• 에너지공학
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• 제26권1호
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• pp.62-67
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• 2017

Limestone is an important commodity in Philippines. Limestone has numerous uses that range from agricultural applications to building materials to medicines. Many limestone products require rock with specific physical and chemical characteristics. Most limestone is biochemical in origin meaning the calcium carbonate in the stone originated from shelled oceanic creatures. In this paper, we reported the natural sources of limestone, geological formation of limestone and the oyster shell waste in Cebu, Bantayan, Philippines were reported. Due to the mining or quarrying in Cebu, Bantayan, in a limestone area poses the threat of groundwater pollution (since limestone is a porous geologic formation with a high transmissivity). The other environmental issue is oyster shell waste. The oyster shell waste is the major source of limestone. We developed and applied appropriate technologies for the extraction of limestone from oyster shell waste and utilizes as high value added material.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-1
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• pp.79-80
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• 2003

A lot of polyketide antibiotics have been isolated from natural sources like microorganism, fungi and plant. The polyketide natural products have biologically and medically important activities, including antibacterial, anticancer, antiparasitic, and immunosuppressant properties. The diversified activities of polyketides are originated from their structural variety of which have been took advantage by several research groups for development of new drugs. (omitted)

• 대한치과의사협회지
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• 제50권9호
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• pp.544-551
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• 2012

Dental caries is a biofilm-related oral disease, and continues to afflict the majority of the world's population. Although fluoride, delivered in various modalities, remains the mainstay for the prevention of caries, additional approaches are required to enhance its effectiveness. Natural products have been used as a major source of innovative and effective therapeutic agents throughout human history, and have shown promise as a source of components for the development of new drugs. In addition. studies using natural products to prevent or treat oral diseases such as dental caries have received a great deal of attention. A number of compounds, such as epicatechin, allicin and sanguinarine, isolated from natural products, have also been investigated for their efficacy against oral microbial pathogens. However, the use of natural products as an anti-caries agent in clinical practice was controversial because of inadequate knowledge concerning their mechanisms of action and chemical characterization. This study focuses on the current knowledge of natural products in dental caries prevention and suggests natural products are importance sources for the prevention of dental caries.

• 한국식품영양과학회지
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• 제42권4호
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• pp.497-504
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• 2013

본 연구에서는 4종의 천연칼슘소재를 이용하여 칼슘 이온화 특성 및 in vitro 칼슘 이용률을 조사하였다. 천연칼슘소재는 8.0%(w/v) 첨가농도까지 칼슘용해량과 칼슘이온 함량은 증가하였으나 이상의 농도에서는 큰 변화는 없었다. 또한 이온화율은 약 90%로, 칼슘소재와 첨가농도에 따른 큰 차이는 나타나지 않았다. 칼슘의 이온화에 용해온도는 큰 영향이 없었으며, 용해 18시간째 가장 높은 칼슘이온 함량을 나타났다. 칼슘액 중 BS의 in vitro 칼슘 이용률은 67.3%로 가장 높게 나타났으며, AS는 62.4%, DS는 57.9%, CS는 57.5%로 시판 칼슘제 및 천연칼슘소재에 비해서 약 2배 정도 높게 나타났다. 시판 우유, 두유 및 오렌지 주스의 in vitro 칼슘 이용률을 조사한 결과 탄산칼슘보다 이온화 칼슘액을 첨가한 구간에서 2배 이상 높게 나타났다. 따라서 천연칼슘소재의 이온화 칼슘은 생체 이용율이 높은 다양한 식품소재로 활용이 기대된다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 춘계학술대회
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• pp.410-411
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• 2006

On the continental margins and in permafrost regions, natural gas, which has been expected to replace petroleum energy, exists In solid hydrate farm. World hydrate reserves Including natural gas are estimated at about twice as much as the energy contained In total fossil fuel reserves. Because of its vast quantities, the efficient recovery of natural gas from natural gas hydrate becomes the most important factor on evaluating the economic feasibility in the sense of commercialization. It has been noted that carbon dioxide, one of the well-known green house gases, possibly can be stored in the ocean floor as a carbon dioxide hydrate. If the natural gas hydrate could be converted into carbon dioxide hydrate, natural gas hydrate deposits would serve as energy sources as well as carbon dioxide storage sites in the deep ocean sediments. In this study, we first attempted to examine the real swapping phenomenon occurring between guest molecules and various structures of gas hydrate through spectroscopic identification such as NMR spectroscopy.

• 생명과학회지
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• 제31권11호
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• pp.1046-1055
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• 2021

바닐린은 천연 바닐라의 주요 향미 화합물이며 식품, 음료, 향수, 제약 산업 및 기타 응용 분야에서 광범위하게 사용된다. 바닐린은 화학합성법, 바닐라 꼬투리를 이용한 식물추출법, 천연 전구체를 이용한 생물전환법, 그리고 포도당을 사용한 직접 발효법에 의해 생산될 수 있다. 현재 상업적으로 이용 가능한 대부분의 바닐린은 큐어링 공정을 거쳐 얻어진 바닐라 꼬투리에서 추출하는 방법과 구아이아콜과 글리옥실산을 원료로 사용하여 화학적 합성법에 의해 생산된다. 환경 문제, 건강 준수, 천연 원료에 대한 선호, 천연 바닐라의 제한된 공급 및 치솟는 가격으로 인해 생명 공학 기반 바닐린 생산은 유망한 대안으로 간주된다. 페룰산, 유제놀, 이소유제놀, 리그닌을 포함한 여러 천연 전구체를 대사하고 바닐린을 축적할 수 있는 많은 미생물이 선별되고 평가되면서, 상업적으로 실행 가능한 생산 기술 개발을 위해 많은 노력을 기울였다. 본 총설은 이러한 천연 전구체를 사용하여 천연 바닐린의 생물공학적 생산에 대한 최근의 발전을 간략하게 설명한다. 또한, 포도당에서 바닐린의 새로운 생합성 경로를 기반으로 재생 가능한 탄소원에서 천연 바닐린을 생산하기 위한 최신의 개발 전략과 생산 농도를 높이는 데 발생하는 문제를 극복하기 위한 적절한 해결방안을 소개한다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2003년도 총회 및 춘계학술발표회
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• pp.63-66
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• 2003

This study applied a hydrogeological field survey and isotope investigation to identify source locations and delineate pathways of groundwater contamination by nitrogen compounds. The infiltration and recharge processes were analyzed with groundwater-level fluctuation data and oxygen-hydrogen stable isotope data. The groundwater flow pattern was investigated through groundwater flow modeling and spatial and temporal variation of oxygen isotope data. Based on the flow analysis and nitrogen isotope data, source types of nitrate contamination in groundwater are identified. Groundwater recharge largely occurs in spring and summer due to precipitation or irrigation water in rice fields. Based on oxygen isotope data and cross-correlation between precipitation and groundwater level changes, groundwater recharge was found to be mainly caused by irrigation in spring and by precipitation at other times. The groundwater flow velocity calculated by a time series of spatial correlations, 231 m/yr, is in good accordance with the linear velocity estimated from hydrogeologic data. Nitrate contamination sources are natural and fertilized soils as non-point sources, and septic and animal wastes as point sources. Seasonal loading and spatial distribution of nitrate sources are estimated by using oxygen and nitrogen isotopic data.

• Ecology and Resilient Infrastructure
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• 제1권2호
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• pp.102-108
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• 2014

비점오염저감시설에 대한 연구는 활발히 진행되고 있으나, 도로에 자연형 비점오염저감시설 설치시 비점오염저감효율에 대한 연구는 없는 실정이다. 본 연구에서는 도로에 설치된 여러 종류의 인공습지에 대한 비점오염 저감효율을 모니터링과 유량가중평균농도법을 이용하여 분석하였다. 분석결과, 인공습지는 일반적인 오염물질인 TSS, COD, BOD, TN, TP에 대한 저감효율은 비교적 우수한 것으로 나타났으며 중금속인 Cr, Zn, Pb의 제거효율은 낮거나 거의 없는 것으로 나타났다.

• Archives of Pharmacal Research
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• 제25권6호
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• pp.725-746
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• 2002

The demand for new alternative "low calorie" sweeteners for dietetic and diabetic purposes has increased worldwide. Although the currently developed and commercially used highly sweet sucrose substitutes are mostly synthetic compounds, the search for such compounds from natural sources is continuing. As of mid-2002, over 100 plant-derived sweet compounds of 20 major structural types had been reported, and were isolated from more than 25 different families of green plants. Several of these highly sweet natural products are marketed as sweeteners or flavoring agents in some countries as pure compounds, compound mixtures, or refined extracts. These highly sweet natural substances are reviewed herein.

• Journal of Microbiology
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• 제42권1호
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• pp.51-55
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• 2004

The influence of feedstock amino acids, salt, carbon and nitrogen sources on glutathione production by Saccharomyces cerevisiae FF -8 was investigated. Glucose, yeast extract, KH$_2$PO$_4$, and L-cysteine were found to be suitable feedstock. Highest glutathione production was obtained after cultivation with shaking for 72 h in a medium containing glucose 3.0% (w/v), yeast extract 3.0%, KH$_2$PO$_4$ 0.06% and L-cysteine 0.06%. The glutathione concentration achieved using this medium increased 2.27-fold to 204 mg/l compared to YM basal medium.