• Journal of Applied Biological Chemistry
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• v.65 no.3
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• pp.173-181
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• 2022

This study was carried out to investigate the residual characteristics of flubendiamide in kale to establish pre-harvest residue limits (PHRL) and the removal efficiency according to the washing solvent and method. Field tests were conducted at two different greenhouses, field 1 (Anseong-si, Gyeonggi-do) and field 2 (Incheon-si, Gyeonggi-do). According to the safe use guidelines kale was sprayed with flubendiamide twice every 10 days and harvested 0 (after 2 h), 1, 2, 3, 5, 7 and 10 days after the final application. The biological half-live of flubendiamide in kale was calculated based on dissipation curves of the pesticide in samples analyzed by liquid chromatography coupled with tandem mass spectrometry. In the analysis, method limits of quantitation (MLOQ) were 0.01 mg/kg, and recoveries performed with two different fortification levels of 10 MLOQ and maximum residue limit (0.7 mg/kg) were 104.2±3.6 and 101.9±10.2%, respectively. The dissipation rate constant of flubendiamide in kales were 0.2437 at field 1 and 0.1981 at field 2. PHRL calculation equations obtained using the dissipation constants estimated as follows: if the residual concentration of flubendiamide in kale on 10 days before harvest is less than 8.0 mg/kg, the residual concentration on the harvest would be under MRL. The removal of flubendiamide from kale was the greatest when it was washed with vinegar (39.8%), followed by baking soda (31.7%), calcium powder (30.2%), neutral detergent (27.2%), and tap water (15.9%). The results of this study would be useful for both farmers and consumers to produce or consume safe agricultural products.

• Korean Journal of Food Science and Technology
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• v.33 no.6
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• pp.656-663
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• 2001

The most representative nitrosamine derived from nicotine, nitrosamine-4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone(NNK), has been reported to cause lung cancer in A/J mice. It has been also demonstrated that NNK-induced lung tumorigenesis involves $O^6-methylguanine(O^6MeG)$ formation, leading to $GC\;{\rightarrow}\;AT$ transitional mispairing during DNA replication. Our in vitro experiment, modified from the method of DBA assay, examined the ability of phyto-extract mixture to inhibit the metabolism of nicotine to nitrosamines. The production of nitromorpholine from morpholine was inhibited about 75% at the concentration of 20 mg/mL of phyto-extract mixture, which was lower than vitamine C and green tea powder. NNK, which is a pro-carcinogen in laboratory animals, is hydroxylated primarily in liver and lung by CYP 1A2, 2A6 and 3A4. A critical phase. of NNK activation is its change to an unstable metabolite methyl-diazohydroxide via CYP-mediated ${\alpha}-hydroxylation$; and then it provides a methyl group to the DNA to form DNA adducts which can easily induce mutations. $Aroclor^R$ 1254 was used to induce CYPs in the liver of a Sprague-Dawley rat. The ability of various test samples to inhibit CYPs that participate in NNK activation was evaluated, following the removal of the liver from the rat. Microsomal CYPlA2 catalyzing the conversion of NNK into strong carcinogenic chemicals was inhibited more efficiently by phyto-extract mixture than green tea powder. These results indicate that phyto-extract mixture can be used to reduce $O^6MeG$ DNA adducts for chemoprevention.

• Journal of the Korea Organic Resources Recycling Association
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• v.32 no.3
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• pp.43-56
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• 2024

In this study, we investigate wet absorption process and the performance and regeneration of Fe(II)EDTA^2- absorbents, electrodeposition of the reducing agent for recovery of metal powder and re-absorption performance using regenerated absorbed for the simultaneous removal of nitrogen oxides (NO) and sulfur oxides (SO₂) emitted from flue gas. As a result of a simultaneous absorption experiment of NO and SO₂ under the presence of oxygen, the antagonistic effects of SO₂ and O₂ in the absorption solution resulted in the regeneration of Fe(III)EDTA^- and Fe(II)EDTA-NO^2- to Fe(II)EDTA^2-, inducing the maintained neutral pH and maintained NO₂ absorption, thereby greatly improving the simultaneous absorption performance of NO and SO₂. In addition, after regenerating the Fe(II)EDTA^2- absorbent with Zn metal powder as a reducing agent, electrodeposition was performed to recover the remaining reducing agent. During the electrodeposition process, the high Zn recovery efficiency (approximately 57.50%) was observed at an applied voltage of 4 V, and the total absorption amount of NO was also significantly improved.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.5
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• pp.455-462
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• 2000

The objective of this study was to examine the physicochemical characteristics of coagulation reaction between loess and red tide organisms (RTO) and its feasibility, in developing a technology for the removal of RTO bloom in coastal sea. The physicochemical characteristics of loess were examined for a particle size distribution, surface characteristics by scanning electron microscope, zeta potential, and alkalinity and pH variations in sea water. Two kinds of RTO that were used in this study, Cylindrothen closterium and Skeietonema costatum, were sampled in Masan bay and were cultured in laboratory. Coagulation experiments were conducted using various concentrations of loess, RTO, and a jar tester. The supernatant and RTO culture solution were analyzed for pH, alkalinity, RTO cell number. A negative zeta potential of loess increased with increasing pH at $10^(-3)M$ NaCl solution and had -71.3 mV at pH 9.36. Loess had a positive zeta potential of +1,8 mV at pH 1.98, which resulted in a characteristic of material having an amphoteric surface charge. In NaCl and $CaCl_2$, solutions, loess had a decreasing negative zeta potential with increasing $Na^+\;and\;Ca^(+2)$ ion concentration and then didn't result in a charge reversal due to not occurring specific adsorption for $Na^+$ ion while resulted in a charge reversal due to occurring specific adsorption for $Ca^(+2)$ ion. In sea water, loess and RTO showed the similar zeta potential values of -112,1 and -9.2 mV, respectively and sea sand powder showed the highest zeta potential value of -25.7 mV in the clays. EDLs (electrical double-layers) of loess and RTO were extremely compressed due to high concentration of salts included in sea water, As a result, there didn't almost exist EDL repulsive force between loess and RTO approaching each other and then LVDW (London-yan der Waals) attractive force was always larger than EDL repulsive force to easily form a floe. Removal rates of RTO exponentially increased with increasing a loess concentration. The removal rates steeply increased until $800 mg/l$ of loess, and reached $100{\%}$ at 6,400 mg/l of loess. Removal rates of RTO exponentially increased with increasing a G-value. This indicated that mixing (i.e., collision among particles) was very important for a coagulation reaction. Loess showed the highest RTO removal rates in the clays.

• Applied Chemistry for Engineering
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• v.18 no.3
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• pp.273-278
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• 2007

The honeycomb adsorbents and adsorption process for carbon dioxide removal from fuel gas were investigated. Zeolite paper was made with Na-X zeolite powder and ceramic fiber as raw materials. $Li^+$, $Ca^{2+}$ or $K^+$ ion exchanges for Na-X zeolite and additional Na-X coating were performed on zeolite paper for increasing the carbon dioxide adsorption capacity, after that the adsorption characteristics of the samples were analyzed. Among the ion exchanged samples, $Li^+$ ion exchanged zeolite paper was most promising but its carbon dioxide adsorption capacity was less than expected for process application. However, additional Na-X coating was found to be an effective method for increasing the carbon dioxide adsorption capacity of the zeolite paper for process application. The carbon dioxide breakthrough test of the honeycomb adsorbent prepared with the zeolite paper was studied, and fuel gas treatment capacity was calculated when the honeycomb adsorbent was used in the rotary adsorption process.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.14 no.3
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• pp.123-128
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• 2004

Both photoluminescence and the long-phosphorescent properties for $SrAl_2O_4$ : Eu$^{+2}$, $Dy^{+3}$ phosphor powder synthesized by the solid phase reaction were investigated as a function of $B_2O_3$ composition (0-10 wt%). The highest emission wavelength (520nm) of photoluminescence spectra was not affected by $B_2O_3$concentration. The highest emission intensity was obtained by the concentration of 3 wt% $B_2O_3$.After the removal of the Xenon lamp excitation (360nm), also, the excellent long-phosphorescent property of the phosphors was obtained by the concentration of 3 wt% $B_2O_3$ although the decay times for all phosphors decreased exponentially.

• Journal of Korean Society of Water and Wastewater
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• v.9 no.4
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• pp.87-96
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• 1995

The Electron/Hole Pair is generated when the activation energy produced by ultraviolet ray illuminates to the semiconductor and OH- ion produced by water photocleavage reacts with positive Hole. As a results, OH radical acting as strong oxidant is generated and then Photocatalytic oxidation reaction occurs. The photocatalytic oxidation can oxidate the non-degradable and hazardous organic substances such as pesticides and aromatic materials easier, safer and shorter than conventional water treatment process. So in this study, many factors influencing the oxidation of chlorophenols, such as inorganic electrolytes addition, change of oxygen and nitrogen atmosphere, temperature, pH, oxygen concentration, chlorophenol concentration, were throughly examined. According to the experiments observations, it is founded that the rate of chlorophenol oxidation follows a first-order reaction and the modified Langmuir-Hinshelwood relationship. And the photocatalytic oxidation occurs only when activation energy acting as Electron/Hole generation, oxygen acting as electron acceptor to prevent Electron/Hole recombination, $TiO_2$ powder acting as photocatalyst are present. The effects of variation of dissolved oxygen concentration, temperature and inorganic electrolytes concentration on 2-chlorophenol oxidation are negligible. And the lower the organic concentration, the higher the oxidation efficiency becomes. Therefore, the photocatalytic oxidation is much effective to oxidation of hazardous substances at very low concentration. The oxidation is effective in the range of 0.1 g/L-10 g/L of $TiO_2$. Finally when the ultra-violet ray is illuminated to $TiO_2$, the surface characteristics of $TiO_2$ change and Adsorption/Desorption reaction on $TiO_2$ surface occurs.

• Journal of Chest Surgery
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• v.24 no.6
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• pp.570-578
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• 1991

The spontaneous pneumothorax is the sudden collapse of the lung usually by air leakage from the ruptured sub-pleural bleb and has high recurrence rate. For prevention against recurrence, many drugs such as tetracycline, talcum powder, quinacrine, etc. have been used but the effects are not satisfactory. We reduced the recurrence rate successfully by the fibrin glue instillation through the chest tube. From the January 1989 to September 1990, we have managed 65 patients of spontaneous pneumothorax with closed thoracostomy and fibrin glue[fibrinogen 1gm/50ml with approtinin 3, 000kIU /ml, thrombin 5, 000IU /ml in 3% each 10ml] instillation through the chest tube. And we compared the results with those of 106 patients of spontaneous pneumothorax who were managed only by the closed thoracostomy from January 1985 to December 1988. Only the patients who visited our hospital with recurrence were considered as the recurred cases but the others were considered as not recurred. And the removal of chest tubes usually done 3 days after cessation of air leakage or 2 days after fibrin glue instillation Statistical analysis was done by X2-test. The results were as followings: 1. The recurrence rate of fibrin glue instillation group was lower than that of non-instillation group[1st attack: 15.1% versus 27.6% p<0, 05, the 2nd attack: 33.3% versus 73.7% p<0.01, the total 18.5% versus 35.8% p<0.01]. 2. The mean duration of chest tube drainage in the fibrin glue instillation group was shorter than non-instillation group[4.24$\pm$1.36 days versus 4.48$\pm$1.73 days p<0.05]. 3. The mean duration of hospitalization was shorter in the instillation group [8.12$\pm$3.5 days versus 10.8$\pm$3.8 days p<0.05] The complications were transient mild fever, chest pain, pleural effusion in 46 cases of 65 patients, but those didn`t make any problem. We concluded that the fibrin glue is effective in the reduction of recurrence rate, obliteration of air leakage and duration of hospitalization.

• Korean Chemical Engineering Research
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• v.47 no.6
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• pp.688-694
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• 2009

A spray-type cleaning agent in utilizing dust-remover on PCB was chosen to study the cleanliness test and efficiency. In order to choose alternative environmental-friendly cleaning agents, it is important that the systematic selection procedures should be introduced and applied through the evaluation of their cleaning ability, environmental characteristics, and economical factors, and that the objective and effective evaluation methods of cleanliness should be established for the industry. A novel cleaning evaluation method with scanning electron microscopy/energy-dispersive X-ray analysis of surface observation evaluation method and an infra-red thermography camera(THERMOVISION A20 model) was studied in this work. The sound card(CT-2770 model) cut by $2{\times}2cm$ size was used as a part, and before and after the spray cleaning, the cleanliness was observed by the image analyzer of SEM and further the removal efficiency of dust was quantitatively evaluated by the component analysis of EDX. For the parts of P4TE model motherboard and IPC-A-36 PCB plate, before and after the spray cleaning, temperature differences were measured and compared at room temperature and 50 oven temperature by an infra-red thermography camera in the contaminants of dust and iron powder.

• The Korean Journal of Food And Nutrition
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• v.22 no.1
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• pp.8-13
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• 2009

Effects of microwave and ultrasonication on chitin extraction time were investigated in this study. Chitin was extracted from ground crab shell by demineralization in 1.0 N HCl solution at 25$^{\circ}C$ with or without ultrasonication and deproteinization in 1.0 NaOH solution at 100$^{\circ}C$ without ultrasonication and at 70$^{\circ}C$ with ultrasonication. Microwave treatment was also used for deproteinization with 5 min heating and 5 min standing without microwave. The changes in color difference, the contents of ash, calcium and nitrogen were measured during demineralization and deproteinization. Ultrasonication of 4 hr in 1.0 N HCl solution for removal of calcium and 1.5 hr of microwave heating in 1.0 N NaOH for deproteinization corresponded to 6 hr in 0.1 N HCl and 2 hr in 1.0 N NaOH of heating at 100$^{\circ}C$ without those treatments, respectively. The data obtained showed that these treatments were effective reduction of chitin extraction time by 25${\sim}$33% for chitin preparation. The chitin obtained from these ultrasonication and microwave treatments resulted 0.55% of ash, 0.25% of calcium, 2.47% of nitrogen and 20.64% of yield ratio. Those treatments selected were also reduced the darkness development time of the chitin solution during demineralization and deproteinization.