bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ion yield effects in the SIMS analysis of silicon delta‐doped layers in GaAs
Authors: Sharma V. K. M. , McPhail D. S. , Fahy M. R. 
Published: May 2005

AbstractEnhancements in the secondary ion yields of Si+ and As+ ions were observed in SIMS depth profiles of Si delta‐doped layers in GaAs when using oxygen primary ions. A systematic SIMS study of the enhancement in the intensity of the Si+ ion was carried out using a special test structure consisting of a series of layers with Si areal densities ranging from 0.01 monolayer (ML) to 2 ML (1 ML = 6.3 × 1014 Si cm−2). The enhancement effect was observed with layers above about 0.2 ML coverage and leads to erroneous measurements of the Si areal density for such layers. It was found that the level of the enhancement depended upon both the energy and angle of incidence of the oxygen ions. For a 2 ML delta, the level of the enhancement obtained with 5 keV O2+ ions at normal incidence was a factor of 1.2. However, using the same ion energy but changing the angle of incidence to 60° from the normal the enhancement obtained was almost a factor of 5. The enhancement was greatest when conditions for high depth resolution were used so that it was not possible simultaneously to achieve high depth resolution and accurate areal density measurements. The enhancements could not be removed by ratioing the silicon intensities to the As matrix lines (for which the enhancements are different). The enhancement effect was not observed when Xe+ or Cs+ primary ions were used and is predominantly an oxygen‐induced artefact.
Comparative film thickness determination by atomic force microscopy and ellipsometry for ultrathin polymer films
Authors: Gesang T. , Fanter D. , Höper R. , Possart W. , Hennemann O.‐D. 
Published: May 2005

AbstractEllipsometry and atomic force microscopy (AFM) were used to study the film thickness of continuous and discontinuous polymer films in the 1–20 nm thickness range on smooth silicon wafers and on structured aluminium substrates. The methods of exploiting AFM for thickness measurements with a high spatial resolution are described.For continuous films, the AFM method is a direct one, i.e. it does not rely on any model. There is excellent agreement between AFM and ellipsometry in the 1–10 nm thickness range. Very small systematic deviations occur in this range but big deviations occur above 10 nm, and are discussed. The film preparation method, spin coating, was characterized to result in prepolymer films with a very homogeneous thickness.Discontinuous films of 2–9 nm thick were also evaluated by both methods of thickness determination. In this case, for one of the AFM approaches a model has to be used too. The agreement between both methods ranged from very good to poor, depending on the kind of sample and on the kind of AFM determination method.
Oxidation of copper and mobility of copper ions during anodizing of an Al—1.5 wt.% Cu alloy
Authors: Habazaki H. , Shimizu K. , Paez M. A. , Skeldon P. , Thompson G. E. , Wood G. C. , Xhou X. 
Published: May 2005

AbstractThe mechanism of oxidation of copper at the alloy/film interface, and the subsequent migration of copper ions in barrier‐type films, has been examined for anodizing of an Al—1.5 wt.% Cu alloy with a prior chemical polishing treatment. Both chemical polishing and anodizing result in formation of a thin layer of alloy at the alloy/film interface, of ∼2 nm thick, that is highly enriched in copper. The layer is present immediately beneath the different types of film formed by chemical polishing and subsequent anodizing, and contains in both cases ∼6 × 1019 Cu atoms m−2. The amount of copper contained within the enriched layer of alloy is not significantly dependent upon the anodizing voltage. During anodic film growth, both aluminium and copper ions are incorporated into the film at the alloy/film interface, on average in their alloy proportions. However, the film is depleted in copper relative to the alloy because copper ions in the film migrate faster than Al3+ ions and, on reaching the film/electrolyte interface, are ejected directly to solution. The mechanism of oxidation of copper is proposed to depend upon the formation, through prior oxidation of aluminium, of copper‐rich clusters in the enriched layer of alloy at the alloy/film interface. Individual clusters are oxidized only on achieving a critical size. Consequently, copper is incorporated into the film discontinuously both in time and in position along the alloy/film interface. The films contain a high population density of flaws, which affects the film composition, the uniformity of ionic current, the faradaic efficiency of film growth, and the detailed distributions of copper ions within the films. However, the general features of film growth are compatible with the usual growth mechanism of anodic alumina, with transport numbers of Al3+ and O2−/OH− ions of ∼0.4 and ∼0.6, respectively.
The effect of organotin chlorides on the thermal stability of PVC
Authors: Wirth H. O. , Müller H. A. , Wehner W. 
Published: May 2005

AbstractMetal chlorides formed from metal stabilizers under processing conditions have an influence on the thermal stability of PVC. Zinc chloride, e. g., has a strong destabilizing effect, whereas lead chloride behaves almost indifferently. Alkyltin chlorides however, have a stabilizing effect in as much as they cause a significant retardation of the thermal dehydrochlorination rate of PVC. Using 1‐chlorobutene‐2 as model substance, a chloro allyl isomerization could be proved caused by organotin chlorides under certain conditions. These results support a complex chemical isomerization concept to explain the stabilizing effect of organotin chlorides on PVC.
Stabilizing polyolefins is as easy as 1‐2‐3 (so why stop at 2?)
Authors: Dieckmann Dale 
Published: May 2005

AbstractMost polyolefins require both free radical stabilization and acid neutralization. Conventional formulating follows a process of independent selection for stabilizers and neutralizers. This study shows that the use of a full factorial statistical design can facilitate concurrent optimization of neutralizer and stabilizer. A fractional factorial design did not provide sufficient information. Calcium lactate was shown to effectively improve YI color as well as neutralize acid residues.
Effects of thermal history on impact‐modified, high‐flow polycarbonate
Authors: Chung James Y. J. 
Published: May 2005

AbstractMiles Inc. recently developed an impact‐modified, high‐flow polycarbonate to help meet the material requirements for thin wall applications. Melt temperature and heat aging were found to affect its impact strength, yield stress, and dynamic mechanical relaxations. The results are explained in terms of the presence of polycarbonate's high‐energy intramolecular conformations formed as a result of intermolecular packing effects during molding, their rearrangement to trans‐tans conformations, and the increased interlocking between neighboring chains during heat aging.
The influence of the extrusion process on the quality of unplasticized polyvinyl chloride (UPVC) pressure pipe
Authors: Benjamin P. 
Published: May 2005

AbstractThe gelation level attained in an unplasticized PVC pressure pipe determines the balance in the basic physical properties of strength, stiffness and ductility. In turn, the gelation level attained is dependent upon the processing conditions. Measurement of the gelation level can be used to control both the process and the pipe quality. It is a vital parameter for the development of the extrusion process for pressure pipe with the required long term strength and for the control of the pipe quality during production. Maintenance of the correct level of gelation can ensure a pipe quality well above the specification requirements thus giving an extra margin of safety in addition to the official safety factor.
Processing aids for chlorinated polyvinyl chloride
Authors: Deanin Rudolph D. , Mast Jonathan D. 
Published: May 2005

AbstractComparative studies of melt processability showed that chlorinated polyvinyl chloride (CPVC) had low melt index and high Brabender melt temperature and torque, as compared with conventional rigid polyvinyl chloride (PVC). Of 3 processing aids at 10 percent concentration, triphenyl phosphate increased melt index 30‐fold, fusion rate 10‐fold, melt temperature 20°C, and torque 31 percent in CPVC. Two other processing aids, an acrylic and a styrene/acrylonitrile copolymer, were less effective. Improvements in PVC were less dramatic than in CPVC. Overall, use of processing aids made CPVC processability equal or even superior to conventional rigid PVC.
Application of SPC techniques to laboratory analysis
Authors: McNeese W. H. , Fenton J. T. 
Published: May 2005

AbstractEfforts aimed at improving or monitoring quality must be based on measurement systems that are accurate and precise. The accuracy and precision of measurement systems can be controlled by the use of statistical methods, in particular by the use of control charts. A procedure has been proposed that involves determining the stability and precision of a measurement system. Comparison of the precision with overall process variability allows the processor to decide whether the measurement is adequate for monitoring the process.
Dimensional stability of exterior building products
Authors: Rabinovitch Elvira B. 
Published: May 2005

AbstractDimensional stability problems such as warpage, bowing and other changes in shape and size may occur when exterior building products (siding, windows) are heated by the sun. This paper describes the effects of material properties such as coefficient of thermal expansion, heat distortion temperature, modulus, and heat build‐up, caused by the sun, on dimensional stability of the exterior building products.
PVC thermoplastic elastomers
Authors: Brookman Robert S. 
Published: May 2005

AbstractThe paper describes the development and properties of a new family of thermoplastic elastomers based on polyvinyl chloride.Comparisons of the new products with traditional flexible PVC's will be presented, pointing up differences in specific gravity, low temperature properties, heat resistance, melt viscosity, and general physical properties such as tensile modulus and elongation.The elastomeric properties of the new materials are explored and compared to some typical cured elastomers—chloroprene, chlorosulphonated polyethylene. The common thermoplastic elastomers based on block copolymers and polyurethanes are also considered in relation to the new compositions. Such properties as compression‐set, flex and fatigue resistance, oil and chemical resistance, weatherability, and performance at elevated temperatures are detailed.The unique feature of this technology that allows one to tailor the surface characteristics from typically high PVC gloss to the fine dull satin finish of cured elastomers is discussed.
Hot‐fillable vinyl bottles
Authors: Gruber C. M. , Patterson J. R. 
Published: May 2005

AbstractThe use of plastic containers will grow 11% per year over the next ten years as metal and glass decline. Plastic is the material of choice for food containers in all areas of food processing including hot‐fill and retort packaging. This is due in large part to the strides that have been made in barrier property improvement, better manufacturing, and improvements in the economics, esthetics, and physical properties of plastics. Hot‐fill and retort packaging account for approximately 64% of the total packaged foods, and in the next 10 years this is expected to increase to 68%. Of the two, the hot‐fill method reportedly will gain in importance while retorting will decline by about 1% per year in effect pushing the growth in hot‐fill packaging to about twice that of the overall food packaging business. Since 1980, PVC bottles have grown from 100 MM lbs to more than 200 MM lbs of resin in 1987 (growth of approximately 15% per year). However, PVC bottles still represent only 7% of all plastic bottles and only 1% of all materials used to make rigid containers—an indication of great future potential. One of the serious disadvantages of PVC, however, is its low heat resistance which limits the service temperature of finished articles to about 70°C. Further penetration by PVC bottles can be accelerated by raising the heat resistance above the hot‐fill levels of 85°C–100°C. This would permit PVC to be used for many food applications such as fruit juices and table syrups. Now an additive is available that can be formulated with PVC to form miscible, transparent blends with increased service temperatures. The miscibility of the glutarimide acrylic copolymers in PVC allows it to significantly improve heat resistance without effecting the optical properties of the container. As a result, single layer PVC bottles can be made on conventional blow molding equipment that can be hot‐filled at 85°C–100°C, have glass‐like clarity, with good impact and moderate oxygen barrier resistance. The discussion will include guidelines for compounding the imide copolymer with PVC, properties attainable, and a look at the economics versus other hot‐fillable containers.
Reaction between HC1 and orthophthalates of lead in hot DOP without PVC, and stabilization in plasticized PVC
Authors: Michell E. W. J. , Shah D. 
Published: May 2005

AbstractReactions between hydrogen chloride, HCl, and either hydrocerussite, 2PbCO3. Pb(OH)2, or an orthophthalate of lead suspended in di(2‐ethylhexyl)phthalate, DOP, at 180°C are discussed as models of what should happen during the stabilization of PVC if thermal dehydrochlorination were to yield HCl. There is a sharp contrast between the products of these model reactions and those actually found in plasticized PVC containing basic lead compounds. This is taken to show that basic lead stabilizing regimes inhibit PVC thermal dehydrochlorination, actually preventing the formation of HCl. It is proposed that these stabilizing regimes function by a free‐radical mechanism which has been called “true stabilization” for ease of reference.
Quantification and prediction of processing damage in extruded PVC
Authors: Riley David W. 
Published: May 2005

AbstractIt is known that oxidation occurring during processing of some polymers like PVC and polypropylene causes their deterioration. This, in turn, detracts from its service life. This study shows how the extrusion process shear can be detected and followed stepwise and in effect be controlled. Separate identification of fragmentation and crosslinking levels are determined. Quantification of shearing, fragmentation, and crosslinking of the PVC melt is used to derive service life loss due to extrusion processing.
Comparison of the time‐temperature curing dependence of industrial and dry blend modified plastisols
Authors: Mendizabal E. , Candia J. M. , Jasso C. F. , Cruz L. 
Published: May 2005

AbstractIn this work PVC plastisol rotational molding formulations were characterized as a function of processing conditions. Temperature sweep runs in the 60 to 220°C range suggest the presence of different stages in the solidification process, marked by the crossover of storage (G′) and loss (G″) moduli. Viscoelastic properties as a function of time were measured at different processing temperatures (in the 80 to 220°C range). Ultimate strength, ultimate elongation, and solvent resistance of the formulations after processing were also measured to evaluate performance.
Molecular weight and solution viscosity characterization of PVC
Authors: Skillicorn D. E. , Perkins G. G. A. , Slark A. , Dawkins J. V. 
Published: May 2005

AbstractAs a means of developing the most accurate possible Mark‐Houwink relationship possible for PVC, the literature Mark‐Houwink coefficients for the weight average molecular weight (MW) of PVC in THF are plotted and the derived “grand average” Mark‐Houwink relationship (K = 15.56 × 10−3 ml/g, a = 0.7690) is shown. High pressure‐size exclusion chromatography (HP‐SEC) data from two independent laboratories was used along with the “grand average” Mark‐Houwink coefficients to calculate absolute number of average molecular weight (MN) and weight average molecular weight values for PVC. An easy‐to‐use table has been developed to detail the relationships between MN, MW, K value, and inherent viscosity (I. V.).
Plasticizer structure/performance relationships
Authors: Krauskopf L. G. 
Published: May 2005

AbstractPlasticizers for poly(vinyl chloride) may be organized into eight chemical families and by seven key performance criteria. Cost‐effective general‐purpose phthalates provide a base line for comparing all other plasticizers. The wide range of performance characteristics associated with various phthalate isomers substantiates the large proportion of phthalate esters that are utilized as plasticizers. This article summarizes plasticizer structural/performance relationships using quantitative comparisons of cost, plasticizing efficiency, plastisol solvation characteristics, dryblending, volatility, and low temperature performance properties in PVC. Some generalizations are also made concerning structural effects of the alcohol isomers used in the syntheses of the various types of plasticizer esters.
Effect of crystallinity on PVC physical properties
Authors: Marshall R. A. 
Published: May 2005

AbstractCrystallinity in PVC contributes significantly to the strength and resiliency of the polymer. Two types of crystallites have been described: a primary crystallite in the virgin powder state pictured as a platelet or flat needle‐like lamellar crystallite, and a secondary, fringed micellar crystallite from melts or solutions. Both crystallites create loose, crosslinking networks. The secondary crystallite forms when plastisol melts are cooled or solutions are gelled. Crystallites exert a major effect on rheological properties. The thermal destruction of the primary crystallite networks in the melt phase results in a decrease in elastic modulus. Cooling from the fused state creates secondary crystallites that affect tensile and elongation.
X‐ray spectra calculator
Authors: Adam J. 
Published: May 2005

AbstractThe calculator is an aid to identification of lines in X‐ray emission spectra. It is designed to solve the well‐known Bragg equation: nλ=2d sinθ Principal X‐ray emission wavelengths (λ) of elements of atomic numbers Z=6 to 95 and lattice spacings (2d) of crystals commonly used in analysis are entered as data. The display of data is so arranged that line overlaps of the first and higher orders (n) of reflection can be seen at a glance for any spectrometer angle (θ or 2θ).
Comparison of phosphorus in some standard rocks by X‐Ray fluorescence analyses using the Ge (111) and PE crystals
Authors: Fregerslev Wilson S. J. R. 
Published: May 2005

AbstractPhosphorus has proved to be one of the most difficult elements to determine precisely in rocks by X‐ray fluorescence analysis. This is partly because of its low concentration in rocks, and because of interference from Ca 2Kβ and its associated escape peak when using the common crystals PE or EDDT. The Ge (111) crystal does not give any second order reflection. A comparison of phosphorus determined in some geological materials using PE crystal and electronic discrimination, PE crystal and manual discrimination and Ge (111) crystal is given.
Synthetic corundum as an X‐Ray monochromator
Authors: Belt R. F. 
Published: May 2005

AbstractSingle crystal boules of hexagonal α‐AI2O3 (corundum) were grown by the Czochralski method. The resulting size and crystal quality are appropriate for use as X‐ray monochromators. Eight corundum plates of various 2d spacings were fabricated and evaluated in both an X‐ray diffractometer and emission spectrometer. The corundum data were compared with crystals of ADP, Si, CaF2, Ge, NaCl, LiF, quartz and topaz. For X‐ray diffraction with Cu Kα the corundum (1014) cut is of highest intensity. It is about equal to all other crystals except NaCl (200) and LiF (200). The latter have respectively about 4 and 9 times the corundum intensity. In emissior spectroscopy at wavelengths of 0.1 to 0.5 Å, the corundum (0330) cut is superior to quartz (2023) and topaz (303). The intensity is 2 to 4 times higher for corundum. High resolving power can be attained by the corundum (1456) cut with 2d=1.660 Å. Data and applications are presented for this particularly useful crystal.
Analyse des Roches par une Méthode de Fluorescence X comportant une Correction Précise pour l′Effect interélément
Authors: Tertian R. , Géninasca R. 
Published: May 2005

AbstractNous avons appliqué la méthode de double concentration, dont nous rappelons brièvement le principe, à la détermination précise des constituants majeurs et mineurs, soit Fe2O3 MnO, TiO2, CaO, K2O, P2O5, SiO2, Al2,O3, MgO et Na2O, dans les roches silicatées ou apparentdées. Dans ce cas, la technique de la double mesure permet de corriger pour l'effet interélément avec une précision relative théorique de l'ordre de quelques dixièmes de pour cent et nous avons pu grâce des précautions particuliéres en ce qui concerne la préparation des “perles” vitri‐ fiées et la mesure des intensités nettes, porter la precision pratique à un niveau comparable. Une étude exploratoire alors menée sur quatorze roches étalons (dont sept du Centre de Recherches Pétrographiques et Géochimiques de Nancy et sept de l'U.S. Geological Survey à Washington) nous a conduits à des résultats très satisfaisants, en ce sens qu'ils concordent généralement avec les valeurs “recommandées” dans la limite de ±1 pour cent, voire mieux, en valeur relative. Un petit nombre de valeurs recommandées ou proposées, dans le domaine des très faibles concentrations, peuvent même être contestées ou améliorées.Cette méthode simple et directe qui nous dispense d'avoir recours à toute espèce de coefficients d'influence ou de para‐ mètres fondamentaux, ainsi qu'aux machines, est quasi‐absolue. On peut I'employer avec avantage non seulement pour l'analyse des roches et des composés similaires, mais aussi et même avec une précision encore accrue pour l'analyse des minerais en général.
Comparison of some procedures for X‐Ray fluorescence analysis of metallurgical slags
Authors: Carlsson G. 
Published: May 2005

AbstractSeveral procedures for X‐ray fluorescence analysis of slag including acid solution and fusing methods are compared. For eliminating erros due to inter‐element effects, heavy element addition and calculation methods are considered. Data of precision and accuracy are given for eleven different combinations. For routine operation fusing with borax and casting of a bead is recommended. Fusion in a semi‐automatic bead production machine is time‐saving, simple and more precise than manual operation and is described in some detail.
K emission and absorption spectra of nitrogen with the electron microprobe
Authors: Romand M. , Solomon J. S. , Baun W. L. 
Published: May 2005

AbstractThe K soft X‐ray emission profile of nitrogen in the vanadium nitride VN has been investigated with an electron microprobe. It is shown that this instrument is capable of sufficiently resolving the N K band to provide information about the filled states of the valence band. Moreover, with this same compound, the first K absorption spectrum of nitrogen has been obtained by a self absorption method. VN is only an experimental example. To find the complete picture of the electronic band structure of solid materials, similar emission and absorption spectra of nitrogen in some other interesting compounds can now be surveyed with the electron microprobe.
On‐stream energy dispersive X‐ray analysers
Authors: Carr‐Brion K. G. 
Published: May 2005

AbstractThe advantages and disadvantages of on‐stream energy dispersive analysers for X‐ray fluorescence and diffraction have been examined. These include factors such as ease of sample presentation, selection of exciting X‐ray energy, stability, count rate performance and microphony. Finally a number of applications and feasibility studies have been described including work for the cement, mineral processing, extractive metallurgy and related industries.