Low energy ionization of argon atoms by argon atoms

Ionization cross section for production of electrons by collisions between neutral argon atom

Design guide for helicopter transmission seals

A detailed approach for the selection and design of seals for helicopter transmissions is presented. There are two major types of seals presently being used and they are lip type seals and mechanical type seals. Lip type seals can be divided in conventional lip seals and hydrodynamic lip seals. Conventional lip seals can be used for slow-speed, low-pressure, low-temperature sealing. Hydrodynamic lip seals although they are as pressure and temperature limited as conventional lip seals, can operate at a higher speed. Mechanical types seals are comprised of face seals and circumferential seals. Face seals are capable of high speed, high pressure, and high temperature. Circumferential seals can be used in high-speed and high-temperature applications, but will leak excessively at moderate pressures. The performance goals of transmission seals are a life that is at least equal to the scheduled overhaul interval of the gearbox component and a leakage rate of near zero

Study of high voltage solar array configurations with integrated power control electronics

Solar array electrical configurations for voltage regulatio

Waveform Characteristics of the Canine Click Evoked Brainstem Auditory Evoked Response Across Multiple Test Sessions

The purpose of this capstone research project was to investigate the consistency of waveform characteristics of the canine click evoked brainstem auditory evoked response (BAER) across multiple test sessions. Six canines were recruited to participate in the study. Brainstem auditory evoked response recordings were measured in each ear of the canines using a click stimulus at 102 dB peSPL, 82 dB peSPL and 62 dB peSPL. Canines included in the study were between the ages of one and seven to avoid both maturation and aging affects. Characteristics assessed throughout this study at each intensity level were absolute latencies of waves I, II, III and V, interpeak latencies of waves I-II, II-V, and I-V, amplitudes of waves I, II, III and V, wave V interaural differences at 102 dB peSPL, the lowest level wave V was observed, and the overall morphology of each BAER response. Results from this study indicated the BAER test was consistent across test sessions with respect to absolute and interpeak latencies, wave V interaural latency differences, and amplitudes. Overall waveform morphology was good for the highest stimulus intensity and varied from good to poor at lower intensity levels. The lowest level at which wave V was observed was consistent for the majority of canines in this study. Findings from this study suggested the canine click-evoked BAER is a consistent assessment tool that both veterinarians and audiologists can be confident in when determining the integrity of the canine auditory system

The Case of DeCasto Earl Mayer and Mary Ellen Smith

On September 5, 1928, James Eugene Bassett left his sister\u27s home at Bremerton, Washington, with the intention of returning that evening, but was never seen again. Bassett\u27s disappearance aroused nationwide interest and he was made the object of a most intensive but unavailing search. The unanswered question remains: Could a legally sufficient case be made against any defendant for the murder of Bassett, assuming overwhelming evidence of the defendant\u27s connection with whatever catastrophe may have befallen him, but almost no independent evidence that he was dead and not merely missing? Due to an unfortunate chain of events, the question was never answered by a court of last resort. It is the purpose of this article to discuss the applicable rule and its policy, against the background of the activities of the two people who were responsible for Bassett\u27s disappearance

Some factors influencing radiation of sound from flow interaction with edges of finite surfaces

Edges of surfaces which are exposed to unsteady flow cause both strictly acoustic effects and hydrodynamic effects, in the form of generation of new hydrodynamic sources in the immediate vicinity of the edge. An analytical model is presented which develops the explicit sound-generation role of the velocity and Mach number of the eddy convection past the edge, and the importance of relative scale lengths of the turbulence, as well as the relative intensity of pressure fluctuations. The Mach number (velocity) effects show that the important paramater is the convection Mach number of the eddies. The effects of turbulence scale lengths, isotropy, and spatial density (separation) are shown to be important in determining the level and spectrum of edge sound radiated for the edge dipole mechanism. Experimental data is presented which provides support for the dipole edge noise model in terms of Mach number (velocity) scaling, parametric dependence on flow field parameter, directivity, and edge diffraction effects

Modeling and Analysis of Power Processing Systems

The feasibility of formulating a methodology for the modeling and analysis of aerospace electrical power processing systems is investigated. It is shown that a digital computer may be used in an interactive mode for the design, modeling, analysis, and comparison of power processing systems