scholarly journals Periodic System of Isotopes

2021 ◽  
pp. 1-46
Author(s):  
Magula AS ◽  
Keyword(s):  
Periodic Structure ◽  
Cross Sections ◽  
Periodic System ◽  
Chemical Elements ◽  
Radioactive Isotopes ◽  
Periodic Change ◽  
Magic Numbers ◽  
Ore Formation ◽  
Particle Yield ◽  
Isotope System

With the help of a special algorithm being the principle of multilevel periodicity, the periodic change of properties at the nuclear level of chemical elements was discovered and the variant for the periodic system of isotopes was presented. The periodic change in the properties of isotopes, as well as the vertical symmetry of subgroups, was checked for consistency in accordance with the following ten types of the experimental data: mass ratio of fission fragments; quadrupole moment values; magnetic moment; lifetime of radioactive isotopes; neutron scattering; thermal neutron radiative capture cross-sections (n, γ); α-particle yield cross-sections (n, α); isotope abundance on Earth, in the Solar system and other stellar systems; features of ore formation and stellar evolution. For all the ten cases, the correspondences for the proposed periodic structure of the nucleus were obtained. The system was formed in the usual 2D table, similar to the periodic system of elements, and the mass series of isotopes was divided into 8 periods and 4 types of “nuclear” orbitals: sn, dn, pn, fn. The origin of "magic" numbers as a set of filled charge shells of the nucleus was explained. Due to the isotope system, the periodic structure is shown at a new level of the universe and the prospects of its practical use are opened up

scholarly journals Neutron capture data for unstable nuclei – Astrophysical quests and experimental challenges

2019 ◽  
Vol 23 ◽  
pp. 1
Author(s):  
F. Käppeler
Keyword(s):  
Cross Sections ◽  
Reaction Path ◽  
Chemical Elements ◽  
Neutron Sources ◽  
Unstable Nuclei ◽  
Quantitative Studies ◽  
Branching Points ◽  
Supernova Explosions ◽  
R Process ◽  
Pulsed Neutron

The abundances of the chemical elements heavier than iron can be attributed in about equal parts to the r and s processes, which are taking place in supernova explosions and during the He and C burning phases of stellar evolution, respectively. So far, quantitative studies of the r-process are out of reach, because it involves reactions on extremely short-lived neutron-rich nuclei. On the contrary, the situation for the s-process is far advanced, thanks to a comprehensive database of experimental (n,γ) cross sections for most isotopes along the reaction path from 12C to the Pb/Bi region. For the stable isotopes last gaps in the data are presently closed, but further studies are clearly needed to reach the required accuracy and to resolve remaining discrepancies. The quest for cross sections of unstable isotopes remains a persisting challenge though. In particular, nuclei which act as branching points are of prime interest, because they provide key information on the deep stellar interior. While the activation method is limited to a few exceptional branch-point nuclei, successful measurements via the time-of- flight technique are depending on intense pulsed neutron sources and elaborate methods for sample production. Current developments in Europe are providing promising perspectives in both areas.

150 Years of the Periodic System of Chemical Elements

CHEMKON ◽  
2019 ◽  
Vol 26 (7) ◽  
pp. 277-285
Author(s):  
Gisela Boeck
Keyword(s):  
Periodic System ◽  
Chemical Elements

The Periodic System of the Chemical Elements: The Search for Its Discoverer

Isis ◽  
1971 ◽  
Vol 62 (3) ◽  
pp. 314-327 ◽  
Author(s):  
Heinz Cassebaum ◽  
George B. Kauffman
Keyword(s):  
Periodic System ◽  
Chemical Elements

Analysis of the hair coat of domestic cats with special focus on histological structure

2017 ◽  
Vol 13 (1) ◽  
pp. 47-58
Author(s):  
Anna Wyrostek ◽  
Katarzyna Roman ◽  
Katarzyna Czyż ◽  
Marzena Janczak ◽  
Bożena Patkowska-Sokoła
Keyword(s):  
Cross Sections ◽  
Chemical Elements ◽  
Coat Colour ◽  
Histological Structure ◽  
Special Focus ◽  
Domestic Cats ◽  
Hair Coat ◽  
Research Material ◽  
Hair Type ◽  
Axis Length

The aim of the study was to characterize the hair coat of domestic cats. The research material consisted of hairs of different fractions collected in winter from female cats with a uniform hair coat colour: white,cream, red, brown and black. The hairs were divided into individual fractions, i.e. underhair, bristle hair and guard hair, and the following characteristics were evaluated: thickness, length, long and short axis length, stress at break and elongation. SEM (scanning electron microscope) images of all types of hair were taken and used to characterize each hair type and to calculate the number of scales per mm of hair length. The content of ions of various chemical elements was determined as well. Underhairs, which accounted for the largest percentage in the coat, were the thinnest and shortest, and had the most regular and distinct scale pattern. Guard hairs were the least numerous, but were the longest and thickest of all hairs examined. Both guard and bristle hairs had irregular scales with jagged edges. The cross-sections of these hairs revealed the presence of all the layers, i.e. the cuticle, cortex and medulla. In the underhair fraction the medulla was observed only in red cats. In all hairs the share of carbon, oxygen and sulphur ions was largest; these are the main omponents of hair protein, i.e. keratin.

scholarly journals Nuclear Physics of the s Process

2008 ◽  
Vol 25 (1) ◽  
pp. 18-29 ◽  
Author(s):  
I. Dillmann ◽  
C. Domingo Pardo ◽  
F. Käppeler ◽  
A. Mengoni ◽  
K. Sonnabend
Keyword(s):  
Cross Sections ◽  
Nuclear Physics ◽  
State Of The Art ◽  
Decay Rates ◽  
Radioactive Isotopes ◽  
Complementary Information ◽  
The Status ◽  
Direct Input ◽  
New Facilities ◽  
Capture Cross Sections

AbstractStarting from a sketch of the s-process concept formulated 50 years ago, the nuclear physics data for s-process calculations are briefly reviewed with emphasis on the status of neutron capture cross sections and beta decay rates. Accurate and comprehensive experimental data are mandatory as direct input for s-process calculations as well as for improving the complementary information from nuclear theory. The current challenges of the field are discussed in the light of new or optimized methods and state-of-the-art facilities, indicating the potential for accurate measurements and the possibility to study cross sections of radioactive isotopes. These opportunities will be considerably enriched by the enormous improvements provided by new facilities.

scholarly journals The periodic system of chemical elements solid model in the geological aspect

2020 ◽  
pp. 36-47
Author(s):  
Mikhail M. Labushev ◽  
◽  
Timofey M. Labushev ◽  
Keyword(s):  
Crystal Lattice ◽  
Periodic System ◽  
Chemical Element ◽  
Chemical Elements ◽  
Zero Element ◽  
Earth’S Crust ◽  
Solid Model ◽  
Simple Substance ◽  
Volcanic Processes ◽  
Earth's Crust

The topicality of the research comes from the need to obtain new knowledge about the manifestation of the periodic law in nature. Research aim is to associate the periodic system of chemical elements with the chemical composition and structure of natural objects. The research method suggests the creation of a solid model of the periodic system of chemical elements along with its comparison with ore formation objects as well as the manifestation of chemical elements isomorphism and some natural processes geochemistry. Research results. The solid version of the periodic table of the first 95 chemical elements together with a conventional zero element is proposed. Each volume cell characterizes a chemical element with an elementary crystal lattice of simple substance. Similar models can be composed of minerals and rocks associating with material substance of the earth's crust. 16 vertical groups in the model are arranged in a snake-like pattern. The model of the earth's crust with the “cubes” of chemical elements, minerals and mineral associations is proposed. The elements of adjacent spatial groups are naturally concentrated in combination, showing isomorphism while minerals enter the crystal lattice. The relative position of adjacent “cubes” follows the rule of translation in mutually perpendicular directions. The chemical elements of the first group can correspond spatially to volcanoes as well as mud volcanoes. The place of the zero chemical element is considered to be occupied by the elements of adjacent spatial groups. It is assumed that the faces of the “cube” of chemical elements are permeable areas through which chemical elements can be transferred. Summary. The confirmation of the model follows while considering ore formations, isomorphism of chemical elements in minerals and geochemistry of volcanic processes. 46 "Izvestiya vysshikh uchebnykh zavedenii. Gornyi zhurnal". No. 1. 2020 ISSN 0536-1028 Key words: chemical elements; solid model of periodic system; ore formations; isomorphism in crystals; geochemistry of volcanic processes.

scholarly journals Analogies of Genetic and Chemical Code

2017 ◽  
Author(s):  
Miloje M. Rakocevic
Keyword(s):  
Genetic Code ◽  
Periodic System ◽  
Chemical Elements ◽  
Original Manuscript ◽  
Code Table ◽  
Chemical Code

Starting from the previously established hypothesis on the existence of the coherence of the chemical and genetic code, new facts and new insights on the existence of essential analogies between the genetic and chemical code are presented, whereby the chemical code is derived from the original Mendeleev work on the periodic system of chemical elements. When, namely, all elements are scheduled into adequate groups of Periodic system of chemical elements, in accordance to Mendeleev original manuscript tables, then are revealed some very specific mathematical and chemical regularities; among others, Periodic system appears to be a code – the chemical code – in an entity analogy with the terrestrial genetic code. These regularities correspond to the mathematical regularities within the genetic code. Between others relations, it appears also a correspondence between the distribution of codons in the Genetic Code Table and the distribution of chemical elements in the Periodic system with respect to their even/odd parity and stability/instability of the isotopes.

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