Since 2010, the Odor Prevention Act has identified and regulated four types of fatty acids as substances that cause odors. Four types of fatty acids are contributors to odor pollution and are sensitive to changes in temperature and humidity. However, the current analysis method has several limitations, including dependency on the timing of sampling before and after the procedure, as well as dependency on the specific analysis method employed. The aim of this study is to assess the efficacy of the ion chromatography analysis method by utilizing ultrapure distilled water as a means to improve the current approach. Initially, the analysis system underwent a quality assessment. The results indicated a linearity (R2) of 0.99, a limit of 10 nmol/mol or lower, supporting the conclusion that it is suitable. Furthermore, the investigation focused on the substance’s tendency to change over time in ultrapure water and under alkali absorption (0.01N NaOH). At a concentration of 0.95 ng (low-concentration standard sample), the confirmed peak area values ranged from 0.0004 μg/min to 0.0010 μg/min, resulting in an injection variation of approximately ± 0.001. At 23.7 ng (high-concentration standard sample), the peak area value fluctuated between 0.008 μg/min and 0.013 μg/ min, with an average of ± 0.002. Therefore, storing the material at temperatures below 4°C for up to 3 days (72 hours) after manufacturing seemed to facilitate the optimal conditions for maintaining its stability without significant changes taking place. Finally, blank samples from the laboratory, equipment, and site were analyzed. Out of the four substances analyzed, only n-butyl acid was detected in all three background samples. It was confirmed that it represented 4% of the peak area in the 4.94 ng standard sample.

In this study, a THC removal system was developed using an oxidation catalyst to solve the problems of the existing thermal oxidation methods, RTO and RCO. In addition, this system was applied to industrial sites to confirm the VOCs removal efficiency. As a result of testing to remove THC and VOCs by applying the reaction system for THC removal in industrial sites, the THC removal efficiency range is between 99.5% and 99.9%. The treatment efficiency of individual VOCs treated through this system was the lowest at 79.0% for methylethylketone and the highest at 91.3% for acetaldehyde, and the average treatment efficiency was about 85.4%. From these numbers, the performance was superior to the existing RTO and RCO systems that showed THC removal performance. This is due to the fact that the oxidation reaction of the oxidation catalyst is a very fast catalyst surface reaction, and the characteristics of the catalytic oxidation reaction are complete oxidation and oxidation reaction under rarefied conditions. In this study, the catalyst role in the reaction system for THC removal is to process THC simultaneously with the system heat source. This is believed to be because the reaction of the oxidation catalyst is a strongly exothermic reaction and can sufficiently provide the amount of heat necessary for the system. At the same time, an oxidation reaction that breaks the bonds of the THC component also occurs. This reaction is a strong exothermic reaction, which can help the system maintain a high temperature during the reaction, and is considered an effective system for processing high concentrations of THC in actual industrial sites where THC concentrations are high, as in this study.

In this study, AlSi10Mg alloy powders are synthesized using gas atomization and sieving processes for powder bed fusion (PBF) additive manufacturing. The effect of nozzle diameter (ø = 4.0, 4.5, 5.0 and 8.0 mm) on the gas atomization and sieving size on the properties of the prepared powder are investigated. As the nozzle diameter decreases, the size of the manufactured powder decreases, and the uniformity of the particle size distribution improves. Therefore, the ø 4.0 mm nozzle diameter yields powder with superior properties. Spherically shaped powders can be prepared at a scale suitable for the PBF process with a particle size distribution of 10–45 μm. The Hausner ratio value of the powder is measured to be 1.24. In addition, the yield fraction of the powder prepared in this study is 26.6%, which is higher than the previously reported value of 10–15%. These results indicate that the nozzle diameter and the post-sieve process simultaneously influence the shape of the prepared powder as well as the satellite powder on its surface.

The concentrations of volatile organic compounds (VOCs) and odor-inducing substances were measured using selected ion flow tube mass spectrometers (SIFT-MS) and a drone equipped with an air quality monitoring system. SIFT-MS can continuously measure the concentration of VOCs and odor-inducing substances in realtime without any pre-treating steps for the sample. The vehicle with SIFT-MS was used for real-time measurement of VOC concentration at the site boundaries of pollution sources. It is possible to directly analyze VOCs concentration generated at the outlets by capturing air from the pollution sources with a drone. VOCs concentrations of nine spots from Banwol National Industrial Complex were measured by a vehicle equipped with SIFT-MS and were compared with the background concentration measured inside the Metropolitan Air Quality Management Office. In three out of the nine spots, the concentration of toluene, xylene, hydrogen sulfide, and methyl ethyl ketone was shown to be much higher than the background concentration. The VOCs concentrations obtained using drones for high-concentration suspected areas showed similar tendencies as those measured using the vehicle with SIFTMS at the site boundary. We showed that if both the drone and real-time air quality monitoring equipment are used to measure VOCs concentration, it is possible to identify the pollutant sources at the industrial complex quickly and efficiently check sites with high concentrations of VOCs.

We developed a wet scrubber by applying cyclone flow to the gas flow and using a spiral filter structure. While the size of a new scrubber was about half that of a conventional scrubber, the device showed relatively high efficiency in pollutants removal such as particulate matter and compounds inducing odor. The new scrubber installed in a plating industry showed a higher removal efficiency of about 5% for dust, about 23% for hydrogen chloride, and about 23% for sulfur dioxide compared to the conventional scrubber. Plurality of tubes in the spiral filer housing are arranged to be vertically shifted from each other. Because the upward residual gas does not directly rise vertically, the residence time of gas between the filter plates is extended. Thus, the purification efficiency of the pollutants was enhanced in the new scrubber. In addition, the new scrubber developed in this study is more cost effective because the cost saving in manufacturing it compared with a conventional scrubber increases with increasing the size of equipment. It is expected that a scrubber with better dust collecting efficiency can be obtained by carrying out a study in connection with facilities capable of controlling acidity of washing water.

Hyaluronan은 난포액, 나팔관과 자궁에 존재하는 물질로 돼지의 다정자 수정을 억제하고 체외배 양액에 첨가시 배 발육을 향상시키는 것으로 알려져 있다. Glucuronic acid와 N-acetyl-D-glucosamine (GlcNAc)은 이중결합하여 hyaluronan을 구성하는 물질이다. 본 연구에서는 체외성숙 배양액 내 Glucuronic acid 및 GlcNAc 첨가가 돼지 난자의 성숙 및 단위발생 난자의 배 발육에 미치는 영향 을 조사하였다. 난자의 체외성숙 배양액으로는 0.1% PVA (polyvinyl alcohol)가 첨가된 Medium-199 을 기본배양액으로 이용하였고, 여기에 cysteine, pyruvate, epidermal growth factor, kanamycin, insulin 및 호르몬을 추가하여 44시간 동안 난자를 배양하여 체외성숙을 유도하였다. 실험설계에 따라 glucuronic acid 및 GlcNAc를 각각 0, 0.005, 0.01, 0.05, 0.1 mM의 농도로 체외성숙 배양액에 첨가 하였다. 체외성숙된 난자는 전기자극을 통해 단위발생을 유도하였고 porcine zygote medium-3에서 7일간 체외 배양하였다. 실험 결과 난자의 체외성숙 배양액 내 glucuronic acid 첨가는 난자의 핵 성숙률(91.3-94.4%), 단위발생 후 분할률(85.5-93.6%) 및 배반포 발달율(42.0-51.0%)에 영향을 미치지 않았으나 배반포 세포수는 0.05 mM glucuronic acid 첨가 군에서 38.0개로 대조군의 31.5개에 비해 유의적으로(P<0.05) 증가하였다. 난자의 체외 성숙 배양액에 GlcNAc를 첨가하였을 때 난자의 핵 성숙률(94.3-97.2%) 및 단위발생 후 배반포 세포수(40.0-43.1)는 대조군 및 첨가 농도의 차이에 따라 유의적인 차이를 보이지 않았으나 분할률은 0.05 mM 처리군에서 91.8%로 대조군(85.0%) 및 0.005 mM 처리군(84.6%)에 비해 유의적(P<0.05)으로 증가하였다. 또한 0.05 mM 처리군의 배반포 발달 율은 59.6%로 대조군(46.3%), 0.005 mM 처리군(44.3%) 및 0.1 mM 처리군(45.2%)에 비해 유의적으 로 높았다. 이상 결과로 보아 체외성숙 배야액 내 0.05 mM glucuronic acid 및 GlcNAc 첨가는 돼 지 난자의 단위발생 후 배 발육을 증가시키는 것으로 사료된다.

Vanadium dioxide (VO2) is an attractive material for smart window applications where the transmittance of light can be automatically modulated from a transparent state to an opaque state at the critical temperature of ~68˚C. Meanwhile, F : SnO2 (F-doped SnO2, FTO) glass is a transparent conductive oxide material that is widely used in solar-energy-related applications because of its excellent optical and electrical properties. Relatively high transmittance and low emissivity have been obtained for FTO-coated glasses. Tunable transmittance corresponding to ambient temperature and low emissivity can be expected from VO2 films deposited onto FTO glasses. In this study, FTO glasses were applied for the deposition of VO2 thin films by pulsed DC magnetron sputtering. VO2 thin films were also deposited on a Pyrex substrate for comparison. To decrease the phase transition temperature of VO2, tungsten-doped VO2 films were also deposited onto FTO glasses. The visible transmittance of VO2/FTO was higher than that of VO2/pyrex due to the increased crystallinity of the VO2 thin film deposited on FTO and decreased interface reflection. Although the solar transmittance modulation of VO2/FTO was lower than that of VO2/pyrex, room temperature solar transmittance of VO2/FTO was lower than that of VO2/pyrex, which is advantageous for reflecting solar heat energy in summer.