220 research outputs found
An X-ray Spectroscopic Study of the Hot Interstellar Medium Toward the Galactic Bulge
We present a detailed spectroscopic study of the hot gas toward the Galactic
bulge along the 4U 1820-303 sight line by a combination analysis of emission
and absorption spectra. In addition to the absorption lines of OVII Kalpha,
OVII Kbeta, OVIII Kalpha and NeIX Kalpha by Chandra LTGS as shown by previous
works, Suzaku detected clearly the emission lines of OVII, OVIII, NeIX and NeX
from the vicinity. We used simplified plasma models with constant temperature
and density. Evaluation of the background and foreground emission was performed
carefully, including stellar X-ray contribution based on the recent X-ray
observational results and stellar distribution simulator. If we assume that one
plasma component exists in front of 4U1820-303 and the other one at the back,
the obtained temperatures are T= 1.7 +/- 0.2 MK for the front-side plasma and
T=3.9(+0.4-0.3) MK for the backside. This scheme is consistent with a hot and
thick ISM disk as suggested by the extragalactic source observations and an
X-ray bulge around the Galactic center.Comment: 14 pages, 15 figures, accepted to be published in PASJ (Replace
figure files to fix latex problem
Triple coronary vessel disease including double vessel chronic total occlusion: Quantitative flow ratio minimizes injury of the single vessel that provides collaterals
Evaluation of heat extraction through sapphire fibers for the GW observatory KAGRA
Currently, the Japanese gravitational wave laser interferometer KAGRA is
under construction in the Kamioka mine. As one main feature, it will employ
sapphire mirrors operated at a temperature of 20K to reduce the impact from
thermal noise. To reduce seismic noise, the mirrors will also be suspended from
multi-stage pendulums. Thus the heat load deposited in the mirrors by
absorption of the circulating laser light as well as heat load from thermal
radiation will need to be extracted through the last suspension stage. This
stage will consist of four thin sapphire fibers with larger heads necessary to
connect the fibers to both the mirror and the upper stage. In this paper, we
discuss heat conductivity measurements on different fiber candidates. While all
fibers had a diameter of 1.6mm, different surface treatments and approaches to
attach the heads were analyzed. Our measurements show that fibers fulfilling
the basic KAGRA heat conductivity requirement of 5000W/m/K at 20K
are technologically feasible.Comment: 11 pages, 4 figure
Flocculation of Artemia induced by East Asian common Octopus octopus sinensis paralarvae under culture conditions
Artemia are potential food organisms for the mass culture of common octopus paralarvae but cause poor paralarval growth and mortality. To understand problems arising from Artemia use, we focused on Artemia flocculation in paralarval culture tanks; Artemia get caught up with each other, exhibit disrupted swimming, are deposited on the tank bottom and eventually die. To clarify whether paralarvae induce the flocculation of food organisms or not, we cultured newly hatched Artemia nauplii, 3-day-old metanauplii and decapod crustacean zoeae with or without paralarvae at different growth stages (weight). Flocculation occurred only when Artemia were cultured with paralarvae; metanauplii had a higher susceptibility for flocculation than nauplii. Flocculated Artemia proportion increased with increasing paralarval weight. Scanning electron microscopy revealed that flocculated metanauplii had deformed setules on their setae, with hook-shaped tips and adhesion of neighbouring tips, suggesting that flocculation may occur via a mechanism similar to the ‘hook-and-loop fastener’. As octopus paralarvae exhibit external digestion, digestive enzymes secreted by paralarvae may deform Artemia setules and result in flocculation. As flocculation did not occur when metanauplii were cultured in water in which paralarvae were cultured and then removed, causative enzymes were probably rapidly inactivated after secretion
Size and Shape Distributions of Primary Crystallites in Titania Aggregates
The primary crystallite size of titania powder relates to its properties in a number of applications. Transmission electron microscopy was used in this interlaboratory comparison (ILC) to measure primary crystallite size and shape distributions for a commercial aggregated titania powder. Data of four size descriptors and two shape descriptors were evaluated across nine laboratories. Data repeatability and reproducibility was evaluated by analysis of variance. One-third of the laboratory pairs had similar size descriptor data, but 83% of the pairs had similar aspect ratio data. Scale descriptor distributions were generally unimodal and were well-described by lognormal reference models. Shape descriptor distributions were multi-modal but data visualization plots demonstrated that the Weibull distribution was preferred to the normal distribution. For the equivalent circular diameter size descriptor, measurement uncertainties of the lognormal distribution scale and width parameters were 9.5% and 22%, respectively. For the aspect ratio shape descriptor, the measurement uncertainties of the Weibull distribution scale and width parameters were 7.0% and 26%, respectively. Both measurement uncertainty estimates and data visualizations should be used to analyze size and shape distributions of particles on the nanoscale
PE-46 The Design of the Lynx X-Ray Microcalorimeter
Lynx is an x-ray telescope, one of four large satellite mission concepts currently being studied by NASA to be the next astrophysics flagship mission after WFIRST. One of Lynx's three instruments is an imaging spectrometer consisting of an x-ray microcalorimeter behind an X-ray optic with an angular resolution of 0.5 arc-seconds and approximately 3 sq m of area at 1 keV. This instrument will provide unparalleled diagnostics of distant extended structures and in particular will allow the detailed study of the role of cosmic feedback in the evolution of the Universe. We discuss the design and read-out of the of the array configuration including a number of sub-array options for increasing the capabilities to maximize the scientific return of the Lynx observatory
500.05 Comparison Between Fractional Flow Reserve (FFR) vs. Computational Fractional Flow Reserve Derived from Three-dimensional Intravascular Ultrasound (IVUSFR) and Quantitative Flow Ratio (QFR)
BACKGROUND The determination of the ischemic status of a coronary artery by wireless physiologic assessment derived from angiography has been validated and approved in the US. However, the use ofplain angiography quantitative variables does not add much to thephysiology data since it has low correlation with fractional flowreserve (FFR) and predicts clinical outcomes poorly. Recently, a grayscale intravascular ultrasound (IVUS) derived physiology method(IVUSFR) was developed and showed a good correlation with invasiveFFR by combining the geometric advantages of IVUS with physiology.The aim of this study is to assess the coefficient of correlation (R) ofinvasive FFR compared to IVUSFR and quantitative flow ratio (QFR).METHODS Stable coronary artery disease (CAD) patients with intermediate lesions (i.e. 40?80% of diameter stenosis) were assessed by angiography and IVUS. QFR was derived from the angiography images, andIVUSFR was derived from quantitative IVUS data using computationalfluid dynamics. Coefficient of correlation (R) was used in this report.RESULTS Twenty-four patients with 34 lesions were included in theanalysis. The IVUSFR, invasive FFR, Vessel QFR fixed flow (vQFRf),and Vessel QFR contrast flow (vQFRc) values varied from 0.52 to 1.00,0.71 to 0.99, 0.55 to 1.00, and 0.34 to 1.00, respectively. The coefficient of correlation (R) of FFR vs. IVUSFR was 0.79; FFR vs. vQFRf was0.72; FFR vs. vQFRc was 0.65 (Figure).CONCLUSION Compared to invasive FFR, IVUSFR and vQFRf showed asimilar coefficient of correlation and were better than vQFR contrast flowFil: Kajita, Alexandre. Medstart; Estados UnidosFil: Bezerra, Cristiano Guedes. Universidade Federal da Bahia; BrasilFil: Ozaki, Yuichi. Medstart; Estados UnidosFil: Dan, Kazuhiro. Medstart; Estados UnidosFil: Melaku, Gebremedhin D.. Medstart; Estados UnidosFil: Pinton, Fabio A.. Universidade de Sao Paulo; BrasilFil: Falcão, Breno A. A.. Hospital of Messejana; BrasilFil: Mariani, José. Universidade de Sao Paulo; BrasilFil: Bulant, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. National Laboratory For Scientific Computing; BrasilFil: Maso Talou, Gonzalo Daniel. National Laboratory For Scientific Computing; BrasilFil: Esteves, Antonio. Universidade de Sao Paulo; BrasilFil: Blanco, Pablo Javier. National Laboratory For Scientific Computing; BrasilFil: Waksman, Ron. Medstart; Estados UnidosFil: Garcia Garcia, Hector M.. Medstart; Estados UnidosFil: Lemons, Pedro Alves. Universidade de Sao Paulo; Brasi
Data Science and Machine Learning in Education
The growing role of data science (DS) and machine learning (ML) in
high-energy physics (HEP) is well established and pertinent given the complex
detectors, large data, sets and sophisticated analyses at the heart of HEP
research. Moreover, exploiting symmetries inherent in physics data have
inspired physics-informed ML as a vibrant sub-field of computer science
research. HEP researchers benefit greatly from materials widely available
materials for use in education, training and workforce development. They are
also contributing to these materials and providing software to DS/ML-related
fields. Increasingly, physics departments are offering courses at the
intersection of DS, ML and physics, often using curricula developed by HEP
researchers and involving open software and data used in HEP. In this white
paper, we explore synergies between HEP research and DS/ML education, discuss
opportunities and challenges at this intersection, and propose community
activities that will be mutually beneficial.Comment: Contribution to Snowmass 202
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