bluuebunny/crossref_metadata_2025_split huggingface dataset:
Computation of polar angle of collisions from partial elastic mott cross‐sections
Authors: Drouin Dominique , Gauvin Raynald , Joy David C. 
Published: July 2010

AbstractA formula is presented for computing the polar angle of collisions from partial elastic Mott cross‐sections. It will be useful in Monte Carlo simulations of electrons' trajectories in solids and is based on the Newbury and Myklebust (1981) expression. It also is valid for all energy ranging from 0.1 to 30 keV. Also given is the tabulation of the constants of this formula to compute polar angles of collisions for the first 94 elements of the periodic table. The constants of this formula have been obtained by the numerical integration of the values of partial Mott cross‐sections computed by Czyżewski et al. (1990) using Thomas‐Fermi‐Dirac atomic potentials for atomic numbers >54 and Hartree‐fock potential for atomic numbers <55.
Quantitation of SEM EBIC and CL signals using Monte Carlo electron‐trajectory simulations
Authors: Holt D. B. , Napchan E. 
Published: July 2010

AbstractA microcomputer Monte Carlo program simulates electron trajectories in solids and describes the distribution of energy deposited throughout the energy‐dissipation (electron‐hole pair generation) volume. From this distribution, the electron‐beam‐induced current or cathodoluminescence signal that will be generated can be calculated for the chosen beam conditions in a multilayer specimen of any geometry and compositions. The use of this program is illustrated by applications (1) to simulate curves of cathodoluminescence intensity versus beam energy for fitting to experimental data to evaluate materials and device parameters, (2) to calculate the energy deposited in each layer of a HEMT structure in which electron‐beam‐induced current studies are in progress, and (3) to the simulation of defect contrast linescan profiles which are compared to experimental observations.
Charge‐sensitive secondary electron imaging of diamond microstructures
Authors: Harker A. B. , Howitt D. G. , DeNatale J. F. , Flintoff J. F. 
Published: July 2010

AbstractThe surface orientation and detailed defect microstructure of polycrystalline diamond can be observed in a scanning electron microscope through local changes in the surface conductivity. The electron contrast in uncoated samples is straightforward to distinguish when the rms surface roughness is less than about 2 nm. This degree of smoothness occurs on some of the faceted surfaces of individual diamond grains but can also be achieved by polishing. The contrast, observable only in the secondary electron imaging mode, shows a strong dependence on both beam voltage and current. It is postulated that the contrast is produced solely by the differential rate at which the electron beam‐induced charge can be locally dissipated through crystalline defects and grain boundaries in the otherwise highly nonconductive diamond matrix. The appearance of the charge‐related contrast requires that highly connected pathways exist between the crystalline defects and the high‐angle grain boundaries.
SEM investigations of etched heavy ion tracks
Authors: Vetter Johann 
Published: July 2010

AbstractIt is shown that the scanning electron microscope (SEM) is an invaluable tool for the investigation of etched ion tracks, particularly in the submicron range. The SEM makes it possible to measure doses with track detectors two orders of magnitude higher than when they are measured by a light microscope. Furthermore, the SEM is used for investigation of the etched‐track cross sections over the full length of the channels. Growing of metal needles in the membranes by microgalvanic deposition allows replication of the form of the etched channels. After the membrane is dissolved, the metal needle replicas instead of the membrane can be investigated. It will be shown that the SEM is an important tool for the investigation of etched heavy ion tracks in solids.
Representation of scanning probe images in virtual reality
Authors: Kasas S. , Solletti J. M. , Cargnello R. 
Published: July 2010

AbstractThe visualization of the data obtained with scanning probe microscopes can be improved by the use of virtual reality software which has recently become available commercially. One such software program was applied to images obtained with an atomic force microscope. The mapping capabilities of this new visualization technique as well as the images were quite striking when viewed in virtual reality.
Volume measurements in three‐dimensional microscopy
Authors: Visser T. D. , Oud J. L. 
Published: July 2010

AbstractA refractive index mismatch between the oil immersion and the microscopic object can lead to a severe over‐estimation of the object's size. The cause of this effect is explained and a simple calibration method to compensate for its occurrence is presented. A practical example is discussed. The analysis applies to both conventional three‐dimensional, and confocal microscopy.
The boundary fitted coordinate method to improve the numerical analysis of electron optical systems
Authors: Khursheed A. 
Published: July 2010

AbstractThis paper illustrates some of the advantages of using the boundary fitted coordinate technique in the numerical simulation of electron‐optical systems. The boundary fitted coordinate technique can be used as an automatic mesh generator for the finite‐element solution of field distributions, while at the same time allowing for the possibility of high order inter‐polation on the mesh, typically required for the accurate plotting of electron trajectory paths. For the finite difference method of solving field distributions, the boundary fitted coordinate method can generate regular meshes, which fit curved shaped boundaries.
Identification of fenestrated capillary segments in microvascular corrosion casts of the rat exocrine pancreas
Authors: Aharinejad Seyedhossein , Böck Peter 
Published: July 2010

AbstractThe capillary bed of the rat exocrine pancreas was studied by scanning and transmission electron microscopy of corrosion casts and tissue sections. Two types of capillaries were distinguished in corrosion casts. First, there were straight capillaries of relatively constant width (mean diameter 4.79±0.87 μm), which were characterized by numerous circular constrictions on their surface. About 37% of the capillaries belonged to this type. Second, there were undulating capillaries which showed smooth surfaced eccentric dilatations defined by similar surface constrictions. The bulging areas measured 8.43 ± 1.33 μm, the constrictions next to the bulges figured for 6.45 ± 1.53 μm. About 63% of the capillaries belonged to the second type. Two types of capillaries were also identified in tissue sections. First, there were capillaries with continuous endothelial lining (26% of capillary profiles; mean diameter 5.48 ± 1.67 μm); 27% of their endothelial lining was provided with underlying pericytes. Second, there were capillaries with fenestrated endothelium (64% of capillary profiles; mean diameter 6.16 ± 1.75 μm); 12% of their endothelial lining was accompanied by pericytes. According to frequency and dimension of these two types of capillaries, we conclude that bulged and undulating capillary casts correspond to fenestrated capillaries and straight capillary casts of constant width correspond to nonfenestrated capillaries. The frequency of crests on the surface of capillary casts correlates with the different frequency of pericyte processes on fenestrated and nonfenestrated capillaries. It is concluded that pericyte processes beneath the endothelium hold resistance against luminal pressure. Bulging areas of capillary casts correlate with fenestrated areas of endothelial lining, that is, areas which are not reinforced by pericyte processes.
Half‐scan cone‐beam X‐ray microtomography formula
Authors: Wang G. , Liu Y. , Lin T. H. , Cheng P. C. 
Published: July 2010

AbstractAn x‐ray shadow projection microtomographic system using a scannable point source is under development at AMIL‐ARTS, SUNY at Buffalo. To overcome the limitations of the commonly used Feldkamp's cone‐beam reconstruction formula, we have developed a generalized Feldkamp‐type cone‐beam reconstruction formula. In the generalized Feldkamp‐type cone‐beam reconstruction, a scanning locus can be either planar or helix‐like, and a transaxial slice is reconstructed using projection data collected from a 360° angular range (full scan). In this paper, the full‐scan cone‐beam formula is modified to require only projection data of approximate 180° plus two fan‐angles (half scan). First, a half‐scan derivative‐free noncircular fan‐beam reconstruction formula is formulated. Then, a half‐scan cone‐beam reconstruction formula is derived as an extension of the half‐scan fan‐beam reconstruction formula using Feldkamp's procedure. Typical numerical simulation results are given for both half‐scan formulae. Compared with the full‐scan cone‐beam formula, the half‐scan cone‐beam formula reduces the involved angular range of projection data and allows better longitudinal/temporal resolution.
Laser and tandem scanning confocal microscopic studies of rabbit corneal wound healing
Authors: Ichijima Hideji , Jester James V. , Petroll W. Matthew , Cavanagh H. Dwight 
Published: July 2010

AbstractThe process of corneal endothelial wound healing was studied using laser and tandem scanning confocal microscopy (LSCM and TSCM). Following transcorneal freeze (TCF) injury, rabbit corneas were observed using ex vivo LSCM and in vivo TSCM. LSCM revealed the intracellular actin filament organization which, stained with phalloidin‐FITC, in migrating endothelial cells, transformed fibroblast‐like cells, stroma keratocytes, and epithelial cells during wound healing in corneal tissue. The TSCM provided sequential spatial observation of morphologic changes from endothelium to epithelium of the cornea during in vivo cellular repair of wound healing noninvasively on the same cornea without animal sacrifice. Ex vivo LSCM supported the morphologic analysis of the in vivo TSCM observations.
High temporal and spatial resolution studies of bone cells using real‐time confocal reflection microscopy
Authors: Boyde A. , Vesely P. , Gray C. , Jones S. J. 
Published: July 2010

AbstractChick and rat bone‐derived cells were mounted in sealed coverslip‐covered chambers; individual osteoclasts (but also osteoblasts) were selected and studied at 37°C using three different types of high‐speed scanning confocal microscopes: (1) A Noran Tandem Scanning Microscope (TSM) was used with a low light level, cooled CCD camera for image transfer to a Noran TN8502 frame store‐based image analysing computer to make time lapse movie sequences using 0.1 s exposure periods, thus losing some of the advantage of the high frame rate of the TSM. Rapid focus adjustment using computer controlled piezo drivers permitted two or more focus planes to be imaged sequentially: thus (with additional light‐source shuttering) the reflection confocal image could be alternated with the phase contrast image at a different focus. Individual cells were followed for up to 5 days, suggesting no significant irradiation problem. (2) Exceptional temporal and spatial resolution is available in video rate laser confocal scanning microscopes (VRCSLMs). We used the Noran Odyssey unitary beam VRCSLM with an argon ion laser at 488 nm and acousto‐optic deflection (AOD) on the line axis: this instrument is truly and adjustably confocal in the reflection mode. (3) We also used the Lasertec 1LM11 line scan instrument, with an He‐Ne laser at 633 nm, and AOD for the frame scan. We discuss the technical problems and merits of the different approaches. The VRCSLMs documented rapid, real‐time oscillatory motion: all the methods used show rapid net movement of organelles within bone cells. The interference reflection mode gives particularly strong contrasts in confocal instruments. Phase contrast and other interference methods used in the microscopy of living cells can be used simultaneously in the TSM.
Confocal microscopy of corneal penetration by tarantula hairs
Authors: Kaufman S. C. , Chew S. J. , Capps S. C. , Beuerman R. W. 
Published: July 2010

AbstractIn vivo identification of foreign bodies in the cornea may be impossible if the size and/or location precludes visualization by slit lamp biomicroscopy, which has an upper limit of magnification of 50x. These limitations became obvious when we attempted to identify the offending material in the inflamed eye of a patient who complained of foreign body sensation after contact with a pet tarantula As a model of this clinical situation, we used a newly developed tandem scanning confocal microscope to observe and to photograph tarantula hairs as they penetrated the corneal stroma and endothelium and entered the anterior chamber in rabbit eyes. We found that, experimentally, the hairs penetrated the ocular tissues apparently without inciting inflammation or causing fibrosis. The instrument we used‐ a prototype with a Nipkow disk from Noran, Inc. (Middleton, Wis.) and a 25/0.8 na glycerin immersion lens (Plan‐Neofluor, Zeiss)–provides magnifications of 100–500X, real‐time viewing in vivo, optical sectioning, contrast control, high resolution, processing through image analysis systems, and video and hard copy output. We believe that confocal microscopy offers a new approach to the identification and localization of foreign bodies in the anterior segment, as well as to the visualization and diagnosis of ocular diseases, including bacterial, fungal, and other parasitic invasions, in the human eye.
In vivo observation of the human tear film by tandem scanning confocal microscopy
Authors: Mathers William D. , Daley Thomas E. 
Published: July 2010

AbstractA new method for observing normal and pathologic states of the human tear film using tandem scanning confocal microscopy is presented. The confocal microscope is configured with a horizontal light path, a 10 x dry objective, and an image‐intensified camera for collecting images at a magnification of approximately 150x. The advantages of confocal microscopy can be used to collect reflected images of the human tear film with improved detail and resolution.
Near fields of periodic gratings calculated using rigorous electromagnetic theory
Authors: Körner T. O. , Sheridan J. T. 
Published: July 2010

AbstractRigorous electromagnetic theory (REMT) can be used to calculate the fields above dielectric and metallic gratings. In this paper, by including evanescent orders, the near fields are presented. The Legendre method is used to carry out these calculations. In this method the fields in each of the homogeneous sections along a grating period are approximated by Legendre polynomials. This method is an exact eigenfunction method in which the eigenvalues are found using simple matrix eigenvalue/eigenvector algorithms. By carefully dealing with the boundary conditions, extremely deep and highly conducting gratings can be examined. The convergence of the diffraction orders and nonimplicit power conservation are used to test the results. Contour plots showing the absolute value of the E‐field near gratings for a large range of periods, depths, duty cycles, angles of incidence, and surface profiles are presented.
Highly controllable fabrication of fiber probe for photon scanning tunneling microscope
Authors: Pangaribuan Togar , Jiang Shudong , Ohtsu Motoichi 
Published: July 2010

AbstractA selective chemical etching was used to fabricate fiber probes for the photon scanning tunneling microscope (PSTM). The cladding diameter of the fiber probe was controlled by varying the first‐step etching time. The cone angle of the fiber probe tip was controlled by varying the doping ratio of the fiber and the composition of the etching solution. A cladding diameter of 8 μm and a tip diameter of about 3 nm were fabricated. The smallest cone angle was 14°.
Analysis of submicron particles by scanning electron microscopy‐energy‐dispersive X‐ray spectrometry—accuracy of size measurement
Authors: Mitsche S. , Poelt P. , Wagner J. 
Published: July 2010

AbstractScanning electron microscopy combined with energy‐dispersive x‐ray spectrometry (SEM‐EDXS) is widely used for particle analysis. In the case of submicron particles, especially for particles that are smaller than 300 nm, the measured particle size is influenced by specimen preparation, SEM operating parameters, the mean atomic number of the particles, and the threshold value used for binarization. The use of uncoated particles on a conductive substrate and image acquisition using an in‐lens detector are recommended for precise morphologic results in this size range.
Contactless optical scanning of fingerprints with 180° view
Authors: Palma J. , Liessner C. , Mil'Shtein S. 
Published: July 2010

AbstractFingerprint recognition technology is an integral part of criminal investigations. It is the basis for the design of numerous security systems in both the private and public sectors. In a recent study emulating the fingerprinting procedure with widely used optical scanners, it was found that, on average, the distance between ridges decreases about 20% when a finger is positioned on a scanner. Using calibrated silicon pressure sensors, the authors scanned the distribution of pressure across a finger, pixel by pixel, and also generated maps of the average pressure distribution during fingerprinting. Controlled loading of a finger demonstrated that it is impossible to reproduce the same distribution of pressure across a given finger during repeated fingerprinting procedures. Based on this study, a novel method of scanning the fingerprint with more than a 180° view was developed. Using a camera rotated around the finger, small slices of the entire image of the finger were acquired. Equal sized slices of the image were processed with a special program assembling a more than 180° view of the finger. Comparison of two images of the same fingerprint, namely the registered and actual images, could be performed by a new algorithm based on the symmetry of the correlation function. The novel method is the first contactless optical scanning technique to view 180° of a fingerprint without moving the finger. In a machine which is under design, it is expected that the full view of one finger would be acquired in about a second.
Differential interference contrast and confocal reflectance imaging of collagen organization in three‐dimensional matrices
Authors: Petroll W. Matthew 
Published: July 2010

AbstractThe remodeling of extracellular matrices by cells plays a defining role in developmental morphogenesis and wound healing as well as in tissue engineering. Three‐dimensional (3‐D) type I collagen matrices have been used extensively as an in vitro model for studying cell‐induced matrix reorganization at the macroscopic level. However, few studies have directly assessed the process of 3‐D extracellular matrix (ECM) remodeling at the cellular and subcellular level. In this study, we directly compare two imaging modalities for both quantitative and qualitative imaging of 3‐D collagen organization in vitro: differential interference contrast (DIC) and confocal reflectance imaging. The results demonstrate that two‐dimensional (2‐D) DIC images allow visualization of the same population of collagen fibrils as observed in 2‐D confocal reflectance images. Thus, DIC can be used for qualitative assessment of fibril organization, as well as tracking of fibril movement in sequential time‐lapse 2‐D images. However, we also found that quantitative techniques that can be applied to confocal reflectance images, such as Fourier transform analysis, give different results when applied to DIC images. Furthermore, common techniques used for 3‐D visualization and reconstruction of confocal reflectance datasets are not generally applicable to DIC. Overall, obtaining a complete understanding of cell‐matrix mechanical interactions will likely require a combination of both wide‐field DIC imaging to study rapid changes in ECM deformation which can occur within minutes, and confocal reflectance imaging to assess more gradual changes in cell‐induced compaction and alignment of ECM which occur over a longer time course.
Spectral characteristics of autofluorescence and second harmonic generation from ex vivo human skin induced by femtosecond laser and visible lasers
Authors: Chen Jianxin , Zhuo Shuangmu , Luo Tianshu , Jiang Xingshan , Zhao Jingjun 
Published: July 2010

AbstractThe spectral properties of one‐photon, two‐photon excited autofluorescence and second harmonic generation (SHG) from ex vivo human skin induced by a femtosecond (fs) laser and three visible lasers in backscattering geometry are systematically investigated. Our experimental results indicate that peak position of autofluorescence spectra from the dermis and epidermis shift toward long wavelengths, and the fluorescent intensity decreases when the excitation wavelength increases due to an effect of the excitation wavelength on autofluorescence signals. However, the intensity of the SHG signal in collagen has the maximal value of 800 nm excitation wavelength. This may be the result that the energy of the SHG signal is in resonance with an electronic absorption band. The two‐photon excited autofluorescence and SHG intensity all obey a quadratical dependence on the excitation power. Compared with the two‐photon excited fluorescence and SHG, the one‐photon excited fluorescence in the dermis and epidermis exhibits different spectral characteristics. The investigation of the spectral characteristics of autofluorescence and SHG from ex vivo human skin can provide new insights into morphologic structures and biochemical components of tissues, which are vital for improving the application of laser‐induced autofluorescence and SHG spectroscopy technique for noninvasive in vivo tissue diagnostics.
A software modeling approach for the design and analysis of cooperative optimization systems
Authors: Amo Ignacio J. G. del , Pelta David A. , Masegosa Antonio D. , Verdegay Jose L. 
Published: July 2010

AbstractOptimization problems are ubiquitous in our daily lives and one way to cope with them is using cooperative optimization systems that allow to obtain good enough, fast enough, and cheap enough solutions. From a practical point of view, the design and the analysis of such systems are complex tasks. In this work, an integrated system (DACOS) for helping in the design and analysis of cooperative, centralized optimization systems is presented. Also, the methodology used for the creation of DACOS (mainly, the use of software modeling) is described in detail. This may also be useful for researchers who want to build up their own system for their particular needs. DACOS has been developed using the Eclipse developing framework, which, among other advantages, is also able to automatically generate source code. Finally, a practical case of use is presented: the application of DACOS to the configuration and analysis of a cooperative strategy on a location problem. Copyright © 2010 John Wiley & Sons, Ltd.