이 연구는 바잘트 섬유시트로 전단보강한 철근콘크리트 보의 전단경간비에 따른 구조물의 구조적 거동을 실험을 통해 확인하였다. 철근콘크리트 보의 전단보강은 무보강, 45도, 90도, U형보강을 변수로 두었으며 전단경간비에 따른 실험결과 U형으로 보강하였을 때 철근콘크리트 보의 전단보강효과가 높음을 확인하였다.

DLC has been attractive as semiconductor materials for solar cell due to its biological friendliness, flexible microstructures, and especially its tunable band gap. In order to fabricate high-efficiency multiband gap solar cell, it is important to control the sp3/ sp2 bonds ratio of DLC film corresponding to optical band gap (Eg). There are many references reporting the relations among the fabrication conditions, Eg, sp3/ sp2, and ID/ IG. However, a more comprehensive database is needed for controllable fabrication. Especially, the quantitative relationship of sp3/ sp2 ratio to Eg of DLC film by PECVD is unclear. In this paper, 36 sets of DLC films were fabricated by RF-PECVD. Characterization methods of XPS, Raman spectroscopy, and IR absorption have been used to determine the sp3/ sp2 ratio of DLC films. UV/visible light absorption method has applied to evaluate Eg. The Eg obtained is in the range 1.45–3.0 eV. Our results agree well with the references. The XPS spectra gives a linear relationship as Eg = − 0.161 (± 0.136) + 26.095 (± 1.704) · {sp3 (XPS)/sp2}, the Raman spectra shows a linear function that Eg = 1.327 (± 0.046) + 0.428 (± 0.036) · (ID/IG), as well as the FTIR analysis demonstrates that Eg = − 0.492 (± 0.093) + 0.464 (± 0.044) · {sp3 (FTIR)/sp2}.

본 연구에서는 열대우림인 브루나이 MDF와 PSF의 주요 수종 (D. aromatic, D. rappa, C. arborescens)을 대상으로 초기 분해 단계의 수종별 질량 감소율과 탄질율의 변화를 파악하였다. 2019년 5월에 총 48개의 고사목 시료 (15 cm×4.8 cm×5 cm)를 산림 지표면에 배치하고 16개월 후 수거하였다. 분해 전 수종별 고사목의 밀도 (g cm-3)는 0.64±0.01 (D. aromatic), 0.60±0.00 (D. rappa), 0.44±0.02 (C. arborescens) 등이었으며, 16개월 동안 수종별 연간 질량 감소율 (%)은 6.37 (D. aromatic), 8.17 (D. rappa), 18.53 (C. arborescens) 등으로 나타났다. 부후등급은 C. arborescens에 서 III등급이 약 25%로 높았으며 흰개미의 분해 흔적이 나타났다. 한편, 16개월 후 탄질율은 D. aromatic과 D. rappa에 서 통계적으로 유의하게 감소하였으나, C. arborescens에서는 감소하는 경향이 유의하지 않았다. 이러한 연구 결과는 열대우림 내 고사목의 초기 분해는 밀도와 같은 수종의 물리적 특성에 따라 차이가 나타날 수 있으며, 주요 분해자의 유형에 따라 탄질율의 변화에도 상대적으로 차이가 있을 수 있음을 시사하는 것이다.

In MBR, extracellular polymeric substance (EPS) is known as an important factor of fouling; soluble EPS (sEPS) affects internal contamination of membrane, and bound EPS (bEPS) affects the formation of the cake layer. The production of EPS changes according to the composition of influent, which affects fouling characteristics. Therefore, in this study, the effects of the F/M ratio on the sEPS concentration, bEPS content, and fouling were evaluated. The effects of F/M ratio on the amount and composition of EPS were confirmed by setting conditions that were very low or higher than the general F/M ratio of MBR, and the fouling occurrence characteristics were evaluated by filtration resistance distribution. As a result, it was found that the sEPS increased significantly with the increase of the F/M ratio. When the substrate was depleted, bEPS content decreased because bEPS was hydrolyzed into BAP and seemed to be used as a substrate. In contrast, when the substrate is sufficient, UAP (utilization-associated products) was rapidly generated in proportion with the consumption of the substrate. UAP has a relatively higher Protein/Carbohydrate ratio (P/C ratio) than BAP, and this means, it has a higher adhesive force to the membrane surface. As a result, UAP seems like causing fouling rather than BAP (biomass-associated products). Therefore, Rf (Resistance of internal contamination) increased rapidly with the increase of UAP, and Rc (Resistance of cake layer) increased with the accumulation of bEPS in proportion, and as a result, the fouling interval was shortened. According to this study, a high F/M ratio leads to an increment in UAP generation and accumulation of bEPS, and by these UAP and bEPS, membrane fouling is promoted.

본 연구에서는 설탕 대체 비율에 따른 알룰로스의 이화학적 특성 변화를 연구하였다. 알룰로스의 설탕 대체비율을 0, 25, 50, 75, 100%로 설정한 후 수분함량, pH, Brix 의 변화를 측정하였다. 설탕 100%를 사용하였을 경우 0.11%로 가장 낮은 수분함량을 나타냈으며, 알룰로스의 함량이 높아질수록 수분함량이 증가하는 경향을 보였다. pH 는 설탕 100%와 알룰로스 100%를 제외하고 알룰로스 대체에 따른 시료간의 유의적 차이는 없었으며, brix는 알룰 로스의 함량이 높아질수록 낮은 값을 보였다. 상대습도에 따른 흡습량의 정도를 측정한 결과, 모든 실험조건에서 알룰로스 함량이 높아질수록 흡습량이 높아졌으며, 상대습도가 높을수록 흡습량의 증가가 더 큰 것으로 나타났다. 상대습도가 높고 알룰로스의 함량이 높을수록 흡습이 일어나 는 기간이 긴 것으로 나타났다. 이러한 알룰로스와 설탕의 혼합 비율에 따른 수분함량 및 흡습량의 자료는 앞으로 제빵 공정에 있어서 최종제품의 품질을 결정할 수 있는 기초자료로서 활용이 가능할 것으로 판단된다.

Heatwaves are one of the most common phenomena originating from changes in the urban thermal environment. They are caused mainly by the evapotranspiration decrease of surface impermeable areas from increases in temperature and reflected heat, leading to a dry urban environment that can deteriorate aspects of everyday life. This study aimed to calculate daily maximum ground surface temperature affecting heatwaves, to quantify the effects of urban thermal environment control through water cycle restoration while validating its feasibility. The maximum surface temperature regression equation according to the impermeable area ratios of urban land cover types was derived. The estimated values from daily maximum ground surface temperature regression equation were compared with actual measured values to validate the calculation method’s feasibility. The land cover classification and derivation of specific parameters were conducted by classifying land cover into buildings, roads, rivers, and lands. Detailed parameters were classified by the river area ratio, land impermeable area ratio, and green area ratio of each land-cover type, with the exception of the rivers, to derive the maximum surface temperature regression equation of each land cover type. The regression equation feasibility assessment showed that the estimated maximum surface temperature values were within the level of significance. The maximum surface temperature decreased by 0.0450˚C when the green area ratio increased by 1% and increased by 0.0321˚C when the impermeable area ratio increased by 1%. It was determined that the surface reduction effect through increases in the green area ratio was 29% higher than the increasing effect of surface temperature due to the impermeable land ratio.

유통 당류(n=124)에서 C4슈가 혼입여부를 확인하기 위하여 탄소동위원소비율(δC), 당조성, 인공감미료를 분석하였다. 탄소동위원소비율 분석 결과, 유통벌꿀(n=23) 중 3 건(13.6%)에서 C4슈가가 혼입된 것으로 판정되었고 도시 영농으로 제조된 벌꿀(n=23)은 모두 식품공전의 기준에 적합하였다(-26.09– -22.99‰). 사양벌꿀(n=11)의 탄소동위원 소비율 범위는 -14.58에서 -11.52‰로 C4당의 특성을 보였다. 코코넛슈가(n=20)의 δC값은 -25.72에서 15.87‰로 3건에서 C4당류가 혼입된 것으로 판단되었다. 단백질침전 법으로 C4당의 함량을 확인한 결과, 모든 코코넛슈가에서 C4당이 최저 9.5%에서 최고 63.4% 검출되었다. 메이플시럽 (n=12) 중 1건이 AOAC의 메이플 시럽 기준에 부합되지 않았다. CAM 당류인 아가베시럽(n=12)은 -11.42에서 - 10.92‰ 범위로 C4당류와 범위가 겹쳐서 추가 연구가 필요하다. C4당인 사탕수수당(n=10)의 탄소동위원소비율은 -12.60에서 -11.40‰이었고, 옥수수물엿(n=5)은 -11.70에서 -10.93‰이었다. Fructose/glucose 비율 측정 결과, 일부 아가베시럽에서 혼입이 의심되었다(3.2-49.7). 모든 시료에서 인공감미료는 검출되지 않았다.

This study was conducted to find an efficient and economical mixing ratio of deodorant and a isolated microorganism to reduce ammonia in livestock manure compost. In this study, a simple experimental device that can compare the degree of odor reduction by connecting the vial containing the odor generating source and the gas detection tube and leaving it to stand was used. This test method cannot accurately measure ammonia concentration according to the characteristics of the detector tube, but it is an easy method to compare various experimental conditions. The microorganism isolated from pig manure, “Enterococcus casseliflavus” was found to have an effect on ammonia reduction. Surfactant (sodium dodecyl sulfate), mineral A, mineral B, sulfur, persimmon leaves, and glycerin used as a deodorant were mixed with E. casseliflavus NO-2-L to find the optimum mixing ratio. When 20% of deodorants and E. casseliflavus NO-2-L were added to the source of odor alone, the ammonia reduction efficiency of NO-2-L was the highest (66.7%) compared with other deodorants. When a mixture of microorganisms and deodorants were used, the ammonia reduction efficiency was the best when the mixing ratio of the deodorant was 20%. When mineral B and sulfur were added, the ammonia concentration reduction efficiency was the highest at 83.3%.

This study was to evaluate the feed value of whole crop rice silage (WCRS) and to investigate a suitable ratio of the WCRS and concentrate by an analysis of rumen fermentation. A total of 6 treatments were used according to WCRS: concentrate ratio on in vitro rumen fermentation: T1 (100:0), T2 (60:40), T3 (40:60), T4 (20:80), T5 (10:90), and T6 (0:100). The ruminal pH, total gas emission, ammonia nitrogen, and volatile fatty acid (VFA) were determined as fermentation parameters. Total nutrients digestibility trial was conducted by 4 treatments according to WCRS: concentrate ratio at 40:60 (W40), 20:80 (W20), and 10:90 (W10), respectively. Feed value was analyzed according to AOAC (2019) and nutrient digestibility was calculated based on NRC (2001). The levels of crude protein (CP), crude fat, and neutral detergent fiber of the WCRS were 12.29%, 1.67%, and 59.79%, respectively. It was found to be 51.49% as a result of predicting the total digestible nutrient of WCRS using the NRC (2001) model. In vitro rumen fermentation, T4, T5, and T6 treatments showed a greater gas emission and total VFA concentration compared with other treatments (p<0.05). Acetate and acetate to propionate ratio of T4, T5, and T6 were significantly higher than other treatments (p<0.05). There was a significant difference in the level of propionate and butyrate according to the WCRS: concentrate ratio (p<0.05). The digestibility of dry matter and CP was significantly lower in W40 than in other treatments (p<0.05); however, there was no difference in W20 and W10. In conclusion, the 20:80 (WCRS: concentrate) is beneficial for stabilizing the rumen that does not inhibit rumen fermentation and nutrient digestion. This ratio might have a positive effect on the economics of farms as a valuable feed.