• Journal of the Korean Society of Safety
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• v.21 no.3 s.75
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• pp.73-80
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• 2006

Generally beam design depends on the yielding and maximum strength of each member varying with its section shape. Web plate of H-shape beam has not been substituted with glass plate, because it is known that its strength and heat properties are different and it is limited to substitute the existing steel web with glass element. Ceiling height of each room should be decreased with more than 60-80cm due to the beam. Differently from this condition, glass web beam has a good point to see through it and sunshine can be penetrate into the other size especially when it is installed as of outside wall. And also, it can be safer due to controlling room inside easier, if the strength is applicate. This study is to show some applicability after finding out the properties using the test. The test members with a size of $1,600{\times}200{\times}300{\times}9mm$ being SS41 rolled steel having THK 9mm flange while having 8,10mm and reinforced glass 12mm thickness is bonded with epoxy bond under the condition of temperature $28^{\circ}C$, humidity 50%, bonding power 24Mpa. It is show reinforced glass has 5 times of fracture stress more than the common glass but $50{\sim}150%$ difference between these 2 kinds of glass was shown. Reinforce glass did not support the original upper flange after fracture but the common glass did the upper flange after unloading. Generally reinforced glass is stronger than the common one but the common glass having a part of crack on it, compared with reinforced glass having the overall fracture could be more useful in case of needing ductility.

• Journal of Crop Science and Biotechnology
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• v.11 no.1
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• pp.31-38
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• 2008

Improvement of $N_2$ fixation by symbiotic rhizobia is considered an effective means for enhancing its productivity without high input of nitrogen(N) fertilizer. Several methods to improve $N_2$ fixation have been proposed including the use of supernodulating mutants. The objective of this research was to identify the varietal difference in N and $N_2$-fixation ability among the soybean supernodulating mutants, SS2-2 and Sakukei 4, with different nodulation abilities using $^{15}N$ in field conditions in both Korea and Japan. The dry weight(DW) was higher in wild-type soybeans. The distribution rate of DW in each plant part was high in seeds of supernoduating and wild-type soybeans but high in stems and leaves of non-nodulating mutants. Although the supernodulating mutants had a low DW rate at maturity, they showed a similar $N_2$ fixation ability compared with wild-type. Supernodulating mutant plants mainly obtained N from $N_2$ fixation, while soil N was the main resource for obtaining N in non-nodulating mutants. The percentage of N derived from atmospheric dinitrogen(Ndfa) was higher in supernodulating mutants than in wild-type and relatively high in seeds between plant parts at maturity. In particular, supernodulating mutants showed higher N content in roots than those of wild-type and non-nodulating mutants. It was considered that supernodulating mutants have the advantage of saving nitrate in soil and being beneficial for N absorption of subsequent crops due to their conserving more N in the field and releasing considerable amounts of N from roots and leaves fallen to the soil.

• Journal of Environmental Science International
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• v.20 no.3
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• pp.291-299
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• 2011

The main objectives of this research are to investigate characteristics of ozone solubility due to low solubility of conventional bubbles-ozone generators, evaluate the treatment characteristics of reclaiming textile wastewater for industrial water by means of micro/nano bubbles-dissolved ozone flotation(MNB-DOF) process. The textile wastewater used in this research was obtained from final effluent of the textile wastewater in B city. There is a 400L reactor which consists of a micro-nano bubble system and a ozone generator for experiments. As a result of generating micro-nano bubbles (below $0.5{\mu}m$) by using of MNB-DOF process, it improved ozone solubility due to higher ozone transfer rates. Consequently, the shorter ozonation time clearly indicates the lower power costs. The reported results clearly indicated that MNB-DOF process can be effectively and inexpensively. Results of the experiments through MNB-DOF process in this study satisfy all reclaiming standards as industrial water: pH 6.5~8.5, SS 10 mg/L or below, $BOD_5$) 6 mg/L or below, turbidity 10 NTU or below, Coliforms 1,000/100 mL or below. Therefore there is a possibility of the reclaiming of the textile wastewater as industrial water.

• Journal of Korea Society of Waste Management
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• v.35 no.7
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• pp.653-659
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• 2018

In the industrial wastewater that occupies a large proportion of river pollution, the wastewater generated in textile, leather, and plating industries is hardly decomposable. Though dyeing wastewater has generally been treated using chemical and biological methods, its characteristics cause treatment efficiencies such as chemical oxygen demand (COD) and suspended solids (SS) to be reduced only in the activated sludge method. Currently, advanced oxidation technology for the treatment of dyeing wastewater is being developed worldwide. Electro-coagulation is highly adapted to industrial wastewater treatment because it has a high removal efficiency and a short processing time regardless of the biodegradable nature of the contaminant. In this study, the effects of the current density and the electrolyte condition on the COD removal efficiency in dyeing wastewater treatment by using electro-coagulation were tested with an aluminum anode and a stainless steel cathode. The results are as follows: (1) When the current density was adjusted to $20A/m^2$, $40A/m^2$, and $60A/m^2$ under the condition without electrolyte, the COD removal efficiency at 60 min was 62.3%, 72.3%, and 81.0%, respectively. (2) The removal efficiency with NaCl addition was 7.9% higher on average than that with non-addition at all current densities. (3) The removal efficiency with $Na_2SO_4$ addition was 4.7% higher on average than that with non-addition at all current densities.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.1
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• pp.93-101
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• 2014

Asymmetric 1,2-distearoyl-3-oleoyl-rac-glycerol (SSO) triacylglycerol (TAG) is used as a cocoa butter replacer (CBR). In this study, it was produced by lipase-catalyzed interesterification of fully hydrogenated soybean oil (FHSBO) and oleic ethyl ester (OEE) in a batch type reactor at $75^{\circ}C$, 250 rpm. Different molar ratios (FHSBO : OEE=1:1, 1:2 and 1:3, w/w) and various reaction times (1, 2, 3, 4, and 5 hr) were also tested. The optimized condition for SSO was a FHSBO : OEE molar ratio of =1:1 at reaction times of 2, 3, 4, and 5 hr. Enzymatic synthesis generated SSO/SOS, as well as the other TAGs (e.g., PSO/POS, SOO/OSO, SSS), ethyl esters, monoacylglycerol (MAG), and diacylglycerol (DAG). After scale-up, fractionation by solvent (methanol and acetone) fractionation and column chromatography was applied. To reduce ethyl esters, high-melting TAGs (e.g., SSS), and SOO/OSO in reactants, solvent fractionation was applied. Using a silica gel column (sample : silica gel=2:1, wt%), MAG and DAG were removed at $25^{\circ}C$. The major fatty acid composition of the final products (with a high SSO/SOS content) was palmitic acid (C16:0, 10.9~12.9 area%), stearic acid (C18:0, 52.2~54.9 area%), and oleic acid (C18:1, 34.2~35.5 area%). In reversed-phase HPLC analysis, the major TAG species of the final product (FHSBO : OEE=1:1, 2 hr) were SSO/SOS (82.31 area%) and PSO/POS (14.51 area%). Based on the $[SS]^+$ : $[SO]^+$ ratio obtained by RP-HPLC/APCI-MS, the final product had a higher SSO (AAB type TAG) content than cocoa butter (CB). The solid fat index (SFI) of CB and the final product obtained were similar with a narrow melting point range around ~32 to $35^{\circ}C$.

• Journal of the Korea Organic Resources Recycling Association
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• v.14 no.4
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• pp.113-120
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• 2006

Wastewater generated through the food waste recycling process have known high concentration, BOD 20,000~150,000 mg/L, which has to treat to the proper level because of a ban on reclamation. But it is impossible to treat less than 10 days by existing water treatment plant. Ecodays Ltd. is to treat this wastewater during 2~4 days by ER-1, which can simultaneously induce the modified PFR(Plug Flow Reactor) of the oxygen transfer rate, MLVSS concentration, and influent concentration to top from bottom of reactor. We tested the pilot test about low concentration food wastewater(BOD 16,500 mg/L) and high concentration food wastewater(64,431 mg/L) at the food waste recycling plant of H-Gun(20t/d). Hydraulic retention time(HRT) of ER-1 for low concentration food wastewater is 2.5day. In low concentration conditions, ER-1 treatment efficiency is to appear BOD 99%, COD 98%, TN 97%, and TP 96%. While ER-1 process for high concentration food wastewater treatment is composed 2 stages, which are to be HRT 2.5day for law wastewater and HRT 1.5 day for secondary treatment. In high concentration conditions, ER-1 treatment efficiency is to appear BOD 97%, COD 84%, TN 66%, and TP 95%. It is treated without temperature control about high temperature($50^{\circ}C$) to appear low treatment efficiency in high concentration conditions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.9
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• pp.1328-1334
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• 2010

Low-trans spread fat (LTSF) was produced by lipase-catalyzed synthesis of canola (CO) and fully hydrogenated soybean oil (FHSBO) at 65:35 (w/w). Blend of CO and FHSBO with 65:35 ratio was interesterified using Lipozyme TLIM (immobilized Thermomyces lanuginosus, 20% of total substrate) in a 1 L-batch type reactor at $70^{\circ}C$ with 500 rpm for 24 hr. Then, physicochemical melting properties of LTSF were compared with commercial spread fat. At $20^{\circ}C$, solid fat contents (SFC) of commercial spread fat as a control and LTSF were similar, showing 19.1 and 18.1%, respectively. Major compositional fatty acids of LTSF were C18:0, C18:1 and C18:2 (29.2, 41.8 and 13.3 wt%, respectively). Trans fatty acid content of the LTSF (0.2 wt%) was lower than that of commercial spread fat (5.5 wt%). In the RP-HPLC analysis from LTSF, major triacylglycerol (TAG) molecules were SOL (stearoyl-oleoyl-linoleyl), SOO, POS/PSP, and SOS. Also, polymorphic form and x-ray diffraction of LTSF showed coexistence of $\beta$' and $\beta$ form crystals.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.21 no.2
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• pp.116-122
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• 2011

Human occupational exposure to n-hexane has been associated with neurobehavioral symptoms such as depression, irritablity, acute irritation symptom, concentration disturbance and fatigue. Effects of monoamine oxidase (MAO) B and serotonin transporter receptor (5-HTTR) polymorphisms on the neurobehavioral symptoms were investigated in 70 male workers from TV and computer monitor manufacturing plants exposed to n-hexane. Neurobehavioral symptoms were assessed through a self-reported questionnaire and ambient level of n-hexane was measured by NIOSH method. Blood and urine were collected from each workers to determine the MAO(B), 5-HTTR and urinary 2,5-hexanedione(2,5-HD). The mean concentration of volatile n-hexane was $18.8{\pm}28.8ppm$ and that of urinary 2,5-HD was $1.07{\pm}1.47mg/g$ creatinine. Statistically significant associations with sexual disturbance were age and smoking. The frequencies of MAO(B) AA, AG and GG were 18.6%, 45.7% and 35.7%, respectively, and the frequencies of 5-HTTR ll, ls and ss genotype were 82.9%, 15.7% and 1.4%, respectively. MAO (B) gene polymorphisms had susceptibility to the neurobehavioral symptoms such as fatigue, concentration disturbance, irritability and acute irritation symptom and 5-HTTR gene polymorphism had susceptibility to the sleep disturbance and acute irritation symptom. On multiple logistic regression analysis for the neurobehavioral symptoms, memory disturbance was significantly associated with smoking(OR=6.752, 95% CI=37.46) and drinking(OR=4.033, 95% CI=1.252-12.98), emotional lability was MAO(B) genotype(OR=0.412, 95% CI=0.170-0.996), fatigue (OR=1.011, 95% CI=1.000-1.021) and acute irritation(OR=0.990, 95% CI=0.981-1.000) were working duration and sexual disturbance were significantly associated with age(OR=1.208, 95% CI=1.042-1.399), ambient n-hexane(OR=1.077, 95% CI=1.005-1.154) and 2,5-HD(OR=0.186, 95% CI=0.041-0.841). This finding implies that the MAO (B) and 5-HTTR polymorphisms may affect susceptibility for specific neurobehavioral symptoms associated with n-hexane exposure in workers.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.8
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• pp.1113-1120
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• 2011

Enzymatic interesterification was conducted with the palm mid fraction (PMF) and stearic ethyl ester for 1, 5, and 9 hr at 46$^{\circ}C$. The reaction was catalyzed by Lipozyme TLIM (2, 3, and 4% by weight of total substrates) in a shaking water bath at 180 rpm. As the reaction continued, oleic acid (C18:1) content at the sn-2 position decreased, whereas saturated fatty acid (C16:0 and C18:0) content increased. In the high performance chromatography analysis, 1,3-dipalmitoyl-2-oleoyl glycerol content decreased, whereas 1(3)-palmitoyl-2-oleoyl-3(1)-stearoyl glycerol (POS) content increased up to the reaction equilibrium. The rate of acyl migration increased with increasing molar ratio and enzyme load as well as reaction time. The optimal reaction conditions for maximizing POS content (53.5 area%) and minimizing acyl migration (23.1 area%) were obtained with a PMF : stearic ethyl ester=1:2 (molar ratio), Lipozyme TLIM 3 wt%, and a reaction time of 5 hr.

• Korean Journal of Ecology and Environment
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• v.39 no.1 s.115
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• pp.1-12
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• 2006

Distributions of water temperature and DO profiles were investigated in Andong Reservoir from 1992 to 2004. Thermal stratification began to form from May of every year. Increasing water temperature of epilimnion, temperature difference between epilimnion and hypolimnion increased until August. Lower oxygen layer was formed at metalimnion from June or July of every year and there were 2 layers depending on each year. The two lower oxygen layers were affected by rainfall and inflow between July and September when thermal stratification was formed. The metalimnetic oxygen minima strongly formed at 2 layers, upper and lower part, when the average rainfall and inflow were ${\geqq}$ 170 mm, ${\geqq}$ 50 $m^3\;sec^{-1}$, respectively. It formed weakly when they were > 400 mm and > 200 $m^3\;sec^{-1}$ for one month. The upper part of low oxygen layers formed on the interface of epilimnion and metalimnion showed larger decreasing rate of DO than temperature and it disappeared around November. The lower part of those farmed on interface of metalimnion and hypolimnion existed until December and disappeared in January, this layer showed larger decreasing rate of temperature than DO. DO increased between the upper and lower part of the low oxygen layers. DO on hypolimnion increased under metalimnion and dramatically decreased near the bottom of the reservoir. Temperature of the inflow during rainy season was similar to that of the reservoir's metalimnion, DO was similar or higher and BOD, COD and SS increased. Density layer caused by turbidity was formed in metalimnion, and turbidity increased under the upper part (oxygen increasing layer) of metalimnetic DO minima layers reaching the maximum at the direct upper part of the lower DO minima layer. The upper part of DO minima layers formed on the interface of epilimnion and metalimnion is related to organic activity on the surface, and the lower part of those was considered to be the result of turbid water inflow to metalimnion during rainy season.