Effect of humidity on transonic flow

An experimental investigation of the effects of humidity-induced condensation on shock/boundary-layer interaction has been conducted in a transonic wind-tunnel test. The test geometry considered was a wall-mounted bump model inserted in the test section of the wind tunnel. The formation of a λ-shape condensation shock wave was shown from schlieren visualization and resulted in a forward movement of the shock wave, reduced shock wave strength, and reduced separation. Empirical correlations of the shock wave strength and humidity/dew point temperature were established. For humidity levels below 0.15 or a dew point temperature of 268 K, the effect of humidity was negligible. The unsteady pressure measurements showed that if a condensation shock wave formed and interacted with a main shock wave, the flow becomes unsteady with periodic flow oscillations occurring at 720 Hz

VLA OH and H I Zeeman Observations of the NGC 6334 Complex

We present OH and H I Zeeman observations of the NGC 6334 complex taken with the Very Large Array. The OH absorption profiles associated with the complex are relatively narrow (del-v_FWHM ~ 3 km s^1) and single-peaked over most of the sources. The H I absorption profiles contain several blended velocity components. One of the compact continuum sources in the complex (source A) has a bipolar morphology. The OH absorption profiles toward this source display a gradient in velocity from the northern continuum lobe to the southern continuum lobe; this velocity gradient likely indicates a bipolar outflow of molecular gas from the central regions to the northern and southern lobes. Magnetic fields of the order of 200 microG have been detected toward three discrete continuum sources in the complex. Virial estimates suggest that the detected magnetic fields in these sources are of the same order as the critical magnetic fields required to support the molecular clouds associated with the sources against gravitational collapse.Comment: 14 pages, 9 postscript figures, accepted for publication in the Astrophysical Journal (ApJ), tentatively scheduled for vol. 533, Apr. 20, 2000; also available at http://www.pa.uky.edu/~sarma/RESEARCH/aps_research.htm

Search for Interstellar Water in the Translucent Molecular Cloud toward HD 154368

We report an upper limit of 9 x 10^{12} cm-2 on the column density of water in the translucent cloud along the line of sight toward HD 154368. This result is based upon a search for the C-X band of water near 1240 \AA carried out using the Goddard High Resolution Spectrograph of the Hubble Space Telescope. Our observational limit on the water abundance together with detailed chemical models of translucent clouds and previous measurements of OH along the line of sight constrain the branching ratio in the dissociative recombination of H_3O+ to form water. We find at the $3\sigma$ level that no more than 30% of dissociative recombinations of H_3O+ can lead to H_2O. The observed spectrum also yielded high-resolution observations of the Mg II doublet at 1239.9 \AA and 1240.4 \AA, allowing the velocity structure of the dominant ionization state of magnesium to be studied along the line of sight. The Mg II spectrum is consistent with GHRS observations at lower spectral resolution that were obtained previously but allow an additional velocity component to be identified.Comment: Accepted by ApJ, uses aasp

Effectiveness of motivational interviewing on health-service use and mortality: a secondary outcome analysis of the MOTIVATE-HF trial

Aims Intense health-care service use and high mortality are common in heart failure (HF) patients. This secondary analysis of the MOTIVATE-HF trial investigates the effectiveness of motivational interviewing (MI) in reducing health-care service use (e.g. emergency service use and hospitalizations) and all-cause mortality.Methods and results This study used a randomized controlled trial. Patients and caregivers were randomized to Arm 1 (MI for patients), Arm 2 (MI for patients and caregivers), or Arm 3 (control group). Data were collected at baseline and at 3, 6, 9, and 12 months. Face-to-face MI plus three telephone calls were performed in Arms 1 and 2. The sample consisted of 510 patient (median age 74 years, 58% male patients) and caregiver dyads (median age 55 years, 75% female patients). At 12 months, 16.1%, 17%, and 11.2% of patients used health-care services at least once in Arms 1, 2, and 3, respectively, without significant difference. At 3 months, 1.9%, 0.6%, and 5.1% of patients died in Arms 1, 2, and 3, respectively. Mortality was lower in Arm 2 vs. Arm 3 at 3 months [hazard ratio (HR) = 0.112, 95% CI: 0.014-0.882, P = 0.04]; no difference was found at subsequent follow-ups. Mortality was lower in Arm 1 vs. Arm 3 at 3 months but did not reach statistical significance (HR = 0.38, 95% CI: 0.104-1.414, P = 0.15).Conclusion This study suggests that MI reduces mortality in patients with HF if caregivers are included in the intervention. Further studies with a stronger intervention and longer follow-up are needed to clarify the benefits of MI on health-care service use and mortality

Double jeopardy: the influence of excessive daytime sleepiness and impaired cognition on health‐related quality of life in adults with heart failure

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106066/1/ejhfhfs054.pd

HI Narrow Line Absorption in Dark Clouds

We have used the Arecibo telescope to carry out an survey of 31 dark clouds in the Taurus/Perseus region for narrow absorption features in HI ($\lambda$ 21cm) and OH (1667 and 1665 MHz) emission. We detected HI narrow self--absorption (HINSA) in 77% of the clouds that we observed. HINSA and OH emission, observed simultaneously are remarkably well correlated. Spectrally, they have the same nonthermal line width and the same line centroid velocity. Spatially, they both peak at the optically--selected central position of each cloud, and both fall off toward the cloud edges. Sources with clear HINSA feature have also been observed in transitions of CO, \13co, \c18o, and CI. HINSA exhibits better correlation with molecular tracers than with CI. The line width of the absorption feature, together with analyses of the relevant radiative transfer provide upper limits to the kinetic temperature of the gas producing the HINSA. Some sources must have a temperature close to or lower than 10 K. The correlation of column densities and line widths of HINSA with those characteristics of molecular tracers suggest that a significant fraction of the atomic hydrogen is located in the cold, well--shielded portions of molecular clouds, and is mixed with the molecular gas. The average number density ratio [HI]/[\h2] is $1.5\times10^{-3}$. The inferred HI density appears consistent with but is slightly higher than the value expected in steady state equilibrium between formation of HI via cosmic ray destruction of H$_2$ and destruction via formation of H$_2$ on grain surfaces. The distribution and abundance of atomic hydrogen in molecular clouds is a critical test of dark cloud chemistry and structure, including the issues of grain surface reaction rates, PDRs, circulation, and turbulent diffusion.Comment: 40 pages, 10 figures, accepted by Ap

Društvo i ruralna sociologija

Background: Caregivers make an important contribution to the self-care of patients with heart failure (HF), but few instruments are available to measure this contribution. Objective: The objective of this study was to test the psychometric properties of the Caregiver Contribution to Self-care of Heart Failure Index (CC-SCHFI), an instrument derived from the Self-care of Heart Failure Index version 6.2. The CC-SCHFI measures the contribution of caregivers to the self-care maintenance and self-care management of HF patients, as well as their confidence in their ability to contribute to the patients’ HF self-care. Methods: A cross-sectional design was used to study 291 Italian caregivers whose HF patients were cared for in 17 cardiovascular centers across Italy. Caregivers completed the CC-SCHFI and a sociodemographic questionnaire. Caregivers were retested on the CC-SCHFI 2 weeks later to assess test-retest reliability. Results: Most caregivers were women (66%) with a mean age of 59 years. First- and second-order confirmatory factor analysis (CFA) for each CC-SCHFI scale showed good model fit: #2 = 37.22, P = .08, Comparative Fit Index (CFI) = 0.97, Non-Normed Fit Index (NNFI) = 0.96 for caregiver contribution to self-care maintenance (second-order CFA); #2 = 14.05, P = .12, CFI = 0.96, NNFI = 0.93 for caregiver contribution to self-care management (first-order CFA); and #2 = 10.63, P = .15, CFI = 0.99, NNFI = 0.98 for caregiver confidence in contributing to self-care (second-order CFA). The CC-SCHFI was able to discriminate statistical and clinical differences between 2 groups of caregivers who had received or not received HF self-care education. Internal consistency reliability measured by factor score determinacy was more than .80 for all factors and scales except for 1 factor in the caregiver contribution to self-care management scale (.65). Test-retest reliability computed by intraclass correlation coefficient was high (90.90) for most factors and scales. Conclusion: The CC-SCHFI showed good psychometric properties of validity and reliability and can be used to measure the contribution of caregiver to HF patient self-care

MAGIC observations of very high energy gamma-rays from HESS J1813-178

Recently, the HESS collaboration has reported the detection of gamma-ray emission above a few hundred GeV from eight new sources located close to the Galactic Plane. The source HESS J1813-178 has sparked particular interest, as subsequent radio observations imply an association with SNR G12.82-0.02. Triggered by the detection in VHE gamma-rays, a positionally coincident source has also been found in INTEGRAL and ASCA data. In this Letter we present MAGIC observations of HESS J1813-178, resulting in the detection of a differential gamma-ray flux consistent with a hard-slope power law, described as dN/(dA dt dE) = (3.3+/-0.5)*10^{-12} (E/TeV)^{-2.1+/-0.2} cm^(-2)s^(-1)TeV^(-1). We briefly discuss the observational technique used, the procedure implemented for the data analysis, and put this detection in the perspective of multifrequency observations.Comment: Accepted by ApJ Letter