Computer construction of platonic solids

In this paper we develop a novel method to generate a 3D geometrical model from 2D planer images. As an example of application, we construct 3D models of each one of the five platonic solids from their platonic graphs

Compact stars within an asy-soft quark-meson-coupling model

We investigate compact star properties within the quark meson coupling model (QMC) with a soft symmetry energy density dependence at large densities. In particular, the hyperon content and the mass/radius curves for the families of stars obtained within the model are discussed. The hyperon-meson couplings are chosen according to experimental values of the hyperon nuclear matter potentials, and possible uncertainties are considered. It is shown that a softer symmetry energy gives rise to stars with less hyperons, smaller radii and larger masses. Hyperon-meson couplings may also have a strong effect on the mass of the star.Comment: 7 pages, revtex, accepted in Phys. Rev.

Structure and Decay Properties of Th Isotopes Using E-RMFT Formalism

In the present scenario, the search for the thermally fissile nuclei is crucial and also important not only for the research background of nuclear physics but also for the great social and economic impact on the country. Many theoretical works have been performed to analyze a series of Th and U-isotopes and found that some of these isotopes are stable against α-decays and spontaneous fission. Here, we have chosen the isotopic chain of Th-nuclei for the present analysis using relativistic mean-field formalism. The work also explores a few stable isotopes in this region of the nuclear landscape, which is crucial for understanding the exotic region of the nuclear landscape. The objective of this work is to study the bulk properties such as binding energies, root mean square charge radii, neutron-proton radii, neutron skin-thickness as well as intrinsic properties such as excitation energy and specific heat for the 216-238Th-isotopic chain. Furthermore, the stability of these isotopes is investigated through their possible decay chain analysis. The relativistic mean-field theory was used to obtain the nuclear bulk properties, namely, binding energies, root-mean-square charge radii, neutron skin-thickness, and excitation energy. The steady solution of the temperature-dependent effective relativistic mean-field equations was obtained self-consistently by taking different inputs of the initial deformations. All the calculations were done for NL3, FSUGarnet and IOPB-I parameter sets for 216-238Th-isotopes. The decay energy of α (Qα) and β-decay (Qβ) were calculated from the binding energies and were further used to obtain the corresponding half-lives. We have analyzed the structural and decay properties of 216-238Th isotopes. The excitation energy and specific heat are also estimated for these considered nuclei by using the temperature-dependent effective relativistic mean-field (E-RMFT) formalism for NL3, FSUGarnet and IOPB-I parameters sets. The calculated results are compared with the available experimental data and found similar observations for all the parameter sets at a given temperature. The excitation energy study signifies the shell melting point where maybe the shape transition occurs. Three phenomenological formulae such as Viola-Seaborg, Royer and modified universal decay law are adopted for the calculation of α-decay half-lives. We found lower values of α-decay half-lives indicating a higher rate of β-decay for the isotopic chain

Correlation between the nuclear structure and reaction dynamics of Ar-isotopes as projectile using the relativistic mean-field approach

This theoretical study is devoted to bridging the gap between the nuclear structure and reaction dynamics and unravelling their impact on each other, considering the neutron-rich light mass 30-60Ar isotopes. Using the relativistic mean-field with the NL3* parameter set, several bulk properties such as binding energies, charge radii, quadrupole deformation parameter, two neutron separation energy, and differential two neutron separation energy with the shell closure parameter are probed for the mentioned isotopic chain. For validation, the RMF (NL3*) results are compared with those obtained from the finite range droplet model (FRDM), Weizsacker-Skyrme model with WS3, WS* parameters and the available experimental data. Most of the participating isotopes are found to be prolate in structure and neutron shell closures are conspicuously revealed at N=14, 20, 40 but weakly shown at N=24, 28, 34. From our analysis, a central depletion in the nucleonic density is identified in 32Ar and 42-58Ar, indicating them as possible candidates for a semi-bubble-like structure. Interestingly, these results are consistent with recent theoretical and experimentally measured data. Besides, using the Glauber model, the reaction cross-sections are determined by taking 26-48Ar as projectiles and stable targets such as 12C, 16O, 40Ca, 90Zr, 124,132Sn, 208Pb and 304120. Although there is no experimental evidence for the stability of 304120, it has been predicted in Ref. [Mod. Phys. Lett. A {\bf 27}, 1250173 (2012)] as a stable nucleus. A relatively higher cross-section value is noticed between 30Ar and 32Ar which infers that 32Ar is the most stable isotope among the considered chain. Moreover, we noticed that the profile of the differential cross-sections and scattering angle are highly influenced by the mass of the target nuclei and the magnitude of the incident energy of the projectile nucleus.Comment: 19 pages, 7 figure

Assessment of seasonal groundwater quality using CHIDAM software in Virudhunagar district of Tamil Nadu.

Hard rock aquifer is the most predominant in the southern peninsula exclusively in Tamil Nadu, India. Virudhunagar district is situated in the South west part of Tamil Nadu, mostly of hard rock topography. Groundwater plays a major role in this area contributing to domestic, irrigation and industrial practices. Running down of groundwater by extreme consumption and less recharge in the study area has reduced the level of groundwater. On the other hand, intensive domestic, agriculture and industrial practices impacts the quality of quality of groundwater as well. Hydro geochemistry plays an important role in evaluation of suitability of groundwater for its usage in several purposes. A total of 72 samples from North East Monsoon (NEM) and Post Monsoon (POM) has been analyzed hydrochemically. The irrigation quality parameters such as sodium adsorption ratio (SAR), %Na, Residual Sodium Carbonate (RSC), Kelley’s index and Magnesium hazard were calculated using CHIDAM software 2020 in conjunction with USSL and Doneen diagrams. During NEM, EC and TDS ranges from 273 to 5869 mg/L and 194 to 4159 mg/L and during POM is from 235 to 6850 mg/L and 233.8 to 6916 mg/L. The hydrogeochemical facies represents that Ca-HCO3 and mixed Ca-Mg-Cl facies are predominant during NEM and Na-Cl and mixed Ca-Mg-Cl are predominant during POM. The higher concentration of TDS and EC in the samples reflects the unsuitability of groundwater in both seasons

Probing the superconducting ground state of ZrIrSi: A μ\muSR study

The superconducting ground state of newly reported ZrIrSi is probed by means of $\mu$SR technique along with resistivity measurement. The occurrence of superconductivity at $T_\mathrm{C}$ = 1.7 K is confirmed by resistivity measurement. ZF-$\mu$SR study revealed that below $T_\mathrm{C}$, there is no spontaneous magnetic field in the superconducting state, indicates TRS is preserved in case of ZrIrSi. From TF-$\mu$SR measurement, we have estimated the superfluid density as a function of temperature, which is described by an isotropic $s-$wave model with a superconducting gap $2\Delta(0)/k_\mathrm{B}T_\mathrm{C}$ = 5.1, indicates the presence of strong spin-orbit coupling. {\it Ab-initio} electronic structure calculation indicates that there are four bands passing through the Fermi level, forming four Fermi surface pockets. We find that the low-energy bands are dominated by the $4d$-orbitals of transition metal Zr, with substantially lesser weight from the $5d$-orbitals of the Ir-atoms.Comment: 6 pages, 4 figure

Investigation of Superconducting Gap Structure in HfIrSi using muon spin relaxation/rotation

Appearance of strong spin-orbit coupling (SOC) is apparent in ternary equiatomic compounds with 5$d$-electrons due to the large atomic radii of transition metals. SOC plays a significant role in the emergence of unconventional superconductivity. Here we examined the superconducting state of HfIrSi using magnetization, specific heat, zero and transverse-field (ZF/TF) muon spin relaxation/rotation ($\mu$SR) measurements. Superconductivity is observed at $T_\mathrm{C}$ = 3.6 K as revealed by specific heat and magnetization measurements. From the TF$-\mu$SR analysis it is clear that superfluid density well described by an isotropic BCS type $s$-wave gap structure. Furthermore, from TF$-\mu$SR data we have also estimated the superconducting carrier density $n_\mathrm{s}$ = 6.6 $\times$10$^{26}$m$^{-3}$, London penetration depth $\lambda_{L}(0)$ = 259.59 nm and effective mass $m^{*}$ = 1.57 $m_{e}$. Our zero-field muon spin relaxation data indicate no clear sign of spontaneous internal field below $T_\mathrm{C}$, which implies that the time-reversal symmetry is preserved in HfIrSi. Theoretical investigation suggests Hf and Ir atoms hybridize strongly along the $c$-axis of the lattice, which is responsible for the strong three-dimensionality of this system which screens the Coulomb interaction. As a result despite the presence of correlated $d$-electrons in this system, the correlation effect is weakened, promoting electron-phonon coupling to gain importance.Comment: 8 pages, 4 figure

Self-consistent quantum effects in the quark meson coupling model

We derive the equation of state of nuclear matter including vacuum polarization effects arising from the nucleons and the sigma mesons in the quark-meson coupling model which incorporates explicitly quark degrees of freedom with quark coupled to the scalar and vector mesons. This leads to a softer equation of state for nuclear matter giving a lower value of incompressibility than would be reached without quantum effects. The {\it in-medium} nucleon and sigma meson masses are also calculated in a self-consistent manner.Comment: 10 pages, latex, 5 figure