Glass Knife Geometry as Seen by the SEM

1971 ◽  
Vol 29 ◽  
pp. 454-455
Author(s):  
J. Temple Black
Keyword(s):  
Low Cost ◽  
Amorphous Material ◽  
Stress Concentrations ◽  
Basic Tool ◽  
Tool Materials ◽  
Optical Inspection ◽  
Surface Flaws ◽  
Slip Planes ◽  
Glass Knife ◽  
Diamond Knife

In ultramicrotomy, the two basic tool materials are glass and diamond. Glass because of its low cost and ease of manufacture of the knife itself is still widely used despite the superiority of diamond knives in many applications. Both kinds of knives produce plastic deformation in the microtomed section due to the nature of the cutting process and microscopic chips in the edge of the knife. Because glass has no well defined slip planes in its structure (it's an amorphous material), it is very strong and essentially never fails in compression. However, surface flaws produce stress concentrations which reduce the strength of glass to 10,000 to 20,000 psi from its theoretical or flaw free values of 1 to 2 million psi. While the microchips in the edge of the glass or diamond knife are generally too small to be observed in the SEM, the second common type of defect can be identified. This is the striations (also termed the check marks or feathers) which are always present over the entire edge of a glass knife regardless of whether or not they are visable under optical inspection. These steps in the cutting edge can be observed in the SEM by proper preparation of carefully broken knives and orientation of the knife, with respect to the scanning beam.

Sem Examinations of Glass Knives

1970 ◽  
Vol 28 ◽  
pp. 282-283
Author(s):  
J. Temple Black
Keyword(s):  
Plastic Deformation ◽  
Tensile Loading ◽  
Resultant Force ◽  
Stress Concentrations ◽  
Edge Chipping ◽  
Surface Flaws ◽  
Edge Defects ◽  
Microscopic Surface

There are two types of edge defects common to glass knives as typically prepared for microtomy purposes: 1) striations and 2) edge chipping. The former is a function of the free breaking process while edge chipping results from usage or bumping of the edge. Because glass has no well defined planes in its structure, it should be highly resistant to plastic deformation of any sort, including tensile loading. In practice, prevention of microscopic surface flaws is impossible. The surface flaws produce stress concentrations so that tensile strengths in glass are typically 10-20 kpsi and vary only slightly with composition. If glass can be kept in compression, wherein failure is literally unknown (1), it will remain intact for long periods of time. Forces acting on the tool in microtomy produce a resultant force that acts to keep the edge in compression.

scholarly journals Immunohistochemical typing of amyloid in fixed paraffin-embedded samples by an automatic procedure: Comparison with immunofluorescence data on fresh-frozen tissue

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256306
Author(s):  
Antonella Barreca ◽  
Emanuel Bottasso ◽  
Francesca Veneziano ◽  
Manuela Giarin ◽  
Alberto Nocifora ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gold Standard ◽  
Retrospective Cohort ◽  
Low Cost ◽  
Amorphous Material ◽  
Immunogold Labeling ◽  
Frozen Tissue ◽  
Fresh Frozen ◽  
Antibody Panel ◽  
Automated Platform

Amyloidosis comprises a spectrum of disorders characterized by the extracellular deposition of amorphous material, originating from an abnormal serum protein. The typing of amyloid into its many variants represents a pivotal step for a correct patient management. Several methods are currently used, including mass spectrometry, immunofluorescence, immunohistochemistry, and immunogold labeling. The aim of the present study was to investigate the accuracy and reliability of immunohistochemistry by means of a recently developed amyloid antibody panel applicable on fixed paraffin-embedded tissues in an automated platform. Patients with clinically and pathologically proven amyloidosis were divided into two cohorts: a pilot one, which included selected amyloidosis cases from 2009 to 2018, and a retrospective one (comprising all consecutive amyloidosis cases analyzed between November 2018 and May 2020). The above-referred panel of antibodies for amyloid classification was tested in all cases using an automated immunohistochemistry platform. When fresh-frozen material was available, immunofluorescence was also performed. Among 130 patients, a total of 143 samples from different organs was investigated. They corresponded to 51 patients from the pilot cohort and 79 ones from the retrospective cohort. In 82 cases (63%), fresh-frozen tissue was tested by immunofluorescence, serving to define amyloid subtype only in 30 of them (36.6%). On the contrary, the automated immunohistochemistry procedure using the above-referred new antibodies allowed to establish the amyloid type in all 130 cases (100%). These included: ALλ (n = 60, 46.2%), ATTR (n = 29, 22.3%), AA (n = 19, 14.6%), ALκ (n = 18, 13.8%), ALys (n = 2, 1.5%), and Aβ2M amyloidosis (n = 2, 1.5%). The present immunohistochemistry antibody panel represents a sensitive, reliable, fast, and low-cost method for amyloid typing. Since immunohistochemistry is available in most pathology laboratories, it may become the new gold standard for amyloidosis classification, either used alone or combined with mass spectrometry in selected cases.

Practical methods for TEM

1996 ◽  
Vol 54 ◽  
pp. 628-629
Author(s):  
K. Chien ◽  
R. Gonzalez ◽  
R. C. Heusser ◽  
H. Shiroishi ◽  
M. L. Heathershaw
Keyword(s):  
Needle Biopsy ◽  
Long Distance ◽  
Hot Plate ◽  
Razor Blade ◽  
Thin Sectioning ◽  
Block Face ◽  
Single Block ◽  
The Difference ◽  
Glass Knife ◽  
Diamond Knife

Multiple sectioning: Two or more core specimens from a kidney needle biopsy can be embedded in single block using an 8-facet silicone rubber embedding mold. Tissue blocks are softened by placing them face down on an 85°C hot plate for one minute and then trimming with a Teflon coated razor blade. This prevents the block face from being deeply fractured which can affect section quality. If glomeruli are found within different cores in a single block, the block face can be retrimmed into multiple mesas and simultaneously thin-sectioned. This method greatly increases the efficiency of both thick and thin sectioning which is extremely helpful when handling more than 1600 cases of renal biopsies in our EM laboratory each year.Knife Spacer: Due to the difference in thickness between a glass and diamond knife, and also depending on which portion of the diamond knife is being used, the knife stage has to be moved laterally over a long distance when changing from one knife type to the other. Placing a L-shaped spacer, 3 to 5 mm in thickness, on the left side of the stage when sectioning a glass knife will greatly reduce this lateral adjustment.

Comparative Evaluation of Efficiency of Metal-Cutting Tool by Method of Pendulum Scribing

2015 ◽  
Vol 798 ◽  
pp. 452-456 ◽  
Author(s):  
Boris Y. Mokritskii ◽  
Dmitriy A. Pustovalov ◽  
Alexey Anatolevich Vereschaka
Keyword(s):  
Material Properties ◽  
Comparative Evaluation ◽  
Metal Cutting ◽  
Cutting Tool ◽  
Low Cost ◽  
Tool Material ◽  
Maximum Width ◽  
Tool Materials ◽  
Metal Cutting Tool ◽  
The Relationship

Method of pendulum scribing was investigated in terms of the possibilities of using this method as a simple-to-use way with a relatively low cost for rapid evaluation of tool material properties. It has been established that by using this method the conditions of loading of the tool material are closest to the real conditions in which the tool operates. Was revealed the relationship between the maximum width and length of the track pendulum scribing and physico-mechanical properties of tool materials. Application of the proposed methodology allows passing to predicting the performance properties of the tool, such as tool life under the specified conditions.

SEM, STEM, and HVTEM Examinations of Aluminum Thin Films Produced by Glass Knife Microtomy

1972 ◽  
Vol 30 ◽  
pp. 466-467
Author(s):  
J. Temple Black
Keyword(s):  
Thin Films ◽  
Metal Cutting ◽  
High Strain ◽  
Large Strain ◽  
Orthogonal Cutting ◽  
Internal Defect ◽  
Thinning Operations ◽  
Electron Microscopes ◽  
Glass Knife ◽  
Diamond Knife

One of the more interesting aspects of the microtomy process lies in its application to the cutting of metals. It has been found that many softer metals can be microtomed with a glass knife as well as with the traditional diamond knife. These thin films can be used to study the deformation mechanism and defect physics of the cutting process. The microtomy process is actually orthogonal cutting (2 force mechanics) on a refined scale. Metal cutting is a unique mode of plastic deformation in that it is a large strain, high strain rate process, which produces a characteristic, fundamental deformation. Chips produced by thin film microtomy methods can be examined directly in the various electron microscopes without any subsequent thinning operations which may disturb the deformation structure. In addition, it is possible to examine the same areas of the specimen for both external morphology features (via SEM imagery) and internal defect arrangements (via STEM and HVTEM imagery) and thus one can observe directly how these structures are related.

Influence of Lubricant Pressure Response on Subsurface Stress in Elastohydrodynamically Lubricated Finite Line Contacts

2018 ◽  
Vol 141 (3) ◽  
Author(s):  
Tobias Hultqvist ◽  
Aleks Vrcek ◽  
Braham Prakash ◽  
Pär Marklund ◽  
Roland Larsson
Keyword(s):  
Low Cost ◽  
Elastohydrodynamic Lubrication ◽  
Pressure Response ◽  
Stress Concentrations ◽  
Oil Viscosity ◽  
Lubricated Contacts ◽  
Low Viscosity ◽  
Line Contacts ◽  
Finite Line ◽  
Subsurface Stress

In order to adapt to increasingly stringent CO2 regulations, the automotive industry must develop and evaluate low cost, low emission solutions in the powertrain technology. This often implies increased power density and the use of low viscosity oils, leading to additional challenges related to the durability of various machine elements. Therefore, an increased understanding of lubricated contacts becomes important where oil viscosity–pressure and compressibility–pressure behavior have been shown to influence the film thickness and pressure distribution in elastohydrodynamic lubrication (EHL) contacts, further influencing the durability. In this work, a finite line EHL contact is analyzed with focus on the oil compressibility–pressure and viscosity–pressure response, comparing two oils with relatively different behavior and its influence on subsurface stress concentrations in the contacting bodies. Results indicate that increased pressure gradients and pressure spikes, and therefore increased localized stress concentrations, can be expected for stiffer, less compressible oils, which under transient loading conditions not only affect the outlet but also the edges of the roller.

scholarly journals Process Transferability of Friction Riveting of AA2024-T351/Polyetherimide (PEI) Joints Using Hand-Driven, Low-Cost Drilling Equipment

Processes ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 1376
Author(s):  
Anamaria Feier ◽  
Andrei Becheru ◽  
Mihai Brîndușoiu ◽  
Lucian Blaga
Keyword(s):  
Low Cost ◽  
Tensile Loading ◽  
Drilling Machine ◽  
Stress Concentrations ◽  
Laboratory Equipment ◽  
Pullout Tests ◽  
Joining Technology ◽  
Drilling Equipment ◽  
Maximum Value ◽  
Tensile Forces

The present work deals with the transferability of Friction Riveting joining technology from laboratory equipment to adapted in-house, low-cost machinery. A G13 drilling machine was modified for the requirements of the selected joining technique, and joints were performed using polyethermide plates and AA2024 aluminum alloy rivets of 6 mm diameter. This diameter was not previously reported for Friction Riveting. The produced joints were mechanically tested under tensile loading (pullout tests) with ultimate tensile forces of 9500 ± 900 N. All tested specimens failed through full-rivet pullout, which is the weakest reported joint in Friction Riveting. In order to understand this behavior, FE models were created and analyzed. The models produced were in agreement with the experimental results, with failure initiated within the polymer under stress concentrations in the polymeric material above the deformed metallic anchor at an ultimate value of the stress of 878 MPa at the surface of the joint. Stresses decreased to less than half of the maximum value around the anchoring zone while the rivet was removed and towards the surface. The paper thus demonstrates the potential ease of applying and reproducing Friction Riveting with simple machinery, while contributing to an understanding of the mechanical behavior (initialization of failure) of joints.

scholarly journals Geographic Information Systems supported by multi-criteria decision analysis to indicate potentially suitable areas for construction and demolition waste disposal

2021 ◽  
Vol 56 (3) ◽  
pp. 470-479
Author(s):  
Barbara Pavani Biju ◽  
André Nagalli ◽  
Edilberto Nunes De Moura
Keyword(s):  
Spatial Data ◽  
Research Study ◽  
Social Economic ◽  
Low Cost ◽  
Construction And Demolition Waste ◽  
Basic Tool ◽  
Demolition Waste ◽  
Class A ◽  
Standards And Regulations ◽  
Fast Decision

In Brazil, the disposal of construction and demolition waste (CDW) quite often occurs in inadequate places, resulting in social, economic, and environmental problems. This reflects the need for selecting appropriate areas for the disposal of this type of waste. These areas must follow local standards and regulations to protect human health and the environment. Considering that, this study is intended to indicate potentially suitable areas for CDW landfill deployment, known as Class A landfill in Brazil, supported by a GIS-MCDA based model. The GIS-MCDA technique, used as a basic tool to identify potentially suitable areas, has several advantages, such as low cost, reduced spatial data subjectivity, and fast decision-making process. The place chosen for this study is the Urban Central Core of the Metropolitan Area of Curitiba. By integrating GIS with MCDA techniques in this research study, it was possible to indicate potentially suitable areas for CDW disposal in this region.

scholarly journals Characterization of a new laboratory ceramic product from industrial by-products as raw materials and caustic magnesia as additive

2013 ◽  
Vol 47 (4) ◽  
pp. 2050
Author(s):  
V. Skliros ◽  
P. G. Lampropoulou ◽  
B. Tsikouras ◽  
K. Hatzipanagiotou ◽  
A. Christogerou ◽  
...  
Keyword(s):  
Building Materials ◽  
Raw Materials ◽  
Low Cost ◽  
Amorphous Material ◽  
Bottom Ash ◽  
Ceramic Product ◽  
Ceramic Building ◽  
Experimental Firing ◽  
By Products ◽  
Caustic Magnesia

A new ceramic product is introduced by mixing caustic magnesia, produced in the laboratory from pure, high quality magnesite, and natural silt. Bottom ash and red mud, two well known environmentally hazardous industrial by-products, were also added in the mixture. After testing various recipes we concluded that addition of 5% caustic magnesia in the ceramic product greatly enhances its performance. Increase bonding of the ceramic microstructure is attributed to the formation of periclase necks, the concurrent formation of small quantities of amorphous material and the homogeneously distributed pores during the experimental firing of the mixture. Combined X-ray Diffractometry and Scanning Electron Microscopy of the ceramic product revealed the occurrence of unreactive phases, inherited by the raw materials, as well as newly-formed albite and magnesioferrite. Our results show that utilization of by-products may be important and environmental friendly materials in producing low cost ceramic building materials.

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