• Proceedings of the Membrane Society of Korea Conference
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• 2003.05a
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• pp.31-38
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• 2003

A pilot scale biofilter pretreatment-microfiltration system (BF-MF) was operated to investigate the effect of biofilter treatment in fouling reduction of microfiltration. Biofiltration was expected to reduce the membrane fouling by removal of turbidity and metal oxides. The hollow-fiber MF module with a nominal pore size of 0.1$\mu$m and a surface area of 8m$^2$ was submerged in a filtration tank and microfiltration was operated at a constant flux of 0.5 m/d. Biofiltration using polypropylene pellets was performed at a high filtration velocity of 320 m/d. Two experimental setups composed of MF and BF/MF, i.e., without and with biofilter pretreatment, were compared. Throughout the experimental period of 9 months, biofilter pretreatment was effective to reduce the membrane fouling, which was proved by the result of time variations of trans-membrane pressure and backwash conditions. The turbidity removal rate by biofiltration varied between 40% to 80% due to the periodic washing for biofilter contactor and raw water turbidity. In addition to turbidity, metals, especially Mn, Fe and Al were removed effectively with average removal rates of 89.2%, 67.8% and 64.9%, respectively. Further analysis of foulants on the used membranes revealed that turbidity and metal removal by biofiltration was the major effect of biofiltration pretreatment against microfiltration fouling.

• The Korea Journal of Herbology
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• v.30 no.4
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• pp.71-79
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• 2015

Objectives : These present study was designed to investigate the relaxation effects of Alpiniae Oxyphyllae Fructus(AOF) on isolated corpus cavernosum smooth muscle.Methods : Rabbit corpus cavernous tissues were prepared in strip. Then relaxation responses of AOF at 0.01-3 ㎎/㎖ in contracted strips induced by phenylephrine(PE) were measured. To evaluate mechanisms, indomethacin(IM) tetraethylammonium chloride(TEA), Nω-nitro-L-arginine(_L-NNA), methylene blue(MB) were treated before AOF extract(0.1-3 ㎎/㎖) infused into precontracted strips induced by PE. And 1 mM Ca²⁺was infused into precontracted strips after pretreatment of AOF extract(3 ㎎/㎖) in Ca²⁺-free krebs-ringer solution. NO concentration was measured by Griess reagent system. Ratio of smooth muscles to collagen fibers and eNOS positive reaction were measured by histocheminal and immunohistochemical process.Results : The cavernous strips were significantly relaxed by AOF extract 0.1, 0.3, 1, 3 ㎎/㎖ and the pretreatment with IM 10 μM,_L-NNA 100 μM, MB 10 μM inhibited relaxation of AOF compared to non-pretreatment, but the pretreatment with TEA 100 μM didn't affect relaxation of AOF. In a Ca²⁺-free solution, pretreatment with AOF reduced increase on contraction of strips by Ca²⁺supply than non-pretreatment. On HUVEC, NO concentration was increased. On corpus cavernosum of penis in Spontaneous Hypertensive Rat, ratio of smooth muscles to collagen fibers and eNOS positive reaction in AOF group were increased compared to PE groupConclusions : Taken this results, we can suggest that AOF extract exerts a relaxation effects on rabbit corpus cavernosum smooth muscle in part by suppressing influx of extracellular Ca²⁺throughout prostacyclin, the NO-cGMP system.

• Preventive Nutrition and Food Science
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• v.14 no.2
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• pp.95-101
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• 2009

In this study, we assessed the effects of Se-methylselenocysteine (MSC) pretreatment on the antioxidant system in the pancreas and the development of alloxan-induced diabetes in rats. The rats were treated with MSC at a dose of 0.75 mg/rat/day for 2 weeks. The MSC-treated rats evidenced significantly increased glutathione content, GSH/GSSG ratio, and glutathione peroxidase (GPx) and glutathione reductase (GRd) activities in the pancreas. Diabetes was induced via alloxan injection. The alloxan-diabetic rats evidenced significantly reduced glutathione content and glucose 6-phosphate dehydrogenase (G6PD) activity and increased catalase activity in the pancreas, when measured 3 days after the alloxan injection. 2-week MSC pretreatment was shown to prevent the alloxan-induced hyperglycemia as well as changes in glutathione content, G6PD activity, and catalase activity. The results of this study indicate that the prevention of alloxan-diabetes by MSC pretreatment is associated with its effects on antioxidants in the pancreas, namely, the increase in cellular content and the reduction of glutathione by the facilitation of glutathione recycling induced via increased GPx, GRd, and G6PD activities.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.14 no.1
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• pp.23-29
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• 2008

The market sales of fresh-cut fruit and vegetables have grown rapidly in recent decades as a result of changes in consumer trend. Choosing the proper pretreatment of fruit and vegetables before minimally processing is very important because appearance is the most fundamental factors affecting the quality of fresh-cut products. This review describes the biochemical bases for color changes of fruit and vegetables including browning, discoloration, and color changes of carrots and alliums. Understanding pathway of pigments in minimally processed fruit and vegetable and preventing the way of color change should be emphasized for successive packaging system. This review also describes pretreatment of fresh-cut fruit and vegetables to improve the prolonging the shelf-life and maintenance of its qualities.

• Bulletin of the Korean Chemical Society
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• v.28 no.1
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• pp.59-62
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• 2007

A quantitative analysis method of halogen elements in volatile organohalogen compounds was established by the Wickbold combustion pretreatment in an enclosed system and ion chromatography. The sample pretreatment parameters of Wickbold combustion were experimentally optimized, and using the determined optimal pretreatment parameters, the reproducibility was estimated by ion chromatography. As a comparison for real samples, NIST certified reference materials (CRMs) were analyzed for the recovery efficiency and reproducibility.

• 한국전산유체공학회:학술대회논문집
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• 2008.03b
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• pp.260-263
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• 2008

KEPCO(Korea Electric Power Corporation) is performing the nation's first biogas-MGT project as an effort to encourage the utilization of wasted biogas which contains useful CH4. The goals of this project are to develop the Pretreatment system of Livestock bio-gas and set up the biogas-MGT co-generation system. The project will not only utilze flared biogas as precious energy but also improve the economics of the plant a lot. The pretreatment system mainly consists of sulfur removal tower, biogas compressor and many filtering systems. A computational fluid dynamics study in the bio gas sulfur removal tower and sulfur absorption filter was carried out. Understanding of the flow in the sulfur removal tower and sulfur adsorption filter obtained by this study can be used to identify the problems in the sulfur removal tower and to improve the sulfur removal efficiency of the sulfur removal tower. Resistance material modeling is used to simulate the sulfur adsorption filter, and the resistance coefficient was adjusted to reflect the experimental pressure loss value. And the pressure loss change with the flowrate is predicted

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2002.05b
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• pp.471-474
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• 2002

SA treatment significantly increased thermotolerance In cucumber seedlings. Pretreatment of seeds with $CaCl_2$ solution enhanced the SA- induced thermotolerance. On the contrary, pretreatment with the $Ca^{2+}$ chelator EGTA lowered this SA-induced thermotolerance. In addition, pretreatment with $Ca^{2+}$ channel blocker verapamil also weakened the SA-induced thermotolerance. However, the calmodulin antagonist chlorpromazine(CPZ) had little effect on the SA-induced thermotolerance. Measurement of activity of the antioxidant enzyme APX and the level of lipid peroxidation (in term of MDA) indicated that heat stress induced an oxidative stress in cucumber seedlings. SA treatment induced higher activities of APX and a lower level of lipid peroxidation. $Ca^{2+}$ pretreatment further enhanced the SA-induced increase in APX activity and lowered the heat stress-induced lipid peroxidation, but EGTA pretreatment had a contrary effect. These results suggest that $Ca^{2+}$ and calmodulin may be involved In the acquisition of the SA-induced thermotolerance; antioxidant enzyme system take part in the final generation of the SA-induced thermotolerance.

• The Korean Journal of Pharmacology
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• v.14 no.1_2
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• pp.55-62
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• 1978

Ban formulated the concept of 'sympathetic center' and 'parasympathetic center' in the central nervous system, and Folkow et al. reported that the electric stimulation of the posterior part of hypothalamus induced the marked liberation of catecholamines from the adrenal medulla. Tatum reported that the hyperglycemic action of picrotoxin is contributed to the cathecholamines liberation from adrenal medulla by the excitation of hypothalamus via splanchnic nervous plexus. In this paper, the relationship between the convulsive action and the hyperglycemic effect of picrotoxin was investigated, with references to the influences of several drugs related with adrenergic function and two intravenous anesthetics on the picrotoxin hyperglycemia. The results obtained were summarized as follows; 1) There was no difference between the convulsive dose(1. 5mg/kg) and the subconvulsive dose (0.75mg/kg) of picrotoxin in its hyperglycemic effect that was not affected with the phenobarbital pretreatment, but the efficacy of its hyperglycemic action was more prominent than that of strychnine. 2) The hyperglycemic effect of picrotoxin was markedly suppressed by the pretreatment of thiopental or ketamine. 3) The hyperglycemic effect was not affected by the reserpine pretreatment, but the effect was markedly suppressed by the pretreatment of iproniazid or chlorpromazine. 4) The hyperglycemic effect of picrotoxin was significantly suppressed by the pretreatment of hexamethonium, propranolol or guanethidine, and the order of those suppressing efficacy was propranolol> hexamethonium> guanethidine.

• Radiation Oncology Journal
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• v.38 no.1
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• pp.60-67
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• 2020

Purpose: We performed three-dimensional (3D) dose reconstruction-based pretreatment verification to evaluate gamma analysis acceptance criteria in volumetric modulated arc therapy (VMAT) for prostate cancer. Materials and Methods: Pretreatment verification for 28 VMAT plans for prostate cancer was performed using the COMPASS system with a dolphin detector. The 3D reconstructed dose distribution of the treatment planning system calculation (TC) was compared with that of COMPASS independent calculation (CC) and COMPASS reconstruction from the dolphin detector measurement (CR). Gamma results (gamma failure rate and average gamma value [GFR and γAvg]) and dose-volume histogram (DVH) deviations, 98%, 2% and mean dose-volume difference (DD_98%, DD_2% and DD_mean), were evaluated. Gamma analyses were performed with two acceptance criteria, 2%/2 mm and 3%/3 mm. Results: The GFR in 2%/2 mm criteria were less than 8%, and those in 3%/3 mm criteria were less than 1% for all structures in comparisons between TC, CC, and CR. In the comparison between TC and CR, GFR and γAvg in 2%/2 mm criteria were significantly higher than those in 3%/3 mm criteria. The DVH deviations were within 2%, except for DD_mean (%) for rectum and bladder. Conclusions: The 3%/3 mm criteria were not strict enough to identify any discrepancies between planned and measured doses, and DVH deviations were less than 2% in most parameters. Therefore, gamma criteria of 2%/2 mm and DVH related parameters could be a useful tool for pretreatment verification for VMAT in prostate cancer.

• Corrosion Science and Technology
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• v.6 no.5
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• pp.239-244
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• 2007

Corrosion protection of automotive steels has traditionally been assured by using a zinc phosphate metal pretreatment followed by the deposition of a cathodic electrocoat system. This system has been developed and optimized over the years into a highly robust and dependable system with a high performance. However, in terms of efficiency and use of resources and energy, the need is now felt to develop a simpler system with fewer steps, shorter lines, less energy requirements (curing and e-coat deposition) and less stringent waste disposal requirement (phosphate sludge). We report here on the development of a one-step system that can possibly replace both the zinc phosphate and the e-coating processes. Such a system is based on the so-called superprimer concept that we have recently developed for the replacement of chromate pretreatment and chromate-containing primers in the aerospace industry. With some modifications, such systems can also be adapted for use in the automotive industry.