Perceived Glossiness: Beyond Surface Properties

Gloss is widely accepted as a surface- and illuminationbased property, both by definition and by means of metrology. However, mechanisms of gloss perception are yet to be fully understood. Potential cues generating gloss perception can be a product of phenomena other than surface reflection and can vary from person to person. While human observers are less likely to be capable of inverting optics, they might also fail predicting the origin of the cues. Therefore, we hypothesize that color and translucency could also impact perceived glossiness. In order to validate our hypothesis, we conducted series of psychophysical experiments asking observers to rank objects by their glossiness. The objects had the identical surface geometry and shape but different color and translucency. The experiments have demonstrated that people do not perceive objects with identical surface equally glossy. Human subjects are usually able to rank objects of identical surface by their glossiness. However, the strategy used for ranking varies across the groups of people.

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On the aspect ratio of ’Oumuamua : less elongated shape for irregular surface properties

Monthly Notices of the Royal Astronomical Society ◽

10.1093/mnras/staa252 ◽

2020 ◽

Vol 493 (2) ◽

pp. 1546-1552 ◽

Cited By ~ 2

Author(s):

Allona Vazan ◽

Re’em Sari

Keyword(s):

Aspect Ratio ◽

Light Curve ◽

Surface Properties ◽

Specular Reflection ◽

Orientation Distribution ◽

Brightness Variation ◽

Spin Axis ◽

Isotopic Spin ◽

Axis Orientation ◽

Surface Reflection

ABSTRACT The large brightness variation in the observed light curve of ’Oumuamua is probably related to its shape, i.e. to the ratio between its longest axis and its shortest axis (aspect ratio). Several approaches found the aspect ratio of ’Oumuamua to be unusually elongated. Moreover, the spin axis orientation has to be almost perpendicular to the observer in order to obtain such an extreme light curve, a configuration which is unlikely. However, interstellar ’Oumuamua may have different surface properties than we know in our Solar system. Therefore, in this work we widen the parameter space for surface properties beyond the asteroid-like models and study its effect on ’Oumuamua’s light curve. We calculate reflection from a rotating ellipsoidal object for four models: Lambertian reflection, specular reflection, single scattering diffusive, and backscatter . We then calculate the probability to obtain a light-curve ratio larger than the observed, as a function of the object’s aspect ratio, assuming an isotopic spin orientation distribution. We find the elongation of ’Oumuamua to be less extreme for the Lambertian and specular reflection models. Consequently, the probability to observe the light-curve ratio of ’Oumuamua given its unknown spin axis orientation is larger for those models. We conclude that different surface reflection properties may suggest alternatives to the extreme shape of ’Oumuamua , relieving the need for complicated formation scenario, extreme albedo variation, or unnatural origin. Although the models suggested here are for ideal ellipsoidal shape and ideal reflection method, the results emphasize the importance of surface properties for the derived aspect ratio.

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Tactile perception of the roughness of 3D-printed textures

Journal of Neurophysiology ◽

10.1152/jn.00564.2017 ◽

2018 ◽

Vol 119 (3) ◽

pp. 862-876 ◽

Cited By ~ 5

Author(s):

Chelsea Tymms ◽

Denis Zorin ◽

Esther P. Gardner

Keyword(s):

Surface Roughness ◽

High Resolution ◽

3D Printing ◽

Human Subjects ◽

Three Dimensional ◽

Weber Fraction ◽

Parametric Modeling ◽

Surface Geometry ◽

Surface Parameters ◽

Roughness Perception

Surface roughness is one of the most important qualities in haptic perception. Roughness is a major identifier for judgments of material composition, comfort, and friction and is tied closely to manual dexterity. Some attention has been given to the study of roughness perception in the past, but it has typically focused on noncontrollable natural materials or on a narrow range of artificial materials. The advent of high-resolution three-dimensional (3D) printing technology provides the ability to fabricate arbitrary 3D textures with precise surface geometry to be used in tactile studies. We used parametric modeling and 3D printing to manufacture a set of textured plates with defined element spacing, shape, and arrangement. Using active touch and two-alternative forced-choice protocols, we investigated the contributions of these surface parameters to roughness perception in human subjects. Results indicate that large spatial periods produce higher estimations of roughness (with Weber fraction = 0.19), small texture elements are perceived as rougher than large texture elements of the same wavelength, perceptual differences exist between textures with the same spacing but different arrangements, and roughness equivalencies exist between textures differing along different parameters. We posit that papillary ridges serve as tactile processing units, and neural ensembles encode the spatial profiles of the texture contact area to produce roughness estimates. The stimuli and the manufacturing process may be used in further studies of tactile roughness perception and in related neurophysiological applications. NEW & NOTEWORTHY Surface roughness is an integral quality of texture perception. We manufactured textures using high-resolution 3D printing, which allows precise specification of the surface spatial topography. In human psychophysical experiments we investigated the contributions of specific surface parameters to roughness perception. We found that textures with large spatial periods, small texture elements, and irregular, isotropic arrangements elicit the highest estimations of roughness. We propose that roughness correlates inversely with the total contacted surface area.

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Femtosecond Laser Micro-/Nano-Texturing of Stainless Steels for Surface Property Control

Micromachines ◽

10.3390/mi10080512 ◽

2019 ◽

Vol 10 (8) ◽

pp. 512 ◽

Cited By ~ 3

Author(s):

Aizawa ◽

Inohara ◽

Wasa

Keyword(s):

Contact Angle ◽

Fractal Dimension ◽

Femtosecond Laser ◽

Surface Properties ◽

Stainless Steels ◽

Surface Property ◽

Textured Surface ◽

Surface Geometry ◽

Static Contact ◽

Property Control

Surface geometry has had an influence on the surface property, in addition to the intrinsic surface energy, of materials. Many physical surface modification methods had been proposed to control the solid surface geometry for modification of surface properties. Recently, short-pulse lasers were utilized to perform nano-texturing onto metallic and polymer substrates for the improvement of surface properties. Most of the papers reported that the hydrophilic metallic surface was modified to have a higher contact angle than 120–150°. Little studies explained the relationship between surface geometry and surface properties. In the present study, the laser micro-/nano-texturing was developed to describe this surface-geometric effect on the static contact angles for pure water. Micropatterns with multi spatial frequencies are designed and synthesized into a microtexture. This tailored microtexture was utilized to prepare for computer aided machining (CAM) data to control the femtosecond laser beams. The nano-length ripples by laser induced periodic surface structuring (LIPSS) supposed onto this microtexture to form the micro-/nano-texture on the AISI304 substrate surface. Computational geometry was employed to describe this geometric profile. The fractal dimension became nearly constant by 2.26 and insensitive to increase of static contact angle (θ) for θ > 150°. Under this defined self-similarity, the micro-/nano-textured surface state was controlled to be super-hydrophobic by increasing the ratio of the highest spatial frequency in microtextures to the lowest one. This controllability of surface property on the stainless steels was supported by tailoring the wavelength and pitch of microtextures. Exposure testing was also used to evaluate the engineering durability of this micro-/nano-textured surface. Little change of the measured fractal dimension during the testing proved that this physically modified AISI304 surface had sufficient stability for its long-term usage in air.

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Bioresorbable polymeric materials – current state of knowledge

Polimery ◽

10.14314/polimery.2021.1.1 ◽

2021 ◽

Vol 66 (1) ◽

pp. 3-10

Author(s):

Kamila Wiśniewska ◽

Zbigniew Rybak ◽

Marcin Wątrobiński ◽

Marcin H. Struszczyk ◽

Jarosław Filipiak ◽

...

Keyword(s):

Surface Properties ◽

Biodegradable Polymers ◽

Tissue Regeneration ◽

Bone Healing ◽

Polymeric Materials ◽

Surface Geometry ◽

Current State ◽

Variable Surface

Bioresorbable materials are used in medicine for fi xing, correcting or stabilizing bones in various anatomical areas, and the market for such materials is growing rapidly worldwide. The use of polymers for their production is associated with the ability to control their properties. They are prepared from bioresorbable materials with variable surface, geometry, porosity, as well as mechanical and surface properties. They support bone healing and are suitable for tissue regeneration due to their biodegradability and biocompatibility. We believe that materials from biodegradable polymers will play an increasingly important role in future medicine.

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Effects of a synthetic lung surfactant on pharyngeal patency in awake human subjects

Journal of Applied Physiology ◽

10.1152/jappl.1997.82.1.78 ◽

1997 ◽

Vol 82 (1) ◽

pp. 78-85 ◽

Cited By ~ 30

Author(s):

T. Van Der Touw ◽

A. B. H. Crawford ◽

J. R. Wheatley

Keyword(s):

Surface Tension ◽

Surface Properties ◽

Human Subjects ◽

Lung Surfactant ◽

Supraglottic Airway ◽

Electromyographic Activity ◽

X Ray ◽

Surfactant Preparation ◽

Pharyngeal Diameter ◽

Adhesive Forces

Van der Touw, T., A. B. H. Crawford, and J. R. Wheatley.Effects of a synthetic lung surfactant on pharyngeal patency in awake human subjects. J. Appl. Physiol. 82(1): 78–85, 1997.—We examined the effects of separate applications of saline and a synthetic lung surfactant preparation (Surf; Exosurf Neonatal) into the supraglottic airway (SA) on the anteroposterior pharyngeal diameter ( Dap) and the airway pressures required to close (Pcl) and reopen (Pop) the SA in five awake normal supine subjects. Dap, Pcl, and Pop were determined during lateral X-ray fluoroscopy and voluntary glottic closure when pressure applied to the SA lumen was decreased from 0 to −20 cmH2O and then increased to +20 cmH2O. After Surf application and relative to control, Dapwas larger for most of the applied pressures, Pcl decreased (−12.3 ± 1.9 to −18.7 ± 0.9 cmH2O; P < 0.01), Pop decreased (13.4 ± 1.9 to −6.0 ± 3.4 cmH2O; P < 0.01), and genioglossus electromyographic activity did not change ( P > 0.05). Saline had no effect. These observations suggest that pharyngeal intraluminal surface properties are important in maintaining pharyngeal patency. We propose that surfactants enhance pharyngeal patency by reducing surface tension and adhesive forces acting on intraluminal SA surfaces.

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Review of Friction and Surface Properties of Snakeskin

Handbook of Research on Biomimetics and Biomedical Robotics - Advances in Computational Intelligence and Robotics ◽

10.4018/978-1-5225-2993-4.ch012 ◽

2018 ◽

pp. 276-315

Author(s):

Hisham A. Abdel-Aal

Keyword(s):

Surface Properties ◽

Surface Engineering ◽

Surface Geometry ◽

Design Features ◽

Surface Design ◽

Technical Problems ◽

Natural Systems ◽

Biological World ◽

Diverse Habitat

Locomotion is an essential activity in the biological world. Friction affects the energy invested in motion. Natural systems tend to conserve energy. As such, it is necessary to mitigate the effects of friction. There are many intriguing examples of creatures where dynamics of motion and surface geometry (macro and micro) combine to optimize the tribological profile. One example is that of snakes. In snakes, texturing geometries and topologies specifically contribute to frictional mitigation in a variety of situations. Snakes are found everywhere on earth. Their diverse habitat presents a broad range of tribological environments. This requires customized surface design features that potentially can inspire deterministic solutions for many technical problems. Therefore, they have attracted attention lately. Many, from surface engineering to robotics, have started to study their tribological response and frictional characteristics. This chapter attempts to review the major findings about the tribology of the legless reptiles obtained through the last two decades.

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Biological and Surface Properties of C-Type Virus Particles Produced by Novikoff Ascites Hepatoma Cells

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100079395 ◽

1977 ◽

Vol 35 ◽

pp. 388-389

Author(s):

D.C. Hixson ◽

J.C. Chan ◽

J.M. Bowen ◽

E.F. Walborg

Keyword(s):

Surface Properties ◽

Ricinus Communis ◽

Rat Kidney ◽

Leukemia Virus ◽

Viral Envelope ◽

Virus Particles ◽

Chemically Induced ◽

Sarcoma Virus ◽

Hepatocarcinoma Cells ◽

Type C

Several years ago Karasaki (1) reported the production of type C virus particles by Novikoff ascites hepatocarcinoma cells. More recently, Weinstein (2) has reported the presence of type C virus particles in cell cultures derived from transplantable and primary hepatocellular carcinomas. To date, the biological function of these virus and their significance in chemically induced hepatocarcinogenesis are unknown. The present studies were initiated to determine a possible role for type C virus particles in chemically induced hepatocarcinogenesis. This communication describes results of studies on the biological and surface properties of type C virus associated with Novikoff hepatocarcinoma cells.Ecotropic and xenotropic murine leukemia virus (MuLV) activity in ascitic fluid of Novikoff tumor-bearing rats was assayed in murine sarcoma virus transformed S+L- mouse cells and S+L- mink cells, respectively. The presence of sarcoma virus activity was assayed in non-virus-producing normal rat kidney (NRK) cells. Ferritin conjugates of concanavalin A (Fer-Con wheat germ agglutinin (Fer-WGA), and Ricinus communis agglutinins I and II (Fer-RCAI and Fer-RCAII) were used to probe the structure and topography of saccharide determinants present on the viral envelope.

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Inelastic scattering at surfaces and interfaces

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100143560 ◽

1986 ◽

Vol 44 ◽

pp. 392-393

Author(s):

R. H. Ritchie ◽

A. Howie

Keyword(s):

Inelastic Scattering ◽

Surface Properties ◽

Correlation Energy ◽

Condensed Matter ◽

Charged Particles ◽

Condensed Matter Physics ◽

Optical Phonons ◽

Exchange Correlation ◽

Surfaces And Interfaces ◽

Inelastic Interactions

An important part of condensed matter physics in recent years has involved detailed study of inelastic interactions between swift electrons and condensed matter surfaces. Here we will review some aspects of such interactions.Surface excitations have long been recognized as dominant in determining the exchange-correlation energy of charged particles outside the surface. Properties of surface and bulk polaritons, plasmons and optical phonons in plane-bounded and spherical systems will be discussed from the viewpoint of semiclassical and quantal dielectric theory. Plasmons at interfaces between dissimilar dielectrics and in superlattice configurations will also be considered.

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Elevated level of circulatory sTLT1 induces inflammation through SYK/MEK/ERK signalling in coronary artery disease

Clinical Science ◽

10.1042/cs20190999 ◽

2019 ◽

Vol 133 (22) ◽

pp. 2283-2299

Author(s):

Apabrita Ayan Das ◽

Devasmita Chakravarty ◽

Debmalya Bhunia ◽

Surajit Ghosh ◽

Prakash C. Mandal ◽

...

Keyword(s):

Risk Factors ◽

Coronary Artery Disease ◽

Coronary Artery ◽

Chronic Inflammation ◽

Ex Vivo ◽

Human Subjects ◽

Critical Role ◽

Atherosclerotic Cardiovascular Disease ◽

Tnf Α ◽

Artery Disease

Abstract The role of inflammation in all phases of atherosclerotic process is well established and soluble TREM-like transcript 1 (sTLT1) is reported to be associated with chronic inflammation. Yet, no information is available about the involvement of sTLT1 in atherosclerotic cardiovascular disease. Present study was undertaken to determine the pathophysiological significance of sTLT1 in atherosclerosis by employing an observational study on human subjects (n=117) followed by experiments in human macrophages and atherosclerotic apolipoprotein E (apoE)−/− mice. Plasma level of sTLT1 was found to be significantly (P<0.05) higher in clinical (2342 ± 184 pg/ml) and subclinical cases (1773 ± 118 pg/ml) than healthy controls (461 ± 57 pg/ml). Moreover, statistical analyses further indicated that sTLT1 was not only associated with common risk factors for Coronary Artery Disease (CAD) in both clinical and subclinical groups but also strongly correlated with disease severity. Ex vivo studies on macrophages showed that sTLT1 interacts with Fcɣ receptor I (FcɣRI) to activate spleen tyrosine kinase (SYK)-mediated downstream MAP kinase signalling cascade to activate nuclear factor-κ B (NF-kB). Activation of NF-kB induces secretion of tumour necrosis factor-α (TNF-α) from macrophage cells that plays pivotal role in governing the persistence of chronic inflammation. Atherosclerotic apoE−/− mice also showed high levels of sTLT1 and TNF-α in nearly occluded aortic stage indicating the contribution of sTLT1 in inflammation. Our results clearly demonstrate that sTLT1 is clinically related to the risk factors of CAD. We also showed that binding of sTLT1 with macrophage membrane receptor, FcɣR1 initiates inflammatory signals in macrophages suggesting its critical role in thrombus development and atherosclerosis.

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