In this study, the odor compounds emitted from the field workplaces at the Pohang steel complex were measured using analytical instruments and the olfactory method. In addition, the reduction of odor emissions by pyroligneous liquid was evaluated. The odor samples were obtained from slag pots and dry pits, which refrigerate hot slag, and the target compounds were hydrogen sulfide (H₂S) and ammonia (NH₃). The levels of odor emissions varied with meteorological and operating conditions, but emissions from dry pits were always much higher than those from slag pots. As the concentration of pyroligneous liquid increased, the concentrations of H₂S and the ratios of dilution decreased. Together with this result and the guideline of odor emissions, the increase of pyroligneous liquid (more than 2.5 times) in cooling water was suggested to reduce odor emissions. Actually, the reduced levels of H₂S at the slag pot and the dry pit were observed (70 and 94%, respectively) after the increased amount of pyroligneous liquid. However, in order to determine the optimal amount of pyroligneous liquid for the economical and efficient removal of odor emissions, the system of cooling water has to be improved and more samples are required for a comprehensive analysis.
천연식물소재 및 한약재 추출제재인 식물추출 혼합제재가 인체내에서 니코틴 분해능에 미치는 영향을 FRCFR5 세포주, Xenopus oocyte, 임상 실험을 통하여 검토하였다. 본 실험은 체내에 잔존하는 니코틴이 식물추출 혼합 제재에 의해 무독한 대사산물인 코티닌으로 분해량이 증가되고 동시에 NNK, NNN, NNA 등과 같은 폐암 유발물질인 니트로사민 유도체 생성 경로가 억제될 것이라는 가정을 전제로 실험을 수행하였다. 본 실험 결과에서 볼 수 있듯이 식물추출 혼합 제재에는 니코틴에서 코티닌으로 전환시키는 대사 활성물질이 함유되어 있다는 사실을 알 수 있으나, 실제로 어떤 유효성분들이 관여하는지 그리고 정확한 작용 기작을 규명하기 위해서는 더 많은 분석 및 생화학적 연구가 앞으로수행되어야 할 것이다. 간세포에서 유래된 FRCFR5 세포주 실험 결과, 니코틴과 식물추출 혼합 제재가 첨가된 배지에서 니코틴과 물을 첨가한 배지보다 니코틴에서 코티닌으로 전환능력이 약 2∼3배 높게 나타났으며, 이러한 결과는 Xenopus oocyte에 직접 주사한 경우와 거의 비슷한 양상을 보였다. 임상실험 결과 식물추출 혼합 제재 음료를 음용하고 담배를 피운 실험군이 물을 음용하고 담배를 피운 대조군에 비해 약 2배 정도 높은 코티닌 함량을 나타내었다. 이는 실험군의 소변 중에 계속적으로 다량의 코티닌이 배출되는 것을 의미하며, 식물추출 혼합 제재 섭취시 체내에 존재하는 니코틴이 코티닌으로 지속적이면서 효과적으로 전환되는 것을 말한다. 이상의 생체 내·외 실험에서 알 수 있듯이 식물추출혼합물은 니코틴에서 코티닌 생성을 약 2배정도 증가 시키는 것을 알 수 있었다.
가막사리와 미국가막사리 종자의 발아에 명 암조건과 식물생장조절제(ABA, BA, , IAA) 및 종피가 미치는 영향을 조사하였다. 1. 종피를 파상시킨 종자는 명상태에서는 발아하였으나, 암조건에서는 발아하지 않거나 저조하였다. 2. 종피를 파상시킨 가막사리와 미국 가막사리 종자는 암조건에서는 발아하지 않았으나 와 BA의 처리에 의해 발아가 가능하였다. 3. 미국가막사리 종자의 외피만 제거할 경우 발아되지 않았으나 내피를 제거할 경우에는 높은 발아율을 나타내었다.
This study evaluated the photocatalytic oxidation efficiency of volatile organic compounds by Cu2O -TiO2 under visible-light irradiation. Cu2O-TiO2 was synthesized by an ultrasonic-assisted method. The XRD result indicated successful p-n type photocatalysts. However, no diffraction peaks belonging to TiO2 were observed for the Cu2O-TiO2. The Uv-vis spectra result revealed that the synthesized Cu2O-TiO2 can be activated under visible-light irradiation. The FE-TEM/EDS result showed the formation of synthesized nanocomposites in the commercial P25 TiO2, the undoped TiO2, and Cu2O-TiO2 and componential analysis in the undoped TiO2 and Cu2O-TiO2. The photocatalytic oxidation efficiencies of benzene, toluene, ethylbenzene, and o-xylene with Cu2O-TiO2 were higher than those of P25 TiO2 and undoped TiO2. These results indicate that the prepared Cu2O-TiO2 photocatalyst can be applied effectively to control gaseous BTEX.
본 연구의 목적은 개별적으로 이루어진 형태초점 기법 적용 연구들을 메타분석의 방법을 통하여 종합적으로 살펴보고, 암시적 형태초점 기법과 명시적 형태초점 기법의 효과성을 알아보는 데에 있다. 이를 위해 형태초점 기법의 적용을 독립변인으로 하는 59개의 학술지 논문을 대상으로 메타분석을 실시하였다. 각 연구는 학습자 나이, 처치 기간 및 기능, 어휘, 문법의 종속변인별로 구분하여 효과크기를 분석하였다. 분석 결과 암시적 형태초점 기법의 경우 0.612, 명시적 형태초점 기법의 경우 0.634의 효과크기를 보이며, 두 지도 방법 모두 중간 이상의 효과를 가지는 것을 알 수 있었다. 학습자 나이 및 처치 기간 따른 효과크기는 통계적으로 유의한 차이가 없었으나 명시적 형태초점 기법을 활용한 문법 지도는 언어 기능 지도에 비해 통계적으로 유의미한 수준에서 효과가 큰 것으로 나타났다.
원양어선 제501 오룡호는 황천 중인 베링해에서 조업 후 피항하던 중 개구부를 통한 침수로 인하여 침몰하였으며 많은 선원들이 사망하고 실종되었다. 본 연구에서는 사고선박 침몰사고의 진행상황 별 유동수 영향과 어획물 배치 등을 고려한 선박복원성 계산을 KST-SHIP (선박안전기술공단 선박계산시스템)을 사용하여 수행하고 사고선박의 침몰사고 시의 침수 후 선박복원성을 분석하였다. 먼저 만재출항상태 (Full Load Departure Condition)에서의 사고선박의 비손상 복원성 계산서와 KST-SHIP을 사용한 비손상 선박복원성 계산 결과를 비교하여 검증하고, 사고선박의 출항 시부터 사고 직전까지의 배수량에 따른 비손상 복원성 계산을 수행하여 비손상 복원성을 분석하였다. 또한 사고선박 침몰사고 시의 진행상황 별 침수 후 선박복원성 계산을 수행하여 침수 후 복원성도 분석하였다.
Landfill and incineration tax was introduced in 2018 to reduce waste and promote recycling. However, there is a debate about tax rate. An analysis of the external effects of waste-treatment facilities is necessary, but first, an analysis of direct costs (construction, operation) is compulsory and must be conducted precisely. This study analyzed factors that affect operating cost. Ultimately, an estimation of annual operating cost was achieved by applying a multiple regression analysis to the previously-recorded data from 33 incineration facilities and 199 reclamation facilities. The results showed that incineration operating cost is affected by capacity, capacity utilization rate, and use of electricity. Annual landfill amount, area, and leachate treatment affect landfill operating cost, as well. The coefficient of determination is 0.6 or higher. Significance and collinearity between independent variables is at an acceptable level.
The objective of this study is to analyze a price of environment-friendly and conventional rice with POS data. And we estimate the value of environmentfriendly’s certification with hedonic price model. In case of price level, organic and pesticide-free rice is higher than conventional rice, 22.5% and 10.6%, respectively. In contrast, price variation of conventional rice is higher environmentfriendly rice. The value of organic and pesticide are 839.5 Won and 313.7 Won, respectively. As time goes by, the certification’s value goes down in environmentfriendly rice. In particular, price level and certification’s value of pesticide-free rice is similar with conventional rice. The results of this study show that price of the environment-friendly rice is not higher than expected. Therefore it is necessary to establish a new marketing and promotion strategies for environment-friendly rice.
This study was examined the variation of unit water content and fine aggregate ratio in concrete for nuclear power structure using a large amoung of crushed sand.
This study was investigated the influence of increase in compressive strength according to water reducing ratio. As a result of the analysis, it is determined that compressive strength according to water reducing ratio was increased by increasing the efficiency of cement.
This study was evaluated compressive strength of age 28 days of binary blended concrete according to there type of superplasticizer and there type of w/c. In addition, we are proposed modification prediction model equation that can reflect efficiency of water reducing and influence of binders using Lyse equation to predict the compression strength through the conventional W/C.
Recently, in Seoul there is a growing interest in the L type gutter between the street and the sidewalk because the broken gutter spoils the appearance of the city. The gutter has been viewed as an unimportant attached facility of the road despite an important drainage facility. Also, the gutter lost function by various deterioration actions is becoming hideous objects of streets. Accordingly, many engineers recognized problems about the gutter and tried to seek for solution. In this study, we desired to confirm that the inside of the gutter concrete was not deteriorated even if the surface of the gutter concrete was deteriorated by the de-icing salts. We could obtain thirty core specimens deteriorated by de-icing salts in Seongbuk-gu which is old downtown, has many hills such as Arirang-Hill, Miari-Hill, etc. in Seoul and test compressive strength. It was confirmed that the compressive strength of the gutter concrete follows normal distribution and it is statistically significant 1% level that the population mean of the compressive strength of the gutter concrete is more than 18MPa.
In this paper, was examined the basic properties of mortar using perlite, vermiculite, natural and artificial lightweight aggregate as a part of the basic study for development of lightweight repair mortar.
Environmental problems caused by the occurrence of carbon dioxide are recognized as a critical issue throughout the world. As a result, a measure for the use of cement and improvement of its quality must be sought out. In order to reduce the occurrence of carbon dioxide during the manufacturing process of cement, this study creates an alkali-activated slag cement that utilizes ground granulated blast furnace slag, an industrial by-product, and substitutes metakaolin as an alternative for silica fume to improve the process of manufacturing high-strength concrete and its quality. The study discerns the mechanical characteristics by measuring the flexibility and compressive strength through the mortar matrix and discerns the durability by conducting an acid resistance test and chloride ion penetration resistance test. Also, the study discerns the hydration products through an XRD test. Based on the results of such tests, it is anticipated that it may be used as a secondary product for concrete or buildings that require superior long-term strength and durability compared to regular Portland cement. However, as no clear results were found in this study regarding the substitution of metakaolin, it displayed mixed results in comparison to previous studies. Nevertheless, it is expected that metakaolin will become a more superior admixture if its issues are improved through continuous research studies.