• Journal of Food Hygiene and Safety
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• v.36 no.5
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• pp.376-381
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• 2021

Red beet (Beta vulgaris L.) is a root vegetable and a popular functional food ingredient of dark red-purple appearance due largely to betacyanins, principally betanine (75-95%) and its isomer, isobetanine (15-45%). This study developed an analytical method for beet red in terms of betanine and isobetanine in processed food products labeled with beet red as a food additive. High Performance Liquid Chromatography-Diode Array Detector (HPLC-DAD) was used with a C₁₈ column. Linearity, limit of detection (LOD), limit of quantitation (LOQ), accuracy, precision and uncertainty in measurement were calculated for method validation. Matrix-matched calibration was applied to the candy, ice cream, and cocoa product, respectively, and R² was ≥0.9998, showing a high level of linearity. The LOD and LOQ were 0.16 to 0.32 and 0.48 to 0.97 mg/L, respectively. As a result of repeated intra-day and interday experiments to validate the accuracy and precision of the analytical method, the recovery rates were 96.0-103.1% and 100.0-102.2%, respectively and the RSD% was 0.5-3.3% and 0.9-3.8%, respectively. Moreover, the measurement uncertainty was estimated to be 1.71-12.43% depending on the matrix and the measured concentration. In this study, betanine and isobetanine were quantified (8.4-3,823.4 mg/kg) by applying the developed analytical method to processed food products (n= 26; e.g., candy, ice cream, and other processed foods) labeled with beet red as a food additive.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.2
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• pp.445-454
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• 1991

In this thesis, Mindlin plate element with nine nodes and three degrees-of-freedom at each node is formulated and is employed in eigen-analysis of a rectangular plates in order to alleviate locking phenomenon of eigenvalues. Eigenvalues and their modes may be locked if conventional $C_{0}$-isoparametric element is used. In order to reduce stiffness locking phenomenon, two methods (1, the general reduced and selective integration, 2, the new element that use of modified shape function) are studied. Additionally in order to reduce the error due to mass matrix, two mass matrixes (1, Gauss-Legendre mass matrix, 2, Gauss-Lobatto mass matrix) are considered. The results of eigen-analysis for two models (the square plate with all edges simply-supported and all edges built-in), computed by two methods for stiffness matrix and by two mass matrixes are compared with theoretical solutions and conventional numerical solutions. These comparisons show that the performance of the two methods with Gauss-Lobatto mass matrix is better than that of the conventional plate element. But, by considering the spurious rigid body motions, the element which employs modified shape function with full integration and Gauss-Lobatto mass matrix can elevate the accuracy and convergence of numerical solutions.

• Nutrition Research and Practice
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• v.10 no.6
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• pp.569-574
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• 2016

BACKGROUND/OBJECTIVES: We investigated the anti-osteoarthritic effects of deer bone extract on the gene expressions of matrix metalloproteinases (MMPs) and collagen type II (COL2) in interleukin-$1{\beta}$-induced osteoarthritis (OA) chondrocytes. MATERIALS/METHODS: Primary rabbit chondrocytes were treated as follows: CON (PBS treatment), NC (IL-$1{\beta}$ treatment), PC (IL-$1{\beta}+100{\mu}g/mL$ glucosamine sulphate/chondroitin sulphate mixture), and DB (IL-$1{\beta}+100{\mu}g/mL$ deer bone extract). RESULTS: The results of the cell viability assay indicated that deer bone extract at doses ranging from 100 to $500{\mu}g/mL$ inhibits cell death in chondrocytes induced by IL-$1{\beta}$. Deer bone extract was able to significantly recover the mRNA expression of COL2 that was down-regulated by IL-$1{\beta}$ (NC: 0.79 vs. DB: 0.87, P < 0.05) and significantly decrease the mRNA expression of MMP-3 (NC: 2.24 vs. DB: 1.75) and -13 (NC: 1.28 vs. DB: 0.89) in OA chondrocytes (P < 0.05).CONCLUSIONS: We concluded that deer bone extract induces accumulation of COL2 through the down-regulation of MMPs in IL-$1{\beta}$-induced OA chondrocytes. Our results suggest that deer bone extract, which contains various components related to OA, including chondroitin sulphate, may possess anti-osteoarthritic properties and be of value in inhibiting the pathogenesis of OA.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.9
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• pp.685-691
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• 2003

This work describes a 3 V 12b 100 MS/s CMOS digital-to-analog converter (DAC) for high-speed communication system applications. The proposed DAC is composed of a unit current-cell matrix for 8 MSBs and a binary-weighted array for 4 LSBs, considering linearity, power consumption, chip area, and glitch energy. The low-glitch switch driving circuit is employed to improve the linearity and the dynamic performance. Current sources of the DAC are laid out separately from the current-cell switch matrix core. The prototype DAC is implemented in a 0.35 urn n-well single-poly quad-metal CMOS technology. The measured DNL and INL of the prototype DAC are within $\pm$0.75 LSB and $\pm$1.73 LSB, respectively, and the spurious-free dynamic range (SFDR) is 64 dB at 100 MS/s with a 10 MHz input sinewave. The DAC dissipates 91 mW at 3 V and occupies the active die area of 2.2 mm ${\times}$ 2.0 mm.

• Membrane Journal
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• v.33 no.1
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• pp.23-33
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• 2023

In this study, a mixed matrix membrane was prepared by varying the contents of PEI-GO@ZIF-8 synthesized in PEBAX 2533, and the permeation characteristics of N₂ and CO₂ were studied. The N₂ permeability of the PEBAX/PEIGO@ZIF-8 mixed matrix membrane decreased as the PEI-GO@ZIF-8 content increased, and the CO₂ permeability showed different trends depending on the PEI-GO@ZIF-8 content. The CO₂ permeability increased in pure PEBAX membrane up to PEBAX/PEI-GO@ZIF-8 0.1 wt%, but decreased at the subsequent content. The PEI-GO@ZIF-8 0.1 wt% mixed matrix membrane had a CO₂ permeability of 221.9 Barrer and a CO₂/N₂ selectivity of 60.0, showing the highest permeation properties with improved CO₂ permeability and CO₂/N₂ selectivity among the prepared mixed matrix membrane and we obtained a result that reached the Robeson upper-bound. This is due to the -COOH, -O-, and -OH functional groups of GO and the amine group bonded to PEI, which interact friendly with CO₂, and the effect of ZIF-8, which causes gate-opening for CO₂ while the fillers are evenly dispersed in PEBAX.

• Preventive Nutrition and Food Science
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• v.16 no.4
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• pp.291-298
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• 2011

Yam extracts (Dioscorea batatas) have been reported to possess a variety of functions. However, studies on its osteogenic properties are limited. In this study, we investigated the effect of ethanol and water extracts on osteoblast proliferation and bone matrix protein synthesis, type I collagen and alkaline phosphatase (ALP), using osteoblastic MC3T3-E1 cell model. MC3T3-E1 cells were cultured with yam ethanol and water extracts (0~30 mg/L) within 39 days of osteoblast differentiation period. Cell proliferation was measured by MTT assay. Bone matrix proteins were assessed by the accumulation of type I collagen and ALP activity by staining the cell layers for matrix staining. Also, the secreted (media) matrix protein concentration (type I collagen) and enzyme activity (ALP) were measured colorimetrically. Yam ethanol and water extracts stimulated cell proliferation within the range of 15~30 mg/L at 15 day treatment. The accumulation of type I collagen in the extracellular matrix, as well as secreted collagen in the media, increased with increasing doses of yam ethanol (3~15 mg/L) and water (3~30 mg/L) extracts. ALP activity was not affected by yam ethanol extracts. Our results demonstrated that yam extracts stimulated osteoblast proliferation and enhanced the accumulation of the collagenous bone matrix protein type I collagen in the extracellular matrix. These results suggest that yam extracts may be a potential activator for bone formation by increasing osteoblast proliferation and increasing bone matrix protein type I collagen. Before confirming the osteogenic action of yam, further studies for clarifying how and whereby yam extracts can stimulate this ostegenesis action are required.

• Journal of the Korean institute of surface engineering
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• v.26 no.6
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• pp.299-306
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• 1993

The characteristic of synthesized potassium hexatitanate and manufacturing of thin film type matrix for battery was studied. After ball milled the mixture with 1:4 of $K_2CO_3$ and TiO2, mixsture was sintered at 85$0^{\circ}C$ and its product was confirmed with XRD. Adding the PTFE to the obtained potassium hexatitanate according to there various ball-mill time to control its particle size, thin film type matrix was manufactured. The high-est wettability of 50% was found with 12 hour ball milled powder containing 10w/o of PTFE and also it shown good mechanical properties. The matrix with $K_2O$$\cdot$$6TiO_2$ whisker shown 170% of wettability. Thed char-acteristics of matrix made by whisker and powder mixture were compared with the investigation of bubbled pressure and pore size distribution to improve its mechanical properties.

• Membrane Journal
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• v.26 no.6
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• pp.463-469
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• 2016

In this research, a new expectation in enhancing the PES (polyethersulfone) polymer phase inversion membrane performances with nanoparticles is proposed by using ZnO. This paper investigated the synthesis of PES phase inversion membranes including ZnO nanoparticles and evaluates the performance of these mixed matrix membranes. The PES-ZnO mixed matrix membranes were fabricated by phase inversion method using the PES-ZnO-NMP(N-methyl-1-pyrrolidone) casting solutions with low ZnO nanoparticles content of 0.375 wt%. The influence of ZnO nanoparticles on the characteristics of PES-ZnO mixed matrix membranes was investigated with scanning electron microscope observations of membrane cross-sections, contact angle measurements, tensile strength measurements, pure water flux measurements and ultrafiltration experiments of BSA solution. Those results showed that the performance advancements in comparison with the pure PES membrane without ZnO in terms of increasing hydrophilicity as well as reducing membrane fouling by adding ZnO nanoparticles even in low concentration.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.06a
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• pp.243-246
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• 1998

This paper presents a 6-bit self-calibrated D/A converter designed with current cell matrix structure. This structure is based on the current-cell matrix configuration using a regulated gate cascode current cell with 3-way switch. using from CMOS process and 5V power supply, the simulated conversion rate is 45.78MHz and the average mismatching properties among current sources are reduced to 0.02% and 0.005%, respectively when 1% and 0.5% errors of current sources are considered.

• Mass Spectrometry Letters
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• v.8 no.1
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• pp.8-13
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• 2017

Analysis of quinidine for fish tissues using single drop microextraction (SDME) coupled with atmospheric pressure matrix assisted laser desorption/ionization mass spectrometry (AP-MALDI-MS) are reported. Optimization conditions; such as extraction solvent, extraction time, pH of the aqueous solution, salt additions (NaCl), stirring rate, matrix type and concentration are investigated. Linear dynamic range (${\mu}M$), limit of detection, relative recovery%, and enrichment factor are 0.08-9.2, 0.05, $94.8{\pm}3.1-98.5{\pm}3.3%$, $4.34{\pm}0.28-4.40{\pm}0.30$, respectively. SDME-AP-MALDI-MS shows good intraday and interday reproducibility.