scholarly journals Testing the ALP-photon coupling with polarization measurements of Sagittarius A⋆

2021 ◽  
Vol 2021 (03) ◽  
pp. 018
Author(s):  
Guan-Wen Yuan. ◽  
Zi-Qing Xia ◽  
Chengfeng Tang ◽  
Yaqi Zhao ◽  
Yi-Fu Cai ◽  
...  
Keyword(s):  
Polarization Measurements ◽  
Sagittarius A ◽  
Photon Coupling

Polarization measurements in raman microspectroscopy.

1989 ◽  
Vol 86 ◽  
pp. 1245-1251 ◽  
Author(s):  
Claude Bremard ◽  
Jacky Laureyns ◽  
George Turrell
Keyword(s):  
Raman Microspectroscopy ◽  
Polarization Measurements

POLARIZATION MEASUREMENTS OF TWO He I TRANSITIONS USING BEAM-TILTED-FOIL EXCITATION

1979 ◽  
Vol 40 (C1) ◽  
pp. C1-295-C1-297
Author(s):  
R. L. Brooks ◽  
E. H. Pinnington
Keyword(s):  
Polarization Measurements

scholarly journals Supernova constraints on an axion-photon-dark photon interaction

2021 ◽  
Vol 2021 (6) ◽  
Author(s):  
Anson Hook ◽  
Gustavo Marques-Tavares ◽  
Clayton Ristow
Keyword(s):  
Longitudinal Mode ◽  
Transverse Mode ◽  
The Other ◽  
Unusual Feature ◽  
Dark Sector ◽  
Longitudinal Modes ◽  
Dark Photon ◽  
Transverse Modes ◽  
Weakly Coupled ◽  
Photon Coupling

Abstract We present the supernova constraints on an axion-photon-dark photon coupling, which can be the leading coupling to dark sector models and can also lead to dramatic changes to axion cosmology. We show that the supernova bound on this coupling has two unusual features. One occurs because the scattering that leads to the trapping regime converts axions and dark photons into each other. Thus, if one of the two new particles is sufficiently massive, both production and scattering become suppressed and the bounds from bulk emission and trapped (area) emission both weaken exponentially and do not intersection The other unusual feature occurs because for light dark photons, longitudinal modes couple more weakly than transverse modes do. Since the longitudinal mode is more weakly coupled, it can still cause excessive cooling even if the transverse mode is trapped. Thus, the supernova constraints for massive dark photons look like two independent supernova bounds super-imposed on top of each other.

scholarly journals Efficiency of Organic Corrosion Inhibitors Derived from Thai-Bael Fruit Extract for Preventing Corrosion in Carbon Steels

2020 ◽  
Vol 32 (8) ◽  
pp. 2043-2050
Author(s):  
Phattarasuda Manantapong ◽  
Nattanon Chaipunya ◽  
Suttipong Wannapaiboon ◽  
Prae Chirawatkul ◽  
Worawat Wattanathana ◽  
...  
Keyword(s):  
Electrochemical Impedance Spectroscopy ◽  
Impedance Spectroscopy ◽  
Steel Surface ◽  
Electrochemical Impedance ◽  
Protective Layer ◽  
Corrosion Current ◽  
Carbon Steels ◽  
Fruit Extract ◽  
Polarization Measurements ◽  
Hcl Solution

The inhibiting action of Thai-bael fruit extract at room temperature on hot-rolled steel in 1M HCl solution was studied. The chemical functional groups of the green inhibitors were characterized by Fourier-transformed infrared spectroscopy. The electrochemical activities of steel surface were investigated through linear polarization measurements, electrochemical impedance spectroscopy, surface assessment techniques based on optical microscopy and X-ray absorption spectroscopy. Electrochemical testing samples have been prepared in the form of square plates with the size 1 × 1 cm2. The organic corrosion inhibitor extract from Thai-bael fruit has shown the smallest corrosion current density (Icorr) of 114.8 μA cm-2 and corrosion potential (Ecorr) of -424.6 mV, compared with standard Ag/AgCl electrode potential. In comparison, similar tests in the bare HCl solutions yielded Icorr = 882.4 mA cm-2 and Ecorr = -445.8 mV. The mixed-type corrosion inhibiting behaviour was evidenced in the results of the polarization measurements. Electrochemical impedance spectroscopy reveals that the resistance to charge transfer due to the presence of the extracts has been increased by about four times that of the same test on the bare HCl solution, indicating the formation of a protective layer. The adsorption of the organic molecules near the steel-electrolyte interface is evident in the decreasing double-layer capacitance with the enhancing concentration levels of the extract. This latter finding supports the displacement of the water molecules by means of the adsorption of the inhibitors on the steel surface. The optical images of steel surface before and after being immersed in HCl solution also showed pieces of evidence of corrosion retardation. XANES study as well as the linear combination fitting revealed that the samples immersed in HCl solutions with Thai-bael fruit extract possess less Fe3+ compositions. All tendencies across the four examinations indicate that Thai-bael fruit extract could potentially inhibit the corrosion reaction of steel electrodes in the acidic solution.

Linear polarization measurements by Ge(Li) detector

1969 ◽  
Vol 19 (10) ◽  
pp. 1281-1289 ◽  
Author(s):  
J. Honzátko ◽  
J. Kajfosz
Keyword(s):  
Linear Polarization ◽  
Polarization Measurements

scholarly journals Asteroid Polarimetry: A Progress Report

1971 ◽  
Vol 12 ◽  
pp. 91-94
Author(s):  
J. Veverka
Keyword(s):  
Present Status ◽  
Progress Report ◽  
Polarization Curves ◽  
Photographic Method ◽  
Polarization Measurements ◽  
Partial Data ◽  
Low Sensitivity ◽  
Photoelectric Measurements

This is a brief report on the present status of asteroid polarimetry. A detailed paper is in preparation jointly with T. Gehrels.The first polarization measurements of asteroids were made by Lyot (1934), who photographically determined the polarization curves of Ceres and Vesta. These curves are reproduced by Dollfus (1961). Unfortunately, because of the low sensitivity of the photographic method, they do not agree very well with recent photoelectric measurements.The first photoelectric polarization measurements of asteroids were made by Provin (1955) (details of this work are given by Dollfus, 1961), and in recent years this work has been extended by Gehrels (unpublished) and by Veverka (1970). To date, fairly complete polarization curves for about a dozen asteroids have been obtained, and at least partial data are available for twice that number.

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