A brief discussion about image quality and SEM methods for quantitative fractography of polymer composites.

Science.gov (United States)

Hein, L R O; Campos, K A; Caltabiano, P C R O; Kostov, K G

2013-01-01

The methodology for fracture analysis of polymeric composites with scanning electron microscopes (SEM) is still under discussion. Many authors prefer to use sputter coating with a conductive material instead of applying low-voltage (LV) or variable-pressure (VP) methods, which preserves the original surfaces. The present work examines the effects of sputter coating with 25 nm of gold on the topography of carbon-epoxy composites fracture surfaces, using an atomic force microscope. Also, the influence of SEM imaging parameters on fractal measurements is evaluated for the VP-SEM and LV-SEM methods. It was observed that topographic measurements were not significantly affected by the gold coating at tested scale. Moreover, changes on SEM setup leads to nonlinear outcome on texture parameters, such as fractal dimension and entropy values. For VP-SEM or LV-SEM, fractal dimension and entropy values did not present any evident relation with image quality parameters, but the resolution must be optimized with imaging setup, accompanied by charge neutralization. © Wiley Periodicals, Inc.

Investigation of hidden periodic structures on SEM images of opal-like materials using FFT and IFFT.

Science.gov (United States)

Stephant, Nicolas; Rondeau, Benjamin; Gauthier, Jean-Pierre; Cody, Jason A; Fritsch, Emmanuel

2014-01-01

We have developed a method to use fast Fourier transformation (FFT) and inverse fast Fourier transformation (IFFT) to investigate hidden periodic structures on SEM images. We focused on samples of natural, play-of-color opals that diffract visible light and hence are periodically structured. Conventional sample preparation by hydrofluoric acid etch was not used; untreated, freshly broken surfaces were examined at low magnification relative to the expected period of the structural features, and, the SEM was adjusted to get a very high number of pixels in the images. These SEM images were treated by software to calculate autocorrelation, FFT, and IFFT. We present how we adjusted SEM acquisition parameters for best results. We first applied our procedure on an SEM image on which the structure was obvious. Then, we applied the same procedure on a sample that must contain a periodic structure because it diffracts visible light, but on which no structure was visible on the SEM image. In both cases, we obtained clearly periodic patterns that allowed measurements of structural parameters. We also investigated how the irregularly broken surface interfered with the periodic structure to produce additional periodicity. We tested the limits of our methodology with the help of simulated images. © 2014 Wiley Periodicals, Inc.

Quantitative roughness characterization and 3D reconstruction of electrode surface using cyclic voltammetry and SEM image

Energy Technology Data Exchange (ETDEWEB)

Dhillon, Shweta; Kant, Rama, E-mail: rkant@chemistry.du.ac.in

2013-10-01

Area measurements from cyclic voltammetry (CV) and image from scanning electron microscopy (SEM) are used to characterize electrode statistical morphology, 3D surface reconstruction and its electroactivity. SEM images of single phased materials correspond to two-dimensional (2D) projections of 3D structures, leading to an incomplete characterization. Lack of third dimension information in SEM image is circumvented using equivalence between denoised SEM image and CV area measurements. This CV-SEM method can be used to estimate power spectral density (PSD), width, gradient, finite fractal nature of roughness and local morphology of the electrode. We show that the surface morphological statistical property like distribution function of gradient can be related to local electro-activity. Electrode surface gradient micrographs generated here can provide map of electro-activity sites. Finally, the densely and uniformly packed small gradient over the Pt-surface is the determining criterion for high intrinsic electrode activity.

Quantitative roughness characterization and 3D reconstruction of electrode surface using cyclic voltammetry and SEM image

International Nuclear Information System (INIS)

Dhillon, Shweta; Kant, Rama

2013-01-01

Area measurements from cyclic voltammetry (CV) and image from scanning electron microscopy (SEM) are used to characterize electrode statistical morphology, 3D surface reconstruction and its electroactivity. SEM images of single phased materials correspond to two-dimensional (2D) projections of 3D structures, leading to an incomplete characterization. Lack of third dimension information in SEM image is circumvented using equivalence between denoised SEM image and CV area measurements. This CV-SEM method can be used to estimate power spectral density (PSD), width, gradient, finite fractal nature of roughness and local morphology of the electrode. We show that the surface morphological statistical property like distribution function of gradient can be related to local electro-activity. Electrode surface gradient micrographs generated here can provide map of electro-activity sites. Finally, the densely and uniformly packed small gradient over the Pt-surface is the determining criterion for high intrinsic electrode activity.

Super-resolution for asymmetric resolution of FIB-SEM 3D imaging using AI with deep learning.

Science.gov (United States)

Hagita, Katsumi; Higuchi, Takeshi; Jinnai, Hiroshi

2018-04-12

Scanning electron microscopy equipped with a focused ion beam (FIB-SEM) is a promising three-dimensional (3D) imaging technique for nano- and meso-scale morphologies. In FIB-SEM, the specimen surface is stripped by an ion beam and imaged by an SEM installed orthogonally to the FIB. The lateral resolution is governed by the SEM, while the depth resolution, i.e., the FIB milling direction, is determined by the thickness of the stripped thin layer. In most cases, the lateral resolution is superior to the depth resolution; hence, asymmetric resolution is generated in the 3D image. Here, we propose a new approach based on an image-processing or deep-learning-based method for super-resolution of 3D images with such asymmetric resolution, so as to restore the depth resolution to achieve symmetric resolution. The deep-learning-based method learns from high-resolution sub-images obtained via SEM and recovers low-resolution sub-images parallel to the FIB milling direction. The 3D morphologies of polymeric nano-composites are used as test images, which are subjected to the deep-learning-based method as well as conventional methods. We find that the former yields superior restoration, particularly as the asymmetric resolution is increased. Our super-resolution approach for images having asymmetric resolution enables observation time reduction.

Development of a SEM-based low-energy in-line electron holography microscope for individual particle imaging.

Science.gov (United States)

Adaniya, Hidehito; Cheung, Martin; Cassidy, Cathal; Yamashita, Masao; Shintake, Tsumoru

2018-05-01

A new SEM-based in-line electron holography microscope has been under development. The microscope utilizes conventional SEM and BF-STEM functionality to allow for rapid searching of the specimen of interest, seamless interchange between SEM, BF-STEM and holographic imaging modes, and makes use of coherent low-energy in-line electron holography to obtain low-dose, high-contrast images of light element materials. We report here an overview of the instrumentation and first experimental results on gold nano-particles and carbon nano-fibers for system performance tests. Reconstructed images obtained from the holographic imaging mode of the new microscope show substantial image contrast and resolution compared to those acquired by SEM and BF-STEM modes, demonstrating the feasibility of high-contrast imaging via low-energy in-line electron holography. The prospect of utilizing the new microscope to image purified biological specimens at the individual particle level is discussed and electron optical issues and challenges to further improve resolution and contrast are considered. Copyright © 2018 Elsevier B.V. All rights reserved.

Graphene-supporting films and low-voltage STEM in SEM toward imaging nanobio materials without staining: Observation of insulin amyloid fibrils.

Science.gov (United States)

Ogawa, Takashi; Gang, Geun Won; Thieu, Minh Thu; Kwon, Hyuksang; Ahn, Sang Jung; Ha, Tai Hwan; Cho, Boklae

2017-05-01

Utilization of graphene-supporting films and low-voltage scanning transmission electron microscopy (LV-STEM) in scanning electron microscopy (SEM) is shown to be an effective means of observing unstained nanobio materials. Insulin amyloid fibrils, which are implicated as a cause of type II diabetes, are formed in vitro and observed without staining at room temperature. An in-lens cold field-emission SEM, equipped with an additional homemade STEM detector, provides dark field (DF)-STEM images in the low energy range of 5-30keV, together with secondary electron (SE) images. Analysis based on Lenz's theory is used to interpret the experimental results. Graphene films, where the fibrils are deposited, reduce the background level of the STEM images compared with instances when conventional amorphous carbon films are used. Using 30keV, which is lower than that for conventional TEM (100-300keV), together with low detection angles (15-55mrad) enhances the signals from the fibrils. These factors improve image quality, which enables observation of thin fibrils with widths of 7-8nm. STEM imaging clearly reveals a twisted-ribbon structure of a fibril, and SE imaging shows an emphasized striped pattern of the fibril. The LV-STEM in SEM enables acquisition of two types of images of an identical fibril in a single instrument, which is useful for understanding the structure. This study expands the application of SEM to other systems of interest, which is beneficial to a large number of users. The method in this study can be applied to the observation of various nanobio materials and analysis of their native structures, thus contributing to research in materials and life sciences. Copyright © 2017 Elsevier Ltd. All rights reserved.

Willis PM 10-2.5 Precision Results, pdf has summary table and SEM images

Data.gov (United States)

U.S. Environmental Protection Agency — Precision data from the SEM and SEM images from the samples. This dataset is associated with the following publication: Peters, T., E. Sawvel, R. Willis, R. West,...

High resolution SEM imaging of gold nanoparticles in cells and tissues.

Science.gov (United States)

Goldstein, A; Soroka, Y; Frušić-Zlotkin, M; Popov, I; Kohen, R

2014-12-01

The growing demand of gold nanoparticles in medical applications increases the need for simple and efficient characterization methods of the interaction between the nanoparticles and biological systems. Due to its nanometre resolution, modern scanning electron microscopy (SEM) offers straightforward visualization of metallic nanoparticles down to a few nanometre size, almost without any special preparation step. However, visualization of biological materials in SEM requires complicated preparation procedure, which is typically finished by metal coating needed to decrease charging artefacts and quick radiation damage of biomaterials in the course of SEM imaging. The finest conductive metal coating available is usually composed of a few nanometre size clusters, which are almost identical to the metal nanoparticles employed in medical applications. Therefore, SEM monitoring of metal nanoparticles within cells and tissues is incompatible with the conventional preparation methods. In this work, we show that charging artefacts related to non-conductive biological specimen can be successfully eliminated by placing the uncoated biological sample on a conductive substrate. By growing the cells on glass pre-coated with a chromium layer, we were able to observe the uptake of 10 nm gold nanoparticles inside uncoated and unstained macrophages and keratinocytes cells. Imaging in back scattered electrons allowed observation of gold nanoparticles located inside the cells, while imaging in secondary electron gave information on gold nanoparticles located on the surface of the cells. By mounting a skin cross-section on an improved conductive holder, consisting of a silicon substrate coated with copper, we were able to observe penetration of gold nanoparticles of only 5 nm size through the skin barrier in an uncoated skin tissue. The described method offers a convenient modification in preparation procedure for biological samples to be analyzed in SEM. The method provides high

Cryo-SEM studies of latex/ceramic nanoparticle coating microstructure development.

Science.gov (United States)

Luo, Hui; Scriven, L E; Francis, Lorraine F

2007-12-15

Cryogenic scanning electron microscopy (cryo-SEM) was used to investigate microstructure development of composite coatings prepared from dispersions of antimony-doped tin oxide (ATO) nanoparticles (approximately 30 nm) or indium tin oxide (ITO) nanoparticles (approximately 40 nm) and latex particles (polydisperse, D(v): approximately 300 nm). Cryo-SEM images of ATO/latex dispersions as-frozen show small clusters of ATO and individual latex particles homogeneously distribute in a frozen water matrix. In contrast, cryo-SEM images of ITO/latex dispersions as-frozen show ITO particles adsorb onto latex particle surfaces. Electrostatic repulsion between negatively charged ATO and negatively charged latex particles stabilizes the ATO/latex dispersion, whereas in ITO/latex dispersion, positively charged ITO particles are attracted onto surfaces of negatively charged latex particles. These results are consistent with calculations of interaction potentials from past research. Cryo-SEM images of frozen and fractured coatings reveal that both ceramic nanoparticles and latex become more concentrated as drying proceeds; larger latex particles consolidate with ceramic nanoparticles in the interstitial spaces. With more drying, compaction flattens the latex-latex particle contacts and shrinks the voids between them. Thus, ceramic nanoparticles are forced to pack closely in the interstitial spaces, forming an interconnected network. Finally, latex particles partially coalesce at their flattened contacts, thereby yielding a coherent coating. The research reveals how nanoparticles segregate and interconnect among latex particles during drying.

Three dimensional imaging of surface geometry in SEM

International Nuclear Information System (INIS)

Slowko, W.

1997-01-01

A great advantage of scanning electron microscopy (SEM) is its ability of the surface topography in the way as a human eye is accustomed to see lights and shadows on macroobjects. However, SEM's can hardly display vertical dimensions of the structures. One of possible solutions is reconstruction of the surface profiles by directional detection of secondary electrons and proper signal processing. However, the surface profile still gives two dimensional information and the method should be extended to obtain fully three dimensional imaging. The extension consists in a simultaneous reconstruction of the surface profiles in two perpendicular directions (x and y) and their superposition. The solution proposed is based on a quadrupole detector system and a computer or analogue system for signal processing. Quantitative data of the surface topography can be displayed in many manners in the system of two or three co-ordinates with use of pseudo-colour for the altitude coding. (author)

Interpretation of secondary electron images obtained using a low vacuum SEM

International Nuclear Information System (INIS)

Toth, M.; Thiel, B.L.; Donald, A.M.

2003-01-01

Charging of insulators in a variable pressure environment was investigated in the context of secondary electron (SE) image formation. Sample charging and ionized gas molecules present in a low vacuum specimen chamber can give rise to SE image contrast. 'Charge-induced' SE contrast reflects lateral variations in the charge state of a sample caused by electron irradiation during and prior to image acquisition. This contrast corresponds to SE emission current alterations produced by sub-surface charge deposited by the electron beam. 'Ion-induced' contrast results from spatial inhomogeneities in the extent of SE signal inhibition caused by ions in the gaseous environment of a low vacuum scanning electron microscope (SEM). The inhomogeneities are caused by ion focusing onto regions of a sample that correspond to local minima in the magnitude of the surface potential (generated by sub-surface trapped charge), or topographic asperities. The two types of contrast exhibit characteristic dependencies on microscope operating parameters such as scan speed, beam current, gas pressure, detector bias and working distance. These dependencies, explained in terms of the behavior of the gaseous environment and sample charging, can serve as a basis for a correct interpretation of SE images obtained using a low vacuum SEM

Filler segmentation of SEM paper images based on mathematical morphology.

Science.gov (United States)

Ait Kbir, M; Benslimane, Rachid; Princi, Elisabetta; Vicini, Silvia; Pedemonte, Enrico

2007-07-01

Recent developments in microscopy and image processing have made digital measurements on high-resolution images of fibrous materials possible. This helps to gain a better understanding of the structure and other properties of the material at micro level. In this paper SEM image segmentation based on mathematical morphology is proposed. In fact, paper models images (Whatman, Murillo, Watercolor, Newsprint paper) selected in the context of the Euro Mediterranean PaperTech Project have different distributions of fibers and fillers, caused by the presence of SiAl and CaCO3 particles. It is a microscopy challenge to make filler particles in the sheet distinguishable from the other components of the paper surface. This objectif is reached here by using switable strutural elements and mathematical morphology operators.

Image contrast enhancement of Ni/YSZ anode during the slice-and-view process in FIB-SEM.

Science.gov (United States)

Liu, Shu-Sheng; Takayama, Akiko; Matsumura, Syo; Koyama, Michihisa

2016-03-01

Focused ion beam-scanning electron microscopy (FIB-SEM) is a widely used and easily operational equipment for three-dimensional reconstruction with flexible analysis volume. It has been using successfully and increasingly in the field of solid oxide fuel cell. However, the phase contrast of the SEM images is indistinct in many cases, which will bring difficulties to the image processing. Herein, the phase contrast of a conventional Ni/yttria stabilized zirconia anode is tuned in an FIB-SEM with In-Lens secondary electron (SE) and backscattered electron detectors. Two accessories, tungsten probe and carbon nozzle, are inserted during the observation. The former has no influence on the contrast. When the carbon nozzle is inserted, best and distinct contrast can be obtained by In-Lens SE detector. This method is novel for contrast enhancement. Phase segmentation of the image can be automatically performed. The related mechanism for different images is discussed. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

A SEM-correlation of the anatomy of the vitreous body: making visible the invisible.

Science.gov (United States)

Jongebloed, W L; Humalda, D; Worst, J F

1986-12-30

The naked human vitreous (sclera, iris and cornea removed) suspended in water does not reveal inner structures. After ink injection into the vitreous, the presence of different compartments and the existence of cisterns becomes evident. A concept of the internal system of cisterns is given on the basis of stereoscopic-lightmicroscopic images. An attempt is made to correlate images of the complete vitreous body, obtained with a stereo-lightmicroscope, with images of segments of cisternal walls produced with a scanning electron-microscope (SEM). A comparison is made between SEM-images of the vitreous bodies of human and rabbit eyes.

Performance of SEM scintillation detector evaluated by modulation transfer function and detective quantum efficiency function.

Science.gov (United States)

Bok, Jan; Schauer, Petr

2014-01-01

In the paper, the SEM detector is evaluated by the modulation transfer function (MTF) which expresses the detector's influence on the SEM image contrast. This is a novel approach, since the MTF was used previously to describe only the area imaging detectors, or whole imaging systems. The measurement technique and calculation of the MTF for the SEM detector are presented. In addition, the measurement and calculation of the detective quantum efficiency (DQE) as a function of the spatial frequency for the SEM detector are described. In this technique, the time modulated e-beam is used in order to create well-defined input signal for the detector. The MTF and DQE measurements are demonstrated on the Everhart-Thornley scintillation detector. This detector was alternated using the YAG:Ce, YAP:Ce, and CRY18 single-crystal scintillators. The presented MTF and DQE characteristics show good imaging properties of the detectors with the YAP:Ce or CRY18 scintillator, especially for a specific type of the e-beam scan. The results demonstrate the great benefit of the description of SEM detectors using the MTF and DQE. In addition, point-by-point and continual-sweep e-beam scans in SEM were discussed and their influence on the image quality was revealed using the MTF. © 2013 Wiley Periodicals, Inc.

Automated transmission-mode scanning electron microscopy (tSEM for large volume analysis at nanoscale resolution.

Directory of Open Access Journals (Sweden)

Masaaki Kuwajima

Full Text Available Transmission-mode scanning electron microscopy (tSEM on a field emission SEM platform was developed for efficient and cost-effective imaging of circuit-scale volumes from brain at nanoscale resolution. Image area was maximized while optimizing the resolution and dynamic range necessary for discriminating key subcellular structures, such as small axonal, dendritic and glial processes, synapses, smooth endoplasmic reticulum, vesicles, microtubules, polyribosomes, and endosomes which are critical for neuronal function. Individual image fields from the tSEM system were up to 4,295 µm(2 (65.54 µm per side at 2 nm pixel size, contrasting with image fields from a modern transmission electron microscope (TEM system, which were only 66.59 µm(2 (8.160 µm per side at the same pixel size. The tSEM produced outstanding images and had reduced distortion and drift relative to TEM. Automated stage and scan control in tSEM easily provided unattended serial section imaging and montaging. Lens and scan properties on both TEM and SEM platforms revealed no significant nonlinear distortions within a central field of ∼100 µm(2 and produced near-perfect image registration across serial sections using the computational elastic alignment tool in Fiji/TrakEM2 software, and reliable geometric measurements from RECONSTRUCT™ or Fiji/TrakEM2 software. Axial resolution limits the analysis of small structures contained within a section (∼45 nm. Since this new tSEM is non-destructive, objects within a section can be explored at finer axial resolution in TEM tomography with current methods. Future development of tSEM tomography promises thinner axial resolution producing nearly isotropic voxels and should provide within-section analyses of structures without changing platforms. Brain was the test system given our interest in synaptic connectivity and plasticity; however, the new tSEM system is readily applicable to other biological systems.

FIB-SEM tomography in biology.

Science.gov (United States)

Kizilyaprak, Caroline; Bittermann, Anne Greet; Daraspe, Jean; Humbel, Bruno M

2014-01-01

Three-dimensional information is much easier to understand than a set of two-dimensional images. Therefore a layman is thrilled by the pseudo-3D image taken in a scanning electron microscope (SEM) while, when seeing a transmission electron micrograph, his imagination is challenged. First approaches to gain insight in the third dimension were to make serial microtome sections of a region of interest (ROI) and then building a model of the object. Serial microtome sectioning is a tedious and skill-demanding work and therefore seldom done. In the last two decades with the increase of computer power, sophisticated display options, and the development of new instruments, an SEM with a built-in microtome as well as a focused ion beam scanning electron microscope (FIB-SEM), serial sectioning, and 3D analysis has become far easier and faster.Due to the relief like topology of the microtome trimmed block face of resin-embedded tissue, the ROI can be searched in the secondary electron mode, and at the selected spot, the ROI is prepared with the ion beam for 3D analysis. For FIB-SEM tomography, a thin slice is removed with the ion beam and the newly exposed face is imaged with the electron beam, usually by recording the backscattered electrons. The process, also called "slice and view," is repeated until the desired volume is imaged.As FIB-SEM allows 3D imaging of biological fine structure at high resolution of only small volumes, it is crucial to perform slice and view at carefully selected spots. Finding the region of interest is therefore a prerequisite for meaningful imaging. Thin layer plastification of biofilms offers direct access to the original sample surface and allows the selection of an ROI for site-specific FIB-SEM tomography just by its pronounced topographic features.

To see or not to see: Imaging surfactant coated nano-particles using HIM and SEM

International Nuclear Information System (INIS)

Hlawacek, Gregor; Ahmad, Imtiaz; Smithers, Mark A.; Kooij, E. Stefan

2013-01-01

Nano-particles are of great interest in fundamental and applied research. However, their accurate visualization is often difficult and the interpretation of the obtained images can be complicated. We present a comparative scanning electron microscopy and helium ion microscopy study of cetyltrimethylammonium-bromide (CTAB) coated gold nano-rods. Using both methods we show how the gold core as well as the surrounding thin CTAB shell can selectively be visualized. This allows for a quantitative determination of the dimensions of the gold core or the CTAB shell. The obtained CTAB shell thickness of 1.0 nm–1.5 nm is in excellent agreement with earlier results using more demanding and reciprocal space techniques. - Author-Highlights: • CTAB coated gold nano-rods were imaged using high resolution imaging tools. • Selective imaging of either the gold core or CTAB shell is possible with HIM and SEM. • CTAB shell thickness measured using HIM and SEM agrees well with literature values

SD-SEM: sparse-dense correspondence for 3D reconstruction of microscopic samples.

Science.gov (United States)

Baghaie, Ahmadreza; Tafti, Ahmad P; Owen, Heather A; D'Souza, Roshan M; Yu, Zeyun

2017-06-01

Scanning electron microscopy (SEM) imaging has been a principal component of many studies in biomedical, mechanical, and materials sciences since its emergence. Despite the high resolution of captured images, they remain two-dimensional (2D). In this work, a novel framework using sparse-dense correspondence is introduced and investigated for 3D reconstruction of stereo SEM images. SEM micrographs from microscopic samples are captured by tilting the specimen stage by a known angle. The pair of SEM micrographs is then rectified using sparse scale invariant feature transform (SIFT) features/descriptors and a contrario RANSAC for matching outlier removal to ensure a gross horizontal displacement between corresponding points. This is followed by dense correspondence estimation using dense SIFT descriptors and employing a factor graph representation of the energy minimization functional and loopy belief propagation (LBP) as means of optimization. Given the pixel-by-pixel correspondence and the tilt angle of the specimen stage during the acquisition of micrographs, depth can be recovered. Extensive tests reveal the strength of the proposed method for high-quality reconstruction of microscopic samples. Copyright © 2017 Elsevier Ltd. All rights reserved.

Experimental investigation on the influence of instrument settings on pixel size and nonlinearity in SEM image formation

DEFF Research Database (Denmark)

Carli, Lorenzo; Genta, Gianfranco; Cantatore, Angela

2010-01-01

The work deals with an experimental investigation on the influence of three Scanning Electron Microscope (SEM) instrument settings, accelerating voltage, spot size and magnification, on the image formation process. Pixel size and nonlinearity were chosen as output parameters related to image...... quality and resolution. A silicon grating calibrated artifact was employed to investigate qualitatively and quantitatively, through a designed experiment approach, the parameters relevance. SEM magnification was found to account by far for the largest contribution on both parameters under consideration...

Signal-to-noise ratio enhancement on SEM images using a cubic spline interpolation with Savitzky-Golay filters and weighted least squares error.

Science.gov (United States)

Kiani, M A; Sim, K S; Nia, M E; Tso, C P

2015-05-01

A new technique based on cubic spline interpolation with Savitzky-Golay smoothing using weighted least squares error filter is enhanced for scanning electron microscope (SEM) images. A diversity of sample images is captured and the performance is found to be better when compared with the moving average and the standard median filters, with respect to eliminating noise. This technique can be implemented efficiently on real-time SEM images, with all mandatory data for processing obtained from a single image. Noise in images, and particularly in SEM images, are undesirable. A new noise reduction technique, based on cubic spline interpolation with Savitzky-Golay and weighted least squares error method, is developed. We apply the combined technique to single image signal-to-noise ratio estimation and noise reduction for SEM imaging system. This autocorrelation-based technique requires image details to be correlated over a few pixels, whereas the noise is assumed to be uncorrelated from pixel to pixel. The noise component is derived from the difference between the image autocorrelation at zero offset, and the estimation of the corresponding original autocorrelation. In the few test cases involving different images, the efficiency of the developed noise reduction filter is proved to be significantly better than those obtained from the other methods. Noise can be reduced efficiently with appropriate choice of scan rate from real-time SEM images, without generating corruption or increasing scanning time. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

Information or resolution: Which is required from an SEM to study bulk inorganic materials?

Science.gov (United States)

Xing, Q

2016-11-01

Significant technological advances in scanning electron microscopy (SEM) have been achieved over the past years. Different SEMs can have significant differences in functionality and performance. This work presents the perspectives on selecting an SEM for research on bulk inorganic materials. Understanding materials demands quantitative composition and orientation information, and informative and interpretable images that reveal subtle differences in chemistry, orientation/structure, topography, and electronic structure. The capability to yield informative and interpretable images with high signal-to-noise ratios and spatial resolutions is an overall result of the SEM system as a whole, from the electron optical column to the detection system. The electron optical column determines probe performance. The roles of the detection system are to capture, filter or discriminate, and convert signal electrons to imaging information. The capability to control practical operating parameters including electron probe size and current, acceleration voltage or landing voltage, working distance, detector selection, and signal filtration is inherently determined by the SEM itself. As a platform for various accessories, e.g. an energy-dispersive spectrometer and an electron backscatter diffraction detector, the properties of the electron optical column, specimen chamber, and stage greatly affect the performance of accessories. Ease-of-use and ease-of-maintenance are of practical importance. It is practically important to select appropriate test specimens, design suitable imaging conditions, and analyze the specimen chamber geometry and dimensions to assess the overall functionality and performance of an SEM. For an SEM that is controlled/operated with a computer, the stable software and user-friendly interface significantly improve the usability of the SEM. SCANNING 38:864-879, 2016. © 2016 Wiley Periodicals, Inc. © Wiley Periodicals, Inc.

Framework for SEM contour analysis

Science.gov (United States)

Schneider, L.; Farys, V.; Serret, E.; Fenouillet-Beranger, C.

2017-03-01

SEM images provide valuable information about patterning capability. Geometrical properties such as Critical Dimension (CD) can be extracted from them and are used to calibrate OPC models, thus making OPC more robust and reliable. However, there is currently a shortage of appropriate metrology tools to inspect complex two-dimensional patterns in the same way as one would work with simple one-dimensional patterns. In this article we present a full framework for the analysis of SEM images. It has been proven to be fast, reliable and robust for every type of structure, and particularly for two-dimensional structures. To achieve this result, several innovative solutions have been developed and will be presented in the following pages. Firstly, we will present a new noise filter which is used to reduce noise on SEM images, followed by an efficient topography identifier, and finally we will describe the use of a topological skeleton as a measurement tool that can extend CD measurements on all kinds of patterns.

Distinction between amorphous and healed planar deformation features in shocked quartz using composite color scanning electron microscope cathodoluminescence (SEM-CL) imaging

Science.gov (United States)

Hamers, Maartje F.; Pennock, Gill M.; Herwegh, Marco; Drury, Martyn R.

2016-10-01

Planar deformation features (PDFs) in quartz are one of the most reliable and most widely used forms of evidence for hypervelocity impact. PDFs can be identified in scanning electron microscope cathodoluminescence (SEM-CL) images, but not all PDFs show the same CL behavior: there are nonluminescent and red luminescent PDFs. This study aims to explain the origin of the different CL emissions in PDFs. Focused ion beam (FIB) thin foils were prepared of specific sample locations selected in composite color SEM-CL images and were analyzed in a transmission electron microscope (TEM). The FIB preparation technique allowed a direct, often one-to-one correlation between the CL images and the defect structure observed in TEM. This correlation shows that composite color SEM-CL imaging allows distinction between amorphous PDFs on one hand and healed PDFs and basal Brazil twins on the other: nonluminescent PDFs are amorphous, while healed PDFs and basal Brazil twins are red luminescent, with a dominant emission peak at 650 nm. We suggest that the red luminescence is the result of preferential beam damage along dislocations, fluid inclusions, and twin boundaries. Furthermore, a high-pressure phase (possibly stishovite) in PDFs can be detected in color SEM-CL images by its blue luminescence.

Imaging and characterization of γ′ and γ″ nanoparticles in Inconel 718 by EDX elemental mapping and FIB–SEM tomography

Energy Technology Data Exchange (ETDEWEB)

Kulawik, K., E-mail: kulawik@agh.edu.pl [AGH University of Science and Technology, International Centre of Electron Microscopy for Materials Science, Faculty of Metals Engineering and Industrial Computer Science, Al. A. Mickiewicza 30, 30-059 Kraków (Poland); Buffat, P.A., E-mail: philippe.buffat@epfl.ch [AGH University of Science and Technology, International Centre of Electron Microscopy for Materials Science, Faculty of Metals Engineering and Industrial Computer Science, Al. A. Mickiewicza 30, 30-059 Kraków (Poland); Ecole Polytechnique Fédérale de Lausanne, CIME, Station 12, CH-1015 Lausanne Switzerland (Switzerland); Kruk, A., E-mail: kruczek@uci.agh.edu.pl [AGH University of Science and Technology, International Centre of Electron Microscopy for Materials Science, Faculty of Metals Engineering and Industrial Computer Science, Al. A. Mickiewicza 30, 30-059 Kraków (Poland); Wusatowska-Sarnek, A.M., E-mail: agnieszka.wusatowska-sarnek@pw.utc.com [Pratt & Whitney, 400 Main Street, East Hartford, CT 06108 (United States); Czyrska-Filemonowicz, A., E-mail: czyrska@agh.edu.pl [AGH University of Science and Technology, International Centre of Electron Microscopy for Materials Science, Faculty of Metals Engineering and Industrial Computer Science, Al. A. Mickiewicza 30, 30-059 Kraków (Poland)

2015-02-15

Microstructural characterization of Inconel 718 superalloy after three different heat treatment variants was performed by electron microscopy and electron tomography techniques, taking advantage of recent development in quantitative electron microscopy. Distribution maps of the chemical elements, collected by ChemiSTEM™ EDX system, offer a clear contrast between γ′, γ″, and the γ matrix. It was found that the γ′ phase contains mainly Ni, Al, and Ti, while the γ″ phase contains Ni, Nb, and Ti. Thus application of the Al and Nb STEM–EDX elemental maps enables identification and size measurements of γ′ and γ″ nanoparticles. 3D morphology of γ′ and γ″ precipitates was examined by electron microscopy and FIB–SEM tomography. Employed methods revealed that in all three heat treatment variants the γ′ particles are almost spheroidal while the γ″ precipitates are mainly elongated-disc shaped. However, the precipitate sizes differed for each variant contributing to differences in the yield strength. Tomographic images were used for estimation of the volume fraction of the both strengthening phases. - Highlights: • ChemiSTEM™ EDX elemental maps bring a fast mean to differentiate γ′ and γ″ particles. • Such maps enable for the explicit size measurements of γ′ and γ″ nanoparticles. • Explicit γ′ and γ″ phases total volume fraction was measured employing FIB–SEM. • γ′/γ″ co-precipitates and sandwich-like γ′/γ″/γ′ particles were present. • HRSTEM-HAADF imaging revealed atomic columns of the γ′/γ″ co-precipitates.

Spin-polarized SEM

International Nuclear Information System (INIS)

Konoto, Makoto

2007-01-01

Development of highly effective evaluation technology of magnetic structures on a nanometric scale is a key to understanding spintronics and related phenomena. A high-resolution spin-polarized scanning electron microscope (spin SEM) developed recently is quite suitable for probing such nanostructures because of the capability of analyzing local magnetization vectors in three dimensions. Utilizing the spin SEM, a layered antiferromagnetic structure with the 1nm-alternation of bilayer-sheet magnetization has been successfully resolved. The real-space imaging with full analysis of the temperature-dependent magnetization vectors will be demonstrated. (author)

3D reconstruction of SEM images by use of optical photogrammetry software.

Science.gov (United States)

Eulitz, Mona; Reiss, Gebhard

2015-08-01

Reconstruction of the three-dimensional (3D) surface of an object to be examined is widely used for structure analysis in science and many biological questions require information about their true 3D structure. For Scanning Electron Microscopy (SEM) there has been no efficient non-destructive solution for reconstruction of the surface morphology to date. The well-known method of recording stereo pair images generates a 3D stereoscope reconstruction of a section, but not of the complete sample surface. We present a simple and non-destructive method of 3D surface reconstruction from SEM samples based on the principles of optical close range photogrammetry. In optical close range photogrammetry a series of overlapping photos is used to generate a 3D model of the surface of an object. We adapted this method to the special SEM requirements. Instead of moving a detector around the object, the object itself was rotated. A series of overlapping photos was stitched and converted into a 3D model using the software commonly used for optical photogrammetry. A rabbit kidney glomerulus was used to demonstrate the workflow of this adaption. The reconstruction produced a realistic and high-resolution 3D mesh model of the glomerular surface. The study showed that SEM micrographs are suitable for 3D reconstruction by optical photogrammetry. This new approach is a simple and useful method of 3D surface reconstruction and suitable for various applications in research and teaching. Copyright © 2015 Elsevier Inc. All rights reserved.

FIB-SEM cathodoluminescence tomography: practical and theoretical considerations.

Science.gov (United States)

De Winter, D A M; Lebbink, M N; Wiggers De Vries, D F; Post, J A; Drury, M R

2011-09-01

Focused ion beam-scanning electron microscope (FIB-SEM) tomography is a powerful application in obtaining three-dimensional (3D) information. The FIB creates a cross section and subsequently removes thin slices. The SEM takes images using secondary or backscattered electrons, or maps every slice using X-rays and/or electron backscatter diffraction patterns. The objective of this study is to assess the possibilities of combining FIB-SEM tomography with cathodoluminescence (CL) imaging. The intensity of CL emission is related to variations in defect or impurity concentrations. A potential problem with FIB-SEM CL tomography is that ion milling may change the defect state of the material and the CL emission. In addition the conventional tilted sample geometry used in FIB-SEM tomography is not compatible with conventional CL detectors. Here we examine the influence of the FIB on CL emission in natural diamond and the feasibility of FIB-SEM CL tomography. A systematic investigation establishes that the ion beam influences CL emission of diamond, with a dependency on both the ion beam and electron beam acceleration voltage. CL emission in natural diamond is enhanced particularly at low ion beam and electron beam voltages. This enhancement of the CL emission can be partly explained by an increase in surface defects induced by ion milling. CL emission enhancement could be used to improve the CL image quality. To conduct FIB-SEM CL tomography, a recently developed novel specimen geometry is adopted to enable sequential ion milling and CL imaging on an untilted sample. We show that CL imaging can be manually combined with FIB-SEM tomography with a modified protocol for 3D microstructure reconstruction. In principle, automated FIB-SEM CL tomography should be feasible, provided that dedicated CL detectors are developed that allow subsequent milling and CL imaging without manual intervention, as the current CL detector needs to be manually retracted before a slice can be milled

Three-Dimensional (3D) Nanometrology Based on Scanning Electron Microscope (SEM) Stereophotogrammetry.

Science.gov (United States)

Tondare, Vipin N; Villarrubia, John S; Vlada R, András E

2017-10-01

Three-dimensional (3D) reconstruction of a sample surface from scanning electron microscope (SEM) images taken at two perspectives has been known for decades. Nowadays, there exist several commercially available stereophotogrammetry software packages. For testing these software packages, in this study we used Monte Carlo simulated SEM images of virtual samples. A virtual sample is a model in a computer, and its true dimensions are known exactly, which is impossible for real SEM samples due to measurement uncertainty. The simulated SEM images can be used for algorithm testing, development, and validation. We tested two stereophotogrammetry software packages and compared their reconstructed 3D models with the known geometry of the virtual samples used to create the simulated SEM images. Both packages performed relatively well with simulated SEM images of a sample with a rough surface. However, in a sample containing nearly uniform and therefore low-contrast zones, the height reconstruction error was ≈46%. The present stereophotogrammetry software packages need further improvement before they can be used reliably with SEM images with uniform zones.

Three-dimensional ultrastructure of osteocytes assessed by focused ion beam-scanning electron microscopy (FIB-SEM).

Science.gov (United States)

Hasegawa, Tomoka; Yamamoto, Tomomaya; Hongo, Hiromi; Qiu, Zixuan; Abe, Miki; Kanesaki, Takuma; Tanaka, Kawori; Endo, Takashi; de Freitas, Paulo Henrique Luiz; Li, Minqi; Amizuka, Norio

2018-04-01

The aim of this study is to demonstrate the application of focused ion beam-scanning electron microscopy, FIB-SEM for revealing the three-dimensional features of osteocytic cytoplasmic processes in metaphyseal (immature) and diaphyseal (mature) trabeculae. Tibiae of eight-week-old male mice were fixed with aldehyde solution, and treated with block staining prior to FIB-SEM observation. While two-dimensional backscattered SEM images showed osteocytes' cytoplasmic processes in a fragmented fashion, three-dimensional reconstructions of FIB-SEM images demonstrated that osteocytes in primary metaphyseal trabeculae extended their cytoplasmic processes randomly, thus maintaining contact with neighboring osteocytes and osteoblasts. In contrast, diaphyseal osteocytes extended thin cytoplasmic processes from their cell bodies, which ran perpendicular to the bone surface. In addition, these osteocytes featured thick processes that branched into thinner, transverse cytoplasmic processes; at some point, however, these transverse processes bend at a right angle to run perpendicular to the bone surface. Osteoblasts also possessed thicker cytoplasmic processes that branched off as thinner processes, which then connected with cytoplasmic processes of neighboring osteocytes. Thus, FIB-SEM is a useful technology for visualizing the three-dimensional structures of osteocytes and their cytoplasmic processes.

Determination of the fractal dimension surface of the fracture from SEM images with assistance of the computer image quantitative analysis system

International Nuclear Information System (INIS)

Wawszczak, J.

1999-01-01

This paper presents a procedure for quantitative image analysis for determination of the fractal dimension from SEM surface images of the fracture 0H14N5CuNb steel. Investigated quenched and tempered samples of the steel after impact tests (in room and -85 o C temperatures). This method can be useful for analysing local fractal dimension of any surface parts (not oriented) of the fracture with different topography of this surface. (author)

Uncertainty in the use of MAMA software to measure particle morphological parameters from SEM images

Energy Technology Data Exchange (ETDEWEB)

Schwartz, Daniel S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tandon, Lav [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2017-06-05

The MAMA software package developed at LANL is designed to make morphological measurements on a wide variety of digital images of objects. At LANL, we have focused on using MAMA to measure scanning electron microscope (SEM) images of particles, as this is a critical part of our forensic analysis of interdicted radiologic materials. In order to successfully use MAMA to make such measurements, we must understand the level of uncertainty involved in the process, so that we can rigorously support our quantitative conclusions.

Measuring topographies from conventional SEM acquisitions.

Science.gov (United States)

Shi, Qiwei; Roux, Stéphane; Latourte, Félix; Hild, François; Loisnard, Dominique; Brynaert, Nicolas

2018-04-27

The present study extends the stereoscopic imaging principle for estimating the surface topography to two orientations, namely, normal to the electron beam axis and inclined at 70° as suited for EBSD analyses. In spite of the large angle difference, it is shown that the topography can be accurately determined using regularized global Digital Image Correlation. The surface topography is compared to another estimate issued from a 3D FIB-SEM procedure where the sample surface is first covered by a Pt layer, and its initial topography is progressively revealed from successive FIB-milling. These two methods are successfully compared on a 6% strained steel specimen in an in situ mechanical test. This analysis is supplemented by a third approach estimating the change of topography from crystal rotations as measured from successive EBSD images. This last technique ignores plastic deformation, and thus only holds in an elastic regime. For the studied example, despite the large plastic flow, it is shown that crystal rotation already accounts for a significant part of the deformation-induced topography. Copyright © 2018 Elsevier B.V. All rights reserved.

EXPLORING MEDIATING ROLE OF INSTITUTIONAL IMAGE THROUGH A COMPLETE STRUCTURAL EQUATION MODELING (SEM: A PERSPECTVE OF HIGHER EDUCATION

Directory of Open Access Journals (Sweden)

Abu Osman

2018-06-01

Full Text Available The prime objective of this study is to investigate the mediating role of institutional image between student satisfaction, program quality, and service quality in the context of higher education. To attain this aim, the Nordic model was used as theoretical foundation of the study. The Structural Equation Modeling (SEM was used to analyze the influence of mediating variable and hypotheses testing. The population of this study was fourth-year business students of nine 'grade one' private universities in Bangladesh. Data (n=310 were gathered from students pursuing studies at different private universities in Bangladesh. The findings of this study revealed that image occupied full mediation role between student satisfaction and service quality. Furthermore, it also disclosed that the direct path of student satisfaction and service quality was not statistically significant. These exceptional findings indicate that academic experts should promote the institutional image, student satisfaction and program quality rigorously in order to enhance service quality of education. The outcomes of this study would provide substantial benefits to both practitioners and academics, especially in the context of private higher education. There is a deficiency of indirect link between student satisfaction, program quality and service quality. This study has integrated institutional image as a mediating variable to fulfill the deficiency between student satisfaction, program quality, and service quality.

SEM-microphotogrammetry, a new take on an old method for generating high-resolution 3D models from SEM images.

Science.gov (United States)

Ball, A D; Job, P A; Walker, A E L

2017-08-01

The method we present here uses a scanning electron microscope programmed via macros to automatically capture dozens of images at suitable angles to generate accurate, detailed three-dimensional (3D) surface models with micron-scale resolution. We demonstrate that it is possible to use these Scanning Electron Microscope (SEM) images in conjunction with commercially available software originally developed for photogrammetry reconstructions from Digital Single Lens Reflex (DSLR) cameras and to reconstruct 3D models of the specimen. These 3D models can then be exported as polygon meshes and eventually 3D printed. This technique offers the potential to obtain data suitable to reconstruct very tiny features (e.g. diatoms, butterfly scales and mineral fabrics) at nanometre resolution. Ultimately, we foresee this as being a useful tool for better understanding spatial relationships at very high resolution. However, our motivation is also to use it to produce 3D models to be used in public outreach events and exhibitions, especially for the blind or partially sighted. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

Attempt of correlative observation of morphological synaptic connectivity by combining confocal laser-scanning microscope and FIB-SEM for immunohistochemical staining technique.

Science.gov (United States)

Sonomura, Takahiro; Furuta, Takahiro; Nakatani, Ikuko; Yamamoto, Yo; Honma, Satoru; Kaneko, Takeshi

2014-11-01

Ten years have passed since a serial block-face scanning electron microscopy (SBF-SEM) method was developed [1]. In this innovative method, samples were automatically sectioned with an ultramicrotome placed inside a scanning electron microscope column, and the block surfaces were imaged one after another by SEM to capture back-scattered electrons. The contrast-inverted images obtained by the SBF-SEM were very similar to those acquired using conventional TEM. SFB-SEM has made easy to acquire image stacks of the transmission electron microscopy (TEM) in the mesoscale, which is taken with the confocal laser-scanning microcopy(CF-LSM).Furthermore, serial-section SEM has been combined with the focused ion beam (FIB) milling method [2]. FIB-incorporated SEM (FIB-SEM) has enabled the acquisition of three-dimensional images with a higher z-axis resolution com- pared to ultramicrotome-equipped SEM.We tried immunocytochemistry for FIB-SEM and correlated this immunoreactivity with that in CF-LSM. Dendrites of neurons in the rat neostriatum were visualized using a recombinant viral vector. Moreover, the thalamostriatal afferent terminals were immunolabeled with Cy5 fluorescence for vesicular glutamate transporter 2 (VGluT2). After detection of the sites of terminals apposed to the dendrites by using CF-LSM, GFP and VGluT2 immunoreactivities were further developed for EM by using immunogold/silver enhancement and immunoperoxidase/diaminobenzidine (DAB) methods, respectively.We showed that conventional immuno-cytochemical staining for TEM was applicable to FIB-SEM. Furthermore, several synaptic contacts, which were thought to exist on the basis of CF-LSM findings, were confirmed with FIB-SEM, revealing the usefulness of the combined method of CF-LSM and FIB-SEM. © The Author 2014. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Advanced metrology by offline SEM data processing

Science.gov (United States)

Lakcher, Amine; Schneider, Loïc.; Le-Gratiet, Bertrand; Ducoté, Julien; Farys, Vincent; Besacier, Maxime

2017-06-01

Today's technology nodes contain more and more complex designs bringing increasing challenges to chip manufacturing process steps. It is necessary to have an efficient metrology to assess process variability of these complex patterns and thus extract relevant data to generate process aware design rules and to improve OPC models. Today process variability is mostly addressed through the analysis of in-line monitoring features which are often designed to support robust measurements and as a consequence are not always very representative of critical design rules. CD-SEM is the main CD metrology technique used in chip manufacturing process but it is challenged when it comes to measure metrics like tip to tip, tip to line, areas or necking in high quantity and with robustness. CD-SEM images contain a lot of information that is not always used in metrology. Suppliers have provided tools that allow engineers to extract the SEM contours of their features and to convert them into a GDS. Contours can be seen as the signature of the shape as it contains all the dimensional data. Thus the methodology is to use the CD-SEM to take high quality images then generate SEM contours and create a data base out of them. Contours are used to feed an offline metrology tool that will process them to extract different metrics. It was shown in two previous papers that it is possible to perform complex measurements on hotspots at different process steps (lithography, etch, copper CMP) by using SEM contours with an in-house offline metrology tool. In the current paper, the methodology presented previously will be expanded to improve its robustness and combined with the use of phylogeny to classify the SEM images according to their geometrical proximities.

Enhancing nanoscale SEM image segmentation and reconstruction with crystallographic orientation data and machine learning

International Nuclear Information System (INIS)

Converse, Matthew I.; Fullwood, David T.

2013-01-01

Current methods of image segmentation and reconstructions from scanning electron micrographs can be inadequate for resolving nanoscale gaps in composite materials (1–20 nm). Such information is critical to both accurate material characterizations and models of piezoresistive response. The current work proposes the use of crystallographic orientation data and machine learning for enhancing this process. It is first shown how a machine learning algorithm can be used to predict the connectivity of nanoscale grains in a Nickel nanostrand/epoxy composite. This results in 71.9% accuracy for a 2D algorithm and 62.4% accuracy in 3D. Finally, it is demonstrated how these algorithms can be used to predict the location of gaps between distinct nanostrands — gaps which would otherwise not be detected with the sole use of a scanning electron microscope. - Highlights: • A method is proposed for enhancing the segmentation/reconstruction of SEM images. • 3D crystallographic orientation data from a nickel nanocomposite is collected. • A machine learning algorithm is used to detect trends in adjacent grains. • This algorithm is then applied to predict likely regions of nanoscale gaps. • These gaps would otherwise be unresolved with the sole use of an SEM

Replication and dimensional quality control of industrial nanoscale surfaces using calibrated AFM measurements and SEM image processing

DEFF Research Database (Denmark)

Tosello, Guido; Hansen, Hans Nørgaard; Marinello, F.

2010-01-01

application of AFM to calibrate height, depth and pitch of sub-micrometer features and SEM image processing to detect replication accuracy in terms of number of replicated features. Surface replication is analyzed using a metrological approach: nano-features on nickel stampers and injection...

Quantifying Golgi structure using EM: combining volume-SEM and stereology for higher throughput.

Science.gov (United States)

Ferguson, Sophie; Steyer, Anna M; Mayhew, Terry M; Schwab, Yannick; Lucocq, John Milton

2017-06-01

Investigating organelles such as the Golgi complex depends increasingly on high-throughput quantitative morphological analyses from multiple experimental or genetic conditions. Light microscopy (LM) has been an effective tool for screening but fails to reveal fine details of Golgi structures such as vesicles, tubules and cisternae. Electron microscopy (EM) has sufficient resolution but traditional transmission EM (TEM) methods are slow and inefficient. Newer volume scanning EM (volume-SEM) methods now have the potential to speed up 3D analysis by automated sectioning and imaging. However, they produce large arrays of sections and/or images, which require labour-intensive 3D reconstruction for quantitation on limited cell numbers. Here, we show that the information storage, digital waste and workload involved in using volume-SEM can be reduced substantially using sampling-based stereology. Using the Golgi as an example, we describe how Golgi populations can be sensed quantitatively using single random slices and how accurate quantitative structural data on Golgi organelles of individual cells can be obtained using only 5-10 sections/images taken from a volume-SEM series (thereby sensing population parameters and cell-cell variability). The approach will be useful in techniques such as correlative LM and EM (CLEM) where small samples of cells are treated and where there may be variable responses. For Golgi study, we outline a series of stereological estimators that are suited to these analyses and suggest workflows, which have the potential to enhance the speed and relevance of data acquisition in volume-SEM.

lsnjbhakta@gmail.com A Comparative SEM-EDS Elemental

African Journals Online (AJOL)

Michael Horsfall

effect on food production in terrestrial and aquatic compartment in ... Processing and SEM-EDS analysis of mud: In the laboratory, the ... and for SEM image observation was 15 kV, applying .... by weathering in the Omi acid clay deposit, Japan.

Correlative SEM SERS for quantitative analysis of dimer nanoparticles.

Science.gov (United States)

Timmermans, F J; Lenferink, A T M; van Wolferen, H A G M; Otto, C

2016-11-14

A Raman microscope integrated with a scanning electron microscope was used to investigate plasmonic structures by correlative SEM-SERS analysis. The integrated Raman-SEM microscope combines high-resolution electron microscopy information with SERS signal enhancement from selected nanostructures with adsorbed Raman reporter molecules. Correlative analysis is performed for dimers of two gold nanospheres. Dimers were selected on the basis of SEM images from multi aggregate samples. The effect of the orientation of the dimer with respect to the polarization state of the laser light and the effect of the particle gap size on the Raman signal intensity is observed. Additionally, calculations are performed to simulate the electric near field enhancement. These simulations are based on the morphologies observed by electron microscopy. In this way the experiments are compared with the enhancement factor calculated with near field simulations and are subsequently used to quantify the SERS enhancement factor. Large differences between experimentally observed and calculated enhancement factors are regularly detected, a phenomenon caused by nanoscale differences between the real and 'simplified' simulated structures. Quantitative SERS experiments reveal the structure induced enhancement factor, ranging from ∼200 to ∼20 000, averaged over the full nanostructure surface. The results demonstrate correlative Raman-SEM microscopy for the quantitative analysis of plasmonic particles and structures, thus enabling a new analytical method in the field of SERS and plasmonics.

The importance of scanning electron microscopy (sem in taxonomy and morphology of Chironomidae (Diptera

Directory of Open Access Journals (Sweden)

Andrzej Kownacki

2015-07-01

Full Text Available The paper reports on the value of scanning electron microscopy (SEM in the taxonomy and morphology of Chironomidae. This method has been relatively rarely used in Chironomidae studies. Our studies suggest that the SEM method provides a lot of new information. For example, the plastron plate of the thoracic horn of Macropelopia nebulosa (Meigen under light microscopy is visible as points, while under SEM we have found that it consists of a reticular structure with holes. By using SEM a more precise picture of the body structure of Chironomidae can be revealed. It allows researchers to explain inconsistencies in the existing descriptions of species. Another advantage of the SEM method is obtaining spatial images of the body and organs of Chironomidae. However, the SEM method also has some limitations. The main problem is dirt or debris (e.g. algae, mud, secretions, mucus, bacteria, etc., which often settles on the external surface of structures, especially those which are uneven or covered with hair. The dirt should be removed after collection of chironomid material because if left in place it can become chemically fixed to various surfaces. It unnecessarily remains at the surface and final microscopic images may contain artifacts that obscure chironomid structures being investigated. In this way many details of the surface are thus unreadable. The results reported here indicate that SEM examination helps us to identify new morphological features and details that will facilitate the identification of species of Chironomidae and may help to clarify the function of various parts of the body. Fast development of electron microscope technique allows us to learn more about structure of different organisms.

Comparing the detection of iron-based pottery pigment on a carbon-coated sherd by SEM-EDS and by Micro-XRF-SEM.

Science.gov (United States)

Pendleton, Michael W; Washburn, Dorothy K; Ellis, E Ann; Pendleton, Bonnie B

2014-03-01

The same sherd was analyzed using a scanning electron microscope with energy dispersive spectroscopy (SEM-EDS) and a micro X-ray fluorescence tube attached to a scanning electron microscope (Micro-XRF-SEM) to compare the effectiveness of elemental detection of iron-based pigment. To enhance SEM-EDS mapping, the sherd was carbon coated. The carbon coating was not required to produce Micro-XRF-SEM maps but was applied to maintain an unbiased comparison between the systems. The Micro-XRF-SEM analysis was capable of lower limits of detection than that of the SEM-EDS system, and therefore the Micro-XRF-SEM system could produce elemental maps of elements not easily detected by SEM-EDS mapping systems. Because SEM-EDS and Micro-XRF-SEM have been used for imaging and chemical analysis of biological samples, this comparison of the detection systems should be useful to biologists, especially those involved in bone or tooth (hard tissue) analysis.

Developing 3D SEM in a broad biological context

Science.gov (United States)

Kremer, A; Lippens, S; Bartunkova, S; Asselbergh, B; Blanpain, C; Fendrych, M; Goossens, A; Holt, M; Janssens, S; Krols, M; Larsimont, J-C; Mc Guire, C; Nowack, MK; Saelens, X; Schertel, A; Schepens, B; Slezak, M; Timmerman, V; Theunis, C; Van Brempt, R; Visser, Y; GuÉRin, CJ

2015-01-01

When electron microscopy (EM) was introduced in the 1930s it gave scientists their first look into the nanoworld of cells. Over the last 80 years EM has vastly increased our understanding of the complex cellular structures that underlie the diverse functions that cells need to maintain life. One drawback that has been difficult to overcome was the inherent lack of volume information, mainly due to the limit on the thickness of sections that could be viewed in a transmission electron microscope (TEM). For many years scientists struggled to achieve three-dimensional (3D) EM using serial section reconstructions, TEM tomography, and scanning EM (SEM) techniques such as freeze-fracture. Although each technique yielded some special information, they required a significant amount of time and specialist expertise to obtain even a very small 3D EM dataset. Almost 20 years ago scientists began to exploit SEMs to image blocks of embedded tissues and perform serial sectioning of these tissues inside the SEM chamber. Using first focused ion beams (FIB) and subsequently robotic ultramicrotomes (serial block-face, SBF-SEM) microscopists were able to collect large volumes of 3D EM information at resolutions that could address many important biological questions, and do so in an efficient manner. We present here some examples of 3D EM taken from the many diverse specimens that have been imaged in our core facility. We propose that the next major step forward will be to efficiently correlate functional information obtained using light microscopy (LM) with 3D EM datasets to more completely investigate the important links between cell structures and their functions. Lay Description Life happens in three dimensions. For many years, first light, and then EM struggled to image the smallest parts of cells in 3D. With recent advances in technology and corresponding improvements in computing, scientists can now see the 3D world of the cell at the nanoscale. In this paper we present the

In Situ Characterization of Boehmite Particles in Water Using Liquid SEM.

Science.gov (United States)

Yao, Juan; Arey, Bruce W; Yang, Li; Zhang, Fei; Komorek, Rachel; Chun, Jaehun; Yu, Xiao-Ying

2017-09-27

In situ imaging and elemental analysis of boehmite (AlOOH) particles in water is realized using the System for Analysis at the Liquid Vacuum Interface (SALVI) and Scanning Electron Microscopy (SEM). This paper describes the method and key steps in integrating the vacuum compatible SAVLI to SEM and obtaining secondary electron (SE) images of particles in liquid in high vacuum. Energy dispersive x-ray spectroscopy (EDX) is used to obtain elemental analysis of particles in liquid and control samples including deionized (DI) water only and an empty channel as well. Synthesized boehmite (AlOOH) particles suspended in liquid are used as a model in the liquid SEM illustration. The results demonstrate that the particles can be imaged in the SE mode with good resolution (i.e., 400 nm). The AlOOH EDX spectrum shows significant signal from the aluminum (Al) when compared with the DI water and the empty channel control. In situ liquid SEM is a powerful technique to study particles in liquid with many exciting applications. This procedure aims to provide technical know-how in order to conduct liquid SEM imaging and EDX analysis using SALVI and to reduce potential pitfalls when using this approach.

Annual International DIC Society Conference and SEM Fall Conference

CERN Document Server

Reu, Phillip

2017-01-01

This collection represents a single volume of technical papers presented at the Annual International DIC Society Conference and SEM Fall Conference organized by the Society for Experimental Mechanics and Sandia National Laboratories and held in Philadelphia, PA, November 7-10, 2016. The volume presents early findings from experimental, standards development and various other investigations concerning digital image correlation - an important area within Experimental Mechanics. The area of Digital Image Correlation has been an integral track within the SEM Annual Conference spearheaded by Professor Michael Sutton from the University of South Carolina. In 2016, the SEM and Sandia joined their collaborative strengths to launch a standing fall meeting focusing specifically on developments in the area of Digital Image Correlation. The contributed papers within this volume span numerous technical aspects of DIC including standards development for the industry. .

Recent advances in 3D SEM surface reconstruction.

Science.gov (United States)

Tafti, Ahmad P; Kirkpatrick, Andrew B; Alavi, Zahrasadat; Owen, Heather A; Yu, Zeyun

2015-11-01

The scanning electron microscope (SEM), as one of the most commonly used instruments in biology and material sciences, employs electrons instead of light to determine the surface properties of specimens. However, the SEM micrographs still remain 2D images. To effectively measure and visualize the surface attributes, we need to restore the 3D shape model from the SEM images. 3D surface reconstruction is a longstanding topic in microscopy vision as it offers quantitative and visual information for a variety of applications consisting medicine, pharmacology, chemistry, and mechanics. In this paper, we attempt to explain the expanding body of the work in this area, including a discussion of recent techniques and algorithms. With the present work, we also enhance the reliability, accuracy, and speed of 3D SEM surface reconstruction by designing and developing an optimized multi-view framework. We then consider several real-world experiments as well as synthetic data to examine the qualitative and quantitative attributes of our proposed framework. Furthermore, we present a taxonomy of 3D SEM surface reconstruction approaches and address several challenging issues as part of our future work. Copyright © 2015 Elsevier Ltd. All rights reserved.

Platinum 'opal eyes' - an upgraded high resolution imaging standard for performance monitoring of FEG SEM and FEG VPSEM

International Nuclear Information System (INIS)

Griffin, B.J.

2003-01-01

Full text: The new generation of field emission variable pressure and conventional scanning electron microscopes [FEG (VP)SEM] are capable of extremely high resolution (e.g. 1nm 15kV) and, in parallel, imaging at very low accelerating voltages (e.g. 4 nm 0.1 kV). Most of this level of performance is in conventional high vacuum modes of operation, the variable pressure performances are lower but under rapid development. A synthetic opal sample with fine gold decoration on the 400nm silica spheres was described previously as a suitable standard for the routine monitoring of SEM performance. The sample was named 'OPAL EYES'. Whilst ideal for tungsten and LaBo filament sourced SEMs the level of detail was marginal for field emission SEM performance measurement for two reasons. Firstly, the fine gold decoration was highly variable in grain size and inconsistent between samples making comparable image collection difficult. Secondly the sample was prone to self-contamination and damage during imaging at high accelerating voltages or high magnifications. Overall the 'OPAL EYES' sample has been successful in its adoption by a number of service engineers and laboratories world-wide. A new processing step has been added to the previously described preparation process for the OPAL-EYES standard; a light sputter coating with platinum. The effect is dramatic and results in growth of (presumably -to be checked and reported on) Au-Pt features of remarkably consistent size within the central EYE regions of the sample. These outgrowths are proud of the substrate and often equi-dimensional at a size of ∼ 10 nm. The substrate detail is at a scale of ∼2-3 nm. The new Pt OPAL EYES have been used as a resolution test specimen on a recently installed FEG VPSEM with excellent results. An important feature of this new sample is the high contrast sharp-edged nature of the detail as this not only allows resolution measurement but also definition of interference (vibration, electric fields

TEM/SEM investigation of microstructural changes within the white etching area under rolling contact fatigue and 3-D crack reconstruction by focused ion beam

International Nuclear Information System (INIS)

Grabulov, A.; Ziese, U.; Zandbergen, H.W.

2007-01-01

The white etching area (WEA) surrounding the cracks formed under high-cycle rolling contact fatigue was investigated by transmission electron microscopy (TEM) and Dual Beam (scanning electron microscopy (SEM)/focused ion beam). SEM revealed the initiation of cracks formed around artificially introduced Al 2 O 3 inclusions in the model steel (composition similar to SAE 52100). TEM investigations showed a microstructural difference between the WEA (formation of nanocrystalline ferrite) and the steel matrix (tempered martensitic structure). A three-dimensional image of the crack reconstructed from ∼400 Dual Beam cross-section images is reported

Human cardiac telocytes: 3D imaging by FIB-SEM tomography.

Science.gov (United States)

Cretoiu, D; Hummel, E; Zimmermann, H; Gherghiceanu, M; Popescu, L M

2014-11-01

Telocyte (TC) is a newly identified type of cell in the cardiac interstitium (www.telocytes.com). TCs are described by classical transmission electron microscopy as cells with very thin and long telopodes (Tps; cellular prolongations) having podoms (dilations) and podomers (very thin segments). TCs' three-dimensional (3D) morphology is still unknown. Cardiac TCs seem to be particularly involved in long and short distance intercellular signalling and, therefore, their 3D architecture is important for understanding their spatial connections. Using focused ion beam scanning electron microscopy (FIB-SEM) we show, for the first time, the whole ultrastructural anatomy of cardiac TCs. 3D reconstruction of cardiac TCs by FIB-SEM tomography confirms that they have long, narrow but flattened (ribbon-like) telopodes, with humps generated by the podoms. FIB-SEM tomography also confirms the network made by TCs in the cardiac interstitium through adherens junctions. This study provides the first FIB-SEM tomography of a human cell type. © 2014 The Authors. Journal of Cellular and Molecular Medicine published by John Wiley & Sons Ltd and Foundation for Cellular and Molecular Medicine.

Structural characterization of degradation of ODS composite using SEM and XRM techniques

Directory of Open Access Journals (Sweden)

Oladayo OLANIRAN

2017-07-01

Full Text Available The structural characteristics and mechanisms of corrosion and wear of oxide dispersion strengthened stainless steel composite were investigated. Insitu synchrotron x-ray tomography was used as experimental technique for degradation analysis from the corrosion and tribology studies. Corrosion study was carried out using potential dynamic techniques while the tribology experiments were conducted using a tribometer with ball on disc method. The x-ray micro tomography data gave chronological description of crack initiation and propagation in 3D and revealed that pitting did not result from the oxide inclusion. The results also revealed the surface imaging capacity of SEM and XRM’s capability for imaging internal structures. Taber index measurement was used as a complimenting tool for tribology measurements. Tribological behaviour of the sinter Oxide Dispersion Strengthened (ODS steel composite depends on both the composition of the composite and the loading system.

Morphology of the European species of the aphid genus Eulachnus (Hemiptera: Aphididae: Lachninae) - A SEM comparative and integrative study.

Science.gov (United States)

Kanturski, Mariusz; Karcz, Jagna; Wieczorek, Karina

2015-09-01

Scanning electron microscopy (SEM) methods were used for the first time to elucidate the external morphology of the European species of the genus Eulachnus (Hemiptera: Aphididae: Lachninae), a representative genus of the conifer-feeding aphids tribe Eulachnini. We examined and compared the external morphology of apterous and alate viviparous females from the parthenogenetic generation as well as oviparous females and alate males belonging to the sexual generation. FE-SEM images based on HMDS and cryo-SEM preparation techniques revealed better image quality than the CPD technique in regard to surface tension and morphological signs of cell deteriorations (i.e., existence of depressions, drying artifacts and membrane blebs). Three morphologically different species groups "agilis", "brevipilosus" and "cembrae" were proposed due to the differences in head, antennae, legs and dorsal chaetotaxy as well as dorsal sclerotization. The most characteristic features and differences of representatives of these groups are presented and discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Preliminary SEM Observations on the Surface of Elastomeric Impression Materials after Immersion or Ozone Disinfection

Science.gov (United States)

Prombonas, Anthony; Yannikakis, Stavros; Karampotsos, Thanasis; Katsarou, Martha-Spyridoula; Drakoulis, Nikolaos

2016-01-01

Introduction Surface integrity of dental elastomeric impression materials that are subjected to disinfection is of major importance for the quality of the final prosthetic restorations. Aim The aim of this qualitative Scanning Electronic Microscopy (SEM) study was to reveal the effects of immersion or ozone disinfection on the surface of four dental elastomeric impression materials. Materials and Methods Four dental elastomeric impression material brands were used (two vinyl polysiloxane silicones, one polyether, and one vinyl polyether silicone). Total of 32 specimens were fabricated, eight from each impression material. Specimens were immersion (0.525% sodium hypochlorite solution or 0.3% benzalkonium chloride solution) or ozone disinfected or served as controls and examined with SEM. Results Surface degradation was observed on several speci-mens disinfected with 0.525% sodium hypochlorite solution. Similar wavy-wrinkling surface structures were observed in almost all specimens, when treated either with 0.3% benzalkonium chloride solution or ozone. Conclusion The SEM images obtained from this study revealed that both immersion disinfectants and ozone show similar impression material surface alterations. Ozone seems to be non-inferior as compared to immersion disinfectants, but superior as to environmental protection. PMID:28208993

SEM AutoAnalysis: enhancing photomask and NIL defect disposition and review

Science.gov (United States)

Schulz, Kristian; Egodage, Kokila; Tabbone, Gilles; Ehrlich, Christian; Garetto, Anthony

2017-06-01

For defect disposition and repair verification regarding printability, AIMS™ is the state of the art measurement tool in industry. With its unique capability of capturing aerial images of photomasks it is the one method that comes closest to emulating the printing behaviour of a scanner. However for nanoimprint lithography (NIL) templates aerial images cannot be applied to evaluate the success of a repair process. Hence, for NIL defect dispositioning scanning, electron microscopy (SEM) imaging is the method of choice. In addition, it has been a standard imaging method for further root cause analysis of defects and defect review on optical photomasks which enables 2D or even 3D mask profiling at high resolutions. In recent years a trend observed in mask shops has been the automation of processes that traditionally were driven by operators. This of course has brought many advantages one of which is freeing cost intensive labour from conducting repetitive and tedious work. Furthermore, it reduces variability in processes due to different operator skill and experience levels which at the end contributes to eliminating the human factor. Taking these factors into consideration, one of the software based solutions available under the FAVOR® brand to support customer needs is the aerial image evaluation software, AIMS™ AutoAnalysis (AAA). It provides fully automated analysis of AIMS™ images and runs in parallel to measurements. This is enabled by its direct connection and communication with the AIMS™tools. As one of many positive outcomes, generating automated result reports is facilitated, standardizing the mask manufacturing workflow. Today, AAA has been successfully introduced into production at multiple customers and is supporting the workflow as described above. These trends indeed have triggered the demand for similar automation with respect to SEM measurements leading to the development of SEM AutoAnalysis (SAA). It aims towards a fully automated SEM image

Role of scanning electron microscope )SEM) in metal failure analysis

International Nuclear Information System (INIS)

Shaiful Rizam Shamsudin; Hafizal Yazid; Mohd Harun; Siti Selina Abd Hamid; Nadira Kamarudin; Zaiton Selamat; Mohd Shariff Sattar; Muhamad Jalil

2005-01-01

Scanning electron microscope (SEM) is a scientific instrument that uses a beam of highly energetic electrons to examine the surface and phase distribution of specimens on a micro scale through the live imaging of secondary electrons (SE) and back-scattered electrons (BSE) images. One of the main activities of SEM Laboratory at MINT is for failure analysis on metal part and components. The capability of SEM is excellent for determining the root cause of metal failures such as ductility or brittleness, stress corrosion, fatigue and other types of failures. Most of our customers that request for failure analysis are from local petrochemical plants, manufacturers of automotive components, pipeline maintenance personnel and engineers who involved in the development of metal parts and component. This paper intends to discuss some of the technical concepts in failure analysis associated with SEM. (Author)

Characterisation of nanoparticles by means of high-resolution SEM/EDS in transmission mode

International Nuclear Information System (INIS)

Hodoroaba, V-D; Rades, S; Mielke, J; Ortel, E; Salge, T; Schmidt, R

2016-01-01

Advances in scanning electron microscopy (SEM) enable the high-resolution imaging of single nanoparticles (NPs) with sizes well below 10 nm. The SEM analysis in transmission mode (T-SEM) of NPs on thin film supports has many benefits when compared to the analysis of NPs on bulk substrates. The enhanced material (mass - thickness) contrast of the T-SEM imaging mode is well suited for in-depth and, particularly valuable, to very accurate, traceable, lateral dimensional measurements of NPs. Compared to samples prepared on bulk substrates, T-SEM with energy dispersive X-ray spectroscopy (EDS) achieves a drastically improved spatial resolution of the emitted X-rays. The poor signal-to-noise ratio of the X-ray spectra emitted by a single nanoparticle (NP) can be improved by the use of high-sensitivity (high collection solid angle) silicon drift (SDD), energy-dispersive X-ray spectrometers (EDS). The EDS spectral imaging of a single NP with a spatial resolution below 10 nm has become possible. This is demonstrated by means of various examples of nanostructures. Advanced data processing of T-SEM/EDS results sets the stage for the automated classification of NPs by feature analysis. This method combines the detection of morphological structures of interest by image processing of T-SEM micrographs with the chemical classification by EDS. (paper)

Hubble Images Reveal Jupiter's Auroras

Science.gov (United States)

1996-01-01

These images, taken by the Hubble Space Telescope, reveal changes in Jupiter's auroral emissions and how small auroral spots just outside the emission rings are linked to the planet's volcanic moon, Io. The images represent the most sensitive and sharply-detailed views ever taken of Jovian auroras.The top panel pinpoints the effects of emissions from Io, which is about the size of Earth's moon. The black-and-white image on the left, taken in visible light, shows how Io and Jupiter are linked by an invisible electrical current of charged particles called a 'flux tube.' The particles - ejected from Io (the bright spot on Jupiter's right) by volcanic eruptions - flow along Jupiter's magnetic field lines, which thread through Io, to the planet's north and south magnetic poles. This image also shows the belts of clouds surrounding Jupiter as well as the Great Red Spot.The black-and-white image on the right, taken in ultraviolet light about 15 minutes later, shows Jupiter's auroral emissions at the north and south poles. Just outside these emissions are the auroral spots. Called 'footprints,' the spots are created when the particles in Io's 'flux tube' reach Jupiter's upper atmosphere and interact with hydrogen gas, making it fluoresce. In this image, Io is not observable because it is faint in the ultraviolet.The two ultraviolet images at the bottom of the picture show how the auroral emissions change in brightness and structure as Jupiter rotates. These false-color images also reveal how the magnetic field is offset from Jupiter's spin axis by 10 to 15 degrees. In the right image, the north auroral emission is rising over the left limb; the south auroral oval is beginning to set. The image on the left, obtained on a different date, shows a full view of the north aurora, with a strong emission inside the main auroral oval.The images were taken by the telescope's Wide Field and Planetary Camera 2 between May 1994 and September 1995.This image and other images and data

Two novel approaches to study arthropod anatomy by using dualbeam FIB/SEM.

Science.gov (United States)

Di Giulio, Andrea; Muzzi, Maurizio

2018-03-01

Transmission Electron Microscopy (TEM) has always been the conventional method to study arthropod ultrastructure, while the use of Scanning Electron Microscopy (SEM) was mainly devoted to the examination of the external cuticular structures by secondary electrons. The new generation field emission SEMs are capable to generate images at sub-cellular level, comparable to TEM images employing backscattered electrons. The potential of this kind of acquisition becomes very powerful in the dual beam FIB/SEM where the SEM column is combined with a Focused Ion Beam (FIB) column. FIB uses ions as a nano-scalpel to slice samples fixed and embedded in resin, replacing traditional ultramicrotomy. We here present two novel methods, which optimize the use of FIB/SEM for studying arthropod anatomy. Copyright © 2017 Elsevier Ltd. All rights reserved.

Quantitative Analysis of Micro-porosity of Eco-material by Using SEM Technique

Institute of Scientific and Technical Information of China (English)

ZHANG Ji-ru; LIU Yuan-zhi; LIU Zu-de

2004-01-01

Microstructure of the eco-material combining vegetation recovery with slope protection is important for determining plant-growing properties.Several techniques for analyzing the eco-material microstructure are presented,including the freeze-cut-drying method of preparing samples for scanning electronic microscopy (SEM),the SEM image processing technique and quantifying analysis method of the SEM images,and etc.The aggregates and pores in SEM images are identified using the different mathematics operators,and their effects are compared.The areas of aggregates and pores are obtained using the operator of morphology,and the influences of different thresholds in image segmentation are also discussed.The results show that the method,in which the variation of non-maximum grey-level gradient is limited,improves the effect of edge detections due to a weak distinction existing at the edge between the aggregates and pores in image.The determination of the threshold should combine the image characteristic with filling operation,so as to assure the precision of the image analysis,in which the contact-segmentation is the simplest and most effective method.The results also show that the pore areas in eco-materials are generally larger than those in the correlative soils,and their increment is large as soil fabric being fine.These differences are related to admixture of expansive perliticThe operator of morphology provides a new method for the image analysis of other porous material microstructure such as soils and concretes.

On some contrast reversals in SEM: Application to metal/insulator systems

International Nuclear Information System (INIS)

Cazaux, Jacques

2008-01-01

Contrast changes of SEM images with experimental conditions (beam energy, angle of detection, etc.) are analyzed by combining physical arguments based on secondary electron emission (SEE) to instrumental arguments involving detection. Possible occurrences of contrast reversals are explored to illustrate these changes in a striking manner. Deduced from SEE yield data, simulated SEM images show a material contrast reversal for a Pt/quartz specimen, a result partly supported by real images of a Cr/quartz integrated circuit. A shift of reversal energy with the detector's position is deduced from a difference in secondary electrons (SE) angular distributions between metals and insulators. Similarly, changes of topographic contrast with detection conditions, specimen composition and angle of tilt are investigated and a possible contrast reversal is again indicated. Finally, it is shown how charging contrast deduced from the expected evolution of SEE yield during irradiation is amplified by in-lens detection: a point illustrated by a contrast reversal of images of SiC particles. The main application concerns a proper interpretation of SEM images that is essential in the investigation of devices obtained from lithographic processes. The discussion on material contrast outlines the difficulty in generalizing the present analysis based on published data and experimental strategies based on implementing specific attachments in the SEM or on biasing the specimen holder are suggested.

SEM-based characterization techniques

International Nuclear Information System (INIS)

Russell, P.E.

1986-01-01

The scanning electron microscope is now a common instrument in materials characterization laboratories. The basic role of the SEM as a topographic imaging system has steadily been expanding to include a variety of SEM-based analytical techniques. These techniques cover the range of basic semiconductor materials characterization to live-time device characterization of operating LSI or VLSI devices. This paper introduces many of the more commonly used techniques, describes the modifications or additions to a conventional SEM required to utilize the techniques, and gives examples of the use of such techniques. First, the types of signals available from a sample being irradiated by an electron beam are reviewed. Then, where applicable, the type of spectroscopy or microscopy which has evolved to utilize the various signal types are described. This is followed by specific examples of the use of such techniques to solve problems related to semiconductor technology. Techniques emphasized include: x-ray fluorescence spectroscopy, electron beam induced current (EBIC), stroboscopic voltage analysis, cathodoluminescnece and electron beam IC metrology. Current and future trends of some of the these techniques, as related to the semiconductor industry are discussed

GAGG:ce single crystalline films: New perspective scintillators for electron detection in SEM

International Nuclear Information System (INIS)

Bok, Jan; Lalinský, Ondřej; Hanuš, Martin; Onderišinová, Zuzana; Kelar, Jakub; Kučera, Miroslav

2016-01-01

Single crystal scintillators are frequently used for electron detection in scanning electron microscopy (SEM). We report gadolinium aluminum gallium garnet (GAGG:Ce) single crystalline films as a new perspective scintillators for the SEM. For the first time, the epitaxial garnet films were used in a practical application: the GAGG:Ce scintillator was incorporated into a SEM scintillation electron detector and it showed improved image quality. In order to prove the GAGG:Ce quality accurately, the scintillation properties were examined using electron beam excitation and compared with frequently used scintillators in the SEM. The results demonstrate excellent emission efficiency of the GAGG:Ce single crystalline films together with their very fast scintillation decay useful for demanding SEM applications. - Highlights: • First practical application of epitaxial garnet films demonstrated in SEM. • Improved image quality of SEM equipped with GAGG:Ce single crystalline thin film scintillator. • Scintillation properties of GAGG:Ce films compared with standard bulk crystal scintillators.

Estimation of pattern shape based on CD-SEM image by using MPPC method

Science.gov (United States)

Onozuka, T.; Ojima, Y.; Meessen, J.; Rijpers, B.

2006-03-01

This study demonstrates the MPPC (Multiple Parameters Profile Characterization) measurement method utilizing ArF photo resist patterns. MPPC is a technique for estimating the three dimensional profile of patterns which are imaged and measured on the CD-SEM (critical dimension scanning electron microscope). MPPC utilizes the secondary electron signal to calculate several indices including top CD, peak CD, top rounding, bottom footing, etc. This primary focused of this study is to understand the variations in pattern profile caused by changes in exposure condition. The results demonstrate the ability to extract pattern profile shape information by MPPC measurement that could not otherwise be detected by a conventional bottom CD measurement method. Furthermore, the results were compared to cross sectional images collected by STEM (scanning transmission electron microscope) to verify the accuracy of the MPPC technique. The peak CD results accurately estimate the pattern width when the sidewall angle of the feature is nearly vertical. Additionally, line edge roughness (LER) caused by pattern profile variations was evaluated utilizing MPPC. The results suggest that MPPC may be utilized to evaluate the roughness over the entire profile.

Three-dimensional intracellular structure of a whole rice mesophyll cell observed with FIB-SEM.

Science.gov (United States)

Oi, Takao; Enomoto, Sakiko; Nakao, Tomoyo; Arai, Shigeo; Yamane, Koji; Taniguchi, Mitsutaka

2017-07-01

Ultrathin sections of rice leaf blades observed two-dimensionally using a transmission electron microscope (TEM) show that the chlorenchyma is composed of lobed mesophyll cells, with intricate cell boundaries, and lined with chloroplasts. The lobed cell shape and chloroplast positioning are believed to enhance the area available for the gas exchange surface for photosynthesis in rice leaves. However, a cell image revealing the three-dimensional (3-D) ultrastructure of rice mesophyll cells has not been visualized. In this study, a whole rice mesophyll cell was observed using a focused ion beam scanning electron microscope (FIB-SEM), which provides many serial sections automatically, rapidly and correctly, thereby enabling 3-D cell structure reconstruction. Rice leaf blades were fixed chemically using the method for conventional TEM observation, embedded in resin and subsequently set in the FIB-SEM chamber. Specimen blocks were sectioned transversely using the FIB, and block-face images were captured using the SEM. The sectioning and imaging were repeated overnight for 200-500 slices (each 50 nm thick). The resultant large-volume image stacks ( x = 25 μm, y = 25 μm, z = 10-25 μm) contained one or two whole mesophyll cells. The 3-D models of whole mesophyll cells were reconstructed using image processing software. The reconstructed cell models were discoid shaped with several lobes around the cell periphery. The cell shape increased the surface area, and the ratio of surface area to volume was twice that of a cylinder having the same volume. The chloroplasts occupied half the cell volume and spread as sheets along the cell lobes, covering most of the inner cell surface, with adjacent chloroplasts in close contact with each other. Cellular and sub-cellular ultrastructures of a whole mesophyll cell in a rice leaf blade are demonstrated three-dimensionally using a FIB-SEM. The 3-D models and numerical information support the hypothesis that rice mesophyll

FIB/SEM and SEM/EDS microstructural analysis of metal-ceramic and zirconia-ceramic interfaces.

Science.gov (United States)

Massimi, F; Merlati, G; Sebastiani, M; Battaini, P; Menghini, P; Bemporad, E

2012-01-10

Recently introduced FIB/SEM analysis in microscopy seems to provide a high-resolution characterization of the samples by 3D (FIB) cross-sectioning and (SEM) high resolution imaging. The aim of this study was to apply the FIB/SEM and SEM/EDS analysis to the interfaces of a metal-ceramic vs. two zirconia-ceramic systems. Plate samples of three different prosthetic systems were prepared in the dental lab following the manufacturers' instructions, where metal-ceramic was the result of a ceramic veneering (porcelain-fused-to-metal) and the two zirconia-ceramic systems were produced by the dedicated CAD-CAM procedures of the zirconia cores (both with final sintering) and then veneered by layered or heat pressed ceramics. In a FIB/SEM equipment (also called DualBeam), a thin layer of platinum (1 μm) was deposited on samples surface crossing the interfaces, in order to protect them during milling. Then, increasingly deeper trenches were milled by a focused ion beam, first using a relatively higher and later using a lower ion current (from 9 nA to 0.28 nA, 30KV). Finally, FEG-SEM (5KV) micrographs (1000-50,000X) were acquired. In a SEM the analysis of the morphology and internal microstructure was performed by 13KV secondary and backscattered electrons signals (in all the samples). The compositional maps were then performed by EDS probe only in the metal-ceramic system (20kV). Despite the presence of many voids in all the ceramic layers, it was possible to identify: (1) the grain structures of the metallic and zirconia substrates, (2) the thin oxide layer at the metal-ceramic interface and its interactions with the first ceramic layer (wash technique), (3) the roughness of the two different zirconia cores and their interactions with the ceramic interface, where the presence of zirconia grains in the ceramic layer was reported in two system possibly due to sandblasting before ceramic firing.

基于三次B样条函数的SEM图像处理%SEM Image Processing Based on Third- order B- spline Function

Institute of Scientific and Technical Information of China (English)

张健

2011-01-01

SEM images, for its unique practical testing significance, need in denoising also highlight its edges and accurate edge extraction positioning, So this paper adopts a partial differential method which can maintain the edges of the denoising and a extensive application of multi - scale wavelet analysis to detect edges, all based on third - order B - spline function as the core operator, for line width test of SEM image processing, This algorithm obtained the better denoising effect and maintained edge features for SEM images.%SEM图像由于其独特的实际测试意义,需要在去噪的同时突出边缘和准确的边缘提取定位,所以提出采用能够保持边缘的偏微分方法去噪和广泛应用的多尺度小波提取边缘,基于三次B样条函数作为核心算子,对用于线宽测试的SEM图像进行处理,获得了较好的去噪并保持边缘的效果以及清晰的图像边缘检测效果.

Improvement of CD-SEM mark position measurement accuracy

Science.gov (United States)

Kasa, Kentaro; Fukuhara, Kazuya

2014-04-01

CD-SEM is now attracting attention as a tool that can accurately measure positional error of device patterns. However, the measurement accuracy can get worse due to pattern asymmetry as in the case of image based overlay (IBO) and diffraction based overlay (DBO). For IBO and DBO, a way of correcting the inaccuracy arising from measurement patterns was suggested. For CD-SEM, although a way of correcting CD bias was proposed, it has not been argued how to correct the inaccuracy arising from pattern asymmetry using CD-SEM. In this study we will propose how to quantify and correct the measurement inaccuracy affected by pattern asymmetry.

Automated CD-SEM metrology for efficient TD and HVM

Science.gov (United States)

Starikov, Alexander; Mulapudi, Satya P.

2008-03-01

CD-SEM is the metrology tool of choice for patterning process development and production process control. We can make these applications more efficient by extracting more information from each CD-SEM image. This enables direct monitors of key process parameters, such as lithography dose and focus, or predicting the outcome of processing, such as etched dimensions or electrical parameters. Automating CD-SEM recipes at the early stages of process development can accelerate technology characterization, segmentation of variance and process improvements. This leverages the engineering effort, reduces development costs and helps to manage the risks inherent in new technology. Automating CD-SEM for manufacturing enables efficient operations. Novel SEM Alarm Time Indicator (SATI) makes this task manageable. SATI pulls together data mining, trend charting of the key recipe and Operations (OPS) indicators, Pareto of OPS losses and inputs for root cause analysis. This approach proved natural to our FAB personnel. After minimal initial training, we applied new methods in 65nm FLASH manufacture. This resulted in significant lasting improvements of CD-SEM recipe robustness, portability and automation, increased CD-SEM capacity and MT productivity.

Critical factors in SEM 3D stereo microscopy

DEFF Research Database (Denmark)

Marinello, F.; Bariano, P.; Savio, E.

2008-01-01

This work addresses dimensional measurements performed with the scanning electron microscope (SEM) using 3D reconstruction of surface topography through stereo-photogrammetry. The paper presents both theoretical and experimental investigations, on the effects of instrumental variables and measure......This work addresses dimensional measurements performed with the scanning electron microscope (SEM) using 3D reconstruction of surface topography through stereo-photogrammetry. The paper presents both theoretical and experimental investigations, on the effects of instrumental variables...... factors are recognized: the first one is related to the measurement operation and the instrument set-up; the second concerns the quality of scanned images and represents the major criticality in the application of SEMs for 3D characterizations....

High resolution SEM characterization of nano-precipitates in ODS steels.

Science.gov (United States)

Jóźwik, Iwona; Strojny-Nędza, Agata; Chmielewski, Marcin; Pietrzak, Katarzyna; Kurpaska, Łukasz; Nosewicz, Szymon

2018-05-01

The performance of the present-day scanning electron microscopy (SEM) extends far beyond delivering electronic images of the surface topography. Oxide dispersion strengthened (ODS) steel is on of the most promising materials for the future nuclear fusion reactor because of its good radiation resistance, and higher operation temperature up to 750°C. The microstructure of ODS should not exceed tens of nm, therefore there is a strong need in a fast and reliable technique for their characterization. In this work, the results of low-kV SEM characterization of nanoprecipitates formed in the ODS matrix are presented. Application of highly sensitive photo-diode BSE detector in SEM imaging allowed for the registration of single nm-sized precipitates in the vicinity of the ODS alloys. The composition of the precipitates has been confirmed by TEM-EDS. © 2018 Wiley Periodicals, Inc.

Refinement of Monte Carlo simulations of electron-specimen interaction in low-voltage SEM

International Nuclear Information System (INIS)

Kieft, Erik; Bosch, Eric

2008-01-01

A Monte Carlo tool is presented for the simulation of secondary electron (SE) emission in a scanning electron microscope (SEM). The tool is based on the Geant4 platform of CERN. The modularity of this platform makes it comparatively easy to add and test individual physical models. Our aim has been to develop a flexible and generally applicable tool, while at the same time including a good description of low-energy (<50 eV) interactions of electrons with matter. To this end we have combined Mott cross-sections with phonon-scattering based cross-sections for the elastic scattering of electrons, and we have adopted a dielectric function theory approach for inelastic scattering and generation of SEs. A detailed model of the electromagnetic fields from an actual SEM column has been included in the tool for ray tracing of secondary and backscattered electrons. Our models have been validated against experimental results through comparison of the simulation results with experimental yields, SE spectra and SEM images. It is demonstrated that the resulting simulation package is capable of quantitatively predicting experimental SEM images and is an important tool in building a deeper understanding of SEM imaging.

The Effect of Nonnormality on CB-SEM and PLS-SEM Path Estimates

OpenAIRE

Z. Jannoo; B. W. Yap; N. Auchoybur; M. A. Lazim

2014-01-01

The two common approaches to Structural Equation Modeling (SEM) are the Covariance-Based SEM (CB-SEM) and Partial Least Squares SEM (PLS-SEM). There is much debate on the performance of CB-SEM and PLS-SEM for small sample size and when distributions are nonnormal. This study evaluates the performance of CB-SEM and PLS-SEM under normality and nonnormality conditions via a simulation. Monte Carlo Simulation in R programming language was employed to generate data based on the theoretical model w...

On the use of SEM correlative tools for in situ mechanical tests.

Science.gov (United States)

Shi, Qiwei; Roux, Stéphane; Latourte, Félix; Hild, François; Loisnard, Dominique; Brynaert, Nicolas

2018-01-01

In situ SEM mechanical tests are key to study crystal plasticity. In particular, imaging and diffraction (EBSD) allow microstructure and surface kinematics to be monitored all along the test. However, to get a full benefit from different modalities, it is necessary to register all images and crystallographic orientation maps from EBSD into the same frame. Different correlative approaches tracking either Pt surface markings, crystal orientations or grain boundaries, allow such registrations to be performed and displacement as well as rotation fields to be measured, a primary information for crystal plasticity identification. However, the different contrasts that are captured in different modalities and unavoidable stage motions also give rise to artifacts that are to be corrected to register the different information onto the same material points. The same image correlation tools reveal very powerful to correct such artifacts. Illustrated by an in situ uniaxial tensile test performed on a bainitic-ferritic steel sample, recent advances in image correlation techniques are reviewed and shown to provide a comprehensive picture of local strain and rotation maps. Copyright © 2017 Elsevier B.V. All rights reserved.

SEM/EDS and optical microscopy analyses of microplastics in ocean trawl and fish guts.

Science.gov (United States)

Wang, Zhong-Min; Wagner, Jeff; Ghosal, Sutapa; Bedi, Gagandeep; Wall, Stephen

2017-12-15

Microplastic particles from Atlantic and Pacific Ocean trawls, lab-fed fish guts and ocean fish guts have been characterized using optical microscopy and SEM/EDS in terms of size, morphology, and chemistry. We assessed whether these measurements could serve as a rapid screening process for subsequent identification of the likely microplastic candidates by micro-spectroscopy. Optical microscopy enabled morphological classification of the types of particles or fibers present in the sample, as well as the quantification of particle size ranges and fiber lengths. SEM/EDS analysis was used to rule out non-plastic particles and screen the prepared samples for potential microplastic, based on their element signatures and surface characteristics. Chlorinated plastics such as polyvinyl chloride (PVC) could be easily identified with SEM/EDS due to their unique elemental signatures including chlorine, as could mineral species that are falsely identified as plastics by optical microscopy. Particle morphology determined by optical microscopy and SEM suggests the fish ingested particles contained both degradation fragments from larger plastic pieces and also manufactured microplastics. SEM images of microplastic particle surfaces revealed characteristic cracks consistent with environmental exposure, as well as pigment particles consistent with manufactured materials. Most of the microplastic surfaces in the fish guts and ocean trawls were covered with biofilms, radiolarians, and crustaceans. Many of the fish stomachs contained micro-shell pieces which visually resembled microplastics. Copyright © 2017 Elsevier B.V. All rights reserved.

A hybrid 3D SEM reconstruction method optimized for complex geologic material surfaces.

Science.gov (United States)

Yan, Shang; Adegbule, Aderonke; Kibbey, Tohren C G

2017-08-01

Reconstruction methods are widely used to extract three-dimensional information from scanning electron microscope (SEM) images. This paper presents a new hybrid reconstruction method that combines stereoscopic reconstruction with shape-from-shading calculations to generate highly-detailed elevation maps from SEM image pairs. The method makes use of an imaged glass sphere to determine the quantitative relationship between observed intensity and angles between the beam and surface normal, and the detector and surface normal. Two specific equations are derived to make use of image intensity information in creating the final elevation map. The equations are used together, one making use of intensities in the two images, the other making use of intensities within a single image. The method is specifically designed for SEM images captured with a single secondary electron detector, and is optimized to capture maximum detail from complex natural surfaces. The method is illustrated with a complex structured abrasive material, and a rough natural sand grain. Results show that the method is capable of capturing details such as angular surface features, varying surface roughness, and surface striations. Copyright © 2017 Elsevier Ltd. All rights reserved.

Novel field emission SEM column with beam deceleration technology

International Nuclear Information System (INIS)

Jiruše, Jaroslav; Havelka, Miloslav; Lopour, Filip

2014-01-01

A novel field-emission SEM column has been developed that features Beam Deceleration Mode, high-probe current and ultra-fast scanning. New detection system in the column is introduced to detect true secondary electron signal. The resolution power at low energy was doubled for conventional SEM optics and moderately improved for immersion optics. Application examples at low landing energies include change of contrast, imaging of non-conductive samples and thin layers. - Highlights: • A novel field-emission SEM column has been developed. • Implemented beam deceleration improves the SEM resolution at 1 keV two times. • New column maintains high analytical potential and wide field of view. • Detectors integrated in the column allow gaining true SE and BE signal separately. • Performance of the column is demonstrated on low energy applications

Novel field emission SEM column with beam deceleration technology

Energy Technology Data Exchange (ETDEWEB)

Jiruše, Jaroslav; Havelka, Miloslav; Lopour, Filip

2014-11-15

A novel field-emission SEM column has been developed that features Beam Deceleration Mode, high-probe current and ultra-fast scanning. New detection system in the column is introduced to detect true secondary electron signal. The resolution power at low energy was doubled for conventional SEM optics and moderately improved for immersion optics. Application examples at low landing energies include change of contrast, imaging of non-conductive samples and thin layers. - Highlights: • A novel field-emission SEM column has been developed. • Implemented beam deceleration improves the SEM resolution at 1 keV two times. • New column maintains high analytical potential and wide field of view. • Detectors integrated in the column allow gaining true SE and BE signal separately. • Performance of the column is demonstrated on low energy applications.

Fabrication of digital rainbow holograms and 3-D imaging using SEM based e-beam lithography.

Science.gov (United States)

Firsov, An; Firsov, A; Loechel, B; Erko, A; Svintsov, A; Zaitsev, S

2014-11-17

Here we present an approach for creating full-color digital rainbow holograms based on mixing three basic colors. Much like in a color TV with three luminescent points per single screen pixel, each color pixel of initial image is presented by three (R, G, B) distinct diffractive gratings in a hologram structure. Change of either duty cycle or area of the gratings are used to provide proper R, G, B intensities. Special algorithms allow one to design rather complicated 3D images (that might even be replacing each other with hologram rotation). The software developed ("RainBow") provides stability of colorization of rotated image by means of equalizing of angular blur from gratings responsible for R, G, B basic colors. The approach based on R, G, B color synthesis allows one to fabricate gray-tone rainbow hologram containing white color what is hardly possible in traditional dot-matrix technology. Budgetary electron beam lithography based on SEM column was used to fabricate practical examples of digital rainbow hologram. The results of fabrication of large rainbow holograms from design to imprinting are presented. Advantages of the EBL in comparison to traditional optical (dot-matrix) technology is considered.

Combination of FTIR and SEM for Identifying Freshwater-Cultured Pearls from Different Quality

Science.gov (United States)

Satitkune, Somruedee; Monarumit, Natthapong; Boonmee, Chakkrich; Phlayrahan, Aumaparn; Promdee, Kittiphop; Won-in, Krit

2016-03-01

The freshwater-cultured pearl ( Chamberlainia hainesiana species) is an organic gemstone mainly composed of calcium carbonate mineral including calcite, aragonite and vaterite phases. Generally, the quality of freshwater-cultured pearl is based on its luster. The high luster pearl is full of the aragonite phase without vaterite phase. On the other hand, the low luster pearl consists of aragonite and vaterite phases. These data could be proved by the Fourier Transform Infrared (FTIR) spectroscopy combined with the scanning electron microscopy (SEM). As the results, the high luster pearl similarly shows the FTIR spectrum of aragonite phase, and also, it shows the hexagonal shape of aragonite for the SEM image. On the other hand, the FTIR spectrum of low luster pearl has been pointed to the mixture component among aragonite and vaterite phases, and based on the SEM image; the irregular form is also interpreted to the mixture of aragonite and vaterite phases. This research concludes that the quality of freshwater-cultured pearls can be identified by the combination data of FTIR spectra and SEM images. These techniques are suitable for applied gemology.

Mapping the Complex Morphology of Cell Interactions with Nanowire Substrates Using FIB-SEM

DEFF Research Database (Denmark)

Wierzbicki, Rafal; Købler, Carsten; Jensen, Mikkel Ravn Boye

2013-01-01

Using high resolution focused ion beam scanning electron microscopy (FIB-SEM) we study the details of cell-nanostructure interactions using serial block face imaging. 3T3 Fibroblast cellular monolayers are cultured on flat glass as a control surface and on two types of nanostructured scaffold...... substrates made from silicon black (Nanograss) with low- and high nanowire density. After culturing for 72 hours the cells were fixed, heavy metal stained, embedded in resin, and processed with FIB-SEM block face imaging without removing the substrate. The sample preparation procedure, image acquisition...

Three dimensional rock microstructures: insights from FIB-SEM tomography

Science.gov (United States)

Drury, Martyn; Pennock, Gill; de Winter, Matthijs

2016-04-01

Most studies of rock microstructures investigate two-dimensional sections or thin slices of three dimensional grain structures. With advances of X-ray and electron tomography methods the 3-D microstructure can be(relatively) routinely investigated on scales from a few microns to cm. 3D studies are needed to investigate the connectivity of microstructures and to test the assumptions we use to calculate 3D properties from 2D sections. We have used FIB-SEM tomography to study the topology of melts in synthetic olivine rocks, 3D crystal growth microstructures, pore networks and subgrain structures. The technique uses a focused ion beam to make serial sections with a spacing of tens to hundreds of nanometers. Each section is then imaged or mapped using the electron beam. The 3D geometry of grains and subgrains can be investigated using orientation contrast or EBSD mapping. FIB-SEM tomography of rocks and minerals can be limited by charging of the uncoated surfaces exposed by the ion beam. The newest generation of FIB-SEMs have much improved low voltage imaging capability allowing high resolution charge free imaging. Low kV FIB-SEM tomography is now widely used to study the connectivity of pore networks. In-situ fluids can also be studied using cryo-FIB-SEM on frozen samples, although special freezing techniques are needed to avoid artifacts produced by ice crystallization. FIB-SEM tomography is complementary, in terms of spatial resolution and sampled volume, to TEM tomography and X-ray tomography, and the combination of these methods can cover a wide range of scales. Our studies on melt topology in synthetic olivine rocks with a high melt content show that many grain boundaries are wetted by nanometre scale melt layers that are too thin to resolve by X-ray tomography. A variety of melt layer geometries occur consistent with several mechanisms of melt layer formation. The nature of melt geometries along triple line junctions and quadruple points can be resolved

QEM*SEM: a necessary tool in the metallurgical evaluation of ore bodies

International Nuclear Information System (INIS)

Creelman, R.A.; Gottlieb, P.; Sutherland, D.; Jackson, R.

1989-01-01

The QEM*SEM system for automated image analysis of mineral samples is described. Details of the equipment are given together with information on the methods of measurement. Finally some practical applications are described where QEM*SEM has been used for the solution of metallurgical problems. 14 refs., 1 fig

SEM method for direct visual tracking of nanoscale morphological changes of platinum based electrocatalysts on fixed locations upon electrochemical or thermal treatments.

Science.gov (United States)

Zorko, Milena; Jozinović, Barbara; Bele, Marjan; Hodnik, Nejc; Gaberšček, Miran

2014-05-01

A general method for tracking morphological surface changes on a nanometer scale with scanning electron microscopy (SEM) is introduced. We exemplify the usefulness of the method by showing consecutive SEM images of an identical location before and after the electrochemical and thermal treatments of platinum-based nanoparticles deposited on a high surface area carbon. Observations reveal an insight into platinum based catalyst degradation occurring during potential cycling treatment. The presence of chloride clearly increases the rate of degradation. At these conditions the dominant degradation mechanism seems to be the platinum dissolution with some subsequent redeposition on the top of the catalyst film. By contrast, at the temperature of 60°C, under potentiostatic conditions some carbon corrosion and particle aggregation was observed. Temperature treatment simulating the annealing step of the synthesis reveals sintering of small platinum based composite aggregates into uniform spherical particles. The method provides a direct proof of induced surface phenomena occurring on a chosen location without the usual statistical uncertainty in usual, random SEM observations across relatively large surface areas. Copyright © 2014 Elsevier B.V. All rights reserved.

Seeing a Mycobacterium-Infected Cell in Nanoscale 3D: Correlative Imaging by Light Microscopy and FIB/SEM Tomography

Science.gov (United States)

Beckwith, Marianne Sandvold; Beckwith, Kai Sandvold; Sikorski, Pawel; Skogaker, Nan Tostrup

2015-01-01

Mycobacteria pose a threat to the world health today, with pathogenic and opportunistic bacteria causing tuberculosis and non-tuberculous disease in large parts of the population. Much is still unknown about the interplay between bacteria and host during infection and disease, and more research is needed to meet the challenge of drug resistance and inefficient vaccines. This work establishes a reliable and reproducible method for performing correlative imaging of human macrophages infected with mycobacteria at an ultra-high resolution and in 3D. Focused Ion Beam/Scanning Electron Microscopy (FIB/SEM) tomography is applied, together with confocal fluorescence microscopy for localization of appropriately infected cells. The method is based on an Aclar poly(chloro-tri-fluoro)ethylene substrate, micropatterned into an advantageous geometry by a simple thermomoulding process. The platform increases the throughput and quality of FIB/SEM tomography analyses, and was successfully applied to detail the intracellular environment of a whole mycobacterium-infected macrophage in 3D. PMID:26406896

Experimental investigation on 3D-SEM reconstructions of a wire gauge using stereo-pair technique

DEFF Research Database (Denmark)

Carli, Lorenzo; Genta, G.; Cantatore, Angela

2011-01-01

In this work an experimental investigation is addressed concerning 3D-SEM reconstructions obtained from the so-called stereo-pair technique. Three-dimensional topography of an object can be derived from two SEM images acquired from two different angles, through item rotation by means of the SEM...

Discopersicus n. gen., a New Member of the Family Tylenchidae Örley, 1880 with Detailed SEM Study on Two Known Species of the Genus Discotylenchus Siddiqi, 1980 (Nematoda; Tylenchidae) from Iran.

Science.gov (United States)

Yaghoubi, Ali; Pourjam, Ebrahim; Álvarez-Ortega, Sergio; Liébanas, Gracia; Atighi, Mohammad Reza; Pedram, Majid

2016-09-01

Discopersicus iranicus n. gen., n. comb., previously described from Iran as a new species under the genus Discotylenchus , is illustrated using light microscope and scanning electron microscope (SEM) observations and further studied using molecular characters. SEM studies revealed the newly proposed genus has oblique amphidial apertures on the lateral sides of the lip region. SEM images are also provided for two species of Discotylenchus , namely D. discretus and D. brevicaudatus , as the first SEM study of the genus . These results confirmed longitudinal amphidial aperture type on lateral sides of the lip region in genus Discotylenchus , as noted by Siddiqi while erecting the genus with D. discretus as the type species . Molecular phylogenetic analyses using partial small subunit (SSU) and large subunit (LSU) rDNA sequences revealed the affinity of the genus Discopersicus n. gen. with members of the subfamily Boleodorinae, as supported by morphological characters (mainly, the oblique amphidial opening).

Macromolecular 3D SEM reconstruction strategies: Signal to noise ratio and resolution

International Nuclear Information System (INIS)

Woodward, J.D.; Wepf, R.A.

2014-01-01

Three-dimensional scanning electron microscopy generates quantitative volumetric structural data from SEM images of macromolecules. This technique provides a quick and easy way to define the quaternary structure and handedness of protein complexes. Here, we apply a variety of preparation and imaging methods to filamentous actin in order to explore the relationship between resolution, signal-to-noise ratio, structural preservation and dataset size. This information can be used to define successful imaging strategies for different applications. - Highlights: • F-actin SEM datasets were collected using 8 different preparation/ imaging techniques. • Datasets were reconstructed by back projection and compared/analyzed • 3DSEM actin reconstructions can be produced with <100 views of the asymmetric unit. • Negatively stained macromolecules can be reconstructed by 3DSEM to ∼3 nm resolution

SEM technique for imaging and measuring electronic transport in nanocomposites based on electric field induced contrast

Science.gov (United States)

Jesse, Stephen [Knoxville, TN; Geohegan, David B [Knoxville, TN; Guillorn, Michael [Brooktondale, NY

2009-02-17

Methods and apparatus are described for SEM imaging and measuring electronic transport in nanocomposites based on electric field induced contrast. A method includes mounting a sample onto a sample holder, the sample including a sample material; wire bonding leads from the sample holder onto the sample; placing the sample holder in a vacuum chamber of a scanning electron microscope; connecting leads from the sample holder to a power source located outside the vacuum chamber; controlling secondary electron emission from the sample by applying a predetermined voltage to the sample through the leads; and generating an image of the secondary electron emission from the sample. An apparatus includes a sample holder for a scanning electron microscope having an electrical interconnect and leads on top of the sample holder electrically connected to the electrical interconnect; a power source and a controller connected to the electrical interconnect for applying voltage to the sample holder to control the secondary electron emission from a sample mounted on the sample holder; and a computer coupled to a secondary electron detector to generate images of the secondary electron emission from the sample.

Application of SEM and EDX in studying biomineralization in plant tissues.

Science.gov (United States)

He, Honghua; Kirilak, Yaowanuj

2014-01-01

This chapter describes protocols using formalin-acetic acid-alcohol (FAA) to fix plant tissues for studying biomineralization by means of scanning electron microscopy (SEM) and qualitative energy-dispersive X-ray microanalysis (EDX). Specimen preparation protocols for SEM and EDX mainly include fixation, dehydration, critical point drying (CPD), mounting, and coating. Gold-coated specimens are used for SEM imaging, while gold- and carbon-coated specimens are prepared for qualitative X-ray microanalyses separately to obtain complementary information on the elemental compositions of biominerals. During the specimen preparation procedure for SEM, some biominerals may be dislodged or scattered, making it difficult to determine their accurate locations, and light microscopy is used to complement SEM studies. Specimen preparation protocols for light microscopy generally include fixation, dehydration, infiltration and embedding with resin, microtome sectioning, and staining. In addition, microwave processing methods are adopted here to speed up the specimen preparation process for both SEM and light microscopy.

Cross-Sectional Information on Pore Structure and Element Distribution of Sediment Particles by SEM and EDS

Directory of Open Access Journals (Sweden)

Minghong Chen

2017-01-01

Full Text Available The interaction between pollutants and sediment particles often occurs on the particle surface, so surface properties directly affect surface reaction. The physical and chemical processes occurring on sediment particle surfaces are microscopic processes and as such need to be studied from a microscopic perspective. In this study, field emission scanning electron microscopy (SEM and energy dispersive X-ray spectrometer (EDS were adopted to observe and analyze the pore structure and element distribution of sediment particles. In particular, a special method of sample preparation was used to achieve the corresponding cross-sectional information of sediment particles. Clear images of a particle profile and pore microstructure were obtained by high-resolution SEM, while element distribution maps of sediment particles were obtained by EDS. The results provide an intuitive understanding of the internal microenvironment and external behavior of sediment particles, in addition to revealing a significant role of pore microstructure in the adsorption and desorption of pollutants. Thus, a combination of different experimental instruments and observation methods can provide real images and information on microscopic pore structure and element distribution of sediment particles. These results should help to improve our understanding of sediment dynamics and its environmental effects.

Fuzzy Control and Connected Region Marking Algorithm-Based SEM Nanomanipulation

Directory of Open Access Journals (Sweden)

Dongjie Li

2012-01-01

Full Text Available The interactive nanomanipulation platform is established based on fuzzy control and connected region marking (CRM algorithm in SEM. The 3D virtual nanomanipulation model is developed to make up the insufficiency of the 2D SEM image information, which provides the operator with depth and real-time visual feedback information to guide the manipulation. The haptic device Omega3 is used as the master to control the 3D motion of the nanopositioner in master-slave mode and offer the force sensing to the operator controlled with fuzzy control algorithm. Aiming at sensing of force feedback during the nanomanipulation, the collision detection method of the virtual nanomanipulation model and the force rending model are studied to realize the force feedback of nanomanipulation. The CRM algorithm is introduced to process the SEM image which provides effective position data of the objects for updating the virtual environment (VE, and relevant issues such as calibration and update rate of VE are also discussed. Finally, the performance of the platform is validated by the ZnO nanowire manipulation experiments.

A methodological basis for SEM autoradiography: biosynthesis and radioligand binding

International Nuclear Information System (INIS)

Cheng, G.; Hodges, G.M.; Trejdosiewicz, L.K.

1985-01-01

A method is described for scanning electron microscope (SEM) autoradiography whereby preservation of high resolution cell surface details is retained together with degelatination of the emulsion without gross loss or redistribution of silver grains. This method should provide a convenient medium-sized marker for SEM (using secondary, backscattered electron and X-ray imaging) topographic studies of biosynthesized molecules, and of cell surface receptors and antigens, using indirect or direct labelling procedures with radio-labelled ligands. (author)

Extraction of topographic and material contrasts on surfaces from SEM images obtained by energy filtering detection with low-energy primary electrons

International Nuclear Information System (INIS)

Nagoshi, Masayasu; Aoyama, Tomohiro; Sato, Kaoru

2013-01-01

Secondary electron microscope (SEM) images have been obtained for practical materials using low primary electron energies and an in-lens type annular detector with changing negative bias voltage supplied to a grid placed in front of the detector. The kinetic-energy distribution of the detected electrons was evaluated by the gradient of the bias-energy dependence of the brightness of the images. This is divided into mainly two parts at about 500 V, high and low brightness in the low- and high-energy regions, respectively and shows difference among the surface regions having different composition and topography. The combination of the negative grid bias and the pixel-by-pixel image subtraction provides the band-pass filtered images and extracts the material and topographic information of the specimen surfaces. -- Highlights: ► Scanning electron (SE) images contain many kind of information on material surfaces. ► We investigate energy-filtered SE images for practical materials. ► The brightness of the images is divided into two parts by the bias voltage. ► Topographic and material contrasts are extracted by subtracting the filtered images.

SEM based overlay measurement between resist and buried patterns

Science.gov (United States)

Inoue, Osamu; Okagawa, Yutaka; Hasumi, Kazuhisa; Shao, Chuanyu; Leray, Philippe; Lorusso, Gian; Baudemprez, Bart

2016-03-01

With the continuous shrink in pattern size and increased density, overlay control has become one of the most critical issues in semiconductor manufacturing. Recently, SEM based overlay of AEI (After Etch Inspection) wafer has been used for reference and optimization of optical overlay (both Image Based Overlay (IBO) and Diffraction Based Overlay (DBO)). Overlay measurement at AEI stage contributes monitor and forecast the yield after formation by etch and calibrate optical measurement tools. however those overlay value seems difficult directly for feedback to a scanner. Therefore, there is a clear need to have SEM based overlay measurements of ADI (After Develop Inspection) wafers in order to serve as reference for optical overlay and make necessary corrections before wafers go to etch. Furthermore, to make the corrections as accurate as possible, actual device like feature dimensions need to be measured post ADI. This device size measurement is very unique feature of CDSEM , which can be measured with smaller area. This is currently possible only with the CD-SEM. This device size measurement is very unique feature of CD-SEM , which can be measured with smaller area. In this study, we assess SEM based overlay measurement of ADI and AEI wafer by using a sample from an N10 process flow. First, we demonstrate SEM based overlay performance at AEI by using dual damascene process for Via 0 (V0) and metal 1 (M1) layer. We also discuss the overlay measurements between litho-etch-litho stages of a triple patterned M1 layer and double pattern V0. Second, to illustrate the complexities in image acquisition and measurement we will measure overlay between M1B resist and buried M1A-Hard mask trench. Finally, we will show how high accelerating voltage can detect buried pattern information by BSE (Back Scattering Electron). In this paper we discuss the merits of this method versus standard optical metrology based corrections.

Relation of expansion due to alkali silica reaction to the degree of reaction measured by SEM image analysis

International Nuclear Information System (INIS)

Haha, M. Ben; Gallucci, E.; Guidoum, A.; Scrivener, K.L.

2007-01-01

Scanning Electron Microscopy Image Analysis (SEM-IA) was used to quantify the degree of alkali silica reaction in affected microbars, mortar and concrete prisms. It was found that the degree of reaction gave a unique correlation with the macroscopic expansion for three different aggregates, stored at three temperatures and with two levels of alkali. The relationships found for the concretes and the mortars overlap when normalised by the aggregate content. This relationship seems to be linear up to a critical reaction degree which coincides with crack initiation within the reactive aggregates

Recent improvement of a FIB-SEM serial-sectioning method for precise 3D image reconstruction - application of the orthogonally-arranged FIB-SEM.

Science.gov (United States)

Hara, Toru

2014-11-01

IntroductionWe installed the first "orthogonally-arranged" FIB-SEM in 2011. The most characteristic point of this instrument is that the FIB and SEM columns are perpendicularly mounted; this is specially designed to obtain a serial-sectioning dataset more accurately and precisely with higher contrast and higher spatial resolution compare to other current FIB-SEMs [1]. Since the installation in 2011, we have developed the hardware and methodology of the serial-sectioning based on this orthogonal FIB-SEM. In order to develop this technique, we have widely opened this instrument to every researcher of all fields. In the presentation, I would like to introduce some of application results that are obtained by users of this instrument. The characteristic points of the orthogonal systemFigure 1 shows a difference between the standard and the orthogonal FIB-SEM systems: In the standard system, shown in Fig.1(a), optical axes of a FIB and a SEM crosses around 60deg., while in the orthogonal system (Fig.1(b)), they are perpendicular to each other. The standard arrangement (a) is certainly suitable for TEM lamellae preparation etc. because the FIB and the SEM can see the same position simultaneously. However, for a serial-sectioning, it is not to say the best arrangement. One of the reasons is that the sliced plane by the FIB is not perpendicular to the electron beam so that the background contrast is not uniform and observed plane is distorted. On the other hand, in case of the orthogonally-arranged system,(b), these problems are resolved. In addition, spatial resolution can keep high enough even in a low accelerating voltage (e.g. 500V) because a working distance is set very small, 2mm. From these special design, we can obtain the serial-sectioning dataset from rather wide area (∼100um) with high spatial resolution (Max. 2×2×2nm). As this system has many kinds of detectors: SE, ET, Backscatter Electron(Energy-selective), EDS, EBSD, STEM(BF&ADF), with Ar+ ion-gun and a

A multimodal microcharacterisation of trace-element zonation and crystallographic orientation in natural cassiterite by combining cathodoluminescence, EBSD, EPMA and contribution of confocal Raman-in-SEM imaging.

Science.gov (United States)

Wille, G; Lerouge, C; Schmidt, U

2018-01-16

In cassiterite, tin is associated with metals (titanium, niobium, tantalum, indium, tungsten, iron, manganese, mercury). Knowledge of mineral chemistry and trace-element distribution is essential for: the understanding of ore formation, the exploration phase, the feasibility of ore treatment, and disposal/treatment of tailings after the exploitation phase. However, the availability of analytical methods make these characterisations difficult. We present a multitechnical approach to chemical and structural data that includes scanning electron microscopy (SEM)-based imaging and microanalysis techniques such as: secondary and backscattered electrons, cathodoluminescence (CL), electron probe microanalyser (EPMA), electron backscattered diffraction (EBSD) and confocal Raman-imaging integrated in a SEM (RISE). The presented results show the complementarity of the used analytical techniques. SEM, CL, EBSD, EPMA provide information from the interaction of an electron beam with minerals, leading to atomistic information about their composition, whereas RISE, Raman spectroscopy and imaging completes the studies with information about molecular vibrations, which are sensitive to structural modifications of the minerals. The correlation of Raman bands with the presence/absence of Nb, Ta, Fe (heterovalent substitution) and Ti (homovalent substitution) is established at a submicrometric scale. Combination of the different techniques makes it possible to establish a direct link between chemical and crystallographic data of cassiterite. © 2018 The Authors Journal of Microscopy © 2018 Royal Microscopical Society.

Fractal analysis of SEM images and mercury intrusion porosimetry data for the microstructural characterization of microcrystalline cellulose-based pellets

International Nuclear Information System (INIS)

Gomez-Carracedo, A.; Alvarez-Lorenzo, C.; Coca, R.; Martinez-Pacheco, R.; Concheiro, A.; Gomez-Amoza, J.L.

2009-01-01

The microstructure of theophylline pellets prepared from microcrystalline cellulose, carbopol and dicalcium phosphate dihydrate, according to a mixture design, was characterized using textural analysis of gray-level scanning electron microscopy (SEM) images and thermodynamic analysis of the cumulative pore volume distribution obtained by mercury intrusion porosimetry. Surface roughness evaluated in terms of gray-level non-uniformity and fractal dimension of pellet surface depended on agglomeration phenomena during extrusion/spheronization. Pores at the surface, mainly 1-15 μm in diameter, determined both the mechanism and the rate of theophylline release, and a strong negative correlation between the fractal geometry and the b parameter of the Weibull function was found for pellets containing >60% carbopol. Theophylline mean dissolution time from these pellets was about two to four times greater. Textural analysis of SEM micrographs and fractal analysis of mercury intrusion data are complementary techniques that enable complete characterization of multiparticulate drug dosage forms

Multi-scale characterization by FIB-SEM/TEM/3DAP.

Science.gov (United States)

Ohkubo, T; Sepehri-Amin, H; Sasaki, T T; Hono, K

2014-11-01

In order to improve properties of functional materials, it is important to understand the relation between the structure and the properties since the structure has large effect to the properties. This can be done by using multi-scale microstructure analysis from macro-scale to nano and atomic scale. Scanning electron microscope (SEM) equipped with focused ion beam (FIB), transmission electron microscope (TEM) and 3D atom probe (3DAP) are complementary analysis tools making it possible to know the structure and the chemistry from micron to atomic resolution. SEM gives us overall microstructural and chemical information by various kinds of detectors such as secondary electron, backscattered electron, EDS and EBSD detectors. Also, it is possible to analyze 3D structure and chemistry via FIB serial sectioning. In addition, using TEM we can focus on desired region to get more complementary information from HRTEM/STEM/Lorentz images, SAED/NBD patterns and EDS/EELS to see the detail micro or nano-structure and chemistry. Especially, combination of probe Cs corrector and split EDS detectors with large detector size enable us to analyze the atomic scale elemental distribution. Furthermore, if the specimen has a complicated 3D nanostructure, or we need to analyze light elements such as hydrogen, lithium or boron, 3DAP can be used as the only technique which can visualize and analyze distribution of all constituent atoms of our materials within a few hundreds nm area. Hence, site-specific sample preparation using FIB/SEM is necessary to get desired information from region of interest. Therefore, this complementary analysis combination works very well to understand the detail of materials.In this presentation, we will show the analysis results obtained from some of functional materials by Carl Zeiss CrossBeam 1540EsB FIB/SEM, FEI Tecnai G(2) F30, Titan G2 80-200 TEMs and locally build laser assisted 3DAP. As the one of the example, result of multi-scale characterization for

Automated CD-SEM recipe creation technology for mass production using CAD data

Science.gov (United States)

Kawahara, Toshikazu; Yoshida, Masamichi; Tanaka, Masashi; Ido, Sanyu; Nakano, Hiroyuki; Adachi, Naokaka; Abe, Yuichi; Nagatomo, Wataru

2011-03-01

Critical Dimension Scanning Electron Microscope (CD-SEM) recipe creation needs sample preparation necessary for matching pattern registration, and recipe creation on CD-SEM using the sample, which hinders the reduction in test production cost and time in semiconductor manufacturing factories. From the perspective of cost reduction and improvement of the test production efficiency, automated CD-SEM recipe creation without the sample preparation and the manual operation has been important in the production lines. For the automated CD-SEM recipe creation, we have introduced RecipeDirector (RD) that enables the recipe creation by using Computer-Aided Design (CAD) data and text data that includes measurement information. We have developed a system that automatically creates the CAD data and the text data necessary for the recipe creation on RD; and, for the elimination of the manual operation, we have enhanced RD so that all measurement information can be specified in the text data. As a result, we have established an automated CD-SEM recipe creation system without the sample preparation and the manual operation. For the introduction of the CD-SEM recipe creation system using RD to the production lines, the accuracy of the pattern matching was an issue. The shape of design templates for the matching created from the CAD data was different from that of SEM images in vision. Thus, a development of robust pattern matching algorithm that considers the shape difference was needed. The addition of image processing of the templates for the matching and shape processing of the CAD patterns in the lower layer has enabled the robust pattern matching. This paper describes the automated CD-SEM recipe creation technology for the production lines without the sample preparation and the manual operation using RD applied in Sony Semiconductor Kyusyu Corporation Kumamoto Technology Center (SCK Corporation Kumamoto TEC).

Extraction of topographic and material contrasts on surfaces from SEM images obtained by energy filtering detection with low-energy primary electrons.

Science.gov (United States)

Nagoshi, Masayasu; Aoyama, Tomohiro; Sato, Kaoru

2013-01-01

Secondary electron microscope (SEM) images have been obtained for practical materials using low primary electron energies and an in-lens type annular detector with changing negative bias voltage supplied to a grid placed in front of the detector. The kinetic-energy distribution of the detected electrons was evaluated by the gradient of the bias-energy dependence of the brightness of the images. This is divided into mainly two parts at about 500 V, high and low brightness in the low- and high-energy regions, respectively and shows difference among the surface regions having different composition and topography. The combination of the negative grid bias and the pixel-by-pixel image subtraction provides the band-pass filtered images and extracts the material and topographic information of the specimen surfaces. Copyright © 2012 Elsevier B.V. All rights reserved.

Evaluation of bone formation in calcium phosphate scaffolds with μCT-method validation using SEM.

Science.gov (United States)

Lewin, S; Barba, A; Persson, C; Franch, J; Ginebra, M-P; Öhman-Mägi, C

2017-10-05

There is a plethora of calcium phosphate (CaP) scaffolds used as synthetic substitutes to bone grafts. The scaffold performance is often evaluated from the quantity of bone formed within or in direct contact with the scaffold. Micro-computed tomography (μCT) allows three-dimensional evaluation of bone formation inside scaffolds. However, the almost identical x-ray attenuation of CaP and bone obtrude the separation of these phases in μCT images. Commonly, segmentation of bone in μCT images is based on gray scale intensity, with manually determined global thresholds. However, image analysis methods, and methods for manual thresholding in particular, lack standardization and may consequently suffer from subjectivity. The aim of the present study was to provide a methodological framework for addressing these issues. Bone formation in two types of CaP scaffold architectures (foamed and robocast), obtained from a larger animal study (a 12 week canine animal model) was evaluated by μCT. In addition, cross-sectional scanning electron microscopy (SEM) images were acquired as references to determine thresholds and to validate the result. μCT datasets were registered to the corresponding SEM reference. Global thresholds were then determined by quantitatively correlating the different area fractions in the μCT image, towards the area fractions in the corresponding SEM image. For comparison, area fractions were also quantified using global thresholds determined manually by two different approaches. In the validation the manually determined thresholds resulted in large average errors in area fraction (up to 17%), whereas for the evaluation using SEM references, the errors were estimated to be less than 3%. Furthermore, it was found that basing the thresholds on one single SEM reference gave lower errors than determining them manually. This study provides an objective, robust and less error prone method to determine global thresholds for the evaluation of bone formation in

Viewing Integrated-Circuit Interconnections By SEM

Science.gov (United States)

Lawton, Russel A.; Gauldin, Robert E.; Ruiz, Ronald P.

1990-01-01

Back-scattering of energetic electrons reveals hidden metal layers. Experiment shows that with suitable operating adjustments, scanning electron microscopy (SEM) used to look for defects in aluminum interconnections in integrated circuits. Enables monitoring, in situ, of changes in defects caused by changes in temperature. Gives truer picture of defects, as etching can change stress field of metal-and-passivation pattern, causing changes in defects.

CD-SEM real time bias correction using reference metrology based modeling

Science.gov (United States)

Ukraintsev, V.; Banke, W.; Zagorodnev, G.; Archie, C.; Rana, N.; Pavlovsky, V.; Smirnov, V.; Briginas, I.; Katnani, A.; Vaid, A.

2018-03-01

Accuracy of patterning impacts yield, IC performance and technology time to market. Accuracy of patterning relies on optical proximity correction (OPC) models built using CD-SEM inputs and intra die critical dimension (CD) control based on CD-SEM. Sub-nanometer measurement uncertainty (MU) of CD-SEM is required for current technologies. Reported design and process related bias variation of CD-SEM is in the range of several nanometers. Reference metrology and numerical modeling are used to correct SEM. Both methods are slow to be used for real time bias correction. We report on real time CD-SEM bias correction using empirical models based on reference metrology (RM) data. Significant amount of currently untapped information (sidewall angle, corner rounding, etc.) is obtainable from SEM waveforms. Using additional RM information provided for specific technology (design rules, materials, processes) CD extraction algorithms can be pre-built and then used in real time for accurate CD extraction from regular CD-SEM images. The art and challenge of SEM modeling is in finding robust correlation between SEM waveform features and bias of CD-SEM as well as in minimizing RM inputs needed to create accurate (within the design and process space) model. The new approach was applied to improve CD-SEM accuracy of 45 nm GATE and 32 nm MET1 OPC 1D models. In both cases MU of the state of the art CD-SEM has been improved by 3x and reduced to a nanometer level. Similar approach can be applied to 2D (end of line, contours, etc.) and 3D (sidewall angle, corner rounding, etc.) cases.

GAGG:ce single crystalline films: New perspective scintillators for electron detection in SEM.

Science.gov (United States)

Bok, Jan; Lalinský, Ondřej; Hanuš, Martin; Onderišinová, Zuzana; Kelar, Jakub; Kučera, Miroslav

2016-04-01

Single crystal scintillators are frequently used for electron detection in scanning electron microscopy (SEM). We report gadolinium aluminum gallium garnet (GAGG:Ce) single crystalline films as a new perspective scintillators for the SEM. For the first time, the epitaxial garnet films were used in a practical application: the GAGG:Ce scintillator was incorporated into a SEM scintillation electron detector and it showed improved image quality. In order to prove the GAGG:Ce quality accurately, the scintillation properties were examined using electron beam excitation and compared with frequently used scintillators in the SEM. The results demonstrate excellent emission efficiency of the GAGG:Ce single crystalline films together with their very fast scintillation decay useful for demanding SEM applications. Copyright © 2016 Elsevier B.V. All rights reserved.

SEM Anthology

Science.gov (United States)

Rodgers, Michelle; Zimar, Heather

2004-01-01

The "SEM Anthology" is a compilation of articles by more than 30 enrollment management professionals from a variety of institutions across the country. This collection, which has appeared in SEM Monthly over the past year, chronicles Strategic Enrollment Management efforts at campuses nationwide. The book illustrates the successes and challenges…

SEM Investigation of Superheater Deposits from Biomass-Fired Boilers

DEFF Research Database (Denmark)

Jensen, Peter Arendt; Frandsen, Flemming; Hansen, Jørn

2004-01-01

, mature superheater deposit samples were extracted from two straw-fired boilers, Masnedø and Ensted, with fuel inputs of 33 MWth and 100 MWth, respectively. SEM (scanning electron microscopy) images and EDX (energy dispersive X-ray) analyses were performed on the deposit samples. Different strategies...

Critical factors in SEM 3D stereo microscopy

International Nuclear Information System (INIS)

Marinello, F; Savio, E; Bariani, P; Horsewell, A; De Chiffre, L

2008-01-01

This work addresses dimensional measurements performed with the scanning electron microscope (SEM) using 3D reconstruction of surface topography through stereo-photogrammetry. The paper presents both theoretical and experimental investigations, on the effects of instrumental variables and measurement parameters on reconstruction accuracy. Investigations were performed on a novel sample, specifically developed and implemented for the tests. The description is based on the model function introduced by Piazzesi and adapted for eucentrically tilted stereopairs. Two main classes of influencing factors are recognized: the first one is related to the measurement operation and the instrument set-up; the second concerns the quality of scanned images and represents the major criticality in the application of SEMs for 3D characterizations

Separating topographical and chemical analysis of nanostructure of polymer composite in low voltage SEM

International Nuclear Information System (INIS)

Wan, Q; Plenderleith, R A; Claeyssens, F; Rodenburg, C; Dapor, M; Rimmer, S

2015-01-01

The possibility of separating the topographical and chemical information in a polymer nano-composite using low-voltage SEM imaging is demonstrated, when images are acquired with a Concentric Backscattered (CBS) detector. This separation of chemical and topographical information is based on the different angular distribution of electron scattering which were calculated using a Monte Carlo simulation. The simulation based on angular restricted detection was applied to a semi-branched PNIPAM/PEGDA interpenetration network for which a linear relationship of topography SEM contrast and feature height data was observed. (paper)

Staining plastic blocks with triiodide to image cells and soft tissues in backscattered electron SEM of skeletal and dental tissues

Directory of Open Access Journals (Sweden)

A Boyde

2012-07-01

Full Text Available Backscattered electron scanning electron microscopy (BSE SEM is an invaluable method for studying the histology of the hard, mineralised components of poly-methyl methacrylate (PMMA or other resin embedded skeletal and dental tissues. Intact tissues are studied in micro-milled or polished block faces with an electron-optical section thickness of the order of a half to one micron and with the area of the section as big as a whole – large or small – bone organ. However, BSE SEM does not give information concerning the distribution of uncalcified, ‘soft’, cellular and extracellular matrix components. This can be obtained by confocal microscopy of the same block and the two sorts of images merged but the blocks have to be studied in two microscope systems. The present work shows a new, simple and economic approach to visualising both components by using the triiodide ion in Lugol's iodine solution to stain the block surface prior to the application of any conductive coating – and the latter can be omitted if charging is suppressed by use of poor vacuum conditions in the SEM sample chamber. The method permits the use of archival tissue, and it will be valuable in studies of both normal growth and development and pathological changes in bones and joints, including osteoporosis and osteoarthritis, and tissue adaptation to implants.

Comparison of 3D cellular imaging techniques based on scanned electron probes: Serial block face SEM vs. Axial bright-field STEM tomography.

Science.gov (United States)

McBride, E L; Rao, A; Zhang, G; Hoyne, J D; Calco, G N; Kuo, B C; He, Q; Prince, A A; Pokrovskaya, I D; Storrie, B; Sousa, A A; Aronova, M A; Leapman, R D

2018-06-01

Microscopies based on focused electron probes allow the cell biologist to image the 3D ultrastructure of eukaryotic cells and tissues extending over large volumes, thus providing new insight into the relationship between cellular architecture and function of organelles. Here we compare two such techniques: electron tomography in conjunction with axial bright-field scanning transmission electron microscopy (BF-STEM), and serial block face scanning electron microscopy (SBF-SEM). The advantages and limitations of each technique are illustrated by their application to determining the 3D ultrastructure of human blood platelets, by considering specimen geometry, specimen preparation, beam damage and image processing methods. Many features of the complex membranes composing the platelet organelles can be determined from both approaches, although STEM tomography offers a higher ∼3 nm isotropic pixel size, compared with ∼5 nm for SBF-SEM in the plane of the block face and ∼30 nm in the perpendicular direction. In this regard, we demonstrate that STEM tomography is advantageous for visualizing the platelet canalicular system, which consists of an interconnected network of narrow (∼50-100 nm) membranous cisternae. In contrast, SBF-SEM enables visualization of complete platelets, each of which extends ∼2 µm in minimum dimension, whereas BF-STEM tomography can typically only visualize approximately half of the platelet volume due to a rapid non-linear loss of signal in specimens of thickness greater than ∼1.5 µm. We also show that the limitations of each approach can be ameliorated by combining 3D and 2D measurements using a stereological approach. Copyright © 2018. Published by Elsevier Inc.

SEM method for direct visual tracking of nanoscale morphological changes of platinum based electrocatalysts on fixed locations upon electrochemical or thermal treatments

Energy Technology Data Exchange (ETDEWEB)

Zorko, Milena [National Institute of Chemistry, Hajdrihova 19, Ljubljana (Slovenia); Centre of Excellence for Low-Carbon Technologies, Hajdrihova 19, Ljubljana (Slovenia); Jozinović, Barbara [Centre of Excellence for Low-Carbon Technologies, Hajdrihova 19, Ljubljana (Slovenia); Bele, Marjan [National Institute of Chemistry, Hajdrihova 19, Ljubljana (Slovenia); Centre of Excellence for Low-Carbon Technologies, Hajdrihova 19, Ljubljana (Slovenia); Hodnik, Nejc, E-mail: nejc.hodnik@ki.si [National Institute of Chemistry, Hajdrihova 19, Ljubljana (Slovenia); Gaberšček, Miran [National Institute of Chemistry, Hajdrihova 19, Ljubljana (Slovenia); Centre of Excellence for Low-Carbon Technologies, Hajdrihova 19, Ljubljana (Slovenia)

2014-05-01

A general method for tracking morphological surface changes on a nanometer scale with scanning electron microscopy (SEM) is introduced. We exemplify the usefulness of the method by showing consecutive SEM images of an identical location before and after the electrochemical and thermal treatments of platinum-based nanoparticles deposited on a high surface area carbon. Observations reveal an insight into platinum based catalyst degradation occurring during potential cycling treatment. The presence of chloride clearly increases the rate of degradation. At these conditions the dominant degradation mechanism seems to be the platinum dissolution with some subsequent redeposition on the top of the catalyst film. By contrast, at the temperature of 60 °C, under potentiostatic conditions some carbon corrosion and particle aggregation was observed. Temperature treatment simulating the annealing step of the synthesis reveals sintering of small platinum based composite aggregates into uniform spherical particles. The method provides a direct proof of induced surface phenomena occurring on a chosen location without the usual statistical uncertainty in usual, random SEM observations across relatively large surface areas. - Highlights: • A new SEM method for observations of identical locations. • Nanoscale morphological consecutive changes on identical locations. • Electrochemical and thermal treatments on platinum based nanoparticles. • Potential cycling induces platinum dissolution with redeposition on top of the film. • At 1.4 V vs. RHE and 60 °C carbon corrosion and particle aggregation is observed.

Featured Image: Revealing Hidden Objects with Color

Science.gov (United States)

Kohler, Susanna

2018-02-01

Stunning color astronomical images can often be the motivation for astronomers to continue slogging through countless data files, calculations, and simulations as we seek to understand the mysteries of the universe. But sometimes the stunning images can, themselves, be the source of scientific discovery. This is the case with the below image of Lynds Dark Nebula 673, located in the Aquila constellation, that was captured with the Mayall 4-meter telescope at Kitt Peak National Observatory by a team of scientists led by Travis Rector (University of Alaska Anchorage). After creating the image with a novel color-composite imaging method that reveals faint H emission (visible in red in both images here), Rector and collaborators identified the presence of a dozen new Herbig-Haro objects small cloud patches that are caused when material is energetically flung out from newly born stars. The image adapted above shows three of the new objects, HH 118789, aligned with two previously known objects, HH 32 and 332 suggesting they are driven by the same source. For more beautiful images and insight into the authors discoveries, check out the article linked below!Full view of Lynds Dark Nebula 673. Click for the larger view this beautiful composite image deserves! [T.A. Rector (University of Alaska Anchorage) and H. Schweiker (WIYN and NOAO/AURA/NSF)]CitationT. A. Rector et al 2018 ApJ 852 13. doi:10.3847/1538-4357/aa9ce1

Orientation mapping by transmission-SEM with an on-axis detector

International Nuclear Information System (INIS)

Fundenberger, J.J.; Bouzy, E.; Goran, D.; Guyon, J.; Yuan, H.; Morawiec, A.

2016-01-01

Conventional orientation mapping in a scanning electron microscope (SEM) is a valuable technique for characterizing crystalline materials, but its application to ultrafine or nano-grain materials is limited by its spatial resolution. The resolution can be increased by collecting transmission diffraction patterns in SEM. In previous works, such patterns were collected using off-axis detectors in nearly vertical position. To avoid some drawbacks of such arrangement, a new configuration was devised in which the scintillator is located underneath the thin foil on the optical axis of the microscope, and the light is reflected towards the camera by a mirror. This simple configuration gives intense patterns even at very low probe currents, and can be potentially used for collecting maps of relatively high spatial resolution. Example maps reveal details with dimensions of about 5 nm. Because of its resolution and geometric simplicity, the proposed configuration will open new opportunities in SEM-based characterization of nanocrystalline materials. - Highlights: • New experimental configuration for SEM-based orientation mapping is presented. • The geometry of recording transmission Kikuchi patterns in SEM is simplified. • The new configuration allows for reaching relatively high spatial resolution.

Direct comparison of AFM and SEM measurements on the same set of nanoparticles

International Nuclear Information System (INIS)

Delvallée, A; Feltin, N; Ducourtieux, S; Trabelsi, M; Hochepied, J F

2015-01-01

This article is the first step in the development of a hybrid metrology combining AFM and SEM techniques for measuring the dimensions of a nanoparticle population in 3D space (X,Y,Z). This method exploits the strengths of each technique on the same set of nanoparticles. AFM is used for measuring the nanoparticle height and the measurements along X and Y axes are deduced from SEM images. A sampling method is proposed in order to obtain the best deposition conditions of SiO 2 and gold nanoparticles on mica or silicon substrates. Only the isolated nanoparticles are taken into account in the histogram of size distribution. Moreover, a semi-automatic Matlab routine has also been developed to process the AFM and SEM images, measure and count the nanoparticles. This routine allows the user to exclusively select the isolated nanoparticles through a control interface. The measurements have been performed on spherical-like nanoparticles to test the method by comparing the results obtained with both techniques. (paper)

Applications of Real Space Crystallography in Characterization of Dislocations in Geological Materials in a Scanning Electron Microscope (SEM)

Science.gov (United States)

Kaboli, S.; Burnley, P. C.

2017-12-01

Imaging and characterization of defects in crystalline materials is of significant importance in various disciplines including geoscience, materials science, and applied physics. Linear defects such as dislocations and planar defects such as twins and stacking faults, strongly influence many of the properties of crystalline materials and also reflect the conditions and degree of deformation. Dislocations have been conventionally imaged in thin foils in a transmission electron microscope (TEM). Since the development of field emission scanning electron microscopes (FE-SEM) with high gun brightness and small spot size, extensive efforts have been dedicated to the imaging and characterization of dislocations in semi-conductors using electron channeling contrast imaging (ECCI) in the SEM. The obvious advantages of using SEM over TEM include easier and non-destructive sample preparation and a large field of view enabling statistical examination of the density and distribution of dislocations and other defects. In this contribution, we extend this technique to geological materials and introduce the Real Space Crystallography methodology for imaging and complete characterization of dislocations based on bend contour contrast obtained by ECCI in FE-SEM. Bend contours map out the distortion in the crystal lattice across a deformed grain. The contrast of dislocations is maximum in the vicinity of bend contours where crystal planes diffract at small and positive deviations from the Bragg positions (as defined by Bragg's law of electron diffraction). Imaging is performed in a commercial FE-SEM equipped with a standard silicon photodiode backscattered (BSE) detector and an electron backscatter diffraction (EBSD) system for crystal orientation measurements. We demonstrate the practice of this technique in characterization of a number of geological materials in particular quartz, forsterite olivine and corundum, experimentally deformed at high pressure-temperature conditions. This

A Miniaturized Variable Pressure Scanning Electron Microscope (MVP-SEM) for In-Situ Mars Surface Sample Analysis

Science.gov (United States)

Edmunson, J.; Gaskin, J. A.; Jerman, G. A.; Harvey, R. P.; Doloboff, I. J.; Neidholdt, E. L.

2016-01-01

The Miniaturized Variable Pressure Scanning Electron Microscope (MVP-SEM) project, funded by the NASA Planetary Instrument Concepts for the Advancement of Solar System Observations (PICASSO) Research Opportunities in Space and Earth Sciences (ROSES), will build upon previous miniaturized SEM designs and recent advancements in variable pressure SEM's to design and build a SEM to complete analyses of samples on the surface of Mars using the atmosphere as an imaging medium. This project is a collaboration between NASA Marshall Space Flight Center (MSFC), the Jet Propulsion Laboratory (JPL), electron gun and optics manufacturer Applied Physics Technologies, and small vacuum system manufacturer Creare. Dr. Ralph Harvery and environmental SEM (ESEM) inventor Dr. Gerry Danilatos serve as advisors to the team. Variable pressure SEMs allow for fine (nm-scale) resolution imaging and micron-scale chemical study of materials without sample preparation (e.g., carbon or gold coating). Charging of a sample is reduced or eliminated by the gas surrounding the sample. It is this property of ESEMs that make them ideal for locations where sample preparation is not yet feasible, such as the surface of Mars. In addition, the lack of sample preparation needed here will simplify the sample acquisition process and allow caching of the samples for future complementary payload use.

Multidimensionally encoded magnetic resonance imaging.

Science.gov (United States)

Lin, Fa-Hsuan

2013-07-01

Magnetic resonance imaging (MRI) typically achieves spatial encoding by measuring the projection of a q-dimensional object over q-dimensional spatial bases created by linear spatial encoding magnetic fields (SEMs). Recently, imaging strategies using nonlinear SEMs have demonstrated potential advantages for reconstructing images with higher spatiotemporal resolution and reducing peripheral nerve stimulation. In practice, nonlinear SEMs and linear SEMs can be used jointly to further improve the image reconstruction performance. Here, we propose the multidimensionally encoded (MDE) MRI to map a q-dimensional object onto a p-dimensional encoding space where p > q. MDE MRI is a theoretical framework linking imaging strategies using linear and nonlinear SEMs. Using a system of eight surface SEM coils with an eight-channel radiofrequency coil array, we demonstrate the five-dimensional MDE MRI for a two-dimensional object as a further generalization of PatLoc imaging and O-space imaging. We also present a method of optimizing spatial bases in MDE MRI. Results show that MDE MRI with a higher dimensional encoding space can reconstruct images more efficiently and with a smaller reconstruction error when the k-space sampling distribution and the number of samples are controlled. Copyright © 2012 Wiley Periodicals, Inc.

Neutron Imaging Reveals Internal Plant Hydraulic Dynamics

Energy Technology Data Exchange (ETDEWEB)

Warren, Jeffrey [ORNL; Bilheux, Hassina Z [ORNL; Kang, Misun [ORNL; Voisin, Sophie [ORNL; Cheng, Chu-Lin [ORNL; Horita, Jusuke [ORNL; Perfect, Edmund [ORNL

2013-01-01

Many terrestrial ecosystem processes are constrained by water availability and transport within the soil. Knowledge of plant water fluxes is thus critical for assessing mechanistic processes linked to biogeochemical cycles, yet resolution of root structure and xylem water transport dynamics has been a particularly daunting task for the ecologist. Through neutron imaging, we demonstrate the ability to non-invasively monitor individual root functionality and water fluxes within Zea mays L. (maize) and Panicum virgatum L. (switchgrass) seedlings growing in a sandy medium. Root structure and growth were readily imaged by neutron radiography and neutron computed tomography. Seedlings were irrigated with water or deuterium oxide and imaged through time as a growth lamp was cycled on to alter leaf demand for water. Sub-millimeter scale resolution reveals timing and magnitudes of root water uptake, redistribution within the roots, and root-shoot hydraulic linkages, relationships not well characterized by other techniques.

SEM analysis for irradiated materials

International Nuclear Information System (INIS)

Liu Xiaosong; Yao Liang

2008-06-01

A radiation-proof Scanning Electron Microscope (SEM) system is introduced. It has been widely used in various areas. For analyzing radioactive samples, normal SEM system needs lots of alterations. Based on KYKY-2800B SEM, the sample room, belt line, operating table and aerator were updated. New radiation-proof SEM system has used to analytic surface contaminated samples and RPV materials samples. An elementary means of SEM analysis for radioactive samples was studied, and this examination supported some available references for further irradiated fuel researches. (authors)

Characterization of Yeast Biofilm by Cryo-SEM and FIB-SEM

Czech Academy of Sciences Publication Activity Database

Hrubanová, Kamila; Nebesářová, Jana; Růžička, F.; Dluhoš, J.; Krzyžánek, Vladislav

2013-01-01

Roč. 19, S2 (2013), s. 226-227 ISSN 1431-9276 R&D Projects: GA MŠk EE.2.3.20.0103; GA TA ČR TE01020118; GA ČR GAP205/11/1687 Institutional support: RVO:68081731 ; RVO:60077344 Keywords : yeast biofilm * cryo-SEM * FIB-SEM Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.757, year: 2013

Cryogenic EBSD reveals structure of directionally solidified ice–polymer composite

Energy Technology Data Exchange (ETDEWEB)

Donius, Amalie E., E-mail: amalie.donius@gmail.com [Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755 (United States); Department of Materials Science and Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Obbard, Rachel W., E-mail: Rachel.W.Obbard@dartmouth.edu [Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755 (United States); Burger, Joan N., E-mail: ridge.of.the.ancients@gmail.com [Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755 (United States); Department of Materials Science and Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Hunger, Philipp M., E-mail: philipp.m.hunger@gmail.com [Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755 (United States); Department of Materials Science and Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Baker, Ian, E-mail: Ian.Baker@dartmouth.edu [Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755 (United States); Doherty, Roger D., E-mail: dohertrd@drexel.edu [Department of Materials Science and Engineering, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104 (United States); Wegst, Ulrike G.K., E-mail: ulrike.wegst@dartmouth.edu [Thayer School of Engineering, Dartmouth College, 14 Engineering Drive, Hanover, NH 03755 (United States)

2014-07-01

Despite considerable research efforts on directionally solidified or freeze-cast materials in recent years, little fundamental knowledge has been gained that links model with experiment. In this contribution, the cryogenic characterization of directionally solidified polymer solutions illustrates, how powerful cryo-scanning electron microscopy combined with electron backscatter diffraction is for the structural characterization of ice–polymer composite materials. Under controlled sublimation, the freeze-cast polymer scaffold structure is revealed and imaged with secondary electrons. Electron backscatter diffraction fabric analysis shows that the ice crystals, which template the polymer scaffold and create the lamellar structure, have a-axes oriented parallel to the direction of solidification and the c-axes perpendicular to it. These results indicate the great potential of both cryo-scanning electron microscopy and cryo-electron backscatter diffraction in gaining fundamental knowledge of structure–property–processing correlations. - Highlights: • Cryo-SEM of freeze-cast polymer solution reveals an ice-templated structure. • Cryo-EBSD reveals the ice crystal a-axis to parallel the solidification direction. • The honeycomb-like polymer phase favors columnar ridges only on one side. • Combining cryo-SEM with EBSD links solidification theory with experiment.

Cryogenic EBSD reveals structure of directionally solidified ice–polymer composite

International Nuclear Information System (INIS)

Donius, Amalie E.; Obbard, Rachel W.; Burger, Joan N.; Hunger, Philipp M.; Baker, Ian; Doherty, Roger D.; Wegst, Ulrike G.K.

2014-01-01

Despite considerable research efforts on directionally solidified or freeze-cast materials in recent years, little fundamental knowledge has been gained that links model with experiment. In this contribution, the cryogenic characterization of directionally solidified polymer solutions illustrates, how powerful cryo-scanning electron microscopy combined with electron backscatter diffraction is for the structural characterization of ice–polymer composite materials. Under controlled sublimation, the freeze-cast polymer scaffold structure is revealed and imaged with secondary electrons. Electron backscatter diffraction fabric analysis shows that the ice crystals, which template the polymer scaffold and create the lamellar structure, have a-axes oriented parallel to the direction of solidification and the c-axes perpendicular to it. These results indicate the great potential of both cryo-scanning electron microscopy and cryo-electron backscatter diffraction in gaining fundamental knowledge of structure–property–processing correlations. - Highlights: • Cryo-SEM of freeze-cast polymer solution reveals an ice-templated structure. • Cryo-EBSD reveals the ice crystal a-axis to parallel the solidification direction. • The honeycomb-like polymer phase favors columnar ridges only on one side. • Combining cryo-SEM with EBSD links solidification theory with experiment

SEM Analysis of Surface Impact on Biofilm Antibiotic Treatment.

Science.gov (United States)

Gomes, Luciana Calheiros; Mergulhão, Filipe José

2017-01-01

The aim of this work was to use scanning electron microscopy (SEM) to investigate the effect of ampicillin treatment on Escherichia coli biofilms formed on two surface materials with different properties, silicone (SIL) and glass (GLA). Epifluorescence microscopy (EM) was initially used to assess biofilm formation and killing efficiency on both surfaces. This technique showed that higher bacterial colonization was obtained in the hydrophobic SIL than in the hydrophilic GLA. It has also shown that higher biofilm inactivation was attained for GLA after the antibiotic treatment (7-log reduction versus 1-log reduction for SIL). Due to its high resolution and magnification, SEM enabled a more detailed analysis of the antibiotic effect on biofilm cells, complementing the killing efficiency information obtained by EM. SEM micrographs revealed that ampicillin-treated cells have an elongated form when compared to untreated cells. Additionally, it has shown that different materials induced different levels of elongation on cells exposed to antibiotic. Biofilms formed on GLA showed a 37% higher elongation than those formed on SIL. Importantly, cell elongation was related to viability since ampicillin had a higher bactericidal effect on GLA-formed biofilms. These findings raise the possibility of using SEM for understanding the efficacy of antimicrobial treatments by observation of biofilm morphology.

Characteristics of different frequency ranges in scanning electron microscope images

International Nuclear Information System (INIS)

Sim, K. S.; Nia, M. E.; Tan, T. L.; Tso, C. P.; Ee, C. S.

2015-01-01

We demonstrate a new approach to characterize the frequency range in general scanning electron microscope (SEM) images. First, pure frequency images are generated from low frequency to high frequency, and then, the magnification of each type of frequency image is implemented. By comparing the edge percentage of the SEM image to the self-generated frequency images, we can define the frequency ranges of the SEM images. Characterization of frequency ranges of SEM images benefits further processing and analysis of those SEM images, such as in noise filtering and contrast enhancement

Characteristics of different frequency ranges in scanning electron microscope images

Energy Technology Data Exchange (ETDEWEB)

Sim, K. S., E-mail: kssim@mmu.edu.my; Nia, M. E.; Tan, T. L.; Tso, C. P.; Ee, C. S. [Faculty of Engineering and Technology, Multimedia University, 75450 Melaka (Malaysia)

2015-07-22

We demonstrate a new approach to characterize the frequency range in general scanning electron microscope (SEM) images. First, pure frequency images are generated from low frequency to high frequency, and then, the magnification of each type of frequency image is implemented. By comparing the edge percentage of the SEM image to the self-generated frequency images, we can define the frequency ranges of the SEM images. Characterization of frequency ranges of SEM images benefits further processing and analysis of those SEM images, such as in noise filtering and contrast enhancement.

Cryo-Scanning Electron Microscopy (SEM) and Scanning Transmission Electron Microscopy (STEM)-in-SEM for Bio- and Organo-Mineral Interface Characterization in the Environment.

Science.gov (United States)

Wille, Guillaume; Hellal, Jennifer; Ollivier, Patrick; Richard, Annie; Burel, Agnes; Jolly, Louis; Crampon, Marc; Michel, Caroline

2017-12-01

Understanding biofilm interactions with surrounding substratum and pollutants/particles can benefit from the application of existing microscopy tools. Using the example of biofilm interactions with zero-valent iron nanoparticles (nZVI), this study aims to apply various approaches in biofilm preparation and labeling for fluorescent or electron microscopy and energy dispersive X-ray spectrometry (EDS) microanalysis for accurate observations. According to the targeted microscopy method, biofilms were sampled as flocs or attached biofilm, submitted to labeling using 4',6-diamidino-2-phenylindol, lectins PNA and ConA coupled to fluorescent dye or gold nanoparticles, and prepared for observation (fixation, cross-section, freezing, ultramicrotomy). Fluorescent microscopy revealed that nZVI were embedded in the biofilm structure as aggregates but the resolution was insufficient to observe individual nZVI. Cryo-scanning electron microscopy (SEM) observations showed nZVI aggregates close to bacteria, but it was not possible to confirm direct interactions between nZVI and cell membranes. Scanning transmission electron microscopy in the SEM (STEM-in-SEM) showed that nZVI aggregates could enter the biofilm to a depth of 7-11 µm. Bacteria were surrounded by a ring of extracellular polymeric substances (EPS) preventing direct nZVI/membrane interactions. STEM/EDS mapping revealed a co-localization of nZVI aggregates with lectins suggesting a potential role of EPS in nZVI embedding. Thus, the combination of divergent microscopy approaches is a good approach to better understand and characterize biofilm/metal interactions.

Contrast of Backscattered Electron SEM Images of Nanoparticles on Substrates with Complex Structure.

Science.gov (United States)

Kowoll, Thomas; Müller, Erich; Fritsch-Decker, Susanne; Hettler, Simon; Störmer, Heike; Weiss, Carsten; Gerthsen, Dagmar

2017-01-01

This study is concerned with backscattered electron scanning electron microscopy (BSE SEM) contrast of complex nanoscaled samples which consist of SiO 2 nanoparticles (NPs) deposited on indium-tin-oxide covered bulk SiO 2 and glassy carbon substrates. BSE SEM contrast of NPs is studied as function of the primary electron energy and working distance. Contrast inversions are observed which prevent intuitive interpretation of NP contrast in terms of material contrast. Experimental data is quantitatively compared with Monte-Carlo- (MC-) simulations. Quantitative agreement between experimental data and MC-simulations is obtained if the transmission characteristics of the annular semiconductor detector are taken into account. MC-simulations facilitate the understanding of NP contrast inversions and are helpful to derive conditions for optimum material and topography contrast.

Live cell CRISPR-imaging in plants reveals dynamic telomere movements

KAUST Repository

Dreissig, Steven

2017-05-16

Elucidating the spatio-temporal organization of the genome inside the nucleus is imperative to understand the regulation of genes and non-coding sequences during development and environmental changes. Emerging techniques of chromatin imaging promise to bridge the long-standing gap between sequencing studies which reveal genomic information and imaging studies that provide spatial and temporal information of defined genomic regions. Here, we demonstrate such an imaging technique based on two orthologues of the bacterial CRISPR-Cas9 system. By fusing eGFP/mRuby2 to the catalytically inactive version of Streptococcus pyogenes and Staphylococcus aureus Cas9, we show robust visualization of telomere repeats in live leaf cells of Nicotiana benthamiana. By tracking the dynamics of telomeres visualized by CRISPR-dCas9, we reveal dynamic telomere movements of up to 2 μm within 30 minutes during interphase. Furthermore, we show that CRISPR-dCas9 can be combined with fluorescence-labelled proteins to visualize DNA-protein interactions in vivo. By simultaneously using two dCas9 orthologues, we pave the way for imaging of multiple genomic loci in live plants cells. CRISPR-imaging bears the potential to significantly improve our understanding of the dynamics of chromosomes in live plant cells.

In-situ SEM microchip setup for electrochemical experiments with water based solutions

International Nuclear Information System (INIS)

Jensen, E.; Købler, C.; Jensen, P.S.; Mølhave, K.

2013-01-01

Studying electrochemical (EC) processes with electron microscopes offers the possibility of achieving much higher resolution imaging of nanoscale processes in real time than with optical microscopes. We have developed a vacuum sealed liquid sample electrochemical cell with electron transparent windows, microelectrodes and an electrochemical reference electrode. The system, called the EC-SEM Cell, is used to study electrochemical reactions in liquid with a standard scanning electron microscope (SEM). The central component is a microfabricated chip with a thin (50 nm) Si-rich silicon nitride (SiNx) window with lithographically defined platinum microelectrodes. We show here the design principles of the EC-SEM system, its detailed construction and how it has been used to perform a range of EC experiments, two of which are presented here. It is shown that the EC-SEM Cell can survive extended in-situ EC experiments. Before the EC experiments we characterized the beam current being deposited in the liquid as this will affect the experiments. The first EC experiment shows the influence of the electron-beam (e-beam) on a nickel solution by inducing electroless nickel deposition on the window when increasing the current density from the e-beam. The second experiment shows electrolysis in EC-SEM Cell, induced by the built-in electrodes. - Highlights: • New in-situ SEM system for electrochemistry. • In-situ Beam current measurements through liquid. • In-situ SEM E-beam-induced electroless deposition of Ni. • In-situ electrolysis

In-situ SEM microchip setup for electrochemical experiments with water based solutions

Energy Technology Data Exchange (ETDEWEB)

Jensen, E., E-mail: eric.jensen@nanotech.dtu.dk [DTU Nanotech, Technical University of Denmark, Ørsteds Plads, Building 345E, 2800 Kongens Lyngby (Denmark); DTU CEN, Technical University of Denmark, Fysikvej, Building 307, 2800 Kongens Lyngby (Denmark); Købler, C., E-mail: carsten.kobler@nanotech.dtu.dk [DTU Nanotech, Technical University of Denmark, Ørsteds Plads, Building 345E, 2800 Kongens Lyngby (Denmark); DTU CEN, Technical University of Denmark, Fysikvej, Building 307, 2800 Kongens Lyngby (Denmark); Jensen, P.S., E-mail: psj@kemi.dtu.dk [DTU Kemi, Technical University of Denmark, Kemitorvet, Building 207, 2800 Kongens Lyngby (Denmark); Mølhave, K., E-mail: kristian.molhave@nanotech.dtu.dk [DTU Nanotech, Technical University of Denmark, Ørsteds Plads, Building 345E, 2800 Kongens Lyngby (Denmark)

2013-06-15

Studying electrochemical (EC) processes with electron microscopes offers the possibility of achieving much higher resolution imaging of nanoscale processes in real time than with optical microscopes. We have developed a vacuum sealed liquid sample electrochemical cell with electron transparent windows, microelectrodes and an electrochemical reference electrode. The system, called the EC-SEM Cell, is used to study electrochemical reactions in liquid with a standard scanning electron microscope (SEM). The central component is a microfabricated chip with a thin (50 nm) Si-rich silicon nitride (SiNx) window with lithographically defined platinum microelectrodes. We show here the design principles of the EC-SEM system, its detailed construction and how it has been used to perform a range of EC experiments, two of which are presented here. It is shown that the EC-SEM Cell can survive extended in-situ EC experiments. Before the EC experiments we characterized the beam current being deposited in the liquid as this will affect the experiments. The first EC experiment shows the influence of the electron-beam (e-beam) on a nickel solution by inducing electroless nickel deposition on the window when increasing the current density from the e-beam. The second experiment shows electrolysis in EC-SEM Cell, induced by the built-in electrodes. - Highlights: • New in-situ SEM system for electrochemistry. • In-situ Beam current measurements through liquid. • In-situ SEM E-beam-induced electroless deposition of Ni. • In-situ electrolysis.

Ao leitor sem medo

Directory of Open Access Journals (Sweden)

José Eisenberg

2000-05-01

Full Text Available O texto resenha Ao leitor sem medo, de Renato Janine Ribeiro (Belo Horizonte, UFMG, 1999.This text is a review of Ao leitor sem medo by Renato Janine Ribeiro (Belo Horizonte, UFMG, 1999

Contrast of Backscattered Electron SEM Images of Nanoparticles on Substrates with Complex Structure

Directory of Open Access Journals (Sweden)

Thomas Kowoll

2017-01-01

Full Text Available This study is concerned with backscattered electron scanning electron microscopy (BSE SEM contrast of complex nanoscaled samples which consist of SiO2 nanoparticles (NPs deposited on indium-tin-oxide covered bulk SiO2 and glassy carbon substrates. BSE SEM contrast of NPs is studied as function of the primary electron energy and working distance. Contrast inversions are observed which prevent intuitive interpretation of NP contrast in terms of material contrast. Experimental data is quantitatively compared with Monte-Carlo- (MC- simulations. Quantitative agreement between experimental data and MC-simulations is obtained if the transmission characteristics of the annular semiconductor detector are taken into account. MC-simulations facilitate the understanding of NP contrast inversions and are helpful to derive conditions for optimum material and topography contrast.

Investigation of CPD and HMDS Sample Preparation Techniques for Cervical Cells in Developing Computer-Aided Screening System Based on FE-SEM/EDX

Science.gov (United States)

Ng, Siew Cheok; Abu Osman, Noor Azuan

2014-01-01

This paper investigated the effects of critical-point drying (CPD) and hexamethyldisilazane (HMDS) sample preparation techniques for cervical cells on field emission scanning electron microscopy and energy dispersive X-ray (FE-SEM/EDX). We investigated the visualization of cervical cell image and elemental distribution on the cervical cell for two techniques of sample preparation. Using FE-SEM/EDX, the cervical cell images are captured and the cell element compositions are extracted for both sample preparation techniques. Cervical cell image quality, elemental composition, and processing time are considered for comparison of performances. Qualitatively, FE-SEM image based on HMDS preparation technique has better image quality than CPD technique in terms of degree of spread cell on the specimen and morphologic signs of cell deteriorations (i.e., existence of plate and pellet drying artifacts and membrane blebs). Quantitatively, with mapping and line scanning EDX analysis, carbon and oxygen element compositions in HMDS technique were higher than the CPD technique in terms of weight percentages. The HMDS technique has shorter processing time than the CPD technique. The results indicate that FE-SEM imaging, elemental composition, and processing time for sample preparation with the HMDS technique were better than CPD technique for cervical cell preparation technique for developing computer-aided screening system. PMID:25610902

New Details of the Human Corneal Limbus Revealed With Second Harmonic Generation Imaging.

Science.gov (United States)

Park, Choul Yong; Lee, Jimmy K; Zhang, Cheng; Chuck, Roy S

2015-09-01

To report novel findings of the human corneal limbus by using second harmonic generation (SHG) imaging. Corneal limbus was imaged by using an inverted two-photon excitation fluorescence microscope. Laser (Ti:Sapphire) was tuned at 850 nm for two-photon excitation. Backscatter signals of SHG and autofluorescence (AF) were collected through a 425/30-nm emission filter and a 525/45-emission filter, respectively. Multiple, consecutive, and overlapping image stacks (z-stack) were acquired for the corneal limbal area. Two novel collagen structures were revealed by SHG imaging at the limbus: an anterior limbal cribriform layer and presumed anchoring fibers. Anterior limbal cribriform layer is an intertwined reticular collagen architecture just beneath the limbal epithelial niche and is located between the peripheral cornea and Tenon's/scleral tissue. Autofluorescence imaging revealed high vascularity in this structure. Central to the anterior limbal cribriform layer, radial strands of collagen were found to connect the peripheral cornea to the limbus. These presumed anchoring fibers have both collagen and elastin and were found more extensively in the superficial layers than deep layer and were absent in very deep limbus near Schlemm's canal. By using SHG imaging, new details of the collagen architecture of human corneal limbal area were elucidated. High resolution images with volumetric analysis revealed two novel collagen structures.

High resolution imaging of surface patterns of single bacterial cells

International Nuclear Information System (INIS)

Greif, Dominik; Wesner, Daniel; Regtmeier, Jan; Anselmetti, Dario

2010-01-01

We systematically studied the origin of surface patterns observed on single Sinorhizobium meliloti bacterial cells by comparing the complementary techniques atomic force microscopy (AFM) and scanning electron microscopy (SEM). Conditions ranged from living bacteria in liquid to fixed bacteria in high vacuum. Stepwise, we applied different sample modifications (fixation, drying, metal coating, etc.) and characterized the observed surface patterns. A detailed analysis revealed that the surface structure with wrinkled protrusions in SEM images were not generated de novo but most likely evolved from similar and naturally present structures on the surface of living bacteria. The influence of osmotic stress to the surface structure of living cells was evaluated and also the contribution of exopolysaccharide and lipopolysaccharide (LPS) by imaging two mutant strains of the bacterium under native conditions. AFM images of living bacteria in culture medium exhibited surface structures of the size of single proteins emphasizing the usefulness of AFM for high resolution cell imaging.

The effect of home bleaching agents on the surface roughness of five different composite resins: A SEM evaluation.

Science.gov (United States)

Cengiz, Esra; Kurtulmus-Yilmaz, Sevcan; Ulusoy, Nuran; Deniz, Sule Tugba; Yuksel-Devrim, Ece

2016-05-01

The aim of this study was to investigate the effect of hydrogen peroxide (HP) and carbamide peroxide (CP) on the surface roughness of five different composite resins using profilometer and scanning electron microscope (SEM). Thirty-six specimens (1 mm thick, 10 mm in diameter) of five composite resins were fabricated. Each composite group was equally divided into three subgroups as control, CP and HP. In control group, specimens were stored in daily refreshed distilled water during the 14-day testing period. In other groups, 10% HP (Opalescence Treswhite) and 10% CP (Opalescence PF) were applied and surface roughness values (Ra) of each specimen were measured with a profilometer at the end of 14 days. Additionally, SEM analysis was performed to evaluate the surface deformations of composite resins. Data were analyzed with Kruskal-Wallis and Mann-Whitney U tests. Ra values of composite groups exposed to bleaching agents were statistically higher than control group (p composite group while SEM micrographs showed higher surface alterations at HP group compared to CP. Among the composite resins tested, Ceram-X Mono revealed the lowest Ra values after CP and HP applications as seen at SEM images. Home bleaching agents increased the surface roughness of all composites. Except CP applied Ceram-X mono specimens, Ra values of all composite resins evaluated in this study exceeded the critical limit of 0.2 μm. Ceram-X mono was the least affected composite material after bleaching application. SCANNING 38:277-283, 2016. © 2016 Wiley Periodicals, Inc. © Wiley Periodicals, Inc.

3D SEM for surface topography quantification – a case study on dental surfaces

International Nuclear Information System (INIS)

Glon, F; Flys, O; Lööf, P-J; Rosén, B-G

2014-01-01

3D analysis of surface topography is becoming a more used tool for industry and research. New ISO standards are being launched to assist in quantifying engineering surfaces. The traditional optical measuring instrumentation used for 3D surface characterization has been optical interferometers and confocal based instrumentation. However, the resolution here is limited in the lateral dimension to the wavelength of visible light to about 500 nm. The great advantage using the SEM for topography measurements is the high flexibility to zoom from low magnifications and locating interesting areas to high magnification of down to nanometer large surface features within seconds. This paper presents surface characterization of dental implant micro topography. 3D topography data was created from SEM images using commercial photogrammetric software. A coherence scanning interferometer was used for reference measurements to compare with the 3D SEM measurements on relocated areas. As a result of this study, measurements emphasizes that the correlation between the accepted CSI measurements and the new technology represented by photogrammetry based on SEM images for many areal characterization parameters are around or less than 20%. The importance of selecting sampling and parameter sensitivity to varying sampling is high-lighted. Future work includes a broader study of limitations of the photogrammetry technique on certified micro-geometries and more application surfaces at different scales

UV laser ablation of intraocular lenses: SEM and AFM microscopy examination of the biomaterial surface

International Nuclear Information System (INIS)

Spyratou, E.; Asproudis, I.; Tsoutsi, D.; Bacharis, C.; Moutsouris, K.; Makropoulou, M.; Serafetinides, A.A.

2010-01-01

Several new materials and patterns are studied for the formation and etching of intraocular lenses (IOLs), in order to improve their optical properties, to reduce the diffractive aberrations and to decrease the incidence of posterior capsular opacification. The aim of this study is to investigate the use of UV (λ = 266 nm) laser pulses to ablate the intraocular lenses materials, and thus to provide an alternative to conventional surface shaping techniques for IOLs fabrication. Ablation experiments were conducted using various polymer substrates of hydrophobic acrylic IOLs and PMMA IOLs. We investigated the ablation efficiency and the morphology of the ablated area by imaging the surface modification with atomic force microscopy (AFM) and scanning electron microscopy (SEM). The morphological appearance of IOL samples reveals the effect of a photochemical and photothermal ablation mechanism.

UV laser ablation of intraocular lenses: SEM and AFM microscopy examination of the biomaterial surface

Energy Technology Data Exchange (ETDEWEB)

Spyratou, E., E-mail: ellas5@central.ntua.gr [National Technical University of Athens, School of Applied Mathematical and Physical Sciences, Department of Physics, Zografou Campus, Athens, 15780 (Greece); Asproudis, I. [Department of Ophthalmology, University Hospital of Ioannina, Ioannina, 45110 (Greece); Tsoutsi, D. [Department of Chemistry, University of Ioannina, Ioannina, 45110 (Greece); Bacharis, C.; Moutsouris, K.; Makropoulou, M.; Serafetinides, A.A. [National Technical University of Athens, School of Applied Mathematical and Physical Sciences, Department of Physics, Zografou Campus, Athens, 15780 (Greece)

2010-02-01

Several new materials and patterns are studied for the formation and etching of intraocular lenses (IOLs), in order to improve their optical properties, to reduce the diffractive aberrations and to decrease the incidence of posterior capsular opacification. The aim of this study is to investigate the use of UV ({lambda} = 266 nm) laser pulses to ablate the intraocular lenses materials, and thus to provide an alternative to conventional surface shaping techniques for IOLs fabrication. Ablation experiments were conducted using various polymer substrates of hydrophobic acrylic IOLs and PMMA IOLs. We investigated the ablation efficiency and the morphology of the ablated area by imaging the surface modification with atomic force microscopy (AFM) and scanning electron microscopy (SEM). The morphological appearance of IOL samples reveals the effect of a photochemical and photothermal ablation mechanism.

Development of Focused Ion Beam technique for high speed steel 3D-SEM artefact fabrication

DEFF Research Database (Denmark)

Carli, Lorenzo; MacDonald, A. Nicole; De Chiffre, Leonardo

2009-01-01

The work describes preliminary manufacture by grinding, followed by machining on a Focused Ion Beam (FIB), of a high speed steel step artefact for 3D-SEM calibration. The FIB is coupled with a SEM in the so called dual beam instrument. The milling capabilities of FIB were checked from a qualitative...... point of view, using the dual beam SEM imaging, and quantitatively using a reference stylus instrument, to establish traceability. A triangular section having a depth of about 10 μm was machined, where the 50 μm curvature radius due to grinding was reduced to about 2 μm by FIB milling...

Novel Polyurethane Matrix Systems Reveal a Particular Sustained Release Behavior Studied by Imaging and Computational Modeling.

Science.gov (United States)

Campiñez, María Dolores; Caraballo, Isidoro; Puchkov, Maxim; Kuentz, Martin

2017-07-01

The aim of the present work was to better understand the drug-release mechanism from sustained release matrices prepared with two new polyurethanes, using a novel in silico formulation tool based on 3-dimensional cellular automata. For this purpose, two polymers and theophylline as model drug were used to prepare binary matrix tablets. Each formulation was simulated in silico, and its release behavior was compared to the experimental drug release profiles. Furthermore, the polymer distributions in the tablets were imaged by scanning electron microscopy (SEM) and the changes produced by the tortuosity were quantified and verified using experimental data. The obtained results showed that the polymers exhibited a surprisingly high ability for controlling drug release at low excipient concentrations (only 10% w/w of excipient controlled the release of drug during almost 8 h). The mesoscopic in silico model helped to reveal how the novel biopolymers were controlling drug release. The mechanism was found to be a special geometrical arrangement of the excipient particles, creating an almost continuous barrier surrounding the drug in a very effective way, comparable to lipid or waxy excipients but with the advantages of a much higher compactability, stability, and absence of excipient polymorphism.

SEM studies of the structure of the gels prepared from untreated and radiation modified potato starch

International Nuclear Information System (INIS)

Cieśla, Krystyna; Sartowska, Bożena; Królak, Edward

2015-01-01

Potato starch was irradiated with a 60 Co gamma rays using doses of 5, 10, 20 and 30 kGy. Gels containing ca. 9.1% of starch were prepared by heating the starch suspensions in the heating chamber stabilized at 100 °C. Four procedures were applied for preparation of the samples in regard to SEM studies and the ability to observe the radiation effect by SEM was assessed for each method. Differences were observed between the SEM images recorded for the non-irradiated samples prepared using all the methods, and those irradiated. Images of the non-irradiated gels indicate generally a honey-comb structure, while smooth areas but with oriented fractures has appeared after irradiation. Modification of gel structure corresponds to the applied dose. The results were related to the process of gel formation (as observed by means of the hot stage microscope) to decrease in swelling power of the irradiated starch and to decreased viscosity of the resulting gels. It can be concluded that the differences in structural properties of gels shown by SEM result probably due to the better homogenization of the gels formed after radiation induced degradation. - Highlights: • Four procedures of the preservation of starch gels for SEM studies were applied. • The ability to observe the radiation effect by SEM was assessed for each method. • Dose dependent changes in the gel structure were discovered. • It was related to decrease in the swelling power and decreased viscosity of the gels. • A hot-stage microscope was applied in order to follow the gelatinization process

Search Engine Marketing (SEM): Financial & Competitive Advantages of an Effective Hotel SEM Strategy

OpenAIRE

Leora Halpern Lanz

2015-01-01

Search Engine Marketing and Optimization (SEO, SEM) are keystones of a hotels marketing strategy, in fact research shows that 90% of travelers start their vacation planning with a Google search. Learn five strategies that can enhance a hotels SEO and SEM strategies to boost bookings.

OpenCV-Based Nanomanipulation Information Extraction and the Probe Operation in SEM

Directory of Open Access Journals (Sweden)

Dongjie Li

2015-02-01

Full Text Available Aimed at the established telenanomanipulation system, the method of extracting location information and the strategies of probe operation were studied in this paper. First, the machine learning algorithm of OpenCV was used to extract location information from SEM images. Thus nanowires and probe in SEM images can be automatically tracked and the region of interest (ROI can be marked quickly. Then the location of nanowire and probe can be extracted from the ROI. To study the probe operation strategy, the Van der Waals force between probe and a nanowire was computed; thus relevant operating parameters can be obtained. With these operating parameters, the nanowire in 3D virtual environment can be preoperated and an optimal path of the probe can be obtained. The actual probe runs automatically under the telenanomanipulation system's control. Finally, experiments were carried out to verify the above methods, and results show the designed methods have achieved the expected effect.

A Miniaturized Variable Pressure Scanning Electron Microscope (MVP-SEM) for the Surface of Mars: An Instrument for the Planetary Science Community

Science.gov (United States)

Edmunson, J.; Gaskin, J. A.; Danilatos, G.; Doloboff, I. J.; Effinger, M. R.; Harvey, R. P.; Jerman, G. A.; Klein-Schoder, R.; Mackie, W.; Magera, B.;

SEM and Raman studies of CNT films on porous Si

Science.gov (United States)

Belka, R.; Keczkowska, J.; Suchańska, M.; Firek, P.; Wronka, H.; Kozłowski, M.; Radomska, J.; Czerwosz, E.; Craciunoiu, F.

2017-08-01

Carbon nanotube (CNT) films deposited on different porous silica substrates were studied by Scanning Electron Microscopy (SEM) and Raman Spectroscopy (RS). The films samples were prepared by a two-step method consisting of PVD and CVD processes. In the first step the nanocomposite Ni-C film was obtained by evaporation in dynamic vacuum from two separated sources of fullerenes and nickel acetate. Those films were deposited on porous silica and DLC/porous silica substrates. Analysis of SEM imaging showed that the obtained film are composed of carbon nanotubes, the distribution, size and quality of which depend on the type of substrate. The CNT films were studied by RS method to determine the influence of the substrate type on disordering of carbonaceous structure and quality of CNT in deposited films.

Search Engine Marketing (SEM: Financial & Competitive Advantages of an Effective Hotel SEM Strategy

Directory of Open Access Journals (Sweden)

Leora Halpern Lanz

2015-05-01

Full Text Available Search Engine Marketing and Optimization (SEO, SEM are keystones of a hotels marketing strategy, in fact research shows that 90% of travelers start their vacation planning with a Google search. Learn five strategies that can enhance a hotels SEO and SEM strategies to boost bookings.

Nanomanufacturing Concerns about Measurements Made in the SEM Part IV: Charging and its Mitigation.

Science.gov (United States)

Postek, Michael T; Vladár, András E

2015-01-01

This is the fourth part of a series of tutorial papers discussing various causes of measurement uncertainty in scanned particle beam instruments, and some of the solutions researched and developed at NIST and other research institutions. Scanned particle beam instruments especially the scanning electron microscope (SEM) have gone through tremendous evolution to become indispensable tools for many and diverse scientific and industrial applications. These improvements have significantly enhanced their performance and made them far easier to operate. But, the ease of operation has also fostered operator complacency. In addition, the user-friendliness has reduced the apparent need for extensive operator training. Unfortunately, this has led to the idea that the SEM is just another expensive "digital camera" or another peripheral device connected to a computer and that all of the problems in obtaining good quality images and data have been solved. Hence, one using these instruments may be lulled into thinking that all of the potential pitfalls have been fully eliminated and believing that, everything one sees on the micrograph is always correct. But, as described in this and the earlier papers, this may not be the case. Care must always be taken when reliable quantitative data are being sought. The first paper in this series discussed some of the issues related to signal generation in the SEM, including instrument calibration, electron beam-sample interactions and the need for physics-based modeling to understand the actual image formation mechanisms to properly interpret SEM images. The second paper has discussed another major issue confronting the microscopist: specimen contamination and methods to eliminate it. The third paper discussed mechanical vibration and stage drift and some useful solutions to mitigate the problems caused by them, and here, in this the fourth contribution, the issues related to specimen "charging" and its mitigation are discussed relative to

Analysis list: sem-4 [Chip-atlas[Archive

Lifescience Database Archive (English)

Full Text Available sem-4 Larvae + ce10 http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/target/sem-4.1....tsv http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/target/sem-4.5.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/target/sem...-4.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/colo/sem-4.Larvae.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/ce10/colo/Larvae.gml ...

stainless steel by SEM-XRD and image analysis

Directory of Open Access Journals (Sweden)

Robinson Constanzo-R.

2014-01-01

Full Text Available El objetivo de este trabajo fue realizar un análisis cualitativ o de la distribución de un electrodepósito de cobre en el inter ior de electrodos porosos (EP de acero inoxidable y carbono grafito. Para ello, se reali zaron pruebas de electrodepositación de cobre a nivel de labora torio, con un posterior análisis de cortes de muestras de acero y grafito vía Microscopía Estereoscópica, Microscopía SEM-DRX y Análisis de Imagen, los cuales mostraron que el cobre no se deposita en forma uniforme al interior del electrodo. En el electrodo de acero, la penetra ción del depósito en el espesor fue alrededor de 50%, mientras que para el grafito a lrededor de 90%. En forma general, se observó un aumento de la cantidad de depósito hacia el extremo frente al ánodo y con sitios de difer ente crecimiento en depósito de cobre. Esto demuestra una distr ibución de corriente y potencial, función de parámetros físicos de electrodo y de la s características fisicoquímicas e hidrodinámicos del electroli to.

The ITZ in concrete with natural and recycled aggregates : Study of microstructures based on image and SEM analysis

NARCIS (Netherlands)

Bonifazi, G.; Capobianco, G.; Serranti, S.; Eggimann, M.; Wagner, E.; Di Maio, F.; Lotfi, S.

2015-01-01

Aim of this work was to investigate the microstructure of the Interfacial Transition Zone (ITZ) between cement paste and aggregate in concrete utilizing Scanning Electron Microscope (SEM) in order to identify possible effects on the ITZ related to different recipes and production parameters. SEM is

Improvement in the Characterization of the 2099 Al-Li Alloy by FE-SEM

Science.gov (United States)

Brodusch, Nicolas; Trudeau, Michel L.; Michaud, Pierre; Brochu, Mathieu; Rodrigue, Lisa; Boselli, Julien; Gauvin, Raynald

This paper describes how state-of-the-art Field-Emission Scanning Electron Microscopy (FE-SEM) can contribute to the characterization of the 2099 aluminum-lithium alloy, and metallic alloys in general. Investigations were carried out on bulk and thinned samples. BSE imaging at 3kV and STEM imaging at 30kV along with highly efficient microanalysis permitted to correlate experimental and expected structures. Although our results confirm previous studies, this work points out possible substitutions of Mg and Zn with Li, Al and Cu in the T1 precipitates. Zinc and magnesium are also present in "rice grain" shaped precipitates at the grain boundaries. The versatility of the FE-SEM is highlighted in that it can provide information at the macro and micro scales with relevant details. Its ability to probe the distribution of precipitates from nano-to micro-sizes throughout the matrix makes Field-Emission Scanning Electron Microscopy a suitable technique for the characterization of metallic alloys.

Nanomanufacturing concerns about measurements made in the SEM Part III: vibration and drift

Science.gov (United States)

Postek, Michael T.; Vladár, András. E.; Cizmar, Petr

2014-08-01

Many advanced manufacturing processes employ scanning electron microscopes (SEM) for on-line critical measurements for process and quality control. This is the third of a series of papers discussing various causes of measurement uncertainty in scanned particle beam instruments, and some of the solutions researched and developed at NIST. Scanned particle beam instruments especially the scanning electron microscope have gone through tremendous evolution to become indispensable tools for many and diverse scientifi c and industrial applications. These improvements have signifi cantly enhanced their performance and made them far easier to operate. But, ease of operation has also fostered operator complacency. In addition, the user-friendliness has reduced the need for extensive operator training. Unfortunately, this has led to the concept that the SEM is just another expensive digital camera or another peripheral device connected to a computer and that all of the issues related to obtaining quality data have been solved. Hence, a person (or company) using these instruments may be lulled into thinking that all of the potential pitfalls have been fully eliminated and they believe everything they see on the micrograph is always correct. But, as described in this and the earlier presentations this may not be the case. The fi rst paper in this series discussed some of the issues related to signal generation in the SEM, including instrument calibration, electron beam-sample interactions and the need for physics-based modelling to understand the actual image formation mechanisms to properly interpret SEM images. The second paper, discussed another major issue confronting the microscopist: specimen contamination and methods of contamination elimination. This third paper, discusses vibration and drift and some useful solutions.

New airtight transfer box for SEM experiments: Application to lithium and sodium metals observation and analyses.

Science.gov (United States)

Stephant, Nicolas; Grissa, Rabeb; Guillou, Fanch; Bretaudeau, Mickaël; Borjon-Piron, Yann; Guillet, Jacques; Moreau, Philippe

2018-04-18

The surface of some materials reacts very quickly on contact with air, either because it is oxidized or because it gets humidity from the air. For the sake of original surface observation by scanning electron microscopy (SEM), we conceived an airtight transfer box to keep the samples under vacuum from the place of manufacturing to the SEM chamber. This object is designed to fit in all the models of SEM including those provided with an airlock chamber. The design is voluntarily simplified to allow the manufacturing of the object by a standard mechanical workshop. The transfer box can be easily opened by gravity inside the SEM and allows the preservation of the best vacuum inside, before opening. SEM images and energy dispersive spectroscopy (EDX) analyses of metallic lithium and sodium samples are presented prior and after exposure to the air. X-ray Photoelectron Spectroscopy (XPS) analyses of all samples are also discussed in order to investigate the chemical environments of the detected elements. Copyright © 2018 Elsevier Ltd. All rights reserved.

Assessment of engineered surfaces roughness by high-resolution 3D SEM photogrammetry

Energy Technology Data Exchange (ETDEWEB)

Gontard, L.C., E-mail: lionelcg@gmail.com [Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Universidad de Cádiz, Puerto Real 11510 (Spain); López-Castro, J.D.; González-Rovira, L. [Departamento de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica, Escuela Superior de Ingeniería, Laboratorio de Corrosión, Universidad de Cádiz, Puerto Real 11519 (Spain); Vázquez-Martínez, J.M. [Departamento de Ingeniería Mecánica y Diseño Industrial, Escuela Superior de Ingeniería, Universidad de Cádiz, Puerto Real 11519 (Spain); Varela-Feria, F.M. [Servicio de Microscopía Centro de Investigación, Tecnología e Innovación (CITIUS), Universidad de Sevilla, Av. Reina Mercedes 4b, 41012 Sevilla (Spain); Marcos, M. [Departamento de Ingeniería Mecánica y Diseño Industrial, Escuela Superior de Ingeniería, Universidad de Cádiz, Puerto Real 11519 (Spain); and others

2017-06-15

Highlights: • We describe a method to acquire a high-angle tilt series of SEM images that is symmetrical respect to the zero tilt of the sample stage. The method can be applied in any SEM microscope. • Using the method, high-resolution 3D SEM photogrammetry can be applied on planar surfaces. • 3D models of three surfaces patterned with grooves are reconstructed with high resolution using multi-view freeware photogrammetry software as described in LC Gontard et al. Ultramicroscopy, 2016. • From the 3D models roughness parameters are measured • 3D SEM high-resolution photogrammetry is compared with two conventional methods used for roughness characetrization: stereophotogrammetry and contact profilometry. • It provides three-dimensional information with high-resolution that is out of reach for any other metrological technique. - Abstract: We describe a methodology to obtain three-dimensional models of engineered surfaces using scanning electron microscopy and multi-view photogrammetry (3DSEM). For the reconstruction of the 3D models of the surfaces we used freeware available in the cloud. The method was applied to study the surface roughness of metallic samples patterned with parallel grooves by means of laser. The results are compared with measurements obtained using stylus profilometry (PR) and SEM stereo-photogrammetry (SP). The application of 3DSEM is more time demanding than PR or SP, but it provides a more accurate representation of the surfaces. The results obtained with the three techniques are compared by investigating the influence of sampling step on roughness parameters.

SEM analysis of ionizing radiation effects in linear integrated circuits. [Scanning Electron Microscope

Science.gov (United States)

Stanley, A. G.; Gauthier, M. K.

1977-01-01

A successful diagnostic technique was developed using a scanning electron microscope (SEM) as a precision tool to determine ionization effects in integrated circuits. Previous SEM methods radiated the entire semiconductor chip or major areas. The large area exposure methods do not reveal the exact components which are sensitive to radiation. To locate these sensitive components a new method was developed, which consisted in successively irradiating selected components on the device chip with equal doses of electrons /10 to the 6th rad (Si)/, while the whole device was subjected to representative bias conditions. A suitable device parameter was measured in situ after each successive irradiation with the beam off.

Sexual Arousal and Sexually Explicit Media (SEM)

DEFF Research Database (Denmark)

Hald, Gert Martin; Stulhofer, Aleksandar; Lange, Theis

2018-01-01

-mainstream and mainstream SEM groups, and (iii) to explore the validity and predictive accuracy of the Non-Mainstream Pornography Arousal Scale (NPAS). METHODS: Online cross-sectional survey of 2,035 regular SEM users in Croatia. MAIN OUTCOMES MEASURES: Patterns of sexual arousal to 27 different SEM themes, sexual...

Multiscale characterization of pore spaces using multifractals analysis of scanning electronic microscopy images of carbonates

Directory of Open Access Journals (Sweden)

M. S. Jouini

2011-12-01

Full Text Available Pore spaces heterogeneity in carbonates rocks has long been identified as an important factor impacting reservoir productivity. In this paper, we study the heterogeneity of carbonate rocks pore spaces based on the image analysis of scanning electron microscopy (SEM data acquired at various magnifications. Sixty images of twelve carbonate samples from a reservoir in the Middle East were analyzed. First, pore spaces were extracted from SEM images using a segmentation technique based on watershed algorithm. Pores geometries revealed a multifractal behavior at various magnifications from 800x to 12 000x. In addition, the singularity spectrum provided quantitative values that describe the degree of heterogeneity in the carbonates samples. Moreover, for the majority of the analyzed samples, we found low variations (around 5% in the multifractal dimensions for magnifications between 1700x and 12 000x. Finally, these results demonstrate that multifractal analysis could be an appropriate tool for characterizing quantitatively the heterogeneity of carbonate pore spaces geometries. However, our findings show that magnification has an impact on multifractal dimensions, revealing the limit of applicability of multifractal descriptions for these natural structures.

SEM examination and analysis of the interface character in surface modified aramid-epoxy composite

International Nuclear Information System (INIS)

Hussain, S.; Khan, M.B.; Hussain, R.

2011-01-01

The surface of Kevlar fibers is chemically modified by treatment with Phthalic anhydride (PA) and the effect is examined by SEM for the laser cut, three point bending and interlaminar shear delaminated surfaces. The surface modification improved the adhesion to epoxy resin that clearly leads to cohesive fracture as opposed to interfacial failure in the untreated specimen. SEM reveals marginal surface roughening of fibers without compromising their strength. The interface modification technique described in this paper is attractive thermodynamically as it does not compromise surface free energy of the polymer matrix or that of the fiber itself to enhance wet ability. (author)

Hyperspectral imaging technology for revealing the original handwritings covered by the same inks

Directory of Open Access Journals (Sweden)

Yuanyuan Lian

2017-01-01

Full Text Available This manuscript presents a preliminary investigation on the applicability of hyperspectral imaging technology for nondestructive and rapid analysis to reveal covered original handwritings. The hyperspectral imager Nuance-Macro was used to collect the reflected light signature of inks from the overlapping parts. The software Nuance1p46 was used to analyze the reflected light signature of inks which shows the covered original handwritings. Different types of black/blue ballpoint pen inks and black/blue gel pen inks were chosen for sample preparation. From the hyperspectral images examined, the covered original handwritings of application were revealed in 90.5%, 69.1%, 49.5%, and 78.6% of the cases. Further, the correlation between the revealing effect and spectral characteristics of the reflected light of inks at the overlapping parts was interpreted through theoretical analysis and experimental verification. The results indicated that when the spectral characteristics of the reflected light of inks at the overlapping parts were the same or very similar to that of the ink that was used to cover the original handwriting, the original handwriting could not be shown. On the contrary, when the spectral characteristics of the reflected light of inks at the overlapping parts were different to that of the ink that was used to cover the original handwriting, the original handwriting was revealed.

In-situ SEM electrochemistry and radiolysis

DEFF Research Database (Denmark)

Møller-Nilsen, Rolf Erling Robberstad; Norby, Poul

are backscattered and an image is reconstructed by the microscope. But the high energy electrons are a form of ionising radiation which can significantly affect the chemistry in liquid experiments. Ionising radiation can split water, produce radicals, reduce dissolved metal ions to metal particles, and more...... experiments. During the course of these studies it has also been possible to improve on the EC-SEM system. This has resulted in pyrolysed carbon electrodes, which offer the benefit of stability at 0.75 V higher potentials than traditional gold thin-film electrodes. With the quantitative insight...... microelectrodes on the windows to enable studies of electrohcemical processes. In this way it is possible to perform in-situ electrochemical experiments such as electroplating and charge and discharge analysis of battery electrodes. In a typical liquid cell, electrons are accelerated to sufficiently high energies...

Why semicarbazide (SEM) is not an appropriate marker for the usage of nitrofurazone on agricultural animals.

Science.gov (United States)

Stadler, Richard H; Verzegnassi, Ludovica; Seefelder, Walburga; Racault, Lucie

2015-01-01

A comprehensive global database on semicarbazide (SEM) in foodstuffs and food ingredients is presented, with over 4000 data collected in foods such as seafood (crustaceans, fish powders), meat (beef, chicken powders), dairy products (e.g. raw milk, milk powders, whey, sweet buttermilk powder, caseinate, yoghurt, cheese), honey and other ingredients. The results provide evidence that the presence of SEM in certain dairy ingredients (whey, milk protein concentrates) is a by-product of chemical reactions taking place during the manufacturing process. Of the dairy ingredients tested (c. 2000 samples), 5.3% showed traces of SEM > 0.5 µg/kg. The highest incidence of SEM-positive samples in the dairy category were whey (powders, liquid) and milk protein concentrates (35% positive), with up to 13 µg/kg measured in a whey powder. Sweet buttermilk powder and caseinate followed, with 27% and 9.3% positives, respectively. SEM was not detected in raw milk, or in yoghurt or cheese. Of the crustacean products (shrimp and prawn powders) tested, 44% were positive for SEM, the highest value measured at 284 µg/kg. Fish powders revealed an unexpectedly high incidence of positive samples (25%); in this case, fraudulent addition of shellfish shells or carry-over during processing cannot be excluded. Overall, the data provide new insights into the occurrence of SEM (for dairy products and fish powders), substantially strengthening the arguments that SEM in certain food categories is not a conclusive marker of the use of the illegal antibiotic nitrofurazone.

Cryogenic-SEM investigation of CO{sub 2} hydrate morphologies

Energy Technology Data Exchange (ETDEWEB)

Camps, A.P.; Milodowski, A.; Rochelle, C.; Williams, J.F.; Jackson, P. D. [British Geological Survey, Keyworth, Nottinghamshire (United Kingdom); Camps, A.P; Lovell, M.; Williams, J.F. [Leicester Univ., Leicester (United Kingdom). Dept. of Geology

2008-07-01

Gas hydrates occur naturally around the world in the shallow-marine geosphere, and are seen as a drilling hazard in the petroleum industry due to their role in the carbon cycle, and their possible contribution in past and present climate change. Hydrates are ice-like structures composed of cages of water molecules containing one or more guest molecules, such as methane and carbon dioxide (CO{sub 2}). CO{sub 2} hydrates also occur naturally on earth and are being investigated for their potential to store large volumes of CO{sub 2} to reduce atmospheric emissions of greenhouse gases as a climate change mitigation strategy. However, the mineralogy and formation processes of hydrates are relatively poorly understood. Different imaging techniques have been utilized to study gas hydrates, such as nuclear magnetic resonance, magnetic resonance imaging, and x-ray computed tomography. Scanning Electron Microscopy (SEM) at cryogenic temperatures is another technique to study hydrates, and has been used successfully for investigation of methane and CO{sub 2} hydrates. This paper presented a study that investigated CO{sub 2} hydrates formed in laboratories, using a cryogenic-SEM. The paper presented the study methods and observations, including euhedral crystalline carbon dioxide hydrate; acicular carbon dioxide hydrate; granoblastic carbon dioxide hydrate; and gas rich carbon dioxide hydrate. It was concluded that the investigation produced various different hydrate morphologies resulting from different formation conditions. Morphologies ranged from well-defined euhedral crystals to acicular needles, and more complex, intricate forms. 22 refs., 6 figs., 1 appendix.

A simplified method for scanning electron microscopy (SEM) autoradiography

International Nuclear Information System (INIS)

Shahar, A.; Lasher, R.

1980-01-01

The combination of autoradiography with SEM provides a valuable tool for the study of labeled biological materials, but the previously described methods are complicated because they call first for the removal of gelatin from the film emulsion and this is then followed by deposition of gold vapor on the specimen. The authors describe a much simpler method which can easily be adapted to routine examination of cell cultures. In this method, gelatin is not removed; the film is coated with vaporized carbon only. This procedure permits visualization of both cellular image and distribution of silver grains. (Auth.)

Quantification of silver nanoparticle uptake and distribution within individual human macrophages by FIB/SEM slice and view.

Science.gov (United States)

Guehrs, Erik; Schneider, Michael; Günther, Christian M; Hessing, Piet; Heitz, Karen; Wittke, Doreen; López-Serrano Oliver, Ana; Jakubowski, Norbert; Plendl, Johanna; Eisebitt, Stefan; Haase, Andrea

2017-03-21

Quantification of nanoparticle (NP) uptake in cells or tissues is very important for safety assessment. Often, electron microscopy based approaches are used for this purpose, which allow imaging at very high resolution. However, precise quantification of NP numbers in cells and tissues remains challenging. The aim of this study was to present a novel approach, that combines precise quantification of NPs in individual cells together with high resolution imaging of their intracellular distribution based on focused ion beam/ scanning electron microscopy (FIB/SEM) slice and view approaches. We quantified cellular uptake of 75 nm diameter citrate stabilized silver NPs (Ag 75 Cit) into an individual human macrophage derived from monocytic THP-1 cells using a FIB/SEM slice and view approach. Cells were treated with 10 μg/ml for 24 h. We investigated a single cell and found in total 3138 ± 722 silver NPs inside this cell. Most of the silver NPs were located in large agglomerates, only a few were found in clusters of fewer than five NPs. Furthermore, we cross-checked our results by using inductively coupled plasma mass spectrometry and could confirm the FIB/SEM results. Our approach based on FIB/SEM slice and view is currently the only one that allows the quantification of the absolute dose of silver NPs in individual cells and at the same time to assess their intracellular distribution at high resolution. We therefore propose to use FIB/SEM slice and view to systematically analyse the cellular uptake of various NPs as a function of size, concentration and incubation time.

New domain for image analysis: VLSI circuits testing, with Romuald, specialized in parallel image processing

Energy Technology Data Exchange (ETDEWEB)

Rubat Du Merac, C; Jutier, P; Laurent, J; Courtois, B

1983-07-01

This paper describes some aspects of specifying, designing and evaluating a specialized machine, Romuald, for the capture, coding, and processing of video and scanning electron microscope (SEM) pictures. First the authors present the functional organization of the process unit of romuald and its hardware, giving details of its behaviour. Then they study the capture and display unit which, thanks to its flexibility, enables SEM images coding. Finally, they describe an application which is now being developed in their laboratory: testing VLSI circuits with new methods: sem+voltage contrast and image processing. 15 references.

Multispectral imaging reveals biblical-period inscription unnoticed for half a century.

Directory of Open Access Journals (Sweden)

Shira Faigenbaum-Golovin

Full Text Available Most surviving biblical period Hebrew inscriptions are ostraca-ink-on-clay texts. They are poorly preserved and once unearthed, fade rapidly. Therefore, proper and timely documentation of ostraca is essential. Here we show a striking example of a hitherto invisible text on the back side of an ostracon revealed via multispectral imaging. This ostracon, found at the desert fortress of Arad and dated to ca. 600 BCE (the eve of Judah's destruction by Nebuchadnezzar, has been on display for half a century. Its front side has been thoroughly studied, while its back side was considered blank. Our research revealed three lines of text on the supposedly blank side and four "new" lines on the front side. Our results demonstrate the need for multispectral image acquisition for both sides of all ancient ink ostraca. Moreover, in certain cases we recommend employing multispectral techniques for screening newly unearthed ceramic potsherds prior to disposal.

Does Your SEM Really Tell the Truth?-How Would You Know? Part 4: Charging and its Mitigation.

Science.gov (United States)

Postek, Michael T; Vladár, András E

2015-01-01

This is the fourth part of a series of tutorial papers discussing various causes of measurement uncertainty in scanned particle beam instruments, and some of the solutions researched and developed at NIST and other research institutions. Scanned particle beam instruments, especially the scanning electron microscope (SEM), have gone through tremendous evolution to become indispensable tools for many and diverse scientifc and industrial applications. These improvements have significantly enhanced their performance and made them far easier to operate. But, the ease of operation has also fostered operator complacency. In addition, the user-friendliness has reduced the apparent need for extensive operator training. Unfortunately, this has led to the idea that the SEM is just another expensive "digital camera" or another peripheral device connected to a computer and that all of the problems in obtaining good quality images and data have been solved. Hence, one using these instruments may be lulled into thinking that all of the potential pitfalls have been fully eliminated and believing that, everything one sees on the micrograph is always correct. But, as described in this and the earlier papers, this may not be the case. Care must always be taken when reliable quantitative data are being sought. The first paper in this series discussed some of the issues related to signal generation in the SEM, including instrument calibration, electron beam-sample interactions and the need for physics-based modeling to understand the actual image formation mechanisms to properly interpret SEM images. The second paper has discussed another major issue confronting the microscopist: specimen contamination and methods to eliminate it. The third paper discussed mechanical vibration and stage drift and some useful solutions to mitigate the problems caused by them, and here, in this the fourth contribution, the issues related to specimen "charging" and its mitigation are discussed relative to

Oxford CyberSEM: remote microscopy

International Nuclear Information System (INIS)

Rahman, M; Kirkland, A; Cockayne, D; Meyer, R

2008-01-01

The Internet has enabled researchers to communicate over vast geographical distances, sharing ideas and documents. e-Science, underpinned by Grid and Web Services, has enabled electronic communications to the next level where, in addition to document sharing, researchers can increasingly control high precision scientific instruments over the network. The Oxford CyberSEM project developed a simple Java applet via which samples placed in a JEOL 5510LV Scanning Electron Microscope (SEM) can be manipulated and examined collaboratively over the Internet. Designed with schoolchildren in mind, CyberSEM does not require any additional hardware or software other than a generic Java-enabled web browser. This paper reflects on both the technical and social challenges in designing real-time systems for controlling scientific equipments in collaborative environments. Furthermore, it proposes potential deployment beyond the classroom setting.

High-speed image analysis reveals chaotic vibratory behaviors of pathological vocal folds

Energy Technology Data Exchange (ETDEWEB)

Zhang Yu, E-mail: yuzhang@xmu.edu.c [Key Laboratory of Underwater Acoustic Communication and Marine Information Technology of the Ministry of Education, Xiamen University, Xiamen Fujian 361005 (China); Shao Jun [Shanghai EENT Hospital of Fudan University, Shanghai (China); Krausert, Christopher R. [Department of Surgery, Division of Otolaryngology - Head and Neck Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI 53792-7375 (United States); Zhang Sai [Key Laboratory of Underwater Acoustic Communication and Marine Information Technology of the Ministry of Education, Xiamen University, Xiamen Fujian 361005 (China); Jiang, Jack J. [Shanghai EENT Hospital of Fudan University, Shanghai (China); Department of Surgery, Division of Otolaryngology - Head and Neck Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI 53792-7375 (United States)

2011-01-15

Research highlights: Low-dimensional human glottal area data. Evidence of chaos in human laryngeal activity from high-speed digital imaging. Traditional perturbation analysis should be cautiously applied to aperiodic high speed image signals. Nonlinear dynamic analysis may be helpful for understanding disordered behaviors in pathological laryngeal systems. - Abstract: Laryngeal pathology is usually associated with irregular dynamics of laryngeal activity. High-speed imaging facilitates direct observation and measurement of vocal fold vibrations. However, chaotic dynamic characteristics of aperiodic high-speed image data have not yet been investigated in previous studies. In this paper, we will apply nonlinear dynamic analysis and traditional perturbation methods to quantify high-speed image data from normal subjects and patients with various laryngeal pathologies including vocal fold nodules, polyps, bleeding, and polypoid degeneration. The results reveal the low-dimensional dynamic characteristics of human glottal area data. In comparison to periodic glottal area series from a normal subject, aperiodic glottal area series from pathological subjects show complex reconstructed phase space, fractal dimension, and positive Lyapunov exponents. The estimated positive Lyapunov exponents provide the direct evidence of chaos in pathological human vocal folds from high-speed digital imaging. Furthermore, significant differences between the normal and pathological groups are investigated for nonlinear dynamic and perturbation analyses. Jitter in the pathological group is significantly higher than in the normal group, but shimmer does not show such a difference. This finding suggests that the traditional perturbation analysis should be cautiously applied to high speed image signals. However, the correlation dimension and the maximal Lyapunov exponent reveal a statistically significant difference between normal and pathological groups. Nonlinear dynamic analysis is capable of

High-speed image analysis reveals chaotic vibratory behaviors of pathological vocal folds

International Nuclear Information System (INIS)

Zhang Yu; Shao Jun; Krausert, Christopher R.; Zhang Sai; Jiang, Jack J.

2011-01-01

Research highlights: → Low-dimensional human glottal area data. → Evidence of chaos in human laryngeal activity from high-speed digital imaging. → Traditional perturbation analysis should be cautiously applied to aperiodic high speed image signals. → Nonlinear dynamic analysis may be helpful for understanding disordered behaviors in pathological laryngeal systems. - Abstract: Laryngeal pathology is usually associated with irregular dynamics of laryngeal activity. High-speed imaging facilitates direct observation and measurement of vocal fold vibrations. However, chaotic dynamic characteristics of aperiodic high-speed image data have not yet been investigated in previous studies. In this paper, we will apply nonlinear dynamic analysis and traditional perturbation methods to quantify high-speed image data from normal subjects and patients with various laryngeal pathologies including vocal fold nodules, polyps, bleeding, and polypoid degeneration. The results reveal the low-dimensional dynamic characteristics of human glottal area data. In comparison to periodic glottal area series from a normal subject, aperiodic glottal area series from pathological subjects show complex reconstructed phase space, fractal dimension, and positive Lyapunov exponents. The estimated positive Lyapunov exponents provide the direct evidence of chaos in pathological human vocal folds from high-speed digital imaging. Furthermore, significant differences between the normal and pathological groups are investigated for nonlinear dynamic and perturbation analyses. Jitter in the pathological group is significantly higher than in the normal group, but shimmer does not show such a difference. This finding suggests that the traditional perturbation analysis should be cautiously applied to high speed image signals. However, the correlation dimension and the maximal Lyapunov exponent reveal a statistically significant difference between normal and pathological groups. Nonlinear dynamic

Does your SEM really tell the truth? How would you know? part 3: vibration and drift

Science.gov (United States)

Postek, Michael T.; Vladár, András. E.; Cizmar, Petr

2014-09-01

This is the third of a series of papers discussing various causes of measurement uncertainty in scanned particle beam instruments, and some of the solutions researched and developed at NIST. Scanned particle beam instruments especially the scanning electron microscope (SEM) have gone through tremendous evolution to become indispensable tools for many and diverse scientifi c and industrial applications. These improvements have signifi cantly enhanced their performance and made them far easier to operate. But, ease of operation has also fostered operator complacency. In addition, the user-friendliness has reduced the need for extensive operator training. Unfortunately, this has led to the concept that the SEM is just another expensive digital camera or another peripheral device connected to a computer and that all of the issues related to obtaining quality data have been solved. Hence, a person (or company) using these instruments may be lulled into thinking that all of the potential pitfalls have been fully eliminated and they believe everything they see on the micrograph is always correct. But, as described in this and the earlier presentations this may not be the case. The fi rst paper in this series discussed some of the issues related to signal generation in the SEM, including instrument calibration, electron beam-sample interactions and the need for physics-based modelling to understand the actual image formation mechanisms to properly interpret SEM images. The second paper, discussed another major issue confronting the microscopist: specimen contamination and methods of contamination elimination. This third paper, discusses vibration and drift and some useful solutions.

STEM mode in the SEM for the analysis of cellular sections prepared by ultramicrotome sectioning

International Nuclear Information System (INIS)

Hondow, N; Harrington, J; Brydson, R; Brown, A

2012-01-01

The use of the dual imaging capabilities of a scanning electron microscope fitted with a transmitted electron detector is highlighted in the analysis of samples with importance in the field of nanotoxicology. Cellular uptake of nanomaterials is often examined by transmission electron microscopy of thin sections prepared by ultramicrotome sectioning. Examination by SEM allows for the detection of artefacts caused by sample preparation (eg. nanomaterial pull-out) and the complementary STEM mode permits study of the interaction between nanomaterials and cells. Thin sections of two nanomaterials of importance in nanotoxicology (cadmium selenide quantum dots and single walled carbon nanotubes) are examined using STEM mode in the SEM.

Does your SEM really tell the truth?--How would you know? Part 1.

Science.gov (United States)

Postek, Michael T; Vladár, András E

2013-01-01

The scanning electron microscope (SEM) has gone through a tremendous evolution to become a critical tool for many and diverse scientific and industrial applications. The high resolution of the SEM is especially suited for both qualitative and quantitative applications especially for nanotechnology and nanomanufacturing. Quantitatively, measurement, or metrology is one of the main uses. It is likely that one of the first questions asked before even the first scanning electron micrograph was ever recorded was: "… how big is that?" The quality of that answer has improved a great deal over the past few years especially since today these instruments are being used as a primary measurement tool on semiconductor processing lines to monitor the manufacturing processes. The well-articulated needs of semiconductor production prompted a rapid evolution of the instrument and its capabilities. Over the past 20 years or so, instrument manufacturers, through substantial semiconductor industry investment of research and development (R&D) money, have vastly improved the performance of these instruments. All users have benefited from this investment, especially where quantitative measurements with an SEM are concerned. But, how good are these data? This article discusses some of the most important aspects and larger issues associated with imaging and measurements with the SEM that every user should know, and understand before any critical quantitative work is attempted. © Wiley Periodicals, Inc.

Human bloodstains on bone artefacts: an SEM intra- and inter-sample comparative study using ratite bird tibiotarsus.

Science.gov (United States)

Hortolà, Policarp

2016-11-01

Apart from their forensic significance in crime investigation, human bloodstains have an anthropological interest due to their occurrence on certain traditional weapons and ritual objects. Previously, a guiding study of erythrocytes in experimental samples including domestic sheep (Ovis aries) tibia was carried out using a scanning electron microscope (SEM). Here, a comparative SEM study to reveal the potential differences in bloodstain surface morphology as a function of intra-sample (smear region) and inter-sample (individual smear, smearing mechanism, bone origin) parameters is reported. A fragment of emu (Dromaius novaehollandiae) tibiotarsus was smeared with an adult man's peripheral blood. After air-drying and storing indoors, the boundary and neighbouring inner areas of the three individual bloodstains obtained were examined via secondary electrons in a variable-pressure SEM working in low-vacuum mode. As a whole, desiccation microcracks were present, the limits between the smear and the substrate appeared poorly defined, and no erythrocyte negative replicas were observed in the examined areas. In addition, a putative fibrin network, more or less embedded in the dried plasma matrix, was observed in the smears' boundary. Regarding the smear region in sliding smears, the periphery and boundary revealed to be different, while the head and tail were similar. Considering individual sliding smears, they had similar characteristics. Relating to the smear region as a function of the smearing mechanism, the periphery was different whether sliding or touching, while the boundary was similar in sliding and touching smears. Concerning the smear region as a function of the bone origin, the periphery revealed to be similar in both ratite and mammalian bone, while the boundary did different in ratite and mammalian bone. The results of this study show that SEM examination can be used fruitfully to detect bloodstains on ratite bone. Combined with previous SEM results in

In Depth Analyses of LEDs by a Combination of X-ray Computed Tomography (CT) and Light Microscopy (LM) Correlated with Scanning Electron Microscopy (SEM).

Science.gov (United States)

Meyer, Jörg; Thomas, Christian; Tappe, Frank; Ogbazghi, Tekie

2016-06-16

In failure analysis, device characterization and reverse engineering of light emitting diodes (LEDs), and similar electronic components of micro-characterization, plays an important role. Commonly, different techniques like X-ray computed tomography (CT), light microscopy (LM) and scanning electron microscopy (SEM) are used separately. Similarly, the results have to be treated for each technique independently. Here a comprehensive study is shown which demonstrates the potentials leveraged by linking CT, LM and SEM. In depth characterization is performed on a white emitting LED, which can be operated throughout all characterization steps. Major advantages are: planned preparation of defined cross sections, correlation of optical properties to structural and compositional information, as well as reliable identification of different functional regions. This results from the breadth of information available from identical regions of interest (ROIs): polarization contrast, bright and dark-field LM images, as well as optical images of the LED cross section in operation. This is supplemented by SEM imaging techniques and micro-analysis using energy dispersive X-ray spectroscopy.

Exploring the interior of cuticles and compressions of fossil plants by FIB-SEM milling and image microscopy.

Science.gov (United States)

Sender, L M; Escapa, I; Benedetti, A; Cúneo, R; Diez, J B

2018-01-01

We present the first study of cuticles and compressions of fossil leaves by Focused Ion Beam Scanning Electron Microscopy (FIB-SEM). Cavities preserved inside fossil leaf compressions corresponding to substomatal chambers have been observed for the first time and several new features were identified in the cross-section cuts. These results open a new way in the investigation of the three-dimensional structures of both micro- and nanostructural features of fossil plants. Moreover, the application of the FIB-SEM technique to both fossils and extant plant remains represent a new source of taxonomical, palaeoenvironmental and palaeoclimatic information. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

MALDI-TOF mass spectrometry imaging reveals molecular level changes in ultrahigh molecular weight polyethylene joint implants in correlation with lipid adsorption.

Science.gov (United States)

Fröhlich, Sophie M; Archodoulaki, Vasiliki-Maria; Allmaier, Günter; Marchetti-Deschmann, Martina

2014-10-07

Ultrahigh molecular weight polyethylene (PE-UHMW), a material with high biocompatibility and excellent mechanical properties, is among the most commonly used materials for acetabular cup replacement in artificial joint systems. It is assumed that the interaction with synovial fluid in the biocompartment leads to significant changes relevant to material failure. In addition to hyaluronic acid, lipids are particularly relevant for lubrication in an articulating process. This study investigates synovial lipid adsorption on two different PE-UHMW materials (GUR-1050 and vitamin E-doped) in an in vitro model system by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry imaging (MSI). Lipids were identified by high performance thin layer chromatography (HP-TLC) and tandem mass spectrometry (MS/MS) analysis, with an analytical focus on phospholipids and cholesterol, both being species of high importance for lubrication. Scanning electron microscopy (SEM) analysis was applied in the study to correlate molecular information with PE-UHMW material qualities. It is demonstrated that lipid adsorption preferentially occurs in rough or oxidized polymer regions. Polymer modifications were colocalized with adsorbed lipids and found with high density in regions identified by SEM. Explanted, the in vivo polymer material showed comparable and even more obvious polymer damage and lipid adsorption when compared with the static in vitro model. A three-dimensional reconstruction of MSI data from consecutive PE-UHMW slices reveals detailed information about the diffusion process of lipids in the acetabular cup and provides, for the first time, a promising starting point for future studies correlating molecular information with commonly used techniques for material analysis (e.g., Fourier-transform infrared spectroscopy, nanoindentation).

Characterization of some biological specimens using TEM and SEM

Science.gov (United States)

Ghosh, Nabarun; Smith, Don W.

2009-05-01

The advent of novel techniques using the Transmission and Scanning Electron Microscopes improved observation on various biological specimens to characterize them. We studied some biological specimens using Transmission and Scanning Electron Microscopes. We followed negative staining technique with Phosphotungstic acid using bacterial culture of Bacillus subtilis. Negative staining is very convenient technique to view the structural morphology of different samples including bacteria, phage viruses and filaments in a cell. We could observe the bacterial cell wall and flagellum very well when trapped the negative stained biofilm from bacterial culture on a TEM grid. We cut ultra thin sections from the fixed root tips of Pisum sativum (Garden pea). Root tips were pre fixed with osmium tetroxide and post fixed with uranium acetate and placed in the BEEM capsule for block making. The ultrathin sections on the grid under TEM showed the granular chromatin in the nucleus. The protein bodies and large vacuoles with the storage materials were conspicuous. We followed fixation, critical point drying and sputter coating with gold to view the tissues with SEM after placing on stubs. SEM view of the leaf surface of a dangerous weed Tragia hispida showed the surface trichomes. These trichomes when break on touching releases poisonous content causing skin irritation. The cultured tissue from in vitro culture of Albizia lebbeck, a tree revealed the regenerative structures including leaf buds and stomata on the tissue surface. SEM and TEM allow investigating the minute details characteristic morphological features that can be used for classroom teaching.

The luminal surface of thyroid cysts in SEM

DEFF Research Database (Denmark)

Zelander, T; Kirkeby, S

1978-01-01

Four of the five kinds of cells constituting the walls of thyroid cysts can be identified in the SEM. These are cuboidal cells, mucous cells, cells with large granules and ciliated cells. A correlation between SEM and TEM observations is attempted.......Four of the five kinds of cells constituting the walls of thyroid cysts can be identified in the SEM. These are cuboidal cells, mucous cells, cells with large granules and ciliated cells. A correlation between SEM and TEM observations is attempted....

In-SEM Raman microspectroscopy coupled with EDX - a case study of uranium reference particles

International Nuclear Information System (INIS)

Stefaniak, Elzbieta A.; Pointurier, Fabien; Marie, Olivier; Truyens, Jan; Aregbe, Yetunde

2014-01-01

Information about the molecular composition of airborne uranium-bearing particles may be useful as an additional tool for nuclear safeguards. In order to combine the detection of micrometer-sized particles with the analysis of their molecular forms, we used a hybrid system enabling Raman microanalysis in high vacuum inside a SEM chamber (SEM-SCA system). The first step involved an automatic scan of a sample to detect and save coordinates of uranium particles, along with X-ray microanalysis. In the second phase, the detected particles were relocated in a white light image and subjected to Raman microanalysis. The consecutive measurements by the two beams showed exceptional fragility of uranium particles, leading to their ultimate damage and change of uranium oxidation state. We used uranium reference particles prepared by hydrolysis of uranium hexafluoride to test the reliability of the Raman measurements inside the high vacuum. The results achieved by the hybrid system were verified by using a standalone Raman micro spectrometer. When deposited on exceptionally smooth substrates, uranyl fluoride particles smaller than 1000 nm could successfully be analyzed with the SEM-SCA system. (authors)

Space Experiment Module (SEM)

Science.gov (United States)

Brodell, Charles L.

1999-01-01

The Space Experiment Module (SEM) Program is an education initiative sponsored by the National Aeronautics and Space Administration (NASA) Shuttle Small Payloads Project. The program provides nationwide educational access to space for Kindergarten through University level students. The SEM program focuses on the science of zero-gravity and microgravity. Within the program, NASA provides small containers or "modules" for students to fly experiments on the Space Shuttle. The experiments are created, designed, built, and implemented by students with teacher and/or mentor guidance. Student experiment modules are flown in a "carrier" which resides in the cargo bay of the Space Shuttle. The carrier supplies power to, and the means to control and collect data from each experiment.

Sexual Arousal and Sexually Explicit Media (SEM): Comparing Patterns of Sexual Arousal to SEM and Sexual Self-Evaluations and Satisfaction Across Gender and Sexual Orientation.

Science.gov (United States)

Hald, Gert Martin; Stulhofer, Aleksandar; Lange, Theis

2018-03-01

Investigations of patterns of sexual arousal to certain groups of sexually explicit media (SEM) in the general population in non-laboratory settings are rare. Such knowledge could be important to understand more about the relative specificity of sexual arousal in different SEM users. (i) To investigate whether sexual arousal to non-mainstream vs mainstream SEM contents could be categorized across gender and sexual orientation, (ii) to compare levels of SEM-induced sexual arousal, sexual satisfaction, and self-evaluated sexual interests and fantasies between non-mainstream and mainstream SEM groups, and (iii) to explore the validity and predictive accuracy of the Non-Mainstream Pornography Arousal Scale (NPAS). Online cross-sectional survey of 2,035 regular SEM users in Croatia. Patterns of sexual arousal to 27 different SEM themes, sexual satisfaction, and self-evaluations of sexual interests and sexual fantasies. Groups characterized by sexual arousal to non-mainstream SEM could be identified across gender and sexual orientation. These non-mainstream SEM groups reported more SEM use and higher average levels of sexual arousal across the 27 SEM themes assessed compared with mainstream SEM groups. Only few differences were found between non-mainstream and mainstream SEM groups in self-evaluative judgements of sexual interests, sexual fantasies, and sexual satisfaction. The internal validity and predictive accuracy of the NPAS was good across most user groups investigated. The findings suggest that in classified non-mainstream SEM groups, patterns of sexual arousal might be less fixated and category specific than previously assumed. Further, these groups are not more judgmental of their SEM-related sexual arousal patterns than groups characterized by patterns of sexual arousal to more mainstream SEM content. Moreover, accurate identification of non-mainstream SEM group membership is generally possible across gender and sexual orientation using the NPAS. Hald GM

High-performance serial block-face SEM of nonconductive biological samples enabled by focal gas injection-based charge compensation.

Science.gov (United States)

Deerinck, T J; Shone, T M; Bushong, E A; Ramachandra, R; Peltier, S T; Ellisman, M H

2018-05-01

A longstanding limitation of imaging with serial block-face scanning electron microscopy is specimen surface charging. This charging is largely due to the difficulties in making biological specimens and the resins in which they are embedded sufficiently conductive. Local accumulation of charge on the specimen surface can result in poor image quality and distortions. Even minor charging can lead to misalignments between sequential images of the block-face due to image jitter. Typically, variable-pressure SEM is used to reduce specimen charging, but this results in a significant reduction to spatial resolution, signal-to-noise ratio and overall image quality. Here we show the development and application of a simple system that effectively mitigates specimen charging by using focal gas injection of nitrogen over the sample block-face during imaging. A standard gas injection valve is paired with a precisely positioned but retractable application nozzle, which is mechanically coupled to the reciprocating action of the serial block-face ultramicrotome. This system enables the application of nitrogen gas precisely over the block-face during imaging while allowing the specimen chamber to be maintained under high vacuum to maximise achievable SEM image resolution. The action of the ultramicrotome drives the nozzle retraction, automatically moving it away from the specimen area during the cutting cycle of the knife. The device described was added to a Gatan 3View system with minimal modifications, allowing high-resolution block-face imaging of even the most charge prone of epoxy-embedded biological samples. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

Elevated temperature transmission Kikuchi diffraction in the SEM

DEFF Research Database (Denmark)

Fanta, Alice Bastos; Todeschini, Matteo; Burrows, Andrew

2018-01-01

heating associated with this system enables reliable TKD measurements at elevated temperatures without notable disturbance from infrared radiation. The dewetting of an Au thin film into Au nanoparticles upon heating is followed with orientation mapping in a temperature range between 20 °C and 900 °C....... The local thickness variation associated with the dewetting is observed qualitatively by observing the intensity of the transmitted beam, which decreases as the film thickness increases locally. The results of this study reveal that TKD is a well suited technique to study thin-film stability and solid state...... dewetting. Moreover, the outcome of this methodological study provides a baseline for further in-situ crystallographic studies of electron transparent samples in the SEM....

SEM and AFM studies of dip-coated CuO nanofilms.

Science.gov (United States)

Dhanasekaran, V; Mahalingam, T; Ganesan, V

2013-01-01

Cupric oxide (CuO) semiconducting thin films were prepared at various copper sulfate concentrations by dip coating. The copper sulfate concentration was varied to yield films of thicknesses in the range of 445-685 nm by surface profilometer. X-ray diffraction patterns revealed that the deposited films were polycrystalline in nature with monoclinic structure of (-111) plane. The surface morphology and topography of monoclinic-phase CuO thin films were examined using scanning electron microscopy (SEM) and atomic force microscopy (AFM), respectively. Surface roughness profile was plotted using WSxM software and the estimated surface roughness was about ∼19.4 nm at 30 mM molar concentration. The nanosheets shaped grains were observed by SEM and AFM studies. The stoichiometric compound formation was observed at 30 mM copper sulfate concentration prepared film by EDX. The indirect band gap energy of CuO films was increased from 1.08 to 1.20 eV with the increase of copper sulfate concentrations. Copyright © 2012 Wiley Periodicals, Inc.

Does your SEM really tell the truth? How would you know? Part 2.

Science.gov (United States)

Postek, Michael T; Vladár, András E; Purushotham, Kavuri P

2014-01-01

The scanning electron microscope (SEM) has gone through a tremendous evolution to become indispensable for many and diverse scientific and industrial applications. The improvements have significantly enriched and augmented the overall SEM performance and have made the instrument far easier to operate. But, the ease of operation also might lead, through operator complacency, to poor results. In addition, the user friendliness has seemingly reduced the need for thorough operator training for using these complex instruments. One might then conclude that the SEM is just a very expensive digital camera or another peripheral device for a computer. Hence, a person using the instrument may be lulled into thinking that all of the potential pitfalls have been eliminated and they believe everything they see on the micrograph is always correct. But, this may not be the case. An earlier paper (Part 1), discussed some of the potential issues related to signal generation in the SEM, instrument calibration, electron beam interactions and the need for physics-based modeling to understand the actual image formation mechanisms. All these were summed together in a discussion of how these issues effect measurements made with the instrument. This second paper discusses another major issue confronting the microscopist: electron-beam-induced specimen contamination. Over the years, NIST has done a great deal of research into the issue of sample contamination and its removal and elimination and some of this work is reviewed and discussed here. © 2013 Wiley Periodicals, Inc.

[18F]DPA 714 PET Imaging Reveals Global Neuroinflammation in Zika Virus Infected Mice

Science.gov (United States)

2017-09-12

with neurotropic viruses and the evaluation of therapeutics being developed for treatment of infectious diseases. Keywords: Zika virus , Animal...18F]DPA-714 PET Imaging Reveals Global Neuroinflammation in Zika Virus - Infected Mice Kyle Kuszpit1†, Bradley S. Hollidge2†, Xiankun Zeng3, Robert...Running Head: PET Imaging of Zika Virus -Induced Neuroinflammation Manuscript Category: Article Affiliations: 1Molecular and Translational

Secondary emission monitor (SEM) grids.

CERN Multimedia

Patrice Loïez

2002-01-01

A great variety of Secondary Emission Monitors (SEM) are used all over the PS Complex. At other accelerators they are also called wire-grids, harps, etc. They are used to measure beam density profiles (from which beam size and emittance can be derived) in single-pass locations (not on circulating beams). Top left: two individual wire-planes. Top right: a combination of a horizontal and a vertical wire plane. Bottom left: a ribbon grid in its frame, with connecting wires. Bottom right: a SEM-grid with its insertion/retraction mechanism.

Risk assessment of heavy metals in Vembanad Lake sediments (south-west coast of India), based on acid-volatile sulfide (AVS)-simultaneously extracted metal (SEM) approach.

Science.gov (United States)

Shyleshchandran, Mohanachandran Nair; Mohan, Mahesh; Ramasamy, Eswara Venkatesaperumal

2018-03-01

Contamination of estuarine system due to heavy metals is a severe issue in tropical countries, especially in India. For the evaluation of the risk due to heavy metals, the current study assessed spatial and temporal variation of acid-volatile sulfide (AVS), simultaneously extracted metal (SEM), and total metal concentration as toxicity indicator of aquatic sediments in Vembanad Lake System (VLS), India. Surface sediment samples collected from 12 locations from the northern portion of VLS for 4 years during different seasons. The results suggest, in post-monsoon season, 91% of the sampling locations possessed high bioavailability of metals and results in toxicity to aquatic biota. The average seasonal distribution of SEM during the period of observations was in the order post-monsoon > pre-monsoon > monsoon (1.76 ± 2.00 > 1.35 ± 0.60 > 0.80 ± 0.54 μmol/g). The concentration of individual metals on ∑SEM are in the order SEM Zn > SEM Cu> SEM Cd ≈ SEM Pb > SEM Hg. Considering annual ΣSEM/AVS ratio, 83% of the sites cross the critical value of 'One,' reveals that active sulfide phase of the sediment for fixing the metals is saturated. The molar ratio (differences between SEM and AVS) and its normalized organic carbon ratio reveals that in the post-monsoon season, about 42% of the sites are in the category of adverse effects are possible. The study suggests the toxicity and mobility of the metals largely depend on the available AVS, and the current situation may pose harm to benthic organisms.

Neural Network for Nanoscience Scanning Electron Microscope Image Recognition.

Science.gov (United States)

Modarres, Mohammad Hadi; Aversa, Rossella; Cozzini, Stefano; Ciancio, Regina; Leto, Angelo; Brandino, Giuseppe Piero

2017-10-16

In this paper we applied transfer learning techniques for image recognition, automatic categorization, and labeling of nanoscience images obtained by scanning electron microscope (SEM). Roughly 20,000 SEM images were manually classified into 10 categories to form a labeled training set, which can be used as a reference set for future applications of deep learning enhanced algorithms in the nanoscience domain. The categories chosen spanned the range of 0-Dimensional (0D) objects such as particles, 1D nanowires and fibres, 2D films and coated surfaces, and 3D patterned surfaces such as pillars. The training set was used to retrain on the SEM dataset and to compare many convolutional neural network models (Inception-v3, Inception-v4, ResNet). We obtained compatible results by performing a feature extraction of the different models on the same dataset. We performed additional analysis of the classifier on a second test set to further investigate the results both on particular cases and from a statistical point of view. Our algorithm was able to successfully classify around 90% of a test dataset consisting of SEM images, while reduced accuracy was found in the case of images at the boundary between two categories or containing elements of multiple categories. In these cases, the image classification did not identify a predominant category with a high score. We used the statistical outcomes from testing to deploy a semi-automatic workflow able to classify and label images generated by the SEM. Finally, a separate training was performed to determine the volume fraction of coherently aligned nanowires in SEM images. The results were compared with what was obtained using the Local Gradient Orientation method. This example demonstrates the versatility and the potential of transfer learning to address specific tasks of interest in nanoscience applications.

Comparative SEM analysis of nine F22 aligner cleaning strategies.

Science.gov (United States)

Lombardo, Luca; Martini, Marco; Cervinara, Francesca; Spedicato, Giorgio Alfredo; Oliverio, Teresa; Siciliani, Giuseppe

2017-12-01

The orthodontics industry has paid great attention to the aesthetics of orthodontic appliances, seeking to make them as invisible as possible. There are several advantages to clear aligner systems, including aesthetics, comfort, chairside time reduction, and the fact that they can be removed for meals and oral hygiene procedures. Five patients were each given a series of F22 aligners, each to be worn for 14 days and nights, with the exception of meal and brushing times. Patients were instructed to clean each aligner using a prescribed strategy, and sections of the used aligners were observed under SEM. One grey-scale SEM image was saved per aligner in JPEG format with an 8-bit colour depth, and a total of 45 measurements on the grey scale ("Value" variable) were made. This dataset was analysed statistically via repeated measures ANOVA to determine the effect of each of the nine cleaning strategies in each of the five patients. A statistically significant difference in the efficacy of the cleaning strategies was detected. Specifically, rinsing with water alone was significantly less efficacious, and a combination of cationic detergent solution and ultrasonication was significantly more efficacious than the other methods (p aligners.

Self-esteem in adult prison population: The development and validation of the Self-Esteem Measure for Prisoners (SEM-P)

OpenAIRE

Debowska, Agata; Boduszek, Daniel; Sherretts, Nicole

2016-01-01

The main aim of the current study was to develop and validate the Self-Esteem Measure for Prisoners (SEM-P), composed of personal and prison self-esteem, among a systematically selected sample of prisoners (N = 1,794). Confirmatory factor analyses revealed that the SEM-P was best captured with the bifactor conceptualization reflecting two grouping factors (personal and prison self-esteem) and one general factor. Although factor loadings were stronger for the general factor, the two grouping f...

Bases de Datos Semánticas

Directory of Open Access Journals (Sweden)

Irving Caro Fierros

2016-12-01

Full Text Available En 1992, cuando Tim Berners-Lee dio a conocer la primera  versión  de  la  Web,  su  visión  a  futuro  era  incorporar metadatos  con  información  semántica  en  las  páginas  Web.  Es precisamente   a   principios   de   este   siglo   que   inicia   el   auge repentino  de  la  Web  semántica  en  el  ambiente  académico  e Internet. El modelo de datos semántico se define como un modelo conceptual que permite definir el significado de los datos a través de  sus  relaciones  con  otros.  En  este  sentido,  el  formato  de representación  de  los  datos  es  fundamental  para  proporcionar información de carácter semántico. La tecnología enfocada en las bases de datos semánticas se encuentra actualmente en un punto de  inflexión,  al  pasar  del  ámbito  académico  y  de  investigación  a ser una opción comercial completa. En este artículo se realiza un análisis  del  concepto  de  base  de  datos  semántica.  También  se presenta  un  caso  de  estudio  donde  se  ejemplifican  operaciones básicas  que  involucran  la  gestión  de  la  información  almacenada en este tipo de base de datos.

Synchrotron soft X-ray imaging and fluorescence microscopy reveal novel features of asbestos body morphology and composition in human lung tissues

Directory of Open Access Journals (Sweden)

Polentarutti Maurizio

2011-02-01

Full Text Available Abstract Background Occupational or environmental exposure to asbestos fibres is associated with pleural and parenchymal lung diseases. A histopathologic hallmark of exposure to asbestos is the presence in lung parenchyma of the so-called asbestos bodies. They are the final product of biomineralization processes resulting in deposition of endogenous iron and organic matter (mainly proteins around the inhaled asbestos fibres. For shedding light on the formation mechanisms of asbestos bodies it is of fundamental importance to characterize at the same length scales not only their structural morphology and chemical composition but also to correlate them to the possible alterations in the local composition of the surrounding tissues. Here we report the first correlative morphological and chemical characterization of untreated paraffinated histological lung tissue samples with asbestos bodies by means of soft X-ray imaging and X-Ray Fluorescence (XRF microscopy, which reveals new features in the elemental lateral distribution. Results The X-ray absorption and phase contrast images and the simultaneously monitored XRF maps of tissue samples have revealed the location, distribution and elemental composition of asbestos bodies and associated nanometric structures. The observed specific morphology and differences in the local Si, Fe, O and Mg content provide distinct fingerprints characteristic for the core asbestos fibre and the ferruginous body. The highest Si content is found in the asbestos fibre, while the shell and ferruginous bodies are characterized by strongly increased content of Mg, Fe and O compared to the adjacent tissue. The XRF and SEM-EDX analyses of the extracted asbestos bodies confirmed an enhanced Mg deposition in the organic asbestos coating. Conclusions The present report demonstrates the potential of the advanced synchrotron-based X-ray imaging and microspectroscopy techniques for studying the response of the lung tissue to the

Partial Least Squares Strukturgleichungsmodellierung (PLS-SEM)

DEFF Research Database (Denmark)

Hair, Joseph F.; Hult, G. Tomas M.; Ringle, Christian M.

(PLS-SEM) hat sich in der wirtschafts- und sozialwissenschaftlichen Forschung als geeignetes Verfahren zur Schätzung von Kausalmodellen behauptet. Dank der Anwenderfreundlichkeit des Verfahrens und der vorhandenen Software ist es inzwischen auch in der Praxis etabliert. Dieses Buch liefert eine...... anwendungsorientierte Einführung in die PLS-SEM. Der Fokus liegt auf den Grundlagen des Verfahrens und deren praktischer Umsetzung mit Hilfe der SmartPLS-Software. Das Konzept des Buches setzt dabei auf einfache Erläuterungen statistischer Ansätze und die anschauliche Darstellung zahlreicher Anwendungsbeispiele anhand...... einer einheitlichen Fallstudie. Viele Grafiken, Tabellen und Illustrationen erleichtern das Verständnis der PLS-SEM. Zudem werden dem Leser herunterladbare Datensätze, Aufgaben und weitere Fachartikel zur Vertiefung angeboten. Damit eignet sich das Buch hervorragend für Studierende, Forscher und...

SIMS imaging of gadolinium isotopes in tissue from Nephrogenic Systemic Fibrosis patients: Release of free Gd from magnetic resonance imaging (MRI) contrast agents

Energy Technology Data Exchange (ETDEWEB)

Abraham, Jerrold L. [Department of Pathology, SUNY Upstate Medical University, Syracuse, New York (United States); Chandra, Subhash [Cornell SIMS Laboratory, Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY 14853 (United States)], E-mail: sc40@cornell.edu; Thakral, Charu [Department of Pathology, SUNY Upstate Medical University, Syracuse, New York (United States); Abraham, Joshua M. [Cornell SIMS Laboratory, Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY 14853 (United States)

2008-12-15

Recently, Gd-based magnetic resonance imaging (MRI) contrast agents (GBMCA) have been linked to a new disease, Nephrogenic Systemic Fibrosis (NSF), with skin and systemic toxicity and death in certain patients with renal failure. Due to widespread use of GBMCA in diagnostic MRI, it is essential to study their excretion, metabolism, and target sites in cells and tissues. A CAMECA IMS-3f SIMS ion microscope and scanning electron microscopy (SEM) with energy dispersive X-ray spectroscopy (EDS) were used for imaging Gd isotopes in relation to calcium distributions in histologic sections of human tissues. SIMS imaging revealed two types of Gd localization in skin biopsies of patients who received GBMCA. The Gd was present in micrometer size deposits in association with calcium, and in detectable amounts in a more diffuse cellular distribution. Only the Gd-containing deposits associated with Ca and P were detectable using SEM/EDS. As only insoluble deposits remain in the biopsy tissues after aqueous and organic solvent processing of the tissue, our observations support release of free Gd from the GBMCA and selective localization of insoluble Gd in the target tissue from patients with NSF. This study opens new novel applications of SIMS for characterization of the safety of GBMCA.

Chemical Characterization of Bed Material Coatingsby LA-ICP-MS and SEM-EDS

Science.gov (United States)

Piispanen, M. H.; Mustonen, A. J.; Tiainen, M. S.; Laitinen, R. S.

Bed material coatings and the consequent agglomeration of bed material are main ash-related problems in FB-boilers. The bed agglomeration is a particular problem when combusting biofuels and waste materials. Whereas SEM-EDS together with automated image processing has proven to be a convenient method to study compositional distribution in coating layers and agglomerates, it is a relatively expensive technique and is not necessarily widely available. In this contribution, we explore the suitability of LA-ICP-MS to provide analogous information of the bed.

Sem-edx and ftir studies of chlorinated rubber coating

International Nuclear Information System (INIS)

Bano, H.; Khan, M.I.

2013-01-01

Summary: Anticorrosive performance of chlorinated rubber coating has been investigated by visual examination, Scanning electron microscopy (SEM)/Energy dispersive X-ray (EDX) analysis and Fourier transform infrared (FTIR) spectroscopy. After surface preparation, commercially available coating system based on chlorinated rubber (primer)/chlorinated rubber (topcoat) formulation was applied on mild steel test panels (10cm x 15cm sizes). Prepared coated panels were exposed at marine, industrial and urban test sites located in Karachi, Pakistan according to ISO 8565 norm. Accelerated testing was performed by using a salt spray chamber (ASTM B117 norm). Accelerated weathering methods are the methods in which the factors responsible for the degradation of coatings are artificially intensified in order to achieve the rapid degradation of coatings. Visual examination of blistering and rusting as well as SEM micrographs indicated a more severe degradation of the coating surface characteristics at natural exposure testing sites (particularly at marine test site) than for accelerated (salt spray) testing. EDX determination of the Oxygen/Carbon (O/C) ratios also indicated increased degradation at natural test sites compared to the accelerated (salt spray) testing. Photooxidation of the binder results in the formation of carbonyl compounds as revealed by FTIR spectroscopy which also indicated dehydrochlorination. (author)

Generating 3D and 3D-like animations of strongly uneven surface microareas of bloodstains from small series of partially out-of-focus digital SEM micrographs.

Science.gov (United States)

Hortolà, Policarp

2010-01-01

When dealing with microscopic still images of some kinds of samples, the out-of-focus problem represents a particularly serious limiting factor for the subsequent generation of fully sharp 3D animations. In order to produce fully-focused 3D animations of strongly uneven surface microareas, a vertical stack of six digital secondary-electron SEM micrographs of a human bloodstain microarea was acquired. Afterwards, single combined images were generated using a macrophotography and light microscope image post-processing software. Subsequently, 3D animations of texture and topography were obtained in different formats using a combination of software tools. Finally, a 3D-like animation of a texture-topography composite was obtained in different formats using another combination of software tools. By one hand, results indicate that the use of image post-processing software not concerned primarily with electron micrographs allows to obtain, in an easy way, fully-focused images of strongly uneven surface microareas of bloodstains from small series of partially out-of-focus digital SEM micrographs. On the other hand, results also indicate that such small series of electron micrographs can be utilized for generating 3D and 3D-like animations that can subsequently be converted into different formats, by using certain user-friendly software facilities not originally designed for use in SEM, that are easily available from Internet. Although the focus of this study was on bloodstains, the methods used in it well probably are also of relevance for studying the surface microstructures of other organic or inorganic materials whose sharp displaying is difficult of obtaining from a single SEM micrograph.

Fast three-dimensional nanoscale metrology in dual-beam FIB-SEM instrumentation

International Nuclear Information System (INIS)

Repetto, Luca; Buzio, Renato; Denurchis, Carlo; Firpo, Giuseppe; Piano, Emanuele; Valbusa, Ugo

2009-01-01

A quantitative surface reconstruction technique has been developed for the geometric characterization of three-dimensional structures by using a combined focused ion beam-scanning electron microscopy (FIB-SEM) instrument. A regular pattern of lines is milled at normal incidence on the sample to be characterized and an image is acquired at a large tilt angle. By analyzing the pattern under the tilted view, a quantitative estimation of surface heights is obtained. The technique has been applied to a test sample and nanoscale resolution has been achieved. The reported results are validated by a comparison with atomic force microscopy measurements.

Imaging of Norway spruce early somatic embryos with the ESEM, Cryo-SEM and laser scanning microscope

Czech Academy of Sciences Publication Activity Database

Neděla, Vilém; Hřib, Jiří; Havel, L.; Hudec, Jiří; Runštuk, Jiří

2016-01-01

Roč. 84, May 2016 (2016), s. 67-71 ISSN 0968-4328 R&D Projects: GA ČR(CZ) GA14-22777S Institutional support: RVO:68081731 Keywords : ESEM * Cryo-SEM * bright field/dark field microscopy * extracellular matrix * Picea abies * somatic embryogenesis Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.980, year: 2016

Bases de Datos Semánticas

OpenAIRE

Irving Caro Fierros; Víctor Hugo Menéndez Domínguez; María Enriqueta Castellanos Bolaños

2016-01-01

En 1992, cuando Tim Berners-Lee dio a conocer la primera  versión  de  la  Web,  su  visión  a  futuro  era  incorporar metadatos  con  información  semántica  en  las  páginas  Web.  Es precisamente   a   principios   de   este   siglo   que   inicia   el   auge repentino  de  la  Web  semántica  en  el  ambiente  académico  e Internet. El modelo de datos semántico se define como un modelo conceptual que permite definir el significado de los datos a través de  sus  relaciones  con  otros.  E...

Structure and Novel Biomineralization of Mnemiopsis Leidyi and Beroe Ovata Lithocyte Concretions (lcs) as Revealed by Polarization Lc-Pol Scanning Electron Microscopy (sem) and Electron Dispersion Spectroscopy (eds)

Science.gov (United States)

Moss, A.

2016-02-01

Ctenophore statocysts have multicellular statoliths borne on the tips of balancer compound cilia (Curr. Biol. 24:R951; Biol. Bull. 227:7). Lithocyte concretions (LCs) were prepared by three methods: 1) statocysts were microsurgically collected and washed w/0.2 µm filtered sea water (FSW), followed by 5 diH2O rinses in a deep well dish (DWD); 2) statocysts were treated with 50% Chlorox/FSW to release the statolith/LCs; 3) statocysts were fixed in 2.5% glutaraldehyde or 1% paraformaldehyde-2.5% glutaraldehyde in 10 mM pH 7.8 HEPES-buffered FSW, and statoliths and LCs microsurgically released. LCs for SEM were glued to stubs, C-stabilized and Pt-coated to a thickness of 8 nm and viewed at 10 kVe. LCs for EDS were applied to carbon tape on aluminum stubs and analyzed by EDS at 3 and 10 kVe. SEM and EDS were performed on a Zeiss Supra 40 VP equipped with an EDS detector controlled by INCA software (Oxford). Results were compared against compounds of known elemental composition. LCs examined by LC-POL revealed no birefringence (BR). LCs viewed by SEM were either a lumpy mass (M. leidyi) or smooth ellipsoid (B. ovata). LCs on carbon tape typically shattered and released overlapping, layered, multi-oriented crystals. EDS of LC crystals from both species collected by all methods lacked Ca, Mn and Mg. Predominant elements were Na, K, O and S in ratios suggesting that LCs contain mixed sodium/potassium sulfates. The unique composition of ctenophore statoliths may have been critical for the 600+ million years persistence of these organisms (J. exp. Biol. 218:592) including survival through multiple global extinctions and related ocean acidifications. Thanks to L. Kerr, R. Oldenbourg, S. Mehta, A. Verma, M. Tran, A. Kuzirian and S. Tamm for stimulating discussion and technical advice. EDS stds compounds were curtesy of L. Amaral-Zettler, J. Huber and K. Gribble (Bay Paul Center/MBL). Funding: AU PIL Program, NSF-EPS-1158862.

Pseudo Prune Belly Syndrome: Diagnosis Revealed by Imaging - A Case Report and Brief Review.

Science.gov (United States)

Grover, Hemal; Sethi, Sanjay; Garg, Jatin; Ahluwalia, Amrit Pal

2017-01-01

Prune Belly Syndrome (PBS) is a rare entity, usually found in male neonates. It comprises complex urinary tract anomalies, bilateral undescended testis and absence of anterior abdominal wall muscles. Patients with unilateral abdominal wall deficiency, unilateral undescended testis and female neonates with abdominal wall laxity are classified as Pseudo Prune Belly syndrome (PPBS). Reports on PPBS do not highlight the radiological and imaging characteristics of this syndrome and the current literature on the role of newer imaging modalities, such as Magnetic Resonance Imaging (MRI), remains relatively sparse. We describe a new case of PPBS and emphasize the role of imaging, especially ultrasound and MRI in the process of diagnosis and briefly review the subject. A male infant of four months of age was referred for evaluation of left-sided cryptorchidism. Clinical examination revealed laxity of the left abdominal wall. Ultrasound examination of the abdomen, pelvis and scrotum was performed together with routine laboratory tests. Ultrasound examination was followed by intravenous urography, voiding cysto-urethrography and MRI of the abdomen. On ultrasound, the left testis was located in the inguinal canal, the right kidney was slightly enlarged and the left kidney could not be localized. Ultrasound appearances suggested chronic obstruction in the urinary bladder. Intravenous urography, voiding cysto-urethrography and MRI confirmed the ultrasound diagnosis and also revealed a left dysplastic kidney with a dilated, tortuous ureter. Clinical and imaging features were consistent with pseudo prune belly syndrome (PPBS). We report a new occurrence of PPBS, a rare entity. The imaging approach for a comprehensive evaluation of the renal system in PPBS, especially with MRI, is emphasized.

Epigallocatechin-3-gallate rapidly remodels PAP85-120, SEM1(45-107, and SEM2(49-107 seminal amyloid fibrils

Directory of Open Access Journals (Sweden)

Laura M. Castellano

2015-09-01

Full Text Available Semen harbors amyloid fibrils formed by proteolytic fragments of prostatic acid phosphatase (PAP248-286 and PAP85-120 and semenogelins (SEM1 and SEM2 that potently enhance HIV infectivity. Amyloid but not soluble forms of these peptides enhance HIV infection. Thus, agents that remodel these amyloid fibrils could prevent HIV transmission. Here, we confirm that the green tea polyphenol, epigallocatechin-3-gallate (EGCG, slowly remodels fibrils formed by PAP248-286 termed SEVI (semen derived enhancer of viral infection and also exerts a direct anti-viral effect. We elucidate for the first time that EGCG remodels PAP85-120, SEM1(45-107, and SEM2(49-107 fibrils more rapidly than SEVI fibrils. We establish EGCG as the first small molecule that can remodel all four classes of seminal amyloid. The combined anti-amyloid and anti-viral properties of EGCG could have utility in preventing HIV transmission.

由SEM-EBSP能知道些什么

Institute of Scientific and Technical Information of China (English)

张唯敏

2003-01-01

@@ 1 SEM-EBSP是什么 所谓SEM-EBSP是指采用在扫描电子显微镜(SEM)镜体中的反射电子菊池线衍射的结晶方位分析.被称为菊池图形的衍射图形可因结晶的稍许倾斜而大大地改变其位置,因此,通过解析菊池图形就能正确地知道结晶方位.

Stirling Energy Module (SEM) as Micro-CHP; Stirling Energy Module (SEM) als Mini-BHKW

Energy Technology Data Exchange (ETDEWEB)

Schlegel, A.

2006-07-01

Since many years, a lot of effort is being put into the development of combined heat and power units (CHP) for the decentralised production of electric power. For long time, the main focus was on fuel cells. In the meantime, the Stirling technology, which is based upon classical mechanical engineering and innovative technical concepts, proceeded in its development as well. The following article describes the technology and the actual state of the development of the Stirling Energy Module (SEM) for the application as Micro-CHP in one-family-houses. SEM is based on a free-piston engine with a linear power generator, producing electric power while heating. The Stirling engine is planned the be introduced into the market as a replacement for the conventional heating systems within a couple of years. (author)

Deep machine learning based Image classification in hard disk drive manufacturing (Conference Presentation)

Science.gov (United States)

Rana, Narender; Chien, Chester

2018-03-01

A key sensor element in a Hard Disk Drive (HDD) is the read-write head device. The device is complex 3D shape and its fabrication requires over thousand process steps with many of them being various types of image inspection and critical dimension (CD) metrology steps. In order to have high yield of devices across a wafer, very tight inspection and metrology specifications are implemented. Many images are collected on a wafer and inspected for various types of defects and in CD metrology the quality of image impacts the CD measurements. Metrology noise need to be minimized in CD metrology to get better estimate of the process related variations for implementing robust process controls. Though there are specialized tools available for defect inspection and review allowing classification and statistics. However, due to unavailability of such advanced tools or other reasons, many times images need to be manually inspected. SEM Image inspection and CD-SEM metrology tools are different tools differing in software as well. SEM Image inspection and CD-SEM metrology tools are separate tools differing in software and purpose. There have been cases where a significant numbers of CD-SEM images are blurred or have some artefact and there is a need for image inspection along with the CD measurement. Tool may not report a practical metric highlighting the quality of image. Not filtering CD from these blurred images will add metrology noise to the CD measurement. An image classifier can be helpful here for filtering such data. This paper presents the use of artificial intelligence in classifying the SEM images. Deep machine learning is used to train a neural network which is then used to classify the new images as blurred and not blurred. Figure 1 shows the image blur artefact and contingency table of classification results from the trained deep neural network. Prediction accuracy of 94.9 % was achieved in the first model. Paper covers other such applications of the deep neural

Whole mount nuclear fluorescent imaging: convenient documentation of embryo morphology.

Science.gov (United States)

Sandell, Lisa L; Kurosaka, Hiroshi; Trainor, Paul A

2012-11-01

Here, we describe a relatively inexpensive and easy method to produce high quality images that reveal fine topological details of vertebrate embryonic structures. The method relies on nuclear staining of whole mount embryos in combination with confocal microscopy or conventional wide field fluorescent microscopy. In cases where confocal microscopy is used in combination with whole mount nuclear staining, the resulting embryo images can rival the clarity and resolution of images produced by scanning electron microscopy (SEM). The fluorescent nuclear staining may be performed with a variety of cell permeable nuclear dyes, enabling the technique to be performed with multiple standard microscope/illumination or confocal/laser systems. The method may be used to document morphology of embryos of a variety of organisms, as well as individual organs and tissues. Nuclear stain imaging imposes minimal impact on embryonic specimens, enabling imaged specimens to be utilized for additional assays. Copyright © 2012 Wiley Periodicals, Inc.

New Insights on Subsurface Imaging of Carbon Nanotubes in Polymer Composites via Scanning Electron Microscopy

Science.gov (United States)

Zhao, Minhua; Ming, Bin; Kim, Jae-Woo; Gibbons, Luke J.; Gu, Xiaohong; Nguyen, Tinh; Park, Cheol; Lillehei, Peter T.; Villarrubia, J. S.; Vladar, Andras E.;

On the Progress of Scanning Transmission Electron Microscopy (STEM) Imaging in a Scanning Electron Microscope.

Science.gov (United States)

Sun, Cheng; Müller, Erich; Meffert, Matthias; Gerthsen, Dagmar

2018-04-01

Transmission electron microscopy (TEM) with low-energy electrons has been recognized as an important addition to the family of electron microscopies as it may avoid knock-on damage and increase the contrast of weakly scattering objects. Scanning electron microscopes (SEMs) are well suited for low-energy electron microscopy with maximum electron energies of 30 keV, but they are mainly used for topography imaging of bulk samples. Implementation of a scanning transmission electron microscopy (STEM) detector and a charge-coupled-device camera for the acquisition of on-axis transmission electron diffraction (TED) patterns, in combination with recent resolution improvements, make SEMs highly interesting for structure analysis of some electron-transparent specimens which are traditionally investigated by TEM. A new aspect is correlative SEM, STEM, and TED imaging from the same specimen region in a SEM which leads to a wealth of information. Simultaneous image acquisition gives information on surface topography, inner structure including crystal defects and qualitative material contrast. Lattice-fringe resolution is obtained in bright-field STEM imaging. The benefits of correlative SEM/STEM/TED imaging in a SEM are exemplified by structure analyses from representative sample classes such as nanoparticulates and bulk materials.

Application of FE-SEM with elemental analyzer for irradiated fuel materials

International Nuclear Information System (INIS)

Sasaki, Shinji; Maeda, Koji; Yamada, A.

2012-01-01

It is important to study the irradiation behavior of the uranium-plutonium mixed oxide fuels (MOX fuels) for development of fast reactor fuels. During irradiation in a fast reactor, the changes of microstructures and the changes of element distributions along radial direction occur in the MOX fuels because of a radial temperature gradient. In order to make detailed observations of microstructure and elemental analyses of fuel samples, a field emission scanning electron microscope (FE-SEM) equipped with a wavelength-dispersive X-ray spectrometer (WDX) and an energy-dispersive X-ray spectrometer (EDX) were installed in a hot laboratory. Because fuel samples have high radioactivities and emit α-particles, the instrument was modified correspondingly. The notable modified points were as follows. 1) To prevent leakage of radioactive materials, the instrument was attached to a remote control air-tight sample transfer unit between a shielded hot cell and the FE-SEM. 2) To protect operators and the instruments from radiation, the FE-SEM was installed in a lead shield box and the control unit was separately located outside the box. After the installation, the microscopy and elemental analyses were made on low burnup fuel samples. High resolution images were obtained on the fuel sample surface. The characteristic X-rays (U, Pu) emitted from the fuel sample surface measured along radial direction successfully. Thereby, it was able to grasp the change of U, Pu radial distribution after irradiation. The technique has the great advantage of being able to evaluate the changes of microstructures and the changes of element distributions of MOX fuels due to irradiation. In future work, samples of even higher radioactivity will be observed and analyzed. (author)

Tumor suppressor protein SMAR1 modulates the roughness of cell surface: combined AFM and SEM study

Directory of Open Access Journals (Sweden)

Mamgain Hitesh

2009-10-01

Full Text Available Abstract Background Imaging tools such as scanning electron microscope (SEM and atomic force microscope (AFM can be used to produce high-resolution topographic images of biomedical specimens and hence are well suited for imaging alterations in cell morphology. We have studied the correlation of SMAR1 expression with cell surface smoothness in cell lines as well as in different grades of human breast cancer and mouse tumor sections. Methods We validated knockdown and overexpression of SMAR1 using RT-PCR as well as Western blotting in human embryonic kidney (HEK 293, human breast cancer (MCF-7 and mouse melanoma (B16F1 cell lines. The samples were then processed for cell surface roughness studies using atomic force microscopy (AFM and scanning electron microscopy (SEM. The same samples were used for microarray analysis as well. Tumors sections from control and SMAR1 treated mice as well as tissues sections from different grades of human breast cancer on poly L-lysine coated slides were used for AFM and SEM studies. Results Tumor sections from mice injected with melanoma cells showed pronounced surface roughness. In contrast, tumor sections obtained from nude mice that were first injected with melanoma cells followed by repeated injections of SMAR1-P44 peptide, exhibited relatively smoother surface profile. Interestingly, human breast cancer tissue sections that showed reduced SMAR1 expression exhibited increased surface roughness compared to the adjacent normal breast tissue. Our AFM data establishes that treatment of cells with SMAR1-P44 results into increase in cytoskeletal volume that is supported by comparative gene expression data showing an increase in the expression of specific cytoskeletal proteins compared to the control cells. Altogether, these findings indicate that tumor suppressor function of SMAR1 might be exhibited through smoothening of cell surface by regulating expression of cell surface proteins. Conclusion Tumor suppressor

A combined technique using SEM and TOPSIS for the commercialization capability of R&D project evaluation

Directory of Open Access Journals (Sweden)

Charttirot Karaveg

2015-07-01

Full Text Available There is a high risk of R&D based innovation being commercialized, especially in the innovation transfer process which is a concern to many entrepreneurs and researchers. The purpose of this research is to develop the criteria of R&D commercialization capability and to propose a combined technique of Structural Equation Modelling (SEM and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS for R&D project evaluation. The research utilized a mixed-method approach. The first phase comprised a qualitative study on commercialization criteria development though the survey research of 272 successful entrepreneurs and researchers in all industrial sectors in Thailand. The data was collected with a structured questionnaire and analyzed by SEM. The second phase was involved with SEM-TOPSIS technique development and a case study of 45 R&D projects in research institutes and incubators for technique validation. The research results reveal that there were six criteria for R&D project commercialization capability, these are arranged according to the significance; marketing, technology, finance, non-financial impact, intellectual property, and human resource. The holistic criteria is presented in decreasing order on the ambiguous subjectivity of the fuzzy-expert system, to help with effectively funding R&D and to prevent a resource meltdown. This study applies SEM to the relative weighting of hierarchical criteria. The TOPSIS approach is employed to rank the alternative performance. An integrated SEM-TOPSIS is proposed for the first time and applied to present R&D projects shown to be effective and feasible in evaluating R&D commercialization capacity.

A Data-Driven Approach to SEM Development at a Two-Year College

Science.gov (United States)

Pirius, Landon K.

2014-01-01

This article explores implementation of strategic enrollment management (SEM) at a two-year college and why SEM is critical to the long-term viability of an institution. This article also outlines the five initial steps needed to implement SEM, including identifying SEM leadership, building a SEM committee, developing a common understanding of…

3-D Analysis of Graphite Nodules in Ductile Cast Iron Using FIB-SEM

DEFF Research Database (Denmark)

D'Angelo, Luca; Jespersen, Freja N.; MacDonald, A. Nicole

Ductile cast iron samples were analysed in a Focused Ion Beam Scanning Electron Microscope, FIB-SEM. The focussed ion beam was used to carefully remove layers of the graphite nodules to reveal internal structures in the nodules. The sample preparation and milling procedure for sectioning graphite...... inside the nodules, their orientation in relation to the graphite and the chemistry of the inclusions is analysed and described. Formation of the structures during solidification and subsequent cooling to room temperature is discussed....

A methodology for extending domain coverage in SemRep.

Science.gov (United States)

Rosemblat, Graciela; Shin, Dongwook; Kilicoglu, Halil; Sneiderman, Charles; Rindflesch, Thomas C

2013-12-01

We describe a domain-independent methodology to extend SemRep coverage beyond the biomedical domain. SemRep, a natural language processing application originally designed for biomedical texts, uses the knowledge sources provided by the Unified Medical Language System (UMLS©). Ontological and terminological extensions to the system are needed in order to support other areas of knowledge. We extended SemRep's application by developing a semantic representation of a previously unsupported domain. This was achieved by adapting well-known ontology engineering phases and integrating them with the UMLS knowledge sources on which SemRep crucially depends. While the process to extend SemRep coverage has been successfully applied in earlier projects, this paper presents in detail the step-wise approach we followed and the mechanisms implemented. A case study in the field of medical informatics illustrates how the ontology engineering phases have been adapted for optimal integration with the UMLS. We provide qualitative and quantitative results, which indicate the validity and usefulness of our methodology. Published by Elsevier Inc.

Analyzing the scale of the bainitic ferrite plates by XRD, SEM and TEM

International Nuclear Information System (INIS)

Garcia-Mateo, Carlos; Jimenez, Jose A.; Lopez-Ezquerra, Belen; Rementeria, Rosalia; Morales-Rivas, Lucia; Kuntz, Matthias; Caballero, Francisca G.

2016-01-01

Since the major strengthening mechanisms in nanocrystalline bainitic steels arise from the exceptionally small size of the bainitc ferrite plate, accurate determination of this parameter is fundamental for quantitative relating the microstructure to the mechanical properties. In this work, the thickness of the bainitic ferrite subunits obtained by different bainitic heat treatments was determined in two steels, with carbon contents of 0.3 and 0.7 wt.%, from SEM and TEM micrographs. As these measurements were made on 2D images taken from random sections, the method includes some stereological correction factors to obtain accurate information. Finally, the determined thicknesses of bainitic ferrite plates were compared with the crystallite size calculated from the analysis of X-ray diffraction peak broadening. Although in some case the values obtained for crystallite size and plate thickness can be similar, this study confirms that indeed they are two different parameters. - Highlights: •Bainitic microstructure in a nanostructured and sub-micron steel •Bainitic ferrite plate thickness measured by SEM and TEM •Crystallite size determined by X-ray analysis

Analyzing the scale of the bainitic ferrite plates by XRD, SEM and TEM

Energy Technology Data Exchange (ETDEWEB)

Garcia-Mateo, Carlos, E-mail: cgm@cenim.csic.es [Department of Physical Metallurgy, Spanish National Center for Metallurgical Research (CENIM-CSIC), Avda. Gregorio del Amo 8, E-28040 Madrid (Spain); Jimenez, Jose A.; Lopez-Ezquerra, Belen; Rementeria, Rosalia; Morales-Rivas, Lucia [Department of Physical Metallurgy, Spanish National Center for Metallurgical Research (CENIM-CSIC), Avda. Gregorio del Amo 8, E-28040 Madrid (Spain); Kuntz, Matthias [Robert-Bosch GmbH, Materials and Process Engineering Metals, Renningen, 70465 Stuttgart (Germany); Caballero, Francisca G. [Department of Physical Metallurgy, Spanish National Center for Metallurgical Research (CENIM-CSIC), Avda. Gregorio del Amo 8, E-28040 Madrid (Spain)

2016-12-15

Since the major strengthening mechanisms in nanocrystalline bainitic steels arise from the exceptionally small size of the bainitc ferrite plate, accurate determination of this parameter is fundamental for quantitative relating the microstructure to the mechanical properties. In this work, the thickness of the bainitic ferrite subunits obtained by different bainitic heat treatments was determined in two steels, with carbon contents of 0.3 and 0.7 wt.%, from SEM and TEM micrographs. As these measurements were made on 2D images taken from random sections, the method includes some stereological correction factors to obtain accurate information. Finally, the determined thicknesses of bainitic ferrite plates were compared with the crystallite size calculated from the analysis of X-ray diffraction peak broadening. Although in some case the values obtained for crystallite size and plate thickness can be similar, this study confirms that indeed they are two different parameters. - Highlights: •Bainitic microstructure in a nanostructured and sub-micron steel •Bainitic ferrite plate thickness measured by SEM and TEM •Crystallite size determined by X-ray analysis.

Dark-field image contrast in transmission scanning electron microscopy: Effects of substrate thickness and detector collection angle

Energy Technology Data Exchange (ETDEWEB)

Woehl, Taylor, E-mail: tjwoehl@umd.edu; Keller, Robert

2016-12-15

An annular dark field (ADF) detector was placed beneath a specimen in a field emission scanning electron microscope operated at 30 kV to calibrate detector response to incident beam current, and to create transmission images of gold nanoparticles on silicon nitride (SiN) substrates of various thicknesses. Based on the linear response of the ADF detector diodes to beam current, we developed a method that allowed for direct determination of the percentage of that beam current forward scattered to the ADF detector from the sample, i.e. the transmitted electron (TE) yield. Collection angles for the ADF detector region were defined using a masking aperture above the detector and were systematically varied by changing the sample to detector distance. We found the contrast of the nanoparticles, relative to the SiN substrate, decreased monotonically with decreasing inner exclusion angle and increasing substrate thickness. We also performed Monte Carlo electron scattering simulations, which showed quantitative agreement with experimental contrast associated with the nanoparticles. Together, the experiments and Monte Carlo simulations revealed that the decrease in contrast with decreasing inner exclusion angle was due to a rapid increase in the TE yield of the low atomic number substrate. Nanoparticles imaged at low inner exclusion angles (<150 mrad) and on thick substrates (>50 nm) showed low image contrast in their centers surrounded by a bright high-contrast halo on their edges. This complex image contrast was predicted by Monte Carlo simulations, which we interpreted in terms of mixing of the nominally bright field (BF) and ADF electron signals. Our systematic investigation of inner exclusion angle and substrate thickness effects on ADF t-SEM imaging provides fundamental understanding of the contrast mechanisms for image formation, which in turn suggest practical limitations and optimal imaging conditions for different substrate thicknesses. - Highlights: • Developed a

Live cell imaging reveals marked variability in myoblast proliferation and fate

Science.gov (United States)

2013-01-01

Background During the process of muscle regeneration, activated stem cells termed satellite cells proliferate, and then differentiate to form new myofibers that restore the injured area. Yet not all satellite cells contribute to muscle repair. Some continue to proliferate, others die, and others become quiescent and are available for regeneration following subsequent injury. The mechanisms that regulate the adoption of different cell fates in a muscle cell precursor population remain unclear. Methods We have used live cell imaging and lineage tracing to study cell fate in the C2 myoblast line. Results Analyzing the behavior of individual myoblasts revealed marked variability in both cell cycle duration and viability, but similarities between cells derived from the same parental lineage. As a consequence, lineage sizes and outcomes differed dramatically, and individual lineages made uneven contributions toward the terminally differentiated population. Thus, the cohort of myoblasts undergoing differentiation at the end of an experiment differed dramatically from the lineages present at the beginning. Treatment with IGF-I increased myoblast number by maintaining viability and by stimulating a fraction of cells to complete one additional cell cycle in differentiation medium, and as a consequence reduced the variability of the terminal population compared with controls. Conclusion Our results reveal that heterogeneity of responses to external cues is an intrinsic property of cultured myoblasts that may be explained in part by parental lineage, and demonstrate the power of live cell imaging for understanding how muscle differentiation is regulated. PMID:23638706

Pseudo Prune Belly Syndrome: Diagnosis Revealed by Imaging – A Case Report and Brief Review

Science.gov (United States)

Grover, Hemal; Sethi, Sanjay; Garg, Jatin; Ahluwalia, Amrit Pal

2017-01-01

Summary Background Prune Belly Syndrome (PBS) is a rare entity, usually found in male neonates. It comprises complex urinary tract anomalies, bilateral undescended testis and absence of anterior abdominal wall muscles. Patients with unilateral abdominal wall deficiency, unilateral undescended testis and female neonates with abdominal wall laxity are classified as Pseudo Prune Belly syndrome (PPBS). Reports on PPBS do not highlight the radiological and imaging characteristics of this syndrome and the current literature on the role of newer imaging modalities, such as Magnetic Resonance Imaging (MRI), remains relatively sparse. We describe a new case of PPBS and emphasize the role of imaging, especially ultrasound and MRI in the process of diagnosis and briefly review the subject. Case Report A male infant of four months of age was referred for evaluation of left-sided cryptorchidism. Clinical examination revealed laxity of the left abdominal wall. Ultrasound examination of the abdomen, pelvis and scrotum was performed together with routine laboratory tests. Ultrasound examination was followed by intravenous urography, voiding cysto-urethrography and MRI of the abdomen. On ultrasound, the left testis was located in the inguinal canal, the right kidney was slightly enlarged and the left kidney could not be localized. Ultrasound appearances suggested chronic obstruction in the urinary bladder. Intravenous urography, voiding cysto-urethrography and MRI confirmed the ultrasound diagnosis and also revealed a left dysplastic kidney with a dilated, tortuous ureter. Clinical and imaging features were consistent with pseudo prune belly syndrome (PPBS). Conclusions We report a new occurrence of PPBS, a rare entity. The imaging approach for a comprehensive evaluation of the renal system in PPBS, especially with MRI, is emphasized. PMID:28580040

semPLS: Structural Equation Modeling Using Partial Least Squares

Directory of Open Access Journals (Sweden)

Armin Monecke

2012-05-01

Full Text Available Structural equation models (SEM are very popular in many disciplines. The partial least squares (PLS approach to SEM offers an alternative to covariance-based SEM, which is especially suited for situations when data is not normally distributed. PLS path modelling is referred to as soft-modeling-technique with minimum demands regarding mea- surement scales, sample sizes and residual distributions. The semPLS package provides the capability to estimate PLS path models within the R programming environment. Different setups for the estimation of factor scores can be used. Furthermore it contains modular methods for computation of bootstrap confidence intervals, model parameters and several quality indices. Various plot functions help to evaluate the model. The well known mobile phone dataset from marketing research is used to demonstrate the features of the package.

USE OF DIFFUSION-WEIGHTED MAGNETIC RESONANCE IMAGING FOR REVEALING HYPOXIC-ISCHEMIC BRAIN LESIONS IN NEONATES

Directory of Open Access Journals (Sweden)

E. V. Shimchenko

2014-01-01

Full Text Available The article presents advantages of use of diffusion-weighted magnetic resonance imaging (DW MRI for revealing hypoxic-ischemic brain lesions in neonates. The trial included 97 neonates with perinatal brain lesion who had been undergoing treatment at a resuscitation department or neonatal pathology department in the first month of life. The article shows high information value of diffusion-weighted images (DWI for diagnostics of hypoxic-ischemic lesions in comparison with regular standard modes. In the event of no structural brain lesions of neonates, pronounced increase in signal characteristics revealed by DWI indicated considerable pathophysiological alterations. Subsequently, children developed structural alterations in the form of cystic encephalomalacia with expansion of cerebrospinal fluid spaces manifested with pronounced neurological deficit. DW MRI has been offered as a method of prognosticating further neurological development of children on early stages. 

Detailed SEM-EPMA investigation of high specific radioactivity particles (hot particles)

International Nuclear Information System (INIS)

Burin, K.; Tsacheva, Ts.; Mandjoukov, I.; Mandjoukova, B.

1993-01-01

Scanning electron microscope (SEM) images and electron probe microanalysis (EPMA) spectra of a group of hot particles collected in Bulgaria after the Chernobyl accident have been obtained. A technique for hot particle localization is described. The object is irradiated for two days with a β source and the resulting autoradiographs show particles location precisely. High resolution x-ray spectrum of each particle has been obtained using EPMA. The distribution of chemical elements is visualized by colour dot maps representing the regions of interest of the spectrum. It is concluded that apart from reactor fuel the investigated hot particles come from either construction materials or materials used for the covering of the damaged reactor. 7 figs., 2 ref

Recent Optical and SEM Characterization of Genesis Solar Wind Concentrator Diamond on Silicon Collector

Science.gov (United States)

Allton, Judith H.; Rodriquez, M. C.; Burkett, P. J.; Ross, D. K.; Gonzalez, C. P.; McNamara, K. M.

2013-01-01

One of the 4 Genesis solar wind concentrator collectors was a silicon substrate coated with diamond-like carbon (DLC) in which to capture solar wind. This material was designed for analysis of solar nitrogen and noble gases [1, 2]. This particular collector fractured during landing, but about 80% of the surface was recovered, including a large piece which was subdivided in 2012 [3, 4, 5]. The optical and SEM imaging and analysis described below supports the subdivision and allocation of the diamond-on-silicon (DOS) concentrator collector.

SEM microcharacterization of semiconductors

CERN Document Server

Holt, D B

1989-01-01

Applications of SEM techniques of microcharacterization have proliferated to cover every type of material and virtually every branch of science and technology. This book emphasizes the fundamental physical principles. The first section deals with the foundation of microcharacterization in electron beam instruments and the second deals with the interpretation of the information obtained in the main operating modes of a scanning electron microscope.

Reconstructing the microstructure of polyimide-silicalite mixed-matrix membranes and their particle connectivity using FIB-SEM tomography.

Science.gov (United States)

Diblíková, P; Veselý, M; Sysel, P; Čapek, P

2018-03-01

Properties of a composite material made of a continuous matrix and particles often depend on microscopic details, such as contacts between particles. Focusing on processing raw focused-ion beam scanning electron microscope (FIB-SEM) tomography data, we reconstructed three mixed-matrix membrane samples made of 6FDA-ODA polyimide and silicalite-1 particles. In the first step of image processing, backscattered electron (BSE) and secondary electron (SE) signals were mixed in a ratio that was expected to obtain a segmented 3D image with a realistic volume fraction of silicalite-1. Second, after spatial alignment of the stacked FIB-SEM data, the 3D image was smoothed using adaptive median and anisotropic nonlinear diffusion filters. Third, the image was segmented using the power watershed method coupled with a seeding algorithm based on geodesic reconstruction from the markers. If the resulting volume fraction did not match the target value quantified by chemical analysis of the sample, the BSE and SE signals were mixed in another ratio and the procedure was repeated until the target volume fraction was achieved. Otherwise, the segmented 3D image (replica) was accepted and its microstructure was thoroughly characterized with special attention paid to connectivity of the silicalite phase. In terms of the phase connectivity, Monte Carlo simulations based on the pure-phase permeability values enabled us to calculate the effective permeability tensor, the main diagonal elements of which were compared with the experimental permeability. In line with the hypothesis proposed in our recent paper (Čapek, P. et al. (2014) Comput. Mater. Sci. 89, 142-156), the results confirmed that the existence of particle clusters was a key microstructural feature determining effective permeability. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

An electron moiré method for a common SEM

Institute of Scientific and Technical Information of China (English)

Y.M.Xing; S.Kishimoto; Y.R.Zhao

2006-01-01

In the electron moiré method,a high-frequency grating is used to measure microscopic deformation,which promises significant potential applications for the method in the microscopic analysis of materials.However,a special beam scanning control device is required to produce a grating and generate a moiré fringe pattern for the scanning electron microscope (SEM).Because only a few SEMs used in the material science studies are equipped with this device,the use of the electron moiré method is limited.In this study,an electron moiré method for a common SEM without the beam control device is presented.A grating based on a multi-scanning concept is fabricated in any observing mode.A real-time moiré pattern can also be generated in the SEM or an optical filtering system.Without the beam control device being a prerequisite,the electron moiré method can be more widely used.The experimental results from three different types of SEMS show that high quality gratings with uniform lines and less pitch error can be fabricated by this method,and moiré patterns can also be correctly generated.

SEM facility for examination of reactive and radioactive materials

International Nuclear Information System (INIS)

Downs, G.L.; Tucker, P.A.

1977-01-01

A scanning electron microscope (SEM) facility for the examination of tritium-containing materials is operational at Mound Laboratory. The SEM is installed with the sample chamber incorporated as an integral part of an inert gas glovebox facility to enable easy handling of radioactive and pyrophoric materials. A standard SEM (ETEC Model B-1) was modified to meet dimensional, operational, and safety-related requirements. a glovebox was designed and fabricated which permitted access with the gloves to all parts of the SEM sample chamber to facilitate director and accessory replacement and repairs. A separate console combining the electron optical column and specimen chamber was interfaced to the glovebox by a custom-made, neoprene bellows so that the vibrations normally associated with the blowers and pumps were damped. Photomicrographs of tritiated pyrophoric materials show the usefulness of this facility. Some of the difficulties involved in the investigation of these materials are also discussed. The SEM is also equipped with an energy dispersive x-ray detector (ORTEC) and a Secondary Ion Mass Spectrometer (3M) attachments. This latter attachment allows analysis of secondary ions with masses ranging from 1-300 amu. (Auth.)

Transport Imaging in the One Dimensional Limit

National Research Council Canada - National Science Library

Winchell, Stephen D

2006-01-01

Transport imaging is a SEM-based technique used to directly image the motion and recombination of charge in luminescent semiconductors, allowing for the extraction of transport parameters critical to device operation...

New insights into morphological features of Hadjelia truncata (Spirurida: Habronematidae), as revealed by SEM.

Science.gov (United States)

Naem, Soraya; Houston, Robin S; Sentíes-Cué, Gabriel

2013-01-01

Hadjelia truncata (Spirurida: Habronematidae) is a nematode found in the gizzard of several avian species. However, it has been reported pathogenic only in pigeons (Columba livia), in which it causes severe ventriculitis. Scanning electron microscopy (SEM) was used to study the morphological aspects of adult worms of this nematode in detail. Males and females measured 6.5-9 and 12-16.5 mm, respectively. The bodies were straight with moderate uniform thickness in both males and females, narrowing at the anterior end. The cuticle was striated transversely. The mouth was surrounded by two lateral trilobed lips, and the dorsal and ventral interlabia were present. The two cephalic papillae were present on each side lodged just behind the upper and lower bases of each lip. Around the mouth, a large amphid was seen on each lip. At the anterior end of both male and female worms, an excretory pore on the ventral side and a pair of lateral cervical papillae were observed. In the female, the vulva was located at the anterior end of the body. The lips of the vulva protruded above the body surface, and the bluntly rounded posterior end showed an anal pore and two subterminal phasmids. The posterior end of the males curved ventrally, with large caudal alae supported by four pairs of stalked precloacal papillae, a single medial precloacal papilla, two pairs of postcloacal papillae, and a cluster of small papillae on the caudal extremity. Spicules were unequal and dissimilar.

Structure and surface morphology studies of cerium oxide system using XRD and SEM analysis

International Nuclear Information System (INIS)

Ahmad Jais Alimin; Farid Nasir Ani; Wan Azelee Wan Abu Bakar

2000-01-01

Conventional Precious Group Materials (PGM) catalyst systems have been using CeO 2 as an Oxygen Storage Capacity component in the catalyst washcoat. Due to the limitations of the PGM catalyst, researches are now focusing on improving or replacing this conventional system. In a previous work, the potential of a copper-ceria (Cu-Ce) oxide as a catalyst system has been identified. In this paper, the morphology and characterisation of Cu-Ce oxides analysed using XRD and SEM will be described. The Cu-Ce samples were prepared at a fixed ratio under temperatures of 400 o C and 800 o C. XRD diffractograms showed CeO 2 is in a cubic phase at 400 o C and 800 o C. At 800 o C, the CuO particle is visible, presumably has incorporated with the lattice structure of ceria, indicating an absent of solid state condition between copper and ceria. Analysis by SEM revealed significant increase in particle sizes with increasing calcination temperatures. (Author)

Toward an implicit measure of emotions: ratings of abstract images reveal distinct emotional states.

Science.gov (United States)

Bartoszek, Gregory; Cervone, Daniel

2017-11-01

Although implicit tests of positive and negative affect exist, implicit measures of distinct emotional states are scarce. Three experiments examined whether a novel implicit emotion-assessment task, the rating of emotion expressed in abstract images, would reveal distinct emotional states. In Experiment 1, participants exposed to a sadness-inducing story inferred more sadness, and less happiness, in abstract images. In Experiment 2, an anger-provoking interaction increased anger ratings. In Experiment 3, compared to neutral images, spider images increased fear ratings in spider-fearful participants but not in controls. In each experiment, the implicit task indicated elevated levels of the target emotion and did not indicate elevated levels of non-target negative emotions; the task thus differentiated among emotional states of the same valence. Correlations also supported the convergent and discriminant validity of the implicit task. Supporting the possibility that heuristic processes underlie the ratings, group differences were stronger among those who responded relatively quickly.

A ‘NanoSuit’ surface shield successfully protects organisms in high vacuum: observations on living organisms in an FE-SEM

Science.gov (United States)

Takaku, Yasuharu; Suzuki, Hiroshi; Ohta, Isao; Tsutsui, Takami; Matsumoto, Haruko; Shimomura, Masatsugu; Hariyama, Takahiko

2015-01-01

Although extremely useful for a wide range of investigations, the field emission scanning electron microscope (FE-SEM) has not allowed researchers to observe living organisms. However, we have recently reported that a simple surface modification consisting of a thin extra layer, termed ‘NanoSuit’, can keep organisms alive in the high vacuum (10−5 to 10−7 Pa) of the SEM. This paper further explores the protective properties of the NanoSuit surface-shield. We found that a NanoSuit formed with the optimum concentration of Tween 20 faithfully preserves the integrity of an organism's surface without interfering with SEM imaging. We also found that electrostatic charging was absent as long as the organisms were alive, even if they had not been coated with electrically conducting materials. This result suggests that living organisms possess their own electrical conductors and/or rely on certain properties of the surface to inhibit charging. The NanoSuit seems to prolong the charge-free condition and increase survival time under vacuum. These findings should encourage the development of more sophisticated observation methods for studying living organisms in an FE-SEM. PMID:25631998

On the importance of FIB-SEM specific segmentation algorithms for porous media

Energy Technology Data Exchange (ETDEWEB)

Salzer, Martin, E-mail: martin.salzer@uni-ulm.de [Institute of Stochastics, Faculty of Mathematics and Economics, Ulm University, D-89069 Ulm (Germany); Thiele, Simon, E-mail: simon.thiele@imtek.uni-freiburg.de [Laboratory for MEMS Applications, IMTEK, Department of Microsystems Engineering, University of Freiburg, D-79110 Freiburg (Germany); Zengerle, Roland, E-mail: zengerle@imtek.uni-freiburg.de [Laboratory for MEMS Applications, IMTEK, Department of Microsystems Engineering, University of Freiburg, D-79110 Freiburg (Germany); Schmidt, Volker, E-mail: volker.schmidt@uni-ulm.de [Institute of Stochastics, Faculty of Mathematics and Economics, Ulm University, D-89069 Ulm (Germany)

2014-09-15

A new algorithmic approach to segmentation of highly porous three dimensional image data gained by focused ion beam tomography is described which extends the key-principle of local threshold backpropagation described in Salzer et al. (2012). The technique of focused ion beam tomography has shown to be capable of imaging the microstructure of functional materials. In order to perform a quantitative analysis on the corresponding microstructure a segmentation task needs to be performed. However, algorithmic segmentation of images obtained with focused ion beam tomography is a challenging problem for highly porous materials if filling the pore phase, e.g. with epoxy resin, is difficult. The gray intensities of individual voxels are not sufficient to determine the phase represented by them and usual thresholding methods are not applicable. We thus propose a new approach to segmentation that pays respect to the specifics of the imaging process of focused ion beam tomography. As an application of our approach, the segmentation of three dimensional images for a cathode material used in polymer electrolyte membrane fuel cells is discussed. We show that our approach preserves significantly more of the original nanostructure than a thresholding approach. - Highlights: • We describe a new approach to the segmentation of FIB-SEM images of porous media. • The first and last occurrences of structures are detected by analysing the z-profiles. • The algorithm is validated by comparing it to a manual segmentation. • The new approach shows significantly less artifacts than a thresholding approach. • A structural analysis also shows improved results for the obtained microstructure.

Design and Use of the Simple Event Model (SEM)

NARCIS (Netherlands)

van Hage, W.R.; Malaisé, V.; Segers, R.H.; Hollink, L.

2011-01-01

Events have become central elements in the representation of data from domains such as history, cultural heritage, multimedia and geography. The Simple Event Model (SEM) is created to model events in these various domains, without making assumptions about the domain-specific vocabularies used. SEM

The Antiphagocytic Activity of SeM of Streptococcus equi Requires Capsule.

Science.gov (United States)

Timoney, John F; Suther, Pranav; Velineni, Sridhar; Artiushin, Sergey C

2014-01-01

Resistance to phagocytosis is a crucial virulence property of Streptococcus equi (Streptococcus equi subsp. equi; Se), the cause of equine strangles. The contribution and interdependence of capsule and SeM to killing in equine blood and neutrophils were investigated in naturally occurring strains of Se. Strains CF32, SF463 were capsule and SeM positive, strains Lex90, Lex93 were capsule negative and SeM positive and strains Se19, Se1-8 were capsule positive and SeM deficient. Phagocytosis and killing of Se19, Se1-8, Lex90 and Lex93 in equine blood and by neutrophils suspended in serum were significantly (P ≤ 0.02) greater compared to CF32 and SF463. The results indicate capsule and SeM are both required for resistance to phagocytosis and killing and that the anti-phagocytic property of SeM is greatly reduced in the absence of capsule.

Improvement of geometrical measurements from 3D-SEM reconstructions

DEFF Research Database (Denmark)

Carli, Lorenzo; De Chiffre, Leonardo; Horsewell, Andy

2009-01-01

The quantification of 3D geometry at the nanometric scale is a major metrological challenge. In this work geometrical measurements on cylindrical items obtained with a 3D-SEM were investigated. Two items were measured: a wire gauge having a 0.25 mm nominal diameter and a hypodermic needle having...... that the diameter estimation performed using the 3D-SEM leads to an overestimation of approx. 7% compared to the reference values obtained using a 1-D length measuring machine. Standard deviation of SEM measurements performed on the wire gauge is approx. 1.5 times lower than the one performed on the hypodermic...

Canticum Novum: música sem palavras e palavras sem som no pensamento de Santo Agostinho

Directory of Open Access Journals (Sweden)

Lorenzo Mammì

2000-04-01

Full Text Available NO De Magistro, Santo Agostinho coloca a reza e o canto numa posição similar, à margem das funções imediatamente comunicativas da linguagem. A reflexão agostiniana sobre a reza se baseia nos hábitos cristãos da leitura, da oração e da meditação silenciosas. Há sobre o canto, na prática igualmente inovadora do jubilus, melodia sem palavra destinada aos momentos mais intensos e gaudiosos da liturgia. A oração silenciosa e o jubilus são temas recorrentes da literatura patrística, mas Agostinho os aborda de maneira original, desenhando, a partir das palavras sem som da oração e do som sem palavra do jubilus, o perfil de um discurso interior, que não se destina aos homens, mas a Deus.IN HIS De Magistro Saint Augustine places prayer and song on a similar level, alongside the language immediately communicative functions. His considerations on prayer are grounded on the Christian habits of silent reading, prayer and meditation; those on song, on the equally innovating practice called jubilus, which is melody without words designed for the intensest and most joyous liturgical moments. Silent prayer and jubilus are recurring topics in patristic literature, but Augustine deals with them in an original way, drawing from the soundless words of prayer and the wordless sound of jubilus an inner discourse, addressed not to men but to God.

Tablet surface characterisation by various imaging techniques

DEFF Research Database (Denmark)

Seitavuopio, Paulus; Rantanen, Jukka; Yliruusi, Jouko

2003-01-01

The aim of this study was to characterise tablet surfaces using different imaging and roughness analytical techniques including optical microscopy, scanning electron microscopy (SEM), laser profilometry and atomic force microscopy (AFM). The test materials compressed were potassium chloride (KCl......) and sodium chloride (NaCl). It was found that all methods used suggested that the KCl tablets were smoother than the NaCl tablets and higher compression pressure made the tablets smoother. Imaging methods like optical microscopy and SEM can give useful information about the roughness of the sample surface...

Multiple-Group Analysis Using the sem Package in the R System

Science.gov (United States)

Evermann, Joerg

2010-01-01

Multiple-group analysis in covariance-based structural equation modeling (SEM) is an important technique to ensure the invariance of latent construct measurements and the validity of theoretical models across different subpopulations. However, not all SEM software packages provide multiple-group analysis capabilities. The sem package for the R…

SEM technique for experimentally locating latch-up paths in integrated circuits

International Nuclear Information System (INIS)

Dressendorfer, P.V.; Armendariz, M.G.

1980-01-01

A technique is presented for using the scanning electron microscope (SEM) in the electron-beam-induced current (EBIC) mode to delineate latch-up paths in CMOS ICs. In the EBIC mode, the current produced by the collection and separation of the electron-beam-generated electron-hole pairs in the space charge regions of the device is measured and used to form an image. Since the collection of these carriers is dependent on space charge region width (and thus junction potential), anything that alters the depletion layer width will affect the collection efficiency. In a latch condition the junctions involved in the latch will be biased differently from those which are not, and thus the EBIC signal from those regions should be measurably different

SEM: A Cultural Change Agent

Science.gov (United States)

Barnes, Bradley; Bourke, Brian

2015-01-01

The authors advance the concept that institutional culture is a purposeful framework by which to view SEM's utility, particularly as a cultural change agent. Through the connection of seemingly independent functions of performance and behavior, implications emerge that deepen the understanding of the influence of culture on performance outcomes…

On the Nature of SEM Estimates of ARMA Parameters.

Science.gov (United States)

Hamaker, Ellen L.; Dolan, Conor V.; Molenaar, Peter C. M.

2002-01-01

Reexamined the nature of structural equation modeling (SEM) estimates of autoregressive moving average (ARMA) models, replicated the simulation experiments of P. Molenaar, and examined the behavior of the log-likelihood ratio test. Simulation studies indicate that estimates of ARMA parameters observed with SEM software are identical to those…

Sobre la estructura semántica de las palabras autosemánticas

Directory of Open Access Journals (Sweden)

Morales Ascencio Bernardo

1993-06-01

Full Text Available

A partir de los conceptos de semema o estructura semémica y de los conceptos tradicionales de afijos y los accidentes gramaticales se plantea una supuesta estructura semántica profunda de la palabra, análoga a la de la oración en el modelo de la gramática de casos. Con base en este supuesto se reinterpretan algunas funciones semánticas de los afijos (particularmente de los sufijos, entre otras, como formas de la expresión de la modalidad léxica; se plantea una correlación entre rasgos semánticos específicos y las relaciones semánticas de caso. Por último se deducen algunas consideraciones pertinentes y se demuestra un isomorfismo entre la estructura profunda de la oración y la supuesta estructura semántica profunda de las palabras auto  semánticas.

Protective effects of a zinc-hydroxyapatite toothpaste on enamel erosion: SEM study.

Science.gov (United States)

Colombo, Marco; Beltrami, Riccardo; Rattalino, Davide; Mirando, Maria; Chiesa, Marco; Poggio, Claudio

2016-01-01

The aim of the present in vitro study was to evaluate the protective effects of a zinc-hydroxyapatite toothpaste against an erosive challenge produced by a soft drink (Coca-Cola) using Scanning Electron Microscopy (SEM). Forty specimens were assigned to 4 groups of 10 specimens each (group 1: no erosive challenge, no toothpaste treatment, group 2: erosive challenge, no toothpaste treatment, group 3: erosive challenge, fluoride toothpaste treatment, group 4: erosive challenge, zinc-hydroxyapatite toothpaste treatment). The surface of each specimen was imaged by SEM. A visual rating system was used to evaluate the condition of the enamel surface; results were analyzed by nonparametric statistical methods. Statistically significant differences were found between the samples untreated and those immersed in Coca-Cola (group 1, 2); the highest grade of damage was found in group 2, while the lowest grade was recorded in the samples of group 4. Comparing the groups, the two analyzed toothpaste tended to protect in different extend. In this study treatment of erosively challenged enamel with Zn-Hap toothpaste showed a clear protective effect. This was greater than the effect observed for a normal fluoride toothpaste and confirmed the potential benefit the Zn-HAP technology can provide in protecting enamel from erosive acid challenges.

Real-time in vivo imaging of butterfly wing development: revealing the cellular dynamics of the pupal wing tissue.

Directory of Open Access Journals (Sweden)

Masaki Iwata

Full Text Available Butterfly wings are covered with regularly arranged single-colored scales that are formed at the pupal stage. Understanding pupal wing development is therefore crucial to understand wing color pattern formation. Here, we successfully employed real-time in vivo imaging techniques to observe pupal hindwing development over time in the blue pansy butterfly, Junonia orithya. A transparent sheet of epithelial cells that were not yet regularly arranged was observed immediately after pupation. Bright-field imaging and autofluorescent imaging revealed free-moving hemocytes and tracheal branches of a crinoid-like structure underneath the epithelium. The wing tissue gradually became gray-white, epithelial cells were arranged regularly, and hemocytes disappeared, except in the bordering lacuna, after which scales grew. The dynamics of the epithelial cells and scale growth were also confirmed by fluorescent imaging. Fluorescent in vivo staining further revealed that these cells harbored many mitochondria at the surface of the epithelium. Organizing centers for the border symmetry system were apparent immediately after pupation, exhibiting a relatively dark optical character following treatment with fluorescent dyes, as well as in autofluorescent images. The wing tissue exhibited slow and low-frequency contraction pulses with a cycle of approximately 10 to 20 minutes, mainly occurring at 2 to 3 days postpupation. The pulses gradually became slower and weaker and eventually stopped. The wing tissue area became larger after contraction, which also coincided with an increase in the autofluorescence intensity that might have been caused by scale growth. Examination of the pattern of color development revealed that the black pigment was first deposited in patches in the central areas of an eyespot black ring and a parafocal element. These results of live in vivo imaging that covered wide wing area for a long time can serve as a foundation for studying the

Real-time in vivo imaging of butterfly wing development: revealing the cellular dynamics of the pupal wing tissue.

Science.gov (United States)

Iwata, Masaki; Ohno, Yoshikazu; Otaki, Joji M

2014-01-01

Butterfly wings are covered with regularly arranged single-colored scales that are formed at the pupal stage. Understanding pupal wing development is therefore crucial to understand wing color pattern formation. Here, we successfully employed real-time in vivo imaging techniques to observe pupal hindwing development over time in the blue pansy butterfly, Junonia orithya. A transparent sheet of epithelial cells that were not yet regularly arranged was observed immediately after pupation. Bright-field imaging and autofluorescent imaging revealed free-moving hemocytes and tracheal branches of a crinoid-like structure underneath the epithelium. The wing tissue gradually became gray-white, epithelial cells were arranged regularly, and hemocytes disappeared, except in the bordering lacuna, after which scales grew. The dynamics of the epithelial cells and scale growth were also confirmed by fluorescent imaging. Fluorescent in vivo staining further revealed that these cells harbored many mitochondria at the surface of the epithelium. Organizing centers for the border symmetry system were apparent immediately after pupation, exhibiting a relatively dark optical character following treatment with fluorescent dyes, as well as in autofluorescent images. The wing tissue exhibited slow and low-frequency contraction pulses with a cycle of approximately 10 to 20 minutes, mainly occurring at 2 to 3 days postpupation. The pulses gradually became slower and weaker and eventually stopped. The wing tissue area became larger after contraction, which also coincided with an increase in the autofluorescence intensity that might have been caused by scale growth. Examination of the pattern of color development revealed that the black pigment was first deposited in patches in the central areas of an eyespot black ring and a parafocal element. These results of live in vivo imaging that covered wide wing area for a long time can serve as a foundation for studying the cellular dynamics of living

Description and calibration beamline SEM/Ion Chamber Current Digitizer

International Nuclear Information System (INIS)

Schoo, D.

1994-05-01

This report discusses the following on beamline SEM/ion chamber current digitizers: Module description; testing and calibration; common setup procedures; summary of fault indications and associated causes; summary of input and output connections; SEM conversion constant table; ion chamber conversion constant table; hexadecimal to decimal conversion table; and schematic diagram

Labyrinths, columns and cavities: new internal features of pollen grain walls in the Acanthaceae detected by FIB-SEM.

Science.gov (United States)

House, Alisoun; Balkwill, Kevin

2016-03-01

External pollen grain morphology has been widely used in the taxonomy and systematics of flowering plants, especially the Acanthaceae which are noted for pollen diversity. However internal pollen wall features have received far less attention due to the difficulty of examining the wall structure. Advancing technology in the field of microscopy has made it possible, with the use of a focused ion beam-scanning electron microscope (FIB-SEM), to view the structure of pollen grain walls in far greater detail and in three dimensions. In this study the wall structures of 13 species from the Acanthaceae were investigated for features of potential systematic relevance. FIB-SEM was applied to obtain precise cross sections of pollen grains at selected positions for examining the wall ultrastructure. Exploratory studies of the exine have thus far identified five basic structural types. The investigations also show that similar external pollen wall features may have a distinctly different internal structure. FIB-SEM studies have revealed diverse internal pollen wall features which may now be investigated for their systematic and functional significance.

Imaging of surface spin textures on bulk crystals by scanning electron microscopy

Science.gov (United States)

Akamine, Hiroshi; Okumura, So; Farjami, Sahar; Murakami, Yasukazu; Nishida, Minoru

2016-11-01

Direct observation of magnetic microstructures is vital for advancing spintronics and other technologies. Here we report a method for imaging surface domain structures on bulk samples by scanning electron microscopy (SEM). Complex magnetic domains, referred to as the maze state in CoPt/FePt alloys, were observed at a spatial resolution of less than 100 nm by using an in-lens annular detector. The method allows for imaging almost all the domain walls in the mazy structure, whereas the visualisation of the domain walls with the classical SEM method was limited. Our method provides a simple way to analyse surface domain structures in the bulk state that can be used in combination with SEM functions such as orientation or composition analysis. Thus, the method extends applications of SEM-based magnetic imaging, and is promising for resolving various problems at the forefront of fields including physics, magnetics, materials science, engineering, and chemistry.

SEM-668-G2（日东科技）

Institute of Scientific and Technical Information of China (English)

无

2005-01-01

SEM-668-G2比SEM-668在视觉技术上更加精湛，采用美国AGILENT（安提伦）LASER 5519A及HP的双重频率技术，加强运动；隹确性。在智能化印刷头上，SEM-668-G2印刷质量更加均匀、稳定，操作界面更加简易、更加人性化。在综合性能上更加卓越，保证实现现代化的生产效率。产品体具性能如下：SEM-668-G2视觉全自动印刷机

Automated SEM Modal Analysis Applied to the Diogenites

Science.gov (United States)

Bowman, L. E.; Spilde, M. N.; Papike, James J.

1996-01-01

Analysis of volume proportions of minerals, or modal analysis, is routinely accomplished by point counting on an optical microscope, but the process, particularly on brecciated samples such as the diogenite meteorites, is tedious and prone to error by misidentification of very small fragments, which may make up a significant volume of the sample. Precise volume percentage data can be gathered on a scanning electron microscope (SEM) utilizing digital imaging and an energy dispersive spectrometer (EDS). This form of automated phase analysis reduces error, and at the same time provides more information than could be gathered using simple point counting alone, such as particle morphology statistics and chemical analyses. We have previously studied major, minor, and trace-element chemistry of orthopyroxene from a suite of diogenites. This abstract describes the method applied to determine the modes on this same suite of meteorites and the results of that research. The modal abundances thus determined add additional information on the petrogenesis of the diogenites. In addition, low-abundance phases such as spinels were located for further analysis by this method.

The C. elegans Spalt-like protein SEM-4 functions through the SoxC transcription factor SEM-2 to promote a proliferative blast cell fate in the postembryonic mesoderm.

Science.gov (United States)

Shen, Qinfang; Shi, Herong; Tian, Chenxi; Ghai, Vikas; Liu, Jun

2017-09-01

Proper development of a multicellular organism relies on well-coordinated regulation of cell fate specification, cell proliferation and cell differentiation. The C. elegans postembryonic mesoderm provides a useful system for uncovering factors involved in these processes and for further dissecting their regulatory relationships. The single Spalt-like zinc finger containing protein SEM-4/SALL is known to be involved in specifying the proliferative sex myoblast (SM) fate. We have found that SEM-4/SALL is sufficient to promote the SM fate and that it does so in a cell autonomous manner. We further showed that SEM-4/SALL acts through the SoxC transcription factor SEM-2 to promote the SM fate. SEM-2 is known to promote the SM fate by inhibiting the expression of two BWM-specifying transcription factors. In light of recent findings in mammals showing that Sall4, one of the mammalian homologs of SEM-4, contributes to pluripotency regulation by inhibiting differentiation, our work suggests that the function of SEM-4/SALL proteins in regulating pluripotency versus differentiation appears to be evolutionarily conserved. Copyright © 2017 Elsevier Inc. All rights reserved.

Changes in surface characteristics of two different resin composites after 1 year water storage: An SEM and AFM study.

Science.gov (United States)

Tekçe, Neslihan; Pala, Kansad; Demirci, Mustafa; Tuncer, Safa

2016-11-01

To evaluate changes in surface characteristics of two different resin composites after 1 year of water storage using a profilometer, Vickers hardness, scanning electron microscopy (SEM), and atomic force microscopy (AFM). A total of 46 composite disk specimens (10 mm in diameter and 2 mm thick) were fabricated using Clearfil Majesty Esthetic and Clearfil Majesty Posterior (Kuraray Medical Co, Tokyo, Japan). Ten specimens from each composite were used for surface roughness and microhardness tests (n = 10). For each composite, scanning electron microscope (SEM, n = 2) and atomic force microscope (AFM, n = 1) images were obtained after 24 h and 1 year of water storage. The data were analyzed using two-way analysis of variance and a post-hoc Bonferroni test. Microhardness values of Clearfil Majesty Esthetic decreased significantly (78.15-63.74, p = 0.015) and surface roughness values did not change after 1 year of water storage (0.36-0.39, p = 0.464). Clearfil Majesty Posterior microhardness values were quite stable (138.74-137.25, p = 0.784), and surface roughness values increased significantly (0.39-0.48, p = 0.028) over 1 year. One year of water storage caused microhardness values for Clearfil Majesty Esthetic to decrease and the surface roughness of Clearfil Majesty Posterior increased. AFM and SEM images demonstrated surface detoration of the materials after 1 year and ensured similar results with the quantitative test methods. SCANNING 38:694-700, 2016. © 2016 Wiley Periodicals, Inc. © Wiley Periodicals, Inc.

Using BIB-SEM to determine pore morphology and pore size distributions in coal macerals

Energy Technology Data Exchange (ETDEWEB)

Giffin, S.; Littke, R. [RWTH Aachen Univ. (Germany). Inst. of Geology and Geochemistry of Petroleum and Coal; Klaver, J.; Urai, J.L. [RWTH Aachen Univ. (Germany). Structural Geology, Tectonics and Geomechanics

2013-08-01

The composition of coalbeds is considerably heterogeneous, affecting the transport pathways for fluids within the coal. Transport pathways include cleats and larger pores. However, only a few clues exist as the nature of these pores. This study examines the morphology and distribution of macro- and mesopores in coal samples, using broad ion beam (BIB) milling to prepare relief- and damage-free polished surfaces of coal samples for high-resolution SEM imaging. Broad ion beam milling is advantageous to focused ion beam milling in that a larger surface area can be milled. Combining that with SEM imaging results in a useful tool to study pore morphology and distributions in the size range between 10 nm and 10 {mu}m. Since BIB-sections of a few square millimeters are not large enough to be statistically representative, results cannot be easily interpreted from a coal seam standpoint. Therefore, porosity was investigated as a function of maceral type to characterize pore morphologies. Macerals from the vitrinite and inertinite groups were selected with a known relationship to bedding. BIB-sections were milled parallel to bedding and perpendicular to bedding, and the pores were evaluated in each section. The goal of this study is to (1) qualitatively describe pore morphology with respect to maceral type and (2) quantitatively characterize pore size distributions with respect to maceral and in relationship to bedding. Our results lead to a better understanding of bulk coal porosity due to the visual, spatial representation and quantification of pores in individual macerals. (orig.)

Polarization-dependent Imaging Contrast (PIC) mapping reveals nanocrystal orientation patterns in carbonate biominerals

Energy Technology Data Exchange (ETDEWEB)

Gilbert, Pupa U.P.A., E-mail: pupa@physics.wisc.edu [University of Wisconsin-Madison, Departments of Physics and Chemistry, Madison, WI 53706 (United States)

2012-10-15

Highlights: Black-Right-Pointing-Pointer Nanocrystal orientation shown by Polarization-dependent Imaging Contrast (PIC) maps. Black-Right-Pointing-Pointer PIC-mapping of carbonate biominerals reveals their ultrastructure at the nanoscale. Black-Right-Pointing-Pointer The formation mechanisms of biominerals is discovered by PIC-mapping using PEEM. -- Abstract: Carbonate biominerals are one of the most interesting systems a physicist can study. They play a major role in the CO{sub 2} cycle, they master templation, self-assembly, nanofabrication, phase transitions, space filling, crystal nucleation and growth mechanisms. A new imaging modality was introduced in the last 5 years that enables direct observation of the orientation of carbonate single crystals, at the nano- and micro-scale. This is Polarization-dependent Imaging Contrast (PIC) mapping, which is based on X-ray linear dichroism, and uses PhotoElectron Emission spectroMicroscopy (PEEM). Here we present PIC-mapping results from biominerals, including the nacre and prismatic layers of mollusk shells, and sea urchin teeth. We describe various PIC-mapping approaches, and show that these lead to fundamental discoveries on the formation mechanisms of biominerals.

A new clustering algorithm for scanning electron microscope images

Science.gov (United States)

Yousef, Amr; Duraisamy, Prakash; Karim, Mohammad

2016-04-01

A scanning electron microscope (SEM) is a type of electron microscope that produces images of a sample by scanning it with a focused beam of electrons. The electrons interact with the sample atoms, producing various signals that are collected by detectors. The gathered signals contain information about the sample's surface topography and composition. The electron beam is generally scanned in a raster scan pattern, and the beam's position is combined with the detected signal to produce an image. The most common configuration for an SEM produces a single value per pixel, with the results usually rendered as grayscale images. The captured images may be produced with insufficient brightness, anomalous contrast, jagged edges, and poor quality due to low signal-to-noise ratio, grained topography and poor surface details. The segmentation of the SEM images is a tackling problems in the presence of the previously mentioned distortions. In this paper, we are stressing on the clustering of these type of images. In that sense, we evaluate the performance of the well-known unsupervised clustering and classification techniques such as connectivity based clustering (hierarchical clustering), centroid-based clustering, distribution-based clustering and density-based clustering. Furthermore, we propose a new spatial fuzzy clustering technique that works efficiently on this type of images and compare its results against these regular techniques in terms of clustering validation metrics.

Tillandsia stricta Sol (Bromeliaceae) leaves as monitors of airborne particulate matter-A comparative SEM methods evaluation: Unveiling an accurate and odd HP-SEM method.

Science.gov (United States)

de Oliveira, Martha Lima; de Melo, Edésio José Tenório; Miguens, Flávio Costa

2016-09-01

Airborne particulate matter (PM) has been included among the most important air pollutants by governmental environment agencies and academy researchers. The use of terrestrial plants for monitoring PM has been widely accepted, particularly when it is coupled with SEM/EDS. Herein, Tillandsia stricta leaves were used as monitors of PM, focusing on a comparative evaluation of Environmental SEM (ESEM) and High-Pressure SEM (HPSEM). In addition, specimens air-dried at formaldehyde atmosphere (AD/FA) were introduced as an SEM procedure. Hydrated specimen observation by ESEM was the best way to get information from T. stricta leaves. If any artifacts were introduced by AD/FA, they were indiscernible from those caused by CPD. Leaf anatomy was always well preserved. PM density was determined on adaxial and abaxial leaf epidermis for each of the SEM proceedings. When compared with ESEM, particle extraction varied from 0 to 20% in air-dried leaves while 23-78% of particles deposited on leaves surfaces were extracted by CPD procedures. ESEM was obviously the best choice over other methods but morphological artifacts increased in function of operation time while HPSEM operation time was without limit. AD/FA avoided the shrinkage observed in the air-dried leaves and particle extraction was low when compared with CPD. Structural and particle density results suggest AD/FA as an important methodological approach to air pollution biomonitoring that can be widely used in all electron microscopy labs. Otherwise, previous PM assessments using terrestrial plants as biomonitors and performed by conventional SEM could have underestimated airborne particulate matter concentration. © 2016 Wiley Periodicals, Inc.

O Cinema sem Imagens

Directory of Open Access Journals (Sweden)

Paulo Andrade

2001-12-01

Full Text Available A obra cinematográfica de Marguerite Duras, praticamente desconhecida pelo grande público, estabeleça intricadas relações com sua obra literária, ao promover a indiscernibilidade entre os dois campo, sem, contudo, instituir qualquer tipo de subordinação de um ao outro. O processo de criação do filme Lê camion, de 1977, aponta para outras possibilidades de se pensar o cinema e a literatura.

From the SEM (IAEA) to the SIMS (ITU): Re-location experiment of μm-size particles - first results

International Nuclear Information System (INIS)

Admon, U.; Donohue, D.; Aigner, H.; Tamborini, G.; Bildstein, O.; Betti, M.

2002-01-01

Full text: Nuclear forensic analysis of individual radioactive particles in the μm-size range can be performed in two steps: in the first, an automated SEM screening of the loaded sample holder, particles of interest (POIs) are located and classified according to their elemental composition and size. In the second, the sample is transferred to a mass spectrometer (usually a SIMS), and individual POIs are re-located and further analyzed for their isotopic composition. Alternatively, selected POIs can be extracted after SEM screening or fission track analysis, and then analyzed in a TIMS or ICPMS. In the SIMS, which has imaging capability of its own, the whole sample is manipulated to bring specific POIs to the ion-beam point of impingement. In all these cases, including re-visiting POIs in the SEM itself, a precise relocation method is essential. The re-location of POIs in the SIMS after they have been identified as such in the SEM is based on the triangulation method. A set of reference marks are 'printed' by vacuum-deposition of metallic thin-film patterns on the sample holder, a flat-polished graphite planchet. These marks, easily recognizable and precisely measurable by both instruments, serve as inherent coordinate system for each sample. The SEM screening provides a list of POIs, each with a data profile comprising stage coordinates, composition, and size. Having measured the stage coordinates of at least 3 linearly-independent reference marks in the SEM and in the SIMS allows predicting the SIMS stage coordinates where the POIs can be found. This paper describes a joint IAEA-ITU experiment aimed at testing the feasibility of the relocation method in two separate laboratories. A flat-polished graphite planchet was loaded with a small number (a few hundreds) of μm-size uranium particles using the NIST method [3] in the ITU clean laboratory. The sample was sent to the IAEA clean laboratory, where the reference marks pattern was 'printed' by vacuum

Computer image analysis of etched tracks from ionizing radiation

Science.gov (United States)

Blanford, George E.

1994-01-01

I proposed to continue a cooperative research project with Dr. David S. McKay concerning image analysis of tracks. Last summer we showed that we could measure track densities using the Oxford Instruments eXL computer and software that is attached to an ISI scanning electron microscope (SEM) located in building 31 at JSC. To reduce the dependence on JSC equipment, we proposed to transfer the SEM images to UHCL for analysis. Last summer we developed techniques to use digitized scanning electron micrographs and computer image analysis programs to measure track densities in lunar soil grains. Tracks were formed by highly ionizing solar energetic particles and cosmic rays during near surface exposure on the Moon. The track densities are related to the exposure conditions (depth and time). Distributions of the number of grains as a function of their track densities can reveal the modality of soil maturation. As part of a consortium effort to better understand the maturation of lunar soil and its relation to its infrared reflectance properties, we worked on lunar samples 67701,205 and 61221,134. These samples were etched for a shorter time (6 hours) than last summer's sample and this difference has presented problems for establishing the correct analysis conditions. We used computer counting and measurement of area to obtain preliminary track densities and a track density distribution that we could interpret for sample 67701,205. This sample is a submature soil consisting of approximately 85 percent mature soil mixed with approximately 15 percent immature, but not pristine, soil.

SEM probe of IC radiation sensitivity

Science.gov (United States)

Gauthier, M. K.; Stanley, A. G.

1979-01-01

Scanning Electron Microscope (SEM) used to irradiate single integrated circuit (IC) subcomponent to test for radiation sensitivity can localize area of IC less than .03 by .03 mm for determination of exact location of radiation sensitive section.

Comparative SEM analysis of nine F22 aligner cleaning strategies

Directory of Open Access Journals (Sweden)

Luca Lombardo

2017-09-01

Full Text Available Abstract Background The orthodontics industry has paid great attention to the aesthetics of orthodontic appliances, seeking to make them as invisible as possible. There are several advantages to clear aligner systems, including aesthetics, comfort, chairside time reduction, and the fact that they can be removed for meals and oral hygiene procedures. Methods Five patients were each given a series of F22 aligners, each to be worn for 14 days and nights, with the exception of meal and brushing times. Patients were instructed to clean each aligner using a prescribed strategy, and sections of the used aligners were observed under SEM. One grey-scale SEM image was saved per aligner in JPEG format with an 8-bit colour depth, and a total of 45 measurements on the grey scale (“Value” variable were made. This dataset was analysed statistically via repeated measures ANOVA to determine the effect of each of the nine cleaning strategies in each of the five patients. Results A statistically significant difference in the efficacy of the cleaning strategies was detected. Specifically, rinsing with water alone was significantly less efficacious, and a combination of cationic detergent solution and ultrasonication was significantly more efficacious than the other methods (p < 0.05. Conclusions Of the nine cleaning strategies examined, only that involving 5 min of ultrasonication at 42 k Hz combined with a 0.3% germicidal cationic detergent was observed to be statistically effective at removing the bacterial biofilm from the surface of F22 aligners.

Sem and phylogenetic analysis of naturalized and cultivated Epidendrum in Hawaii

International Nuclear Information System (INIS)

White, Ingelia P.; Porter, Brad W.; Chinen, Kimberley; Fay, Michael F.

2013-01-01

Naturalized populations of Epidendrum L. are found on a rocky hillside in Nuuanu-Pali and Olomana in the Koolau Mountains of Oahu, Hawaii. Scanning electron micrographs were taken to observe polymorphism among the pollinia, petals, leaves, and root tips of two Epidendrum specimens (one naturalized specimen from Nuuanu-Pali and one cultivated specimen in the greenhouse). SEM images of pollen from the naturalized Epidendrum have revealed a length of 830.31 μm and a width of 462.58 μm. Pollen length from the cultivated cultivar, by comparison, has been 724.60 μm and the width 276.17 μm. Differing cell structures on the lower surface of the petals were also observed. Polyhedral concave cells with numerous fossae (pits) were seen on the naturalized cultivar and elongated flattened cells on the cultivated one. Transections of the leaf of the naturalized specimen have been much thinner (546.33 μm) compared to the thickness of the cultivated cultivar leaf (1505.83 μm), which has contained more spongy parenchyma cells. A thinner root tip (1094.19 μm) was seen in the naturalized cultivar, as opposed to 1636.34 μm in the cultivated specimen. Relationships were compared between these two specimens along with ten other unknown Epidendrum cultivars, the plastid trnL-F gene region and conducted parsimony analysis were sequenced among the naturalized Epidendrum from Nuuanu-Pali At least six changes have separated these specimens into two clades. Shorter and longer plastid simple sequence has repeated (cpSSR) from the rps16-trnK region support separation of the five Epidendrum genotypes evaluated into these two groups, including a naturalized Epidendrum from Olomana. (author)

Three-dimensional analysis of somatic mitochondrial dynamics in fission-deficient injured motor neurons using FIB/SEM.

Science.gov (United States)

Tamada, Hiromi; Kiryu-Seo, Sumiko; Hosokawa, Hiroki; Ohta, Keisuke; Ishihara, Naotada; Nomura, Masatoshi; Mihara, Katsuyoshi; Nakamura, Kei-Ichiro; Kiyama, Hiroshi

2017-08-01

Mitochondria undergo morphological changes through fusion and fission for their quality control, which are vital for neuronal function. In this study, we examined three-dimensional morphologies of mitochondria in motor neurons under normal, nerve injured, and nerve injured plus fission-impaired conditions using the focused ion beam/scanning electron microscopy (FIB/SEM), because the FIB/SEM technology is a powerful tool to demonstrate both 3D images of whole organelle and the intra-organellar structure simultaneously. Crossing of dynamin-related protein 1 (Drp1) gene-floxed mice with neuronal injury-specific Cre driver mice, Atf3:BAC Tg mice, allowed for Drp1 ablation specifically in injured neurons. FIB/SEM analysis demonstrated that somatic mitochondrial morphologies in motor neurons were not altered before or after nerve injury. However, the fission impairment resulted in prominent somatic mitochondrial enlargement, which initially induced complex morphologies with round regions and long tubular processes, subsequently causing a decrease in the number of processes and further enlargement of the round regions, which eventually resulted in big spheroidal mitochondria without processes. The abnormal mitochondria exhibited several degradative morphologies: local or total cristae collapse, vacuolization, and mitophagy. These suggest that mitochondrial fission is crucial for maintaining mitochondrial integrity in injured motor neurons, and multiple forms of mitochondria degradation may accelerate neuronal degradation. © 2017 Wiley Periodicals, Inc.

78 FR 55772 - Culturally Significant Object Imported for Exhibition Determinations: “Beauty Revealed: Images of...

Science.gov (United States)

2013-09-11

..., 1965 (79 Stat. 985; 22 U.S.C. 2459), Executive Order 12047 of March 27, 1978, the Foreign Affairs...). The mailing address is U.S. Department of State, SA-5, L/PD, Fifth Floor (Suite 5H03), Washington, DC... Determinations: ``Beauty Revealed: Images of Women in Qing Dynasty Chinese Painting'' SUMMARY: Notice is hereby...

Imaging experimental coronary artery thrombosis with indium-111 platelets

International Nuclear Information System (INIS)

Riba, A.L.; Thakur, M.L.; Gottschalk, A.; Zaret, B.L.

1979-01-01

The ability of cardiac scintigraphy with indium-111 ( 111 In)-labeled platelets to detect coronary artery thrombosis (CAT) was assessed in a canine model. Cardiac imaging and tissue distribution studies were performed shortly after administering 111 In-labeled platelets to 12 dogs (group 1) with acute CAT. Four dogs (group 2) with acute CAT were studied 2 and 22 hours after administering 111 In platelets. In addition, four dogs (group 3) with 24-hour-old CAT were similarly evaluated. In all group 1 animals, in vivo imaging 1 to 2 hours after 111 In platelet administration revealed intense uptake in the region of thrombus-containing left anterior descending arteries that was readily discernible from background blood pool activity. Sequential imaging of the four group 2 animals over a 22-hour period revealed no change in the scintigraphic pattern of the thrombosed arteries. In contrast, 111 In platelet imaging in the four group 3 animals with 24-hour-old CAT failed to reveal enhanced activity within the region of the thrombus-containing coronary artery. In the 12 group 1 animals, the CAT accumulated 69 +- 10 (mean +- SEM) times greater activity than present in blood and 651 +- 135 times greater activity than normal left ventricular myocardium. There was 24 +- 7 times greater 111 In activity in the damaged left anterior descending arteries compared with normal circumflex arteries. Similar uptake ratios were seen in group 2 animals. The 24-hour old thrombi from group 3 animals showed no enhanced 111 In uptake. This study demonstrates that experimental acute CAT can be detected readily with 111 In platelet cardiac scintigraphy

SEM investigation of incandescent lamp mantle structure on durability

International Nuclear Information System (INIS)

Gerneke, D.; Lang, C.

2002-01-01

Full text: The incandescent mantle as used on pressure and non-pressure liquid fuel lamps has been in use for over 100 years. What remains unexplained is the way in which the resistance to mechanical shock and the decline in tensile strength with usage is experienced. It has been suggested that to improve durability it is necessary to continuously burn a new mantle for the first two to three hours. The known factors in mantle durability and mechanical strength are chemical composition and fabric weave. This study was undertaken to investigate the effects of burning time and temperature on thorium oxide mantles. The operating temperature of mantles on a range of kerosene pressure lamps was measured and found to be between 800 and 1100 deg C. Heat treatments of thorium based Coleman mantles were carried out in a laboratory furnace within these ranges of temperatures for periods ranging from 2 minutes to 2 hours. The mantles were then viewed in a LEO S440 analytical SEM. Results at 800 deg C show a distinct change in surface morphology with increasing exposure time. At the shorter times (2-5 minutes) the surface was relatively smooth. With increased time periods (15 - 120 minutes) the surface was observed to have a large lumpy structure. At 1100 deg C the difference in surface morphology was not apparent between the shortest and longest times. The surface appears much smoother and no lumpy structure was observed. This suggests that when a mantle is operated at the higher temperature of 1100 deg C the structure of the Thorium oxide is quickly transformed into the known stronger amorphous form. This is taken as the observed smooth structure seen in the SEM images of the 1100 deg C samples. Thus the mantle is expected to be more resistant to mechanical shock and have increased durability. Practical field test results confirm these observations. The mantle on a lamp that is operating efficiently, burns brightly, will far outlast a mantle on an inefficient lamp which bums

Sexual Arousal and Sexually Explicit Media (SEM: Comparing Patterns of Sexual Arousal to SEM and Sexual Self-Evaluations and Satisfaction Across Gender and Sexual Orientation

Directory of Open Access Journals (Sweden)

Gert Martin Hald, PhD

2018-03-01

Hald GM, Stulhofer A, Lange T, et al. Sexual Arousal and Sexually Explicit Media (SEM: Comparing Patterns of Sexual Arousal to SEM and Sexual Self-Evaluations and Satisfaction Across Gender and Sexual Orientation. Sex Med 2018;6:30–38.

Fluorescence Imaging Reveals Surface Contamination

Science.gov (United States)

Schirato, Richard; Polichar, Raulf

1992-01-01

In technique to detect surface contamination, object inspected illuminated by ultraviolet light to make contaminants fluoresce; low-light-level video camera views fluorescence. Image-processing techniques quantify distribution of contaminants. If fluorescence of material expected to contaminate surface is not intense, tagged with low concentration of dye.

Calcium Imaging Reveals Coordinated Simple Spike Pauses in Populations of Cerebellar Purkinje Cells

Directory of Open Access Journals (Sweden)

Jorge E. Ramirez

2016-12-01

Full Text Available The brain’s control of movement is thought to involve coordinated activity between cerebellar Purkinje cells. The results reported here demonstrate that somatic Ca2+ imaging is a faithful reporter of Na+-dependent “simple spike” pauses and enables us to optically record changes in firing rates in populations of Purkinje cells in brain slices and in vivo. This simultaneous calcium imaging of populations of Purkinje cells reveals a striking spatial organization of pauses in Purkinje cell activity between neighboring cells. The source of this organization is shown to be the presynaptic gamma-Aminobutyric acid producing (GABAergic network, and blocking ionotropic gamma-Aminobutyric acid receptor (GABAARs abolishes the synchrony. These data suggest that presynaptic interneurons synchronize (inactivity between neighboring Purkinje cells, and thereby maximize their effect on downstream targets in the deep cerebellar nuclei.

From patterns to causal understanding: Structural equation modeling (SEM) in soil ecology

Science.gov (United States)

Eisenhauer, Nico; Powell, Jeff R; Grace, James B.; Bowker, Matthew A.

2015-01-01

In this perspectives paper we highlight a heretofore underused statistical method in soil ecological research, structural equation modeling (SEM). SEM is commonly used in the general ecological literature to develop causal understanding from observational data, but has been more slowly adopted by soil ecologists. We provide some basic information on the many advantages and possibilities associated with using SEM and provide some examples of how SEM can be used by soil ecologists to shift focus from describing patterns to developing causal understanding and inspiring new types of experimental tests. SEM is a promising tool to aid the growth of soil ecology as a discipline, particularly by supporting research that is increasingly hypothesis-driven and interdisciplinary, thus shining light into the black box of interactions belowground.

The relationship between cost estimates reliability and BIM adoption: SEM analysis

Science.gov (United States)

Ismail, N. A. A.; Idris, N. H.; Ramli, H.; Rooshdi, R. R. Raja Muhammad; Sahamir, S. R.

2018-02-01

This paper presents the usage of Structural Equation Modelling (SEM) approach in analysing the effects of Building Information Modelling (BIM) technology adoption in improving the reliability of cost estimates. Based on the questionnaire survey results, SEM analysis using SPSS-AMOS application examined the relationships between BIM-improved information and cost estimates reliability factors, leading to BIM technology adoption. Six hypotheses were established prior to SEM analysis employing two types of SEM models, namely the Confirmatory Factor Analysis (CFA) model and full structural model. The SEM models were then validated through the assessment on their uni-dimensionality, validity, reliability, and fitness index, in line with the hypotheses tested. The final SEM model fit measures are: P-value=0.000, RMSEA=0.0790.90, TLI=0.956>0.90, NFI=0.935>0.90 and ChiSq/df=2.259; indicating that the overall index values achieved the required level of model fitness. The model supports all the hypotheses evaluated, confirming that all relationship exists amongst the constructs are positive and significant. Ultimately, the analysis verified that most of the respondents foresee better understanding of project input information through BIM visualization, its reliable database and coordinated data, in developing more reliable cost estimates. They also perceive to accelerate their cost estimating task through BIM adoption.

Structural Equations and Causal Explanations: Some Challenges for Causal SEM

Science.gov (United States)

Markus, Keith A.

2010-01-01

One common application of structural equation modeling (SEM) involves expressing and empirically investigating causal explanations. Nonetheless, several aspects of causal explanation that have an impact on behavioral science methodology remain poorly understood. It remains unclear whether applications of SEM should attempt to provide complete…

SEM-REV: A sea test site for Marine Energy Converter

International Nuclear Information System (INIS)

Berhault, Christian; Le Crom, Izan; Le Bihan, Gerard

2015-01-01

Thanks to a main funding of Region des Pays de la Loire, the sea test site SEM-REV has been developed by Ecole Centrale de Nantes since 2007 to test both Wave Energy Converters and Floating Wind Turbine in real sea conditions. The sea test site is equipped with a set of oceanographic sensors and with an electric cable of 8 MW, connected to the French grid. The project is located close to Le Croisic, Western coast of France. SEM-REV is one of the main test facilities operated by Ecole Centrale de Nantes to support MRE technologies development. After presenting the initial motivations of the SEM-REV development, the paper describes, in parts 1 and 2, the complete administrative and technical processes that were followed to reach SEM-REV commissioning in 2014. The third part is focused on the exploitation process, including technical and contractual specifications imposed to the MRE developers for installation, tests and decommissioning phases. Some words are given also on the R and D projects using the SEM-REV in-situ monitoring system: prediction of environmental conditions, bio-fooling, acoustic impact. Even if operational phase is not started, expected extensions of the tests site are listed. (authors)

Cerebral imaging revealing Alzheimer's disease

International Nuclear Information System (INIS)

2011-01-01

Cerebral imaging is the only non-invasive means of examining the brain and is essential in studying Alzheimer's disease. As a tool for early diagnosis, evaluation and treatment monitoring, this technology is at the heart of the research being done to further improve its reliability and sensitivity. (authors)

Monte Carlo simulation of secondary electron images for gold nanorods on the silicon substrate

Science.gov (United States)

Zhang, P.

2018-06-01

Recently, gold nanorods (Au NRs) have attracted much attention because at a particular photoelectricity the gold nanorods present a characteristic which is different from other types of Au nanomaterials with various shapes. Accurate measurement of aspect ratios does provide very high value of optical property for Au NRs. Monte Carlo (MC) simulation is thought of as the most accurate tool to perform size measurement through extracting structure parameters from the simulated scanning electron microscopy (SEM) image which best matches the experimental one. In this article, a series of MC-simulated secondary electron (SE) images have been taken for Au NRs on a silicon substrate. However, it has already been observed that the two ends of Au NRs in the experimental SEM image is brighter than that of the middle part. It seriously affects the accuracy of size measurement for Au NRs. The purpose of this work is to understand the mechanism underlying this phenomenon through a series of systematical analysis. It was found that the cetyltrimethylammonium bromide (CTAB) which covers the Au NRs indeed can alter the contrast of Au NRs compared to that without CTAB covering. However, SEs emitting from CTAB are not the reason for the abnormal brightness at the two ends of NRs. This work reveals that the charging effect might be the leading cause for this phenomenon.

Multiscale image analysis reveals structural heterogeneity of the cell microenvironment in homotypic spheroids.

Science.gov (United States)

Schmitz, Alexander; Fischer, Sabine C; Mattheyer, Christian; Pampaloni, Francesco; Stelzer, Ernst H K

2017-03-03

Three-dimensional multicellular aggregates such as spheroids provide reliable in vitro substitutes for tissues. Quantitative characterization of spheroids at the cellular level is fundamental. We present the first pipeline that provides three-dimensional, high-quality images of intact spheroids at cellular resolution and a comprehensive image analysis that completes traditional image segmentation by algorithms from other fields. The pipeline combines light sheet-based fluorescence microscopy of optically cleared spheroids with automated nuclei segmentation (F score: 0.88) and concepts from graph analysis and computational topology. Incorporating cell graphs and alpha shapes provided more than 30 features of individual nuclei, the cellular neighborhood and the spheroid morphology. The application of our pipeline to a set of breast carcinoma spheroids revealed two concentric layers of different cell density for more than 30,000 cells. The thickness of the outer cell layer depends on a spheroid's size and varies between 50% and 75% of its radius. In differently-sized spheroids, we detected patches of different cell densities ranging from 5 × 10 5 to 1 × 10 6  cells/mm 3 . Since cell density affects cell behavior in tissues, structural heterogeneities need to be incorporated into existing models. Our image analysis pipeline provides a multiscale approach to obtain the relevant data for a system-level understanding of tissue architecture.

Quantum dot-based local field imaging reveals plasmon-based interferometric logic in silver nanowire networks.

Science.gov (United States)

Wei, Hong; Li, Zhipeng; Tian, Xiaorui; Wang, Zhuoxian; Cong, Fengzi; Liu, Ning; Zhang, Shunping; Nordlander, Peter; Halas, Naomi J; Xu, Hongxing

2011-02-09

We show that the local electric field distribution of propagating plasmons along silver nanowires can be imaged by coating the nanowires with a layer of quantum dots, held off the surface of the nanowire by a nanoscale dielectric spacer layer. In simple networks of silver nanowires with two optical inputs, control of the optical polarization and phase of the input fields directs the guided waves to a specific nanowire output. The QD-luminescent images of these structures reveal that a complete family of phase-dependent, interferometric logic functions can be performed on these simple networks. These results show the potential for plasmonic waveguides to support compact interferometric logic operations.

Actinic imaging of native and programmed defects on a full-field mask

Energy Technology Data Exchange (ETDEWEB)

Mochi, I.; Goldberg, K. A.; Fontaine, B. La; Tchikoulaeva, A.; Holfeld, C.

2010-03-12

We describe the imaging and characterization of native defects on a full field extreme ultraviolet (EUV) mask, using several reticle and wafer inspection modes. Mask defect images recorded with the SEMA TECH Berkeley Actinic Inspection Tool (AIT), an EUV-wavelength (13.4 nm) actinic microscope, are compared with mask and printed-wafer images collected with scanning electron microscopy (SEM) and deep ultraviolet (DUV) inspection tools. We observed that defects that appear to be opaque in the SEM can be highly transparent to EUV light, and inversely, defects that are mostly transparent to the SEM can be highly opaque to EUV. The nature and composition of these defects, whether they appear on the top surface, within the multilayer coating, or on the substrate as buried bumps or pits, influences both their significance when printed, and their detectability with the available techniques. Actinic inspection quantitatively predicts the characteristics of printed defect images in ways that may not be possible with non-EUV techniques. As a quantitative example, we investigate the main structural characteristics of a buried pit defect based on EUV through-focus imaging.

DETECTION OF DELAMINATION IN A COMPOSITE PLATE BY SEM

Institute of Scientific and Technical Information of China (English)

无

2001-01-01

A numerical method of integration of Green's functi ons of strip element method (SEM) is proposed. The response of ultrasonic sourc e generated by a transducer on the surface of a multi-ply composite plate conta ining a delamination is analyzed by the use of SEM. The numerical results show that the scanning features of the ultrasonic waves may be used to identify the d elamination inside the composite plate .

Simulation study of secondary electron images in scanning ion microscopy

CERN Document Server

Ohya, K

2003-01-01

The target atomic number, Z sub 2 , dependence of secondary electron yield is simulated by applying a Monte Carlo code for 17 species of metals bombarded by Ga ions and electrons in order to study the contrast difference between scanning ion microscopes (SIM) and scanning electron microscopes (SEM). In addition to the remarkable reversal of the Z sub 2 dependence between the Ga ion and electron bombardment, a fine structure, which is correlated to the density of the conduction band electrons in the metal, is calculated for both. The brightness changes of the secondary electron images in SIM and SEM are simulated using Au and Al surfaces adjacent to each other. The results indicate that the image contrast in SIM is much more sensitive to the material species and is clearer than that for SEM. The origin of the difference between SIM and SEM comes from the difference in the lateral distribution of secondary electrons excited within the escape depth.

X-ray microscopy as an approach to increasing accuracy and efficiency of serial block-face imaging for correlated light and electron microscopy of biological specimens.

Science.gov (United States)

Bushong, Eric A; Johnson, Donald D; Kim, Keun-Young; Terada, Masako; Hatori, Megumi; Peltier, Steven T; Panda, Satchidananda; Merkle, Arno; Ellisman, Mark H

2015-02-01

The recently developed three-dimensional electron microscopic (EM) method of serial block-face scanning electron microscopy (SBEM) has rapidly established itself as a powerful imaging approach. Volume EM imaging with this scanning electron microscopy (SEM) method requires intense staining of biological specimens with heavy metals to allow sufficient back-scatter electron signal and also to render specimens sufficiently conductive to control charging artifacts. These more extreme heavy metal staining protocols render specimens light opaque and make it much more difficult to track and identify regions of interest (ROIs) for the SBEM imaging process than for a typical thin section transmission electron microscopy correlative light and electron microscopy study. We present a strategy employing X-ray microscopy (XRM) both for tracking ROIs and for increasing the efficiency of the workflow used for typical projects undertaken with SBEM. XRM was found to reveal an impressive level of detail in tissue heavily stained for SBEM imaging, allowing for the identification of tissue landmarks that can be subsequently used to guide data collection in the SEM. Furthermore, specific labeling of individual cells using diaminobenzidine is detectable in XRM volumes. We demonstrate that tungsten carbide particles or upconverting nanophosphor particles can be used as fiducial markers to further increase the precision and efficiency of SBEM imaging.

Phase-selective staining of metal salt for scanning electron microscopy imaging of block copolymer film

Energy Technology Data Exchange (ETDEWEB)

Li, Jing Ze, E-mail: Lijinge@uestc.edu.cn [State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Microelectronic and Solid-state Electronic, University of Electronic Science and Technology of China, Chengdu 610054 (China); State Key Laboratory of Polymer Materials Engineering (Sichuan University), Chengdu 610054 (China); Xinjiang Key Laboratory of Electronic Information Materials and Devices, Urumuqi 830011 (China); Wang, Ying; Hong Wang, Zhi; Mei, Di; Zou, Wei [State Key Laboratory of Electronic Thin Films and Integrated Devices, School of Microelectronic and Solid-state Electronic, University of Electronic Science and Technology of China, Chengdu 610054 (China); Min Chang, Ai [State Key Laboratory of Polymer Materials Engineering (Sichuan University), Chengdu 610054 (China); Wang, Qi [Xinjiang Key Laboratory of Electronic Information Materials and Devices, Urumuqi 830011 (China); Komura, Motonori; Ito, Kaori [Division of Integrated Molecular Engineering, Chemical Resources Laboratory, Tokyo Institute of Technology, Yokohama 226-8503 (Japan); Iyoda, Tomokazu, E-mail: Iyoda.t.aa@m.titech.ac.jp [Division of Integrated Molecular Engineering, Chemical Resources Laboratory, Tokyo Institute of Technology, Yokohama 226-8503 (Japan)

2010-09-15

Three metal salts, i.e., AgNO{sub 3}, HAuCl{sub 4}, and KCl, were proposed as novel staining reagents instead of traditional RuO{sub 4} and OsO{sub 4} labeled with expensive price and extreme toxicity for scanning electron microscopy (SEM) imaging of microphase separated block copolymer film. A simple and costless aqueous solution immersion procedure could ensure selective staining of the metal slat in specific phase of the nanostructured copolymer film, leading to a clear phase contrasted SEM image. The heavy metal salt has better staining effect, demonstrating stable and high signal-to-noise SEM image even at an acceleration voltage as high as 30 kV and magnification up to 250,000 times.

MMP-13 In-Vivo Molecular Imaging Reveals Early Expression in Lung Adenocarcinoma.

Directory of Open Access Journals (Sweden)

Mathieu Salaün

Full Text Available Several matrix metalloproteinases (MMPs are overexpressed in lung cancer and may serve as potential targets for the development of bioactivable probes for molecular imaging.To characterize and monitor the activity of MMPs during the progression of lung adenocarcinoma.K-rasLSL-G12D mice were imaged serially during the development of adenocarcinomas using fluorescence molecular tomography (FMT and a probe specific for MMP-2, -3, -9 and -13. Lung tumors were identified using FMT and MRI co-registration, and the probe concentration in each tumor was assessed at each time-point. The expression of Mmp2, -3, -9, -13 was quantified by qRT-PCR using RNA isolated from microdissected tumor cells. Immunohistochemical staining of overexpressed MMPs in animals was assessed on human lung tumors.In mice, 7 adenomas and 5 adenocarcinomas showed an increase in fluorescent signal on successive FMT scans, starting between weeks 4 and 8. qRT-PCR assays revealed significant overexpression of only Mmp-13 in mice lung tumors. In human tumors, a high MMP-13 immunostaining index was found in tumor cells from invasive lesions (24/27, but in none of the non-invasive (0/4 (p=0.001.MMP-13 is detected in early pulmonary invasive adenocarcinomas and may be a potential target for molecular imaging of lung cancer.

MMP-13 In-Vivo Molecular Imaging Reveals Early Expression in Lung Adenocarcinoma

Science.gov (United States)

Salaün, Mathieu; Peng, Jing; Hensley, Harvey H.; Roder, Navid; Flieder, Douglas B.; Houlle-Crépin, Solène; Abramovici-Roels, Olivia; Sabourin, Jean-Christophe; Thiberville, Luc; Clapper, Margie L.

2015-01-01

Introduction Several matrix metalloproteinases (MMPs) are overexpressed in lung cancer and may serve as potential targets for the development of bioactivable probes for molecular imaging. Objective To characterize and monitor the activity of MMPs during the progression of lung adenocarcinoma. Methods K-rasLSL-G12D mice were imaged serially during the development of adenocarcinomas using fluorescence molecular tomography (FMT) and a probe specific for MMP-2, -3, -9 and -13. Lung tumors were identified using FMT and MRI co-registration, and the probe concentration in each tumor was assessed at each time-point. The expression of Mmp2, -3, -9, -13 was quantified by qRT-PCR using RNA isolated from microdissected tumor cells. Immunohistochemical staining of overexpressed MMPs in animals was assessed on human lung tumors. Results In mice, 7 adenomas and 5 adenocarcinomas showed an increase in fluorescent signal on successive FMT scans, starting between weeks 4 and 8. qRT-PCR assays revealed significant overexpression of only Mmp-13 in mice lung tumors. In human tumors, a high MMP-13 immunostaining index was found in tumor cells from invasive lesions (24/27), but in none of the non-invasive (0/4) (p=0.001). Conclusion MMP-13 is detected in early pulmonary invasive adenocarcinomas and may be a potential target for molecular imaging of lung cancer. PMID:26193700

SEM investigation of heart tissue samples

International Nuclear Information System (INIS)

Saunders, R; Amoroso, M

2010-01-01

We used the scanning electron microscope to examine the cardiac tissue of a cow (Bos taurus), a pig (Sus scrofa), and a human (Homo sapiens). 1mm 3 blocks of left ventricular tissue were prepared for SEM scanning by fixing in 96% ethanol followed by critical point drying (cryofixation), then sputter-coating with gold. The typical ridged structure of the myofibrils was observed for all the species. In addition crystal like structures were found in one of the samples of the heart tissue of the pig. These structures were investigated further using an EDVAC x-ray analysis attachment to the SEM. Elemental x-ray analysis showed highest peaks occurred for gold, followed by carbon, oxygen, magnesium and potassium. As the samples were coated with gold for conductivity, this highest peak is expected. Much lower peaks at carbon, oxygen, magnesium and potassium suggest that a cystallized salt such as a carbonate was present in the tissue before sacrifice.

SEM investigation of heart tissue samples

Energy Technology Data Exchange (ETDEWEB)

Saunders, R; Amoroso, M [Physics Department, University of the West Indies, St. Augustine, Trinidad and Tobago, West Indies (Trinidad and Tobago)

2010-07-01

We used the scanning electron microscope to examine the cardiac tissue of a cow (Bos taurus), a pig (Sus scrofa), and a human (Homo sapiens). 1mm{sup 3} blocks of left ventricular tissue were prepared for SEM scanning by fixing in 96% ethanol followed by critical point drying (cryofixation), then sputter-coating with gold. The typical ridged structure of the myofibrils was observed for all the species. In addition crystal like structures were found in one of the samples of the heart tissue of the pig. These structures were investigated further using an EDVAC x-ray analysis attachment to the SEM. Elemental x-ray analysis showed highest peaks occurred for gold, followed by carbon, oxygen, magnesium and potassium. As the samples were coated with gold for conductivity, this highest peak is expected. Much lower peaks at carbon, oxygen, magnesium and potassium suggest that a cystallized salt such as a carbonate was present in the tissue before sacrifice.

Molecular imaging reveals elevated VEGFR-2 expression in retinal capillaries in diabetes: a novel biomarker for early diagnosis

Science.gov (United States)

Sun, Dawei; Nakao, Shintaro; Xie, Fang; Zandi, Souska; Bagheri, Abouzar; Kanavi, Mozhgan Rezaei; Samiei, Shahram; Soheili, Zahra-Soheila; Frimmel, Sonja; Zhang, Zhongyu; Ablonczy, Zsolt; Ahmadieh, Hamid; Hafezi-Moghadam, Ali

2014-01-01

Diabetic retinopathy (DR) is a microvascular complication of diabetes and a leading cause of vision loss. Biomarkers and methods for early diagnosis of DR are urgently needed. Using a new molecular imaging approach, we show up to 94% higher accumulation of custom designed imaging probes against vascular endothelial growth factor receptor 2 (VEGFR-2) in retinal and choroidal vessels of diabetic animals (PM. R., Samiei, S., Soheili, Z.-S., Frimmel, S., Zhang, Z., Ablonczy, Z., Ahmadieh, H., Hafezi-Moghadam, A. Molecular imaging reveals elevated VEGFR-2 expression in retinal capillaries in diabetes: a novel biomarker for early diagnosis. PMID:24903276

FIB/SEM technology and high-throughput 3D reconstruction of dendritic spines and synapses in GFP-labeled adult-generated neurons

Directory of Open Access Journals (Sweden)

Carles eBosch

2015-05-01

Full Text Available The fine analysis of synaptic contacts is usually performed using transmission electron microscopy (TEM and its combination with neuronal labeling techniques. However, the complex 3D architecture of neuronal samples calls for their reconstruction from serial sections. Here we show that focused ion beam/scanning electron microscopy (FIB/SEM allows efficient, complete, and automatic 3D reconstruction of identified dendrites, including their spines and synapses, from GFP/DAB-labeled neurons, with a resolution comparable to that of TEM. We applied this technology to analyze the synaptogenesis of labeled adult-generated granule cells (GCs in mice. 3D reconstruction of spines in GCs aged 3–4 and 8–9 weeks revealed two different stages of spine development and unexpected features of synapse formation, including vacant and branched spines and presynaptic terminals establishing synapses with up to 10 spines. Given the reliability, efficiency, and high resolution of FIB/SEM technology and the wide use of DAB in conventional EM, we consider FIB/SEM fundamental for the detailed characterization of identified synaptic contacts in neurons in a high-throughput manner.

Multiplex immunoassay for persistent organic pollutants in tilapia: comparison of imaging- and flow cytometry-based platforms using spectrally encoded paramagnetic microspheres

NARCIS (Netherlands)

Meimaridou, A.; Haasnoot, W.; Shelver, W.L.; Franek, M.; Nielen, M.W.F.

2013-01-01

Recent developments in spectrally encoded microspheres (SEMs)-based technologies provide high multiplexing possibilities. Most SEMs-based assays require a flow cytometer with sophisticated fluidics and optics. A new imaging super-paramagnetic SEMs-based alternative platform transports SEMs with

Building a SEM Analytics Reporting Portfolio

Science.gov (United States)

Goff, Jay W.; Williams, Brian G.; Kilgore, Wendy

2016-01-01

Effective strategic enrollment management (SEM) efforts require vast amounts of internal and external data to ensure that meaningful reporting and analysis systems can assist managers in decision making. A wide range of information is integral for leading effective and efficient student recruitment and retention programs. This article is designed…

A Teoria dos Blocos Semânticos em revisão

Directory of Open Access Journals (Sweden)

Julio Cesar Machado

2017-08-01

Full Text Available A Teoria dos Blocos Semânticos ocupa lugar significativo nos trabalhos mundiais em Semântica, Argumentação e Enunciação, dentre outros. Por isso sua pertinência para a Linguística reclama uma reflexão. O presente trabalho pretende refletir algumas reformulações na Teoria dos Blocos Semânticos nas últimas duas décadas, a saber: (a polifonia, (b bloco semântico, e (c quadrado argumentativo. Especificamente, trataremos das seguintes relações: (a’ da Teoria Polifônica da Enunciação à Teoria Argumentativa da Polifonia; (b’ do bloco semântico ao semi-bloco; e (c’ do quadrado argumentativo ao cubo argumentativo. A necessidade deste trabalho é duplamente justificada: (i devido à constante revisão teórica do arcabouço teórico deste saber, sobretudo na sua última década, característica de Marion Carel e de Oswald Ducrot; e (ii pela falta de tradução/circulação no Brasil de obras fundamentais no que tange à re-elaboração das noções chaves desta teoria.

Miniature Variable Pressure Scanning Electron Microscope for In-Situ Imaging and Chemical Analysis

Science.gov (United States)

Gaskin, Jessica A.; Jerman, Gregory; Gregory, Don; Sampson, Allen R.

2012-01-01

NASA Marshall Space Flight Center (MSFC) is leading an effort to develop a Miniaturized Variable Pressure Scanning Electron Microscope (MVP-SEM) for in-situ imaging and chemical analysis of uncoated samples. This instrument development will be geared towards operation on Mars and builds on a previous MSFC design of a mini-SEM for the moon (funded through the NASA Planetary Instrument Definition and Development Program). Because Mars has a dramatically different environment than the moon, modifications to the MSFC lunar mini-SEM are necessary. Mainly, the higher atmospheric pressure calls for the use of an electron gun that can operate at High Vacuum, rather than Ultra-High Vacuum. The presence of a CO2-rich atmosphere also allows for the incorporation of a variable pressure system that enables the in-situ analysis of nonconductive geological specimens. Preliminary testing of Mars meteorites in a commercial Environmental SEM(Tradmark) (FEI) confirms the usefulness of lowcurrent/low-accelerating voltage imaging and highlights the advantages of using the Mars atmosphere for environmental imaging. The unique capabilities of the MVP-SEM make it an ideal tool for pursuing key scientific goals of NASA's Flagship Mission Max-C; to perform in-situ science and collect and cache samples in preparation for sample return from Mars.

Inter-operator and inter-device agreement and reliability of the SEM Scanner.

Science.gov (United States)

Clendenin, Marta; Jaradeh, Kindah; Shamirian, Anasheh; Rhodes, Shannon L

2015-02-01

The SEM Scanner is a medical device designed for use by healthcare providers as part of pressure ulcer prevention programs. The objective of this study was to evaluate the inter-rater and inter-device agreement and reliability of the SEM Scanner. Thirty-one (31) volunteers free of pressure ulcers or broken skin at the sternum, sacrum, and heels were assessed with the SEM Scanner. Each of three operators utilized each of three devices to collect readings from four anatomical sites (sternum, sacrum, left and right heels) on each subject for a total of 108 readings per subject collected over approximately 30 min. For each combination of operator-device-anatomical site, three SEM readings were collected. Inter-operator and inter-device agreement and reliability were estimated. Over the course of this study, more than 3000 SEM Scanner readings were collected. Agreement between operators was good with mean differences ranging from -0.01 to 0.11. Inter-operator and inter-device reliability exceeded 0.80 at all anatomical sites assessed. The results of this study demonstrate the high reliability and good agreement of the SEM Scanner across different operators and different devices. Given the limitations of current methods to prevent and detect pressure ulcers, the SEM Scanner shows promise as an objective, reliable tool for assessing the presence or absence of pressure-induced tissue damage such as pressure ulcers. Copyright © 2015 Bruin Biometrics, LLC. Published by Elsevier Ltd.. All rights reserved.

Helium Ion Microscope: A New Tool for Sub-nanometer Imaging of Soft Materials

Science.gov (United States)

Shutthanandan, V.; Arey, B.; Smallwood, C. R.; Evans, J. E.

2017-12-01

High-resolution inspection of surface details is needed in many biological and environmental researches to understand the Soil organic material (SOM)-mineral interactions along with identifying microbial communities and their interactions. SOM shares many imaging characteristics with biological samples and getting true surface details from these materials are challenging since they consist of low atomic number materials. FE-SEM imaging is the main imagining technique used to image these materials in the past. These SEM images often show loss of resolution and increase noise due to beam damage and charging issues. Newly developed Helium Ion Microscope (HIM), on the other hand can overcome these difficulties and give very fine details. HIM is very similar to scanning electron microscopy (SEM) but instead of using electrons as a probe beam, HIM uses helium ions with energy ranges from 5 to 40 keV. HIM offers a series of advantages compared to SEM such as nanometer and sub-nanometer image resolutions (about 0.35 nm), detailed surface topography, high surface sensitivity, low Z material imaging (especially for polymers and biological samples), high image contrast, and large depth of field. In addition, HIM also has the ability to image insulating materials without any conductive coatings so that surface details are not modified. In this presentation, several scientific applications across biology and geochemistry will be presented to highlight the effectiveness of this powerful microscope. Acknowledgements: Research was performed using the Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at PNNL. Work was supported by DOE-BER Mesoscale to Molecules Bioimaging Project FWP# 66382.

Diversity of seM in Streptococcus equi subsp. equi isolated from strangles outbreaks.

Science.gov (United States)

Libardoni, Felipe; Vielmo, Andréia; Farias, Luana; Matter, Letícia Beatriz; Pötter, Luciana; Spilki, Fernando Rosado; de Vargas, Agueda Castagna

2013-03-23

Strangles is the main upper respiratory tract disease of horses. There are currently no studies on the changes in alleles of the M protein gene (seM) in Brazilian isolates of Streptococcus equi ssp. equi (S. equi). This study aimed to analyze and differentiate molecularly S. equi isolates from equine clinical specimens from southern Brazil, between 1994 and 2010. seM alleles were analyzed in 47 isolates of S. equi obtained from clinical cases of strangles (15 Thoroughbred horses, 29 Crioulo breed horses and three Brasileiro de Hipismo--BH). seM alleles characterization was performed by comparing variable region sequences of the seM gene. The alleles were also phylogenetically grouped by Neighbor-joining analysis, which demonstrated the geographic distribution of those in properties from southern Brazil. Fifteen alleles of the gene seM were found among the 47 S. equi isolates analyzed. Among these, only one allele (seM-61), which was identified in seven isolates (14.9%), was found in the database PubMLST-seM. Within the new alleles, allele seM-115 was the most prevalent, having been found in 13 isolates (27.7%), followed by allele seM-117 in 10 isolates (21.3%). In the Brazilian horse population studied, there is greater diversity of M protein alleles in S. equi isolates compared to worldwide data deposited in PubMLST-seM. Among the 15 seM alleles identified, only one allele sequence was previously published. The alleles identification is important to control the disease by guiding selection of strains for the manufacture of commercial and autogenous vaccines. Copyright © 2012 Elsevier B.V. All rights reserved.

Shocked quartz in the SEM: Distinction between amorphous and healed PDFs

NARCIS (Netherlands)

Hamers, M.F.; Pennock, G.M.; Drury, M.R.

2012-01-01

Combined SEM techniques show that different CL signatures of PDFs are related to fresh and healed microstructures of PDFs and host quartz. This is confirmed by TEM results. A combination of SEM techniques can give the same type of information as TEM

The Effectiveness of Self-Expandable Metallic Stent Insertion in Treating Right-Sided Colonic Obstruction: A Comparison between SEMS and Decompression Tube Placement and an Investigation of the Safety and Difficulties of SEMS Insertion in Right Colons

Directory of Open Access Journals (Sweden)

Rintaro Moroi

2014-01-01

Full Text Available Objectives. Self-expandable metallic stent (SEMS is widely used to treat malignant colonic obstruction. However, most reports about SEMS insertion have concentrated on the left colon. This study aimed to (1 investigate the effectiveness of SEMS insertion compared with conventional decompression tube for right-sided colonic obstruction and (2 compare the safety and technical success of SEMS insertion between left- and right-sided colonic obstructions. Methods. The data from thirty-seven patients who underwent SEMS or conventional decompression tube placement for malignant colonic obstruction in our hospital were analyzed retrospectively. Technical and clinical success, complications, and technical difficulties were analyzed. We compared the results between SEMS insertion and decompression tube placement in right colons and the outcomes of SEMS insertion between right- and left-sided colonic obstructions. Results. For right colons, the clinical success rate of SEMS insertion (100% was significantly higher than that of decompression tube placement (55.9%. Concerning SEMS insertion, the technical difficulty and safety of SEMS insertion were similar between right- and left-sided colonic obstructions. Conclusion. SEMS insertion for right-sided colon is significantly more effective than conventional decompression tube placement, and this procedure was safer and less technically challenging than expected. SEMS insertion should be considered for treating right-sided malignant colonic obstruction.

The innovation of cryo-SEM freeze-fracturing methodology demonstrated on high pressure frozen biofilm.

Science.gov (United States)

Hrubanova, Kamila; Nebesarova, Jana; Ruzicka, Filip; Krzyzanek, Vladislav

2018-04-22

In this study we present an innovative method for the preparation of fully hydrated samples of microbial biofilms of cultures Staphylococcus epidermidis, Candida parapsilosis and Candida albicans. Cryo-scanning electron microscopy (cryo-SEM) and high-pressure freezing (HPF) rank among cutting edge techniques in the electron microscopy of hydrated samples such as biofilms. However, the combination of these techniques is not always easily applicable. Therefore, we present a method of combining high-pressure freezing using EM PACT2 (Leica Microsystems), which fixes hydrated samples on small sapphire discs, with a high resolution SEM equipped with the widely used cryo-preparation system ALTO 2500 (Gatan). Using a holder developed in house, a freeze-fracturing technique was applied to image and investigate microbial cultures cultivated on the sapphire discs. In our experiments, we focused on the ultrastructure of the extracellular matrix produced during cultivation and the relationships among microbial cells in the biofilm. The main goal of our investigations was the detailed visualization of areas of the biofilm where the microbial cells adhere to the substrate/surface. We show the feasibility of this technique, which is clearly demonstrated in experiments with various freeze-etching times. Copyright © 2018 Elsevier Ltd. All rights reserved.

La vida de Santo Domingo de Silos: onirocrítica y semántica

Directory of Open Access Journals (Sweden)

González, Javier Roberto

2007-12-01

Full Text Available We study the prophetic vision of Santo Domingo de Silos in Gonzalo de Berceo’s Vida de Santo Domingo de Silos, with the aim of: a analysing the text according to categories of prophecy, vision and dream in medieval christian culture; b analysing the configuration of oniric images as an allegorical discourse; c given the limits of allegorical semantics, interpreting those symbolic images characterized by prophetical obscuritas in the light of Grimaldus’ Vita Beati Dominici, source of Berceo’s Vida, and also in the light of medieval tradition of Other World visions and general chromatic an arithmetical symbolism, in order to establish semantic innovations and the proper meanning of Berceo’s text.Estudiamos la visión profética de Santo Domingo de Silos en la Vida de Santo Domingo de Silos de Gonzalo de Berceo, con el objeto de: a analizar el texto según las categorías de profecía, visión y sueño vigentes en la cultura cristiana medieval; b analizar la configuración de las imágenes oníricas como discurso alegórico; c dados los límites de la semántica alegórica, interpretar aquellas imágenes simbólicas caracterizadas por la obscuritas profética a la luz de la Vita Beati Dominici de Grimaldo, fuente de la Vida de Berceo, y también a la luz de la tradición medieval de las visiones de trasmundo y del simbolismo general cromático y aritmético, en orden al establecimiento de las innovaciones semánticas y con ellas del recto sentido del texto de Berceo.

SemGroup acquisition of central Alberta midstream : case study

International Nuclear Information System (INIS)

Purcell, T.

2005-01-01

A case study of SemGroup's acquisition of Central Alberta Midstream was presented. SemCAMS specializes in providing more efficient supply, storage, and distribution assets and services. Seminole Canada Gas is a leading independent natural gas marketing and energy asset management company that currently markets 369 MMbtu per day. The company purchases natural gas in western Canada for fee-based marketing services while also managing firm transportation contracts and providing gas storage for third party customers. SemCAMS owns the largest sour gas processor in Alberta as well as 3 sour gas processing plants, 600 miles of gathering pipeline, and a sweet gas processing plant. the company is also planning increased drilling and production activities and is now pursuing aggressive land acquisition policies. Over 25,000 square miles of land have been acquired. It was concluded that midstream companies should be customer-focused, provide reliability and guarantees, infrastructure investment and optimization. tabs., figs

In-Situ tensile testing of propellants in SEM: influence of temperature

NARCIS (Netherlands)

Di Benedetto, G.L.; Ramshorst, M.C.J.; Duvalois, W.; Hooijmeijer, P.; Heijden, A. van der

2017-01-01

A tensile module system placed within a Scanning Electron Microscope (SEM) was utilized to conduct insitu tensile testing of propellant samples. The tensile module system allows for real-time in-situ SEM analysis of the samples to determine the failure mechanism of the propellant material under

Mathematical model of the seismic electromagnetic signals (SEMS) in non crystalline substances

Energy Technology Data Exchange (ETDEWEB)

Dennis, L. C. C.; Yahya, N.; Daud, H.; Shafie, A. [Electromagnetic cluster, Universiti Teknologi Petronas, 31750 Tronoh, Perak (Malaysia)

2012-09-26

The mathematical model of seismic electromagnetic waves in non crystalline substances is developed and the solutions are discussed to show the possibility of improving the electromagnetic waves especially the electric field. The shear stress of the medium in fourth order tensor gives the equation of motion. Analytic methods are selected for the solutions written in Hansen vector form. From the simulated SEMS, the frequency of seismic waves has significant effects to the SEMS propagating characteristics. EM waves transform into SEMS or energized seismic waves. Traveling distance increases once the frequency of the seismic waves increases from 100% to 1000%. SEMS with greater seismic frequency will give seismic alike waves but greater energy is embedded by EM waves and hence further distance the waves travel.

Mathematical model of the seismic electromagnetic signals (SEMS) in non crystalline substances

International Nuclear Information System (INIS)

Dennis, L. C. C.; Yahya, N.; Daud, H.; Shafie, A.

2012-01-01

The mathematical model of seismic electromagnetic waves in non crystalline substances is developed and the solutions are discussed to show the possibility of improving the electromagnetic waves especially the electric field. The shear stress of the medium in fourth order tensor gives the equation of motion. Analytic methods are selected for the solutions written in Hansen vector form. From the simulated SEMS, the frequency of seismic waves has significant effects to the SEMS propagating characteristics. EM waves transform into SEMS or energized seismic waves. Traveling distance increases once the frequency of the seismic waves increases from 100% to 1000%. SEMS with greater seismic frequency will give seismic alike waves but greater energy is embedded by EM waves and hence further distance the waves travel.

Real-time scanning charged-particle microscope image composition with correction of drift.

Science.gov (United States)

Cizmar, Petr; Vladár, András E; Postek, Michael T

2011-04-01

In this article, a new scanning electron microscopy (SEM) image composition technique is described, which can significantly reduce drift related image corruptions. Drift distortion commonly causes blur and distortions in the SEM images. Such corruption ordinarily appears when conventional image-acquisition methods, i.e., "slow scan" and "fast scan," are applied. The damage is often very significant; it may render images unusable for metrology applications, especially where subnanometer accuracy is required. The described correction technique works with a large number of quickly taken frames, which are properly aligned and then composed into a single image. Such image contains much less noise than the individual frames, while the blur and deformation is minimized. This technique also provides useful information about changes of the sample position in time, which may be applied to investigate the drift properties of the instrument without a need of additional equipment.

O ciberativismo sem bússola

Directory of Open Access Journals (Sweden)

Francisco Rüdiger

2014-07-01

Full Text Available Questiona-se no texto se uma abordagem que, no essencial, relata a trajetória do chamado ciberativismo de acordo com seus próprios termos se justifica academicamente ou, em vez disso, se mantém prisioneira de uma mitologia que o fenômeno, em si mesmo, já construiu e, por isso, autoriza seus sujeitos a dispensarem sem prejuízo eventual contribuição de origem universitária.

Heavy metal distribution in Suillus luteus mycorrhizas - as revealed by micro-PIXE analysis

Science.gov (United States)

Turnau, K.; Przybyłowicz, W. J.; Mesjasz-Przybyłowicz, J.

2001-07-01

Suillus luteus/Pinus sylvestris mycorrhizas, collected from zinc wastes in Southern Poland, were selected as potential biofilters on the basis of earlier studies carried out with energy dispersive spectrometry (EDS) microanalytical system coupled to scanning electron microscope (SEM) and transmission electron microscope (TEM). Using the National Accelerator Centre (NAC) nuclear microprobe, elemental concentrations in the ectomycorrhiza parts were for the first time estimated quantitatively. Micro-proton-induced X-ray emission (PIXE) true elemental maps from freeze-dried and chemically fixed mycorrhizas revealed strong accumulation of Ca, Fe, Zn and Pb within the fungal mantle and in the rhizomorph. Vascular tissue was enriched with P, S and K, while high concentrations of Si and Cl were present in the endodermis. Cu was the only element showing elevated concentrations in the cortex region. Elemental losses and redistributions were found in mycorrhizas prepared by chemical fixation. Some problems related to elemental imaging are discussed.

Heavy metal distribution in Suillus luteus mycorrhizas - as revealed by micro-PIXE analysis

International Nuclear Information System (INIS)

Turnau, K.; Przybylowicz, W.J.; Mesjasz-Przybylowicz, J.

2001-01-01

Suillus luteus/Pinus sylvestris mycorrhizas, collected from zinc wastes in Southern Poland, were selected as potential biofilters on the basis of earlier studies carried out with energy dispersive spectrometry (EDS) microanalytical system coupled to scanning electron microscope (SEM) and transmission electron microscope (TEM). Using the National Accelerator Centre (NAC) nuclear microprobe, elemental concentrations in the ectomycorrhiza parts were for the first time estimated quantitatively. Micro-proton-induced X-ray emission (PIXE) true elemental maps from freeze-dried and chemically fixed mycorrhizas revealed strong accumulation of Ca, Fe, Zn and Pb within the fungal mantle and in the rhizomorph. Vascular tissue was enriched with P, S and K, while high concentrations of Si and Cl were present in the endodermis. Cu was the only element showing elevated concentrations in the cortex region. Elemental losses and redistributions were found in mycorrhizas prepared by chemical fixation. Some problems related to elemental imaging are discussed

Neuropsicología de la demencia semántica

OpenAIRE

Andrade Quintero, Luz Helena

2012-01-01

La Demencia Semántica causa alteraciones en la capacidad para recordar el significado de las palabras, rostros y objetos, producto de atrofia asimétrica o bilateral de los lóbulos temporales anteriores. Clínicamente se han observado múltiples síndromes clínicos superpuestos con otras enfermedades degenerativas como la Afasia Primaria Progresiva y la Demencia tipo Alzheimer. El propósito de este estudio fue identificar alteraciones lingüísticas y semánticas en un grupo de pacientes con Demenci...

What Determines Lean Manufacturing Implementation? A CB-SEM Model

Directory of Open Access Journals (Sweden)

Tan Ching Ng

2018-02-01

Full Text Available This research aims to ascertain the determinants of effective Lean Manufacturing (LM. In this research, Covariance-based Structural Equation Modeling (CB-SEM analysis will be used in order to analyze the determinants. Through CB-SEM analysis, the significant key determinants can be determined and the direct relationships among determinants can be analyzed. Thus, the findings of this research can act as guidelines for achievement of LM effectiveness, not only providing necessary steps for successful implementation of lean, but also helping lean companies to achieve higher level of lean cost and time savings.

Evaluating Neighborhoods Livability in Nigeria: A Structural Equation Modelling (SEM Approach

Directory of Open Access Journals (Sweden)

Sule Abass Iyanda

2018-01-01

Full Text Available There is a growing concern about city livability around the world and of particular concern is the aspects of the person-environment relationship which encompasses many characteristics suffice to make a place livable. Extant literature provides livability dimensions such as housing unit characteristics, neighborhood facilities, economic vitality and safety environment. These livability dimensions as well as their attributes found in the extant literature have been reported to have high reliability measurement level. Although, various methods have been applied to examine relationships among the variables however structural equation modeling (SEM has been found more holistic as a modeling technique to understand and explain the relationships that may exist among variable measurements. Structural equation modeling simultaneously performs multivariate analysis including multiple regression, path and factor analysis in the cause-effect relationships between latent constructs. Therefore, this study investigates the key factors of livability of planned residential neighborhoods in Minna, Nigeria with the research objectives of – (a to study the livability level of the selected residential neighborhoods, (b to determine the dimensions and indicators which most influence the level of livability in the selected residential neighborhoods, and (c to reliably test the efficacy of structural equation modeling (SEM in the assessment of livability. The methodology adopted in this study includes- Data collection with the aid of structured questionnaire survey administered to the residents of the study area based on stratified random sampling. The data collected was analyzed with the aid of the Statistical Package for Social Sciences (SPSS 22.0 and AMOS 22.0 software for structural equation modeling (a second-order factor. The study revealed that livability as a second-order factor is indicated by economic vitality, safety environment, neighborhood facilities

Body Image of Pakistani Consumers.

OpenAIRE

Tariq Jalees; Ernest C de Run

2014-01-01

This paper examines how media exposure, self-esteem, and religiosity influence body image of Pakistan consumers. The underpinning of this study is based on Social Comparison Theory with two additional variables (religiosity and self-esteem) for understanding understand consumer attitude towards body image. A self-administered questionnaire was used. 193 persons responded at mall intercepts. The Conceptual framework was empirically tested through SEM. A positive relationship between exposure t...

Analysis of microtraces in invasive traumas using SEM/EDS.

Science.gov (United States)

Vermeij, E J; Zoon, P D; Chang, S B C G; Keereweer, I; Pieterman, R; Gerretsen, R R R

2012-01-10

Scanning electron microscopy in combination with energy-dispersive X-ray spectrometry (SEM/EDS) is a proven forensic tool and has been used to analyze several kinds of trace evidence. A forensic application of SEM/EDS is the examination of morphological characteristics of tool marks that tools and instruments leave on bone. The microtraces that are left behind by these tools and instruments on the bone are, however, often ignored or not noticed at all. In this paper we will describe the use of SEM/EDS for the analysis of microtraces in invasive sharp-force, blunt-force and bone-hacking traumas in bone. This research is part of a larger multi-disciplinary approach in which pathologists, forensic anthropologists, toolmark and microtrace experts work together to link observed injuries to a suspected weapon or, in case of an unknown weapon, to indicate a group of objects that could have been used as a weapon. Although there are a few difficulties one have to consider, the method itself is rather simple and straightforward to apply. A sample of dry and clean bone is placed into the SEM sample chamber and brightness and contrast are set such that bone appears grey, metal appears white and organic material appears black. The sample is then searched manually to find relevant features. Once features are found their elemental composition is measured by an energy dispersive X-ray spectrometer (EDS). This method is illustrated using several cases. It is shown that SEM/EDS analysis of microtraces in bone is a valuable tool to get clues about an unknown weapon and can associate a specific weapon with injuries on the basis of appearance and elemental composition. In particular the separate results from the various disciplines are complementary and may be combined to reach a conclusion with a stronger probative value. This is not only useful in the courtroom but above all in criminal investigations when one have to know for what weapon or object to look for. Copyright © 2011

Arjunolic acid: A promising new building block for nanochemistry

Indian Academy of Sciences (India)

E-mail: kgp bgopal@rediffmail.com ... Inverted vials containing the ... Compound 3 formed transparent gels in various alcohols and mixed solvents (table. 1). ... electron microscopy (SEM) after drying in vacuum. The SEM images revealed a.

FIB and MIP: understanding nanoscale porosity in molecularly imprinted polymers via 3D FIB/SEM tomography.

Science.gov (United States)

Neusser, G; Eppler, S; Bowen, J; Allender, C J; Walther, P; Mizaikoff, B; Kranz, C

2017-10-05

We present combined focused ion beam/scanning electron beam (FIB/SEM) tomography as innovative method for differentiating and visualizing the distribution and connectivity of pores within molecularly imprinted polymers (MIPs) and non-imprinted control polymers (NIPs). FIB/SEM tomography is used in cell biology for elucidating three-dimensional structures such as organelles, but has not yet been extensively applied for visualizing the heterogeneity of nanoscopic pore networks, interconnectivity, and tortuosity in polymers. To our best knowledge, the present study is the first application of this strategy for analyzing the nanoscale porosity of MIPs. MIPs imprinted for propranolol - and the corresponding NIPs - were investigated establishing FIB/SEM tomography as a viable future strategy complementing conventional isotherm studies. For visualizing and understanding the properties of pore networks in detail, polymer particles were stained with osmium tetroxide (OsO 4 ) vapor, and embedded in epoxy resin. Staining with OsO 4 provides excellent contrast during high-resolution SEM imaging. After optimizing the threshold to discriminate between the stained polymer matrix, and pores filled with epoxy resin, a 3D model of the sampled volume may be established for deriving not only the pore volume and pore surface area, but also to visualize the interconnectivity and tortuosity of the pores within the sampled polymer volume. Detailed studies using different types of cross-linkers and the effect of hydrolysis on the resulting polymer properties have been investigated. In comparison of MIP and NIP, it could be unambiguously shown that the interconnectivity of the visualized pores in MIPs is significantly higher vs. the non-imprinted polymer, and that the pore volume and pore area is 34% and approx. 35% higher within the MIP matrix. This confirms that the templating process not only induces selective binding sites, but indeed also affects the physical properties of such

A simple method for detection of gunshot residue particles from hands, hair, face, and clothing using scanning electron microscopy/wavelength dispersive X-ray (SEM/WDX).

Science.gov (United States)

Kage, S; Kudo, K; Kaizoji, A; Ryumoto, J; Ikeda, H; Ikeda, N

2001-07-01

We devised a simple and rapid method for detection of gunshot residue (GSR) particles, using scanning electron microscopy/wavelength dispersive X-ray (SEM/WDX) analysis. Experiments were done on samples containing GSR particles obtained from hands, hair, face, and clothing, using double-sided adhesive coated aluminum stubs (tape-lift method). SEM/WDX analyses for GSR were carried out in three steps: the first step was map analysis for barium (Ba) to search for GSR particles from lead styphnate primed ammunition, or tin (Sn) to search for GSR particles from mercury fulminate primed ammunition. The second step was determination of the location of GSR particles by X-ray imaging of Ba or Sn at a magnification of x 1000-2000 in the SEM, using data of map analysis, and the third step was identification of GSR particles, using WDX spectrometers. Analysis of samples from each primer of a stub took about 3 h. Practical applications were shown for utility of this method.

Does Sexually Explicit Media (SEM) Affect Me?

DEFF Research Database (Denmark)

Hald, Gert Martin; Træen, Bente; Noor, Syed W

2015-01-01

and understanding of one’s sexual orientation.First-person effects refer to self-perceived and self-reported effects of SEM consumptionas experienced by the consumer. In addition, the study examined and provided athorough validation of the psychometric properties of the seven-item PornographyConsumption Effect...

Hematite/silver nanoparticle bilayers on mica--AFM, SEM and streaming potential studies.

Science.gov (United States)

Morga, Maria; Adamczyk, Zbigniew; Oćwieja, Magdalena; Bielańska, Elżbieta

2014-06-15

Bilayers of hematite/silver nanoparticles were obtained in the self-assembly process and thoroughly characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM), and in situ streaming potential measurements. The hematite nanoparticles, forming a supporting layer, were 22 nm in diameter, exhibiting an isoelectric point at pH 8.9. The silver nanoparticles, used to obtain an external layer, were 29 nm in diameter, and remained negative within the pH range 3 to 11. In order to investigate the particle deposition, mica sheets were used as a model solid substrate. The coverage of the supporting layer was adjusted by changing the bulk concentration of the hematite suspension and the deposition time. Afterward, silver nanoparticle monolayers of controlled coverage were deposited under the diffusion-controlled transport. The coverage of bilayers was determined by a direct enumeration of deposited particles from SEM micrographs and AFM images. Additionally, the formation of the hematite/silver bilayers was investigated by streaming potential measurements carried out under in situ conditions. The effect of the mica substrate and the coverage of a supporting layer on the zeta potential of bilayers was systematically studied. It was established that for the coverage exceeding 0.20, the zeta potential of bilayers was independent on the substrate and the supporting layer coverage. This behavior was theoretically interpreted in terms of the 3D electrokinetic model. Beside significance for basic sciences, these measurements allowed to develop a robust method of preparing nanoparticle bilayers of controlled properties, having potential applications in catalytic processes. Copyright © 2014 Elsevier Inc. All rights reserved.

International Conference on SEMS 2012

CERN Document Server

Liu, Chuang; Scientific explanation and methodology of science; SEMS 2012

2014-01-01

This volume contains the contributed papers of invitees to SEMS 2012 who have also given talks at the conference. The invitees are experts in philosophy of science and technology from Asia (besides China), Australia, Europe, Latin America, North America, as well as from within China. The papers in this volume represent the latest work of each researcher in his or her expertise; and as a result, they give a good representation of the cutting-edge researches in diverse areas in different parts of the world.

Protons, ions, electrons and the future of the SEM

International Nuclear Information System (INIS)

Joy, D C

2010-01-01

The Scanning Electron Microscope (SEM) is the most widely used high performance microscope in all fields of science but it is now reaching the theoretical limits of its performance. While advances in sources, optics, and detectors, can result in some improvement in performance the ultimate resolution is limited by fundamental physical constraints. One potential alternative is a scanning microscope utilizing light ions such as H+ and He+ . Such an instrument shares all of the benefits of the conventional SEM but is free from the constraints encountered when using electrons and could significantly extend the scope and success of scanning microscopy.

A practical approach to test the scope of FIB-SEM 3D reconstruction

International Nuclear Information System (INIS)

Ritter, M; Midgley, P A

2010-01-01

State-of-the-art focused ion beam (FIB) instruments have an ion column for sample modification and an electron column for scanning electron microscopy (SEM). 3D reconstruction of a sample volume can be achieved by serial sectioning using the FIB in combination with high-resolution SEM imaging of each cross-section. Usually, the resolution in the direction in which the sections are milled (z-direction) is much lower than in the plane of the cross-section (xy-direction) itself. Increased sampling in the z-direction can only be achieved by decreasing the distance between single sections. For a constant volume this is equivalent to increasing the number of sections, i.e. time and effort. To perform efficient 3D reconstructions the effect of the reduced sampling in the z-direction to the overall accuracy of the 3D reconstruction has to be known. We tested this approach with FIB conical test structures that were slice-and-view processed and subsequently reconstructed. Using a reference data set with a slice thickness (z-resolution) of 22 nm, data with z-resolutions ranging from 44 nm to 440 nm were created and reconstructed with commercial software. The calculated volumes for the simulated z-resolutions and their deviations from the reference volume are shown. Deviations of up to 35% occur and reach about 10% once the z-resolution was one fifth of the upper diameter of the conical structures.

Anti-cancer agents in Saudi Arabian herbals revealed by automated high-content imaging

KAUST Repository

Hajjar, Dina

2017-06-13

Natural products have been used for medical applications since ancient times. Commonly, natural products are structurally complex chemical compounds that efficiently interact with their biological targets, making them useful drug candidates in cancer therapy. Here, we used cell-based phenotypic profiling and image-based high-content screening to study the mode of action and potential cellular targets of plants historically used in Saudi Arabia\\'s traditional medicine. We compared the cytological profiles of fractions taken from Juniperus phoenicea (Arar), Anastatica hierochuntica (Kaff Maryam), and Citrullus colocynthis (Hanzal) with a set of reference compounds with established modes of action. Cluster analyses of the cytological profiles of the tested compounds suggested that these plants contain possible topoisomerase inhibitors that could be effective in cancer treatment. Using histone H2AX phosphorylation as a marker for DNA damage, we discovered that some of the compounds induced double-strand DNA breaks. Furthermore, chemical analysis of the active fraction isolated from Juniperus phoenicea revealed possible anti-cancer compounds. Our results demonstrate the usefulness of cell-based phenotypic screening of natural products to reveal their biological activities.

Jet Power and Black Hole Assortment Revealed in New Chandra Image

Science.gov (United States)

2008-01-01

A dramatic new Chandra image of the nearby galaxy Centaurus A provides one of the best views to date of the effects of an active supermassive black hole. Opposing jets of high-energy particles can be seen extending to the outer reaches of the galaxy, and numerous smaller black holes in binary star systems are also visible. The image was made from an ultra-deep look at the galaxy Centaurus A, equivalent to more than seven days of continuous observations. Centaurus A is the nearest galaxy to Earth that contains a supermassive black hole actively powering a jet. X-ray Image of Centaurus A, Labeled X-ray Image of Centaurus A, Labeled A prominent X-ray jet extending for 13,000 light years points to the upper left in the image, with a shorter "counterjet" aimed in the opposite direction. Astronomers think that such jets are important vehicles for transporting energy from the black hole to the much larger dimensions of a galaxy, and affecting the rate at which stars form there. High-energy electrons spiraling around magnetic field lines produce the X-ray emission from the jet and counterjet. This emission quickly saps the energy from the electrons, so they must be continually reaccelerated or the X-rays will fade out. Knot-like features in the jets detected in the Chandra image show where the acceleration of particles to high energies is currently occurring, and provides important clues to understanding the process that accelerates the electrons to near-light speeds. People Who Read This Also Read... NASA’s Swift Satellite Catches First Supernova in The Act of Exploding Black Holes Have Simple Feeding Habits Chandra Data Reveal Rapidly Whirling Black Holes Erratic Black Hole Regulates Itself The inner part of the X-ray jet close to the black hole is dominated by these knots of X-ray emission, which probably come from shock waves -- akin to sonic booms -- caused by the jet. Farther from the black hole there is more diffuse X-ray emission in the jet. The cause of particle

Vocal Tract Images Reveal Neural Representations of Sensorimotor Transformation During Speech Imitation

Science.gov (United States)

Carey, Daniel; Miquel, Marc E.; Evans, Bronwen G.; Adank, Patti; McGettigan, Carolyn

2017-01-01

Abstract Imitating speech necessitates the transformation from sensory targets to vocal tract motor output, yet little is known about the representational basis of this process in the human brain. Here, we address this question by using real-time MR imaging (rtMRI) of the vocal tract and functional MRI (fMRI) of the brain in a speech imitation paradigm. Participants trained on imitating a native vowel and a similar nonnative vowel that required lip rounding. Later, participants imitated these vowels and an untrained vowel pair during separate fMRI and rtMRI runs. Univariate fMRI analyses revealed that regions including left inferior frontal gyrus were more active during sensorimotor transformation (ST) and production of nonnative vowels, compared with native vowels; further, ST for nonnative vowels activated somatomotor cortex bilaterally, compared with ST of native vowels. Using test representational similarity analysis (RSA) models constructed from participants’ vocal tract images and from stimulus formant distances, we found that RSA searchlight analyses of fMRI data showed either type of model could be represented in somatomotor, temporal, cerebellar, and hippocampal neural activation patterns during ST. We thus provide the first evidence of widespread and robust cortical and subcortical neural representation of vocal tract and/or formant parameters, during prearticulatory ST. PMID:28334401

In-line CD metrology with combined use of scatterometry and CD-SEM

Science.gov (United States)

Asano, Masafumi; Ikeda, Takahiro; Koike, Toru; Abe, Hideaki

2006-03-01

Measurement characteristics in scatterometry and CD-SEM for lot acceptance sampling of inline critical dimension (CD) metrology were investigated by using a statistical approach with Monte Carlo simulation. By operation characteristics curve analysis, producer's risk and consumer's risk arising from sampling were clarified. Single use of scatterometry involves a higher risk, such risk being particularly acute in the case of large intra-chip CD variation because it is unable to sufficiently monitor intra-chip CD variation including local CD error. Substituting scatterometry for conventional SEM metrology is accompanied with risks, resulting in the increase of unnecessary cost. The combined use of scatterometry and SEM metrology in which the sampling plan for SEM is controlled by scatterometry is a promising metrology from the viewpoint of the suppression of risks and cost. This is due to the effect that CD errors existing in the distribution tails are efficiently caught.

Biofilm growth program and architecture revealed by single-cell live imaging

Science.gov (United States)

Yan, Jing; Sabass, Benedikt; Stone, Howard; Wingreen, Ned; Bassler, Bonnie

Biofilms are surface-associated bacterial communities. Little is known about biofilm structure at the level of individual cells. We image living, growing Vibrio cholerae biofilms from founder cells to ten thousand cells at single-cell resolution, and discover the forces underpinning the architectural evolution of the biofilm. Mutagenesis, matrix labeling, and simulations demonstrate that surface-adhesion-mediated compression causes V. cholerae biofilms to transition from a two-dimensional branched morphology to a dense, ordered three-dimensional cluster. We discover that directional proliferation of rod-shaped bacteria plays a dominant role in shaping the biofilm architecture, and this growth pattern is controlled by a single gene. Competition analyses reveal the advantages of the dense growth mode in providing the biofilm with superior mechanical properties. We will further present continuum theory to model the three-dimensional growth of biofilms at the solid-liquid interface as well as solid-air interface.

Automated Axis Alignment for a Nanomanipulator inside SEM and Its Error Optimization

Directory of Open Access Journals (Sweden)

Chao Zhou

2017-01-01

Full Text Available In the motion of probing nanostructures, repeating position and movement is frequently happing and tolerance for position error is stringent. The consistency between the axis of manipulators and image is very significant since the visual servo is the most important tool in the automated manipulation. This paper proposed an automated axis alignment method for a nanomanipulator inside the SEM by recognizing the position of a closed-loop controlling the end-effector, which can characterize the relationship of these two axes, and then the rotation matrix can be calculated accordingly. The error of this method and its transfer function are also calculated to compare the iteration method and average method. The method in this paper can accelerate the process of axis alignment to avoid the electron beam induced deposition effect on the end tips. Experiment demonstration shows that it can achieve a 0.1-degree precision in 90 seconds.

Accretion and Preservation of Organic Matter in Carbonaceous Chondrites as Revealed by NanoSIMS Imaging.

Science.gov (United States)

Remusat, L.; Guan, Y.; Eiler, J.

2008-12-01

Carbonaceous chondrites are the most primitive known meteorites. Their parent bodies accreted several discrete components of the early solar system: CAIs, other silicates, oxides, sulfides, ice, organics, and noble gases. Radioactive decay of short live radionucleides quickly heated these parent bodies and drove thermal metamorphism and aqueous alteration of their constituents. Despite this post-acretionary modification, at least some components of the organic matter in the carbaceous chondrites retained distinctive isotopic and molecular properties that may relate to their pre-acretionary origins in the protosolar nebula or in the molecular cloud that gave birth to it [1]. These processes that gave rise to early solar-system organic matter and the extent to which it was modified by parent body processes are still a matter of debate [2]. We have acquired NanoSIMS images of matrices of several CI, CM, CR and CV chondrites to document, in- situ, the distribution of organics and their textural and chemical relationships to co-existing inorganic components. Importantly, we performed these analyses on essentially unmodified fragments of matrix material pressed into indium, rather than on extracts, which have been the focus of most previous work on meteoritic organic matter. Specifically, we simultaneously collected H, D, 12C, 18O, 26CN, 28Si and 32S with a spatial resolution of 200 nm. Inorganic constituents of the imaged domains were determined by SEM imaging and EDS analysis. We identify two textural classes of organic constituents: diffuse organic matter and organic particles ~ 1 micron in diameter. The particles are common and do not exhibit any textural association with any inorganic matrix constituent. This distribution is consistent with previous observations by fluorescence optical microscopy [3]. These organic particles are likely primarily composed of insoluble organic matter (IOM) that grew prior to accretion as pure organic particules and was preserved in

Imaging mass spectrometry and genome mining reveal highly antifungal virulence factor of mushroom soft rot pathogen.

Science.gov (United States)

Graupner, Katharina; Scherlach, Kirstin; Bretschneider, Tom; Lackner, Gerald; Roth, Martin; Gross, Harald; Hertweck, Christian

2012-12-21

Caught in the act: imaging mass spectrometry of a button mushroom infected with the soft rot pathogen Janthinobacterium agaricidamnosum in conjunction with genome mining revealed jagaricin as a highly antifungal virulence factor that is not produced under standard cultivation conditions. The structure of jagaricin was rigorously elucidated by a combination of physicochemical analyses, chemical derivatization, and bioinformatics. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chemical and structural analysis of the bone-implant interface by TOF-SIMS, SEM, FIB and TEM: Experimental study in animal

International Nuclear Information System (INIS)

Palmquist, Anders; Emanuelsson, Lena; Sjövall, Peter

2012-01-01

Although bone-anchored implants are widely used in reconstructive medicine, the mechanism of osseointegration is still not fully understood. Novel analytical tools are needed to further understand this process, where both the chemical and structural aspects of the bone-implant interface are important. The aim of this study was to evaluate the advantages of combining time-of-flight secondary ion mass spectroscopy (TOF-SIMS) with optical (LM), scanning (SEM) and transmission electron microscopy (TEM) techniques for studying the bone-implant interface of bone-anchored implants. Laser-modified titanium implants with surrounded bone retrieved after 8 weeks healing in rabbit were dehydrated and resin embedded. Three types of sample preparation were studied to evaluate the information gained by combining TOF-SIMS, SEM, FIB and TEM. The results show that imaging TOF-SIMS can provide detailed chemical information, which in combination with structural information from microscopy methods provide a more complete characterization of anatomical structures at the bone-implant interface. By investigating various sample preparation techniques, it is shown that grinded cross section samples can be used for chemical imaging using TOF-SIMS, if careful consideration of potential preparation artifacts is taken into account. TOF-SIMS analysis of FIB-prepared bone/implant cross section samples show distinct areas corresponding to bone tissue and implant with a sharp interface, although without chemical information about the organic components.

Hacia una visión generativista de la semántica lexical

Directory of Open Access Journals (Sweden)

Morales A. Bernardo

1992-06-01

Full Text Available

Uno de los objetivos de la teoría semántica de una lengua natural es dar información satisfactoria sobre el significado de las formas lingüísticas. Consideramos que de éstas, las de mayor  importancia significativa son la palabra, la oración y el texto. La palabra, porque en virtud de su compleja estructura semántica y psicológica funciona como el principal medio para la abstracción y conformación de los conceptos destinados para la comunicación; la oración, porque es la unidad de la lengua viva que expresa relaciones de conceptos; el texto, porque es la explicitación del pensamiento en la interacción humana. Las semánticas lexical, oracional y textual son los tres grandes capítulos de la semántica lingüística.

UV imaging reveals facial areas that are prone to skin cancer are disproportionately missed during sunscreen application.

Directory of Open Access Journals (Sweden)

Harry Pratt

Full Text Available Application of sunscreen is a widely used mechanism for protecting skin from the harmful effects of UV light. However, protection can only be achieved through effective application, and areas that are routinely missed are likely at increased risk of UV damage. Here we sought to determine if specific areas of the face are missed during routine sunscreen application, and whether provision of public health information is sufficient to improve coverage. To investigate this, 57 participants were imaged with a UV sensitive camera before and after sunscreen application: first visit; minimal pre-instruction, second visit; provided with a public health information statement. Images were scored using a custom automated image analysis process designed to identify areas of high UV reflectance, i.e. missed during sunscreen application, and analysed for 5% significance. Analyses revealed eyelid and periorbital regions to be disproportionately missed during routine sunscreen application (median 14% missed in eyelid region vs 7% in rest of face, p<0.01. Provision of health information caused a significant improvement in coverage to eyelid areas in general however, the medial canthal area was still frequently missed. These data reveal that a public health announcement-type intervention could be effective at improving coverage of high risk areas of the face, however high risk areas are likely to remain unprotected therefore other mechanisms of sun protection should be widely promoted such as UV blocking sunglasses.

Larva of Glyptotendipes (Glyptotendipes) glaucus (Meigen 1818) (Chironomidae, Diptera)-morphology by Scanning Electron Microscope (SEM), karyotype, and biology in laboratory conditions.

Science.gov (United States)

Kownacki, Andrzej; Woznicka, Olga; Szarek-Gwiazda, Ewa; Michailova, Paraskeva

2016-09-21

Larvae belonging to the family Chironomidae are difficult to identify. The aim of the present study was to describe the larval morphology of G. (G.) glaucus with the aid of a Scanning Electron Microscope (SEM), the karyotype and biology based on materials obtained from laboratory culture. Describing the morphology of larvae, special attention was paid to rarely or never described structures like the maxilla (lacinia and maxillary palp), the long plate situated below the ventromental plate, and plate X situated between lacinia and mentum. The use of SEM allowed also to obtain better images of labrum and ventromental plate. Morphological features of this species have been supplemented by karyotype and biology of larvae in laboratory conditions. Under controlled experimental conditions we found non-synchronous development of G. (G.) glaucus larvae hatched from one egg mass reflected in different lengths of larvae and emerged imagoes.

Photocatalytic properties of KBiO3 and LiBiO3 with tunnel structures

Indian Academy of Sciences (India)

ning Electron Microscopy (SEM), BET surface area analysis and Diffuse Reflectance Spectroscopy (DRS). The. XRD patterns ... The SEM images reveal micron size polyhedral shaped ... based compounds such as BiVO4, Bi2WO6, Bi2MoO6,.

Site specific SEM/FIB/TEM for analysis of lubricated sliding wear of aluminium alloy composites

International Nuclear Information System (INIS)

Walker, J C; Jones, H; Rainforth, W M

2006-01-01

Although extensive research has been undertaken into the dry sliding wear of aluminium alloys, only limited work has been reported on lubricated wear. In this paper, the lubricated sliding wear of some powder derived aluminium alloy composites is reported. Stereo pairs of the worn surface were obtained in the SEM and digitally reconstructed to give an accurate projection of the surface topography. Analysis of the average surface roughness (R a ) along chosen sections provided quantitative information about the wear mechanism. Following this, dual beam focused ion beam (FIB) was undertaken to further explore the features revealed by the SEM surface reconstructions, with TEM sections removed from selected regions. Surface deformation was confined to a narrow layer, typically 1μm thick. Subgrain size within the subsurface layer was comparable to that found in dry sliding wear tests. Reinforcement fracture occurred in the surface particles only. The resultant fragments were often incorporated back into the surface following detachment, such that the total volume fraction reinforcement at the surface was greater than in the bulk. Thus, the dynamic surface topography was a result of three factors: surface deformation, local detachment of reinforcement and re-incorporation of the fragments back into the surface

Three-dimensional characterization of ODS ferritic steel using by FIB-SEM serial sectioning method.

Science.gov (United States)

Endo, T; Sugino, Y; Ohono, N; Ukai, S; Miyazaki, N; Wang, Y; Ohnuki, S

2014-11-01

Considerable attention has been paid to the research of the electron tomography due to determine the three-dimensional (3D) structure of materials [1]. One of the electron tomography techniques, focused ion beam/scanning electron microscopy (FIB-SEM) imaging has advantages of high resolutions (10 nm), large area observation (μm order) and simultaneous energy dispersive x- ray microanalysis (EDS)/ electron backscatter diffraction (EBSD) analysis. The purpose of this study, three-dimensional EBSD analysis of ODS ferritic steel which carried out cold work using FIB-SEM equipment was conducted, and it aimed at analyzing the microstructure obtained there. The zone annealing tests were conducted for ferritic steel [2,3], which were produced through mechanical alloying and hot-extrusion. After zone annealing, specimens were mechanically polished with #400∼4000 emery paper, 1 µm diamond paste and alumina colloidal silica. The serial sectioning and the 3D-electron backscattering diffraction (3D-EBSD) analysis were carried out. We made the micro pillar (30 x 30 x 15 µm). The EBSD measurements were carried out in each layer after serial sectioning at a step size and milling depth was 80 nm with 30 slices. After EBSD analysis, the series of cross-sectional images were aligned according to arbitrarily specified areas and then stacked up to form a volume. Consequently, we obtained the 3D-IPF maps for ODS ferritic steel. In this specimen, the {111} and {001} grains are layered by turns. In addition, the volume fraction value of both plane are similar. The aspect ratio increases with specimen depth. The 3D-EBSD mapping is useful to analysis of the bulk material since this method obtain many microstructure information, such a shape, volume and orientation of the crystal, grain boundary. © The Author 2014. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Multi-scale imaging and elastic simulation of carbonates

Science.gov (United States)

Faisal, Titly Farhana; Awedalkarim, Ahmed; Jouini, Mohamed Soufiane; Jouiad, Mustapha; Chevalier, Sylvie; Sassi, Mohamed

2016-05-01

Digital Rock Physics (DRP) is an emerging technology that can be used to generate high quality, fast and cost effective special core analysis (SCAL) properties compared to conventional experimental techniques and modeling techniques. The primary workflow of DRP conssits of three elements: 1) image the rock sample using high resolution 3D scanning techniques (e.g. micro CT, FIB/SEM), 2) process and digitize the images by segmenting the pore and matrix phases 3) simulate the desired physical properties of the rocks such as elastic moduli and velocities of wave propagation. A Finite Element Method based algorithm, that discretizes the basic Hooke's Law equation of linear elasticity and solves it numerically using a fast conjugate gradient solver, developed by Garboczi and Day [1] is used for mechanical and elastic property simulations. This elastic algorithm works directly on the digital images by treating each pixel as an element. The images are assumed to have periodic constant-strain boundary condition. The bulk and shear moduli of the different phases are required inputs. For standard 1.5" diameter cores however the Micro-CT scanning reoslution (around 40 μm) does not reveal smaller micro- and nano- pores beyond the resolution. This results in an unresolved "microporous" phase, the moduli of which is uncertain. Knackstedt et al. [2] assigned effective elastic moduli to the microporous phase based on self-consistent theory (which gives good estimation of velocities for well cemented granular media). Jouini et al. [3] segmented the core plug CT scan image into three phases and assumed that micro porous phase is represented by a sub-extracted micro plug (which too was scanned using Micro-CT). Currently the elastic numerical simulations based on CT-images alone largely overpredict the bulk, shear and Young's modulus when compared to laboratory acoustic tests of the same rocks. For greater accuracy of numerical simulation prediction, better estimates of moduli inputs

3D imaging using X-Ray tomography and SEM combined FIB to study non isothermal creep damage of (111) oriented samples of γ / γ ′ nickel base single crystal superalloy MC2

KAUST Repository

Jouiad, Mustapha

2012-01-01

An unprecedented investigation consisting of the association of X-Ray tomography and Scanning Electron Microscopy combined with Focus Ion Beam (SEM-FIB) is conducted to perform a 3D reconstruction imaging. These techniques are applied to study the non-isothermal creep behavior of close (111) oriented samples of MC2 nickel base superalloys single crystal. The issue here is to develop a strategy to come out with the 3D rafting of γ\\' particles and its interaction whether with dislocation structures or/and with the preexisting voids. This characterization is uncommonly performed away from the conventional studied orientation [001] in order to feed the viscoplastic modeling leading to its improvement by taking into account the crystal anisotropy. The creep tests were performed at two different conditions: classical isothermal tests at 1050°C under 140 MPa and a non isothermal creep test consisting of one overheating at 1200°C and 30 seconds dwell time during the isothermal creep life. The X-Ray tomography shows a great deformation heterogeneity that is pronounced for the non-isothermal tested samples. This deformation localization seems to be linked to the preexisting voids. Nevertheless, for both tested samples, the voids coalescence is the precursor of the observed damage leading to failure. SEM-FIB investigation by means of slice and view technique gives 3D views of the rafted γ\\' particles and shows that γ corridors evolution seems to be the main creep rate controlling parameter. © 2012 Trans Tech Publications, Switzerland.

Multi-scale characteristics of coal structure by x-ray computed tomography (x-ray CT), scanning electron microscope (SEM) and mercury intrusion porosimetry (MIP)

Science.gov (United States)

Cai, Ting-ting; Feng, Zeng-chao; Zhou, Dong

2018-02-01

It is of great benefit to study the material and structural heterogeneity of coal for better understanding the coalbed methane (CBM) storage and enrichment. In this paper, multi-scale X-ray computed tomography (CT), scanning electron microscope (SEM) and mercury intrusion porosimetry (MIP) at multi scales were conducted to thoroughly study the material distribution, heterogeneity, pore development, porosity and permeability of coal. It is suitable and reasonable to divide the testing samples into three structural categories by average density and heterogeneity degree, and the meso structure in the three categories accords with the morphology on SEM images. The pore size distribution and pore development of each subsample cannot be correspondingly related to their respective structure category or morphology due to different observation scales, while the macro pore size development, accumulated macro pore volume and macro pores porosity accord with the meso structure category and morphology information by CT and SEM at the same scale very well. Given the effect of macro pores on permeability and the contribution of micro pores to CBM storage capacity, reservoirs with developed micro pores and macro pores may be the most suitable coal reservoir for CBM exploitation.

SEM: A user's manual for materials science

International Nuclear Information System (INIS)

Gabriel, B.L.

1985-01-01

This book provides a reference of techniques used by the metallurgical microscopist. It contains an introduction to the instrumentation and methods of scanning electron microscopy with historical as well as state-of-the-art methodologies. Topics covered include: SEM instrumentation, photography, energy dispersive spectroscopy, introduction to sample preparation, polished samples, fracture surfaces, replicas and thin films

The SEM description of interaction of a transient electromagnetic wave with an object

Science.gov (United States)

Pearson, L. W.; Wilton, D. R.

1980-01-01

The singularity expansion method (SEM), proposed as a means for determining and representing the transient surface current density induced on a scatterer by a transient electromagnetic wave is described. The resulting mathematical description of the transient surface current on the object is discussed. The data required to represent the electromagnetic scattering properties of a given object are examined. Experimental methods which were developed for the determination of the SEM description are discussed. The feasibility of characterizing the surface current induced on aircraft flying in proximity to a lightning stroke by way of SEM is examined.

Assessing Actual Visit Behavior through Antecedents of Tourists Satisfaction among International Tourists in Jordan: A Structural Equation Modeling (SEM Approach

Directory of Open Access Journals (Sweden)

Ayed Moh’d Al Muala

2011-06-01

Full Text Available Jordan tourism industry is facing fluctuating tourist visit provoked by dissatisfaction, high visit risk, low hotel service, or negative Jordan image. This study aims to examine the relationships between the antecedents of tourist satisfaction and actual visit behavior in tourism of Jordan, and the mediating effect of tourist satisfaction (SAT in the relationship between Jordan image (JOM, service climate (SER and actual visit behavior (ACT. A total of 850 international tourists completed a survey that were conducted at southern sites in Jordan. Using structural equation modeling (SEM technique, confirmatory Factor Analysis (CFA was performed to examine the reliability and validity of the measurement, and the structural equation modeling techniques (Amos 6.0 were used to evaluate the casual model. Results of the study demonstrate the strong predictive power and explain of international tourists’ behavior in Jordan. The findings highlighted that the relationship between Jordan image and service climate are significant and positive on actual visit behavior.

A photomultiplier-based secondary electron imaging system for a nuclear microprobe

International Nuclear Information System (INIS)

Alves, L.C.; Breese, M.B.H.; Silva, M.F. da; Soares, J.C.

2002-01-01

The ability to define, or recognise particular regions of interest or surface features is vital to the analysis and interpretation of spatially-resolved images collected with a nuclear microprobe. However, good topographic image contrast is difficult to accomplish using PIXE or RBS images due to their inherent insensitivity to topography, lack of elemental variation or poor statistics. Topographic image contrast is commonly obtained in scanning electron microscopy (SEM) by detecting a large flux of secondary electrons produced by the focused keV electron beam. Similar systems have not been widely used on nuclear microprobes due to ion beam intensity fluctuations, which limit the minimum resolvable contrast and present a major limitation for this technique. This paper describes a secondary electron imaging system which has been developed on the Lisbon microprobe. It is based on a scintillator, a photomultiplier operated in a pulsed mode, a pulse shaping electronic chain and ADC, and requires no changes to the existing data acquisition system. Examples of the images obtained from materials such as patterned SiGe wafers and hydrogen-implanted silicon are given, and compared with SEM or optical images

Cloud top structure of Venus revealed by Subaru/COMICS mid-infrared images

Science.gov (United States)

Sato, T. M.; Sagawa, H.; Kouyama, T.; Mitsuyama, K.; Satoh, T.; Ohtsuki, S.; Ueno, M.; Kasaba, Y.; Nakamura, M.; Imamura, T.

2014-11-01

We have investigated the cloud top structure of Venus by analyzing ground-based images taken at the mid-infrared wavelengths of 8.66 μm and 11.34 μm. Venus at a solar phase angle of ∼90°, with the morning terminator in view, was observed by the Cooled Mid-Infrared Camera and Spectrometer (COMICS), mounted on the 8.2-m Subaru Telescope, during the period October 25-29, 2007. The disk-averaged brightness temperatures for the observation period are ∼230 K and ∼238 K at 8.66 μm and 11.34 μm, respectively. The obtained images with good signal-to-noise ratio and with high spatial resolution (∼200 km at the sub-observer point) provide several important findings. First, we present observational evidence, for the first time, of the possibility that the westward rotation of the polar features (the hot polar spots and the surrounding cold collars) is synchronized between the northern and southern hemispheres. Second, after high-pass filtering, the images reveal that streaks and mottled and patchy patterns are distributed over the entire disk, with typical amplitudes of ∼0.5 K, and vary from day to day. The detected features, some of which are similar to those seen in past UV images, result from inhomogeneities of both the temperature and the cloud top altitude. Third, the equatorial center-to-limb variations of brightness temperatures have a systematic day-night asymmetry, except those on October 25, that the dayside brightness temperatures are higher than the nightside brightness temperatures by 0-4 K under the same viewing geometry. Such asymmetry would be caused by the propagation of the migrating semidiurnal tide. Finally, by applying the lapse rates deduced from previous studies, we demonstrate that the equatorial center-to-limb curves in the two spectral channels give access to two parameters: the cloud scale height H and the cloud top altitude zc. The acceptable models for data on October 25 are obtained at H = 2.4-4.3 km and zc = 66-69 km; this supports

PAT and SEM study of porous silicon formed by anodization methods

International Nuclear Information System (INIS)

Liu Jian; Wei Long; Wang Huiyao; Ma Chuangxin; Wang Baoyi

2000-01-01

The porous silicon formed by anodization of crystal silicon was studied by positron annihilation technique (PAT) and scanning electron microscopy (SEM). The PAT experiments showed that the mean life and vacancy defects increased with the increasing anodization time. While the intensities of the longest lifetime, several ns-tens ns (ortho-positronium) dropped down. Small single-crystal Si spheres with mean radius of a few μm were observed by SEM after anodization. Pits with mean radius of a few μm from the divorcement of single-crystal spheres were also observed after further anodization. The increases of vacancy defects might be that the extension of structures of porous silicon towards inner layer with anodization time and caused more vacancy defects in inner layer. The SEM observation presented another possibility of the increase of density of vacancy defects in surface layer induced by the change of structures

Inconmensurabilidad semántica y progreso científico

Directory of Open Access Journals (Sweden)

Vázquez, Juan

1997-08-01

Full Text Available Not available.En la primera parte del trabajo se hace una presentación de las nociones de «inconmensurabilidad», tal como han sido formuladas por Feyerabend y Kuhn; y en la segunda parte, después de analizar los presupuestos semánticos con los que indudablemente han ido asociadas, se presenta un modelo alternativo de análisis semántico de la ‘inconmensurabilidad’, que permite desligarla de las nociones de «incomunicabilidad» e «incomparabilidad» interteóricas. Con ese propósito se hace uso de una doble noción de objeto formulada por C. S. Peirce, en sus Collected Papers, y por E. Husserl, en el parágrafo 131 de las Ideas.

FIB/SEM study of AA2024 corrosion under a seawater drop, part II

International Nuclear Information System (INIS)

King, Peter C.; Cole, Ivan S.; Corrigan, Penny A.; Hughes, Anthony E.; Muster, Tim H.; Thomas, Sebastian

2012-01-01

Highlights: ► Dealloying has a directional nature, exhibits banding. ► Oxidation state of copper in sponge remnants found to be variable. ► Dissolution and breakdown of copper sponge structure observed. ► Crystalline defects imaged in dealloyed S-phase. - Abstract: The dissolution of S-phase clusters in aluminium alloy 2024 (AA2024) exposed to a 0.5 μl seawater droplet is presented. Foils for transmission electron microscopy (TEM) were made from local attack sites using a focussed ion beam/scanning electron microscope (FIB/SEM). The sections showed that clusters of S-phase particles underwent dealloying. The resulting copper sponge morphology, banding, preferred orientation and crystal defect structure as a result of plastic deformation have been characterised. With build-up of amorphous corrosion product, physical and electrical isolation of parts of the clusters developed, with the result of copper dissolution from the S-phase remnants.

ONLINE VS OFFLINE: DOES CITY IMAGE MODERATING COMPARISON BETWEEN INFLUENCE PERCEIVED BLOG INFORMATION AND REFERENCE GROUP TOWARD TOURIST VISIT INTENTION?

Directory of Open Access Journals (Sweden)

Angga Pandu Wijaya

2017-03-01

Full Text Available This research aims to investigating the phenomenon of perceived blog information, reference group, image of a city, and tourists’ intention to visit particular places. Perceived blog information is the online source, while the offline one is reference group. This is the first study comparing on online and offline information influence tourists’ intention to visit particular places. Samples are obtained through an electronic questionnaire involving 177 respondents and analyzed by using PLS-SEM. The results reveal that perceived blog information and reference group significantly influence image of the city and the intention to visit tourism destination. Image of the city moderate the relationship between independent and dependent variables partially. The influence of perceived blog information is greater than the reference group. It is indicates that online information is more influential. The stakeholders of tourism sector can utilize blog in increasing the number of visitors.

Study of copper deposit on a porous electrode of carbon and stainless steel by sem-xrd and image analysis

OpenAIRE

Constanzo-R., Robinson; Pagliero-N., Antonio; Vergara-G., Froilán

2014-01-01

El objetivo de este trabajo fue realizar un análisis cualitativ o de la distribución de un electrodepósito de cobre en el inter ior de electrodos porosos (EP) de acero inoxidable y carbono grafito. Para ello, se reali zaron pruebas de electrodepositación de cobre a nivel de labora torio, con un posterior análisis de cortes de muestras de acero y grafito vía Microscopía Estereoscópica, Microscopía SEM-DRX y Análisis de Imagen, los cuales mostraron que el cobre no se deposita en forma uniforme ...

El semáforo loco

OpenAIRE

González de Zachrisson, Hena

2016-01-01

El semáforo lo acababan de instalar en Vía Brasil y Calle 50 y estaba contento de poder mantener el orden del tránsito en tan importante calle. Sin embargo, pronto descubrió que su tarea no era fácil. Su territorio estaba atestado de muchachos que vendían frutas y vegetales y para escapar de ellos, los conductores hacían regatas para cruzar la calle antes de que la luz cambiara a rojo. —Todo a un dólar! —gritaban los chicos mostrando su bolsa de guineo, naranja, melón, maíz, papaya, c...

Scanning electron microscopy physics of image formation and microanalysis

CERN Document Server

Reimer, Ludwig

1985-01-01

The aim of this book is to outline the physics of image formation, electron­ specimen interactions, imaging modes, the interpretation of micrographs and the use of quantitative modes "in scanning electron microscopy (SEM). lt forms a counterpart to Transmission Electron Microscopy (Vol. 36 of this Springer Series in Optical Sciences) . The book evolved from lectures delivered at the University of Münster and from a German text entitled Raster-Elektronenmikroskopie (Springer-Verlag), published in collaboration with my colleague Gerhard Pfefferkorn. In the introductory chapter, the principles of the SEM and of electron­ specimen interactions are described, the most important imaging modes and their associated contrast are summarized, and general aspects of eiemental analysis by x-ray and Auger electron emission are discussed. The electron gun and electron optics are discussed in Chap. 2 in order to show how an electron probe of small diameter can be formed, how the elec­ tron beam can be blanked at high fre...

Probability-of-Superiority SEM (PS-SEM—Detecting Probability-Based Multivariate Relationships in Behavioral Research

Directory of Open Access Journals (Sweden)

Johnson Ching-Hong Li

2018-06-01

Full Text Available In behavioral research, exploring bivariate relationships between variables X and Y based on the concept of probability-of-superiority (PS has received increasing attention. Unlike the conventional, linear-based bivariate relationship (e.g., Pearson's correlation, PS defines that X and Y can be related based on their likelihood—e.g., a student who is above mean in SAT has 63% likelihood of achieving an above-mean college GPA. Despite its increasing attention, the concept of PS is restricted to a simple bivariate scenario (X-Y pair, which hinders the development and application of PS in popular multivariate modeling such as structural equation modeling (SEM. Therefore, this study addresses an empirical-based simulation study that explores the potential of detecting PS-based relationship in SEM, called PS-SEM. The simulation results showed that the proposed PS-SEM method can detect and identify PS-based when data follow PS-based relationships, thereby providing a useful method for researchers to explore PS-based SEM in their studies. Conclusions, implications, and future directions based on the findings are also discussed.

Raman-in-SEM, a multimodal and multiscale analytical tool: performance for materials and expertise.

Science.gov (United States)

Wille, Guillaume; Bourrat, Xavier; Maubec, Nicolas; Lahfid, Abdeltif

2014-12-01

The availability of Raman spectroscopy in a powerful analytical scanning electron microscope (SEM) allows morphological, elemental, chemical, physical and electronic analysis without moving the sample between instruments. This paper documents the metrological performance of the SEMSCA commercial Raman interface operated in a low vacuum SEM. It provides multiscale and multimodal analyses as Raman/EDS, Raman/cathodoluminescence or Raman/STEM (STEM: scanning transmission electron microscopy) as well as Raman spectroscopy on nanomaterials. Since Raman spectroscopy in a SEM can be influenced by several SEM-related phenomena, this paper firstly presents a comparison of this new tool with a conventional micro-Raman spectrometer. Then, some possible artefacts are documented, which are due to the impact of electron beam-induced contamination or cathodoluminescence contribution to the Raman spectra, especially with geological samples. These effects are easily overcome by changing or adapting the Raman spectrometer and the SEM settings and methodology. The deletion of the adverse effect of cathodoluminescence is solved by using a SEM beam shutter during Raman acquisition. In contrast, this interface provides the ability to record the cathodoluminescence (CL) spectrum of a phase. In a second part, this study highlights the interest and efficiency of the coupling in characterizing micrometric phases at the same point. This multimodal approach is illustrated with various issues encountered in geosciences. Copyright © 2014 Elsevier Ltd. All rights reserved.

Implied Movement in Static Images Reveals Biological Timing Processing

Directory of Open Access Journals (Sweden)

Francisco Carlos Nather

2015-08-01

Full Text Available Visual perception is adapted toward a better understanding of our own movements than those of non-conspecifics. The present study determined whether time perception is affected by pictures of different species by considering the evolutionary scale. Static (“S” and implied movement (“M” images of a dog, cheetah, chimpanzee, and man were presented to undergraduate students. S and M images of the same species were presented in random order or one after the other (S-M or M-S for two groups of participants. Movement, Velocity, and Arousal semantic scales were used to characterize some properties of the images. Implied movement affected time perception, in which M images were overestimated. The results are discussed in terms of visual motion perception related to biological timing processing that could be established early in terms of the adaptation of humankind to the environment.

Helium Ion Microscopy (HIM) for the imaging of biological samples at sub-nanometer resolution

Science.gov (United States)

Joens, Matthew S.; Huynh, Chuong; Kasuboski, James M.; Ferranti, David; Sigal, Yury J.; Zeitvogel, Fabian; Obst, Martin; Burkhardt, Claus J.; Curran, Kevin P.; Chalasani, Sreekanth H.; Stern, Lewis A.; Goetze, Bernhard; Fitzpatrick, James A. J.

2013-12-01

Scanning Electron Microscopy (SEM) has long been the standard in imaging the sub-micrometer surface ultrastructure of both hard and soft materials. In the case of biological samples, it has provided great insights into their physical architecture. However, three of the fundamental challenges in the SEM imaging of soft materials are that of limited imaging resolution at high magnification, charging caused by the insulating properties of most biological samples and the loss of subtle surface features by heavy metal coating. These challenges have recently been overcome with the development of the Helium Ion Microscope (HIM), which boasts advances in charge reduction, minimized sample damage, high surface contrast without the need for metal coating, increased depth of field, and 5 angstrom imaging resolution. We demonstrate the advantages of HIM for imaging biological surfaces as well as compare and contrast the effects of sample preparation techniques and their consequences on sub-nanometer ultrastructure.

Analysis of shape and spatial interaction of synaptic vesicles using data from focused ion beam scanning electron microscopy (FIB-SEM)

DEFF Research Database (Denmark)

Khanmohammadi, Mahdieh; Waagepetersen, Rasmus Plenge; Sporring, Jon

2015-01-01

deviations from spherical shape and systematic trends in their orientation. We studied three-dimensional representations of synapses obtained by manual annotation of focused ion beam scanning electron microscopy (FIB-SEM) images of male mouse brain. The configurations of synaptic vesicles were regarded...... in excitatory synapses appeared to be of oblate ellipsoid shape and in inhibitory synapses appeared to be of cigar ellipsoid shape, and followed a systematic pattern regarding their orientation towards the active zone. Moreover, there was strong evidence of spatial alignment in the orientations of pairs...

Experimental sharp force injuries to ribs: Multimodal morphological and geometric morphometric analyses using micro-CT, macro photography and SEM.

Science.gov (United States)

Komo, Larissa; Grassberger, Martin

2018-07-01

Tool marks on bones induced by knife blades can be analysed morphometrically in order to enable an allocation of the suspected "inflicting weapon" to the particular morphology of the bone lesions. Until now, geometric morphometrics has not been used to analyse the morphology of knife lesions on fleshed bones in detail. By using twelve experimental knives and a drop weight tower, stab/cut injuries were inflicted on untreated pig ribs. The morphology of the experimentally produced lesions was subsequently recorded with three imaging techniques (μCT, macro photography and SEM) and analysed with different morphometric software (Amira, tps and Morpheus). Based on the measured distances between the walls of the kerf marks, which corresponded to the thickness of the blade, one could conclude to the respective blade thickness with a deviation of max. ±0.35mm and match the injuries to the knives. With subsequent reanalysis after maceration, an average shrinkage factor up to 8.6% was observed. Among the three imaging techniques used in this study, μCT was the most accurate and efficient technique, particularly because it represented the only non-destructive modality to document injuries without maceration, even though μCT is more expensive and time-consuming as well as less accessible than a macro SLR-camera or a SEM. For optimal characterizations of the blades' and kerfs' shapes the software tps proofed to be the best choice. Accordingly, geometric morphometrics could serve as a tool in forensic investigations concerning kerf marks. Copyright © 2018 Elsevier B.V. All rights reserved.

PET Imaging Reveals Brain Metabolic Changes in Adolescent Rats Following Chronic Escalating Morphine Administration.

Science.gov (United States)

Chen, Qing; Hou, Haifeng; Feng, Jin; Zhang, Xiaohui; Chen, Yao; Wang, Jing; Ji, Jianfeng; He, Xiao; Wu, Hao; Zhang, Hong

2018-04-10

Non-medical use of prescription opioids, especially among adolescents, has been substantially increased in recent years. However, the neuromechanism remains largely unexplored. In the present study, we aimed to investigate the brain metabolic changes in adolescent rats following chronic escalating morphine administration using positron emission tomography (PET). 2-Deoxy-2-[ 18 F]Fluoro-D-glucose ([ 18 F]FDG) microPET imaging was performed, and statistical parametric mapping (SPM) was used for image analysis. Glucose transporter 3 (Glut-3), dopamine D 2 receptor (D 2 R), and Mμ-opioid receptor (μ-OR) were used for immunostaining analysis. Cerebral glucose metabolism was increased in the corpus callosum (CC) and right retrosplenial dysgranular cortex (rRSD), while it was decreased in the right ventral pallidum (rVP). The expressions of Glut-3, D 2 R, and μ-OR were increased in CC and rRSD, while they were decreased in rVP. Furthermore, glucose metabolism and Glut-3 expression were positively correlated with the expressions of D 2 R or μ-OR in CC, rRSD, and rVP. [ 18 F]FDG microPET brain imaging study in combination with immunohistological investigation revealed that CC, rRSD, and rVP were specifically involved in opioid dependence in adolescents. Our findings provided valuable insights into the neuromechanism of adolescent addiction of prescription opioids and might have important implications for the development of prevention and intervention approaches.

Canticum Novum: música sem palavras e palavras sem som no pensamento de Santo Agostinho

OpenAIRE

Mammì, Lorenzo

2000-01-01

NO De Magistro, Santo Agostinho coloca a reza e o canto numa posição similar, à margem das funções imediatamente comunicativas da linguagem. A reflexão agostiniana sobre a reza se baseia nos hábitos cristãos da leitura, da oração e da meditação silenciosas. Há sobre o canto, na prática igualmente inovadora do jubilus, melodia sem palavra destinada aos momentos mais intensos e gaudiosos da liturgia. A oração silenciosa e o jubilus são temas recorrentes da literatura patrística, mas Agostinho o...

Multimodal assessment of SERS nanoparticle biodistribution post ingestion reveals new potential for clinical translation of Raman imaging.

Science.gov (United States)

Campbell, Jos L; SoRelle, Elliott D; Ilovich, Ohad; Liba, Orly; James, Michelle L; Qiu, Zhen; Perez, Valerie; Chan, Carmel T; de la Zerda, Adam; Zavaleta, Cristina

2017-08-01

Despite extensive research and development, new nano-based diagnostic contrast agents have faced major barriers in gaining regulatory approval due to their potential systemic toxicity and prolonged retention in vital organs. Here we use five independent biodistribution techniques to demonstrate that oral ingestion of one such agent, gold-silica Raman nanoparticles, results in complete clearance with no systemic toxicity in living mice. The oral delivery mimics topical administration to the oral cavity and gastrointestinal (GI) tract as an alternative to intravenous injection. Biodistribution and clearance profiles of orally (OR) vs. intravenously (IV) administered Raman nanoparticles were assayed over the course of 48 h. Mice given either an IV or oral dose of Raman nanoparticles radiolabeled with approximately 100 μCi (3.7MBq) of 64 Cu were imaged with dynamic microPET immediately post nanoparticle administration. Static microPET images were also acquired at 2 h, 5 h, 24 h and 48 h. Mice were sacrificed post imaging and various analyses were performed on the excised organs to determine nanoparticle localization. The results from microPET imaging, gamma counting, Raman imaging, ICP-MS, and hyperspectral imaging of tissue sections all correlated to reveal no evidence of systemic distribution of Raman nanoparticles after oral administration and complete clearance from the GI tract within 24 h. Paired with the unique signals and multiplexing potential of Raman nanoparticles, this approach holds great promise for realizing targeted imaging of tumors and dysplastic tissues within the oral cavity and GI-tract. Moreover, these results suggest a viable path for the first translation of high-sensitivity Raman contrast imaging into clinical practice. Copyright © 2017 Elsevier Ltd. All rights reserved.

Quantitative methods for the analysis of electron microscope images

DEFF Research Database (Denmark)

Skands, Peter Ulrik Vallø

1996-01-01

The topic of this thesis is an general introduction to quantitative methods for the analysis of digital microscope images. The images presented are primarily been acquired from Scanning Electron Microscopes (SEM) and interfermeter microscopes (IFM). The topic is approached though several examples...... foundation of the thesis fall in the areas of: 1) Mathematical Morphology; 2) Distance transforms and applications; and 3) Fractal geometry. Image analysis opens in general the possibility of a quantitative and statistical well founded measurement of digital microscope images. Herein lies also the conditions...

Epithelial invasion outcompetes hypha development during Candida albicans infection as revealed by an image-based systems biology approach.

Science.gov (United States)

Mech, Franziska; Wilson, Duncan; Lehnert, Teresa; Hube, Bernhard; Thilo Figge, Marc

2014-02-01

Candida albicans is the most common opportunistic fungal pathogen of the human mucosal flora, frequently causing infections. The fungus is responsible for invasive infections in immunocompromised patients that can lead to sepsis. The yeast to hypha transition and invasion of host-tissue represent major determinants in the switch from benign colonizer to invasive pathogen. A comprehensive understanding of the infection process requires analyses at the quantitative level. Utilizing fluorescence microscopy with differential staining, we obtained images of C. albicans undergoing epithelial invasion during a time course of 6 h. An image-based systems biology approach, combining image analysis and mathematical modeling, was applied to quantify the kinetics of hyphae development, hyphal elongation, and epithelial invasion. The automated image analysis facilitates high-throughput screening and provided quantities that allow for the time-resolved characterization of the morphological and invasive state of fungal cells. The interpretation of these data was supported by two mathematical models, a kinetic growth model and a kinetic transition model, that were developed using differential equations. The kinetic growth model describes the increase in hyphal length and revealed that hyphae undergo mass invasion of epithelial cells following primary hypha formation. We also provide evidence that epithelial cells stimulate the production of secondary hyphae by C. albicans. Based on the kinetic transition model, the route of invasion was quantified in the state space of non-invasive and invasive fungal cells depending on their number of hyphae. This analysis revealed that the initiation of hyphae formation represents an ultimate commitment to invasive growth and suggests that in vivo, the yeast to hypha transition must be under exquisitely tight negative regulation to avoid the transition from commensal to pathogen invading the epithelium. © 2013 International Society for

Infrared spectra, Raman laser, XRD, DSC/TGA and SEM ...

Indian Academy of Sciences (India)

Administrator

cussed and the X-ray diffraction, scanning electron microscopy (SEM) and atomic force microscope (AFM) ... acetamide as a simple organic compound at high tempera- ture has less ..... properties of selenium surface, AFM-microscopy tapping.

Study of the magnetic microstructure of high-coercivity sintered SmCo5 permanent magnets with the conventional Bitter pattern technique and the colloid-SEM method

International Nuclear Information System (INIS)

Szmaja, Witold

2007-01-01

The magnetic microstructure of high-coercivity sintered SmCo 5 permanent magnets was studied with the conventional Bitter pattern technique, and also for the first time with the colloid-scanning electron microscopy (colloid-SEM) method. Both techniques were supported by digital image acquisition, enhancement and analysis. Thanks to this, it was possible to obtain high-contrast and clear images of the magnetic microstructure and to analyze them in detail, and consequently also to achieve improvements over earlier results. In the thermally demagnetized state the grains were composed of magnetic domains. On the surface perpendicular to the alignment axis, the main domains forming a maze pattern and surface reverse spikes were observed. Investigations on the surface parallel to the alignment axis, especially by the colloid-SEM technique, provided a detailed insight into the orientation of grains. The alignment of grains was good, but certainly not perfect; there were also strongly misaligned grains, although generally very rare. In most cases the domain structures within grains were independent of their neighbors, but in some cases (not so rare) the domain walls were observed to continue through the grain boundaries, indicating significant magnetostatic interaction between neighboring grains. Studies of the behavior of the magnetic microstructure under the influence of an external magnetic field, performed for the first time on the surface parallel to the alignment axis (with the conventional Bitter pattern method), showed that the domain walls move easily within the grains and that the magnetization reversal mechanism is mainly related to the nucleation and growth of reverse domains, i.e. that sintered SmCo 5 magnets are nucleation-dominated systems. Groupwise magnetization reversal of adjacent magnetically coupled grains was observed, an unfavorable effect for high-coercivity magnets. Images obtained by the colloid-SEM technique and the conventional Bitter pattern

Imaging-genomics reveals driving pathways of MRI derived volumetric tumor phenotype features in Glioblastoma

International Nuclear Information System (INIS)

Grossmann, Patrick; Gutman, David A.; Dunn, William D. Jr; Holder, Chad A.; Aerts, Hugo J. W. L.

2016-01-01

Glioblastoma (GBM) tumors exhibit strong phenotypic differences that can be quantified using magnetic resonance imaging (MRI), but the underlying biological drivers of these imaging phenotypes remain largely unknown. An Imaging-Genomics analysis was performed to reveal the mechanistic associations between MRI derived quantitative volumetric tumor phenotype features and molecular pathways. One hundred fourty one patients with presurgery MRI and survival data were included in our analysis. Volumetric features were defined, including the necrotic core (NE), contrast-enhancement (CE), abnormal tumor volume assessed by post-contrast T1w (tumor bulk or TB), tumor-associated edema based on T2-FLAIR (ED), and total tumor volume (TV), as well as ratios of these tumor components. Based on gene expression where available (n = 91), pathway associations were assessed using a preranked gene set enrichment analysis. These results were put into context of molecular subtypes in GBM and prognostication. Volumetric features were significantly associated with diverse sets of biological processes (FDR < 0.05). While NE and TB were enriched for immune response pathways and apoptosis, CE was associated with signal transduction and protein folding processes. ED was mainly enriched for homeostasis and cell cycling pathways. ED was also the strongest predictor of molecular GBM subtypes (AUC = 0.61). CE was the strongest predictor of overall survival (C-index = 0.6; Noether test, p = 4x10 −4 ). GBM volumetric features extracted from MRI are significantly enriched for information about the biological state of a tumor that impacts patient outcomes. Clinical decision-support systems could exploit this information to develop personalized treatment strategies on the basis of noninvasive imaging. The online version of this article (doi:10.1186/s12885-016-2659-5) contains supplementary material, which is available to authorized users

Enabling CD SEM metrology for 5nm technology node and beyond

Science.gov (United States)

Lorusso, Gian Francesco; Ohashi, Takeyoshi; Yamaguchi, Astuko; Inoue, Osamu; Sutani, Takumichi; Horiguchi, Naoto; Bömmels, Jürgen; Wilson, Christopher J.; Briggs, Basoene; Tan, Chi Lim; Raymaekers, Tom; Delhougne, Romain; Van den Bosch, Geert; Di Piazza, Luca; Kar, Gouri Sankar; Furnémont, Arnaud; Fantini, Andrea; Donadio, Gabriele Luca; Souriau, Laurent; Crotti, Davide; Yasin, Farrukh; Appeltans, Raf; Rao, Siddharth; De Simone, Danilo; Rincon Delgadillo, Paulina; Leray, Philippe; Charley, Anne-Laure; Zhou, Daisy; Veloso, Anabela; Collaert, Nadine; Hasumi, Kazuhisa; Koshihara, Shunsuke; Ikota, Masami; Okagawa, Yutaka; Ishimoto, Toru

2017-03-01

The CD SEM (Critical Dimension Scanning Electron Microscope) is one of the main tools used to estimate Critical Dimension (CD) in semiconductor manufacturing nowadays, but, as all metrology tools, it will face considerable challenges to keep up with the requirements of the future technology nodes. The root causes of these challenges are not uniquely related to the shrinking CD values, as one might expect, but to the increase in complexity of the devices in terms of morphology and chemical composition as well. In fact, complicated threedimensional device architectures, high aspect ratio features, and wide variety of materials are some of the unavoidable characteristics of the future metrology nodes. This means that, beside an improvement in resolution, it is critical to develop a CD SEM metrology capable of satisfying the specific needs of the devices of the nodes to come, needs that sometimes will have to be addressed through dramatic changes in approach with respect to traditional CD SEM metrology. In this paper, we report on the development of advanced CD SEM metrology at imec on a variety of device platform and processes, for both logic and memories. We discuss newly developed approaches for standard, IIIV, and germanium FinFETs (Fin Field Effect Transistors), for lateral and vertical nanowires (NW), 3D NAND (three-dimensional NAND), STT-MRAM (Spin Transfer Magnetic Torque Random-Access Memory), and ReRAM (Resistive Random Access Memory). Applications for both front-end of line (FEOL) and back-end of line (BEOL) are developed. In terms of process, S/D Epi (Source Drain Epitaxy), SAQP (Self-Aligned Quadruple Patterning), DSA (Dynamic Self-Assembly), and EUVL (Extreme Ultraviolet Lithography) have been used. The work reported here has been performed on Hitachi CG5000, CG6300, and CV5000. In terms of logic, we discuss here the S/D epi defect classification, the metrology optimization for STI (Shallow Trench Isolation) Ge FinFETs, the defectivity of III-V STI Fin

A semântica formal das línguas naturais: histórias e desafios

Directory of Open Access Journals (Sweden)

José Borges Neto

2014-03-01

Full Text Available Este artigo faz um resumo da história dos estudos semânticos noBrasil e no mundo, sobretudo das transformações iniciadas nadécada de 1970 e da abertura para uma semântica formalautônoma, que, hoje em dia, comporta diferentes visões sobre arelação sintaxe e semântica, da centralidade da sintaxe aoisomorfismo sintaxe semântica. Mostramos como as ideias do lógicoRichard Montague impulsionaram, através de Barbara Partee eEmmon Bach entre outros, tais estudos, estimulando o surgimentode novas vertentes, e como essas novas tendências foram inseridasno Brasil pela Unicamp com a ajuda de pesquisadores comoMarcelo Dascal, Rodolfo Ilari e Carlos Franchi. O artigo iniciacom uma breve descrição do que é a semântica formal,diferenciando-a de outras semânticas e, principalmente, dasemântica lógica, praticada pelos filósofos, cujo objetivo é descreverraciocínios válidos. A semântica formal é uma ciência empíricaque busca explicar o conhecimento semântico que um falante tem– sua capacidade de relacionar linguagem a algo que não élinguagem (mundos, modelos, conceitos, a composicionalidade e relações sistemáticas entre sentenças – através de umametalinguagem lógico-matemática. Esse empreendimento temsido bem sucedido, se expandindo para além da semântica emdireção a uma maior interação com a pragmática formal. Astendências atuais são de interação com outras disciplinas – apsicolinguística, por exemplo – e a preocupação com línguas poucodescritas, como as línguas indígenas brasileiras. No Brasil, asemântica formal ganhou impulso com a criação dos workshops etem conseguido um espaço cada vez mais significativo na linguísticanacional e internacional.

Paradox image: a noninvasive index of regional left-ventricular dyskinesis

International Nuclear Information System (INIS)

Holman, B.L.; Wynne, J.; Idoine, J.; Zielonka, J.; Neill, J.

1979-01-01

The paradox image, a functional image of regional dyskinesis derived from the equilibrium (gated) radionuclide ventriculogram, was constructed by subtracting the background-corrected end-diastolic frame from the background-corrected end-systolic frame. In 11 patients showing dyskinesis by contrast ventriculography, the percentage of left-ventricular picture elements containing paradox ranged from 3.6 to 55.6% (21.44% +- 4.45 s.e.m.). In 11 patients with normokinesis and in eight patients with hypookinesis by contrast ventriculography, the left-ventricular picture elements demonstrating paradox were less than 1.1% in all cases. In nine patients with akinesis, the percentage of left-ventricular picture elements containing paradox was 2.05% +- 0.96 s.e.m. and was less than 2% in seven patients. There was also an excellent agreement between the location of dyskinesis on the paradox image and that by contrast ventriculography. The paradox image is a sensitive indicator of left-ventricular dyskinesis and should be useful in the evaluation of patients with suspected left-ventricular asynergy

Resolving Differences in Absolute Irradiance Measurements Between the SOHO/CELIAS/SEM and the SDO/EVE.

Science.gov (United States)

Wieman, S R; Didkovsky, L V; Judge, D L

The Solar EUV Monitor (SEM) onboard SOHO has measured absolute extreme ultraviolet (EUV) and soft X-ray solar irradiance nearly continuously since January 1996. The EUV Variability Experiment (EVE) on SDO, in operation since April of 2010, measures solar irradiance in a wide spectral range that encompasses the band passes (26 - 34 nm and 0.1 - 50 nm) measured by SOHO/SEM. However, throughout the mission overlap, irradiance values from these two instruments have differed by more than the combined stated uncertainties of the measurements. In an effort to identify the sources of these differences and eliminate them, we investigate in this work the effect of reprocessing the SEM data using a more accurate SEM response function (obtained from synchrotron measurements with a SEM sounding-rocket clone instrument taken after SOHO was already in orbit) and time-dependent, measured solar spectral distributions - i.e ., solar reference spectra that were unavailable prior to the launch of the SDO. We find that recalculating the SEM data with these improved parameters reduces mean differences with the EVE measurements from about 20 % to less than 5 % in the 26 - 34 nm band, and from about 35 % to about 15 % for irradiances in the 0.1 - 7 nm band extracted from the SEM 0.1 - 50 nm channel.

What Images Reveal: a Comparative Study of Science Images between Australian and Taiwanese Junior High School Textbooks

Science.gov (United States)

Ge, Yun-Ping; Unsworth, Len; Wang, Kuo-Hua; Chang, Huey-Por

2017-07-01

From a social semiotic perspective, image designs in science textbooks are inevitably influenced by the sociocultural context in which the books are produced. The learning environments of Australia and Taiwan vary greatly. Drawing on social semiotics and cognitive science, this study compares classificational images in Australian and Taiwanese junior high school science textbooks. Classificational images are important kinds of images, which can represent taxonomic relations among objects as reported by Kress and van Leeuwen (Reading images: the grammar of visual design, 2006). An analysis of the images from sample chapters in Australian and Taiwanese high school science textbooks showed that the majority of the Taiwanese images are covert taxonomies, which represent hierarchical relations implicitly. In contrast, Australian classificational images included diversified designs, but particularly types with a tree structure which depicted overt taxonomies, explicitly representing hierarchical super-ordinate and subordinate relations. Many of the Taiwanese images are reminiscent of the specimen images in eighteenth century science texts representing "what truly is", while more Australian images emphasize structural objectivity. Moreover, Australian images support cognitive functions which facilitate reading comprehension. The relationships between image designs and learning environments are discussed and implications for textbook research and design are addressed.

Diferenciador semántico: bipolaridad del espacio semántico, un problema de medida del significado

OpenAIRE

Álvarez C., Ramiro

2012-01-01

En relación con el supuesto de bipolaridad y su aspecto recíprocamente antagónico, Osgood y otros (1957) han ligado su modelo de espacio semántico a la teoría del aprendizaje. Plantean la hipótesis de que cierto estimulo externo, o signo, desencadena un proceso mediacional interno (nn) el cual se constituye en emisor de estímulos (rm 15m). Este es el rm mediacional que contendría el significado del signo. La teoría de mediación la relacionan con el supuesto de bipolaridad en los siguientes té...

Application of image recognition algorithms for statistical description of nano- and microstructured surfaces

Energy Technology Data Exchange (ETDEWEB)

Mărăscu, V.; Dinescu, G. [National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Street, Bucharest– Magurele (Romania); Faculty of Physics, University of Bucharest, 405 Atomistilor Street, Bucharest-Magurele (Romania); Chiţescu, I. [Faculty of Mathematics and Computer Science, University of Bucharest, 14 Academiei Street, Bucharest (Romania); Barna, V. [Faculty of Physics, University of Bucharest, 405 Atomistilor Street, Bucharest-Magurele (Romania); Ioniţă, M. D.; Lazea-Stoyanova, A.; Mitu, B., E-mail: mitub@infim.ro [National Institute for Lasers, Plasma and Radiation Physics, 409 Atomistilor Street, Bucharest– Magurele (Romania)

2016-03-25

In this paper we propose a statistical approach for describing the self-assembling of sub-micronic polystyrene beads on silicon surfaces, as well as the evolution of surface topography due to plasma treatments. Algorithms for image recognition are used in conjunction with Scanning Electron Microscopy (SEM) imaging of surfaces. In a first step, greyscale images of the surface covered by the polystyrene beads are obtained. Further, an adaptive thresholding method was applied for obtaining binary images. The next step consisted in automatic identification of polystyrene beads dimensions, by using Hough transform algorithm, according to beads radius. In order to analyze the uniformity of the self–assembled polystyrene beads, the squared modulus of 2-dimensional Fast Fourier Transform (2- D FFT) was applied. By combining these algorithms we obtain a powerful and fast statistical tool for analysis of micro and nanomaterials with aspect features regularly distributed on surface upon SEM examination.

Application of image recognition algorithms for statistical description of nano- and microstructured surfaces

International Nuclear Information System (INIS)

Mărăscu, V.; Dinescu, G.; Chiţescu, I.; Barna, V.; Ioniţă, M. D.; Lazea-Stoyanova, A.; Mitu, B.

2016-01-01

In this paper we propose a statistical approach for describing the self-assembling of sub-micronic polystyrene beads on silicon surfaces, as well as the evolution of surface topography due to plasma treatments. Algorithms for image recognition are used in conjunction with Scanning Electron Microscopy (SEM) imaging of surfaces. In a first step, greyscale images of the surface covered by the polystyrene beads are obtained. Further, an adaptive thresholding method was applied for obtaining binary images. The next step consisted in automatic identification of polystyrene beads dimensions, by using Hough transform algorithm, according to beads radius. In order to analyze the uniformity of the self–assembled polystyrene beads, the squared modulus of 2-dimensional Fast Fourier Transform (2- D FFT) was applied. By combining these algorithms we obtain a powerful and fast statistical tool for analysis of micro and nanomaterials with aspect features regularly distributed on surface upon SEM examination.

SEM Characterization of the High Burn-up Microstructure of U-7Mo Alloy

Energy Technology Data Exchange (ETDEWEB)

Dennis D. Keiser, Jr.; Jan-Fong Jue; Jian Gan; Brandon Miller; Adam Robinson; Pavel Medvedev; James Madden; Dan Wachs; M. Teague

2014-04-01

During irradiation, the microstructure of U-7Mo evolves until at a fission density near 5x1021 f/cm3 a high-burnup microstructure exists that is very different than what was observed at lower fission densities. This microstructure is dominated by randomly distributed, relatively large, homogeneous fission gas bubbles. The bubble superlattice has collapsed in many microstructural regions, and the fuel grain sizes, in many areas, become sub-micron in diameter with both amorphous fuel and crystalline fuel present. Solid fission product precipitates can be found inside the fission gas bubbles. To generate more information about the characteristics of the high-fission density microstructure, three samples irradiated in the RERTR-7 experiment have been characterized using a scanning electron microscope equipped with a focused ion beam. The FIB was used to generate samples for SEM imaging and to perform 3D reconstruction of the microstructure, which can be used to look for evidence of possible fission gas bubble interlinkage.

Super resolution reconstruction of μ-CT image of rock sample using neighbour embedding algorithm

Science.gov (United States)

Wang, Yuzhu; Rahman, Sheik S.; Arns, Christoph H.

2018-03-01

X-ray computed tomography (μ-CT) is considered to be the most effective way to obtain the inner structure of rock sample without destructions. However, its limited resolution hampers its ability to probe sub-micro structures which is critical for flow transportation of rock sample. In this study, we propose an innovative methodology to improve the resolution of μ-CT image using neighbour embedding algorithm where low frequency information is provided by μ-CT image itself while high frequency information is supplemented by high resolution scanning electron microscopy (SEM) image. In order to obtain prior for reconstruction, a large number of image patch pairs contain high- and low- image patches are extracted from the Gaussian image pyramid generated by SEM image. These image patch pairs contain abundant information about tomographic evolution of local porous structures under different resolution spaces. Relying on the assumption of self-similarity of porous structure, this prior information can be used to supervise the reconstruction of high resolution μ-CT image effectively. The experimental results show that the proposed method is able to achieve the state-of-the-art performance.

Angularly-selective transmission imaging in a scanning electron microscope.

Science.gov (United States)

Holm, Jason; Keller, Robert R

2016-08-01

This work presents recent advances in transmission scanning electron microscopy (t-SEM) imaging control capabilities. A modular aperture system and a cantilever-style sample holder that enable comprehensive angular selectivity of forward-scattered electrons are described. When combined with a commercially available solid-state transmission detector having only basic bright-field and dark-field imaging capabilities, the advances described here enable numerous transmission imaging modes. Several examples are provided that demonstrate how contrast arising from diffraction to mass-thickness can be obtained. Unanticipated image contrast at some imaging conditions is also observed and addressed. Published by Elsevier B.V.

Development of an Economical Interfacing Circuit for Upgrading of SEM Data Printing System

International Nuclear Information System (INIS)

Punnachaiya, S.; Thong-Aram, D.

2002-01-01

The operating conditions of a Scanning Electron Microscope (SEM) i.e., magnification, accelerating voltage, micron mark and film identification labeling, are very important for the accurate interpretation of a micrograph picture. In the old model SEM, the built-in data printing system for film identification can be inputted only the numerical number. This will be made a confusing problems when various operating conditions were applied in routine work. An economical interfacing circuit, therefore, was developed to upgrade the data printing system for capable of alphanumerical labeling. The developed circuit was tested on both data printing systems of JSM-T220 and JSM-T330 (JEOL SEM). It was found that the interfacing function worked properly and easily installed

Backpack SEM, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The JPL web page devoted to looking for life on Mars has two images. The first is an image of a hydrothermal pool at Yellowstone: the kind of place life might begin....

Understanding the Online : Jewellery Retail Market : an integrated model to conduct SEM

OpenAIRE

Wu, Yihong

2013-01-01

Research into e-commerce is becoming more and more popular; however the jewellery industry is somewhat special. There are very few studies having adapted a strategic marketing perspective on the online jewellery retail market. This study suggested an integrated online marketing strategy which focuses on the search engine marketing (SEM) approach. A detailed procedure of conducting search engine marketing (SEM) is introduced. Through the method of online questionnaires, with the help of soc...

Tomographic spectral imaging: microanalysis in 3D

International Nuclear Information System (INIS)

Kotula, P.G.; Keenan, M.R.; Michael, J.R.

2003-01-01

Full text: Spectral imaging, where a series of complete x-ray spectra are typically collected from a 2D area, holds great promise for comprehensive near-surface microanalysis. There are however numerous microanalysis problems where 3D chemical information is needed as well. In the SEM, some sort of sectioning (either mechanical or with a focused ion beam (FIB) tool) followed by x-ray mapping has, in the past, been utilized in an attempt to perform 3D microanalysis. Reliance on simple mapping has the potential to miss important chemical features as well as misidentify others. In this paper we will describe the acquisition of serial-section tomographic spectral images (TSI) with a dual-beam FIB/SEM equipped with an EDS system. We will also describe the application of a modified version of our multivariate statistical analysis algorithms to TSIs. Serial sectioning was performed with a FEI DB-235 FIB/SEM. Firstly, the specimen normal was tilted to the optic axis of the FIB column and a trench was milled into the surface of the specimen. A second trench was then milled perpendicular to the first to provide visibility of the entire analysis surface to the x-ray detector. In addition, several fiducial markers were milled into the surface to allow for alignment from slice to slice. The electron column is at an angle of 52 deg to the ion column so the electron beam can 'see' the analysis surface milled by the FIB with no additional specimen tilting or rotation. Likewise the x-ray detector is at a radial angle of 45 deg to the plane of the electron and ion columns (about the electron column) and a take-off-angle of 35 deg with respect to an untilted specimen so it can 'see' the analysis surface as well with no additional sample tilting or rotation. Spectral images were acquired from regions 40 μm wide and 20μm deep for each slice. Approximately 1μm/slice was milled and 10-12 total slices were cut. Spectral images were acquired with a Thermo NORAN Vantage (Digital imaging

Tracking calcification in tissue-engineered bone using synchrotron micro-FTIR and SEM.

Science.gov (United States)

Deegan, Anthony J; Cinque, Gianfelice; Wehbe, Katia; Konduru, Sandeep; Yang, Ying

2015-02-01

One novel tissue engineering approach to mimic in vivo bone formation is the use of aggregate or micromass cultures. Various qualitative and quantitative techniques, such as histochemical staining, protein assay kits and RT-PCR, have been used previously on cellular aggregate studies to investigate how these intricate arrangements lead to mature bone tissue. However, these techniques struggle to reveal spatial and temporal distribution of proliferation and mineralization simultaneously. Synchrotron-based Fourier transform infrared microspectroscopy (micro-FTIR) offers a unique insight at the molecular scale by coupling high IR sensitivity to organic matter with the high spatial resolution allowed by diffraction limited SR microbeam. This study is set to investigate the effects of culture duration and aggregate size on the dynamics and spatial distribution of calcification in engineered bone aggregates by a combination of micro-FTIR and scanning electron microscopy (SEM)/energy-dispersive X-ray spectroscopy (EDX). A murine bone cell line has been used, and small/large bone aggregates have been induced using different chemically treated culture substrates. Our findings suggest that bone cell aggregate culturing can greatly increase levels of mineralization over short culture periods. The size of the aggregates influences mineralisation rates with larger aggregates mineralizing at a faster rate than their smaller counterparts. The micro-FTIR mapping has demonstrated that mineralization in the larger aggregates initiated from the periphery and spread to the centre, whilst the smaller aggregates have more minerals in the centre at the early stage and deposited more in the periphery after further culturing, implying that aggregate size influences calcification distribution and development over time. SEM/EDX data correlates well with the micro-FTIR results for the total mineral content. Thus, synchrotron-based micro-FTIR can accurately track mineralization process

The use of SEM/EDS method in mineralogical analysis of ordinary chondritic meteorite

Directory of Open Access Journals (Sweden)

Breda Mirtič

2009-12-01

Full Text Available The aim of this study was to evaluate the potential of scanning electron microscopy coupled with energy dispersiveX-ray spectroscopy (SEM/EDS for determination of mineral phases according to their stoichiometry and assessment of mineral composition of ordinary chondritic meteorite. For the purposes of this study, H3 type ordinary chondritic meteorite Abbott was selected. SEM/EDS allows identification and characterisation of mineralphases, whose size is below the resolution of an optical microscope. Mineral phases in chondrules and interstitial matrix were located in backscattered electron (BSE mode and were assessed from atomic proportions of constituent elements, obtained by the EDS analysis. SEM/EDS analyses of mineral phases showed that Abbott meteorite is characterised by Fe-rich (Fe, Ni-alloy kamacite, Fe-sulphide troilite or pyrrhotite, chromite, Mg-rich olivine, orthopyroxene bronzite or hypersthene, clinopyroxene Al-diopside, acid plagioclase oligoclase, accessory mineral chlorapatite and secondary minerals Fe-hydroxides (goethite or lepidocrocite. Results of semi-quantitative analyses confirmed that most of analysed mineralphases conform well to stoichiometric minerals with minor deviations of oxygen from stoichiometric proportions. Comparison between mineral phases in chondrules and interstitial matrix was also performed, however it showed no significant differences in elemental composition.Differences in chemical composition between minerals in interstitial matrix and chondrules are sometimes too small to be discernedby the SEM/EDS, therefore knowledge of SEM/EDS capabilities is important for correct interpretation of chondrite formation.

Sharing of secondary electrons by in-lens and out-lens detector in low-voltage scanning electron microscope equipped with immersion lens.

Science.gov (United States)

Kumagai, Kazuhiro; Sekiguchi, Takashi

2009-03-01

To understand secondary electron (SE) image formation with in-lens and out-lens detector in low-voltage scanning electron microscopy (LV-SEM), we have evaluated SE signals of an in-lens and an out-lens detector in LV-SEM. From the energy distribution spectra of SEs with various boosting voltages of the immersion lens system, we revealed that the electrostatic field of the immersion lens mainly collects electrons with energy lower than 40eV, acting as a low-pass filter. This effect is also observed as a contrast change in LV-SEM images taken by in-lens and out-lens detectors.

The principle of electron microscopy; SEM and TEM

International Nuclear Information System (INIS)

Fauzi, S.H.

1992-01-01

The article reviews the principle of electron microscopy which is used in scanning electron microscope (SEM) and transmission electron microscope (TEM). These instruments are important for the examination and analysis of the microstructural properties of solid objects. Relevance physical concept lies behind the devices are given. The main components of each device are also discussed

Structural brain abnormalities in women with subclinical depression, as revealed by voxel-based morphometry and diffusion tensor imaging.

Science.gov (United States)

Hayakawa, Yayoi K; Sasaki, Hiroki; Takao, Hidemasa; Mori, Harushi; Hayashi, Naoto; Kunimatsu, Akira; Aoki, Shigeki; Ohtomo, Kuni

2013-01-25

Brain structural changes accompany major depressive disorder, but whether subclinical depression is accompanied by similar changes in brain volume and white matter integrity is unknown. By using voxel-based morphometry (VBM) of the gray matter and tract-specific analysis based on diffusion tensor imaging (DTI) of the white matter, we explored the extent to which abnormalities could be identified in specific brain structures of healthy adults with subclinical depression. The subjects were 21 community-dwelling adults with subclinical depression, as measured by their Center for Epidemiologic Studies Depression Scale (CES-D) scores. They were not demented and had no neurological or psychiatric history. We collected brain magnetic resonance images of the patients and of 21 matched control subjects, and we used VBM to analyze the differences in regional gray matter volume between the two groups. Moreover, we examined the white matter integrity by using tract-specific analysis based on the gray matter volume changes revealed by VBM. VBM revealed that the volumes of both anterior cingulate gyri and the right rectal gyrus were smaller in subclinically depressed women than in control women. Calculation of DTI measures in the anterior cingulum bundle revealed a positive correlation between CES-D scale score and radial diffusivity in the right anterior cingulum in subclinically depressed women. The small sample size limits the stability of the reported findings. Gray matter volume reduction and white matter integrity change in specific frontal brain regions may be associated with depressive symptoms in women, even at a subclinical level. Copyright © 2012 Elsevier B.V. All rights reserved.

Scanning electron microscope cathodoluminescence imaging of subgrain boundaries, twins and planar deformation features in quartz

Science.gov (United States)

Hamers, M. F.; Pennock, G. M.; Drury, M. R.

2017-04-01

The study of deformation features has been of great importance to determine deformation mechanisms in quartz. Relevant microstructures in both growth and deformation processes include dislocations, subgrains, subgrain boundaries, Brazil and Dauphiné twins and planar deformation features (PDFs). Dislocations and twin boundaries are most commonly imaged using a transmission electron microscope (TEM), because these cannot directly be observed using light microscopy, in contrast to PDFs. Here, we show that red-filtered cathodoluminescence imaging in a scanning electron microscope (SEM) is a useful method to visualise subgrain boundaries, Brazil and Dauphiné twin boundaries. Because standard petrographic thin sections can be studied in the SEM, the observed structures can be directly and easily correlated to light microscopy studies. In contrast to TEM preparation methods, SEM techniques are non-destructive to the area of interest on a petrographic thin section.

Safety and reliability of the insertable Reveal XT recorder in patients undergoing 3 Tesla brain magnetic resonance imaging.

Science.gov (United States)

Haeusler, Karl Georg; Koch, Lydia; Ueberreiter, Juliane; Coban, Nalan; Safak, Erdal; Kunze, Claudia; Villringer, Kersten; Endres, Matthias; Schultheiss, Heinz-Peter; Fiebach, Jochen B; Schirdewan, Alexander

2011-03-01

Up to now there is little evidence about the safety and reliability of insertable cardiac monitors (ICMs) in patients undergoing magnetic resonance imaging (MRI). The purpose of this prospective single-center study (MACPAF; clinicaltrials.govNCT01061931), which we are currently performing, was to evaluate these issues for the ICM Reveal XT at a 3 Tesla MRI scanner in patients undergoing serial brain MRI. We present an interim analysis including 62 brain MRI examinations in 24 patients with paroxysmal atrial fibrillation bearing the Reveal XT. All patients were interviewed for potential ICM-associated clinical symptoms during and after MRI examination. According to the study protocol, data from the Reveal XT were transmitted before and after the MRI examination. All patients were clinically asymptomatic during the MRI procedure. Moreover, the reliability (ability to detect signals, battery status) of the Reveal XT was unaffected, except for one MRI-induced artifact that was recorded by the ICM, mimicking a narrow complex tachycardia, as similarly recorded in a further study patient bearing the forerunner ICM Reveal DX. No loss of ICM data was observed after the MRI examination. The 3 Tesla brain MRI scanning is safe for patients bearing the ICM Reveal XT and does not alloy reliability of the Reveal XT itself. MRI-induced artifacts occur rarely but have to be taken into account. Copyright © 2011 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

Nanosecond pulsed laser ablation of Ge investigated by employing photoacoustic deflection technique and SEM analysis

International Nuclear Information System (INIS)

Yaseen, Nazish; Bashir, Shazia; Shabbir, Muhammad Kaif; Jalil, Sohail Abdul; Akram, Mahreen; Hayat, Asma; Mahmood, Khaliq; Haq, Faizan-ul; Ahmad, Riaz; Hussain, Tousif

2016-01-01

Nanosecond pulsed laser ablation phenomena of single crystal Ge (100) has been investigated by employing photoacoustic deflection as well as SEM analysis techniques. Nd: YAG laser (1064 nm, 10 ns, 1–10 Hz) at various laser fluences ranging from 0.2 to 11 J cm"−"2 is employed as pump beam to ablate Ge targets. In order to evaluate in-situe ablation threshold fluence of Ge by photoacoustic deflection technique, Continuous Wave (CW) He–Ne laser (632 nm, power 10 mW) is employed as a probe beam. It travels parallel to the target surface at a distance of 3 mm and after passing through Ge plasma it causes deflection due to density gradient of acoustic waves. The deflected signal is detected by photodiode and is recorded by oscilloscope. The threshold fluence of Ge, the velocity of ablated species and the amplitude of the deflected signal are evaluated. The threshold fluence of Ge comes out to be 0.5 J cm"−"2 and is comparable with the analytical value. In order to compare the estimated value of threshold with ex-situe measurements, the quantitative analysis of laser irradiated Ge is performed by using SEM analysis. For this purpose Ge is exposed to single and multiple shots of 5, 10, 50 and 100 at various laser fluences ranging from 0.2 to 11 J cm"−"2. The threshold fluence for single and multiple shots as well as incubation coefficients are evaluated. It is observed that the value of incubation co-efficient decreases with increasing number of pulses and is therefore responsible for lowering the threshold fluence of Ge. SEM analysis also reveals the growth of various features such as porous structures, non-uniform ripples and blisters on the laser irradiated Ge. It is observed that both the fluence as well as number of laser shots plays a significant role for the growth of these structures.

Nanosecond pulsed laser ablation of Ge investigated by employing photoacoustic deflection technique and SEM analysis

Energy Technology Data Exchange (ETDEWEB)

Yaseen, Nazish; Bashir, Shazia; Shabbir, Muhammad Kaif; Jalil, Sohail Abdul; Akram, Mahreen; Hayat, Asma; Mahmood, Khaliq; Haq, Faizan-ul; Ahmad, Riaz; Hussain, Tousif

2016-06-01

Nanosecond pulsed laser ablation phenomena of single crystal Ge (100) has been investigated by employing photoacoustic deflection as well as SEM analysis techniques. Nd: YAG laser (1064 nm, 10 ns, 1–10 Hz) at various laser fluences ranging from 0.2 to 11 J cm{sup −2} is employed as pump beam to ablate Ge targets. In order to evaluate in-situe ablation threshold fluence of Ge by photoacoustic deflection technique, Continuous Wave (CW) He–Ne laser (632 nm, power 10 mW) is employed as a probe beam. It travels parallel to the target surface at a distance of 3 mm and after passing through Ge plasma it causes deflection due to density gradient of acoustic waves. The deflected signal is detected by photodiode and is recorded by oscilloscope. The threshold fluence of Ge, the velocity of ablated species and the amplitude of the deflected signal are evaluated. The threshold fluence of Ge comes out to be 0.5 J cm{sup −2} and is comparable with the analytical value. In order to compare the estimated value of threshold with ex-situe measurements, the quantitative analysis of laser irradiated Ge is performed by using SEM analysis. For this purpose Ge is exposed to single and multiple shots of 5, 10, 50 and 100 at various laser fluences ranging from 0.2 to 11 J cm{sup −2}. The threshold fluence for single and multiple shots as well as incubation coefficients are evaluated. It is observed that the value of incubation co-efficient decreases with increasing number of pulses and is therefore responsible for lowering the threshold fluence of Ge. SEM analysis also reveals the growth of various features such as porous structures, non-uniform ripples and blisters on the laser irradiated Ge. It is observed that both the fluence as well as number of laser shots plays a significant role for the growth of these structures.

Determinación de la microestructuracerámica mediante procesamientoóptico–digital de imágenes MEB Determination of ceramic microstructure by using optical–digital image processing of SEM images

Directory of Open Access Journals (Sweden)

Oscar García Palencia

2010-06-01

Full Text Available En este trabajo se reporta el diseño e implementación de un software para análisis ceramográfico y control de calidad en ciencia de materiales, mediante el estudio de imágenes obtenidas por microscopia electrónica de barrido (MEB de la superficie pulida de muestras de diferentes sistemas cerámicos. El sistema se apoya en el procesamiento óptico digital de imágenes para determinar: el tamaño de cada grano y poro, su factor de redondez y excentricidad como factor de forma. Este trabajo destaca el uso de las técnicas más eficientes de filtrado adaptativo y de detección de bordes, para la realización del cálculo de tamaño de partícula con alta precisión, en comparación con los métodos tradicionales encapsulados en las normas ASTM E112 y E1382. Los resultados más destacados de este análisis, como la posible aplicación de este sistema en otros campos de la investigación tales como la granulometría, la exploración petrolífera, la ingeniería de suelos y las películas delgadas, se presentan en este trabajo, con efectividad superior con otros software comerciales.This paper reports the design and implementation of software to ceramographic analysis and quality control in materials science, through image study obtained by scanning electronic microscopy (SEM, of samples polished surface of different ceramics systems. The system is supported on optics-digital image processing to determine: the size of each grain and pore, it roundness and eccentricity as shape factor. This work stands out the use of more efficient techniques of adaptive filtering and edge detection, to the calculus realization for the particle size with high precision, compared with traditional methods encapsulated inside the norms ASTM E112 and E1382. The most outstanding results of this analysis, as the possible application of this system in other investigation areas such as granulometry, oil exploration, geotechnical engineering and thin films are presented in

Microchip systems for imaging liquid and high temperature processes in TEM & SEM

DEFF Research Database (Denmark)

Jensen, Eric; Canepa, Silvia; Møller-Nilsen, Rolf Erling Robberstad

2014-01-01

Microchips systems have found their way into electron microscopes in order to make miniatureplatforms for controlled liquid and gaseous environments that also begin to include electricalcontacts and other types of interactions with the sample, such as application of forces andirradiation with light.......This presentation will explain the different types of microchip systems and give examples of someof the results we have achieved with our devices and examples of how such devices can be usedfor research related to energy storage and conversion.Heaters can be made in several ways, and monocrystalline silicon......]. Both systems will allowhigh resolution imaging of heterogeneous electrochemical processes such as those in batteries.Based on the suspended microfluidic channels, we are also developing microchips that enableultrafast freezing of processes in liquids....

A detailed TEM and SEM study of Ni-base alloys oxide scales formed in primary conditions of pressurized water reactor

International Nuclear Information System (INIS)

Sennour, Mohamed; Marchetti, Loic; Martin, Frantz; Perrin, Stephane; Molins, Regine; Pijolat, Michele

2010-01-01

The oxide film formed on nickel-based alloys in pressurized water reactors (PWR) primary coolant conditions (325 o C, aqueous media) is very thin, in the range of 1-100 nm thick, depending on the surface state and on the corrosion test duration. The nature and the structure of this scale have been investigated by Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM). TEM observations revealed an oxide layer divided in two parts. The internal layer was mainly composed of a continuous spinel layer, identified as a mixed iron and nickel chromite (Ni (1-x) Fe x Cr 2 O 4 ). Moreover, nodules of Cr 2 O 3 , with a size about 5 nm, were present at the interface between this spinel and the alloy. No chromium depletion was observed in the alloy, at the alloy/oxide interface. The external layer is composed of large crystallites corresponding to a spinel structure rich in iron (Ni (1-z) Fe (2+z) O 4 ) resulting from precipitation phenomena. SEM and TEM observations showed a link between the nucleation and/or the growth of crystallites of nickel ferrite and the crystallographic orientation of the substrate. A link between the presence of surface defects and the nucleation of the crystallites was also underlined by SEM observations. Partially hydrated nickel hydroxide, was also observed by TEM in the external scale. Based on these results, some considerations about the mechanism of formation of this oxide layer are discussed.

Wi-Fi Salvador: mapeamento colaborativo e redes sem fio no Brasil

OpenAIRE

Lemos, André; Pastor, Leonardo; Oliveira, Nelson

2012-01-01

O trabalho faz uma breve demonstração de políticas públicas para inclusão digital por meio da disponibilização do acesso à internet por meio de redes sem fio e discute a forma como as pessoas se relacionam com os lugares, de acordo com a existência ou inexistência de acessibilidade à internet. O objetivo é discutir o acesso à internet pelas redes sem fio no Brasil e, mais especificamente, na cidade de Salvador. Este trabalho é fruto de pesquisa realizada no âmbito do Grupo de Pesquisa em Cibe...

Imaging single atoms using secondary electrons with an aberration-corrected electron microscope.

Science.gov (United States)

Zhu, Y; Inada, H; Nakamura, K; Wall, J

2009-10-01

Aberration correction has embarked on a new frontier in electron microscopy by overcoming the limitations of conventional round lenses, providing sub-angstrom-sized probes. However, improvement of spatial resolution using aberration correction so far has been limited to the use of transmitted electrons both in scanning and stationary mode, with an improvement of 20-40% (refs 3-8). In contrast, advances in the spatial resolution of scanning electron microscopes (SEMs), which are by far the most widely used instrument for surface imaging at the micrometre-nanometre scale, have been stagnant, despite several recent efforts. Here, we report a new SEM, with aberration correction, able to image single atoms by detecting electrons emerging from its surface as a result of interaction with the small probe. The spatial resolution achieved represents a fourfold improvement over the best-reported resolution in any SEM (refs 10-12). Furthermore, we can simultaneously probe the sample through its entire thickness with transmitted electrons. This ability is significant because it permits the selective visualization of bulk atoms and surface ones, beyond a traditional two-dimensional projection in transmission electron microscopy. It has the potential to revolutionize the field of microscopy and imaging, thereby opening the door to a wide range of applications, especially when combined with simultaneous nanoprobe spectroscopy.

Data on the effect of conductive hearing loss on auditory and visual cortex activity revealed by intrinsic signal imaging.

Science.gov (United States)

Teichert, Manuel; Bolz, Jürgen

2017-10-01

This data article provides additional data related to the research article entitled "Simultaneous intrinsic signal imaging of auditory and visual cortex reveals profound effects of acute hearing loss on visual processing" (Teichert and Bolz, 2017) [1]. The primary auditory and visual cortex (A1 and V1) of adult male C57BL/6J mice (P120-P240) were mapped simultaneously using intrinsic signal imaging (Kalatsky and Stryker, 2003) [2]. A1 and V1 activity evoked by combined auditory and visual stimulation were measured before and after conductive hearing loss (CHL) induced by bilateral malleus removal. We provide data showing that A1 responsiveness evoked by sounds of different sound pressure levels (SPL) decreased after CHL whereas visually evoked V1 activity increased after this intervention. In addition, we also provide imaging data on percentage of V1 activity increases after CHL compared to pre-CHL.

La semántica en la Web

OpenAIRE

Roger, Sandra

2004-01-01

El propósito de este trabajo es presentar la motivación de nuestra línea de investigación, metas y desarrollos futuros. Fundamentalmente, nuestro interés se centrará en poder capturar el potencial de las técnicas y paradigmas basadas en conocimiento semántico para la representación de conocimiento, la localización, compartición e integración de recursos a mediante la WWW.

Structuring Consumer Preferences with the SEM Method

OpenAIRE

Rosa, Franco

2002-01-01

Structuring preferences has been developed with econometric models using functional flexible parametric form and the exploring the perceptions about expressed and latent needs using different multivariate approaches. Purpose of this research is to explore the demand for a new drink using the mean-end chain (MEC) theory and multivariate SEM procedure. The first part is dedicated to description of specialty foods for their capacity to create new niche markets. The MEC theory is introduced to ex...

3D imaging and characterisation of strengthening particles in inconel 718 using FIB tomography

Energy Technology Data Exchange (ETDEWEB)

Kruk, Adam; Gruszczynski, Adam; Czyrska-Filemonowicz, Aleksandra [AGH University of Science and Technology, Faculty of Metals Engineering and Industrial Computer Science, Al. A. Mickiewicza 30, 30-059 Krakow (Poland)

2011-07-01

The Inconel 718 is a commercial nickel-base superalloy, widely used for critical pieces in turbine engines. Its microstructure consists of the {gamma} matrix and strengthening coherent nanoparticles {gamma}' and {gamma}''. In the present work FIB tomography technique was used for imaging and characterisation of strengthening particles. FIB tomography is based on a serial sectioning procedure using a FIB/SEM dual beam workstation. Repeated removal of layers as thin as several nm for some hundred times allows to investigate at total a volume of some {mu}m3 with a voxel size as 2.5 nm x 2.5 nm x 2.5 nm. 3D mapping of nanoparticles with high Z-resolution by serial FIB slicing (in a distance of about 2.5 nm) and SEM imaging was performed. Ga ion beam at 30 kV was used to perform a precise in-situ milling. The SEM images at accelerating voltage 1.5 kV were taken with using ESB detector. The real 3D-data of precipitates obtained by FIB tomography, open a new possibility for microstructure analysis of materials for industrial applications.

Multi-scale Multi-dimensional Imaging and Characterization of Oil Shale Pyrolysis

Science.gov (United States)

Gao, Y.; Saif, T.; Lin, Q.; Al-Khulaifi, Y.; Blunt, M. J.; Bijeljic, B.

2017-12-01

The microstructural evaluation of fine grained rocks is challenging which demands the use of several complementary methods. Oil shale, a fine-grained organic-rich sedimentary rock, represents a large and mostly untapped unconventional hydrocarbon resource with global reserves estimated at 4.8 trillion barrels. The largest known deposit is the Eocene Green River Formation in Western Colorado, Eastern Utah, and Southern Wyoming. An improved insight into the mineralogy, organic matter distribution and pore network structure before, during and after oil shale pyrolysis is critical to understanding hydrocarbon flow behaviour and improving recovery. In this study, we image Mahogany zone oil shale samples in two dimensions (2-D) using scanning electron microscopy (SEM), and in three dimensions (3-D) using focused ion beam scanning electron microscopy (FIB-SEM), laboratory-based X-ray micro-tomography (µCT) and synchrotron X-ray µCT to reveal a complex and variable fine grained microstructure dominated by organic-rich parallel laminations which are tightly bound in a highly calcareous and heterogeneous mineral matrix. We report the results of a detailed µCT study of the Mahogany oil shale with increasing pyrolysis temperature. The physical transformation of the internal microstructure and evolution of pore space during the thermal conversion of kerogen in oil shale to produce hydrocarbon products was characterized. The 3-D volumes of pyrolyzed oil shale were reconstructed and image processed to visualize and quantify the volume and connectivity of the pore space. The results show a significant increase in anisotropic porosity associated with pyrolysis between 300-500°C with the formation of micron-scale connected pore channels developing principally along the kerogen-rich lamellar structures.

Real-time CARS imaging reveals a calpain-dependent pathway for paranodal myelin retraction during high-frequency stimulation.

Directory of Open Access Journals (Sweden)

Terry B Huff

2011-03-01

Full Text Available High-frequency electrical stimulation is becoming a promising therapy for neurological disorders, however the response of the central nervous system to stimulation remains poorly understood. The current work investigates the response of myelin to electrical stimulation by laser-scanning coherent anti-Stokes Raman scattering (CARS imaging of myelin in live spinal tissues in real time. Paranodal myelin retraction at the nodes of Ranvier was observed during 200 Hz electrical stimulation. Retraction was seen to begin minutes after the onset of stimulation and continue for up to 10 min after stimulation was ceased, but was found to reverse after a 2 h recovery period. The myelin retraction resulted in exposure of Kv 1.2 potassium channels visualized by immunofluorescence. Accordingly, treating the stimulated tissue with a potassium channel blocker, 4-aminopyridine, led to the appearance of a shoulder peak in the compound action potential curve. Label-free CARS imaging of myelin coupled with multiphoton fluorescence imaging of immuno-labeled proteins at the nodes of Ranvier revealed that high-frequency stimulation induced paranodal myelin retraction via pathologic calcium influx into axons, calpain activation, and cytoskeleton degradation through spectrin break-down.

High-Resolution Imaging Reveals New Features of Nuclear Export of mRNA through the Nuclear Pore Complexes

Directory of Open Access Journals (Sweden)

Joseph M. Kelich

2014-08-01

Full Text Available The nuclear envelope (NE of eukaryotic cells provides a physical barrier for messenger RNA (mRNA and the associated proteins (mRNPs traveling from sites of transcription in the nucleus to locations of translation processing in the cytoplasm. Nuclear pore complexes (NPCs embedded in the NE serve as a dominant gateway for nuclear export of mRNA. However, the fundamental characterization of export dynamics of mRNPs through the NPC has been hindered by several technical limits. First, the size of NPC that is barely below the diffraction limit of conventional light microscopy requires a super-resolution microscopy imaging approach. Next, the fast transit of mRNPs through the NPC further demands a high temporal resolution by the imaging approach. Finally, the inherent three-dimensional (3D movements of mRNPs through the NPC demand the method to provide a 3D mapping of both transport kinetics and transport pathways of mRNPs. This review will highlight the recently developed super-resolution imaging techniques advanced from 1D to 3D for nuclear export of mRNPs and summarize the new features in the dynamic nuclear export process of mRNPs revealed from these technical advances.

Synthesis of Co/MCM-41catalysts and characterization by XRD, EDX, DTA/TG, SEM and TEM

International Nuclear Information System (INIS)

Sousa, B.V.; Rodrigues, M.G.F.

2009-01-01

Full text: In this work, molecular sieve MCM-41 was prepared as well as the Co/MCM-41 catalyst, via humid impregnation with concentration of 5 wt.% and 10 wt.% Co/MCM- 41. The attainment of the mesoporous molecular sieve, Si-MCM-41, was confirmed by the x-ray diffractogram. It was verified that after the calcination all the bromine (Br) was removed indicating that the calcination process removed all surfactant in the mesoporous structure. XRD and EDX analyses indicated that cobalt was found in the form of Co3O2 in the Co/MCM-41 catalysts. The diffraction standards showed that the impregnation and calcination processes caused changes in the structure only for catalyst with 10 wt.% Co/MCM-41. The DTA/TG curves showed that cobalt nitrate was totally decomposed on the MCM-41. From the images of SEM, it was possible to observe that the Co/MCM-41 catalysts were composed by clusters of small crystals. The images obtained from TEM showed clearly the presence of metal cobalt particles in a well dispersed form for catalyst with 5 wt.% Co/MCM41, except for the catalyst with 10 wt.% Co/MCM41. (author)

Carotene location in processed food samples measured by cryo In-SEM Raman.

Science.gov (United States)

Lopez-Sanchez, Patricia; Schumm, Stephan; Pudney, Paul D A; Hazekamp, Johan

2011-09-21

Cryo In-SEM Raman has been used for the first time to localise carotene compounds in a food matrix. Raman spectra of lycopene and β-carotene have been obtained from sampling oil droplets and plant cell structures visualised with cryo-SEM in tomato and carrot based emulsions containing 5% oil. It was possible to identify the carotenoids in both the oil droplets and the cell walls. Furthermore our results gave some indication that the carotenoids were in the non-crystalline state. It has been suggested that a higher amount of carotenes solubilised into the oil phase of the food matrix would lead to a higher bioaccessibility, thus understanding the effect of processing conditions on micronutrients distribution in a food matrix might help the design of plant based food products with a better nutritional quality. This shows improved structural characterisation of the cryo-SEM with the molecular sensitivity of Raman spectroscopy as a promising approach for complex biological problems.

Automated SEM and TEM sample preparation applied to copper/low k materials

Science.gov (United States)

Reyes, R.; Shaapur, F.; Griffiths, D.; Diebold, A. C.; Foran, B.; Raz, E.

2001-01-01

We describe the use of automated microcleaving for preparation of both SEM and TEM samples as done by SELA's new MC500 and TEMstation tools. The MC500 is an automated microcleaving tool that is capable of producing cleaves with 0.25 μm accuracy resulting in SEM-ready samples. The TEMstation is capable of taking a sample output from the MC500 (or from SELA's earlier MC200 tool) and producing a FIB ready slice of 25±5 μm, mounted on a TEM-washer and ready for FIB thinning to electron transparency for TEM analysis. The materials selected for the tool set evaluation mainly included the Cu/TaN/HOSP low-k system. The paper is divided into three sections, experimental approach, SEM preparation and analysis of HOSP low-k, and TEM preparation and analysis of Cu/TaN/HOSP low-k samples. For the samples discussed, data is presented to show the quality of preparation provided by these new automated tools.

Assessment of Paint Layers by FE-SEM and EDS Examination

National Research Council Canada - National Science Library

Harris, Donovan

2004-01-01

.... The approach was to remove free-film samples from each panel, fracture the films, and then examine at high magnification the cross sections using a field emission-scanning electron microscope (FE-SEM...

Soft tissue digestion of Paradiplozoon vaalense for SEM of sclerites and simultaneous molecular analysis.

Science.gov (United States)

Dos Santos, Q M; Avenant-Oldewage, A

2015-02-01

Classification of most monogeneans is primarily based on size, shape, and arrangement of haptoral sclerites. These structures are often obscured or misinterpreted when studied using light microscopy, leading to confusion regarding defining characters. Scanning electron microscopy (SEM) has predominantly been used to study haptoral sclerites in smaller monogeneans, focusing on hooks and anchors. In the Diplozoidae, SEM has not been used to study haptoral sclerites. Using new and modified techniques, the sclerites of diplozoids collected in South Africa were successfully studied using SEM. The digestion buffer from a DNA extraction kit was used to digest the surrounding tissue, and Poly-L-lysine-coated and concavity slides were employed to limit the movement and loss of sclerites, with the latter being more user-friendly. In addition to the success of visualizing the sclerites using SEM, the digested tissue from as little as half of the haptor provided viable genetic material for molecular characterization. From the results presented here, the study of the sclerites of larger monogeneans using SEM, including those bearing clamps, is a viable possibility for future research. Also, this method may be beneficial for the study of other, non-haptoral sclerites, such as cirri in other families of monogeneans. During this study, Labeo capensis was noted as a valid host of Paradiplozoon vaalense in a region of the Vaal River where the type host, Labeo umbratus, appears to be absent.

Detection of glass particles on bone lesions using SEM-EDS.

Science.gov (United States)

Montoriol, Romain; Guilbeau-Frugier, Céline; Chantalat, Elodie; Roumiguié, Mathieu; Delisle, Marie-Bernadette; Payré, Bruno; Telmon, Norbert; Savall, Frédéric

2017-09-01

The problem of identifying the wounding agent in forensic cases is recurrent. Moreover, when several tools are involved, distinguishing the origin of lesions can be difficult. Scanning electron microscopy (SEM)/energy dispersive X-ray analysis (EDS) equipment is increasingly available to the scientific and medical community, and some studies have reported its use in forensic anthropology. However, at our knowledge, no study has reported the use of SEM-EDS in forensic cases involving glass tools, whether in case reports or experiments. We performed an experimental study on human rib fragments, on which we manually created wounds using fragments of window and mirror glass. SEM-EDS was executed on samples without any further preparation on low vacuum mode, then on the same samples after defleshing them completely by boiling them. Window and mirror glass particles were detected on experimental wounds. Both had silica in their spectra, and the opaque side of the mirror contained titanium, allowing for their identification. Boiling and defleshing the bone samples involved a loss of information in terms of the number of wounds detected as positive for glass particles and in the number of glass particles detected, for both window and mirror glass. We suggest the analysis of wounds with suspected glass particles using low vacuum mode and with no defleshment by boiling.

Surface characteristics of isopod digestive gland epithelium studied by SEM.

Science.gov (United States)

Millaku, Agron; Leser, Vladka; Drobne, Damjana; Godec, Matjaz; Torkar, Matjaz; Jenko, Monika; Milani, Marziale; Tatti, Francesco

2010-05-01

The structure of the digestive gland epithelium of a terrestrial isopod Porcellio scaber has been investigated by conventional scanning electron microscopy (SEM), focused ion beam-scanning electron microscopy (FIB/SEM), and light microscopy in order to provide evidence on morphology of the gland epithelial surface in animals from a stock culture. We investigated the shape of cells, extrusion of lipid droplets, shape and distribution of microvilli, and the presence of bacteria on the cell surface. A total of 22 animals were investigated and we found some variability in the appearance of the gland epithelial surface. Seventeen of the animals had dome-shaped digestive gland "normal" epithelial cells, which were densely and homogeneously covered by microvilli and varying proportions of which extruded lipid droplets. On the surface of microvilli we routinely observed sparsely distributed bacteria of different shapes. Five of the 22 animals had "abnormal" epithelial cells with a significantly altered shape. In three of these animals, the cells were much smaller, partly or completely flat or sometimes pyramid-like. A thick layer of bacteria was detected on the microvillous border, and in places, the shape and size of microvilli were altered. In two animals, hypertrophic cells containing large vacuoles were observed indicating a characteristic intracellular infection. The potential of SEM in morphological investigations of epithelial surfaces is discussed.

Simultaneous noncontact topography and electrochemical imaging by SECM/SICM featuring ion current feedback regulation.

Science.gov (United States)

Takahashi, Yasufumi; Shevchuk, Andrew I; Novak, Pavel; Murakami, Yumi; Shiku, Hitoshi; Korchev, Yuri E; Matsue, Tomokazu

2010-07-28

We described a hybrid system of scanning electrochemical microscopy (SECM) and scanning ion conductance microscopy (SICM) with ion current feedback nanopositioning control for simultaneous imaging of noncontact topography and spatial distribution of electrochemical species. A nanopipette/nanoring electrode probe provided submicrometer resolution of the electrochemical measurement on surfaces with complex topology. The SECM/SICM probe had an aperture radius of 220 nm. The inner and outer radii of the SECM Au nanoring electrode were 330 and 550 nm, respectively. Characterization of the probe was performed with scanning electron microscopy (SEM), cyclic voltammetry (CV), and approach curve measurements. SECM/SICM was applied to simultaneous imaging of topography and electrochemical responses of enzymes (horse radish peroxidase (HRP) and glucose oxidase (GOD)) and single live cells (A6 cells, superior cervical ganglion (SCG) cells, and cardiac myocytes). The measurements revealed the distribution of activity of the enzyme spots on uneven surfaces with submicrometer resolution. SECM/SICM acquired high resolution topographic images of cells together with the map of electrochemical signals. This combined technique was also applied to the evaluation of the permeation property of electroactive species through cellular membranes.

SEM Characterization of an Irradiated Monolithic U-10Mo Fuel Plate

International Nuclear Information System (INIS)

Keiser, D.D. Jr.; Jue, J.F.; Robinson, A.B.

2010-01-01

Results of scanning electron microscopy (SEM) characterization of irradiated U-7Mo dispersion fuel plates with differing amounts of matrix Si have been reported. However, to date, no results of SEM analysis of irradiated U-Mo monolithic fuel plates have been reported. This paper describes the first SEM characterization results for an irradiated monolithic U-10Mo fuel plate. Two samples from this fuel plate were characterized. One sample was produced from the low-flux side of the fuel plate, and another was produced at the high-flux side of the fuel plate. This characterization focused on the microstructural features present at the U-10Mo foil/cladding interface, particularly the interaction zone that had developed during fabrication and irradiation. In addition, the microstructure of the foil itself was investigated, along with the morphology of the observed fission gas bubbles. It was observed that a Si-rich interaction layer was present at the U-10Mo foil/cladding interface that exhibited relatively good irradiation behavior, and within the U-10Mo foil the microstructural features differed in some respects from what is typically seen in the U-Mo powders of an irradiated dispersion fuel.

SEM based CARMA time series modeling for arbitrary N

NARCIS (Netherlands)

Oud, J.H.L.; Völkle, M.C.; Driver, C.C.

2018-01-01

This article explains in detail the state space specification and estimation of first and higher-order autoregressive moving-average models in continuous time (CARMA) in an extended structural equation modeling (SEM) context for N = 1 as well as N > 1. To illustrate the approach, simulations will be

How Hedstrom files fail during clinical use? A retrieval study based on SEM, optical microscopy and micro-XCT analysis.

Science.gov (United States)

Zinelis, Spiros; Al Jabbari, Youssef S

2018-05-01

This study was conducted to evaluate the failure mechanism of clinically failed Hedstrom (H)-files. Discarded H-files (n=160) from #8 to #40 ISO sizes were collected from different dental clinics. Retrieved files were classified according to their macroscopic appearance and they were investigated under scanning electron microscopy (SEM) and X-ray micro-computed tomography (mXCT). Then the files were embedded in resin along their longitudinal axis and after metallographic grinding and polishing, studied under an incident light microscope. The macroscopic evaluation showed that small ISO sizes (#08-#15) failed by extensive plastic deformation, while larger sizes (≥#20) tended to fracture. Light microscopy and mXCT results coincided showing that unused and plastically deformed files were free of internal defects, while fractured files demonstrate the presence of intense cracking in the flute region. SEM analysis revealed the presence of striations attributed to the fatigue mechanism. Secondary cracks were also identified by optical microscopy and their distribution was correlated to fatigue under bending loading. Experimental results demonstrated that while overloading of cutting instruments is the predominating failure mechanism of small file sizes (#08-#15), fatigue should be considered the fracture mechanism for larger sizes (≥#20).

La semántica del adjetivo y su representación mediante estructura de rasgos

OpenAIRE

Climent Roca, Salvador

1995-01-01

Por el trabajo que se describe se ha formulado un marco general de representación semántica de los adjetivos en una base de conocimiento léxica basada en estructuras de rasgos en la que operan la herencia y la unificación. Como principales aportaciones cabe destacar el propio diseño de un marco representativo suficientemente expresivo como para abarcar múltiples aspectos del significado del adjetivo, tales como orden superficial, restricciones selectivas, semántica léxica y semántica formal. ...

Comparative study of dental enamel loss after debonding braces by analytical scanning electron microscopy (SEM).

Science.gov (United States)

Rodríguez-Chávez, Jacqueline Adelina; Arenas-Alatorre, Jesús; Belio-Reyes, Irma Araceli

2017-07-01

Clinical procedures when shear forces are applied to brackets suggest adhesion forces between 2.8 and 10.0 MPa as appropriate. In this study dental enamel was evaluated by scanning electron microscopy (SEM) before and after removing the brackets. Thirty bicuspids (previous prophylaxis) with metallic brackets (Roth Inovation 0.022 GAC), Transbond Plus SEP 3M Unitek adhesive and Transbond XT 3M resin were used. The samples were preserved to 37°C during 24 hr and submited to tangential forces with the Instron Universal machine 1.0 mm/min speed load strength resistance debonding. Also the Adhesive Remanent Index (ARI) test was made, evaluating the bracket base and the bicuspid surface. All the bracket SEM images were processed with AutoCAD to determine the enamel detached area. The average value was 6.86 MPa (SD ± 3.2 MPa). ARI value 1= 63.3%, value 2= 20%, value 3= 13.3% and 33% presented value 0. All those samples with dental enamel loss, presented different situations as fractures, ledges, horizontal, and vertical loss in some cases, and some scratch lines. There is no association between the debonding resistance and enamel presence. Less than half of the remanent adhesive on the dental enamel was present in most of the samples when the ARI test was applied. When the resin area increases, the debonding resistance also increases, and when the enamel loss increases, the resin free metallic area of the bracket base decreases in the debonding. © 2017 Wiley Periodicals, Inc.

Surface phenomena revealed by in situ imaging: studies from adhesion, wear and cutting

Science.gov (United States)

Viswanathan, Koushik; Mahato, Anirban; Yeung, Ho; Chandrasekar, Srinivasan

2017-03-01

Surface deformation and flow phenomena are ubiquitous in mechanical processes. In this work we present an in situ imaging framework for studying a range of surface mechanical phenomena at high spatial resolution and across a range of time scales. The in situ framework is capable of resolving deformation and flow fields quantitatively in terms of surface displacements, velocities, strains and strain rates. Three case studies are presented demonstrating the power of this framework for studying surface deformation. In the first, the origin of stick-slip motion in adhesive polymer interfaces is investigated, revealing a intimate link between stick-slip and surface wave propagation. Second, the role of flow in mediating formation of surface defects and wear particles in metals is analyzed using a prototypical sliding process. It is shown that conventional post-mortem observation and inference can lead to erroneous conclusions with regard to formation of surface cracks and wear particles. The in situ framework is shown to unambiguously capture delamination wear in sliding. Third, material flow and surface deformation in a typical cutting process is analyzed. It is shown that a long-standing problem in the cutting of annealed metals is resolved by the imaging, with other benefits such as estimation of energy dissipation and power from the flow fields. In closure, guidelines are provided for profitably exploiting in situ observations to study large-strain deformation, flow and friction phenomena at surfaces that display a variety of time-scales.

Application of SEM/EDS to environmental geochemistry of heavy metals

Directory of Open Access Journals (Sweden)

Mateja Gosar

2009-06-01

Full Text Available Heavy metals represent a ubiquitous constituent of the near-surface environment, present in widely varyingconcentrations that typically have little impact on human behaviour and health. However, the mining of metals anduse of these metals in industrial processes has produced significant anthropogenic inputs of metals to both localand global environments. As such, a rigorous overview of the current accumulation of heavy metals and knowledgeof mineralogy of heavy metal-bearing phases is important for understanding their stability, solubility, mobility,bioavailability and toxicity. These data are of fundamental importance for environmental risk assessment and evaluationof future scenarios. Since conventional geochemical analyses provide limited information, other analyticalmethods have to be utilized for the characterisation of heavy metal-bearing phases. Significant analytical methodfor identification and characterisation of heavy metals in environmental media is a scanning electron microscopecoupled with energy dispersive X-ray spectrometer (SEM/EDS, an apparatus for qualitative and semi-quantitative chemical analysis at microne level, newly introduced to Geological Survey of Slovenia. Use of SEM/EDS was already introduced to environmental studies world-wide. In Slovenia, SEM/EDS analyses of environmental media werefirstly carried out on the Meža River stream sediments and snow deposits from Ljubljana urban area.Heavy metal-bearing phases in the Meža River stream sediments were apportioned to three source areas: Mežica mining/smelting area (geogenic-technogenic origin, Ravne ironworks area (technogenic origin and the Meža River catchment area (geogenic origin, which corresponds to data obtained by conventional geochemical and multivariate statistical methods. Airborne particles, identified in urban snow deposits, were interpreted as geogenic particles, represented by fragments of heavy metal-bearing minerals, and technogenic particles that

Using a university characterization facility to educate the public about microscopes: light microscopes to SEM

Science.gov (United States)

Healy, Nancy; Henderson, Walter

2015-10-01

The National Nanotechnology Infrastructure Network (NNIN)1is an integrated partnership of 14 universities across the US funded by NSF to support nanoscale researchers. The NNIN education office is located at the Institute of Electronics and Nanotechnology at the Georgia Institute of Technology. At Georgia Tech we offer programs that integrate the facility and its resources to educate the public about nanotechnology. One event that has proved highly successful involves using microscopes in our characterization suite to educate a diverse audience about a variety of imaging instruments. As part of the annual Atlanta Science Festival (ATLSF)2 we provided an event entitled: "What's all the Buzz about Nanotechnology?" which was open to the public and advertised through a variety of methods by the ATLSF. During the event, we provided hands-on demos, cleanroom tours, and activities with three of our microscopes in our recently opened Imaging and Characterization Facility: 1. Keyence VHX-600 Digital Microscope; 2. Hitachi SU823 FE-SEM; and 3. Hitachi TM 3000. During the two hour event we had approximately 150 visitors including many families with school-aged children. Visitors were invited to bring a sample for scanning with the TM-3000. This paper will discuss how to do such an event, lessons learned, and visitor survey results.

A novel method of estimating dose responses for polymer gels using texture analysis of scanning electron microscopy images.

Directory of Open Access Journals (Sweden)

Cheng-Ting Shih

Full Text Available Polymer gels are regarded as a potential dosimeter for independent validation of absorbed doses in clinical radiotherapy. Several imaging modalities have been used to convert radiation-induced polymerization to absorbed doses from a macro-scale viewpoint. This study developed a novel dose conversion mechanism by texture analysis of scanning electron microscopy (SEM images. The modified N-isopropyl-acrylamide (NIPAM gels were prepared under normoxic conditions, and were administered radiation doses from 5 to 20 Gy. After freeze drying, the gel samples were sliced for SEM scanning with 50×, 500×, and 3500× magnifications. Four texture indices were calculated based on the gray level co-occurrence matrix (GLCM. The results showed that entropy and homogeneity were more suitable than contrast and energy as dose indices for higher linearity and sensitivity of the dose response curves. After parameter optimization, an R (2 value of 0.993 can be achieved for homogeneity using 500× magnified SEM images with 27 pixel offsets and no outlier exclusion. For dose verification, the percentage errors between the prescribed dose and the measured dose for 5, 10, 15, and 20 Gy were -7.60%, 5.80%, 2.53%, and -0.95%, respectively. We conclude that texture analysis can be applied to the SEM images of gel dosimeters to accurately convert micro-scale structural features to absorbed doses. The proposed method may extend the feasibility of applying gel dosimeters in the fields of diagnostic radiology and radiation protection.

Repeated Structural Imaging Reveals Nonlinear Progression of Experience-Dependent Volume Changes in Human Motor Cortex.

Science.gov (United States)

Wenger, Elisabeth; Kühn, Simone; Verrel, Julius; Mårtensson, Johan; Bodammer, Nils Christian; Lindenberger, Ulman; Lövdén, Martin

2017-05-01

Evidence for experience-dependent structural brain change in adult humans is accumulating. However, its time course is not well understood, as intervention studies typically consist of only 2 imaging sessions (before vs. after training). We acquired up to 18 structural magnetic resonance images over a 7-week period while 15 right-handed participants practiced left-hand writing and drawing. After 4 weeks, we observed increases in gray matter of both left and right primary motor cortices relative to a control group; 3 weeks later, these differences were no longer reliable. Time-series analyses revealed that gray matter in the primary motor cortices expanded during the first 4 weeks and then partially renormalized, in particular in the right hemisphere, despite continued practice and increasing task proficiency. Similar patterns of expansion followed by partial renormalization are also found in synaptogenesis, cortical map plasticity, and maturation, and may qualify as a general principle of structural plasticity. Research on human brain plasticity needs to encompass more than 2 measurement occasions to capture expansion and potential renormalization processes over time. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Recent Advances on In Situ SEM Mechanical and Electrical Characterization of Low-Dimensional Nanomaterials.

Science.gov (United States)

Jiang, Chenchen; Lu, Haojian; Zhang, Hongti; Shen, Yajing; Lu, Yang

2017-01-01

In the past decades, in situ scanning electron microscopy (SEM) has become a powerful technique for the experimental study of low-dimensional (1D/2D) nanomaterials, since it can provide unprecedented details for individual nanostructures upon mechanical and electrical stimulus and thus uncover the fundamental deformation and failure mechanisms for their device applications. In this overview, we summarized recent developments on in situ SEM-based mechanical and electrical characterization techniques including tensile, compression, bending, and electrical property probing on individual nanostructures, as well as the state-of-the-art electromechanical coupling analysis. In addition, the advantages and disadvantages of in situ SEM tests were also discussed with some possible solutions to address the challenges. Furthermore, critical challenges were also discussed for the development and design of robust in situ SEM characterization platform with higher resolution and wider range of samples. These experimental efforts have offered in-depth understanding on the mechanical and electrical properties of low-dimensional nanomaterial components and given guidelines for their further structural and functional applications.

Recent Advances on In Situ SEM Mechanical and Electrical Characterization of Low-Dimensional Nanomaterials

Directory of Open Access Journals (Sweden)

Chenchen Jiang

2017-01-01

Full Text Available In the past decades, in situ scanning electron microscopy (SEM has become a powerful technique for the experimental study of low-dimensional (1D/2D nanomaterials, since it can provide unprecedented details for individual nanostructures upon mechanical and electrical stimulus and thus uncover the fundamental deformation and failure mechanisms for their device applications. In this overview, we summarized recent developments on in situ SEM-based mechanical and electrical characterization techniques including tensile, compression, bending, and electrical property probing on individual nanostructures, as well as the state-of-the-art electromechanical coupling analysis. In addition, the advantages and disadvantages of in situ SEM tests were also discussed with some possible solutions to address the challenges. Furthermore, critical challenges were also discussed for the development and design of robust in situ SEM characterization platform with higher resolution and wider range of samples. These experimental efforts have offered in-depth understanding on the mechanical and electrical properties of low-dimensional nanomaterial components and given guidelines for their further structural and functional applications.

Correlative scanning electron and confocal microscopy imaging of labeled cells coated by indium-tin-oxide

KAUST Repository

Rodighiero, Simona

2015-03-22

Confocal microscopy imaging of cells allows to visualize the presence of specific antigens by using fluorescent tags or fluorescent proteins, with resolution of few hundreds of nanometers, providing their localization in a large field-of-view and the understanding of their cellular function. Conversely, in scanning electron microscopy (SEM), the surface morphology of cells is imaged down to nanometer scale using secondary electrons. Combining both imaging techniques have brought to the correlative light and electron microscopy, contributing to investigate the existing relationships between biological surface structures and functions. Furthermore, in SEM, backscattered electrons (BSE) can image local compositional differences, like those due to nanosized gold particles labeling cellular surface antigens. To perform SEM imaging of cells, they could be grown on conducting substrates, but obtaining images of limited quality. Alternatively, they could be rendered electrically conductive, coating them with a thin metal layer. However, when BSE are collected to detect gold-labeled surface antigens, heavy metals cannot be used as coating material, as they would mask the BSE signal produced by the markers. Cell surface could be then coated with a thin layer of chromium, but this results in a loss of conductivity due to the fast chromium oxidation, if the samples come in contact with air. In order to overcome these major limitations, a thin layer of indium-tin-oxide was deposited by ion-sputtering on gold-decorated HeLa cells and neurons. Indium-tin-oxide was able to provide stable electrical conductivity and preservation of the BSE signal coming from the gold-conjugated markers. © 2015 Wiley Periodicals, Inc.

The advancement of the built environment research through employment of structural equation modeling (SEM)

Science.gov (United States)

Wasilah, S.; Fahmyddin, T.

2018-03-01

The employment of structural equation modeling (SEM) in research has taken an increasing attention in among researchers in built environment. There is a gap to understand the attributes, application, and importance of this approach in data analysis in built environment study. This paper intends to provide fundamental comprehension of SEM method in data analysis, unveiling attributes, employment and significance and bestow cases to assess associations amongst variables and constructs. The study uses some main literature to grasp the essence of SEM regarding with built environment research. The better acknowledgment of this analytical tool may assist the researcher in the built environment to analyze data under complex research questions and to test multivariate models in a single study.

Are the evidences of forensic entomology preserved in ethanol suitable for SEM studies?