• Proceedings of the KSME Conference
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• 2003.11a
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• pp.222-227
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• 2003

Recent advances in room-temperature, visible and near-IR diode laser sources for telecommunication, optical data storage applications are enabling combustion diagnostics system based on diode laser absorption spectroscopy. In contrast to some traditional sampling-based gas-sensing instruments, tunable diode laser absorption spectroscopy system is advantageous because of their non-invasive nature, high sensitivity, fast response time and real-time measurement capability. So, combined with fiber-optics and high sensitive detection strategies, compact and portable sensor system arc now appearing for a variety of applications. The objective of this research is to take advantage of distributed feed-back diode laser and measure the $CO_{2}$ concentration (by using direct absorption and wavelength modulation spectroscopy methods). In addition to survey spectra of $CO_{2}$ bands and spectroscopic parameters between 1565 and 1579 run were computed at temperatures between 296 and 1200 K (by using HITRAN 2000 database). It experimentally found out that the features of direct absorption and wavelength modulation spectroscopy methods.

• ETRI Journal
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• v.32 no.3
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• pp.440-446
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• 2010

Array-based gas sensors now offer the potential of a robust analytical approach to odor measurement for medical use. We are developing a fast reliable method for detection of microbial infection by monitoring the headspace from the infected wound. In this paper, we present initial results obtained from wound-state monitoring for burn patients using an electronic nose incorporating an automated solid-phase microextraction (SPME) desorption system to enable the system to be used for clinical validation. SPME preconcentration is used for sampling of the headspace air and the response of the sensor module to variable concentrations of volatiles emitted from SPME fiber is evaluated. Gas chromatography-mass spectrometry studies prove that living bacteria, the typical infectious agents in clinical practice, can be distinguished from each other by means of a limited set of key volatile products. Principal component analysis results give the first indication that infected patients may be distinguished from uninfected patients. Microbial laboratory analysis using clinical samples verifies the performance of the system.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.12
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• pp.1281-1286
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• 2008

Nitrous oxide(N$_2$O) is well known as a greenhouse gas that contributes to the global warming (310 times more per molecule than carbon dioxide) and to the destruction of the ozone layer. The objective of this study is to estimate N$_2$O emission factor using an emission isolation flux chamber from municipal wastewater treatment plants. N$_2$O gas was analysed by GC/ECD with 6 port gas sampling valve. The results of this study were as follows. N$_2$O emission factor of 5-Stage process from Y wastewater treatment plants was lowest as 0.94 g-N$_2$O/kg-TN. And that of other processes were 2.65 g-N$_2$O/kg-TN for Activated sludge process, 9.30 g-N$_2$O/kg-TN for Denipho process, and 26.73 g-N$_2$O/kg-TN for Sequencing Batch Reactor process. We have known that 5-Stage process is most appropriate process to reduce greenhouse for municipal wastewater treatment plants.

• Journal of the Korean Institute of Gas
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• v.19 no.1
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• pp.12-17
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• 2015

The core of the CNG fueling station is the compressor and most of CNG compressors in Korea require lubrication. Lubrication oil of CNG compressor that can be transferred into the pressure regulators and the engines of fueling system can cause a negative effect on NGV(Nature Gas Vehicle) performance during refueling due to oil Carry-over. In order to avoid the problem, it is necessary to enhance the quality of the compressed natural gas by measuring quantitatively the amount of the transferred oil. In this research, a sampling device and sampling tube were developed, which can be used with a gravimetric method of detection to measure CNG oil Carry-over. In addition, CNG samples were taken at 6 pre-selected CNG fueling stations and analysed for their trace oil Carry-over. The measured total oil Carry-over ranged from 2.569 to 6.509 ppm. This test measurements were compared with those of previous studies to verify the results.

• Journal of Welding and Joining
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• v.9 no.3
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• pp.34-40
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• 1991

An automatic welding system was constructed with a personal computer to capture the welding data in addition to vision seam tracking for the gas metal arc welding process. The monitoring of welding signals is composed of the acquisition of welding voltage and current, obtained by using two differential amplifiers and A/D converters, and processing of the measured data. Using interrupt handing circuit for time sharing, two jobs of seam tracking and monitoring were performed at the required sampling time. Relations between welding signals and various welding circumstances were analyzed from the experimental results.

• Bulletin of the Korean Chemical Society
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• v.29 no.8
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• pp.1525-1532
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• 2008

An instrument was developed for the simultaneous determination of gas- and aerosol-phase nitrous acid (HONO). Gaseous HONO (HONO(g)) was sampled by a diffusion scrubber and particulate nitrite ($NO_2\;^-$(p)) was collected by a particle growth chamber. The collected samples were analyzed in time-sharing manner, based on the peroxynitrite-induced luminol chemiluminescence. The automated system was found to be sensitive with 13 pptv of detection limit, fast with 4 min. of sampling frequency, and simple and affordable to construct and operate. The system was optimized by adjusting the experimental parameters. The system was applied to the field measurement of gas- and particle-phase HONO during the springtime of 2004 in Gwangju, South Korea. HONO(g) concentrations varied diurnally from 200 pptv around 3 P.M. to 800 pptv at 5 A.M. The variation of $NO_2\;^-$(p) was not significant with the maximum of 240 pptv at 11 P.M. and the minimum of 170 pptv at 4 P.M., not displaying distinct characteristics.

• Journal of Climate Change Research
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• v.6 no.3
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• pp.175-184
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• 2015

In this study GC and PAS were used to calculate $N_2O$ concentration of exhaust gas from Wood Chip combustion system. Fuel supplied to the incinerator was collected and analyzed and then the analysis result was used to calculate $N_2O$ emissions. Tier 3 and Tier 4 Method were used to calculate the $N_2O$ emissions. Plant's Specific emission factor of $N_2O$ by Tier 3 Method was 0.35 kg/TJ, while default emission factor of Wood?Wood Waste proposed by 2006 IPCC G/L was 4 kg/TJ. So the $N_2O$ emission factor of this study was 3.65 kg/TJ lower compared to the IPCC G/L. The total emissions calculated by Plant's specific emission factor was 4.22 kg during the measuring period, but by Tier 4 Method it was 7.88 kg. This difference in emissions was caused by the difference of continuous measuring and intermittent sampling. It would be necessary to apply continuous measuring to calculate emissions of $Non-CO_2$ gas whose the density distribution is relatively high. However currently, according to the target management guideline of greenhouse gas and energy, the continuous measuring method to calculate greenhouse gas emission is applied only to $CO_2$. Therefore for reliable greenhouse gas emission calculation it would be necessary to apply continuous measuring to calculate $Non-CO_2$ gas emission.

• Proceedings of the KOSOMBE Conference
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• v.1992 no.11
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• pp.103-104
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• 1992

Automatic transmission of data from the blood analyzer to the request site is one of the most important part in hospital computerization. We have developed a system to automatically transmit the data from the atrial blood gas analyzer. In this system, HOST computer, FILE server, LAN(Local Area Network), 3270 Emulator and Multi-port card were integrated. Also, 3 blood gas analyser(NOVA Inc., USA) were connected to a single multi-port card which is attached in a personal computer for data acquisition. When specimen is collected from sampling sites, it is transfered to the lab. After analysis, the result is transmitted to the personal computer via serial communication between machine and multi-port card using interrupt method. Then, the patient's information (Name, Sex, etc.) is obtained from the HOST computer througth the emulator. The combined data(patient information & lab data) is transmitted to the each request site via LAN automatically. From the collected data, patient's previous data could be reviewed, and it could be used for the various statistics and the flow chart for clinical research. Also, we found that this system reduces the personal labor.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.3
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• pp.126-133
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• 2013

Recently, it was reported that complaints about problems being experienced with the performance of vehicles operating on autogas in Korea. The problem was being assumed due to contaminants in LPG and an oily material which was being deposited in vaporizer, injector in LPG fuel system. This study is focused on the analysis of contaminant of automobile parts on LPG fuel system. The sampling points of contaminants are injectors, fuel filters, vaporizer in automobile equipment and it was also investigated by GC-MS, ICP-AES, SIMDIS and EDS. According to results, it was presumed that this contaminants had been analyzed plasticizers with hydrocarbons with high boiling point, Fe from steel corrosion, greases from gas station.

• Journal of Korean Society for Atmospheric Environment
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• v.22 no.E1
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• pp.1-8
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• 2006

The purpose of this study was to evaluate the efficiency of a passive sampler in measuring atmospheric ammonia concentrations using chamber system. The ability of the passive sampler to quantitatively determine atmospheric ammonia gas was almost identical to that of the reference method (indophenol method). There was no significant difference between concentrations measured by the two methods. The detection and quantification limits of the ammonia passive sampler were 16.9 ppb and 25.3 ppb, respectively, for a 24-h sampling period. The average coefficient of variation between replicated samplers was $6.7{\pm}4.2%$. The concentrations measured by the two methods (passive sampler and indophenol method) were no significant difference with good a correlation (correlation coefficient=0.964).