Defining Sets of Full Designs with Block Size Three II

A defining set of a t?(v, k, ??) design is a subcollection of its blocks which is contained in a unique t-design with the given parameters. A minimal defining set is a defining set, none of whose proper subcollections is a defining set. The spectrum of minimal defining sets of a design D is the set {|M| | M is a minimal defining set of D}. The unique simple design with parameters ${{t-\left(v, k, \begin{array}{ll}\left(\begin{array}{ll}v-t\\ k-t\end{array}\right)\end{array}\right)}}$ is said to be the full design on v elements. This paper studies the minimal defining sets of full designs when t = 2 and k = 3. The largest known minimal defining set is given. The existence of a continuous section of the spectrum comprising asymptotically 9v ²/50 values is shown. This gives a quadratic length section of continuous spectrum where only a linear section with respect to v was known before.     

Some families of generating functions for a class of bivariate polynomials

The main purpose of this paper is to present various families of generating functions for a class of polynomials in two variables. Furthermore, several general classes of bilinear, bilateral or mixed multilateral generating functions are obtained for these polynomials.     

Depending on the electric and magnetic field of the linear optical absorption and rectification coefficient in triple quantum well

In this study, the alteration of the potential profile, the energy levels, the dipole matrix element and the resonant peaks of the linear optical absorption (OA) and optical rectification (OR) coefficients in GaAs/GaAlAs triple quantum well (TQW) are calculated as dependent on the applied electric field and the magnetic field. The results show that the shape of confined potential profile, the energy levels and the dipole moment matrix elements are changed as dependent on the external fields. Also, the resonant peaks of the OA and OR coefficients depend on the applied external field effects. Therefore, I hope that these results will provide important improvement in semiconductor device applications, for suitable choice of electric and magnetic field values. It may particularly be useful in technological applications that the structure of TQW changes with the strength and direction of the external electric field.     

Intersubband transitions and refractive index changes in coupled double quantum well with different well shapes

In this study, both the linear intersubband transitions and the refractive index changes in coupled double quantum well (DQW) with different well shapes for different electric fields are theoretically calculated within framework of the effective mass approximation. Results obtained show that intersubband transitions and the energy levels in coupled DQW can importantly be modified and controlled by the electric field strength and direction. By considering the variation of the energy differences, it should point out that by varying electric field we can obtain a blue or red shift in the intersubband optical transitions. The modulation of the absorption coefficients and the refractive index changes which can be suitable for good performance optical modulators and various infrared optical device applications can be easy obtained by tuning applied electric field strength and direction.     

New Urea Biosensor Based on Urease Enzyme Obtained from Helycobacter pylori

The urease enzyme of Helicobacter pylori was isolated from biopsy sample obtained from antrum big curvature cell extracts. A new urea biosensor was prepared by immobilizing urease enzyme isolated from Helicobacter pylori on poly(vinylchloride) (PVC) ammonium membrane electrode by using nonactine as an ammonium ionophore. The effect of pH, buffer concentration, and temperature for the biosensor prepared with urease from H. pylori were obtained as 6.0, 5 mM, and 25 °C, respectively. We also investigated urease concentration, stirring rate, and enzyme immobilization procedures in response to urea of the enzyme electrode. The linear working range of the biosensor extends from 1 × 10(-5) to 1 × 10(-2) M and they showed an apparent Nernstian response within this range. Urea enzyme electrodes prepared with urease enzymes obtained from H. pylori and Jack bean based on PVC membrane ammonium-selective electrode showed very good analytical parameters: high sensitivity, dynamic stability over 2 months with less decrease of sensitivity, response time 1-2 min. The analytical characteristics were investigated and were compared those of the urea biosensor prepared with urease enzyme isolated from Jack bean prepared at the same conditions. It was observed that rapid determinations of human serum urea amounts were also made possible with both biosensors.     

Synthesis,characterization, spectroscopy,X-ray structure and gaussian hybrid computational investigation of (−)-(S)-1-[2-(benzenesulfonamido)-3-phenylpropanoyl]-4-[(4-methyl)phenyl]thiosemicarbazide

Abstract

The molecule (?)-(S)-1-[2-(benzenesulfonamido)-3-phenylpropanoyl]-4-[(4-methyl)phenyl] thiosemicarbazide was synthesized and its structure analyzed by X-ray diffraction to understand its geometry, and inter/intra-molecular interactions. Theoretical calculations were carried out using DFT and TD-DFT methods with B3LYP/6-31G(d, p) and B3LYP/6-31G?+?(d, p) basis sets. Theoretical bond parameters, harmonic vibration frequencies, and chemical shifts are in good agreement with the experimental results. Electronic properties of the molecule derived from frontier orbitals, molecular electrostatic potential, and theoretical UV-Visible spectrum are validated experimentally.     

Development of antimicrobial cotton fabric using bionanocomposites

In order to provide antimicrobial activity to cotton, cotton fabrics were treated by montmorillonite (KSF), montmorillonite–dihydroxy ethylene urea (KSF–MDEU), KSF–chitosan (CS) and KSF–CS–MDEU solutions containing 12.5, 25 and 50 ppm silver ion. The effect of modification on the antibacterial activity of cotton fabrics was also evaluated after 10 cycles of washings. MDEU exhibited better antimicrobial activities after washing process. By using 25 ppm silver, KSF and CS modification solution, good performance in terms of antibacterial activity was obtained. The addition of CS and MDEU increased the whiteness index values of cotton fabrics treated with KSF containing different silver concentrations. The characterization of modified cotton samples was done by Fourier transform infrared spectroscopy, X-ray diffraction analysis, inductively coupled plasma-mass spectroscopy, scanning electron microscopy and thermogravimetric analysis.