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An ergodic source which is not a function of any finite Markov process
Information theory; Markov process; probability theory; ring theory; stochastic process
The problem of deciding when a stationary process is a function of a finite Markov process has been considered by several authors, leading to an elegant necessary and sufficient condition. Taking a different approach, this note uses elementary ring...
Journal of Research of NIST and Predecessor Publications

Radiochrometer
National Bureau of Standards (NBS) physicist William W. Coblentz built this radiochrometer in 1906 in an attempt to improve on earlier designs made in Germany. He succeeded in making a better instrument, but was not satisfied with it and went back...
NIST Museum Artifacts

Tea laser induced multiphoton dissociation of ethylene in a collisional regime: Model and experiment
Infrared; kinetics; lasers; model; multiphoton; photochemistry.
The focused beam of a pulsed CO2 TEA laser was used to photodissociate ethylene gas at total pressures of 100-300 torr. The laser pulse induces molecular hydrogen elimination to yield primarily C2H2 and H2 in an large excess of helium to eliminate...
Journal of Research of NIST and Predecessor Publications

The characterization of linear polyethylene SRM 1475. II. Determination of total methyl content by infrared spectrophotometry
Infrared; linear polyethylene; methyl; methylene; number average molecular weight; spectra; spectrophotometry
An ASTM method was used to determine the methyl content of linear polyethylene SRM 1475 by measuring the absorbance at 1378 cm-1 (7.25 nm) of methyl groups on compensated infrared spectra. The methyl content of this polymer was found to be 0.15...
Journal of Research of NIST and Predecessor Publications

The infrared spectra of matrix isolated uranium oxide species
Infrared spectra; mass spectrophotometry; matrix isolated; oxides of uranium
The infrared spectra of matrix isolated products of the interaction of uranium and oxygen have been investigated at high temperatures. By use of collateral available data on the various uranium oxide species, plus employment of oxygen 16 and 18...
Journal of Research of NIST and Predecessor Publications

The dependence of inspection-system performance on levels of penalties and inspection resources
Inspection; mathematical model; regulation; strategy; theory of games
This paper presents three simple mathematical models, all of game-theoretic type, dealing with an inspector-inspectee relationship. The inspectee always tries to maximize his net gain, which is the amount he obtains by ""cheating"" less the amount...
Journal of Research of NIST and Predecessor Publications

A Game-Theoretic Model of Inspection-Resource Allocation
inspection; mathematical model; regulation; theory of games.
This paper presents a generalization of a game-theoretic model, first described in an earlier paper, of the relationship between an inspectee who may decide to "cheat" or not, and an inspector whose task it is to minimize the expected gain that the...
Journal of Research of NIST and Predecessor Publications

Optimal periodic inspection programs for randomly failing equipment
Inspection program; loss function; randomly failing equipment
There have been many analyses made of models for equipment inspection, i.e., where a system may suffer a breakdown, but such an event is only discovered by an inspection. Most analyses assume that the tIme to failure follows a negative exponential...
Journal of Research of NIST and Predecessor Publications

Realistic evaluation of the precision and accuracy of instrument calibration systems
instrument calibration system, accuracy, measurement, systematic error, precision
Calibration of instruments and standards is a refined form of measurement. Measurement of some property of a thing is an operation that yields as an end result a number that indicates how much of the property the thing has. Measurement is...
Journal of Research of NIST and Predecessor Publications

Polycapillary optics for materials science studies: Instrumental effects and their correction
instrumental effects; parallel beam geometry; polycapillary optics; residual stress analysis; texture analysis; x-ray diffraction; x-ray optics
The instrumental effects related to the use of a polycapillary x-ray lens as primary beam collimator are here studied and the features observed in the measurements modelled via Monte-Carlo ray-tracing. Comparison with existing procedures is...
Journal of Research of NIST and Predecessor Publications

Troubleshooting Liquid Chromatographic Instrumentation and Methods
instrumentation; method, development; problem, solving; system, performance; troubleshooting.
(tutorial)
Journal of Research of NIST and Predecessor Publications

Some infinite sums involving zeros of Jo(x)
Integer; infinite sums; limiting form
The limiting form for small [symbol]values of the sums [equations] and [equation] where r is an integer and beta n is the nth zero of the Bessel function Jo(x), have been obtained. Related functions which arise in these problems are also considered.
Journal of Research of NIST and Predecessor Publications

A variant of the two-dimensional Riemann integral
Integrable functions; Rieman integral
For a va riant of the two-dimensional Riemann in egral suggested by S. Marcus, it is shown that the only integrable functions which are continuous (or merely continuous separately in one of the variables) are the constant functions. The integrable...
Journal of Research of NIST and Predecessor Publications

Some computational problems involving integral matrices
Integral matrices; projective geometries; SEAC and SWAC
In this mainly expository article dealing particularly with recent problems, a computational problem of G. Pall related to finite projective geometries is discussed in greater detail. Numerical results obtained on SEAC and SWAC are discussed.
Journal of Research of NIST and Predecessor Publications

Relations between summation methods and integral transformations
Integral transformation; Lototsky method; summation methods
Relations between the Lototsky method of summation and those of Borel, Euler, and Knopp are obtained by associating an integral transformation with the series transformation.
Journal of Research of NIST and Predecessor Publications

Mass absorption coefficient of tungsten and tantalum, 1450 eV to 2350 eV: Experiment, theory, and application
integrated circuit interconnect; M3 edge; M4 edge; M5 edge; mass absorption; microspectroscopy; tantalum; transmission; tungsten
The mass absorption coefficients of tungsten and tantalum were measured with soft x-ray photons from 1450 eV to 2350 eV using an undulator source. This region includes the M3, M4, and M5 absorption edges. X-ray absorption fine structure was...
Journal of Research of NIST and Predecessor Publications

Measurement of Scattering and Absorption Cross Sections of Microspheres for Wavelengths between 240 nm and 800 nm
integrating sphere detector; Lorenz-Mie; microspheres; scattering
A commercial spectrometer with a 150 mm integrating sphere (IS) detector was used to estimate the scattering and absorption cross sections of monodisperse polystyrene microspheres suspended in water. Absorbance measurements were performed with the...
Journal of Research of NIST and Predecessor Publications

A numerical solution of the integral equation describing a photometric integrating sphere
Integrating sphere; photometry
A photometric integrating sphere containing a single disk-shaped baffle and a point source with an arbitrary angular intensity distribution is described by an integral equation. Numerical solutions of this equation are presented for several...
Journal of Research of NIST and Predecessor Publications

IMPROVEMENTS IN THE APPLICATION OF THE NUMERICAL METHOD OF CHARACTERISTICS TO PREDICT ATTENUATION IN UNSTEADY PARTIALLY FILLED PIPE FLOW
integration; interpolation; method of characteristics; rectangular grid (R.G.).
The use of linear interpolation and simplified iteration procedures are shown to introduce inaccuracies to the rectangular grid method of characteristics, particularly when applied to subcritical flows. Comparisons of experimental and computational...
Journal of Research of NIST and Predecessor Publications

Temperature classification of the spectra of dysprosium (Dy I, Dy II)
Intensity estimates, Dy spectra; dysprosium spectra, temperature classification; temperature classification, Dy I and Dy II; spectra, Dy I and Dy II
The Temperature Classifications are listed for 4584 lines of Dy I and Dy II, as taken from an unpublished manuscript of the late A. S. King. In recording his observations, King used a wavelength list compiled mostly from the early literature. A...
Journal of Research of NIST and Predecessor Publications

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