• 분석과학
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• 제35권5호
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• pp.197-204
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• 2022

A gas chromatography-mass spectrometric method was developed for determining 5-chloro-2-methyl-4-isothiazolin-3-one (CMIT), 2-methyl-4-isothiazolin-3-one (MIT), 1,2-benzisothiazolin-3-one (BIT), 3-iodo-2-propynyl butyl carbamic acid (IPBC) and benzoic acid (BA) in household products. A 0.5 g sample was placed in a test tube and dissolved with 5 mL water, 5 mL methylene chloride and 1.0 mL methanol. The solution was extracted by ultra-sonication followed by mechanical shaking using the salting out effect. Under the established condition, the lowest quantification limits of all analytes were in the range of 0.04-10 mg/kg and their relative standard deviations were less than 8.0 %. The method was used to analyze 10 household products. As a result of analyzing 10 household products, MIT was detected in the range of 1.2-3.5 mg/kg in 3 of 10 samples, CMIT was detected in the range of 2.6-8.2 mg/kg in 3 of 10 samples, and BA was detected in the range of 5.0-15 mg/kg in 4 of 10 samples. Meanwhile, BIT and IPBC were not detected in any of the products. It has been shown that this method can be used for the simultaneous determination of biocides with various physical and chemical properties in household products.

• 멤브레인
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• 제27권3호
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• pp.232-239
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• 2017

본 연구에서는 사용 후 폐기되는 정수기용 역삼투(Reverse Osmosis; RO)막 필터를 세정하여 새 필터의 수준으로 복원시키는 연구를 수행하였다. 화학적 세정액으로는 수산화나트륨, 중아황산나트륨, EDTA용액을 사용하였으며 마이크로버블 발생 장치와 함께 in-situ의 방법으로 세정하였다. EDTA를 0.1%의 농도로 제조한 뒤 마이크로버블과 함께 사용하여 30분 세정하였을 때 가장 좋은 결과를 나타내었다. 이때 폐 필터와 세정 후 폐필터의 성능을 비교해 보았을 때 투과도는 19.9%, 회수율은 49.5%증가하였으며 NaCl 100 mg/L 용액에 대한 염제거율은 2.3% 감소되었는데, 이는 새 필터와 동등한 수준으로 회복이 되었다. 또한 전자현미경 분석을 이용하여 막 표면의 오염물의 제거를 육안으로 확인하였다. 이로써 전량 매립 또는 소각 되어지는 정수기용 폐 RO막 필터의 세정을 통하여 재사용이 가능할 것으로 판단된다.

• Journal of Plant Biotechnology
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• 제41권3호
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• pp.123-126
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• 2014

This paper is suitable for household plant factory by design and using both energy-saving LED and solar technology. Conventional household plant factory only depending on natural sunlight is sensitive for the change of external environment. Another a big problem of conventional common household plant factory is large power consumption. Recently interest in wellbeing food such as chemical-free is increased abruptly. To solve these two problems, this paper describes hybrid type of household plant. In particular, reducing the power photosynthesis photon flux density (PPFD) is kept uniform to enhance the growth of the plant. Ambient light sensor is adopted for the control of proper combination of sunlight and LED to keep PPFD constant.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2007년도 춘계학술대회
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• pp.113-116
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• 2007

The fuel cell which converts directly chemical energy of fuel into electric energy has higher efficiency than the conventional power generation which involves several additional processes. Especially, polymer electrolyte membrane fuel cell (PEMFC) of which the electrolyte is a thin proton conductive polymer membrane is affordable for portable power applications and small-scale distributed power generation including household and small building. It is very important to not only increase the efficiency of FC itself but determine the optimal operation mode. The optimal operational planning of lkW household PEMFC system based on the daily electricity and heat demand patterns was performed. The estimated economic gain was up to 20% by adoption of PEMFC system.

• 대한화장품학회지
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• 제44권2호
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• pp.133-139
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• 2018

화학적으로 손상된 모발은 모발 자체의 물리적 특성이 약해져서 일상생활 중에 외부 자극에 취약하다. 본 연구의 목적은 모발 케라틴 단백질간의 화학적 결합이 모발의 인장강도를 회복이 반복적인 빗질 하에서 더 이상의 모발 악화를 방지하는지 여부를 결정하는 데 있다. 손상된 모발은 펌 시술을 통해 얻었다. 펌 손상 모발을 관능성 가교제인 3-aminopropyltriethoxysilane (APTES)을 이용하여 실란 커플링 및 카르보디이미드 반응을 통해 모발 내부에 가교 결합이 형성되도록 처리하였다. 인장 강도, 영률 및 고원 응력(plateau stress)을 포함한 물리적 특성을 측정하여 내부 가교 결합의 효과를 확인하였고, 가교 결합의 존재는 Fourier transform infrared (FT-IR) 분광법으로 확인하였다. 모발 절단 및 갈라짐의 정도는 건조 상태 모발의 반복적 빗질 시험으로 평가하였다. 결과적으로 화학적으로 손상된 모발의 물리적 성질은 내부 가교 결합으로 회복되었다. APTES의 실란 커플링 및 카르보디이미드 반응의 결합은 FT-IR 스펙트럼으로 확인하였다. 열을 가하면서 반복적으로 빗어 낸 후 모발의 절단 및 갈라짐 방지가 확인되었다. 인간의 모발은 펌 시술을 포함한 화학적 손상으로 약화될 수 있으므로 이러한 특성을 복원하는 것은 헤어 케어 업계의 주요 과제다. 본 연구에서는 화학적 결합을 통해 손상된 모발의 내부에 가교 결합 형성이 모발의 건강을 회복시키는 강력한 방법이 될 수 있음을 시사한다.

• 대한본초학회지
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• 제38권5호
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• pp.85-95
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• 2023

Objectives : This study was intended to reveal the chemical profiles of aerial(leaf, stem) and underground(rhizome, radix) parts of wild ginseng, and to investigate their anti-aging effects on human skin cells. Methods : Wild ginseng, estimated for over 20 years, was divided into the aerial and underground parts. Total phenolic contents of each extracts were measured using a Folin-ciocalteu method. The contents of 18 amino acids, 8 minerals and 27 ginsenosides were determined by GC-FID, ICP-MS and LC-MS, respectively. The anti-aging effects, including the radical scavenging activity, the activation of mitochondrial function on human fibroblasts, and the proliferation activity on human keratinocyte progenitor cells, for the whole plant and underground part of wild ginseng were evaluated. Results : The total phenolic acids, amino acids, and minerals in the aerial part were more than twice as high as in the underground part. Compared to the cultivated ginseng root, there were various types of ginsenosides in both parts of wild ginseng, and the total amount was more than twice as high. In particular, the aerial part significantly contained ginsenoside F1, F2, C-Mc1, and C-O, and the distinctive patterns that distinguish each parts of wild ginseng from the cultivated ginseng root were derived. The whole plant and underground part of wild ginseng exhibited significant antioxidant effect(14.3-45.6%), activation of mitochondrial membrane potential(105.5-120.1%), and cell proliferation(112.1-125.4%). Conclusions : The entire plant and underground part of wild ginseng are high value-added plants and have beneficial effects on skin anti-aging properties through its abundant metabolites.

• Environmental Engineering Research
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• 제20권4호
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• pp.363-369
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• 2015

This study aims to characterize solid household waste and to present physicochemical characteristics of fresh leachate before landfilling in Kasba Tadla city, Morocco. Obtained results show that household waste produced in 2013 were about 11,787 tons, or 0.27 tons/capita/year. These wastes were composed essentially of organic materials (74%), paper (8%), plastics (9%), metals (1%), and glass (0.5%). However, monthly produced leachate ranges from a maximum of $130.92m^3$ during summer and a minimum of $21.88m^3$ in winter. Moreover, leachate treatment using Upflow Anaerobic Sludge Blanket technique was accompanied by a decrease in electrical conductivity, certainly related to leachate-sediment chemical exchanges. Otherwise, the same acidity reduction phenomenon occurs when pH value increased from 4.49 to 6.17 after 24 hours, confirming the system response since the early stages of treatment. In addition, temporal evolution of the treatment efficiency in terms of COD highlighted a very important reduction which reached 94% after 5 days with an average temperature of $25^{\circ}C$.

• Environmental Analysis Health and Toxicology
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• 제31권
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• pp.24.1-24.7
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• 2016

The humidifier disinfectant disaster (HDD) was not a simple poisoning accident by biocides, but a singular disaster in history created by chemicals in household products. This disaster was a result of the failure of a system for the management of chemical and product safety. Since the management authority for chemical usage safety is different from those for chemical safety in products, many blind areas for chemical safety management in products still remain. The 'Act on the Registration and Evaluation, etc. of Chemical Substances (ARECS)' or the new 'Biocidal Product Act' must not only address the blind areas in the management system for chemical and product safety, but also prevent a second HDD. To prevent another HDD, an integrated registration, evaluation, and management system for chemicals and consumer products must be incorporated into the 'ARECS' as an essential part for chemical safety in consumer products.

• 한국환경보건학회지
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• 제48권4호
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• pp.195-205
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• 2022

Background: The biggest concern when using household chemical products is the health risk from inhalation exposure. Objectives: The purpose of this paper was to provide information necessary for estimating inhalation exposure factors in several countries/organizations and to present some examples. Methods: We attempted to use PRISMA-ScR for a systematic review, but no major reports were found. We used the Google search function instead to find 'exposure factor handbook'. As for the results, inhalation exposure factors from South Korea, the United States, Canada, the EU, Australia, Japan, and China were compared. Results: The basic concept and origin of exposure factors was the US Environmental Protection Agency's Exposure Factor Handbook. Its latest version is 2011, but several chapters have been updated in 2017, 2018, and 2019. South Korea's Exposure Factor Handbook was updated in 2019, more recently than those of other countries, and was systematically investigated. In South Korea, the average daily respiratory rate is 14.62 m³/day for adults and 12.73 m³/day for children. It is difficult to compare breathing rate by country because each country divides age groups differently and uses different methods to estimate it. Information on household chemical products, space used, and ventilation rate are in the exposure factor handbook in some countries and not in others. It is not in the handbook in South Korea, but in the notice from the NIER (National Institute of Environmental Research), a sub-regulation of the Chemical Product Safety Act. Conclusions: The exposure factors registered in South Korea's exposure factor handbook have been systematically studied and reflect the most recent data. When using data not in the relevant handbook, data from other countries might be applied, but it should be determined whether the nature and quality of the original data have been managed.

• 대한화장품학회지
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• 제45권1호
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• pp.95-103
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• 2019

입술은 각질층이 매우 얇아 수분증발에 취약하며, 노화 과정에서 주름이 증가하고, 붉은색을 잃으며, 볼륨이 감소하게 된다. 매력적인 입술을 가지기 위해 시행되는 지방이식, 필러 주입을 대체하기 위한 성분에 대한 연구는 아직 보고된 바가 거의 없으며, 최근 새로운 지방세포의 수를 증가시키는 것이 인체 내 지방을 늘릴 수 있는 방법으로 제안되고 있다. 우리는 선행연구에서 지방줄기세포를 지방세포로 분화 유도하는 천연물질로써 요엽후박나무 추출물(Magnolia officinalis bark extract)의 우수한 효능을 확인하였다. 본 연구에서는 요엽후박나무 추출물이 바이오 프린팅으로 제작한 지방 유사 구조체에서 지방(lipid droplet)의 양을 증가시키면서 분화를 촉진시킴을 3D 수준에서 확인하였다. 다음으로 입술 주름에 미치는 영향을 확인하기 위해 주름 사진으로 부터 명암값의 표준편차(SDGV)를 J 이미지 소프트 웨어를 사용하여 측정함으로써 객관적 측정 방법을 확립하였고, 주름 정도에 따른 입술 주름 그레이드를 도출하여 정량화하였다. 결과적으로 요엽후 박나무 추출물 1%를 함유한 제품을 12주간 사용했을 때, 입술 주름을 유의하게 개선시킬 수 있음을 확인하였다. 본 연구 결과는 요엽후박나무 추출물이 지방줄기세포를 지방세포로 분화 유도하는 효능을 가지며, 이러한 효능이 입술 주름을 개선하는데 도움을 줄 수 있다는 점을 시사하고, 따라서 요엽후박나무 추출물은 입술 주름과 볼륨을 개선하는 화장품 후보 소재로 적용 가능하다는 것을 보여준다.