Potential games for energy-efficient resource allocation in multipoint-to-multipoint CDMA wireless data networks

The problem of noncooperative resource allocation in a multipoint-to-multipoint CDMA cellular network is considered in this paper. The considered scenario is general enough to represent several key instances of modern wireless networks such as a multicellular network, a peer-to-peer network (interference channel), and a wireless network equipped with femtocells. In particular, the problem of joint transmit waveforms adaptation, linear receiver design, and transmit power control is examined. Several utility functions to be maximized are considered, and, among them, we cite the received SINR, and the transmitter energy efficiency, which is measured in bit/J, and represents the number of successfully delivered bits for each energy unit used for transmission. Resorting to the theory of potential games, noncooperative games admitting Nash equilibria in multipoint-to-multipoint cellular networks regardless of the channel coefficient realizations are designed. Computer simulations confirm that the considered games are convergent, and show the huge benefits that resource allocation schemes can bring to the performance of wireless data networks.     

Analysis of a high redox potential heme in tetraheme cytochrome c3 by direct electrochemistry

Cytochrome c₃ from Desulfovibrio vulgaris (Miyazaki F), a redox protein, contains four bis-histidine-coordinated hemes and has lower redox potential than other heme proteins. Direct electrochemical measurements of cytochrome c₃ were carried out using a pyrolytic graphite edge (PGE) electrode. A low redox potential, already measured by redox titration, and a high redox potential (− 245 mV vs. Ag/AgCl) were observed at room temperature. The high redox potential of cytochrome c₃ was similar to that observed for the loss of an axial ligand at heme. To investigate the loss of the histidine ligand, we explored the electrochemistry of four cytochrome c₃ mutants, in which the sixth coordinated histidine was replaced by methionine. The electrochemistry of the cytochrome c₃ mutants indicated that only Heme III undergoes loss of its axial histidine ligand.     

Synthesis of Nanosized Silicon Carbide Through Non-Transferred Arc Thermal Plasma

A thermal plasma system was used for the preparation of nanosized SiC powder. First SiC was synthesized by solid-state reaction using waste silicon and activated carbon powders and then plasma processing was carried out to form nanosized SiC. Phase and structural analysis was carried out by X-ray diffraction which confirmed the formation of SiC in both cases. Plasma treatment did not show any kind of change in structure and phase of SiC; except little free silicon. Morphological investigation showed the formation of 20–30 nm spherical SiC particles after plasma treatment which was initially 1–5 μm. It was found that DC current played an important role in the reduction of particle size. It was proposed that nanosized SiC was formed due to the dissociation of grains from their grain boundary due to strong plasma gas stream.     

Multi-period defined contribution pension funds investment management with regime-switching and mortality risk

Using mean–variance criterion, we investigate a multi-period defined contribution pension fund investment problem in a Markovian regime-switching market. Both stochastic wage income and mortality risk are incorporated in our model. In a regime-switching market, the market mode changes among a finite number of regimes, and the market state process is modeled by a Markov chain. The key parameters, such as the bank interest rate, or expected returns and covariance matrix of stocks, will change according to the market state. By virtue of Lagrange duality technique, dynamic programming approach and matrix representation method, we derive expressions of efficient investment strategy and its efficient frontier in closed-form. Also, we study some special cases of our model. Finally, a numerical example based on real data from the American market sheds light on our theoretical results.     

Study on the performance of different types of three-dimensional chromatographic systems

The maximum achievable performance of possible types of three-dimensional chromatographic systems (LC × LC × LC) has been investigated. The Pareto-optimization approach was applied to establish a trade-off between three main objectives (total peak capacity, analysis time and dilution of the sample) and Pareto-front values were obtained. The performances of ^xLC × ^xLC × ^xLC (three-dimensional separation in space), ^tLC × ^tLC × ^tLC (three-dimensional separation in time) and the hybrid ^xLC × ^xLC × ^tLC system were compared mutually and with two-dimensional chromatographic systems. It was found that ^xLC × ^xLC × ^xLC performs best in terms of maximum achievable peak capacity in shortest analysis time. Based on current thin-layer-chromatography performance it should be possible to obtain a peak capacity of 50,000 within 20 min. If contemporary column-packing standards can be upheld the achievable limit is approximately 50% higher. However, in an ^xLC × ^xLC × ^xLC chromatographic system analytes remain in the separation domain after the analysis, which complicates the detection. Use of an ^xLC × ^xLC × ^tLC system with elution in the last dimension alleviates the detection problem. The maximum achievable peak capacity in the same analysis time is lower for ^xLC × ^xLC × ^tLC than for ^xLC × ^xLC × ^xLC. Using the same (reasonable) length of the separation domain (e.g. a cube 200 × 200 × 200 mm) for both systems, it is possible to achieve peak capacities of 78,000 for ^xLC × ^xLC × ^tLC operated in the gradient mode, which is twice higher than for an ^xLC × ^xLC × ^xLC system. A three-dimensional (three-column) time-based ^tLC × ^tLC × ^tLC system does not greatly improve the performance of ^tLC × ^tLC in terms of (maximum) peak capacity and (minimum) analysis time. Dilution factors in ^tLC × ^tLC × ^tLC are very high. Decreasing the dilution has a detrimental influence on the peak capacity. The trade-off between these objectives is of crucial importance. The influence of several parameters (length of the separation domain, particle size, etc.) on the performance of chromatographic systems was investigated, optimal ranges were found.     

Synthesis and characterization of Rosuvastatin calcium impurity A; a HMG-CoA reductase inhibitor

During the process development for multistep synthesis of Rosuvastatin calcium several impurities were obtained along with the final Rosuvastatin calcium. Out of this; synthesis of impurity A (acetone adduct) a minor impurity of Rosuvastatin calcium (3R,5S,6E)-7-[4-(4-fluorophenyl)-2-[[(2-hydroxy-2-methylpropyl)sulfonyl(methyl)amino]-6-(1-methylethyl)-pyrimidin-5-yl]-3,5-dihydroxyheptenoicacid hemicalcium salt, is described. The synthesis of impurity A has been accomplished in 6 steps; starting from formation of β-hydroxy sulfonamide as the key intermediate and followed by using convenient routes with overall yield of 13.5%. The target compound can be used as the reference substance of impurity of the Rosuvastatin calcium.     

Crystal structure,optical properties,and theory study of a 1-D bromoplumbate stabilized by in situ generated N-alkylated DABCO cation

We report the exploration of the stabilization effect of the in situ generated N-alkylated DABCO (DABCO = 1,4-diazabicyclo[2.2.2]octane) cation in the family of bromoplumbates and a 1-D bromoplumbate, (Et₂DABCO)_2n(Pb₃Br₁₀)_n (1), has been prepared by solvothermal conditions. Optical diffuse reflectance determination shows the band gap of 1 is 3.69 eV, which manifests that 1 is a wide band gap semiconductor. Compared with the band gap of bulk PbBr₂ (3.84 eV), 1 exhibits 0.15 eV red shift of absorption edge. While for the reported iodo analogs of this compound, (MPDA)_2n(Pb₃I₁₀)_n and (Et₂DABCO)_2n(Pb₃I₁₀)_n, they exhibit 0.53 and 0.47 eV blue shift of the energy gaps compared with the measured value of 2.30 eV for bulk PbI₂, respectively. The photoluminescent study of 1 shows that it exhibits a broad emission band centered at 697 nm upon photoexcitation by 345 nm (amount to 3.59 eV). The calculated density of states manifests the theoretical value of the band gap of 1 is 3.422 eV and the origination of photoluminescence can be ascribed to the transition of bonding electrons of Br^– anion to the empty orbits of Pb(II) ion.     

Inverse gas chromatography for natural fibre characterisation: dispersive and acid-base distribution profiles of the surface energy

Inverse Gas Chromatography (IGC) is a gas sorption technique to determine the surface energy of natural fibres. The surface energy is directly related to the thermodynamic work of adhesion and it reflects the fibre adsorption capacity and its wettability. However, natural fibres have a complex surface chemistry of numerous organic species and present physical asperities that render the surface energetically heterogeneous. Since IGC is typically performed at infinite dilution where only the higher energetic sites interact with the solvent, a single measure of surface energy is likely to be misleading as the surface energy changes with changing chemical composition. Here we present the dispersive and acid-base surface energy profiles of flax and kenaf fibres as well as continuous filament fibres produced by a dry jet, wet spinning process (cellulose B). We injected a series of n-alkanes at finite dilution to obtain the dispersive energy distribution profile at \(30\,^{\circ }\hbox {C}\) and 0% RH. The acid-base contributions were determined by injection of mono polar probes (dichloromethane, ethylacetate) at the same surface coverages and applying the Van Oss method. The cellulose B fibres were the most energetically homogeneous, while the bast fibres were shown to have a higher polar component and much broader surface energy distributions than the cellulose fibres.     

Thermodynamics of krypton adsorption on microporous carbon adsorbent at high pressures

The behavior of the thermodynamic functions for the adsorption system krypton—microporous carbon sorbent ACC is described. The dependences of the differential molar isosteric heat of adsorption, entropy, enthalpy, heat capacity, and differential molar energy of the adsorption system on the adsorption equilibrium parameters were studied over the temperature range from 178 to 393 K and at pressures ranging from 1 to 6?106 Pa. Consideration of the non-ideality of gas phase and non-inertness of the adsorbent leads to a temperature dependence of the thermodynamic functions of the studied adsorption system, especially in the range of high pressures of the adsorptive. The non-ideality of the gas phase and the energetics of the adsorbent—adsorbate system exert the most significant effect on the thermodynamic functions. The non-inertness of the adsorbent in the investigated range of parameters of the adsorption system has a weak effect on the thermodynamic functions of adsorption. In the region of high filling of ACC micropores, the entropy increases, indicating the existence of processes, which change the structure of the adsorbate in the micropores, in particular, to form associates.     

Ultrasonic pre-treatment modifies the pH-dependent molecular interactions between β-lactoglobulin and dietary phenolics: Conformational structures and interfacial properties

There is a need to understand the ultrasound-induced changes in the interactions between proteins and phenolic compounds at different pH. This study systematically explored the role of high-intensity ultrasound pre-treatment on the binding mechanisms of β-lactoglobulin (β-LG) to two common phenolic compounds, i.e., (−)-epigallocatechin-3-gallate (EGCG) and chlorogenic acid (CA) at neutral and acidic pH (pH 7.2 and 2.4). Tryptophan fluorescence revealed that compared to proteins sonicated at 20% and 50% amplitudes, 35%-amplitude ultrasound pre-treatment (ULG-35) strengthened the binding affinities of EGCG/CA to β-LG without altering the main interaction force. After phenolic addition, ULG-35 displayed a similar but a greater extent of protein secondary and tertiary structural changes than the native protein, ascribed to the ultrasound-driven hydrophobic stacking among interacted molecules. The dominant form of β-LG (dimer/monomer) played a crucial role in the conformational and interfacial properties of complexes, which can be explained by the distinct binding sites at different pH as unveiled by molecular docking. Combining pre-ultrasound with EGCG interaction notably increased the foaming and emulsifying properties of β-LG, providing a feasible way for the modification of bovine whey proteins. These results shed light on the understanding of protein–phenolic non-covalent binding under ultrasound and help to develop complex systems with desired functionality and delivery.