• 청정기술
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• 제25권3호
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• pp.223-230
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• 2019

본 연구에서는 강원도 5개 지자체에서 발생된 음식물류 폐기물의 특성을 분석하고 메탄가스 발생량을 평가하였다. 시료는 2017년 7월과 9월에 걸쳐 총 2회 채취하였다. 메탄가스 발생가능량을 평가하기 위하여 BMP (biochemical Methane potential) 시험과 원소조성을 이용한 계산방법을 이용하였다. 음식물류 폐기물의 겉보기밀도는 평균 $0.758{\sim}0.850g\;cm^{-3}$, pH는 4.29 ~ 4.75이었다. 물리적 조성 중 주성분은 채소류가 56.43 ~ 72.81%로 가장 높았고, 과일류는 5.31 ~ 8.95%, 곡물류는 1.60 ~ 18.73%, 어육류는 4.47 ~ 12.11%, 여액은 1.76 ~ 3.64%이었다. 평균 수분함량은 69.30 ~ 75.87%, 가연분함량은 22.50 ~ 27.98%, 회분함량은 1.63 ~ 2.48%를 나타내었다. 또한 $BOD_5$는 $17,690.3{\sim}33,154.9mg\;L^{-1}$, $COD_{Cr}$은 $106,212.3{\sim}128,695.5mg\;L^{-1}$, 그리고 $COD_{Mn}$은 $51,266.1{\sim}63,426.3mg\;L^{-1}$의 범위를 보였고 NaCl 함량은 0.81 ~ 1.17%의 범위를 나타내었다. 원소분석 결과 C, H, O, N, S 함량은 각각 44.87 ~ 48.16%, 7.12 ~ 7.57%, 40.13 ~ 43.78%, 3.22 ~ 4.14%, 그리고 0.00 ~ 0.02%를 나타내었다. 음식물류 폐기물의 VS 단위질량당 메탄수율을 살펴보면 BMP 시험에 의한 메탄가스 발생누적량(${0.303{\sim}0.354m_{CH4}}^3\;{kg_{VS}}^{-1}$)은 원소조성과 생분해율을 반영하여 예측한 결과(${0.294{\sim}0.352m_{CH4}}^3\;{kg_{VS}}^{-1}$)와 큰 차이가 없었다.

• 한국산학기술학회논문지
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• 제17권6호
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• pp.588-597
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• 2016

본 연구는 유기성폐기물의 혼합슬러지를 개량형 단상 혐기성 소화공정에서 각각의 혼합비율에 따른 바이오가스 생산효율 향상에 관한 연구로, 연구에 사용된 유기성폐기물의 종류는 하수 생슬러지, 음폐수 및 가축분뇨이다. BMP test를 통해 잠재적 메탄발생량을 확인한 결과 단일시료의 경우 가축분뇨가 $1.55m^3CN4/kgVS$로 가장 높게 평가되었고, 혼합시료(생슬러지, 음폐수, 가축분뇨)의 경우는 각각의 비율을 50% : 30% : 20%로 하였을 때 $0.43m^3CN4/kgVS$로 가장 높게 나타났다. 반면 실증플랜트에서 혼합슬러지 최적 혼합비율은 생슬러지(68.5) : 음폐수(18.0) : 가축분뇨(13.5)로 나타나 BMP test와 다소 상이한 결과를 보였다. 이는 혼합슬러지 성상변화와 체류시간 등 소화조 운전조건 변화에 기인한 결과로 판단되며, 단상 혐기성 소화조의 바이오가스 생산량이 $2,514m^3/d$, 메탄함량 62.8%로 조사되어 설계능력인 바이오가스 생산량 $2,319m^3/d$ 기준으로 볼 때 최대성능을 발휘하는 것으로 평가되었다. 아울러 본 연구를 통해 혐기성 소화방식에 있어 소화조의 안정적인 운영과 소화효율 측면에서 고효율 방식인 2상 소화방식을 도입하는 것이 유리하나 기존의 단상 소화방식에 있어서도 소화효율 개선 및 성능향상이 가능하다는 것을 알 수 있었다.

• 대한환경공학회지
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• 제39권4호
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• pp.186-193
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• 2017

마이크로웨이브(MW)는 유전가열에 의한 열적, 비열적 그리고 이온성 전도 효과를 가지며 높은 에너지 효율을 보이므로 유기성 폐기물의 가용화에 대해 효과적인 방법이다. 본 연구는 고형물 함량이 높은 우분을 대상으로 MW를 이용하여 가용화 최적 조건을 도출하고 이를 토대로 MW의 유전가열 특성을 향상시키기 위해 화학적 촉매물질인 $H_2SO_4$과 NaCl을 첨가하여 우분의 가용화율과 가용화 방법에 따른 biochemical methane potential (BMP)을 평가하였다. 우분 고형물 농도 12%와 MW 출력 800 W 및 설정온도 $40^{\circ}C$ 조건에서 70.5 mg $SCOD_{increased}/kJ$로 에너지 대비 최대 가용화율을 보여주었으며, 이때의 SCOD 농도는 원시료 대비 53.2% 증가하였다. 가용화 최적 조건에서 화학적 촉매로 $H_2SO_4$를 주입하였을 경우 MW 단독 처리 대비 SCOD 농도는 36% 증가하였으며, NaCl을 주입하였을 경우 22.7% 증가하였다. BMP test에서도 우분 원시료 대비 MW를 이용한 가용화는 메탄 생성량이 6.7%, $H_2SO_4$를 주입한 MW 가용화는 13.3%, NaCl을 주입한 MW 가용화는 11.3% 증가하였다. 따라서 마이크로웨이브는 우분의 가용화 전처리에 효율적인 수단이며, 마이크로웨이브의 가용화 효율을 높이기 위해서는 화학적 촉매를 이용할 필요가 있다.

• Journal of Nutrition and Health
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• 제55권6호
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• pp.617-629
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• 2022

본 연구는 속단으로부터 단일 화합물로 분리한 Hed의 조골세포 활성 효능과 작용 기전 규명을 위해 수행되었다. Hed는 MC3T3-E1 세포의 증식과 ALP 효소 활성을 자극하여 세포외 기질에 인산과 칼슘 이온 침착을 증가시켰다. Hed는 BMP-2/Smad 신호 전달 경로를 활성화하여 Runx2, ALP, OPN 및 ProCOL의 mRNA와 단백질 발현을 유의하게 증가시켜 조골세포의 성숙과 분화를 유도하였다. 따라서 본 연구결과 Hed는 조골세포 활성 효능을 가진 것으로 판단되며 항골다공증 기능성 소재로의 개발 가능성을 확인하였다.

• 상하수도학회지
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• 제28권1호
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• pp.25-32
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• 2014

In order to investigate the effective pretreatment methods in WAS(=waste activated sludge) solubilization, the values of SCOD yield per unit SS (SCOD/gSS.hr) were compared. After the hydrodynamic cavitation with pH of 12.5, SCOD increased to 7800 mg/L, SS decreased to 45 % and the solubilization rate was 29 %. Combination of alkality (pH 12.5) and the cavitation seems to be the optimal condition for sludge solubilization. After the cavitational pretreatment, efficiencies of anaerobic digestion of the unfiltered sludge(the control), raw sludge and pretreated sludge were evaluated with BMP(=biochemical methane potential) tests. For evaluation of the biodegradability characteristics of pretreated sewage sludge, the methane production has been measured for 6 months. The methane production of pretreated sludge increased 1.4 times than that of untreated sludge. The result indicates that the cavitationally pretreated sludge was a better biodegradability substrate in anaerobic condition compared to raw sludge. It is obvious that cavitational pretreatment could enhance not only solubilization but also biodegradability of WAS. In conclusion, cavitational pretreatment of WAS to convert the particulate into soluble portion was shown to be effective in enhancing the digestibility of the WAS.

• Journal of Periodontal and Implant Science
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• 제47권3호
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• pp.182-192
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• 2017

Purpose: Contact and distance osteogenesis occur around all endosseous dental implants. However, the mechanisms underlying these processes have not been fully elucidated. We hypothesized that these processes occur independently of each other. To test this, we used titanium (Ti) tubes to physically separate contact and distance osteogenesis, thus allowing contact osteogenesis to be measured in the absence of possible triggers from distance osteogenesis. Methods: Sandblasted and acid-etched (SLA) and modified SLA (modSLA) implants were used. Both types had been sandblasted with large grit and then etched with acid. The modSLA implants then underwent additional treatment to increase hydrophilicity. The implants were implanted into rabbit tibiae, and half were implanted within Ti tubes. The bone-to-implant contact (BIC) ratio was calculated for each implant. Immunohistochemical analyses of bone morphogenetic protein (BMP)-2 expression and new bone formation (Masson trichrome stain) were performed. Results: The implants outside of Ti tubes were associated with good bone formation along the implant surface. Implantation within a Ti tube significantly reduced the BIC ratio (P<0.001). Compared with the modSLA implants, the SLA implants were associated with significantly higher BIC ratios, regardless of the presence or absence of Ti tubes (P=0.043). In the absence of Ti tubes, the bone adjacent to the implant had areas of new bone formation that expressed BMP-2 at high levels. Conclusions: This study disproved the null hypothesis and suggested that contact osteogenesis is initiated by signals from the old bone that undergoes distance osteogenesis after drilling. This signal may be BMP-2.

• Asian-Australasian Journal of Animal Sciences
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• 제26권6호
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• pp.864-873
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• 2013

In developing countries, biogas energy production is seen as a technology that can provide clean energy in poor regions and reduce pollution caused by animal manure. Laboratories in these countries have little access to advanced gas measuring equipment, which may limit research aimed at improving local adapted biogas production. They may also be unable to produce valid estimates of an international standard that can be used for articles published in international peer-reviewed science journals. This study tested and validated methods for measuring total biogas and methane ($CH_4$) production using batch fermentation and for characterizing the biomass. The biochemical methane potential (BMP) ($CH_4$ NL $kg^{-1}$ VS) of pig manure, cow manure and cellulose determined with the Moller and VDI methods was not significantly different in this test (p>0.05). The biodegradability using a ratio of BMP and theoretical BMP (TBMP) was slightly higher using the Hansen method, but differences were not significant. Degradation rate assessed by methane formation rate showed wide variation within the batch method tested. The first-order kinetics constant k for the cumulative methane production curve was highest when two animal manures were fermented using the VDI 4630 method, indicating that this method was able to reach steady conditions in a shorter time, reducing fermentation duration. In precision tests, the repeatability of the relative standard deviation (RSDr) for all batch methods was very low (4.8 to 8.1%), while the reproducibility of the relative standard deviation (RSDR) varied widely, from 7.3 to 19.8%. In determination of biomethane concentration, the values obtained using the liquid replacement method (LRM) were comparable to those obtained using gas chromatography (GC). This indicates that the LRM method could be used to determine biomethane concentration in biogas in laboratories with limited access to GC.

• 한국지하수토양환경학회지:지하수토양환경
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• 제15권2호
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• pp.40-46
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• 2010

In this study, microwave irradiation, which is reflected by metals, was used to reduce the amount of sewage sludge, and the results were used to verify solubilization efficiency and determine optimum operation conditions. Biogas production and methane content of the gas under optimized conditions were measured with the biochemical methane potential (BMP) test. The sludge was taken from a thickened sludge tank at J sewage treatment plant (JSTP) in Seoul, Korea. For the experiments, 50 mL of sludge was filled in vessels and the vessels were irradiated with the power of 500, 600, 700, and 800W for 2~5 min. In addition, Fe powder was added by 0.01, 0.05, and 0.1 g to compare the efficiency with and without Fe powder. The results confirmed that solubilization efficiency was higher in the presence of Fe powder. The optimum conditions of 0.01 g addition of Fe powder with 800W irradiation for 5 min, yielded nearly 22.95% higher solubilization efficiency than without Fe powder. The BMP tests were carried out using sludge obtained from the experiments carried out under the optimum conditions. As a result, sludge subjected by 800W with 0.01 g of Fe powder for 5 min displayed the highest level of gas production and methane content. Through this study, it could be confirmed that solubilization efficiency increased by addition of Fe powder.

• Journal of Biosystems Engineering
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• 제42권3호
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• pp.155-162
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• 2017

Purpose: The objective of this study was to evaluate the biogas productivity of agricultural by-products (ABPs) based on their proximate composition. Specifically, the effects of proximate composition were investigated, and a new mixing method was developed using various ABPs that are difficult to digest for biogas production. Methods: Experiments were conducted to compare the biogas productivity between a single ABP and a mixture of ABPs that had the same proximate composition as the single ABP. To match the proximate compositions of radish waste and corn distiller's dried grains with solubles (DDGS), mixed ABPs were made from various ABPs. Biogas potential tests (BMP tests) were performed at an organic loading rate (OLR) of 2.5 g VS/L and a feed to microorganism ratio (F/M) of 0.5 under the mesophilic condition. Results: The individual ABPs (radish and corn DDGS) and the mixed ABPs (cabbage waste with skim milk waste, bean-curd waste with skim milk waste, and some others) produced similar amounts of biogas. Conclusions: The new mixing method based on proximate composition can be applied to other ABPs and organic wastes from factories and municipal waste treatment plants to develop renewable energy and effective waste treatment methods.

• Asian-Australasian Journal of Animal Sciences
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• 제26권1호
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• pp.36-42
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• 2013

The average twin lambing rate of Bayanbulak sheep is 2% to 3%. However, a flock of sheep with a close genetic relationship and an average of 2 to 3 lambs per birth has been found recently. To determine the major genes controlling the prolificacy of the flock in the present study, the flock was designated A while 100 normal Bayanbulak sheep were randomly selected to comprise the control flock B. Ligase detection reaction method was applied to detect and analyze the 10 mutational loci of the 3 candidate prolificacy genes including bone morphogenetic protein type I receptors, bone morphogenetic protein 15, and growth differentiation factor 9. The 10 mutational loci are as follows: FecB locus of the BMPR-IB gene; $FecX^I$, $FecX^B$, $FecX^L$, $FecX^H$, $FecX^G$, and $FecX^R$ of the BMP15 gene; and G1, G8, and FecTT of the GDF9 gene. Two mutations including BMPR-IB/FecB and GDF9/G1 were found in Bayanbulak sheep. Independence test results of the two flocks demonstrate that the FecB locus has a significant effect on the lambing number of Bayanbulak sheep. However, the mutation frequency of the G1 locus in GDF9 is very low. Independence test results demonstrate that the GDF9 locus does not have a significant impact on the lambing performance of Bayanbulak sheep. Among the 10 detected loci, BMPR-IB/FecB is the major gene that influences the high lambing rate of Bayanbulak sheep.