Weak currents

He then considered the currents in the Sakata-Okun model for which he derived the expressions for the electromagnetic and weak currents. 

At that time, on the northwestern shelf of the Black Sea, weak currents up (to 0.10 ms-1) along the outer front of the desalinated area off the Danube River mouth were observed. As was noted in [23], the MRC features almost no... 

In addition to the described type of polarization there is a further type of polarization, which is due to the slowness of one or several processes taking place at the electrodes during disoharge and ion formation. Consequently, the electrodes are disturbed in their equilibrium conditions and their potentials exceed their values corresponding to the state when a very weak current or none at all flows through the electrodes. ) Concentration polarization, overvoltage and passivity are these types of polarization and will be dealt with in detail later on. 

The electrically feasible reaction conditions are (I) the extent of the reaction space and (2) the quantity of reactive ions in the latter, i.e. the concentration of the ions can be regulated in a purely electrical way and within the broadest limits. The highest dilutions can be realized just as well with weak currents and large electrode surfaces as the highest concentrations with strong currents and small surfaces. That most important factor of reaction kinetics, the reaction velocity, is thus determinatively influenced by these concentrations. The importance of the reaction velocity is especially fundamen-... 

The sO Called spheroidal state, in which a drop of water or other volatile liquid rolls about on a hot metal plate (or on the surface of a boiling liquid) with only very slow evaporation, is mainly a consequence of the very slow transmission of heat from the solid through the thin layer of vapour separating it from the liquid drop. A beam of light may be passed between the drop and the plate. Poggendorff said that an electric current will not pass from the drop to the hot plate, but Buff showed that a weak current passes and that the drop oscillates, sometimes touching the support. Stark showed that the drop is supported by a layer of vapour but executes oscillations which may sometimes reach the support. 

A weak radioactive source such as americium is used in some smoke detectors. Radiation from the source ionizes the air to produce a weak current. Smoke particles interrupt the current flow by attracting the ions. This decrease in current triggers the alarm. 

A very convenient form of measuring temperatures is now at our disposal in the form of electrical thermometers., These are of twofold construction they may be either resistance or contact thermometers. In the resistance thermometers, use is made of the fact that the resistance of a metal to the passage of a current depends upon the temperature, so that if, for instance, a platinum wire is exposed to the heat of a furnace and a weak current is passed through it, that current will affect the needle of a galvanometer according to the temperature of the wire. The contact thermometer, on the other hand, depends upon the fact that if two pieces of different metals, as, for instance, an iridium and a platinum wire, are placed in contact,... 

If you have metal fillings in your teeth, you may have received an eiectric shock after biting down on a bit of aiuminum foii. The aiu-minum foii acts as an anode, and the siiver-mercury amaigam, an aiioy, in the fiiiing acts as a cathode. The saiiva in your mouth serves as an eiectroiyte. The gai-vanic ceii in your mouth is short-circuited when the foil comes into contact with the filling, causing a weak current to flow between the electrodes. This current is detected as pain by the nerve of the tooth. 

Figure 20.13 Measurement of water by the Karl Fischer volumetric technique. The titration ceU contains volumetric burettes (which may be automated) and two small platinum electrodes. As long as no iodide is present in solution the electrodes remain polarized and only a weak current circulates between them. Once the equivalence point is reached, an excess of iodine will cause the depolarization of the electrodes and a significant current is registered.

Anyone who bites a piece of aluminum foil (such as that used for wrapping candies) in such a way that the foil presses against a dental filling will probably experience a momentary sharp pain. In effect, an electrochemical cell has been created in the mouth, with aluminum (P = -1.66 V) as the anode, the filling as the cathode, and saliva as the electrolyte. Contact between the aluminum foil and the filling short-circuits the cell, causing a weak current to flow between the electrodes. This current stimulates the sensitive nerve of the tooth, causing an unpleasant sensation. 

PtuiiBio Acid— PbO,H —256.9—forms ciystalline plates, at the + eleo-trode, when alkaline solutions of the Pb salts are decomposed by a weak current. 

Kompanets, A. Kukudzhanov, V. Letokhov, L. Gervits, Narrow resonances of saturated absorption of the asymmetrical molecule CHF-ClBr and the possibility of weak current detection in molecular physics. Opt. Commun. 19 (1976) 414-416. 

R. Cahn, G. Kane, Parity violations in hydrogen and the fundamental structure of the weak current, Phys. Lett. D 71 (1977) 348-352. 

Ritchie claims that formation of lead—acid batteries could reach close to the theoretical electric charge, 241 Ah kg PbO, if conducted with weak current for a period of at least two weeks. However, battery manufacturers cannot afford such a long formation time. The general strive is to complete the formation process within 15—30 h, and even less. This is associated with 1.7—2.5-fold increase in electricity consumed per 1 kg of dry paste. New formation current and voltage algorithms are aimed to reduce substantially the above energy consumption. 

The four nonrelativistic operators of Eq. (4a) arise from an expansion of the lepton wave functions, while those of Eq. (4b) occur in the hadronic weak current, connecting the large and small components of nucleonic wave functions, and are relativistic. Matrix elements of different rank contribute incoherently to the decay rate. The rank R has the selection rule... 

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