منابع مشابه
Diagnostic Utility of Chest X-rays in Neonatal Respiratory Distress: Determining the Sensitivity and Specificity
Background: Chest radiography is one of the most usual diagnostic tools for respiratory distress. Objective: The purpose of this study is to assess the specificity, sensitivity and clinical value of chest radiography of neonates with respiratory distress.Patients and Methods: A descriptive- analytical study was conducted on 102 neonates that were in neonatal intensive care unit of Imam Reza and...
متن کاملSubject headings: galaxies: general—galaxies: spiral—X-rays: general—X-rays: galaxies—X-rays: ISM
We present results from the analysis of deep ROSAT HRI and PSPC observations of the spiral galaxy M81. The inferred total (0.5–2 keV band) luminosity of M81 is ∼ 3×10 ergs s, excluding the contribution from identified interlopers found within the D25 ellipse. The nucleus of the galaxy alone accounts for about 65% of this luminosity. The rest is due to 26 other X-ray sources (contributing ∼ 10%)...
متن کاملInvestigating the effect of voltage fluctuations on the beam quality of X-rays in the range energy of diagnostic radiology
The purpose of this study was to investigate the effect of voltage ripple produced by X-ray machines on the quality of X-ray rays. For this purpose, the energy spectrum from the X-ray tube manufacturer should be simulated in the range of diagnostic radiography and verified by experimental results. The statistical analysis of the results showed that there is no significant difference between sim...
متن کاملSymbiotic stars in X-rays
Until recently, symbiotic binary systems in which a white dwarf accretes from a red giant were thought to be mainly a soft X-ray population. Here we describe the detection with the X-ray Telescope (XRT) on the Swift satellite of 9 white dwarf symbiotics that were not previously known to be X-ray sources and one that was previously detected as a supersoft X-ray source. The 9 new X-ray detections...
متن کاملBlazars in hard X–rays
Although blazars are thought to emit most of their luminosity in the γ–ray band, there are subclasses of them very prominent in hard X–rays. These are the best candidates to be studied by Simbol–X. They are at the extremes of the blazar sequence, having very small or very high jet powers. The former are the class of TeV emitting BL Lacs, whose synchrotron emission often peaks at tens of keV or ...
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ژورنال
عنوان ژورنال: Scientific American
سال: 1899
ISSN: 0036-8733
DOI: 10.1038/scientificamerican01281899-19305bsupp