Influence of Fe2O3 Doping on TiO2 Electrode for Enhancement Photovoltaic Efficiency of Dye-Sensitized Solar Cells

In this work, we report for the first time the improvement of the photovoltaic characteristics of dye-sensitized solar cells (DSSCs) by doping TiO₂ with Fe₂O₃. DSSCs were fabricated using various percentages of Fe₂O₃-doped TiO₂ composite nanoparticles. The Fe₂O₃-doped DSSCs exhibited a maximum conversion efficiency of 5.76% because of the effective electron transport. DSSCs based on Fe₂O₃-doped TiO₂ films showed better photovoltaic performance than cells fabricated with only TiO₂ nanoparticles. This result was attributed to the prevention of recombination between electrons in the TiO₂ conduction band with the dye or electrolytes. A mechanism was suggested based on impedance results, which indicated improved electron transport at the interface of the TiO₂/dye/electrolyte.     

Comparison between evaporative light scattering detection and charged aerosol detection for the analysis of saikosaponins

Saikosaponins are triterpene saponins derived from the roots of Bupleurum falcatum L. (Umbelliferae), which has been traditionally used to treat fever, inflammation, liver diseases, and nephritis. It is difficult to analyze saikosaponins using HPLC-UV due to the lack of chromophores. Therefore, evaporative light scattering detection (ELSD) is used as a valuable alternative to UV detection. More recently, a charged aerosol detection (CAD) method has been developed to improve the sensitivity and reproducibility of ELSD. In this study, we compared CAD and ELSD methods in the simultaneous analysis of 10 saikosaponins, including saikosaponins-A, -B₁, -B₂, -B₃, -B₄, -C, -D, -G, -H and -I. A mixture of the 10 saikosaponins was injected into the Ascentis^® Express C18 column (100 mm × 4.6 mm, 2.7 μm) with gradient elution and detection with CAD and ELSD by splitting. We examined various factors that could affect the sensitivity of the detectors including various concentrations of additives, pH and flow rate of the mobile phase, purity of nitrogen gas and the CAD range. The sensitivity was determined based on the signal-to-noise ratio. The best sensitivity for CAD was achieved with 0.1 mM ammonium acetate at pH 4.0 in the mobile phase with a flow rate of 1.0 mL/min, and the CAD range at 100 pA, whereas that for ELSD was achieved with 0.01% acetic acid in the mobile phase with a flow rate at 0.8 mL/min. The purity of the nitrogen gas had only minor effects on the sensitivities of both detectors. Finally, the sensitivity for CAD was two to six times better than that of ELSD. Taken together, these results suggest that CAD provides a more sensitive analysis of the 10 saikosaponins than does ELSD.     

Nanomechanical actuation driven by light-induced DNA fuel

We report the reversible nanomechanical actuation of a microcantilever driven by the light irradiation-induced conformational changes of i-motif DNA chains, which are functionalized on the cantilever's surface. It is shown that light irradiation-driven nanomechanical actuation can be manipulated using DNA hybridization and/or ionic concentrations.     

Nanosecond domain wall dynamics in ferroelectric Pb(Zr, Ti)O(3) thin films

Domain wall motion during polarization switching in ferroelectric thin films is fundamentally important and poses challenges for both experiments and modeling. We have visualized the switching of a Pb(Zr, Ti)O(3) capacitor using time-resolved x-ray microdiffraction. The structural signatures of switching include a reversal in the sign of the piezoelectric coefficient and a change in the intensity of x-ray reflections. The propagation of polarization domain walls is highly reproducible from cycle to cycle of the electric field. Domain wall velocities of 40 m s(-1) are consistent with the results of other methods, but are far less than saturation values expected at high electric fields.     

Visible-to-near infrared standard source generation using acetylene (C2H2)-stabilized comb-injection-locked technique

An ultra-stable visible laser source (VLS) was generated by the second harmonic of a selectively injection-locked distributed feedback (DFB) laser from an optical frequency comb with acetylene-stabilized laser seeding. For the second-harmonic generation (SHG) of the injection-locked DFB laser, we used periodically poled lithium niobate (PPLN) crystal and generated the VLS at a region of 771 nm, which was discretely locked to a spacing of 25 GHz within the PPLN bandwidth (180 GHz). The frequency stability of this source was estimated to be 1.1 × 10^− 12 with an average time of 1 s.     

Vacancies and B doping in Si nanocrystals

We examine the effect of vacancies on the doping of Si nanocrystals with B atoms. The electronic structure problem is solved in real space using pseudopotentials constructed within density functional theory. In the absence of vacancies, we find that it is energetically favorable for B dopants to be placed at or near the nanocrystal surface. However, in the presence of a vacancy, the B dopant can be stabilized within the nanocrystal as the vacancy effectively relieves the dopant induced stress.     

A survey of decision support system applications (1995–2001)

To extend two previous surveys of specific decision support system (DSS) applications over the period (January 1971–December 1994), we have conducted a follow-up survey covering the period between 1995 and 2001. A total of 210 published applications are identified. To examine the development pattern of a specific DSS over time, we analysed and summarized the survey results according to (1) the area of application, (2) the year of publication in each area of application, (3) the distribution of underlying tools in DSSs, (4) a classification based on Alter's taxonomy, and (5) the management level (operational, tactical, or strategic) for which the DSS was designed.     

Development and Validation of a Bioanalytical Method for 3′- and 6′-Sialyllactose in Minipig Liver and Kidney Using Liquid Chromatography-Tandem Mass Spectrometry and Its Application to Analysis of Tissue Distribution

Breast milk contains human milk oligosaccharides (HMOs), including sialyllactose (SL). SL is composed of sialic acid and lactose, and is divided into 3′-SL and 6′-SL according to the binding position. SL has immunoprotective effects against bacteria and viruses, and acts as a probiotic in the gastrointestinal tract. In this study, we developed a bioanalytical method for simultaneous analysis of 3′-SL and 6′-SL in liver and kidney tissues of Yucatan minipigs using liquid chromatography–tandem mass spectrometry (LC-MS/MS) under conditions optimized in our previous study. LC-MS/MS was performed using a hydrophilic interaction liquid chromatography (HILIC) column (50 mm × 2.1 mm, 3 μm) with a mobile phase consisting of 10 mM ammonium acetate in water (pH 4.5) and acetonitrile with gradient elution at a flow rate of 0.3 mL/min. A surrogate matrix method using water was applied for analysis of endogenous SL. The developed method was validated with regard to selectivity, linearity, precision, accuracy, the matrix effect, recovery, parallelism, dilution integrity, carryover, and stability according to the US Food and Drug Administration guidelines. We performed a tissue distribution study of minipigs, and analyzed liver and kidney tissues using the developed method to determine the tissue distribution of 3′-SL and 6′-SL. The tissue concentrations of 3′-SL and 6′-SL were readily measurable, suggesting that the method would be useful for evaluating the tissue distributions of these compounds in minipigs.