Unstable Etching Of Si(110)with Potassium Hydroxide

2000 ◽  
Vol 657 ◽  
Author(s):  
Z. Moktadir ◽  
K. Sato ◽  
T. Shimizu ◽  
M. Shikida
Keyword(s):  
Experimental Data ◽  
Surface Tension ◽  
Linear Theory ◽  
Potassium Hydroxide ◽  
Early Stage ◽  
Morphological Evolution ◽  
Columnar Structure ◽  
Anisotropic Surface ◽  
Continuum Equation

ABSTRACTWe present the experimental data for the morphological evolution of Si(110) etched with Potassium Hydroxide. The observed results are interpreted using a continuum equation. The results reveal the presence of unstable etching, which leads to the formation of a columnar structure on the surface. The early stage of the formation of this columnar structure can be explained by a linear theory. This instability is caused by anisotropic surface tension.

Diagnostics of metal samples using the results of experimental and theoretical study of positively charged microparticles formed upon sample destruction

2018 ◽  
Vol 84 (10) ◽  
pp. 23-28
Author(s):  
D. A. Golentsov ◽  
A. G. Gulin ◽  
Vladimir A. Likhter ◽  
K. E. Ulybyshev
Keyword(s):  
Experimental Data ◽  
Early Stage ◽  
Experimental Studies ◽  
Material Model ◽  
Total Charge ◽  
Cross Sectional ◽  
Practical Applications ◽  
Mechanical And Electrical Properties ◽  
Order Of Magnitude ◽  
Using Data

Destruction of bodies is accompanied by formation of both large and microscopic fragments. Numerous experiments on the rupture of different samples show that those fragments carry a positive electric charge. his phenomenon is of interest from the viewpoint of its potential application to contactless diagnostics of the early stage of destruction of the elements in various technical devices. However, the lack of understanding the nature of this phenomenon restricts the possibility of its practical applications. Experimental studies were carried out using an apparatus that allowed direct measurements of the total charge of the microparticles formed upon sample rupture and determination of their size and quantity. The results of rupture tests of duralumin and electrical steel showed that the size of microparticles is several tens of microns, the particle charge per particle is on the order of 10–14 C, and their amount can be estimated as the ratio of the cross-sectional area of the sample at the point of discontinuity to the square of the microparticle size. A model of charge formation on the microparticles is developed proceeding from the experimental data and current concept of the electron gas in metals. The model makes it possible to determine the charge of the microparticle using data on the particle size and mechanical and electrical properties of the material. Model estimates of the total charge of particles show order-of-magnitude agreement with the experimental data.

Effects of Copper Extraction-Stripping Loops on Entrainment in Aqueous Raffinate

2014 ◽  
Vol 908 ◽  
pp. 18-21
Author(s):  
Yan Jun Liu ◽  
Xiao Rong Liu ◽  
Hui Li ◽  
Yong Sheng Li ◽  
Qing Li ◽  
...  
Keyword(s):  
Surface Tension ◽  
Solvent Extraction ◽  
Early Stage ◽  
Organic Chemical ◽  
Copper Extraction ◽  
Organic Chemicals ◽  
Stabilization Mechanism ◽  
Absolute Value ◽  
Copper Solvent Extraction ◽  
Average Size

Effects of extraction-stripping loops of organic phase on organic chemical entrainment in the aqueous raffinate in copper solvent extraction were studied in this paper. Results demonstrated that the total amount of organic chemicals lost in the aqueous raffinate decreased with the increase of times of extraction-stripping loops but reached largest at third loop. Entrainment was the dominate way of organic chemicals losing in the aqueous raffinate at early stage of the loops. The formation of entrainment and its stabilization mechanism was also studied. The average size of entrained droplet trended to increase with extraction-stripping loops increasing. Meanwhile, the absolute value of zeta potential trended to decrease. The surface tension of the aqueous raffinate increased after reaching the minimum value 41.3 mN/m at the 3rd loop. It showed that the formation of entrained droplets and its stability were mainly affected by the surface tension of aqueous raffinate.

scholarly journals Revisiting Kelvin equation and Peng–Robinson equation of state for accurate modeling of hydrocarbon phase behavior in nano capillaries

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ilyas Al-Kindi ◽  
Tayfun Babadagli
Keyword(s):  
Experimental Data ◽  
Surface Tension ◽  
Equation Of State ◽  
Phase Behavior ◽  
Pore Radius ◽  
Microfluidic Chips ◽  
Tight Sandstone ◽  
Kelvin Equation ◽  
Rock Samples ◽  
Robinson Equation

AbstractThe thermodynamics of fluids in confined (capillary) media is different from the bulk conditions due to the effects of the surface tension, wettability, and pore radius as described by the classical Kelvin equation. This study provides experimental data showing the deviation of propane vapour pressures in capillary media from the bulk conditions. Comparisons were also made with the vapour pressures calculated by the Peng–Robinson equation-of-state (PR-EOS). While the propane vapour pressures measured using synthetic capillary medium models (Hele–Shaw cells and microfluidic chips) were comparable with those measured at bulk conditions, the measured vapour pressures in the rock samples (sandstone, limestone, tight sandstone, and shale) were 15% (on average) less than those modelled by PR-EOS.

scholarly journals A Kinetic Model for the Modification of Al2O3 Inclusions during Calcium Treatment in High-Carbon Hard Wire Steel

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1305
Author(s):  
Zuobing Xi ◽  
Changrong Li ◽  
Linzhu Wang
Keyword(s):  
Kinetic Model ◽  
Early Stage ◽  
Morphological Evolution ◽  
Product Layer ◽  
Melting Time ◽  
Calcium Treatment ◽  
High Carbon ◽  
Inclusion Modification ◽  
Shrinking Core ◽  
Wire Steel

Laboratory-scale experiments for the modification of Al2O3 inclusions by calcium treatment in high-carbon hard wire steel were performed and the compositions and morphological evolution of inclusions were studied. The kinetics of the modification of Al2O3 inclusions by calcium treatment were studied in high-carbon hard wire steel based on the unreacted shrinking core model, considering the transfer of Ca and Al through the boundary layer and within the product layer, coupled with thermodynamic equilibrium at the interfaces. The diffusion of Al in the inclusion layer was the limiting link in the inclusion modification process. The Ca concentration in molten steel had the greatest influence on the inclusion modification time. The modification time for inclusions tended to be longer in the transformation of higher CaO-containing calcium aluminate. The modification of Al2O3 into CA6 was fastest, while the most time was needed to modify CA into C12A7. It took about six times time longer at the later stage of inclusion modification than at the early stage. The complete modification time for inclusions increased with the square of their radii. The changes of CaO contents with melting time were estimated based on a kinetic model and was consistent with experimental results.

Concentration Dependence of the Surface Tension of Three and Four-Component Systems with Peculiarities in the Surface Tension Isotherms of Lateral Binary Melts

2021 ◽  
Vol 1022 ◽  
pp. 194-202
Author(s):  
R.Kh. Dadashev ◽  
R.A. Kutuev
Keyword(s):  
Experimental Data ◽  
Surface Tension ◽  
Concentration Dependence ◽  
Experimental Error ◽  
Binary Systems ◽  
Experimental Studies ◽  
Study Results ◽  
Component Systems ◽  
Minimum Depth ◽  
Surface Tension Isotherms

The experimental study results of the melts concentration dependence of the surface tension of the four-component indium-tin-lead-bismuth system and its constituent binary systems of indium-tin, indium-lead, indium-bismuth, tin-lead, tin-bismuth, lead-bismuth are presented in the paper. It is shown that the concentration dependence of the melts surface tension of the In-Sn-Pb-Bi four-component system can be predicted from the data on ST (surface tension) values of lateral binary systems. Features in the ST isotherms in the form of a minimum are observed only in the indium-tin lateral system from all lateral binaries. A distinctive feature of the detected minimum is that the minimum depth slightly exceeds the experimental error. Therefore, in addition to the fact that the area of average compositions was studied more thoroughly, we carried out the surface tension measurements by two independent methods. The experimental data obtained by both methods coincide within the experimental error and indicate the extremum availability on ST isotherms. Thus, ST experimental studies by two independent methods confirmed the presence of a flat minimum on ST isotherms of the indium-tin binary system increasing the reliability of the obtained data. The obtained outcomes and their comparison with experimental data have shown that the considered models for predicting surface properties based on data due to similar properties of lateral binary systems adequately reflect the experimental dependences. However, the prediction model based on Kohler's method of excess values describes the experimental curves more accurately.

Numerical Simulation of Oil-Droplet Cleavage by Surfactant

1996 ◽  
Vol 118 (2) ◽  
pp. 201-209 ◽  
Author(s):  
Xiaoyi He ◽  
Micah Dembo
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Surface Tension ◽  
Large Deformation ◽  
Concentration Gradient ◽  
Surface Tension Gradient ◽  
Oil Droplets ◽  
Numerical Computations ◽  
Oil Droplet ◽  
Pure Surface

We present numerical computations of the deformation of an oil-droplet under the influence of a surface tension gradient generated by the surfactant released at the poles (the Greenspan experiment). We find this deformation to be very small under the pure surface tension gradient. To explain the large deformation of oil droplets observed in Greenspan’s experiments, we propose the existence of a phoretic force generated by the concentration gradient of the surfactant. We show that this hypothesis successfully explains the available experimental data and we propose some further tests.

Dynamics of Evaporation and Cooling of a Water Droplet During the Early Stage of Depressurization

2009 ◽  
Author(s):  
L. Liu ◽  
Q. C. Bi ◽  
G. X. Wang
Keyword(s):  
Experimental Data ◽  
Water Droplet ◽  
Effective Conductivity ◽  
Numerical Study ◽  
Early Stage ◽  
Droplet Surface ◽  
Large Temperature ◽  
Measured Temperature ◽  
Equilibrium Evaporation ◽  
Electro Magnetic

This paper reports an experimental and numerical study of evaporation and cooling of a water droplet during the early stage of depressurization in a test vessel. During the experiment, a distilled water droplet was suspended on a thermocouple, which was also used to measure the droplet center temperature, and the droplet surface temperature was captured by an infrared thermograph. Experimental data indicated a large temperature difference within the droplet during the early stage of depressurization. A thermodynamic analysis of the experimental data found that the pressure reduction was not fast enough to induce liquid superheating and thus equilibrium evaporation was expected. A mathematical model was then constructed to simulate the droplet evaporation process. The model solves one-dimensional heat conduction equation for the temperature distribution inside the water droplet, with the convective heat transfer inside the droplet simplified through an effective conductivity factor. A simplified treatment was introduced to quantify the convective evaporation due to air movement and droplet swing induced by sudden opening of the electro-magnetic valve and the following air exiting. The model-predictions agree well with the measured temperature data, demonstrating the soundness of the present model.

TEMPERATURE DEPENDENCE OF SURFACE TENSION OF LIQUID CRYSTALS AT THE PHASE TRANSITION

1995 ◽  
Vol 09 (03n04) ◽  
pp. 237-242 ◽  
Author(s):  
R. MOLDOVAN ◽  
M. TINTARU ◽  
T. BEICA ◽  
S. FRUNZA ◽  
D. N. STOENESCU
Keyword(s):  
Experimental Data ◽  
Phase Transition ◽  
Surface Tension ◽  
Free Energy ◽  
Surface Layer ◽  
Order Parameter ◽  
Unit Area ◽  
Negative Slope ◽  
First Order ◽  
First Order Transition

The surface tension is calculated as the excess of the free energy per unit area, due to the presence of a surface layer, using Landau–de Gennes expansions, in the hypothesis of a first order transition in the bulk and taking into account the dependence of the surface free energy from the surface tilt angle. The surface order parameter is calculated and surface-ordered phase above the phase transition temperature has been found. A variety of calculated surface tension versus temperature curves with a jump at the phase transition, with positive or negative slope, well describing the experimental data from literature, have been attained.

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