Balloon-borne radiometer measurement of Northern Hemisphere mid-latitude stratospheric HNO3 profiles spanning 12 years

Low-resolution atmospheric thermal emission spectra collected by balloon-borne radiometers over the time span of 1990–2002 are used to retrieve vertical profiles of HNO3, CFC-11 and CFC-12 volume mixing ratios between approximately 10 and 35 km altitude. All of the data analyzed have been collected from launches from a Northern Hemisphere mid-latitude site, during late summer, when stratospheric dynamic variability is at a minimum. The retrieval technique incorporates detailed forward modeling of the instrument and the radiative properties of the atmosphere, and obtains a best fit between modeled and measured spectra through a combination of onion-peeling and global optimization steps. The retrieved HNO3 profiles are consistent over the 12-year period, and are consistent with recent measurements by the Atmospheric Chemistry Experiment-Fourier transform spectrometer satellite instrument. This suggests that, to within the errors of the 1990 measurements, there has been no significant change in the HNO3 summer mid-latitude profile

Making automation pay - cost & throughput trade-offs in the manufacture of large composite components

The automation of complex manufacturing operations can provide significant savings over manual processes, and there remains much scope for increasing automation in the production of large scale structural composites. However the relationships between driving variables are complex, and the achievable throughput rate and corresponding cost for a given design are often not apparent. The deposition rate, number of machines required and unit production rates needed are interrelated and consequently the optimum unit cost is difficult to predict. A detailed study of the costs involved for a series of composite wing cover panels with different manufacturing requirements was undertaken. Panels were sized to account for manufacturing requirements and structural load requirements allowing both manual and automated lay-up procedures to influence design. It was discovered that the introduction of automated tape lay-up can significantly reduce material unit cost, and improve material utilisation, however higher production rates are needed to see this benefit

Home Swimming Pool Design to Improve Diving Safety

This study sought to establish home swimming pool design guidelines to minimize risk of diving injury. Using a qualitative design, interviews with representatives of home pool companies were analyzed and common themes were determined. Pool company display centers and advertising materials were also examined. The typical in-ground fiberglass home pool was described by manufacturers as 8m in length, with a constant gradient of 0.9m to 1.8–2.0m deep. Comparisons between this profile and the underwater pathways of young adults in previous studies by the authors showed that, if the dives had been performed in this typical pool, impact would have occurred for some dives. Safety features such as depth markings and signage were absent from all pools. We concluded that recreational swimmers with limited diving skills are at risk of diving injury in the typical home swimming pool. Recommendations are provided of strategies that can be implemented by home pool owners to improve pool safety

STM/STS Study on 4a X 4a Electronic Charge Order of Superconducting Bi2Sr2CaCu2O8+d

We performed low-bias STM measurements on underdoped Bi2212 crystals, and confirmed that a two-dimensional (2D) superstructure with a periodicity of four lattice constants (4a) is formed within the Cu-O plane at T<Tc. This 4a X 4a superstructure, oriented along the Cu-O bonding direction, is nondispersive and more intense in lightly doped samples with a zero temperature pseudogap (ZTPG) than in samples with a d-wave gap. The nondispersive 4a X 4a superstructure was clearly observed within the ZTPG or d-wave gap, while it tended to fade out outside the gaps. The present results provide a useful test for various models proposed for an electronic order hidden in the underdoped region of high-Tc cuprates.Comment: 4 pages, submitted to J. Phys. Soc. Jp

Psychological distress from early adulthood to early old age: Evidence from the 1946, 1958 and 1970 British birth cohorts

Background: Existing evidence on profiles of psychological distress across adulthood uses cross-sectional or longitudinal studies with short observation periods. The objective of this research was to study the profile of psychological distress within the same individuals from early adulthood to early old age across three British birth cohorts. Methods We used data from three British birth cohorts: born in 1946 (n = 3093), 1958 (n = 13 250) and 1970 (n = 12 019). The profile of psychological distress - expressed both as probability of being a clinical case or a count of symptoms based on comparable items within and across cohorts - was modelled using the multilevel regression framework. Results In both 1958 and 1970 cohorts, there was an initial drop in the probability of being a case between ages 23-26 and 33-34. Subsequently, the predicted probability of being a case increased from 12.5% at age 36 to 19.5% at age 53 in the 1946 cohort; from 8.0% at age 33 to 13.7% at age 42 in the 1958 cohort and from 15.7% at age 34 to 19.7% at age 42 in the 1970 cohort. In the 1946 cohort, there was a drop in the probability of caseness between ages 60-64 and 69 (19.5% v. 15.2%). Consistent results were obtained with the continuous version of the outcome. Conclusions Across three post-war British birth cohorts midlife appears to be a particularly vulnerable phase for experiencing psychological distress. Understanding the reasons for this will be important for the prevention and management of mental health problems. [Abstract sourced from the publisher version of the article]

Intercomparison of ground-based ozone and NO2 measurements during the MANTRA 2004 campaign

The MANTRA (Middle Atmosphere Nitrogen TRend Assessment) 2004 campaign took place in Vanscoy, Saskatchewan, Canada (52° N, 107° W) from 3 August to 15 September, 2004. In support of the main balloon launch, a suite of five zenith-sky and direct-Sun-viewing UV-visible ground-based spectrometers was deployed, primarily measuring ozone and NO2 total columns. Three Fourier transform spectrometers (FTSs) that were part of the balloon payload also performed ground-based measurements of several species, including ozone. Ground-based measurements of ozone and NO2 differential slant column densities from the zenith-viewing UV-visible instruments are presented herein. They are found to partially agree within NDACC (Network for the Detection of Atmospheric Composition Change) standards for instruments certified for process studies and satellite validation. Vertical column densities of ozone from the zenith-sky UV-visible instruments, the FTSs, a Brewer spectrophotometer, and ozonesondes are compared, and found to agree within the combined error estimates of the instruments (15%). NO2 vertical column densities from two of the UV-visible instruments are compared, and are also found to agree within combined error (15%)

The UMIST Database for Astrochemistry 2012

We present the fifth release of the UMIST Database for Astrochemistry (UDfA). The new reaction network contains 6173 gas-phase reactions, involving 467 species, 47 of which are new to this release. We have updated rate coefficients across all reaction types. We have included 1171 new anion reactions and updated and reviewed all photorates. In addition to the usual reaction network, we also now include, for download, state-specific deuterated rate coefficients, deuterium exchange reactions and a list of surface binding energies for many neutral species. Where possible, we have referenced the original source of all new and existing data. We have tested the main reaction network using a dark cloud model and a carbon-rich circumstellar envelope model. We present and briefly discuss the results of these models

Elastic Scattering Susceptibility of the High Temperature Superconductor Bi2Sr2CaCu2O8+x: A Comparison between Real and Momentum Space Photoemission Spectroscopies

The joint density of states (JDOS) of Bi2Sr2CaCu2O8+x is calculated by evaluating the autocorrelation of the single particle spectral function A(k,omega) measured from angle resolved photoemission spectroscopy (ARPES). These results are compared with Fourier transformed (FT) conductance modulations measured by scanning tunneling microscopy (STM). Good agreement between the two experimental probes is found for two different doping values examined. In addition, by comparing the FT-STM results to the autocorrelated ARPES spectra with different photon polarization, new insight on the form of the STM matrix elements is obtained. This shines new light on unsolved mysteries in the tunneling data.Comment: Revised now available at: Phys. Rev. Lett. 96, 067005 (2006

Can You Swim? Self-Report and Actual Swimming Competence Among Young Adults in Ballarat, Australia

This paper reports the Australian findings in an international study comparing self-reported and actual swimming and aquatic skills of young adults. Physical Education and Sports Sciences students (n=263) completed the “Can You Swim?” self-report survey and practical skills assessment, unaware that the practical tests replicated survey items. Relationships for comparisons between practical tests and their matched survey item were weak, indicating participants had inaccurate perceptions of their own swimming skills. Typically, they underestimated their competence in terms of distance and fundamental aquatic skills. Understanding of what constitutes different levels of swimming ability was poor, for example, most participants identified as average or good to excellent swimmers, but more than half of self-identified average swimmers, and 20% of good to excellent swimmers, estimated they could complete \u3c100m of continuous swimming. The implications of study findings for drowning prevention and the need for further research are discussed