bluuebunny/crossref_metadata_2025_split huggingface dataset:
Scattering in electron spectrometers, diagnosis and avoidance. I. Concentric hemispherical analysers
Authors: Seah M. P. 
Published: December 2004

AbstractThe unwanted scattering of electrons in electron spectrometers leads to a loss of sensitivity, distortion of the spectral background and problems in calibrating spectrometer intensity/energy transmission functions. Here we develop three methods to analyse the extent of the contribution and how to reduce it to an insignificant level. The three diagnostic methods involve either the measurement of the region of the M4,5VV Auger electron peaks from Ag in AES, or the reflection of an electron beam from a biased sample, or the 3p1/2 photoelectron peak from Ag irradiated with Mg Kα x‐rays. In this work analyses are made for concentric hemispherical analysers. In Part II, cylindrical mirror analysers are studied. It appears that in our spectrometers, a modified VG scientific Escalab II with either the original analyser or a 210 analyser, the major scattering contributions arise from high‐energy electrons that strike the outer hemisphere giving rise to a spectrum of secondary electrons. These cause the scattered electron contribution to vary approximately as E, where Ep is the pass energy, to increae approximately in proportion to the spectrometer input slit area for AES studies, to fall approximately inversely with an increase in the lens magnification from 1 to 3 and, in the constant ΔE mode, to increase with the analysed electron energy. Thus, for each lens magnification, there exists a range of slits and pass energies for which the scattering may be maintained at <1%. In the constant ΔE mode, pass energies of ≥50 eV are generally safe, whereas in the constant ΔE/E mode, retardation ratios of ≤4 are required.
Controlled chemical oxidation of carbon fibres: An XPS–XAES–SEM study
Authors: Desimoni E. , Salvi A. M. , Casella I. G. , Damiano D. 
Published: December 2004

AbstractHigh‐modulus, polyacrylonitrile‐derived carbon fibres were chemically oxidized in concentrated sulphuric acid containing potassium permanganate. The pre‐ and post‐oxidation surface status of the fibres was characterized by x‐ray photoelectron spectroscopy, x‐ray‐excited Auger spectroscopy and scanning electron microscopy. Tests were made to evaluate the effects of temperature, time of treatment and permanganate concentration. The overall results are discussed in terms of flexibility and easiness of the treatment and of reproducibility of the chemical composition of the oxidized fibre surface.
Quantitative analysis with d.c.‐ and r.f.‐glow discharge spectrometry
Authors: Payling Richard , Jones D. G. , Gower S. A. 
Published: December 2004

AbstractGlow discharge spectrometry (GDS) is a technique for rapid depth profiling and bulk analysis of materials. The latest instruments can be operated in either d.c. or r.f. modes. The d.c. mode provides analysis of conductive materials only, while the r.f. mode allows analysis of both conductive and non‐conductive samples. Until now, no theory for r.f.‐GDS has been available. The recently proposed d.c. theory, which assumes that emission yield depends only on pressure, is extended to r.f.‐GDS and is shown to be valid for the r.f. mode as well. A key to the success of the theory is that, in support of Duckworth and Marcus, the two modes are shown to have similar analytical characteristics, e.g. in comparing the two modes most elements examined had similar sensitivity factors and background equivalent concentrations. This will facilitate calibration of the light elements hydrogen, oxygen and nitrogen for use in the d.c. mode. Recommended procedures for bulk analysis, in either d.c. or r.f. modes, are presented and illustrated for manganese in steel. Both modes provide calibration curves of high linearity. Quantitative depth profiles of three commercial metallic‐coated steel samples are compared in d.c. and r.f. modes and the similarity of the quantitative profiles, given the very different lamp parameters operating between the modes, confirms that the theory works for both d.c. and r.f. The theory is then applied to data from a commercial prepainted metallic‐coated sample to provide the first quantitative GDS depth profile of a non‐conductive material.
Influence of crystalline structure and amorphous materials in the depth resolution of sputter etching
Authors: Henneberg Matthias M. 
Published: December 2004

AbstractThe dependence of depth resolution Δz/z on the sputtering angle θ is investigated for three sputter‐deposited films: Cr (bee), SiNx (amorphous) and FeCoTb (amorphous). The depth resolution for the Cr system exhibits two maxima at θ = 35° and 45°. These are characteristic for bee textured material but different from fee textured material. The amorphous films show a very weak dependence, if any, owing to the absence of crystallites and crystalline texture. These results are in accordance with channeling theory.
GaAs/AlAs superlattice as a proposed new reference material for sputter depth profiling
Authors: Yoshihara K. , Moon D. W. , Fujita D. , Kim K. J. , Kajiwara K. 
Published: December 2004

AbstractA GaAs/AlAs superlattice growth by metal–organic chemical vapour deposition is being proposed as the single crystalline multilayer reference material for sputter depth profiling. This material was characterized by transmission electron microscopy experiments, which showed that the interface between GaAs and AlAs is atomically flat. The preliminary depth profiling experiments were carried out by AES and SIMS.The AES experiments were performed using a Perkin‐Elmer SAM 660 scanning Auger microprobe and the SIMS experiments were carried out using a VSW multitechnique XPS/SIMS surface analysis system.The AES and SIMS sputter depth profiling experiments proved that the depth resolution was found to be almost constant for each interface when an Ar+ beam was used for sputtering. Therefore the sputtering‐induced roughness is very small for this material with Ar+ beam profiling, the depth resolution deteriorated as a function of depth, indicating oxygen ion beam‐induced surface roughening.For both AES and SIMS, the depth resolution improved for ion beams with lower kinetic energy and more glancing angles of incidence.
New developments in profile extrusion expand the applications for plastics in the building industry
Authors: Fow Louis F. 
Published: December 2004

AbstractThe potential market for plastics in the building industry is discussed with particular emphasis on vinyls. Equipment advances for co‐extrusion and complex profiles are described. The use of capstock co‐extrusion is proposed as a route to dark‐color weatherability of PVC siding and building products. The transfer of European technology is suggested.
Weatherability of rigid vinyl siding
Authors: Weaver Leonard W. 
Published: December 2004

AbstractVinyl siding is described as a product in the early maturity stage of business development. The competitive position of rigid vinyl siding vis‐a‐vis other products is discussed. Total weathering exposures from point sources not usually thought of are reviewed. Methods of control for weathering caused changes as well as resistance evaluation are covered. The impact on the industry of the voluntary product standard PS55‐72 is mentioned.
Low temperature impact modification of injection molding PVC
Authors: Malpass V. E. , Gaggar S. K. 
Published: December 2004

AbstractTo meet the stringent requirements of PVC compounds intended for use in injection molded cabinets, housings and other electrical applications, impact modifiers are required which permit good melt flow while processing and allow passage of falling ball impact at −20°C. Extensive testing is described as differentiating the low temperature toughness imported by two similar impact modifiers which give the same mold flow in modified PVC.
Application of atactic polypropylene in technology of chemical foaming of PVC pastes
Authors: Šimoník Josef , Drexler J. 
Published: December 2004

AbstractA preliminary study of the use of by‐product atactic polypropylene as a replacement for plasticizer in chemically blown plastisol is presented. The effect of varying amounts of PP and plasticizer on the elastic property was studied. Atactic PP has been shown to be useful as a plasticizer substitute in plastisols in amounts apt. 10%.
On the particle formation mechanism of poly(vinyl chloride) (PVC) powder produced by suspension polymerization—development of external morphology of particles
Authors: Máriási Béla 
Published: December 2004

AbstractIn the first part of the paper the author critically surveys literature dealing with the main factors determining the external morphology of particles of polyvinyl chloride powders, then offers a new model and theory of particle formation. By means of new experimental and evaluational methods he unambiguously proves the primary role of dynamism of processes occurring in the dispersed stage of the stirred system, and points out that the dynamism of disintegration—coalescence and aggregation—disaggregation processes is one of the most important factors in the development of external morphological characteristics of the particle. These experimental methods also allowed the author to explain the external morphological role of the skin formed at a relatively low conversion value in suspension polymerization.
An investigation of acrylic processing aids for low molecular weight PVC
Authors: Casey William J. , Okano Kenji 
Published: December 2004

AbstractAcrylic processing aids have long been used in rigid PVC to increase fusion, decrease jetting and blushing down in blow molding, decrease parison draw down in blow molding, improve the rolling bank in calendering, improve thermoforming, and improve cell structure in foam extrusion. It has generally been thought that the specific viscosity (Nsp/c) of process aids were limited to a fairly limited narrow range. Recently, significantly higher molecular weight process aids have been developed and commercialized. Very little work though has been done with low molecular weight process aids as these products were assumed to be ineffective when compared to the commonly used products. This paper will investigate currently available products and some experimental products well above and below the Nsp/c of currently available products. The major area of investigation will be in very low to low molecular weight PVC resins and will deal with the applicability of these products in injection molding.
Compounds based on ultra‐high molecular weight PVC resins for use in automotive applications
Authors: Brookman Robert S. , Mazer Paul , Schmeyer Donald 
Published: December 2004

AbstractThis paper reviews early work done in Japan and leads into recent domestic activities reviewing the current “state of the art.” The authors present original work covering the development of elastomeric PVC compounds for interior and exterior automotive compounds. Compound variations include variations in the molecular weight of the speciality resin component, effect of plasticizer level changes, and the addition of alloying polymers. Physical characteristics such as hardness, specific gravity, torsional modulus, tensile strength, elongation, compression set, and abrasion resistance are measured and reported. Rheology of the compounds are characterized and related to processing ease and compound surface characteristics, smoothness, gloss, etc., and evaluated in light of potential automotive applications. Weatherability for use in automotive exterior trim is discussed.
Improved process control for the plastics industry
Authors: Beauregard Michael R. 
Published: December 2004

AbstractOne of the valuable tools for organizations involved in a total quality improvement effort is statistical process control (SPC). When implementing SPC in their processes, many of these organizations have equated SPC only with X & R control charts. These control charts, though important, may not be the best tool to monitor and control every process. Other charts such as an X, Rw, Rm control chart, which monitors the location of the process outpout, the instantaneous variation, and the process variation over time, may often be a better tool. This is especially true where manufacturing companies are processing materials in batches or using batches of materials such as in polymer production and molding.
Nonprofessional counselors: Revisiting selection and impact issues
Authors: Mitchell C. M. , Davidson William S. , Redner Robin , Blakely Craig , Emshoff James G. 
Published: December 2004

ConclusionIn summary, the present study suggests that selection of university undergraduate nonprofessional counselors using paper‐and‐pencil measures had little incremental validity over self‐selection and potential treatment effects. In addition, the results suggest that the training and supervision experience of nonprofessionals clearly can have different impacts on attitudes and satisfaction. In fact, students in the least intensive condition felt quite dissatisfied with their experience and themselves. There is one caveat which should be kept in mind when examining the findings of this study. First, although four of the six conditions had reasonable numbers of students (n ≤ 24), two of the conditions were comparatively small (n = 12). Often, effects were carried by the larger conditions even when the smaller conditions evidenced opposite trends. Finally, results suggest that the setting of the experience can produce different impacts. This study suggests the importance of training intensity, content, and setting — elements which have often been neglected by previous research.
Inhibition of diethyl ether degradation in Rhodococcus sp. strain DEE5151 by glutaraldehyde and ethyl vinyl ether
Authors: Kim Yong-Hak , Engesser Karl-Heinrich 
Published: December 2004

Abstract
Alkyl ether-degrading Rhodococcus sp. strain DEE5151, isolated from activated sewage sludge, has an activity for the oxidation of a variety of alkyl ethers, aralkyl ethers and dibenzyl ether. The whole cell activity for diethyl ether oxidation was effectively inhibited by 2,3-dihydrofurane, ethyl vinyl ether and glutaraldehyde. Glutaraldehyde of less than 30 μM inhibited the activity by a competitive manner with the inhibition constant, KI of 7.07 ± 1.36 μM. The inhibition type became mixed at higher glutaraldehyde concentrations &gt;30 μM, probably due to the inactivation of the cell activity by the Schiff-base formation. Structurally analogous ethyl vinyl ether inhibited the diethyl ether oxidation activity in a mixed manner with decreasing the apparent maximum oxidation rate, , and icreasing the apparent Michaelis–Menten constant, . The mixed type inhibition by ethyl vinyl ether seemed to be introduced not only by the structure similarity with diethyl ether, but also by the reactivity of the vinyl ether with cellular components in the whole cell system.
Information sharing and coordination in make‐to‐order supply chains
Authors: Sahin Funda , Robinson E. Powell 
Published: December 2004

AbstractThis research, based on our observations of an industrial vendor–manufacturer relationship, investigates the impact of information sharing and physical flow coordination in a make‐to‐order supply chain. We mathematically model and develop simulation‐based rolling schedule procedures for analyzing the manufacturer's ordering policies, transportation activities, and the vendor's manufacturing and order fulfillment processes under five alternative integration strategies. Our objective is to measure the value of information sharing and system coordination across the strategies, identify whether the source of the benefits come from information sharing or coordination, study the allocation of system benefits among channel members, and analyze the impact of environmental factors on system cost performance. The experimental results indicate a 47.58% cost reduction moving from a traditional supply chain to a fully integrated system. While information sharing reduces costs, the main economic benefit comes from coordinated decision‐making. The savings associated with system integration are not equally allocated among channel members, and vary by strategy. The procedures developed in the research provide economic insight that fosters the sharing of technological and strategic efforts.
Evaluation of postponement structures to accommodate mass customization
Authors: Su Jack C.P. , Chang Yih‐Long , Ferguson Mark 
Published: December 2004

AbstractIn order to meet increasing customer demands for more diverse product offerings, firms are revising their supply chain structures to accommodate mass customization. The revised structures often involve delaying the delivery of the products until after the customer orders arrive, termed time postponement (TP), or delaying the differentiation of the products until later production stages, termed form postponement (FP). We develop models representing possible implementations of the TP and FP structures and compare their performance in total supply chain cost and expected customer waiting times. We find that once the number of different products increases above some threshold level, the TP structure is preferred under both performance metrics.For the most general model, a numerical experiment was designed to investigate how different factors affect the performance of the TP and FP structures. Through this experiment we show that higher arrival time and process time variations make the FP structure more favorable while increases in the number of products and higher interest rates make the TP structure more favorable. We also offer guidance to managers using either structure on where to allocate resources for performance improvement. For example, to improve the customer waiting times under the FP structure, increasing the coverage of the generic component and reducing the number of products provide larger benefits than reducing the variability of the arrival and process times.
Models for Longitudinal Data with Censored Changepoints
Authors: Jackson Christopher H. , Sharples Linda D. 
Published: December 2004

SummaryIn longitudinal studies of biological markers, different individuals may have different underlying patterns of response. In some applications, a subset of individuals experiences latent events, causing an instantaneous change in the level or slope of the marker trajectory. The paper presents a general mixture of hierarchical longitudinal models for serial biomarkers. Interest centres both on the time of the event and on levels of the biomarker before and after the event. In observational studies where marker series are incomplete, the latent event can be modelled by a survival distribution. Risk factors for the occurrence of the event can be investigated by including covariates in the survival distribution. A combination of Gibbs, Metropolis–Hastings and reversible jump Markov chain Monte Carlo sampling is used to fit the models to serial measurements of forced expiratory volume from lung transplant recipients.
Principal Component Analysis of Landmarks from Reversible Images
Authors: Theobald C. M. , Glasbey C. A. , Horgan G. W. , Robinson C. D. 
Published: December 2004

Summary
We consider the use of principal component analysis to summarize the variation in labelled landmark data for images which are reversible in the sense that a mirror image may be defined for each image and the original and mirror images may be regarded as equally representative of the population. We examine the effect of including the original and mirror images on a principal component analysis based on the landmark co-ordinates. The inclusion of mirror images is found to lead to a simplified interpretation in which some components measure asymmetry in the images and the remainder depend symmetrically on pairs of co-ordinates. This is illustrated on shape variation in carrots. A second application is to the segmentation of X-ray computed tomography images of sheep to locate the inner boundary of the carcass. It is found that image boundaries can be identified more accurately by modelling them with principal components, and that including mirror images can offer a further improvement in accuracy. Similar arguments apply when a population of images is thought to be invariant under a rotation and may also be relevant when a principal component analysis is applied to descriptive statistics such as Fourier sums.
Evaluation of Trace Evidence in the Form of Multivariate Data
Authors: Aitken C. G. G. , Lucy D. 
Published: December 2004

SummaryThe evaluation of measurements on characteristics of trace evidence found at a crime scene and on a suspect is an important part of forensic science. Five methods of assessment for the value of the evidence for multivariate data are described. Two are based on significance tests and three on the evaluation of likelihood ratios. The likelihood ratio which compares the probability of the measurements on the evidence assuming a common source for the crime scene and suspect evidence with the probability of the measurements on the evidence assuming different sources for the crime scene and suspect evidence is a well-documented measure of the value of the evidence. One of the likelihood ratio approaches transforms the data to a univariate projection based on the first principal component. The other two versions of the likelihood ratio for multivariate data account for correlation among the variables and for two levels of variation: that between sources and that within sources. One version assumes that between-source variability is modelled by a multivariate normal distribution; the other version models the variability with a multivariate kernel density estimate. Results are compared from the analysis of measurements on the elemental composition of glass.
Analysis of Longitudinal Multiple-Source Binary Data Using Generalized Estimating Equations
Authors: O’Brien Liam M. , Fitzmaurice Garrett M. 
Published: December 2004

SummaryWe present a multivariate logistic regression model for the joint analysis of longitudinal multiple-source binary data. Longitudinal multiple-source binary data arise when repeated binary measurements are obtained from two or more sources, with each source providing a measure of the same underlying variable. Since the number of responses on each subject is relatively large, the empirical variance estimator performs poorly and cannot be relied on in this setting. Two methods for obtaining a parsimonious within-subject association structure are considered. An additional complication arises with estimation, since maximum likelihood estimation may not be feasible without making unrealistically strong assumptions about third- and higher order moments. To circumvent this, we propose the use of a generalized estimating equations approach. Finally, we present an analysis of multiple-informant data obtained longitudinally from a psychiatric interventional trial that motivated the model developed in the paper.