Optimal evaluation of the total conversion coefficient of a reference flowmeter set

1980 ◽  
Vol 23 (11) ◽  
pp. 1019-1022
Author(s):  
K. P. Podkopaev ◽  
M. A. Danilov ◽  
V. G. Tseitlin
Keyword(s):  
Conversion Coefficient ◽  
Total Conversion ◽  
Reference Flowmeter ◽  
Total Conversion Coefficient ◽  
Optimal Evaluation

Total conversion coefficient of the 263 keV (21+/2→13+/2) transition in93mMo

1985 ◽  
Vol 85 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Ch. Suryanarayana ◽  
M. Venkateswara Rao ◽  
D. G. S. Narayana ◽  
S. Bhuloka Reddy ◽  
G. Satyanarayana ◽  
...  
Keyword(s):  
Conversion Coefficient ◽  
Total Conversion ◽  
Total Conversion Coefficient

THE TOTAL INTERNAL CONVERSION COEFFICIENT OF THE 279-kev TRANSITION FOLLOWING THE DECAY OF Hg203 AS MEASURED BY A NEW COINCIDENCE METHOD

1962 ◽  
Vol 40 (4) ◽  
pp. 383-392 ◽  
Author(s):  
J. G. V. Taylor
Keyword(s):  
Standard Deviation ◽  
Internal Conversion ◽  
Conversion Coefficient ◽  
Internal Conversion Coefficient ◽  
Coincidence Method ◽  
Β Decay ◽  
A Value ◽  
Conversion Coefficients ◽  
Γ Ray ◽  
Total Conversion Coefficient

Using a new coincidence method, the total internal conversion coefficient for the 279-kev transition following the β-decay of Hg203 has been measured with a standard deviation of about 1%. The method which employs a 4πβ–γ coincidence arrangement is based on the differential absorption of β-particles and conversion electrons in 4π geometry. For determining the absolute efficiencies of γ-ray spectrometers or ion-chambers, the method has the advantage of yielding directly the number of γ-ray quanta emitted per Hg203 disintegration without requiring any knowledge of the K:L:M conversion ratios. Likely sources of systematic error have been investigated and their effect has been shown to be smaller than the quoted standard deviation. The value obtained is α = 0.2262 ±.0019 or γ/β = 0.8155 ±.0015, in excellent agreement with the recent β-ray spectrometer measurements of Nijgh et al. This is of interest because a number of widely differing values of conversion coefficients for this transition have been reported. If the K/(L+M+N) conversion ratio of 2.60 ±.06 found by Nijgh et al. is combined with our total conversion coefficient, a value αK = 0.1633 ±.0017 is obtained.

STATEMENT OF THE PROBLEM ON SYNTHESIS OF OPTIMAL EVALUATION OF SIGNAL PARAMETERS IN NON-GAUSSIAN NOISE

2012 ◽  
Vol 71 (17) ◽  
pp. 1541-1555
Author(s):  
V. A. Baranov ◽  
S. V. Baranov ◽  
A. V. Nozdrachev ◽  
A. A. Rogov
Keyword(s):  
Gaussian Noise ◽  
Signal Parameters ◽  
Non Gaussian ◽  
Optimal Evaluation

SYNTHESIS OF BROADBAND DISTRIBUTED IMPEDANCE TRANSFORMERS WITH A GIVEN PHASE RESPONSE

2018 ◽  
pp. 40-47
Author(s):  
D. I. Volkhin ◽  
G. N. Devyatkov
Keyword(s):  
Transmission Lines ◽  
Conversion Coefficient ◽  
Power Conversion ◽  
Response Characteristic ◽  
Second Order ◽  
Phase Response ◽  
Synthesis Process ◽  
New Class ◽  
Broadband Matching ◽  
Active Impedance

The development of a new class of broadband matching devices, including active impedance transformers, with the possibility of correcting the phase response is an actual task at present. Synthesis of a broadband active impedance transformer with a phase response corresponding to a second-order lattice X-section in a distributed elemental basis based on the previously presented method for the synthesis of broadband matching devices with predetermined phase response is considered in this paper. As a result of synthesis, the y-matrix of the broadband transforming two-port network is obtained. The functions of its own parameters represented in the form of Foster. Applying various conditions of circuit realizability in the synthesis process, we obtained structures convenient for realization on microwave on regular transmission lines, one of which is investigated at various parameters of a given phase response. As a result of the research, it is found that the structure has a wide ability to reproduce the phase response of a second-order lattice X-section with different parameters, and also reproduce the linear phase response characteristic while maintaining an acceptable level of the power conversion coefficient in a given frequency band. Thus, the efficiency of the previously proposed method of synthesis of broadband matching devices with predetermined phase response is demonstrated, and also the possibilities of active impedance transformers on regular transmission lines are shown.

Selectivity changes of acetone transformation over ZSM-5 zeolites with different acido-basic properties

1989 ◽  
Vol 54 (8) ◽  
pp. 2054-2063 ◽  
Author(s):  
Jiří Čejka ◽  
Ludmila Kubelková ◽  
Pavel Jírů
Keyword(s):  
Main Product ◽  
High Conversion ◽  
Total Conversion ◽  
Basic Properties ◽  
Product Composition ◽  
Conversion Level ◽  
Integral Reactor ◽  
Low Activity ◽  
High Conversion Level

Acetone transformation catalyzed by HZSM-5 and NaZSM-5 zeolites and by zeolites modified with basic oxides was studied in an integral reactor at a temperature of 350 °C. Modification of acido-basic properties of ZSM-5 zeolites resulted both in the total conversion changes and in the essential changes in the product composition. Isobutene was found to be the main product over HZSM-5 zeolites exhibiting low activity, while aromatics prevailed when high conversion level was attained. Classical condensation of acetone yielding mesityloxide and phorones was observed over NaZSM-5 zeolites impregnated with CaO and ZnO.

scholarly journals Myopic retinal changes screening: comparison of sensitivity and specificity among 15 combinations of ultrawide field scanning laser ophthalmoscopy images

2021 ◽  
Author(s):  
Xuan Deng ◽  
Silvia Tanumiharjo ◽  
Qianyin Chen ◽  
Shengnan Li ◽  
Huimin Lin ◽  
...  
Keyword(s):  
Retrospective Study ◽  
Confidence Interval ◽  
Diagnostic Test ◽  
Scanning Laser ◽  
Test Accuracy ◽  
Scanning Laser Ophthalmoscopy ◽  
Reference Standard ◽  
High Performing ◽  
Primary Screening ◽  
Optimal Evaluation

Aims: To investigate the evaluation indices (diagnostic test accuracy and agreement) of 15 combinations of ultrawide field scanning laser ophthalmoscopy (UWF SLO) images in myopic retinal changes (MRC) screening to determine the combination of imaging that yields the highest evaluation indices in screening MRC. Methods: This is a retrospective study of UWF SLO images obtained from myopes and were analyzed by two retinal specialists independently. 5-field UWF SLO images that included the posterior (B), superior (S), inferior (I), nasal (N) and temporal (T) regions were obtained for analysis and its results used as a reference standard. The evaluation indices of different combinations comprising of one to four fields of the retina were compared to determine the abilities of each combinations screen for MRC. Results: UWF SLO images obtained from 823 myopic patients (1646 eyes) were included for the study. Sensitivities ranged from 50.0% to 98.9% (95% confidence interval (CI), 43.8-99.7%); the combinations of B+S+I (97.3%; 95% CI, 94.4-98.8%), B+T+S+I (98.5%; 95% CI, 95.9-99.5%), and B+S+N+I (98.9%; 95% CI, 96.4-99.7%) ranked highest. Furthermore, the combinations of B+S+I, B+T+S+I and B+S+N+I also revealed the highest accuracy (97.7%; 95% CI, 95.1-100.0%, 98.6%; 95% CI, 96.7-100.0%, 98.8%; 95% CI, 96.9-100.0%) and agreement (Kappa = 0.968, 0.980 and 0.980). For the various combinations, specificities were all higher than 99.5% (95% CI, 99.3-100.0%). Conclusion: In our study, screening combinations of B+S+I, B+T+S+I and B+S+N+I stand out with high-performing optimal evaluation indices. However, when time is limited, B+S+I may be more applicable in primary screening of MRC.

THE DECAY OF Pm149

1960 ◽  
Vol 38 (12) ◽  
pp. 1577-1585 ◽  
Author(s):  
Agda Artna ◽  
Margaret E. Law
Keyword(s):  
High Resolution ◽  
Gamma Rays ◽  
Gamma Ray ◽  
Conversion Coefficient ◽  
Beta Spectrum ◽  
Multichannel Analyzer ◽  
Coincidence Spectrometer ◽  
Beta Spectrometer ◽  
Beta Group

The 52.8-hour activity of Pm149 has been investigated using a high resolution beta spectrometer, a lens type coincidence spectrometer, and a scintillation spectrometer in conjunction with a multichannel analyzer. The beta spectrum was found to consist of two groups with maximum energies of 1.072 ± 0.002 Mev and 0.786 ± 0.004 Mev, and intensities of 97.1 ± 0.4% and 2.9 ± 0.4% respectively. A gamma ray of energy 285.7 ± 0.3 kev was found to be in coincidence with the 0.786-Mev beta group. No other gamma rays with intensities greater than 0.1% were found. The K conversion coefficient for the 286-kev transition was measured to be 0.075 ± 0.008. This together with the values of 6.5 ± 0.7 and 4 ± 1 obtained for the K/L and L/M conversion ratios respectively indicate that this transition is M1 in character with less than 10% E2 admixture.

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