• Elastomers and Composites
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• v.54 no.1
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• pp.70-76
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• 2019

The function and purpose of the marine rubber fender, to prevent the damage of the ship and the mooring while the ship is being attached to the pier. However, maintenance of the fender after installation is not enough, because it is generally handled as an attachment facility. Estimation the life of a marine rubber fender is important in the maintenance of a port. When manufacturers design and produce marine rubber fenders, they do so according to various conditions such as the reaction force acting on the hull and docking vessel and deformation after absorbing the kinetic energy of the ship. In this study, a method for predicting and evaluating service life from the product design and development stage was established, in order to evaluate the durability of the marine rubber fenders. The SSp-300H and HSP-300H models were used to predict the service life. The method developed in this study, is expected to predict the service life of the marine rubber fender accurately and in a comparatively shorter time, thereby contributing to the evaluation standard and quality stability of the product.

• Korean Journal of Plant Resources
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• v.34 no.6
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• pp.566-574
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• 2021

This research was carried out to investigate the correlation between soil chemical properties and bioactive compounds of Acer tegmentosum Maxim. The methods of determining bioactive compounds were determined by high performance liquid chromatography, that contained (-)-gallocatechin (0.04±0.01 ~ 0.43±0.28%), salidroside (0.90±0.06 ~ 3.86±0.59%), tyrosol (0.03±0.00 ~ 0.43±0.00%), (-)-catechin (0.05±0.01 ~ 0.37±0.14%), 6'-O-galloylsalidroside (0.02± 0.01 ~ 0.31±0.06%), (-)-epicatechin-gallate (0.01±0.00 ~ 0.04±0.01%). The soil chemical properties analysis such as soil pH, electric conductivity (EC), organic matter (OM), total nitrogen (TN), available phosphate (Avail. P₂O₅), exchangeable cation and cation exchange capacity (CEC) were performed following the standard manual. The correlation analysis between soil chemical properties and bioactive compounds of A. tegmentosum, soil pH, available phosphate and exchangeable cation (Ca²⁺ and Mg²⁺) were negatively correlated with content of salidroside. On the other hand, soil exchangeable cation (Na⁺) showed positive correlation with content of salidroside. The results of this study was able to investigate the correlation between soil chemical properties and bioactive compounds of A. tegmentosum.

• Structural Engineering and Mechanics
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• v.83 no.3
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• pp.387-400
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• 2022

The practice of using encased steel-concrete columns in medium to high-rise structures has expanded dramatically in recent years. The study evaluates existing methodologies and codal guidelines for estimating the ultimate load-carrying characteristics of concrete-encased short columns experimentally. The present condition of composite column design methods was analyzed using the Egyptian code ECP203-2007, the American Institute of Steel Construction's AISC-LRFD-2010, Eurocode EC-4, the American Concrete Institute's ACI-318-2014, and the British Standard BS-5400-5. According to the codes, the axial load carrying characteristics of both the encased steel and concrete sections was examined. The effect of load-carrying capacities in different forms of encased steel sections on encased steel-concrete columns was studied experimentally. The axial load carrying capacity of twelve concrete-encased columns and four conventional reinforced columns were examined. The conclusion is that the confinement was not taken into account when forecasting the strength and ductility of the encased concrete, resulting in considerable disparities between codal provisions and experimental results. The configuration of the steel section influenced the confining effect. Better confinement is achieved with the laced and battened section than with the infilled steel tube reinforced and conventionally reinforced section. The ECP203-2007 code reported the most conservative results of all the codes used.

• Analytical Science and Technology
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• v.36 no.4
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• pp.152-160
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• 2023

Adenosine and cordycepin are bioactive compounds with health benefits. Therefore, both substances are often used to assess the quality of Cordyceps products. Optimization and validation of the HPLC/DAD method for determining two nucleosides were studied. The samples were prepared using an ultrasound-assisted extraction (ultrasonic bath). The result was optimal conditions for aqueous extraction, an extraction time of 35 min, and an extraction temperature of 40 ℃. The Chromatographic separation was achieved using a reverse phase column (InfinityLab Poroshell 120 EC-C18, 4.6 × 250 mm, 2.7 ㎛) at 30 ℃ with a mobile phase gradient elution of water and methanol at a flow rate of 0.7 mL/min. The eluents were monitored via a diode array detector at 260 nm. Two nucleosides were separated by less than 12 min after injection. The developed method was found to be excellent linear (r² > 0.9999), accurate (% recovery 95.34-98.51), and precise (% relative standard deviation < 2.0). The limit of detection (LOD) and quantification (LOQ) were 0.45 and 1.38 mg/mL for adenosine and 0.47 and 1.43 mg/mL for cordycepin, respectively. This method was satisfactory for simultaneously quantitating two nucleoside contents, which were used to evaluate Cordyceps products.

• Journal of Korean Society of Environmental Engineers
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• v.39 no.5
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• pp.237-245
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• 2017

This study was aimed at investigating effluent water quality and proposing reuse possibilities for 12 sewage treatment plants discharged more than $5,000m^3/day$ in order to recycle the sewage treatment plant effluent of Jeollabuk-do effectively. Additionally, a laboratory scale test for reprocessing water discharge was performed. Categories of reclaimed sewage water reuse were divided into 7 topics and analyzed a total of 28 items including 16 heavy metals based on water quality standard. As a results, color, BOD, TN, chloride and Electrical Conductivity (EC) exceeded reused water quality standard. In particular, color and TN exceeded in 8 and 5 sewage treatment plants, respectively. The value of chloride and EC were high in sewage treatment plants including the food and industrial wastewater. At 4 sewage treatment plants were possible to reuse without re-treatment. The laboratory scale test was conducted to SandFilter (SF)-Granular Activated Carbon (GAC)-MicroFiltraion (MF)-Reverse Osmosis (RO). Both the removal efficiencies and economic feasibility of total E. coli., color and Suspended Solid (SS) suited in case using the SF-GAC treatment method. The removal of chloride and EC had little effect in the case of SF-GAC-MF system, but RO showed over 90% of removal efficiency. After using SF-GAC process only, the concentration of $UV_{254}$ decreased sharply from 0.3651 /cm to 0.0306 /cm and it showed over 92% of removal efficiency rate. In conclusion, for the effective reuse of sewage discharged water, water quality and the surrounding terrain of treatment plants should be all taken into account. If it needed for the reprocessing, both the selection for treatment and economic combination treatment methods will have to be considered.

• Journal of Korean Society of Forest Science
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• v.100 no.2
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• pp.142-148
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• 2011

This study was carried out to clarify the change characteristics of stream water quality by type of forest from June to August, 2009 in three stands (Castanea crenata, Pinus densiflora and Plantation Land) of Samgye-ri Naedong-myeon Jinju-si Gyeongsangnam-do. The pH of stream water in three stands was highest in Pinus densiflora (pH 7.18) followed by Castanea crenata (pH 6.90) and Plantation land (pH 6.90) while the electrical conductivity of stream water was highest in Plantation land followed by Castanea crenata stand and Pinus densiflora stand was the lowest. Cations contents of stream water in three stands were high in order of $Ca^{2+}$, $Na^{+}$, $Mg^{2+}$, $K^{+}$, and $NH_{4}{^{+}}$. But anions of stream water in Castanea crenata stand and Pinus densiflora stand were high in order of $SO_{4}{^{2-}}$, $Cl^{-}$ and $NO_{3}{^{-}}$ while those of stream water in Plantation land were high in order of $SO_{4}{^{2-}}$, $NO_{3}{^{-}}$ and $C\lambda^{-}$. The stream water in three stands was significant at pH, EC, $NO{^{3-}}$, $Ca^{2+}$, $Mg^{2+}$, $Na^{+}$, $Cl^{-}$, TNU and Color by duncan test. These results indicate that quality of stream water have a difference among three stands. The level of pH, $NH_{4}{^{+}}$, $Cl^{-}$, $SO_{4}{^{2-}}$ and $NO_{3}{^{-}}$ of stream water in three stands were within the domestic use standard for drinking water. but turbidity and color of stream water were more than that of domestic use standard for drinking water. Therefore, non-point sources like urban forest watersheds which are soil erosion and fertilizer application lands should be taken to the appropriate mitigation measures if they are to be used as source of drinking water.

• Journal of Animal Environmental Science
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• v.18 no.3
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• pp.229-234
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• 2012

Disinfecting contaminated swine manure with FMD (Foot-and-Mouth Disease) and pathogenic viruses is very important for maintaining sanitized environment. However, very few research reported on this subject, especially post-disinfection to utilize the wastes as a renewable resource. This research is carried out to obtain basic information for chemical treatment in FMD SOP (Standard Operating Procedure, Korea) of contaminated swine manure. Using lime, sodium hydroxide, citric acid and hydrochloric acid, described in FMD SOP, the effects of chemical treatments on livestock manure were compared in this paper. Four combinations of alkali-acid treatments and four kinds of acid-alkali combinations were tested to find out the effective method. Total coliform bacteria in contaminated swine manure, $1.6{\times}10^4$ CFU/100 ml, decreased to the range of 1/1000~1/100 in all treatments. Some specific disinfectants increases BOD (Biochemical Oxygen Demand) and EC(Electric Conductivity), especially, alkaline treatments increases ammonia level than acid treatments. These findings suggest that the treatment methods should be considered as an important environmental factor in post-disinfection of contaminated animal manure with pathogenic microorganisms.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.4
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• pp.457-462
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• 2014

This study was conducted to evaluate basic seed characteristics such as morphological characteristics and various seed vigor using 4 sorghum varieties, Nampungchal, Donganme, Hwanggeumchal and Whinchal. No difference was shown in morphological characteristics of the varieties except that the width. Whinchal has bulb-shaped seed, while the other varieties have oval-shaped seeds. The seed coat color of Whinchal is obviously different from those of the other varieties; especially, Nampungchal and Hwanggeumchal are not glossy. Germination rate were Hwanggeumchal > Nampungchal > Donganme > Whinchal in the order of higher rate in standard germination tests and cold germination test. In the ageing test, Donganme showed the lowest 15% decrease in comparison with the standard cultivar. Electric conductivity (EC) has negative correlation with standard germination tests, cold germination test and accelerated ageing test. In the percentage of emergence (PE), Hwanggeumchal was the highest 85.7% which was more than 40% to the lowest Whinchal. Mean emergence time (MET) showed significant difference between the varieties; Whinchal showed the slowest 6.0 days.

• Journal of KIISE:Databases
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• v.31 no.6
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• pp.609-623
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• 2004

Various metadata registries have been built in many countries of the world. Although the metadata registry is an international standard, it does not provide a consistent access interface for handling the metadata registries. Therefore, all systems for managing them were developed by using different operations and access interfaces. It requires duplicate efforts on the same operations whenever metadata registry systems are developed. As a result, it causes unnecessary costs and efforts for building metadata registries, and also incurs inconsistency between the metadata registries because the previous developed systems use the different interfaces for the metadata registry elements This paper analyzes and defines operation patterns that are commonly used for the metadata registries. We defined and designed SQL/MDR extended from SQL using the analyzed operation patterns. SQL/MDR provides a standardized access interface for developing metadata registry systems. This paper shows the implementation of SQL/MDR and the result that we actually applied it to the bibliographical databases. By developing the metadata registry systems using SQL/MDR, we can reduce much time and efforts owing to its standard interface. It allows metadata registries to be accessed consistently. Additionally, it makes all metadata registries follow the international standard, ISO/IEC ll179.

• Journal of Soil and Groundwater Environment
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• v.12 no.3
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• pp.75-80
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• 2007

This study evaluated groundwater quality around an uncontrolled landfill in W sity, Korea, which was monitored for about two years (2005-2006). Parameters of concern include redox-sensitive indicators such as pH, DO, EC, ORP, DOC (dissolved organic carbon), NH3, NO3 and SO4. About 10 years have elapsed after closing dumping of municipal wastes in the landfill. Leachates showed widely varying concentrations in COD(136${\sim}$263 mg/L), T-N(121${\sim}$186 mg/L), and NH3-N(14${\sim}$369 mg/L). Groundwater at the immediate downgradient of the landfill showed weakly acidic pH condition but very high levels of EC (3,000-4,000 ${\mu}S/cm$), which indicated that the groundwater was largely affected by the landfill leachate. Cl, a conservative ion, showed over 200 mg/L at the landfill border, but a gradually decreasing level with distance from the landfill, representing dispersion and dilution (natural attenuation) due to mixing with surrounding groundwater and replenished rainwater. Redox potential showed negative value at the landfill border but it increased up to 350 mV at downgradient wells, which indicated conversion of redox condition from reducing oxic ones. Ammonia, was largely enriched at most of the monitoring wells and its level greatly exceeded drinking water standard. In summary, all the parameters evidenced occurrence of natural attenuation with distance and with time but further monitoring is still required.