Quantum radiometry

We review radiometric techniques that take advantage of photon counting and stem from the quantum laws of nature. We present a brief history of metrological experiments and review the current state of experimental quantum radiometry.     

Mechanochemical preparation of kaempferol intermolecular complexes for enhancing the solubility and bioavailability

Abstract

In this study, complexes of kaempferol (KF) with polysaccharide arabinogalactan (AG) and disodium glycyrrhizinate (Na₂GA) were prepared through mechanochemical technique to improve the solubility and bioavailability of KF. The physicochemical properties and the interactions of KF with AG/Na₂GA were investigated through dissolution, SEM, XRD, and DSC studies. The reduction of particle sizes and destruction of crystal forms revealed the formation of solid dispersion which may have assisted the dissolution of the drug. The accelerated stability study showed higher stability for KF–Na₂GA complex. In vivo pharmacokinetic study was performed to observe the plasma drug concentrations for KF complexes. Mechanochemical complexation of KF with AG/Na₂GA improved the pharmacological activity as evident by the inhibitory potential of the complexes towards carbohydrate metabolic enzymes. In vivo studies were performed in STZ-induced diabetic mice, where the group treated with KF–AG complex showed better liver and kidney function and lower blood glucose levels than pure KF. Therefore, mechanochemical complexes of KF with polysaccharide or glycyrrhizate may serve as a promising formulation for the treatment of diabetes.     

Numerical simulation of temperature stratification in an accumulation-type solar water-heating installation

Numerical study of nonstationary three-dimensional laminar convection is performed in the model of the main element of a solar water-heating installation of the accumulation type in the process of a daily cycle of heat supply. Three-dimensional velocity fields and peculiarities of temperature distributions in the tubular element of installation that are connected with formation of temperature stratification are analyzed at different angles of the element inclination to the horizon.     

Evaluation of energy efficiency of motor control modes in adjustable electric drives

Estimation methods and the results of an investigation of motor control modes energy efficiency in adjustable electric drives are considered.     

Statistical analysis of electromagnetic compatibility at overvoltage in electric mains

Problems in analyzing the statistical modeling of electromagnetic compatibility (EC) in processes linked with a rise in overvoltage and its development and influence in electric mains are analyzed. Regularities in electric equipment damage and recommendations for electromagnetic compatibility analysis with the Monte Carlo method are presented.     

Indefinite summation of rational functions with factorization of denominators

A computer algebra algorithm for indefinite summation of rational functions based on complete factorization of denominators is proposed. For a given f, the algorithm finds two rational functions g, r such that f = g(x + 1) − g(x) + r and the degree of the denominator of r is minimal. A modification of the algorithm is also proposed that additionally minimizes the degree of the denominator of g. Computational complexity of the algorithms without regard to denominator factorization is shown to be O(m ²), where m is the degree of the denominator of f.     

Recycling rare-earth-metal waste using hydrometallurgical methods

The present review describes the state of the problem of extracting rare earth metals from secondary raw materials, such as high-coercivity magnets, nickel–metal hydride batteries (NiMH), and phosphors of coatings of fluorescent lamps. Methods for waste processing with mineral acids and other solvents, the removal of associated impurities from rare-earth components, separation, and deep purification (mainly by solvent extraction) have been considered. Data on the industrial applications of hydrometallurgical processes for rare earth metals recycling have been presented.     

Photoelectrochemical Activity of Nanosized Titania,Doped with Bismuth and Lead,in Visible Light Region

Protection of Metals and Physical Chemistry of Surfaces - A method for the preparation of film coatings of titania doped with bismuth (Bi3+) and lead (Pb2+) ions, separately and simultaneously, has...     

Photoelectrocatalytic Oxidation of Formic Acid in the Visible Spectral Region on Films of Nanocrystalline Titanium Oxide Doped by Bismuth

Protection of Metals and Physical Chemistry of Surfaces - A method of formation of film coatings of titanium dioxide doped by bismuth ions (Bi3+) is developed on the basis of sol–gel...