Dilute magnetic semiconductor quantum-well structures for magnetic field tunable far-infrared/terahertz absorption

The design of ZnCdSe–ZnMnSe-based quantum wells is considered, in order to obtain a large shift of the peak absorption wavelength in the far infrared range, due to a giant Zeeman splitting with magnetic field, while maintaining a reasonably large value of peak absorption. A triple quantum-well structure with a suitable choice of parameters has been found to satisfy such requirements. A maximal tuning range between 14.6 and 34.7 meV is obtained, when the magnetic field varies from zero to 5 T, so the wavelength of the absorbed radiation decreases from 85.2 to 35.7 μm with absorption up to 1.25% at low temperatures. These structures might form the basis for magnetic field tunable photodetectors and quantum cascade lasers in the terahertz range

Magnetic field tunable terahertz quantum well infrared photodetector

A theoretical model and a design of a magnetic field tunable CdMnTe/CdMgTe terahertz quantum well infrared photodetector are presented. The energy levels and the corresponding wavefunctions were computed from the envelope function Schr¨odinger equation using the effective mass approximation and accounting for Landau quantization and the giant Zeeman effect induced by magnetic confinement. The electron dynamics were modeled within the self-consistent coupled rate equations approach, with all relevant electron-longitudinal optical phonon and electron-longitudinal acoustic phonon scattering included. A perpendicular magnetic field varying between 0 T and 5 T, at a temperature of 1.5 K, was found to enable a large shift of the detection energy, yielding a tuning range between 24.1 meV and 34.3 meV, equivalent to 51.4 μm to 36.1 μm wavelengths. For magnetic fields between 1 T and 5 T, when the electron population of the QWIP is spin-polarized, a reasonably low dark current of ≤1.4×10–² A/cm² and a large responsivity of 0.36−0.64 A/W are predicted

Evidence for coordinated induction and repression of ecto-5'-nucleotidase (CD73) and the A2a adenosine receptor in a human B cell line

In the human B cell line P493-6 two mitogenic signals, the EpsteinBarr virus nuclear antigen 2 (EBNA2) and myc, can be independently regulated by means of an estrogen receptor fusion construct or an inducible expression vector, respectively. Shut off of EBNA2, either in the presence or absence of myc, leads to a significant increase in enzymatic activity and surface expression of ecto-5nucleotidase (CD73) as well as an increased adenosine receptor response in cyclic AMP formation. Shut off of myc expression has a small additional positive effect on CD73 activity. Among the four different subtypes of adenosine receptors, the A2a receptor exclusively is subject to regulation in this system, which is substantiated by pharmacologic data (specific agonists and inhibitors), as well as on the mRNA level. With upregulated CD73 and A2a, cells also respond to 5AMP with increased cyclic AMP formation. Turn on of EBNA2 has the reverse effect of repression of CD73 and A2a expression. The time course of both induction and repression of CD73 and A2a is rather slow

DEVELOPMENT AND OPTIMIZATION OF CARVEDILOL FORMULATION USING EXPERIMENTAL DESIGN

The aim of this paper was to develop and optimize the carvedilol tablets formulation using the full factorial design. The content of binder (PVP K30), content of disintegrant (crospovidone) and main compression force were used as the independent variables. Tablets were prepared by wet granulation. The percentage of released carvedilol from prepared formulation after 10 minutes was defined as the response. It has been found that formulation with the low content of binding agents (4.8%), high content of disintegrant (4.5%) and compression force of 50 N has the best profile of drug. The optimal formulation was defined based on implementation of pharmaceuticaltechnological tests (testing strength, friability, disintegrating, contents of drug substance, drug release profiles). The stability of the optimal formulation with carvedilol was estimated using the aging tests

New Evidences on Domestication of the Horse (Equus Ferus Caballus) and Origine of Domestic Mountain Pony

The results of draft genome research of permafrost horse bone dated approximately 560-780 (kyr BP) have been published recently. According to the data representing the oldest full genome sequence compared to the modern genomes of domesticated horse, Przewalskii and donkey it was suggested that the Equus lineage gave rise to contemporary horses, zebras and donkeys some 4.0 to 4.5 million years ago, twice increasing the assumed time to the common ancestor. Upon the phylogenetic and divergence analyses it was estimated that the Przewalskii and domestic horse populations diverged some 38-72 kyr BP and that there are no evidences that admixtures between Przewalskii and domestic horse populations occurred post-divergently thus Przewalskii’s involvement in the process of horse domestication has been excluded. The new data on ancient equide genome question the conventional theory on the origin of Domestic mountain pony. Upon the protein variability of the Domestic mountain pony the influence of diluvial genome on the population was confirmed and this finding differed from the conventional theory stating E. f. Przewalskii and E. ferus caballus as ancestors of the autochthonous population. The role of different ancestral horses in evolution of our autochthonous population is therefore unclear. The questions emerging from the most recent genetic and proteomic research in concern with the autochthonous populations are presented in the paper

A Hybrid optimization method for real-time pump scheduling

Session S6-02, Special Session: Evolutionary Computing in Water Resources Planning and Management IILinear, non-linear and dynamic programming, heuristics and evolutionary computation are amongst the techniques which have been applied to obtain solutions to optimal pump-scheduling problems. Most of these either greatly simplify the complex water distribution system or require significant time to solve the problem. The scheduling of pumps is frequently undertaken in near-real time, in order to minimize cost and maximize energy savings. However, this requires a computationally efficient algorithm that can rapidly identify an acceptable solution. In this paper, a hybrid optimization model is presented, coupling Linear Programming and Genetic Algorithms. The resulting hybrid optimization model has demonstrated more rapid convergence with respect to the traditional metaheuristic algorithms, whilst maintaining a good level of reliability

Optimization of Quercetin Extraction from Green Tea (Camellia sinensis) Using Central Composite Design, and the Pharmacological Activity of the Extract

The aim of this paper was to optimize an extraction procedure of quercetin from green tea using central composite design. Extraction time, ethanol concentration, and solid to liquid ratio were selected as the independent variables, while quercetin yield was defined as a response. The impact of factors and their interactions on the quercetin yield was studied based on the results of ANOVA test. The extraction time of 58.5 min, ethanol concentration of 94.7 % (v/v), and solid to liquid ratio of 1:19.4 (m/v) were found as the optimal conditions. The experimental confirmation of the proposed optimal conditions indicated that there was a good agreement between the experimental and predicted values. In addition to quercetin, the presence of 17 bioactive compounds was confirmed in the green tea extract using mass spectrometry method. Antioxidant, antimicrobial and antitumor activity of the optimal extract was determined using DPPH assay, disk diffusion method, and MTT assay, respectively

Multi-stage linear programming optimization for pump scheduling

Open Access journalCopyright © 2013 The Authors. Published by Elsevier Ltd.12th International Conference on Computing and Control for the Water Industry, CCWI2013This study presents a methodology based on Linear Programming for determining the optimal pump schedule on a 24-hour basis, considering as decision variables the continuous pump flow rates which are subsequently transformed into a discrete schedule. The methodology was applied on a case study derived from the benchmark Anytown network. To evaluate the LP reliability, a comparison was made with solutions generated by a Hybrid Discrete Dynamically Dimensioned Search (HD-DDS) algorithm. The cost associated with the result derived from the LP initial solution was shown to be lower than that obtained with repeated HD-DDS runs with differing random seeds