scholarly journals A New Approach for Calculating the Alpha-Decay Half-Life for the Heavy and Super-heavy Elements and an Exact A Priori Result for Beyllium-8

2021 ◽  
Author(s):  
Wayne Surdoval ◽  
David Berry
Keyword(s):  
Half Life ◽  
A Priori ◽  
Alpha Decay ◽  
Heavy Elements ◽  
New Approach

Calculation of Q-value and half-life of alpha decay in super heavy elements using S-matrix theory

2020 ◽  
Vol 29 (07) ◽  
pp. 2050043
Author(s):  
R. Rahul ◽  
B. Nandana ◽  
S. Mahadevan
Keyword(s):  
Half Life ◽  
Matrix Theory ◽  
Scattering Problem ◽  
Alpha Decay ◽  
Heavy Elements ◽  
Nuclear Potential ◽  
Q Value ◽  
S Matrix ◽  
Double Folding ◽  
Heaviest Elements

The half-life and the [Formula: see text]-value of alpha decay in several super heavy elements are calculated. The nuclear potential is computed using the double-folding method. Using the S-matrix theory, the alpha decay is treated as a scattering problem between alpha particle and the daughter nucleus. Nuclear potential was approximated by the parameterized Woods–Saxon potential. This idea has also been extended to predict the half-life and the [Formula: see text]-value of the heaviest elements of few other alpha chains.

Mathematical Knowledge and the Interplay of Practices

2015 ◽  
Author(s):  
José Ferreirós
Keyword(s):  
Mathematical Knowledge ◽  
A Priori ◽  
Philosophy Of Mathematics ◽  
Advanced Mathematics ◽  
New Approach ◽  
Agent Based ◽  
Epistemology Of Mathematics ◽  
Actual Experience ◽  
Elementary Math ◽  
Mathematical Tradition

This book presents a new approach to the epistemology of mathematics by viewing mathematics as a human activity whose knowledge is intimately linked with practice. Charting an exciting new direction in the philosophy of mathematics, the book uses the crucial idea of a continuum to provide an account of the development of mathematical knowledge that reflects the actual experience of doing math and makes sense of the perceived objectivity of mathematical results. Describing a historically oriented, agent-based philosophy of mathematics, the book shows how the mathematical tradition evolved from Euclidean geometry to the real numbers and set-theoretic structures. It argues for the need to take into account a whole web of mathematical and other practices that are learned and linked by agents, and whose interplay acts as a constraint. It demonstrates how advanced mathematics, far from being a priori, is based on hypotheses, in contrast to elementary math, which has strong cognitive and practical roots and therefore enjoys certainty. Offering a wealth of philosophical and historical insights, the book challenges us to rethink some of our most basic assumptions about mathematics, its objectivity, and its relationship to culture and science.

Survey Data Quality in Analyzing Harmonized Indicators of Protest Behavior: A Survey Data Recycling Approach

2021 ◽  
pp. 000276422110216
Author(s):  
Kazimierz M. Slomczynski ◽  
Irina Tomescu-Dubrow ◽  
Ilona Wysmulek
Keyword(s):  
Data Processing ◽  
Data Quality ◽  
Survey Data ◽  
A Priori ◽  
Data Sets ◽  
New Approach ◽  
Survey Quality ◽  
Survey Error ◽  
Ex Post ◽  
The Impact

This article proposes a new approach to analyze protest participation measured in surveys of uneven quality. Because single international survey projects cover only a fraction of the world’s nations in specific periods, researchers increasingly turn to ex-post harmonization of different survey data sets not a priori designed as comparable. However, very few scholars systematically examine the impact of the survey data quality on substantive results. We argue that the variation in source data, especially deviations from standards of survey documentation, data processing, and computer files—proposed by methodologists of Total Survey Error, Survey Quality Monitoring, and Fitness for Intended Use—is important for analyzing protest behavior. In particular, we apply the Survey Data Recycling framework to investigate the extent to which indicators of attending demonstrations and signing petitions in 1,184 national survey projects are associated with measures of data quality, controlling for variability in the questionnaire items. We demonstrate that the null hypothesis of no impact of measures of survey quality on indicators of protest participation must be rejected. Measures of survey documentation, data processing, and computer records, taken together, explain over 5% of the intersurvey variance in the proportions of the populations attending demonstrations or signing petitions.

scholarly journals On the security of $\alpha\eta$: response to 'some attacks on quantum-based cryptographic protocols'

2006 ◽  
Vol 6 (7) ◽  
pp. 561-582
Author(s):  
H.P. Yuen ◽  
R. Nair ◽  
E. Corndorf ◽  
G.S. Kanter ◽  
P. Kumar
Keyword(s):  
Coherent State ◽  
Optical Communications ◽  
A Priori ◽  
Key Generation ◽  
Generation System ◽  
New Approach ◽  
Security Proof ◽  
Grover Search ◽  
Channel Loss ◽  
Key Length

Lo and Ko have developed some attacks on the cryptosystem called $\alpha \eta$}, claiming that these attacks undermine the security of $\alpha\eta$ for both direct encryption and key generation. In this paper, we show that their arguments fail in many different ways. In particular, the first attack in [1] requires channel loss or length of known-plaintext that is exponential in the key length and is unrealistic even for moderate key lengths. The second attack is a Grover search attack based on `asymptotic orthogonality' and was not analyzed quantitatively in [1]. We explain why it is not logically possible to "pull back'' an argument valid only at $n=\infty$ into a limit statement, let alone one valid for a finite number of transmissions n. We illustrate this by a `proof' using a similar asymptotic orthogonality argument that coherent-state BB84 is insecure for any value of loss. Even if a limit statement is true, this attack is a priori irrelevant as it requires an indefinitely large amount of known-plaintext, resources and processing. We also explain why the attacks in [1] on $\alpha\eta$ as a key-generation system are based on misinterpretations of [2]. Some misunderstandings in [1] regarding certain issues in cryptography and optical communications are also pointed out. Short of providing a security proof for $\alpha\eta$, we provide a description of relevant results in standard cryptography and in the design of $\alpha\eta$ to put the above issues in the proper framework and to elucidate some security features of this new approach to quantum cryptography.

New Trends of Image Analysis in the Medical Field

1988 ◽  
Vol 27 (02) ◽  
pp. 53-57 ◽  
Author(s):  
J. Dengler ◽  
H. Bertsch ◽  
J. F. Desaga ◽  
M. Schmidt
Keyword(s):  
Image Processing ◽  
Cancer Research ◽  
Image Analysis ◽  
A Priori ◽  
Research Work ◽  
A Priori Knowledge ◽  
German Cancer Research ◽  
Medical Field ◽  
New Approach ◽  
Biological Field

SummaryImage analysis with the aid of the computer has rapidly developed over the last few years. There are many possibilities of making use of this development in the medical and biological field. This paper is meant to give a rather general overview of recent systematics regarding the existing methodology in image analysis. Furthermore, some parts of these systematics are illustrated in greater detail by recent research work in the German Cancer Research Center. In particular, two applications are reported where special emphasis is laid on mathematical morphology. This relatively new approach to image analysis finds growing interest in the image processing community and has its strength in bridging the gap between a priori knowledge and image analysis procedures.

Study of the dependence of alpha decay half-life on the surface symmetry energy

2020 ◽  
Vol 29 (09) ◽  
pp. 2050070
Author(s):  
S. Nejati ◽  
O. N. Ghodsi
Keyword(s):  
Symmetry Energy ◽  
Half Life ◽  
Surface Region ◽  
Alpha Decay ◽  
Proton Density ◽  
Skin Thickness ◽  
Neutron Skin ◽  
Mother And Daughter ◽  
Energy Coefficient ◽  
Finite Nuclei

In this study, the effect of the surface symmetry energy on the neutron skin thickness and division of it into the bulk and surface parts are investigated by determination of the symmetry energy coefficient [Formula: see text] of finite nuclei. We demonstrate the importance of the isospin asymmetry distribution in the symmetry energy coefficient of finite nuclei at the surface region. We attempt to find out how different surface symmetry energies may affect alpha decay half-life. The Skyrme interactions are used to describe the neutron and proton density distributions and to calculate the symmetry energy coefficient [Formula: see text] of four nuclei and the surface symmetry energy. The chosen Skyrme interactions can produce the binding energy and root-mean-square charge radii of both mother and daughter nuclei. We single out the spherical isotones of [Formula: see text] named [Formula: see text]Pb, [Formula: see text]Po, [Formula: see text]Rn and [Formula: see text]Ra for daughter nuclei and explore the dependence of the bulk and surface contributions on the surface symmetry energy. The half-life of mother nuclei, i.e., [Formula: see text]Po, [Formula: see text]Rn, [Formula: see text]Ra and [Formula: see text]Th, is employed to investigate the extent to which it is affected by different surface symmetry energies. The calculated half-lives show a downward tendency for different surface symmetry energies which can be caused by various neutron skin thicknesses.

Theoretical studies on Alpha decay half-lives of Astatine isotopes

2020 ◽  
Vol 29 (02) ◽  
pp. 2050008 ◽  
Author(s):  
S. S. Hosseini ◽  
H. Hassanabadi ◽  
Dashty T. Akrawy ◽  
Ali H. Ahmed
Keyword(s):  
Half Life ◽  
Magic Number ◽  
Alpha Decay ◽  
Parent Nucleus ◽  
Hindrance Factor ◽  
Theoretical Formula ◽  
Proximity Potential ◽  
Alpha Emission ◽  
Closed Shells ◽  
Penetration Probability

The half-life of a parent nucleus of Astatine isotopes [Formula: see text] decaying via alpha emission is investigated by employing Coulomb and proximity potential model (CPPM) using the WKB barrier penetration probability and other different analytical and semiempirical formulae of Royer, AKRE, Akrawy, RoyerB, MRoyerB, MRenB, SemFIS, VS and SLB. In the calculation of Alpha decay (AD) half-life the available experimental and theoretical [Formula: see text]-values with the total alpha kinetic energy have been considered. The behavior of hindrance factor with the variation of mass numbers of parent nuclei for isotopes in the range [Formula: see text] and the effect of magic number at closed shells were investigated. Through the comparison of obtained results from the systematics with the experimental data, the prediction of SemFIS formula was the best among the studied ones where it shows the minimum standard deviation of 0.829881.

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