scholarly journals P-SV wave diffusion in fluid-saturated medium

2014 ◽  
Vol 6 (1) ◽  
Author(s):  
Dennis Ling C.C. ◽  
Zainal A.A.
Keyword(s):  
Rayleigh Waves ◽  
High Density ◽  
Low Density ◽  
Fluid Density ◽  
Diffusion Characteristic ◽  
Rotating Waves ◽  
Snell Law ◽  
Wave Diffusion ◽  
Saturated Medium

Propagating P-SV waves in the fluid-saturated mediums are categorized to fall into two distinct groups: insoluble and soluble mediums. These waves are known as surface Rayleigh waves. By introducing these waves with slowness in accordance to Snell Law, the diffusive and rotating waves are obtained. The results bear out that the propagating P-SV waves in soluble medium share similar diffusion characteristic as of insoluble medium while the discussions on fluid density in the mediums show that high density fluid promotes diffusive characteristic while low density fluid endorses nondiffusive P-SV waves. There is a compressed zone during the propagation of P-SV waves in medium saturated with high density fluids.

SV-WAVE WITH EXTERNAL FORCE IN SATURATED MEDIUM

2016 ◽  
Vol 78 (3-2) ◽  
Author(s):  
Teng Lie Siang ◽  
Zainal Abdul Aziz ◽  
Dennis Ling Chuan Ching
Keyword(s):  
External Force ◽  
Analytical Solutions ◽  
Wave Model ◽  
High Density ◽  
Low Density ◽  
Duhamel Principle ◽  
Wave Diffusion ◽  
Saturated Medium

There are past researches done for SV-wave with the absence of external force. This work aims to investigate the influence of external force in the propagation of SV-wave in the soluble and insoluble mediums. Isotropic wave model is derived for SV-wave with various forces in accordance to Duhamel Principle and their analytical solutions are used to compare with each other’s’ amplitudes. With the existence of high density fluid, diffusive waves with larger external force will induce higher amplitude. However, SV-waves are non-diffusive in low density medium and hence, this work concludes that wave diffusion by external force is subjected to the properties of the targeted medium

Quantitative defect studies in semiconductor TEM samples prepared by low angle ion milling

1995 ◽  
Vol 53 ◽  
pp. 512-513
Author(s):  
L. Mulestagno ◽  
J.C. Holzer ◽  
P. Fraundorf
Keyword(s):  
Sample Preparation ◽  
Milling Time ◽  
High Density ◽  
Low Density ◽  
Ion Milling ◽  
High Quality ◽  
Variable Angle ◽  
Major Disadvantage ◽  
Induced Defects

Due to the wealth of information, both analytical and structural that can be obtained from it TEM always has been a favorite tool for the analysis of process-induced defects in semiconductor wafers. The only major disadvantage has always been, that the volume under study in the TEM is relatively small, making it difficult to locate low density defects, and sample preparation is a somewhat lengthy procedure. This problem has been somewhat alleviated by the availability of efficient low angle milling.Using a PIPS® variable angle ion -mill, manufactured by Gatan, we have been consistently obtaining planar specimens with a high quality thin area in excess of 5 × 104 μm2 in about half an hour (milling time), which has made it possible to locate defects at lower densities, or, for defects of relatively high density, obtain information which is statistically more significant (table 1).

Scanning Electron Microscopic and Electrophoretic Observations on Barium Sulphate Used to Adsorb Clotting Factors

1975 ◽  
Vol 33 (02) ◽  
pp. 256-270
Author(s):  
R. M Howell ◽  
S. L. M Deacon
Keyword(s):  
Electron Microscopy ◽  
Factor Xa ◽  
Barium Sulphate ◽  
High Density ◽  
Low Density ◽  
Factor X ◽  
Clotting Factors ◽  
Electron Microscopic ◽  
Complementary Techniques ◽  
Scanning Electron

SummaryElectron microscopy and particle electrophoresis were found to be complementary techniques with which to complete the physical data from an earlier study on barium sulphates used to adsorb clotting factors from serum. The differences revealed by scanning electron microscopy (S. E. M.) in the physical shape of low and high density grades of barium sulphate particles appear to be of greater significance than charge as expressed by electrophoretic mobility, in determining whether or not precursor or preformed factor Xa is eluted.This conclusion was based on the finding that at pH values close to 7, where the adsorption from serum occurs, all samples with the exception of natural barytes were uncharged. However as the high-density, or soil-grade, was found by S. E. M. to consist of large solid crystals it was suggested that this shape might induce activation of factor X as a result of partial denaturation and consequent unfolding of the adsorbed protein. In contrast, uptake of protein into the centre of the porous aggregates revealed by S. E. M. pictures of low-density or X-ray grade barium sulphate may afford protection against denaturation and exposure of the enzyme site.The porous nature of particles of low-density barium sulphate compared with the solid crystalline forms of other grades accounts not only for its lower bulk density but also for its greater surface/gram ratio which is reflected by an ability to adsorb more protein from serum.Neither technique produced evidence from any of the samples to indicate the presence of stabilising agents sometimes used to coat particles in barium meals.

scholarly journals Low-Temperature Mechanical Properties of High-Density and Low-Density Polyethylene and Their Blends

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1821
Author(s):  
Ildar I. Salakhov ◽  
Nadim M. Shaidullin ◽  
Anatoly E. Chalykh ◽  
Mikhail A. Matsko ◽  
Alexey V. Shapagin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Low Temperature ◽  
Impact Strength ◽  
Relative Elongation ◽  
High Density ◽  
Low Density Polyethylene ◽  
Low Density ◽  
Elongation At Break ◽  
Subzero Temperatures ◽  
Izod Impact

Low-temperature properties of high-density polyethylene (HDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), and their blends were studied. The analyzed low-temperature mechanical properties involve the deformation resistance and impact strength characteristics. HDPE is a bimodal ethylene/1-hexene copolymer; LDPE is a branched ethylene homopolymer containing short-chain branches of different length; LLDPE is a binary ethylene/1-butene copolymer and an ethylene/1-butene/1-hexene terpolymer. The samples of copolymers and their blends were studied by gel permeation chromatography (GPC), differential scanning calorimetry (DSC), 13С NMR spectroscopy, and dynamic mechanical analysis (DMA) using testing machines equipped with a cryochamber. It is proposed that such parameters as “relative elongation at break at −45 °C” and “Izod impact strength at −40 °C” are used instead of the ductile-to-brittle transition temperature to assess frost resistance properties because these parameters are more sensitive to deformation and impact at subzero temperatures for HDPE. LLDPE is shown to exhibit higher relative elongation at break at −45 °C and Izod impact strength at −20 ÷ 60 °C compared to those of LDPE. LLDPE terpolymer added to HDPE (at a content ≥ 25 wt.%) simultaneously increases flow properties and improves tensile properties of the blend at −45 °C. Changes in low-temperature properties as a function of molecular weight, MWD, crystallinity, and branch content were determined for HDPE, LLDPE, and their blends. The DMA data prove the resulting dependences. The reported findings allow one to understand and predict mechanical properties in the HDPE–LLDPE systems at subzero temperatures.

scholarly journals High-density Néel-type magnetic skyrmion phase stabilized at high temperature

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Hee Young Kwon ◽  
Kyung Mee Song ◽  
Juyoung Jeong ◽  
Ah-Yeon Lee ◽  
Seung-Young Park ◽  
...  
Keyword(s):  
High Temperature ◽  
High Density ◽  
Low Density ◽  
Memory Devices ◽  
Magnetic Multilayer ◽  
Multilayer Systems ◽  
Micromagnetic Simulations ◽  
Transmission Electron ◽  
Ultrahigh Density ◽  
Lorentz Transmission Electron Microscopy

AbstractThe discovery of a thermally stable, high-density magnetic skyrmion phase is a key prerequisite for realizing practical skyrmionic memory devices. In contrast to the typical low-density Néel-type skyrmions observed in technologically viable multilayer systems, with Lorentz transmission electron microscopy, we report the discovery of a high-density homochiral Néel-type skyrmion phase in magnetic multilayer structures that is stable at high temperatures up to 733 K (≈460 °C). Micromagnetic simulations reveal that a high-density skyrmion phase can be stabilized at high temperature by deliberately tuning the magnetic anisotropy, magnetic field, and temperature. The existence of the high-density skyrmion phase in a magnetic multilayer system raises the possibility of incorporating chiral Néel-type skyrmions in ultrahigh-density spin memory devices. Moreover, the existence of this phase at high temperature shows its thermal stability, demonstrating the potential for skyrmion devices operating in thermally challenging modern electronic chips.

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