• Journal of the Korea Institute of Building Construction
• /
• v.21 no.3
• /
• pp.189-194
• /
• 2021

LIBS has been attracting attention as an analytical method capable of real-time measurement without sample preparation. In this study, a Lab. scale LIBS device was fabricated to examine the applicability and reproducibility of LIBS in the analysis of chloride contents in mortar. The existing analysis method and LIBS analysis were performed simultaneously on the mortar test specimen with the chloride content adjusted. Compared to the chloride content condition of the mortar, the XRF and Potentiometric Titration results also showed a similar trend. As a result of LIBS analysis, chlorine ions were detected at a wavelength of 837.59 nm according to the chloride content condition. In order to improve the precision in various concentration ranges, the LIBS signal amplification of about 50 times through the electric field enhancement was implemented. Through the verification of the aqueous solution-based reproducibility, a high correlation between the LIBS signal strength and the Cl concentration was confirmed, and the possibility of applying LIBS to the durability diagnosis of concrete damage by chloride was confirmed.

• Progress in Medical Physics
• /
• v.22 no.4
• /
• pp.206-215
• /
• 2011

The purpose of this was to investigate the measurement of fluence dose map for the specific patient quality assurance. The measurement of fluence map was performed using 2D matrixx detector. The absorbed dose was measured by a glass detector, Gafchromic film and ion chamber in Hybrid Optimized VMAT Phantom (HOVP). For 2D Matrixx, the results of comparison were average passing rate $85.22%{\pm}1.7$ (RT_Target), $89.96%{\pm}2.15$ (LT_Target) and $95.14%{\pm}1.18$ (G4). The dose difference was $11.72%{\pm}0.531$, $-11.47%{\pm}0.991$, $7.81%{\pm}0.857$, $-4.14%{\pm}0.761$ at the G1, G2, G3, G4. In HOVP, the results of comparison for film were average passing rate (3%, 3 mm) $93.64%{\pm}3.87$, $90.82%{\pm}0.99$. We were measured an absolute dose in steep gradient area G1, G2, G3, G4 using the glass detector. The difference between the measurement and calculation are 8.3% (G1), -5.4% (G2), 6.1% (G3), 7.2% (G4). The using an Ion-chamber were an average relative dose error $-1.02%{\pm}0.222$ (Rt_target), $0.96%{\pm}0.294$ (Lt_target). Though we need a more study using a transmission detector. However, a measurement of real-time fluence map will be predicting a dose for real-time specific patient quality assurance in volume modulated arc therapy.

• Food Science and Preservation
• /
• v.20 no.6
• /
• pp.791-797
• /
• 2013

This study was conducted to investigate the changes in the composition and microbiological properties of domestic sun-dried salt (white and gray salts) according to their collection time and production method. The results showed that the moisture contents of the white and gray sun-dried salts were 10.4~13.2% and 5.2~8.0%, respectively, and the sand contents were 0.1% and 0.2~0.3%, respectively, according to the month. Several samples exceeded the criteria of 15% moisture content and 0.2% sand content. The ash content and salinity of gray salt (below 85% and 90%, respectively) were higher than those of white salt (both below 80%). The total chloride contents of the salts collected in September and October were slightly lower than that of the others and exceeded the criteria of above 40%. In the case of mineral contents, there was no significant difference among the collection times because the analyses showed a marked deviation. The microbiological analysis showed that there was no significant difference among the production method, but the salt samples collected in September and October had relatively high detection rates of total aerobe, staphylococci, and halophilic bacteria.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.19 no.2
• /
• pp.169-175
• /
• 1986

This study was carried out to evaluate the water quality of spring waters in Pusan area (see Fig. 1). In this experiment, one hundred and forty water samples were collected at 20 stations from July to December 1985. Range and mean value of constituents of the samples were as follows ; pH 6.2-8.2, 7.07 ; water temperature $4.0-23.5^{\circ}C,\;15.9^{\circ}C$ ; electrical conductivity $0.228{\times}10^{2}-2.125{\times}10^2{\mu}{\mho}/cm,\;0.860{\times}10^2{\mu}{\mho}/cm$; chloride ion 3.28-19.3mg/l, 6.81mg/l ; nitrite-nitrogen ND-0.221 mg/l, 0.017mg/l ; nitrate-nitrogen ND-6.779mg/l, 0.877 mg/l ; phosphate-phosphorus ND-0.105mg/l, 0.021mg/l ; silicate-silicious 2.12-22.70mg/l, 9.04mg/l, respectively. Especially, electrical conductivity, chloride ion, nitrite-nitrogen, nitrate-nitrogen, and silicate-silicious of the station 11 (Millakdong) were higher than those of others as $1.815{\times}10^2{\mu}{\mho}/cm$, 13.5mg/l, 0.076mg/l, 4.772mg/l and 14.07mg/l. Range and geometric mean value of total coliform and fecal coliform MPN's of the samples were 0-1,500/100ml, 13-470/100ml and 0-460/100ml, 2-32/100ml. Composition of coliform was $26.37\%$ Escherichia coli group, $21.98\%$ Citrobacter freundii group, $37.36%$ Entrobacter aerogenes group and $14.29\%$ others.

• Progress in Medical Physics
• /
• v.18 no.2
• /
• pp.87-92
• /
• 2007

A thermal neutron beam facility utilizing a typical tangential beam port for Neutron Capture Therapy was installed at the HANARO, 30 MW multi-purpose research reactor. Mixed beams with different physical characteristics and relative biological effectiveness would be emitted from the BNCT irradiation facility, so a quantitative analysis of each component of the mixed beams should be performed to determine the accurate delivered dose. Thus, various techniques were applied including the use of activation foils, TLDs and ionization chambers. All the dose measurements were perform ed with the water phantom filled with distilled water. The results of the measurement were compared with MCNP4B calculation. The thermal neutron fluxes were $1.02E9n/cm^2{\cdot}s\;and\;6.07E8n/cm^2{\cdot}s$ at 10 and 20 mm depth respectively, and the fast neutron dose rate was insignificant as 0.11 Gy/hr at 10 mm depth in water The gamma-ray dose rate was 5.10 Gy/hr at 20 mm depth in water Good agreement within 5%, has been obtained between the measured dose and the calculated dose using MCNP for neutron and gamma component and discrepancy with 14% for fast neutron flux Considering the difficulty of neutron detection, the current study support the reliability of these results and confirmed the suitability of the thermal neutron beam as a dosimetric data for BNCT clinical trials.

• Journal of radiological science and technology
• /
• v.33 no.2
• /
• pp.127-132
• /
• 2010

The purpose of this study is to measure scattered ray which is occurred except for Z-axis range of the detector in MDCT's iso-center and present the basic data about the standard for reduction of scattered ray. The development of MDCT brings out the enlargement of beam thickness to the patient's Z-axis, which distributes to the increase in exposure dose according to the rise of scattered ray. Also MDCT brings out the increase of scattered ray about 4times more than SDCT. To evaluate scattered ray according to the change of beam thickness on MDCT, we measured scattered ray of MDCT's Z-axis beam thickness by using one 16-slice CTs and two 64-slice CTs. We used the ionization chamber 60ml 2026C as the equipment of measurement. In our results, we found out that the change of scattered ray according to the beam thickness in the same kVp has increase of scattered ray. Secondly we found out the increase of scattered ray according to the increase of kVp. Lastly we found out the decrease of scattered ray according to the increase of the distance from the ionization chamber.

• Korean journal of applied entomology
• /
• v.13 no.1 s.18
• /
• pp.1-10
• /
• 1974

The activities of pectolytic and cellulolytic enzymes produced from slices of ginseng root infected with Cylindrocarpon destructains(Zins.) Scholtern were proportional to each concentration and reaction time. Activities of cellulase(Cx), endo-polygalacturonase(endo-PG), endo-polymethylg-alacturonase(endo-PMG), exo-polygalacturonase(exe-PG), and exe-polymethylgalacturonase(exo-PMG) were maximum on the 4th day after inoculation. No endo-PG and endo-PMG were detected at the first and second days, while exo-PG exo-PMG were active. On the 6th day, all pectic enzymes were completely lost, whereas Cx remained at a high concentration. pH optima of Cx, endo-PG, endo-PMG, exo-PG, and exo-PMG were 6.0, 5.5, 8.0, 7.0 to 7.5, and 8.5, respectively. Temperature optima of Cx, endo-PG, endo-PMG exo-PG, and exo-PMG were $66^{\circ}C\;53^{\circ}C\;41^{\circ}C\;37^{\circ}C\;and\;40^{\circ}C$, respectively. Cx was only inhibited by $0.05M\; Hg^{++}$ among 16 ions tested. Inhibitory effects of ions on pectolytic enzymes varied, however$M Fe^{+++}\;and\;0.05M\;Al^{+++}$ were the best in general. Among 8 fungicides, none of them inhibited all the enzymes studied at $0.1\%$, active ingredients. Exo-PG were highly inhibited by all of the fungicides, of which difolatan was the most inhibitory to all the pectic enzymes. $Ca^{++}\; at\; 0.02M\; and\;Fe^{+++}\;at\;0.02M$ completely inhibited all the pectolytic enzymes, and Cx was inhibited $30\%$ and $70\%$ at the same concentration, respectively Formalin almost inhibited exo-PG and exe-PMG at $0.8\%$ but not the other enzymes especially Cx. Difolatan at $0.8\%$ inhibited all the enzymes concerned above $80\%$. The cellulolytic and pectolytic enzymes of C. destructans must be closely associated with the ginseng root rot and should be inhibited to control the disease effectively.

• Journal of the Korean Society of Radiology
• /
• v.17 no.6
• /
• pp.903-909
• /
• 2023

The purpose of this study is to compare and analyze the effect of changes in the patient's central position on the exposure dose and image quality of surrounding organs during a chest lateral examination using an Auto Exposure Control(AEC). The experiment was conducted on a human body phantom. A needle was attached to the lower part of the center of the coronal plane of the phantom, and a lead ruler was attached to the lower part of the detector so that the 50 cm point was located at the lower center of the AEC ion chamber. The exposure conditions were 125 kVp, 320 mA, the distance between the source and the image receptor was 180 cm, and the exposure field size was 14 × 17 inches. Only one AEC ion chamber was used at the bottom center, and the density was set to '0' and sensitivity to 'Middle', and the central X-ray was incident vertically toward the 6th thoracic vertebra. With AEC mode applied, the 50 cm point of the needle and lead ruler were aligned and the phantom was moved 5 cm toward the stomach (F5) and 5 cm toward the back (B5), and the dose factor was analyzed by measuring ESD. The ESD of the thyroid gland according to the change in patient center position was 232.60±2.20 μGy for Center, 231.22±1.53 μGy for F5, and 184.37±1.19 μGy for B5, and the ESD of the breast was 288.54±3.03 μGy for Center, F5 was 260.97±1.93 μGy, B5 was 229.80±1.62 μGy, and the ESD of the center of the lung was 337.02±3.25 μGy for Center, F5 was 336.09±2.29 μGy, and B5 was 261.76±1.68 μGy. As a result of comparing the average values of dose factors between each group, the difference in average values was statistically significant (p<0.01), and each group appeared to be independent. As a result of the study, there was no significant difference in the dose to the thyroid, breast, and center of the lung according to the change in the patient's central position, except for the breast (10%) when the patient moved forward about 5 cm. However, movement of about 5 cm posteriorly resulted in an average dose reduction of 23.7%. Additionally, when the patient's central position was moved to the rear, image quality deteriorated.

• Journal of Korean Society of Forest Science
• /
• v.88 no.4
• /
• pp.510-522
• /
• 1999

The air pollutants ; $SO_2$, $SO{_4}^{-2}$, $NO{_3}^-$, $Cl^-$ are absorbed into soils through falling with dusts and rain from the atmosphere. The sources of heavy metal contaminants in the environments are agricultural and horticultural materials, sewage sludges, fossil fuel combustion, metallurgical industries, electronics and waste disposal etc.. The soils and hydrosphere can be polluted on the way of the circulation of these heavy metals. Studied pollutant anions are $SO{_4}^{-2}$, $NO{_3}^-$ and $Cl^-$ and heavy metals are Se, Mo, Zn, Cd, Pb, Mn, Cr, Co, V, As, Cu and Ni which are the elements to be concerned with the essentials for plants, with animal and human health. This study is with the aim of selecting the species of roadside trees and green space trees which have excellent absorption of air pollutants and heavy metals from the atmosphere and the soils in the urban area. Two areas are designated to carry out this study : urban area ; Kwangju city and rural area ; the yard of Forest Environment Institute of Chollanam-do, at Sanje-ri, Sampo-myum, Naju city, Chollanam-do (23km away from Kwangju). This study is carried out to understand the movement of anions and heavy metals from the soils to the trees in both areas, the absorption of anions and heavy metals from atmosphere into leaves and the amounts of anions and heavy metals in leaves and fine roots(< 1mm dia.) of roadside trees and green space trees in Kwangju and trees in the yard of Forest Environment Institute of Chollanam-do. The tree species selected for this study in both areas are Ginkgo biloba, Quercus acutissima, Cedrus deodara, Platanus occidentalis, Robinia pseudoacacia, Alnus japonica. Metasequoia glyptostroboides. Zekova serrata. Prunus serrulata var. spontanea, and Pinus densiflora. The results of the study are as follows : 1. $SO{_4}^{-2}$, $NO{_3}^-$ and $Cl^-$ concentrations are higher in the soils of the urban area than in those of the rural area, and $NO{_3}^-$ and $SO{_4}^{-2}$ are higher in the leaves than in the roots due to the absorption of the these pollutants through the stomata. 2. Ginkgo biloba, Robinia pseudoacacia. Zekova serrata, Quercus acutissima, and Platanus occidentalis can be adequated to the roadside trees and the environmental trees due to their good absorption of $NO{_3}^-$ and $SO{_4}^{-2}$. 3. Heavy metals in the soils of both areas are in the order of Mn > Zn > V > Cr > Pb > Ni > Cu > Mo> Cd, and in the leaves and roots of the trees in the both areas are in the order of Mn>Zn>Cr>Cu>V>Ni. Both orders are similar ones except V. There are more in the urban soils than in the rural soils in amount of Mn, Zn, Pb, V, Cu. 4. It is supposed that there is no antagonism between Mn and Zn in this study. 5. Se, Co and As are not detected in the soils, the leaves and the roots in both areas. Sn, Mo, Cd and Pb are also not detected in the leaves and roots in spite of considerable amount in the soils of both areas.

• Journal of Environmental Science International
• /
• v.12 no.6
• /
• pp.665-676
• /
• 2003

To investigate the chemical characteristics of PM$\_$2.5/ in Seoul, Korea, atmospheric particulate matters were collected using a PM$\_$10/ dichotomous sampler including PM$\_$10/ and PM$\_$2.5/ inlet during the period of October 2000 to September 2001. The Inductively Coupled Plasma-Mass Spectromety (ICP-MS), ion Chromatography (IC) methods were used to determine the concentration of both metal and ionic species. A statistical analysis was performed for the heavy metals data set using a principal component analysis (PCA) to derived important factors inherent in the interactions among the variables. The mean concentrations of ambient PM$\_$2.5/ and PM/sub10/ were 24.47 and 45.27 $\mu\textrm{g}$/㎥, respectively. PM$\_$2.5/ masses also showed temporal variations both yearly and seasonally. The ratios of PM$\_$2.5/PM$\_$10/ was 0.54, which similar to the value of 0.60 in North America. Soil-related chemical components (such as Al, Ca, Fe, Si, and Mn) were abundant in PM$\_$10/, while anthropogenic components (such as As, Cd, Cr, V, Zn and Pb) were abundant in PM2s. Total water soluble ions constituted 30∼50 % of PM$\_$2.5/ mass, and sulfate, nitrate and ammonium were main components in water soluble ions. Reactive farms of NH$_4$$\^$+/were considered as NH$_4$NO$_3$ and (NH$_4$)$_2$SO$_4$ during the sampling periods. In the results of PCA for PM$\_$2.5/, we identified three principal components. Major contribution to PM$\_$2.5/ seemed to be soil, oil combustion, unidentified source. Further study, the detailed interpretation of these data will need efforts in order to identify emission sources.