bluuebunny/crossref_metadata_2025_split huggingface dataset:
The use of helium gas to reduce beam scattering in high vapour pressure scanning electron microscopy applications
Authors: Stowe S. J. , Robinson V. N. E. 
Published: June 2010

AbstractBoth image quality and the accuracy of x‐ray analysis invariable pressure scanning electron microscopes (VPSEMs) are often limited by the spread of the primary electronbeam due to scattering by the introduced gas. The degree of electron scattering depends partly on the atomic number Z of the gas, and the use of a low Z gas such as helium should reduce beam scattering and enhance image quality. Using anuncoated test sample of copper iron sulphide inclusions in calcium fluorite, we show that the reduction in beam scatter produced by helium is more than sufficient to compensate for its reduced efficiency of charge neutralisation. The relative insensitivity to pressure of x‐ray measurements in a helium atmosphere compared with air, and the consequent ability to work over a wider range of working distances, pressures, and voltages, make helium potentially the gas of choice for many routine VPSEM applications.
Assessment of stress fiber orientation during healing of radial keratotomy wounds using confocal microscopy
Authors: Petroll W. Matthew , Cavanagh H. Dwight , Jester James V. 
Published: June 2010

AbstractRadial keratotomy (RK) is a refractive surgical procedure in which partial thickness incisions are made in the cornea in order to alter its shape. Previous studies suggest that RK wounds undergo changes in wound gape in response to the in growth of myofibroblasts which mediate subsequent wound contraction and may modulate changes in corneal curvature seen after RK. A recent quantitative analysis of f‐actin organization in full‐thickness incisional wounds in the rabbit demonstrated that microfilament bundles (stress fibers) present in myofibroblasts alignparallel to the long axis of the wound during wound contraction. To investigate whether the same pattern of alignment occurs after RK, a similar analysis of f‐actin organization was undertaken using the cat RK model. Radial keratotomy wounds were studied from 10 to 28 days after surgery using en block staining with fluorescein isothiocyanate (FITC) phalloidin, and three‐dimensional (3‐D) datasets (z‐series of en face optical sections) were collected using laser confocal microscopy at various regions within the wound. In addition, conventional en face sections were double‐labeled using combinations of phalloidin and antibodies to fibronectin and α5β1 integrin. Myofibroblast ingrowth started in the bottom of the wound and progressed anteriorly. At 10 to 14 days, f‐actin was predominantly distributed in long, thick bundles (stress fibers) within the wound. These fibers appeared to be randomly oriented anteriorly, but became progressively more aligned with the long axis of the wound posteriorly. At 21 days, the stress fibers were predominantly oriented parallel to the long axis of the wound at all levels. F‐actin, fibronectin and integrin were coalignedatboththe 14 and 21 day time points. Since the majority of wound closure occurs between 14 and 28 days after surgery, we conclude that parallel alignment of the actin filament‐fibronectin‐integrin assembly in the cat RK model is associated with wound contraction.
The detection of low‐intensity peaks in energy dispersive x‐ray spectra from particles
Authors: Small John. A. 
Published: June 2010

AbstractA critical step in the processing of energy dispersive (EDS) x‐ray spectra from the automated scanning electron microscopy (ASEM) analysis of particles is the detection and identification of elemental peaks. Since there are often several hundred to several thousand spectra for each ASEM analysis, it is important that this step operate rapidly and with a minimum of interaction between analyst and the program. For peaks with large peak‐to‐background (P/B) ratios, most peak‐find or peak‐fitting methods do a reasonable job even when the spectra have low signal‐to‐noise (S/N) ratios. The detection of peaks with small P/B ratios is much more problematical. Peak identification and fitting procedures may not work well on low‐intensity peaks, particularly in spectra with low S/N ratios. In this study, three procedures for identifying x‐ray peaks, with small P/B ratios in spectra with varying S/N ratios, were evaluated. The first procedure was the identification of peaks by human analysts. The results from the analysts were then used to set a benchmark for the performance of two computer‐based procedures that included three different qualitative peak identification methods, and one quantitative analysis procedure. The success of the qualitative methods in finding small peaks varied widely. In general, the quantitative analysis procedure performed as well as the best human analysts and was better than the qualitative methods.
Using fractal dimensions to characterize atomic force microscope images of epoxy resin fracture surfaces
Authors: Joseph Tom , Chen Zheng , Mecholsky J. J. , Beatty Charles 
Published: June 2010

AbstractAtomic force microscopy was used to obtain images of the fracture surface of a tri‐ethylene‐tetramine and 4,4 (methyl thylidene) epoxy resin. Images were obtained in the mirror, mist, and hackle regions of each sample. Fractal dimensions were calculated from the images using the box dimension and contour analysis method. The box dimension fractal dimension increment for all regions on the fracture surfaces were determined to average 0.26 ± 0.06 and the contour analysis fractal dimension increment were determined to average 0.46 ± 0.05. The box dimension technique is shown to provide the “true” fractal dimension of the surface. The fractal dimension measurements for all three regions indicated that the fracture surface was self‐affine and possibly self‐similar.
Measurement of crystal parameters on backscatter kikuchi diffraction patterns
Authors: Baba‐Kishi K. Z. 
Published: June 2010

AbstractElectron backscatter Kikuchi diffraction patterns (BKDPs) recorded in the scanning electron microscope (SEM) require measurements on the plane of the photographic film or on the recording screen. The parameters that require measurements are the equivalent electron source point on the pattern, or pattern centre, specimen‐to‐film distance, true interzonal angles, true interplanar angles, Bragg angles, and interplanar spacing. In this paper, the geometry and the methods of calculation of these parameters on BKDPs recorded directly on film are described in detail. The methods described are suitable for practical purposes, providing speed of calculation but limited accuracy. The inherent factors that limit the accuracy of any measurements on BKDPs are the limitations of the gnomonic projection, resulting in projected distortions in Kikuchi bands and diffuseness of Kikuchi band edges originating from inelastic scattering of electrons. The methods described are applied to crystallographic analysis of BKDPs recorded from silicon and polycrystalline copper.
Image comparisons of snow and ice crystals photographed by light (video) microscopy and low‐temperature scanning electron microscopy
Authors: Wergin William P. , Erbe Eric F. , Rango Albert 
Published: June 2010

AbstractLight (video) microscopy and low‐temperature scanning electron microscopy (SEM) were used to examine and record images of identical precipitated and metamorphosed snow crystals as well as glacial ice grains. Collection procedures enabled numerous samples from distant locations to be shipped to a laboratory for storage and/or observation. The frozen samples could be imaged with a video microscope in the laboratory at ambient temperatures or with the low‐temperature SEM. Stereo images obtained by video microscopy or low‐temperature SEM greatly increased the ease of structural interpretations. The preparation procedures that were used for low‐temperature SEM did not result in sublimation or melting. However, this technique did provide far greater resolution and depth of focus over that of the video microscope. The advantage of resolution was especially evident when examining the small particles associated with rime and graupel (snow crystals encumbered with frozen water droplets), whereas the greater depth of focus provided clearer photographs of large crystals such as depth hoar, and ice. Because the SEM images contained only surface information while the video images were frequently confounded by surface and internal information, the SEM images also clarified the structural features of depth hoar crystals and ice grains. Low‐temperature SEM appears to have considerable promise for future investigations of snow and ice.
A robust focusing and astigmatism correction method for the scanning electron microscope—Part II: Autocorrelation‐based coarse focusing method
Authors: Ong K. H. , Phang J. C. H. , Thong J. T. L. 
Published: June 2010

AbstractThis paper describes the development of a new coarse focusing algorithm for the scanning electron microscope (SEM). The algorithm is based on a new focus parameter that has been developed for quantifying the sharpness of an image. This parameter is found to be more robust to noise compared with other conventional focus parameters. A peak detection technique is also incorporated to shorten the number of iterations needed for the coarse focusing. Results show that the coarse focusing algorithm is able to bring a defocused and astigmatic image to either the best focus, the upper line focus, or the lower line focus in fewer iterations compared with the conventional approach in which the full focus range is searched.
A robust focusing and astigmatism correction method for the scanning electron microscope—Part III: An improved technique
Authors: Ong K. H. , Phang J. C. H. , Thong J. T. L. 
Published: June 2010

AbstractAs described in a previous work, a new technique has been developed to perform automatic focusing and astigmatism correction on any general scanning electron microscope (SEM) sample ranging from gold‐on‐carbon to integrated circuit (IC) tracks. In this work, various improvements made to this technique are reported. They include the implementation of direct control of the SEM and the development of three new algorithms, namely the adaptive fast Fourier transform (FFT) algorithm, the coarse focusing algorithm, and the fine focusing algorithm. Direct control reduces the communication time with the SEM while the three new algorithms are integrated with the existing technique to make it even more robust to noise and to extend it to correct images with any degree of defocus and astigmatism. The enhanced focusing and astigmatism correction algorithm is able to perform the correction in a shorter time while maintaining the accuracy of the original algorithm even under noisy conditions.
Peculiarities of diamonds formed in alkaline carbonate‐carbon melts at pressures of 8–10 GPA: Scanning electron microscopy and cathodoluminescence data
Authors: Litvin Y. A. , Chudinovskikh L. T. , Saparin G. V. , Obyden S. K. , Chukichev M. V. , Vavilov V. S. 
Published: June 2010

AbstractDiamond crystallization with both spontaneous and seeded nucleation was realized in the system Na2Mg(CO3)2‐K2Mg(CO3)2‐C (graphite) at 8–10 GPa and 1700–1800°C. The crystallization products were transparent colorless diamond single crystals of octahedral habit up to 100–150 μm in size. Scanning electron microscopy (SEM) showed that the growing diamond material was precipitated on both octahedral {111} and cubic { 100 } faces of synthetic and natural diamond seed crystals by layers of octahedral orientation, much like the growth of the natural diamond. The physicochemical conditions for diamond crystallization are interpreted as a crystal growth from carbon solutions in alkaline‐carbonate melts. Color cathodoluminescence scanning electron microscopy (CCL‐SEM) and cathodoluminescence (CL) spectroscopy studies suggested specific peculiarities of the synthetic “carbonate‐carbon”(CC) diamonds resembling natural crystals in comparison with diamonds produced by metal‐carbon (MC) synthesis. The main feature of the CC product is the lack, for both spontaneous and seed stimulated diamonds, of surface color cathodoluminescence as in the case for natural diamonds with lower concentrations of nitrogen impurity (type II). The CL spectra of the CC diamonds showed the simultaneous luminescent three‐band system ‐ H3, 575 nm, and a weak blue A‐band ‐ the H3 band structure of which resembles that of natural diamonds of type IIa.
Structural characteristics of stored black beans (Phaseolus vulgaris L.)
Authors: De J. Berrios Jose , Swanson Barry G. , Cheong W. Adeline 
Published: June 2010

AbstractScanning electron microscopy (SEM) was used to study and compare the structural characteristics of black beans after 2 years of storage under ambient conditions (AC) and refrigerated hypobaric conditions (RHC). The exterior surface of the seed coats of the black beans were covered with small flake‐like materials randomly clustered together. The hilar regions of black beans stored under either AC or RHC were similar, and the “linea lucida” exhibited well defined double palisade cell layers in both bean treatments. Cross sections of the seed coats revealed that the parenchymal cell layers of the beans stored under AC were disrupted and frequently exhibited large intercellular spaces between the cell layers. The parenchymal cell layers of the beans stored under RHC demonstrated little disruption of the cell layers, with only occasional intercellular spaces between the cell layers. Cotyledon cross sections of blackbeans showed that the cotyledon cells of the beans stored under RHC exhibited many large intercellular spaces characteristic of normal beans. Conversely, cotyledon cross sections of the beans stored under AC exhibited cotyledon cells with few small intercellular spaces characteristic of hard‐to‐cook beans.
Mc3D: A three‐dimensional Monte Carlo system simulating image contrast in surface analytical scanning electron microscopy I—Object‐oriented software design and tests
Authors: Yan H. , Gomati M. M. El , Chu D. P. , Dowsett M. G. , Prutton M. , Wilkinson D. K. 
Published: June 2010

AbstractThe main features of a three‐dimensional (3‐D) Monte Carlo software system (Mc3D), designed for the simulation of electron scattering and image contrast in a scanning electron microscope, are reported. Before simulating electron trajectories in the sample, impingement of the incident electron beam is described by introducing the idea of a virtual scan path in 3‐D space. A general and concise algorithm is given for simulating the intersection of electron trajectories leaving the sample onto multidetector entrance apertures distributed in 3‐D space. By optimising the object‐oriented design in conjunction with the use of a process‐oriented and data‐oriented code structure, Mc3D is capable of simulating microscopic analysis of a sample with a 3‐D geometry or structure that can be expressed with formulae. Three examples of the use of Mc3D are given. The first is for linescans across a block of SiO2 on top of a Si substrate; the second is for a stripe of SiO2 embedded in a Si substrate. Finally, the simulation of Auger linescans across an Au overlay on Si is compared with experimental results. The relationships between experimental linescans and the true beam impact positions on the sample are revealed through the virtual scan path. An edge effect, parallel‐edge enhancement, is predicted when the incident electron beam size, the distance of impact position to the terrace edge, and the inelastic mean free path of the Auger electron from a given element are comparable, and the linescan is parallel to the terrace edge. All three examples demonstrate the sensitivity of image contrast to the disposition of the sample with respect to the electron column and the detector position.
Performance of a tilt‐compensating tube scanner in atomic force microscopy
Authors: Hannss M. , Naumann W. , Anton R. 
Published: June 2010

AbstractA tube scanner is constructed which avoids tilting of the sample surface when areas at some distance off the tube axis are scanned. Such tilt occurs with conventional piezo tubes, causes distorted vertical scaling, and limits the field of view to a few μm. These problems are partly overcome with a new design, which also uses a single tube, but with eight‐segmented electrodes. It can be thought of being constructed of two four‐segmented, conventional tubes, with the x‐ and y‐sections in the two parts being connected crosswise. While no additional voltage supply is needed, the tube is forming an s‐like shape, such that the bending of one half of the tube is compensated by a similar bending, but in the opposite direction, of the other half. Moreover, the displacement of the sample surface in z‐direction can be compensated quantitatively by suitable compression or dilatation of the tube, which can always be calculated from the known lateral displacement of the axis. The performance of this scanner is demonstrated on steps of a calibration replica.
Photon scanning tunneling microscope, now and in the future
Authors: Wu Shifa 
Published: June 2010

AbstractThe concept of photon tunneling and the principle of the photon scanning tunneling microscope (PSTM) are described. The history of the PSTM and its development in China are reviewed. The principal problem in the recent development of the PSTM, together with its solution, is discussed. The distinguishing features and the future of the PSTM are described.
The fourier optics of near‐field microscopy
Authors: Sheppard C. J. R. , Fatemi H. , Gu Min 
Published: June 2010

AbstractMany different optical schemes for achieving super‐resolution by probing a near field have been proposed and one of the most important of these is the use of a tapered optical fibre probe. Plain optical fibre probes have also been used for microscopy. The Fourier optics behind these various methods are considered, contrast mechanisms discussed, and the concept of the transfer function for an evanescent field developed.
Observations of snow crystals using low‐temperature scanning electron microscopy
Authors: Wergin William P. , Rango Albert , Erbe Eric F. 
Published: June 2010

AbstractLow‐temperature scanning electron microscopy (SEM) was used to observe precipitation particles commonly known as “snowflakes.” The snowflakes were collected in Beltsville, Maryland, at temperatures ranging from −6° to +1°C, mounted on SEM stubs, frozen in liquid nitrogen (LN2), and then transferred to a cryosystem mounted on a field‐emission SEM. Neither sputter coating with platinum nor irradiation by the electron beam affected their delicate fine structure. SEM observations revealed that snowflakes consisted of aggregations of snow crystals that occurred as hexagonal plates, prismatic columns, needles, and dendrites. In some cases, the snow crystals contained minute surface structures that consisted of rime, microdroplets, short prismatic columns, and amorphous films. Snow crystals from wet snow, which were collected at temperatures of 0° and +1°C, exhibited varying degrees of metamorphism or melting. The discrete crystalline faces and their sharp intersecting angles were gradually replaced by sinuous surfaces that tended to exhibit more spherical shapes. This study indicates that low‐temperature SEM is a valuable technique for studying the formation and metamorphosis of snow crystals. The results suggest that combining low‐temperature SEM and x‐ray analysis could also provide qualitative elemental information on the nucleation particles of snow crystals as well as on the composition of acid snow.
Metallurgical interactions at the contacts GaAs interface
Authors: Cole M. W. , Han W. Y. , Casas L. M. , Eckart D. W. , Jones K. A. 
Published: June 2010

AbstractInterface morphology, phase composition, and elemental diffusion of Pt/Ti/Ge/Pd ohmic contacts to both n and p+‐GaAs have been investigated as a function of annealing temperature. Structural and chemical results were correlated with specific contact resistances (ρc) measured for each thermal treatment. Annealing at 450°C yielded the lowest ρc, ∼6.4 × 10−7Ω‐cm2. The interface was observed to be smooth and abrupt. Two interface phases were detected; a primary phase, PdGe, and a secondary, Ga‐rich Pd‐Ga‐As ternary phase. The presence of this ternary phase was found to be critical to contact formation on n‐GaAs. The Ti and Pt layers remained pristine. Annealing at 550°C resulted in a slightly higher ρc, ∼2.1 × 10−6Ω‐cm2. There was significant elemental diffusion within the contact metal and minor diffusion into the GaAs substrate. The interface possessed limited areas of spiking with uniform composition. Annealing at 600°C proved to have a detrimental effect on the ρc, ∼10−4Ω‐cm2. This electrical degradation was accompanied by strong chemical intermixing between the contact and substrate, resulting in a continuous nonplanar interface with deep multiphase protrusions.
A semiautomated image analysis procedure for the quantification of dental microwear II
Authors: Ungar Peter S. 
Published: June 2010

AbstractPaleontologists often examine microscopic scratches and pits that form on teeth for indications of the diets of past animals. Most researchers count and measure scratches and pits from photomicrographs to identify microwear patterns for comparison among samples. This paper describes an affordable, available semiautomated image analysis procedure for microwear quantification. An image is downloaded from a scanning electron microscope frame buffer to a microcomputer, and the user identifies microwear features with a mouse‐driven pointer. Microwear feature density, dimensions, and orientations are then computed and stored as ASCII files for subsequent data analysis.
A database on electron‐solid interactions
Authors: Joy David C. 
Published: June 2010

AbstractMonte Carlo modeling of electron‐solid interactions requires a detailed and accurate supply of experimental data on which to base its physics and against which to test its predictions. To meet this need, a collection of data—comprising measurements of secondary and backscattered electron yields, electron stopping powers, and x‐ray ionization cross sections, as a function of energy—has been assembled from published sources. The quality and quantity of the compilation varies widely, with little or no data being available for the majority of elements in the periodic table, while results for complex materials of current technologic interest are also almost nonexistent. To meet the needs of Monte Carlo simulation in areas such as dimensional metrology or microanalysis, a program of systematic measurements is required.