Peculiarities of the mechanism of electroreduction of cinnamic acid in DMF and DMF-H<Subscript>2</Subscript>O mixture

The electrochemical behavior of cinnamic acid (CA) on the cathodes with a high hydrogen overpotential (Hg, glassy carbon, and carbositall) in the aprotic solvent (DMF) and in DMF with additions of H₂O or Et₄NOH is studied by the methods of polarography, preparative electrolysis, cyclic voltammetry (CVA), coulometry, and chronoammetry. It is found that the mechanism of CA electroreduction is in conflict with the classical notion of the mechanism of electroreduction of α,β-unsaturated carboxyl compounds. It is shown that in the aprotic solution, in contrast to similar carbonyl compounds or ethers, which are the derivatives of organic acids, the products of double-bond hydrogenation, rather than the dimeric compounds, are the only products of CA electroreduction, i.e the presence of carboxyl group changes essentially the direction of electrochemical process. From the data of CVA, it is concluded that stable dimeric associates are present in the DMF solutions in the equilibrium with nondissociated CA.     

Energy absorption buildup factors of some potential bioactive compounds in the energy region 0.015–15 MeV

Kinetic energy released per unit mass relative to air and energy absorption buildup factors has been calculated for some potential bioactive compounds in the energy region of 0.015–15?MeV. The bioactive compounds of 1-aryl-3-dibenzylamino-propane-1-on hydrochloride type Mannich bases were used in this work. Aryl part was changed as C₆H₅ (1), 4-CH₃C₆H₄ (2), C₄H₃S-2-yl (3), 4-FC₆H₄ (4), 4-BrC₆H₄ (5), 4-ClC₆H₄ (6), and 4-NO₂C₆H₄ (7). The energy absorption buildup factors have been calculated for penetration depth of 40 mean free paths. It is observed that kinetic energy released per unit mass relative to air depends on the photon energy and chemical content of compounds. The compounds with least mean atomic number possess the maximum value of energy absorption buildup factors. Also, the energy absorption buildup factors are found the highest in intermediate energy, whereas the lowest in low as well as high energies.     

IC-100 accelerator complex for scientific and applied research

Industrial production of nuclear filters has been implemented at the IC-100 cyclotron complex of the Laboratory of Nuclear Reactions at the Joint Institute for Nuclear Research. After the complete upgrade, the cyclotron was equipped with the superconducting ECR ion source and the system of external axial beam injection. The implantation complex was equipped with the special transportation channel with the beam scanning system and the setup for irradiation of polymer films. Intense beams of heavy ions Ne, Ar, Fe, Kr, Xe, I, and W with an energy of ～1 MeV/nucleon were obtained. the properties of irradiated crystals were studied, different polymer films were irradiated, and several thousands of square meters of track membranes with pore densities varying in a wide range were produced. Other scientific and applied problems can be solved at the cyclotron complex.     

Analysis of ores by simple grinding and circular thin-layer chromatography and the nichrome wire ring chamber

Summary A method for the preparation of ore solutions by grinding the ore with distilled water is developed for the analysis of minerals and ores in the field by the circular thin-layer Chromatographic technique.

---

Zusammenfassung Die Herstellung von Erzlösungen durch Mahlen des Erzes mit dest. Wasser zur Feldanalyse von Mineralen und Erzen durch Ring-Dünnschichtchromatographie wird empfohlen.

     

Specific laws of polymer fracture

The results of an experimental verification of the activation concept of strength, first proposed by the author in 1952, are described. The theoretical conclusions are confirmed by tests on various vulcanizates, polystyrene, polymethyl methacrylate, cellophane, and polypropylene, New means of improving the strength of polymers are suggested.Mekhanika Polimerov, Vol. 4, No. 3, pp. 474–482, 1968     

Effect of bond strength on the breaking strength of two-layer cellophane film materials

The effect of bond strength on over-all tensile strength has been investigated in relation to two-layer materials consisting of cellophane film cut in the longitudinal and transverse directions and bonded with polyisobutylene. It is shown that there is a linear correlation between the bond strength and the combination hardening effect. The breaking stress of two-layer materials is higher than that of the individual films. A possible explanation of this effect is proposed.Mekhanika Polimerov, Vol. 3, No. 1, pp. 89–94, 1967     

Synthesis of non-symmetrical 3,5-diamidobenzyl amines, ethers and sulfides

A straightforward synthesis of non-symmetrical 3,5-diamidobenzyl amines, ethers and sulfides starting from 3,5-dinitrobenzoic acid is reported. Functionalization of the benzylic position is only achieved after formation of the two amides, otherwise benzylic hydrogenolysis occurs during nitro group reduction.     

Ensemble of a subset of <Emphasis Type="Italic">k</Emphasis>NN classifiers

Combining multiple classifiers, known as ensemble methods, can give substantial improvement in prediction performance of learning algorithms especially in the presence of non-informative features in the data sets. We propose an ensemble of subset of kNN classifiers, ESkNN, for classification task in two steps. Firstly, we choose classifiers based upon their individual performance using the out-of-sample accuracy. The selected classifiers are then combined sequentially starting from the best model and assessed for collective performance on a validation data set. We use bench mark data sets with their original and some added non-informative features for the evaluation of our method. The results are compared with usual kNN, bagged kNN, random kNN, multiple feature subset method, random forest and support vector machines. Our experimental comparisons on benchmark classification problems and simulated data sets reveal that the proposed ensemble gives better classification performance than the usual kNN and its ensembles, and performs comparable to random forest and support vector machines.