62,669 research outputs found
An improved thick-film piezoelectric material by powder blending and enhanced processing parameters
No full textThis paper details improvements of the d33 coefficient for thick-film lead zirconate titanate (PZT) layers. In particular, the effect of blending ball and attritor milled powders has been investigated. Mathematical modeling of the film structure has produced initial experimental values for powder combination percentages. A range of paste formulations between 8:1 and 2:1 ball to attritor milled PZT powders by weight have been mixed into a screen-printable paste. Each paste contains 10% by weight of lead borosilicate glass and an appropriate quantity of solvent to formulate a screen printable thixotropic paste. A d33 of 63.5 pC/N was obtained with a combination of 4:1 ball milled to attritor milled powder by weight. The improved paste combines the high d33 values of ball and the consistency of attritor milled powder. The measured d33 coefficient was further improved to 131 pC/N by increasing the furnace firing pro-file to 100
Improved sub-threshold Slope in RF vertical MOSFETS using a frame gate architecture
No full textWe report a CMOS-compatible vertical MOSFET, which incorporates a frame gate architecture suitable for application in RF circuits. Fabricated surround gate vertical MOSFETs with the frame gate architecture show no degradation of short channel effects when the channel length is scaled, while control devices show significantly degraded sub-threshold slope and DIBL. The frame gate vertical MOSFETs show near ideal sub-threshold slopes of 70-80mV/decade and DIBL of 30-35mV/V in a 100 nm gate length nMOS device. In contrast, the control vertical MOSFETs without the frame gate exhibit sub-threshold slopes of 110 to 140 mV/decade and DIBL of 100 to 280 mV/V. This improved sub-threshold slope is explained by the elimination of etch damage during gate etch
Hot DAVs: a probable new class of pulsating white dwarf stars
No full textWe have discovered a pulsating DA white dwarf at the lower end of the temperature range 45 000–30 000 K where a few helium atmosphere white dwarfs are known. There are now three such pulsators known, suggesting that a new class of theoretically predicted pulsating white dwarf stars exists. We name them the hot DAV stars. From high-speed photometric observations with the ULTRACAM photometer on the 4.2-m William Herschel Telescope, we show that the hydrogen atmosphere white dwarf star WD1017−138 pulsates in at least one mode with a frequency of 1.62 mHz (a period of 624 s). The amplitude of that mode was near 1 mmag at a 10σ confidence level on one night of observation and an 8.4σ confidence level on a second night. The combined data have a confidence level of 11.8σ. This supports the two other detections of hot DAV stars previously reported. From three Very Large Telescope Ultraviolet and Visual Echelle Spectrograph spectra we confirm also that WD1017−138 is a hydrogen atmosphere white dwarf with no trace of helium or metals with Teff = 32 600 K, log g = 7.8 (cgs) and M = 0.55 M⊙. The existence of pulsations in these DA white dwarfs at the cool edge of the 45 000–30 000 K temperature range supports the thin hydrogen layer model for the deficit of helium atmosphere white dwarfs in this range. DA white dwarfs with thick hydrogen layers do not have the superadiabatic, chemically inhomogeneous (μ-gradient) zone that drives pulsation in this temperature range. The potential for higher amplitude hot DAV stars exists; their discovery would open the possibility of a direct test of the explanation for the deficit of helium atmosphere white dwarfs at these temperatures by asteroseismic probing of the atmospheric layers of the hot DAV stars. A search for pulsation in a further 22 candidates with ULTRACAM on the European Southern Observatory New Technology Telescope gave null results for pulsation at precisions in the range 0.5–3 mmag, suggesting that the pulsation amplitudes in such stars are relatively low, hence near the detection limit with the ground-based telescopes used in the survey
Letter from W. T. Johnson to W. D. White
No full textLetter from W. T. Johnson to W. D. White, concerning 3rd place winner of H. O. Sargent award
Michigan State Dental Association.
No full textEditors: Aug. 1859-July 1865, J. D. White, J. H. McQuillen, G. J. Ziegler.--Aug. 1865-Dec. 1871, J. H. McQuillen, G. J. Ziegler.--Jan. 1872-May 1891, J. W. White.--July 1891-Apr. 1930, E. C. Kirk (with L. P. Anthony, Dec. 1917-Apr. 1930).--May 1930-Dec. 1936, L. P. Anthony.Vols. 1-13 are called "new series."Merged in Jan. 1937 with: Journal of the American Dental Association, ISSN 1048-6364, to form: Journal of the American Dental Association and dental cosmos, ISSN 0375-8451
Michigan State Dental Association.
No full textEditors: Aug. 1859-July 1865, J. D. White, J. H. McQuillen, G. J. Ziegler.--Aug. 1865-Dec. 1871, J. H. McQuillen, G. J. Ziegler.--Jan. 1872-May 1891, J. W. White.--July 1891-Apr. 1930, E. C. Kirk (with L. P. Anthony, Dec. 1917-Apr. 1930).--May 1930-Dec. 1936, L. P. Anthony.Vols. 1-13 are called "new series."Merged in Jan. 1937 with: Journal of the American Dental Association, ISSN 1048-6364, to form: Journal of the American Dental Association and dental cosmos, ISSN 0375-8451
Michigan State Dental Society.
No full textEditors: Aug. 1859-July 1865, J. D. White, J. H. McQuillen, G. J. Ziegler.--Aug. 1865-Dec. 1871, J. H. McQuillen, G. J. Ziegler.--Jan. 1872-May 1891, J. W. White.--July 1891-Apr. 1930, E. C. Kirk (with L. P. Anthony, Dec. 1917-Apr. 1930).--May 1930-Dec. 1936, L. P. Anthony.Vols. 1-13 are called "new series."Merged in Jan. 1937 with: Journal of the American Dental Association, ISSN 1048-6364, to form: Journal of the American Dental Association and dental cosmos, ISSN 0375-8451
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Letter From W. R. O\u27Neal to Eartha White
No full textCorrespondence: Letter from W. R. O\u27Neal, Curtis and O\u27Neal Co. Insurance & Loans, Orlando, Florida, to Miss E. M. M. White, Jacksonville, Florida, regarding Eartha White\u27s inquiry into property owned by Mrs. E. W. Jackson. Handwritten notes on envelope. Date: October 21, 1929
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