Determination of Nuclear Reaction Mechanisms From Energy Spectra of Emitted Particles

1959 ◽  
Vol 114 (4) ◽  
pp. 1143-1145 ◽  
Author(s):  
Bernard L. Cohen ◽  
Allen G. Rubin
Author(s):  
John Ross ◽  
Igor Schreiber ◽  
Marcel O. Vlad

In a chemical system with many chemical species several questions can be asked: what species react with other species: in what temporal order: and with what results? These questions have been asked for over one hundred years about simple and complex chemical systems, and the answers constitute the macroscopic reaction mechanism. In Determination of Complex Reaction Mechanisms authors John Ross, Igor Schreiber, and Marcel Vlad present several systematic approaches for obtaining information on the causal connectivity of chemical species, on correlations of chemical species, on the reaction pathway, and on the reaction mechanism. Basic pulse theory is demonstrated and tested in an experiment on glycolysis. In a second approach, measurements on time series of concentrations are used to construct correlation functions and a theory is developed which shows that from these functions information may be inferred on the reaction pathway, the reaction mechanism, and the centers of control in that mechanism. A third approach is based on application of genetic algorithm methods to the study of the evolutionary development of a reaction mechanism, to the attainment given goals in a mechanism, and to the determination of a reaction mechanism and rate coefficients by comparison with experiment. Responses of non-linear systems to pulses or other perturbations are analyzed, and mechanisms of oscillatory reactions are presented in detail. The concluding chapters give an introduction to bioinformatics and statistical methods for determining reaction mechanisms.


Author(s):  
Matteo Pietraccini ◽  
Eloise Delon ◽  
Audrey Santandrea ◽  
Stéphanie Pacault ◽  
Pierre-Alexandre Glaude ◽  
...  

Author(s):  
Paula Rangel Pestana Allegro ◽  
Márcia de Almeida Rizzutto ◽  
Nemitala Added ◽  
Vitor Ângelo Paulino de Aguiar ◽  
Dennis Lozano Toufen ◽  
...  

This study presents an alternative method to determine isotope ratios using a medium energy accelerator and simultaneously measuring the charged particles and gamma-rays produced in a nuclear reaction.


1983 ◽  
Vol 13 (4) ◽  
pp. 855-872 ◽  
Author(s):  
A F Cattell ◽  
A R Long ◽  
A C Hanna ◽  
A M MacLeod

Author(s):  
F.J. Ager ◽  
S. Elmrabet ◽  
A. Paúl ◽  
Á. Cea-Naharro ◽  
M.D. Ynsa ◽  
...  
Keyword(s):  

Author(s):  
John Ross ◽  
Igor Schreiber ◽  
Marcel O. Vlad

The topic of this chapter may seem like a digression from methods and approaches to reaction mechanisms, but it is not; it is an introduction to it. We worked on both topics for some time and there is a basic connection. Think of an electronic device and ask: how are the logic functions of this device determined? Electronic inputs (voltages and currents) are applied and outputs are measured. A truth table is constructed and from this table the logic functions of the device, and at times some of its components, may be inferred. The device is not subjected to the approach toward a chemical mechanism described in the previous chapter, of taking the device apart and testing its simplest components. (That may have to be done sometimes but is to be avoided if possible.) Can such an approach be applicable to chemical systems? We show this to be the case by discussing the implementation of logic and computational devices, both sequential machines such as a universal Turing machine (hand computers, laptops) and parallel machines, by means of macroscopic kinetics; by giving a brief comparison with neural networks; by showing the presence of such devices in chemical and biochemical reaction systems; and by presenting some confirming experiments. The next step is clear: if macroscopic chemical kinetics can carry out these electronic functions, then there are likely to be new approaches possible for the determination of complex reaction mechanisms, analogs of such determinations for electronic components. The discussion in the remainder of this chapter is devoted to illustrations of these topics; it can be skipped, except the last paragraph, without loss of continuity with chapter 5 and beyond. A neuron is either on or off depending on the signals it has received. A chemical neuron is a similar device.


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