A study on generalized quasi-power increasing sequences

In the present paper, we have proved a general theorem dealing with an application of quasi (β-σ)-power increasing sequences. This theorem also includes several new results.     

Interpretation of transport measurements in ZnO-thin films

In order to interpret results of temperature dependent Hall measurements in heteroepitaxial ZnO-thin films, we adopted a multilayer conductivity model considering carrier-transport through the interfacial layer with degenerate electron gas as well as the upper part of ZnO layers with lower conductivity. This model was applied to the temperature dependence of the carrier concentration and mobility measured by Hall effect in a ZnO-layer grown on c-sapphire with conventional high-temperature MgO and low-temperature ZnO buffer. We also compared our results with the results of maximum entropy mobility-spectrum analysis (MEMSA). The formation of the highly conductive interfacial layer was explained by analysis of transmission electron microscopy (TEM) images taken from similar layers.     

Positive solutions for fractional four-point boundary value problems

In this paper, a fractional four-point boundary value problem is considered. By means of fixed-point theorems and successive iteration method, some results on the existence, multiplicity and uniqueness of positive solutions are obtained.     

Complex of laser processing techniques for production of fine-meshed grids of refractory materials

Laser processing techniques were used for production of fine-meshed control grids for cathode assemblies. In this paper we discuss the features of development and production of grids made of refractory materials with concentric arrangement of meshes and wires. Two different types of grid structures are studied: a pyrographite grid with thin wires and a molybdenum grid with small round meshes. The grid with concentric arrangement of meshes is connected with multibeam field-emission cathode which is also produced by laser processing techniques. High-performance, high-speed laser microperforation allows one to obtain high convergence between grid and cathode. The paper also contains an estimation of the defect zone size after the action of the laser.     

Sample pretreatment strategies for total reflection X-ray fluorescence analysis: A tutorial review

In the last years, there has been a revival of total reflection X-ray fluorescence spectrometry (TXRF), which was firstly applied for analytical purposes in the late 80s. The aim of this work is to discuss and compare the current approaches for sample pretreatment including in situ microdigestion, slurry preparation, acid digestion, extraction, etc. prior to TXRF analysis. Advantages and drawbacks inherent to each of those procedures are considered. A comprehensive revision in the period January 2008–July 2013 about different sample preparation strategies prior to TXRF analysis apart from early pioneering reports dealing with sample pretreatment are included in the review. Non-conventional sample pretreatment approaches such as microflow online preconcentration, lab-on-a-chip, etc., are also discussed.Finally, future prospects in sample preparation prior to TXRF analysis are outlined.     

Fokker–Planck equation on fractal curves

A Fokker–Planck equation on fractal curves is obtained, starting from Chapmann–Kolmogorov equation on fractal curves. This is done using the recently developed calculus on fractals, which allows one to write differential equations on fractal curves. As an important special case, the diffusion and drift coefficients are obtained, for a suitable transition probability to get the diffusion equation on fractal curves. This equation is of first order in time, and, in space variable it involves derivatives of order α, α being the dimension of the curve. An exact solution of this equation with localized initial condition shows departure from ordinary diffusive behavior due to underlying fractal space in which diffusion is taking place and manifests a subdiffusive behavior. We further point out that the dimension of the fractal path can be estimated from the distribution function.     

Spectral characterization and antibacterial effect of 2-methyl-6-(5-H-Me-Cl-NO <Subscript>2</Subscript>-1<Emphasis Type="Italic">H</Emphasis>-benzimidazol-2-yl)-phenols and some transition metal complexes

2-Methyl-6-(5-H-methyl-chloro-nitro-1H-benzimidazol-2-yl)-phenols( HL _x :x= 1-4)ligands and HL₁ complexes with Fe(NO₃)₃, Cu(NO₃)₂, AgNO₃, Zn(NO₃)₂ have been synthesized and characterized. The structures of the compounds were confirmed on the basis of elemental analysis, molar conductivity, magnetic moment, FT-IR, ¹H-and ¹³C-NMR. Antibacterial activity of the free ligands, their hydrochloride salts and the complexes were evaluated using the disk diffusion method in dimethyl sulfoxide as well as the minimum inhibitory concentration dilution method, against nine bacteria. While HL₁ ligand has not any activity, it’s Ag(I) complex show antibacterial effect toward almost to all the bacteria. Zn(II) complex has antibacterial effect on especially K. pneumoniae, S. epidermidis and S. aureus bacteria.