Focus variation technology as a tool for tissue surface characterization

Abstract The surface of tissue paper is relatively complex compared to other paper grades and consists of several overlapping structures like protruding fibres, crepe and fabric-based patterns at different spatial frequencies. The knowledge of tissue surface characteristics is crucial when it comes to improvement with respect to surface softness and the perceptual handfeel of tissue products. In this work we used the optical based, non-contact measurement principle of focus variation for surface characterization of dry-creped, textured and through air dried (TAD) tissue. Based on the three tissue grades, a procedure which includes the characterization of the whole tissue surface throughout different scales within one setup, was developed. Surprisingly, focus variation was rarely used in tissue-related research, as it provides robust and reliable 3D surface information which can be used for further areal surface analysis. Special attention was given to the preparation and discussion of the raw data up to the final analysis including several spatial filtering steps. Enhanced surface parameters like the developed interfacial area ratio (Sdr) and the power spectral density (PSD) were used to describe the surface adequately. The surface roughness of the three tissue grades was compared, with the textured tissue showing the highest roughness in Sdr and PSD analysis. Although both methods are based on different principles, a high correlation in terms of evaluated roughness is evident. Regular structures like crepe and patterns are obtainable as peaks at the respective frequency with a certain intensity in the PSD evaluation. Apart from topography in terms of structures and roughness, the wide field of view of the focus variation measurement also allows assessment of effects related to flocculation and sheet formation. The developed procedure could also be appropriate for other fibre based materials and/or fabrics, which are similar to tissue with respect to optical properties such as for example nonwovens. Graphic abstract

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Post-Processing and Surface Characterization of Additively Manufactured Stainless Steel 316L Lattice: Implications for BioMedical Use

Materials ◽

10.3390/ma14061376 ◽

2021 ◽

Vol 14 (6) ◽

pp. 1376

Author(s):

Alex Quok An Teo ◽

Lina Yan ◽

Akshay Chaudhari ◽

Gavin Kane O’Neill

Keyword(s):

Surface Roughness ◽

Stainless Steel ◽

Surface Characterization ◽

High Surface ◽

Surface Characteristics ◽

Post Processing ◽

Stainless Steel 316L ◽

Processing Methods ◽

Particulate Debris

Additive manufacturing of stainless steel is becoming increasingly accessible, allowing for the customisation of structure and surface characteristics; there is little guidance for the post-processing of these metals. We carried out this study to ascertain the effects of various combinations of post-processing methods on the surface of an additively manufactured stainless steel 316L lattice. We also characterized the nature of residual surface particles found after these processes via energy-dispersive X-ray spectroscopy. Finally, we measured the surface roughness of the post-processing lattices via digital microscopy. The native lattices had a predictably high surface roughness from partially molten particles. Sandblasting effectively removed this but damaged the surface, introducing a peel-off layer, as well as leaving surface residue from the glass beads used. The addition of either abrasive polishing or electropolishing removed the peel-off layer but introduced other surface deficiencies making it more susceptible to corrosion. Finally, when electropolishing was performed after the above processes, there was a significant reduction in residual surface particles. The constitution of the particulate debris as well as the lattice surface roughness following each post-processing method varied, with potential implications for clinical use. The work provides a good base for future development of post-processing methods for additively manufactured stainless steel.

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Analysis of Surface Microgeometry Created by Electric Discharge Machining

Materials ◽

10.3390/ma13173830 ◽

2020 ◽

Vol 13 (17) ◽

pp. 3830

Author(s):

Tomasz Bartkowiak ◽

Michał Mendak ◽

Krzysztof Mrozek ◽

Michał Wieczorowski

Keyword(s):

Curvature Tensor ◽

Electric Discharge ◽

Surface Characterization ◽

Tensor Analysis ◽

Principal Curvatures ◽

Motif Analysis ◽

Electric Discharge Machining ◽

Surface Microgeometry ◽

Focus Variation

The objective of this work is to study the geometric properties of surface topographies of hot-work tool steel created by electric discharge machining (EDM) using motif and multiscale analysis. The richness of these analyses is tested through calculating the strengths of the correlations between discharge energies and resulting surface characterization parameters, focusing on the most representative surface features—craters, and how they change with scale. Surfaces were created by EDM using estimated energies from 150 to 9468 µJ and measured by focus variation microscope. The measured topographies consist of overlapping microcraters, of which the geometry was characterized using three different analysis: conventional with ISO parameters, and motif and multiscale curvature tensor analysis. Motif analysis uses watershed segmentation which allows extraction and geometrically characterization of each crater. Curvature tensor analysis focuses on the characterization of principal curvatures and their function and their evolution with scale. Strong correlations (R2 > 0.9) were observed between craters height, diameter, area and curvature using linear and logarithmic regressions. Conventional areal parameter related to heights dispersion were found to correlate stronger using logarithmic regression. Geometric characterization of process-specific topographic formations is considered to be a natural and intuitive way of analyzing the complexity of studied surfaces. The presented approach allows extraction of information directly relating to the shape and size of topographic features of interest. In the tested conditions, the surface finish is mostly affected and potentially controlled by discharge energy at larger scales which is associated with sizes of fabricated craters.

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Surface Characterization of an Extruded 6060 Al Alloy

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.29-30.67 ◽

2007 ◽

Vol 29-30 ◽

pp. 67-70

Author(s):

Wei Zhang ◽

Jim Metson ◽

C.L. Nguyen ◽

S. Chen

Keyword(s):

Aluminium Alloy ◽

Photoelectron Spectroscopy ◽

Surface Characterization ◽

Extrusion Direction ◽

Surface Characteristics ◽

Al Alloy ◽

X Ray ◽

Film Instability ◽

Mg Content

The surface characteristics of an extruded 6060 aluminium alloy were investigated with X-ray Photoelectron Spectroscopy (XPS). The results revealed that the extruded surface was covered by oxides of aluminium and magnesium. The thickness of aluminium oxide was found to change along the extrusion direction with the thinnest and thickest oxide at the beginning and end of the extrudate, respectively. Magnesium segregation was found on the surface of the extrusion with the highest and lowest Mg concentration at the beginning and end of the extrudate, respectively. This is the inverse result of that expected where increasing Mg content was believed to be associated with film instability and thicker films.

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EDM Surface Characterization of a Ceramic Composite TiB2/SiC

Journal of Engineering Materials and Technology ◽

10.1115/1.2904123 ◽

1991 ◽

Vol 113 (4) ◽

pp. 437-442 ◽

Cited By ~ 17

Author(s):

M. Ramulu ◽

J. L. Garbini

Keyword(s):

Electrical Discharge ◽

Surface Characterization ◽

Ceramic Composite ◽

Surface Characteristics ◽

Power Input ◽

Recast Layer ◽

Electrically Conductive ◽

The Individual ◽

Edm Process

Electrical Discharge Machined (EDM) hole surface characteristics of 20 percent Titanium diboride (TiB2) particulate and Silicon carbide (SiC) matrix composite material were investigated. The EDM hole surfaces produced by using brass, copper and graphite were examined by scanning electron microscopy (SEM) and surface profilometry to determine the surface characteristics. As-machined surfaces showed the microcracks in the recast layer, and the individual TiB2 grains were exposed on the surface. The depth of the recast structure on the surface has varied from 8 μm to less than a micrometer and was approximately proportional to the amount of impinging energy or power input. The EDM process appears to be a promising method of producing an excellent surface in electrically conductive TiB2/SiC composite under slow cutting conditions.

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Surface and aerosol retrieval from S5P and S4: baseline requirements and expected performance

10.5194/egusphere-egu2020-19158 ◽

2020 ◽

Author(s):

Pavel Litvinov ◽

Oleg Dubovik ◽

Cheng Chen ◽

Anton Lopatin ◽

Tatyana Lapionak ◽

...

Keyword(s):

Spectral Range ◽

Surface Characterization ◽

Surface Characteristics ◽

Trace Gas ◽

Inversion Algorithm ◽

Earth Observations ◽

Expected Performance ◽

Infrared Spectral ◽

Important Input

Sentinel-4 and Sentinel-5p instruments provide hyperspectral measurements in UV, VIS and infrared spectral range. Though the main purpose of the satellites is trace gas characterization, both instruments are capable of aerosol and surface characterization. In particular, S4 and S5p measurements in UV have unique information about absorption and elevation properties of aerosol. Moreover, measurements in wide spectral range are very sensitive to aerosol size and surface type. On one hand, aerosol and surface characteristics are important input parameters for different trace gases such as ozone, NO2, BrO, CH2O, H2O, CO2, CO, and CH4. On another hand, aerosol and surface characteristics are very important on their own for climate studies, air pollution and surface monitoring.The quantitative characterization of aerosol (AOD (Aerosol Optical Depth), aerosol type) and surface properties (BRDF (Bidirectional Reflectance Distribution Function)) from Sentinel-4 and Sentinel-5p instruments is a topic for several ESA/EUMETSAT projects. In particular, in the framework of S5P+I AOD/BRDF project an innovative algorithm will be developed which integrates the advanced GRASP algorithm (Dubovik et al. 2011, 2014) with the heritage AOD and DLER algorithm previously applied to TOMS, GOME(-2), SCIAMACHY and OMI sensors (Tilstra et al., 2017). Innovative GRASP algorithm is expected to provide surface BRDF and AOD with the accuracy required by most trace gas retrieval algorithms.Here the requirements on aerosol and surface characterization from S4 and S5p instruments will be analyzed. On the basis of inversion results from the synthetic (S4) and real (S5p) measurements we discuss how expected AOD and BRDF accuracy from the innovative and GRASP/S4 algorithms meet these requirements. New advanced possibility of aerosol and surface characterization with GRASP from S5p instrument will be discussed.References<ol><li>Dubovik, O., et al., &#8220;Statistically optimized inversion algorithm for enhanced retrieval of aerosol properties from spectral multi-angle polarimetric satellite observations&#8221;, Atmos. Meas. Tech., 4, 975-1018, 2011.</li> <li>Dubovik, O., et al. &#8220;GRASP: a versatile algorithm for characterizing the atmosphere&#8221;, SPIE: Newsroom, doi:10.1117/2.1201408.005558, Published Online: http://spie.org/x109993.xml, September 19, 2014.</li> <li>Tilstra, L. G., et al., &#8220;Surface reflectivity climatologies from UV to NIR determined from Earth observations by GOME-2 and SCIAMACHY&#8221;, J. Geophys. Res. Atmos., 122, 4084&#8211;4111.</li> </ol>

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Surface Roughness Characterization of ZnO: TiO2-Organic Blended Solar Cells Layers by Atomic Force Microscopy and Fractal Analysis

International Journal of Nanoscience ◽

10.1142/s0219581x14500203 ◽

2014 ◽

Vol 13 (03) ◽

pp. 1450020 ◽

Cited By ~ 6

Author(s):

Ştefan Ţălu ◽

Sebastian Stach ◽

Muhammad Ikram ◽

Dinesh Pathak ◽

Tomas Wagner ◽

...

Keyword(s):

Surface Roughness ◽

Atomic Force Microscopy ◽

Solar Cells ◽

Fractal Analysis ◽

Surface Characterization ◽

Surface Characteristics ◽

Statistical Parameters ◽

Force Microscopy ◽

Atomic Force

The objective of this work is to quantitatively characterize the 3D complexity of ZnO : TiO 2-organic blended solar cells layers by atomic force microscopy and fractal analysis. ZnO : TiO 2-organic blended solar cells layers were investigated by AFM in tapping-mode in air, on square areas of 25 μm2. A detailed methodology for ZnO : TiO 2-organic blended solar cells layers surface fractal characterization, which may be applied for AFM data, is presented. Detailed surface characterization of the surface topography was obtained using statistical parameters, according with ISO 25178-2: 2012. The fractal dimensions Df values (all with average ± standard deviation), obtained with morphological envelopes method, for: blend D1 ( P 3 HT : PCBM : ZnO : TiO 2 blend with ratio 1:0.35:0.175:0.175 mg in 1 ml of Chlorobenzene) is Df = 2.55 ± 0.01; and for blend D2 ( P 3 HT : PCBM : ZnO : TiO 2 blend with ratio 1:0.55:0.075:0.075 mg in 1 ml of Chlorobenzene) is Df = 2.45 ± 0.01. Denoting the ratios in 1 ml of Chlorobenzene with D1 and D2 articles. The 3D surface roughness of samples revealed a fractal structure at nanometer scale. Fractal and AFM analysis may assist manufacturers in developing ZnO : TiO 2-organic blended solar cells layers with better surface characteristics and provides different yet complementary information to that offered by traditional surface statistical parameters.

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The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100071107 ◽

1973 ◽

Vol 31 ◽

pp. 132-133 ◽

Cited By ~ 1

Author(s):

R. E. Herfert

Keyword(s):

Surface Characterization ◽

Analytical Techniques ◽

X Ray Diffraction ◽

Depth Of Penetration ◽

X Ray ◽

The Past ◽

Transmission Electron ◽

Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

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