We present a string theory that reproduces the large-N expansion of two dimensional YangMills gauge theory on arbitrary surfaces. First, a new class of topological sigma models is introduced, with path integrals localized to the moduli space of harmonic maps. The Lagrangian of these harmonic topological sigma models is of fourth order in worldsheet derivatives. Then we gauge worldsheet diffeomo...

Sigma-delta modulated systems have a number of very appealing properties and are, therefore, heavily used in analog to digital converters, amplifiers, and modulators. This paper presents new results which indicate that they may also have significant potential for general purpose arithmetic processing. The paper introduces new arithmetic processing structures for ternary (i.e., +1, 0, or −1) sig...

we introduce the notions of t-dual rickart and strongly t-dual rickart modules. we provide several characterizations and investigate properties of each of these concepts. it is shown that every free (resp. finitely generated free) $r$-module is t-dual rickart if and only if $overline{z}^2(r)$ is a  direct summand of $r$ and end$(overline{z}^2(r))$ is a semisimple (resp. regular) ring. it is sho...

Sigma factors are essential global regulators of transcription initiation in bacteria which confer promoter recognition specificity to the RNA polymerase core enzyme. They provide effective mechanisms for simultaneously regulating expression of large numbers of genes in response to challenging conditions, and their presence has been linked to bacterial virulence and pathogenicity. In this study...

Perovskite solar cells have shown considerable developments in the last decade, and commercial applications are drawing closer. In this article, we present a techno-economic study of perovskite PV technologies. We...

This paper proves Lee-Lee's conjecture that establishes a coincidence between the set of associated roots non-self-intersecting curves in an n-punctured disc and real Schur acyclic (valued) quivers with n vertices.

Introduction: Bacteria have at least one sigma factor (σ-factor) that transcribes the genes required for cell viability. Usually, transcription of σ-factors occurs and changes in response to a variety of environmental stresses. Expression of σ-factors is one of the strategies which is used in response to different stress conditions. This study was aimed to evaluate the effects...