Electrochemical Redox Cycling Realized by Chromatography Paper-based Sensor

In this work, we demonstrated that enhancement of electrochemical current due to redox cycling could be accomplished by paper-based biosensor without any expensive micro-fabrication process. The paper-based sensor had layered structure to generate higher current than a conventional one. We took advantage of the fact that the paper thickness was micrometer-sized (180um), and it defined the distance between two electrochemical electrodes on both sides of the paper. Experimental results showed signatures of the redox cycling, where the electrochemical current from low concentration molecules could be arbitrarily increased by decreasing the distance between electrodes. Such a structure was advantageous for detecting target molecules at very low concentration, proposing a low-cost highly-sensitive biochemcal sensor.

Canonical Equivariant Cohomology Classes Generating Zeta Values of Totally Real Fields

It is known that the special values at nonpositive integers of a Dirichlet $L$-function may be expressed using the generalized Bernoulli numbers, which are defined by a canonical generating function. The purpose of this article is to consider the generalization of this classical result to the case of Hecke $L$-functions of totally real fields. Hecke $L$-functions may be expressed canonically as a finite sum of zeta functions of Lerch type. By combining the non-canonical multivariable generating functions constructed by Shintani, we newly construct a canonical class, which we call the Shintani generating class, in the equivariant cohomology of an algebraic torus associated to the totally real field. Our main result states that the specializations at torsion points of the derivatives of the Shintani generating class give values at nonpositive integers of the zeta functions of Lerch type. This result gives the insight that the correct framework in the higher dimensional case is to consider higher equivariant cohomology classes instead of functions.Comment: 18 pages, Updated version with minor correction

Development of High Efficiency Swing Compressor for R32 Refrigerant

In the age of global warming, energy saving features and overall reduction of environmental impact are critical components that must be addressed when developing new HVAC units. We chose the R32 refrigerant, with its lower LCCP as a more sustainable choice than the R410A. However, R32 has its drawbacks. Due to its smaller molecular weight, internal leakage loss is higher for the R32. Moreover, high discharge gas temperature decrease the reliability of the compressor, and make a large overheating loss increase. In this study, we will describe the technologies that were developed to overcome these drawbacks. We will also present the performance and reliability of the newly developed high efficiency swing compressor series for R32 refrigerants