PURPOSES : This study was conducted to evaluate the physical properties of micro-foamed asphalt binders. Surfactants and water-soluble anti-stripping agent were used to improve the performance of the foamed asphalt binder, and a domestically developed foamed asphalt generator was used for the micro-foamed asphalt binder. The results of this study can be used as technical data for the domestic application of foamed asphalt technology. METHODS : To evaluate the physical properties of the micro-foamed asphalt binder, basic properties such as penetration, viscosity, softening point, and ductility were evaluated. Additionally, DSR and BBR tests were performed to confirm the change in the performance grade of the micro-formed asphalt binder when using surfactants, water-soluble anti-stripping agent, and water. RESULTS : Of the results of evaluating the physical properties of the micro-foamed asphalt binder containing surfactant confirmed that the kinematic viscosity was reduced by 12.5% compared with the straight asphalt binder, which indirectly confirmed that compaction is possible even at low temperatures when producing the asphalt mixture. In addition, the PG grade of straight asphalt and micro-foamed asphalt binder was PG 64-22. This result indicates that surfactants, water-soluble anti-stripping agent, and water did not significantly affect the PG grade of the asphalt binder. CONCLUSIONS : The properties of the micro-foamed asphalt binder were confirmed through the evaluation of the physical and rheological properties of the foamed asphalt binder to which the surfactant and water-soluble anti-stripping agent were applied, and we determined that it can be used as a technical material for the revitalization of Korean foamed asphalt technology.

In decommissioning a nuclear power plant, numerous concrete structures need to be demolished and decontaminated. Although concrete decontamination technologies have been developed globally, concrete cutting remains problematic due to the secondary waste production and dispersion risk from concrete scabbling. To minimize workers’ radiation exposure and secondary waste in dismantling and decontaminating concrete structures, the following conceptual designs were developed. A micro-blast type scabbling technology using explosive materials and a multi-dimensional contamination measurement and artificial intelligence (AI) mapping technology capable of identifying the contamination status of concrete surfaces. Trials revealed that this technology has several merits, including nuclide identification of more than 5 nuclides, radioactivity measurement capability of 0.1–107 Bq·g−1, 1.5 kg robot weight for easy handling, 10 cm robot self-running capability, 100% detonator performance, decontamination factor (DF) of 100 and 8,000 cm2·hr−1 decontamination speed, better than that of TWI (7,500 cm2·hr−1). Hence, the micro-blast type scabbling technology is a suitable method for concrete decontamination. As the Korean explosives industry is well developed and robot and mapping systems are supported by government research and development, this scabbling technology can efficiently aid the Korean decommissioning industry.

The production of macroalgae-derived adsorbent is of great importance to realize the idea of treating pollutants with invaluable renewable materials. Herein, a novel meso-micro porous nano-activated carbon was prepared from green alga Ulava lactuca in a facile way via chemical activation with zinc chloride. The resultant activated carbon possesses a significant specific surface area 1486.3 m2/ g. The resulting activated carbon was characterized and investigated for the adsorption of Direct Red 23 (DR23) dye from an aqueous environment. Batch method was conducted to study the effects of different adsorption processes on the DR23 dye adsorption from water. Isotherms and kinetics models were investigated for the adsorption process of DR23 dye. It was found that the adsorption data were well fitted by Langmuir model showing a monolayer adsorption capacity 149.26 mg/g. Kinetic experiments revealed that the adsorptions of DR23 dye can be described with pseudo-secondorder model showing a good correlation (R2 > 0.997). The prepared activated carbon from Ulava lactuca was exposed to a total of six regeneration experiments. The regeneration result proved that the fabricated activated carbon only loses 19% of its adsorption capacity after six cycles. These results clearly demonstrated the high ability of the obtained active carbon to absorb anionic dyes from the aqueous environment.

도시의 역사와 건설 환경의 대 발전은 언제나 다음과 같은 딜레마에 직면해 있다. 온전한 역사적 보호인가 아니면 도시재생인가? 어반 아큐펀쳐는 도시의 고유한 분위기 유지와 도시의 전반적인 발전, 이 두 가지를 모두 충족할 수 있는 또 하나의 도시발전 전략이다. 어반 아큐펀쳐는 엄격한 정의와 보편적인 표준 패턴이 없이도 내포된 내용이 풍부하고 개방적인 도시 발전 전략으로서 상당히 다양한 해석과 이해를 가지고 있는데, 한국의 도시재생과 관련된 본 연구에는 마누엘 데 모랄레스의 개념이 큰 계기를 마련해주었다. 한국과 유럽, 중국의 다양한 문헌 자료 조사 연구를 통해, 문화와 환경의 관점에서 거리 조각을 도시 촉매로 삼아 지역의 발전 잠재력을 촉진하고 도시재생과의 관계를 탐구하는 연구는 많지 않다는 것을 발견했기 때문이다. 그리하여 도시재생과 어반 아큐펀쳐에 대한 연구 및 그와 관련된 사례는 여전히 건축 및 구역의 개조, 공공 인프라의 업그레이드, 공공 공간 및 도로 교통의 최적화라는 것을 알 수 있었다. 문화적 측면에서도 도시재생과 어반 아큐펀쳐에 대한 연구 및 사례는 비교적 거시적일 뿐만 아니라 주로 도시설계에 관한 주제가 주를 이루고 있다. 따라서 본 연구에서는 어반 아큐펀쳐와 거리에 우뚝자리 잡고 있는 조각을 결합하고 이 조각을 통해 거리의 관건이 되는 혈점을 선택하여 소규모로 개입하거나 마이크로 임플랜테이션할 것을 주장하였다. 본 연구의 목적은 이를 바탕으로 도시재생의 큰 틀에서 조각의 아큐펀쳐과 조각의 마이크로 임플랜테이션이라는 개념을 정련하는 것이다. 따라서 이를 계기로 도시재생의 새로운 방향을 제시하고 향후 도시재생의 실천에도 참고할 수 있는 사료를 제공하고자 하였다. 이에 본 연구는 어반 아큐펀쳐와 도시 내 조각품의 사례를 각각 분석하고 마이크로 임플랜테이션이라는 개념 아래에서 양자의 비교를 통한 결합 가능성을 모색함으로써 도시재생에 있어서 도시공학이나 도시디자인의 범주 아래에서 공공조형의 역할과 기능을 통합할 수 있다는 사실을 확인하고 제시했다는 점에서 의의가 있을 것이다.

본 연구에서는 polyketone (PK)을 이용하여 전기방사 조건에 따른 섬유 형상의 특성 변화와 유수분리 가능성을 확인해 보았다. 고습과 저습 조건에서는 마이크론 직경의 섬유가 형성되었으며, 특히 고습에서는 섬유의 표면이 거칠게 변한 것이 확인되었다. 섬유 직경을 micro에서 nano로 변경하기 위하여 방사용액에 염을 추가하였으며, 그 결과 섬유 직경이 약 90% 감소하는 것을 확인할 수 있었다. 제조된 rPK-LNC와 PK-H로 유수분리 특성을 확인하기 위해 oil/water 에멀션으로 중 력 조건에서 유수분리를 진행하였으며 total organic carbon (TOC)와 탁도를 측정하여 특성을 분석하였다. 제거율 확인결과 탁도가 TOC와 동일한 경향성을 나타내는 것이 확인되었다. 따라서 본 연구에서는 고분자의 방사조건과 염의 유무에 따른 분리막의 섬유 형상과 물리적 특성변화와 이를 이용한 유수분리 특성에 대해 연구하였다.

PURPOSES : In this study, the installation standards for micro-roundabouts at the intersection of local streets with two entering lanes of a 3.0 m lane width were developed. METHODS : The inscribed circle diameter where a design standard vehicle could turn around safely based on the lane width and speed was analyzed using AutoTURN software. A total of 864 analysis scenarios for different entering volume and left-turning ratio (10%, 20%, 30%, and 40%), intersection type (three-way and four-way), heavy vehicle ratio (0%, 5%, and 10%), and circle lane turning speed (10, 15, and 20 km/h) conditions were established and evaluated. VISSIM Micro-Simulation was used to estimate the entering volume for microroundabouts with LOS C. RESULTS : The results showed that the estimated entering volumes of the three-way and four-way micro-roundabouts with LOS C were 300~400 and 200~400 vehicle/hour/lane, respectively. CONCLUSIONS : It is demonstrated that the standard volume of entering vehicles for micro-roundabouts is approximately 200 vehicle/ hour/lane, considering the number of approach lanes, designed speed of circulating lanes, left turn ratio, and heavy vehicle ratio.

This paper presents a Raman spectroscopy study of the influence of methane flow on the micro-tribological behavior of diamond-like carbon coatings deposited with an industrial plasma-enhanced chemical vapor deposition system. Results have shown a direct relationship between the methane flow and thickness of the coatings. The analysis of the Raman spectra and deposition parameters allowed establishing the influence of H content with the methane flow, the disorder level and estimation of the sp3 fraction on the carbon coatings. The micro-tribology tests showed a strong dependence of the wear resistance and hardness with Raman parameters. The coating deposited at 72-sccm methane flow presented a thickness of 1.7 μm and a sp3 fraction of 0.33. This sp3 fraction gave rise to a hardness of 24 GPa and an excellent wear resistance of 3.3 × 10–6 mm3 N−1 mm−1 for this DLC coating. Wear tests showed a swelling in the wear profiles on this coating, which was associated with the occurrence of a re-hybridization process.

In-situ carbon-coated tin oxide (ISCC-SnO2) was fabricated by colloidal processing and sucrose was used as a soluble carbon source. ISCC-SnO2 was characterized by X-ray diffraction (XRD), Raman spectroscopy, and nitrogen adsorption–desorption by BET methods, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Cyclic voltammetry (CV) and galvanostatic charge–discharge (GCD) properties of ISCC-SnO2 were investigated in 1 M Na2SO4 solution. The specific capacitance of ISCC-SnO2 was achieved 42.7 mFcm−2 at a scan rate of 25 mVs−1 and showed excellent charge–discharge behavior.

In this study, visualization of droplet impact on hydrophobic micro-, micro/nano-textured surfaces and lubricant infused surfaces was performed. Experimental specimens were fabricated using MEMS (micro- electromechanical systems) techniques and droplet impact with pure water was visualized at various Weber number range (2 < We < 200) using a high speed camera at 8000 frames per second. Through this study it was confirmed that, various droplet impact behaviors were appeared as the Weber number was increased and the Weber number at which droplet impact behavior changes was affected by surface characteristics. Particularly, on the lubricant infused surface (LIS) after droplet impact retraction velocity is reduced by the lubricant viscosity effect during contraction process of droplet to improve the droplet deposition behavior on the surface. It was confirmed that droplet break up phenomena caused interfacial instability was slightly delayed on LIS due to the viscous dissipation effect during droplet impact process.

This study examined the combined effects of high hydrostatic pressure (HHP) and micro-perforated (MP) film packaging on the microbiological and physicochemical qualities of kimchi sauce stored under fluctuating temperature conditions. Before storage, treatment with 600 MPa HHP reduced the total lactic acid bacteria in the sauce samples to below the detection limit (1 log CFU/g). After 68-day storage, ten microbial strains isolated from the non-treated controls were identified as Pediococcus pentosaceus, whereas eight microbial strains isolated from the HHP-treated samples were identified as Bacillus spp., regardless of the packaging type. Additionally, the samples treated with HHP and packaged in a multilayer film bag (ML-HPP), as well as those in the MP-HHP group, exhibited higher pH values and reduced sugar content than the ML-control or MP-control after 68-day storage. No significant differences were observed between the control and treatment groups regarding their electrical conductivity, salinity, and CIE a* values at the end of storage. However, there was no O2 reduction or CO2 accumulation in the MP-HHP group after 68-day storage. These results indicate that the combination of HHP treatment and MP-film packaging can extend the kimchi sauce's shelf life without packaging expansion during long-term storage.

Mass mortality of mariculture fish due to high summer temperatures is a major issue in the mariculture industry in many coastal waters of Korea, yet measures to mitigate the impact are generally limited. We injected a micro-bubble of liquefied oxygen into the bottom of rockfish cages (about 6-8 m deep) in order to maximize the dispersal of micro-bubbled seawater and reduce fish mortality. The injection of low-temperature oxygen in micro-bubbles lowered the water temperature at the injection area by as much as 1℃ and increased dissolved oxygen concentration by 0.5 ppm. In early August, following a week with persistent high water temperature (above 28.5℃), there was an increase in fish mortality despite the micro-bubble system, which resulted in approximately 7% death of the total introduced fish population. However, this mortality appeared to be much lower than mortality reported in a neighboring mariculture facility (approximately 50% mortality). We also estimated the volume that can be recirculated with pumped seawater using a micro-bubble system. We suggest that this approach of injecting liquefied oxygen through a micro-bubble system may reduce fish mortality during high temperature periods.