We show that the complex PT -symmetric periodic potential V (x) = −(iξ sin 2x+ N)2, where ξ is real and N is a positive integer, is quasi-exactly solvable. For odd values of N ≥ 3, it may lead to exceptional points depending upon the strength of the coupling parameter ξ. The corresponding Schrödinger equation is also shown to go over to the Mathieu equation asymptotically. The limiting value of...

A logical explanation as to why the choice of

Shuying Zhang Faculty Mentor: Yan Zeng Department of Pharmacology Fall 2012 Foremost, I would like to express my sincere gratitude to my advisor Prof. Yan Zeng for the continuous support of my study and growing, for his patience, motivation, enthusiasm, and immense knowledge. His guidance helped me in all the time of research and writing of this report. I could not have imagined having a better...

background and objectives: psychrotrophic bacteria can produce enzymes at low temperatures; this provides a wide biotechnological potential, and offers numerous economical advantages over the use of mesophilic bacteria. in this study, extracellular protease production by psychrotrophic rheinheimera sp. (km459533) was optimized by the response surface methodology. materials and methods: the cult...

s of PH. D. Theses Title: The Elaboration of Simulation Systems in sustainable agriculture Author: Dorian Drucioc Promotor: Dr.h. , Prof. Valentin Osadcii Date of defence: September 16, 1999 Institution: Free International University of Moldova

Background: Hydrocarbons degradation is principally achieved by microorganisms in natural environments. The extent of hydrocarbons biodegradation is mainly conditioned by environmental factors and its success depends on the optimal condition for the crude oil degrading isolates. Objectives: The aims of the current study was to isolate and identify crude oil degrading bacterium from surface sed...