• Proceedings of the KAIS Fall Conference
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• 2007.11a
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• pp.350-352
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• 2007

이산화탄소 분리공정용 흡착제 성능을 향상시키기 위하여 이산화탄소에 대한 우수한 선택성을 나타내고는 아민을 결합시키므로 흡착능을 연구하기 위하여 기존의 상용 흡착제에 담지 하므로써 흡착 및 탈착 성능을 비교, 분석하고자 최적의 아민 담지법, 담지체를 연구하였다.

• Proceedings of the KAIS Fall Conference
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• 2003.06a
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• pp.340-342
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• 2003

본 연구의 목표는 난연화를 위한 기존 공법의 단점 보완과 환경 친화적인 난연제를 사용한 비 난연 XLPE 케이블의 난연화 방법과 최적의 난연 코팅액 배합에 있다. 전력용, 통신용 등과 같이 고난연성이 요구되는 경우 기존 컴파운드 방법으로는 난연제를 다량으로 첨가하여 사용하며, base polymer와의 혼합성, 기계적인 물성에도 영향을 끼쳐서는 안되는 등 여러 가지 요구 조건을 만족시켜야 하는 문제점을 가지고 있다. 각 난연 코팅액에 따른 코팅 표면을 고찰한 결과 모든 코팅의 표면은 깨끗하였으며, 코팅층의 두께는 약 10～20 ㎛로 일정하게 코팅이 되었다. Mg(OH)₂/Zinc Borate의 경우는 무게비(wt％)가 1 : 0.5, 1: 0.6에서 난연 효과를 보였으나. 1 : 0.7이상에서는 유연성이 떨어져 코팅층의 균일이 발생하여 연소 테스트시 난연 효과가 떨어지는 현상을 볼 수 있었다. Mg(OH)₂/AF100 S/Zinc Borate의 경우는 AF100 S의 첨가량이 증가할수록 탄화막 형성되어 난연성이 향상되었다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.4
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• pp.2029-2035
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• 2014

In this study, we conducted the adsorption equilibrium and batch experiments of dissolved organic carbon (DOC) in the wastewater by granular activated carbon (GAC). The components of organic compound were Beef extract (1.8 mg/L), Peptone (2.7 mg/L), Humic acid (4.2 mg/L), Tannic acid (4.2 mg/L), Sodium lignin sulfonate (2.4 mg/L), Sodium lauryle sulfate (0.94 mg/L), Arabic gum powder (4.7 mg/L), Arabic acid (polysaccharide) (5.0 mg/L), $(NH_4)_2SO_4$ (7.1 mg/L), $K_2HPO_4$ (7.0 mg/L), $NH_4HCO_3$ (19.8 mg/L), $MgSO_4{\cdot}7H_2O$ (0.71 mg/L), The adsorption characteristics of DOC in synthetic wastewater was described using the mathematical model through a series of isotherm and batch experiments. It showed that there was linear adsorption region in the low DOC concentration (0~2.5 mg/L) and favorable adsorption region in high concentration (2.5~6 mg/L). The synthetic wastewater used was prepared using known quantities of organic and/or inorganic compounds. Adsorption modelling isotherms were predicted by the Freundlich, Langmuir, Sips and hybrid isotherm equations. Especially, hybrid isotherm of Linear and Sips equation was a good adsorption equilibrium in the region of the both the low concentration and high concentration. In applying carbon adsorption for treating water and wastewater, hybrid adsorption equation plus linear equation with Sips equation will be a good new adsorption equilibrium model. Linear driving force approximation (LDFA) kinetic equation with Hybrid (linear+Sips) adsorption isotherm model was successfully applied to predict the adsorption kinetics data in various GAC adsorbent amounts.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.5
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• pp.647-655
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• 2021

The IMO (International Maritime Organization) is discussing the improvement of energy ef iciency of ships in order to reduce greenhouse gas emissions from ships. Currently, by applying an ORC power generation system using waste heat generated from ships, high energy conversion efficiency can be expected from ships. This technology uses an organic medium based on Freon or hydrocarbons as the working fluid, which evaporates at a lower temperature range than water. Through this, it is possible to generate steam (gas) and generate power at a low and low temperature relatively. In this study, the analysis of heat flow between the refrigerant and waste heat in the ORC power generation system, which is an organic Rankine cycle, is analyzed using 3D simulation techniques to determine the temperature change, velocity change, pressure change, and mass change of the fluid flowing of the WHRU (Waste Heat Recovery Unit) inside and the outside the structure. The purpose of this study is to analyze how the mass change affects the structure, and this study analyzed the heat transfer of the heat exchanger from the refrigerant and the exhaust gas of the ship's main engine in the ORC power generation system using this technique.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.12
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• pp.8665-8672
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• 2015

In this study, to investigate the feasibility of malodorous substance and organic matter removal by digest sludge in sewage treatment plants, ammonia, methyl mercaptan(MMC), and hydrogen sulfide($H_2S$) in a reactor submerged with BIO-CLOD(BIO-CLOD) and a reactor not submerged with BIO-CLOD(Non BIO-CLOD) were measured at 24 hours, 48 hours, and 72 hours after the submergence of BIO-CLOD. Whereas the reactor in which BIO-CLOD was submerged showed an ammonia removal rate of 48% and high $H_2S$ and MMC removal rates exceeding 98% in 24 hours, the reactor in which BIO-CLOD was not submerged showed an ammonia removal rate of 45%, an $H_2S$ removal rate of 71%, and an MMC removal rate of 84% in 24 hours indicating the possibility of removal of malodor using BIO-CLOD. A nitrification was shown in which ammonia concentrations decreased over time while nitrate nitrogen concentrations increased and sulfur based malodor components were oxidation decomposed indicating that BIO-CLOD had effects to increase sulfate concentrations in the solution and that sulfate concentration increases and atmospheric $H_2S$ removal rates were correlated with each other. With regard to decreases in organic matter in reactor effluents, BIO-CLOD did not affect in a short period of time and when reactors were operated with HRT 12 hours and HRT 24 hours, HRT 12 hours was considered desirable in terms of economy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.367-373
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• 2016

This study was performed to set a limitation rule to the UV sterilization process for green vegetable juice containing barley sprouts. The main constituents of the green vegetable juice, viz. barley sprouts, organic Angelica keiskei, carrots, organic dandelion, kale, wild parsley, Angelica keiskei and cabbage, were provided by the CSJ company located in Jincheon, Chungbuk, from December 1st, 2015 to March 1st, 2016. Our manufacturing process followed the general manufacturing process of a general green vegetable juice manufacturer. Table 1 shows the mixing ratio for the green vegetable juice. This green vegetable juice includes 18% vegetable sprouts, 3% barley sprouts, 18% angelica utilis makino, 1% orange concentrate, 4% apple concentrate, 6% fructooligosaccharide, 10% vegetable fermentation juice, 0.4% lemon concentrate and 39.6% purified water. We conducted UV sterilization at levels 10, 8 and 5 with powers of 230W, 320W and 320W, respectively. The UV sterilization was conducted twice at 25Hz and then once at 40Hz. In the bacterial tests after sterilization, the number of bacteria in the dandelions decreased from $2.56{\times}10^8CFU/mL$ to $5.96{\times}10^3CFU/mL$. In addition, no food poisoning or coliform bacteria were detected. Thus, this study provides the information required for setting a limitation rule using bacteria tests in the UV sterilization process for green vegetable juice.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5728-5735
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• 2015

This study attempts to verify the applicability of ceramic membrane as a separator by comparing the power generation characteristics in single-chamber MFCs using ceramic membranes to those in the MFCs using nafion membrane. The generated power in MFCs by using acetate as a substrate was more stable than that by using formate, propionate and butyrate, respectively. It was shown that the generated power by using formate substrate in MFCs was unstable and a little higher than that by using acetate, and the power generated by using propionate and butyrate were lower than that by using acetate. In order to find out the Pt catalyst effect, it was compared the power generated in MFCs using Pt-coated carbon cloth as electrode to that power using normal carbon cloth. The power generated in MFCs using Pt-coated carbon cloth as electrode was 1.2 times higher than that using normal carbon cloth. The Pt-coated carbon cloth was about 5 times more expensive than normal carbon cloth. It is suggested that both power generation efficiency and cost together should be considered in selecting electrodes of MFCs. It was found that the ceramic membrane was superior to nafion membrane by comparing to the power generation characteristics obtained. It was shown that average voltage values were $523.67mV{\pm}49.41mV$ by using synthetic wastewater, in MFCs of ceramic membrane as a separator. While average voltage values were $424.09mV{\pm}79.95mV$ by using synthetic wastewater, in MFCs of nafion membrane as a separator. The organic removal efficiency, 41.7% by using ceramic membrane was a little bit higher than 40.8% by using nafion membrane. This research implies ceramic membrane can be a valid alternative to nafion membrane as a separator when considering the power generation and the efficiency of organics removal.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.245-252
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• 2016

This study investigated the environmental conditions and planktonic organisms in the ballast waters (BW) of 22 vessels originating from the international ports of Japan for the purpose of negotiating exemptions from the Ballast Water Management Convention (BWM Convention). The shortest duration of the BW was $3.33{\pm}1.87days$ in area "A", which included Kyushu and Suo Nada at Seto Inland. The total suspended solids, dissolved organic carbon, and particulate organic carbon ranged from 4.60 to 60.9 mg L-1, from 0.97 to 2.69 mg L-1, and from 0.24 to 4.51 mg L-1, respectively. A low average concentration of nutrients was measured in the BW from area "A", but that in the BW from area "C" (around central Honshu) was high, which may be related to the ballasting periods. High chlorophyll-a concentrations (>$1{\mu}g\;L-1$) were measured in four vessels, three of which carried the BW in area "A". High abundances of phytoplankton (> 50,000 cells L-1) were measured in four vessels, three of which carried the BW in area "A". The two vessels originating from Tokyuyama Bay in area "A" showed high densities of dinoflagellates, which are known to be harmful algae. Our results suggest that the negotiations for an exemption from the BWM Convention for Japan should proceed with caution.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.1-6
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• 2019

Organic dye-doped silica nanoparticles are used as a promising nanomaterials for bio-labeling, bio-imaging and bio-sensing. Fluorescent silica nanoparticles(NPs) have been synthesized by the modified $St{\ddot{o}}ber$ method. In this study, dye-free fluorescent silica NPs of various sized were synthesized by Sol-Gel process as the modified $St{\ddot{o}}ber$ method. The functional material of APTES((3-aminopropyl)triethoxysilane) was added as an additive during the Sol-Gel process. The as-synthesized silica NPs were calcined at $400^{\circ}C$ for 2 hours. The surface morphology and particle size of the as-synthesized silica NPs were characterized by field-emission scanning electron microscopy. The fluorescent characteristics of the as-synthesized silica NPs was confirmed by UV lamp irradiation of 365 nm wavelength. The photoluminescence (PL) of the as-synthesized silica NPs with different size was analyzed by fluorometry. As the results, the as-synthesized silica NPs exhibits same blue fluorescent characteristics for different NPs size. Especially, as increased of the silica NPs size, the intensity of PL was decreased. The blue fluorescence of dye-free silica NPs was attributed to linkage of $NH_2$ groups of the APTES layer and oxygen-related defects in the silica matrix skeleton.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.5
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• pp.509-516
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• 2021

This study investigated the effect of dietary supplementation with cysteamine hydrochloride (CSH) on the growth performance and nutrient digestibility of broilers. A total of 180 one-day-old male Ross broilers were allotted to one of the three treatment groups with three replications (20 birds per replication). The experimental groups were as follows: control group (basal diet), CSH-1 group (basal diet + 250 mg CSH/kg feed), and CSH-2 group (basal diet + 500 mg CSH/kg feed). During the grower period, feed intake, body weight, average daily gain, feed conversion ratio (FCR), and livability did not show any variation among the treatment groups. On the other hand, a comprehensive evaluation of the finisher period and the entire experiment period found that FCR was significantly improved in CSH-1 and CSH-2 groups as compared to the control group (p<0.05). The dietary supplementation of CSH did not affect the carcass and meat percent (breast and leg muscle). Although there was no significant difference, the digestibility of organic matter tended to be higher in the CSH-2 group than in the control group (p<0.1). This study suggests that a dietary supplement with 250-500 mg/kg CSH can be effective in improving FCR and the digestibility of organic matter in broilers.