A NEW METHOD FOR THE REDUCTION OF ALPHA-RAY BACKGROUND IN A GRIDDED IONIZATION CHAMBER

1962 ◽  
Vol 40 (5) ◽  
pp. 607-621 ◽  
Author(s):  
Tadayoshi Doke
Keyword(s):  
Ionization Chamber ◽  
Present Method ◽  
Parallel Plate ◽  
Alpha Particles ◽  
Operating Conditions ◽  
Good Resolution ◽  
Practical Applications ◽  
Weak Activity ◽  
Background Counting ◽  
Plate Type

By making use of grid pulses in a double-gridded ionization chamber, it was attempted to eliminate the background pulses caused by the alpha particles emitted from electrodes other than the cathode. Operating conditions for the reductions of the background in this method were investigated analytically. Using the double-gridded chamber of a parallel-plate type with a maximum sample area of 80 cm2 for alpha particles of 9 Mev, a background counting rate of one count per hour was achieved in the energy region from 3.5 to 9 Mev. It was found that an insulator like polyethylene could be used as a sample base with a good resolution for very weak activity. Spectra of weak alpha activities were measured by the present method. For the purpose of practical applications, the construction of a cylindrical double-gridded chamber is proposed.

A determination of W and G(H2) values for methyl fluoride and fluoroform

1970 ◽  
Vol 48 (12) ◽  
pp. 1812-1814 ◽  
Author(s):  
Mario Saca ◽  
R. A. Lee
Keyword(s):  
Gamma Rays ◽  
Ionization Chamber ◽  
Parallel Plate ◽  
Ion Pair ◽  
Methyl Fluoride ◽  
Gray Theory ◽  
Plate Type

Methyl fluoride and fluoroform have been irradiated with gamma rays from a 1200-Ci 60Co source. Ionization currents were measured using a Pyrex parallel-plate-type ionization chamber. W values of 27.2 and 28.0 eV were determined for the two gases, CH3F and CHF3, respectively. The method employed was a comparative one, making use of the Bragg–Gray theory of cavity ionization. G(H2) yields of 4.20 and 1.25 for CH3F and CHF3, respectively, were then calculated from the above W values and the measured ion-pair yields for hydrogen. The formation of hydrogen is probably due to the fact that the C—H bonds in these compounds are weaker than the C—F bonds.

Study On Automatic Adaptation for Control-Oriented Model of Advanced Diesel Engine

2021 ◽  
Author(s):  
Shunki Nishii ◽  
Yudai Yamasaki
Keyword(s):  
Operating Conditions ◽  
Physical Models ◽  
Model Parameters ◽  
Training Methods ◽  
Model Based Control ◽  
Practical Applications ◽  
Model Based ◽  
Automatic Adaptation ◽  
Automobile Engines ◽  
Adaptation Method

Abstract To achieve high thermal efficiency and low emission in automobile engines, advanced combustion technologies using compression autoignition of premixtures have been studied, and model-based control has attracted attention for their practical applications. Although simplified physical models have been developed for model-based control, appropriate values for their model parameters vary depending on the operating conditions, the engine driving environment, and the engine aging. Herein, we studied an onboard adaptation method of model parameters in a heat release rate (HRR) model. This method adapts the model parameters using neural networks (NNs) considering the operating conditions and can respond to the driving environment and the engine aging by training the NNs onboard. Detailed studies were conducted regarding the training methods. Furthermore, the effectiveness of this adaptation method was confirmed by evaluating the prediction accuracy of the HRR model and model-based control experiments.

scholarly journals The use of fricke dosimetry for low energy x-rays

2006 ◽  
Vol 49 (spe) ◽  
pp. 17-23 ◽  
Author(s):  
Carlos de Austerlitz ◽  
Viviane Souza ◽  
Heldio Pereira Villar ◽  
Aloisio Cordilha
Keyword(s):  
Ionization Chamber ◽  
Parallel Plate ◽  
Low Energy ◽  
Calibration Factor ◽  
X Rays ◽  
Measuring Systems ◽  
X Ray ◽  
Dose Measurements

The performance of four X-ray qualities generated in a Pantak X-ray machine operating at 30-100 kV was determined with a parallel-plate ionization chamber and a Fricke dosimeter. X-ray qualities used were those recommended by Deutsch Internationale Normung DIN 6809 and dose measurements were carried out with Plexiglas® simulators. Results have shown that the Fricke dosimeter can be used not only for soft X-ray dosimetry, but also for the maintenance of low-energy measuring systems' calibration factor.

The Fluid Power Control Performance Comparison Study of Two-Type ER Valve Based on FLUENT

2012 ◽  
Vol 472-475 ◽  
pp. 1989-1994
Author(s):  
Shi Sha Zhu ◽  
Liu Tao
Keyword(s):  
Pressure Drop ◽  
Power Control ◽  
Parallel Plate ◽  
Control Volume ◽  
Flow Simulation ◽  
Control Valve ◽  
Performance Comparison ◽  
Fluid Power ◽  
Control Performance ◽  
Plate Type

The current flow and pressure drop of ER valve which is a new type power control valve could be adjusted by the electric field signal directly .In this paper, the fluid power control performance of concentric cylindrical ER valve and parallel plate-type ER valve based on ER principal is comparative studied .First power control equation has been analysed, and then flow simulation of internal flow field of ER valve has been taken based on FLUENT software. The results show that with the increasing of the strength of excitation field, the flow through the two different type of ER valve decreases, the pressure drop between import and export is even greater; and the fluid power control performance of parallel plate-type ER valve is superior to concentric cylindrical ER valve under the same control volume.

scholarly journals SOC Estimation of Lead Carbon Batteries Based on the Operating Conditions of an Energy Storage System in a Microgrid System

Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 33
Author(s):  
Yuanyuan Chen ◽  
Zilong Yang ◽  
Yibo Wang
Keyword(s):  
Wavelet Transform ◽  
Energy Storage ◽  
Storage System ◽  
Estimation Method ◽  
Energy Storage System ◽  
Operating Conditions ◽  
Estimation Methods ◽  
Extend Kalman Filter ◽  
Practical Applications ◽  
Soc Estimation

The environment for practical applications of an energy storage system (ESS) in a microgrid system is very harsh, and therefore actual operating conditions become complex and changeable. In addition, the signal of the ESS sampling process contains a great deal of system and measurement noise, the sampled current fluctuates significantly, and also has high frequency. In this case, under such conditions, it is difficult to accurately estimate the state of charge (SOC) of the batteries in the ESS by common estimation methods. Therefore, this study proposes a compound SOC estimation method based on wavelet transform. This algorithm is very suitable for microgrid systems with large current, frequent fluctuating conditions, and high noise interference. The experimental results and engineering data show that the relative error of the method is 0.5%, which is much lower than the extend Kalman filter (EKF) based on wavelet transform.

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