Highly Customizable All Solution–Processed Polymer Light Emitting Diodes with Inkjet Printed Ag and Transfer Printed Conductive Polymer Electrodes

Inkjet and transfer printing processes are combined to easily form patterned poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) films as top anodes of all solution–processed inverted polymer light emitting diodes (PLEDs) on rigid glass and flexible plastic substrates. An adhesive PEDOT:PSS ink is formulated and fully customizable patterns are obtained using the inkjet printing process. In order to transfer the patterned PEDOT:PSS films, adhesion properties at interfaces during multistep transfer printing processes are carefully adjusted. The transferred PEDOT:PSS film on the plastic substrates shows not only a sheet resistance of 260.6 Ω/□ and a transmittance of 92.1% at 550 nm wavelength but also excellent mechanical flexibility. The PLEDs with spin‐coated functional layers sandwiched between the transferred PEDOT:PSS top anodes and inkjet‐printed Ag bottom cathodes are fabricated. The fabricated PLEDs on the plastic substrates show a high current efficiency of 10.4 cd A^?1 and high mechanical stability. It is noted that because both Ag and PEDOT:PSS electrodes can be patterned with a high degree of freedom via the inkjet printing process, highly customizable PLEDs with various pattern sizes and shapes are demonstrated on the glass and plastic substrates. Finally, with all solution process, a 5 × 7 passive matrix PLED array is demonstrated.     

Routing Protocol for Heterogeneous Hierarchical Wireless Multimedia Sensor Networks

Recently, wireless multimedia sensor networks (WMSNs) have emerged as one of the most important technologies, driven by the development of powerful multimedia device such as CMOS. WMSNs require several factors such as resource constraints, specific QoS, high bandwidth and so on. In this paper, we propose a hierarchical heterogeneous network model based routing protocol for WMSNs. In our proposal, proposed network model is classified into monitoring class, delivery class and aggregation class. Also we define two kinds of the routing path in order to ensure bandwidth and QoS. In simulation results, we illustrate the performance of our proposal.     

Extraction of interface states at emitter–base heterojunctions in AlGaAs/GaAs heterostructure bipolar transistors using sub-bandgap photonic excitation

Distribution of interface states at the emitter–base heterojunctions in heterostructure bipolar transistors (HBTs) is characterized by using current–voltage characteristics using sub-bandgap photonic excitation. Sub-bandgap photonic source with a photon energy E_ph which is less than the energy bandgap E_g (E_g,GaAs = 1.42, E_g,AlGaAs = 1.76 eV) of emitter, base, and collector of HBTs, is employed for exclusive excitation of carriers only from the interface states in the photo-responsive energy range at emitter–base heterointerface. The proposed method is applied to an Al_0.3Ga_0.7As/GaAs HBT (A_E = W_E × L_E = 250 × 100 μm²) with E_ph = 0.943 eV and P_opt = 3 mW. Extracted interface trap density D_it was observed to be D_it,max  4.2 × 10¹² eV⁻¹ cm⁻² at emitter–base heterointerface.     

Environment Adaptive Localization Method Using Wi-Fi and Bluetooth Low Energy

Received signal strength indicator (RSSI) based fingerprinting techniques for indoor positioning can be readily implemented via a wireless access point. These methods have therefore been widely studied in the field of positioning. However, fingerprinting suffers low accuracy of positioning on account of high noise occurrences which are caused by other wireless communication signals and environmental factors when the RSSI is received, and by relatively high errors on account of low position resolution compared to other methods such as time of flight and inertial navigation technology. In this paper, a modified fingerprint algorithm based on Wi-Fi and Bluetooth low energy applied to the log-distance path loss model is proposed to remove unnecessary Wi-Fi data, and produce the AP database that can be updated depending on the changes of the ambient environment as the indoor area is increasingly complicated and extended. Instead of using the existing fingerprinting techniques of consulting signal strengths as factors that are stored in a database, the proposed algorithm employs environmental variables to which the log-distance path loss model is applied. Therefore, the proposed algorithm has higher position resolution than existing fingerprint and can improve the accuracy of positioning because of its low dependence on reference points. To minimize database and eliminate inaccurate AP signals, the Hausdorff distance algorithm and median filter are applied. Using a database in which environment variables are stored, the results are inversely transformed into the log-distance path loss model for expression as coordinates. The proposed algorithm was compared with existing fingerprinting methods. The experimental results demonstrated the reduction of positioning improvement by 0.695 m from 2.758 to 2.063 m.     

Cyanidin-3-glucoside ameliorates CCl4-induced liver injury in mice

The protective effect of cyanidin-3-glucoside (C3G) against carbon tetrachloride (CCl₄)-induced liver injury in mice was investigated. Administration of C3G attenuated the levels of serum aspartate aminotransferase, alanine aminotransferase, and liver lipid peroxidation in CCl₄-treated mice. Histopathological examination of mouse livers showed that C3G reduced the incidence of liver lesions induced by CCl₄. Moreover, C3G prevented DNA damage and decreased the protein levels of γ-H2AX in CCl₄-treated mouse livers. C3G also increased the activity of the antioxidant enzymes superoxide dismutase, catalase, glutathione peroxidase, and glutathione reductase, which were decreased due to CCl₄ administration in CCl₄-treated mouse livers. C3G inhibited the expression levels of IL-6 and iNOS in CCl₄-treated mice. C3G apparently protects the liver from CCl₄-induced hepatic damage through antioxidant and anti-inflammatory mechanisms.     

Antioxidant effect of grapevine leaf extract on the oxidative stress induced by a high-fat diet in rats

This study was conducted to investigate the effect of grapevine leaf extract (GLE) on the oxidative stress of rats fed a high-fat diet. Rats were divided into six groups: a normal diet with 0% (NC), 1.0% (NG1.0), and 1.5% GLE (NG1.5); and a high-fat diet with 0% (HFC), 1.0% (HFG1.0), and 1.5% GLE (HFG1.5). Treatment with GLE to the high-fat diet reduced lipid peroxide concentrations in plasma and liver compared to those of HFC rats. Total glutathione and GSH/GSSG of the groups with GLE were higher than those of untreated groups. Hepatic glutathione peroxidase, glutathione-S-transferase, and glutathione reductase activities along with catalase and glutathione peroxidase activities in erythrocytes increased after GLE treatment to high-fat diet compared with HFC rats. Hepatic retinol and tocopherol increased in HFG1.5 group compared to those of HFC group. These results indicate that GLE can protect against oxidative stress induced by a high-fat diet in rats.     

Effect of grain size and density of spray-pyrolyzed hydroxyapatite particles on the sinterability of hydroxyapatite disk

The effect of grain size and density of hydroxyapatite particles, which were prepared by different spray-pyrolysis temperatures, on the sinterability of hydroxyapatite disk was investigated. Calcium phosphate solution (Ca/P ratio of 1.67 and 0.1 M concentration) was prepared by reacting calcium nitrate tetrahydrate and diammonium hydrogen phosphate solutions, and adding nitric acid. Spray-pyrolysis was carried out at 900 °C, 1200 °C, and 1500 °C at a carrier gas flowing rate of 10 L/min. The particles synthesized at 900 °C were large, hollow spheres with a hole at the outer surface, a broad size distribution, but had small grain sizes. Conversely, the particles synthesized at 1500 °C were small, solid spheres with a narrow size distribution, but had large grain sizes. The particles synthesized at 1200 °C had intermediate properties. A sinterability test conducted at 1100 °C for 1 h demonstrated that small and dense particles with large grain sizes showed a higher relative sintered density compared with large and hollow particles with small grain sizes. The results were explained in terms of the grain size and density of a particle, which were inversely and proportionally affected to sinterability. The practical implication of these results is that highly sinterable hydroxyapatite powders can be synthesized through spray-pyrolysis at a high temperature under a fixed initial concentration of calcium phosphate solution and flow rate of carrier gas.     

Utilisation possibility of Enterococcus faecalis isolates from neonate's faeces for production of fermented sausages as starter cultures

This study aimed at assessing the utilisation possibility of Enterococcus faecalis as starter cultures for production of fermented sausages. The E. faecalis isolates isolated from faeces samples of 5‐day‐old healthy newborn babies, identified by 16SrDNA sequencing and free from virulence determinants as proven by genomic sequencing, were used for fermented sausages production as starter culture. Six treatments (four inoculated with four different E. faecalis isolates, one with commercial starter culture and one control) were prepared. The inoculation with E. faecalis showed a stronger acidification compared with the control. The treatments with E. faecalis showed significantly higher flavour and acceptability scores in comparison with the control or commercial starter culture. Both of commercial starter culture and E. faecalis were positive with tyramine. Apart from the amine production, the inoculation with E. faecalis generally improved the acidifying activity and flavour of the products, suggesting their application potentials in fermented sausages production as starter cultures.     

Measurement of residual stress using linearly integrated GMR sensor arrays

Tubular-type transmission towers have several advantages, but could be compromised if welding defects from the construction process are not found during deployment. This research derived an equation that illustrates how a change in stress accompanied with mechanical deformation triggered a change in distribution of magnetic flux density. Furthermore, it verified experimentally that a change in distribution of magnetic flux density occurred due to a change in stress at the welding zone. Using this principle, this research proposes a system to measure residual stress occurred in the welding zone of tubular-type transmission tower. The ultrasound examination results were compared and the result showed that ultrasound signals revealed defects in a place where sudden distribution of magnetic flux density was presented. However, when a number of welding defects occurred across the large area, the distribution of magnetic flux density may not change due to the alleviating effect of the stress concentration.     

Cyclometalated iridium(III) complexes with 5-acetyl-2-phenypyridine derived ligands for red phosphorescent OLEDs

A series of new iridium complexes with 5-acetyl-2-phenylpyridine derivatives as ligands was developed. The complexes exhibited high EL performance when applied to OLEDs. These materials showed red emission with a peak at 575–636 nm. In particular, one of the devices in this study showed a maximum luminous efficiency, maximum power efficiency, external quantum efficiency and CIE coordinates of 29.0 cd/A, 6.13 lm/W, 8.86% at 20 mA/cm² and (0.57, 0.43) at 10 V, respectively. In addition, a deep red OLED with CIE coordinates of (0.67, 0.32) at 10 V exhibited a maximum luminous efficiency, maximum power efficiency and external quantum efficiency of 5.61 cd/A, 1.02 lm/W and 5.35% at 20 mA/cm², respectively.