To improve the environmental management and resources, in this study, we aimed to investigate the effect of adding oyster shell powder to Hanwoo manure on its characteristics and microbial composition during the storage period. Additives were deposited on top of the manure surface at the rate of 0, 0.5, and 1% of oyster shell powder per 200 g of Hanwoo manure in a plastic container with three replicates; however, untreated manure litter served as the control. Manure characteristics (dry matter, organic matter and crude ash) and microbial composition (lactic acid bacteria, yeast, Bacillus subtilis, Salmonella, and E.coli) were evaluated at day 0, 2, 4, and 8. Manure characteristics exhibited an effect on dry matter, organic matter, and crude ash at day 2 and 8 (p<0.05), and not for day 0 and 4 (p>0.05). With the exception of yeast content at day 4 of storage, lactic acid bacteria, yeast, Bacillus subtilis, Salmonella, and E.coli exhibited no significant differences in all conditions during the storage period. Conclusively, addition of 1% oyster shell powder to Hanwoo manure resulted in slightly better manure characteristics; however, its microbial composition remained unchanged.

본 연구는 초등학생이 인식하는 학교스포츠클럽 지도자 이미지가 수업 태도에 미치는 영향을 규명하는 것이다. 연구대상은 초등학교에 재학 중인 4∼6학년 남·여 학생이며 구조화된 설문지를 사용하여 2019년 4월부터 6월까지 자료를 수집하였다. 총 520부의 설문을 회수하여 불성실하게 응답한 자료를 제외한 후 총 470부를 연구에 사용하였다. 자료 분석은 SPSS 22.0을 사용하였고, 타당도 및 신뢰도 검증을 위해 확인적 요인 분석과 Cronbach's α 검증을 실시하였다. 연구 결과는 다음과 같다. 첫째, 인구통계학적 특성에 따른 학교스포츠클럽 지도자 이미지의 차이에서는 학년, 체육교과 관심도, 학교스포츠클럽 지도자 유형, 학교스포츠클럽 지도자 연령에서 유의미한 차이가 있었다. 둘째, 인구통계학적 특성과 수업 태도 변인 간의 차이에서는 학생 성별, 학년, 체육교과 관심도, 학교스포츠클럽 지도자 유형에서 유의미한 차이가 있었다. 셋째, 학교스포츠클럽 지도자 이미지와 수업 태도의 관계는 부분적으로 유의한 정(+)상관이 있는 것으로 나타났다.

In the current study, MIL-101(Cr)-SO3H[HCl] as metal-organic frameworks (MOFs) was fabricated via a hydrothermal method. The physicochemical properties of the synthesized material were characterized using XRD, FT-IR, FE-SEM, TEM, and BET surface area analysis. The XRD diffraction pattern of the prepared MIL-101(Cr)-SO3H[HCl] was similar to previously reported patterns of MIL-101(Cr) type materials, indicating successful synthesis of MIL-101(Cr)-SO3H[HCl]. The FT-IR spectrum revealed the molecular structure and functional groups of the synthesized MIL-101(Cr)-SO3H[HCl]. FE-SEM and TEM images indicated the formation of rectangular parallelopiped structures in the prepared MIL-101(Cr)-SO3H[HCl]. Furthermore, the EDS spectrum showed that the synthesized material consisted of the elements of Cr, O, S, and C. The fabricated MIL-101(Cr)-SO3H[HCl] was then employed as an adsorbent for the removal of Sr2+ and Cs+ from aqueous solutions. The adsorption kinetics and adsorption isotherm models were studied in detail. The maximum adsorption capacities of MIL-101(Cr)-SO3H[HCl] for Sr2+ and Cs+ according to pH (3, 5.3∼5.8, 10) were 35.05, 43.35, and 79.72 mg/g and 78.58, 74.58, and 169.74 mg/g, respectively. These results demonstrate the potential of the synthesized MOFs, which can be effectively applied as an adsorbent for the removal of Sr2+ and Cs+ ions from aqueous solutions and other diverse applications.

In the current study, a Cu2O/TiO2 photoinduced nanocomposite materials prepared by ultrasonification method was evaluated the photocatalytic oxidation efficiency of volatile organic compounds (BTEX) under visible-light irradiation. The results of XRD confirmed the successful preparation of photoinduced nanocomposite materials. However, diffraction peaks belonging to TiO2 were not confirmed for the Cu2O/TiO2. The possible reason for the absence of Cu2O peak is their low content and small particle size. The result of uv-vis spectra exhibited that the fabricated Cu2O/TiO2 can be activated under visible light irradiation. The FE-SEM/EDS and TEM showed the formation of synthesized nanocomposites 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 undoped TiO2. According to light sources, the average oxidation efficiencies for BTEX by Cu2OT-0.5 were exhibited in the orer of 8 W day light > violet LEDs > white LEDs. However, the photocatalytic oxidation efficiencies normalized to supplied electric power were calculated to be in the following order of violet LEDs > white LEDs > 8 W day light, indicating that the LEDs could be a much more energy efficient light source for the photo-oxidation of gaseous BTEX using Cu2O/TiO2.

Zeolite material having XRD peaks of Na-A zeolite in the 2θ range of 7.18 to 34.18 can be synthesized from the waste catalyst using a fusion/hydrothermal method. The adsorption rate of Mn ions by a commercial Na-A zeolite and the synthesized zeolitic material increased as the adsorption temperature increased in the range of 10 ~ 40℃. The adsorption of Mn ion were very rapid in the first 30 min and then reached to the equilibrium state after approximately 60 min. The adsorption kinetics of Mn ions by the commercial Na-A zeolite and the zeolitic material were found to be well fitted to the pseudo-2nd order kinetic model. Equilibrium data by the commercial Na-A zeolite and the zeolitic material fit the Langmuir, Koble-Corrigan, and Redlich-Peterson isotherm models well rather than Freundlich isotherm model. The removal capacity of the Mn ions by the commercial Na-A zeolite and the zeolitic material obtained from the Langmuir model was 135.2 mg/g and 128.9 mg/g at 30℃, respectively. The adsorption capacity of Mn ions by the synthesized zeolitic material was almost similar to that of commercial Na-A zeolite. The synthesized zeolitic material could be applied as an economically feasible commercial adsorbent.

본 연구는 8개 영재학교 체육과 교육과정을 내용과 평가를 중심으로 비교·분석하여 영재학교 특성에 맞는 체육과 교육과정 운영방안을 모색하고자 시도하였다. 연구 목적을 달성하기 위해 전국 8개 영재학교의 2019학년도 학교 교육 과정 편성·운영 및 평가에 관한 규정, 체육과 평가계획 등의 자료를 수집하였다. 이를 바탕으로 실제 각 학교에서 이루어지고 있는 체육과 관련된 전반적인 자료를 수집하기 위해 5명의 영재학교 체육 교사를 연구참여자로 설정하여 심층 면담을 진행하였다. 수집된 자료는 Bereday(1964)의 비교방법론과 주제별 부호화 과정을 통해 연구 목적에 맞게 분류 및 해석하였다. 연구 결과 학교 교육 과정 편성에 따른 체육과 운영실태, 체육교과 편제표, 체육과 교과목별 평가내용에 차이를 분석할 수 있었다. 영재학교 체육과 교육과정의 특성은 학점제, 현장 교사의 자율성에 의한 교육과정 운영, 소수의 학생을 대상으로 맞춤형 수업, 수업환경의 최신화로 다양한 수업 가능, P/F 평가시스템 운영으로 분석되었다. 영재학교 특성에 맞는 체육과 교육과정 운영방안 모색 결과는 P/F 평가 기준의 규격화, 스포츠 교류전을 활용한 체육과 교육과 정 운영, 학생 참여 중심의 체육과 교육과정 운영, 평생스포츠 기반을 위한 1인 1기 활동 참여의 권장으로 제시할 수 있었다.

이 논문의 목적은 다른 종류의 폴리에틸렌 섬유로 보강한 높은 연성을 갖는 고강도 시멘트계 복합체의 재료강도와 인장변형거동을 실험적으로 연구하는 것이다. 이를 위하여 압축강도 80 MPa 수준의 재료 및 배합을 결정하였고, 보강 섬유로서 2 종류의 폴리에틸렌 섬유를 사용하였다. 그리고 밀도, 압축강도, 1축 인장변형에 대한 일련의 실험을 수행하였다. 실험결과 시멘트계 복합체의 인장거동과 균열 패턴은 보강 섬유의 특성에 크게 영향을 받는 것으로 나타났다. 또한 적절한 폴리에틸렌 섬유를 사용함으로써 재료의 압축강도가 77.7 MPa 이고, 인장변 형성능이 7.9% 변형률인 시멘트계 복합체의 제조가 가능하다는 것을 확인하였다.

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.

This study investigates the usage behavior and the perception of horticulturalists (horticultural activists) and simple users for urban community gardens. To this end, we surveyed 100 horticulturalists and 213 simple users. Questions in the survey are divided into five categories: 1) usage behavior of community gardens, 2) perception on the benefits of community gardens, 3) perception on the pros and cons of setting up community gardens, 4) willingness to pay for community gardens, 5) importance of specific benefits provided by community gardens. According to the survey, 95.0 percent of horticulturalists and 93.4 percent of simple users supported setting up community gardens. 58.0 percent of horticulturalists and 60.6 percent of simple users were willing to pay their residence tax for community gardens. And the annual membership fee plus resident tax of horticulturalists is 460,455 KW per person, which is 80.6 times more than willingness to pay of simple users. The results of this study can be used as basis data for valuing community gardens.

이 연구에서는 단일 활성화제로 활성화시킨 슬래그 기반 섬유보강 복합재료의 초기재령에서 인장거동을 조사하였다. 실험 결과, 활성화제 종류에 따라 재령 7일에서 균열강도, 인장강도, 인장변형성능에 차이가 있었으며, 규산나트륨을 활성화제로 사용한 배합이 가장 큰 인장변형성능을 나타내었다.

이 연구에서는 무기계 결합재 비율에 따른 섬유보강 복합재료의 압축 및 인장 특성을 조사하였다. 실험 결과, 무기계 분말 재료를 시멘트의 30 % 대체 혼입할 경우, 압축강도, 인장강도 및 인장변형성능은 각각 93.2 MPa, 6.71 MPa, 및 7.65 %로 나타났다. 이는 시멘트만 사용한 복합재료보다 인장변형성능이 약 2.2배 향상된 결과이다.

In this study, the sensitivity analysis of hydraulic conductivity and separation distance (distance between injection well and pumping well) was analyzed by establishing a conceptual model considering the hydrogeologic characteristics of facility agricultural complex in Korea. In the conceptual model, natural characteristics (topography and geology, precipitation, hydraulic conductivity, etc.) and artificial characteristics (separation distance from injection well to pumping well, injection rate and pumping rate, etc.) is entered, and sensitivity analysis was performed 12 scenarios using a combination of hydraulic conductivity (10-1 cm/sec, 10-2 cm/sec, 10-3 cm/sec, 10-4 cm/sec) and separation distance (10 m, 50 m, 100 m). Groundwater drawdown at the monitoring well was increased as the hydraulic conductivity decreased and the separation distance increased. From the regression analysis of groundwater drawdown as a hydraulic conductivity at the same separation distance, it was found that the groundwater level fluctuation of artificial recharge aquifer was dominantly influenced by hydraulic conductivity. In the condition that the hydraulic conductivity of artificial recharge aquifer was 10-2 cm/sec or more, the radius of influence of groundwater level was within 20 m, but In the condition that the hydraulic conductivity is 10-3 cm/sec or less, it is confirmed that the radius of influence of groundwater increases sharply as the separation distance increases.

이 연구는 다문화가정 초등학생들의 학교스포츠클럽 참여 여부 및 참여정도가 의사소통역량과 또래관계에 미치는 영향을 규명하는데 그 목적이 있다. 연구 목적을 달성하기 위해 경기도, 강원도, 충청북도에 위치한 초등학교 재학생 1~6학년 중 다문화가정 학생 108명을 대상으로 자기평가 기입법 설문조사를 실시하여 불성실한 응답이 있는 5부를 제외한 103부에 대하여 분석을 실시하였다. 통계분석은 IBM SPSS Statistics 25를 사용하였고, 타당도 및 신뢰도 검증을 위해 탐색적 요인분석과 Cronbach's α 를 검증을 실시하였다. 연구결과, 학교스포츠클럽 참여유무에 따라 의사 소통역량의 하위요소인 목표설정역량, 해석역량, 메시지전환역량에서 유의미한 차이가 있었다. 또 한, 학교스포츠클럽 참여유무에 따라 또래관계의 하위요소인 의사소통, 신뢰, 화 및 소외감에서 유 의미한 차이가 있었다. 마지막으로 의사소통역량은 또래관계에 부분적으로 정적인 영향을 미치는 것으로 나타났다. 이상의 결과를 바탕으로 다문화가정 초등학생들의 의사소통역량 향상과 긍정적인 또래관계 형성을 위해 학교스포츠클럽을 적극적으로 권장하고 정부차원에서 충분한 지원이 이루어져야 할 것이다.

A zeolitic material (Z-Y2) was synthesized from Coal Fly Ash (CFA) using a fusion/hydrothermal method under low-alkali condition (NaOH/CFA = 0.6). The adsorption performance of the prepared zeolite was evaluated by monitoring its removal efficiencies for Sr and Cs ions, which are well-known as significant radionuclides in liquid radioactive waste. The XRD (X-ray diffraction) patterns of the synthesized Z-Y2 indicated that a Na-A type zeolite was formed from raw coal fly ash. The SEM (scanning electron microscope) images also showed that a cubic crystal structure of size 1~3㎼ was formed on its surface. In the adsorption kinetic analysis, the adsorption of Sr and Cs ions on Z-Y2 fitted the pseudo-second-order kinetic model well, instead of the pseudo-first-order kinetic model. The second-order kinetic rate constant (k2) was determined to be 0.0614 g/mmol·min for Sr and 1.8172 g/mmol·min for Cs. The adsorption equilibria of Sr and Cs ions on Z-Y2 were fitted successfully by Langmuir model. The maximum adsorption capacity (qm) of Sr and Cs was calculated as 1.6846 mmol/g and 1.2055 mmol/g, respectively. The maximum desorption capacity (qdm) of the Na ions estimated via the Langmuir desorption model was 2.4196 mmol/g for Sr and 2.1870 mmol/g for Cs. The molar ratio of the desorption/adsorption capacity (qdm/qm) was determined to be 1.44 for Na/Sr and 1.81 for Na/Cs, indicating that the amounts of desorbed Na ions and adsorbed Sr and Cs ions did not yield an equimolar ratio when using Z-Y2.

This study investigated the comparison of tensile properties between cement and cementless composite with polyarylate fiber. Test results showed that the cementless composite with polyarylate fiber showed lower strength and higher tensile strain capacity than the cement composite with polyarylate fiber.

This study investigated the impact resistance properties of UHPC and HDFRC. Test results showed that the HDFRC mixture has a higher penetration depth than the UHPC mixture, however, the HDFRC mixture has a higher impact resistance performance without perforation based on high ductility through multiple micro cracks.

This study investigated the damping properties of preplaced concrete with W/C and coarse aggregate size was . Experimental results show that the damping ratio of the C40 is 2.63%, which is 1.72 times higher than the damping ratio of the C30 of 1.53%. The higher the water cement ratio, the higher the damping ratio is. In addition, the damping ratio of the C-PA series is reduced by 17% to 60% as compared with the C-series. The difference of the damping ratio due to the coarse aggregate size in the C-PA series was found to be within the standard deviation

Sea gulls are high trophic level consumers in the coastal environment, and thus, which have been widely used to monitor contamination biomagnified through a food web. However, such monitoring studies using sea gulls have been rare in the Korean literature. The National Environmental Specimen Bank chose eggs of a black-tailed gulls (Larus crassirostris) to serve as an environmental specimen for the long-term monitoring of the coastal ecosystem affected by terrestrial pollutants. Black-tailed gull eggs were collected from Baengnyeongdo, Hongdo and Uleungdo, and their DDTs and total mercury content were determined. The highest concentration of ΣDDTs was 231.6±106.1 μg/kg wet in Baengnyeongdo, followed by 230.0±123.8 μg/kg wet in Ulleungdo, and 117.7±18.3 μg/kg wet in Hongdo. In addition, total mercury was detected at 414.5±97.6 μg/kg wet in Ulleungdo, 363.9±123.6 μg/kg wet in Hongdo, and 237.5±42.3 μg/kg wet in Baengnyeongdo. Relatively high concentrations of the target pollutants were recorded in specimens from Ulleungdo. Additional comprehensive and prolonged studies are required to elucidate spatial and temporal patterns of contamination in black-tailed gull eggs with regard to monitoring contaminant trends in eggs and prey.

The National Environmental Specimen Bank (NESB) has been sampling and cryogenically preserving various wildlife specimens to monitor bio-accumulations of chemical pollutants since 2010. Recently, the NESB set up a plan to develop reference materials at their facility to assure the analytical quality of and validate the analytical methods for their monitoring samples. One of the crucial characteristics of reference materials is intra- and inter-bottle homogeneity. In this study, we used ANOVA for total mercury concentrations in some samples to validate their homogeneities after milling and homogenization. We examined the intra- and inter-bottle homogeneities of two cryogenically-milled samples (Korean mussel (Mytilus coruscus) and black-tailed gull’s egg (Larus crassirostris). The variations in the total mercury concentrations were not significantly different intra- and inter-bottle (mussel: F=0.74, p=0.67; gull egg: F=1.96, p=0.10). Additionally, the relative standard deviations of the total mercury concentrations showed low values (mussel: 2.02%, gull egg: 1.78%). Therefore, the cryogenic-milling process statistically proves the homogeneity of the materials of mussels and sea gull eggs for chemical analysis for total mercury.

In this study, we evaluated the photocatalytic oxidation efficiency of aromatic volatile hydrocarbons by using WO3–doped TiO2 nanotubes (WTNTs) under visible-light irradiation. One-dimensional WTNTs were synthesized by ultrasonic-assisted hydrothermal method and impregnation. XRD analysis revealed successful incorporation of WO3 into TiO2 nanotube (TNT) structures. UV-Vis spectra exhibited that the synthesized WTNT samples can be activated under visible light irradiation. FE-SEM and TEM images showed the one-dimensional structure of the prepared TNTs and WTNTs. The photocatalytic oxidation efficiencies of toluene, ethylbenzene, and o-xylene were higher using WTNT samples than undoped TNT. These results were explained based on the charge separation ability, adsorption capability, and light absorption of the sample photocatalysts. Among the different light sources, light-emitting-diodes (LEDs) are more highly energy-efficient than 8-W daylight used for the photocatalytic oxidation of toluene, ethylbenzene, and o-xylene, though the photocatalytic oxidation efficiency is higher for 8-W daylight.