Effect of CuO on the Sintering Behavior and Dielectric Characteristics of Titanium Dioxide

The sintering behavior and dielectric characteristics of a titanium dioxide (TiO₂) were investigated by adding CuO. The addition of CuO lowered the sintering temperature of the TiO₂. At a given temperature, the densification and grain growth rate for a TiO₂ with CuO were enhanced, compared with those of pure TiO₂. The results suggest that CuO acts as an activator for the sintering of TiO₂. Dielectric constant and loss were also examined for both pure and CuO added TiO₂ samples. The variations of dielectric constant and loss were discussed in terms of grain size, porosity, and oxygen deficiency.     

Electrochromic device of PEDOT–PANI hybrid system for fast response and high optical contrast

An organic–organic hybrid system composed of the polyaniline (PANI) and poly-(3,4-ethylenedioxythiophene) (PEDOT) with controlled thickness was developed successfully in order to realize synergetic effects in electrochromic (EC) properties such as optical contrast and color-switching rate. From the UV transmittance spectra, we found that the optical contrast (Δ%T) was enhanced up to 6–72% at the wavelength of 580 nm compared with the previous PANI–PEDOT ECDs. Furthermore, the optimized ECD showed an extremely fast response time of less than 160 ms. It is therefore concluded that such a complementary full .cell system of PEDOT–PANI ECD is applicable as an optical device.     

Simultaneous amplification and channel equalization using Ramanamplifier for 30 channels in 1.3-μm band

A new technique is proposed to simultaneously amplify signals and equalize power unbalance caused by Raman-induced crosstalk among optical channels in the 1.3-μm band. The crosstalk is induced in GeO₂ -doped silica fibers due to the Raman-gain coefficient with a positive slope below the peak-frequency shift of 440 cm^-1. Highly doped GeO₂ silica fiber, however, shows a negative slope across the band between 440 cm^-1 and 490 cm^-1. We propose expansion of the Raman-gain band with a negative slope over the bandwidth of 150 cm^-1 using multiple pumps. Utilizing the negative gain slope of the proposed band, simultaneous amplification and power equalization was theoretically demonstrated for 30 channels in the 1.310-1.345 μm region without external filters     

Differential expression of genes associated with lipid metabolism in longissimus dorsi of Korean bulls and steers

The objective of this study was to compare expression of genes associated with lipid deposition and removal between bulls and steers in the longissimus dorsi muscle (LM) tissue of Korean cattle. Castration increased the expression of lipid uptake lipoprotein lipase, fatty acid translocase, and fatty acid transport protein 1 in LM. Castration increased lipogenic gene expression of both acetyl-CoA carboxylase and fatty acid synthase. In contrast, castration downregulated lipolytic gene expression of both adipose triglyceride lipase (ATGL) and monoglyceride lipase. Steers showed higher expression levels of insulin signaling phospho-v-akt murine thymoma viral oncogene homolog 1 than bulls but lower protein levels of nuclear Forkhead box O 1 (FoxO1) than bulls, suggesting that increased insulin signaling following castration decreases nuclear FoxO1 levels, leading to downregulation of ATGL gene expression. These findings suggest that castration contributes to increases in lipid uptake and lipogenesis and a decrease in lipolysis, resulting in improved marbling.     

Frequency analysis of a tower-cable coupled system

This study considers the prediction of natural frequency to avoid resonance in a wind turbine tower-cable coupled system. An analytical model based on the Rayleigh-Ritz method is proposed to predict the resonance frequency of a wind turbine tower structure supported by four guy cables. To verify the validity of the analytical model, a small tower-cable model is manufactured and tested. The frequency and mode data of the tower model are obtained by modal testing and finite element analysis. The validity of the proposed method is verified through the comparison of the frequency analysis results. Finally, using a parametric study with the analytical model, we identified how the cable tension and cable angle affect the resonance frequency of the wind turbine tower structure. From the analysis results, the tension limit and optimal angle of the cable are identified.     

Amorphous tungstate precursor route to nanostructured tungsten oxide film with electrochromic property

Electrochromic tungsten oxide (WO3) films on ITO glass were fabricated by spin-coating with a tungsten peroxy acid solution, which was prepared by adding an equivolume mixture of hydrogen peroxide and glacial acetic acid to tungsten metal powder. The structural evolution of the tungstate precursor upon heat treatment was studied by X-ray diffraction (XRD) and X-ray absorption near edge structure (XANES) analyses, which indicated that the as-synthesized tungstate transformed into nanocrystalline WO3 upon heating. It is, therefore, quite clear that as-synthesized tungstate can be a good precursor for electrochromic WO3 films. A series of WO3 thin films were prepared on ITO glass by spin-coating with different concentrations of tungsten peroxy acid solution and then post-annealing at various temperatures. Depending on the concentration of the tungstate coating solution (200-500 mg mL(-1)) and the annealing temperature (100-300 degrees C), the thickness and WO3 content as well as the electrochromic properties of WO3 films can be controlled. As a result, the optimum fabrication conditions were determined to be a tungstate solution concentration of 300-400 mg mL(-1) and a post-annealing temperature of 200 degrees C. Finally, an inorganic-inorganic hybrid electrochromic device (ECD) composed of optimized WO3 and Prussian Blue (PB) with desirable coloration efficiency was successfully developed.     

Alleviating effects of Opuntia ficus indica extracts on psychomotor alterations induced by ethanol in rats

Effects of Opuntia ficus indica (OFI) extracts on ethanol-induced psychomotor alterations were studied using Sprague-Dawley rats orally administered 4 g/kg of ethanol (EtOH group) or distilled water (control group). An OFI-group received OFI extracts (50, 100, and 200 mg/kg) 30 min prior to EtOH administration. Behavioral and hematological tests were evaluated 1, 2, 4, and 8 h after EtOH administration. Electroencephalogram (EEG) assessment was also performed. EtOH significantly (p<0.001) induced psychomotor alterations (reduced locomotion, balance, coordination, muscle strength, and tolerance to cold), compared with control group rats. Pre-treatment with OFI extracts alleviated alterations and also inhibited elevation of blood ethanol levels. EEG (percent of total power for delta, theta, alpha, and beta) results for OFI group rats were similar to control rats, indicating a countering of EtOHinduced EEG changes. Extracts of OFI can be effective for alleviation of psychomotor alterations induced by EtOH administration.     

Subcontractor Evaluation and Management Framework for Strategic Partnering

Recently, main contractors have shifted their attitudes about subcontract procurement to more strategic and long-term partnering philosophies. The objective of this study was to present a framework for subcontractor evaluation and management to help main contractors develop more strategic and productive relationships with their subcontract partners. As the strategic performance feedback model, the balanced scorecard concept was adopted with modification. A case study was also conducted to evaluate the framework with subcontracting strategy, performance indexes, weighting, evaluation of subcontractor performance data, and feedback methods. The research results obtained can be useful as a guideline of subcontractor management for long-term partnering and also to enhance overall productivity within the construction supply chain.     

Resonance peak shift and dual peak separation of long-period fibergratings for sensing applications

The systematic analysis of the relationship among the transmission characteristics of long-period fiber gratings, the initial coupling strength, and the fluence of the postexposure UV beam are discussed. The UV postexposure allows for adjustment of the peak depth depending on the initial coupling strength while red-shifting the resonance wavelength. Dual peak separation can occur for high-order cladding modes, and its application to sensing of the bending curvature, transverse load, and external refractive index are described     

Monitoring civil structures with a wireless sensor network

Structural health monitoring (SHM) is an active area of research devoted to systems that can autonomously and proactively assess the structural integrity of bridges, buildings, and aerospace vehicles. Recent technological advances promise the eventual ability to cover a large civil structure with low-cost wireless sensors that can continuously monitor a building's structural health, but researchers face several obstacles to reaching this goal, including high data-rate, data-fidelity, and time-synchronization requirements. This article describes two systems the authors recently deployed in real-world structures.