Silicon Defect Observation From Ultra-Thick Sample Using TEM EELS Technique

2021 ◽  
Author(s):  
Gek Li Lee ◽  
Kok Wah Lee ◽  
Jie Zhu
Keyword(s):  
Thick Sample

Pressure Drop Measurements for Air Flow Through Open-Cell Aluminum Foam

2004 ◽  
Author(s):  
Nihad Dukhan ◽  
Angel Alvarez
Keyword(s):  
Reynolds Number ◽  
Pressure Drop ◽  
Flow Rate ◽  
Aluminum Foam ◽  
Flow Direction ◽  
The Other ◽  
Turbulent Regime ◽  
Thick Sample ◽  
Open Cell ◽  
Two Samples

Wind-tunnel pressure drop measurements for airflow through two samples of forty-pore-per-inch commercially available open-cell aluminum foam were undertaken. Each sample’s cross-sectional area perpendicular to the flow direction measured 10.16 cm by 24.13 cm. The thickness in the flow direction was 10.16 cm for one sample and 5.08 cm for the other. The flow rate ranged from 0.016 to 0.101 m3/s for the thick sample and from 0.025 to 0.134 m3/s for the other. The data were all in the fully turbulent regime. The pressure drop for both samples increased with increasing flow rate and followed a quadratic behavior. The permeability and the inertia coefficient showed some scatter with average values of 4.6 × 10−8 m2 and 2.9 × 10−8 m2, and 0.086 and 0.066 for the thick and the thin samples, respectively. The friction factor decayed with the Reynolds number and was weakly dependent on the Reynolds number for Reynolds number greater than 35.

STRAIHGHTFORWARD REPRESENTATION OF A THICK NONLINEAR OPTICAL MATERIAL, WITH LINEAR AND NONLINEAR ABSORPTION

2001 ◽  
Vol 15 (17n19) ◽  
pp. 796-803 ◽  
Author(s):  
R. QUINTERO-TORRES ◽  
F. CARRETO-PARRA ◽  
Z. NAVARRETE-MEZA ◽  
L. ZAMBRANO-VALENCIA
Keyword(s):  
Nonlinear Absorption ◽  
Nonlinear Optical ◽  
Focal Point ◽  
Optical Quality ◽  
Optical Material ◽  
Nonlinear Optical Material ◽  
Gaussian Laser Beam ◽  
Thin Sample ◽  
Thick Sample ◽  
Nonlinear Phase

Z-scan is a technique where a thin sample with good optical quality is scanned through the focus of a gaussian laser beam. A sensor is placed behind a finite aperture in the far field to monitor the output from the sample. A further simplification is obtained measuring transmission only when the sample is close to the focal point, and the aperture is small. In this work. z-scan like results are obtained when a nonlinear optical material is modeled as a set of spherical lenses using geometric optics. Here we discus the thick sample case; sample thicker than the confocal length (defined by the external lens) or samples with nonlinear phase change appreciably different from zero. An absorbent material with instantaneous nonlinear response will be used. With this procedure, an explanation for the distortion in the z-scan is obtained with the increase in the aperture, the nonlinear refractive index and the sample thickness as well as with the presence of nonlinear absorption.

scholarly journals Analysis Using Ion Induced g Rays

1978 ◽  
Vol 31 (2) ◽  
pp. 209 ◽  
Author(s):  
JR Bird ◽  
MD Scott ◽  
LH Russell ◽  
MJ Kenny
Keyword(s):  
Gamma Ray ◽  
Thick Sample ◽  
Nuclear Analysis

Gamma ray energies and some thick sample reaction yields are summarized for proton, deuteron, triton, 3He and IX-particle induced )' rays which have been used in prompt nuclear analysis work.

Effect of focal position on cut surface quality in laser cutting of 50-mm thick stainless steel

2021 ◽  
pp. 2140018
Author(s):  
Moo-Keun Song ◽  
Jong-Do Kim ◽  
Dong-Sig Shin ◽  
Su-Jin Lee ◽  
Dae-Won Cho
Keyword(s):  
Stainless Steel ◽  
Laser Beam ◽  
Laser Cutting ◽  
Nuclear Power ◽  
Surface Characteristics ◽  
Kerf Width ◽  
Power Structures ◽  
Thick Sample ◽  
Focal Position ◽  
Cut Surface

In this study, the parameters for underwater laser cutting of 50-mm thick stainless steel, which is typically used in nuclear power structures, are investigated. The focal position of laser beam significantly affects the cutting quality. In particular, in the cutting of the thick sample, change in the focal position determines the kerf width and the roughness of the cut surface. Moreover, the effects of the variation of kerf width and the cut surface characteristics on the focal position of the laser beam are investigated. As the focal position moved to the inside of the material, the upper kerf width increased, but the quality of the cut surface was improved.

Dynamic behavior of azobenzene polyester used for holographic data storage

2001 ◽  
Vol 674 ◽  
Author(s):  
Árpád Kerekes ◽  
E. Lörincz ◽  
Sz. Sajti ◽  
P. Várhegyi ◽  
P. S. Ramanujam ◽  
...  
Keyword(s):  
Dynamic Behavior ◽  
Data Storage ◽  
Intensity Ratio ◽  
Holographic Recording ◽  
Holographic Data Storage ◽  
Thick Sample ◽  
Model Experiments ◽  
Optimal Intensity ◽  
532 Nm ◽  
Higher Sensitivity

ABSTRACTDynamic behavior of thin photoaddressable polyester films was studied. The saturation process due to Fourier holographic recording was investigated. Model experiments show an optimal intensity ratio of the object and reference beams, where the highest efficiency occurs. This ratio is inversely proportional to the reference intensity. The material has a significantly higher sensitivity at 407 nm than at 532 nm. For 1 μm thick sample an M# of 0.25 was measurable.

Characteristic Morphology and Its Properties of Melt-Crystallized Polyethylene Banded Spherulites on Scanning Electron Microscope

2001 ◽  
Vol 7 (S2) ◽  
pp. 500-501
Author(s):  
Jemyung Park ◽  
Kyuyoung Eom ◽  
Ohjun Kwon
Keyword(s):  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Structure Characterization ◽  
Etching Technique ◽  
Thick Sample ◽  
Bulk Specimen ◽  
Transmission Electron ◽  
Banded Spherulites ◽  
Scanning Electron

In spite of commercial importance of polyethylene(PE), morphologies of melt crystallized PE have been rarely studied. Although, it was possible to observe polyethylene microstructure, they were based on the observation performed almost exclusively on thin films which were obtained either by casting samples between glass plates, or by microtoming the materials with transmission electron microscope(TEM). Despite the usefulness of TEM for detailed investigation of the polyethylene, it is not suitable for the structure characterization of the bulk samples, for examples, the characterization of a thick testpiece and commercial products of polyethylene itself. For such bulk specimen or thick sample, scanning electron microscope (SEM) is more useful, if the appropriate and reliable sample preparation method is applied.In this study, we introduce a chemical etching technique for the investigation of melt crystallized polyethylene microstructure by SEM. Especially in this work we studied the characteristic properties and shapes of polyethylene banded spherulite which come from the melt s.

scholarly journals Contamination Study of Zirconia on the Densification Process and Properties of Transparent MgAl2O4 Ceramics

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 749
Author(s):  
Yi Li ◽  
Qun Zeng ◽  
Jian Zhang ◽  
Dan Han ◽  
Shiwei Wang
Keyword(s):  
Optical Properties ◽  
Hot Isostatic Pressing ◽  
Magnesium Aluminate ◽  
Sintering Behavior ◽  
Pressureless Sintering ◽  
Densification Process ◽  
Thick Sample ◽  
Anion Vacancies ◽  
Average Grain Size ◽  
Zirconia Content

In this paper, transparent magnesium aluminate (MgAl2O4) spinel ceramics are fabricated through pressureless sintering combined with hot isostatic pressing (HIPing). To investigate the effect of zirconia on sintering behavior, microstructure, and optical properties of transparent spinel ceramics, different contents of zirconia were added. The results show that zirconia can promote the densification process by the formation of anion vacancies. The resulting zirconia exists as tetragonal phase along the grain boundaries. The average grain size of resulting ceramics depends on the content of zirconia and HIPing condition. Small zirconia content did not deteriorate the optical properties of samples. A 5-mm-thick sample with 0.05 wt% ZrO2 pre-sintered at 1500 °C followed by HIPing treatment at 1550 °C achieved a high in-line transmittance of 75.5% at 400 nm and 85% at 1100 nm.

Microwave Dielectric Properties of Elastomers Containing Particulate Metal Fillers

1990 ◽  
Vol 189 ◽  
Author(s):  
Barry G.M. Helme
Keyword(s):  
Dielectric Properties ◽  
Metal Particle ◽  
Microwave Dielectric Properties ◽  
Skin Depth ◽  
High Conductivity ◽  
Microwave Properties ◽  
Thick Sample ◽  
Microwave Dielectric ◽  
Particulate Metal ◽  
Filler Particles

ABSTRACTElastomers have been manufactured containing varying concentrations of particles of Ag/Al, Ag/Cu, Ag/Ni, Ag/glass (G3), Ni/graphite, Ni, and Ag. Their dielectric and microwave properties have been measured between 0.4 GHz and 40 GHz and at temperatures between ambient and 100°C. The filler particles are small relative to the microwave wavelength but larger than the skin depth. Sheets of these elastomers of up to 2 mm thickness gave been subjected to cyclical stretching of up to 40% elongation and up to 10° cycles. The microwave properties have been measured as a function of numbers of stretching cycles and composition of elastomer. Some correlations were found between the composition, the microwave properties and the number of stretch cycles completed.It was found in general that repeated stretching degraded the initially high conductivity of the loaded elastomers. This effect was also revealed by the increase in microwave transmissivity through the sheets, and a decrease in reflectivity. Formulations of elastomer-metal particle mix have recently been produced which have a microwave transmissivity more Phan 80 dB below the incident signal, for a 2 mm thick sample, even after 106 stretching cycles of 20% elongation. This property is of great value for the use of the elastomer as a reflective microwave shield.

Characterization of Lithium Ion Battery Materials with Valence Electron Energy-Loss Spectroscopy

2018 ◽  
Vol 24 (3) ◽  
pp. 214-220 ◽  
Author(s):  
Fernando C. Castro ◽  
Vinayak P. Dravid
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Mixed Oxides ◽  
Lithium Ion ◽  
Atomic Scale ◽  
Spectral Processing ◽  
Thick Sample ◽  
Battery Materials ◽  
Electron Energy Loss

AbstractCutting-edge research on materials for lithium ion batteries regularly focuses on nanoscale and atomic-scale phenomena. Electron energy-loss spectroscopy (EELS) is one of the most powerful ways of characterizing composition and aspects of the electronic structure of battery materials, particularly lithium and the transition metal mixed oxides found in the electrodes. However, the characteristic EELS signal from battery materials is challenging to analyze when there is strong overlap of spectral features, poor signal-to-background ratios, or thicker and uneven sample areas. A potential alternative or complementary approach comes from utilizing the valence EELS features (<20 eV loss) of battery materials. For example, the valence EELS features in LiCoO2 maintain higher jump ratios than the Li–K edge, most notably when spectra are collected with minimal acquisition times or from thick sample regions. EELS maps of these valence features give comparable results to the Li–K edge EELS maps of LiCoO2. With some spectral processing, the valence EELS maps more accurately highlight the morphology and distribution of LiCoO2 than the Li–K edge maps, especially in thicker sample regions. This approach is beneficial for cases where sample thickness or beam sensitivity limit EELS analysis, and could be used to minimize electron dosage and sample damage or contamination.

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