Fundamental solutions in the theory of microfluids

This paper is concerned with the theory of non-heat-conducting microfluids. We consider a specialized microfluid continuum theory in which the micromotions consist of the intrinsic rotations and stretch. First, we establish a representation of Galerkin type for the solutions to the field equations. Then, we derive the fundamental solutions for the differential system governing the motion in the case of steady vibrations.      

SiO2-Coated ZnO Nanoflakes Decorated with Ag Nanoparticles for Photocatalytic Water Oxidation

Many strategies have been adopted to improve the photoinduced features of zinc oxide nanostructures for different application fields. In this work, zinc oxide has been synthesised and decorated by plasmonic metal nanoparticles to enhance its photocatalytic activity in the visible range. Furthermore, an insulating layer of SiO₂ has been grown between the surface of zinc oxide nanoflakes and silver nanoparticles. A synthetic procedure that allows the accurate modulation of the insulating layer thickness in the range 5–40 nm has been developed. Evidences highlight the crucial role of the SiO₂ layer in dramatically increasing photocatalytic water oxidation promoted by the nanostructure under both UV and visible illumination. An ideal thickness value of about 10 nm has been demonstrated to guarantee the plasmon-induced resonance energy-transfer process and to quench the Förster resonance energy-transfer mechanism; thus, optimising the local surface plasmon resonance effect and water oxidation properties.     

A Newly Designed Water Soluble Uranyl-Salophen Complex for Anion Recognition

A novel water-soluble uranyl-salophen (salophen=N,N‘-disalicylidene-o-phenylenediaminate) complex was obtained. Solubility was achieved in aqueous methyl-β-cyclodextrin solutions, taking advantage of the host-guest interactions established with the adamantyl moieties present on the ligand skeleton. Such an approach facilitates the synthesis of the receptor and the purification processes and, in perspective, can be definitely applicable to other molecular scaffolds. UV/Vis titration experiments demonstrate that the capacity of the uranyl-salophen core to behave as a receptor for anions is retained in water and appears comparable with that previously reported for other water-soluble uranyl-salophen systems. Hence the presence of cyclodextrins does not interfere with molecular recognition processes.     

Collective gyromagnetic ratio from density dependent hartree-fock calculations: (II). Odd nuclei

The collective gyromagnetic ratio and moment of inertia of deformed odd-proton and oddneutron axially symmetric nuclei have been calculated in the cranking approximation using wave functions obtained with the Skyrme force SIII. Good agreement with experiment is found for g_R. Our parameter-free cranking results are better than those of Prior, Boehm and Nilsson where effective charges were used. The cranking formula leads to better results than the projection method (in which one simply takes the expectation value of the relevant operator in the deformed HF ground state, neglecting corrections of relative order 1/〈J²〉. In particular, the cranking results follow nicely the exceptionally large/small g_R for the odd-proton/neutron nuclei around mass 153–167.     

Multi-photon processes in a strong field

We treat an N-level system in a strong monochromatic field. The formal solution is shown to be a matrix continued fraction. The ensuing spectrum is evaluated numerically for a model four-level system.     

A formulation of the eddy current problem in the presence of electric ports

The time-harmonic eddy current problem with either voltage or current intensity excitation is considered. We propose and analyze a new finite element approximation of the problem, based on a weak formulation where the main unknowns are the electric field in the conductor, a scalar magnetic potential in the insulator and, for the voltage excitation problem, the current intensity. The finite element approximation uses edge elements for the electric field and nodal elements for the scalar magnetic potential, and an optimal error estimate is proved. Some numerical results illustrating the performance of the method are also presented.     

Simulations of Water Flow Through Bordered Pits of Conifer Xylem

Bordered pits between tracheids play an important role in the water conductivity of conifer xylem. There have been many attempts to model xylem as a water conducting medium, and to estimate its permeability. As the microscopic structure of xylem is highly complex, it is however very difficult to numerically solve the flow equations. New methods have recently been developed by which the flow is simulated rather than found by solving appropriate equations. In this work the lattice-Boltzmann method was used to simulate the flow in bordered pits of conifer xylem, and their permeability was thereby determined. To this end the permeability of two-dimensional screens was also analyzed.     

Determination of 3,4-dihydroxyphenylglycol (DHPG) by HPLC with coulometric detection, and correlation with 3-methoxy-4-hydroxyphenylglycol (MHPG) in human plasma

A method for determining plasma 3,4-dihydroxyphenylethyleneglycol (DHPG), a central noradrenaline (NA) metabolite, is described. The method used HPLC with dual coulometric detection set in screen mode of operation. The isolation of DHPG and related catecholamines (noradrenaline, dopamine and dihydroxybenzylamine) was performed on acid washed alumina extracted with 0.2 M HCIO4 containing EDTA (0.2%), and reduced glutathione as stabilizer. A reversed phase column with an eluting system containing 0.025 M citric acid-sodium hydrogen phosphate buffer in the ratio 3:2 (v:v) and 5% methanol was used. The experimental results of plasma DHPG levels compared favourably with the results from the literature, and a positively significant correlation with plasma MHPG was found. This method could be used as an alternative in central NA assessment.     

Wavelet-based discrimination of isolated singularities masquerading as multifractals in detrended fluctuation analyses

Nonlinear Dynamics - The robustness of two widespread multifractal analysis methods, one based on detrended fluctuation analysis and one on wavelet leaders, is discussed in the context of...