scholarly journals Speeding up biphasic reactions with surface nanodroplets

Lab on a Chip ◽  
2020 ◽  
Vol 20 (16) ◽  
pp. 2965-2974
Author(s):  
Zhengxin Li ◽  
Akihito Kiyama ◽  
Hongbo Zeng ◽  
Detlef Lohse ◽  
Xuehua Zhang
Keyword(s):  
Reaction Time ◽  
Mass Transport ◽  
Time Scales ◽  
Biphasic Reaction ◽  
Kinetics Of ◽  
Reactant Flow

The kinetics of a model biphasic reaction at the interface of surface nanodroplets is quantitatively studied. The droplet reaction time scales with ∼Pe−2/3 of the reactant flow. Enhanced mass transport contributes to accelerated kinetics.

KINETICS OF ELECTROCHEMICAL REACTIONS ON MODEL SUPPORTED CATALYSTS: READSORPTION AND MASS TRANSPORT

2008 ◽  
Vol 15 (06) ◽  
pp. 745-751
Author(s):  
VLADIMIR P. ZHDANOV ◽  
BENGT KASEMO
Keyword(s):  
Mass Transport ◽  
Supported Catalysts ◽  
Reaction Scheme ◽  
Electrochemical Reactions ◽  
Subsequent Reaction ◽  
Flow Cells ◽  
2D And 3D ◽  
Kinetics Of ◽  
And Diffusion

To bridge the structure gap, electrochemical reactions can be studied in flow cells with nm-sized catalyst particles deposited or fabricated on the cell walls. The understanding of the role of mass transport in such cells is now limited. To clarify the likely effects in this field, we analyze the simplest reaction scheme including intermediate desorption, readsorption, and subsequent reaction and show how the net rate of the formation of intermediate can be influenced by its diffusion in the liquid phase. With certain approximations, we derive analytical results describing reaction and diffusion near catalyst particles and in more remote regions in the simplest 1D case and more complex 2D and 3D situations.

The Effect of Membrane Treatment on Chlorine Decay and Trihalomethanes Formation in Water Distribution Systems

2013 ◽  
Vol 316-317 ◽  
pp. 703-706
Author(s):  
Tao Tao Zhao ◽  
Cong Li ◽  
Hong Liang Yu ◽  
Zi Long Wang ◽  
Ba Yi Er Minda ◽  
...  
Keyword(s):  
Reaction Time ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Clear Understanding ◽  
Exponential Relationship ◽  
Chlorine Decay ◽  
Membrane Treatment ◽  
Kinetics Of ◽  
Trihalomethanes Formation

The experiment was carried out to measure the effect of membrane treatment on the kinetics of chlorine decay in PE pipes in the water distribution systems. The results revealed that water had the potential to form halomethane compounds with chloroform being the most dominant. The formation of THMs is no longer relatively exponential relationship with the reaction time, but also decided by complex elements, including DOC, pH, conductivity, flow rate, and several other indexes. Since Chloroform (CHCl3) has the maximum concentration of the four THMs, clear understanding of its causes, pathway and mechanism will help to regulate and solve the THMs problem.

scholarly journals Enzyme kinetics of CRISPR molecular diagnostics

2021 ◽  
Author(s):  
Ashwin Ramachandran ◽  
Juan G. Santiago
Keyword(s):  
Reaction Time ◽  
Enzyme Kinetics ◽  
Molecular Diagnostics ◽  
Analytical Solutions ◽  
Rapid Testing ◽  
Kinetics Parameters ◽  
Diagnostic Assays ◽  
Degree Of Reaction ◽  
Significant Interest ◽  
Kinetics Of

AbstractCRISPR diagnostic assays have gained significant interest in the last few years. This interest has grown rapidly during the current COVID-19 pandemic where CRISPR diagnostics have been frontline contenders for rapid testing solutions. This surge in CRISPR diagnostics research prompts the following question: What exactly are the achievable limits of detection and associated assay times enabled by the kinetics of Cas12 and Cas13 enzymes? To address this question, we here present a model based on Michaelis-Menten enzyme kinetics theory applied to Cas enzymes. We use the model to develop analytical solutions for reaction kinetics and develop back-of-the­ envelope criteria to validate and check for consistency in reported enzyme kinetics parameters. We applied our analyses to all studies known to us which report Michaelis-Menten-type kinetics data for CRISPR associated enzymes. These studies include all subtypes of Cas12 and Cas13 and orthologs. We found all studies but one clearly violate at least two of our three rules of consistency. We further use our model to explore ranges of reaction time scales and degree of reaction completion for practically relevant target concentrations applicable to CRISPR-diagnostic assays.

scholarly journals A phenomenological analysis of sintering kinetics from the viewpoint of activated volume

2005 ◽  
Vol 37 (1) ◽  
pp. 19-25 ◽  
Author(s):  
M.V. Nikolic ◽  
Nebojsa Labus ◽  
Momcilo Ristic
Keyword(s):  
Mass Transport ◽  
Point Defects ◽  
Phenomenological Analysis ◽  
Sintering Process ◽  
Phenomenological Equation ◽  
Disperse Systems ◽  
Sintering Kinetics ◽  
Kinetics Of

The sintering kinetics of real systems has been viewed as a process of transport of activated volume. Activated volume is a parameter that can be used to describe mass transport during the sintering process. It defines the movement of point defects and dislocations during the sintering process. A phenomenological equation has been defined using this parameter, which can be applied to analyze kinetics of the sintering process. It has been applied to analyze the sintering process of several disperse systems. Values obtained for parameters of the equation have also been analyzed.

scholarly journals Universal kinetics of imperfect reactions in confinement

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Thomas Guérin ◽  
Maxim Dolgushev ◽  
Olivier Bénichou ◽  
Raphaël Voituriez
Keyword(s):  
Reaction Time ◽  
Transport Process ◽  
Reaction Times ◽  
Complex Environments ◽  
Analytical Treatment ◽  
Volume Limit ◽  
Normal Diffusion ◽  
The Mean ◽  
Kinetics Of ◽  
Mean Reaction Time

AbstractChemical reactions generically require that particles come into contact. In practice, reaction is often imperfect and can necessitate multiple random encounters between reactants. In confined geometries, despite notable recent advances, there is to date no general analytical treatment of such imperfect transport-limited reaction kinetics. Here, we determine the kinetics of imperfect reactions in confining domains for any diffusive or anomalously diffusive Markovian transport process, and for different models of imperfect reactivity. We show that the full distribution of reaction times is obtained in the large confining volume limit from the knowledge of the mean reaction time only, which we determine explicitly. This distribution for imperfect reactions is found to be identical to that of perfect reactions upon an appropriate rescaling of parameters, which highlights the robustness of our results. Strikingly, this holds true even in the regime of low reactivity where the mean reaction time is independent of the transport process, and can lead to large fluctuations of the reaction time - even in simple reaction schemes. We illustrate our results for normal diffusion in domains of generic shape, and for anomalous diffusion in complex environments, where our predictions are confirmed by numerical simulations.

The Vulcanization of Elastomers. X. The Vulcanization of Natural Rubber with Thiuram Disulfides (V)

1957 ◽  
Vol 30 (3) ◽  
pp. 903-910
Author(s):  
Otto Lorenz ◽  
Walter Scheele ◽  
Wolfgang Redetzky
Keyword(s):  
Reaction Time ◽  
Natural Rubber ◽  
First Order ◽  
Wide Range ◽  
Identical Rate ◽  
Tetraethylthiuram Disulfide ◽  
Kinetics Of

Abstract The kinetics of crosslinking natural rubber during vulcanization with tetramethyl and tetraethylthiuram disulfide was investigated. The following results were derived: 1. The increase of crosslinking during vulcanization which was measured by the change of reciprocal swelling is first order over a wide range of reaction time and temperature. 2. During vulcanization, crosslinking and dithiocarbamate formation are reactions which proceed with identical rate. From this we had to conclude that the formation of dithiocarbamate is the immediate cause of the crosslink formation. 3. The concentration of the thiuram disulfide decreases much faster with respect to vulcanization time than crosslinking increases. In other words, the thiuram decrease can only be considered a reaction which precedes crosslinking.

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