본 연구에서는 고투과성 및 높은 염 제거율을 가지는 역삼투막의 성능향상을 위하여 다양한 첨가제 및 계면중합 시 경화 온도 및 시간에 따른 특성평가에 대한 연구가 수행되었다. 첨가제가 없는 막과 첨가제를 첨가한 막의 모폴로지는 모 두 “ridge-and-valley” 구조를 나타내어, 폴리아미드 층이 다공성 지지층 표면에 성공적으로 중합되었음을 확인하였다. 또한 2-Ethyl-1,3-hexanediol (EHD) 첨가함으로써 향상된 친수성과 수투과율 가졌으며, 이는 접촉각 측정을 통해서 확인되었다. 최 종적으로 97.78%와 98.7%의 NaCl 및 MgSO4 제거율과 3.31 L/(m2⋅h⋅bar)의 높은 수투과율을 가진 고투과성 계면중합막을 제조하였다.

PURPOSES : This study was conducted to evaluate the physical properties of the RAP 50 asphalt mixture containing polymer modified rejuvenator and warm-mix additive to improve the recycling rate of RAP and reduce CO2 emission. METHODS : Mix design of Polymer Modified Warm-mix Asphalt Mixture(RAP 50), and Hot Mix Asphalt Mixture(RAP 30) were produced and the properties of asphalt mixture such as Marshall Stability, ITS, Deformation Strength, TSR, and Dynamic Stability were compared between the two asphalt mixtures. RESULTS : The RAP 50 asphalt mixture showed superior or similar performances compared to the RAP 30 asphalt mixture in all the tests conducted. The results of the Marshall stability and dynamic stability in particular were 13,045N and 3,826 pass/mm, which were 11.37% and 76.7% greater than the RAP 30 asphalt mixture, which indicated that high plastic deformation resistance may be expected. CONCLUSIONS : The results obtained from laboratory tests on the two types of mixtures indicated that the use of polymer modified rejuvenator and warm-mix additive not only allows to increase the proportion of RAP but also improves its properties under lower temperature condition than RAP 30 asphalt mixture. Additionally, it was confirmed that plastic deformation resistance was high and moisture resistance and crack resistance were improved for a RAP 50 asphalt mixture.

This study aimed to investigate the effects of amino acid complex additives, such as protected vitamin C (VC) or detoxified sulfur (DS), on the growth and metabolism of Hanwoo cattle under high-temperature conditions. Accordingly, farms in Temperature-Humidity Index (THI) regions ranging from 78 to 89 for over 100 days were selected. The experimental groups were control, T1 (lysine + methionine + VC, 50 g/head/day), and T2 (lysine + methionine + DS, 50 g/head/day) with 70, 77, and 71 animals each. The range of the THI for 115 days was 78-89, and this occurred in most of the experiment days. The results showed that there was no significant difference in rectal temperature among the groups. The body weight increased to 786.4 and 809.0kg in the T1 and T2 groups, respectively, compared to the control group (p<0.05). Linoleic acid showed a high result of 2.01% in the T1 group compared to the control group (p<0.05). Unsaturated fatty acids were higher at 55.70 and 56.54% in the T1 and T2 groups, respectively, compared to the control group (p<0.05), and the omega 6/3 ratio was reduced to 20.10% (p<0.05). These findings indicate that T1 has a positive impact on growth, meat quality, and fatty acid composition compared to the control group. In conclusion, amino acid complex with VC improved the body weight of Hanwoo steers and the unsaturated fatty acids and essential amino acids of their meat; however, further research is needed to clarify this impact on carcass performance.

본 연구는 수분함량과 미생물 첨가제가 알팔파 사일리지의 발효특성과 사료가치에 미치는 영향을 알아보기 위해 수행되었다. 알팔파는 개화 10% 시기에서 수확되었으며 수분 함량(M60, M50, M40 및 M30)이 60, 50, 40 및 30%일 때 각각 이용하였다. 1500g을 샘플링한 후, 증류수 10mL을 첨가한 미첨가구(NAD)와 Lactococcus lactis 와 Pediococcus pentosaceus의 혼합물을 증류수(0.1g/10mL)에 1.5 x 1010cfu/g 농도로 희석한 후 접종한 미생물 균주 첨가구(ADD)를 3개월 및 6개월 발효하였다. 수분 및 미생물 첨가제에 따른 연평균 알팔파의 조단백, 중성세제 불용성 섬유 및 산성세제 불용성 섬유에서 차이가 없었다(p>0.05). 모든 발효기간에서 pH는 ADD의 M40에서 가장 낮았다(p<0.05). NAD 처리구에서는 젖산이 M50에서 가장 높았고(p<0.05), ADD 처리군에서는 M40 시험구에서 젖산이 가장 높았다(p<0.05). NAD와 ADD의 M60은 젖산 함량이 다른 수분 함량들에 비해 가장 낮으며(p<0.05) 낙산이 유일하게 검출되었다. 미생물군집의 상대적 풍부도는 ADD 처리구의 M40과 M50에서 Homo LAB (Enterococcus, Lactiplantibacillus, Lacticaseibacillus, Lactococcus, Pediococcus)의 비율이 가장 높았고, Clostridium은 M60에서 가장 높았다.

In this study, we analyzed the changes in concentrations of volatile fatty acids (VFA), phenols, and indoles, as well as odor contribution in pig slurry. The pig slurry was stored for approximately two months after the manure excretion of pigs which had been fed 3% level of peat moss additive. The investigation was carried out through lab-scale experiments simulating slurry pit conditions within pig house. Throughout the storage period, the concentration of VFA exhibited a tendency to be 11%-32% higher in the pig manure treated with peat moss as compared to the control group. From a concentration perspective, phenol and acetic acid accounted for the majority of the total odor compounds produced during the pig slurry storage period. However, their significance diminished when the concentration of odoros compounds are converted into odor activity value and odor contribution. Despite the odor reduction effect of the ammonia (NH3) adsorption by peat moss, if it cannot effectively reduce the high odor-contributing compounds such as indoles and p-cresol, the sole use of peat moss may not be considered an effective means of mitigating odors produced by pig slurry. According to this study, indoles, p-cresol, skatole, and valeric acid were consistently revealed as major odor-contributing substances during the two-month storage of pig slurry. Therefore, a comprehensive odor mitigation methodology should be proposed, taking into consideration the odor generation characteristics (including temporal concentration and odor contribution) of pig slurry-derived odors during storage.

목적 : 최근 전자기기의 발달로 인해 근거리 작업이 증가하고 있으며, 이로 인해 안 건강에 대한 우려가 증가함 에 따라 청광 차단에 대한 관심이 증가하고 있다. 방법 : 유해 광선 차단이 가능한 기능성 콘택트렌즈 소재 개발을 위해 reactive yellow 86을 안료 중합체에, 그리고 propyl gallate를 실리콘 하이드로겔 소재에 첨가제로 각각 사용하여 안 의료용 소프트 콘택트렌즈 제조에 적용하였다. 결과 : propyl gallate의 첨가량에 따라 접촉각이 68.25~42.50˚로 측정되었으며, 습윤성이 향상되는 것으로 나타났다. 또한, 제조된 컬러 소프트 콘택트렌즈는 산소투과성 및 습윤성이 우수함과 동시에 자외선 및 청광 차단 효과를 나타내었다. 결론 : reactive yellow 86 및 propyl gallate가 적용된 컬러 콘택트렌즈의 재료의 경우, 기본적인 안 의료용 하이드로젤 렌즈의 물성을 만족시킴과 동시에 우수한 자외선 및 청광차단 효과를 가지는 것으로 판단된다.

PURPOSES : The process of extracting and recovering an asphalt binder from an asphalt mixture is harmful to the human body and can affect the properties of the asphalt binder owing to the presence of residual solvent quantities. This study was conducted to determine the properties of aged asphalt binders based on rejuvenator content without extracting and recovering the asphalt binders using RAP mortar. METHODS : After extracting and recovering aged binders from waste asphalt, a rejuvenator was added at a certain rate to evaluate the physical and rheological properties of the binder based on the added amount. RESULTS : When the rejuvenator content was greater than necessary, the absolute viscosity was not properly measured owing to the behavior of the rejuvenator. The phase angle was measured to be almost 90°, thus indicating that it acted as a liquid . In addition, the shear strain and nonrecovery compliance also increased significantly. CONCLUSIONS : If an excess rejuvenator quantity was added to the aged binder, the absolute viscosity was not properly measured, the phase angle was measured to be almost 90°, and the shear strain increased significantly. It is also necessary to conduct the same tests on different types of RAPs to ensure that the results of this study are reasonable.

본 연구에서는 미생물 첨가에 따라 거세한우 비육우 분의 이화 학적 특성, 미생물 성상, 가스발생량 및 퇴비 부숙도에 미치는 영 향을 규명하고자 수행하였다. 이상의 결과를 종합하면, 4주 후,미생물 첨가구에서 수분, 유기물, 총질소 함량 및 pH가 낮았으며, 나머지 이화학적 특성에서는 차이가 나타나지 않았다. 유산균과 효모균 수는 증가하였으며, 대장균 수는 감소하였다. 12주 후, 미 생물 첨가구에서 유산균과 고초균 수는 높았으나, 수분, 효모 및 대장균 수는 낮게 낮았다. 하지만 암모니아, 황화수소 발생량과 퇴비 부숙도는 미생물 첨가에 의한 효과가 나타나지 않았다. 따라 서, 거세한우 분에 미생물을 첨가하면 유익균은 증가하고, 병원성 미생물은 감소하여, 비육우의 생산성은 증진될 것으로 사료되지 만, 가스 발생량 및 퇴비 부숙도에 대한 추가적인 연구는 지속적 으로 수행되어야 할 것으로 사료된다.

Excess nitrogen (N) flowing from livestock manure to water systems poses a serious threat to the natural environment. Thus, livestock wastewater management has recently drawn attention to this related field. This study first attempted to obtain the optimal conditions for the further volatilization of NH3 gas generated from pig wastewater by adjusting the amount of injected magnesia (MgO). At 0.8 wt.% of MgO (by pig wastewater weight), the volatility rate of NH3 increased to 75.5% after a day of aeration compared to untreated samples (pig wastewater itself). This phenomenon was attributed to increases in the pH of pig wastewater as MgO dissolved in it, increasing the volatilization efficiency of NH3. The initial pH of pig wastewater was 8.4, and the pH was 9.2 when MgO was added up to 0.8 wt.%. Second, the residual ammonia nitrogen (NH4 +-N) in pig wastewater was removed by precipitation in the form of struvite (NH4MgPO4·6H2O) by adjusting the pH after adding MgO and H3PO4. Struvite produced in the pig wastewater was identified by field emission scanning electron microscopy (FE-SEM) and X-ray diffraction (XRD) analysis. White precipitates began to form at pH 6, and the higher the pH, the lower the concentration of NH4 +-N in pig wastewater. Of the total 86.1% of NH4 +-N removed, 62.4% was achieved at pH 6, which was the highest removal rate. Furthermore, how struvite changes with pH was investigated. Under conditions of pH 11 or higher, the synthesized struvite was completely decomposed. The yield of struvite in the precipitate was determined to be between 68% and 84% through a variety of analyses.

PURPOSES : The purpose of this study was to reduce greenhouse gases and prevent potholes on roads by evaluating the performances of hot and warm mixed asphalt mixtures. METHODS : Quality tests were conducted using an appropriate aggregate ratio of the asphalt mixture. The tests for comparing the warm mixed asphalt mixture are the indirect tensile strength and toughness, Marshall stability and flow, tensile strength ratio, and dynamic immersion test. A performance evaluation was conducted using a mixture that satisfied the quality test results. A performance evaluation test was also conducted using the dynamic modulus and Hamburg wheel tracking test. To analyze the performance based on the amine content, the performance was compared with that of a hot mixed asphalt mixture. RESULTS : All tests for the mixture results satisfied the standard values. The optimal amine content was analyzed through the high and low frequencies of the dynamic modulus test results and stripping inflection point with the final rut depth of the Hamburg wheel tracking test. The dynamic modulus test results demonstrated better crack resistance and plastic deformation when a high amine content ratio was used. The Hamburg wheel-tracking test showed water resistance and plastic deformation resistance. The test results of the Hamburg wheel tracking indicated better deformation resistance and water resistance when a high amine content ratio was used. CONCLUSIONS : The plastic deformation and crack resistance increased with an increase in amine content. Analysis of the comprehensive test revealed that the optimal amine content was between that of additives B(50%) and C(65%). Tests with a granular amine content are planned to confirm the specific components. Also planned are a simplified viscoelastic continuum damage test and a semicircular bending test to evaluate the performance better.

본 연구에서는 채소정식을 위한 정식기에 사용하는 생분해성 포트를 개발하기 위하여 생분해성 첨가제의 비율에 따라 포트의 물성 및 식물의 생장 차이를 구명하였다. 본 실험에 사용된 생분해포트의 주원료는 크라프트지와 신문고지였고, 생분해성 포트는 주 배합비에서 내첨첨가제의 함량을 주원료 대비 각 3%, 5%로 제조하였다. 본 실험에서 8주 육묘 후 포트의 물리적 특성과 첨가제에 따른 변화를 알아보기 위해 포트의 인장강도, 두께, 무게 등을 조사하였다. 생분해성 첨가제가 함유된 포트와 일반 PE포트에 식물 생장도 비교하였다. 2주차에서 5주차에는 매주 배추의 생육조사를 진행했고, 5주차에서 8주차에는 고추생육조사를 진행하였다. 식물의 생장은 뿌리신선중(g), 지상부 시선중(g), 옆 장(cm), 옆 폭(cm)등을 측정하였다. 생분해성 포트에서의 식물 생장은 플라스틱 포트에 비해 생육이 저조하게 나타났다. 생분해성 포트의 무게와 두께는 첨가제 함량에 따라 낮은 상관성을 보였지만, 인장강도의 경우 차이를 보여 내첨제의 비율에 따라 생육에 영향을 미치는 것으로 나타났다. 그러나 첨가제는 무게와 두께에는 영향을 미치지 않아 포트의 생분해 능력에는 영향이 없는 것으로 판단된다. 본 연구는 생분해성 식물 포트 개발의 기초자료가 될 것으로 기대된다.

The purpose of this study is to require countermeasures for alternative energy of diesel combustion engines, which has a serious impact on air pollution when using the quantitative limit of petroleum-based energy and transportation energy. This study attempted to study the usefulness of the oxygen component in fuel as a measure to reduce exhaust emissions from diesel engines used in reality. Dimethoxy methane (DMM), which contains about 42% oxygen in itself, was mixed with diesel and applied to a diesel engine. As a result of the study, it was confirmed that as the oxygen content in the fuel increased, smoke was greatly reduced and NOx increased.