Discerning Erionite from Other Zeolite Minerals During Analysis

2020 ◽  
Vol 26 (1) ◽  
pp. 133-139
Author(s):  
Robyn Ray
Keyword(s):  
Rapid Identification ◽  
International Agency ◽  
Air Exposure ◽  
Asbestos Fibers ◽  
Transmission Electron ◽  
Similar Disease ◽  
Community Protection ◽  
Fibrous Mineral ◽  
Preparation Techniques ◽  
Analytical Laboratories

ABSTRACT Erionite, a naturally occurring fibrous mineral that belongs to the zeolite group has been designated by the International Agency for Research on Cancer (IARC) as a Group 1 Carcinogen on the basis of mesothelioma, a disease also resulting from the inhalation of asbestos fibers. Significant outcrops of fibrous erionite have been reported in California, North Dakota, Nevada, Oregon, and other states. For geologists and industrial hygienists dealing with mining, construction, or various aspects of community protection, it is vital to understand the basics of detecting and handling erionite, since it is similar to asbestos and can cause similar disease. There are many fibrous zeolites, and discerning erionite from these other minerals requires modifications to current asbestos analysis methods. Without these modifications, identification and quantification are questionable and could increase the likelihood of both false negatives and false positives. There is currently no published method specific to erionite analysis; without guidance standards, each laboratory has approached erionite analysis independently. With a few small but significant changes to asbestos analysis methodologies, we developed a reproducible analytical procedure for rapid identification of erionite fibers in air, bulk, and soil samples by transmission electron microscopy (TEM). Using specialized preparation techniques, energy dispersive Spectrometry (EDS) calibrations, and a liquid nitrogen cryo-holder (cold stage), we were able to overcome the difficulties associated with erionite analysis. By incorporating these changes, commercial analytical laboratories can contribute reliable data to air-exposure studies and characterization guidelines, which may help in determining regulations and further understanding the health risks of erionite.

Cryomicroscopy of multiphase latices

1991 ◽  
Vol 49 ◽  
pp. 1060-1061
Author(s):  
O. L. Shaffer ◽  
M.S. El-Aasser ◽  
C. L. Zhao ◽  
M. A. Winnik ◽  
R. R. Shivers
Keyword(s):  
Electron Microscopy ◽  
Radiation Damage ◽  
Freeze Fracture ◽  
Particle Morphology ◽  
Second Stage ◽  
Transmission Electron ◽  
Important Approach ◽  
Carbon Coated ◽  
Preparation Techniques

Transmission electron microscopy is an important approach to the characterization of the morphology of multiphase latices. Various sample preparation techniques have been applied to multiphase latices such as OsO4, RuO4 and CsOH stains to distinguish the polymer phases or domains. Radiation damage by an electron beam of latices imbedded in ice has also been used as a technique to study particle morphology. Further studies have been developed in the use of freeze-fracture and the effect of differential radiation damage at liquid nitrogen temperatures of the latex particles embedded in ice and not embedded.Two different series of two-stage latices were prepared with (1) a poly(methyl methacrylate) (PMMA) seed and poly(styrene) (PS) second stage; (2) a PS seed and PMMA second stage. Both series have varying amounts of second-stage monomer which was added to the seed latex semicontinuously. A drop of diluted latex was placed on a 200-mesh Formvar-carbon coated copper grid.

Advanced TEM sample preparation techniques for submicron Si devices

1995 ◽  
Vol 53 ◽  
pp. 516-517 ◽  
Author(s):  
P. B. Basham ◽  
H. L. Tsai
Keyword(s):  
Sample Preparation ◽  
Process Development ◽  
Light Transmission ◽  
Specific Area ◽  
Turnaround Time ◽  
Small Hole ◽  
Area Of Interest ◽  
Transmission Electron ◽  
Polished Side ◽  
Preparation Techniques

The use of transmission electron microscopy (TEM) to support process development of advanced microelectronic devices is often challenged by a large amount of samples submitted from wafer fabrication areas and specific-spot analysis. Improving the TEM sample preparation techniques for a fast turnaround time is critical in order to provide a timely support for customers and improve the utilization of TEM. For the specific-area sample preparation, a technique which can be easily prepared with the least amount of effort is preferred. For these reasons, we have developed several techniques which have greatly facilitated the TEM sample preparation.For specific-area analysis, the use of a copper grid with a small hole is found to be very useful. With this small-hole grid technique, TEM sample preparation can be proceeded by well-established conventional methods. The sample is first polished to the area of interest, which is then carefully positioned inside the hole. This polished side is placed against the grid by epoxy Fig. 1 is an optical image of a TEM cross-section after dimpling to light transmission.

A New Method of Wafer Level Plan View TEM Sample Preparation by DualBeam

2008 ◽  
Author(s):  
Hyoung H. Kang ◽  
Michael A. Gribelyuk ◽  
Oliver D. Patterson ◽  
Steven B. Herschbein ◽  
Corey Senowitz
Keyword(s):  
Sample Preparation ◽  
Ex Situ ◽  
Wafer Level ◽  
Cross Sectional ◽  
Plan View ◽  
Manufacturing Line ◽  
Transmission Electron ◽  
Thin Lamella ◽  
Preparation Techniques

Abstract Cross-sectional style transmission electron microscopy (TEM) sample preparation techniques by DualBeam (SEM/FIB) systems are widely used in both laboratory and manufacturing lines with either in-situ or ex-situ lift out methods. By contrast, however, the plan view TEM sample has only been prepared in the laboratory environment, and only after breaking the wafer. This paper introduces a novel methodology for in-line, plan view TEM sample preparation at the 300mm wafer level that does not require breaking the wafer. It also presents the benefit of the technique on electrically short defects. The methodology of thin lamella TEM sample preparation for plan view work in two different tool configurations is also presented. The detailed procedure of thin lamella sample preparation is also described. In-line, full wafer plan view (S)TEM provides a quick turn around solution for defect analysis in the manufacturing line.

Characterization of FIB Damage in Silicon

1999 ◽  
Vol 5 (S2) ◽  
pp. 740-741 ◽  
Author(s):  
C.A. Urbanik ◽  
B.I. Prenitzer ◽  
L.A. Gianhuzzi ◽  
S.R. Brown ◽  
T.L. Shofner ◽  
...  
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Target Material ◽  
Beam Current ◽  
Specimen Preparation ◽  
Transfer Energy ◽  
Transmission Electron ◽  
Preparation Techniques ◽  
Reactive Gas

Focused ion beam (FIB) instruments are useful for high spatial resolution milling, deposition, and imaging capabilities. As a result, FIB specimen preparation techniques have been widely accepted within the semiconductor community as a means to rapidly prepare high quality, site-specific specimens for transmission electron microscopy (TEM) [1]. In spite of the excellent results that have been observed for both high resolution (HREM) and standard TEM specimen preparation applications, a degree of structural modification is inherent to FIB milled surfaces [2,3]. The magnitude of the damage region that results from Ga+ ion bombardment is dependent on the operating parameters of the FIB (e.g., beam current, beam voltage, milling time, and the use of reactive gas assisted etching).Lattice defects occur as a consequence of FIB milling because the incident ions transfer energy to the atoms of the target material. Momentum transferred from the incident ions to the target atoms can result in the creation of point defects (e.g., vacancies, self interstitials, and interstitial and substitutional ion implantation), the generation of phonons, and plasmon excitation in the case of metal targets.

scholarly journals Rapid identification of capsulated Acinetobacter baumannii using a density-dependent gradient test

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Hadas Kon ◽  
David Schwartz ◽  
Elizabeth Temkin ◽  
Yehuda Carmeli ◽  
Jonathan Lellouche
Keyword(s):  
Rapid Identification ◽  
Control Measures ◽  
Clinical Severity ◽  
Bottom Phase ◽  
Gram Negative ◽  
Density Dependent ◽  
Infection Control Measures ◽  
Transmission Electron ◽  
Total Carbohydrates ◽  
Two Phases

Abstract Background Gram-negative bacterial capsules are associated with production of carbohydrates, frequently resulting in a mucoid phenotype. Infections caused by capsulated or mucoid A. baumannii are associated with increased clinical severity. Therefore, it is clinically and epidemiologically important to identify capsulated A. baumannii. Here, we describe a density-dependent gradient test to distinguish between capsulated and thin/non-capsulated A. baumannii. Results Thirty-one of 57 A. baumannii isolates displayed a mucoid phenotype. The density-dependent gradient test was comprised of two phases, with silica concentrations of 30% (top phase) and 50% (bottom phase). Twenty-three isolates migrated to the bottom phase, indicating thin or non-capsulated strains, and 34 migrated to the top phase, suggesting strains suspected to be capsulated. There was agreement between the mucoid and the non-mucoid phenotypes and the density-dependent gradient test for all but three isolates. Total carbohydrates extracted from strains suspected to be capsulated were significantly higher. Transmission electron microscopy confirmed the presence of a capsule in the six representative strains suspected to be capsulated. Conclusions The density-dependent gradient test can be used to verify capsule presence in mucoid-appearing A. baumannii strains. Identifying capsulated strains can be useful for directing infection control measures to reduce the spread of hypervirulent strains.

Controlled Environment Specimen Transfer

2014 ◽  
Vol 20 (4) ◽  
pp. 1038-1045 ◽  
Author(s):  
Christian D. Damsgaard ◽  
Henny Zandbergen ◽  
Thomas W. Hansen ◽  
Ib Chorkendorff ◽  
Jakob B. Wagner
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Elevated Temperatures ◽  
Controlled Environment ◽  
Ambient Atmosphere ◽  
Air Exposure ◽  
X Ray ◽  
Environmental Transmission ◽  
Transmission Electron

AbstractSpecimen transfer under controlled environment conditions, such as temperature, pressure, and gas composition, is necessary to conduct successive complementary in situ characterization of materials sensitive to ambient conditions. The in situ transfer concept is introduced by linking an environmental transmission electron microscope to an in situ X-ray diffractometer through a dedicated transmission electron microscope specimen transfer holder, capable of sealing the specimen in a gaseous environment at elevated temperatures. Two catalyst material systems have been investigated; Cu/ZnO/Al2O3 catalyst for methanol synthesis and a Co/Al2O3 catalyst for Fischer–Tropsch synthesis. Both systems are sensitive to ambient atmosphere as they will oxidize after relatively short air exposure. The Cu/ZnO/Al2O3 catalyst, was reduced in the in situ X-ray diffractometer set-up, and subsequently, successfully transferred in a reactive environment to the environmental transmission electron microscope where further analysis on the local scale were conducted. The Co/Al2O3 catalyst was reduced in the environmental microscope and successfully kept reduced outside the microscope in a reactive environment. The in situ transfer holder facilitates complimentary in situ experiments of the same specimen without changing the specimen state during transfer.

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