• Applied Chemistry for Engineering
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• v.29 no.1
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• pp.97-102
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• 2018

In this work, the surface of gold nanoparticles (AuNPs) was modified with small molecules including mercaptoundecanoic acid (MUA) and L-lysine for the development of highly sensitive lateral flow (LF) sensors. Uniformly sized AuNps were synthesized by a modified Turkevich-Frens method, showing an average size of $16.7{\pm}2.1nm$. Functionalized AuNPs were then characterized by transmission electron microscopy, UV-vis spectroscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. The stable conjugation of AuNPs and antibodies was obtained at pH 7.07 and the antibody concentration of $10{\mu}g/mL$. The functionalized AuNP-based LF sensor exhibited lower detection limit of 10 ng/mL for hepatitis B surface antigens than that of using the bare AuNP-based LF sensor (100 ng/mL).

• Korean Journal of Pharmacognosy
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• v.47 no.1
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• pp.79-83
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• 2016

This study developed an HPLC analysis method for the determination of isoegomaketone (IK) and perillaketone (PK) in Perilla frutescens (L.) Britton leaves. P. frutescens ethanol extract was optimized through an HPLC analysis using a C18 column ($250{\times}4.6mml$, D, $S-5{\mu}m$, 12 nm) with gradient elution of water and acetonitrile as the mobile phase at a flow rate of 1 mL/min and a UV detection wavelength of 254 nm. The results of this method showed linearity in the calibration curve at a coefficient of correlation ($R^2$) of IK 0.9995, PK 0.9998. The limits of detection (LOD) for IK and PK were $0.234{\mu}g/mL$ and $0.952{\mu}g/mL$. The limits of quantification (LOQ) for IK and PK were $0.017{\mu}g/mL$ and $0.043{\mu}g/mL$. The inter-day precision RSDs of IK and PK in the P. frutescens were 1.25 to 2.69% and 0.36 to 1.10%, respectively, and the intra-day precision RSDs of IK and PK were 0.96 to 2.51% and 0.90 to 1.93%, respectively. The accuracies of IK and PK were 96.31 to 97.92% and 101.26 to 105.14%. In conclusion, this method was applied successfully to the detection of IK and PK in P. frutescens.

• Korean Journal of Environmental Agriculture
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• v.17 no.3
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• pp.268-273
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• 1998

Changes of chemical component and losses of chemical fertilizer by infiltration water from 0.5ha of paddy field in Chinan area of Chonbuk province during the rice cultivation were investigated. The infiltration water samples were collected in a ceramic porous cup which was a buried at the 30, 50, 70, 90㎝ of soil depth. pH of infiltration water ranged $6.64{\sim}7.90$ and EC showed $324{\sim}647{\mu}$S/cm. The content of total-N, $NH_4-N$ and $NO_3-N$ were $0.58{\sim}14.59$, $0.05{\sim}4.25$, and $0.15{\sim}7.71mg/L$ respectively. The content of total-P and ortho-P were $0.009{\sim}0.077mg/L$ and $0{\sim}0.029mg/L$ The content of $Ca^{++}$, $Mg^{++}$, $Na^{+}$ and $K^{+}$ showed $0.88{\sim}4.78$, $0.22{\sim}1.04$, $0.17{\sim}0.98$, and $0.84{\sim}3.19㎎/L$. These all at the first transplanting are higher than that of other periods. The content of $SO_4^{2-}$ showed $3.92{\sim}18.72mg/L$ and decreased with a soil depth. However $Cl^-$ of infiltration water ranged $9.03{\sim}19.97mg/L$ and no difference with a soil depth. When infiltrated $2,416.5m^{3}$ of an infiltration water from 0.5ha of paddy field during the rice cultivation, losses of chemical components were 20.34㎏/㏊ of total-N, 3.54㎏/㏊ of $NH_4-N$, 10.44㎏/㏊ of $NO_3-N$, 0.16㎏/㏊ of total-P and 0.028㎏/㏊ of ortho-P. Also $Ca^{++}$, $Mg^{++}$, $Na^+$, $K^+$, $SO_4^{2-}$ and $Cl^-$ were lost 10.24, 2.84, 2.84, 7.22, 50.04 and 62.20㎏/㏊ respectively. There were lost by infiltration water 9.35% of nitrogen, 0.59% of phosphorous and 22.79% of potassium in applied chemical fertilizer.

• Bulletin of the Korean Chemical Society
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• v.31 no.8
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• pp.2322-2328
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• 2010

A multiple solid-phase extraction (SPE) method was used with liquid chromatography, coupled with mass spectrometry (LC/MS), for the analysis of heterocyclic amines (HCAs) in human urine. Separation efficiencies based on the pH of the mobile phase and the types of columns were compared. An amide column showed better baseline separation and narrower HCA peak widths at pH 5.0 for the mobile phase than a $C_8$ column. Each SPE step, HLB, MCX, and HybridSPE, was optimized by controlling the pH conditions. The combined method with the three SPEs effectively removed interfering species that cause ion-suppression during HCA detection. Validation of the method, performed with SIM and SRM detection, showed correlation coefficients above 0.991 in the range 0.3 - 16.7 ng/mL. Recovery rates were 45.4 - 97.3% on the $C_8$ column and 71.8 - 101.4% on the amide column, and method detection limits were 0.11 - 0.65 ng/mL on the $C_8$ column and 0.12 - 0.48 ng/mL on the amide column. This method using multiple SPEs offers significant benefits for high-throughput determination of HCAs in urine.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.10
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• pp.90-97
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• 1996

This paper presents an efficient parallel implementation and its performance evaluations of a SOFM neural netowrk on the multicomputer. We investigate the parallel performance as the size of a neural network N, the number of the patterns L, and the number of the processors p increase. We propose an analytica performance evaluation model for eac of the parallel implementations and verified the validity of the model through experiments. Analytical result show that the number of processors for a maximum speedup of the network decomposition nd the training-set decomposition increases in proportion to .root.N and .root.L, respectively. The performances of the both decompositions depend on the number of training patterns L and the size of the neural network N and, if L.geq.0.423N, the performance of trhe training-set decomposition is proved to be better than that of the network decomposition.

• Journal of Environmental Science International
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• v.7 no.5
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• pp.707-716
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• 1998

The chemical characteristics of precipitation was investigated in Pusan area. Samples were collected from January to November in 1996 at 4 sites, and analyzed pH, major soluble ionic components(C $l^{[-10]}$ , N $O_3$$^{[-10]}$ , S $O_4$$^{2-}$, N $a^{+}$, $K^{+}$, N $H_4$$^{+}$, $Mg^{2+}$, $Ca^{2+}$). The order of anion and cation concentrations for the initial precipitation were C $l^{[-10]}$ ＞ S $O_4$$^{2-}$ ＞ N $O_3$$^{[-10]}$ , and $Ca^{2+}$ ＞ N $a^{+}$ ＞ N $H_4$$^{+}$ ＞ $Mg^{2+}$ ＞ $K^{+}$, respectively. At coastal sites(P1 and P2) C $l^{[-10]}$ and N $a^{+}$ of maritime sources (seasalt) were high, but at inland sites(P3 and P4) nss-C $a^{2+}$ and nss-S $O_4$$^{2-}$ were high. Calcium ion for the initial precipitation showed high value of enrichement factor(EF) relative to seawater composition. The contribution of seasalt to the composition of precipitation was higher at bite P1 (53.5%) than those of the other sites. Throughout the year the concentrations of major ions for the initial precipitation were low in the heavy rain season. The mean pH for the initial precipitation was 5.4 and showed the negative relationship with the precipitaion amount. The S $O_4$$^{2-}$ and N $O_3$$^{[-10]}$ do not play an important role in rain acidification due to the high(97%) neutralizing effect of amonia and calcium species.and calcium species.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.7
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• pp.953-959
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• 2003

This study examined physicochemical properties of two waxy rice starches, shinsun and black rice starches. Proximate compositions of both samples were similar. The major minerals in the shinsun rice starches were Ca, Mg, P and Na, whereas those in black rice starches were Ca, P, Fe and Mg. The major particle size of shinsun rice starch was 6.97 micron and that of black rice starch was 6.27 micron. In iodine reaction, maximum absorbance wavelength (λmax) and absorbance at 625nm of black rice starch were higher than those of shinsun rice starch. Intrinsic viscosity of black rice starch (183mL/g) was higher than that of shinsun rice starch (178 mL/g). Water binding capacity was similar in both samples. Swelling power and solubility of black rice starch were lower than those of shinsun rice starch. X-ray diffraction patterns of all samples showed traditional A type of cereals as shown peaks at 15.2 (15.0), 17.2 (17.15), 18.05 (17.95), 23.25 (23.15)$^{\circ}$. The common shape of SEM was observed in both waxy rice starches.

• Journal of the Korean Society of Food Culture
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• v.10 no.2
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• pp.97-100
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• 1995

Three potato cultivars were prepared as slices and stored for 4 weeks at $5^{\circ}C$. Changes in Vitamin C content and other quality factors, such as color, pH, soluble solid and protein content were determined. Vitamin C content and L value decreased in three potato cultivars. Initial Vitamin C contents of three potato cultivars varied from 49.27 mg% in Sumi to 56.40 mg% in Namjak. Changes in L value showed that the tendency of browning in Daejima was slower than Sumi and Namjak. Changes in pH were small. Soluble solids and protein content increased and varied by cultivar. From the correlation analysis, correlation between browning degree and Vitamin C content was low in three potato cultivars.

• Steel and Composite Structures
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• v.16 no.1
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• pp.97-114
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• 2014

This paper deals with a study on ultimate strength behaviour of eccentrically loaded CFT columns with and without shear connectors. Thirty specimens are subjected to experimental investigation under eccentric loading condition. P-M curves are generated for all the test specimens and critical eccentricities are evaluated. Three different D/t ratios such as 21, 25 and 29 and L/D ratios varying from 5 to 20 are considered as experimental parameters. Six specimens of bare steel tubes as reference specimens, twelve specimens of CFT columns without shear connectors and twelve specimens of CFT columns with shear connectors, in total thirty specimens are tested. The P-M values at the ultimate failure load of experimental study are found to be well agreed with the results of the proposed P-M interaction model. The load-deflection and load-strain behaviour of the experimental column specimens are presented. The behaviour of the CFT columns with and without shear connectors is compared. Experimental results indicate that the percentage increase in load carrying capacity of CFT columns with shear connectors compared to the ordinary CFT columns is found to be insignificant with a value ranging from 6% to 13%. However, the ductility factor of columns with shear connectors exhibit higher values than that of the CFT columns without shear connectors. This paper presents the proposed P-M interaction model and experimental results under varying parameters such as D/t and L/D ratios.

• Food Science of Animal Resources
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• v.32 no.4
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• pp.512-519
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• 2012

The current study was conducted to investigate the effect of macsumsuk and herb resources on the performances and meat quality of broiler chickens. Six hundreds (600) broiler chickens were randomly allocated into four groups (4 groups${\times}$50 chickens/group${\times}$3 replica), Control, Treatment 1 (T1; 0.3% macsumsuk), Treatment 2 (T2; 0.3% herb resources), and Treatment 3 (T3; 0.3% macsumsuk + 0.3% herb resources) and fed for 5 wk. T2 group showed higher total body weight gain and average daily gain of 1,812.5 g and 51.79 g, respectively, than the other groups. Control group showed the highest (p<0.05) mortality (8%) and total blood cholesterol (111.8 mg/dL) among experimental groups. T3 group (6.71 mg/dL) showed the highest (p<0.05) while control group (4.50 mg/dL) showed the lowest (p<0.05) in blood IgG levels. Cooking loss was 17.08, 16.14, 16.55, and 15.25%, shear force value was 1.91, 1.52, 1.55, and 1.47 $kg/cm^2$, and water holding capacity (WHC) was 54.40, 55.97, 56.01, and 55.70% for Control, T1, T2, and T3, respectively. Cholesterol contents in breast meat of Control (88.91 mg/100 g) chickens showed the highest (p<0.05) levels comparing to either T1 (83.59 mg/dL), T2 (82.41 mg/dL), or T3 (80.81 mg/dL) chickens. In conclusion, the current study implies that feeding macsumsuk and herb resources to broiler chickens could decrease cholesterol contents in breast meat.