Modification of Bushing Test Rig and Research of Variable Inlet Guide Vane Bushings For Further Development of PM304 Bushings

PS304 is a high temperature solid lubricant coating comprised of a nickel-chrome binder, chrome oxide hardener, barium-calcium fluoride high temperature lubricant, and silver as the low temperature lubricant. This coating is used to lubricate Oil-Free Foil Air Bearings as they experience friction and wear during start up and shut down. The coating deposition process begins with undercutting the shaft. This area is then sandblasted to provide a rough surface for the coating to adhere to. The coating powder is then sent through the plasma spray gun and a reasonably thick layer is applied to the undercut area of the shaft. The coating is then ground down even with the surface of the shaft and gets a nice polished finish. The foil air bearings use the solid lubricant, as mentioned above, during start up and shut down. During normal operating conditions, generally above 2000RPM, the bearings utilize air as their lubricant. Foil air bearings are comprised of a thin top foil and a corrugated bump foil. They have an interference fit with the shaft before operation. As the air gets "trapped" between the top foil and the shaft, it presses the top foil against the bump foil, in turn compressing the bumps. As the bumps compress, it allows for the air to separate the top foil from the shaft, therefore, utilizing the trapped air as its lubricant

Asteroseismology of KIC 8263801:Is it a member of NGC 6866 and a red clump star?

We present an asteroseismic analysis of the Kepler light curve of KIC 8263801, a red-giant star in the open cluster NGC 6866 that has previously been reported to be a helium-burning red-clump star. We extracted the frequencies of the radial and quadrupole modes from its frequency power spectrum and determined its properties using a grid of evolutionary models constructed with MESA. The oscillation frequencies were calculated using the GYRE code and the surface term was corrected using the Ball & Gizon(2014) prescription. We find that the star has a mass of $M/M_{\odot} = 1.793\pm 0.072$, age $t=1.48\pm 0.21$ Gyr and radius $R/R_{\odot} = 10.53\pm 0.28$. By analyzing the internal structure of the best-fitting model, we infer the evolutionary status of the star KIC 8263801 as being on the ascending part of the red giant branch, and not on the red clump. This result is verified using a purely asteroseismic diagnostic, the $\epsilon_{c}-\Delta\nu_{c}$ diagram which can distinguish red giant branch stars from red clump stars. Finally, by comparing its age with NGC 6866 ($t=0.65 \pm 0.1$ Gyr) we conclude that KIC 8263801 is not a member of this open cluster

Coupling functions for lead and lead-free neutron monitors from the latitudinal measurements performed in 1982 in the research station Academician Kurchatov

The latitudinal behavior of intensities and multiplicities was registered by the neutron monitor 2 NM and the lead-free neutron monitor 3 SND (slow-neuron detector) in the equator-Kaliningrad line in the Atlantic Ocean. Coupling coefficients for 3 SND show the sensitivity of this detector to primary particles of cosmic rays of energies on the average lower than for 2 NM. As multiplicities increase, the coupling coefficients shift towards higher energies

The STM32 microcontroller based pulse intensity registration system for the neutron monitor

We present the outlines of a new microcontroller based data acquisition system which is aimed for reliable operation in a typical cosmic ray particle registration experiment. The system supports connection of up to 16 input signals and ensures the following operation functionality: (1)stable monitoring of the intensity of a digital pulse signal, or digitization of a continuous potential level with a low time resolution (typically, in the limits of 1-100s); (2)registration of a continuous high-resolution (up to 5-10us) time series of the intensity of input signal; (3)synchronization of registered time series with both external (physical) or local (program-based) trigger signal; (4)possibility of an on-the-fly change of the whole configuration of informational system (both the combination and type of input signals, time resolution and sum duration of the time series measurements, trigger logic, etc) immediately in operation time through convenient communication with a plain text message in dialog mode. In particular, the considered system is applied now for a long-term, high precision measurement of the counting rate of neutron signals at the NM64 type neutron supermonitor of the Tien~Shan mountain cosmic ray station, with a real-time representation of the whole collected dataset in a WWW database.Comment: communication at ISVHECRI 2016 and at the "10 Years Neutron Monitor Database" NMDB Worksho

Ground increase of cosmic ray intensity on February 16, 1984

The event of February 16, 1984 is one of the two largest ground increases of solar cosmic rays (CR) in the last two cycles of solar activity. This event happended at a decrease of the 21-st cycle against a quiet background. Although at the beginning of 1984 the observed indices of solar activity were higher than those at the end of 1983, the day of February 16 16 may be characterized as very quiet. On that day the geomagnetic perturbance (Sigma F sub p = 14, A sub p = 7) was the lowest in February. After a small Forbush decrease due to the magnetic storm of February 12-13, the CR intensity almost completely recovered by February 16. Thus, the solar particles that came to the Earth on February 16 got into a practically unperturbed magnetosphere, and the variations of secondary CR induced by these particles were not superimposed on any other substantial variations of extraterrestrial or magnetospheric origin

The minimally invasive treatment of ureteropelvic junction obstruction: a review of our experience during the last decade.

PURPOSE: The minimally invasive treatment of ureteropelvic junction obstruction has evolved during the last decade from endoscopic to laparoscopic and robotic. We review our 10-year experience with ureteropelvic junction obstruction, and report on our experience and followup. MATERIALS AND METHODS: We reviewed all patients treated during the last 10 years. There were 294 procedures performed with complete records on 273 patients including 128 retrograde endopyelotomies, 116 laparoscopic pyeloplasties and 29 robotic pyeloplasties. Technique for each procedure is reviewed. Statistical analysis was performed on all results. Variables evaluated were gender, age (younger than 41 vs 41 years or older), side (right or left), presence of crossing vessels, presence of a high insertion, primary or secondary procedure and whether prior endopyelotomy or pyeloplasty had been performed. RESULTS: Mean followup for endopyelotomy, laparoscopic pyeloplasty and robotic pyeloplasty was 20, 20 and 19 months, respectively, with success rates of 60.2%, 88.8% and 100%, respectively. On univariable analysis only the presence of crossing vessels or a high insertion was significant for laparoscopic pyeloplasty. On multivariable analysis age was significant for endopyelotomy and the presence of crossing vessels was significant for pyeloplasty. On Kaplan-Meier analysis failures were noted to occur after 5 years in both groups. CONCLUSIONS: Laparoscopic pyeloplasty and robotic pyeloplasty are superior minimally invasive treatments for ureteropelvic junction obstruction. However, endopyelotomy can be used for select patients. Because of late failures patients who undergo either of these procedures should receive long-term followup