scholarly journals Standardless Quantitative EPMA of Microparticles with Irregular Shapes

2020 ◽  
Vol 26 (S2) ◽  
pp. 504-506
Author(s):  
Mouad Essani ◽  
Emmanuelle Brackx ◽  
Philippe Jonnard ◽  
Emmanuel Excoffier
Keyword(s):  
Irregular Shapes ◽  
Quantitative Epma

Quantitative EPMA of nitrogen : A tricky element in the electron-probe microanalyzer

1992 ◽  
Vol 50 (2) ◽  
pp. 1622-1623
Author(s):  
G.F. Bastin ◽  
H.J.M. Heijligers
Keyword(s):  
Background Subtraction ◽  
Electron Probe ◽  
Detection System ◽  
Higher Order ◽  
Light Elements ◽  
Strong Suppression ◽  
Electron Probe Microanalyzer ◽  
Quantitative Epma ◽  
Peak Count ◽  
Lead Stearate

Among the ultra-light elements B, C, N, and O nitrogen is the most difficult element to deal with in the electron probe microanalyzer. This is mainly caused by the severe absorption that N-Kα radiation suffers in carbon which is abundantly present in the detection system (lead-stearate crystal, carbonaceous counter window). As a result the peak-to-background ratios for N-Kα measured with a conventional lead-stearate crystal can attain values well below unity in many binary nitrides . An additional complication can be caused by the presence of interfering higher-order reflections from the metal partner in the nitride specimen; notorious examples are elements such as Zr and Nb. In nitrides containing these elements is is virtually impossible to carry out an accurate background subtraction which becomes increasingly important with lower and lower peak-to-background ratios. The use of a synthetic multilayer crystal such as W/Si (2d-spacing 59.8 Å) can bring significant improvements in terms of both higher peak count rates as well as a strong suppression of higher-order reflections.

A quantitative image analysis method for the determination of cocontinuity in polymer blends

1993 ◽  
Vol 51 ◽  
pp. 894-895
Author(s):  
William A. Heeschen
Keyword(s):  
Image Analysis ◽  
Polymer Blends ◽  
Quantitative Measurement ◽  
Morphological Evolution ◽  
Phase Ratio ◽  
Irregular Shapes ◽  
Quantitative Image ◽  
Discrete Domains ◽  
A Domains

Two new morphological measurements based on digital image analysis, CoContinuity and CoContinuity Balance, have been developed and implemented for quantitative measurement of morphology in polymer blends. The morphology of polymer blends varies with phase ratio, composition and processing. A typical morphological evolution for increasing phase ratio of polymer A to polymer B starts with discrete domains of A in a matrix of B (A/B < 1), moves through a cocontinuous distribution of A and B (A/B ≈ 1) and finishes with discrete domains of B in a matrix of A (A/B > 1). For low phase ratios, A is often seen as solid convex particles embedded in the continuous B phase. As the ratio increases, A domains begin to evolve into irregular shapes, though still recognizable as separate domains. Further increase in the phase ratio leads to A domains which extend into and surround the B phase while the B phase simultaneously extends into and surrounds the A phase.

Measurement And Simulation Of X-Ray Emission From Multilayered Structures In Electron Probe Microanalysis.

1999 ◽  
Vol 5 (S2) ◽  
pp. 78-79
Author(s):  
C. Merlet ◽  
X. Llovet ◽  
F. Salvat
Keyword(s):  
Electron Probe ◽  
Numerical Models ◽  
Carbon Layer ◽  
Single Element ◽  
Surface Ionization ◽  
Copper Films ◽  
Multilayered Structures ◽  
X Ray ◽  
Electron Probe Microanalyzer ◽  
Quantitative Epma

Studies of x-ray emission from thin films on substrates using an electron probe microanalyzer (EPMA) provide useful information on the characteristics of x-ray generation by electron beams. In this study, EPMA measurements of multilayered samples were performed in order to test and improve analytical and numerical models used for quantitative EPMA. These models provide relatively accurate results for samples consisting of layers with similar average atomic numbers, because of their similar properties regarding electron transport and x-ray generation. On the contrary, these models find difficulties to describe the process when the various layers have very different atomic numbers. In a previous work, we studied the surface ionization of thin copper films of various thicknesses deposited on substrates with very different atomic numbers. In the present communication, the study is extended to the case of multilayered specimens.The studied specimens consisted of thin copper films deposited on a carbon layer which, in turn, was placed on a variety of single-element substrates, ranging from Be to Bi.

scholarly journals Impact of Liposomal Drug Formulations on the RBCs Shape, Transmembrane Potential, and Mechanical Properties

2021 ◽  
Vol 22 (4) ◽  
pp. 1710
Author(s):  
Sylwia Cyboran-Mikołajczyk ◽  
Przemysław Sareło ◽  
Robert Pasławski ◽  
Urszula Pasławska ◽  
Magdalena Przybyło ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Side Effects ◽  
Blood Cells ◽  
Transmembrane Potential ◽  
Drug Formulations ◽  
Liposomal Drug ◽  
Irregular Shapes ◽  
Liposomal Formulations ◽  
Current Therapies ◽  
Negative Side Effects

Liposomal technologies are used in order to improve the effectiveness of current therapies or to reduce their negative side effects. However, the liposome–erythrocyte interaction during the intravenous administration of liposomal drug formulations may result in changes within the red blood cells (RBCs). In this study, it was shown that phosphatidylcholine-composed liposomal formulations of Photolon, used as a drug model, significantly influences the transmembrane potential, stiffness, as well as the shape of RBCs. These changes caused decreasing the number of stomatocytes and irregular shapes proportion within the cells exposed to liposomes. Thus, the reduction of anisocytosis was observed. Therefore, some nanodrugs in phosphatidylcholine liposomal formulation may have a beneficial effect on the survival time of erythrocytes.

scholarly journals Clustering Irregular Shapes Using High-Order Neurons

2000 ◽  
Vol 12 (10) ◽  
pp. 2331-2353 ◽  
Author(s):  
H. Lipson ◽  
H. T. Siegelmann
Keyword(s):  
Synaptic Weight ◽  
Hebbian Learning ◽  
Second Order ◽  
High Order ◽  
Maximum Correlation ◽  
Overlapping Clusters ◽  
Homogeneous Coordinates ◽  
Irregular Shapes ◽  
Data Clusters ◽  
Iris Data

This article introduces a method for clustering irregularly shaped data arrangements using high-order neurons. Complex analytical shapes are modeled by replacing the classic synaptic weight of the neuron by high-order tensors in homogeneous coordinates. In the first- and second-order cases, this neuron corresponds to a classic neuron and to an ellipsoidal-metric neuron. We show how high-order shapes can be formulated to follow the maximum-correlation activation principle and permit simple local Hebbian learning. We also demonstrate decomposition of spatial arrangements of data clusters, including very close and partially overlapping clusters, which are difficult to distinguish using classic neurons. Superior results are obtained for the Iris data.

Performance of Polishing Slurries containing Silica Particles grown by Sol-Gel Method

2000 ◽  
Vol 613 ◽  
Author(s):  
Sun Hyuk Bae ◽  
Jae-Hyun So ◽  
Seung-Man Yang ◽  
Do Hyun Kim
Keyword(s):  
Fumed Silica ◽  
Sol Gel ◽  
Particle Growth ◽  
Silica Particles ◽  
Gel Method ◽  
Sol Gel Method ◽  
Irregular Shapes ◽  
Wafer Polishing ◽  
Transmission Electron ◽  
Silica Slurry

ABSTRACTSilica slurry used as abrasives in wafer polishing process is made by dispersing silica particles in an alkali solution. Since commercially available colloidal or fumed silica particles need some modifications to be directly used as abrasive slurry due to their small sizes, irregular shapes or broad size distribution, we have prepared silica abrasives by particle growth of fumed silica or colloidal silica as seeds by sol-gel method. Silica slurries prepared by this step-wise growth from commercial seeds were tested using one-armed polisher for the comparison with commercial slurries and showed the performance comparable to commercial slurries. Microstructures of polishing slurries were investigated using transmission electron microscopy and ARES rheometer. From the result, stability of the slurry was found to be more important than the primary particle sizes for the polishing performance.

Flexible silicon nanowires sensor for acetone detection on plastic substrates

2021 ◽  
Author(s):  
Kuibo Lan ◽  
Zhi Wang ◽  
Xiaodong Yang ◽  
Junqing Wei ◽  
Yuxiang Qin ◽  
...  
Keyword(s):  
Silicon Nanowires ◽  
High Performance ◽  
Underlying Mechanism ◽  
Environmental Safety ◽  
Cmos Process ◽  
Plastic Substrates ◽  
Irregular Shapes ◽  
Good Potential ◽  
Mechanical Bending ◽  
Acetone Detection

Abstract Acetone commonly exists in daily life and is harmful to human health, therefore the convenient and sensitive monitoring of acetone is highly desired. In addition, flexible sensors have the advantages of light-weight, conformal attachable to irregular shapes, etc. In this study, we fabricated high performance flexible silicon nanowires (SiNWs) sensor for acetone detection by transferring the monocrystalline Si film and metal-assisted chemical etching method on polyethylene terephthalate (PET). The SiNWs sensor enabled detection of gaseous acetone with a concentration as low as 0.1 parts per million (ppm) at flat and bending states. The flexible SiNWs sensor was compatible with the CMOS process and exhibited good sensitivity, selectivity and repeatability for acetone detection at room temperature. The flexible sensor showed performance improvement under mechanical bending condition and the underlying mechanism was discussed. The results demonstrated the good potential of the flexible SiNWs sensor for the applications of wearable devices in environmental safety, food quality, and healthcare.

Irregular Shapes: Randomness in Fractal Constructions

1992 ◽  
pp. 379-432
Author(s):  
Heinz-Otto Peitgen ◽  
Hartmut Jürgens ◽  
Dietmar Saupe
Keyword(s):  
Irregular Shapes
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