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The number seven is, since ancient Eastern cultures, the one that most clearly expresses philosophical, religious, astrological and Kabbalistic symbolism. It is considered the symbol of value and balance. This paper aims to reconstruct the vicissitudes of the phraseology underlying the number seven in Italian and its dialects [ABSTRACT FROM AUTHOR]

The Cubic plus Yukawa plus Exponential (CYE) model has been used to study the different decay properties of Superheavy nuclei 298,310114, 306,318122, 308,310124, 310,322126 and compared them with the available theoretical and experimental values. Here, the half-lives of several clusters have been computed that have not yet been detected experimentally. Hopefully, this will assist future research in this area. As a result of comparing the three different decay modes (α-decay, cluster radioactivity and spontaneous fission), it was possible to predict the predominant decay modes of Superheavy nuclei. [ABSTRACT FROM AUTHOR]

We investigate the state complexity of languages resulting from the cascade product of two minimal deterministic finite automata with  n and  m states, respectively. More precisely we study the magic number problem of the cascade product operation and show what range of complexities can be produced in case the left automaton is unary, that is, has only a singleton letter alphabet. Here we distinguish the cases when the involved automata are reset automata, permutation automata, permutation-reset automata, or do not have any restriction on their structure. It turns out that the picture on the obtained state complexities of the cascade product is diverse, and for all cases, except where the left automaton is a unary permutation(-reset) or a deterministic finite automaton without structural restrictions, and the right one is a reset automaton or a deterministic finite automaton without structural restrictions, we are able to identify state sizes that cannot be reached — these numbers are called "magic." [ABSTRACT FROM AUTHOR]

Monolayer-protected noble metal clusters, also called nanoclusters, can be produced with the atomic precision and in large-scale quantity and are playing an increasingly important role in the field of nanoscience. To outline the origin and the perspectives of this new field, we overview the main results obtained on free metal clusters produced in gas phase including mainly electronic properties, the giant atom concept, the optical properties, briefly the role of the metal atom (alkali, divalent, noble metal) and finally the atomic structure of clusters. We also discuss the limitations of the free clusters. Then, we describe the field of monolayer-protected metal clusters, the main results, the new offered perspectives, the added complexity, and the role of the ligand beyond the superatom concept. [ABSTRACT FROM AUTHOR]

We consider an N fermion system at low temperature T in which we encounter special particle number values N m exhibiting special traits. These values arise when focusing attention upon the degree of mixture (DM) of the pertinent quantum states. Given the coupling constant of the Hamiltonian, the DMs stay constant for all N-values but experience sudden jumps at the N m . For a quantum state described by the matrix ρ , its purity is expressed by T r ρ 2 and then the degree of mixture is given by 1 − T r ρ 2 , a quantity that coincides with the entropy S q for q = 2 . Thus, Tsallis entropy of index two faithfully represents the degree of mixing of a state, that is, it measures the extent to which the state departs from maximal purity. Macroscopic manifestations of the degree of mixing can be observed through various physical quantities. Our present study is closely related to properties of many-fermion systems that are usually manipulated at zero temperature. Here, we wish to study the subject at finite temperature. The Gibbs ensemble is appealed to. Some interesting insights are thereby gained. [ABSTRACT FROM AUTHOR]

Applications of configuration-mixing methods for nuclei near the proton and neutron drip lines are discussed. A short review of magic numbers is presented. Prospects for advances in the regions of four new "outposts" are highlighted: 28 O, 42 Si, 60 Ca and 78 Ni. Topics include shell gaps, single-particle properties, islands of inversion, collectivity, neutron decay, neutron halos, two-proton decay, effective charge, and quenching in knockout reactions. [ABSTRACT FROM AUTHOR]

In nuclear theory, there is always a quest for possible extensions of the nuclear landscape and extending our knowledge to the limits of nuclear existence. In this study, we examine the stability and structural properties of a wide range of nuclei in super- and ultra-heavy region in a phenomenological semi-microscopic approach. we calculated the shell correlation energy, residual pairing correction energy, two-nucleon separation energy and two-nucleon energy gap for 3670 even–even nuclei along β -stability line and two-neutron driplines in the ranges 7 0 ≤ Z ≤ 2 7 4 with 8 0 ≤ N ≤ 5 4 8 and 7 0 ≤ Z ≤ 2 1 2 with 1 2 6 ≤ N ≤ 5 4 8 , respectively. To assure reliability and confidence of the new results in the ultra-heavy region, we extended the search space to include heavy and super-heavy nuclei. We report 83 double magic nuclei and address the predominance of proton and neutron magic numbers. Our calculations reproduced known results on nuclear magicity and present strong evidences on islands of stability and magic numbers in super- and ultra-heavy regions. We also address shifts in nuclear magicity along the nuclear landscape close to the β -stability line and close to the neutron rich regions. [ABSTRACT FROM AUTHOR]

Hollow nanostructures are at the forefront of many scientific endeavors. These consist of nanoboxes, nanocages, nanoframes, and nanotubes. We examine the mathematics of atomic coordination in nanoboxes. Such structures consist of a hollow box with n shells and t outer layers. The magical formulas we derive depend on both n and t. We find that nanoboxes with t = 2 or 3, or walls with only a few layers generally have bulk coordinated atoms. The benefits of low-coordination in nanostructures is shown to only occur when the wall thickness is much thinner than normally synthesized. The case where t = 1 is unique, and has distinct magic formulas. Such low-coordinated nanoboxes are of interest for a myriad variety of applications, including batteries, fuel cells, plasmonic, catalytic and biomedical uses. Given these formulas, it is possible to determine the surface dispersion of the nanoboxes. We expect these formulas to be useful in understanding how the atomic coordination varies with n and t within a nanobox. [ABSTRACT FROM AUTHOR]

There has been plenty of empirical evidence which shows that the single-particle picture holds to a good approximation in atomic nuclei. In this picture, protons and neutrons move independently inside a mean-field potential generated by an interaction among the nucleons. This leads to the concept of nuclear shells, similar to the electronic shells in atoms. In particular, the magic numbers due to closures of the nucleonic shells, corresponding to noble gases in elements, have been known to play an important role in nuclear physics. Here we propose a periodic table for atomic nuclei, in which the elements are arranged according to the known nucleonic shells. The nuclear periodic table clearly indicates that nuclei in the vicinity of the magic numbers can be understood in terms of a shell closure with one or two additional nucleons or nucleon holes, while nuclei far from the magic numbers are characterized by nuclear deformation. [ABSTRACT FROM AUTHOR]

The alpha decay chain properties of Z = 122 isotope in the mass range 298? A 350, even-even nuclei, are studied using a fission-like model with an effective combination of the cubic plus proximity potential in the pre and post-scission regions, wherein the decay rates are calculated using improved transfer matrix method, and the results are in good agreement with other phenomenological formulae such as Universal decay law, Viola-Seaborg, Royer, etc. The nuclear ground-state masses are taken from WS4 mass model. The next minimum in the half-life curves of the decay chain obtained at N=186,178 & 164 suggest the shell closure at N=184, 176 & 162 which coincides well with the predictions of two-centre shell model approach. This study also unveils that the isotopes 298-300, 302, 304-306, 308-310, 312,314122 show 7α, 5α, 4α, 3α, 2α and 1α decay chain, respectively. All the other isotopes from A = 316 to 350 may undergo spontaneous fission since the obtained SF half -lives are comparatively less. The predictions in the present study may have an impact in the experimental synthesis and detection of the new isotopes in near future. [ABSTRACT FROM AUTHOR]

A new systematic formula is suggested to evaluate the (n, p) reaction cross sections at neutron energy of 14.5 MeV based upon the reaction's Q-value dependence, explicit symmetry breaking, and shell effects. The measured data for the (n, p) reaction cross sections have been gathered from the available literature, and then, it was analyzed for isotopes having 3 ≤ Z ≤ 83. It has been noted that the plot of σ(n,p) against Z/A3/2, N-Z+1/A4/3 and N/Z·A2/3 is more efficient in determining the (n, p) reaction cross sections, as the reaction Q-value is related to values of σ(n,p) too, which has been adequately represented and compared to other terms such as Sp, Sn, and Sα separation energies. The odd-even effects investigated in the cross sections of odd-mass nuclei are higher than those of their neighboring even-even nuclei close to magic numbers. The estimates of the current formula are compared with the experimental data gathered from the literature, and they are found to be in good agreement. [ABSTRACT FROM AUTHOR]

We formalized the nuclear mass problem in the inverse problem framework. This approach allows us to infer the underlying model parameters from experimental observation, rather than to predict the observations from the model parameters. The inverse problem was formulated for the numerically generalized semi-empirical mass formula of Bethe and von Weizsäcker. It was solved in a step-by-step way based on the AME2012 nuclear database. The established parametrization describes the measured nuclear masses of 2564 isotopes with a maximum deviation less than 2.6MeV, starting from the number of protons and number of neutrons equal to 1. The explicit form of unknown functions in the generalized mass formula was discovered in a step-by-step way using the modified least procedure, that realized in the algorithms which were developed by Lubomir Aleksandrov to solve the nonlinear systems of equations via the Gauss-Newton method, lets us to choose the better one between two functions with same . In the obtained generalized model, the corrections to the binding energy depend on nine proton (2, 8, 14, 20, 28, 50, 82, 108, 124) and ten neutron (2, 8, 14, 20, 28, 50, 82, 124, 152, 202) magic numbers as well on the asymptotic boundaries of their influence. The obtained results were compared with the predictions of other models. [ABSTRACT FROM AUTHOR]

Inspired by the experimental discovery of magic numbers we present a first study using density functional theory for the structure and properties of neutral and cationic Bi6Cu3 and Bi5Cu2 clusters. Our results confirm predictions based on Wade's rules. The closed electron shells, characteristic of cationic clusters help impose enhanced stability, while also complying with Wade's rules. Charge distribution analysis, as well as electrostatic potential maps show that in almost all cases, Bi atoms donate charges to Cu atoms. According to the analysis of condensed Fukui indices, Cu atoms inside both clusters are not reactive. Contrastingly, Bi atoms are reactive and may be targeted by different types of attack. This study of the electronic properties may thus help to determine experimental strategies with the capacity to enhance the synthesis of catalysts. [ABSTRACT FROM AUTHOR]

Isothermal molecular dynamics is used to find the magic numbers corresponding to clusters of fcc transition metals: silver and copper. To that end, we use both our own computer program with a tight-binding potential and well-known LAMMPS software whose standard package is designed to model metal systems by the embedded atom method. Regardless of the choice between two relaxation techniques (lowtemperature relaxation at 1 K and the variant involving a gradual temperature decrease with subsequent relaxation at 1 K), magic number 13 is detected that corresponds to the first term of the Chini series. At the same time, other magic numbers are also found that belong and do not belong to this series. [ABSTRACT FROM AUTHOR]

In the last 35 years, a large amount of data on the changes in the mean-square charge radii, δ〈 r 〉, around the lead region has been gathered. Isotopic chains are often normalised and compared to reduce the impact of systematic uncertainties of the extracted δ〈 r 〉 from the isotope shifts. However, this biased picture can obscure other interesting effects that are apparent in absolute scale. In this contribution, we review the extent of the knowledge on the δ〈 r 〉 in the lead region in addition to observations on the absolute scale. [ABSTRACT FROM AUTHOR]

Nuclear level densities of Pb and Y are calculated using the Lipkin-Nogami (LN) method and Bradeen-Cooper-Schrieffer (BCS) model. It is revealed that the calculated nuclear level densities are highly matched with the experimental data of Oslo group. The excitation energy and entropy are calculated for mentioned nuclei. In the case of two studied nuclei the characteristic of being magic for the number of neutrons or protons causes the decrease of the excitation energy and entropy contribution of magic system at low temperatures. [ABSTRACT FROM AUTHOR]

The system of Kohn-Sham equations is solved self-consistently for the two-dimensional, spatially separated electrons and holes. We find the series of magic numbers for the total angular momentum of the electrons and holes in a strong magnetic field. The change of the angular momentum of the charge carriers is shown to lead to the persistent current oscillations. [ABSTRACT FROM AUTHOR]

Jelliumatic shell model (JSM), a variant of jellium model (JM), is proposed in an attempt to rationalize the electron counts of four metal clusters that 'violate' the global jelliumatic model (GJM): (1) for the spherically shaped [CuH(SCNR)], the global jelliumatic electron ( gje) count of 30 is partitioned into three electronic shells of {[H]@[CuH]@[CuH(SCNR)]} with 2, 8, and 20 jelliumatic shell electrons ( jse); each shell conforms to JM for a spherical shape; (2) for the [CuH{SP(OPr)}] cluster, the gje of 22 can be divided into two electronic shells of {[CuH]@[CuHL]} with jse of 10 and 12, respectively; each shell satisfies JM for a prolate ellipsoidal shape; (3) for the [CuH{SP(OPr)}] cluster, with an overall prolate molecular shape, the gje of 40 can be subdivided into three electronic shells of {[CuH]@[CuH]@[CuHL]} with 16, 12, and 12 jse, in harmony with an oblate ellipsoidal shape for the [CuH] core and prolate ellipsoidal shapes for the [CuH] and [CuHL] shells, respectively; and (4) for the spherical-shaped intermetalloid {[Sn]@[Cu]@[Sn]} and {[As]@[Ni]@[As]} clusters, the gje of 108 can be apportioned into three electronic shells (charges as shown) with 8, 8, and 92 jse with each shell being in compliance with JM for a spherical shape. [ABSTRACT FROM AUTHOR]

Analogous to atoms, superatoms can be used as building blocks to compose molecules and materials. To demonstrate this idea, the possibility of using tetrahedral Ag4 cluster to form a series of superatomic molecules Ag4X4 (X=H, Li, Na, K, Cu, Ag, Au and F, Cl, Br) is discussed. Based on the super valence bond model, a tetrahedral Ag4 cluster can be viewed as a 4-electron superatom, which can mimic a sp3 hybridization C atom. By comparison of the representative superatomic molecules Ag4X4 (X=Au, Cl) with the corresponding simple molecules CX4 (X=H, Cl), the similarities in terms of chemical bonding patterns and molecular orbitals (MOs) are conspicuous. Energy calculations predict that the Ag4 superatom can bind with all the involved ligands. Furthermore, the stabilities of superatomic molecules are enhanced by the large gaps of the highest occupied molecular orbital and the lowest unoccupied molecular orbital (HOMO-LUMO gaps) and high aromaticity. Our studies may find applications in assembling materials with superatoms. [ABSTRACT FROM AUTHOR]

We have studied the structure and stability of the ionic LiXe and neutral LiXe (n = 1-35) small clusters. The potential energy surface of the ionic cluster is described using additive potentials, which represent the pair interactions taken from the best available coupled cluster ab initio calculations. The V and V potentials have been fitted by Tang and Toennies and Lennard-Jones (LJ) forms, respectively. The structure of LiXe neutral clusters have been investigated using a model potential and ab initio calculations. We have used the LiXe potential in its ground state and fitted to the Tang and Toennies formula. The LiXe optimized geometry is, then, used for one electron self consistent filed calculation of the only alkali valence electron interacting with the LiXe cluster. In order to determine the geometry of LiXe and LiXe clusters and their isomers, the potential energy surface has been explored by the Monte Carlo basin Hopping method. Their relative stability was studied by evaluating the energy and the energy differences as function of number n of Xenon atoms in clusters. It was shown, for LiXe, that n = 4, 6, 10, 14, 16, 18, 20, 22, 24, 26, 28 and 30 are the most stable structures. [ABSTRACT FROM AUTHOR]

It is suggested that the Bigioni-Zheng metal cluster, formulated as [Ag(SR)] based on X-ray structure determinations, may be impregnated with a number of hydrogen atoms (in the form of hydrides) to give three series of clusters incorporating (6 + 1) concentric Platonic polyhedral shells and conforming to five magic numbers in succession. [ABSTRACT FROM AUTHOR]

We review the theory behind abundance of experimentally observed nanoclusters produced in beams, aiming to understand their magic number behavior. It is shown how use of statistical physics, with certain assumptions, reduces the calculation of equilibrium abundance to that of partition functions (PFs) of single clusters. Methods to practically calculate these PFs are introduced. The formalism is general and potential independent, but is only applicable to equilibrium or close-to-equilibrium scenarios and the interactions for which the PFs can be accurately calculated. As an illustration, we compute the abundance of Lennard-Jones clusters at low temperatures, which reveals their experimentally observed magic number behavior. This shows that purely energetic and thermodynamic reasons can cause the magic numbers. We then briefly review kinetic approach to the problem and comment on the interplay between chemical, mechanical and thermodynamic stability of the clusters in more generality. [ABSTRACT FROM AUTHOR]

Copyright of Physics Essays is the property of Physics Essays Publication and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Physics Essays is the property of Physics Essays Publication and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

It is suggested that the hollow coinage-metal icosahedral cage of the [Ag(SR)] tetraanion ( 1a) may be occupied by two hydrogen atoms, giving rise to a dihydridic cluster [HAg(SR)] tetraanion ( 2b). As a consequence, two series of clusters, with different electron counts, can be formed by chemical means: the 18-electron series [HAg(SR)] via stepwise protonation of 1a and the 20-electron series [HAg(SR)] via stepwise deprotonation of 2b (here x = 0, 1, 2). Both series are closed-shell Jelliumatic clusters and expected to be stable. The corresponding members of these two series (for a given x value) are related by a two-electron reduction. These pairs raise the possibility of the hollow icosahedral metal cages in housing a number of hydrogen atoms, either via stepwise protonations or by absorption of hydrogen molecules. [ABSTRACT FROM AUTHOR]

In this article, the interdisciplinary science of clusters is discussed in general terms. Different types of clusters across vast scales of matter, energy, space, and time in the physical world are discussed. Specific examples of clusters in chemistry and physics are used to illustrate various principles or models of clustering processes of atoms and molecules as well as to demonstrate the exquisite beauty and pattern of clusters and the clustering phenomena so ubiquitous in nature. Nowadays, 'designer clusters' can be made with tailorable properties and used as 'building blocks' to form supermolecules, or to construct large cluster-based hierarchical materials with tunable properties, or to fabricate cluster-based devices with specific functions, etc., thereby providing a materials base for nanotechnology. Clustering is a spontaneous self-assembly process and the similarity across scales reflects the intrinsic self-organization and self-similarity principle of the physical world. Geometry and symmetry transcend all clustering processes, in ordered as well as in disordered systems. [ABSTRACT FROM AUTHOR]

Within the framework of the shell model, we consider the residual interaction to be a surface delta interaction. This interaction has been applied in the calculation of the energy levels of 210Po, which belong to N = 126 magic closed shell nuclei. The pure and the configuration mixings are applied in the calculations of matrix elements. The predicted energy levels are compared with experimental data. [ABSTRACT FROM AUTHOR]

Copyright of Physics Essays is the property of Physics Essays Publication and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

We investigated the possible formation of mixed B nB′ n′Ca2+ complexes where B and B′ are two different nucleobases. Electrospray ionization (ESI) mass spectrometric experiments from solutions containing two different kinds of nucleobases and calcium ions were carried out to investigate the formation of magic number clusters that may be relevant in a biological point of view. The results presented here clearly show that mixed complexes can be formed and are stable in the gas phase. This represents an important step toward more complex solutions in which several nucleobases are present simultaneously and may compete in the formation of cationized clusters. We believe that thorough investigations on such systems may help understanding biological processes that may effect the tridimensional structure of the DNA macromolecule. The formation of mixed hexamers, decamers, dodecamers and tetradecamers are clearly favored from solution containing uracil (Ura), thymine (Thy) and Ca2+, whereas mixed octamers are preferred from 1-methyl uracil (MeU), uracil and Ca2+ mixtures. Cytosine (Cyto) can form mixed complexes with either uracil or 1-methyl uracil or thymine. On the other hand, the main species formed in these latter cases are mixed tetramers. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

The binding energy, equilibrium geometry, and vibration frequencies of free clusters Cu (2 ≤ n ≤ 20) are calculated using the potentials of interatomic interactions found using the tight-binding approximation. The nonmonotonic dependence of the clusters' minimum vibration frequency on their sizes and the extreme values for the number of atoms in a cluster n = 4, 6, 13, and 19 is demonstrated. It is noted that this result agrees with the theoretical and experimental data on stable structures of small and medium metallic clusters. [ABSTRACT FROM AUTHOR]

The shell and pairing correction energies are calculated for heavy and superheavy nuclei (SHN) by means of the Strutinsky's method. The single-particle (s.p.) energy levels are obtained from the diagonalization of the Woods-Saxon s.p. Hamiltonian in the deformed harmonic oscillator basis for both neutrons and protons. The residual pairing interaction is calculated by means of the usual Bardeen-Cooper-Schrieffer (BCS) approximation. A two-dimensional deformation space describing axially and reflection-symmetric shapes of nuclei has been used. Based on the shell and pairing correction energies, the signatures of the magic numbers appear at the spherical shell closures Z = 82, 114, 164 and N = 126, 184, 228 and 308. There are also signatures for some other shell closures at, e.g., Z = 108 and N = 162 which appear only when the deformation degrees of freedom is taken into account. [ABSTRACT FROM AUTHOR]

A new empirical formulae for the calculation of the ( n, p) reaction cross-sections at 14.5 MeV neutron energy has been proposed. The measured data for ( n, p) reaction cross-sections have been collected from the literature and analyzed for the isotopes having 3 ≤ Z ≤ 83. It has been found that σ versus Z/ A is more effective than σ versus S The odd-even effects have been observed as the cross-sections of odd-mass nuclei are higher than those of their neighboring even-even nuclei. [ABSTRACT FROM AUTHOR]

We investigate the magic number problem, that is, the question whether there exists a minimal n-state nondeterministic finite automaton (NFA) whose equivalent minimal deterministic finite automaton (DFA) has α states, for all n and α satisfying n ≤ α ≤ 2n. A number α not satisfying this condition is called a magic number (for n). It was shown that no magic numbers exist for general regular languages, whereas trivial and non-trivial magic numbers for unary regular languages were identified. We obtain similar results for automata accepting subregular languages like, for example, star-free languages, prefix-, suffix-, and infix-closed languages, and prefix-, suffix-, and infix-free languages, showing that there are only trivial magic numbers, when they exist. For finite languages we obtain some partial results showing that certain numbers are non-magic. [ABSTRACT FROM AUTHOR]

The nuclear shell model is a benchmark for the description of the structure of atomic nuclei. The magic numbers associated with closed shells have long been assumed to be valid across the whole nuclear chart. Investigations in recent years of nuclei far away from nuclear stability at facilities for radioactive ion beams have revealed that the magic numbers may change locally in those exotic nuclei leading to the disappearance of classic shell gaps and the appearance of new magic numbers. These changes in shell structure also have important implications for the synthesis of heavy elements in stars and stellar explosions. In this review a brief overview of the basics of the nuclear shell model will be given together with a summary of recent theoretical and experimental activities investigating these changes in the nuclear shell structure. [ABSTRACT FROM AUTHOR]

Since 2006 the ISOLTRAP mass spectrometer has provided high-precision masses of many short-lived nuclides located all across the nuclear chart with halflives down to a few 10 ms. These nuclides range from the two-proton halo candidate 17Ne, via the neutron-rich magic 80Zn and 132Sn, up to 229Rn which was identified for the first time. The results show that ISOLTRAP is a versatile tool well suited to address physics topics such as nuclear structure, stellar nucleosynthesis, or the weak interaction. [ABSTRACT FROM AUTHOR]

Copyright of Physics Essays is the property of Physics Essays Publication and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

When a person receives signals carrying information, they unconsciously group them into portions, or quanta. Therefore, the person believes that this signal grouping is a property of the signals themselves, and not a result of his participation. To perceive and interpret these signals, a person should possess certain knowledge, otherwise the received signals will be perceived as noise. Information is compared with the magic numbers developed by humanity as a result of long-term observation of social practices and incorporated into all peoples’ cultures. As a result, information is confirmed to be a property of living systems only. [ABSTRACT FROM AUTHOR]

Cryptographic algorithms installed on Internet of Things (IoT) devices suffer many attacks. Some of these attacks include the differential linear attack (DL). The DL attack depends on the computation of the probability of differential-linear characteristics, which yields a Differential-Linear Connectivity Table (DLCT). The DLCT is a probability table that provides an attacker many possibilities of guessing the cryptographic keys of any algorithm such as Serpent. In essence, the attacker firstly constructs a DLCT by using building blocks such as Substitution Boxes (S-Boxes) found in many algorithms' architectures. In depth, this study focuses on securing IoT devices against DL attacks used on Serpent algorithms by using three magic numbers mapped on a newly developed mathematical function called Blocker, which will be added on Serpent's infrastructure before being installed in IoT devices. The new S-Boxes with 32-bit output were generated to replace the original Serpent's S-Boxes with 4-bit output. The new S-Boxes were also inserted in Serpent's architecture. This novel approach of using magic numbers and the Blocker Function worked successfully in this study. The results demonstrated an algorithm for which its S-Box is composed of a 4-bit-output that is more vulnerable to being attacked than an algorithm in which its S-Box comprises 32-bit outputs. The novel approach of using a Blocker, developed by three magic numbers and 32-bits output S-Boxes, successfully blocked the construction of DLCT and DL attacks. This approach managed to secure the Serpent algorithm installed on IoT devices against DL attacks. [ABSTRACT FROM AUTHOR]

The experimental data for (n; 2n) reaction cross-sections around 14 MeV neutron energy have been collected from the literature and analysed for the isotopes having 1 ⩽ Z ⩽ 82. The empirical relations for the reaction cross-sections have been obtained, which show fairly good fits with the experimental values. The shell effects have been established at magic nucleon numbers for (n; 2n) reaction cross-sections around 14 MeV neutron energy. The odd-even effects have also been observed as the cross-sections for odd-mass nuclei are higher than their neighbouring even{even nuclei. [ABSTRACT FROM AUTHOR]

Copyright of Physics Essays is the property of Physics Essays Publication and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This is a brief biography of Maria Goeppert Mayer. We have tried to emphasise that even outstanding women like her had to suffer (and still suffer) great discrimination. In spite of the handicaps she achieved the highest scientific distinction. [ABSTRACT FROM AUTHOR]