Time-resolved detection of diffusion limited temperature gradients inside single isolated burning droplets using Rainbow Refractometry

2016 ◽  
Vol 168 ◽  
pp. 255-269 ◽  
Author(s):  
Christopher D. Rosebrock ◽  
Saeideh Shirinzadeh ◽  
Mathias Soeken ◽  
Norbert Riefler ◽  
Thomas Wriedt ◽  
...  
Keyword(s):  
Temperature Gradients ◽  
Time Resolved ◽  
Diffusion Limited ◽  
Limited Temperature ◽  
Rainbow Refractometry

scholarly journals Change of evaporation rate of single monocomponent droplet with temperature using time-resolved phase rainbow refractometry

2019 ◽  
Vol 37 (3) ◽  
pp. 3211-3218 ◽  
Author(s):  
Yingchun Wu ◽  
Haipeng Li ◽  
Xuecheng Wu ◽  
Gérard Gréhan ◽  
Lutz Mädler ◽  
...  
Keyword(s):  
Evaporation Rate ◽  
Time Resolved ◽  
Rainbow Refractometry

A Detailed Examination of Time-Resolved Pulsed Raman Temeperature Measurements of Laser Annealed Silicon

1983 ◽  
Vol 13 ◽  
Author(s):  
G. E. Jellison ◽  
D. H. Lowndes ◽  
R. F. Wood
Keyword(s):  
Optical Properties ◽  
Pulse Width ◽  
Laser Annealing ◽  
Pulsed Laser ◽  
Detailed Examination ◽  
Temperature Gradients ◽  
Probe Laser ◽  
Time Resolved ◽  
Pulsed Laser Annealing ◽  
Anti Stokes

ABSTRACTRaman temperature measurements during pulsed laser annealing of Si by Compaan and co-workers are critically examined. It has been shown previously that the Stokes to anti-Stokes ratio depends critically upon the optical properties of silicon as a function of temperature. These dependences, coupled with the large spatial and temporal temperature gradients normally found immediately after the high reflectivity phase, result in large variations in the calculated temperature depending upon the probe laser pulse width and the pulse-to-pulse and spatial variations in the annealing pulse energy density.

Influence of Electrolytes and Humic Acid on Aggregation Behavior of C60 Nanoparticles in Aquatic System

2013 ◽  
Vol 448-453 ◽  
pp. 48-51
Author(s):  
Hua Fang ◽  
Bing Bing Shen ◽  
Yu Xin Sun ◽  
Yuan Wang ◽  
Ji Lai Lu
Keyword(s):  
Humic Acid ◽  
Colloidal Stability ◽  
Dlvo Theory ◽  
Aquatic Environments ◽  
Aggregation Kinetics ◽  
Time Resolved ◽  
Diffusion Limited ◽  
Wide Range ◽  
Kinetics Of ◽  
And Diffusion

The aggregation kinetics of C60 nanoparticles have been investigated over a wide range of monovalent and divalent electrolyte concentrations by employing time-resolved dynamic light scattering (DLS). The results showed that the presence of electrolyte made a dramatic decrease in the surface zeta potential and increase in the particle size. The aggregation kinetics of C60 nanoparticles exhibited reaction-limited and diffusion-limited regimes, which was found to be consistent with the classic Derjaguin-Landau-Verwey-Overbeek (DLVO) theory of colloidal stability. The critical coagulation concentration (CCC) values of C60 nanoparticles were estimated as 321mM Na+, 295mM K+, 9.6mM Ca2+and 6.7mM Mg2+, which were far higher than the electrolyte concentrations in natural water. The enhanced C60 stability in the presence of humic acid was attributable to steric repulsion. Therefore C60 nanoparticles can be relatively stable in typical aquatic environments.

Investigation of Evaporation and Diffusion Phenomena in Porous Media

2007 ◽  
Vol 553 ◽  
pp. 215-222
Author(s):  
Rachid Bennacer ◽  
Khellil Sefiane
Keyword(s):  
Porous Media ◽  
Thermal Field ◽  
Molecular Diffusion ◽  
Temperature Gradients ◽  
Diffusion Limited ◽  
Biological Phenomena ◽  
Steady Stage ◽  
Controlling Mechanism ◽  
Diffusion Phenomena ◽  
And Diffusion

Many industrial and biological phenomena involve the evaporation of liquids in porous media. In drying processes the evaporation of a liquid meniscus from the solid is the key mechanism in the process and its efficiency. After a first steady stage of evaporation the meniscus becomes unsteady and recedes inside the pore. Diffusion of vapour becomes the controlling mechanism for evaporation in a later stage. In this work an experimental investigation is undertaken to study the various stages of evaporation of different liquids in capillary tubes (pores) of various sizes. The analysis of the data obtained from this investigation reveals some interesting behaviours and emphasizes the role played by vapour diffusion in the case of unsteady interface. The preliminary transient regime allowing the thermal field establishment, is followed by the first stage of evaporation is found to be dominated by thermocapillary effects associated with non-uniform evaporation and temperature gradients. The laste stage is a molecular diffusion-limited mode. The liquid volatility and the effect of the size of the tube (ranging from 200 to 900 μm) are also analysed to show the interaction between the various effects at different scales.

scholarly journals Fluorescence Quenching Studies on the Interactions between Chosen Fluoroquinolones and Selected Stable TEMPO and PROXYL Nitroxides

2021 ◽  
Vol 22 (2) ◽  
pp. 885
Author(s):  
Krzysztof Żamojć ◽  
Irena Bylińska ◽  
Wiesław Wiczk ◽  
Lech Chmurzyński
Keyword(s):  
Fluorescence Quenching ◽  
Rate Constants ◽  
Quenching Rate ◽  
Time Resolved ◽  
Radiative Processes ◽  
Diffusion Limited ◽  
Fluoroquinolone Antibiotics ◽  
Quenching Efficiency ◽  
Bimolecular Quenching ◽  
The Impact

The influence of the stable 2,2,6,6-tetramethylpiperidinyl-N-oxyl (TEMPO) nitroxide and its six C4-substituted derivatives, as well as two C3-substituted analogues of 2,2,5,5-tetramethylpyrrolidynyl-N-oxyl (PROXYL) nitroxide on the chosen fluoroquinolone antibiotics (marbofloxacin, ciprofloxacin, danofloxacin, norfloxacin, enrofloxacin, levofloxacin and ofloxacin), has been examined in aqueous solutions by UV absorption as well as steady-state and time-resolved fluorescence spectroscopies. The mechanism of fluorescence quenching has been specified and proved to be purely dynamic (collisional) for all the studied systems, which was additionally confirmed by temperature dependence experiments. Moreover, the selected quenching parameters—that is, Stern–Volmer quenching constants and bimolecular quenching rate constants—have been determined and explained. The possibility of electron transfer was ruled out, and the quenching was found to be diffusion-limited, being a result of the increase in non-radiative processes. Furthermore, as the chosen nitroxides affected the fluorescence of fluoroquinolone antibiotics in different ways, an influence of the structure and the type of substituents in the molecules of both fluoroquinolones and stable radicals on the quenching efficiency has been determined and discussed. Finally, the impact of the solvent’s polarity on the values of bimolecular quenching rate constants has been explained. The significance of the project comes from many applications of nitroxides in chemistry, biology and industry.

Time-Resolved Study of Silicon During Pulsed-Laser Annealing

1983 ◽  
Vol 13 ◽  
Author(s):  
B. C. Larson ◽  
C. W. White ◽  
T. S. Noggle ◽  
J. F. Barhorst ◽  
D. M. Mills
Keyword(s):  
Laser Annealing ◽  
Pulsed Laser ◽  
Laser Pulses ◽  
High Energy ◽  
Temperature Gradients ◽  
Time Resolved ◽  
Synchrotron Source ◽  
Near Surface ◽  
Solid Interface ◽  
Pulsed Laser Annealing

ABSTRACTNear surface temperatures and temperature gradients have been studied in silicon during pulsed laser annealing. The investigation was carried out using nanosecond resolution x-ray diffraction measurements made at the Cornell High Energy Synchrotron Source. Thermal-induced-strain analyses of these real-time, extended Bragg scattering measurements have shown that the lattice temperature reached the melting point during 15 ns, 1.1–1.5 J/cm2 ruby laser pulses and that the temperature of the liquid-solid interface remained at that temperature throughout the high reflectivity phase, after which time the surface temperature subsided rapidly. The temperature gradients below the liquid-solid interface were found to be in the range of 107°C/cm.

Rotation of small fluorophores in cell cytoplasm measured by confocal anisotropy imaging and picosecond microfluorimetry

1991 ◽  
Vol 49 ◽  
pp. 230-231
Author(s):  
A.S. Verkman ◽  
J.A. Dix ◽  
M. Armijo ◽  
K. Fushimi
Keyword(s):  
Argon Laser ◽  
Tracer Diffusion ◽  
Cell Cytoplasm ◽  
Intact Cells ◽  
Time Resolved ◽  
Diffusion Limited ◽  
Wide Range ◽  
Photobleaching Recovery ◽  
Theological Properties ◽  
Phase Angles

The Theological properties of cell cytoplasm are of importance for a number of intracellular processes including diffusion-limited enzyme reactions, intracellular vesicle trafficking, solute transport and cell motility. A wide range of cytoplasmic viscosities have been reported from fluorescence anisotropy, photobleaching recovery, tracer diffusion and electron spin resonance methods. To examine the viscosity of the fluid space between macromolecules and cytoskeletal structures in intact cells, the time-resolved picosecond motion of small fluorophores was measured. Unlike previous methods, measurements of time-resolved fluorophore motion are not confounded by probe binding to and restriction by intracellular structures.Picosecond anisotropy decay was measured by multi-harmonic phase modulation microfluorimetry. The excitation source was a 9 watt argon laser which was impulse modulated by a Pockel's cell. Light was polarized and focused onto a < 1 μ spot on a fluorescently labelled cell. Emitted light was filtered and detected by a phase sensitive photomultiplier through a rotatable analyzing polarizer. Thirty to forty pairs of differential modulation amplitudes and phase angles were collected in parallel over the frequency range 5 to 250 MHz.

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