A Variational Principle for Dissipative Fluid Dynamics

In the variational principle leading to the Euler equation for a perfect fluid, we can use the method of undetermined multiplier for holonomic constraints representing mass conservation and adiabatic condition. For a dissipative fluid, the latter condition is replaced by the constraint specifying how to dissipate. Noting that this constraint is nonholonomic, we can derive the balance equation of momentum for viscous and viscoelastic fluids by using a single variational principle. We can also derive the associated Hamiltonian formulation by regarding the velocity field as the input in the framework of control theory.Comment: 15 page

Clebsch Potentials in the Variational Principle for a Perfect Fluid

Equations for a perfect fluid can be obtained by means of the variational principle both in the Lagrangian description and in the Eulerian one. It is known that we need additional fields somehow to describe a rotational isentropic flow in the latter description. We give a simple explanation for these fields; they are introduced to fix both ends of a pathline in the variational calculus. This restriction is imposed in the former description, and should be imposed in the latter description. It is also shown that we can derive a canonical Hamiltonian formulation for a perfect fluid by regarding the velocity field as the input in the framework of control theory.Comment: 15 page

Dynamic Estimation of the Consumer Demand System in Postwar Japan

This report explores the dynamic demand relations operative in Japan in the period 1951-80 in order to elucidate the dynamic nature and characteristics of the varied structures of consumer demand. The analysis was conducted at the subgroup level on the basis of time series of family budget data, using Powell's version of the linear expenditure system. A taste variable was incorporated into the expenditure functions and five alternative specifications of the taste variable were utilized to take account of recent structural changes in demand. The first two are based on current annual increase in income and on current annual rate of increase in income. The next two incorporate lagged annual increase in income and lagged annual rate of increase in income, and the last specification is based on the time trend. The analysis was based on a 21-commodity breakdown and numerous individual segments of the total observation period were chosen for estimating the dynamic model. The taste variables had the effect of stabilizing the demand system as a whole and they considerably reduced the instability of important estimates, such as those for money flexibility, subsistence consumption levels, etc. Consumption patterns in Japan are considered to have changed substantially toward more "Westernized" living and eating habits since the beginning of the 1960s. Per capita consumption of rice and fish went down with the increase in deflated income, whereas the consumption of animal protein food, fruit, beverages, and food away from the home all increased rapidly. Owing to income and taste effects, transportation, recreation, and rent showed a notable upward shift in average shares, while rice consumption declined remarkably in terms of its reduced marginal share. Broadly speaking, estimated average substitution elasticity in Leser's model is inversely proportional to estimated money flexibility, which itself has a close relation to price elasticities. High values of money flexibility were obtained for the lower levels of per capita income in the early years of the period studied. For periods of more rapid economic growth, money flexibility estimates dropped to some extent, while for recent years they rose appreciably, reflecting the smaller response of consumer demand to price changes

Earthquake Induced Slope Failure Simulation by SPH

Majority of slope stability, slope displacement and soil liquefaction analyses subjected to earthquake loading condition employed the finite element method (FEM) as the standard numerical tool. However, mechanism of soil failure in such condition often involved extremely large deformation and failure behaviors, which were unable to be modeled by FEM since this method was suffered from the grid distortion. In an attempt to overcome this limitation, we present herein our first attempt to extend the smoothed particle hydrodynamics (SPH) method to analyze slope failure behavior due to seismic shaking. For the sake of simplicity, effect of pore-water pressure was not taken into consideration. The numerical framework was then applied to simulate the failure behavior of a slope subjected to a seismic loading. Experimental model was also conducted to verify the numerical performance. It is shown that SPH can simulate fairly well the slope failure behavior in the model test, especially in prediction of the failure surface. The paper suggests that SPH should be considered as a powerful alternative for computation of geomaterials subjected to earthquake loading conditions

Mevastatin reduces cartilage degradation in rabbit experimental osteoarthritis through inhibition of synovial inflammation

SummaryObjectiveTo examine the therapeutic efficacy of an HMG-CoA reductase inhibitor (statin) in rabbit osteoarthritis (OA) in vitro and in vivo.MethodsIn the presence or absence of mevastatin, rabbit chondrocytes and synoviocytes were incubated with Interleukin-1β (IL-1β), and analyzed by biochemical methods. Thirty-two mature rabbits that underwent bilateral anterior cruciate ligament transaction (ACLT) received six consecutive weekly intra-articular injections of mevastatin at three different concentrations or a control solution. All animals were sacrificed 6 weeks after ACLT, and the knee joints were assessed by morphological, histological, immunohistochemical, and biochemical methods.ResultsMevastatin inhibited IL-1β stimulation of gene expression of monocyte chemoattractant protein-1 (MCP-1) and matrix-metalloproteinases 3 (MMP-3), in synoviocytes but not chondrocytes. The levels of MCP-1 and MMP-3 productions in synoviocytes were significantly reduced by statin-treatment. In rabbit with OA, intra-articular injection of mevastatin significantly reduced cartilage degradation, as assessed by morphological and histological examinations. Synovial tissues of knees treated with mevastatin showed less severe inflammatory responses with reduced thickness of synovial cell lining and less infiltration of subsynovial CD68+monocyte lineage cells compared to untreated control knees. Relative mRNA expressions of MCP-1, IL-1β, MMP-3, and MMP-13 were reduced in synovial tissues, but not articular cartilage, of knees treated with mevastatin compared with untreated control knees.ConclusionDuring the development of experimental OA, intra-articular administration of HMG-CoA reductase inhibitor (statin) reduces inflammatory cell infiltration and matrix-degrading enzyme expression, thus limiting cartilage degradation

A New Galactic Extinction Map of the Cygnus Region

We have made a Galactic extinction map of the Cygnus region with 5' spatial resolution. The selected area is 80^\circ to 90^\circ in the Galactic longitude and -4^\circ to 8^\circ in the Galactic latitude. The intensity at 140 \mum is derived from the intensities at 60 and 100 \mum of the IRAS data using the tight correlation between 60, 100, and 140 \mum found in the Galactic plane. The dust temperature and optical depth are calculated with 5' resolution from the 140 and 100 \mum intensity, and Av is calculated from the optical depth. In the selected area, the mean dust temperature is 17 K, the minimum is 16 K, and the maximum is 30 K. The mean Av is 6.5 mag, the minimum is 0.5 mag, and the maximum is 11 mag. The dust temperature distribution shows significant spatial variation on smaller scales down to 5'. Because the present study can trace the 5'-scale spatial variation of the extinction, it has an advantage over the previous studies, such as the one by Schlegel, Finkbeiner, & Davis, who used the COBE/DIRBE data to derive the dust temperature distribution with a spatial resolution of 1^\circ. The difference of Av between our map and Schlegel et al.'s is \pm 3 mag. A new extinction map of the entire sky can be produced by applying the present method.Comment: 27 pages, 14 figures, accepted for publication in Ap

V1647 Orionis (IRAS 05436-0007) : A New Look at McNeil's Nebula

We present a study of the newly discovered McNeil's nebula in Orion using the JHKs-band simultaneous observations with the near-infrared (NIR) camera SIRIUS on the IRSF 1.4m telescope. The cometary infrared nebula is clearly seen extending toward north and south from the NIR source (V1647 Orionis) that illuminates McNeil's nebula. The compact nebula has an apparent diameter of about 70 arcsec. The nebula is blue (bright in J) and has a cavity structure with two rims extending toward north-east and north-west. The north-east rim is brighter and sharp, while the north-west rim is diffuse. The north-east rim can be traced out to ~ 40 arcsec from the location of the NIR source. In contrast, no cavity structure is seen toward the south, although diffuse nebula is extended out to ~ 20 arcsec. New NIR photometric data show a significant variation in the magnitudes (> 0.15 mag) of the source of McNeil's nebula within a period of one week, that is possibly under the phase of eruptive variables like FUors or EXors.Comment: 13 pages, 5 figures in JPEG format. Accepted for the publication in PASJ Letter

Near-Infrared Coronagraphic Observations of the T Tauri Binary System UY Aur

We present a near-infrared image of UY Aur, a 0.9" separated binary system, using the Coronagraphic Imager with Adaptive Optics on the Subaru Telescope. Thanks to adaptive optics, the spatial resolution of our image was ~0.1" in the full width at half maximum of the point spread function, the highest achieved. By comparison with previous measurements, we estimated that the orbital period is ~1640 yrs and the total mass of the binary is ~1.73 solar mass. The observed H-band magnitude of the secondary varies by as much as 1.3 mag within a decade, while that of the primary is rather stable. This inconstancy may arise from photospheric variability caused by an uneven accretion rate or from the rotation of the secondary. We detected a half-ring shaped circumbinary disk around the binary with a bright southwest part but a barely detectable northeast portion. The brightness ratio is ~57. Its inner radius and inclination are about 520 AU and 42, respectively. The disk is not uniform but has remarkable features, including a clumpy structure along the disk, circumstellar material inside the inner cavity, and an extended armlike structure. The circumstellar material inside the cavity probably corresponds to a clump or material accreting from the disk onto the binary. The armlike structure is a part of the disk, created by the accretion from the outer region of the disk or encounters with other stellar systems.Comment: 16 pages, 6 figures; accepted for publication in A