Determination of the source height and anisotropy of solar hard X-rays by measurements with good time resolution

Solar Physics ◽  
1978 ◽  
Vol 59 (1) ◽  
pp. 141-144 ◽  
Author(s):  
Taeil Bai
2000 ◽  
Vol 177 ◽  
pp. 275-276 ◽  
Author(s):  
A. Dowd ◽  
W. Sisk ◽  
J. Hagen

AbstractThe WAPP is a new Pulsar Processor for Arecibo Observatory. Key features are wideband operation (100 MHz) and good time resolution (16 microseconds).


2011 ◽  
Vol 214 ◽  
pp. 122-127 ◽  
Author(s):  
Li Hua Wang ◽  
Qi Dong Zhang ◽  
Yong Hong Zhang ◽  
Kai Zhang

The short-time Fourier transform has the disadvantage that is does not localize time and frequency phenomena very well. Instead the time-frequency information is scattered which depends on the length of the window. It is not possible to have arbitrarily good time resolution simultaneously with good frequency resolution. In this paper, a new method that uses the short-time Fourier transform based on multi-window functions to enhance time-frequency resolution of signals has been proposed. Simulation and experimental results present the high performance of the proposed method.


2007 ◽  
Vol 16 (07n08) ◽  
pp. 2541-2548 ◽  
Author(s):  
◽  
YI WANG ◽  
XIAOBIN WANG

Multi-gap resistive plate camber (MRPC) has been demonstrated to have good time resolution (less than 100 ps), high detection efficiency (higher than 95%) and will be used to construct a full barrel time-of-flight (TOF) detector for the STAR experiment at RHIC. The cylindrical TOF covers a total area of approximately 64 m 2 and about 4000 MRPC modules will be produced. Tsinghua University and University of Science and Technology of China (USTC) are responsible for the STAR MRPC production. In this paper we will describe the Tsinghua and USTC MRPC production facilities. Our MRPC manufacture procedures, detector assembly and testing results are also presented.


Sensors ◽  
2020 ◽  
Vol 20 (12) ◽  
pp. 3475
Author(s):  
Andrei Nomerotski ◽  
Michael Keach ◽  
Paul Stankus ◽  
Peter Svihra ◽  
Stephen Vintskevich

The uses of a silicon-pixel camera with very good time resolution (∼nanosecond) for detecting multiple, bunched optical photons is explored. We present characteristics of the camera and describe experiments proving its counting capabilities. We use a spontaneous parametric down-conversion source to generate correlated photon pairs, and exploit the Hong-Ou-Mandel (HOM) interference effect in a fiber-coupled beam splitter to bunch the pair onto the same output fiber. It is shown that the time and spatial resolution of the camera enables independent detection of two photons emerging simultaneously from a single spatial mode.


Author(s):  
J N Chapman ◽  
W A P Nicholson

Energy dispersive x-ray microanalysis (EDX) is widely used for the quantitative determination of local composition in thin film specimens. Extraction of quantitative data is usually accomplished by relating the ratio of the number of atoms of two species A and B in the volume excited by the electron beam (nA/nB) to the corresponding ratio of detected characteristic photons (NA/NB) through the use of a k-factor. This leads to an expression of the form nA/nB = kAB NA/NB where kAB is a measure of the relative efficiency with which x-rays are generated and detected from the two species.Errors in thin film x-ray quantification can arise from uncertainties in both NA/NB and kAB. In addition to the inevitable statistical errors, particularly severe problems arise in accurately determining the former if (i) mass loss occurs during spectrum acquisition so that the composition changes as irradiation proceeds, (ii) the characteristic peak from one of the minority components of interest is overlapped by the much larger peak from a majority component, (iii) the measured ratio varies significantly with specimen thickness as a result of electron channeling, or (iv) varying absorption corrections are required due to photons generated at different points having to traverse different path lengths through specimens of irregular and unknown topography on their way to the detector.


2021 ◽  
Vol 11 (15) ◽  
pp. 6948
Author(s):  
Gabriele Cervino ◽  
Sergio Sambataro ◽  
Chiara Stumpo ◽  
Salvatore Bocchieri ◽  
Fausto Murabito ◽  
...  

The aim of this study is to demonstrate the use and the effectiveness of cephalometry and golden proportions analysis of the face in planning prosthetic treatments in totally edentulous patients. In order to apply this method, latero-lateral and posterior-anterior X-rays must be performed in addition to the common procedure. Two main concerns for totally edentulous patients are the establishment of the vertical dimension and the new position of the occlusal plane. The divine proportion analysis was carried out by the use of a golden divider. The prosthetic protocol was divided into three steps and a case was selected for better understanding. Referring to the golden relations, if the distance from the chin to the wing of the nose is 1.0, the distance from the nose to eye is 0.618. This proportion is useful and effective in determining the correct prosthetic vertical dimension. The incisal margin of the lower incisor must be positioned between Point A (A) and protuberance menti (Pm) according to the gold ratio 0.618 of the total height A-Pm. Posteriorly the occlusal plane must be placed 2 mm below the divine occlusal plane (traced from the incisal margin of lower incisors to Xi point). A prosthesis made in accordance with cephalometric parameters and divine proportions of the face helps to improve the patient’s aesthetics, function and social personality.


1918 ◽  
Vol 14 (54) ◽  
pp. 33-33
Author(s):  
P. T. Weeks
Keyword(s):  

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