scholarly journals Radioactive Decay as A Second-Order Kinetics Transformation Process. Consequences on Radiometric Dating

2019 ◽  
Vol 12 (1) ◽  
pp. 26
Author(s):  
Giancarlo Cavazzini
Keyword(s):  
Radioactive Decay ◽  
Transformation Process ◽  
Second Order ◽  
Radiometric Dating ◽  
Recent Analysis ◽  
Radioactive Nuclide ◽  
Geological Samples ◽  
Atomic Systems ◽  
Radioactive Nuclides ◽  
Rate Of Decay

Arguments suggest and recent analysis of experimental work confirm that the current interpretation of the transformation process we call ‘radioactive decay’ should be revised. The characteristics of this process are better accounted for by re-interpreting it in terms of second-order kinetics. Therefore, the atomic systems of nuclides we observe decay are ‘radio-activated’, and not, as hitherto believed, ‘radio-active’. According to this interpretation, the rate of decay of a radioactive nuclide is at any instant proportional to the concentration of the physical species that determines its activation. The analysis of λ of alfa- and beta-emitting nuclides show the dependence of these parameters from solar activity and distance. Therefore, if changes in the emission of energy from the sun occurred over time since the formation of a geological system, changes in the values of λ of the radioactive nuclides would also have occurred, and the calculated radiometric age of the system may differ from the true age. Implications on the science of dating geological samples using parent-daughter decay systematics are investigated.

Towards a Technique for Nonlinear Modal Analysis

2012 ◽  
Author(s):  
Simon A. Neild ◽  
Andrea Cammarano ◽  
David J. Wagg
Keyword(s):  
Normal Form ◽  
Modal Analysis ◽  
Equations Of Motion ◽  
Transformation Process ◽  
Second Order ◽  
Identity Transformation ◽  
Modal Testing ◽  
System Response ◽  
Weakly Nonlinear ◽  
Nonlinear Modal Analysis

In this paper we discuss a theoretical technique for decomposing multi-degree-of-freedom weakly nonlinear systems into a simpler form — an approach which has parallels with the well know method for linear modal analysis. The key outcome is that the system resonances, both linear and nonlinear are revealed by the transformation process. For each resonance, parameters can be obtained which characterise the backbone curves, and higher harmonic components of the response. The underlying mathematical technique is based on a near identity normal form transformation. This is an established technique for analysing weakly nonlinear vibrating systems, but in this approach we use a variation of the method for systems of equations written in second-order form. This is a much more natural approach for structural dynamics where the governing equations of motion are written in this form as standard practice. In fact the first step in the method is to carry out a linear modal transformation using linear modes as would typically done for a linear system. The near identity transform is then applied as a second step in the process and one which identifies the nonlinear resonances in the system being considered. For an example system with cubic nonlinearities, we show how the resulting transformed equations can be used to obtain a time independent representation of the system response. We will discuss how the analysis can be carried out with applied forcing, and how the approximations about response frequencies, made during the near-identity transformation, affect the accuracy of the technique. In fact we show that the second-order normal form approach can actually improve the predictions of sub- and super-harmonic responses. Finally we comment on how this theoretical technique could be used as part of a modal testing approach in future work.

Second-order relativistic corrections for the S(L=0) states in one- and two-electron atomic systems

2005 ◽  
Vol 83 (1) ◽  
pp. 1-21
Author(s):  
Alexei M Frolov ◽  
Catalin C Mitelut ◽  
Zheng Zhong
Keyword(s):  
Second Order ◽  
Electron Systems ◽  
Specific Interest ◽  
Atomic Systems ◽  
Expectation Value ◽  
Relativistic Corrections ◽  
Alternative Approach ◽  
Compensation Technique ◽  
Three Body ◽  
Regular Operators

An analytical approach is developed to compute the first- (~α2) and second-order (~α4) relativistic corrections in one- and two-electron atomic systems. The approach is based on the reduction of all operators to divergent (singular) and nondivergent (regular) parts. Then, we show that all the divergent parts from the differentmatrix elements cancel each other. The remaining expression contains only regular operators and its expectation value can be easily computed. Analysis of the S(L = 0) states in such systems is of specific interest since the corresponding operators for these states contain a large number of singularities. For one-electron systems the computed relativistic corrections coincide exactly with the appropriate result that follows from the Taylor expansion of the relativistic (i.e., Dirac) energy. We also discuss an alternative approach that allows one to cancel all singularities by using the so-called operator-compensation technique. This second approach is found to be very effective in applications of more complex systems, such as helium-like atoms and ions, H+2-like ions, and some exotic three-body systems.

The Von Neumann-Mullins Theory of Grain Growth – Valid or Not?!

2004 ◽  
Vol 467-470 ◽  
pp. 1111-1116 ◽  
Author(s):  
Lasar S. Shvindlerman ◽  
Günter Gottstein ◽  
Anthony D. Rollett
Keyword(s):  
Relative Rate ◽  
Second Order ◽  
Rate Of Change ◽  
Recent Analysis ◽  
Order Problem ◽  
Von Neumann ◽  
First Order ◽  
Dimensional Network ◽  
The Stability ◽  
Grain Topology

We present a new analysis of the relative rate of growth or shrinkage of grains in a two-dimensional network, based on the classical Von Neumann-Mullins (VN-M) analysis. We find that an analysis of the stability of the grain shape during shrinkage or growth shows that any change in the regular 2D grain leads to changes in the shape. We also re-examine a recent analysis that claims to have invalidated the VN-M relationship, but find that it is still valid, and that the cited analysis, in fact, confused a second order correction with a first order problem, partly because their derivation was in error. The erroneous magnitude of the discrepancy led them to use unphysical issues to explain the discrepancy. The way in which the curvature is distributed along the perimeter of a grain only gives rise only to second order corrections to the rate of change of area as a function of grain topology (number of sides).

Computation of Second-Order Many-Body Corrections in Relativistic Atomic Systems

1986 ◽  
Vol 57 (9) ◽  
pp. 1126-1129 ◽  
Author(s):  
W. R. Johnson ◽  
J. Sapirstein
Keyword(s):  
Second Order ◽  
Many Body ◽  
Atomic Systems

Determination Radon Concentration (Radon Gas) in Urine of Patients with Cancer

2021 ◽  
Vol 19 (4) ◽  
pp. 87-91
Author(s):  
Mohammed M. Asker ◽  
Esam S. Ali ◽  
Sarwa A. Mohammed
Keyword(s):  
Radon Concentration ◽  
Radioactive Isotope ◽  
Radioactive Decay ◽  
Track Detector ◽  
Alpha Particles ◽  
Radioactive Nuclide ◽  
Alpha Radiation ◽  
Patients With Cancer ◽  
Radon Gas ◽  
Irradiation Process

The present study aims at studying the measurement radon concentration (Radon gas) in the urine of patients with cancer, that made up of (23) different samples of patients’ urine. These samples have collected from Kirkuk Oncology & Hematology Center. Chemical etching process for CR-39 track detector has used to record the traces of Alpha particles “alpha rays” or “alpha radiation” that comes from Radon included in the models. The Plastic Tubing – Tubes that contain some models in reagent irradiation process, which shaped as U letter, have been used. The results illustrated that the highest concentration of Radon is (8.9) Bq.m-1 in R14 model, as well as the lowest concentration of Radon is (1.5) Bq.m-1 in R4 model. The Radon levels that have been measured are within the natural limits of radioactive decay caused by radioactive nuclide or “radioactive isotope” in urine of patients with cancer; these are not a risk in humanity.

Writing Neolithic Britain: an interpretive journey

2018 ◽  
Author(s):  
Keith Ray ◽  
Julian Thomas
Keyword(s):  
Roman Empire ◽  
Cultural Change ◽  
Radioactive Isotopes ◽  
Radiometric Dating ◽  
Neolithic Period ◽  
Major Work ◽  
Past Half Century ◽  
Rate Of Decay ◽  
Dating Method ◽  
Neolithic Cultures

It is just over sixty years since Stuart Piggott published his major work, Neolithic Cultures of the British Isles. This was the first comprehensive account of what was then known and assumed about the ‘New Stone Age’ in these islands, and it surveyed discoveries and summarized debates that had occurred over the previous century. This process of gradual accumulation of data and ideas has continued apace since Piggott was writing, not least owing to the precision with which we can now date much of the activity that characterizes the Neolithic. When Piggott was writing his book in the early 1950s an American, Willard Libby, was experimenting with the technique of radiocarbon dating as a by-product of the development of nuclear technology. This dating method uses the rate of decay of radioactive isotopes to measure the time that has elapsed since a sample of organic matter last exchanged carbon with its environment—in short, the time since an organism died. Application of the method has cumulatively transformed our understanding of prehistoric chronology. To illustrate the impact upon the study of Neolithic Britain, we have only to appreciate that in Neolithic Cultures Piggott imagined a British Neolithic period that lasted for around five hundred years, beginning in about 2000BCE. This estimated span was based on a series of assumptions about the rate of cultural change, and the affinities between artefacts in Britain, continental Europe, and further afield. However, over the past half-century this inherited chronology has been swept away as radiometric dating has gradually been refined, and huge numbers of dated samples have accumulated. These now suggest that the Neolithic period began in Britain shortly before 4000 BCE, and ‘ended’ with the advent of a variety of objects made of metal instead of stone, from around 2400 BCE. The implications of this transformed appreciation of the duration of the Neolithic are profound, for while Piggott and his contemporaries were dealing with periods of historical time that were comparable with those with which we are familiar from recorded history (the rise and fall of the Roman Empire, the emergence and spread of Islam, the development of capitalism), we now have evidence for human activity in the Neolithic of Britain that is dispersed across an expanse of time as much as three times longer than these major historical episodes.

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