Electrical contact loss

Galvanic corrosion is the enhanced corrosion of one metal by contact with a more noble metal. The two metals require only being in electrical contact with each other and exposing to the same electrolyte environment. By virtue of the potential difference that exists between the two metals, a current flows between them, as in the case of copper and zinc in a Daniell cell. This current dissolves the more reactive metal (zinc in this case), simultaneously reducing the corrosion rate of the less reactive metal. This principle is exploited in the cathodic protection (Section 53.7.2) of steel structures by the sacrificial loss of aluminum or zinc anodes. 

Poor choice of FR additives can lead to excessive loss of PBT molecular weight upon processing, hence leading to impaired mechanical properties (usually seen as part melt-viscosity (MV) drop and, if severe, part breakage). In some cases, generation of acidic halide species can cause mold or electrical contact corrosion. 

However, that is observed only within the range of the so-called safe voltage window of operation - for alkaline aqueous electrolytes it covers the range of l,12-l,24v, and depends on material purity and current density. Exceeding this voltage causes gassing, electrode swelling and loss of electric contact between particles in the electrode volume. 

Capacity fading — Loss of faradaic - capacity of the active mass in a -> secondary battery, i.e., reduction of the amount of electric charge which can be stored and retrieved. Numerous causes depending on the type of secondary battery maybe effective mechanical disintegration, loss of electrical contact between particles constituting the active mass, changes in chemical composition, and partial dissolution are only a few. 

Another common mode of failure of batteries is loss of electrical contact between the active material and the current collector. There are many other ways in which batteries can fail, such as the aging of separators and accidental contact between anode and cathode. These problems are not discussed here. 

A bipolar electrode consists of an anode in electrical contact with a cathode—it is polarized in the electric field of the cell. Bipolar cells have two feeder electrodes and a number of bipolar electrodes between them. Ideally, the current supplied to the system can be multiplied by the number of anodes or cathodes to calculate the charge that is passed to the electrolyte. In reality, some current losses occur due to bypass or shunt currents, so-... 

A liquid-junction interface has also been suggested and applied for CE-ESI-MS [8]. Electrical contact with this interface is established through the liquid reservoir which surrounds the junction of the separation capillary and a transfer capillary, as shown in Fig. lb. The gap between the two capillaries is approximately 10-20 fim, allowing sufficient makeup liquid from the reservoir to be drawn into the transfer capillary while avoiding analyte loss. The flow of makeup liquid into the transfer capillary is induced by a combination of gravity and the Venturi effect of the nebulizing gas at the capillary tip [8]. 

Dissipate losses are wear loss of carbide products, arc erosion of electrical contacts and electrodes, oxidation losses, losses by chemical decomposition, etc. It can only be influenced to a small extent by quality improvements of the final products. However, because the quality level today is already quite high, no drastic change can be expected. 

Loss by discard is mainly a matter of strict organization and today is not only a question of the price of tungsten. Typical examples for discard are noncollectable carbide products, burned out lamps and lighting fixtures, welding electrode stubs, electrical contact disks, carbide hard-facing materials, etc. 

The main reasons for the low efficiencies are the incomplete absorption of the solar spectrum by any single material which serves as a colorant. Self-absorption of the fluorescence by the emitting colorant. Critical cone losses of the reemitted centers, absorption and scattering of the host materials, lack of good contact between the LSC and the photovoltaic cell. Reflection of light from the metallic surfaces of which the electrical contacts are made. The decrease of performance efficiency of the collectors made of organic dyes with time are a result of photodecomposition of the colorant and polymeric host material. 

Because of the high power setting necessary to atomize molybdenum, response was often variable. As in the case of vanadium (Chapter 14), the life of the carbon rod was short. Response dropped significantly because the furnace and support rods deteriorated, resulting in loss of electrical contact and therefore lower atomization temperatures. Replacement was necessary after every 20-25 measurements. 

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