Dominance of Plasmonic Resonant Energy Transfer over Direct Electron Transfer in Substantially Enhanced Water Oxidation Activity of BiVO4 by Shape‐Controlled Au Nanoparticles

The performance of plasmonic Au nanostructure/metal oxide heterointerface shows great promise in enhancing photoactivity, due to its ability to confine light to the small volume inside the semiconductor and modify the interfacial electronic band structure. While the shape control of Au nanoparticles (NPs) is crucial for moderate bandgap semiconductors, because plasmonic resonance by interband excitations overlaps above the absorption edge of semiconductors, its critical role in water splitting is still not fully understood. Here, first, the plasmonic effects of shape‐controlled Au NPs on bismuth vanadate (BiVO₄) are studied, and a largely enhanced photoactivity of BiVO₄ is reported by introducing the octahedral Au NPs. The octahedral Au NP/BiVO₄ achieves 2.4 mA cm^?2 at the 1.23 V versus reversible hydrogen electrode, which is the threefold enhancement compared to BiVO₄. It is the highest value among the previously reported plasmonic Au NPs/BiVO₄. Improved photoactivity is attributed to the localized surface plasmon resonance; direct electron transfer (DET), plasmonic resonant energy transfer (PRET). The PRET can be stressed over DET when considering the moderate bandgap semiconductor. Enhanced water oxidation induced by the shape‐controlled Au NPs is applicable to moderate semiconductors, and shows a systematic study to explore new efficient plasmonic solar water splitting cells.     

Ontology based user query interpretation for semantic multimedia contents retrieval

Users who are familiar with the existing keyword-based search have problems of not being able to configure the formal query because they don’t have generic knowledge on knowledge base when using the semantic-based retrieval system. User wants the search results which are more accurate and match the user’s search intents with the existing keyword-based search and the same search keyword without the need to recognize what technology the currently used retrieval system is based on to provide the search results. In order to do the semantic analysis of the ambiguous search keyword entered by users who are familiar with the existing keyword-based search, ontological knowledge base constructed based on refined meta-data is necessary, and the keyword semantic analysis technique which reflects user’s search intents from the well-established knowledge base and can generate accurate search results is necessary. In this paper, therefore, by limiting the knowledge base construction to multimedia contents meta-data, the applicable prototype has been implemented and its performance in the same environment as Smart TV has been evaluated. Semantic analysis of user’s search keyword is done, evaluated and recommended through the proposed ontological knowledge base framework so that accurate search results that match user’s search intents can be provided.     

Hexafunctional poly(propylene glycol) based hydrogels for the removal of heavy metal ions

Two types of degradable poly(propylene glycol) (PPG) hydrogels that are suitable for the absorption of heavy metals have been presented. The PPG‐O‐P(O)Cl₂ fragments obtained by treating hexafunctional PPG with phosphorous oxychloride (POCl₃) react with 1,3‐propanediamine (PDA; Gel‐1 ) or PDA together with 1,2‐ethanedithiol ( Gel‐2 ), to yield cross‐linked and water‐swellable hydrogels in a one‐pot method. This protocol for the fabrication of PPG hydrogels exhibits promising advantages over prior methods including a short reaction time, mass‐production, easy separation, and high yield. A series of heavy metal ions were employed to test the adsorptive properties of the hydrogels. Gel‐2 shows better adsorption capacity than Gel‐1 for all the metal ions and the metal ions adsorption efficiency of the two types of hydrogels is in the order of Fe(III) > Pb(II) > Cd(II) > Zn(II) > Cu(II) > Ni(II) > Co(II) > Hg(II). The amounts of metal ions adsorbed increases with metal ion concentration and hydrogel dosage, but decreases with temperature. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40610.     

Characterization and In-vitro Permeation Study of Stearic Acid Nanoparticles containing Hinokitiol

Lipid nanoparticles containing hinokitiol (HKL) were prepared by a melt–emulsification method. Stearic acid was used as a lipid for the matrix material of the nanoparticles. According to results from transmission electron microscopy (TEM) and dynamic light scattering (DLS), most of the nanoparticles were less than 100 nm. When nanoparticles containing HKL were scanned on a differential scanning calorimeter, no endothermic peak of HKL was observed. This means that HKL in the lipid matrix of the nanoparticles is in a dissolved state. In an 18-h permeation study using hairless mouse skin mounted on a diffusion cell, the amount of HKL encapsulated in the nanoparticles transported to the receptor cell was five to ten times more than for HKL dissolved either ethanol or propylene glycol. Therefore, stearic acid nanoparticles strongly enhanced permeation of the skin by HKL.     

Nitrogenation of boron doped diamond: Comparison of an electrochemical treatment in liquid ammonia and a NH3/N2 plasma

In the present work, two different nitrogenation of diamond surface were studied onto moderately doped BDD samples (10¹⁹ at cm^? 3). The effects of an electrochemical treatment in liquid ammonia have been compared to those produced by NH₃/N₂ plasma. The evolution of surface terminations from “CH” to “CN” has been studied by XPS analyses for both nitrogenation methods. Angle contact measurements complete this work, estimating the effect of such treatments on BDD wettability properties. Finally, cyclic voltammetry in presence of redox systems have been carried out to evidence the impact of “CN” bonds on BDD electrochemical behavior. In both cases the formation of “CN” terminations was evidenced by XPS analyses. Physico-chemical properties of BDD electrodes, deduced from contact angle and electrochemical measurements, were strongly modified according the process. The galvanostatic treatment in liquid ammonia led to a more hydrophobic diamond surface and an improvement of the charge transfer with Ce^4+/3+ redox couple, while a more hydrophilic surface and a notable decrease of the electrochemical response were generated by NH₃/N₂ plasma treatment.     

Fast parametric imaging algorithm for dual-input biomedical system parameter estimation

Medical parametric imaging with dynamic positron emission tomography (PET) plays an increasingly potential role in modern biomedical research and clinical diagnosis. The key issue in parametric imaging is to estimate parameters based on sampled data at the pixel-by-pixel level from certain dynamic processes described by valid mathematical models. Classic nonlinear least squares (NLS) algorithm requires a "good" initial guess and the computational time-complexity is high, which is impractical for image-wide parameter estimation. Although a variety of fast parametric imaging techniques have been developed, most of them focus on single input systems, which do not provide an optimal solution for dual-input biomedical system parameter estimation, which is the case of liver metabolism. In this study, a dual-input-generalized linear least squares (D-I-GLLS) algorithm was proposed to identify the model parameters including the parameter in the dual-input function. Monte Carlo simulation was conducted to examine this novel fast algorithm. The results of the quantitative analysis suggested that the proposed technique could provide comparable reliability of the parameter estimation with NLS fitting and accurately identify the parameter in the dual-input function. This method may be potentially applicable to other dual-input biomedical system parameter estimation as well.     

Computation of a turbulent Rayleigh–Benard convection with the elliptic-blending second-moment closure

This communication reports briefly on the computational results of a turbulent Rayleigh–Benard convection with the elliptic-blending second-moment closure (EBM). The primary emphasis of the study is placed on an investigation of accuracy and numerical stability of the elliptic-blending second-moment closure for the turbulent Rayleigh–Benard convection. The turbulent heat fluxes in this study are treated by the algebraic flux model where the molecular dissipation rate of turbulent heat flux is included. The model is applied to the prediction of the turbulent Rayleigh–Benard convection for Rayleigh numbers ranging from Ra = 2 × 10⁶ to Ra = 10⁹, and the computed results are compared with the previous experimental correlations, T-RANS and LES results. The predicted cell-averaged Nusselt number follows the correlation by Peng et al. [S.H. Peng, K. Hanjalic, L. Davidson, Large-eddy simulation and deduced scaling analysis of Rayleigh–Benard convection up to Ra = 10⁹, J. Turbulence 7 (2006) 1–29.] (Nu = 0.162Ra^0.286) in the ‘soft’ convective turbulence region (2 × 10⁶ ≤ Ra ≤ 4 × 10⁷) and it follows the experimental correlation by Niemela et al. [J.J. Niemela, L. Skrbek, K.R., Sreenivasan, R.J. Donnelly, Turbulent convection at very high Rayleigh numbers, Nature 404 (2000) 837–840.] (Nu = 0.124Ra^0.309) in the ‘hard’ convective turbulence region (10⁸ ≤ Ra ≤ 10⁹) within 5% accuracy. This result shows that the elliptic-blending second-moment closure with an algebraic flux model predicts very accurately the Rayleigh–Benard convection.     

Fabrication of nano-sized emitting phosphors for photoluminescence films via hydro-thermal synthesis

Nano-sized red and blue emitting phosphors for a photoluminescence film were fabricated via hydrothermal synthesis through the sol-gel process. The nano-sized phosphors had a spherical shape such as the 60-110 nm Y2O2S:Eu3+ phosphor and the 45-90 nm of Y2SiO5:Ce phosphor. Firing at 1000 degrees C for 2 hours resulted in an increase in their size to 90-190 nm for the Y2O2S:Eu3+ phosphor and 70-160 nm for the Y2SiO5:Ce phosphor. Heat treatment of the gel powders of the emitting phosphors above 730 degrees C was recommended because of their crystallization. The maximum excitation and emission intensities of the red and blue phosphors with Y2O2S:Eu3+ and Y2SiO5:Ce were at the wavelengths of 308 nm and 617 nm, and 254 nm and 464 nm, respectively. The photoluminescence of the films increased as increasing the content of the red and blue phosphor powder mixture in the plastic films. The 100 microm-thick PVB film with the nano-sized phosphors showed the maximum photoluminescence of 537 x 1000 counts/sec.