bluuebunny/crossref_metadata_2025_split huggingface dataset:
Energy-dispersive x-ray microanalysis in the earth sciences
Authors: Ware N. G. 
Published: June 2020

The electron microprobe analyser (EMPA) is used extensively for the analysis of the constituent minerals in rocks and the samples generated by experimental petrology apparatus. These analyses, combined with the results of field observations and data from other analytical techniques, are used in petrogenetic studies and hence in the determination of planetary formation and evolution. In turn, this knowledge helps the mining industry in their mineral exploration programs.In the 1960s almost all geological usage of the EMPA was confined to the x-ray spectrometry of L3-K lines of elements of atomic number 11 through 30 (Na through Zn). By the end of this decade semi conductor technology had advanced so that these x-ray lines could be resolved using a lithium-drifted silicon detector working as an energy dispersive spectrometer (EDS). Quantitative EDS software was developed in the early 1970s and it became possible to perform major element analyses of silicates, oxides, carbonates and sulphides using a scanning electron microscope (SEM) fitted with an EDS.
The use of x-ray microdiffraction in failure analysis
Authors: File D. M. , Denton L. R. , Henderson P. L. 
Published: June 2020

X-ray microdiffraction is a tool used at NSWC to perform and support failure analyses. Our failure analysis efforts attempt to determine the primary cause(s) of the failure and to recommend corrective action(s) in a timely manner. The analytical techniques used include Secondary Ion Mass Spectrometry (SIMS), Scanning Electron Microscopy (SEM), Auger Electron Spectroscopy (AES), and Electron Probe MicroAnalysis (EPMA). The addition of x-ray microdiffraction has provided additional capability which supports the elemental analyses, and has often reduced the analysis time required to identify the failure mode.X-ray microdiffraction can provide the following capabilities: 1) qualitative analyses, 2) quantitative analyses, 3) degree of crystallinity, 4) measurement of residual stress, 5) grain or particle size, 6) texture or preferred orientation, and 7) analysis of small samples (∼10 μm to 20 μm diameter). In addition, these analyses can usually be performed in a few minutes to an hour.X-ray microdiffraction has evolved steadily over the past 15 years.
Basic image processing for the microscopist
Authors: Bright David S. 
Published: June 2020

Images are a rich source of easily interpreted information. Equipment capable of handling pictures in computer memory (digital images) is now commonplace, and imaging is becoming an integral part of scientific computing and data analysis. Today, desk top computers are capable of displaying images with no special equipment at all. For example, NIH Image runs on a standard MAC II, and provides tools for contrast enhancement, pseudocolor, sharpening, animation, labeling and particle counting. Scanners or video cameras to input gray level (or color) images are moderately priced, and scanning microscopes are coming equipped for digital data acquisition and control. This tutorial will review some of the basic principles of image processing using example micrographs, and will illustrate how to use some readily available image processing software.Digital images are pictures that reside in the computer as arrays of numbers, each number designating the brightness of an individual picture element or pixel.
Fundamental parameters of x-ray microanalysis: A brief introduction
Authors: Duncumb Peter 
Published: June 2020

It is indeed fortunate that nature has provided us with such well-defined physical laws governing the generation of x rays and their interaction with matter. This benefit has given electron microprobe analysis two major advantages over many other techniques of analysis: it can be applied to almost all elements in the periodic table and it can be applied quantitatively. Nevertheless, we are continually striving for better and better quantitation over a wider range of conditions, and there is a corresponding pressure to improve our knowledge of the physics. The purpose of this session is to identify the fundamental parameters by which these physical laws are expressed, and to explore their relative importance in determining the accuracy of which the technique is capable.The essential link between the basic physics of microprobe analysis and its useful application is the physical model used to represent the process numerically. Many such models have been proposed in the past 40 years and these are properly the subject of a separate session on quantitative analysis.
Electron Scattering in Solids
Authors: Shimizu Ryuichi , Ding Ze-Jun 
Published: June 2020

Monte Carlo simulation has been becoming most powerful tool to describe the electron scattering in solids, leading to more comprehensive understanding of the complicated mechanism of generation of various types of signals for microbeam analysis.The present paper proposes a practical model for the Monte Carlo simulation of scattering processes of a penetrating electron and the generation of the slow secondaries in solids. The model is based on the combined use of Gryzinski’s inner-shell electron excitation function and the dielectric function for taking into account the valence electron contribution in inelastic scattering processes, while the cross-sections derived by partial wave expansion method are used for describing elastic scattering processes. An improvement of the use of this elastic scattering cross-section can be seen in the success to describe the anisotropy of angular distribution of elastically backscattered electrons from Au in low energy region, shown in Fig.l. Fig.l(a) shows the elastic cross-sections of 600 eV electron for single Au-atom, clearly indicating that the angular distribution is no more smooth as expected from Rutherford scattering formula, but has the socalled lobes appearing at the large scattering angle.
A Wien Filter Electron Energy Loss Spectrometer for Transmission Electron Microscopy
Authors: Tsuno K. , Ohyama J. , Kato M. , Kimura J. , Kai M. , Nakanishi K. , Terauchi T. , Tanaka M. 
Published: June 2020

A retarding Wien filter has been installed in the transmission electron microscope (TEM) JEM-1200EX. The filter is immersed in a high potential (-Ht + Uo ) nearly equal to the accelerating potential (-Ht) to get high energy resolution. The Wien filter consists of crossed electric (E) and magnetic (B) fields perpendicular to the optical axis. Electrons with a particular velocity v have a straight optical axis if the balancing condition between electric and magnetic forces (Wien condition: E=vB) is satisfied. Electrons with different velocity are deflected.Fig. 1 shows a schematic outline of the present instrument. It consists of (1) TEM, (2) an analyzer made of the Wien filter, deflectors and post filter lenses, and (3) a TV camera imaging system and serial detection system. The analyzer and a serial detection system are controlled by a personal computer PC-9801VX (PC). Table 1 shows currents and voltages of the filter, lenses and deflectors (upper) and those for TEM (lower).
Electron Spectroscopic Imaging and Diffraction in TEM
Authors: Reimer L. 
Published: June 2020

Energy-filtering electron microscopy at 80 keV (ZEISS EM902) offers the combination of electron spectroscopic imaging (ESI) and diffraction (ESD) and electron energy-loss spectroscopy (EELS). For details the reader is referred to a description of the different modes, applications of ESI to biological and crystalline specimens and of ESD. The very important mode of elemental mapping with the difference of ESI below and beyond an edge will not be discussed in this review.The ESI mode increases scattering contrast of stained and unstained biological sections and avoids chromatic aberration by zero-loss filtering. Filtering at ΔE=250 eV below the C edge increases the (structure-sensitive) contrast by non-carbon atoms of unstained sections (Fig.1). Phase contrast is also increased but inelastically scattered electrons show a faint phase contrast which can be explained by treating partial inelastic waves with different q as incoherent. Bragg contrast of crystalline specimens is enhanced due to avoiding chromatic aberration and a blurring by the spectrum of excitation errors of inelastically scattered electrons (Fig.2).
Lithium Detection in Aluminium Lithium Alloys Using PEELS
Authors: Wilson AR 
Published: June 2020

Aluminium lithium alloys are important alloys for the aerospace industry on account of their good strength to weight properties. However, these alloys suffer from poor short-transverse fracture toughness. Segregation of Li onto the grain boundaries is one mechanism proposed to account for this. Different AlLi alloys have been studied in a 200keV TEM equipped with a Parallel Electron Energy Loss Spectrometer.Typical Li concentrations in these alloys range from 10 to 14 atomic percent (2 to 3 weight percent). This, combined with the proximity of both the Al plasmon and Al L edge and the strong deviation of the Li K edge from the ideal sharp Fermi step makes the detection of Li difficult. Negative “jump ratios”, as shown in fig. 1, make the edge very difficult to see in an unprocessed spectrum and a cursory inspection of such a spectrum might miss the Li the edge. The presence of the Li edge, and also the edge threshold energy, is more visible if the second difference of the spectrum (obtained by convolution with a top-hat filter) is displayed as shown in fig. 2.
Automation of Gunshot-Residue Analysis by Functional Integration of a Scanning Electron Microscope and an Energy Dispersive Microanalysis System
Authors: Peeters Marc H. 
Published: June 2020

Over the past ten years, the combination of scanning electron microscopy and energy dispersive analysis has proven to be a good and reliable tool for elemental characterization of the different components of gunshot residue. The technique evolved from a qualitative technique, involving a large amount of operator involvement, to a higher degree of quantification and automation allowing unattended analysis of gunshot residue samples. The PHAX-Scan system is geared to automated unattended analysis, particularly suited to applications such as gunshot-residue analysis.PHAX-Scan is a system based on a Philips scanning electron microscope and an EDAX PV9900 energy dispersive microanalyser in combination with highly optimised software. The system makes use of the dual processor structure of the EDAX analyser and of the bus structure of the Philips scanning electron microscopes. It is designed such that it performs a fully quantitative data reduction, including background subtraction, peak deconvolution, no-standards k-ratio determination and Z*A*F correction in typically 100 milliseconds.
Nuclear Reactions in Deuterium Titanium
Authors: Vanderwalker D.M. 
Published: June 2020

There is a fundamental interest in electrochemical fusion of deuterium in palladium and titanium since its supposed discovery by Fleischmann and Pons. Their calorimetric experiments reveal that a large quantity of heat is released by Pd after hours in a cell, suggesting fusion occurs. They cannot explain fusion by force arguments, nor can it be an exothermic reaction on the formation of deuterides because a smaller quantity of heat is released. This study examines reactions of deuterium in titanium.Both iodide titanium and 99% pure titanium samples were encapsulated in vacuum tubes, annealed for 2h at 800 °C. The Ti foils were charged with deuterium in a D2SO4 D2O solution at a potential of .45V with respect to a calomel reference junction. Samples were ion beam thinned for transmission electron microscopy. The TEM was performed on the JEOL 200CX.The structure of D charged titanium is α-Ti with hexagonal and fee deuterides.
Comparison of quantitative x-ray imaging and raster probing in heart cells exposed to sodium-free media
Authors: Carney Mary , LeFurgey Ann , Hawkey Larry , Ingram Peter , Lieberman Melvyn 
Published: June 2020

Quantitative biological electron probe x-ray microanalysis (EPXMA) ideally makes use of two approaches in examination of samples: static raster probing and quantitative x-ray imaging. Efficient use of expensive microanalytical equipment requires intelligent decisions on the appropriate strategy for optimizing data collection. A low resolution, short dwell time map (for example, 64 × 64 pixels by 2 seconds) may survey one to several cells at low magnification and provide adequate statistics for most structures and elements. Elements, notably Ca, present in low concentrations within small regions may require the acquisition equivalent of long static raster probes, increased numbers of images from low resolution maps, higher resolution maps, longer dwell time maps, or a combination of these options.We examined raster probe and mapping results in cultured heart cells. In these cells EXPMA has been demonstrated to be an appropriate tool to observe the results of perturbation of the Na-Ca gradient, brought about by incubation of cells in low Na or Na-free media.
Pathophysiological function of the mitochondria as a calcium reservoir: Quantitative x-ray microanalysis
Authors: Teraoka K. , Kaneko N. , Horikawa Y. , Uchida T. , Matsuda R. , Hosoda S. , Nakamura S. 
Published: June 2020

The aim of this study was to elucidate the role of the mitochondria as a store of calcium(Ca) under the condition of pathophysiological Ca overload induced by a rise in extracellular Ca concentration and the administration of isoproterenol.Eight rats were employed, and hearts were perfused as in the Langendorff method with Krebs-Henseleit solution gassed with 95% O2 and 5% CO2. Tow specimens were perfused with 2mM Ca for 30 min, and 2 were perfused with 5.5 mM Ca for 20 min. 4 specimens were perfused with 2 mM Ca for 5 min, and of these 4, 2 were infused with 10-7 mM/kg/min. isoproterenol for 5 min, and 2 were given a bolus injection of 3 x 10-7 mM isoproterenol. After rapid-cryofixation by the metal-mirror contact method with a Reichert-Jung KF80/MM80, and cryosectioning at -160 to -180° C with a Reichert-Jung Ultracut Fc-4E, ultrathin specimens (100nm) were free-ze-dreid for several hours at 10-5 Torr in the JEOL FD 7000, and mitochondrial Ca was determined by quantitative x-ray micranalysis (JEOL 1200EX, LINK AN 10000S).
The effect of averaging parameters on the backscatter correction
Authors: Heinrich Kurt F. J. , Myklebust Robert L. 
Published: June 2020

The backscatter correction is derived from the knowledge of the backscatter coefficient, indicating the number of backscattered electrons, and from the energy distribution of the backscattered electrons. The effect of variations in the energy distribution on the accuracy of data reduction is minor. Unlike the procedure of Duncumb, newer approaches include the calculation of the backscatter coefficient. Since this parameter has been determined experimentally by various investigators this approach lends itself to a more detailed study of its effect on the correction procedure.The backscatter coefficient varies strongly with the atomic number of the specimen, and less so with the operating voltage and the atomic weight of the elemental target. The effect of atomic weight is always neglected; that of the energy is taken into account in the procedure of Scott et al.The method of averaging the components of a multielement target can have a significant effect on the result when major components differ considerably in the atomic number and element standards are used.
Evaluating 30mm2 Si(Li) detectors for light-element x-ray analysis
Authors: Barkan Shaul 
Published: June 2020

Light element x-ray microanalysis with the Si(Li) detecor is dependent on two detector crystal characteristics. The first is resolution, which has been traditionally standardized to be FWHM at Mn Kα. The second factor is efficiency, which is primarily but not entirely established by the detector area. These two factors effect light element sensitivity in an inverse manner. A premium resolution detector can be produced by minimizing the area, but the efficiency, as previously discussed , is directly proportional to the detector area.A special effect of efficiency degradation exists in the very low energy end of the spectrum where the x-ray energy pulses are approximately equal to the electronic noise level. The detector dead layer plays an important role in the low energy detection efficiency, since good, low energy efficiency is much more important than good manganese resolution or good electronic noise resolution.In a common 10mm2 Kevex detector, ~135 eV resolution at Mn is obtainable and the electronic noise resolution is 65 eV.
SEM-EDX: A Simple And Fast Method To Assess Catalyst Poisoning
Authors: Boéchat J. - M. , Cotting J. - A. 
Published: June 2020

A Rhodium on carbon catalyst is used to hydrogenate epoxy compounds in order to selectively obtain saturated cycloaliphatic products leaving the epoxy groups almost untouched. This reaction works well when the catalyst is fresh but it fails to go to completion when the catalyst is used for the second time. A reactivation method was then seeked to get rid of this catalyst poisening. In order to assess the quality of the “cleaned” catalyst, we developped a fast method using the SEM-EDX combination to avoid the long way through the chemical reaction itself and the required analysis.We built sample holders to support the catalyst for analysis. It is a carbon stub with a calibrated cavity in the middle. The catalyst required for analysis is poured in the cavity and the excess is removed so that the surface obtained is flat and flush with the carbon stub itself. It is then loaded in the SEM and an EDX spectrum is acquired with preseted conditions.
Molecular Microanalysis of Tissues
Authors: Reffner John A. , Wihlborg William T. 
Published: June 2020

Fourier transform infrared (FT-IR) microspectroscopy is the most direct and facile technology available for detecting, identifying and mapping molecular species. Biologists have a need to relate molecular chemistry with a tissue's microstructure. While electron microbeam analyses provide elemental maps and both SIMS and micro-Raman spectroscopy demonstrated limited molecular mapping capabilities, complex inorganic and organic materials are not readily amenable to these techniques. Infrared spectroscopic analyses of micro-domains have gained wide-spread acceptance since high sensitivity FT-IR spectrometers and research quality, reflecting optical microscopes were united.Morphologically distinct parts of plant tissue can vary in their chemical composition and these variations can effect the plant's value. Plant biologists and agronomists have been endeavoring to localize the chemical species to individual botanical parts. While microscopy has been useful in establishing plant microstucture, chemical information on cellular components has been difficult to obtain. Molecular microspectral mapping renders these chemical analyses more tractable.The microstructure of the outer portion of a cereal grain consists of four distinct regions, see Figure 1.
Morphometric approaches to the cell biology of normal and injured pulmonary epithelium
Authors: Hyde Dallas M. , Harkema Jack R. , Plopper Charles G. , George Judith A. St. 
Published: June 2020

A comparative overview of the epithelial composition of the respiratory airways emphasizes the complexity and diversity found in different species of mammals. Airway epithelium varies in (1) types of cells present, (2) the same airway level in different species, (3) different airway levels in the same species, (4) abundance and type of both secretory cell and stored secretory product, (5) composition of secretory product, (6) organization at the terminal respiratory bronchiole and alveolar duct junction, and (7) ultrastructure of the same cell type in different species. It is unclear what impact this diversity in the airways of different species has, but it strongly suggests the potential for wide variation in the cellular response to injury. These data emphasize the necessity for careful selection of model species and a thorough knowledge of species-specific cellular morphometric and morphologic characteristics when studying the tracheobronchial epithelium.A critical step in obtaining these data is the use of morphometric and electron microscopic techniques. Fixation and sampling are critical aspects of any morphometric study of the lung.
Cryofixation and X-Ray Microanalysis of Thin Cryosections Applied to Biopsies from the Human Prostate
Authors: Tvedt Kåre E. , Halgunset Jostein , Kopstad Gunnar 
Published: June 2020

In order to make needle biopsies more readily applicable to cryo-ultramicrotomy and x-ray microanalysis, we have developed a method which permits biopsy specimens to be frozen immediately after removal from the patients, using metal mirror freezing.Then tissue sample is quickly transferred from the biopsy needle to a formvar film which in advance has been supplied with a drop of standard solution containing PVP and inorganic salts. Freezing is performed by clamping the sample between the cylindrical copper jaws of a pair of pliers, precooled in liquid nitrogen (fig.l). The flat specimen is cut in a Reichert-Jung Ultracut/FC4 cryosystem. The section is collected on a grid/retainer assembly, which is mounted inside a. transportable press. Secured between two grids inside the press, the sections are transferred to an external freeze-drier.This system makes it possible to freeze,even small pieces of tissue using the metal mirror freezing method. The pliers produce a flat specimen containing the tissue and the elemental standard, with two well-frozen surfaces which readily can be sectioned using a flat specimen holder.
Investigation of Ion Beam Sputter Mechanisms by Electron Beam Techniques
Authors: Guerlin Th. , Niedrig H. , Sternberg M. 
Published: June 2020

The mechanisms of unisotropic atomic emission from single crystals under ion bombardment (Ar+, E < 25keV) have been investigated by depositing the sputtered atoms in a semi-spherical collector. A subsequent determination of the thickness distributions of the deposited films by electron backscattering gives the total angular atomic emission distribution, showing maxima in certain crystallographic directions of the sputtered target crystal: Wehner spots.Several mechanisms for the appearance of spot patterns are discussed in the literature:1.For normal incidence of the ions collision cascades are assumed with finally isotropic momentum distributions within the target crystal. Then a momentum transfer to atoms near the target surface may be possible by the following models (fig. 1):1a.Collision sequences along close packed atomic chains (e.g. the <110> direction in fcc crystals). If the residual collision energy exceeds the surface binding energy the atom at the surface end of the chain is emitted into the chain direction: Focusson model (fig. 1a).1b.Emission of subsurface atoms through potential minima between surface atoms (fig. 1b), and emission of surface atoms by central collision of subsurface atoms (fig. 1c). Both processes lead to emission into preferred directions: Surface model.