Electrogeneration of aluminium to remove silica in water

2012 ◽  
Vol 65 (3) ◽  
pp. 434-439 ◽  
Author(s):  
S. L. Gelover-Santiago ◽  
S. Pérez-Castrejón ◽  
A. Martín-Domínguez ◽  
I. E. Villegas-Mendoza

This paper presents the results of a study on electrogeneration of aluminium, as a coagulant to remove silica in make-up water for cooling towers. Three electrochemical systems were tested, two with aluminium electrodes (one with polarity change and another without it), and a third one with aluminium anodes and cathodes of stainless steel. From the obtained results it was concluded that under the studied conditions, the most advantageous system to produce aluminium and remove silica is the one with both electrodes of aluminium working with direct current. Due to chemical production of aluminium at the cathode, the concentration of aluminium in the water at the outlet of the electrochemical reactor is much higher than the one calculated according to Faraday's law. Under the tested conditions it was possible to remove up to 66% of silica from water containing around 50 mg L−1.

Author(s):  
M. R. Pinnel ◽  
A. Lawley

Numerous phenomenological descriptions of the mechanical behavior of composite materials have been developed. There is now an urgent need to study and interpret deformation behavior, load transfer, and strain distribution, in terms of micromechanisms at the atomic level. One approach is to characterize dislocation substructure resulting from specific test conditions by the various techniques of transmission electron microscopy. The present paper describes a technique for the preparation of electron transparent composites of aluminum-stainless steel, such that examination of the matrix-fiber (wire), or interfacial region is possible. Dislocation substructures are currently under examination following tensile, compressive, and creep loading. The technique complements and extends the one other study in this area by Hancock.The composite examined was hot-pressed (argon atmosphere) 99.99% aluminum reinforced with 15% volume fraction stainless steel wire (0.006″ dia.).Foils were prepared so that the stainless steel wires run longitudinally in the plane of the specimen i.e. the electron beam is perpendicular to the axes of the wires. The initial step involves cutting slices ∼0.040″ in thickness on a diamond slitting wheel.


2015 ◽  
Vol 18 (2) ◽  
pp. 341-346 ◽  
Author(s):  
Ramaiany Carneiro Mesquita ◽  
José Manoel Rivas Mecury ◽  
Auro Atsumi Tanaka ◽  
Regina Célia de Sousa

2013 ◽  
Vol 233 ◽  
pp. 49-56 ◽  
Author(s):  
Qiang Chen ◽  
Luis Cordero-Arias ◽  
Judith A. Roether ◽  
Sandra Cabanas-Polo ◽  
Sannakaisa Virtanen ◽  
...  

2019 ◽  
Vol 283 ◽  
pp. 07011
Author(s):  
Didier Flotté ◽  
David Macel ◽  
Abd Ennour Bouzenad ◽  
Frédéric Navacchia

Monitoring the operation of the latest-generation nuclear reactor requires ultrasonic transducers able to operate at very high temperatures (> 600°C). To achieve this, CEA has requested from “Institut de Soudure” to help developing a new technology for these transducers compared to the one previously developed. This began with the development of a reliable assembly technique between a lithium niobate piezoelectric disc whose Curie temperature exceeds 1100°C and stainless steel discs. The chosen solution was to braze the niobate disc between two stainless steel discs. Parallel to this development, it was also necessary to develop a NDE procedure to verify the quality of the brazing assemblies. This development began with a simulation of immersion ultrasonic testing of the assemblies. The constraints were to be able to control the two brazed interfaces from the same access face, with the possibility of detecting and dimensioning defects with an equivalent diameter of 0.25 mm. This phase is important to define the optimal transducer with the associated operating conditions. The first assemblies validated the preliminary choices. To exploit the cartographies obtained, a signal processing procedure was developed. This enabled an automatic characterization of the indications observed. However, the analysis of the signals observed proved to be more complex than the one predicted by the simulation. Once the origin of the various observed signals was identified it was then possible to define windows allowing the construction of the cartographies to analyze. In case of a good quality assembly, it was possible to qualify the generated beam and to image it in the focal plane but with an observed signal having a very low damping. These first encouraging results, however, show that there is still some validation and development work to increase the sensitivity of the developed translator and its damping.


2014 ◽  
Vol 896 ◽  
pp. 578-581
Author(s):  
S. Ni Made Intan Putri ◽  
Heru Setyawan

The purpose of this paper is to investigate the electrophoretic deposited nanosilica on stainless steel for corrosion protection. The electrophoretic deposition (EPD) was carried out by pulsed direct current (PDC) of silica sol made of sodium silicate. The amplitude and frequency of the PDC were varied in the range of 0.1-0.6 V and 30-80 Hz, respectively. The corrosion protection properties of the silica films were analyzed by Electrochemical Impedance Spectroscopy (EIS) in 2 wt% NaCl solution. The experimental results showed that the silica films exhibit good characteristics as indicated by their high pore resistance and low admittance. The silica film corrosion protection characteristics were influenced by the frequency and amplitude of PDC during preparation of electrophoretic deposition.


2011 ◽  
Vol 486 ◽  
pp. 139-142
Author(s):  
Chao Cheng Chang ◽  
Dinh Hiep Nguyen ◽  
Hsin Sheng Hsiao

A metal forming system comprising an electrical heater, capable of conducting processes at elevated temperatures, was developed to perform micro backward extrusion processes of SUS 304 stainless steel. Two punches with diameters of 1.6 mm and 1.8 mm were used to extrude the billets inside the die with an inner diameter of 2 mm. All processes were lubricated with water-based graphite and conducted under isothermal conditions at 400 °C. The results show that the developed extrusion system can be used to produce the stainless steel components with a micro cup-shaped profile. Moreover, the variation in the rim height of the cups produced by the 1.8 mm diameter punch is greater than the one by the 1.6 mm diameter punch. The results show that a decrease in the clearance between the punch and die could lead to an increase in the inhomogeneity of material flow in the micro backward extrusion processes.


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