• Journal of Conservation Science
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• v.36 no.6
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• pp.505-510
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• 2020

In this study, the anti-stain effect of the Traditional Myoung-oil, which has been reproduced through traditional method, the Clean Myoung-oil, which was developed in an eco-friendly method through scientific analysis of Traditional Myoung-oil, and the perilla oil, which is the raw material of Myoung-oil and is currently used as a finishing agent when repairing wooden cultural properties was evaluated. As a result of the evaluation, perilla oil showed almost no anti-stain effect, whereas both types of Myoung-oil showed high anti-stain effect. However, it was confirmed that the anti-stain effect was significantly reduced after 4 weeks of exposure to the strain when Myoung-oil was diluted with terpene oil, a natural solvent. Thus, it was considered that the amount of treatment in the wood affected the anti-stain effect of Myoung-oil. In other words, in constructing wooden buildings, Myoung-o il is more suitable as a finishing agent to suppress mold growth than perilla oil. And, in order to increase the applicability of Myoung-oil, it is suggested that additional research on the optimal treatment amount and treatment method that can inhibit mold growth inhibition in outdoor environments is necessary.

• Economic and Environmental Geology
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• v.55 no.4
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• pp.399-406
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• 2022

In line with the megatrend of 2050 carbon neutrality, the amount of critical minerals used in clean-energy technology is expected to increase fourfold and sixfold, respectively, according to the Paris Agreement-based scenario as well as the 2050 carbon-neutrality scenario. And, in the case of Korea, in terms of the battery supply chain used for secondary batteries, the midstream that manufactures battery materials and battery cell packs shows strength, but the upstream that provides and processes raw materials is experiencing difficulties. The Korea Institute of Geoscience and Mineral Resources has established a strategy to secure lithium, nickel, and cobalt and is conducting surveys to respond to the upstream risk of these types of battery raw materials. In the case of lithium, exploration has been carried out in Uljin, Gyeongsangbuk-do since 2020, and by the end of 2021, the survey area was selected for precision exploration by synthesizing all exploration data and building a 3D model. Potential resources will be assessed in 2022. In the case of nickel, the prospective site will be selected by the end of 2022 through a preliminary survey targeting 10 nickel sulfide deposits that have been prospected in the past. In the case of cobalt, Boguk cobalt is known only in South Korea, but there is only a record that cobalt was produced as a minor constituent of hydrothermal deposit. According to the literature, a cobalt ore body was found in the contact area between serpentinite and granite, and a protocol for cobalt exploration in Korea will be established.

• Asia-pacific Journal of Multimedia Services Convergent with Art, Humanities, and Sociology
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• v.8 no.7
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• pp.485-496
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• 2018

In this paper, the smoke behavior in an underground station on operation of the fans in the ventiliation of the station was measured by the experimental method when the fire occurred in the underground station platform where the platfrom screen door was installed. The ventilation characteristics were compared when the ventilation system was operated and when the ventilation system was not operated when a fire occurred at the platform where the clean door was closed. To simulate the fire smoke, the smoke generated from the smoke generator was heated using a hot air fan. The transmittance was measured using a smoke density meter to quantitatively measure fire smoke. If the screen door is closed and the ventilation system of the underground station does not work, it is confirmed that if a fire occurs in the platform, smoke accumulates inside the platform, evacuating passengers is very difficult and can lead to a very dangerous situation. On the other hand, under the condition that the ventilation facility of the subway station is operated, the smoke evacuates to the outside through the ventilation facility of the underground station, and airflow is formed in the direction from the waiting room to the waiting area, so that the passenger located on the platform can safely evacuate toward the concourse. In the following paper, we will discuss the concurrent effect of tunnel ventilation through tunnel vent near the platform.

• Journal of Ocean Engineering and Technology
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• v.37 no.2
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• pp.58-67
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• 2023

While extensive research is being conducted to reduce greenhouse gases in industrial fields, the International Maritime Organization (IMO) has implemented regulations to actively reduce CO₂ emissions from ships, such as energy efficiency design index (EEDI), energy efficiency existing ship index (EEXI), energy efficiency operational indicator (EEOI), and carbon intensity indicator (CII). These regulations play an important role for the design and operation of ships. However, the calculation of the index and indicator might be complex depending on the types and size of the ship. Here, to calculate the EEDI of two target vessels, first, the ships were set as Deadweight (DWT) 50K container and 300K very large crude-oil carrier (VLCC) considering the type and size of those ships along with the engine types and power. Equations and parameters from the marine pollution treaty (MARPOL) Annex VI, IMO marine environment protection committee (MEPC) resolution were used to estimate the EEDI and their changes. Technical measures were subsequently applied to satisfy the IMO regulations, such as reducing speed, energy saving devices (ESD), and onboard CO₂ capture system. Process simulation model using Aspen Plus v10 was developed for the onboard CO₂ capture system. The obtained results suggested that the fuel change from Marine diesel oil (MDO) to liquefied natural gas (LNG) was the most effective way to reduce EEDI, considering the limited supply of the alternative clean fuels. Decreasing ship speed was the next effective option to meet the regulation until Phase 4. In case of container, the attained EEDI while converting fuel from Diesel oil (DO) to LNG was reduced by 27.35%. With speed reduction, the EEDI was improved by 21.76% of the EEDI based on DO. Pertaining to VLCC, 27.31% and 22.10% improvements were observed, which were comparable to those for the container. However, for both vessels, additional measure is required to meet Phase 5, demanding the reduction of 70%. Therefore, onboard CO₂ capture system was designed for both KCS (Korea Research Institute of Ships & Ocean Engineering (KRISO) container ship) and KVLCC2 (KRISO VLCC) to meet the Phase 5 standard in the process simulation. The absorber column was designed with a diameter of 1.2-3.5 m and height of 11.3 m. The stripper column was 0.6-1.5 m in diameter and 8.8-9.6 m in height. The obtained results suggested that a combination of ESD, speed reduction, and fuel change was effective for reducing the EEDI; and onboard CO₂ capture system may be required for Phase 5.

• Analytical Science and Technology
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• v.19 no.5
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• pp.415-421
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• 2006

The following concentrations of some PAHs were investigated; [benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h)anthracene, benzo(g,h,i)perylene, indeno (1,2,3-c,d)pyrene] in vegetables(n=160) and fruits(n=50). The food samples were purchased at the local markets in Seoul, Chuncheon, Daejeon, Kwangju and Pusan. The samples were radish, onion, bean sprouts, welsh onion, chinese cabbage, spinach, young pumpkin, garlic, cucumber, carrot, lettuce, sesame leaf, tangerine, persimmon, apple, pear and banana. The methodology involved ultrasonic extraction with dichloromethane, clean-up on Sep-Pak florisil cartridges and determination by HPLC/FLD (High Performance Liquid Chromatography/Fluorescence Detector). Overall method recoveries for 8 PAHs spiked into these products ranged from 95 to 102%. The mean level of the following PAHs were determined; benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h)anthracene, benzo(g,h,i)perylene and indeno(1,2,3-c,d)pyrene in vegetables and fruits was N.D., 0.014 ng/g, 0.031 ng/g, 0.016 ng/g, 0.019 ng/g, 0.091 ng/g, 0.016 ng/g and N.D., respectively.

• Analytical Science and Technology
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• v.19 no.5
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• pp.441-448
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• 2006

11-nor-9-carboxy-${\Delta}^9$-tetrahydrocannabinol (THCCOOH) is the major metabolite of tetrahydrocannabinol (THC) which is the primary psychoactive component of marijuana. It is also the target analyte for the discrimination marijuana use. A method using solid-phase extraction (SPE) and gas chromatography/mass spectrometry (GC/MS) was developed for the determination of THCCOOH in human urine. Urine samples (3 mL) were extracted by SPE column with a cation exchange cartridge after basic hydrolysis. The eluents were then evaporated, derivatized, and injected into the GC/MS. The limits of detection (LOD) and quantitation (LOQ) were 0.4 and 1.2 ng/mL, respectively. The response was linear with a correlation coefficient of 0.999 within the concentration range of 1.2 (LLE 1.3)~50.0 ng/mL. The precision and accuracy were stable within 1.20% and the recovery was 83.6~90.7%. The recovery of SPE method was lower than that of liquid-liquid extraction (LLE), but there were no apparent differences in LOD, LOQ, precision and accuracy between the two methods. While SPE method is used as a very effective and rapid procedure for sample pretreatment, and clean extracts, LLE method was not suitable for the extraction procedure of THCCOOH in urine. The applicability of the method was proven by analyzing a urine samples from a marijuana abusers.

• Analytical Science and Technology
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• v.22 no.1
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• pp.109-117
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• 2009

The following concentrations of some PAHs were investigated; [benzo(a)anthracene, chrysene, benzo (b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(a,h)anthracene, benzo(g, h, i)perylene, indeno (1,2,3-c,d)pyrene] in fish(n=168) and shellfish(n=40). The methodology involved saponification and extraction with n-hexane, clean-up on Sep-Pak Florisil Cartridges and determination by HPLC/FLD (High Performance Liquid Chromatograph/Fluorescence Detector). Overall method recoveries for 8 PAHs spiked into these products ranged from 88 to 112%. The mean level of benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k) fluoranthene, benzo(a)pyrene, dibenzo(a,h)anthracene, benzo(g,h,i)perylene and indeno(1,2,3-c,d)pyrene in cooked fish was ND, ND, 0.0009, ND, 0.01, ND, ND, ND and in cooked shellfish was 1.84, 3.51, 0.81, 0.38, 0.39, 0.04, 0.20, ND, respectively.

• Analytical Science and Technology
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• v.21 no.3
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• pp.191-200
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• 2008

Pharmaceuticals and personal care products (PPCPs) are emerging contaminants in aquatic environmental samples. Therefore, it required rapidly and certainly analytical method for pharmaceuticals which are existed in environment. In this study, Liquid chromatography/tandem mass spectrometry (LC-MS/MS) with electrospray ionization (ESI) was used to measure the concentrations of 7 pharmaceuticals (quinoxaline-2-carboxylic acid, acetylsalicylic acid, diclofenac-Na, naproxen, ibuprofen, mefenamic acid, talniflumate) from environmental water or aquatic samples simultaneously. Effective sample clean-up by solid-phase extraction (SPE) prior to LC-MS/MS analysis is necessary. For further purification, Mixed Cation eXchange (MCX) and Hydrophilic-Lipophilic Balance (HLB) solid-phase extraction (SPE) cartridges were used to eliminate the remaining interferences. LODs (Limits of Detection) and MDLs (Method Detection Limits) for the spiked sample in fresh water were in the range of 0.05~1.50 pg/mL and 0.17~4.90 pg/mL, respectively. The absolute recovery in the concentration of 1.0 ng/mL were between 81.9 and 116.3%. The acidic pharmaceuticals were detected in concentrations of 0.018~16.925 ng/mL in aquatic environmental samples.

• Journal of the Korea Organic Resources Recycling Association
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• v.17 no.1
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• pp.80-87
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• 2009

This research was conducted to evaluate pyrolysis characteristics of the sludge discharged from paper mill process with sintering temperature. The sludge was composed of 70.72% of moisture, 9.52% of volatile solids, and 19.76% of ash, respectively. The sludge contained high 66.40% of $Fe_2O_3$ and CaO(15.80%), $Al_2O_3$(9.42%), and $SO_3$(3.75%) components, and minor $SiO_2$, $Na_2O$, and $Cr_2O_3$ were also contained in it. The other components except $Fe_2O_3$ and $Cr_2O_3$ were slightly decreased with increase of sintering temperature. Specific surface area of the sludge before sintering was $130m^2/g$ and ones after sintering at $400^{\circ}C$ and $700^{\circ}C$ were $114m^2/g$ and $33m^2/g$ respectively. Specific surface area of sludge was decreased with increase of sintering temperature. From the result of TG-DTA, it was shown that weight of the sludge was decreased by moisture and organic loss until $600^{\circ}C$ and decreased by volatilization of metal components and additional combustion of carbon until $800^{\circ}C$.

• Korean Chemical Engineering Research
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• v.52 no.5
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• pp.657-666
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• 2014

Coal gasification technology is considered as next generation clean coal technology even though it uses coal as fuel which releases huge amount of greenhouse gas because it has many advantages for carbon capture. Coal or pet-coke slurry gasification is very attractive technology at present and in the future because of its low construction cost and flexibility of slurry feeding system in spite of lower efficiency compared to dry feeding technology. In this study, we carried out gasification experiment using bituminous coal slurry sample by integrating coal slurry feeding facility and slurry burner into existing dry feeding compact gasifier. Especially, our experiment was conducted under fairly lower operation temperature than that of existing entrained-bed gasifier, resulting in partial slagging operation mode in which only part of ash was converted to slag and the rest of ash was released as fly ash. Carbon conversion rate was calculated from data analysis of collected slag and ash, and then cold gas efficiency, which is the most important indicator of gasifier performance, was estimated by carbon mass balance method. Fairly high performance considering pilot-scale experiment, 98.5% of carbon conversion and 60.4% of cold gas efficiency, was achieved. In addition, soundness of experimental result was verified from the comparison with chemical equilibrium composition and energy balance calculations.