Identification of Fragile Microscopic Structures during Mineral Transformations in Wet Supercritical CO2

AbstractThis study examines the nature of highly fragile reaction products that form in low water content supercritical carbon dioxide (scCO2) using a combination of focus ion beam/scanning electron microscopy, confocal Raman spectroscopy, helium ion microscopy (HeIM), and transmission electron microscopy (TEM). HeIM images show these precipitates are fragile rosettes. Using the TEM revealed details on the interfacial structure between the newly formed surface precipitates and the underlying initial solid phases. Detailed microscopy analysis revealed that growth of the precipitates either followed a tip growth mechanism, with precipitates forming directly on the forsterite surface if the initial solid was nonporous (natural forsterite) or growth from the surface of the precipitates, where fluid was conducted through the porous (nanoforsterite) agglomerates to the growth center. Identification of the mechanism of formation of hydrated/hydroxylated magnesium carbonate compound phases is a key factor in unraveling the impact of water recycling on mineral reactivity in low water content scCO2 solutions, which has received a great deal of attention as a result of the potential for CO2 to act as an atmospheric greenhouse gas. Techniques used here to examine these fragile structures are also used to examine a wide range of fragile material surfaces.

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Electron microscopy study of interfacial structure and reaction of Yba2Cu3O7/Y-ZrO2 films on LaAlO3 substrates

Journal of Materials Research ◽

10.1557/jmr.1998.0206 ◽

1998 ◽

Vol 13 (6) ◽

pp. 1485-1491 ◽

Cited By ~ 3

Author(s):

J. Y. Dai ◽

F. H. Kaatz ◽

P. R. Markworth ◽

D. B. Buchholz ◽

X. Liu ◽

...

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Interfacial Reaction ◽

Chemical Vapor ◽

Atomic Layer ◽

High Resolution Electron Microscopy ◽

Microscopy Study ◽

Interfacial Structure ◽

Reaction Products ◽

Transmission Electron

The detailed structure and interfacial reaction of epitaxial Yba2Cu3O7/Y-ZrO2 (YBCO/YSZ) films grown by chemical vapor deposition (CVD) on LaAlO3 (LAO) substrates are investigated by means of high-resolution electron microscopy (HREM), analytical transmission electron microscopy, and scanning transmission electron microscopy (STEM). The epitaxial relations of YBCO/YSZ/LAO are [100]YBCO // [110]YSZ // [100]LAO and (001)YBCO // (001)YSZ // (001)LAO. The optimum atomic configuration at the YSZ/LAO interface, in which oxygen is the first atomic layer on LAO, is proposed by using HREM combined with image simulation based on the atomic structure models of the interface. Near the YBCO/YSZ interface, two localized interfacial reaction products are formed: (i) a Y-rich modulated ZrO2 structure at the surface of the YSZ film, which may be caused by the diffusion of Y into the YSZ grains; (ii) an intergranular BaZrO3 phase formed by the diffusion of Ba along the columnar grain boundaries of the YSZ film during YBCO growth.

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Sample Preparation Methodologies for In Situ Liquid and Gaseous Cell Analytical Transmission Electron Microscopy of Electropolished Specimens

Microscopy and Microanalysis ◽

10.1017/s1431927616011855 ◽

2016 ◽

Vol 22 (6) ◽

pp. 1350-1359 ◽

Cited By ~ 9

Author(s):

Xiang Li Zhong ◽

Sibylle Schilling ◽

Nestor J. Zaluzec ◽

M. Grace Burke

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Focused Ion Beam ◽

General Procedure ◽

Ion Beam ◽

Metals And Alloys ◽

Stainless Steel Sample ◽

Transmission Electron ◽

Wide Range

AbstractIn recent years, an increasing number of studies utilizing in situ liquid and/or gaseous cell scanning/transmission electron microscopy (S/TEM) have been reported. Because of the difficulty in the preparation of suitable specimens, these environmental S/TEM studies have been generally limited to studies of nanoscale structured materials such as nanoparticles, nanowires, or sputtered thin films. In this paper, we present two methodologies which have been developed to facilitate the preparation of electron-transparent samples from conventional bulk metals and alloys for in situ liquid/gaseous cell S/TEM experiments. These methods take advantage of combining sequential electrochemical jet polishing followed by focused ion beam extraction techniques to create large electron-transparent areas for site-specific observation. As an example, we illustrate the application of this methodology for the preparation of in situ specimens from a cold-rolled Type 304 austenitic stainless steel sample, which was subsequently examined in both 1 atm of air as well as fully immersed in a H2O environment in the S/TEM followed by hyperspectral imaging. These preparation techniques can be successfully applied as a general procedure for a wide range of metals and alloys, and are suitable for a variety of in situ analytical S/TEM studies in both aqueous and gaseous environments.

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Production of Adenosine by Ectonucleotidases: A Key Factor in Tumor Immunoescape

Journal of Biomedicine and Biotechnology ◽

10.1155/2012/473712 ◽

2012 ◽

Vol 2012 ◽

pp. 1-9 ◽

Cited By ~ 47

Author(s):

François Ghiringhelli ◽

Mélanie Bruchard ◽

Fanny Chalmin ◽

Cédric Rébé

Keyword(s):

Immune Response ◽

Cancer Cells ◽

Tumor Cells ◽

Stromal Cells ◽

T Cell Response ◽

Antitumor Immune Response ◽

Tumor Bed ◽

Wide Range ◽

Key Factor ◽

The Impact

It is now well known that tumor immunosurveillance contributes to the control of cancer growth. Many mechanisms can be used by cancer cells to avoid the antitumor immune response. One such mechanism relies on the capacity of cancer cells or more generally of the tumor microenvironment to generate adenosine, a major molecule involved in antitumor T cell response suppression. Adenosine is generated by the dephosphorylation of extracellular ATP released by dying tumor cells. The conversion of ATP into adenosine is mediated by ectonucleotidase molecules, namely, CD73 and CD39. These molecules are frequently expressed in the tumor bed by a wide range of cells including tumor cells, regulatory T cells, Th17 cells, myeloid cells, and stromal cells. Recent evidence suggests that targeting adenosine by inhibiting ectonucleotidases may restore the resident antitumor immune response or enhance the efficacy of antitumor therapies. This paper will underline the impact of adenosine and ectonucleotidases on the antitumor response.

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Identifying long-range synaptic inputs using genetically encoded labels and volume electron microscopy

10.1101/2021.12.13.472405 ◽

2021 ◽

Author(s):

Irene Pilar Ayuso Jimeno ◽

Paolo Ronchi ◽

Tianzi Wang ◽

Catherine Gallori ◽

Cornelius Thilo Gross

Keyword(s):

Electron Microscopy ◽

Long Range ◽

Focused Ion Beam ◽

Ion Beam ◽

Anterior Cingulate ◽

Specific Cell ◽

Reaction Products ◽

Synaptic Inputs ◽

Surfactant Treatment ◽

Volume Em

Enzymes that facilitate the local deposition of electron dense reaction products have been widely used as labels in electron microscopy (EM). Peroxidases, in particular, can efficiently metabolize 3,3′-diaminobenzidine tetrahydrochloride hydrate (DAB) to produce precipitates with high contrast under EM following heavy metal staining, and can be genetically encoded to facilitate the labeling of specific cell-types or organelles. Nevertheless, the peroxidase/DAB method has so far not been reported to work in combination with 3D volume EM techniques (e.g. Serial blockface electron microscopy, SBEM; Focused ion beam electron microscopy, FIBSEM) because the surfactant treatment needed for efficient reagent penetration disrupts tissue ultrastructure and because these methods require the deposition of large amounts of heavy metals that can obscure DAB precipitates. However, a recently described peroxidase with enhanced enzymatic activity (dAPEX2) appears to successfully deposit EM-visible DAB products in thick tissue without surfactant treatment. Here we demonstrate that multiplexed dAPEX2/DAB tagging is compatible with both FIBSEM and SBEM volume EM approaches and use them to map long-range genetically identified synaptic inputs from the anterior cingulate cortex to the periaqueductal gray in the mouse brain.

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Evaluation of Phytotoxicity of Bimetallic Ag/Au Nanoparticles Synthesized Using Geum urbanum L.

Journal of Inorganic and Organometallic Polymers and Materials ◽

10.1007/s10904-020-01814-0 ◽

2020 ◽

Author(s):

Marcin Szymanski ◽

Renata Dobrucka

Keyword(s):

Electron Microscopy ◽

Metal Nanoparticles ◽

Au Nanoparticles ◽

Lepidium Sativum ◽

Natural Ecosystems ◽

Wide Range ◽

Microscopic Studies ◽

Living Organisms ◽

The Impact ◽

Geum Urbanum

AbstractThe growing production and wider application of metal nanoparticles gives rise to many concerns about their release to natural ecosystems. It is very important to be aware of the harmful impact of nanoparticles on living organisms, including plants. Therefore, it is of vital significance to explore the impact of metal nanoparticles on plants. This work assessed the phytotoxicity of bimetallic Ag/Au nanoparticles and Geum urbanum L. extract. The obtained bimetallic Ag/Au nanoparticles were characterized by UV–vis spectrophotometry (UV–vis), Transmission electron microscopy (TEM), Scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). The microscopic studies enabled the determination of the size of the obtained nanoparticles, which was 50 nm. The wide range of concentrations evaluated in the course of the study made it possible to observe changes in selected plants (seeds of Lepidium sativum, Linum flavum, Zea mays, Solanum lycopersicum var. Cerasiforme and Salvia hispanica-Chia) caused by a stress factor. The studies showed that the solution of Ag/Au nanoparticles was most toxic to flax (IC50 = 9.83 × 10–6/9.25 × 10–6 mg/ml), and least toxic to lupine (IC50 = 1.23 × 10–3/1.16 × 10–3 mg/ml). Moreover, we studied the toxicity of Geum urbanum extract. The extracts diluted to 0.00875 mg/ml stimulated the growth of lupine, flax and garden cress; extracts diluted to 0.175 mg/ml stimulated the growth of Chia and tomatoes; and extracts diluted to 0.00875 mg/ml stimulated the growth of corn. G. urbanum extract was most toxic to lupine (IC50 = 0.374 mg/ml), and least toxic to corn (IC50 = 4.635 mg/ml).

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Microstructural Characterization of Photoluminescent Porous Silicon

MRS Proceedings ◽

10.1557/proc-256-47 ◽

1991 ◽

Vol 256 ◽

Cited By ~ 10

Author(s):

J. M. Macaulay ◽

F. M. Ross ◽

P. C. Searson ◽

S. K. Sputz ◽

R. People ◽

...

Keyword(s):

Electron Microscopy ◽

Optical Properties ◽

Porous Silicon ◽

Microstructural Characterization ◽

Photoluminescence Spectroscopy ◽

Experimental Results ◽

Visible Luminescence ◽

Wide Range ◽

The Impact

ABSTRACTWe have used electron microscopy to examine the microstructure of porous silicon films over a wide range of doping levels, and photoluminescence spectroscopy to study their optical properties. We discuss the impact of our experimental results on models from the literature which were proposed to explain visible luminescence from porous silicon.

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Synergistic radar and radiometer retrievals of ice hydrometeors

Atmospheric Measurement Techniques ◽

10.5194/amt-13-4219-2020 ◽

2020 ◽

Vol 13 (8) ◽

pp. 4219-4245

Author(s):

Simon Pfreundschuh ◽

Patrick Eriksson ◽

Stefan A. Buehler ◽

Manfred Brath ◽

David Duncan ◽

...

Keyword(s):

Water Content ◽

Information Content ◽

Cloud Model ◽

Cloud Microphysics ◽

Retrieval Algorithm ◽

Particle Model ◽

Microphysical Properties ◽

Millimeter Wavelengths ◽

Wide Range ◽

The Impact

Abstract. Remote sensing observations at sub-millimeter wavelengths provide higher sensitivity to small hydrometeors and low water content than observations at millimeter wavelengths, which are traditionally used to observe clouds and precipitation. They are employed increasingly in field campaigns to study cloud microphysics and will be integrated into the global meteorological observing system to measure the global distribution of ice in the atmosphere with the launch of the Ice Cloud Imager (ICI) radiometer on board the second generation of European operational meteorological satellites (Metop-SG). Observations at these novel wavelengths provide valuable information not only on their own but also in combination with complementary observations at other wavelengths. This study investigates the potential of combining passive sub-millimeter radiometer observations with a hypothetical W-band cloud radar for the retrieval of frozen hydrometeors. An idealized cloud model is used to investigate the information content of the combined observations and establish their capacity to constrain the microphysical properties of ice hydrometeors. A synergistic retrieval algorithm for airborne observations is proposed and applied to simulated observations from a cloud-resolving model. Results from the synergistic retrieval are compared to equivalent radar- and passive-only implementations in order to assess the benefits of the synergistic sensor configuration. The impact of the assumed ice particle shape on the retrieval results is assessed for all retrieval implementations. We find that the combined observations better constrain the microphysical properties of ice hydrometeors, which reduces uncertainties in retrieved ice water content and particle number concentrations for suitable choices of the ice particle model. Analysis of the retrieval information content shows that, although the radar contributes the largest part of the information in the combined retrieval, the radiometer observations provide complementary information over a wide range of atmospheric states. Furthermore, the combined observations yield slightly improved retrievals of liquid cloud water in mixed-phase clouds, pointing towards another potential application of combined radar–radiometer observations.

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OPERATING SPECIFICATIONS OF CATALYTIC CLEANING OF GAS FROM BIOMASS GASIFICATION

Acta Polytechnica ◽

10.14311/ap.2015.55.0401 ◽

2015 ◽

Vol 55 (6) ◽

pp. 401 ◽

Cited By ~ 3

Author(s):

Martin Lisý ◽

Marek Baláš ◽

Michal Špiláček ◽

Zdeněk Skála

Keyword(s):

Electrical Energy ◽

Magnesium Carbonate ◽

Theoretical Description ◽

Gas Cleaning ◽

Catalytic Destruction ◽

Key Factor ◽

Calcium Magnesium ◽

Waste Gasification ◽

Calcium Catalysts ◽

The Impact

The paper focuses on the theoretical description of the cleaning of syngas from biomass and waste gasification using catalytic methods, and on the verification of the theory through experiments. The main obstruction to using syngas from fluid gasification of organic matter is the presence of various high-boiling point hydrocarbons (i.e., tar) in the gas. The elimination of tar from the gas is a key factor in subsequent use of the gas in other technologies for cogeneration of electrical energy and heat. The application of a natural or artificial catalyst for catalytic destruction of tar is one of the methods of secondary elimination of tar from syngas. In our experiments, we used a natural catalyst (dolomite or calcium magnesium carbonate) from Horní Lánov with great mechanical and catalytic properties, suitable for our purposes. The advantages of natural catalysts in contrast to artificial catalysts include their availability, low purchase prices and higher resilience to the so-called catalyst poison. Natural calcium catalysts may also capture undesired compounds of sulphure and chlorine. Our paper presents a theoretical description and analysis of catalytic destruction of tar into combustible gas components, and of the impact of dolomite calcination on its efficiency. The efficiency of the technology is verified in laboratories. The facility used for verification was a 150 kW pilot gasification unit with a laboratory catalytic filter. The efficiency of tar elimination reached 99.5%, the tar concentration complied with limits for use of the gas in combustion engines, and the tar content reached approximately 35 mg/m<sub>n</sub><sup>3</sup>. The results of the measurements conducted in laboratories helped us design a pilot technology for catalytic gas cleaning.

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Hitachi High Technologies America, Inc.

Microscopy Today ◽

10.1017/s1551929514000273 ◽

2014 ◽

Vol 22 (S1) ◽

pp. 6-6 ◽

Cited By ~ 1

Keyword(s):

Electron Microscopy ◽

Focused Ion Beam ◽

Materials Science ◽

Ion Beam ◽

Biological Research ◽

Industrial Manufacturing ◽

Transmission Electron ◽

Wide Range ◽

High Technologies ◽

Scanning Electron

The Nanotechnology Systems Division (NSD) of Hitachi High Technologies America, Inc. (HTA) provides technologically advanced solutions to meet the diverse and complex challenges of materials science, biological research, and industrial manufacturing. We support our satisfied customers with a wide range of reliability-proven instrumentation, including scanning electron microscopy (SEM), analytical and biological transmission electron microscopy (TEM), dedicated STEM, focused ion beam (FIB), tabletop SEM, and microanalysis sample preparation systems.

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Site Specific TEM Specimen Preparation using an FIB/TEM System

Microscopy and Microanalysis ◽

10.1017/s1431927600035042 ◽

2000 ◽

Vol 6 (S2) ◽

pp. 510-511 ◽

Cited By ~ 3

Author(s):

T. Kamino ◽

T. Yaguchi ◽

T. Ohnishi ◽

K. Umemura ◽

S. Tomimatsu

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Focused Ion Beam ◽

Ion Beam ◽

Specimen Preparation ◽

Site Specific ◽

Specimen Holder ◽

Transmission Electron ◽

Wide Range ◽

Scanning Transmission

The focused ion beam(FIB) technique, developed for the microelectronics industry has become a major method for site specific transmission electron microscopy(TEM) specimen preparation in a wide range of materials[l]. The FIB lift-out technique has improved the specimen preparation procedures by removing complicated initial fabrication required prior to the FIB milling[2]. However, conventional FIB techniques are still having increased difficulty in meeting failure analysis needs from high technology industries such as microelectronics.We have developed a site specific TEM specimen preparation method using a combination of an FIB instrument and an intermediate voltage TEM equipped with a scanning attachment [3]. In this method, the specimen is mounted on an FIB-TEM compatible specimen holder, so that localization of the specific site can be carried out in the FIB and TEM using the same holder. The scanning electron imaging mode may be used to observe surface structures of the milled area, and the scanning transmission electron microscopy(STEM) mode may be used to observe structures inside of the milled surface.

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