Binary and Ternary Fragmentation Analysis of 252Cf Nucleus using Different Nuclear Radii

Pioneering study reveals that a radioactive nucleus may split into two or three fragments and the phenomena are known as binary fission and ternary fission respectively. In order to understand the nuclear stability and related structure aspects, it is of huge interest to explore the fragmentation behavior of a radioactive nucleus in binary and ternary decay modes. In view of this, Binary and ternary fission analysis of 252Cf nucleus is carried out using quantum mechanical fragmentation theory (QMFT). The nuclear potential and Coulomb potential are estimated using different versions of radius vector. The fragmentation structure is found to be independent to the choice of fragment radius for binary as wellas ternary decay paths. The deformation effect is included up to quadrupole (β2) with optimum cold orientations and their influence is explored within binary splitting mode. Moreover, the most probable fission channels explore the role of magic shell effects in binary and ternary fission modes.

Complete and incomplete fusion cross-sections for 7Li+119Sn reaction using different approaches

277-281In reference to complete fusion (CF) and incomplete fusion (ICF) processes, the analysis of 7Li+119Sn reaction forming 126I compound nucleus (CN) is carried out at incident energies spread across the Coulomb barrier. Firstly, the total fusion (TF) cross-sections are calculated using the Wong formula. Since, it overestimates the experimental data, so ℓ-summed Wong approach is employed to address the TF cross-section, which limits the contribution of partial waves up to ℓ max value. Within ℓ-summed Wong model, the energy dependent selection function is used to separate out the contributions of CF and ICF from the TF cross-sections. This phenomenological selection function seems to give adequate distribution of CF and ICF cross-sections at higher energies. Beside this, the CF and ICF contributions are also separated out on the basis of angular momentum window and by using the energy correction formula. In the angular momentum distribution case, CF and ICF cross-sections are estimated in view of ℓ-windows, 0≤ℓcritical(for CF) and ℓcritical≤ ℓ ≤ℓmax(For ICF). Finally, in energy normalization case, the incident energy of 7Li beam (7Li→4He + 3H) is distributed among alpha and tritium fragments, and the ICF cross-sections for 3H+119Sn ICF channel are estimated using the ℓ-summed Wong model

Private Data Transfer over a Broadcast Channel

We study the following private data transfer problem: Alice has a database of files. Bob and Cathy want to access a file each from this database (which may or may not be the same file), but each of them wants to ensure that their choices of file do not get revealed even if Alice colludes with the other user. Alice, on the other hand, wants to make sure that each of Bob and Cathy does not learn any more information from the database than the files they demand (the identities of which will be unknown to her). Moreover, they should not learn any information about the other files even if they collude. It turns out that it is impossible to accomplish this if Alice, Bob, and Cathy have access only to private randomness and noiseless communication links. We consider this problem when a binary erasure broadcast channel with independent erasures is available from Alice to Bob and Cathy in addition to a noiseless public discussion channel. We study the file-length-per-broadcast-channel-use rate in the honest-but-curious model. We focus on the case when the database consists of two files, and obtain the optimal rate. We then extend to the case of larger databases, and give upper and lower bounds on the optimal rate.Comment: To be presented at IEEE International Symposium on Information Theory (ISIT 2015), Hong Kon

Promoting physical activity in upper elementary children using multi-theory model (MTM) of health behavior change

Background: Physical activity and exercise offer numerous benefits to children and Centers for Disease Control and Prevention guidelines require that school children engage in at least 60 minutes of moderate to vigorous physical activity every day.  Unfortunately, up to 30% elementary students do not meet these requirements and 79% elementary schools do not provide students with physical education classes every day. The transition from elementary to secondary school is particularly deleterious for levels of physical activity. Therefore, there is a need to develop educational interventions for upper elementary school children to promote physical activity. A new theory multi-theory model (MTM) of health behavior change can be utilized to develop such interventions.Objectives: The purpose of this article was to develop and introduce an instrument based on MTM for physical activity change in upper elementary school children and propose an approach for changing this behavior among sedentary students.Methods: A review of literature in MEDLINE, CINAHL, Google Scholar, and ERIC databases was conducted for physical activity in upper elementary children and multi-theory model of health behavior change to prepare this article. Results: An instrument with Flesch-Kincaid Grade level of 5.4 and the Flesch Reading Ease of 68 making it suitable for administration with upper elementary school children was developed. An approach utilizing the constructs of participatory dialogue, behavioral confidence and changes in physical environment to initiate physical activity and reifying the constructs of emotional transformation, practice for change and changes in social environment to sustain physical activity in upper elementary school children is presented.Conclusions: MTM offers potential to augment current educational efforts to promote physical activity in upper elementary school children

New approach for promoting HPV vaccination in college men based on multi-theory model (MTM) of health behavior change

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Critical Properties of Symmetric Nuclear Matter in Low-Density Regime Using Effective-Relativistic Mean Field Formalism

The effective field theory motivated relativistic mean-field (E-RMF) formalism is employed to study the equation of state (EoS) for the infinite symmetric nuclear matter at finite temperature using the recently developed forces FSUGarnet, IOPB-I, G3, and the well known NL3 force parameter. The EoS is then used to estimate the critical temperature $T_c$, pressure $P_c$ and density $\rho_c$ of the symmetric nuclear matter for the liquid-gas phase transition. As $T_c$ is not a constrained parameter in both experiments and theoretical calculations, there is a large uncertainty around its value. Although, the critical parameters are correlated among themselves. It is revealed that vector self-coupling $\zeta_0$ of used forces play determining role in EoS in finite temperature limit. Keeping the incompressibility in acceptable limit i.e. 240$\pm$ 20 MeV, the lower value of $\zeta_0$ gives a better result of $T_c$ when compared to the several experimental data. The critical parameters however show weak correlation with the properties at saturation density at zero temperature. The compressibility factors calculated with these parameters are in agreement with the universal value of liquid-gas systems. Stability conditions are examined along with binodal and spinodal regions. Besides this, the thermodynamic properties like specific heat and latent heat are also worked out. We have carried out detailed consistency check of our calculations using critical exponents and standard scaling laws. All the exponents are well within the theoretical mean-field results

Properties of hot finite nuclei and associated correlations with infinite nuclear matter

This work aim to study the various thermal characteristics of nuclei in view of the saturation and critical behavior of infinite nuclear matter. The free energy of a nucleus is parametrized using the density and temperature-dependent liquid-drop model and interaction among nucleons is worked out within the effective relativistic mean-field theory (E-RMF). The effective mass (m,$^*$) and critical temperature of infinite symmetric nuclear matter ($T_c$) of a given E-RMF parameter force play a seminal role in the estimation of thermal properties. A larger (m$^*$) and $T_c$ of the E-RMF set estimate larger excitation energy, level density, and limiting temperature $(T_l)$ for a given nucleus. The limiting temperature of a nucleus also depends on the behavior of the nuclear gas surrounding the nucleus, making the equation of state (EoS) at subsaturation densities an important input. A stiff EoS in the subsaturation region estimates a higher pressure of the nuclear gas making it less stable. Since the $T_c$ plays an important part in these calculations, we perform a Pearson correlation statistical study of fifteen E-RMF parameter sets, satisfying the relevant constraint on EoS. Effective mass seems to govern the thermal characteristics of infinite as well as finite nuclear matter in the framework of E-RMF theory.Comment: 13 pages, 9 figure

Thermal effects in hot and dilute homogeneous asymmetric nuclear matter

We present a comprehensive analysis of hot and dilute isospin-asymmetric nuclear matter employing the temperature-dependent effective-relativistic mean-field theory (E-RMF). The E-RMF is applied to study the effect of $\delta$ and $\omega-\rho$ meson cross-coupling on the thermal properties of asymmetric nuclear matter using two recently developed IOPB-I and G3 parameter sets. These sets are known to reproduce the nuclear matter properties in agreement with various experimental and observational constraints. We consider the nuclear matter to be homogeneous and study the equation of state (EoS) for densities, temperature and asymmetry which are relevant for astrophysical simulations such as supernovae explosion. The effect of temperature is investigated in reference to the density-dependent free symmetry energy and its higher-order derivatives using the well known parabolic approximation. The larger value of $\lambda_\omega$ cross-coupling in G3 in addition to the $\delta$ meson coupling in G3 smoothen the free symmetry energy. Thermal effects on various state variables are examined at fixed temperature and isospin asymmetry by separating their T=0 and the finite-T expressions. The thermal effects are mainly governed by effective mass with larger effective mass estimating larger thermal contribution. The effect of temperature on isothermal and isentropic incompressibility is discussed which is in harmony with various available microscopic calculations. The liquid-gas phase transition properties are examined in asymmetric matter with two conserved charges in the context of different slope parameter and comparable symmetry energy in IOPB-I and G3 set. The spinodal instability, binodal curve and critical properties are found to be influenced by the slope parameter $L_{sym}$