Articoli di riviste: "Electron microscope"

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Möller, Lars, Gudrun Holland e Michael Laue. "Diagnostic Electron Microscopy of Viruses With Low-voltage Electron Microscopes". Journal of Histochemistry & Cytochemistry 68, n. 6 (21 maggio 2020): 389–402. http://dx.doi.org/10.1369/0022155420929438.

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Diagnostic electron microscopy is a useful technique for the identification of viruses associated with human, animal, or plant diseases. The size of virus structures requires a high optical resolution (i.e., about 1 nm), which, for a long time, was only provided by transmission electron microscopes operated at 60 kV and above. During the last decade, low-voltage electron microscopy has been improved and potentially provides an alternative to the use of high-voltage electron microscopy for diagnostic electron microscopy of viruses. Therefore, we have compared the imaging capabilities of three low-voltage electron microscopes, a scanning electron microscope equipped with a scanning transmission detector and two low-voltage transmission electron microscopes, operated at 25 kV, with the imaging capabilities of a high-voltage transmission electron microscope using different viruses in samples prepared by negative staining and ultrathin sectioning. All of the microscopes provided sufficient optical resolution for a recognition of the viruses tested. In ultrathin sections, ultrastructural details of virus genesis could be revealed. Speed of imaging was fast enough to allow rapid screening of diagnostic samples at a reasonable throughput. In summary, the results suggest that low-voltage microscopes are a suitable alternative to high-voltage transmission electron microscopes for diagnostic electron microscopy of viruses.

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Gauvin, Raynald, e Steve Yue. "The Observation of NBC Precipitates In Steels In The Nanometer Range Using A Field Emission Gun Scanning Electron Microscope". Microscopy and Microanalysis 3, S2 (agosto 1997): 1243–44. http://dx.doi.org/10.1017/s1431927600013106.

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The observation of microstructural features smaller than 300 nm is generally performed using Transmission Electron Microscopy (TEM) because conventional Scanning Electron Microscopes (SEM) do not have the resolution to image such small phases. Since the early 1990’s, a new generation of microscopes is now available on the market. These are the Field Emission Gun Scanning Electron Microscope with a virtual secondary electron detector. The field emission gun gives a higher brightness than those obtained using conventional electron filaments allowing enough electrons to be collected to operate the microscope with incident electron energy, E0, below 5 keV with probe diameter smaller than 5 nm. At 1 keV, the electron range is 60 nm in aluminum and 10 nm in iron (computed using the CASINO program). Since the electron beam diameter is smaller than 5 nm at 1 keV, the resolution of these microscopes becomes closer to that of TEM.

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Ross, Frances M. "Materials Science in the Electron Microscope". MRS Bulletin 19, n. 6 (giugno 1994): 17–21. http://dx.doi.org/10.1557/s0883769400036691.

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This issue of the MRS Bulletin aims to highlight the innovative and exciting materials science research now being done using in situ electron microscopy. Techniques which combine real-time image acquisition with high spatial resolution have contributed to our understanding of a remarkably diverse range of physical phenomena. The articles in this issue present recent advances in materials science which have been made using the techniques of transmission electron microscopy (TEM), including holography, scanning electron microscopy (SEM), low-energy electron microscopy (LEEM), and high-voltage electron microscopy (HVEM).The idea of carrying out dynamic experiments involving real-time observation of microscopic phenomena has always had an attraction for materials scientists. Ever since the first static images were obtained in the electron microscope, materials scientists have been interested in observing processes in real time: we feel that we obtain a true understanding of a microscopic phenomenon if we can actually watch it taking place. The idea behind “materials science in the electron microscope” is therefore to use the electron microscope—with its unique ability to image subtle changes in a material at or near the atomic level—as a laboratory in which a remarkable variety of experiments can be carried out. In this issue you will read about dynamic experiments in areas such as phase transformations, thin-film growth, and electromigration, which make use of innovative designs for the specimen, the specimen holder, or the microscope itself. These articles speak for themselves in demonstrating the power of real-time analysis in the quantitative exploration of reaction mechanisms.The first transmission electron microscopes operated at low accelerating voltages, up to about 100 kV. This placed a severe limitation on the thickness of foils that could be examined: Heavy elements, for example, had to be made into foils thinner than 0.1 μm. It was felt that any phenomenon whose “mean free path” was comparable to the foil thickness would be significantly affected by the foil surfaces, and therefore would be unsuitable for study in situ. However, technology quickly generated ever higher accelerating voltages, culminating in the giant 3 MeV electron microscopes. At these voltages, electrons can penetrate materials as thick as 6–9 μm for light elements such as Si and Al, and 1 μm for very heavy ones such as Au and U.

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Kordesch, Martin E. "Introduction to emission electron microscopy for the in situ study of surfaces". Proceedings, annual meeting, Electron Microscopy Society of America 51 (1 agosto 1993): 506–7. http://dx.doi.org/10.1017/s0424820100148368.

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The Photoelectron Emission Microscope (PEEM) and Low Energy Electron Microscope (LEEM) are parallel-imaging electron microscopes with highly surface-sensitive image contrast mechanisms. In PEEM, the electron yield at the illumination wavelength determines image contrast, in LEEM, the intensity of low energy (< 100 eV) electrons back-diffracted from the surface, as well as interference effects, are responsible for image contrast. Mirror Electron Microscopy is also possible with the LEEM apparatus. In MEM, no electron penetration into the solid occurs, and an image of surface electronic potentials is obtained.While the emission microscope techniques named above are not high resolution methods, the unique contrast mechanisms, the ability to use thick single crystal samples, their compatibility with uhv surface science methods and new material-growth methods, coupled with real-time imaging capability, make them very useful.These microscopes do not depend on scanning probes, and some are compatible with pressures up to 10-3 Torr and specimen temperatures above 1300K.

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O'Keefe, Michael A., John H. Turner, John A. Musante, Crispin J. D. Hetherington, A. G. Cullis, Bridget Carragher, Ron Jenkins et al. "Laboratory Design for High-Performance Electron Microscopy". Microscopy Today 12, n. 3 (maggio 2004): 8–17. http://dx.doi.org/10.1017/s1551929500052093.

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Since publication of the classic text on the electron microscope laboratory by Anderson, the proliferation of microscopes with field emission guns, imaging filters and hardware spherical aberration correctors (giving higher spatial and energy resolution) has resulted in the need to construct special laboratories. As resolutions iinprovel transmission electron microscopes (TEMs) and scanning transmission electron microscopes (STEMs) become more sensitive to ambient conditions. State-of-the-art electron microscopes require state-of-the-art environments, and this means careful design and implementation of microscope sites, from the microscope room to the building that surrounds it. Laboratories have been constructed to house high-sensitive instruments with resolutions ranging down to sub-Angstrom levels; we present the various design philosophies used for some of these laboratories and our experiences with them. Four facilities are described: the National Center for Electron Microscopy OAM Laboratory at LBNL; the FEGTEM Facility at the University of Sheffield; the Center for Integrative Molecular Biosciences at TSRI; and the Advanced Microscopy Laboratory at ORNL.

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KONNO, Mitsuru, Toshie YAGUCHI e Takahito HASHIMOTO. "Transmission Electron Microscop and Scanning Transmission Electron Microscope". Journal of the Japan Society of Colour Material 79, n. 4 (2006): 147–51. http://dx.doi.org/10.4011/shikizai1937.79.147.

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Watson, John H. L. "In the beginning there were electrons". Proceedings, annual meeting, Electron Microscopy Society of America 50, n. 2 (agosto 1992): 1068–69. http://dx.doi.org/10.1017/s0424820100129978.

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Electrons have undoubtedly been around since the beginning of time, but not until the first quarter of the twentieth century, following the work of deBroglie on the dual nature of the electron, Busch's hypothesis that an electron beam could be focussed by an axially symmetric magnetic field, and Davisson & Germer's and Thomson's independent demonstrations of electron diffraction, did microscopists take seriously the possibility of a microscope utilizing electrons and magnetic fields. The first attempts at building electron microscopes were made in Europe but the resolution in the often blurred and distorted electron images was not much better than that achieved by light microscopy, so that a general opposition to funding the development of electron microscopes began to emerge. In 1935 E.F. Burton, Chairman of the Department of Physics at the University of Toronto began a program of electron optical research with his graduate student Cecil E. Hall, building emission microscopes.

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Ai, R. "A Microscope-Compatible Auger Electron Spectrometer". Proceedings, annual meeting, Electron Microscopy Society of America 49 (agosto 1991): 992–93. http://dx.doi.org/10.1017/s0424820100089275.

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With the recent development of ultra-high vacuum high resolution electron microscopes (UHV-HREM), electron microscopes have become valuable tools for surface studies. Techniques such as surface profile image, surface sensitive plane view, and reflection electron microscopy have been developed to take full advantage of the atomic resolution of HREM to study surface structures. However a complete surface study requires information on both the surface structure and surface chemistry. Therefore in order to turn an electron microscope into a real surface analytical tool, the challenge is to develop a microscopecompatible, surface sensitive tool for in-situ surface chemical analysis.

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Kersker, M., C. Nielsen, H. Otsuji, T. Miyokawa e S. Nakagawa. "The JSM-890 ultra high resolution Scanning Electron Microscope". Proceedings, annual meeting, Electron Microscopy Society of America 47 (6 agosto 1989): 88–89. http://dx.doi.org/10.1017/s0424820100152410.

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Historically, ultra high spatial resolution electron microscopy has belonged to the transmission electron microscope. Today, however, ultra high resolution scanning electron microscopes are beginning to challenge the transmission microscope for the highest resolution.To accomplish high resolution surface imaging, not only is high resolution required. It is also necessary that the integrity of the specimen be preserved, i.e., that morphological changes to the specimen during observation are prevented. The two major artifacts introduced during observation are contamination and beam damage, both created by the small, high current-density probes necessary for high signal generation in the scanning instrument. The JSM-890 Ultra High Resolution Scanning Microscope provides the highest resolution probe attainable in a dedicated scanning electron microscope and its design also accounts for the problematical artifacts described above.Extensive experience with scanning transmission electron microscopes lead to the design considerations of the ultra high resolution JSM- 890.

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Schatten, G., J. Pawley e H. Ris. "Integrated microscopy resource for biomedical research at the university of wisconsin at madison". Proceedings, annual meeting, Electron Microscopy Society of America 45 (agosto 1987): 594–97. http://dx.doi.org/10.1017/s0424820100127451.

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The High Voltage Electron Microscopy Laboratory [HVEM] at the University of Wisconsin-Madison, a National Institutes of Health Biomedical Research Technology Resource, has recently been renamed the Integrated Microscopy Resource for Biomedical Research [IMR]. This change is designed to highlight both our increasing abilities to provide sophisticated microscopes for biomedical investigators, and the expansion of our mission beyond furnishing access to a million-volt transmission electron microscope. This abstract will describe the current status of the IMR, some preliminary results, our upcoming plans, and the current procedures for applying for microscope time.The IMR has five principal facilities: 1.High Voltage Electron Microscopy2.Computer-Based Motion Analysis3.Low Voltage High-Resolution Scanning Electron Microscopy4.Tandem Scanning Reflected Light Microscopy5.Computer-Enhanced Video MicroscopyThe IMR houses an AEI-EM7 one million-volt transmission electron microscope.

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Graef, M. De, N. T. Nuhfer e N. J. Cleary. "Implementation Of A Digital Microscopy Teaching Environment". Microscopy and Microanalysis 5, S2 (agosto 1999): 4–5. http://dx.doi.org/10.1017/s1431927600013349.

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The steady evolution of computer controlled electron microscopes is dramatically changing the way we teach microscopy. For today’s microscopy student, an electron microscope may be just another program on the desktop of whatever computer platform he or she uses. This is reflected in the use of the term Desktop Microscopy. The SEM in particular has become a mouse and keyboard controlled machine, and running the microscope is not very different from using a drawing program or a word processor. Transmission electron microscopes are headed in the same direction.While one can debate whether or not it is wise to treat an SEM or a TEM as just another black-box computer program, it is a fact that these machines are here to stay, which means that microscopy educators must adapt their traditional didactic tools and methods. One way to bring electron microscopes into the classroom is through the use of remote control software packages, such as Timbuktu Pro or PC-Anywhere. The remote user essentially opens a window containing the desktop of the microscope control computer and has all functions available. On microscopes with specialized graphics boards, integration of the image and control display for remote operation may not be straightforward, and often requires the purchase of additional graphics boards for the remote machine.

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YAMAMOTO, Shinji, Kyohei UMEMOTO e Ken-ichir YAMASHITA. "Electron Microscope". Journal of The Institute of Electrical Engineers of Japan 133, n. 5 (2013): 298–301. http://dx.doi.org/10.1541/ieejjournal.133.298.

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SATO, Mitsugu. "Electron Microscope". Journal of the Society of Mechanical Engineers 117, n. 1144 (2014): 142–43. http://dx.doi.org/10.1299/jsmemag.117.1144_142.

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Oikawa, Tetsuo. "Electron Microscope". Zairyo-to-Kankyo 41, n. 10 (1992): 690–97. http://dx.doi.org/10.3323/jcorr1991.41.690.

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Kersker, Michael M. "A History of ESEM in 2.5 Chapters". Microscopy and Microanalysis 7, S2 (agosto 2001): 774–75. http://dx.doi.org/10.1017/s1431927600029949.

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Microscopy has always been concerned with the observation of samples in their natural states. The earliest instruments, optical microscopes, did not interfere with the samples which were under observation due to the pervasive presence of visible light in the normal evolution of these entities. Man and science persisted in this direction until Ruska in 1933 invented the electron microscope and the real world changed forever (see MSA Rudenberg for an enlightening description of the early days of man's understanding of the electron and the subsequent invention of the electron microscope). The earliest electron beam instruments were single vacuum chamber entities. As single chamber designs, every element in the optical path was under vacuum. These included the electron gun, the lens and coils, recording film, and of course, the specimen itself. The purpose of the vacuum was quite obvious...to eliminate the scattering of the electrons due to the presence of gas.

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Dahmen, Ulrich, Rolf Erni, Velimir Radmilovic, Christian Ksielowski, Marta-Dacil Rossell e Peter Denes. "Background, status and future of the Transmission Electron Aberration-corrected Microscope project". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 367, n. 1903 (28 settembre 2009): 3795–808. http://dx.doi.org/10.1098/rsta.2009.0094.

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The strong interaction of electrons with small volumes of matter make them an ideal probe for nanomaterials, but our ability to fully use this signal in electron microscopes remains limited by lens aberrations. To bring this unique advantage to bear on materials research requires a sample space for electron scattering experiments in a tunable electron-optical environment. This is the vision for the Transmission Electron Aberration-corrected Microscope (TEAM) project, which was initiated as a collaborative effort to re-design the electron microscope around aberration-correcting optics. The resulting improvements in spatial, spectral and temporal resolution, the increased space around the sample and the possibility of exotic electron-optical settings will enable new types of experiments. This contribution will give an overview of the TEAM project and its current status, illustrate the performance of the TEAM 0.5 instrument, with highlights from early applications of the machine, and outline future scientific opportunities for aberration-corrected microscopy.

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BAUM, RUDY. "Light microscope rivals electron microscope". Chemical & Engineering News 71, n. 35 (30 agosto 1993): 22–23. http://dx.doi.org/10.1021/cen-v071n035.p022.

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O’Keefe, M. A., J. Taylor, D. Owen, B. Crowley, K. H. Westmacott, W. Johnston e U. Dahmen. "Remote On-Line Control of a High-Voltage in situ Transmission Electron Microscope with A Rational User Interface". Proceedings, annual meeting, Electron Microscopy Society of America 54 (11 agosto 1996): 384–85. http://dx.doi.org/10.1017/s0424820100164386.

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Remote on-line electron microscopy is rapidly becoming more available as improvements continue to be developed in the software and hardware of interfaces and networks. Scanning electron microscopes have been driven remotely across both wide and local area networks. Initial implementations with transmission electron microscopes have targeted unique facilities like an advanced analytical electron microscope, a biological 3-D IVEM and a HVEM capable of in situ materials science applications. As implementations of on-line transmission electron microscopy become more widespread, it is essential that suitable standards be developed and followed. Two such standards have been proposed for a high-level protocol language for on-line access, and we have proposed a rational graphical user interface. The user interface we present here is based on experience gained with a full-function materials science application providing users of the National Center for Electron Microscopy with remote on-line access to a 1.5MeV Kratos EM-1500 in situ high-voltage transmission electron microscope via existing wide area networks. We have developed and implemented, and are continuing to refine, a set of tools, protocols, and interfaces to run the Kratos EM-1500 on-line for collaborative research. Computer tools for capturing and manipulating real-time video signals are integrated into a standardized user interface that may be used for remote access to any transmission electron microscope equipped with a suitable control computer.

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J. H., Youngblom, Wilkinson J. e Youngblom J.J. "Telepresence Confocal Microscopy". Microscopy and Microanalysis 6, S2 (agosto 2000): 1164–65. http://dx.doi.org/10.1017/s1431927600038319.

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The advent of the Internet has allowed the development of remote access capabilities to a growing variety of microscopy systems. The Materials MicroCharacterization Collaboratory, for example, has developed an impressive facility that provides remote access to a number of highly sophisticated microscopy and microanalysis instruments. While certain types of microscopes, such as scanning electron microscopes, transmission electron microscopes, scanning probe microscopes, and others have already been established for telepresence microscopy, no one has yet reported on the development of similar capabilities for the confocal laser scanning microscope.At California State University-Stanislaus, home of the CSUPERB (California State University Program for Education and Research in Biotechnology) Confocal Microscope Core Facility, we have established a remote access confocal laser scanning microscope facility that allows users with virtually any type of computer platform to connect to our system. Our Leica TCS NT confocal system, with an interchangeable upright (DMRXE) and inverted microscope (DMIRBE) set up,

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Ruska, Ernst. "The development of the electron microscope and of electron microscopy". Reviews of Modern Physics 59, n. 3 (1 luglio 1987): 627–38. http://dx.doi.org/10.1103/revmodphys.59.627.

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Ruska, Ernst. "The development of the electron microscope and of electron microscopy". Bioscience Reports 7, n. 8 (1 agosto 1987): 607–29. http://dx.doi.org/10.1007/bf01127674.

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Brama, Elisabeth, Christopher J. Peddie, Gary Wilkes, Yan Gu, Lucy M. Collinson e Martin L. Jones. "ultraLM and miniLM: Locator tools for smart tracking of fluorescent cells in correlative light and electron microscopy". Wellcome Open Research 1 (13 dicembre 2016): 26. http://dx.doi.org/10.12688/wellcomeopenres.10299.1.

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In-resin fluorescence (IRF) protocols preserve fluorescent proteins in resin-embedded cells and tissues for correlative light and electron microscopy, aiding interpretation of macromolecular function within the complex cellular landscape. Dual-contrast IRF samples can be imaged in separate fluorescence and electron microscopes, or in dual-modality integrated microscopes for high resolution correlation of fluorophore to organelle. IRF samples also offer a unique opportunity to automate correlative imaging workflows. Here we present two new locator tools for finding and following fluorescent cells in IRF blocks, enabling future automation of correlative imaging. The ultraLM is a fluorescence microscope that integrates with an ultramicrotome, which enables ‘smart collection’ of ultrathin sections containing fluorescent cells or tissues for subsequent transmission electron microscopy or array tomography. The miniLM is a fluorescence microscope that integrates with serial block face scanning electron microscopes, which enables ‘smart tracking’ of fluorescent structures during automated serial electron image acquisition from large cell and tissue volumes.

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Liu, J., e J. R. Ebner. "Nano-Characterization of Industrial Heterogeneous Catalysts". Microscopy and Microanalysis 4, S2 (luglio 1998): 740–41. http://dx.doi.org/10.1017/s1431927600023825.

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Catalyst characterization plays a vital role in new catalyst development and in troubleshooting of commercially catalyzed processes. The ultimate goal of catalyst characterization is to understand the structure-property relationships associated with the active components and supports. Among many characterization techniques, only electron microscopy and associated analytical techniques can provide local information about the structure, chemistry, morphology, and electronic properties of industrial heterogeneous catalysts. Three types of electron microscopes are usually used for characterizing industrial supported catalysts: 1) scanning electron microscope (SEM), 2) scanning transmission electron microscope (STEM), and 3) transmission electron microscope (TEM). Each type of microscope has its unique capabilities. However, the integration of all electron microscopic techniques has proved invaluable for extracting useful information about the structure and the performance of industrial catalysts.Commercial catalysts usually have a high surface area with complex geometric structures to enable reacting gases or fluids to access as much of the active surface of the catalyst as possible.

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van der Krift, Theo, Ulrike Ziese, Willie Geerts e Bram Koster. "Computer-Controlled Transmission Electron Microscopy: Automated Tomography". Microscopy and Microanalysis 7, S2 (agosto 2001): 968–69. http://dx.doi.org/10.1017/s1431927600030919.

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The integration of computers and transmission electron microscopes (TEM) in combination with the availability of computer networks evolves in various fields of computer-controlled electron microscopy. Three layers can be discriminated: control of electron-optical elements in the column, automation of specific microscope operation procedures and display of user interfaces. The first layer of development concerns the computer-control of the optical elements of the transmission electron microscope (TEM). Most of the TEM manufacturers have transformed their optical instruments into computer-controlled image capturing devices. Nowadays, the required controls for the currents through lenses and coils of the optical column can be accessed by computer software. The second layer of development is aimed toward further automation of instrument operation. For specific microscope applications, dedicated automated microscope-control procedures are carried out. in this paper, we will discuss our ongoing efforts on this second level towards fully automated electron tomography. The third layer of development concerns virtual- or telemicroscopy. Most telemicroscopy applications duplicate the computer-screen (with accessory controls) at the microscope-site to a computer-screen at another site. This approach allows sharing of equipment, monitoring of instruments by supervisors, as well as collaboration between experts at remote locations.Electron tomography is a three-dimensional (3D) imaging method with transmission electron microscopy (TEM) that provides high-resolution 3D images of structural arrangements. with electron tomography a series of images is acquired of a sample that is tilted over a large angular range (±70°) with small angular tilt increments.

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Gauvin, Raynald, e Pierre Hovington. "On the Microanalysis of Small Precipitates at Low Voltage with a FE-SEM". Microscopy and Microanalysis 5, S2 (agosto 1999): 308–9. http://dx.doi.org/10.1017/s1431927600014860.

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The observation of microstructural features smaller than 300 nm is generally performed using Transmission Electron Microscopy (TEM) because conventional Scanning Electron Microscopes (SEM) do not have the resolution to image such small phases. Since the early 1990’s, a new generation of microscopes is now available on the market. These are the Field Emission Gun Scanning Electron Microscope with a virtual secondary electron detector. The field emission gun gives a higher brightness than those obtained using conventional electron filaments allowing enough electrons to be collected to operate the microscope with incident electron energy, E0, below 5 keV, with probe diameter smaller than 2.5 nm. Furthermore, what gives FE-SEM outstanding resolution is the combination of new magnetic lenses with a virtual secondary electron (SE) detector. The new lenses are designed to reduce the spherical and chromatic aberration coefficients, giving a smaller probe size. Contrary to the conventional systems, the SE detector is located above the objective lens and it becomes a virtual or through-the-lens (TTL) detector. Therefore, the SE image is mostly made up of all SEs of type I, almost eliminating those of type II and III which are generated by the backscattered electrons inside the specimen as well as in the chamber. It has been shown recently that Nb(CN) precipitates in Fe, as small than 10 nm, can be imaged with a FE-SEM Hitachi S-4500 with the TTL detector.

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Williams, Nicola. "Do Microscopes Have Politics? Gendering the Electron Microscope in Laboratory Biological Research". Technology and Culture 64, n. 4 (ottobre 2023): 1159–83. http://dx.doi.org/10.1353/tech.2023.a910999.

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abstract: Objects like microscopes are gendered depending on their context. The introduction of the electron microscope at Leeds University in early 1940s Britain was under the control of high-status physicists, most of whom were men, who regulated its access over and against biologists. Moreover, the microscope required physical strength more associated with men than women, combined with a sound knowledge of physics. This article explores the challenges women encountered including access to scientific instruments when entering post–World War II electron microscopy through Irene Manton's career. It combines techno-political and gendered perspectives on the history of women in science. In particular, the study invites gendered understanding of early biological electron microscopy, at a university world-renowned on the subject, through the lens of one capital intensive microscope.

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Kremer, James R., Paul S. Furcinitti, Eileen O’Toole e J. Richard McIntosh. "Analysis of photographic emulsions for High-Voltage Electron Microscopy". Proceedings, annual meeting, Electron Microscopy Society of America 51 (1 agosto 1993): 452–53. http://dx.doi.org/10.1017/s0424820100148095.

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Characteristics of electron microscope film emulsions, such as the speed, the modulation transfer function, and the exposure dependence of the noise power spectrum, have been studied for electron energies (80-100keV) used in conventional transmission microscopy. However, limited information is available for electron energies in the intermediate to high voltage range, 300-1000keV. Furthermore, emulsion characteristics, such as optical density versus exposure, for new or improved emulsions are usually only quoted by film manufacturers for 80keV electrons. The need for further film emulsion studies at higher voltages becomes apparent when searching for a film to record low dose images of radiation sensitive biological specimens in the frozen hydrated state. Here, we report the optical density, speed and relative resolution of a few of the more popular electron microscope films after exposure to 1MeV electrons.Three electron microscope films, Kodak S0-163, Kodak 4489, and Agfa Scientia 23D56 were tested with a JEOLJEM-1000 electron microscope operating at an accelerating voltage of 1000keV.

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Vidyavati e G. Sathaiah. "Cell division in desmids under scanning electron microscope". Archiv für Hydrobiologie 105, n. 2 (2 maggio 1989): 239–49. http://dx.doi.org/10.1127/archiv-hydrobiol/105/1989/239.

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Youngblom, J. H., J. Wilkinson e J. J. Youngblom. "Telepresence Confocal Microscopy". Microscopy Today 8, n. 10 (dicembre 2000): 20–21. http://dx.doi.org/10.1017/s1551929500054146.

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The advent of the Internet has allowed the development of remote access capabilities to a growing variety of microscopy systems. The Materials MicroCharacterization Collaboratory, for example, has developed an impressive facility that provides remote access to a number of highly sophisticated microscopy and microanalysis instruments, While certain types of microscopes, such as scanning electron microscopes, transmission electron microscopes, scanning probe microscopes, and others have already been established for telepresence microscopy, no one has yet reported on the development of similar capabilities for the confocal laser scanning microscope.

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Kenik, Edward A., e Karren L. More. "SHaRE: Collaborative materials science research". Proceedings, annual meeting, Electron Microscopy Society of America 46 (1988): 804–5. http://dx.doi.org/10.1017/s0424820100106089.

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The Shared Research Equipment (SHaRE) Program provides access to the wide range of advanced equipment and techniques available in the Metals and Ceramics Division of ORNL to researchers from universities, industry, and other national laboratories. All SHaRE projects are collaborative in nature and address materials science problems in areas of mutual interest to the internal and external collaborators. While all facilities in the Metals and Ceramics Division are available under SHaRE, there is a strong emphasis on analytical electron microscopy (AEM), based on state-of-the-art facilities, techniques, and recognized expertise in the Division. The microscopy facilities include four analytical electron microscopes (one 300 kV, one 200 kV, and two 120 kV instruments), a conventional transmission electron microscope with a low field polepiece for examination of ferromagnetic materials, a high voltage (1 MV) electron microscope with a number of in situ capabilities, and a variety of EM support facilities. An atom probe field-ion microscope provides microstructural and elemental characterization at atomic resolution.

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Suga, Hiroshi, Takafumi Fujiwara, Nobuhiro Kanai e Masatoshi Kotera. "Secondary Electron Image Contrast in the Scanning Electron Microscope". Proceedings, annual meeting, Electron Microscopy Society of America 48, n. 1 (12 agosto 1990): 410–11. http://dx.doi.org/10.1017/s042482010018080x.

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An image contrast given in the scanning electron microscope(SEM) is due to differences in a detected number of secondary electrons (SE) coming from the specimen surface. The difference arises from the topographic, compositional and voltage features at the specimen surface. Two kinds of approaches have been taken for the quantification of SE images. One is to simulate electron trajectories in vacuum toward the detector, assuming the typical angular and energy distributions of electrons emitted from the specimen surface. However, the typical angular and energy distributions are not always applicable if a topographic or a compositional feature is present at the surface. The other is to simulate electron trajectory in the specimen. It is possible to obtain angular, energy, and spatial distributions of electrons emitted from the specimen surface. However, in order to discuss the SEM contrast based on these data, one has to assume that, for example, all slow electrons (<50eV) may be collected by the SE detector, or fast electrons ((>50eV) electrons may take a straight trajectory in the vacuum specimen chamber of the SEM. In a practical SEM picture of, for example, an etch-pit, different crystallographic plane surface shows different contrast even if the angle of the primary electron incidence toward all those surfaces is the same. This is because of the acceptance of the signal detection system. In a present study we combined two electron trajectory simulations mentioned above and calculated electron trajectories both in and out of the specimen, to simulate the trajectory from the point of the signal generated until the signal is detected.Although several simulation models of electron scatterings in a specimen have been reported to estimate the SE intensity at the surface, the model should be available to trace low energy (<50eV) electron trajectories. The model used here is basically the same as that reported in previous papers, and only a brief explanation is given in the following. Here, we made several assumptions as; [l]the energy loss of the primary and excited fast electrons is proportion to the number of SEs generated in the specimen, [2]the generated SE has an energy distribution as described by the Streitwolf equation, [3]the energy of the generated SEs are transferred to free electrons of the atom by the elastic-binary-collision, then one SE excited by the primary electron produces a ternary electron after the collision, and each one of the SE and the ternary electron produces higher order electrons in a cascade fashion. The simulation continues until the energy of each electron is less than the surface potential barrier. Angular and energy distributions and number of electrons emitted at the surface agree quite well with each experimental result in a typical case.

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32

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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33

Pan, M., K. Ishizuka, C. E. Meyer, O. L. Krivanek, J. Sasakit e Y. Kimurat. "Progress in Computer Assisted Electron Microscopy". Microscopy and Microanalysis 3, S2 (agosto 1997): 1093–94. http://dx.doi.org/10.1017/s1431927600012356.

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All the lenses, deflectors and stigmators of contemporary electron microscopes are controlled digitally by an internal computer. Control through RS232 serial interface by an external computer has also become a standard feature. This external control has made so-called computer assisted electron microscopy (CAEM) possible and practical. We are developing a CAEM system with two objectives: (1) to free inexperienced microscopists from technical details of operating an electron microscope, especially transmission electron microscopes (TEM); (2) to assist experienced microscopists to operate their microscopes with higher accuracy and efficiency. The features include automated and/or assisted standard operations in focusing, stigmating, and aligning the microscope, and also sophisticated tuning that requires the evaluation of subtle changes in image features such as aligning the incident electron beam direction in the presence of 3-fold astigmatism in objective lens. CAEM can further assist operators in selecting areas or objects and taking images/diffraction/energy spectrum with all the parameters well controlled and catalogued together, thus not only enabling ease-of-use and high accuracy in operation but also yielding more information on the specimen.

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Geiger, Dorin, Hannes Lichte, Martin Linck e Michael Lehmann. "Electron Holography with aCs-Corrected Transmission Electron Microscope". Microscopy and Microanalysis 14, n. 1 (21 dicembre 2007): 68–81. http://dx.doi.org/10.1017/s143192760808001x.

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Cscorrectors have revolutionized transmission electron microscopy (TEM) in that they substantially improve point resolution and information limit. The object information is found sharply localized within 0.1 nm, and the intensity image can therefore be interpreted reliably on an atomic scale. However, for a conventional intensity image, the object exit wave can still not be detected completely in that the phase, and hence indispensable object information is missing. Therefore, for example, atomic electric-field distributions or magnetic domain structures cannot be accessed. Off-axis electron holography offers unique possibilities to recover completely the aberration-corrected object wave with uncorrected microscopes and hence we would not need aCs-corrected microscope for improved lateral resolution. However, the performance of holography is affected by aberrations of the recording TEM in that the signal/noise properties (“phase detection limit”) of the reconstructed wave are degraded. Therefore, we have realized off-axis electron holography with aCs-corrected TEM. The phase detection limit improves by a factor of four. A further advantage is the possibility of fine-tuning the residual aberrations bya posterioricorrection. Therefore, a combination of both methods, that is,Cscorrection and off-axis electron holography, opens new perspectives for complete TEM analysis on an atomic scale.

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35

TONOMURA, Akira. "Holography Electron Microscope." Journal of the Japan Society for Precision Engineering 57, n. 7 (1991): 1165–68. http://dx.doi.org/10.2493/jjspe.57.1165.

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36

Shindo, Daisuke. "Transmission Electron Microscope". Materia Japan 44, n. 11 (2005): 932–35. http://dx.doi.org/10.2320/materia.44.932.

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37

MIYAKI, Atsushi. "Scanning Electron Microscope". Journal of the Japan Society of Colour Material 86, n. 4 (2013): 139–44. http://dx.doi.org/10.4011/shikizai.86.139.

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38

WATANABE, Shunya. "Scanning Electron Microscope". Journal of the Japan Society of Colour Material 79, n. 3 (2006): 120–25. http://dx.doi.org/10.4011/shikizai1937.79.120.

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39

TONOMURA, Akira. "Holography Electron Microscope". Journal of the Society of Mechanical Engineers 106, n. 1017 (2003): 661–64. http://dx.doi.org/10.1299/jsmemag.106.1017_661.

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40

Shoukry, Youssef. "Scanning electron microscope". Egyptian Journal of Histology 34, n. 2 (giugno 2011): 179–81. http://dx.doi.org/10.1097/01.ehx.0000398103.69273.b3.

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41

Skoglund, Ulf, e Bertil Daneholt. "Electron microscope tomography". Trends in Biochemical Sciences 11, n. 12 (dicembre 1986): 499–503. http://dx.doi.org/10.1016/0968-0004(86)90077-0.

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42

Kuokkala, V. T., e T. K. Lepistö. "TEMTUTOR - a Teaching Multimedia Program for TEM". Microscopy and Microanalysis 3, S2 (agosto 1997): 1161–62. http://dx.doi.org/10.1017/s1431927600012691.

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Abstract (sommario):

Teaching of transmission electron microscopy usually includes both lectures on the contrast theories, electron diffraction, etc., and practical hands-on operation of the microscope. The number of students attending the lectures is normally unlimited, but at the microscope, only a few persons can work at the same time. Since the microscopes are expensive, it would be of a great help if cheaper 'training' microscopes with basic imaging and diffraction capabilities were available. These functions, in fact, can quite easily be realized with fast personal computers and work stations, where the simulation of transmission electron micrographs and related diffraction patterns can help the student better understand the image formation processes. Adding text, audio and video help capabilities to the program, it can be made an efficient supplemental teaching tool.TemTutor for Windows is based on microScope for Windows, which is a BF/DF TEM micrograph simulation program for dislocations and stacking faults.

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43

Gauvin, Raynald, e Paula Horny. "The Characterization of Nano Materials in the FE-SEM". Microscopy and Microanalysis 6, S2 (agosto 2000): 744–45. http://dx.doi.org/10.1017/s1431927600036217.

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The observation of nano materials or nano phases is generally performed using Transmission Electron Microscopy (TEM) because conventional Scanning Electron Microscopes (SEM) do not have the resolution to image such small phases. Since the last decade, a new generation of microscopes is available on the market. These are the Field Emission Scanning Electron Microscope (FE-SEM) with a virtual secondary electron detector. The FE-SEM have a higher brightness allowing probe diameter smaller than 2.5 nm with incident electron energy, E0, below 5 keV. Furthermore, what gives FE-SEM outstanding resolution is the virtual secondary electron (SE) detector. The virtual SE detector is located above the objective lens and it is also named a through-the-lens (TTL) detector. Therefore, the SE images are mostly made up of all SE of type I and II, because those of type III, which are generated by the backscattered electrons in the chamber, are not collected.

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44

Schwarzer, Robert. "Orientation Microscopy Using the Analytical Scanning Electron Microscope". Practical Metallography 51, n. 3 (17 marzo 2014): 160–79. http://dx.doi.org/10.3139/147.110280.

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45

Hetherington, Craig L., Connor G. Bischak, Claire E. Stachelrodt, Jake T. Precht, Zhe Wang, Darrell G. Schlom e Naomi S. Ginsberg. "Superresolution Fluorescence Microscopy within a Scanning Electron Microscope". Biophysical Journal 108, n. 2 (gennaio 2015): 190a—191a. http://dx.doi.org/10.1016/j.bpj.2014.11.1054.

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46

Dingley, David J. "Orientation Imaging Microscopy for the Transmission Electron Microscope". Microchimica Acta 155, n. 1-2 (6 giugno 2006): 19–29. http://dx.doi.org/10.1007/s00604-006-0502-4.

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47

Battistella, Florent, Steven Berger e Andrew Mackintosh. "Scanning Optical Microscopy via a Scanning Electron Microscope". Journal of Electron Microscopy Technique 6, n. 4 (agosto 1987): 377–84. http://dx.doi.org/10.1002/jemt.1060060408.

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48

Martone, Maryann E. "Bridging the Resolution Gap: Correlated 3D Light and Electron Microscopic Analysis of Large Biological Structures". Microscopy and Microanalysis 5, S2 (agosto 1999): 526–27. http://dx.doi.org/10.1017/s1431927600015956.

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Abstract (sommario):

One class of biological structures that has always presented special difficulties to scientists interested in quantitative analysis is comprised of extended structures that possess fine structural features. Examples of these structures include neuronal spiny dendrites and organelles such as the Golgi apparatus and endoplasmic reticulum. Such structures may extend 10's or even 100's of microns, a size range best visualized with the light microscope, yet possess fine structural detail on the order of nanometers that require the electron microscope to resolve. Quantitative information, such as surface area, volume and the micro-distribution of cellular constituents, is often required for the development of accurate structural models of cells and organelle systems and for assessing and characterizing changes due to experimental manipulation. Performing estimates of such quantities from light microscopic data can result in gross inaccuracies because the contribution to total morphometries of delicate features such as membrane undulations and excrescences can be quite significant. For example, in a recent study by Shoop et al, electron microscopic analysis of cultured chick ciliary ganglion neurons showed that spiny projections from the plasmalemma that were not well resolved in the light microscope effectively doubled the surface area of these neurons.While the resolution provided by the electron microscope has yet to be matched or replaced by light microscopic methods, one drawback of electron microscopic analysis has always been the relatively small sample size and limited 3D information that can be obtained from samples prepared for conventional transmission electron microscopy. Reconstruction from serial electron micrographs has provided one way to circumvent this latter problem, but remains one of the most technically demanding skills in electron microscopy. Another approach to 3D electron microscopic imaging is high voltage electron microscopy (HVEM). The greater accelerating voltages of HVEM's allows for the use of much thicker specimens than conventional transmission electron microscopes.

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49

Hansen, Douglas. "The Scanning Electron Microscope As A Precision Instrument". Microscopy Today 4, n. 6 (agosto 1996): 30–34. http://dx.doi.org/10.1017/s1551929500060909.

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I began using scanning electron microscopes to solve problems encountered in the fabrication of x-ray diffraction gratings. Since these diffraction gratings consist of very regular lines and spaces, and produce high contrast images from the SEM. my microscopy work often points out problems with the microscope.One time, for example, I went to the university SEM lab I often use, and was advised that the microscope was down that day due to major field problems. This lab often had problems with stray fields for reasons no one could explain. Usually I was the only one to complain about stray field distortions since they are most obvious when imaging straight lines at high magnification, but on this occasion, the problem was serious and obvious to all.The microscope had just been serviced and as the lens coils had been replaced, they were expected to be the cause. The service technician was called in and determined that neither the coils nor the microscope electronics were the problem.

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McKeman, Stuart. "Ceramics in the environmental Scanning Electron Microscope". Proceedings, annual meeting, Electron Microscopy Society of America 51 (1 agosto 1993): 910–11. http://dx.doi.org/10.1017/s0424820100150381.

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Abstract (sommario):

Several recent advances have had a major potential impact on the microscopy of ceramic materials. The ability of modern scanning electron microscopes to image uncoated materials, at low voltage for example, whilst still maintaining high resolution should make possible a wide variety of experiments that were hitherto impossible to contemplate. This ability to look at the unmodified surface of a ceramic enables iterative or dynamic experiments to be done with a lot more confidence in the results than has been possible before. A second advance has been the introduction of microscopes capable of operating at higher pressures than was previously possible. This makes possible the ability to image specimens in a variety of different environments. The environmental scanning electron microscope (ESEM) exploits of both of these novel areas. The aim of this review is to highlight areas where the unique capabilities of the ESEM may be applied to advance our understanding of ceramics.

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