Non-destructive ultrasonic investigation of the structure state of steam pipelines

The main purpose of the work is to study the dependence of the ultrasonic wave parameters on the structure state in tubes of boilers at thermo-electric power station. The changes of the velocity, spectra and attenuation of ultrasonic surface waves are caused by degradation of the structure and can be used for residual life estimation of the equipment.     

Optical properties of chemical vapor deposited thin films of molybdenum and tungsten based metal oxides

Thin films of tungsten oxide, molybdenum oxide and mixed MoO₃–WO₃ oxides were obtained by atmospheric pressure chemical vapor deposition (CVD). All the films were prepared using identical technological parameters and through investigation of the optical properties of as deposited and annealed at 400°C a comparative study is reported. Raman, IR and VIS spectrophotometry and spectral ellipsometry methods were used. The mixed MoO₃–WO₃ films have higher optical absorption with maxima at a closer position with respect to the human eye sensitivity peak at 2.5 eV. The observed electrochromic effect is better expressed in the mixed films; the electrical charge inserted is higher.     

Low cost surface passivation for p-type mc-Si based on pseudobinary alloys (Al2O3)x(TiO2)1−x

The conventional process for back side passivation with full face Al screen printing layer is not suitable for very thin multicrystalline (mc-Si) solar cells and approaches to new technological processes are searched for. More investigations have been concentrated on local aluminum contacts and passivation coatings with different layers on mc-Si wafers. The aim of this work is to prove that (Al₂O₃)_x(TiO₂)_1−x is one promising candidate to be applied as passivation layer on multicrystalline Si. Investigations were performed on dielectric films of pseudobinary alloy (PBA) (Al₂O₃)_x(TiO₂)_1−x, prepared by chemical solution deposition known initially as sol–gel method. It was determined that their optical, dielectric and electrophysical properties are suitable for applications of these layers as back side surface passivation for thin multicrystalline silicon cells.     

Changes in the properties of Ovilan fibre during the texturizing process

Conclusions Before untwisting, a complex viscose yarn consists of a set of variously crimped elementary filaments with nonidentical degrees of extensibility and crimp.The geometric characteristics of the crimp depend on the location of the section of elementary filament in the complex yarn and have a random character. The crimp of the elementary filaments which make up a complex viscose yarn does not have the elastic extensibility which is inherent to synthetic yarns which are textured by the twisting method.The starting mechanism of crimp formation is caused by an artificially developed nonuniform morphology of the elementary filaments.Translated from Khimicheskie Volokna, No. 4, pp. 32–33, July–August, 1985.     

Antibodies to bacterial antigens and autoantigens in pregnant women with kidney diseases

The levels of antibodies (Ab) to bacterial antigens of gram-negative enterobacteria (Reglicolipid), Streptococcus agalactiae polysaccharide, Staphylococcus aureus teichoic acid, native and denatured DNA and renal proteins in healthy pregnant women and in those with renal pathology (chronic and gestation pyelonephritis) were studied. The study revealed that the combination of an elevated levels of Ab to bacterial antigens with the elevated titers of Ab to DNA and renal proteins is indicative of acute inflammation in kidneys, and but the combination of an elevated levels of Ab bacterial antigens with the low level of Ab to DNA and renal proteins is indicative of healthy carrier state with respect to a given infective agent.     

Identification of mRNA, localized at various segments of the Xenopus laevis embryo at early stages of the gastrula

METHODS: In a randomized double-blind study, 134 patients were given 500 mg metronidazole as an intravenous infusion immediately before operation for abdominal total hysterectomy and again 8 hours later and 124 patients received placebo. RESULTS: There was more wound infection, postoperative hospitalization was longer and the sedimentation rate on the sixth postoperative day was significantly higher in the placebo group. There was no difference in postoperative temperature. Postoperative wound infections occurred in 12% in the placebo group and 6% in the metronidazole group. Eight percent in the total material had urinary tract infections, the diagnosis was based on urine cultures. CONCLUSIONS: Prophylaxis with intravenous infusion of metronidazole is recommended in total hysterectomies.