Two systems for the measurement and standardization of peak pulse voltage have recently been developed in the Radio Standards Engineering Division of the National Bureau of Standards. Des igned for use with pulses having durations as short as 10 nanoseconds, the s ystems represent the initi al e ffort by NBS for establishment of standards in this fi eld and it is expected that they will serve a...

PURPOSE To examine the effects of interleukin (IL)-1beta on the resistance and permeability of the tight junctions of cultured retinal pigment epithelial cells. METHODS A human RPE cell line (ARPE-19) cultured on microporous filter-supports was used. IL-1beta and monoclonal anti-IL-1beta antibody-treated IL-1beta (mAbIL-1beta) were added to the standard culture medium. Transepithelial resista...

introduction: application of light transmitting posts to restore greatly damaged endodontically treated teeth has been increased. it is suspected that light intensity decreases as it passes throughout different materials. this can reduce the degree of conversion required for adequate bond strength throughout the length of these posts. the objective of this study was to evaluate the amount of li...

FrOR direct measurement of small amounts of power, or for measurement of power over a wide range of frequencies, dynamometer wattmeters are unsatisfactory, and vacuum tube wattmeters are often resorted to. Hitherto vacuum tube wattmeters have depended for their operation on the use of tubes having a square-law characteristic, connected in a push-pull circuit so as to avoid indications caused by...

Ever since the picturesque description of "animal electricity" by Galvani in the latter part of the eighteenth century, it has been tacitly assumed that electrical phenomena could be found associated with many biological processes. In fact, in recent years, a score or more of distinguished investigators have been studying the alternating current characteristics of the nervous system. These stud...

In power supply networks, the quality of the voltage is becoming more and more of a determining factor. Non-linear loads such as diode or thyristor converters contribute to the degradation of the supply voltage quality. Non-sinusoidal currents of the non-linear loads result in the distortion of the supply voltage wave form at the point of common coupling due to the finite supply impedance. To i...

THE thesis of this article has both a negative and a positive aspect. The negative one holds that psychophysical measurement is not of a character closely analogous to either fundamental or derived physical measurement. Whatever loudness may be, I endeavor to establish that it probably is not a measure much like mass or energy or density. In brief, the reason is that psychophysical measures do ...

Introduction Chloride is the most important anion associated with sodium in the extra cellular fluid with a normal concentration ranging from 96 to 106 (1). The complete interpretation of acid-base disorders is impossible without knowing the serum chloride concentration (2). In the process of quantitative acid-base analysis, plasma pH is determined by three independent variables: pCO2, total co...

Environmental impact assessment has become an important issue for deep-sea resource mining. The International Seabed Authority recently developed recommendations guidelines on environmental of mining effects. Several research and development groups have been organized to develop methods the seafloor sub-seafloor under “Zipangu in Ocean program,” a part Cross-ministerial Strategic Innovation Pro...