Bidirectional carrier aggregation in next-generation radio-over-fiber heterogeneous network based on FBMC

We have projected and verified a bidirectional intra-/inter-radio-access-technology carrier-aggregation method for a next-generation heterogeneous mobile network supported by filter bank multicarrier(FBMC). Successful transmission of intra/inter-band carrier aggregation between five broadband FBMC signals and three bands 4G long-term-evolution-advanced signal over 50 km single-mode fiber plus 10 m free-space is successfully broadcasted by employing an incoherent light-injection scheme in downlink. In uplink, two intra-bands carrier-aggregated wireless local area network Institute of Electrical and Electronics Engineers 802.11 g signal is carried over the equal distance. High receiver sensitivity, low error vector magnitude, and clear constellation diagrams show successful delivery of different wireless services for different consumers. Therefore, the proposed hybrid system should become a potential solution for a future mobile front-haul network because of its low latency and high capacity.     

Design,synthesis, in silico and biological evaluation of novel 2-(4-(4-substituted piperazin-1-yl)benzylidene)hydrazine carboxamides

A series of novel 2-(4-(4-substituted piperazin-1-yl)benzylidene)hydrazinecarboxamide derivatives has been successfully designed and synthesized to evaluate their potential as carbonic anhydrase (CA) inhibitors. The inhibitory potential of synthesized compounds against human CAI and CAII was evaluated. Compounds 3a–n exhibited \(\hbox {IC}_{50}\) values between \(1.89{-}415.1\,\upmu \hbox {M}\) against CAI and \(0.62{-}66.9\,\upmu \hbox {M}\) against CAII. Compound 3g was the most active inhibitor, with an \(\hbox {IC}_{50}\) value of \(0.62\,\upmu \hbox {M}\) against CAII. Molecular docking studies of compound 3g with CAII showed this compound fits nicely in the active site of CAII and it interacts with the zinc ion (\(\hbox {Zn}^{2+}\)) along with three histidine residues in the active site. Molecular dynamics simulation studies of compound 3g complexed with CAII also showed essential interactions which were maintained up to 40 ns of simulation. In vivo sub-acute toxicity study using 3g (300 mg/kg) was found non-toxic in adult Wistar rats.     

Energy Fluctuation of Ideal Fermi Gas Trapped under Generic Power Law Potential U=Σ_(i=1)~d c_i|x_i/a_i|~(n_i) in d Dimensions

Energy fluctuation of ideal Fermi gas trapped under generic power law potential U=Σ_(i=1)~d c_i|x_i/a_i|~(n_i) has been calculated in arbitrary dimensions.Energy fluctuation is scrutinized further in the degenerate limit μK_B T with the help of Sommerfeld expansion.The dependence of energy fluctuation on dimensionality and power law potential is studied in detail.Most importantly our general result can not only exactly reproduce the recently published result regarding free and harmonically trapped ideal Fermi gas in d =3 but also can describe the outcome for any power law potential in arbitrary dimension.     

Superconductivity in the cuprates: Deduction of mechanism for d-wave pairing through analysis of ARPES

In the Eliashberg integral equations for d-wave superconductivity, two different functions (α²F)_n(ω, θ) and (α²F)_p,d(ω) determine, respectively, the “normal” self-energy and the “pairing” self-energy. ω is the frequency of fluctuations scattering the fermions whose momentum is near the Fermi-surface and makes an angle θ to a chosen axis. We present a quantitative analysis of the high-resolution laser based Angle Resolved Photoemission Spectroscopy (ARPES) data on a slightly under doped cuprate compound Bi2212 and use the Eliashberg equations to deduce the ω and θ dependence of (α²F)_n(ω, θ) for T just above T_c and below T_c. Besides its detailed ω dependence, we find the remarkable result that this function is nearly independent of θ between the (π; π)-direction and 25 degrees from it, except for the dependence of the cut-off energy on θ. Assuming that the same fluctuations determine both the normal and the pairing self-energy, we ask what theories give the function (α²F)_p,d(ω) required for the d-wave pairing instability at high temperatures as well as the deduced (α²F)_n(θ, ω). We show that the deduced (α²F)_n(θ, ω) can only be obtained from antiferromagnetic (AFM) fluctuations if their correlation length is smaller than a lattice constant. Using (α²F)_p,d(ω) consistent with such a correlation length and the symmetry of matrix-elements scattering fermions by AFM fluctuations, we calculate T_c and show that AFM fluctuations are excluded as the pairing mechanism for d-wave superconductivity in cuprates. We also consider the quantumcritical fluctuations derived microscopically as the fluctuations of the observed loop–current order discovered in the under-doped cuprates, and which lead to the marginal Fermi–liquid properties in the normal state. We show that their frequency dependence and the momentum dependence of their matrix-elements to scatter fermions are consistent with the θ and ω dependence of the deduced (α²F)_n(ω, θ). The pairing kernel (α²F)_p,d(ω) calculated using the experimental values in the Eliashberg equation gives d-wave instability at T_c comparable to the experiments.     

Structure and dynamics of water at liquid–vapour interfaces covered by surfactant monolayers of neutral stearic acid and charged stearate ions

The behaviour of water molecules at liquid–vapour interfaces with a surfactant monolayer of either stearic acid molecules or anionic stearate ions is investigated by means of molecular dynamics simulations. The density and dipolar orientational profiles and also the dynamics of translational and rotational motion of interfacial water molecules are calculated in the present work and the results are compared with the bulk liquid water and also of liquid–vapour interface of surfactant-free water. The present simulation results are also compared with available experimental results of similar interfacial systems with a monolayer of either neutral or ionic surfactants.     

Dynamic SIMS ion microscopy imaging of individual bacterial cells for studies of isotopically labeled molecules

A CAMECA IMS-3f SIMS ion microscope instrument capable of 500 nm spatial resolution was used for imaging single bacterial cells in the soil treated with ¹³C-labeled phenol in desired treatments. After formaldehyde fixation, the soil samples containing bacterial cells were smeared on the silicon substrate. The O₂⁺ primary ion beam was used for the detection of negative secondary ions. Images of individual bacterial cells were recorded on a CCD camera in masses 24, 25, 26, and 27 signals. The respective mass images represented contributions from the molecular ions of interest, for example ²⁴(¹²C₂)⁻, ²⁵(¹³C¹²C)⁻, ²⁶(¹²C¹⁴N)⁻, ²⁷(¹³C¹⁴N)⁻, as well as interfering mass species associated with a particular mass. However, in cells treated with ¹³C-labeled phenol the enhancement of signals in masses 25 and 27 images due to increased signals of ²⁵(¹³C¹²C)⁻ and ²⁷(¹³C¹⁴N)⁻, respectively, unequivocally indicated the presence of ¹³C-labeled phenol in bacterial cells in direct comparison to the samples treated only with unlabeled phenol. The ratio images of masses 25/24 and 27/26 from individual cells revealed a cell-to-cell heterogeneity in the labeling with ¹³C-phenol. This study indicates that the ion microscope can be applied effectively for studies of labeled molecules in microbiology and biogeochemistry.     

Magnetic and Mössbauer spectral studies of nano crystalline cobalt substituted magnesium ferrites (MgxCo1 − xFe2O4)

The electronic structure of the heme unit of deoxyhemoglobin including the proximal imidazole has been studied using the first-principles Hartree-Fock procedure. Our results for the ^57mFe isomer shift and asymmetry parameter are in very good agreement with the values obtained from Mössbauer spectroscopy measurements. The ^57mFe nuclear quadrupole coupling constant is smaller than the experimental result and possible ways to improve the agreement in the future are discussed. Improved analysis of the Mössbauer data, removing some approximations made for deriving the magnetic hyperfine tensor for the ^57mFe nucleus, is suggested to allow quantitative comparison with our results in the future.     

Magnetic and Mössbauer spectral studies of x (NiFe2O4) + (1−x)(SrFe12O19), x = 0, 0.2, 0.4, 0.6, 0.8 and 1.0 nanocomposites

Nano size composite of x(NiFe₂O₄)+(1?x)(SrFe₁₂O₁₉) were prepared using sol gel and aerosol route. The percentage of the components of NiFe₂O₄ and SrFe₁₂O₁₉ calculated from X-ray diffraction pattern using Rietveld analysis. The hysteresis loop for the as obtained samples exhibits no hysteresis, which may be attributed to super paramagnetic relaxation. The saturation magnetization do not show a significant change with the increase of strontium ferrites, however, the coercivity increased from 115 to 6,000 Oe. The Mössbauer spectra of these nano composites were discussed along with the magnetic moment and X-ray results.     

Study of the effect of SHI irradiation on nanocrystalline vacancy doped (La,Sr)(Mn,Fe)O system and its comparison with hydrostatic pressure using Mössbauer spectroscopy

The swift heavy ion irradiated La_0.9Mn_0.8Fe_0.2O₃ (La-deficient) system with 200 Mev Ag^16?+? ion beam at fluence 5 × 10¹² ions/cm² was studied with X-ray diffraction (XRD) and Mössbauer spectroscopic measurements. Comparison of Mössbauer parameters with those of unirradiated sample showed an increase in line width on irradiation which may be due to reduction in particle size as well as due to creation of defects. An increase in quadrupole splitting with no appreciable change in isomer shift showed ion-induced structural disorder in the material after irradiation. An attempt is made to compare the effect of fluence with the hydrostatic pressure on the sample.     

Effects of thermal buoyancy and variable thermal conductivity on the MHD flow and heat transfer in a power-law fluid past a vertical stretching sheet in the presence of a non-uniform heat source

The paper considers the flow of a power-law fluid past a vertical stretching sheet. Effects of variable thermal conductivity and non-uniform heat source/sink on the heat transfer are addressed. The thermal conductivity is assumed to vary linearly with temperature. Similarity transformation is used to convert the governing partial differential equations into a set of coupled, non-linear ordinary differential equations. Two different types of boundary heating are considered, namely Prescribed power-law Surface Temperature (PST) and Prescribed power-law Heat Flux (PHF). Shooting method is used to obtain the numerical solution for the resulting boundary value problems. The effects of Chandrasekhar number, Grashof number, Prandtl number, non-uniform heat source/sink parameters, wall temperature parameter and variable thermal conductivity parameter on the dynamics are shown graphically in several plots. The skin friction and heat transfer coefficients are tabulated for a range of values of the parameters. Present study reveals that in a gravity affected flow buoyancy effect has a significant say in the control of flow and heat transfer.