The intensive development of the petrochemical industry globally reflects the necessity of an efficient approach for oily sludge and wastewater. Hence, for the first time, the current study utilized magnetic waxy diesel sludge (MWOPS) to synthesize activated carbon coated with TiO2 particles for the removal of total petroleum hydrocarbons (TPH) and COD from oily petroleum wastewater (OPW). The photocatalyst was characterized using CHNOS, elemental analysis was performed using X-ray fluorescence spectroscopy (XRF), field emission scanning electron microscope (FESEM), high-resolution transmission electron microscope (HR-TEM), X-ray diffraction analysis (XRD), Fourier transform infrared spectrometer (FTIR), Raman, energy dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopy (XPS), MAP thermo-gravimetric analysis/ differential thermo-gravimetric (TGA–DTG), Brunauer–Emmett–Teller (BET), diffuse reflectance spectroscopy (DRS), and vibrating sample magnetometer (VSM). The optimization of synthesized highly porous AC/Fe3O4/TiO2 photocatalyst was conducted considering the impacts of pH, temperature, photocatalyst dosage, and UVA6W exposure time. The results demonstrated the high capacity of the MWOPS with inherent magnetic potential and desired carbon content for the removal of 91% and 93% of TPH and COD, respectively. The optimum conditions for the OPW treatment were obtained at pH 6.5, photocatalyst dosage of 250 mg, temperature of 35 °C, and UVA6W exposure time of 67.5 min. Moreover, the isotherm/kinetic modeling illustrated simultaneous physisorption and chemisorption on heterogeneous and multilayer surfaces. Notably, the adsorption efficiency of the AC/Fe3O4/TiO2 decreased by 4% after five adsorption/desorption cycles. Accordingly, the application of a well-designed pioneering photocatalyst from the MWOPS provides a cost-effective approach for industry manufacturers for oily wastewater treatment.

In the present work, a three-phase AC arc plasma torch system is proposed to separate inorganic radioactive materials from the organic liquid waste. For this purpose, first, assuming the resistance of arc plasma ranges between 0.1 and 0.2 ohm, we designed a three-phase AC arc plasma power supply with the power level of 20 kW. Then, a three phase arc plasma torch consisting of three carbon rods with the diameter of 20 mm was designed and mounted on a cylindrical combustion chamber with the inner diameter of 150 mm. Detail design and basic performance of the plasma system were presented and discussed for application to the treatment of radioactive slurry wastes.

본 연구는 ‘인생에서 사회경제적으로 성취한 것에 대한 만족도’를 의미하는 사회적․경제적 성취만족도(협의의 성취만족도)를 다루고 있다. ‘성취동기’는 성취를 이끌어 내는 데에 초점을 두고 있는데 비해, ‘성취만족도’는 성취에 대한 개인적인 평가와 의미에 초점을 두는 개념이다. 성취만족도는 성취와 성취동기의 상호작용에 있어서 연결고리의 역할을 하며 성취와 성취동기에 대한 입체적 분석을 가능케 한다. 또한, 성취만족도는 사회인구학적 변수들(소득, 재산, 학력 등)이 생활만족도나 성평등 등에 미치는 영향을 분석할 때에도 매개적 역할을 할 것으로 기대되는 변수이다. 이런 효용에도 불구하고 아직 성취만족도에 대한 학술적 차원의 연구가 많지 않은 상황이다. 이에 본 연구는 성취만족도를 실증적으로 탐색하기 위한 연구를 진행하였다. 본 연구는 통계청에서 진행한 2018~2020 년 사회조사 데이터를 활용하였으며, 만 19세 이상의 성인 35,331명을 대상으로 하였다. 기술적 분석과 t-test, ANOVA를 사용하여 데이터를 분석하였다. 본 연구의 연구결과, 성취만족도는 성별·연 령집단 내에서 코로나19 전후로 차이를 보였고, 주거점유 형태에 따라서도 차이를 보였으며, 또한 교육정도에 따라서도 차이를 보였다.

Abstract In this study, we investigated that the activated carbon (AC)-based supercapacitor and introduced SIFSIX-3-Ni as a porous conducting additive to increase its electrochemical performances of AC/SIFSIX-3-Ni composite-based supercapacitor. The AC/SIFSIX-3-Ni composites are coated onto the aluminum substrate using the doctor blade method and conducted an ion-gel electrolyte to produce a symmetrical supercapacitor. The electrochemical properties of the AC/SIFSIX-3-Ni composite-based supercapacitor are evaluated through cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge/discharge tests (GCD). The AC/SIFSIX-3-Ni composite-based supercapacitor showed reasonable capacitive behavior in various electrochemical measurements, including CV, EIS, and GCD. The highest specific capacitance of the AC/SIFSIX-3-Ni composite-based supercapacitor was 129 F g−1 at 20 mV s−1.

Recently, studies have been actively conducted on seismic design and improvement of the seismic performance of bridges, buildings, factories, and plants. In particular, heavy items that are being manufactured or waiting to be shipped from factories (such as generators, engines, and boilers) must be equipped with seismic stoppers to prevent them from moving or falling during an earthquake. Seismic stoppers should be suitably determined by the size and weight of these heavy items; however, they have no general design standard. In this study, structural analyses and seismic tests were conducted to evaluate the performance of newly designed seismic stoppers. Structural analysis was performed on three stopper models to estimate the external load at which the yield stress of the material was not exceeded. Based on the analysis results, a seismic test of the stopper was carried out in accordance with the AC156 test method. Finally, product specifications for all three seismic stopper models were determined and their static/dynamic load performance was evaluated.

The reduced graphene oxide (rGO)/activated carbon (AC) composites are coated on the aluminum substrate using spray coating technique to fabricate nanocarbon-based supercapacitor. Polymer-based solid-state xanthan-gum/Na2SO4 electrolyte is also introduced to increase stability of the supercapacitor. The electrochemical properties of the supercapacitor are evaluated using cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge/discharge tests. The highest capacitance value of the rGO/AC composite-based supercapacitor is 120 F/g. The rGO/AC composite-based supercapacitor has also retained ~ 85% of its initial capacitance value after 3000 galvanostatic charge/discharge cycles.

국내 고속도로는 아래 fig 1.(left)과 같이 1970년 개통한 경부고속도로를 시작으로 2010년대에 접어들면서 전국에 도로 네트워크를 구성하였다. 최근 노후화된 포장의 증가로 도로 포장 유지관리에 대한 필요성이 증가하고 있으며, fig 1.(right)는 보수 기법으로 아스팔트 덧씌우기의 비율이 약 62%로 지배적인 것을 보여준다. 하지만, 아스팔트 덧씌우기 또는 복합 포장의 부착 상태가 불량할 경우 포장 수명의 최대 80%까지 감소된다는 연구결과가 보고되었음에도(Khweir and Fordyce, 2003), 국내에서는 명확한 평가 기준이 마련되어 있지 않다. 따라서, 본 연구는 기존 콘크리트 포장 위 아스팔트 덧씌우기의 부착 저항성 평가 방법에 대한 기준을 제시하고, 온도와 표면 거칠기에 따른 부착 거동 특성을 정의하였다. 실험 방법으로는 부착 파손의 결정적인 전단 모드에 대하여 평가하였으며, 장비는 Direct Shear Tester를 이용하여 평가하였으며, 실험의 반복성을 향상시키기 위해 포장 거칠기 모사 시편을 제작하여 평가하였다. 평가 결과 온도와 표면 거칠기에 따라 영향을 받는 것을 확인하였으며, 높은 온도에서 낮은 최대 전단강도를 보였고, 표면 거칠기에 따라서는 MTD가 가장 높은 6mm Tinning이 아닌 Undersealing 표면에서 가장 높은 최대 전단강도를 나타내었다. 다음 fig 2.는 다양한 온도에서 표면 거칠기에 따른 전단 거동을 비교한 그래프이다.

PURPOSES : This study focuses on the evaluation of interface performance with varying surface texture and tack coat application in an asphalt overlay. METHODS : The evaluation is carried out in two phases: tracking test and interface bond strength test. Using an image processing tool, tracking test is conducted to evaluate the susceptibility of the tack coat material to produce excessive tracking during application. Using the pull-off test method, the bond strength test is performed to determine the ability of the interface layer to resist failure. RESULTS: Results show that the underseal application yields less tracking compared to other applications. However, the bond strength is barely within the minimum acceptable value. On the other hand, RSC-4 produces higher bond strength for all surface types, but the drying time is long, which produces excessive tracking. CONCLUSIONS: While underseal application may be suitable for a trackless condition, the bond strength is less appealing compared to the rest of the tack applications available. RSC-4 demonstrated a high and consistent bond strength performance, but more time is required for drying to avoid excessive tracking. Tack coat application and surface type combination produce varying results. Therefore, these should be considered when selecting suitable future tack coat application options.

Metal matrix composites(MMC) can obtain mechanical characteristics of application purposes that a single material is difficult to obtain. Al2 O3/AC8A composites were fabricated by low pressure infiltration process. The purpose is establishing the optimal casting conditions for composite preparation under low pressure. It is known the inorganic binder help infiltration. Therefore Al2O3 fiber preform's optimum sinter temperature is 1160℃, added inorganic binder is mixed binder(SiO2 sol:Al2O3 sol=5:2). And three fibers have been compared (Al2O3 80%/SiO2 20%, Al2O3 80%/SiO2 10% and Al2O3 97%/SiO2 3%). Al2O3/AC8A composites was made by each melting temperatures(650℃, 700℃, 750℃) and wear test was performed about effect of temperatures, kind of fiber, matrix and composites, aging time. Wear test is Ball on disk wear test. The resistance increased with the low melting temperature and Al2O3 80%/SiO2 20% fiber.

Ni and Ni-Cr reinforced Al alloy (AC8A) composites were fabricated by low pressure infiltration process. Porous Ni was applied as preform. Ni reinforced AC8A composites were fabricated under 0.3 MPa at 650, 700 and 750 degrees centigrade, respectively, while Ni-Cr reinforced AC8A composites were fabricated under low pressure limited to the maximum of 0.5 Mpa at 750, 800 and 850 degrees centigrade, respectively. Microstructure and phase composition of the composites were evaluated by optical microscope, X-Ray diffraction (XRD), electro-probe micro analyzer (EMPA). Intermetallic compounds Al3Ni and CrSi were observed in the composites. The results indicate that the grain size has been increasing with the increase of the infiltration temperatures. However, the wear resistance of Ni/AC8A and Ni-Cr AC8A peaked at 650 degree centigrade and 800 degrees centigrade, respectively. In addition, based on the wear characteristics and wear surfaces, Ni-Cr/AC8A composites have a better wear resistance than Ni/AC8A composites and AC8A.

A large number of transgenic crop varieties expressing the Bt (Bacillus thuringiensis) insecticidal proteins have been commercialized in 13 countries since 1996. Although the use of these insect-resistant Bt crops can increase crop quality and yields, concerns remain about the potential negative effects of such crops on ecosystems. Transgenic soybean containing cry1Ac gene have been developed to control Lepidopteran pests of soybean and we aimed to investigate whether this soybean could affect non-target arthropods, which play a major role in ecological functions in agricultural ecosystems. In the present study, we first measured the levels of Cry1Ac protein in Bt soybean at different growth stages of soybean and then we compared the community structure of arthropods occurred in fields of transgenic and wild-type soybean. The levels of Cry1Ac protein in transgenic soybean leaves ranged from 252.9 to 604.5 μg g-1 DW. Multivariate analyses (PerMANOVA and NMDS) showed that the composition of the non-target arthropod community was affected by sampling date but not by soybean genotype. These results suggest that transgenic soybean expressing Cry1Ac protein may not adversely affect such non-target arthropod communities.

목 적: 본 연구에서는 사위 그룹에서 가입구면굴절력에 따른 일반적인 경사AC/A비와 자극(±)AC/A비 및 반응(±)AC/A비의를 측정값을 비교분석하고자 하였다. 방 법: 성인 85명(남자 55명, 여자 30명, 평균 만 20.72±1.78세)을 대상으로 검사거리 40cm에서 개방 형 자동굴절계(Nvision-K 5001)와 수정된 토링톤 시표(MIM card, Muscle Imbalance Measure card)를 이 용하여 양안시 상태에서 조절반응량과 근거리 수평사위량을 측정하여 일반적인 경사AC/A비, 자극(±)AC/A 비 및 반응(±)AC/A비를 구하였다. 결 과: 일반적인 경사AC/A비와 자극(±)AC/A비를 비교하였을 때, 외사위 그룹에서는 (-)렌즈를 부가하 였을 때, 자극(-)AC/A비가 일반적인 경사AC/A비보다 크게 나타났고, 내사위 그룹에서는 (+)렌즈를 부가 하였을 때, 자극(+)AC/A비가 일반적인 경사AC/A비보다 크게 나타났으나 통계적으로 유의한 차이는 보이지 않았다. 일반적인 경사AC/A비와 반응(±)AC/A비를 비교 하였을 때, 외사위 그룹에서는 -0.50D, -1.00D, -1.50D, -2.00D 렌즈를 가입하였을 때(p〈0.05), 내사위 그룹에서는 +0.50D, +1.00D, +1.50D, +2.00D 렌즈를 가입하였을 때(p〈0.05), 통계적으로 유의한 차이를 보였다. 가입렌즈에 따른 반응(±)AC/A비를 반 복 측정하여 분석한 결과, 외사위 그룹에서는 (-)렌즈를 부가하였을 때 그리고 내사위 그룹에서는 (+)렌즈 를 부가하였을 때, 반응(-)AC/A비와 반응(+)AC/A비가 통계적으로 유의한 차이를 보였다(p〈0.05). 결 론: 외사위에서 (-)렌즈 가입, 내사위에서는 (+)렌즈 가입에 따른 조절성폭주량이 큰 변화를 보였다. 따라서 렌즈 가입을 통한 양안시이상 처치에서 반응(+)AC/A비와 반응(-)AC/A비를 구분하여 적용할 필요가 있을 것으로 사료된다.