88 research outputs found
Von Neumann's Quantization of General Relativity
Von Neumann's procedure is applied for quantization of General Relativity. We
quantize the initial data of dynamical variables at the Planck epoch, where the
Hubble parameter coincides with the Planck mass. These initial data are defined
via the Fock simplex in the tangent Minkowskian space-time and the Dirac
conformal interval. The Einstein cosmological principle is applied for the
average of the spatial metric determinant logarithm over the spatial volume of
the visible Universe. We derive the splitting of the general coordinate
transformations into the diffeomorphisms (as the object of the second N\"other
theorem) and the initial data transformations (as objects of the first N\"other
theorem). Following von Neumann, we suppose that the vacuum state is a quantum
ensemble. The vacuum state is degenerated with respect to quantum numbers of
non-vacuum states with the distribution function that yields the Casimir effect
in gravidynamics in analogy to the one in electrodynamics. The generation
functional of the perturbation theory in gravidynamics is given as a solution
of the quantum energy constraint. We discuss the region of applicability of
gravidynamics and its possible predictions for explanation of the modern
observational and experimental data.Comment: 14 pages, updated version with extended discussio
Emanation Study of Gas Radon on the Ancient Cuexcomate Geyser in Puebla City, Mexico
Radon measurements were collected over a period of nine months in the area of the ancient Cuexcomate geyser, in Puebla City. For measuring radon, the passive method of nuclear tracks in solids was used, using polycarbonate CR-39 as radiation sensitive material. Radon concentrations varied in strong anti-correlation with the rainfall intensity. And are lower compared to other locations, in concordance with the stratigraphic composition, as travertine and deposits of volcanic origin, corresponding to the geyser chemical composition and the active environment in the north part of the Trans-Mexican Volcanic Belt with an andesitic and basalt composition
Electrified BPS Giants: BPS configurations on Giant Gravitons with Static Electric Field
We consider D3-brane action in the maximally supersymmetric type IIB
plane-wave background. Upon fixing the light-cone gauge, we obtain the
light-cone Hamiltonian which is manifestly supersymmetric. The 1/2 BPS
solutions of this theory (solutions which preserve 16 supercharges) are either
of the form of spherical three branes, the giant gravitons, or zero size point
like branes. We then construct specific classes of 1/4 BPS solutions of this
theory in which static electric field on the brane is turned on. These
solutions are deformations about either of the two 1/2 BPS solutions. In
particular, we study in some detail 1/4 BPS configurations with electric dipole
on the three sphere giant, i.e. BIons on the giant gravitons, which we hence
call BIGGons. We also study BPS configurations corresponding to turning on a
background uniform constant electric field. As a result of this background
electric field the three sphere giant is deformed to squashed sphere, while the
zero size point like branes turn into circular or straight fundamental strings
in the plane-wave background, with their tension equal to the background
electric field.Comment: 32 pages, 1 eps figure; v2: Presentation of derivation of light-cone
Hamiltonian improved, Refs adde
The Benefits of Physical Activity on Climacteric Women
As the population ages, there is a need of developing ways to prevent or revert the deleterious effects of aging, especially in climacteric women who suffer with the problems caused by hormonal changes. Exercise is a nonmedicated intervention that can be applied on that population. The benefits of physical activity can positively change body composition, increase levels of muscular strength, balance, and functional capacity. Strength training, aerobic exercise, whole body vibration, and aquatic exercises are some of the modalities that health professionals can prescript to these individuals. Although there are many studies about these exercises, a technique called blood flow restriction is emerging as an alternative to high load exercises but with the same benefits
Generalizations of Nonlinear and Supersymmetric Classical Electrodynamics
We first write down a very general description of nonlinear classical
electrodynamics, making use of generalized constitutive equations and
constitutive tensors. Our approach includes non-Lagrangian as well as
Lagrangian theories, allows for electromagnetic fields in the widest possible
variety of media (anisotropic, piroelectric, chiral and ferromagnetic), and
accommodates the incorporation of nonlocal effects. We formulate
electric-magnetic duality in terms of the constitutive tensors. We then propose
a supersymmetric version of the general constitutive equations, in a superfield
approach.Comment: 15 pages, based on the presentation by G. A. Goldin at QTS
Aplicações sequenciais de herbicidas em cana-planta como estratégia de manejo para controle de plantas daninhas.
A implantação dos canaviais associada ao uso sequencial de herbicidas é indicada para controle de plantas daninhas quando estão estabelecidas em elevadas densidades populacionais. Neste escopo, o objetivo do trabalho foi estudar o controle de cordas-de-viola e capins a partir de aplicações de herbicidas, iniciadas no pré-plantio (com e sem incorporação), complementadas após plantio (préemergência total) e no fechamento do canavial pelo dossel das plantas (?quebra-lombo?). O experimento foi conduzido em cana-planta, cv RB98-5476, e em latossolo vermelho de textura argilosa. O delineamento experimental foi em blocos casualizados com 10 tratamentos em quatro repetições. Os tratamentos foram constituídos pela testemunha com e sem plantas daninhas, ametryn (1920 g ha-1) + flumioxazin (160 g ha-1), ametryn (1440 g ha-1) + flumioxazin (120 g ha-1) isolado e associado com sulfentrazone (700 e 800 g ha-1), todos com e sem incorporação ao solo antes do plantio. Após plantio, cada tratamento recebeu a reaplicação da dose de ametryn + flumioxazin e após quebra-lombo sulfentrazone (700 g ha-1) + clomazone (1100 g ha-1). As parcelas (7,5 x 8 x 1,5m) receberam semeadura de Panicum maximum, Urochloa decumbens, Digitaria horizontalis, Ipomoea hederifolia, Ipomoea quamoclit e Ipomoea purpurea antes da aplicação em pré-plantio. Todos os tratamentos promoveram controles excelentes (94,0 a 100,0%) sobre as espécies estudadas sem comprometer a produtividade de colmos até aos 400 dias após plantio da cana-de-açúcar
Are there differences in auscultatory pulse in total blood flow restriction between positions, limbs and body segments?
Verification of the auscultatory pulse in total blood flow restriction (BFR) has been a limiting factor in studies due to the way in which it is evaluated and prescribed, as hemodynamic measurements can be directly affected by gravity. The aim of the present study was to compare the auscultatory pulse in BFR between positions, genders, limbs and body segments in healthy young individuals. A total of 156 subjects participated in the study, 76 of whom were male and 80 of whom were female (23.9±3.7 years, 66.5±11.5 kg, 1.67±0.07 m). After filling in registration data, anthropometry was evaluated, and BFR pressure was determined. BFR was evaluated in a randomized manner in both limbs (upper and lower) and in both segments (right and left) in the following positions: a) lying in the supine position; B) sitting with knees and trunk at 90°; and c) standing in the anatomical position. Significant differences were observed between the lying, sitting and standing positions (p0.05). The BFR point appears to differ between positions, genders, lower limbs and segments. Therefore, it is recommended that health professionals should check the BFR point in the position relating to the exercise that will be performed, taking into account gender, lower limbs and body segments
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