• Korean Chemical Engineering Research
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• v.48 no.1
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• pp.33-38
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• 2010

A microfluidic system has been developed using biomaterial for the measurement of cupric ion concentration. The cell-membrane-mimicking bilayer lipid membrane(BLM)-coated silver electrode was used for the sensing of cupric ion concentration. The silver-supported BLM could increase its stability. A silver-supported bilayer lipid membrane(s-BLM) was easily obtained using its self-assembling characteristics by immersing silver wire into lipid(phosphatidylcholine; PC) solution and then dipping into aqueous KCl solution. These s-BLMs were used to determine the relationship between $Cu^{2+}$ concentration and current crossing s-BLM. Their relationship showed high linearity and reproducibility. The calibration curve was constructed to express the relationship between $Cu^{2+}$ concentration and current in the $Cu^{2+}$ concentration range of 10 and $130{\mu}M$. This calibration curve was used to measure $Cu^{2+}$ concentration in an unknown sample. Microfluidic system with s-BLM was made of PDMS(polydimethyl siloxane) using typical soft photolithography and molding technique. This integrated system has various functions such as activation of the silver surface without cutting silver wire, coating of BLM on silver surface, injection of KCl buffer solution, injection of $Cu^{2+}$ sample and measurement of $Cu^{2+}$ concentration in the sample.

• Journal of the Korean GEO-environmental Society
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• v.19 no.3
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• pp.15-24
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• 2018

As electromagnetic waves are affected by electrical conductivity or permittivity, they are widely used to evaluate geotechnical characteristics. In this study, a probe for measuring electromagnetic waves using a time domain reflectometry is manufactured to evaluate heavy metal concentration in saline water. In the experiments, a copper is used as a heavy metal, and a probe is demonstrated with the concentration of copper. Solutions were set for 8 different copper concentration (0, 0.01, 0.05, 0.1, 0.5, 1, 5, 10 mg/L) in saline water with 3% salinity. The probe is coated by electrical insulating materials such as epoxy, top-coat, varnish, acrylic paint, heat-shrinkage tube to measure electromagnetic waves in saline water. The measured signals are compared according to coating material. As results, for probes coated with acrylic paint and heat-shrinkage tube, signal variation is not detected. For epoxy, top-coat, and varnish coated probes, the voltage decreases with an increase of copper concentration. Probes coated by epoxy at once and top coat can estimate under 5 mg/L of copper concentration and the probe coated by epoxy twice can estimate over 5 mg/L of copper concentration. This study shows that the probe using the time domain reflectometry can be used to evaluate the concentration of heavy metal in saline water by coating the probe with insulating material.

• Journal of environmental and Sanitary engineering
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• v.20 no.4 s.58
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• pp.21-30
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• 2005

This research was performed to measure the concentration distribution of bioaerosol in apartment houses in the region of Chungnam (Chunan, Asan) for 1 month, December, 2004. The results are as follows. 1. By using SDA method, the average concentration of total microbe and fungus in the air inside and outside apartment house below 4 years are $69,42cfu/m^3\;and\;15.66cfu/m^3$, while apartment house over 4 years, $214.58cfu/m^3\;and\;216.43cfu/m^3$, respectively With gravitational sedimentation method, the average concentration of total microbe and fungus of apartmenthouse below 4 years are $100.63cfu/m^3\;and\;22.83cfu/m^3$, while apartment house over 4 years, $216.43cfu/m^3\;and\;70.000cfu/m^3$, respectively. 2. The I/O ratio of floating germ of apartment house below 4 years and over 4 years are 2.87 and 5.12 for total microbe, and 3.32 and 8.28 for fungus, respectively. The I/O ratio of falling germ of apartment house below 4 years and over 4 years are 1.55 and 2.81 for total microbe, and 2.85 and 4.08 for fungus, respectively. The apartment house below 4 years shows a low I/O ratio in all cases. 3. The difference in concentration of microbe between inside master bedroom and living room of apartment house below 4 years is $13.183cfu/m^3$, total microbe, and $4.787cfu/m^3$, fungus, while, apartment house over 4 years, $43.531cfu/m^3$, total microbe, and $21.932cfu/m^3$, fungus. The measured differences are statistically significant. 4. Air sampler was used to verify the difference in concentration of microbe with the age of apartment house. The difference in concentration of total microbe and fungus for outside apartment house below 4 years and over 4 years are $49.82cfu/m^3$ and $3.78cfu/m^3$, respectively. The difference of inside living room shows $160.23cfu/m^3$ for total microbe and $28.01cfu/m^3$ for fungus, and the difference of inside master bedroom shows $225.43cfu/m^3$ for total microbe and $56.73cfu/m^3$ for fungus. The differences are statistically significant. The difference in concentration of outside apartment house below 4 years and years 4 years are $34.66cfu/m^3$, total microbe, and $15.66cfu/m^3$, fungus, while inside apartment house below 4 years and over 4 years, $196.93cfu/m^3,\;and\;78.67cfu/m^3$, respectively. The measured differences are statistically significant.

• Journal of the Korean Society of Radiology
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• v.14 no.7
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• pp.881-889
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• 2020

The objective of this study was to quantitatively measure the changes in radon concentration due to ventilation and air purification plants in the lower and upper floors of a building. This study measured and compared radon concentration in the lower and upper floors of the building by using a radon meter when the room was closed, it was ventilated, and air purification plants were installed at a specific time. One-way ANOVA was conducted to evaluate the effect of treatment (i.e., closure, ventilation, and air purification plants) on radon concentration. The results of this study showed that ventilation and air purification plants significantly decreased radon concentration in the lower and upper floors of the building, but the effect of ventilation and that of air purification plants were not significantly different. Therefore, it will be possible to reduce radon concentration effectively when ventilation and air purification plants are used appropriately.

• Journal of the Korean Society for Library and Information Science
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• v.48 no.2
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• pp.89-107
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• 2014

The purposes of this study are to analyze the effectiveness of public library reading programs for children in qualitative way and to apply the outcomes to identify areas to measure the success of library reading programs. Interviews were conducted with children who participated in '2013 Reading Books with Libraries' program and adults who were in charge of managing the program. Observations on the program were also conducted. The findings indicate that children who participated in '2013 Reading Books with Libraries' program positively changed in various aspects. Selected areas to measure the success of library reading programs include: reading behavior; attitude to books; awareness of libraries and librarians; participation of library reading programs; the ability to read aloud; the ability to comprehend stories by listening; aggression; the ability to express one's own feelings; speech ability; concentration power; and undiscovered potential. The elements that affect the success or failure of library reading programs include: librarian's enthusiasm on running the reading program; environmental condition of the community child care center; age differences between child participants; running style of the instructor's program; selection of books; child participants' reading abilities and interests in reading; available time for free voluntary reading.

• Journal of the Economic Geographical Society of Korea
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• v.18 no.1
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• pp.1-16
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• 2015

It is widely believed that increasing socio-economic polarization inspired by globalization and economic restructuring worsens residential segregation by class in Korean cities. However, the existing literature falls short in showing the recent changes of the residential segregation, particularly after the 1997 financial crisis, with reliable and systematic segregation measures. Noting that there are the two major dimension in residential segregation - evenness-concentration and exposure-clustering - this study introduced not only global measure (dissimilarity index and isolation/interaction index) but also local measures (location quotient and Local Moran's I) for each dimension. These measures are applied to the case study of Seoul in the 2000s. The class is defined by education attainment and the data is obtain through the MicroData System Service System(MDSS). The result shows that the residential segregation by education attainment persists through 2000s and even get worse in some dimension. More significantly, it turns out that high-class and low-class residence are nearly mirror-images of each other, indicating high segregation.

• YAKHAK HOEJI
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• v.41 no.6
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• pp.749-755
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• 1997

It has been reported that dose-dependent $Ca^{2+}$ increase by menadione in platelets could be measured by fluorescent dye, quin-2. The problems will be described here rel ating to measuring $Ca^{2+}$ in menadione-exposed platelets using fura-2 and fluo-3, widely used fluorescent indicators. Additions of menadione to fura-2 loaded platelets and their lysates resulted in marked reduction in fluorescence intensity at both 340nm ($Ca^{2+}$-unbound form) 380nm ($Ca^{2+}$-undbound form) excitation wavelengths. Fura-2 excitation spectra were overlapped with UV-visible absorption spectra of menadione, suggesting that light absorption by menadione itself could quench fluorescence generated by fura-2. Next approach was to use fluo-3 which has the higher wavelength (490nm) of excitation. Previous work demonstrated that treatment with probenecid to platelets was required to prevent fluo-3 dye leakage. However, probenecid itself was proven to be inadequate to measure the concentration of intracellular $Ca^{2+}$; by reducing menadione-induced cytotoxicity in platelets. Our results suggest that it is not feasible to measure $Ca^{2+}$ in platelets by using fura-2 and fluo-3 in the presence of probenecid, and cautions should be taken to measure changes of intracellular $Ca^{2+}$ levels by fluorescent dyes following chemical exposure.

• Clinical and Experimental Reproductive Medicine
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• v.32 no.4
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• pp.301-314
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• 2005

Objective: Rebamipide is a propionic acid derivative that has an action of the inhibition of superoxide production and removal of hydroxyl radical with the sperm incubation and cryopreservation. In the present study, to investigate whether rebamipide is useful to treat male infertility and sterility, the author observed the antioxidative effects in patient with male infertility and also examined its absorption and distribution in rat genital organ. Methods: To measure the distribution of rebamipide in reproductive organ in the rat, carbon indicated rebamipide, $^{14}C-OPC-12759$, was orally administered to 10 Spraque-Dawley rats and its organ concentration in serum, liver, kidney, stomach, duodenum, colon, urinary bladder, seminal vesicle, epididymis and testicle were measured each time after 0.5, 1, 2, 4, 8 and 24 hours by using HPLC fluorescent method. The concentrations in semen were measured by HPLC fluorescent method in a sample of 50 infertile males who took 900 mg of rebamipide daily for 3 months. To measure the antioxidative effect and fertility rate for 3 months, each month before and after the treatment, sperm motility, vitality, the oxygen free radical formation, level of peroxidation, fetilizing capacity of semen sample which were obtained from infertile male patients by masturbation after at least 48 hours abstinence were analyzed by computer assisted semen analyzer, eosin-nigrosin stain, chemiluminescence, thiobarbituric acid method and hypo-osmotic swelling test. Simultaneously in a sample that wanted baby, both pregnancy and delivery were researched. Results: The $^{14}C-OPC-12759$ concentration in the body of white rats was highest in gastrointestinal organ like stomach, smal intestine and duodenum and followed by genital organ like seminal vesicle, testis and epididymis. The rebamipide concentration in semen of infertile males was $220.77{\pm}327.84ng/mL$ (SD) which showed a large deviation but it was higher than serum which was $126{\pm}76ng/mL$ (SD). In the infertile males, after the treatment with rebamipide, the level of seminal reactive oxygen species (ROS) and lipid peroxidation have significantly decreased in duration of the treatment (p<0.05) and sperm vitality and fertilizing capacity except sperm motility significantly improved on post treatment of 2~3 months (p<0.05). Out of the 41 cases who hoped for pregnancy, 15 cases (36.6%) became pregnant and 12 cases had childbrith, 2 cases had miscarriage and one case is ongoing. The side effect was observed in 1 case (2%) which experienced diarrhea but it was lost spontaneously. Conclusions: We conclude from this study that rebamipide showed relatively high tendancy of absorption and excretion in the genital organ. In infertile males who had elevated ROS in semen, by specifically inhibiting the cell damage from the antioxidation, a way to preserve sperm motility, vitality and fertilizing capacity was confirmed.

• Journal of Conservation Science
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• v.26 no.4
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• pp.397-406
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• 2010

The most ideal method to measure the water-soluble $Cl^-$ ion eluted from iron artifacts is conducting the analysis on desalting solution by Ion Chromatography. But most institutes related to cultural heritages use Cl meter by reason of lack of budget and experts. This study evaluated reliability and stability between Cl meter and Ion Chromatography by doing cross-validation with results from two methods to detect $Cl^-$ ion of desalting solution. From D.I water, extremely small quantities of $Cl^-$ ion was detected by the influence of remaining water-soluble $Cl^-$ ion at the electrode of Cl meter and water-soluble $Cl^-$ which remains in Sodium sesquicarbonate, components of reagent was detected as well. The first desalting solution had the most $Cl^-$ ions, $Cl^-$ ion slightly decreased from the second to the fourth desalting solution and tend to decrease again at the stage of dealkalified in D.I water. Each Cl meter has the standard deviation according to the measured numbers and the higher concentration of $Cl^-$ ion the desalting solution has, the wider the deviation is. But when the concentration of $Cl^-$ ion is low, it was stable to use Cl meter to detect the concentration of $Cl^-$ ion from iron artifacts because there is the small deviation, It is thought that conductivity meter method is not suitable for measuring $Cl^-$ ion, because the electrical conductivity of alkaline solution is too high to measure $Cl^-$ ion.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.3
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• pp.244-250
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• 2007

Membrane inlet mass spectrometer (MIMS) has been used to accurately quantify dissolved gases in liquid samples. In this study, the MIMS system was applied to measure dissolved methane in seawater and sediment porewater. To evaluate the accuracy of the measurement, liquid samples saturated with different methane partial pressure were prepared and the methane concentrations were quantified with the MIMS system. The measured values correspond well with the expected values calculated from solubility constants. The standard error of the measurements were $0.13{\sim}0.9%$ of the mean values. The distribution of dissolved methane concentration in seawater of the South Sea of Korea revealed that the physical parameters primarily control the methane concentration in sea water. The MIMS system was effective to resolve the small dissolved methane difference among water masses. The probe type inlet in MIMS system was proven to be effective to measure porewater methane concentration.