A Systematic Approach for Interference Alignment in CSIT-less Relay-Aided X-Networks

The degrees of freedom (DoF) of an X-network with M transmit and N receive nodes utilizing interference alignment with the support of $J$ relays each equipped with $L_j$ antennas operating in a half-duplex non-regenerative mode is investigated. Conditions on the feasibility of interference alignment are derived using a proper transmit strategy and a structured approach based on a Kronecker-product representation. The advantages of this approach are twofold: First, it extends existing results on the achievable DoF to generalized antenna configurations. Second, it unifies the analysis for time-varying and constant channels and provides valuable insights and interconnections between the two channel models. It turns out that a DoF of \nicefrac{NM}{M+N-1} is feasible whenever the sum of the $L_j^2 \geq [N-1][M-1]$

Infrared and Raman Spectroscopic Characterization of Porphyrin and its Derivatives

Density functional theory (DFT) was employed to investigate protonation, deuteration, and substitution effects on the vibrational spectra of porphyrin molecules. The results of the calculations were compared with experimental data. The calculations show that meso‐substitutions produced a substantial shift in frequencies when the meso‐carbons within the parent porphine are involved in the vibrational motion of molecules, while protonation of the N atoms leads to a significant blue shift when the H atoms covalent bonded to the N atoms that are substantially involved in the vibrational motion. Deuteration of N atoms at the porphyrin core is found to result not only in a red shift in the frequencies of the corresponding peaks below 1600 cm-1, but also to generate new Raman bands of frequencies in the range of 2565–2595 cm-1, resulting from N‐D bond stretching. Also, the deuteration of O atoms within the sulfonato groups (‐SO3-) results in a new peak at near 2642 cm-1 due to O‐D bond stretching. Calculated IR spectra of the compounds studied here showed similar differences. Finally, we discuss solvent effects on the IR spectrum of TSPP

Geometric and Electronic Properties of Porphyrin and its Derivatives

In this chapter, we discuss protonation and substitution effects on the absorption spectra of porphyrin molecules based on density functional theory (DFT) and time-dependent DFT calculations. The results of the calculations are compared with experimental data. The calculations show that protonation of core nitrogen atoms of porphyrin and meso-substituted porphyrins produces a substantial shift in Soret and Q-absorption bands, relative to their positions in corresponding nonprotonated and nonsubstituted chromophores. A relaxed potential energy surface (RPES) scan has been utilized to calculate ground and excited state potential energy surface (PES) curves as functions of the rotation of one of the meso-substituted sulfonatophenyl groups about dihedral angles θ (corresponding to Cα─Cm─Cϕ─C) ranging from 40 to 130°, using 10° increments. The ground state RPES curve indicates that when the molecule transitions from the lowest ground state to a local state, the calculated highest potential energy barrier at the dihedral angle of 90° is only 177 cm−1. This finding suggests that the meso-sulfonatophenyl substitution groups are able to rotate around Cm─Cϕ bond at room temperature because the thermal energy (kBT) at 298 K is 207.2 cm−1. Furthermore, the calculations show that the geometric structure of the porphyrin is strongly dependent on protonation and the nature of the meso-substituted functional groups

The value of multimodality imaging for detection, characterisation and management of a wall adhering structure in the right atrium

The case presents a wall adherent structure in the right atrium in a young patient with peripheral tcell lymphoma followed by successful prolonged lysis therapy resulting in the resolution of the thrombus is presented. This case highlights the utility of multimodality imaging in an accurate assessment of the right atrium thrombus and the effectiveness of prolonged lysis therapy.peer-reviewe

Characterization of Dynamic Behaviors in a Hexapod Robot

This paper investigates the relationship between energetic effi- ciency and the dynamical structure of a legged robot’s gait. We present an experimental data set collected from an untethered dynamic hexapod, EduBot [1] (a RHex-class [2] machine), operating in four distinct manually selected gaits. We study the robot’s single tripod stance dynamics of the robot which are identified by a purely jointspace-driven estimation method introduced in this paper. Our results establish a strong relationship between energetic efficiency (simultaneous reduction in power consumption and in- crease in speed) and the dynamical structure of an alternating tripod gait as measured by its fidelity to the SLIP mechanics—a dynamical pattern exhibit- ing characteristic exchanges of kinetic and spring-like potential energy [3]. We conclude that gaits that are dynamic in this manner give rise to better uti- lization of energy for the purposes of locomotion. This work is supported in part by the National Science Foundation (NSF) under a FIBR Award 0425878. Yasemin Ozkan Aydin is supported by International Research Fellowship Programme of the Scientific and Technological Research Council of Turkey (TUBITAK). For more information: Kod*La