• 제목/요약/키워드: natural chemicals

검색결과 328건 처리시간 0.03초

습윤준설토와 노건조준설토의 약품처리 후 공학적 특성에 관한 실험적 연구 (An Experimental Study on Engineering Characteristics of Wet Dredged Soil and Dry Dredged Soil after Chemical Treatment)

  • 장용채;박기윤;박종철;이인규
    • 한국지반환경공학회 논문집
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    • 제13권3호
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    • pp.71-76
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    • 2012
  • 자연상태의 퇴적물과 준설과정을 거친 준설토 사이에는 퇴적물이 안정상태에서 교란되기 때문에 수질의 탁도가 좋지 않으며, 다시 침강 시 체적변화가 발생한다. 이에 수질의 탁도를 좋게하고 준설토의 부유물질의 침강을 촉진하기 위하여 투입되는 응결제 및 응집제의 양에 따라 준설토는 다양한 특징을 보인다. 본 연구에서는 자연상태의 습윤준설토와 노건조준설토에 약품회사 A, B, C사의 약품투입량에 따른 준설토의 부유물질(SS)측정, 체적변화 및 침강속도의 특성분석을 파악하고자 연구를 수행하였다. 실험 결과 습윤준설토와 노건조준설토의 약품량이 많을수록 부유물질(SS)측정은 낮아지고, 체적변화율은 증가하는 경향을 보이고 있으며, 침강속도는 빨라지는 경향을 보였다. 또한 습윤준설토와 노건조준설토의 약품량의 차이는 노건조준설토 경우 $100{\pm}5^{\circ}C$에서 건조시키기 때문에 유기물 및 미생물이 소멸하여 적은 양으로도 약품에 민감한 반응을 보이는 것으로 판단된다.

A Study at Investigating the Climate Change in East Asia with Changing Sea Surface Temperature

  • Park, Geun-Yeong;Lim, Yong-Jae
    • 통합자연과학논문집
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    • 제13권1호
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    • pp.27-33
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    • 2020
  • The unsustainable human activities like increased use of automobiles, heavy industrialization and the use of large volumes of fertilizers, chemicals and pesticides in the agricultural land cause climate change problems in one way or another. Under normal circumstances, the heat radiations from the sun will be reflected back. An excessive volume of GHGs in the atmosphere would prevent these radiations from reflecting back. East Asia is facing severe climate change issues in recent times. A lot of climate change problems such as hurricanes and floods have been reported from this region in the last couple of decades. The study aimed at investigating the climate change in East Asia with changing Sea Surface Temperature (SST). The study adopted a quantitative research method with a case study research design where a deliberate focus was made on the East Asia Region. Secondary data was gathered and analyzed to yield both descriptive and inferential statistics. The study concluded that the impact of East Asia Climate variability was significant mainly for some extreme events. Also, the study concluded that there was a significant link between the change of the East Asia climate variability and that of the sea surface temperature. Further, the study concluded that a linear relationship existed between the sea surface temperature and the climate of East Asia. Hence, a linear regression was a significant predictor of the East Asia Climate (EAC) based on changing sea surface temperature. The model revealed that 37.4% of the variations in the climate change index were explained by the changes in the sea surface temperature. The climate was expected to change with a value of 49.48 for a unit change in the sea surface temperature.

합성가스로부터 탄화수소제조를 위한 피서트롭스 반응에 관한 촉매 종류 및 반응매체의 영향 (Effect of Catalyst Type and Reaction Medium on Fischer-Tropsch Synthesis for Production of Hydrocarbon from Syngas)

  • 김철웅;정순용;정광은;고재천;채호정;김태완;박현주;이상봉;한정식;정병훈
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2010년도 제35회 추계학술대회논문집
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    • pp.658-663
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    • 2010
  • 석유자원의 고갈에 따라 전 세계적으로 석유대체자원인 석탄, 천연가스 및 바이오매스로부터 합성 연료 및 화학물질을 제조하기 위한 피셔트롭스 반응에 관한 많은 연구가 이루어지고 있다. 일반적으로 이러한 피셔트롭스 반응은 주로 스케일 업이 비교적 용이한 고정층 반응기를 사용한 기상반응이 적용되고 있으나, 촉매 기공에서의 확산제어 및 왁스의 생성에 따른 촉매의 비활성화 등의 문제점에 기인하여 최근 들어 초임계 유체를 이용한 반응이 많이 연구되고 있다. 본 연구에서는 피셔트롭스 반응에 관한 담지 촉매 및 반응매체에 관한 좀 더 심도 있는 영향을 고찰하기 위해 다양한 담지촉매를 제조하여 피셔트롭스 반응에 관한 기상반응과 초임계 반응을 비교, 고찰하였다.

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The Effects of Natural Material Extracted from Rice Bran on Skin in vivo

  • Zhoh, Choon-Koo;Han, Chang-Giu;Hong, Se-Heum;Takuo Tsuno
    • 대한화장품학회:학술대회논문집
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    • 대한화장품학회 2003년도 IFSCC Conference Proceeding Book II
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    • pp.253-267
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    • 2003
  • Inositol and phytic acic extracted from rice bran were investigated for applying cosmetics. Skin lotions containing 0∼3.0wt% inositol and 0∼1.5wt% phytic acid were applied respectively, to the arm skins of 45 Asian women 20'-40's for 7 weeks. Improvement on moisture was evaluated. In addition, improvements on sebum, elasticity, and wrinkle were examined after applying placebo, Inositol and phytic acid-containing skin lotions for face, respectively. For 1.0 wt% inositol resulted in 19% increase of moisture. The wrinkle reduction and elasticity improved 12.4% and 17.0% on average, respectively. Applying 0.5wt% phytic acid resulted in 71.6% increase the moisture. Improvements on wrinkle and elasticity were 15.9% and 21.9% respectively. Applying inositol or phytic acid regardless of dry or oily, resulted in sebum value recovery to that of the normal skin after 2- 4 weeks. Inositol is inferior to phytic acid in improvenients of the skin, and phytic acid is not suitable to sensitive skin. So 0-0.5wt% of phytic acid were added to 1.0wt% inositol and similar experiments were carried out. In case of added 0.1wt% phytic acid, moisture increased 63.8% approximately. Improvements on elasticity and reduction on wrinkle were 17.2% and 17.4%, respectively. Both skin types were turned to normal skin type after 2 weeks. It could improve the skin condition when used inositol added phytic acid. The optimized concentration of phytic acid was 0.10wt% with 1.0wt% of inositol for synergic effect.

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Antifungal Activity of Lagenaria breviflora Fruit Extracts Against Wood Rotting Fungi on Vitex doniana Wood

  • Adedeji, Gabriel Adetoye;Eguakun, Funmilayo Sarah;Elufloye, Taiwo Olayemi;Uriel, Tamunobubeleye
    • Journal of Forest and Environmental Science
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    • 제33권4호
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    • pp.322-329
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    • 2017
  • As a result of contemporary environmental concerns, a number of studies from plants' tissues as one of the alternatives to conventional chemicals are increasingly investigated. In tandem with these trends, Lagenaria breviflora (LB) fruit, reputed as antiviral and depilatory agents in the Yoruba folkloric medicine was examined on Vitex doniana wood to ascertain its antifungal activity. Fungicides of 25%, 50%, 75%, and 100% LB fruits formulations (concentrations) were developed through simple one-step mechanical-forming process, including control. In this study, the yield, the chemical compositions, the absorption capacity of the fungicides and wood weight losses (WWL) analysis were evaluated to investigate the antifungal activity of LB fruit on wood. The fruit extract yielded 35.4% of fresh juice weight. LB fruits contained total: alkaloids ($8.78{\pm}0.21mg/mL$), flavonoids ($2.01{\pm}0.02mg/mL$), phenol ($7.42{\pm}0.09mg/mL$), saponins ($11.00{\pm}0.10mg/mL$) and tannins ($5.47{\pm}0.05mg/mL$) contents. All the formulations provided effective protection against the tested wood fungi compared to control. Interestingly, the antifungal activity of 50% and 25% formulations of 6.8% WWL and 9.9% WWL satisfied the excellent fungal resistance class description against white rot fungus (Ganoderma lucidum) and brown rot fungus (Fibroporia vaillantii), respectively according to ASTM D 2017. These results thus, support LB fruit as a strong potential source of natural antifungals for industrial wood production.

한반도에서 지속농업의 실천방안 지속적 벼 생산체계 개발을 중심으로 (Practices of Sustainable Agriculture in Korea With References for the Development of Sustainable Rice Production Systems)

  • 최진룡;김정부;조영손
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 1998년도 21세기 한반도 농업전망과 대책(한국작물학회.한국육종학회 공동주관 심포지움 회보)
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    • pp.288-312
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    • 1998
  • In Korea, chemical fertilizers and agricultural chemicals have had a significant impact on food production and these are today thought to be an indispensable part of modern agriculture. On the other hand, socioeconomical and IMF and WTO status in Korea are constant reminders of the vulnerability of our fossil fuel dependent agriculture. A new crop production system to improve economic, environmental and production efficiency must be exploited. Our particular concern has been given to an integrated cropping system involving recycling of crop residues, soil and N management, biological N fixation and multipurpose legumes. As a new integrated crop production system, a no-till direct-sown rice-vetch relaying cropping system has been proposed in this paper. The formulation of this system is based on the conception that N fertilizers being neither limitlessly available nor affordable, the current high-input crop production systems have produced troubled results severe labour shortage ill rural areas, balance of payment, environmental degradation and reduction of human health far exceed economic concerns. A natural and logical consequence is that long-term sustainability of agricultural systems must rely on the use and effective management of internal resources. Based on the information obtained throughout a series of experiments last years we have proved that the no-till direct-sown rice-vetch relaying cropping system dictates biological alternative which can augment, and in some cases replace, N fertilizers. Comprehensive discussions were made for the proposed system and it concluded that the system can offer an economically attractive and ecologically sound means of reducing external nitrogen input and improving the quality and quantity of internal resources, and consequently improving the farmers as well as the national returns.

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영아복을 위한 오가닉 코튼 브랜드의 제품디자인과 컬러 분석 -국내 브랜드와 일본 브랜드의 비교분석 (Products of Organic Cotton Brand and Color Analysis for Baby Wear-Comparative Analysis of Domestic and Japanese Brands)

  • 박혜령;정진호
    • 한국산학기술학회논문지
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    • 제15권2호
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    • pp.678-687
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    • 2014
  • 아기들의 피부는 매우 연약하고 환경 적응력이 아직 부족하기 때문에 화학약품 등에 의해 피부염을 유발할 가능성이 매우 높다. 또한 겉옷과 내의를 같은 기능으로 사용하는 영아복에 있어서 오가닉(유기농) 코튼은 가장 적합한 섬유라고 할 수 있다. 따라서 본 연구는 오가닉 코튼을 사용하는 국내의 영아복 브랜드와 일본의 영아복 브랜드의 제품 및 칼라 분석을 하고자 한다. 6개의 영유아 오가닉 대표 브랜드는 국내 3개와 일본 3개의 브랜드이고 총 213개 제품의 디자인과 컬러를 웹상으로 조사하였다. 비교 분석한 결과는 용도별 디자인에 있어서는 국내브랜드보다 일본브랜드가 더 많았다. 컬러분석은 모두 내츄럴한 코튼컬러를 선호하며 비교적 YR 계열이 많은 공통점이 있으나 일본의 경우 색상들이 비교적 폭넓게 분포하고 있는 반면 국내 브랜드는 비교적 폭이 좁게 나타났다.

마을환경개선을 위한 주민참여지표개발 (Development of Inhabitant Participation Index for the Village Environment Improvement)

  • 이관희;박종웅;권수광;김영표
    • 농촌계획
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    • 제9권2호
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    • pp.13-17
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    • 2003
  • A purpose of this study is to develop practical indexes for improving a village environment in Kyongbuk, Korea. From a questionnaire survey of the public employees (71 persons) who take charge of the environment in Kyongbuk province, the indexes were produced and the contents of questionnaire consisted of preferential and supplementary indexes to apply. The preferential indexes which apply to an agricultural village and a stock raising village are environmental sanitation facilities, a hygienic check of livestock and a purge of livestock shed's surroundings. In case of mountainous village, and natural-ecological village the preferential indexes are habitat reservation for wildlife, poaching prohibition (monitoring for it), and food supplement for livestock. To the traditional-cultural village, prevention of noise pollution, environmental sanitation facilities, and a monitoring or water quality change are the prior indexes in order. For the village near city and the industrial village the preferential indexes are patrol removing of garbage, pollution index planting and monitoring for noise pollution. For a fishing village and a village fronting waterside excess uses of agricultural chemicals, monitoring for a water quality change, and realignment of green house with vinyl and warehouse. In conclusion the research presents the practical and preferential index for residents to improve their environment in accordance with village settings and suggests guidelines for further research.

참나무재의 약액함침 처리가 폭쇄 및 산소-알칼리펄프화에 미치는 영향 (The Effect of Chemical Pretreatment on Steam Explosion and Oxygen-alkali Pulping of Oak Wood)

  • 박승영;최태호;조남석
    • 펄프종이기술
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    • 제33권3호
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    • pp.75-83
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    • 2001
  • The potential of oxygen delignification is a powerful tool to reduce detrimental environmental effects. This study was performed to investigate the effect of steam explosion treatment of chemically treated oak wood on oxygen-alkali pulping. Pulp yield during steam explosion treatment by ${Na_2}{O_3}$-NaOH impregnation was higher than the other impregnation chemicals. Also, NaOH extraction at room temperature after steam explosion treatment improved the kappa number from 140~116 to 90~64. Oxygen-alkali pulping of chemical steam explosion treated woods affected to pulp yields. ${Na_2}{O_3}$-NaOH impregnation was very effective to higher carbohydrate yields at same delignification level. Its carbohydrate yield seemed to be highly related to the effluent pH. Oxygen-alkali pulping after steam explosion treatment of ${Na_2}{O_3}$-NaOH impregnated wood was shown that carbohydrate yield was very high because its effluent pH was increase from natural to mild alkali. Even if oxygen bleaching limit the delignification to 50% in order to avoid unacceptable yield and viscosity losses, oxygen-alkali pulping after steam explosion by ${Na_2}{O_3}$-NaOH impregnation was possible to extend the delignification more than 80%. Considering high pulp yield with lower lignin content from steam explosion treated wood, it might be profitable to end the cook at a high kappa number instead of a low kappa number, and continuously apply the oxygen delignification, in order to better quality pulp.

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금잔화, 상황, 어성초 에탄올 추출물의 세포독성 평가 및 3T3-L1 세포에 대한 육모 효과 (Cell Viability and Hair Growth Effect on 3T3-L1 Cells of Ethanol Extract from Calendula officinalis L. Flower, Phellinus linteus Fruit Body and Houttuynia cordata Thunb. Whole Plant)

  • 진성우;고영우;윤경원;김경제;제해신;임승빈;김광상;김민숙;유병조;서경순
    • 한국약용작물학회지
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    • 제25권6호
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    • pp.404-410
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    • 2017
  • Background: Hair loss related syndromes are increasing due to environmental pollution and stress. Hair care products are mainly prepared by mixing chemicals and natural extracts, such as those obtained from medicinal plants. The purpose of this study was to investigate the effects of 70% ethanol extracts from the flowers of Calendula officinalis, fruit body of Phellinus linteus, and the whole plant of Houttuynia cordata on the growth of CCD-986 cells, hair follicle dermal papilla cells (HFDPC), and 3T3-L1 cells. Methods and Results: All sample extracts at all concentrations, except for that from P. linteus fruit body at $500{\mu}g/m{\ell}$, were cytotoxic to CCD-986 cells. However, none of the sample extracts were cytotoxic to HFDPC. The lipid differentiation of 3T3-L1 cells regulates hair regeneration via secretion of platelet derived growth factor. The 70% ethanol extract of H. cordata whole plant promoted hair growth. Adipogenesis rate significantly increased in a treatment concentration-dependent manner. Conclusions: These results suggest that 70% ethanol extracts of C. officinalis flower, P. linteus fruit body and H. cordata could be used for the development of hair care products.