scholarly journals Modelling the light-ion densities in the ionosphere

1996 ◽  
Vol 39 (6) ◽  
Author(s):  
S. M. Stankov
Keyword(s):  
Steady State ◽  
Theoretical Model ◽  
Satellite Measurements ◽  
Middle Latitudes ◽  
Analytical Functions ◽  
Density Ratios ◽  
Upper Ionosphere ◽  
Existing Data

A steady-state theoretical model is used to obtain variations of the H+/O+ and He+/O+ density ratios in the upper ionosphere at middle latitudes. The model results are compared with the existing data from satellite measurements. Analytical functions are constructed approximating the latitude and altitude variations of these ratios.

scholarly journals A steady-state F-region model and its use for satellite data analysis

1996 ◽  
Vol 39 (5) ◽  
Author(s):  
S. M. Stankov
Keyword(s):  
Steady State ◽  
Boundary Values ◽  
Satellite Measurements ◽  
F Region ◽  
Dipole Magnetic Field ◽  
Consistent Manner ◽  
Region Model ◽  
Field Lines ◽  
Searching Method ◽  
Upper Ionosphere

A steady-state mathematical model of the Earth's upper ionosphere and plasmasphere is presented. In the model the equations of continuity, momentum, and energy balance for O+, H+, and He+ ions are solved numerically along dipole magnetic field lines. As an extension of the model, a searching method is developed for de- termination of the boundary values in a self-consistent manner. Model results are compared with Atmosphere Explorer satellite measurements.

Analytical approach for transient photoconductivity in undoped a-Si:H

1995 ◽  
Vol 377 ◽  
Author(s):  
M. Goerlitzer ◽  
P. Pipoz ◽  
H. Beck ◽  
N. Wyrsch ◽  
A. V. Shah
Keyword(s):  
Steady State ◽  
Theoretical Model ◽  
Analytical Approach ◽  
Room Temperature ◽  
Free Electrons ◽  
Recombination Time ◽  
Sample Quality ◽  
Transient Photoconductivity ◽  
Light Intensities ◽  
Good Agreement

ABSTRACTTransient photoconductive response of undoped a-Si:H has been studied; the changes were analysed between two slightly different steady-state illumination conditions, at room temperature. A theoretical model is developed to describe transient photoconductivity; it yields good agreement with the measured curves for a whole range of light intensities. Numerical evaluations allows one to extract the recombination time of electrons. Comparison with steady-state photoconductivity yields a band mobility of free electrons between 0.1 and 6 cm2V−1s−1, depending upon sample quality.

Computational analysis of the steady state performance of an adjustable/controllable multi-pad bearing profile under LBP orientations

2020 ◽  
pp. 095440622095770
Author(s):  
Girish Hariharan ◽  
Raghuvir Pai
Keyword(s):  
Steady State ◽  
Theoretical Model ◽  
Theoretical Analysis ◽  
Film Thickness ◽  
Computational Analysis ◽  
Fluid Film ◽  
Adjustable Mechanism ◽  
State Behaviour ◽  
Steady State Behaviour ◽  
Steady State Performance

A theoretical model of a four-pad bearing profile with unique adjustable or controllable features is simulated in the present study by considering load directed between the pads. Radial and tilt adjustable mechanism of the four bearing pads can effectively control and modify the rotor operating behaviour. Inward and outward motions of the bearing pads result in the generation of narrow and broader convergent regions, which directly influences the fluid film pressures. In the theoretical analysis, load-between-pad (LBP) orientations and pad adjustment configurations are taken account of by employing a modified film thickness equation. The effect of load position in influencing the steady state behaviour of the four-pad adjustable bearing under varied pad displaced conditions is analysed in this study. The outcome of the analysis highlighted the effectiveness of four-pad adjustable bearing in improving the steady state performance by operating under negative adjustment conditions and with load acting on the bearing pads.

Steady-state theoretical model for terahertz wave detector using a parametric process

2010 ◽  
Vol 12 (4) ◽  
pp. 045202 ◽  
Author(s):  
C Jiang ◽  
J Liu ◽  
B Sun ◽  
K Wang ◽  
J Yao
Keyword(s):  
Steady State ◽  
Theoretical Model ◽  
Terahertz Wave ◽  
Wave Detector

Steady-State Theoretical Model of an Electro-Hydraulic Single-Disk Pilot Valve

1992 ◽  
Vol 114 (2) ◽  
pp. 293-298 ◽  
Author(s):  
Y. Sun ◽  
G. A. Parker
Keyword(s):  
Steady State ◽  
Theoretical Model ◽  
Experimental Verification ◽  
Control Device ◽  
Null Condition ◽  
Electromagnetic Model ◽  
Disk Valve ◽  
Single Disk ◽  
Electromagnetic Characteristics ◽  
Pilot Valve

The paper describes an electro-hydraulic single floating-disk valve suitable for use as a pilot control device. For this type of application proportional action involving small movements of the disk for the null condition is required. The theory for the steady-state linearized analysis of both the fluid and electromagnetic characteristics is developed. Experimental verification of the electromagnetic model is also described.

Performance of Lightly Loaded Gas Journal Bearings in the Slip-Flow and Turbulent-Flow Regimes

1968 ◽  
Vol 10 (4) ◽  
pp. 363-366
Author(s):  
M. D. Wood
Keyword(s):  
Steady State ◽  
Laminar Flow ◽  
Turbulent Flow ◽  
Reynolds Equation ◽  
Dynamic Performance ◽  
Slip Flow ◽  
Flow Regimes ◽  
Journal Bearings ◽  
Performance Parameters ◽  
Existing Data

The note compares recently published versions of the governing gas film equations for slip-flow and turbulent flow with Reynolds equation for laminar flow. The comparison shows how approximate values of steady-state and dynamic performance parameters may be deduced for the new conditions from existing data.

CONNECTIVITY AND ECONOMIC GROWTH

2016 ◽  
Vol 20 (8) ◽  
pp. 2148-2172
Author(s):  
Adriaan van Zon ◽  
Evans Mupela
Keyword(s):  
Economic Growth ◽  
Steady State ◽  
Theoretical Model ◽  
Scale Effect ◽  
Production Costs ◽  
Communication Costs ◽  
Central Planner ◽  
Simple Theoretical Model ◽  
State Growth ◽  
Connected Communities

We present a simple theoretical model that illustrates the benefits of regional connectivity and specialization for growth. Starting with one community, we show how welfare measured by utility per head increases as the number of connected communities increases. We assume a common connectivity infrastructure through which a central planner is able to add new communities to the pool of already connected communities, a costly but rewarding activity that is funded by levying a tax on those already connected. We find that increasing production costs lead to faster transitions toward the steady state, whereas increasing transportation and communication costs tend to lengthen the transition. The results point to reductions in transportation and communication costs, in particular, as a suitable vehicle for speeding up growth and underline the existence of a positive scale effect that induces integration and reinforces both transitional and steady state growth.

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