bluuebunny/crossref_metadata_2025_split huggingface dataset:
XPS investigation of oxide films on InP(100)
Authors: Hofmann A. , Streubel P. , Meisel A. 
Published: May 2005

AbstractThe effect of chemical etching and the oxide growth on the etched surfaces on n‐ and p‐InP(100) have been studied using X‐ray photoelectron spectroscopy. The samples were etched in HCI (1 molar in methanol) and then annealed at 650 K in a vacuum for 1 hour. After this procedure both samples were oxidized in air at room temperature for a long time. The stoichiometry of the oxide layer was determined by angle‐resolved analysis of core level spectra.The surface treatment leads to an indium‐rich surface. After annealing the In/P atomic ratios amount to 2.0 and 1.5 for n‐InP and p‐InP, respectively. Most of the oxygen on the surface after etching and annealing is presented as In2O3 and In(OH)3.Within the oxide layers of the air‐oxidized samples the In/P atomic ratios vary from 2.5 to 3.7 for both n‐ and p‐InP showing a depletion of P during the oxidation. From angle‐dependent measurements it is concluded that the oxide layers consist of InPO4 and In(OH)3 whereas the outer layer is InPO4‐rich. The presence of In2O3 can be suggested in the oxide layer of n‐InP only. The oxidized p‐type sample contains more oxygen than the n‐type one.
Calculations of electron inelastic mean free paths. III. Data for 15 inorganic compounds over the 50–2000 eV range
Authors: Tanuma S. , Powell C. J. , Penn D. R. 
Published: May 2005

AbstractWe report calculations of electron inelastic mean free aths (IMEPs) of 50–2000 eV electrons in a group of 15 inorganic compounds (Al2O3, GaAs, GaP, InAs, InP, InSb, KCl, LiF, NaCl, PbTe, SiC, Si3N4, SiO2 and ZnS). As was found in similar calculations for a group of 27 elements, there are substantial differences in the shapes of the IMFP versus energy curves from compound to compound for energies below 200 eV; these differences are associated with the different inelastic electron scattering characteristics of each material. Comparisons are made of the calculated IMFPs and the values calculated from the predictive IMFP formula TPP‐2 developed from the IMFP calculations for the elements. Deviations in this comparison are found, which correlated with uncertainties of the optical data from which the IMFPs were calculated. The TPP‐2 IMFP formula is therefore believed to be a more reliable means for determining IMFPs for these compounds than the direct calculations.
Some aspects of analysis and physical interpretation of LEIS spectra
Authors: Koksa Vít , Dřímal Jiří 
Published: May 2005

AbstractThere are a lot of open questions connected mainly with the quantitative interpretation of low‐energy ion scattering (LEIS) spectra. Interpretation of LEIS spectra from the qualitative point of view in terms of elemental composition is rather straightforward. The article is focused on spectra obtained by the scattering of inert gas ions and measured by electrostatic analyser. The spectra arising during scattering of non‐inert gas ions as well as the time‐of‐flight techniques are not discussed here.This article contains an overview of some phenomena influencing positions and shapes of peaks. A new effect—the shift of a peak position due to a neutralization phenomenon—is suggested here. A most simple model of collisions is used to provide some support for the choice of Gaussian functions in semi‐empirical models of the spectra. The simplicity of the model enables analytical treatment of the probability density function of the scattered particles. On the other hand, it excludes handling of realistic interaction potentials and of multiple collisions.
The cellular hydration state: role in apoptosis and proliferation
Authors: Schliess Freimut , Häussinger Dieter 
Published: May 2005

AbstractSmall cell volume changes occur within minutes in response to fluctuations of ambient osmolarity but also under the influence of hormones, substrates, second messengers, and oxidative stress. Isoosmotic cell swelling due to retention of inorganic ions and amino acids is obligatory during the cell cycle whereas cell shrinkage as a result of osmolyte release is an early hallmark of apoptosis known as apoptotic volume decrease. Cell volume changes are registered by osmosensing structures which trigger signals involved in the control of metabolism and gene expression. This review considers the hypothesis that cell volume‐dependent signals integrate into the overall signal transduction mediating apoptosis and cell cycle progression, respectively. Understanding the role of cell hydration changes in apoptosis and proliferation is of clinical relevance and provides novel therapeutic aspects.
Agitation scale‐up effects during VCM suspension polymerization
Authors: Lewis Max H. , Johnson Gary R. 
Published: May 2005

AbstractExperimental data are presented showing the effect of reactor agitation intensity and reactor size on final resin properties during VCM suspension polymerization. Experiments were carried out in three stirred batch polymerization reactors covering a broad range of vessel sizes (bench scale, pilot plant, and commercial production units). Reactors' shapes were geometrically similar. The same charge recipe and operating procedure was also used for all three reactors. The effects of major agitation parameters such as impeller diameter, width, and speed are correlated against resin properties using the Weber number. The same characteristic U‐shaped curve is found for all three reactors when mean particle diameter is plotted versus Weber number. However, the curves do not lie on top of one another but are spread apart, the larger reactors having a higher Weber number. Another interesting feature is that the coefficient of variation (particle size standard deviation divided by mean diameter) decreases dramatically as reactor size is increased. Other resin properties also show improvement upon scale‐up. In summary, resin properties continue to improve as reactor size is increased over the range studied (bench‐to‐commercial large reactor scale), but a correct application of the complex scale‐up technology must be employed to take advantage of this observation.
The nature of poly (vinyl chloride) crystallinity—the microdomain structure
Authors: Summers James W. 
Published: May 2005

AbstractThe microstructure of polyvinyl chloride (PVC) controls much of its processing and property behavior. A model put together from X‐ray diffraction and small‐angle scattering data, swelling data, and processing data shows that PVC crystallites, of a wide melting range and spaced at 0.01 micron, act as crosslinks in a three‐dimensional network. Tie molecules limit swelling by plasticizer. The network prevents strong primary particle interaction at low melt temperatures. At higher temperatures, partial melting and then recrystallization leads to strong ties between particles and a tough product.
Effect of temperature, shear and blending conditions on the relaxation properties of milled and compression molded plasticized PVC compounds
Authors: Földes Enikö , Hedvig Péter 
Published: May 2005

AbstractBlended, milled, and compression molded plasticized PVC compounds containing 30 wt percent of DIOP plasticizer were studied by combination of low effective frequency relaxation methods. The compounds were found to be heterogeneous and the ratio of plasticized and unplasticized phases dependent on the processing parameters. There is a correlation between the mechanical strength and the phase structure of the system.
Melt extensiometer investigation of PVC pipe compounds
Authors: Pazur A. S. , Uitenham L. C. 
Published: May 2005

AbstractThe Rheotens melt extensiometer can be a valuable tool for developing and studying rigid polyvinyl chloride compounds. The Rheotens can relate effects of variables such as processing aids, lubricants, and extrusion conditions on compound extrusion characteristics and changes in the melt on a morphological and molecular level, adding to the understanding of the processing and physical properties development of PVC materials.
Effect of extrusion temperature on elongational flow behavior of PVC melt
Authors: Park Im K. 
Published: May 2005

AbstractThe effect of the sample extrusion temperature between 160° and 180°C on the elongational flow properties of a low molecular weight suspension PVC (unplasticized) has been studied with the Rheometrics Extensional Rheometer. The results of both the tensile creep measurements at a constant stress of 24 KPa and the stretching experiment at a constant strain rate of 0.01 sec−1 indicated the existence of a rheological transition at 185°C marked by the dual valued flow activation energy and also by the temperature dependence of the tensile stress‐strain curves. Increasing extrusion temperature increased both the flow activation energy and the extensional viscosity below the transition temperature.
Gelatinization efficiency of PVC plasticizers
Authors: Šimoník Josef , Jurosz Jindřich , Chytílek Jaroslav , Drexler Jiǰí 
Published: May 2005

AbstractA method of evaluating the gelatination ability of selected plasticizers can determine flow curves, critical temperatures, and times of gelation, and activation energies of flow for polyvinyl chloride/plasticizer mixtures. The flow analysis is based on transition of the heterogeneous mixture into the gelatination state based on changes in aggregation.
Fusion of PVC‐vinyl acetate copolymer plastisols
Authors: Garcia L. G. 
Published: May 2005

AbstractMicroscopic viscoelastic, and bulk property analyses of the fusion process of plastisols found that the viscoelastic analysis is a facile and sensitive tool for determining gelation and fusion characteristics. The viscoelastic measurements can be used to gauge the effects of molecular weight, different plasticizers, and percent vinyl acetate content on the fusion characteristics.
Role of poly(vinylchloride) and Di‐2‐ethyl hexyl‐phthalate in the smoke formation from plasticized poly(vinylchloride)
Authors: Michel Alain , Sainrat Alain , Bert Michel 
Published: May 2005

AbstractThe increase of the smoke level from PVC plasticized with di‐2‐ethyl hexyl phthalate with respect to the rigid PVC is caused mainly by interaction of the plasticizer with HCl evolved from the polymer when the temperature is higher than 200°C. This interaction causes the increase of the yield of phthalic anhydride probably through HCl as catalyst for DOP decomposition but phthalic anhydride formation parallels the formation of products enabled to increase the smoke level such as phthalic acid. In the presence of metallic compounds (iron, zinc, aluminium) it is possible to favor the formation of phthalic anhydride with respect to these products which are responsible for the smoke production. Then phthalic anhydride can be used as a tracer to estimate the efficiency of an additive or a combination of additives as smoke suppressant for DOP because its smoke level varies inversely with the yield of phthalic anhydride. The best combination to reduce the smoke level from plasticized PVC is obtained with the binary systems based upon copper compound, mainly efficient as smoke suppressant for PVC and either zinc or aluminium compounds, mainly efficient as smoke suppressant for DOP.
Three‐dimensional torque rheometry mapping of rigid PVC compounds
Authors: Pedersen Thomas C. 
Published: May 2005

AbstractThis paper presents an improved method for presenting torque rheometer data as it applies to rigid PVC extrusion compounds. During extrusion of rigid PVC, the compound is subjected to various degrees of heating, shearing, and compression. Three‐dimensional torque rheometry mapping can provide the rigid PVC formulator with greater insights into how a rigid PVC compound will perform on production extrusion equipment.
Electrical conduction and ultrasound wave propagation in particulate and short fiber composites of PVC. II: PVC‐Al coated glass fiber composites
Authors: Dutta A. L. , Misra A. K. , Singh R. P. 
Published: May 2005

AbstractPoly(vinylch1oride) composites containing 2 to 20 wt% of aluminum coated glass fiber (AlCGF) were prepared by the mechanical mixing and hot compression technique. Their electrical conduction and ultrasound wave propagation at frequencies of 2 to 9 MHz were studied. The electrical resistivity of these composites was lowered because of fiber‐fiber contact formation, which is evident from optical photomicrographs of the composites. Other morphological investigations, such as X‐ray diffraction and DTA, show matrix‐filler interaction. The limiting resistivity of PVC/AlCGF composite is 10 ohm‐cm at 14 wt% (8.11 vol%) of fiber concentration. Ultrasound wave propagation through these composites having fiber‐fiber contacts has shown that both absorption and velocity are high at 9 MHz. Other ultrasound parameters were studied, such as excess absorption, relative velocity, relative modulus variation with composition as well as with propagation constant. No definite correlation exists between electrical conduction due to fiber‐fiber contact formation and ultrasound wave propagation.
EMI shielding of intinsically conductive polymers
Authors: Shacklette L. W. , Colaneri N. F. , Kulkarni V. G. , Wessling B. 
Published: May 2005

AbstractResults of this study, in which shielding efficiencies are measured for a number of blends containing various conductive fillers including intrinsically conductive polymers, are reported. It is shown that a very high level of shielding performance can be achieved by use of intrinsically conductive polymers in thermoplastic blends and that the most reliable measure of this performance is obtained from far‐field shielding measurements. However, near‐field measurements provide a useful method for comparing the relative shielding effectiveness of different samples. A PVC blend containing nearly uniformly dispersed intrinsically conductive polymer proved to be the best performing sample.
Analogien zwischen der Röntgenstreuanalyse und der Röntgenfluoreszenzanalyse
Authors: Ebel H. , Ebel M. F. 
Published: May 2005

AbstractEs werden die Gleichungen fur die Primä, Sekundär‐ und Tertiäranregung bei der RFA verwendet, um aus Analogiebetrachtungen die Verhältnisse bei der Einfach‐, Zweifach‐ und Dreifachstreuung quantitativ behandeln zu können. Der charakteristische Quotient aus körent und inkohärent gestreuter Intensität wird sodann fur verschiedene Kohlenwasserstoffe berechnet und mit den experimentell gefundenen verglichen. Die Ursachen für den etwa 15 Prozent betragenden Unterschied werden diskutiert.
Some applications of a computer program for quantitative spectrochemical analysis
Authors: Gould R. W. , Bates S. R. 
Published: May 2005

AbstractIn the general application of the X‐ray spectrographic method, it is often difficult to obtain standards which closely approximate the unknown being analysed. One of the possible ways around this problem is to utilise a matrix correction procedure which does not, in principle, require large numbers of standard samples. One such method has been described by Birks and Criss and this paper describes the application of their program at the University of Florida where a wide variety of samples are encountered. Also discussed in the paper is the basis of the so‐called ‘Fundamental Parameter’ method which has provided the means of analysing with great accuracy certain binary and tertiary alloys. It seems that the method holds considerable promise for the analysis of ore deposits and the prediction of inter‐element effects.
A die for pelletizing samples for X‐ray fluorescence analysis
Authors: Fabbi B. P. 
Published: May 2005

AbstractThe preparation of pellets of powdered geological samples is a critical step in X‐ray fluorescence analysis. A special die has been designed to produce smooth surfaces on extremely durable pellets and to provide a protective, hard outer ring and backing. The outer ring minimises the deterioration of the edge that has in the past limited the usable life of the pellet. Repetitive preparations have shown reproducibility and homogeneity to be within normal counting statistics.
FeKβ1,3 X‐ray emission spectra from complexes which contain ferric iron in unconventional spin states
Authors: Urch D. S. , Webber S. 
Published: May 2005

AbstractIron Kβ′, Kβ1,3 X‐ray emission spectra are reported for complexes with spin‐states S = 5/2, 3/2 and 1/2. It is proposed that the highly asymmetric shape of the Kβ1,3 peak might be due to charge‐transfer processes occurring simultaneously with the 3p → 1s transition. Since these processes vary greatly with the nature of the ligands, only a qualitative relationship exists between the relative intensity of Kβ′ (to Kβ1,3) and the number of unpaired 3d electrons. However, if the ligand environment is held constant, then it seems reasonable to use Kβ′ : Kβ1,3 to determine the number of unpaired electrons.
X‐ray spectrometric analysis of trace elements in rocks. Correction for instrumental interferences
Authors: Bougault H. , Cambon P. , Toulhoat H. 
Published: May 2005

AbstractInvestigating trace element determination in rocks and taking into account possible instrumental interferences, it is shown that the general relationship between I (net peak intensity) and c (fluorescent element concentration) is (I – I0) M = Ac + B where M is the matrix effect correction factor and A is a constant proportional to the efficiency of excitation; B and I0 correspond to the intensities due to, respectively the scattering (especially, by the sample) of any instrumental interfering radiation, and a possible stray emission by the instrument itself. Using this equation under optimized conditions allows interferences as high as 200 ppm (if expressed in equivalent concentration) to be compensated without any significant decrease regarding the general accuracy of determinations.
Improved spatial resolution microanalysis in a scanning transmission electron microscope
Authors: Faulkner R. G. , Hopkins T. C. , Norrgård K. 
Published: May 2005

AbstractThe attachment of energy‐dispersive analysers to scanning transmission electron microscopes makes possible accurate high spatial resolution microanalysis. This paper quantifies the X‐ray spatial resolution obtainable for good sensitivity microanalysis as a function of microscope lens settings and primary electron beam accelerating voltage in a 200 k V scanning transmission electron microscope. It is shown that at 200 k V a resolution of approximately 500 Å is possible with a 1500 Å thick nickel–iron–chromium alloy specimen. At 100 k V the resolution drops to nearer 1000 Å These figures are supported by Monte Carlo calculations of electron trajectories in thin films. Comparisons of experimentally measured and theoretically predicted X‐ray intensities suggest a severe loss of signal intensity within the microscope; this loss becomes greater at higher accelerating voltages. The influence on microanalysis of angle of specimen inclination to beam and to the detector is considered and precautions necessary to limit beam drift during 1000 s analyses are discussed. The application of high sensitivity, high resolution microanalysis methods to a grain boundary segregation effect in an austenitic creep resistant steel is described. It is shown that titanium segregates in a zone 1000–1500 Å thick on either side of the grain boundary to a level of approximately three times the matrix concentration.
X‐ray spectrochemical matrix correction in the analysis of copper ores
Authors: Hall Stephen H. , Harbison L. E. 
Published: May 2005

AbstractA graphical method of X‐ray fluorescence matrix correction is presented. Experimental evidence is based upon copper assays where sample matrix varies widely in the ore and smelter samples studied. Corrections are performed on concentrated, solvated samples, but the analyte peak alone is observed in practice.
Some comments on the deterioration of rubidium acid phthalate analysing crystals
Authors: Fregerslev Sidsel 
Published: May 2005

AbstractRubidium acid phthalate crystals are observed to decrease in reflectivity after being used for some time. During a period of three years the counts s−1 per % Na dropped by 80% compared with the new crystal. Very careful washing with water restored the counts s−1 per % Na to 70% compared with the new crystal.
Qualitative and quantitative analysis of technical aluminium phosphide
Authors: Mantler M. , Wernisch J. 
Published: May 2005

AbstractThe qualitative and quantitative composition of technical aluminium phosphide was studied employing X‐ray electron spectrometry, X‐ray fluorescence analysis and X‐ray diffractometry as well as gravimetric and gas volumetric methods. In addition to aluminium phosphide, AIN (8%), Al(1%) and Al(OH)3 (10%) were found. Al(OH)3 is produced by the reaction of AlP with H2O. Models describing this reaction in humid air and allowing for quantitative analysis are presented.
Relationship between the reciprocal of analyte‐‐line intensity and the reciprocal of weight fraction and its utilization in x‐ray fluorescence analysis
Authors: Asada Eiichi , Matsuda Shoji , Suzuki Yoshiko , Nakamura Mitsuo , Tone Toshiyuki 
Published: May 2005

AbstractUsing the effective wavelength concept, it is derived theoretically that the reciprocal of the analyte‐line intensity is linearly correlated with the reciprocal of the weight fraction of the analyte. This linear relationship is substantiated experimentally in some liquid and fusion product samples. Two ways of application of the relationship in X‐ray fluorescence analysis and their advantages are also described. It is emphasized that if the relationship is used the construction of calibration curves is not required.
Space resolved x‐ray spectroscopy for tokamak
Authors: Fraenkel Benjamin S. 
Published: May 2005

AbstractSpace resolved X‐ray spectroscopy with a curved crystal X‐ray spectrometer for an extended source such as the Tokamak is discussed. Limits of resolution caused by instrumental broadening are shown, using various entrance apertures. Ion density distribution may be obtained by measurement of intensity variation along spectral lines. In order to obtain ion temperature distribution about the central plasma line in the Tokamak, a novel method is proposed. In this method reflection in the curved crystal takes place through the double reflection process. This is possible as practically no instrumental broadening is caused when using this method, while it reflects the radiation in a strictly space resolved mode.
K and L x‐ray emission intensities of some radionuclides
Authors: Verma H. R. , Pal Dharminder 
Published: May 2005

AbstractThe K and L x‐ray emission intensities per 100 disintegrations have been calculated for some radionuclides using the latest adopted data for gamma‐ray intensities, electron capture and internal conversion coefficients for the parent nuclides, fluorescence yield values, Coster–Kronig transition probabilities, average total number of primary L shell vacancies produced in the decay of K shell vacancies and emission rates for various shells and subshells for the daughter nuclei. The results are in good agreement with theoretical and experimental values for the K x‐ray intensities. There are no experimental results available to compare with the present calculations for the L x‐ray intensities; however, there is a marked discrepancy in the Lα and Lβ intensities available on the basis of theoretical estimates.
Polarized x‐ray spectra of α‐Fe2O3
Authors: Leiro J. A. , Dräger G. , Czolbe W. 
Published: May 2005

AbstractThe linearly polarized Fe K absorption and Fe Lα emission spectra of α‐Fe2O3 were measured. Also, the usual Fe K‐emission band is presented. These measurements are compared with results of multiplet theory and cluster calculations. The spectra are also compared with x‐ray photoemission and inverse photoemission data as well.