bluuebunny/crossref_metadata_2025_split huggingface dataset:
Orientation Relationships in the System Nb-NbCr2
Authors: Kotula P G , Chen K C , Thoma D J , Chu F , Mitchell T E 
Published: July 2020

Abstract
Laves-phase intermetallics are of potential use as high-temperature structural materials. NbCr2-based C15-structured alloys are of particular interest for such applications. by themselves, Laves phases generally have poor ductility and fracture toughness at low temperatures. Two phase alloys (i.e., Laves phase and the ductile bcc phase) are considered more promising for structural applications. The orientation relationships between the two phases can contribute to the mechanical behavior of the material. In this study, observations of two different orientation relationships in a Nb-NbCr2 eutectic are discussed and compared with previous studies of the NbCr2 system, as well as the TiCr2 system.
A Nb-NbCr2 eutectic alloy was prepared by arc-melting high-purity alloys followed by annealing at 1400°C for 100 h and then cooling at l°C/min. The complete details of the materials preparation have been given elsewhere. Specimens were prepared for observation in the transmission electron microscope (TEM) by cutting 3 mm discs with a coring saw, followed by dimpling and ion milling. Microstructural characterization was performed with a Philips CM30 TEM operating at 300 kV.
Charge Density Wave Modulated Structures in the Intercalated Tunnel Phases AyNb3X4 (A = In, Tl; X = Se, Te; 0 &lt; y &lt; 1)
Authors: Bennett JC , Boswell FW 
Published: July 2020

Abstract
Although the unusual microstructural and electronic properties of charge density wave (CDW) modulated compounds have been extensively investigated over the past two decades, many aspects of the complex behaviour of these systems remain unexplained. As a result, the characterization of a new family of CDW structures, in which the CDW properties can be widely varied in a predictable manner, is of experimental and theoretical interest.
The Nb3X4 (X = S, Se, Te) family of compounds is based on a hexagonal unit cell built up of edge and face sharing NbX6 octahedra (Figure 1). The structure is characterized by zigzag Nb-Nb chains and large hexagonal tunnels running parallel to the c-axis. One member of this family, Nb3Te4, is known to undergo a CDW phase transition at ∼100 K. A large number of metal atoms can be introduced into the tunnels to form a family of isostructural, intercalated compounds AyNb3X4. Electrical resistivity measurements on polycrystalline pellets of InyNb3X4 (X = Se, Te) have revealed temperature anomalies indicative of the formation of CDW in these materials.
A Micro Analytical Study of Interfacial Reaction Between Lead-Tin Solders and Palladium
Authors: Ghosh G 
Published: July 2020

Abstract
Palladium is widely used for metallization of electronic circuits and in electronic packaging. During soldering palladium dissolves in the liquid solder and form various intermetallics both at the solder/substrate interface and in the solder. Diffusion of atomic species lead to the formation of intermetallics in the solid state as well. As the dissolution and interfacial reaction continue, the solder comes in contact with other metallization layer(s) and eventually with copper. This leads to a very complex microstructural evolution process which ultimately affects the interfacial mechanics and transport properties. In order to improve the reliability of electronic packaging, it is necessary to understand and control the dissolution and solid-state reaction mechanisms between the metallization layers and currently used lead-tin solders. As a first step towards modelling and understanding this complex microstructural evolution, here we have undertaken a systematic study of interfacial reaction between lead-tin solders and palladium.
Pure Sn, Sn-38 mass% Pb and Pb-5 mass% Sn were used in this study.
Characterization of WC-VC-Co Cemented Carbides Using Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray Spectroscopy (EDS)
Authors: Arenas F , de Arenas I B , Ochoa J , - Cho S A 
Published: July 2020

Abstract
The two important constituents of metallic tool alloys are transition metal carbides and metals of the iron group, Fe, Ni, Co. Combining them, based on WC, it is obtained a hard and tough cutting tool material. Many attempts have been made to develop alternative cemented carbide systems by substituting a portion of WC by other hard phases. In this investigation, microstructure and phases composition of 90 mass% [ (1-y) WC - y VC ] - 10 mass% Co with y = 0, 0.2, 0.4, 0.6 and 1.0 sintered cemented carbides were studied by Backscattering electron (BSE) compositional images, elemental dot maps and X - ray microanalysis. These techniques have allowed to determine the different phases present, their morphology and composition.
Cylindrical samples of 10 mm. in diameter and height were manufactured by vacuum sintering at 1400°C of uniaxially pressed compacts at 350 MPa. Liquid phase sintering is the predominant consolidation mechanism present in this system.
Grain Boundary Microstructure of a Hot Isostatically Pressed Silicon Nitride
Authors: Fu L , Hoffmann M J , Pan X 
Published: July 2020

Abstract
Si3N4-based materials exhibit attractive mechanical properties for high-temperature applications. These properties are influenced strongly by the size and morphology of the grain boundaries and grain-boundary phase. An amorphous intergranular film (IGF) commonly exists at two grain junctions. The thickness of these IGFs sensitively depend on the chemical composition of the intergranular phase.In this work, our studies on the grain boundary microstructure of Si3N44 ceramics made by Hot Isostatically Pressing (HIPing).
Si3N44 materials were densified by HIPing Si3N4 powders (UBE E-10) at 1950°C at 200 MPa for 1 hour, with sintering aids of either Y2O3 or Y2O3 + A12O3. Two materials were made: material A consisting of 2 wt% Y2O3; material B consisting of 5 wt% Y2O3 and 1 wt% A12O3. Both as-HIPed and oxided samples were investigated. TEM specimens were prepared by conventional procedures. The microstructure and chemical composition were studied on a JEOL 2000FX.
Characterization of Boron Nitride Coated Silicon Carbide Fibers and Composites
Authors: Gopal Mani 
Published: July 2020

Abstract
Silicon carbide (SiC) composites are receiving much attention for structural use at high temperatures. One class of composites are those reinforced with SiC fibers. The SiC fibers are coated with boron nitride (BN) which is weakly bonded to the fiber. During fracture, the coating deflects cracks causing pull-out of the fibers (Fig. 1). This process of fiber pull-out consumes energy and increases the toughness of the composite. Although much work has been done on characterizing these materials by SEM, not much has been done using TEM due to difficulties in specimen preparation. The purpose of this study is to characterize these fibers and composites using conventional and analytical TEM.
In this study, TEM specimens were prepared by dimpling and ion milling. Careful control of the preparation was needed to ensure the integrity of the SiC-BN interface. Figure 2a is a TEM image of the fiber showing delamination at the SiC-BN interface.
Small Onions Formation Under Electron Irradiation of Turbostratic Bc2n and Turbostratic Bn
Authors: Stephan O , Bando Y , Kurashima K 
Published: July 2020

Abstract
After the discovery of C fullerenes and C nanotubes grown in the vapor phase, the formation of carbon onions [1] in the condensed phase from the irradiation of graphitic polyhedral particles with an intense electron beam gave further evidence that spherical carbon network can be favored under high temperature and strong irradiation regimes. Recently, BN and B-C-N hybrid nanotubes were synthetized. In spite of theoretical predictions, so far there has been no experimental evidence for the stability of B-N and B-C-N analogs of buckminster fullerenes. We exposed turbostratic BC2N and turbostratic BN samples to intense electron irradiation to study the ability of the honey comb network to include non hexagonal member rings and form curved structures.
In the experiments described here, the BC2N starting materials were synthesized from vapor phase reaction (CVD) of BC13 and CH3CN. Such samples were then exposed to high temperature-high pressure (HT-HP) conditions at 7.7.
Formation of Nickel Ferrite Films by Solid-State Reaction
Authors: Johnson Matthew T , Kotula Paul G , Barry Carter C 
Published: July 2020

Abstract
Nickel ferrite (NiFe2O4) thin films are of potential interest for magnetic applications. In the present study, the production of NiFe2O4 by solid-state reaction between thin films of hematite (α-Fe2O3) and nickel oxide (NiO) on (0001) sapphire (α-Fe2O3) substrates has been examined. The NiFe2O4 thin films were prepared by two different methods. In the first case the NiFe2O4film was grown in situ in the deposition system, while in the second case the NiFe2O4 film was formed ex situ by reacting at elevated temperatures in air. These two methods of reaction lead to interesting morphological differences in the ferrite layers.
Epilayers of α-Fe2O3 followed by NiO were deposited onto (0001) α-Al2O3 by pulsed-laser deposition (PLD) in 6 mTorr O2. NiFe2O4 films were obtained by reacting the starting films in two different ways: in situ (during film growth) and ex situ.. In both cases, the α-Fe2O3 films were grown under the same conditions while those for the deposition of the NiO layers were different.
The Dynamics of Mgo Surface Faceting
Authors: Yanina Svetlana V , Johnson Matthew T , Barry Carter C 
Published: July 2020

Abstract
The {001} surface of magnesium oxide (MgO) has been the focus of numerous studies, which were prompted by the importance of MgO for its use as a substrate for thin film growth and also as a chemical catalyst. In the present work, atomic force microscopy (AFM) was used for studying the dynamics of surface processes of MgO which occur at elevated temperatures. AFM was chosen, in part, because it allows for imaging of topographical details at the atomic level with minimal sample preparation. Additionally, because the surface morphology of the same area was traced through a series of heat treatments, scanning electron microscopy analysis would be difficult because no conductive coating could be used (such a coating may have altered the surface between subsequent heat treatments).
AFM images were recorded in contact mode, in air, on a Nanoscope III (Digital instruments, Santa Barbara, CA) using Si3N4 cantilevers (Ultralevers, Park Inst., Sunnyvale, CA) with a nominal applied force of 10-15 nN.
Contrasting Cation Distributions in Spinels of Similar Composition
Authors: Fernandes TRC , Echer CJ , Krishnan Kannan 
Published: July 2020

Abstract
Chromite mined from the Great Dyke in Zimbabwe is used for the production of about 180 000 tonnes of ferroalloy per annum, equivalent to about 6% of the world’s supply. The chemical and physical characteristics of the ores, which vary even within the same seam, affect the carbon content of the ferroalloys and hence their commercial value. The purpose of this study is to examine some of the differences between two extremes of chromitites, sheared and unsheared, used in the ferroalloy industry in Zimbabwe to provide a better understanding of the factors that influence the composition of the alloys as a basis for process mineralogy.
The ores consist of chromium spinels (MgAlCrFe)3O4 with a lattice of alternating non-equivalent planes of tetrahedrally coordinated A sites and octahedrally coordinated B sites. The distribution of five major cations (Mg2+, Al3+, Fe2+, Fe3+ and Cr3+) was examined by the technique of electron channelling.
Complementary Analysis Using Polarized Light and Scanning Electron Microscopy in the Determination of Sulfate Attack on Concrete
Authors: Park J I 
Published: July 2020

Abstract
A high water to cement ratio in concrete produces excessive porosity in the paste, thereby increasing the concrete’s susceptibility to sulfate attack and subsequent premature deterioration. Widely used as a building material, concrete experiences physical and chemical deterioration whose extent and nature may be determined by polarized light microscopy (PLM) and scanning electron microscopy (SEM). New software innovations allow exact image relocation in PLM and SEM, thereby producing complementary information which aids in analyst recognition and increases the effectiveness of each analytical technique.
Although overlapping information may be derived using both PLM and SEM, each technique has inherent advantages and disadvantages which complement the other. The advantages of PLM include a color image, good low magnification resolution providing a bridge between macro/micro analysis, and the ability to distinguish polymorphs and materials of nearly identical composition (e.g., solid-solution series components). Disadvantages of PLM include limited high magnification potential, mineralogical identification based on the analyst’s knowledge of optics, and the need for photographic attachments.
Reinvestgation of Tweed Microstructures in Annealed Albite
Authors: Kim Y J , Lee S H , Lee J C 
Published: July 2020

Abstract
Previous TEM study of natural Amelia albite (Ab99.3An0.1Or0.6) isothermally annealed at 1073°C for various periods revealed distinct tweed microstructures from the intermediately disordered albite samples (intermediate albite), but not from both the natural sample (low albite) and the highly disordered samples (high albite).1 These tweed microstructures seemed to correlate well with the degree of peak broadening and distortion in corresponding conventional powder X-ray diffractograms. Previous XRD, synchrotron radiation and TEM studies on the annealed albite samples at 1080°C for various periods gave rise to similar results.
Reinvestigation of the annealed albite samples with distinct tweed microstructures by TEM confirmed their existence in wide areas, giving two-directional streaking in the corresponding SADP’s (Fig. 1 and 2). Tweed directions are roughly perpendicular to and parallel to the trace of albite twin plane, {010}, as shown in Fig. 3. This tweed microstructure is apparently unaffected by the twinning and probably formed after it.
Analysis of Asbestos Fibres in The Scanning Electron Microscope (SEM) by The Use of Electron Backscattering Diffraction (Ebsd).
Authors: Raanes M , Hjelen J 
Published: July 2020

Abstract
Asbestos is a common name of a number of fibrous mineral silicates which differ in chemical composition. The asbestos fibres are classified into two groups: serpentine (chrysotile) and amphiboles (anthophyllite, amosite, actinolite, tremolite, crocidolite).
Inhalation of asbestos dust fibres involves a health risk. It is therefore of great importance to develop quick and reliable methods to check for the presence of asbestos fibres in suspected materials. Some common analysis methods for asbestos detection are: optical microscopy scanning or transmission electron microscopies (SEM,TEM) often combined with energy dispersive X-ray analysis (EDX) and selected area electron diffraction (SAED) in the TEM where the crystal structure is determined.
The EBSD technique in the SEM has in this work been applied to achieve electron backscattering patterns (EBSP) from four types of asbestos fibres. The pattern quality has been studied as a function of specimen preparation and SEM settings.
An Electron Microscopy Method for Bulk Sample Analysis for Presence of Asbestos
Authors: Daniel Barron  , Kecskes Laszlo J 
Published: July 2020

Abstract
A method has been developed to identify asbestos-bearing samples. This technique, using scanning and transmission electron microscopy (SEM/TEM) coupled with X-ray fluorescent spectroscopy (XFS), X-ray elemental spectral analysis (EDS/EDAX), and X-ray diffractometry (XRD), supplements the traditional use of dispersion staining and polarized-light optical microscopy. The traditional method is subject to a statistical variance associated with analyzing a small volume of sample and projecting the results to the entire volume of the sample which in many cases is non homogeneous. [1] The simultaneous use of the aforementioned analyses in the new method improves the quantitative identification of highly heterogeneous unknowns.
The primary purpose of this study was to determine the essential steps of the identification process that will serve as the basis in the development of an automated particle/fiber recognition program. Five commercially pure asbestos samples of actinolite, amosite, chrysotile, crocidolite, and tremolite, and four common ‘household’ samples were examined.
Unusual SEM Image Contrast from Corrosion Oxide Films of Zr-2.5%Nb Pressure Tube Alloy
Authors: Lin Y P , DeLuca J 
Published: July 2020

Abstract
Zr-2.5wt%Nb alloy is used as the pressure tube material in CANDU reactors. The pressure tube microstructure consists primarily of α-Zr (&lt; l%Nb) grains elongated in the axial direction of the pressure tube and typically 0.3-0.5 μm thick in the radial direction. The α-Zr grains are partially surrounded by a thin layer of Nb-rich β-Zr phase (≈ 20%Nb). During corrosion, α-Zr is converted primarily to monoclinic ZrO2 with minor amounts of tetragonal ZrO2. Oxidation of α-Zr is complicated by the metastable nature of the phase below 863K. A detailed understanding of the nature of oxidized β-Zr remains a topic of on-going investigation, although some information have recently become available. Present SEM observations shed some lights on the charging characteristics of the oxidized β-Zr compared with ZrO2.
Oxide films on pre-polished surfaces perpendicular to the radial direction of the pressure tube were grown in steam at 673K in an autoclave; the treatment corresponds to the last stage of the pressure tube production.
Surface Analysis of Shear Strength Tested Tungsten Carbide Thermal Spray Coatings+
Authors: Bailey GW , Dimlich RVW , Alexander KB , McCarthy JJ , Pretlow TP , Naidu S V , Green Carlos , Maxie Christopher , Garber James D , Glass Gary A 
Published: July 2020

Abstract
Thermal spray processing has become an important powder-consolidation technique to yield new materials for extremes of temperature, radiation, wear, corrosion and mechanical stresses. High Velocity Oxy-Fuel (HVOF) spray coating process gives higher deposition densities and coating hardness; lower oxide content and porosity. The adhesive strength of thermal spray coatings is greatly effected by the interfacial impurities. The ring shear test method shown in Fig. 1 appears to give the most accurate results on shear adhesive strength. A typical ring shear test result of 88WC12Co 1/4" ring HVOF thermal spray coating on 4140 steel rod using a Jet kote thermal spray gun is shown in Fig. 2. Repeated ring shear tests on similar samples prepared under same spray and test conditions resulted in different shear bond strength and coating ring displacement before break off. We examined the ring shear tested coatings using a Zeiss DMS942 Scanning Electron Microscope (SEM) and Kevex Energy Dispersive X-ray Spectrometer (EDXS) with LPX1 Quantum Si(Li) Detector.
Attempts to Visualize Conformational Changes in a Single Protein Molecule During Function
Authors: Bailey GW , Dimlich RVW , Alexander KB , McCarthy JJ , Pretlow TP , Kinosita Kazuhiko , Yasuda Ryohei , Sase Ichiro , Miyata Hidetake 
Published: July 2020

Abstract
The operation of protein molecular machines is essentially stochastic. One cannot predict exactly when an ion channel opens, or when a molecular motor makes a step. As such, working molecular machines cannot be synchronized with each other in a rigorous sense. To understand the mechanism of a protein machine, therefore, one has to watch conformational changes of individual molecules while they are at work. To this end, we have been trying to develop two approaches based on optical microscopy. One is to attach a small tag, a fluorescent probe, to an appropriate site on the protein molecule of interest. Polarization of the probe fluorescence, for example, will reveal the orientation of the fluorophore, and thus of the portion of the protein molecule to which the fluorophore is attached. A conformational change of the protein will be detected as the reorientation of the fluorophore. A prerequisite is the ability to image a single fluorophore in an aqueous environment, which we have achieved on an epifluorescence microscope by reducing its background luminescence by two orders of magnitude
Simultaneous Optical Measurements of Cellular Membrane Potential and Volume in Epithelia
Authors: Gross Eitan , Hopfer Ulrich 
Published: July 2020

Abstract
An important function of renal epithelial cells is the reabsorption of volume, Na+ and bicarbonate (HCO3) from the filtrate. About 85% of the filtrate’s HCO3− − and 70% of the Na+ are being reabsorbed in the proximal tubule segment of the nephron. As a result, these cells are being continuously subject to large fluxes of Na+ and base through the cell. Renal medullary cells, for instance, are being subject to large fluctuations in osmolality of the extracellular fluid. Transient imbalances in fluid, base and Na+ flow through the cell can cause substantial alterations in cellular volume, pH and electrolytes.
The regulation of transepithelial transport on one hand and of cellular volume-, pH- and electrolyte-homeostasis on the other hand, is of a major physiological interest. Angiotensin II (Ang II) is a powerful regulator of Na+and HCO3 − transport in the proximal tubule. The involvement of ion channels and electrogenic transporters in cellular homeostasis, has been studied by many laboratories using conventional elecrophysiological techniques to measure the resulting changes in membrane potential and ionic currents.
Recent Developments in Confocal Raman Microprobing and Imaging Techniques
Authors: Paul Dhamelincourt 
Published: July 2020

Abstract
This communication presents a summary of the most recent developments in microRaman instrumentation - point analysis and imaging techniques- including the use of confocal optics and line illumination, as now available in certain commercial instruments.
The major development in micro-Raman spectroscopic instrumentation during the last few years is based on the extension of the principles of confocal microscopy. Applied to Raman microprobing the confocal technique provides an efficient way to obtain interference-free Raman spectra, as well as two-or three-dimensional, selective images of small specimens embedded within strong scatterers or fluorescent transparent media. As it is well known, the confocal configuration benefits from the use of spatial filtering by optically conjugated pinhole diaphragms. Such a system isolates the light originating from a small region of the sample coincident with the diffraction-limited, focused laser spot, and efficiently eliminates the contributions from out-of-focus zones.
A new concept of Raman imaging that benefits from the advantages of confocal microscopy has been developed in this laboratory.
Confocal Raman Microscopy of Chromosomes, Cells and Eye-Lenses
Authors: Greve J , Sijtsema NM , de Grauw CJ , Duindam H , Wouters S , Otto C , Vrensen GJ 
Published: July 2020

Abstract
A confocal scanning Raman microscope was constructed for spectroscopy and microscopy of biological samples (Fig. 1). The microscope contains an illumination system in which a focused krypton laser beam, of which the 647.1 nm line is used to reduce damage, is scanned over the sample using a scanning mirror which moves around two orthogonal axes. Raman scattered light is collected by a water immersion objective which directs the light on the scanning mirror. Spectral analysis takes place in a monochromator with two exit ports: one for spectroscopical purposes the other one for imaging. An image is made by scanning the light, present in the Raman band passed by the monochromator, over a CCD using a second scanning mirror which moves synchronously with the first mirror. The spatial resolution is of the order of 0.3 × 0.3 × 1.2 μm3 (x,y,z).
With this microscope we studied the following samples: