Passage of electric current through illuminated semiconductor when electric-conductivity-anisotropy and relaxation-time parameters are inhomogeneous. I

1972 ◽  
Vol 15 (9) ◽  
pp. 1306-1309
Author(s):  
V. A. Mis'nik
Keyword(s):  
Relaxation Time ◽  
Electric Conductivity ◽  
Electric Current ◽  
Conductivity Anisotropy ◽  
Time Parameters

Influence of carbon nano-tubes adding on electric conductivity and heating of elastomers under electric current flowing

2020 ◽  
pp. 67-78
Author(s):  
A. V. Shchegolkov ◽  
◽  
V. S. Yagubov ◽  
Yu. A. Khan ◽  
F. F. Komarov ◽  
...  
Keyword(s):  
Electric Conductivity ◽  
Electric Current ◽  
Carbon Nano Tubes

scholarly journals PULSE METHOD FOR DETERMINATION OF TIME PARAMETERS THERMAL FIRE DETECTOR

2021 ◽  
Vol 4 (164) ◽  
pp. 166-170
Author(s):  
Ya. Kozak
Keyword(s):  
Electric Current ◽  
Time Constant ◽  
Sensitive Element ◽  
Integral Transformation ◽  
Pulse Method ◽  
Auxiliary Parameter ◽  
Sensing Element ◽  
Fire Detector ◽  
Time Parameters ◽  
Analytical Expressions

For thermal fire detectors with a thermoresistive sensitive element, the method of determining its time parameters is justified. The time parameters of operation and the time constant of the thermal fire detector are considered as time parameters. The method is based on the use of the Joule-Lenz effect, for the implementation of which single pulses of electric current are passed through the thermoresistive sensitive element of the fire detector. Pulses having the shape of a quarter sinusoid or a quarter cosinusoid are used as such test signals. Using the Laplace integral transformation, analytical expressions are obtained, which represent the formalization of the reaction of the thermoresistive sensitive element of the fire detector to the corresponding test signals. These analytical expressions are used to obtain the functional dependences of the fire detector time constants on the pulse duration of the electric current and the auxiliary parameter. The auxiliary parameter is the ratio of the values ​​of the output signal of the thermal fire detector at two fixed points in time. This choice of auxiliary parameter allows to ensure invariance with respect to the transfer coefficient of the thermal fire detector with a thermoresistive sensing element. The fixed moments of time are chosen to be equal to half and three quarters of the duration of the pulses of electric current flowing through the thermoresistive sensitive element of the fire detector. The time of operation of the thermal fire detector is determined in the form of two additive components, one of which is a time constant of the fire detector, and the other is determined by the values ​​of normalized parameters in accordance with existing regulations. A sequence of procedures is given, which together represent a method of determining the time parameters of thermal fire detectors of this type.

scholarly journals Electric Currents Connected With the Proton Flares of 7 July and 2 September, 1966

1971 ◽  
Vol 43 ◽  
pp. 417-421
Author(s):  
A. B. Severny
Keyword(s):  
Active Region ◽  
Field Strength ◽  
Magnetic Flux ◽  
Electric Field ◽  
Electric Field Strength ◽  
Electric Conductivity ◽  
Electric Current ◽  
Current Density ◽  
High Energy ◽  
Electric Currents

It is observed that the change of the net magnetic flux associated with flares can exceed 1017 Mx/s, which corresponds according to Maxwell's equation to the e.m.f. ∼ 109 V which is specific for the high energy protons generated in flares. It is shown that this value of e.m.f. can hardly be compensated by e.m.f. of inductance which should appear due to the actually measured motions in a flare generating active region. The values of electric field strength thus found, together with measured values of electric current density (from rotH), leads to an electric conductivity which is 103 times smaller than usually adopted.

Convection experiments with electrolytically heated fluid layers

1971 ◽  
Vol 48 (4) ◽  
pp. 703-719 ◽  
Author(s):  
E. W. Schwiderski ◽  
H. J. A. Schwab
Keyword(s):  
Time Dependence ◽  
Temperature Dependence ◽  
Electric Conductivity ◽  
Electric Current ◽  
Convection Flow ◽  
Convection Pattern ◽  
Fluid Layers ◽  
Direction Dependence ◽  
Heated Fluid ◽  
Theory And Experiments

Convection experiments described by Tritton & Zarraga (1967) with electrolytically heated fluid layers were renewed in order to investigate the reported phenomena, which were hitherto unknown and which contradicted a corresponding theory of Roberts. While the apparatus was essentially unchanged, provisions were incorporated to study the possible influence of several flow and equipment parameters on the convection pattern. With the exception of the temperature dependence of the electric conductivity, the new experiments displayed no essential effects of the convection parameters. Experiments with shallow fluid layers revealed a clear co-orientation of the convection flows with the electric current and a strong time dependence of the hexagonal patterns. Experiments with deeper fluid layers exhibited a considerably diminished time and direction dependence of the convection flow, and a significant reduction of the dilation of the cells. Based on these observations, it is concluded that no drastic differences between theory and experiments, and between internal and external heating, exist, provided the heating is sufficiently uniform.

Luminescence methods of estimating solvent dielectric-relaxation time parameters

1990 ◽  
Vol 52 (3) ◽  
pp. 255-260 ◽  
Author(s):  
S. M. Bystryak ◽  
G. I. Likhtenshtein ◽  
A. I. Kotel'nikov
Keyword(s):  
Relaxation Time ◽  
Dielectric Relaxation ◽  
Dielectric Relaxation Time ◽  
Time Parameters

scholarly journals Molecular Mobility and Stability Studies of Amorphous Imatinib Mesylate

Pharmaceutics ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 304 ◽  
Author(s):  
Bożena Karolewicz ◽  
Agata Górniak ◽  
Dominik M. Marciniak ◽  
Igor Mucha
Keyword(s):  
Relaxation Time ◽  
Imatinib Mesylate ◽  
Enthalpy Relaxation ◽  
Attenuated Total Reflectance ◽  
Molecular Relaxation ◽  
Scanning Calorimetry ◽  
Solid Dosage ◽  
Experimental Enthalpy ◽  
Time Parameters ◽  
The Mean

The proposed study examined the characterization and stability of solid-state amorphous imatinib mesylate (IM) after 15 months under controlled relative humidity (60 ± 5%) and temperature (25 ± 2 °C) conditions. After 2 weeks, and 1, 3, 6, and 15 months, the samples were characterized using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), X-ray powder diffractometry (XRPD), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) and scanning electron microscopy (SEM). Additionally, the amorphous form of imatinib mesylate was obtained via supercooling of the melt in a DSC apparatus, and aged at various temperatures (3, 15, 25 and 30 °C) and time periods (1–16 h). Glass transition and enthalpy relaxation were used to calculate molecular-relaxation-time parameters. The Kohlrausch–Williams–Watts (KWW) equation was applied to fit the experimental enthalpy-relaxation data. The mean molecular-relaxation-time constant (τ) increased with decreasing ageing temperature. The results showed a high stability of amorphous imatinib mesylate adequate to enable its use in solid dosage form.

scholarly journals A simplified numerical method to determine the shear stress relaxation time parameters by the example of polymers

2017 ◽  
pp. 146-157
Author(s):  
М.С. Воронин
Keyword(s):  
Shear Stress ◽  
Relaxation Time ◽  
Stress Relaxation ◽  
Numerical Method ◽  
Yield Stress ◽  
Viscoelastic Model ◽  
Wide Range ◽  
Stress Point ◽  
Time Parameters ◽  
Shear Stress Relaxation

Приводится метод расчета параметров функции времени релаксации касательных напряжений, являющейся одним из замыкающих соотношений для модели вязкоупругого тела максвелловского типа. Метод основан на упрощении системы уравнений, описывающей деформирование тонкого стержня в рамках модели, если рассматривать эту систему в точке начала пластической деформации. Метод позволяет отыскать те параметры времени релаксации, которые ответственны за описание предела упругости материала в широком диапазоне температур и скоростей деформации. Результаты применения метода демонстрируются сравнением с экспериментальными данными для трeх полимерных материалов: ПММА (полиметилметакрилат), ПТФЭ (политетрафторэтилен) и эпоксидной смолы. A numerical method to determine the parameters of the shear stress relaxation time is discussed. This function is one of the constitutive equations of a Maxwellian viscoelastic model. The method is based on a simplification of the system of equations describing the deformation of a thin rod when this system is considered at the yield stress point. The method allows one to find the relaxation time parameters responsible for the yield stress description in a wide range of temperatures and strain rates. The numerical results obtained by the method are compared with experimental data for polymethylmethacrylate, polytetrafluoroethylene, and epoxy resin.

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