scholarly journals Ethanol as a Probe for the Mechanism of Bubble Nucleation in the Diet Coke and Mentos Experiment

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1691
Author(s):  
Thomas S. Kuntzleman ◽  
Jacob T. Kuntzleman
Keyword(s):  
Surface Tension ◽  
Science Teachers ◽  
Bubble Nucleation ◽  
Simple Experiment ◽  
Carbonated Beverages ◽  
Physicochemical Processes ◽  
Nucleation Sites ◽  
Ethanol Addition ◽  
The Impact ◽  
Theory And Experiment

The Diet Coke and Mentos experiment involves dropping Mentos candies into carbonated beverages to produce a fountain. This simple experiment has enjoyed popularity with science teachers and the general public. Studies of the physicochemical processes involved in the generation of the fountain have been largely informed by the physics of bubble nucleation. Herein, we probe the effect of ethanol addition on the Diet Coke and Mentos experiment to explore the impact that beverage surface tension and viscosity have on the heights of fountains achieved. Our results indicate that current descriptions of the effects of surface tension and viscosity are not completely understood. We also extend and apply a previously reported, simplified version of Brunauer–Emmett–Teller theory to investigate kinetic and mechanistic aspects of bubble nucleation on the surface of Mentos candies in carbonated beverages. A combination of this new theory and experiment allows for the estimation that the nucleation sites on the Mentos candy that catalyze degassing are 1–3 mm in size, and that between 50,000 and 300,000 of these sites actively nucleate bubbles on a single Mentos candy. While the methods employed are not highly sophisticated, they have potential to stimulate fresh investigations and insights into bubble nucleation in carbonated beverages.

scholarly journals Deciphering The Molecular Mechanism Of Water Boiling At Heterogeneous Interfaces

2021 ◽  
Author(s):  
Konstantinos Karalis ◽  
Dirk Zahn ◽  
Nikolaos Prasianakis ◽  
Bojan Niceno ◽  
Sergey V. Churakov
Keyword(s):  
Molecular Mechanism ◽  
Heat Removal ◽  
Nucleate Boiling ◽  
Surface Hydrophobicity ◽  
Bubble Nucleation ◽  
Geothermal Systems ◽  
Transition Path ◽  
Nucleation Sites ◽  
Dynamics Simulations ◽  
The Impact

Abstract Water boiling control evolution of natural geothermal systems is widely exploited in industrial processes due to the unique non-linear thermophysical behavior. Even though the properties of water both in the liquid and gas state have been extensively studied experimentally and by numerical simulations, there is still a fundamental knowledge gap in understanding the mechanism of the heterogeneous nucleate boiling controlling evaporation and condensation. In this study, the molecular mechanism of bubble nucleation at the hydrophilic and hydrophobic solid-water interface was determined by performing unbiased molecular dynamics simulations using the transition path sampling scheme. Analyzing the liquid to vapor transition path, the initiation of small void cavities (vapor bubbles nuclei) and their subsequent merging mechanism, leading to successively growing vacuum domains (vapor phase), has been elucidated. The molecular mechanism and the boiling nucleation sites' location are strongly dependent on the solid surface hydrophobicity and hydrophilicity. Then simulations reveal the impact of the surface functionality on the adsorbed thin water molecules film structuring and the location of high probability nucleation sites. Our findings provide molecular-scale insights into the computational aided design of new novel materials for more efficient heat removal and rationalizing the damage mechanisms.

scholarly journals Deciphering the molecular mechanism of water boiling at heterogeneous interfaces

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Konstantinos Karalis ◽  
Dirk Zahn ◽  
Nikolaos I. Prasianakis ◽  
Bojan Niceno ◽  
Sergey V. Churakov
Keyword(s):  
Molecular Mechanism ◽  
Heat Removal ◽  
Nucleate Boiling ◽  
Surface Hydrophobicity ◽  
Bubble Nucleation ◽  
Geothermal Systems ◽  
Transition Path ◽  
Nucleation Sites ◽  
Dynamics Simulations ◽  
The Impact

AbstractWater boiling control evolution of natural geothermal systems is widely exploited in industrial processes due to the unique non-linear thermophysical behavior. Even though the properties of water both in the liquid and gas state have been extensively studied experimentally and by numerical simulations, there is still a fundamental knowledge gap in understanding the mechanism of the heterogeneous nucleate boiling controlling evaporation and condensation. In this study, the molecular mechanism of bubble nucleation at the hydrophilic and hydrophobic solid–water interface was determined by performing unbiased molecular dynamics simulations using the transition path sampling scheme. Analyzing the liquid to vapor transition path, the initiation of small void cavities (vapor bubbles nuclei) and their subsequent merging mechanism, leading to successively growing vacuum domains (vapor phase), has been elucidated. The molecular mechanism and the boiling nucleation sites’ location are strongly dependent on the solid surface hydrophobicity and hydrophilicity. Then simulations reveal the impact of the surface functionality on the adsorbed thin water molecules film structuring and the location of high probability nucleation sites. Our findings provide molecular-scale insights into the computational aided design of new novel materials for more efficient heat removal and rationalizing the damage mechanisms.

scholarly journals Buoyancy control in ammonoid cephalopods refined by complex internal shell architecture

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
David J. Peterman ◽  
Kathleen A. Ritterbush ◽  
Charles N. Ciampaglio ◽  
Erynn H. Johnson ◽  
Shinya Inoue ◽  
...  
Keyword(s):  
Surface Tension ◽  
Water Retention Capacity ◽  
Functional Explanation ◽  
Retention Capacity ◽  
Biomechanical Stress ◽  
Liquid Retention ◽  
3D Printed ◽  
Functional Explanations ◽  
Hydrophilic Coatings ◽  
The Impact

AbstractThe internal architecture of chambered ammonoid conchs profoundly increased in complexity through geologic time, but the adaptive value of these structures is disputed. Specifically, these cephalopods developed fractal-like folds along the edges of their internal divider walls (septa). Traditionally, functional explanations for septal complexity have largely focused on biomechanical stress resistance. However, the impact of these structures on buoyancy manipulation deserves fresh scrutiny. We propose increased septal complexity conveyed comparable shifts in fluid retention capacity within each chamber. We test this interpretation by measuring the liquid retained by septa, and within entire chambers, in several 3D-printed cephalopod shell archetypes, treated with (and without) biomimetic hydrophilic coatings. Results show that surface tension regulates water retention capacity in the chambers, which positively scales with septal complexity and membrane capillarity, and negatively scales with size. A greater capacity for liquid retention in ammonoids may have improved buoyancy regulation, or compensated for mass changes during life. Increased liquid retention in our experiments demonstrate an increase in areas of greater surface tension potential, supporting improved chamber refilling. These findings support interpretations that ammonoids with complex sutures may have had more active buoyancy regulation compared to other groups of ectocochleate cephalopods. Overall, the relationship between septal complexity and liquid retention capacity through surface tension presents a robust yet simple functional explanation for the mechanisms driving this global biotic pattern.

scholarly journals Phase transitions from the fifth dimension

2021 ◽  
Vol 2021 (2) ◽  
Author(s):  
Kaustubh Agashe ◽  
Peizhi Du ◽  
Majid Ekhterachian ◽  
Soubhik Kumar ◽  
Raman Sundrum
Keyword(s):  
Bubble Dynamics ◽  
Effective Field ◽  
Bubble Nucleation ◽  
Thin Wall ◽  
Black Brane ◽  
Composite Higgs ◽  
Fifth Dimension ◽  
Two Phases ◽  
Holographic Description ◽  
The Impact

Abstract We study the cosmological transition of 5D warped compactifications, from the high-temperature black-brane phase to the low-temperature Randall-Sundrum I phase. The transition proceeds via percolation of bubbles of IR-brane nucleating from the black-brane horizon. The violent bubble dynamics can be a powerful source of observable stochastic gravitational waves. While bubble nucleation is non-perturbative in 5D gravity, it is amenable to semiclassical treatment in terms of a “bounce” configuration interpolating between the two phases. We demonstrate how such a bounce configuration can be smooth enough to maintain 5D effective field theory control, and how a simple ansatz for it places a rigorous lower-bound on the transition rate in the thin-wall regime, and gives plausible estimates more generally. When applied to the Hierarchy Problem, the minimal Goldberger-Wise stabilization of the warped throat leads to a slow transition with significant supercooling. We demonstrate that a simple generalization of the Goldberger-Wise potential modifies the IR-brane dynamics so that the transition completes more promptly. Supercooling determines the dilution of any (dark) matter abundances generated before the transition, potentially at odds with data, while the prompter transition resolves such tensions. We discuss the impact of the different possibilities on the strength of the gravitational wave signals. Via AdS/CFT duality the warped transition gives a theoretically tractable holographic description of the 4D Composite Higgs (de)confinement transition. Our generalization of the Goldberger-Wise mechanism is dual to, and concretely models, our earlier proposal in which the composite dynamics is governed by separate UV and IR RG fixed points. The smooth 5D bounce configuration we introduce complements the 4D dilaton/radion dominance derivation presented in our earlier work.

Electrohydrodynamic stability: Taylor–Melcher theory for a liquid bridge suspended in a dielectric gas

2002 ◽  
Vol 452 ◽  
pp. 163-187 ◽  
Author(s):  
C. L. BURCHAM ◽  
D. A. SAVILLE
Keyword(s):  
Surface Tension ◽  
Dielectric Constant ◽  
Electric Fields ◽  
Liquid Bridge ◽  
Numerical Solutions ◽  
Specific Conductivity ◽  
Axisymmetric Deformation ◽  
Aspect Ratios ◽  
The Stability ◽  
Theory And Experiment

A liquid bridge is a column of liquid, pinned at each end. Here we analyse the stability of a bridge pinned between planar electrodes held at different potentials and surrounded by a non-conducting, dielectric gas. In the absence of electric fields, surface tension destabilizes bridges with aspect ratios (length/diameter) greater than π. Here we describe how electrical forces counteract surface tension, using a linearized model. When the liquid is treated as an Ohmic conductor, the specific conductivity level is irrelevant and only the dielectric properties of the bridge and the surrounding gas are involved. Fourier series and a biharmonic, biorthogonal set of Papkovich–Fadle functions are used to formulate an eigenvalue problem. Numerical solutions disclose that the most unstable axisymmetric deformation is antisymmetric with respect to the bridge’s midplane. It is shown that whilst a bridge whose length exceeds its circumference may be unstable, a sufficiently strong axial field provides stability if the dielectric constant of the bridge exceeds that of the surrounding fluid. Conversely, a field destabilizes a bridge whose dielectric constant is lower than that of its surroundings, even when its aspect ratio is less than π. Bridge behaviour is sensitive to the presence of conduction along the surface and much higher fields are required for stability when surface transport is present. The theoretical results are compared with experimental work (Burcham & Saville 2000) that demonstrated how a field stabilizes an otherwise unstable configuration. According to the experiments, the bridge undergoes two asymmetric transitions (cylinder-to-amphora and pinch-off) as the field is reduced. Agreement between theory and experiment for the field strength at the pinch-off transition is excellent, but less so for the change from cylinder to amphora. Using surface conductivity as an adjustable parameter brings theory and experiment into agreement.

scholarly journals Euler–Lagrange Modeling of Bubbles Formation in Supersaturated Water

2018 ◽  
Vol 2 (3) ◽  
pp. 39 ◽  
Author(s):  
Alessandro Battistella ◽  
Sander Aelen ◽  
Ivo Roghair ◽  
Martin van Sint Annaland
Keyword(s):  
Phase Transition ◽  
Numerical Models ◽  
Bubble Formation ◽  
Industrial Applications ◽  
Bubble Nucleation ◽  
Initial Growth ◽  
Depletion Effect ◽  
Nucleation Sites ◽  
Scale Modelling ◽  
Spherical Bubbles

Phase transition, and more specifically bubble formation, plays an important role in many industrial applications, where bubbles are formed as a consequence of reaction such as in electrolytic processes or fermentation. Predictive tools, such as numerical models, are thus required to study, design or optimize these processes. This paper aims at providing a meso-scale modelling description of gas–liquid bubbly flows including heterogeneous bubble nucleation using a Discrete Bubble Model (DBM), which tracks each bubble individually and which has been extended to include phase transition. The model is able to initialize gas pockets (as spherical bubbles) representing randomly generated conical nucleation sites, which can host, grow and detach a bubble. To demonstrate its capabilities, the model was used to study the formation of bubbles on a surface as a result of supersaturation. A higher supersaturation results in a faster rate of nucleation, which means more bubbles in the column. A clear depletion effect could be observed during the initial growth of the bubbles, due to insufficient mixing.

scholarly journals The Impact of Teaching Physics via Modeling on Modifying Alternative Conception of Energy and Momentum Conservation among 11th Grade Female Students

2017 ◽  
Vol 11 (1) ◽  
pp. 53
Author(s):  
Abdulah K. Ambusaidi ◽  
Rahma M. Al Sabri
Keyword(s):  
Science Teachers ◽  
Momentum Conservation ◽  
Female Students ◽  
Scientific Models ◽  
Significant Difference ◽  
Energy And Momentum ◽  
The Impact ◽  
Teaching Physics ◽  
Experimental Group ◽  
11Th Grade

This study investigated the impact of teaching physics via modeling on theacquisition of energy and momentum conservation concepts. The sample consisted of 91 female students selected from 11th grade female students in two schools in Al-Dakhiliyah Governorate in Oman. The experimental group (n = 45) was taught via the modeling method, and the control group (n = 46) was taught using a traditional method. The study lasted six weeks during the second semester of the academic year 2013/2014. A teacher guide for teaching by models was designed and validated by a group of experts. To measure the acquisition of physics concepts, energy and momentum, an achievement test was used. The test consisted of 20 multiple-choice questions. Its reliability was measured by test-retest method (r = 0.79). The results revealed a statistically significant difference (p < .05) between the means of the experimental and control groups in favor of the experimental group. The study recommends that science teachers ought to use models and modeling in their teaching. Workshops to train supervisors, in-service teachers and pre-service teachers in the construction and development of scientific models need to be conducted

scholarly journals Use of Massive Open Online Courses (MOOCs)  In the professional development of science teachers Jeddah

2019 ◽  
Vol 3 (10) ◽  
Author(s):  
Mounira Mohammed Al-Raghbi
Keyword(s):  
Professional Development ◽  
Standard Deviation ◽  
Science Teachers ◽  
Achievement Test ◽  
Impact Measurement ◽  
Continuous Training ◽  
Satisfaction Questionnaire ◽  
Distance Training ◽  
Strongly Agree ◽  
The Impact

    The current research aimed to identify the effectiveness of MOOCs as an electronic training platform for the professional development of science teachers in Jeddah. The researcher used the semi-experimental approach in a one-group design. The experiment was applied to the basic sample of research (30) Education East Jeddah Girls, who received the active learning course through direct training, were randomly selected unintentionally. The researcher used two tools to collect information and data related to the study: N of (20) paragraph tribal dish and Uday, in addition to a questionnaire to measure the sample satisfaction MOOCs as a platform for distance training, consisting of (48) paragraph. The data of this study were analyzed using the statistical packages of social programs (SPSS) according to the following statistical methods: arithmetical mean, standard deviation and t value for the pre-test and final test scores by t-test for two independent sample samples, Eta coefficient of impact measurement, Cronbach's Alpha coefficient for measurement of test stability, consistency of satisfaction criterion, and arithmetic averages and standard deviations of responses of study group members in the satisfaction questionnaire. The study reached several results, the most important of which are: -MOOCs achieved an efficiency level in the results of the achievement test with an average of (5.17) score for pre-test compared to (19.63) in the post-test. -The size of the calculated effect reached (0.99). This means that the size of the impact is great for the use of open source electronic courses (MOOCs) in the professional development of science teachers in Jeddah. -There is satisfaction with science teachers on the use of MOOCs in their professional development, where the mean is 4.37, indicating that there is satisfaction (strongly agree) on the questionnaire of satisfaction with the use of MOOCs as a distance training platform for the professional development of them -The standard deviation of the general arithmetic mean (0.119), which is a value and a sign of the great homogeneity between the responses of the members of the research sample (science parameters) on the expressions of satisfaction questionnaire In light of the results, the researcher presented a set of recommendations, the most important of which are: - To promote the culture of e-learning using electronic educational platforms MOOCs. - Provide open and continuous training programs for in-service teachers for their effectiveness and development. - Offering more training courses for electronic platforms carrying the specifications of MOOCs - Taking advantage of the current study tools, namely (the achievement test- the measure of satisfaction) to assess the   impact of professional development For science teachers in Jeddah.      

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