Effect of dietary patterns on the blood/urine concentration of the selected toxic metals (Cd,Hg, Pb) in Korean children

Food Science and Biotechnology - This study was aimed to examine the association the blood/urinary concentration of toxic metal (Hg, Pb, and Cd) with children’s dietary patterns. This...     

Ultra-sensitive Transition-Edge Sensors for the Background Limited Infrared/Sub-mm Spectrograph (BLISS)

We report progress in fabricating ultra-sensitive superconducting transition-edge sensors (TESs) for BLISS. BLISS is a suite of grating spectrometers covering 35–433?μm with R～700 cooled to 50?mK that is proposed to fly on the Japanese space telescope SPICA. The detector arrays for BLISS are TES bolometers readout with a time domain SQUID multiplexer. The required noise equivalent power (NEP) for BLISS is NEP=10^?19?W/Hz^1/2 with an ultimate goal of NEP=5×10^?20?W/Hz^1/2 to achieve background limited noise performance. The required and goal response times are τ=150?ms and τ=50?ms respectively to achieve the NEP at the required and goal optical chop frequency 1–5?Hz. We measured prototype BLISS arrays and have achieved NEP=6×10^?18?W/Hz^1/2 and τ=1.4?ms with a Ti TES (T _C=565?mK) and NEP～2.5×10^?19?W/Hz^1/2 and τ～4.5?ms with an Ir TES (T _C=130?mK). Dark power for these tests is estimated at 1–5?fW.     

A method to reduce the flow depth of a plate heat exchanger without a loss of heat transfer performance

With the aim of improving heat exchanger compactness, this study investigates how the optimum configuration of an air–liquid plate heat exchanger changes as the heat exchanger depth decreases. In this respect, optimization of an air–liquid plate heat exchanger with a given frontal area and a given depth is achieved. The optimum fin pitch and plate pitch are obtained to maximize the heat transfer rate based on heat transfer and pressure loss correlations in finned channels. Then, the focus of this study is placed on how the optimum channel configuration changes when the heat exchanger depth decreases for compactness. The results illustrate that the heat transfer performance can remain unchanged if the geometric parameters, such as the plate thickness, the plate pitch, the fin thickness, and the fin pitch, are reduced proportionally to the square root of the flow depth reduction given that the flow remains laminar. This finding is arranged into a simple scaling rule to obtain the configuration of a more compact heat exchanger from an existing configuration. In addition, the scaling arguments are extended to practical situations where the fin thickness and the plate thickness are not properly reduced following the scaling rule due to limitations on available material thicknesses.     

Nanoscale patterning of colloidal quantum dots on transparent and metallic planar surfaces

The patterning of colloidal quantum dots with nanometer resolution is essential for their application in photonics and plasmonics. Several patterning approaches, such as the use of polymer composites, molecular lock-and-key methods, inkjet printing and microcontact printing of quantum dots have been recently developed. Herein, we present a simple method of patterning colloidal quantum dots for photonic nanostructures such as straight lines, rings and dot patterns either on transparent or metallic substrates. Sub-10?nm width of the patterned line could be achieved with a well-defined sidewall profile. Using this method, we demonstrate a surface plasmon launcher from a quantum dot cluster in the visible spectrum.     

Trends in passenger transport energy use in South Korea

Having a clear understanding of transport energy use trends is crucial to identifying opportunities and challenges for efficient energy use for the transport sector. To this date, however, no detailed analysis has been conducted with regard to rapidly growing passenger transport energy use in South Korea. Using bottom-up data developed from a variety of recent sources, we described the trends of transport activity, energy use, and CO₂ emissions from South Korea’s transport sector since 1986 with a particular focus on its passenger transport. By decomposing the trends in passenger transport energy use into activity, modal structure, and energy intensity, we showed that while travel activity has been the major driver of the increase in passenger transport energy use in South Korea, the increase was to some extent offset by the recent favorable structural shift toward bus travel and away from car travel. We also demonstrated that while bus travel has become less energy intensive since the Asian Financial Crisis, car travel has become increasingly energy intensive.     

Corrosion-resistant coating for cathode current collector and wet-seal area of molten carbonate fuel cells

High-temperature corrosion of metallic bipolar plates is a main problem to limit system reliability of molten carbonate fuel cells (MCFCs). In particular, cathode current collector (CCC) and wet-seal area in the bipolar plates suffer severe corrosion during MCFCs operation. Herein, we are trying to explore facile and cost-effective coating materials and methods to enhance corrosion resistance of CCC and wet-seal area of MCFCs. Cobalt (Co) layer was coated by using electrodeposition method for CCC, and aluminum (Al) layer was coated by using mechanical cladding method for wet-seal area. Co and Al layers were transformed into in-situ lithiated oxides, which are LiCoO₂ and LiAlO₂, by reacting with electrolytes without detachment. These in-situ formed oxides efficiently impede formation and growth of corrosion scales by preventing permeation of electrolytes. We believe that Co electrodeposition and Al cladding would be suitable and practical methods for making protective layers to enhance corrosion resistance of CCC and wet-seal area in the MCFCs bipolar plates.     

Correlation of eddy current responses between fatigue cracks and electrical-discharge-machining notches

The eddy current responses of Electrical Discharge Machining (EDM) notches and fatigue cracks are directly compared to verify the reliability of eddy current inspection. The fatigue crack growth tests using a constant load range control mode were conducted to obtain a variety of edge crack sizes, ranging from 0.9 to 6.6 mm for Al alloy and from 0.1 to 3 mm for Ti alloy. EDM notch specimens of Al and Ti alloys were accordingly prepared in lengths similar to that of the fatigued specimen. The crack length was determined by optical microscope and scanning electron microscope. The eddy current responses between the EDM and fatigued specimens with varying notch/crack length were examined using probe sensors at (100-500) kHz and (1-2) MHz for Al and Ti alloys, respectively. The results show a significant difference in the eddy current signal between the two specimens, based on the correlation between the eddy current response and notch/crack length. This suggests that eddy current inspection using the EDM reference specimen is inaccurate in determining the precise crack size, unless the eddy current response data base is obtained from a fatigue-cracked specimen.     

In vitro anti-obesity effects of sesamol mediated by adenosine monophosphate-activated protein kinase and mitogen-activated protein kinase signaling in 3T3-L1 cells

Food Science and Biotechnology - Sesamol is a phenol derivative of sesame oil and a potent anti-oxidant, anti-inflammatory, anti-hepatotoxic, and anti-aging compound. We investigated the effects of...     

Short communication: Antioxidative and antibacterial activities on Staphylococcus aureus and Escherichia coli O157:H4 in milk with added ginseng marc extract fermented by Lactobacillus plantarum KCCM 11613P

Ginseng marc, a by-product of the extraction of fresh ginseng, is known to have bioactive compounds, but is frequently discarded as agriculture waste. The objectives of our study were to assess the antioxidative activity of fermented ginseng marc extract using Lactobacillus plantarum KCCM 11613P and to evaluate antibacterial activity of fermented milk with added ginseng marc extract during fermentation. After 24 h of fermentation of ginseng marc extract, the viable cell number was increased to 7.7 ± 0.1 log cfu/mL, and the pH and total titratable acidity were 4.2 ± 0.4 and 0.6% lactic acid, respectively. The total phenolic and flavonoid contents of fermented ginseng marc extract increased by 32.4 and 23.3%, respectively. Higher antioxidative activity of fermented ginseng marc extract was obtained in the β-carotene bleaching, ferric-reducing ability of plasma, and ferric thiocyanate assays than the 1,1-diphenyl-2-picrylhydrazy assay. However, the 1,1-diphenyl-2-picrylhydrazy scavenging effect decreased due to lowered pH. During production of fermented milk with ginseng, inhibition rate of Staphylococcus aureus and Escherichia coli were 9.7 and 2.3%, respectively. The present study shows the possibilities of Lactobacillus plantarum KCCM 11613P used as a fermentation strain and ginseng marc used as a functional supplement in milk.     

Epitaxial integration of perovskite-based multifunctional oxides on silicon

We review recent developments in the epitaxial integration of multifunctional oxide thin film heterostructures on silicon (Si). Perovskite oxides have been extensively studied for use in multifunctional devices due to a wide range of functional properties. To realize multifunctional oxide devices, these multifunctional films should be integrated directly on Si, maintaining high crystalline quality. Molecular beam epitaxy growth of epitaxial SrTiO₃ (STO) on Si provides a template for incorporating the epitaxial oxide films on Si. However, the dissimilar physical nature of Si from most oxide materials influences the properties of oxide films on Si, especially with regard to structural defects and thermal strains. Therefore, in this review, we present a comprehensive overview of epitaxial integration of various model oxide systems on Si, addressing how STO/Si can be used to explore the novel phenomenon of oxide heterostructures as well as to realize multifunctional devices.