• Tuberculosis and Respiratory Diseases
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• v.70 no.1
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• pp.21-27
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• 2011

Background: Although the gold standard method for research trials on epidermal growth factor receptor (EGFR) mutations has been direct sequencing, this approach has the limitations of low sensitivity and of being time-consuming. Peptide nucleic acid (PNA)-mediated polymerase chain reaction (PCR) clamping is known to be a more sensitive detection tool. The aim of this study was to compare the detection rate of $EGFR$ mutation and EGFR-tyrosine kinase inhibitor (TKI) responsiveness according to $EGFR$ mutation status using both methodologies. Methods: Clinical specimens from 112 NSCLC patients were analyzed for $EGFR$ mutations in exons 18, 19, 20, and 21. All clinical data and tumor specimens were obtained from 3 university hospitals in Korea. After genomic DNA was extracted from paraffin-embedded tissue specimens, both PNA-mediated PCR clamping and direct-sequencing were performed. The results and clinical response to $EGFR$-TKIs were compared. Results: Sequencing revealed a total of 35 (22.9%) mutations: 8 missense mutations in exon 21 and 26 deletion mutations in exon 19. PNA-mediated PCR clamping showed the presence of genomic alterations in 45 (28.3%) samples, including the 32 identified by sequencing plus 13 additional samples (6 in exon 19 and 7 in exon 21). Conclusion: PNA-mediated PCR clamping is simple and rapid, as well as a more sensitive method for screening of genomic alterations in $EGFR$ gene compared to direct sequencing. This data suggests that PNA-mediated PCR clamping should be implemented as a useful screening tool for detection of $EGFR$ mutations in clinical setting.

• Journal of Korean Society of Water and Wastewater
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• v.31 no.1
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• pp.103-114
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• 2017

A membrane bioreactor by sequentially alternating the inflow and by applying a two-stage coagulation control based on pre-coagulation was evaluated in terms of phosphorus removal efficiency and cost-savings. The MBR consisted of two identical alternative reaction tanks, followed by aerobic, anoxic and membrane tanks, where the wastewater and the internal return sludge alternatively flowed into each alternative reaction tank at every 2 hours. In the batch-operated alternative reaction tank, the initial concentration of nitrate rapidly decreased from 2.3 to 0.4 mg/L for only 20 minutes after stopping the inflow, followed by substantial release of phosphorus up to 4 mg/L under anaerobic condition. Jar test showed that the minimum alum doses to reduce the initial $PO_4$-P below 0.2 mg/L were 2 and 9 mol-Al/mol-P in the wastewater and the activated sludge from the membrane tank, respectively. It implies that a pre-coagulation in influent is more cost-efficient for phosphorus removal than the coagulation in the bioreactor. On the result of NUR test, there were little difference in terms of denitrification rate and contents of readily biodegradable COD between raw wastewater and pre-coagulated wastewater. When adding alum into the aerobic tank, alum doses above 26 mg/L as $Al_2O_3$ caused inhibitory effects on ammonia oxidation. Using the two-stage coagulation control based on pre-coagulation, the P concentration in the MBR effluent was kept below 0.2 mg/L with the alum of 2.7 mg/L as $Al_2O_3$, which was much lower than 5.1~7.4 mg/L as $Al_2O_3$ required for typical wastewater treatment plants. During the long-term operation of MBR, there was no change of the TMP increase rate before and after alum addition.

• Clean Technology
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• v.25 no.1
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• pp.63-73
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• 2019

Numerical analysis was done to evaluate the chemical reaction and the reduction rate inside of selective non-catalytic reduction to denitrification in combustion process. The $NO_X$ reduction in selective non-catalytic reduction is converted to not only nitrogen but also nitrous oxide. Simultaneous $NO_X$ reduction and nitrous oxide generation suppressing is required in selective non-catalytic reduction because nitrous oxide influences the global warming as a greenhouse gas. The current study was performed compare the computational analysis in the same temperature and amount of NaOH, and in comparison with the previous research experiments and confirmed the reliability of the computational fluid dynamics. Additionally, controlling the addition amount of NaOH to predict the $NO_X$ reduction efficiency and nitrous oxide production. Numerical analysis was done to check the mass fraction of each material in the measurement point at the end of selective non-catalytic reduction. Experimental Value and simulation value by numerical analysis showed an error of up to 18.9% was confirmed that a generally well predicted. and it was confirmed that the widened temperature range of more than 70% $NO_X$ removal rate is increased when the addition amount of NaOH. So, large and frequent changes of the reaction temperature waste incineration facilities are expected to be effective.

• Transactions of the Korean hydrogen and new energy society
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• v.27 no.1
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• pp.49-62
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• 2016

In this study, a solid oxide fuel cell (SOFC) system model including balance of plant (BOP) for building electric power generation is developed to study the effect of operating conditions on the system efficiency and power output. SOFC system modeled in this study consists of three heat-exchangers, an external reformer, burner, and two blowers. A detailed computational cell model including internal reforming reaction is developed for a planer SOFC stack which is operated at intermediate temperature (IT). The BOP models including an external reformer, heat-exchangers, a burner, blowers, pipes are developed to predict the gas temperature, pressure drops and flow rate at every component in the system. The SOFC stack model and BOP models are integrate to estimate the effect of operating parameters on the performance of the system. In this study, the design of experiment (DOE) is used to compare the effects of fuel flow rate, air flow rate, air temperature, current density, and recycle ratio of anode off gas on the system efficiency and power output.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.12
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• pp.793-799
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• 2016

In a hybrid fuel cell system, low-temperature reforming technology, which uses waste heat as a heat source, is applied to improve system efficiency. A low temperature reformer is required to optimize geometry in low thermal conditions so that the reformer can achieve the proper methane conversion rate. This study analyzed internal temperature distributions and the reaction patterns of a reformer by considering the change of the shape factor on the limited heat supply condition. Unlike the case of a high temperature reformer, analysis showed that the reaction of a low temperature reformer takes place primarily in the high temperature region of the reactor exit. In addition, it was confirmed that the efficiency can be improved by reducing the GHSV (gas hourly space velocity) or increasing the heat transfer area in the radial direction. Through reacting characteristic analysis, according to change of the aspect ratio, it was confirmed that a low temperature reformer can improve the efficiency by increasing the heat transfer in the radial direction, rather than in the longitudinal direction.

• Analytical Science and Technology
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• v.15 no.5
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• pp.410-416
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• 2002

In this study, a new quantitative analytical method has been developed for the rapid determination of vancomycin in human plasma and urine using liquid chromatography/tandem mass spectrometry (LC - MS/MS). Chromatography was carried out on a $C_{18}$ XTerra MS column ($2.1{\times}30mm$) with a particle size of $3.5{\mu}m$. The mobile phase was 0.25% formic acid in 10% acetonitrile and the flow rate was $250{\mu}L/min$. Vancomycin and caffeine (internal standard) were detected by MS/MS using multiple reaction monitoring (MRM). Vancomycin gives a predominant doubly protonated precursor molecule ($[M+2H]^{2+}$) at m/z 725.0 and a corresponding product ion of m/z 100.0. Detection of vancomycin was good, accurate and precise, with a limit of detection of 1 nM in plasma. The calibration curves for vancomycin in human plasma was linear in a concentration range of $0.01{\mu}M$ - $100{\mu}M$ for plasma. This method has been successfully applied to determine the concentration of vancomycin in human plasma and urine from pharmacokinetic study and relative studies.

• Korean Journal of Crystallography
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• v.6 no.2
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• pp.111-117
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• 1995

TiO2 thin films were prepared on a (100)silicon wafer using a chemical vapor deposition(CVD) method. The deposition experiments were performed using the TTIP in the deposition temperature ransing from 200 content. The deposition rate of TiO2 was increased with the substrate temperature and the oxygen content. The thickness of the deposited thin film and the compositional analysis of this thin films with theoxygen content were measured using Ellipsometry, SEM and ESCA, respectively. The deposited thin film was composed of a bilayer, external TiO2 and internal Ti. Carbon as a residual impurity was found to remain when zero sccm O2 was purged into a reaction chamber and the composition of the deposited thin film was found to change Ti into TiO in a deeper layer. However, when 600sccm O2 was supplied to a reaction chamber, it has been found to reside less carbon content than without O2. Finally, in the condition of 1200sccm O2, no impurity level of carbon was observed and a deeper layer consisted of the Ti composite, even though the deposited surface was composed of TiO2.

• Journal of Sensor Science and Technology
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• v.31 no.2
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• pp.102-106
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• 2022

Currently, the demand for real-time monitoring of water quality has increased dramatically. Total organic carbon (TOC) analysis is a suitable method for real-time analysis compared with conventional biochemical oxygen demand (BOD) and chemical oxygen demand (COD) methods in terms of analysis time. However, this method is expensive because of the complicated internal processes involved. The photocatalytic titanium dioxide (TiO2)-based TOC method is simpler as it omits more than three preprocessing steps. This is because it reacts only with organic carbon (OC) without extra processes. We optimized the rate between the TiO2 photocatalyst and binder solution and the TiO2 concentration. The efficiency was investigated under 365 nm UV exposure onto a TiO2 coated substrate. The optimized conditions were sufficient to apply a real-time monitoring system for water quality with a short reaction time (within 10 min). We expect that it can be applied in a wide range of water quality monitoring industries.

• Fashion & Textile Research Journal
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• v.16 no.1
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• pp.111-117
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• 2014

This study investigated the perception of upcycling for sensitive university students in regards to fashion trends. It was conducted through questionnaires delivered to male and female college students who majored in clothing related subjects from June 2012 to June 2013 in Gwangju. The contents for this research are general details, seriousness of environmental resources, awareness of upcycle, and purchasing intention for upcycling products. Most of the respondents said that recycling of resources is absolutely necessary due to the impact of environmental pollution and the consumption of resources. On the contrary, the experience of the respondents which purchased recycling products was low. The awareness of also was low, upcycling, internal upcycling brands and internal consumption groups, however, the decisions for subsequent purchases were positive. The reasons for the unsatisfactory of upcycling of products were due to quality and price. The reaction for many upcycle goods had the best question response rate in daily supplies part; subsequently, this study suggested 3 items, apparel products, fashion accessories, and daily supplies. In addition, a group which contains people who expend more for clothing had a lower awareness of upcycle and purchasing intention than other groups that contained some people who expend less. The results of the study can be used in data that recognize the necessary of upcycle education for university students, and develop educational programs. It can also encourage the purchase of upcycle products that reduce the consumption of resources.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.11
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• pp.642-648
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• 2015

Oak wood based activated carbon was modified with surface impregnation of $Fe^{3+}$ and $Al^{3+}$ metal ions mixture for enhancements of phosphate adsorption capacity in aqueous solution. The phosphate adsorption capacity of the prepared metal impregnated carbon (MC) was about 8 times higher than that of the original activated carbon (OC). Adsorption equilibrium capacities of the phosphate increased with increasing system temperature. The adsorption equilibrium isotherm of phosphate on the prepared MC could be represented by the Langmuir equation. Thermodynamic parameters also indicated that adsorption system was spontaneous and endothermic reaction. The internal diffusion coefficient was measured to analyze the adsorption behavior and kinetic rate. To determine the internal diffusion coefficient, pore diffusion model (PDM) was employed and the result was in good agreement with experimental data.