• Corrosion Science and Technology
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• v.9 no.5
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• pp.209-215
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• 2010

To elucidate the effect of aging time on resistance to localized corrosion of hyper duplex stainless steel, a double-loop electrochemical potentiokinetic reactivation test a potentiodynamic anodic polarization test, a scanning electron microscope-energy dispersive spectroscope analysis, and a thermodynamic calculation were conducted. With an increase in aging time, sigma phases are precipitated much more than chi phases due to the meta-stable chi phase acting as a transition phase. As aging time at $850^{\circ}C$ increases, the corrosion resistance decreases owing to an increase in Cr, Mo and W depleted areas adjacent to the intermetallic phases such as sigma phases and chi phases.

• JSTS:Journal of Semiconductor Technology and Science
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• v.4 no.2
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• pp.124-127
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• 2004

W/n-GaN Schottky diodes were irradiated with $^{60}Co\;{\gamma}-rays$ to doses up to 315Mrad. The barrier height obtained from current-voltage (I-V) measurements showed minimal change from its estimated initial value of ${\sim}0.4eV$ over this dose range, though both forward and reverse I-V characteristics show evidence of defect center introduction at doses as low as 150 Mrad. Post irradiation annealing at $500^{\circ}C$ increased the reverse leakage current, suggesting migration and complexing of defects. The W/GaN interface is stable to high dose of ${\gamma}-rays$, but Au/Ti overlayers employed for reducing contact sheet resistance suffer from adhesion problems at the highest doses.

• Fire Science and Engineering
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• v.34 no.2
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• pp.22-29
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• 2020

In this study, the fire patterns, heat emissions, and smoke generated by means of fire tests developed for representative combustibles in residential facilities were analyzed from among seven fire types. These combustibles were selected in a previous study to simulate real-world situations and professionalism required while dealing with these types of fires and develop the field commander training content. Consequently, the maximum heat dissipation was recorded as 728.6 kW, followed by the dissipation measured from the combination of a mattress and electric blanket, desk and chair, and TV and mattress. The total heat emission of sofas (226.2 MJ) and the combination of mattress and electric blanket (2,259.5 ㎡) was recorded. In this study, the scope of the tests was limited to the fire characteristics and characteristics of the combustibles, and it is expected that a simulation using various data acquisition methods and FDS would be performed and evaluated at a later stage.

• Analytical Science and Technology
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• v.11 no.4
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• pp.243-247
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• 1998

Cisplatin is a platinum-containing antitumor agent with nephrotoxic and neurotoxic side effects. An analytical method for measuring cisplatin in plasma by FAAS was developed, which is rapid, simple and need no sample preparation. The linearity test of calibration curve in the range of 20~1000 ng/mL showed good correlation coefficient of r=0.999. The result of accuracy test appeared to be relative standard deviation of < 5.0% at concentration range from 50 to 1000 ng/mL. When $200{\mu}L$ of plasma was used, detection limit was 10 ng/mL. Therefore, it can be applied for the monitoring in plasma for optimal condition of treatment and reduce of toxicity.

• Journal of Pharmaceutical Investigation
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• v.19 no.2
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• pp.93-98
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• 1989

The study was performed to compare the dissolution, diffusion and absorption characteristics using Sartorius dissolution and absorption simulator and in vivo bioavailability of commercially available rifampicin capsules. Both brands C and F showed similar dissolution patterns and absorption properties through artificial gastric barrier in Sartorius simulator. Diffusion rate constants through the membrane of brands C and F were $3.04\;{\times}40^{-3}$ and $2.88\;{\times}\;10^{-3}cm/min$, respectively. Rifampicin capsules were administered orally to six fasted healthy volunteers according to cross-over design. The pharmacokinetic parameters between brands C and F, maximum plasma drug concentration$(C_{max})$, the time to reach $C_{max}$, absorption rate constant and area under the curve $(AUC_{0-24hr})$, elimination rate constant, and amount of drug excreted in urine were 6.11 and $7.27\;{\mu}g/ml$, 2.71 and 1.52 hr, 0.6371 and $1.6456 hr^{-1}$, 57.84 and $57.28\;{\mu}g\;{\cdot}\;hr/ml$, 0.1891 and $0.1734 hr^{-l}$, 119.98 and 119.93 mg, respectively. On the basis of experimental results, it was concluded that the bioavailability of brand C rifampicin capsules was almost the same as that of brand F rifampicin capsules.

• Journal of Environmental Health Sciences
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• v.40 no.3
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• pp.187-203
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• 2014

Objectives: As the demand to deal with pathogens in domestic research institutions has expanded and biological accidents have increased, the need for systematic biosafety management in infectious disease laboratories has grown. According to international standards, risk assessment (RA) is required for biosafety management. However, RA criteria have not been clearly established in Korea, so to this end I have attempted to determine RA criteria meeting international levels Methods: In order to provide RA criteria for application, I analyzed the RA criteria in use in the U.S., Europe and at international organizations. In order to ensure the public nature of the RA criteria, I constructed the research model through modified management consulting methodology reflecting the model of Radnor and O'Mahoney. Results: According to the results of the study, existing laboratory biosafety regulations were comparable to domestic laboratory safety laws. Existing laboratory biosafety standards that are designed around risk factors were found to be insufficient. An RA case to be carried out in infectious disease laboratories at the National Institute of Health of KCDC was identified. Conclusion: To establish a systematic risk management system meeting international standards, it was necessary first to harmonize the systems of national and international standards. In addition, in order to provide specific biosafety management on-site, I recognized a need for methodology and planning strategies to discover biosafety management so that it can be carried out as required through the RA of individual laboratories.

• BMB Reports
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• v.30 no.3
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• pp.234-236
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• 1997

Chronic hepatitis C virus (HCV) infection is associated with the rapid development of cirrhosis and hepatocellular carcinoma. It has been reported that the amount of HCV RNA may be correlated with the progression of hepatitis and may be a prognostic marker for treatment of HCV patients. The direct detection of HCV RNA by reverse transcription-polymerase chain reaction (RT-PCR) is widely used to determine the presence of circulating virions. The most relevant limit of this approach is the lack of quantitative information about the viral titer. In the present study, we developed the method for HCV quantitation using competitive reverse transcription (CRT)-PCR using the deleted HCV standard. The serially diluted standard was added in titrated amounts to the target HCV RNA. The mixture was then reverse transcribed and amplified in the same reaction tube. The methods were evaluated using over 110 HCV-PCR positive samples in Koreans. About 59% of the samples were judged to contain $10^{5}-10^{6}$ copies of HCV RNA in 1 ml of serum.

• Journal of the Korean Institute of Telematics and Electronics D
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• v.34D no.4
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• pp.106-112
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• 1997

We demonstrate a novel wavelength -division add/drop multiplexer employing fiber bragg gratings and polarization beam splitters. the multiplexer is easy to fbricate without any special technique such as UV trimming, and yet shows very stable performance with less than 0.3-dB crosstalk power penalty in a 0.8-nm-spaced, 2.5Gbps-per-channel WDM transmission system. We find that the rejection of adjacent channels is more than -6dB, and the signal leakage through output port is less than -34dB.

• Nuclear Engineering and Technology
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• v.52 no.11
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• pp.2607-2612
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• 2020

The present work was aimed to show the possibility of using hydrogel (acrylic/boric acid) for evaluation of the neutron radiation shielding. The influence of acrylic acid concentration, different gamma doses and relative contents of boric acid were studied. The physical properties and the thermomechanical stability of the studied samples were investigated. The shielding property of the composite for neutron was tested by Pu-Be neutron source (5 Ci) under room temperature. The neutron fluence rates and gamma fluxes were measured using a stilbene organic scintillator. The macroscopic effective removal cross-section Σ_R (cm^-1) of fast neutrons and total attenuation coefficient μ (cm^-1) of gamma rays has been studied experimentally. The transmission parameters, the relaxation length (??) and the half-value layer (HVL) were obtained. The obtained results indicated that the addition of boric acid to acrylic acid tends to increase the macroscopic effective removal cross-section Σ_R (cm^-1) to 0.141 compared to 0.094 of ordinary concrete.

• Journal of Surface Science and Engineering
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• v.47 no.2
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• pp.57-62
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• 2014

The biogas holder is composed of an outer membrane and an inner membrane which are subject to outdoor exposure and gas exposure respectively. The influence of weathering conditions on the photo-degradation of a biogas holder was investigated. Tests were performed under three different methods - outdoor exposure tests (Seosan, Arizona), accelerated tests (Xenon-are lamp) with the outer-membrane of biogas. Moreover, the changes in the aging process were monitored using color difference, gloss, the contact angle and an optical microscope. Changes in physical properties, such as decrease reduction in gloss, decrease in the contact angle, increase in color difference were observed in the aging process. The comparison between membrane 3B, 4B and membrane 5B under xenon-arc were discussed. Membrane 5B was very sensitive to ultraviolet (UV) ray. There were many difficulties in the outdoor exposure test due to acid rain, dust, and stain resistance.