This study evaluated the effects of acidulant treatment on the quality and storage period of Topokkidduck. Two samples of Topokkidduck were prepared, one soaked in 10% acidulant (10SAT) and the other without soaking in the acidulant (NSAT). During the storage period, the two samples were tested for presence of microorganisms (aerobic bacteria, E.coli, and mold) and physicochemical properties (color value, texture profile analysis (TPA)). The 10SAT could be stored for 49 days without detection of E.coli and a mold level of 1.0 log CFU/g. NSAT could be stored for only 21 days. NSAT had an aerobic count of 2.27 log CFU/g as early as 7 days, and E.coli was detected at 21 days at a level of 4.15 log CFU/g. The presence of E.coli is not permitted according to the Ministry of Food and Drug Safety (MFDS). The hardness of the 10SAT increased during the storage period but to a much lesser extent compared to the NSAT. Thus the preparation of Topokkidduck by soaking in the acidulant controlled microbial growth for up to 49 days which is a much longer period compared to the control. Also, Topokkidduck soaked in the acidulant had a softer texture than the control during the storage period.

오존은 수돗물 정수장에서 이용되는 소독 물질로 미세오염 물질들을 비롯해서 박테리아나 병원성 미생물체를 효과적으로 제거하는 것으로 많은 연구가 보고되어 있다. 본 연 구에서는 실내 사육 중인 붉은 체색을 지닌 Glyptotendipes tokunagai를 대상으로 서로 다른 농도의 오존 노출에 따른 영향을 파악하기 위해 치사율, 체색 변화와 heat shock protein 70 (HSP70) 유전자 발현을 측정하였다. 오존에 노출 된 G. tokunagai에서 농도-시간 의존적으로 치사율 증가가 관찰되었다. 또한 체색 변화는 오존 농도에 따라 붉은색의 체색이 체절마다 엷어지며 탈색되고 경직되는 현상이 보였다. HSP70 유전자 발현은 저농도인 0.2~0.5 ppm에서 노출 10분과 20분에 유의한 수준으로 높게 나타났으나 (P<0.05), 30 분 노출 후에는 발현량이 감소하는 경향을 보였다. 생리적으로 저산소층에 대해 적응능력이 뛰어난 깔따구 경우에도 오존은 매우 강력한 치사 효과를 유발하여 30분 노출 후 경직과 헤모글로빈 파괴로 인한 탈색이 유발되는 것을 보여주었다. 따라서 본 결과는 수돗물 정수장에서 병원성 미생물을 제거하는 데 사용되는 오존이 수생물에 주는 영향성을 파악하는 기초자료로서 활용될 수 있을 것이다.

Fungicide spraying and PVC (polyvinyl chloride) wrapping were carried out for the improvement of storage yield in winter kimchi cabbage. Acetic acid, rox, tebuconazole and fludioxonil were sprayed on the cabbage, and then cabbage boxes were wrapped with 0.02 mm polyvinyl chloride film. The weight loss ratio of wrapped cabbages were 8.62% and 15.71% in unwrapped cabbages. Trimming loss ratio was the lowest in the mixed treatment of acetic acid, rox and tebuconazole in wrapped cabbage. Physiological disorders of 90-day stored cabbage was better in wrapped cabbage, especially with the mixed treatment of acetic acid, rox and tebuconazole. Wrapping and fungicide treatment reduced the storage loss ratio and physiological disorder for storage of kimchi cabbages.

This study aimed to investigate the effect of storage temperature and pressure plate treatment on chemical composition in Prunus mume sugar extracts (PSEs). Green Prunus mume fruit was mixed with an equal amount of commercial sugar and stored at 4 or 25oC for 9 mon with or without a pressure plate. The alcohol contents in PSEs stored at 4oC were lower than those stored at 25oC. The amygdalin contents in PSEs stored at 25oC with pressure plate were significantly low. The sucrose in PSEs was converted into glucose and fructose during storage. The glucose, fructose and total phenol contents in PSEs stored at 25oC were higher compared with those at 4oC. The total soluble solid and polyphenol contents in PSEs were increased at 25oC until 90 d and 4oC until 150 d and then the contents were constant. The total acidity in PSEs stored at 4oC were higher than those at 25oC. These results indicate that storage temperature plays an important role in controlling the alcohol, amygdalin and sucrose contents in Prunus mume sugar extracts (PSEs).

This study examined the combined effects of high hydrostatic pressure (HHP) and micro-perforated (MP) film packaging on the microbiological and physicochemical qualities of kimchi sauce stored under fluctuating temperature conditions. Before storage, treatment with 600 MPa HHP reduced the total lactic acid bacteria in the sauce samples to below the detection limit (1 log CFU/g). After 68-day storage, ten microbial strains isolated from the non-treated controls were identified as Pediococcus pentosaceus, whereas eight microbial strains isolated from the HHP-treated samples were identified as Bacillus spp., regardless of the packaging type. Additionally, the samples treated with HHP and packaged in a multilayer film bag (ML-HPP), as well as those in the MP-HHP group, exhibited higher pH values and reduced sugar content than the ML-control or MP-control after 68-day storage. No significant differences were observed between the control and treatment groups regarding their electrical conductivity, salinity, and CIE a* values at the end of storage. However, there was no O2 reduction or CO2 accumulation in the MP-HHP group after 68-day storage. These results indicate that the combination of HHP treatment and MP-film packaging can extend the kimchi sauce's shelf life without packaging expansion during long-term storage.

AZO thin films are grown on a p-Si(111) substrate by RF magnetron sputtering. The characteristics of various thicknesses and heat treatment conditions are investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Hall effect and room-temperature photoluminescence (PL) measurements. The substrate temperature and the RF power during growth are kept constant at 400 ℃ and 200 W, respectively. AZO films are grown with a preferred orientation along the c-axis. As the thickness and the heat treatment temperature increases, the length of the c-axis decreases as Al3+ ions of relatively small ion radius are substituted for Zn2+ ions. At room temperature, the PL spectrum is separated into an NBE emission peak around 3.2 eV and a violet regions peak around 2.95 eV with increasing thickness, and the PL emission peak of 300 nm is red-shifted with increasing annealing temperature. In the XPS measurement, the peak intensity of Al2p and Oll increases with increasing annealing temperature. The AZO thin film of 100 nm thickness shows values of 6.5 × 1019 cm−3 of carrier concentration, 8.4 cm−2/V·s of mobility and 1.2 × 10−2 Ω·cm electrical resistivity. As the thickness of the thin film increases, the carrier concentration and the mobility increase, resulting in the decrease of resistivity. With the carrier concentration, mobility decreases when the heat treatment temperature increases more than 500 ℃.

The enamel powders used traditionally in Korea are produced by a ball-milling process. Because of their irregular shapes, enamel powders exhibit poor flowability. Therefore, polygonal enamel powders are only used for handmade cloisonné crafts. In order to industrialize or automate the process of cloisonné crafts, it is essential to control the size and shape of the powder. In this study, the flowability of the enamel powders was improved using the spheroidization process, which employs the RF plasma treatment. In addition, a simple grid structure and logo were successfully produced using the additive manufacturing process (powder bed fusion), which utilizes spherical enamel powders. The additive manufacturing technology of spherical enamel powders is expected to be widely used in the field of cloisonné crafting in the future.

Microplastics have become a rising issue in due to its detection in oceans, rivers, and tap water. Although a large number of studies have been conducted on the detection and quantification in various water bodies, the number of research conducted on the removal and treatment of microplastics are still comparatively low. In the current research, the inflow and removal of microplastics were investigated for various drinking water treatment plants around the world. Addition to the investigation of filed research, a survey was also conducted on the current research trend on microplastic removal for different treatment processes in the drinking water treatment plants. This includes the researches conducted on coagulation/flocculation, sedimentation, dissolved air flotation, sand filtration and disinfection processes. The survey indicated mechanisms of microplastic removal in each process followed by the removal characteristics under various conditions. Limitations of current researches were also mentioned, regarding the gap between the laboratory experimental conditions and field conditions of drinking water treatment plants. We hope that the current review will aid in the understanding of current research needs in the field of microplastic removal in drinking water treatment.

The removal of organic carbon and nutrients (i.e. N and P) from wastewater is essential for the protection of the water environment. Especially, nitrogen compounds cause eutrophication in the water environment, resulting in bad water quality. Conventional nitrogen removal systems require high aeration costs and additional organic carbon. Microbial electrochemical system (MES) is a sustainable environmental system that treats wastewater and produces energy or valuable chemicals by using microbial electrochemical reaction. Innovative and cost-effective nitrogen removal is feasible by using MESs and increasing attention has been given to the MES development. In this review, recent trends of MESs for nitrogen removal and their mechanism were conclusively reviewed and future research outlooks were also introduced.

Adsorption by granule activated carbon(GAC) is recognized as an efficient method for the removal of perfluorinated compounds(PFCs) in water, while the poor regeneration and exchange cycles of granule active carbon make it difficult to sustain adsorption capacity for PFCs. In this study, the behavior of PFCs in the effluent of wastewater treatment plant (S), the raw water and the effluents of drinking water treatment plants (M1 and M2) located in Nakdong river waegwan watershed was monitored. Optimal regeneration and exchange cycles was also investigated in drinking water treatment plants and lab-scale adsorption tower for stable PFCs removal. The mean effluent concentration of PFCs was 0.044 0.04 PFHxS g/L, 0.000 0.00 PFOS g/L, 0.037 0.011 PFOA g/L, for S wastewater treatment plant, 0.023 0.073 PFHxS g/L, 0.000 0.00 PFOS g/L, 0.013 0.008 PFOA g/L for M1 drinking water treatment plant and 0.023 0.073 PFHxS g/L, 0.000 0.01 PFOS g/L, 0.011 0.009 PFOA g/L for M2 drinking water treatment plant. The adsorption breakthrough behaviors of PFCs in GAC of drinking water treatment plant and lab-scale adsorption tower indicated that reactivating carbon 3 times per year suggested to achieve and maintain good removal of PFASs. Considering the results of mass balance, the adsorption amount of PFCs was improved by using GAC with high-specific surface area (2,500m2/g), so that the regeneration cycle might be increased from 4 months to 10 months even if powdered activated carbon(PAC) could be alternatives. This study provides useful insights into the removal of PFCs in drinking water treatment plant.