bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microstructure of silicon implanted with MeV gold ions
Authors: Kim M.J. , Catalano M. , Sjoreen T.P. , Carpenter R.W. 
Published: June 2020

High-energy implantation of silicon is of great interest in recent years for microelectronics due to the formation of a buried damage or dopant layer away from the active region of the device. The damage nucleation and growth behavior is known to vary significantly along the ion's track for MeV irradiation. In this paper, a detailed characterization of the damage morphology produced by MeV gold ions for different doses into single crystal Si, as well as the associated annealing behavior, is presented.Single crystal n-type Czochralski silicon {001} wafers were implanted with Au++ ions from doses of 1x1015 to 3x1016 cm-2 at 2-3 MeV. Specimen temperatures for all implantations were 20 or 300°C. A measurement with an infrared pyrometer of the implanted surface indicated a slight temperature rise during ion irradiation. The compositional and damage profiles were determined by Rutherford backscattering/channeling spectroscopy (RBS). Cross-sectional TEM samples for microstructural characterization were prepared by mechanical polishing and ion milling. A Philips 400ST/FEG analytical microscope was used for nanoprobe experiments, at 100 kV. Microstructural investigation was performed using ISI-002B and JEM-2000FX microscopes, at 200 kV.
Microstructural characterization of oxygen-implanted poly-Si layers
Authors: David Theodore N. , Huang WenLing M. 
Published: June 2020

Poly-Si layers were evaluated that had been exposed to varying doses of oxygen-implant prior to an anneal. The layers were doped (by implantation) with arsenic. Oxygen implantation was found to modify the conductivity of the doped poly-Si films. The microstructural behavior of the films was of interest (as potentially enabling explanation of the modified conductivity).The oxygen implant doses investigated in this study were 1E14 and 1E16 cm-2. The arsenic dose used (dopant incorporated by implantation) was 1.3E13 cm-2. The oxygen-implantedpoly-Si layers were annealed (rapid-thermal anneal, “RTA“) at 1050°C for 30 seconds. Cross-section TEM specimens were prepared in the 110 substrate-geometry, and plan-view TEM specimens in the 100 substrate-geometry. These were then analyzed using selected-area diffraction, bright-field, and dark-field images under gradually varying conditions of electron-beam tilt. A JEOL JEM 200CX transmission electron microscope was used for analysis, operating at 200 kV.
Recent Advances in the Use of Cathodoluminescence for the Study of Geological Materials
Authors: Wright P. J. , Kearsley A. 
Published: June 2020

CL examination of geological materials has in the past been performed using optical microscope based systems that have incorporated a vacuum chamber and electron flood gun attached to the sample plinth. The use of these for the study of materials such as quartz has been limited due to the low accelerating voltages (V ≤ 10 kV) employed coupled with extremely low photon collection efficiencies.Electron microscope based systems are not subject to these limitation since collection optics offering efficiencies approaching 80% may be used. In addition, a range of accelerating voltages up to 10kV are routinely available. Until recently, only monochrome images displaying intensity variations were obtainable. It is now possible to obtain colour images displaying both wavelength and intensity variations across samples with a resolution that exceeds that of optical based systems.
Andradite grain boundary secondary electron image generated by high-intensity electron beam in an electron microprobe
Authors: Liu D. R. 
Published: June 2020

The calcium iron silicate Ca3Fe2Si3O12, which is also called andradite, is commonly used for simultaneous verification of wave-length spectrometers in the CAMECA SX-50 electron microprobe. However, an interesting phenomenon was observed that the grain boundaries, which would not show up under normal secondary electron (SE) imaging conditions, would delineate themselves at high beam current.The SX-50 microprobe was operated in the voltage range of 10 to 20 kV. The probe current was varied from a few nA to a few hundred nA. The surface of the andradite sample was polished and carbon coated. When the beam current was only a few nA, the SE image showed only surface scratches and other surface defects such as pits (Fig. 1). However, if the current was increased to above 100 nA, the grain boundaries, which were hidden under the sample surface and thus invisible at low probe current, would then show up clearly (Figs. 2 and 3).
Dislocation structure in melt-textured YBa2Cu3O7-x
Authors: Burke T. G. , Mitchell T. E. 
Published: June 2020

Presently, there is considerable interest in the microstructure of melt-textured YBa2Cu3O7-x (MT-Y123) and its influence on flux pinning. Precipitates of Y2BaCuO5 are a common feature of the microstructure. In addition, the stacking faults associated with the insertion of an extra CuO plane may contribute to flux pinning. Thus far, the stacking faults reported have been isolated, i.e. not forming a network. There is reason to believe that an array of stacking faults would be beneficial in increasing the flux pinning, thus increasing the critical current density of MT-Y123.The material studied was prepared by CPS Superconductor Inc. by holding a mixture of YBa2Cu3O7-X and Y2BaCuO5 Just above the peritectic temperature for 1 hour and quenching to just below the peritectic for 15 hours. Samples were then subjected to an oxygen annealing. It has large, highly textured grains which measure as much as 1cm in the a-b plane. TEM samples were cut parallel and perpendicular to the caxis. The samples were polished, dimpled and ion milled at 13° in a liquid nitrogen cold stage. A Philips CM30 microscope, operated at 300kV, was used in this study.
Microstructural characterization of YBa2Cu3O7-x thin films formed by metalorganic CVD
Authors: Lu P. , Huang W. , Chern C.S. , Li Y.Q. , Zhao J. , Kulesha G.A. , Gallois B. , Norris P. , Kear B. , Cosandey F. 
Published: June 2020

The YBa2Cu3O7-x thin films formed by metalorganic chemical vapor deposition(MOCVD) have been reported to have excellent superconducting properties including a sharp zero resistance transition temperature (Tc) of 89 K and a high critical current density of 2.3x106 A/cm2 or higher. The origin of the high critical current in the thin film compared to bulk materials is attributed to its structural properties such as orientation, grain boundaries and defects on the scale of the coherent length. In this report, we present microstructural aspects of the thin films deposited on the (100) LaAlO3 substrate, which process the highest critical current density.Details of the thin film growth process have been reported elsewhere. The thin films were examined in both planar and cross-section view by electron microscopy. TEM sample preparation was carried out using conventional grinding, dimpling and ion milling techniques. Special care was taken to avoid exposure of the thin films to water during the preparation processes.
Photoelectron Microscopy And Quantum Yields Of Membrane Phospholipids.
Authors: Hayes Griffith O. , Dam Rudy J. 
Published: June 2020

Contrast in photoelectron microscopy (PEM) depends on differences in the absolute photoelectron quantum yield defined as the number of electrons released divided by the number of incident photons. Recently, the photoelectron quantum yields of the amino acids and homopolymers were measured (1). These data define the range of quantum yields expected from membrane proteins. The other major membrane component is lipid and we report here the photoelectron quantum yields of the common phospholipids.Synthetic L-α-dipalmitoylphosphatidylcholine (DPPC), L-α-dipalmitoylphosphatidylethanolamine (DPPE), L-α-dipalmitoylphosphatidylserine (DPPS), dipalmitoylphosphatidylglycerol (DPPG), and bovine heart diphosphatidylglycerol (DPG, or cardiolipin) were obtained commercially. DPPS, DPPC and DPPG were estimated to be at least 90% free of organic impurities by TLC analysis and DPPE and DPG migrated as single spots. Commercial, 99+% pure cholesterol was recrystallized from a chloroform:methanol (2:1 v/v) solution.
Subsurface Cisterns in the Dog Retina
Authors: Ladman J. 
Published: June 2020

Since subsurface cisterns (SSCs) were first described in various neurons of the brain and spinal cord (1), several reports have appeared noting their presence in cells of the retina (2-8). SSCs have been reported to occur in photoreceptors in the guppy as well as in amacrine, bipolar and ganglion cell bodies in rabbit, squirrel and cat. This study extends observations of the SSC to the dog retina.All retinas were immersed in Caulfield's fixative at 4°C for l½-2 hrs., stained en bloc with 1% magnesium uranyl acetate and embedded in Epon. SSCs consist of two apposed membranes, pentilaminar in structure and unusually electron dense, of variable length in profile (0.1-0.8μm) and found immediately subjacent to the plasmalemma of ganglion, amacrine and horizontal cells in the dog. They appear to be more prevalent in the ganglion cells, perhaps because of the larger surface area which the plasma membrane occupies in this particular cell type (Fig. 1). Immediately internal to the SSC is an element of the endoplasmic reticulum on the cytoplasmic surface of which can be seen an occasional ribosomal particle (Fig. 2).
Immunocytochemistry of Surface Changes in Ascaris Spermatozoa During Maturation
Authors: Bradley Ronald H. , Burghardt Robert C. 
Published: June 2020

Substances removed from the male accessory gland in Ascaris have been shown to induce the immotile, spherical spermatozoa to become active ameboid cells. This change Indicates the advent of the sperm's competency to penetrate oocytes and therefore represents the final maturation of the spermatozoa. Although the morphological changes of these altered active spermatozoa have been well defined (1 and 2), the qualitative differences in the plasma membrane have not been followed in detail.In the present study, antibodies were prepared against both the inactive and active Ascaris spermatozoa in female Australian white rabbits by weekly intramuscular injections of washed cell populations in combination with Freund's complete adjuvant.
Ultrastructural Characteristics of Platelets Separated from Plasma by ADP-Induced Aggregation
Authors: Shinoda B.A. , Hardison M.D. , Mohammad S.F. , Chuang H.Y.K. , Mason R.G. 
Published: June 2020

The utilization of blood platelets in experimentation frequently requires their separation from blood and subsequent resuspension in media of known composition. Several methods are available for preparation of isolated platelets (1-3) by differential centrifugation or gel filtration, but most methods are tedious and time consuming. Often platelets obtained by use of such methods are in a state different functionally and ultrastructurally from that of platelets in plasma (4).Recently Mohammad, Reddick, and Mason (5) reported a method in which platelets were separated from plasma by ADP-induced aggregation, washed several times, and then incubated in a carefully selected medium that resulted in deaggregation of platelets.
Ultrastructure of the Submandibular Gland of the Nine-Banded Armadillo
Authors: Ruby J. R. 
Published: June 2020

It has been demonstrated previously that there are variations in the histochemical staining of the acinar cells in the submandibular gland of the armadillo (1). This suggested that the gland may be composed of several lobes, each of which contains different acinar cells. The present investigation confirms that the submandibular gland of the armadillo has a major and minor lobe. Both lobes deliver their secretions to the salivary bladder which is the dilated, proximal portion of the main duct of the gland. These lobes are very different, however, with respect to their histochemistry and ultrastructure.The acinar cells of the major lobe stain lighter with PAS and alcian blue than those of the minor lobe. The demilune cells, however, exhibit a more intense reaction with these stains.
An Ultrastructural Comparison of Rat Lung Cells Grown in an Organotypic Culture System with Lung Tissue Found in the Whole Animal
Authors: Del Vecchio Peter J. , Dougherty Edward P. , Douglas William H. J. 
Published: June 2020

This study describes the ultrastructure of an organotypic system prepared from rat fetal lung and compares it to lung in rat fetuses. The preparation of the organotypic system has been described elsewhere (1).The organotypic systems in this study are prepared from 18-19 day fetal rat lung and spend two days in culture making the cells a total of 20-21 days old. The fine structure of the type II cells present in this system will be compared to the type II cells in fetal lung at 20-21 days gestation. Because the tissue organization of the organotypic system is more like the organization of fetal lung at an earlier stage (18-19 days gestation) , the cell to cell relationships of the organotypic system are compared to fetal lung tissue at this stage.The histology of the organotypic system is similar to that of the fetal lung in its glandular stage (Fig. 1). The epithelial cells are all columnar and are surrounded by relatively undifferentiated mesenchyme.
Morphology of Abnormal Columns of Mesenchyme Cells in the Channel Catfish, Ictalurus Punctatus.
Authors: Henderson Vernon 
Published: June 2020

During recent years , I have utilized several thousand young channel catfish or fry for several different studies. A few years ago, I noticed an increase in the number of adipose fins which showed fin ray-like structures. Fin rays in adipose fin of fish are rare. Assuming that the said structures were fin rays, I proceeded to study them, histologically. Upon microscopic examination, it was discovered that there was a complete absence of fin ray elements. In an effort to understand the structural changes responsible for the appearance of the ray-like elements , an electron microscopic analysis was undertaken.Fish used in this study were secured from several different catfish farms located in the Grambling area; however, all seem to be linked to a common source from which brood stock had been purchased. The specimen used in this study ranged in length from 7.5 centimeters to 15.0 centimeters and were approximately four to six months in age.
A Morphological Study of the Nephridium of Lumbricus Terrestris: A Correlate of the Mammalian Nephron?
Authors: Anderson T.L. , Martin B.J. 
Published: June 2020

The nephridium is a tubular excretory structure characteristic of coelomate invertebrates such as the annelid, Lumbricus terrestris (earthworm).Nephridial function compares to that of the mammalian nephron in that they both perform four basic tasks: filtration, electrolyte resorption, fluid regulation, and excretion. In the flux created by the constant synthesis and breakdown of body constituents, excess materials are removed by filtration, detoxified, and excreted. In terrestrial animals, this process requires electrolyte secretion and resorption in order to maintain fluid balance.In Lumbricus terrestris, there are (essentially) two nephridia per segment. Each appears to consist of one continuous tubule, differentiated into a series of three specialized loops: Short, Long, Thick (FIG. 1).
Junctional Systems in a Human Breast Carcinoma Cell Line (MCF-7).
Authors: Russo J. , Bradley R.H. 
Published: June 2020

The epithelial cells of the normal human breast are tightly joined by junctional complexes composed of tight junctions, intermediate junctions, and desmosomes. Similar junctions have been reported in several types of breast carcinoma. In the present paper we report on the junctional systems observed in a human breast carcinoma cell line (MCF-7) (1).MCF-7 cells cultured in Eagle's minimum essential medium, after 40-160 transfers were fixed simultaneously in glutaraldehyde and osmium according to the method of Hirsch and Fedorko (2), and were stained in uranyl acetate in block. After dehydration, the samples were detached with propylene oxide and embeded in Epon-Araldite (3). Sections were examined in an Hitachi HU-11A electron microscope after staining with uranyl acetate.
In Vivo Growth and Development of Equine Adenovirus in the Lung of Arabian Horse
Authors: Kim J. C. S. 
Published: June 2020

Arabian foals are more susceptible to adenovirus infection because of the generalized immunodeficiency resulting from a genetic defects (1, 2) . The disease is characterized by pneumonia, intermittent fever, and high mortality. Severe lymphopenia has accompanied the fatal infection in foals (3). The growth and multiplication of adenoviruses, in general, has been studied mainly in suspension cultures of KB, Hela and other renal tissue culture system (4). Whether a similar multiplication cycle is occurring in vivo has not been determined.Pulmonary tissues from a necropsied arabian horse were processed for electron microscopy. Thick sections of infected lung show numerous intranuclear inclusion bodies in the bronchial epithelium. Serial thin sectioning of the same area indicates occurrence of various developmental stages of adenovirus multiplication. This report summarizes our morphologic observation made in vivo and compare to what is known in vitro system.
Tem Studies of Hen's Perivitelline Membrane Hydrolysis by Cock Sperm in Vitro
Authors: Bakst M. R. 
Published: June 2020

In a manner analogous to the way in which the zona pellucida envelops the mammalian ovum, a single acellular investment, the perivitelline membrane (PM), uniformly covers the hen's ovum at the time of ovulation. It consists of a fiberous latticework 2-4μm in width with interstices occupied by a porous ground substance (Figs. 1,2). The PM overlying the blastodisc is preferentially hydrolyzed in vitro by cock sperm (1) or by partially purified cock sperm acrosin (2). With either agent the PM overlying the remainder of the ovum requires longer incubation times for hydrolysis.Transmission electron microscopy of blastodisc and non-blastodisc regions of ova removed from the body cavity immediately after ovulation and incubated with sperm in modified Krebs-Ringer solution for 10-15 min. clearly demonstrates this breakdown.
Sem/X-Ray Applications to the Forensic Science Field
Authors: Culbreth K. 
Published: June 2020

The introduction of scanning electron microscopy and energy dispersive x-ray analysis to forensic science has provided additional methods by which investigative evidence can be analyzed. The importance of evidence from the scene of a crime or from the personal belongings of a victim and suspect has resulted in the development and evaluation of SEM/x-ray analysis applications to various types of forensic evidence. The intent of this paper is to describe some of these applications and to relate their importance to the investigation of criminal cases.The depth of field and high resolution of the SEM are an asset to the evaluation of evidence with respect to surface phenomena and physical matches (1). Fig. 1 shows a Phillips screw which has been reconstructed after the head and shank were separated during a hit-and-run accident.
In-Situ Investigation of Fatigue Deformation by Sem Methods
Authors: Weiss B. , Stickler R. 
Published: June 2020

The damage which accumulates during cyclic deformation of metals and alloys is characterized by internal dislocation reactions and by the formation of “persistant slip bands” in surface near regions. The latter are thought to contribute to the nucleation of microcracks which propagate and finally lead to fatigue failure.The determination of the microstructural and topographical changes occuring progressively during fatigue exposure is of considerable scientific and technical interest. A detailed investigation of the kinetics of these changes requires in-situ examination which are best carried out with a SEM due to the large depth of focus, the wide magnification range, and the possibilities of electronic signal processing and video recording.
Scanning Electron Microscopy of Carburized Thoriated-Tungsten Directemitting Cathodes
Authors: Amy J. A. , Alcorn R. A. , Phillips B. F. 
Published: June 2020

Distributions of elements in carburized W-1% Th02 wires from cathodes of high-power electron tubes after 10 and 3500 hr operation have been determined by ion microscopy (1); some microstructural features of such wires are reported here.Carburization of the wires examined had taken place to a depth of about one-eighth their 10-mil diameter (Figure 1). Longitudinal cracks with short circumferential excursions appear to be common in these wires, although this Figure shows an unusually bad case. Die marks from wiredrawing were also evident on all wires.At their outer ends the cracks had the same surface hillocks as the emissive surfaces (Figure 2), suggesting that they may have existed before carburization began. At their roots, some cracks showed smooth fracture surfaces (Figure 3), suggesting that crack extension might have occurred later: as the carburized layer becomes thicker, the outermost portions are placed under ever-increasing tensile loading because of the volume increase on passing from metal to carbide.
Scanning Electron Microscopy in Hybrid Microelectronics
Authors: Khadpe S. , Faryniak R. 
Published: June 2020

The Scanning Electron Microscope (SEM) is an important tool in Thick Film Hybrid Microcircuits Manufacturing because of its large depth of focus and three dimensional capability. This paper discusses some of the important areas in which the SEM is used to monitor process control and component failure modes during the various stages of manufacture of a typical hybrid microcircuit.Figure 1 shows a thick film hybrid microcircuit used in a Motorola Paging Receiver. The circuit consists of thick film resistors and conductors screened and fired on a ceramic (aluminum oxide) substrate. Two integrated circuit dice are bonded to the conductors by means of conductive epoxy and electrical connections from each integrated circuit to the substrate are made by ultrasonically bonding 1 mil aluminum wires from the die pads to appropriate conductor pads on the substrate. In addition to the integrated circuits and the resistors, the circuit includes seven chip capacitors soldered onto the substrate. Some of the important considerations involved in the selection and reliability aspects of the hybrid circuit components are: (a) the quality of the substrate; (b) the surface structure of the thick film conductors; (c) the metallization characteristics of the integrated circuit; and (d) the quality of the wire bond interconnections.
Simulation of three Dimensional Defect Images in Transmission Electron Microscopy
Authors: Cooper W. D. , Hartley C. S. , Hren J. J. 
Published: June 2020

Interpretation of electron microscope images of crystalline lattice defects can be greatly aided by computer simulation of theoretical contrast from continuum models of such defects in thin foils. Several computer programs exist at the present time, but none are sufficiently general to permit their use as an aid in the identification of the range of defect types encountered in electron microscopy. This paper presents progress in the development of a more general computer program for this purpose which eliminates a number of restrictions contained in other programs. In particular, the program permits a variety of foil geometries and defect types to be simulated.The conventional approximation of non-interacting columns is employed for evaluation of the two-beam dynamical scattering equations by a piecewise solution of the Howie-Whelan equations.