bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aerosol Generation from the Sanding, Cutting, and Breaking of Floor Tiles
Authors: Lundgren Dale A. , Vanderpool R. W. , Liu Benjamin Y. H. 
Published: December 2004

AbstractVarious types of floor tile were tested in a controlled and isolated environment to determine quantitatively the wear rate and size characteristics of material generated from floor tile during operations of sanding, cutting, and breaking. Size characteristics were determined for the aerosolized fractions as well as the settled material worn from the tile surface. In addition to the vinyl composition tile, tests were also conducted with floor tile containing various amounts of glass fiber and sodium phosphate fibers. The tests were conducted in a specially designed glove box which allowed complete sampling and fractionization of the generated aerosol. Due to good measurement repeatability, aerosol generation differences from the various flooring types were determinable.A Frick‐Taber accelerated wear machine was employed to establish comparative wear rates of the different flooring materials. Test results were repeatable and measured relative wear rates correlate well with published measurements. Results indicate that the presence of up to 13% glass fibers or phosphate fibers in the tile does not improve the tile's wear characteristics or significantly alter the size distribution of the generated material. Although asbestos‐containing floor tile was not tested in this study, results from the simulant fiber tile tests may enable prediction of the behavior of vinyl‐asbestos tile under the influence of similar wear mechanisms.
Drop Sizing by Laser Light Scattring Exploiting Intensity Angular Oscillation in the mie regime
Authors: Ragucci Raffaele , Cavaliere Antonio , Massoli Patrizio 
Published: December 2004

AbstractThe intensity angular pattern of the light scattered by a drop at a scattering angle of ca. 90° is related to the size of the scattering drop. A simple relationship between the number of fringes per degree and the size is presented. The possibility of measuring the drop size through visualization of the fringe pattern is demonstrated.
Pulse Holography and Phase‐Doppler Technique. A comparison when applied to swirl pressure‐jet atomizers
Authors: Umhauer Heinz , Löffler‐Mang Martin , Neumann Peter , Leuckel Wolfgang 
Published: December 2004

AbstractPulse holography and the phase‐Doppler technique are two of the very few methods with which the size and velocity of individual particles within a two‐phase flow may be simultaneously measured. This enables the two‐dimensional frequency distributions of particle size and velocity to be compiled and allows the existence of mutual correlations to be verified.The application of both methods to investigations into water droplet collections within the hollow spray cone of a swirl pressure‐jet atomizer is described. When comparing the results of measurements obtained by the two methods under identical conditions, one fundamental difference must be taken into account: whereas pulse holography delivers space‐averaged concentration‐dependent frequency distributions, those derived from the phase‐Doppler technique are time‐averaged fluxdependent. The methods hence deliver different, but equivalent, results. Since the possibility of conversion exists, both representations are always available. As far as the particle size distributions are concerned, the results obtained from the two methods confirm the expected differences, whilst verifying the compliance of the interconverted size distribution data. Regarding the velocity distributions, however, some unexplained discrepancies still remain.
Estimation of the Effective Measuring Volume of Single‐Fibre Reflection Probes for solid volume concentration measurements
Authors: Rensner Detlef , Werther Joachim 
Published: December 2004

AbstractThe working principle of the single‐fibre reflection (SFR) probe is that light emitted by a laser diode is guided into the measuring volume by the same fibre which receives the proportion of light reflected by the particles in the vicinity of the probe tip and transmits it back to a photosensitive element. In contrast to other configurations of fibre optical probes, the SFR probe is characterized by an unambiguous calibration graph over the entire range of solid volume concentration values. SFR probes have been successfully applied to different kinds of multiphase flow systems, e.g. fluidized beds, pneumatic conveying lines, elutriators and thickeners.A particular question for the interpretation of measurements has always been the effective size of the measuring volume, which is mainly determined by the solid volume concentration. In this paper a simplified mathematical model of the signal generation by backscattering of the emitted light at the particle surfaces is given. The theory takes into account the average optical properties of the solids and their particle size distributions.The particle properties are determined on the basis of this model, which finally delivers the shape, size and depth of the effective measuring volume. For particle sizes between 30 and 120 μm the depth of the measuring volume of a 600‐μm fibre probe is between 0.2 mm for solid concentrations near the fixed‐bed state and approximately 4 mm for solid volume concentrations as low as 0.1 vol.‐%.
Particle Sizing by Photon Correlation Spectroscopy. Part IV: Resolution of bimodals and comparison with other particle sizing methods
Authors: Finsy Robert , Deriemaeker Lue , De Jaeger Nicolas , Sneyers Rik , Vanderdeelen Jan , Van der Meeren Paul , Demeyere Hugo , Stone‐Masui Jeanine , Haestier Anne , Clauwaert Julius , De Wispelaere Walter , Gillioen Pascal , Steyfkens Sabine , Geladé Erik 
Published: December 2004

AbstractThe practical performances of single and multi‐angle photon correlation spectroscopy (PCS) for resolving bimodal distributions of industrial poly (methyl methacrylate) samples was investigated in a comparative study by several users affiliated to academic and industrial groups and by two suppliers of commercial equipment. The results for the harmonic intensity averaged diameters obtained by cumulants analysis reported by the different laboratories are in agreement, in addition to the results for the normalized second cumulants. The uncertainty on the latter quantities is large, however. For the bimodal samples with two populations with average diameters in a ratio of about 2.5 : 1, not all users were able to resolve the distribution in its components by single‐angle PCS. Some slight improvement was obtained by multi‐angle PCS. Other indirect techniques (polarization intensity differential scattering, static light scattering data and disc photosedimentometer) appeared to be superior for resolving the bimodal distributions.
Measurement of Aggregate Fractal Dimensions Using Static Light Scattering
Authors: Raper Judy A. , Amal Rose 
Published: December 2004

AbstractAggregates formed from colloidal particles will vary in shape according to the aggregation regime prevalent. Compact structures are formed when the aggregation is slow, whilst loose tenuous structures are formed when rapid (or diffusion limited) aggregation prevails. These structures can be fractal in nature, that is, there is a relationship between porosity and the number of primary particles making up the aggregate, and is described by the fractal dimension, dF. Fractal dimensions of hematite aggregates have been measured experimentally using the static light scattering technique. Fractal dimensions varied with aggregation regimes; for the rapid aggregation regime, dF was found to be 2.8, whilst for conditions in which aggregation was slow (retardation forces prevail), dF's of 2.3 were measured. For conditions which lead to aggregation in which both diffusion and retardation forces play a part, structures with fractal dimensions such that 2.3 < dF < 2.8 were found.The effects of adsorbed fulvic acid, a naturally occuring organic acid, on the kinetics of hematite aggregation and on the resulting structure of hematite aggregates were also investigated. The study of aggregate structure shows that the fractal dimensions of hematite aggregates which are partially coated with fulvic acid molecules are higher than those obtained with no adsorbed fulvic acid. The scattering exponents obtained from static light scattering experiments of these aggregates range from 2.83 ± 0.08 to 3.42 ± 0.1. The scattering exponents of greater than 3 indicate that the scattering is the result of objects that contains pores which are bounded by surfaces with a fractal structure, and can be related only to surface fractal dimension. The high fractal dimensions are due to restructuring within the aggregates, which only occured at low coverage by the organic acid.
Particle Shape Analysis as an example of knowledge extraction by neural nets
Authors: Kohlus Reinhard , Bottlinger Michael 
Published: December 2004

AbstractAn investigation is presented concerning the ability of neural nets to classify particles using contour data. Different nets were trained to classify limestone, quartz and coffee particles by their outer boundaries. The contour lines of the analysed particles were similar and differed only in a complex way. A new method of interpreting the Fourier coefficients is shown, which might lead to a possibility of defining particle shape classes by examples. Information is given concerning the selection and design of the appropriate neural net, e.g. back‐propagation, and self‐organizing maps. In addition, a possibility of interpreting the trained neural nets is demonstrated.
Evaluation of a Particle Sizing Technique Based on Laser Sheets
Authors: Gréhan Gérard , Ren Kuan Fang , Gouesbet Geŕrd , Naqwi Amir , Durst Franz 
Published: December 2004

AbstractThe use of a laser sheet (or elliptical Gaussian beam) in meas‐urement techniques is of growing interset. Some of these techniques take advantage of the wavefront curvature of such beams as in a dual‐crylindrical wave system (DCW). Nevertheless, up to now, the analysis of the properties of the light scattered by spherical particles form the beam has been carried out largely by using geometrical optics or classical Lorenz‐Mie theory. In this paper, the generalized Lorenz‐Mie theory (GLMT) is applied to the analysis of an existing DCW measurement system. Differences between the results predicted by classical approaches and by GLMT are emphasized.
The Pulse Displacement Technique — a single particle counter with a size range larger than 1000: 1
Authors: Hess Cecil F. , Wood Craig P. 
Published: December 2004

AbstractThis paper describes the pulse displacement technique(PDT) to simultaneously measure particle size and velocity in applications characterized by a large size range and high particle concentration. PDT is based on the detection of scattered refraction and reflection pulses which sweep past a detector at different times as a particle traverses a narrow probe volume. Basic analytical relationships are presented which allow the calculation of the spatial and temporal widths and separations of the reflection and refraction pulse as a function of particle diameter and velocity. Two implementations of PDT are discussed using one or two receivers with two laser sheets having the same or different wavelengths. This paper also discusses several methods to measure particle velocity with PDT, discusses the limitations associated with signal broadening in practical systems, and briefly presents experimental results which show that the temporal separation between the refraction and reflection and reflection pulse maxima is independent of collecting lens f‐number from f/3 to f/20 for particle sizes ranging from 250 to 2000 μm.
Morphological shape characterization: Application to oxalate crystals
Authors: Vivier Hervé , Marcant Bruno , Pons Marie‐Noëlle 
Published: December 2004

AbstractThe characterization of the concave crystal shapes obtained during precipitation in a well mixed reactor of alkaline earth and transition metal oxalates by means of a morphological spectral analysis method is proposed. The method is based on series of openings performed on the crystal outline and on its complement with respect to its convex hull. Four parameters are used to describe and classify the shapes. The method can be applied to any concave shape.
Simultaneous Measurement of Velocity and Equivalent Diameter on Non‐Spherical Particles
Authors: Morikita Hiroshi , Hishida Koichi , Maeda Masanobu 
Published: December 2004

AbstractThe performance of a laser‐based optical technique to measure simultaneously the velocity and equivalent diameter of nonsphercial particles was evaluated. The size information was provided by the absolute intensity of diffractively scattered light by a particle crossing a single laser beam, which is concentric with a laser Doppler probe volume. The response curve (size‐intensity relationship) of the technique was estimated by calculations using the Fraunhofer approximation. Experiments with spherical glass and polyethylene and non‐spherical metal and ceramic particles ranging from 20 to 200 μm confirmed the operation of the technique and in all the measurements the maximum error of the average diameter was 10 μm as compared with size information provided by a microscope.
Experimental Investigation of Particle Collection on Single Fibres of Different Configurations
Authors: Schweers Elke , Umhauer Heninz , Löffler Frendrich 
Published: December 2004

AbstractThis presentation is part of a fundamental investigation into the influence of structural characteristics on particle collection in fibrous filters. The collection on single fibres has been experimentally determined, whereby different fibre configurations were set. For this purpose, particle fluxes upstream and downstream of the fibres were measured simultaneously using an optical particle counter which operates with two purely optically delineated measuring volumes and two detectors. The experimental results are compared with published values.
Strategies for Evaluating Boundary Fractal Dimensions by computer aided image analysis
Authors: Kaye Brian H. , Clark Garry G. , Kydar Yosef 
Published: December 2004

AbstractFor many profiles the values of the boundary fractals deduced by different exploration techniques are identical but the presence of deep fissures of convoluted structure can perturb the information gathered by the exploration technique. Data for different boundaries generated by different exploration techniques are used to illustrate the physical significance of the deduced fractal dimensions as evaluated using the different techniques. Heuristic programs for teaching an automated instrument to distinguish between different regions of ruggedness around a profile and to prevent “fractal rabbits” from appearing in the data are outlined. It is shown how the logic for removing fractal rabbits from the experimental data will also generate data on the presence of sharp edges on the profile. The possible occurrence of pseudo‐texture fractal dimensions from projection occlusion is discussed.
Obtaining Fractal Dimensions and Examining Boundaries by Coordinate Averaging
Authors: Adler Jeremy , Allen Martin 
Published: December 2004

AbstractProblems with automated techniques for measuring boundary fractal dimensions using structured walks are described and a new method is proposed, coordinate averaging. The actual polygon generated by a structured walk is variable and depends upon the chosen starting point. This noise is apparent in the resulting Richardson plots. The use of multiple starting points enhances the Fast (equipaced) method but is less productive with the Hybrid (fixed step) method because the paths followed around the perimeter tend to converge. Coordinate averaging uses perimeters that have been mapped as a list of sequential coordinates. They are then examined by averaging every coordinate with an increasing number of neighbours. The resulting family of shapes progressively shed detail and can be used to generate fractal dimensions. Coordinate averaging appears to be free from the noise found with structured walks and is able to examine highly convoluted shapes. In addition it appears well suited to the examination of the homogeneity of boundaries and can follow the detailed evolution of individual features.
Characterization of Agglomerated and Aggregated Aerosol Particles Using Image Analysis
Authors: Einar Kruis F. , van Denderen Jos , Buurman Hans , Scarlett Brian 
Published: December 2004

AbstractAccurate particle size characterization of aggregated and agglomerated particles is only possible by analysis of photographs. Both the primary particle size and the morphology of the aggregate are important experimental results. Since standard image analysis techniques for particle size analysis usually recognize only single particles, a new programme, called here Sparse Hough Transformation, was developed for the automated recognition of spherical particles within an aggregate. The method is shown to perform well, even for images with many overlapping particles. The structure of the aggregate is analysed using the fractal dimension, determined from the density‐density correlation function. Finite size effects, important when dealing with aggregates containing few primary particles, are taken into account by including a cut‐off function.
Flow Properties of Selected Pharmaceutical Powders from a Vibrating Spatula
Authors: Hickey Anthony J. , Concessio Neville M. 
Published: December 2004

AbstractStudies have been performed to characterize the flow of certain powders of pharmaceutical interest from a vibrating spatula. Lactose, cromolyn sodium, sodium chloride and charcoal powders were prepared by milling or sieving. Jet milling yielded micronized powder (1–10 μm), which was recovered from the product jar or metal cyclone. Particles in the larger size ranges were prepared by sieving. Photomicrograph images of the products were obtained by scanning electron microscopy. All of the powders were subjected to flow studies from vibrating beds to a top loading pan balance. Cumulative mass versus time, flow profiles were plotted. Bulk flow properties, as reflected in mass flow rates (Mi), were assessed. Irregular flow patterns were obtained for lactose, cromolyn sodium and charcoal, whereas sodium chloride was free flowing. The lengths of the lines depicting cumulative mass versus time, for samples of each material, were estimated using the inswing structured walk technique. Stride lengths (γ) of 1–100 mm were employed. Fractal dimensions were obtained from graphs of the logarithm of the cumulative mass versus time line length plotted against the logarithm of the stride length. Thus, flow irregularities were indicated by fractal dimensions (δ).In all of the powders studied, mass flow rates increased as the particle size increased. Sodium chloride did not exhibit fractal behavior (δ ≤ 1.007), as there were no flow irregularities. Lactose, cromolyn sodium and charcoal did not appear to exhibit fractal behavior (δ ≤ 1.010) at large stride lengths (γ = 15–100 mm). At small stride lengths (γ = 1–10 mm) these materials did exhibit fractal behavior (δ equals; 1.029–1.059) indicative of flow irregularity. This method may be used to numerically quantify uniformity of flow from a vibrating spatula, and would be useful in a number of industrial processes.
A Field Study of Three Collocated Ambient PM10 Samplers
Authors: Tsai Chuen‐Jinn 
Published: December 2004

AbstractThe performances of three ambient PM10 samplers were studied at three monitoring stations in Taiwan. It was found that differences in the daily measured PM10 concentrations of the SA 1200 and Wedding high‐volume samplers are now within ± 10% since the former now has a closer cut‐point to the latter than in the earlier SA 321 A model. The Wedding beta gauge automatic sampler was found to be applieable in rainy and humid weather conditions in Taiwan. Its daily PM10 concentrations are typically within ± 10% of those of the Wedding highvolume sampler. The particle loading effect of Wedding highvolume and beta gauge samplers was found to be important. To avoid sampling errors due to the loading effect with ambient PM10 samplers, they must be cleaned regularly at an interval depending on the ambient particulate level.
Interface analysis for the determination of the pH within the boundary layer at a cathode surface
Authors: Castle J. E. , Tremaine R. Tanner 
Published: December 2004

AbstractThe determination of pH value at a cathode surface requires the use of a technique capable of detecting the initial precipitation of a tracer ion. It is shown that XPS fulfils this role and that thicknesses of deposit may be estimated. The results can be correlated well with simple hydrodynamic theory and may be related to deposits formed on power station condenser tubes operating in sea water.
The significance of reduced thicknesses determined by XPS using the variable take‐off angle technique
Authors: Ebel Maria F. 
Published: December 2004

AbstractThe results of quantitative XPS analysis show a systematic change when the sample surface is covered by an overlayer. An accurate knowledge of the reduced thickness (x) of the total overlayer (e.g. oxide plus contamination) allows the quantification of such changes. The total reduced thickness (x) can be determined from the photoelectron signals of the substrate measured for different take‐off angles. It is found that this method can be applied for reduced thicknesses up to x = 3 with an error Δx estimated at less than 10%.
ESCA study of the effect of bivalent metal ions on lead ion selective electrode membrane
Authors: Young V. Y. , Kar Chaudhari Sunetra N. , Cheng K. L. 
Published: December 2004

AbstractESCA studies have been performed to investigate the exchange equilibria which occur between a lead ion selective electrode membrane containing multiple fixed sites due to surface degradation and various bivalent cations. The membranes have been exposed to solutions containing a single bivalent cation and to solutions containing Pb2+ and an equal amount of a second bivalent cation. The changes in surface speciation have been inferred from spectral intensity data. The possibility of obtaining exchange equilibrium constants from ESCA intensity data has been investigated.
A model for determining the composition of layer structured samples using XPS electron take‐off angle experiments
Authors: Hazell L. B. , Brown I. S. , Freisinger F. 
Published: December 2004

AbstractA model is presented for interpreting the results of electron take‐off‐angle(ETOA) experiments in x‐ray photoelectron spectroscopy (XPS). The surface region of a solid is treated as a multilayer structure where each layer is of homogeneous but different composition. The model is used to derive the true composition of a solid from the apparent compositions obtained by quantification of the spectra taken at each take‐off‐angle. All the species present are treated simultaneously to yield the physical structure of the surface region, within a maximum sampling depth of ∼5–10 nm, with no loss of chemical information. The validity of the model is demonstrated using ETOA data from a single layer of oxidised single crystal silicon. The derived layer stoichiometry and thickness agrees with the results which can be obtained using intensity ratio calculations which are restricted to the single layer case. As an example of the potential use of the model the structure of a Langmuir–Blodgett (L–B) film of cadmium stearate deposited on the oxidised silicon surface is investigated.