7,169 research outputs found

    Development of Ambient PM 2.5 Management Strategies

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    INE/AUTC 11.2

    The Physics of Disk Winds, Jets,and X-ray Variability in GRS 1915+105

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    We present new insights about accretion and ejection physics based on joint RXTE/Chandra HETGS studies of rapid X-ray variability in GRS 1915+105. For the first time, with fast phase-resolved spectroscopy of the rho state, we are able to show that changes in the broadband X-ray spectrum (RXTE) on timescales of seconds are associated with measurable changes in absorption lines (Chandra HETGS) from the accretion disk wind. Additionally, we make a direct detection of material evaporating from the radiation-pressure-dominated inner disk. Our X-ray data thus reveal the black hole as it ejects a portion of the inner accretion flow and then drives a wind from the outer disk, all in a bizarre cycle that lasts fewer than 60 seconds but can repeat for weeks. We find that the accretion disk wind may be sufficiently massive to play an active role in GRS 1915+105, not only in quenching the jet on long timescales, but also in possibly producing or facilitating transitions between classes of X-ray variability.Comment: 3 pages, 1 Figure. Proceedings of IAU Symposium 275 (Jets at all Scales), Buenos Aires, 13-17.09.2010; eds. G. Romero, R. Sunyaev, T. Bellon

    Deflation and the international Great Depression: a productivity puzzle

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    This paper presents a dynamic, stochastic general equilibrium study of the causes of the international Great Depression. We use a fully articulated model to assess the relative contributions of deflation/monetary shocks, which are the most commonly cited shocks for the Depression, and productivity shocks. We find that productivity is the dominant shock, accounting for about 2/3 of the Depression, with the monetary shock accounting for about 1/3. The main reason deflation doesn't account for more of the Depression is because there is no systematic relationship between deflation and output during this period. Our finding that a persistent productivity shock is the key factor stands in contrast to the conventional view that a continuing sequence of unexpected deflation shocks was the major cause of the Depression. We also explore what factors might be causing the productivity shocks. We find some evidence that they are largely related to industrial activity, rather than agricultural activity, and that they are correlated with real exchange rates and non-deflationary shocks to the financial sector.Depressions ; Deflation (Finance) ; Production (Economic theory)

    Charge asymmetry in high-energy μ+μ\mu^+\mu^- photoproduction in the electric field of a heavy atom

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    The charge asymmetry in the differential cross section of high-energy μ+μ\mu^+\mu^- photoproduction in the electric field of a heavy atom is obtained. This asymmetry arises due to the Coulomb corrections to the amplitude of the process (next-to-leading term with respect to the atomic field). The deviation of the nuclear electric field from the Coulomb field at small distances is crucially important for the charge asymmetry. Though the Coulomb corrections to the total cross section are negligibly small, the charge asymmetry is measurable for selected final states of μ+\mu^+ and μ\mu^-. We further discuss the feasibility for experimental observation of this effect.Comment: 6 pages, 3 figure

    Steam Integration at Aro Academy

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    This organizational improvement plan centres around a problem of practice at a faith-based independent elementary school in Ontario. Faced with several organizational challenges including declining enrolment and pressure by stakeholders to ensure curriculum delivery remains relevant for 21st Century learners, there is a goal of embedding Science, Technology, Engineering, Arts and Math (STEAM) integrated learning in a meaningful way. The school has made physical space and has the technology available to support instructional change including a dedicated Marker Space and Robotics Room. A robotics specialist and an administrator supervising innovation have been hired to support teachers but integration in the past two years has been slow. There are divisions between the English and the faith-based teachers that are pronounced. STEAM will be a driver for design thinking and 21C skill development across both the English and the faith-based teaching groups and the Design Thinking Cycle will guide the process. Many aspects of change management are addressed, including managing resisters, conflict teams and how to implement a lateral leadership model when historically the organization has been hierarchical in nature. Using a Logic Model to identify and articulate the problem of practice and choosing transformational leadership alongside incremental change theory provides the theoretical frame for this process. The Design Thinking cycle provides the conceptual frame as it articulates the change and ultimately the goal for all stakeholders. This problem of practice seeks to build staff capacity and cohesiveness through a process of lateral leadership. Ultimately a final curricular document that outlines STEAM learning at each grade level will be created by members of the STEAM Team and staff will have built capacity. Equity issues such as religion, gender and internal bias will be made transparent and problem solving around these issues will be paramount. Ultimately, the document will be continually revised to react to the global market and as each new technology emerges onto the global landscape and job market the school must pivot and redesign the nature of the STEAM curriculum to reflect these shifts

    Tanker War: America’s First Conflict with Iran, 1987–1988

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    How many deaths were caused by the Tarawera eruption?

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    Most texts and brochures describing the Tarawera eruption of 10 June, l 886, record that it resulted in about 150 fatalities (e.g., Scott & Nairn, 1989; Ansell & Taber, 1996). Indeed, a figure of 153 deaths is recorded at the excellent new visitors' centre at the Buried Village, Te Wairoa, and in a number of other contexts. Elsewhere, numbers ranging from as few as about one hundred to possibly 'thousands' of deaths have been suggested (e.g., Houghton & Johnston, 1999)

    Cardiorespiratory requirements of the 6-min walk test in patients with left ventricular systolic disfunction and no major structural heart disease

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    The six-minute walk test (6-MWT) is widely used to assess functional status in patients with chronic heart failure (CHF). The aims of the present study were: (1) to compare metabolic gas exchange during the 6-MWT in older patients with left ventricular systolic dysfunction (LVSD) and in breathless patients with no major structural heart disease (MSHD); (2) to determine the exercise intensity of the 6-MWT relative to peak oxygen uptake; (3) to establish the accuracy and reproducibility of the Metamax 3B ergospirometer during an incremental workload. Twenty four older patients with LVSD (19 male; age 76 ± 5 years; BMI 27 ± 4), and 18 patients with no MSHD (12 male; age 75 ± 8 years; BMI 27 ± 4) attended on consecutive days at the same time. Patients completed a 6-MWT with metabolic gas exchange measurements using the Metamax 3B portable ergospirometer, and an incremental cycle ergometry test using both the Metamax 3B and Oxycon Pro metabolic cart. Patients returned and performed a second 6-MWT and an incremental treadmill test, metabolic gas exchange was measured with the Metamax 3B. In patients with LVSD, the 6-MWT was performed at a higher fraction of maximal exercise capacity (p = 0.02). The 6-MWT was performed below the anaerobic threshold in patients with LVSD (83 %) and in patients with no MSHD (61 %). The Metamax 3B showed satisfactory to high accuracy at 10 W and 20 W in patients with LVSD (r = 0.77 - 0.97, p < 0.05), and no MSHD (r = 0.76 - 0.94, p < 0.05). Metabolic gas exchange variables measured during the 6-MWT showed satisfactory to high day-to-day reproducibility in patients with LVSD (ICC = 0.75 - 0.98), but a higher variability was evident in participants with no MSHD (ICC = 0.62 - 0.97). The Metamax 3B portable ergospirometer is an accurate and reproducible device during submaximal, fixed rate exercise in older patients with LVSD and no MSHD. In elderly patients with LVSD and no MSHD, the 6-MWT should not be considered a maximal test of exercise capacity but rather a test of submaximal exercise performance. Our study demonstrates that the 6-MWT takes place at a higher proportion of peak oxygen uptake in patients with LVSD compared to those with no MSHD, and may be one reason why fatigue is a more prominent symptom in these patients
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