A realistic technique for selection of angular momenta from hot nuclei: A case study with 4He + 115In \to 119Sb at E_Lab = 35 MeV

A rather new approach employing Monte Carlo GEANT simulation for converting the experimentally measured fold distribution to angular momentum distribution has been described. The technique has been successfully utilized to measure the angular momentum of the compound nucleus formed in the reaction 4He + 115In --> 119Sb at E_Lab = 35 MeV. A 50 element gamma multiplicity filter, fabricated in-house, was used to measure experimentally the required fold distribution. The present method has been compared with the other ones exiting in the literature and relative merits have been discussed.Comment: 11 pages, 10 figures, accepted for publication in NIM

Concise review on clinical applications of conditioned medium derived from human umbilical cord-mesenchymal stem cells (UC-MSCS)

In recent years, mesenchymal stem cells have provoked much attentiveness in the field of regenerative medicine because of their differentiation potential and the capability to facilitate tissue repair via the emancipation of biologically active molecules. They have gained interest because of their distinctive curative properties. Mesenchymal stem cells are isolated from the Wharton\u2019s jelly part of umbilical cord possessing higher proliferation capacity, immunomodulatory activity, plasticity, as well as self-renewal capacity than the mesenchymal stem cells from various origins, and it is considered to be the best resource for allogeneic transplantation. The isolated umbilical cord-derived mesenchymal stem cells are cultured in the Dulbecco\u2019s Modified Eagle\u2019s Medium, and thereby it begins to release soluble factors into the medium during the period of culture which is termed as conditioned medium. This conditioned media has both differentiation capacity and therapeutic functions. Thus, it can be able to differentiate the cells into different lineages and the paracrine effect of these cells helps in replacement of the damaged cells. This medium may accord to optimization of diagnostic and prognostic systems as well as the generation of novel and targeted therapeutic perspectives

Signature of clustering in quantum many body systems probed by the giant dipole resonance

The present experimental study illustrates how large deformations attained by nuclei due to cluster formation are perceived through the giant dipole resonance (GDR) strength function. The high energy GDR $\gamma$-rays have been measured from $^{32}$S at different angular momenta ($J$) but similar temperatures in the reactions $^{4}$He(E$_{lab}$=45MeV) + $^{28}$Si and $^{20}$Ne(E$_{lab}$=145MeV) + $^{12}$C. The experimental data at lower J ($\sim$ 10$\hbar$) suggests a normal deformation, similar to the ground state value, showing no potential signature of clustering. However, it is found that the GDR lineshape is fragmented into two prominent peaks at high J ($\sim$ 20$\hbar$) providing a direct measurement of the large deformation developed in the nucleus. The observed lineshape is also completely different from the ones seen for Jacobi shape transition at high $J$ pointing towards the formation of cluster structure in super-deformed states of $^{32}$S at such high spin. Thus, the GDR can be regarded as a unique tool to study cluster formation at high excitation energies and angular momenta.Comment: Published in PRC, 6 pages, 4 figure

Neutron response of the LAMBDA spectrometer and neutron interaction length in BaF2

We report on the neutron response of the LAMBDA spectrometer developed earlier for high-energy gamma-ray measurement. The energy dependent neutron detection efficiency of the spectrometer has been measured using the time-of-flight (TOF) technique and compared with that of an organic liquid scintillator based neutron detector (BC501A). The extracted efficiencies have also been compared with those obtained from Monte Carlo GEANT4 simulation. We have also measured the average interaction length of neutrons in the BaF2 crystal in a separate experiment, in order to determine the TOF energy resolution. Finally, the LAMBDA spectrometer has been tested in an in-beam-experiment by measuring neutron energy spectra in the 4He + 93Nb reaction to extract nuclear level density parameters. Nuclear level density parameters obtained by the LAMBDA spectrometer were found to be consistent with those obtained by the BC501A neutron detector, indicating that the spectrometer can be efficiently used as a neutron detector to measure the nuclear level density parameter.Comment: 7 pages, 8 figure

2017 Legislative Assembly election results: experts react

Yesterday the results were announced for five legislative elections held in Punjab, Uttar Pradesh, Uttarakhand, Manipur and Goa. Mukulika Banerjee, Surajit Bhalla, Meghnad Desai and Maitreesh Ghatak, who were at LSE for the fourth LSE SU India Forum, gathered to discuss key trends and features emerging from the results

Experimental signature of collective enhancement in nuclear level density

We present a probable experimental signature of collective enhancement in the nuclear level density (NLD) by measuring the neutron and the giant dipole resonance (GDR) $\gamma$ rays emitted from the rare earth $^{169}$Tm compound nucleus populated at 26.1 MeV excitation energy. An enhanced yield is observed in both neutron and $\gamma$ ray spectra corresponding to the same excitation energy in the daughter nuclei. The enhancement could only be reproduced by including a collective enhancement factor in the Fermi gas model of NLD to explain the neutron and GDR spectra simultaneously. The experimental results show that the relative enhancement factor is of the order of 10 and the fadeout occurs at $\sim$ 14 MeV excitation energy, much before the commonly accepted transition from deformed to spherical shape. We also explain how the collective enhancement contribution changes the inverse level density parameter ($k$) from 8 to 9.5 MeV observed recently in several deformed nuclei.Comment: 6 pages, 4 figures, Accepted in Phys. Rev. C (Rapid Communications

Scaling of the giant dipole resonance widths in hot rotating nuclei from the ground state values

The systematics of the giant dipole resonance (GDR) widths in hot and rotating nuclei are studied in terms of temperature T, angular momentum J and mass A. The different experimental data in the temperature range of 1 - 2 MeV have been compared with the thermal shape fluctuation model (TSFM) in the liquid drop formalism using a modified approach to estimate the average values of T, J and A in the decay of the compound nucleus. The values of the ground state GDR widths have been extracted from the TSFM parametrization in the liquid drop limit for the corrected T, J and A for a given system and compared with the corresponding available systematics of the experimentally measured ground state GDR widths for a range of nuclei from A = 45 to 194. Amazingly, the nature of the theoretically extracted ground state GDR widths matches remarkably well, though 1.5 times smaller, with the experimentally measured ground state GDR widths consistently over a wide range of nuclei.Comment: 15 pages, 4 figures, Accepted for publication in Physical Review