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Dissipative dynamics of nuclear fission is a well confirmed phenomenon described either by a Kramers-modified statistical model or by a dynamical model employing the Langevin equation. Though dynamical models as well as statistical models incorporating fission delay are found to explain the measured fission observables in many studies, it nonetheless shows conflicting results for shell closed nuclei in the mass region 200. Analysis of recent data for neutron shell closed nuclei in excitation energy range 40$-$80 MeV failed to arrive at a satisfactory description of the data and attributed the mismatch to shell effects and/or entrance channel effects, without reaching a definite conclusion. In the present work we show that a well established stochastic dynamical code simultaneously reproduces the available data of pre-scission neutron multiplicities, fission and evaporation residue excitation functions for neutron shell closed nuclei $^{210}$Po and $^{212}$Rn and their isotopes $^{206}$Po and $^{214,216}$Rn without the need for including any extra shell or entrance channel effects. The calculations are performed by using a phenomenological universal friction form factor with no ad-hoc adjustment of model parameters. However, we note significant deviation, beyond experimental errors, in some cases of Fr isotopes.

Measurements on mass , angular distributions, fusion-fission cross-sections of fission fragments from actinide nuclei $^{249}$Bk and $^{257}$Md, produced in fusion reactions $^{11}$B, $^{19}$F + $^{238}$U, and comparative studies with projectiles $^{12}$C, $^{16}$O,$^{30}$Si on same target with help of existing works are presented. The measured mass distribution data agree well with statistical model GEMINI++ predictions, the measured angular anisotropy data for $^{19}$F + $^{238}$U reaction exhibit deviation from the Transition State Model (TSM) results at energies below the fusion barrier. The fission cross-section data are reproduced fairly well using the coupled-channel CCFULL calculations. The microscopic TDHF quantum calculations also show no significant interplay between the orientation of the prolate deformed $^{238}$U whether tip to tip or side by side collision. Fusion-fission mechanism involving projectiles with atomic mass (A) 22 and charge 9 on actinide targets in the actinide chart are dominated by shell manifestation comparatively colliding partner's variables in reactions.

Ferroelectric hafnium zirconium oxide (HZO) thin films show significant promise for applications in ferroelectric random-access memory, ferroelectric field-effect transistors, and ferroelectric tunneling junctions. However, there are shortcomings in understanding ferroelectric switching, which is crucial in the operation of these devices. Here a computational model based on phase field method is developed to simulate the switching behavior of polycrystalline HZO thin films. Furthermore, we introduce a novel approach to optimize the effective Landau coefficients describing the free energy of HZO by combining the phase field model with a genetic algorithm. We validate the model by accurately simulating switching curves for HZO thin films with different ferroelectric phase fractions. The simulated domain dynamics during switching also shows amazing similarity to the available experimental observations. The present work also provides fundamental insights into enhancing the ferroelectricity in HZO thin films by controlling grain morphology and crystalline texture. It can potentially be extended to improve the ferroelectric properties of other hafnia based thin films., Comment: Supplementary information is available with the main manuscript

The precipitate shape, size and distribution are crucial factors which determine the properties of several technologically important alloys. Elastic interactions between the inclusions modify their morphology and align them along elastically favourable crystallographic directions. Among the several factors contributing to the elastic interaction energy between precipitating phases, anisotropy in elastic moduli is decisive in the emergence of modulated structures during phase separation in elastically coherent alloy systems. We employ a phase-field model incorporating elastic interaction energy between the misfitting phases to study microstructural evolution in ternary three-phase alloy systems when the elastic moduli are anisotropic. The spatiotemporal evolution of the composition field variables is governed by solving a set of coupled Cahn-Hilliard equations numerically using a semi-implicit Fourier spectral technique. We methodically vary the misfit strains, alloy chemistry and elastic anisotropy to investigate their influence on domain morphology during phase separation. The coherency strains between the phases and alloy composition alter the coherent phase equilibria and decomposition pathways. The degree of anisotropy in elastic moduli modifies the elastic interaction energy between the precipitates depending on the sign and magnitude of relative misfits, and thus determines the shape and alignment of the inclusions in the microstructure.

Most of the commercially important alloys are multicomponent, producing multiphase microstructures as a result of processing. When the coexisting phases are elastically coherent, the elastic interactions between these phases play a major role in the development of microstructures. To elucidate the key effects of elastic stress on microstructural evolution when more than two misfitting phases are present in the microstructure, we have developed a microelastic phase-field model in two dimensions to study phase separation in ternary alloy system. Numerical solutions of a set of coupled Cahn-Hilliard equations for the composition fields govern the spatiotemporal evolution of the three-phase microstructure. The model incorporates coherency strain interactions between the phases using Khachaturyan's microelasticity theory. We systematically vary the misfit strains (magnitude and sign) between the phases along with the bulk alloy composition to study their effects on the morphological development of the phases and the resulting phase separation kinetics. We also vary the ratio of interfacial energies between the phases to understand the interplay between elastic and interfacial energies on morphological evolution. The sign and degree of misfit affect strain partitioning between the phases during spinodal decomposition, thereby affecting their compositional history and morphology. Moreover, strain partitioning affects solute partitioning and alters the kinetics of coarsening of the phases. The phases associated with higher misfit strain appear coarser and exhibit wider size distribution compared to those having lower misfit. When the interfacial energies satisfy complete wetting condition, phase separation leads to development of stable core-shell morphology depending on the misfit between the core (wetted) and the shell (wetting) phases.

Hybrid Lead halide perovskites, despite having unique intrinsic properties with the possibility of flexible synthesis and device fabrication, still suffer from two fundamental issues, i.e. stability in external environment and toxicity due to lead. More recently, double perovskite materials have emerged as a promising choice. The main outcome from various studies on this class can essentially be summarized into two categories, (i) either they have indirect band gap or (ii) direct but large optical band gap, which are not suitable for solar devices. Here we propose a combinatorial set of stable double perovskite materials, Cs$_2$BB$^{'}$X$_6$ (for various B, B$^{'}$) (X=Cl,Br,I), which show indirect to direct band gap transition via small Pb$^{+2}$ doping. This kind of doping has helped to change the topology of band structure triggering an optically allowed transition from valence band maxima to conduction band minima. It also reduces the band gap significantly, bringing it well in the visible region. Simulation reveals comparable/higher absorption coefficient and solar efficiency with respect to the state of the art photovoltaic absorber material CH$_3$NH$_3$PbI$_3$. Our experimentally measured properties on Cs$_2$(Ag$_{0.75}$Pb$_{0.25}$)(Bi$_{0.75}$Pb$_{0.25}$)Br$_6$ agrees fairly well with the theoretical predictions. With higher stability than CH$_3$NH$_3$PbI$_3$, this material shows the potential to be a better candidate.

The fission fragment mass distributions have been measured in the reactions 16O + 184W and 19F+ 181Ta populating the same compound nucleus 200Pb? at similar excitation energies. It is found that the widths of the mass distribution increases monotonically with excitation energy, indicating the absence of quasi-fission for both reactions. This is contrary to two recent claims of the presence of quasi-fission in the above mentioned reactions., Comment: Accepted for publication as a regular article in Physical Review C

The structure of $^{70}$Ge has been studied through in-beam gamma ray spectroscopy. A new band structure is identified that leads to forking of the ground-state band into two excited bands. Band structures have been investigated using the microscopic triaxial projected shell model approach. The observed forking is demonstrated to result from almost simultaneous band crossing of the two neutron aligned and the \gamma-band built on this two-quasiparticle configuration with the ground-state band., Comment: 9 pages, 13 figures, Accepted for publication as a Regular Article in PRC. in Physical Review C, 24th Feb 2016

The central idea of compressed sensing is to exploit the fact that most signals of interest are sparse in some domain and use this to reduce the number of measurements to encode. However, if the sparsity of the input signal is not precisely known, but known to lie within a specified range, compressed sensing as such cannot exploit this fact and would need to use the same number of measurements even for a very sparse signal. In this paper, we propose a novel method called Compressed Shattering to adapt compressed sensing to the specified sparsity range, without changing the sensing matrix by creating shattered signals which have fixed sparsity. This is accomplished by first suitably permuting the input spectrum and then using a filter bank to create fixed sparsity shattered signals. By ensuring that all the shattered signals are utmost 1-sparse, we make use of a simple but efficient deterministic sensing matrix to yield very low number of measurements. For a discrete-time signal of length 1000, with a sparsity range of $5 - 25$, traditional compressed sensing requires $175$ measurements, whereas Compressed Shattering would only need $20 - 100$ measurements., Comment: 6 pages, 7 figures

Fission-fragment mass distributions were measured for 225,227Pa nuclei formed in fusion reactions of 19F + 206, 208Pb around fusion barrier energies. Mass-angle correlations do not indicate any quasi-fission like events in this bombarding energy range. Mass distributions were fitted by Gaussian distribution and mass variance extracted. At below-barrier energies, the mass variance was found to increase with decrease in energy for both nuclei. Results from present work were compared with existing data for induced fission of 224, 226Th and 228U around barrier energies. Enhancement in mass variance of 225, 227Pa nuclei at below-barrier energies shows evidence for presence of asymmetric fission events mixed with symmetric fission events. This is in agreement with the results of mass distributions of nearby nuclei 224, 226Th and 228U where two-mode fission process was observed. Two-mode feature of fission arises due to the shell effects changing the landscape of the potential energy surfaces at low excitation energies. The excitation-energy dependence of the mass variance gives strong evidence for survival of microscopic shell effects in fission of light actinide nuclei 225, 227Pa with initial excitation energy ~30 - 50 MeV.

We discuss the role of channel coupling in the surface properties of an inter-nuclear potential for heavy-ion reactions. To this end, we analyze the experimental quasi-elastic cross sections for the $^{12}$C + $^{105,106}$Pd and $^{13}$C + $^{105,106}$Pd systems using the coupled-channels approach by including the vibrational excitations in the target nuclei. While earlier studies have reported a negligible influence of vibrational excitation on the surface diffuseness parameter for spherical systems, we find a significant effect for the C+Pd systems. Our systematic study also reveals influence of transfer couplings on the surface diffuseness parameter., Comment: 7 pages, 5 figures. Phys. Rev. C, in press

Recognizing emotion from speech has become one the active research themes in speech processing and in applications based on human-computer interaction. This paper conducts an experimental study on recognizing emotions from human speech. The emotions considered for the experiments include neutral, anger, joy and sadness. The distinuishability of emotional features in speech were studied first followed by emotion classification performed on a custom dataset. The classification was performed for different classifiers. One of the main feature attribute considered in the prepared dataset was the peak-to-peak distance obtained from the graphical representation of the speech signals. After performing the classification tests on a dataset formed from 30 different subjects, it was found that for getting better accuracy, one should consider the data collected from one person rather than considering the data from a group of people., Comment: 2nd International Symposium on Computer Vision and the Internet, 2015; to appear in Procedia Computer Science Journal, Elsevier, 2015

The square and rectangular shape of the pixels in the digital images for sensing and display purposes introduces several inaccuracies in the representation of digital images. The major disadvantage of square pixel shapes is the inability to accurately capture and display the details in the objects having variable orientations to edges, shapes and regions. This effect can be observed by the inaccurate representation of diagonal edges in low resolution square pixel images. This paper explores a less investigated idea of using variable shaped pixels for improving visual quality of image scans without increasing the square pixel resolution. The proposed adaptive filtering technique reports an improvement in image PSNR., Comment: 4th International Conference on Advances in Computing, Communications and Informatics, August, 2015

Real-time detection of moving objects involves memorisation of features in the template image and their comparison with those in the test image. At high sampling rates, such techniques face the problems of high algorithmic complexity and component delays. We present a new resistive switching based threshold logic cell which encodes the pixels of a template image. The cell comprises a voltage divider circuit that programs the resistances of the memristors arranged in a single node threshold logic network and the output is encoded as a binary value using a CMOS inverter gate. When a test image is applied to the template-programmed cell, a mismatch in the respective pixels is seen as a change in the output voltage of the cell. The proposed cell when compared with CMOS equivalent implementation shows improved performance in area, leakage power, power dissipation and delay., Comment: To be published in IEEE Transactions on Very Large Scale Integration (VLSI) Systems

A {\gamma}-ray linear polarization measurement has been performed to directly determine the parities for the levels in 146Gd nucleus. High-spin states in this nucleus were populated in a reaction 115In + 34S at 140 MeV incident energy. Linearly polarized {\gamma} - rays emitted from oriented states were measured using a Compton polarimeter consisting of an array of 8 Compton-suppressed Clover detectors. Unambiguous assignments of the spin and parity have been made for most of the observed levels and changes made in the previously reported spin-parity assignments for a few levels. Shell model calculations performed with judicious truncation over the {\pi}(gdsh) valence space interpret the structure of only the low-lying levels up to J{\pi} = 19+ and 9-. N = 82 neutron-core breaking is found to be essential for high spin states with excitation energies Ex > 7 MeV., Comment: 29 pages, including 11 figures. Communicated to Physical Review C

An earlier measurement on the 4$^+$ to 2$^+$ radiative transition in $^8$Be provided the first electromagnetic signature of its dumbbell-like shape. However, the large uncertainty in the measured cross section does not allow a stringent test of nuclear structure models. The present paper reports a more elaborate and precise measurement for this transition, via the radiative capture in the $^4$He+$^4$He reaction, improving the accuracy by about a factor of three. The {\it ab initio} calculations of the radiative transition strength with improved three-nucleon forces are also presented. The experimental results are compared with the predictions of the alpha cluster model and {\it ab initio} calculations., Comment: 5 pages and 7 figures, Submitted to Physical Review Letters

We measure firm-level productivity changes in the Indian electricity sector during a period that witnessed several pro-market regulatory changes. Using information collected from multiple sources we construct a unique panel of generating firms and transmission and distribution utilities spanning the years 2000 to 2009. We employ a recently developed improvement in the Stochastic Frontier panel method that allows controlling for time-invariant unobserved heterogeneity. Using the method we jointly estimate inefficiency and exogenous determinants of inefficiency. We estimate a flexible translog production model and compute decomposition of productivity into components of changes in technology, efficiency, scale and price effect. During this period, especially post Electricity Act 2003, we observed a general decline in firm-level productivity at the mean rate of -1.6% per year. A positive and large technical change is observed in the sector at the rate of 8% per year, attributable possibly to newer capacity addition. Except for smaller gas based generators, inefficiency is observed to be increasing at the mean rate of 3.1% per year in the sector. Consistent with extant findings we also document no significant impact of un-bundling on firm-level efficiency.

The half-life of 7Be implanted in a C60 pellet and gold foil has been measured to be about the same within about 0.2%. Using a radiochemical technique, we also measured that the probability of formation of endohedral 7Be@C60 by nuclear implantation technique was (5.6+-0.45)%. It is known from earlier works that the half-life of endohedral 7Be@C60 is about 1.2% shorter than that of 7Be implanted in gold. An analysis of these results using linear muffin-tin orbital method calculations indicates that most of the implanted 7Be ions in fullerene C60 stay at a distance of about 5.3 Angstrom from the centers of nearest C60 molecules forming exohedral compounds and those who enter the fullerene cages go to the centers of the cages forming endohedral 7Be@C60 compounds., Comment: 5 pages, 1 figure, to be submitted to Physical Review C

The lifetime of the 3163 keV, 7/2$^-$ isomeric state in $^{35}Cl$ that decays by a stretched M2 transition to the $3/2^+$ ground state, has been re-measured using the Doppler Shift Attenuation Method, by gating on the 1185 keV transition which directly feeds this state. This eliminates the uncertainties in the measurement arising from the direct feedings from the continuum. A mean life of 0.6$^{+0.5}_{-0.2}$ ps has been obtained from the present work. This is considerably smaller than the adopted value 45.3(6) ps. Implication of this major reduction in the lifetime has been pointed out., Comment: To be published in the Proc. of International Workshop on Nuclear Structure Physics at the Extremes: New Directions (NUSPE 05), 21-24 March, 2005, Shimla India

Angular distribution measurements of $^2$H($^7$Be,$^7$Be)$^2$H and $^2$H($^7$Be,$^8$B)$n$ reactions at $E_{c.m.}\sim$~4.5 MeV were performed to extract the astrophysical $S_{17}(0)$ factor using the asymptotic normalization coefficient (ANC) method. For this purpose a pure, low emittance $^7$Be beam was separated from the primary $^7$Li beam by a recoil mass spectrometer operated in a novel mode. A beam stopper at 0$^{\circ}$ allowed the use of a higher $^7$Be beam intensity. Measurement of the elastic scattering in the entrance channel using kinematic coincidence, facilitated the determination of the optical model parameters needed for the analysis of the transfer data. The present measurement significantly reduces errors in the extracted $^7$Be(p,$\gamma$) cross section using the ANC method. We get $S_{17}$~(0)~=~20.7~$\pm$~2.4 eV~b., Comment: 15 pages including 3 eps figures, one figure removed and discussions updated. Version to appear in Physical Review C