• Journal of Korean Society of Water and Wastewater
• /
• v.34 no.3
• /
• pp.183-190
• /
• 2020

Although membrane bio-reactor (MBR) has been widely applied for wastewater treatment plants, the membrane fouling problems are still considered as an obstacle to overcome. Thus, many studies and commercial developments on mitigating membrane fouling in MBR have been carried out. Recently, high voltage impulse (HVI) has gained attention for a possible alternative technique for desalting, non-thermal sterilization, bromate-free disinfection and mitigation of membrane fouling. In this study, it was verified if the HVI could be used for mitigation of membrane fouling, particularly the internal pore fouling in MBR. The HVI was applied to the fouled membrane under different conditions of electric fields (E) and contact time (t) of HVI in order to investigate how much of internal pore fouling was reduced. The internal pore fouling resistance (R_f) after HVI induction was reduced as both E and t increased. For example, R_f decreased by 19% when the applied E was 5 kV/cm and t was 80 min. However, the R_f decreased by 71% as the E increased to 15 kV/cm under the same contact time. The correlation between E and t that needed for 20% of R_f reduction was modeled based on kinetics. The model equation, E^1.54t = 1.2 × 10³ was obtained by the membrane filtration data that were obtained with and without HVI induction. The equation states the products of En and t is always constant, which means that the required contact time can be reduced in accordance with the increase of E.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.23 no.4
• /
• pp.59-64
• /
• 2023

In this paper, It is proposed through the empirical design of a Conducted EMI filter for noise reduction of power used in electronic devices. For the proposed structure, A-type, B-type, C-type, and D-type structures were designed, and conductive noise reduction was confirmed by using an LC network with various X-capacitors, Y-capacitors, and Air-inductors. 10 [μH] was used for L1 and L2, and 4.7 [nF] was used for C1 and C2. L3 for common mode used 13[μH], and C5, C6, C7 were designed using 10[nF]. The measured insertion loss values of the designed EMI filter were -74.4[dB] at 3.2MHz, -75.4[dB] at 4MHz, and -75.3[dB] at 13.56MHz. Therefore, the proposed EMI filter will be able to reduce power supply noise used in various electronic devices.

• Molecules and Cells
• /
• v.21 no.3
• /
• pp.356-359
• /
• 2006

The transcription factor E2F1 coordinates cell cycle progression and induces apoptosis in response to DNA damage stress. Aside from DNA damage, the role of E2F1 in the endoplasmic reticulum (ER) stress signaling pathways is unclear. We found that $E2F1^{-/-}$ murine embryonic fibroblasts (MEFs) are resistant to apoptosis triggered by the ER stress inducer thapsigargin. In addition, E2F1 deficiency results in enhanced phosphorylation of eukaryotic translation initiation factor $2{\alpha}$ ($elF2{\alpha}$). These results therefore indicate that E2F1 deficiency increases phosphorylation of $elF2{\alpha}$ in response to ER stress triggered by thapsigargin, and suggest that the reduction in ER stress-induced apoptosis in E2F1-deficient cells is related to the high level of $elF2{\alpha}$ phosphorylation.

• The Korean Journal of Mycology
• /
• v.27 no.2 s.89
• /
• pp.175-179
• /
• 1999

In order to find less toxic antiviral agents from Basidiomycetes, EA, the water soluble substance, was prepared from the carpophores of Elfvingia applanata (Pers.) Karst. Antiviral activity of EA against vesicular stomatitis virus [New Jersey serotype, VSV(NJ)] was examined in Vero cells using plaque reduction assay in vitro. And the combined antiviral effects of EA with interferon (IFN) alpha and gamma were examined on the multiplication of VSV(NJ). EA caused a concentration-dependent reduction in the plaque formation of VSV(NJ) with 50% effective concentration $(EC_{50})$ of 2.10 mg/ml. The results of combination assay were evaluated by the combination index (CI) that was analysed by the multiple drug effect analysis. The combination of EA with IFN alpha showed more potent effect with CI values of $0.87{\sim}1.59$ for 50%, 70% and 90% effective levels than that with INF gamma with CI values of $1.05{\sim}2.03$.

• Honam Mathematical Journal
• /
• v.19 no.1
• /
• pp.47-52
• /
• 1997

• The korean journal of orthodontics
• /
• v.27 no.4 s.63
• /
• pp.539-548
• /
• 1997

The purpose of this study was to evaluate the effectiveness of gargling solution with 0.05% NaF and 10% Xylitol in orthodontic patients with fixed appliance. The sample consisted of 20 patients who were classified into an experimental group and a control group, 10 patients each. Experimental group was used experimental gargling solution and the control group was used with placebo solution. The change of S. mutans was analysed by culture on MSB and BHI agar plate pre and post 3, 6, 9 weeks. The results were as follows. 1 There were significant reduction in the number of S. mutans C.F.U. between pre and post 3 weeks(p<0.01), 9 weeks(p<0.05) in experimental group 2. There were significant reduction in the ratio of S. mutans C.F.U. to total C.F.U. between pre and post 3, 6, 9 weeks(p<0.01) in experimental group. 3. S. mutans, which were reduced until 3 weeks, did not show significant change after 3, 6, 9 weeks. 4. S. mutans were strongly suppressed until 3 weeks after gargling solution with 0.05% NaF and 10% Xylitol.

• Journal of muscle and joint health
• /
• v.5 no.1
• /
• pp.39-56
• /
• 1998

This study was an quasi-experimental study, done to identify factors Influencing the reduction of symptoms in patients with fibromyalgia. The primary purpose of the study was to develop a Self-Help Program suitable for patients with fibromyalgia in Korea. The secondary purpose was to identify the effects of a Self-Help Program which included stretching exercise. This study was carried out between Feb. 24 and July 8, 1997 and patients in the study Included out patient diagnosed with fibromyalgia based on the criteria developed by the American College of Rheumatology(1990) and H, University which is a tertiary patient care clinic for Rheumatism. The experimental group included 38 patients who were residents of Seoul or Kyungi province, and a control group of 38 patients who were residents of other areas. The control patients were matched to the experimental group patients and they were selected considering the number of tender points on the Fibromyalgia Impact Questionnaire score and a score of self-efficacy. The experimental group participated in a Self-Help Program based on the American Arthritis Foundation(1995) guidelines. The program participants participated in a small group which consisted of 12-15 members attending the program once a week, for 6 weeks with each program lasted two to two and a half hours. The stretching exercise was carried out in each patient's home every day following the video tape exercise provided by the researcher, and the researcher provided encouragement and concern to the patients by calling them once a week. The number times the exercise was performed was divided by the number of participants to calculate the percentage of performance and determine the amount of exercise. Self-efficacy was measured by the Self-Efficacy Scale developed by Lorig et al. (1989) for arthritis patients. The degree of pain was converted to scores based on the Visual Analog Scale, the number of tender points was converted to scores based on the criteria of the ACR(1990) and of Yunus. Depression was measured by CES-D and physical disability, sleep disturbance, fatigue, and anxiety of patients with fibromyalgia were measured by the Fibromyalgia Impact Questionnaire. The level of the exercise performance was converted to scores using the number of times the exercise was performed following the video tape prepared by Association of Rheumatology Health Professionals. Data were analyzed by SPSS windows and the results ire described below. 1. The experimental group which participated in the Self-Help Program showed higher efficacy scores than the control group when both groups were analyzed for depression and the number of tender points as common variables(F=9.146, p=.003). 2. The experimental group which participated in the Self-Help Program showed lower scores than the control group, for pain, the number of tender points, depression, physical disability, fatigue, sleep disturbance and anxiety. These symptoms of fibromyalgia can all be seen to have subsided(F=9.483, p=.003 : F=32.680, p=.001 ; F=11.104, p=.001, F=5.344 : p=.024, F=7.630 : P=.007, F=15.6512, p=.003 : F= 7.5412, p=.008). 3. In the experimental group, the self-efficacy score for the first three weeks showed a positive correlation with the exercise-performance score for four to six weeks (r=.387, p=.043). 4. In the experimental group, the relationship between the level of exercise-performance and the reduction of symptoms showed a significant correlation only to physical disability(r= -.500, p=.001). 5. In the experimental group, the relationship between the self-efficacy score and pain, the number of tender points, depression, physical disability, fatigue, sleep disturbance and anxiety score showed inverse correlations and thus, a reduction of symptoms occured when the self-efficacy score increased(r=-.325, p=.004 ; r= -.253, p=.027, r=-.452, p=.001 : r=-.434, p=.001 ; r=-.316, p=.005 ; r=-.460, p=.001 ; r=-.397, p=.014). Therefore, self-efficacy improved following the Self-Help Program including the stretching exercise. It was also found that physical symptoms (pain, number of tender points, level physical disability) and psychological symptoms (depression, fatigue, sleep disturbance, anxiety) were reduced. Moreover, It was found that the higher the self-efficacy, the the higher the degree of achievement of goals set for the stretching exercises. In addition, the level of exercise-performance influenced the level of physical disability, one of the symptoms of fibromyalgia. Accordingly, the conclusions from this study are that exercise-performance and the reduction of symptoms is achieved through promotion of self-efficacy. Therefore, it is proposed that are the Self-Help Program including stretching exercises is an appropriate nursing intervention for the reduction of symptoms of fibromyalgia.

• Journal of the Korean Ceramic Society
• /
• v.53 no.3
• /
• pp.338-342
• /
• 2016

ZnO thin film co-doped with F and Al was prepared on a glass substrate via simple non-alkoxide sol-gel spin coating. For a fixed F concentration, the addition of Al co-dopant was shown to reduce the resistivity mainly due to an increase in electrical carrier density compared with ZnO doped with F only, especially after the second post-heat-treatment in a reducing environment. There was no effective positive contribution to the reduction in resistivity due to the mobility enhancement by the addition of Al co-dopant. Optical transmittance of the ZnO thin film co-doped with F and Al in the visible light domain was shown to be higher than that of the ZnO thin film doped with F only.

• Journal of Nutrition and Health
• /
• v.40 no.8
• /
• pp.675-683
• /
• 2007

This study was conducted to investigate the effects of feeding different carbohydrate sources and garcinia cambogia extract(HCA) on body weight and lipid metabolism. Fifty 10-month-old male Sprague-Dawley rats weighting $635{\pm}6g$ were randomly divided into 5 groups and fed different experimental diets for 4 weeks. The carbohydrate(CHO) sources of each group were cornstarch(control group, 100% of CHO), fructose(F group and FH group, 25% of CHO) and sucrose(S group and SH group, 25% of CHO). FH group and SH group were fed diets containing 1%(W/W) of HCA. Food intake, body weight gain, and calorie efficiency were not significantly different among the groups. Perirenal fat pad weight of FH group was significantly lower than F group, but epididymal fat pad weight was not different among the groups. Fasting glucose level were not significant among the groups. Plasma lipid profile of FH or SH group was slightly lower than F or S group, respectively. The degree of difference of plasma lipid level was greater between F and FH group than those of between S and SH group. In liver, total lipid, triglyceride and total cholesterol level were slightly higher in F group than S group, and tended to be lower in FH group than F group, but tended to be higher in SH group than S group. Liver citrate lyase activity were not significant among the groups. These results suggest that HCA is potential material for reduction of body weight and improvement of plasma lipid profiles. But, there was no difference between fructose intake with HCA and sucrose intake with HCA in reduction of body weight and lipid metabolism.

• Journal of the Korean Institute of Telematics and Electronics A
• /
• v.32A no.2
• /
• pp.57-65
• /
• 1995

The effects of device geometry and layout on high speed performance such as current gain outoff frequency(f$_{T}$) and maximum oscillation frequency(f$_{max}$) are of very improtant for the scaling-down of geterojunction bipolar transistors(HBT$_{s}$). In this paper AlGaAs/GaAs HBTs are fabricated by MBE epitaxial growth and conventional mesa process, and the experimental data of emitter-base geometru dependency of HBT performance are presented in order to provide the quantitative information for optimum device structure design. It is shown that f$_{T}$ and f$_{max}$ are inversely proportional to the emiter stripe width, while the low emitter perimeter/area ratio is better to f$_{T}$ and worse ot f$_{max}$. It is also demonstrated the f$_{T}$ and f$_{max}$ are highly improved by the emitter-base spacing reduction resulting in less parsitic effects. As the result f$_{T}$ of 42GHz and f$_{max}$ of 23GHz are obtained for fabricated HBT with emitter area of 3${\times}20^{\mu}m^{2}$ and E-B spacing of 0.2$\mu$m.m.m.