scholarly journals Flow Patterns: Numerical Simulations and In Situ Optical Microscopy Connecting Flow Pattern, Crystallization, and Thin‐Film Properties for Organic Transistors with Superior Device‐to‐Device Uniformity (Adv. Mater. 48/2020)

2020 ◽  
Vol 32 (48) ◽  
pp. 2070357
Author(s):  
Jeong‐Chan Lee ◽  
Minho Lee ◽  
Ho‐Jun Lee ◽  
Kwangguk Ahn ◽  
Jaewook Nam ◽  
...  
Keyword(s):  
Thin Film ◽  
Numerical Simulations ◽  
Optical Microscopy ◽  
Flow Pattern ◽  
Flow Patterns ◽  
Organic Transistors ◽  
Film Properties ◽  
Device To Device

scholarly journals Tunability of MoO3 Thin-Film Properties Due to Annealing in Situ Monitored by Hard X-ray Photoemission

ACS Omega ◽  
2019 ◽  
Vol 4 (6) ◽  
pp. 10985-10990 ◽  
Author(s):  
Xiaxia Liao ◽  
Ah Reum Jeong ◽  
Regan G. Wilks ◽  
Sven Wiesner ◽  
Marin Rusu ◽  
...  
Keyword(s):  
Thin Film ◽  
Film Properties ◽  
X Ray

Study on Countercurrent Flow in a PWR Hot Leg Under Reflux Cooling

2010 ◽  
Author(s):  
Noritoshi Minami ◽  
Michio Murase ◽  
Akio Tomiyama
Keyword(s):  
Numerical Simulations ◽  
Flow Pattern ◽  
Flow Rate ◽  
Current Flow ◽  
Air Flow ◽  
Flow Patterns ◽  
Interfacial Friction ◽  
Air Flow Rate ◽  
Counter Current Flow ◽  
Counter Current

In this paper, results of experiments and numerical simulations for counter-current flow in a pressurized water reactor hot leg under reflux cooling are summarized. In the experiments, we used two types of small scale PWR hot legs. One was a 1/5th scale rectangular duct, and the other was a 1/15th scale circular pipe. Air and water were used for gas and liquid phases. The air flow rate and the supplied water flow rate were varied to observe flow pattern and measure the counter-current flow limitation (CCFL) characteristics. Flow patterns in the elbow and the inclined section were strongly affected by those in the horizontal section. In the 1/15th scale circular pipe experiments, CCFL characteristics obtained by increasing the air flow rate differed from those obtained by decreasing it. CCFL characteristics corresponded to the flow pattern transition. In the numerical simulations, we used a three-dimensional two-fluid model to evaluate the capability of predicting counter-current flow in the hot leg. Good agreements between measured and predicted flow patterns and CCFL characteristics were obtained by using an appropriate set of correlations for interfacial friction coefficient. We also carried out simulations of actual hot leg conditions to examine the effects of fluid properties and size. Predicted flow patterns and CCFL characteristics were close to those of scale model calculations. We concluded the combination of calculation model and interfacial friction coefficients used in this study can predict the counter-current flow in a hot leg.

Numerical and Experimental Study of Multiphase Transient Core-Annular Flow Patterns in a Spouted Bed

2020 ◽  
Vol 142 (9) ◽  
Author(s):  
Ling Zhou ◽  
Chen Han ◽  
Ling Bai ◽  
Weidong Shi ◽  
Ramesh Agarwal
Keyword(s):  
Numerical Simulations ◽  
Flow Pattern ◽  
High Speed ◽  
Annular Flow ◽  
Fluid Phase ◽  
Flow Patterns ◽  
Spouted Bed ◽  
High Speed Imaging ◽  
Spouted Beds ◽  
Number Of Particles

Abstract Dense solid–gas bubbling systems with combined fluid-particle motion are among one of the most extensively used fluidization forms used in the chemical industry. Therefore, it is important to have a good understanding of the hydrodynamic behavior of bubbles. In this paper, both the experiment and numerical simulations are used to investigate the flow patterns in a spouted bed. For numerical simulations, the bidirectional coupling simulations using computational fluid dynamics (CFD) with discrete element method (DEM) are conducted. The results show that the simulations can accurately predict the bubbles morphology compared with the experimental results. When the number of particles is 30,000, only a single core-annular flow pattern appears. When the number of particles is increased to 36,500, the single bubble in the spouted bed transitions into two and a double core-annular flow pattern emerges. As the number of particles is increased to 43,000, a complex multicore-annular flow pattern appears. These flow patterns are also observed in the experiments using high-speed imaging camera. This paper analyzes and explains the causes of these flow phenomena from the dynamic characteristics of particle phase and fluid phase. These results have great significance in providing guidance for optimization of dense phase bubbling spouted beds.

Observing Interfacial Sliding Processes in Solid–Solid Contacts

MRS Bulletin ◽  
2008 ◽  
Vol 33 (12) ◽  
pp. 1159-1167 ◽  
Author(s):  
Kathryn J. Wahl ◽  
W. Gregory Sawyer
Keyword(s):  
Thin Film ◽  
Optical Microscopy ◽  
Friction And Wear ◽  
Solid Lubricants ◽  
Solid Lubrication ◽  
Low Friction ◽  
Interfacial Sliding ◽  
Moving Contact ◽  
Powerful Approach

AbstractDirectly seeing into a moving contact is a powerful approach to understanding how solid lubricants develop low-friction, long-lived interfaces. In this article, we present optical microscopy and spectroscopy approaches that can be integrated with friction monitoring instrumentation to provide real-time, in situ evaluation of solid lubrication phenomena. Importantly, these tools allow direct correlation of common tribological events (such as variations in friction and wear) with the responsible sliding-induced mechanical and chemical phenomena. We demonstrate the utility of in situ approaches with applications to a variety of thin-film solid lubricants.

Kinetics of Photodeposition of Superconducting Films

1992 ◽  
Vol 285 ◽  
Author(s):  
C. H. Chen ◽  
R. C. Phillips ◽  
P. W. Morrison
Keyword(s):  
Thin Film ◽  
Mass Spectrometry ◽  
Real Time ◽  
Superconducting Films ◽  
In Situ Monitoring ◽  
Superconducting Film ◽  
Film Properties ◽  
Laser Ablation Process ◽  
Kinetics Of

ABSTRACTKinetics of photodeposition of superconducting films was studied by using real time in-situ monitoring of gas phase species with mass spectrometry and thin-film properties by Fourier Transform Infrared (FTIR) spectrometry. A mass spectrometer was used to study wavelength and power dependent desorbed atoms and molecules during laser ablation process. FTIR was used to monitor the surface properties of thin film. Real time surface temperatures can be easily obtained by FTIR. By combinging mass spectrometry and FTIR, an optimum condition of making high-quality superconducting film can possibly be found.

The use of transmission and analytical electron microscopy in studying reactions and phase transformations in thin film

1993 ◽  
Vol 51 ◽  
pp. 842-843
Author(s):  
K. Barmak
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Phase Transformations ◽  
Analytical Electron Microscopy ◽  
Ex Situ ◽  
Multilayer Thin Films ◽  
Absolute Concentration ◽  
Analytical Electron ◽  
Deposition Step

Generally, processing of thin films involves several annealing steps in addition to the deposition step. During the annealing steps, diffusion, transformations and reactions take place. In this paper, examples of the use of TEM and AEM for ex situ and in situ studies of reactions and phase transformations in thin films will be presented.The ex situ studies were carried out on Nb/Al multilayer thin films annealed to different stages of reaction. Figure 1 shows a multilayer with dNb = 383 and dAl = 117 nm annealed at 750°C for 4 hours. As can be seen in the micrograph, there are four phases, Nb/Nb3-xAl/Nb2-xAl/NbAl3, present in the film at this stage of the reaction. The composition of each of the four regions marked 1-4 was obtained by EDX analysis. The absolute concentration in each region could not be determined due to the lack of thickness and geometry parameters that were required to make the necessary absorption and fluorescence corrections.

Growth kinetics of Al2Cu in an Al-1.5Cu thin film by in Situ TEM

1993 ◽  
Vol 51 ◽  
pp. 1172-1173
Author(s):  
M. Park ◽  
S.J. Krause ◽  
S.R. Wilson
Keyword(s):  
Thin Film ◽  
In Situ Tem ◽  
Collector Plate ◽  
Transmission Electron ◽  
Device Processing ◽  
Corrosion Susceptibility ◽  
Precipitation Phenomena ◽  
Semiconductor Chips ◽  
Kinetics Of

Cu alloying in Al interconnection lines on semiconductor chips improves their resistance to electromigration and hillock growth. Excess Cu in Al can result in the formation of Cu-rich Al2Cu (θ) precipitates. These precipitates can significantly increase corrosion susceptibility due to the galvanic action between the θ-phase and the adjacent Cu-depleted matrix. The size and distribution of the θ-phase are also closely related to the film susceptibility to electromigration voiding. Thus, an important issue is the precipitation phenomena which occur during thermal device processing steps. In bulk alloys, it was found that the θ precipitates can grow via the grain boundary “collector plate mechanism” at rates far greater than allowed by volume diffusion. In a thin film, however, one might expect that the growth rate of a θ precipitate might be altered by interfacial diffusion. In this work, we report on the growth (lengthening) kinetics of the θ-phase in Al-Cu thin films as examined by in-situ isothermal aging in transmission electron microscopy (TEM).

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