494 research outputs found

    A follow-up study of the business administration graduates of the University of Scranton

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    Thesis (M.A.)--Boston University, 1949. This item was digitized by the Internet Archive

    Steady State and Transient Dynamical Systems Analysis of Uncoupled Roll Response for a Traditional Versus Advanced Hull Form

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    The two ships represented in this thesis are dramatically different in design, but both exhibit similar properties such as length and breadth. The traditional hull form is represented by a typical flare-sided design with a forward reaching bow while the advanced hull form has a modified tumblehome and a truncated bow. The difference in shapes provides an interesting problem, comparing the roll responses for these two very different vessels while keeping certain shape parameters such as length, beam, and draft constant

    Steady State and Transient Dynamical Systems Analysis of Uncoupled Roll Response for a Traditional Versus Advanced Hull Form

    Get PDF
    The two ships represented in this thesis are dramatically different in design, but both exhibit similar properties such as length and breadth. The traditional hull form is represented by a typical flare-sided design with a forward reaching bow while the advanced hull form has a modified tumblehome and a truncated bow. The difference in shapes provides an interesting problem, comparing the roll responses for these two very different vessels while keeping certain shape parameters such as length, beam, and draft constant

    The ReDistricting Game: Teaching Congressional Gerrymandering through an Online Simulation Game

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    An innovative online simulation game that spotlights the problem of gerrymandering can help students understand the congressional redistricting process

    Modeling high-energy cosmic ray induced terrestrial and atmospheric neutron flux: A lookup table

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    Under current conditions, the cosmic ray spectrum incident on the Earth is dominated by particles with energies < 1 GeV. Astrophysical sources including high energy solar flares, supernovae and gamma ray bursts produce high energy cosmic rays (HECRs) with drastically higher energies. The Earth is likely episodically exposed to a greatly increased HECR flux from such events, some of which lasting thousands to millions of years. The air showers produced by HECRs ionize the atmosphere and produce harmful secondary particles such as muons and neutrons. Neutrons currently contribute a significant radiation dose at commercial passenger airplane altitude. With higher cosmic ray energies, these effects will be propagated to ground level. This work shows the results of Monte Carlo simulations quantifying the neutron flux due to high energy cosmic rays at various primary energies and altitudes. We provide here lookup tables that can be used to determine neutron fluxes from primaries with total energies 1 GeV - 1 PeV. By convolution, one can compute the neutron flux for any arbitrary CR spectrum. Our results demonstrate that deducing the nature of primaries from ground level neutron enhancements would be very difficult.Comment: 8 pages, 3 figures, JGR - in pres

    The barycentric motion of exoplanet host stars: tests of solar spin-orbit coupling

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    Empirical evidence suggests a tantalising but unproven link between various indicators of solar activity and the barycentric motion of the Sun. The latter is exemplified by transitions between regular and more disordered motion modulated by the motions of the giant planets, and rare periods of retrograde motion with negative orbital angular momentum. An examination of the barycentric motion of exoplanet host stars, and their stellar activity cycles, has the potential of proving or disproving the Sun's motion as an underlying factor in the complex patterns of short- and long-term solar variability indices, by establishing whether such correlations exist in other planetary systems. A variety of complex patterns of barycentric motions of exoplanet host stars is demonstrated, depending on the number, masses and orbits of the planets. Each of the behavioural types proposed to correlate with solar activity are also evident in exoplanet host stars: repetitive patterns influenced by massive multiple planets, epochs of rapid change in orbital angular momentum, and intervals of negative orbital angular momentum. The study provides the basis for independent investigations of the widely-studied but unproven suggestion that the Sun's motion is somehow linked to various indicators of solar activity. We show that, because of the nature of their barycentric motions, the host stars HD168443 and HD74156 offer particularly powerful tests of this hypothesis.Comment: 7 pages, 3 figures. Accepted for publication in A&

    Atmospheric Consequences of Cosmic Ray Variability in the Extragalactic Shock Model II: Revised ionization levels and their consequences

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    It has been suggested that galactic shock asymmetry induced by our galaxy's infall toward the Virgo Cluster may be a source of periodicity in cosmic ray exposure as the solar system oscillates perpendicular to the galactic plane. Here we investigate a mechanism by which cosmic rays might affect terrestrial biodiversity, ionization and dissociation in the atmosphere, resulting in depletion of ozone and a resulting increase in the dangerous solar UVB flux on the ground, with an improved ionization background computation averaged over a massive ensemble (about 7 x 10^5) shower simulations. We study minimal and full exposure to the postulated extragalactic background. The atmospheric effects are greater than with our earlier, simplified ionization model. At the lower end of the range effects are too small to be of serious consequence. At the upper end of the range, ~6 % global average loss of ozone column density exceeds that currently experienced due to effects such as accumulated chlorofluorocarbons. The intensity is less than a nearby supernova or galactic gamma-ray burst, but the duration would be about 10^6 times longer. Present UVB enhancement from current ozone depletion ~3% is a documented stress on the biosphere, but a depletion of the magnitude found at the upper end of our range would double the global average UVB flux. For estimates at the upper end of the range of the cosmic ray variability over geologic time, the mechanism of atmospheric ozone depletion may provide a major biological stress, which could easily bring about major loss of biodiversity. Future high energy astrophysical observations will resolve the question of whether such depletion is likely.Comment: 22 pages, 5 figures, to be published in Journal of Geophysical Research--Planets. This is an update and replacement for our 2008 paper, with a much more extensive simulation of air shower ionization. Ionization effects and ozone depletion are somewhat large

    Sun's retrograde motion and violation of even-odd cycle rule in sunspot activity

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    The sum of sunspots number over an odd numbered 11 yr sunspot cycle exceeds that of its preceding even numbered cycle, and it is well known as Gnevyshev and Ohl rule (or G--O rule) after the names of the authors who discovered it in 1948. The G--O rule can be used to predict the sum of sunspot numbers of a forthcoming odd cycle from that of its preceding even cycle. But this is not always possible because occasionally the G--O rule is violated. So far no plausible reason is known either for the G--O rule or the violation of this rule. Here we showed the epochs of the violation of the G--O rule are close to the epochs of the Sun's retrograde orbital motion about the centre of mass of the solar system (i.e., the epochs at which the orbital angular momentum of the Sun is weakly negative). Using this result easy to predict the epochs of violation of the G--O rule well in advance. We also showed that the solar equatorial rotation rate determined from sunspot group data during the period 1879--2004 is correlated/anti-correlated to the Sun's orbital torque during before/after 1945. We have found the existence of a statistically significant \sim 17 yr periodicity in the solar equatorial rotation rate. The implications of these findings for understanding the mechanism behind the solar cycle and the solar-terrestrial relationship are discussed.Comment: 13 pages, 4 figures, accepted by MNRA

    Advancing the Entry-Level Practitioner: A Curricular Model of the Professional Occupational Therapy Doctoral Degree

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    The recent growth of entry-level occupational therapy doctoral (EL-OTD) programs has been met with mixed opinions from both occupational therapy educators and practitioners. These opinions occasionally have been accompanied by uncertainty about the specific curricular components that differentiate the EL-OTD from the entry-level master’s degree. In an effort to address this uncertainty, the purpose of this article is to present one example of an EL-OTD curricular model and describe its distinct educational components. This curricular model integrates recommendations for doctoral education originally proposed by Case-Smith et al. (2014) and is characterized by the following three components: 1) Advanced Coursework; 2) the Doctoral Capstone Project; and 3) the Doctoral Capstone Experience. We share the lessons learned after matriculating three cohorts of EL-OTD students and describe influences from the field of implementation science that have informed the development of our curriculum

    A Phase I trial of talazoparib in patients with advanced hematologic malignancies

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    Aim: The objective of this study was to establish the maximum tolerated dose (MTD), safety, pharmacokinetics, and anti-leukemic activity of talazoparib. Patients & methods: This Phase I, two-cohort, dose-escalation trial evaluated talazoparib monotherapy in advanced hematologic malignancies (cohort 1: acute myeloid leukemia/myelodysplastic syndrome; cohort 2: chronic lymphocytic leukemia/mantle cell lymphoma). Results: Thirty-three (cohort 1: n = 25; cohort 2: n = 8) patients received talazoparib (0.1-2.0 mg once daily). The MTD was exceeded at 2.0 mg/day in cohort 1 and at 0.9 mg/day in cohort 2. Grade ≥3 adverse events were primarily hematologic. Eighteen (54.5%) patients reported stable disease. Conclusion: Talazoparib is relatively well tolerated in hematologic malignancies, with a similar MTD as in solid tumors, and shows preliminary anti leukemic activity.Clinical trial registration: NCT01399840 (ClinicalTrials.gov)
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