신기술 동향 : 원자층증착 기술의 특성 및 전망

김양도 한국공학교육학회 ( 구 한국공학기술학회 ) 2005 공학교육동향 Vol.12 No.3

Improvement of solar cell efficiency by applying Si3N4 nanopattern on glass substrate

김양도,신주현,오경석,이정철,이헌 한국물리학회 2014 Current Applied Physics Vol.14 No.9

A cylindrical Si3N4 nanopattern whose heights was 200 nm was fabricated on a glass substrate, and an aluminum-doped zinc oxide (AZO) layer was grown on the nanopatterned glass substrate. The nanopatternwas applied to an amorphous silicon solar cell in order to increase the light-scattering effect, thus enhancing the efficiency of the solar cell. The reflectance of the solar cell on the Si3N4 nanopattern decreased and its absorption increased. Compared to a flat substrate, the short-circuit current density (Jsc) and conversion efficiency of a solar cell on the Si3N4 nanopatterned substrate were improved by 17.9% and 24.2%, respectively, as determined from solar simulator measurements.

원자층증착 기술의 특성 및 전망

김양도 한국공학교육학회 2005 Ingenium(人材니움) Vol.12 No.3

Bacillus licheniformis Xylanase 의 정제와 특성

최양도(Yang Do Choi),한문희(Moon Hi Han),김진미(Jin Mee Kim) 한국미생물생명공학회 1983 한국미생물·생명공학회지 Vol.11 No.3

대학생의 거부민감성이 대인관계문제에 미치는 영향: 경험회피와 정서인식명확성의 매개효과

김아람,양도연,천성문 부경대학교 인문사회과학연구소 2022 인문사회과학연구 Vol.23 No.2

The purpose of this study is to investigate mediated effect of experiential avoidance and emotional clarity that comes from rejection sensitivity of the university student and their interpersonal relations difficulties. The subjects of this study were university students in four cities and they were asked about rejection sensitivity, interpersonal relations problems, experiential avoidance, and emotional clarity with questionnaire. Correlation analysis was conducted so as to examine interrelations of variables by using SPSS 22.0. The findings of this study are the following: First, rejection sensitivity of the university students influences directly on their interpersonal relations problems. Second, rejection sensitivity of the students has an effect on interpersonal relations problems by mediating experiential avoidance. Third, rejection sensitivity of the university students has an influence on interpersonal relations problems by mediating emotional clarity. Fourth, rejection sensitivity of the university students effects on interpersonal relations problems by successively mediating experiential avoidance and emotional clarity. These findings show that if a university student has high level of rejection sensitivity, the student will avoid the experience due to anxiety about rejection and have low level of emotional clarity, and in turn, it can give an effect on interpersonal relations problems. Thus, based on the findings, this study suggests that practical measures for reducing interpersonal relations difficulties of the university students should be discussed and if a university student client who reports interpersonal relations problems and is sensitive to rejection is faced in practical counseling, it is expected that the results of this study can help the student to adjust to interpersonal relations soundly through proper interventions of experiential avoidance and emotional clarity. 본 연구의 목적은 대학생의 거부민감성과 대인관계문제에서 경험회피와 정서인식명확성의 매개효과를 살펴보는데 있다. 이를 위해 본 연구에서는 전국 17개 시도 중 부산광역시, 경상남도, 서울, 경기도, 4개 시도에 소재한 대학에 재학중인 대학생 359명을 대상으로, 거부민감성, 대인관계문제, 경험회피, 정서인식명확성에 관한 설문을 실시하였고, 무성의하게 응답한 12부를 제외한 347부의 설문지를 사용하였다. SPSS 25.0을 사용하여 변인들 간의 관련성을 살펴보기 위해 상관분석을 실시하였고 Hayes(2013)가 제안한 매개모형의 절차에 따라 경로를 분석하여 매개효과를 확인하였다. 본 연구의 결과는 첫째, 대학생의 거부민감성이 대인관계문제에 직접적인 정적 영향을 미치는 것으로 나타났다. 이는 거부민감성이 높은 사람은 대인관계 속에서 더 많은 어려움을 경험하고 호소한다는 것을 의미한다. 둘째, 대학생의 거부민감성 경험회피를 매개로 대인관계문제에 영향을 미치는 것으로 나타났다. 이는 거부민감성이 높을수록 과도한 불안을 느껴 회피반응을 보여 대인관계가 여려워 지는 것으로 이해할 수 있다. 셋째, 대학생의 거부민감성은 정서인식명확성을 매개로 대인관계문제에 영향을 미치는 것으로 나타났다. 이는 거부민간성이 높을수록 정서를 명확하게 인식하고 파악하는 능력이 떨어져 대인관계에서도 부적절한 반응을 하는 것으로 볼 수 있다. 넷째, 대학생의 거부민감성은 경험회피와 정서인식명확성을 순차적 매개하여 대인관계 문제에 영향을 미치는 것으로 나타났다. 이러한 연구결과는 대학생이 거부민감성이 높을수록 타인의 거부반응에 예민하게 반응하여 경험을 회피하고 이로인해 고통스러운 정서나 생각을 지속적으로 피하게 되어 정서를 명확히 인식하지 못함으로써 대인관계문제에 영향을 줄 수 있음을 시사한다. 본 연구는 대학생 내담자의 대인관계문제를 감소시키기 위한 교육 및 상담 프로그램 개발의 기초자료로 활용될 수 있을 것이다.

Post Treatment of CdSe Nanoparticles Synthesized in Aqueous Solution by Using Thiol-Alcohol

김신호,김양도,Yong Jin Kim,Young Seok Kim 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.1

CdSe nanoparticles were prepared by using a simple route with Cd(NO3)2ㆍ4H2O and Na2SeSO3 in aqueous solution. Post surface modication of the CdSe nanoparticles by using thiol-alcohol was also performed to enhance the optical properties and to remove hydroxide (Cd(OH)2) impu- rities. CdSe nanoparticles synthesized in aqueous solution showed a zinc-blende structure and a homogeneous size distribution with a mean particle size of about 7 nm. The capping capability of 2-mercaptoethanol became active as the pH of the CdSe colloid approached neutral, the photolu- minescence eciency was signicantly improved by using the post surface modication process. CdSe nanoparticles were prepared by using a simple route with Cd(NO3)2ㆍ4H2O and Na2SeSO3 in aqueous solution. Post surface modication of the CdSe nanoparticles by using thiol-alcohol was also performed to enhance the optical properties and to remove hydroxide (Cd(OH)2) impu- rities. CdSe nanoparticles synthesized in aqueous solution showed a zinc-blende structure and a homogeneous size distribution with a mean particle size of about 7 nm. The capping capability of 2-mercaptoethanol became active as the pH of the CdSe colloid approached neutral, the photolu- minescence eciency was signicantly improved by using the post surface modication process.

플라즈마 전해 산화처리한 시효경화 Mg-Al 합금 피막의 기계적 및 전기화학적 특성

장시영,김예림,김양도,Chang, Si-Young,Kim, Ye-Lim,Kim, Yang-Do 한국재료학회 2007 한국재료학회지 Vol.17 No.12

Plasma electrolytic oxidation (PEO) treatment was performed on cast Mg-6 wt%Al alloy solution-treated at 693K for 16h and aged at 498K. The surface roughness, thickness, micro-hardness, wear and corrosion properties of coatings on solution-treated and aged Mg-6 wt%Al alloy were investigated. The coatings on aged Mg-6 wt%Al alloy had thinner layer and lower micro-hardness and wear resistance than the solution-treated Mg-6 wt%Al alloy. As the aging time increased, the thickness of coatings decreased while the surface roughness was almost no changed. In addition, the micro-hardness and wear property of coatings decreased with increasing the aging time unlike the uncoated Mg-6 wt%Al alloy showing the peak micro-hardness and the best wear property after aging for 16 h. However, the coatings on Mg-6 wt%Al alloy peak-aged for 16h revealed the best corrosion resistance in 3.5% NaCl solution, which was explained based on the microstructural characteristics.

PVA 함유 수용액으로부터 초음파 조사에 의한 CdSe 중공 입자의 합성

박명국,김양도,이윤복,김용진,김인배 한국세라믹학회 2007 한국세라믹학회지 Vol.44 No.2

CdSe hollow spheres with the diameter of about 30-50 nm were synthesized after ultrasonic irradiation in the presence of Cd(NO3)2, Na2SeSO3, and polyvinylalcohol (PVA). The characteristics of CdSe hollow spheres were analyzed using X-ray diffraction (XRD), transmission electron microscopy (TEM), UV-vis measurement and PL spectrometer. The characteristics of solvent as water and water- 1-propanol mixture in the system played important roles on the controlled synthesis of hollow sphere. Based on the observation of morphological difference of CdSe, the possible mechanism of CdSe hollow sphere formation will be discussed.

Thermal Properties of Epoxy Composites with Silicon Carbide and/or Graphite

김정수,김양도,Dae-Geun Nam,Jong Seong Bae,염정현,오원태 한국물리학회 2016 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.68 No.4

Epoxy composites were fabricated with a filler of silicon carbide (SiC) and/or graphite to improve the thermal conductivity and thereby enhance the transfer of the heat from the light-emitting diode (LED) to the heat sink. The two fillers (SiC and graphite) were each added either separately, within a content range of 10 − 50 wt.%, or together to give a combined total content of 40 − 60 wt.%. The effect of the filler addition on the thermal and the mechanical properties of the epoxy composites was examined. The filler-induced change on the structural properties was investigated by using a morphological analysis of the epoxy composites, and the thermal conductivity was analyzed by measuring the thermal diffusivity, heat specific, and density. To confirm the adhesive property with aluminum, which is mostly used as the heat sink material were tested, the mechanical properties by using a bonding test with a modified tensile test. The thermal and the mechanical properties were improved with increasing filler content in the epoxy composites. In the case of combined filler addition, graphite was more effective than SiC in increasing the thermal properties. However, excessive filler addition reduced the epoxy’s natural adhesive property and hence degraded the mechanical properties.

Preparation of Iron Aluminate (FeAl2O4) Nanoparticles from FeAl2O4 Hollow Particles Fabricated by using a Spray Pyrolysis Process

윤재철,김양도,박대희,윤정열 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.66 No.10

Iron aluminate (FeAl2O4) hollow particles with a spinel structure were synthesized by using a spray pyrolysis process. FeAl2O4 hollow particles were formed at a reaction temperature of 900 C at a flow rate of 40 L/min as a result of the rapid solvent evaporation and decomposition gases from the droplets in the spray solution prepared from metal salts and organic reagents. FeAl2O4 hollow particles were fabricated at a reaction temperature of 900 C with a flow rate of 40 L/min. The FeAl2O4 hollow particles were heat treated for 3 hours at 600 C in a 5% H2/Ar atmosphere to form the crystal particles. Subsequently, FeAl2O4 nanoparticles were fabricated from the FeAl2O4 hollow particles by using the wet milling process. After milling for 60 minutes, transmission electron microscopy revealed the FeAl2O4 particles to have a mean size of approximately 50 nm. The FeAl2O4 nanoparticles were fabricated successfully by using a two-step process, spray pyrolysis and wet milling.