159 research outputs found

    Real-Time PM10 Emission Rates From Paved Roads by Measurement of Concentrations in the Vehicle\u27s Wake Using On-Board Sensors Part 1. SCAMPER Method Characterization

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    Based on emission factors derived from the AP-42 algorithm, particulate matter from paved roads has been estimated to be a major source of PM10 of geologic origin. This is an empirical formula based on upwind-downwind measurement of PM10 concentrations and is dependent solely on the silt loading of the pavement and the weight of vehicles. A number of upwind-downwind studies conducted in urban areas to validate this algorithm have been generally inconclusive because the PM10 concentration difference between upwind and downwind often is within the measurement uncertainty. In the approach presented here PM10 concentrations were measured directly behind a moving vehicle in order to improve the measurement sensitivity for estimating the emission rates for vehicles on paved roads. Optical sensors were used to measure PM10 concentrations with a time resolution of approximately 10 s. Sensors were mounted in the front of the vehicle and behind it in the well-mixed wake. A special inlet probe was designed to allow isokinetic sampling under varying speed conditions. As a first approximation the emission rate was calculated by multiplying the PM10 concentration difference between the front and rear of a moving vehicle by the frontal area of the vehicle. This technique is also useful for quickly surveying large areas and for investigating hot spots on roadways caused by greater than normal deposition of PM10 forming debris. The method is designated as SCAMPER: System for the Continuous Aerosol Measurement of Particulate Emissions from Roads. Part I describes SCAMPER development and Part II describes a comprehensive field testing of mobile methods

    A Case of Problematic Diffusion

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    Sex determination techniques have diffused rapidly in India, and are being used to detect female fetuses and subsequently to abort them. This technology has spread rapidly because it imparts knowledge that is of great value within the Indian context, and because it fits in neatly with the modernization dynamic within India, which itself has enmeshed with traditional patriarchal institutions to oppress Indian women. More research needs to be done on ways to stem the adoption of problematic innovations.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68396/2/10.1177_107554709401500301.pd

    The deuteron: structure and form factors

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    A brief review of the history of the discovery of the deuteron in provided. The current status of both experiment and theory for the elastic electron scattering is then presented.Comment: 80 pages, 33 figures, submited to Advances in Nuclear Physic

    Death and Science: The Existential Underpinnings of Belief in Intelligent Design and Discomfort with Evolution

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    The present research examined the psychological motives underlying widespread support for intelligent design theory (IDT), a purportedly scientific theory that lacks any scientific evidence; and antagonism toward evolutionary theory (ET), a theory supported by a large body of scientific evidence. We tested whether these attitudes are influenced by IDT's provision of an explanation of life's origins that better addresses existential concerns than ET. In four studies, existential threat (induced via reminders of participants' own mortality) increased acceptance of IDT and/or rejection of ET, regardless of participants' religion, religiosity, educational background, or preexisting attitude toward evolution. Effects were reversed by teaching participants that naturalism can be a source of existential meaning (Study 4), and among natural-science students for whom ET may already provide existential meaning (Study 5). These reversals suggest that the effect of heightened mortality awareness on attitudes toward ET and IDT is due to a desire to find greater meaning and purpose in science when existential threats are activated
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