주변 공기 조성이 PE/PVC 열분해 속도에 미치는 영향에 관한 연구

홍대웅 仁荷大學校 大學院 2000 국내석사

Design and calibration of a small form factor six-component force and torque sensor using notch hinges

홍대웅 Graduate School, Korea University 2013 국내석사

This paper describes the design and calibration of a miniaturized six-component force and torque sensor using notch hinge. The new sensing structure which is different from conventional cross bar structure is proposed in order to improve the sensitivity and isotropy of the measurement. The notch hinge is a key part of achieving high sensitivity and good isotropy simultaneously in small-form-factor sensor. The sensing structure is optimized by using the Taguchi method and its condition number which represents a good measurement isotropy was 1.17. The sensitivity is about two times large than the conventional cross bar structure in same dimension. Although the optimum performance is not achieved because of various error factors in experiments, it has still relatively high performances: condition number was 1.38 and measurement sensitivities were average 1.81mV/V. The sensor was calibrated by least-squares method, and its maximum cross sensitivity is about 5%.

가토 두개골 및 누드마우스 피하에 이식한 BMP coated demineralized dentin matrix의 골형성효과에 관한 실험적 연구

홍대웅 단국대학교 대학원 2017 국내박사

�� 서론 자가골을 제외한 골이식재들은 양호한 생체적합성과 골전도성을 지니더라도 부족한 골유도능으로 인하여 골재생능력에 있어서 만족할만한 임상적 결과를 나타내지 못한다. 이에, 각종 골유도활성물질을 골이식재와 접목하여 우수한 골형성능력을 얻고자 하는 연구가 활발히 이루어지고 있다. 본 연구에서는 가토의 두개골 결손부에 실험군으로 동종의 토끼의 발치된 치아로 제조된, BMP가 매식된 탈회상아질기질(BMP coated demineralized dentin matrix, BMP coated DDM)을 이식하고, 대조군으로 동종의 토끼의 발치된 치아로 제조된 탈회상아질기질을 설정하여 양 군의 골형성능을 비교분석하였다. 또한, DDM 및 BMP coated DDM의 골유도능을 관찰하기 위하여 누드마우스의 피하에 이식하여 양 군을 비교분석하였다. �� 연구대상 및 방법 실험동물로는 일정기간 동안 동일 조건에서 사육된 생후 4주된 6마리의 자성 nude mice와 체중 3kg 내외의 자성 가토 6마리를 사용하였고, DDM 및 BMP coated DDM을 이식재로 사용하였다. 누드 마우스에서 양쪽 피하의 좌측에는 DDM을, 우측에는 BMP coated DDM을 이식하였고, 가토에서는 노출된 두개골의 양측에 bur로 외경 8mm의 원형 결손부를 형성하고, 좌측에는 DDM을, 우측에는 BMP coated DDM을 이식하였다. 누드 마우스와 가토 모두에서 각각 2마리씩, 실험 1주, 2주 및 4주 후에 희생시키고, 희생 즉시 실험군 및 대조군의 이식재를 포함하여 인접한 정상 골조직 및 연조직을 채취하고 표본을 제작하였다. 누드 마우스의 채취된 조직은 조직병리학적 관찰 및 골형성세포의 수를 계측하였으며, 가토에서 채취된 조직은 micro-computerized tomography 촬영을 시행하였고, 형태계측학적 분석을 통하여 신생골의 부피율을 측정하였다. 이후 H-E 염색 및 M-T 염색을 시행하여 조직병리학적으로 관찰하였다. 또한 획득한 영상의 일정한 범위에서 신생골의 비율을 측정 및 분석하였다. �� 결과 1. 조직병리학적 관찰 결과, 누드 마우스 피하에서 실험군과 대조군 모두 특별한 염증 반응 없이 신생골의 형성과 골유도능을 보여주었다. 2. 조직계측학적 관찰 결과, 누드 마우스에서 BMP coated DDM을 이식한 실험군에서 DDM을 이식한 대조군에 비하여 골형성세포수가 많이 관찰되었으며, 특히 4주차에서 월등히 증가된 양상을 나타내었다. 3. 가토 두개골의 Micro-CT 정량적 분석 및 조직형태학적 관찰 결과, 대조군과 실험군 모두에서 1주, 2주 및 4주의 시간이 경과함에 따라 신생골의 부피율은 증가하였고, BMP coated DDM을 이식한 실험군에서 4주차에 신생골의 형성량이 급격히 증가하였다. �� 결론 위 실험 결과를 토대로 본 연구에서는 BMP coated DDM의 골형성능은 기존의 DDM을 대체가능하며, rhBMP-2의 장기적인 유지가 가능한 scaffold로 적절한 역할을 하리라 사료된다. Introduction: Bone graft materials, excluding autograft, may have acceptable biocompatibility and osteoconductibility, but due to the lack of osteoinductivity clinical outcomes are not satisfying in terms of osteogenesis. Consequently, studies of combining various osteoinductive materials with bone graft materials to achieve satisfying degree of osteogenesis are actively conducted. In this study, osteogeneses were compared and analyzed in two groups of rabbit skulls with defects. As an experimental group, BMP coated demineralized dentin matrix (BMP coated DDM) produced from the extracted teeth of allogeneic origin were transplanted to the skull defects, and as a control group, demineralized dentin matrix (DDM) produced from the same origin were transplanted. Also, to observe the osteoinductivity of DDM and BMP coated DDM, each kind was transplanted to each of two groups of nude mice respectively, then compared and analyzed. Materials and Methods: 6 Female nude mice aged 4 weeks and 6 female rabbits weighing approximately 3kg that were bred under the same environment for certain periods were chosen as subjects, and DDM and BMP coated DDM were applied as graft materials. For nude mice, DDM was transplanted on the left subcutaneous tissue, and BMP coated DDM on the right side symmetrically. For rabbits, round defects with external diameter of 8mm were formed with burs at the both sides of the exposed skull, then DDM was transplanted at the left sides, and BMP coated DDM at the right sides. Nude mice and rabbits were sacrificed at the 1st, 2nd and 4th experimental week, two at each. Immediately after sacrifice, graft materials of both experimental and control groups were obtained including adjacent normal bone and soft tissues, and specimens were fabricated. Tissues from nude mice went under histopathological observation and osteogenic cells were counted. Tissues from rabbits went under micro-computerized tomography imaging, and volume ratio of newly formed bone were calculated via histomorphometric analysis. Then, the specimens were histopathologically observed after H-E staining and M-T staining. Also, the ratio of new bone was calculated and analyzed from a certain extent of the acquired images. Results: 1. After histopathological observation, new bone formation and osteoinduction without any particular inflammatory reaction were shown at subcutaneous tissues in both experimental and control groups of nude mice. 2. After histomorphometrical observation, more osteogenic cells were observed in experimental group with BMP coated DDM than in control group with only DDM, and the cell count vastly increased at the 4thweek. 3. After quantitative analysis of Micro-CT and histomorphological observation of rabbit skulls, the volume ratio of new bone increased as weeks passed by in both experimental and control groups, and the amount of new bone formation drastically increased at the 4thweek in experimental group with BMP coated DDM. Conclusion: Based on the results of this study, osteogenic capability of BMP coated DDM makes it a possible replacement of DDM, and is expected to take a proper role as a scaffold for long-term preservation of rhBMP-2.

나노 감지물질과 광촉매를 이용한 저전력형 마이크로 가스센서의 감응특성 연구

홍대웅 연세대학교 대학원 2008 국내석사

TiO2는 3.2 eV의 에너지 밴드갭을 가지며 이 밴드갭에 해당하는 근자외선(380 nm) 광을 조사하면 TiO2 표면에 hydroxy radical과 superoxide가 생기게 된다. 이런 광촉매 효과에 의해 환경 개선형 소재로의 응용이 대두되었고 90년대 후반 주목을 받기 시작한 나노 기술은 센서분야에서 감도의 향상뿐 아니라 소자의 소형화, 낮은 생산 단가, 저전력 소비형 센서 제작 등의 장점을 제공하였다.본 논문에서는 sol-gel 공정을 이용하여 수소에 흡착력을 갖는 30 nm 이하의 입자사이즈를 갖는 SnO2, F doped SnO2(FTO) 나노 감지물질과 수열합성법에 의해 50 nm 이하의 입자사이즈를 갖는 광촉매(photo-catalyst)인 Pd/titanate 및 Pt/titanate nanotubes를 합성하였고 이 물질을 비표면적이 큰 감지물질로 사용하여 센서의 출력특성을 30% 이상 향상시켰다. 그리고 TiO2 광촉매와 UV-LED를 이용하여 수소센서의 동작온도를 100℃ 이상 낮추었고 피독된 센서를 회복시킬 수 있었다. 또한 thermal evaporation을 이용하여 백금 박막히터를 증착하여 170 mW 이하의 저전력형 접촉연소식 수소센서를 제작하였다. 이 센서는 제조가 간단하고 공정이 복잡하지 않으며, 저농도에서 부터 수소의 LEL(Lower Explosive Limit)인 4% 농도까지 수소기체를 신뢰성 있게 감지하고(선형성), 5 sec 이하의 빠른 반응속도와 타 가연성 가스에 2.5% 이내의 좋은 선택도를 보였다. 본 연구의 결과를 이용하면 지구온난화의 대안으로 수소를 이용하는 다양한 시스템에 적용하여 수소의 위험성 방지 및 안전이용 증대 등을 기대할 수 있다. First type Pt heater was fabricated by screen printing method and second type Pt thin film as a micro heater was deposited by thermal evaporation on the alumina substrate. The thickness of Pt thin film was measured around 160 nm. Comparison between sensor with screen printing Pt heater and sensor with Pt thin film shows significant decrease in the power consumption due to the heater structure having 50㎛ line width and small substrate size (1×0.5 mm).F-doped SnO2(FTO) nanocrystalline materials were synthesized by using a sol-gel method. XRD, FE-SEM, FE-TEM, TG/DTA and EDAX were used to characterize the composion of sensing materials. The calculated average crystal size(D) of nanocrystals was found to be around 30 nm. The sensors based on Pd/Pt catalyst supported FTO nanocrystalline system exhibited better performance than Pd/Pt catalyst on γ-Al2O3.A thick film catalytic gas sensor operable at a temperature of 125oC with the presence of UV-LED(Utra Violet-Light Emitting Diode) has been developed to measure hydrogen concentration of 0.5% to 5%. The reduction of operating temperature from 253oC to 125oC in the presence of UV radiation is attributed to the enhanced activity of the chemisorbed oxygen ions, which facilitate a higher rate of reaction between O2 and H2.Pd/titanate and Pt/titanate nanotube catalysts were synthesized by a hydrothermal synthesis method. The out diameter of nanotubes in TEM images was approximately 50 nm. The sensor with titanate nanotubes showed higher response than the one without titanate nanotubes. This seems to be due to the evenly dispersed Pd and Pt catalysts on the titanate nanotubes at a nanoscale level, and the better adsorption of hydrogen on the titanate nanotube surface which facilitates the oxidation of hydrogen by the Pd and Pt catalysts.Recovery properties after H2S catalytic poisoning of catalytic combustion type gas sensor with photo-catalysts and UV radiation have been examined. All the sensors were deactivated after 500 ppm H2S exposure for 20 h. The sensors with Pd/titanate or Pt/titanate nanotubes showed regenerated voltage response under UV radiation for 50 h. However the sensor with TiO2 particles showed negligible regenerated voltage response. Regenerated voltage response with Pd/titanate or Pt/titanate nanotubes may stem from higher surface area of Pd/titanate or Pt/titanate nanotubes.SnO2 nanocrystalline materials were synthesized by using a sol-gel method. The sensor with SnO2 and Pt thin film showed high reliability with prominent selectivity against various gases(CO, C3H8, CH4) at low operating temperature (156oC). The sensor with nanocrystalline SnO2 showed higher sensitivity than that without nanocrystalline SnO2. This can be explained by the better adsorption and oxidation of hydrogen, cause by the larger surface area of sensing material. The presented flat-type catalytic combustible hydrogen sensor can be a good candidate for detection of hydrogen leaks.

Open-Path FTIR 해석 소프트웨어 COL1SB의 개발과 적용에 관한 연구

홍대웅 인하대학교 일반 대학원 2004 국내박사

이종탈회상아질기질의 BMP 비계체로서의 역할에 대한 실험적 연구

홍대웅 단국대학교 2014 국내석사

▶ 서론 기존의 골이식재의 단점을 극복하기 위하여, 골 형성 촉진을 위한 신호전달물질을 이용한 기초 연구와 임상적 연구가 활발히 진행되고 있으며, 그 중 하나가 골형성단백질(Bone morphogenetic protein, BMP)를 이용한 연구로서 1965년 Urist가 탈회된 골기질에서 골유도 능력이 있는 단백질을 추출하여, 이를 BMP라 명명한 이래, 현재까지 이를 이용하기 위한 노력들이 이어지고 있다. BMP는 수용성이며 반감기가 짧으므로, 임상적으로 단독 사용시 이식 부위에 BMP의 유지와 계속적인 분비가 매우 어려워, BMP를 유지하고 분비를 위해서는 적절한 매개체가 필요하다. 이에 착안한 본 연구는, 가토의 두개골 결손부에 Bio-oss를 대조군으로 하고 실험군으로 소의 발거 치아로부터의 탈회상아질기질(Demineralized Dentin Matrix, DDM)과 BMP를 혼합하여, 양 군의 골형성능력을 조직형태계측학적으로 비교하여 탈회상아질기질의 BMP의 비계체로서의 능력에 대한 역할을 규명하고자 하였다.  ▶ 연구대상 및 방법 실험동물로는 일정기간 동안 동일 조건에서 사육된 체중 3kg 내외의 자성 가토 12마리를 사용하였고, DDM과 Bio-ossⓇ(Geistlich-Pharma AG, Wolhusen, Switzerland)를 이식재로 사용하였다. 노출된 두개골의 양측에 bur로 외경 8mm의 원형 결손부를 형성하고, 좌측에는 DDM을, 우측에는 Bio-oss를 이식한 후 vicryl로 봉합하였다. 실험 후 2주, 8주에 실험동물을 희생하였고, 희생 즉시 이식재와 인접 조직을 포함하여 채취하였으며 채취된 조직은 표본을 제작하여 H-E, MT 염색 후 광학현미경을 이용하여 병리조직학적으로 관찰하였다. 또한 획득한 영상의 일정한 범위에서 신생골의 비율을 측정 및 분석하였다. ▶ 결과 1. 조직학적 관찰 결과, Bio-oss를 이식한 군과 BMP를 혼합한 이종탈회상아질기질을 이식한 군 모두에서 2주 및 8주차에 골형성세포들이 관찰되고 형태학적으로 비슷하였으나, BMP를 혼합한 이종탈회상아질기질 이식군에서 골형성세포의 작용이 더욱 활발하였고 신생 혈관, 연골 및 골수의 형성이 왕성하였다. 2. 2주째 소견에서 조직형태계측학적 결과, BMP를 혼합한 이종탈회상아질기질 이식군(35.03%)이 Bio-oss 이식군(25.15%)에 비하여 신생골 형성 면적비율이 높았으나, 통계적 유의성은 없었다. 3. 8주째 소견에서 조직형태계측학적 결과, BMP를 혼합한 이종탈회상아질기질 이식군(95.12%)이 Bio-oss 이식군(92.46%)에 비하여 신생골 형성 면적비율이 높았으나, 통계적 유의성은 없었다. ▶ 결론 본 연구에서는 DDM에 BMP를 혼합한 이식재의 골형성 능력을 입증하고 DDM의 비계체로서의 가능성에 대하여 실험적 연구를 진행하여 이종탈회상아질기질이 BMP의 비계체로서의 가능성이 있음을 확인할 수 있었고, 구강악안면영역에 있어서 우수한 골이식재 개발에 기여할 수 있음을 보여주었다.

경기도 문화콘텐츠분야 창업보육센터 지원서비스가 입주기업 성과에 미치는 영향에 관한 연구 : 창업아이템의 사업타당성을 중심으로

홍대웅 중앙대학교 산업·창업경영대학원 2017 국내석사

As the recent cultural contents area start-ups are creating remarkable outcomes such as investment attraction together with the reinforced institutional supports from the government, this study aimed to reverify the significance of researches related to correlation analysis between service of Business Incubating Center of Small & Medium Business Administration operated with no separation of business type, and corporate performance, in the aspect of Business Incubating Center in cultural contents area, and also to suggest the importance of establishing the business incubating system in the systematic and rational cultural contents area through the differentiated business incubating service by verifying the significant effects of the business validity of items on corporate performance, and then discovering services suitable for business incubating in cultural contents area, targeting Gyeonggi-do cultural contents area Business Incubating Center recently showing the biggest growth. Especially, contrary to the existing researches, in order to verify the characteristics of Gyeonggi-do Cultural Contents Business Incubating Center, the personal support service and marketing support service were included. It also aimed to understand the effects of the business validity of start-up items on corporate performance. Summarizing the results of this study, contrary to the results of the existing researches saying that spatial & additional support service, management support service, technical support service, personal support service, and marketing support service had significant effects on corporate performance, among the support service of Gyeonggi-do cultural contents area Business Incubating Center, the spatial & additional support service, personal support service, and marketing support service had significantly positive(+) effects on corporate performance while the management support service and technical support service had no significant effects on it. Comparing with the results of the researches on the support service of Business Incubating Center(BI) of Small & Medium Business Administration, the effects of the management support service and technical support service of Gyeonggi-do cultural contents area Business Incubating Center on corporate financial/non-financial performance were not huge. Also, in the results of analyzing the business validity of star-up items, the spatial & additional support service, management support service, and technical support service did not have significant effects on the business validity of start-up items while the personal support service and marketing support service had significantly positive(+) effects on it. In case when selecting companies, Gyeonggi-do Business Incubating Center emphasized the business validity of start-up items. However, the support service provided after the selection did not have huge effects on the business validity of start-up items. Lastly, in the results of analyzing the effects of the business validity of start-up items in Gyeonggi-do cultural contents area on corporate performance, among the success factors of business start-up, the business validity of start-up items was an important element having effects on corporate performance(financial/non-financial) in the cultural contents area. Keywords: Business Incubating Center, Support Service, Spatial & Additional Support Service, Management Support Service, Technical Support Service, Personal Support Service, Marketing Support Service, Business Validity of Business Start-Up Item, Corporate Performance 본 연구는 온라인 및 대면 설문조사를 통해 경기도 문화콘텐츠분야 창업보육센터 지원서비스가 입주기업 성과에 미치는 영향을 창업아이템의 사업타당성을 중심으로 분석하였다. 본 연구는 최근 문화콘텐츠 분야 스타트업은 투자유치 등에서 눈에 띄는 성과를 창출하고 있고, 정부의 정책적 지원도 강화되고 있는 상황에서 기존의 업종구분 없이 운영되는 중기청 창업보육센터의 서비스와 입주기업의 성과와의 상관관계 분석과 관련된 연구들을 문화콘텐츠 분야의 창업보육센터의 관점에서도 유의미한지 재 검증해보고, 또한 문화콘텐츠 기업의 특성상 아이템의 사업타당성이 입주기업의 성과에 유의미한 영향을 미치는지에 대해 검증하여, 문화콘텐츠 분야의 창업보육에 적합한 서비스를 발굴하고 차별화된 창업보육 서비스를 통해, 성과가 도출될 수 있도록 체계적이고 합리적인 문화콘텐츠 분야의 창업보육시스템 구축의 중요성을 제기해보고자 최근 성장세가 가장 큰 경기도 문화콘텐츠분야 창업보육센터를 대상으로 연구하였다. 특히 기존 연구와 달리 경기도 문화콘텐츠 창업보육센터 특성을 확인하고자, 인적지원 서비스와, 마케팅 지원서비스를 포함하였고, 창업아이템의 사업타당성이 입주기업 성과에 미치는 영향에 대해 확인해 보고자 하였다. 본 연구의 결과를 요약하면, 기존 연구에서 공간 및 부대지원 서비스, 경영지원서비스, 기술지원 서비스, 인적지원 서비스, 마케팅 지원서비스는 입주기업의 성과에 유의미한 영향을 미친다는 연구 결과와 달리, 경기도 문화콘텐츠 분야 창업보육센터의 지원서비스는 공간 및 부대지원, 인적지원, 마케팅 지원서비스는 입주기업의 성과에 유의미한 정(+)의 영향을 미치고, 경영지원 및 기술지원은 유의미한 영향을 미치지 않는 것으로 나타난 것이 특징이라고 할 수 있다. 이는 기존 중소기업청 창업보육센터(BI) 지원서비스에 대한 연구결과에 비교해 볼때 경기도 문화콘텐츠분야 창업보육센터의 지원서비스는 경영지원 서비스와, 기술지원 서비스가 입주기업의 재무적‧비재무적 성과에 미치는 영향이 크지 않음을 확인 할 수 있었다. 또한, 창업보육센터의 서비스가 창업아이템의 사업타당성에 미치는 영향을 분석한 결과, 공간 및 부대지원서비스, 경영지원서비스, 기술지원 서비스는 창업아이템의 사업타당성에는 유의한 영향을 미치지 않는 것으로 나타났으며, 인적지원 서비스 및 마케팅 지원 서비스는 유의미한 정(+)의 영향을 미치는 것을 확인 할 수 있었다. 이는 경기도 창업보육센터는 입주기업 선발 시에는 창업아이템의 사업타당성을 중시하는 반면, 입주 후 제공되는 지원 서비스는 창업아이템의 사업타당성에는 밀접한 영향을 미치지 못하고 있다는 것을 확인 할 수 있었다. 마지막으로, 경기도 문화콘텐츠 분야 창업아이템의 사업타당성이 입주기업의 성과에 미치는 영향을 미치는 것을 분석한 결과 창업의 성공요소 중 문화콘텐츠분야의 창업에서는 창업아이템의 사업타당성이 입주기업의 성과(재무적,비재무적) 성과에 모두 영향을 미치는 중요한 요소임을 확인 할 수 있었다. 핵심어: 창업보육센터, 지원서비스, 공간 및 부대지원 서비스, 경영지원서비스, 기술지원서비스, 인적지원서비스, 마케팅지원서비스, 창업아이템의 사업타당성, 입주기업의 성과

(A) study on regulation of stomatal movements by the ROP2-RIC7 pathway

홍대웅 Pohang University of Science and Technology 2015 국내박사

Stomata regulate gas exchange between plants and atmosphere, optimize photosynthetic CO2 fixation, and minimize transpirational water loss. Stomata move rapidly to adjust plants to the ever-changing environment. Stomatal movement is affected by environmental and plants internal conditions, such as light and circadian clock signals, atmospheric CO2 levels, humidity, temperature, plant hormone abscisic acid (ABA), and pathogens. Stomatal opening and closing movements are manifested by guard cell volume changes, which involve membrane trafficking via endocytosis and exocytosis, ion accumulation, net water flux, and reorganization of actin cytoskeleton. Important signaling molecules that regulate these cellular responses include cytosolic Ca2+, protein kinases and phosphatases, reactive oxygen species, heterotrimeric G proteins, and ROP small G proteins. ROP GTPases (Rho-related GTPases from plants) belong to a distinct subfamily of the RHO GTPases and function as molecular switches during growth and development. Arabidopsis has 11 ROP GTPases important for pollen tube growth, seedling development, leaf epidermal pavement cell morphogenesis and lateral root initiation. There is emerging evidence that ROP GTPases negatively regulate the stomatal movements. ROP2 has been reported as negative regulator of stomatal movements because it inhibited the light-induced stomatal opening and ABA-induced stomatal closure. ROP GTPases are expected to have a number of interacting partners to mediate diverse plant responses. ROP-interactive CRIB motif-containing proteins (RICs) act as direct targets of ROP GTPases. RIC7 is a downstream target of ROP2 and functions in ROP2-mediated light-induced stomatal opening because RIC7 interacts with active-ROP2 in vitro and RIC7 overexpression via bombardment inhibits light-induced stomatal opening in V. faba, similarly as active-ROP2 overexpression does. The aim of this study is to identify RIC7 function in Arabidopsis and how ROP2-RIC7 negatively regulates stomatal movements. To understand the mechanism by which RIC7 regulates light-induced stomatal opening, I analyzed the stomatal responses of ric7 mutant Arabidopsis plants. Light-induced stomatal opening was promoted by ric7 knockout, whereas it was inhibited by RIC7 overexpression, indicating that RIC7 negatively regulates stomatal opening in Arabidopsis. Next, to decipher the mechanism of RIC7 function in stomatal movement, I searched for binding partners of RIC7 using yeast two-hybrid screen. I identified Exo70B1, a component of the exocyst complex that mediates vesicle tethering during exocytosis, as an interaction partner of RIC7, and confirmed this finding using a pull-down assay and bimolecular fluorescence complementation analysis. In V. faba guard cells, Exo70B1 was present mainly in cytoplasm under darkness, but not to the Golgi, TGN, or early endosome, while RIC7 was mostly present in the nucleus. By contrast, upon irradiation with white light, Exo70B1 and RIC7 were translocated and co-localized to the plasma membrane region. Moreover, localization of Exo70B1 in guard cells was largely overlapped with that of Exo84B, another subunit of the exocyst complex. Exo70B1 is highly expressed in Arabidopsis guard cells and Exo70B1 knockout Arabidopsis was delayed in light-induced stomatal opening and the Exo70B1 complementation lines recovered the retarded stomatal opening phenotype. These results indicate Exo70B1 is a positive regulator of light-induced stomatal opening. Furthermore, Light-induced stomatal opening was slower in RIC7/Exo70B1 double-knockout Arabidopsis than in the wild type, indicating Exo70B1 is a downstream target of RIC7. Together, I conclude that active ROP2 and RIC7 negatively regulate light-induced stomatal opening by inhibiting Exo70B1. This study revealed ROP2 and RIC7 suppress excess stomatal opening by inhibiting Exo70B1, which positively regulates stomatal opening. When recruited by active ROP2 to the plasma membrane region, RIC7 inhibits Exo70B1 function. Exo70B1 is the first member of the Exo70 family shown to be involved in stomatal movement. Moreover, Exo70B1 is a novel target of the small G protein ROP2-RIC7 signaling pathway, which modulates the kinetics of stomatal movement.

(The) quantitative performance evaluation system for triboelectric energy harvesters

홍대웅 Garduate School, Korea University 2019 국내박사

This dissertation presents a study on quantitative performance evaluation system for triboelectric energy harvester. The triboelectric energy harvester (TEH) has become one of the strongest candidates for sustainable power sources. The output of TEH depends on factors such as contact area, contact parallelism, contact force and contact speed. In order to accurately and quantitatively evaluate the performance of TEH, it is necessary to apply consistent experimental conditions and measurement processes. However, this quantitative evaluation study is insufficient compared to the study on the new TEH structure. In this study, we propose an evaluation system that can adjust contact area and contact parallelism and measure contact force, contact speed, current and voltage in real time. In the proposed evaluation system, the effects of parallel error, contact area, contact force and contact speed on the performance of contact mode TEH were quantitatively analyzed. This evaluation system was used for quantitative analysis of contact mode TEH of various new structures and for comparison between different devices. We also proposed a system capable of quantitatively analyzing rotary type TEH. The conventional experimental system for rotary type TEH conducted a function of applying rotational motion and did not control the factors affecting rotary type TEH. To overcome these limitations, this system enabled the horizontal alignment of the rotor and the stator, the pressure applied to the contact surface, and the rotation speed could be controlled. When the rotary type TEH was operated, the applied rotational torque could be measured in real time, so that various types of rotational type TEH could be quantitatively compared. We presented the effectiveness of the proposed system by performing quantitative performance evaluation of actual TEH. First, two surface treatment techniques to improve the performance of the contact mode TEH were presented, and the results of the analysis of how much the TEH performance improves quantitatively were presented using this evaluation system. In addition, the development of thin film type TEH based on printed electronics and the quantitative performance evaluation results were presented. A new structure called the dual-side rotary freestanding TEH that could improve the performance by 200% or more than the conventional rotary type TEH had been presented. The experimental results how the performance of this device was actually improved compared to the conventional rotary type TEH were presented.