Volume Dynamics Propulsion System Modeling for Supersonics Vehicle Research

Under the NASA Fundamental Aeronautics Program, the Supersonics Project is working to overcome the obstacles to supersonic commercial flight. The proposed vehicles are long slim body aircraft with pronounced aero-servo-elastic modes. These modes can potentially couple with propulsion system dynamics; leading to performance challenges such as aircraft ride quality and stability. Other disturbances upstream of the engine generated from atmospheric wind gusts, angle of attack, and yaw can have similar effects. In addition, for optimal propulsion system performance, normal inlet-engine operations are required to be closer to compressor stall and inlet unstart. To study these phenomena an integrated model is needed that includes both airframe structural dynamics as well as the propulsion system dynamics. This paper covers the propulsion system component volume dynamics modeling of a turbojet engine that will be used for an integrated vehicle Aero-Propulso-Servo-Elastic model and for propulsion efficiency studies

Photometric Redshifts with Surface Brightness Priors

We use galaxy surface brightness as prior information to improve photometric redshift (photo-z) estimation. We apply our template-based photo-z method to imaging data from the ground-based VVDS survey and the space-based GOODS field from HST, and use spectroscopic redshifts to test our photometric redshifts for different galaxy types and redshifts. We find that the surface brightness prior eliminates a large fraction of outliers by lifting the degeneracy between the Lyman and 4000 Angstrom breaks. Bias and scatter are improved by about a factor of 2 with the prior for both the ground and space data. Ongoing and planned surveys from the ground and space will benefit, provided that care is taken in measurements of galaxy sizes and in the application of the prior. We discuss the image quality and signal-to-noise requirements that enable the surface brightness prior to be successfully applied.Comment: 15 pages, 13 figures, matches published versio

Photo-z Performance for Precision Cosmology

Current and future weak lensing surveys will rely on photometrically estimated redshifts of very large numbers of galaxies. In this paper, we address several different aspects of the demanding photo-z performance that will be required for future experiments, such as the proposed ESA Euclid mission. It is first shown that the proposed all-sky near-infrared photometry from Euclid, in combination with anticipated ground-based photometry (e.g. PanStarrs-2 or DES) should yield the required precision in individual photo-z of sigma(z) < 0.05(1+z) at I_AB < 24.5. Simple a priori rejection schemes based on the photometry alone can be tuned to recognise objects with wildly discrepant photo-z and to reduce the outlier fraction to < 0.25% with only modest loss of otherwise usable objects. Turning to the more challenging problem of determining the mean redshift of a set of galaxies to a precision of 0.002(1+z) we argue that, for many different reasons, this is best accomplished by relying on the photo-z themselves rather than on the direct measurement of from spectroscopic redshifts of a representative subset of the galaxies. A simple adaptive scheme based on the statistical properties of the photo-z likelihood functions is shown to meet this stringent systematic requirement. We also examine the effect of an imprecise correction for Galactic extinction and the effects of contamination by fainter over-lapping objects in photo-z determination. The overall conclusion of this work is that the acquisition of photometrically estimated redshifts with the precision required for Euclid, or other similar experiments, will be challenging but possible. (abridged)Comment: 16 pages, 11 figures; submitted to MNRA

First Responders\u27 Narratives of Drowning: Perceptions of Family and Community Impacts and Policy Implications

This is an exploratory study of the impacts of drowning death on local communities and families in the Republic of Ireland as perceived by first responders. The impact of a death may be particularly stressful. The identified population of interest were members of the Garda and first responders from Community Rescue Boats Ireland. The principal data collection method was one-to-one narrative interviews followed by a focus group. Questioning involved asking interviewees to talk about specific events rather than providing general opinions. Community identity was a source of impact, an urban or rural setting was a significant factor, social media was clearly an issue, and once the immediate incident was dealt with families did not receive much formal support. Families require the support of counseling professionals. Participants identified the need for support for search and rescue personnel and improved inter-agency collaboration. There is a need for national guidelines

The prevalence of uterine fundal pressure during the second stage of labour for women giving birth in health facilities: a systematic review and meta-analysis.

Background Uterine fundal pressure involves a birth attendant pushing on the woman’s uterine fundus to assist vaginal birth. It is used in some clinical settings, though guidelines recommend against it. This systematic review aimed to determine the prevalence of uterine fundal pressure during the second stage of labour for women giving birth vaginally at health facilities. Methods The population of interest were women who experienced labour in a health facility and in whom vaginal birth was anticipated. The primary outcome was the use of fundal pressure during second stage of labour. MEDLINE, EMBASE, CINAHL and Global Index Medicus databases were searched for eligible studies published from 1 January 2000 onwards. Meta-analysis was conducted to determine a pooled prevalence, with subgroup analyses to explore heterogeneity. Results Eighty data sets from 76 studies (n = 898,544 women) were included, reporting data from 22 countries. The prevalence of fundal pressure ranged from 0.6% to 69.2% between studies, with a pooled prevalence of 23.2% (95% CI 19.4–27.0, I2 = 99.97%). There were significant differences in prevalence between country income level (p < 0.001, prevalence highest in lower-middle income countries) and method of measuring use of fundal pressure (p = 0.001, prevalence highest in studies that measured fundal pressure based on women’s self-report). Conclusions The use of uterine fundal pressure on women during vaginal birth in health facilities is widespread. Efforts to prevent this potentially unnecessary and harmful practice are needed

In-situ Discovery of a Cluster of Refractory Grains in an Allende Ferromagnesian Chondrule

During our nano-mineralogy investigation of the Allende meteorite, we discovered a unique corundum-rich cluster of irregular micrometer-sized refractory grains in a type IA chondrule. The presence of relatively oxidized (rutile) and highly reduced (a new mineral Ti_2O_3, khamrabaevite) phases in the same cluster reflects distinctly different environments prior to incorporation of the cluster into the chondrule. To our knowledge, this is the first occurrence of such a cluster. Investigation of phases that are clearly exotic to the host chondrule and may predate its formation can provide not only important constraints on the materials present when chondrules formed and the enviroments within or outside the Protoplanetary disk, but also on the chondrule formation event. Herein we report our prelimary results on the mineralogy of these grains and the overall petrology of their host chondrule