This study is to investigate the effect of material for GPF on the PM reduction characteristics before the improvement of filter efficiency in GPF. The material of GPF was changed to ceramic and metal. The ceramic material was applied to SiC, and the metal materials were employed to STS 310s, STS 316s, and STS 410s. The number of honeycomb and wall thickness were set to 200CPSI, 0.3987mm, respectively. The inlet mass flow was fixed at 0.00695kg/s. The inlet air temperature was changed from 500K(0s∼350s) to 1000K(400s∼900s). It was found that the differences in loading amount according to the GPF materials were difficult to observe because the pore density and porosity were set to be the same to affect only the mechanical properties. STS 310s with the highest temperature value had the fastest regeneration time. However, as time goes on, SiC had the highest regeneration rate characteristics. The reason is that the high-temperature region in the GPF by the high-temperature exhaust gas was rapidly transferred toward the outlet due to the high thermal conductivity of SiC.

본 연구에서는 방사성동위원소 추적자 실험을 통해서 산화아연 또는 두 종류의 은나노물질로 오염시킨 토양에서 지렁이 (Eisenia fetida)의 금속축적과 제거율을 비교하였고, 이들을 이온상의 Ag와 Zn으로 처리한 대조구와 비교하였다. 추가적으로 토양의 금속을 다단계추출법 (sequential extraction method)을 이용하여 금속의 결합 형태로부터 생물이용도 (bioavailability)를 예측하고 실제 생물축적 (BAF, bioaccumulation factor)과 비교하였다. ZnO 처리구의 BAF (0.06)는 아연이온 처리구 BAF (1.86)보다 31배 낮았는데, 이는 토양에서 ZnO의 생물전이가 매우 낮음을 제시해 준다. 한편, 은의 BAF는 금속의 오염 형태에에 무관 하게 0.11~0.17의 범위를 보였다. 다단계추출법을 통해서 아연이온 처리구의 아연은 토양에 비교적 약한 결합을 하 는 형태 (mobile fraction)에 35% 분포하여 아연이온처리구 값 (<20%)보다 높았고, 이는 전자의 더 높은 BAF와 일치 한다. 하지만, ZnO 처리구의 다단계추출은 생물이용도나 BAF를 잘 예측하지 못했으며 이는 ZnO가 토양에서 아연 이온과 지화학적으로 다른 거동을 하기 때문으로 추정된다. 지렁이 체내에 축적된 은의 제거율 (3.2~3.8% d-1)은 아연의 제거율 (1.2~1.7% d-1)보다 2~3배 더 높았다

This review summarizes the recent progress in iron-oxide-based heat generators. Cancer treatment using magnetic nanoparticles as a heat generator, termed magnetic fluid hyperthermia, is a promising noninvasive approach that has gained significant interest. Most previous studies on improving the hyperthermia effect have focused on the construction of dopant-containing iron oxides. However, their applications in a clinical application can be limited due to extra dopants, and pure iron oxide is the only inorganic material approved by the Food and Drug Administration (FDA). Several factors that influence the heat generation capability of iron-oxide-based nanoparticles are summarized by reviewing recent studies on hyperthermia agents. Thus, our paper will provide the guideline for developing pure iron oxide-based heat generators with high heat dissipation capabilities.

Energy storage systems should address issues such as power fluctuations and rapid charge-discharge; to meet this requirement, CoFe2O4 (CFO) spinel nanoparticles with a suitable electrical conductivity and various redox states are synthesized and used as electrode materials for supercapacitors. In particular, CFO electrodes combined with carbon nanofibers (CNFs) can provide long-term cycling stability by fabricating binder-free three-dimensional electrodes. In this study, CFO-decorated CNFs are prepared by electrospinning and a low-cost hydrothermal method. The effects of heat treatment, such as the activation of CNFs (ACNFs) and calcination of CFO-decorated CNFs (C-CFO/ACNFs), are investigated. The C-CFO/ACNF electrode exhibits a high specific capacitance of 142.9 F/g at a scan rate of 5 mV/s and superior rate capability of 77.6% capacitance retention at a high scan rate of 500 mV/s. This electrode also achieves the lowest charge transfer resistance of 0.0063 Ω and excellent cycling stability (93.5% retention after 5,000 cycles) because of the improved ion conductivity by pathway formation and structural stability. The results of our work are expected to open a new route for manufacturing hybrid capacitor electrodes containing the C-CFO/ACNF electrode that can be easily prepared with a low-cost and simple process with enhanced electrochemical performance.

본 연구에서는 강화되는 황산화물 및 입자상물질의 배출규제를 만족시키기 위한 후처리장치로 습식전기집진기에 대한 실험적 연구를 수행하였다. 실험을 위해 선박용 중유(HFO, 황함유량 약 2.1%)를 연료로 사용하는 선박용 4행정 디젤엔진(STX-MAN B&W)을 활용 하였으며, 연돌에 설치된 습식전기집진기 입/출구에서 측정을 실시하였다. 미세먼지 측정을 위해서는 광학식 계측기(OPA-102) 및 중량농 도측정방식(Method 5 Isokinetic Train)을 이용하였으며, 황산화물 계측을 위해서는 FT-IR(DX-4000)을 사용하였다. 엔진부하는 50%, 75%, 100%로 변화시키면서 실험을 실시하였다. 실험 결과로, 엔진부하가 50%에서 100%로 변화함에 따라 미세먼지 저감 효율은 모든 부하 조건에서 94~98% 정도의 높은 저감 효율을 나타내었다. 추가적으로 습식전기집진기 퀜칭존에서 배기가스의 온도를 낮추는 과정 중 세정액에 의한 이산화황(SO2) 저감을 확인할 수 있었으며, 저감율은 엔진부하에 따라 55%~81%로 확인되었다.

Magnetic nanoparticles have a significant impact on the development of basic sciences and nanomedical, electronic, optical, and biotech industries. The development of magnetic structures with size homogeneity, magnetization, and particle dispersibility due to high-quality process development can broaden their utilization for separation analysis, structural color optics using surface modification, and energy/catalysts. In addition, magnetic nanoparticles simultaneously exhibit two properties: magnetic and plasmon resonance, which can be self-assembled and can improve signal sensitivity through plasmon resonance. This paper reports typical examples of the synthesis and properties of various magnetic nanoparticles, especially magnetoplasmonic nanoparticles developed in our laboratory over the past decade, and their optical, electrochemical, energy/catalytic, and bio-applications. In addition, the future value of magnetoplasmonic nanoparticles can be reevaluated by comparing them with that reported in the literature.

Here, we report the development of a new and low-cost core-shell structure for lithium-ion battery anodes using silicon waste sludge and the Ti-ion complex. X-ray diffraction (XRD) confirmed the raw waste silicon sludge powder to be pure silicon without other metal impurities and the particle size distribution is measured to be from 200 nm to 3 μm by dynamic light scattering (DLS). As a result of pulverization by a planetary mill, the size of the single crystal according to the Scherrer formula is calculated to be 12.1 nm, but the average particle size of the agglomerate is measured to be 123.6 nm. A Si/TiO2 core-shell structure is formed using simple Ti complex ions, and the ratio of TiO2 peaks increased with an increase in the amount of Ti ions. Transmission electron microscopy (TEM) observations revealed that TiO2 coating on Si nanoparticles results in a Si-TiO2 core-shell structure. This result is expected to improve the stability and cycle of lithium-ion batteries as anodes.

물 여과, 단백질 정제 또는 생체 의학 여과 장치에 사용되는 분리막은 여러 가지 이유로 막 파울링을 거치게 된다. 박테리아에 의한 막 표면의 바이오필름 형성은 분리막의 내구성에 심각한 문제를 초래한다. 단백질 정제의 경우, 소수성 인 막의 표면으로 인해 막의 기공이 막히게 된다. 분리막의 파울링을 조절하는 방법에는 여러 가지가 있는데, 그 중 하나가 은나노 입자의 도입이다. 은나노 입자의 항균 특성은 잘 알려져 있고 따라서 여러 응용에 사용되고 있다. 본 총설에서는 은나 노 입자 또는 그 유도체가 박막 활성층에 도입되거나 또는 복합막 전체에 균일하게 분포된 분리막에 초점을 두었다.

Carbon-encapsulated Ni catalysts are synthesized by an electrical explosion of wires (EEW) method and applied for CO2 methanation. We find that the presence of carbon shell on Ni nanoparticles as catalyst can positively affect CO2 methanation reaction. Ni@5C that is produced under 5% CH4 partial pressure in Ar gas has highest conversions of 68 % at 350 oC and 70% at 400 oC, which are 73 and 75% of the thermodynamic equilibrium conversion, respectively. The catalyst of Ni@10C with thicker carbon layer shows much reduced activity. The EEW-produced Ni catalysts with low specific surface area outperform Ni catalysts with high surface area synthesized by solution-based precipitation methods. Our finding in this study shows the possibility of utilizing carbon-encapsulated metal catalysts for heterogeneous catalysis reaction including CO2 methanation. Furthermore, EEW, which is a highly promising method for massive production of metal nanoparticles, can be applied for various catalysis system, requiring scaled-up synthesis of catalysts.

Cooking, especially meat and fish grilling, is one of the representative sources of indoor and outdoor particulate matter (PM). Most of PM emitted from cooking is ultrafine dust (PM2.5). Since odorous organic acids, aldehydes, and volatile organic compounds are absorbed by PM and discharged, restaurants and food service industries are major sources of odorous PM emission that cause odor nuisance complaints in cities. PM emitted from cooking also contains polycyclic aromatic hydrocarbons (PAHs), which are carcinogens. In this paper, the domestic PM emission status of biomass combustion, especially meat and fish grilling, was analyzed temporally and spatially. The results of previous studies on PM emission concentrations, emission rates, emission factors and their compositions from cooking were comprehensively summarized. In addition, the effects of food ingredient types, cooking methods, seasoning and oil addition and fuel types on the PM emission were reviewed. Much more PM was produced when cooking with charcoal rather than electricity or gas. The higher the fat content of food ingredients such as intestines, the higher the PM emission concentration and emission rate. There was a difference in the PM emissions depending on the cooking oil types, and the PM emission concentration was high when olive oil or corn oil was used. It is necessary to accumulate more information through followup studies on the emission concentrations, emission factors and properties of PM emitted from cooking activities. This information can be used for controlling odorous PM in restaurants and food service industries, and predicting the impacts of odorous PM on air quality and human health.

본 연구에서는 피부 보습 및 진정효능을 갖는 비타민 B5인 Pantothenic acid (PA)의 피부 투과율을 개선시키기 위해 고형지질나노입자(SLN)를 설계하였다. SLN은 지질과 유화제의 종류를 변화하여 여러 조성으로 제조하였고, PA는 이중 에멀젼 가온 용융유화법으로 SLN 내에 봉입하였다. 제조 된 PA 봉입 SLN은 입자의 물리화학적 특성인 입자크기, 다분산 지수, 제타전위, 봉입율을 평가하였다. 피부 투과시험의 경우 인체 유래 인조 피부 조직을 사용하였다. 제조 된 PA 봉입 SLN의 입자크기는 192.15 – 369.87 nm이었고, 제타전위는 –21.39 - -40.55 mV이었다. SLN 내 PA의 평균 봉입효율은 44.36 – 57.16%이었고, 평균 봉입율은 12.60 – 16.36%이었다. PA 봉입 SLN의 피부 투과 결과는 SLN을 적용한 제형이 적용하지 않은 PA 용액 보다 약 3.8 – 8.8 배 PA의 피부 투과율이 개선되었다. 본 연구에서 제조 된 SLN은 PA의 피부 투과율을 개선하였음을 보여주었다. 특히, glyceryl behenate와 Span 60을 사용한 SLN이 PA의 피부 투과율이 가장 높은 결과를 보여 주었다.

Tungsten disulfide (WS2), a typical 2D layerd structure, has received much attention as a pseudocapacitive material because of its high theoretical specific capacity and excellent ion diffusion kinetics. However, WS2 has critical limits such as poor long-term cycling stability owing to its large volume expansion during cycling and low electrical conductivity. Therefore, to increase the high-rate performance and cycling stability for pseudocapacitors, well-dispersed WS2 nanoparticles embedded in carbon nanofibers (WS2-CNFs), including mesopores and S-doping, are prepared by hydrothermal synthesis and sulfurizaiton. These unique nanocomposite electrodes exhibit a high specific capacity (159.6 F g−1 at 10 mV s−1), excellent high-rate performance (81.3 F g−1 at 300 mV s−1), and long-term cycling stability (55.9% after 1,000 cycles at 100 mV s−1). The increased specific capacity is attributed to well-dispersed WS2 nanoparticles embedded in CNFs that the enlarge active area; the increased high-rate performance is contributed by reduced ion diffusion pathway due to mesoporous CNFs and improved electrical conductivity due to S-doped CNFs; the long-term cycling stability is attributed to the CNFs matrix including WS2 nanoparticles, which effectively prevent large volume expansion.