59 research outputs found
Correlation functions near Modulated and Rough Surfaces
In a system with long-ranged correlations, the behavior of correlation
functions is sensitive to the presence of a boundary. We show that surface
deformations strongly modify this behavior as compared to a flat surface. The
modified near surface correlations can be measured by scattering probes. To
determine these correlations, we develop a perturbative calculation in the
deformations in height from a flat surface. Detailed results are given for a
regularly patterned surface, as well as for a self-affinely rough surface with
roughness exponent . By combining this perturbative calculation in
height deformations with the field-theoretic renormalization group approach, we
also estimate the values of critical exponents governing the behavior of the
decay of correlation functions near a self-affinely rough surface. We find that
for the interacting theory, a large enough can lead to novel surface
critical behavior. We also provide scaling relations between roughness induced
critical exponents for thermodynamic surface quantities.Comment: 31 pages, 2 figure
PIK3CA mutations are common in lobular carcinoma in situ, but are not a biomarker of progression
Sample and data collection were funded by Cancer Research UK. Analysis was funded by Breast Cancer Now, the Rosetrees Trust, Guys & St Thomasâ Charity (CanHelp) and the National Institute for Health Research (NIHR) Biomedical Research Centre based at Guyâs and St. Thomasâ NHS Foundation Trust and Kingâs College London
Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world
Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic.
Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality.
Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States.
Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis.
Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection
Kaelteanlagen mit nichtazeotropen ZKM zur Abloesung der FCKW
Die Anwendung nichtazeotroper Kaeltemittel in Kaelte und Waermepumpanlagen weist energetisch guenstigere Eigenschaften aus. Dies wurde durch Prozessberechnungen von Ein- und Zweistoffkaeltemitteln bestaetigt. Die Arbeit traegt zur Loesung anlagetechnischer Probleme und der kontinuierlichen Konzentrationsbestimmung von nichtazeotropen Kaeltemitteln sowie der Regelung von Kaelteanlagen mit Kaeltemitteln bei. (VTThe use of non-azeotropic refrigerant mixtures in cooling and heat pump systems is energetically favourable. This was proved in process calculations with refrigerants and two-component refrigerant mixtures. The work helps to solve plant problems and shows ways for continuous concentration determination of non-azeotropic refrigerants as well as for the control of refrigeration system in which refrigerant mixtuers are used. (VT)SIGLEAvailable from TIB Hannover: H93B1704 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman
Near-surface x-ray critical scattering from a surface
We present the first observations of near-surface critical phenomena of a phase transition in a molecular solid showing both an order-disorder and a strong displacive component. The surface x-ray scattering experiments were performed on an single crystal (=235 K). For the order parameter they show a crossover from a power law with the bulk critical exponent ÎČ=0.3±0.05 to a surface behavior with exponent ÎČ1=0.8±0.1. From the diffuse intensity we have determined the critical exponents ηâ„=1.3±0.15, Îœ=0.5±0.15, and the correlation length =
Profile analysis of the supersatellite reflections in Labradorite â A synchrotron X-ray diffraction study
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Hanford Site River Protection Project (RPP) Tank Farm Closure
The U. S. Department of Energy, Office of River Protection and the CH2M HILL Hanford Group, Inc. are responsible for the operations, cleanup, and closure activities at the Hanford Tank Farms. There are 177 tanks overall in the tank farms, 149 single-shell tanks (see Figure 1), and 28 double-shell tanks (see Figure 2). The single-shell tanks were constructed 40 to 60 years ago and all have exceeded their design life. The single-shell tanks do not meet Resource Conservation and Recovery Act of 1976 [1] requirements. Accordingly, radioactive waste is being retrieved from the single-shell tanks and transferred to double-shell tanks for storage prior to treatment through vitrification and disposal. Following retrieval of as much waste as is technically possible from the single-shell tanks, the Office of River Protection plans to close the single-shell tanks in accordance with the Hanford Federal Facility Agreement and Consent Order [2] and the Atomic Energy Act of 1954 [3] requirements. The double-shell tanks will remain in operation through much of the cleanup mission until sufficient waste has been treated such that the Office of River Protection can commence closing the double-shell tanks. At the current time, however, the focus is on retrieving waste and closing the single-shell tanks. The single-shell tanks are being managed and will be closed in accordance with the pertinent requirements in: Resource Conservation and Recovery Act of 1976 and its Washington State-authorized Dangerous Waste Regulations [4], US DOE Order 435.1 Radioactive Waste Management [5], the National Environmental Policy Act of 1969 [6], and the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 [7]. The Hanford Federal Facility Agreement and Consent Order, which is commonly referred to as the Tri-Party Agreement or TPA, was originally signed by Department of Energy, the State of Washington, and the U. S. Environmental Protection Agency in 1989. Meanwhile, the retrieval of the waste is under way and is being conducted to achieve the completion criteria established in the Hanford Federal Facility Agreement and Consent Order
High-Order Supersatellite Reflections in Labradorite. A Synchrotron X-ray Diffraction Study
The supersatellite reflections in the feldspar mineral labradorite are related to the BĂžggild intergrowth, a lamellar structure with a periodicity of about 1500 Ă
. With high-resolution X-ray diffraction using synchrotron radiation, supersatellites up to fourth order are observed. The system is an example for a natural superstructure with high-order diffraction harmonics. The satellite intensities reflect a transverse displacement modulation with a large amplitude. The complete unit cell of labradorite is affected by the displacement. In this context, various possible displacement functions are discussed. A Fourier expansion of the displacement function that yields the best agreement between measurement and theory has nearly triangular shape. The line width of the satellites characterizes imperfections of the lamellar superstructure: It increases linearly with satellite order, which is ascribed to uncorrelated variations (FWHM = 480 Ă
) of the lamellar thickness
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