Structure and Superconducting Properties of Cd0.8Ba2(Y0.7Ca0.4)Cu3.5Oy

A new Cd-containing superconductor with nominal composition ofCd_0.8Ba₂(Y_0.7Ca_0.4)Cu_3.5O _y was synthesized and investigated. The obtained Cd and Ca-doped 123 phase exhibits an orthorhombic (T _c=80 K) or tetragonal (T _c=65 K) modification depending on the reaction atmosphere. It was shown that the combined Cd and Ca substitution facilitates the 123 phase formation. The results of the EDX analysis, as well as the comparison of the obtained lattice parameters with those of undoped, Cd-doped, and Ca-doped 123 have shown that both Cd and Ca enter the 123 phase and form a new Cd–Ba–Y–Ca–Cu–O superconducting compound.     

Synthesis and application of triazinyl-2,2,6,6-tetramethyl-piperidine derivatives as stabilizers for polymeric materials

Two new unsaturated compounds, i. e. triazinyl-2,2,6,6-tetramethylpiperidine derivatives (TTMP), were synthesized under conditions of phase-transfer catalysis and their copolymers with styrene (St) were prepared. The participation of TTMP in the polymerization did not affect the rate of copolymerization, molecular weight and polydispersity of the St polymers. At low concentrations (0.1 wt.-%) a significant stabilizing effect against photodegradation was determined.     

Macro- and Micromechanics of Pearlitic-Steel Deformation in Multistage Wire Production

Ninefold drawing of pearlitic steel wire is investigated. On the basis of multiscale computer models, the behavior of pearlite colonies at the surface of the wire and in its central layer is analyzed. The key factors are the orientation of the cementite lamellae relative to the drawing axis, the interlamellae distance, and the shape of the cementite inclusions. On the basis of finite-element models, the laws governing the reorientation of the pearlite colonies, change in shape and size of the cementite lamellae, and localization of the deformation in the ferrite are determined. The model results are verified by means of metallographic results and industrial experiments.     

In vivo and in vitro debromination of decabromodiphenyl ether (BDE 209) by juvenile rainbow trout and common carp

Decabromodiphenyl ether (BDE 209), the major congener in the high volume industrial flame retardant mixture "DecaBDE", has recently been shown to be metabolized by carp. To further explore this phenomenon, juvenile rainbow trout were exposed to BDE 209 via the diet for a five month period. Analysis of the whole body homogenate, liver, serum, and intestinal tissues revealed that BDE 209 accumulated in rainbow trout tissues and was most concentrated in the liver. In addition to BDE 209, several hepta-, octa-, and nonaBDE congeners also accumulated in rainbow trout tissues over the same period as a result of BDE 209 debromination. Based on the total body burden of the hepta- through decaBDE congeners, uptake of BDE 209 was estimated at 3.2%. Congener profiles were different among whole body homogenate, liver, and serum, with the whole body homogenates having a greater contribution of the debrominated biotransformation products. Extracts of the rainbow trout whole body homogenates were compared with extracts from a previous experiment with common carp. This comparison revealed that BDE 202 (2,2',3,3',5,5',6,6'-octabromodiphenyl ether) was a dominant debromination product in both studies. To determine whether the observed debromination was metabolically driven, liver microsomal fractions were prepared from both common carp and rainbow trout. Analysis of the microsomal fractions following incubation with BDE 209 revealed that rainbow trout biotransformed as much as 22% of the BDE 209 mass, primarily to octa- and nonaBDE congeners. In contrast, carp liver microsomes biotransformed up to 65% of the BDE 209 mass, primarily down to hexaBDE congeners. These microsomal incubations confirm a metabolic pathway for BDE 209 debromination.     

One-step spray pyrolysis synthesized CuO-carbon composite combined with carboxymethyl cellulose binder as anode for lithium-ion batteries

Copper oxide-carbon composite with hollow sphere structure has been synthesized by a one-step spray pyrolysis method and tested as anode material for lithium-ion batteries. Different analytical methods, including X-ray powder diffraction, scanning electron microscopy, energy-dispersive X-ray spectrometry, thermogravimetric analysis, and systematic electrochemical tests were performed. The results demonstrate that the CuO-carbon composite in conjunction with carboxymethyl cellulose (CMC) binder has an excellent electrochemical performance, with a capacity of 577 mAh g(-1) up to 100 cycles. The usage of the water soluble binder, CMC, not only obviously improves the electrochemical performance, but also makes the electrode fabrication process much easier and more environmentally friendly.     

Rietveld analysis of the effect of annealing atmosphere on phase evolution of nanocrystalline TiO2 powders

The structural evolution of nanocrystalline TiO2 was studied by X-ray diffraction (XRD) and the Rietveld refinement method (RRM). TiO2 powders were prepared by the sol-gel technique. Post annealing of as-synthesized powders in the temperature range from 500 degrees C to 800 degrees C under air and argon atmospheres led to the formation of TiO2 nanoparticles with mean crystallite size in the range of 37-165 nm, based on the Rietveld refinement results. It was found that the phase structure, composition, and crystallite size of the resulting particles were dependent on not only the annealing temperature, but also the annealing atmosphere. Rietveld refinement of the XRD data showed that annealing the powders under argon atmosphere promoted the polymorphic phase transformation from anatase to rutile. Field emission scanning electron microscopy (FESEM) was employed to investigate the morphology and size of the annealed powders.     

Application of combined casting–pressing for the fabrication of aluminum wire for soldering waveguides

Technical and process features of a flowsheet for fabricating the wire of casting aluminum alloys intended to solder waveguides with the use of the combined continuous casting–pressing of nonferrous metals are considered. The dependences necessary and sufficient to design the constructive elements of equipment and process modes providing the implementation of conditions for the stable run of processes of continuous supply of the metal melt into the stream of the carousel molding laboratory machine, its solidification, and extrusion into the die opening similarly to Conform technology are established. The magnitude of the cross section of the hole in the supply dispenser of the metal melt into the stream of the crystallizer wheel is calculated. The process modes of the continuous casting–pressing using a laboratory installation of a billet 3 mm in diameter and its subsequent treatment by high-quality rolling and drawing in combination with intermediate annealing procedures to the final sizes are presented. According to this flowsheet, a pilot batch of round and square wire of alloys AK12Ts10 and AK12Ts15 has been produced in the amount of 3 kg and delivered to the AO ISS enterprise for industrial test soldering of waveguides.     

Analysis of the line broadening of diode-pumped solid-state lasers

The output parameters of the most effective system for pumping of solid-state lasers that is based on laser diode arrays are studied. The spatial profile of radiation of specific diode arrays and the differences in the radiation spectra of emitting elements are determined. It is demonstrated that the main reason for the generation of additional modes and the spectral broadening of laser radiation is related to thermal effects resulting from the spatial nonuniformity of radiation of the diode pumping system.     

Comparative characteristics of nutrition of the male population in some cities of the USSR (a cooperative study)]

The state of nutrition was studied in men of varying age groups (20-29, 30-39, 40-49, 50-54 years) living in different cities of the USSR. The standard method of food ration "daily reproduction" was used to investigate 25% of representative subsample in each age group. It has been found that the daily ration of men living in the European part of the USSR (Moscow, Kiev, Tallinn) is characterized by a rather high caloric value and by a significant imbalance in the consumption of the main food substances.     

Synthesis and characterization of Fe doped CeO2 nanoparticles for pigmented ultraviolet filter applications

Iron doped CeO2 nanoparticles with doping concentrations between 0 and 30 mol% were synthesized by the co-precipitation method for potential application as a pigmented ultraviolet filtration material. Each sample was calcined in air and in argon. The iron solubility limit in the CeO2 lattice was found to be between 10 and 20 mol%. Raman spectroscopy results revealed that both iron doping and argon calcination increase the concentration of oxygen vacancies in the CeO2 lattice. Iron doping causes a blue-shift of the absorbance spectrum, which can be linked to the decreased crystallite size, as obtained by XRD peak broadening using the Scherrer formula. The undoped samples showed weak ferromagnetic behaviour whereas the doped samples were all paramagnetic.