scholarly journals Effect of Liquid Transparency on Laser-Induced Motion of Drops

2009 ◽  
Vol 131 (8) ◽  
Author(s):  
R. Shukla ◽  
K. A. Sallam
Keyword(s):  
Laser Beam ◽  
Rhodamine 6G ◽  
Marangoni Effect ◽  
Video Camera ◽  
Solid Substrate ◽  
Liquid Drops ◽  
Induced Motion ◽  
532 Nm ◽  
Rhodamine 6G Dye

An experimental investigation of the role of liquid transparency in controlling laser-induced motion of liquid drops is carried out. The study was motivated by application to manipulation of liquid drops over a solid substrate. Droplets with diameters of 1–4 mm were propelled on a hydrophobic substrate using a pulsed-laser beam (532 nm, 10 Hz, 3–12 mJ/pulse) with a 0.9 mm diameter fired parallel to the substrate. The test liquid was distilled water whose transparency was varied by adding different concentrations of Rhodamine 6G dye. Motion of the drops was observed using a video camera. Measurements include direction of motion and the distance traveled before the drops come to rest. The present results show that the direction of the motion depends on the drop transparency; opaque drops moved away from the laser beam, whereas transparent drops moved at small angles toward the laser beam. The motion of both transparent and opaque drops was dominated by thermal Marangoni effect; the motion of opaque drops was due to direct heating by the laser beam, whereas in the case of transparent drops, the laser beam was focused near the rear face of the transparent drops to form a spark that pushed the drops in the opposite direction. Energies lower than 3 mJ were incapable of moving the drops, and energies higher than 12 mJ shattered the drops instead of moving them. A phenomenological model was developed for the drop motion to explain the physics behind the phenomenon.

On the Role of Marangoni Effects on the Critical Heat Flux for Pool Boiling of Binary Mixtures

1996 ◽  
Vol 118 (1) ◽  
pp. 103-109 ◽  
Author(s):  
W. R. McGillis ◽  
V. P. Carey
Keyword(s):  
Surface Tension ◽  
Heat Flux ◽  
Binary Mixtures ◽  
Critical Heat Flux ◽  
Full Range ◽  
Pool Boiling ◽  
Marangoni Effect ◽  
Restoring Force ◽  
Marangoni Effects

The Marangoni effect on the critical heat flux (CHF) condition in pool boiling of binary mixtures has been identified and its effect has been quantitatively estimated with a modified model derived from hydrodynamics. The physical process of CHF in binary mixtures, and models used to describe it, are examined in the light of recent experimental evidence, accurate mixture properties, and phase equilibrium revealing a correlation to surface tension gradients and volatility. A correlation is developed from a heuristic model including the additional liquid restoring force caused by surface tension gradients. The CHF condition was determined experimentally for saturated methanol/water, 2-propanol/water, and ethylene glycol/water mixtures, over the full range of concentrations, and compared to the model. The evidence in this study demonstrates that in a mixture with large differences in surface tension, there is an additional hydrodynamic restoring force affecting the CHF condition.

scholarly journals Sarocladium and Lecanicillium Associated with Maize Seeds and Their Potential to Form Selected Secondary Metabolites

Biomolecules ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 98
Author(s):  
Lidia Błaszczyk ◽  
Agnieszka Waśkiewicz ◽  
Karolina Gromadzka ◽  
Katarzyna Mikołajczak ◽  
Jerzy Chełkowski
Keyword(s):  
Large Subunit ◽  
Solid Substrate ◽  
Rrna Gene ◽  
Decenoic Acid ◽  
Bioactive Substances ◽  
Lecanicillium Lecanii ◽  
Maize Seeds ◽  
Internally Transcribed Spacer ◽  
First Time

The occurrence and diversity of Lecanicillium and Sarocladium in maize seeds and their role in this cereal are poorly understood. Therefore, the present study aimed to investigate Sarocladium and Lecanicillium communities found in endosphere of maize seeds collected from fields in Poland and their potential to form selected bioactive substances. The sequencing of the internally transcribed spacer regions 1 (ITS 1) and 2 (ITS2) and the large-subunit (LSU, 28S) of the rRNA gene cluster resulted in the identification of 17 Sarocladium zeae strains, three Sarocladium strictum and five Lecanicillium lecanii isolates. The assay on solid substrate showed that S. zeae and S. strictum can synthesize bassianolide, vertilecanin A, vertilecanin A methyl ester, 2-decenedioic acid and 10-hydroxy-8-decenoic acid. This is also the first study revealing the ability of these two species to produce beauvericin and enniatin B1, respectively. Moreover, for the first time in the present investigation, pyrrocidine A and/or B have been annotated as metabolites of S. strictum and L. lecanii. The production of toxic, insecticidal and antibacterial compounds in cultures of S. strictum, S. zeae and L. lecanii suggests the requirement to revise the approach to study the biological role of fungi inhabiting maize seeds.

Encapsulating toxic Rhodamine 6G dye, and Cr (VI) metal ions from liquid phase using AlPO4-5 molecular sieves. Preparation, characterization, and adsorption parameters

2021 ◽  
pp. 116549
Author(s):  
Anjani R.K. Gollakota ◽  
Venkata Subbaiah Munagapati ◽  
Krishna Prasad Shadangi ◽  
Guda Mallikarjuna Reddy ◽  
Jet-Chau Wen ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Metal Ions ◽  
Molecular Sieves ◽  
Rhodamine 6G ◽  
Adsorption Parameters ◽  
Rhodamine 6G Dye

scholarly journals The role of drop shape in impact and splash

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Qingzhe Liu ◽  
Jack Hau Yung Lo ◽  
Ye Li ◽  
Yuan Liu ◽  
Jinyu Zhao ◽  
...  
Keyword(s):  
Electromagnetic Field ◽  
Spherical Geometry ◽  
Impact Dynamics ◽  
Helmholtz Instability ◽  
Liquid Drops ◽  
Drop Shape ◽  
Spreading Dynamics ◽  
Solid Substrates ◽  
The Impact

AbstractThe impact and splash of liquid drops on solid substrates are ubiquitous in many important fields. However, previous studies have mainly focused on spherical drops while the non-spherical situations, such as raindrops, charged drops, oscillating drops, and drops affected by electromagnetic field, remain largely unexplored. Using ferrofluid, we realize various drop shapes and illustrate the fundamental role of shape in impact and splash. Experiments show that different drop shapes produce large variations in spreading dynamics, splash onset, and splash amount. However, underlying all these variations we discover universal mechanisms across various drop shapes: the impact dynamics is governed by the superellipse model, the splash onset is triggered by the Kelvin-Helmholtz instability, and the amount of splash is determined by the energy dissipation before liquid taking off. Our study generalizes the drop impact research beyond the spherical geometry, and reveals the potential of using drop shape to control impact and splash.

Neoplastic conversion of preneoplastic Syrian hamster cells: rate estimation by fluctuation analysis

1983 ◽  
Vol 3 (5) ◽  
pp. 931-945
Author(s):  
B D Crawford ◽  
J C Barrett ◽  
P O Ts'o
Keyword(s):  
Syrian Hamster ◽  
Neoplastic Transformation ◽  
Solid Substrate ◽  
Established Cell Line ◽  
Fluctuation Analysis ◽  
Neoplastic Progression ◽  
Early Passage

Analysis of the role of gene mutations in the multistep process of neoplastic transformation requires that the discrete steps in carcinogenesis first be dissected. Toward this end, we have isolated and characterized preneoplastic Syrian hamster cells which exhibit in vitro a trait highly correlated with neoplastic conversion in vivo. Previous findings (J. C. Barrett, Cancer Res. 40:91-94, 1980) indicate that spontaneous neoplastic transformation of Syrian hamster cells occurs in at least two steps. An intermediate stage, characterized by an aneuploid established cell line which has a propensity to become neoplastic spontaneously upon further growth in vitro, has been described. These preneoplastic cells differ from diploid early-passage Syrian hamster cells in becoming capable of anchorage-independent growth in semisolid agar, as well as becoming neoplastic in vivo when attached to a solid substrate. Evidence presented here demonstrates that anchorage-independent conversion in vitro is a reliable marker for neoplastic conversion in this cell system. Fluctuation analyses, patterned after those described by Luria and Delbruck for microbial genetics, demonstrate that anchorage-independent variants are generated randomly from clonally derived preneoplastic cells at the rate of 10(-8) to 10(-7) variants per cell per generation. These results establish a multistep stochastic process for transformation in vitro and indicate that conversion to anchorage independence may be necessary for Syrian hamster cells to become tumorigenic. The possible role of gene mutation in this step during neoplastic progression is discussed.

Probing the microscopic structural organization of neat ionic liquids (ILs) and ionic liquid-based gels through resonance energy transfer (RET) studies

2017 ◽  
Vol 19 (34) ◽  
pp. 23194-23203 ◽  
Author(s):  
Debashis Majhi ◽  
Moloy Sarkar
Keyword(s):  
Ionic Liquid ◽  
Energy Transfer ◽  
Ionic Liquids ◽  
Structural Organization ◽  
Rhodamine 6G ◽  
Resonance Energy Transfer ◽  
Resonance Energy

With the aim to understand the role of the ionic constituents of ionic liquids (ILs) in their structural organization, resonance energy transfer (RET) studies between ionic liquids (donor) and rhodamine 6G (acceptor) have been investigated.

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