Some peculiarities of electric discharge between a solid electrode and technical water

© 2016, Pleiades Publishing, Ltd.We present the results of experimental study of the electric discharge between metal electrodes of various geometry and technical water within the pressure range of 8 × 103–105 Pa at the saw-tooth voltage generator frequency, f = 40 MHz, and the interelectrode distance, l = 3–30 mm. We consider transfer of the streamer discharge into spark one depending on the geometry of the metal electrode and its material. We investigate the electrical characteristics of the discharge between the plate electrode and the technical water within a wide pressure range. The essential influence of the streamer discharge type on the ozone release within the investigated parameters range is discovered

Thermo-mechanical behavior of titanium beryllide pebble beds at elevated temperatures

The thermomechanical behavior of titanium beryllide pebble beds was investigated experimentally at temperatures between 200 and 500°C in helium atmosphere at atmospheric pressure. The pebbles consist of a mixture of TiBe12 and Ti2Be17 titanate beryllide phases and a small residual amount of Be phase, denominated as Be-7.7Ti. Like previous experiments at ambient temperature [1], the pebble beds were compressed uniaxially up to 4.5MPa and the effective thermal conductivity k was measured using the hot wire technique. Compared to ambient temperature, the stress-strain curves do not differ significantly in investigated temperature range. Because the thermal conductivity of solid TiBe12 is fairly constant in a wide temperature range [2], k increases moderately with increasing temperature because of the increasing thermal conductivity of helium. Compared to beryllium pebble beds, the k of the Be-7.7Ti pebble beds increases again much lesser because of the significantly smaller thermal conductivity of the solid material and the mechanically harder behavior resulting in smaller contact surfaces

Peculiarities of microwave discharge between a copper pin electrode and technical water

© 2014, Pleiades Publishing, Ltd. Some experimental results on burning of the microwave discharge between a copper pin electrode and technical water, in air, are presented within the ranges of the voltage U = 28–75 kV, the frequency f = 40–100 MHz, and the interelectrode space l = 2–20 mm. The essential influence of the pulse repetition frequency and the interelectrode space on the development, the shape, and the structure of the microwave discharge between the copper electrode and the technical water is revealed. Also the transition of the weakly glowing microdischarges inside the microwave discharge into the multichannel spark discharge is revealed. A temperature decrease below room temperature in the interelectrode gap of the microwave discharge with the technical water is discovered

Evaluation of clinical efficacy of prostanoid therapy for Raynaud’s phenomenon in rheumatic diseases

Aim. On the basis of clinical manifestations of Raynaud’s phenomenon (RP) to determine the RP expression level and to evaluate the long-term efficacy of treatment of RP in patients with rheumatic diseases (RD) with iloprost and alprostadil. Methods. Treatment for indications with prostanoids (intravenous iloprost, alprostadil or their combinations) was administered to 40 patients with secondary RP in RD. During 3-year follow up, clinical instrumental parameters (frequency of attacks of Raynaud's, digital ulcers (DU) formation, pain intensity on visual analogue scale (VAS) were evaluated. The control group included 30 patients with RP in RD who did not receive prostanoid therapy. The method of factor analysis was used to determine the index of generalized expression of RP, on the basis of which the expression levels of the RP were determined. Results. The “expression of RP” scale revealed in the course of factor analysis as an indicator of generalized manifestation of RP, is the average value of two subscales, the first one of which consisted of four indices - “digital ulcer”, “digital pitting scars”, “phalange amputation” and “Raynaud's attack frequency”, and the second one included “intensity of pain”, “duration of illness”, “whitening of fingers”. Verification of the correlation revealed during the study of subscales, showed its reliability (r = 0.294, p = 0.053). The final expression of RP was 1.51 ± 0.86. The low level of RP expression had values up to 0.65, high - over 2.37. When included in the study, a high level of RP expression was defined in 16 (22.9 %) patients, medium - in 43 (61.4 %), low - in 11 (15.7 %). The use of iloprost in the treatment of RP was effective for healing of DU and a statistically significant decrease of the generalized expression of RP from 2.25 [1; 3] to 1.75 [1; 2] (p = 0.012) was observed. On alprostadil treatment, statistically significantly decreased frequency of attacks from multiple daily (more than once a day) to once a month and reduced numbness during RP attack were observed as well as a decrease of the level of generalized index of RP expression from 1.26 ± 0.71 to 0.97 ± 0.57 (р = 0.038). The combination of prostanoids had a contradictory clinical effect: the pain and frequency of RP attacks decreased, but the formation of DU and new cases of amputations of phalanges were registered, the treatment had no effect on the value of RP expression. Conclusion. Based on the clinical manifestations of RP, a generalized index of RP severity was identified and the levels of RP severity were determined. Treatment with iloprost and alprostadil has a significant effect on reducing the clinical manifestations of RP with a corresponding decrease in its severity

PG 1115+080: variations of the A2/A1 flux ratio and new values of the time delays

We report the results of our multicolor observations of PG 1115+080 with the 1.5-m telescope of the Maidanak Observatory (Uzbekistan, Central Asia) in 2001-2006. Monitoring data in filter R spanning the 2004, 2005 and 2006 seasons (76 data points) demonstrate distinct brightness variations of the source quasar with the total amplitude of almost 0.4 mag. Our R light curves have shown image C leading B by 16.4d and image (A1+A2) by 12d that is inconsistent with the previous estimates obtained by Schechter et al. in 1997 - 24.7d between B and C and 9.4d between (A1+A2) and C. The new values of time delays in PG 1115+080 must result in larger values for the Hubble constant, thus reducing difference between its estimates taken from the gravitational lenses and with other methods. Also, we analyzed variability of the A2/A1 flux ratio, as well as color changes in the archetypal "fold" lens PG 1115+080. We found the A1/A2 flux ratio to grow during 2001-2006 and to be larger at longer wavelengths. In particular, the A2/A1 flux ratio reached 0.85 in filter I in 2006. We also present evidence that both the A1 and A2 images might have undergone microlensing during 2001-2006, with the descending phase for A1 and initial phase for A2. We find that the A2/A1 flux ratio anomaly in PG 1115 can be well explained both by microlensing and by finite distance of the source quasar from the caustic fold.Comment: 14 pages, 7 figures, 8 tables, Accepted for publication in MNRA