Micromorphology,pharmacognosy, and bio‐elemental analysis of an important medicinal herb: Verbascum thapsus L.

The present study was conducted on characterization of morpho‐anatomical, phytochemical, and bio‐elemental analysis of root, stem, and leaf of Verbascum thapsus. Morphologically Verbascum is a biennial plant that flowers for a month and a half in mid‐ to late summer. Various organoleptic features of root, leaf, and stem were recorded. Anatomically the T. S of the root, stem, and leaf showed a typical dicot histological differentiation. Leaf possessed anomocytic stomata, crescent shape vascular bundles, and covered with long and stellate type trichomes while, stem contained collateral type of vascular bundles and a well‐developed pith to store phytochemicals responsible for various pharmacological activities. The powder drug study through scanning electron microscopy revealed the presence of various types of tissues. Branched, tree like and stellate trichomes in root and leaf help in absorption and reduce loss of water. These anatomical features are responsible for the survival of the plant as biennial. Four macro elements (Na, K, Ca, and Mg) and seven microelements (Cr, Cu, Fe, Mn, Ni, Zn, and Cd) and their concentrations in ppm were also studied using Atomic Absorption Spectroscopy. Phytochemical screening of methanolic extract showed existence of various secondary metabolites, while mucilage and anthraquinones was not detected. The present study helps to understand the taxonomic identification of the plant based on morpho‐anatomical features and throws the attention of the researchers to carry out the work for developing its various formulations, which can ultimately be beneficial for the human beings as well as animals.     

Acceleration and heating of powder particle by gas detonation products in channels with a conical passage

The results of numerical modeling and experimental realization of the impact of a chemically reacting gas flow on powder particles during profiling (diameter increase while maintaining volume) of the barrel combustion chamber of a unit for detonation spraying are given. The passage from the combustion chamber into the barrel muzzle is made using connecting taper sleeves with a small narrowing angle. It is shown that such profiling can significantly reduce the barrel size without compromising the technological capabilities of the detonation unit.     

The enhanced photocatalytic activity of Na0.9Mg0.45Ti3.55O8 co‐loaded with silver and platinum

Noble metals Ag and Pt were loaded on Na_0.9Mg_0.45Ti_3.55O₈ (NMTO) by chemical bath deposition method, which was synthesized firstly in our recent work. The scanning electron microscopy and transmission electron microscopy results show that Ag and Pt nanoparticles were distributed on the different surfaces of NMTO. NMTO loaded with Ag and Pt can efficiently enhance the separation of photogenerated electron‐hole pairs, exhibiting much higher photodegradative ability for methylene blue and rhodamine B than the pure NMTO. The best weight concentrations of Ag and Pt are 9.00% and 3.70%, respectively. The electrostatic field is built in the Schottky barrier between NMTO and noble metals, leading to the energy band bending. Then, photogenerated electrons and holes are efficiently separated to enhance the photocatalytic activity.     

Investigation of the reaction products of unsymmetrical dimethylhydrazine with potassium permanganate by gas chromatography-mass spectrometry

The gas chromatography-mass spectrometry technique was used to investigate the composition of the reaction products of unsymmetrical dimethylhydrazine with a potassium permanganate and potassium permanganate-hydrogen peroxide mixture. If the water contamination level is within 50 threshold limit values (TLV) (1 mg/ml), the proposed detoxication method utilizing potassium permanganate in combination with hydrogen peroxide allows for the reduction of the UDMH concentration to a safe level without the accumulation of transformation products. The detoxication of aqueous solutions with significant UDMH concentrations (up to 50000 TLV) (1 g/l) with potassium permanganate alone or in combination with hydrogen peroxide reduces the UDMH concentration to a safe level, but UDMH transformation products, including the extremely toxic nitrozodimethylamine, are accumulated in the solution.     

An experimental study of the effect of nonuniform axisymmetric magnetic field on the breaking of the current of a vacuum-arc discharge

An experimental investigation is made of the effect of breaking of current in a vacuum-arc discharge as a result of superposition of a pulsed axisymmetric magnetic field with longitudinal and transverse components. A study is made of the dependences of the probability of breaking of current on the current magnitude, the pulse amplitude of the magnetic field, and the value of emf of the electric circuit in the current range of 100 to 600 A. The main factors affecting the probability of breaking of current are analyzed.Translated from Teplofizika Vysokikh Temperatur, Vol. 42, No. 6, 2004, pp. 850–855.Original Russian Text Copyright © 2004 by E. F. Prozorov, K. N. Ulyanov, and V. A. Fedorov.     

Thermal transitions of resveratrol on a carbon black surface

Methods of thermogravimetric analysis, differential scanning calorimetry, and thermal desorption mass-spectrometry are used to study the processes of thermolysis of resveratrol on the surface of graphitized thermal carbon black (GTCB). The results obtained in thermolysis of pure resveratrol and resveratrol adsorbed on GTCB from diethyl ether are compared. The regions of maximum evolution of thermolysis products are determined; their compositions are identified; an increase in thermal stability of resveratrol supported on the surface of graphitized thermal carbon black is observed.     

Use of overdriven detonation in coating application

Overdriven detonation waves allow one to produce coatings of high-melting powder materials and improve the quality of coatings sprayed from lower-melting-point materials. The kinetic and thermal energies of detonation products behind the front of overdriven detonation waves are much higher than those behind the front of self-sustained Chapman-Jouguet detonation waves traditionally used in spray processes. This paves the way toward the design of small-size spraying guns including those for applying coatings on the inner surfaces of parts.