Hydrothermal waves on ethanol droplets evaporating under terrestrial and reduced gravity levels

2012 ◽  
Vol 712 ◽  
pp. 614-623 ◽  
Author(s):  
F. Carle ◽  
B. Sobac ◽  
D. Brutin
Keyword(s):  
Experimental Study ◽  
Normal Gravity ◽  
Scaling Law ◽  
Gravity Level ◽  
Reduced Gravity ◽  
Microgravity Conditions ◽  
Evaporation Dynamics ◽  
Good Agreement

AbstractThis experimental study, performed under microgravity conditions, focuses on the evaporation dynamics of ethanol drops and the formation and behaviour of the hydrothermal waves that spontaneously develop on the drop surfaces. The aim of this study is to compare our results to a similar study performed under normal gravity conditions to confirm the purely thermocapillary origin of these instabilities. A scaling law predicts with good agreement the number of instabilities that form, regardless of the gravity level.

scholarly journals Use of fractal models to define the scaling behavior of the aquifers’ parameters at the mesoscale

2020 ◽  
Author(s):  
C. Fallico ◽  
S. De Bartolo ◽  
G. F. A. Brunetti ◽  
G. Severino
Keyword(s):  
Experimental Study ◽  
Scaling Law ◽  
Fractal Model ◽  
The Other ◽  
Grain Size Analysis ◽  
Size Analysis ◽  
Slug Tests ◽  
Fractal Models ◽  
Meso Scale ◽  
Good Agreement

Abstract We present an experimental study aiming at the identification of the hydraulic conductivity in an aquifer which was packed according to four different configurations. The conductivity was estimated by means of slug tests, whereas the other parameters were determined by the grain size analysis. Prior to the fractal we considered the dependence of the conductivity upon the porosity through a power (scaling) law which was found in a very good agreement within the range from the laboratory to the meso-scale. The dependence of the conductivity through the porosity was investigated by identifying the proper fractal model. Results obtained provide valuable indications about the behavior, among the others, of the tortuosity, a parameter playing a crucial role in the dispersion phenomena taking place in the aquifers.

scholarly journals Nucleation barriers at corners for a cubic-to-tetragonal phase transformation

2015 ◽  
Vol 145 (4) ◽  
pp. 715-724 ◽  
Author(s):  
Peter Bella ◽  
Michael Goldman
Keyword(s):  
Phase Transformation ◽  
Tetragonal Phase ◽  
Scaling Law ◽  
Energetic Cost ◽  
Minimal Energy ◽  
Physical Experiments ◽  
Domain With A Corner ◽  
Appl Math ◽  
Good Agreement

We are interested in the energetic cost of a martensitic inclusion of volume V in austenite for the cubic-to-tetragonal phase transformation. In contrast with the work of Knüpfer, Kohn and Otto (Commun. Pure Appl. Math.66 (2013), 867–904), we consider a domain with a corner and obtain a better scaling law for the minimal energy (Emin ∼ min(V2/3, V7/9)). Our predictions are in good agreement with physical experiments where nucleation of martensite is usually observed near the corners of the specimen.

Effects of gravity on processing heavy metal fluoride fibers

1997 ◽  
Vol 12 (9) ◽  
pp. 2223-2225 ◽  
Author(s):  
Dennis S. Tucker ◽  
Gary L. Workman ◽  
Guy A. Smith
Keyword(s):  
Heavy Metal ◽  
Crystallization Temperature ◽  
Normal Gravity ◽  
Crystal Nucleation ◽  
Sounding Rocket ◽  
Metal Fluoride ◽  
Reduced Gravity ◽  
Rocket Flight ◽  
Heavy Metal Fluoride

The effects of gravity on the crystal nucleation of heavy metal fluoride fibers have been studied in preliminary experiments utilizing NASA's KC-135 reduced gravity aircraft and a microgravity sounding rocket flight. Commercially produced fibers were heated to the crystallization temperature in normal and reduced gravity. The fibers processed in normal gravity showed complete crystallization while the fibers processed in reduced gravity did not show signs of crystallization.

Experimental Study on the Scaling Law of a Self-Modulated Laser Wakefield Accelerator

2006 ◽  
Author(s):  
Kazuyoshi Koyama ◽  
Shin-ichi Masuda ◽  
Susumu Kato ◽  
Eisuke Miura ◽  
Mitsumori Tanimoto
Keyword(s):  
Experimental Study ◽  
Scaling Law ◽  
Laser Wakefield ◽  
Wakefield Accelerator ◽  
Laser Wakefield Accelerator

Experimental Study on the Shear Properties of Concrete Column Repaired by CFRP

2012 ◽  
Vol 166-169 ◽  
pp. 1598-1602
Author(s):  
Xi Guang Cui ◽  
Zhi Wei Wang ◽  
Nan Ma ◽  
Zhong Long Yu
Keyword(s):  
Experimental Study ◽  
Concrete Columns ◽  
Concrete Column ◽  
Longitudinal Reinforcement ◽  
Simulation Data ◽  
Carbon Fiber Reinforced Plastics ◽  
Reinforced Plastics ◽  
Fiber Reinforced Plastics ◽  
Main Factors ◽  
Good Agreement

In this paper, shear study was carried out on four reinforced concrete columns in which two columns were reinforced by CFRP (carbon fiber reinforced plastics). The three main factors: shear span ratio, ratio of longitudinal reinforcement, CFRP paste quantity (layer numbers) were analysied since they affect the reinforced effect of CFRP. Through the experiment and simulation, the results indicate that the shear strength of CFRP strengthened concrete columns is obvious, which shows good agreement with experimental and simulation data.

scholarly journals Mechanics of spontaneously formed nanoblisters trapped by transferred 2D crystals

2018 ◽  
Vol 115 (31) ◽  
pp. 7884-7889 ◽  
Author(s):  
Daniel A. Sanchez ◽  
Zhaohe Dai ◽  
Peng Wang ◽  
Arturo Cantu-Chavez ◽  
Christopher J. Brennan ◽  
...  
Keyword(s):  
Scaling Law ◽  
New Physics ◽  
Adhesion Energy ◽  
Work Of Adhesion ◽  
Fourth Power ◽  
Layered Systems ◽  
Simple Scaling ◽  
Dynamics Simulations ◽  
2D Crystals ◽  
Good Agreement

Layered systems of 2D crystals and heterostructures are widely explored for new physics and devices. In many cases, monolayer or few-layer 2D crystals are transferred to a target substrate including other 2D crystals, and nanometer-scale blisters form spontaneously between the 2D crystal and its substrate. Such nanoblisters are often recognized as an indicator of good adhesion, but there is no consensus on the contents inside the blisters. While gas-filled blisters have been modeled and measured by bulge tests, applying such models to spontaneously formed nanoblisters yielded unrealistically low adhesion energy values between the 2D crystal and its substrate. Typically, gas-filled blisters are fully deflated within hours or days. In contrast, we found that the height of the spontaneously formed nanoblisters dropped only by 20–30% after 3 mo, indicating that probably liquid instead of gas is trapped in them. We therefore developed a simple scaling law and a rigorous theoretical model for liquid-filled nanoblisters, which predicts that the interfacial work of adhesion is related to the fourth power of the aspect ratio of the nanoblister and depends on the surface tension of the liquid. Our model was verified by molecular dynamics simulations, and the adhesion energy values obtained for the measured nanoblisters are in good agreement with those reported in the literature. This model can be applied to estimate the pressure inside the nanoblisters and the work of adhesion for a variety of 2D interfaces, which provides important implications for the fabrication and deformability of 2D heterostructures and devices.

scholarly journals Coupled Dynamics of Cable-Harnessed Structures: Experimental Validation

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Karthik Yerrapragada ◽  
Armaghan Salehian
Keyword(s):  
Experimental Study ◽  
Partial Differential Equations ◽  
Frequency Response ◽  
Experimental Validation ◽  
Response Functions ◽  
Beam Structure ◽  
Coupled Dynamics ◽  
Coupled Partial Differential Equations ◽  
Offset Distance ◽  
Good Agreement

The experimental study and model validations for the coupled dynamics of a cable-harnessed beam structure are presented. The system under consideration consists of multiple pretensioned cables attached along the length of the host beam structure positioned at an offset distance from the beam centerline. Analytical model presented by the coupled partial differential equations (PDEs) for various coordinates of vibrations is found, and the displacement frequency response functions (FRFs) obtained for both Euler–Bernoulli and Timoshenko-based models are compared to those from the experiments for validation. The results are shown to be in very good agreement with the experiments.

Reduced-Gravity Human Factors Research with Aircraft

1969 ◽  
Vol 11 (5) ◽  
pp. 463-471 ◽  
Author(s):  
Michael J. Moran
Keyword(s):  
Human Factors ◽  
Space Flight ◽  
Gravity Data ◽  
Parabolic Flight ◽  
Gravity Level ◽  
Reduced Gravity ◽  
Low Gravity ◽  
Simulation Techniques ◽  
Space Experiments ◽  
Actual Space

Human factors in a low-gravity environment became important with the beginning of manned space flight programs. The costs and dangers associated with actual space experiments necessitated the development of reduced-gravity simulation techniques. Since parabolic flight is the only way to produce approximately the same physical conditions as orbital space flight, it is the only technique acceptable for many human factors studies. However, the shortness of periods at the desired gravity level and the high gravity levels of the pre- and post-parabola flight compromise the effectiveness of the technique. In spite of its faults, this technique has been used to produce many meaningful studies. These studies have done much to increase our limited knowledge of reduced-gravity human factors. It appears that this technique will continue to be a main source of low-gravity data, until the era of manned orbiting laboratories.

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