• Membrane Journal
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• v.17 no.4
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• pp.369-374
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• 2007

Polyacrylonitrile diagnostic membranes were prepared to measure blood glucose level of diabetics. Final absorbances at 680 nm through activated polyacrylonitrile membranes were measured at various concentration of glucose in plasma. The end-point results of K/S values obtained from the absorbances had a linear relationship toward the glucose concentration. The effect of temperature on the measurements of glucose concentration was studied. The stability of polyacrlonitrile diagnostic membranes was examined at RH 80%.

• Journal of Sensor Science and Technology
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• v.29 no.3
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• pp.211-214
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• 2020

Chlorine dioxide is very effective gas for sterilization or disinfection (in manufacturing), and does not produce harmful by-products after use. However, if its concentration exceeds 10 %, it become explosive and cannot be compressed or stored. Therefore, it is necessary to measure its concentration. In this study, the concentration of chlorine dioxide with a high oxidizing strength was measured using a metal oxide sensor. The sensor was a commercially available TGS series from Figaro. The sensitivity of the sensor was inversely proportional to a low concentration of chlorine dioxide gas below 6 ppm and returned to the initial resistance at about 6 ppm. When the gas concentration reached multiples of 10 ppm, resistance of the sensor increased to several megaohms.

• Korean journal of food and cookery science
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• v.13 no.3
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• pp.314-318
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• 1997

This study was conducted over eat-nut foods in Andong area to measure the salt concentration and to compare the result with the optimum gustation of salt concentration in usual diets. The results were as follows: 1. Mean salt concentration of eat-nut foods was similar to the optimum salt concentration by sensory evaluation. 2. The salt intake through the menu was about twice of the recommended intake by Korean Food Research. 3. The foods with a large serving size contributed to the increase of salt intake, suggesting that the serving size needs to be adjusted. 4. It is recommended that the consumption of high salt foods needs to be reduced while increasing that of fresh fruit and vegetable in the diet behavior on eat-out foods.

• Nuclear Engineering and Technology
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• v.54 no.11
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• pp.4231-4235
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• 2022

Considering the importance of deuterium in nuclear science including medical and industrial researches such as (BNCT) and nuclear reactors respectively, it is important to study various possible ways in addition to common methods for measuring its concentration. This study is an effort to measure deuterium concentration using PGNAA. The main idea is to calculate the area under 2.23 MeV gamma-rays photo peak resulting from neutron collision with Hydrogen atoms which are in mix with deuterium in samples. The study carried out by both simulation and experiment. Monte Carlo MCNPX2.6 code has been used for simulation and based on its acceptable results an experimental setup has been arranged. The coordination of results was in the range of R = 0.99 and R = 0.98 in simulation and experiment respectively. The accuracy of the study has been investigated by measuring the concentration of an unknown sample by both PGNAA and Fourier transform infrared spectroscopy (FT-IR) methods in which there were acceptable correlation between these two methods.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.4
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• pp.610-617
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• 2009

The aim of this study was to investigate the quality characteristics of Karedduk, Korean rice cakes, containing cactus (as Opuntia humifusa) fruit powder at a concentration of 0, 2, 4, 6 and 8% during three days of storage. The moisture content of the cooked cake just before storage ranged from 45.55～49.70%, indicating that the moisture content decreased as the amount of the powder added inceased. The L value, which is a measure of the lightness of the cake color decreased as the amount of added powder increased. In addition, the L value sharply decreased after one day of storage relative to its valve just after the cake was cooked. However, no significant changes were observed at longer storage times except at a fruit powder concentration of 2%. The a value, which is a measure of the redness, was significantly increased with an increase in the amount of added powder. The b value, which is a measure of the yellowness, was the same for all the treatments regardless of the amount of the powder added. The a and b values did not display any regular patterns in terms of the amount of powder added as a function of storage time. In regards to mechanical quality characteristics, the hardness and the gumminess of the cake just cooked tended to be increase with an increase in the amount of added powder indicating that no significant differences between the non-treatments and the treatments existed. The hardness of the cake did not change after two days of storage relative to when they were just cooked at all powder concentrations: however, the hardness of the cake after three days of storage was found to drop significantly with an increase in the amount of added powder. The cohesiveness of the cake right after cooking tended to decrease with an increase in the amount of added powder. The springiness of the cake right after it was cooked and on the second day of storage, did not significantly different as a function of powder concentration. The chewiness of the cake right after cooking increased with an increase in the amount of added powder. In the sensory test, the color and the flavor of the cake containing a powder concentration of 6% was found to be the highest. In addition and the chewiness significantly with an increase in the amount of added powder. In both taste and overall acceptability, the cake containing a powder concentration of 4% was determined to be the highest, showing no significant differences in taste relative to the cakes made with a powder concluded that it would be the best to cook Karedduk which a of cactus (Opuntia humifusa) fruit powder concentration of 4~6%.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.5
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• pp.533-538
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• 2012

In this study, we used an $O_2$-sensitive luminescent dye to measure the $O_2$ concentration of culture media around HeLa cells cultured in a microchannel. $[Ru(bpy)_3]^{2+}$, which dissolves easily in water and which has no phototoxic effect, was used as the $O_2$-sensitive dye. The ratiometric sensing method was applied by introducing calcein as the $O_2$-insensitive dye, in order to overcome the disadvantages of intensity-based sensing. By performing calibration with an amperometric $O_2$ sensor, we could calculate the exact concentration of $O_2$ in the culture media. We applied this technique to measure the $O_2$ concentration around the cultured cells in the microchannel. As expected, the $O_2$ concentration gradually decreased as the cells moved farther away from the channel. This method is expected to be applicable to the investigation of hypoxia, which occurs commonly in scaffolds.

• Journal of the Korean Society for Nondestructive Testing
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• v.37 no.1
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• pp.1-6
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• 2017

In this study, a terahertz time domain spectroscopy (THz-TDS) imaging technique was used to measure doping concentration and physical properties (such as refractive index and permittivity) of the doped silicon (Si) wafers. The transmission and reflection modes with an incidence angle of $30^{\circ}$ were employed to determine the physical properties of the doped Si wafers. The doping concentrations of the prepared Si wafers were varied from $10^{14}$ to $10^{18}$ in both N-type and P-type cases. Finally, the correlation between the doping concentration and the power of the THz wave was determined by measuring the powers of the transmitted and reflected THz waves of the doped Si wafers. Additionally, the doped thickness, the refractive index, and permittivity of each doped Si wafer were calculated using the THz time domain waveform. The results indicate that the THz-TDS imaging technique is potentially a promising technique to measure the doping concentration as well as other optical properties (such as the refractive index and permittivity) of the doped Si wafer.

• Journal of Space Technology and Applications
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• v.4 no.3
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• pp.220-231
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• 2024

This study deals with an experiment to measure ozone concentration in the atmosphere over the Korean Peninsula, Jeollabuk-do, using a helium balloon and analyze the change in atmospheric density based on the scale height. In the experiment, Arduino Uno was used to collect data and ozone concentration was measured using the MQ131 sensor. In addition, the BMP280 sensor was used to measure temperature and atmospheric pressure at various altitudes. The experimental results showed that the scale height of the atmosphere over the Korean Peninsula was 6,828.30 m, and the decreasing pattern of atmospheric density was confirmed based on this. In addition, by analyzing the graph of the measured ozone level, a phenomenon of a rapid decrease in the ozone level was observed between 8 km and 9 km altitude. These results can provide important information for understanding the atmospheric environment and ozone concentration changes and for environmental monitoring.

• Water Engineering Research
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• v.3 no.2
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• pp.135-142
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• 2002

This study investigates the effects of sediment on the flow characteristics such as velocity distribution, friction velocity, turbulent intensities, Reynolds stress, etc. Particle tracking velocimetry (PTY) is used to measure the vertical flow field. Results show that flow over the high bed-load concentration region has larger values of mean velocity and friction velocity and smaller values of turbulence intensities, compared to those for flow over the low bed-load concentration region.

• Proceedings of the Korean Environmental Health Society Conference
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• 2005.12a
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• pp.83-84
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• 2005

This research was performed to measure the concentration distribution of Bioaero sol in apartment houses in the region of Chungnam (Chunan, Asan) for 1 month, December, 2004. The results are as follows.