Dry electrodes for physiological monitoring

Subject preparation and application of sprayed dry electrodes for physiological monitorin

Method and apparatus for attaching physiological monitoring electrodes Patent

Adhesive spray process for attaching biomedical skin electrode

Filler bar heating due to stepped tiles in the shuttle orbiter thermal protection system

An analytical study was performed to investigate the excessive heating in the tile to tile gaps of the Shuttle Orbiter Thermal Protection System due to stepped tiles. The excessive heating was evidence by visible discoloration and charring of the filler bar and strain isolation pad that is used in the attachment of tiles to the aluminum substrate. Two tile locations on the Shuttle orbiter were considered, one on the lower surface of the fuselage and one on the lower surface of the wing. The gap heating analysis involved the calculation of external and internal gas pressures and temperatures, internal mass flow rates, and the transient thermal response of the thermal protection system. The results of the analysis are presented for the fuselage and wing location for several step heights. The results of a study to determine the effectiveness of a half height ceramic fiber gap filler in preventing hot gas flow in the tile gaps are also presented

A Spitzer/IRAC Search for Substellar Companions of the Debris Disk Star epsilon Eridani

We have used the InfraRed Array Camera (IRAC) onboard the Spitzer Space telescope to search for low mass companions of the nearby debris disk star epsilon Eridani. The star was observed in two epochs 39 days apart, with different focal plane rotation to allow the subtraction of the instrumental Point Spread Function, achieving a maximum sensitivity of 0.01 MJy/sr at 3.6 and 4.5 um, and 0.05 MJy/sr at 5.8 and 8.0 um. This sensitivity is not sufficient to directly detect scattered or thermal radiation from the epsilon Eridani debris disk. It is however sufficient to allow the detection of Jovian planets with mass as low as 1 MJ in the IRAC 4.5 um band. In this band, we detected over 460 sources within the 5.70 arcmin field of view of our images. To test if any of these sources could be a low mass companion to epsilon Eridani, we have compared their colors and magnitudes with models and photometry of low mass objects. Of the sources detected in at least two IRAC bands, none fall into the range of mid-IR color and luminosity expected for cool, 1 Gyr substellar and planetary mass companions of epsilon Eridani, as determined by both models and observations of field M, L and T dwarf. We identify three new sources which have detections at 4.5 um only, the lower limit placed on their [3.6]-[4.5] color consistent with models of planetary mass objects. Their nature cannot be established with the currently available data and a new observation at a later epoch will be needed to measure their proper motion, in order to determine if they are physically associated to epsilon Eridani.Comment: 36 pages, to be published on The Astrophysical Journal, vol. 647, August 200

Conservative evaluation of the uncertainty in the LAGEOS-LAGEOS II Lense-Thirring test

We deal with the test of the general relativistic gravitomagnetic Lense-Thirring effect currently ongoing in the Earth's gravitational field with the combined nodes \Omega of the laser-ranged geodetic satellites LAGEOS and LAGEOS II. One of the most important source of systematic uncertainty on the orbits of the LAGEOS satellites, with respect to the Lense-Thirring signature, is the bias due to the even zonal harmonic coefficients J_L of the multipolar expansion of the Earth's geopotential which account for the departures from sphericity of the terrestrial gravitational potential induced by the centrifugal effects of its diurnal rotation. The issue addressed here is: are the so far published evaluations of such a systematic error reliable and realistic? The answer is negative. Indeed, if the difference \Delta J_L among the even zonals estimated in different global solutions (EIGEN-GRACE02S, EIGEN-CG03C, GGM02S, GGM03S, ITG-Grace02, ITG-Grace03s, JEM01-RL03B, EGM2008, AIUB-GRACE01S) is assumed for the uncertainties \delta J_L instead of using their more or less calibrated covariance sigmas \sigma_{J_L}, it turns out that the systematic error \delta\mu in the Lense-Thirring measurement is about 3 to 4 times larger than in the evaluations so far published based on the use of the sigmas of one model at a time separately, amounting up to 37% for the pair EIGEN-GRACE02S/ITG-Grace03s. The comparison among the other recent GRACE-based models yields bias as large as about 25-30%. The major discrepancies still occur for J_4, J_6 and J_8, which are just the zonals the combined LAGEOS/LAGOES II nodes are most sensitive to.Comment: LaTex, 12 pages, 12 tables, no figures, 64 references. To appear in Central European Journal of Physics (CEJP

The effect of major depression on participation in preventive health care activities

<p>Abstract</p> <p>Background</p> <p>The objective of this study was to determine whether major depressive episodes (MDE) contribute to a lower rate of participation in three prevention activities: blood pressure checks, mammograms and Pap tests.</p> <p>Methods</p> <p>The data source for this study was the Canadian National Population Health Survey (NPHS), a longitudinal study that started in 1994 and has subsequently re-interviewed its participants every two years. The NPHS included a short form version of the Composite International Diagnostic Interview (CIDI-SF) to assess past year MDE and also collected data on participation in preventive activities. Initially, we examined whether respondents with MDE in a particular year were less likely to participate in screening during that same year. In order to assess whether MDE negatively altered the pattern of participation, those successfully screened at the baseline interview in 1994 were identified and divided into cohorts depending on their MDE status. Proportional hazard models were used to quantify the effect of MDE on subsequent participation in screening.</p> <p>Results</p> <p>No effect of MDE on participation in the three preventive activities was identified either in the cross-sectional or longitudinal analysis. Adjustment for a set of relevant covariates did not alter this result.</p> <p>Conclusion</p> <p>Whereas MDE might be expected to reduce the frequency of participation in screening activities, no evidence for this was found in the current analysis. Since people with MDE may contact the health system more frequently, this may offset any tendency of the illness itself to reduce participation in screening.</p

Discovery of Two T Dwarf Companions with the Spitzer Space Telescope

We report the discovery of T dwarf companions to the nearby stars HN Peg (G0V, 18.4 pc, ~0.3 Gyr) and HD 3651 (K0V, 11.1 pc, ~7 Gyr). During an ongoing survey of 5'x5' fields surrounding stars in the solar neighborhood with IRAC aboard the Spitzer Space Telescope, we identified these companions as candidate T dwarfs based on their mid-IR colors. Using near-IR spectra obtained with SpeX at the NASA IRTF, we confirm the presence of methane absorption that characterizes T dwarfs and measure spectral types of T2.5+/-0.5 and T7.5+/-0.5 for HN Peg B and HD 3651 B, respectively. By comparing our Spitzer data to images from 2MASS obtained several years earlier, we find that the proper motions of HN Peg B and HD 3651 B are consistent with those of the primaries, confirming their companionship. HN Peg B and HD 3651 B have angular separations of 43.2" and 42.9" from their primaries, which correspond to projected physical separations of 795 and 476 AU, respectively. A comparison of their luminosities to the values predicted by theoretical evolutionary models implies masses of 0.021+/-0.009 and 0.051+/-0.014 Msun for HN Peg B and HD 3651 B. In addition, the models imply an effective temperature for HN Peg B that is significantly lower than the values derived for other T dwarfs at similar spectral types, which is the same behavior reported by Metchev & Hillenbrand for the young late-L dwarf HD 203030 B. Thus, the temperature of the L/T transition appears to depend on surface gravity. Meanwhile, HD 3651 B is the first substellar companion directly imaged around a star that is known to harbor a close-in planet from RV surveys. The discovery of this companion supports the notion that the high eccentricities of close-in planets like the one near HD 3651 may be the result of perturbations by low-mass companions at wide separations.Comment: Astrophysical Journal, in pres