“Chamgreen” was a domestically developed rye (Secale cereal L.) cultivar in South Korea, known for its quick heading, cold resistance, and abundant yield of forage. The heading date of cv. 'Chamgreen' averaged April 17th, which was 4 days earlier than the standard cv. 'Gogu'. In the early harvesting stage, the plant height reached an average of 119 cm, 7 cm taller than the standard cv. 'Gogu', and the number of spikes per ㎡ was 865, slightly less than cv. 'Gogu's 897. Resistance to cold and powdery mildow remained consistent across four regions nationwide over three years, with an average rating of 0, matching cv. 'Gogu'. Lodging resistance was also rated at 2, equivalent to cv. 'Gogu'. The dry matter yield of cv. 'Chamgreen' was 9.1 tons per hectare, 15% higher than cv. 'Gogu's 7.9 tons. Although the protein content in cv. 'Chamgreen' was 13.5%, 1.6% lower than cv. 'Gogu', the total digestible nutrients (TDN) content was 5.81 tons per hectare, 20% higher than cv. 'Gogu'. Due to its strong cold resistance, cv. 'Chamgreen' allows for winter cultivation through double cropping and rotation systems in various regions across the country.

PURPOSES : In this study, experimental findings regarding the frost resistance of concrete incorporated with mineral admixtures such as fly ash (FA) and ground granulated blast-furnace slag (SG) are presented. METHODS : To evaluate the performance of the abovementioned concretes under repeated freezing and thawing environments, based on the ASTM C 666 standard, the relative dynamic modulus of elasticity and mass ratio measurements are performed regularly. Furthermore, based on the ASTM C 672 standard, the concretes are exposed to 4% CaCl2 and NaCl salt solutions along with repeated 50 cycles of freezing and thawing. Subsequently, the scaling resistance is evaluated based on the scaled-off mass content and visual examination. RESULTS : SG is less effective in enhancing the scaling resistance of concrete compared with FA. However, the concrete incorporated with SG is more resistant to repeated freeze-thaw actions compared with OPC concrete. Meanwhile, compared with OPC concrete, the concrete incorporated with FA indicates a similar performance in terms of scaling resistance and better resistance against repeated freeze-thaw actions. CONCLUSIONS : The frost resistance of concrete depends significantly on the types of mineral admixtures used in concrete. This emphasizes the importance of selecting the appropriate binder to achieve durable concrete pavements in cold climate regions.

A Catholic school is a school that spreads religious ideology to students by combining religious education with regular school curriculum. But, most Catholic schools do not have a separate liturgical space, mass is performed in multipurpose spaces such as auditoriums, and are exposed to severe acoustic defects due to the very aging facilities and lack of sound performance suitable for the liturgical space. So, in this study, an improvement plan was proposed using sound simulation after identifying acoustic defects through field measurements in the liturgical space of Haeseong High School in Jeonju. Also, hearing experiment using Acoustic Psychological Analysis was conducted to identify changes in subjective responses felt by students as they improved their acoustic performance. The results of study, before and after sound performance improvement sound pressure level (SPL500Hz) was 64.8dB at 66.7dB, the weighted sound level (SPLdB(A)) was 67.9dB(A) at 75.8dB(A), reverberation time (RT500Hz) was 2.04sec at 2.52sec, definition (D50,500Hz) was 40.2% at 33.5%, clarity (C80.500Hz) was –0.8dB at –1.18dB, and RASTI was 57.7% at 49.2% was evaluated. In addition, the amount of improvement in subjective responses before and after sound performance through psycho-acoustic experiment decreased by “Reverberation” -17.0%, “Loudness” -11.3% and increased by “Clear” 21.3%, “Vivid” 21.3%, “Intimacy” 12.4%, “Warmth” 14.3%, “Stability” 19.3%, “Godliness” 18.8%. Therefore, after improving sound performance, Haesung High School's liturgical space improved satisfaction with subjective sound performance felt by students and teachers to ensure sound performance suitable for the liturgical space.

Industrial wastewater often contains a number of recalcitrant organic contaminants. These contaminants are hardly degradable by biological wastewater treatment processes, which requires a more powerful treatment method based on chemical oxidation. Advanced oxidation technology (AOT) has been extensively studied for the treatment of nonbiodegradable organics in water and wastewater. Among different AOTs developed up to date, ozonation and the Fenton process are the representative technologies that widely used in the field. Based on the traditional ozonation and the Fenton process, several modified processes have been also developed to accelerate the production of reactive radicals. This article reviews the chemistry of ozonation and the Fenton process as well as the cases of application of these two AOTs to industrial wastewater treatment. In addition, research needs to improve the cost efficiency of ozonation and the Fenton process were discussed.

PURPOSES : In this experimental study, the resistance of blended cement concrete containing air-cooled slag (AS) and water-cooled slag (WS) to freeze–thaw action was investigated. For comparison, the durable performance of ordinary Portland cement (OPC) concrete exposed to a similar damage environment was also evaluated. METHODS : Based on the ASTM C 666 standard, the relative dynamic modulus of elasticity, mass ratio, surface electric resistivity, and compressive strength of blended cement concrete specimens were periodically measured and compared with those of OPC concrete to evaluate the durability of concrete exposed to the freezing-thawing environment. In addition, microstructural characteristics of deteriorated concrete parts were evaluated using scanning electron microscopy (SEM) and energy dispersive spectroscopy techniques to detect products formed by freeze–thaw action. RESULTS : It was found that the resistance of blended cement concrete containing AS and WS to freeze–thaw action was significantly better than that of OPC concrete. Furthermore, the SEM results revealed the frost damage of OPC concrete, owing to the formation of thaumasite. CONCLUSIONS : The application of AS in concrete can effectively improve the durability of concrete, particularly in freeze–thaw environments.

효과적인 물환경관리계획을 수립하기 위해서는 다양한 기원의 유기물이 난분해성 유기물 농도 증가에 영향을 줄 수 있는지 여부를 파악하는 것이 중요하다. 특히 상당량의 광합성 산물은 식물플랑크톤에 의해 매일 생성되고 있지만, 이들이 수계 내 난분해성 유기물에 기여하는지에 대한 정보는 부족하다. 본 연구에서는 13C 및 15N 추적자 첨가 실험을 통해 조류기원 유기물이 생분해 (60일, 암배양) 및 산화제 (과망간산칼륨) 처리 후 분해되지 않고 잔존하는지 여부를 확인하였다. 생분해 실험 결과 광합성을 통해 생성된 총 유기탄소 (TO13C), 입자성 유기탄소 (PO13C), 입자성 질소 (P15N)는 각각 26%, 20%, 17%가 비 생분해성 유기물로 잔존하였다. 또한 상당량의 PO13C가 과망간산칼륨에 의해 산화되지 않고 잔존하였다 (초기: 12%, 60일 암배양 후: 38%). 이는 미생물에 의해 사용된 후 남아있는 조류 기원 유기물이 난분해성 유기물에 기여할 수 있음을 의미 한다. 또한 미생물에 의해 변형된 조류기원 유기물의 양은 COD 산화율 및 유기물 지표 간 격차에 영향을 줄 것으로 사료된다.

The slow diffusion of pollutants to the surface of electrodes has limited the contact between OH radicals and micropollutants in electro-oxidation processes. In this study, conductive hollow fiber membrane (CHF) made with multi-walled carbon nanotube (CHF) was fabricated and operated with flow-through system. During the electro-oxidation of three micropollutants, a conventional flow-by reactor showed less than 60% of removals at the hydraulic retention time (HRT) of 30 minutes, while flow-through operation could achieve complete removal for all tested micropollutants at the same HRT. Moreover, the flow-through system exhibited complete removals even at the HRT of 1 minutes, while that of flow-by system were less than 10 %.

최근 국내외적으로 이상기후로 인한 여름철 폭우, 겨울철 잦은 폭설로 이어지고 있다. 이로 인해 겨울 철 도로의 결빙을 방지하기 위하여 염화물계 제설제가 많이 사용되고 있다. 그에 따른 피해도 증가하고 있는 추세이다. 제설제는 차량부식, 도로훼손, 환경오염은 물론 호흡기질환과 피부병유발 등 환경과 인체의 건강을 해 치고 있다. 또한 날씨가 풀리면서 눈과 함께 녹아 하천으로 유입될 경우 생태계에 영향을 주는 것을 비롯 해 토양에 고농도의 염류로 쌓여 식물잎의 황화나 괴사, 조기 낙엽, 병충해 저항력 저하 등을 발생시킨다. 뿐만 아니라 도로의 지뢰 ʻ포트홀ʼ, 즉 도로에 움푹 패인 구멍 역시 제설제가 주범인 것으로 알려져 눈에 녹으면서 소금물로 변한 염화칼슘이 아스팔트의 취약한 부분을 파고들면서 구멍이 생겨 사고 위험을 높이 고 있다. 더욱이 염화물계 제설제는 교량 등 콘크리트 또는 강재구조물 부식의 원인이 되고 있다. 따라서, 본 연구에서는 재생 폴리에틸렌과 무기질 섬유상 재료 및 보조제를 이용하여 폐자원의 자원화 와 더불어 동절기 결빙 방지를 위해 사용되는 제설제에 대한 저항성을 향상시키는 내염해성 아스팔트 콘 크리트 개발을 목적으로 하였다. 공용성등급이 76-22 이상으로 나왔으며, 개질 아스팔트 품질기준에 모 두 적합한 것으로 나타났다. 이는, 개질제에 포함된 화합물이 아스팔트 바인더와 상호작용하여 탄성 계수 및 고온 등급을 증가시킨 것으로 판단된다. 이를 근거로 추후 아스팔트 PG등급에 따른 혼합물의 물성을 평가할 예정이다.

본 연구는 압연공정에서 발생하는 폐수 중에 함유되어있는 난분해성 COD 물질을 80μm 두께의 극세사 형태로 제조된 Cu-Zn 금속합금의 산화 작용으로 인하여 발생하는 OH 라디칼을 이용하여 처리하는 방법에 관한 기초 연구이다. OH 라디칼은 유기화합물(RH) 속에 포함된 수소를 수소추출반응(H Abstraction) 또는 탄소와 탄소(C-C)의 불포화 결합에 첨가됨으로써 빠르고 비 선택적인 반응을 수행하는 것으로 알려진 것처럼 난 분해성 유기화합물의 처리에 효과적인 것으로 나타났다. 금속합금 반응 물질은 극세사 형태로 표면적이 넓어서 1회 처리만으로도 수용액의 pH를 평형에 도달하게 하여서 반응 효율성이 높은 것으로 나타났다. COD처리 효율은 중성 pH에 가까운 pH 7, pH 6에서 최고치를 보였으며 산성분위기인 pH 5이하 및 알칼리성 분위기인 pH 8이상에서는 낮은 효율을 보였다. 실제 압연 폐수의 응집 침전을 이용한 COD 처리에서도 redox 반응장치의 유무에 따라 2배 이상의 처리효율의 차이를 보였다.

The purpose of this study is to get basic data for the application of coagulants for treating an industrial wastewater containing NBD COD. The NBD COD concentration of the target wastewater was calculated to be 61 mg/L, which was about 72% of the first stage treated water, and this shows that there must be advanced wastewater treatment process. When Alum(8%) was injected in raw the water, 150ppm was the best dosage and 41% CODmn removal efficiency was obtained. When Alum(8%) was injected in the discharge water, 150ppm was the best dosage, and 19% CODmn removal efficiency was obtained. When powdered activated carbon was injected, 40ppm was the best dosage, 26% CODmn removal efficiency was obtained. The method of injecting Alum(8%) in the discharge water was suitable, when the effluent exceeds the water quality standard by 20%, and the method of injecting the powdered activated carbon was suitable, when the effluent exceeds the water quality standard by 20~40%.

난분해성 유기화합물의 일종인 염화 방향족화합물은 냉각제, 소화제, 페인트, 용매, 플라스틱류, 유압제, 제초제, 농약, 그리고 화학합성에 필요한 전구물질 등에 널리 사용된다. 이들은 친지질 특성을 가지므로 생물체의 세포막에 쉽게 흡착되며 먹이사슬에 의한 생물학적 농축과정을 통해 인간을 포함하는 각종 생물체에 축적된다. 그 결과 생물체의 세포막 구조가 변화되고 기능이 저해될 뿐더러 암과 돌연변이를 유발하고 「환경호르몬」