Supersonic through-flow fan assessment

A study was conducted to assess the performance potential of a supersonic through-flow fan engine for supersonic cruise aircraft. It included a mean-line analysis of fans designed to operate with in-flow velocities ranging from subsonic to high supersonic speeds. The fan performance generated was used to estimate the performance of supersonic fan engines designed for four applications: a Mach 2.3 supersonic transport, a Mach 2.5 fighter, a Mach 3.5 cruise missile, and a Mach 5.0 cruise vehicle. For each application an engine was conceptualized, fan performance and engine performance calculated, weight estimates made, engine installed in a hypothetical vehicle, and mission analysis was conducted

Giant Electron-hole Charging Energy Asymmetry in Ultra-short Carbon Nanotubes

Making full usage of bipolar transport in single-wall carbon nanotube (SWCNT) transistors could permit the development of two-in-one quantum devices with ultra-short channels. We report on clean $\sim$10 to 100 nm long suspended SWCNT transistors which display a large electron-hole transport asymmetry. The devices consist of naked SWCNT channels contacted with sections of SWCNT-under-annealed-gold. The annealed gold acts as an n-doping top gate which creates nm-sharp barriers at the junctions between the contacts and naked channel. These tunnel barriers define a single quantum dot (QD) whose charging energies to add an electron or a hole are vastly different ($e-h$ charging energy asymmetry). We parameterize the $e-h$ transport asymmetry by the ratio of the hole and electron charging energies $\eta_{e-h}$. We show that this asymmetry is maximized for short channels and small band gap SWCNTs. In a small band gap SWCNT device, we demonstrate the fabrication of a two-in-one quantum device acting as a QD for holes, and a much longer quantum bus for electrons. In a 14 nm long channel, $\eta_{e-h}$ reaches up to 2.6 for a device with a band gap of 270 meV. This strong $e-h$ transport asymmetry survives even at room temperature

Retrospective Analysis of Obstetric Sepsis Screening

This project was designed to evaluate outcomes following implementation of routine screening for sepsis in the obstetric population. A retrospective analysis of the electronic medical record of 204 women who met sepsis criteria using obstetric-adjusted systemic inflammatory response syndrome (SIRS) criteria and a source of infection was the method used. Outcomes were evaluated for neonates born to the women who developed sepsis during labor. The incidence of sepsis was 0.401 per1,000 and included those with antepartum, intrapartum, or postpartum admissions. The setting was a tertiary center with 5,075 deliveries over the study period. There were 92 (45.2%) who had sepsis, 87 (42.6%) who had severe sepsis, and 25 (12.3%) who met septic shock criteria. There were no deaths and two ICU admissions. Mean lactic acid level for women with sepsis (N=203) was 2.4 +- 1.3 mmol/L. Fourteen combinations of positive SIRS criteria were present; no combination was uniquely associated with the severity of sepsis. An Apgar score of ≤ 6 at one- and five-minutes of age was more likely when the mother developed sepsis in labor, odds ratio 12.1 (95% confidence interval, 7.86, 18.61) for the one-minute Apgar, and 3.06 (95% confidence interval 1.40, 6.75) for the five-minute Apgar score. The use of a standardized process for screening for sepsis provided for early identification and timely treatment of obstetric women with sepsis. Neonates born to women who met sepsis criteria in labor were more likely to require resuscitation at the time of birth than those born to women without sepsis

STARLIB: A Next-Generation Reaction-Rate Library for Nuclear Astrophysics

STARLIB is a next-generation, all-purpose nuclear reaction-rate library. For the first time, this library provides the rate probability density at all temperature grid points for convenient implementation in models of stellar phenomena. The recommended rate and its associated uncertainties are also included. Currently, uncertainties are absent from all other rate libraries, and, although estimates have been attempted in previous evaluations and compilations, these are generally not based on rigorous statistical definitions. A common standard for deriving uncertainties is clearly warranted. STARLIB represents a first step in addressing this deficiency by providing a tabular, up-to-date database that supplies not only the rate and its uncertainty but also its distribution. Because a majority of rates are lognormally distributed, this allows the construction of rate probability densities from the columns of STARLIB. This structure is based on a recently suggested Monte Carlo method to calculate reaction rates, where uncertainties are rigorously defined. In STARLIB, experimental rates are supplemented with: (i) theoretical TALYS rates for reactions for which no experimental input is available, and (ii) laboratory and theoretical weak rates. STARLIB includes all types of reactions of astrophysical interest to Z = 83, such as (p,g), (p,a), (a,n), and corresponding reverse rates. Strong rates account for thermal target excitations. Here, we summarize our Monte Carlo formalism, introduce the library, compare methods of correcting rates for stellar environments, and discuss how to implement our library in Monte Carlo nucleosynthesis studies. We also present a method for accessing STARLIB on the Internet and outline updated Monte Carlo-based rates.Comment: Accepted for publication in the Astrophysical Journal Supplement Series; 96 pages, 22 figure