Current vectorial

We can immediately identify two parity conserving terms, which arise from the scalar products of the two vectorial currents with the coupling coefficients Qy, Qy on the one hand and of the two axial currents with coupling coefficients 9, 9 on the other hand. In addition, we obtain two parity violating contributions from the two axial current-vectorial current couplings, which are often abbreviated as Vf Af and A/,V/j. Each of these terms has a time-like and a space-like component. 

As noted above, jC in Eq. (154) arises from terras in which p 7 v. The corresponding contribution to the four current was evaluated in [104,323] and was shown to yield the polarization cuirent. Our result is written in teims of the magnetic field H and the electric field E, as well as the spinor four-vector v / and the vectorial 2x2 sigma raatiices given in Eq. (151). 

The summated current is the sum of all the CT secondary currents of the different circuits. The rating of the instrument connected on the secondary of the summation CT should be commensurate with the summated current. The error of measurement is now high, as the errors of all individual CTs will also add up vectorially. 

It is possible that the stationary-state situations leading to an active ion transport occur only in localized regions of the membrane, i.e., at ATPase molecule units with diameters of about 50 A and a length of 80 A. The vectorial ion currents at locations with a mixed potential and special equipotential lines would appear phenomenologically like ionic channels. If the membrane area where the passive diffusion occurs is large, it may determine the rest potential of the whole cell. 

Transporters, particularly those carrying nonlipophilic species across biomembranes or model membranes, can be regarded as vectorial catalysts (and are also called carriers, translocators, permeases, pumps, and ports [e.g., symports and antiports]). Many specialized approaches and techniques have been developed to characterize such systems. This is reflected by the fact that there are currently twenty-three volumes in the Methods in Enzymology series (vols. 21,22,52-56,81,88,96-98,125-127,156-157, 171-174, and 191-192) devoted to biomembranes and their constituent proteins. Chapters in each of these volumes will be of interest to those investigating transport kinetics. Other volumes are devoted to ion channels (207), membrane fusion techniques (220 and 221), lipids (14, 35, 71, and 72), plant cell membranes (148), and a volume on the reconstitution of intracellular transport (219). See Ion Pumps... 

The ability to express a nonsinusoidal waveform as a sum of sinusoidal waves allows us to use the more common mathematical expressions and formulas to solve power system problems. In order to find the effect of a nonsinusoidal voltage or current on a piece of equipment, we only need to determine the effect of the individual harmonics and then vectorially sum the results to derive the net effect. Figure 4.4 illustrates how individual harmonics that are sinusoidal can be added to form a nonsinusoidal waveform. 

The principles of a.c. circuits necessary for the comprehension of some of the ideas and concepts presented here are given in Appendix 2. The impedance is the proportionality factor between potential and current if these have different phases then we can divide the impedance into a resistive part, R, where the voltage and current are in phase, and a reactive part, Xc = l (oCy where the phase difference between current and voltage is 90°. As shown in Appendix 2, it is often easier for posterior calculation and analysis to display the impedance vectorially in complex-plane diagrams. 

We need to calculate the vectorial sum of the currents shown in Fig. A2.3b. Thus... 

Fig. A2.3. Resistance and capacitance in parallel (a) Electrical circuit (b) Diagram showing the vectorial sum of the resistive and capacitive currents for a parallel RC combination (c) Complex-plane impedance plot.

The flows may have vectorial or scalar characters. Vectorial flows are directed in space, such as mass, heat, and electric current. Scalar flows have no direction in space, such as those of chemical reactions. The other more complex flow is the viscous flow characterized by tensor properties. At equilibrium state, the thermodynamic forces become zero and hence the flows vanish... 

Vectorial Character of Current Kohlrausch s Law of the Independent Migration of Ions... 

In the phenomenological treatment of the directed drift that the field brings, we take the attitude that there is a stream of cations going toward the negative electrode and anions going toward the positive one. We now neglect the random diffusive movements they do not contribute to the vectorial flow that produces an electrical current. 

Figure 25. (A) Vectorial electron transfer in the two-heme-reconstituted de novo protein molecules organized as a monolayer at an electrode surface. (B) Transient current recorded with the two-heme reconstituted de novo protein monolayer during the double-potential step chronoamperometric experiment. The potential steps from -0.2 to -0.5 V (vs. SCE) to reduce the hemes in the protein, and after 70 ms the potential steps back, from —0.5 to —0.2 V, to oxidize the reduced hemes. The experiment was performed in 0.1 M phosphate buffer, pH 7.0, under argon.

Fig. 12.3. Current model for vectorial translation depicted for one of the subunits of acetylcholine receptor. The various events are described in the text. ER, endoplasmic reticulum SRP, signal recognition particle.

Z. Brener, Biology of Trypanosoma cruzi, Ann. Rev. Microbiol., 27 (1973) 347-382 A. Moncayo, Chagas Disease Current epidemiological trends after the interruption of vectorial and transfusional transmission in the southern cone countries, Mem. Inst. Oswaldo Cruz, 98 (2003) 577-591. 

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