Adequate aging condition for fiber Bragg grating based on simple power law model

2002 ◽  
Author(s):  
S. Ishikawa ◽  
A. Inoue ◽  
M. Harumoto ◽  
T. Enomoto ◽  
H. Kanamori
Keyword(s):  
Fiber Bragg Grating ◽  
Power Law ◽  
Bragg Grating ◽  
Power Law Model ◽  
Aging Condition ◽  
Simple Power

scholarly journals X-ray Properties of 3C 111: Separation of Primary Nuclear Emission and Jet Continuum

Universe ◽  
2020 ◽  
Vol 6 (11) ◽  
pp. 219
Author(s):  
Elena Fedorova ◽  
B.I. Hnatyk ◽  
V.I. Zhdanov ◽  
A. Del Popolo
Keyword(s):  
Accretion Disk ◽  
Power Law ◽  
Line Emission ◽  
High Energy ◽  
Power Law Model ◽  
X Ray ◽  
Additional Information ◽  
Observational Dataset ◽  
Simple Power ◽  
Photon Index

3C111 is BLRG with signatures of both FSRQ and Sy1 in X-ray spectrum. The significant X-ray observational dataset was collected for it by INTEGRAL, XMM-Newton, SWIFT, Suzaku and others. The overall X-ray spectrum of 3C 111 shows signs of a peculiarity with the large value of the high-energy cut-off typical rather for RQ AGN, probably due to the jet contamination. Separating the jet counterpart in the X-ray spectrum of 3C 111 from the primary nuclear counterpart can answer the question is this nucleus truly peculiar or this is a fake “peculiarity” due to a significant jet contribution. In view of this question, our aim is to estimate separately the accretion disk/corona and non-thermal jet emission in the 3C 111 X-ray spectra within different observational periods. To separate the disk/corona and jet contributions in total continuum, we use the idea that radio and X-ray spectra of jet emission can be described by a simple power-law model with the same photon index. This additional information allows us to derive rather accurate values of these contributions. In order to test these results, we also consider relations between the nuclear continuum and the line emission.

scholarly journals Long-term Radio Timing Observations of PSR B1509–58

2004 ◽  
Vol 218 ◽  
pp. 425-426
Author(s):  
Margaret A. Livingstone ◽  
Victoria M. Kaspi ◽  
Richard N. Manchester
Keyword(s):  
Power Law ◽  
Timing Analysis ◽  
Power Law Model ◽  
Simple Power

We present an updated phase-coherent timing solution for the young, energetic pulsar B1509–58 from twenty years of data. Using a partially phase-coherent timing analysis, we show that the second frequency derivative is changing in time, implying a third frequency derivative of This value is consistent with the simple power law model of pulsar rotation.

scholarly journals What does simple power law kinetics tell about our response to coronavirus pandemic?

2020 ◽  
Author(s):  
Prateek K. Jha
Keyword(s):  
Power Law ◽  
Time Windows ◽  
World Population ◽  
Power Law Model ◽  
Government Interventions ◽  
Social Distancing ◽  
Simple Power ◽  
Work From Home ◽  
The World ◽  
Power Law Kinetics

AbstractCoronavirus pandemic of 2019-2020 has already affected over a million people and caused over 50,000 deaths worldwide (as on April 3, 2020). Roughly half of the world population has been asked to work from home and practice social distancing as the search for a vaccine continues. Though government interventions such as lockdown and social distancing are theoretically useful, its debatable whether such interventions are effective in flattening the curve, which is ceasing or reducing the growth of infection in control populations. In this article, I present a simple power law model that enables a comparison of countries in time windows of 14 days since first coronavirus related death is reported in that country. It therefore provides means to access the efficacy of above interventions.

scholarly journals The Baryonic Tully–Fisher Relation

2004 ◽  
Vol 21 (4) ◽  
pp. 412-414 ◽  
Author(s):  
Sebastián Gurovich ◽  
Stacy S. McGaugh ◽  
Ken C. Freeman ◽  
Helmut Jerjen ◽  
Lister Staveley-Smith ◽  
...  
Keyword(s):  
Power Law ◽  
Dwarf Galaxies ◽  
Disk Galaxies ◽  
Power Law Model ◽  
Numerical Errors ◽  
Simple Power ◽  
Baryon Mass ◽  
Fisher Relation

AbstractWe validate the baryonic Tully–Fisher (TF) relation by exploring the Tully–Fisher (TF) and BTF properties of optically and Hi-selected disk galaxies. The data includes galaxies from Sakai et al. (2000) calibrator sample, McGaugh et al. (2000: M2000) I-band sample, and 18 newly acquired Hi-selected field dwarf galaxies observed with the ANU 2.3-m telescope and the ATNF Parkes telescope (Gurovich 2005a).As in M2000, we re-cast the TF and BTF relations as relationships between baryon mass and W20. First we report some numerical errors in M2000. Then, we calculate weighted bi-variate linear fits to the data, and finally we compare the fits of the intrinsically fainter dwarfs with the brighter galaxies of Sakai et al. (2000). With regards to the local calibrator disk galaxies of Sakai et al. (2000), our results suggest that the BTF relation is indeed tighter than the TF relation and that the slopes of the BTF relations are statistically flatter than the equivalent TF relations. Further, for the fainter galaxies which include the I-band M2000 and Hi-selected galaxies of Gurovich's sample, we calculate a break from a simple power law model because of what appears to be real cosmic scatter. Not withstanding this point, the BTF models are marginally better models than the equivalent TF ones with slightly smaller Χred2 values.

scholarly journals Experimental Strain Measurement Approach Using Fiber Bragg Grating Sensors for Monitoring of Railway Switches and Crossings

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3639
Author(s):  
Abdelfateh Kerrouche ◽  
Taoufik Najeh ◽  
Pablo Jaen-Sola
Keyword(s):  
Fiber Bragg Grating ◽  
Experimental Tests ◽  
Cost Effective ◽  
Measuring Method ◽  
Bragg Grating ◽  
Railway Network ◽  
System Failures ◽  
Railway Infrastructure ◽  
Train Speed ◽  
And Control

Railway infrastructure plays a major role in providing the most cost-effective way to transport freight and passengers. The increase in train speed, traffic growth, heavier axles, and harsh environments make railway assets susceptible to degradation and failure. Railway switches and crossings (S&C) are a key element in any railway network, providing flexible traffic for trains to switch between tracks (through or turnout direction). S&C systems have complex structures, with many components, such as crossing parts, frogs, switchblades, and point machines. Many technologies (e.g., electrical, mechanical, and electronic devices) are used to operate and control S&C. These S&C systems are subject to failures and malfunctions that can cause delays, traffic disruptions, and even deadly accidents. Suitable field-based monitoring techniques to deal with fault detection in railway S&C systems are sought after. Wear is the major cause of S&C system failures. A novel measuring method to monitor excessive wear on the frog, as part of S&C, based on fiber Bragg grating (FBG) optical fiber sensors, is discussed in this paper. The developed solution is based on FBG sensors measuring the strain profile of the frog of S&C to determine wear size. A numerical model of a 3D prototype was developed through the finite element method, to define loading testing conditions, as well as for comparison with experimental tests. The sensors were examined under periodic and controlled loading tests. Results of this pilot study, based on simulation and laboratory tests, have shown a correlation for the static load. It was shown that the results of the experimental and the numerical studies were in good agreement.

scholarly journals Polyconvex hyperelastic modeling of rubberlike materials

2021 ◽  
Vol 43 (7) ◽  
Author(s):  
Cyprian Suchocki ◽  
Stanisław Jemioło
Keyword(s):  
Experimental Data ◽  
Power Law ◽  
Curve Fitting ◽  
Constitutive Relations ◽  
Data Sets ◽  
Power Law Model ◽  
Stored Energy ◽  
Data Approximation ◽  
Exponential Power ◽  
Hyperelastic Models

AbstractIn this work a number of selected, isotropic, invariant-based hyperelastic models are analyzed. The considered constitutive relations of hyperelasticity include the model by Gent (G) and its extension, the so-called generalized Gent model (GG), the exponential-power law model (Exp-PL) and the power law model (PL). The material parameters of the models under study have been identified for eight different experimental data sets. As it has been demonstrated, the much celebrated Gent’s model does not always allow to obtain an acceptable quality of the experimental data approximation. Furthermore, it is observed that the best curve fitting quality is usually achieved when the experimentally derived conditions that were proposed by Rivlin and Saunders are fulfilled. However, it is shown that the conditions by Rivlin and Saunders are in a contradiction with the mathematical requirements of stored energy polyconvexity. A polyconvex stored energy function is assumed in order to ensure the existence of solutions to a properly defined boundary value problem and to avoid non-physical material response. It is found that in the case of the analyzed hyperelastic models the application of polyconvexity conditions leads to only a slight decrease in the curve fitting quality. When the energy polyconvexity is assumed, the best experimental data approximation is usually obtained for the PL model. Among the non-polyconvex hyperelastic models, the best curve fitting results are most frequently achieved for the GG model. However, it is shown that both the G and the GG models are problematic due to the presence of the locking effect.

A Fiber Bragg Grating acceleration sensor with temperature compensation

Optik ◽  
2021 ◽  
pp. 166993
Author(s):  
Xianfeng Zhao ◽  
Zhen’an Jia ◽  
Wei Fan ◽  
Wangfei Liu ◽  
Hong Gao ◽  
...  
Keyword(s):  
Fiber Bragg Grating ◽  
Temperature Compensation ◽  
Bragg Grating ◽  
Acceleration Sensor
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