In-rush current

An Ulnstration of the in-rush current in a transformer. The effect of residual flux and hysteresis... 

It can seen that the instantaneous, and short-tenn root-mean-square, values of the primary current can be much higher than their rated values, typically by as much as 10 times. Reference 4 Chapter 5 section XIV explains the phenomenon and offers a method of calculating the shape of the first half-cycle of in-rush current. The reference also points out that if a HV/LV transformer is energised from the LV secondary terminals, the in-rush current may in some designs be up to twice the value in per unit than if the energising is carried out at the primary terminals. 

When constructing this circuit, the experimenter should use the 120V to 12V transformer, with a power cord soldered on, and insulated with tape. The 12 volt secondary is "center-tapped" with a thin black wire, and the 100 ohm resistor is attached to this, so the initial tum-on current does not rush into the empty capacitor too fast. (This is called "in-rush" current, and it can damage some components. It can also occur when heated filaments or electric motors are first turned on.)... 

Hughes CW, Emsiie GA. Treatment of anxiety disorders in children and adolescents. In Rush A, ed. Current review of mood and anxiety disorders. Baltimore Williams Wilkins,... 

Low pass filters are often used as suppression devices. A capacitor placed across the terminals is the simplest form of filter, where the impedence it should present to the transient will be much lower than the transient source impedence. This approach will work well unless the capacitor loads down the desired voltage and does not create current in-rush problems. 

More examples could be drawn, if not limited by the length of this chapter, as the field is rapidly developing. To facilitate its faster success, a much higher level of cooperation between the theory, electrochemical experiments (also in the nanoscale range [187, 188, 210]), and modified stack testing is vital. Such cooperation, however, requires a different level of openness between academia and industry, than exists in the current gold rush atmosphere of PEFC/DMFC research and development. 

As part of this circuitry, many systems also include a precharge circuit that is made up of a secondary loop with a second set of contactors that are opened to precharge the system before the main contactors are closed. This precharge contactor prevents a large current in-rush into the system. 

J. J. Rush, Current Status of Neutron-Scattering Research and Facilities in the United States, National Academy Press, Washington, DC, 1984. 

For example, with respect to driver characteristics, there is great current interest in the aging driver. We know that as drivers age, they adapt—they drive less frequently after drinking, in rush hour and bad weather, and at night. But is this positive adaptation enough to offset the negative impacts of impairment to visual and information processing ... 

When table salt (sodium chloride, NaCI), for instance, is dissolved in water, it ionizes into positively charged sodium ions (NaT) and negatively charged chlorine ions (Cl—). These ions wander about in all directions until an electric current-is applied to the solution. Wben that happens, the negative ions rush lo the positive pole, the positive ions to the negative pole. It is the ions that conduct the current through the solution. 

The gold rush in clinical trials has to stop, and prospective randomized clinical trials with a central data registry must be conducted, Only if current standards for clinical trials are met, will cell therapy be taken seriously by a large, and of course, skeptical community. Creating a consensus for preclinical and clinical data standards and conducting the studies would enable... 

Note that, in the forward bias mode for an np rectifier, electrons from the n region, which carry the so-called drift current" of majority carriers, rush... 

Initial results for the STARAD study were published early in 2006, providing useful insights for the clinician (Rush et ah, 2006 Trivedi, Fava, et ah, 2006 Trivedi, Rush, et ah, 2006). The Level I patients were all treated with the antidepressant citalopram, and only about 30% of the patients reached remission (that is, their symptoms essentially disappeared). However, about half of the patients experienced a response (a less demanding outcome measure that is commonly used in clinical drug trials and that reflects the rate of patients who experienced at least a 50% reduction in the severity of symptoms). These results are congruent with efficacy trials and with clinical experience. The results from Level I also showed that, in general, responders to treatment have a higher education, have fewer medical problems or psychiatric comorbidities, and are currently employed white women. 

Obviously, quantities hot and hi are always symbate to the respective chemical potentials and P . It is important that the difference between the logarithms of rushes fij and hj be proportional to the current thermo dynamic affinity A j of the reaction between reaction groups i and j—in other words, to the thermodynamic force Xy related to flux... 

The discussed chemical transfomiations can be visualized in the coordi nates of current chemical potential values (see Figure 2.4a), where chemi cal potentials of components R, Pj, and P2 are the external parameters. While this is the case of the absence of common intermediates, an indirect influence of the second reaction on the first reaction is possible only when chemical potential iTp2 of compound P2 (its thermodynamic rush P2) is higher than the chemical potential of compound R (its thermodynamic rush R). When so, the consecutive reaction P2 — R Pi becomes pos sible, and this compound P2 can be involved as an additional substrate into the main reaction R — Pi. In the considered example, the phenomenon of conjugation of chemical processes is not observed. The conjuga tion takes place only in the presence of common intermediates for both channels of the transformations. 

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