A lens holographic-moiré technique to obtain components of displacements and derivatives

A symmetrical-double-beam illumination technique is combined with holographic-plate rotation around an axis in its own plane and with lens holography to obtain components of displacement in two- and three-dimensional bodies, or also the derivatives of the displacements. A pipe under internal pressure has been utilized to obtain components of displacement and disk under diametral compression is used to obtain derivatives of displacements. A very good agreement is obtained between holographic results and elasticity-theory solution.     

Functional properties of nisin–carbohydrate conjugates formed by radiation induced Maillard reaction

Nisin–carbohydrate conjugates were prepared by irradiating nisin either with glucose or dextran. Increase in browning and formation of intermediate products was observed with a concomitant decrease in free amino and reducing sugar groups indicating occurrence of the Maillard reaction catalyzed by irradiation. Nisin–carbohydrate conjugates showed a broad spectrum antibacterial activity against Gram negative bacteria (Escherichia coli, Pseudomonas fluorescence) as well as Gram positive bacteria (Staphylococcus aureus, Bacillus cereus). Results of antioxidant assays, including that of DPPH radical-scavenging activity and reducing power, showed that the nisin–dextran conjugates possessed better antioxidant potential than nisin–glucose conjugate. These results suggested that it was possible to enhance the functional properties of nisin by preparing radiation induced conjugates suitable for application in food industry.     

Spin-down of the von Karman flow

The decay of the fluid flow due to a rotating disk is analysed when the disk is stopped suddenly. The interaction of the induced Rayleigh flow and the initial von Karman flow results in the establishment of a boundary layer whose characteristics are studied in detail. Solutions representing the initial and final stages of the spin-down are supplemented by the numerical solution of the governing equations.     

A new calix[4]arene based nucleobase for cation recognition

A novel calix[4]arene linked nucleobase molecular receptor bearing two adenine moieties has been synthesized and characterized by UV, IR, NMR and ESI–MS analyses. The synthesized receptor can recognize biologically important Zn²⁺ and Mn²⁺ ions through 1:1 binding stoichiometry. The evaluation of binding constants suggests that adenine alone, in an appropriate supramolecular network, can exhibit efficient binding for Zn²⁺ ions without the presence of any phosphate or sugar unit.     

Magnetically guided fast electrons in cylindrically compressed matter

Fast electrons produced by a 10 ps, 160 J laser pulse through laser-compressed plastic cylinders are studied experimentally and numerically in the context of fast ignition. K(α)-emission images reveal a collimated or scattered electron beam depending on the initial density and the compression timing. A numerical transport model shows that implosion-driven electrical resistivity gradients induce strong magnetic fields able to guide the electrons. The good agreement with measured beam sizes provides the first experimental evidence for fast-electron magnetic collimation in laser-compressed matter.     

Room temperature ferromagnetism in Zn1−xCoxS thin films with wurtzite structure

The magnetic properties of Zn_1−xCo_xS (x=0.025 and 0.05) thin films grown on α-quartz substrates at different temperatures (T_S) of 200, 400 and 600 °C by means of pulsed laser deposition are presented. The films are crystallized with wurtzite structure. Optical absorption and transmission electron microscopy measurements indicate that Co ions are substituted to Zn on tetrahedral sites. Their magnetic response is composed of ferromagnetic and paramagnetic components of which respective strengths depend on T_S and Co concentration. This behavior is interpreted as due to fluctuations in the magnetic ordering, depending on grain size and site location in grain boundaries or in crystal cores.     

Performance of CeO2–TiO2-admixed photoelectrode for natural dye-sensitized solar cell

Extracts from roots of Beta vulgaris were used as natural sensitizers of a wide-bandgap semiconductor (CeO₂–TiO₂) in photoelectrochemical solar cells. The natural dye, adsorbed onto the semiconductor surface, absorbs visible light and promotes electron transfer across the dye/semiconductor interface. We have applied CeO₂–TiO₂ to natural dye sensitizer solar cells as a photoelectrode to reduce the charge recombination rate by providing energy barrier at the interface between the photoanode and electrolyte which offers an improvement of photovoltaic efficiency. Short-circuit current density (J _sc) and open-circuit voltages (V _oc) of 9.0 mA cm^?2 and 680 mV, respectively, were obtained, and an effective energy conversion efficiency of 3.5?% was achieved. This simple and cheap technique of cell preparation opens up a perspective of commercial feasibility for inexpensive and environment-friendly dye cells.     

Spectrophotometric determination of ruthenium with diphenylthiovioluric acid

Diphenylthiovioluric acid (DPHTVA) reacts with ruthenium(III) to form a complex which has an absorbance maximum at 520 nm. Effects of pH, heating time, buffer and reagent have been studied. DPHTVA has been found to be a sensitive reagent for ruthenium(III) (sensitivity = 0.0044 μg Ru/cm² for log I₀/I = 0.001), and has been made selective by the use of masking agents. The composition of the complex as revealed by different methods is 1:2 (ruthenium:DPHTVA).     

Optimal approximate formulas with polynomial precision

For any given linear functional bounded over the Hardy spaceH ², we obtain explicitly optimal approximate formulas, with polynomial precision, based on nodes lying equispaced on |z|=r. In particular, we obtain optimal formulas with polynomial precision for interpolation, numerical differentiation and integration.