• Food Science and Preservation
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• v.13 no.5
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• pp.661-667
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• 2006

This study was carried out to analyze the major chemical component of the leaf and stem of dried Petasites japonicus S. et Z. Max.. Comparing proximate composition of leaf and stem of Petasites japonicus as dry matter basis, stem contained higher moisture, crude fat, crude ash and carbohydrate, with less crude protein. The main component of free sugar and disaccharide in both leaf and stem were fructose and sucrose, respectively. Total amino acids of leaf and stem were 6,853.32 mg% and 2,350.61 mg% respectively. Although the amino acid composition of leaf and stem were different glutamic acid and aspartic acid were the major amino acids in samples. The major fatty acids of total lipids were linolenic acid in leaf and linoleic acid in stem. The ratios of unsaturated fatty acids to saturated fatty acid were 3.93 in leaf and 3.44 in stem. The unsaturated fatty acid content of samples were 3 times higher than those of saturated fatty acid contents. Oxalic acid was the major organic acids in leaf and stem. The contents of vitamin A, C and E were higher in leaf than in stem. The mined compositions of both leaf and stem were composed in order of K, Mg, Ca, Fe, Na, and Zn.

• Journal of the East Asian Society of Dietary Life
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• v.21 no.2
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• pp.215-221
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• 2011

The goal of this study was to evaluate the quality characteristics of various beans in distribution. The quality characteristics investigated were proximate composition, color, free sugars, organic acids, amino acids, and minerals. Bean samples analyzed were white soybeans (Glycine max. (L.) Merrill), kidney beans (Phaseolus vulgaris var. humilis), black soybeans (Glycine max (L.) Merr.), black small soybeans (Rhynchosia nulubilis), sword beans (Canavalia gladiata), and green beans (Phaseolus vulgaris). The highest contents of crude fat and crude protein were 17.60${\pm}$0.14% for white soybeans, and 42.38${\pm}$0.15% for black soybeans, respectively. Higher color values compared to the other samples were $L^*$ (64.07${\pm}$0.97) for sword beans, $a^*$ (15.64${\pm}$0.48) for kidney beans, and $b^*$ (22.92${\pm}$0.09) for white soybeans. The highest contents of sucrose, oxalic acid, and malic acid in black small soybeans were 54.23 mg/g, 23.26 mg/100 g and 18.24 mg/100 g, respectively. Xylose, galactose, lactose, malonic acid, succinic acid, and lactic acid were not detected in the soybeans studied, whereas the glutamic acid content of soybeans ranged from 2.68 to 6.18 g/100 g. Levels of K and Mg contents in soybean were higher than those of the other minerals.

• Korean Journal of Materials Research
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• v.12 no.9
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• pp.761-766
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• 2002

Fine $LaPO_4$:Tb phosphor particles with spherical shape were prepared by spray pyrolysis. The influence of the precursor type of phosphorous such as ($NH_4$)$_2$$HPO_4$, $NH_4$$H_2$$PO_4$, ($NH_4$)$_3$$PO_4$ and $H_3$$PO_4$ on the morphology and brightness of particles was investigated. As-prepared particles by spray pyrolysis had spherical shape when ($NH_4$)$_2$ $HPO_4$ and $NH_4$$H_2$$PO_4$ were used as the precursor of phosphorous. The precursor type of phosphorous affected the photoluminescence intensity of $LaPO_4$:Tb phosphor particles, but not significant. With changing the content of activator(Tb) and excess of phosphorous, the optimal composition giving the highest photoluminescence intensity was found. The spherical morphology of prepared $LaPO_4$:Tb particles was completely maintained even after the posttreatment up to $1050^{\circ}C$. When the posttreatment temperature was over $1100^{\circ}C$, the particles did not have the spherical shape anymore. However, the highest photoluminescence intensity of prepared $LaPO_4$:Tb particles was obtained at $1050^{\circ}C$. The photoluminescence characteristics of prepared $_LaPO4$:Tb under the vacuum ultraviolet(VUV) illumination was comparable with that of the commercial $Zn_2$$V_4$:Mn and (La,Ce)PO$_4$:Tb phosphor particles. At the optimal condition, the decay time of prepared spherical $LaPO_4$:Tb phosphor particles was about 6.8ms.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.4
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• pp.591-596
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• 2011

The applications of chemical fertilizers and various types of organic materials may cause heavy metal accumulation in soil. In this study, we conducted to investigate the relationship between the different chemical forms of heavy metals such as Cr, Cd, Pb, Cu, Ni, and Zn retained in soil and the metal concentrations in Korean raspberry plant. Forty five soil samples were collected from 2 to 6 years old Korean raspberry cultivation fields (RCFs), Gochang, Korea, to determine total, exchangeable (1.0 M $MgCl_2$-extractable), DTPA-extractable metal contents. The leaves and fruits of raspberry plant were sampled at harvest stage. Total metal contents in soils ranged from $0.87mg\;kg^{-1}$ to $66.82mg\;kg^{-1}$. Exchangeable and DTPA-extractable metals ranged between 0.02 and $0.67mg\;kg^{-1}$ and between $0.05mg\;kg^{-1}$ and $7.07mg\;kg^{-1}$, respectively. The metal concentrations in the plant leaf and fruit determined on a dry-basis were between $1.30mg\;kg^{-1}$ and $38.82mg\;kg^{-1}$ and between $0.05mg\;kg^{-1}$ and $21.51mg\;kg^{-1}$, respectively, but Cd and Pb were not detected in the leaf. The total, exchangeable, and DTPA-extractable contents of the metal ions in soil were directly correlated one another, but the contents of different metals in the different fractions were inversely correlated in general. Most of total and DTPA-extractable metals in the soil were directly correlated with the contents of the same metals in the plant, whereas exchangeable metals in the soil were not statistically correlated with the same metals in plants. Thus, we concluded that the metal contents in the raspberry field soils were much lower thanthe levels of Soil Contamination Warning Standard (SCWS), and the plant metal concentrations were also less than the maximum permissible limits. The total and DTPA-extractable metals in the soil were closely related to the metal concentrations in the plant.

• Korean Journal of Food Science and Technology
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• v.52 no.2
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• pp.119-124
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• 2020

Populus Tomentiglandulosa (PT) is known for pharmacological effects against ischemia-injury and immune activity. This study aimed to investigate the nutritional components, total phenol and flavonoid contents, antioxidant activities of PT extract. Among the mineral contents, the K content (907.5 mg/100 g) was the highest in the PT extract. Vitamins C (6.1 mg/100 g) and nicotinic acid (3.1 mg/100 g) were also found in high amounts. Fructose (2.2%) and glucose (1.6%) were found as free sugars in the PT extract. The total phenolic and flavonoid contents of PT extract were 115.4±0.85 mg GAE/g and 20.9±1.14 mg QE/g, respectively. Results of HPLC analysis of PT extract identified catechin (9.1±0.27 mg/g), caffeic acid (4.1±0.57 mg/g), p-coumaric acid (2.1±0.49 mg/g), chlorogenic acid (1.6±1.86 mg/g), and gallic acid (1.4±0.35 mg/g), respectively. These results suggest that the PT extract possesses high nutritional component and antioxidant properties, which can be used as functional bioresources.

• Food Science and Preservation
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• v.15 no.5
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• pp.706-710
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• 2008

This study evaluated the chemical components of five watermelon cultivars. Soluble solids and pH value in the Uoriggul cultivar were higher than those in other cultivars. The mineral components of watermelon were K (106.25-161.22 mg/100 g), P (11.29-20.98 mg/100 g), Mg (5.29-11.10 mg/100 g), Ca (4.10-5.63 mg/100 g), Na (0.92-1.28 mg/100 g), and Fe (0.25-0.46 mg/100 g). The contents of P, K, Na, Fe, Cu, and Zn in the Dalgona cultivar were higher than in other cultivars. The major free sugars of watermelon were fructose (3019.40-4311.11 mg/100 g), glucose (1070.02-1526.41 mg/100 g), and sucrose (4583.68-5341.07 mg/100 g). The total free sugar content was highest in the Uoriggul cultivar. Sensory evaluation revealed that the color, flavor, taste, texture and overall acceptability of Uoriggul were the highest among the cultivars.

• Korean Journal of Heritage: History & Science
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• v.51 no.4
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• pp.224-233
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• 2018

Thirty-three Early Iron Age bronzes at the sites of Hoam-dong in Chungju and Cheongsong-ri in Buyeo were investigated in order to study the manufacturing technique and the provenance of lead. Chemical analysis using X-ray fluorescence showed that 33 bronzes consist of copper(Cu), tin(Sn) and lead(Pb) served as major elements. Major and minor elemental analyses by EPMA were performed on two mirrors and 2 weapons of the bronzes investigated. The results shows that bronze mirrors from Chungju and Buyeo were high-tin bronzes(> 30 wt%). And 20% of tin and 5% of lead were founded in bronze weapons. Iron, zinc, arsenic, silver, nickel, sulfur and cobalt detected in four bronzes as minor and trace elements. The four bronzes were alloyed considering their function and were not heat treated after casting due to their high tin content. Lead isotope analysis using TIMS indicates that thirty-three bronzes were distributed southern Korea peninsula except Zone 1. As a result, lead raw materials came from various regions in Korean Peninsula not from Gyeongsang-do regions. The manufacturing techniques of bronze ware generalized at this age, and bronze was produced in various sites using raw materials from various sources.

• Applied Chemistry for Engineering
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• v.33 no.1
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• pp.50-57
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• 2022

Ti-In-Zn-O (TIZO)/Ag/TIZO multilayer transparent electrodes were prepared on glass substrates at room temperature using RF/DC magnetron sputtering. Obtained multilayer structure comprising TIZO/Ag/TIZO (10 nm/10 nm/40 nm) with the total thickness of 60 nm showed a transmittance of 86.5% at 650 nm and a sheet resistance of 8.1 Ω/□. The multilayer films were expected to be applicable for use in energy-saving smart window based on polymer-dispersed liquid crystal (PDLC) because of their transmittance properties to effectively block infrared rays (heat rays). We investigated the effects of the content ratio of prepolymer, the thickness of the PDLC coating layer, and the ultraviolet (UV) light intensity on electro-optical properties, and the surface morphology of polyester acrylate-based PDLC systems using new TIZO/Ag/TIZO transparent conducting electrodes. A PDLC cell with a thickness of 15 ㎛ PDLC layer photocured at an UV intensity of 1.5 mW/cm² exhibited good driving voltage, favorable on-state transmittance, and excellent off-haze. The LC droplets formed on the surface of the polymer matrix of the PDLC composite had a size range of 1 to 3 ㎛ capable of efficiently scattering incident light. Also, the PDLC-based smart window manufactured using TIZO/Ag/TIZO multi-layered transparent electrodes in this study exhibited a light brown, which will have an advantage in terms of aesthetics.

• Korean Journal of Food Science and Technology
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• v.54 no.1
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• pp.80-87
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• 2022

We investigated the effects of organic acid and ultrasonication treatment in maintaining the quality of garlic during storage. Samples were exposed for 5 min to either ultrasonication at 60℃, 1% citric acid, or 0.5% fumaric acid. Presence of microorganisms and minerals, hardness, and color were compared during storage at 4℃ for 28 days. The total aerobic bacterial count remained low. No proliferation of Escherichia coli was observed after treatment with fumaric acid or ultrasonication, and mold proliferation was inhibited by ultrasonication. The mineral content of the northern type garlic was higher than that of the southern type. Exposure to fumaric acid did not result in a substantial difference in hardness until 21 days of storage, at which time there was a decrease in the L-value in each cultivation type. Our results indicate that treatment with 0.5% fumaric acid for 5 min was effective in reducing the abundance of microorganisms during storage without affecting the hardness or color in garlic.

• Korean Journal of Materials Research
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• v.34 no.1
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• pp.1-11
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• 2024

This research investigated the preparation of activated carbon derived from Krabok (Irvingia malayana) seed shells to improve the quality of crude glycerol obtained during biodiesel production. The activated carbon was prepared using a dry chemical activation method with NaOH, utilizing an innovative biomass incinerator. The results revealed that the resulting KC/AC-two-step exhibited favorable physicochemical adsorption properties, with a high surface area of 758.72 m²/g and an iodine number of 611.10 mg/g. These values meet the criteria of the industrial product standard for activated carbon No. TIS 900-2004, as specified by the Ministry of Industry in Thailand. Additionally, the adsorption efficiency for methylene blue reached an impressive 99.35 %. This developed activated carbon was then used to improve the quality of crude glycerol obtained from biodiesel production. The experimental results showed that the KC/AC-two-step increased the purity of crude glycerol to 73.61 %. In comparison, commercially available activated carbon (C/AC) resulted in a higher crude glycerol purity of 81.19 %, as analyzed by the GC technique. Additionally, the metal content (Zn, Cu, Fe, Pb, Cd, and Na) in purified glycerol using KC/AC-two-step was below the standards for heavy metals permitted in food and cosmeceuticals by the Food and Drug Administration of Thailand and the European Committee for Food Contact Materials and Articles. As a result, it can be inferred that Krabok seed shells have favorable properties for producing activated carbon suitable as an adsorbent to enhance crude glycerol purity. Furthermore, the improved crude glycerol from this research has potential for various industrial applications.