Search

Rapid and efficient identification of the geographical origin of Angelica gigas roots (dang-gui) was performed using DART–TOF–MS (direct analysis in real time–time of flight–mass spectrometry) based metabolomics. As an ambient desorption/ionization technique, DART–TOF–MS can provide soft ionization and rapid analysis of samples with little sample preparation so it has been advantageously applied to high-throughput metabolomics analysis. In order to develop an efficient tool for discriminating, particularly geographical origin of raw herbal medicine, we employed DART–TOF–MS fingerprinting on dang-gui from Korean and Chinese markets. Principal component analysis of DART–TOF–MS fingerprints gave distinctive clustering information among two species of A. gigas and A. sinensis so that we used only A. gigas species for the sequential experiment. Orthogonal projections to latent structures-discriminant analysis of A. gigas samples revealed the separation between samples cultivated in two countries. Major discriminating components were elucidated as decursin/decursinol angelate, unidentified molecular ion of m/z 247 (protonated ions of molecular formula of C14H14O4) and another molecular ion of m/z 432. DART–TOF–MS based chemical fingerprinting with the multivariate analysis of dang-gui was shown to be efficient and accurate way to identify its geographical origin, between Korea and China.

Inorganic light-emitting diodes and photodetectors represent important, established technologies for solid-state lighting, digital imaging and many other applications. Eliminating mechanical and geometrical design constraints imposed by the supporting semiconductor wafers can enable alternative uses in areas such as biomedicine and robotics. Here we describe systems that consist of arrays of interconnected, ultrathin inorganic light-emitting diodes and photodetectors configured in mechanically optimized layouts on unusual substrates. Light-emitting sutures, implantable sheets and illuminated plasmonic crystals that are compatible with complete immersion in biofluids illustrate the suitability of these technologies for use in biomedicine. Waterproof optical-proximity-sensor tapes capable of conformal integration on curved surfaces of gloves and thin, refractive-index monitors wrapped on tubing for intravenous delivery systems demonstrate possibilities in robotics and clinical medicine. These and related systems may create important, unconventional opportunities for optoelectronic devices.

Targeted mRNA degradation by short interfering RNAs (siRNAs) offers a great potential to treat cancers. siRNA therapeutics for leukemias are, however, hindered by poor intracellular uptake, limited blood stability and nonspecific delivery. To solve these problems, we developed an anti-JL1 immunonanoplex (antibody-coupled nanocomplex) for siRNA delivery using anti-JL1 minibody (leukemia cell-specific minibody) conjugated to oligo-9-Arg peptide (9R) for effective siRNA delivery to leukemic cells. The anti-JL1 immunonanoplexes were able to deliver siRNA specifically to leukemic cells (CEM and Jurkat), but not to control cancer cells (H9). According to FACS and confocal microscopic analysis, siRNAs delivered by immunonanoplex particles were rapidly taken up by the JL1-positive cancer cells in 2 h. Furthermore, we showed that the anti-JL1 immunonanoplexes were effectively targeted to JL1-positive cells (CEM) inoculated in the mouse bone marrow. These results suggest that the anti-JL1 immunonanoplex is a powerful siRNA delivery system for human leukemia therapies.

A meshfree method based on the first-order least-squares formulation for linear elasticity is presented. In the authors' previous work, the least-squares meshfree method has been shown to be highly robust to integration errors with the numerical examples of Poisson equation. In the present work, conventional formulation and compatibility-imposed formulation for linear elastic problems are studied on the convergence behavior of the solution and the robustness to the inaccurate integration using simply constructed background cells. In the least-squares formulation, both primal and dual variables can be approximated by the same function space. This can lead to higher rate of convergence for dual variables than Galerkin formulation. In general, the incompressible locking can be alleviated using mixed formulations. However, in meshfree framework these approaches involve an additional use of background grids to implement lower approximation space for dual variables. This difficulty is avoided in the present method and numerical examples show the uniform convergence performance in the incompressible limit. Therefore the present method has little burden of the requirement of background cells for the purposes of integration and alleviating the incompressible locking.

The effects of gas velocity, inlet gas temperature and the solid feed rate on the drying efficiency, the outlet solid moisture content, bed temperature in each stage, the outlet gas humidity and temperature in a rectangular acryl multistage fluidized bed (0.172 m×0.192 m×1.5 m-high) with a downcomer (0.04 m-I.D.) were investigated. The experiments were performed by using 1.9 mm millet particles. The final moisture contents of the solids increased with increasing the solid feed rate. The drying efficiency increased with increasing the wetted solid feed rate but decreased with increasing the inlet gas temperature. The drying performance of the multistage fluidized bed was compared with the single-stage fluidized bed and found to be superior under identical operation conditions. The model predicted values were well matched with the experimental data in the multistage fluidized bed dryer.

The effective thermal conductivities of bonded molding sands vary with the dry density, binder content, initial moisture content, temperature as well as the types of sand and binder clay. In this study, a theoretical model for predicting the effective thermal conductivities of bentonitebonded molding sands was developed. The results of measurement of the effective thermal conductivities of molding sands at temperatures up to 750°C were used. The binder thermal conductivities of both western bentonite and southern bentonite were suggested as a function of dry density, binder content and initial moisture content and were assumed not to vary with temperature. The radiation model proposed by Vortmeyer was also incorporated. The model developed in this study was proved to predict well the effects of binder content, initial moisture content, dry density and temperature.

Erratum to “Experimental study on heat transfer characteristics of water-spray-bed heat exchanger” [29 (5) (2015) 2243~2247] Sung Kook Hong, Sang-il Park, Soo-Yeon Jeon, and Kwan-Soo Lee Energy Efficiency Research Division, Korea Institute of Energy Research, Dajeon, 305-343, Korea R&D Center, SAC Corporate of Engineering, Asan-si, 336-748, Korea Mechanical Engineering, Hanyang University, Seoul, 133-791, Korea

The steady state solution of flow and temperature distributions in the crossflow moving bed heat exchanger using granular materials was obtained numerically. The effectiveness of crossflow moving bed was compared with that of crossflow heat exchanger with both fluids unmixed. The effect of bed geometry and solid particle size on the performance of moving bed was investigated. Also, the effect of thermal capacities of gas and solid particle and the gas flowrate was studied. The design data to estimate the heat exchanger performance of moving bed are given from the results of calculation in this study.

A model is developed to predict the effective thermal conductivity of a three-component system containing sand particles bonded with liquid binders. The effective thermal conductivities of the bonded and unbonded sands are measured by the line-heat-source method at room temperature. The parameters of a two-component model are determined from the measurements for unbonded sands. Finally the model for the three-component systems such as bonded sand is developed using the assumption of the coalescence of the liquid binder at the particle contact points. Comparison between the experimental results and the model predictions shows that the model developed in this study predicts well the effective thermal conductivities of fluid-saturated sand or sand bonded with liquid binders. Also, this model can be used to determine the effects of the parameters such as the thermal conductivities and the volume fractions of components and the geometrical characteristics of solid particles on the effective thermal conductivity of granular materials with or without the liquid binder.

The enhancement of optical transmittance at the air/glass interface of amorphous silicon thin film solar cells was shown by application of a nanoporous polymethyl methacrylate (PMMA) antireflection (AR) coating. The PMMA coating was prepared by spin coating of PMMA solution in chloroform in the presence of a small amount of nonane. Because of the difference of the vapor pressure of chloroform and nonane, phase separated structure formed after complete evaporation of both of them during spin coating process. The Corning 1737 glass with the AR coating has high transmittance near 95% from 450-1100nm wavelengths. The amorphous silicon solar cells with the nanoporous PMMA AR coating realize an improvement in quantum efficiency (QE) up to 4% in 450-650nm spectral regions.

Heat transfer characteristics of the countercurrent gas-solid flow inside verical pipes has been investigated with the shell and tube type heat exchanger. Sand particles having the average particle diameter of 1.0 and 1.7mm were used. The effect of gas velocity and sand paticle flow rate on the heat transfer rate and the pressure drop were examined. At room temperatures, the predicted pressure drop agrees well with the experimental results when the larger sand particles are used. The results shows that there exists an optimum sand particle flow rate at which the heat transfer rate become maximum. The increase in the heat transfer coefficient due to sand particles was obtained up to 62%.