bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ni surface chemistry and quality of the Al/Ni bond in electronic devices
Authors: Torrisi A. , Cavallaro A. , Licciardello A. , Perniciaro A. , Pignataro S. 
Published: May 2005

AbstractFour chemically different nickel surfaces, as revealed by ESCA, have been ultrasonically bonded to Al/Mg wires. Under normal conditions there was found to be very little difference in the pull strength of the various surfaces; there were small variations when the samples were tested in stress conditions such as high temperature storage (200 ° C), or a water vapour pressure environment (121 °C, 1.04 atm). However, the bonds have been found to be reliable for the four surfaces and when tested in the encapsulating resin environment of an actual electronic device. The thickness of nickel chemical species overlaying the nickel substrate was estimated to range from 5 to 13 Å for the four nickel surfaces simulating possible plant conditions. This relatively low thickness is considered to be responsible for the above positive results. These results are compared with those previously obtained for the Al/Cu joints.
XPS and AES studies of halofluorocarbon plasma etched surfaces
Authors: Occhiello E. , Garbassi F. 
Published: May 2005

AbstractIn situ AES and ex situ XPS studies have been performed on surfaces treated with haloflurocarbon plasmas. The quartz crystal microbalance (QCM) technique has been used to measure the corresponding etch rates.Silicon dioxide, polystyrene (PS) and polymethylmethacrylate (PMMA) show comparable trends in etch rates, they seem to react preferentially with fluorine. On the surface of silicon dioxide a silicon oxyfluoride layer is formed as a consequence of plasma treatment. Such a layer is virtually unaffected by the change in the discharge gas.PS and PMMA surfaces react also with chlorine and bromine, to give derivatization. The reactivity of polystyrene is higher, probably owing to the presence of aromatic rings allowing addition and electrophylic reactions, while in polymethylmethacrylate only substitution reactions are possible.
An energy‐resolved, electron‐stimulated desorption study of hydrogen from cleaned and oxidized Si(100)
Authors: Corallo Cheryl F. , Hoflund Gar B. 
Published: May 2005

AbstractElectron‐stimulated desorption (ESD) was used to study the hydrogen present on cleaned and oxidized Si(100), Cleaning the surface by ion bombardment and annealing does not completely remove hydrogen from a Si(100) surface. Kinetic energy analysis of the hydrogen ions emitted through ESD shows that multiple states of adsorbed hydrogen are present. Electron beam exposure results in a depopulation of higher energy states. These states are repopulated upon annealing suggesting that the bulk silicon is a source of hydrogen. Oxygen exposure also results in a depopulation of the higher energy desorption states. Angle‐resolved, energy‐resolved ESD spectra of H+ from the cleaned Si(100) surface were also collected. They show that different hydrogen bonding states desorb at different angles relative to the surface plane with differing energy distributions.
The additive heat history of PVC stability
Authors: Brown Randy 
Published: May 2005

AbstractA thermal stability test can determine the amount of residual stability remaining in a polyvinyl chloride compound after processing. Once the percentage of a compound's stability consumed in a given process is known, any regrind material can be tested to determine if it has sufficient residual stability to be reprocessed. Thermal processing also affects weathering, so the test can predict safe weathering limits.
A new method for judging efficiency of PVC impact modifiers
Authors: Goldman Theodore D. 
Published: May 2005

AbstractTo determine the efficiency difference between impact modifiers, S‐shaped polyvinyl chloride impact curves are compared. But in highly variable scatter regions, the position of the curves is uncertain. A new method focuses on the scatter region by statistically comparing percent ductility for different impact modifiers. If a sufficient number of samples are tested, percent ductility is a sensitive and reproducible function of impact modifier concentration and testing temperatures.
Effect of a variable diffusivity on the migration of vinyl chloride from poly(vinyl chloride) pipe
Authors: Vinson C. G. , Banzer J. D. 
Published: May 2005

AbstractMeasurements of the extent of vinyl chloride migration from specimens of processed poly(vinyl chloride) (PVC) are used to calculate the diffusivity of vinyl chloride in PVC pipe compound. The migration is strongly affected by temperature and is slightly larger into water than into air. The equation for calculating vinyl chloride migration from PVC must be generalized to recognize a variable diffusivity to be useful for non‐isothermal situations, as in the case of the measurements. The diffusivities calculated from the data with the generalized equation were confirmed by migration measurements from one in. pipe. Predictions with the calculated diffusivities and the generalized equation show that PVC pipe with a 3 mg/kg concentration of residual vinyl chloride will not release quantitatively detectable amounts of vinyl chloride (< .002 mg/kg) in a realistic time frame in potable water distribution.
PVC—gelation model
Authors: Parey J. , Menges G. 
Published: May 2005

AbstractThe plasticization of polyvinyl chloride proceeds in two stages. In the first stage, the PVC dry‐blend, under the influence of temperature and particularly of shear, changes into a material capable of gelling. In the second stage, mainly through the effect of temperature, this material becomes gelled. The shear serves here only to homogenize the material. Tests show that the stages do not necessarily have to follow one another directly in an extruder, but can take place separately in terms of both time and space.
Effects of preparation on physical properties of flexible PVC
Authors: Harrison William H. , Johnston William R. , Wadey Brian L. 
Published: May 2005

AbstractConditions used to prepare samples of flexible polyvinyl chloride for physical property testing were found to be very critical, particularly when a compound must meet certain requirements. Of the conditions tested, mill temperature had the greatest effect on physical properties: increases in mill temperatures led to increases in tensile strength. Press temperature, which depended on plasticizer and filler levels, had a minor effect. As the filler level increased or plasticizer level decreased, the effects of both mill and press temperatures decreased. There appears to be less scatter in the data with higher durometer and higher filled compounds.
Basic studies of smoke reduction in rigid poly(vinylchloride)
Authors: Guyot Alain , Michel Alain , Bert Michel , Van Hoang Tran 
Published: May 2005

AbstractA review of recent results in the literature and from our laboratory lead to drive a general picture of the combustion or rigid PVC as well as to the mechanism by which the most powerful additive can reduce the production of smoke. It is shown that, in smoldering condition the black smoke comes chiefly from direct volatilization of heavy tar molecules from the decomposing residue. The additives change the degradation process of the PVC by catalysis of the intermolecular crosslinking reactions, which compete with the intramolecular reactions leading to formation of benzene. Whatever their initial nature, they are at least partly transformed into chlorides and then into oxides during the combustion process. The oxide of Cu, Fe and also Zn are catalysts of the oxidation of the char residue, which may be partially inhibited by phosphorous compounds. The catalytic effects seem less pronounced in flaming conditions, which cause the productions of soots from the initial tars.
Investigation of multiphase polymeric systems of PVC
Authors: Singh Y. P. , Shaw S. , Singh R. P. 
Published: May 2005

AbstractGraft copolymers of chlororubber‐20‐g‐(ethylacrylate‐co‐acrylonitrile (2:1)) and chlororubber‐20‐g‐(styrene‐co‐vinyl acetate‐co‐acrylonitrile [1:1:1]) have been synthesized by solution precipitation polymerization technique. The graft copolymers have been characterized by elemental analysis, IR spectroscopy, and viscometry. The graft copolymers have been melt blended with PVC. The mechanical properties, such as flexural, tensile strength, and impact strength, of the blends have been studied to evaluate the relative performance of various graft copolymer blends of PVC as impact modified systems. Mechanical properties of the blends have been discussed in terms of morphology of impact fractured samples.
Thermal‐mechanical properties of PVC flame retarded alloys
Authors: Burke Dennis M. 
Published: May 2005

AbstractSeveral segments of the plastics conversion industry are concerned with meeting critical functional and performance demands. Relevant concerns include flame spread, smoke generation, and toxicity. In recent decades, the transportation and electrical/electronics industries have consumed tremendous quantities of polymeric materials. Many of these plastics have been extensively modified to meet flammability criteria, processability demands, and other functional requirements. Aircraft and electronics applications of these materials include printed circuit boards, electrical connectors, wiring, wire harnesses, and aircraft cabin flooring, ceiling, paneling, carpeting, and cargo storage bins. The traditional mechanism for imparting flame retarding properties is to incorporate external additives, which alter burning characteristics, but at the expense of functional properties. An alternate solution to flame retarding that has gained much attention in recent years is the alloying, or blending, of flammable polymers with inherently flame retarded polymers. ASTM protocol has established dynamic mechanical testing (DMT) techniques to evaluate the rheological properties of such materials. This paper exhibits how DMT can be used to monitor the solid properties of various flame retarded alloys.
Processable intrinsically conductive polymer blends
Authors: Kulkarni V. G. , Mathew W. R. , Campbell J. C. , Dinkins C. J. , Durbin P. J. 
Published: May 2005

AbstractBlends of intrinsically conductive polymers (ICPs) with conventional thermo‐plastics exhibit conductivities approaching those of neat ICPs and can be processed using conventional thermoplastic processing equipment. They display good environmental stability and mechanical properties suitable for commercial applications.
Recent developments in analysing crystals for X‐ray spectrometry
Authors: Jenkins R. 
Published: May 2005

AbstractThe usefulness of the analysing crystal is generally governed by its angular dispersion and reflecting power. This is particularly so today where the increasing requirement for more speed and greater accuracy can often only be obtained by the availability of higher net intensities. Although the performance of the conventional X‐ray spectrometer is satisfactory in the middle portion of the wavelength range, it lacks dispersion at the short wavelength end and sensitivity at the long wavelength end. For this reason, there is a continuing search for crystals which offer more angular dispersion in the 0.2 to 2 Å range and better reflecting power in the 5 to 20 Å region.This paper discusses results obtained with some of the newer analysing crystals which have become available during the past couple of years. These crystals include pyrolitic graphite, rubidium acid phthalate, sorbitol hexa‐acetate, and the (420) and the (422) cuts of lithium fluoride.
X‐ray tube excited fluorescence method using critical absorbers
Authors: Puumalainen P. 
Published: May 2005

AbstractCritical absorbers were employed to shape a quasi‐discrete excitation beam for X‐ray fluorescence analysis from the primary spectrum of an X‐ray tube. Also the elimination of the Compton scattered excitation peak seen by the detector was made adapting critical absorbers. In single heavy metal analyses the irradiation times needed in the present method were diminished by a factor of several orders of magnitude, with the same accuracy, compared with those needed in the conventional 241Am excited X‐ray analysis.
X‐ray production by 5.2–27 MeV alpha particles
Authors: Bădică T. , Ciortea C. , Dima S. , Petrovici A. , Popescu I. , Neacşu V. 
Published: May 2005

AbstractK‐shell ionization cross‐sections for Ni, Cu, Ge, Ag and Sn and L‐shell ionization cross‐sections for Sn, Au and Pb induced by α particles have been determined at 5.2, 16.5 and 27 MeV. Results have been compared with the predictions of the plane‐wave Born approximation (PWBA) and binary encounter approximation (BEA).
Pile‐up rejection: Limitations and corrections for residual errors in energy‐dispersive spectrometers
Authors: Statham Peter J. 
Published: May 2005

AbstractPile‐up rejection is commonly achieved through use of an auxiliary inspection channel with short time constants but low energy events can be missed because of electronic noise. A formula is derived to predict the detection efficiency of such a channel and the effect of adjusting the discriminator threshold or changing the time constants is demonstrated. When pulses are missed, spectrum distortion and counting losses are greater than would be predicted from the specified pulse pair resolution time so it is important to optimize the inspector adjustment. A mathematical analysis leads to formulae which can be used to correct for residual counting losses and sum peaks, and the relationship between empirical parameters obtained for these formulae and time constants in the electronics is demonstrated. The present state of the art in noise performance dictates that 1 μs is about the best resolution time that can be achieved for 1 ke V pulses. For further improvements, a fast beam switching technique could be used which would improve pulse pair resolution by a factor of three or more and thus afford adequate protection for the very low energy pulses that would be encountered with thin‐window or windowless solid‐state detectors.
Correction for matrix effects in x‐ray fluorescence analysis of finite media
Authors: Ben‐Haim Yakov 
Published: May 2005

AbstractA procedure is presented for constructing calibration curves of X‐ray fluorescence activity versus analyte concentration for finite multicomponent media. The composition must be known for all components other than the low‐concentration analyte. If these compositions are not known, the system's mass absorption coefficient must be measured. The analyte must be present in low enough concentration so that it does not contribute significantly to the total mass absorption coefficient. The calibration curve for a multicomponent system is constructed numerically from data on analyte activity versus secondary component composition in binary systems (analyte plus one secondary component). Thus calibration curves for any system containing the analyte and n secondary components are constructed from data on the n corresponding binary systems. The method is found to reproduce measured activities of uranium solutions with an accuracy of 5–7%.
Quantitative röntgenfluoreszenzanalyse mit hilfedes linearen und quadratischen hybridmodells
Authors: Kloyber H. , Ebel H. , Mantler M. , Koitz S. 
Published: May 2005

AbstractDas Konzept der hybriden Röntgenfluoreszenzanalytk ermöglicht die quantitative Bestimmlung einer Probenzusammensetzung mit Hilfe einzigen Standardpprobe und der Kenntnis von theoretischen Zusammenhängen im Sinne der fundamentalen Parameterrechnung. Die gesuchten Konzentrationen werden aus einem Differentialausdruck berechnet, der die Zählratenänderungen als Funktion von Konzentrationsänderungen beschreibt. Im Fall des Linermodells wird diese Funktion liner approximiert, im quadratischen Modell durch eine Funktion zweiter Ordnung. Die vorliegende Arbeit geht von dem Linearmodell aus, das von Kramer, Ebel und Tschismarov vorgestellt wurde und ergänzt es zur verbesserten Bestimmbarkeit kleiner Konzentrationen. Die Ergebnisse der Theoretischen Gegenöberstellung von linerarem und quadratischem Modell werden mit experimentellen Ergebnissen belegt.
A practical relation between atomic numbers and alpha coefficients
Authors: Lachance G. R. 
Published: May 2005

AbstractA first approximation indicates that fundamental alpha coefficients for a given analyte vary as a function of the ratio of their respective atomic number raised to a power. This simple rule applies mainly at the limits (i.e., when the weight fraction of analytei, wi is of the order of 0.0 or 1.0) in cases of absorption and weak enhancement. The relation thus provides a means of generating coefficients for the system i‐k from experimental data obtained on system i‐j and a means of verifying experimental alphas, since arrays of coefficients must show a high degree of concordance.
Analysis of geologic materials using an automated x‐ray fluorescence system
Authors: Schroeder Brian , Thompson Geoffrey , Sulanowska Margaret , Ludden John N. 
Published: May 2005

AbstractThe use of an automated, software‐controlled X‐ray fluorescence spectrometer (Phillips AXS System)for analysis of geologic materials gives rapid, precise results. Fluorescence intensities are corrected for background and peak overlap and for mass absorption, and ratioed to a standard rock analyzed at frequent intervals. Major element determinations show precision and accuracy in the 0.5–3% range and are based on calibration with a wide variety of international reference rocks. Determinations for major elements are done on specially fused rock powders. Precision and accuracy for trace elements are generally in the 1–5% range. Calibration is also by use of reference rocks but the determinations are done directly on pressed rock powders.
Multielement thin film standards for XRF analysis
Authors: Billiet J. , Dams R. , Hoste J. 
Published: May 2005

AbstractMultielement thin film standards are made by mixing a solution of different elements and a radioactive tracer (24Na) with the water soluble polymer mehtylcellulose. A film is produced by spreading the liquid mixture evenly on glass plates and letting it dry. Standards of the desired size and shape are punched out. The concentrations of the elements are calculated from the tracer activity. Ten sets of standards containing the elements Na, Mg, Al, Si, P, S, Cl, K, Cs, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Br, Rb, Sr, Ag, Cd, Sn, Sb, Ba and Pb in different groupings have been prepared. Homogeneity and accuracy oof the standards are extensively discussed. The accuracy is also estimated by the alalysis of the standards using several techniques. The precision of the analysis factors derived from the standards is better than 1–2%, while the accuracy for the elements Al, Cl, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Se, Br, Sb, Ba and Pb is found to be better than 5%.
Intensity for cubic particles in x‐ray fluorescence analysis
Authors: Bonetto R. D. , Riveros J. A. 
Published: May 2005

AbstractParticle size effects constitute a major source of error in the x‐ray fluorescence of granular material. Different models have been proposed to account for the influence of particle size on the characteristic x‐ray intensity leaving the sample. Important points in these models are the granular distribution from each grain. Berry et al. proposed a model which is in reasonable agreement with experimental values. In this work, fluorescent intensity calculations for a cubic particle with different geometries were carried out. The intensity values obtained through this model were compared with the Berry et al. model. There is better agreement with the experimental values when the expression obtained is used in order to find the total fluorescent intensity using heterogeneous samples consisting of fluorescent and non‐fluorescent components of particle size d.
Quantitative light element analysis using an energy‐dispersive detector: 2—continuum removal and peak deconvolution
Authors: Bloomfield D. J. , Love G. 
Published: May 2005

AbstractTechniques for analysing light elements by energy‐dispersive spectrometry are discussed and a new approach is proposed. Firstly, a method for predicting the x‐ray continuum level is developed. It is based on the use of a reference standard and, unlike other methods, is accurate below 1.5 ke V. When combined with methods for dealing with spectrum artefacts, this approach allows the calculation of background levels down to 0.1 ke V. Attention is then given to the problem of overlap, which is particularly important in light element analysis. Various methods for deconvolution of peaks are considered and a technique is adopted based on least‐squares fitting of standard peak profiles. The effects of count statistics and computational accuracy on the final results are discussed. Some practical overlap situations are examined to discover the level of accuracy which can be expected.
Quantitative x‐ray diffraction analysis on thin samples deposited on cellulose membrane filters
Authors: Battaglia S. 
Published: May 2005

AbstractExperimental mass absorption coefficients on thin‐layer samples deposited on membrane disc filters, consisting of mixtures of cellulose acetate and cellulose nitrate, were determined from the attenuation of a reflection of the crystalline material supporting the membranes. These mass absorption coefficients were used to carry out a quantitative x‐ray diffraction analysis on the same thin samples.
Inverse formulations of the Sherman equation for x‐ray spectrometry: A review of existing algorithms
Authors: Vrebos B. , Helsen J. A. 
Published: May 2005

AbstractA series of 12 correction algorithms for quantitative XRF analysis have been compared. The algorithms are applied to intensities, calculated by the NRLXRF program for hypothetical binary, tertiary and one more complex alloy. The influence coefficients are determined by a least‐squares procedure. It is shown that, when both enhancement and absorption occur, at least a two‐coefficient model is necessary and for more complex samples cross‐effect terms reduce the maximum errors substantially.
Some features of the Lachance‐Traill equation
Authors: Kuczumow A. , Helsen J. A. 
Published: May 2005

AbstractAll currently known changes in the values of the α coefficients in the Lachance‐Traill equation occurring under the influence of different factors are considered. These factors include the change in composition in connection with the enhancement phenomenon, the change in radious of grains (or lamellae) in a non‐homogeneous environment and the change of angle of the analytical surface slope relative to the ideal flat surface. Changes in the α coefficients are found to be always of hyperbolic character. A new version of the Lachance‐Traill equation has been derived.
Effects of chemical combination on x‐ray Kα emission spectra of chromium
Authors: Sarode P. R. 
Published: May 2005

AbstractAsymmetry indices, chemical shifts and full widths at half maximum intensity (FWHM) of the chromium Kα1 and Kα2 x‐ray emission lines were studied in chromium metal, some of its divalent, trivalent, tetravalent and hexavalent compounds, and minerals, catalysts and glassy materials by an x‐ray fluorescence excitation method. The asymmetry indices were found to depend on the number of unpaired 3d electrons. The chemical shifts, spin—orbit splittings, asymmetry indices and the half‐widths of both the X‐ray emission lines show interesting trends with the oxidation state of chromium.