Drop impact on super-wettability-contrast annular patterns

2013 ◽  
Vol 730 ◽  
pp. 328-342 ◽  
Author(s):  
Seungho Kim ◽  
Myoung-Woon Moon ◽  
Ho-Young Kim
Keyword(s):  
High Speed ◽  
Solid Surfaces ◽  
Liquid Drops ◽  
Wetting Properties ◽  
Drop Dynamics ◽  
Inner Region ◽  
Water Repellence ◽  
Theoretical Considerations ◽  
Practical Implications ◽  
Liquid Ring

AbstractExtreme wetting properties of solids, either superhydrophobic or superhydrophilic, provide versatile methods to achieve unusual liquid deposit morphologies, such as liquid pearls or polygonal films. Here we report the dynamics of liquid drops that impact on solid surfaces where the extreme wetting properties are coupled in such a way that a superhydrophilic annulus is patterned on a superhydrophobic background. The drop that initially spreads on the inner superhydrophobic region is arrested by the hydrophilic annulus. The liquid deposit gets destabilized because of the strong water repellence of the inner region, exhibiting the burst and disengagement of the liquid film. This process leads to the formation of a liquid ring defined by the annulus pattern, which has practical implications in rapid printing of functional liquids. We visualize such drop dynamics with a high-speed camera and characterize their salient features by combining experimental measurements and theoretical considerations.

Fluids in Motion: Inspiration and Realization for Artists and STEMists

Leonardo ◽  
2015 ◽  
Vol 48 (2) ◽  
pp. 138-146
Author(s):  
Norman J. Zabusky
Keyword(s):  
Visual Art ◽  
High Speed ◽  
Solid Surfaces ◽  
Innovative Technology ◽  
High Speed Photography ◽  
Still Images ◽  
Liquid Drops ◽  
Contemporary Work ◽  
Liquid Pools ◽  
Interactive Displays

The author examines contemporary work in fluids in motion and demonstrates strong connections between visual art and science resulting from innovative technology. In one burgeoning domain—falling liquid drops impacting solid surfaces and liquid pools—it is valuable to compare how artists and scientists describe their goals and their use of high-speed photography to capture and measure events. The author also examines the use of devices to create still images, animations and objects: computers/software for simulation, visualization and 3D printing; installations at focal locations. Finally, he examines the utilization of digital technology by artists, educators, museums and galleries for innovative and interactive displays.

Comparison of the reluctance laminated and solid rotor synchronous machine operating at high temperatures

2019 ◽  
Vol 38 (4) ◽  
pp. 1111-1119 ◽  
Author(s):  
Marcin Lefik ◽  
Krzysztof Komeza ◽  
Ewa Napieralska-Juszczak ◽  
Daniel Roger ◽  
Piotr Andrzej Napieralski
Keyword(s):  
High Speed ◽  
Design Methodology ◽  
Three Dimensional ◽  
Synchronous Machine ◽  
Point Of View ◽  
Heat Sources ◽  
Model Calculations ◽  
Content Type ◽  
Thermal Phenomenon ◽  
Practical Implications

Purpose The purpose of this paper is to present a comparison between reluctance synchronous machine-enabling work at high internal temperature (HT° machine) with laminated and solid rotor. Design/methodology/approach To obtain heat sources for the thermal model, calculations of the electromagnetic field were made using the Opera 3D program including effect of rotation and the resulting eddy current losses. To analyse the thermal phenomenon, the 3D coupled thermal-fluid (CFD) model is used. Findings The presented results show clearly that laminated construction is much better from a point of view of efficiency and temperature. However, solid construction can be interesting for high speed machines due to their mechanical robustness. Research limitations/implications The main problem, despite the use of parallel calculations, is the long calculation time. Practical implications The obtained simulation and experimental results show the possibility of building a machine operating at a much higher ambient temperature than it was previously produced for example in the vicinity of the aircraft turbines. Originality/value The paper presents the application of fully three-dimensional coupled electromagnetic and thermal analysis of new machine constructions designed for elevated temperature.

scholarly journals Capillary transfer of soft films

2020 ◽  
Vol 117 (10) ◽  
pp. 5210-5216 ◽  
Author(s):  
Yue Zhang ◽  
Mengtian Yin ◽  
Yongmin Baek ◽  
Kyusang Lee ◽  
Giovanni Zangari ◽  
...  
Keyword(s):  
High Speed ◽  
Computational Analysis ◽  
Liquid Surface ◽  
Theoretical Models ◽  
Dynamic Contact ◽  
Surface Wetting ◽  
Motion Direction ◽  
Wetting Properties ◽  
Geometric Patterns ◽  
Solid Substrates

Existing transfer technologies in the construction of film-based electronics and devices are deeply established in the framework of native solid substrates. Here, we report a capillary approach that enables a fast, robust, and reliable transfer of soft films from liquid in a defect-free manner. This capillary transfer is underpinned by the transfer front of dynamic contact among receiver substrate, liquid, and film, and can be well controlled by a selectable motion direction of receiver substrates at a high speed. We demonstrate in extensive experiments, together with theoretical models and computational analysis, the robust capabilities of the capillary transfer using a versatile set of soft films with a broad material diversity of both film and liquid, surface-wetting properties, and complex geometric patterns of soft films onto various solid substrates in a deterministic manner.

scholarly journals Movements of Mycoplasma mobile gliding machinery detected by high-speed atomic force microscopy

2021 ◽  
Author(s):  
Kohei Kobayashi ◽  
Noriyuki Kodera ◽  
Taishi Kasai ◽  
Yuhei O Tahara ◽  
Takuma Toyonaga ◽  
...  
Keyword(s):  
Atomic Force Microscopy ◽  
Internal Structure ◽  
Sodium Azide ◽  
High Speed ◽  
Atp Hydrolysis ◽  
Solid Surfaces ◽  
Force Microscopy ◽  
Special Mechanism ◽  
Atomic Force ◽  
Internal Structures

ABSTRACTMycoplasma mobile, a parasitic bacterium, glides on solid surfaces, such as animal cells and glass by a special mechanism. This process is driven by the force generated through ATP hydrolysis on an internal structure. However, the spatial and temporal behaviors of the internal structures in living cells are unclear. In this study, we detected the movements of the internal structure by scanning cells immobilized on a glass substrate using high-speed atomic force microscopy (HS-AFM). By scanning the surface of a cell, we succeeded in visualizing particles, 2 nm in hight and aligned mostly along the cell axis with a pitch of 31.5 nm, consistent with previously reported features based on electron microscopy. Movements of individual particles were then analyzed by HS-AFM. In the presence of sodium azide, the average speed of particle movements was reduced, suggesting that movement is linked to ATP hydrolysis. Partial inhibition of the reaction by sodium azide enabled us to analyze particle behavior in detail, showing that the particles move 9 nm right, relative to the gliding direction, and 2 nm into the cell interior in 330 ms, then return to their original position, based on ATP hydrolysis.IMPORTANCEThe Mycoplasma genus contains bacteria generally parasitic to animals and plants. Some Mycoplasma species form a protrusion at a pole, bind to solid surfaces, and glide by a special mechanism linked to their infection and survival. The special machinery for gliding can be divided into surface and internal structures that have evolved from rotary motors represented by ATP synthases. This study succeeded in visualizing the real-time movements of the internal structure by scanning from the outside of the cell using an innovative high-speed atomic force microscope, and then analyzing their behaviors.

scholarly journals Cultural issues in economics

2012 ◽  
Vol 3 (4) ◽  
pp. 73-91
Author(s):  
Maciej Meyer
Keyword(s):  
Economic Development ◽  
Consumer Behavior ◽  
International Marketing ◽  
Cultural Dimensions ◽  
Cultural Issues ◽  
Best Fitting ◽  
Theoretical Considerations ◽  
Practical Implications

This article has been written with the purpose of attracting attention to the cultural issues, or rather lack of them, in economics. This topic has not been taken frequently into theoretical considerations due to some difficulties, although its practical implications are of great importance. The meaning of institutions which are a part of cultures has been given more coverage in the literature. The following hypothesis is proposed: culture is an important but underestimated component of the economics theory. Although present in consciousness of some classics it should be incorporated to the theory to a bigger degree. The author makes use of the present literature in order to point out the relevant relationships. The problem with the definitions of the word “culture” with respect to economics best-fitting variants is covered. Also, the relation of the problem issue with the science of economics is shown via the presence in thought of the first economists. Moreover, the relation of cultures with institutions is discussed as well as cultural dimensions. The author pays attention to the meaning of cultures in economic development, consumer behavior, international marketing, and business contacts.

scholarly journals Peran Kontrol Diri sebagai Prediktor Perilaku Mengemudi Agresif pada Pengemudi Mobil di Jakarta

MANASA ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 55-64
Author(s):  
Patricia Angeline ◽  
Retha Arjadi
Keyword(s):  
Traffic Accident ◽  
High Speed ◽  
External Factors ◽  
Self Control ◽  
Aggressive Driving ◽  
Driver Behaviour ◽  
Driving Behaviour ◽  
Practical Implications

Many things can cause traffic accident, including the driver behaviour. Aggressive drivingbehaviour is associated with the risk of traffic accident. Aggressive driving behaviour usuallypredicted by external factors, such as other driver’s attitude or gesture that could trigger anger.However, aggressive driving behaviour could also be shown in a situation where there is no otherdriver, for example when someone drive with a high speed in an empty traffic. This means, internalfactor, associated with the ability of the drivers to control themselves, can also contribute toaggressive driving behaviour. This study aims to investigate the role of self-control in predictingaggressive driving behaviour in car driver, specifically in Jakarta. The result from linearaggression analysis shows that self-control significantly predicted aggressive driving behaviourin car drivers in Jakarta. The coefficient is negative, showing that higher self-control determineslower aggressive driving behaviour, and lower self-control determines higher aggressive drivingbehaviour. Practical implications, limitations of the study, and recommendation for future studyare discussed.

scholarly journals Granular impact cratering by liquid drops: Understanding raindrop imprints through an analogy to asteroid strikes

2014 ◽  
Vol 112 (2) ◽  
pp. 342-347 ◽  
Author(s):  
Runchen Zhao ◽  
Qianyun Zhang ◽  
Hendro Tjugito ◽  
Xiang Cheng
Keyword(s):  
High Speed ◽  
Granular Media ◽  
Liquid Drop ◽  
Impact Craters ◽  
High Speed Photography ◽  
Impact Cratering ◽  
Liquid Drops ◽  
Asteroid Impact ◽  
Liquid Marble ◽  
Crater Morphology

When a granular material is impacted by a sphere, its surface deforms like a liquid yet it preserves a circular crater like a solid. Although the mechanism of granular impact cratering by solid spheres is well explored, our knowledge on granular impact cratering by liquid drops is still very limited. Here, by combining high-speed photography with high-precision laser profilometry, we investigate liquid-drop impact dynamics on granular surface and monitor the morphology of resulting impact craters. Surprisingly, we find that despite the enormous energy and length difference, granular impact cratering by liquid drops follows the same energy scaling and reproduces the same crater morphology as that of asteroid impact craters. Inspired by this similarity, we integrate the physical insight from planetary sciences, the liquid marble model from fluid mechanics, and the concept of jamming transition from granular physics into a simple theoretical framework that quantitatively describes all of the main features of liquid-drop imprints in granular media. Our study sheds light on the mechanisms governing raindrop impacts on granular surfaces and reveals a remarkable analogy between familiar phenomena of raining and catastrophic asteroid strikes.

Mitigation of Damage to Solid Surfaces From the Collapse of Cavitation Bubble Clouds

2010 ◽  
Vol 132 (5) ◽  
Author(s):  
Parag V. Chitnis ◽  
Nicholas J. Manzi ◽  
Robin O. Cleveland ◽  
Ronald A. Roy ◽  
R. Glynn Holt
Keyword(s):  
High Speed ◽  
Porous Ceramic ◽  
Bubble Surface ◽  
Back Pressure ◽  
Solid Surfaces ◽  
Surface Erosion ◽  
Cavitation Damage ◽  
Acoustic Transducer ◽  
Bubble Layer ◽  
Bubble Clouds

The collapse of transient bubble clouds near a solid surface was investigated to test a scheme for mitigation of cavitation-induced damage. The target was a porous ceramic disk through which air could be forced. Transient cavitation bubbles were created using a shock-wave lithotripter focused on the surface of the disk. The dynamics of bubble clouds near the ceramic disks were studied for two boundary conditions: no back pressure resulting in surface free of bubbles and 10 psi (0.7 atm) of back pressure, resulting in a surface with a sparse (30% of area) bubble layer. Images of the cavitation near the surface were obtained from a high-speed camera. Additionally, a passive cavitation detector (3.5 MHz focused acoustic transducer) was aligned with the surface. Both the images and the acoustic measurements indicated that bubble clouds near a ceramic face without a bubble layer collapsed onto the boundary, subsequently leading to surface erosion. When a sparse bubble layer was introduced, bubble clouds collapsed away from the surface, thus mitigating cavitation damage. The erosion damage to the ceramic disks after 300 shock waves was quantified using micro-CT imaging. Pitting up to 1 mm deep was measured for the bubble-free surface, and the damage to the bubble surface was too small to be detected.

Effect of a High Electric Field on the Thermal and Phase Change Characteristics of an Impacting Drop

2019 ◽  
Author(s):  
Abhishek Basavanna ◽  
Prajakta Khapekar ◽  
Navdeep Singh Dhillon
Keyword(s):  
Heat Transfer ◽  
Electric Field ◽  
Phase Change ◽  
Electric Fields ◽  
High Speed ◽  
Impact Behavior ◽  
Liquid Drops ◽  
Active Interest ◽  
Post Impact ◽  
High Electric Fields

Abstract The effect of applied electric fields on the behavior of liquids and their interaction with solid surfaces has been a topic of active interest for many decades. This has important implications in phase change heat transfer processes such as evaporation, boiling, and condensation. Although the effect of low to moderate voltages has been studied, there is a need to explore the interaction of high electric fields with liquid drops and bubbles, and their effect on heat transfer and phase change. In this study, we employ a high speed optical camera to study the dynamics of a liquid drop impacting a hot substrate under the application of high electric fields. Experimental results indicate a significant change in the pre- and post-impact behavior of the drop. Prior to impact, the applied electric field elongates the drop in the direction of the electric field. Post-impact, the recoil phase of the drop is significantly affected by charging effects. Further, a significant amount of micro-droplet ejection is observed with an increase in the applied voltage.

A Technique for the Detection of Liquid Slip at a Load-Bearing, High Shear Contact

2005 ◽  
Author(s):  
J. H. Choo ◽  
H. A. Spikes ◽  
M. Ratoi ◽  
R. P. Glovnea ◽  
A. Forrest
Keyword(s):  
High Speed ◽  
Physical Phenomenon ◽  
Solid Surfaces ◽  
The Other ◽  
Plasma Cleaning ◽  
High Shear ◽  
Test Rig ◽  
Simple Liquids ◽  
New Type ◽  
O2 Plasma

This research aims to exploit the physical phenomenon of simple liquids slipping against very smooth solid surfaces, to create a new type of bearing where the lubricant slips against one surface but not the other. To demonstrate the feasibility of this idea, a special test rig capable of measuring milli-Newton forces has been employed to measure friction in high-speed, sliding contacts between a steel roller and sapphire window, lubricated by hexadecane. Sapphire was made either lyophobic by coating with a self-assembled silane monolayer, or lyophilic by O2-plasma cleaning. The roller was made lyophilic. A significant reduction in friction was achieved with lyophobic sapphire but not with lyophilic sapphire. This reduced friction is believed to result from lubricant slip against the lyophobic surface. One possible application of such a bearing will be in microsystems and devices.

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