Extensometer automatically measures elongation in elastomers

Extensometer, with a calibrated shaft, measures the elongation of elastomers and automatically records this distance on a chart. It is adaptable to almost any tensile testing machine and is fabricated at a relatively low cost

Lewis Coastal Chapel-Sites Survey: Topographic Survey 2005

This report describes the results of topographic surveys undertaken for the second year of the Lewis Coastal Chapel-sites Survey (LCCS) on four chapel-sites on the Isle of Lewis in 2005. Desktop study undertaken in the first year (2004) of the LCCS identified thirty-seven recorded and five potential chapel-sites in Lewis and its outlying islands, and this was followed up with walkover survey of sixteen sites and plane table survey of three sites. However, further, more detailed topographic survey was recommended for eight sites, and this prompted the work in 2005. In February detailed topographic survey of three sites was undertaken: Teampall Pheadair, Suainebost (Site no 4), Teampall Mhealastadh, Uig (Site no 20) and Tigh na Cailleachan Dubha, Uig (Site no 21). In May - June 2005 topographic survey of the chapel-site of St Mary’s on Eilean an Tighe, Shiant Islands (formerly known as Eilean na Cille) on the Shiant Islands (Site no 32) was also undertaken with joint funding from the Shiants Island Project (SHIP)

Performance analysis of the ascent propulsion system of the Apollo spacecraft

Activities involved in the performance analysis of the Apollo lunar module ascent propulsion system are discussed. A description of the ascent propulsion system, including hardware, instrumentation, and system characteristics, is included. The methods used to predict the inflight performance and to establish performance uncertainties of the ascent propulsion system are discussed. The techniques of processing the telemetered flight data and performing postflight performance reconstruction to determine actual inflight performance are discussed. Problems that have been encountered and results from the analysis of the ascent propulsion system performance during the Apollo 9, 10, and 11 missions are presented

Low-frequency component electric microfield distributions in plasmas

Low frequency component electric microfield distributions in plasma

Sociocultural Risk Factors for Elevated Perceived Stress among African American Smokers

Introduction: African Americans experience unique stressors that may inhibit smoking cessation and enhance relapse rates. Few studies, however, have focused on risk factors for perceived stress among treatment seekers. Because African Americans are less likely to quit compared to the larger community, understanding factors associated with perceived stress among smokers has the potential to improve intervention outcomes. This study examined psychosocial and cultural correlates of stress in a sample of African American participants in a randomized controlled trial. Methods: At baseline, participants reported demographic factors and completed assessments of smoking history, alcohol use, friend and household smoking, weight concerns, acculturation, depressive symptoms, and perceived stress (N = 325). Bivariate associations were examined, followed by multiple regression analyses to test independent relationships. The sample was comprised of mostly middle-aged males, with at least a high school education, who were single, and reported low household income. Participants were moderately nicotine dependent and smoked 18 cigarettes per day for 26 years. Results: Perceived stress was inversely associated with age (r = -.16, p = .004), education (r = -.11, p = .04), household income (r = -.11, p = .047), and positively associated with being male (r = .13, p = .02). Stress perceptions were positively related to cigarettes per day (r = .11, p = .049), nicotine dependence (r = .20, p = .001), drinking frequency (r = .15, p = .008), drinking intensity (r = .14, p=.02), and inversely related to smoking duration (r = -.12, p = .03). We found positive associations between perceived stress and household smokers (r = .18, p = .004), and friends who smoke (r = .15, p = .01). Perceived stress was also positively associated with post-cessation weight concern (r = .14, p = .01), a traditional African American cultural orientation; r = .12, p = .04), and depressive symptoms (r = .65, p Conclusion: These findings have important intervention implications. Many of the risk factors for distress among African American smokers are modifiable. Interventions should prioritize addressing depression, household smoking environment, and stress among younger smokers, in addition to managing other stress-enhancing concerns like alcohol use

Development of a bedrest muscle stress apparatus

In attempting further to define the deleterious effects of spaceflight on the human body, measurement systems and techniques were devised to determine the loss of skeletal muscle strength and tone as a result of spaceflight exposure. In order to determine how the muscle degradation process progresses with time during nonuse, a system for measuring muscle stress during bedrest was developed. The Bedrest Muscle Stress Apparatus is configured to slip snugly over the foot board of a standard hospital bed. Data collected with this device correlated well with pre- and post-bedrest data collected with the original skeletal muscle stress apparatus

Detecting Axion-Like Particles With Gamma Ray Telescopes

We propose that axion-like particles (ALPs) with a two-photon vertex, consistent with all astrophysical and laboratory bounds, may lead to a detectable signature in the spectra of high-energy gamma ray sources. This occurs as a result of gamma rays being converted into ALPs in the magnetic fields of efficient astrophysical accelerators according to the "Hillas criterion", such as jets of active galactic nuclei or hot spots of radio galaxies. The discovery of such an effect is possible by GLAST in the 1-100 GeV range and by ground based gamma ray telescopes in the TeV range.Comment: corrected typos, one plot modified, material rearranged for clarification. Conclusions unchanged. Matches version published in Phys. Rev. Let

Non-Cold Dark Matter from Primordial Black Hole Evaporation

Dark matter coupled solely gravitationally can be produced through the decay of primordial black holes in the early universe. If the dark matter is lighter than the initial black hole temperature, it could be warm enough to be subject to structure formation constraints. In this paper we perform a more precise determination of these constraints. We first evaluate the dark matter phase-space distribution, without relying on the instantaneous decay approximation. We then interface this phase-space distribution with the Boltzmann code CLASS to extract the corresponding matter power spectrum, which we find to match closely those of warm dark matter models, albeit with a different dark matter mass. This mapping allows us to extract constraints from Lyman-$\alpha$ data without the need to perform hydrodynamical simulations. We robustly rule out the possibility, consistent with previous analytic estimates, of primordial black holes having come to dominate the energy density of the universe and simultaneously given rise to all the DM through their decay. Consequences and implications for dark radiation and leptogenesis are also briefly discussed.Comment: 33 pages, 4 figure

Structure of grepafloxacin relative to activity and safety profile

A comparison of the structure of ciprofloxacin and grepafloxacin shows that the two compounds are similar, with two exceptions: grepafloxacin has a methyl group at the 5 position and a methyl group attached to the 7-piperazinyl substituent. At the 1 position, both compounds have a cyclopropyl group, which is important for potency, but limits anaerobic activity. The methylpiperazine at position 7 in grepafloxacin is associated with its enhanced Gram-positive activity and long half-life. The methyl group at R5 is also thought to enhance Gram-positive activity. Ciprofloxacin's piperazine group at the 7 position is associated with good Gram-negative activity. Grepafloxacin's Gram-negative activity is comparable to that of ciprofloxacin's against Haemophilus influenzae, Moraxella catarrhalis and enteric Gram-negative bacilli.Studies of resistance development to fluoroquinolones suggest that grepafloxacin is associated with a reduced selection of resistance in Staphylococcus aureus, which is possibly related to the inhibition or avoidance of efflux transport by NorA