scholarly journals Supplementary material to "Quantification of Isomer-Resolved Iodide CIMS Sensitivity and Uncertainty Using a Voltage Scanning Approach"

2021 ◽  
Author(s):  
Chenyang Bi ◽  
Jordan E. Krechmer ◽  
Graham O. Frazier ◽  
Wen Xu ◽  
Andrew T. Lambe ◽  
...  
Keyword(s):  
Supplementary Material ◽  
Voltage Scanning

High-Voltage Scanning Electron Microscopy

1970 ◽  
Vol 28 ◽  
pp. 6-7
Author(s):  
J. M. Cowley
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Scanning Transmission Electron Microscopy ◽  
Wave Optics ◽  
Contrast Effects ◽  
Transmission Electron ◽  
Mode Of Operation ◽  
Scanning Transmission ◽  
Types Of Information ◽  
Voltage Scanning

The comparison of scanning transmission electron microscopy (STEM) with conventional transmission electron microscopy (CTEM) can best be made by means of the Reciprocity Theorem of wave optics. In Fig. 1 the intensity measured at a point A’ in the CTEM image due to emission from a point B’ in the electron source is equated to the intensity at a point of the detector, B, due to emission from a point A In the source In the STEM. On this basis it can be demonstrated that contrast effects In the two types of instrument will be similar. The reciprocity relationship can be carried further to include the Instrument design and experimental procedures required to obtain particular types of information. For any. mode of operation providing particular information with one type of microscope, the analagous type of operation giving the same information can be postulated for the other type of microscope. Then the choice between the two types of instrument depends on the practical convenience for obtaining the required Information.

Processing of human melanoma cells for correlative TEM, LVSEM, and LM

1991 ◽  
Vol 49 ◽  
pp. 106-107
Author(s):  
Marek Malecki ◽  
J. Victor Small ◽  
James Pawley
Keyword(s):  
Electron Microscopy ◽  
Low Voltage ◽  
Fluorescent Microscopy ◽  
Blood Stream ◽  
Surface Topology ◽  
Integrin Receptors ◽  
Transmission Electron ◽  
Develop Technology ◽  
Voltage Scanning ◽  
Mechanisms Of Adhesion

The relative roles of adhesion and locomotion in malignancy have yet to be clearly established. In a tumor, subpopulations of cells may be recognized according to their capacity to invade neighbouring tissue,or to enter the blood stream and metastasize. The mechanisms of adhesion and locomotion are themselves tightly linked to the cytoskeletal apparatus and cell surface topology, including expression of integrin receptors. In our studies on melanomas with Fluorescent Microscopy (FM) and Cell Sorter(FACS), we noticed that cells in cultures derived from metastases had more numerous actin bundles, then cells from primary foci. Following this track, we attempted to develop technology allowing to compare ultrastructure of these cells using correlative Transmission Electron Microscopy(TEM) and Low Voltage Scanning Electron Microscopy(LVSEM).

High-pressure freezing of cells in suspension for low-voltage scanning electron microscopy (LVSEM)

1991 ◽  
Vol 49 ◽  
pp. 64-65
Author(s):  
Marek Malecki ◽  
James Pawley ◽  
Hans Ris
Keyword(s):  
Electron Microscopy ◽  
High Pressure ◽  
Low Voltage ◽  
Culture Media ◽  
Cell Structure ◽  
Freeze Substitution ◽  
Ice Crystal ◽  
High Pressure Freezing ◽  
Cell Culture Media ◽  
Voltage Scanning

The ultrastructure of cells suspended in physiological fluids or cell culture media can only be studied if the living processes are stopped while the cells remain in suspension. Attachment of living cells to carrier surfaces to facilitate further processing for electron microscopy produces a rapid reorganization of cell structure eradicating most traces of the structures present when the cells were in suspension. The structure of cells in suspension can be immobilized by either chemical fixation or, much faster, by rapid freezing (cryo-immobilization). The fixation speed is particularly important in studies of cell surface reorganization over time. High pressure freezing provides conditions where specimens up to 500μm thick can be frozen in milliseconds without ice crystal damage. This volume is sufficient for cells to remain in suspension until frozen. However, special procedures are needed to assure that the unattached cells are not lost during subsequent processing for LVSEM or HVEM using freeze-substitution or freeze drying. We recently developed such a procedure.

Magnetic Domain Observation of an Amorphous Fe-Si-B Ribbon by Means of a High Voltage Scanning Electron Microscope

1981 ◽  
Vol 39 ◽  
pp. 320-321
Author(s):  
K. Tsuno ◽  
Y. Harada ◽  
T. Sato
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
High Voltage ◽  
Amorphous Ribbon ◽  
Image Resolution ◽  
Objective Lens ◽  
Magnetic Domains ◽  
Scattered Electron ◽  
Voltage Scanning ◽  
Scanning Electron

Magnetic domains of ferromagnetic amorphous ribbon have been observed using Bitter powder method. However, the domains of amorphous ribbon are very complicated and the surface of ribbon is not flat, so that clear domain image has not been obtained. It has been desired to observe more clear image in order to analyze the domain structure of this zero magnetocrystalline anisotropy material. So, we tried to observe magnetic domains by means of a back-scattered electron mode of high voltage scanning electron microscope (HVSEM).HVSEM method has several advantages compared with the ordinary methods for observing domains: (1) high contrast (0.9, 1.5 and 5% at 50, 100 and 200 kV) (2) high penetration depth of electrons (0.2, 1.5 and 8 μm at 50, 100 and 200 kV). However, image resolution of previous HVSEM was quite low (maximum magnification was less than 100x), because the objective lens cannot be excited for avoiding the application of magnetic field on the specimen.

In situ observations of electromigration induced void behavior

1995 ◽  
Vol 53 ◽  
pp. 244-245
Author(s):  
T. Marieb ◽  
J. C. Bravman ◽  
P. Flinn ◽  
D. Gardner ◽  
M. Madden
Keyword(s):  
Electron Microscopy ◽  
Void Nucleation ◽  
Plan View ◽  
Transmission Electron ◽  
Nucleation Sites ◽  
Microelectronics Industry ◽  
In Situ Observations ◽  
Backscatter Electron Detector ◽  
Voltage Scanning

Electromigration and stress voiding have been active areas of research in the microelectronics industry for many years. While accelerated testing of these phenomena has been performed for the last 25 years[1-2], only recently has the introduction of high voltage scanning electron microscopy (HVSEM) made possible in situ testing of realistic, passivated, full thickness samples at high resolution.With a combination of in situ HVSEM and post-testing transmission electron microscopy (TEM) , electromigration void nucleation sites in both normal polycrystalline and near-bamboo pure Al were investigated. The effect of the microstructure of the lines on the void motion was also studied.The HVSEM used was a slightly modified JEOL 1200 EX II scanning TEM with a backscatter electron detector placed above the sample[3]. To observe electromigration in situ the sample was heated and the line had current supplied to it to accelerate the voiding process. After testing lines were prepared for TEM by employing the plan-view wedge technique [6].

Actin filaments in two spermatozoa of crustacea decapoda

1990 ◽  
Vol 48 (3) ◽  
pp. 70-71
Author(s):  
E. Dupré ◽  
G. Schatten
Keyword(s):  
Electron Microscopy ◽  
Actin Filaments ◽  
Low Voltage ◽  
Active Role ◽  
Main Body ◽  
Robinson Crusoe ◽  
Decapod Crustaceans ◽  
Actual Participation ◽  
Voltage Scanning ◽  
Scanning Electron

Sperm of decapod crustaceans are formed by a round or cup-shaped body, a complex acrosome and one a few appendages emerging from the main body. Although this sperm does not have motility, it has some components of the cytoskeleton like microtubules, which are found inside the appendages. Actin filaments have been found in the spike of penaeidae sperms. The actual participation of the crustacean decapod sperm cytoskeleton during fertilization is not well understood. Actin is supposed to play an active role in drawing the penaeidae shrimp sperm closer to the egg after bending of the spike. The present study was aimed at the localization of actin filaments in sperm of the Robinson Crusoe island lobster, Jasus frontalis and in the crayfish Orconectes propincus, by fluorescent probes and low voltage scanning electron microscopy.

Recent developments in low-voltage SEM of polymers

1993 ◽  
Vol 51 ◽  
pp. 866-867
Author(s):  
S.J. Krause ◽  
W.W. Adams
Keyword(s):  
Low Voltage ◽  
Chromatic Aberration ◽  
Thermal Electron ◽  
Analytical Technique ◽  
Recent Developments ◽  
Beam Currents ◽  
New Generation ◽  
First Time ◽  
Voltage Scanning ◽  
Beam Damage

Over the past decade low voltage scanning electron microscopy (LVSEM) of polymers has evolved from an interesting curiosity to a powerful analytical technique. This development has been driven by improved instrumentation and in particular, reliable field emission gun (FEG) SEMs. The usefulness of LVSEM has also grown because of an improved theoretical and experimental understanding of sample-beam interactions and by advances in sample preparation and operating techniques. This paper will review progress in polymer LVSEM and present recent results and developments in the field.In the early 1980s a new generation of SEMs produced beam currents that were sufficient to allow imaging at low voltages from 5keV to 0.5 keV. Thus, for the first time, it became possible to routinely image uncoated polymers at voltages below their negative charging threshold, the "second crossover", E2 (Fig. 1). LVSEM also improved contrast and reduced beam damage in sputter metal coated polymers. Unfortunately, resolution was limited to a few tenths of a micron due to the low brightness and chromatic aberration of thermal electron emission sources.

Low-voltage field-emission SEM of polymeric membranes for glucose biosensors

1990 ◽  
Vol 48 (3) ◽  
pp. 860-861
Author(s):  
Lorna K. Mayo ◽  
Kenneth C. Moore ◽  
Mark A. Arnold
Keyword(s):  
Glucose Sensor ◽  
Low Voltage ◽  
Glucose Sensors ◽  
Polymeric Membranes ◽  
Artificial Endocrine Pancreas ◽  
Self Monitoring ◽  
Conducting Materials ◽  
Insulin Dependent ◽  
Living Tissues ◽  
Voltage Scanning

An implantable artificial endocrine pancreas consisting of a glucose sensor and a closed-loop insulin delivery system could potentially replace the need for glucose self-monitoring and regulation among insulin dependent diabetics. Achieving such a break through largely depends on the development of an appropriate, biocompatible membrane for the sensor. Biocompatibility is crucial since changes in the glucose sensors membrane resulting from attack by orinter action with living tissues can interfere with sensor reliability and accuracy. If such interactions can be understood, however, compensations can be made for their effects. Current polymer technology offers several possible membranes that meet the unique chemical dynamics required of a glucose sensor. Two of the most promising polymer membranes are polytetrafluoroethylene (PTFE) and silicone (Si). Low-voltage scanning electron microscopy, which is an excellent technique for characterizing a variety of polymeric and non-conducting materials, 27 was applied to the examination of experimental sensor membranes.

Novel Approaches to Low-Voltage Scanning Electron Microscopy

1990 ◽  
Vol 48 (1) ◽  
pp. 366-367
Author(s):  
Arthur V. Jones
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Low Voltage ◽  
Electron Optics ◽  
Current Interest ◽  
New Concepts ◽  
Opportune Time ◽  
Novel Approaches ◽  
Voltage Scanning ◽  
Scanning Electron

In comparison with the developers of other forms of instrumentation, scanning electron microscope manufacturers are among the most conservative of people. New concepts usually must wait many years before being exploited commercially. The field emission gun, developed by Albert Crewe and his coworkers in 1968 is only now becoming widely available in commercial instruments, while the innovative lens designs of Mulvey are still waiting to be commercially exploited. The associated electronics is still in general based on operating procedures which have changed little since the original microscopes of Oatley and his co-workers.The current interest in low-voltage scanning electron microscopy will, if sub-nanometer resolution is to be obtained in a useable instrument, lead to fundamental changes in the design of the electron optics. Perhaps this is an opportune time to consider other fundamental changes in scanning electron microscopy instrumentation.

Designing Workbook for Teaching Writing Descriptive Text Based on Scientific Approach

2019 ◽  
Vol 1 (2) ◽  
pp. 59
Author(s):  
Indah Pratiwi ◽  
Yanti Sri Rezeki
Keyword(s):  
Teaching Writing ◽  
English Teacher ◽  
Design Development ◽  
Seventh Grade ◽  
Internal Evaluation ◽  
Writing Ability ◽  
Good Book ◽  
Scientific Approach ◽  
Supplementary Material ◽  
Analysis Design

This research aims to design workbook based on the scientific approach for teaching writing descriptive text. This research was conducted on the seventh-grade students of SMPN 24 Pontianak. The method of this research is ADDIE (Analysis, Design, Development, Implementation, and Evaluation) with the exclusion of Implementation and Evaluation phases. This material was designed as supplementary material to support the course book used especially in teaching writing of descriptive text. The respondents in this research were the seventh-grade students and an English teacher at SMPN 24 Pontianak. In this research, the researchers found that workbook based on scientific approach fulfilled the criteria of the good book to teach writing descriptive text. The researchers conducted an internal evaluation to see the usability and the feasibility of the workbook. The result of the evaluation is 89%. It showed that the workbook is feasible to be used by students as the supplementary material to support the main course book and help the students improve their writing ability in descriptive text.

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