• 보존과학회지
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• 제28권4호
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• pp.395-401
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• 2012

정유 상태의 세신(Asarum sieboldii) 추출물이 유기질 문화재 보존을 위한 천연 살생물제로써의 적합성 여부를 탐색하기 위하여 목재부후균과 궐련벌레에 대한 항진균활성 및 살충활성을 조사하였다. 목재부후균 4종에 대한 세신 정유추출물의 항진균활성($IC_{50}$)을 측정한 결과 $1.50{\sim}2.84{\mu}l/disc$으로 나타났으며, 이 중 L. lepideus에서 활성이 가장 우수하였다. 궐련벌레 성충에서는 50%(v/w)과 100%(v/w)의 농도로 처리했을 때 약 90% 이상의 살충활성을 보였다. 가스크로마토그래피-질량분석기를 이용하여 정유추출물의 성분을 분석한 결과 총 35종의 화학성분이 검출되었으며, 주성분은 methyleugenol(56.32%), eucarvone(11.53%), safrole(5.79%), ${\delta}$-3-carene(2.09%) 순으로 나타났다. 따라서 세신 정유추출물은 목재부후균과 궐련벌레 등 곤충에 의해 야기되는 생물학적 열화로부터 유기질 문화재를 보존할 수 있는 천연 살생물제로써 활용 가능성을 확인하였다.

• 보존과학회지
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• 제26권3호
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• pp.277-294
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• 2010

서산마애삼존불상(국보 제84호)을 이루는 암석은 담회색을 띠는 중립질 흑운모 화강암이며 부분적으로 페그마타이트 및 석영 세맥이 관찰된다. 삼존불이 조각된 암반은 전면에 걸쳐 불규칙적인 불연속면의 발달로 크기와 모양이 다양한 암괴를 형성하고 있으며, 암반 사면의 안정성이 취약한 것으로 나타났다. 훼손도 진단 결과, 수직 및 수평 절리가 밀집된 부분을 중심으로 물리적 풍화와 표면변색에 의해 훼손이 가중된 상태를 보인다. 이를 삼존불의 전체 면적대비 훼손율 42.7%에 비교했을 때, 물리적 풍화는 9.6%, 변색은 33.1%로 변색에서 높은 점유율을 보였다. 초음파 측정 결과, 삼존불은 전반적으로 심한 풍화단계(HW)에 있으며 삼존불에 발달하고 있는 불규칙한 절리계를 따라 약 1,000m/s의 저속도대가 분포하여 구성 암석이 약화된 것을 알 수 있다. 삼존불 보호각 내외부의 상대습도는 사계절 모두 평균 70% 이상을 기록하며, 95% 이상의 고습도 영역에서 높은 빈도수를 나타냈다. 이 고습도 환경은 강수와 함께 암석 표면에 결로를 발생시켜 수분을 공급하며 수분의 침투와 함수율이 높은 균열 및 절리대를 따라 물리적, 화학적, 생물학적 풍화를 진전시키는 것으로 사료된다. 따라서 삼존불의 과학적 보존을 위해 수분문제를 비롯하여 지속적인 보존환경 모니터링을 통한 환경제어 방안이 필요할 것으로 판단된다.

• Animal Bioscience
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• 제35권12호
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• pp.1871-1880
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• 2022

Objective: The primary goal was to identify the effectiveness of chemical or biological additives in delaying the deterioration of early-harvested wilted rye silage after exposure to air. Methods: Rye harvested as a whole plant at the early heading stage was wilted for 24 h. The wilted forage was divided into treatments including sodium diacetate (SDA) at 3 (SDA3) and 6 g/kg (SDA6), Lactobacillus plantarum (LP), L. buchneri (LB), or their equal mixture (LP+LB) at 1×10⁶ colony-forming unit/g fresh matter. Results: After 60 d of conservation in 20-L silos, lactic acid was greater in LP and LP+LB silages than other treatments (102 vs 90.2 g/kg dry matter [DM]). Acetic acid was greatest in SDA6 (32.0 g/kg DM) followed by LB (26.1 g/kg DM) and was lowest in LP treatment (4.73 g/kg DM). Silage pH was lower with microbial inoculation and the lowest and highest values were observed in LP and untreated silages, respectively. After 60 d, neutral detergent fiber concentration was lowest in SDA6 silages, resulting in the greatest in vitro DM digestibility (846 g/kg DM). Aerobic stability was longest in SDA6 (176 h) followed by LB treatment (134 h). Instability after aerobiosis was greatest in LP silages (68 h), about 8 h less than untreated silages. After aerobic exposure, yeast and mold numbers were lowest in SDA6 silages, resulting in DM loss minimization. Exhaustion of acetic acid and lactic acid after aerobic exposure was lowest with SDA6 but greatest with untreated and LP silages. Conclusion: Treatment of early-cut wilted rye forage with SDA at 6 g/kg resulted in silages with higher feeding value and fermentation quality, and substantially delayed deterioration after aerobic exposure, potentially qualifying SDA at this load for promotion of silage quality and delaying aerobic spoilage of early-harvested (low DM) rye forage.

• 한국토양비료학회지
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• 제32권1호
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• pp.84-89
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• 1999

우리나라 시설재배지토양(施設栽培地土壤)에서 채취(採取)된 72개(個) 밭 토양(土壤)에 대해 Jew's mallow(Corchorus olitorius, L.)의 유식물(幼植物)을 이용(利用)하여 토양(土壤)의 미생물성(微生物性) 간역(簡易) 평가방법(評價方法)을 시험(試驗)하였다. 검정토양(檢定土壤)의 이화학성(理化學性) 차이(差異)의 영향(影響)을 적게 하기 위해 각각의 검정토양(檢定土壤)에 이화학성(理化學性)의 문제(問題)가 없는 살균토괴(殺菌土壞)을 공통적(共通的)으로 4배량(倍量) 가(加)하여 혼합(混合)하였다. 이때, 2적(適) 배양(培養)한 혼합토괴(混合土壞)의 미생물성(微生物性)은 혼합전(混合前)의 미생물성(微生物成)을 반영(反影)하고 있다고 가정(假定)하였다. 1포트에 250g의 혼합토(混合土)를 넣고 Jew's mallow (Corchorusd olitorius L.)을 파종(播種)하여 4주간(週間) 재배(栽培)한 후(後)의 지상부(地上部)의 생육상(生育相)으로 부터 토양(土壤)의 미생물성(微生物性)을 평가(評價)한 결과(結果), 72토양내(土壤內) EC가 $5dS\;m^{-1}$ 이상(以上)의 18토양(土壤)에서는 미생물성(微生物性)이 악화(惡化)될 수 있는 가능성(可能性)이 나타났다. 또한 EC가 $5dS\;m^{-1}$ 미만(未滿)일 때도 미생물성(微生物性)이 악화(惡化)될 수 있는 가능성(可能性)이 있는 토양(土壤)이 존재(存在)하는 한편, 미생물성(微生物性)이 양호(良好)한 토양(土壤)이 존재(存在)할 가능성(可能性)도 보였다. 이 방법(方法)은 Bioassay이므로, 미생물(微生物)의 수(數)나 활성(活性)을 측정(測定)할 필요(必要)는 없다.

• 상하수도학회지
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• 제22권5호
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• pp.551-559
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• 2008

An experimental study was carried out to evaluate the potential of flotation process for the secondary clarifier of an activated sludge process. Flotation techniques, applied in this study, include electrofloation (EF) which generated fine bubbles smaller than $35{\mu}m$ in average and diffuser flotation (DF) which generated fine bubbles smaller than $55{\mu}m$ in average. The batch experiments were done with activated sludge displaying various characteristics. It was shown that the efficiency of solids/liquid separation was reduced as the diluted sludge volume index ($DSVI_{30}$) of activated sludge increased. The dependency, however, gradually decreased as the gas to solids (G/S) ratio increased. Thickening efficiency of EF was more than 2~10 times and DF process was more than 1.5~5 times as compared with gravity sedimentation (GS). Stable sludge blanket was maintained regardless of sludge settleability when the G/S ratio was 0.019 in the EF. On the other hand, Serious deterioration in the sludge blanket was observed in the DF depends on G/S ratio and sludge settleability. And For EF and DF, the suspended solids concentration of effluent was not nearly influenced on settleability of activated sludge and more clear than GS. A biological nutrient removal (BNR) process, combined with EF as a secondary clarifier was operated for three months. The mean MLSS (mixed liquid suspended solids) concentration in the reactor and mean solids concentration of return sludge were estimated to be 5,340 mg/L and 16,770 mg/L, respectively. The water quality of effluent was considerably stable and low value was accomplished, that was, standard suspended solids concentration $0.07{\pm}0.51mg/L$ and standard turbidity $1.44{\pm}0.56NTU$. The EF could be applicable for enhancement of efficiency of activated sludge system as well as improvement of the water quality of effluent.

• Journal of Applied Biological Chemistry
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• 제57권4호
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• pp.331-336
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• 2014

본 연구에서는 최근 산림소득작물로 재배면적이 급증하고 있는 오미자를 대상으로 일반 농경지와 산림농업지에 시비된 식물영양성분의 행방과 유출부하량을 비교 평가하여 환경친화형 산림농업 시스템을 정착하는데 필요한 기초자료를 제공하고자 하였다. 표토 침식 및 식물영양물질의 유출에 더 민감함을 보여주는 지표로 활용되는 유출계수가 일반 농경지 시험구보다 산림농업 시험구에서 더 높게 나타났다. 일반 농경지 시험구와 산림농업 시험구에서 강우-유출에 의한 총질소와 총인의 유출부하량을 평가한 결과, 산림농업 시험구에서 식물영양성분의 손실로 인한 인근 수권 생태계에 끼치는 영향은 미미할 것으로 나타났다. 그러나, 산림농업을 위한 농경지 조성 초기에 식생으로 인한 토양 피복도 부족과 토양구조 불안정으로 인행 상당량의 토사유출이 발생할 수 있는 것으로 나타났다. 따라서, 산림농업을 위한 농경지 조성 초기 단계에는 토양의 유실감수성을 고려한 테라스 및 승수로 등 토양유실 방지대책이 고려되어야 할 것이다.

• 한국환경과학회지
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• 제24권12호
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• pp.1551-1558
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• 2015

In Korea, many drinking water treatment plants (DWTPs) have introduced and are going to introduce biological activated carbon (BAC) process to treated dissolved organic matter (DOM) in water which are difficult to control by conventional water treatment processes. Even though more decade have passed since introduced BAC in Korea, most of BAC operating method was followed to the modified sand filter operating manuals. In case of BAC backwashing, many DWTPs set the periods of backwashing about 3~5 days. In this study, we have collected data to set the proper BAC backwashing periods from both pilot-plant and real DWTPs. We had measured heterotrophic plate count (HPC), turbidity, water temperature, dissolved organic carbon (DOC) and headloss from just after backwashing to the next backwashing time for two years. Considering water quality factors, the BAC run time from backwashing to the next backwashing could extend more 30 days without water quality deterioration if the head loss do not reach the limited level which depends on each BAC facilities' condition. It means the BAC treated water could be saved in the proportion of extended the backwashing period to the existing backwashing period.

• 보존과학연구
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• 통권31호
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• pp.79-88
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• 2010

Paper cultural heritages experience chemical and physical deterioration due to various factors including preservation environments and the property of paper materials1). Thus, it is important to develop optimal preservation and restoration methods for the damaged paper cultural heritages. Currently, lining is a popular treatment for the restoration of paper cultural heritages in Korea. Since lining paper is a layer of paper directly attached to the inside of cultural heritages for protection, understanding of the preservation properties of lining paper is primarily needed in order to devise the better preservation methods. The main material of lining paper is the paper mulberry, but additives such as chalk and white clay is sometimes used to enhance the preservation properties of lining paper. To date, the properties of the functional lining paper containing these additives have been not fully understood yet. In this study, dry heating aging at $105^{\circ}C$ and biological aging by the Aspergillus versicolor and Penicillium polonicum for the lining paper, which is made from paper mulberry and the chalk, are carried out to evaluate changes in their preservation properties by these aging factors. As a result, it is found that the functional lining paper containing 25.1% of chalk can control the growth of fungi, while the paper containing 32.7% of chalk do not show any protection effect. However, the functional lining paper added by chalk is more aged than the lining paper made from paper mulberry by dry heating accelerated aging.

• 보존과학연구
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• 통권34호
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• pp.110-122
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• 2013

정선 정암사 수마노탑의 부재는 탄산염암 중에서 돌로마이트이다. 이 탑은 전면에 걸쳐 백화에 의한 화학적 풍화가 진행되고 있고 기단부와 5층 이상의 옥개에서 부재간의 이격이 관찰되고 있다. 또한 부재 이격사이로 생물학적 풍화가 진행되고 있으며 3,5,6,7층 옥개에서 이탈부재가 관찰된다. 건 습식세척으로 생물과 백화일부를 제거하고, 스팀세척으로 잔여백화를 제거하였으며 기단부의 녹흔은 옥살산을 사용한 습포법으로 제거하였다. 이탈부재는 L-30과 Por-rok을 사용하여 고정시켰고, 기단부와 5층 이상의 옥개상부는 Por-rok을 사용하여 방수처리 하였다. 시공 후 방수처리한 구간에서는 백화현상이 나타나는 정도가 미약한것을 확인할 수 있었으므로 방수효과와 동시에 백화저감에도 효과가 있는 것으로 판단된다.

• Computers and Concrete
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• 제19권4호
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• pp.413-417
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• 2017

Concrete is a material popularly used in construction. Due to the load-bearing and external environmental factors during utilization or manufacturing, its surface is prone to flaws, such as crack and leak. To repair these superficial defects and ultimately and avoid the deterioration of the concrete's durability, numerous concrete surface protective coatings and crack repair products have been developed. Currently, studies are endeavoring to exploit the mineralization property of microbial strains for repairing concrete cracks be the repairing material for crack rehabilitation. This research aims to use bacteria, specifically B. pasteurii, in crack rehabilitation to enhance the flexural and compression strength of the repaired concrete. Serial tests at various bacterial concentrations and the same $Urea-CaCl_2$ medium concentration of 70% for crack rehabilitation were executed. The results prove that the higher the concentration of the bacterial broth, the greater the amount of calcium carbonate precipitate was induced, while using B. pasteurii broth was for crack rehabilitation. The flexural and compression strengths of the repaired concrete test samples were the greatest at 100% bacterial concentration. Compared to the control group (bacterial concentration of 0%), the flexural strength had increased by 32.58% for 1-mm crack samples and 51.01% for 2-mm crack samples, and the compression strength had increased by 28.58% and 23.85%, respectively. From the SEM and XRD test results, a greater quantity of rectangular and polygonal crystals was also found in samples with high bacterial concentrations. These tests all confirm that using bacteria in crack rehabilitation can increase the flexural and compression strength of the repaired concrete.