Light and Electron Microscope Approaches to Sequence of Writing Problems

2018 ◽  
Vol 28 ◽  
pp. 77-103
Author(s):  
Joseph G. Barabe ◽  
Wayne D. Niemeyer ◽  
Vickie Willard
Keyword(s):  
Electron Microscope ◽  
Analytical Techniques ◽  
Sponsored Research ◽  
Know How ◽  
Writing Problems ◽  
Wide Range ◽  
Practical Tool ◽  
Document Examiners

Sequence of writing problems constitute only a small percentage of most document examiners’ case loads, but solving such problems can be crucial. It is important to know the factors that make sequences capable of determination, and when possible, to know how to make such a determination or where to find further assistance. McCrone Associates, a microscopical and microanalytical consulting firm with a wide range of instrumentation and analytical techniques, is occasionally asked to supplement work performed by individual examiners in smaller laboratories. For this reason, McCrone sponsored research to ascertain which instruments, illumination methods, magnifications and techniques might provide more definitive answers to a variety of sequence of writing questions. We derived a number of insights from this research which we would like to present as a general microscopical theory of sequence determinability. It is hoped that this theory will provide the document examiner with one more practical tool with which to approach sequence of writing problems. We also invite our colleagues to test this theory and report both confirmations and discrepancies. Purchase Article - $10

Recent Applications of High Resolution Electron Microscopy to Crystalline Arrays of Virus Particles

1978 ◽  
Vol 36 (3) ◽  
pp. 470-482 ◽  
Author(s):  
R.W. Horne
Keyword(s):  
Electron Microscopy ◽  
Image Processing ◽  
Analytical Techniques ◽  
Staining Technique ◽  
High Resolution Electron Microscopy ◽  
Optical Diffraction ◽  
Full Potential ◽  
Virus Particles ◽  
Resolution Electron ◽  
Wide Range

The technique of surrounding virus particles with a neutralised electron dense stain was described at the Fourth International Congress on Electron Microscopy, Berlin 1958 (see Home & Brenner, 1960, p. 625). For many years the negative staining technique in one form or another, has been applied to a wide range of biological materials. However, the full potential of the method has only recently been explored following the development and applications of optical diffraction and computer image analytical techniques to electron micrographs (cf. De Hosier & Klug, 1968; Markham 1968; Crowther et al., 1970; Home & Markham, 1973; Klug & Berger, 1974; Crowther & Klug, 1975). These image processing procedures have allowed a more precise and quantitative approach to be made concerning the interpretation, measurement and reconstruction of repeating features in certain biological systems.

In-situ electrical-resistivity measurements in the high-voltage electron microscope

1978 ◽  
Vol 36 (1) ◽  
pp. 68-69
Author(s):  
W. E. King
Keyword(s):  
Electrical Resistivity ◽  
Electron Microscope ◽  
High Voltage ◽  
Resistivity Measurements ◽  
Voltage Electron ◽  
High Voltage Electron Microscope ◽  
High Voltage Electron ◽  
Wide Range ◽  
Helium Gas

A side-entry type, helium-temperature specimen stage that has the capability of in-situ electrical-resistivity measurements has been designed and developed for use in the AEI-EM7 1200-kV electron microscope at Argonne National Laboratory. The electrical-resistivity measurements complement the high-voltage electron microscope (HVEM) to yield a unique opportunity to investigate defect production in metals by electron irradiation over a wide range of defect concentrations.A flow cryostat that uses helium gas as a coolant is employed to attain and maintain any specified temperature between 10 and 300 K. The helium gas coolant eliminates the vibrations that arise from boiling liquid helium and the temperature instabilities due to alternating heat-transfer mechanisms in the two-phase temperature regime (4.215 K). Figure 1 shows a schematic view of the liquid/gaseous helium transfer system. A liquid-gas mixture can be used for fast cooldown. The cold tip of the transfer tube is inserted coincident with the tilt axis of the specimen stage, and the end of the coolant flow tube is positioned without contact within the heat exchanger of the copper specimen block (Fig. 2).

scholarly journals Overview of Popular Techniques of Raman Spectroscopy and Their Potential in the Study of Plant Tissues

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1537
Author(s):  
Aneta Saletnik ◽  
Bogdan Saletnik ◽  
Czesław Puchalski
Keyword(s):  
Raman Spectroscopy ◽  
Cell Walls ◽  
Structural Changes ◽  
Spatial Information ◽  
Technological Development ◽  
Analytical Techniques ◽  
High Sensitivity ◽  
Plant Tissues ◽  
Wide Range ◽  
Identification Technique

Raman spectroscopy is one of the main analytical techniques used in optical metrology. It is a vibration, marker-free technique that provides insight into the structure and composition of tissues and cells at the molecular level. Raman spectroscopy is an outstanding material identification technique. It provides spatial information of vibrations from complex biological samples which renders it a very accurate tool for the analysis of highly complex plant tissues. Raman spectra can be used as a fingerprint tool for a very wide range of compounds. Raman spectroscopy enables all the polymers that build the cell walls of plants to be tracked simultaneously; it facilitates the analysis of both the molecular composition and the molecular structure of cell walls. Due to its high sensitivity to even minute structural changes, this method is used for comparative tests. The introduction of new and improved Raman techniques by scientists as well as the constant technological development of the apparatus has resulted in an increased importance of Raman spectroscopy in the discovery and defining of tissues and the processes taking place in them.

Lateral skull base surgery: a complicated pursuit?

2007 ◽  
Vol 122 (3) ◽  
pp. 221-229
Author(s):  
V C Cousins
Keyword(s):  
Skull Base ◽  
Skull Base Surgery ◽  
Treatment Modalities ◽  
Published Data ◽  
Know How ◽  
Team Assessment ◽  
Pathological Conditions ◽  
Lateral Skull Base ◽  
Wide Range ◽  
Multi Disciplinary Team

AbstractThe management of lesions of the lateral skull base is a highly sophisticated branch of surgery generally performed by otolaryngology–head and neck surgeons as part of a multi-disciplinary team. Assessment of patients with diseases affecting the lateral skull base can be complex, as can the application of the various treatment modalities and the management of the expected and unexpected side effects of that treatment.A wide range of pathological conditions occur in the lateral skull base. Many operations and procedures have been described for dealing with them. There is not necessarily one correct solution to the management of any particular problem in the skull base, with multiple factors to be considered in planning and intervention.As surgeons, we need to know how our own results and outcomes compare with pooled, published data concerning the implications and complications occurring as a result of intervention, in order to better advise our patients on their management.

scholarly journals Optical tools for ocean monitoring and research

Ocean Science ◽  
2009 ◽  
Vol 5 (4) ◽  
pp. 661-684 ◽  
Author(s):  
C. Moore ◽  
A. Barnard ◽  
P. Fietzek ◽  
M. R. Lewis ◽  
H. M. Sosik ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Ocean Color ◽  
Analytical Techniques ◽  
Optical Measurements ◽  
Physical Parameters ◽  
Optical Tools ◽  
Wide Range ◽  
Radiance Distribution ◽  
Ocean Monitoring ◽  
Methane Carbon

Abstract. Requirements for understanding the relationships between ocean color and suspended and dissolved materials within the water column, and a rapidly emerging photonics and materials technology base for performing optical based analytical techniques have generated a diverse offering of commercial sensors and research prototypes that perform optical measurements in water. Through inversion, these tools are now being used to determine a diverse set of related biogeochemical and physical parameters. Techniques engaged include measurement of the solar radiance distribution, absorption, scattering, stimulated fluorescence, flow cytometry, and various spectroscopy methods. Selective membranes and other techniques for material isolation further enhance specificity, leading to sensors for measurement of dissolved oxygen, methane, carbon dioxide, common nutrients and a variety of other parameters. Scientists are using these measurements to infer information related to an increasing set of parameters and wide range of applications over relevant scales in space and time.

Kean Miltos: The Well-Known Iron Oxides of Antiquity

1997 ◽  
Vol 92 ◽  
pp. 359-371 ◽  
Author(s):  
E. Photos-Jones ◽  
A. Cottier ◽  
A. J. Hall ◽  
L. G. Mendoni
Keyword(s):  
Iron Oxides ◽  
Analytical Techniques ◽  
Field Work ◽  
Archaeological Record ◽  
The North ◽  
Naturally Occurring ◽  
Physico Chemical ◽  
Wide Range ◽  
Industrial Mineral

The island of Kea in the North Cyclades was well known in antiquity for its miltos, a naturally occurring red iron oxide valued for its colour and wide range of applications. By combining geological field work, physico-chemical analytical techniques, simulation (heating) experiments as well as simple laboratory tests, this paper describes the study of Kean iron oxides in an attempt to characterize this material which is still largely elusive in the archaeological record. The present work corroborates previous observations about the superior quality of some Kean iron oxides. Furthermore, it puts forward the hypothesis that miltos may have been considered an industrial mineral, and as such may have been used as an umbrella term for a variety of materials including mineralogically distinct purple as well as red iron oxides.

scholarly journals FEI Titan 80-300 TEM

2016 ◽  
Vol 2 ◽  
Author(s):  
Andreas Thust ◽  
Juri Barthel ◽  
Karsten Tillmann
Keyword(s):  
Electron Microscope ◽  
Solid State ◽  
Spherical Aberration ◽  
Atomic Scale ◽  
Atomic Resolution ◽  
Lens System ◽  
Stage Design ◽  
Precise Positioning ◽  
Transmission Electron ◽  
Wide Range

The FEI Titan 80-300 TEM is a high-resolution transmission electron microscope equipped with a field emission gun and a corrector for the spherical aberration (<em>C</em><sub>S</sub>) of the imaging lens system. The instrument is designed for the investigation of a wide range of solid state phenomena taking place on the atomic scale, which requires true atomic resolution capabilities. Under optimum optical settings of the image <em>C</em><sub>S</sub>-corrector (CEOS CETCOR) the point-resolution is extended up to the information limit of well below 100 pm with 200 keV and 300 keV electrons. A special piezo-stage design allows ultra-precise positioning of the specimen in all 3 dimensions. Digital images are acquired with a Gatan 2k x 2k slow-scan charged coupled device camera.

scholarly journals School-university partnerships: Lessons learned from 10 years of spectroscopy for teachers and post 16 students

2016 ◽  
pp. 72-76
Author(s):  
TG Harrison ◽  
AJ Shaw ◽  
KL Shallcross ◽  
SJ Williams ◽  
DE Shallcross
Keyword(s):  
Analytical Techniques ◽  
Lessons Learned ◽  
University Partnerships ◽  
Chemistry Students ◽  
Advantages And Disadvantages ◽  
Wide Range

Spectroscopy covers a wide range of analytical techniques, a small sub-set of which UK pre-university chemistry students are required to study. The expense of such equipment means that it is not available to the vast majority of schools whilst it is commonplace in university chemistry departments. This article discusses the evolution of the Bristol ChemLabS spectroscopy outreach activities. The advantages and disadvantages of this method of engagement for both the participants and the providers are discussed from 10 years of activity.

Functionalization of Graphene with O and S for Catalytic Degradation of Chlorophenols and Dyes

2021 ◽  
Vol 1019 ◽  
pp. 194-204
Author(s):  
S. Sudhaparimala ◽  
R. Usha
Keyword(s):  
Graphene Oxide ◽  
Organic Dyes ◽  
Analytical Techniques ◽  
Degradation Process ◽  
Experimental Conditions ◽  
Photocatalytic Application ◽  
Wide Range ◽  
Doped Graphene ◽  
The Given ◽  
Graphene Structures

Graphene, functionalized with the heteroatoms like nitrogen, oxygen and sulphur atoms has been well explored for a wide range of applications but only few reports are available on its adsorption and photocatalytic application in the degradation of chlorophenols and organic dyes. A simple and energy-efficient process to prepare graphene oxide and sulphur doped graphene oxide was developed. The micro structure and surface morphology were confirmed by the analytical techniques of Powder X-ray diffractogram (PXRD), Fourier Transformed Raman Spectroscopy (FT-Raman), Scanning Electron Microscopy. The results were suggestive of the structures suitable for screening their catalytic activity in the degradation of the highly toxic polychlorophenols and organic dyes. The adsorption and photo catalytic properties of the asprepared samples were screened for the degradation process and it was found that sulphur doped graphene oxide showed more positive results for the degradation of chlorophenols than graphene oxide. Under the given experimental conditions the decoloration of dyes were not satisfactory. Ultimately, the study provided an economical and efficient, method for tuning graphene structures for the removal of pollutants in wastewater.

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