Observation of Surface Structure of Kyo-Kawara (Ceramic Material for Roof Component) Fabricated by Traditional Skillful Technique

2011 ◽  
Author(s):  
Masahisa Asada ◽  
Masaki Sakata ◽  
Takeshi Shiono ◽  
Yuka Takai ◽  
Akihiko Goto ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Water Absorption ◽  
Surface Structure ◽  
Ceramic Material ◽  
Surface Characteristics ◽  
Structure And Properties ◽  
Roof Tile ◽  
The Relationship ◽  
Made In

Kyo-gawara is one of traditional crafts, one of Japanese roof tile made in Kyoto by using traditional techniques. The characteristics of Kyo-gawara is gloss on surface available in “Migaki” process. Migaki process is that craftsman strokes half-dry surface with paddle one by one. Number of products that a craftsman has to finish the process is decided. In previous study, investigation about the relationship between number of times of Migaki process and surface properties of Kyo-gawara cannot be seen [1]. In this study, specimens having different number of time of Migaki process (none, once, twice) were used, surface structure and properties were analyzed, and investigation about the relationship between Migaki process and surface characteristics was performed. Measurement items are surface roughness (Ra), contact angle, water absorption. As a result, surface roughness tended to decrease, and with increase of number of times of Migaki process. From the result of measurement of contact angle and water absorption, it was clarified that Migaki could improve waterproofness.

Relating Surface Roughness to Subsurface Stress

2005 ◽  
Author(s):  
A. Martini ◽  
S. B. Liu ◽  
B. Escoffier ◽  
Q. Wang
Keyword(s):  
Surface Roughness ◽  
Stress Field ◽  
Point Contact ◽  
Surface Characteristics ◽  
Operating Conditions ◽  
Surface Design ◽  
Dry Contact ◽  
Subsurface Stress ◽  
The Relationship ◽  
Machined Surfaces

Understanding and anticipating the effects of surface roughness on subsurface stress in the design phase can help ensure that performance and life requirements are satisfied. The specific approach taken in this work to address the goal of improved surface design is to relate surface characteristics of real, machined surfaces to subsurface stress fields for dry contact. This was done by digitizing machined surfaces, simulating point contact numerically, calculating the corresponding subsurface stress field, and then relating stress results back to the surface. The relationship between surface characteristics and subsurface stress is evaluated using several different approaches including analyses of trends identified through stress field visualization and extraction of statistical data. One such approach revealed a sharp transition between cases in which surface characteristics dominated the stress field and those in which bulk, or global contact effects dominated the stress. This transition point was found to be a function of the contact operating conditions, material properties, and most interestingly, the roughness of the surface.

Design of seal ring with rectangular grooves for gas isolation in Nanoimprint Lithography

2018 ◽  
Vol 233 (3) ◽  
pp. 1079-1086
Author(s):  
Peng Wei ◽  
Ma Liuhong ◽  
Li Mengke ◽  
Zhong Yinghui ◽  
Shangguan Lei ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Simple Model ◽  
Nanoimprint Lithography ◽  
Compressed Air ◽  
Comsol Multiphysics ◽  
Width Ratio ◽  
Seal Ring ◽  
The Cost ◽  
The Relationship

The prominent seal ring has been studied to prevent the compressed air from entering the enclosed area of the mold and the wafer and protect pattern in Compressional Gas Cushion Press Nanoimprint Lithography (CGCP NIL). In this paper, a non-salient seal ring with rectangular grooves was proposed to replace the prominent one, which achieved the same effect. The relationship between the width of seal ring and other three factors—the contact surface properties, the height of printed liquid, and the contact angle—was also investigated. The non-salient seal ring can be effective in sealing out the compressed air, on condition that the seal ring was wide enough. Besides, the width to meet the requirements reduced significantly, with increasing the roughness. Furthermore, the rectangular grooves etched on the seal ring can increase its surface roughness and the depth–width ratio was larger, surface roughness was bigger. Owing to the presence of rectangular grooves, smaller width was required to reach the same effect of leak-proof in the process. Besides, a simple model of COMSOL Multiphysics was established to verify the correctness of proposal. This work will greatly reduce the cost of the mold and guide the production of the mold in CGCP NIL.

Influence of paper properties on adhesive strength of starch gluing

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Claudia Anna Dohr ◽  
Ulrich Hirn
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Main Parameter ◽  
External Pressure ◽  
Liquid Penetration ◽  
Surface Wetting ◽  
Paper Properties ◽  
Substantial Correlation ◽  
The Relationship ◽  
Effect Of Surface

Abstract The effect of paper properties on the strength of starch gluing for Kraft sack papers has been investigated. We analyzed the effect of surface roughness, wettability and glue penetration. Surface roughness was found not to be related to gluing strength, also surface wetting measured by contact angle showed only a weak relation. Liquid penetration measured by ultrasound (ULP) was found to have a substantial correlation to gluing strength. Comparing ULP liquid penetration speed with actual glue uptake during the gluing process we found that they are only moderately connected. We are attributing this to the fact that the penetration and spreading of the glue on the paper is driven by applying an external pressure during the gluing process, which is not the case for the liquid penetration measurement. Investigating how asymmetrical glue penetration affects gluing strength we found that the relationship was low. The best indication for gluing strength turned out to be the surface wetting/substrate swelling parameter from the ultrasonic liquid penetration measurement. We conclude that the main parameter capturing gluing strength combines the influence of fiber wetting and penetration of the glue into the fibers.

scholarly journals Effects of Various Polishing Techniques on the Surface Characteristics of the Ti-6Al-4V Alloy and on Bacterial Adhesion

Coatings ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1057
Author(s):  
Yu-Ting Jhong ◽  
Chih-Yeh Chao ◽  
Wei-Chun Hung ◽  
Je-Kang Du
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Oxygen Content ◽  
Laser Scanning ◽  
Surface Characteristics ◽  
Surface Oxygen ◽  
X Ray ◽  
Electrolytic Polishing ◽  
Surface Contact ◽  
Surface Contact Angle

Ti-6Al-4V, although widely used in dental materials, causes peri-implant inflammation due to the long-term accumulation of bacteria around the implant, resulting in bone loss and eventual failure of the implant. This study aims to overcome the problem of dental implant infection by analyzing the influence of Ti-6Al-4V surface characteristics on the quantity of accumulated bacteria. Ti-6Al-4V specimens, each with different surface roughness are produced by mechanical, chemical, and electrolytic polishing. The surface roughness, surface contact angle, surface oxygen content, and surface structure were measured via atomic force microscopy (AFM), laser scanning confocal microscopy (LSCM), drop shape analysis (using sessile drop), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). The micro and macro surface roughness are 10.33–120.05 nm and 0.68–2.34 μm, respectively. The surface X direction and Y direction contact angle are 21.38°–96.44° and 18.37°–92.72°, respectively. The surface oxygen content is 47.36–59.89 at.%. The number of colonies and the optical density (OD) are 7.87 × 106–17.73 × 106 CFU/mL and 0.189–0.245, respectively. The bacterial inhibition were the most effective under the electrolytic polishing of Ti-6Al-4V. The electrolytic polishing of Ti-6Al-4V exhibited the best surface characteristics: the surface roughness of 10 nm, surface contact angle of 92°, and surface oxygen content of 54 at.%, respectively. This provides the best surface treatment of Ti-6Al-4V in dental implants.

scholarly journals Comparative study on the influence of surface characteristics on de-icing evaluation

2021 ◽  
Author(s):  
Halar Memon ◽  
Kiana Mirshahidi ◽  
Kamran Alasvand Zarasvand ◽  
Kevin Golovin ◽  
Davide S. A. De Focatiis ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Comparative Study ◽  
Adhesion Strength ◽  
Partial Correlation ◽  
Contact Angle Hysteresis ◽  
Surface Characteristics ◽  
Evaluation Methods ◽  
Curvilinear Relationship ◽  
Ice Adhesion

AbstractA comparative study of de-icing evaluation methods was conducted in this work, and their variations in response to surface characteristics were investigated. The mechanical de-icing measurements include centrifugal, push, and tensile methods. The centrifugal and the horizontal push (shear) methods suggested a linear relationship of ice adhesion strength with surface roughness, whereas the tensile (normal) method indicated an inverse curvilinear relationship with contact angle hysteresis. A partial correlation of contact angle hysteresis on the shear-based methods was also indicated over a specified range of surface roughness. Further attempts were also made on 1H,1H,2H,2H-perfluorooctyltriethoxysilane-coated surfaces, and the ice adhesion indicated a clear reduction in the normal de-icing method, whereas the shear-based methods did not show a considerable change in ice adhesion, highlighting their mechanical forces-centric response. Lastly, a further evaluation using a hybrid de-icing method was conducted, to verify the influence of surface characteristics on ice removal involving heating, which demonstrated a partial correlation of energy consumption with the ice adhesion strength over a specified range of surface roughness. The results obtained in this study provide crucial information on the influence of surface characteristics on ice adhesion and offer material-dependent correlations of the popular de-icing evaluation methods. The conclusions could be applied to define an appropriate testing method for the evaluation of icephobic surfaces and coatings. Graphical abstract

scholarly journals Aluminium Alloy 8011: Surface Characteristics

2015 ◽  
Vol 719-720 ◽  
pp. 29-37 ◽  
Author(s):  
Maral Rahimi ◽  
Peter Fojan ◽  
Leonid Gurevich ◽  
Alireza Afshari
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Heat Exchanger ◽  
Aluminium Alloy ◽  
Construction Material ◽  
Surface Characteristics ◽  
Cold Surface ◽  
Angle Measurements ◽  
Contact Angle Measurements ◽  
Native Surface

Aluminium alloys are the predominant materials in modern industries. Increased knowledge about the surface characteristics of bare aluminium can enhance the understanding about how to optimize the working conditions for the equipment involving aluminium parts. This work focusses on the properties of native surface of aluminium alloy 8011, which is the main construction material for the production of air-to-air heat exchanger fins. In this study, we address its water wettability, surface roughness and frost formation in different psychometric parameters. The contact angle measurements revealed that this aluminium alloy exhibits a relatively high contact angle of about 78 degree, i.e. is not wetted completely. AFM measurements revealed significant surface roughness of typical heat exchanger fins. The thickness of formed frost was studied in relation to the wettability, humidity and the cold surface temperature.

scholarly journals Actuation and locomotion driven by moisture in paper made with natural pollen

2020 ◽  
Vol 117 (16) ◽  
pp. 8711-8718 ◽  
Author(s):  
Ze Zhao ◽  
Youngkyu Hwang ◽  
Yun Yang ◽  
Tengfei Fan ◽  
Juha Song ◽  
...  
Keyword(s):  
Surface Roughness ◽  
Water Absorption ◽  
Material Properties ◽  
Processing Conditions ◽  
Structure And Properties ◽  
Rapid Exchange ◽  
Wide Range ◽  
Contractile Stress ◽  
Hydrodynamic Effects ◽  
Integrated Responses

Here we describe the development of a humidity-responsive sheet of paper that is derived solely from natural pollen. Adaptive soft material components of the paper exhibit diverse and well-integrated responses to humidity that promote shape reconfiguration, actuation, and locomotion. This mechanically versatile and nonallergenic paper can generate a cyclically high contractile stress upon water absorption and desorption, and the rapid exchange of water drives locomotion due to hydrodynamic effects. Such dynamic behavior can be finely tuned by adjusting the structure and properties of the paper, including thickness, surface roughness, and processing conditions, analogous to those of classical soapmaking. We demonstrate that humidity-responsive paper-like actuators can mimic the blooming of the Michelia flower and perform self-propelled motion. Harnessing the material properties of bioinspired systems such as pollen paper opens the door to a wide range of sustainable, eco-friendly, and biocompatible material innovation platforms for applications in sensing, actuation, and locomotion.

Surface Roughness and Droplet Contact Angle Measurement of Various Orthodontic Bonding Cements

1993 ◽  
Vol 20 (4) ◽  
pp. 297-305 ◽  
Author(s):  
C. O'Kane ◽  
R. G. Oliver ◽  
R. E. Blunden
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Glass Ionomer Cement ◽  
Surface Characteristics ◽  
Contact Angle Measurement ◽  
Angle Measurement ◽  
Bacterial Attachment ◽  
Before And After ◽  
Orthodontic Bonding

Surface characteristics that are considered important for bacterial attachment to thirteen orthodontic bonding composite cements and one glass ionomer cement were examined in vitro before and after toothbrush abrasion. The surface roughness and contact angle measurements were found to be statistically significantly different between the materials, both before and after brushing, and there were also statistically significant changes within materials after brushing. There were low correlation coefficients between surface roughness and contact angle for both pre-and post-brushed materials.

scholarly journals Influence of Additive Firing on the Surface Characteristics, Streptococcus mutans Viability and Optical Properties of Zirconia

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1286
Author(s):  
Wonjoon Moon ◽  
Joo Hyang Park ◽  
Han-Ah Lee ◽  
Bum-Soon Lim ◽  
Shin Hye Chung
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Optical Properties ◽  
Optical Property ◽  
Streptococcus Mutans ◽  
Surface Characteristics ◽  
Repetitive Firing ◽  
Secondary Caries ◽  
Clinically Significant ◽  
Property Changes

The purpose of this study was to observe whether the repetitive firing of dental zirconia caused changes in surface characteristics, S. mutans viability, and optical properties of zirconia. Dental zirconia blocks were sintered and randomly distributed into seven experimental groups: F0–F6. Except for F0, which only went through sintering, the additive firing was performed in order for F1–F6. Surface roughness, contact angle, S. mutans viability by fluorescence, and translucency parameter were measured. They were all highest after sintering (F0) and decreased after additive firings (F1–F6). The additive firing of zirconia after sintering decreased surface roughness, contact angle, S. mutans viability, and translucency. The number of firings after the first firing was not found to be critical in surface characteristics, S. mutans viability, and optical property. Changes in surface characteristics might have led to a decrease in S. mutans viability, while the change of translucency was not clinically significant. This implies that additive firing may prevent secondary caries under zirconia restorations, not compromising esthetic appearance.

Characteristics of TiO2 Nanotube Arrays on Titanium Prepared by Anodization

2011 ◽  
Vol 492 ◽  
pp. 291-295 ◽  
Author(s):  
Dan Li ◽  
Cheng Yun Ning ◽  
Guo Xin Tan ◽  
Hua De Zheng ◽  
Yong Mei Ge
Keyword(s):  
Surface Roughness ◽  
Contact Angle ◽  
Flat Surface ◽  
Titanium Substrate ◽  
Nanotube Arrays ◽  
Oh Groups ◽  
X Ray ◽  
Atomic Force ◽  
Optimal Surface ◽  
The Relationship

Titania nanotube (NT) arrays with a length of 550nm were fabricated on the flat titanium substrate by anodization. The microstructure was identified by scanning electron microscope. The composition has been investigated with X-ray photoelectron microscopy. It also showed that, as compared with the flat surface, the density of Ti-OH groups on the NT surface has been increased. However, according to the contact angle goniometer, the hydrophilicity of the NT surface becomes worse than that of the flat surface. In addition, surface roughness was investigated by non-contact atomic force microscope. It demonstrated that the nano-roughness of NT arrays has been increased. More important is the relationship between contact angle and roughness factor have been analyzed based on the modified Young’s equation. These results indicate that the anodized NT structures may have provided an optimal surface roughness for promoting the bioactivity.

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