8,183 research outputs found
Low-speed wind tunnel investigation of the lateral-directional characterisitcs of a large-scale variable wing-sweep fighter model in the high-lift configuration
The low-speed characteristics of a large-scale model of the F-14A aircraft were studied in tests conducted in the Ames Research Center 40- by 80-Foot Wind Tunnel. The primary purpose of the present tests was the determination of lateral-directional stability levels and control effectiveness of the aircraft in its high-lift configuration. Tests were conducted at wing angles of attack between minus 2 deg and 30 deg and with sideslip angles between minus 12 deg and 12 deg. Data were taken at a Reynolds number of 8.0 million based on a wing mean aerodynamic chord of 2.24 m (7.36 ft). The model configuration was changed as required to show the effects of direct lift control (spoilers) at yaw, yaw angle with speed brake deflected, and various amounts and combinations of roll control
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
SENSITIVITY OF GROSS STATE PRODUCT TO CYCLICAL AND STRUCTURAL CHANGE
The sensitivity of regional industry to business cycles has been widely documented. Responses of individual businesses and industries in a specific region or state to each phase of the business cycle has been less well analyzed and understood. Lacking in all the documentation, moreover, is reference to the impact of business cycles on interregional trade and regional interindustry structure and to the separation of these impacts from those due to business activity location and dislocation. To deal with these limitations, state-level location quotient and shift-share analyses of year-to-year changes in industry-specific contribution to gross state product are used in differentiating the varying degrees of cyclical sensitivity among industries and regions and then, in later studies, to account for these differences in parallel analyses of the structure of inter-regional trade and interindustry transactions among selected groups of states. A micro-to-macro analytical framework is offered, finally, for testing working hypotheses pertaining to the sensitivity of businesses, industries and regions to the business cycle and to structural dislocation.Community/Rural/Urban Development,
Structural transitions of monoolein bicontinuous cubic phase induced by inclusion of protein lysozyme solutions
Inclusion of protein lysozyme molecules in lipidic monoolein cubic phase
induces a transition from a structure to one.
Small-angle X-ray scattering (SAXS) method with high intensity synchrotron
radiation enabled us to follow closely the transition depending on the
conditions of lysozyme solutions. We showed that concentrated lysozyme
solutions induced the appearance of the structure coexisting
with the structure. From the relation between the lattice
parameters of these two structures it was shown that they were related by the
Bonnet transformation of underlying triply periodic minimal surfaces. We found
that the transition also occurred at lower lysozyme concentration when NaCl
induced attraction between lysozyme molecules. The origin of the transition was
considered as a frustration in the cubic phase where lysozyme molecules were
highly confined. A simple estimation of the frustration was given, which took
into account of the translational entropy of lysozyme molecules. At the highest
concentration of lysozyme and NaCl the structure was found to
disappear and left only the structure. This was probably
either due to the crystallization or phase separation of lysozyme solutions
ongoing microscopically, which absorbed lysozyme molecules from channels of the
cubic phase and thus removed the frustration.Comment: 8 pages, 5 figure
Precursor of Color Superconductivity
We investigate possible precursory phenomena of color superconductivity at
finite temperature with an effective theory of QCD. It is found that the
fluctuation of the diquark pair field exists with a prominent strength even
well above the critical temperature . We show that such a fluctuaiton
forms a collective mode, the corresponding pole of which approaches the origin
as is lowered to in the complex energy plane. We discuss the possible
relevance of the precursor to the observables to be detected in heavy-ion
collisions.Comment: 4 pages, 5 figures, Talk presented at the XVIth International
Conference on Particles and Nuclei (PANIC02), Osaka, Japan, Sep.30 - Oct.4,
2002, Uses espcrc1.st
Half quantum vortex in superfluid He-A phase in parallel plate geometry
The half quantum vortex(HQV) in condensate has been studied, since it was
predicted by Salomaa and Volovik in superfluid He-A phase. However, an
experimental evidence for its existence has not been reported so far. Motivated
by a recent experimental report by Yamashita et al\cite{yamashita}, we study
the HQVs in superfluid He confined between two parallel plates with a gap D
10 m in the presence of a magnetic field H 26 mT
perpendicular to the parallel plates. We find that the bound HQVs are more
stable than the singular vortices and free pairs of HQVs, when the rotation
perpendicular to the parallel plates is below the critical speed, 2 rad/s. The bound pair of HQVs accompanies the tilting of -vector out of the plane, which leads to an additional absorption in NMR
spectra. Our study appears to describe the temperature and rotation dependence
of the observed satellite NMR signal, which supports the existence of the HQVs
in He.Comment: 5 pages, 5 figure
Anisotropic s-wave superconductivity: comparison with experiments on MgB2 single crystals
The recently discovered superconductivity in MgB2 has captured world
attention due to its simple crystal structure and relatively high
superconducting transition temperature Tc=39K. It appears to be generally
accepted that it is phonon-mediated s-wave BCS-like superconductivity.
Surprisingly, the strongly temperature dependent anisotropy of the upper
critical field, observed experimentally in magnesium diboride single crystals,
is still lacking a consistent theoretical explanation. We propose a simple
single-gap anisotropic s-wave order parameter in order to compare its
implications with the prediction of a multi-gap isotropic s-wave model. The
quasiparticle density of states, thermodynamic properties, NMR spin-lattice
relaxation rate, optical conductivity, and Hc2 anisotropy have been analyzed
within this anisotropic s-wave model. We show that the present model can
capture many aspects of the unusual superconducting properties of MgB2
compound, though more experimental data appear to be necessary from single
crystal MgB2.Comment: 7 pages, 6 figures, some minor changes, to appear in Europhys. Let
Are lepton flavor mixings in the democratic mass matrix stable against quantum corrections?
We investigate whether the lepton flavor mixing angles in the so-called
democratic type of mass matrix are stable against quantum corrections or not in
the minimal supersymmetric standard model with dimension five operator which
induces neutrino mass matrix. By taking simple breaking patterns of or flavor symmetries and the scale where
democratic textures are induced as GeV, we find that the stability
of the lepton flavor mixing angles in the democratic type of mass matrix
against quantum corrections depends on the solar neutrino solutions. The
maximal flavor mixing of the vacuum oscillation solution is spoiled by the
quantum corrections in the experimental allowed region of . The
large angle MSW solution is spoiled by the quantum corrections in the region of
. The condition of is needed in order to
obtain the suitable mass squared difference of the small angle MSW solution.
These strong constraints must be regarded for the model building of the
democratic type of mass matrixComment: 12pages,LaTe
Gapped optical excitations from gapless phases: imperfect nesting in unconventional density waves
We consider the effect of imperfect nesting in quasi-one-dimensional
unconventional density waves in the case, when the imperfect nesting and the
gap depends on the same wavevector component.
The phase diagram is very similar to that in a conventional density wave. The
density of states is highly asymmetric with respect to the Fermi energy.
The optical conductivity at T=0 remains unchanged for small deviations from
perfect nesting. For higher imperfect nesting parameter, an optical gap opens,
and considerable amount of spectral weight is transferred to higher
frequencies. This makes the optical response of our system very similar to that
of a conventional density wave. Qualitatively similar results are expected in
d-density waves.Comment: 8 pages, 7 figure
- …
