기존의 폴리아마이드 박막 역삼투 복합막(PA TFC RO Membrane)은 우수한 분리투과특성을 지니고 있으나 내염소성이 상대적으로 낮은 단점을 지니고 있다. 본 연구에서는 이를 해결하기 위하여 표면에 -OH나 -COOH 기가 도입된 다공성 지지체를 제조하고, 그 표면에 폴리아마이드 박막을 형성하여 역삼투 복합막을 제조하였다. 제조된 역삼투막의 구조 및 분리투과 특성은 여러 가지 기기분석 방법과 투과테스트 방법으로 분석하였다. 폴리아마이드 박막을 제조하기 위하여 아민계 단량체로는 메타-페닐렌 디아민(MPD)과 2,6-디아민 톨루엔(2,6-DAT)을 사용하였고, 디엑시드계 단량체로는 트리-메소일 클로라이드(TMC)를 사용하였다. 제조된 복합막의 투과도는 800 psi에서 약 1.0 m3/m2day 이상이었으며 이때 염배제율은 99.0% 이상이었다. 내염소성도 친수성기가 없는 폴리설폰 지지체를 사용한 복합막에 비하여 우수한 것으로 나타났다.

In this article, to predict the wear amount of nano particles in a worn nano composite, computational analysis pre/post-processor were developed using ABAQUS and visual basic programs. The abrasion, which is one of nano particles release scenarios, was applied in the computational analysis. Moreover, reciprocation, which is the abrasion type, was selected and incarnated in abrasion computational analysis. Also, to predict wear amount of nano composite in computational analysis, archard equation was applied and the predicted wear amount was evaluated compare with experimental value. The predicted wear amount of nano composite was increased in accordance with increasing force and was similar to result of experimental value.

Poly (vinylidene fluoride) (PVDF)의 소수성 중공사막 표면에 계면중합하여 복합막을 제조하였다. Piperazine (PIP)과 trimesoyl chloride (TMC)의 농도변화, polyethylene glycol (PEG)의 함량변화에 따라 막을 제조하였으며, 막의 특성평가를 위해 100 ppm의 NaCl, CaSO₄, MgCl₂ 용액과 NaCl과 CaSO₄를 혼합하여 제조한 300 ppm의 공급액에 대한 막의 투과도와 배제율을 알아보고자 하였다. TMC를 사용하여 계면중합하였을 때 막의 투과도와 배제율이 가장 높게 나타났으며, 0.1~1 wt%로 TMC 농도를 변화시켜 가며 실험을 수행한 결과 0.1 wt%일 때 NaCl 100 ppm에 대해 투과도 48.3 LMH (L/m²·hr)와 배제율 59%로 가장 높은 값을 나타내었다. 또한, 투과도를 향상시키기 위해 annealing처리와 piperazine에 PEG를 첨가하여 실험을 수행하였다. 실험결과 처리하지 않은 막에 비해 투과도는 전체적으로 향상되는 모습을 나타냈지만배제율이 감소하는 경향을 나타내었다.

Freeze drying of a porous Cu-Sn alloy with unidirectionally aligned pore channels was accomplished by using a composite powder of CuO-SnO2 and camphene. Camphene slurries with CuO-SnO2 content of 3, 5 and 10 vol% were prepared by mixing with a small amount of dispersant at 50˚C. Freezing of a slurry was done at -25˚C while the growth direction of the camphene was unidirectionally controlled. Pores were generated subsequently by sublimation of the camphene during drying in air for 48 h. The green bodies were hydrogen-reduced at 650˚C and then were sintered at 650˚C and 750˚C for 1 h. XRD analysis revealed that the CuO-SnO2 powder was completely converted to Cu-Sn alloy without any reaction phases. The sintered samples showed large pores with an average size of above 100μm which were aligned parallel to the camphene growth direction. Also, the internal walls of the large pores had relatively small pores. The size of the large pores decreased with increasing CuO-SnO2 content due to the change of the degree of powder rearrangement in the slurry. The size of the small pores decreased with increase of the sintering temperature from 650˚C to 750˚C, while that of the large pores was unchanged. These results suggest that a porous alloy body with aligned large pores can be fabricated by a freeze-drying and hydrogen reduction process using oxide powders.

소비자의 먹거리에 대한 의식수준이 최근 지속적으로 높아짐에 따라서 무독성, 비잔류성의 친환경 해충방제시스템의 개발이 시급한 실정이다. 저장곡물의 해충 방제로는 주로 훈증제를 많이 사용하지만 안정성, 환경파괴, 잔류농약, 중복사용으 로 인한 해충의 내성문제 등이 발생되고 있다. 따라서 최근 소비자에게 보다 안전하 고 환경 친화적인 저장곡물 해충방제 열처리시스템이 개발되어 국내 제분회사 등 에 사용되고 있다. 열처리시스템은 실내 온도를 50℃이상 일정시간(약 24∼48hr) 유지하여 해충, 세균, 설치류 등 유해 생물을 방제하는 것으로 이미 선진국에서는 널리 활용되는 친환경적 차세대 해충방제법이다. 본 연구소는 저곡해충 중 대표적 인 거짓쌀도둑거저리(Tribolium castaneum), 어리쌀바구미(Sitophilus zeamais), 화랑곡나방(Plodia interpunctella), 이질바퀴(Periplaneta americana)를 사용하여 열처리시스템에 훈증(Phosphine), 대기조성(CO2), 규조토를 복합처리하여 방제 시간을 단축하거나 방제 온도를 낮추고자 연구를 진행하였다. 4종 해충 각각에 대해서 상온(25℃) 및 45℃ 조건으로 Phosphine, CO2, 규조토를 각각 처리한 경우 처리농도가 높아짐에 따라서 사멸시간이 단축됨을 확인하였다. 이 경우 상대적 Phosphine과 규조토의 해충 사멸 상승효과가 CO2보다 큰 것으로 나타났다. 또한 거짓쌀도둑거저리에 대해서 열(40, 45℃), Phosphine(20, 50ppm), CO2(2, 5, 10%), 규조토(0.2, 0.5, 1mg/L)를 각각 복합처리시 40℃조건에서는 사멸 시간이 72시간(40℃ 단독처리)에서 3~6시간(40℃+Phosphine+CO2+규조토 복합 처리)으로, 45℃조건에서는 24시간(45℃ 단독처리)에서 1~3시간(45℃+Phosphine +CO2+규조토 복합처리)으로 단축되었다.

본 연구에서는 초임계 CO2 추출법을 이용하여 공정변수가 대두유의 수율에 미치는 영향과 초고압 처리가 초임계 추출에 미치는 영향에 대하여 분석하였다. RSM 실험법을 통한 최적화 실험에서 468.18 bar, 80.23oC, 46.82 g/min의 조건에서 최대값 25.88%를 나타내었다. 초임계 추출법의 최적추출조건에서 초고압 전처리 후 추출 수율은 17.15-23.66%로 전처리 전보다 감소하는 경향을 나타내었다. 462.13MPa, 1분의 추출조건에서 정상점은 최대값으로 24.91%가 예측되었다. 초고압 전처리 후 초임계 추출에서 수율이 증가하지 않은 이유는 초고압 전처리시 입자의 뭉침현상이 일어나 평균입자크기가 증가하여 나타난 현상으로 추론하였다. 결과적으로 초고압 전처리는 초임계 추출 수율 증가에 영향을 미치지 못하는 것을 알 수 있었다. 초임계 CO2 추출법을 이용하여 대두유를 추출할 경우 추출 압력, 유량이 높을수록 추출온도가 낮을수록 더 많은 양의 대두유를 추출할 수 있다.

Metal ions are essential to life. However, some metals such as mercury are harmful, even when present at trace amounts. Toxicity of mercury arises mainly from its oxidizing properties. Ionizing radiation (IR) is an active tool for destruction of cancer ce

Treatment characteristics of benzene were investigated by using a fixed bed reactor system applying a hybrid method over composites of photocatalyst and adsorbent. Various composites were made by mixing photocatalyst with adsorbent, such as activated carbon, activated carbon fiber, and sludge. Performance tests were conducted with benzene concentrations of 1,000～3,000 ppm, Benzene flow rates of 50～100cc/min, and packing weights of 14～24g for the various composite samples. The property of benzene treatment was analyzed concerning BET, SEM, pH, and the conversion efficiency. It was concluded by experimental results that the benzene conversion efficiency of a hybrid method was much higher than that of a photocatalyst only method showing a conversion efficiency range between 13% and 65%. It was also found that the comprehensive feasibility study of the hybrid method would be needed with consideration of various factors including additional expenses.

Porous Ti implant samples were fabricated by the sintering of spherical Ti powders in a high vacuum furnace. To increase their surface area and biocompatibility, anodic oxidation and a hydrothermal treatment were then applied. Electrolytes in a mixture of glycerophosphate and calcium acetate were used for the anodizing treatment. The resulting oxide layer was found to have precipitated in the phase form of anatase TiO2 and nano-scaled hydroxyapatite on the porous Ti implant surface. The porous Ti implant can be modified via an anodic oxidation method and a hydrothermal treatment for the enhancement of the bioactivity, and current multi-surface treatments can be applied for use in a dental implant system.

염색폐수처리를 위하여 피페라진, 메타페닐렌디아미, 트리메소일 클로라이드를 이용하여 계면중합법으로 폴리아마이드계 나노분리막과 폴리아마이드계 역삼투막을 제조하였으며, 이들을 오스모닉스사로부터 구입한 역삼투막의 투과특성과 비교하였다. 이들의 기본 분리투과특성 조사를 위하여 PEG 600, Na2SO4, NaCl 수용액을 이용하였으며, 제조된 분리막들은 전형적인 나노복합막과 저압용 역삼투막의 특성을 나타내었다. 제조된 이들 분리막들을 이용하여 국내 염료 제조업체인 (주)경인양행으로부터 공급된 실제 염색폐수를 처리하였으며, 이때 이들의 분리투과특성을 살펴보았다. 또한 분리막을 이용한 폐수처리 시 발생되는 분리막 오염을 제거하기 위하여 일정시간마다 CIP를 실시하였다. 이때 3종류의 서로 다른 화학세정제를 사용하였으며, 이들의 세척성능을 살펴보았다.

Characteristics of VOC(benzene) treatment were investigated using a fixed bed reactor system over copper base catalyst and photocatalyst/adsorbent blending material. The copper base catalysts were made by using copper nitrate reagent and various support materials such as γ-Al2O3, TiO2. The parametric tests were conducted at the reaction temperature range of 200～400℃, benzene concentration of 1,000～2,000 ppm, and space velocity range of 5,000～10,000 hr-1. The property analyses such as BET, SEM and the removal efficiency(conversion) of VOC were examined. The experimental results showed that the VOC removal efficiency of hybrid method was higher than that of single method. It was also found that the comprehensive feasibility study of hybrid method would need with considering various factors including additional expenses.

This study was performed to obtain the emission characteristics of odor compounds generated from a livestock wastewater treatment process. The sampling of odor compounds was performed twice, on May 9th and June 14th 2006, at 4 and 5 sites in the boundary and source areas, respectively. The odor concentrations obtained from the air dilution sensory test ranged from 10 to 100 in the boundary area. Of the 5 source sites, the odor concentrations found at the pre-treatment building had the highest values, which were 14422 and 20800 for the first and second dates, respectively. To estimate the major odor compounds produced during a live wastewater process, the contributions of 12 odor compounds to the total odor were calculated from the concentration and odor threshold values of each compound. At the pre-treatment building and outlet of the activated carbon tower of the source sites, the contribution of sulfur compounds to the odor was 97%, and at the outlet of the biofilter that of NH₃ was 90%. The order of the contribution to the odor in the boundary area sites was; from highest to lowest: H₂S, C₂H₆S, i-C₅H10O, C₃H₉N, NH₃. The correlation coefficient between the theoretical odor concentration from the odor threshold of 12 odor compounds and that obtained from the air dilution sensory test was 0.73. This result indicated a limit to the correct analysis of the odor concentration obtained from the air dilution sensory test when only 12 odorous compounds at a livestock wastewater treatment process are used. The odor removal efficiency of the deodorization facilities showed that for the activation carbon tower, the odor concentration was reduced to 4% and the contributions of H₂S, C₂H₆S and NH₃, which were estimated to be the major odor compounds, were reduced to 20, 26 and 11%, respectively. With respect to the bio-filter, the removal efficiency of the odor compounds revealed an odor concentration of 0% because the major odor compounds were calculated as negative percentages.

Eye-tracking approach allows us to collect and analyze data for a wide range of measures of eye-movements, to relate these to language processing, and to have insight of language processing (Conklin, Pellicer-Sánchez, and Carrol, 2018). The current study aims to investigate how ESL university students process the sentences with complex noun phrases modified by relative clauses. Two types of sentences with complex noun phrases were examined: complex noun phrases modified by relative clauses located in a sentence subject (syntactic-based processing) and those located in a sentence object (semantic-based processing). In total, 32 EFL university students participated in this study. Fixation count, regression rate, first reading time, and total reading time of areas of interest were examined. The eye-tracking results showed that the participants showed significantly higher regression rates on noun 2 than noun 1 in both types of complex noun phrases. In terms of verb selection, however, the results showed contrasting aspects : noun 1(verb 1 selection) preference in syntactic-based processing whereas noun 2(verb 2 selection) preference in semantic-based processing,