Experiment of static and dynamic characteristics of spiral grooved seals

The leakages and the dynamic characteristics of six types of spiral grooved seals are experimentally investigated. The effect of the helix angle of the seal is investigated mainly under the condition of the same nominal clearances, land and groove lengths, and groove depths. The dynamic characteristics are measured for various parameters such as preswirl velocity, pressure difference between inlet and outlet of the seal, whirling amplitude, whirling speed, and rotating speed of the rotor. The results are also compared with leakage increases with the increase of the helix angle, but as the rotating speed increases, the leakages of the larger helix angle seals quickly drop. The leakage of the smooth-stator (SS)/smooth-grooved rotor (SGR) seal drops faster than that of the spiral-grooved stator (SGS)/smooth-rotor (SR) seal. It is found that a circumferential flow can be produced by the flow along the helix angle direction, and this circumferential flow acts as a negative swirl. For the present helix angle range, there is an optimum helix angle with which the seal has a comparatively positive effect on the rotor stability. Compared with the SGS/SR seals, the SS/SGR seal has a worse effect on the rotor stability

Status of major southern California marine sport fish species with management recommendations, based on analyses of catch and size composition data collected on board commercial passenger fishing vessels from 1985 through 1987

This report on the status of major southern California marine sport fish species, together with management recommendations, is based on analyses of catch and size composition data, which were collected on board Commercial Passenger Fishing Vessels (CPFV) from 1985 through 1987. The project was designed to determine the status of those fishes that support the CPFV industry, and to make management recommendations when deemed necessary. We collected and analyzed data based on random, stratified, on-board sampling of weekday (excluding holidays), open CPFV's on a year-round basis. We sampled 1/2-day, 3/4-day, and full-day type trips at a level of 5%. The survey area extended from below the United States-Mexican border to Point Arguello. Catch estimates were extrapolated to include weekday as well as weekend and holiday, open and chartered CPFV's. We sampled 736 CPFV trips in 1985, 650 in 1986, and 631 in 1987. We encountered 180 species of fishes, including 49 species of rockfishes. We performed detailed analyses on 14 non-rockfish species and 12 rockfish species, as well as all fishes as a group and all rockfishes as a group. We found a moderate increase in total catch of combined fish species between this study and one in the mid-1970's, due primarily to sizeable increases in catches of Pacific mackerel, kelp bass, barred sand bass, and barracuda. However, we also found that there has been more than a 50% decline in the CPFV rockfish catches, due primarily to substantial decreases in catches of bocaccio, chilipepper, and olive rockfish. We have recommended that the current 15-rockfish bag limit regulation be reduced to a 10-rockfish bag limit, and that additional and equitable conservation measures also be implemented on the commercial rockfish fishery. (385pp.

Doping-driven Mott transition in La_{1-x}Sr_xTiO_3 via simultaneous electron and hole doping of t2g subbands

The insulator to metal transition in LaTiO_3 induced by La substitution via Sr is studied within multi-band exact diagonalization dynamical mean field theory at finite temperatures. It is shown that weak hole doping triggers a large interorbital charge transfer, with simultaneous electron and hole doping of t2g subbands. The transition is first-order and exhibits phase separation between insulator and metal. In the metallic phase, subband compressibilities become very large and have opposite signs. Electron doping gives rise to an interorbital charge flow in the same direction as hole doping. These results can be understood in terms of a strong orbital depolarization.Comment: 4 pages, 5 figure

Isospin fractionation and isoscaling in dynamical nuclear collisions

Isoscaling is found to hold for fragment yields in the antisymmetrized molecular dynamics (AMD) simulations for collisions of calcium isotopes at 35 MeV/nucleon. This suggests the applicability of statistical considerations to the dynamical fragment emission. The observed linear relationship between the isoscaling parameters and the isospin asymmetry of fragments supports the above suggestion. The slope of this linear function yields information about the symmetry energy in low density region where multifragmentation occurs.Comment: 11 pages, 6 figure

Spin Polarization and Magneto-Coulomb Oscillations in Ferromagnetic Single Electron Devices

The magneto-Coulomb oscillation, the single electron repopulation induced by external magnetic field, observed in a ferromagnetic single electron transistor is further examined in various ferromagnetic single electron devices. In case of double- and triple-junction devices made of Ni and Co electrodes, the single electron repopulation always occurs from Ni to Co electrodes with increasing a magnetic field, irrespective of the configurations of the electrodes. The period of the magneto-Coulomb oscillation is proportional to the single electron charging energy. All these features are consistently explained by the mechanism that the Zeeman effect induces changes of the Fermi energy of the ferromagnetic metal having a non-zero spin polarizations. Experimentally determined spin polarizations are negative for both Ni and Co and the magnitude is larger for Ni than Co as expected from band calculations.Comment: 4 pages, 3 figures, uses jpsj.sty, submitted to J. Phys. Soc. Jp

Antibody localization in horse, rabbit, and goat antilymphocyte sera

The localization of antibodies was studied in rabbit, goat, and horse ALS raised by weekly immunization with canine or human spleen cells for 4 to 12 weeks. A combination of analytic techniques was used including column chromatography, electrophoresis, immunoelectrophoresis, determination of protein concentration, and measurement of antibody titers. In the rabbit and goat ALS, virtually all of the leukoagglutinins and lymphocytotoxins were in the easily separable IgG; accidentally induced thromboagglutinins were in the same location. In the rabbit hemagglutinins were found in both the IgG and IgM, whereas in the goat these were almost exclusively in the IgM. The antiwhite cell antibodies were most widely distributed in the horse. The cytotoxins were primarily in the IgG, but the leukoagglutinins were most heavily concentrated in the T-equine globulin which consists mostly of IgA. By differential ammonium sulfate precipitation of a horse antidoglymphocyte serum, fractions were prepared that were rich in IgG and IgA. Both were able to delay the rejection of canine renal homografts, the IgA-rich preparation to a somewhat greater degree. The findings in this study have been discussed in relation to the refining techniques that have been used for the production of globulin from heterologous ALS. © 1970

Transport Model Simulations of Projectile Fragmentation Reactions at 140 MeV/nucleon

The collisions in four different reaction systems using $^{40,48}$Ca and $^{58,64}$Ni isotope beams and a Be target have been simulated using the Heavy Ion Phase Space Exploration and the Antisymmetrized Molecular Dynamics models. The present study mainly focuses on the model predictions for the excitation energies of the hot fragments and the cross sections of the final fragments produced in these reactions. The effects of various factors influencing the final fragment cross sections, such as the choice of the statistical decay code and its parameters have been explored. The predicted fragment cross sections are compared to the projectile fragmentation cross sections measured with the A1900 mass separator. At $E/A=140$ MeV, reaction dynamics can significantly modify the detection efficiencies for the fragments and make them different from the efficiencies applied to the measured data reported in the previous work. The effects of efficiency corrections on the validation of event generator codes are discussed in the context of the two models.Comment: 28 pages, 13 figure