WorldWideScience

Sample records for tem microscopy

  1. The principle of electron microscopy; SEM and TEM

    International Nuclear Information System (INIS)

    Fauzi, S.H.

    1992-01-01

    The article reviews the principle of electron microscopy which is used in scanning electron microscope (SEM) and transmission electron microscope (TEM). These instruments are important for the examination and analysis of the microstructural properties of solid objects. Relevance physical concept lies behind the devices are given. The main components of each device are also discussed

  2. An efficient and reproducible process for transmission electron microscopy (TEM) of rare cell populations

    Science.gov (United States)

    Kumar, Sachin; Ciraolo, Georgianne; Hinge, Ashwini; Filippi, Marie-Dominique

    2014-01-01

    Transmission electron microscopy (TEM) provides ultra-structural details of cells at the sub-organelle level. However, details of the cellular ultrastructure, and the cellular organization and content of various organelles in rare populations, particularly in the suspension, like hematopoietic stem cells (HSCs) remained elusive. This is mainly due to the requirement of millions of cells for TEM studies. Thus, there is a vital requirement of a method that will allow TEM studies with low cell numbers of such rare populations. We describe an alternative and novel approach for TEM studies for rare cell populations. Here we performed TEM study from 10,000 HSC cells with quite ease. In particular, tiny cell pellets were identified by Evans blue staining after PFA-GA fixation. The cell pellet was pre-embedded in agarose in a small microcentrifuge tube and processed for dehydration, infiltration and embedding. Semi-thin and ultra-thin sections identified clusters of numerous cells per sections with well preserved morphology and ultrastructural details of golgi complex and mitochondria. Together, this method provides an efficient, easy and reproducible process to perform qualitative and quantitative TEM analysis from limited biological samples including cells in suspension. PMID:24291346

  3. Atom-counting in High Resolution Electron Microscopy:TEM or STEM - That's the question.

    Science.gov (United States)

    Gonnissen, J; De Backer, A; den Dekker, A J; Sijbers, J; Van Aert, S

    2017-03-01

    In this work, a recently developed quantitative approach based on the principles of detection theory is used in order to determine the possibilities and limitations of High Resolution Scanning Transmission Electron Microscopy (HR STEM) and HR TEM for atom-counting. So far, HR STEM has been shown to be an appropriate imaging mode to count the number of atoms in a projected atomic column. Recently, it has been demonstrated that HR TEM, when using negative spherical aberration imaging, is suitable for atom-counting as well. The capabilities of both imaging techniques are investigated and compared using the probability of error as a criterion. It is shown that for the same incoming electron dose, HR STEM outperforms HR TEM under common practice standards, i.e. when the decision is based on the probability function of the peak intensities in HR TEM and of the scattering cross-sections in HR STEM. If the atom-counting decision is based on the joint probability function of the image pixel values, the dependence of all image pixel intensities as a function of thickness should be known accurately. Under this assumption, the probability of error may decrease significantly for atom-counting in HR TEM and may, in theory, become lower as compared to HR STEM under the predicted optimal experimental settings. However, the commonly used standard for atom-counting in HR STEM leads to a high performance and has been shown to work in practice. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. eV-TEM: Transmission electron microscopy in a low energy cathode lens instrument

    Energy Technology Data Exchange (ETDEWEB)

    Geelen, Daniël, E-mail: geelen@physics.leidenuniv.nl [Huygens-Kamerlingh Onnes Laboratory, Leiden Institute of Physics, Leiden University, P.O. Box 9504, 2300 RA Leiden (Netherlands); Thete, Aniket [Huygens-Kamerlingh Onnes Laboratory, Leiden Institute of Physics, Leiden University, P.O. Box 9504, 2300 RA Leiden (Netherlands); Schaff, Oliver; Kaiser, Alexander [SPECS GmbH, Voltastrasse 5, D-13355 Berlin (Germany); Molen, Sense Jan van der [Huygens-Kamerlingh Onnes Laboratory, Leiden Institute of Physics, Leiden University, P.O. Box 9504, 2300 RA Leiden (Netherlands); Tromp, Rudolf [IBM T.J. Watson Research Center, 1101 Kitchawan Road, P.O. Box 218, Yorktown Heights, NY 10598 (United States)

    2015-12-15

    We are developing a transmission electron microscope that operates at extremely low electron energies, 0–40 eV. We call this technique eV-TEM. Its feasibility is based on the fact that at very low electron energies the number of energy loss pathways decreases. Hence, the electron inelastic mean free path increases dramatically. eV-TEM will enable us to study elastic and inelastic interactions of electrons with thin samples. With the recent development of aberration correction in cathode lens instruments, a spatial resolution of a few nm appears within range, even for these very low electron energies. Such resolution will be highly relevant to study biological samples such as proteins and cell membranes. The low electron energies minimize adverse effects due to radiation damage. - Highlights: • We present a new way of performing low energy transmission electron microscopy in an aberration corrected LEEM/PEEM instrument. • We show a proof of principle where we measure transmitted electrons through a suspended graphene monolayer with a preliminary setup. • We present an improved setup design that provides better control of the incident electron beam.

  5. Analysis of Premature Wear-Out of Aircraft Gun Barrel by Applying a Transmission Electron Microscopy (TEM

    Directory of Open Access Journals (Sweden)

    Łęczycki Krzysztof

    2017-08-01

    Full Text Available Firing from gun armament generates a wide range of physico-chemical phenomena contributing to the degradation of barrel material, e.g. pressure, high temperature, chemically aggressive character of post-detonation gases and friction of a driving band. In this work the technique of thin foils was used in Transmission Electron Microscopy (TEM to study the influence of physicochemical phenomena on the material microstructure of aircraft gun barrel. A mechanism and reason of premature wear-out of the barrel under consideration was also outlined by utilising light microscopy and hardness measurements.

  6. Towards 3D crystal orientation reconstruction using automated crystal orientation mapping transmission electron microscopy (ACOM-TEM).

    Science.gov (United States)

    Kobler, Aaron; Kübel, Christian

    2018-01-01

    To relate the internal structure of a volume (crystallite and phase boundaries) to properties (electrical, magnetic, mechanical, thermal), a full 3D reconstruction in combination with in situ testing is desirable. In situ testing allows the crystallographic changes in a material to be followed by tracking and comparing the individual crystals and phases. Standard transmission electron microscopy (TEM) delivers a projection image through the 3D volume of an electron-transparent TEM sample lamella. Only with the help of a dedicated TEM tomography sample holder is an accurate 3D reconstruction of the TEM lamella currently possible. 2D crystal orientation mapping has become a standard method for crystal orientation and phase determination while 3D crystal orientation mapping have been reported only a few times. The combination of in situ testing with 3D crystal orientation mapping remains a challenge in terms of stability and accuracy. Here, we outline a method to 3D reconstruct the crystal orientation from a superimposed diffraction pattern of overlapping crystals without sample tilt. Avoiding the typically required tilt series for 3D reconstruction enables not only faster in situ tests but also opens the possibility for more stable and more accurate in situ mechanical testing. The approach laid out here should serve as an inspiration for further research and does not make a claim to be complete.

  7. Transmission Electron Microscopy (TEM) Sample Preparation of Si(1-x)Gex in c-Plane Sapphire Substrate

    Science.gov (United States)

    Kim, Hyun Jung; Choi, Sang H.; Bae, Hyung-Bin; Lee, Tae Woo

    2012-01-01

    The National Aeronautics and Space Administration-invented X-ray diffraction (XRD) methods, including the total defect density measurement method and the spatial wafer mapping method, have confirmed super hetero epitaxy growth for rhombohedral single crystalline silicon germanium (Si1-xGex) on a c-plane sapphire substrate. However, the XRD method cannot observe the surface morphology or roughness because of the method s limited resolution. Therefore the authors used transmission electron microscopy (TEM) with samples prepared in two ways, the focused ion beam (FIB) method and the tripod method to study the structure between Si1-xGex and sapphire substrate and Si1?xGex itself. The sample preparation for TEM should be as fast as possible so that the sample should contain few or no artifacts induced by the preparation. The standard sample preparation method of mechanical polishing often requires a relatively long ion milling time (several hours), which increases the probability of inducing defects into the sample. The TEM sampling of the Si1-xGex on sapphire is also difficult because of the sapphire s high hardness and mechanical instability. The FIB method and the tripod method eliminate both problems when performing a cross-section TEM sampling of Si1-xGex on c-plane sapphire, which shows the surface morphology, the interface between film and substrate, and the crystal structure of the film. This paper explains the FIB sampling method and the tripod sampling method, and why sampling Si1-xGex, on a sapphire substrate with TEM, is necessary.

  8. Atomic-resolution environmental TEM for quantitative in-situ microscopy in materials science.

    Science.gov (United States)

    Takeda, Seiji; Yoshida, Hideto

    2013-02-01

    We have compiled our recent in-situ quantitative environmental transmission electron microscopy (ETEM) studies on typical gold nanoparticulate catalysts for the low-temperature oxidation of CO to describe the issues surrounding the application of ETEM, with a special regard to catalyst chemistry. Thanks to the recent development of high-resolution environmental transmission electron microscopes that can work robustly to accumulate observation data in controlled environments, we can deal with the electron irradiation effects and heterogeneity of real catalysts. We established a structural evolution diagram that summarizes the structure of catalysts under electron irradiation as a function of the electron current density ϕ and the electron dose, D. By extrapolating to ϕ = 0, D = 0, we could deduce the intrinsic catalysis structure (without electron irradiation) in various environments, including reaction environments. By numerically and statistically analyzing a substantial number of ETEM images of gold nanoparticles, we established a morphology phase diagram that summarizes how the majority of gold nanoparticles change their morphology systematically as a function of the partial pressures of CO and O(2). Similar diagrams will be helpful in elucidating the phenomena that directly correlate with the catalytic activity determined from ETEM observations. Using these quantitative analyses, we could analyze Cs-corrected ETEM images of the catalysts. The surfaces of gold nanoparticles were structurally reconstructed under reaction conditions, via interactions with CO molecules. CO molecules were observed on the surfaces of catalysts under reaction conditions using high-resolution ETEM. Finally, we discuss the potential of environmental transmission electron microscopy for quantitative in-situ microscopy at the atomic scale.

  9. High-resolution TEM microscopy study of the creep behaviour of carbon-based cathode materials

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Wei, E-mail: wwlyzwkj@126.com [College of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471023 (China); Collaborative Innovation Center of Nonferrous Metals Henan Province, Luoyang 471023 (China); Chen, Weijie [College of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471023 (China); Collaborative Innovation Center of Nonferrous Metals Henan Province, Luoyang 471023 (China); Gu, Wanduo [Collaborative Innovation Center of Nonferrous Metals Henan Province, Luoyang 471023 (China)

    2017-02-27

    Creep is in close relationship with the materials deterioration and deformation of the cathodes in aluminum reduction cells. The purpose of this work is to obtain the creep mechanism of the carbon cathode for aluminum electrolysis. A modified Rapoport equipment was used for measuring the creep strain of the semi-graphitic cathodes during aluminum electrolysis with CR=2.5 and at temperature of 945 ℃. The arrangement of carbon atom has been studied after hexagonal graphite converting into rhombohedral graphite during aluminum electrolysis by XRD and high-resolution transmission electron microscopy (HRTEM). The creep deformation of the carbon cathode has a close relationship with the mobile dislocation walls. These results will be helpful in controlling the cathode quality and its performance in aluminum reduction cells.

  10. Visualising reacting single atoms under controlled conditions: Advances in atomic resolution in situ Environmental (Scanning) Transmission Electron Microscopy (E(S)TEM)

    Science.gov (United States)

    Boyes, Edward D.; Gai, Pratibha L.

    2014-02-01

    Advances in atomic resolution Environmental (Scanning) Transmission Electron Microscopy (E(S)TEM) for probing gas-solid catalyst reactions in situ at the atomic level under controlled reaction conditions of gas environment and temperature are described. The recent development of the ESTEM extends the capability of the ETEM by providing the direct visualisation of single atoms and the atomic structure of selected solid state heterogeneous catalysts in their working states in real-time. Atomic resolution E(S)TEM provides a deeper understanding of the dynamic atomic processes at the surface of solids and their mechanisms of operation. The benefits of atomic resolution-E(S)TEM to science and technology include new knowledge leading to improved technological processes with substantial economic benefits, improved healthcare, reductions in energy needs and the management of environmental waste generation. xml:lang="fr"

  11. Characterization of duplex stainless steels by TEM [transmission electron microscopy], SANS [small-angle neutron scattering], and APFIM [atom-probe field ion microscopy] techniques

    International Nuclear Information System (INIS)

    Chung, H.M.; Chopra, O.K.

    1987-06-01

    Results are presented of complementary characterization of aged duplex stainless steels by advanced metallographic techniques, including transmission and high-voltage electron microscopies; small-angle neutron scattering; and atom-probe field ion microscopy. On the basis of the characterization, the mechanisms of aging embrittlement have been shown to be associated with the precipitation of Ni- and Si-rich G phase and Cr-rich α' in the ferrite, and M 23 C 6 carbides on the austenite-ferrite phase boundaries. 19 refs., 19 figs., 1 tab

  12. First ultrastructural data on the human tapeworm Taenia asiatica eggs by scanning and transmission electron microscopy (SEM, TEM).

    Science.gov (United States)

    Galán-Puchades, M Teresa; Yang, Yichao; Marcilla, Antonio; Choe, Seongjun; Park, Hansol; Osuna, Antonio; Eom, Keeseon S

    2016-09-01

    Humans are definitive hosts of three species of the Taenia genus, namely Taenia solium, Taenia saginata and Taenia asiatica. The relative novelty of the latter explains the lack of knowledge concerning certain relevant aspects related to this parasite, such as its definite geographical distribution and whether its eggs can infect humans or not. So far, only the eggs of T. solium are known to be infective for humans, producing cysticercosis. Although eggs contain the infective stage, the oncosphere, there is a lack of research on the ultrastructure of eggs of human taeniids. We show, for the first time, the ultrastructure of eggs of T. asiatica by means of SEM and TEM analyses. We detected all the envelopes, namely the egg shell, vitelline layer, outer embryophoric membrane, embryophore, granular layer, basal membrane, oncospheral membrane and oncospheral tegument. Hooks surrounded by myofibrils and glycogen-like particles, the two types of secretory granules of the penetration glands, as well as several nuclei and mitochondria were also revealed in the oncospheres. In addition to the already known structures in eggs from other Taenia species, the presence of two types of small vesicles is described herein, possibly corresponding to exosomes and ectosomes because of their shape and size, which could participate in the host/parasite intercellular communication.

  13. Is the TEM obsolescent?

    International Nuclear Information System (INIS)

    Williams, D.B.

    2002-01-01

    significantly faster and has become more indispensable than the TEM to the future of materials research in many areas. For instance, the ability of modern SEMs to characterize the crystallographic make-up of complex materials via electron backscatter pattern diffraction analysis should have been available via kikuchi pattern and CBED analysis on a computerized TEM many years ago. In the author's opinion, unless significant moves are made to redesign the TEM to become significantly more flexible, more easily operated and much cheaper, other instruments will take over the TEM market and there will be no need for mammoth tomes of several hundred pages instructing students on the intricacies of operation of this once-proud instrument. Copyright (2002) Australian Society for Electron Microscopy Inc

  14. Microscopy

    Science.gov (United States)

    Patricia A. Moss; Les Groom

    2001-01-01

    Microscopy is the study and interpretation of images produced by a microscope. "Interpretation" is the keyword, because the microscope enables one to see structures that are too small or too close together to be resolved by the unaided eye. (The human eye cannot separate two points or lines that are closer together than 0.1 mm.) it is important to...

  15. In Situ High-Resolution Transmission Electron Microscopy (TEM) Observation of Sn Nanoparticles on SnO2 Nanotubes Under Lithiation.

    Science.gov (United States)

    Cheong, Jun Young; Chang, Joon Ha; Kim, Sung Joo; Kim, Chanhoon; Seo, Hyeon Kook; Shin, Jae Won; Yuk, Jong Min; Lee, Jeong Yong; Kim, Il-Doo

    2017-12-01

    We trace Sn nanoparticles (NPs) produced from SnO2 nanotubes (NTs) during lithiation initialized by high energy e-beam irradiation. The growth dynamics of Sn NPs is visualized in liquid electrolytes by graphene liquid cell transmission electron microscopy. The observation reveals that Sn NPs grow on the surface of SnO2 NTs via coalescence and the final shape of agglomerated NPs is governed by surface energy of the Sn NPs and the interfacial energy between Sn NPs and SnO2 NTs. Our result will likely benefit more rational material design of the ideal interface for facile ion insertion.

  16. Networking strategies of the microscopy community for improved utilization of advanced instruments: (3) Two European initiatives to support TEM infrastructures and promote electron microscopy over Europe, ESTEEM (2006-2011) and ESTEEM 2 (2012-2016)

    International Nuclear Information System (INIS)

    Snoeck, E.; Van Tendeloo, G.

    2014-01-01

    The ESTEEM consortium of electron microscopy laboratories for materials science and solid-state physics has been created as an EU-supported delocalized infrastructure to bring together the major electron microscopy centres in Europe. Its main objectives were to develop networking, to offer trans-national access to these centres with specialized and complementary techniques and skills and to upgrade in close collaboration different technical and methodological aspects such as tomography, spectroscopy, holography, detectors, and specimen holders. These efforts were aimed to strengthen the position of European microscopy and to generate new technologies potentially of high relevance in many domains identified as strategic. Following the success of the first program, ESTEEM has been conducted again in 2012 for 4 more years with an enlarged set of partners. (authors)

  17. Electron microscopy for Engineers

    International Nuclear Information System (INIS)

    Jones, I P

    2009-01-01

    This paper reviews the application of (mainly) Transmission Electron Microscopy (TEM) in an engineering context. The first two sections are TEM and chemical in nature; the final three sections are more general and include aspects of Scanning Electron Microscopy (SEM).

  18. Recent advances in FIB-TEM specimen preparation techniques

    International Nuclear Information System (INIS)

    Li Jian; Malis, T.; Dionne, S.

    2006-01-01

    Preparing high-quality transmission electron microscopy (TEM) specimens is of paramount importance in TEM studies. The development of the focused ion beam (FIB) microscope has greatly enhanced TEM specimen preparation capabilities. In recent years, various FIB-TEM foil preparation techniques have been developed. However, the currently available techniques fail to produce TEM specimens from fragile and ultra-fine specimens such as fine fibers. In this paper, the conventional FIB-TEM specimen preparation techniques are reviewed, and their advantages and shortcomings are compared. In addition, a new technique suitable to prepare TEM samples from ultra-fine specimens is demonstrated

  19. In Situ TEM Creation of Nanowire Devices

    DEFF Research Database (Denmark)

    Alam, Sardar Bilal

    Integration of silicon nanowires (SiNWs) as active components in devices requires that desired mechanical, thermal and electrical interfaces can be established between the nanoscale geometry of the SiNW and the microscale architecture of the device. In situ transmission electron microscopy (TEM),...

  20. SAXS and TEM Investigation of Bentonite Structure

    International Nuclear Information System (INIS)

    Matusewicz, Michal; Liljestroem, Ville; Muurinen, Arto; Serimaa, Ritva

    2013-01-01

    A preliminary investigation of bentonite structure using Small-Angle X-ray Scattering (SAXS) and Transmission Electron Microscopy (TEM) is presented. Three types of clay were used: unchanged MX-80 bentonite and purified clays with sodium or calcium ions. Quantitative information in nano-scale - basal spacing, mean crystallite size - was obtained from SAXS, which was complemented by TEM to give qualitative information from micron to nanometre scale. SAXS seems to be a more reliable source of quantitative data than TEM. SAXS gives the averaged information about basal spacing. TEM in this study gives more qualitative information, but in a greater resolution range. The presented work is a starting point to combine more methods to obtain a better idea of bentonite structure. (authors)

  1. TEM of nanostructured metals and alloys

    International Nuclear Information System (INIS)

    Karnthaler, H.P.; Waitz, T.; Rentenberger, C.; Mingler, B.

    2004-01-01

    Nanostructuring has been used to improve the mechanical properties of bulk metals and alloys. Transmission electron microscopy (TEM) including atomic resolution is therefore appropriate to study these nanostructures; four examples are given as follows. (1) The early stages of precipitation at RT were investigated in an Al-Mg-Si alloy. By high resolution TEM it is shown that the precipitates lie on (0 0 1) planes having an ordered structure. (2) In Co alloys the fronts of martensitic phase transformations were analysed showing that the transformation strains are very small thus causing no surface relief. (3) Re-ordering and recrystallization were studied by in situ TEM of an Ni 3 Al alloy being nanocrystalline after severe plastic deformation. (4) In NiTi severe plastic deformation is leading to the formation of amorphous shear bands. From the TEM analysis it is concluded that the amorphization is caused by plastic shear instability starting in the shear bands

  2. Moessbauer effect and TEM in mineralogy

    International Nuclear Information System (INIS)

    Ferrow, E.A.

    1994-01-01

    Moessbauer effect (ME) provides useful information on oxidation state, co-ordination number, co-ordination state, site occupancies, and magnetic properties of Fe-bearing phases. The information gained by ME together with the information provided by other conventional techniques is used to extract temperature, pressure, and kinetics of rock-forming processes. Nevertheless, ME requires that the phases studied are homogeneous over an extremely large volume and that Fe is a major component of the system. Transmission electron microscopy (TEM), on the other hand, provides similar information over a very small volume for a system of any component. However, present TEM spectrometers do not provide sufficient resolution to detect the mixed oxidation state. A complete characterisation of phases in rocks requires, therefore, that conventional techniques be combined with TEM. (orig.)

  3. In-situ TEM Studies : Heat-treatment and Corrosion

    NARCIS (Netherlands)

    Malladi, S.R.K.

    2014-01-01

    Transmission electron microscopy (TEM) has been well known as a powerful characterisation tool to understand the structure and composition of various materials down to the atomic level. Over the years, several TEM studies have been carried out to understand the compositional, structural and

  4. Stereoscopic methods in TEM

    International Nuclear Information System (INIS)

    Thomas, L.E.

    1975-07-01

    Stereoscopic methods used in TEM are reviewed. The use of stereoscopy to characterize three-dimensional structures observed by TEM has become widespread since the introduction of instruments operating at 1 MV. In its emphasis on whole structures and thick specimens this approach differs significantly from conventional methods of microstructural analysis based on three-dimensional image reconstruction from a number of thin-section views. The great advantage of stereo derives from the ability to directly perceive and measure structures in three-dimensions by capitalizing on the unsurpassed human ability for stereoscopic matching of corresponding details on picture pairs showing the same features from different viewpoints. At this time, stereo methods are aimed mainly at structural understanding at the level of dislocations, precipitates, and irradiation-induced point-defect clusters in crystal and on the cellular irradiation-induced point-defect clusters in crystal and on the cellular level of biological specimens. 3-d reconstruction methods have concentrated on the molecular level where image resolution requirements dictate the use of very thin specimens. One recent application of three-dimensional coordinate measurements is a system developed for analyzing depth variations in the numbers, sizes and total volumes of voids produced near the surfaces of metal specimens during energetic ion bombardment. This system was used to correlate the void volumes at each depth along the ion range with the number of atomic displacements produced at that depth, thereby unfolding the entire swelling versus dose relationship from a single stereo view. A later version of this system incorporating computer-controlled stereo display capabilities is now being built

  5. 40 keV atomic resolution TEM

    International Nuclear Information System (INIS)

    Bell, David C.; Russo, Christopher J.; Kolmykov, Dmitry V.

    2012-01-01

    Here we present the first atomic resolution TEM imaging at 40 keV using an aberration-corrected, monochromated source TEM. Low-voltage High-Resolution Electron Microscopy (LVHREM) has several advantages, including increased cross-sections for inelastic and elastic scattering, increased contrast per electron and improved spectroscopy efficiency, decreased delocalization effects and reduced knock-on damage. Together, these often improve the contrast to damage ratio obtained on a large class of samples. Third-order aberration correction now allows us to operate the TEM at low energies while retaining atomic resolution, which was previously impossible. At low voltage the major limitation to resolution becomes the chromatic aberration limit. We show that using a source monochromator we are able to reduce the effect of chromatic aberration and achieve a usable high-resolution limit at 40 keV to less than 1 Å. We show various materials' examples of the application of the technique to image graphene and silicon, and compare atomic resolution images with electron multislice simulations. -- Highlights: ► We present the first atomic resolution images recorded at 40 keV using an aberration-corrected, monochromated TEM. ► We show information transfer measured to better than 1 Å. ► At 40 keV an aberration-corrected monochromated TEM is limited by fifth-order spherical aberration. ► We show that using a monochromator the effect of chromatic aberration is reduced to enable high resolution imaging. ► Low voltage high resolution electron microscopy will be beneficial for imaging the organic/inorganic materials interface.

  6. In Situ TEM Electrical Measurements

    DEFF Research Database (Denmark)

    Canepa, Silvia; Alam, Sardar Bilal; Ngo, Duc-The

    2016-01-01

    understanding of complex physical and chemical interactions in the pursuit to optimize nanostructure function and device performance. Recent developments of sample holder technology for TEM have enabled a new field of research in the study of functional nanomaterials and devices via electrical stimulation...... influence the sample by external stimuli, e.g. through electrical connections, the TEM becomes a powerful laboratory for performing quantitative real time in situ experiments. Such TEM setups enable the characterization of nanostructures and nanodevices under working conditions, thereby providing a deeper...... and measurement of the specimen. Recognizing the benefits of electrical measurements for in situ TEM, many research groups have focused their effort in this field and some of these methods have transferred to ETEM. This chapter will describe recent advances in the in situ TEM investigation of nanostructured...

  7. Electron microscopy in metallurgy

    International Nuclear Information System (INIS)

    Loretto, M.H.

    1980-01-01

    The aim of this paper is to review briefly the contribution which (TEM) transmission electron microscopy (including high voltage electron microscopy (HVEM)) has made to metallurgy. Since it is straightforward with modern electron microscopes to extract the crystallographic information which provides the basis for any interpretation, the major problem in most metallurgical work lies in assessing how the structure (which TEM has characterised) has arisen and which properties of the specimen can be understood in terms of this structure. Radiation damage, quenching, phase transformations, grain boundaries and plastic deformation have been the main fields in which TEM has contributed significantly. After briefly summarising the role of TEM in each field, examples of recent work will be used to indicate current TEM activity in physical metallurgy. (author)

  8. TEM sample preparation by FIB for carbon nanotube interconnects

    International Nuclear Information System (INIS)

    Ke, Xiaoxing; Bals, Sara; Romo Negreira, Ainhoa; Hantschel, Thomas; Bender, Hugo; Van Tendeloo, Gustaaf

    2009-01-01

    A powerful method to study carbon nanotubes (CNTs) grown in patterned substrates for potential interconnects applications is transmission electron microscopy (TEM). However, high-quality TEM samples are necessary for such a study. Here, TEM specimen preparation by focused ion beam (FIB) has been used to obtain lamellae of patterned samples containing CNTs grown inside contact holes. A dual-cap Pt protection layer and an extensive 5 kV cleaning procedure are applied in order to preserve the CNTs and avoid deterioration during milling. TEM results show that the inner shell structure of the carbon nanotubes has been preserved, which proves that focused ion beam is a useful technique to prepare TEM samples of CNT interconnects.

  9. TEM sample preparation by FIB for carbon nanotube interconnects

    Energy Technology Data Exchange (ETDEWEB)

    Ke, Xiaoxing, E-mail: xiaoxing.ke@ua.ac.be [EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Bals, Sara [EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Romo Negreira, Ainhoa [IMEC, Kapeldreef 75, B-3001 Leuven (Belgium); Metallurgy and Materials Engineering Department, KU Leuven, Kasteelpark Arenberg 44, Leuven B-3001 (Belgium); Hantschel, Thomas; Bender, Hugo [IMEC, Kapeldreef 75, B-3001 Leuven (Belgium); Van Tendeloo, Gustaaf [EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)

    2009-10-15

    A powerful method to study carbon nanotubes (CNTs) grown in patterned substrates for potential interconnects applications is transmission electron microscopy (TEM). However, high-quality TEM samples are necessary for such a study. Here, TEM specimen preparation by focused ion beam (FIB) has been used to obtain lamellae of patterned samples containing CNTs grown inside contact holes. A dual-cap Pt protection layer and an extensive 5 kV cleaning procedure are applied in order to preserve the CNTs and avoid deterioration during milling. TEM results show that the inner shell structure of the carbon nanotubes has been preserved, which proves that focused ion beam is a useful technique to prepare TEM samples of CNT interconnects.

  10. Environmental TEM for Materials Research

    DEFF Research Database (Denmark)

    Hansen, Thomas Willum

    Over the last decades, electron microscopy has played a large role in materials research. The increasing use of particularly environmental transmission electron microscopy (ETEM) in materials science provides new possibilities for investigating nanoscale components at work. Careful experimentation...

  11. Environmental TEM in Materials Research

    DEFF Research Database (Denmark)

    Hansen, Thomas Willum; Wagner, Jakob Birkedal

    Over the last decades, electron microscopy has played a large role in materials research. The increasing use of particularly environmental transmission electron microscopy (ETEM) in materials science provides new possibilities for investigating nanoscale components at work. Careful experimentation...

  12. TEM turbulence optimisation in stellarators

    Science.gov (United States)

    Proll, J. H. E.; Mynick, H. E.; Xanthopoulos, P.; Lazerson, S. A.; Faber, B. J.

    2016-01-01

    With the advent of neoclassically optimised stellarators, optimising stellarators for turbulent transport is an important next step. The reduction of ion-temperature-gradient-driven turbulence has been achieved via shaping of the magnetic field, and the reduction of trapped-electron mode (TEM) turbulence is addressed in the present paper. Recent analytical and numerical findings suggest TEMs are stabilised when a large fraction of trapped particles experiences favourable bounce-averaged curvature. This is the case for example in Wendelstein 7-X (Beidler et al 1990 Fusion Technol. 17 148) and other Helias-type stellarators. Using this knowledge, a proxy function was designed to estimate the TEM dynamics, allowing optimal configurations for TEM stability to be determined with the STELLOPT (Spong et al 2001 Nucl. Fusion 41 711) code without extensive turbulence simulations. A first proof-of-principle optimised equilibrium stemming from the TEM-dominated stellarator experiment HSX (Anderson et al 1995 Fusion Technol. 27 273) is presented for which a reduction of the linear growth rates is achieved over a broad range of the operational parameter space. As an important consequence of this property, the turbulent heat flux levels are reduced compared with the initial configuration.

  13. TEM studies of P+ implanted and subsequently laser annealed Si

    International Nuclear Information System (INIS)

    Sadana, D.K.; Wilson, M.C.; Booker, G.R.; Washburn, J.

    1979-05-01

    The present investigation is concerned with laser annealing of P + implanted Si. The aim of the work was to study the crystallization behavior of damage structure occurring due to high dose rate implantation using transmission electron microscopy (TEM) as the method of examination

  14. A simple algorithm for measuring particle size distributions on an uneven background from TEM images

    DEFF Research Database (Denmark)

    Gontard, Lionel Cervera; Ozkaya, Dogan; Dunin-Borkowski, Rafal E.

    2011-01-01

    Nanoparticles have a wide range of applications in science and technology. Their sizes are often measured using transmission electron microscopy (TEM) or X-ray diffraction. Here, we describe a simple computer algorithm for measuring particle size distributions from TEM images in the presence of a...... application to images of heterogeneous catalysts is presented.......Nanoparticles have a wide range of applications in science and technology. Their sizes are often measured using transmission electron microscopy (TEM) or X-ray diffraction. Here, we describe a simple computer algorithm for measuring particle size distributions from TEM images in the presence...

  15. In vitro safety assessment of papain on human skin: A qualitative Light and Transmission Electron Microscopy (TEM study Avaliação in vitro da segurança de uso da papaína em pele humana: Estudo qualitativo por microscopia de luz e eletrônica de transmissão (MET

    Directory of Open Access Journals (Sweden)

    Patrícia Santos Lopes

    2008-03-01

    Full Text Available Papain is a thiol proteolytic enzyme widely used in dermatology that found applications in wound treatment. Recently, papain was also used as absorption enhancer which can modify the peptide/protein material in the bilayer domain. We investigated papain safety using human skin that was exposed to papain in vitro at different times: 4, 24 and 48 hours. The samples were examined using Light and Transmission Electron Microscopy (TEM to study of the mechanisms involved in enhancer-skin interaction. After 24 hours, changes occurred in corneosomes. However, samples of 48 hours did not show major changes in agreement with the control. These findings indicated that papain could be used safely onto the skin.Papaína é uma enzima proteolítica amplamente utilizada na dermatologia para o tratamento de feridas. Atualmente, a papaína também tem sido empregada como promotor de absorção cutânea passível de modificar os domínios protéicos da epiderme. Nesta pesquisa investigou-se in vitro a segurança da papaína, utilizando pele humana exposta a enzima em diferentes períodos de tempo de contato: 4, 24 e 48 horas. As amostras foram avaliadas por Microscopia de Luz e Eletrônica de Transmissão (MET, técnicas que podem ser utilizadas no estudo dos mecanismos envolvidos na interação de promotores de absorção cutânea e a pele. Após 24 horas de contato entre a pele a solução de papaína, mudanças ocorreram nos corneossomos, no entanto, as amostras em contato por 24 horas não evidenciaram alterações relevantes comparadas com o controle. Os resultados indicaram que a papaína poderia ser seguramente aplicada sobre a pele.

  16. A TEM Study on the Ti-Alloyed Grey Iron

    DEFF Research Database (Denmark)

    Moumeni, Elham; Tiedje, Niels Skat; Grumsen, Flemming Bjerg

    2014-01-01

    The microstructure of graphite flakes in titanium alloyed cast iron is studied using electron microscopy techniques. Dual beam SEM/FIB has been used for TEM sample preparation. A TEM study has been carried out on graphite flakes in grey cast iron using selected area electron diffraction. Based...... and that there is a high proportion of twins in the fine grained graphite. It appears that twinning and stacking faults are involved in the fine grained structure of the graphite. It is discussed how Ti addition affect crystal growth and may lead to formation of superfine graphite....

  17. Illuminating Electron Microscopy of Photocatalysts

    DEFF Research Database (Denmark)

    Cavalca, Filippo

    .1% of the surface of the planet with a device that converts solar energy into a useable form at 10% efficiency would give more than the present worldwide consumption of fossil energy. Photocatalysts are of fundamental interest for sustainable energy research because they provide a viable route for converting solar...... energy into chemical bonds. By means of Transmission Electron Microscopy (TEM) it is possible to gain insight in the fundamentals of their reaction mechanisms, chemical behaviour, structure and morphology before, during and after reaction using in situ investigations. In particular, the environmental TEM...... the microscope that allows electron microscopy under nonconventional TEM conditions and new kinds of in situ spectroscopy....

  18. Tem holder for sample transfer under reaction conditions

    DEFF Research Database (Denmark)

    Damsgaard, Christian Danvad; Zandbergen, Henny W.; Wagner, Jakob Birkedal

    Environmental transmission electron microscopy (ETEM) studies are usually performed using conventional sample holders in a dedicated ETEM [1] or in a traditional TEM by use of a dedicated high-pressure cell sample holder [2]. In both cases, the setup defines the conditions regarding gas, pressure......]. Furthermore, dedicated transfer holders have been used to transfer catalyst samples between reactor set-ups and TEM at room temperature in inert atmosphere [5]. To take the full advantage of complementary in situ techniques, transfer under reactions conditions is essential. This study introduces the in situ...... transfer concept by use of a dedicated TEM transfer holder capable of enclosing the sample in a gaseous environment at temperatures up to approx. 900C. By oxidation and reduction experiments of Cu nanoparticles it is shown possible to keep the reaction conditions during transfer outside the microscope...

  19. Oxidation in ceria infiltrated metal supported SOFCs – A TEM investigation

    DEFF Research Database (Denmark)

    Knibbe, Ruth; Wang, Hsiang-Jen; Blennow Tullmar, Peter

    2013-01-01

    electron microscopy (TEM) techniques including energy-dispersive X-ray spectroscopy and electron energy-loss spectroscopy of focus ion beamed TEM samples. The infiltrated CGO is predominately converted into CeFeO3 after high temperature processing, protecting the alloy. A thin layer of Cr-oxide is observed...

  20. Electron microscopy of nanostructured semiconductor materials

    International Nuclear Information System (INIS)

    Neumann, Wolfgang

    2003-01-01

    For various material systems of low dimensions, including multilayers, islands, and quantum dots, the potential applicability of transmission electron microscopy (TEM) is demonstrated. Conventional TEM is applied to elucidate size, shape, and arrangement of nanostructures, whereas high-resolution imaging is used for visualizing their atomic structure. In addition, microchemical peculiarities of the nanoscopic objects are investigated by analytical TEM techniques (energy-filtered TEM, energy-dispersive X-ray spectroscopy)

  1. Application of TEM to highly reactive metals

    International Nuclear Information System (INIS)

    Sherry, W.M.; Prinz, F.

    1982-01-01

    In the following a method for the preparation and observation of sodium TEM specimens and the first TEM micrograph ever to be published on the dislocation microstructure of sodium are reported. (orig./IHOE) [de

  2. Suspended DNA structural characterization by TEM diffraction

    KAUST Repository

    Marini, Monica

    2017-12-01

    In this work, micro-fabrication, super-hydrophobic properties and a physiologically compatible preparation step are combined and tailored to obtain background free biological samples to be investigated by Transmission Electron Microscopy (TEM) diffraction technique. The validation was performed evaluating a well-known parameter such as the DNA interbases value. The diffraction spacing measured is in good agreement with those obtained by HRTEM direct metrology and by traditional X-Ray diffraction. This approach addresses single molecule studies in a simplified and reproducible straightforward way with respect to more conventional and widely used techniques. In addition, it overcomes the need of long and elaborated samples preparations: the sample is in its physiological environment and the HRTEM data acquisition occurs without any background interference, coating, staining or additional manipulation. The congruence in the results reported in this paper makes the application of this approach extremely promising towards those molecules for which crystallization remains a hurdle, such as cell membrane proteins and fibrillar proteins.

  3. Suspended DNA structural characterization by TEM diffraction

    KAUST Repository

    Marini, Monica; Allione, Marco; Lopatin, Sergei; Moretti, Manola; Giugni, Andrea; Torre, Bruno; Di Fabrizio, Enzo M.

    2017-01-01

    In this work, micro-fabrication, super-hydrophobic properties and a physiologically compatible preparation step are combined and tailored to obtain background free biological samples to be investigated by Transmission Electron Microscopy (TEM) diffraction technique. The validation was performed evaluating a well-known parameter such as the DNA interbases value. The diffraction spacing measured is in good agreement with those obtained by HRTEM direct metrology and by traditional X-Ray diffraction. This approach addresses single molecule studies in a simplified and reproducible straightforward way with respect to more conventional and widely used techniques. In addition, it overcomes the need of long and elaborated samples preparations: the sample is in its physiological environment and the HRTEM data acquisition occurs without any background interference, coating, staining or additional manipulation. The congruence in the results reported in this paper makes the application of this approach extremely promising towards those molecules for which crystallization remains a hurdle, such as cell membrane proteins and fibrillar proteins.

  4. Complete Tem-Tomography: 3D Structure of Gems Cluster

    Science.gov (United States)

    Matsuno, J.; Miyake, A.; Tsuchiyama, A.; Messenger, S.; Nakamura-Messenger, K.

    2015-01-01

    GEMS (glass with embedded metal and sulfide) grains in interplanetary dust particles (IDPs) are considered to be one of the ubiquitous and fundamental building blocks of solids in the Solar System. They have been considered to be interstellar silicate dust that survived various metamorphism or alteration processes in the protoplanetary disk but the elemental and isotopic composition measurements suggest that most of them have been formed in the protoplanetary disk as condensates from high temperature gas. This formation model is also supported by the formation of GEMS-like grains with respect to the size, mineral assemblage, texture and infrared spectrum by condensation experiments from mean GEMS composition materials. Previous GEMS studies were performed only with 2D observation by transmission electron microscopy (TEM) or scanning TEM (STEM). However, the 3D shape and structure of GEMS grains and the spatial distribution of Fe/FeS's has critical information about their formation and origin. Recently, the 3D structure of GEMS grains in ultrathin sections of cluster IDPs was revealed by electron tomography using a TEM/STEM (JEM-2100F, JEOL). However, CT images of thin sections mounted on Cu grids acquired by conventional TEM-tomography are limited to low tilt angles (e. g., less than absolute value of 75 deg. In fact, previous 3D TEM observations of GEMS were affected by some artifacts related to the limited tilt range in the TEM used. Complete tomographic images should be acquired by rotating the sample tilt angle over a range of more than absolute value of 80 deg otherwise the CT images lose their correct structures. In order to constrain the origin and formation process of GEMS grains more clearly, we performed complete electron tomography for GEMS grains. Here we report the sample preparation method we have developed for this study, and the preliminary results.

  5. Proceedings of 11. Conference on Electron Microscopy of Solids

    International Nuclear Information System (INIS)

    2002-01-01

    The conference is the cyclically organised discussion forum on problems connected with application of different electron microscopy techniques for the study of solid state materials. The main topics of 11 conference on Electron Microscopy of Solids held in Krynica (PL) in 2002 was: application of TEM in materials science; analytical techniques and orientation imaging in materials science; high resolution TEM in electronic materials; TEM and SEM application in ceramic and composites; advanced TEM techniques; advanced analytical and orientation imaging techniques; application of TEM in investigations of amorphous and nanocrystalline material; Intermetallic and superalloys; TEM application in martensite alloys; TEM and SEM application in research of iron base alloys; TEM studies of deformed alloys; TEM application in thin films and surface layer studies; TEM and SEM application in materials science

  6. Quantitative phase imaging and differential interference contrast imaging for biological TEM

    International Nuclear Information System (INIS)

    Allman, B.E.; McMahon, P.J.; Barone-Nugent, E.D.; Nugent, E.D.

    2002-01-01

    Full text: Phase microscopy is a central technique in science. An experienced microscopist uses this effect to visualise (edge) structure within transparent samples by slightly defocusing the microscope. Although widespread in optical microscopy, phase contrast transmission electron microscopy (TEM) has not been widely adopted. TEM for biological specimens has largely relied on staining techniques to yield sufficient contrast. We show here a simple method for quantitative TEM phase microscopy that quantifies this phase contrast effect. Starting with conventional, digital, bright field images of the sample, our algorithm provides quantitative phase information independent of the sample's bright field intensity image. We present TEM phase images of a range of stained and unstained, biological and material science specimens. This independent phase and intensity information is then used to emulate a range of phase visualisation images familiar to optical microscopy, e.g. differential interference contrast. The phase images contain features not visible with the other imaging modalities. Further, if the TEM samples have been prepared on a microtome to a uniform thickness, the phase information can be converted into refractive index structure of the specimen. Copyright (2002) Australian Society for Electron Microscopy Inc

  7. In situ TEM electromechanical testing of nanowires and nanotubes.

    Science.gov (United States)

    Espinosa, Horacio D; Bernal, Rodrigo A; Filleter, Tobin

    2012-11-05

    The emergence of one-dimensional nanostructures as fundamental constituents of advanced materials and next-generation electronic and electromechanical devices has increased the need for their atomic-scale characterization. Given its spatial and temporal resolution, coupled with analytical capabilities, transmission electron microscopy (TEM) has been the technique of choice in performing atomic structure and defect characterization. A number of approaches have been recently developed to combine these capabilities with in-situ mechanical deformation and electrical characterization in the emerging field of in-situ TEM electromechanical testing. This has enabled researchers to establish unambiguous synthesis-structure-property relations for one-dimensional nanostructures. In this article, the development and latest advances of several in-situ TEM techniques to carry out mechanical and electromechanical testing of nanowires and nanotubes are reviewed. Through discussion of specific examples, it is shown how the merging of several microsystems and TEM has led to significant insights into the behavior of nanowires and nanotubes, underscoring the significant role in-situ techniques play in the development of novel nanoscale systems and materials. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Correlation of simulated TEM images with irradiation induced damage

    International Nuclear Information System (INIS)

    Schaeublin, R.; Almeida, P. de; Almazouzi, A.; Victoria, M.

    2000-01-01

    Crystal damage induced by irradiation is investigated using transmission electron microscopy (TEM) coupled to molecular dynamics (MD) calculations. The displacement cascades are simulated for energies ranging from 10 to 50 keV in Al, Ni and Cu and for times of up to a few tens of picoseconds. Samples are then used to perform simulations of the TEM images that one could observe experimentally. Diffraction contrast is simulated using a method based on the multislice technique. It appears that the cascade induced damage in Al imaged in weak beam exhibits little contrast, which is too low to be experimentally visible, while in Ni and Cu a good contrast is observed. The number of visible clusters is always lower than the actual one. Conversely, high resolution TEM (HRTEM) imaging allows most of the defects contained in the sample to be observed, although experimental difficulties arise due to the low contrast intensity of the smallest defects. Single point defects give rise in HTREM to a contrast that is similar to that of cavities. TEM imaging of the defects is discussed in relation to the actual size of the defects and to the number of clusters deduced from MD simulations

  9. TEM specimen preparation of semiconductor-PMMA-metal interfaces

    International Nuclear Information System (INIS)

    Thangadurai, P.; Lumelsky, Yulia; Silverstein, Michael S.; Kaplan, Wayne D.

    2008-01-01

    Transmission electron microscopy (TEM) cross-section specimens of PMMA in contact with gold and Si were prepared by focused ion beam (FIB) and compared with plan-view PMMA specimens prepared by a dip-coating technique. The specimens were characterized by TEM and electron energy loss spectroscopy (EELS). In the cross-section specimens, the thin films of PMMA were located in a Si-PMMA-Au multilayer. Different thicknesses of PMMA films were spin-coated on the Si substrates. The thickness of the TEM specimens prepared by FIB was estimated using EELS to be 0.65 of the plasmon mean-free-path. Along the PMMA-Au interface, Au particle diffusion into the PMMA was observed, and the size of the Au particles was in the range of 2-4 nm. Dip-coating of PMMA directly on Cu TEM grids resulted in thin specimens with a granular morphology, with a thickness of 0.58 of the plasmon mean-free-path. The dip-coated specimens were free from ion milling induced artifacts, and thus serve as control specimens for comparison with the cross-sectioned specimens prepared by FIB

  10. TEM sample preparation by femtosecond laser machining and ion milling for high-rate TEM straining experiments

    Energy Technology Data Exchange (ETDEWEB)

    Voisin, Thomas; Grapes, Michael D. [Dept. of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218 (United States); Zhang, Yong [Dept. of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218 (United States); Lorenzo, Nicholas; Ligda, Jonathan; Schuster, Brian [US Army Research Laboratory, Aberdeen Proving Ground, Aberdeen, MD 21005 (United States); Weihs, Timothy P. [Dept. of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218 (United States)

    2017-04-15

    To model mechanical properties of metals at high strain rates, it is important to visualize and understand their deformation at the nanoscale. Unlike post mortem Transmission Electron Microscopy (TEM), which allows one to analyze defects within samples before or after deformation, in situ TEM is a powerful tool that enables imaging and recording of deformation and the associated defect motion during mechanical loading. Unfortunately, all current in situ TEM mechanical testing techniques are limited to quasi-static strain rates. In this context, we are developing a new test technique that utilizes a rapid straining stage and the Dynamic TEM (DTEM) at the Lawrence Livermore National Laboratory (LLNL). The new straining stage can load samples in tension at strain rates as high as 4×10{sup 3}/s using two piezoelectric actuators operating in bending while the DTEM at LLNL can image in movie mode with a time resolution as short as 70 ns. Given the piezoelectric actuators are limited in force, speed, and displacement, we have developed a method for fabricating TEM samples with small cross-sectional areas to increase the applied stresses and short gage lengths to raise the applied strain rates and to limit the areas of deformation. In this paper, we present our effort to fabricate such samples from bulk materials. The new sample preparation procedure combines femtosecond laser machining and ion milling to obtain 300 µm wide samples with control of both the size and location of the electron transparent area, as well as the gage cross-section and length. - Highlights: • Tensile straining TEM specimens made by femtosecond laser machining and ion milling. • Accurate positioning of the electron transparent area within a controlled gauge region. • Optimization of femtosecond laser and ion milling parameters. • Fast production of numerous samples with a highly repeatable geometry.

  11. Microfabricated Nanofluidic cells for in situ liquid TEM

    DEFF Research Database (Denmark)

    Laganà, Simone

    Over the last decade, transmission electron microscopy (TEM) has been revolutionized not only by the introduction of new and very sophisticated hardware for improved resolution, such as aberration correctors and monochromators, but also by the improvement of new methods that have provided more than......, allowing quantitative and high-precision acquisition of liquid thickness maps, high resolution observations and meaningful information about synthesis of NPs from metal precursor solutions in confined space. Finally, a new concept device based on a Si3N4 membrane for plunge freezing fixation, which enables...

  12. TEM Imaging of Mass-selected Polymer Molecules

    International Nuclear Information System (INIS)

    Nasibulin, Albert G.; Kauppinen, Esko I.; Thomson, Bruce A.; Fernandez de la Mora, J.

    2002-01-01

    Polyethylene glycol (PEG) molecules with masses below 1300 amu are electrosprayed (ES) from solution, mobility-selected at high resolution in a differential mobility analyzer (DMA), collected on a grid and imaged by transmission electron microscopy (ES-DMA-TEM). The DMA resolves individual n-mers, and selects only one out of the many present in the original sample. Ion identity is established from parallel mass spectra (ES-MS). The images reveal spherical particles 1.46 nm in diameter, in good agreement with the known ion mass and bulk density. The DMA-selection technique opens new paths for the study of very small particles

  13. Global gyrokinetic simulations of TEM microturbulence

    Science.gov (United States)

    Vernay, T.; Brunner, S.; Villard, L.; McMillan, B. F.; Jolliet, S.; Bottino, A.; Görler, T.; Jenko, F.

    2013-07-01

    Global gyrokinetic simulations of electrostatic temperature-gradient-driven trapped-electron-mode (TEM) turbulence using the δf particle-in-cell code ORB5 are presented. The electron response is either fully kinetic or hybrid, i.e. considering kinetic trapped and adiabatic passing electrons. A linear benchmark in the TEM regime against the Eulerian-based code GENE is presented. Two different methods for controlling the numerical noise, based, respectively, on a Krook operator and a so-called coarse-graining approach, are discussed and successfully compared. Both linear and non-linear studies are carried out for addressing the issue of finite-ρ*-effects and finite electron collisionality on TEM turbulence. Electron collisions are found to damp TEMs through the detrapping process, while finite-ρ*-effects turn out to be important in the non-linear regime but very small in the linear regime. Finally, the effects of zonal flows on TEM turbulence are briefly considered as well and shown to be unimportant in the temperature-gradient-driven TEM regime. Consistently, basically no difference is found between linear and non-linear critical electron temperature gradients in the TEM regime.

  14. TEMS: results of a specialist centre.

    Science.gov (United States)

    Flexer, S M; Durham-Hall, A C; Steward, M A; Robinson, J M

    2014-06-01

    Transanal endoscopic microsurgery (TEMS) is becoming more widespread due to the increasing body of evidence to support its role. Previous published data has reported recurrence rates in excess of 10% for benign polyps after TEMS. Bradford Royal Infirmary is a tertiary referral centre for TEMS and early rectal cancer in the UK. Data for all TEMS operations were entered into a prospective database over a 7-year period. Demographic data, complications and recurrence rates were recorded. Both benign adenomas and malignant lesions were included. A total of 164 patients (65% male), with a mean age of 68 years were included; 114 (70%) of the lesions resected were benign adenomas, and 50 (30%) were malignant lesions. Median polyp size was 4 (range 0.6-14.5) cm. Mean length of operation was 55 (range 10-120) min. There were no recurrences in any patients with a benign adenoma resected; two patients with malignant lesions developed recurrences. Three intra-operative complications were recorded, two rectal perforations (repaired primarily, one requiring defunctioning stoma), and a further patient suffered a blood loss of >300 ml requiring transfusion. Six patients developed strictures requiring dilation either endoscopically or under anaesthetic in the post-operative period. We have demonstrated that TEMS procedures performed in a specialist centre provide low rates of both recurrence and complication. Within a specialist centre, TEMS surgery should be offered to all patients for rectal lesions, both benign and malignant, that are amenable to TEMS.

  15. Recent advances in cryo-TEM imaging of soft lipid nanoparticles

    DEFF Research Database (Denmark)

    Helvig, Shen Yu; Mat Azmi, Intan Diana Binti; Moghimi, Seyed Moien

    2015-01-01

    Cryo-transmission electron microscopy (Cryo-TEM), and its technological variations thereof, have become a powerful tool for detailed morphological characterization and 3D tomography of soft lipid and polymeric nanoparticles as well as biological materials such as viruses and DNA without chemical...... fixation. Here, we review and discuss recent advances in Cryo-TEM analysis of lipid-based drug nanocarriers with particular emphasis on morphological and internal nanostructure characterization of lyotropic liquid crystalline nanoparticles such as cubosomes and hexosomes....

  16. In situ TEM observations of unusual nanocrystallization in a Ti-based bulk metallic glass

    International Nuclear Information System (INIS)

    Yan, M.; Wang, D.J.; Shen, J.; Qian, M.

    2011-01-01

    In situ transmission electron microscopy (TEM) has been used to witness the nanocrystallization of amorphous Ti 42.5 Cu 40 Zr 10 Ni 5 Sn 2.5 . A crystallization front exists to separate the TEM sample into two parts with different thermal stabilities. The number density of the crystallization products varies significantly, with the precipitate sizes ranging from a few nanometres to ∼100 nm. Detailed TEM analysis suggests that oxygen is the most likely reason for realizing the unusual nanocrystallization. External thermal analysis also indicates that oxygen affects the crystallization.

  17. Preparation of TEM specimen by cross-section technique

    International Nuclear Information System (INIS)

    Hamada, Shozo

    1986-01-01

    Transmission electron microscopy (TEM) is applied to the direct observation of the depth dependent damage structure in ion-irradiated stainless steel by using the cross-section technique; obtaining the TEM specimen from a slice of the irradiated stainless steel with thick Ni plating. Here has been developed the specimen preparation method of cross-section technique without heat treatment, which was necessary in the conventional method to strengthen the bonding between Ni and stainless steel. Nickel plating with good bonding to stainless steel is enabled by the following manner. First, the irradiated stainless steel is immersed in the Wood's nickel solution at room temperature for 60s to activate the surface, followed by the stricking for 300s at a current density of 300 A/m 2 in the solution to make fine and homogeneous nucleation of Ni on the stainless steel. Then, the sample is plated with Ni in the Watt's nickel plating solution at 333 K with current density of 900 ∼ 1,000 A/m 2 . The TEM disc is obtained by mechanical slicing from the specimen with Ni plating of more than 3 mm thickness. Electropolishing is accomplished by using both Ballmann method and jet electropolishing to perforate the disc accurately at the aimed point for the observation of the damage structure. (author)

  18. Fluorescence microscopy.

    Science.gov (United States)

    Sanderson, Michael J; Smith, Ian; Parker, Ian; Bootman, Martin D

    2014-10-01

    Fluorescence microscopy is a major tool with which to monitor cell physiology. Although the concepts of fluorescence and its optical separation using filters remain similar, microscope design varies with the aim of increasing image contrast and spatial resolution. The basics of wide-field microscopy are outlined to emphasize the selection, advantages, and correct use of laser scanning confocal microscopy, two-photon microscopy, scanning disk confocal microscopy, total internal reflection, and super-resolution microscopy. In addition, the principles of how these microscopes form images are reviewed to appreciate their capabilities, limitations, and constraints for operation. © 2014 Cold Spring Harbor Laboratory Press.

  19. Analytical TEM investigations of nanoscale magnetic materials

    International Nuclear Information System (INIS)

    Meingast, A.

    2015-01-01

    Analytical transmission electron microscopy has been applied within this thesis to investigate several novel approaches to design and fabricate nanoscale magnetic materials. As the size of the features of interest rank in the sub-nanometer range, it is necessary to employ techniques with a resolution – both spatial and analytical – well below this magnitude. Only at this performance level it is possible to examine material properties, necessary for the further tailoring of materials. Within this work two key aspects have been covered: First, analytical TEM (transmission electron microscopy) investigations were carried out to get insight into novel magnetic materials with high detail. Second, new analytical and imaging possibilities enabled with the commissioning of the new ASTEM (Austrian scanning transmission electron microscope) were explored. The aberration corrected TITAN® microscope (© FEI Company) allows resolving features in scanning transmission mode (STEM) with 70 pm distance. Thereby, direct imaging of light elements in STEM mode by using the annular bright field method becomes possible. Facilitated through high beam currents within the electron probe, an increased acquisition speed of analytical signals is possible. For energy dispersive X-ray spectroscopy (EDXS) a new four detector disc geometry around the specimen was implemented, which increases the accessible collection angle. With the integration of the latest generation of image filter and electron spectrometer (GIF QuantumERS), electron energy loss spectroscopy (EELS) is boosted through the high acquisition speed and the dual spectroscopy mode. The high acquisition speed allows to record up to 1000 spectra per second and the possibility to record atomically resolved EELS maps is at hand. Hereby it is important to avoid beam damage and alteration of the material during imaging and analysis. With the simultaneous acquisition of the low and the high loss spectral region, an extended range for

  20. Accelerator-tem interface facility and application

    International Nuclear Information System (INIS)

    Li Ming; He Jun; Yang Zheng; Zhou Lin; Liu Chuansheng; Guo Liping; Jiang Changzhong; Yang Shibo; Fu Dejun; Fan Xiangjun; Liu Jiarui; Lee, J.C.

    2010-01-01

    An accelerator-TEM interface facility has been established at Wuhan University. The system consists of an H800 TEM linked to a 200 kV ion implanter and a 2 x 1.7 MV tandetron accelerator. Measures were taken to isolate the TEM from mechanical vibration transmitted from the ion beam lines and good resolution was maintained with the TEM machine when operated under high zoom modes during the ion implantation. Nitrogen ions at 115 keV were successfully transported from the implanter into the TEM chamber through the interface system, and the ion currents measured at the entrance of the TEM column were between 20 and 180 nA. Structural evolution caused by ion irradiation in Si, GaAs, nanocrystal Ag were observed in situ. The TEM sample could be tilted by 52 degree and for low energy ion irradiation, real time observation was realized. The in situ observation showed that the critical implant dose for amorphization of Si is 2 x 10 14 cm -2 and it became fully amorphized at 3 x 10 15 cm -2 . Amorphization of GaAs started at 1 x 10 14 cm -2 , whereas for nanocrystal Ag, the starting dose was 6 x 10 14 cm -2 . The nuclear material C276 samples implanted with 115 keV Ar+ was also studied and dislocation loops with sizes of 3-12 nm were clearly observed after implantation to doses higher than 1 x 10 15 cm -2 . The density of the loops increased with the increase in the implant dose and evolution to polycrystalline and amorphous structures were observed at 5 x 10 15 cm -2 and 3 x 10 16 cm -2 , respectively. An in situ RBS/C chamber has been installed on the transport line of the accelerator-TEM interface system. This makes it possible to in situ measure composition and location of impurities in the lattice of the implanted samples. In addition, a 50 kV low-energy gaseous ion generator was installed close to the TEM chamber, which facilitates in situ TEM observation of helium bubbles formed in materials by helium implantation. (authors)

  1. Illuminating Electron Microscopy of Photocatalysts

    DEFF Research Database (Denmark)

    Cavalca, Filippo

    Photocatalysts are of fundamental interest for sustainable energy research because of their wide range of applications and great potential for state of the art and future usages [1]. By means of Transmission Electron Microscopy (TEM) it is possible to give a deep insight in the structure, composi...

  2. Transmission electron microscopy of bone

    NARCIS (Netherlands)

    Everts, Vincent; Niehof, Anneke; Tigchelaar-Gutter, Wikky; Beertsen, Wouter

    2012-01-01

    This chapter describes procedures to process mineralized tissues obtained from different sources for transmission electron microscopy (TEM). Methods for fixation, resin embedding, staining of semi-thin sections and ultrathin sections are presented. In addition, attention will be paid to processing

  3. Accelerator-TEM interface facility and application

    International Nuclear Information System (INIS)

    Liu Chuansheng; Li Ming; He Jun; Yang Zheng; Zhou Lin; Wang Zesong; Guo Liping; Jiang Changzhong; Yang Shibo; Fu Dejun; Fan Xiangjun; Liu Jiarui; Lee J C

    2010-01-01

    An accelerator-TEM interface facility has been established at Wuhan University in 2008. The system consists of an H800 TEM linked to a 200 kV ion implanter and a 2 x 1.7 MV tandem accelerator. Nitrogen ions at 115 keV were successfully transported from the implanter into the TEM chamber through the interface system, and the ion currents measured at the entrance of the TEM column were between 20 and 180 nA. Structural evolution caused by ion irradiation in Si, GaAs, nanocrystal Ag was observed in situ. The in situ observation showed that the critical implantation dose for amorphization of Si is 10 14 cm -2 . The nuclear material C276 samples implanted with 115 keV Ar + was also studied, and dislocation loops sized at 3-12 nm were clearly observed after implantation to doses of over 1 x 10 15 cm -2 . The density of the loops increased with the dose. Evolution to polycrystalline and amorphous structures were observed at 5 x l0 15 cm -2 and 3 x 10 16 cm -2 , respectively. An in situ RBS/C chamber was installed on the transport line of the accelerator-TEM interface system. This enables in situ measurement of composition and location of the implanted species in lattice of the samples. In addition, a 50 kV low-energy gaseous ion generator was installed close to the TEM chamber, which facilitates in situ TEM observation of helium bubbles formed in helium-implanted materials. (authors)

  4. Nanoparticle sizing: a comparative study using atomic force microscopy, transmission electron microscopy, and ferromagnetic resonance

    International Nuclear Information System (INIS)

    Lacava, L.M.; Lacava, B.M.; Azevedo, R.B.; Lacava, Z.G.M.; Buske, N.; Tronconi, A.L.; Morais, P.C.

    2001-01-01

    Atomic force microscopy (AFM), transmission electron microscopy (TEM), and ferromagnetic resonance (FMR) were used to unfold the nanoparticle size of a ferrofluid sample. Compared to TEM, the AFM method showed a nanoparticle diameter (D m ) reduction of 20% and standard deviation (σ) increase of 15%. The differences in D m and σ were associated with the AFM tip and the nanoparticle concentration on the substrate

  5. Destructive interference of TEM and ITG turbulence

    International Nuclear Information System (INIS)

    Merz, F.; Jenko, F.

    2009-01-01

    Full text: Turbulence driven by ion temperature gradient (ITG) modes and trapped electron modes (TEMs) is generally considered the key mechanism for anomalous transport in fusion devices on ion scales. But while pure ITG and, to a lesser extent, also pure TEM turbulence have been studied in detail over the last years, not much is presently known about nonlinear interactions between ITG modes and TEMs, which are often present simultaneously in experimentally relevant situations. This important issue is addressed by means of linear and nonlinear gyrokinetic simulations with the GENE code. To examine the properties of the (linear) TEM and ITG instabilities in the (realistic) transitional regime, the GENE code is run as eigenvalue solver, which allows for a systematic study of dominant and subdominant modes. Corresponding nonlinear initial value computations show that the particle transport of the turbulent system can be completely suppressed if the two driving instabilities are active simultaneously. The direct comparison of the linear modes and the corresponding turbulent system reveals a coexistence of the two microinstabilities in a transitional regime even at the same wave number. The consequences of this dual turbulence drive for transport modeling is discussed. (author)

  6. Test for English Majors (TEM) in China

    Science.gov (United States)

    Jin, Yan; Fan, Jinsong

    2011-01-01

    The purpose of the Test for English Majors (TEM) is to measure the English proficiency of Chinese university undergraduates majoring in English Language and Literature and to examine whether these students meet the required levels of English language abilities as specified in the National College English Teaching Syllabus for English Majors…

  7. Direct Observations of Oxygen-induced Platinum Nanoparticle Ripening Studied by In Situ TEM

    DEFF Research Database (Denmark)

    Simonsen, Søren Bredmose; Chorkendorff, Ib; Dahl, Søren

    2010-01-01

    This study addresses the sintering mechanism of Pt nanoparticles dispersed on a planar, amorphous Al2O3 support as a model system for a catalyst for automotive exhaust abatement. By means of in situ transmission electron microscopy (TEM), the model catalyst was monitored during the exposure to 10...

  8. Nonlinear entropy transfer in ETG-TEM turbulence via TEM driven zonal flows

    International Nuclear Information System (INIS)

    Asahi, Yuuichi; Tsutsui, Hiroaki; Tsuji-Iio, Shunji; Ishizawa, Akihiro; Sugama, Hideo; Watanabe, Tomohiko

    2015-01-01

    Nonlinear interplay of the electron temperature gradient (ETG) modes and the trapped electron modes (TEMs) was investigated by means of gyrokinetic simulation. Focusing on the situation where both TEMs and ETG modes are linearly unstable, the effects of TEM-driven zonal flows on ETG turbulence were examined by means of entropy transfer analysis. In a statistically steady turbulence where the TEM driven zonal flows are dominant, it turned out that the zonal flows meditate the entropy transfer of the ETG modes from the low to high radial wavenumber regions. The successive entropy transfer broadens the potential fluctuation spectrum in the radial wavenumber direction. In contrast, in the situation where ETG modes are unstable but TEMs are stable, the pure ETG turbulence does not produce strong zonal flows, leading to a rather narrow spectrum in the radial wavenumber space and a higher transport level. (author)

  9. TEM characterization of UO2-Gd2O3 nuclear fuels synthesized by coprecipitation method

    International Nuclear Information System (INIS)

    Soldati, A.; Gana Watkins, I.; Menghini, J.; Prado, M.

    2013-01-01

    We present a micro and nano structural characterization of 4% weight doped Gd 2 O 3 -UO 2 pellet using Transmission Electron Microscopy (TEM). Agglomerate morphology and crystallite sizes were determined using light/dark field and high resolution (HR-TEM) images. Convergent beam Energy Dispersive Spectroscopy (EDS) and Electron Diffraction (ED) were used to evaluate sample composition and homogeneity, even at the nanometer scale. We obtained an average crystallite size of 90±20 nm. Moreover, from TEM-EDS analyses we determined the presence of Gadolinium in all the analyzed crystallites but with 25% variation among their concentrations. These results show the capability of TEM analysis to characterize a nuclear fuel pellet with burnable poisons nano structure and homogeneity.(author)

  10. Characterization of carbonated serpentine using XPS and TEM

    International Nuclear Information System (INIS)

    Schulze, Roland K.; Hill, Mary Ann; Field, Robert D.; Papin, Pallas A.; Hanrahan, Robert J.; Byler, Darrin D.

    2004-01-01

    With the increasing concentration volume of carbon dioxide in the atmosphere, there has been an increasing interest in carbon dioxide sequestration. One method is to store the carbon dioxide in mineral form, reacting solution dissolved CO 2 to precipitate carbonates. In order to understand whether or not such an endeavor is feasible, the carbonation reaction must first be understood. In this study, the surface of ground serpentine, untreated, heat treated and following a carbonation experiment, has been characterized using X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The results indicate that the mechanism for the reaction involves dissolution of the serpentine through the formation of an amorphous phase and subsequent precipitation of magnesite. The rate limiting step appears to be the diffusion of Mg out of the amorphous phase

  11. TEM analysis of fine sulphides dissolution and precipitation in steel

    International Nuclear Information System (INIS)

    Garbarz, B.; Marcisz, J.; Wojtas, J.

    2003-01-01

    Results of transmission electron microscopy (TEM) investigation of morphology, size distribution and chemistry of nano-inclusions formed in 4 mm thick laboratory steel ingots in as-cast condition and after heat treatment are reported. The investigated steel contained 0.11-0.14 C, 0.6 Mn, 0.25 Si, 0.22 Cu, 0.025-0.037 S (wt.%), and 80-115 ppm O and solidified at an average cooling rate of 250 K s -1 . In the as-cast specimens most nano-inclusions had a diameter in the range 10-100 nm with an average size of 30 nm. They were identified by microanalysis in thin foils as sulphides: MnS, (Mn,Cu)S, CuS and Cu 2 S. After a solution treatment of the thin ingots the re-precipitation of nano-sulphides was investigated

  12. Challenges in quantitative crystallographic characterization of 3D thin films by ACOM-TEM

    Energy Technology Data Exchange (ETDEWEB)

    Kobler, A. [Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen (Germany); Karlsruhe Nano Micro Facility (KNMF), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen (Germany); Kübel, C., E-mail: christian.kuebel@kit.edu [Institute of Nanotechnology (INT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen (Germany); Karlsruhe Nano Micro Facility (KNMF), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344, Eggenstein-Leopoldshafen (Germany)

    2017-02-15

    Automated crystal orientation mapping for transmission electron microscopy (ACOM-TEM) has become an easy to use method for the investigation of crystalline materials and complements other TEM methods by adding local crystallographic information over large areas. It fills the gap between high resolution electron microscopy and electron back scatter diffraction in terms of spatial resolution. Recent investigations showed that spot diffraction ACOM-TEM is a quantitative method with respect to sample parameters like grain size, twin density, orientation density and others. It can even be used in combination with in-situ tensile or thermal testing. However, there are limitations of the current method. In this paper we discuss some of the challenges and discuss solutions, e.g. we present an ambiguity filter that reduces the number of pixels with a ‘180° ambiguity problem’. For that an ACOM-TEM tilt series of nanocrystalline Pd thin films with overlapping crystallites was acquired and analyzed. - Highlights: • Tilt series of nanocrystalline Pd thin films. • Quantitative ACOM-TEM data processing, including a rotation map of crystallites. • Noise filter for orientation data: Ambiguity Filter and min. distance filter.

  13. A nonlinear filtering algorithm for denoising HR(S)TEM micrographs

    International Nuclear Information System (INIS)

    Du, Hongchu

    2015-01-01

    Noise reduction of micrographs is often an essential task in high resolution (scanning) transmission electron microscopy (HR(S)TEM) either for a higher visual quality or for a more accurate quantification. Since HR(S)TEM studies are often aimed at resolving periodic atomistic columns and their non-periodic deviation at defects, it is important to develop a noise reduction algorithm that can simultaneously handle both periodic and non-periodic features properly. In this work, a nonlinear filtering algorithm is developed based on widely used techniques of low-pass filter and Wiener filter, which can efficiently reduce noise without noticeable artifacts even in HR(S)TEM micrographs with contrast of variation of background and defects. The developed nonlinear filtering algorithm is particularly suitable for quantitative electron microscopy, and is also of great interest for beam sensitive samples, in situ analyses, and atomic resolution EFTEM. - Highlights: • A nonlinear filtering algorithm for denoising HR(S)TEM images is developed. • It can simultaneously handle both periodic and non-periodic features properly. • It is particularly suitable for quantitative electron microscopy. • It is of great interest for beam sensitive samples, in situ analyses, and atomic resolution EFTEM

  14. Contact microscopy with synchrotron radiation

    International Nuclear Information System (INIS)

    Panessa-Warren, B.J.

    1985-10-01

    Soft x-ray contact microscopy with synchrotron radiation offers the biologist and especially the microscopist, a way to morphologically study specimens that could not be imaged by conventional TEM, STEM or SEM methods (i.e. hydrated samples, samples easily damaged by an electron beam, electron dense samples, thick specimens, unstained low contrast specimens) at spatial resolutions approaching those of the TEM, with the additional possibility to obtain compositional (elemental) information about the sample as well. Although flash x-ray sources offer faster exposure times, synchrotron radiation provides a highly collimated, intense radiation that can be tuned to select specific discrete ranges of x-ray wavelengths or specific individual wavelengths which optimize imaging or microanalysis of a specific sample. This paper presents an overview of the applications of x-ray contact microscopy to biological research and some current research results using monochromatic synchrotron radiation to image biological samples. 24 refs., 10 figs

  15. High-resolution electron microscopy

    CERN Document Server

    Spence, John C H

    2013-01-01

    This new fourth edition of the standard text on atomic-resolution transmission electron microscopy (TEM) retains previous material on the fundamentals of electron optics and aberration correction, linear imaging theory (including wave aberrations to fifth order) with partial coherence, and multiple-scattering theory. Also preserved are updated earlier sections on practical methods, with detailed step-by-step accounts of the procedures needed to obtain the highest quality images of atoms and molecules using a modern TEM or STEM electron microscope. Applications sections have been updated - these include the semiconductor industry, superconductor research, solid state chemistry and nanoscience, and metallurgy, mineralogy, condensed matter physics, materials science and material on cryo-electron microscopy for structural biology. New or expanded sections have been added on electron holography, aberration correction, field-emission guns, imaging filters, super-resolution methods, Ptychography, Ronchigrams, tomogr...

  16. In situ TEM observation of the growth and decomposition of monoclinic W18O49 nanowires

    International Nuclear Information System (INIS)

    Chen, C L; Mori, H

    2009-01-01

    The growth of monoclinic W 18 O 49 nanowires by heat treatment of a tungsten filament at ∼873 K and the decomposition of these nanowires under 200 keV electron irradiation at ∼1023 K have been investigated using in situ transmission electron microscopy (TEM). In situ TEM observation of the growth confirmed the vapor-solid growth mechanism of the monoclinic W 18 O 49 nanowires. In situ irradiation experiments revealed the formation of metallic bcc tungsten from monoclinic W 18 O 49 nanowires under 200 keV electron irradiation.

  17. TEM and Moessbauer Study of Nano Sized Fe2MnAl Flakes

    International Nuclear Information System (INIS)

    Vinesh, A.; Sudheesh, V. D.; Lakshmi, N.; Venugopalan, K.

    2011-01-01

    Magnetic and structural properties of L21 ordered Fe 2 MnAl Heusler alloy have been studied by X-ray diffraction, Transmission electron microscopy (TEM), Moessbauer spectroscopy and DC magnetization. Structural texturing induced by ball milling is destroyed on heating while Moessbauer and DC magnetization studies show magnetic texturing persists after thermal treatment. TEM shows large distribution in particle size with an average size of 27 nm. Thermal annealing of ball milled sample results L2 1 ordering and the needle shaped particle contributes spin texturing.

  18. Polymersomes, smaller than you think: ferrocene as a TEM probe to determine core structure

    International Nuclear Information System (INIS)

    Johnston, A. H.; Dalton, P. D.; Newman, T. A.

    2010-01-01

    By incorporating ferrocene into the hydrophobic membrane of PEG-b-PCL polymersome nanoparticles it is possible to selectively visualize their core using Transmission Electron Microscopy (TEM). Two different sizes of ferrocene-loaded polymersomes with mean hydrodynamic diameters of approximately 40 and 90 nm were prepared. Image analysis of TEM pictures of these polymersomes found that the mean diameter of the core was 4-5 times smaller than the mean hydrodynamic diameter. The values obtained also allow the surface diameter and internal volume of the core to be calculated.

  19. SANS and TEM studies of carbide precipitation and creep damage in type 304 stainless steel

    International Nuclear Information System (INIS)

    Yoo, M.H.; Ogle, J.C.; Schneibel, J.H.; Swindeman, R.W.

    1984-01-01

    Small-angle neutron scattering (SANS) and transmission electron microscopy (TEM) studies were performed to characterize the carbide (M 23 C 6 ) precipitation and creep damage induced in type 304 stainless steel in the primary creep stage. The size distribution of matrix carbides evaluated from SANS analyses was consistent with TEM data, and the expected accelerated kinetics of precipitation under applied stress was confirmed. Additional SANS measurements after the postcreep solution annealing were made in order to differentiate cavities from the carbides. Potential advantages and difficulties associated with characterization of creep-induced cavitation by the SANS techniques are discussed

  20. Determination of Size Distributions in Nanocrystalline Powders by TEM, XRD and SAXS

    DEFF Research Database (Denmark)

    Jensen, Henrik; Pedersen, Jørgen Houe; Jørgensen, Jens Erik

    2006-01-01

    Crystallite size distributions and particle size distributions were determined by TEM, XRD, and SAXS for three commercially available TiO2 samples and one homemade. The theoretical Guinier Model was fitted to the experimental data and compared to analytical expressions. Modeling of the XRD spectra...... the size distribution obtained from the XRD experiments; however, a good agreement was obtained between the two techniques. Electron microscopy, SEM and TEM, confirmed the primary particle sizes, the size distributions, and the shapes obtained by XRD and SAXS. The SSEC78 powder and the commercially...

  1. TEM analysis of a friction stir-welded butt joint of Al-Si-Mg alloys

    International Nuclear Information System (INIS)

    Cabibbo, M.; Meccia, E.; Evangelista, E.

    2003-01-01

    The microstructure evolution of a joint of Al-Si-Mg alloys A6056-T4 and A6056-T6 has been characterized by transmission electron microscopy (TEM). Metallurgical investigations, hardness and mechanical tests were also performed to correlate the TEM investigations to the mechanical properties of the produced friction stir-welded butt joint. After friction stir-welding thermal treatment has been carried out at 530 deg. C followed by ageing at 160 deg. C (T6). The base material (T4) and the heat-treated one (T6) were put in comparison showing a remarkable ductility reduction of the joint after T6 treatment

  2. TEM characterization of nanodiamond thin films.

    Energy Technology Data Exchange (ETDEWEB)

    Qin, L.-C.; Zhou, D.; Krauss, A. R.; Gruen, D. M.; Chemistry

    1998-05-01

    The microstructure of thin films grown by microwave plasma-enhanced chemical vapor deposition (MPCVD) from fullerene C{sub 60} precursors has been characterized by scanning electron microscopy (SEM), selected-area electron diffraction (SAED), bright-field electron microscopy, high-resolution electron microscopy (HREM), and parallel electron energy loss spectroscopy (PEELS). The films are composed of nanosize crystallites of diamond, and no graphitic or amorphous phases were observed. The diamond crystallite size measured from lattice images shows that most grains range between 3-5 nm, reflecting a gamma distribution. SAED gave no evidence of either sp2-bonded glassy carbon or sp3-bonded diamondlike amorphous carbon. The sp2-bonded configuration found in PEELS was attributed to grain boundary carbon atoms, which constitute 5-10% of the total. Occasionally observed larger diamond grains tend to be highly faulted.

  3. TEM-EELS: A personal perspective

    International Nuclear Information System (INIS)

    Egerton, R.F.

    2012-01-01

    The development of electron energy-loss spectroscopy in a transmission electron microscope (TEM-EELS) is illustrated through personal anecdote, highlighting some of the basic principles, instrumentation and personalities involved. The current state of the art is reviewed, together with some challenges for the future. -- Highlights: ► The history of EELS instrumentation is reviewed in a lighthearted manner. ► The current state of the art is summarized, together with some future possibilities. ► A couple of related mathematical puzzles are offered as a challenge to the reader.

  4. TEM investigations of laser ablated particles

    International Nuclear Information System (INIS)

    Fliegel, D.; Dundas, S.; Kosler, J.; Klementova, M.

    2009-01-01

    Full text: Laser ablation inductively coupled plasma mass spectrometry suffers from fractionation effects hindering a non matrix matched calibration strategy. Different reasons for elemental fractionation that are related to the laser ablation, the transport and the vaporization in the plasma are discussed. One major question to be addressed linked to the vaporization yield in the ICP is in which of mineralogical phase the different ablated particle sizes enter the plasma. This contribution will investigate particles generated by a 213 nm laser from different samples such as minerals and alloys with respect to their chemical and phase compositions using high resolution TEM. (author)

  5. Present status and future prospects of spherical aberration corrected TEM/STEM for study of nanomaterials

    International Nuclear Information System (INIS)

    Tanaka, Nobuo

    2008-01-01

    The present status of Cs-corrected TEM/STEM is described from the viewpoint of the observation of nanomaterials. Characteristic features in TEM and STEM are explained using the experimental data obtained by our group and other research groups. Cs correction up to the 3rd-order aberration of an objective lens has already been established and research interest is focused on correcting the 5th-order spherical aberration and the chromatic aberration in combination with the development of a monochromator below an electron gun for smaller point-to-point resolution in optics. Another fundamental area of interest is the limitation of TEM and STEM resolution from the viewpoint of the scattering of electrons in crystals. The minimum size of the exit-wave function below samples undergoing TEM imaging is determined from the calculation of scattering around related atomic columns in the crystals. STEM does not have this limitation because the resolution is, in principle, determined by the probe size. One of the future prospects of Cs-corrected TEM/STEM is the possibility of extending the space around the sample holder by correcting the chromatic and spherical aberrations. This wider space will contribute to the ease of performing in situ experiments and various combinations of TEM and other analysis methods. High-resolution, in situ dynamic and 3D observations/analysis are the most important keywords in the next decade of high-resolution electron microscopy. (topical review)

  6. TEM Study of SAFARI-2000 Aerosols

    Science.gov (United States)

    Buseck, Peter R.

    2004-01-01

    The aim of our research was to obtain data on the chemical and physical properties of individual aerosol particles from biomass smoke plume s in southern Africa and from air masses in the region that are affec ted by the smoke. We used analytical transmission electron microscopy (ATEM), including energy-dispersive X-ray spectrometry (EDS) and ele ctron energy-loss spectroscopy (EELS), and field-emission electron microscopy (FESEM) to study aerosol particles from several smoke and haz e samples and from a set of cloud samples.

  7. Transmission electron microscopy in micro-nanoelectronics

    CERN Document Server

    Claverie, Alain

    2013-01-01

    Today, the availability of bright and highly coherent electron sources and sensitive detectors has radically changed the type and quality of the information which can be obtained by transmission electron microscopy (TEM). TEMs are now present in large numbers not only in academia, but also in industrial research centers and fabs.This book presents in a simple and practical way the new quantitative techniques based on TEM which have recently been invented or developed to address most of the main challenging issues scientists and process engineers have to face to develop or optimize sem

  8. Detecting single-electron events in TEM using low-cost electronics and a silicon strip sensor.

    Science.gov (United States)

    Gontard, Lionel C; Moldovan, Grigore; Carmona-Galán, Ricardo; Lin, Chao; Kirkland, Angus I

    2014-04-01

    There is great interest in developing novel position-sensitive direct detectors for transmission electron microscopy (TEM) that do not rely in the conversion of electrons into photons. Direct imaging improves contrast and efficiency and allows the operation of the microscope at lower energies and at lower doses without loss in resolution, which is especially important for studying soft materials and biological samples. We investigate the feasibility of employing a silicon strip detector as an imaging detector for TEM. This device, routinely used in high-energy particle physics, can detect small variations in electric current associated with the impact of a single charged particle. The main advantages of using this type of sensor for direct imaging in TEM are its intrinsic radiation hardness and large detection area. Here, we detail design, simulation, fabrication and tests in a TEM of the front-end electronics developed using low-cost discrete components and discuss the limitations and applications of this technology for TEM.

  9. Visualization of arrangements of carbon atoms in graphene layers by Raman mapping and atomic-resolution TEM

    KAUST Repository

    Cong, Chunxiao

    2013-02-01

    In-plane and out-of-plane arrangements of carbon atoms in graphene layers play critical roles in the fundamental physics and practical applications of these novel two-dimensional materials. Here, we report initial results on the edge/crystal orientations and stacking orders of bi-and tri-layer graphene (BLG and TLG) from Raman spectroscopy and transmission electron microscopy (TEM) experiments performed on the same sample. We introduce a new method of transferring graphene flakes onto a normal TEM grid. Using this novel method, we probed the BLG and TLG flakes that had been previously investigated by Raman scattering with high-resolution (atomic) TEM.

  10. Characterization of crystallite morphology for doped strontium fluoride nanophosphors by TEM and XRD

    Energy Technology Data Exchange (ETDEWEB)

    O' Connell, J.H. [Centre for HRTEM, Nelson Mandela Metropolitan University, PO Box 77000, Port Elizabeth ZA6031 (South Africa); Lee, M.E., E-mail: Michael.lee@nmmu.ac.za [Centre for HRTEM, Nelson Mandela Metropolitan University, PO Box 77000, Port Elizabeth ZA6031 (South Africa); Yagoub, M.Y.A.; Swart, H.C.; Coetsee, E. [Department of Physics, University of the Free State, PO Box 339, Bloemfontein ZA9300 (South Africa)

    2016-01-01

    Crystallite morphology for Eu-doped and undoped SrF{sub 2} nanophosphors have been determined by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The values for average crystallite size obtained by the application of the Scherrer equation and the full width at half maximum (FWHM) values for XRD peaks are compared to the results obtained using the hollow cone dark field (HCDF) TEM imaging technique. In the case of the TEM analysis, a bimodal crystallite size distribution was revealed with one of the distributions having a measured range of crystallite sizes which was in good agreement with the XRD data. HCDF in combination with FIB specimen preparation was found to be a promising technique for the determination of crystallite size distributions in nanophosphors which might facilitate a better understanding of their scintillation properties.

  11. Characterization of crystallite morphology for doped strontium fluoride nanophosphors by TEM and XRD

    International Nuclear Information System (INIS)

    O'Connell, J.H.; Lee, M.E.; Yagoub, M.Y.A.; Swart, H.C.; Coetsee, E.

    2016-01-01

    Crystallite morphology for Eu-doped and undoped SrF_2 nanophosphors have been determined by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The values for average crystallite size obtained by the application of the Scherrer equation and the full width at half maximum (FWHM) values for XRD peaks are compared to the results obtained using the hollow cone dark field (HCDF) TEM imaging technique. In the case of the TEM analysis, a bimodal crystallite size distribution was revealed with one of the distributions having a measured range of crystallite sizes which was in good agreement with the XRD data. HCDF in combination with FIB specimen preparation was found to be a promising technique for the determination of crystallite size distributions in nanophosphors which might facilitate a better understanding of their scintillation properties.

  12. Observation of Pt-{100}-p(2×2-O reconstruction by an environmental TEM

    Directory of Open Access Journals (Sweden)

    Hengbo Li

    2016-06-01

    Full Text Available The surface structure of noble metal nanoparticles usually plays a crucial role during the catalytic process in the fields of energy and environment. It has been studied extensively by surface analytic methods, such as scanning tunneling microscopy. However, it is still challenging to secure a direct observation of the structural evolution of surfaces of nanocatalysts in reaction (gas and heating conditions at the atomic scale. Here we report an in-situ observation of atomic reconstruction on Pt {100} surfaces exposed to oxygen in an environmental transmission electron microscope (TEM. Our high-resolution TEM images revealed that Pt-{100}-p(2×2-O reconstruction occurs during the reaction between oxygen atoms and {100} facets. A reconstruction model was proposed, and TEM images simulated according to this model with different defocus values match the experimental results well.

  13. Quantitative TEM analysis of Al/Cu multilayer systems prepared by pulsed laser deposition

    DEFF Research Database (Denmark)

    Liu, Haihua; Pryds, Nini; Schou, Jørgen

    2010-01-01

    Thin films composed of alternating Al/Cu/Al layers were deposited on a (111) Si substrate using pulsed laser deposition (PLD). The thicknesses of the film and the individual layers, and the detailed internal structure within the layers were characterized by means of transmission electron microscopy...... for the formation of the first layer of nano-sized Al grains. The results demonstrate that the PLD technique is a powerful tool to produce nano-scale multilayered metal films with controllable thickness and grain sizes....... (TEM), high-resolution TEM (HRTEM), and energy-filtered TEM (EFTEM). Each Al or Cu layer consists of a single layer of nano-sized grains of different orientations. EFTEM results revealed a layer of oxide about 2 nm thick on the surface of the Si substrate, which is considered to be the reason...

  14. Environmental TEM in an Aberration Corrected Microscope

    DEFF Research Database (Denmark)

    Hansen, Thomas Willum; Wagner, Jakob Birkedal

    ‐resolution imaging. A gaseous atmosphere in the pole‐piece gap of the objective lens of the microscope alters both the incoming electron wave prior to interaction with the sample and the outgoing wave below the sample. Whereas conventional TEM samples are usually thin (below 10‐20 nm), the gas in the environmental...... the microscope column. The effects of gas on the electron wave in the objective lens are not well understood and needs further attention. Imaging samples with a simple geometry, such as gold particles on a flat graphene substrate and analyzing the variations in contrast, provides a means for understanding...... results from imaging in various elemental as well as di‐molecular gases and their effect on imaging and spectroscopy in the environmental transmission electron microscope....

  15. TEM investigations of microstructures of combustion aerosols

    International Nuclear Information System (INIS)

    Marquardt, A.; Hackfort, H.; Borchardt, J.; Schober, T.; Friedrich, J.

    1992-12-01

    In the incineration of organic material, apart from a series of gaseous pollutants, particulate pollutants or combustion aerosols also arise. The latter frequently consist of particles with a solid core of carbon to which a large number of inorganic and organic compounds are attached. These primarily include the polycyclic aromatic hydrocarbons (PAH) and their nitro-derivatives (NPAH), whose mutagenic or carcinogenic effect is known. The invisible particle sizes in the nanometer range, whose retention in the incineration off-gas is not state of the art, are of increasing significance for man and environment. On the one hand, they are deposited almost completely in the human lung. On the other hand, due to their fine dispersity they have along residence time in the atmosphere where they participate in chemical reactions and climatically significant processes. Important insights about the formation process of combustion aerosols are to be expected from the imaging of their microstructures in the transmission electron microscope (TEM). The present contribution describes the development and application of a representative sampling procedure for aerosols from a partial flow of flue gas from a fluidized-bed furnace. The method developed consists of electrically charging aerosol particles in situ and subsequently selectively precipitating them onto a microscope slide in an electric field. TEM studies of aerosol microstructures on the microscope slides revealed that in the combustion of petrol and heating oil under different combustion conditions in principle the same particle structures result, whereas in the incineration of used lubricating oil quite different particle structures were found. Results from the literature on aerosol microstructures in exhaust gases from petrol and diesel engines demonstrate agreement with the results of this study in the basic structure of the particles. (orig.) [de

  16. Strain study of gold nanomaterials as HR-TEM calibration standard.

    Science.gov (United States)

    Peng, X Y; Zhou, L Q; Li, X; Tao, X F; Ren, L L; Cao, W H; Xu, G F

    2015-12-01

    This work presents the use of high resolution electron microscopy (HREM) and geometric phase analysis (GPA) to measure the interplanar spacing and strain distribution of three gold nanomaterials, respectively. The results showed that the {111} strain was smaller than the {002} strain for any kind of gold materials at the condition of same measuring method. The 0.65% of {111} strain in gold film measured by HREM (0.26% measured by GPA) was smaller than the {111} strains in two gold particles. The presence of lattice strain was interpreted according to the growth mechanism of metallic thin film. It is deduced that the {111} interplanar spacing of the gold thin film is suitable for high magnification calibration of transmission electron microscopy (TEM) and the gold film is potential to be a new calibration standard of TEM. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. TEM-145 and TEM-146 β-lactamases produced by Escherichia coli ...

    African Journals Online (AJOL)

    GREGO

    2007-03-05

    Mar 5, 2007 ... Key words: Escherichia coli, plasmid-mediated, TEM β-lactamase. ... Enterobacteriaceae, the most prevalent mechanism of resistance to ... the production of a relatively inhibitor-resistant OXA-type β-lactamase .... and 8.6 as transcripts of the E. coli chromosomal AmpC .... Mode of action and mechanisms of.

  18. Challenges in quantitative crystallographic characterization of 3D thin films by ACOM-TEM.

    Science.gov (United States)

    Kobler, A; Kübel, C

    2017-02-01

    Automated crystal orientation mapping for transmission electron microscopy (ACOM-TEM) has become an easy to use method for the investigation of crystalline materials and complements other TEM methods by adding local crystallographic information over large areas. It fills the gap between high resolution electron microscopy and electron back scatter diffraction in terms of spatial resolution. Recent investigations showed that spot diffraction ACOM-TEM is a quantitative method with respect to sample parameters like grain size, twin density, orientation density and others. It can even be used in combination with in-situ tensile or thermal testing. However, there are limitations of the current method. In this paper we discuss some of the challenges and discuss solutions, e.g. we present an ambiguity filter that reduces the number of pixels with a '180° ambiguity problem'. For that an ACOM-TEM tilt series of nanocrystalline Pd thin films with overlapping crystallites was acquired and analyzed. Copyright © 2017. Published by Elsevier B.V.

  19. Coarsening of Pd nanoparticles in an oxidizing atmosphere studied by in situ TEM

    DEFF Research Database (Denmark)

    Simonsen, Søren Bredmose; Chorkendorff, Ib; Dahl, Søren

    2016-01-01

    The coarsening of supported palladium nanoparticles in an oxidizing atmosphere was studied in situ by means of transmission electron microscopy (TEM). Specifically, the Pd nanoparticles were dispersed on a planar and amorphous Al2O3 support and were observed during the exposure to 10 mbar technical...... for the Ostwald ripening process indicates that the observed change in the particle size distribution can be accounted for by wetting of the Al2O3 support by the larger Pd nanoparticles....

  20. TEM EDS analysis of epitaxially-grown self-assembled indium islands

    Directory of Open Access Journals (Sweden)

    Jasmine Sears

    2017-05-01

    Full Text Available Epitaxially-grown self-assembled indium nanostructures, or islands, show promise as nanoantennas. The elemental composition and internal structure of indium islands grown on gallium arsenide are explored using Transmission Electron Microscopy (TEM Energy Dispersive Spectroscopy (EDS. Several sizes of islands are examined, with larger islands exhibiting high (>94% average indium purity and smaller islands containing inhomogeneous gallium and arsenic contamination. These results enable more accurate predictions of indium nanoantenna behavior as a function of growth parameters.

  1. Graphene-based sample supports for in situ high-resolution TEM electrical investigations

    International Nuclear Information System (INIS)

    Westenfelder, B; Scholz, F; Meyer, J C; Biskupek, J; Algara-Siller, G; Lechner, L G; Kaiser, U; Kusterer, J; Kohn, E; Krill, C E III

    2011-01-01

    Specially designed transmission electron microscopy (TEM) sample carriers have been developed to enable atomically resolved studies of the heat-induced evolution of adsorbates on graphene and their influence on electrical conductivity. Here, we present a strategy for graphene-based carrier realization, evaluating its design with respect to fabrication effort and applications potential. We demonstrate that electrical current can lead to very high temperatures in suspended graphene membranes, and we determine that current-induced cleaning of graphene results from Joule heating.

  2. Advanced electron microscopy characterization of nanomaterials for catalysis

    Directory of Open Access Journals (Sweden)

    Dong Su

    2017-04-01

    Full Text Available Transmission electron microscopy (TEM has become one of the most powerful techniques in the fields of material science, inorganic chemistry and nanotechnology. In terms of resolutions, advanced TEM may reach a high spatial resolution of 0.05 nm, a high energy-resolution of 7 meV. In addition, in situ TEM can help researchers to image the process happened within 1 ms. This paper reviews the recent technical progresses of applying advanced TEM characterization on nanomaterials for catalysis. The text is organized based on the perspective of application: for example, size, composition, phase, strain, and morphology. The electron beam induced effect and in situ TEM are also introduced. I hope this review can help the scientists in related fields to take advantage of advanced TEM to their own researches. Keywords: Advanced TEM, Nanomaterials, Catalysts, In situ

  3. A-10/TF34 Turbine Engine Monitoring System (TEMS)

    Science.gov (United States)

    Christopher, R. G.

    1981-01-01

    The hardware and software development of the A-10/TF34 turbine engine monitoring system (TEMS) is described. The operation and interfaces of the A-10/TF34 TEMS hardware are discussed with particular emphasis on function, capabilities, and limitations. The TEMS data types are defined and the various data acquisition modes are explained. Potential data products are also discussed.

  4. Polarized Light Microscopy

    Science.gov (United States)

    Frandsen, Athela F.

    2016-01-01

    Polarized light microscopy (PLM) is a technique which employs the use of polarizing filters to obtain substantial optical property information about the material which is being observed. This information can be combined with other microscopy techniques to confirm or elucidate the identity of an unknown material, determine whether a particular contaminant is present (as with asbestos analysis), or to provide important information that can be used to refine a manufacturing or chemical process. PLM was the major microscopy technique in use for identification of materials for nearly a century since its introduction in 1834 by William Fox Talbot, as other techniques such as SEM (Scanning Electron Microscopy), FTIR (Fourier Transform Infrared spectroscopy), XPD (X-ray Powder Diffraction), and TEM (Transmission Electron Microscopy) had not yet been developed. Today, it is still the only technique approved by the Environmental Protection Agency (EPA) for asbestos analysis, and is often the technique first applied for identification of unknown materials. PLM uses different configurations in order to determine different material properties. With each configuration additional clues can be gathered, leading to a conclusion of material identity. With no polarizing filter, the microscope can be used just as a stereo optical microscope, and view qualities such as morphology, size, and number of phases. With a single polarizing filter (single polars), additional properties can be established, such as pleochroism, individual refractive indices, and dispersion staining. With two polarizing filters (crossed polars), even more can be deduced: isotropy vs. anisotropy, extinction angle, birefringence/degree of birefringence, sign of elongation, and anomalous polarization colors, among others. With the use of PLM many of these properties can be determined in a matter of seconds, even for those who are not highly trained. McCrone, a leader in the field of polarized light microscopy, often

  5. Use of atomic force microscopy and transmission electron microscopy for correlative studies of bacterial capsules.

    Science.gov (United States)

    Stukalov, Oleg; Korenevsky, Anton; Beveridge, Terry J; Dutcher, John R

    2008-09-01

    Bacteria can possess an outermost assembly of polysaccharide molecules, a capsule, which is attached to their cell wall. We have used two complementary, high-resolution microscopy techniques, atomic force microscopy (AFM) and transmission electron microscopy (TEM), to study bacterial capsules of four different gram-negative bacterial strains: Escherichia coli K30, Pseudomonas aeruginosa FRD1, Shewanella oneidensis MR-4, and Geobacter sulfurreducens PCA. TEM analysis of bacterial cells using different preparative techniques (whole-cell mounts, conventional embeddings, and freeze-substitution) revealed capsules for some but not all of the strains. In contrast, the use of AFM allowed the unambiguous identification of the presence of capsules on all strains used in the present study, including those that were shown by TEM to be not encapsulated. In addition, the use of AFM phase imaging allowed the visualization of the bacterial cell within the capsule, with a depth sensitivity that decreased with increasing tapping frequency.

  6. TEM investigation of plant-irradiated NPP bolt material

    International Nuclear Information System (INIS)

    Pakarinen, J.; Ehrnsten, U.; Keinaenen, H.; Karlsen, W.; Karlsen, T.

    2015-01-01

    Analytical transmission electron microscopy (ATEM) was used to examine irradiation-induced damage in material removed from two different bolts from two different nuclear power plants. One section came from a French PWR, was made of CW AISI 316, and included a section of the bolt that had accumulated a dose of approximately 15 dpa during 19 operation cycles at 350 - 390 C. degrees. Another section came from a VVER bolt that was removed from the plant due to indications found in non-destructive examinations (NDE). The VVER bolt was made of solution annealed titanium stabilized 0X18H10T (corresponding to Type AISI 321) and had accumulated a fluence of 2.9 dpa. During the removal of that bolt, it was found that the bolt washer had been inappropriately spot welded to the shielding plate during assembly. Destructive investigations showed that the bolt had two large intergranular cracks, and the TEM samples were prepared from the material adjacent to those cracks. The PWR bolt had not failed, although cracks in the bolts with a similar history had been found previously. The fluence for the cold-worked AISI 316 PWR bolt was estimated to be about 15 dpa. Both the examined bolts showed a clear radiation induced segregation of alloying elements at the grain boundaries (GB-RIS), the presence of dislocation loops, the formation of precipitates, and linear deformation microstructures. Additionally, voids were found from the PWR bolt and the VVER bolt had a high density of dislocations. (authors)

  7. Characterization of the system MoS{sub 2} + C, HAADF vs Tem conventional; Cracterizacion del sistema MoS{sub 2} + C, HAADF vs TEM convencional

    Energy Technology Data Exchange (ETDEWEB)

    Reza, C; Cruz, G [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Santiago, P; Rendon, L [IFUNAM, A.P. 20-364, 04510 Mexico D.F. (Mexico)

    2004-07-01

    A study is presented about the synthesis and characterization of unidimensional nano systems composed of MoS{sub 2} and C with potential use as solid lubricant. The synthesis process was developed for the mold method, via thermal decomposition, which uses a film of nano porous aluminium oxide. Such systems were characterized by two analysis methods that involve Transmission Electron Microscopy, HRTEM (Conventional TEM) and HAADF (Z Contrast). The results obtained in the structural and morphological characterization were supplemented to determine the structure type obtained in the unidimensional systems. (Author)

  8. Comprehensive analysis of TEM methods for LiFePO4/FePO4 phase mapping: spectroscopic techniques (EFTEM, STEM-EELS) and STEM diffraction techniques (ACOM-TEM)

    DEFF Research Database (Denmark)

    Mu, X.; Kobler, A.; Wang, D.

    2016-01-01

    Transmission electron microscopy (TEM) has been used intensively in investigating battery materials, e.g. to obtain phase maps of partially (dis)charged (lithium) iron phosphate (LFP/FP), which is one of the most promising cathode material for next generation lithium ion (Li-ion) batteries. Due t...

  9. Shining light on the Environmental TEM

    DEFF Research Database (Denmark)

    Wagner, Jakob Birkedal; Cavalca, Filippo; Hansen, Thomas Willum

    Yoshida et al. reported transmission electron microscopy imaging of CO molecules adsorbed on Au nanoparticles5. However, when gas is present in the microscope column the electron wave is modified due to gas-electron interactions6, 7. Several factors have to be taken into account when combining high......-energy electrons with a gaseous environment. The fast electrons are scattered both elastically and inelastically by the gas molecules resulting in distortions of the electron wave both above and below the sample, thus altering the incoming and the exit wave carrying the image information. Furthermore......, the interaction between fast electrons and gas molecules leads to ionization of the gas molecules. A full understanding of both the interaction of fast electrons with gas molecules and the effect of gas on high‐resolution imaging is therefore necessary to take the next step towards quantitative ETEM. Here...

  10. Electron holography for polymer microscopy

    International Nuclear Information System (INIS)

    Joy, D.C.

    1992-01-01

    Electron holography provides a radically new approach to the problem of imaging objects such as macromolecules, which exhibit little or no contrast when viewed in the conventional transmission electron microscope (TEM). This is overcome in electron holography by using the macromolecule as a phase object. Computer reconstruction of the hologram then allows the phase to be viewed as an image, and amplified. Holography requires a TEM with a field emission gun, and with an electro-static biprism to produce the interference pattern. The hologram requires a similar radiation dose to conventional microscopy but many different images (e.g. a through focal series) can be extracted from the same hologram. Further developments of the technique promise to combine high contrast imaging of the bulk of the macromolecule together with high spatial resolution imaging of surface detail

  11. Characterization of nanomaterials with transmission electron microscopy

    KAUST Repository

    Anjum, Dalaver H.

    2016-08-01

    The field of nanotechnology is about research and development on materials whose at least one dimension is in the range of 1 to 100 nanometers. In recent years, the research activity for developing nano-materials has grown exponentially owing to the fact that they offer better solutions to the challenges faced by various fields such as energy, food, and environment. In this paper, the importance of transmission electron microscopy (TEM) based techniques is demonstrated for investigating the properties of nano-materials. Specifically the nano-materials that are investigated in this report include gold nano-particles (Au-NPs), silver atom-clusters (Ag-ACs), tantalum single-atoms (Ta-SAs), carbon materials functionalized with iron cobalt (Fe-Co) NPs and titania (TiO2) NPs, and platinum loaded Ceria (Pt-CeO2) Nano composite. TEM techniques that are employed to investigate nano-materials include aberration corrected bright-field TEM (BF-TEM), high-angle dark-field scanning TEM (HAADF-STEM), electron energy-loss spectroscopy (EELS), and BF-TEM electron tomography (ET). With the help presented of results in this report, it is proved herein that as many TEM techniques as available in a given instrument are essential for a comprehensive nano-scale analysis of nanomaterials.

  12. Towards in-situ tem analysis of PLD Pb(Zr,Ti)O3 thin film membranes

    NARCIS (Netherlands)

    Sardan Sukas, Ö.; Berenschot, Johan W.; de Boer, Meint J.; Nguyen, Duc Minh; van Zalk, M.; Abelmann, Leon

    2011-01-01

    In this paper, a novel technique for fabricating Transmission Electron Microscopy (TEM) chips for investigating structural and piezoelectric properties of Pulse Laser Deposited (PLD) Lead Zirconium Titanate (PZT) thin films is presented. The method involves silicon-on-insulator (SOI) wafer

  13. PROPOSED ASTM METHOD FOR THE DETERMINATION OF ASBESTOS IN AIR BY TEM AND INFORMATION ON INTERFERING FIBERS

    Science.gov (United States)

    The draft of the ASTM Test Method for air entitled: "Airborne Asbestos Concentration in Ambient and Indoor Atmospheres as Determined by Transmission Electron Microscopy Direct Transfer (TEM)" (ASTM Z7077Z) is an adaptation of the International Standard, ISO 10312. It is currently...

  14. In situ transmission electron microscopy for magnetic nanostructures

    DEFF Research Database (Denmark)

    Ngo, Duc-The; Kuhn, Luise Theil

    2016-01-01

    Nanomagnetism is a subject of great interest because of both application and fundamental aspects in which understanding of the physical and electromagnetic structure of magnetic nanostructures is essential to explore the magnetic properties. Transmission electron microscopy (TEM) is a powerful tool...... that allows understanding of both physical structure and micromagnetic structure of the thin samples at nanoscale. Among TEM techniques, in situ TEM is the state-of-the-art approach for imaging such structures in dynamic experiments, reconstructing a real-time nanoscale picture of the properties......-structure correlation. This paper aims at reviewing and discussing in situ TEM magnetic imaging studies, including Lorentz microscopy and electron holography in TEM, applied to the research of magnetic nanostructures....

  15. Quantitative TEM study of the precipitation microstructure in aluminium alloy Al(MgSiCu) 6056 T6

    International Nuclear Information System (INIS)

    Delmas, F.; Casanove, M.J.; Lours, P.; Couret, A.; Coujou, A.

    2004-01-01

    The precipitate microstructure in the last-generation aluminium alloy 6056 T6 [AlMgSiCu] is investigated using three complementary techniques of transmission electron microscopy (TEM) with a special focus on the density and volume fraction of strengthening particles. High-resolution TEM allows the identification of the precipitates and the measurement of the precipitate sizes to be performed. Conventional TEM is used to evaluate the number of precipitates in the investigated area as well as their distribution in the matrix. In situ TEM straining, via the analysis of the dislocation slip traces, permits to determine precisely the thickness and the volume of the foil in the region where the precipitates are analysed. Taking into account the shape and the dimensions of precipitates with respect to the foil thickness, a novel methodology for measuring the volume density and the volume fraction of precipitates is proposed

  16. GISAXS modelling of helium-induced nano-bubble formation in tungsten and comparison with TEM

    International Nuclear Information System (INIS)

    Thompson, Matt; Sakamoto, Ryuichi; Bernard, Elodie; Kirby, Nigel; Kluth, Patrick; Riley, Daniel; Corr, Cormac

    2016-01-01

    Grazing-incidence small angle x-ray scattering (GISAXS) is a powerful non-destructive technique for the measurement of nano-bubble formation in tungsten under helium plasma exposure. Here, we present a comparative study between transmission electron microscopy (TEM) and GISAXS measurements of nano-bubble formation in tungsten exposed to helium plasma in the Large Helical Device (LHD) fusion experiment. Both techniques are in excellent agreement, suggesting that nano-bubbles range from spheroidal to ellipsoidal, displaying exponential diameter distributions with mean diameters μ=0.68 ± 0.04 nm and μ=0.6 ± 0.1 nm measured by TEM and GISAXS respectively. Depth distributions were also computed, with calculated exponential depth distributions with mean depths of 8.4 ± 0.5 nm and 9.1 ± 0.4 nm for TEM and GISAXS. In GISAXS modelling, spheroidal particles were fitted with an aspect ratio ε=0.7 ± 0.1. The GISAXS model used is described in detail. - Highlights: • GISAXS and TEM were used to measure nano-bubble formation in W exposed to He plasma in the large helical device. • Nano-bubbles had an exponential diameter distributions with averages 0.6 ± 0.1 nm and 0.68 ± 0.04 nm measured by GISAXS and TEM. • Nano-bubbles had an exponential depth distributions with average depths of 9.1 ± 0.4 nm and 8.4 ± 0.5 nm for GISAXS and TEM. • The GISAXS model used to analyse diffraction patterns is explained in detail.

  17. GISAXS modelling of helium-induced nano-bubble formation in tungsten and comparison with TEM

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Matt, E-mail: matt.a.thompson@anu.edu.au [Research School of Physics and Engineering, Australian National University, Mills Road, Acton, ACT 2601 (Australia); Sakamoto, Ryuichi [National Institute for Fusion Science, Toki, Gifu 509-5292 (Japan); Bernard, Elodie [Aix-Marseille University, Marseille 13288 (France); Kirby, Nigel [SAXS/WAXS Beamline, Australian Synchrotron, 800 Blackburn Rd, Clayton, VIC, 3168 (Australia); Kluth, Patrick [Research School of Physics and Engineering, Australian National University, Mills Road, Acton, ACT 2601 (Australia); Riley, Daniel [Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW, 2232 (Australia); Corr, Cormac [Research School of Physics and Engineering, Australian National University, Mills Road, Acton, ACT 2601 (Australia)

    2016-05-15

    Grazing-incidence small angle x-ray scattering (GISAXS) is a powerful non-destructive technique for the measurement of nano-bubble formation in tungsten under helium plasma exposure. Here, we present a comparative study between transmission electron microscopy (TEM) and GISAXS measurements of nano-bubble formation in tungsten exposed to helium plasma in the Large Helical Device (LHD) fusion experiment. Both techniques are in excellent agreement, suggesting that nano-bubbles range from spheroidal to ellipsoidal, displaying exponential diameter distributions with mean diameters μ=0.68 ± 0.04 nm and μ=0.6 ± 0.1 nm measured by TEM and GISAXS respectively. Depth distributions were also computed, with calculated exponential depth distributions with mean depths of 8.4 ± 0.5 nm and 9.1 ± 0.4 nm for TEM and GISAXS. In GISAXS modelling, spheroidal particles were fitted with an aspect ratio ε=0.7 ± 0.1. The GISAXS model used is described in detail. - Highlights: • GISAXS and TEM were used to measure nano-bubble formation in W exposed to He plasma in the large helical device. • Nano-bubbles had an exponential diameter distributions with averages 0.6 ± 0.1 nm and 0.68 ± 0.04 nm measured by GISAXS and TEM. • Nano-bubbles had an exponential depth distributions with average depths of 9.1 ± 0.4 nm and 8.4 ± 0.5 nm for GISAXS and TEM. • The GISAXS model used to analyse diffraction patterns is explained in detail.

  18. Aberration-corrected STEM/TEM imaging at 15 kV

    International Nuclear Information System (INIS)

    Sasaki, Takeo; Sawada, Hidetaka; Hosokawa, Fumio; Sato, Yuta; Suenaga, Kazu

    2014-01-01

    The performance of aberration-corrected (scanning) transmission electron microscopy (S/TEM) at an accelerating voltage of 15 kV was evaluated in a low-voltage microscope equipped with a cold-field emission gun and a higher-order aberration corrector. Aberrations up to the fifth order were corrected by the aberration measurement and auto-correction system using the diffractogram tableau method in TEM and Ronchigram analysis in STEM. TEM observation of nanometer-sized particles demonstrated that aberrations up to an angle of 50 mrad were compensated. A TEM image of Si[110] exhibited lattice fringes with a spacing of 0.192 nm, and the power spectrum of the image showed spots corresponding to distances of 0.111 nm. An annular dark-field STEM image of Si[110] showed lattice fringes of (111) and (22¯0) planes corresponding to lattice distances of 0.314 nm and 0.192 nm, respectively. At an accelerating voltage of 15 kV, the developed low-voltage microscope achieved atomic-resolution imaging with a small chromatic aberration and a large uniform phase. - Highlights: • Aberration-corrected STEM/TEM imaging at 15 kV demonstrated lattice fringes of Si[110] single crystal with a spacing of 0.192 nm. • To achieve this performance at a lower accelerating voltage, uniform phase area over 50 mrad is mandatory in Ronchigram and Diffractogram tableau. • This means a higher-order aberration of six-fold astigmatism should be compensated. • In addition, decreasing the effect of chromatic aberration plays an important role for improving the performance of linear scattering component at 15 kV TEM

  19. Quantitative evaluation of temporal partial coherence using 3D Fourier transforms of through-focus TEM images

    International Nuclear Information System (INIS)

    Kimoto, Koji; Sawada, Hidetaka; Sasaki, Takeo; Sato, Yuta; Nagai, Takuro; Ohwada, Megumi; Suenaga, Kazu; Ishizuka, Kazuo

    2013-01-01

    We evaluate the temporal partial coherence of transmission electron microscopy (TEM) using the three-dimensional (3D) Fourier transform (FT) of through-focus images. Young's fringe method often indicates the unexpected high-frequency information due to non-linear imaging terms. We have already used the 3D FT of axial (non-tilted) through-focus images to reduce the effect of non-linear terms on the linear imaging term, and demonstrated the improvement of monochromated lower-voltage TEM performance [Kimoto et al., Ultramicroscopy 121 (2012) 31–39]. Here we apply the 3D FT method with intentionally tilted incidence to normalize various factors associated with a TEM specimen and an imaging device. The temporal partial coherence of two microscopes operated at 30, 60 and 80 kV is evaluated. Our method is applicable to such cases where the non-linear terms become more significant in lower acceleration voltage or aberration-corrected high spatial resolution TEM. - Highlights: • We assess the temporal partial coherence of TEM using a 3-dimensional (3D) Fourier transform (FT) of through-focus images. • We apply the 3D FT method with intentionally tilted incidence to normalize various factors associated with a TEM specimen and an imaging device. • The spatial frequency at which information transfer decreases to 1/e 2 (13.5%) is determined for two lower-voltage TEM systems

  20. cisTEM, user-friendly software for single-particle image processing

    Science.gov (United States)

    2018-01-01

    We have developed new open-source software called cisTEM (computational imaging system for transmission electron microscopy) for the processing of data for high-resolution electron cryo-microscopy and single-particle averaging. cisTEM features a graphical user interface that is used to submit jobs, monitor their progress, and display results. It implements a full processing pipeline including movie processing, image defocus determination, automatic particle picking, 2D classification, ab-initio 3D map generation from random parameters, 3D classification, and high-resolution refinement and reconstruction. Some of these steps implement newly-developed algorithms; others were adapted from previously published algorithms. The software is optimized to enable processing of typical datasets (2000 micrographs, 200 k – 300 k particles) on a high-end, CPU-based workstation in half a day or less, comparable to GPU-accelerated processing. Jobs can also be scheduled on large computer clusters using flexible run profiles that can be adapted for most computing environments. cisTEM is available for download from cistem.org. PMID:29513216

  1. cisTEM, user-friendly software for single-particle image processing.

    Science.gov (United States)

    Grant, Timothy; Rohou, Alexis; Grigorieff, Nikolaus

    2018-03-07

    We have developed new open-source software called cis TEM (computational imaging system for transmission electron microscopy) for the processing of data for high-resolution electron cryo-microscopy and single-particle averaging. cis TEM features a graphical user interface that is used to submit jobs, monitor their progress, and display results. It implements a full processing pipeline including movie processing, image defocus determination, automatic particle picking, 2D classification, ab-initio 3D map generation from random parameters, 3D classification, and high-resolution refinement and reconstruction. Some of these steps implement newly-developed algorithms; others were adapted from previously published algorithms. The software is optimized to enable processing of typical datasets (2000 micrographs, 200 k - 300 k particles) on a high-end, CPU-based workstation in half a day or less, comparable to GPU-accelerated processing. Jobs can also be scheduled on large computer clusters using flexible run profiles that can be adapted for most computing environments. cis TEM is available for download from cistem.org. © 2018, Grant et al.

  2. Correlative Light- and Electron Microscopy Using Quantum Dot Nanoparticles.

    Science.gov (United States)

    Killingsworth, Murray C; Bobryshev, Yuri V

    2016-08-07

    A method is described whereby quantum dot (QD) nanoparticles can be used for correlative immunocytochemical studies of human pathology tissue using widefield fluorescence light microscopy and transmission electron microscopy (TEM). To demonstrate the protocol we have immunolabeled ultrathin epoxy sections of human somatostatinoma tumor using a primary antibody to somatostatin, followed by a biotinylated secondary antibody and visualization with streptavidin conjugated 585 nm cadmium-selenium (CdSe) quantum dots (QDs). The sections are mounted on a TEM specimen grid then placed on a glass slide for observation by widefield fluorescence light microscopy. Light microscopy reveals 585 nm QD labeling as bright orange fluorescence forming a granular pattern within the tumor cell cytoplasm. At low to mid-range magnification by light microscopy the labeling pattern can be easily recognized and the level of non-specific or background labeling assessed. This is a critical step for subsequent interpretation of the immunolabeling pattern by TEM and evaluation of the morphological context. The same section is then blotted dry and viewed by TEM. QD probes are seen to be attached to amorphous material contained in individual secretory granules. Images are acquired from the same region of interest (ROI) seen by light microscopy for correlative analysis. Corresponding images from each modality may then be blended to overlay fluorescence data on TEM ultrastructure of the corresponding region.

  3. Experimental study on propagation properties of large size TEM antennas

    International Nuclear Information System (INIS)

    Zhang Guowei; Wang Haiyang; Chen Weiqing; Wang Wei; Zhu Xiangqin; Xie Linshen

    2014-01-01

    The propagation properties of large size TEM antennas were studied by experiment. The size of the TEM antennas is 60 m × 20 m × 10 m and the character Impedance is 120 Ω. A kind of dielectric foil switch is designed compactly with TEM antennas which can generate double exponential waveform with altitude of 10 kV and rise time of l.2 ns. The radiated field distribution was measured. The relationship between rise time/altitude and distance were provided, and the propagation properties of large size TEM antennas were summarized. (authors)

  4. A flexible multi-stimuli in situ (S)TEM: Concept, optical performance, and outlook

    International Nuclear Information System (INIS)

    Börrnert, Felix; Müller, Heiko; Riedel, Thomas; Linck, Martin; Kirkland, Angus I.; Haider, Max.; Büchner, Bernd; Lichte, Hannes

    2015-01-01

    The progress in (scanning) transmission electron microscopy development had led to an unprecedented knowledge of the microscopic structure of functional materials at the atomic level. Additionally, although not widely used yet, electron holography is capable to map the electric and magnetic potential distributions at the sub-nanometer scale. Nevertheless, in situ studies inside a (scanning) transmission electron microscope ((S)TEM) are extremely challenging because of the much restricted size and accessibility of the sample space. Here, we introduce a concept for a dedicated in situ (S)TEM with a large sample chamber for flexible multi-stimuli experimental setups and report about the electron optical performance of the instrument. We demonstrate a maximum resolving power of about 1 nm in conventional imaging mode and substantially better than 5 nm in scanning mode while providing an effectively usable “pole piece gap” of 70 mm. - Highlights: • A concept for a (S)TEM with a large sample chamber is outlined. • An actual microscope is modified and has now a 70 mm high sample space. • The resolving power is about 1 nm in TEM and better than 5 nm in STEM mode. • Possible dedicated in situ microscopes with present technology are discussed

  5. Soft nanomaterials analysed by in situ liquid TEM: Towards high resolution characterisation of nanoparticles in motion

    Directory of Open Access Journals (Sweden)

    Joseph P. Patterson

    2015-12-01

    Full Text Available In this article we present in situ transmission electron microscopy (TEM of soft, synthetic nanoparticles with a comparative analysis using conventional TEM methods. This comparison is made with the simple aim of describing what is an unprecedented example of in situ imaging by TEM. However, we contend the technique will quickly become essential in the characterisation of analogous systems, especially where dynamics are of interest in the solvated state. In this case, particles were studied which were obtained from the direct polymerisation of an oxaliplatin analogue, designed for an ongoing programme in novel chemotherapeutic delivery systems. The resulting nanoparticles provided sufficient contrast for facile imaging in situ, and point towards key design parameters that enable this new characterisation approach for organic nanomaterials. We describe the preparation of the synthetic nanoparticles together with their characterisation in liquid water. Finally, we provide a future perspective of this technique for the analysis of soft and dynamic nanomaterials and discussion the progress which needs to be made in order to bring in situ liquid TEM to its full potential.

  6. A flexible multi-stimuli in situ (S)TEM: Concept, optical performance, and outlook

    Energy Technology Data Exchange (ETDEWEB)

    Börrnert, Felix, E-mail: felix.boerrnert@triebenberg.de [Speziallabor Triebenberg, Technische Universität Dresden, 01062 Dresden (Germany); IFW Dresden, PF 27 01 16, 01171 Dresden (Germany); Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Müller, Heiko; Riedel, Thomas; Linck, Martin [CEOS GmbH, Englerstraße 28, 69126 Heidelberg (Germany); Kirkland, Angus I. [Department of Materials, University of Oxford, Parks Road, Oxford OX1 3PH (United Kingdom); Haider, Max. [CEOS GmbH, Englerstraße 28, 69126 Heidelberg (Germany); Büchner, Bernd [IFW Dresden, PF 27 01 16, 01171 Dresden (Germany); Lichte, Hannes [Speziallabor Triebenberg, Technische Universität Dresden, 01062 Dresden (Germany)

    2015-04-15

    The progress in (scanning) transmission electron microscopy development had led to an unprecedented knowledge of the microscopic structure of functional materials at the atomic level. Additionally, although not widely used yet, electron holography is capable to map the electric and magnetic potential distributions at the sub-nanometer scale. Nevertheless, in situ studies inside a (scanning) transmission electron microscope ((S)TEM) are extremely challenging because of the much restricted size and accessibility of the sample space. Here, we introduce a concept for a dedicated in situ (S)TEM with a large sample chamber for flexible multi-stimuli experimental setups and report about the electron optical performance of the instrument. We demonstrate a maximum resolving power of about 1 nm in conventional imaging mode and substantially better than 5 nm in scanning mode while providing an effectively usable “pole piece gap” of 70 mm. - Highlights: • A concept for a (S)TEM with a large sample chamber is outlined. • An actual microscope is modified and has now a 70 mm high sample space. • The resolving power is about 1 nm in TEM and better than 5 nm in STEM mode. • Possible dedicated in situ microscopes with present technology are discussed.

  7. TEM and ellipsometry studies of nanolaminate oxide films prepared using atomic layer deposition

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, D.R.G. [Materials and Engineering Science, ANSTO, PMB 1, Menai, NSW 2234 (Australia)]. E-mail: drm@ansto.gov.au; Attard, D.J. [Materials and Engineering Science, ANSTO, PMB 1, Menai, NSW 2234 (Australia); Finnie, K.S. [Materials and Engineering Science, ANSTO, PMB 1, Menai, NSW 2234 (Australia); Triani, G. [Materials and Engineering Science, ANSTO, PMB 1, Menai, NSW 2234 (Australia); Barbe, C.J. [Materials and Engineering Science, ANSTO, PMB 1, Menai, NSW 2234 (Australia); Depagne, C. [Materials and Engineering Science, ANSTO, PMB 1, Menai, NSW 2234 (Australia); Bartlett, J.R. [Materials and Engineering Science, ANSTO, PMB 1, Menai, NSW 2234 (Australia)

    2005-04-30

    Nanolaminate oxide layers consisting of TiO{sub 2} and Al{sub 2}O{sub 3} have been deposited on silicon using atomic layer deposition (ALD). Characterisation of these films has been achieved by use of a range of modern transmission electron microscopy (TEM)-based techniques, including plasmon loss imaging, energy filtered imaging and scanning TEM (STEM) X-ray line profiling. These have shown that the target thickness of the individual layers in the nanolaminate structures (20 nm) has been met with a high degree of accuracy, that the layers are extremely flat and parallel and that the interfaces between the layers are compositionally abrupt. Localised crystallisation within the stacks, and responses to electron beam irradiation point to the presence of a stress gradient within the layers. The performance of ellipsometry in characterising multilayer stacks has been benchmarked against the TEM measurements. Errors in determination of individual layer thicknesses were found to increase with growing stack size, as expected given the increasing number of interfaces incorporated in each model. The most sophisticated model gave maximum deviations of {+-}4 nm from the TEM determined values for the 5- and 10-layer stacks.

  8. Processing scarce biological samples for light and transmission electron microscopy

    Directory of Open Access Journals (Sweden)

    P Taupin

    2008-06-01

    Full Text Available Light microscopy (LM and transmission electron microscopy (TEM aim at understanding the relationship structure-function. With advances in biology, isolation and purification of scarce populations of cells or subcellular structures may not lead to enough biological material, for processing for LM and TEM. A protocol for preparation of scarce biological samples is presented. It is based on pre-embedding the biological samples, suspensions or pellets, in bovine serum albumin (BSA and bis-acrylamide (BA, cross-linked and polymerized. This preparation provides a simple and reproducible technique to process biological materials, present in limited quantities that can not be amplified, for light and transmission electron microscopy.

  9. Oil refinery dusts: morphological and size analysis by TEM.

    Science.gov (United States)

    Sielicki, Przemysław; Janik, Helena; Guzman, Agnieszka; Broniszewski, Mieczysław; Namieśnik, Jacek

    2011-03-01

    The objectives of this work were to develop a means of sampling atmospheric dusts on the premises of an oil refinery for electron microscopic study to carry out preliminary morphological analyses and to compare these dusts with those collected at sites beyond the refinery limits. Carbon and collodion membranes were used as a support for collection of dust particles straight on transmission electron microscopy (TEM) grids. Micrographs of the dust particles were taken at magnifications from ×4,000 to ×80,000 with a Tesla BS500 transmission electron microscope. Four parameters were defined on the basis of the micrographs: surface area, Feret diameter, circumference, and shape coefficient. The micrographs and literature data were used to classify the atmospheric dusts into six groups: particles with an irregular shape and rounded edges; particles with an irregular shape and sharp edges; soot and its aggregates; spherical particles; singly occurring, ultrafine dust particles; and particles not allocated to any of the previous five groups. The types of dusts found in all the samples were similar, although differences did exist between the various morphological parameters. Dust particles with the largest Feret diameter were present in sample 3 (mean, 0.739 μm)-these were collected near the refinery's effluent treatment plant. The particles with the smallest diameter were found in the sample that had been intended to be a reference sample for the remaining results (mean, 0.326 μm). The dust particles collected in the refinery had larger mean Feret diameters, even 100% larger, than those collected beyond it. Particles with diameters from 0.1 to 0.2 μm made up the most numerous group in all the samples collected in the refinery.

  10. Oil refinery dusts: morphological and size analysis by TEM

    Energy Technology Data Exchange (ETDEWEB)

    Sielicki, Przemyslaw; Janik, Helena; Guzman, Agnieszka [Gdansk University of Technology, Department of Polymer Technology, Chemical Faculty, Gdansk (Poland); Broniszewski, Mieczyslaw [Environmental Protection Office, Lotos Group, Gdansk (Poland); Namiesnik, Jacek [Gdansk University of Technology, Department of Analytical Chemistry, Chemical Faculty, Gdansk (Poland)

    2011-03-15

    The objectives of this work were to develop a means of sampling atmospheric dusts on the premises of an oil refinery for electron microscopic study to carry out preliminary morphological analyses and to compare these dusts with those collected at sites beyond the refinery limits. Carbon and collodion membranes were used as a support for collection of dust particles straight on transmission electron microscopy (TEM) grids. Micrographs of the dust particles were taken at magnifications from x 4,000 to x 80,000 with a Tesla BS500 transmission electron microscope. Four parameters were defined on the basis of the micrographs: surface area, Feret diameter, circumference, and shape coefficient. The micrographs and literature data were used to classify the atmospheric dusts into six groups: particles with an irregular shape and rounded edges; particles with an irregular shape and sharp edges; soot and its aggregates; spherical particles; singly occurring, ultrafine dust particles; and particles not allocated to any of the previous five groups. The types of dusts found in all the samples were similar, although differences did exist between the various morphological parameters. Dust particles with the largest Feret diameter were present in sample 3 (mean, 0.739 {mu}m) - these were collected near the refinery's effluent treatment plant. The particles with the smallest diameter were found in the sample that had been intended to be a reference sample for the remaining results (mean, 0.326 {mu}m). The dust particles collected in the refinery had larger mean Feret diameters, even 100% larger, than those collected beyond it. Particles with diameters from 0.1 to 0.2 {mu}m made up the most numerous group in all the samples collected in the refinery. (orig.)

  11. In situ TEM study of the coarsening of carbon black supported Pt nanoparticles in hydrogen

    DEFF Research Database (Denmark)

    Simonsen, Søren Bredmose; Wang, Yan; Jensen, Jens Oluf

    2017-01-01

    The control of sizes and shapes of nanostructures is of tremendous importance for the catalytic activity in electrochemistry and in catalysis more generally. However, due to relatively large surface free energies, nanostructures often sinter to form coarser and more stable structures that may...... not have the intended physicochemical properties. Pt is known to be a very active catalyst in several chemical reactions and for example as carbon supported nanoparticles in fuel cells. The presentation focusses on coarsening mechanisms of Pt nanoparticles supported on carbon black during exposure...... to hydrogen. By means of in situ transmission electron microscopy (TEM), Pt nanoparticle coarsening was monitored in 6 mbar 20 % H2/Ar while ramping up the temperature to ca. 900 °C. Time-resolved TEM images directly reveal that separated ca. 3 nm sized Pt nanoparticles in the pure hydrogen environment...

  12. TEM study of the ion beam induced damage during 14 kev P+ implantation in silicon

    International Nuclear Information System (INIS)

    Rubanov, S.; Tamanyan, G.; Hudson, F.; Jamieson, D.N.; McCallum, J.C.; Prawer, S.

    2005-01-01

    The proposed silicon-based quantum computer architecture comprises an array of phosphorus donor atoms (qubits) positioned with nanometre accuracy beneath the surface of a semiconductor host, using a single ion implantation technique. The average depth of the implanted ions (the projected range R p ), lateral range R p 1, and the distribution of ions about that depth can be approximated as two-dimensional Gaussian with standard deviation ΔR p and ΔR p 1 (lateral straggle). Using transmission electron microscopy (TEM) we studied ion beam induced damage after 14 keV P + implantation in Si. The TEM images allowed us to compare the depth of the amorphous cluster formation to R p , R p 1, ΔR p 1 calculated from SRIM and hence determine evidence for the limitation on the accuracy of the position of the implanted ions imposed by straggling. (author). 4 refs., 3 figs

  13. TEM microstructural analysis of creep deformed CM186LC single crystal Ni-base superalloy

    Energy Technology Data Exchange (ETDEWEB)

    Dubiel, B.; Czyrska-Filemonowicz, A. [AGH Univ. of Science and Technology, Krakow (Poland); Blackler, M. [Howmet Ltd., Exeter (United Kingdom); Barnard, P.M. [ALSTOM Power Turbo-Systems Technology Centre, Rugby (United Kingdom)

    2006-07-01

    The nickel based single crystal superalloy CM186LC was extensively investigated as a potential low cost material for industrial gas turbine vanes within the COST522 programme. The alloy exhibits inhomogeneous structure consisting of dendritic regions and eutectic colonies. In the present work attention is focused on microstructural changes observed in single crystal CM186LC following creep deformation at 750 C. Creep tests were conducted at 750 C with an applied stress of 560 or 675 MPa for up to 11440 hours. The microstructure o ruptured and terminated specimens was investigated by scanning (SEM) and transmission (TEM) electron microscopy. TEM analysis revealed the microstructural changes in the CM186LC at primary and secondary creep as well as after creep rupture. (orig.)

  14. Focus-variation image reconstruction in field-emission TEM

    NARCIS (Netherlands)

    Coene, W.M.J.; Janssen, A.J.E.M.; Op de Beeck, M.; Van Dyck, D.; Van Zwet, E.J.; Zandbergen, H.W.; Bailey, G.W.; Rieder, C.L.

    1993-01-01

    The use of a field emission gun (FEG) in high resolution TEM (HRTEM) improves the information limit much below the point resolution. In the area between point and information resolution of the FEG-TEM, image interpretation is complicated by the lens aberrations and focus effects. Different

  15. New constraints on deformation processes in serpentinite from sub-micron Raman Spectroscopy and TEM

    Science.gov (United States)

    Smith, S. A. F.; Tarling, M.; Rooney, J. S.; Gordon, K. C.; Viti, C.

    2017-12-01

    Extensive work has been performed to characterize the mineralogical and mechanical properties of the various serpentine minerals (i.e. antigorite, lizardite, chrysotile, polyhedral and polygonal serpentine). However, correct identification of serpentine minerals is often difficult or impossible using conventional analytical techniques such as optical- and SEM-based microscopy, X-ray diffraction and infrared spectroscopy. Transmission Electron Microscopy (TEM) is the best analytical technique to identify the serpentine minerals, but TEM requires complex sample preparation and typically results in very small analysis areas. Sub-micron confocal Raman spectroscopy mapping of polished thin sections provides a quick and relatively inexpensive way of unambiguously distinguishing the main serpentine minerals within their in-situ microstructural context. The combination of high spatial resolution (with a diffraction-limited system, 366 nm), large-area coverage (up to hundreds of microns in each dimension) and ability to map directly on thin sections allows intricate fault rock textures to be imaged at a sample-scale, which can then form the target of more focused TEM work. The potential of sub-micron Raman Spectroscopy + TEM is illustrated by examining sub-micron-scale mineral intergrowths and deformation textures in scaly serpentinites (e.g. dissolution seams, mineral growth in pressure shadows), serpentinite crack-seal veins and polished fault slip surfaces from a serpentinite-bearing mélange in New Zealand. The microstructural information provided by these techniques has yielded new insights into coseismic dehydration and amorphization processes and the interplay between creep and localised rupture in serpentinite shear zones.

  16. Mechanical Conversion for High-Throughput TEM Sample Preparation

    International Nuclear Information System (INIS)

    Kendrick, Anthony B; Moore, Thomas M; Zaykova-Feldman, Lyudmila

    2006-01-01

    This paper presents a novel method of direct mechanical conversion from lift-out sample to TEM sample holder. The lift-out sample is prepared in the FIB using the in-situ liftout Total Release TM method. The mechanical conversion is conducted using a mechanical press and one of a variety of TEM coupons, including coupons for both top-side and back-side thinning. The press joins a probe tip point with attached TEM sample to the sample coupon and separates the complete assembly as a 3mm diameter TEM grid, compatible with commercially available TEM sample holder rods. This mechanical conversion process lends itself well to the high through-put requirements of in-line process control and to materials characterization labs where instrument utilization and sample security are critically important

  17. Characterization of isolated polyamide thin films of RO and NF membranes using novel TEM techniques

    KAUST Repository

    Pacheco, Federico A.; Pinnau, Ingo; Reinhard, Martin; Leckie, James O.

    2010-01-01

    Achieving a better understanding of transport and rejection mechanisms in RO and NF membranes requires more detailed information of the nanostructure of polyamide thin films. This study reports on two novel transmission electron microscopy (TEM) techniques for characterizing polyamide nanostructure. The first technique produces cross-sectional images of isolated polyamide thin films by removing the polysulfone support from regular TEM cross-sections. In the second technique called " projected area" TEM (PA-TEM), isolated polyamide thin films are placed with their surface perpendicular to the electron beam. The resulting images capture the thickness, morphology and mass density of the entire thin film. In combination, these new techniques provide information on polyamide nanostructure that is not evident using conventional methods. For the commercial RO membrane ESPA3, the cross-sectional view of the isolated polyamide thin film shows a 30-60. nm thick base of nodular polyamide (presumably the separation barrier) that forms a relatively smooth interface with the polysulfone support. Above this, a more open structure of loose polyamide extends outward giving rise to the ridge-and-valley surface structure. In PA-TEM images, the ridges and valleys correspond to the dark and bright regions, respectively; the polyamide nodular base appears as round features forming an irregular honeycomb pattern throughout the images. Membrane cross-sections were prepared with a simple resin embedding protocol using the acrylic resin LR White. The protocol did not require dehydration steps, and was applicable to both dry and wet membrane samples. Artifacts that may be produced during sample preparation were also documented. © 2010 Elsevier B.V.

  18. Characterization of isolated polyamide thin films of RO and NF membranes using novel TEM techniques

    KAUST Repository

    Pacheco, Federico A.

    2010-08-15

    Achieving a better understanding of transport and rejection mechanisms in RO and NF membranes requires more detailed information of the nanostructure of polyamide thin films. This study reports on two novel transmission electron microscopy (TEM) techniques for characterizing polyamide nanostructure. The first technique produces cross-sectional images of isolated polyamide thin films by removing the polysulfone support from regular TEM cross-sections. In the second technique called " projected area" TEM (PA-TEM), isolated polyamide thin films are placed with their surface perpendicular to the electron beam. The resulting images capture the thickness, morphology and mass density of the entire thin film. In combination, these new techniques provide information on polyamide nanostructure that is not evident using conventional methods. For the commercial RO membrane ESPA3, the cross-sectional view of the isolated polyamide thin film shows a 30-60. nm thick base of nodular polyamide (presumably the separation barrier) that forms a relatively smooth interface with the polysulfone support. Above this, a more open structure of loose polyamide extends outward giving rise to the ridge-and-valley surface structure. In PA-TEM images, the ridges and valleys correspond to the dark and bright regions, respectively; the polyamide nodular base appears as round features forming an irregular honeycomb pattern throughout the images. Membrane cross-sections were prepared with a simple resin embedding protocol using the acrylic resin LR White. The protocol did not require dehydration steps, and was applicable to both dry and wet membrane samples. Artifacts that may be produced during sample preparation were also documented. © 2010 Elsevier B.V.

  19. TOPICAL REVIEW: Present status and future prospects of spherical aberration corrected TEM/STEM for study of nanomaterials

    Directory of Open Access Journals (Sweden)

    Nobuo Tanaka

    2008-01-01

    Full Text Available The present status of Cs-corrected TEM/STEM is described from the viewpoint of the observation of nanomaterials. Characteristic features in TEM and STEM are explained using the experimental data obtained by our group and other research groups. Cs correction up to the 3rd-order aberration of an objective lens has already been established and research interest is focused on correcting the 5th-order spherical aberration and the chromatic aberration in combination with the development of a monochromator below an electron gun for smaller point-to-point resolution in optics. Another fundamental area of interest is the limitation of TEM and STEM resolution from the viewpoint of the scattering of electrons in crystals. The minimum size of the exit-wave function below samples undergoing TEM imaging is determined from the calculation of scattering around related atomic columns in the crystals. STEM does not have this limitation because the resolution is, in principle, determined by the probe size. One of the future prospects of Cs-corrected TEM/STEM is the possibility of extending the space around the sample holder by correcting the chromatic and spherical aberrations. This wider space will contribute to the ease of performing in situ experiments and various combinations of TEM and other analysis methods. High-resolution, in situ dynamic and 3D observations/analysis are the most important keywords in the next decade of high-resolution electron microscopy.

  20. TEM investigation of discommensurations in a Bi-Sr-Ca-Cu-O superconductor

    International Nuclear Information System (INIS)

    El boussiri, K.; Rais, T.; Schneck, J.; Toledano, J.C.; Morin, D.

    1997-01-01

    We were able to observe, by transmission electron microscopy (TEM), a certain type ot defects in the superconducting bismuth cuprates. High-resolution evidence for the translation slip across a wall is obtained in this material. A consistent relationship is established between the observed characteristics of the walls in this family: number of walls merging at a node, average distance between discommensurations, value of the modulation wavenumber. We show that a wide range of ''latent'' commensurate periods ''4b'', determine the characteristics of the walls. (orig.)

  1. Fourier-space TEM reconstructions with symmetry adapted functions for all rotational point groups.

    Science.gov (United States)

    Trapani, Stefano; Navaza, Jorge

    2013-05-01

    A general-purpose and simple expression for the coefficients of symmetry adapted functions referred to conveniently oriented symmetry axes is given for all rotational point groups. The expression involves the computation of reduced Wigner-matrix elements corresponding to an angle specific to each group and has the computational advantage of leading to Fourier-space TEM (transmission electron microscopy) reconstruction procedures involving only real valued unknowns. Using this expression, a protocol for ab initio view and center assignment and reconstruction so far used for icosahedral particles has been tested with experimental data in other point groups. Copyright © 2013 Elsevier Inc. All rights reserved.

  2. In situ TEM observation of microcrack nucleation and propagation in pure tin solder

    International Nuclear Information System (INIS)

    Ding Ying; Wang Chunqing; Li, Mingyu; Wang Weiqiang

    2006-01-01

    Microcrack nucleation and propagation behavior in pure tin solder was investigated by using transmission electron microscopy (TEM) through in situ tensile test. Observation results showed that fracture process was completed in this visco-plastic material by connecting discontinuous cracks or voids. Depending on remarkable vacancy diffusion ability, microvoids were nucleated and developed in the dislocation free zone (DFZ) or super thinned area ahead of crack tip under local high stress concentration. The cracks were linked with each other by mutual dislocation emission which expedites the propagation of crack tips effectively

  3. TEM characterization of Al-C-Cu-Al2O3 composites produced by mechanical milling

    International Nuclear Information System (INIS)

    Santos-Beltran, A.; Gallegos-Orozco, V.; Estrada-Guel, I.; Bejar-Gomez, L.; Espinosa-Magana, F.; Miki-Yoshida, M.; Martinez-Sanchez, R.

    2007-01-01

    Novel Al-based composites (Al-C-Cu-Al 2 O 3 ) obtained by mechanical milling (MM), were characterized by transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS). Analyses of composites were carried out in both, the as-milled and the as-sintered conditions. C nanoparticles were found in the as-milled condition and Al 2 O 3 nanofibers were found in as-sintered products, as determined by EELS. C and Cu react with Al to crystallize in Al 3 C 4 and Al 2 Cu structures, respectively

  4. In-situ TEM study of dislocation patterning during deformation in single crystal aluminum

    International Nuclear Information System (INIS)

    Landau, P; Shneck, R Z; Makov, G; Venkert, A

    2010-01-01

    The evolution of dislocation patterns in single crystal aluminum was examined using transmission electron microscopy (TEM). In-situ tensile tests of single crystals were carried out in a manner that activated double slip. Cross slip of dislocations, which is prominent in all stages of work hardening, plays an important role in dislocation motion and microstructural evolution. In spite of the limitations of in-situ straining to represent bulk phenomena, due to surface effects and the thickness of the samples, it is shown that experiments on prestrained samples can represent the early stages of deformation. Transition between stage I and stage II of work hardening and evolution during stage III were observed.

  5. Nanoprecipitates in single-crystal molybdenum-alloy nanopillars detected by TEM and atom probe tomography

    International Nuclear Information System (INIS)

    Oveisi, Emad; Bártová, Barbora; Gerstl, Stephan; Zimmermann, Julien; Marichal, Cécile; Van Swygenhoven, Helena; Hébert, Cécile

    2013-01-01

    Transmission electron microscopy (TEM) supported by various chemical analyses techniques as well as atom probe tomography is applied to characterize newly identified nanosized precipitates in Mo-alloy nanopillars that were prepared by directional solidification. It is shown that the α-Mo matrix contains Al-enriched face-centred cubic precipitates which have a 4.12 Å lattice parameter, and exhibit a Kurdjumov–Sachs crystallographic orientation relationship with the matrix. Such precipitates could be responsible for the unusual behaviour of the pillars during compression tests

  6. TEM study of microstructure in explosive welded joints between Zircaloy-4 and stainless steel

    International Nuclear Information System (INIS)

    Zhou Hairong; Zhou Bangxin

    1996-10-01

    The microstructure of explosive welded joints between Zircaloy-4 and 18/8 stainless steel has been investigated by transmission electron microscopy (TEM). The metallurgical bonding was achieved by combining effect of diffusion and local melting when the explosive parameters were selected correctly. The molten region which consists of amorphous and crystalline with hexagonal crystal structure is hard and brittle. But the welded joints can be pulled, bent and cold rolled without cracks formed on the bonding layer, so as the molten regions are small and distributed as isolated islands. (6 refs., 6 figs., 1 tab.)

  7. Characterization of the system MoS2 + C, HAADF vs Tem conventional

    International Nuclear Information System (INIS)

    Reza, C.; Cruz, G.; Santiago, P.; Rendon, L.

    2004-01-01

    A study is presented about the synthesis and characterization of unidimensional nano systems composed of MoS 2 and C with potential use as solid lubricant. The synthesis process was developed for the mold method, via thermal decomposition, which uses a film of nano porous aluminium oxide. Such systems were characterized by two analysis methods that involve Transmission Electron Microscopy, HRTEM (Conventional TEM) and HAADF (Z Contrast). The results obtained in the structural and morphological characterization were supplemented to determine the structure type obtained in the unidimensional systems. (Author)

  8. Novel sample preparation for operando TEM of catalysts

    International Nuclear Information System (INIS)

    Miller, Benjamin K.; Barker, Trevor M.; Crozier, Peter A.

    2015-01-01

    A new TEM sample preparation method is developed to facilitate operando TEM of gas phase catalysis. A porous Pyrex-fiber pellet TEM sample was produced, allowing a comparatively large amount of catalyst to be loaded into a standard Gatan furnace-type tantalum heating holder. The increased amount of catalyst present inside the environmental TEM allows quantitative determination of the gas phase products of a catalytic reaction performed in-situ at elevated temperatures. The product gas concentration was monitored using both electron energy loss spectroscopy (EELS) and residual gas analysis (RGA). Imaging of catalyst particles dispersed over the pellet at atomic resolution is challenging, due to charging of the insulating glass fibers. To overcome this limitation, a metal grid is placed into the holder in addition to the pellet, allowing catalyst particles dispersed over the grid to be imaged, while particles in the pellet, which are assumed to experience identical conditions, contribute to the overall catalytic conversion inside the environmental TEM cell. The gas within the cell is determined to be well-mixed, making this assumption reasonable. - Highlights: • High in-situ conversion of CO to CO 2 achieved by a novel TEM sample preparation method. • A 3 mm fiber pellet increases the TEM sample surface area by 50×. • Operando atomic resolution is maintained by also including a 3 mm grid in the sample. • Evidence for a well-mixed gas composition inside the ETEM cell is given

  9. Transmission electron microscopy and diffractometry of materials

    CERN Document Server

    Fultz, Brent

    2001-01-01

    This book teaches graduate students the concepts of trans- mission electron microscopy (TEM) and x-ray diffractometry (XRD) that are important for the characterization of materi- als. It emphasizes themes common to both techniques, such as scattering from atoms and the formation and analysis of dif- fraction patterns. It also describes unique aspects of each technique, especially imaging and spectroscopy in the TEM. The textbook thoroughly develops both introductory and ad- vanced-level material, using over 400 accompanying illustra- tions. Problems are provided at the end of each chapter to reinforce key concepts. Simple citatioins of rules are avoi- ded as much as possible, and both practical and theoretical issues are explained in detail. The book can be used as both an introductory and advanced-level graduate text since sec- tions/chapters are sorted according to difficulty and grou- ped for use in quarter and semester courses on TEM and XRD.

  10. Transmission Electron Microscopy for Wood and Fiber Analysis − A Review

    Directory of Open Access Journals (Sweden)

    Mehedi Reza

    2015-07-01

    Full Text Available This review describes use of transmission electron microscopy (TEM in wood and fiber analysis. Analytical techniques and sample preparation methods are used to localize substructures of the cell wall polymers and are discussed in this review. The ultrastructural features of the wood cell walls, the structures formed by microfibrils, and the distribution of cell wall polymers, as revealed by TEM, are covered. Research investigating the distribution of lignin in tension and compression woods using TEM is reviewed. Different kinds of wood biodegrading enzymes localized using TEM are mentioned. Additional features of TEM, i.e., 3D imaging, analytical TEM, and electron diffraction are discussed. Lastly, a comparison between TEM and other imaging techniques used for wood and fiber research are made. Thus, this review provides insight into the contribution of TEM in wood research since its invention and demonstrates how to use it more effectively in the future.

  11. Heavy-ion microscopy

    International Nuclear Information System (INIS)

    Kraft, G.; Yang, T.C.H.; Richards, T.; Tobias, C.A.

    1980-01-01

    This chapter briefly describes the techniques of optical microscopy, scanning and transmission electron microscopy, soft x-ray microscopy and compares these latter techniques with heavy-ion microscopy. The resolution obtained with these various types of microscopy are compared and the influence of the etching procedure on total resolution is discussed. Several micrographs of mammalian cells are included

  12. Transmission Electron Microscopy Specimen Preparation Method for Multiphase Porous Functional Ceramics

    DEFF Research Database (Denmark)

    Zhang, Wei; Kuhn, Luise Theil; Jørgensen, Peter Stanley

    2013-01-01

    An optimum method is proposed to prepare thin foil transmission electron microscopy (TEM) lamellae of multiphase porous functional ceramics: prefilling the pore space of these materials with an epoxy resin prior to focused ion beam milling. Several advantages of epoxy impregnation are demonstrated...... by successful preparation of TEM specimens that maintain the structural integrity of the entire lamella. Feasibility of the TEM alignment procedure is demonstrated, and ideal TEM analyses are illustrated on solid oxide fuel cell and solid oxide electrolysis cell materials. Some potential drawbacks of the TEM...

  13. NPP Multi-Biome: TEM Calibration Data, 1992, R1

    Data.gov (United States)

    National Aeronautics and Space Administration — This data set contains one data file (.csv format) that is known as the Terrestrial Ecosystem Model (TEM) data set. The data provide pool sizes and fluxes of carbon...

  14. NPP Multi-Biome: TEM Calibration Data, 1992, R1

    Data.gov (United States)

    National Aeronautics and Space Administration — ABSTRACT: This data set contains one data file (.csv format) that is known as the Terrestrial Ecosystem Model (TEM) data set. The data provide pool sizes and fluxes...

  15. Conservation through payments for an ecosys- tem service?

    African Journals Online (AJOL)

    tem service? In his Spotlights ... functions” and “ecosystem services” are being ridiculed by the developments in ... high price as legal marketing would avoid various middlemen. ... Diagnostic participatif de la gestion des ressources naturelles.

  16. Preparation of carbon-free TEM microgrids by metal sputtering

    International Nuclear Information System (INIS)

    Janbroers, S.; Kruijff, T.R. de; Xu, Q.; Kooyman, P.J.; Zandbergen, H.W.

    2009-01-01

    A new method for preparing carbon-free, temperature-stable Transmission Electron Microscope (TEM) grids is presented. An 80% Au/20% Pd metal film is deposited onto a 'holey' microgrid carbon supported on standard mixed-mesh Au TEM grids. Subsequently, the carbon film is selectively removed using plasma cleaning. In this way, an all-metal TEM film is made containing the 'same' microgrid as the original carbon film. Although electron transparency of the foil is reduced significantly, the open areas for TEM inspection of material over these areas are maintained. The metal foil can be prepared with various thicknesses and ensures good electrical conductivity. The new Au/Pd grids are stable to at least 775 K under vacuum conditions.

  17. Preparation of carbon-free TEM microgrids by metal sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Janbroers, S., E-mail: stephan.janbroers@albemarle.com [Albemarle Catalysts B.V., Nieuwendammerkade 1-3, 1030 BE, Amsterdam (Netherlands); Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft (Netherlands); Kruijff, T.R. de; Xu, Q. [Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft (Netherlands); Kooyman, P.J. [DelftChemTech, Delft University of Technology, Julianalaan 136, 2628 BL, Delft (Netherlands); Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft (Netherlands); Zandbergen, H.W. [Kavli Institute of Nanoscience, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft (Netherlands)

    2009-08-15

    A new method for preparing carbon-free, temperature-stable Transmission Electron Microscope (TEM) grids is presented. An 80% Au/20% Pd metal film is deposited onto a 'holey' microgrid carbon supported on standard mixed-mesh Au TEM grids. Subsequently, the carbon film is selectively removed using plasma cleaning. In this way, an all-metal TEM film is made containing the 'same' microgrid as the original carbon film. Although electron transparency of the foil is reduced significantly, the open areas for TEM inspection of material over these areas are maintained. The metal foil can be prepared with various thicknesses and ensures good electrical conductivity. The new Au/Pd grids are stable to at least 775 K under vacuum conditions.

  18. Preparation of carbon-free TEM microgrids by metal sputtering.

    Science.gov (United States)

    Janbroers, S; de Kruijff, T R; Xu, Q; Kooyman, P J; Zandbergen, H W

    2009-08-01

    A new method for preparing carbon-free, temperature-stable Transmission Electron Microscope (TEM) grids is presented. An 80% Au/20% Pd metal film is deposited onto a 'holey' microgrid carbon supported on standard mixed-mesh Au TEM grids. Subsequently, the carbon film is selectively removed using plasma cleaning. In this way, an all-metal TEM film is made containing the 'same' microgrid as the original carbon film. Although electron transparency of the foil is reduced significantly, the open areas for TEM inspection of material over these areas are maintained. The metal foil can be prepared with various thicknesses and ensures good electrical conductivity. The new Au/Pd grids are stable to at least 775K under vacuum conditions.

  19. Regulation of ETG turbulence by TEM driven zonal flows

    Science.gov (United States)

    Asahi, Yuuichi; Ishizawa, Akihiro; Watanabe, Tomohiko; Tsutsui, Hiroaki; Tsuji-Iio, Shunji

    2013-10-01

    Anomalous heat transport driven by electron temperature gradient (ETG) turbulence is investigated by means of gyrokinetic simulations. It is found that the ETG turbulence can be suppressed by zonal flows driven by trapped electron modes (TEMs). The TEMs appear in a statistically steady state of ETG turbulence and generate zonal flows, while its growth rate is much smaller than those of ETGs. The TEM-driven zonal flows with lower radial wave numbers are more strongly generated than those driven by ETG modes, because of the higher zonal flow response to a density source term. An ExB shearing rate of the TEM-driven zonal flows is strong enough to suppress the long-wavelength ETG modes which make the main contribution to the turbulent transport.

  20. Indications and techniques of transanal endoscopic microsurgery (TEMS).

    Science.gov (United States)

    Qi, Yanjie; Stoddard, David; Monson, John R T

    2011-08-01

    Transanal endoscopic microsurgery (TEMS) has recently reemerged as a valuable technique for the management of rectal neoplasms - both benign and malignant. Since the original description of this technique in the early 1980s, TEMS has emerged as the approach of choice for most benign rectal tumors because of the excellent views provided and superior dissection techniques possible when compared to traditional transanal excision. Many published reports demonstrate that the lowest rates of recurrence are associated with TEMS probably because of full-thickness excision with negative margins. Increasingly, TEMS is being applied to primary rectal cancer when used alone as a full-thickness excision alone or in combination with additional therapies, depending on tumor stage. There is now a significant evidence base to suggest that this approach should be considered as part of a multidisciplinary approach to rectal cancer. This paper describes indications and techniques for this technology.

  1. Coordinated Isotopic and TEM Studies of Presolar Graphites from Murchison

    Science.gov (United States)

    Croat, T. K.; Stadermann, F. J.; Zinner, E.; Bernatowicz, T. J.

    2004-03-01

    TEM and NanoSIMS investigations of the same presolar Murchison KFC graphites revealed high Zr, Mo, and Ru content in refractory carbides within the graphites. Along with isotopically light carbon, these suggest a low-metallicity AGB source.

  2. Comparison of ultramicrotomy and focused-ion-beam for the preparation of TEM and STEM cross section of organic solar cells

    DEFF Research Database (Denmark)

    Corazza, Michael; Simonsen, Søren Bredmose; Gnaegi, Helmut

    2016-01-01

    The challenge of preparing cross sections of organic photovoltaics (OPV) suitable for transmission electron microscopy (TEM) and scanning TEM (STEM) is addressed. The samples were polymer solar cells fabricated using roll-to-roll (R2R) processing methods on a flexible polyethylene terephthalate...... resolution, enabling further studies of phase separation of P3HT:PCBM by means of energy filtered TEM (EFTEM). The sample prepared by FIB shows good structure preservation, but reduced resolution due to non-optimal thicknesses achieved after treatment. Degradation studies of samples prepared...

  3. Correlative microscopy of a carbide-free bainitic steel.

    Science.gov (United States)

    Hofer, Christina; Bliznuk, Vitaliy; Verdiere, An; Petrov, Roumen; Winkelhofer, Florian; Clemens, Helmut; Primig, Sophie

    2016-02-01

    In this work a carbide-free bainitic steel was examined by a novel correlative microscopy approach using transmission Kikuchi diffraction (TKD) and transmission electron microscopy (TEM). The individual microstructural constituents could be identified by TKD based on their different crystal structure for bainitic ferrite and retained austenite and by image quality for the martensite-austenite (M-A) constituent. Subsequently, the same area was investigated in the TEM and a good match of these two techniques regarding the identification of the area position and crystal orientation could be proven. Additionally, the M-A constituent was examined in the TEM for the first time after preceded unambiguous identification using a correlative microscopy approach. The selected area diffraction pattern showed satellites around the main reflexes which might indicate a structural modulation. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Study of InGaN/GaN quantum dot systems by TEM techniques and photoluminescence spectroscopy

    International Nuclear Information System (INIS)

    Kashtiban, R J; Bangert, U; Harvey, A J; Sherliker, B; Halsall, M P

    2010-01-01

    InGaN/GaN multilayer quantum dot structures produced by MOCVD techniques on c-plane sapphire were studied by transmission electron microscopy (TEM) and photoluminescence (PL) techniques. Indium fluctuations ranging from 1-4 nm were observed with both energy filtered TEM (EFTEM) and high angle annular dark field (HAADF) scanning TEM. The existence of V-shaped defects with nucleation centres at the termination of threading dislocation were observed in HAADF images. There was also evidence of the formation of large quantum dots at low densities from lattice HRTEM images. This was further confirmed by PL measurements through the observation of a single sharp line at low power with the typical saturation behaviour at higher power excitation.

  5. EBSD and FIB/TEM examination of shape memory effect deformation structures in U-14 at.% Nb

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, A.J. [Materials Science and Technology Division, Mail Stop G770, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)], E-mail: aclarke@lanl.gov; Field, R.D.; McCabe, R.J.; Cady, C.M.; Hackenberg, R.E.; Thoma, D.J. [Materials Science and Technology Division, Mail Stop G770, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2008-06-15

    Detailed examinations of shape memory effect (SME) deformation structures in martensite of U-14 at.% Nb were performed with electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). An accommodation strain analysis, which has been previously used to predict SME deformation structures and texture evolution in polycrystalline material, was also performed. Martensite variants and twin relationships observed with EBSD after compressive or tensile deformation were determined to be consistent with those expected from calculated accommodation strains. Focused ion beam (FIB) was used to select twinned regions identified with EBSD for more detailed TEM analysis to verify the presence of these specific twins. The observed SME twinning systems in the martensite agree with previous TEM observations and the predicted {l_brace}1-bar76{r_brace} twinning system was observed experimentally for the first time in U-14 at.% Nb using these complementary techniques.

  6. In Situ TEM Multi-Beam Ion Irradiation as a Technique for Elucidating Synergistic Radiation Effects

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, Caitlin; Bufford, Daniel; Muntifering, Brittany; Senor, David; Steckbeck, Mackenzie; Davis, Justin; Doyle, Barney; Buller, Daniel; Hattar, Khalid

    2017-09-29

    Materials designed for nuclear reactors undergo microstructural changes resulting from a combination of several environmental factors, including neutron irradiation damage, gas accumulation and elevated temperatures. Typical ion beam irradiation experiments designed for simulating a neutron irradiation environment involve irradiating the sample with a single ion beam and subsequent characterization of the resulting microstructure, often by transmission electron microscopy (TEM). This method does not allow for examination of microstructural effects due to simultaneous gas accumulation and displacement cascade damage, which occurs in a reactor. Sandia’s in situ ion irradiation TEM (I3TEM) offers the unique ability to observe microstructural changes due to irradiation damage caused by concurrent multi-beam ion irradiation in real time. This allows for time-dependent microstructure analysis. A plethora of additional in situ stages can be coupled with these experiments, e.g., for more accurately simulating defect kinetics at elevated reactor temperatures. This work outlines experiments showing synergistic effects in Au using in situ ion irradiation with various combinations of helium, deuterium and Au ions, as well as some initial work on materials utilized in tritium-producing burnable absorber rods (TPBARs): zirconium alloys and LiAlO2.

  7. Application of SEM/EBSD and FEG-TEM/CBED to determine eutectic solidification mechanisms

    International Nuclear Information System (INIS)

    Nogita, K.; Dahle, A.K.; Drennan, J.

    2002-01-01

    Full text: This study shows the application of electron backscatter diffraction (EBSD) in SEM and convergent beam electron diffraction (CBED) in FEG-TEM to determine eutectic nucleation and growth in hypoeutectic Al-Si foundry alloys. Because the eutectic reaction is often the final stage of solidification it can be expected to have a significant impact on the formation of casting defects, particularly porosity. Previous EBSD work by Nogita and Dahle (2001), Dahle et al (2001), has shown that the eutectic nucleates on the primary phase in the unmodified alloy, and eutectic grains are nucleated in the intergranular liquid, instead of filling the dendrite envelopes, when Sr or Sb is added. However, the orientation relationship between silicon and aluminium in the eutectic has so far not been determined because of difficulties with sample preparation for EBSD and also detection limitations of Kikuchi refraction of silicon and aluminium, particularly in modified alloys with a refined eutectic. The combination of the EBSD technique in SEM and CBED in TEM analyses can provide crystallographic orientation relationships between primary aluminium dendrites, eutectic aluminium and silicon, which are important to explicitly define the solidification mode of the eutectic in hypoeutectic Al-Si alloys. These relationships are influenced, and altered, by the addition of certain elements. This paper also describes the sample preparation techniques for SEM and TEM for samples with different eutectic structures. The advantages the techniques are discussed. Copyright (2002) Australian Society for Electron Microscopy Inc

  8. Synthesis, XRD, TEM, EPR, and Optical Absorption Spectral Studies of CuZnO2 Nanocompound

    Directory of Open Access Journals (Sweden)

    T. Ravindra Reddy

    2014-01-01

    Full Text Available Synthesis of nano CuZnO2 compound is carried out by thermal decomposition method. The crystalline phase of the material is characterized by XRD. The calculated unit cell constants are a=3.1 Å and c=3.4786 Å and are of tetragonal structure. The unit cell constants are different from wurtzite (hexagonal which indicate that a nanocompound is formed. Further TEM images reveal that the metal ion is in tetragonal structure with oxygen ligands. The prepared CuZnO2 is then characterized for crystallite size analysis by employing transmission electron microscopy (TEM. The size is found to be 100 nm. Uniform bright rings are noticed in the TEM picture suggesting that the nanocrystals have preferential instead of random orientations. The selected-area electron diffraction (SAED pattern clearly indicates the formation of CuO-ZnO nanocompound. The nature of bonding is studied by electron paramagnetic resonance (EPR. The covalency character is about 0.74 and thus the compound is electrically less conductive. Optical absorption spectral studies suggest that Cu(II is placed in tetragonal elongation crystal field. The spin-orbit coupling constant, λ, is calculated using the EPR and optical absorption spectral results suggest some covalent bond between metal and ligand. Near infrared (NIR spectra are due to hydroxyl and water fundamentals.

  9. In Situ TEM Multi-Beam Ion Irradiation as a Technique for Elucidating Synergistic Radiation Effects

    Directory of Open Access Journals (Sweden)

    Caitlin Anne Taylor

    2017-09-01

    Full Text Available Materials designed for nuclear reactors undergo microstructural changes resulting from a combination of several environmental factors, including neutron irradiation damage, gas accumulation and elevated temperatures. Typical ion beam irradiation experiments designed for simulating a neutron irradiation environment involve irradiating the sample with a single ion beam and subsequent characterization of the resulting microstructure, often by transmission electron microscopy (TEM. This method does not allow for examination of microstructural effects due to simultaneous gas accumulation and displacement cascade damage, which occurs in a reactor. Sandia’s in situ ion irradiation TEM (I3TEM offers the unique ability to observe microstructural changes due to irradiation damage caused by concurrent multi-beam ion irradiation in real time. This allows for time-dependent microstructure analysis. A plethora of additional in situ stages can be coupled with these experiments, e.g., for more accurately simulating defect kinetics at elevated reactor temperatures. This work outlines experiments showing synergistic effects in Au using in situ ion irradiation with various combinations of helium, deuterium and Au ions, as well as some initial work on materials utilized in tritium-producing burnable absorber rods (TPBARs: zirconium alloys and LiAlO2.

  10. Post Irradiation TEM Investigation of ZrN Coated U(Mo) Particles Prepared with FIB

    Energy Technology Data Exchange (ETDEWEB)

    Van Renterghem, W.; Leenaers, A.; Van den Berghe, S.; Miller, B. D.; Gan, J.; Madden, J. W.; Keiser, D. D.; Palancher, H.; Hofman, G. L.; Breitkreuz, H.

    2015-10-01

    In the framework of the Selenium project, two dispersion fuel plates were fabricated with Si and ZrN coated fuel particles and irradiated in the Br2 reactor of SCK•CEN to high burn-up. The first analysis of the irradiated plate proved the reduced swelling of the fuel plate and interaction layer growth up to 70% burn-up. The question was raised how the structure of the interaction layer had been affected by the irradiation and how the structure of the fuel particles had evolved. Hereto, samples from the ZrN coated UMo particles were prepared for transmission electron microscopy (TEM) using focused ion beam milling (FIB) at INL. The FIB technique allowed to precisely select the area of the interaction layer and/or fuel to produce a sample that is TEM transparent over an area of 20 by 20 µm. In this contribution, the first TEM results will be presented from the 66% burn-up sample.

  11. Distortion of DNA Origami on Graphene Imaged with Advanced TEM Techniques.

    Science.gov (United States)

    Kabiri, Yoones; Ananth, Adithya N; van der Torre, Jaco; Katan, Allard; Hong, Jin-Yong; Malladi, Sairam; Kong, Jing; Zandbergen, Henny; Dekker, Cees

    2017-08-01

    While graphene may appear to be the ultimate support membrane for transmission electron microscopy (TEM) imaging of DNA nanostructures, very little is known if it poses an advantage over conventional carbon supports in terms of resolution and contrast. Microscopic investigations are carried out on DNA origami nanoplates that are supported onto freestanding graphene, using advanced TEM techniques, including a new dark-field technique that is recently developed in our lab. TEM images of stained and unstained DNA origami are presented with high contrast on both graphene and amorphous carbon membranes. On graphene, the images of the origami plates show severe unwanted distortions, where the rectangular shape of the nanoplates is significantly distorted. From a number of comparative control experiments, it is demonstrated that neither staining agents, nor screening ions, nor the level of electron-beam irradiation cause this distortion. Instead, it is suggested that origami nanoplates are distorted due to hydrophobic interaction of the DNA bases with graphene upon adsorption of the DNA origami nanoplates. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. "Rinse and trickle": a protocol for TEM preparation and investigation of inorganic fibers from biological material.

    Science.gov (United States)

    Vigliaturo, Ruggero; Capella, Silvana; Rinaudo, Caterina; Belluso, Elena

    2016-07-01

    The purpose of this work is to define a sample preparation protocol that allows inorganic fibers and particulate matter extracted from different biological samples to be characterized morphologically, crystallographically and chemically by transmission electron microscopy-energy dispersive spectroscopy (TEM-EDS). The method does not damage or create artifacts through chemical attacks of the target material. A fairly rapid specimen preparation is applied with the aim of performing as few steps as possible to transfer the withdrawn inorganic matter onto the TEM grid. The biological sample is previously digested chemically by NaClO. The salt is then removed through a series of centrifugation and rinse cycles in deionized water, thus drastically reducing the digestive power of the NaClO and concentrating the fibers for TEM analysis. The concept of equivalent hydrodynamic diameter is introduced to calculate the settling velocity during the centrifugation cycles. This technique is applicable to lung tissues and can be extended to a wide range of organic materials. The procedure does not appear to cause morphological damage to the fibers or modify their chemistry or degree of crystallinity. The extrapolated data can be used in interdisciplinary studies to understand the pathological effects caused by inorganic materials.

  13. Studying the interface between cyanobacteria and biotite mineral surfaces using FIB and TEM

    International Nuclear Information System (INIS)

    Ward, M B; Brown, A P

    2014-01-01

    Recent analysis of the bioweathering of minerals has highlighted the challenges for investigating the interface between fungi or bacteria and the surface of the mineral that they live on. Transmission electron microscopy (TEM) with its ability to gather imaging information and collect elemental data at high spatial resolution is the ideal technique to analyse such interfaces. Further to this, a dual beam scanning electron and focused ion beam (FIB) microscope is an ideal instrument to prepare specimens for TEM because of its ability to simultaneously cut through hard and soft materials from specific sites of interest. There are however precautions that must be taken when analysing such mineral systems. The electron beam sensitive nature of most sheet silicate minerals means that consideration has to be made as to whether the structure and/or chemistry of the material is being altered during (S)TEM analysis. Here, results from a study of cyanobacteria grown on the surface of biotite are discussed. Particular reference is given to the methods used to determine an electron beam intensity threshold, below which STEM-EDX analysis could be performed without detrimental alteration to the mineral

  14. GISAXS modelling of helium-induced nano-bubble formation in tungsten and comparison with TEM

    Science.gov (United States)

    Thompson, Matt; Sakamoto, Ryuichi; Bernard, Elodie; Kirby, Nigel; Kluth, Patrick; Riley, Daniel; Corr, Cormac

    2016-05-01

    Grazing-incidence small angle x-ray scattering (GISAXS) is a powerful non-destructive technique for the measurement of nano-bubble formation in tungsten under helium plasma exposure. Here, we present a comparative study between transmission electron microscopy (TEM) and GISAXS measurements of nano-bubble formation in tungsten exposed to helium plasma in the Large Helical Device (LHD) fusion experiment. Both techniques are in excellent agreement, suggesting that nano-bubbles range from spheroidal to ellipsoidal, displaying exponential diameter distributions with mean diameters μ=0.68 ± 0.04 nm and μ=0.6 ± 0.1 nm measured by TEM and GISAXS respectively. Depth distributions were also computed, with calculated exponential depth distributions with mean depths of 8.4 ± 0.5 nm and 9.1 ± 0.4 nm for TEM and GISAXS. In GISAXS modelling, spheroidal particles were fitted with an aspect ratio ε=0.7 ± 0.1. The GISAXS model used is described in detail.

  15. In Situ Environmental TEM in Imaging Gas and Liquid Phase Chemical Reactions for Materials Research.

    Science.gov (United States)

    Wu, Jianbo; Shan, Hao; Chen, Wenlong; Gu, Xin; Tao, Peng; Song, Chengyi; Shang, Wen; Deng, Tao

    2016-11-01

    Gas and liquid phase chemical reactions cover a broad range of research areas in materials science and engineering, including the synthesis of nanomaterials and application of nanomaterials, for example, in the areas of sensing, energy storage and conversion, catalysis, and bio-related applications. Environmental transmission electron microscopy (ETEM) provides a unique opportunity for monitoring gas and liquid phase reactions because it enables the observation of those reactions at the ultra-high spatial resolution, which is not achievable through other techniques. Here, the fundamental science and technology developments of gas and liquid phase TEM that facilitate the mechanistic study of the gas and liquid phase chemical reactions are discussed. Combined with other characterization tools integrated in TEM, unprecedented material behaviors and reaction mechanisms are observed through the use of the in situ gas and liquid phase TEM. These observations and also the recent applications in this emerging area are described. The current challenges in the imaging process are also discussed, including the imaging speed, imaging resolution, and data management. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. 3D TEM reconstruction and segmentation process of laminar bio-nanocomposites

    International Nuclear Information System (INIS)

    Iturrondobeitia, M.; Okariz, A.; Fernandez-Martinez, R.; Jimbert, P.; Guraya, T.; Ibarretxe, J.

    2015-01-01

    The microstructure of laminar bio-nanocomposites (Poly (lactic acid)(PLA)/clay) depends on the amount of clay platelet opening after integration with the polymer matrix and determines the final properties of the material. Transmission electron microscopy (TEM) technique is the only one that can provide a direct observation of the layer dispersion and the degree of exfoliation. However, the orientation of the clay platelets, which affects the final properties, is practically immeasurable from a single 2D TEM image. This issue can be overcome using transmission electron tomography (ET), a technique that allows the complete 3D characterization of the structure, including the measurement of the orientation of clay platelets, their morphology and their 3D distribution. ET involves a 3D reconstruction of the study volume and a subsequent segmentation of the study object. Currently, accurate segmentation is performed manually, which is inefficient and tedious. The aim of this work is to propose an objective/automated segmentation methodology process of a 3D TEM tomography reconstruction. In this method the segmentation threshold is optimized by minimizing the variation of the dimensions of the segmented objects and matching the segmented V clay (%) and the actual one. The method is first validated using a fictitious set of objects, and then applied on a nanocomposite

  17. Novel Transrotational Solid State Order Discovered by TEM in Crystallizing Amorphous Films

    Science.gov (United States)

    Kolosov, Vladimir

    Exotic thin crystals with unexpected transrotational microstructures have been discovered by transmission electron microscopy (TEM) for crystal growth in thin (10-100 nm) amorphous films of different chemical nature (oxides, chalcogenides, metals and alloys) prepared by various methods. Primarily we use our TEM bend contour technique. The unusual phenomenon can be traced in situ in TEM column: dislocation independent regular internal bending of crystal lattice planes in a growing crystal. Such transrotation (unit cell trans lation is complicated by small rotationrealized round an axis lying in the film plane) can result in strong regular lattice orientation gradients (up to 300 degrees per micrometer) of different geometries: cylindrical, ellipsoidal, toroidal, saddle, etc. Transrotation is increasing as the film gets thinner. Transrotational crystal resembles ideal single crystal enclosed in a curved space. Transrotational micro crystals have been eventually recognized by other authors in some vital thin film materials, i.e. PCMs for memory, silicides, SrTiO3. Atomic model and possible mechanisms of the phenomenon are discussed. New transrotational nanocrystalline model of amorphous state is also proposed Support of RF Ministry of Education and Science is acknowledged.

  18. ToTem: a tool for variant calling pipeline optimization.

    Science.gov (United States)

    Tom, Nikola; Tom, Ondrej; Malcikova, Jitka; Pavlova, Sarka; Kubesova, Blanka; Rausch, Tobias; Kolarik, Miroslav; Benes, Vladimir; Bystry, Vojtech; Pospisilova, Sarka

    2018-06-26

    High-throughput bioinformatics analyses of next generation sequencing (NGS) data often require challenging pipeline optimization. The key problem is choosing appropriate tools and selecting the best parameters for optimal precision and recall. Here we introduce ToTem, a tool for automated pipeline optimization. ToTem is a stand-alone web application with a comprehensive graphical user interface (GUI). ToTem is written in Java and PHP with an underlying connection to a MySQL database. Its primary role is to automatically generate, execute and benchmark different variant calling pipeline settings. Our tool allows an analysis to be started from any level of the process and with the possibility of plugging almost any tool or code. To prevent an over-fitting of pipeline parameters, ToTem ensures the reproducibility of these by using cross validation techniques that penalize the final precision, recall and F-measure. The results are interpreted as interactive graphs and tables allowing an optimal pipeline to be selected, based on the user's priorities. Using ToTem, we were able to optimize somatic variant calling from ultra-deep targeted gene sequencing (TGS) data and germline variant detection in whole genome sequencing (WGS) data. ToTem is a tool for automated pipeline optimization which is freely available as a web application at  https://totem.software .

  19. Novel in-situ lamella fabrication technique for in-situ TEM.

    Science.gov (United States)

    Canavan, Megan; Daly, Dermot; Rummel, Andreas; McCarthy, Eoin K; McAuley, Cathal; Nicolosi, Valeria

    2018-03-29

    In-situ transmission electron microscopy is rapidly emerging as the premier technique for characterising materials in a dynamic state on the atomic scale. The most important aspect of in-situ studies is specimen preparation. Specimens must be electron transparent and representative of the material in its operational state, amongst others. Here, a novel fabrication technique for the facile preparation of lamellae for in-situ transmission electron microscopy experimentation using focused ion beam milling is developed. This method involves the use of rotating microgrippers during the lift-out procedure, as opposed to the traditional micromanipulator needle and platinum weld. Using rotating grippers, and a unique adhesive substance, lamellae are mounted onto a MEMS device for in-situ TEM annealing experiments. We demonstrate how this technique can be used to avoid platinum deposition as well as minimising damage to the MEMS device during the thinning process. Our technique is both a cost effective and readily implementable alternative to the current generation of preparation methods for in-situ liquid, electrical, mechanical and thermal experimentation within the TEM as well as traditional cross-sectional lamella preparation. Copyright © 2018 Elsevier B.V. All rights reserved.

  20. Cross section TEM characterization of high-energy-Xe-irradiated U-Mo

    Energy Technology Data Exchange (ETDEWEB)

    Ye, B., E-mail: bye@anl.gov [Nuclear Engineering Division, Argonne National Laboratory, 9700 S. Cass Ave. Lemont, IL 60439 (United States); Jamison, L.; Miao, Y. [Nuclear Engineering Division, Argonne National Laboratory, 9700 S. Cass Ave. Lemont, IL 60439 (United States); Bhattacharya, S. [Department of Materials Science and Engineering, Northwestern University, 2220 Campus Dr. Evanston, IL 60208 (United States); Hofman, G.L.; Yacout, A.M. [Nuclear Engineering Division, Argonne National Laboratory, 9700 S. Cass Ave. Lemont, IL 60439 (United States)

    2017-05-15

    U-Mo alloys irradiated with 84 MeV Xe ions to various doses were characterized with transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) techniques. The TEM thin foils were prepared perpendicular to the irradiated surface to allow a direct observation of the entire region modified by ions. Therefore, depth-selective microstructural information was revealed. Varied irradiation-induced phenomena such as gas bubble formation, phase reversal, and recrystallization were observed at different ion penetration depths in U-Mo. - Highlights: •Three distinct zones were observed along the ion traveling direction in U-7Mo irradiated with 84 MeV Xe ions at 350 °C. •The α-U particles within the Xe-implanted region were reverted to γ-U phase by irradiation. •High-density random intra-granular bubbles in a size of 4–5 nm were found in the irradiated region, coexisting with large inter-granular bubbles. •The high lattice stresses built up during the irradiation-induced phase reversal is probably the driving force for the small grain formation at cell boundaries.

  1. Determination of the activation energy in a cast aluminium alloy by TEM and DSC

    International Nuclear Information System (INIS)

    Ovono Ovono, D.; Guillot, I.; Massinon, D.

    2007-01-01

    The precipitation behaviour and microstructure development of the A319 alloy during ageing were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM and STEM). During T5 treatment, θ' precipitates with an average size of about 18 nm were observed by TEM. The precipitate sizes increased with ageing temperature and attained an average size of 107 nm. In addition, there was a linear relationship between precipitate growth temperature and the cube of the precipitate size. This indicates that precipitate growth of the A319 alloy belongs to a thermal activated process of the Arrhenius type. The activation energy for the precipitate growth was calculated to be 140.4 ± 13.3 kJ/mol. However, under continuous heating conditions, the activation energy for the precipitate growth obtained by Kissinger plot was determined to be 119.5 ± 8.3 kJ/mol. Allowing for experimental error, both values are comparable and are related to the diffusion of Cu and/or Si in Al

  2. Characterization of mineral particles in winter fog of Beijing analyzed by TEM and SEM.

    Science.gov (United States)

    Li, Weijun; Shao, Longyi

    2010-02-01

    Aerosol samples were collected during winter fog and nonfog episodes in Beijing. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) were applied to study morphologies, sizes, and compositions of aerosol particles. TEM observation indicates that most mineral particles collected in fog episode are scavenged in fog droplets. Number-size distributions of mineral particles collected in fog and nonfog episodes show two main peaks at the ranges of 0.1-0.3 and 1-2.5 microm, respectively. Based on their major compositions, mineral particles mainly include Si-rich, Ca-rich, and S-rich. Average S/Ca ratio of mineral particles collected in fog episode is 6.11, being eight times higher than that in nonfog episodes. Development mechanism of individual mineral particles in fog droplets is proposed. It is suggested that mineral particles with abundant alkaline components (e.g., "Ca-rich" particles) occurred in air should alleviate acidic degree of fog and contribute to complexity of fog droplets in Beijing.

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

    International Nuclear Information System (INIS)

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

    2007-01-01

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

  4. TEM characterization of catalyst- and mask-free grown GaN nanorods

    International Nuclear Information System (INIS)

    Schowalter, M; Aschenbrenner, T; Kruse, C; Hommel, D; Rosenauer, A

    2010-01-01

    Catalyst- and mask-free grown GaN nanorods have been investigated using transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM) and energy filtered transmission electron microscopy (EFTEM). The nanorods were grown on nitridated r-plane sapphire substrates in a molecular beam epitaxy reactor. We investigated samples directly after the nitridation and after the overgrowth of the structure with GaN. High resolution transmission electron microscopy (HRTEM) and EFTEM revealed that AlN islands have formed due to nitridation. After overgrowth, the AlN islands could not be observed any more, neither by EFTEM nor by Z-contrast imaging. Instead, a smooth layer consisting of AlGaN was found. The investigation of the overgrown sample revealed that an a-plane GaN layer and GaN nanorods on top of the a-plane GaN have formed. The nanorods reduced from top of the a-plane GaN towards the a-plane GaN/sapphire interface suggesting that the nanorods originate at the AlN islands found after nitridation. However, this could not be shown unambiguously. The number of threading dislocations in the nanorods was very low. The analysis of the epitaxial relationship to the a-plane GaN showed that the nanorods grew along the [000-1] direction, and the [1-100] direction of the rods was parallel to the [0001] direction of the a-plane GaN.

  5. Optimized pre-thinning procedures of ion-beam thinning for TEM sample preparation by magnetorheological polishing.

    Science.gov (United States)

    Luo, Hu; Yin, Shaohui; Zhang, Guanhua; Liu, Chunhui; Tang, Qingchun; Guo, Meijian

    2017-10-01

    Ion-beam-thinning is a well-established sample preparation technique for transmission electron microscopy (TEM), but tedious procedures and labor consuming pre-thinning could seriously reduce its efficiency. In this work, we present a simple pre-thinning technique by using magnetorheological (MR) polishing to replace manual lapping and dimpling, and demonstrate the successful preparation of electron-transparent single crystal silicon samples after MR polishing and single-sided ion milling. Dimples pre-thinned to less than 30 microns and with little mechanical surface damage were repeatedly produced under optimized MR polishing conditions. Samples pre-thinned by both MR polishing and traditional technique were ion-beam thinned from the rear side until perforation, and then observed by optical microscopy and TEM. The results show that the specimen pre-thinned by MR technique was free from dimpling related defects, which were still residual in sample pre-thinned by conventional technique. Nice high-resolution TEM images could be acquired after MR polishing and one side ion-thinning. MR polishing promises to be an adaptable and efficient method for pre-thinning in preparation of TEM specimens, especially for brittle ceramics. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. In-Situ TEM Study of a Nanoporous Ni–Co Catalyst Used for the Dry Reforming of Methane

    Directory of Open Access Journals (Sweden)

    Takeshi Fujita

    2017-10-01

    Full Text Available We performed in-situ transmission electron microscopy (TEM on a dealloyed nanoporous NiCo catalyst used for the dry reforming of methane (DRM to investigate the origin of the catalytic activity and structural durability. The in-situ observations and local chemical analysis indicated that the DRM induced chemical demixing of Ni and Co accompanied by grain refinement, implying possible “synergic effects” in a general bimetallic NiCo catalyst when used for the DRM.

  7. Novel sample preparation for operando TEM of catalysts.

    Science.gov (United States)

    Miller, Benjamin K; Barker, Trevor M; Crozier, Peter A

    2015-09-01

    A new TEM sample preparation method is developed to facilitate operando TEM of gas phase catalysis. A porous Pyrex-fiber pellet TEM sample was produced, allowing a comparatively large amount of catalyst to be loaded into a standard Gatan furnace-type tantalum heating holder. The increased amount of catalyst present inside the environmental TEM allows quantitative determination of the gas phase products of a catalytic reaction performed in-situ at elevated temperatures. The product gas concentration was monitored using both electron energy loss spectroscopy (EELS) and residual gas analysis (RGA). Imaging of catalyst particles dispersed over the pellet at atomic resolution is challenging, due to charging of the insulating glass fibers. To overcome this limitation, a metal grid is placed into the holder in addition to the pellet, allowing catalyst particles dispersed over the grid to be imaged, while particles in the pellet, which are assumed to experience identical conditions, contribute to the overall catalytic conversion inside the environmental TEM cell. The gas within the cell is determined to be well-mixed, making this assumption reasonable. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Exploration of shallow subsurface resistivity structure using a portable TEM system: TEM-FAST prosystem; Kan`igata TEM ho sochi TEM-FAST prosystem ni yoru senbu hiteiko chosa

    Energy Technology Data Exchange (ETDEWEB)

    Miura, Y; Kumekawa, Y; Takasugi, S [GERD Geothermal Energy Research and Development Co. Ltd., Tokyo (Japan)

    1997-05-27

    Discussions were given on effectiveness of the TEM-FAST ProSystem which is a portable TEM system developed recently for use in exploration of shallow subsurface resistivity. The system consists of a loop type antenna, the TEM-FAST as the main equipment, and a host computer, the host computer controlling the entire system. The system acquires transient response data in secondary induced magnetic fields lasting 4 {mu} sec to 1 m sec. The number of data is 5490 stacks in one measurement, and the data acquisition time is about three minutes. Measurements were carried out by using the TEM-FAST in the vicinity of a well, whose results were compared with those of electric logging, and discussions were given on them. Although the electric logging results had no data available for depths shallower than 35 m, the measurement results from the TEM-FAST were found highly harmonious with those of the electric logging. In addition, there were transmission and telephone lines in locations about 10 m away from the well during the measurement, but extremely high data quality was discovered. 6 refs., 7 figs., 1 tab.

  9. Transmission Electron Microscopy Study of Individual Carbon Nanotube Breakdown Caused by Joule Heating in Air

    DEFF Research Database (Denmark)

    Mølhave, Kristian; Gudnason, S.B.; Pedersen, Anders Tegtmeier

    2006-01-01

    We present repeated structural and electrical measurements on individual multiwalled carbon nanotubes, alternating between electrical measurements under ambient conditions and transmission electron microscopy (TEM). The multiwalled carbon nanotubes made by chemical vapor deposition were manipulated...

  10. Performance of a field emission gun TEM/STEM

    International Nuclear Information System (INIS)

    Carpenter, R.W.; Bentley, J.

    1979-01-01

    First experimental results on a Phillips EM 400 TEM/STEM fitted with a field-emission electron gun and objective twin lens are given here. Operation of the FEG is reliable up to maximum design voltage (120 kV). Highest resolution achieved in TEM was 1.9 A fringe. A wide variety of diffraction modes were demonstrated, ranging from CBDP from a small area (approx. 10 A dia) in STEM mode to SAD with angular resolution of 8 μrad in TEM mode. The EDS sensitivity is very high. STEM imaging performance to the highest magnifications examined (200 kx) is good. Work is in progress to evaluate the limits of STEM performance

  11. SOFC anode reduction studied by in situ TEM

    DEFF Research Database (Denmark)

    Simonsen, Søren Bredmose; Wagner, Jakob Birkedal; Hansen, Thomas Willum

    The Solid Oxide Fuel Cell (SOFC) is a promising part of future energy approaches due to a relatively high energy conversion efficiency and low environmental pollution. SOFCs are typically composed of ceramic materials which are highly complex at the nanoscale. TEM is routinely applied ex situ...... for studying these nanoscale structures, but only few SOFC studies have applied in situ TEM to observe the ceramic nanostructures in a reactive gas environment at elevated temperatures. The present contribution focuses on the reduction of an SOFC anode which is a necessary process to form the catalytically...... active Ni surface before operating the fuel cells. The reduction process was followed in the TEM while exposing a NiO/YSZ (YSZ = Y2O3-stabilized ZrO2) model anode to H2 at T = 250-1000⁰C. Pure NiO was used in reference experiments. Previous studies have shown that the reduction of pure Ni...

  12. SIMS and TEM study on oxide characteristics of Zircaloy

    International Nuclear Information System (INIS)

    Jung, Y. H.; Baek, J. H.; Kim, S. J.; Kim, K. H.; Choi, B. K.; Jung, Y. H.

    1998-01-01

    Long-term corrosion test, SIMS analysis, and TEM study were carried out to investigate the corrosion characteristics and corrosion mechanism of Zircaloy-4 in LiOH solution. The corrosion tests were performed in alkali solutions at 350 deg C for 500days. SIMS analysis was performed for the specimens prepared to have an equal oxide thickness to measure the cation content. TEM studies on the samples formed in various alkali solutions were also conducted. Based on the corrosion test, SIMS analysis, and TEM study, the cation is considered to control the corrosion in LiOH solution and its effect is dependent on the concentration of alkali and the oxide thickness. The slight acceleration of corrosion rate at a low concentration is thought to be caused by the cation incorporation into oxide while the significant acceleration at a high concentration is due to the transformation of oxide microstructure that would be induced by the cation incorporation

  13. Location specific in situ TEM straining specimens made using FIB

    International Nuclear Information System (INIS)

    Field, R.D.; Papin, P.A.

    2004-01-01

    A method has been devised and demonstrated for producing in situ straining specimens for the transmission electron microscope (TEM) from specific locations in a sample using a dual-beam focused ion beam (FIB) instrument. The specimen is removed from a polished surface in the FIB using normal methods and then attached to a pre-fabricated substrate in the form of a modified TEM tensile specimen. In this manner, specific features of the microstructure of a polished optical mount can be selected for in situ tensile straining. With the use of electron backscattered diffraction (EBSD), this technique could be extended to select specific orientations of the specimen as well

  14. Developments in TEM Nanotomography of Calcium Silicate Hydrate

    KAUST Repository

    Taylor, Rae; Sakdinawat, Anne E.; Chae, Sejung R.; Wenk, Haz Rudolf; Levitz, Pierre E.; Sougrat, Rachid; Monteiro, Paulo José Meleragno

    2015-01-01

    This investigation was designed to explore the possibility of using transmission electron microscope (TEM) tomography on cement-based systems gain a greater understanding of their nanostructure and pore network. The preliminary results show a clearly a well-defined pore network at the nanoscale, with pore size approximately 1.7-2.4 nm in diameter and spaced around 5-8 nm apart. A comparison of small angle X-ray scattering data with 2-D TEM images analyzed with the Fourier slice theorem documents an excellent structural correlation. © 2015 The American Ceramic Society.

  15. Developments in TEM Nanotomography of Calcium Silicate Hydrate

    KAUST Repository

    Taylor, Rae

    2015-04-01

    This investigation was designed to explore the possibility of using transmission electron microscope (TEM) tomography on cement-based systems gain a greater understanding of their nanostructure and pore network. The preliminary results show a clearly a well-defined pore network at the nanoscale, with pore size approximately 1.7-2.4 nm in diameter and spaced around 5-8 nm apart. A comparison of small angle X-ray scattering data with 2-D TEM images analyzed with the Fourier slice theorem documents an excellent structural correlation. © 2015 The American Ceramic Society.

  16. Razvijmo sebe, druge in s tem svoj kraj

    Directory of Open Access Journals (Sweden)

    Dušana Findeisen

    1997-12-01

    Full Text Available Dušana Findeisen v tem prispevku obravnava vprašanje, kako spodbuditi ljudi k soodgovornosti za lasten razvoj in razvoj kraja. Preučuje tudi, kako naj prebivalci postanejo soodgovorni za zadostitev lastnih potreb in potreb njihovega kraja. V zvezi s tem se dotakne vloge izobraževalca odraslih - animatorja lokalnih projektov. Poudarja tudi pomen navezovanja novih odnosov in razmerij med lokalnimi skupnostmi in državo ter uvajanje “strukturalne politike”, kot jo imenuje avtorica, za sistemsko pomoč razvoju lokalnih projektov. Nazadnje pa obravnava vlogo lokalnih projektov z vidika razvoja kraja.

  17. Correlated Light Microscopy and Electron Microscopy

    NARCIS (Netherlands)

    Sjollema, Klaas A.; Schnell, Ulrike; Kuipers, Jeroen; Kalicharan, Ruby; Giepmans, Ben N. G.; MullerReichert, T; Verkade, P

    2012-01-01

    Understanding where, when, and how biomolecules (inter)act is crucial to uncover fundamental mechanisms in cell biology. Recent developments in fluorescence light microscopy (FLM) allow protein imaging in living cells and at the near molecular level. However, fluorescence microscopy only reveals

  18. A short note on how to convert a conventional analytical TEM into an analytical Low Voltage TEM

    International Nuclear Information System (INIS)

    Stöger-Pollach, M.

    2014-01-01

    The present work is a short note on the performance of a conventional transmission electron microscope (TEM) being operated at very low beam energies (below 20 keV). We discuss the high tension stability and resolving power of this uncorrected TEM. We find out that the theoretical lens performance can nearly be achieved in practice. We also demonstrate that electron energy loss spectra can be recorded at these low beam energies with standard equipment. The signal-to-noise ratio is sufficiently good for further data treatment like multiple scattering deconvolution and Kramers–Kronig analysis. - Highlights: • TEM operation at very low beam energies (below 20 keV). • Testing of hardware performance at low beam energies. • EELS spectra recorded with 10 keV electrons

  19. Scattering of a TEM wave from a time varying surface

    Science.gov (United States)

    Elcrat, Alan R.; Harder, T. Mark; Stonebraker, John T.

    1990-03-01

    A solution is given for reflection of a plane wave with TEM polarization from a planar surface with time varying properties. These properties are given in terms of the currents on the surface. The solution is obtained by numerically solving a system of differential-delay equations in the time domain.

  20. TEM-turbulence in stellarators and its optimization

    Science.gov (United States)

    Proll, Josefine H. E.; Helander, Per; Lazerson, Samuel; Mynick, Harry; Xanthopoulos, Pavlos

    2014-10-01

    Quasi-isodynamic stellarators, which are especially optimized for neoclassical transport, have been shown to be resilient towards trapped-electrons modes (TEMs) in large regions of parameter space. In these configurations, all particles have average ``good curvature.'' It was shown analytically that, thanks to this property, particles that bounce faster than the mode in question draw energy from it near marginal stability, so that the ordinary density-gradient-driven TEM has to be stable in the electrostatic and collisionless limit.This has been confirmed in linear flux-tube simulations that were performed with the GENE code. Several magnetic field configurations were compared and it was found that the growth rates of the TEMs drop with increasing degree of quasi-isodynamicity. These findings can be used to optimize stellarators with respect to TEM turbulence by reducing the fraction of trapped particles with bounce averaged ``bad curvature.'' An appropriate proxy function has therefore been designed to be implemented in STELLOPT, a stellarator optimization tool that can now be used to further explore the configuration space of neoclassically optimized stellarators with the aim to extract designs with improved turbulent transport. This work was facilitated by the Max-Planck/Princeton Center for Plasma Physics.

  1. Transmission Electron Microscopy of Minerals and Rocks

    Science.gov (United States)

    McLaren, Alex C.

    1991-04-01

    Of the many techniques that have been applied to the study of crystal defects, none has contributed more to our understanding of their nature and influence on the physical and chemical properties of crystalline materials than transmission electron microscopy (TEM). TEM is now used extensively by an increasing number of earth scientists for direct observation of defect microstructures in minerals and rocks. Transmission Electron Microscopy of Rocks and Minerals is an introduction to the principles of the technique and is the only book to date on the subject written specifically for geologists and mineralogists. The first part of the book deals with the essential physics of the transmission electron microscope and presents the basic theoretical background required for the interpretation of images and electron diffraction patterns. The final chapters are concerned with specific applications of TEM in mineralogy and deal with such topics as planar defects, intergrowths, radiation-induced defects, dislocations and deformation-induced microstructures. The examples cover a wide range of rock-forming minerals from crustal rocks to those in the lower mantle, and also take into account the role of defects in important mineralogical and geological processes.

  2. TEM Microstructure and Chemical Composition of Transition Zone Between Steel Tube and An Inconel 625 Weld Overlay Coating Produced by CMT Method

    Directory of Open Access Journals (Sweden)

    Rozmus-Górnikowska M.

    2017-06-01

    Full Text Available The aim of this work was to investigate the microstructure and chemical composition of the transition zone between 16Mo3 steel and Inconel 625 weld overlay coating produced by the Cold Metal Transfer (CMT method. Investigations were primarily carried out through transmission electron microscopy (TEM on thin foils prepared by FIB (Focus Ion Beam.

  3. MT3FT-15OR0204122: Report on the acquisition and installation of FEI Talos F200X S/TEM

    Energy Technology Data Exchange (ETDEWEB)

    Parish, Chad M. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2015-09-01

    This document describes the installation, performance, and early results from the FCRD-funded acquisition of a new advanced analytical scanning / transmission electron microscopy (S/TEM) at the Oak Ridge National Laboratory Low Activation Materials Development and Analysis (LAMDA) facility.

  4. Microsphere imaging with confocal microscopy and two photon microscopy

    International Nuclear Information System (INIS)

    Chun, Hyung Su; An, Kyung Won; Lee, Jai Hyung

    2002-01-01

    We have acquired images of polystyrene and fused-silica microsphere by using conventional optical microscopy, confocal microscopy and two-photon microscopy, and performed comparative analysis of these images. Different from conventional optical microscopy, confocal and two-photon microscopy had good optical sectioning capability. In addition, confocal microscopy and two-photon microscopy had better lateral resolution than conventional optical microscopy. These results are attributed to confocality and nonlinearity of confocal microscopy and two photon microscopy, respectively.

  5. Collaboration at the Nanoscale: Exploring Viral Genetics with Electron Microscopy

    Science.gov (United States)

    Duboise, S. Monroe; Moulton, Karen D.; Jamison, Jennifer L.

    2009-01-01

    The Maine Science Corps is a project sponsored by the National Science Foundation's (NSF) Graduate Teaching Fellows in K-12 Education (GK-12 ) program. Through this program, the University of Southern Maine's (USM) virology and transmission electron microscopy (TEM) research group provides high school teachers and students in rural areas with…

  6. Investigation of C3 S hydration mechanism by transmission electron microscope (TEM) with integrated Super-XTM EDS system.

    Science.gov (United States)

    Sakalli, Y; Trettin, R

    2017-07-01

    Tricalciumsilicate (C 3 S, Alite) is the major component of the Portland cement clinker. Hydration of Alite is decisive in influencing the properties of the resulting material. This is due to its high content in cement. The mechanism of the hydration of C 3 S is very complicated and not yet fully understood. There are different models describing the hydration of C 3 S in various ways. In this work for a better understanding of hydration mechanism, the hydrated C 3 S was investigated by using the transmission electron microscope (TEM) and for the first time, the samples for the investigations were prepared by using of focused ion beam from sintered pellets of C 3 S. Also, an FEI Talos F200x with an integrated Super-X EDS system was used for the investigations. FEI Talos F200X combines outstanding high-resolution S/TEM and TEM imaging with energy dispersive X-ray spectroscopy signal detection, and 3D chemical characterization with compositional mapping. TEM is a very powerful tool for material science. A high energy beam of electrons passes through a very thin sample, and the interactions between the electrons and the atoms can be used to observe the structure of the material and other features in the structure. TEM can be used to study the growth of layers and their composition. TEM produces high-resolution, two-dimensional images and will be used for a wide range of educational, science and industry applications. Chemical analysis can also be performed. The purpose of these investigations was to get the information about the composition of the C-S-H phases and some details of the nanostructure of the C-S-H phases. © 2017 The Authors Journal of Microscopy © 2017 Royal Microscopical Society.

  7. Edge-melting: nanoscale key-mechanism to explain nanoparticle formation from heated TEM grids

    Energy Technology Data Exchange (ETDEWEB)

    Cesaria, Maura, E-mail: maura.cesaria@le.infn.it [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, 73100 Lecce (Italy); Taurino, Antonietta; Catalano, Massimo [Institute for Microelectronics and Microsystems, IMM-CNR, Via Monteroni, 73100 Lecce (Italy); Caricato, Anna Paola; Martino, Maurizio [Department of Mathematics and Physics “E. De Giorgi”, University of Salento, Via Arnesano, 73100 Lecce (Italy)

    2016-03-01

    Graphical abstract: - Highlights: • Nanoparticle formation from metal grids explained by edge melting as key mechanism. • The inconsistency of bulk phenomenology invoking the vapor pressure is discussed. • Surface-melting and size-dependent evaporation are questioned as unsatisfactory. • Edge-melting: edges, corners, facets invoked as highly thermally unstable surfaces. • The polycrystalline nature of the really occurring metal grids is accounted for. - Abstract: In this study, we examine at both experimental and fundamental levels, the experimental evidence of nanoparticle formation in transmission electron microscopy (TEM) metal grids annealed at temperatures lower than the melting point of the corresponding metal bulk material. Our experimental investigation considers the most thermally unstable TEM grids (i.e. Cu-grids) and inspects the possible sources and mechanisms of contamination of thin films, conventionally deposited on carbon-coated Cu-grids. The investigations are supported by morphological–compositional analyses performed in different regions of the TEM sample. Then, a general model is formulated and discussed in order to explain the grid thermal instability, based on the critical role of edge-melting (i.e. melting initiated at edges and corners of the grid bars), the enhanced rate of evaporation from a liquid surface and the polycristallinity of the grid bars. Hence, we totally disregard conventional arguments such as bulk evaporation and metal vapor pressure and, in order to emphasize and clarify the alternative point of view of our model, we also overview the nano-scale melting phenomenology relevant to our discussion and survey the discrepancies reported in the literature.

  8. Low-pressure Environmental TEM (ETEM) studies of Au assisted MgO nanorod growth

    DEFF Research Database (Denmark)

    Duchstein, Linus Daniel Leonhard; Damsgaard, Christian Danvad; Hansen, Thomas Willum

    2012-01-01

    where they become inactive for CO oxidation. Here, we present an environmental transmission electron microscopy (ETEM) study of shape changes of Au nanoparticles supported on MgO in a controlled gas atmosphere, in order to elucidate the mobility of surface species and the configuration of the Au...... and interface structure of supported nanoparticles in a controlled environment [7]. This allows for a deeper understanding of the dynamic response of the surface and interface to changes in gas composition, pressure and temperature. Additionally, an Ultra High Vacuum (UHV) TEM has been used in order to have...... a higher degree of control of the initial state and probe the low-pressure regime. This combination is a powerful toolbox for charactering the behavior of the mobility of atomic species at the MgO surface leading to the formation of nanorods. Figure 1 shows Au particles on MgO cubes being irradiated...

  9. TEM study of radiation induced defects in baffle-former-barrel assembly from decommissioned NPP Greifswald

    International Nuclear Information System (INIS)

    Srba, O.; Michalicka, J.; Keilova, E.; Kocik, K.

    2013-06-01

    A complex transmission electron microscopy (TEM) study of reactor vessel internal (RVI) materials from the baffle-former-barrel assembly from NPP Greifswald (VVER 440), Unit 1 decommissioned after 15 service cycles has been undertaken. All parts of the baffle-former-barrel assembly are made from Ti-stabilized austenitic stainless steel 08Ch18N10T. The materials were exposed to different dose of neutron radiation (2.4 - 11.4 dpa) at temperatures 267 - 398 deg. C depending on position in the core. Three types of radiation induced defects were identified and quantified, namely: dislocations, cavities (voids) and fine-scaled precipitated particles of Ni-Si rich phases. Black-dot type defects were observed too. Operation conditions are around ≅ 300 deg. C that is why we have observed defect typical for both low and high regions of irradiation temperatures. (authors)

  10. TEM and XANES study of MOVPE grown InAIN layers with different indium content

    International Nuclear Information System (INIS)

    Kret, S; Wolska, A; Klepka, M T; Letrouit, A; Ivaldi, F; Szczepańska, A; Carlin, J-F; Kaufmann, N A K; Grandjean, N

    2011-01-01

    We present structure and spatially resolved composition studies by TEM (Transmission Electron Microscopy) and XANES (X-ray Absorption Near Edge Structure) of InAIN MOVPE (Metal-Organic Vapor Phase Epitaxy) epilayers containing 16-27 at% of indium. Investigations of the In L 3 edge by synchrotron radiation absorption show a significant change of the post-edge structure depending on the indium content. We attribute this to the solubility limit and phase separation in this system. Our measurements suggest that the critical composition is 18% for our growth conditions. HRTEM cross-sectional and EDX investigations confirm such phase separation as well as the changing of the structure from 2D growth to columnar like growth for the sample with the highest indium content.

  11. 2D Inversion of Transient Electromagnetic Method (TEM)

    Science.gov (United States)

    Bortolozo, Cassiano Antonio; Luís Porsani, Jorge; Acácio Monteiro dos Santos, Fernando

    2017-04-01

    A new methodology was developed for 2D inversion of Transient Electromagnetic Method (TEM). The methodology consists in the elaboration of a set of routines in Matlab code for modeling and inversion of TEM data and the determination of the most efficient field array for the problem. In this research, the 2D TEM modeling uses the finite differences discretization. To solve the inversion problem, were applied an algorithm based on Marquardt technique, also known as Ridge Regression. The algorithm is stable and efficient and it is widely used in geoelectrical inversion problems. The main advantage of 1D survey is the rapid data acquisition in a large area, but in regions with two-dimensional structures or that need more details, is essential to use two-dimensional interpretation methodologies. For an efficient field acquisition we used in an innovative form the fixed-loop array, with a square transmitter loop (200m x 200m) and 25m spacing between the sounding points. The TEM surveys were conducted only inside the transmitter loop, in order to not deal with negative apparent resistivity values. Although it is possible to model the negative values, it makes the inversion convergence more difficult. Therefore the methodology described above has been developed in order to achieve maximum optimization of data acquisition. Since it is necessary only one transmitter loop disposition in the surface for each series of soundings inside the loop. The algorithms were tested with synthetic data and the results were essential to the interpretation of the results with real data and will be useful in future situations. With the inversion of the real data acquired over the Paraná Sedimentary Basin (PSB) was successful realized a 2D TEM inversion. The results indicate a robust geoelectrical characterization for the sedimentary and crystalline aquifers in the PSB. Therefore, using a new and relevant approach for 2D TEM inversion, this research effectively contributed to map the most

  12. Electron microscopy of surfaces

    International Nuclear Information System (INIS)

    Venables, J.A.

    1981-01-01

    Electron beam techniques used to study clean surfaces and surface processes on a microscopic scale are reviewed. Recent experimental examples and possible future developments are discussed. Special emphasis is given to (i) transmission diffraction and microscopy techniques, including atomic imaging; (ii) Auger microscopy on bulk and thin film samples; (iii) secondary electron microscopy, especially low energy secondaries for work-function imaging and photoelectron imaging; and (iv) reflection electron microscopy and diffraction. (orig.)

  13. Transmission Electron Microscopy and Diffractometry of Materials

    CERN Document Server

    Fultz, Brent

    2013-01-01

    This book explains concepts of transmission electron microscopy (TEM) and x-ray diffractometry (XRD) that are important for the characterization of materials. The fourth edition adds important new techniques of TEM such as electron tomography, nanobeam diffraction, and geometric phase analysis. A new chapter on neutron scattering completes the trio of x-ray, electron and neutron diffraction. All chapters were updated and revised for clarity. The book explains the fundamentals of how waves and wavefunctions interact with atoms in solids, and the similarities and differences of using x-rays, electrons, or neutrons for diffraction measurements. Diffraction effects of crystalline order, defects, and disorder in materials are explained in detail. Both practical and theoretical issues are covered. The book can be used in an introductory-level or advanced-level course, since sections are identified by difficulty. Each chapter includes a set of problems to illustrate principles, and the extensive Appendix includes la...

  14. XRD, TEM, and thermal analysis of Arizona Ca-montmorillonites modified with didodecyldimethylammonium bromide.

    Science.gov (United States)

    Sun, Zhiming; Park, Yuri; Zheng, Shuilin; Ayoko, Godwin A; Frost, Ray L

    2013-10-15

    An Arizona SAz-2 calcium montmorillonite was modified by a typical dialkyl cationic surfactant (didodecyldimethylammonium bromide, abbreviated to DDDMA) through direct ion exchange. The obtained organoclays were characterized by X-ray diffraction (XRD), high-resolution transmission electron microscopy (HR-TEM), high-resolution thermogravimetric analysis (HR-TG), and infrared emission spectroscopy (IES). The intercalation of surfactants greatly increased the basal spacing of the interlayers and the conformation arrangement of the loaded surfactant were assessed based on the XRD and TEM measurements. This work shows that the dialkyl surfactant can be directly intercalated into the montmorillonite without first undergoing Na(+) exchange. Moreover, the thermal stability of organoclays and the different arrangements of the surfactant molecules intercalated in the SAz-2 Ca-montmorillonite were determined by a combination of TG and IES techniques. The detailed conformational ordering of different intercalated surfactants under different conditions was also studied. The surfactant molecule DDDMA has proved to be thermally stable even at 400°C which indicates that the prepared organoclay is stable to significantly high temperatures. This study offers new insights into the structure and thermal stabilities of SAz-2 Ca-montmorillonite modified with DDDMA. The experimental results also confirm the potential applications of organic SAz-2 Ca-montmorillonites as adsorbents and polymer-clay nanocomposites. Copyright © 2013 Elsevier Inc. All rights reserved.

  15. Chromatic Aberration Correction for Atomic Resolution TEM Imaging from 20 to 80 kV.

    Science.gov (United States)

    Linck, Martin; Hartel, Peter; Uhlemann, Stephan; Kahl, Frank; Müller, Heiko; Zach, Joachim; Haider, Max; Niestadt, Marcel; Bischoff, Maarten; Biskupek, Johannes; Lee, Zhongbo; Lehnert, Tibor; Börrnert, Felix; Rose, Harald; Kaiser, Ute

    2016-08-12

    Atomic resolution in transmission electron microscopy of thin and light-atom materials requires a rigorous reduction of the beam energy to reduce knockon damage. However, at the same time, the chromatic aberration deteriorates the resolution of the TEM image dramatically. Within the framework of the SALVE project, we introduce a newly developed C_{c}/C_{s} corrector that is capable of correcting both the chromatic and the spherical aberration in the range of accelerating voltages from 20 to 80 kV. The corrector allows correcting axial aberrations up to fifth order as well as the dominating off-axial aberrations. Over the entire voltage range, optimum phase-contrast imaging conditions for weak signals from light atoms can be adjusted for an optical aperture of at least 55 mrad. The information transfer within this aperture is no longer limited by chromatic aberrations. We demonstrate the performance of the microscope using the examples of 30 kV phase-contrast TEM images of graphene and molybdenum disulfide, showing unprecedented contrast and resolution that matches image calculations.

  16. TEM Study of High-Temperature Precipitation of Delta Phase in Inconel 718 Alloy

    Directory of Open Access Journals (Sweden)

    Moukrane Dehmas

    2011-01-01

    Full Text Available Inconel 718 is widely used because of its ability to retain strength at up to 650∘C for long periods of time through coherent metastable  Ni3Nb precipitation associated with a smaller volume fraction of  Ni3Al precipitates. At very long ageing times at service temperature,  decomposes to the stable Ni3Nb phase. This latter phase is also present above the  solvus and is used for grain control during forging of alloy 718. While most works available on precipitation have been performed at temperatures below the  solvus, it appeared of interest to also investigate the case where phase precipitates directly from the fcc matrix free of  precipitates. This was studied by X-ray diffraction and transmission electron microscopy (TEM. TEM observations confirmed the presence of rotation-ordered domains in plates, and some unexpected contrast could be explained by double diffraction due to overlapping phases.

  17. The experimental electron mean-free-path in Si under typical (S)TEM conditions

    International Nuclear Information System (INIS)

    Potapov, P.L.

    2014-01-01

    The electron mean-free-path in Si was measured by EELS using the test structure with the certified dimensions as a calibration standard. In a good agreement with the previous CBED measurements, the mean-free-path is 150 nm for 200 keV and 179 nm for 300 keV energy of primary electrons at large collection angles. These values are accurately predicted by the model of Iakoubovskii et al. while the model of Malis et al. incorporated in common microscopy software underestimates the mean-free-path by 15% at least. Correspondingly, the thickness of TEM samples reported in many studies of the Si-based materials last decades might be noticeably underestimated. - Highlights: • The electron inelastic mean-free-path in Si is measured for the typical (S)TEM conditions. • These reference values allow for accurate determination of the lamella thickness by EELS. • The theoretical model by Malis et al. underestimates the mean-free-path values

  18. TEM investigation of irradiation damage in single crystal CeO2

    International Nuclear Information System (INIS)

    Ye Bei; Kirk, Mark A.; Chen, Weiying; Oaks, Aaron; Rest, Jeffery; Yacout, Abdellatif; Stubbins, James F.

    2011-01-01

    In order to understand the evolution of radiation damage in oxide nuclear fuel, 150-1000 keV Kr ions were implanted into single crystal CeO 2 , as a simulation of fluorite ceramic UO 2 , while in situ transmission electron microscopy (TEM) observations were carried out. Two characteristic defect structures were investigated: dislocation/dislocation loops and nano-size gas bubbles. The growth behavior of defect clusters induced by 1 MeV Kr ions up to doses of 5 x 10 15 ions/cm 2 were followed at 600 deg. C and 800 deg. C. TEM micrographs clearly show the development of defect structures: nucleation of dislocation loops, transformation to extended dislocation lines, and the formation of tangled dislocation networks. The difference in dislocation growth rates at 600 deg. C and 800 deg. C revealed the important role which Ce-vacancies play in the loop formation process. Bubble formation, studied through 150 keV Kr implantations at room temperature and 600 deg. C, might be influenced by either the mobility of metal-vacancies correlated with at threshold temperature or the limitation of gas solubility as a function of temperature.

  19. FIB and TEM studies of damage mechanisms in DLC coatings sliding against aluminum

    International Nuclear Information System (INIS)

    Meng-Burany, X.; Alpas, A.T.

    2007-01-01

    Material transfer and adhesion phenomena during sliding contact of non-hydrogenated diamond like carbon (DLC) coatings against an aluminum-silicon (319 Al) counterface tested in vacuum were studied using TEM investigations of the cross-sectional microstructures of the wear tracks. Site-specific focused ion beam (FIB) lift-out method was used to prepare the sections at the precise locations where aluminum pieces were adhered to the DLC surface. The dense amorphous structure of DLC coatings with nanocrystalline graphite platelets is confirmed by the high-resolution transmission electron microscopy. The focused ion channeling contrast images obtained from the cross-sections of the wear track indicated that in some sections of DLC coatings considerable wear was inflicted by aluminum, reducing the coating thickness. The aluminum that was transferred on the DLC coatings' contact surfaces consisted of nanocrystalline grains of less than 100 nm. TEM examination of the contact surface of the 319 Al pin has revealed that the initial aluminum grain size was also reduced to the nanocrystalline scale and this was accompanied with a hardness increase. These observations revealed that local severe plastic deformation accompanied the aluminum adhesion process to DLC coating surfaces

  20. ERDA, RBS, TEM and SEM characterization of microstructural evolution in helium-implanted Hastelloy N alloy

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Jie [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049 (China); Bao, Liangman [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Huang, Hefei, E-mail: huanghefei@sinap.ac.cn [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Li, Yan, E-mail: liyan@sinap.ac.cn [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Lei, Qiantao [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Institute of Modern Physics, Fudan University, Shanghai 200433 (China); Deng, Qi [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Liu, Zhe; Yang, Guo [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); School of Physical Sciences, University of Chinese Academy of Sciences, Beijing 100049 (China); Shi, Liqun [Institute of Modern Physics, Fudan University, Shanghai 200433 (China)

    2017-05-15

    Hastelloy N alloy was implanted with 30 keV, 5 × 10{sup 16} ions/cm{sup 2} helium ions at room temperature, and subsequent annealed at 600 °C for 1 h and further annealed at 850 °C for 5 h in vacuum. Using elastic recoil detection analysis (ERDA) and transmission electron microscopy (TEM), the depth profiles of helium concentration and helium bubbles in helium-implanted Hastelloy N alloy were investigated, respectively. The diffusion of helium and molybdenum elements to surface occurred during the vacuum annealing at 850 °C (5 h). It was also observed that bubbles in molybdenum-enriched region were much larger in size than those in deeper region. In addition, it is worth noting that plenty of nano-holes can be observed on the surface of helium-implanted sample after high temperature annealing by scanning electron microscope (SEM). This observation provides the evidence for the occurrence of helium release, which can be also inferred from the results of ERDA and TEM analysis.

  1. Fabrication of thin TEM sample of ionic liquid for high-resolution ELNES measurements

    Energy Technology Data Exchange (ETDEWEB)

    Miyata, Tomohiro, E-mail: tomo-m@iis.u-tokyo.ac.jp; Mizoguchi, Teruyasu, E-mail: teru@iis.u-tokyo.ac.jp

    2017-07-15

    Investigation of the local structure, ionic and molecular behavior, and chemical reactions at high spatial resolutions in liquids has become increasingly important. Improvements in these areas help to develop efficient batteries and improve organic syntheses. Transmission electron microscopy (TEM) and scanning-TEM (STEM) have excellent spatial resolution, and the electron energy-loss near edge structure (ELNES) measured by the accompanied electron energy-loss spectroscopy (EELS) is effective to analyze the liquid local structure owing to reflecting the electronic density of states. In this study, we fabricate a liquid-layer-only sample with thickness of single to tens nanometers using an ionic liquid. Because the liquid film has a thickness much less than the inelastic mean free path (IMFP) of the electron beam, the fine structure of the C-K edge electron energy loss near edge structure (ELNES) can be measured with sufficient resolution to allow meaningful analysis. The ELNES spectrum from the thin liquid film has been interpreted using first principles ELNES calculations. - Highlights: • A fabrication method of thin liquid film samples for STEM-EELS observations is proposed. • The thickness of the fabricated thin liquid film is about 10 nm. • An ELNES is measured from the thin liquid with a high energy resolution. • The peaks of the ELNES are interpreted using first principles calculations.

  2. TEM characterization of corrosion products formed on a SS-15ZR alloy

    International Nuclear Information System (INIS)

    Luo, J. S.; Abraham, D. P.

    2000-01-01

    The corrosion products formed on a stainless steel-15Zr (SS-15Zr) alloy have been characterized by transmission electron microscopy (TEM) and energy dispersive x-ray spectroscopy (EDS). Examination of alloy particles that were immersed in 90 C deionized water for two years revealed that different corrosion products were formed on the stainless steel and intermetallic phases. Two corrosion products were identified on an austenite particle: trevorite (NiFe 2 O 4 ) in the layer close to the metal and maghemite (Fe 2 O 3 ) in the outer layer. The corrosion layer formed on the intermetallic was uniform, adherent, and amorphous. The EDS analysis indicated that the layer was enriched in zirconium when compared with the intermetallic composition. High-resolution TEM images of the intermetallic-corrosion layer interface show an interlocking metal-oxide interface which may explain the relatively strong adherence of the corrosion layer to the intermetallic surface. These results will be used to evaluate corrosion mechanisms and predict long-term corrosion behavior of the alloy waste form

  3. In-situ TEM observation of nano-void formation in UO2 under irradiation

    Science.gov (United States)

    Sabathier, C.; Martin, G.; Michel, A.; Carlot, G.; Maillard, S.; Bachelet, C.; Fortuna, F.; Kaitasov, O.; Oliviero, E.; Garcia, P.

    2014-05-01

    Transmission electron microscopy (TEM) observations of UO2 polycrystals irradiated in situ with 4 MeV Au ions were performed at room temperature (RT) to better understand the mechanisms of cavity and ultimately fission products nucleation in UO2. Experiments were carried out at the JANNuS Orsay facility that enables in situ ion irradiations inside the microscope to be carried out. The majority of 4 MeV gold ions were transmitted through the thin foil, and the induced radiation defects were investigated by TEM. Observations showed that nano-void formation occurs at ambient temperature in UO2 thin foils irradiated with energetic heavy ions under an essentially nuclear energy loss regime. The diameter and density of nano-objects were measured as a function of the gold irradiation dose at RT. A previous paper has also revealed a similar nano-object population after a Xe implantation performed at 390 keV at 870 K. The nano-object density was modelled using simple concepts derived from Classical Molecular Dynamics simulations. The results are in good agreement, which suggests a mechanism of heterogeneous nucleation induced by energetic cascade overlaps. This indicates that nano-void formation mechanism is controlled by radiation damage. Such nanovoids are likely to act as sinks for mobile fission products during reactor operation.

  4. Dictionary of Microscopy

    Science.gov (United States)

    Heath, Julian

    2005-10-01

    The past decade has seen huge advances in the application of microscopy in all areas of science. This welcome development in microscopy has been paralleled by an expansion of the vocabulary of technical terms used in microscopy: terms have been coined for new instruments and techniques and, as microscopes reach even higher resolution, the use of terms that relate to the optical and physical principles underpinning microscopy is now commonplace. The Dictionary of Microscopy was compiled to meet this challenge and provides concise definitions of over 2,500 terms used in the fields of light microscopy, electron microscopy, scanning probe microscopy, x-ray microscopy and related techniques. Written by Dr Julian P. Heath, Editor of Microscopy and Analysis, the dictionary is intended to provide easy navigation through the microscopy terminology and to be a first point of reference for definitions of new and established terms. The Dictionary of Microscopy is an essential, accessible resource for: students who are new to the field and are learning about microscopes equipment purchasers who want an explanation of the terms used in manufacturers' literature scientists who are considering using a new microscopical technique experienced microscopists as an aide mémoire or quick source of reference librarians, the press and marketing personnel who require definitions for technical reports.

  5. High resolution, high speed ultrahigh vacuum microscopy

    International Nuclear Information System (INIS)

    Poppa, Helmut

    2004-01-01

    The history and future of transmission electron microscopy (TEM) is discussed as it refers to the eventual development of instruments and techniques applicable to the real time in situ investigation of surface processes with high resolution. To reach this objective, it was necessary to transform conventional high resolution instruments so that an ultrahigh vacuum (UHV) environment at the sample site was created, that access to the sample by various in situ sample modification procedures was provided, and that in situ sample exchanges with other integrated surface analytical systems became possible. Furthermore, high resolution image acquisition systems had to be developed to take advantage of the high speed imaging capabilities of projection imaging microscopes. These changes to conventional electron microscopy and its uses were slowly realized in a few international laboratories over a period of almost 40 years by a relatively small number of researchers crucially interested in advancing the state of the art of electron microscopy and its applications to diverse areas of interest; often concentrating on the nucleation, growth, and properties of thin films on well defined material surfaces. A part of this review is dedicated to the recognition of the major contributions to surface and thin film science by these pioneers. Finally, some of the important current developments in aberration corrected electron optics and eventual adaptations to in situ UHV microscopy are discussed. As a result of all the path breaking developments that have led to today's highly sophisticated UHV-TEM systems, integrated fundamental studies are now possible that combine many traditional surface science approaches. Combined investigations to date have involved in situ and ex situ surface microscopies such as scanning tunneling microscopy/atomic force microscopy, scanning Auger microscopy, and photoemission electron microscopy, and area-integrating techniques such as x-ray photoelectron

  6. A convenient method for X-ray analysis in TEM that measures mass thickness and composition

    Science.gov (United States)

    Statham, P.; Sagar, J.; Holland, J.; Pinard, P.; Lozano-Perez, S.

    2018-01-01

    We consider a new approach for quantitative analysis in transmission electron microscopy (TEM) that offers the same convenience as single-standard quantitative analysis in scanning electron microscopy (SEM). Instead of a bulk standard, a thin film with known mass thickness is used as a reference. The procedure involves recording an X-ray spectrum from the reference film for each session of acquisitions on real specimens. There is no need to measure the beam current; the current only needs to be stable for the duration of the session. A new reference standard with a large (1 mm x 1 mm) area of uniform thickness of 100 nm silicon nitride is used to reveal regions of X-ray detector occlusion that would give misleading results for any X-ray method that measures thickness. Unlike previous methods, the new X-ray method does not require an accurate beam current monitor but delivers equivalent accuracy in mass thickness measurement. Quantitative compositional results are also automatically corrected for specimen self-absorption. The new method is tested using a wedge specimen of Inconel 600 that is used to calibrate the high angle angular dark field (HAADF) signal to provide a thickness reference and results are compared with electron energy-loss spectrometry (EELS) measurements. For the new X-ray method, element composition results are consistent with the expected composition for the alloy and the mass thickness measurement is shown to provide an accurate alternative to EELS for thickness determination in TEM without the uncertainty associated with mean free path estimates.

  7. A developed wedge fixtures assisted high precision TEM samples pre-thinning method: Towards the batch lamella preparation

    Directory of Open Access Journals (Sweden)

    Dandan Wang

    2017-04-01

    Full Text Available Ion milling, wedge cutting or polishing, and focused ion beam (FIB milling are widely-used techniques for the transmission electron microscope (TEM sample preparation. Especially, the FIB milling provides a site-specific analysis, deposition, and ablation of materials in the micrometer and nanometer scale. However, the cost of FIB tools has been always a significant concern. Since it is inevitable to use the FIB technique, the improvement of efficiency is a key point. Traditional TEM sample preparation with FIB was routinely implemented on a single sample each time. Aiming at cost efficiency, a new pre-thinning technique for batch sample preparation was developed in this paper. The present proposal combines the sample preparation techniques with multi-samples thinning, cross-section scanning electron microscopy (SEM, wedge cutting, FIB and other sample pre-thinning techniques. The new pre-thinning technique is to prepare an edge TEM sample on a grinding and polishing fixture with a slant surface. The thickness of the wedges sample can be measured to 1∼2 μm under optical microscope. Therefore, this fixture is superior to the traditional optical method of estimating the membrane thickness. Moreover, by utilizing a multi-sample holding fixture, more samples can be pre-thinned simultaneously, which significantly improved the productivity of TEM sample preparation.

  8. Application of transmission electron microscopy for microstructural characterization of perfluoropentacene thin films

    International Nuclear Information System (INIS)

    Haas, Benedikt; Beyer, Andreas; Witte, Wiebke; Breuer, Tobias; Witte, Gregor; Volz, Kerstin

    2011-01-01

    The crystalline structure and orientation of perfluoropentacene (C 22 F 14 , PFP) fibers formed upon thin-film deposition onto SiO 2 substrates have been studied by means of transmission electron microscopy (TEM), atomic force microscopy (AFM), and x-ray diffraction. The synopsis of TEM micrographs and diffraction patterns enhances the understanding of local crystal orientation on small length scales. The relationship of the PFP fiber morphology with the crystalline arrangement of PFP molecules within single fibers was established using this technique. Radiation damage, which is a critical problem for TEM investigations of organic materials, is described and the sample morphology after TEM investigations is correlated with AFM measurements of samples previously examined by TEM.

  9. Electron Microscopy of Ebola Virus-Infected Cells.

    Science.gov (United States)

    Noda, Takeshi

    2017-01-01

    Ebola virus (EBOV) replicates in host cells, where both viral and cellular components show morphological changes during the process of viral replication from entry to budding. These steps in the replication cycle can be studied using electron microscopy (EM), including transmission electron microscopy (TEM) and scanning electron microscopy (SEM), which is one of the most useful methods for visualizing EBOV particles and EBOV-infected cells at the ultrastructural level. This chapter describes conventional methods for EM sample preparation of cultured cells infected with EBOV.

  10. Characterization of some biological specimens using TEM and SEM

    Science.gov (United States)

    Ghosh, Nabarun; Smith, Don W.

    2009-05-01

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

  11. In situ TEM observation of solid-gas reactions

    International Nuclear Information System (INIS)

    Kishita, K; Kamino, T; Watabe, A; Kuroda, K; Saka, H

    2008-01-01

    Under a gaseous atmosphere at high temperatures, almost all the materials (metal, catalysts, etc.) change their structures and properties. For the research and development of materials, it is of vital importance to clarify mechanisms of solid-gas and liquid-gas reactions. Recently an in situ TEM system combined with an environmental holder, which has a gas injection nozzle close to a specimen-heating element, has been developed. The gas injection nozzle permits gas to flow around the specimens sitting on the heating element made of a fine W filament. The newly developed in situ TEM has a differential pumping system; therefore, the pressure in the specimen chamber is maintained in the range of higher than 1 Pa, while the pressure in the electron gun chamber can be kept in the range of 10 -5 Pa. This system was applied to in situ observation of chemical reactions of metals with gases: Observation of oxidation and reduction under a gas pressure ranging from 10 -5 Pa to 1 Pa at high temperatures (room temperature to ∼1473 K) were successfully carried out on pure metal and rare metal catalysts at near-atomic resolution. This in situ environmental TEM system is promising for clarifying mechanisms of many solid-gas and liquid-gas reactions that take place at high temperatures under a gas atmosphere.

  12. A new method to characterize dopant profiles in NMOSFETs using conventional transmission electron microscopy

    International Nuclear Information System (INIS)

    Kawamura, Kazuo; Ikeda, Kazuto; Terauchi, Masami

    2004-01-01

    We have developed a new method using conventional transmission electron microscopy (TEM) to obtain two dimensional dopant profiles in silicon and applied it to 40 nm-gate-length N + /p metal oxide semiconductor field effect transistors (MOSFETs). The results are consistent with those of selective-chemically etched samples observed by TEM. This method, using focused ion beam (FIB) sample preparation and conventional TEM, has the great advantage of simple sample preparation and high spatial resolution compared to other characterization methods, such as atomic capacitance microscopy, spreading resistance microscopy, and TEM combined with selective chemical etching. This indicates that this method can be applicable to the analysis of FETs at the 65 nm or smaller node

  13. Atomic force microscopy applied to study macromolecular content of embedded biological material

    Energy Technology Data Exchange (ETDEWEB)

    Matsko, Nadejda B. [Electron Microscopy Centre, Institute of Applied Physics, HPM C 15.1, ETH-Hoenggerberg, CH-8093, Zurich (Switzerland)]. E-mail: matsko@iap.phys.ethz.ch

    2007-02-15

    We demonstrate that atomic force microscopy represents a powerful tool for the estimation of structural preservation of biological samples embedded in epoxy resin, in terms of their macromolecular distribution and architecture. The comparison of atomic force microscopy (AFM) and transmission electron microscopy (TEM) images of a biosample (Caenorhabditis elegans) prepared following to different types of freeze-substitution protocols (conventional OsO{sub 4} fixation, epoxy fixation) led to the conclusion that high TEM stainability of the sample results from a low macromolecular density of the cellular matrix. We propose a novel procedure aimed to obtain AFM and TEM images of the same particular organelle, which strongly facilitates AFM image interpretation and reveals new ultrastructural aspects (mainly protein arrangement) of a biosample in addition to TEM data.

  14. How TEM Projection Artifacts Distort Microstructure Measurements: A Case Study in a 9 pct Cr-Mo-V Steel

    Science.gov (United States)

    Monsegue, Niven; Reynolds, William T.; Hawk, Jeffrey A.; Murayama, Mitsuhiro

    2014-08-01

    Morphological data obtained from two-dimensional (2D) and three-dimensional (3D) transmission electron microscopy (TEM) observations were compared to assess the effects of TEM projection errors for submicron-size precipitates. The microstructure consisted of M23C6 carbides in a 9 pct Cr-Mo-V heat resistant steel before and after exposure to creep conditions. Measurements obtained from about 800 carbides demonstrate that particle size and spacing estimates made from 2D observations overestimate the more accurate values obtained from 3D reconstructions. The 3D analysis also revealed the M23C6 precipitates lengthen anisotropically along lath boundary planes, suggesting that coarsening during the early stage of creep in this alloy system is governed by grain boundary diffusion.

  15. Objective function analysis for electric soundings (VES), transient electromagnetic soundings (TEM) and joint inversion VES/TEM

    Science.gov (United States)

    Bortolozo, Cassiano Antonio; Bokhonok, Oleg; Porsani, Jorge Luís; Monteiro dos Santos, Fernando Acácio; Diogo, Liliana Alcazar; Slob, Evert

    2017-11-01

    Ambiguities in geophysical inversion results are always present. How these ambiguities appear in most cases open to interpretation. It is interesting to investigate ambiguities with regard to the parameters of the models under study. Residual Function Dispersion Map (RFDM) can be used to differentiate between global ambiguities and local minima in the objective function. We apply RFDM to Vertical Electrical Sounding (VES) and TEM Sounding inversion results. Through topographic analysis of the objective function we evaluate the advantages and limitations of electrical sounding data compared with TEM sounding data, and the benefits of joint inversion in comparison with the individual methods. The RFDM analysis proved to be a very interesting tool for understanding the joint inversion method of VES/TEM. Also the advantage of the applicability of the RFDM analyses in real data is explored in this paper to demonstrate not only how the objective function of real data behaves but the applicability of the RFDM approach in real cases. With the analysis of the results, it is possible to understand how the joint inversion can reduce the ambiguity of the methods.

  16. SEM and TEM characterization of microstructure of stainless steel composites reinforced with TiB2

    International Nuclear Information System (INIS)

    Sulima, Iwona; Boczkal, Sonia; Jaworska, Lucyna

    2016-01-01

    Steel-8TiB 2 composites were produced by two new sintering techniques, i.e. Spark Plasma Sintering (SPS) and High Pressure-High Temperature (HP-HT) sintering. This study discusses the impact of these sintering methods on the microstructure of steel composites reinforced with TiB 2 particles. Scanning electron microscopy (SEM), wavelength dispersive spectroscopy (WDS), X-ray diffraction, electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) were used to analyze the microstructure evolution in steel matrix composites. The results of microscopic examinations revealed a close relationship between the composite microstructure and the methods and conditions of sintering. Substantial differences were observed in the grain size of materials sintered by HP-HT and SPS. It has been demonstrated that the composites sintered by HP-HT tend to form a chromium-iron-nickel phase in the steel matrix. In contrast, the microstructure of the composites sintered by SPS is characterized by the presence of complex borides and chromium-iron phase. - Highlights: •The steel-8TiB 2 composites were fabricated by Spark Plasma Sintering (SPS) and High Pressure-High Temperature (HP-HT). •Sintering techniques has an important effect on changes in the microstructure of steel-8TiB 2 composites. •New phases of different size and morphology were identified.

  17. A rapid method of reprocessing for electronic microscopy of cut histological in paraffin

    International Nuclear Information System (INIS)

    Hernandez Chavarri, F.; Vargas Montero, M.; Rivera, P.; Carranza, A.

    2000-01-01

    A simple and rapid method is described for re-processing of light microscopy paraffin sections to observe they under transmission electron microscopy (TEM) and scanning electron microscopy (SEM) The paraffin-embedded tissue is sectioned and deparaffinized in toluene; then exposed to osmium vapor under microwave irradiation using a domestic microwave oven. The tissues were embedded in epoxy resin, polymerized and ultrathin sectioned. The method requires a relatively short time (about 30 minutes for TEM and 15 for SEM), and produces a reasonable quality of the ultrastructure for diagnostic purposes. (Author) [es

  18. Effect of interparticle interactions on size determination of zirconia and silica based systems – A comparison of SAXS, DLS, BET, XRD and TEM

    Science.gov (United States)

    Pabisch, Silvia; Feichtenschlager, Bernhard; Kickelbick, Guido; Peterlik, Herwig

    2012-01-01

    The aim of this work is a systematic comparison of size characterisation methods for two completely different model systems of oxide nanoparticles, i.e. amorphous spherical silica and anisotropic facet-shaped crystalline zirconia. Size and/or size distribution were determined in a wide range from 5 to 70 nm using small-angle X-ray scattering (SAXS), dynamic light scattering (DLS), nitrogen sorption (BET), X-ray diffraction (XRD) and transmission electron microscopy (TEM). A nearly perfect coincidence was observed only for SAXS and TEM for both types of particles. For zirconia nanoparticles considerable differences between different measurement methods were observed. PMID:22347721

  19. 'In situ' and 'Post-mortem' TEM study of the super-elastic effect in Cu-Al-Ni shape memory alloys

    International Nuclear Information System (INIS)

    Ibarra, A.; San Juan, J.; Bocanegra, E.H.; Caillard, D.; No, M.L.

    2006-01-01

    An analysis of the microstructure evolution during super-elastic cycling has been performed by transmission electron microscopy (TEM) in order to understand the physical mechanism responsible for the thermo-mechanical properties evolution, as well as the martensitic transformation ageing. Particularly, in this work we have studied the super-elastic effect in Cu-Al-Ni shape memory alloys by 'in situ' TEM experiments. The bright field images and diffraction patterns have allowed us to determine, during the transformation, the kind of nucleated martensite variants and their relative orientations. Finally, we have analysed the super-elastic effect on the dislocation microstructure and on the transformation temperatures

  20. New microscopy for nanoimaging

    CERN Document Server

    Kinjo, Y; Watanabe, M

    2002-01-01

    Two types of new microscopy, namely, X-ray contact microscopy (XRCM) in combination with atomic force microscopy (AFM) and X-ray projection microscopy (XRPM) using synchrotron radiation and zone plate optics were used to image the fine structures of human chromosomes. In the XRCM plus AFM system, location of X-ray images on a photoresist has become far easier than that with our previous method using transmission electron microscopy coupled with the replica method. In addition, the images obtained suggested that the conformation of chromatin fiber differs from the current textbook model regarding the architecture of a eukaryotic chromosome. X-ray images with high contrast of the specimens could be obtained with XRPM. The resolution of each microscopy was about 30 and 200-300 nm for XRCM plus AFM and XRPM, respectively. (author)

  1. Microscopy and Image Analysis.

    Science.gov (United States)

    McNamara, George; Difilippantonio, Michael; Ried, Thomas; Bieber, Frederick R

    2017-07-11

    This unit provides an overview of light microscopy, including objectives, light sources, filters, film, and color photography for fluorescence microscopy and fluorescence in situ hybridization (FISH). We believe there are excellent opportunities for cytogeneticists, pathologists, and other biomedical readers, to take advantage of specimen optical clearing techniques and expansion microscopy-we briefly point to these new opportunities. © 2017 by John Wiley & Sons, Inc. Copyright © 2017 John Wiley & Sons, Inc.

  2. CARS microscopy for imaging

    International Nuclear Information System (INIS)

    Arzumanyan Grigory; Voskanyan Karine

    2013-01-01

    Optical microscopy grows in its importance with the development of modern nanotechnology, biotechnology, methods of diagnostics and treatment of most dangerous diseases for mankind. There are several important goals of optical microscopy for biomedical studies among which the next three may be distinguished: fast imaging with high lateral spatial resolution, 3-D sectioning capability and high contrast for chemical selectivity. To meet these specific requirements, various types of both linear and nonlinear optical microscopy were elaborated. (authors)

  3. Fluorescence (Multiwave) Confocal Microscopy.

    Science.gov (United States)

    Welzel, J; Kästle, Raphaela; Sattler, Elke C

    2016-10-01

    In addition to reflectance confocal microscopy, multiwave confocal microscopes with different laser wavelengths in combination with exogenous fluorophores allow fluorescence mode confocal microscopy in vivo and ex vivo. Fluorescence mode confocal microscopy improves the contrast between the epithelium and the surrounding soft tissue and allows the depiction of certain structures, like epithelial tumors, nerves, and glands. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. A new procedure for making TEM specimens of superconductor devices

    International Nuclear Information System (INIS)

    Huang, Y.; Merkle, K.L.

    1997-04-01

    A new procedure is developed for making TEM specimens of thin film devices. In this procedure the sample is flatly polished to an overall ion-mill-ready thickness so that any point in the 2-D sample pane can be thinned to an electron-transparent thickness by subsequent ion-milling. Using this procedure, small regions of interest can be easily reached in both cross-section and plan-view samples. This is especially useful in device studies. Applications of this procedure to the study of superconductor devices yield good results. This procedure, using commercially available equipment and relatively cheap materials, is simple and easy to realize

  5. Easy process to obtain suspended graphene flakes on TEM grids

    International Nuclear Information System (INIS)

    Gonçalves, Hugo; Fernandes, Joel; Moura, Cacilda; Schellenberg, Peter; Belsley, Michael; Alves, Luís

    2015-01-01

    Much of the ongoing research on graphene requires free-hanging (suspended) graphene to eliminate any influence from underlying substrates. Several methods have been developed for its preparation but they are either very complex or not completely reliable. Here, we describe a simple method for the transfer of graphene single layers from glass or silicon substrates onto TEM grids. The method uses a carrier film for the transfer process. By optimizing the process yields greater than 60% were achieved. The integrity of the transferred films was confirmed using Raman spectroscopy; successful suspension of both mono- and double-layer graphene sheets was obtained. (paper)

  6. In-situ TEM characterization of nanomaterials and devices

    KAUST Repository

    Kim, Moon; Park, Seongyong; Cha, Dong Kyu; Kim, Jiyoung; Floresca, Herman Carlo; Lu, Ning; Wang, Jinguo

    2011-01-01

    Electrical properties of nano size devices were directly measured by TEM. Real time observation of phase transition behavior in PRAM revealed that the volume of the crystalline phase is the main factor in determining cell resistance. In the transistor device, we have identified the doping type and area by measuring the I-V curve at the individual nano contact on the specimen. The evolution of the graphene edge structure was controlled and monitored at and up to 1200°C in-situ. © 2011 IEEE.

  7. TEM observations of HT-9 as-welded weldment microstructures

    International Nuclear Information System (INIS)

    Foulds, J.R.; Lechtenberg, T.A.

    1984-01-01

    TEM studies of different locations in an HT-9 weldment indicated delta-ferrite (delta) occurrence, M 23 C 6 precipitation at delta-martensite interfaces, fine carbide precipitation at prior austenite grain boundaries, and martensite lath and lath packet size to be the distinguishable microstructure features observed. Furthermore, retained austenite films were observed in the weld metal and the HAZ adjacent to the weld metal that reached the highest temperature during joining. The microstructures correlate well with the observed room temperature microhardness except for the fusion boundary in weld metal which exhibited a hardness drop and an unexpected minimum amount of delta-ferrite

  8. Shear Punch Testing of BOR-60 Irradiated TEM Specimens

    Energy Technology Data Exchange (ETDEWEB)

    Saleh, Tarik A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Quintana, Matthew Estevan [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Romero, Tobias J. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-06-13

    As a part of the project “High Fidelity Ion Beam Simulation of High Dose Neutron Irradiation” an Integrated Research Program (IRP) project from the U.S. Department of Energy, Nuclear Energy University Programs (NEUP), TEM geometry samples of ferritic cladding alloys, Ni based super alloys and model alloys were irradiated in the BOR-60 reactor to ~16 dpa at ~370°C and ~400°C. Samples were sent to Los Alamos National Laboratory and subjected to shear punch testing. This report presents the results from this testing.

  9. TEM INVESTIGATIONS OF WC-Co ALLOYS AFTER CREEP EXPERIMENTS

    OpenAIRE

    Lay , S.; Osterstock , F.; Vicens , J.

    1986-01-01

    Carbide tungsten cobalt alloys were deformed in compression or in three point bending in a temperature range 1000-1350°C and in a stress domain 30-1000MPa. In these conditions, the stress exponent n of WC-Co alloys is a function of only the cobalt volumic ratio and tends towards n = 1 for pure carbide. The apparent activation energy is 550 kj mole-1. T.E.M. investigations on pure carbide deformed at 1450°C show an extensive intragranular deformation. Analysis of these defects have been perfor...

  10. In-situ TEM characterization of nanomaterials and devices

    KAUST Repository

    Kim, Moon

    2011-10-01

    Electrical properties of nano size devices were directly measured by TEM. Real time observation of phase transition behavior in PRAM revealed that the volume of the crystalline phase is the main factor in determining cell resistance. In the transistor device, we have identified the doping type and area by measuring the I-V curve at the individual nano contact on the specimen. The evolution of the graphene edge structure was controlled and monitored at and up to 1200°C in-situ. © 2011 IEEE.

  11. Comparative TEM study of bonded silicon/silicon interfaces fabricated by hydrophilic, hydrophobic and UHV wafer bonding

    International Nuclear Information System (INIS)

    Reznicek, A.; Scholz, R.; Senz, S.; Goesele, U.

    2003-01-01

    Wafers of Czochralski-grown silicon were bonded hydrophilically, hydrophobically and in ultrahigh vacuum (UHV) at room temperature. Wafers bonded hydrophilically adhere together by hydrogen bonds, those bonded hydrophobically by van der Waals forces and UHV-bonded ones by covalent bonds. Annealing the pre-bonded hydrophilic and hydrophobic wafer pairs in argon for 2 h at different temperatures increases the initially low bonding energy. UHV-bonded wafer pairs were also annealed to compare the results. Transmission electron microscopy (TEM) investigations show nano-voids at the interface. The void density depends on the initial bonding strength. During annealing the shape, coverage and density of the voids change significantly

  12. Electron Microscopy Center (EMC)

    Data.gov (United States)

    Federal Laboratory Consortium — The Electron Microscopy Center (EMC) at Argonne National Laboratory develops and maintains unique capabilities for electron beam characterization and applies those...

  13. Coherent light microscopy

    CERN Document Server

    Ferraro, Pietro; Zalevsky, Zeev

    2011-01-01

    This book deals with the latest achievements in the field of optical coherent microscopy. While many other books exist on microscopy and imaging, this book provides a unique resource dedicated solely to this subject. Similarly, many books describe applications of holography, interferometry and speckle to metrology but do not focus on their use for microscopy. The coherent light microscopy reference provided here does not focus on the experimental mechanics of such techniques but instead is meant to provide a users manual to illustrate the strengths and capabilities of developing techniques. Th

  14. Bridging fluorescence microscopy and electron microscopy

    NARCIS (Netherlands)

    Giepmans, Ben N. G.

    Development of new fluorescent probes and fluorescence microscopes has led to new ways to study cell biology. With the emergence of specialized microscopy units at most universities and research centers, the use of these techniques is well within reach for a broad research community. A major

  15. Progress and applications of in situ transmission electron microscopy

    International Nuclear Information System (INIS)

    Wang Rongming; Liu Jialong; Song Yuanjun

    2015-01-01

    Recent progress in the application of in situ transmission electron microscopy (TEM) is briefly reviewed. It is emphasized that the development of advanced in situ TEM techniques makes it possible to investigate the evolution of materials under heat, strain, magnetic field, electric field or chemical reaction environments on the atomic scale. The mechanism of the microstructure evolution under various conditions and the relationship between the atomic structures and their properties can be obtained, which is beneficial for the design of new materials with tailored properties. The clarification of the structure-property relationship will help to develop new materials and solve related basic problems in the field of condensed matter physics. (authors)

  16. Transmission electron microscopy investigation of Bi-2223/Ag tapes

    DEFF Research Database (Denmark)

    Andersen, L.G.; Bals, S.; Tendeloo, G. Van

    2001-01-01

    during the tape processing, (3) a study of the grain boundaries on an atomic scale, including intergrowth investigations. Tapes with different process parameters have been compared with respect to the microstructure. A fully processed tape has on the average 50% thicker Bi-2223 grains than a tape after......The microstructure of (Bi,Pb)(2)Sr2Ca2CuOx (Bi-2223) tapes has been investigated by means of transmission electron microscopy (TEM) and high-resolution TEM. The emphasis has been placed on: (1) an examination of the grain morphology and size, (2) grain and colony boundary angles, which are formed...

  17. Early studies of placental ultrastructure by electron microscopy

    DEFF Research Database (Denmark)

    Carter, A M; Enders, A C

    2016-01-01

    many other scientists to Washington University in St. Louis. Work on human placental ultrastructure was initiated at Cambridge and Kyoto whilst domestic animals were initially studied by Björkman in Stockholm and electron micrographs of bat placenta were published by Wimsatt of Cornell University......BACKGROUND: Transmission electron microscopy (TEM) was first applied to study placental ultrastructure in the 1950's. We review those early studies and mention the scientists that employed or encouraged the use of TEM. FINDINGS: Among the pioneers Edward W. Dempsey was a key figure who attracted...

  18. Thin dielectric film thickness determination by advanced transmission electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Diebold, A.C.; Foran, B.; Kisielowski, C.; Muller, D.; Pennycook, S.; Principe, E.; Stemmer, S.

    2003-09-01

    High Resolution Transmission Electron Microscopy (HR-TEM) has been used as the ultimate method of thickness measurement for thin films. The appearance of phase contrast interference patterns in HR-TEM images has long been confused as the appearance of a crystal lattice by non-specialists. Relatively easy to interpret crystal lattice images are now directly observed with the introduction of annular dark field detectors for scanning TEM (STEM). With the recent development of reliable lattice image processing software that creates crystal structure images from phase contrast data, HR-TEM can also provide crystal lattice images. The resolution of both methods was steadily improved reaching now into the sub Angstrom region. Improvements in electron lens and image analysis software are increasing the spatial resolution of both methods. Optimum resolution for STEM requires that the probe beam be highly localized. In STEM, beam localization is enhanced by selection of the correct aperture. When STEM measurement is done using a highly localized probe beam, HR-TEM and STEM measurement of the thickness of silicon oxynitride films agree within experimental error. In this paper, the optimum conditions for HR-TEM and STEM measurement are discussed along with a method for repeatable film thickness determination. The impact of sample thickness is also discussed. The key result in this paper is the proposal of a reproducible method for film thickness determination.

  19. SIZE OF BOEHMITE NANOPARTICLES BY TEM IMAGES ANALYSIS

    Directory of Open Access Journals (Sweden)

    Maxime Moreaud

    2011-05-01

    Full Text Available Transition aluminas, and especially the gamma type, are largely used as catalyst supports in refining and petrochemicals. Most studies focus on properties resulting from material texture and casting (specific surface, porous volume, pore shape and diameter. However, surface properties of alumina should be considered as well, as the catalytic activity is tightly related to the structure of exposed crystalline faces. As γ alumina results from controlled thermal treatment of boehmite γ-AlOOH by a topotactic transformation, the nature of exposed crystalline planes is related to the starting material. Therefore, the synthesis of the oxihydroxide γ-AlOOH, and especially size and shape of these particles, is critical in determining the relevant surface properties. Unlike often aggregated alumina, boehmite nanoparticles can be observed by TEM. Analysis of these TEM images can be performed to estimate the size of the boehmite nanoparticles. Information about morphology of the nanoparticles is obtained by the analysis of the covariance, modeling micrographs by a dilution model.

  20. Complications of transanal endoscopic microsurgery (TEMS): a prospective audit.

    Science.gov (United States)

    Bignell, M B; Ramwell, A; Evans, J R; Dastur, N; Simson, J N L

    2010-07-01

    The aim of this study was to determine the postoperative complications of Transanal Endoscopic Microsurgery (TEMS) excision of rectal lesions. A prospective audit of 262 consecutive TEMS procedures performed by a single surgeon between 1999 and 2008. The mean age of patients was 72 years. The mean area of the lesions excised was 17.5 cm(2) with a mean diameter of 4.5 cm at a mean distance of 7.4 cm from the dentate line. There were 201 full thickness excisions, 51 partial thickness excisions and nine were mixed or unclassified. Thirty-three (13%) patients developed 41 complications. There were two (0.8%) deaths within 30 days. Pelvic sepsis occurred in seven (3%) patients and was significantly more common after excision of low lesions within 2 cm of the dentate line. Postoperative haemorrhage occurred in seven (3%) patients and was significantly less common when dissection was performed with ultrasonic dissection than with diathermy. Fourteen (5%) patients developed acute urinary retention. Four (1.5%) patients developed rectal stenosis and four (1.5%) suffered uncomplicated surgical emphysema that required no treatment. Transanal endoscopic microsurgery is a safe operation with a low mortality and morbidity. Pelvic sepsis is more common after excision of lesions within 2 cm of the dentate line. Ultrasonic dissection is associated with less postoperative haemorrhage than diathermy.

  1. TEM studies of plasma nitrided austenitic stainless steel.

    Science.gov (United States)

    Stróz, D; Psoda, M

    2010-03-01

    Cross-sectional transmission electron microscopy and X-ray phase analysis were used to study the structure of a layer formed during nitriding the AISI 316L stainless steel at temperature 440 degrees C. It was found that the applied treatment led to the formation of 6-microm-thick layer of the S-phase. There is no evidence of CrN precipitation. The X-ray diffraction experiments proved that the occurred austenite lattice expansion - due to nitrogen atoms - depended on the crystallographic direction. The cross-sectional transmission electron microscopy studies showed that the layer consisted of a single cubic phase that contained a lot of defects such as dislocations, stacking faults, slip bands and twins. The high-resolution electron microscopy observations were applied to study the defect formation due to the nitriding process. It was shown that the presence of great number of stacking faults leads to formation of nanotwins. Weak, forbidden {100} reflections were still another characteristic feature of the S-phase. These were not detected in the X-ray spectra of the phase. Basing on the high-resolution electron microscopy studies it can be suggested that the short-range ordering of the nitrogen atoms in the octahedral sites inside the f.c.c. matrix lattice takes place and gives rise to appearance of these spots. It is suggested that the cubic lattice undergoes not only expansion but also slight rombohedral distortion that explains differences in the lattice expansion for different crystallographic directions.

  2. The investigation of nanostructures of magnetic recording media by TEM

    International Nuclear Information System (INIS)

    Peng Yingguo; Ohkubo, Tadakatsu; Laughlin, David E.

    2003-01-01

    Diverse applications of transmission electron microscopy techniques used in investigating the nanostructures of magnetic recording materials are presented. Specimen preparation methods are discussed for the specific case of magnetic thin film recording media. Investigations of the crystallographic orientation, grain size and distribution, and interfacial nanostructures are presented

  3. A TEM Study on the Microstructure of Fine Flaky Graphite

    DEFF Research Database (Denmark)

    Moumeni, Elham; Tiedje, Niels Skat; Horsewell, Andy

    In this investigation the microstructure of the graphite flakes in titanium alloyed cast iron is studied using electron microscopy techniques. Based on this information, growth models for the platelets in the fine graphite flakes in cast iron are considered. Detailed crystallographic analysis...... of the defects observed such as multiple twin boundaries and possible spiral growth configurations are required...

  4. Challenges in TEM sample preparation of solvothermally grown CuInS2 films.

    Science.gov (United States)

    Frank, Anna; Changizi, Rasa; Scheu, Christina

    2018-06-01

    Transmission electron microscopy (TEM) is a widely used tool to characterize materials. The required samples need to be electron transparent which should be achieved without changing the microstructure. This work describes different TEM sample preparation techniques of nanostructured CuInS 2 thin films on fluorine-doped tin oxide substrates, synthesized solvothermally using l-cysteine as sulfur source. Focused ion beam lamellae, conventional cross section samples and scratch samples have been prepared and investigated. It was possible to prepare appropriate samples with each technique, however, each technique brings with it certain advantages and disadvantages. FIB preparation of solvothermally synthesized CuInS 2 suffers from two main drawbacks. First, the whole CuInS 2 layer displays a strongly increased Cu content caused by Cu migration and preferential removal of In. Further, electron diffraction shows the formation of an additional CuS phase after Ga + bombardment. Second, diffraction analysis is complicated by a strong contribution of crystalline Pt introduced during the FIB preparation and penetrating into the porous film surface. The conventional cross sectional CuInS 2 sample also shows a Cu signal enhancement which is caused by contribution of the brass tube material used for embedding. Additionally, Cu particles have been observed inside the CuInS 2 which have been sputtered on the film during preparation. Only the scratch samples allow an almost artefact-free and reliable elemental quantification using energy-dispersive X-ray spectroscopy. However, scratch samples suffer from the drawback that it is not possible to determine the layer thickness, which is possible for both cross sectional preparation techniques. Consequently, it is concluded that the type of sample preparation should be chosen dependent on the required information. A full characterization can only be achieved when the different techniques are combined. Copyright © 2018 Elsevier Ltd. All

  5. TEM investigation of irradiated U-7 weight percent Mo dispersion fuel

    International Nuclear Information System (INIS)

    Van den Berghe, S.

    2009-01-01

    In the FUTURE experiment, fuel plates containing U-7 weight percent Mo atomized powder were irradiated in the BR2 reactor. At a burn-up of approximately 33 percent 235 U (6.5 percent FIMA or 1.41 10 21 fissions/cm 3 meat), the fuel plates showed an important deformation and the irradiation was stopped. The plates were submitted to detailed PIE at the Laboratory for High and Medium level Activity. The results of these examinations were reported in the scientific report of last year and published in open literature. Since then, the microstructural aspects of the FUTURE fuel were studied in more detail using transmission electron microscopy (TEM), in an attempt to understand the nature of the interaction phase and the fission gas behavior in the atomized U(Mo) fuel. The FUTURE experiment is regarded as the definitive proof that the classical atomized U(Mo) dispersion fuel is not stable under irradiation, at least in the conditions required for normal operation of plate-type fuel. The main cause for the instability was identified to be the irradiation behavior of the U(Mo)-Al interaction phase which is formed between the U(Mo) particles and the pure aluminum matrix during irradiation. It is assumed to become amorphous under irradiation and as such cannot retain the fission gas in stable bubbles. As a consequence, gas filled voids are generated between the interaction layer and the matrix, resulting in fuel plate pillowing and failure. The objective of the TEM investigation was the confirmation of this assumption of the amorphisation of the interaction phase. A deeper understanding of the actual nature of this layer and the fission gas behaviour in these fuels in general can allow a more oriented search for a solution to the fuel failures

  6. Investigation of the agglomeration and amorphous transformation effects of neutron irradiation on the nanocrystalline silicon carbide (3C-SiC) using TEM and SEM methods

    Energy Technology Data Exchange (ETDEWEB)

    Huseynov, Elchin M., E-mail: elchin.h@yahoo.com [Department of Nanotechnology and Radiation Material Science, National Nuclear Research Center, Inshaatchilar pr. 4, AZ 1073 Baku (Azerbaijan); Institute of Radiation Problems of Azerbaijan National Academy of Sciences, B.Vahabzade 9, AZ 1143 Baku (Azerbaijan)

    2017-04-01

    Nanocrystalline 3C-SiC particles irradiated by neutron flux during 20 h in TRIGA Mark II light water pool type research reactor. Silicon carbide nanoparticles were analyzed by Scanning Electron Microscope (SEM) and Transmission Electron Microscopy (TEM) devices before and after neutron irradiation. The agglomeration of nanoparticles was studied comparatively before and after neutron irradiation. After neutron irradiation the amorphous layer surrounding the nanoparticles was analyzed in TEM device. Neutron irradiation defects in the 3C-SiC nanoparticles and other effects investigated by TEM device. The effect of irradiation on the crystal structure of the nanomaterial was studied by selected area electron diffraction (SAED) and electron diffraction patterns (EDP) analysis.

  7. Characterization of TEM Moiré Patterns Originating from Two Monolayer Graphenes Grown on the Front and Back Sides of a Copper Substrate by CVD Method

    Science.gov (United States)

    Yamazaki, Kenji; Maehara, Yosuke; Gohara, Kazutoshi

    2018-06-01

    The number of layers affects the electronic properties of graphene owing to its unique band structure, called the Dirac corn. Raman spectroscopy is a key diagnostic tool for identifying the number of graphene layers and for determining their physical properties. Here, we observed moiré structures in transmission electron microscopy (TEM) observations; these are signature patterns in multilayer, although Raman spectra showed the typical intensity of the 2D/G peak in the monolayer. We also performed a multi-slice TEM image simulation to compare the 3D atomic structures of the two graphene membranes with experimental TEM images. We found that the experimental moiré image was constructed with a 9-12 Å interlayer distance between graphene membranes. This structure was constructed by transferring CVD-grown graphene films that formed on both sides of the Cu substrate at once.

  8. Dynamics of electrochemical lithiation/delithiation of graphene-encapsulated silicon nanoparticles studied by in-situ TEM.

    Science.gov (United States)

    Luo, Langli; Wu, Jinsong; Luo, Jiayan; Huang, Jiaxing; Dravid, Vinayak P

    2014-01-24

    The incorporation of nanostructured carbon has been recently reported as an effective approach to improve the cycling stability when Si is used as high-capacity anodes for the next generation Li-ion battery. However, the mechanism of such notable improvement remains unclear. Herein, we report in-situ transmission electron microscopy (TEM) studies to directly observe the dynamic electrochemical lithiation/delithiation processes of crumpled graphene-encapsulated Si nanoparticles to understand their physical and chemical transformations. Unexpectedly, in the first lithiation process, crystalline Si nanoparticles undergo an isotropic to anisotropic transition, which is not observed in pure crystalline and amorphous Si nanoparticles. Such a surprising phenomenon arises from the uniformly distributed localized voltage around the Si nanoparticles due to the highly conductive graphene sheets. It is observed that the intimate contact between graphene and Si is maintained during volume expansion/contraction. Electrochemical sintering process where small Si nanoparticles react and merge together to form large agglomerates following spikes in localized electric current is another problem for batteries. In-situ TEM shows that graphene sheets help maintain the capacity even in the course of electrochemical sintering. Such in-situ TEM observations provide valuable phenomenological insights into electrochemical phenomena, which may help optimize the configuration for further improved performance.

  9. Copper implantation defects in MgO observed by positron beam analysis, RBS and X-TEM

    International Nuclear Information System (INIS)

    Huis, M.A. van; Fedorov, A.V.; Veen, A. van; Smulders, P.J.M.; Kooi, B.J.; Hosson, J.Th.M. de

    2000-01-01

    In this work, effects of copper ion implantation in MgO were studied. (1 0 0) MgO samples were implanted with 50 keV Cu ions and thermally annealed stepwise in air for 30 minutes at 550, 750, 1000, 1250 and 1350 K. After ion implantation and after each annealing step, the samples were analysed with positron beam analysis (PBA). Use was also made of Rutherford backscattering spectrometry/channeling (RBS-C) and cross-sectional transmission electron microscopy (X-TEM). The combination of these techniques enabled to monitor the depth resolved evolution of both created defects and the copper atom depth distribution. PBA results show that copper implantation at a dose of 10 15 ions cm -2 yields a single layer of vacancy type defects after annealing. However a copper implantation at a dose of 10 16 ions cm -2 clearly yields two layers of defects in the material after annealing, separated by an intermediate layer. In both layers nanocavities have been identified. RBS experimental results show that the implanted copper atoms diffuse into the bulk material during annealing. X-TEM and channeling results show that after annealing, the lattice of the copper nanoprecipitates is epitaxial to the MgO host lattice. Under some circumstances, copper precipitates and small voids can co-exist. Furthermore, X-TEM measurements show that the nanocavities have rectangular shapes

  10. TEM microstructural characterization of melt-spun aged Al-6Si-3Cu-xMg alloys

    International Nuclear Information System (INIS)

    Lopez, Ismeli Alfonso; Zepeda, Cuauhtemoc Maldonado; Gonzalez Reyes, Jose Gonzalo; Flores, Ariosto Medina; Rodriguez, Juan Serrato; Gomez, Luis Bejar

    2007-01-01

    Three Al-6Si-3Cu-xMg alloys (x = 0.59, 3.80 and 6.78 wt.%) were produced using melt-spinning. As-melt-spun ribbons were aged at 150, 180 and 210 deg. C for times between 0.05 and 100 h. Microstructural changes were examined using transmission electron microscopy (TEM) and microhardness was measured. TEM analysis of the as-melt-spun alloys revealed 5 nm nanoparticles and larger particles (50 nm) composed of Al 2 Cu (θ) for the 0.59% Mg alloy and Al 5 Cu 2 Mg 8 Si 6 (Q) for 3.80% and 6.78% Mg alloys. Silicon solid solubility was extended to 9.0 at.% and Mg in solid solution reached 6.7 at.%. After aging treatments the 6.78% Mg alloy exhibited the most significant increase in microhardness, reaching 260 kg/mm 2 . TEM analysis of aged specimens also showed θ and Q phase (5-20 nm nanoparticles and 35-40 nm particles). The combination of the volume fraction and size of the particles plays an important role in microhardness variation

  11. A TEM quantitative evaluation of strengthening in an Mg-RE alloy reinforced with SiC

    International Nuclear Information System (INIS)

    Cabibbo, Marcello; Spigarelli, Stefano

    2011-01-01

    Magnesium alloys containing rare earth elements are known to have high specific strength, good creep and corrosion resistance up to 523 K. The addition of SiC ceramic particles strengthens the metal matrix composite resulting in better wear and creep resistance while maintaining good machinability. The role of the reinforcement particles in enhancing strength can be quantitatively evaluated using transmission electron microscopy (TEM). This paper presents a quantitative evaluation of the different strengthening contributions, determined through TEM inspections, in an SiC Mg-RE composite alloy containing yttrium, neodymium, gadolinium and dysprosium. Compression tests at temperatures ranging between 290 and 573 K were carried out. The microstructure strengthening mechanism was studied for all the compression conditions. Strengthening was compared to the mechanical results and the way the different contributions were combined is also discussed and justified. - Research Highlights: → TEM yield strengthening terms evaluation on a Mg-RE SiC alloy. → The evaluation has been extended to different compression temperature conditions. → Linear and Quadratic sum has been proposed and validated. → Hall-Petch was found to be the most prominent strengthening contributions.

  12. Tourism Employment Module (TEM: Case of the Czech Republic

    Directory of Open Access Journals (Sweden)

    Zdeněk Lejsek

    2011-09-01

    Full Text Available Tourism Employment Module (TEM provides information on the significance and contribution of tourism for the national economy in terms of employment. It refers to a system of tables describing the main economic characteristics of tourism (i.e. number of jobs and people employed in tourism by industry, seasonality, working scheme,permanency of job, sex, age groups, level of education or nationality and classifying thereby tourism as one of branches in the system of national accounts. The article describes basic methodological concept and structure of this tool (and approaches to measuring employment in the tourist industry in general, exploited data sources and provides a brief information on the type and form of publishing of the results as well as the data on principalmacroeconomic indicators of tourism-related industries in the Czech Republic in 2003–2009.

  13. TEM examination of irradiated zircaloy-2 pressure tube material

    International Nuclear Information System (INIS)

    Srivastava, D.; Tewari, R.; Dey, G.K.; Sharma, B.P.; Sah, D.N.; Banerjee, Suparna; Sahoo, K.C.

    2005-09-01

    In the present work, microstructure of the zircaloy-2 pressure tube material irradiated in the Indian Pressurized Heavy Water RAPP-1. Reactor (PHWR) has been examined for the first time using transmission electron microscope (TEM). The samples were obtained from a zircaloy-2 pressure tube, which had been in operation in the high flux region of Rajasthan Atomic Power Station Unit -1, for a period for 6.77 effective full power years (EFPYs) and expected to have a cumulative radiation damage of about 3 dpa. In this study irradiated microstructure has been characterized and compared it with the microstructure of the unirradiated pressure tube samples. The effect of irradiation on the hydriding behaviour is also studied. (author)

  14. Water state and TEM analysis of Konjac irradiation copolymer

    International Nuclear Information System (INIS)

    Geng Shengrong; Xia Hezhou; Chen Xueling; Ye Lixiu; Hua Yuejin

    2012-01-01

    To study the absorption performance of Konjac-AA copolymer prepared by irradiation, the water absorbent capacity, sorbent speed and water keeping ability was determined and DSC and TEM analysis were used to explore the water content and structure characters. The results showed that on room temperature the largest water absorption speed was 16 g · g -1 · min -1 at, and the largest water absorption was 400 times at 60 min. The water absorption was affected by granularity, temperature, ion content and ion type, especially the ion type, the water keeping ability was affected by temperature and time, which was up to 35% while the fully water absorbed copolymer was kept under room temperature for 15 d. The free and bounder water content which was assimilated by the plants was 99.617%. The gel stale co polymer has a three-dimensional structure of spiral, which was constituted by spherical objects of varying sizes. (authors)

  15. A tem investigation on intermetallic particles in zircaloy-2

    International Nuclear Information System (INIS)

    Sudarminto, Harini Sosiati; Kuwano, Noriyuki; Oki, Kensuke

    1996-01-01

    Tem investigation were conducted on the heat treated zircaloy-2 having the composition of Zr containing 1.6% Sn, 0.2% Fe, 0.1% Cr and 0.05% Ni (%wt) in order tostudy the characteristics of intermetallic particles related to the microstructural basis on the corrosion effect. Forged zircaloy-2 was annealed in the β-phase at 1050 C degrees for various isothermally in the α-phase region at 650 and 750 C degrees, followed by water quenching. The size precipates, the lower became their number. By increasing the annealing temperature, the growth of precipitates formed in this zircaloy-2 were of the Zr(Cr,Fe) 2 and Zr 2 (Fe,Cr,Ni) types. These kinds of precipitates and the ratios of Fe/Cr were independent of size and shape of precipitates and annealing time and temperature. (author), 16 refs, 2 tabs, 5 figs

  16. Properties of TEM standing waves with E||B

    Science.gov (United States)

    Zaghloul, H.; Buckmaster, H. A.

    This paper summarizes the known properties of E∥B TEM standing waves and shows that for such waves (i) E and B cannot be linearly polarized, (ii) E ≠ αB where α is a constant (iii) it is impossible to find a Lorentz frame where E>B, (iv) direction of the propagation vector cannot be inferred from the fields at one point of the space, (v) their behaviour under Lorentz, parity, time-reversal and gauge transformations is proper, (vi) both Lorentz invariants E2 - B2 and E·B are nonzero, (vii) the magnetic helicity may be nonzero, (viii) the magnetic field may be force-free, and (ix) kμFμv ≠ 0. It also shows how electromagnetic waves can be classified using Lorentz invariants. Cet article résume les qualités connues des ondes stationnaires E∥B TEM et montre que pour des ondes parallèles (i) E et B ne peuvent pas être polarisées linéairement, (ii) E ≠ αB où a est une constante, (iii) il est impossible de trouver une construction de Lorentz où E>B, (iv) la direction de propagation d'un vecteur ne peut pas être déduite des opérations à un point d'intervalle, (v) leur conduite sous Lorentz, parité, temps inverse et transformations de jauge est propre, (vi) les deux invariants de Lorentz E2 - B2 et E·B sont non nulles (vii) l'hélice magnétique peut être non nulle (viii) l'opération magnétique peut être de force libre et (ix) KμFμ v ≠ 0. Ceci montre aussi comment les ondes électromagnétiques peuvent être classifiées, en employant les invariants de Lorentz.

  17. An alternative to the TEM (Transformed Eulerian Mean) equations

    Science.gov (United States)

    Gaßmann, Almut

    2013-04-01

    The TEM equations constitute a powerful means to get access to the residual circulation. However, due to their foundation on the wave perspective, they deliver only a zonally averaged picture without access to the three-dimensional structure or the local origins of the residual circulation. Therefore it is worth to investigate whether there are alternatives. The pathway followed here is to perform a transformation of the momentum and the potential temperature equation before taking the zonal mean. This is done by removing the steady state ideal wind solution vid = ?×?B-(?±P) from the equations (? - potential temperature, B - Bernoulli function, P - Ertel's potential vorticity EPV, ?± - density). The advantage of that approach is that the total EPV-flux does no longer contain an explicitly visible 'do-nothing-flux'. This flux, ?? ×?B, does only vanish when averaging on isentropic surfaces, but not on other isosurfaces. Here we find the reason why the conventional zonal mean on isentropes delivers a direct overturning cell on each hemisphere, whereas on other isosurfaces we obtain the typical three-cell structure with Headley, Ferrel, and polar cells. It will be demonstrated and made visible through idealized climate experiments with the ICON-IAP model that the zonal averages of the nonideal wind components vnid = v - vid and wnid = w - wid constitute similar direct overturning cells on non-isentropic surfaces as obtained with the TEM-generated v* and w*. It is also interesting to inspect fields of local nonideal wind components, the very origin of the residual circulation.

  18. Confocal Raman microscopy

    CERN Document Server

    Dieing, Thomas; Hollricher, Olaf

    2018-01-01

    This second edition provides a cutting-edge overview of physical, technical and scientific aspects related to the widely used analytical method of confocal Raman microscopy. The book includes expanded background information and adds insights into how confocal Raman microscopy, especially 3D Raman imaging, can be integrated with other methods to produce a variety of correlative microscopy combinations. The benefits are then demonstrated and supported by numerous examples from the fields of materials science, 2D materials, the life sciences, pharmaceutical research and development, as well as the geosciences.

  19. Comprehensive analysis of TEM methods for LiFePO4/FePO4 phase mapping: spectroscopic techniques (EFTEM, STEM-EELS) and STEM diffraction techniques (ACOM-TEM).

    Science.gov (United States)

    Mu, X; Kobler, A; Wang, D; Chakravadhanula, V S K; Schlabach, S; Szabó, D V; Norby, P; Kübel, C

    2016-11-01

    Transmission electron microscopy (TEM) has been used intensively in investigating battery materials, e.g. to obtain phase maps of partially (dis)charged (lithium) iron phosphate (LFP/FP), which is one of the most promising cathode material for next generation lithium ion (Li-ion) batteries. Due to the weak interaction between Li atoms and fast electrons, mapping of the Li distribution is not straightforward. In this work, we revisited the issue of TEM measurements of Li distribution maps for LFP/FP. Different TEM techniques, including spectroscopic techniques (energy filtered (EF)TEM in the energy range from low-loss to core-loss) and a STEM diffraction technique (automated crystal orientation mapping (ACOM)), were applied to map the lithiation of the same location in the same sample. This enabled a direct comparison of the results. The maps obtained by all methods showed excellent agreement with each other. Because of the strong difference in the imaging mechanisms, it proves the reliability of both the spectroscopic and STEM diffraction phase mapping. A comprehensive comparison of all methods is given in terms of information content, dose level, acquisition time and signal quality. The latter three are crucial for the design of in-situ experiments with beam sensitive Li-ion battery materials. Furthermore, we demonstrated the power of STEM diffraction (ACOM-STEM) providing additional crystallographic information, which can be analyzed to gain a deeper understanding of the LFP/FP interface properties such as statistical information on phase boundary orientation and misorientation between domains. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Transmission electron microscopy analysis of hydroxyapatite nanocrystals from cattle bones

    International Nuclear Information System (INIS)

    Patel, Sangeeta; Wei, Shanghai; Han, Jie; Gao, Wei

    2015-01-01

    In this present study, hydroxyapatite which was obtained from cattle bones has been heat treated at temperature 400 °C and 600 °C. The microstructure after the treatment has been studied in detail using Transmission electron microscopy (TEM) and X-ray diffraction techniques. The TEM results indicate that natural bone consists of collagen and hydroxyapatite nano-crystals which are needle shaped. The heat treatment influences the crystallinity and growth of these hydroxyapatite nano-crystals known as ‘crystal maturation’ or ‘crystal ageing’. - Highlights: • Hydroxyapatite is obtained from cattle bones. • Material has been characterised using XRD and TEM. • Crystal growth and orientation has been studied in detail.

  1. Transmission electron microscopy analysis of hydroxyapatite nanocrystals from cattle bones

    Energy Technology Data Exchange (ETDEWEB)

    Patel, Sangeeta, E-mail: spt658@aucklanduni.ac.nz [Department of Chemical and Materials Engineering, The University of Auckland, 20 Symonds Street, Auckland 1010 (New Zealand); Wei, Shanghai [Department of Chemical and Materials Engineering, The University of Auckland, 20 Symonds Street, Auckland 1010 (New Zealand); Han, Jie [Department of Civil and Environmental Engineering, University of Illinois at Urbana-Champaign, 205 North Mathews Avenue, Urbana, IL (United States); Gao, Wei [Department of Chemical and Materials Engineering, The University of Auckland, 20 Symonds Street, Auckland 1010 (New Zealand)

    2015-11-15

    In this present study, hydroxyapatite which was obtained from cattle bones has been heat treated at temperature 400 °C and 600 °C. The microstructure after the treatment has been studied in detail using Transmission electron microscopy (TEM) and X-ray diffraction techniques. The TEM results indicate that natural bone consists of collagen and hydroxyapatite nano-crystals which are needle shaped. The heat treatment influences the crystallinity and growth of these hydroxyapatite nano-crystals known as ‘crystal maturation’ or ‘crystal ageing’. - Highlights: • Hydroxyapatite is obtained from cattle bones. • Material has been characterised using XRD and TEM. • Crystal growth and orientation has been studied in detail.

  2. Practical aspects of the use of the X(2) holder for HRTEM-quality TEM sample preparation by FIB.

    Science.gov (United States)

    van Mierlo, Willem; Geiger, Dorin; Robins, Alan; Stumpf, Matthias; Ray, Mary Louise; Fischione, Paul; Kaiser, Ute

    2014-12-01

    The X(2) holder enables the effective production of thin, electron transparent samples for high-resolution transmission electron microscopy (HRTEM). Improvements to the X(2) holder for high-quality transmission electron microscopy (TEM) sample preparation are presented in this paper. We discuss the influence of backscattered electrons (BSE) from the sample holder in determining the lamella thickness in situ and demonstrate that a significant improvement in thickness determination can be achieved by comparatively simple means using the relative BSE intensity. We show (using Monte Carlo simulations) that by taking into account the finite collection angle of the electron backscatter detector, an approximately 20% underestimation of the lamella thickness in a silicon sample can be avoided. However, a correct thickness determination for light-element lamellas still remains a problem with the backscatter method; we introduce a more accurate method using the energy dispersive X-ray spectroscopy (EDX) signal for in situ thickness determination. Finally, we demonstrate how to produce a thin lamella with a nearly damage-free surface using the X(2) holder in combination with sub-kV polishing in the Fischione Instruments׳ NanoMill(®) TEM specimen preparation system. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. A detailed TEM and SEM study of Ni-base alloys oxide scales formed in primary conditions of pressurized water reactor

    International Nuclear Information System (INIS)

    Sennour, Mohamed; Marchetti, Loic; Martin, Frantz; Perrin, Stephane; Molins, Regine; Pijolat, Michele

    2010-01-01

    The oxide film formed on nickel-based alloys in pressurized water reactors (PWR) primary coolant conditions (325 o C, aqueous media) is very thin, in the range of 1-100 nm thick, depending on the surface state and on the corrosion test duration. The nature and the structure of this scale have been investigated by Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM). TEM observations revealed an oxide layer divided in two parts. The internal layer was mainly composed of a continuous spinel layer, identified as a mixed iron and nickel chromite (Ni (1-x) Fe x Cr 2 O 4 ). Moreover, nodules of Cr 2 O 3 , with a size about 5 nm, were present at the interface between this spinel and the alloy. No chromium depletion was observed in the alloy, at the alloy/oxide interface. The external layer is composed of large crystallites corresponding to a spinel structure rich in iron (Ni (1-z) Fe (2+z) O 4 ) resulting from precipitation phenomena. SEM and TEM observations showed a link between the nucleation and/or the growth of crystallites of nickel ferrite and the crystallographic orientation of the substrate. A link between the presence of surface defects and the nucleation of the crystallites was also underlined by SEM observations. Partially hydrated nickel hydroxide, was also observed by TEM in the external scale. Based on these results, some considerations about the mechanism of formation of this oxide layer are discussed.

  4. In situ TEM investigation on the precipitation behavior of μ phase in Ni-base single crystal superalloys

    International Nuclear Information System (INIS)

    Gao, Shuang; Liu, Zhi-Quan; Li, Cai-Fu; Zhou, Yizhou; Jin, Tao

    2016-01-01

    The precipitation behavior of μ phase in Ni-base single crystal superalloys was investigated by in situ transmission electron microscopy (TEM). A layer-by-layer growth process with a ledge propagation mechanism was first observed during in situ precipitation. Three types of μ phase with different morphologies were found, which grow along [001] μ with (001) μ planar defects, [-111] μ with (1–12) μ planar defects, as well as both directions with mixed planar defects. High-resolution TEM image and established atomic models reveal a basic growth mechanism of μ phase by stacking on (001) μ plane and randomly forming coherent planar defects, while the nucleation of incoherent (1–12) μ planar defects at the early stage of precipitation plays an important role in affecting the basic growth mechanism. The frequent faults during the stacking process of the sub-unit layers within μ lattice should be responsible for the defect formation. -- Graphical abstract: In situ transmission electron microscopy (TEM) investigations reveal the layer-by-layer growth mechanism of μ phase precipitated in Ni-base single crystal superalloys. Three types of μ phase with different morphologies were formed at 1050 °C, which grows along [001] μ with (001) μ planar defects, [-111] μ with (1–12) μ planar defects, as well as both directions with mixed planar defects respectively. Formation of (001) μ micro-twin and stacking fault is the essential feature for precipitated μ phase, while nucleation of incoherent (1–12) μ planar defects plays an important role in changing growth method. Display Omitted

  5. Determination of Morphological Parameters of Supported Gold Nanoparticles: Comparison of AFM Combined with Optical Spectroscopy and Theoretical Modeling versus TEM

    Directory of Open Access Journals (Sweden)

    Frank Hubenthal

    2012-07-01

    Full Text Available The morphology of small gold particles prepared by Volmer–Weber growth on sapphire substrates have been investigated by two different characterization techniques. First, by non-extensive atomic force microscopy (AFM in combination with optical spectroscopy and modeling of the optical properties using a theoretical model, recently developed in our group. Second, by extensive transmission electron microscopy (TEM. Comparing the results obtained with both techniques demonstrate that for small gold nanoparticles within the quasistatic limit, the morphological properties can be precisely determined by an appropriate theoretical modeling of the optical properties in combination with simple AFM measurements. The apparent mean axial ratio of the nanoparticles, i.e., the axial ratio that corresponds to the center frequency of the ensemble plasmon resonance, is obtained easily from the extinction spectrum. The mean size is determined by the nanoparticle number density and the amount of deposited material, measured by AFM and a quartz micro balance, respectively. To extract the most probable axial ratio of the nanoparticle ensemble, i.e., the axial ratio that corresponds to the most probable nanoparticle size in the ensemble, we apply the new theoretical model, which allows to extract the functional dependence of the nanoparticle shape on its size. The morphological parameters obtained with this procedure will be afterwards compared to extensive TEM measurements. The results obtained with both techniques yield excellent agreement. For example, the lateral dimensions of the nanoparticles after deposition of 15.2 × 1015 atoms/cm2 of gold has been compared. While a mean lateral diameter of (13 ± 2 nm has been extracted from AFM, optical spectroscopy and modeling, a value of (12 ± 2 nm is derived from TEM. The consistency of the results demonstrate the precision of our new model. Moreover, since our theoretical model allows to extract the functional

  6. 16S rRNA gene metabarcoding and TEM reveals different ecological strategies within the genus Neogloboquadrina (planktonic foraminifer.

    Directory of Open Access Journals (Sweden)

    Clare Bird

    Full Text Available Uncovering the complexities of trophic and metabolic interactions among microorganisms is essential for the understanding of marine biogeochemical cycling and modelling climate-driven ecosystem shifts. High-throughput DNA sequencing methods provide valuable tools for examining these complex interactions, although this remains challenging, as many microorganisms are difficult to isolate, identify and culture. We use two species of planktonic foraminifera from the climatically susceptible, palaeoceanographically important genus Neogloboquadrina, as ideal test microorganisms for the application of 16S rRNA gene metabarcoding. Neogloboquadrina dutertrei and Neogloboquadrina incompta were collected from the California Current and subjected to either 16S rRNA gene metabarcoding, fluorescence microscopy, or transmission electron microscopy (TEM to investigate their species-specific trophic interactions and potential symbiotic associations. 53-99% of 16S rRNA gene sequences recovered from two specimens of N. dutertrei were assigned to a single operational taxonomic unit (OTU from a chloroplast of the phylum Stramenopile. TEM observations confirmed the presence of numerous intact coccoid algae within the host cell, consistent with algal symbionts. Based on sequence data and observed ultrastructure, we taxonomically assign the putative algal symbionts to Pelagophyceae and not Chrysophyceae, as previously reported in this species. In addition, our data shows that N. dutertrei feeds on protists within particulate organic matter (POM, but not on bacteria as a major food source. In total contrast, of OTUs recovered from three N. incompta specimens, 83-95% were assigned to bacterial classes Alteromonadales and Vibrionales of the order Gammaproteobacteria. TEM demonstrates that these bacteria are a food source, not putative symbionts. Contrary to the current view that non-spinose foraminifera are predominantly herbivorous, neither N. dutertrei nor N. incompta

  7. Molecular identification of TEM-116 beta-lactamase gene in isolates ...

    African Journals Online (AJOL)

    Keywords: P. aeruginosa, Clinical isolates, Sequencing, TEM-116, Antibiotic susceptibility. Tropical Journal of ... organisms produce a wide range of beta ... TEM-1 is the most commonly encountered beta-lactamase in Gram-negative bacteria.

  8. International Multidisciplinary Microscopy Congress

    CERN Document Server

    Oral, Ahmet; Ozer, Mehmet; InterM; INTERM2013

    2014-01-01

    The International Multidisciplinary Microscopy Congress (INTERM2013) was organized on October 10-13, 2013. The aim of the congress was to bring together scientists from various branches to discuss the latest advances in the field of microscopy. The contents of the congress have been broadened to a more "interdisciplinary" scope, so as to allow all scientists working on related subjects to participate and present their work. These proceedings include 39 peer-reviewed technical papers, submitted by leading academic and research institutions from over 12 countries and representing some of the most cutting-edge research available. The 39 papers are grouped into the following sections: - Applications of Microscopy in the Physical Sciences - Applications of Microscopy in the Biological Sciences

  9. Imaging and Quantification of Extracellular Vesicles by Transmission Electron Microscopy.

    Science.gov (United States)

    Linares, Romain; Tan, Sisareuth; Gounou, Céline; Brisson, Alain R

    2017-01-01

    Extracellular vesicles (EVs) are cell-derived vesicles that are present in blood and other body fluids. EVs raise major interest for their diverse physiopathological roles and their potential biomedical applications. However, the characterization and quantification of EVs constitute major challenges, mainly due to their small size and the lack of methods adapted for their study. Electron microscopy has made significant contributions to the EV field since their initial discovery. Here, we describe the use of two transmission electron microscopy (TEM) techniques for imaging and quantifying EVs. Cryo-TEM combined with receptor-specific gold labeling is applied to reveal the morphology, size, and phenotype of EVs, while their enumeration is achieved after high-speed sedimentation on EM grids.

  10. In situ Transmission Electron Microscopy of catalyst sintering

    DEFF Research Database (Denmark)

    DeLaRiva, Andrew T.; Hansen, Thomas Willum; Challa, Sivakumar R.

    2013-01-01

    Recent advancements in the field of electron microscopy, such as aberration correctors, have now been integrated into Environmental Transmission Electron Microscopes (TEMs), making it possible to study the behavior of supported metal catalysts under operating conditions at atomic resolution. Here......, we focus on in situ electron microscopy studies of catalysts that shed light on the mechanistic aspects of catalyst sintering. Catalyst sintering is an important mechanism for activity loss, especially for catalysts that operate at elevated temperatures. Literature from the past decade is reviewed...... along with our recent in situ TEM studies on the sintering of Ni/MgAl2O4 catalysts. These results suggest that the rapid loss of catalyst activity in the earliest stages of catalyst sintering could result from Ostwald ripening rather than through particle migration and coalescence. The smallest...

  11. Structural characterizaiton and gas reactions of small metal particles by high-resolution, in-situ TEM and TED

    Science.gov (United States)

    1984-01-01

    The existing in-situ transmission electron microscopy (TEM) facility was improved by adding a separately pumped mini-specimen chamber. The chamber contains wire-evaporation sources for three metals and a specimen heater for moderate substrate temperatures. A sample introduction device was constructed, installed, and tested, facilitating rapid introduction of a specimen into the mini-chamber while maintaining the background pressure in that chamber in the 10(-9) millibar range. Small particles and clusters of Pd, grown by deposition from the vapor phase in an in-situ TEM facility on amorphous and crystalline support films of alumina and on ultra-thin carbon films, were analyzed by conventional high-resolution TEM and image analysis in terms of detectability, number density, and size distribution. The smallest particles that could be detected and counted contained no more than 6 atoms; size determinations could be made for particles 1 nm in diameter. The influence of various oxygen plasma treatments, annealing treatments, and of increasing the substrate temperature during deposition was investigated. The TEM technique was employed to demonstrate that under otherwise identica l conditions the lattice parameter of Pd particles in the 1 to 2 nm size range and supported in random orientation on ex-situ prepared mica films is expanded by some 3% when compared to 5 nm size particles. It is believed that this expansion is neither a small-particle diffraction effect nor due to pseudomorphism, but that it is due to a annealing-induced transformation of the small as-deposited particles with predominantly composite crystal structures into larger particles with true f.c.c. structure and thus inherently smaller lattice parameter.

  12. Cross-sectional transmission electron microscopy of semiconductors

    International Nuclear Information System (INIS)

    Sadana, D.K.

    1982-10-01

    A method to prepare cross-sectional (X) semiconductor specimens for transmission electron microscopy (TEM) has been described. The power and utility of XTEM has been demonstrated. It has been shown that accuracy and interpretation of indirect structural-defects profiling techniques, namely, MeV He + channeling and secondary ion mass spectrometry (SIMS) can be greatly enhanced by comparing their results with those obtained by XTEM from the same set of samples

  13. In-situ Isotopic Analysis at Nanoscale using Parallel Ion Electron Spectrometry: A Powerful New Paradigm for Correlative Microscopy

    Science.gov (United States)

    Yedra, Lluís; Eswara, Santhana; Dowsett, David; Wirtz, Tom

    2016-01-01

    Isotopic analysis is of paramount importance across the entire gamut of scientific research. To advance the frontiers of knowledge, a technique for nanoscale isotopic analysis is indispensable. Secondary Ion Mass Spectrometry (SIMS) is a well-established technique for analyzing isotopes, but its spatial-resolution is fundamentally limited. Transmission Electron Microscopy (TEM) is a well-known method for high-resolution imaging down to the atomic scale. However, isotopic analysis in TEM is not possible. Here, we introduce a powerful new paradigm for in-situ correlative microscopy called the Parallel Ion Electron Spectrometry by synergizing SIMS with TEM. We demonstrate this technique by distinguishing lithium carbonate nanoparticles according to the isotopic label of lithium, viz. 6Li and 7Li and imaging them at high-resolution by TEM, adding a new dimension to correlative microscopy. PMID:27350565

  14. An electron microscopy appraisal of tensile fracture in metallic glasses

    International Nuclear Information System (INIS)

    Matthews, D.T.A.; Ocelik, V.; Bronsveld, P.M.; De Hosson, J.Th.M.

    2008-01-01

    Three glass-forming alloy compositions were chosen for ribbon production and subsequent electron microscopy studies. In situ tensile testing with transmission electron microscopy (TEM), followed by ex situ TEM and ex situ scanning electron microscopy (SEM), allowed the deformation processes in tensile fracture of metallic glasses to be analysed. In situ shear band propagation was found to be jump-like, with the jump sites correlating with the formation of secondary shear bands. The effect of structural relaxation by in situ heating is also discussed. Nanocrystallization near the fracture surface was observed; however, no crystallization was also reported in the same sample and the reasons for this are discussed. Both the TEM and the SEM observations confirmed the presence of a liquid-like layer on or near the fracture surface of the ribbons. The formation of a liquid-like layer was characterized by the vein geometries and vein densities on the fracture surfaces and its dependence on shear displacement, δ, is discussed. A simple model is adapted to relate the temperature rise during shear banding to the glass transition and melting temperatures and this is used to explain the variety of fracture surfaces which are developed for macroscopically identical tensile testing of metallic glasses together with features which exhibit local melting

  15. TEM study of impurity segregations in beryllium pebbles

    Energy Technology Data Exchange (ETDEWEB)

    Klimenkov, M., E-mail: michael.klimenkov@kit.edu [Institute for Applied Materials – Applied Materials Physics, Karlsruhe Institute of Technology, Hermann-von-Helmholz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Chakin, V.; Moeslang, A. [Institute for Applied Materials – Applied Materials Physics, Karlsruhe Institute of Technology, Hermann-von-Helmholz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Rolli, R. [Institute for Applied Materials – Materials and Biomechanics, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

    2014-12-15

    Beryllium is planned to be used as a neutron multiplier in the Helium-cooled Pebble Bed European concept of a breeding blanket of demonstration power reactor DEMO. In order to evaluate the irradiation performance, individual pebbles and constrained pebble beds were neutron-irradiated at temperatures typical of fusion blankets. Beryllium pebbles 1 mm in diameter produced by the rotating electrode method were subjected to a TEM study before and after irradiation at High Flux Reactor, Petten, Netherlands at 861 K. The grain size varied in a wide range from sub-micron size up to several tens of micrometers, which indicated formation bimodal grain size distribution. Based on the application of combined electron energy loss spectroscopy and energy dispersive X-ray spectroscopy methods, we suggest that impurity precipitates play an important role in controlling the mechanical properties of beryllium. The impurity elements were present in beryllium at a sub-percent concentration form beryllide particles of a complex (Fe/Al/Mn/Cr)B composition. These particles are often ordered along dislocations lines, forming several micron-long chains. It can be suggested that fracture surfaces often extended along these chains in irradiated material.

  16. Reference nano-dimensional metrology by scanning transmission electron microscopy

    International Nuclear Information System (INIS)

    Dai, Gaoliang; Fluegge, Jens; Bosse, Harald; Heidelmann, Markus; Kübel, Christian; Prang, Robby

    2013-01-01

    Traceable and accurate reference dimensional metrology of nano-structures by scanning transmission electron microscopy (STEM) is introduced in the paper. Two methods, one based on the crystal lattice constant and the other based on the pitch of a feature pair, were applied to calibrate the TEM magnification. The threshold value, which was defined as the half-intensity of boundary materials, is suggested to extract the boundary position of features from the TEM image. Experimental investigations have demonstrated the high potential of the proposed methods. For instance, the standard deviation from ten repeated measurements of a line structure with a nominal 100 nm critical dimension (CD) reaches 1σ = 0.023 nm, about 0.02%. By intentionally introduced defocus and larger sample alignment errors, the investigation shows that these influences may reach 0.20 and 1.3 nm, respectively, indicating the importance of high-quality TEM measurements. Finally, a strategy for disseminating the destructive TEM results is introduced. Using this strategy, the CD of a reference material has been accurately determined. Its agreement over five independent TEM measurements is below 1.2 nm. (paper)

  17. U-Zr alloy: XPS and TEM study of surface passivation

    Science.gov (United States)

    Paukov, M.; Tkach, I.; Huber, F.; Gouder, T.; Cieslar, M.; Drozdenko, D.; Minarik, P.; Havela, L.

    2018-05-01

    Surface reactivity of Uranium metal is an important factor limiting its practical applications. Bcc alloys of U with various transition metals are much less reactive than pure Uranium. So as to specify the mechanism of surface protection, we have been studying the U-20 at.% Zr alloy by photoelectron spectroscopy and transmission electron microscopy. The surface was studied in as-obtained state, in various stages of surface cleaning, and during an isochronal annealing cycle. The analysis based on U-4f, Zr-3p, and O-1 s spectra shows that a Zr-rich phase segregates at the surface at temperatures exceeding 550 K, which provides a self-assembled coating. The comparison of oxygen exposure of the stoichiometric and coated surfaces shows that the coating is efficiently preventing the oxidation of uranium even at elevated temperatures. The coating can be associated with the UZr2+x phase. TEM study indicated that the coating is about 20 nm thick. For the clean state, the U-4f core-level lines of the bcc alloy are practically identical to those of α-U, revealing similar delocalization of the 5f electronic states.

  18. TEM examination of microstructural evolution during processing of 14CrYWTi nanostructured ferritic alloys

    International Nuclear Information System (INIS)

    Kishimoto, H.; Alinger, M.J.; Odette, G.R.; Yamamoto, T.

    2004-01-01

    A transmission electron microscopy (TEM) study was carried out on the co-evolution of the coarser-scale microstructural features in mechanically alloyed (MA) powders and hot isostatic press (HIP) consolidated Fe-14Cr-3W-0 and 0.4Ti-0.25Y 2 O 3 nanostructured ferritic alloys (NFAs). The pancake shaped nanoscale grains in the as-MA powders are textured and elongated parallel to the particle surface. Powder annealing results in re-crystallization at 850 deg. C and grain growth at 1150 deg. C. The grains also recrystallize and may grow in the alloys HIPed at 850 deg. C, but appear to retain a polygonized sub-grain structure. The grains are larger and more distinct in the alloys HIPed at 1000 and 1150 deg. C. However, annealing resulted in bi-modal grain size distribution. Finer grains retained a significant dislocation density and populations of small precipitates with crystal structures distinct form the matrix. The grains and precipitates were much larger in alloys without Ti

  19. In situ TEM Raman spectroscopy and laser-based materials modification

    Energy Technology Data Exchange (ETDEWEB)

    Allen, F.I., E-mail: fiallen@lbl.gov [Department of Materials Science and Engineering, University of California, Berkeley, CA 94720 (United States); National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Kim, E. [Department of Mechanical Engineering, University of California, Berkeley, CA 94720 (United States); Andresen, N.C. [Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Grigoropoulos, C.P. [Department of Mechanical Engineering, University of California, Berkeley, CA 94720 (United States); Minor, A.M., E-mail: aminor@lbl.gov [Department of Materials Science and Engineering, University of California, Berkeley, CA 94720 (United States); National Center for Electron Microscopy, Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

    2017-07-15

    We present a modular assembly that enables both in situ Raman spectroscopy and laser-based materials processing to be performed in a transmission electron microscope. The system comprises a lensed Raman probe mounted inside the microscope column in the specimen plane and a custom specimen holder with a vacuum feedthrough for a tapered optical fiber. The Raman probe incorporates both excitation and collection optics, and localized laser processing is performed using pulsed laser light delivered to the specimen via the tapered optical fiber. Precise positioning of the fiber is achieved using a nanomanipulation stage in combination with simultaneous electron-beam imaging of the tip-to-sample distance. Materials modification is monitored in real time by transmission electron microscopy. First results obtained using the assembly are presented for in situ pulsed laser ablation of MoS{sub 2} combined with Raman spectroscopy, complimented by electron-beam diffraction and electron energy-loss spectroscopy. - Highlights: • Raman spectroscopy and laser-based materials processing in a TEM are demonstrated. • A lensed Raman probe is mounted in the sample chamber for close approach. • Localized laser processing is achieved using a tapered optical fiber. • Raman spectroscopy and pulsed laser ablation of MoS{sub 2} are performed in situ.

  20. TEM Nanostructural Study of Al-6Si-3Cu-Mg Melt-Spun Ribbons

    Directory of Open Access Journals (Sweden)

    Ismeli Alfonso López

    2008-01-01

    Full Text Available Three quaternary Al-6Si-3Cu-xMg (x = 0.59, 3.80, and 6.78 wt.% alloys were produced by melt-spun and characterized using X-ray diffractometry (XRD, transmission electron microscopy (TEM, and microhardness techniques. Obtained second phases were Al2Cu( for the alloy with 0.59% Mg and Al5Cu2Mg8Si6 (Q for the alloys with 3.80 and 6.78% Mg. These phases are present as 30–50 nm or as 5–10 nm nanoparticles. Alloying elements content in solid solution increased, mainly for Si and Mg. The high alloying elements content in solid solution and the small -Al cell size for melt-spun alloys leads to microhardness values about 2 times higher than those of ingot counterparts. The microhardness increase for melt-spun alloys with 3.80 and 6.78% Mg depends on Mg content in solid solution.

  1. In situ TEM Raman spectroscopy and laser-based materials modification

    International Nuclear Information System (INIS)

    Allen, F.I.; Kim, E.; Andresen, N.C.; Grigoropoulos, C.P.; Minor, A.M.

    2017-01-01

    We present a modular assembly that enables both in situ Raman spectroscopy and laser-based materials processing to be performed in a transmission electron microscope. The system comprises a lensed Raman probe mounted inside the microscope column in the specimen plane and a custom specimen holder with a vacuum feedthrough for a tapered optical fiber. The Raman probe incorporates both excitation and collection optics, and localized laser processing is performed using pulsed laser light delivered to the specimen via the tapered optical fiber. Precise positioning of the fiber is achieved using a nanomanipulation stage in combination with simultaneous electron-beam imaging of the tip-to-sample distance. Materials modification is monitored in real time by transmission electron microscopy. First results obtained using the assembly are presented for in situ pulsed laser ablation of MoS_2 combined with Raman spectroscopy, complimented by electron-beam diffraction and electron energy-loss spectroscopy. - Highlights: • Raman spectroscopy and laser-based materials processing in a TEM are demonstrated. • A lensed Raman probe is mounted in the sample chamber for close approach. • Localized laser processing is achieved using a tapered optical fiber. • Raman spectroscopy and pulsed laser ablation of MoS_2 are performed in situ.

  2. TEM studies of domain formation mechanisms in MnV{sub 2}O{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, Y., E-mail: murakami@tagen.tohoku.ac.jp [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan); Advanced Science Institute, RIKEN, Wako 351-0198 (Japan); Nii, Y.; Arima, T. [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan); Shindo, D. [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan); Advanced Science Institute, RIKEN, Wako 351-0198 (Japan); Yanagisawa, K. [Advanced Science Institute, RIKEN, Wako 351-0198 (Japan); Okinawa Institute of Science and Technology, Onna-son, Okinawa 904-0412 (Japan); Tonomura, A. [Advanced Science Institute, RIKEN, Wako 351-0198 (Japan); Central Research Laboratory, Hitachi Ltd., Hatoyama 350-0395 (Japan); Okinawa Institute of Science and Technology, Onna-son, Okinawa 904-0412 (Japan)

    2013-11-15

    Highlights: ► Irregular shape of the phase boundary, due to the small transformation strain. ► TEM studies demonstrate the essential reduction of net magnetization by cooling. ► Twining morphology provides a key to understating of the anomalous magnetic domains. -- Abstract: Crystallographic and magnetic domains produced in a spinel-type compound MnV{sub 2}O{sub 4}, which exhibits a type of giant magnetostriction attributed to twin boundary motion, have been studied using transmission electron microscopy techniques. Although MnV{sub 2}O{sub 4} undergoes a displacive cubic-to-tetragonal transformation upon cooling, it does not show a well-defined habit plane (i.e. the plane with a specific index that is favored for minimizing the transformation) due to the small elongation/contraction in the lattice. Electron holography demonstrates a considerable reduction in the magnetic signal by cooling the tetragonal phase to 40 K. Despite the elimination of micrometer-scale ferrimagnetic domains, weak magnetic contrast still remained, indicating small residual magnetic domains in particular portions, such as in the crosshatch of twinning pairs.

  3. Microstructural characterization of XLPE electrical insulation in power cables: determination of void size distributions using TEM

    International Nuclear Information System (INIS)

    Markey, L; Stevens, G C

    2003-01-01

    In an effort to progress in our understanding of the ageing mechanisms of high voltage cables submitted to electrical and thermal stresses, we present a quantitative study of voids, the defects which are considered to be partly responsible for cable failure. We propose a method based on large data sets of transmission electron microscopy (TEM) observations of replicated samples allowing for the determination of void concentration distribution as a function of void size in the mesoscopic to microscopic range at any point in the cable insulation. A theory is also developed to calculate the effect of etching on the apparent size of the voids observed. We present the first results of this sort ever obtained on two industrial cables, one of which was aged in an AC field. Results clearly indicate that a much larger concentration of voids occur near the inner semiconductor compared to the bulk of the insulation, independently of ageing. An effect of ageing can also be seen near the inner semiconductor, resulting in an increase in the total void internal surface area and a slight shift of the concentration curve towards larger voids, with the peak moving from about 40 nm to about 50 nm

  4. TEM characterization of irradiated microstructure of Fe-9%Cr ODS and ferritic-martensitic alloys

    Science.gov (United States)

    Swenson, M. J.; Wharry, J. P.

    2018-04-01

    The objective of this study is to evaluate the effects of irradiation dose and dose rate on defect cluster (i.e. dislocation loops and voids) evolution in a model Fe-9%Cr oxide dispersion strengthened steel and commercial ferritic-martensitic steels HCM12A and HT9. Complimentary irradiations using Fe2+ ions, protons, or neutrons to doses ranging from 1 to 100 displacements per atom (dpa) at 500 °C are conducted on each alloy. The irradiated microstructures are characterized using transmission electron microscopy (TEM). Dislocation loops exhibit limited growth after 1 dpa upon Fe2+ and proton irradiation, while any voids observed are small and sparse. The average size and number density of loops are statistically invariant between Fe2+, proton, and neutron irradiated specimens at otherwise fixed irradiation conditions of ∼3 dpa, 500 °C. Therefore, we conclude that higher dose rate charged particle irradiations can reproduce the neutron irradiated loop microstructure with temperature shift governed by the invariance theory; this temperature shift is ∼0 °C for the high sink strength alloys studied herein.

  5. In situ TEM visualization of superior nanomechanical flexibility of shear-exfoliated phosphorene.

    Science.gov (United States)

    Xu, Feng; Ma, Hongyu; Lei, Shuangying; Sun, Jun; Chen, Jing; Ge, Binghui; Zhu, Yimei; Sun, Litao

    2016-07-14

    Recently discovered atomically thin black phosphorus (called phosphorene) holds great promise for applications in flexible nanoelectronic devices. Experimentally identifying and characterizing nanomechanical properties of phosphorene are challenging, but also potentially rewarding. This work combines for the first time in situ transmission electron microscopy (TEM) imaging and an in situ micro-manipulation system to directly visualize the nanomechanical behaviour of individual phosphorene nanoflakes. We demonstrate that the phosphorene nanoflakes can be easily bent, scrolled, and stretched, showing remarkable mechanical flexibility rather than fracturing. An out-of-plane plate-like bending mechanism and in-plane tensile strain of up to 34% were observed. Moreover, a facile liquid-phase shear exfoliation route has been developed to produce such mono-layer and few-layer phosphorene nanoflakes in organic solvents using only a household kitchen blender. The effects of surface tensions of the applied solvents on the ratio of average length and thickness (L/T) of the nanoflakes were studied systematically. The results reported here will pave the way for potential industrial-scale applications of flexible phosphorene nanoelectronic devices.

  6. Integrated Transmission Electron and Single‐Molecule Fluorescence Microscopy Correlates Reactivity with Ultrastructure in a Single Catalyst Particle

    OpenAIRE

    Hendriks, Frank C.; Mohammadian, Sajjad; Ristanović, Zoran; Kalirai, Sam; Meirer, Florian; Vogt, Eelco T. C.; Bruijnincx, Pieter C. A.; Gerritsen, Hans C.; Weckhuysen, Bert M.

    2017-01-01

    Abstract Establishing structure–activity relationships in complex, hierarchically structured nanomaterials, such as fluid catalytic cracking (FCC) catalysts, requires characterization with complementary, correlated analysis techniques. An integrated setup has been developed to perform transmission electron microscopy (TEM) and single‐molecule fluorescence (SMF) microscopy on such nanostructured samples. Correlated structure–reactivity information was obtained for 100 nm thin, microtomed secti...

  7. Integrated Transmission Electron and Single-Molecule Fluorescence Microscopy Correlates Reactivity with Ultrastructure in a Single Catalyst Particle

    OpenAIRE

    Hendriks, Frank C.; Mohammadian, Sajjad; Ristanovic, Zoran; Kalirai, Samanbir; Meirer, Florian; Vogt, Eelco T. C.; Bruijnincx, Pieter C. A.; Gerritsen, Hans; Weckhuysen, Bert M.

    2018-01-01

    Establishing structure–activity relationships in complex, hierarchically structured nanomaterials, such as fluid catalytic cracking (FCC) catalysts, requires characterization with complementary, correlated analysis techniques. An integrated setup has been developed to perform transmission electron microscopy (TEM) and single-molecule fluorescence (SMF) microscopy on such nanostructured samples. Correlated structure–reactivity information was obtained for 100 nm thin, microtomed sections of a ...

  8. Confocal Raman Microscopy

    CERN Document Server

    Dieing, Thomas; Toporski, Jan

    2011-01-01

    Confocal Raman Microscopy is a relatively new technique that allows chemical imaging without specific sample preparation. By integrating a sensitive Raman spectrometer within a state-of-the-art microscope, Raman microscopy with a spatial resolution down to 200nm laterally and 500nm vertically can be achieved using visible light excitation. Recent developments in detector and computer technology as well as optimized instrument design have reduced integration times of Raman spectra by orders of magnitude, so that complete images consisting of tens of thousands of Raman spectra can be acquired in seconds or minutes rather than hours, which used to be standard just one decade ago. The purpose of this book is to provide the reader a comprehensive overview of the rapidly developing field of Confocal Raman Microscopy and its applications.

  9. Characterisation of archaeological glass mosaics by electron microscopy and X-ray microanalysis

    International Nuclear Information System (INIS)

    Roe, M; Plant, S; Henderson, J; Andreescu-Treadgold, I; Brown, P D

    2006-01-01

    The combined techniques of scanning electron microscopy, energy dispersive X-ray analysis, transmission electron microscopy (TEM) and selected area electron diffraction are used to characterise the microstructures of opaque coloured glass mosaics from a mediaeval church in Torcello, Italy. Comparison of MgO/K 2 O ratios allows distinction between mediaeval and modern glass artefacts to be made. TEM investigation of inclusions indicates that relict silica is responsible for the speckled appearance of an impure mediaeval glass artefact, whilst a fine scale dispersion of elemental Cu nanoparticles is considered responsible for the orange-red colouration of a modern glass artefact

  10. Confocal scanning microscopy

    DEFF Research Database (Denmark)

    Bariani, Paolo

    This report is based on a metrological investigation on confocal microscopy technique carried out by Uffe Rolf Arlø Theilade and Paolo Bariani. The purpose of the experimental activity was twofold a metrological instrument characterization and application to assessment of rough PP injection moulded...... replicated topography. Confocal microscopy is seen to be a promising technique in metrology of microstructures. Some limitations with respect to surface metrology were found during the experiments. The experiments were carried out using a Zeiss LSM 5 Pascal microscope owned by the Danish Polymer Centre...

  11. Leakage radiation interference microscopy.

    Science.gov (United States)

    Descrovi, Emiliano; Barakat, Elsie; Angelini, Angelo; Munzert, Peter; De Leo, Natascia; Boarino, Luca; Giorgis, Fabrizio; Herzig, Hans Peter

    2013-09-01

    We present a proof of principle for a new imaging technique combining leakage radiation microscopy with high-resolution interference microscopy. By using oil immersion optics it is demonstrated that amplitude and phase can be retrieved from optical fields, which are evanescent in air. This technique is illustratively applied for mapping a surface mode propagating onto a planar dielectric multilayer on a thin glass substrate. The surface mode propagation constant estimated after Fourier transformation of the measured complex field is well matched with an independent measurement based on back focal plane imaging.

  12. Heliborne time-domain electromagnetic (TEM) surveys for uranium exploration

    International Nuclear Information System (INIS)

    Chaturvedi, A.K.

    2015-01-01

    Airborne geophysical surveys have been used extensively in petroleum, mineral exploration, and environmental mapping. Of all the geophysical methods, Electromagnetic (EM) methods, both ground and airborne are used to map the conductive ore bodies buried in the resistive bed rock. Mapping resistivity variations can help unravel complex geological problems and identify areas of hidden potential. Besides the traditional applications to ground water investigations and other natural resource exploration and geological mapping, a number of new applications have been reported. These include hazardous-waste characterization studies, precision agriculture applications, archaeological surveys etc. Airborne Electromagnetic (AEM) methods have undergone rapid improvements over the past few decades. Several new airborne Time Do-main EM (TDEM) systems appeared; existing systems were updated and/or enhanced. The use of natural field (passive) EM surveys continued to increase, with new or improved systems becoming available for both airborne and ground surveys. The number of large airborne survey systems with combined EM, magnetic, gravimetric and gamma-ray spectrometric capabilities also increased. Exploration of a mineral deposit is a multi-stage and multi-disciplinary approach that commences from regional investigations and concludes with establishing of a deposit. As economics play a major role in exploration, a proper integrated study is always beneficial in narrowing down the potential mineral target zones. Heliborne geophysical surveys are being conducted world-wide for exploration of base metals, gold, phosphorite, oil, uranium etc. that are very effective tool in identifying zones of interest accurately, economically and with less span of time. These surveys give a very good insight of surface and sub-surface geophysical signatures that can be attributed to geology with proper modeling. Heliborne Time - domain Electromagnetic (TEM) methods are well known for search of

  13. TEM assessment of defects in (CdHg)Te heterostructures

    International Nuclear Information System (INIS)

    Lawson-Jack, S.G.; Jones, I.P.; Williams, D.J.; Astles, M.G.

    1991-01-01

    This paper reports on transmission electron microscopy used to assess the defect contents of the various layers and interfaces in (CdHg)Te heterostructures. Examination of cross sectional specimens of these materials suggests that the density of misfit dislocations at the interfaces is related to the layer thicknesses, and that the high density of dislocations which are generated at the GaAs/CdTe interface are effectively prevented from penetrating into the CdHgTe epilayer by a 3 μm thick buffer layer. The majority of the dislocations in the layers were found to have a Burgers vector b = a/2 left-angle 110 right-angle and either lie approximately parallel or inclined at an angle of ∼ 60 degrees to the interfactial plane

  14. Relativistic effects in elastic scattering of electrons in TEM

    International Nuclear Information System (INIS)

    Rother, Axel; Scheerschmidt, Kurt

    2009-01-01

    Transmission electron microscopy typically works with highly accelerated thus relativistic electrons. Consequently the scattering process is described within a relativistic formalism. In the following, we will examine three different relativistic formalisms for elastic electron scattering: Dirac, Klein-Gordon and approximated Klein-Gordon, the standard approach. This corresponds to a different consideration of spin effects and a different coupling to electromagnetic potentials. A detailed comparison is conducted by means of explicit numerical calculations. For this purpose two different formalisms have been applied to the approaches above: a numerical integration with predefined boundary conditions and the multislice algorithm, a standard procedure for such simulations. The results show a negligibly small difference between the different relativistic equations in the vicinity of electromagnetic potentials, prevailing in the electron microscope. The differences between the two numeric approaches are found to be small for small-angle scattering but eventually grow large for large-angle scattering, recorded for instance in high-angle annular dark field.

  15. TEM investigation of ductile iron alloyed with vanadium.

    Science.gov (United States)

    Dymek, S; Blicharski, M; Morgiel, J; Fraś, E

    2010-03-01

    This article presents results of the processing and microstructure evolution of ductile cast iron, modified by an addition of vanadium. The ductile iron was austenitized closed to the solidus (1095 degrees C) for 100 h, cooled down to 640 degrees C and held on at this temperature for 16 h. The heat treatment led to the dissolution of primary vanadium-rich carbides and their subsequent re-precipitation in a more dispersed form. The result of mechanical tests indicated that addition of vanadium and an appropriate heat treatment makes age hardening of ductile iron feasible. The precipitation processes as well as the effect of Si content on the alloy microstructure were examined by scanning and transmission electron microscopy. It was shown that adjacent to uniformly spread out vanadium-rich carbides with an average size of 50 nm, a dispersoid composed of extremely small approximately 1 nm precipitates was also revealed.

  16. Fluorescence confocal polarizing microscopy

    Indian Academy of Sciences (India)

    Much of the modern understanding of orientational order in liquid crystals (LCs) is based on polarizing microscopy (PM). A PM image bears only two-dimensional (2D) information, integrating the 3D pattern of optical birefringence over the path of light. Recently, we proposed a technique to image 3D director patterns by ...

  17. Ballistic hole magnetic microscopy

    NARCIS (Netherlands)

    Haq, E.; Banerjee, T.; Siekman, M.H.; Lodder, J.C.; Jansen, R.

    2005-01-01

    A technique to study nanoscale spin transport of holes is presented: ballistic hole magnetic microscopy. The tip of a scanning tunneling microscope is used to inject hot electrons into a ferromagnetic heterostructure, where inelastic decay creates a distribution of electron-hole pairs.

  18. Graphene oxide and reduced graphene oxide studied by the XRD, TEM and electron spectroscopy methods

    International Nuclear Information System (INIS)

    Stobinski, L.; Lesiak, B.; Malolepszy, A.; Mazurkiewicz, M.; Mierzwa, B.; Zemek, J.; Jiricek, P.; Bieloshapka, I.

    2014-01-01

    Highlights: • Graphene oxide (FL-GOc) and reduced graphene oxide (FL-RGOc): XRD, TEM, XPS, REELS. • FL-GOc: stacking nanostructure—22 × 6 nm (DxH), 0.9 nm layers separation (XRD). • FL-RGOc: stacking nanostructure—8 × 1 nm (DxH), 0.4 nm layers separation (XRD). • Reduction: oxygen group degradation, decreasing distance between graphene layers. • Number of graphene layers in stacking nanostructure: 6–7 (FL-GOc), 2–3 (FL-RGOc). - Abstract: The commercial and synthesised few-layer graphene oxide, prepared using oxidation reactions, and few-layer reduced graphene oxide samples were structurally and chemically investigated by the X-ray diffraction (XRD), transmission electron microscopy (TEM) and electron spectroscopy methods, i.e. X-ray photoelectron spectroscopy (XPS) and reflection electron energy loss spectroscopy (REELS). The commercial graphene oxide (FL-GOc) shows a stacking nanostructure of about 22 × 6 nm average diameter by height with the distance of 0.9 nm between 6-7 graphene layers, whereas the respective reduced graphene oxide (FL-RGOc)—about 8 × 1 nm average diameter by height stacking nanostructure with the distance of 0.4 nm between 2-3 graphene layers (XRD). The REELS results are consistent with those by the XRD indicating 8 (FL-GOc) and 4 layers (FL-RGOc). In graphene oxide and reduced graphene oxide prepared from the graphite the REELS indicates 8–11 and 7–10 layers. All graphene oxide samples show the C/O ratio of 2.1–2.3, 26.5–32.1 at% of C sp 3 bonds and high content of functional oxygen groups (hydroxyl—C-OH, epoxy—C-O-C, carbonyl—C=O, carboxyl—C-OOH, water) (XPS). Reduction increases the C/O ratio to 2.8–10.3, decreases C sp 3 content to 11.4–20.3 at% and also the content of C-O-C and C=O groups, accompanied by increasing content of C-OH and C-OOH groups. Formation of additional amount of water due to functional oxygen group reduction leads to layer delamination. Removing of functional oxygen groups

  19. Shell structure of natural rubber particles: evidence of chemical stratification by electrokinetics and cryo-TEM.

    Science.gov (United States)

    Rochette, Christophe N; Crassous, Jérôme J; Drechsler, Markus; Gaboriaud, Fabien; Eloy, Marie; de Gaudemaris, Benoît; Duval, Jérôme F L

    2013-11-26

    The interfacial structure of natural rubber (NR) colloids is investigated by means of cryogenic transmission electron microscopy (cryo-TEM) and electrokinetics over a broad range of KNO3 electrolyte concentrations (4-300 mM) and pH values (1-8). The asymptotic plateau value reached by NR electrophoretic mobility (μ) in the thin double layer limit supports the presence of a soft (ion- and water-permeable) polyelectrolytic type of layer located at the periphery of the NR particles. This property is confirmed by the analysis of the electron density profile obtained from cryo-TEM that evidences a ∼2-4 nm thick corona surrounding the NR polyisoprene core. The dependence of μ on pH and salt concentration is further marked by a dramatic decrease of the point of zero electrophoretic mobility (PZM) from 3.6 to 0.8 with increasing electrolyte concentration in the range 4-300 mM. Using a recent theory for electrohydrodynamics of soft multilayered particles, this "anomalous" dependence of the PZM on electrolyte concentration is shown to be consistent with a radial organization of anionic and cationic groups across the peripheral NR structure. The NR electrokinetic response in the pH range 1-8 is indeed found to be equivalent to that of particles surrounded by a positively charged ∼3.5 nm thick layer (mean dissociation pK ∼ 4.2) supporting a thin and negatively charged outermost layer (0.6 nm in thickness, pK ∼ 0.7). Altogether, the strong dependence of the PZM on electrolyte concentration suggests that the electrostatic properties of the outer peripheral region of the NR shell are mediated by lipidic residues protruding from a shell containing a significant amount of protein-like charges. This proposed NR shell interfacial structure questions previously reported NR representations according to which the shell consists of either a fully mixed lipid-protein layer, or a layer of phospholipids residing exclusively beneath an outer proteic film.

  20. Advanced Microscopy of Microbial Cells

    DEFF Research Database (Denmark)

    Haagensen, Janus Anders Juul; Regenberg, Birgitte; Sternberg, Claus

    2011-01-01

    microscopy, super-resolution optical microscopy (STED, SIM, PALM) as well as atomic force microscopy and Raman spectroscopy. Using examples of bistability in microbial populations as well as biofilm development and differentiation in bacterial and yeast consortia, we demonstrate the importance of microscopy...

  1. Characterization of TEM1/endosialin in human and murine brain tumors

    International Nuclear Information System (INIS)

    Carson-Walter, Eleanor B; Walter, Kevin A; Winans, Bethany N; Whiteman, Melissa C; Liu, Yang; Jarvela, Sally; Haapasalo, Hannu; Tyler, Betty M; Huso, David L; Johnson, Mahlon D

    2009-01-01

    TEM1/endosialin is an emerging microvascular marker of tumor angiogenesis. We characterized the expression pattern of TEM1/endosialin in astrocytic and metastatic brain tumors and investigated its role as a therapeutic target in human endothelial cells and mouse xenograft models. In situ hybridization (ISH), immunohistochemistry (IH) and immunofluorescence (IF) were used to localize TEM1/endosialin expression in grade II-IV astrocytomas and metastatic brain tumors on tissue microarrays. Changes in TEM1/endosialin expression in response to pro-angiogenic conditions were assessed in human endothelial cells grown in vitro. Intracranial U87MG glioblastoma (GBM) xenografts were analyzed in nude TEM1/endosialin knockout (KO) and wildtype (WT) mice. TEM1/endosialin was upregulated in primary and metastatic human brain tumors, where it localized primarily to the tumor vasculature and a subset of tumor stromal cells. Analysis of 275 arrayed grade II-IV astrocytomas demonstrated TEM1/endosialin expression in 79% of tumors. Robust TEM1/endosialin expression occurred in 31% of glioblastomas (grade IV astroctyomas). TEM1/endosialin expression was inversely correlated with patient age. TEM1/endosialin showed limited co-localization with CD31, αSMA and fibronectin in clinical specimens. In vitro, TEM1/endosialin was upregulated in human endothelial cells cultured in matrigel. Vascular Tem1/endosialin was induced in intracranial U87MG GBM xenografts grown in mice. Tem1/endosialin KO vs WT mice demonstrated equivalent survival and tumor growth when implanted with intracranial GBM xenografts, although Tem1/endosialin KO tumors were significantly more vascular than the WT counterparts. TEM1/endosialin was induced in the vasculature of high-grade brain tumors where its expression was inversely correlated with patient age. Although lack of TEM1/endosialin did not suppress growth of intracranial GBM xenografts, it did increase tumor vascularity. The cellular localization of TEM1

  2. TEM study of amorphous alloys produced by ion implantation

    International Nuclear Information System (INIS)

    Johnson, E.; Grant, W.A.; Wohlenberg, P.; Hansen, P.; Chadderton, L.T.

    1978-01-01

    Ion implantation is a technique for introducing foreign elements into surface layers of solids. Ions, as a suitably accelerated beam, penetrate the surface, slow down by collisions with target atoms to produce a doped layer. This non-equilibrium technique can provide a wide range of alloys without the restrictions imposed by equilibrium phase diagrams. This paper reports on the production of some amorphous transition metal-metalloid alloys by implantation. Thinned foils of Ni, Fe and stainless steel were implanted at room temperature with Dy + and P + ions at doses between 10 13 - 10 17 ions/cm 2 at energies of 20 and 40 keV respectively. Transmission electron microscopy and selected area diffraction analysis were used to investigate the implanted specimens. Radial diffracted intensity measurements confirmed the presence of an amorphous implanted layer. The peak positions of the maxima are in good agreement with data for similar alloys produced by conventional techniques. Only certain ion/target combinations produce these amorphous layers. Implantations at doses lower than those needed for amorphization often result in formation of new crystalline phases such as an h.c.p. phase in nickel and a b.c.c. phase in stainless steel. (Auth.)

  3. Imaging and thickness measurement of amorphous intergranular films using TEM

    International Nuclear Information System (INIS)

    MacLaren, I.

    2004-01-01

    Fresnel fringe analysis is shown to be unreliable for grain boundaries in yttrium-doped alumina: the determined thicknesses do not agree well with those measured from high resolution transmission electron microscopy (HRTEM), the asymmetry between under- and overfocus is very large, and Fresnel fringes are sometimes shown at boundaries which contain no amorphous film. An alternative approach to the analysis of HRTEM images of grain boundary films is demonstrated: Fourier filtering is used to remove the lattice fringes from the image thereby significantly enhancing the visibility of the intergranular films. The apparent film thickness shows a discrepancy between measurements from the original HRTEM image and the filtered image. It was shown that fringe delocalisation and diffuseness of the amorphous/crystalline interfaces will lead to a significant underestimate of the thickness in unprocessed HRTEM images. In contrast to this, the average thickness can be much more accurately measured from the Fourier-filtered image, provided the boundary is oriented accurately edge-on

  4. Native oxide formation on pentagonal copper nanowires: A TEM study

    Science.gov (United States)

    Hajimammadov, Rashad; Mohl, Melinda; Kordas, Krisztian

    2018-06-01

    Hydrothermally synthesized copper nanowires were allowed to oxidize in air at room temperature and 30% constant humidity for the period of 22 days. The growth of native oxide layer was followed up by high-resolution transmission electron microscopy and diffraction to reveal and understand the kinetics of the oxidation process. Copper oxides appear in the form of differently oriented crystalline phases around the metallic core as a shell-like layer (Cu2O) and as nanoscopic islands (CuO) on the top of that. Time dependent oxide thickness data suggests that oxidation follows the field-assisted growth model at the beginning of the process, as practically immediately an oxide layer of ∼2.8 nm thickness develops on the surface. However, after this initial rapid growth, the local field attenuates and the classical parabolic diffusion limited growth plays the main role in the oxidation. Because of the single crystal facets on the side surface of penta-twinned Cu nanowires, the oxidation rate in the diffusion limited regime is lower than in polycrystalline films.

  5. TEM studies of the crystal growth of indanthrone pigments

    International Nuclear Information System (INIS)

    McHendry, P.

    1998-01-01

    The aim of this work was to study the crystal growth of indanthrone during the pigmentation process. The colouring properties of a pigment are dependant on the chemical and crystallographic structure of the pigment. However, other factors are known to affect these properties including particle size, particle size distribution and level of dispersion in the chosen application medium. The parameters which affect the growth of the pigment particles were investigated with the emphasis placed on the mechanism by which growth took place. The final form of the crystals after growth was also investigated in some detail. Various electron microscopy techniques were employed in the investigations in this thesis. High and low magnification imaging and diffraction were studied on the CTEM (conventional transmission electron microscope) whilst PEELS (parallel electron energy loss spectroscopy) and DPC (differential phase contrast) studies took place on the VG HB5 STEM (scanning transmission electron microscope). In addition to these studies, x-ray diffraction and surface area analysis techniques were employed. The low magnification CTEM work gave good information on the size, shape and size distribution of the pigment particles and enabled detailed analysis of the level of growth attained under varied reaction conditions. (author)

  6. Photoluminescence and TEM evaluations of defects generated during SiGe-on-insulator virtual substrate fabrication: Temperature ramping process

    International Nuclear Information System (INIS)

    Wang, D.; Ii, S.; Ikeda, K.; Nakashima, H.; Matsumoto, K.; Nakamae, M.; Nakashima, H.

    2006-01-01

    Crystal qualities were evaluated by photoluminescence (PL) and transmission electron microscopy (TEM) for cap-Si/SiGe/Si-on-insulater (SOI) structure, which is the typical structure for SiGe-on-insulator virtual substrate fabrication using the Ge condensation by dry oxidation. The thicknesses of cap-Si, SOI and BOX layers are 10, 70, and 140 nm, respectively. We have three kinds of wafers with SiGe thicknesses of 74, 154 and 234 nm. All of the wafers were heated from 200 deg.C to a target temperature (T t ) in the range of 820-1200 deg. C with a ramping rate of 5 deg. C/min, and maintained at T t for 10 min. The air in the furnace was a mixture of O 2 and N 2 . The PL measurements were carried out using a 325 nm UV line of a continuous-wave HeCd laser. Free exciton peaks were clearly observed for the as-grown wafers and decreased with an increase in the annealing temperature. For the selected wafers, cross-sectional and plan-view TEM measurements show clear generation and variation of dislocations at the interface of SiGe/SOI according to the T t . Defect-related PL signals were observed at around 0.82, 0.88, 0.95 and 1.0 eV, which also varied according to the T t and the SiGe thickness. They were identified to dislocation-related and stacking-fault-related defects by TEM

  7. Sub-surface microstructure of single and polycrystalline tungsten after high flux plasma exposure studied by TEM

    Energy Technology Data Exchange (ETDEWEB)

    Dubinko, A., E-mail: adubinko@sckcen.be [Institute for Nuclear Material Sciences, SCK-CEN, 2400 Mol (Belgium); Department of Applied Physics, Ghent University, 9000 Ghent (Belgium); Terentyev, D. [Institute for Nuclear Material Sciences, SCK-CEN, 2400 Mol (Belgium); Bakaeva, A. [Institute for Nuclear Material Sciences, SCK-CEN, 2400 Mol (Belgium); Department of Applied Physics, Ghent University, 9000 Ghent (Belgium); Hernández-Mayoral, M. [Division of Materials, CIEMAT, 28040 Madrid (Spain); De Temmerman, G. [ITER Organization, Route de Vinon-sur-Verdon, CS 90 046, 13067 St Paul-lez-Durance Cedex (France); Buzi, L. [Forschungszentrum Julich, Inst. Energie & Klimaforsch Plasmaphys, D-52425 Julich (Germany); Noterdaeme, J.-M. [Department of Applied Physics, Ghent University, 9000 Ghent (Belgium); Unterberg, B. [Forschungszentrum Julich, Inst. Energie & Klimaforsch Plasmaphys, D-52425 Julich (Germany)

    2017-01-30

    Highlights: • Plasma exposure induces dislocation-dominated microstructure as indicated by TEM. • Plasma exposure increases surface dislocation density by an order of magnitude in the polycrystalline tungsten. • Intensive dislocation-grain boundary interaction observed in polycrystalline tungsten. • Dislocation loops are observed in both polycrystalline and single crystal tungsten. - Abstract: We have performed high flux plasma exposure of tungsten and subsequent microstructural characterization using transmission electron microscopy (TEM) techniques. The aim was to reveal the nanometric features in the sub-surface region as well as to compare the microstructural evolution in tungsten single crystal and ITER-relevant specification. In both types of samples, TEM examination revealed the formation of a dense dislocation network and dislocation tangles. The estimated dislocation density in the sub-surface region was of the order of 10{sup 14} m{sup −2} and it gradually decreased with a depth position of the examined sample. Besides individual dislocation lines, networks and tangles, the interstitial dislocation loops have been observed in all examined samples only after the exposure. Contrary to that, examination of the pristine single crystal W and backside of the plasma-exposed samples did not reveal the presence of dislocation loops and tangles. This clearly proves that high flux plasma exposure induces severe plastic deformation in the sub-surface region irrespective of the presence of initial dislocations and sub-grains, and the formation of dislocation tangles, networks and interstitial loops is a co-product of thermal stress and intensive plasma particles uptake.

  8. Investigation of ceramic devices by analytical electron microscopy techniques

    International Nuclear Information System (INIS)

    Shiojiri, M.; Saijo, H.; Isshiki, T.; Kawasaki, M.; Yoshioka, T.; Sato, S.; Nomura, T.

    1999-01-01

    Ceramics are widely used as capacitors and varistors. Their electrical properties depend on the structure, which is deeply influenced not only by the composition of raw materials and additives but also by heating treatments in the production process. This paper reviews our investigations of SrTiO 3 ceramic devices, which have been performed using various microscopy techniques such as high-resolution transmission electron microscopy (HRTEM), cathodoluminescence scanning electron microscopy (CLSEM), field emission SEM (FE-SEM), energy dispersive X-ray spectroscopy (EDS), electron energy-loss spectroscopy (EELS) and high angle annular dark field (HAADF) imaging method in a FE-(scanning) transmission electron microscope(FE-(S)TEM). (author)

  9. Electron microscopy methods in studies of cultural heritage sites

    Energy Technology Data Exchange (ETDEWEB)

    Vasiliev, A. L., E-mail: a.vasiliev56@gmail.com; Kovalchuk, M. V.; Yatsishina, E. B. [National Research Centre “Kurchatov Institute” (Russian Federation)

    2016-11-15

    The history of the development and application of scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray microanalysis (EDXMA) in studies of cultural heritage sites is considered. In fact, investigations based on these methods began when electron microscopes became a commercial product. Currently, these methods, being developed and improved, help solve many historical enigmas. To date, electron microscopy combined with microanalysis makes it possible to investigate any object, from parchment and wooden articles to pigments, tools, and objects of art. Studies by these methods have revealed that some articles were made by ancient masters using ancient “nanotechnologies”; hence, their comprehensive analysis calls for the latest achievements in the corresponding instrumental methods and sample preparation techniques.

  10. Bauxite and bauxite residue, characterization and electron microscopy study

    International Nuclear Information System (INIS)

    Antunes, M.L.P.; Conceicao, F.T.; Toledo, S.P.; Kiyohara, P.K.

    2012-01-01

    Through the Bayer process, bauxite is refined and alumina is produced. In this process, a highly alkaline residue, red mud is generated and its disposal represents an environmental problem. The aim of this paper is to present the characterization of Brazilian bauxite and Brazilian red mud by: X-ray diffraction, specific surface area, chemical composition analysis by ICP-MS, transmission electron microscopy (TEM) and energy dispersive X-ray spectrometry (EDS), and scanning electron microscopy (SEM) and discuss possible applications of this residue. The results identify as a constituent of both materials: Al 2 O 3 , Fe 2 O 3 , TiO 2 and SiO 2 and the presence of Na 2 O in residue. The analysis by electron microscopy of Bauxite shows particles with hexagonal shape and red mud shows small particles size. (author)

  11. Electron microscopy methods in studies of cultural heritage sites

    Science.gov (United States)

    Vasiliev, A. L.; Kovalchuk, M. V.; Yatsishina, E. B.

    2016-11-01

    The history of the development and application of scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray microanalysis (EDXMA) in studies of cultural heritage sites is considered. In fact, investigations based on these methods began when electron microscopes became a commercial product. Currently, these methods, being developed and improved, help solve many historical enigmas. To date, electron microscopy combined with microanalysis makes it possible to investigate any object, from parchment and wooden articles to pigments, tools, and objects of art. Studies by these methods have revealed that some articles were made by ancient masters using ancient "nanotechnologies"; hence, their comprehensive analysis calls for the latest achievements in the corresponding instrumental methods and sample preparation techniques.

  12. Electron microscopy methods in studies of cultural heritage sites

    International Nuclear Information System (INIS)

    Vasiliev, A. L.; Kovalchuk, M. V.; Yatsishina, E. B.

    2016-01-01

    The history of the development and application of scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy-dispersive X-ray microanalysis (EDXMA) in studies of cultural heritage sites is considered. In fact, investigations based on these methods began when electron microscopes became a commercial product. Currently, these methods, being developed and improved, help solve many historical enigmas. To date, electron microscopy combined with microanalysis makes it possible to investigate any object, from parchment and wooden articles to pigments, tools, and objects of art. Studies by these methods have revealed that some articles were made by ancient masters using ancient “nanotechnologies”; hence, their comprehensive analysis calls for the latest achievements in the corresponding instrumental methods and sample preparation techniques.

  13. Polycrystalline oxides formation during transient oxidation of (001) Cu-Ni binary alloys studied by in situ TEM and XRD

    International Nuclear Information System (INIS)

    Yang, J.C.; Li, Z.Q.; Sun, L.; Zhou, G.W.; Eastman, J.A.; Fong, D.D.; Fuoss, P.H.; Baldo, P.M.; Rehn, L.E.; Thompson, L.J.

    2009-01-01

    The nucleation and growth of Cu 2 O and NiO islands due to oxidation of Cu x Ni 1-x (001) films were monitored, at various temperatures, by in situ ultra-high vacuum (UHV) transmission electron microscopy (TEM) and in situ synchrotron X-ray diffraction (XRD). In remarkable contrast to our previous observations of Cu and Cu-Au oxidation, irregular-shaped polycrystalline oxide islands formed with respect to the Cu-Ni alloy film, and an unusual second oxide nucleation stage was noted. In situ XRD experiments revealed that NiO formed first epitaxially, then other orientations appeared, and finally polycrystalline Cu 2 O developed as the oxidation pressure was increased. The segregation of Ni and Cu towards or away, respectively, from the alloy surface during oxidation could disrupt the surface and cause polycrystalline oxide formation.

  14. Problems at the Leading Edge of Space Weathering as Revealed by TEM Combined with Surface Science Techniques

    Science.gov (United States)

    Christoffersen, R.; Dukes, C. A.; Keller, L. P.; Rahman, Z.; Baragiola, R. A.

    2015-01-01

    Both transmission electron micros-copy (TEM) and surface analysis techniques such as X-ray photoelectron spectroscopy (XPS) were instrumen-tal in making the first characterizations of material generated by space weathering in lunar samples [1,2]. Without them, the nature of nanophase metallic Fe (npFe0) correlated with the surface of lunar regolith grains would have taken much longer to become rec-ognized and understood. Our groups at JSC and UVa have been using both techniques in a cross-correlated way to investigate how the solar wind contributes to space weathering [e.g., 3]. These efforts have identified a number of ongoing problems and knowledge gaps. Key insights made by UVa group leader Raul Barag-iola during this work are gratefully remembered.

  15. Report on the Installation and Preparedness of a Protochips Fusion in-situ Heating Holder for TEM

    Energy Technology Data Exchange (ETDEWEB)

    Edmondson, Philip D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-03-01

    This brief report documents the procurement and installation of a Protochips Fusion (formerly Aduro) high-temperature, high stability transmission electron microscopy (TEM) specimen holder that allows for the high spatial resolution characterization of material specimens at high temperature in situ of an electron microscope. This specimen holder was specifically procured for use with The FEI Talos F200X Scanning/Transmission Electron Microscope (STEM) in Oak Ridge National Laboratory’s (ORNL’s) Low Activation Materials Development and Analysis (LAMDA) Laboratory. The Protochips Fusion holder will enable high-resolution structural and chemical analysis of irradiated materials at high temperature, becoming a unique capability worldwide, and would encourage high-quality in situ experiments to be conducted on irradiated materials.

  16. INVESTIGATION ON THE MORPHOLOGY AND PROPERTIES OF AGGREGATE STRUCTURES OF NATURAL PHOSPHOLIPIDS IN AQUEOUS SYSTEM USING CRYO-TEM

    Directory of Open Access Journals (Sweden)

    Dwi Hudiyanti

    2012-02-01

    Full Text Available Cryogenic transmission electron microscopy (Cryo-TEM was used to investigate the aggregates morphology and properties of candle tree (Aleurites moluccana endosperm, sesame (Sesamum indicum L. syn. seeds, and coconut (Cocos nucifera endosperm phospholipids in dilute aqueous system. The micrographs showed that candle tree phospholipids formed planar bilayer and cluster of vesicles with lipid droplets, while coconut and sesame phospholipids formed well-defined unilamellar vesicles. The vesicles size could be as small as 50 nm in diameter. Coconut phospholipids also showed a good bending ability. Formation of clusters of vesicles was also found in coconut phospholipids dispersion, but this cluster was easily broken by extrusion through a small pore membrane.

  17. SEM, TEM, and IHC Analysis of the Sinus Node and Its Implications for the Cardiac Conduction System

    Directory of Open Access Journals (Sweden)

    D. Mandrioli

    2013-01-01

    Full Text Available More than 100 years after the discovery of the sinus node (SN by Keith and Flack, the function and structure of the SN have not been completely established yet. The anatomic architecture of the SN has often been described as devoid of an organized structure; the origin of the sinus impulse is still a matter of debate, and a definite description of the long postulated internodal specialized tract conducting the impulse from the SN to the atrioventricular node (AVN is still missing. In our previously published study, we proposed a morphologically ordered structure for the SN. As a confirmation of what was presented then, we have added the results of additional observations regarding the structural particularities of the SN. We investigated the morphology of the sinus node in the human hearts of healthy individuals using histochemical, immunohistochemical, optical, and electron microscopy (SEM, TEM. Our results confirmed that the SN presents a previously unseen highly organized architecture.

  18. A study on the microstructure of Pt/TaN/Si films by high resolution TEM analysis

    CERN Document Server

    Cho, K N; Oh, J E; Park, C S; Lee, S I; Lee, M Y

    1998-01-01

    The microstructure change of Pt/amorphous TaN/Si films after various heat treatments has been investigated by high resolution transmission electron microscopy (HR-TEM) analysis. TaN thin films are deposited by remote plasma metalorganic chemical vapor deposition (RP-MOCVD) using pentakis-dimethyl-amino-tantalum (PDMATa) and radical sources, hydrogen and ammonia plasma. Deposited TaN thin film shows excellent barrier properties such as good resistance against oxidation after post-heat treatment at high temperature. In the case of hydrogen plasma, however, diffusion of Pt into TaN layer was observed, which was caused by the out-diffusion of carbon through the grain boundaries of Pt. In the case of ammonia plasma, the formation of thin oxide layer at the Pt/TaN interface was observed.

  19. Second harmonic generation microscopy

    DEFF Research Database (Denmark)

    Brüggemann, Dagmar Adeline; Brewer, Jonathan R.; Risbo, Jens

    2010-01-01

    Myofibers and collagen show non-linear optical properties enabling imaging using second harmonic generation (SHG) microscopy. The technique is evaluated for use as a tool for real-time studies of thermally induced changes in thin samples of unfixed and unstained pork. The forward and the backward...... scattered SHG light reveal complementary features of the structures of myofibers and collagen fibers. Upon heating the myofibers show no structural changes before reaching a temperature of 53 °C. At this temperature the SHG signal becomes extinct. The extinction of the SHG at 53 °C coincides with a low......-temperature endotherm peak observable in the differential scanning calorimetry (DSC) thermograms. DSC analysis of epimysium, the connective tissue layer that enfold skeletal muscles, produces one large endotherm starting at 57 °C and peaking at 59.5 °C. SHG microscopy of collagen fibers reveals a variability of thermal...

  20. Recombination-related properties of a-screw dislocations in GaN: A combined CL, EBIC, TEM study

    Energy Technology Data Exchange (ETDEWEB)

    Medvedev, O. S., E-mail: o.s.medvedev@spbu.ru; Mikhailovskii, V. Yu. [V.A. Fok Institute of Physics, St. Petersburg State University (Russian Federation); IRC for Nanotechnology, Research Park, St.-Petersburg State University (Russian Federation); Vyvenko, O. F.; Bondarenko, A. S.; Ubyivovk, E. V. [V.A. Fok Institute of Physics, St. Petersburg State University (Russian Federation); Peretzki, P.; Seibt, M. [IV. Physikalisches Institut Georg-August Universität Göttingen (Germany)

    2016-06-17

    Cathodoluminescence (CL), electron beam current (EBIC) and transmission electron microscopy (TEM) techniques have been applied to investigate recombination properties and structure of freshly introduced dislocations in low-ohmic GaN crystals. It was confirmed that the only a-screw dislocations exhibited an intense characteristic dislocation-related luminescence (DRL) which persisted up to room temperature and was red-shifted by about 0.3 eV with respect to the band gap energy not only in HVPE but also in MOCVD grown samples. EBIC contrast of the dislocations was found to be temperature independent indicating that the dislocation-related recombination level is situated below 200 meV with respect of conduction band minimum. With the increasing of the magnification of the dislocation TEM cross-sectional images they were found to disappear, probably, due to the recombination enhanced dislocation glide (REDG) under electron beam exposure which was immediately observed in CL investigations on a large scale. The stacking fault ribbon in the core of dissociated a-screw dislocation which form a quantum well for electrons was proposed to play an important role both in DRL spectrum formation and in REDG.

  1. From Nanoparticles to Process An Aberration Corrected TEM Study of Fischer Tropsch Catalysts at Various Steps of the Process

    International Nuclear Information System (INIS)

    Braidy, N.; Blanchard, J.; Abatzoglou, N.; Andrei, C.

    2011-01-01

    χThe nanostructure of Fischer-Tropsch (FT) Fe carbides are investigated using aberration-corrected high-resolution transmission electron microscopy (TEM). The plasma-generated Fe carbides are analyzed just after synthesis, following reduction via a H2 treatment step and once used as FT catalyst and deactivated. The as-produced nanoparticles (NPs) are seen to be abundantly covered with graphitic and amorphous carbon. Using the extended information limit from the spherical aberration-corrected TEM, the NPs could be indexed as a mixture of NPs in the θ-Fe 3 C and χ-Fe 5 C 2 phases. The reduction treatment exposed the NPs by removing most of the carbonaceous speSubscript textcies while retaining the χ-Fe 5 C 2 . Fe-carbides NPs submitted to conditions typical to FT synthesis develop a Fe3O4 shell which eventually consumes the NPs up to a point where 3-4 nm residual carbide is left at the center of the particle. Subscript textVarious mechanisms explaining the formation of such a microstructure are discussed. (author)

  2. Electron microscopy and diffraction

    International Nuclear Information System (INIS)

    Gjoennes, J.; Olsen, A.

    1986-01-01

    This report is a description of research activities and plans at the electron microscopy laboratorium, Physics Department, University of Oslo. Since the first electron microscope was installed in 1968, the research has covered inorganic structures, physical metallurgy, as well as theory of electron scattering and the development of methods in this field. The current plans involve efforts in the development of crystallographic and spectroscopic methods

  3. Deep Learning Microscopy

    KAUST Repository

    Rivenson, Yair

    2017-05-12

    We demonstrate that a deep neural network can significantly improve optical microscopy, enhancing its spatial resolution over a large field-of-view and depth-of-field. After its training, the only input to this network is an image acquired using a regular optical microscope, without any changes to its design. We blindly tested this deep learning approach using various tissue samples that are imaged with low-resolution and wide-field systems, where the network rapidly outputs an image with remarkably better resolution, matching the performance of higher numerical aperture lenses, also significantly surpassing their limited field-of-view and depth-of-field. These results are transformative for various fields that use microscopy tools, including e.g., life sciences, where optical microscopy is considered as one of the most widely used and deployed techniques. Beyond such applications, our presented approach is broadly applicable to other imaging modalities, also spanning different parts of the electromagnetic spectrum, and can be used to design computational imagers that get better and better as they continue to image specimen and establish new transformations among different modes of imaging.

  4. OSCE vs. TEM: Different approaches to assess clinical skills of nursing students

    Directory of Open Access Journals (Sweden)

    Prasuna Jelly

    2017-01-01

    Full Text Available Introduction: Nurses are trained with specific clinical skills, and objective structured clinical examination (OSCE could be a better approach to assess clinical skills of nursing students. Materials and Methods: A comparative study was conducted by observational checklist regarding antenatal care and opinionnaire on the usefulness of OSCE and tradition evaluation method (TEM was used to assess the clinical skills and to get opinion. Results: The mean score of OSCE was more than TEM and the difference was statistically significant (P < 0.001. The opinion of students regarding the usefulness of OSCE was higher than TEM. Conclusions: The study concluded that implementing OSCE will overweigh the advantages of the TEM.

  5. Retrofit implementation of Zernike phase plate imaging for cryo-TEM.

    Science.gov (United States)

    Marko, Michael; Leith, Ardean; Hsieh, Chyongere; Danev, Radostin

    2011-05-01

    In-focus phase-plate imaging is particularly beneficial for cryo-TEM because it offers a substantial overall increase in image contrast, without an electron dose penalty, and it simplifies image interpretation. We show how phase-plate cryo-TEM can be implemented with an appropriate existing TEM, and provide a basic practical introduction to use of thin-film (carbon) phase plates. We point out potential pitfalls of phase-plate operation, and discuss solutions. We provide information on evaluating a particular TEM for its suitability. Copyright © 2011 Elsevier Inc. All rights reserved.

  6. Investigation of diversity of plasmids carrying the blaTEM-52 gene

    DEFF Research Database (Denmark)

    Bielak, Eliza Maria; Bergenholtz, Rikke D.; Jørgensen, Mikael Skaanning

    2011-01-01

    OBJECTIVES: To investigate the diversity of plasmids that carry blaTEM-52 genes among Escherichia coli and Salmonella enterica originating from animals, meat products and humans. METHODS: A collection of 22 blaTEM-52-encoding plasmids was characterized by restriction fragment length polymorphism...... of self-transfer to a plasmid-free E. coli recipient. CONCLUSIONS: The blaTEM-52 gene found in humans could have been transmitted on transferable plasmids originating from animal sources. Some of the blaTEM-52 plasmids carry replicons that differ from the classical ones. Two novel replicons were detected...

  7. Fast FIB-milled Electron-transparent Microchips for in situ TEM Investigations

    DEFF Research Database (Denmark)

    Lei, Anders; Petersen, Dirch Hjorth; Kallesøe, Christian

    In this work we present a fast approach to 50 nm resolution structures defined in a generic TEM-chip template in few minutes. While creating complex electrical and NEMS circuits for a specific insitu TEM experiment can be a cumbersome process, microchips with 100 nm thin flakes of single crystall......In this work we present a fast approach to 50 nm resolution structures defined in a generic TEM-chip template in few minutes. While creating complex electrical and NEMS circuits for a specific insitu TEM experiment can be a cumbersome process, microchips with 100 nm thin flakes of single...

  8. Identification of proangiogenic TIE2-expressing monocytes (TEMs) in human peripheral blood and cancer.

    Science.gov (United States)

    Venneri, Mary Anna; De Palma, Michele; Ponzoni, Maurilio; Pucci, Ferdinando; Scielzo, Cristina; Zonari, Erika; Mazzieri, Roberta; Doglioni, Claudio; Naldini, Luigi

    2007-06-15

    Tumor-infiltrating myeloid cells, including tumor-associated macrophages (TAMs), have been implicated in tumor progression. We recently described a lineage of mouse monocytes characterized by expression of the Tie2 angiopoietin receptor and required for the vascularization and growth of several tumor models. Here, we report that TIE2 expression in human blood identifies a subset of monocytes distinct from classical inflammatory monocytes and comprised within the less abundant "resident" population. These TIE2-expressing monocytes (TEMs) accounted for 2% to 7% of blood mononuclear cells in healthy donors and were distinct from rare circulating endothelial cells and progenitors. In human cancer patients, TEMs were observed in the blood and, intriguingly, within the tumors, where they represented the main monocyte population distinct from TAMs. Conversely, TEMs were hardly detected in nonneoplastic tissues. In vitro, TEMs migrated toward angiopoietin-2, a TIE2 ligand released by activated endothelial cells and angiogenic vessels, suggesting a homing mechanism for TEMs to tumors. Purified human TEMs, but not TEM-depleted monocytes, markedly promoted angiogenesis in xenotransplanted human tumors, suggesting a potentially critical role of TEMs in human cancer progression. Human TEMs may provide a novel, biologically relevant marker of angiogenesis and represent a previously unrecognized target of cancer therapy.

  9. The mandibular ridge oral mucosa model of stromal influences on the endothelial tip cells: an immunohistochemical and TEM study.

    Science.gov (United States)

    Rusu, Mugurel Constantin; Didilescu, Andreea Cristiana; Stănescu, Ruxandra; Pop, Florinel; Mănoiu, Valentina Mariana; Jianu, Adelina Maria; Vâlcu, Marek

    2013-02-01

    This study aimed to evaluate by immunohistochemistry and transmission electron microscopy (TEM) the morphological features of the oral mucosa endothelial tip cells (ETCs) and to determine the immune and ultrastructural patterns of the stromal nonimmune cells which could influence healing processes. Immune labeling was performed on bioptic samples obtained from six edentulous patients undergoing surgery for dental implants placement; three normal samples were collected from patients prior to the extraction of the third mandibular molar. The antibodies were tested for CD34, CD117(c-kit), platelet derived growth factor receptor-alpha (PDGFR-α), Mast Cell Tryptase, CD44, vimentin, CD45, CD105, alpha-smooth muscle actin, FGF2, Ki67. In light microscopy, while stromal cells (StrCs) of the reparatory and normal oral mucosa, with a fibroblastic appearance, were found positive for a CD34/CD44/CD45/CD105/PDGFR-α/vimentin immune phenotype, the CD117/c-kit labeling led to a positive stromal reaction only in the reparatory mucosa. In TEM, non-immune StrCs presenting particular ultrastructural features were identified as circulating fibrocytes (CFCs). Within the lamina propria CFCs were in close contact with ETCs. Long processes of the ETCs were moniliform, and hook-like collaterals were arising from the dilated segments, suggestive for a different stage migration. Maintenance and healing of oral mucosa are so supported by extensive processes of angiogenesis, guided by ETCs that, in turn, are influenced by the CFCs that populate the stromal compartment both in normal and reparatory states. Therefore, CFCs could be targeted by specific therapies, with pro- or anti-angiogenic purposes. Copyright © 2012 Wiley Periodicals, Inc.

  10. Comparison of ultramicrotomy and focused-ion-beam for the preparation of TEM and STEM cross section of organic solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Corazza, Michael, E-mail: michael.corazza@gmail.com [Department of Energy Conversion and Storage, Technical University of Denmark, Frederiksborgvej 399, 4000 Roskilde (Denmark); Simonsen, Søren B. [Department of Energy Conversion and Storage, Technical University of Denmark, Frederiksborgvej 399, 4000 Roskilde (Denmark); Gnaegi, Helmut [Diatome Ltd., Biel-Bienne (Switzerland); Thydén, Karl T.S.; Krebs, Frederik C.; Gevorgyan, Suren A. [Department of Energy Conversion and Storage, Technical University of Denmark, Frederiksborgvej 399, 4000 Roskilde (Denmark)

    2016-12-15

    Highlights: • Comparison of flexible solar cell sections prepared by ultramicrotomy and by FIB. • Energy filtered TEM analysis of phase separation in the P3HT:PCBM active layer. • Imaging of aging effects on solar cell cross section prepared by ultramicrotomy. • Ultramicrotomy provides great details while FIB better preserves the structure. - Abstract: The challenge of preparing cross sections of organic photovoltaics (OPV) suitable for transmission electron microscopy (TEM) and scanning TEM (STEM) is addressed. The samples were polymer solar cells fabricated using roll-to-roll (R2R) processing methods on a flexible polyethylene terephthalate (PET) substrate. Focused ion beam (FIB) and ultramicrotomy were used to prepare the cross sections. The differences between the samples prepared by ultramicrotomy and FIB are addressed, focusing on the advantages and disadvantages of each technique. The sample prepared by ultramicrotomy yielded good resolution, enabling further studies of phase separation of P3HT:PCBM by means of energy filtered TEM (EFTEM). The sample prepared by FIB shows good structure preservation, but reduced resolution due to non-optimal thicknesses achieved after treatment. Degradation studies of samples prepared by ultramicrotomy are further discussed, which reveal particular effects of the ISOS-L-3 aging test (85 °C, 50% R.H., 0.7 Sun) onto the sample, especially pronounced in the silver layer.

  11. Measurement and correlation of optical and TEM twins in Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7-δ/

    International Nuclear Information System (INIS)

    Chumbley, L.S.; Verhoeven, J.D.; Kim, M.R.; Cornelius, A.L.; Kramer, M.J.

    1989-01-01

    The spacing of the twins present in Y/sub 1/Ba/sub 2/Cu/sub 3/O/sub 7-δ/ has been investigated using optical and Transmission Electron Microscopy (TEM). Studies have reported that the value of the average twin spacing obtained by optical measurements is much larger than that measured in thin foils prepared for TEM observation, and controversy exists as to the exact nature of the optical twins. Experiments have been conducted which show that the twins observed optically correspond to those seen using TEM and are not produced by an optical interference effect. Using electron channeling, equations have been formulated which allow optical determination of the true spacing of twins present in a selected grain as well as the orientation of that grain. The average twin spacing measured in TEM has been found to vary with sample preparation method, being smaller for crushed chip samples than for bulk samples prepared by ion milling or jet-polishing. A variation of the twin spacing with grain size has also been noted

  12. In Situ Electron Microscopy of Lactomicroselenium Particles in Probiotic Bacteria

    Directory of Open Access Journals (Sweden)

    Gabor Nagy

    2016-06-01

    Full Text Available Electron microscopy was used to test whether or not (a in statu nascendi synthesized, and in situ measured, nanoparticle size does not differ significantly from the size of nanoparticles after their purification; and (b the generation of selenium is detrimental to the bacterial strains that produce them. Elemental nano-sized selenium produced by probiotic latic acid bacteria was used as a lactomicroselenium (lactomicroSel inhibitor of cell growth in the presence of lactomicroSel, and was followed by time-lapse microscopy. The size of lactomicroSel produced by probiotic bacteria was measured in situ and after isolation and purification. For these measurements the TESLA BS 540 transmission electron microscope was converted from analog (aTEM to digital processing (dTEM, and further to remote-access internet electron microscopy (iTEM. Lactobacillus acidophilus produced fewer, but larger, lactomicroSel nanoparticles (200–350 nm than Lactobacillus casei (L. casei, which generated many, smaller lactomicroSel particles (85–200 nm and grains as a cloudy, less electrodense material. Streptococcus thermophilus cells generated selenoparticles (60–280 nm in a suicidic manner. The size determined in situ in lactic acid bacteria was significantly lower than those measured by scanning electron microscopy after the isolation of lactomicroSel particles obtained from lactobacilli (100–500 nm, but higher relative to those isolated from Streptococcus thermopilus (50–100 nm. These differences indicate that smaller lactomicroSel particles could be more toxic to the producing bacteria themselves and discrepancies in size could have implications with respect to the applications of selenium nanoparticles as prebiotics.

  13. The potentials and challenges of electron microscopy in the study of atomic chains

    Science.gov (United States)

    Banhart, Florian; Torre, Alessandro La; Romdhane, Ferdaous Ben; Cretu, Ovidiu

    2017-04-01

    The article is a brief review on the potential of transmission electron microscopy (TEM) in the investigation of atom chains which are the paradigm of a strictly one-dimensional material. After the progress of TEM in the study of new two-dimensional materials, microscopy of free-standing one-dimensional structures is a new challenge with its inherent potentials and difficulties. In-situ experiments in the TEM allowed, for the first time, to generate isolated atomic chains consisting of metals, carbon or boron nitride. Besides having delivered a solid proof for the existence of atomic chains, in-situ TEM studies also enabled us to measure the electrical properties of these fundamental linear structures. While ballistic quantum conductivity is observed in chains of metal atoms, electrical transport in chains of sp1-hybridized carbon is limited by resonant states and reflections at the contacts. Although substantial progress has been made in recent TEM studies of atom chains, fundamental questions have to be answered, concerning the structural stability of the chains, bonding states at the contacts, and the suitability for applications in nanotechnology. Contribution to the topical issue "The 16th European Microscopy Congress (EMC 2016)", edited by Richard Brydson and Pascale Bayle-Guillemaud

  14. TEM validation of immunohistochemical staining prior to assessment of tumour angiogenesis by computerised image analysis

    International Nuclear Information System (INIS)

    Killingsworth, M.C.

    2002-01-01

    Full text: Counts of microvessel density (MVD) within solid tumours have been shown to be an independent predictor of outcome with higher counts generally associated with a worse prognosis. These assessments are commonly performed on immunoperoxidase stained (IPX) sections with antibodies to CD34, CD31 and Factor VIII-related antigen routinely used as vascular markers. Tumour vascular density is thought to reflect the demand the growing neoplasm is placing on its feeding blood supply. Vascular density also appears to be associated with spread of invasive cells to distant sites. The present study of tumour angiogenesis in prostate cancer specimens aims to assess new vessel growth in addition to MVD counts. The hypothesis being that an assessment which takes into account vascular migration and proliferation as well as the number of patent vessels present may have improved predictive power over assessments based on MVD counts alone. We are employing anti-CD34 stained IPX sections which are digitally photographed and assessed by a computerised image analysis system. Our aim is to develop parameters whereby tumour angiogenesis may be assessed at the light microscopic level and then correlated with existing histological methods of tumour assessment such as Gleason grading. In order to use IPX stained sections for angiogenic assessment validation and understanding of the anti-CD34 immunostaining pattern was necessary. This involved the following steps: i) Morphological assessment of angiogenic changes present in tumour blood vessels. Morphological changes in endothelial cells and pericytes indicative of angiogenic activation are generally below the level of resolution available with light microscopy. TEM examination revealed endothelial cell budding, pericyte retraction, basement membrane duplication and endothelial sprout formation in capillaries and venules surrounding tumour glands. This information assisted with the development of parameters by which IPX sections

  15. On the way to high resolution TEM characterization of dual ion beam irradiated ODS steels

    International Nuclear Information System (INIS)

    Hsiung, L.; Tumey, S.; Fluss, M. J.; King, W.; Marian, J.; Kuntz, J.; Dasher, B. El; Serruys, Y.; Willaime, F.; Kimura, A.

    2009-01-01

    Fission and fusion energy application of ODS steels while appearing promising requires that many key science issues be resolved. Among these issues are our incomplete understanding of the effect of irradiation on low-temperature fracture properties, the role of fusion relevant helium and hydrogen transmutation gases on the deformation and fracture of irradiated material at low and high temperatures, radiation-induced solute segregation and phase stability, mechanisms of swelling suppression in ODS steels, and the effects of radiation damage on localized deformation. While planning to focus on all these issues we are particularly interested in the atomic scale mechanism by which helium is mitigated by the nano scale particles. In order to obtain insight we are performing analytical transmission electron microscopy (AEM), high resolution electron microscopy (HRTEM) to investigate micro-structural and micro-compositional changes and property alterations of Fe-Cr ferritic/martensitic and ODS steels driven by temperature and ion-beam irradiation with Fe, H, and He. As a beginning to a collaboration between LLNL and CEA-Saclay, we have carried out an irradiation of four specimens, Fe, Fe14%Cr, and two ODS steels (14% Cr and 16% Cr) using the dual beam facility at CEA-Saclay (JANNuS). An Fe 8+ beam was implanted at 24 MeV and helium was implanted through a degrader wheel with energies between 1.7 MeV and 1.3 MeV. The nominal radiation parameters were 40 to 25 DPA, 10 to 25 appm He/DPA ratio, and specimen temperatures of ∼425 deg. C. Our goal is to compare the evolved microstructure with respect to the accumulation of helium at or near the particle matrix interface. Preparatory to this first study we have made many hi-resolution analyses of the nano-particles in the two ODS steels which serve as a base line for comparison with the TEM post irradiation examination reported here. These base line studies are reported separately at this conference. (author)

  16. TEM characterization of irradiated U-7Mo/Mg dispersion fuel

    Science.gov (United States)

    Gan, J.; Keiser, D. D.; Miller, B. D.; Jue, J. F.; Robinson, A. B.; Madden, J.

    2017-10-01

    This paper presents the results of transmission electron microscopy (TEM) characterization on neutron-irradiated samples taken from the low-flux and high-flux sides of the same fuel plate with U-7Mo fuel particles dispersed in Mg matrix with aluminum alloy Al6061 as cladding material that was irradiated edge-on to the core in the Advanced Test Reactor. The corresponding local fission density and fission rate of the fuel particles and the average fuel-plate centerline temperature for the low-flux and high-flux samples are estimated to be 3.7 × 1021 f/cm3, 7.4 × 1014 f/cm3/s and 123 °C, and 5.5 × 1021 f/cm3, 11.0 × 1014 f/cm3/s and 158 °C, respectively. Complex interaction layers developed at the Al-Mg interface, consisting of Al3Mg2 and Al12Mg17 along with precipitates of MgO, Mg2Si and FeAl5.3. No interaction between Mg matrix and U-Mo fuel particle was identified. For the U-Mo fuel particles, at low fission density, small elongated bubbles wrapped around the clean areas with a fission gas bubble superlattice, which suggests that bubble coalescence is an important mechanism for converting the fission gas bubble superlattice to large bubbles. At high fission density, no bubbles or porosity were observed in the Mg matrix, and pockets of residual fission gas bubble superlattice were observed in the U-Mo fuel particle interior.

  17. Imaging Si nanoparticles embedded in SiO2 layers by (S)TEM-EELS

    International Nuclear Information System (INIS)

    Schamm, S.; Bonafos, C.; Coffin, H.; Cherkashin, N.; Carrada, M.; Ben Assayag, G.; Claverie, A.; Tence, M.; Colliex, C.

    2008-01-01

    Fabrication of systems in which Si nanoparticles are embedded in a thin silica layer is today mature for non-volatile memory and opto-electronics applications. The control of the different parameters (position, size and density) of the nanoparticles population is a key point to optimize the properties of such systems. A review of dedicated transmission electron microscopy (TEM) methods, which can be used to measure these parameters, is presented with an emphasis on those relying on electron energy-loss spectroscopy (EELS). Defocused bright-field imaging can be used in order to determine topographic information of a whole assembly of nanoparticles, but it is not efficient for looking at individual nanoparticles. High-resolution electron imaging or dark-field imaging can be of help in the case of crystalline particles but they always provide underestimated values of the nanocrystals population. EELS imaging in the low-energy-loss domain around the Si plasmon peak, which gives rise to strong signals, is the only way to visualize all Si nanoparticles within a silica film and to perform reliable size and density measurements. Two complementary types of experiments are investigated and discussed more extensively: direct imaging with a transmission electron microscope equipped with an imaging filter (EFTEM) and indirect imaging from spectrum-imaging data acquired with a scanning transmission electron microscope equipped with a spectrometer (STEM-PEELS). The direct image (EFTEM) and indirect set of spectra (STEM-PEELS) are processed in order to deliver images where the contribution of the silica matrix is minimized. The contrast of the resulting images can be enhanced with adapted numerical filters for further morphometric analysis. The two methods give equivalent results, with an easier access for EFTEM and the possibility of a more detailed study of the EELS signatures in the case of STEM-PEELS. Irradiation damage in such systems is also discussed

  18. Characterization of nanomaterials with transmission electron microscopy

    KAUST Repository

    Anjum, Dalaver H.

    2016-01-01

    -Co) NPs and titania (TiO2) NPs, and platinum loaded Ceria (Pt-CeO2) Nano composite. TEM techniques that are employed to investigate nano-materials include aberration corrected bright-field TEM (BF-TEM), high-angle dark-field scanning TEM (HAADF

  19. The tetraspanin web revisited by super-resolution microscopy.

    Science.gov (United States)

    Zuidscherwoude, Malou; Göttfert, Fabian; Dunlock, Vera Marie E; Figdor, Carl G; van den Bogaart, Geert; van Spriel, Annemiek B

    2015-07-17

    The spatial organization of membrane proteins in the plasma membrane is critical for signal transduction, cell communication and membrane trafficking. Tetraspanins organize functional higher-order protein complexes called 'tetraspanin-enriched microdomains (TEMs)' via interactions with partner molecules and other tetraspanins. Still, the nanoscale organization of TEMs in native plasma membranes has not been resolved. Here, we elucidated the size, density and distribution of TEMs in the plasma membrane of human B cells and dendritic cells using dual color stimulated emission depletion (STED) microscopy. We demonstrate that tetraspanins form individual nanoclusters smaller than 120 nm and quantified that a single tetraspanin CD53 cluster contains less than ten CD53 molecules. CD53 and CD37 domains were adjacent to and displayed only minor overlap with clusters containing tetraspanins CD81 or CD82. Moreover, CD53 and CD81 were found in closer proximity to their partners MHC class II and CD19 than to other tetraspanins. Although these results indicate that tetraspanin domains are adjacently positioned in the plasma membrane, they challenge the current view of the tetraspanin web of multiple tetraspanin species organized into a single domain. This study increases the molecular understanding of TEMs at the nanoscale level which is essential for comprehending tetraspanin function in cell biology.

  20. Electron microscopy of atmospheric particles

    Science.gov (United States)

    Huang, Po-Fu

    Electron microscopy coupled with energy dispersive spectrometry (EM/EDS) is a powerful tool for single particle analysis. However, the accuracy with which atmospheric particle compositions can be quantitatively determined by EDS is often hampered by substrate-particle interactions, volatilization losses in the low pressure microscope chamber, electron beam irradiation and use of inaccurate quantitation factors. A pseudo-analytical solution was derived to calculate the temperature rise due to the dissipation of the electron energy on a particle-substrate system. Evaporative mass loss for a spherical cap-shaped sulfuric acid particle resting on a thin film supported by a TEM grid during electron beam impingement has been studied. Measured volatilization rates were found to be in very good agreement with theoretical predictions. The method proposed can also be used to estimate the vapor pressure of a species by measuring the decay of X-ray intensities. Several types of substrates were studied. We found that silver-coated silicon monoxide substrates give carbon detection limits comparable to commercially available substrates. An advantage of these substrates is that the high thermal conductivity of the silver reduces heating due to electron beam impingement. In addition, exposure of sulfuric acid samples to ammonia overnight substantially reduces sulfur loss in the electron beam. Use of size-dependent k-factors determined from particles of known compositions shows promise for improving the accuracy of atmospheric particle compositions measured by EM/EDS. Knowledge accumulated during the course of this thesis has been used to analyze atmospheric particles (Minneapolis, MN) selected by the TDMA and collected by an aerodynamic focusing impactor. 'Less' hygroscopic particles, which do not grow to any measurable extent when humidified to ~90% relative humidity, included chain agglomerates, spheres, flakes, and irregular shapes. Carbon was the predominant element detected in

  1. Advances in Transmission Electron Microscopy : In Situ Straining and In Situ Compression Experiments on Metallic Glasses

    NARCIS (Netherlands)

    De Hosson, Jeff Th. M.

    In the field of transmission electron microscopy (TEM), fundamental and practical reasons still remain that hamper a straightforward correlation between microscopic structural information and deformation mechanisms in materials. In this article, it is argued that one should focus in particular on in

  2. Anisotropic Shape Changes of Silica Nanoparticles Induced in Liquid with Scanning Transmission Electron Microscopy

    NARCIS (Netherlands)

    Zecevic, J.; Hermannsdorfer, Justus; Schuh, Tobias; de Jong, Krijn P.; de Jonge, Niels

    2017-01-01

    Liquid-phase transmission electron microscopy (TEM) is used for in-situ imaging of nanoscale processes taking place in liquid, such as the evolution of nanoparticles during synthesis or structural changes of nanomaterials in liquid environment. Here, it is shown that the focused electron beam of

  3. Nano-structured thin films : a Lorentz transmission electron microscopy and electron holography study

    NARCIS (Netherlands)

    Hosson, J.Th.M. de; Raedt, H.A. De; Zhong, ZY; Saka, H; Kim, TH; Holm, EA; Han, YF; Xie, XS

    2005-01-01

    This paper aims at applying advanced transmission electron microscopy (TEM) to functional materials, such as ultra-soft magnetic films for high-frequency inductors, to reveal the structure-property relationship. The ultimate goal is to delineate a more quantitative way to obtain information of the

  4. Electron beam fabrication and characterization of high- resolution magnetic force microscopy tips

    NARCIS (Netherlands)

    Ruhrig, M.; Rührig, M.; Porthun, S.; Porthun, S.; Lodder, J.C.; Mc vitie, S.; Heyderman, L.J.; Johnston, A.B.; Chapman, J.N.

    1996-01-01

    The stray field, magnetic microstructure, and switching behavior of high‐resolution electron beam fabricated thin film tips for magnetic force microscopy (MFM) are investigated with different imaging modes in a transmission electron microscope (TEM). As the tiny smooth carbon needles covered with a

  5. TEM Characterization of Helium Bubbles in T91 and MNHS Steels Implanted with 200 keV He Ions at Different Temperatures

    International Nuclear Information System (INIS)

    Wang Ji; Gao Xing; Wang Zhi-Guang; Wei Kong-Fang; Yao Cun-Feng; Cui Ming-Huan; Sun Jian-Rong; Li Bing-Sheng; Pang Li-Long; Zhu Ya-Bin; Luo Peng; Chang Hai-Long; Zhang Hong-Peng; Zhu Hui-Ping; Wang Dong; Du Yang-Yang; Xie Er-Qing

    2015-01-01

    Modified novel high silicon steel (MNHS, a newly developed reduced-activation martensitic alloy) and commercial alloy T91 are implanted with 200 keV He"2"+ ions to a dose of 5 × 10"2"0 ions/m"2 at 300, 450 and 550°C. Transmission electron microscopy (TEM) is used to characterize the size and morphology of He bubbles. With the increase of the implantation temperature, TEM observations indicate that bubbles increase in size and the proportion of ‘brick shaped’ cuboid bubbles increases while the proportion of polyhedral bubbles decreases in both the steel samples. For the samples implanted at the same temperature, the average size of He bubbles in MNHS is smaller than that in T91. This might be due to the abundance of boundaries and precipitates in MNHS, which provide additional sites for the trapping of He atoms, thus reduce the susceptibility of MNHS to He embrittlement. (paper)

  6. HR-TEM and FT-Raman dataset of the caffeine interacted Phe–Phe peptide nanotube for possible sensing applications

    Directory of Open Access Journals (Sweden)

    A. Lakshmi Narayanan

    2018-02-01

    Full Text Available Sensing ability of caffeine interaction with Phe-Phe annotates (PNTs, is presented (Govindhan et al., 2017; Karthikeyan et al., 2014; Tavagnacco et al., 2013; Kennedy et al., 2011; Wang et al., 2017 [1–5] in this data set. Investigation of synthesized caffeine carrying peptide nanotubes are carried out by FT-Raman spectral analysis and high resolution transmission electron microscopy (HR-TEM. Particle size of the caffeine loaded PNTs is < 40 nm. The FT-Raman spectrum signals are enhanced in the region of 400–1700 cm−1. These data are ideal tool for the applications like biosensing and drug delivery research (DDS. Keywords: Caffeine, PNTs, Sensing, HR-TEM, FT-Raman data

  7. Preparation of herpes simplex virus-infected primary neurons for transmission electron microscopy.

    Science.gov (United States)

    Miranda-Saksena, Monica; Boadle, Ross; Cunningham, Anthony L

    2014-01-01

    Transmission electron microscopy (TEM) provides the resolution necessary to identify both viruses and subcellular components of cells infected with many types of viruses, including herpes simplex virus. Recognized as a powerful tool in both diagnostic and research-based virology laboratories, TEM has made possible the identification of new viruses and has contributed to the elucidation of virus life cycle and virus-host cell interaction. Whilst there are many sample preparation techniques for TEM, conventional processing using chemical fixation and resin embedding remains a useful technique, available in virtually all EM laboratories, for studying virus/cell ultrastructure. In this chapter, we describe the preparation of herpes simplex virus-infected primary neurons, grown on plastic cover slips, to allow sectioning of neurons and axons in their growth plane. This technique allows TEM examination of cell bodies, axons, growth cones, and varicosities, providing powerful insights into virus-cell interaction.

  8. Novel lift-off technique for Transmission Electron Microscopy imaging of block copolymer films

    International Nuclear Information System (INIS)

    Roache, Fergus J.M.; Radjainia, Mazdak; Williams, David E.; Gerrard, Juliet A.; Travas-Sejdic, Jadranka; Malmström, Jenny

    2015-01-01

    We have developed a simple technique to allow for the lift-off and subsequent transfer of poly(styrene-block-ethylene glycol) films to Transmission Electron Microscopy (TEM) grids. The block copolymer is spin coated onto carbon coated mica and annealed. After the thin film is produced it can easily be floated onto water and picked up by a TEM grid. This method offers better control over film processing than dip coating the TEM grid and is also a significant improvement over methods using etchants such as hydrofluoric acid. - Highlights: • We have developed a simple method to lift block copolymer films to TEM grids. • Polymer films prepared on carbon coated mica are easily floated on water. • The new method circumvents the use of harsh chemicals

  9. Fourier plane imaging microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Dominguez, Daniel, E-mail: daniel.dominguez@ttu.edu; Peralta, Luis Grave de [Department of Physics, Texas Tech University, Lubbock, Texas 79409 (United States); Nano Tech Center, Texas Tech University, Lubbock, Texas 79409 (United States); Alharbi, Nouf; Alhusain, Mdhaoui [Department of Physics, Texas Tech University, Lubbock, Texas 79409 (United States); Bernussi, Ayrton A. [Nano Tech Center, Texas Tech University, Lubbock, Texas 79409 (United States); Department of Electrical and Computer Engineering, Texas Tech University, Lubbock, Texas 79409 (United States)

    2014-09-14

    We show how the image of an unresolved photonic crystal can be reconstructed using a single Fourier plane (FP) image obtained with a second camera that was added to a traditional compound microscope. We discuss how Fourier plane imaging microscopy is an application of a remarkable property of the obtained FP images: they contain more information about the photonic crystals than the images recorded by the camera commonly placed at the real plane of the microscope. We argue that the experimental results support the hypothesis that surface waves, contributing to enhanced resolution abilities, were optically excited in the studied photonic crystals.

  10. Electrochemical force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kalinin, Sergei V.; Jesse, Stephen; Collins, Liam F.; Rodriguez, Brian J.

    2017-01-10

    A system and method for electrochemical force microscopy are provided. The system and method are based on a multidimensional detection scheme that is sensitive to forces experienced by a biased electrode in a solution. The multidimensional approach allows separation of fast processes, such as double layer charging, and charge relaxation, and slow processes, such as diffusion and faradaic reactions, as well as capturing the bias dependence of the response. The time-resolved and bias measurements can also allow probing both linear (small bias range) and non-linear (large bias range) electrochemical regimes and potentially the de-convolution of charge dynamics and diffusion processes from steric effects and electrochemical reactivity.

  11. MORPHOLOGICAL ASPECTS OF HUMAN LENS CAPSULES - A COMPARATIVE LM, SEM AND TEM EXAMINATION

    NARCIS (Netherlands)

    JONGEBLOED, WL; KALICHARAN, D; LOS, LI; VANDERVEEN, G; WORST, JGF

    1991-01-01

    Lens capsules of patients of advanced age, obtained after extracapsular cataract surgery, were carefully prepared for a combined LM, TEM and SEM investigation, after preliminary washing and mounting onto a holder in a buffer solution. After pre-fixation with GA, samples were postfixed for LM/TEM and

  12. HUMAN CAPSULE EPITHELIAL-CELL DEGENERATION A LM, SEM AND TEM INVESTIGATION

    NARCIS (Netherlands)

    JONGEBLOED, WL; KALICHARAN, D; WORST, JGF

    1993-01-01

    The degeneration of the capsule epithelium of cataractous lenses has been studied with LM, SEM on TEM with emphases on TEM. The observed degeneration of the epithelial cells can be described as follows: The cell nucleus becomes picnotic and desintegrates as result of change of the chromatin.

  13. Molecular identification of TEM-116 beta-lactamase gene in isolates ...

    African Journals Online (AJOL)

    Purpose: Purpose: To determine TEM-116 beta-lactamase gene prevalence in drug-resistant Pseudomonas aeruginosa isolates from Pakistan. Methods: Sequence analysis of TEM beta-lactamase isolates and their antibiotic susceptibility patterns were carried out. Quantitative bacteriostatic concentrations for commonly ...

  14. Use of the TEM Cell for Compliance Testing of Emissions and Immunity, an IEC Perspective

    DEFF Research Database (Denmark)

    Bentz, Sigurd

    1996-01-01

    The current work of the IEC on preparing a standard for the use of TEM cells for compliance testing of emissions and immunity is reviewed. The requirements of TEM cells are related to the established procedures: “open area test site” and “shielded enclosure with area of uniform field”, respective...

  15. Pilot production of track etch membranes (TEMS) using heavy ion beam scanner

    International Nuclear Information System (INIS)

    Nair, J.P.; Surendran, P.; Sparrow, Hillary; Ninawe, N.G.; Bhagwat, P.V.; Acharya, N.; Kulshreshta, V.; Rajesh Kumar; Vijay, Y.K.; Kurup, M.B.

    2005-01-01

    Various methods for making TEMs were conducted at Pelletron Accelerator Facility. The technique for production using ion beam scattering was also established. This is an effort to make TEMs on pilot basis at BARC- TIFR Pelletron Accelerator using Heavy Ion Beam Scanner till large rolling mechanism is implemented

  16. XRD and TEM analysis of microstructure in the welding zone of 9Cr ...

    Indian Academy of Sciences (India)

    Unknown

    XRD and TEM analysis of microstructure in the welding zone of. 9Cr–1Mo–V–Nb ... steel, which has highest Cr content in the heat-resisting. Cr–Mo ... This research provides essential ... film samples were observed under TEM and select elec-.

  17. ANALISIS JARINGAN UMTS PADA MENARA ROOFTOP DENGAN MENGGUNAKAN SOFTWARE TEMS INVESTIGATION DAN G-NETTRACK PRO

    OpenAIRE

    Pande Putu Wahyu Pramanda; Pande Ketut Sudiarta; Ngurah Indra ER.

    2016-01-01

    Berkembangnya dunia teknologi telekomunikasi dan informasi sejalan dengan kebutuhan akan kecepatan dan kestabilan akses internet teknologi UMTS. Metode drive test adalah metode yang biasanya digunakan untuk pengukuran kualitas sebuah site. Pihak provider umumnya menggunakan software TEMS Investigation dalam melakukan drive test. Melakukan drive test dengan TEMS Investigation sangatlah tidak praktis dan memerlukan biaya yang besar. Berkembangnya teknologi smartphone membuat drive test dapat di...

  18. Correlative scanning-transmission electron microscopy reveals that a chimeric flavivirus is released as individual particles in secretory vesicles.

    Directory of Open Access Journals (Sweden)

    Julien Burlaud-Gaillard

    Full Text Available The intracellular morphogenesis of flaviviruses has been well described, but flavivirus release from the host cell remains poorly documented. We took advantage of the optimized production of an attenuated chimeric yellow fever/dengue virus for vaccine purposes to study this phenomenon by microscopic approaches. Scanning electron microscopy (SEM showed the release of numerous viral particles at the cell surface through a short-lived process. For transmission electron microscopy (TEM studies of the intracellular ultrastructure of the small number of cells releasing viral particles at a given time, we developed a new correlative microscopy method: CSEMTEM (for correlative scanning electron microscopy - transmission electron microscopy. CSEMTEM analysis suggested that chimeric flavivirus particles were released as individual particles, in small exocytosis vesicles, via a regulated secretory pathway. Our morphological findings provide new insight into interactions between flaviviruses and cells and demonstrate that CSEMTEM is a useful new method, complementary to SEM observations of biological events by intracellular TEM investigations.

  19. Plasticity mechanisms in ultrafine grained freestanding aluminum thin films revealed by in-situ transmission electron microscopy nanomechanical testing

    International Nuclear Information System (INIS)

    Idrissi, Hosni; Kobler, Aaron; Amin-Ahmadi, Behnam; Schryvers, Dominique; Coulombier, Michael; Pardoen, Thomas; Galceran, Montserrat; Godet, Stéphane; Raskin, Jean-Pierre; Kübel, Christian

    2014-01-01

    In-situ bright field transmission electron microscopy (TEM) nanomechanical tensile testing and in-situ automated crystallographic orientation mapping in TEM were combined to unravel the elementary mechanisms controlling the plasticity of ultrafine grained Aluminum freestanding thin films. The characterizations demonstrate that deformation proceeds with a transition from grain rotation to intragranular dislocation glide and starvation plasticity mechanism at about 1% deformation. The grain rotation is not affected by the character of the grain boundaries. No grain growth or twinning is detected

  20. Plasticity mechanisms in ultrafine grained freestanding aluminum thin films revealed by in-situ transmission electron microscopy nanomechanical testing

    Energy Technology Data Exchange (ETDEWEB)

    Idrissi, Hosni, E-mail: hosni.idrissi@ua.ac.be [EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Institute of Mechanics, Materials and Civil Engineering, Université catholique de Louvain, Place Sainte Barbe 2, B-1348 Louvain-La-Neuve (Belgium); Kobler, Aaron [Institute of Nanotechnology (INT) and Karlsruhe Nano Micro Facility (KNMF), Karlsruhe Institute of Technology - KIT, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Joint Research Laboratory Nanomaterials (KIT and TUD) at Technische Universität Darmstadt (TUD), Petersenstr. 32, 64287 Darmstadt (Germany); Amin-Ahmadi, Behnam; Schryvers, Dominique [EMAT, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Coulombier, Michael; Pardoen, Thomas [Institute of Mechanics, Materials and Civil Engineering, Université catholique de Louvain, Place Sainte Barbe 2, B-1348 Louvain-La-Neuve (Belgium); Galceran, Montserrat; Godet, Stéphane [Matters and Materials Department, Université Libre de Bruxelles, 50 Av. FD Roosevelt CP194/03, 1050 Brussels (Belgium); Raskin, Jean-Pierre [Information and Communications Technologies, Electronics and Applied Mathematics (ICTEAM), Microwave Laboratory, Université catholique de Louvain, B-1348 Louvain-la-Neuve (Belgium); Kübel, Christian [Institute of Nanotechnology (INT) and Karlsruhe Nano Micro Facility (KNMF), Karlsruhe Institute of Technology - KIT, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

    2014-03-10

    In-situ bright field transmission electron microscopy (TEM) nanomechanical tensile testing and in-situ automated crystallographic orientation mapping in TEM were combined to unravel the elementary mechanisms controlling the plasticity of ultrafine grained Aluminum freestanding thin films. The characterizations demonstrate that deformation proceeds with a transition from grain rotation to intragranular dislocation glide and starvation plasticity mechanism at about 1% deformation. The grain rotation is not affected by the character of the grain boundaries. No grain growth or twinning is detected.

  1. Correlative Stochastic Optical Reconstruction Microscopy and Electron Microscopy

    Science.gov (United States)

    Kim, Doory; Deerinck, Thomas J.; Sigal, Yaron M.; Babcock, Hazen P.; Ellisman, Mark H.; Zhuang, Xiaowei

    2015-01-01

    Correlative fluorescence light microscopy and electron microscopy allows the imaging of spatial distributions of specific biomolecules in the context of cellular ultrastructure. Recent development of super-resolution fluorescence microscopy allows the location of molecules to be determined with nanometer-scale spatial resolution. However, correlative super-resolution fluorescence microscopy and electron microscopy (EM) still remains challenging because the optimal specimen preparation and imaging conditions for super-resolution fluorescence microscopy and EM are often not compatible. Here, we have developed several experiment protocols for correlative stochastic optical reconstruction microscopy (STORM) and EM methods, both for un-embedded samples by applying EM-specific sample preparations after STORM imaging and for embedded and sectioned samples by optimizing the fluorescence under EM fixation, staining and embedding conditions. We demonstrated these methods using a variety of cellular targets. PMID:25874453

  2. Localization of Minodronate in Mouse Femora Through Isotope Microscopy

    Science.gov (United States)

    Hongo, Hiromi; Sasaki, Muneteru; Kobayashi, Sachio; Hasegawa, Tomoka; Yamamoto, Tomomaya; Tsuboi, Kanako; Tsuchiya, Erika; Nagai, Tomoya; Khadiza, Naznin; Abe, Miki; Kudo, Ai; Oda, Kimimitsu; Henrique Luiz de Freitas, Paulo; Li, Minqi; Yurimoto, Hisayoshi; Amizuka, Norio

    2016-01-01

    Minodronate is highlighted for its marked and sustained effects on osteoporotic bones. To determine the duration of minodronate’s effects, we have assessed the localization of the drug in mouse bones through isotope microscopy, after labeling it with a stable nitrogen isotope ([15N]-minodronate). In addition, minodronate-treated bones were assessed by histochemistry and transmission electron microscopy (TEM). Eight-week-old male ICR mice received [15N]-minodronate (1 mg/kg) intravenously and were sacrificed after 3 hr, 24 hr, 1 week, and 1 month. Isotope microscopy showed that [15N]-minodronate was present mainly beneath osteoblasts rather than nearby osteoclasts. At 3 hr after minodronate administration, histochemistry and TEM showed osteoclasts with well-developed ruffled borders. However, osteoclasts were roughly attached to the bone surfaces and did not feature ruffled borders at 24 hr after minodronate administration. The numbers of tartrate-resistant acid phosphatase–positive osteoclasts and alkaline phosphatase–reactive osteoblastic area were not reduced suddenly, and apoptotic osteoclasts appeared in 1 week and 1 month after the injections. Von Kossa staining demonstrated that osteoclasts treated with minodronate did not incorporate mineralized bone matrix. Taken together, minodronate accumulates in bone underneath osteoblasts rather than under bone-resorbing osteoclasts; therefore, it is likely that the minodronate-coated bone matrix is resistant to osteoclastic resorption, which results in a long-lasting and bone-preserving effect. PMID:27666429

  3. Analysis of arsenic speciation in mine contaminated lacustrine sediment using selective sequential extraction, HR-ICPMS and TEM

    International Nuclear Information System (INIS)

    Haus, Kelly L.; Hooper, Robert L.; Strumness, Laura A.; Mahoney, J. Brian

    2008-01-01

    In order to determine how As speciation in lacustrine sediment changes as a function of local conditions, sediment cores were taken from three lakes with differing hydrologic regimes and subjected to extensive chemical and TEM analysis. The lakes (Killarney, Thompson and Swan Lakes) are located within the Coeur d' Alene River system (northern Idaho, USA), which has been contaminated with trace metals and As, from over 100 a of sulfide mining. Previous analyses of these lakebed sediments have shown an extensive amount of contaminant metals and As associated with sub-μm grains, making them extremely difficult to analyze using standard methods (scanning electron microscopy, X-ray diffraction). Transmission electron microscopy offers great advantages in spatial resolution and can be invaluable in determining As speciation when combined with other techniques. Data indicate that because of differences in local redox conditions, As speciation and stability is dramatically different in these lakes. Killarney and Thompson Lakes experience seasonal water-level fluctuations due to drawdown on a downstream dam, causing changes in O 2 content in sediment exposed during drawdown. Swan Lake has relatively constant water levels as its only inlet is dammed. Consequently, Killarney and Thompson Lakes show an increase in labile As-bearing phases with depth, while Swan Lake data indicate stable As hosts throughout the sediment profile. Based on these observations it can be stated that As in lakebed sediments is much less mobile, and therefore less bioavailable, when water is kept at a constant level

  4. Analysis of arsenic speciation in mine contaminated lacustrine sediment using selective sequential extraction, HR-ICPMS and TEM

    Energy Technology Data Exchange (ETDEWEB)

    Haus, Kelly L. [Department of Geology, Phillips 157, University of Wisconsin - Eau Claire, Eau Claire, WI 54702-4004 (United States)], E-mail: khaus@vt.edu; Hooper, Robert L.; Strumness, Laura A.; Mahoney, J. Brian [Department of Geology, Phillips 157, University of Wisconsin - Eau Claire, Eau Claire, WI 54702-4004 (United States)

    2008-04-15

    In order to determine how As speciation in lacustrine sediment changes as a function of local conditions, sediment cores were taken from three lakes with differing hydrologic regimes and subjected to extensive chemical and TEM analysis. The lakes (Killarney, Thompson and Swan Lakes) are located within the Coeur d' Alene River system (northern Idaho, USA), which has been contaminated with trace metals and As, from over 100 a of sulfide mining. Previous analyses of these lakebed sediments have shown an extensive amount of contaminant metals and As associated with sub-{mu}m grains, making them extremely difficult to analyze using standard methods (scanning electron microscopy, X-ray diffraction). Transmission electron microscopy offers great advantages in spatial resolution and can be invaluable in determining As speciation when combined with other techniques. Data indicate that because of differences in local redox conditions, As speciation and stability is dramatically different in these lakes. Killarney and Thompson Lakes experience seasonal water-level fluctuations due to drawdown on a downstream dam, causing changes in O{sub 2} content in sediment exposed during drawdown. Swan Lake has relatively constant water levels as its only inlet is dammed. Consequently, Killarney and Thompson Lakes show an increase in labile As-bearing phases with depth, while Swan Lake data indicate stable As hosts throughout the sediment profile. Based on these observations it can be stated that As in lakebed sediments is much less mobile, and therefore less bioavailable, when water is kept at a constant level.

  5. Report on the progress of various ongoing projects on out JEOL 3000f 300 kV FEG TEM

    International Nuclear Information System (INIS)

    Bulcock, S.R.; Zou, J.; Cai, D.; Ringer, S.P.

    2002-01-01

    Full text: The Electron Microscope Unit (EMU) at the University of Sydney has recently installed a new JEOL 3000F Field Emission Gun TEM. With a point resolution of 1.95 Angstroms, it is the ideal tool for high resolution imaging. The microscope also has an Oxford INCA EDS system and GATAN GIF attached, and with an incident probe of diameter ≥0.5nm. As such, it is an excellent tool for microanalysis and in conjunction with a VGSTEM, these facilities are ideal for a large variety of materials microscopy and microanalysis at high resolution. These facilities are also central to the outreach work of the EMU'S Key Centre and add important capability to the Nanostructural Analysis Network Organisation (NANO) the new Australian Major National Research Facility in characterisation. In this poster we will be presenting results from a number of ongoing projects which demonstrate some of the capabilities of both microscopes, including high resolution imaging, phase analysis in Al alloys, compositional gradients in novel glass optical fibres, alternative mechanisms for the formation of misfit dislocation in quantum dots and compositional analysis in quantum well structures. Copyright (2002) Australian Society for Electron Microscopy Inc

  6. Microstructural studies of 35 degrees C copper Ni-Ti orthodontic wire and TEM confirmation of low-temperature martensite transformation.

    Science.gov (United States)

    Brantley, William A; Guo, Wenhua; Clark, William A T; Iijima, Masahiro

    2008-02-01

    Previous temperature-modulated differential scanning calorimetry (TMDSC) study of nickel-titanium orthodontic wires revealed a large exothermic low-temperature peak that was attributed to transformation within martensitic NiTi. The purpose of this study was to use transmission electron microscopy (TEM) to verify this phase transformation in a clinically popular nickel-titanium wire, identify its mechanism and confirm other phase transformations found by TMDSC, and to provide detailed information about the microstructure of this wire. The 35 degrees C Copper nickel-titanium wire (Ormco) with cross-section dimensions of 0.016 in. x 0.022 in. used in the earlier TMDSC investigation was selected. Foils were prepared for TEM analyses by mechanical grinding, polishing, dimpling, ion milling and plasma cleaning. Standard bright-field and dark-field TEM images were obtained, along with convergent-beam electron diffraction patterns. A cryo-stage with the electron microscope (Phillips CM 200) permitted the specimen to be observed at -187, -45, and 50 degrees C, as well as at room temperature. Microstructures were also observed with an optical microscope and a scanning electron microscope. Room temperature microstructures had randomly oriented, elongated grains that were twinned. Electron diffraction patterns confirmed that phase transformations took place over temperature ranges previously found by TMDSC. TEM observations revealed a high dislocation density and fine-scale oxide particles, and that twinning is the mechanism for the low-temperature transformation in martensitic NiTi. TEM confirmed the low-temperature peak and other phase transformations observed by TMDSC, and revealed that twinning in martensite is the mechanism for the low-temperature peak. The high dislocation density and fine-scale oxide particles in the microstructure are the result of the wire manufacturing process.

  7. Quantifying Chemical and Electrochemical Reactions in Liquids by in situ Electron Microscopy

    DEFF Research Database (Denmark)

    Canepa, Silvia

    and developing a robust imaging analysis method for quantitatively understand chemical and electrochemical process during in situ liquid electron microscopy. By using two custom-made liquid cells (an electrochemical scanning electron microscopy (EC-SEM) platform and Liquid Flow S/TEM holder) beam...... of electrochemical deposition of copper (Cu) by electrochemical liquid scanning electron microscopy (EC-SEM) was done in order to direct observe the formation of dendritic structures. Finally the shape evolution from solid to hollow structures through galvanic replacement reactions were observed for different silver...

  8. Advanced Microscopy of Microbial Cells

    DEFF Research Database (Denmark)

    Haagensen, Janus Anders Juul; Regenberg, Birgitte; Sternberg, Claus

    2011-01-01

    Growing awareness of heterogeneity in cells of microbial populations has emphasized the importance of advanced microscopy for visualization and understanding of the molecular mechanisms underlying cell-to-cell variation. In this review, we highlight some of the recent advances in confocal...... microscopy, super-resolution optical microscopy (STED, SIM, PALM) as well as atomic force microscopy and Raman spectroscopy. Using examples of bistability in microbial populations as well as biofilm development and differentiation in bacterial and yeast consortia, we demonstrate the importance of microscopy...

  9. Investigation of the structure of nanocrystalline refractory oxides by X-ray diffraction, electron microscopy, and atomic force microscopy

    International Nuclear Information System (INIS)

    Ulyanova, T. M.; Titova, L. V.; Medichenko, S. V.; Zonov, Yu. G.; Konstantinova, T. E.; Glazunova, V. A.; Doroshkevich, A. S.; Kuznetsova, T. A.

    2006-01-01

    The structures of nanocrystalline fibrous powders of refractory oxides have been investigated by different methods: determination of coherent-scattering regions, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic-force microscopy (AFM). The sizes of nanograins of different crystalline phases of refractory metal oxides have been determined during the formation of these nanograins and the dynamics of their growth during heat treatment in the temperature range 600-1600 deg. C has been studied. The data on the structure of nanocrystalline refractory oxide powders, obtained by different methods, are in good agreement. According to the data on coherent-scattering regions, the sizes of the ZrO 2 (Y 2 O 3 ) and Al 2 O 3 grains formed are in the range 4-6 nm, and the particle sizes determined according to the TEM and AFM data are in the ranges 5-7 and 2-10 nm, respectively. SEM analysis made it possible to investigate the dynamics of nanoparticle growth at temperatures above 1000 deg. C and establish the limiting temperatures of their consolidation in fibers

  10. HR-TEM and FT-Raman dataset of the caffeine interacted Phe-Phe peptide nanotube for possible sensing applications.

    Science.gov (United States)

    Narayanan, A Lakshmi; Dhamodaran, M; Solomon, J Samu; Karthikeyan, B; Govindhan, R

    2018-02-01

    Sensing ability of caffeine interaction with Phe-Phe annotates (PNTs), is presented (Govindhan et al., 2017; Karthikeyan et al., 2014; Tavagnacco et al., 2013; Kennedy et al., 2011; Wang et al., 2017) [1-5] in this data set. Investigation of synthesized caffeine carrying peptide nanotubes are carried out by FT-Raman spectral analysis and high resolution transmission electron microscopy (HR-TEM). Particle size of the caffeine loaded PNTs is < 40 nm. The FT-Raman spectrum signals are enhanced in the region of 400-1700 cm -1 . These data are ideal tool for the applications like biosensing and drug delivery research (DDS).

  11. HR-TEM and FT-Raman dataset of the caffeine interacted Phe–Phe peptide nanotube for possible sensing applications

    OpenAIRE

    Narayanan, A. Lakshmi; Dhamodaran, M.; Solomon, J. Samu; Karthikeyan, B.; Govindhan, R.

    2017-01-01

    Sensing ability of caffeine interaction with Phe-Phe annotates (PNTs), is presented (Govindhan et al., 2017; Karthikeyan et al., 2014; Tavagnacco et al., 2013; Kennedy et al., 2011; Wang et al., 2017) [1–5] in this data set. Investigation of synthesized caffeine carrying peptide nanotubes are carried out by FT-Raman spectral analysis and high resolution transmission electron microscopy (HR-TEM). Particle size of the caffeine loaded PNTs is < 40 nm. The FT-Raman spectrum signals are enhanced i...

  12. Hyperspectral light sheet microscopy

    Science.gov (United States)

    Jahr, Wiebke; Schmid, Benjamin; Schmied, Christopher; Fahrbach, Florian O.; Huisken, Jan

    2015-09-01

    To study the development and interactions of cells and tissues, multiple fluorescent markers need to be imaged efficiently in a single living organism. Instead of acquiring individual colours sequentially with filters, we created a platform based on line-scanning light sheet microscopy to record the entire spectrum for each pixel in a three-dimensional volume. We evaluated data sets with varying spectral sampling and determined the optimal channel width to be around 5 nm. With the help of these data sets, we show that our setup outperforms filter-based approaches with regard to image quality and discrimination of fluorophores. By spectral unmixing we resolved overlapping fluorophores with up to nanometre resolution and removed autofluorescence in zebrafish and fruit fly embryos.

  13. Geoelectrical characterization by joint inversion of VES/TEM in Paraná basin, Brazil

    Science.gov (United States)

    Bortolozo, C. A.; Couto, M. A.; Almeida, E. R.; Porsani, J. L.; Santos, F. M.

    2012-12-01

    For many years electrical (DC) and transient electromagnetic (TEM) soundings have been used in a great number of environmental, hydrological and mining exploration studies. The data of both methods are interpreted usually by individual 1D models resulting in many cases in ambiguous models. This can be explained by how the two different methodologies sample the subsurface. The vertical electrical sounding (VES) is good on marking very resistive structures, while the transient electromagnetic sounding (TEM) is very sensitive to map conductive structures. Another characteristic is that VES is more sensitive to shallow structures, while TEM soundings can reach deeper structures. A Matlab program for joint inversion of VES and TEM soundings, by using CRS algorithm was developed aiming explore the best of the both methods. Initially, the algorithm was tested with synthetic data and after it was used to invert experimental data from Paraná sedimentary basin. We present the results of a re-interpretation of 46 VES/TEM soundings data set acquired in Bebedouro region in São Paulo State - Brazil. The previous interpretation was based in geoelectrical models obtained by single inversion of the VES and TEM soundings. In this work we present the results with single inversion of VES and TEM sounding inverted by the Curupira Program and a new interpretation based in the joint inversion of both methodologies. The goal is increase the accuracy in determining the underground structures. As a result a new geoelectrical model of the region is obtained.

  14. In situ TEM-tandem/implanter interface facility in Wuhan University for investigation of radiation effects

    International Nuclear Information System (INIS)

    Guo Liping; Li Ming; Liu Chuansheng; Song Bo; Ye Mingsheng; Fan Xiangjun; Fu Dejun

    2007-01-01

    Transmission electron microscope (TEM) interfaced to one or more ion implanters and/or accelerators, i.e. in situ TEM, provides effective tools to observe microstructural changes of studied samples during the ion irradiation. Evolution of both radiation damages and irradiation-induced nano-sized microstructures can be investigated with this technique, much more convenient than conventional ex situ techniques. In situ TEM technique has been widely applied in various fields, especially in the study of radiation damages of structural materials of fission and fusion nuclear reactors, and in evaluation and qualification of radioactive waste forms. Nowadays there are more than a dozen such facilities located in Japan, France, and the United States. Recently, we have constructed the first TEM-Tandem/Implanter interface facility of China in Wuhan University. A modified Hitachi H800 TEM was interfaced to a 200 kV ion implanter and a 2 x 1.7 MV tandem accelerator. Effective steps were taken to isolate the TEM from mechanical vibration from the ion beam line, and no obvious wobbling of the TEM image was observed during the ion implantation. The amorphization process of Si crystal irradiated by 115 keV N + ion beam was observed in the primary experiments, demonstrating that this interface facility is capable of in situ study of radiation effects. An online low energy gaseous ion source which may provide 1-20 keV H + and He + is under construction. (authors)

  15. Correlating TEM images of damage in irradiated materials to molecular dynamics simulations

    International Nuclear Information System (INIS)

    Schaeublin, R.; Caturla, M.-J.; Wall, M.; Felter, T.; Fluss, M.; Wirth, B.D.; Diaz de la Rubia, T.; Victoria, M.

    2002-01-01

    TEM image simulations are used to couple the results from molecular dynamics (MD) simulations to experimental TEM images. In particular we apply this methodology to the study of defects produced during irradiation. MD simulations have shown that irradiation of FCC metals results in a population of vacancies and interstitials forming clusters. The limitation of these simulations is the short time scales available, on the order of 100 s of picoseconds. Extrapolation of the results from these short times to the time scales of the laboratory has been difficult. We address this problem by two methods: we perform TEM image simulations of MD simulations of cascades with an improved technique, to relate defects produced at short time scales with those observed experimentally at much longer time scales. On the other hand we perform in situ TEM experiments of Au irradiated at liquid-nitrogen temperatures, and study the evolution of the produced damage as the temperature is increased to room temperature. We find that some of the defects observed in the MD simulations at short time scales using the TEM image simulation technique have features that resemble those observed in laboratory TEM images of irradiated samples. In situ TEM shows that stacking fault tetrahedra are present at the lowest temperatures and are stable during annealing up to room temperature, while other defect clusters migrate one dimensionally above -100 deg. C. Results are presented here

  16. Progress in the Correlative Atomic Force Microscopy and Optical Microscopy

    Directory of Open Access Journals (Sweden)

    Lulu Zhou

    2017-04-01

    Full Text Available Atomic force microscopy (AFM has evolved from the originally morphological imaging technique to a powerful and multifunctional technique for manipulating and detecting the interactions between molecules at nanometer resolution. However, AFM cannot provide the precise information of synchronized molecular groups and has many shortcomings in the aspects of determining the mechanism of the interactions and the elaborate structure due to the limitations of the technology, itself, such as non-specificity and low imaging speed. To overcome the technical limitations, it is necessary to combine AFM with other complementary techniques, such as fluorescence microscopy. The combination of several complementary techniques in one instrument has increasingly become a vital approach to investigate the details of the interactions among molecules and molecular dynamics. In this review, we reported the principles of AFM and optical microscopy, such as confocal microscopy and single-molecule localization microscopy, and focused on the development and use of correlative AFM and optical microscopy.

  17. Development of a versatile TEM specimen holder for the characterization of photocatalytic materials

    DEFF Research Database (Denmark)

    Cavalca, Filippo; Langhammer, C.; Hansen, Thomas Willum

    2011-01-01

    conventional TEM analysis on photocatalysts with several in situ TEM techniques including environmental TEM (ETEM), in situ photo activation and localized surface plasmon resonance (LSPR) spectroscopy [3-4]. These experiments are facilitated by the construction of a specimen holder capable of illuminating....../on nanomaterials and thin films. We present results from combined ETEM-LSPR studies of thermally-induced catalytic phenomena and on metal nanoparticle sintering, an important process in catalysis, which we study in situ in both real and model systems by means of indirect nanoplasmonic sensing and ETEM....

  18. TEM investigation of the microstructural evolution in nickel during MeV helium implantation

    International Nuclear Information System (INIS)

    Gadalla, A.A.; Jaeger, W.; Ehrhart, P.

    1986-01-01

    In a recent TEM investigation of high energy He-implanted copper the low average helium density could be understood by the observation of the coexistence of two types of vacancy agglomerates i.e. relaxed vacancy agglomerates in the form of stacking fault tetrahedra (SFT) and small bubbles. In order to arrive at a more systematic understanding of the evolution of the microstructure during high energy helium implantation we extended these TEM investigations to nickel. Of particular interest was also the minimum implantation dose necessary to precipitate bubbles that are large enough to be visible in the TEM. (orig./RK)

  19. Tie2-expressing monocytes (TEMs): novel targets and vehicles of anticancer therapy?

    Science.gov (United States)

    De Palma, Michele; Naldini, Luigi

    2009-08-01

    There is a growing interest in understanding the complex interactions between bone marrow-derived myeloid-lineage cells and angiogenesis in tumors. Such interest has been revived recently by the observation that tumor-infiltrating myeloid cells convey proangiogenic programs that can counteract the activity of antiangiogenic drugs in mouse tumor models. Among myeloid cells, Tie2-expressing monocytes (TEMs) appear to have nonredundant function in promoting tumor angiogenesis and growth in mouse models. The identification and functional characterization of TEMs in mice and humans may provide novel molecular targets for anticancer therapy. Moreover, TEMs may be exploited to deliver antitumor drugs specifically to the tumor microenvironment.

  20. Transmission electron microscopy of InP-based compound semiconductor materials and devices

    International Nuclear Information System (INIS)

    Chu, S.N.G.

    1990-01-01

    InP/InGaAsP-based heteroepitaxial structures constitute the major optoelectronic devices for state-of-the-art long wavelength optical fiber communication system.s Future advanced device structures will require thin heteroepitaxial quantum wells and superlattices a few tens of angstrom or less in thickness, and lateral dimensions ranging from a few tens angstrom for quantum dots and wires to a few μm in width for buried heterostructure lasers. Due to the increasing complexity of the device structure required by band-gap engineering, the performance of these devices becomes susceptible to any lattice imperfections present in the structure. Transmission electron microscopy (TEM), therefore, becomes the most important technique in characterizing the structural integrity of these materials. Cross-section transmission electron microscopy (XTEM) not only provides the necessary geometric information on the device structure; a careful study of the materials science behind the observed lattice imperfections provides directions for optimization of both the epitaxial growth parameters and device processing conditions. Furthermore, for device reliability studies, TEM is the only technique that unambiguously identifies the cause of device degradation. In this paper, the authors discuss areas of application of various TEM techniques, describe the TEM sample preparation technique, and review case studies to demonstrate the power of the TEM technique

  1. Scanning electron microscopy and micro-analyses

    International Nuclear Information System (INIS)

    Brisset, F.; Repoux, L.; Ruste, J.; Grillon, F.; Robaut, F.

    2008-01-01

    materials; 18b - metallation; 19 - biological samples - overview of preparation techniques; 20 - 3-D reconstruction of rough surfaces; 20a - 3-D imaging; 21 - SEM images: from numerical processing to quantitative analysis; 22 - STEM (scanning transmission electron microscopy); 23 - in-situ mechanical tests; 24 - SEM and X-ray microanalysis maintenance and control; 25 - quality assurance and standardization; 26 - SEM share in experimental techniques; 27 - introduction to FIB; 28 - introduction to TEM (transmission electron microscopy); 29 - X-ray microanalysis on thin samples; 30 - introduction to cathodoluminescence; 31 - introduction to Raman spectroscopy. (J.S.)

  2. Size Determination of Au Aerosol Nanoparticles by Off-Line TEM/STEM Observations

    Science.gov (United States)

    Karlsson, Lisa S.; Deppert, Knut; Malm, Jan-Olle

    2006-12-01

    Determination of particle size distributions of Au aerosol nanoparticles has been performed by a TEM/STEM investigation. The particles are generated by an evaporation/condensation method and are size-selected by differential mobility analyzers (DMA) based on their electrical mobility. Off-line TEM measurements resulted in equivalent projected area diameters assuming that the particles are spherical in shape. In this paper critical factors such as magnification calibration, sampling, image analysis, beam exposure and, particle shape are treated. The study shows that the measures of central tendency; mean, median and mode, are equal as expected from a narrow size distribution. Moreover, the correlation between TEM/STEM and DMA are good, in practice 1:1. Also, STEM has the advantage over TEM due to enhanced contrast and is proposed as an alternative route for determination of particle size distributions of nanoparticles with lower contrast.

  3. Size Determination of Au Aerosol Nanoparticles by Off-Line TEM/STEM Observations

    International Nuclear Information System (INIS)

    Karlsson, Lisa S.; Deppert, Knut; Malm, Jan-Olle

    2006-01-01

    Determination of particle size distributions of Au aerosol nanoparticles has been performed by a TEM/STEM investigation. The particles are generated by an evaporation/condensation method and are size-selected by differential mobility analyzers (DMA) based on their electrical mobility. Off-line TEM measurements resulted in equivalent projected area diameters assuming that the particles are spherical in shape. In this paper critical factors such as magnification calibration, sampling, image analysis, beam exposure and, particle shape are treated. The study shows that the measures of central tendency; mean, median and mode, are equal as expected from a narrow size distribution. Moreover, the correlation between TEM/STEM and DMA are good, in practice 1:1. Also, STEM has the advantage over TEM due to enhanced contrast and is proposed as an alternative route for determination of particle size distributions of nanoparticles with lower contrast

  4. ANALISIS JARINGAN UMTS PADA MENARA ROOFTOP DENGAN MENGGUNAKAN SOFTWARE TEMS INVESTIGATION DAN G-NETTRACK PRO

    Directory of Open Access Journals (Sweden)

    Pande Putu Wahyu Pramanda

    2016-03-01

    Full Text Available Berkembangnya dunia teknologi telekomunikasi dan informasi sejalan dengan kebutuhan akan kecepatan dan kestabilan akses internet teknologi UMTS. Metode drive test adalah metode yang biasanya digunakan untuk pengukuran kualitas sebuah site. Pihak provider umumnya menggunakan software TEMS Investigation dalam melakukan drive test. Melakukan drive test dengan TEMS Investigation sangatlah tidak praktis dan memerlukan biaya yang besar. Berkembangnya teknologi smartphone membuat drive test dapat dilakukan dengan menggunakan handphone yaitu dengan G-NetTrack Pro. Namun G-NetTrack Pro tidak memiliki kemampuan yang sama dengan TEMS Investigation. Software G-NetTrack Pro dapat digunakan sebagai bahan pembelajaran yaitu untuk pengenalan drivetest namun belum cocok digunakan secara profesional. G-NetTrack Pro dapat menampilkan data yang dibutuhkan dalam drive test namun tidak sedetail TEMS Investigation, sehingga dalam proses pembelajaran dapat digunakan untuk pengenalan karena efisien dan dapat di install pada handphone mahasiswa namun tidak dapat digunakan melakukan drive test misalnya dalam dunia kerja atau secara professional.

  5. Electron microscopy (nonbiological)

    International Nuclear Information System (INIS)

    Cowley, J.M.

    1986-01-01

    The period 1982-1985, which is covered by this review, has seen major advances in the capabilities of the commercially available instruments. The new electron microscopes operating in the range of 300-400 keV have provided important improvements in the resolution available and in the possibilities for microanalysis of very small specimen areas. Correspondingly there has been a broadening in the range of possible applications of the techniques. Electron microscopy has become a much more powerful tool for studies of semiconductors and catalysts, for example, and offers promise of a major revolution in surface science. The major industrial laboratories, in particular, are investing in million-dollar instruments and in the highly skilled scientists needed to run them because the capabilities of the new instruments are seen to have immediate practical applications to current industrial research. Unfortunately all of the new instruments and most of the skilled users come from overseas. The American instrument industry, although showing some limited signs of life, is not yet in a position to compete in this lucrative market and the training of electron optics specialists in this country is far from meeting the demand. The increased sophistication required for both the operation of the instruments and the interpretation of the observation requires that the quality as well as the quantity of trainees must be improved. 62 references

  6. Ultrafast scanning tunneling microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Botkin, D.A. [California Univ., Berkeley, CA (United States). Dept. of Physics]|[Lawrence Berkeley Lab., CA (United States)

    1995-09-01

    I have developed an ultrafast scanning tunneling microscope (USTM) based on uniting stroboscopic methods of ultrafast optics and scanned probe microscopy to obtain nanometer spatial resolution and sub-picosecond temporal resolution. USTM increases the achievable time resolution of a STM by more than 6 orders of magnitude; this should enable exploration of mesoscopic and nanometer size systems on time scales corresponding to the period or decay of fundamental excitations. USTM consists of a photoconductive switch with subpicosecond response time in series with the tip of a STM. An optical pulse from a modelocked laser activates the switch to create a gate for the tunneling current, while a second laser pulse on the sample initiates a dynamic process which affects the tunneling current. By sending a large sequence of identical pulse pairs and measuring the average tunnel current as a function of the relative time delay between the pulses in each pair, one can map the time evolution of the surface process. USTM was used to measure the broadband response of the STM`s atomic size tunnel barrier in frequencies from tens to hundreds of GHz. The USTM signal amplitude decays linearly with the tunnel junction conductance, so the spatial resolution of the time-resolved signal is comparable to that of a conventional STM. Geometrical capacitance of the junction does not appear to play an important role in the measurement, but a capacitive effect intimately related to tunneling contributes to the measured signals and may limit the ultimate resolution of the USTM.

  7. Superconductivity and electron microscopy

    International Nuclear Information System (INIS)

    Hawkes, P.W.; Valdre, U.

    1977-01-01

    In this review article, two aspects of the role of superconductivity in electron microscopy are examined: (i) the development of superconducting devices (mainly lenses) and their incorporation in electron microscopes; (ii) the development of electron microscope techniques for studying fundamental and technological problems associated with superconductivity. The first part opens with a brief account of the relevant properties of conventional lenses, after which the various types of superconducting lenses are described and their properties compared. The relative merits and inconveniences of superconducting and conventional lenses are examined, particular attention being paid to the spherical and chromatic aberration coefficients at accelerating voltages above a megavolt. This part closes with a survey of the various microscope designs that have been built or proposed, incorporating superconducting components. In the second part, some methods that have been or might be used in the study of superconductivity in the electron microscope are described. A brief account of the types of application for which they are suitable is given. (author)

  8. Transmission acoustic microscopy investigation

    Science.gov (United States)

    Maev, Roman; Kolosov, Oleg; Levin, Vadim; Lobkis, Oleg

    The nature of acoustic contrast, i.e. the connection of the amplitude and phase of the output signal of the acoustic microscope with the local values of the acoustic parameters of the sample (density, elasticity, viscosity) is a central problem of acoustic microscopy. A considerable number of studies have been devoted to the formation of the output signal of the reflection scanning acoustic microscope. For the transmission acoustic microscope (TAM) this problem has remained almost unstudied. Experimental investigation of the confocal system of the TAM was carried out on an independently manufactured laboratory mockup of the TAM with the working frequency of the 420 MHz. Acoustic lenses with the radius of curvature of about 500 microns and aperture angle of 45 deg were polished out in the end faces of two cylindrical sound conductors made from Al2O3 single crystals with an axis parallel to the axis C of the crystal (the length of the sound conductor is 20 mm; diameter, 6 mm). At the end faces of the sound conductor, opposite to the lenses, CdS transducers with a diameter of 2 mm were disposed. The electric channel of the TAM provided a possibility for registering the amplitude of the microscope output signal in the case of the dynamic range of the 50 dB.

  9. Innovative Strategies for Clinical Microscopy Instruction: Virtual Versus Light Microscopy.

    Science.gov (United States)

    McDaniel, M Jane; Russell, Gregory B; Crandall, Sonia J

    2018-06-01

    The purpose of the study was to compare virtual microscopy with light microscopy to determine differences in learning outcomes and learner attitudes in teaching clinical microscopy to physician assistant (PA) students. A prospective, randomized, crossover design study was conducted with a convenience sample of 67 first-year PA students randomized to 2 groups. One group used light microscopes to find microscopic structures, whereas the other group used instructor-directed video streaming of microscopic elements. At the midpoint of the study, the groups switched instructional strategies. Learning outcomes were assessed via posttest after each section of the study, with comparison of final practical examination results to previous cohorts. Attitudes about the 2 educational strategies were assessed through a postcourse questionnaire with a Likert scale. Analysis of the first posttest demonstrated that students in the video-streamed group had significantly better learning outcomes than those in the light microscopy group (P = .004; Cohen's d = 0.74). Analysis of the posttest after crossover showed no differences between the 2 groups (P = .48). Between the 2 posttests, students first assigned to the light microscopy group scored a 6.6 mean point increase (±10.4 SD; p = .0011), whereas students first assigned to the virtual microscopy group scored a 1.3 mean point increase (±7.1 SD; p = .29). The light microscopy group improved more than the virtual microscopy group (P = .019). Analysis of practical examination data revealed higher scores for the study group compared with 5 previous cohorts of first-year students (P virtual microscopy to traditional light microscopy. Virtual microscopy is an effective educational strategy, and students prefer this method when learning to interpret images of clinical specimens.

  10. Microstructural and micromechanical characterisation of TiAl alloys using atomic force microscopy and nanoindentation

    International Nuclear Information System (INIS)

    Gebhard, S.; Pyczak, F.; Goeken, M.

    2009-01-01

    Different microstructures were generated in the Ti-45Al-4.6Nb-0.2B-0.2C and Ti-45Al-1Cr alloys (at.%) by heat treatment. The microstructures were investigated using nanoindentation and atomic force microscopy which was compared with transmission electron microscopy. Topographic contrast is usually used for phase identification in the atomic force microscope. However, it was found that the topographic order of the phases changes with different microstructures and specimen preparations. Nanoindentation measurements provided local hardness values not obtainable by other methods and enabled clear distinction of the phases. The hardness values can give information on surrounding microstructure and solid solution hardening. The mean lamellar spacing of the colonies was measured using both atomic force microscopy and transmission electron microscopy. Atomic force microscopy was found to be suitable to determine the spacing between α 2 /γ-interfaces offering the advantages of easier sample preparation and fewer specimens compared to evaluation by TEM analysis.

  11. Laboratory design for high-performance electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    O' Keefe, Michael A.; Turner, John H.; Hetherington, Crispin J.D.; Cullis, A.G.; Carragher, Bridget; Jenkins, Ron; Milgrim, Julie; Milligan,Ronald A.; Potter, Clinton S.; Allard, Lawrence F.; Blom, Douglas A.; Degenhardt, Lynn; Sides, William H.

    2004-04-23

    Proliferation of electron 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 improve, 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.

  12. Interpretation of interfacial structures in X-ray multilayers by TEM Fresnel fringe effects

    OpenAIRE

    Nguyen, Tai D.; O'Keefe, Michael A.; Kilaas, Roar; Gronsky, Ronald; Kortright, Jeffrey B.

    1991-01-01

    Assessment of interfacial structures from high-resolution TEM images of cross-sectional specimens is difficult due to Fresnel fringe effects producing different apparent structures in the images. The effects of these fringes have been commonly over-looked in efforts of making quantitative interpretation of interfacial profiles. In this report, we present the observations of the Fresnel fringes in nanometer period Mo/Si, W/C, and WC/C multilayers in through-focus-series TEM images. Calculation...

  13. Maredata: red temática sobre datos de investigación en abierto

    OpenAIRE

    Abadal Falgueras, Ernest; Aleixandre, Rafael; Canals, Agustí; Ferrer, Antonia; Garrigós, Irene; Hernández, Tony; López-Borrull, Alexandre; Mazón, José N.; Melero Melero, Remedios; Méndez Rodríguez, Eva María; Ollé, Eva; Peset Mancebo, María Fernanda

    2017-01-01

    [ES]El objetivo central de la red temática MAREDATA es aglutinar y consolidar la colaboración entre grupos de investigación españoles centrados en el estudio de los datos científicos y también establecer relación con aquellos sectores y disciplinas interesados en esta temática.

  14. NDE Acoustic Microscopy Research Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The purpose is to develop advanced, more effective high-resolution micro-NDE materials characterization methods using scanning acoustic microscopy. The laboratory's...

  15. Magnetic Resonance Force Microscopy System

    Data.gov (United States)

    Federal Laboratory Consortium — The Magnetic Resonance Force Microscopy (MRFM) system, developed by ARL, is the world's most sensitive nuclear magnetic resonance (NMR) spectroscopic analysis tool,...

  16. Switching operation and degradation of resistive random access memory composed of tungsten oxide and copper investigated using in-situ TEM.

    Science.gov (United States)

    Arita, Masashi; Takahashi, Akihito; Ohno, Yuuki; Nakane, Akitoshi; Tsurumaki-Fukuchi, Atsushi; Takahashi, Yasuo

    2015-11-27

    In-situ transmission electron microscopy (in-situ TEM) was performed to investigate the switching operation of a resistive random access memory (ReRAM) made of copper, tungsten oxide and titanium nitride (Cu/WOx/TiN). In the first Set (Forming) operation to initialize the device, precipitation appeared inside the WOx layer. It was presumed that a Cu conducting filament was formed, lowering the resistance (on-state). The Reset operation induced a higher resistance (the off-state). No change in the microstructure was identified in the TEM images. Only when an additional Reset current was applied after switching to the off-state could erasure of the filament be seen (over-Reset). Therefore, it was concluded that structural change relating to the resistance switch was localized in a very small area around the filament. With repeated switching operations and increasing operational current, the WOx/electrode interfaces became indistinct. At the same time, the resistance of the off-state gradually decreased. This is thought to be caused by Cu condensation at the interfaces because of leakage current through the area other than through the filament. This will lead to device degradation through mechanisms such as endurance failure. This is the first accelerated aging test of ReRAM achieved using in-situ TEM.

  17. Insights from in situ and environmental TEM on the oriented attachment of α-Fe2O3 nanoparticles during α-Fe2O3 nanorod formation

    DEFF Research Database (Denmark)

    Almeida, Trevor P.; Fay, Michael W.; Hansen, Thomas Willum

    2014-01-01

    Acicular α-Fe2O3 nanorods (NRs), at an intermediate stage of development, were isolated using a snapshot valve-assisted hydrothermal synthesis (HS) technique, for the purpose of complementary in situ transmission electron microscopy (iTEM) and environmental TEM (ETEM) investigations of the effect......’ with the developing NR to adopt a perfect single crystal. Conversely, the heating of partially developed α-Fe2O3 NRs up to 250 °C, under vacuum, during iTEM, demonstrated the progressive coalescence of loosely packed α-Fe2O3 NPs and the coarsening of α-Fe2O3 NRs, without any direct evidence for an intermediate OA...... stage. Direct evidence was obtained for the action of an OA mechanism prior to the consumption of α-Fe2O3 NPs at the tips of developing α-Fe2O3 NRs during ETEM investigation, under an He pressure of 5 mbar at 500 °C. However, α-Fe2O3 NPs more strongly attached to the side-walls of developing α-Fe2O3 NRs...

  18. TEM in situ cube-corner indentation analysis using ViBe motion detection algorithm

    Science.gov (United States)

    Yano, K. H.; Thomas, S.; Swenson, M. J.; Lu, Y.; Wharry, J. P.

    2018-04-01

    Transmission electron microscopic (TEM) in situ mechanical testing is a promising method for understanding plasticity in shallow ion irradiated layers and other volume-limited materials. One of the simplest TEM in situ experiments is cube-corner indentation of a lamella, but the subsequent analysis and interpretation of the experiment is challenging, especially in engineering materials with complex microstructures. In this work, we: (a) develop MicroViBE, a motion detection and background subtraction-based post-processing approach, and (b) demonstrate the ability of MicroViBe, in combination with post-mortem TEM imaging, to carry out an unbiased qualitative interpretation of TEM indentation videos. We focus this work around a Fe-9%Cr oxide dispersion strengthened (ODS) alloy, irradiated with Fe2+ ions to 3 dpa at 500 °C. MicroViBe identifies changes in Laue contrast that are induced by the indentation; these changes accumulate throughout the mechanical loading to generate a "heatmap" of features in the original TEM video that change the most during the loading. Dislocation loops with b = ½ identified by post-mortem scanning TEM (STEM) imaging correspond to hotspots on the heatmap, whereas positions of dislocation loops with b = do not correspond to hotspots. Further, MicroViBe enables consistent, objective quantitative approximation of the b = ½ dislocation loop number density.

  19. VES/TEM 1D joint inversion by using Controlled Random Search (CRS) algorithm

    Science.gov (United States)

    Bortolozo, Cassiano Antonio; Porsani, Jorge Luís; Santos, Fernando Acácio Monteiro dos; Almeida, Emerson Rodrigo

    2015-01-01

    Electrical (DC) and Transient Electromagnetic (TEM) soundings are used in a great number of environmental, hydrological, and mining exploration studies. Usually, data interpretation is accomplished by individual 1D models resulting often in ambiguous models. This fact can be explained by the way as the two different methodologies sample the medium beneath surface. Vertical Electrical Sounding (VES) is good in marking resistive structures, while Transient Electromagnetic sounding (TEM) is very sensitive to conductive structures. Another difference is VES is better to detect shallow structures, while TEM soundings can reach deeper layers. A Matlab program for 1D joint inversion of VES and TEM soundings was developed aiming at exploring the best of both methods. The program uses CRS - Controlled Random Search - algorithm for both single and 1D joint inversions. Usually inversion programs use Marquadt type algorithms but for electrical and electromagnetic methods, these algorithms may find a local minimum or not converge. Initially, the algorithm was tested with synthetic data, and then it was used to invert experimental data from two places in Paraná sedimentary basin (Bebedouro and Pirassununga cities), both located in São Paulo State, Brazil. Geoelectric model obtained from VES and TEM data 1D joint inversion is similar to the real geological condition, and ambiguities were minimized. Results with synthetic and real data show that 1D VES/TEM joint inversion better recovers simulated models and shows a great potential in geological studies, especially in hydrogeological studies.

  20. Comparison between measured and predicted turbulence frequency spectra in ITG and TEM regimes

    Science.gov (United States)

    Citrin, J.; Arnichand, H.; Bernardo, J.; Bourdelle, C.; Garbet, X.; Jenko, F.; Hacquin, S.; Pueschel, M. J.; Sabot, R.

    2017-06-01

    The observation of distinct peaks in tokamak core reflectometry measurements—named quasi-coherent-modes (QCMs)—are identified as a signature of trapped-electron-mode (TEM) turbulence (Arnichand et al 2016 Plasma Phys. Control. Fusion 58 014037). This phenomenon is investigated with detailed linear and nonlinear gyrokinetic simulations using the Gene code. A Tore-Supra density scan is studied, which traverses through a linear (LOC) to saturated (SOC) ohmic confinement transition. The LOC and SOC phases are both simulated separately. In the LOC phase, where QCMs are observed, TEMs are robustly predicted unstable in linear studies. In the later SOC phase, where QCMs are no longer observed, ion-temperature-gradient (ITG) modes are identified. In nonlinear simulations, in the ITG (SOC) phase, a broadband spectrum is seen. In the TEM (LOC) phase, a clear emergence of a peak at the TEM frequencies is seen. This is due to reduced nonlinear frequency broadening of the underlying linear modes in the TEM regime compared with the ITG regime. A synthetic diagnostic of the nonlinearly simulated frequency spectra reproduces the features observed in the reflectometry measurements. These results support the identification of core QCMs as an experimental marker for TEM turbulence.

  1. Benchmarking of a novel contactless characterisation method for micro thermoelectric modules (μTEMs)

    International Nuclear Information System (INIS)

    Hickey, S; Punch, J; Jeffers, N

    2014-01-01

    Significant challenges exist in the thermal control of Photonics Integrated Circuits (PICs) for use in optical communications. Increasing component density coupled with greater functionality is leading to higher device-level heat fluxes, stretching the capabilities of conventional cooling methods using thermoelectric modules (TEMs). A tailored thermal control solution incorporating micro thermoelectric modules (μTEMs) to individually address hotspots within PICs could provide an energy efficient alternative to existing control methods. Performance characterisation is required to establish the suitability of commercially-available μTEMs for the operating conditions in current and next generation PICs. The objective of this paper is to outline a novel method for the characterisation of thermoelectric modules (TEMs), which utilises infra-red (IR) heat transfer and temperature measurement to obviate the need for mechanical stress on the upper surface of low compression tolerance (∼0.5N) μTEMs. The method is benchmarked using a commercially-available macro scale TEM, comparing experimental data to the manufacturer's performance data sheet.

  2. Establishment of in situ TEM-implanter/accelerator interface facility at Wuhan University

    International Nuclear Information System (INIS)

    Guo, L.P.; Liu, C.S.; Li, M.; Song, B.; Ye, M.S.; Fu, D.J.; Fan, X.J.

    2008-01-01

    In order to perform in situ investigations on the evolution of microstructures during ion irradiation for the evaluation of irradiation-resistance performance of advanced materials, we have established a transmission electron microscope (TEM)-implanter/accelerator interface facility at Wuhan University, the first of its kind in China. A Hitachi H800 TEM was linked to a 200 kV ion implanter and a 2x1.7 MV tandem accelerator through the interface system designed on the basis of ion beam transportation calculations. Effective steps were taken to isolate the TEM from mechanical vibration transmitted from the ion beam lines, and no significant degradation of microscope resolution was observed when the TEM operated under high zoom modes during the ion implantation. In the test experiments, ion beams of N + , He + , Ar + , and H + were successfully transported from the implanter into the TEM chamber through the interface system, and the ion currents measured at the entrance of the TEM column were between 20 and 80 nA. The amorphisation process of Si crystal irradiated by N + ion beams was successfully observed in the preliminary experiments, demonstrating that this interface facility is capable of in situ study of ion irradiated samples

  3. ANALISIS PARAMETER JARINGAN HSDPA KONDISI INDOOR DENGAN TEMS INVESTIGATION DAN G-NETTRACK PRO

    Directory of Open Access Journals (Sweden)

    Dewa Made Mahendra Yudha

    2016-03-01

    Full Text Available Penggunaan teknologi dalam sistem komunikasi bergerak sudah berkembang cukup pesat. Salah satu contohnya ada teknologi HSDPA. Pihak provider biasanya melakukan metode walk test untuk mengecek kekuatan sinyal dengan menggunakan software TEMS Investigtions. Dengan kemajuannya Teknologi walk test dapat diterapkan dengan lebih mudah yaitu menggunakan perangkat android yang sudah terinstal aplikasi G-Net track Pro. Pada penelitian ini, akan menggunakan tahapan sesuai alur yang ada pada metode penelitian yaitu dimulai dengan melakukan pengukuran berdasarkan jarak dengan membandingkan software TEMS Investigations dan G-NET TRACK PRO dengan parameter RSCP dan Ec/No. Setelah dilakukan pengukuran kemudian akan dilanjutkan dengan menganalisa antara hubungan parameter RSCP dan Ec/No menggunakan TEMS Investigations dan G-Net Pro. kemudian dilanjutkan menggunakan perhitungan teoritis parameter RSCP. Dari hasil pengukuran diproleh pada lantai I antena 1-1 pada titik jarak 5 meter parameter RSCP dengan TEMS Investigation memiliki nilai -75 dBm sedangkan dari G-Net Track Pro memiliki nilai -83 dBm. Pada parameter Ec/No dengan TEMS Investigation memiliki nilai -6 dB dan G_Net Track memiliki nilai -5 dB. Dapat disimpulkan bahwa aplikasi G-NetTrack Pro mampu menampilkan parameter yang dibutuhkan akan tetapi tidak sedetail TEMS investigation sehingga untuk proses pembelajaran dan pengenalan walk test aplikasi G-Net track Pro dapat digunakan.

  4. Track Etch Membranes (TEMS) for separation sciences from BARC-TIFR Pelletron accelerator

    International Nuclear Information System (INIS)

    Nair, J.P.; Surendran, P.; Sparrow, Hillary; Gupta, A.K.; Kailas, S.; Bhagwat, P.V.

    2014-01-01

    TEMs are very much in need for the separation of desirable/undesirable metals from industrial effluents and radioactive wastes as well as in the field of biology and gas separation. It is necessary to optimize pore size and pore density for a specific application. TEMs available in market are imported and are used for laboratory scale activity. To carry the success of these activities on industrial scale large scale production of TEMs is needed. The availability of heavy ion accelerator made possible the production of TEMs in wide range of sizes. Many countries have set up facilities for continuous production of TEMs. BARC-TIFR Pelletron Accelerator at Mumbai delivers MeV energies of heavy ions for research in basic as well as applied sciences. Heavy ions of various species and energies from BARC-TIFR Pelletron Accelerator were used to make TEMs using polyethylene terephthalate (PET/Mylar) films of 25 micron thickness. The films used were procured from reputed manufactures in India

  5. Benchmarking of a novel contactless characterisation method for micro thermoelectric modules (μTEMs)

    Science.gov (United States)

    Hickey, S.; Punch, J.; Jeffers, N.

    2014-07-01

    Significant challenges exist in the thermal control of Photonics Integrated Circuits (PICs) for use in optical communications. Increasing component density coupled with greater functionality is leading to higher device-level heat fluxes, stretching the capabilities of conventional cooling methods using thermoelectric modules (TEMs). A tailored thermal control solution incorporating micro thermoelectric modules (μTEMs) to individually address hotspots within PICs could provide an energy efficient alternative to existing control methods. Performance characterisation is required to establish the suitability of commercially-available μTEMs for the operating conditions in current and next generation PICs. The objective of this paper is to outline a novel method for the characterisation of thermoelectric modules (TEMs), which utilises infra-red (IR) heat transfer and temperature measurement to obviate the need for mechanical stress on the upper surface of low compression tolerance (~0.5N) μTEMs. The method is benchmarked using a commercially-available macro scale TEM, comparing experimental data to the manufacturer's performance data sheet.

  6. Delayed formation of chromosome aberrations in mouse pachytebne spermatocytes treated with triethylenemelamine (TEM)

    International Nuclear Information System (INIS)

    Generoso, W.M.; Krishna, M.; Sotomayor, R.E.; Cacheiro, N.L.A.

    1977-01-01

    Induction of chromosome aberrations in pachytene spermatocytes of mice by 2 mg/kg TEM was compared with induction by 400 R x rays. These doses induced comparably high dominant lethal effects in pachytene spermatocytes of mice. Cytological analysis at diakinesis-metaphase I stage showed that whereas 76.4% of the cells treated with x rays at pachytene stage had aberrations, the frequencies observed in two TEM experiments were only 0.8 and 2.2%. On the other hand, 5% of the progeny from TEM-treated pachytene spermatocytes were found to be translocation heterozygotes. This is the first report on the recovery of heritable translocations from treated spermatocytes of mice. The aberration frequencies observed for TEM in diakinesis-metaphase I were much too low to account for all the lethal mutations and heritable translocations. Thus, the formation of the bulk of aberrations induced by TEM in pachytene spermatocytes was delayed--a marked contrast to the more immediate formation of x-ray-induced aberrations. It is postulated that the formation of the bulk of TEM-induced aberrations in pachytene spermatocytes and in certain postmeiotic stages occurs sometime during spermiogenesis, and not through the operation of postfertilization pronuclear DNA synthesis

  7. Depth-resolution imaging of crystalline nanoclusters attached on and embedded in amorphous films using aberration-corrected TEM

    Energy Technology Data Exchange (ETDEWEB)

    Yamasaki, Jun, E-mail: yamasaki@uhvem.osaka-u.ac.jp [Research Center for Ultra-High Voltage Electron Microscopy, Osaka University, 7-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); EcoTopia Science Institute, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Mori, Masayuki [Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Hirata, Akihiko [Advanced Institute for Materials Research, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577 (Japan); Hirotsu, Yoshihiko [Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047 (Japan); Tanaka, Nobuo [EcoTopia Science Institute, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

    2015-04-15

    For observations of crystalline nanoclusters, the features and capabilities of depth-resolution imaging by aberration-corrected transmission electron microscopy (TEM) were investigated using image simulations and experiments for two types of samples. The first sample was gold clusters attached on an amorphous carbon film. The experimental through-focal series indicated that the focal plane for the cluster was shifted 3 nm from that for the supporting film. This difference is due to the depth-resolution imaging of the cluster and film, the mid-planes of which are separated by 3 nm along the depth direction (the electron incident direction). On the basis of this information, the three-dimensional configuration of the sample, such as the film thickness of 2 nm, was successfully illustrated. The second sample was a Zr{sub 66.7}Ni{sub 33.3} metallic glass including a medium-range-order (MRO) structure, which was approximately considered to be a crystalline cluster with a diameter of 1.6 nm. In the experimental through-focal series, the lattice fringe of the MRO cluster was visible at limited focal conditions. Image simulations reproduced well the focal conditions and also indicated a structural condition for the visualization that the embedded cluster must be apart from the mid-plane of the matrix film. Similar to the case of the first sample, this result can be explained by the idea that the “effective focal planes” for the film and cluster are at different heights. This type of depth-resolution phase contrast imaging is possible only in aberration-corrected TEM and when the sample has a simple structure and is sufficiently thin for the kinematical scattering approximation. - Highlights: • Depth-resolution imaging by aberration-corrected TEM was demonstrated. • Thickness of a carbon film supporting gold nano-crystals was successfully estimated. • A crystalline nanocluster embedded in an amorphous matrix was successfully observed. • It was clarified that

  8. Post-ion beam induced degradation of copper layers in transmission electron microscopy specimens

    Science.gov (United States)

    Seidel, F.; Richard, O.; Bender, H.; Vandervorst, W.

    2015-11-01

    Copper containing transmission electron microscopy (TEM) specimens frequently show corrosion after focused ion beam (FIB) preparation. This paper reveals that the corrosion product is a Cu-S phase growing over the specimen surface. The layer is identified by energy-dispersive x-ray spectroscopy, and lattice spacing indexing of power spectra patterns. The corrosion process is further studied by TEM on cone-shaped specimens, which are intentionally stored after FIB preparation with S flakes for short time. Furthermore, a protective method against corrosion is developed by varying the time in the FIB vacuum and the duration of a subsequent plasma cleaning.

  9. Transmission Electron Microscopy as Key Technique for the Characterization of Telocytes.

    Science.gov (United States)

    Cantarero, Irene; Luesma, Maria Jose; Alvarez-Dotu, Jose Miguel; Muñoz, Eduardo; Junquera, Concepcion

    2016-01-01

    It was 50 years ago when the details of cellular structure were first observed with an electron microscope (EM). Today, transmission electron microscopy (TEM) still provides the highest resolution detail of cellular ultrastructure. The existence of telocytes (TCs) has been described by Hinescu and Popescu in 2005 and up to now, many studies have been done in different tissues. EM has been fundamental in identification and recognition of TC and relationship between TC and stem cells (SCs) in recent years. We present a review on the importance of TEM to provide major advances in the knowledge of the biology of these cells.

  10. (CryoTransmission Electron Microscopy of Phospholipid Model Membranes Interacting with Amphiphilic and Polyphilic Molecules

    Directory of Open Access Journals (Sweden)

    Annette Meister

    2017-10-01

    Full Text Available Lipid membranes can incorporate amphiphilic or polyphilic molecules leading to specific functionalities and to adaptable properties of the lipid bilayer host. The insertion of guest molecules into membranes frequently induces changes in the shape of the lipid matrix that can be visualized by transmission electron microscopy (TEM techniques. Here, we review the use of stained and vitrified specimens in (cryoTEM to characterize the morphology of amphiphilic and polyphilic molecules upon insertion into phospholipid model membranes. Special emphasis is placed on the impact of novel synthetic amphiphilic and polyphilic bolalipids and polymers on membrane integrity and shape stability.

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

    Science.gov (United States)

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

    2014-11-01

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

  12. Contributions of electron microscopy to the understanding of reactions on compound semiconductor surfaces

    International Nuclear Information System (INIS)

    Sands, T.

    1986-01-01

    Reacted films on compound semiconductor substrates present challenging materials characterization problems which often require the application of transmission electron microscopy (TEM) techniques. In this paper, both the problem - solving potential of the TEM techniques and the limits imposed by preparation of thin film/compound semiconductor TEM specimens are discussed. Studies of the Ni/GaAs, CuCl/aq)/CdS and Pd/GaAs reactions exemplify the role of TEM in identifying and determining the spatial distribution of interface - stabilized polymorphs and new ternary phases (e.g. tetragonal Cu/sub 2/S, Ni/sub 3/GaAs and Pd/sub x/GaAs). These examples also serve to clarify the relationship between TEM and complementary analysis techniques such as Rutherford backscattering spectrometry, Auger electron spectroscopy and glancing-angle x-ray diffraction. In particular, it is argued that a combination of (1) high-spatial-resolution information obtained by TEM and (2) an indication of the ''average'' behavior provided by data from a complementary characterization technique provide the minimum quality and quantity of data necessary to understand most reactions on compound semiconductor substrates

  13. TEM examination of the effect of post-irradiation annealing on 7.7 dpa AISI 304 stainless steel

    International Nuclear Information System (INIS)

    Karlsen, W.; Ivanchenko, M.; Pakarinen, J.; Karlsen, T.

    2015-01-01

    Stainless steels exposed to neutron irradiation during service in light water reactors (LWR) can become susceptible to intergranular cracking, referred to as irradiation assisted stress corrosion cracking (IASCC). Analytical transmission electron microscopy (ATEM) was used to examine the effect of post-irradiation annealing (PIA) on radiation-induced segregation (RIS) at the grain boundaries of 7.7 dpa AISI 304 stainless steel. The grain boundary profiles and the irradiation damage were analysed in the as-irradiated state and after PIA of 6 hours at 500 C. degrees and after 25 hours at 500 C. degrees and 550 C. degrees by using transmission electron microscopy (TEM). As a main conclusion from the TEM examinations, the effects of PIA were found to be relatively small after only 6 hours, while after 25 hours of PIA at both 500 and 550 C. degrees, RIS was almost recovered and only marginal deviation in chemical composition could be found near the GB. The as-irradiated state showed extreme RIS values of Si 4.9 wt%, Cr 14.7 wt%, Ni 23.4 wt%, and P 1.4 wt%., while upon PIA for 6 hours the extreme values for RIS were Si 3.9 wt%, Cr 16.0 wt%, Ni 21 wt%, and P 0.9 wt%. After 6 hours annealing at 500 C. dislocation loops start to grow, while dislocation density remains of the same order of magnitude. After annealing for 25 hours at 500 C. degrees the average size of dislocation loops remains nearly the same, while dislocation density was reduced almost by one fold. In the areas where dislocation density was found to be the lowest some features, which can most likely be attributed to stacking fault tetrahedral (SFT) were found. Annealing at even higher temperature (550 C.) affected the average size of the dislocation loops, making them almost twice as large as well as resulting in a very broad distribution of dislocation sizes. Density of dislocations is also reduced by one fold in comparison to the as irradiated condition and leads to formation of SFTs, which could be

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

    International Nuclear Information System (INIS)

    Palmquist, Anders; Emanuelsson, Lena; Sjövall, Peter

    2012-01-01

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

  15. TEM characterization of plate-shaped L12-(Al,Ag)3Ti precipitates in a Ag-modified TiAl based intermetallics

    International Nuclear Information System (INIS)

    Yuan, Y.; Liu, H.W.; Zhao, X.N.; Meng, X.K.; Liu, Z.G.

    2006-01-01

    L1 2 -(Al,Ag) 3 Ti phase in a L1 0 -TiAl(Ag) intermetallic compound with a nominal composition of Ti-54 at.% Al-4 at.% Ag has been studied by transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM) and energy dispersive X-ray (EDX). TEM observations revealed that the alloy aged at 1273 K consists of L1 0 phase and L1 2 phase. The compositions of L1 2 phase and the matrix have been determined. The habit plane of L1 2 phase was analyzed by trace line method. It was revealed that the habit plane changed to one of {1 1 2) planes compared with our previous result. The semi-coherent interface was formed between L1 0 phase and L1 2 phase. HRTEM characterized the interface structure directly. The dislocation loops and ledges at the interphase boundary were observed. The results were discussed in terms of the competition between elastic strain and interfacial energy, ledge mechanism of phase transformation caused by long-range diffusion of the atoms

  16. Field emission scanning electron microscopy and transmission electron microscopy studies of the chorion, plasma membrane and syncytial layers of the gastrula-stage embryo of the zebrafish Brachydanio rerio : a consideration of the structural and functional relationships with respect to cryoprotectant penetration

    NARCIS (Netherlands)

    Rawson, DM; Zhang, T; Kalicharan, D; Jongebloed, WL

    The structure of the chorion and plasma membranes of gastrula-stage zebrafish Brachydanio rerio embryos were studied using field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). These studies confirm the outer chorion membrane complex to be 1.5-2.5 mu m in

  17. Extensive FE-SEM/EDS, HR-TEM/EDS and ToF-SIMS studies of micron- to nano-particles in anthracite fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Ribeiro, Joana [Centro de Geologia, Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal); DaBoit, Kátia [Institute of Environmental Research and Human Development, IPADHC, Capivari de Baixo, Santa Catarina (Brazil); Flores, Deolinda [Centro de Geologia, Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal); Departamento de Geociências, Ambiente e Ordenamento do Território, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 687, 4169-007 Porto (Portugal); Kronbauer, Marcio A. [Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Victor Barreto, 2288 Centro 92010-000, Canoas, RS (Brazil); Silva, Luis F.O., E-mail: felipeqma@hotmail.com [Laboratory of Environmental Researches and Nanotechnology Development, Centro Universitário La Salle, Victor Barreto, 2288 Centro 92010-000, Canoas, RS (Brazil); Environmental Science and Nanotechnology Department, Catarinense Institute of Environmental Research and Human Development, IPADHC, Capivari de Baixo, Santa Catarina (Brazil)

    2013-05-01

    The generation of anthropogenic carbonaceous matter and mixed crystalline/amorphous mineral ultrafine/nano-particles in the 1 to 100 nm size range by worldwide coal power plants represents serious environmental problems due to their potential hazards. Coal fly ash (CFA) that resulted from anthracite combustion in a Portuguese thermal power plant was studied in this work. The physico-chemical characterization of ultrafine/nano-particles present in the CFA samples and their interaction with environment are the aim of this study. The methodologies applied for this work were field emission scanning electron microscopy (FE-SEM) with energy dispersive X-ray spectroscopy (EDS), high-resolution transmission electron microscopy with energy dispersive X-ray spectroscopy (HR-TEM/EDS) and time of flight secondary ion mass spectrometry (ToF-SIMS). Some hazardous volatile elements, C, N, S and Hg contents were also determined in the studied samples. Generally, the CFA samples comprise carbonaceous, glassy and metallic solid spheres with some containing mixed amorphous/crystalline phases. The EDS analysis coupled with the FE-SEM and HR-TEM observations of the fly ash particles with 100 to 0.1 nm demonstrates that these materials contain a small but significant proportion of encapsulated HVEs. In addition, the presence of abundant multi-walled carbon nanotubes (MWCNTs) and amorphous carbon particles, both containing hazardous volatile elements (HVEs), was also evidenced by the FE-SEM/EDS and HR-TEM/EDS analysis. A wide range of organic and inorganic compounds was determined by chemical maps obtained in ToF-SIMS analysis. - Highlights: ► We examine changes in the level of ultrafine and nanoparticles of coal mining. ► Increasing geochemical information will increase human health information in this area. ► Electron bean and Tof-SIMS increase area information.

  18. Mechanisms of decoherence in electron microscopy

    International Nuclear Information System (INIS)

    Howie, A.

    2011-01-01

    The understanding and where possible the minimisation of decoherence mechanisms in electron microscopy were first studied in plasmon loss, diffraction contrast images but are of even more acute relevance in high resolution TEM phase contrast imaging and electron holography. With the development of phase retrieval techniques they merit further attention particularly when their effect cannot be eliminated by currently available energy filters. The roles of electronic excitation, thermal diffuse scattering, transition radiation and bremsstrahlung are examined here not only in the specimen but also in the electron optical column. Terahertz-range aloof beam electronic excitation appears to account satisfactorily for recent observations of decoherence in electron holography. An apparent low frequency divergence can emerge for the calculated classical bremsstrahlung event probability but can be ignored for photon wavelengths exceeding the required coherence distance or path lengths in the equipment. Most bremsstrahlung event probabilities are negligibly important except possibly in large-angle bending magnets or mandolin systems. A more reliable procedure for subtracting thermal diffuse scattering from diffraction pattern intensities is proposed.

  19. Mechanisms of decoherence in electron microscopy.

    Science.gov (United States)

    Howie, A

    2011-06-01

    The understanding and where possible the minimisation of decoherence mechanisms in electron microscopy were first studied in plasmon loss, diffraction contrast images but are of even more acute relevance in high resolution TEM phase contrast imaging and electron holography. With the development of phase retrieval techniques they merit further attention particularly when their effect cannot be eliminated by currently available energy filters. The roles of electronic excitation, thermal diffuse scattering, transition radiation and bremsstrahlung are examined here not only in the specimen but also in the electron optical column. Terahertz-range aloof beam electronic excitation appears to account satisfactorily for recent observations of decoherence in electron holography. An apparent low frequency divergence can emerge for the calculated classical bremsstrahlung event probability but can be ignored for photon wavelengths exceeding the required coherence distance or path lengths in the equipment. Most bremsstrahlung event probabilities are negligibly important except possibly in large-angle bending magnets or mandolin systems. A more reliable procedure for subtracting thermal diffuse scattering from diffraction pattern intensities is proposed. Copyright © 2010 Elsevier B.V. All rights reserved.

  20. Mechanisms of decoherence in electron microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Howie, A., E-mail: ah30@cam.ac.uk [Cavendish Laboratory, University of Cambridge, J.J. Thomson Avenue, Cambridge CB3 0HE (United Kingdom)

    2011-06-15

    The understanding and where possible the minimisation of decoherence mechanisms in electron microscopy were first studied in plasmon loss, diffraction contrast images but are of even more acute relevance in high resolution TEM phase contrast imaging and electron holography. With the development of phase retrieval techniques they merit further attention particularly when their effect cannot be eliminated by currently available energy filters. The roles of electronic excitation, thermal diffuse scattering, transition radiation and bremsstrahlung are examined here not only in the specimen but also in the electron optical column. Terahertz-range aloof beam electronic excitation appears to account satisfactorily for recent observations of decoherence in electron holography. An apparent low frequency divergence can emerge for the calculated classical bremsstrahlung event probability but can be ignored for photon wavelengths exceeding the required coherence distance or path lengths in the equipment. Most bremsstrahlung event probabilities are negligibly important except possibly in large-angle bending magnets or mandolin systems. A more reliable procedure for subtracting thermal diffuse scattering from diffraction pattern intensities is proposed.

  1. Electronic Blending in Virtual Microscopy

    Science.gov (United States)

    Maybury, Terrence S.; Farah, Camile S.

    2010-01-01

    Virtual microscopy (VM) is a relatively new technology that transforms the computer into a microscope. In essence, VM allows for the scanning and transfer of glass slides from light microscopy technology to the digital environment of the computer. This transition is also a function of the change from print knowledge to electronic knowledge, or as…

  2. Generation of a microelectron beam by an intense short pulse laser in the TEM(1, 0) + TEM(0, 1) mode in vacuum

    International Nuclear Information System (INIS)

    Miyazaki, Shuji; Kawata, Shigeo; Kong, Qing; Miyauchi, Koichi; Sakai, Kei; Hasumi, Shotaro; Sonobe, Ryo; Kikuchi, Takashi

    2005-01-01

    The generation of a high energy microelectron bunch in vacuum by an intense short pulse laser in the TEM(1, 0) + TEM(0, 1) mode is investigated in this paper numerically and analytically. A focused short pulse laser in the TEM(1, 0) + TEM(0, 1) mode has a confinement effect on electrons in the transverse direction due to the transverse ponderomotive force, and at the same time the electrons are accelerated and compressed longitudinally by a longitudinal electric field. In our three-dimensional particle simulations, the maximum kinetic energy of electrons reaches 455 MeV, the maximum density is 3.87 x 10 10 cm -3 , and the normalized transverse and longitudinal rms emittances of accelerated electrons are of the order of 10 -6 m rad at the following parameter values: a 0 = eE 0 /(m e ω c) = 10 (where a 0 is the dimensionless parameter of the laser amplitude, e and m e are the electron charge and rest mass, respectively, E 0 is the laser amplitude, ω the angular frequency of the laser and c the speed of light in vacuum), a laser wavelength λ = 0.8 μm, laser spot size 20λ, laser pulse length 5λ and initial electron velocity 0.99c. Moreover, the transverse and longitudinal sizes of the compressed electron bunch are about 600λ and 10λ, respectively. In this paper, we also present a scaling law of the maximum electron energy. The estimated results of the maximum electron energy coincide well with the simulation results

  3. High-temperature in-situ TEM straining of the interaction with dislocations and particles for Cu-added ferritic stainless steel.

    Science.gov (United States)

    Kobayashi, Shuhei; Kaneko, Kenji; Yamada, Kazuhiro; Kikuchi, Masao; Kanno, Norihiro; Hamada, Junichi

    2014-11-01

    IntroductionCu is always present in the matrix when ferritic steels were prepared from ferrous scrap. When the ferritic steels are aged thermally, Cu precipitates start appear and disperse finely and homogeneously [1], which may make the steels strengthened by precipitation hardening. In this study, the interaction between Cu precipitates and dislocations was exmined via high-temperature in-situ TEM straining. ExperimentalCu-added ferritic stainless steel (Fe-18.4%Cr-1.5%Cu) was used in the present study. Specimen was aged at1073 K for 360 ks. Samples for TEM observation were prepared by focused ion beam (FIB; Quanta 3D 200i) method. Microstructure of specimen was analyzed by JEM-3200FSK and high-temperature in-situ TEM straining was conducted using JEM-1300NEF. Results and discussionInteraction between Cu precipitates and dislocation is seen from consecutive TEM images acquired by in-situ TEM straining at 1073 K, as shown in Fig.1. The size of Cu precipitates was about 70 nm and several dislocations were present within the field of view. In particular, progressing dislocations contacted with the Cu precipitate at right angle, as indicated by arrows in Fig.1 (b) to (d). This result implies that there is an attractive interaction between dislocations and the Cu precipitate. This is attributed to the fact that Stress field of dislocations was easily relaxed in interface between the Cu precipitate and matrix because of lattice and interface diffusion as well as slip in the interface [2,3]. Furthermore, dislocations pass through the particle after contacting it, so that the interaction with dislocations and particles should be explained by Srolovitz mechanism [4].jmicro;63/suppl_1/i28/DFU083F1F1DFU083F1Fig. 1.TEM images foucused on interaction with dislocations and partticles. © The Author 2014. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  4. In-situ TEM on (de)hydrogenation of Pd at 0.5–4.5 bar hydrogen pressure and 20–400°C

    International Nuclear Information System (INIS)

    Yokosawa, Tadahiro; Alan, Tuncay; Pandraud, Gregory; Dam, Bernard; Zandbergen, Henny

    2012-01-01

    We have developed a nanoreactor, sample holder and gas system for in-situ transmission electron microscopy (TEM) of hydrogen storage materials up to at least 4.5 bar. The MEMS-based nanoreactor has a microheater, two electron-transparent windows and a gas inlet and outlet. The holder contains various O-rings to have leak-tight connections with the nanoreactor. The system was tested with the (de)hydrogenation of Pd at pressures up to 4.5 bar. The Pd film consisted of islands being 15 nm thick and 50–500 nm wide. In electron diffraction mode we observed reproducibly a crystal lattice expansion and shrinkage owing to hydrogenation and dehydrogenation, respectively. In selected-area electron diffraction and bright/dark-field modes the (de)hydrogenation of individual Pd particles was followed. Some Pd islands are consistently hydrogenated faster than others. When thermally cycled, thermal hysteresis of about 10–16 °C between hydrogen absorption and desorption was observed for hydrogen pressures of 0.5–4.5 bar. Experiments at 0.8 bar and 3.2 bar showed that the (de)hydrogenation temperature is not affected by the electron beam. This result shows that this is a fast method to investigate hydrogen storage materials with information at the nanometer scale. -- Highlights: ► In-situ TEM experiments up to 4.5 bar. ► In-situ TEM on a hydrogen storage material at pressures used in practice. ► No electron beam effect on (de)hydrogenation. ► In-situ TEM allows for fast screening of hydrogen storage materials.

  5. Integrated model for providing tactical emergency medicine support (TEMS): analysis of 120 tactical situations.

    Science.gov (United States)

    Vainionpää, T; Peräjoki, K; Hiltunen, T; Porthan, K; Taskinen, A; Boyd, J; Kuisma, M

    2012-02-01

    Various models for organising tactical emergency medicine support (TEMS) in law enforcement operations exist. In Helsinki, TEMS is organised as an integral part of emergency medical service (EMS) and applied in hostage, siege, bomb threat and crowd control situations and in other tactical situations after police request. Our aim was to analyse TEMS operations, patient profile, and the level of on-site care provided. We conducted a retrospective cohort study of TEMS operations in Helsinki from 2004 to 2009. Data were retrieved from EMS, hospital and dispatching centre files and from TEMS reports. One hundred twenty TEMS operations were analysed. Median time from dispatching to arrival on scene was 10 min [Interquartile Range (IQR) 7-14]. Median duration of operations was 41 min (IQR 19-63). Standby was the only activity in 72 operations, four patients were dead on arrival, 16 requests were called off en route and patient examination or care was needed in 28 operations. Twenty-eight patients (records retrieved) were alive on arrival and were classified as trauma (n = 12) or medical (n = 16). Of traumas, two sustained a gunshot wound, one sustained a penetrating abdominal wound, three sustained medium severity injuries and nine sustained minor injuries. There was neither on-scene nor in-hospital mortality among patients who were alive on arrival. The level of on-site care performed was basic life support in all cases. The results showed that TEMS integrated to daily EMS services including safe zone working only was a feasible, rapid and efficient way to provide medical support to law enforcement operations. © 2011 The Authors Acta Anaesthesiologica Scandinavica © 2011 The Acta Anaesthesiologica Scandinavica Foundation.

  6. Chemical Reactions of Molecules Promoted and Simultaneously Imaged by the Electron Beam in Transmission Electron Microscopy.

    Science.gov (United States)

    Skowron, Stephen T; Chamberlain, Thomas W; Biskupek, Johannes; Kaiser, Ute; Besley, Elena; Khlobystov, Andrei N

    2017-08-15

    The main objective of this Account is to assess the challenges of transmission electron microscopy (TEM) of molecules, based on over 15 years of our work in this field, and to outline the opportunities in studying chemical reactions under the electron beam (e-beam). During TEM imaging of an individual molecule adsorbed on an atomically thin substrate, such as graphene or a carbon nanotube, the e-beam transfers kinetic energy to atoms of the molecule, displacing them from equilibrium positions. Impact of the e-beam triggers bond dissociation and various chemical reactions which can be imaged concurrently with their activation by the e-beam and can be presented as stop-frame movies. This experimental approach, which we term ChemTEM, harnesses energy transferred from the e-beam to the molecule via direct interactions with the atomic nuclei, enabling accurate predictions of bond dissociation events and control of the type and rate of chemical reactions. Elemental composition and structure of the reactant molecules as well as the operating conditions of TEM (particularly the energy of the e-beam) determine the product formed in ChemTEM processes, while the e-beam dose rate controls the reaction rate. Because the e-beam of TEM acts simultaneously as a source of energy for the reaction and as an imaging tool monitoring the same reaction, ChemTEM reveals atomic-level chemical information, such as pathways of reactions imaged for individual molecules, step-by-step and in real time; structures of illusive reaction intermediates; and direct comparison of catalytic activity of different transition metals filmed with atomic resolution. Chemical transformations in ChemTEM often lead to previously unforeseen products, demonstrating the potential of this method to become not only an analytical tool for studying reactions, but also a powerful instrument for discovery of materials that can be synthesized on preparative scale.

  7. Minimum depth of investigation for grounded-wire TEM due to self-transients

    Science.gov (United States)

    Zhou, Nannan; Xue, Guoqiang

    2018-05-01

    The grounded-wire transient electromagnetic method (TEM) has been widely used for near-surface metalliferous prospecting, oil and gas exploration, and hydrogeological surveying in the subsurface. However, it is commonly observed that such TEM signal is contaminated by the self-transient process occurred at the early stage of data acquisition. Correspondingly, there exists a minimum depth of investigation, above which the observed signal is not applicable for reliable data processing and interpretation. Therefore, for achieving a more comprehensive understanding of the TEM method, it is necessary to perform research on the self-transient process and moreover develop an approach for quantifying the minimum detection depth. In this paper, we first analyze the temporal procedure of the equivalent circuit of the TEM method and present a theoretical equation for estimating the self-induction voltage based on the inductor of the transmitting wire. Then, numerical modeling is applied for building the relationship between the minimum depth of investigation and various properties, including resistivity of the earth, offset, and source length. It is guide for the design of survey parameters when the grounded-wire TEM is applied to the shallow detection. Finally, it is verified through applications to a coal field in China.

  8. Structure and Output Characteristics of a TEM Array Fitted to a Fin Heat Exchanger

    Science.gov (United States)

    Zhang, Z.; Chen, L. N.; Chen, Z. J.; Xiao, G. Q.; Liu, Z. J.

    2015-06-01

    In the design of a thermoelectric generator, both the heat transfer area and the number of thermoelectric modules (TEMs) should be increased accordingly as the generator power increases; crucially, both aspects need to be coordinated. A kilowatt thermoelectric generator with a fin heat exchanger is proposed for use in a constant-speed diesel generator unit. Interior fins enhance convective heat transfer, whereas an exterior fin segment increases the heat transfer area. The heat transfer surface is double that of a plane heat exchanger, and the temperature field over the exterior fins is constrained to a one-dimensional distribution. Between adjoining exterior fins, there is a cooling water channel with trapezoid cross-section, enabling compact TEMs and cooling them. Hence, more TEMs are built as a series-parallel array of TEMs with lower resistance and more stable output current. Under nonuniform conditions, to prevent circulation and energy loss, bypass diodes and antidiodes are added. Experiments and numerical calculations show that, with matching and optimization of the heat exchanger and TEM array, a stable maximum output power is obtainable from the interior of the thermoelectric generator system, which can be connected to an external maximum power point tracking system.

  9. A preliminary study of CdS for solar cells using combined TEM and cathodoluminescence

    International Nuclear Information System (INIS)

    Mam, K.; Durose, K.; Halliday, D.P.; Szczerbakow, A.

    2005-01-01

    A study of the suitability of a combined transmission electron microscope (TEM)/cathodoluminescence (CL) imaging and spectroscopy apparatus for investigations of CdS is presented. Photoluminescence (PL) was used to evaluate the effect of the Ar + and I + ion beam thinning used in TEM specimen preparation of CdS: a minor increase in yellow emission (594 nm) resulted. However, excitation of luminescence spectra in the TEM had a quenching effect on red luminescence (734 nm), this being considered due to the high excitation density compared to that in PL. Significant electron beam damage to the CdS could be avoided by using scanning transmission electron microscope (STEM) illumination in preference to the conventional TEM mode, which generally uses higher beam current density. Dislocation images were correlated with contrast in the STEM-CL imaging mode. The potential of the apparatus to make further direct correlations of CL images with diffraction contrast TEM imaging was assessed using the Rose visibility criterion

  10. Microscopy techniques in flavivirus research.

    Science.gov (United States)

    Chong, Mun Keat; Chua, Anthony Jin Shun; Tan, Terence Tze Tong; Tan, Suat Hoon; Ng, Mah Lee

    2014-04-01

    The Flavivirus genus is composed of many medically important viruses that cause high morbidity and mortality, which include Dengue and West Nile viruses. Various molecular and biochemical techniques have been developed in the endeavour to study flaviviruses. However, microscopy techniques still have irreplaceable roles in the identification of novel virus pathogens and characterization of morphological changes in virus-infected cells. Fluorescence microscopy contributes greatly in understanding the fundamental viral protein localizations and virus-host protein interactions during infection. Electron microscopy remains the gold standard for visualizing ultra-structural features of virus particles and infected cells. New imaging techniques and combinatory applications are continuously being developed to push the limit of resolution and extract more quantitative data. Currently, correlative live cell imaging and high resolution three-dimensional imaging have already been achieved through the tandem use of optical and electron microscopy in analyzing biological specimens. Microscopy techniques are also used to measure protein binding affinities and determine the mobility pattern of proteins in cells. This chapter will consolidate on the applications of various well-established microscopy techniques in flavivirus research, and discuss how recently developed microscopy techniques can potentially help advance our understanding in these membrane viruses. Copyright © 2013 Elsevier Ltd. All rights reserved.

  11. Fluorescence confocal microscopy for pathologists.

    Science.gov (United States)

    Ragazzi, Moira; Piana, Simonetta; Longo, Caterina; Castagnetti, Fabio; Foroni, Monica; Ferrari, Guglielmo; Gardini, Giorgio; Pellacani, Giovanni

    2014-03-01

    Confocal microscopy is a non-invasive method of optical imaging that may provide microscopic images of untreated tissue that correspond almost perfectly to hematoxylin- and eosin-stained slides. Nowadays, following two confocal imaging systems are available: (1) reflectance confocal microscopy, based on the natural differences in refractive indices of subcellular structures within the tissues; (2) fluorescence confocal microscopy, based on the use of fluorochromes, such as acridine orange, to increase the contrast epithelium-stroma. In clinical practice to date, confocal microscopy has been used with the goal of obviating the need for excision biopsies, thereby reducing the need for pathological examination. The aim of our study was to test fluorescence confocal microscopy on different types of surgical specimens, specifically breast, lymph node, thyroid, and colon. The confocal images were correlated to the corresponding histological sections in order to provide a morphologic parallel and to highlight current limitations and possible applications of this technology for surgical pathology practice. As a result, neoplastic tissues were easily distinguishable from normal structures and reactive processes such as fibrosis; the use of fluorescence enhanced contrast and image quality in confocal microscopy without compromising final histologic evaluation. Finally, the fluorescence confocal microscopy images of the adipose tissue were as accurate as those of conventional histology and were devoid of the frozen-section-related artefacts that can compromise intraoperative evaluation. Despite some limitations mainly related to black/white images, which require training in imaging interpretation, this study confirms that fluorescence confocal microscopy may represent an alternative to frozen sections in the assessment of margin status in selected settings or when the conservation of the specimen is crucial. This is the first study to employ fluorescent confocal microscopy on

  12. Inter- and intragranular plasticity mechanisms in ultrafine-grained Al thin films: An in situ TEM study

    International Nuclear Information System (INIS)

    Mompiou, F.; Legros, M.; Boé, A.; Coulombier, M.; Raskin, J.-P.; Pardoen, T.

    2013-01-01

    The nature of the elementary deformation mechanisms in small-grained metals has been the subject of numerous recent studies. In the submicron range, mechanisms other than intragranular dislocation mechanisms, such as grain boundary (GB)-based mechanisms, are active and can explain the deviations from the Hall–Petch law. Here, we report observations performed during in situ transmission electron microscopy (TEM) tensile tests on initially dislocation-free Al thin films with a mean grain size around 250 nm prepared by microfabrication techniques. Intergranular plasticity is activated at the onset of plasticity. It consists of the motion of dislocations in the GB plane irrespective of the GB character. Surface imperfections, such as GB grooves, are supposed to trigger intergranular plasticity. At larger deformations, the motion of the intergranular dislocations leads to GB sliding and eventually cavitation. In the meantime, GB stress-assisted migration and dislocation emission inside the grain from GB sources have also been observed. The observation of these different mechanisms during the deformation provides an important insight into the understanding of the mechanical properties of metallic thin films.

  13. Moessbauer, TEM/SAED and XRD investigation on waste dumps of the Valea lui Stan gold mines

    Energy Technology Data Exchange (ETDEWEB)

    Constantinescu, Serban Grigore, E-mail: sconst@infim.ro [National Institute of Materials Physics, Bucharest-Magurele (Romania); Udubasa, Sorin S.; Udubasa, Gheorghe [University of Bucharest, Fac. of Geology and Geophysics (Romania); Kuncser, Victor; Popescu-Pogrion, Nicoleta; Mercioniu, Ionel; Feder, Marcel [National Institute of Materials Physics, Bucharest-Magurele (Romania)

    2012-03-15

    The complementary investigation techniques, Moessbauer spectroscopy, transmission electron microscopy with selected area electron diffraction (TEM/SAED), X-ray diffraction (XRD) have been used to investigate the fate of the Valea lui Stan, Romania, gold-ore nanoscale-minerals during the long time of residence in the waste dumps. The preliminary investigations showed such waste dumps to contain significant amount of metals which cannot be identified by conventional methods. An intense research activity started up in order to evaluate the possibilities to recycle Valea lui Stan waste dumps and to recover metals by chemical or phytoextraction procedures. The waste dumps naturally show different mineral constituents with clay minerals as major phases, observed by XRD-technique. Although the waste dumps materials have whitish-yellowish colours, MOeSSBAUER technique evidences the presence of the finely dispersed iron bearing minerals. The authors are focusing to inspect and analyze Fe-compounds in the samples collected from Valea lui Stan's waste dumps in order to identify the magnetic phases by Moessbauer technique.

  14. In Situ TEM Investigation of the Electrochemical Behavior in CNTs/MnO2-Based Energy Storage Devices.

    Science.gov (United States)

    Tsai, Tsung-Chun; Huang, Guan-Min; Huang, Chun-Wei; Chen, Jui-Yuan; Yang, Chih-Chieh; Tseng, Tseung-Yuen; Wu, Wen-Wei

    2017-09-19

    Transition metal oxides have attracted much interest owing to their ability to provide high power density in lithium batteries; therefore, it is important to understand the electrochemical behavior and mechanism of lithiation-delithiation processes. In this study, we successfully and directly observed the structural evolution of CNTs/MnO 2 during the lithiation process using transmission electron microscopy (TEM). CNTs/MnO 2 were selected due to their high surface area and capacitance effect, and the lithiation mechanism of the CNT wall expansion was systematically analyzed. Interestingly, the wall spacings of CNTs/MnO 2 and CNTs were obviously expanded by 10.92% and 2.59%, respectively. The MnO 2 layer caused structural defects on the CNTs surface that could allow penetration of Li + and Mn 4+ through the tube wall and hence improve the ionic transportation speed. This study provided direct evidence for understanding the role of CNTs/MnO 2 in the lithiation process used in lithium ion batteries and also offers potential benefits for applications and development of supercapacitors.

  15. FE-SEM, FIB and TEM Study of Surface Deposits of Apollo 15 Green Glass Volcanic Spherules

    Science.gov (United States)

    Ross, Daniel K.; Thomas-Keprta, K. L.; Rahman, Z.; Wentworth, S. J.; McKay, D. S.

    2011-01-01

    Surface deposits on lunar pyroclastic green (Apollo 15) and orange (Apollo 17) glass spherules have been attributed to condensation from the gas clouds that accompanied fire-fountain eruptions. The fire fountains cast molten lava high above the lunar surface and the silicate melt droplets quenched before landing producing the glass beads. Early investigations showed that these deposits are rich in sulfur and zinc. The deposits are extremely fine-grained and thin, so that it was never possible to determine their chemical compositions cleanly by SEM/EDX or electron probe x-ray analysis because most of the excited volume was in the under-lying silicate glass. We are investigating the surface deposits by TEM, using focused ion beam (FIB) microscopy to extract and thin the surface deposits. Here we report on chemical mapping of a FIB section of surface deposits of an Apollo green glass bead 15401using the ultra-high resolution JEOL 2500 STEM located at NASA Johnson Space Center.

  16. In situ measurements and transmission electron microscopy of carbon nanotube field-effect transistors

    International Nuclear Information System (INIS)

    Kim, Taekyung; Kim, Seongwon; Olson, Eric; Zuo Jianmin

    2008-01-01

    We present the design and operation of a transmission electron microscopy (TEM)-compatible carbon nanotube (CNT) field-effect transistor (FET). The device is configured with microfabricated slits, which allows direct observation of CNTs in a FET using TEM and measurement of electrical transport while inside the TEM. As demonstrations of the device architecture, two examples are presented. The first example is an in situ electrical transport measurement of a bundle of carbon nanotubes. The second example is a study of electron beam radiation effect on CNT bundles using a 200 keV electron beam. In situ electrical transport measurement during the beam irradiation shows a signature of wall- or tube-breakdown. Stepwise current drops were observed when a high intensity electron beam was used to cut individual CNT bundles in a device with multiple bundles

  17. Dynamics of soft Nanomaterials captured by transmission electron microscopy in liquid water

    Energy Technology Data Exchange (ETDEWEB)

    Proetto, Maria T.; Rush, Anthony M.; Chien, Miao-Ping; Abellan Baeza, Patricia; Patterson, Joseph P.; Thompson, Matthew P.; Olson, Norman H.; Moore, Curtis E.; Rheingold, Arnold L.; Andolina, Christopher; Millstone, Jill; Howell, Stephen B.; Browning, Nigel D.; Evans, James E.; Gianneschi, Nathan C.

    2014-01-14

    In this paper we present in situ transmission electron microscopy (TEM) of soft, synthetic nanoparticles with a comparative analysis using conventional TEM methods. This comparison is made with the simple aim of describing what is an unprecedented example of in situ imaging by TEM. However, we contend the technique will quickly become essential in the characterization of analogous systems, especially where dynamics are of interest in the solvated state. In this case, particles were studied which were obtained from the direct polymerization of an oxaliplatin analog, designed for an ongoing program in novel chemotherapeutic delivery systems. The resulting nanoparticles provided sufficient contrast for facile imaging in situ, and point toward key design parameters that enable this new characterization approach for organic nanomaterials. We describe the preparation of the synthetic micellar nanoparticles to- gether with their characterization in liquid water.

  18. Transmission electron microscopy study of Listeria monocytogenes serotype 1/2a cells exposed to sublethal heat stress and carvacrol

    Science.gov (United States)

    The objective of this study was to investigate the morphological changes that occurred in Listeria monocytogenes serotype 1/2a cells as visualized by transmission electron microscopy (TEM) after exposure to sublethal heat stress at 48°C for 60 min and in combination with lethal concentration of carv...

  19. Effects of Topography in Nano-Structured Thin Films : A Lorentz Transmission Electron Microscopy and Electron Holography Study

    NARCIS (Netherlands)

    Hosson, Jeff Th.M. De; Raedt, Hans A. De

    2003-01-01

    This paper aims at applying advanced transmission electron microscopy (TEM) to functional materials, such as ultra-soft magnetic films for high-frequency inductors, to reveal the structure-property relationship. The ultimate goal is to delineate a more quantitative way to obtain information of the

  20. A Structural Study of Escherichia coli Cells Using an In Situ Liquid Chamber TEM Technology

    Directory of Open Access Journals (Sweden)

    Yibing Wang

    2015-01-01

    Full Text Available Studying cell microstructures and their behaviors under living conditions has been a challenging subject in microbiology. In this work, in situ liquid chamber TEM was used to study structures of Escherichia coli cells in aqueous solutions at a nanometer-scale resolution. Most of the cells remained intact under electron beam irradiation, and nanoscale structures were observed during the TEM imaging. The analysis revealed structures of pili surrounding the E. coli cells; the movements of the pili in the liquid were also observed during the in situ tests. This technology also allowed the observation of features of the nucleoid in the E. coli cells. Overall, in situ TEM can be applied as a valuable tool to study real-time microscopic structures and processes in microbial cells residing in native aqueous solutions.

  1. In situ mechanical TEM: seeing and measuring under stress with electrons

    International Nuclear Information System (INIS)

    Legros, M.

    2014-01-01

    From the first observation of moving dislocations in 1956 to the latest developments of piezo-actuated sample holders and direct electron sensing cameras in modern transmission electron microscopes (TEM), in situ mechanical testing has brought an unequaled view of the involved mechanisms during the plastic deformation of materials. Although MEMS-based or load-cell equipped holders provide an almost direct measure of these quantities, deriving stress and strain from in situ TEM experiments has an extensive history. Nowadays, the realization of a complete mechanical test while observing the evolution of a dislocation structure is possible, and it constitutes the perfect combination to explore size effects in plasticity. New cameras, data acquisition rates and intrinsic image-related techniques, such as holography, should extend the efficiency and capabilities of in situ deformation inside a TEM. (author)

  2. Analysis and design of a coupled coaxial line TEM resonator for magnetic resonance imaging

    International Nuclear Information System (INIS)

    Benahmed, Nasreddine; Feham, Mohammed; Khelif, M'Hamed

    2006-01-01

    In this paper, we have successfully realized a numerical tool to analyse and to design an n-element unloaded coaxial line transverse electromagnetic (TEM) resonator. This numerical tool allows the determination of the primary parameters, matrices [L], [C] and [R], and simulates the frequency response of S 11 at the RF port of the designed TEM resonator. The frequency response permits evaluation of the unloaded quality factor Q 0 . As an application, we present the analysis and the design of an eight-element unloaded TEM resonator for animal studies at 4.7 T. The simulated performance has a -62.81 dB minimum reflection and a quality factor of 260 around 200 MHz

  3. Speciation of uranium in minerals by Sem, Tem, μ-PIXE, XPS and XAFS

    International Nuclear Information System (INIS)

    Toshihiko Ohnuki; Hiroshi Isobe; Tomihiro Kamiya; Takuro Sakai; Takashi Murakami

    2001-01-01

    Many kinds of electromagnetic waves and particle beams are used as analytical probes for the investigation of uranium-mineralogy and speciation. The representatives of the probes are SEM, TEM, μ-PIRE, XPS and XAFS. Each of these analytical probes has its own advantages and disadvantages. We have performed studies to compare the advantages and disadvantages on the basis of the analysis of the distribution and speciation of U containing rock samples collected at the Koongarra uranium deposit, Australia. The spatial resolutions of the probes are in the order of TEM>SEM, μ-PIXE>XFAS, XPS. The lower detection limits of the probes are in the order of μ-PIXE< TEM, SEM< XFAS, XPS. Oxidation state of U was determined by XFAS and XPS. These results indicate that combination of the above probes can give us sufficient data on U speciation not only in natural rock samples but in solid samples obtained in the laboratory. (authors)

  4. Nonlinear interplay of TEM and ITG turbulence and its effect on transport

    Science.gov (United States)

    Merz, F.; Jenko, F.

    2010-05-01

    The dominant source of anomalous transport in fusion plasmas on ion scales is turbulence driven by trapped electron modes (TEMs) and ion temperature gradient (ITG) modes. While the individual properties of each of these two instabilities and the corresponding microturbulence have been examined in detail in the past, the effects of a coexistence of the two modes and the phenomena of transitions between the TEM and ITG dominated regimes are not well studied. In many experimental situations, the temperature and density gradients support both microinstabilities simultaneously, so that transitional regimes are important for a detailed understanding of fusion plasmas. In this paper, this issue is addressed, using the gyrokinetic code GENE for a detailed investigation of the dominant and subdominant linear instabilities and the corresponding nonlinear system. A simple quasilinear model based on eigenvalue computations is presented which is shown to reproduce important features of the nonlinear TEM-ITG transition.

  5. TEMS: an alternative method for the repair of benign recto-vaginal fistulae.

    Science.gov (United States)

    Darwood, R J; Borley, N R

    2008-07-01

    The repair of high recto-vaginal fistula can be challenging since access may be limited via the endo-anal approach yet the alternative trans-abdominal route carries significant morbidity. We report the use of TEMS to repair a recto-vaginal fistula following anterior resection and pelvic radiotherapy. The patient was placed prone and a 25 cm rectoscope was inserted. A proximally based mucosal advancement flap was raised to repair the fistula. The patient was discharged 2 days later and a contrast study confirmed closure of the fistula. COMPARISON WITH OTHER TECHNIQUES: TEMS allows excellent visualisation of a rectovaginal fistula compared to standard endo-anal or trans-vaginal techniques. The morbidity is lower than the trans-abdominal route. TEMS is a useful technique for the repair of benign recto-vaginal fistula and has distinct advantages over conventional techniques.

  6. Qualidade de vida do paciente submetido à Microcirurgia Endoscópica Transanal (TEM Quality of life after Transanal Endoscopic Microsurgery (TEM

    Directory of Open Access Journals (Sweden)

    Roberto da Silveira Moraes

    2007-03-01

    Full Text Available RACIONAL: A Microcirurgia Endoscópica Transanal (TEM é procedimento minimamente invasivo para o tratamento de tumores retais selecionados. Atualmente, existe crescente interesse médico na medida quantitativa da qualidade de vida. OBJETIVO: Avaliar a qualidade de vida dos pacientes submetidos a TEM no Serviço de Cirurgia do Aparelho Digestivo no Hospital de Clínicas da Universidade Federal do Paraná. MÉTODOS: Trata-se de um estudo observacional prospectivo e de coorte da avaliação da qualidade de vida após TEM. Trinta e quatro pacientes responderam a um questionário composto de 14 questões, abordando aspectos pós-operatórios e laborais. Dirigiam-se elas para levantar dados principalmente sobre: o consentimento informado; a dor experimentada após a operação; a capacidade de o paciente caminhar no período pós-operatório; o período para retorno às atividades habituais; a satisfação com a ausência de cicatriz pós-operatória; a incontinência no pós-operatório; se recomendaria a operação a um familiar ou conhecido. RESULTADOS: Todos os 34 pacientes relataram ter sido adequadamente informados sobre o procedimento. Ausência de dor pós-operatória foi observada em 82,5% e todos se mostraram capazes de deambular no 1º dia do pós-operatório. O retorno às atividades habituais deu-se em média sete dias após o procedimento. Somente cinco pacientes (14,70% apresentaram incontinência fecal transitória, não maior que uma semana. Três pacientes (8,82% necessitaram de re-internação, sendo dois por tumores residuais e outro por recidiva tumoral. Dois pacientes (5,88% referiram modificação temporária na vida sexual após a cirurgia e 97,05% indicariam a TEM a um familiar ou amigo. O período médio de internação foi de três dias. CONCLUSÃO: Os pacientes apresentaram boa evolução, com pouca dor pós-operatória, curto período de internação e baixo índice de complicações, mostrando satisfação e adequada

  7. "One-sample concept" micro-combinatory for high throughput TEM of binary films.

    Science.gov (United States)

    Sáfrán, György

    2018-04-01

    Phases of thin films may remarkably differ from that of bulk. Unlike to the comprehensive data files of Binary Phase Diagrams [1] available for bulk, complete phase maps for thin binary layers do not exist. This is due to both the diverse metastable, non-equilibrium or instable phases feasible in thin films and the required volume of characterization work with analytical techniques like TEM, SAED and EDS. The aim of the present work was to develop a method that remarkably facilitates the TEM study of the diverse binary phases of thin films, or the creation of phase maps. A micro-combinatorial method was worked out that enables both preparation and study of a gradient two-component film within a single TEM specimen. For a demonstration of the technique thin Mn x Al 1- x binary samples with evolving concentration from x = 0 to x = 1 have been prepared so that the transition from pure Mn to pure Al covers a 1.5 mm long track within the 3 mm diameter TEM grid. The proposed method enables the preparation and study of thin combinatorial samples including all feasible phases as a function of composition or other deposition parameters. Contrary to known "combinatorial chemistry", in which a series of different samples are deposited in one run, and investigated, one at a time, the present micro-combinatorial method produces a single specimen condensing a complete library of a binary system that can be studied, efficiently, within a single TEM session. That provides extremely high throughput for TEM characterization of composition-dependent phases, exploration of new materials, or the construction of phase diagrams of binary films. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. 2.5D Modeling of TEM Data Applied to Hidrogeological Studies in PARANÁ Basin, Brazil

    Science.gov (United States)

    Bortolozo, C. A.; Porsani, J. L.; Santos, F. M.

    2013-12-01

    The transient electromagnetic method (TEM) is used all over the world and has shown great potential in hydrological, hazardous waste site characterization, mineral exploration, general geological mapping, and geophysical reconnaissance. However, the behavior of TEM fields are very complex and is not yet fully understood. Forward modeling is one of the most common and effective methods to understand the physical behavior and significance of the electromagnetics responses of a TEM sounding. Until now, there are a limited number of solutions for the 2D forward problem for TEM. More rare are the descriptions of a three-component response of a 3D source over 2D earth, which is the so-called 2.5D. The 2.5D approach is more realistic than the conventional 2D source previous used, once normally the source cannot be realistic represented for a 2D approximation (normally source are square loops). At present the 2.5D model represents the only way of interpreting TEM data in terms of a complex earth, due to the prohibitive amount of computer time and storage required for a full 3D model. In this work we developed a TEM modeling program for understanding the different responses and how the magnetic and electric fields, produced by loop sources at air-earth interface, behave in different geoelectrical distributions. The models used in the examples are proposed focusing hydrogeological studies, once the main objective of this work is for detecting different kinds of aquifers in Paraná sedimentary basin, in São Paulo State - Brazil. The program was developed in MATLAB, a widespread language very common in the scientific community.

  9. Processing grounded-wire TEM signal in time-frequency-pseudo-seismic domain: A new paradigm

    Science.gov (United States)

    Khan, M. Y.; Xue, G. Q.; Chen, W.; Huasen, Z.

    2017-12-01

    Grounded-wire TEM has received great attention in mineral, hydrocarbon and hydrogeological investigations for the last several years. Conventionally, TEM soundings have been presented as apparent resistivity curves as function of time. With development of sophisticated computational algorithms, it became possible to extract more realistic geoelectric information by applying inversion programs to 1-D & 3-D problems. Here, we analyze grounded-wire TEM data by carrying out analysis in time, frequency and pseudo-seismic domain supported by borehole information. At first, H, K, A & Q type geoelectric models are processed using a proven inversion program (1-D Occam inversion). Second, time-to-frequency transformation is conducted from TEM ρa(t) curves to magneto telluric MT ρa(f) curves for the same models based on all-time apparent resistivity curves. Third, 1-D Bostick's algorithm was applied to the transformed resistivity. Finally, EM diffusion field is transformed into propagating wave field obeying the standard wave equation using wavelet transformation technique and constructed pseudo-seismic section. The transformed seismic-like wave indicates that some reflection and refraction phenomena appear when the EM wave field interacts with geoelectric interface at different depth intervals due to contrast in resistivity. The resolution of the transformed TEM data is significantly improved in comparison to apparent resistivity plots. A case study illustrates the successful hydrogeophysical application of proposed approach in recovering water-filled mined-out area in a coal field located in Ye county, Henan province, China. The results support the introduction of pseudo-seismic imaging technology in short-offset version of TEM which can also be an useful aid if integrated with seismic reflection technique to explore possibilities for high resolution EM imaging in future.

  10. Direct nanofabrication and transmission electron microscopy on a suite of easy-to-prepare ultrathin film substrates

    International Nuclear Information System (INIS)

    Allred, Daniel B.; Zin, Melvin T.; Ma, Hong; Sarikaya, Mehmet; Baneyx, Francois; Jen, Alex K.-Y.; Schwartz, Daniel T.

    2007-01-01

    A high-yield, easy to master method for preparing electron transparent metal, oxide, and carbon ultrathin film substrates suitable for direct nano/micro-fabrication and transmission electron microscopy (TEM) is presented. To demonstrate the versatility of these substrates for fabrication processes, we use e-beam lithography, self-assembled colloidal and protein templates, and microcontact printing to create patterned masks for subsequent electrodeposition of two dimensional and three dimensional structures. The electrodeposited structures range in scale from a few nanometers to a few micrometers in characteristic dimensions. Because fabrication occurs directly on ultrathin films, TEM analysis of the resulting materials and buried interfaces is straightforward without any destructive sample preparation. We show that all the normal TEM analytical methods (imaging, diffraction, electron and X-ray spectroscopies) are compatible with the fabricated structures and the thin film substrates. These electron transparent substrates have largely rendered the need for TEM sample preparation on fabricated structures obsolete in our lab

  11. Quantitative Transmission Electron Microscopy of Nanoparticles and Thin-Film Formation in Electroless Metallization of Polymeric Surfaces

    Science.gov (United States)

    Dutta, Aniruddha; Heinrich, Helge; Kuebler, Stephen; Grabill, Chris; Bhattacharya, Aniket

    2011-03-01

    Gold nanoparticles(Au-NPs) act as nucleation sites for electroless deposition of silver on functionalized SU8 polymeric surfaces. Here we report the nanoscale morphology of Au and Ag nanoparticles as studied by Transmission Electron Microscopy (TEM). Scanning TEM with a high-angle annular dark-field detector is used to obtain atomic number contrast. From the intensity-calibrated plan-view scanning TEM images we determine the mean thickness and the volume distribution of the Au-NPs on the surface of the functionalized polymer. We also report the height and the radius distribution of the gold nanoparticles obtained from STEM images taking into consideration the experimental errors. The cross sectional TEM images yield the density and the average distance of the Au and Ag nanoparticles on the surface of the polymer. Supported by grant NSF, Chemistry Division.

  12. Illuminating Electron Microscopy of Photocatalysts

    DEFF Research Database (Denmark)

    Cavalca, Filippo

    specimen holder capable of shining light onto samples inside the TEM. The holder contains a laser diode and an optical system that guides light onto a sample with maximum power transmission. The source can be changed and tuned, in principle spanning the whole visible and UV spectrum. It is possible to use...... present preliminary results from Cu2O nanocubes, which show the effect of photodegradation under visible light exposure....

  13. Quantitative in situ TEM tensile testing of an individual nickel nanowire

    International Nuclear Information System (INIS)

    Lu Yang; Peng Cheng; Ganesan, Yogeeswaran; Lou Jun; Huang Jianyu

    2011-01-01

    In this paper, we have demonstrated the usage of a novel micro-mechanical device (MMD) to perform quantitative in situ tensile tests on individual metallic nanowires inside a transmission electron microscope (TEM). Our preliminary experiment on a 360 nm diameter nickel nanowire showed that the sample fractured at an engineering stress of ∼ 1.2 GPa and an engineering strain of ∼ 4%, which is consistent with earlier experiments performed inside a scanning electron microscope (SEM). With in situ high resolution TEM imaging and diffraction capabilities, this novel experimental set-up could provide unique opportunities to reveal the underlying deformation and damage mechanisms for metals at the nanoscale.

  14. Combined interpretation of SkyTEM and high-resolution seismic data

    DEFF Research Database (Denmark)

    Høyer, Anne-Sophie; Lykke-Andersen, Holger; Jørgensen, Flemming Voldum

    2011-01-01

    made based on AEM (SkyTEM) and high-resolution seismic data from an area covering 10 km2 in the western part of Denmark. As support for the interpretations, an exploration well was drilled to provide lithological and logging information in the form of resistivity and vertical seismic profiling. Based...... on the resistivity log, synthetic SkyTEM responses were calculated with a varying number of gate-times in order to illustrate the effect of the noise-level. At the exploration well geophysical data were compared to the lithological log; in general there is good agreement. The same tendency was recognised when Sky...

  15. El juego temático de roles sociales: aportes al desarrollo en la edad preescolar

    OpenAIRE

    González Moreno, Claudia Ximena; Solovieva, Yulia; Quintanar Rojas, Luis

    2014-01-01

    El juego temático de roles sociales es importante en la educación inicial porque posibilita el desarrollo de la actividad simbólica, voluntaria, reflexiva, comunicativa desplegada e imaginativa. Estas son formaciones psicológicas que garantizan el aprendizaje en la edad escolar. En este artículo se presenta una reflexión acerca de la necesidad de utilizar el juego temático de roles sociales en las aulas de preescolar,1 por su efecto en la promoción de habilidades y en la prevención de dificul...

  16. Determination of crystallographic and macroscopic orientation of planar structures in TEM

    DEFF Research Database (Denmark)

    Huang, X.; Liu, Q.

    1998-01-01

    With the aid of a double-tilt holder in a transmission electron microscope (TEM), simple methods are described for determination of the crystallographic orientation of a planar structure and for calculation of the macroscopic orientation of the planar structure. The correlation between a planar...... structure and a crystallographic plane can be found by comparing the differences in their trace directions on the projection plane and inclination angles with respect to that plane. The angles between the traces of planar structures and the sample axis measured from the TEM micrographs, which have been...

  17. Scanning Tunneling Microscopy - image interpretation

    International Nuclear Information System (INIS)

    Maca, F.

    1998-01-01

    The basic ideas of image interpretation in Scanning Tunneling Microscopy are presented using simple quantum-mechanical models and supplied with examples of successful application. The importance is stressed of a correct interpretation of this brilliant experimental surface technique

  18. Introducing measure-by-wire, the systematic use of systems and control theory in transmission electron microscopy

    International Nuclear Information System (INIS)

    Tejada, Arturo; Dekker, Arnold J. den; Van den Broek, Wouter

    2011-01-01

    Transmission electron microscopes (TEMs) are the tools of choice for academic and industrial research at the nano-scale. Due to their increasing use for routine, repetitive measurement tasks (e.g., quality control in production lines) there is a clear need for a new generation of high-throughput microscopes designed to autonomously extract information from specimens (e.g., particle size distribution, chemical composition, structural information, etc.). To aid in their development, a new engineering perspective on TEM design, based on principles from systems and control theory, is proposed here: measure-by-wire (not to be confused with remote microscopy). Under this perspective, the TEM operator yields the direct control of the microscope's internal processes to a hierarchy of feedback controllers and high-level supervisors. These make use of dynamical models of the main TEM components together with currently available measurement techniques to automate processes such as defocus correction or specimen displacement. Measure-by-wire is discussed in depth, and its methodology is illustrated through a detailed example: the design of a defocus regulator, a type of feedback controller that is akin to existing autofocus procedures. -- Highlights: ► High-throughput TEM operation is increasingly needed for research and industry. ► Autonomous high-throughput TEMs enabled by systems and control theory. ► Measure-by-wire is a new holistic automation oriented engineering view of TEM. ► A detailed example shows how to apply MBW to the automatic control of defocus.

  19. Transmission electron microscopy, fluorescence microscopy, and confocal raman microscopic analysis of ultrastructural and compositional heterogeneity of Cornus alba L. wood cell wall.

    Science.gov (United States)

    Ma, Jianfeng; Ji, Zhe; Zhou, Xia; Zhang, Zhiheng; Xu, Feng

    2013-02-01

    Transmission electron microscopy (TEM), fluorescence microscopy, and confocal Raman microscopy can be used to characterize ultrastructural and compositional heterogeneity of plant cell walls. In this study, TEM observations revealed the ultrastructural characterization of Cornus alba L. fiber, vessel, axial parenchyma, ray parenchyma, and pit membrane between cells, notably with the ray parenchyma consisting of two well-defined layers. Fluorescence microscopy evidenced that cell corner middle lamella was more lignified than adjacent compound middle lamella and secondary wall with variation in lignification level from cell to cell. In situ Raman images showed that the inhomogeneity in cell wall components (cellulose and lignin) among different cells and within morphologically distinct cell wall layers. As the significant precursors of lignin biosynthesis, the pattern of coniferyl alcohol and aldehyde (joint abbreviation Lignin-CAA for both structures) distribution in fiber cell wall was also identified by Raman images, with higher concentration occurring in the fiber secondary wall where there was the highest cellulose concentration. Moreover, noteworthy was the observation that higher concentration of lignin and very minor amounts of cellulose were visualized in the pit membrane areas. These complementary microanalytical methods provide more accurate and complete information with regard to ultrastructural and compositional characterization of plant cell walls.

  20. Characterization of multilayer nitride coatings by electron microscopy and modulus mapping

    International Nuclear Information System (INIS)

    Pemmasani, Sai Pramod; Rajulapati, Koteswararao V.; Ramakrishna, M.; Valleti, Krishna; Gundakaram, Ravi C.; Joshi, Shrikant V.

    2013-01-01

    This paper discusses multi-scale characterization of physical vapour deposited multilayer nitride coatings using a combination of electron microscopy and modulus mapping. Multilayer coatings with a triple layer structure based on TiAlN and nanocomposite nitrides with a nano-multilayered architecture were deposited by Cathodic arc deposition and detailed microstructural studies were carried out employing Energy Dispersive Spectroscopy, Electron Backscattered Diffraction, Focused Ion Beam and Cross sectional Transmission Electron Microscopy in order to identify the different phases and to study microstructural features of the various layers formed as a result of the deposition process. Modulus mapping was also performed to study the effect of varying composition on the moduli of the nano-multilayers within the triple layer coating by using a Scanning Probe Microscopy based technique. To the best of our knowledge, this is the first attempt on modulus mapping of cathodic arc deposited nitride multilayer coatings. This work demonstrates the application of Scanning Probe Microscopy based modulus mapping and electron microscopy for the study of coating properties and their relation to composition and microstructure. - Highlights: • Microstructure of a triple layer nitride coating studied at multiple length scales. • Phases identified by EDS, EBSD and SAED (TEM). • Nanolayered, nanocomposite structure of the coating studied using FIB and TEM. • Modulus mapping identified moduli variation even in a nani-multilayer architecture

  1. Studying the Kinetics of Crystalline Silicon Nanoparticle Lithiation with In Situ Transmission Electron Microscopy

    KAUST Repository

    McDowell, Matthew T.

    2012-09-04

    In situ transmission electron microscopy (TEM) is used to study the electrochemical lithiation of high-capacity crystalline Si nanoparticles for use in Li-ion battery anodes. The lithiation reaction slows down as it progresses into the particle interior, and analysis suggests that this behavior is due not to diffusion limitation but instead to the influence of mechanical stress on the driving force for reaction. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Studying the Kinetics of Crystalline Silicon Nanoparticle Lithiation with In Situ Transmission Electron Microscopy

    KAUST Repository

    McDowell, Matthew T.; Ryu, Ill; Lee, Seok Woo; Wang, Chongmin; Nix, William D.; Cui, Yi

    2012-01-01

    In situ transmission electron microscopy (TEM) is used to study the electrochemical lithiation of high-capacity crystalline Si nanoparticles for use in Li-ion battery anodes. The lithiation reaction slows down as it progresses into the particle interior, and analysis suggests that this behavior is due not to diffusion limitation but instead to the influence of mechanical stress on the driving force for reaction. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Microstructure of NiTi orthodontic wires observations using transmission electron microscopy

    OpenAIRE

    Ferčec, J.; Jenko, D.; Buchmeister, B.; Rojko, F.; Budič, B.; Kosec, B.; Rudolf, R.

    2014-01-01

    This work presents the results of the microstructure observation of six different types of NiTi orthodontic wires by using Transmission Electron Microscopy (TEM). Within these analyses the chemical compositions of each wire were observed in different places by applying the EDS detector. Namely, the chemical composition in the orthodontic wires is very important because it shows the dependence between the phase temperatures and mechanical properties. Microstructure observations showed that ort...

  4. Determination of the Projected Atomic Potential by Deconvolution of the Auto-Correlation Function of TEM Electron Nano-Diffraction Patterns

    Directory of Open Access Journals (Sweden)

    Liberato De Caro

    2016-11-01

    Full Text Available We present a novel method to determine the projected atomic potential of a specimen directly from transmission electron microscopy coherent electron nano-diffraction patterns, overcoming common limitations encountered so far due to the dynamical nature of electron-matter interaction. The projected potential is obtained by deconvolution of the inverse Fourier transform of experimental diffraction patterns rescaled in intensity by using theoretical values of the kinematical atomic scattering factors. This novelty enables the compensation of dynamical effects typical of transmission electron microscopy (TEM experiments on standard specimens with thicknesses up to a few tens of nm. The projected atomic potentials so obtained are averaged on sample regions illuminated by nano-sized electron probes and are in good quantitative agreement with theoretical expectations. Contrary to lens-based microscopy, here the spatial resolution in the retrieved projected atomic potential profiles is related to the finer lattice spacing measured in the electron diffraction pattern. The method has been successfully applied to experimental nano-diffraction data of crystalline centrosymmetric and non-centrosymmetric specimens achieving a resolution of 65 pm.

  5. Monolayer to MTS: using SEM, HIM, TEM and SERS to compare morphology, nanosensor uptake and redox potential in MCF7 cells

    Science.gov (United States)

    Jamieson, L. E.; Bell, A. P.; Harrison, D. J.; Campbell, C. J.

    2015-06-01

    Cellular redox potential is important for the control and regulation of a vast number of processes occurring in cells. When the fine redox potential balance within cells is disturbed it can have serious consequences such as the initiation or progression of disease. It is thought that a redox gradient develops in cancer tumours where the peripheral regions are well oxygenated and internal regions, further from vascular blood supply, become starved of oxygen and hypoxic. This makes treatment of these areas more challenging as, for example, radiotherapy relies on the presence of oxygen. Currently techniques for quantitative analysis of redox gradients are limited. Surface enhanced Raman scattering (SERS) nanosensors (NS) have been used to detect redox potential in a quantitative manner in monolayer cultured cells with many advantages over other techniques. This technique has considerable potential for use in multicellular tumour spheroids (MTS) - a three dimensional (3D) cell model which better mimics the tumour environment and gradients that develop. MTS are a more realistic model of the in vivo cellular morphology and environment and are becoming an increasingly popular in vitro model, replacing traditional monolayer culture. Imaging techniques such as transmission electron microscopy (TEM), scanning electron microscopy (SEM) and helium ion microscopy (HIM) were used to investigate differences in morphology and NS uptake in monolayer culture compared to MTS. After confirming NS uptake, the first SERS measurements revealing quantitative information on redox potential in MTS were performed.

  6. Localised corrosion in aluminium alloy 2024-T3 using in situ TEM

    NARCIS (Netherlands)

    Malladi, S.; Shen, C.; Xu, Q.; De Kruijff, T.; Yücelen, E.; Tichelaar, F.; Zandbergen, H.

    2013-01-01

    An approach to carry out chemical reactions using aggressive gases in situ in a transmission electron microscope (TEM), at ambient pressures of 1.5 bar using a windowed environmental cell, called a nanoreactor, is presented here. The nanoreactor coupled with a specially developed holder with

  7. TEM10 homodyne detection as an optimal small-displacement and tilt-measurement scheme

    DEFF Research Database (Denmark)

    Delaubert, Vincent; Treps, Nikolas; Lassen, Mikael Østergaard

    2006-01-01

    We report an experimental demonstration of optimal measurements of small displacement and tilt of a Gaussian beam - two conjugate variables - involving a homodyne detection with a TEM10 local oscillator. We verify that the standard split detection is only 64% efficient. We also show a displacement...

  8. Directrices para la construcción de un repositorio temático

    Directory of Open Access Journals (Sweden)

    Doria, María Vanesa

    2013-04-01

    Full Text Available La creación de repositorios de información institucionales y/o temáticos, en nuestros días es la clave para el acceso a producción científica de manera libre y abierta. Por lo tanto, el acceso a la información a través de repositorios de información se ve favorecido por las iniciativas que propone el Acceso Abierto (AA. Para la creación de un repositorio de información en el marco de la filosofía de AA es importante contar con directrices, éstas pretenden ser una guía general de aspectos básicos dónde se detallan los pasos necesarios para la creación de un repositorio. El presente trabajo recoge las directrices para la construcción de repositorios temáticos a partir de los siguientes puntos de referencia: finalidad, funciones, políticas y actividades. Aunque existe un consenso sobre que los repositorios temáticos fueron los primeros en aparecer, existe poca información sobre desarrollo y gestión de repositorios temáticos comparado con la amplitud de información alcanzada por repositorios institucionales

  9. An Analysis of Air Force Management of Turbine Engine Monitoring Systems (TEMS).

    Science.gov (United States)

    1980-06-01

    Without their candid insights, this study could not have been completed. The guidance and patience of our thesis chairman, Major Leslie Zambo , whose...its own problems and looking at own piece of the pie . 2. No integration/standardization between TEMS programs. 3. Need better organizational

  10. Optical, mechanical and TEM assessment of titania-doped Bi2V1 ...

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... Home; Journals; Bulletin of Materials Science; Volume 37; Issue 7. Optical, mechanical and TEM assessment of titania-doped Bi2V1−TiO5.5−δ bismuth vanadate oxides. Gurbinder Kaur Gary Pickrell Vishal Kumar Om Prakash Pandey Kulvir Singh Daniel Homa. Volume 37 Issue 7 December 2014 pp ...

  11. Determination of grain size by XRD profile analysis and TEM counting in nano-structured Cu

    International Nuclear Information System (INIS)

    Zhong Yong; Ping Dehai; Song Xiaoyan; Yin Fuxing

    2009-01-01

    In this work, a serial of pure copper sample with different grain sizes from nano- to micro-scale were prepared by sparkle plasma sintering (SPS) and following anneal treatment at 873 K and 1073 K, respectively. The grain size distributions of these samples were determined by both X-ray diffraction (XRD) profile analysis and transmission electronic microscope (TEM) micrograph counting. Although these two methods give similar distributions of grain size in the case of as-SPS sample with nano-scale grain size (around 10 nm), there are apparent discrepancies between the grain size distributions of the annealed samples obtained from XRD and TEM, especially for the sample annealed at 1073 K after SPS with micro-scale grain size (around 2 μm), which TEM counting provides much higher values of grain sizes than XRD analysis does. It indicates that for large grain-sized material, XRD analysis lost its validity for determination of grain size. It might be due to some small sized substructures possibly existed in even annealed (large grain-sized) samples, whereas there is no substructures in as-SPS (nanocrystalline) sample. Moreover, it has been found that the effective outer cut-off radius R e derived from XRD analysis coincides with the grain sizes given by TEM counting. The potential relationship between grain size and R e was discussed in the present work. These results might provide some new hints for deeper understanding of the physical meaning of XRD analysis and the parameters derived.

  12. MICROORGANISMS FOUND IN SECONDARY CATARACT MATERIAL OF ECCE PATIENTS, A STUDY WITH SEM AND TEM

    NARCIS (Netherlands)

    KALICHARAN, D; JONGEBLOED, WL; LOS, LI; WORST, JGF

    1993-01-01

    Globular secondary cataract material, removed from 24 patients with ECCE after ophthalmic cleaning of the anterior capsule, were investigated with SEM and TEM. Besides spherical, somewhat oval shaped bodies of various shape and size comparable with those found in cataractous lenses, (an)aerobic

  13. Automated SEM and TEM sample preparation applied to copper/low k materials

    Science.gov (United States)

    Reyes, R.; Shaapur, F.; Griffiths, D.; Diebold, A. C.; Foran, B.; Raz, E.

    2001-01-01

    We describe the use of automated microcleaving for preparation of both SEM and TEM samples as done by SELA's new MC500 and TEMstation tools. The MC500 is an automated microcleaving tool that is capable of producing cleaves with 0.25 μm accuracy resulting in SEM-ready samples. The TEMstation is capable of taking a sample output from the MC500 (or from SELA's earlier MC200 tool) and producing a FIB ready slice of 25±5 μm, mounted on a TEM-washer and ready for FIB thinning to electron transparency for TEM analysis. The materials selected for the tool set evaluation mainly included the Cu/TaN/HOSP low-k system. The paper is divided into three sections, experimental approach, SEM preparation and analysis of HOSP low-k, and TEM preparation and analysis of Cu/TaN/HOSP low-k samples. For the samples discussed, data is presented to show the quality of preparation provided by these new automated tools.

  14. Double aberration-corrected TEM/STEM of tungstated zirconia nanocatalysts for the synthesis of paracetamol

    International Nuclear Information System (INIS)

    Yoshida, K; Boyes, E D; Gai, P L; Shiju, N R; Brown, D R

    2010-01-01

    We report highly active tungstated zirconia nanocatalysts for the synthesis of paracetamol by Beckmann rearrangement of 4-hydroxyacetophenone oxime. Double aberration-corrected (2AC)-TEM/STEM studies were performed in a JEOL 2200FS FEG TEM/STEM at the 1 Angstrom (1 A = 0.1 nanometer) level. Observations at close to zero defocus were carried out using the AC-TEM as well as AC-STEM including high angle annular dark field (HAADF) imaging, from the same areas of the catalyst crystallites. The studies from the same areas have revealed the location and the nanostructure of the polytungstate species (clusters) and the nanograins of zirconia. The AC (S)TEM was crucial to observe the nanostructure and location of polytungstate clusters on the zirconia grains. Polytungstate clusters as small as 0.5 nm have been identified using the HAADF-STEM. The nanostructures of the catalyst and the W surface density have been correlated with paracetamol reaction studies. The results demonstrate the nature of active sites and high activity of the tungstated zirconia nanocatalyst, which is an environmentally clean alternative to the current homogeneous process.

  15. Double aberration-corrected TEM/STEM of tungstated zirconia nanocatalysts for the synthesis of paracetamol

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, K; Boyes, E D; Gai, P L [York JEOL Nanocentre (United Kingdom); Shiju, N R; Brown, D R, E-mail: pgb500@york.ac.u [Department of Chemical and Biological Sciences, University of Huddersfield, Huddersfield, HD1 3DH (United Kingdom)

    2010-07-01

    We report highly active tungstated zirconia nanocatalysts for the synthesis of paracetamol by Beckmann rearrangement of 4-hydroxyacetophenone oxime. Double aberration-corrected (2AC)-TEM/STEM studies were performed in a JEOL 2200FS FEG TEM/STEM at the 1 Angstrom (1 A = 0.1 nanometer) level. Observations at close to zero defocus were carried out using the AC-TEM as well as AC-STEM including high angle annular dark field (HAADF) imaging, from the same areas of the catalyst crystallites. The studies from the same areas have revealed the location and the nanostructure of the polytungstate species (clusters) and the nanograins of zirconia. The AC (S)TEM was crucial to observe the nanostructure and location of polytungstate clusters on the zirconia grains. Polytungstate clusters as small as 0.5 nm have been identified using the HAADF-STEM. The nanostructures of the catalyst and the W surface density have been correlated with paracetamol reaction studies. The results demonstrate the nature of active sites and high activity of the tungstated zirconia nanocatalyst, which is an environmentally clean alternative to the current homogeneous process.

  16. Substrate-HTcS thin film interaction studies by (S)TEM

    NARCIS (Netherlands)

    Ramaekers, P.P.J.; Klepper, D.; Kitazawa, K.; Ishiguro, T.

    1989-01-01

    This paper concerns with compatibility aspects beween HTcS thin film either their substrates. The influence of substrate-thin film interaction and thin film microstructure on the superconducting properties is discussed. In this respect, data based on (S)TEM observations are presented. It is

  17. Comparison between measured and predicted turbulence frequency spectra in ITG and TEM regimes

    NARCIS (Netherlands)

    Citrin, J.; Arnichand, H.; Bernardo, J.; Bourdelle, C.; Garbet, X.; Jenko, F.; Hacquin, S.; Puschel, M. J.; Sabot, R.

    2017-01-01

    The observation of distinct peaks in tokamak core reflectometry measurements—named quasi-coherent-modes (QCMs)—are identified as a signature of trapped-electron-mode (TEM) turbulence (Arnichand et al 2016 Plasma Phys. Control. Fusion 58 014037). This phenomenon is investigated with detailed linear

  18. Preparation of hard-to-make TEM samples using the FIB microscope; Praeparation von kompliziert herstellbaren TEM-Proben mit dem FIB-Mikroskop

    Energy Technology Data Exchange (ETDEWEB)

    Volkert, C.A. [Forschungszentrum Karlsruhe, Karlsruhe (Germany); Heiland, B.; Kauffmann, F. [Max-Planck-Inst. fuer Metallforschung, Stuttgart (Germany)

    2003-04-01

    The focused ion beam (FIB) microscope has become an important tool for the preparation of TEM samples over the last few years. Preparation of samples with the FIB has some specific advantages over conventional preparation methods which make it possible to prepare samples that would otherwise be difficult to prepare. The advantages that will be illustrated in this paper include: (1) precise selection of the sample volume to be prepared, (2) preparation of brittle materials, (3) preparation of highly stressed materials, and (4) preparation of composites composed of materials with widely differing properties. These advantages will be illustrated through several examples including cross-sectional preparation of nanocrystalline Ti-Si-N films, thermal barrier coatings, fatigued Al films, pecan shells, apatite, and metal whiskers. [German] Das Focused Ion Beam (FIB)-Mikroskop ist in den letzten Jahren zu einem wichtigen Werkzeug fuer die Praeparation von TEM-Proben geworden. Die Probenpraeparation mittels FIB hat gegenueber den konventionellen Praeparationsmethoden eine Reihe spezifischer Vorteile, die es ermoeglichen, Proben herzustellen, die ansonsten schwierig zu praeparieren waeren. Die in diesem Beitrag veranschaulichten Vorteile sind: (1) praezise Auswahl des zu praeparierenden Probenvolumens, (2) Praeparation von sproeden Materialien, (3) Praeparation von Materialien mit hohen Eigenspannungen, und (4) die Praeparation von Verbundwerkstoffen, die aus Komponenten mit stark unterschiedlichen Eigenschaften bestehen. Diese Vorteile werden anhand verschiedener Beispiele wie der Querschnittspraeparation von nanokristallinen Ti-Si-N-Schichten, thermischen Barriereschichten, Al-Schichten nach Ermuedung, Pekan-Nussschalen, Apatiten und Metallwhiskern veranschaulicht.

  19. Static shift correction of MT data in Tohoku district using TEM soundings; TEM ho data wo mochiita Tohoku chiho MT ho data no statistic shift hosei

    Energy Technology Data Exchange (ETDEWEB)

    Kawakami, N; Kumekawa, Y; Miura, Y; Takasugi, S [GERD Geothermal Energy Research and Development Co. Ltd., Tokyo (Japan); Fujinawa, Y [National Research Institute for Disaster Prevention, Tsukuba (Japan)

    1997-05-27

    There is a possibility that the wide-band MT observation data obtained in the central part of Tohoku district include the static shift effect. To grasp the static shift effect in the MT data, the TEM soundings were conducted at all the site where the MT data were measured. The TEM sounding system was developed for the shallow survey depth ranging from 5 m to 150 m. When showing the measured results on the histogram, it was found that the static shifts were concentrated in the vicinity of zero. About 70% of the data was below 0.2 decade. Only a slight static shift effect was observed. This means that the results obtained by the two-dimensional analysis are plausible. Especially, the static shift around plain was small. Therefore, the current results around the plain were trustful. On the other hand, the static shift in the mountainous area was rather large. Accordingly, the results around the mountainous area should be carefully treated. 7 refs., 10 figs.

  20. Fault detection by Turam TEM survey. Numerical model studies and a case history; TEM ho Turam sokutei haichi ni yoru danso kenshutsu no kokoromi. Model keisan to jisshirei

    Energy Technology Data Exchange (ETDEWEB)

    Wada, K; Tsutsui, T [Mitsui Mineral Development Engineering Co. Ltd., Tokyo (Japan); Ito, T [Chiba Univ., Chiba (Japan). Faculty of Science; Takeuchi, A [Toyama University, Toyama (Japan). Faculty of Science; He, P [Power Reactor and Nuclear fuel Development Corp., Tokyo (Japan)

    1997-05-27

    With an objective to detect faults estimated to exist along the Shigesumi valley in the Kamioka mine, discussions were given by using electromagnetic survey, which uses the Turam measurement arrangement based on the TEM method, and three-dimensional model calculations. The Turam measurement arrangement, which installs transmission loop fixedly, is used to identify nature and distribution of electrically conductive objects upon noticing abnormal portions in magnetic fields in the measurement data. In the model calculation, the plate model calculation method and the FDTD method were used, and so was the calculation code TEM3DL. The result revealed that strong topographical influence is seen from steep V-shaped valley existing along the traverse line in the measurement data, but an abnormal resistivity band accompanying remarkable distortion in the curve was detected. According to the result of the model calculation, anomaly detection may be found difficult in locations where a low resistivity band has not grown enough locally. It was possible from these facts to assume a model in which the low resistivity band exists directly below the Shigesumi valley, suggesting existence of faults. 2 refs., 8 figs.