55 research outputs found
Charged and Neutral Vortex Excitations in a Mean Field Theory for the Fractional Quantum Hall Effect
Applying a bi-local mean field approximation to the fractional quantum Hall
state of , we obtain charged and neutral vortex mean field solutions
numerically. We calculate the mean field energy and the fluctuation
corrections. The charged vortex has a fractional charge and a fractional
angular momentum. The neutral vortex is a bound state of two charged vortices
and has a zero charge and a zero angular momentum. The creation energy of the
neutral vortex is about a half of the pair creation energy of two charged
vortices. The magnetic field dependence of the gap energy agrees with the
Laughlin's quasiparticle gap energy.Comment: 22 pages, EPHOU-94-001, 8 figures available as a hard copy via
air-mai
Flux State in von Neumann lattice and Fractional Hall Effect
Formulation of quantum Hall dynamics using von Neumann lattice of guiding
center coordinates is presented. A topological invariant expression of the Hall
conductance is given and a new mean field theory of the fractional Hall effect
based on flux condensation is proposed. Because our mean field Hamiltonian has
the same form as Hofstadter Hamiltonian, it is possible to understand
characteristic features of the fractional Hall effect from Hofstadter's
spectrum. Energy gap and other physical quantities are computed and are
compared with the experiments. A reasonable agreement is obtained.Comment: 28 pages, LaTeX, 4 figure
Paired and Stripe States in the Quantum Hall System
We study a paired state at the half-filled Landau level using a mean field
theory on the von Neumann lattice. We obtain a microscopic model which shows a
continuous transition from the compressible stripe state to the paired state.
The energy gap in the paired state is calculated numerically at the half-filled
second Landau level.Comment: 4 pages, 1 figure, to be published in Physica
Stability of the compressible quantum Hall state around the half-filled Landau level
We study the compressible states in the quantum Hall system using a mean
field theory on the von Neumann lattice. In the lowest Landau level, a kinetic
energy is generated dynamically from Coulomb interaction. The compressibility
of the state is calculated as a function of the filling factor and the
width of the spacer between the charge carrier layer and dopants. The
compressibility becomes negative below a critical value of and the state
becomes unstable at . Within a finite range around , the
stable compressible state exists above the critical value of .Comment: 4 pages, 4 Postscript figures, RevTe
Desenvolvimento e aceitabilidade de geléia dietética de cubiu (Solanum sessiliflorum Dunal)
Visando o aproveitamento de frutos amazônicos e atender à demanda crescente por novos produtos no mercado, foi formulada e avaliada a aceitabilidade e vida-de-prateleira da geléia de cubiu contendo xilitol em substituição à sacarose. Os frutos procedentes da Estação Experimental do Ariaú do Instituto Nacional de Pesquisas da Amazônia foram branqueados, despolpados, triturados, peneirados e acondicionados em embalagens plásticas à temperatura de -20 ± 1 °C até o momento da utilização. Concomitantemente, uma alíquota da polpa foi analisada quanto à umidade, proteínas, lipídios, fibras solúveis e insolúveis, cinza, pH, acidez total, açúcares totais e redutores, e compostos fenólicos. Para a formulação da geléia com uso de xilitol e convencional foi utilizada a proporção de 1:1 (polpa:xilitol e polpa:sacarose), respectivamente. A mistura foi concentrada até a obtenção de 65 °Brix , com ajuste de pH e adição de pectina. As geléias foram avaliadas quanto aos teores de proteínas, lipídios, cinza, pH, acidez, açúcares e compostos fenólicos e a vida-de-prateleira por meio de análises físico-química, microbiológica e sensorial, mensalmente, por um período de 180 dias. Os resultados demonstraram que não houve diferença estatística entre a aceitabilidade das geléias à base de xilitol e convencional, e que ambas apresentaram estabilidade físico-química e microbiológica durante o seu armazenamento. O xilitol pode ser uma alternativa viável em substituição à sacarose para o preparo de geléia de cubiu.<br>With the aim of improving utilization of Amazonian fruits and satisfying the growing demand for new products in the market, we formulated a low calorie cubiu jam with xylitol as a sucrose substitute, and evaluated its shelf life and acceptability. The cubiu fruits from the Experimental Station of the National Research Institute of Amazonia (INPA) were harvested, bleached, pealed, ground, sieved, and stored in plastic bags at -20 ± 1 °C until their utilization. At the same time, triplicate samples of the cubiu pulp were analysed for humidity, protein, lipids, soluble and insoluble fibers, ash, pH, total acidity, total and reducing sugars, and phenolic compounds. The conventional and the xylitol-based jams were prepared with a 1:1 proportion of pulp:sucrose or pulp:xylitol, respectively. The mixture was concentrated up to 65° Brix with pH adjustment and pectin addition. The jams were analyzed for protein, lipids, ash, pH, acidity, sugar, and phenolic compounds. The shelf life was evaluated through monthly physicochemical, microbiological, and sensory analyses for a period of 180 days. The results showed no statistical difference between the acceptability of conventional and xylitol-based jams and presented the same physicochemical, microbiological stability during storage. Xylitol can be a viable sucrose substitute for the preparation of cubiu jams
The Japanese space gravitational wave antenna; DECIGO
DECi-hertz Interferometer Gravitational wave Observatory (DECIGO) is the future
Japanese space gravitational wave antenna. DECIGO is expected to open a new window of
observation for gravitational wave astronomy especially between 0.1 Hz and 10 Hz, revealing
various mysteries of the universe such as dark energy, formation mechanism of supermassive
black holes, and inflation of the universe. The pre-conceptual design of DECIGO consists of
three drag-free spacecraft, whose relative displacements are measured by a differential Fabry–
Perot Michelson interferometer. We plan to launch two missions, DECIGO pathfinder and pre-
DECIGO first and finally DECIGO in 2024
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