The Behavior of Oxidation Stacking Faults During O2/NF3 Oxidation of Silicon

1986 ◽  
Vol 82 ◽  
Author(s):  
U. S. Kim ◽  
R. J. Jaccodine
Keyword(s):  
Steady State ◽  
Oxidation Process ◽  
Stacking Faults ◽  
Transient State ◽  
Linear Shrinkage ◽  
State Condition ◽  
Shrinkage Rate ◽  
Steady State Condition ◽  
Initial Transient ◽  
Vacancy Flux

ABSTRACTThe behavior of oxidation—induced stacking faults(OSFs) during the O2 /NF3 oxidation of silicon has been investigated in the temperature range of 850–1100°C with varying concentration of NF 3 (0.011—0.044 vol%). In this study, we report the rapid and non-linear shrinkage of pregrown OSFs with time by a new oxidation process including small(ppm) additions of fluorine compound to the oxidant. It is also found that the shrinkage rate of OSF decreases as the oxidation time is increased. It is proposed that the fast OSF shrinkage is due to excessive vacancy flux as a result of the reaction of fluorine at the Si/SiO2 interface during the initial transient state, and subsequently the shrinkage rate is reduced as the steady—state condition of vacancy—interstitial recombination is approached.

Continuous determination of the volume of a space in a non steady state condition

1974 ◽  
Vol 36 (1) ◽  
pp. 59-66
Author(s):  
Oscar A. Gómez-Poviña ◽  
Carmen Sainz de Calatroni ◽  
Susana Orden de Puhl ◽  
Mariano J. Guerrero
Keyword(s):  
Steady State ◽  
State Condition ◽  
Steady State Condition ◽  
Continuous Determination

An Approach for Snaky Well Productivity under Steady-State Condition

2006 ◽  
Author(s):  
Zhilin Qi ◽  
Zhimin Du ◽  
Baosheng Liang ◽  
Yong Tang ◽  
Shouping Wang ◽  
...  
Keyword(s):  
Steady State ◽  
State Condition ◽  
Well Productivity ◽  
Steady State Condition

Thermo-structural analysis of a honeycomb-type volumetric absorber for concentrated solar power applications

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Masoud Behzad ◽  
Benjamin Herrmann ◽  
Williams R. Calderón-Muñoz ◽  
José M. Cardemil ◽  
Rodrigo Barraza
Keyword(s):  
Heat Transfer ◽  
Thermal Stress ◽  
Steady State ◽  
Discrete Model ◽  
Continuum Model ◽  
Transient State ◽  
Operating Conditions ◽  
Steady State Condition ◽  
Content Type ◽  
The Continuum

Purpose Volumetric air receivers experience high thermal stress as a consequence of the intense radiation flux they are exposed to when used for heat and/or power generation. This study aims to propose a proper design that is required for the absorber and its holder to ensure efficient heat transfer between the fluid and solid phases and to avoid system failure due to thermal stress. Design/methodology/approach The design and modeling processes are applied to both the absorber and its holder. A multi-channel explicit geometry design and a discrete model is applied to the absorber to investigate the conjugate heat transfer and thermo-mechanical stress levels present in the steady-state condition. The discrete model is used to calibrate the initial state of the continuum model that is then used to investigate the transient operating states representing cloud-passing events. Findings The steady-state results constitute promising findings for operating the system at the desired airflow temperature of 700°C. In addition, we identified regions with high temperatures and high-stress values. Furthermore, the transient state model is capable of capturing the heat transfer and fluid dynamics phenomena, allowing the boundaries to be checked under normal operating conditions. Originality/value Thermal stress analysis of the absorber and the steady/transient-state thermal analysis of the absorber/holder were conducted. Steady-state heat transfer in the explicit model was used to calibrate the initial steady-state of the continuum model.

VIBRATIONS OF THE CLOSED FRAME STRUCTURES IN A STEADY-STATE CONDITION

Akustika ◽  
2021 ◽  
pp. 4-7
Author(s):  
Veronika Krutova ◽  
Besarion Meskhi
Keyword(s):  
Steady State ◽  
State Condition ◽  
Frame Structures ◽  
Steady State Condition ◽  
Load Bearing ◽  
Gantry Cranes

The load-bearing frames of the technological machinery of various functional purposes, such as bridge and gantry cranes, locomotives, motor locomotives, etc., are energetically closed rod systems [1-10].

Modelling And Simulation of Topical Drug Diffusion in The Dermal Layer of Human Body

2021 ◽  
Vol 86 (2) ◽  
pp. 39-49
Author(s):  
Sudi Mungkasi
Keyword(s):  
Steady State ◽  
Human Body ◽  
Diffusion Problem ◽  
State Condition ◽  
Unsteady State ◽  
Steady State Condition ◽  
Drug Diffusion ◽  
Dermal Layer ◽  
Drug Concentrations ◽  
Proposed Model

We consider the problem of drug diffusion in the dermal layer of human body. Two existing mathematical models of the drug diffusion problem are recalled. We obtain that the existing models lead to inconsistent equations for the steady state condition. We also obtain that solutions to the existing models are unrealistic for some cases of the unsteady state condition, because negative drug concentrations occur due to the inappropriate assumption of the model. Therefore, in this paper, we propose a modified mathematical model, so that the model is consistent, and the solution is nonnegative for both steady and unsteady state conditions of the drug diffusion problem in the dermal layer of human body. For the steady state condition, the exact solution to the proposed model is given. For unsteady state condition, we use a finite difference method for solving the models numerically, where the discretisation is centred in space and forward in time. Simulation results confirm that our proposed model and method preserve the non-negativity of the solution to the problem, so the solution is more realistic than that of the old model.

Sign in / Sign up

Export Citation Format

Share Document