The use of plastic optical fibers in photocatalysis of trichloroethylene

In this study, plastic optical fibers (POFs) were considered as light-transmitting media and substrates for the potential use in photocatalytic environmental purification system and the performance of POFs was also compared with that of quartz optical fibers (QOFs). After the characteristic of POFs in terms of light transmittance was determined in the beginning, detailed investigation was further conducted through the photocatalytic degradation of trichloroethylene. It is concluded that the use of POFs is preferred to QOFs since the advantages such as ease of handling, lower cost, relatively reasonable light attenuation at the wavelength of near 400 nm can be obtained.     

Communication enhancer—appliances for better communication in a family

The aim of the exploratory study described in this paper was to develop appliance concepts which can enhance family communication by using digital technologies.     

The application of flip-chip bonding interconnection technique on the module assembly of 10 Gbps laser diode

Flip chip bonding technique using Pb/In solder bumps was applied to packaging of a 10 Gbps laser diode (LD) submodule for high speed optical communication systems. The effect of the flip-chip bonding interconnection technique instead of conventional wire bonding was investigated for high speed broad band devices. The broad band performance of 10 Gbps LD submodule was simulated using SPICE S/W and compared with experimental results. In this simulation, the 10 Gbps LD was modeled in a parallel RC circuit. The values of R and C used for the equivalent circuit were 5ω and 1 pF, respectively. The LD was placed in series with a 18ω thin film resistor to prevent the impedance mismatch between the LD and a 25ω transmission line. The dependence of parasitic parameters on the small signal modulation bandwidth and the scattering parameters of the LD submodule was investigated and analyzed up to 20 GHz. A small signal modulation bandwidth of 14 GHz at 10 mA dc bias current and the clean modulation response up to 20 GHz were found for the flip-chip bonded submodule. The bandwidth of flip-chip bonded 10 Gbps LD submodule is wider than that of the wire-bonded LD submodule by a difference of 3.8 GHz.     

Efficient Transdermal Delivery of DNA Nanostructures Alleviates Atopic Dermatitis Symptoms in NC/Nga Mice

DNA nanostructures have been widely studied in biomedical research contributing to targeted treatment of chronic diseases. The immunostimulatory X_L‐DNA nanostructures of X‐shaped oligodeoxynucleotides complex are previously reported, activating toll‐like receptor9 in dendritic cells. This study examines whether the X_L‐DNA could be therapeutically applied to treat immune diseases such as atopic dermatitis. To optimize topical delivery, liposome‐encapsulated X_L‐DNA (Lipo‐X_L‐DNA) is generated using emulsion transfer method with lipid layers composed of 1,2‐dioleoyl‐sn‐glycero‐3‐phosphocholine, 1,2‐dioleoyl‐sn‐glycero‐3‐phospho‐(1′‐rac‐glycerol), and cholesterol. Size distribution of Lipo‐X_L‐DNA ranges around 90–160 nm with mean diameter of 115.44 ± 18.72 nm. The morphology is confirmed by transmission electron microscope. Zeta potential is ?28.59 mV. Confocal microscopy shows that Lipo‐X_L‐DNA is efficiently delivered into epidermis and dermis. Topical application of Lipo‐X_L‐DNA effectively alleviates atopic dermatitis symptoms in mice, as shown by dermatitis score, histological evaluation, and serum immunoglobulin E levels. RNA‐seq analysis confirms that Lipo‐X_L‐DNA reduces pro‐inflammatory products, but increases epidermal barrier homeostasis factors in atopic dermatitis lesions. Lipo‐X_L‐DNA orchestrates immune balance by downregulating Th2 immunity, but upregulating Th1 immunity. Collectively, liposome encapsulation enables efficient transdermal delivery of X_L‐DNA, for an effective treatment of atopic dermatitis in mice. The results provide a promising therapeutic strategy using X_L‐DNA nanostructures to treat immune‐compromised diseases.     

Unveiling the Role of Dopant Polarity in the Recombination and Performance of Organic Light‐Emitting Diodes

The recombination of charges is an important process in organic photonic devices, because the process influences the device characteristics such as the driving voltage, efficiency, and lifetime. Here, by using various homoleptic and heteroleptic Ir complexes as dopants, it is reported that the stationary dipole moment (μ₀) of the dopant rather than the trap depth (ΔE_t ) is a major factor determining the recombination mechanism in dye‐doped organic light‐emitting diodes (OLEDs). Dopants with large μ₀ (e.g., homoleptic Ir(III) dyes) induce large charge trapping on them, resulting in high driving voltage and trap‐assisted recombination‐dominated emission. On the other hand, dyes with small μ₀ (e.g., heteroleptic Ir(III) dyes) show Langevin recombination‐dominated emission characteristics with much less charge trapping on them no matter what ΔE_t is, leading to lower driving voltage and higher efficiencies. This finding will be useful in any organic photonic devices such as phosphorescent or thermally assisted delayed fluorescent dye sensitized fluorescent OLEDs where trapping and recombination mechanisms play key roles.     

Effect of substituting CaO with BaO on the viscosity and structure of CaO‐BaO‐SiO2‐MgO‐Al2O3 slags

In this study, the effect of CaO and BaO substitution on the viscosity and structure of CaO‐BaO‐SiO₂‐MgO‐Al₂O₃ slags was investigated. The results showed that the viscosity increased with an increase in the BaO substitution concentration, which was correlated to an increase in the degree of polymerization (DOP) of the slag structural units as the activation energy increased from 207.9 to 263.8 kJ/mol for viscous flow. Deconvolution and area integration of the Raman spectrum of the slag revealed that the ratio of Q³/Q² (Qⁱ, i is the number of O⁰ in a [SiO₄]‐tetrahedral unit) increased and NBO/Si (nonbridging oxygen per unit silicon atom) decreased with higher BaO content. It was also observed from the ²⁷Al magic angles pinning nuclear magnetic resonance (²⁷Al MAS‐NMR) spectrum that the relative proportion of Al^IV increased, while that of Al^V decreased because of the decrease in the percentage of nonbridging oxygen (O^?), indicating the polymerization of the slag. O_1s X‐ray photoelectron spectroscopy (XPS) was also carried out to semi‐quantitatively analyze the various types of oxygen anions present in the slag. The XPS results correlated well with the results obtained from the analysis of the Raman and ²⁷Al MAS‐NMR spectra of the slags and its viscous behavior.     

An integrated numerical and experimental framework for modeling of CTB and GD1b ganglioside binding kinetics

A mathematical model is developed and validated for a multistep binding process between cholera toxin subunit B (CTB) and GD1b receptors that precedes cholera infection. To study the dynamics of the complex CTB‐GD1b binding mechanisms, cooperative binding effect and GD1b receptor aggregation in the host cell membrane are considered. More reliable parameters for the CTB‐GD1b binding kinetics are estimated by quantitatively calibrating the proposed multistep binding model against the experimental measurements obtained from the novel nanocube‐based biosensor. Specifically, a numerical scheme that includes the sensitivity analysis, parameter estimation and dynamic optimization is implemented for the model calibration. Through this scheme, identifiable model parameters are determined. After those selected parameters are estimated, the calibrated model and the experimental measurements were in reasonable agreement for different CTB and GD1b concentrations, which shows a promising approach for identification of the kinetics of CTB binding to the host cell membrane. © 2018 American Institute of Chemical Engineers AIChE J, 64: 3882–3893, 2018     

Optimal operation of batch enantiomer crystallization: From ternary diagrams to predictive control

In this work, the modeling and control of batch crystallization for racemic compound forming systems is addressed in a systematic fashion. Specifically, a batch crystallization process is considered for which the initial solution has been pre‐enriched in the desired enantiomer to enable crystallization of only the preferred enantiomer. A method for determining desired operating conditions (composition of the initial pre‐enriched solution and temperature to which the mixture must be cooled for maximum yield) for the batch crystallizer based on a ternary diagram for the enantiomer mixture in a solvent is described. Subsequently, it is shown that the information obtained from the ternary diagram, such as the maximum yield attainable from the process due to thermodynamics, can be used to formulate constraints for an optimization‐based control method to achieve desired product characteristics such as a desired yield. The proposed method is demonstrated for the batch crystallization of mandelic acid in a crystallizer with a fines trap that is seeded with crystals of the desired enantiomer. The process is controlled with an optimization‐based controller to minimize the ratio of the mass of crystals obtained from nuclei to the mass obtained from seeds while maintaining the desired enantioseparation. © 2017 American Institute of Chemical Engineers AIChE J, 64: 1618–1637, 2018     

Improved electrical and thermal conductivities of polysiloxane-derived silicon oxycarbide ceramics by barium addition

The electrical and thermal conductivities of bulk barium-added silicon oxycarbide (SiOC-Ba) ceramics are investigated. The SiOC-Ba ceramics exhibited improved electrical and thermal conductivities upon increasing the sintering temperature from 1450 °C to 1650 °C. Precipitation of graphitic carbon clusters observed by Raman spectroscopy and high-resolution transmission electron microscopy is attributed to the phase separation during the fabrication process. The increase in the electrical conductivity can be rationalized in terms of an increase in the density of the sp² CC bonds within the carbon clusters. The increase in the thermal conductivity is mainly attributed to the formation of interconnected graphitic clusters in the SiOC matrix and SiC embedded in the clusters. The electrical and thermal conductivities of the SiOC-Ba ceramics sintered at 1650 °C are 14.0 Ω^?1 cm^?1 and 5.6 W/m K, respectively, at room temperature. The electrical conductivity of SiOC-Ba sintered at 1550 °C is 5.3 Ω^?1 cm^?1 and 7.0 Ω^?1 cm^?1 at 2 and 300 K, respectively.