This study sought to improve the accuracy of estimating national emissions of volatile organic compounds (VOCs) from consumer solvent products (CSPs) by updating emission factors and category-specific activity data. The classification of the CSPs, which was originally proposed by the U.S. Environmental Protection Agency, was reorganized to reflect domestic consumption patterns in Korea. VOC contents, product sales, and atmospheric evaporation rates of the CSPs were analyzed for subcategories including personal care products, household products, and automotive aftermarket products to update their emission factors. Additionally, the category-specific activity data, previously based on only population statistics, were newly applied to count the characteristics of each classification, such as the number of households and the number of registered automobiles. The updated emission factors were calculated to be 1.90 kg/capita·yr for personal care products, 4.37 kg/household·yr for household products, and 2.36 kg/car·yr for automotive products. An evaluation of uncertainties revealed the limitation in the product classification, the shortage of sales data, and the lack of information on VOC contents depending on the product forms (liquid, solid, and aerosol). This study highlighted the necessity of developing detailed classification systems and standardized VOC content measurement methods, ultimately contributing to more accurate and practical assessments of VOC emissions from the CSPs.

Oxidative stress caused by reactive oxygen species (ROS) is a key mechanism of skin aging, and the use of antioxidants is an effective strategy to prevent the symptoms associated with ROS-induced skin aging. The components rich in polyphenolic compounds with antioxidative activity were identified by fractionating an aqueous ethanolic extract of Gryllus bimaculatus (AE-GBE) using solvent using hexane, chloroform, ethyl acetate, butanol, and water. Their ability to migrate H2O2-induced oxidative stress in human dermal fibroblasts (HDFs) was then evaluated. The butanol fraction of AE-GBE had the highest polyphenol content and antioxidant effect, followed by the ethyl acetate and water fractions, suggesting that the likely antioxidant components are polar components. Furthermore, the butanol, ethyl acetate, and water fractions effectively reduced intracellular ROS production and DNA damage in HDF cells caused by H2O2. Overall, these findings suggest that the butanol fraction of AE-GBE shows promise as a natural insect-derived antioxidant material, capable of suppressing oxidative stress by showing a stronger antioxidant effect under H2O2 stimulation than the other fractions.

본 연구는 폴리케톤(PK) 지지체를 이용한 유기용매 역삼투(OSRO) 분리막 제조를 목적으로 하였다. 비용매 유도 상분리 방법(NIPS)을 통해 PK 지지체를 제작하였고, PK 지지체 위에 polyamide layer를 계면 중합하여 thin-film composite (TFC) 형태로 OSRO 분리막을 완성하였다. 이후 OSRO 분리막의 표면과 단면 구조 및 표면의 화학적 구조를 분석하였고 수 투과도와 염 제거율은 각각 약 1.28 LMH/bar와 99.0%의 결과를 얻었다. 또한 OSRO 분리막의 polyamide layer는 유기용매 침지 1일 동안 매우 안정적이었고, 단일 유기용매 투과도 경향성은 유기용매 나노여과(OSN) 분리막의 투과도 모델과 일치하 였다. OSRO 분리막의 MWCO는 MeOH 상에서 240 g/mol이었다. OSRO 분리막의 MeOH-toluene 혼합용액에 대한 투과도 와 separation factor는 상용 OSN 분리막보다 각각 200%와 60%의 높은 결과를 얻었다.

Broccoli and cabbage are known to have antioxidant, cholesterol-lowering, and anticancer effects due to their high bioactive component levels. This study applied 70% ethanol and hydrothermal extraction to separate bioactive components from broccoli and cabbage. 30oBrix extracts were freeze-dried and then diluted in various concentrations with distilled water for analysis. Total polyphenol contents, DPPH radical scavenging activity, ABTS radical scavenging activity, ferric ion reducing antioxidant power, and hydrogen peroxide scavenging activity were analyzed. The diverse antioxidant assays, except DPPH radical scavenging activity, showed that hydrothermal extracts had significantly higher activity than the 70% ethanol extracts (p<0.05). In this study, it suggested that hydrothermal extraction is relatively effective in producing broccoli and cabbage extracts. Moreover, hydrothermal extraction conditions could be low-cost and environmentally friendly.

The detailed understanding of fluorescence emission processes is still unclear. This study demonstrates Aegle marmelos derived luminescent heteroatoms (N, Ca, K) doped carbon quantum dots (CQDs) using an economically and ecologically sustainable synthesis process without the necessity for any doping precursors due to its phytochemical, vitamin and mineral content. Carboxyl functionalization was done by adding lemon juice to the fruit extract. The morphological, physiochemical, compositional, crystallinity, and surface functional groups having heteroatom doped CQDs were analysed by HRTEM, EDX, XPS, XRD, FTIR etc. Besides, CQDs exhibited pH and solvent-dependent tuneable fluorescence characteristics. In fact, beyond pH 7.77, a protonation-deprotonation-driven red-shift was observed together with a decrease in the contribution of prominent peaks. Meanwhile, the features of solvatochromic fluorescence were examined in a range of aprotic and protic solvents with low and high polarity. Based on the studied Kamlet–Taft parameters and the obtained spectroscopic characterizations, a suitable fluorescence emission mechanism is provided. The observed solvatochromic fluorescence is thought to be caused by a combination of dipole moment polarisation, intramolecular charge transfer processes with or without H-bond stabilisation via the interaction of heteroatoms doped CQDs with solvent mediated by electron donation and acceptance from various surface functional groups such as hydroxyl, carboxyl with solvent molecules. Hence, this study is believed to promote the development of eco-tuneable fluorescent heteroatom doped CQDs and provide further insights into the fundamental fluorescence mechanisms, which include the relationship between morphology, surface properties and plausible quantum effects between CQDs and solvents.