scholarly journals The mechanism of the hydrogen-oxygen reaction. III. The influence of salts

1946 ◽  
Vol 185 (1003) ◽  
pp. 376-380 ◽  
Keyword(s):  
Reaction Rate ◽  
Chemical Interactions ◽  
Specific Chemical ◽  
Specific Effects ◽  
Oxygen System ◽  
Explosion Limits ◽  
Special Causes ◽  
Oxygen Reaction

The influence of various salts on the explosion limits and on the reaction rate of the hydrogen-oxygen system has been examined. Certain specific effects of the nature of the salts appear. Iodides differ markedly from other halides (but this may be due to special causes, such as liberation of halogen). The effects of the salts are thought to be due to specific chemical interactions.

scholarly journals On the existence of and mechanism for microwave-specific reaction rate enhancement

2015 ◽  
Vol 6 (4) ◽  
pp. 2144-2152 ◽  
Author(s):  
Gregory B. Dudley ◽  
Ranko Richert ◽  
A. E. Stiegman
Keyword(s):  
Reaction Rate ◽  
Specific Reaction Rate ◽  
Specific Chemical ◽  
Rate Enhancement ◽  
Specific Reaction ◽  
Selective Heating ◽  
Dipolar Molecules ◽  
Chemical Rate

Microwave-specific chemical rate enhancement originates from the selective heating and accumulation of energy by solvated dipolar molecules in solution.

Explosion limits of the dry carbon monoxide + oxygen reaction

1964 ◽  
Vol 60 ◽  
pp. 539 ◽  
Author(s):  
P. G. Dickens ◽  
J. E. Dove ◽  
J. W. Linnett
Keyword(s):  
Carbon Monoxide ◽  
Explosion Limits ◽  
Oxygen Reaction

A Unified Approach for the Explosion Limits of the Hydrogen-Oxygen System

2017 ◽  
Author(s):  
Alon Lidor ◽  
Daniel Weihs ◽  
Eran Sher
Keyword(s):  
Ignition Delay ◽  
Delay Time ◽  
Ignition Delay Time ◽  
Sharp Decrease ◽  
Oxygen System ◽  
Explosion Limits ◽  
Proposed Model ◽  
Explosion Limit ◽  
Model Equations ◽  
Fuel Mixtures

We present a new model for the prediction of the explosion limits of the hydrogen-oxygen system. Our model is based on the principle of ignition delay time, postulating that crossing the explosion limit (by increasing the pressure or temperature above it) causes a sharp decrease in the ignition delay time. By using fundamentals of the chain ignition theory, and by employing the Le-Chatelier rule for the explosion limits of fuel mixtures, we develop our model equations. We use numerical analysis to calibrate the constants, and show that our proposed model can accurately capture the unique trend of the peninsula shaped explosion limits. We believe that the relative simplicity of our model will be useful in the analysis of more complex hydrocarbon fuels.

scholarly journals High-molecular-weight polymers from dietary fiber drive aggregation of particulates in the murine small intestine

2018 ◽  
Author(s):  
Asher Preska Steinberg ◽  
Sujit S. Datta ◽  
Thomas Naragon ◽  
Justin C. Rolando ◽  
Said R. Bogatyrev ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Small Intestine ◽  
Dietary Fiber ◽  
High Molecular Weight ◽  
Ex Vivo ◽  
Dietary Fibers ◽  
Chemical Interactions ◽  
Specific Chemical ◽  
Molecular Weights ◽  
Particulate Suspension

AbstractThe lumen of the small intestine (SI) is filled with particulates: microbes, therapeutic particles, and food granules. The structure of this particulate suspension could impact uptake of drugs and nutrients and the function of microorganisms; however, little is understood about how this suspension is re-structured as it transits the gut. Here, we demonstrate that particles spontaneously aggregate in SI luminal fluidex vivo. We find that mucins and immunoglobulins are not required for aggregation. Instead, aggregation can be controlled using polymers from dietary fiber in a manner that is qualitatively consistent with polymer-induced depletion interactions, which do not require specific chemical interactions. Furthermore, we find that aggregation is tunable; by feeding mice dietary fibers of different molecular weights, we can control aggregation in SI luminal fluid. This work suggests that the molecular weight and concentration of dietary polymers play an underappreciated role in shaping the physicochemical environment of the gut.

Some features of the gas phase oxidation of n -butenes

1963 ◽  
Vol 272 (1349) ◽  
pp. 164-191 ◽  
Keyword(s):  
Gas Phase ◽  
Reaction Rate ◽  
Reaction Rates ◽  
Maximum Reaction Rate ◽  
Oxygen System ◽  
Maximum Reaction ◽  
Phase Oxidation ◽  
Gas Phase Oxidation ◽  
Analytical System ◽  
The Individual

Conventional kinetic techniques (static and flow systems) have been used in conjunction with an integral gas chromatographic analytical system in a study of the oxidation behaviour of butene-1, cis butene-2 and trans butene-2. The cis and trans isomers of butene-2 behaved indistinguishably. All three olefins gave qualitatively the same products, but butene-1 differed in the proportions of the individual products formed, and also in oxidation rate. A mechanism, based on that previously proposed for the ethylene + oxygen system, has been found to account for these differences. The ethylene mechanism is only possible, however, because of the slow rate of oxidation of the allylic type radicals easily formed in the reactions. The relative stability of these radicals provides a natural explanation of the phenomenon of self-inhibition observed in olefin + oxygen reactions. The discontinuous production of intermediate substances noted during the oxidation of butene-2 at high reaction rates, provides further evidence for a thermal theory of cool-fiame formation. Acetaldehyde has been found to be the degenerate branching agent and the maximum reaction rate of these systems was found to be identically related to the concentration of this substance.

Oxidation of DL-penicillamine by chromium(VI). Kinetics of formation of the thioester intermediate

1994 ◽  
Vol 72 (7) ◽  
pp. 1637-1644 ◽  
Author(s):  
Joaquin F. Perez-Benito ◽  
Driss Lamrhari ◽  
Conchita Arias
Keyword(s):  
Reaction Rate ◽  
Aqueous Media ◽  
Bimolecular Reaction ◽  
Spectrophotometric Detection ◽  
State Behavior ◽  
Chromium Vi ◽  
Specific Effects ◽  
Kinetics Of Formation ◽  
Kinetics Of ◽  
Catalytic Power

The kinetics of formation of the thioester involved as an intermediate in the reaction between chromium(VI) and DL-penicillamine in aqueous media (pH = 1–8) containing different buffers (acetate, citrate, and phosphate) has been studied by monitoring the disappearance of chromium(VI) at 370 nm and application of the initial-rates method. The initial rate is directly proportional to the initial concentrations of both oxidant and reductant, and the rate vs. pH plots show bell-shaped profiles. The reaction is catalyzed by the buffer present in the medium, the catalytic power of each buffer increasing in the order acetate < citrate < phosphate. This is explained in terms of a mechanism involving the formation of a complex between the acidic form of the buffer and HCrO4− previous to the formation of the thioester. Potassium chloride and sodium sulfate do not seem to have important specific effects on the reaction rate, their effect being that of an acceleration of the reaction as the ionic strength increases. On the contrary, the sulfates of magnesium, manganese(II), and zinc (the latter only in the presence of acetate buffer) have specific effects, indicating the probable formation of several complexes. The spectrophotometric detection of the thioester at 430 nm has allowed to confirm some of the conclusions extracted from the measurement of initial rates, and suggests that this intermediate might approach a steady-state behavior in the three buffers at pH > 6.25, and also that a bimolecular reaction with DL-penicillamine might be involved in its destruction.

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