Soot oxidation rates in gas turbine engines

A basis is proposed for extrapolating soot oxidation rate measurements obtained in laboratory flames to the more extreme operating conditions of gas turbine combustion chambers. The proposal is based on the observation that, within probable experimental uncertainty, the limited soot oxidation measurements correlate with the more extensive measurements of the surface oxidation rates of macroscopic samples of pyrographite. The soot oxidation rates thus determined for the conditions of a typical gas turbine combustion chamber are considerably lower than estimates which were based on simple extrapolations of the flame data

Shock-tube measurements of carbon to oxygen atom ratios for incipient soot formation with C2H2, C2H4 and C2H6 fuels

The critical atomic carbon to oxygen ratios, Phi sub C, for incipient soot formation in shock heated acetylene, ethylene, ethane/oxygen/ argon mixtures was measured over the temperature range 2000 K to 2500 K for reactant partial pressures between 0.1 and 0.4 atoms. Absorption of light from a He-Ne laser at 6328A was was used to detect soot. It was observed that the values of Phi sub C for all three fuels increased uniformly with temperature such that at the highest temperatures Phi sub C was considerably greater than unity, i.e. greater than the value of about unity at which solid carbon should have been precipitated on a thermochemical equilibrium basis. Observations were made over periods extending up to about one millisecond, which was well in excess of the time required for the major heat release of the combustion reactions. The relevance of these experimental findings to the problem of soot formation in gas turbine combustion chambers is discussed

Adolescent Health Services: Missing Opportunities

Examines the status of adolescents' health and health services, including critical needs, promising models, and components for improving disease prevention and health promotion. Recommends better primary care, coordinated policy, and expanded coverage

Unsettling the (presumed) settled: Contents and Discontents of Contraception in Aotearoa New Zealand

In January 2017, New Zealand’s medicines and medical devices safety authority, Medsafe,  announced in a press release that its Medicines Classification Committee (MCC) had recommended a reclassification of certain oral contraceptives in order for them to be made available over the counter in pharmacies.  In A/NZ, a progressive temporal narrative has been established around contraception that begins with the heroic struggle of women at the turn of the 20th Century to get access to contraception and abortion as a way to manage their reproductive lives and progresses to the guaranteed access of contraceptives to women. My intention to interrogate the contemporary contraceptive reality is not a project to undermine the historically important moves women have made here in A/NZ; but, rather, to include new places of analysis including how indigenous communities experienced the same contraceptives moments differently under the gaze of a eugenics project

Distraction, not hunger, is associated with lower mood and lower perceived work performance on fast compared to non-fast days during intermittent fasting.

Using a repeated measures design, 16 females recorded hunger, distraction, mood and perceived work performance on two consecutive fast days, on two earlier and on two subsequent consecutive non-fast days, during intermittent fasting. Using regression analyses, low positive mood was associated with higher distraction (β = -0.38, p < 0.01), and lower perceived work performance was associated with higher distraction (β = -0.50, p < 0.01) and lower positive mood (β = 0.59, p = 0.01). No associations were found with hunger (largest β = -0.11, p = 0.15). Associations between mood, perceived work performance and distraction but not hunger mirror those found in traditional dieting and suggest no benefit for attention from intermittent fasting-type regimes

Developing Multiplication Fact Fluency

Using specific components of three broad learning theories—cognitive, social-interactional, and behavioral—students in 3rd, 4th and 5th grade classrooms were given multiplication fact fluency instruction over a period of five weeks for 10-15 minutes each day. Two different approaches were utilized with two distinct groups of students for the purpose of comparing different approaches to fluency development. Results indicate that students using a strategy-based approach for fluency development by means of instructional tasks emphasizing social-interactional and cognitive theories (particularly Bruner’s theory of Modes of Representation) increased multiplication fact fluency, with a greater degree of consistency, than students using a drill-based approach emphasizing behavioristic techniques such as repetition and memorization

IRAC Observations of M81

IRAC images of M81 show three distinct morphological constituents: a smooth distribution of evolved stars with bulge, disk, and spiral arm components; a clumpy distribution of dust emission tracing the spiral arms; and a pointlike nuclear source. The bulge stellar colors are consistent with M-type giants, and the disk colors are consistent with a slightly younger population. The dust emission generally follows the blue and ultraviolet emission, but there are large areas that have dust emission without ultraviolet and smaller areas with ultraviolet but little dust emission. The former are presumably caused by extinction, and the latter may be due to cavities in the gas and dust created by supernova explosions. The nucleus appears fainter at 8 um than expected from ground-based 10 um observations made four years ago.Comment: ApJS in press (Spitzer special issue); 15 pages, 3 figures. Changes: unused references removed, numbers and labels in Table 1 change

Kinematic Masses of Super Star Clusters in M82 from High-Resolution Near-Infrared Spectroscopy

Using high-resolution (R~22,000) near-infrared (1.51 -- 1.75 microns) spectra from Keck Observatory, we measure the kinematic masses of two super star clusters in M82. Cross-correlation of the spectra with template spectra of cool evolved stars gives stellar velocity dispersions of sigma_r=15.9 +/- 0.8 km/s for MGG-9 and sigma_r=11.4 +/- 0.8 km/s for MGG-11. The cluster spectra are dominated by the light of red supergiants, and correlate most closely with template supergiants of spectral types M0 and M4.5. We fit King models to the observed profiles of the clusters in archival HST/NICMOS images to measure the half-light radii. Applying the virial theorem, we determine masses of 1.5 +/- 0.3 x 10^6 M_sun for MGG-9 and 3.5 +/- 0.7 x 10^5 M_sun for MGG-11. Population synthesis modelling suggests that MGG-9 is consistent with a standard initial mass function, whereas MGG-11 appears to be deficient in low-mass stars relative to a standard IMF. There is, however, evidence of mass segregation in the clusters, in which case the virial mass estimates would represent lower limits.Comment: 16 pages, 8 figures; ApJ, in pres

An algorithmic approach to diagnosing asthma in older patients in general practice

The document attached has been archived with permission from the editor of the Medical Journal of Australia. An external link to the publisher’s copy is included.WHAT WE NEED TO KNOW: How effective would an algorithm be in helping general practitioners diagnose asthma? What proportion of older people with undiagnosed asthma fail to recognise symptoms? What proportion of the population believe asthma does not occur in the older population? What systems or supports do GPs need to diagnose asthma more effectively? WHAT WE NEED TO DO: Work on developing a gold standard for asthma diagnosis. Develop prototype algorithms for general practice discussion. Conduct a general practice study to assess the effectiveness of an algorithm. In conjunction with GPs, develop a pilot program to increase awareness of the current asthma problem. Conduct focus-group research to identify why some people do not believe they can develop asthma for the first time in adult life. Conduct focus-group research to identify why some adults do not attribute asthma symptoms to asthma. Conduct focus groups with GPs to identify what support is needed to diagnose asthma more effectively. Consult with all stakeholders before an intervention is used. Evaluate any interventions used.Richard E Ruffin, David H Wilson, Sarah L Appleton and Robert J Adam