bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metal formates as potential stabilizers for vinylidene chloride copolymers
Authors: Howell B. A. , Rajaram C. V. 
Published: May 2005

AbstractVinylidene chloride copolymers have a number of superior properties, most notably, a high barrier to the transport of oxygen and other small molecules. As a consequence, these materials have assumed a position of prominence in the packaging industry. At processing temperatures these copolymers tend to undergo degradative dehydrochlorination. The dehydrochlorination reaction is a typical chain process with distinct initiation, propagation, and termination phases. It has been demonstrated that initiation of degradation is strongly facilitated by the presence of unsaturation along the backbone. Such unsaturation may be introduced via interaction of the polymer with a variety of agents which might commonly be encountered during polymerization or processing. The presence of an unsaturated unit within the polymer generates an allylic dichloromethylene, which may function as a major defect (labile) site for the initiation of degradation. The conversion of these dichloromethylene units into nonreactive groups would interrupt propagation of the dehydrochlorination reaction and lead to the stabilization of the copolymer. Potential stabilization in the presence of metal formates has been examined using a vinylidene chloride/methyl acrylate (5 mol%) copolymer and thermogravimetric techniques. The effect of the metal formate on the stability of the polymer reflects the relative halogenophilicity of the metal cation present. Metal formates of low cation acidity [sodium, calcium, nickel(II) and to a lesser extent lead(II), cadmium, manganese(II) and magnesium] may be expected to be ineffective as stabilizers for vinylidene chloride copolymers. At the other extreme, metal formates that contain cations sufficiently acidic to actively strip chlorine from the polymer backbone, e.g., zinc formate, will function to enhance the degradation process. An effective carboxylate stabilizer must contain a metal cation sufficiently acidic to interact with allylic chlorine and to facilitate its displacement by the carboxylate anion. Copper(II) formate may possess the balance of cation acidity and carboxylate acitvity to function as an effective stabilizer for vinylidene chloride copolymers.
The weathering of vinyl siding
Authors: Stoloff A. 
Published: May 2005

AbstractThis paper describes the development of numerical color hold guidelines proposed as a replacement for the visual weathering standard in the ASTM specification for vinyl siding. Data are presented that indicate that maximum weather color change occurs after 2 to 3 years with very little change thereafter. After approximately 2 to 3 years, the averaged Δ L (lightness increase) for each color was greater at 90° south exposure than at 45° south exposure and Δ L changes were lowest in Arizona, with Florida next, and highest in New Jersey and Ohio. A mechanism is proposed with supporting data that gives an explanation for the observed weathering results.
Plasticization of PVC with ethylene copolymer resins
Authors: Hofmann G. H. , Statz R. J. , Case R. B. 
Published: May 2005

AbstractEthylene copolymer resin (ECR) modifiers, designed to be soluble in all proportions in PVC, form a wide variety of plasticized PVC blends. These solid, high molecular weight (Mw > 250,000) resin modifiers, unlike conventional liquid plasticizer, exhibit outstanding permanence in PVC. Compounding procedures, used for liquid plasticized PVC, are sometimes inadequate to produce homogeneous blends of PVC/ECR. A number of effective melt compounding techniques and a new family of ECR modifiers have been developed to produce homogeneous blends exhibiting many outstanding properties, including fluids/chemical resistance, high/low‐temperature service, and weatherability.
Data analysis for non‐statisticians
Authors: Neuman R. C. 
Published: May 2005

AbstractExperiments generate data. Data generate results. Results lead to decisions. Decisions solve problems. Right??? Well, not always. Things can go wrong….At the root of the above sequence is data. If the data are not good, the problem is unlikely to get solved. If the data are good, but not properly interpreted, the problem may persist.One cause of poor data is a poor experimental design. Once run, the results cannot be improved by the best data analysis techniques. Given good data, interpretation can change the conclusions. Data analysis techniques are available that enable the experimenter to

Correct for process drift during a series of experiments.
Study data for outliers, which can falsely influence results.
Determine distribution of data within and between data sets.
Do regression analysis to establish mathematical relationships.
These techniques lead to statistically correct identification of cause and effect relationships, or show that none are present in the data. Rigorous data analysis produces fewer disappointments and more problem solutions.
Single screw extrusion characteristics of a semirigid PVC
Authors: Burke Dennis M. 
Published: May 2005

AbstractPoly(vinyl chloride) compounds offer a wide range of properties from elastomeric to rigid. For this reason they are well suited for many extrusion applications. However, many processors shy away from PVC because of its challenging process‐ability: PVC is shear sensitive, susceptible to thermal degradation, and highly elastoviscous. This study, although limited, attempts to remove some of the complexity behind PVC extrusion. A semirigid PVC compound was processed on a small laboratory extruder. A factorial experiment was followed to determine the effects of barrel temperature and screw speed on melt temperature, residence time, output, and head pressure. Understanding these fundamental relationships is intrinsic to successful PVC extrusion.
Real time weathering as a test for evaluating materials
Authors: Scott John L. 
Published: May 2005

AbstractPerhaps as much as 75% of the material placed on exposure in outdoor test fields or in laboratory accelerated testing devices is on test because of a specification requirement that is a part of the condition of sale. Government standards, automotive manufacturers' specifications, and many architectural guidelines are filled with directives instructing prospective suppliers to expose the candidate material to specific weather durability criteria before they submit their product for consideration or acceptance. Approximately another 15% of the materials on exposure is for product warranty. Results from exposures performed in harsh climatic environments to a known industry standard are used to back up claims of product or material durability. Finally, there is a 10% group using exposure sites and laboratory weathering machines for research and development. An ever‐increasing demand for new and more durable products has made the seemingly simple task of weathering a key part of product development, quality assurance, and warranty. Even with the rapid technological improvements in field exposures, laboratory machines, test methods, and evaluation techniques there is mystery, mistrust, and misunderstanding of the weathering process. This paper discusses the reasons for and choices to be made when considering a program for assessing the ability of materials to resist degradation due to weathering.
Preparation of marked poly(vinyl chloride) by reactive processing for identification by UV devices (recycling)
Authors: Hidalgo M. , López D. , Mijangos C. 
Published: May 2005

AbstractThe grafting of sodium 2‐thionaphtholate (NaTN) and sodium p‐thiocresolate (NaTC) in poly(vinyl chloride) (PVC) has been studied in the melt with the aim of obtaining a marked polymer for easy recognition and separation by UV devices. The influence of reactant concentration. DOP concentration, and temperature was investigated to determine the best conditions to obtain a controlled modification in the polymer. High degrees of grafting, efficiencies > 80%, and no side reactions, such as degradation or crosslinking, have been obtained under polymer processing conditions. The reaction of PVC with both reactants is also stereospecific. The ultraviolet spectrum of p‐thiocresolate grafted PVC shows a maximum absorption in the region < 300 nm, and that of a 2% thionaphtholate grafted PVC in the region of 360 nm, which is far from the UV absorption of a plasticized PVC. While the polymer marked with the first reagent can be used without plasticized polymers, the second can also be used with plasticized PVC, and therefore distinguished from polyolefins. The results reported herein may be useful in the development of polymer recycling, although barriers and interferences can exist.
Vinyl durables recycling
Authors: Krause F. E. 
Published: May 2005

AbstractThe Geon Company and the vinyl industry have been very active in recycling for a number of years. A significant portion of that effort has been focused on the vinyl packaging, and the industry has been instrumental in getting automatic bottle sortation commercialized. This paper will focus more on vinyl durables recycling in wire and cable, computer and business equipment, and automotive. In addition it will address a number of environmental attacks currently leveled at vinyl.
Property enhancement of melt processable rubber by blending with thermoplastic and elastomer
Authors: Myrick R. E. 
Published: May 2005

AbstractThe effect of blending various thermoplastics and elastomers with melt processable rubber was studied using ECHIP experimental design. This study shows that with a minimum of tests, key property effects, interrelationships, synergisms, etc., can be identified. The data is useful in guiding the user to produce blends that will optimize properties within a given cost restraint.
Adaptation of solid state detector in X‐Ray powder diffractometry
Authors: Laine E. , Lähteenmäki I. , Kantola M. 
Published: May 2005

AbstractRapidly recorded X‐ray diffraction powder patterns from some metals and from rock salt have been obtained by using the energy sensitive Si (Li) semiconductor detector with the multichannel pulse height analyser. The measured energy resolution of the detector system was about 210 eV for Cu Kα radiation. A good agreement was obtained between observed and calculated positions and relative intensities of the diffraction lines.
The N900 non‐dispersive laboratory analyser
Authors: Gamage C. F. 
Published: May 2005

AbstractThe use of non‐dispersive X‐ray fluorescenceanalysis as a general tool in chemical laboratories has developed rather slowly until recently. Most analysers have used radioactive isotopes as the means of excitation and these have been widely used in portable instruments and in on‐line control applications. For general use wide element coverage is necessary, especially the ability to cover elements of lower atomic numbers. For the determination of these light elements a compact source—sample—detector geometry is essential. Early experiments in developing an on‐line system showed the possibilities of one such compact arrangement and resulted in an instrument specifically designed for use in the chemical laboratory. Solid, liquid and powder samples can be examined for silicon and all heavier elements. Basically, sample excitation is by radioactive sources but the instrument was designed to accept also a miniature X‐ray tube which provides higher sensitivity and precision. The measuring head with radioactive isotope or X‐ray tube can be removed and mounted for remote use either for on‐line applications or in an automatic sample presenter.
Quantitative results with X‐Ray fluorescence spectrometry using energy dispersive analysis of X‐Rays
Authors: Russ J. C. 
Published: May 2005

AbstractEnergy dispersive analysis of X‐rays is a relatively new but rapidly growing technique for X‐ray fluorescence spectrometry offering simultaneous analyses of many elements with sensitivities to a few p.p.m. The digitally recorded spectra lend themselves to processing to remove background and interfering peaks. The net counts for each element can be converted to concentration using any of a variety of mathematical models for interelement effects. When proper specimen preparation is used, final accuracies of better than 1 per cent can be realised over much of the analytical range.
The Si(Li) X‐Ray energy analysis system: Operating principle and performance
Authors: Gedcke D. A. 
Published: May 2005

AbstractMajor improvement in energy resolution in the last two years have made the Si(Li) X‐ray energy analysis system a significant tool for X‐ray spectroscopy. Its high detection efficiency, coupled with ability to analyse for all element simultaneously, has led to the development of several new techniques for X‐ray analysis. This article reviews the present state of the technology for this instrument with respect to performance characteristics and operating principles. A brief reference to its more important applications is also included.
The analysis of Nickel, Gallium and Germanium in iron meteorites by X‐Ray fluorescence spectrometry
Authors: Thomas W. W. , De Laeter J. R. 
Published: May 2005

AbstractAn X‐ray spectrometric technique is described which enables nickel, gallium and germanium to be analysed in iron meteorites. It is important to know the concentration of these elements with sufficient accuracy in order to chemically classify iron meteorites. The spectrometer was calibrated against a set of ‘standard’ meteorites with well‐established compositions.To obtain better accuracy, modification to the geometry were made to improve the peak to background ratio and eliminate machine background. This enabled nickel, gallium and germanium to be analysed with accuracies of ±0.05 per cent, ±4 p.p.m. and ±9 p.p.m. respectively for counting periods of 1 min for nickel and 10 min for gallium and germanium at the peak and background positions.
The occurrence of parasitic reflections from LiF (220) analysing crystals
Authors: Post B. , Jenkins R. 
Published: May 2005

AbstractAn explanation is offered for the appearance of parasitic reflections from LiF (220) analysing crystals. The reflections appear to stem from an unrestricted vertical divergence at the primary collimator allowing entry of reflections from planes other than that to which the crystal is cut. Careful orientation of the crystal boule before cutting would seem to offer the most convenient way of avoiding the problem.
Analysis of manganese–zinc ferrite by an X‐ray fluorescence method
Authors: Murata Michihiro 
Published: May 2005

AbstractAn X‐ray fluorescence method for the determination of zinc, manganese and iron oxides in manganese‐zinc ferrite has been developed. The content of zinc oxide is determined by using a calibration curve since a variation in the composition of the matrix only slightly affects the intensity of the Zn Kα line. The interelement effect on the intensities of Fe Kα and Mn Kα lines is ignored by the measurement of the intensity ratio, IFe Kα/IMn Kα. The contents of iron and manganese oxides are determined by the method based on the ratio measurement. The proposed method gives a standard deviation of 0.047, 0.047 and 0.030 for Fe2 O3, MnO and ZnO determinations, respectively.
The denver X‐ray conferences
Authors: Newkirk J. B. 
Published: May 2005

AbstractThe Denver X‐ray Conferences are known to X‐ray analysts all over the world and the August meetings are looked forward to with cosiderable entusiasm by the conference regulars. Even those who have never been fortunate enough to attend one of the meetings are able to follow the presentations by means of the excellent conference books Advances in X‐ray Analysis which appear in the Spring following the meeting. The following contribution has been prepared by Professor Newkirk of the University of Denver, who has been active for a number of years on the local Denver Conference committee. Professor Newkirk gives a short history of the conferences and includes some interesting insights into the technical and doemstic arrangements.
Determination of carbon in sediments by electron beam X‐ray excitation
Authors: Poole A. B. 
Published: May 2005

AbstractCarbon has been determined in sedimentary rock samples using a series of artificial standards. C Kœ line positions for elemental carbon and carbon combined as carbonate differ by 0.51º θ: using an OHM analysing crystal. A ratio of the intensities at the two line positions allows the proportions of combined and elemental carbon present in a sample to be estimated. This proportion is then used to obtain the correct calibration slope factor for the determination of total carbon in the sample.
Data for graphical resolution of two overlapping X‐ray emission lines. Natural widths of K of the elements Z = 10 to 92
Authors: Pessa V. M. 
Published: May 2005

AbstractThe energy difference between two overlapping X‐ray emission lines with Lorentzian shapes has been calculated as a function of the total line profile for several combinations of intensity ratio and half width ratio of the component lines. Natural line widths of Kα1 and Kα2 for neon to uranium are listed from available literature values.
Application de la Spectrométrie de Fluorescence X á la Mesure de l'Espace de Diffusion du Brome dans le Corps Humain
Authors: Bador R. , Vandroux J. C. , Barbier Y. , Girard C. 
Published: May 2005

AbstractLe volume de liquide extracellualaire (LEC) chez l'homme estun parameétre important pour la deétection de certins eétats pathologiques. La spectromeétrie de fluorescence X permet de mesurer avec une bonne preécision I'espace de deffusion de I'ion bromure et d'en deédrire la valeur du volume de LEC. La meéthode consiste en un dosage direct du brome stabel (80Br) à faible concentration dans les liquides biologiques, en utilisant la raie Br Kα Une étude paralleéle au moyen d'un radiotraceur (82Br)permet de tester la valcur de la meéthode.
The effect of compton scattering on high energy X‐ray fluorescence
Authors: Carr‐Brion K. G. 
Published: May 2005

AbstractThe effect of Compton scattered γ and X‐rays on fluorescent intensities is examined for heavier elements when using radioisotope excitation. It is shown to have a major effect in aqueous solutions and the implication of this on mathematical correction procedures is briefly discussed.
Concerning interelemental crossed effects in X‐ray fluorescence analysis
Authors: Tertian R. 
Published: May 2005

AbstractFluorescence crossed effects are discussed as to their exact significance, and relative importance regarding quantitative analysis. While they do not occur in binary systems, crossed effects appear when a fluorescent element is influenced by two or more interfering elements, more particularly when it is subject to enhancement effects. Dissociating crossed effects from pure binary interactions enabled us to establish an accurate general equation for expressing interelement effects in accordance with fundamental theory, and then the associated corrections in any analytical system. As a rule, practical applications should include some suitable modification of the general formula, with respect to the magnitude of corrections for the particularsystem considered.
A new method for first order line interference correction in X‐ray spectrochemical analysis. Application to the analysis of geological samples
Authors: Brändle J. L. , Cerqueira M. I. , Polonio J. B. 
Published: May 2005

AbstractA mathematical procedure used for correcting the interference between two nearest first order overlapping lines is described. The intensity of the ‘composite’ peak is assumed to be a linear superposition of the individual components; the shift in angular position of the sample. The proposed method is based on the dependence existing between the different parameters involved, which can be represented by a mathematical relationship of the [Ri]=[kij] [Cj], where Ri is the observed intensity, measured at the theoretical 2θ values for the elements involved, Kji are characteristic constants of the angular position and Cj the concentration of the elements.
Theoretical determination of BA/Ti molar ratios of titanates by X‐ray fluorescene spectrometry
Authors: Murata Michihiro 
Published: May 2005

AbstractA mathematical approach for determining Ba/Ti molar ratios of barium titanates has been made. A computer program applies the necessary corrections for absorption and secondary fluorescene. The method requires no standards and appears to be sufficiently accurate over large compositional variations. Evaluations of the magnitude of the secondary fluorescence contributions on TiKα intensities are given.
Incidence, detection and monitoring of radiation from X‐ray analytical instrumentation
Authors: Jenkins R. , Haas D. J. 
Published: May 2005

AbstractThe incidence of actual and potential radiation accidents is discussed along with the biological effects which have been observed as a result of known incidents. Recommendations are put forward whereby a given operator can reduce the possibility of accidental exposure. A description of active and passive monitoring devices is also given along with a set of guidelines for their selection and use.
Examination of paint smears on clothing by X‐ray fluorescence spectrometry
Authors: West John C. 
Published: May 2005

AbstractDirect X‐ray fluorescence analysis of pieces of cloth cut from clothing on which there is a suspected paint smear has been found to be a useful forensic technique for comparing a reference paint sample with the smeared substance. Even though the X‐ray method does not compare all the constituents of the paint, it may often be sufficient to distinguish rapidly between two suspect paint sources, and can therefore be a valuable method in paint transfer cases such as hit and run accidents. A feature of the method is that elements present in the cloth, such as sulphur in wool and titanium in some synthetic fibres, can be used as internal standards.
Note on the accuracy involved in the use of effective mass absorptiobn coefficients in X‐ray fluorescence analysis with polychromatic radiation
Authors: Mencik Zdenek 
Published: May 2005

AbstractThe question as to whether the multiple least squares regression of X‐ray fluorescence analytical data used in an earlier paper and based on an equation derived for excitation by monochromatic radiation can be considered as valid with sufficient accuracy in an experimental system using polychromatic radiation as source of excitation was examined. The results of computer simulation of the process of X‐ray fluorescence show that although definite differences in the intensities of fluorescent radiation arise as a result of the substitution of polychromatic primary radiation for a monochromatic source, the flexibility of the particular equation used for regression eliminates such deviations by incorporating them in the experimental regression coefficients. The overall accuracy of the regression was found to be satisfactory by any practical criteria.
Monte Carlo simulation of the X‐ray fluorescence excited by discrete energy photons in homogeneous samples including tertiary inter‐element effects
Authors: Gardner Robin P. , Hawthorne Alan R. 
Published: May 2005

AbstractA Monte Carlo model is derived for the simulation X‐ray fluorescence from homogeneous samples including primary, secondary and tertiary fluorescence events. The model is designed specifically for an annular radioisotope source mounted coaxially with a circular detector. It is verified with analytical relationships for the limited case of fixed sample entrance and exit angles. The results indicate accuracies (2% or better) that are well within our knowledge of X‐ray fluorescence parameters (such as fluorescence yields), yet can be calculated with very modest (15 seconds) digital computer calculation time.