415 research outputs found

    Fabrication of an in-plane SU-8 cantilever with integrated strain gauge for wall shear stress measurements in fluid flows.

    Get PDF
    We present a cantilever fabricated from the polymer SU-8 for the measurement of wall shear stress in fluid flows. The pressure induced deflection of the cantilever, measured using a calibrated and integrated nichrome strain gauge, can be related to the wall shear stress on the surface. The initial degree of curvature of the cantilever can be controlled via the exposure dose, which allows a small positive deflection to be achieved, and so minimises the intrusion into the flow. Wind tunnel testing results show a sensitivity greater than 2.5 mV/Pa, with a shear stress of 0.38 Pa and excitation of 1 V

    Analysis of costs and benefits of restoration-based hazardous fuel reduction, treatments vs. no treatment: Progress report #1 June 13, 2003.

    Get PDF
    This progress report presents preliminary results of an economic analysis comparing restoration-based fuel treatments to no treatments for areas identified at high risk for fire. The with and without treatment comparison focuses on ponderosa pine and dry mixed conifer forest ecosystems in New Mexico and Arizona. The analysis provides a conservative estimate of the potential economic losses due to no action. The results for New Mexico and Arizona indicate that restoration-based fuel treatments represent a rational economic choice even if one only considers direct avoided cost of current fires suppression activities. Society could pay up to (dollars)505 dollars per acre to treat the areas of high risk, and still break even in terms of investment. This investment cost is net of any value recovered from the restoration treatment; for example if the thinning part of a restoration treatment generated (dollars)200 per acre, the total break-even investment value rises to (dollars)700/acre. This investment break-even value does not include consideration of property damage and associated losses or lost ecosystem values, such as endangered species habitat and recreation amenity values

    Cabinet-Makers' Awareness and Usage of Rainforest Cabinet Timbers in Queensland

    Get PDF
    This paper reports findings of surveys into the usage of, and attitudes to, rainforest cabinet timbers by cabinet-makers in Queensland, Australia. In determining policies to promote growing of native rainforest trees on private land, it is necessary to know the market requirements for various cabinet species. The species most in demand by cabinet-makers are identified in this paper. Suitability and availability are found to be important determinants of cabinet-maker demand for timber. The species being planted in north Queensland are not a close match with those predicted by cabinet-makers to be in greatest demand in the future

    Guide to species selection for tropical and sub-tropical plantations

    Get PDF
    2d ed. rev

    Why do people drive when they can't see clearly?

    Get PDF
    © 2018 Elsevier Ltd Purpose: Refractive blur is associated with decreased hazard perception and impairments in driving performance, but little is known about why people who have spectacles to correct their distance vision drive with uncorrected vision. Methods: We conducted six focus groups. Participants were 30 drivers (mean age 45) who reported having driven uncorrected at least twice in the past six months despite having spectacles to correct their distance vision. Focus groups were audio recorded, transcribed verbatim and analysed thematically. Results: We identified three themes. 1. Responsibility: participants did not feel obliged to drive with optimal vision and believed that others have a responsibility to ensure drivers maintain clear vision. 2. Safe Enough: participants felt safe to drive uncorrected, did not believe they need to wear spectacles to see sufficiently clearly and that they would know if their uncorrected eyesight fails to meet minimum standards. 3. Situations: participants discussed how they would drive uncorrected for short and familiar journeys, when they feel alert, in daylight and in good weather. Conclusions: Beliefs about the importance of driving with clear vision compete with the benefits of not wearing spectacles. Eyecare professionals should provide more direct advice to patients regarding the need to wear their visual correction for driving

    The anapole moment and nucleon weak interactions

    Get PDF
    From the recent measurement of parity nonconservation (PNC) in the Cs atom we have extracted the constant of the nuclear spin dependent electron-nucleon PNC interaction, κ=0.442(63)\kappa = 0.442 (63); the anapole moment constant, κa=0.364(62)\kappa_a = 0.364 (62); the strength of the PNC proton-nucleus potential, gp=7.3±1.2(exp.)±1.5(theor.)g_p = 7.3 \pm 1.2 (exp.) \pm 1.5 (theor.); the π\pi-meson-nucleon interaction constant, fπhπ1=[9.5±2.1(exp.)±3.5(theor.)]×107f_\pi \equiv h_\pi^{1} = [9.5 \pm 2.1 (exp.) \pm 3.5 (theor.)] \times 10^{-7}; and the strength of the neutron-nucleus potential, gn=1.7±0.8(exp.)±1.3(theor.)g_n = -1.7 \pm 0.8 (exp.) \pm 1.3 (theor.).Comment: Uses RevTex, 12 pages. We have added an explanation of the effect of finite nuclear siz

    Neutral weak currents in pion electroproduction on the nucleon

    Get PDF
    Parity violating asymmetry in inclusive scattering of longitudinally polarized electrons by unpolarized protons with π0\pi^0 or π+\pi^+ meson production, is calculated as a function of the momentum transfer squared Q2Q^2 and the total energy WW of the πN\pi N-system. This asymmetry, which is induced by the interference of the one-photon exchange amplitude with the parity-odd part of the Z0Z^0-exchange amplitude, is calculated for the γ(Z)+pN+π\gamma^*(Z^*)+p\to N+\pi processes (γ\gamma^* is a virtual photon and ZZ^* a virtual Z-boson) considering the Δ\Delta-contribution in the ss-channel, the standard Born contributions and vector meson (ρ\rho and ω\omega) exchanges in the tt-channel. Taking into account the known isotopic properties of the hadron electromagnetic and neutral currents, we show that the P-odd term is the sum of two contributions. The main term is model independent and it can be calculated exactly in terms of fundamental constants. It is found to be linear in Q2Q^2. The second term is a relatively small correction which is determined by the isoscalar component of the electromagnetic current. Near threshold and in the Δ\Delta-region, this isoscalar part is much smaller (in absolute value) than the isovector one: its contribution to the asymmetry depend on the polarization state (longitudinal or transverse) of the virtual photon.Comment: 30 pages 9 figure

    Large-scale pathways-based association study in amyotrophic lateral sclerosis

    No full text
    Sporadic amyotrophic lateral sclerosis (ALS), a devastating neurodegenerative disease, most likely results from complex genetic and environmental interactions. Although a number of association studies have been performed in an effort to find genetic components of sporadic ALS, most of them resulted in inconsistent findings due to a small number of genes investigated in relatively small sample sizes, while the replication of results was rarely attempted. Defects in retrograde axonal transport, vesicle trafficking and xenobiotic metabolism have been implicated in neurodegeneration and motor neuron death both in human disease and animal models. To assess the role of common genetic variation in these pathways in susceptibility to sporadic ALS, we performed a pathway-based candidate gene case-control association study with replication. Furthermore, we determined reliability of whole genome amplified DNA in a large-scale association study. In the first stage of the study, 1277 putative functional and tagging SNPs in 134 genes spanning 8.7 Mb were genotyped in 822 British sporadic ALS patients and 872 controls using whole genome amplified DNA. To detect variants with modest effect size and discriminate among false positive findings 19 SNPs showing a trend of association in the initial screen were genotyped in a replication sample of 580 German sporadic ALS patients and 361 controls. We did not detect strong evidence of association with any of the genes investigated in the discovery sample (lowest uncorrected P-value 0.00037, lowest permutation corrected P-value 0.353). None of the suggestive associations was replicated in a second sample, further excluding variants with moderate effect size. We conclude that common variation in the investigated pathways is unlikely to have a major effect on susceptibility to sporadic ALS. The genotyping efficiency was only slightly decreased (∼1%) and genotyping quality was not affected using whole genome amplified DNA. It is reliable for large scale genotyping studies of diseases such as ALS, where DNA sample collections are limited because of low disease prevalence and short survival time. © 2007 The Author(s)
    corecore