Electron Microscope Characterization of Pulse Annealed Semiconductors

1980 ◽  
Vol 2 ◽  
Author(s):  
A. G. CULLIS
Keyword(s):  
Electron Microscopy ◽  
Defect Structure ◽  
Device Fabrication ◽  
Fabrication Technology ◽  
The Past ◽  
Semiconductor Structures ◽  
Pulse Processing ◽  
Processing Techniques

ABSTRACTThe pulse processing techniques that have assumed prominence over the past few years offer various important advantages for device fabrication technology. However, the usefulness of each individual method depends substantially upon the specific annealing mechanism involved. This article demonstrates the role of electron microscopy in elucidating such mechanisms and in analysing annealed semiconductor structures of importance to both research workers and semiconductor technologists. The range of laser and electron beam pulse annealing methods is covered and defect structure transitions observed are related to the solid and liquid phase processes occurring. Characteristic impurity trapping and segregation phenomena are described.

On Future Directions in Pathology

1982 ◽  
Vol 40 ◽  
pp. 274-277
Author(s):  
Benjamin F. Trump ◽  
Irene K. Berezesky ◽  
Raymond T. Jones
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Clinical Pathology ◽  
Future Directions ◽  
Diagnostic Pathology ◽  
The Past ◽  
Transmission Electron ◽  
Organ Systems ◽  
The Many

The role of electron microscopy and associated techniques is assured in diagnostic pathology. At the present time, most of the progress has been made on tissues examined by transmission electron microscopy (TEM) and correlated with light microscopy (LM) and by cytochemistry using both plastic and paraffin-embedded materials. As mentioned elsewhere in this symposium, this has revolutionized many fields of pathology including diagnostic, anatomic and clinical pathology. It began with the kidney; however, it has now been extended to most other organ systems and to tumor diagnosis in general. The results of the past few years tend to indicate the future directions and needs of this expanding field. Now, in addition to routine EM, pathologists have access to the many newly developed methods and instruments mentioned below which should aid considerably not only in diagnostic pathology but in investigative pathology as well.

IVUS Image Processing Methodologies

2013 ◽  
pp. 639-657
Author(s):  
Antonis A. Sakellarios ◽  
Christos V. Bourantas ◽  
Lambros S. Athanasiou ◽  
Dimitrios I. Fotiadis ◽  
Lampros K. Michalis
Keyword(s):  
Image Processing ◽  
Vessel Wall ◽  
Regions Of Interest ◽  
Manual Segmentation ◽  
Arterial Lumen ◽  
Ivus Image ◽  
Processing Techniques ◽  
Automated Methods

Intravascular Ultrasound (IVUS) is an invasive imaging technique that allows detailed visualization of the arterial lumen and outer vessel wall and permits characterization of the type of the plaque and quantification of its burden. Traditionally IVUS processing was performed manually. However, it became apparent that manual segmentation is time consuming, and the obtained results depend on the experience of the operators. To overcome these limitations and enhance the role of IVUS in clinical practice and research, several (semi-) automated methods have been developed that expedite detection of the regions of interest and/or characterization of the type of the plaque. In this chapter we review the available IVUS processing techniques and present the developed commercial solutions for IVUS segmentation and plaque characterization.

Electron Microscopy of Mesoscale Arrays of Quantum-Confined CdS Nanoparticles Formed on DNA Templates

1996 ◽  
Vol 452 ◽  
Author(s):  
Russell F. Pinizzotto ◽  
Young G. Rho ◽  
Yandong Chen ◽  
Robert M. Pirtle ◽  
Irma L. Pirtle ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Quantum Confinement ◽  
Cds Nanoparticles ◽  
Dna Templates ◽  
Quantum Confinement Effects ◽  
Transmission Electron ◽  
Quantum Confined ◽  
Processing Techniques ◽  
State Processing

AbstractThis paper describes the fabrication method and initial characterization of self-assembled mesoscale arrays of quantum-confined CdS nanoparticles using DNA as a template for the overall shape. Three DNAs were used: the circular and linear forms of the plasmid pUCLeu4, and circular φ×174 RF II. In all three cases, the mesoscale lengths are consistent with the A-form of DNA. The structural signatures and crystallography were confirmed using conventional and high resolution transmission electron microscopy, and electron diffraction. Optical spectroscopy demonstrated that the particles display quantum-confinement effects. This research is a fundamental demonstration of the power of combining biochemical and solid-state processing techniques.

scholarly journals Continuing the debate on the role of Quaternary environmental change for macroevolution

2004 ◽  
Vol 359 (1442) ◽  
pp. 295-303 ◽  
Author(s):  
K. D. Bennett
Keyword(s):  
Environmental Change ◽  
Time Scales ◽  
Causal Factors ◽  
Species Response ◽  
The Past ◽  
Dna Characterization ◽  
Evolutionary Consequences ◽  
Response To Environmental Change

The Quaternary has been a period of dramatic environmental change for the past 1.8 Myr, with major shifts in distributions and abundances of terrestrial and marine organisms. The evolutionary consequences of this have been debated since the nineteenth century. However, the lack of accurate relative and absolute time–scales for evolutions and environmental change inhibited progress. We do now have an understanding of time–scales. Palaeoecology has demonstrated the individualistic nature of species' response to environmental change, but lacks a means of determining ancestry. DNA characterization of modern populations in relation to their distributions nicely complements palaeoecological results by contributing ancestry. The chance to understand how species originate and the causal factors of speciation (environmental change or otherwise) may be within reach.

scholarly journals Roles, Responsibilities, and Needs of Institutional GME Leaders: A Multinational Characterization of Designated Institutional Officials

2019 ◽  
Vol 11 (4s) ◽  
pp. 110-117 ◽  
Author(s):  
Sawsan Abdel-Razig ◽  
Halah Ibrahim
Keyword(s):  
Professional Development ◽  
Medical Education ◽  
Middle East ◽  
Best Practices ◽  
Job Descriptions ◽  
The Past ◽  
Professional Development Needs ◽  
Accredited Institutions

ABSTRACT Background Since 2012, several academic centers in the Middle East have attained accreditation by the Accreditation Council for Graduate Medical Education International (ACGME-I). An emerging group of GME leaders have assumed the role of designated institutional official (DIO), leading their institutions to accreditation. Despite these DIOs' key positions in driving GME reform, there is a lack of published studies on the roles, responsibilities, and needs of DIOs in international settings. Objective We examined the characteristics, roles, responsibilities, and needs of DIOs in the Middle East. Methods A questionnaire was electronically distributed from December 2018 to February 2019 to all current and former DIOs in ACGME-I accredited institutions in the Middle East. Results Of 16 surveys sent, 11 (69%) were returned. All DIOs were physicians; the majority were women less than 55 years of age, and assumed the role of DIO in the past decade. Most DIOs felt prepared for the position and well supported by their institution and their program directors. All reported having additional roles beyond the DIO position. Most identified the most challenging aspect of their role related to GME budgets, training for their responsibilities, sharing best practices and documents such as DIO job descriptions and other key documents, and DIO training. Conclusions ACGME-I accreditation is a critical driver of efforts to define the DIO role. DIOs in the Middle East share common perceptions, experiences, and needs. Further research should identify professional development needs in an increasingly diverse international worldwide DIO community.

EBIC microscopy for the characterization of semiconductor materials and devices

1983 ◽  
Vol 41 ◽  
pp. 162-163
Author(s):  
C. J. Varker
Keyword(s):  
Electron Microscopy ◽  
Semiconductor Device ◽  
Minority Carrier Lifetime ◽  
Czochralski Method ◽  
Device Fabrication ◽  
Defect Complexes ◽  
Silicon Crystals ◽  
Oxygen Precipitation ◽  
The Relationship

For dislocation-free silicon crystals, defects generated during semiconductor device fabrication processes are often the end result of inhomogeneities formed during crystal growth. Impurity-point defect complexes are often transformed into a variety of microdefects during subsequent thermal processing. Extensive investigations have been published on the analysis of microdefects such as stacking faults, complex dislocation colonies and impurity precipitates in silicon crystals. For crystals grown with the Czochralski method, oxygen and carbon have been the subject of many recent investigations. Oxygen precipitation during thermal annealing has been identified as a dominant cause of minority carrier lifetime degradation. The investigative methods used in the majority of these studies include: transmission electro microscopy, scanning electron microscopy, I.R. absorption spectroscopy, X-ray transmission methods and chemical decoration etching.Conventional electron microscopy provides no direct information on the relationship between defects in crystals and electrical effects in semiconductor devices.

Progress in ultrastructural and molecular analysis of the nuclear matrix

1992 ◽  
Vol 50 (1) ◽  
pp. 508-509
Author(s):  
Edward G. Fey
Keyword(s):  
Electron Microscopy ◽  
Nuclear Matrix ◽  
Structure And Function ◽  
Matrix Proteins ◽  
Rna Transcription ◽  
Nuclear Matrix Proteins ◽  
The Past ◽  
And Function

In the past few years, considerable advances have been made regarding the structure and function of the nuclear matrix. In the first half of this presentation, the field of nuclear matrix research will be summarized. Emphasis will be placed on those studies where molecular interactions are demonstrated in situ utilizing high resolution light and/or electron microscopy. Studies demonstrating the role of the nuclear matrix in DNA synthesis and replication, RNA transcription and processing, and the binding of matrix attachment regions to specific nuclear matrix proteins will be summarized.

Microstructure Characterization of Ceramics by Fractal Geometry

1997 ◽  
Vol 492 ◽  
Author(s):  
Z. X. Xiong ◽  
K. Z. Baba-Kishi ◽  
F. G. Shin
Keyword(s):  
Electron Microscopy ◽  
Image Processing ◽  
Fractal Dimension ◽  
Fractal Geometry ◽  
Fractal Theory ◽  
Image Processing Techniques ◽  
Fractal Analyses ◽  
Processing Techniques ◽  
Good Agreement

ABSTRACTFollowing Mandelbrot's fractal theory, the irregular characteristics of the microstructural features of ferroelectric Pb(Sc0.5 Ta0.5)O3 ceramics, including grain boundaries and dislocation networks, were investigated. The microstructural features were imaged by electron microscopy. The fractal analyses were carried out manually and by image processing techniques, which show the value of the fractal dimension, D, varies according to the regularity of the microstructure. The value of, D, close to unity is an indication of an increasing degree of microstructural regularity, which is in good agreement with the simulated results.

Phycological studies in lakes Ontario, Erie, Huron, and Superior

1982 ◽  
Vol 60 (9) ◽  
pp. 1837-1858 ◽  
Author(s):  
M. Munawar ◽  
I. F. Munawar
Keyword(s):  
Species Composition ◽  
Great Lakes ◽  
Primary Concern ◽  
Carbon 14 ◽  
The Past ◽  
The Subject ◽  
Processing Techniques ◽  
Canadian Research

An indepth phycological comparison is presented for lakes Ontario, Erie, Huron, and Superior, based on extensive lake-wide surveys carried out during the past 12 years. This comparison was achieved by the application of standard and consistent identification, enumeration, and data-processing techniques. The resulting species composition data are voluminous and present a broad picture of the phytoplankton assemblage. Our data base has enabled us to assess the long-term floristic changes, knowledge of which is lacking in the Great Lakes. The species composition reflects more or less the current trophic status of these lakes. The preponderance of nannoplankton and phytoflagellates is the subject of our current experimental research, which includes the fractionation of chlorophyll a and carbon-14 uptake, toxicity studies of heavy metals upon various size fractions of algae, and the role of microalgae and ultraplankton in the transfer of contaminants via zooplankton grazing. The need for phycological research in the Great Lakes is expanding with decreasing eutrophication and the increasing problems of contaminants. The recovery, rehabilitation, and preservation of these vital freshwaters are the primary concern of the continuing Canadian research program in the Great Lakes.

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