Steel electrodes

Electromagnetic flow meters ate avadable with various liner and electrode materials. Liner and electrode selection is governed by the corrosion characteristics of the Hquid. Eor corrosive chemicals, fluoropolymer or ceramic liners and noble metal electrodes are commonly used polyurethane or mbber and stainless steel electrodes are often used for abrasive slurries. Some fluids tend to form an insulating coating on the electrodes introducing errors or loss of signal. To overcome this problem, specially shaped electrodes are avadable that extend into the flow stream and tend to self-clean. In another approach, the electrodes are periodically vibrated at ultrasonic frequencies. 

On the other hand, CU-CUSO4 should not be used as built-in electrodes for potential test probes (see Section 3.3.3.2) because there is a danger of copper precipitating on the steel electrode. Calomel electrodes with saturated KCl solution are preferred in this case and present no problems. 

This result is immediately confirmed by the results given in Fig. 3-3. A steel electrode was cathodically polarized in a soil sludge. The potential was measured with a capillary probe IR-free as E, and without a probe as E2. The difference directly... 

Fig. 5-4 Cell currents between a coated specimen (5 = 300 cm ) and uncoated steel electrode (5 =1.2 cm ) in NaCl solutions at 25°C. Left shot-peened steel sheet, 150 pva EP-tar. Right hot-dipped galvanized steel sheet, 150 jim EP-tar.

The polarization cell is an electrochemical component in which nickel or stainless steel electrodes are immersed in 50% KOH solution [9]. With ac, the... 

Figure 9. CV of 0.2 mol kg 1 lithium bis[2,2 -biphenyldiolato(2-)-0,0 ]borate solution in PC at a stainless steel electrode, area 0.5 cm 2, showing the passivation of the electrode.

An insulated stainless steel electrode which forms one terminal in the circuit. 

Figure 19. (1) Oxidized polypyrrole (PPy) film electrogenented on a steel electrode. (2) A tape was fastened to the dry polypyrrole film (A). B is doublesided tape and C is a protective sheet of paper. (3) The bilayer device with a protective film is removed from the electrode. (4) The protective sheet is peeled off and the bilayer is ready to work. (Reprinted from Handbook of Organic Conductive Molecules ami Polymers, H.S. Nalwa, ed.,Vol. 4,1997, Figs. 10.13, 10.15a, 10.18, 10.36. Reproduced with permission of John Wiley Sons, Ltd., Chichester. UK.)...

ENA was recently used for remote on-line corrosion monitoring of carbon steel electrodes in a test loop of a surge water tank at a gas storage field. An experimental design and system for remote ENA and collection of electrochemical impedance spectroscopy (EIS) data (Fig. 13) have been presented elsewhere. In the gas storage field, noise measurements were compared with electrode weight loss measurements. Noise resistance (R ) was defined as... 

Figure 14. Representative noise data as monitored for steel electrodes exposed in a test loop at a gas storage field (a) o V(r). (b) o l(r), (c) Rn, and (d INT, .

Sengil, I.A. and Ozacar, M., Treatment of dairy wastewaters by electrocoagulation using mild steel electrodes, Journal of Hazardous Materials, 137 (2), 1197-1205, 2006. 

Mild steel electrodes, 25 20 Mileage, polypropylene, 20 526-528 Military applications... 

The Ru single crystal was oriented by Laue x<-ray back-scattering to within 1° of the Ru(001) plane, cut by a diamond saw and mechanically polished. After being etched in hot aqua regia for about 15 min, the crystal was spot welded to two tantalum heating wires which were connected to two stainless steel electrodes on a sample manipulator. The temperature was monitored by a Pt/Pt-10% Rh thermocouple which was spot welded to the back of the crystal. 

Electrochemical oxidation-reduction of eluting mixture components is the basis for amperometric electrochemical detectors. The three electrodes needed for the detection, the working (indicator) electrode, reference electrode, and auxiliary electrode, are either inserted into the flow stream or imbedded in the wall of the flow stream. See Figure 13.13. The indicator electrode is typically glassy carbon, platinum, or gold, the reference electrode a silver-silver chloride electrode, and the auxiliary a stainless steel electrode. Most often, the indicator electrode is polarized to cause oxidation of the mixture components... 

Measurement Techniques. DC polarisation curves on freshly abraded mild steel in bulk paints were determined using a traditional 3-electrode potentiodynamic technique. A 50 ml cell employed a disc mild steel electrode (area 0.33 cm ), saturated calomel reference and platinum counter electrode. Polarisation curves were made at a scan rate of 2V/Hr between -950 to -450 mV vs see. 

It was decided to carry out modifications of the highly zinc pigmented psdnt using the impedance technique to test the protective properties. Steel electrodes with the following coatings were tested ... 

Flmre 1. Electrode potential vs. Immersion time In 3 jb NaCl solution and Impedance diagrams for steel electrodes with unmodified zinc pigmented coatings. 

Figure 2, Electrode potential ts. Inmerslon time in 3 % NaCl solution and impedanoe diagrams for steel electrodes with, zino pigmented coating modified by substitution of 1 of zinc with conducting carbon blade.

Raeissi et al. [236, 237] showed that temperature, pH, and current density affected the morphology and texture, as well as the nucleation mechanism of the zinc deposits on carbon steel electrode. 

The corrosion behavior of zinc-coated steel electrodes electrochemically modified by polypyrrole [311] and zinc electrode in solution containing reducing polymer (Polyox WSR-301) [312] was investigated. 

The electrowinning of cadmium from dilute sulfate solution was studied using rotating GC and spiral wound steel electrodes [311]. 

Current was delivered to the membranes through silver/silver chloride (Ag/AgCl) electrodes for iontophoresis, whereas stainless steel electrodes were employed for electroporation studies. Of the two model compounds, L-glutamic acid carries a net negative charge of 1 at pH 7.4, whereas estradiol is nonionized. Hence, they were delivered under the cathode and anode, respectively. 

Fig. 1. Schematic representation of a chamber, for exposure of cell suspensions to low electric field. Two stainless steel electrodes separated by a 5-mm Teflon spacer are introduced into a 1-cm plastic cuvette.

The application of a typical train of pulses, when using stainless steel electrodes, resulted in small polarization of the electrodes and the appearance of a residual low DC component (<2 V). To avoid polarization, it is recommended to switch electrode polarity after each treatment and to clean and polish electrodes after each experiment. When employing stainless steel electrodes one observes, in some culture media, the formation of precipitates. It is, therefore, recommended to employ platinum electrodes, which do not lead to precipitation. 

Early experiments were concerned with the protection against water-vapor adsorption afforded a pair of soft steel electrodes by coating each with FEP Teflon resin. The two coated electrodes were cleaned as before, mounted in the gas cell, and then discharged with gaseous ions while the metal pins were grounded. The resulting contact potential difference was zero. The same result was obtained using a pair of resin-coated aluminum electrodes. 

Figure 51 Fast Fourier transform of the potential noise from two nominally identical carbon steel electrodes exposed to 0.2 M HC1 + 0.5 M NaCl + 0.15 M NaN02. (Data courtesy of J. Yuan, M. Inman, T. Lunt, J. Hudson, University of Virginia.)...

The objective of the mass transport lab is to explore the effect of controlled hydrodynamics on the rate at which a mass transport controlled electrochemical reaction occurs on a steel electrode in aqueous sodium chloride solution. The experimental results will be compared to those predicted from the Levich equation. The system chosen for this experiment is the cathodic reduction of oxygen at a steel electrode in neutral 0.6 M NaCl solution. The diffusion-limited cathodic current density will be calculated at various rotating disk electrode rotation rates and compared to the cathodic polarization curve generated at the same rotation rate. 

The LCX is punctuated distal to the flow probe with a chrome-vanadium-steel electrode (3 mm length, 1 mm diameter). The electrode (anode) is placed in the vessel in contact with the intimal lining and connected over a Teflon coated wire to a 9 Volt battery, a potentiometer and an amperemeter. A disc electrode (cathode) is secured to a subcutaneous thoracal muscle layer to complete the electrical circuit. The intima is stimulated with 150 pA for 6 h. During this time, gradually an occluding thrombosis is formed. 

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