• Journal of Korean Society for Atmospheric Environment
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• v.34 no.4
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• pp.554-566
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• 2018

The rice husk contains nutrients which can be easily utilized by microorganisms, and also has a water retaining ability, which played a crucial part in enabling it to become a biofilter media. In this study, we evaluated the applicability of rice husk pellet bio-scrubber as a microbiological carrier. The pelletization experiment of rice husk as a biological media was performed using PVA and EVA binder. Also, the feasibility tests of rice husk as a biological media for odor removal were carried out in order to know whether rice-husk contains useful components as a media for microbiological growth or not. Lastly, a combined test for odor gas absorption and biological oxidation was conducted using a lab scale bio-filter set-up packed with rice-husk pellets as wet-scrubber. The major components of the rice husk were carbon, hydrogen, nitrogen, and oxygen, while carbon acted as the main ingredient which comprised up to 23.00%. The C : N : P ratio was calculated as 45 : 1 : 2. Oxygen uptake rate, yield and decay rate of the rice husk eluent was calculated to be $0.0049mgO_2/L/sec$, 0.24 mgSS/mgCOD and 0.004 respectively. The most stable form of rice husk pellets was produced when the weight of the rice husk, EVAc, PVAc, and distilled water was 10 : 2 : 0.2 : 10. The prepared rice husk pellets had an apparent density of 368 g/L and a porosity of 59.00% upon filling. Dry rice husks showed high adsorption capacity for ammonia gas but low adsorption capacity for hydrogen sulfide. The bio-filter odor removal column filled with rice husk pellets showed more than 99.50% removal efficiency for NH3 and H2S gas. Through the analysis of circulation water, the prime removal mechanism is assumed to be the dissolution by water, microbial nitrification, and sulfation. Finally, it was confirmed that the microorganisms could survive well on the rice husk pellets, which provided them a stable supply of nutrients for their activity in this long-term experiment. This adequate supply of nutrients from the rice husk enabled high removal efficiency by the microorganisms.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.4
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• pp.267-279
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• 1990

The temporal and spatial distribution of the coastal cold waters which was formed due to winter colling in the South Sea of Korea was analyzed by IR images from satellite and in situ data from shipboard observations. The coastal waters are known to be consisted of the Yellow Sea Coastal Waters(YSCW) and the South Korean Coastal Waters(SKCW). The former is driven around the Chuja-do and drifted into the Cheju Strait by residual currents, while the latter expands toward offsea by southward wind forcing. The expansion patterns of the SKCW were observed as sinking expansion or drifting expansion such that both were strongly dependent on the surface heat flux conditions. Under the condition of positive heat flux(warmer sea surface) or when the sea surface heat is lost to the atmosphere, the surface water started sinking and eventually expanded toward the open sea causing the cooling of the water column. For the negative heat flux the surface water was just drifted horizontally and expanded seaward and in this case only the surface layer of water was cooled.

• Journal of the Korean Society of Food Science and Nutrition
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• v.19 no.6
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• pp.625-635
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• 1990

The purpose of this study was focused on investigation of biochemical properties of amylases in germinating corn(Zea mays L.) the amylase(I), (II) and (III) from germinating corn seeds were partially purified by ammonium sulfate precipitation, DEAE-Sephadex A-50 ion exchange column chromatography and Sephadex G-100 gel filtration. The last step was effective for separation of the corn amylases to a homogeneous slate. the purified amylase(I) was identified as a kind of $\alpha$-amylase from the fact that 5％ starch solution was hydrolysed into mainly maltose and maltotetrose by it, and amylase(II) and amylase(III) were enzymes producing maltotetrose as main product. The molecular weight and specific activity of the amylase(I), (II) and (III) were determined to be 54,000 and 70.47 unit/mg, 39,000 and 62.98 unit/mg, and 51,000 and 80.39 unit/mg, respectively. It showed a tendency to increase the amylases activities in presence of Ba, Ca, Co and Fe groups, but inhibits in that of Ag, Sn, Hg and Zn groups, and amylase(I), (II) and (III) remained stable at pH 5-6 and 2$0^{\circ}C$ for 40 days in containing of 1 mM CaCl$_2$. The optimum pH and optimum temperatures were pH 6, pH 5 and pH 6 and 35$^{\circ}C$, 55$^{\circ}C$ and 55$^{\circ}C$, respectively. These results suggest that the amylase(I), (II) and (III) were different amylases.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.2
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• pp.175-180
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• 1984

Lipids in oyster mushroom (Pleurotus florida) were extracted by the mixture of chloroform-methanol (2: 1, v/v) and fractionated into neutral lipids, glycolipids and phospholipids by silicic acid column chromatography. Components and fatty acid composition of each fraction were deter- mined by thin-layer and gas-liquid chromatographies. Fresh oyster mushroom contained 0.5% total lipid in which the contents if neutral lipids, glycolipids and phospholipids were 33.8%, 19.7% and 45. 6%, respectively, Triglycerides(38.2%), free fatty acids (20%) and free sterol (10%) were the major components among the neutral lipids. Diglycerides, monoglycerides, sterol esters and three unidentified neutral lipids were the minor components. Major components of glycolipids were steryl glycosides(35.9%) and esterified steryl glycosides (23.7%). Digalactosyl diglycerides, mono-galactosyl diglycerides and two unknown components were also present. Of the phospholipids, phosphatidyl cholines and serines (48.2%), and phosphatidyl ethanolamines(44.4%) were the major components. On the other hand, the major fatty acids of neutral lipids we.e linoleic, palmitoleic, oleic and palmitic acid. Linoleic and palmitic acid were the predominant fatty acids of both glycolipids and phospholipids.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.11
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• pp.1682-1686
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• 2015

This study was conducted to establish an HPLC analysis method for determination of marker compounds as part of materials standardization for development of health functional food materials from pear pomace. The quantitative determination method of caffeic acid and chlorogenic acid as marker compounds of pear pomace extract (PPE) was optimized by HPLC analysis using a C18 column ($5{\times}250mm$, $5{\mu}m$) with a 0.2% elution gradient of acetic acid and methanol as the mobile phase at a flow rate of 0.8 mL/min and detection wavelength of 330 nm. The HPLC/UV method was applied successfully to the quantification of marker compounds in PPE after validation of the method with linearity, accuracy, and precision. The method showed high linearity of the calibration curve with a coefficient of correlation ($R^2$) of 0.9999, and limit of detection and limit of quantification were $1.14{\mu}g/mL$ (caffeic acid) and $1.61{\mu}g/mL$ (chlorogenic acid) as well as $4.9{\mu}g/mL$ (caffeic acid) and $4.9{\mu}g/mL$ (chlorogenic acid), respectively. Relative standard deviation values from intra- and inter-day precision were less than 3.1% (caffeic acid) and 4.0% (chlorogenic acid), respectively. Recovery rates of caffeic acid and chlorogenic acid at 12.5, 25, and $50{\mu}g/mL$ were 93.66~106.32% and 97.33~105.68%, respectively. An optimized method for extraction of caffeic acid and chlorogenic acid in PPE was established through diverse extraction conditions, and the validation indicated that the method is very useful for evaluation of marker compounds in PPE to develop a health functional food material.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.67-67
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• 2018

Trichoderma species are a rich source of metabolites, but less known for biomedical potential. This work deals with antibacterial and antioxidant potentials of intracellular non-cytotoxic metabolites, extracted from Trichoderma atroviride (KNUP001). A total of 53 fractions was collected by column chromatography and tested for cytotoxicity by MTT assay. Only one fraction (F41) was found to be non-toxic to Vero cells with $95.4{\pm}0.61%$ of survival. The F41 was then subjected to chemical analysis, antibacterial and antioxidant assays. The F41 at $500{\mu}g.ml^{-1}$ showed the total antioxidant of $48.70{\pm}2.90%$, DPPH radical scavenging activity of $37.25{\pm}2.25$, nitric oxide (NO) radical scavenging activity of $54.55{\pm}1.95$ and $H_2O_2$ radical scavenging activity of $43.75{\pm}3.21$. The F41 at $25{\mu}g.ml^{-1}$ displayed antibacterial activity against E. coli ($14.25{\pm}0.2mm$), P. mirabilis ($10.4{\pm}0.6mm$), S. dysenteriae ($18.6{\pm}03mm$), S. paratyphi A ($14.1{\pm}1.1mm$), E. aerogenes ($5.6{\pm}0.4mm$) and S. marcescens ($14.25{\pm}0.2mm$). GC-MS analysis revealed the dominant presence of oleic acid C 18.1 (63.18%), n-hexadecanoic acid (6.17%), and ethyl oleate (4.93%) and potent molecules such as 8-[(2E)-2-(3-hydroxybenzylidene)hydrazinyl]-1,3,7-trimethyl-3,7-dihydro-1H-purine-2,6-dione, 2-(Dimethylamino)ethyl (1Z)-N-hydroxy-2-(4-morpholinyl)-2-oxoethanimidothioate, Fluorene in the F41, and virtual study revealed that these molecules are likely responsible for the antibacterial activities of F41. Hence, further investigation deserves on purification and characterization of the active metabolites from T. atroviride strain KNUP001 towards developing molecular leads to effective antibacterial drugs, and non-toxic to host cells.

• Journal of the Korea Concrete Institute
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• v.22 no.1
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• pp.19-27
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• 2010

Aging and severe environments are major causes of damage in reinforced concrete (RC) structures such as buildings and bridges. Deterioration such as concrete cracks, corrosion of steel, and deformation of structural members can significantly degrade the structural performance and safety. Therefore, effective and easy-to-use methods are desired for repairing and strengthening such concrete structures. Various methods for strengthening and rehabilitation of RC structures have been developed in the past several decades. Recently, FRP composite materials have emerged as a cost-effective alternative to the conventional materials for repairing, strengthening, and retrofitting deteriorating/deficient concrete structures, by externally bonding FRP laminates to concrete structural members. The main purpose of this study is to investigate the effectiveness of adaptive neuro-fuzzy inference system (ANFIS) in predicting behavior of circular type concrete column retrofitted with FRP. To construct training and testing dataset, experiment results for the specimens which have different retrofit profile are used. Retrofit ratio, strength of existing concrete, thickness, number of layer, stiffness, ultimate strength of fiber and size of specimens are selected as input parameters to predict strength, strain, and stiffness of post-yielding modulus. These proposed ANFIS models show reliable increased accuracy in predicting constitutive properties of concrete retrofitted by FRP, compared to the constitutive models suggested by other researchers.

• Journal of the Korea Concrete Institute
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• v.24 no.3
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• pp.259-266
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• 2012

A general earthquake resistant design philosophy of ductile frame buildings allows beams to form plastic hinges adjacent to beam-column connections. In order to carry out this design philosophy, the ultimate bond or shear strength of the beam should be greater than the flexural yielding force and should not degrade before reaching its required ductility. The behavior of RC members dominated by bond or shear action reveals a dramatic reduction of energy dissipation in the hysteretic response due to the severe pinching effects. In this study, a method was proposed to predict the deformability of reinforced concrete members with short-span-to-depth-ratios, which would result in bond failure after flexural yielding. Repeated or cyclic loading produces a progressive deterioration of bond that may lead to failure at lower cyclic bond stress levels. Accumulation of bond damage is caused by the propagation of micro-cracks and progressive crushing of concrete in front of the lugs. The proposed method takes into account bond deterioration due to the degradation of concrete in the post yield range. In order to verify bond deformability of the proposed method, the predicted results were compared with the experimental results of RC members reported in the technical literature. Comparisons between the observed and calculated bond deformability of the tested RC members showed reasonably good agreement.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.4
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• pp.436-442
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• 1992

The present study was designed to analyze the lipid and fatty acid compositions of ark shell, Anadara broughtonii. The crude lipid was extracted by Bligh and Dyer's method, and then fractionated by TLC and quantitatively analyzed by TLC scanner. Lipid extracted from ark shell was fractionated into neutral and polar lipid by column chromatography with silicic acid. The fatty acid composition of lipid fractions were determined by gas liquid chromatography. Total lipid content of ark shell was 0.83% base on wet weight. The content of unsaponifiable matter was 20.19%, and iodine value was 156.13. The main components of total lipids were triglyceride, diglyceride, hydrocarbon, and sterol ester. The fatty acid composition of total lipid chiefly consisted of $C_{17 : 0}$, $C_{16 : 0}$, $C_{18 : 1}$ and $CT_{16 : 1}$. The main fatty acids of neutral lipid were $C_{16 : 0}$, $C_{18 : 1}$, $C_{22 : 1}$, $C_{18 : 0}$ and $C_{16 : 1}$. The major fatty acids of polar lipid were $C_{16 : 0}$, $C_{18 : 2}$, $C_{20 : 5}$ and $C_{22 : 6}$. In total lipid fractionation, saturated acid contents were high in all (SA>MA＞ PA), in neutral lipid fractionation, menoenoic acid contents were high in all (MA > SA> PA), and in polar lipid fractionation, saturated acid con-tents were high in all (SA> PA> MA).

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.3
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• pp.263-267
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• 1984

The present study was conducted to elucidate the triglyceride composition of walnut oil. The triglycerides were separated by thin layer chromatography (TLC) and fractionated on the basis of partition numbers by reverse phase high performance liquid chromatography (HPLC) on a column packed with $\mu$-bondapak $C_{18}$ using methanol-chloroform mixture as a solvent system. Each of these collected fractions was fractionated again on the basis of acyl carbon number of triglyceride by gas liquid chromatography (GLC). The fatty acid composition of triglycerides for each partition numbered group was also analyzed by GLC. From the results, it was found that walnut oil consists of ten kinds of triglycerides, and the patterns of major ones in walnut oil were as follows: 53.3% of $(C_{18:2},\;C_{18:2},\;C_{18:2})$, 10.1% of $(C_{18:1},\;C_{18:2},\;C_{18:2})$, 5.4% of $(C_{18:1},\;C_{18:1},\;C_{18:2})$, 4.3% of $(C_{18:1},\;C_{18:2},\;C_{18:3})$, 3.9% of $(C_{18:0},\;C_{18:2},\;C_{18:2})$, 2.0% of $(C_{18:0},\;C_{18:1},\;C_{18:2})$, 1.8% of $(C_{18:0},\;C_{18:2},\;C_{18:2})$.