of a possible violation.Comment: Plenary talk presented by E. Milotti at Meson 2006, Cracow, 9-13 June
200
New experimental limit on Pauli Exclusion Principle violation by electrons (the VIP experiment)
The Pauli exclusion principle (PEP) represents one of the basic principles of
modern physics and, even if there are no compelling reasons to doubt its
validity, it still spurs a lively debate, because an intuitive, elementary
explanation is still missing, and because of its unique stand among the basic
symmetries of physics. A new limit on the probability that PEP is violated by
electrons was estabilished by the VIP (VIolation of the Pauli exclusion
principle) Collaboration, using the method of searching for PEP forbidden
atomic transitions in copper. The preliminary value, {1/2}\beta^{2} \textless
4.5\times 10^{-28}, represents an improvement of about two orders of magnitude
of the previous limit. The goal of VIP is to push this limit at the level of
.Comment: submitted to Journal of Physics: Conference Series, by the Institute
of Physic
Searches for the Violation of Pauli Exclusion Principle at LNGS in VIP(-2) experiment
The VIP (Violation of Pauli exclusion principle) experiment and its follow-up
experiment VIP-2 at the Laboratori Nazionali del Gran Sasso (LNGS) search for
X-rays from Cu atomic states that are prohibited by the Pauli Exclusion
Principle (PEP). The candidate events, if they exist, will originate from the
transition of a orbit electron to the ground state which is already
occupied by two electrons. The present limit on the probability for PEP
violation for electron is 4.7 set by the VIP experiment. With
upgraded detectors for high precision X-ray spectroscopy, the VIP-2 experiment
will improve the sensitivity by two orders of magnitude.Comment: 5 pages, 3 figures, 1 table. Conference proceedings for oral
presentation at TAUP 2015, Torin
High sensitivity tests of the Pauli Exclusion Principle with VIP2
The Pauli Exclusion Principle is one of the most fundamental rules of nature
and represents a pillar of modern physics. According to many observations the
Pauli Exclusion Principle must be extremely well fulfilled. Nevertheless,
numerous experimental investigations were performed to search for a small
violation of this principle. The VIP experiment at the Gran Sasso underground
laboratory searched for Pauli-forbidden X-ray transitions in copper atoms using
the Ramberg-Snow method and obtained the best limit so far. The follow-up
experiment VIP2 is designed to reach even higher sensitivity. It aims to
improve the limit by VIP by orders of magnitude. The experimental method,
comparison of different PEP tests based on different assumptions and the
developments for VIP2 are presented.Comment: 6 pages, 3 figures, Proceedings DISCRETE2014 Conferenc
Produção vegetal e de óleo essencial de boldo pequeno em função de fontes de adubos orgânicos.
A aplicação de fertilizantes orgânicos, em plantas medicinais e aromáticas, normalmente modifica positivamente a produção vegetal e de óleo essencial. Neste contexto, tendo por fim avaliar a resposta de plantas de Plectranthus neochilus Schltr., cultivadas com diferentes fontes de adubos orgânicos, o presente trabalho estudou a produção de biomassa, teor, rendimento e composição química do óleo essencial. As mudas, após a aclimatização, foram transplantadas para vasos de dez litros, acondicionados em casa de vegetação. O experimento foi constituído por quatro tratamentos e quatro repetições (16 parcelas), sendo cada parcela composta por cinco vasos. Os tratamentos foram: ausência de adubo orgânico (testemunha); aplicação de 60 t ha-1 de esterco bovino; 30 t ha-1 de esterco avícola; 60 t ha-1 de composto orgânico. Aos 120 dias de cultivo, as plantas foram colhidas e uma parte das folhas frescas foi destinada à extração do óleo essencial. O restante do material vegetal foi seco em estufa, até atingir peso constante, para a determinação da biomassa seca. As análises químicas do óleo foram realizadas por cromatografia gasosa (CG-DIC e CG-EM). As fontes de adubo orgânico testadas promoveram diferenças entre os tratamentos em relação à produção de biomassa, rendimento e composição do óleo essencial de P. neochilus. A utilização de diferentes fertilizantes orgânicos não modificou o teor de óleo volátil
Beyond quantum mechanics? Hunting the 'impossible' atoms (Pauli Exclusion Principle violation and spontaneous collapse of the wave function at test)
The development of mathematically complete and consistent models solving the
so-called "measurement problem", strongly renewed the interest of the
scientific community for the foundations of quantum mechanics, among these the
Dynamical Reduction Models posses the unique characteristic to be
experimentally testable. In the first part of the paper an upper limit on the
reduction rate parameter of such models will be obtained, based on the analysis
of the X-ray spectrum emitted by an isolated slab of germanium and measured by
the IGEX experiment.
The second part of the paper is devoted to present the results of the VIP
(Violation of the Pauli exclusion principle) experiment and to describe its
recent upgrade. The VIP experiment established a limit on the probability that
the Pauli Exclusion Principle (PEP) is violated by electrons, using the very
clean method of searching for PEP forbidden atomic transitions in copper
Planting time for maximization of yield of vinegar plant calyx (Hibiscus sabdariffa L.)
Objetivou-se avaliar a produtividade de cálices de Hibiscus sabdariffa L., planta medicinal, em quatro épocas de plantio em Lavras M.G. Os tratamentos foram quatro épocas de plantio (18 de outubro; 15 de novembro; 18 de dezembro de 2001 e 15 de janeiro de 2002) e realizada uma colheita quando praticamente não existiam cálices em desenvolvimento, quase no final do ciclo da planta. Foram considerados os números de cálices por planta, as fitomassas frescas e secas dos cálices e a qualidade. Concluiu-se que a época de plantio influenciou o rendimento por planta e as fitomassas frescas e secas dos cálices, diferindo entre si pelo teste de Tukey a 5%. No plantio de outubro, houve maior rendimento (2.522 kg/ha), com produção de 5,24 vezes a mais em relação ao plantio do mês de janeiro (481 kg/ha). Os plantios nos meses de novembro e dezembro tiveram produções de 1.695 e 1.093 kg.ha-1 de cálices secos, respectivamente, e em relação ao mês de janeiro, a produção foi 3,52 e 2,27 vezes a mais.Deve-se realizar a colheita assim que os cálices estiverem maduros, a fim de preservar a qualidade
Particle acoustic detection in gravitational wave aluminum resonant antennas
The results on cosmic rays detected by the gravitational antenna NAUTILUS
have motivated an experiment (RAP) based on a suspended cylindrical bar, which
is made of the same aluminum alloy as NAUTILUS and is exposed to a high energy
electron beam. Mechanical vibrations originate from the local thermal expansion
caused by warming up due to the energy lost by particles crossing the material.
The aim of the experiment is to measure the amplitude of the fundamental
longitudinal vibration at different temperatures. We report on the results
obtained down to a temperature of about 4 K, which agree at the level of about
10% with the predictions of the model describing the underlying physical
process.Comment: RAP experiment, 16 pages, 7 figure
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