Data Reduction System Research Articles

Density fluctuations in liquid argon: Coherent dynamic structure factor along the 120-K isotherm obtained by neutron scattering.

Coherent dynamic structure factors S(k,\ensuremath{\omega}) obtained by means of thermal neutron inelastic scattering are presented. The experiments were performed on liquid $^{36}\mathrm{Ar}$ at four densities along the 120-K isotherm covering a range of wave numbers k from 4.2 to 39.0 ${\mathrm{nm}}^{\mathrm{\ensuremath{-}}1}$. The neutron time-of-flight spectra are corrected for all known experimental effects with an improved data-reduction system. Special attention is paid to corrections for multiple scattering, duty-cycle overlap, and instrumental resolution. The importance of various correction steps is shown. The reliability of the corrected data is assessed by means of two independent consistency checks, viz., the detailed-balance condition and the first frequency moment of S(k,\ensuremath{\omega}). The S(k,\ensuremath{\omega}) data are presented both as a function of k at fixed \ensuremath{\omega} and as a function of \ensuremath{\omega} at fixed k. The peak height and full width at half maximum of S(k,\ensuremath{\omega}) at fixed k are shown for all densities together with the small-k (hydrodynamic) and large-k (free-gas) asymptotes. The frequency moments of S(k,\ensuremath{\omega}), evaluated up to the fourth moment, are consistent with results from computer simulations and from theoretical calculations. The longitudinal current correlation function ${C}_{l}$(k,\ensuremath{\omega}), derived from the experimental S(k,\ensuremath{\omega}), is examined and both its peak position (yielding the dispersion curve for longitudinal current fluctuations) and its peak height (a measure of the lifetime of the fluctuations) are discussed.

Interactive vaporization and combustion of binary droplet systems

The interactive vaporization and combustion of two horizontally-aligned droplets were experimentally studied using an automated data acquisition and reduction system. Factors investigated include the droplet spacing and size, ambient oxygen concentration, fuel type, droplets of dissimilar fuels, intensity of buoyancy, and pure vaporization. Results show that much of the burning results can be interpreted on the basis of the flame size and oxygen competition, that the existing theory over-predicts the intensity and persistency of interaction, that the gasification rate correction factor depends on the initial as well as the aerothermochemical parameters of the system in addition to the scaled instantaneous droplet separation distance, which is the only (geometrical) parameter present in the theory, that interactive buoyant convection can substantially augment the droplet gasification rate to exceed the isolated value, and that mass exchange between droplets of different volatilities can be quite significant. It is further suggested that interactive effects can be considered to be shorrranged for the droplet gasification rate but long-ranged for the mergedness of the flame.

PADRE: A Computerized Data Reduction System for Cascade Impactor Measurements

An interactive computer resource for analyzing, evaluating, and archiving particle size distributions as determined by cascade impactors for environmental measurement is decribed. The Particle Data Reduction (PADRE) computer program assists users in obtaining high quality size-mass distribution data for archival in the Fine Particle Emissions Information System (FPEIS). PADRE users interactively store, edit, reduce, and analyze observed impactor data from anywhere in the continential United States. Extensive data quality checks and computer- prompted, user-directed program operations assist users in obtaining meaningful information within minutes of entering impactor data. Design goals, program operation, sample sessions and plans for future system development are discussed.

Evaluation of the Abbott TDx for the stat measurement of phenobarbital, phenytoin, carbamazepine, and theophylline.

The Abbott TDx is a fully automated method for drug-level monitoring. The system consists of a competitive fluorescence polarization immunoassay performed by a microprocessor-controlled fluorometer with integral pipetting and data reduction systems. We evaluated the method for the stat measurement of phenobarbital (PHENO), phenytoin (PTN), carbamazepine (CARB), and theophylline (THEO). The threshold of detection is PHENO, 0.8 mg/L; PTN, 0.8 mg/L; CARB, 0.1 mg/L; and THEO, 0.4 mg/L. Between-run precision in the therapeutic range expressed as coefficient of variation is between 3.3% and 9.1% for all four drugs. Recovery of each drug from a variety of matrices was essentially 100%, with no significant interference by elevated levels of bilirubin, triglycerides, or hemoglobin. The TDx methods were correlated to established methods for 100 patient specimens: PHENO: Y(TDx) = 0.95 (GLC) + 1.4 mg/L R = 0.98 PTN: Y(TDx) = 0.91 (GLC) + 1.1 mg/L R = 0.99 CARB: Y(TDx) = 0.91 (EMIT) + 0.4 mg/L R = 0.98 THEO: Y(TDx) = 0.93 (HPLC) + 0.5 mg/L R = 0.99 The calibration stability is no shorter than one week (PTN) and as long as five weeks (CARB). The analytic system is an accurate, precise, and highly stable method for the stat measurement of these four drugs.

A technique to determine lift and drag polars in flight

Abstract : Performance trials of the European combat aircraft TORNADO have concentrated on the systematic measurement of lift and drag polars. Such polars have been successfully measured by means of well-adapted test instrumentation, a data reduction system, and a high calibration standard of the aircraft and engines. The use of a certain combination of steady-state and dynamic test maneuvers has resulted in a drastic reduction in the amount of flight time required to obtain sufficient data for the determination of the zero lift drag, induced drag characteristics and drag increments due to aircraft configuration changes. Flight test results are presented which demonstrate the advantage of the test technique used and the high data quality achieved.

A novel system for atmospheric corrosion experiments

Atmospheric corrosion testing in the laboratory requires the capability of achieving stable and realistic exposure conditions, exposure of multiple samples, wide ranges of concentrations of corrosive gases, and exposure times varying from seconds to weeks. This paper describes a system that meets these requirements. It utilizes polymer permeation as a source of corrosive gases, a hook-and-loop fastening system for sample manipulation, a multiport chamber for sample exposure, and a dedicated desktop computer system for sample monitoring and data reduction. System characteristics include the generation of corrosive trace gases from a low level of 8 ± 1 ppb to a high level of 5 ± 0.1 ppm, exposure times of less than 1 min to 5 weeks, and simultaneous exposure of 60–90 samples.

Radio Observations of the Supernova Remnant CTB109 (G109.2–1.0)

The supernova remnant G109.2–1.0 was discovered at λ49cm by Hughes, Harten and van den Bergh (1981) during a survey of part of the Galactic plane. The northern part of it had been detected previously as the non-thermal radio source CTB109 by Wilson and Bolton (1960), and by Raghava Roa et al (1965), but the extended low brightness of the source and its close proximity to the very strong source Cas A, from which it is separated by ∼5′, excluded it from any further detailed study. It was discovered independently at X-ray wavelengths by Gregory and Fahlman (1980). Recently, the original WSRT radio observations have been found to be in error as a result of applying the CLEAN procedure to an extended source, and since the object appears to contain an X-ray pulsar (Fahlman and Gregory, 1981), it was decided to carry out a more detailed and extensive mapping of the remmant using different antenna arrays and frequencies. This paper describes the results obtained at λ49cm and λ21cm using the Westerbork Synthesis Radio Telescope (WSRT), at λ21cm using the aperture synthesis array at the Dominion Radio Astrophysical Observatory (DRAO) and at λ4.6cm using the 46m telescope of the Algonquin Radio Observatory (ARO). Thus, data has been obtained from three completely independent telescopes, using completely independent data reduction systems. Of importance is the fact that not only have wavelengths been chosen such that the larger dimensions of the array give a reasonable angular resolution of ≤1′, but also that the smallest spacing enables the larger angular dimensions of the remnant to be observed. This paper presents some of the results and a brief interpretation.

Low-resolution neutron diffractometry with a position-sensitive multidetector

A data reduction system for neutron crystallography using a two-dimensional planar multidetector is described. The method is based on an a priori calculation of the intensity distribution for each reflection for any crystal orientation. The orientation matrix of the crystal has to be known. From the calculated intensity distribution a mask is derived for each reflection. The detection elements of the detector which are inside the mask are summed to determine the intensity of that reflection and the cells outside are used to determine the background. The size of the mask is adapted to the relative height of the measured intensity of the reflector compared to the background. The theoretical intensity distribution for each reflection is calculated in reciprocal space from the primary-beam divergence and wavelength spread and the crystal mosaic spread, on the basis of the kinematic theory of diffraction. The derivation of the necessary equations, i.e. the determination of the resolution function of the instrument, is presented. Some typical results of data collection are also presented. The advantages of this data collection method are the safe determination of weak reflections, the easy discrimination of reflections which nearly overlap, the determination of crystal mosaic spread, and the discrimination of inelastic scattering in the proximity of intense reflections.

The design, development, and implementation of a microprocessor-based ECG analysis system

This paper describes the research effort to design, develop, and implement a microprocessor-based ECG data acquisition, reduction, and analysis system for operation in real-time. This unit can be attached to three-channel ECG carts and provide an immediate on-site analysis. The basic design and development efforts include (1) the data acquisition, reduction, and matrix assembly, (2) ECG arrhythmia, P-wave, and axis analysis, (3) ECG contour analysis, and (4) a real-time three-channel data acquisition unit. Decision tables are used in the analysis. The implementation of these projects into a small microprocessor-based unit coupled to a three-channel recorder is now in progress. This system, coupled with a small printer, will provide immediate on-site ECG analysis for most cardiovascular dysfunctions.

Coal Liquefaction Product Gas Analysis with an Automated Gas Chromatograph

Application of an automated TCD/FID Carle gas chromatograph for on-stream analysis of coal liquefaction product gases generated in a continuous SRC-II pilot plant was demonstrated. Used in tandem with a computerized data reduction system, the GC measured gas composition, computed molecular weight, and density. Gases analyzed included H2, CO, CO2, O2, N2, H2S, and all C1-C6 hydrocarbons. The method had excellent accuracy, reproducibility, and long-term stability. It was a quick, reliable, convenient, and low-cost analytical technique. Based on the GC analyses, hydrogen consumption and gaseous product yields were determined for SRC-II liquefaction experiments

The TYCHO system for computer analysis of two-dimensional gel electrophoresis patterns.

We describe here a computer system for the analysis of high-resolution two-dimensional gel-electrophoresis patterns, with some initial applications. The system (called TYCHO) comprises programs for image acquisition, background subtraction and smoothing, spot detection, gaussian spot modeling, and pattern matching and comparison. It is based on a conventional minicomputer, but makes extensive use of a high-speed array processor in the image-processing and -modeling steps. Used in concert with the ISO-DALT two-dimensional electrophoresis system (Anal. Biochem. 85:331-354, 1978), TYCHO allows quantitative measurement of hundreds of proteins in complex biological samples, and constitutes the initial data-reduction system required for work towards a Human Protein Index.

Deformation and Fracture Testing for Hot Working Processes

A hot workability testing apparatus has been designed and constructed for determining flow stress and fracture of materials at elevated temperatures. The system is composed of four major elements: a closed-loop servo-controlled hydraulic testing machine with programmable and custom-made control components; a high temperature tooling and radiant heating furnace for isothermal test conditions; a test specimen transfer device for ease of testing and rapid quenching; and a computerized data acquisition and reduction system. Isothermal, homogeneous compression tests are performed for flow stress determination, while upset and bend tests are used for workability evaluation. Test temperatures to 1200°C may be achieved, along with constant strain rates up to 20s’1 for both compression and bend tests. Specimens can be quenched within 0.5-0.75s to permit the study of the microstructures developed during hot deformation. In both compression and bending, interrupted deformation schedules can be programmed. Change of rate tests to measure strain rate sensitivites are also possible. Capabilities of the system are illustrated by results obtained for the multiphase alloy MP35N (35% Co, 35% Ni, 20%o Cr, and 10% Mo).

The “iron screen”: Modification of standard laboratory practice with data analysis

Multivariate analysis was applied to iron deficiency anemia to generate an efficient sequence of diagnostic laboratory tests. A three step diagnostic system—serum ferritin level and mean corpuscular volume as a screen in all patients, followed by serum iron level and total iron binding capacity in some patients, and by erythrocyte sedimentation rate in a few patients—was constructed using a previously validated data reduction system. When compared to bone marrow iron stores, this system was found to have 96 per cent accuracy. In one year of clinical trial the “iron scree” classified 396 of 416 patients in a hospital setting. This sequential strategy shows how clinical laboratory data can be utilized to render diagnoses of defined probability.

A data reduction system for the electrical aerosol analyzer and comparisons with a diffusion battery for submicrometer size measurements

A data reduction system for the electrical aerosol analyzer and comparisons with a diffusion battery for submicrometer size measurements

An automatic data acquisition system for simultaneous operation of two Mettler thermoanalyzers

An automatic data acquisition system was developed for two Mettler Vacuum Recording Thermoanalyzers, Model TA-I, using a Hewlett-Packard 9825S calculator. The interface with the thermoanalyzers is unique in the way that it is independent of and has a wider dynamic range than the six-channel strip chart recorder supplied with the instrument. The data acquisition system permits data from two TA-Is simultaneously in operation to be collected and stored in a magnetic tape cartridge. To facilitate rapid analysis of the acquired data, five computer programs were also developed for use with a Hewlett-Packard 9872A plotter. This data reduction system would (1) plot the thermograms (DTA, TG, DTG) including the % weight changes as a function of temperature or time, (2) label the thermograms, (3) record the experimental conditions, (4) correct the thermogravimetric data for effect due to buoyancy, if desired, (5) locate and mark the peak minima and maxima on DTA and DTG curves, and (6) tabulate the % weight change between two temperatures or time.

Data reduction systems for HEP experiments

Fast logic triggers are described which are capable of rejecting unwanted events during HEP experiments. Classes of track patterns are defined by entries in read/write memories and can be readily changed. Readout information from multiwire chambers addresses these memories and their outputs are processed by fast combinational logic to produce trigger decisions. In the circumstances where speed of decision making is not the prime consideration a much cheaper serial-parallel decision sequence may be implemented which, although slower in operation, can offer a very good definition of the tracks generated in a given data intake. Triggers of both categories are currently being used in experiments mounted at DESY and at CERN.

Technical Note

An experimental study was undertaken to measure the instantaneous lift and propulsive forces generated by a rigid, sinusoidally flapping wing at Reynolds numbers ranging from 72 000 to 120 000. The wing was flapped about a fulcrum at the root at frequencies of 2.55 Hz and 3.30 Hz. Instrumentation and a data reduction system were developed to provide quick and reliable assessment of the effects of changes in flapping amplitude, flapping frequency, flapping plane angle, wing incidence, and windspeed. In this way it was attempted to model, however crudely, the forward flapping flight of birds.The instantaneous values of lift coefficient and thrust coefficient were plotted against position in the cycle while the average CL and CT were plotted against advance ratio (ratio of the windspeed to the maximum tip speed velocity). The experimental results were compared to the theories of Walker(e) and Hoist ' Kuchemann(4) both modified to correspond more closely to the experimental conditions.

Wind and Wave Measurements Taken from a Tower in Lake Michigan

In July 1977 the Great Lakes Environmental Research Laboratory installed a lightweight, solar powered research tower in Lake Michigan. The tower, located 2 km offshore from Muskegon, Michigan, in 16 m of water, provided a stable platform for two levels of anemometers and air temperature sensors, a surface water temperature sensor, and an array of four wave staffs to measure meteorological and directional wave variables. Solar power was successfully used to provide power for tower instrumentation. The measurements, while short-lived due to a guy wire failure in October 1977, comprise over 1300 well-documented hourly wind and wave data for further detailed studies. This report presents a detailed description of the instrumentation, data collection, and data reduction systems. The results show that the triangular array of wave staffs provides reasonable wave direction information, although nearshore waves appear to have a larger onshore component of momentum than would be indicated by prevailing winds. Further detailed studies of wind and wave processes are in progress.

A General Purpose Microprocessor Based Data Acquisition and Reduction System

ABSTRACT The system presented allows intelligent data acquisition by an easily programmed algorithm on low cost microprocessor development units. Peaks of a signal are detected and selectively recorded under software control. A substantial data reduction can be achieved with negligible loss of information. The system is applied to the acquisition of densitometric data on ion sensitive emulsions obtained by spark source mass spectrometry.

Hybrid system for fast data reduction of long-term blood-pressure recordings

Fast analysis of long-term intra-arterial blood-pressure recordings can be approached in various ways. We describe a low cost system, consisting of a hybrid preprocessor and a minicomputer, which can either perform fast data reduction, producing simple statistical information to aid patient management, or be used as the basis of a more comprehensive signal processing facility for research purposes. The preprocessor saves computer time by detecting and measuring the systolic and diastolic points, thereby allowing recordings to be processed 25 times faster than they were recorded. Attention has been given to the special problems of calibration and artefact rejection. Data conversion accuracy was found to be within 2% on a typical recording. The system can run automatically if required to ease the task of routine blood-pressure tape processing.