Modeling and simulation results on high sensitivity scattered gamma-ray emission imaging

2008 ◽  
Vol 16 (8) ◽  
pp. 1067-1076 ◽  
Author(s):  
C. Driol ◽  
M.K. Nguyen ◽  
T.T. Truong

This paper presents an overview of design, modeling and simulation of MEMS pressure sensor is using COMSOL Multiphysics V4.3b. An attempt has been made to achieve high sensitivity by providing different structures for membrane (Circular, square, rectangle & triangle) with uniform surface area and thickness. Further, simulations have been carried out with various loads ranging from 0.1 to 1MPa assigning three materials viz., InP, GaAs and Silicon. From the analyses of simulation results, it has been observed that the pressure sensor with circular membrane provided InP material found to exhibit more deformation and high sensitivity of 17.3×10-12 for 10 µm thickness and 50.8×10-12 for 7 µm thickness. The reasons for enhancement in the sensitivity are discussed in detail as function of input load, dimensional changes of diaphragm and materials addition. These studies are highly useful to check and compute pressure in various industrial and environmental conditions.


1998 ◽  
Vol 502 (1) ◽  
pp. 428-436 ◽  
Author(s):  
Igor V. Moskalenko ◽  
Werner Collmar ◽  
Volker Schonfelder

2021 ◽  
Vol 48 (4) ◽  
pp. 53-61
Author(s):  
Andrea Marin ◽  
Carey Williamson

Craps is a simple dice game that is popular in casinos around the world. While the rules for Craps, and its mathematical analysis, are reasonably straightforward, this paper instead focuses on the best ways to cheat at Craps, by using loaded (biased) dice. We use both analytical modeling and simulation modeling to study this intriguing dice game. Our modeling results show that biasing a die away from the value 1 or towards the value 5 lead to the best (and least detectable) cheating strategies, and that modest bias on two loaded dice can increase the winning probability above 50%. Our Monte Carlo simulation results provide validation for our analytical model, and also facilitate the quantitative evaluation of other scenarios, such as heterogeneous or correlated dice.


2021 ◽  
pp. 109559
Author(s):  
R.F.P. Simões ◽  
C.J. da Silva ◽  
R.L. da Silva ◽  
L.V. de Sá ◽  
R. Poledna ◽  
...  

1979 ◽  
Vol 47 (6) ◽  
pp. 1228-1233 ◽  
Author(s):  
D. S. Simon ◽  
J. F. Murray ◽  
N. C. Staub

We evaluated the attenuation of the 122 keV gamma ray of cobalt-57 across the thorax of anesthetized dogs as a method for following the time course of lung water changes in acute pulmonary edema induced by either increased microvascular permeability or increased microvascular hydrostatic pressure. The gamma rays traversed the thorax centered on the seventh rib laterally where the lung mass in the beam path was greatest. Calibration measurements in isolated lung lobes demonstrated the high sensitivity and inherent accuracy of the method over a wide range of lung water contents. In control dogs reproducibility averaged +/-3%. Increased permeability edema led to large rapid increases in the transthoracic gamma ray attenuation (TGA), while increased pressure caused an immediate, modest increase in TGA (vascular congestion) followed by a slow further increase over 2 h. There was a fairly good correlation between the increase in extravascular lung water and the change in TGA. The method is simple, safe, and noninvasive and appears to be useful for following the time course of lung water accumulation in generalized lung edema in anesthetized animals.


2018 ◽  
Vol 614 ◽  
pp. L1 ◽  
Author(s):  
A. Lähteenmäki ◽  
E. Järvelä ◽  
V. Ramakrishnan ◽  
M. Tornikoski ◽  
J. Tammi ◽  
...  

We have detected six narrow-line Seyfert 1 (NLS1) galaxies at 37 GHz that were previously classified as radio silent and two that were classified as radio quiet. These detections reveal the presumption that NLS1 galaxies labelled radio quiet or radio silent and hosted by spiral galaxies are unable to launch jets to be incorrect. The detections are a plausible indicator of the presence of a powerful, most likely relativistic jet because this intensity of emission at 37 GHz cannot be explained by, for example, radiation from supernova remnants. Additionally, one of the detected NLS1 galaxies is a newly discovered source of gamma rays and three others are candidates for future detections.


2017 ◽  
Author(s):  
S. V. Bogovalov ◽  
F. Aharonian ◽  
D. Khangulyan

2017 ◽  
Vol 12 (04) ◽  
pp. E04001-E04001
Author(s):  
G Petringa ◽  
G.A.P Cirrone ◽  
C Caliri ◽  
G Cuttone ◽  
L Giuffrida ◽  
...  

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