scholarly journals A new method to determine open porosity and permeability constants of open-pore sintered glasses by photoacoustic technique

Cerâmica ◽  
2005 ◽  
Vol 51 (319) ◽  
pp. 259-264
Author(s):  
M. T. Yasuda ◽  
W. L. B. Melo
Keyword(s):  
Structural Properties ◽  
Open Porosity ◽  
Porous Ceramic ◽  
Photoacoustic Signal ◽  
Photoacoustic Technique ◽  
Excellent Correlation ◽  
Grain Sizes ◽  
Porosity And Permeability ◽  
Permeability Constants ◽  
Non Destructive

The Photoacoustic (PA) technique was used to investigate the structural properties (e.g. open porosity and permeability) of open-pore sintered glasses. This work demonstrates that the photoacoustic signal of open-pore sintered glasses, which are produced with different grain sizes and several degrees of open porosity, is sensitive to the morphology of the open-pore samples. The results obtained by the PA technique were related to results obtained by the Pressure Decay technique, and an excellent correlation was obtained. This demonstrates that PA technique, which is non-intrusive and non-destructive, is promising for application in analysis of porous ceramic structures, even if the sample is semi-transparent.

Determination of the pore size of woven structures through image analysis

2012 ◽  
Vol 2 (1) ◽  
Author(s):  
R. Angelova
Keyword(s):  
Pore Size ◽  
Single Layer ◽  
Woven Fabric ◽  
Virtual Model ◽  
Experimental Procedure ◽  
Porosity And Permeability ◽  
Woven Structures ◽  
Woven Structure ◽  
Non Destructive

AbstractThe paper presents an experimental procedure developed for determination of the pore size, shape and distribution in a single layer woven fabric, for the construction of a virtual model to be incorporated in a future CFD software package. The procedure is based on non-destructive observation and analysis of woven samples. 14 different samples of gray fabrics of 100 % cotton in plain and twill weaves are investigated. The results obtained allow the creation of reality more realistic virtual model of the woven structure, and theoretical investigation of its porosity and permeability through computer simulation.

Multi-Purpose Porous Ceramic Material

2018 ◽  
Vol 931 ◽  
pp. 594-597
Author(s):  
Yu.S. Bagaiskov
Keyword(s):  
Ceramic Material ◽  
Construction Material ◽  
Porous Ceramic ◽  
Ceramic Composites ◽  
Refractory Clay ◽  
Treatment Processes ◽  
Wide Range ◽  
Porosity And Permeability ◽  
And Performance ◽  
Criteria For Evaluation

The main criteria for evaluation of ceramic products’ properties are strength, structural and mechanical, and thermophysical properties. To produce ceramic composites with a wide range of structural, mechanical, strength, and performance properties depending on application, various additives (flux agents, sintering agents, fillers) and heat treatment processes are used. Studies to determine a rational mixture composition have been carried out. A multipurpose material, comprising particles of the basic chamotte filler (burned clay) with a bonding agent in the form of refractory clay from the Latnenskoye deposit with a field spar fluxing agent, an additional filler made of heat-resistant silicon carbide, and an adhesive component in the form of powdered dextrin, is suggested. According to the combination of its ensured parameters, the obtained ceramic material can be multipurpose. Its degree of porosity and permeability make the material filtering, sound-proofing, and heat-retaining; considering the low density, it can be used as a lightweight construction material.

Grain Growth during Annealing: Experiments and Modelling

2012 ◽  
Vol 715-716 ◽  
pp. 611-616 ◽  
Author(s):  
M. Candic ◽  
Bao Hui Tian ◽  
Christof Sommitsch
Keyword(s):  
Grain Growth ◽  
Second Phase ◽  
Excellent Correlation ◽  
Grain Sizes ◽  
Second Phase Particles ◽  
Different Temperatures ◽  
Grain Growth Kinetics ◽  
Parameter Approach ◽  
Annealing Experiments ◽  
Two Parameter

In the present work, for the description of grain coarsening, a probabilistic and a deterministic 2D cellular automaton simulation setup were developed. The results of the simulation have been validated by solution annealing experiments of austenitic stainless steel 304L (Fe-18Cr-8Ni) at different temperatures and times. Both cellular automata models show an excellent correlation between the experimental determined data and grain growth kinetics based upon considerations of temperature and second phase particles. Additionally, a two parameter approach of the probabilistic model was implemented, resulting in determining the grain sizes limiting normal and abnormal grains and accurate description of grain growth.

Scanning Near-Field Microwave Probe for In-line Metrology of Low-K Dielectrics

2004 ◽  
Vol 812 ◽  
Author(s):  
Vladimir V. Talanov ◽  
Robert L. Moreland ◽  
André Scherz ◽  
Andrew R. Schwartz ◽  
Youfan Liu
Keyword(s):  
Near Field ◽  
Spot Size ◽  
Excellent Correlation ◽  
K Value ◽  
Microwave Probe ◽  
Near Field Scanning ◽  
Non Destructive ◽  
Low K ◽  
Probe Measurements ◽  
Better Than

AbstractWe have developed a novel microwave near-field scanning probe technique for non-contact measurement of the dielectric constant of low-k films. The technique is non-destructive, noninvasive and can be used on both porous and non-porous dielectrics without any sample preparation. The probe has a few-micron spot size, which makes the technique well suited for real time low-k metrology on production wafers. For dielectrics with k<4 the precision and accuracy are better than 2% and 5%, respectively. Results for both SOD and CVD low-k films are presented and show excellent correlation with Hg-probe measurements. Results for k-value mapping on blanket 200mm wafers are presented as well.

Non-Destructive Inspection of Surface Integrity in Milled Turbine Blades of Inconel 738LC

2013 ◽  
Vol 486 ◽  
pp. 9-15 ◽  
Author(s):  
Kamil Kolařík ◽  
Zdenek Pala ◽  
Libor Beranek ◽  
Jiří Čapek ◽  
Zdenek Vyskocil ◽  
...  
Keyword(s):  
Residual Stresses ◽  
Surface Integrity ◽  
Turbine Blades ◽  
Mutual Effect ◽  
Work Piece ◽  
Machined Surface ◽  
Grain Sizes ◽  
Cutter Orientation ◽  
Inconel 738Lc ◽  
Non Destructive

Nickel super-alloys are widely used in aerospace as material for turbine blades. Unfortunately, their machining is difficult since mechanical hardening and, consequently, extreme tool wear occur. Casting can no longer meet the requirements for precision, hence, the castings are being ground or milled. In this contribution, a quality check of the milled surface by several surface integrity parameters is proposed with respect to the surface structural inhomogeneities caused by mutual effect of plastic deformations and thermal fields during the cutting process. Castings from Inconel 738LC were milled with cutting conditions chosen by Design-Of-Experiments method and the resulting surfaces were assessed by non-destructive X-ray diffraction methods in several areas corresponding to various cutter orientation and work-piece angle. Surface integrity was described by macroscopic residual stresses, microstrains, grain sizes and phase composition. Mostly, favourable compressive surface residual stresses were observed in the cutting direction, grain sizes were distinctively smaller when the tool axis was perpendicular to the machined surface.

STUDY OF THERMAL TRANSPORT PARAMETERS IN PbI2 SINGLE CRYSTAL USING A PHOTOACOUSTIC TECHNIQUE

2006 ◽  
Vol 20 (20) ◽  
pp. 1253-1260 ◽  
Author(s):  
D. S. AHLAWAT ◽  
D. MOHAN ◽  
S. K. GHOSHAL ◽  
R. D. SINGH ◽  
MEENAKSHI SHARMA
Keyword(s):  
Thermal Conductivity ◽  
Thermal Diffusivity ◽  
Single Crystal ◽  
Characteristic Frequency ◽  
Modulation Frequency ◽  
Thermal Effusivity ◽  
Photoacoustic Signal ◽  
Photoacoustic Technique ◽  
Front Side ◽  
Transport Parameters

The present work discusses the study of the transport properties of the PbI 2 single crystal using an indigenously developed photoacoutistic spectrometer. The amplitude photoacoustic signal, being a function of the modulation frequency of the incident optical beam, has been measured by using the front-side detection configuration. The characteristic frequency (fc) of the single crystal has been found to be 55 Hz. The values of thermal diffusivity, thermal conductivity and thermal effusivity in the case of PbI 2 have been derived experimentally. Their values have been compared with the values reported in a case which studied other materials in the literature. Thermal diffusion lengths have also been calculated at different chopping frequencies from 15 Hz to 90 Hz.

The effect of UV and thermally induced oxidation on the surface and structural properties of CVD diamond layers with different grain sizes

2021 ◽  
pp. 108739
Author(s):  
Anna Dychalska ◽  
Marek Trzcinski ◽  
Kazimierz Fabisiak ◽  
Kazimierz Paprocki ◽  
Wojciech Koczorowski ◽  
...  
Keyword(s):  
Structural Properties ◽  
Cvd Diamond ◽  
Thermally Induced ◽  
Grain Sizes

Non-Destructive Evaluation of Synthetic Tissue Scaffolds With NMR

1998 ◽  
Vol 550 ◽  
Author(s):  
L. Garrido
Keyword(s):  
Open Porosity ◽  
Casting Technique ◽  
Biodegradable Scaffolds ◽  
Porous Matrices ◽  
Magnetic Resonance Imaging Mri ◽  
Non Destructive ◽  
Good Agreement ◽  
Proton Magnetic Resonance Imaging

AbstractProton magnetic resonance imaging (MRI) is applied to determine non–destructively the open porosity of biodegradable scaffolds of poly(3–hydroxybutyrate-–3–hydroxyvalerate) in vitro and tissue infiltration in vivo. Porous matrices with copolymers having 12% and 24% 3–hydroxyvalerate (HV) are prepared using a solvent casting technique. The results of open porosity P(%) measured by MRI (PMRI) show good agreement with those obtained by gravimetry analysis (PGA). Thus, for scaffolds with 12% HV, PMRI = 91.0 ±1.0 (mean ± s.d.) and PGA = 88.0 ± 0.75; and for those with 24% HV, PMRI = 89.4 ±1.3 and PGA = 88.8 ± 1.0. Also, the extent of tissue infiltration in these scaffolds determined by MRI in vivo was similar to that observed by histology. These results illustrate the potential of MRI methods for investigating the behavior of biodegradable scaffolds non-invasively in applications for tissue engineering.

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