Transport Coefficients from Extremal Gauss-Bonnet Black Holes

We calculate the shear viscosity of strongly coupled field theories dual to Gauss-Bonnet gravity at zero temperature with nonzero chemical potential. We find that the ratio of the shear viscosity over the entropy density is $1/4\pi$, which is in accordance with the zero temperature limit of the ratio at nonzero temperatures. We also calculate the DC conductivity for this system at zero temperature and find that the real part of the DC conductivity vanishes up to a delta function, which is similar to the result in Einstein gravity. We show that at zero temperature, we can still have the conclusion that the shear viscosity is fully determined by the effective coupling of transverse gravitons in a kind of theories that the effective action of transverse gravitons can be written into a form of minimally coupled scalars with a deformed effective coupling.Comment: 23 pages, no figure; v2, refs added; v3, more refs added; v4, version to appear in JHE

Near-Infrared Alcohol Detection Circuit Based On Multisim

Because the number of private cars has expanded, drunk driving has become more and more frequent. The detection of a driver’s alcohol concentration has become the focus of attention. Therefore, infrared alcohol detection was studied. The principle of infrared blood glucose noninvasive detection was investigated, and it was compared with infrared spectrum detection. Finally, using transmission technology and an infrared emitter and receiver, an infrared alcohol identification circuit was designed by NBohr’s Law and the Correcting Beer-Lambert Law. It was composed of an infrared acquisition circuit, an infrared electronic filter circuit, and an infrared amplifier circuit. And the infrared alcohol identification circuit was composed of multiple circuits in series and parallel. At various pins on the first AD844AN, the infrared electronic filter circuit receives an alternating current source voltage of 1000V with a basic signal frequency of 60 Hz. At the input end, the infrared amplifier circuit receives a current signal with a frequency of 1 Hz and an amplitude of 5 uA and performs the reproduction experiment using Multisim. As a result of the signal being upgraded to fulfill the objective of recognition, distinct information reappears and exhibits different waveforms