• Journal of Bio-Environment Control
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• v.22 no.2
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• pp.100-107
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• 2013

Unlike general microwave, QRD (Quadratic Residue Diffusor) Microwave used in this study is known as a new technology that enhances the sterilization effect with low power because it is possible to induce the average sterilization by changing wavelength phase difference. Therefore, basic research was conducted on the function that could sterilize culture media for plant factory by using environmentally friendly and low energy consuming QRD Microwave. The results are as follows: It was confirmed that there was no external deformation in the polyurethane foam and rock wool medium when changing the microwave level between 2 and 8 kW in different water content of culture media. However, PDA solid media at 2 kW were not dissolved in 60 and 180 seconds. All of the media were dissolved in other processing. There was little difference in the microwave irradiation level and surface temperature of the strain according to the processing time between Bacillus sp. and Burkholderia sp. In the sterility test according to the microwave irradiation level and processing time, it was confirmed that both Bacillus sp. and Burkholderia sp. grew in the microwave level 2 kW regardless of time. In the microwave level 6 kW, all experimental groups except the processing of Burkholderia sp. for 60 seconds were sterilized, and all of Bacillus sp. was killed in the all experimental groups. In the microwave level 8 kW, it was confirmed that both Bacillus sp. and Burkholderia sp. were sterilized regardless of time. The temperature in microwave-processed media after contaminating strains to each medium was maintained at more than 100 in polyurethane foam and rock wool medium after 60 seconds. In general, it was shown that it was possible to sterilize after 60 seconds. Therefore, it is considered that Bacillus sp. and Burkholderia sp. which are the biggest problems in the plant factory can be adequately sterilized by QRD Microwave used in this study.

• Journal of Bio-Environment Control
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• v.26 no.3
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• pp.158-166
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• 2017

The object of this study was to improve tomato seedling quality in low temperature(below 7, $10^{\circ}C$ during night time or daily mean air temperature was $18^{\circ}C$) by application of silicate fertilizer. Six different silicate fertilizer concentrations (8, 16, 32, 64, 128, and 256mM) or water as the control were applied to tomato seedlings twice a week for 20 days. Positive effects were observed in the growth parameters of the seedlings treated with 16 and 32mM silicate fertilizer; the most effective concentration of silicate at which seedlings showed the best performance was 16mM. However, a high concentration of silicate (256mM) caused negative effects on the growth. The transpiration rate decreased alongside with the increase of silicate concentration up to 32mM, possibly due to the increased stomatal diffusive resistance. Silicate stimulated the growth and development of tomato seedlings, resulting in increased growth parameters and root morphology. However, no significant differences were observed among treatment numbers of soil-drenching wuth the silicate (6, 10, or 20 times with 16mM) for 20 days, suggesting that silicate treatment with 6 times may be sufficient to induce the silicate effects. The application of 16mM of silicate fertilizer reduced relative ion leakage and chilling injury during low temperature storage. In addition, the seedlings treated with silicate fertilizer recovered faster than those without silicate treatment after low temperature storage.

• Journal of Korean Tunnelling and Underground Space Association
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• v.19 no.4
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• pp.669-683
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• 2017

The objective of this study is to propose a modification of the previously proposed drainage system for catching the partial leakage of underground concrete structures. Two techniques were proposed for applying the drainage system only to the leaking parts. One was for conveying leaking groundwater to the collection point in the drainage system and the other was for conveying the collected groundwater to the primary drainage system of the underground concrete structure. Four waterproofing materials for conveying leaking groundwater to the catchment point of the drainage system, Durkflex made of porous rubber material, KE-45 silicone adhesive with super strong adhesion, Hotty-gel made of polymeric materials and general silicone adhesive were evaluated for waterproofing performance. Hotty-gel only showed perfect waterproof performance and the other three waterproof materials leaked. The modified drainage system with Hotty-gel and drainage pipe with fixed saddle to convey the leaking groundwater from the catchment point to the primary drainage system were tested on the concrete retaining wall. The waterproof performance and the drainage performance were evaluated by injecting 1,000 ml of water in the back of the modified drainage system at the 7-day, 14-day, 21-day, 28-day, 2-month and 3-month. There was no problem in waterproof performance and drainage performance of the modified drainage system during 3 months. In order to evaluate the construction period and construction cost of the modified drainage system, it was compared with the existing leaching repair method in surface cleaning stage, leakage treatment stage, and protective barrier stage. Total construction period and construction cost were compared in considering the contents of work, repair material, construction equipment, working time, and total number of workers. As a result of comparing and analyzing in each construction stage, it was concluded that the modified drainage system could save construction period and construction cost compared to the existing leaching repair method.

• Journal of Korean Tunnelling and Underground Space Association
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• v.22 no.5
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• pp.591-610
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• 2020

Concrete with activated carbon and titanium dioxide (TiO₂) has been used to reduce the particulate matter (PM) in underground structures (e.g., tunnels) due to the high performance of nitrogen oxides (NOx) abatement. Damage (e.g. crack, spalling, or detachment) can be caused by the environmental and ageing effects on the surface of the particulate matter reduction concrete, installed on the tunnel lining. Therefore, it is important to evaluate the existence of spalling on the concrete surface for maintaining performance of NOx reduction. In this study, a basic research was performed for feasibility of spalling evaluation using electrical resistivity characteristics. Given the test results, the electrical resistivity was decreased as the ratios of activated carbon (0~15%) and TiO₂ (0~25%) were increased for specimens. Under a dry condition, electrical resistivity of cement specimens, mixed with activated carbon and TiO₂, was decreased up to 2.3 times, compared with the normal cement specimen. In addition, under saturation conditions (degree of saturation: 85~98%), electrical resistivity of cement specimens with activated carbon, was decreased up to 3.5 times, compared with the normal cement specimen. Regardless of the condition (dry or saturated), the difference of electrical resistivity values shows the range of 2.3~2.8 times between the mixing specimen (with activated carbon (15%) and TiO₂ (25%)) and the normal cement specimen. This study can help to provide basic knowledge for spalling evaluation using the electrical resistivity on the surface of the particulate matter reduction concrete in tunnels.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.6
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• pp.529-532
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• 2000

To establish a food safety of dried layer, heat treatment effect on the bacterial density of dried layers was investigated. And a modified process developing experiment for dried layer products using closing type drying oven was carried out. tittle bacterial density difference on the dried layer products were found before and after heat treatment at $90^{\circ}C$ for 6 hrs called Hwaip treatment having been used for long term storage. Direct or indirect heat treatment of dried lavers using gas burner and frying pan reduced about 1 to 3 log cycle of viable cell count from $10^8\;CFU/g\;to\;10^5\;CFU/g$. Heat treatment by direct surface contact type cooking machine being used in the market place for cooked dried layer products could reduce the viable cell count on the layer product from $2.2{\times}10^5{\~}5.2{\times}10^7\;CFU/g\;to\;7.0{\times}10^2{\~}5.0{\times}10^5\;CFU/g$, Ultraviolet irradiation (20 W, 30 cm) to one or both side of the dried laver products reduced the viable cell count from $2.2{\times}10^6\;CFU/g\;to\;8.0{\times}10^5\;CFU/g\;and\;2.0{\times}10^5\;CFU/g$, respectively. The viable cell count of the dried layer products produced by modified process using a closing type dryer was about $10^3\;CFU/g$ and lower 3 log cycle than that in the products collected in market place and made by open type dryer.

• Proceedings of the CALSEC Conference
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• 2002.01a
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• pp.86-106
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• 2002

Informatization is a process that corporation's external environmental factors and internal environmental factors influence as complex. is a phenomenon that appears via this process. To evaluate that informatization was propeled well or informatization level is high can be dangerous work extremely by only once-over-lightly some factors, organization information ability is superior or infrastructure is constructed well. Therefore, an evaluation for industrial information systems that consider corporation's external environment and internal environment configurationally and objective estimation through this is required in national dimension. This research sorted types of business using types of business classification of 2001 EIII(Evaluation Indices of Industrial Informatization) laying stress on corporation's product and product production process for reflecting various industrial classification. And we are dividing whole our country corporations by manufacture industry, the construction industry, distribution industry, service industry, banking industry 5 types of business. To see such classed types industry classification from consistent viewpoint, we saw them within new framework, purchase, operation, physical distribution, marketing and sale. service etc. laying stress on primary businesses except support businesses of planning, financial management etc. To draw special quality of business center from primary business of each types of business, we draw industry classification Key Capability that centers when plans corporation's corporate strategy and information strategy. And we deducted industrial classification key production business connected with industry classification Key Capability. After drawing an evaluation items for industrial information systems in informatization analysis viewpoint laying stress on drawn businesses. Finally we did Case Study by making out an evaluation for industrial information systems questionnaire that considers special quality of manufacturing industry. Through EIII that consider the industrial classification, we could know that it explains the corporation's purchase, production, distribution in general and detail.

• Progress in Medical Physics
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• v.24 no.1
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• pp.48-53
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• 2013

Monte Carlo method has been known as the most accurate method for calculating absorbed dose in the human body, and an anthropomorphic phantom has been mainly used as a method of simulating internal organs for using such a calculation method. However, various efforts are made to extract data on several internal organs in the human body directly from CT DICOM files in recent Monte Carlo calculation using Geant4 code and to use by converting them into the geometry necessary for simulation. Such a function makes it possible to calculate the internal absorbed dose accurately while duplicating the actual human anatomical structure. Thus, this study calculated the absorbed dose in the human body by using Geant4 associating with DICOM files, and aimed to confirm the usefulness by compare the result with the measured dose using a Gafchromic EBT2 film. This study compared the dose calculated using simulation and the measured dose in beam central axis using the EBT2 film. The results showed that the range of difference was an average of 3.75% except for a build-up region, in which the dose rapidly changed from skin surface to the depth of maximum dose. In addition, this study made it easy to confirm the target absorbed dose by internal organ and organ through the output of the calculated value of dose by CT slice and the dose value of each voxel in each slice. Thus, the method that outputs dose value by slice and voxel through the use of CT DICOM, which is actual image data of human body, instead of the anthropomorphic phantom enables accurate dose calculations of various regions. Therefore, it is considered that it will be useful for dose calculation of radiotherapy planning system in the future. Moreover, it is applicable for currently-used several energy ranges in current use, so it is considered that it will be effectively used in order to check the radiation absorbed dose in the human body.

• Investigative Magnetic Resonance Imaging
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• v.18 no.1
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• pp.52-58
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• 2014

Purpose : To establish a pH measurement system for a mouse tumor study using a clinical scanner, to develop the $^1H$ and 31P radio frequency (RF) coil system and to test pH accuracy with phantoms. Materials and Methods: The $^1H$ and the $^{31}P$ surface coils were designed to acquire signals from mouse tumors. Two coils were positioned orthogonally for geometric decoupling. The pH values of various pH phantoms were calculated using the $^1H$ decoupled $^{31}P$ MR spectrum with the Henderson-Hasselbalch equation. The calculated pH value was compared to that of a pH meter. Results: The mutual coil coupling was shown in a standard $S_{12}$. Coil coupling ($S_{12}$) were -73.0 and -62.3 dB respectively. The signal-to-noise ratio (SNR) obtained from the homogeneous phantom $^1H$ image was greater than 300. The high resolution in vivo mice images were acquired using a $^{31}P$-decoupled $^1H$ coil. The pH values calculated from the $^1H$-decoupled $^{31}P$ spectrum correlated well with the values measured by pH meter ($R^2$=0.97). Conclusion: Accurate pH values can be acquired using a $^1H$-decoupled $^{31}P$ RF coil with a clinical scanner. This two-surface coil system could be applied to other nuclear MRS or MRI.

• Journal of the Mineralogical Society of Korea
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• v.22 no.2
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• pp.139-151
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• 2009

Mineralogical characteristics of secondary precipitate formed at some mineral water springs in Gyeongbuk Province, Korea were studied in relation to water chemistry. The chemical water types of mineral water springs are mostly classified as $Ca-HCO_3$ type, but $Na(Ca)-HCO_3$ and $Ca-SO_4$ types are also recognized. Ca, Fe, and $HCO_3\;^-$ are the most abundant components in the water. The pH values of most springs lie in 5.76${\sim}$6.81, except Hwangsu spring having pH 2.8. Saturation indices show that all springs are supersaturated with respect to iron minerals and oxyhydroxides such as hematite and goethite. The result of particle size analysis shows that the precipitate is composed of the composite with various sizes, indicating the presence of iron minerals susceptible to a phase transition at varying water chemistry or the mixtures consisting of various mineral species. The particle size of the reddish precipitate is larger than that of the yellow brown precipitate. Based on XRD and SEM analyses, the precipitate is mostly composed of ferrihydrite (two-line type), goethite, schwertmannite, and calcite, with lesser silicates and manganese minerals. The most abundant mineral fanned at springs is ferrihydrite whose crystals are $0.1{\sim}2\;{\mu}m$ with an average of $0.5\;{\mu}m$ in size, characterized by a spherical form. It should be interestingly noted that schwertmannite forms at Hwangsu spring whose pH is very low. At Shinchon spring, Gallionella ferruginea, one of the iron bacteria, is commonly found as an indicator of the important microbial activity ascribed to the formation of iron minerals because very fine iron oxides with a spherical form are closely distributed on surfaces of the bacteria. A genetic relationship between the water chemistry and the formation of the secondary precipitate from mineral water springs was discussed.

• Journal of Conservation Science
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• v.24
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• pp.23-36
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• 2008

The stone Buddhas and Shrine of Unjusa temple (Korea Treasure No. 797) in Hwasun formed in Koryo Dynasty are unique style which the Buddha faces each other the back parts of south and north within the stone Shrine. The stone Buddhas and Shrine are highly evaluated in historical, artistic and academic respects. But, the stone properties have been exposed in the open system various aspects of degradations weathered for a long time without specific protective facilities. The rock materials of the stone Buddhas and Shrine are about 47 blocks, and total press load is about 56.6 metric ton. The host rocks composed mainly of white grey hyaline lithic tuff and rhyolitic tuff breccia. In addition, biotite granite used as part during the restoration works. The chemical index of alteration for host tuffaceous rocks and the replacement granites range from 52.1 to 59.4 and 50.0 to 51.0, respectively. Weathering types for the stone Buddhas and Shrine were largely divided with physical, chemical and biological weathering to make a synthetic deterioration map according to aspects of damage, and estimate share as compared with surface area. Whole deterioration degrees are represented that physical weathering appeared exfoliation. Chemical weathering is black coloration and biological weathering of grey lichen, which show each lighly deterioration degrees. According to deterioration degree by direction of stone Buddhas and Shrine, physical weathering mostly appeared by 39.1% on the sorthern part, and chemical weathering is 61.2% high share on the western part. Biological weathering showed 38.3% the largest distribution on the southern part. Therefore, it is necessary to try hardening for the parts with serious cracks or exfoliations, remove secondary contaminants and organisms through regular cleaning. Also necessary to make a plan to remove moisture of the ground which causes weathering, and estimate that need established and scientific processing through clinical demonstration of conservation plan that chooses suitable treatment.