Memory disc defect characterization using SEM and energy-dispersive x-ray analysis

1983 ◽  
Vol 41 ◽  
pp. 172-173
Author(s):  
R. A. Bass ◽  
A. S. Brar
Keyword(s):  
Packing Density ◽  
Energy Dispersive ◽  
Defect Characterization ◽  
Media Processing ◽  
X Ray ◽  
Storage Devices ◽  
The Past ◽  
The Media ◽  
High Track

In this era of computers, users of storage devices are requesting increased quantities of storage while maintaining or reducing the size of the package. This has meant a reduction in the size of a data bit and increased the susceptability of the media to microscopic defects, which occur in many shapes and sizes and at all stages of media processing. These processes are the machining of the raw substrates, coating the substrates, polishing the media and assembling the media in modules.In the past many of these defects could be overlooked since they didn't introduce missing bits in the read write process. The reason for this was the fact that the recording did not require a high track per inch or bit per inch packing density. Since all media specifications include requirements dealing with the quantity of missing bits or extra bit errors and their sizes; a study of media defects was implemented and the results are presented in this paper.

A New Instrument for the Energy Dispersive X-Ray Fluorescence Analysis of Objects of Art and Archaeology

1991 ◽  
Vol 35 (B) ◽  
pp. 1157-1163 ◽  
Author(s):  
Manfred Schreiner ◽  
Michael Mantler ◽  
Franz Weber ◽  
Richard Ebner ◽  
Franz Mairinger
Keyword(s):  
Geographic Origin ◽  
Fluorescence Analysis ◽  
Energy Dispersive ◽  
X Ray ◽  
The Past ◽  
Material Analysis ◽  
New Instrument ◽  
Art Historians

Objects of art and archaeology are relicts of the past, and art historians, archaeologists and conservators are constantly concerned with the questions of where, when or by whom such artifacts were made. Usually stylistic considerations can provide answers to these questions, but as styles were sometimes copied at locations and times quite different from those for which they were most characteristic, material analysis is often essential when one is attempting to infer how and of what materials an object was made. The use of several compounds e.g. as pigments in paintings, or the deliberate alloying of Cu with Sn, As, Sb and Pb, has varied greatly from region to region and from time to time and can be used to infer the geographic origin of an object or at least the origin of the materials, out of which it was made.

Do Ultra-Thin Polymer X-Ray Windows Leak Water Vapor?

1999 ◽  
Vol 5 (S2) ◽  
pp. 588-589
Author(s):  
A. Nielson ◽  
J. Thorne
Keyword(s):  
Water Vapor ◽  
Thin Layer ◽  
Liquid Nitrogen ◽  
Energy Dispersive Spectroscopy ◽  
Light Element ◽  
Energy Dispersive ◽  
Nitrogen Form ◽  
X Ray ◽  
The Past ◽  
Thin Polymer

Ultra-thin polymer x-ray windows have been developed for energy dispersive spectroscopy (EDS) that enable analysis of the elements lighter in mass than sodium while protecting the detector from light and gases. Windowless detectors produce the ultimate in detector sensitivity, however that sensitivity is lost when ice and other contaminants form on the detector. Polymer windows have had a problem with icing in the past, however modern ultra-thin polymer windows contain metalized layers to prevent the diffusion of water. Nevertheless, over the course of time it has been observed that some detectors with polymer windows that are kept continually cool with liquid nitrogen form a thin layer of ice that attenuates light element sensitivity. The source of this water has been hypothesized to be a gradual leak of water vapor through the polymer x-ray window. This hypothesis has been questioned on the basis that the windows were helium leak tight to 1 x 10−9 mbar L/sec and helium is a smaller molecule than water.

scholarly journals Corpus Asher-Greve. Dealing with "Data form the Past"

2020 ◽  
Vol 2 ◽  
Author(s):  
Nicole Gäumann
Keyword(s):  
Chemical Composition ◽  
Mineralogical Composition ◽  
Energy Dispersive ◽  
X Ray Diffraction ◽  
X Ray ◽  
Archaeological Data ◽  
The Past ◽  
Data Form ◽  
Powder Samples ◽  
Cylinder Seals

SNF-Project (1.722-0.83): Naturwissenschaftliche und typologische Untersuchungen an Rollsiegeln. When?         1983-1986 Who?           Dr. Julia Asher-Greve and Prof. Dr. Willem Stern, University of Basel Material?     1017 cylinder seals from Mesopotamia and neighbouring regions covering all periods from Uruk to Achaemenid period. What? XRD (X-ray diffraction) -> mineralogical composition EDXRF (energy dispersive X-ray fluorescence) -> chemical composition Iconographical typology Project couldn’t be brought to an end, data not interpreted   PhD-Project based on the corpus and analyses of the project Asher-Greve When?         2017-2020 (?) Who?           Nicole Gäumann Material?     Same What? Interpretation of XRD- and EDXRF from previous project Further analyses on existing powder samples (?) Typology Bringing together the results of the material analyses and the archaeological data, the material ought to be interpreted in terms of connections between material, colour, dating, provenance, theme, owner…  

scholarly journals Grigoriev institute for medical radiology and oncology centenary: historic events

2020 ◽  
Vol 28 (3) ◽  
pp. 308-325
Author(s):  
M.V. Krasnoselskyi ◽  
N.O. Artamonova
Keyword(s):  
Data Storage ◽  
Scientific Literature ◽  
Medical Science ◽  
Medical Sciences ◽  
X Ray ◽  
Storage Devices ◽  
The Past ◽  
A Chain ◽  
Medical Radiology ◽  
To Receive

Background. The historical survey of the activities carried out at Grigoriev Institute for Medical Radiology and Oncology is of present interest, resulting from the need to structure the Institute development trends in terms of a centenary celebration. Providing insight to visions of the past, one can also apprehend historical events, personalities and phenomena. Purpose – to summarize historical findings on establishing and development of SO «Grigoriev Institute for Medical Radiology and Oncology of the National Academy of Medical Sciences of Ukraine». Materials. The study deals with analyzing historical scientific literature, manuscripts, archive paper records, data on electronic data storage devices and other carriers that reveal the historical aspects of forming X-ray Radiography, Radiology and Oncology in Ukraine, particularly in Kharkiv. Results and discussion. For a century of the existence of the Institute, the scientists of several generations have come a long way in forming and developing X-ray Radiography, Radiation Therapy, Diagnostic Radiology, Oncology, Radiobiology, Radiation Dosimetry and others. They were the first to receive radium for the country alongside with establishing oncology dispensaries, X-ray technical school and setting up a chain of remote research and support stations (13 radiology and 26 oncology ones). These days, the team of the Institute are going out of their way to further develop science and medicine to the benefit of human health. Conclusions. One hundred years ago, the first step in developing Oncology and Radiology initiated forming a new scientific community of experts, who contributed a lot to the formation of some frontmost medical science along with non-stop promoting efficacious scientific and theoretical evolvement of those.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

RNA polymerase: Preparation and structural analysis of helical polymers

1984 ◽  
Vol 42 ◽  
pp. 152-153
Author(s):  
E. Loren Buhle ◽  
Pamela Rew ◽  
Ueli Aebi
Keyword(s):  
Structural Analysis ◽  
Rna Polymerase ◽  
Molecular Level ◽  
X Ray Diffraction ◽  
Helical Polymers ◽  
X Ray ◽  
E Coli ◽  
The Past ◽  
Ordered Arrays ◽  
Low Ionic Strength

While DNA-dependent RNA polymerase represents one of the key enzymes involved in transcription and ultimately in gene expression in procaryotic and eucaryotic cells, little progress has been made towards elucidation of its 3-D structure at the molecular level over the past few years. This is mainly because to date no 3-D crystals suitable for X-ray diffraction analysis have been obtained with this rather large (MW ~500 kd) multi-subunit (α2ββ'ζ). As an alternative, we have been trying to form ordered arrays of RNA polymerase from E. coli suitable for structural analysis in the electron microscope combined with image processing. Here we report about helical polymers induced from holoenzyme (α2ββ'ζ) at low ionic strength with 5-7 mM MnCl2 (see Fig. 1a). The presence of the ζ-subunit (MW 86 kd) is required to form these polymers, since the core enzyme (α2ββ') does fail to assemble into such structures under these conditions.

Microanalysis of precipitates in a ferritic steel

1978 ◽  
Vol 36 (1) ◽  
pp. 618-619
Author(s):  
J.M. Titchmarsh
Keyword(s):  
Ferritic Steel ◽  
Particle Identification ◽  
Energy Dispersive ◽  
Objective Lens ◽  
Ferritic Steels ◽  
Replica Technique ◽  
X Ray ◽  
Large Numbers ◽  
Scanning Transmission ◽  
Made In

The advances in recent years in the microanalytical capabilities of conventional TEM's fitted with probe forming lenses allow much more detailed investigations to be made of the microstructures of complex alloys, such as ferritic steels, than have been possible previously. In particular, the identification of individual precipitate particles with dimensions of a few tens of nanometers in alloys containing high densities of several chemically and crystallographically different precipitate types is feasible. The aim of the investigation described in this paper was to establish a method which allowed individual particle identification to be made in a few seconds so that large numbers of particles could be examined in a few hours.A Philips EM400 microscope, fitted with the scanning transmission (STEM) objective lens pole-pieces and an EDAX energy dispersive X-ray analyser, was used at 120 kV with a thermal W hairpin filament. The precipitates examined were extracted using a standard C replica technique from specimens of a 2¼Cr-lMo ferritic steel in a quenched and tempered condition.

Energy Dispersive X-Ray Measurements of thin Metal Foils

1976 ◽  
Vol 34 ◽  
pp. 426-427
Author(s):  
J. Bentley ◽  
E. A. Kenik
Keyword(s):  
Materials Science ◽  
Energy Dispersive Spectrometer ◽  
Thin Foil ◽  
Thin Metal ◽  
Energy Dispersive ◽  
Thin Specimen ◽  
X Ray ◽  
Metal Foils ◽  
Small Probe ◽  
Scanning Transmission

Instruments combining a 100 kV transmission electron microscope (TEM) with scanning transmission (STEM), secondary electron (SEM) and x-ray energy dispersive spectrometer (EDS) attachments to give analytical capabilities are becoming increasingly available and useful. Some typical applications in the field of materials science which make use of the small probe size and thin specimen geometry are the chemical analysis of small precipitates contained within a thin foil and the measurement of chemical concentration profiles near microstructural features such as grain boundaries, point defect clusters, dislocations, or precipitates. Quantitative x-ray analysis of bulk samples using EDS on a conventional SEM is reasonably well established, but much less work has been performed on thin metal foils using the higher accelerating voltages available in TEM based instruments.

Preparation And elemental analysis of ancient fibers

1987 ◽  
Vol 45 ◽  
pp. 410-411
Author(s):  
Allen Angel ◽  
Kathryn A. Jakes
Keyword(s):  
Cross Sections ◽  
Physical Structure ◽  
Energy Dispersive ◽  
Archaeological Sites ◽  
X Ray ◽  
Long Term Storage ◽  
Backscattered Electron ◽  
Electron Imaging

Fabrics recovered from archaeological sites often are so badly degraded that fiber identification based on physical morphology is difficult. Although diagenetic changes may be viewed as destructive to factors necessary for the discernment of fiber information, changes occurring during any stage of a fiber's lifetime leave a record within the fiber's chemical and physical structure. These alterations may offer valuable clues to understanding the conditions of the fiber's growth, fiber preparation and fabric processing technology and conditions of burial or long term storage (1).Energy dispersive spectrometry has been reported to be suitable for determination of mordant treatment on historic fibers (2,3) and has been used to characterize metal wrapping of combination yarns (4,5). In this study, a technique is developed which provides fractured cross sections of fibers for x-ray analysis and elemental mapping. In addition, backscattered electron imaging (BSI) and energy dispersive x-ray microanalysis (EDS) are utilized to correlate elements to their distribution in fibers.

PHAX-SCAN: Functional integration of a Scanning Electron Microscope and an energy-dispersive x-ray analyser

1989 ◽  
Vol 47 ◽  
pp. 56-57
Author(s):  
Marc H. Peeters ◽  
Max T. Otten
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
High Speed ◽  
High Performance ◽  
Functional Integration ◽  
Energy Dispersive ◽  
X Rays ◽  
X Ray ◽  
High Speed Analysis ◽  
Scanning Electron

Over the past decades, the combination of energy-dispersive analysis of X-rays and scanning electron microscopy has proved to be a powerful tool for fast and reliable elemental characterization of a large variety of specimens. The technique has evolved rapidly from a purely qualitative characterization method to a reliable quantitative way of analysis. In the last 5 years, an increasing need for automation is observed, whereby energy-dispersive analysers control the beam and stage movement of the scanning electron microscope in order to collect digital X-ray images and perform unattended point analysis over multiple locations.The Philips High-speed Analysis of X-rays system (PHAX-Scan) makes use of the high performance dual-processor structure of the EDAX PV9900 analyser and the databus structure of the Philips series 500 scanning electron microscope to provide a highly automated, user-friendly and extremely fast microanalysis system. The software that runs on the hardware described above was specifically designed to provide the ultimate attainable speed on the system.

Sign in / Sign up

Export Citation Format

Share Document