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Trigonometric parallaxes have been measured by Dahn et al. (2002) for 28 cool dwarfs and brown dwarfs, including 17 L dwarfs and three T dwarfs. Broadband CCD and near-IR photometry (VRIz*JHK) have been obtained for these objects and for 24 additional late-type dwarfs. These data have been supplemented with astrometry and photometry from the literature, including parallaxes for the brighter companions of ten L and two T dwarfs. The absolute magnitudes and colors are reviewed here. The I-J color and the spectral type are both good predictors of absolute magnitude for late-M and L dwarfs. M_J becomes monotonically fainter with I-J color and with spectral type through late-L dwarfs, then brightens for early-T dwarfs. In contrast, the J-K color correlates poorly with absolute magnitude for L dwarfs. Using several other parameters from the literature (Li detection, H-alpha emission strength, projected rotation velocity, and tangential velocity), we fail to uncover any measurable parameter that correlates with the anomalous J-K color., Comment: 4 pages, including 2 figures. Paper given at IAU Symp. 211, Brown Dwarfs, ed. E.L. Martin

Trigonometric parallax determinations are presented for 28 late type dwarfs and brown dwarfs, including eight M dwarfs with spectral types between M7 and M9.5, 17 L dwarfs with spectral types between L0 and L8, and three T dwarfs. Broadband photometry at CCD wavelengths (VRIz) and/or near-IR wavelengths (JHK) are presented for these objects and for 24 additional late-type dwarfs. Supplemented with astrometry and photometry from the literature, including ten L and two T dwarfs with parallaxes established by association with bright, usually HIPPARCOS primaries, this material forms the basis for studying various color-color and color-absolute magnitude relations. The I-J color is a good predictor of absolute magnitude for late-M and L dwarfs. M_J becomes monotonically fainter with I-J color and with spectral type through late-L dwarfs, then brightens for early-T dwarfs. The combination of zJK colors alone can be used to classify late-M, early-L, and T dwarfs accurately, and to predict their absolute magnitudes, but is less effective at untangling the scatter among mid- and late-L dwarfs. The mean tangential velocity of these objects is found to be slightly less than that for dM stars in the solar neighborhood, consistent with a sample with a mean age of several Gyr. Using colors to estimate bolometric corrections, and models to estimate stellar radii, effective temperatures are derived. The latest L dwarfs are found to have T_eff ~ 1360 K., Comment: 48 pages, including 7 figures and 6 tables. Accepted for AJ

Preliminary trigonometric parallaxes and BVI photometry are presented for two dwarf carbon stars, LP765-18 (= LHS1075) and LP328-57 (= CLS96). The data are combined with the literature values for a third dwarf carbon star, G77-61 (= LHS1555). All three stars have very similar luminosities (9.6

New method for installing strain gages in structural bolts is implemented as standard workbench procedure. Rather than potting gages in a hole along axis of bolt, gages are first installed on outside of plastic carrier tube. Tube is then epoxied in axial hole. Procedure can be used to prepare gages to monitor bolt tension, shear, or torsion.

A method of automatic body-fitted curvilinear coordinate generation is described and used to construct a finite-difference solution of the full incompressible time-dependent Navier-Stokes equations for the unsteady laminar viscous flow arbitrary two-dimensional airfoils or any other two-dimensional body. A method of controlling the spacing of the coordinate lines encircling the body is developed in order to treat high Reynolds number flows, since the coordinate lines must concentrate near the surface to a greater degree as the Reynolds number increases. Multiple airfoils and submerged hydrofoils are treated as illustrative examples. The solution shows good agreement with the Blasius boundary layer solution for the flow past a semi-infinite flat plate.

A procedure for numerical solution of the time-dependent, incompressible Navier-Stokes equations for the flow about arbitrarily shaped two-dimensional bodies is given. This solution is based on a technique of automatic numerical generation of a curvilinear coordinate system having a coordinate line coincident with the body contour regardless of its shape. The implicit solution utilizes the vorticity-stream function formulation with a false-position iterative adjustment of the surface vorticity in satisfaction of the no-slip boundary condition. Excellent agreement with the Blasius boundary layer solution is obtained for a semi-infinite flat plate. Results are presented for Reynolds numbers up to 2000 for several airfoils and a cambered rock.

Solubility theory describes the effects of both concentration and temperature on solute activity coefficients. It predicts the salting-out effect and the decrease in solubility of non-polar gases with increased electrolyte concentration, and can be used to calculate heats of solution, entropies, and partial molal volumes of dissolved gases

Design and flight test data on Super Loki Dart sounding rocket system for obtaining high altitude wind profiles with low cost rocket vehicle and radar-reflective chaff payload

Cajun Dart vehicle for low cost meteorological soundings at 95 kilometers