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Classical Theory of the Weak Interaction and Foundations of Nuclear Beta Decay
Published in K Grotz, H V Klapdor, S S Wilson, The Weak Interaction in Nuclear, Particle and Astrophysics, 2020
K Grotz, H V Klapdor, S S Wilson
The conservation of a weak charge, as discussed above, analogous to the conservation of the electric charge is, as already mentioned, known as conserved vector current (CVC). This term results from the fact that, in general, the conservation of a charge may be mathematically represented as ‘conservation’ of a four-current (see Subsection 4.1.1).
Effective removal of reactive blue 222 dye by electrocoagulation and ultrasound-associated electrocoagulation
Published in Journal of Dispersion Science and Technology, 2022
Zürriye Gündüz, Ahmet Günay, Cansu Özmez
From this perspective, determination tests for optimum current density have been carried out carefully to remove the RB222 dye with high efficiency but low current density. The effect of current density was investigated at four current densities of 2, 10, 20, and 40 mA/cm2, respectively. Electrochemical operations for current density were performed at initial pH 5.0 in the solution of 50 ppm and totally 30 min of electrolysis. Figure S2a–d demonstrate the increasing decolorization efficiency with increasing current density throughout the electrochemical treatment. To find out the effect of ultrasound energy on decolorization performance, electrocoagulation process was performed in an ultrasonic bath. At the low current density values of 2 and 10 mA/cm2, ultrasound displayed of power itself prominently until the 6th minute, as can be seen in Figures S3 and S4. For example, the 3rd minute EC decolorization efficiencies at current densities of 2, 10, 20, and 40 mA/cm2, were 28%, 84%, 95%, and 97%, respectively. On the other hand, USEC decolorization efficiencies were 53%, 86%, 90%, and 97%, respectively. The trend of change in yield was also clearly seen in values at other times. But it did not continue at higher current density values of 20 and 40 mA/cm2. Because at high current density, pollutant removal was achieved with a very rapid acceleration. It should also be noted that the 15 minutes of operation time was a threshold and the efficiency of both processes was equalized to achieve more than 99% color removal after 15 minutes of electrolysis.
An experimental investigation on pool boiling heat transfer enhancement using Cu-Al2O3 nano-composite coating
Published in Experimental Heat Transfer, 2019
Sanjay Kumar Gupta, Rahul Dev Misra
The two step electrochemical technique has been applied by Kim [51] and Patil et al. [42] in their pool BHT study. They fabricated copper nano-particle coating on copper surface by varying the current density from 150 mA/cm2 to 1200 mA/cm2 in the first step of deposition process. According to their studies, the lower current densities (up to 500 mA/cm2) are more effective than the higher current densities, because the surfaces developed at higher current density have higher coating layer thickness and accordingly offer higher thermal resistance. However, no or very little hydrogen bubble evolutions may result at very low current densities and thus the potential of developing intended porous surface is very minimal. Accordingly, in the present work, the current densities considered are within 150–300 mA/cm2. Further, four current density levels are considered in a uniformly increasing order from 150 mA/cm2 to 300 mA/cm2, i.e., 150 mA/cm2, 200 mA/cm2, 250 mA/cm2, and 300 mA/cm2.