scholarly journals Radial dynamics of an encapsulated microbubble with interface energy

2021 ◽  
Vol 932 ◽  
Author(s):  
Nehal Dash ◽  
Ganesh Tamadapu
Keyword(s):  
Dominant Role ◽  
Interface Energy ◽  
Bending Rigidity ◽  
Residual Stress Field ◽  
Interface Area ◽  
Interface Tension ◽  
Coupled Effect ◽  
Curvature Term ◽  
Interface Parameters ◽  
Area Strain

In this work a mathematical model based on interface energy is proposed within the framework of surface continuum mechanics to study the dynamics of encapsulated bubbles. The interface model naturally induces a residual stress field into the bulk of the bubble, with possible expansion or shrinkage from a stress-free configuration to a natural equilibrium configuration. The significant influence of interface area strain and the coupled effect of stretch and curvature is observed in the numerical simulations based on constrained optimization. Due to the bending rigidity related to additional terms, the dynamic interface tension can become negative, but not due to the interface area strain. The coupled effect of interface strain and curvature term observed is new and plays a dominant role in the dominant compression behaviour of encapsulated bubbles observed in the experiments. The present model is validated by fitting the experimental data of $1.7\,\mathrm {\mu }$ m, $1.4\,\mathrm {\mu }$ m and $1\,\mathrm {\mu }$ m radii bubbles by calculating the optimized parameters. This work also highlights the role of interface parameters and natural configuration gas pressure in estimating the size-independent viscoelastic material properties of encapsulated bubbles with interesting future developments.

scholarly journals Experimental and Computational Modeling of Microemulsion Phase Behavior

2021 ◽  
Author(s):  
Vai Yee Hon ◽  
Ismail B.M. Saaid
Keyword(s):  
Phase Behavior ◽  
Oil Recovery ◽  
Computational Simulation ◽  
Theoretical Models ◽  
Interface Energy ◽  
Structure Property ◽  
Bending Rigidity ◽  
Qspr Model ◽  
Wide Range ◽  
Surfactant Solubilization

The phase behavior of microemulsions formed in a surfactant-brine-oil system for a chemical Enhanced Oil Recovery (EOR) application is complex and depends on a range of parameters. Phase behavior indicates a surfactant solubilization. Phase behavior tests are simple but time-consuming especially when it involves a wide range of surfactant choices at various concentrations. An efficient and insightful microemulsion formulation via computational simulation can complement phase behavior laboratory test. Computational simulation can predict various surfactant properties, including microemulsion phase behavior. Microemulsion phase behavior can be predicted predominantly using Quantitative Structure-Property Relationship (QSPR) model. QSPR models are empirical and limited to simple pure oil system. Its application domain is limited due to the model cannot be extrapolated beyond reference condition. Meanwhile, there are theoretical models based on physical chemistry of microemulsion that can predict microemulsion phase behavior. These models use microemulsion surface tension and torque concepts as well as with solution of bending rigidity of microemulsion interface with relation to surface solubilization and interface energy.

Growth of hematite on (0001) and {1102} sapphire substrates

1990 ◽  
Vol 48 (4) ◽  
pp. 376-377
Author(s):  
Lisa A. Tietz ◽  
Scott R. Summerfelt ◽  
C. Barry Carter
Keyword(s):  
Imaging Techniques ◽  
Chemical Vapor ◽  
Interface Energy ◽  
Dark Field ◽  
Cation Sublattice ◽  
Sapphire Substrates ◽  
Dark Field Imaging ◽  
Weak Beam ◽  
Pressure Chemical ◽  
Interface Structures

Defects in thin films are often introduced at the substrate-film interface during the early stages of growth. The interface structures of semiconductor heterojunctions have been extensively studied because of the electrical activity of defects in these materials. Much less attention has been paid to the structure of oxide-oxide heterojunctions. In this study, the structures of the interfaces formed between hematite (α-Fe2O3) and two orientations of sapphire (α-Al2O3) are examined in relationship to the defects introduced into the hematite film. In such heterojunctions, the oxygen sublattice is expected to have a strong influence on the epitaxy; however, defects which involve only the cation sublattice may be introduced at the interface with little increase in interface energy.Oxide heterojunctions were produced by depositing small quantities of hematite directly onto electrontransparent sapphire substrates using low-pressure chemical vapor deposition. Prior to deposition, the ionthinned substrates were chemically cleaned and annealed at 1400°C to give “clean”, crystalline surfaces. Hematite was formed by the reaction of FeCl3 vapor with water vapor at 1150°C and 1-2 Torr. The growth of the hematite and the interface structures formed on (0001) and {102} substrates have been studied by bright-field, strong- and weak-beam dark-field imaging techniques.

Formation of high temperature phase in flash-evaporated SnSe films

1990 ◽  
Vol 48 (4) ◽  
pp. 698-699
Author(s):  
J.P.S. Hanjra
Keyword(s):  
Thin Films ◽  
Electrical Properties ◽  
Energy Gap ◽  
Dominant Role ◽  
Fine Powder ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
Water Mixture ◽  
Flash Evaporation ◽  
Photovoltaic Applications

Tin mono selenide (SnSe) with an energy gap of about 1 eV is a potential material for photovoltaic applications. Various authors have studied the structure, electronic and photoelectronic properties of thin films of SnSe grown by various deposition techniques. However, for practical photovoltaic junctions the electrical properties of SnSe films need improvement. We have carried out investigations into the properties of flash evaporated SnSe films. In this paper we report our results on the structure, which plays a dominant role on the electrical properties of thin films by TEM, SEM, and electron diffraction (ED).Thin films of SnSe were deposited by flash evaporation of SnSe fine powder prepared from high purity Sn and Se, onto glass, mica and KCl substrates in a vacuum of 2Ø micro Torr. A 15% HF + 2Ø% HNO3 solution was used to detach SnSe film from the glass and mica substrates whereas the film deposited on KCl substrate was floated over an ethanol water mixture by dissolution of KCl. The floating films were picked up on the grids for their EM analysis.

Chronic Pain: Fundamental Scientific Considerations, Specifically for Legal Claims

2013 ◽  
Vol 18 (1) ◽  
pp. 1-18 ◽  
Author(s):  
Robert J. Barth
Keyword(s):  
Health Outcomes ◽  
Pain Perception ◽  
Driving Forces ◽  
Psychological Treatment ◽  
Dominant Role ◽  
Meta Analysis ◽  
General Medicine ◽  
Pain Syndrome ◽  
Problematic Relationship

Abstract Scientific findings have indicated that psychological and social factors are the driving forces behind most chronic benign pain presentations, especially in a claim context, and are relevant to at least three of the AMA Guides publications: AMA Guides to Evaluation of Disease and Injury Causation, AMA Guides to Work Ability and Return to Work, and AMA Guides to the Evaluation of Permanent Impairment. The author reviews and summarizes studies that have identified the dominant role of financial, psychological, and other non–general medicine factors in patients who report low back pain. For example, one meta-analysis found that compensation results in an increase in pain perception and a reduction in the ability to benefit from medical and psychological treatment. Other studies have found a correlation between the level of compensation and health outcomes (greater compensation is associated with worse outcomes), and legal systems that discourage compensation for pain produce better health outcomes. One study found that, among persons with carpal tunnel syndrome, claimants had worse outcomes than nonclaimants despite receiving more treatment; another examined the problematic relationship between complex regional pain syndrome (CRPS) and compensation and found that cases of CRPS are dominated by legal claims, a disparity that highlights the dominant role of compensation. Workers’ compensation claimants are almost never evaluated for personality disorders or mental illness. The article concludes with recommendations that evaluators can consider in individual cases.

Magnetic Properties of Fe3O4/CoFe2O4 Composite Nanoparticles with Core/Shell Architecture

2020 ◽  
Vol 65 (10) ◽  
pp. 904
Author(s):  
V. O. Zamorskyi ◽  
Ya. M. Lytvynenko ◽  
A. M. Pogorily ◽  
A. I. Tovstolytkin ◽  
S. O. Solopan ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Spinel Ferrite ◽  
Composite Nanoparticles ◽  
Core Shell ◽  
Cofe2o4 Nanoparticles ◽  
Core Diameter ◽  
The Core ◽  
Shell Particles ◽  
Interface Parameters ◽  
Shell Composite

Magnetic properties of the sets of Fe3O4(core)/CoFe2O4(shell) composite nanoparticles with a core diameter of about 6.3 nm and various shell thicknesses (0, 1.0, and 2.5 nm), as well as the mixtures of Fe3O4 and CoFe2O4 nanoparticles taken in the ratios corresponding to the core/shell material contents in the former case, have been studied. The results of magnetic research showed that the coating of magnetic nanoparticles with a shell gives rise to the appearance of two simultaneous effects: the modification of the core/shell interface parameters and the parameter change in both the nanoparticle’s core and shell themselves. As a result, the core/shell particles acquire new characteristics that are inherent neither to Fe3O4 nor to CoFe2O4. The obtained results open the way to the optimization and adaptation of the parameters of the core/shell spinel-ferrite-based nanoparticles for their application in various technological and biomedical domains.

(World Wide) Work 2.0

2016 ◽  
Vol 11 (1) ◽  
pp. 91-103
Author(s):  
Carole Cusack ◽  
David Pecotic
Keyword(s):  
Open Source ◽  
World Wide ◽  
First Generation ◽  
Dominant Role ◽  
The Internet ◽  
Digital Ethnography ◽  
Beliefs And Practices ◽  
Web Presence ◽  
Theoretical Approaches ◽  
Online Engagement

The occult and the internet intersect in four ways: as a static medium for information; as a space where contested information or ideological conflict may occur; as a facilitator of communication; and as a medium for esoteric practice. The last type of activity is rare, but it is intriguing, in that technology can shape and inform beliefs and practices in unanticipated ways. Online engagement with the ‘Work’, the movement produced by the Greek Armenian spiritual teacher and esotericist G. I. Gurdjieff (c. 1866-1949) and his immediate followers, is an under-researched instance of online esoteric practice. This article addresses this scholarly desideratum, bringing the theoretical approaches of online religion and digital ethnography to bear on the Gurdjieff Internet Guide (GIG) website, founded by Reijo Oksanen (b. 1942) and later maintained by Kristina Turner, who created an accompanying Facebook page. The GIG manifests a shift away from the sectarian secrecy of the ‘Foundation’ groups, founded by Jeanne de Salzmann (1889-1990) after Gurdjieff’s death to formalise and protect the content of the Work, and the limited web presence that the Foundation permits. The GIG moves towards an ecumenical ‘open source’ approach to the dissemination of Gurdjieff’s teachings rooted in independent groups founded by other first generation followers of Gurdjieff who remained outside of the Foundation. It is argued that the deregulation of the religious and spiritual marketplace of the contemporary West, coupled with the dominant role played by the Internet in disseminating information, has radically transformed the Gurdjieff tradition, collapsing hierarchies and esoteric strategies, democratizing access for seekers, and creating new ritual and teaching modes.

POEZJA OKSYMORONU. O METAFORYCE W WIERSZACH KRASIŃSKIEGO / THE POETRY OF THE OXYMORON: ZYGMUNT KRASIŃSKI’S VERSE

2013 ◽  
Vol 54 (3) ◽  
pp. 17-27
Author(s):  
Łukasz Niewczas
Keyword(s):  
Dominant Role

Summary This re-reading of Zygmunt Krasiński’s lyrical verse rejects (at least to some extent) the generally held view of his poetry as some kind of literary fossils. To demonstrate its genuine complexity the author of this article focuses on Krasiński’s use of the oxymoron, an aspect of his poetic art that has been neglected by the critics. The oxymoron, which seems to be his favourite metaphoric device, is analysed here on the level of poetic ontology, poetic semantics, and metaphoric imagery. In each of those spheres oxymorons play a dominant role: Krasiński uses them to construct his poetic world, to complicate and problematize his meanings, and to create a highly dramatic imagery. Finally, it is argued that the shift in Krasiński’s use of the oxymoron from a sign of cleavage to that of a balanced whole corresponds to a similar evolution in his ontological views.

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