A rotating disk study of silver dissolution with thiourea in the presence of ferric sulfate

1990 ◽  
Vol 21 (3) ◽  
pp. 419-427 ◽  
Author(s):  
Batric Pesic ◽  
Thom Seal
Keyword(s):  
Rotating Disk ◽  
Ferric Sulfate ◽  
Silver Dissolution

To the Problem of Reducing the Amount of Harmful Emissions when Refining Silver

2018 ◽  
Vol 284 ◽  
pp. 877-881
Author(s):  
Sergey E. Polygalov ◽  
S.A. Mastugin ◽  
E.A. Shadrina
Keyword(s):  
Nitric Acid ◽  
Nitrogen Oxides ◽  
Dissolution Rate ◽  
Rotating Disk ◽  
Oxidation Potential ◽  
Solution Temperature ◽  
Harmful Emissions ◽  
Environmentally Friendly Process ◽  
Silver Dissolution ◽  
Kinetics Of

The work is devoted to the study of the possibilities of minimizing the release of nitrogen oxides during the dissolution of silver in nitric acid solutions during refining of the gold and silver alloy. Using a rotating disk, the maximum concentration of nitric acid is determined, at which the oxidation potential of the system is insufficient for the oxidation of silver. It has been established that at a temperature of 363 K and a concentration of HNO3 = 50 g/l, the dissolution rate of silver does not exceed 0.00022∙10-5 mol/(cm2∙s), and such conditions can be considered as background for an environmentally friendly process. To initiate dissolution, hydrogen peroxide was used as an alternative oxidizing agent. As a criterion for the rational use of the oxidant and the ecological purity of the process, the excess pressure over the solution was evaluated. The influence of the initial and current composition of the solution, temperature, and conditions of oxidant supply to the reactor on the kinetics of the target process was studied. It is shown that at a silver dissolution rate of 2.7∙10-6 mol/(cm2∙s), no release of nitrogen oxides was observed.

A Sectional Model for Investigating Microcontamination in a Rotating Disk CVD Reactor

2004 ◽  
Vol 38 (12) ◽  
pp. 1161-1170 ◽  
Author(s):  
Z. Sun ◽  
R. L. Axelbaum ◽  
R. W. Davis
Keyword(s):  
Rotating Disk ◽  
Sectional Model

Fabrication and Characterization of Nife Thin Film Composition Modulated Alloys

1996 ◽  
Vol 451 ◽  
Author(s):  
S. D. Leith ◽  
D. T. Schwartz
Keyword(s):  
Rotation Rate ◽  
Stripping Voltammetry ◽  
Rotating Disk ◽  
Oscillation Period ◽  
Rotating Disk Electrode ◽  
Disk Rotation ◽  
Rate Oscillation ◽  
Composition And Structure ◽  
Spatially Periodic

ABSTRACTDescribed are results showing that an oscillating flow-field can induce spatially periodic composition variations in electrodeposited NiFe films. Flow-induced NiFe composition modulated alloys (CMA's) were deposited on the disk of a rotating disk electrode by oscillating the disk rotation rate during galvanostatic plating. Deposit composition and structure were investigated using potentiostatic stripping voltammetry and scanning probe microscopy. Results illustrate a linear relationship between the composition modulation wavelength and the flow oscillation period. CMA's with wavelengths less than 10 nm can be fabricated when plating with a disk rotation rate oscillation period less than 3 seconds.

EXPERIMENTAL INVESTIGATION OF FLOW RESPONSE TO STATIONARY DISTURBANCE IN ROTATING-DISK FLOW

2019 ◽  
Vol XVI (2) ◽  
pp. 13-22
Author(s):  
Muhammad Ehtisham Siddiqui
Keyword(s):  
Boundary Layer ◽  
Boundary Layer Flow ◽  
Three Dimensional ◽  
Rotating Disk ◽  
Careful Analysis ◽  
Laboratory Frame ◽  
Transition To Turbulence ◽  
Turbulent Regime ◽  
Mean Velocity ◽  
Layer Flow

Three-dimensional boundary-layer flow is well known for its abrupt and sharp transition from laminar to turbulent regime. The presented study is a first attempt to achieve the target of delaying the natural transition to turbulence. The behaviour of two different shaped and sized stationary disturbances (in the laboratory frame) on the rotating-disk boundary layer flow is investigated. These disturbances are placed at dimensionless radial location (Rf = 340) which lies within the convectively unstable zone over a rotating-disk. Mean velocity profiles were measured using constant-temperature hot-wire anemometry. By careful analysis of experimental data, the instability of these disturbance wakes and its estimated orientation within the boundary-layer were investigated.

Sign in / Sign up

Export Citation Format

Share Document