3,470 research outputs found

    General Report Session 7: Stability of Slopes and Earth Dams Under Earthquakes

    Get PDF
    The papers received for this session may be classified into five general topic areas; the number of papers in each subtopic area is shown in parentheses. 1. Slope stability analysis incorporating dynamic loading analysis methods (3) dynamic effects on soil properties (2) case study (1) 2. Dynamic response of embankment dams analysis methods (5) case studies (2) 3. Dynamic deformation analysis analysis methods adapted for a specific case (3) comparison of analysis methods (1) 4. Dynamic deformation or stability analysis incorporating pore pressure development or liquefaction considerations analysis methods (3) analysis methods developed for a specific case (2) case history of remediation (1) 5. Special studies hillside stability monitoring system (1) analysis of response of numerous dams to earthquake loading (1) A brief synopsis of each of the papers will be provided in the order indicated above, followed by an analysis and commentary on the significance of the papers

    Grand Coulee Riverbank Stabilization – Case History of the Design of Remedial Measures

    Get PDF
    Planned peaking operations at Grand Coulee Dam will cause river fluctuations of up to 1 feet daily for the authorized plant and up to 38 feet daily for a proposed plant expansion. Treatment of the historically unstable riverbanks was required to offset the destabilizing effect of the peaking operations. Consideration of the geologic history of the bank materials, estimation of future pore pressure conditions, formulation of the stabilization criteria, and the success in reducing pore pressure levels in varved clays in the bank were some of the important aspects of this project

    May Day: for orchestra

    Get PDF
    Aside from the pursuit of strictly musical ideas, a significant goal throughout the composition of this piece was in allowing my social and political interests to inform the work\u27s aesthetic properties. As a result, it occupies a hazy region between the absolute and the referential, being free from a strict narrative, yet intended to suggest symbols that are frequently associated with May 1st. The conflicting themes and imagery that surround this day have proven to be a great source of inspiration and seem well suited for the craft of composition, a creative medium that is firmly rooted in the notion of tension and release. While the pre-Christian origins of the holiday can be traced back to various points around the globe in the Eastern and Western hemispheres, its celebration has significantly expanded in meaning within the last century. While its traditional imagery crystallized into symbols of the innocent, serene, and pastoral, capitalism\u27s rise and the emergence of a new employing class furnished it with additional meaning throughout the late 19th and early 20th centuries. Due in part to its proximity to the Chicago Haymarket riots on May 4th, 1886, the holiday has since served as a surrogate memorial for the affair and has continually evolved throughout the decades into an all-purpose day of rage for the resistant and disenfranchised. Ironically, its meaning has come full circle within the last half-century, as sustainability and the search for alternative energy sources have made their way to the forefront of the public debate. It is precisely this nexus that I wish to show the listener: a point of convergence between the pastoral, industrial, and resistant

    Stability and instability in parametric resonance and quantum Zeno effect

    Get PDF
    A quantum mechanical version of a classical inverted pendulum is analyzed. The stabilization of the classical motion is reflected in the bounded evolution of the quantum mechanical operators in the Heisenberg picture. Interesting links with the quantum Zeno effect are discussed.Comment: 6 pages, 3 figure

    Declining Death Rates Reflect Progress against Cancer

    Get PDF
    BACKGROUND: The success of the "war on cancer" initiated in 1971 continues to be debated, with trends in cancer mortality variably presented as evidence of progress or failure. We examined temporal trends in death rates from all-cancer and the 19 most common cancers in the United States from 1970-2006. METHODOLOGY/PRINCIPAL FINDINGS: We analyzed trends in age-standardized death rates (per 100,000) for all cancers combined, the four most common cancers, and 15 other sites from 1970-2006 in the United States using joinpoint regression model. The age-standardized death rate for all-cancers combined in men increased from 249.3 in 1970 to 279.8 in 1990, and then decreased to 221.1 in 2006, yielding a net decline of 21% and 11% from the 1990 and 1970 rates, respectively. Similarly, the all-cancer death rate in women increased from 163.0 in 1970 to 175.3 in 1991 and then decreased to 153.7 in 2006, a net decline of 12% and 6% from the 1991 and 1970 rates, respectively. These decreases since 1990/91 translate to preventing of 561,400 cancer deaths in men and 205,700 deaths in women. The decrease in death rates from all-cancers involved all ages and racial/ethnic groups. Death rates decreased for 15 of the 19 cancer sites, including the four major cancers, with lung, colorectum and prostate cancers in men and breast and colorectum cancers in women. CONCLUSIONS/SIGNIFICANCE: Progress in reducing cancer death rates is evident whether measured against baseline rates in 1970 or in 1990. The downturn in cancer death rates since 1990 result mostly from reductions in tobacco use, increased screening allowing early detection of several cancers, and modest to large improvements in treatment for specific cancers. Continued and increased investment in cancer prevention and control, access to high quality health care, and research could accelerate this progress

    Rofecoxib and cardiovascular adverse events in adjuvant treatment of colorectal cancer

    Get PDF
    Background Selective cyclooxygenase inhibitors may retard the progression of cancer, but they have enhanced thrombotic potential. We report on cardiovascular adverse events in patients receiving rofecoxib to reduce rates of recurrence of colorectal cancer. Methods All serious adverse events that were cardiovascular thrombotic events were reviewed in 2434 patients with stage II or III colorectal cancer participating in a randomized, placebo-controlled trial of rofecoxib, 25 mg daily, started after potentially curative tumor resection and chemotherapy or radiotherapy as indicated. The trial was terminated prematurely owing to worldwide withdrawal of rofecoxib. To examine possible persistent risks, we examined cardiovascular thrombotic events reported up to 24 months after the trial was closed. Results The median duration of active treatment was 7.4 months. The 1167 patients receiving rofecoxib and the 1160 patients receiving placebo were well matched, with a median follow-up period of 33.0 months (interquartile range, 27.6 to 40.1) and 33.4 months (27.7 to 40.4), respectively. Of the 23 confirmed cardiovascular thrombotic events, 16 occurred in the rofecoxib group during or within 14 days after the treatment period, with an estimated relative risk of 2.66 (from the Cox proportional-hazards model; 95% confidence interval [CI], 1.03 to 6.86; P = 0.04). Analysis of the Antiplatelet Trialists’ Collaboration end point (the combined incidence of death from cardiovascular, hemorrhagic, and unknown causes; of nonfatal myocardial infarction; and of nonfatal ischemic and hemorrhagic stroke) gave an unadjusted relative risk of 1.60 (95% CI, 0.57 to 4.51; P = 0.37). Fourteen more cardiovascular thrombotic events, six in the rofecoxib group, were reported within the 2 years after trial closure, with an overall unadjusted relative risk of 1.50 (95% CI, 0.76 to 2.94; P = 0.24). Four patients in the rofecoxib group and two in the placebo group died from thrombotic causes during or within 14 days after the treatment period, and during the follow-up period, one patient in the rofecoxib group and five patients in the placebo group died from cardiovascular causes. Conclusions Rofecoxib therapy was associated with an increased frequency of adverse cardiovascular events among patients with a median study treatment of 7.4 months’ duration. (Current Controlled Trials number, ISRCTN98278138.

    U.S. congressional district cancer death rates

    Get PDF
    BACKGROUND: Geographic patterns of cancer death rates in the U.S. have customarily been presented by county or aggregated into state economic or health service areas. Herein, we present the geographic patterns of cancer death rates in the U.S. by congressional district. Many congressional districts do not follow state or county boundaries. However, counties are the smallest geographical units for which death rates are available. Thus, a method based on the hierarchical relationship of census geographic units was developed to estimate age-adjusted death rates for congressional districts using data obtained at county level. These rates may be useful in communicating to legislators and policy makers about the cancer burden and potential impact of cancer control in their jurisdictions. RESULTS: Mortality data were obtained from the National Center for Health Statistics (NCHS) for 1990–2001 for 50 states, the District of Columbia, and all counties. We computed annual average age-adjusted death rates for all cancer sites combined, the four major cancers (lung and bronchus, prostate, female breast, and colorectal cancer) and cervical cancer. Cancer death rates varied widely across congressional districts for all cancer sites combined, for the four major cancers, and for cervical cancer. When examined at the national level, broad patterns of mortality by sex, race and region were generally similar with those previously observed based on county and state economic area. CONCLUSION: We developed a method to generate cancer death rates by congressional district using county-level mortality data. Characterizing the cancer burden by congressional district may be useful in promoting cancer control and prevention programs, and persuading legislators to enact new cancer control programs and/or strengthening existing ones. The method can be applied to state legislative districts and other analyses that involve data aggregation from different geographic units

    Direct Gyrokinetic Comparison of Pedestal Transport in JET with Carbon and ITER-Like Walls

    Get PDF
    This paper compares the gyrokinetic instabilities and transport in two representative JET pedestals, one (pulse 78697) from the JET configuration with a carbon wall (C) and another (pulse 92432) from after the installation of JET's ITER-like Wall (ILW). The discharges were selected for a comparison of JET-ILW and JET-C discharges with good confinement at high current (3 MA, corresponding also to low ρ\rho_*) and retain the distinguishing features of JET-C and JET-ILW, notably, decreased pedestal top temperature for JET-ILW. A comparison of the profiles and heating power reveals a stark qualitative difference between the discharges: the JET-ILW pulse (92432) requires twice the heating power, at a gas rate of 1.9×1022e/s1.9 \times 10^{22}e/s, to sustain roughly half the temperature gradient of the JET-C pulse (78697), operated at zero gas rate. This points to heat transport as a central component of the dynamics limiting the JET-ILW pedestal and reinforces the following emerging JET-ILW pedestal transport paradigm, which is proposed for further examination by both theory and experiment. ILW conditions modify the density pedestal in ways that decrease the normalized pedestal density gradient a/Lna/L_n, often via an outward shift of the density pedestal. This is attributable to some combination of direct metal wall effects and the need for increased fueling to mitigate tungsten contamination. The modification to the density profile increases η=Ln/LT\eta = L_n/L_T , thereby producing more robust ion temperature gradient (ITG) and electron temperature gradient driven instability. The decreased pedestal gradients for JET-ILW (92432) also result in a strongly reduced E×BE \times B shear rate, further enhancing the ion scale turbulence. Collectively, these effects limit the pedestal temperature and demand more heating power to achieve good pedestal performance

    Quantum Zeno effect in a probed downconversion process

    Full text link
    The distorsion of a spontaneous downconvertion process caused by an auxiliary mode coupled to the idler wave is analyzed. In general, a strong coupling with the auxiliary mode tends to hinder the downconversion in the nonlinear medium. On the other hand, provided that the evolution is disturbed by the presence of a phase mismatch, the coupling may increase the speed of downconversion. These effects are interpreted as being manifestations of quantum Zeno or anti-Zeno effects, respectively, and they are understood by using the dressed modes picture of the device. The possibility of using the coupling as a nontrivial phase--matching technique is pointed out.Comment: 11 pages, 4 figure
    corecore