scholarly journals Determining rotational deformity in broken forearms

2003 ◽  
Vol 44 (4) ◽  
pp. 561-568 ◽  
Author(s):  
Y. M. Stokes
Keyword(s):  
Differential Calculus ◽  
Practical Problem ◽  
Rotation Angle ◽  
First Year ◽  
X Rays ◽  
Conic Sections ◽  
Rotational Deformity ◽  
X Ray ◽  
University Mathematics ◽  
First Year University

AbstractTo assess rotational deformity in a broken forearm, an orthopaedic surgeon needs to determine the amount of rotation of the radius from one or more two-dimensional x-rays of the fracture. This requires only simple first-year university mathematics — rotational transformations of ellipses plus a little differential calculus — which yields a general formula giving the rotation angle from information obtained from an x-ray. Preliminary comparisons with experimental results are excellent. This is a practical problem that may be useful to motivate the teaching of conic sections.

X-ray and radium beams in the therapy of nervous diseases

1930 ◽  
Vol 26 (2) ◽  
pp. 196-199
Author(s):  
R. Ya. Gasul
Keyword(s):  
Therapeutic Effect ◽  
Empirical Finding ◽  
Biological Action ◽  
First Year ◽  
X Rays ◽  
X Ray

It's no secret that the therapeutic effect of X-rays and radium rays was, one might say, an accidental empirical finding. This, however, did not mark the first radiotherapists (who were dermatologists) without data on the biological action of X-rays and radium rays, without an exact dosage, intuitively, in the very first year after the significant discoveries of Rontgen and Kunie, these radiant factors were initially applied in the field of dermatology (before 1902 they did not know anything about the deep action of the rays).

PROXIMA 2A: A New Micro-focus Beamline for Macromolecular Crystallography

2014 ◽  
Vol 70 (a1) ◽  
pp. C1672-C1672
Author(s):  
Denis Duran ◽  
Sebastien Le Couster ◽  
Gavin Fox ◽  
Roger Fourme ◽  
Rob Meijers ◽  
...  
Keyword(s):  
High Performance ◽  
Protein Structures ◽  
Photon Flux ◽  
First Year ◽  
X Rays ◽  
Macromolecular Crystallography ◽  
Fluorescence Detector ◽  
Beam Position ◽  
X Ray ◽  
Area Detector

PROXIMA 2A is a new micro-focus and energy tunable beamline dedicated to biological macromolecular crystallography at Synchrotron SOLEIL. The beamline officially opened in March 2013, and its first year of user operation has yielded excellent results. The X-ray source is a powerful in-vacuum U24 undulator coupled to a cryo-cooled Si[111] channel-cut monochromator and a pair of focussing bimorph mirrors in Kirpatrick-Baez configuration. This combination delivers a photon flux of over 10**12 ph/s into a focal spot of 10 μm × 5 μm (H×V FWHM), which is tunable over 6 – 15 keV. The supports of the optical elements have been designed to minimise the effects of vibrations and thermal dilations on the X-ray beam position, which is stable to within 5 microns over a day. The experimental station consists of a high performance micro-diffractometer, a cryostream, an area detector (ADSC Q315r), and an X-ray fluorescence detector. The X-ray energies for MAD experiments are directly calibrated on the sample. A robot equipped with a large 9 uni-puck dewar (CATS Irelec) is available to users for the automated transfer and screening of cryo-cooled samples. The users launch their experiments via an MXCuBE interface [1], which permits the centering of the sample, collecting of diffraction images, recording of X-ray spectra and the transfer of samples. The X-ray diffraction data are of an excellent quality, and the users readily exploit the micro-focused X-rays to select the best zones of their crystals. The first year of results from users has yielded a variety of success stories including novel protein structures resolved from crystals as small as 5 microns, as well as those solved by SAD & MAD methods. The future perspectives include automated helical and grid scans, in situ plate screening and multi-crystal merging techniques.

scholarly journals X-ray photon diagnostics at the European XFEL

2019 ◽  
Vol 26 (5) ◽  
pp. 1422-1431 ◽  
Author(s):  
Jan Grünert ◽  
Marc Planas Carbonell ◽  
Florian Dietrich ◽  
Torben Falk ◽  
Wolfgang Freund ◽  
...  
Keyword(s):  
Free Electron ◽  
Repetition Rate ◽  
Free Electron Laser ◽  
First Year ◽  
X Rays ◽  
Beam Transport ◽  
Beam Position ◽  
X Ray ◽  
Time Period ◽  
Beam Delivery

The European X-ray Free-Electron Laser (European XFEL) (Altarelli et al., 2006; Tschentscher et al., 2017), the world's largest and brightest X-ray free-electron laser (Saldin et al., 1999; Pellegrini et al., 2016), went into operation in 2017. This article describes the as-built realization of photon diagnostics for this facility, the diagnostics commissioning and their application for commissioning of the facility, and results from the first year of operation, focusing on the SASE1 beamline, which was the first to be commissioned. The commissioning consisted of pre-beam checkout, first light from the bending magnets, X-rays from single undulator segments, SASE tuning with many undulator segments, first lasing, optics alignment for FEL beam transport through the tunnel up to the experiment hutches, and finally beam delivery to first users. The beam properties assessed by photon diagnostics throughout these phases included per-pulse intensity, beam position, shape, lateral dimensions and spectral properties. During this time period, the machine provided users with up to 14 keV photon energy, 1.5 mJ pulse energy, 300 FEL pulses per train and 4.5 MHz intra-bunch train repetition rate at a 10 Hz train repetition rate. Finally, an outlook is given into the diagnostic prospects for the future.

scholarly journals Reliable application of the MATH taxonomy sheds light on assessment practices

2020 ◽  
Vol 39 (4) ◽  
pp. 281-295
Author(s):  
George Kinnear ◽  
Max Bennett ◽  
Rachel Binnie ◽  
Róisín Bolt ◽  
Yinglan Zheng
Keyword(s):  
Limited Range ◽  
Systematic Investigation ◽  
First Year ◽  
Assessment Practices ◽  
Calibration Process ◽  
University Mathematics ◽  
High Level ◽  
The University ◽  
First Year University ◽  
Insight Into

Abstract The MATH taxonomy classifies questions according to the mathematical skills required to answer them. It was created to aid the development of more balanced assessments in undergraduate mathematics and has since been used to compare different assessment regimes across school and university. To date, there has been no systematic investigation of the reliability of the taxonomy when applied by multiple coders, and it has only been applied in a limited range of contexts. In this paper, we outline a calibration process which enabled four novice coders to attain a high level of inter-rater reliability. In addition, we report on the results of applying the taxonomy to different secondary school exams and to all assessment questions in a first-year university mathematics module. The results confirm previous findings that there is a difference between the mix of skills assessed in school and university mathematics exams, although we find a notably different assessment profile in the university module than in previous work. The calibration process we describe has the potential to be used more widely, enabling reliable use of the MATH taxonomy to give insight into assessment practices.

Exosat Observations of X-Rays from Classical Novae during Outburst Stage

1987 ◽  
Vol 93 ◽  
pp. 279-279
Author(s):  
H. Ögelman ◽  
J. Krautter ◽  
K. Beuermann
Keyword(s):  
White Dwarf ◽  
Central Star ◽  
Maximum Temperature ◽  
Infrared Range ◽  
First Year ◽  
X Rays ◽  
Core Mass ◽  
X Ray ◽  
Classical Novae ◽  
Bolometric Luminosity

AbstractThe initial discovery of soft X-rays from Nova Muscae 1983 was followed by eight additional observations of the three brightest novae whose outburst stage coincided with the lifetime of EXOSAT satellite; namely three more observations of Nova Muscae 1983, three observations of Nova Vulpeculae 1984 # 1 (PW Vul), and two observations of Nova Vulpeculae 1984 # 2. Through these observations we sampled the soft X-ray light curve of classical novae from optical maximum to ~ 900 days after. The observations seem best explained by the constant bolometric luminosity model of a hot white dwarf remnant. Although the measurements suffer from limited statistics, very broad energy bandpass, and incomplete sampling of any single nova, their constraints on the theories of nova outburst are significant. One constraint is that the lifetime of the white dwarf remnant in Nova Muscae 1983 is ~ 2 to 3 years, which leads to the conclusion that the burned envelope mass Mburn should be of the order of . The second constraint is that the maximum temperature, of the white dwarf remnant should approximately be within 200 000 K to 400 000 K. We estimate that a white dwarf remnant evolving like the central star of a planetary nebula, with core mass of 0.8 to 0.9 M⊙, core luminosity of ~ 2 × 104L⊙, and envelope mass of 10−6M⊙, can explain the general characteristics of the X-ray measurements for Nova Muscae 1983. In order to have ≥ 1.1 M⊙ core mass, estimated from the early observations of bolometric luminosity in the UV to infrared range, a wind with Ṁ ≤ 5 × 10−7M⊙yr−1 appears to be necessary. The few observations of Nova Vulpeculae 1984 # 1 and Nova Vulpeculae 1984 # 2 , during the first year after outburst, give a risetime and intensity that is consistent with a constant bolometric luminosity model.

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