8,294 research outputs found
Matrix Theory, Hilbert Scheme and Integrable System
We give a reinterpretation of the matrix theory discussed by Moore, Nekrasov
and Shatashivili (MNS) in terms of the second quantized operators which
describes the homology class of the Hilbert scheme of points on surfaces. It
naturally relate the contribution from each pole to the inner product of
orthogonal basis of free boson Fock space. These basis can be related to the
eigenfunctions of Calogero-Sutherland (CS) equation and the deformation
parameter of MNS is identified with coupling of CS system. We discuss the
structure of Virasoro symmetry in this model.Comment: 13 pages 1 figur
Improved Taylor Expansion method in the Ising model
We apply an improved Taylor expansion method, which is a variational scheme
to the Ising model in two dimensions. This method enables us to evaluate the
free energy and magnetization in strong coupling regions from the weak coupling
expansion, even in the case of a phase transition. We determine the approximate
value of the transition point using this scheme. In the presence of an external
magnetic field, we find both stable and metastable physical states.Comment: 13 pages, 9 figure
d-Psicose Inhibits Intestinal α-Glucosidase and Suppresses the Glycemic Response after Ingestion of Carbohydrates in Rats
d-psicose is one of the rare sugars present in small quantities in commercial carbohydrates and agricultural products. In this study, we investigated the effects of d-psicose on the activities of α-amylases and α-glucosidases in vitro, and evaluated the effects of d-psicose on the in vivo postprandial glycemic response using rats. In the in vitro study, d-psicose potently inhibited the intestinal sucrase and maltase, however, slightly inhibited the intestinal and salivary α-amylase activities. Male Wistar rats (6 months old) were administrated 2 g/kg of sucrose, maltose or soluble starch together with 0.2 g/kg of d-psicose or d-fructose. The d-psicose significantly inhibited the increment of plasma glucose concentration induced by sucrose or maltose. The starch-induced glycemic response tended to be suppressed by d-psicose, however the suppression was not significant. These results suggest that d-psicose inhibits intestinal sucrase and maltase activities and suppresses the plasma glucose increase the normally occurs after sucrose and maltose ingestion. Thus, d-psicose may be useful in preventing postprandial hyperglycemia in diabetic patients when foods containing sucrose and maltose are ingested
Diagnosis of a unit-wide disturbance caused by saturation in a manipulated variable
It is well known that faulty control valves with friction in the moving parts lead to limit cycle oscillations which can propagate to other parts of the plant. However, a control loop with healthy valve can also undergo oscillatory behavior. The root cause of a unit-wide oscillation in a distillation column was traced to a pressure control loop in a case study at Mitsui Chemicals. The diagnosis was made by means of a new technique of pattern matching of the time-resolved frequency spectrum using a wavelet analysis tool. The method identified key characteristics shared by measurements at various places in the column and quantified the similarities.
Non-linearity was detected in the time trend of the pressure measurement, a result which initially suggested the root cause was a faulty actuator or sensor. Further analysis showed, however, that the source of non-linearlity was periodic saturation of the manipulated variable caused by slack tuning. The problem was remidied by changing the controller tuning settings and the unit-wide disturbance then went away
Adiabatic Selfconsistent Collective Coordinate Method for Large Amplitude Collective Motion in Superconducting Nuclei
An adiabatic approximation to the selfconsistent collective coordinate method
is formulated in order to describe large amplitude collective motions in
superconducting nuclei on the basis of the time-dependent
Hartree-Fock-Bogoliubov equations of motion. The basic equations are presented
in a local harmonic form which can be solved in a similar way as the
quasiparticle RPA equations. The formalism guarantees the conservation of
nucleon number expectation values. An extension to the multi-dimensional case
is also discussed
Continuum Coupling and Pair Correlation in Weakly Bound Deformed Nuclei
We formulate a new Hartree-Fock-Bogoliubov method applicable to weakly bound
deformed nuclei using the coordinate-space Green's function technique. An
emphasis is put on treatment of quasiparticle states in the continuum, on which
we impose the correct boundary condition of the asymptotic out-going wave. We
illustrate this method with numerical examples.Comment: 5 pages, 4 figures, Proceedings of the Japanese French Symposium -
New paradigms in Nuclear Physics, Paris, 29th September - 2nd October, to be
published in Int. J. of Modern Physics
The Si ribbon crystal for the solar battery using the horizontal pull method
A method utilizing a device to spray noble gases to cool the site of silicon crystal growth is described. The salient points are: (1) soft and uniform cooling was possible, (2) the length of the boundary surface of growth along the growth direction was made long over a wide width compared to the thickness, and (3) this made it possible to effectively remove the heat produced from solification. By using forced gas spraying on the solution surface in contact with the points of crystal growth, growth at the points of growth is enhanced and the rate of growth is speeded up
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