• Korean Journal of Food Science and Technology
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• v.24 no.4
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• pp.306-310
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• 1992

The effects of membrane type, temperature and pH on the permeate flux and removal of soluble solids from soybean curd whey by reverse osmosis were studied at recommended pressures for optimum performance of the membranes. The fluxes obtained with HR 95 and HR 98 membranes at 60 bar were not lower than that with CA 930 membrane at 20 bar. Soluble solid content in the permeate increased to 1.5 Brix after 90 min by CA 930 membrane, as opposed to 0 Brix with the HR 95 and HR 98 membranes. Permeate flux was increased by 28.4% as operation temperature increased from $30^{\circ}C$ to $50^{\circ}C$. COD of the whey was rejected up to 80.5%, 99.7% and 99.5% by using the membranes of CA 930, HR 95 and HR 98, respectively. pH adjustment of the whey resulted in decreasing membrane performance. But the rejection rate of COD in permeate with HR 98 membrane was slightly increased to 99.9% when the pH was adjusted to 7.0.

• Journal of the Korean Society of Radiology
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• v.17 no.1
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• pp.53-62
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• 2023

The purpose of this study is to find an optimized imaging technique and evaluate its usefulness by comparing and analyzing the difference in contrast enhancement of lower extremity artery according to the patient's heart rate during lower extremity Computed Tomography Angiography examination. From January 2022 to August 22nd, 139 outpatients who visited Ajou University Hospital and underwent lower extremity angio CT examination were targeted. According to the heart rate, the groups were divided into four groups: A(HR ≤65), B(65 < HR < 80), C(80≤ HR). In addition, among patients with a heart rate of 65 or less, the heart rate was considered, and the scan was divided into D, E, F group with a delay time. The time of arrival of contrast medium and the average value of contrast enhancement were compared and analyzed. As a result of quantitative evaluation, B and C groups with a heart rate of more than 65 times had better HU values in the popliteal artery than A group (HR ≤ 65), and D group showed better HU improvement effects compared to A group (p<0.001). The comparative analysis with other groups was insignificant. The difference in heart rate affected the angiographic intensity of the lower extremities artery. Therefore, it is effective to apply the appropriate test timing for each patient by using the heart rate during the lower extremity angio CT Scan.

• KSBB Journal
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• v.4 no.3
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• pp.241-245
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• 1989

A carriersupported mycelial growth of Sreptomyces erythreus was applied to erythromycin fermentation sistem using celite as a support material. Hyphal growth through the pore matrices of the materials showed anchorages and provided a stable biofilm growth. When the phospate concentration was limited to 0.8g corn steep liquor/L(corresponding to 40mg KH2PO4/L), the specific production rate of erythromycin was increased from 557$\mu$g/g-cell.hr under unlimited condition to 2, 898 $\mu$g/g-cell.hr. A fluidized-bed bioreactor was operated for erythromycin production by a repeated fed-batch mode. The control of free mycelial concentration and the extension of production phase were considered important to maintain the reactor productivity at a desired level. The erythromycin production under phosphate-limited condition could be maintained for at least 600hrs.

• Microbiology and Biotechnology Letters
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• v.20 no.2
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• pp.196-202
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• 1992

Zoogloea ramigera 115 was selected for the production of viscous microbial polysaccharide for bioflocculants usage. Batch, fed-batch, and continuous culture processes were examined with regard to the high biopolymer production. Several carbon sources were tested, including glucose, lactose, molasses, and cheese whey. The C/N ratio of 90 was most effective for biopolymer production from glucose, while the C/N ratios of 30 for lactose and 60 for both molasses and cheese whey substrate gave a maximum production. Fed batch culture proved more effective to increase final biopolymer concentration than batch culture. Continuous fermentation with two stages modifying C/N ratio increased the productivity. The production rates were a maximum at dilution rate of 0.048 $hr^{-1}$ for molasses and at 0.096 $hr^{-1}$for cheese whey.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.05a
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• pp.564-567
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• 2012

Optical fibers are going to be used for telecommunication, image fibers, sensors under irradiation in nuclear power plants and various irradiation facilities. Especially, Temperature detection sensors using Raman light scattering, temperature or strain sensors using fiber gratings, magnet-optical sensors using photo-magnetic effect, are already commercialized. However, When fibers are exposed to ionizing radiation, color centers are formed in fibers which reduces their light transmission, and it is limited in applying under radiation environments. In this study, $Co^{60}$ gamma-ray induced optical attenuation on Ge-doped single mode(SM) fiber has been measured. Gamma-ray is irradiated for 4hours at the dose rate of 0.5kGy/hr, 2kGy/hr, 8kGy/hr. Consequently, gamma-ray induced loss based on radiation effects in Ge-doped SM fiber occur precisely. Furthermore, dose rate effect that the higher dose rate in the same total dose, the more increase loss of optical fiber and annealing effect that the higher the loss after irradiation, the more increase the recovery rate of the loss are observed in the fiber. This results plan to make use of bases in the study of the radiation-hardened optical fiber.

• Proceedings of the Korean Nuclear Society Conference
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• 1996.05c
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• pp.513-518
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• 1996

저농도 방사성 액체폐기물의 최종 처리를 목적으로 본 연구에서는 면 35%와 Polyester 65%가 함유된 합성섬유를 증발매체로 하여 자연상태의 공기를 강제 송풍시키는 자연증발처리시설에서 증발에 영향을 미치는 주요 변수에 따라 증발 단위 면적당 Cs-137, Co-60을 함유한 방사성 폐액의 증발량측정 및 제염계수를 조사하였다. 증발효과는 유입공기의 습도가 낮고, 공기의 유속과 공급액의 유량이 증가하고 유입공기 및 폐액의 온도가 높아질수록 증발량이 증가하였다. 실험결과 유입된 공기는 1$0^{\circ}C$ 이상, 습도는 80% 이하, 공급폐액의 유량이 3.4 $\ell$/hr $m^2$ 이상, 공기유속은 1.14~l.47 m/sec 범위가 조업조건이며 이때 제염계수는 5.1 $\times$ $10^3$, 배출공기의 방사능 농도는 4.7$\times$$10^{-13}$ $\mu$Ci/$m\ell$ air로 측정되었다. 공급유량이 4.6$\ell$/hr.$m^2$와 공기유속이 1.47 m,/sec일때 최대 증발조건으로 나타났으며, 이때 증발량은 총 증발면적 11,250$m^2$ 에서 1.2 ㎥/hr로 측정되었으며 대기의 온.습도 및 풍속에 따른 실험을 통하여 달톤형 증발식의 Wind Factor ［Eh ＝ (0.0168 ＋ 0.0141V)$\Delta$H］를 도출하였다.

• Journal of Wetlands Research
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• v.6 no.4
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• pp.59-69
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• 2004

Constructed wetlands are regarded as an important water treatment system for agricultural water quality improvement and management. The purpose of this study is to evaluate the application of subsurface flow wetland(SFW), using the Pharagmites australis as macrophytes, and to clarify the basic and essential factors to be considered in the construction and management of constructed wetlands. This study was carried out relatively short hydraulic residence time(HRT), 6hr ~ 72hr (3days), using eutrophic reservoir water with relatively low concentrations of influent and large quantity to be treated. The effluent satisfied the criteria of agricultural water quality. Removal efficiencies of Biochemical oxygen demand(BOD), Chemical oxygen demand(COD), Suspended solids(SS) and Chlorophyll a(Chl-a) were high in HRT 24hr, not any more significant increasement of removal efficiencies in HRT 48hr and 72hr. However, removal efficiencies of nitrogen and phosphorus increased as HRT increased, showing the highest efficiency at the 72hr of HRT in nitrogen, and 48hr in phosphorous. The SFW was very effective system for reservoir water quality improvement, and had the advantages of the reduction of purchasing cost to land required, lack of odors, and harmful insects, especially mosquito, the improvement of the scenic beauty and minimal risk of public exposure. Therefore, it was evaluated that the SFW was very available water treatment system for the water quality improvement of agricultural reservoir. However, it was need to consider with application of the SFW in high cost of construction and troublesome of management.

• Korean Journal of Food Science and Technology
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• v.52 no.4
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• pp.369-376
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• 2020

The purpose of this study was to evaluate the antioxidant components and activities of HR02/04(8:2)-W, a mixture of S. quelpaertensis Nakai and F. erecta var. sieboldii. We investigated the p-coumaric acid, total flavonoid, and total phenol contents. To evaluate the antioxidant efficacy, we measured the 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzthiazoline6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity, FRAP activity, reducing power, and ORAC value. We observed the protective effect of hydrogen peroxide against cell damage in human dermal fibroblasts. As a result of the experiment, the p-coumaric acid, total flavonoid, and total phenol contents were 75.62±1.56 mg/100 g, 21.57±0.84 mg rutin equivalent (RE)/g, and 21.25±1.31 mg gallic acid equivalent (GAE)/g, respectively. In the experiments on antioxidant activity, HR02/04(8:2)-W was found to have significantly increased antioxidant activity. In the human dermal fibroblasts, the HR02/04(8:2)-W treated groups could effectively protect cells against oxidative damage. In this study, we confirmed that HR02/04(8:2)-W is a material with effective physiological antioxidant activity.

• Food Science and Preservation
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• v.15 no.2
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• pp.236-242
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• 2008

We investigated the optimum concentration of a $NaClO_2$ solution and the amount of gaseous $Cl_2$ for production of high yield and purity of aqueous $ClO_2$ by use of a gaseous chlorine-chlorite $ClO_2$ generator. This system produced lower concentrations of chlorine dioxide and is applicable for direct-use in food processing as a cleaner and sanitizer. The concentration of $NaClO_2$ solution and the amount of gaseous $Cl_2$ was varied from 0.01-0.1% and 100-1,000 g/hr, respectively. The concentrations of chlorite, chlorate, FAC (free available chlorine), and chlorine dioxide that were produced increased with increasing concentration of $NaClO_2$ solution and with the amount of gaseous $Cl_2$. The optimum concentration of $NaClO_2$ solution and amount of gaseous $Cl_2$ were 0.1% and 900 g/hr respectively. $ClO_2$ and FAC produced at these concentrations were 882.0 ppm and 8.0 ppm, with no detection of chlorite and chlorate. The yield and purity of $ClO_2$ were 97.0% and 96.0% respectively. Immersion-cleaning experiments showed that this protocol decreased the level of CFU/g by $10^3$- to $10^4$-fold, with a similar effect on fruit.

• Journal of Ginseng Research
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• v.16 no.1
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• pp.13-17
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• 1992

The present experiments were performed to investigate the effects of the ginseng total saponin on the development of physical dependence on morphine via intracerebroventricular (i.c.v) route. Morphine (10 $\mu\textrm{g}$/${mu}ell$/hr) was continuously infused via osmotic minipumps into lateral cerebral ventricle of male Sprague Dawley rats for 7 days. Concurrent ginseng total saponin (100, 200 $\mu\textrm{g}$/10${mu}ell$/hr) was infused intraperitoneally (i.p) via osmotic pumps for 7 days. Treatment with ginseng total saponin (200$\mu\textrm{g}$/10${mu}ell$/hr) significantly diminished jumping, teeth chattering, hypothermia and weight loss precipitated by naloxone, compared with those animals received only morphine infusion. These results suggest that ginseng total saponin has central effect on the inhibition of physical dependence on morphine, as systemic ginseng total saponin inhibits the development of physical dependence in rats infused with morphine intracerebroventricularly.