• Title/Summary/Keyword: Turn-on and Turn-off

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PWM-PFC Step-Up Converter For Novel Loss-Less Snubber (새로운 무손실 스너버에 의한 PWM-PFC 스텝-업 컨버터)

  • Kwak Dong-Kurl;Lee Bong-Seob;Jung Do-Young
    • Journal of the Institute of Electronics Engineers of Korea SC
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    • v.43 no.1 s.307
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    • pp.45-52
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    • 2006
  • In this paper, authors propose a step-up converter of pulse width modulation (PWM) and power factor correction (PFC) by using a novel loss-less snubber. The proposed converter for a discontinuous conduction mode (DCM) eliminates the complicated circuit control requirement and reduces the size of components. The input current waveform in the proposed converter is got to be a sinusoidal form of discontinuous pulse in proportion to magnitude of ac input voltage under the constant duty cycle switching. Thereupon, the input power factor is nearly unity and the control method is simple. In the general DCM converters, the switching devices are fumed-on with the zero current switching (ZCS), and the switching devices must be switched-off at a maximum reactor current. To achieve a soft switching (ZCS and ZVS) of the switching turn-off, the proposed converter is constructed by using a new loss-less snubber which is operated with a partial resonant circuit. The result is that the switching loss is very low and the efficiency of converter is high. Some simulative results on computer and experimental results are included to confirm the validity of the analytical results.

Changes in Fat in Gouda Cheese by the Psychrotrophic Bacterium Acinetobacter Genomospecies 10 (내냉성미생물인 Acinetobacter genomospecies 10에 의한 gouda cheese의 지방의 변화)

  • Shin, Yong Kook;Oh, Nam Su;Lee, Hyun Ah;Nam, Myoung Soo
    • Journal of Life Science
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    • v.25 no.2
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    • pp.174-179
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    • 2015
  • The presence of psychrotrophic bacteria downgrades the quality of dairy products. This study evaluated the effect of lipolytic psychrotrophic bacteria on the chemical properties of Gouda cheese made from raw milk experimentally inoculated with a psychrotrophic bacterium (Acinetobacter genomospecies 10). Raw milk experimentally inoculated with Acinetobacter genomospecies 10 and refrigerated at $4^{\circ}C$ for 3 or 6 days produced a 6-week ripened Gouda cheese with a significant decrease in total solids (p<0.05) or an increased fat content (p<0.05), respectively. Raw milk inoculated with Acinetobacter genomospecies 10 and refrigerated for 3 days had higher (p<0.05) SCFFA (1.35 times), MCFFA (1.42 times), and LCFFA (1.44 times) than the control 6-week ripened Gouda cheese. The cheese manufactured from the inoculated and refrigerated raw milk had higher (p<0.05) total free fatty acids (1.68 times) compared with the control. Raw milk inoculated with Acinetobacter genomospecies 10 and refrigerated for 6 days had increased SCFFA (1.45 times), MCFFA (1.28 times), and LCFFA (1.38 times) compared with the control 6-weeks ripened Gouda cheese. The 6-week ripened Gouda cheese manufactured from this inoculated milk had higher (p<0.05) total free fatty acids (1.34 times) compared with the control. The results indicated that the production of excessive free fatty acids in dairy products by psychrotrophic bacteria can be critical in predisposing dairy products to off-flavors and in turn degrading their quality.

A Study on the Stabilization of the Papain Enzyme in the Moderately Concentrated Anionic Surfactant System (음이온 계면활성제에서 파파인 효소의 안정도에 관한 연구)

  • Kim, Ji-Yeong;Kim, Jin-Woo;Kim, Yong-Jin;Lee, Jae-Wook;Lee, Hae-Kwang;Kang, Hak-Hee
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.33 no.2
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    • pp.93-97
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    • 2007
  • Even in the moderately concentrated anionic surfactant system, some special encapsulation method can shield the papain enzyme from proteolytic attacks. The stabilization of enzyme has been a major issue for successful therapies. In this study, we first stabilized an enzyme, papain in the microcapsules by using polyols, polyethyleneglycol (PEG), poly-propyleneglycol (PPG), and PEG-PPG-PEG block copolymer. In the analysis of EDS and CLSM, it was demonstrated that polyols are effectively located in the interface of papain and polymer. Polyols located in the interface had an ability to buffer the external triggers by hydrophobic partitioning, preventing consequently the catalytic activity of papain in the micro-capsules. Second. we introduced multi-layer capsulation methods containing ion complex. Such a moderately concentrated anionic surfactant system as wash-off cleansers, surfactants and waters can cause instability of entrapped enzymes. Surfactants and water in our final products swell the surface of enzyme capsules and penetrate into the core so easily that we can not achieve the effect of enzyme, papain. In this case, the ion complex multi-layer capsule composed of sodium lauroyl sarcosinate and polyquaternium-6 could effectively prevent water from penetration into the core enzyme, followed by in vivo test, and evaluate the stratum corneum (SC) turn-over speed.

Effects of Relational and Mandatory Influence Strategies on Sales Representatives and Headquarter Trust (관계적과 강제적 영향전략이 본사 신뢰에 미치는 영향 : 영업사원 신뢰의 매개역할)

  • Lee, Chang-Ju;Lee, Phil-Soo;Lee, Yong-Ki
    • Journal of Distribution Science
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    • v.14 no.6
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    • pp.53-63
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    • 2016
  • Purpose - This study examines the effects of the influence strategies on sales representative and headquarter trust, and investigates how sales representative trust plays a mediating role in the relationship between influence strategies and headquarter trust. For these purposes, a structural model which consists of several constructs was developed. In this model, influence strategies that consist of relational influence strategies (information exchange, recommend, promise) and mandatory influence strategies (legal plea, request, threat) were proposed to affect the sales representative trust and in turn, increase the headquarter trust. Thus, this study proposed that sale representative trust plays a core mediating role in the relationship between relational and mandatory influence strategies and headquarter trust in B2B food materials distribution context. Research design, data, and methodology - For these purposes, the authors collected the data from 208 B2B specialized complex agents. We used the 2,200 B2B specialized complex agents which trade with CJ, Ottogi, and Daesang firms and supply food materials to restaurant, school cafeteria, supermarket and traditional market as a sample frame. Once we identified 330 B2B specialized complex agent owners, CEOs, and/or Directors who had agreed to participate in this study, we dropped off a questionnaire at each B2B specialized complex agent and explained the purpose of this study. The survey was conducted from October 1, 2015 to December 15, 2015. A total of 230 questionnaires were collected. Of these collected questionnaires, 28 questionnaires excluded since they had not been fully completed. The data were analyzed using frequency test, reliability test, measurement model analysis, and structural equation modeling with SPSS and SmartPLS 2. Results - First, information exchange, recommendation, and promise of relational influence strategies had positive effects on sales representative trust. The threat of mandatory influence strategies had a negative effect on sales representative trust, but legal plea and request did not have a significant effect on sales representative trust. Second, information exchange and recommendation of relational influence strategies had positive effects on headquarter trust, but promise did not. Also, legal plea, request, and threat of mandatory influence strategies did not have a significant effect on headquarter trust. Third, this findings show that sales representative trust plays a partial mediator between information exchange and headquarter trust, and threat and headquarter trust, and a full mediator between promise and headquarter trust, and recommendation and headquarter trust. Conclusions - The aim of this study was to examine the effects how diverse dimensions of relational and mandatory influence strategies relate to sales representative trust and headquarter trust. To do so, we integrated the influence strategies and the trust transfer theory to hypothesize that various influence strategies increase sales representative and headquarter trust. The findings of this study suggest that headquarter firms should establish and enforce proper influence strategies guidelines to make clear what proper actions sales representatives should implement in relationship with B2B specialized complex agents. Also, relational and mandatory influence strategies must be regarded as a long-term and ongoing strategy that eventually build a long-term orientation with B2B specialized complex agents and guarantee a company's sustainable growth and success.

A study on the cultural ideology of narrative in 3D C.G. Animation (3D C.G. 애니메이션에 반영된 문화적 이데올로기 - <슈렉>을 중심으로)

  • Koh, Eun-Young
    • Cartoon and Animation Studies
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    • s.6
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    • pp.7-22
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    • 2002
  • Animation constitutes the core of the media industry, which in turn lies at the center of the cultural industry. It is considered one of the industries where South Korea has the competitive edge over other countries. With the pool of customers getting wider, the genre of animation has become more and more diverse, forming a great market for it. Aware of this trend, this study focused on animation as a part of the pop culture, and on providing corresponding various viewpoints for future cultural studies. This researcher measured the practicality and persuasiveness of this study through Shreck, a three-dimensional C.G. animation which is acclaimed for its success in dismantling the old grammar of animation movies that represent the anti-Disney ideas. This researcher felt it imperative to heed the unique language of Shreck, which contains discourses on various cultural ideologies such as paradoxical structure that pits entertainment that is shown through dismantling of the canon, feminism and antifeminism against each other. This study analyzed the entertaining element of the animation genre by means of the Semiotics of Keith Moxey, thereby attempting to establish a legitimate social status of the genre, whose artfulness has been depreciated in the art society. In chapter II, this researcher examines the chronological development of three-dimensional C.G. animation that has shown a rapid advancement. Chapter III defines the cultural ideology of Shreck by exploring basic theories and texts employed in analysis of art works. This study started with the assumption that defines, from the viewpoint of symbology, the animation text as an aggregate of discourses on entertainment, and competitive and paradoxical ideologies. Then, this researcher analyzed the text and the generation process of meanings in Shreck. Consequently, this study has come to the following conclusions: First, Shreck induces changes of concepts about the canon by means of distorting and reversing the existing animation movies, which seems to reflect in the contemporary tendency of seeking new interpretations of entertainment. Second, Shreck shows up the cognitive changes of our age as to feminism by competing feminism against antifeminism. Although Shreck serves as a venue of competition between the two opposing ideas, it stops short of brushing off women as outsiders in society. Rather, it represents the resistance to the male chauvinism existing in the structures of animation and culture. As shown in the text analysis, Shreck presents an advent of a new ideology critical of the previous animation films. In addition, it reflects in the struggle between the pro-feminism on the part of the viewers and the anti-feminism that lies in the social and culture structure. This study, however, is limited in its scope and selection of subject. First, although this researcher has stressed the importance of understanding the animation as part of the pop culture and conducting researches within the historic paradigm, this study fails to provide an in-depth insight in the impacts that the changes in the C.G. industry and the systematic conditions may have on the three-dimensional C.G. animation genre. Furthermore, this study runs the risk of being understood as pro-American due to its selection of Shreck as its research subject.

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Why Genuine Luxury Brands Are Consumed? Counterfeits? Examining Consumer Identification

  • Suh, Hyunsuk
    • Asia Marketing Journal
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    • v.14 no.3
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    • pp.69-102
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    • 2012
  • Owing to increased number of luxury brand users, both genuine and counterfeit luxury product consumption continues to increase every year. Luxury brand is defined as use or display of a particular branded products which brings the ownership prestige apart from its functional utility(Grossmand and Shapiro 1988). Some luxury brands have imitations sold in marketplace due to their popularity. These imitations or counterfeits have been jumping on the bandwagon of the upturn in sales of their originals. The purpose of our study is to understand consumer's underlying motives to consume luxury brands, genuine and or counterfeits. To do this, we propose functional theories of attitudes, decision-making styles, and life attitudes to form the determining causes for different consumption choices of luxury brands: genuine brands, counterfeit brands, both genuine and counterfeit brands, and no consumption on luxury brands types. In proposed causal pathways, we examine moderated effects of socio-psychological factors to further investigate if consumer profiles would exert influences in causal relationships. From the existing theories of functional attitudes: value-expressive and social-adjustive attitudes, we developed and introduced a new measure of rationality-consumptive attitude. From the existing eight decision-making characteristics of consumer styles inventory(CSI), three measures of high-quality, hedonic-shopping, and price-shopping styles were primarily applied in the study along with newly introduced measure of 'high-price' being added, which makes four total. Seven life attitude measures of life purpose, life control, will to meaning, goal seeking, future mean to fulfill, life satisfaction, and religiosity were applied. Finally, such socio-psychological measures as age, gender, marital status, income, and age-gap between couples were assumed to function as moderators. With 430 valid study samples, ages from 20s to 50s, with more females(316) than males(114), with average personal possessions of 5 genuine and 9 counterfeit luxury brands, we conducted questionnaire survey. Results indicated that social-adjustive function is totally disappeared in the relationship due to current social trend of widespread consumptions on both genuine and counterfeit brands which in turn, make consumers feel less special on wearing or carrying them unlike in the past. Self-expressive function and rationality-consumptive functions act as strong catalysts for genuine brand consumption and counterfeit brand consumption, respectively. On consumers' decision-making styles, high-price sublation is the most powerful indicator anticipating counterfeit consumption, even more powerful than personal incomes. In life attitude, the overall model fit was not validated, and only life control and life satisfaction are proven to be significant on both genuine and counterfeit product consumptions. Employment of socio-psychological factors in the model improved understanding of users further. Young consumers tend to go for genuine products over counterfeits. Consumers in different income groups; low, medium and high, all significantly consume genuine products for reasons of different decision-making styles. The results indicated that consumers whose personal disposition is predisposed to consume products in the form of reflection of his or her personality, go only for genuine brands for quality reason, while consumers who rationally consume products for its function or usability, go only for counterfeits for high-price sublation reason. Meanwhile, both product users support for high-price orientation who are not well off.

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A Study on Nurse - Patient Interacting Behaviour Patterns (간호사-환자 상호작용 양상에 관한 연구)

  • 이성심;지성애
    • Journal of Korean Academy of Nursing
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    • v.20 no.1
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    • pp.61-78
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    • 1990
  • The purpose of the present study is to confirm the interacting behavior between nurses and patients and other things concerned herewith. Subjects of investigation were : 42 nurses selected out of the average nurses who serve in hospital as nurses assigned to medical and surgical wards : and 42 male and female adult patients selected out of the average patients who were under the care of the nurse individuals and can make themselves understood verbally. A nurse and her patient were paired off for questioning. Materials for statistics were gathered by means of observaing interactions- - verbal and nonverbal - -of the chosen subjects for four hours every day from 7 : 30 a.m. through 7 : 30 p.m. between on July 15, 1988 and on Aug. 16, 1988. Classified by patterns, the materials observed and gathered were preliminarily analyzed by this researcher, and then reexamined in a full-fledged way by one professor, three nurses and three non - nurses. The researcher depended chiefly on Frequency, ANOVA, Pearson's Correlation Coefficient attached to SPSS Computer System for the process of gathered materials. The results of this investigations are follows 1) A total of 98 times' interactions between nurses and patients were provided during observation of 168 hours. 2) It took them the averaged 264.8 seconds(around 4.4 minutes) per a couple of subjects to interact between nurses and patients during observation of four hours. 3) The aim of interactions between nurses and patients appear that 29 times of injection amounted to 29.6% the most, 27 times of PO around to 27.6% the next most, 25 times of vital check to 25.5% the next most, 17 times of independent nursing works and round to 17.3% the least most. 4) As a result of qualitative analyzing the interactions between nurses and patients by the distinctive method of words were positively recognized in 19 cases with 45.2% and negatively in 23 cases with 54.8%. 5) A total of 2, 193 times. interaction behaviours between nurses and patients were provided. The frequency of these interaction behaviours took place l, 364 times with 62.2% to nurse, and 829 times with 37.8% to patients. 6) The classification of verbal and nonverbal interaction behaviour between nurses and patients indicated that it is amounted to 64.9% for verbal behaviour numbered 1, 423 and 35.1% for nonverbal one numbered 770. 7) The frequency of verbal behaviour between nurses and patients numbered 1, 423 in total. They took place 924 times to nurses and 499 times to patients, it can be also amounted to 64.9% and 35.1% respectively in percentagewise. 8) In interactions between nurses and patients, it turned out that the frequency of nurses' turns, which the present research discovered averaged 16.8 times for four hours, and the verbal behaviours by numbered 9.7 on an average. 9) Nonverbal behaviours between nurses and patients numbered 770 in total, it is assigned 440 times to nurse with 57.1% and 330 times to patients with 42.9%. 10) The investigation releases in formation that the frequency of verbal behaviours between nurses and patients was very much concerned with the age of patients(r=0.422, p<.01) and the number of patients one nurse has under her care(r=-0.356, p<.01). 11) It was found that were deep relationship of the number of a nurses turn with the patients age(r=0.377, p<.01) and the nurses burden of caring patients(r=-0.372, p<.01).

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Possible Causes of Paleosecular Variation and Deflection of Geomagnetic Directions Recorded by Lava Flows on the Island of Hawaii

  • Czango Baag
    • Proceedings of the International Union of Geodesy And Geophysics Korea Journal of Geophysical Research Conference
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    • 2003.05a
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    • pp.20-20
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    • 2003
  • In the summers of 1997 and 1998 and in February of 2000 we made 570 measurements of the ambient geomagnetic field 120 cm above the pavement surface of State Route 130, south of Pahoa, the island of Hawaii using a three-component fluxgate magnetometer. We measured at every 15.2 m (50 feet) interval covering a distance of 6, 310 m (20, 704 ft) where both historic and pre-historic highly magnetic basalt flows underlie. We also collected 197 core samples from eight road cuts, 489 specimens of which were subject to AF demagnetizations at 5 - 10 mT level up to a maximum field of 60 mT. We observed significant inclination anomalies ranging from a minimum of $31^{\circ}$ to a maximum $40^{\circ}$ where a uniform inclination value of $36.7^{\circ}$ (International Geomagnetic Reference Field, IGRF) was expected. Since the mean of the observed inclinations is approximately $35^{\circ}$ we assume that the study area is slightly affected by the magnetic terrain effect to a systematically shallower inclinations for being located in the regionally sloping surface of the southern side of the island (Baag, et al., 1995). We observed inclination anomalies showing wider (spacial) wavelength (160 - 600 m) and higher amplitudes in the historic lava flows area than in the northern pre-historic flows. Our observations imply that preexisting inclination anomalies such as those that we observed would have been interpreted as paleosecular variation (PSV). These inclination anomalies can best be attributed to concealed underground highly magnetic dikes, channel type lava flows, on-and-off hydrothermal activities through fissure-like openings, etc. Both the within- and between-site dispersions of natural remanent magnetization (NRM) are largest (up to ${\pm}7^{\circ}$) above the flows of 1955, while the area of pre-historic flows in the northern part of the study area exhibit the smallest dispersion. Nevertheless, mean inclinations of each historic flow of 1955 and 1790 are almost identical to that of the corresponding present field, whereas mean of NRM (after AF demagnetization) inclinations for each of the four pre-historic lava flow units is twelve to thirteen degrees lower than the present field inclination. We observed three cases of very large inclination variations from within a single flow, the best fitting curves of which are linear, second and third order polynomials each from within a single flow, whereas no present field variations are observed. This phenomena can be attributed to the notion that local magnetic anomalies on the surface of an active volcano are not permanent, but are transient. Therefore we believe that local magnetic anomalies of an active volcano may be constantly modified due to on going subsurface injections and circulations of hot material and also due to wide spacial and temporal distribution of highly magnetic basaltic flows that will constantly modify the topography which will in turn modify the local ambient geomagnetic field (Baag, et al., 1995). Our observations bring into question the general reliability of PSV data inferred from volcanic rocks, because on-going various geologic and geophysical activities associated with active volcano would continuously deflect and modify the ambient geomagnetic field.

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InGaZnO active layer 두께에 따른 thin-film transistor 전기적인 영향

  • U, Chang-Ho;Kim, Yeong-Lee;An, Cheol-Hyeon;Kim, Dong-Chan;Gong, Bo-Hyeon;Bae, Yeong-Suk;Seo, Dong-Gyu;Jo, Hyeong-Gyun
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2009.11a
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    • pp.5-5
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    • 2009
  • Thin-film-transistors (TFTs) that can be prepared at low temperatures have attracted much attention because of the great potential for transparent and flexible electronics. One of the mainstreams in this field is the use of organic semiconductors such as pentacene. But device performance of the organic TFTs is still limited due to low field-effect mobility and rapid degradation after exposing to air. Alternative approach is the use of amorphous oxide semiconductors as a channel. Amorphous oxide semiconductors (AOSs) based TFTs showed the fast technological development, because AOS films can be fabricated at room temperature and exhibit the possibility in application like flexible display, electronic paper, and larges solar cells. Among the various AOSs, a-IGZO has lots of advantages because it has high channel mobility, uniform surface roughness and good transparency. [1] The high mobility is attributed to the overlap of spherical s-orbital of the heavy post-transition metal cations. This study demonstrated the effect of the variation in channel thickness from 30nm to 200nm on the TFT device performance. When the thickness was increased, turn-on voltage and subthreshold swing was decreased. The a-IGZO channels and source/drain metals were deposited with shadow mask. The a-IGZO channel layer was deposited on $SiO_2$/p-Si substrates by RF magnetron sputtering, where RF power is 150W. And working pressure is 3m Torr, at $O_2/Ar$ (2/28 sccm) atmosphere. The electrodes were formed with electron-beam evaporated Ti (30 nm) and Au (70 nm) bilayer. Finally, Al (150nm) as a gate metal was thermal-evaporated. TFT devices were heat-treated in a furnace at 250 $^{\circ}C$ and nitrogen atmosphere for 1hour. The electrical properties of the TFTs were measured using a probe-station. The TFT with channel thickness of 150nm exhibits a good subthreshold swing (SS) of 0.72 V/decade and on-off ratio of $1{\times}10^8$. The field effect mobility and threshold voltage were evaluated as 7.2 and 8 V, respectively.

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Power Enhance Effect on the Hybrid Cell Based on Direct Current Nanogenerator and an Organic Photovoltaic Device

  • Yun, Gyu-Cheol;Sin, Gyeong-Sik;Lee, Geun-Yeong;Lee, Ju-Hyeok;Kim, Sang-U
    • Proceedings of the Korean Vacuum Society Conference
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    • 2013.08a
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    • pp.298-298
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    • 2013
  • Finding renewable and clean energy resources is essential research to solve global warming and depletion of fossil fuels in modern society. Recently, complex harvesting of energy from multiple sources is available in our living environments using a single device has become highly desirable, representing a new trend in energy technologies. We report that when simultaneously driving the fusion and composite cells of two or more types, it is possible to make an affect the other cells to obtain a greater synergistic effect. To understand the coupling effect of photovoltaic and piezoelectric device, we fabricate the serially integrated hybrid cell (s-HC) based on organic solar cell (OSC) and piezoelectric nanogenerator (PNG). The size of increased voltage peaks when OSC and PNG are working on is larger than the case when only PNG is working. This voltage difference is the Voc change of OSC, not the voltage change of PNG and current density difference between these two cases is manifested more clearly. When the OSC and PNG are working in s-HC at the same time, piezoelectric potential (VPNG) is generated in ZnO and theoretical total voltage is sum of voltage of an OSC (VOSC) and VPNG. However, electrons from OSC are influenced by piezoelectric potential in ZnO and current loss of OSC in whole circuit decreases. As a result, VOSC increases temporarily. Current shows the similar behavior. PNG acts a resistance in the whole circuit and current loss occurs when the electrons from OSC pass through the PNG. But piezoelectric potential recover current loss and decrease the resistance of PNG. Our PNG can maintain piezoelectric potential when the strain is held owing to the LDH layer while general PNG cannot maintain piezoelectric potential. During the section that strain is held, voltage enhancement effect is maintained and same effect appeared even turn off the light. Actually at this time, electrons in ZnO nanosheets move to LDH and trapped by the positive charges in this layer. After this strain is held, piezoelectric potential of ZnO nanosheets is disappeared but potential difference which is developed by negative charge dominant LDH layer is remained. This potential acts similar role like piezoelectric potential in ZnO. Electrons from the OSC also are influenced by this potential and the more current flows.

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