bluuebunny/crossref_metadata_2025_split huggingface dataset:
Confocal laser scanning photoelasticity: Improvement of precision for quantitative photoelastic studies on model composite materials
Authors: Lütze S. 
Published: June 2010

AbstractPhotoelastic studies on model composite materials with different model materials and load applications have been performed to understand the various failure mechanisms in real composites. Optical investigations of the stress fields have been conducted using a polarising, confocal laser scanning microscope (Zeiss LSM 410, Zeiss, Jena, Germany), where the phase of the isochromatic fringes has been determined from the data. Two different methods are presented to improve the quantitative evaluation of the isochromatic phase. By combining manual and automatic evaluation of fringes, even samples with a high stress gradient can be analysed. A method has been developed for the correction of the integrated through‐thickness birefringence, in the case of rotationally symmetric stress fields. This technique permits the inverse calculation of stress at various depths in the sample, in particular in the case of a nonlinear dependence of optical birefringence on stress. Both methods are demonstrated in the evaluation of tensile tests on multifibre model samples (glass fibres in polycarbonate).
Investigation of human hair fibers using lateral force microscopy
Authors: McMullen Roger L. , Kelty Stephen P. 
Published: June 2010

AbstractAtomic force microscopy (AFM) and lateral force microscopy (LFM) were used to investigate the morphologic and surface changes associated with various surface modifications to human hair. These included extraction with a series of solvents, bleaching, and treatment with a cationic copolymer. The study assessed the ability of these techniques to distinguish the changes in surface properties, including morphology and friction coefficient, as manifested in changes brought about by the indicated surface modifications. While topographic morphology can easily be investigated with contact AFM, LFM offers an additional tool for probing the surface distribution of oils and waxes. The removal of surface lipids from the fiber surface was accomplished using soxhlet extraction with t‐butanol and n‐hexane, while the free internal lipids (within the fiber structure) were removed by extraction with a mixture of chloroform and methanol (70:30, v/v). In addition, the surface of hair was modified with the cationic polymer, co(vinyl pyrrolidone‐methacry lamidopropyl trimethylam‐monium chloride [PVP/MAPTAC]), and its distribution on the surface was monitored. Ambient AFM and LFM studies of surface modified and native fibers clearly indicate that when investigated as a function of tip loading force, the different modifications result in changes of the friction coefficient, which increase in this order: native, bleached, solvent extracted, and polymer‐treated hair. Friction images show surface variations that are interpreted as areas of varying lipid film coverage. In addition, topographic images of the fibers show the presence of small pores, which become increasingly prevalent upon solvent extraction.
High‐resolution analysis of engineered type I collagen nanofibers by electron microscopy
Authors: Huang Lei , Apkarian Robert P. , Chaikof Elliot L. 
Published: June 2010

AbstractCollagen nanofibers were generated at ambient temperature and pressure by electrospinning a 1wt% solution of type I collagen and polyethylene oxide. Products were imaged with high‐resolution scanning electron microscopy (HRSEM) at medium (∼30,000 ×) and high magnifications (∼100,000 ×) and with transmission electron microscopy (TEM). The capacity to produce collagen nanofibers may lead to the generation of extracellular matrix‐based fabrics with applications in the fields of wound healing and tissue engineering.
Convolution and correlation: A case study of scanning imaging and analysis systems
Authors: Yan H. , Joy D. , Lei M. 
Published: June 2010

AbstractThe relationship between convolution/correlation operation and the data acquisition process of the scanning microscope and spectrometer families is analyzed. It is shown that a coordinate or event sensitive detector, and the intrinsic or extrinsic property of the specimen response, are two important factors in distinguishing the data acquisition mode of such systems. Four types of convolution‐ and correlation‐based modes are extracted to illuminate the physical characteristics of scanning imaging and analysis systems by focusing on the probe, specimen, detector, and their relationships. Criteria for identifying these modes are explored. In addition, the physical meanings of general existing coefficients between the independent variables of convolution and correlation are investigated.
Three‐dimensional reconstruction of microstructures in gibbsite using charge contrast images
Authors: Baroni Travis C. , Lincoln Frank J. , Griffin Brendan J. , Cornell John B. , Roach Gerald I. D. 
Published: June 2010

AbstractAn iterative process of serial sectioning and charge contrast imaging has been applied to gibbsite particles embedded in epoxy resin. The features observed in the two‐dimensional sections have been reconstructed into three‐dimensional (3‐D) objects, so that the volumetric relationships in the microstructure are visualised. The 3‐D objects confirm that the image detail present in charge contrast images of gibbsite is related to the microstructure and the processes occurring during the crystallisation of gibbsite. Speculative explanations for what these microstructures may represent are presented.
An empirical energy loss equation of electrons
Authors: Zhenyu Tan , Yancai He 
Published: June 2010

AbstractA modified Love‐Cox‐Scott (1978) equation of electron energy loss has been suggested. The stopping powers predicted by the modified Love‐Cox‐Scott equation are compared with those by the Tung et al. (1979) model, the Joy and Luo (1989) equation, and the experimental data given in database of Joy at: http://web.ukt.edu/∼scrutk. In the energy range of E0⩽5keV, the Monte Carlo simulations of the electron scattering in Al, Ag, and Au have been performed, applying the Mott cross section for elastic scattering and the modified Love‐Cox‐Scott equation (1978) and the equations by Love et al. (1978) and Joy and Luo (1989), respectively, for the inelastic scattering. The calculated results on the backscattering coefficients, the energy distributions of the backscattered electrons, and the energy dissipation of the electron based on the three equations are compared.
Cosmetic assessment of the human hair by confocal microscopy
Authors: Hadjur Christophe , Daty Gérard , Madry Geneviève , Corcuff Pierre 
Published: June 2010

AbstractThe optical sectioning property of the confocal microscope offers a breakthrough from the classic observation of the hair in a scanning electron microscope (SEM). Confocal microscopy requires minimal sampling preparation, and the hair can be observed in its natural environment with less damage than by other microscopic methods such as SEM. While used in the reflection mode, the true morphology of the cuticle and the various exogenous deposits at the surface can be identified and quantified. This relatively noninvasive, nondestructive technique is routinely used by us to monitor the efficiency of cleansing shampoos, to assess the homogeneity of layering polymers, and to evaluate the changes they induce in the optical properties of the hair surface in terms of opacity, transparency, and brilliancy. A second important field of investigation uses the fluorescence channel which reveals the internal structure of the hair. Fluorescent probes (rhodamine and its derivatives) demonstrate the routes of penetration and outline the geometry of cortical cells and of the medulla according to their lipophilic or hydrophilic properties. A volume rendering of a hair cylinder provides a better understanding of the interrelationships between cuticle cells, cortical cells, and the medullar channel. This recent technology is becoming an invaluable tool for the cosmetic assessment of the hair.
Application of the scatter diagram technique to the scanning electron microscope: Preliminary results from diamond
Authors: Patat J. M. , Cazaux J. , Lehuede P. , Durand O. 
Published: June 2010

AbstractUsing primary beam energies E0 ranging from 0.2 to 15 keV and an in‐lens detector, a series of images of the same region of an artificial microstructured diamond sample have been acquired in scanning electron microscopy. Next, the images were analysed by using a scatter diagram technique to underline the topographic contrast change and contrast reversal. The results obtained from 0.5 to 15 keV are discussed with the help of an expression derived from the constant loss model for the secondary electron yield δ of diamond, but including the respective roles of the angle of incidence, i, and of the angle of detection, α. More surprising is the quality of images obtained at a beam energy as low as 0.2 keV, and more difficult to explain is the significant contrast change between 0.2 keV and 0.5 keV. For the first time, scatter diagrams are used as a diagnostic tool in scanning electron microscopy, and after some improvements it is hoped that the experimental approach followed here may lead to quantitative estimates of the local tilts of a specimen surface.
Tracers in vascular casting resins enhance backscattering brightness
Authors: Schraufnagel Dean E. , Ganesan Dhanalakshmi P. 
Published: June 2010

AbstractStudying cast microvasculature with scanning electron microscopy has expanded our knowledge of many circulations, but need arises to determine the blood source of vascular beds that are supplied by two circulations. One way to do this is to mark the casting resin by adding a tracer compound that can be detected in the scanning electron microscope. A potential method of distinguishing different substances is to detect the backscattered electrons that are emitted from the tracer if the tracer is a heavier element, because heavier elements backscatter more electrons. To explore different tracers, we tested lead, titanium, iron, osmium, and uranium as solutions of different polarity and powders. The tracers were added to 1 ml of methyl methacrylate in log concentrations. Shrinkage, hardness, cast quality, and change in brightness from the tracer were compared with multivariate analysis at scanning electron microscopic working distances of 15 and 39 mm on carbon‐coated and uncoated specimens. Several concentrations caused sedimentation of the tracer and prevented the resin from solidifying. Tetraethyl lead shortened the hardening time; uranyl acetate and osmium tetroxide prolonged it. Most tracers decreased shrinkage. When lead citrate and Reynolds solutions were removed, the brightness correlated with increasing atomic number, concentration of the tracer, and mean atomic number of the specimen (p <0.0001). The substances that increased contrast most were tetraethyl lead and uranium. Backscattering electron detection can distinguish methacrylate casts that have small amounts of heavier elements added to them, but an optimal tracer has not yet been established.
Error rates in dental microwear quantification using scanning electron microscopy
Authors: Grine F. E. , Ungar P. S. , Teaford M. F. 
Published: June 2010

AbstractThere is a degree of correlation between dietary habits and dental microwear in extant primates, and this has enabled inferences to be made about prehistoric diets. Several techniques have been used to quantify microwear, but the comparability of results derived from each has not been demonstrated. Moreover, neither intra‐ nor interobserver error rates in microwear quantification have been documented to date. We here assess intra‐ and interobserver error using Microware 4.0, and evaluate intertechnique comparability using the three methods that have been most widely employed in the field. This study documents an overall intraobserver error rate of about 7%, and an overall interobserver error rate of some 9%. Both intra‐and interobserver error appears to be influenced substantially by the nature of the micrograph being measured. In no instance did the results obtained by different observers using Microware 4.0 differ significantly, and there was a reasonable degree of interobserver consistency in the rank ordering of micrographs in relation to any given parameter. The results obtained through the use of different quantitative techniques differed significantly, with an overall intertechnique error rate of approximately 19%. Several variables, including differences in magnification factor, scanning electron microscope kV settings, and specimendetector relationships undoubtedly contribute to the differences among the three methods, but we were not able to assess their relative importance. Microwear quantification permits distinctions between broad dietary categories, but the margin of intra‐ and interobserver error should be taken into account when defining pattern differences between populations (or species) or when documenting seaseasonally mitigated differences within a taxon. In view of the error introduced by the use of different methods, we suggest that a consistent technique, such as offered by the Microware software package, be adopted by current researchers to establish a common microwear database.
Scanning electron microscopy observation of the substructural evolution of aluminium alloys during cold rolling and partial annealing
Authors: Schouwenaars Rafael , Cerrud Sara , Ortiz Armando 
Published: June 2010

AbstractClassical etching techniques for revealing cold deformation and partial recrystallisation in metals have been optimised for optical microscopy, which is limited by its resolution. Detailed studies of the mechanisms involved in recovery and recrystallisation during heat treatment are generally made by transmission electron microscopy. The limitation of this technique, with a few exceptions, is its small field of view and the small fraction of the sample available for inspection. The present article departs from the statement that etching, which is a surface alteration technique, must have effects that are detectable by scanning electron microscope (SEM). It was found that carefully adapted polishing and etching procedures allow for substructural investigations by SEM, resulting in various advantages compared with both optical microscopy and TEM.
High‐temperature electron backscatter diffraction and scanning electron microscopy imaging techniques: In‐situ investigations of dynamic processes
Authors: Seward G. G. E. , Prior D. J. , Wheeler J. , Celotto S. , Halliday D. J. M. , Paden R. S. , Tye M. R. 
Published: June 2010

AbstractIn‐situ heating experiments have been conducted at temperatures of approximately 1200 K utilising a new design of scanning electron microscope, the Cam‐Scan X500. The X500 has been designed to optimise the potential for electron backscatter diffraction (EBSD) analysis with concomitant in‐situ heating experimentation. Features of the new design include an inclined field emission gun (FEG) column, which affords the EBSD geometrical requirement of a high (typically 160°) angle between the incoming electron beam and specimen surface, but avoids complications in heating‐stage design and operation by maintaining it in a horizontal orientation. Our studies have found that secondary electron and orientation contrast imaging has been possible for a variety of specimen materials up to a temperature of at least 900°C, without significant degradation of imaging quality. Electron backscatter diffraction patterns have been acquired at temperatures of at least 900°C and are of sufficient quality to allow automated data collection. Automated EBSD maps have been produced at temperatures between 200°C and 700°C in aluminium, brass, nickel, steel, quartz, and calcite, and even at temperatures >890°C in pure titanium. The combination of scanning electron microscope imaging techniques and EBSD analysis with high‐temperature in‐situ experiments is a powerful tool for the observation of dynamic crystallographic and microstructural processes in metals, semiconductor materials, and ceramics.
Limitations on optical sectioning in live‐cell confocal microscopy
Authors: Pawley James B. 
Published: June 2010

AbstractIn three‐dimensional (3‐D) live‐cell microscopy, it has been common to treat cells as having a constant refractive index (RI). Although the variations in RI associated with the nucleus and other organelles were recognized from phase‐ and differential interference contrast (DIC) images, it was assumed that they were small and would not affect 3‐D fluorescence images obtained using widefield/deconvolution, confocal of multiphoton imaging. This paper makes clear that this confidence was misplaced. Confocal images made using backscattered light (BSL) to image the flat, glass/water interfaces above and below living microscope specimens should reveal these structures as flat and featureless. That the image of the interface on the far side of the cells is neither flat nor featureless indicates that the “optical section” surface can be profoundly distorted by the RI irregularities associated with the presence of nuclei and other subcellar structures. This observation calls into question the reliability of images made using any of the current methods for performing 3‐D light microscopy of living cells.
A monte carlo study of the thickness determination of ultra‐thin films
Authors: Zhenyu Tan , Yueyuan Xia 
Published: June 2010

AbstractA Monte Carlo method is utilized to simulate the energy spectra for low‐energy electron backscattered from different thin films deposited on different bulk substrates. A method of thickness determination for ultra‐thin films is presented, which is obtained from the analysis of the basic characteristics of the energy spectra of backscattered electrons. This method is predicted to be particularly suitable for determining the thickness of ultra‐thin films, and to be useful for both cases of light film on heavy substrate and heavy film on light substrate. The thickness resolution is estimated to be as high as subnanometer scale, provided the resolution of the electron energy spectrometer used to be high enough.
Monte Carlo analysis of the detection of clay occlusion of respirable quartz particles using multiple voltage scanning electron microscopy
Authors: Hnizdo V. , Wallace W. E. 
Published: June 2010

AbstractThe electron incident‐energy dependence of the relative intensities of Al and Si x‐rays produced in a respirable‐sized quartz particle by scanning electron microscopy is sensitive to the inhomogeneity of the distribution of Al and Si in the particle. Realistic Monte Carlo calculations of this energy dependence validate the proposal to use this effect for the detection of particles in which an aluminosilicate coating occludes the surface of a silica core.
The two‐dimensional and three‐dimensional processing of images provided by conventional microscopes
Authors: Martišek Dalibor 
Published: June 2010

AbstractIn this paper, I present an interesting processing method of microscopic images. High‐pass type filters are generally used for image focusing. They enhance the high spatial frequencies. They are, however, efficient only in cases when the picture is not sharp because of the low contrast on high frequencies (for example in a TV picture). These filters, are not appropriate if the lack of sharpness has been caused by other factors. In this case, it is not possible to construct a three‐dimensional model of the observed object. Better results and a three‐dimensional model can be obtained by applying the following theory. As part of this paper, an original program based on this theory is described.
Optimisation of the environmental scanning electron microscope for observation of drying of matt water‐based lacquers
Authors: Royall C. P. , Donald A. M. 
Published: June 2010

AbstractEnvironmental scanning electron microscopy (ESEM) modifies conventional SEM through the use of a partial gas pressure in the microscope specimen chamber. Like conventional SEM, it has the resolution to image structure on the submicron lengthscale, but can also tolerate hydrated specimens if water vapour is used in the specimen chamber. This ability to image aqueous specimens leaves ESEM uniquely placed to study in situ drying in polymer latexes. However, there are two key practical difficulties associated with in situ drying. First, the size of the latex particles: larger latex particles are typically around 500 nm in diameter. Although ESEM can resolve structure on this lengthscale without difficulty, the magnification required results in radiation damage of the specimen due to the electron beam. This means that a given region can be imaged only once during film formation, so the evolution of particular features cannot be followed. Second, the change from ambient temperature and pressure to the ESEM conditions of 7°C and 7.5 torr (100 Pa) can subject the specimen to a very high evaporation rate, which can disrupt film formation. The inclusion of a drsitionop of water in the specimen chamber is shown largely to alleviate this, enabling successful imaging of film formation in the lacquer. Instead of the polymer latex itself, this work concentrates on a matting lacquer with silica inclusions. The silica matting agent particles are 1‐10 μm in size, allowing for a lower magnification to be used, massively reducing specimen damage. Furthermore, the contrast during drying is much enhanced in the presence of silica. The images reveal the silica as bright regions against a darker background of polymer and water. Film formation shows the transition from a uniform, featureless aqueous solution to a polymer film with silica particles present on the surface. The appearance of individual silica particles can be followed. The particles are generally revealed quite early, after a few minutes of drying time. As film formation progresses, these same particles appear larger and more distinct. Few new particles are revealed at longer film formation times.
The biomass dynamics of cyanobacteria in an annual cycle determined by confocal laser scanning microscopy
Authors: Solé A. , Gaju N. , Esteve I. 
Published: June 2010

AbstractWe recently published a method for estimating cyanobacteria biomass in delta microbial mats from the Ebro river using confocal laser scanning microscopy (CLSM). The present paper uses this method for identifying different groups of cyanobacteria and for determining their biomass dynamics. Microcoleus chthonoplastes and the Lyngbya‐Oscillatoria were the most important contributors to the cyanobacterial biomass throughout the study. Biomass values ranged from 1.29 to 6.55 mgC/cm2 sediment for Microcoleus chthonoplastes, and from 128 μgC/cm2 to 3.16 mgC/cm2 sediment for Lyngbya‐Oscillatoria. This technique is useful for determining biomass and for studying filamentous cyanobacteria as well as ramified eukaryotic cells. Confocal serial sections through the samples can be obtained. Two‐dimensional images from the samples can be used to calculate the biomass of individual cells.
Microstructure of monoplacophora (mollusca) shell examined by low‐voltage field emission scanning electron and atomic force microscopy
Authors: Cruz Renato , Weissmüller Gilberto , Farina Marcos 
Published: June 2010

AbstractThe shell of Micropilina arntzi (Mollusca: Monoplacophora), a primitive molluscan class, was examined by using field emission scanning electron microscopy (FESEM) at low voltage and atomic force microscopy (AFM). The use of these two techniques allowed the observation of fine details of Micropilina arntzi shell and contributed to bring new features concerning the study of molluscan shell microtexture. Imaging with low‐voltage FESEM provided well‐defined edge contours of shell structures, while analyzing the sample with AFM gave information about the step height of stacked internal structures as well as the dimension of the particles present in their surface at a nanometric level. The shell microstructure of Monoplacophora species presents different patterns and may be a taxonomic implication in the systematic studies of the group.