Hydration of Kr(aq) in dilute and concentrated solutions

Molecular dynamics simulations of water with both multi-Kr and single Kr atomic solutes are carried out to implement quasi-chemical theory evaluation of the hydration free energy of Kr(aq). This approach obtains free energy differences reflecting Kr-Kr interactions at higher concentrations. Those differences are negative changes in hydration free energies with increasing concentrations at constant pressure. The changes are due to a slight reduction of packing contributions in the higher concentration case. The observed Kr-Kr distributions, analyzed with the extrapolation procedure of Kr\"{u}ger, \emph{et al.}, yield a modestly attractive osmotic second virial coefficient, $B_2\approx -60~\mathrm{cm}^3$/mol. The thermodynamic analysis interconnecting these two approaches shows that they are closely consistent with each other, providing support for both.Comment: 6 pages, 7 figures. Revision follows the extrapolation procedure of Refs. 33 and 34 which works nicely. The thermodynamic results are now clearly consistent. The $k \rightarrow 0$ extrapolation of the Fourier transform was not was satisfactor

Authentication protocol for an IoT-enabled LTE networks

The Evolved Packet System-based Authentication and Key Agreement (EPS-AKA) protocol of the long-term evolution (LTE) network does not support Internet of Things (IoT) objects and has several security limitations, including transmission of the object’s (user/device) identity and key set identifier in plaintext over the network, synchronization, large overhead, limited identity privacy, and security attack vulnerabilities. In this article, we propose a new secure and efficient AKA protocol for the LTE network that supports secure and efficient communications among various IoT devices as well as among the users. Analysis shows that our protocol is secure, efficient, and privacy preserved, and reduces bandwidth consumption during authentication

An efficient parallel algorithm for the all pairs shortest path problem using processor arrays with reconfigurable bus systems

The all pairs shortest path problem is a class of the algebraic path problem. Many parallel algorithms for the solution of this problem appear in the literature. One of the efficient parallel algorithms on W-RAM model is given by Kucera [17]. Though efficient, algorithms written for the W-RAM model of parallel computation are too idealistic to be implemented on the current hardware. In this report we present an efficient parallel algorithm for the solution of this problem using a relatively new model of parallel computing, Processor Arrays with Reconfigurable Bus Systems. The parallel time complexity of this algorithm is O(log2 n) and processors complexity is n2 × n × n

Electronic states of PrCoO3_3: X-ray photoemission spectroscopy and LDA+U density of states studies

Electronic states of PrCoO$_3$ are studied using x-ray photoemission spectroscopy. Pr 3d$_{5/2}$ core level and valence band (VB) were recorded using Mg K$_\beta$ source. The core level spectrum shows that the 3d$_{5/2}$ level is split into two components of multiplicity 4 and 2, respectively due to coupling of the spin states of the hole in 3d$_{5/2}$ with Pr 4f holes spin state. The observed splitting is 4.5 eV. The VB spectrum is interpreted using density of states (DOS) calculations under LDA and LDA+U. It is noted that LDA is not sufficient to explain the observed VB spectrum. Inclusion of on-site Coulomb correlation for Co 3d electrons in LDA+U calculations gives DOS which is useful in qualitative explanation of the ground state. However, it is necessary to include interactions between Pr 4f electrons to get better agreement with experimental VB spectrum. It is seen that the VB consists of Pr 4f, Co 3d and O 2p states. Pr 4f, Co 3d and O 2p bands are highly mixed indicating strong hybridization of these three states. The band near the Fermi level has about equal contributions from Pr 4f and O 2p states with somewhat smaller contribution from Co 3d states. Thus in the Zaanen, Sawatzky, and Allen scheme PrCoO$_3$ can be considered as charge transfer insulator. The charge transfer energy $\Delta$ can be obtained using LDA DOS calculations and the Coulomb-exchange energy U' from LDA+U. The explicit values for PrCoO$_3$ are $\Delta$ = 3.9 eV and U' = 5.5 eV; the crystal field splitting and 3d bandwidth of Co ions are also found to be 2.8 and 1.8 eV, respectively.Comment: 12 pages, 7 figures; to appear J. Phys.: Condens. Matte