Bibliografie tematiche / Computer controlled scanning electron microscopy

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Letteratura scientifica selezionata sul tema "Computer controlled scanning electron microscopy"

Autore: Grafiati

Pubblicato: 4 giugno 2021

Ultima modifica: 9 febbraio 2022

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Articoli di riviste sul tema "Computer controlled scanning electron microscopy"

Ruscitto, Daniel M., Elizabeth Cleland, Lauraine Denault e David A. Wark. "Mineral Classification Using Computer-Controlled Scanning Electron Microscopy". Microscopy and Microanalysis 20, S3 (agosto 2014): 664–65. http://dx.doi.org/10.1017/s1431927614005042.

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Prutton, M., M. M. El Gomati, J. C. Greenwood, P. G. Kennyr, I. R. Barkshire e J. C. Dee. "Multispectral Surface Analytical Microscopy: A Third-Generation Scanning Auger Electron Microscope". Proceedings, annual meeting, Electron Microscopy Society of America 48, n. 2 (12 agosto 1990): 384–85. http://dx.doi.org/10.1017/s0424820100135526.

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The quantitative interpretation of scanning Auger electron microscope (SAM) images has been shown to require the use of multi-spectral imaging of the surface under study. In a multi-spectral analytical microscope (MULSAM) a set of maps (bands) is acquired from the same area of a sample using scattered electrons with different kinetic energies as well as other signals from the sample such as current flowing to ground, the conventional SEM signal and characteristic x-rays. The resulting set of bands is a multi-spectral image which can be processed using models of the electron scattering in the sample and statistical transforms well known in LANDSAT imaging technology. The processed images can separate the mixed effects of topography, surface chemical inhomogeneity and bulk chemical composition fluctuations occurring in the bands of raw data.A computer controlled, UHV, energy analysing, scanning electron SEM will be described in this paper. The microscope contains facilities for collecting up to 23 256 by 256 pixel image bands from the same area of the sample.

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Poelt, P., M. Schmied, I. Obernberger, T. Brunner e J. Dahl. "Automated analysis of submicron particles by computer-controlled scanning electron microscopy". Scanning 24, n. 2 (6 dicembre 2006): 92–100. http://dx.doi.org/10.1002/sca.4950240207.

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Barlow, S. B. "Scanning Electron Microscopy at a Distance: A Nuts-and-Bolts Discussion". Microscopy and Microanalysis 5, S2 (agosto 1999): 528–29. http://dx.doi.org/10.1017/s1431927600015968.

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Not everyone can afford to own and operate a scanning electron microscope. Everyone can, however, access images and instruments in a variety of ways, depending on the objective. Remote access capability is a result of recent developments in desktop computers, software, and the World Wide Web. Some of these developments and some suggestions for future resource development will be reviewed here.With the arrival of commercially available, digitally controlled SEMs in the 1980s, it became possible to control microscope operation with a desktop computer and the appropriate software. By connecting a desktop computer to the microscope via the Internet or dedicated data lines such as ATMs, remote control of microscopes became a reality. Although analog microscopes are not as readily controllable over the Internet, their video data stream is easily captured, digitized, and dispatched to remote observers using low-cost consumer video conferencing programs. These approaches enable users at one location to observe their samples in a microscope located elsewhere. However, transfer rates over the Internet fluctuate wildly depending on network traffic, at times making remote access or control almost impossible. Dedicated data lines ensure a relatively stable transfer rate, but at a significantly higher cost.

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Sitzmann, B., M. Kendall, J. Watt e I. Williams. "Characterisation of airborne particles in London by computer-controlled scanning electron microscopy". Science of The Total Environment 241, n. 1-3 (ottobre 1999): 63–73. http://dx.doi.org/10.1016/s0048-9697(99)00326-5.

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Kindratenko, Volodymyr V., Piet J. M. Van Espen, Boris A. Treiger e R. E. Van Grieken. "Fractal Dimensional Classification of Aerosol Particles by Computer-Controlled Scanning Electron Microscopy". Environmental Science & Technology 28, n. 12 (novembre 1994): 2197–202. http://dx.doi.org/10.1021/es00061a031.

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Yang, Yang, Zhang Bingyang, Jiang Fuming, Hui Senxing e Yin Qingrui. "Computer-controlled image acquisition and processed system for scanning electron -acoustic microscopy". Ferroelectrics 196, n. 1 (maggio 1997): 215–18. http://dx.doi.org/10.1080/00150199708224165.

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Kim, D., e P. K. Hopke. "Classification of Individual Particles Based on Computer-Controlled Scanning Electron Microscopy Data". Aerosol Science and Technology 9, n. 2 (gennaio 1988): 133–51. http://dx.doi.org/10.1080/02786828808959201.

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Cprek, Nick, Naresh Shah, Frank E. Huggins e Gerald P. Huffman. "Computer-controlled scanning electron microscopy (CCSEM) investigation of quartz in coal fly ash". Fuel Processing Technology 88, n. 11-12 (dicembre 2007): 1017–20. http://dx.doi.org/10.1016/j.fuproc.2007.06.007.

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Cprek, Nick, Naresh Shah, Frank E. Huggins e Gerald P. Huffman. "Distinguishing Respirable Quartz in Coal Fly Ash Using Computer-Controlled Scanning Electron Microscopy". Environmental Science & Technology 41, n. 10 (maggio 2007): 3475–80. http://dx.doi.org/10.1021/es062938j.

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Più fonti

Tesi sul tema "Computer controlled scanning electron microscopy"

Coleman, Kristen. "Detection of silica particles in lung tissue of non-occupationally exposed individuals by computer controlled scanning electron microscopy". Thesis, University of Iowa, 2013. https://ir.uiowa.edu/etd/1572.

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For years crystalline silica has been recognized as an occupational hazard of the dusty trades with exposures resulting in silicosis. As recently as 1997, IARC categorized the respirable portion of crystalline silica as a Grade 1 human carcinogen indicating that silica may be implicated in the development of lung cancer. Evidence in the literature indicates that silica may be not only an occupational hazard, but an environmental hazard as well, with patients with no known exposure showing measurable quantities of silica within cancerous tissue samples. This study aims to establish a methodology using computer-controlled scanning electron microscopy to examine silica content in lung cancer tissue. Furthermore, demonstrating that silica is not evenly distributed within the tissue will establish the need to use automated full scanning techniques, such as CCSEM, in order to guarantee that the analysis is not subject to random sampling error or researcher driven error, which may be rendering the traditional random sampling of zones for analysis under-representative of silica concentration in the tissue.

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Ruess, Frank Joachim Physics Faculty of Science UNSW. "Atomically controlled device fabrication using STM". Awarded by:University of New South Wales. Physics, 2006. http://handle.unsw.edu.au/1959.4/24855.

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We present the development of a novel, UHV-compatible device fabrication strategy for the realisation of nano- and atomic-scale devices in silicon by harnessing the atomic-resolution capability of a scanning tunnelling microscope (STM). We develop etched registration markers in the silicon substrate in combination with a custom-designed STM/ molecular beam epitaxy system (MBE) to solve one of the key problems in STM device fabrication ??? connecting devices, fabricated in UHV, to the outside world. Using hydrogen-based STM lithography in combination with phosphine, as a dopant source, and silicon MBE, we then go on to fabricate several planar Si:P devices on one chip, including control devices that demonstrate the efficiency of each stage of the fabrication process. We demonstrate that we can perform four terminal magnetoconductance measurements at cryogenic temperatures after ex-situ alignment of metal contacts to the buried device. Using this process, we demonstrate the lateral confinement of P dopants in a delta-doped plane to a line of width 90nm; and observe the cross-over from 2D to 1D magnetotransport. These measurements enable us to extract the wire width which is in excellent agreement with STM images of the patterned wire. We then create STM-patterned Si:P wires with widths from 90nm to 8nm that show ohmic conduction and low resistivities of 1 to 20 micro Ohm-cm respectively ??? some of the highest conductivity wires reported in silicon. We study the dominant scattering mechanisms in the wires and find that temperature-dependent magnetoconductance can be described by a combination of both 1D weak localisation and 1D electron-electron interaction theories with a potential crossover to strong localisation at lower temperatures. We present results from STM-patterned tunnel junctions with gap sizes of 50nm and 17nm exhibiting clean, non-linear characteristics. We also present preliminary conductance results from a 70nm long and 90nm wide dot between source-drain leads which show evidence of Coulomb blockade behaviour. The thesis demonstrates the viability of using STM lithography to make devices in silicon down to atomic-scale dimensions. In particular, we show the enormous potential of this technology to directly correlate images of the doped regions with ex-situ electrical device characteristics.

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Snella, Michael T. "Drift correction for scanning-electron microscopy". Thesis, Massachusetts Institute of Technology, 2010. http://hdl.handle.net/1721.1/62605.

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Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2010.
This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Cataloged from student submitted PDF version of thesis.
Includes bibliographical references (p. 91-92).
Scanning electron micrographs at high magnification (100,000x and up) are distorted by motion of the sample during image acquisition, a phenomenon called drift. We propose a method for correcting drift distortion in images obtained on scanning electron and other scanned-beam microscopes by registering a series of images to create a drift-free composite. We develop a drift-distortion model for linear drift and use it as a basis for an affine correction between images in the sequence. The performance of our correction method is evaluated with simulated datasets and real datasets taken on both scanning electron and scanning helium-ion microscopes; we compare performance against translation only correction. In simulation, we exhibit a 12.5 dB improvement in SNR of our drift-corrected composite compared to a non-aligned composite, and a 3 dB improvement over translation correction. A more modest 0.4 dB improvement is measured on the real image sets compared to translation correction alone.
by Michael T. Snella.
M.Eng.

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Chang, Michael Ming Yuen. "A computer-controlled system in transmission electron microscopy". Thesis, University of Cambridge, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.292941.

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Yuan, Biao. "Direct measurement of thicknesses, volumes or compositions of nanomaterials by quantitative atomic number contrast in high-angle annular dark-field scanning transmission electron microscopy". Doctoral diss., University of Central Florida, 2012. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5586.

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The sizes, shapes, volumes and compositions of nanoparticles are very important parameters determining many of their properties. Efforts to measure these parameters for individual nanoparticles and to obtain reliable statistics for a large number of nanoparticles require a fast and reliable method for 3-D characterization. In this dissertation, a direct measurement method for thicknesses, volumes or compositions of nanomaterials by quantitative atomic number contrast in High-Angle Annular Dark-Field (HAADF) Scanning Transmission Electron Microscopy (STEM) is presented. A HAADF detector collects electrons scattered incoherently to high angles. The HAADF signal intensity is in first-order approximation proportional to the sample thickness and increases with atomic number. However, for larger sample thicknesses this approach fails. A simple description for the thickness dependence of the HAADF-STEM contrast has been developed in this dissertation. A new method for the calibration of the sensitivity of the HAADF detector for a FEI F30 transmission electron microscope (TEM) is developed in this dissertation. A nearly linear relationship of the HAADF signal with the electron current is confirmed. Cross sections of multilayered samples provided by TriQuint Semiconductors in Apopka, FL, for contrast calibration were obtained by focused ion-beam (FIB) preparation yielding data on the interaction cross section per atom. To obtain an absolute intensity calibration of the HAADF-STEM intensity, Convergent Beam Electron Diffraction (CBED) was performed on Si single crystals. However, for samples prepared by the focused ion beam technique, CBED often significantly underestimates the sample thickness. Multislice simulations from Dr. Kirkland's C codes are used for comparison with experimental results. TEM offers high lateral resolution, but contains little or no information on the thickness of samples. Thickness maps in energy-filtered TEM (EFTEM), CBED and tilt series are so far the only methods to determine thicknesses of particles in TEM. In this work I have introduced the use of wedge-shaped multilayer samples prepared by FIB for the calibration of HAADF-STEM contrasts. This method yields quantitative contrast data as a function of sample thickness. A database with several pure elements and compounds has been compiled, containing experimental data on the fraction of electrons scattered onto the HAADF detector for each nanometer of sample thickness. The use of thick samples reveals an increased signal at the interfaces of high- and low-density materials. This effect can be explained by the transfer of scattered electrons from the high density material across the interface into the less-absorbing low-density material. The calibrations were used to determine concentration gradients in nanoscale Fe-Pt multilayers as well as thicknesses and volumes of individual Au-Fe, Pt, and Ag nanoparticles. Volumes of nanoparticles with known composition can be determined with accuracy better than 15%. Porosity determination of materials becomes available with this method as shown in an example of porous Silicon.?
ID: 031001418; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Adviser: Helge H. Heinrich.; Co-adviser: Yongho Sohn.; Title from PDF title page (viewed June 17, 2013).; Thesis (Ph.D.)--University of Central Florida, 2012.; Includes bibliographical references (p. 116-130).
Ph.D.
Doctorate
Materials Science Engineering
Engineering and Computer Science
Materials Science and Engineering

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ANDRADE, ALEXANDRE B. de. "Desenvolvimento de conjuntos eletrodo-membrana-eletrodo para células a combustível a membrana trocadora de prótons (PEMFC) por impressão à tela". reponame:Repositório Institucional do IPEN, 2008. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11713.

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Made available in DSpace on 2014-10-09T12:55:01Z (GMT). No. of bitstreams: 0
Made available in DSpace on 2014-10-09T14:05:59Z (GMT). No. of bitstreams: 0
Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

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Vishweswaraiah, Srinivas. "NON-DESTRUCTIVE MICROSTRUCTURAL EVALUATION OF YTTRIA STABILIZED ZIRCONIA, NICKEL ALUMINIDES AND THERMAL BARRIER COATINGS USING ELECTROCHEMICAL IMPEDANCE SPECTROSCOPY". Master's thesis, University of Central Florida, 2004. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4463.

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There has been an urge for increasing the efficiency in advanced gas turbine engines. To fulfill these needs the inlet gas temperatures should be increased in the gas turbine engines, thermal barrier coatings (TBCs) have gained significant applications in increasing the gas inlet temperatures. Insulating characteristics of ceramic TBCs allow the operation at up to 150~250 °C higher gas temperatures. Because of the severe turbine engine operating conditions that include high temperature, steep temperature gradient, thermal cycling, oxidation and hot-corrosion, TBCs can fail by spallation at the interface between the metal and ceramic. The lack of understanding in failure mechanisms and their prediction warrant a development of non-destructive evaluation technique that can monitor the quality and degradation of TBCs. In addition, the development of NDE technique must be based on a robust correlation to the characteristics of TBC failure. The objective of this study is to develop electrochemical impedance spectroscopy (EIS) as a Non-destructive evaluation (NDE) technology for application to TBCs. To have a better understanding of the multilayer TBCs using EIS they were divided into individual layers and EIS were performed on them. The individual layers included polycrystalline ZrO2-7~8 wt.%Y?O? (YSZ) (topcoat) of two different densities were subjected to sintering by varying the sintering temperature and holding time for three different thickness and hot extruded NiAl alloy buttons which were subjected to isothermal oxidation with varying temperature and time. NiAl is as similar to the available commercial bondcoats used in TBCs. Then degradation monitoring with electrolyte penetration was carried out on electron beam physical vapor deposited (EB-PVD) TBCs as a function of isothermal exposure. Quality control for air plasma sprayed TBCs were carried out as a function of density, thickness and microstructure. Dense vertically cracked TBCs were tested as a function of vertical crack density and thickness. Electrochemical impedance response was acquired from all specimens at room temperature and analyzed with an AC equivalent circuit based on the impedance response as well as multi-layered structure and micro-constituents of specimens. Physical and microstructural features of these specimens were also examined by optical and electron microscopy. The EIS measurement was carried out in a three-electrode system using a standard Flat Cell (K0235) from Princeton Applied Research and IM6e BAS ZAHNER TM frequency response analyzer. The electrolyte employed in this investigation was 0.01M (molar) potassium Ferri/Ferro Cyanide [(K?Fe(CN)?/K?Fe(CN)?x3H?O)]. The thickness and density were directly related to the resistance and capacitance of the polycrystalline YSZ with varying thickness and open pores. As the effective thickness of the YSZ increased with sintering time and temperature, the resistance of the YSZ (R[subscript YSZ]) increased proportionally. The variation in capacitance of YSZ (C[subscript YSZ]) with respect to the change in porosity/density and thickness was clearly detected by EIS. The samples with high porosity (less dense) exhibited large capacitance, C[subscript YSZ]), compared to those with less porosity (high density), given similar thickness. Cracking in the YSZ monoliths resulted in decrease of resistance and increase in capacitance and this was related to the electrolyte penetration. Growth and spallation of TGO scale on NiAl alloys during isothermal oxidation at various temperatures and holding time was also correlated with resistance and capacitance of the TGO scale. With an increase in the TGO thickness, the resistance of the TGO (R[subscript TGO]) increased and capacitance of the TGO (C[subscriptTGO]) decreased. This trend in the resistance and capacitance of the TGO changed after prolonged heat treatment. This is because of the spallation of the TGO scale from the metal surface. The parabolic growth of TGO during high temperature oxidation was inversely proportional to the capacitance of TGO, excluding the abrupt changes associated with the failure. As a function of isothermal exposure for EB -PVD TBCs, initial increase in the resistance of YSZ with thermal exposure was observed perhaps due to the high temperature sintering of YSZ. The parabolic growth of TGO during high temperature oxidation was inversely proportional to the capacitance of TGO. An explanation based on electrolyte penetration into sub-critical damage is proposed for the gradual decrease in the resistances of YSZ and TGO with prolonged thermal exposure. Observation of exposed metallic bond coat surface on the fracture surface, which readily provides conduction, was related to the abrupt and large increase in the capacitance of YSZ and TGO. A direct relation between the resistance of the YSZ (R[subscript YSZ]) and density of the YSZ was observed for APS TBCs with varying topcoat density. APS TBCs with varying topcoat chemistry and thickness were tested and directly related to resistance of topcoat. With the increase in the topcoat thickness, the capacitance decreased and the resistance increased. The higher values of C[subscript CAT] and R[subscript CAT] compared to that of CYSZ and RYSZ were related to the higher dielectric constant and resistivity of CaTiO?. Dense vertically cracked TBCs were tested with varying crack density were tested and the variation in the resistance was related indirectly to the cracks and directly to the difference in the thickness of the topcoat. EB-PVD TBCs with varying density (dense and columnar) were tested and the variation in resistance was attributed to the dense structure and columnar structure of the topcoat with columnar structure having lower resistance because of more electrolyte penetration through the columnar structure. From this study, EIS showed a potential as a NDE technique for quality assurance and lifetime remain assessment of TBCs. Future work should continue on developing a mathematical model to study the impedance curves and come up with a model for individual layers of TBC and then sum them up to get the multilayered TBC response. The flexible instrument probe of EIS needs to be designed and tested for field evaluation of TBCs.
M.S.
Department of Mechanical, Materials and Aerospace Engineering
Engineering and Computer Science
Mechanical, Materials and Aerospace Engineering

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Johann, Victoria Anne. "Development and Implementation of an Automated SEM-EDX Routine for Characterizing Respirable Coal Mine Dust". Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/73367.

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This thesis describes the development and use of a computer-automated microscopy routine for characterization of respirable dust particles from coal mines. Respirable dust in underground coal mining environments has long been known to pose an occupational health hazard for miners. Typically following years of exposure, coal workers' pneumoconiosis (CWP) and silicosis are the most common disease diagnoses. Although dramatic reductions in CWP and silicosis cases were achieved across the US between about 1970-1999 through a combination of regulatory dust exposure limits, improved ventilation and dust abatement practices, a resurgence in disease incidence has been noted more recently – particularly in parts of Appalachia. To shed light on this alarming trend and allow for better understanding of the role of respirable dust in development of disease, more must be learned about the specific characteristics of dust particles and occupational exposures. This work first sought to develop an automated routine for the characterization of respirable dust using scanning electron microscopy with energy dispersive x-ray (SEM-EDX). SEM-EDX is a powerful tool that allows determination of the size, shape, and chemistry of individual particles, but manual operation of the instrument is very time consuming and has the potential to introduce user bias. The automated method developed here provides for much more efficient analysis – with a data capture rate that is typically 25 times faster than that of the manual method on which it was based – and also eliminates bias between users. Moreover, due to its efficiency and broader coverage of a dust sample, it allows for characterization of a larger and more representative number of particles per sample. The routine was verified using respirable dust samples generated from known materials commonly observed in underground coal mines in the central Appalachian region, as well as field samples collected in this region. This effort demonstrated that particles between about 1-9μm were accurately classified with respect to defined chemical categories, and suggested that analysis of 500 particles across a large area of a sample filter generally provides representative results. The automated SEM-EDX routine was then used to characterize a total of 210 respirable dust samples collected in eight Appalachian coal mines. The mines were located in three distinct regions (i.e., northern, mid-central and south-central Appalachia), which differed in terms of primary mining method, coal seam thickness and mining height, and coal and/or rock mineralogy. Results were analyzed to determine whether number distributions of particle size, aspect ratio, and chemistry classification vary between and within distinct mine regions, and by general sampling location categories (i.e., intake, feeder, production, return). Key findings include: 1) Northern Appalachian mines have relatively higher fractions of coal, carbonate, and heavy mineral particles than the two central Appalachian regions, whereas central Appalachian mines have higher fractions of quartz and alumino-silicate particles. 2) Central Appalachian mines tended to have more mine-to-mine variations in size, shape, and chemistry distributions than northern Appalachian mines. 3) With respect to particle size, samples collected in locations in the production and return categories have the highest percentages of very small particles (i.e., 0.94-2.0μm), followed by the feeder and then the intake locations. 4) With respect to particle shape, samples collected in locations in the production and return categories have higher fractions of particles with moderate (i.e., length is 1.5 to 3x width) to relatively high aspect ratios (i.e., length is greater than 3x width) compared to feeder and intake samples. 5) Samples with relatively high fractions of alumino-silicates have higher fractions of particles with moderate aspect ratios than samples with low alumino-silicate fractions. 6) Samples with relatively high fractions of quartz particles have higher fractions of particles with moderate aspect ratios and higher percentages of very small particles than samples with no identified quartz particles. 7) Samples with high fractions of carbonates have higher percentages of particles with relatively low aspect ratios (i.e., length and width are similar) than samples with no identified carbonate particles.
Master of Science

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Sow, Libasse. "Approche couplée expérimentation - modélisation multi-échelle pour la détermination du comportement mécanique des graves routières traitées aux liants : Application à la valorisation des Mâchefers d'Incinération de Déchêts Non Dangereux". Thesis, Rennes, INSA, 2018. http://www.theses.fr/2018ISAR0001/document.

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Dans ce travail, il est question d'étudier la faisabilité d'une valorisation en techniques routières de granulats de Mâchefers d'Incinération des Dèchets Non Dangereux (MIDND). Cette étude se base en premier lieu sur une analyse expérimentale ayant permis d'obtenir leurs propriétés élastiques. Ces propriétés servent de données d'entrée à une modélisation multi-échelle hiérarchique développée pour étudier le comportement mécanique de graves base de MIDND traitées aux liants (ciment et bitume). La campagne expérimentale originale sur des particules de mâchefers a permis de les cartographier au Microscope Electronique à Balayage (MEB Pour ces particules, des modules d'élasticité moyens réduits variant de 15 à 68 GPa ont été trouvés par le biais de tests d'indentation en appliquant méthode de «Olivier and Pharr ». Les analyses chimiques ponctuelles qualitatives (EDS) effectuées ont permis d'obtenir la composition chimique des granulats de mâchefers. Partant d'une granulométrie de particules de MIDND 0/25 qui a fait l'objet d'une étude expérimentale [BEC 07], nous avons mis en place des modèles numériques 3D de grave routière traitée aux liants dans des Volumes Elémentaires Représentatifs (VER). Ces modèles sont basés sur une stratégie de modélisation dite « multi-échelles » hiérarchique. Deux types de liant sont étudiés : le ciment CEM 1 42,5 R et le bitume de [NGU 08). Pour les deux types de liant, les agrégats traités ont été décomposés en deux VER : sub-mesoscopique (0/6) et mesoscopique (6/25). Une application à valorisation des MIDND en techniques routières est faite dans les deux cas. Avec un traitement à 3% de ciment, une campagne de simulations numériques "Laboratoire virtuel" a été menée. A l'échelle sub-mesoscopique, des simulations multiaxiales menées sur le VER, ont conduit à l'obtention des paramètres permettant d'alimenter un modèle d'endommagement plastique utilisé à l'échelle mesoscopique pour différents degrés d'hydratation. A l'échelle mesoscopique, les caractéristiques mécaniques de la grave routière traitée au ciment, habituellement déterminées par le biais d'expérimentations, ont été retrouvées. La modélisation développée a ensuite été validée e comparant nos résultats numériques et quelques résultats expérimentaux de [BEC 07]. Avec un traitement à 5% de bitume, des tests de relaxation de contraintes ont été effectués aux deux échelles ct ont permis d'obtenir les propriétés thermo-rhéologiques de la grave de mâchefers traités au bitume : les modules de relaxation sont exprimés sous la forme de séries de Prony à une température de référence de 0 °C ; par ailleurs, les constantes de la loi Williams-Landel-Ferry (WLF) pour décrire le comportement thermo- rhéologiquement simple sont identifiées. Les séries de Prony sont obtenues par l'intermédiaire des modules élastiques normalisés. Les constantes de 1 WLF obtenues sont C 1 = 20 °C-1 ct C2 = 130 °C. La validation des paramètres identifiés a été faite en comparant les réponses du matériau hétérogène de grave-bitume et celles d'un matériau homogène à qui nous avons donné les propriétés identifiées tirées du matériau hétérogène
In this work, the feasibility of a valorisation in road engineering of non-hazardous waste incineration bottom ash aggregates (NHWI) is investigated. This study is first based on an experimental determination of the elastic properties of the bottom ash particles. These properties serve as input data for hierarchical multi-scale modelling developed to study the mechanical behaviour of aggregates treated with binders (cement and bitumen). The original experimental campaign on the bottom ash particles allowed them to be mapped to the Scanning Electron Microscope (SEM). For the particles, a mean reduced modulus of elasticity in between 15 and 68 GPa was found by means of indentation tests and applying the "Olivier and Phan method. The chemical analysis of the aggregates was obtained using qualitative point chemical analyzes (OHS). Based on a 0/25 particle size distribution of NHWI, which was the subject of an experimental study [BEC 07] , we have implemented two 30 models < road materials treated with binders in Representative Elementary Volumes (REV). These models are based on a hierarchical multi-scale modelling strategy. Two types of binder are studied: cement CEM I 42.5 R and bitumen of [NGU 08]. For both types of binder, the treated aggregates we divided into two REV, at respectively the sub-mesoscale (0/6 mm) and the mesoscale (6/25 mm). An application to the valorisation of NHWI bottom ashes in road engineering is studied in both cases. With a 3% cement treatment, a numerical simulation campaign "Virtual Laboratory" was conducted. At the sub-mesoscale, the input parameters for the Concrete Damaged Plasticity Model used at the mesoscale are determined. At the mesoscale, the mechanical characteristics of the road materials usually determined through experiments have been found. The developed simulation strategy has been validated by comparing our numerical results and son experimental results of [BEC 07]. With a 5% bitumen treatment, stress relaxation tests carried out at the two scales enable one to obtain the thermo-rheological properties of the Bitumen Bound Gravel. These properties are the Prony series at a reference temperature of 0°C and the Williams-Landei- Ferry (WLF) law constants. Prony series are obtained by means of standardized elastic moduli. The obtained WLF law constants are Cl = 20 °C-1 and C2 = 130 °C. The numeric simulations have been validated by comparing the responses of heterogeneous and corresponding homogeneous materials

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CRAESMEYER, GABRIEL R. "Tratamento de efluente contendo urânio com zeólita magnética". reponame:Repositório Institucional do IPEN, 2013. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10578.

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IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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Libri sul tema "Computer controlled scanning electron microscopy"

Sarid, Dror. Exploring scanning probe microscopy with mathematica. 2^a ed. Weinheim: Wiley-VCH, 2007.

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Pfefferkorn, Conference (6th 1987 Niagara Falls Ont ). Image and signal processing in electron microscopy: Proceedings of the 6th Pfefferkorn Conference, held April 28 to May 2, 1987, at Niagara Falls, Canada. AMF O'Hare, IL: Scanning Microscopy International, 1988.

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Egon, Marx, e National Institute of Standards and Technology (U.S.), a cura di. User's manual for the program MONSEL-1: Monte Carlo simulation of SEM signals for linewidth metrology. Gaithersburg, MD: U.S. Dept. of Commerce, Technology Administration, National Institute of Standards and Technology, 1994.

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Advances in Electronics and Electron Physics (Advances in Imaging and Electron Physics). Academic Pr, 1985.

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Hawkes, Peter W. Advances in Electronics and Electron Physics (Advances in Imaging and Electron Physics). Academic Press, 1990.

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Hawkes, Peter W. Advances in Electronics and Electron Physics (Advances in Imaging and Electron Physics). Academic Press, 1990.

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Hawkes, Peter W. Advances in Electronics and Electron Physics (Advances in Imaging and Electron Physics). Academic Press, 1986.

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Advances in Electronics and Electron Physics (Advances in Imaging and Electron Physics). Academic Press, 1991.

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Hawkes, Peter W. Advances in Electronics and Electron Physics (Advances in Imaging and Electron Physics). Academic Press, 1985.

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Capitoli di libri sul tema "Computer controlled scanning electron microscopy"

Benson, Steven A., Donald P. McCollor, Kurt E. Eylands, Jason D. Laumb e Robert R. Jensen. "Characterization of Particulate Matter with Computer-Controlled Scanning Electron Microscopy". In Environmental Challenges and Greenhouse Gas Control for Fossil Fuel Utilization in the 21st Century, 29–42. Boston, MA: Springer US, 2002. http://dx.doi.org/10.1007/978-1-4615-0773-4_3.

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Sznitman, Raphael, Aurelien Lucchi, Marco Cantoni, Graham Knott e Pascal Fua. "Flash Scanning Electron Microscopy". In Medical Image Computing and Computer-Assisted Intervention – MICCAI 2013, 413–20. Berlin, Heidelberg: Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-40760-4_52.

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Lyman, Charles E., Joseph I. Goldstein, Alton D. Romig, Patrick Echlin, David C. Joy, Dale E. Newbury, David B. Williams et al. "Computer-Aided Imaging". In Scanning Electron Microscopy, X-Ray Microanalysis, and Analytical Electron Microscopy, 90–95. Boston, MA: Springer US, 1990. http://dx.doi.org/10.1007/978-1-4613-0635-1_17.

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Lyman, Charles E., Joseph I. Goldstein, Alton D. Romig, Patrick Echlin, David C. Joy, Dale E. Newbury, David B. Williams et al. "Computer-Aided Imaging". In Scanning Electron Microscopy, X-Ray Microanalysis, and Analytical Electron Microscopy, 296–305. Boston, MA: Springer US, 1990. http://dx.doi.org/10.1007/978-1-4613-0635-1_46.

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Newbury, Dale E., David C. Joy, Patrick Echlin, Charles E. Fiori e Joseph I. Goldstein. "Computer-Aided Imaging and Interpretation". In Advanced Scanning Electron Microscopy and X-Ray Microanalysis, 181–241. Boston, MA: Springer US, 1986. http://dx.doi.org/10.1007/978-1-4757-9027-6_5.

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K R, Padmavathi, Ramakrishnan R, Karthikeyan L e ChezhianBabu S. "Mechanical Characterization of Aluminium-Titania Metal Matrix Composites". In Intelligent Systems and Computer Technology. IOS Press, 2020. http://dx.doi.org/10.3233/apc200214.

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Researchers investigated the mechanical properties of Aluminium Metal Matrix Composites (AMMC) with several reinforcements and negligible work has been administered on analysing the mechanical characteristics of AMMC with rutile nanotitania reinforcement material. Metal matrix composite with Aluminium 6061 metallic element as matrix material and nanotitania as reinforcement with 0.5, 1.0, 1.5 and 2.0 weight percentages was fabricated through stir casting method followed by die casting and heat treatment. Consequent exploration on mechanical characteristics viz. micro hardness, tensile, compressive and impact strength were carried out. The fabricated samples were examined using scanning electron microscopy and analysed. The outcomes exhibited enhanced mechanical characteristics for 1.0 weight percentage nanotitania reinforced aluminium6061 metal matrix composite material.

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Atti di convegni sul tema "Computer controlled scanning electron microscopy"

Hunt, Andrew, e Jane A. Entwistle. "SOURCE ATTRIBUTION OF PB IN SIX SOILS FROM MITROVICA, REPUBLIC OF KOSOVO AT THE INDIVIDUAL PARTICLE LEVEL USING COMPUTER CONTROLLED SCANNING ELECTRON MICROSCOPY (CCSEM)". In GSA Annual Meeting in Denver, Colorado, USA - 2016. Geological Society of America, 2016. http://dx.doi.org/10.1130/abs/2016am-287790.

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Gupta, Abhishek, Volkan Patoglu e Marcia K. O'Malley. "Vision Based Force Sensing for Nanorobotic Manipulation". In ASME 2006 International Mechanical Engineering Congress and Exposition. ASMEDC, 2006. http://dx.doi.org/10.1115/imece2006-15111.

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Over the last decade, considerable interest has been generated in building and manipulating nanoscale structures. Applications of nanomanipulation include study of nanoparticles, molecules, DNA and viruses, and bottom-up nanoassembly. We propose a Nanomanipulation System using the Zyvex S100 nanomanipulator, which operates within a scanning electron microscope (SEM), as its primary component. The primary advantage of the S100 setup over standard scanning probe microscopy based nanomanipulators is the ability to see the object during manipulation. Relying on visual feedback alone to control the nanomanipulator is not preferable due to perceptual limitations of depth and contact within the SEM. To improve operator performance over visual feedback alone, an impedance-controlled bilateral teleoperation setup is envisioned. Lack of on-board force sensors on the S100 system is the primary hindrance in the realization of the proposed architecture. In this paper, we present a computer vision based force sensing scheme. The advantages of this sensing strategy include its low cost and lack of requirement of hardware modification(s). Force sensing is implemented using an atomic force microscopy (AFM) probe attached to the S100 end-effector. Deformation of the cantilever probe is monitored using a Hough transform based algorithm. These deformations are mapped to corresponding end-effector forces following the Euler-Bernoulli beam mechanics model. The forces thus sensed can be used to provide force-feedback to the operator through a master manipulator.

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Liang, Jianyu, e Zhenhai Xia. "Synthesis and Properties of Cobalt Nanowires". In 2007 First International Conference on Integration and Commercialization of Micro and Nanosystems. ASMEDC, 2007. http://dx.doi.org/10.1115/mnc2007-21298.

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Understanding the structure and properties of metal nanowires is critical for the atomic-scale manipulation, design and application of those materials. Currently, active research on structure and behavior of various metallic nanowires has been carried out by computer simulation. Much experimental work has been done for synthesizing various metal nanowires by many different methods. To experimentally explore the mechanism of the behavior of and the development of structures in the nanowires, it is desirable to have the capability of synthesis various metal nanowires with controlled size, length, uniformity and aspect ratio. It is also desirable to further process those metal nanowires to engineer their properties. In our study, a template assisted fabrication method has been employed to fabricate various metal nanowire arrays, including cobalt, iron and nickel. This fabrication method offers us command over the size and length of the nanowires with excellent uniformity. Heat treatments were used to further process the metal nanowires. The structure of cobalt nanowire array has been investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Mechanical properties of the metal nanowire array will be investigated through nanoindentation and atomic force microscopy (AFM).

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Ninomiya, Yoshihiko, e Atsushi Sato. "Sintering Behavior of Coal Ash Build Up on Ceramic Filters in a Hot Gas Filtration System". In 17th International Conference on Fluidized Bed Combustion. ASMEDC, 2003. http://dx.doi.org/10.1115/fbc2003-127.

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To understand agglomeration phenomena of ash particles in a hot gas ceramic filter system, actual tests were carried out on candle filters with a 4MWth pressurized internally circulating fluidized bed boiler (PICFB) pilot plant. Coal ashes build up on the ceramic filters were analyzed by computer controlled scanning electron microscopy (CCSEM) and thermomechanical analyzer (TMA). The dust cake taken at 750°C did not show any sign of bridging or cleaning difficulty, while those at 950°C showed some difficulty in cleaning because of ash bridging between the adjacent ceramic filters. The initial deformation temperatures of the non-bridge dust were about 750 to 800°C. The index of R2O/(Al2O3+SiO2) (R2O = Na2O or K2O) for the non-bridge dust cake showed in the range of 1 to 25wt%, and the particle size of the potassium rich particles was in the range of 0.5 to 2.2μm. However, the index for the bridge cake approached to below 5% and the particle size of the potassium rich particles shifted to the larger range of 2.2 to 10μm. It was observed that weak sintering takes place by the reaction of potassium rich particles and the ash particles that adjoins the particles.

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LaCoursiere, Marissa, Daryush K. Aidun, Pier Marzocca e Howard Lee. "An Experimental Study Investigating the Corrosion Behavior of Cu-Ni Alloys in Waters Treated and Untreated With Anti-Corrosives". In ASME 2009 International Mechanical Engineering Congress and Exposition. ASMEDC, 2009. http://dx.doi.org/10.1115/imece2009-13341.

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This paper discusses an experimental study on how water quality affects the corrosion rate of Cu-Ni Alloys, such as those used within a heat exchanger system. Various types of water suitable for the heat exchanger operation have been tested to predict the duration during which corrosion would become a risk. Since corrosion is governed by electrochemistry, an electrochemical experimental setup was designed, consisting of a three-electrode electrochemical cell designed to simulate the on-site state and conditions of a 90–10 Cu-Ni tube bundle inside the heat exchanger. The working electrode in use is a 90-10 Cu-Ni Rotating Cylinder Electrode (RCE). The electrolyte solution was varied with different pH values, temperature and compositions. The corrosion rate was measured by use of the Tafel method. Experiments were performed with two solutions; De-Ionized water and Tap water. Further experimentation with anti-corrosives was also performed. All measurements were produced using a G300 Gamry® Potentiostat (computer controlled) conjugated with two general purpose electrochemical softwares: Gamry Framework® and Gamry Echem Analyst®. Trends of the corrosion rate as a function of pH and temperature were analyzed. Field Emission Scanning Electron Microscope (FE-SEM) tests have also been performed to determine the products, methods and elemental effects of the corrosion. Results and discussions are provided with pertinent conclusions.

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Kumrai-Woodruff, Raoul, e Qing Wang. "Temperature Control to Increase Inter-Layer Bonding Strength in Fused Deposition Modelling". In ASME 2020 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/detc2020-22342.

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Abstract Fused Deposition Modelling (FDM) provides opportunities for new development in numerous areas. Z-directional anisotropic strength caused by weak inter-layer bonding has been recognized as the reason for limited industry adoption of FDM. This paper aims to investigate increasing the Z-directional strength of Acrylonitrile Butadiene Styrene (ABS) using a temperature controlled print environment. The ambient temperature during printing was increased to reduce heat transfer from the print, thereby encouraging more polymer chain inter-diffusion between layers. Dogbone specimens were printed at ambient print temperatures between 24.8°C and 71.2°C and tensile tests were performed. A thermal camera was used to identify heat loss in the FDM process. Ultimate tensile strength was found to increase by a maximum of 104% compared to open enclosure printing. A stylus profiler and scanning electron microscopy were used to compare the quality of the inter-layer bonds, suggesting that additional polymer inter-diffusion occurred at hotter ambient temperatures. A weak positive relationship was found between ambient air temperature and inter-layer part strength. Further experimentation could provide scope to determine an ideal ambient print temperature that is likely to be dependent on print settings and the printer used.

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Bassani, Roberto, Enrico Ciulli, Enrico Manfredi, Salvatore Manconi, Alessandro Polacco e Giovanni Pugliese. "Experimental Study on Wear and Fracture in Aeronautical Gear Transmissions". In ASME 8th Biennial Conference on Engineering Systems Design and Analysis. ASMEDC, 2006. http://dx.doi.org/10.1115/esda2006-95720.

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This work presents some of the results obtained from an extensive experimental test campaign performed at the Department of Mechanical Nuclear and Production Engineering (DIMNP) of Pisa University with the partnership of Avio Propulsione Aerospaziale S.p.A. This test campaign, that is still being performed, is concerned with the characterization of teeth damage in high performance gear transmissions, such as aeronautical ones, characterized by high levels of velocity and load. Damage detection and monitoring have been pursued during all the tests in order to achieve a better understanding of causes and evolution of teeth damage. Moreover, to investigate the effects of different parameters on teeth damage, tests with different load, velocity, teeth geometry, materials and surface finishing, have been performed. The surface conditions of the gear teeth have been investigated using in particular two different instruments: a computer-controlled stylus profilometer able to perform 3D investigations and a scanning electron microscope (SEM) recently provided by a software for surface reconstruction. Qualitative and quantitative changes in surface roughness have been detected. Besides the experimental activity, numerical analyses have been also started for finding theoretical criteria for surface damage prediction; some few obtained results are presented. Due to the vastness of the work performed, only a survey of the main results obtained till now is presented in the paper.

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Kockentiedt, Stephen, Klaus Tönnies, Erhardt Gierke, Nico Dziurowitz, Carmen Thim e Sabine Plitzko. "Improved Automatic Recognition of Engineered Nanoparticles in Scanning Electron Microscopy Images". In International Conference on Computer Vision Theory and Applications. SCITEPRESS - Science and and Technology Publications, 2015. http://dx.doi.org/10.5220/0005299003370344.

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Takuwa, Tsuyoshi, e Ichiro Naruse. "Effect of Mineral Matters in Coal on Formation Behaviors of Particulate Matter and Alkali Metal Compounds During Coal Combustion". In 18th International Conference on Fluidized Bed Combustion. ASMEDC, 2005. http://dx.doi.org/10.1115/fbc2005-78039.

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Combustion tests for 2 types of coal (SC and BT coals), which have similar combustion performance and main fraction in the ash compositions, were conducted, using an electrically heated drop tube furnace. The burning particles were sampled by the Low Pressure Impactor (LPI) and analyzed concentration of alkali metal in the collected particles. Furthermore, they were observed by a scanning electron microscope (SEM) to discuss formation behaviors of the fine particles during combustion. In order to elucidate the relationship between formation characteristics of fine particulates during combustion and coal types, analysis of included and excluded mineral particles in the raw coals was conducted by a Computer Controlled SEM (CCSEM). Additionally, the composition analysis of the mineral particles in the raw coal was also carried out, using an energy dispersive X-ray spectrometer (EDS). As a result, the particle size distribution of ash particulates formed was different each other for two types of coal. Especially for the fine particulates with the size of less than 1 μm, the result for SC coal showed much more fine particulates formation than those for BT coal. Sodium compounds were enriched in the fine particulates for both the coals. Shapes of the fine particles with the size less than 1 μm for both the coals were spherical. For the coarse particles, however, spherical particles were observed for only SC coal. This difference was due to difference of the characteristics of mineral particles in the raw coals. The CCSEM analysis indicated that the excluded mineral matters, which tended to fragment during combustion, were contained more in SC coal than those in BT coal. This is the reason why SC coal forms more fine particulates during combustion than BT coal. From the EDS analysis, moreover, content of sodium in the excluded minerals of SC coal was higher than that of BT coal. This result suggests that SC coal tends to form the spherical fine particulates, in which the sodium compounds are enriched, during combustion.

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Saifujjaman, Md, Kwangkook Jeong e Shinku Lee. "Modeling for Mineral Redistribution of Coal Blending During Pulverized Coal Combustion". In ASME 2018 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/imece2018-87834.

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This paper represents an analytical model for predicting mineral particle redistribution of coal blending during pulverized coal (PC) combustion in a pulverized coal-fired boiler. The objective of this research is to develop a computer program to perform the mass balance of total minerals after transformation during combustion. A MATLAB code was developed for coal blending mineral redistribution from single coal mineral redistribution in modular approach based on relative Hardgrove Grindability Index (HGI) of coals. The calculations of the single coal number of ash particles before and after combustion both for excluded and included minerals from the single coal proximate analysis, Malvern analysis, Computer Controlled Scanning Electron Microscopy (CCSEM) analysis, density and composition analysis were designed in a submodule. Utilizing single coal sub-module, the calculations of coal blending number of ash particles before and after combustion both for excluded and included minerals were designed in a module of MATLAB code. The blending modeling was designed to blend up to five sub-bituminous coals. Calculations were made for typical boiler combustion conditions ranging from 1,500K to 2,500K as flame temperature. The organically-associated ash content or mineral grains of each coal smaller than 1 micrometer was not included in the calculation of redistribution modeling. Coal particle fragmentation of blended coal was considered as same as single coal and size dependent phenomena. Partial coalescence model was assumed as more likely to occur. Blended coal was assumed to follow additive rule applied to mineral mass percentage based on sizes and mineral phase regardless grinding of coals separately or after blending if the HGI difference between highest and lowest HGI of coals arranged in ascending order stands within five. The modeling was demonstrated for KPU: AVRA and AVRA: Solntsevsky with specific blending ratio 80:20 and 20:80 respectively. The model for blended coal was validated by the mass balance of minerals before and after combustion. The resulting simplified particle size distribution of mass fraction of KPU: AVRA shows good agreement with experimental results of Kentucky #9 coal because of having a larger amount of included minerals of KPU coal. The model for blended coal mineral redistribution before and after combustion will be developed for the HGI difference between highest and lowest HGI of coals arranged in ascending order becomes greater than five and validated by minerals mass balance before and after combustion. This modeling will be used to predict number of mineral particles and its sizes that is a key parameter as to predict the problems like fouling and slagging and the related reduction of boiler efficiency. The results from this study will be further carried out to investigate ash deposition rates in post-boiler heat exchangers.

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