Vortex servovalve for fluidic or electrical input

Proportional-pressure control servovalve consisting of fluid amplifier bellows-driven jet-pipe and two vortex valves operating in push-pull, with a pair of bellows for pressure feedback is tolerant to comtaminant particles and meets minimum standby flow requirements for applications such as rocket thruster nozzles

Fluidic proportional thruster for SPARCS 4

Design, development, fabrication, and acceptance test results for two fluidic proportional thrusters for use in SPARCS

An experimental investigation on the subcritical instability in plane Poieseuille flow

The relationship between the three dimensional properties of the fundamental flow of a plane Poieseuille flow and subcritical stability was studied. An S-T wave was introduced into the flow and the three dimensional development of the wave observed. Results indicate that: (1) the T-S wave has three dimensional properties which are synchronous with the fundamental flow, but there is damping at microamplitude; (2) when the amplitude reaches a certain threshold, subcritical instability and peak valley bifurcation occur simultaneously and a peak valley structure is formed; (3) this threshold depends to a great extent on the frequency; and (4) after the peak valley bifurcation there is a transition to a turbulent flow by the process of laminar flow collapse identical to that in Blasius flow

Field induced long-range-ordering in an S=1 quasi-one-dimensional Heisenberg antiferromagnet

We have measured the heat capacity and magnetization of the spin one one-dimensional Heisenberg antiferromagnet NDMAP and constructed a magnetic field versus temperature phase diagram. We found a field induced long-range magnetic ordering. We have been successful in explaining the phase diagram theoretically.Comment: 6 pages, 18 figure

Tuning of antigen sensitivity by T cell receptor-dependent negative feedback controls T cell effector function inflammed tissues

Activated T cells must mediate effector responses sufficient to clear pathogens while avoiding excessive tissue damage. Here we have combined dynamic intravital microscopy with ex vivo assessments of T cell cytokine responses to generate a detailed spatiotemporal picture of CD4+ T cell effector regulation in the skin. In response to antigen, effector T cells arrested transiently on antigen presenting cells, briefly producing cytokine and then resuming migration. Antigen recognition led to PD-1 upregulation of the programmed death-1 (PD-1) glycoprotein by T cells and blocking its canonical ligand, programmed death-ligand 1 (PD-L1), lengthened the duration of migration arrest and cytokine production, showing that PD-1 interaction with PD-L1 is a major negative feedback regulator of antigen responsiveness. We speculate that the immune system employs a mechanism involving T cell recruitment, transient activation, and rapid desensitization, allowing the T cell response to rapidly adjust to changes in antigen presentation and minimize collateral injury to the host

Atmospheric neutrino flux at INO, South Pole and Pyh\"asalmi

We present the calculation of the atmospheric neutrino fluxes for the neutrino experiments proposed at INO, South Pole and Pyh\"asalmi. Neutrino fluxes have been obtained using ATMNC, a simulation code for cosmic ray in the atmosphere. Even using the same primary flux model and the interaction model, the calculated atmospheric neutrino fluxes are different for the different sites due to the geomagnetic field. The prediction of these fluxes in the present paper would be quite useful in the experimental analysis.Comment: 12Pages,9Fig

Behavior of Li abundances in solar-analog stars II. Evidence of the connection with rotation and stellar activity

We previously attempted to ascertain why the Li I 6708 line-strengths of Sun-like stars differ so significantly despite the superficial similarities of stellar parameters. We carried out a comprehensive analysis of 118 solar analogs and reported that a close connection exists between the Li abundance A_Li and the line-broadening width (v_r+m; mainly contributed by rotational effect), which led us to conclude that stellar rotation may be the primary control of the surface Li content. To examine our claim in more detail, we study whether the degree of stellar activity exhibits a similar correlation with the Li abundance, which is expected because of the widely believed close connection between rotation and activity. We measured the residual flux at the line center of the strong Ca II 8542 line, r_0(8542), known to be a useful index of stellar activity, for all sample stars using newly acquired spectra in this near-IR region. The projected rotational velocity (v_e sin i) was estimated by subtracting the macroturbulence contribution from v_r+m that we had already established. A remarkable (positive) correlation was found in the A_Li versus (vs.) r_0(8542) diagram as well as in both the r_0(8542) vs. v_e sin i and A_Li vs. v_e sin i diagrams, as had been expected. With the confirmation of rotation-dependent stellar activity, this clearly shows that the surface Li abundances of these solar analogs progressively decrease as the rotation rate decreases. Given this observational evidence, we conclude that the depletion of surface Li in solar-type stars, probably caused by effective envelope mixing, operates more efficiently as stellar rotation decelerates. It may be promising to attribute the low-Li tendency of planet-host G dwarfs to their different nature in the stellar angular momentum.Comment: 12 pages, 9 figures; accepted for publication in Astron. Astrophys