scholarly journals Physical properties of the gamma-ray binary LS 5039 through low- and high-frequency radio observations

2015 ◽  
Vol 451 (1) ◽  
pp. 59-73 ◽  
Author(s):  
B. Marcote ◽  
M. Ribo ◽  
J. M. Paredes ◽  
C. H. Ishwara-Chandra
Keyword(s):  
Physical Properties ◽  
High Frequency ◽  
Gamma Ray ◽  
Radio Observations

CdTe-based crystals with Mg, Se, or Mn as materials for X and gamma ray detectors: Selected physical properties

2021 ◽  
pp. 100543
Author(s):  
Andrzej Mycielski ◽  
Aneta Wardak ◽  
Dominika Kochanowska ◽  
Marta Witkowska-Baran ◽  
Michał Szot ◽  
...  
Keyword(s):  
Physical Properties ◽  
Gamma Ray ◽  
Gamma Ray Detectors

Bayesian deconvolution of gamma‐ray logs

Geophysics ◽  
1987 ◽  
Vol 52 (11) ◽  
pp. 1535-1546 ◽  
Author(s):  
Ping Sheng ◽  
Benjamin White ◽  
Balan Nair ◽  
Sandra Kerford
Keyword(s):  
High Frequency ◽  
Gamma Ray ◽  
Simulated Data ◽  
Field Measurements ◽  
Bayesian Optimization ◽  
Frequency Noise ◽  
High Frequency Noise ◽  
Data Application ◽  
Gamma Ray Detector ◽  
Gamma Ray Log

The spatial resolution of gamma‐ray logs is defined by the length 𝓁 of the gamma‐ray detector. To resolve thin beds whose thickness is less than 𝓁, it is generally desirable to deconvolve the data to reduce the averaging effect of the detector. However, inherent in the deconvolution operation is an amplification of high‐frequency noise, which can be a detriment to the intended goal of increased resolution. We propose a Bayesian statistical approach to gamma‐ray log deconvolution which is based on optimization of a probability function which takes into account the statistics of gamma‐ray log measurements as well as the empirical information derived from the data. Application of this method to simulated data and to field measurements shows that it is effective in suppressing high‐frequency noise encountered in the deconvolution of gamma‐ray logs. In particular, a comparison with the least‐squares deconvolution approach indicates that the incorporation of physical and statistical information in the Bayesian optimization process results in optimal filtering of the deconvolved results.

Gamma-Ray Vulcanization of Rubber

1957 ◽  
Vol 30 (2) ◽  
pp. 380-392
Author(s):  
S. D. Gehman ◽  
I. Auerbach
Keyword(s):  
Physical Properties ◽  
Industrial Development ◽  
Industrial Revolution ◽  
Gamma Ray ◽  
Average Molecular Weight ◽  
Industrial Process ◽  
The United States ◽  
Chemical Research ◽  
Research Activity ◽  
Weight Variation

Abstract Vulcanization is the industrial process which transforms rubber from a soft, sticky, readily molded plastic to the highly elastic material familiar to everyone from innumerable uses. It was discovered by Charles Goodyear in 1839 and was one of the series of crucial inventions which started the United States on its industrial revolution in the nineteenth century. The automotive direction of this industrial development has accentuated the importance of rubber in succeeding years. This year the worldwide product volume to which vulcanization will be applied will exceed two and a half million tons. It is readily understood that vulcanization is now a highly developed process, the resultant of many improvements and developments over the course of a century of competitive use. Goodyear's original conception involved simply the heating of rubber with sulfur. The recognition of the chemical nature of the process was followed by the discovery of materials which, when added to the system, accelerated the reaction tremendously, allowed it to be carried out at lower temperatures, and improved profoundly the physical properties, uniformity, and aging resistance of the rubber. Such chemical vulcanizing systems are now applied in great variety. Many ways are known for vulcanizing rubber without using any sulfur, but they are of relatively minor commerical importance. Some of the synthetic rubbers require rather unique systems for vulcanization. There is continuous, intensive chemical research activity to find still better ways of vulcanizing rubber. So with gamma-ray vulcanization, it will be necessary to show some very tangible advantages to find even a few specialized applications. The idea of vulcanizing rubber by exposure to energetic radiation is not new. A patent issued to E. B. Newton in 1933 claimed the vulcanization of rubber by short exposures to 250-kV cathode rays. Effects of pile irradiation on uncured elastomers were studied by Davidson and Geib. Numerous investigations of the effects of radiation on the physical properties of plastics are listed in the bibliography prepared by Sun. Gehman and Hobbs observed the vulcanization of rubber by intense gamma radiation. Jackson and Hale measured the physical properties of rubber-filler mixtures as a function of the radiation dose from a strong Co60 source for a variety of elastomers. Cross-linking of rubber by pile irradiation was studied in a quantitative way by Charlesby. He emphasized the usefulness of radiation crosslinking as a means for studying the average molecular weight, variation of the gel fraction, and the changes in properties of rubber as the degree of crosslinking is varied.

scholarly journals Radio counterparts of gamma-ray pulsars

2012 ◽  
Vol 8 (S291) ◽  
pp. 87-92
Author(s):  
L. Guillemot
Keyword(s):  
Gamma Ray ◽  
Population Studies ◽  
Radio Observations ◽  
Large Area ◽  
Millisecond Pulsars ◽  
Follow Up Studies ◽  
First Time

AbstractObservations of pulsars with the Large Area Telescope (LAT) on the Fermi satellite have revolutionized our view of the gamma-ray pulsar population. For the first time, a large number of young gamma-ray pulsars have been discovered in blind searches of the LAT data. More generally, the LAT has discovered many new gamma-ray sources whose properties suggest that they are powered by unknown pulsars. Radio observations of gamma-ray sources have been key to the success of pulsar studies with the LAT. For example, radio observations of LAT-discovered pulsars provide constraints on the relative beaming fractions, which are crucial for pulsar population studies. Also, radio searches of LAT sources with no known counterparts have been very efficient, with the discovery of over forty millisecond pulsars. I review radio follow-up studies of LAT-discovered pulsars and unidentified sources, and discuss some of the implications of the results.

High frequency radio observations of Seyfert galaxies

1978 ◽  
Vol 83 ◽  
pp. 566 ◽  
Author(s):  
W. H. McCutcheon ◽  
P. C. Gregory
Keyword(s):  
High Frequency ◽  
Seyfert Galaxies ◽  
Radio Observations

scholarly journals The Radio-Gamma-Ray Connection: the Radio Properties of Gamma-Ray-Bright Blazars

1996 ◽  
Vol 175 ◽  
pp. 283-284 ◽  
Author(s):  
M. F. Aller ◽  
H. D. Aller ◽  
P. A. Hughes
Keyword(s):  
Gamma Ray ◽  
Causal Connection ◽  
Radio Observations ◽  
Significance Level ◽  
High Significance ◽  
Γ Ray ◽  
The Times

Forty AGN have been detected at high significance level by EGRET in the γ-ray band. Previous studies based on radio observations near or at the times of the EGRET detections suggest that there is a causal connection between individual events in these two wavebands. Here we examine the question of whether the cm-λ and the γ-ray activity are related.

Application of instantaneous-frequency attribute and gamma-ray wireline logs in the delineation of lithology in Serbin field, Southeast Texas: A case study

2018 ◽  
Vol 6 (4) ◽  
pp. T1023-T1043 ◽  
Author(s):  
Osareni C. Ogiesoba ◽  
William A. Ambrose ◽  
Robert G. Loucks
Keyword(s):  
Instantaneous Frequency ◽  
Acoustic Impedance ◽  
High Frequency ◽  
Gamma Ray ◽  
Low Frequency ◽  
High Porosity ◽  
Southeastern Part ◽  
High Gamma ◽  
Southeast Texas ◽  
Frequency Map

Although Serbin field in Southeast Texas was discovered in 1987, lithologic and petrophysical properties in the southeastern part of the field have not been fully evaluated. We have generated instantaneous frequency from 3D seismic data and predicted gamma-ray response volume from seismic attributes. By extracting maps of the instantaneous frequency and gamma-ray response along interpreted horizons, and crossplotting the instantaneous frequency against gamma-ray logs and integrating core data, we generated lithology maps to identify shale-prone zones that stratigraphically trapped hydrocarbons in the southeastern part of the field. We determine that Serbin field is separated into two areas: (1) a high-frequency, high-gamma-ray, and high-acoustic-impedance area in the northwest and (2) a low-frequency, low-gamma-ray, and low-acoustic-impedance area located in the southeast. By developing a lithologic map and relating it to the corresponding instantaneous-frequency map and log data, we also find that the southeastern part of the field can be divided into three zones: (1) zone 1, composed of approximately 0.7–2.7 m (approximately 2–8 ft) thick sandstone-rich beds of moderate frequency (25–30 Hz); (2) zone 2, composed of high-frequency (33–60 Hz) shale-rich zones that serve as stratigraphic-trapping-mechanisms; and (3) zone 3, composed of approximately 1.7–4 m (approximately 5–13 ft) thick sandstone-rich beds of low frequency (0–18 Hz) and relatively high porosity. These methods can be applied in other areas of the field with limited well control.

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