Dose response characteristics of new models of GAFCHROMIC films: Dependence on densitometer light source and radiation energy

2004 ◽  
Vol 31 (9) ◽  
pp. 2501-2508 ◽  
Author(s):  
Sou-Tung Chiu-Tsao ◽  
Tamara Duckworth ◽  
Chuanfang Zhang ◽  
Neil S. Patel ◽  
Chih-Yun Hsiung ◽  
...  
Keyword(s):  
Light Source ◽  
Dose Response ◽  
Radiation Energy ◽  
Response Characteristics ◽  
New Models ◽  
Gafchromic Films

Dose-response characteristics of an amorphous silicon EPID

2005 ◽  
Vol 32 (10) ◽  
pp. 3095-3105 ◽  
Author(s):  
Peter Winkler ◽  
Alfred Hefner ◽  
Dietmar Georg
Keyword(s):  
Amorphous Silicon ◽  
Dose Response ◽  
Response Characteristics

Varying dose–response characteristics of different immunoassays and an in-vitro bioassay for FSH are responsible for changing ratios of biologically active to immunologically active FSH

1990 ◽  
Vol 127 (3) ◽  
pp. 523-532 ◽  
Author(s):  
F. Jockenhövel ◽  
S. A. Khan ◽  
E. Nieschlag
Keyword(s):  
Sertoli Cell ◽  
Dose Response ◽  
Serum Levels ◽  
Biologically Active ◽  
Testicular Function ◽  
In Vitro Bioassay ◽  
Great Caution ◽  
Response Characteristics ◽  
Infertile Men

ABSTRACT Serum FSH levels in fertile and infertile men were determined by applying the Sertoli cell in-vitro bioassay and six different immunoassays. Bioassay and immunoassay estimates were significantly correlated (r ranging from 0·78 to 0·86; P<0·01). On average, all immunoassays measured lower FSH concentrations in samples with low FSH levels and higher FSH concentrations in those with high FSH levels compared with the bioassay. Ratios of bioactivity to immunoreactivity (B/I) were highest in fertile men and lowest in men with severe disturbances of testicular function. Depending on which immunoassay was used these differences were either significant or only marginal. Dose–response characteristics for WHO FSH standard preparation 78/549, used in the bioassay as well as in the immunoassays, were different between immunoassays and the bioassay, suggesting that decreasing B/I ratios with increasing FSH serum levels were method-related and reflected different slopes of the dose–response characteristics of the assays, rather than being true changes in the molecular composition of FSH. The present investigation underlines the necessity of choosing the immunoassay used for comparison with the bioassay carefully and of validating the system in regard to parallelism between dose–response characteristics. B/I ratios must be interpreted with great caution and previous studies which report changing B/I ratios in various endocrine situations may have to be reevaluated. Journal of Endocrinology (1990) 127, 523–532

scholarly journals Methods to Test the “Dimming Effect” Produced by a Decrease in the Number of Photons Received from Receding Light Sources

2020 ◽  
Author(s):  
Mark Zilberman
Keyword(s):  
Light Source ◽  
Opposite Direction ◽  
Ecliptic Plane ◽  
Light Sources ◽  
The Sun ◽  
Decimal Point ◽  
Relativistic Systems ◽  
The Earth ◽  
New Models ◽  
Direction Opposite

The hypothetical “Dimming Effect” describes the change of the number of photons arriving from a moving light source per unit of time. In non-relativistic systems, the “Dimming effect” may occur due to the growing distance of light sources moving away from the receiver. This means that due to the growing distance, the photons continuously require more time to reach the receiver, which reduces the number of received photons per time unit compared to the number of emitted photons. Understandably, the proposed “Dimming effect” must be tested (confirmed or rejected) through observations. a. This article provides the formula for the calculation of “Dimming effect” values using the redshift parameter Z widely used in astronomy. b. The “Dimming effect” can possibly be detected utilizing the orbital movement of the Earth around the Sun. In accordance to the “Dimming effect”, observers on Earth will view 1.0001 more photons per time unit emitted by stars located near the ecliptic plane in the direction of the Earth orbiting the Sun. And, in contrast, observers will view only 0.9999 photons per time unit emitted by stars located near the ecliptic plane in the direction opposite to the Earth orbiting the Sun. Calculating precise measurements of the same stars within a 6-month period can possibly detect this difference. These changes in brightness are not only for specific stars, as the change in brightness takes place for all stars near the ecliptic in the direction of the Earth’s orbit around the Sun and in the opposite direction. c. The “Dimming effect” can possibly be detected in a physics laboratory using a moving light source (or mirror) and photon counters located in the direction of travel and in the opposite direction. d. In theory, Dilation of time can also be used for testing the existence of the “Dimming effect.” However, in experiments on Earth this effect appears in only the 14th digit after the decimal point and testing does not appear to be feasible. e. Why is it important to test the “Dimming effect?” If confirmed, it would allow astronomers to adjust values of "Standard Candles" used in astronomy. Since “Standard Candles” are critical in various cosmological models, the “Dimming effect” can correct models and/or reveal and support new models. If it is proved that the “Dimming effect” does not exist, it will mean that the number of photons arriving per unit of time does not depend on the speed of the light source and observer, which is not so apparent.

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