Increasing the corrosion resistance of equipment due to the use of film-forming amines

Results of a study of tube specimens cut from hot-water boilers show that film-forming octadecyl amine (ODA) used in the process of preservation removes deposition from the surface of the metal. An ODA film is preserved on the surface after repeated washing of the latter with hot water. The concentration of chlorides at the surface of the metal after treatment with ODA is lower than before the treatment. __________ Translated from élektricheskie Stantsii, No. 11, November 2005, pp. 15–18.     

Spectral dependence of the optical rectification effect in nanographite films

The spectral dependence of the optical rectification effect in nanostructured carbon (nanographite) films obtained by plasmachemical deposition was studied in a wavelength range from 266 to 1900 nm. In this range, the amplitude of the electric signal observed when films were irradiated by nanosecond light pulses of constant power increases in inverse proportion to the laser wavelength. The experimental results confirm the assumptions made previously concerning the mechanism of the observed effect. It is suggested that nanographite films are promising materials for detectors of ultrashort laser pulses in the IR, visible, and UV spectral intervals and for generators of electromagnetic radiation operating in the terahertz frequency range.     

Structural Stability of SrCo<Subscript>1 − <Emphasis Type="Italic">x</Emphasis></Subscript>Fe<Subscript>x</Subscript>O<Subscript>3 − δ</Subscript> Solid Solutions

SrCo_{1 − x} Fe_xO_{3 − δ} solid solutions with 0.3 ≤ x ≤ 0.9 are shown to have the cubic perovskite structure. The unit-cell parameter and volume of the solid solutions are nonmonotonic functions of Fe content, with a minimum at x = 0.4. Dilatometric data are used to determine the thermal expansion coefficients of the solid solutions. At low oxygen partial pressures ( ≤ 40 Pa), the high-temperature, disordered perovskite phase exists between 850 and 1000°C, which is the optimal temperature range for the effective use of SrCo_{1 − x} F_xO_{3 − δ} ceramics as oxygen membranes in oxygen partial pressure gradients of 10⁴–10⁵/10–100 Pa.__________Translated from Neorganicheskie Materialy, Vol. 41, No. 8, 2005, pp. 998–1004.Original Russian Text Copyright © 2005 by Kokhanovskii, Zonov, Ol’shevskaya, Pan’kov.     

A device for testing a fast nanographite photodetector at high temperatures

The results of tests of a fast photodetector based on a nanographite film grown on a silicon substrate are presented. The temperature dependence of the optoelectric signal from the photodetector in the range 300–800 K has been studied under the vacuum conditions. It has been shown experimentally that, when the temperature increases from 300 to 625 K, the photodetector’s sensitivity decreases by approximately 30%. When the temperature increases to higher values, the optoelectric-signal amplitude drops linearly and is halved at T = 740 K as compared to room temperature. Extrapolation of the experimental data shows that the optoelectric response of the photodetector disappears at T > 1000 K.     

Laser-induced surface vortex current in a thick film resistor

We have discovered a photoelectric skin effect and detected decaying high-frequency current excited in a silver-palladium thick film resistor under the action of pulsed laser radiation.     

Lead-Free Paint Coatings for Glass Articles

The effect of binders on the quality of paint coatings based on lead-free enamels and meeting the requirements of standard TU RB 100029049.030 is considered. It is established that enamel compositions can be prepared using 20% solution of oxyterpene resin in turpentine and 2% alcoholic solution of Na-carboxymethyl cellulose of grade 7MF. The use of an aqueous solution of dextrin as a binder deteriorates the quality of enamel coatings: it produces color modifications, loss of luster, and formation of crackle.     

Efficiency of a fast-response nanographite-based optoelectric converter in air at high temperatures

The effect of heating and subsequent cooling in air on the efficiency of optoelectric conversion in a nanographite (NG) film irradiated by nanosecond laser pulses of constant power has been studied. It is established that an increase in the temperature of heating in the T = 300–600 K interval leads to an approximately 30% decrease in the amplitude U of the optoelectric response signal. The further increase in the temperature is accompanied by a linear decrease in the U value. The U(T) dependence remains single-valued for NG films heated up to T = 530 K with the subsequent keeping at this temperature for no less that 10 h and cooling. Heating of the NG film above 640 K followed by exposure at this temperature leads to irreversible changes in the optoelectric conversion efficiency.     

A Nanographite Film-Based Fast Response Detector for Intense Laser Radiation

A simple high-speed photodetector of high-power laser radiation, based on the optical rectification effect, is described. It operates without an external power source. A nanographite film deposited onto a silicon substrate using the plasmochemical deposition technique and having two conducting surface electrodes is used as the photodetector’s photosensitive element. The performance of this device was demonstrated by detecting pulsed laser radiation in a spectral range of 0.266–1.9 µm using the second, third, and fourth harmonics of radiation from an YAG : Nd³⁺ laser with passive Q-switching and radiation from light oscillators based on stimulated Raman scattering in compressed hydrogen. It was shown that the photodetector sensitivity is proportional to the optical radiation frequency and its response time is shorter than 0.5 ns.__________Translated from Pribory i Tekhnika Eksperimenta, No. 3, 2005, pp. 84–89.Original Russian Text Copyright © 2005 by Mikheev, Zonov, Obraztsov, Svirko, Volkov.