Scanning Mobility Particle Sizer (SMPS) spectrometers are subject to several restrictions when a radioactive source is employed to bring the aerosol to a steady-state charge distribution. An alternative solution, comm...Scanning Mobility Particle Sizer (SMPS) spectrometers are subject to several restrictions when a radioactive source is employed to bring the aerosol to a steady-state charge distribution. An alternative solution, commercially available, is represented by the soft X-ray neutralizer. The present study investigates the outcome of a combination of a Grimm SMPS, which employs a 241Am radioactive source, with the soft X-ray advanced aerosol neutralizer (TSI model 3087). To date, the latter device has been interfaced only with TSI’s Electrostatic Classifiers. Particle size distribution of sodium chloride aerosol was measured with both neutralizers and it was found that the particle number concentration agreed to be within 9% for the 10 - 700 nm range. This difference mainly corresponds to the bias reported by TSI, when the X-ray device is mounted on a TSI spectrometer. It was concluded that the X-ray neutralizer could be usefully employed, as a standalone device, in combination with Grimm Electrostatic Classifiers.展开更多
Today reliability is one of the serious requirements of electronic systems. The numbers of system failures, repair cost, guarantee, etc. are estimated by reliability estimation. In this paper reliability of a switchin...Today reliability is one of the serious requirements of electronic systems. The numbers of system failures, repair cost, guarantee, etc. are estimated by reliability estimation. In this paper reliability of a switching power supply, which is used for personal computers, is evaluated. It will show that the most of failure rates depends on power circuit because of more stresses and dissipations. Derating effect of devices on the failure rate is discussed. A prototype power supply＇s waveforms are used for stress detection and calculation of dissipations.展开更多
文摘Scanning Mobility Particle Sizer (SMPS) spectrometers are subject to several restrictions when a radioactive source is employed to bring the aerosol to a steady-state charge distribution. An alternative solution, commercially available, is represented by the soft X-ray neutralizer. The present study investigates the outcome of a combination of a Grimm SMPS, which employs a 241Am radioactive source, with the soft X-ray advanced aerosol neutralizer (TSI model 3087). To date, the latter device has been interfaced only with TSI’s Electrostatic Classifiers. Particle size distribution of sodium chloride aerosol was measured with both neutralizers and it was found that the particle number concentration agreed to be within 9% for the 10 - 700 nm range. This difference mainly corresponds to the bias reported by TSI, when the X-ray device is mounted on a TSI spectrometer. It was concluded that the X-ray neutralizer could be usefully employed, as a standalone device, in combination with Grimm Electrostatic Classifiers.
文摘Today reliability is one of the serious requirements of electronic systems. The numbers of system failures, repair cost, guarantee, etc. are estimated by reliability estimation. In this paper reliability of a switching power supply, which is used for personal computers, is evaluated. It will show that the most of failure rates depends on power circuit because of more stresses and dissipations. Derating effect of devices on the failure rate is discussed. A prototype power supply＇s waveforms are used for stress detection and calculation of dissipations.
