• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07a
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• pp.232-235
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• 2002

An 150 kV gas cluster ion accelerator was fabricated and assessed. The change of surface morphology and surface roughness were examined by an atom force microscope (AFM) after irradiation of $CO_2$ gas clusters on Si (100) surfaces at the acceleration voltages of 50 kV. The density of hillocks induced by cluster ion impact was gradually increased with the dosage up to 5$\times$10$^{11}$ ions/$\textrm{cm}^2$. At the boundary of the ion dosage of 10$^{12}$ ions/$\textrm{cm}^2$, the density of the induced hillocks was decreased and RMS (root mean square) surface roughness was not deteriorated further. At the dosage of 5x10$^{13}$ ions/$\textrm{cm}^2$, the induced hillocks completely disappeared and the surface became very flat. In addition, the irradiated region was sputtered. $CO_2$ cluster ions are irradiated at the acceleration voltage of 25 kV to remove hillocks on indium tin oxide (ITO) surface and thus to attain highly smooth surfaces. $CO_2$ monomer ions are also bombarded on the ITO surface at the same acceleration voltage to compare sputtering phenomena. From the AFM results, the irradiation of monomer ions make the hillocks sharper and the surfaces rougher On the other hand, the irradiation of $CO_2$ cluster ions reduces the hight of hillocks and planarize the ITO surfaces. From the experiment of isolated cluster ion impact on the Si surfaces, the induced hillocks m high had the surfaces embossed at the lower ion dosages. The surface roughness was slightly increased with the hillock density and the ion dosage. At higher than a critical ion dosage, the induced hillocks were sputtered and the sputtered particles migrated in order to fill valleys among the hillocks. After prolonged irradiation of cluster ions, the irradiated region was very flat and etched.

• Journal of Korean Society of Water and Wastewater
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• v.10 no.4
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• pp.55-63
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• 1996

This research was based on comparing ozonation with combined ozone/ultraviolet oxidation through the methods of reducing THM produced during water treatment. The results were as follows ; 1. The decline of THM concentration was appeared according as ozone dosage increases with ozonation and combined ozone/ultraviolet oxidation. The more effective method was the treatment of irradiating UV then ozonation. In the beginning of reaction the decline rate of THM formation potential was low, I thought it was because that the reaction of ozone and humic acid needed times to be steady state, or that THM formation potential existed according to humic acid. 2. The effect of combined ozone/ultraviolet oxidation when ozone dosage was 4.2mg/L min was almost the same that of ozonation when ozone dosage was 8.6mg/L min. 3. In experiment of TOC decline through ozonation and combined ozone/ultraviolet oxidation, TOC concentration was also dropped according to increasing ozone dosage and the more effective results were showed in treatment of irradiating UV than ozonation. But the similar TOC remove rates were showed in experiment of changing with ozone dosage during combined ozone/ultraviolet oxidation TOC remove rates were low in proportion to the remove rates of THM formation potential, it was considered that humic acid was made low molecule itself though ozonation and ozone/ultraviolet oxidation. Moreover, the high degree of remove efficiency will be get though the treatment of activated carbon of GAC treatment after combined ozone/ultravilet oxidation.

• Journal of the Korean Society of Radiology
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• v.10 no.7
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• pp.539-543
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• 2016

In this research, The way to decrease a patient's exposure dose by reducing the scattered radiation dosage outside a radiation field with an diagnosis X-ray was examined. The scattered radiation dosage reaching other parts outside the radiation field was to be reduced by attaching a self-produced $150{\times}190mm^2$ lead plate to the lower part of a collimator. When a lead plate was inserted additionally and the scattered radiation dosage of the X axis was measured in the direction of the central X-ray axis, It was found out to have been decreased by 26 to 36%, and in the direction of Y axis, which was vertical direction from the central axis, The scattered radiation dosage depending on whether a lead plate was used or not displayed no large differences. These results shows that the impact of the scattered radiation by the off focus X-ray that was generated around the focus was bigger than that generated by the shutter of the collimator. Therefore it has been concluded that installing an additional lead plate in the lower part of the existing collimator can decrease the scattered radiation dosage outside a radiation field.

• Korean Journal of Animal Reproduction
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• v.4 no.1
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• pp.28-34
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• 1980

This experiment was carried out to study effects fo dosage and insemination interval on fertility and hatchability of whole semen and diluted semen with yolk skim milk and skim milk dilutors. The results obtained are as follows: 1. Whole semen showed higher fertility than diluted semen with yolk skim milk and skim milk dilutors. In case of diluted semen, the fertility was higher in 0.04$m\ell$ dosage than 0.02$m\ell$ and in skim milk than yolk skim milk dilutor. 2. The average fertility in inseminational intervals of 6, 5, 4 and 3 days was 52.4, 35.5, 48.7 and 44.2% in whole semen and 40.6, 17.2, 13.9 and 20.5% in 0.04$m\ell$ diluted semen with yolk skim milk dilutor. The fertility was not improved by shortening of insemination interval. 3. There was no considerable difference in hatchability of fertilized egg among the dosage of 0.02$m\ell$ of whole semen, 0.02$m\ell$ and 0.04$m\ell$ of diluted semen with yolk skim milk, and among the insemination intervals of 6, 5, 4 and 3 days. 4. Some differences in fertility among the passed days after insemination were decreased in the whole semen by shortening insemination interval from 6 and 5 days to 4 and 3days and also decreased in the diluted semen by shortening it to 3 days and by increasing dosage from 0.02$m\ell$ to 0.04$m\ell$. 5. Hatchability of fertilized egg showed no difference among the passed days during 6 days insemination interval both in the whole semen and the diluted semen. 6. The whole semen and the diluted semen with skim milk had not considerable difference in fertility among the passed days during 3 and 4 days insemination intervals, but the diluted semen with yolk skim milk had. 7. Hatchability of fertilized egg from the whole semen diluted semen with yolk skim milk and skim milk dilutors showed no difference among the passed days during 3 and 4 days insemination intervals.

• Korean Journal of Veterinary Research
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• v.39 no.6
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• pp.1161-1167
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• 1999

To investigate the effect of diazepam on fetal development in pregnant rats, this experiment was performed in eighty Sprague-Dawley female rats which were 8 weeks old and grouped into two according to different diazepam treatment period during 5-9 days of gestation and 10-14 days of gestation. Both experimental groups were included by saline treated groups (control) and diazepam-treated groups (6mg, 12mg and 24mg), respectively. Diazepam was injected to pregnant rats subcutaneously, which were sacrified on 20 days of gestation and mean litter size, fetal body weight, fetal crown-rump length (CRL) and pathological findings were examined. 1. Concerning mean litter size, diazepam-treated groups showed lower mean litter size than control in both 5-9 days and 10-14 days of gestation groups(p < 0.05) without difference according to dosage of diazepam and day of gestation. 2. Concerning fetal body weight, diazepam-treated groups during 5-9 days of gestation showed lower fetal body weight than control and the other treated group during 10-14 days(p < 0.01) without difference according to dosage of diazepam. Diazepam-treated group during 10-14 days of gestation showed no difference among experimented groups. 3. Concerning fetal crown-rump length (CRL), diazepam-treated groups during 5-9 days of gestation showed shorter CRL than control and the other treated group during 10-14 days of gestation(p < 0.01) without difference according to dosage of diazepam. 4. Reduction of mean litter size, fetal body weight and CRL was shown from when treated by the dosage of 6mg/kg of diazepam. 5. Maternal mortality according to dosage of the 20mg/kg of diazepam were 30% and 20% in the treated group during 5-9 days and 10-14 days of gestation, respectively. These results indicated that diazepam treatment in pregnant rats caused considerable reduction of mean litter size, fetal body weight and fetal crown-rump length when treated during 5-9 days of gestation.

• Journal of Pharmaceutical Investigation
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• v.34 no.3
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• pp.229-254
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• 2004

The objective of this study was to scrutinize the rationale of SUPAC-MR and its application in processing postapproval changes to modified release solid oral dosage forms. The types of postapproval changes that were primarily covered with SUPAC-MR included variations in the components and composition, the site of manufacturing, batch size, manufacturing equipment, and manufacturing process. SUPAC-MR defined levels of postapproval changes that the industry might make. Classification of such categories was based on the likelihood of risk occurrence and potential impact of changes upon the safety and efficacy of approved drug products. In most cases, the changes could be classified into 3 levels. It described what chemistry, manufacturing, and control tests should be conducted for each change level. The important tests specified in SUPAC-MR were batch release, stability, in vitro dissolution, and in vivo bioequivalence tests. It then suggested what type of a filing report should be submitted to the FDA for each change level. In general, level 1 changes could be reported in an annual report, whereas level 2 and/or 3 changes could be submitted in changes-being-effected or prior approval supplements. It could be understood that the purpose of SUPAC-MR was to maintain the safety and quality of approved modified release solid oral dosage forms undergoing certain changes. At the same time, it contributed to providing a less burdensome regulatory process with the manufacturers when they wanted to make postapproval changes. European regulatory agencies also implemented SUPAC-like regulations in handling such changes to drug products. Therefore, in this study a recommendation was made for KFDA and the Korean industry to evaluate thoroughly the usefulness of these guidances and regulations in dealing with postapproval changes to modified release solid oral dosage forms.

• Journal of Environmental Science International
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• v.19 no.7
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• pp.889-900
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• 2010

The experimental design and response surface methodology (RSM) have been applied to the investigation of the electro-UV complex process for the disinfection of E. coli in the water. The disinfection reactions of electro-UV process were mathematically described as a function of parameters power ($X_1$), NaCl dosage ($X_2$), initial pH ($X_3$) and disinfection time ($X_4$) being modeled by use of the Box-Behnken technique. The application of RSM using the Box-Behnken technique yielded the following regression equation, which is an empirical relationship between the residual E. coli number and test variables in actual variables: Ln (CFU) = 23.57 - 0.87 power - 1.87 NaCl dosage - 2.13 pH - 2.84 time - 0.09 power time - 0.07 NaCl dosage pH + 0.14 pH time + 0.03 $power^2$ + 0.47 NaCl $dosage^2$ + 0.20 $pH^2$+ 0.33 $time^2$. The model predictions agreed well with the experimentally observed result ($R^2$ = 0.9987). Graphical response surface and contour plots were used to locate the optimum point. The estimated ridge of maximum response and optimal conditions for the E. coli disinfection using canonical analysis was Ln 1.06 CFU (power, 15.40 W; NaCl dosage, 1.95 g/L, pH, 5.94 and time, 4.67 min). To confirm this optimum condition, the obtained number of the residual E. coli after three additional experiments were Ln 1.05, 1.10 and Ln 1.12. These values were within range of 0.62 (95% PI low)~1.50 (95% PI high), which indicated that conforming the reproducibility of the model.

• Korean Journal of Clinical Pharmacy
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• v.12 no.1
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• pp.7-12
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• 2002

Pharmacokinetic parameters and dosage of aminoglycosides (AGs) were studied retrospectively in 36 patients with neutropenic fever after stem cell transplantation in Seoul National University Hospital from July 1996 to June 2001. AGs pharmacokinetic parameters were calculated with steady-state peak and trough serum drug concentrations by the method of Sawchuk and Zaske et at. The calculated aminoglycosides volume of distribution and clearance were greater than population value $(0.36\pm0.06\;L/kg,\;116\pm32\;ml/min/1.73\;m^2,\;respectively)$. The average dosage of aminoglycosides required to maintain optimal serum AGs concentration was also greater than recommended dose in insert paper. The average dosage of amikacin was $11\pm2.1$ mg/kg every 12 hours (In case of tobramycin, $2.09\pm0.37$ mg/kg every 8 hours or $2.59\pm0.20$ mg/kg every 12 hours). The relationship between AGs volume of distribution and sex, serum albumin (g/dl), body mass index $(kg/m^2)$, body weight change $(\%)$, the amount of fluid inpu (ml/kg/day), the degree of hematocrit decrease $(\%)$ were studied respectively. Univariate anlysis revealed that body mass index $(kg/m^2)$, the amount of fluid input (ml/kg/day) and the degree of hematocrit decrease $(\%)$ had significant correlation with aminoglycosides volume of distribution. But sex, serum albumin, body weight change $(\%)$ had no significant correlation with aminoglycosides volume of distribution.

• Resources Recycling
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• v.25 no.3
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• pp.20-28
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• 2016

Assessment on adequate dosage of superplasticizer in eco-friendly ultra-high performance concrete (UHPC) containing industrial by-products was carried out from the standpoint of workability. Various types of industrial by-products, including blast-furnace slag, coal bottom ash and rapid-cooled electric arc furnace oxidizing slag, were utilized, and the effects of dosage of superplasticizer on the workability and strength of UHPC containing the by-products were evaluated. By utilizing the by-products, the workability of UHPC was improved and required dosage of superplasticizer was reduced. In addition, the material cost for UHPC with by-products was decreased due to reduced dosage of superplasticizer.

• Journal of Pharmacopuncture
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• v.14 no.1
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• pp.5-24
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• 2011

Objective: This study was performed to analyse four weeks repeated -dose toxicity of Sweet Bee Venom (SBV-pure melittin, the major component of honey bee venom) in rats. Methods: All experiments were conducted under the regulations of Good Laboratory Practice (GLP) at Biotoxtech Company, a non-clinical study authorized institution. Male and female rats of 5 weeks old were chosen for the pilot study of four weeks repeated-dose toxicity and was injected at the level of 0.56 mg/kg body weight (eighty times higher than the clinical application dosage as the high dosage), followed by 0.28 and 0.14 mg/kg as midium and low dosage, respectively. Equal amount of normal saline was injected as the control group every day for four weeks. Results: 1. No mortality was witnessed in all of the experiment groups. 2. All experiment groups appealed pain sense in the treating time compared to the control group, and side effects such as hyperemia and movement disorder were observed around the area of injection in all experiment groups, and the higher dosage in treatment, the higher occurrence in side effects. 3. Concerning weight measurement, neither male nor female groups showed significant changes compared to the control group. 4. Concerning to the CBC and biochemistry, all experiment groups didn't show any significant changes compared to the control group. 5. Concerning weight measurement of organs, experiment groups didn't show any significant changes compared to the control group. 6. To verify abnormalities of organs and tissues, those such as cerebellum, cerebrum, liver, lung, kidney, and spinal cords were removed and we conducted histologocal observation with H-E staining. Concerning the histologocal observation of liver tissues, some fatty changes were observed around portal vein in 0.56 mg/kg experiment group. But another organs were not detected in any abnormalities. 7. The proper high dosage of SBV for the thirteen weeks repeated test in rats may be 0.28 mg/kg in one time. Conclusion: Above findings suggest that SBV is relatively safe treatment medium. Further studies on the subject should be conducted to yield more concrete evidences.