• 한국축산시설환경학회지
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• 제3권1호
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• pp.13-18
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• 1997

This study was conducted to investigate the physicochemical changes during the aerobic composting of swine manure mixed with bulking agent, sawdust(v/v, 1:1), in a full-scale composting plant using rectangular escalator-aginated bed composting system. Physical and chemical properties were analyzed on the samples which were collected at 5, 15, and 25 day of composting, curing and final step. The results of this study were summarized as follows; 1. Moisture and K2O content, and pH of final step were higher than those of 5th day of composting (p＜0.05). 2. Ammonium nitrogen, total organic corbon and organic matter content, and electrical conductivity(EC) were significantly decreased (p＜0.05) but nitrate nitrogen, ash and P2O5 content increased(p＜0.05) throughout the aerobic composting process. 3. Total organic carbon per total nitrogen(C/N) and total organic matter per total nitrogen(OM/N) ratio were significantly decreased throughout the aerobic composting process(p＜0.05). 4. Physical and chemical properties of swine manure were varied by aerobic fermentation using rectangular escalor-aginated bed composting system.

• Tribology and Lubricants
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• 제19권3호
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• pp.159-166
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• 2003

This research for replacement of chlorine or sulfur based EP(extreme pressure) -additives which is restricted materials by environmental regulation. The subject of this study is as follows, 4-ball test and friction coefficient test were experimented in accordance with temperature and velocity, compounding with several organic or inorganic metallic elements. After 4-ball test, wear area of steel ball was analysed by SEM-EDX. As the analysis, organic and inorganic elements make a effect for extreme pressure lubricity. It is shown that the friction coefficient of lubricant which includes chlorine or sulfur additives, the scoring phenomenon is found accord-ing to temperature and the scuffing phenomenon at 200$^{\circ}C$. Applying to Na, P, S, Zn, Ca based on inorganic and organic elements, the result showed that friction coefficient is decreased more and more, as increasing temperature of lubricant. The additive based on S, Cl, P elements is effect far extreme pressure in the sample#1 and Na, P, S, Zn, Ca in sample #2. These elements are environmental contaminants and S, Cl based on EP additives which are very popular in domestic industry, when they are properly composed with non-chlorine based on additives and Na, P, S, Zn, Ca organic or inorganic elements. It is showed that lubricity and excellent anti-wear properties.

• 한국조리학회지
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• 제4권
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• pp.413-436
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• 1998

In order to guarantee the safety of Korean Naeng Myon Broth in summer, pH and micrological quality of iced noodle gravy which is cooked and sold in public restaurant were investigated. And the variations of pH, taste and microorganism were studied with organic acid treatment during storage period. The micrological status of iced noodle gravy showed that average number of total aerobic bacteria was 2.7${\times}$105CFU/$m\ell$ and fecal coliform was 8.3${\times}$103CFU/$m\ell$ respectly. Food poison microorganisms not detected and average of pH was 4.8. pH changed slightly during storage period and deceased with increasement of organic acid added. Sour taste of organic acid increased acetic acid, citric acid, lactic acid order and there was no organic acid having with more sour taste than iced noodle gravy which is cooked and sold in public restaurant. Salmonella was destroyed when treated with 1% of acetic acid and lactic acid and Escherichia coli became extinct at treatment with 0.8% acetic acid and 1% lactic acid. in case of same concentration, inhibition effects to Escherichia coli multiplication show citric acid, lactic acid, acetic acid order. In conclusion, treatment with more than 0.8% acetic acid and above 1.0% lactic acid or more than 1.0% citric acid in case of production and consumption a day can prevent from Escherichia coli pollution in Korean Naeng Myon Broth.

• 한국환경보건학회지
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• 제27권2호
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• pp.60-66
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• 2001

Natural organic matters(NOMs) are found everywhere such as soil, surface and ground waters and consist of both humic and nonhumic components, and their heterogeneith makes each source unique. This study was carried to evaluate the removal characteristics of NOMs by mixing coagulants and the variation of apparent molecular weight distribution(AMWD) in coagulation process. Ratio of optimum coagulants dosage for removal of DOC and turbidity by mixing coagulants was 1.83 mM F $e^{3+}$/mM $Al^{3+}$. DOC removal increased at lower pH. The pH6 control focused on the removal of organic matters could reduce the amount of coagulant consumption by 2 to 3 times based on the pH8.5 of natural water. The dissolved organic matters in the natural water from the mid-stream of Han River were composed of the low molecular weight(LMW,<1 K) of 59.7%, and the medium and high molecular weight(M.HMW, 1~30 K) of 40.3%, respectively. At pH6, the DOC removal efficiencies of LMW(<1 K) and M.HMW(1~30 K) in coagulation process were 27~35%, 62~72%, respectively. The fraction smaller than 1 K was not eliminated to a noticeable degree, while the fraction of 1~30 K was relatively well removed. In conclustion, mixing coagulants were fairly effective in the removal of natural organic matter.r.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 추계 학술논문 발표대회
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• pp.87-88
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• 2019

Research has been conducted in many fields for the zero energy of domestic buildings. Among them, the development of insulation has become an essential element. Accordingly, researches are being made to improve the performance of organic insulating materials, and PF boards having the lowest thermal conductivity among organic insulating materials have been in the spotlight. However, problems have arisen due to the problems of durability of insulation materials such as PF boards and past acidification, and the durability of insulation materials is deteriorated when moisture or water enters due to crack gaps during the insulation of the basement layer or the external insulation method. In regard to the durability of the insulation, when the organic insulators of different kinds were placed in water, the pH was weakly basic in all organic insulation materials except PF, and the PF was about 4 pH. As a result, the PF should be continuously reviewed, and further analysis should be carried out to determine what causes acidification.

• 한국물환경학회지
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• 제18권2호
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• pp.169-187
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• 2002

The effects of important parameters such as reaction time and pH on the Fenton's process were evaluated using a batch reactor. It was proven that organic materials and heavy metals in leachate could be successfully removed by Fenton's reagent. Favorable operation conditions were investigated. It was observed that the reaction between ferrous iron and hydrogen peroxide with the production of hydroxyl radical was almost complete in 10 minutes. That is, the oxidation of organic materials by Fenton's reagent was so fast that it was complete in 30 minutes with batch experiments. With the formation of carbonic acid, pH of the batch reactor decreased to favorable acidic conditions without acid addition. The oxidation of organic materials in the leachate showed a pH dependence and was most efficient in the pH range of 2-3.

• 한국균학회지
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• 제47권3호
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• pp.233-240
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• 2019

잎새버섯 안정생산을 위하여 배지의 pH를 적정하게 조절할 수 있는 방법을 개발하고자 유기산을 이용한 pH 조절 및 적정 첨가농도를 구명하기 위하여 수행하였다. 혼합배지에 4종의 유기산(구연산, 호박산, 사과산, 주석산)를 5수준(0.5, 1, 1.5, 2, 2.5, 3%)으로 처리하여 균사생장정도를 측정한 결과 유기산 0.5% 수준에서 균사생장이 빨랐으며, 그 중에서도 호박산이 가장 우수하였다. 유기산의 첨가농도가 높을수록 혼합배지의 pH는 낮아지는 경향으로 배양기간 경과에 따라 대조구의 pH는 서서히 낮아지는 경향을 보인 반면 유기산 처리구는 유지되는 경향이었다. 발이율은 0.5%의 농도에서 호박산이 95%, 구연산 92.5%, 사과산과 주석산 80%로 대조구의 60%보다 우수하였다. 그러나 유기산의 농도가 1% 이상에서는 발이가 지연되거나 억제되는 경향을 보여주었다. 배양기간은 유기산 0.5% 처리구가 30~34일로 대조구의 35일보다 빠른 것으로 나타났으며, 전체 재배기간은 0.5% 호박산이 52일, 0.5%의 구연산과 사과산이 54일, 0.5%의 주석산이 52일로 대조구의 59일보다 빠른 것으로 나타났다. 병당 수량성은 0.5%의 호박산과 구연산 첨가 시 각각 121 g, 107 g으로 가장 우수하였고 대조구의 87.5 g에 비해 21~37% 증수되었다.

• 한국응용과학기술학회지
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• 제9권1호
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• pp.7-13
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• 1992

Lipases catalyzed the transesterification reaction between esters and various primary and secondary alcohols in a 99% organic medium, porcine pancreatic, yeast, mold lipases can vigorously act as catalysts in a number of nearly anhydrous organic solvents. Various transesterification reactions catalyzed by porcine pancreatic lipase in hexane obey Michaelis-Menten kinetics. The dependence of the catalytic activity of the enzyme in organic media on the pH of the aqueous solution from which it was recovered is bell-shaped, with the maximum coinciding with the pH optimum of the enzymatic activity in water. The catalytic power exhibited by the lipases in organic solvents is comparable to that displayed in water. In addition to transesterification, lipases Can catalyze several other processes in organic media.

• 유기물자원화
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• 제9권4호
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• pp.71-80
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• 2001

유기 자연농법 실천농가기술에 대한 객관적인 평가를 위해 이들 농법 실천농가에 대해 실태조사 및 현지 포장에서 작물재배 시험을 실시한 결과, 다음과 같다. 유기 자연농법 실천농가의 토양 화학성은 일반토양보다 pH가 높았으며, 인산, 칼슘함량이 많았고, 특히 유기농법실천농가의 유기물함량이 높았으며, 작물별 소득은 시설고추 > 시설오이 > 과수(배) > 상추 > 벼 순이었다. 유기 자연농법 농가에서 사용되고 있는 농자재는 22~25종이었고 이들 자재의 화학적 특성은 pH가 낮고 비료성분함량이 적었으며 자재에 소요되는 경비는 토양 검정+최소방제보다 3~5배 높았다. 유기 자연농법 재배에 의한 작물 수량은 토양검정 + 최소방제구보다 낮았으며, 농약대체 활용자재 시용에 의한 병충해 방제효과는 적었다. 유기 자연농법구 모두 화학비료를 사용하고 있었으며 시험 후 토양의 화학성은 토양검정구보다 유기 자연농법구에서 가축분퇴비 시용에 의해 유기물 및 인산, 칼리, 석회 함량이 높았다.

• 환경위생공학
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• 제22권1호
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• pp.17-27
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• 2007

This study was conducted the adsorption experiment way of organic wastewater (BOD, COD, TOC, T-N, T-P) by changing the carbonization temperature and the size of adsorbent to examine the adsorption capacity of Korean traditional charcoal which has similar characteristics to activated carbon of organic pollutants. Also, it was performed the basic experiment for pH and inorganic materials. As a result of observing Korean traditional charcoal with has the greatest inorganic contents which are the important factor of chemical adsorption. As the carbonization temperature was better high temperature charcoal than law temperature charcoal to adsorption capacity of pollutant and as the particle was minute (D size : $3.35mm{\sim}2.0mm$), it was most effective. The result of adsorption experiment of organic wastewater show that the elimination ratio of pollutants by bamboo high temperature charcoal was found as BOD(82.1%), COD(91.7%), TOC(52.4%), T-N(66.6%), T-P(83.2%) and it has most excellent adsorption capacity of organic pollutants.