Current source density

Kaba H. and Kawasaki Y. (1996). A one-dimensional current source-density analysis is applicable to the mouse accessory olfactory bulb. J Vet Med Sci 58, 485-488. 

Schroeder CE, Mehta AD, Givre SJ. 1998. A spatiotemporal profile of visual system activation revealed by current source density analysis in the awake macaque. Cereb Cortex 8 575-592. 

Aroniadou-Anderjaska V, Ennis M, Shipley MT. 1999a. Current-source density analysis in the rat olfactory bulb Laminar distribution of kainate/AMPA and NMDA receptor-mediated currents. J Neurophysiol 81 15-28. 

Rodriguez R, Haberly LB. 1989. Analysis of synaptic events in the opossum piriform cortex with improved current source-density techniques. J Neurophysiol 61 702-718. 

Martinez, D.P and Freeman, W.J. (1984) Periglomenilar cel action on mitral cells in olfactory bulb shown by current source density analysis. Brain Res., 308, 223-233... 

K. C. Cheung, P. Renaud, H. Tanila, and K. Djupsund. Flexible polyimide microelectrode array for in vivo recordings and current source density analysis. Biosens. Bioelectron., 22(8) 1783-1790, March 2007. 

Keywords— Electroencephalogram, Physical fatigue. Current Source Density, Common Average Reference. 

However, it should be noted that most of the EEG studies on physical fatigue is based on the referential EEG data. It has been pointed out by [6] that the referential method may have certain drawbacks since it is dependent on the location of the reference. Thus, it has been suggested using both the Common Average Reference (CAR) method as well as the Current Source Density (CSD) method [7] hand in hand to provide a more complete view of the EEG content. 

In this study, only the eyes closed data will be process. This is because the eyes-closed condition exists immediately after the experimental task has been completed. The EEG recordings obtained at each location is actually dependent on the reference electrode. Montages have been used to remove this reference electrode effect. The Referential (REF) method is compared with both the Common Average Reference (CAR) method as well as the Current Source Density (CSD) method. In order to compute the CSD, the software is downloaded based on the algorithm given by [7]. The formula to calculate the CAR is given by (4)... 

In order to establish the relationship between x and t, Kies developed a theory82b based on a current source which, in view of the constant current density during drop growth, should obey the equation i = at 13, so for the symbol x in connection with the current density j converted into i = bxt213. This means that by inserting the drop surface... 

Potentiostatic current sources, which allow application of a controlled overpotential to the working electrode, are used widely by electrochemists in surface kinetic studies and find increasing use in limiting-current measurements. A decrease in the reactant concentration at the electrode is directly related to the concentration overpotential, rj0 (Eq. 6), which, in principle, can be established directly by means of a potentiostat. However, the controlled overpotential is made up of several contributions, as indicated in Section III,C, and hence, the concentration overpotential is by no means defined when a given overpotential is applied its fraction of the total overpotential varies with the current in a complicated way. Only if the surface overpotential and ohmic potential drop are known to be negligible at the limiting current density can one assume that the reactant concentration at the electrode is controlled by the applied potential according to Eq. (6). 

For the usual dc measurement the constant dc current source should be capable of providing currents in the range 0.1-10 mA for a typical bar of 1 mm square cross-section, 1 cm length, and a resistivity at 100 K of 50 pOhm-cm the voltage measured for a 1 mA current source would be 1 / V. Since even for a typical low value of the critical current density, 100 A/cm2, the measurement current would be 1000 times less and thus have essentially no effect on the measurement. However, the measurement of 1 / V to a precision of 1% already requires care to assure that noise and thermal voltages are reduced well below this value. Currents of similar value are used for measurements in thin films. 

In general, controlled-current electrolyses need less expensive equipment. Only a controlled-current source in combination with a coulomb integrator is necessary. Therefore, in industry, electroorganic reactions are always performed at a fixed current density. In the laboratory, it is advisable to start with controlled-potential electrolyses using a potentiostat and a three-electrode electrolysis cell (Fig. 22.8). In this way, the reaction can be controlled at the redox potential of the substrate determined analytically, and the selectivity of the process can be studied at different potentials. After determination of the selectivity controlling factors, it is usually possible to change over to current control by proper selection of the current density and the concentration of the substrate. Using a continuous process, the concentration can be fixed at the desired value. Thus, selectivity can also be obtained under these conditions. 

First, when external current sources are used, the power consumption may be unpractically large. It all depends on the electrodic parameters of the electronation reaction—the larger its exchange-current density and the lower its Tafel slope, the larger will be the external protection current that must be used to achieve protection. 

The first source of nonequilibrium noise, described as early as 1918 (23) (in fact 10 years earlier than Johnson noise), was shot noise that stems from the discrete nature of charge transfer. The current spectral density, Sj(/), of this noise is white (independent of frequency /) up to frequencies of the order of the inverse time of elementary charge transfer and is given by... 

This solution uses a nonsquare dispersion matrix in which n > m, to obtain the necessary redundancy in concentration information. The solution is valid whether or not 4> is dependent on c, because it determines the values of (f) consistent with the current c field. The result is the source density profile in a (small) number of canopy layers, with the lowest layer including the ground source (Fq). The total flux from the canopy is also obtained as the sum of [Pg.50]

The evaluation of elements valences (charge state of an atom in compound with the ionic type of chemical bond) is especially needed for studying and designing such materials as mixed valence semiconductors based on 3d-transition metal oxides. The preliminary set electron or hole current carrier density in such materials can be created by applying the valence regulation method. Such electroconducting oxide materials are widely used as electrodes of fuel cells and other current sources, gas sensors, electric heating elements, thermistors etc. 

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