ATOMIC REACTIONS IN THE UPPER ATMOSPHERE

1960 ◽  
Vol 38 (10) ◽  
pp. 1688-1692 ◽  
Author(s):  
Joseph Kaplan ◽  
William J. Schade ◽  
Charles A. Barth ◽  
Alvin F. Hildebrandt
Keyword(s):  
Nitric Oxide ◽  
Oxygen Atom ◽  
Chemical Reactions ◽  
Digital Computer ◽  
Atomic Oxygen ◽  
Flow System ◽  
Reaction Rates ◽  
Upper Atmosphere ◽  
Atomic Nitrogen ◽  
Excitation Mechanism

The reaction rates of nine upper atmosphere chemical reactions have been analyzed with a digital computer. The dependence of the loss rates of atomic nitrogen and atomic oxygen as well as the relative concentrations of nitric oxide and nitrogen dioxide in the upper atmosphere are given. Using a flow system, nitrogen atoms were produced and then titrated by the addition of NO. The resulting nitrogen and oxygen atom densities were measured with an e.p.r. spectrometer. The dependence of the intensities of the nitrogen afterglow and the NO afterglow were related to the atom densities. An excitation mechanism for OI 5577 has been determined from the relation of the intensity of λ 5577 to the atom densities.

The air afterglow and its use in the study of some reactions of atomic oxygen

1958 ◽  
Vol 247 (1248) ◽  
pp. 123-139 ◽  
Keyword(s):  
Nitric Oxide ◽  
Steady State ◽  
Atomic Oxygen ◽  
Microwave Discharge ◽  
Flow System ◽  
Glass Tube ◽  
Inert Gases ◽  
Spatial Decay ◽  
Greenish Yellow ◽  
Catalytic Recombination

The air afterglow has been studied in a flow system by mixing the products of a microwave discharge in oxygen with NO or mixtures of gases and by measuring the intensity of the glow immediately past the point of mixing and farther downstream in a long glass tube at known pressure, composition, and linear velocity of flow. The intensity of the greenish yellow chemiluminescence is shown to be proportional to the concentrations of atomic oxygen and nitric oxide, and independent of the nature or amount of added inert gases. An average quantum (5500 Å) is emitted for every 10 7 collisions of O with NO. The concentration of atomic oxygen is determined by a 'titration with NO 2 in which the end-point is indicated by complete extinction of the glow all along the tube, and which is made possible by the great speed of the reaction O + NO 2 → O 2 + NO. Observation of the spatial decay of the glow under steady-state conditions is well suited to the study of reactions of atomic oxygen. The concentration of NO remains constant along the tube because reaction (1) quickly regenerates NO from NO 2 , and the light intensity directly measures the concentration of atomic oxygen. The method is applied to give information on the rates of the reactions O + NO + M → NO 2 + M , O + O 2 + M → O 3 + M , O + SO 2 + M → SO 3 + M , etc. Some results are also presented for the effect on the disappearance of O of the following added gases: N 2 , A, CO 2 , H 2 , CO, N 2 O, C 6 H 8 , SO 3 , Fe(CO) 5 , H 2 O, O 3 , C 2 H 4 , Cl 2 and Br 2 . The rapid catalytic recombination of O by added Cl 2 is discussed in some detail.

scholarly journals Oxygen atom determination in the upper atmosphere by chemiluminescence of nitric oxide

1965 ◽  
Vol 70 (5) ◽  
pp. 1155-1173 ◽  
Author(s):  
Dan Golomb ◽  
N. W. Rosenberg ◽  
Carol Aharonian ◽  
J. A. F. Hill ◽  
H. L. Alden
Keyword(s):  
Nitric Oxide ◽  
Oxygen Atom ◽  
Upper Atmosphere

scholarly journals A Review on Recent Progress of Glycan-Based Surfactant Micelles as Nanoreactor Systems for Chemical Synthesis Applications

2021 ◽  
Vol 2 (1) ◽  
pp. 168-186
Author(s):  
Bahareh Vafakish ◽  
Lee D. Wilson
Keyword(s):  
Chemical Synthesis ◽  
Chemical Reactions ◽  
Recent Progress ◽  
Chemical Species ◽  
Reaction Rates ◽  
Bulk Solution ◽  
Surfactant Micelles ◽  
Conventional Surfactant ◽  
Recent Developments ◽  
To Receive

The nanoreactor concept and its application as a modality to carry out chemical reactions in confined and compartmentalized structures continues to receive increasing attention. Micelle-based nanoreactors derived from various classes of surfactant demonstrate outstanding potential for chemical synthesis. Polysaccharide (glycan-based) surfactants are an emerging class of biodegradable, non-toxic, and sustainable alternatives over conventional surfactant systems. The unique structure of glycan-based surfactants and their micellar structures provide a nanoenvironment that differs from that of the bulk solution, and supported by chemical reactions with uniquely different reaction rates and mechanisms. In this review, the aggregation of glycan-based surfactants to afford micelles and their utility for the synthesis of selected classes of reactions by the nanoreactor technique is discussed. Glycan-based surfactants are ecofriendly and promising surfactants over conventional synthetic analogues. This contribution aims to highlight recent developments in the field of glycan-based surfactants that are relevant to nanoreactors, along with future opportunities for research. In turn, coverage of research for glycan-based surfactants in nanoreactor assemblies with tailored volume and functionality is anticipated to motivate advanced research for the synthesis of diverse chemical species.

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