• Journal of the Korean Society for Precision Engineering
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• v.23 no.1 s.178
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• pp.145-151
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• 2006

Wheel bearing unit has been exclusively applied to car wheel supporting device. The seal for wheel bearing is required to have both high sealing effects and low reaction forces because wheel bearing are operated on adverse environmental conditions such as mud and splash water. High sealing effects are for the protection of bearing ball wear from dust influx. In order to ensure high sealing effects, it is a easiest way to increase contact force which are affected by geometric characteristics, material properties and interferences between seal and inner bearing but induces higher wear phenomena. Interferences in all variables are most important factor to determine the performance of wheel bearing. In this study, optimization of interference amount was performed with finite element analysis with commercial code ABAQUS. For the sake of finite element analysis, tensile tests of rubber material were conducted and governing equation of nonlinear behavior was achieved. Hock-up bearing was manufactured with optimized interference amount. Results of torque and mud spray tests using this bearing unit are performed. Less torque and moisture influx of bearing with optimized interference amount is evidence to validity of this study.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.5
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• pp.430-435
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• 2006

Purpose : The aim of this study was to investigate healed bovine bone particles ($Bio-Oss^{(R)}$) and absorbable collagen sponge ($CollaPlug^{(R)}$) applied extraction socket site at 4-6 months' post-extraction. Material and methods : From August, 2004 to October, 2005, 17 sockets in 5 adult patients were selected out of the patients whose received ridge preservation using bovine bone particles and absorbable collagen sponges at Dept. of oral and maxillofacial surgery in Samsung Medical Center. There were 5 male patients, ages 30 to 58 years. Immediate postoperation and 4-6 months after operation study models were compared to evaluate the ridge dimension by measuring vertical height and horizontal width of alveolar ridge. Results : The measurements at 4-6 months revealed, in the ridge dimension, a loss of vertical height of 0.91${\pm}$0.40mm and horizontal width of 1.25${\pm}$0.58mm. There was no adverse reaction. Conclusion : This study suggests that treatment of extraction sockets with graft materials and collagen sponges is valuable in preserving alveolar bone in extraction sockets and preventing alveolar ridges defects.

• Journal of Microbiology and Biotechnology
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• v.27 no.1
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• pp.84-91
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• 2017

The concern over the use of melittin in honey bee venom due to its adverse reaction caused by allergens such as phospholipase A2 ($PLA_2$) and hyaluronidase (HYA) has been an obstacle towards its usage. We developed a novel single-step method for melittin purification and the removal of $PLA_2$ and HYA. This study explores the influence of pH, buffer compositions, salt concentration, and types of cation-exchange chromatography resins on the recovery of melittin and the removal of both HYA and $PLA_2$. Melittin was readily purified with a strong cation-exchange resin at pH 6.0 with sodium phosphate buffer. It resulted in a recovery yield of melittin up to 93% (5.87 mg from a total of 6.32 mg of initial melittin in crude bee venom), which is higher than any previously reported studies on melittin purification. $PLA_2$ (99%) and HYA (96%) were also successfully removed. Our study generates a single-step purification method for melittin with a high removal rate of $PLA_2$ and HYA, enabling melittin to be fully utilized for its therapeutic purposes.

• Journal of Pharmaceutical Investigation
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• v.9 no.3
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• pp.1-8
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• 1979

The main route of metabolism of isonicotinic acid hydrazid (INH) in man is its conjugation with acetyl coenzyme A to form acetyl-INH. The reaction is catalyzed by an N-acetyl transferase in the liver. The acetylated drug can be excreted by the kidney more efficiently than INH, and the biological half-life of the drug in the body depends upon how rapidly the drug can be acetylated. This report measured the concentration of INH in the blood of 147 individuals 6 hours after they received a standard dose (9.8mg/kg) and plotted the data as a frequeney distribution hiotogram. There was bimodality, with a mean for one subpopulation at approximately $0.6{\sim}0.8\;mcg/ml.$, and a mean for the other subpopulation between 2.8 and 4.0mcg/ml. As might be expected slow acetylators of INH are more likely to develop a cumulative toxicity to the drug. The principle ,toxicity to INH is a peripheral neuritis but this adverse effect can be prevented by given extra pyridoxin to the patients, and the vitamin does not alter the antitubercular activity of INH. This report carried out that pyridoxine does not alter the ratio of free INH to the total INH in blood.

• Environmental Engineering Research
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• v.18 no.3
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• pp.163-168
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• 2013

In this study, an innovative media, iron mixed ceramic pellet (IMCP) has been developed for arsenic (As) removal from groundwater. A porous, solid-phase IMCP (2-3 mm) was manufactured by combining clay soil, rice bran, and Fe(0) powder at $600^{\circ}C$. Both the As(III) and As(V) adsorption characteristics of IMCP were studied in several batch experiments. Structural analysis of the IMCP was conducted using X-ray absorption fine structure (XAFS) analysis to understand the mechanism of As removal. The adsorption of As was found to be dependent on pH, and exhibited strong adsorption of both As(III) and As(V) at pH 5-7. The adsorption process was described to follow a pseudo-second-order reaction, and the adsorption rate of As(V) was greater than that of As(III). The adsorption data were fit well with both Freundlich and Langmuir isotherm models. The maximum adsorption capacities of As(III) and As(V) from the Langmuir isotherm were found to be 4.0 and 4.5 mg/g, respectively. Phosphorus in the water had an adverse effect on both As(III) and As(V) adsorption. Scanning electron microscopy results revealed that iron(III) oxides/hydroxides are aggregated on the surface of IMCP. XAFS analysis showed a partial oxidation of As(III) and adsorption of As(V) onto the iron oxide in the IMCP.

• Journal of Korean Society for Atmospheric Environment
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• v.24 no.3
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• pp.329-335
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• 2008

Volatile organic compounds emitted to the atmosphere can cause adverse effects on human health and participate in photochemical smog formation reactions. The destruction of a series of VOCs has been carried out by non-thermal plasma in other researches. And the characteristic of non-thermal plasma was operated at atmospheric pressure and low temperature. A new type non-thermal plasma reactor was investigated combined Glidarc plasma with water jet in this research. Also, it was found that the water-jet had an significant effect on the toluene removal efficiency. But too much water content does not favor toluene decomposition by decreasing of reaction temperature. The input toluene concentration, gas flow rate, water flow rate and specific energy input were used as experiment variables. The toluene removal efficiency, energy efficiency and specific energy input were 75.3%, 146.6 g/kWh and $1.12kWh/m^3$ at a water flow rate of 100 mL/min.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.3
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• pp.505-510
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• 2000

In this study the effects of pre-chlorination on the coagulation of water which contain Microcystis aeruginosa. were investigated on the laboratory scale. We prepared the sample of $10^5cell/mL$ Microcystis aeruginosa and then applied 0.2, 1.0, 10 mg-Cl/L chlorine on the sample After reaction period(1 minute and 1 hour), each sample was coagulated. As a result, after 0.4 mg-Al/L coagulant dose, turbidities of all samples were below 2 mg-Kaolin/L. Turbidity was not affected by chlorine dose. As the dose of chlorine was increased, the residual aluminum was decreased, but result of $UV_{254}$ was adverse.

• Korean Journal of Veterinary Research
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• v.35 no.4
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• pp.753-758
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• 1995

The study was carried out to investigate the pathogenicity of EHV isolate to hamsters and mice and immunogenicity of experimentally produced. vaccine were evaluated in the horses. Hamsters infected. intranasally with $LC_1$ isolate showed symptoms of nasal discharge, conjunctivitis and body weight loss during the observation period of 12 days after infection, while only slight depression and body weight loss were noticed with mice infected with $LC_1$ indicating that hamsters are more susceptible to the virus. Antibody titer of mice and hamsters were gradually increased to highest level of 1:2560~10240, 1:640~1280, respectively, at 7~12 days post vaccination. Horses immunized against $LC_1$ killed vaccine reached to maximum antibody titer of 1:20480 around 4 weeks after 1st vaccination and declined after 12 weeks post vaccination. No significant antibody increase were detected after 2nd vaccination. Mean body temperature and mean total leukocyte counts remained within normal range and no adverse reaction were noticed after vaccination.

• Korean Journal of Clinical Pharmacy
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• v.5 no.2
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• pp.33-49
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• 1995

The purpose of this study is to understand present situation of clinical trials, and evaluate the preparedness of the desiRnated institutions to abide by GCP(Good Clinical Practice) standards during clinical trials. Survey on the status of clinical trials was conducted for the desienated 83 clinical trial hospitals, and response rate was $95.2\%$. The results showed that 39 hospitals have conducted clinical trials to obtain drug manufacturing approval from 1990 to 1994. Most of them were trials on Phase III. Only $46.8\%$ of the institutions had sufficient human resources to perform the clinical trials. Institutions which established IRB(Institutional Review Board) accounted for 41 or $51.9\%$, but those who have a protocol evaluation guideline, or Adverse Drug Reaction(ADR) reporting system were only 12, and 21 Places, respectively. Regarding supervision of the investigational drugs, less than 30 institutions designated pharmacist as a supervisor. In conducting clinical trials, $97.4\%$ of trials had high rates of prior consent of testees, but only part of them-$61.7\%$-gave written consent. The level of conducting GCP is found to be unsatisfactory. Institutions must build the appropriate infrastructure and government must prepare in order to protect testees' rights as well as to ensure validity of the results.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.21 no.6
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• pp.747-757
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• 1997

A numerical investigation of the fuel concentration field in a fluidized bed has been carried out for the scale-up of a fluidized bed combustor (FBC). A two-dimensional transient model is developed using the two-phase fluidization, a simple chemical reaction, and lateral solid mixing theories. The uniformity of fuel concentration distributions is controlled by the location and the number of fuel feeders, fluidizing velocities and the bed-heights. While larger bubbles owing to greater fluidizing velocities enhance the fuel-dispersion in the bed, they have adverse effects on fuel combustion and thus result in the increase of fuel concentration, since a greater bubble means a larger bypass which reduces gas-exchange rates between bubble and emulsion phases. Average or maximum values of the bed fuel concentration are utilized as criteria for the scale-up from a pilot/lab-scale to a commercial-size bed.