Correlation between the inhibition of positronium formation by scavenger molecules, and chemical reaction rate of electrons with these molecules in nonpolar liquids

1977 ◽  
Vol 81 (5) ◽  
pp. 373-377 ◽  
Author(s):  
Bela Levay ◽  
Ole E. Mogensen
Keyword(s):  
Chemical Reaction ◽  
Reaction Rate ◽  
Positronium Formation ◽  
Nonpolar Liquids ◽  
Chemical Reaction Rate

Diffusion and Mixing in Microchannel Analyzed by the Luminol Chemiluminescence

2013 ◽  
Author(s):  
Ruru Matsuo ◽  
Ryosuke Matsumoto
Keyword(s):  
Numerical Simulation ◽  
Chemical Reaction ◽  
Reaction Rate ◽  
Mixing Layer ◽  
Fluorescence Technique ◽  
Chemiluminescence Intensity ◽  
Luminol Chemiluminescence ◽  
Chemical Reaction Rate ◽  
Pdms Chip ◽  
Reaction Profile

This study focused on the diffusion and mixing phenomena investigated by using luminol chemiluminescence (CL) to estimate the local chemical reaction rate in the T-junction microchannel. Generally, the degree of mixing in microchannel is calculated by the deviation of the obtained concentration profiles from the uniform concentration profile by using fluorescence technique. Thus, the degree of mixing is a macroscopic estimate for the whole microchannel, which is inappropriate for understanding the diffusion and mixing phenomena in the mixing layer. In this study, the luminol CL reaction is applied to visualize the local chemical reaction and to estimate the local diffusion and mixing phenomena at an interface between two liquids in microchannel. Luminol emits blue chemiluminescence when it reacts with the hydrogen peroxide at the mixing layer. Experiments were carried out on the T-junction microchannel with 200 microns in width and 50 microns in depth casted in the PDMS chip. The chemiluminescence intensity profiles clearly show the mixing layer at an interface between two liquids. The experimental results are compared with the results of numerical simulation that involves solving the mass transport equations including the chemical reaction term. By calibrating CL intensity to the chemical reaction rate estimated by the numerical simulation, the local chemical reaction profile can be quantitatively estimated from the CL intensity profile.

ChemInform Abstract: ENHANCEMENT OF A CHEMICAL REACTION RATE BY PROPER ORIENTATION OF REACTING MOLECULES IN THE SOLID STATE

1975 ◽  
Vol 6 (46) ◽  
pp. no-no
Author(s):  
CHAIM N. SUKENIK ◽  
JOSE A. P. BONAPACE ◽  
NEIL S. MANDEL ◽  
ROBERT G. BERGMAN ◽  
PUI-YAN LAU ◽  
...  
Keyword(s):  
Solid State ◽  
Chemical Reaction ◽  
Reaction Rate ◽  
Chemical Reaction Rate ◽  
Proper Orientation

scholarly journals The Role Of Chemical Reaction In Waste-Form Performance

1987 ◽  
Vol 112 ◽  
Author(s):  
P. L. Chambré ◽  
C. H. Kang ◽  
W. W.-L. Lee ◽  
T. H. Pigford
Keyword(s):  
Mass Transfer ◽  
Steady State ◽  
Dissolution Rate ◽  
Chemical Reaction ◽  
Borosilicate Glass ◽  
Reaction Rate ◽  
Waste Form ◽  
Spent Fuel ◽  
Wide Range ◽  
Chemical Reaction Rate

AbstractThe dissolution rate of waste solids in a geologic repository is a complex function of waste form geometry, chemical reaction rate, exterior flow field, and chemical environment. We present here an analysis to determine the steady-state mass transfer rate, over the entire range of flow conditions relevant to geologic disposal of nuclear waste. The equations for steady-state mass transfer with a chemical-reaction-rate boundary condition are solved by three different mathematical techniques which supplement each other. This theory is illustrated with laboratory leach data for borosilicate-glass and a spherical spent-fuel waste form under typical repository conditions. For borosilicate glass waste in the temperature range of 57°C to 250°C, dissolution rate in a repository is determined for a wide range of chemical reaction rates and for Peclet numbers from zero to well over 100, far beyond any Peclet values expected in a repository. Spent-fuel dissolution in a repository is also investigated, based on the limited leach data now available.

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