bluuebunny/crossref_metadata_2025_split huggingface dataset:
Variations occurring in the light scattering film test
Authors: Duncan Carolyn B. , Chiasson Percy J. 
Published: May 2005

AbstractVariation in the results obtained in the Light Scattering Film (LSF) Test, also referred to as the Fog Test, presents problems both for the investigator as well as the formulator. The results are often confusing (two similar formulas will produce widely different results) and seldom repeatable. In the Fog Test high fog values are desired because high fog values mean less fog. The results of this study demonstrate that the standard deviation for multiple tests on the same sample decreases with increasing fog value. The values obtained when little LSF is produced (high fog values) vary only slightly while the values obtained for heavy LSF (low fog values) fluctuate as much as 30 points. Several explanations are offered for this lack of repeatability, but they condense down to the fact that all of the variables which affect the results are not presently controlled.The tests cited in this report were conducted using Di‐2‐ethylhexyl phthalate, Diisodecyl phthalate, and Di‐(1‐heptyl, nonyl, undecyl) phthalate as neat plasticizers from commerical suppliers. DOP was used because it is currently used by the SAE as an industry standard. The remaining two plasticizers were used because they are typically used in flexible PVC for automotive interiors. Results of this study confirm that the variations encountered in the LSF Test are inherent in the test itself and not due to the material being evaluated. Fluctuations which occur around a given LSF value occur to the same degree irrespective of the material producing the light scattering film.
Blowing agent decomposition in vinyl foams
Authors: Marshall R. A. 
Published: May 2005

AbstractAzodicarbonamide has been widely used for many years as the blowing agent of choice for expansion of vinyl foams. It has been especially useful in chemically embossed flooring because the sensitivity of the blowing agent to various factors affecting its decomposition temperature permits control of the degree of expansion of the foam. Considerable work has been done by a number of investigators to elucidate these factors. Mechanisms for the decomposition of azodicarbonamide have been proposed in the literature to explain the activating or retarding effect of many compounds on the decomposition temperature. The use of Differential Scanning Calorimetry with an active reference is shown to be an extremely useful tool in determining small effects of various additives on the decomposition temperature of the blowing agent.
The fusion characteristics of PVC‐plasticizer mixtures
Authors: Gonzalez‐Roa C. , Ramos‐Devalle L. F. , Sanchez‐Adame M. 
Published: May 2005

AbstractDry blends of a PVC resin with various plasticizer mixtures were processed at different temperatures to produce samples of different degrees of fusion. The ease of fusion increased with decreasing the solid‐gel transition temperature (Tm) of the plasticizer mixture. Nevertheless. Tm was not necessarily a linear function of the individual concentration of plasticizers in the mixture. Therefore, the ease of fusion showed in some cases an optimum at a given concentration of the plasticizer mixture.
Impact of the presence of amines on the degradation of vinylidene chloride copolymers
Authors: Howell B. A. , Liu H. 
Published: May 2005

AbstractBecause of the prominence of vinylidene chloride/methyl acrylate copolymers in barrier plastic packing applications, the degradation of these materials continues to be the focus of much interest. The prominent degradation process at moderate temperature (<200°C) is dehydrochlorination. This reaction is a typical radical chain process with distinct initiation, propagation, and termination phases. A principal defect structure responsible for the initiation of degradation is unsaturation along the polymer backbone. Although most stabilization packages for these polymers contain basic components to absorb hydrogen chloride as it is generated, materials sufficiently basic to abstract hydrogen chloride might actually enhance the rate of degradation by introducing double bonds into the polymer structure. That this is the case has been established by the thermogravimetric examination of the degradation of a methyl acrylate (5 mol%)/ vinylidene chloride copolymer in the presence of amines of varying base strengths. In general, the initiation rate constant, kt, for the degradation process is enhanced in the presence of amine.
Environmental concerns with vinyl medical devices
Authors: Rakus J. , Brantley T. , Szabo E. 
Published: May 2005

AbstractMore and more jurisdictions generate increasingly strict air quality regulations that, almost without exception, include limitations on vinyl chloride. Processors frequently express concerns about their ability to meet environmental and occupational safety VCM limits. To address these concerns, the paper traces residual VCM levels through various stages of conversion from raw PVC resin to finished product storage. Another environmental concern often raised involves the reusability of molded or extruded vinyl devices. While plant regrind is routinely fed back into virgin production and its effect on physical properties is well known, solid waste management considerations increasingly involve postsale reuse of devices, an area not well explored. This paper looks at the reprocessing following long‐time storage of devices, not only on physical performance but also on thermal and radiolytic (gamma sterilization) stability.
Extrudate swelling and viscoelasticity of rigid PVC compounds
Authors: Huneault Michael A. , Carreau Pierre J. , Lafleur Pierre G. , Gupta Ved P. 
Published: May 2005

AbstractIn this paper, we investigate the effects of processing aids, impact modifiers, inorganic fillers, and resin molecular weight on the postextrusion swelling of rigid PVC compounds. Rotational rheometry measurements of the loss tangent in dynamic mode and of the recoverable shear in creep mode are made to evaluate PVC's elasticity. Long elastic relaxation times are found for rigid PVC. This apparent contradiction, i.e., relatively low swell but very high elastic relaxation time, is explained by taking into account the two‐phase flow behavior of PVC.
Electrical conductivity of carbon black filled polymers—effects of morphology and processing
Authors: Lee Biing‐Lin 
Published: May 2005

AbstractThis paper discusses the relation of the morphology of conductive carbon black and its critical volume fraction, ϕc, required to achieve semiconductor property. We also discuss the influence of processing on the electrical conductivity of polymer composites. An equation based on the crowding factor of concentrated suspension rheology and Janzen's particle contacts percolation is proposed to describe the relationship between ϕc, and the maximum packing fraction of conductive fillers. The relationship could explain the influence of particle morphology on conductivity and the conductivity difference in the high shear and low shear region of a processed polymer composite part.
Effect of thermal aging on physical properties of impact‐modified vinyl
Authors: Einhorn Richard A. , Stevenson Janis C. 
Published: May 2005

AbstractMaintenance of physical properties after thermal aging is becoming more and more important for vinyl as the polymer makes further inroads into engineered applications. Many OEMs and regulatory agencies are now requiring that polymers used in business machine, appliance, and consumer electronic applications maintain both tensile and impact properties for long periods of time at high temperatures. The choice of impact modifier and other formulation ingredients appears critical to developing a successful compound that will maintain both tensile and impact properties after thermal aging. In this paper, we discuss the effects of different impact modifier types and other formulation variables on property retention.
Use of reflectance spectra to predict heat buildup of pigmented PVC panels
Authors: Sullivan T. , Peake G. 
Published: May 2005

AbstractWe present a method for predicting the heat buildup of pigmented PVC panels. Vinyl panels prepared for use in the ASTM D4803‐89 heat buildup test are scanned for percent reflectance from 200 to 2500 nm. For each sample an intensity factor is calculated according to:

where

IF = intensity factor,
Rλ = fractional reflectance of the sample at 20 nm intervals, and
Lλ = relative intensity of the heat lamp at 20 nm intervals.

A plot of the IF for each sample vs. its measured heat buildup (ASTM D4803‐89) for more than 50 sample panels containing a wide variety of pigments shows a linear relationship. Thus, the result in the ASTM D4803‐89 heat buildup test can be predicted based on the sample's reflectance spectrum and the intensity factor calculation. This method makes running the heat buildup test unnecessary and is very useful in evaluating pigments and pigmented systems for relative coolness.
SPC and the measurement process
Authors: Zuilhof John D. 
Published: May 2005

AbstractThis paper presents the basic principles of SPC charts and how to employ SPC techniques in performing simple measurement accuracy and precision studies. Information on the concepts of variation, basic statistics, the normal distribution, and the central limit theorem are presented to set the foundation for SPC. With these concepts in place, it is possible to introduce the two SPC charts on which accuracy and precision studies can be based—individuals charts and X‐bar charts. Many other types of control charts exist that are not described in this paper, specifically, control charts for attributes data. These are generally not applicable to measurement accuracy and precision studies, and numerous texts are available that sufficiently detail control charts for attributes data.
Processing conditions optimization for PVC plastisol rotational molding
Authors: Mendizabal E. , Candia J. M. , Gonzalez‐Alvarez V. , Jasso‐Gastinel C. F. , Cruz L. 
Published: May 2005

AbstractIn this work we present the optimization of the processing conditions for PVC plastisol rotational molding. The effects of oven temperature, processing time, rotational, speed and amount of plastisol over the degree of curing, physical appearance, and mechanical properties of the molded articles were studied. Also, using a simple mathematical model to simulate the temperature profiles of the plastisol inside of the spherical mold as a function of time, the viscosity change of the plastisol with time is reported. A rotational molding machine laboratory size was used for the experiments. The oven (at different points) as well as the mold (at the inside and outside of the cavity) temperatures were measured as a function of time in order to get a better understanding of the curing process. Such data in conjunction with the model gives the support for process optimization and control.
Particle size effects in X‐Ray emission analysis: Simplified formulae for certain practical cases
Authors: Rhodes J. R. , Hunter C. B. 
Published: May 2005

AbstractThe Berry—Furuta—Rhodes model is used to derive formulae for the characteristic X‐ray intensity in specimens of ‘non‐infinite’ thickness, as a function of particle size both for discrete values and for continuous distributions, including the Junge distribution for aerosols. Significant simplifications in otherwise complex for mulae are obtained for a number of cases of practical importance, namely, thin specimens, monolayers and low or high packing fractions. The simplified working formulae consist of the equation for a thin, homogeneous specimen, multiplied by a grain size dependent factor. This factor is a function of fluorescent grain size only, so eliminating most inter‐element effects. Practical applications of these cussed, with special reference to energy dispersive X‐ray fluorescence analysis of thin briquetted specimens and of aerosols collected on filters.
LII,III emission and LIII absorption spectra of vanadium with the electron microprobe
Authors: Romand M. , Solomon J. S. , Baun W. L. 
Published: May 2005

AbstractThe characteristic LII,III X‐ray emission bands of vanadium in pure metal and nitrides VN0.82 and VN are investigated with an electron microprobe. Results are discussed in relation to the theories proposed in the literature. Also presented is the vanadium LIII absorption spectrum from the pure metal; this spectrum is processed by the self‐absorption method.
The deterioration in counting efficiency of a scintillation detector
Authors: Kerrigan G. C. , O'Connor B. H. , Thomas W. W. 
Published: May 2005

AbstractA description is given of the decrease in counting efficiency of a scintillation detector with time. The attenuation of an incident beam for various wavelengths was shown to be consistent with the observation that an amorphous layer had formed on the NaI crystal.
Quantitative electron microprobe analysis using a lithium drifted silicon detector
Authors: Reed S. J. B. , Ware N. G. 
Published: May 2005

AbstractPulse pile‐up, dead time, escape peaks, background, and peak overlap in Si(Li) spectra are discussed in relation to microprobe analysis, and procedures for carrying out the necessary corrections for quantitative analysis of elements of atomic number 11 to 30 are described. The accuracy is generally comparable with that obtained with crystal spectrometers, though the limit of detection (about 0.1%) is higher.
Hazards in the use of X‐ray analytical instrumentation
Authors: Jenkins R. , Haas D. J. 
Published: May 2005

AbstractThis paper outlines the potential hazards in the use of X‐ray analytical instrumentation and is composed of two major sections. The first section defines the terminology employed and outlines the causes and effects of radiation damage. Also covered is the national recognition of the problem which has led to present day legislation of dose levels. The second part is a verbatim copy of the report MORP 68‐14 Radiation Safety Recommendations for X‐ray Diffraction and Spectrographic Equipment by Moore and McDonald, and is reproduced by kind permission of the United States Department of Health, Education and Welfare, Bureau of Radiological Health.
The effect of crystal absorption on the instrument smearing function of a two‐crystal X‐ray spectrometer
Authors: Suoninen E. J. , Gregory T. K. 
Published: May 2005

AbstractThe instrument smearing function of a two‐crystal spectrometer in the (n, n) position having negligible vertical divergence has been calculated for an unpolarized incident beam assuming the crystals to be centro‐symmetric and to reflect according to the Prins‐Darwin theory. The results are given in terms of the parameters g and s̀ which describe the ‘overall absorption’ and the imaginary part of the structure factor, respectively. In the region g, s̀ σ ≤ 0.5 asymmetries of up to 60% are found in the smearing function. Variations of several tens of per cent occur in the half‐breadth as compared with the breadth obtained for a σ polarized beam with no absorption.In order to avoid the undesirable effects of absorption, silicon (111) crystals should not be used above wavelengths 3 to 4 Å. Suitable wavelengths for calcite (211) crystals are 3.07 to 6 Å.
A correction for interelemental background contributions in energy‐dispersive X‐ray (EDX) spectroscopy
Authors: De Jesus A. S. M. 
Published: May 2005

AbstractVarious ore fractions (and mixtures thereof), of which the main metallic components are iron, copper and zinc, were analysed by means of radioisotope X‐ray fluorescence spectroscopy using a Si(Li) detector. As a result existing equations which deal with interelement effects (selective attenuation and enhancement of characteristic radiation) were further developed, and a new set of general equations, which accounts for the important interelemental background contribution, has been formulated. Its validity has been experimentally tested over a wide range of concentrations which, in some cases, varied by as much as a factor of 200. Satisfactory results were obtained.
Utilisation du Cristal de Phtalate de Thallium pour l'Analyse en Fluorescence X dans le Domaine des Grandes Longueurs d'onde
Authors: le Sage R. Vié , Grubis B. 
Published: May 2005

AbstractLes cristaux de phtalate ont pour formule générale HOOCPhCOOX où X = TI+, Rb+, NH4+, K+ ou Na+ et leur structure est orthorhombique. Ils permettent d'explorer un domaine de longueurs d'onde allant jusqu' à 25 Å.Le cristal de phtalate de thallium récemment élaboré par la Société Quartz et Silice présente des performances qui, si elles étaient confirmées, lui permettraient d'entrer dans la gamme des cristaux analyseurs de base équipant la majorité des spectromètres.
Dilution method in quantitative X‐ray diffraction analysis
Authors: Clark N. H. , Preston R. J. 
Published: May 2005

AbstractThe theory of the single dilution and double dilution methods for quantitative X‐ray diffraction analysis is presented, and verified experimentally for the analysis of silica in a set of seven synthetic standards. Dilution methods are a new concept in diffraction analysis, and show advantages over other methods.
Ein Beitrag zur quantitativen Elektronen‐strahlmikroanalyse von Phasen in polierten Anschliffen von Silikatproben mit dem Raster‐Elektronemikroskop und energie‐dispersiver Messung der Röntgenstrahlung
Authors: Brandit M. P. , Blum F. 
Published: May 2005

AbstractIn diesem Artikel wird als Beitrag zur Elektronenstrahlmikroanalyse eine quantitaive röntgenographische Analyse von Phasen in polierten Anschliffen von Silikatproben beschrieben. Für die energiedispersive Messung der Röntgenstrahlung ist das Raster Elektronenmikrosk op mit einem Halbleitermessplatz und für Die Bilderzeugung mit einem Halbeitermessplatz und fü die Genauigkeit der Anlage und die damit erreichbare Nachweisgrenze werden bestimmt. Die Berechung der Konzentration wied nach einer von Salter vorgeschlagenen vorschrift mit Hilfe von binären Oxidsystemen und renien Oxiden als Standardproben berechnet. Als analytisches Bisipiel für die Elektronenstrahlmikroanalyse wurde ein Zementklinker gewählt.
Quantitative analysis using the absorption of white X‐ray radiation
Authors: Kähkönen H. , Suhonen P. , Yli‐Penttilä M. 
Published: May 2005

AbstractThe absorption of continuous radiation was used in X‐ray absorption analysis. The entire spectrum was measured simultaneously by using a solid state detector and a multi‐channel pulse height analyser. The analysis of the spectra was performed via a method, where only the energy spectrum but not the intensity of the primary beam need be known.
X‐ray fluorescence spectrometry on variable thin deposits of powdered materials
Authors: Frigieri Paolo , Trucco Renato 
Published: May 2005

AbstractThis work is aimed at providing a direct analytical method for powdered materials collected on cellulose filters. The origin and composition of these materials may be very different. The analytical technique employed was X‐ray fluorescence spectrometry without preliminary treatment of samples.It is known that different thickness of thin deposits, due for example to different sampling condition, cause some difficulties on the correct accomplishment of the analysis. To eliminate this drawback the basic principles characterising the behaviour of X‐ray penetration in the matter, were developed, thus leading to some equations, applicable to the analysis of the following kinds of samples: (a) sample of infinite thickness for X‐ray penetration; (b) sample of finite thickness below the critical value; (c) sample of infinite thickness placed over the sample of finite thickness.The equation relating to case (c) was then applied to the analysis of powdered materials collected on cellulose filters.A suitable plate of a selected metal was placed over the sample, and the fluorescence radiations intensity values of the element to be analysed were recorded together with the intensity of the radiation emitted by the plate.By substituting some terms of the above mentioned equation with experimental data, X‐ray intensity values were corrected, and then independent measurements were performed on the sample thickness.This work described both the theoretical part and the experimental procedures with results showing the method's reliability.
X‐ray fluorescence analysis of powder pellets utilizing a small quantity of material
Authors: Leoni L. , Saitta M. 
Published: May 2005

AbstractThe amount of material usually required for X‐ray fluorescene analysis of briquetted rock powders is of the order of 2 to 3 g. By reducing the diameter of the pellets and the cross‐section of the incident X‐ray beam, it is possible to analyse a small quantity of material (about 40 mg) reliably. The results obtained from the analysis of about 40 mg of powder for the major components (MgO, Al2O33, SiO2, P2O5, K2O, CaO, TiO2, MnO, Fe2O3) and for 12 trace elements (Cr, Ni, Cu, Zn, Ga, Rb, Sr, Zr, La, Ce, Ba, Pb) in 6 standard samples of rocks (US Geological Survey Standards: G‐2, GSP‐1, AGV‐1, BCR‐1, DTS‐1 and PCC‐1) are reported. These data are compared with those obtained from standard pellets and from literature values.
Zur experimentellen Bestimmung von Massen‐schwächungskoeffizienton mittels Röntgen‐fluoreszenz und variabler Strahlengeometrie
Authors: Mantler M. 
Published: May 2005

AbstractMit Hife eines speziell für variable Strahlengeometrie adaptiertenten Röntgenspektrometers wurden Massenschwaächungskoeffizienten nach den Methoden der Schicht‐und Trägerfluoreszez bestimmt. Besonderer Vorteil ist, daß Aufdampfschichten in experimentell guünstigen Schihtdickenbereichen als proben verwendet werden koönnen. Die Methode bietet sich an, wenn Folicn für die konventionellen Absorbermessungen nicht ausreichend dü hergestellt werden können.
Kβ/Kα intensity ratios for elements of atomic number 20 to 30
Authors: Smith D. G. W. , Reed S. J. B. , Ware N. G. 
Published: May 2005

AbstractTwenty‐five new measurements of Kβ/Kα X‐ray intensity ratios for elements in the atomic number range 20 to 30 confirm other recent evidence that the variation with atomic number in this region is much less than previously thought, but there is still some disagreement for atomic numbers above 27. A table of recommended values is given.
Die Korrektur der Probentransparenz in der Röntgenspektralanalyse
Authors: Weber Kurt 
Published: May 2005

AbstractDie Strahlendurchlässigkeit Von Proben mit vormiegend leichten Elementen (z.B.wässrige Lösungen, Schlacken, Mineralund Gesteinsproben) führt zu Fluoreszenzatrahlungsverlusten, die unter Berücksichtingung der Strahlengeometric berechnet Werden und deren praktische Messung beschrieben wird. Die Ergebnisse zeigen, dass die erforderlichen Korrekturen im Bereich der K‐Spektren etwa beim Element Rb (Z=37)mit maximal einigen %einsetzen und zum Ba (Z=56) hin rasch ansteigen, Durch Interpolation lassen sich alle in Frage kommenden Elemente an Hand einer einzigen Korrekturtafel erfassen, Die Durchfuhrung der Korrektur verlangt die Kenntnis des Matrixfaktors und des Probengewichtes und des Probengewichtes und erfordert keine zäsatzliche präparation.
Eichprobenfreie Bestimmung der Massenbelegung ebener dünner Schichten mit einem energiedispersiven Spektrometer
Authors: Ebel H. , Fuchs G. , Gurker N. , Wernisch J. 
Published: May 2005

AbstractDie röntgnfluoreszenzanalytiche Bestimmung der Massenbelegung dünner Schichten ist literaturbekannt. Diese Methoden bauen zumeist auf einem Vergleich mit Proben difinierter. Massenbelegung auf. Es wird von der Theorie her gezeit, wie eine eichprobenfreie Messung möglich ist. Neben einer Abschätzung der mit dieser Methode verbundenen Fehler Werden die Messungen mit einem energiedispersiven Spektrometer und die rechnerische Auswertung behandelt.