In this work, the sulfonic acid group was introduced into the resorcinol–formaldehyde (RF) microspheres by the addition of p-phenolsulfonic acid during the polycondensation process of RF. The hydrophilicity of the sulfonated RF allowed KOH to infiltrate inside the microspheres, which enhanced the formation of mesopores in the carbon microspheres during the activation process by KOH. SEM and TEM observations and N2 adsorption measurements verified the formation of abundant mesopores in the porous carbon microspheres. The BET surface area of these mesoporous carbons exceeded 2000 m2/ g. In 17 m NaClO4 “water-in-salt” (WIS) electrolyte-based supercapacitor, the synthesized mesoporous carbon exhibited high specific capacitance of 170 F/g at current density of 0.5 A/g, comparable to those in regular KOH electrolyte. When graphite was used as current collectors, the symmetric cell could operate at 2.5 V, and the mesoporous carbon exhibited an energy density of 43 Wh/kg at power density of 0.25 kW/kg, and 25 Wh/kg at power density of 6.25 kW/kg, respectively, which were superior to those using Pt or stainless steel as current collectors. The mesoporous carbon/graphite was an excellent electrode in new-generation “WIS” electrolyte-based high-voltage supercapacitor due to their high energy and power density.

High voltage impulse (HVI) has been gained attention as an alternative technique that could control the CaCO3 scale problems encountered in water main, pipe, cooling tower and heat exchanger vessels. The aim of this study was to investigate the effect of electric field (E) and contact time (t) of HVI on reduction of Ca2+ concentration at two different temperatures of 25℃ and 60℃. A kinetic model on the effect of E and t was investigated too. As the E and t increased, the Ca2+ concentration decreased more than that of the control (= no HVI). The Ca2+ concentration decreased up to 81% at 15 kV/cm at 60℃, which was nearly 2 times greater than the control. With these experimental data-set of reduction of Ca2+ concentration under different E and t, the kinetic model was developed. The relationship between E and t required to reduce the concentration of Ca2+ by 30% was modeled at each temperature. The empirical model equations were; E0.83· t = 60.3 at 25℃ and E0.08· t = 1.1 at 60℃. These equations state the products of En and t is always constant, which means that the required contact time can be reduced in accordance with the increment of E and vice versa.

Although membrane bio-reactor (MBR) has been widely applied for wastewater treatment plants, the membrane fouling problems are still considered as an obstacle to overcome. Thus, many studies and commercial developments on mitigating membrane fouling in MBR have been carried out. Recently, high voltage impulse (HVI) has gained attention for a possible alternative technique for desalting, non-thermal sterilization, bromate-free disinfection and mitigation of membrane fouling. In this study, it was verified if the HVI could be used for mitigation of membrane fouling, particularly the internal pore fouling in MBR. The HVI was applied to the fouled membrane under different conditions of electric fields (E) and contact time (t) of HVI in order to investigate how much of internal pore fouling was reduced. The internal pore fouling resistance (Rf) after HVI induction was reduced as both E and t increased. For example, Rf decreased by 19% when the applied E was 5 kV/cm and t was 80 min. However, the Rf decreased by 71% as the E increased to 15 kV/cm under the same contact time. The correlation between E and t that needed for 20% of Rf reduction was modeled based on kinetics. The model equation, E1.54t = 1.2 × 103 was obtained by the membrane filtration data that were obtained with and without HVI induction. The equation states the products of En and t is always constant, which means that the required contact time can be reduced in accordance with the increase of E.

A stacked high-voltage (900 V) Al electrolytic capacitor made with ZrO2 coated anode foils, which has not been studied so far, is realized and the effects of Zr-Al-O composite layer on the electric properties are discussed. Etched Al foils coated with ZrO2 sol are anodized in 2-methyl-1,3-propanediol (MPD)-boric acid electrolyte. The anodized Al foils are assembled with stacked structure to prepare the capacitor. The capacitance and dissipation factor of the capacitor with ZrO2 coated anode foils increase by 41 % and decrease by 50 %, respectively, in comparison with those of Al anode foils. Zr-Al- O composite dielectric layer is formed between separate crystalline ZrO2 with high dielectric constant and amorphous Al2O3 with high ionic resistivity. This work suggests that the formation of a composite layer by coating valve metal oxide on etched Al foil surface

Recently, applications of high voltage impulse (hereafter HVI) technique to desalting, sludge solubilization and disinfection have gained great attention. However, information on how the operating condition of HVI changes the water qualities, particularly production of hydroxyl radical (·OH) is not sufficient yet. The aim of this study is to investigate the effect of operating conditions of the HVI on the generation of hydroxyl radical. Indirect quantification of hydroxyl radical using RNO which react with hydroxyl radical was used. The higher HVI voltage applied up to 15 kV, the more RNO decreased. However, 5 kV was not enough to produce hydroxyl radical, indicating there might be an critical voltage triggering hydroxyl radical generation. The concentration of RNO under the condition of high conductivity decreased more than those of the low conductivities. Moreover, the higher the air supplies to the HVI reactor, the greater RNO decreased. The conditions with high conductivity and/or air supply might encourage the corona discharge on the electrode surfaces, which can produce the hydroxyl radical more easily. The pH and conductivity of the sample water changed little during the course of HVI induction.

Several disposal processes for waste sludge from wastewater treatment plants such as landfill, ocean dump, incineration, reuse as fuels or fertilizers are practiced. However, ocean dumping is prohibited by international treat. New constructions of landfill sites or incineration facilities are limited by NIMBY and reuse processes are still suffering from low energy yield. Therefore, development of alternative processes for sludge disposal are currently needed. In this study, alternative technique for sludge solubilization using HVI (high voltage impulse) was suggested and verified experimentally. Sludge solubilization was carried out for 90 minutes using HVI discharge with peak voltage of 16 kV and pulse duration for 40 microsecond. About 3∼9 % of MLSS and MLVSS concentration were reduced, but the soluble COD, TN, TP of the sludge increased to 372 %, 56 % and 102 % respectively. It indicates that the flocs and/or cells of the sludge were damaged by HVI. These resulted in flocs-disintegration and cells-lysis, which means the internal matters were bursted out of the flocs as well as the cells. Thus, electrical conductivity in bulk solution was increased. All of the results verified that the HVI could be used as an alternative technique for sludge solubilization processes.

기존의 기술 진화 경로 연구는 주로 거시적 동향 분석 수준에서 이루어져 왔으 며 포괄적인 기술정책 방향 수립에는 시사점이 있었으나, 기업 기술 및 특허전략에는 활용 가치가 낮았다. 2000년대부터 논문 및 특허 등의 데이터를 활용해 미시적인 기술의 진화 경 로를 분석하고, 기업 기술전략에 적용하려는 연구가 증가하고 있다. 그러나 대부분 과거 진 화 경로의 서술에 그치고 있으며 기술의 진화 또는 파생-융합 등의 변화에 대한 분석은 전문 가의 정성적 판단에 상당부분 의존하고 있다. 본 연구에서는 특허 인용 네트워크를 구축해 미시적 기술의 진화 경로를 도출하고, 기술의 진화와 파생을 동적 기술트리를 통해 분석하는 방법론을 제시한다. 동적 기술트리 분석은 기술의 핵심요소를 체계화하고, 신기술 요소의 신 규성과 확장성을 평가해 차세대 기술진화와 파생에 대한 정량적 판단을 가능하게 한다. 이를 통해 차세대 신기술과 파생기술에 대하여 파악, 평가, 비교하고 나아가 예측의 토대를 구축 한 것이 본 연구의 의의이다. 본 연구의 결과는 기술 및 특허전략과 포트폴리오 구축의 신뢰성을 높일 수 있는 좋은 도구가 될 것이다. 본 연구에서 제안한 방법론을 이용하여 최근 전력 산업에서 기존 교류 송전의 대안으로 주목을 받고 있는 초고압 직류송전 시스템 기술을 대상 으로 실증분석을 수행하였다.

A study on cluster ionizer for passenger automotive. This study is technical study which is performance, reliability, manufacturing method and productivity of cluster ionizer. Cluster ionizer function is comfortable compartment which eliminated of anti-virus, ordor, etc. This study on cluster ionizer which is manufacturing method, performance, reliability, production technology is mass production for automotive

본 논문에서는 Pothead를 지지하는데 사용하는 지그의 고유진동수를 일정 범위로 제한하여 Pothead와 공진을 일으키지 않도록 하는 지그의 최적 설계안을 제시한다. 쿤 터커(Kuhn-Thucker) 조건을 적용한 최적기준법(Optimality criteria method)을 사용하여 위상 최적화를 수행하였고, 이 과정에서 유한요소 크기기 최적 형상에 미치는 영향을 검토하였다. 또한 위상 최적화 결과를 바탕으로 실험 계획법(Design of experiments)과 반응 표면법(Response surface method)을 사용하여 형상 및 치수 최적화를 수행하여 비교용 지그에 비해 전체 질량이 30% 감소되는 결과를 얻었다. 마지막으로 최적화된 지그의 내진 해석을 수행한 Pothead의 응답은 Metal Handbook에서 제시된 내진 응답을 만족하고 있다.

Pulsed electronic field(PEF) 처리에 의한 우유 단백질과 물리화학적 특성의 변화를 확인하기 위하여 원유, 탈지유, HTST, LTLT, UHT 우유를 PEF 처리하였다. 시료 중의 단백질을 SDS-PAGE로 확인하였을 때, PEF 처리에 의한 우유 단백질의 변성은 관찰할 수 없었다. Differential scanning calorimetry(DSC)로 우유 단백질의 열변성 정점 온도(Td)를 분석한 결과, 탈지유를 65oC에서 PEF 처리하였을 때 Td가 87.66oC에서 97.18oC로 증가하여 PEF 처리가 우유 단백질의 변성에 영향을 미치는 것을 확인하였다. PEF 처리에 의한 alkaline phosphatase, protease, lactoperoxidase의 잔존효소활성을 측정한 결과, 원유와 탈지유에서 alkalinephosphatase는 PEF 처리에 의해 효소활성이 감소하였다. 또한 protease와 lactoperoxidase의 활성은 PEF 처리에 의해 영향을 받지 않았다. 65oC에서 PEF 처리한 원유는 처리하지 않은 원유보다 높은 갈색도를 나타내었으나, 기타 우유는 PEF에 의한 유의적인 차이가 없었다. 우유를 PEF 처리하였을 경우 산도의 변화는 관찰되지 않았고 pH의 경우에도 PEF 처리 여부에 따라 유의적인 차이는 있었으나 크게 변화하지는 않았다.

회분식 고전압 펄스 전기장 처리에 의한 막걸리의 비가열 살균 공정 적용의 가능성을 알아보았다. 막걸리의 초기 균수는 약 2×108 CFU/mL로 전기장의 세기와 처리시간이 증가할수록 사멸율은 증가하여, 30 kV/cm, 256 pulse 처리하였을 경우 약 2 log 정도의 사멸율을 나타내었다. 고전압 펄스 전기장과 열을 병합처리하였을 경우 50oC에서 20 kV/cm, 256 pulse 처리를 한 후 8 log의 높은 사멸율을 나타내었으며, 알코올 농도를 달리하였을 경우 알코올 농도가 높아질수록 높은 사멸율을 나타내어 12%의 알코올 농도에서 4.8 log의 사멸율을 보였다. 고전압 펄스 전기장 처리한 막걸리를 4oC와 30oC에서 4주간 저장하였을 경우 무처리막걸리에 비하여 4oC에서는 pH, 산도, 미생물의 수에 변화가 거의 없었으며, 30oC에서도 적정산도나 미생물의 증가가 일정 수준이하로 억제되어 막걸리의 비가열 살균 공정으로서의 가능성을 보였다.

The purpose of this study was to minimize of entrance surface dose (ESD) at the eye using high kVp technique in the computed radiography. We used REX-650R (Listem, Korea) general X-ray unit, and external detector with ESD dosimeter of Piranha 657 (RTI Electronics, Sweden). We used head of the whole body phantom. The total 64 images of X-ray anterior-posterior of skull were acquired using the film/screen (F/S) method and the digital of computed radiography method. The three radiology professor of more 10 years of clinical career evaluated a X-rays images in the same space by 5-point scale. The external detector was performed measurement of ESD of three times by same condition on the eye of the head phantom. The good image quality in the F/S method (90 kVp, 2.5 mAs) showed at the minimized ESD of 0.310 ± 0.001 mGy. the good image quality in the computed radiography method (90 kVp, 2.0 mAs) showed at the minimized ESD of 0.180 ± 0.002 mGy (P = 0.002). Finally the radiation dose could reduced about 50% in the computed radiography method more than the F/S method. In addition the eye entrance surface dose using high kVp technique with the computed radiography was reduced 92% more than conventional technique (F/S method).