Electrical, Thermal, and Thermoelectric Transport Properties of Se-doped Polycrystalline Re2Te5

Se Woong Lee,Okmin Park,Hyun-Sik Kim,Won-Seon Seo,Sang-il Kim 대한금속·재료학회 2022 대한금속·재료학회지 Vol.60 No.12

Re2Te5 is considered a potential thermoelectric material because of its intrinsically low thermalconductivity, due to its complex crystal structure. Herein, a series of Se-doped Re2Te5 (Re2Te5-xSex, x = 0, 0.2,1, and 2) samples were synthesized, and their electrical and thermal transport properties were investigated. Pure orthorhombic Re2Te5 phases were successfully synthesized without any impurities for all compositions,and the continuous decrease in the calculated lattice parameters confirmed the substitution of Se atoms atthe Te sites. A maximum power factor of 0.135 mW/mK2was achieved for the sample with x = 0.2 at 880 K,mainly due to the increase in carrier concentration and electrical conductivity. The lattice thermalconductivity significantly decreased for all doped samples, which was attributed to the point defect phononscattering caused by Se doping. The thermoelectric figure of merit, zT reached a maximum value of 0.20 at880 K for Re2Te4.8Se0.2 (x = 0.2) sample, which was approximately 22% higher than that of the pristine Re2Te5sample. The weighted mobility, quality factor, and expected zT were calculated to evaluate the optimizationof the power factor and zT.

Improved Internal Quantum Efficiency and Light-Extraction Efficiency of Organic Light-Emitting Diodes via Synergistic Doping with Au and Ag Nanoparticles

Cho, Changsoon,Kang, Hyunbum,Baek, Se-Woong,Kim, Taesu,Lee, Changyeon,Kim, Bumjoon J.,Lee, Jung-Yong American Chemical Society 2016 ACS APPLIED MATERIALS & INTERFACES Vol.8 No.41

<P>This paper reports the distinct roles- of Au and Ag nanoparticles; (NPs) in organic light-Orating-diodes (OLEDS) depending on their sizes. Au and Ag-NPs that.are 40 arid 50 nm in size, respectively, are the most effective for enhancing the performance of green: OLEDs. The external quantum efficiencies (EQEs): of green OLEDs doped with An and Ag N.Pg, (40 and 50 rim, respectiVely) are improved by 29.5% and 36.1%, respectively, while the power. efficiencies (PE8) are enhanced by 47.9% and 37.5%, respectively. Furthermore, combining the Au and Ag NPs produces greater enhancements. The EQE and PE of the coci-oped OLEDs are improved by 63.9% and 68.8% respectively,-.through the synergistic behavior of the different NPs. Finite difference time-domain simulations confirm that the localized surfaee:plasmon resonance of the Au NPs near 580 nth improves the radiative recombination rate (k(rad)) of green-light emitters locally (<50 pm), while the Ag NPs cause relatively long, range and broadband enhancements in k(rad). The-Simulations of 'various domain sizes. Verify that the light-extraction efficiency (LEE),can, be enhanced by More than 4.2% by applying Ag NPS.. Thus, size-controlled Au and Ag NPs can synergistically enhance LEDS by improving both the internal quantum efficiency and LEE.</P>

BEZ235 (PIK3/mTOR inhibitor) Overcomes Pazopanib Resistance in Patient-Derived Refractory Soft Tissue Sarcoma Cells

Kim, Hee Kyung,Kim, Sun Young,Lee, Su Jin,Kang, Mihyeon,Kim, Seung Tae,Jang, Jiryeon,Rath, Oliver,Schueler, Julia,Lee, Dong Woo,Park, Woong Yang,Kim, Sung Joo,Park, Se Hoon,Lee, Jeeyun Neoplasia Press 2016 Translational oncology Vol.9 No.3

<P><I>BACKGROUND:</I> Although pazopanib treatment has become the standard chemotherapy in salvage setting for metastatic sarcoma patients, most patients progress after pazopanib treatment in 4 to 6 months. After failure to pazopanib, patients have limited options for treatment. Therefore, subsequent therapy in patients who failed to pazopanib is urgently needed and the use of patient derived cells or patient derived tumors for accompanying testing with various pharmacological inhibitors could offer additional treatment options for these patients. <I>METHODS:</I> Patient derived tumor cells were collected from ascites at the time of progression to pazopanib and a 13-drug panel was tested for drug sensitivity. We confirmed the results using <I>in vitro</I> cell viability assay and immunoblot assay. We also performed the genomic profiling of PDX model. <I>RESULTS:</I> The growth of patient derived tumor cells was significantly reduced by exposure to 1.0 μM AZD2014 compared with control (control versus AZD2014, mean growth = 100.0% vs 16.04%, difference = 83.96%, 95% CI = 70.01% to 97.92%, <I>P</I> = .0435). Similarly, 1.0 μM BEZ235 profoundly inhibited tumor cell growth <I>in vitro</I> when compared to control (control versus BEZ235, mean growth = 100.0% vs 7.308%, difference = 92.69%, 95% CI = 78.87% to 106.5%, <I>P</I> < .0001). Despite the presence of CDK4 amplification in the patient-derived tumor cells, LEE011 did not considerably inhibit cell proliferation when compared with control (control vs LEE011, mean growth = 100.0% vs 80.23%, difference = 19.77%, 95% CI = 1.828% to 37.72%, <I>P</I> = .0377). The immunoblot analysis showed that BEZ235 treatment decreased pAKT, pmTOR and pERK whereas AZD2014 decreased only pmTOR. <I>CONCLUSION:</I> Taken together, upregulation of mTOR/AKT pathway in sarcoma patient derived cells was considerably inhibited by the treatment of AZD2014 and BEZ235 with downregulation of AKT pathway (greater extent for BEZ235). These molecules may be considered as treatment option in STS patient who have failed to pazopanib in the context of clinical trials.</P>

位相差 檢出方式을 利用한 토크미터에 대한 實驗的 考察

이종원,오세훈,김지웅,이준환 중앙대학교 생산공학연구소 1999 생산공학연구소 논문집 Vol.8 No.2

본 연구에서는 기존의 토크미터의 기계적 특성을 높이기 위하여 STS 304와 복합재료를 회전축에 사용한 위상차 검출방식의 토크미터를 개발하였다. 실험결과, 동시접합방식을 이용하여 제작된 토크미터 회전축의 기계적 특성이 다른 방식으로 제작된 것보다 우수한 것으로 나타났다. 유리강화복합재료의 적충각이 30˚, 동시 접합방식으로 접합된 토크미터 회전축의 고유진동수와 반경방향 강성은 STS304재질만을 이용하여 제작된 회전축보다 각각 64%, 137% 증가되어지는 것을 실험을 통해 증명하였다. In this study the angular twist type torque-meter was designed and manu factured with STS 304 and fiber-feinforced composite materials to improve the dynamic properties of the existing torque-meter. From the experimental and analytical results, it was found that the dynamic characteristics of co-cured bonded torque-meter rotating shaft were better than those of the adhesively and unreinforced torque-meter rotating shaft. For the torque-meter rotating shaft manufactured by co-cured bonded with kthe glass fiber-epoxy composite and with a stacking sequence of [±30˚/STS304]??, the natural frequency and the radial stiffness were increased by 64% and 137% compared to those of the unreinforced torque-meter rotating shaft.

각속도 변동 지수와 크랭크각 지수를 이용한 가솔린 기관의 실화 검출

이근봉,김세웅,심국상 國立金烏工科大學校附設生産技術硏究所 1997 産業技術開發硏究 Vol.13 No.-

This paper introduces a diagnostic technique for the detection of faulty cylinders of internal combustion engines, using the indexes of the angular velocity variation and the crankshaft angle. Many types of faults may occur during the operation of internal combustion engines. These include low compression pressure, failure of ignition or combustion of malfunction of the fuel system. Early detection and correction of engine faults restore proper performance, improve engine efficiency and reduce costs. From the idea that the fluctuation of crankshaft speed contains the information of combustion phenomena, angular velocity variation is measured, with an interval timer and a magneric pick-up sensor, by timing the flywheel gear teeth as they pass the sensor. The angular velocity and angular acceleration are determined by cylinder pressure, load, inertia, and friction of the engine. The angular acceleration patterns, as well as the velocity patterns, are varied according to the relative effects between cylinder pressure and reciprocating inertia. Therefore the patterns are classified into three regions; the inertia dominant region, the combined region, the pressure dominant region. In this paper, misfire detection was investigated according to the regions with parameters defined for misfire detection. By this method, the single misfire or multiple misfires can be detected

Electrosurgery를 이용한 치료증례

이상훈,이광수,한세현,윤재웅 大韓小兒齒科學會 1996 大韓小兒齒科學會誌 Vol.23 No.3

Electrosurgical technique have been used in dentistry as an aid to soft tissue management for nearly 60 years. However, it was not until the late 1960s that the principles of electrosurgery were understood and improved equipment became available. Electrosurgery is a surgical procedure performed on soft tissue utilizing controlled high frequency electrical(radio-frequency) currents in the range of 1,500,000 to 7,500,000 cyclesper second. The radio-frequency energy used in electrosurgery is able to cut and coagulate tissue because it focuses the energy at the small, active electrode. Advantages of electrosurgery for soft-tissue management during dental procedures include improved hemostasis, ease of tissue modification, improved visibility and so on, but adverse healing response-including necrosis of soft tissue and sequestration of alveolar bone-have been reported. The present report provides examples of treatment of soft tissue and pulp tissue of primary teeth by electrosurgery. The results are as follows ; 1. Electrosurgical techniques can be used for various procedures in pedodontics. 2. Electrosurgical procedures provide improved hemostasis and visibility in the operating field, which enable to remove, reshape, and contour soft tissues easily. 3. In pulpotomy technique, it was difficult to expect the variable pulpal response based on the degree of heat accumulation and the conditions of pulp tissues. Therefore, electrosurgical pulpotomy could not be considered as a method superior to formocresol pulpotomy. 4. A greater degree of dexterity and experiences in manipulation of the electrode is required compared with the conventional scalpel surgery.

광대역 고출력 공간 전력 증폭 소자에 관한 연구

이성호,권세웅,이병무,윤영중 연세대학교 산업기술연구소 2002 논문집 Vol.33 No.2

In this paper, spatial amplifier using wideband printed dipole antennas is proposed for spatial power combining. The input and output printed dipole antennas have wide bandwidth of 22 %(5.44 ㎓∼6.75 ㎓) and 26.3 %(5.2 ㎓∼6.78 ㎓), respectively. Gain of the designed amplifier is 9.5 ㏈ at 6 ㎓. As a result, the proposed spatial amplifier using wideband printed dipole antennas and amplifiers shows that the gain is 16.8 ㏈ at 6 ㎓ and 3-㏈ gain bandwidth is 1.04 ㎓.

결과지식의 정확성이 운동학습 효과에 미치는 영향

이세웅,박장평 江原大學校附設 體育科學硏究所 1992 江原大學校附設體育科學硏究所論文集 Vol.- No.17

The purpose of this study was to find out if there is any effect of the precision of knowledge of results on motor learning. Total twenty-four female students of middle school were used as subjects and divided into two groups, Quantitative KR and Qualitative KR. Each group consisted of twelve subject. The task of experiment was Liner Positioning task. The knowledge of results interval was fixed as immediately and post-knowledge of results in-terval was fixed as three seconds. As the results of experiment, the conclusions were made as follows : 1) Both quantitative KR and qualitative KR significantly have an effect on results of early performance. 2) In retention test to examine the ability of motor memory which is result of motor learning, quantivtative KR group is more excellent than Qualitative KR group and the effects are consistent.

구체물의 조작적 놀이활동이 정신지체 아동의 수 개념에 미치는 효과

오세웅,이명자 한국정신지체아교육학회 2003 지적장애연구 Vol.5 No.-

장애정도가 심한 정신지체 학생들도 일상의 생활에서 일어나는 수학적 문제를 스스로 해결하고 처리하는 기본적 생활 적응능력을 배양하도록 하기 위해서는 학생들의 발달적 순서에 맞는 수학의 논리적인 계열성에 따라 가능한 스물 스텝으로 단계화 한 프로그램을 조직하고, 학생들이 이해가 쉽도록 잘 번역되어야 하며, 개별학생들이 선호하는 구체물의 조작활동을 통하여 수학의 기초적 개념과 원리와 법칙을 이해시키고 이들의 학습실태를 계속적으로 진단 처방 평가하여 한 단계의 학습이 완전히 이루어진 후 다음 단계의 학습이 시도되는 진단 처방식 개별화 교육이 특수교육 현장에서 적극적으로 실천될 수 있는 방안이 모색되어져야 할 것이다. The study is performed to high school 7 students with severe mental retardation who have poor fingers abilities to facilities math problem solution themselves in society, and finally, to cultivate daily living skills. The students were divided into two groups, with competence, One were exposed to concept instruction program(Ⅰ), prior to acquire fingers through operation activities of concrete materials. Other were exposed to concept instruction program(Ⅱ) through operation activities of concrete materials, during 16 weeks. The conclusion drawn from the study were as fellows; First, Concept instruction program(Ⅰ) prior to acquire fingers through operation activities of concrete materials which individual prefer make develop to basic finger concept, and to abilities analyzing things as logic. Second, Concept instruction program(Ⅱ) through operation activities of concrete materials which individual prefer have an influence on application students with severe mental retardation to fingers.

공기 보조 분사 장치를 이용한 엔진 성능 향상 및 연비 개선

김세웅,심국상,이근봉 金烏工科大學校 1995 論文集 Vol.16 No.-

This paper describes the improvement of engine performence and fuel consumption through improved combustion formed by the tumble and swirl flows of an in-cylinder fuel-air mixture that uses an air forced fuel injector(AFI) which used compressed air. The AFI is designed to promote fuel atomization and to form uniform fuel-air mixture. In order to make up the tumble and the swirl flows of the in-cylinder mixture, the end of AFI is attached to the tube containing the fuel-air mixture to ensure the adequate flow and to ensure that the remaining kinds of mixture will flow effectively. In order to investigate the improvement of engine performence and fuel consumption, 2 models of tubes which make tumble and swirl flows were utilized. Each model was examined according to engine speed, intake manifold pressure and excess air ratio and compared with a base engine. Compared with the base engine, the results show that the AFI improves the engine performance and the brake specific fuel consumption(BSFC) in all of the engine speeds and the boost pressures at the tumble and the swirlflows. It also decreases exhaust emission of hydrocarbon(HC)