• Membrane Journal
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• v.20 no.2
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• pp.97-105
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• 2010

This study was to evaluate the performance of the Double stage Pore controllable fiber (DP) filter system as the pre-treatment of the RO membrane. The evaluation for the pre-treatment filter was performed through the indirect method, SDI (Silt Density Index) measurement of the filtrate. This study was done during Jan. 3 of 2009 to Dec. 3 of 2009 at OO Water Treatment Plant that was suppling industrial water to plants, and the raw water was contaminated lake water and it was fed to the system after clarification with coagulation. The average turbidity of the feed water and that of the filtrate was 0.79 NTU (0.28~4.01 NTU), and 0.16 NTU (0.04~0.50) respectively. And so the average turbidity removal efficiency was 77%. The filtrate flow rate and the backwash water flow rate was about 230 $m^3$/day and about 8.7 $m^3$/day respectively, and so the backwash rate was 3.8%. The data for some samples were obtained after a few days storage, and it caused the higher turbidity and SDI15 as the storage time was increased. But average SDI value of the filtrate was 3.6 (2.26~5.00) which was lower than minimum value required by the RO membrane manufacturer as the RO feed water to guarantee the life time of the RO membrane. So, the DP filter system was enough for the application as the pre-treatment of the RO membrane.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.641-644
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• 2008

This paper investigated the plant and raw material of the ready-mixed concrete company which could supply to the second Lotte World on Pusan. the results were summarized as following. Almost plants were mainly using Twin shaft mixer which was 210m$^3$/hr and horizontal type. There was different the number of admixture silos at each plants, and they were separated by types. The mixtures mainly consisted of the ordinary portland cement, fly ash and blast furnace slag. For favorable quality control, each materials had to carry from same factories, and the monitering standard for quality control should be prepared. The coarse aggregates were used with many different producing districts, so they were only used from Y caused by exclusion of quality difference. The crushed, washed and river sands were generally used as fine aggregates, so the fine aggregates which could be possible to supply stable quality were chosen. This study used Poly Carbonic Acid Admixture which was developed to satisfy maintenance of performance till 2 hours and 10MPa at 15 hours.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.10
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• pp.1356-1362
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• 2012

UV-VIS spectrophotometric and high-performance liquid chromatographic (HPLC-DAD) methods were applied in order to identify and quantify the composition of polyphenols in commercial cocoa-containing products. Total polyphenolic contents of cocoa mix, choco-syrup, milk chocolate, and dark chocolate were evaluated using Folin-Ciocalteu's phenol reagent according to a UV-VIS spectrometric method. Antioxidant capacities of cocoa extracts by methanol were evaluated by 2,2'-azino-bis(3-ethyl benzothiazoline-6-sulfonic acid) (ABTS) assay and 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. The obtained results show that the polyphenolic contents and antioxidant capacities of cocoa products and chocolates depend on solid cocoa content. Among the tested cocoa products and chocolates, the most abundant phenolic compound was epicatechin.

• Preventive Nutrition and Food Science
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• v.14 no.3
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• pp.240-245
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• 2009

High-performance liquid chromatography (HPLC) was applied to determine the carotenoid composition of carrots during storage and cooking. Analyses were conducted immediately after harvest and 1, 2, 4, and 8 weeks after harvest. During the course of the storage, the carotenoid levels generally decreased, and this decrease was found to be greater during the first week for $\beta$-carotene (all-trans-$\beta$-carotene) and lutein, and during the second week for $\alpha$-carotene. Additionally, the amount of the $\alpha-$ and $\beta$-carotenes in carrot leaves changed slightly within the first 2 weeks of harvest when stored at $4^{\circ}C$. Specifically, the level of lutein, the main component of carrot leaves, increased from 233.8$\pm$11.7 to $346.2\pm26.7{\mu}g$/g DW during the first 2 weeks. In addition, the change in carotenoid contents was observed during the home-processing of one Korean cultivar. Carrots fried in oil showed the highest amount of $\beta$-carotene ($164.3\pm6.6{\mu}g$/g DW) and $\alpha$-carotene ($50.1\pm0.4{\mu}g$/g DW), while carrots that were prepared by sauteing, pressure-cooking in water and microwaving had the second highest levels. The greatest loss of in carotenoids occurred in response to boiling in water containing 1% NaCl, braising and baking. The content of lutein increased slightly after boiling in water containing 1% NaCl ($9.3\pm0.4{\mu}g$/g DW), while a loss in lutein occurred after preparation using other home-processing methods. A cis-isomer of all-trans-$\beta$-carotene, 13-cis-$\beta$-carotene, was present in detectable amounts in all processed samples, but not in raw roots. Another isomer, 9-cis-$\beta$-carotene, was detected in carrots that were prepared by boiling, frying and pressure-cooking.

• Journal of the Korean Institute of Intelligent Systems
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• v.26 no.3
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• pp.246-252
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• 2016

Since thermal power plant (TPP) equipment is operated under very high pressure and temperature, failures of the equipment give rise to severe losses of life and property. To prevent the losses, fault detection method is, therefore, absolutely necessary to identify abnormal operating conditions of the equipment in advance. In this paper, we present Mahalanobis distance (MD) based fault detection method for steam boiler tube in TPP. In the MD-based method, it is supposed that abnormal data samples are far away from normal samples. Using multivariate samples collected from normal target system, mean vector and covariance matrix are calculated and threshold value of MD is decided. In a test phase, after calculating the MDs between the mean vector and test samples, alarm signals occur if the MDs exceed the predefined threshold. To demonstrate the performance, a failure case due to boiler tube leakage in 200MW TPP is employed. The experimental results show that the presented method can perform early detection of boiler tube leakage successfully.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.40 no.5
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• pp.437-447
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• 2016

In a nuclear power plant, the fuel assembly, which is composed of fuel rods, burns, and the high temperature can generate power. The fuel rod consists of pellets and a cladding that covers the pellets. It is important to understand the pellet-cladding mechanical interaction with regard to nuclear safety. This paper proposes simulation of the PCMI. The gap between the pellets and the cladding, and the contact pressure are very important for conducting thermal analysis. Since the gap conductance is not known, it has to be determined by a suitable method. This paper suggests a solution. In this study, finite element (FE) contact analysis is conducted considering thermal expansion of the pellets. As the contact causes plastic deformation, this aspect is considered in the analysis. A 3D FE module is developed to analyze the PCMI using FORTRAN 90. The plastic deformation due to the contact between the pellets and the cladding is the major physical phenomenon. The simple analytical solution of a cylinder is proposed and compared with the fuel rod performance code results.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.13 no.2
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• pp.67-73
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• 2007

A respiration rate analysed by enzyme kinetics-based respiration model and gas permeability data of LDPE film were applied to design the optical modified atmosphere (MA) packaging condition of persimmon (Diospyros kaki cv. Fuyu) fruits. The fruit quality rapidly decreases due to physiology disorder such as softening and peel blackening. $O_2$ permeance ($Q_{O2}$ in $ml{\cdot}hr^{-1}{\cdot}atm^{-1}{\cdot}m^{-2}$) and $CO_2$ performance ($Q_{CO2}$ in $ml{\cdot}hr^{-1}{\cdot}atm^{-1}{\cdot}m^{-2}$) of low density polyethylene (LDPE) film samples were measured at $0^{\circ}C$ and described as function of thickness (L in ${\mu}m$) as $Q_{O2}=(2540{\times}1/L)-16$, and $Q_{CO2}=(13742{\times}1/L)-70$, respectively. MA package containing single persimmon fruit of 225g was designed and tested experimentally at $0^{\circ}C$ by using LDPE films. Package atmospheres predicted from the relationship of $O_2$, $CO_2$ and $N_2$ balances on the packages was in good agreement with those obtained experimentally. Physiology disorder occurrence was the lowest at 52 ${\mu}m$ package that attained optimum gas condition ($O_2$ 2.8% and $CO_2$ 5.4%). The computer simulation was found to be effective to help to design the optimum MA packaging condition of individual persimmon fruit.

• Asian Journal of Turfgrass Science
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• v.25 no.2
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• pp.217-222
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• 2011

Professional turfgrass applicators have reduced or eliminated phosphorus from their fertilization programs based on the assumption that soil phosphorus levels are supplying adequate amounts of phosphorus to the turfgrass. The previous researchers found that there were no P effects for turfgrass growth especially for mature turf. No effects may result from high P level in heavy thatch layer. The research was conducted for one year to investigate the effects of phosphorus fertilization programs on turfgrass performance, and monitor soil and plant tissue nutrient levels to determine the impact of the programs on a newly seeded Kentucky bluegrass. The nitrogen treatments were 20, 30 and $40g\;m^{-2}\;yr^{-1}$. The low, medium, and high nitrogen treatments were applied over 2, 4 and 6 applications, respectively. Nitrogen was applied using a formulation containing 30% of slow and 70% of fast release nitrogen sources that are representative of typical home lawn fertilizers. The phosphorus treatments were 0, 10 and $20g\;m^{-2}\;yr^{-1}$. Phosphorus was applied according to the application schedule for the nitrogen treatments. Kentucky bluegrass was seeded in May, 2010. The thickness of thatch layer was less than 1 cm and the first treatment was applied to Kentucky bluegrass in April, 2011. The low N rate treatment had acceptable color and quality ratings without high clipping yields. The high N rate treatment consistently had the highest color and quality ratings but also had very high clipping yields in comparison to the low and medium N rate treatments. Although there are significant differences in tissue P, Overall, there was no effect of phosphorus on color, quality, or clipping weights.

• Journal of Digital Contents Society
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• v.10 no.4
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• pp.639-648
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• 2009

Earth's environment issues are introduced recently and every year the social loss have been occurred by the impact of various disaster. This kind of disaster and weather problems are the increasing reason of electricity transmission network equipment's failures because of exposing by the natural environment. The emergency and abnormal status of electricity equipment make the power outage of manufacturing plant and discomfort of people's lives. So, to protect the electricity equipment from the natural disasters and to supply the power to customer as stable, the supporting systems are required. In this paper, the research results are described the development process and the outcomes of the real-time natural disaster failure analysis information system including the describing about the impact of disaster and weather change, making the natural weather information, and linking the realtime monitoring system. As of development process, according to application development methodology, techniques are enumerated including the real time interface with related systems, the analysing the geographic information on the digital map using GIS application technology to extract the malfunction equipment potentially and to manage the equipments efficiently. Through this system makes remarkable performance it minimize the failures of the equipments, the increasing the efficiency of the equipment operation, the support of scientific information related on the mid-term enhancement plan, the savings on equipment investment, the quality upgrading of electricity supply, and the various supports in the field.

• Elastomers and Composites
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• v.47 no.1
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• pp.2-8
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• 2012

In this study, in order to develop renewable bio-based nanocomposites, multi-functional nanocomposites from soybean resins (AESO, MAESO) and nanoclay were prepared. Photoelectrodes for environmental friendly dye-sensitized solar cell using soybean resin were also prepared. Organo-modified nanoclay was directly dispersed in functionalized soybean resins after mixing with styrene as a comonomer and radical initiator was used to copolymerize the nanocomposites. The observed morphology was a mixture of intercalated/exfoliated structure and the physical properties were improved by adding nanoclay. A nanocomposite using MAESO, which added COOH functional group to the soybean resin, showed better dispersibility than AESO composites. Ultrasonic treatment of the nanocomposites also improved the physical properties. Nanoporous $TiO_2$ photoelectrode was also prepared using soybean resins as a binder, after acid-treatment of $TiO_2$ surface using nitric acid. Dye-sensitized solar cells were prepared after adsorbing dye molecules on it. The $TiO_2$ photoelectrode prepared using soybean binder had high current density because of increased surface area by improved dispersibility. The photoelectrochemical properties and conversion efficiency of the solar cell were significantly improved using the soybean binder.