bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification of Left-Handed RNA in the Cells of the Meridional Rows of the Normal Adult Mammalian Ocular Lens
Authors: Gagna CE , Kuo H-R , Turley J , Spencer J , Rescinti N , Lambert WC 
Published: July 2020

Abstract
The purpose of this research project was to characterize the distribution of left-handed Z-RNA sequences within the epithelial cells of the adult noncataractous crystalline dog lens: the meridional rows (MR). This was achieved by using anti-Z-RNA IgG polyclonal antibody probes. Both light microscopy (LM) and electron microscopy (EM) were used to analyze the tissue binding of the anti- Z-RNA antibodies. Nucleic acids can adopt many different helical conformations (1), such as Z-DNA (Fig. 1) and Z-RNA (2,3). The lens is made up of a single cell type, which is a monolayer of undifferentiated epithelial cells covering its anterior surface (Fig. 2). At the equator of the lens, these cells elongate and form concentric layers of the secondary (nucleated) fiber cells, which undergo cell death-terminal differentiation (denucleation). The epithelial monolayer consists of several cell types, each of which has unique characteristics.
The production of anti-Z-RNA polyclonal antibody probes was achieved using four
Designing, Building and Operating a Microcalorimeter Eds Outside a Cryogenic Research Facility
Authors: Howard J , Hammermeister D , McCarthy J 
Published: July 2020

Abstract
In 1999 Thermo NORAN completed licensing agreements with NIST for the microcalorimeter x-ray spectrometer technology developed by Martinis, Irwin, Hilton and Wollman.Steady progress has been made to commercialize this technology.
Briefly, the NIST microcalorimeter consists of a Transition Edge Sensor (TES) which measures the temperature rise in an absorber due to an incident photon. The sensor must be operated at temperatures below 100 milliKelvin, which is provided by an Adiabatic Demagnetization Refrigerator (ADR), coupled with a traditional liquid helium cryostat. Additional enabling technology includes a Superconducting Quantum Interference Device (SQUID) and a SQUID Array for device readout and low temperature signal amplification. All of this technology has been widely used in cryogenic research facilities for many years, but is not readily available for commercial purchase and use.
Initial work focused on adapting the NIST design to a modern FESEM. The available ports in an FESEM required scaling the heat shields, and cold extension diameters by 68%.
Progress Towards Arrays of Microcalorimeter X-Ray Detectors
Authors: Nam SW , Wollman DA , E. Newbury Dale , Hilton GC , Irwin KD , Rudman DA , S.Deiker  , Bergren NF , M. Martinis John 
Published: July 2020

Abstract
The high performance of single-pixel microcalorimeter EDS (μ,cal EDS) has been shown to be very useful for a variety of microanalysis cases. The primary advantage of jxcal EDS over conventional EDS is the factor of 25 improvement in energy resolution (∽3 eV in real-time). This level of energy resolution is particularly important for applications such as nanoscale contaminant analysis where it is necessary to resolve peak overlaps at low x-ray energies. Because μcal EDS offers practical solutions to many microanalysis problems, several companies are proceeding with commercialization of single-pixel μal EDS technology. Two drawbacks limiting the application of uxal EDS are its low count rate (∽500 s−1) and small area (∽0.04 mm for a bare single pixel, ∽5 mm2 with a polycapillary optic). We are developing a 32x32 pixel array with a total area of 40 mm2 and with a total count rate between 105 s−1 and 106 s−1.
A New Methodology for Element Imaging in the Scanning Electron Microscope
Authors: Smith Paul , Gannon John , Eggert Frank 
Published: July 2020

Abstract
The analysis of samples with a scanning electron microscope often requires element distribution images. Until recently, element mapping was strongly limited by the count rate that could be processed with conventional EDS systems using Si(Li) or Ge crystal diode detectors. The enhancement of secondary and backscattered SEM images can now be achieved through the addition of rapid color imaging. Using a new methodology for color enhancement, features as small as 1 micrometer can be colored and easily distinguished. The addition of color to SEM images enables easy visualization of element distributions and allows the microstructural features and compositional variations of different materials to be more readily identified. Persons unfamiliar with electron microscopy can more readily interpret color images than black and white or gray scale images. This new technology for imaging elements has great potential to revolutionize electron microscopy.
The detector technology behind this new methodology is the silicon drift diode (SDD).
A Microcalorimeter for High Resolution EDS Microanalysis in Low Voltage SEM Applications
Authors: Redfern Del , Nicolosi Joe , Hess Uwe , Höhne Jens 
Published: July 2020

Abstract
As scientists look to determine elemental composition of smaller and smaller particles using a scanning electron microscope, the usefulness of conventional EDS detectors (Si(Li)) becomes limited. to obtain analytical information from the SEM on extremely small particles the analyst can reduce the excitation energy of the electron beam; excitation energies of around 3kV are regularly used for the analysis of these particles. with only low energies (up 3keV) to work with, the scientists have to use L, or in some cases M, spectra to determine the chemical composition of the particle. A standard Si (Li) with a resolution of ≈100eV @3keV (130eV at 6keV) will be unable to adequately resolve spectra for confident characterization work to be carried out for these low energy lines. A new generation of EDS detectors for microanalysis is required to fulfill the scientists requirements for fast, simultaneous chemical determination of these small particles.
Catalyst Characterization with the Hitachi Hd-2000 STEM
Authors: Blom DA , Allard LF , Gates BC , Park PW 
Published: July 2020

Abstract
New EPA regulations limiting the emissions of NOx from diesel engines will require a reduction by 70% in the amount of NOx leaving the tailpipe of diesel powered vehicles by the year 2004. Some form of exhaust aftertreatment will need to be applied to diesel engines to meet the new stricter requirements. One option is to develop a “lean-NOx” catalyst that uses a hydrocarbon reductant (e.g. diesel fuel) to convert NOx into N2 and O2. Two of many constraints on such a catalyst are that it achieve a high degree of conversion over a fairly broad temperature range and that the amount of reductant necessary to reach the 70% goal is sufficiently small as to be cost effective. A number of promising systems comprise either platinum group metals or base metals on oxide supports. Such catalyst systems typically involve near-atomic dispersions, or ultra-fine clusters, of the heavy metal species on the oxide support.
Electron Energy Loss Spectroscopy Study of ZSM-5 Zeolite and MCM-41 Mesoporous Materials
Authors: Paraguay D F , Miki-Yoshida M , Espinosa-Magaña F , Terrés E , Dominguez JM 
Published: July 2020

Abstract
Zeolites are crystalline aluminosilicates possessing a regular microporous channel network. Unique properties of zeolites such as the presence of framework cations, acid sites, and their well-defined porous structure-with pore sizes similar to those of small molecules-account for their traditional utilization in ion exchange, catalysis, and separation. in addition, zeolites are being investigated for novel emerging applications in a diversity of areas including optoelectronic devices and reactive membranes because they provide for discrimination, recognition, and organization of molecules with a precision of less 1 Å. However, their applications are limited by the relatively small pore openings; therefore, pore enlargement was one of the main aspects in zeolite chemistry. A new class of porous materials, which contain large uniform spaces in the mesopore size regimen (15-100 Å), was reported. These so-called mesoporous materials have two different characters, disorder at the atomic scale but long range order at the atomic scale but long range order at the mesoscopic scale.
Sintering of Pd Automotive Catalysts
Authors: Xu Q , Kharas KCC , Datye AK 
Published: July 2020

Abstract
The focus of this work is on processes that lead to loss of active metal surface area during high temperature operation of automotive catalysts. As under-floor catalytic converters are moved closer to the engine to achieve faster light off, the catalyst is subjected to higher operating temperatures during the normal driving cycle. Sintering of the active metal phase leading to loss of surface area represents one of the most important factors limiting the long-term durability of automotive catalysts. Despite its obvious technological importance, fundamental understanding of sintering is still lacking.
In this research, we have prepared a series of Pd metal catalysts on a θ alumina support. The metal loading was varied from 1.1 wt% to 7 wt%. The catalysts were subjected to sintering at 900 °C for up to 192 hours. To ensure relevance to automotive catalysts, the sintering was performed in a gas atmosphere that contained 10 mol % H2O in flowing N2 or in air.
Characterization of Antimony-Doped TIN Oxide Catalysts
Authors: Sun K , Liu J , Browning ND 
Published: July 2020

Abstract
Antimony-doped tin oxide (ATO) catalysts are used for the oxidation of propylene to acrolein, the ammoxidation of propylene to acrylonitrile and the oxidative dehydrogenation of butanes to 1,3- butadiene. The distribution and valence states of Sb in ATOs are key in determining their catalytic activities. While these materials have been subjects of intensive studies for more than 20 years, X-ray photoelectron spectroscopy, Mössbauer spectrometry, and X-ray absorption spectroscopy4 have so far provided only indirect data for the distribution of Sb and its valence states. in particular, while has been hypothesized that the tin (IV) oxide contains Sb (V) within the bulk lattice and Sb (III) located at surface sites, no direct experimental evidence for this has been provided.
Here we use electron energy loss spectroscopy (EELS) combined with Z-contrast imaging in a JEOL 2010F field emission STEM/TEM operating at 200 KV to analyze ATO catalysts.
Structure Changes in Transition Metal Oxides Induced During Electron Microscopy
Authors: Su DS , Zeitler E , Schlögl R 
Published: July 2020

Abstract
Many catalytic materials, especially the maximum valence transition metal oxides, are particularly susceptible to electron beam irradiation and thus undergo structural changes. Hence knowledge about the behaviour of catalytic materials under the electron beam is of importance for all TEM investigations of such materials. On the other hand, this effect can be utilised for an in-situ study of the reductive property, phase transition and/or phase stability of various transition metal oxides in an inert, simple ambient high-vacuum. The knowledge so obtained is needed for understanding the reduction mechanism of catalysts in more complicated chemical environments. in the present work, we study the electron beam induced change in MoO3 and TiO2 (anatase) by means of electron energy-loss spectroscopy (EELS), electron diffraction and high-resolution electron microscopy (HREM).
Molybdenum trioxide, MoO3, important as catalyst in the selective oxidation of hydrocarbons, forms an orthorhombic crystal layer structure. Fig. 1 shows oxygen AT-edges recorded at various irradiation periods in a Philips 200 FEG electron microscope.
Characterizing Industrial Catalysts: Challenges and Opportunities
Authors: Liu Jingyue 
Published: July 2020

Abstract
Industrial catalysts are often chemically and physically complex systems resulting from many years of technology, science, and art. Successful development of commercial catalysts requires talents of many disciplines including chemistry, chemical engineering, surface science, materials science, and physics. A better understanding of the relationship between catalyst structure and activity can provide a scientific prediction of catalytic properties. The insight gained from catalyst characterization can provide guidance for designing and synthesizing better commercial catalysts. Characterization of industrial catalysts is challenging and expensive; however, it can be highly rewarding in developing commercial catalysts used for manufacturing multibillion-dollar products.
The ultimate goal of catalyst characterization is to correlate the physical, chemical, mechanical, and electronic properties of a catalyst to its activity, selectivity, and stability. in industrial practice, however, because of the complexity of the catalysts, the time limit, and the available resources, the goal of characterizing industrial catalysts is often to elucidate the key performance indicators of a catalyst; these key performance indicators, such as the size and spatial distribution and the composition of the active components and promoters, can then be used to provide guidance for manufacturing better catalysts with desired properties.
Structural Insights of Supported Nanoparticles By Z-Contrast and High Resolution Electron Microscopy
Authors: Yang Judith C , Devlin Erin , Rhodes William , Bradley Steven 
Published: July 2020

Abstract
A vital component to nanoparticle science will be the three dimensional (3-D) characterization of both structure and chemistry of these nanoparticles on their supports at the nanometer scale and below. to achieve this goal, quantitative Z-contrast and atomic resolution will provide essential information about their structure. Z-contrast imaging is ideal for imaging these large Z nanoparticles on low Z supports. in this proceedings, we present a quantitative Z-contrast method to determine number of atoms and a few examples of a combination of electron microscopy methods to gain structural insights into supported nanoparticle, such as Pt on different support materials, PtRu5 on C and Pt-Sn on SiO2.
A relatively new and powerful method is to determine the number of atoms in a nanoparticle, by very high angle annular dark-field (HAADF) imaging or Z-contrast technique [1, 2]. We have shown that quantification of the absolute image intensity from very HAADF microscopy will provide the number of atoms in very small particles of high atomic number to ±2 atoms for Re6 nanoparticles supported on carbon [3].
Nanoscale Imaging of Topotactic Redox Reactions of Antimony Single Crystals
Authors: Germinario Louis T 
Published: July 2020

Abstract
Antimony compounds play a major role in commercial polyester catalysis. Antimony complexes are used in ppm quantities, not only to catalyze melt-phase reactions in which oligomers are converted to high molecular weight polymers, such as poly(ethyleneterephthalate) (PET), but to further increase chain length through a high temperature solidphase polymerization process. During the course of the melt-phase reaction the initial, clear and colorless, Sb+3 compounds are transformed to a gray product that has been linked with the reduction of Sb+3 complexes to metallic antimony (Sb°). The presence of oxygen during the solid-phase process also increases clarity and reduces color of gray polymers. to further our understanding of antimony catalysis, a field emission-based scanning electron microscope (FEGSEM) was used to study antimony transformations during melt-phase polymerization and after treatments at high temperature in oxidizing and reducing environments.
Antimony metal powder from Fisher Scientific was used in redox studies.
Nanoscale Structural and Chemical Segregation in Pt50Ru50 Electrocatalysts
Authors: Stroud Rhonda M , Long Jeffrey W , Swider-Lyons Karen E , Rolison Debra R 
Published: July 2020

Abstract
To address how the chemical and structural heterogeneity of Pt50Ru50 nanoparticles affects methanol oxidation activity, we have employed an arsenal of transmission electron microscopy techniques (conventional bright field-imaging, selected area diffraction, atomic-resolution lattice imaging, electron-energy loss spectroscopy, and energy-dispersive x-ray spectroscopy) to characterize 2.5-nm particles in differing oxidation and hydration states. Our studies demonstrate that electrocatalysts containing a high fraction of Ru-rich hydrous oxide, as apposed to the anhydrous PtRu bimetallic alloy, have as much as 250x higher methanol oxidation activity
The nominally 2.5-nm Pt50Ru50 particles were studied in as-received, reduced and reoxidized forms. The reducing treatment consisted of 2 h at 100 °C in flowing 10% PL/argon mixture. For re-oxidation, the reduced particles were heated for 20 h at 100 °C in an H2O-saturated oxygen atmosphere. The particles were suspended in methanol, and pipetted onto holey-carboncoated Cu grids for TEM studies.
Scanning Electron Microscopic Analysis on the Deformation Mechanisms in NACRE
Authors: Wang RZ , Suo Z , Evans AG , Yao N , Aksay IA 
Published: July 2020

Abstract
Princeton Materials Institute, Princeton University, Princeton, New Jersey 08544 Some biological materials exhibit structural robustness, despite the brittle nature of their constituents.Nacre (mother-of-pearl), the pearly internal layer of many mollusc shells, is addressed in this study. This material comprises about 95% aragonite tablets (a mineral form of CaC03), The polygonal tablets were glued with only a few percent of biological macromolecules into layered structure. The goal of the present study is to elucidate the basic inelastic deformation mechanisms.
Typical stress /strain curves in tension and compression are plotted in Fig. 1. All tensile curves exhibited extensive inelastic deformation. After testing, the samples were initially examined using a stereo microscope (Leica MZ8) and a metallurgical microscope (Leica MEF4M) followed by analysis of the structural details using scanning electron microscopy (Philip XL-30). Optical imaging provided a visualization of the inelastic zone, manifest as white tension lines.
TEM Studies of Shear Bands in a Bulk Metallic Glass Based Composite
Authors: Pekarskaya E , Kim CP , Johnson WL 
Published: July 2020

Abstract
In 1980’s the discovery of multicomponent systems with exceptional glass forming ability enabled the synthesis of metallic glasses at relatively low cooling rates, 10−1 — 102 K/s and at a larger thicknesses. Bulk metallic glasses normally have very high yield stress, σy = 0.02 · Y (Y is Young’s modulus), high elastic limit of about 2%, but fail with very little global plasticity, typically along a localized shear band at a 45 degree angle with respect to the applied stress.
The material studied in the present work is a two-phase Zr56.3Ti13.8Cu6.9Ni5.6Nb5.0Be12.5 alloy,prepared by in-situ processing. The alloy consists of amorphous and crystalline phases. In-situ TEM straining (tensile) experiments were performed at room temperature in JEOL 4000EX operating at 300kV. The experiments were carried out in the Center for Microanalysis of Materials in the University of Illinois at Urbana-Champaign. The goal of the study was to understand the deformation mechanisms of such composite material.
Scanning Electron Microscopy Investigation of Deformation in the Vicinity of a Mode II Crack Tip in Unidirectional Toughened Epoxy Composites
Authors: Iarve EV , Ragland W 
Published: July 2020

Abstract
Delamination related research in fiber-reinforced composites has attracted considerable interest due to its significant practical importance. Significant difference in deformation patterns in the crack tip vicinity were observed for Mode I and Mode II delaminations and reported by several authors including [1-3]. A sequence of 45° (with respect to the crack plane) microcracks is believed to form beyond the Mode II crack tip in polymer composites. The propagation of a Mode II crack is believed to be a result of rupture and coalescence of these tension microcracks.
A Philips XL30 ESEM scanning electron microscope was used for testing. A three-point bend stage was designed to perform in situ end notch flexure tests on a pre-cracked miniature (1.4” long and 0.25” wide) 24-ply unidirectional specimen. The material system utilized in the experiment was a toughened carbon epoxy unidirectional composite, IM7/977-3. The miniature specimen was cut out of a standard size (8” long, 1” wide) specimen after a shear crack formed in the course of ENF testing.
Microstructures in Pressureless Sintered AIN-SiC Ceramics
Authors: Yu YD , Tangen I-L , Einarsrud M-A , Høier R , Grande T , Solberg JK 
Published: July 2020

Abstract
Aluminum nitride (AlN) is known to have a high thermal conductivity and is one of the valid candidates as substrate material for integrated circuits. The material also has a potential in metal production and handling. However, AlN has only a moderate flexural strength and fracture toughness. It has been reported that SiCA1N composites (SiC/AIN ratio ≥ 50%) can be manufactured by means of pressureless sintering. Furthermore, it is possible to fabricate self-reinforced SiC-based materials with whisker-like crystals in composite ceramics by choosing appropriate sintering additive and condition. in the present study, we investigated the possibility to prepare in-situ formed SiC-whisker reinforced AlN-materials and studied the microstructure of the composite.
An AlN-SiC composite ceramic sample (20 vol% SiC) was prepared for the investigation. The AlN-SiC composite was processed from a mixture of the starting powders with 2.5 wt% Al2O3-Y2O3 as a sintering additive.
Compositional Mapping with Energy Filtering TEM: The Present Status
Authors: Hofer Ferdinand , Kothleitner Gerald , Warbichler Peter 
Published: July 2020

Abstract
Energy filtering transmission electron microscopy (EFTEM) has matured into an important nanoanalytical technique in both materials and life sciences. One of the technique′s main advantages stems from the possibility to quickly form images that contain two-dimensional elemental information for most elements (Li to Pu) from relatively large specimen areas with nanometer resolution. Over the last years numerous and wide-ranging applications have demonstrated its almost unrivalled power for assessing typical materials science questions.
Both in-column or post-column filter microscopes have reached a high performance level, but future improvements are still desirable, in particular with respect to increased transmissivity, improved isochromaticity and higher detection efficiency. Current instruments allow to acquire elemental maps with 1-5 nm spatial resolution limited mainly by the aberrations of the microscope and by the quality of the specimen. As recently shown 0.4 nm resolution is feasible.
One major practical problem of EFTEM compositional mapping is the poor signal-to-noise ratio, which means that experimental parameters have to be chosen very carefully in order to optimize this ratio.