Small particle erosion of coated and uncoated electro-optical materials

2019 ◽  
Author(s):  
Rachel Waxman ◽  
Howard Poisl ◽  
Ibrahim Guven
Keyword(s):  
Small Particle ◽  
Optical Materials ◽  
Particle Erosion

Experimental and Numerical Investigation of Small Particle Erosion in Gas Dominated Multiphase Flow

2021 ◽  
Author(s):  
G. Haider ◽  
M. Othayq ◽  
S. A. Shirazi
Keyword(s):  
Multiphase Flow ◽  
Small Particle ◽  
Hot Spots ◽  
Flow Behavior ◽  
Petroleum Engineering ◽  
Small Particles ◽  
Particle Erosion ◽  
Sand Particles ◽  
Pass Through ◽  
Paint Removal

Abstract Sand production is a significant challenge in petroleum engineering, and specifically in multiphase gas condensate wells where small amount of liquid is present with the gas. Sand particles entrained in multiphase flow can severely affect the integrity of fluid transportation structures such as pipelines, elbows, and reducers. Traditionally, sand management techniques such as sand screens and gravel packs are used to control sand. However, small particles can pass through these controls. Furthermore, small particles can block a part of the sand screen, causing high velocities in other sections which can cause erosion of the sand screen openings allowing larger particles to pass through which in turn cause more erosion. Furthermore, these small particles are highly susceptible to turbulent regions of flow and can cause severe erosion in these regions. Hence, it is critically important to understand the erosion caused by small particles. This study investigates the effect of small particles on erosion. Small particle erosion is more severe in gas dominated multiphase flows such as annular and mist flows than liquid dominated bubbly and slug flows. A 90-degree standard elbow is used in the experimental and numerical analyses because of its high erosion vulnerability and its importance in pipeline applications. This is because the flow changes direction in this geometry which has complex implications on erosion. This study follows the below mentioned research method: 1) Flow Visualization Study: To understand the flow behavior in bend. 2) Paint-Removal Study: To visualize the progress of paint-removal pattern and to identify the erosion hot spots caused by sand particles. 3) Multiphase Erosion Experiments: To determine the wall thickness loss on identified hot spots using fix-mounted temperature compensated ultrasonic measurement technique. 4) Computational Fluid Dynamics (CFD) Study: To compare erosion patterns with CFD simulations of multiphase flow. Furthermore, the effects of particle size on erosion ratio and its distribution in pipe bends are discussed. The CFD results of larger particles agree better with experimental data than for smaller particles using existing erosion models.

SREM observation of the interaction between the in-situ deposited Pd small particles and MgO cleavage surface

1986 ◽  
Vol 44 ◽  
pp. 382-383
Author(s):  
H.-J. Ou
Keyword(s):  
Electron Microscopy ◽  
Small Particle ◽  
Small Particles ◽  
Cleavage Surface ◽  
Metallic Particles ◽  
Microscopy Technique ◽  
Ceramic Surfaces ◽  
Reflection Electron Microscopy ◽  
New Perspective

The understanding of the interactions between the small metallic particles and ceramic surfaces has been studied by many catalyst scientists. We had developed Scanning Reflection Electron Microscopy technique to study surface structure of MgO hulk cleaved surface and the interaction with the small particle of metals. Resolutions of 10Å has shown the periodic array of surface atomic steps on MgO. The SREM observation of the interaction between the metallic particles and the surface may provide a new perspective on such processes.

Structural/Property Relationships for Optical Materials

1993 ◽  
Vol 329 ◽  
Author(s):  
Vivien D.
Keyword(s):  
Crystal Structure ◽  
Optical Properties ◽  
Electronic Structure ◽  
Chemical Composition ◽  
Field Strength ◽  
Optical Materials ◽  
Site Occupancy ◽  
Laser Materials ◽  
Crystal Field Strength ◽  
The Matrix

AbstractIn this paper the relationships between the crystal structure, chemical composition and electronic structure of laser materials, and their optical properties are discussed. A brief description is given of the different laser activators and of the influence of the matrix on laser characteristics in terms of crystal field strength, symmetry, covalency and phonon frequencies. The last part of the paper lays emphasis on the means to optimize the matrix-activator properties such as control of the oxidation state and site occupancy of the activator and influence of its concentration.

Resonance Scattering by a Small Particle above a Perfectly Reflecting Periodic Rough Surface

2005 ◽  
Vol 64 (10) ◽  
pp. 819-831
Author(s):  
F.G. Bass ◽  
D. V. Mikhaylova ◽  
V. Prosentsov ◽  
L. Resnick
Keyword(s):  
Rough Surface ◽  
Small Particle ◽  
Resonance Scattering
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