Role of Vibration-Induced Streaming in Float-Zone Crystal Growth

2000 ◽  
Author(s):  
Amrutur V. Anilkumar ◽  
Richard N. Grugel
Keyword(s):  
Sodium Nitrate ◽  
Silicone Oil ◽  
Surface Flow ◽  
Thermocapillary Flow ◽  
Return Flow ◽  
Zone Length ◽  
Float Zone ◽  
Streaming Velocity ◽  
Solid Liquid Interface ◽  
Solid Liquid

Abstract The streaming induced in a short vertical liquid column by the vibration of one of the supporting end walls has been utilized in this novel study. Vibration essentially drives a surface flow in the zone away from the vibrating wall, with the return flow in the bulk towards the wall. Preliminary measurements of the surface streaming velocity show that it increases with the frequency and amplitude of vibration and the zone length, and decreases with the viscosity of the zone liquid. This controlled surface streaming has been employed to balance a opposing, steady thermocapillary flow in model half-zones of silicone oil and Sodium Nitrate. In addition, in a float-zone solidification experiment with Sodium Nitrate - Barium Nitrate eutectic as the study material, we have demonstrated that streaming-based balancing of thermocapillary flow promotes a planar solid/liquid interface and a uniform microstructure.

scholarly journals Pillar versus dimple patterned surfaces for wettability and adhesion with varying scales

2018 ◽  
Vol 15 (148) ◽  
pp. 20180681 ◽  
Author(s):  
Meng Li ◽  
Qingwen Dai ◽  
Wei Huang ◽  
Xiaolei Wang
Keyword(s):  
Adhesion Force ◽  
Silicone Oil ◽  
Scale Dependence ◽  
Liquid Interface ◽  
Patterned Surfaces ◽  
Adhesion Properties ◽  
Flat Surfaces ◽  
Micro Dimples ◽  
Solid Liquid Interface ◽  
Solid Liquid

Inspired by biological topographical surfaces, micropatterned elastomeric surfaces with square pillars and dimples of different geometry scales were fabricated. Their wettability and adhesion properties with various liquids were systematically investigated and compared with flat surfaces. Interesting results were obtained in the case of silicone oil (the toe-pad-like wetting case) in that the scale-dependent wettability and adhesion performed inversely for pillars and dimples. Micropillars significantly enhanced the surface wettability with a geometry scale dependence, whereas the dimples suppressed the wettability independent of the geometry scale. The adhesion force of the micropillars increased with an increase of the geometry scale. However, in the case of the micro-dimples, the adhesion force obviously decreased with an increase of the geometry scale. This behaviour was attributed to the fact that pillars are ‘open’ to oil but dimples are ‘close’ to oil, presenting different orientations to the solid–liquid interface.

COMPARISON OF STRESS RELIEF MECHANISMS OF METAL FILMS DEPOSITED ON LIQUID SUBSTRATES BY THERMAL EVAPORATING AND SPUTTERING

2010 ◽  
Vol 24 (08) ◽  
pp. 997-1005 ◽  
Author(s):  
SEN-JIANG YU ◽  
YONG-JU ZHANG ◽  
MIAO-GEN CHEN
Keyword(s):  
Metal Film ◽  
Silicone Oil ◽  
Stress Relief ◽  
Metal Films ◽  
Liquid Silicone ◽  
Surface Patterns ◽  
Sandwiched Structure ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Surface Morphologies

Various metal film systems, deposited on liquid (silicone oil) substrates by thermal evaporating and DC-magnetron sputtering methods, have been successfully fabricated and the stress relief mechanisms are systematically studied by analyzing the characteristic surface morphologies. The experiment shows that the evaporating metal films can move on silicone oil surfaces freely due to the nearly zero adhesion of solid–liquid interface, which results in spontaneous formation of ordered surface patterns with a characteristic sandwiched structure driven by the internal stress. For the sputtering metal film system, however, the top surface of silicone oil can be modified to form an elastomeric polymer layer on the liquid substrate during deposition. Subsequent cooling of the system creates a higher compressive stress in the film, which is relieved by buckling of the film to form periodic wavy structures because the adhesion of solid–elastomer interface is quite strong.

Simulation of Solid-Liquid Interaction in Presence of a Free Surface

2011 ◽  
Author(s):  
Iman Mirzaii ◽  
Mohammad Passandideh-Fard
Keyword(s):  
Free Surface ◽  
Rigid Motion ◽  
Free Fall ◽  
Free Surface Flow ◽  
High Viscosity ◽  
Surface Flow ◽  
Computational Domain ◽  
Solid Object ◽  
Solid Liquid Interface ◽  
Solid Liquid

In this study, a numerical algorithm is developed for simulating the interactions between a liquid and solid object in presence of a free-surface flow. The presented model is that of the fast-fictitious-domain method integrated into the volume-of-fluid (VOF) technique used for tracking the free surface motion. The developed model considers the solid object as a fluid with a high viscosity resulting in a rigid motion of the object and solves the governing equations everywhere in the computational domain including the solid object. In this methodology, the application of the no-slip condition on the solid-liquid interface and the evaluation of the acting forces on the solid object are performed implicitly. The developed model is validated by a comparison of the simulation results with those of the available experiments in the literature for the free fall of one and two circular disks in a liquid domain and a sphere during its entry into a more dense liquid through a free surface. For all cases considered, the results are in good agreement with those of the experiments and other numerical studies. The model is then used to simulate the complex liquid-solid interaction during the entry of a spinning disk into a liquid free surface.

Atom-probe analysis of the solid-liquid interface

1995 ◽  
Vol 53 ◽  
pp. 676-677
Author(s):  
J.A. Panitz
Keyword(s):  
Molecular Level ◽  
Selective Adsorption ◽  
Electronic Devices ◽  
Atom Probe ◽  
Chemical Agent ◽  
Hostile Environment ◽  
Solid Interface ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Chemically Selective

The first few atomic layers of a solid can form a barrier between its interior and an often hostile environment. Although adsorption at the vacuum-solid interface has been studied in great detail, little is known about adsorption at the liquid-solid interface. Adsorption at a liquid-solid interface is of intrinsic interest, and is of technological importance because it provides a way to coat a surface with monolayer or multilayer structures. A pinhole free monolayer (with a reasonable dielectric constant) could lead to the development of nanoscale capacitors with unique characteristics and lithographic resists that surpass the resolution of their conventional counterparts. Chemically selective adsorption is of particular interest because it can be used to passivate a surface from external modification or change the wear and the lubrication properties of a surface to reflect new and useful properties. Immunochemical adsorption could be used to fabricate novel molecular electronic devices or to construct small, “smart”, unobtrusive sensors with the potential to detect a wide variety of preselected species at the molecular level. These might include a particular carcinogen in the environment, a specific type of explosive, a chemical agent, a virus, or even a tumor in the human body.

The role of (bio)surfactant sorption in promoting the bioavailability of nutrients localized at the solid-water interface

1999 ◽  
Vol 39 (7) ◽  
pp. 91-98 ◽  
Author(s):  
Ryan N. Jordan ◽  
Eric P. Nichols ◽  
Alfred B. Cunningham
Keyword(s):  
Mass Transfer ◽  
Cell Membrane ◽  
Substrate Concentration ◽  
Water Interface ◽  
Industrial Systems ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Surfactant Sorption

Bioavailability is herein defined as the accessibility of a substrate by a microorganism. Further, bioavailability is governed by (1) the substrate concentration that the cell membrane “sees,” (i.e., the “directly bioavailable” pool) as well as (2) the rate of mass transfer from potentially bioavailable (e.g., nonaqueous) phases to the directly bioavailable (e.g., aqueous) phase. Mechanisms by which sorbed (bio)surfactants influence these two processes are discussed. We propose the hypothesis that the sorption of (bio)surfactants at the solid-liquid interface is partially responsible for the increased bioavailability of surface-bound nutrients, and offer this as a basis for suggesting the development of engineered in-situ bioremediation technologies that take advantage of low (bio)surfactant concentrations. In addition, other industrial systems where bioavailability phenomena should be considered are addressed.

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