17,975 research outputs found

    Pregnancy and Maternity Discrimination : Consultation on extending redundancy protection for women and new parents. January 2019

    Get PDF
    Black and white 8x10 acetate negativehttps://digitalmaine.com/arc_george_french_photos_f/1768/thumbnail.jp

    A Statistics-Based Method for Estimating the Soil Water Retention Curve and Unsaturated Shear Strength in Engineering Practice

    Get PDF
    Unsaturated soil mechanics is rarely applied by geotechnical engineers working within the construction industry. This could be due to a poor understanding of the subject area, a lack of suitable unsaturated testing data, or a lack of suitable procedures and tools required to apply the theory in practice. The aim of this research is to show how the soil water retention curve (SWRC) and unsaturated shear strength of a soil can be estimated using standard site investigation data and then applied to geotechnical engineering problems in practice. This includes the development of a SWRC prediction procedure using 102 soil datasets from the UNSODA database. Statistical analysis is undertaken to compare the prediction of the SWRC using the Arya and Paris (1981) model (AP), Modified Kov\'acs Model (Aubertin et al., 2003) (MK) and the Perera et al. (2005) model (PM) with the measured drying SWRC from the database. The 5\textsuperscript{th} and 95\textsuperscript{th} percentiles of the error between the predicted and measured suction (suction error) are calculated to assess the performance of each method for different soil types and later used as confidence limits for soils not included in the dataset. Analysis shows that all three SWRC predictive methods can reasonably predict the SWRC of sands, but due to a lack of plasticity data in the database, only the Arya and Paris (1981) model can be used to estimate the SWRC of cohesive soils. The SWRC estimation procedure is validated using two soil samples from the literature, a sandy clay soil and a sand soil. A method to estimate the increase in shear strength due to soil suction is presented using each predicted SWRC, along with the the upper and lower confidence limits of the SWRC, for a typical geotechnical engineering slope stability problem. The use of this research is demonstrated via a two-dimensional PLAXIS finite element model showing how the factor of safety (FoS) of the slope increases as a result of using the SWRC to estimate changes in shear strength using the Fredlund et al. (1996) and Vanapalli et al. (1996) equations. By taking soil suction into account, the FoS of the slope can be significantly increased, with an improvement of 0.24 over the simulation that ignored suction when using the SWRC estimated using the AP model. By using the predicted SWRC upper and lower confidence limits, it is shown that the estimated increase in shear strength is not highly sensitive to the choice of values of soil suction

    Abridged Autobiography of George W. French

    Get PDF
    https://digitalmaine.com/arc_george_french_papers/1000/thumbnail.jp

    Extension Stakeholder Engagement: An Exploration of Two Cases Exemplifying 21st Century Adaptions

    Get PDF
    Over the past 100 years, a number of societal trends have influenced how Cooperative Extension engages public audiences in its outreach and education efforts. These trends include rapid evolution in communication technology, greater specialization of Land-Grant University faculty, and diversification of funding sources. In response, Extension organizations have adapted their engagement approach, incorporated new technologies, modified their organizational structures, and even expanded the notion of public stakeholders to include funders, program nonparticipants, and others. This article explores the implications for future Extension efforts using two case studies‚ÄĒone which explores how a community visioning program incorporated new ways of engaging local audiences, and another which explores how an Extension business retention program used participatory action research and educational organizing approaches to strengthen participation in a research-based program

    "Banking in Transition"

    Get PDF

    Electrical microfluidic pressure gauge for elastomer microelectromechanical systems

    Get PDF
    We report on an electrical microfluidic pressure gauge. A polydimethylsiloxane microvalve closes at a characteristic applied pressure determined by the material's properties and the valve's dimensions. Hence, when the same pressure is applied to all valves of a heterogeneous valve array, some valves close while others remain open. The state of the array is combined with knowledge of the respective characteristic closing pressures of the individual valves to yield an estimate of the applied pressure. The state of each valve is obtained by electrical measurements, since the electrical resistance of the respective underlying fluid-filled channel increases by at least two orders of magnitude as the valve closes and its insulating elastomer material interrupts the electrical circuit. The overall system functions as a pressure gauge with electrical readout. This device would be a critical component in active pressure-regulation loops in future integrated microfluidic systems

    Monoenergetic Neutrinos from WIMP Annihilation in Jupiter

    Full text link
    Weakly interacting massive particles (WIMPs) can be captured by the Sun and annihilate in the core, which may result in production of kaons that can decay at rest into monoenergetic 236 MeV neutrinos. Several studies of detection of these neutrinos at DUNE have been carried out. It has been shown that if the WIMP mass is below 4 GeV, then they will evaporate prior to annihilation, suppressing the signal. Since Jupiter has a cooler core, WIMPs with masses in the 1-4 GeV range will not evaporate and can thus annihilate into monoenergetic neutrinos. We calculate the flux of these neutrinos near the surface of Jupiter and find that it is comparable to the flux at DUNE for masses above 4 GeV and substantially greater in the 1-4 GeV range. Of course, detecting these neutrinos would require a neutrino detector near Jupiter. Obviously, it will be many decades before such a detector can be built, but should direct detection experiments find a WIMP with a mass in the 1-4 GeV range, it may be one of the few ways to learn about the annihilation process. A liquid hydrogen time projection chamber might be able to get precise directional information and energy of these neutrinos (and hydrogen is plentiful in the vicinity of Jupiter). We speculate that such a detector could be placed on the far side of one of the tidally locked Amalthean moons; the moon itself would provide substantial background shielding and the surface would allow easier deployment of solar panels for power generation.Comment: 14 pages, 4 figure

    Modeling heterogeneous variance‚ÄďCovariance components in two-level models

    Get PDF
    Applications of multilevel models to continuous outcomes nearly always assume constant residual variance and constant random effects variances and covar-iances. However, modeling heterogeneity of variance can prove a useful indi-cator of model misspecification and in some educational and behavioral studies, it may even be of direct substantive interest. The purpose of this article is to review, describe, and illustrate a set of recent extensions to two-level models that allow the residual and random effects variance‚Äďcovariance components to be specified as functions of predictors. These predictors can then be entered with random coefficients to allow the Level-1 heteroscedastic relationships to vary across Level-2 units. We demonstrate by simulation that ignoring Level-2 variability in residual variances leads the Level-1 variance function regres-sion coefficients to be estimated with spurious precision. We discuss software options for fitting these extensions, and we illustrate them by reanalyzing the classic High School and Beyond data and two-level school effects models pre-sented by Raudenbush and Bryk.AQ

    Monoenergetic neutrinos from WIMP annihilations in Jupiter

    Get PDF
    Several important lines of evidence point to the existence of dark matter, but it has not yet been experimentally detected. There are several proposed candidates for what dark matter is like, the most popular being weakly interacting massive particles (WIMPs). It has been well-established in the literature that WIMPs would be captured by the Sun after scattering off of atomic nuclei to a velocity lower than the escape velocity. Over time, many WIMPs would be captured and begin to annihilate in the solar core; this would result in the production of kaons that decay at rest into monoenergetic 236 MeV neutrinos. Several studies of detection of these neutrinos at DUNE have been carried out without any successful discoveries. It has been shown that if the WIMP mass is below 4 GeV, then they will scatter back to velocities above the escape velocity and evaporate prior to annihilation; this suppresses the neutrino signal. Since Jupiter has a cooler core, WIMPs with masses in the 1-4 GeV range will not evaporate and can thus annihilate into monoenergetic neutrinos. This makes Jupiter a promising candidate source for the monoenergetic neutrinos one would expect from WIMP annihilations. Additionally, one could move a detector much closer to Jupiter than to the Sun, thereby increasing the total flux of neutrinos received per second, allowing for a deeper probing of the WIMP mass spectrum. In order to make the comparison to the Sun, I assume a simplified model of both the jovian and solar interiors and compute the rates at which WIMPs are captured, evaporate, and annihilate into neutrinos using a custom-written Fortran program. Finally, I calculate the flux of these neutrinos near the surface of Jupiter and find that it is comparable to the flux at DUNE for masses above 4 GeV and substantially greater in the 1-4 GeV range. Of course, detecting these neutrinos would require a neutrino detector near Jupiter. Obviously, it will be many decades before such a detector can be built, but should direct detection experiments find a WIMP with a mass in the 1-4 GeV range, it may be one of the few ways to learn about the annihilation process. A liquid hydrogen time projection chamber might be able to get precise directional information and energy of these neutrinos (and hydrogen is plentiful in the vicinity of Jupiter). I speculate that such a detector could be placed on the far side of one of Jupiter’s tidally locked inner moons; the moon itself would provide substantial background shielding and the surface would allow easier deployment of solar panels for power generation. I provide a quick summary of each of the four moons and evaluate their viability as a detector location based on factors such as their proximity to Jupiter, their surface activity, and their geographic features
    • ‚Ķ
    corecore