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Evaluations of Ecological Habitat, Chemical Water Quality, and Fish Multi-Metric Model in Hyeongsan River Watershed (형산강 수계의 생태 서식지, 화학적 수질 및 어류의 다변수모델 평가)

  • Kim, Yu-Pyo;An, Kwang-Guk
    • Korean Journal of Ecology and Environment
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    • v.43 no.2
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    • pp.279-287
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    • 2010
  • This study was to evaluate ecological conditions of Hyeongsan River watershed from April to September 2009. The ecological health assessments was based on Qualitative Habitat Evaluation Index (QHEI), water chemistry during 2000~2009, and the fish multi-metric model, Index of Biological Integrity (IBI). For the study, the models of IBI and QHEI were modified as 8 and 11 metric attributes, respectively. Values of IBI averaged 25.4 (n=6), which is judged as a "fair" condition (C) after the criteria of Barbour et al. (1999). The distinct spatial variation was found in the IBI. Physical habitat health, based on the values of QHEI, varied from 76 in the downriver (H6) to 150.5 in the headwater (H1) and was evidently more disturbed in the downriver reach. Values of BOD and COD averaged 2.4 $mgL^{-1}$ (range: 0.3~13.8 $mgL^{-1}$) and 4.3 $mgL^{-1}$ (scope: 0.6~12.8 $mgL^{-1}$), respectively during the study period. Total nitrogen (TN) and total phosphorus (TP) averaged 3.0 $mgL^{-1}$ and 103.5 ${\mu}gL^{-1}$, respectively, indicating a severe eutrophication, and the nutrients increased more in the downriver than the headwater. Overall, physical, chemical and IBI parameters showed a typical downriver degradation along main axis of the river from the headwater-to-the downriver. This was mainly attributed to livestock waste and residential influences along with industrial discharge from the urban region.

Effect of Substrata Surface Energy on Light Scattering of a Low Loss Mirror (기판의 표면에너지가 반사경의 산란에 미치는 영향)

  • Lee, Beom-Sik;Yu, Yeon-Serk;Lee, Jae-Cheul;Hur, Deog-Jae;Cho, Hyun-Ju
    • Korean Journal of Optics and Photonics
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    • v.18 no.6
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    • pp.452-460
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    • 2007
  • Ultra-low loss ZERODUR and fused silica mirrors were manufactured and their light scattering characteristics were investigated. For this purpose, ZERODUR and fused silica substrates were super-polished by the bowl feed method. The surface roughness were 0.292 ${\AA}$ and 0.326 ${\AA}$ in rms for ZERODUR and fused silica, respectively. To obtain the high reflectivity, 22 thin film layers of $SiO_2$ and $Ta_2O_5$ were deposited by Ion Beam Sputtering. The measured light scattering of ZERODUR and fused silica mirror were 30.9 ppm and 4.6 ppm, respectively. This shows that the substrate surface roughness is not the only parameter which determines the light scattering of the mirror. In order to investigate the mechanism for additional light scattering of the ZERODUR mirror, the surface roughness of the mirror was measured by AFM and was found to be 2.3 times higher than that of the fused silica mirror. It is believed that there is some mismatch at the interface between the substrate and the first thin film layer which leads to the increased mirror surface roughness. To clarify this, the contact angle measurements were performed by SEO 300A, based on the Giriflaco-Good-Fowkes-Young method. The fused silica substrates with 0.46 ${\AA}$ in its physical surface roughness shows lower contact angle than that of the ZERODUR substrate with 0.31 ${\AA}$. This indicates that the thin film surface roughness is determined by not only its surface roughness but also the surface energy of the substrate, which depends on the chemical composition or crystalline orientation of the materials. The surface energy of each substrate was calculated from a contact angle measurement, and it shows that the higher the surface energy of the substrate, the better the surface roughness of the thin film.

Clinical Study of Acute and Chronic Pain by the Application of Magnetic Resonance Analyser $I_{TM}$ (자기공명분석기를 이용한 통증관리)

  • Park, Wook;Jin, Hee-Cheol;Cho, Myun-Hyun;Yoon, Suk-Jun;Lee, Jin-Seung;Lee, Jeong-Seok;Choi, Surk-Hwan;Kim, Sung-Yell
    • The Korean Journal of Pain
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    • v.6 no.2
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    • pp.192-198
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    • 1993
  • In 1984, a magnetic resonance spectrometer(magnetic resonance analyser, MRA $I_{TM}$) was developed by Sigrid Lipsett and Ronald J. Weinstock in the USA, Biomedical applications of the spectrometer have been examined by Dr. Hoang Van Duc(pathologist, USC), and Nakamura, et al(Japan). From their theoretical views, the biophysical functions of this machine are to analyse and synthesize a healthy tissue and organ resonance pattern, and to detect and correct an abnormal tissue and organ resonance pattern. All of the above functions are based on Quantum physics. The healthy tissue and organ resonance patterns are predetermined as standard magnetic resonance patterns by digitizing values based on peak resonance emissions(response levels or high pitched echo-sounds amplified via human body). In clinical practice, a counter or neutralizing resonance pattern calculated by the spectrometer can correct a phase-shifted resonance pattern(response levels or low pitched echo-sounds) of a diseased tissue and organ. By administering the counter resonance pattern into the site of pain and trigger point, it is possible to readjust the phase-shifted resonance pattern and then to alleviate pain through regulation of the neurotransmitter function of the nervous system. For assessing clinical effectiveness of pain relief with MRA $I_{TM}$ this study was designed to estimate pain intensity by the patient's subjective verbal rating scale(VRS such as graded to no pain, mild, moderate and severe) before application of it, to evaluate an amount of pain relief as applied the spectrometer by the patients subjective pain relief scale(visual analogue scale, VAS, 0~100%), and then to observe a continuation of pain relief following its application for managing acute and chronic pain in the 102 patients during an 8 months period beginning March, 1993. An application time of the spectrometer ranged from 15 to 30 minutes daily in each patient at or near the site of pain and trigger point when the patient wanted to be treated. The subjects consisted of 54 males and 48 females, with the age distribution between 23~40 years in 29 cases, 41~60 years in 48 cases and 61~76 years in 25 cases respectively(Table 1). The kinds of diagnosis and the main site of pain, the duration of pain before the application, and the frequency of it's application were recorded on the Table 2, 3 and 4. A distinction between acute and chronic pain was defined according to both of the pain intervals lasting within and over 3 months. The results of application of the spectrometer were noted as follows; In 51 cases of acute pain before the application, the pain intensities were rated mild in 10 cases, moderate in 15 cases and severe in 26 cases. The amounts of pain relief were noted as between 30~50% in 9 cases, 51~70% in 13 cases and 71~95% in 29 cases. The continuation of pain relief appeared between 6~24 hours in two cases, 2~5 days in 10 cases, 6~14 days in 4 cases, 15 days in one case, and completely relived of pain in 34 cases(Table 5~7). In 51 cases of chronic pain before the application, the pain intensities were rated mild in 12 cases, moderate in l8 cases and severe in 21 cases. The amounts of pain relief were noted as between 0~50% in 10 cases, 51~70% in 27 cases and 71~90% in 14 cases. The continuation of pain relief appeared to have no effect in two cases. The level of effective duration was between 6~12 hours in two cases, 2~5 days in 11 cases, 6~14 days in 14 cases, 15~60 days in 9 cases and in 13 cases the patient was completely relieved of pain(Table 5~7). There were no complications in the patients except a mild reddening and tingling sensation of skin while applying the spectrometer. Total amounts of pain relief in all of the subjects were accounted as poor and fair in 19(18.6%) cases, good in 40(39.2%) cases and excellent in 43(42.2%) cases. The clinical effectiveness of MRA $I_{TM}$ showed variable distributions from no improvements to complete relief of pain by the patient's assessment. In conclusion, we suggest that MRA $I_{TM}$ may be successful in immediate and continued pain relief but still requires several treatments for continued relief and may be gradually effective in pain relief while being applied repeatedly.

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Influence of Land Cover Map and Its Vegetation Emission Factor on Ozone Concentration Simulation (토지피복 지도와 식생 배출계수가 오존농도 모의에 미치는 영향)

  • Kyeongsu Kim;Seung-Jae Lee
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.25 no.1
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    • pp.48-59
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    • 2023
  • Ground-level ozone affects human health and plant growth. Ozone is produced by chemical reactions between oxides of nitrogen (NOx) and volatile organic compounds (VOCs) from anthropogenic and biogenic sources. In this study, two different land cover and emission factor datasets were input to the MEGAN v2.1 emission model to examine how these parameters contribute to the biogenic emissions and ozone production. Four input sensitivity scenarios (A, B, C and D) were generated from land cover and vegetation emission factors combination. The effects of BVOCs emissions by scenario were also investigated. From air quality modeling result using CAMx, maximum 1 hour ozone concentrations were estimated 62 ppb, 60 ppb, 68 ppb, 65 ppb, 55 ppb for scenarios A, B, C, D and E, respectively. For maximum 8 hour ozone concentration, 57 ppb, 56 ppb, 63 ppb, 60 ppb, and 53 ppb were estimated by scenario. The minimum difference by land cover was up to 25 ppb and by emission factor that was up to 35 ppb. From the modeling performance evaluation using ground ozone measurement over the six regions (East Seoul, West Seoul, Incheon, Namyangju, Wonju, and Daegu), the model performed well in terms of the correlation coefficient (0.6 to 0.82). For the 4 urban regions (East Seoul, West Seoul, Incheon, and Namyangju), ozone simulations were not quite sensitive to the change of BVOC emissions. For rural regions (Wonju and Daegu) , however, BVOC emission affected ozone concentration much more than previously mentioned regions, especially in case of scenario C. This implies the importance of biogenic emissions on ozone production over the sub-urban to rural regions.

Assessment of Benthic Environment based on Macrobenthic Community Analysis in Jinhae Bay, Korea (진해만 대형 저서동물군집 분석을 통한 저서환경 평가)

  • Lim, Kyeong-Hun;Shin, Hyun-Chool;Yoon, Seong-Myeong;Koh, Chul-Hwan
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.12 no.1
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    • pp.9-23
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    • 2007
  • To investigate the degree of pollution using the species composition of benthic community and environments, the present study was conducted in Jinhae Bay, May of 1998. In Jinhae Bay, benthic macrofaunal community was investigated on the base of the samples from 67 stations. The main facies of the surface sediment was silty clay and clay. The total species number and the mean density of macrobenthic animals were 255 species and 984 $ind./m^2$, respectively. There were 90 species and 773 $ind./m^2$ of polychaetes as the most major faunal group in Jinhae Bay. At the region between the eastern mouth of Jinhae Bay and Gadeok Is., the species number and density were higher, while lower at the western area of Jinhae Bay. The most dominant benthic macrofauna in Jinhae Bay was the polychaetes, Lumbrineris longifolia(16.9%), and followed by polychaetes Tharyx sp.(6.7%), Clone teres(4.7%), Glycinde sp.(4.2%), bivalves Theora fragilis(4.0%), crustaceans Corophium sp.(4.0%) and so on. The most of the predominant species appeared mainly on the region between the eastern mouth of Jinhae Bay and Gadeok Is. Cluster analysis based on the macrobenthic faunal composition showed that Jinhae Bay could be divided into three station groups: The western Jinhae Bay(Station group A), the mouth of Jinhae Bay(Station groupe B), and offshore area between Gadeok Is. and Geoje Is.(Station group C). The mouth of Jinhae Bay had the highest mean species number and the mean density, and its important species was Lumbrineris longifolia. The offshore area between Gadeok Is. and Geoje Is. had medium mean species number and the mean density. The western Jinhae Bay had the lowest mean species number and the mean density. The distribution of BPI and BC values, used to assess benthic pollution, showed similar patterns. According to the classification proposed by Borja et al.(2000), the stations of the western inner-bay were heavily polluted sites, the stations between mouth of the bay and the offshore area were slightly polluted sites, and the stations of the other area were meanly polluted sites. Benthic community healthiness of the western Jinhae Bay was classified to 'Transitional to pollution' by BC values. The degree of pollution in Jinhae Bay may have extended gradually from the western Jinhae Bay to the mouth of the bay.

Seeking a Better Place: Sustainability in the CPG Industry (추심경호적지방(追寻更好的地方): 유포장적소비품적산업적가지속발전(有包装的消费品的产业的可持续发展))

  • Rapert, Molly Inhofe;Newman, Christopher;Park, Seong-Yeon;Lee, Eun-Mi
    • Journal of Global Scholars of Marketing Science
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    • v.20 no.2
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    • pp.199-207
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    • 2010
  • For us, there is virtually no distinction between being a responsible citizen and a successful business... they are one and the same for Wal-Mart today." ~ Lee Scott, al-Mart CEO after the 2005 Katrina disaster; cited in Green to Gold (Esty and Winston 2006). Lee Scott's statement signaled a new era in sustainability as manufacturers and retailers around the globe watched the world's largest mass merchandiser confirm its intentions with respect to sustainability. For decades, the environmental movement has grown, slowly bleeding over into the corporate world. Companies have been born, products have been created, academic journals have been launched, and government initiatives have been undertaken - all in the pursuit of sustainability (Peattie and Crane 2005). While progress has been admittedly slower than some may desire, the emergence and entrance of environmentally concerned mass merchandisers has done much to help with sustainable efforts. To better understand this movement, we incorporate the perspectives of both executives and consumers involved in the consumer packaged goods (CPG) industry. This research relies on three underlying themes: (1) Conceptual and anecdotal evidence suggests that companies undertake sustainability initiatives for a plethora of reasons, (2) The number of sustainability initiatives continues to increase in the consumer packaged goods industries, and (3) That it is, therefore, necessary to explore the role that sustainability plays in the minds of consumers. In light of these themes, surveys were administered to and completed by 143 college students and 101 business executives to assess a number of variables in regards to sustainability including willingness-to-pay, behavioral intentions, attitudes, willingness-to-pay, and preferences. Survey results indicate that the top three reasons why executives believe sustainability to be important include (1) the opportunity for profitability, (2) the fulfillment of an obligation to the environment, and (3) a responsibility to customers and shareholders. College students identified the top three reasons as (1) a responsibility to the environment, (2) an indebtedness to future generations, and (3) an effective management of resources. While the rationale for supporting sustainability efforts differed between college students and executives, the executives and consumers reported similar responses for the majority of the remaining sustainability issues. Furthermore, when we asked consumers to assess the importance of six key issues (healthcare, economy, education, crime, government spending, and environment) previously identified as important to consumers by Gallup Poll, protecting the environment only ranked fourth out of the six (Carlson 2005). While all six of these issues were identified as important, the top three that emerged as most important were (1) improvements in education, (2) the economy, and (3) health care. As the pursuit and incorporation of sustainability continues to evolve, so too will the expected outcomes. New definitions of performance that reflect the social/business benefits as well as the lengthened implementation period are relevant and warranted (Ehrenfeld 2005; Hitchcock and Willard 2006). We identified three primary categories of outcomes based on a literature review of both anecdotal and conceptual expectations of sustainability: (1) improvements in constituent satisfaction, (2) differentiation opportunities, and (3) financial rewards. Within each of these categories, several specific outcomes were identified resulting in eleven different outcomes arising from sustainability initiatives. Our survey results indicate that the top five most likely outcomes for companies that pursue sustainability are: (1) green consumers will be more satisfied, (2) company image will be better, (3) corporate responsibility will be enhanced, (4) energy costs will be reduced, and (5) products will be more innovative. Additionally, to better understand the interesting intersection between the environmental "identity" of a consumer and the willingness to manifest that identity with marketplace purchases, we extended prior research developed by Experian Research (2008). Accordingly, respondents were categorized as one of four types of green consumers (Behavioral Greens, Think Greens, Potential Greens, or True Browns) to garner a better understanding of the green consumer in addition to assisting with a more effective interpretation of results. We assessed these consumers' willingness to engage in eco-friendly behavior by evaluating three options: (1) shopping at retailers that support environmental initiatives, (2) paying more for products that protect the environment, and (3) paying higher taxes so the government can support environmental initiatives. Think Greens expressed the greatest willingness to change, followed by Behavioral Greens, Potential Greens, and True Browns. These differences were all significant at p<.01. Further Conclusions and Implications We have undertaken a descriptive study which seeks to enhance our understanding of the strategic domain of sustainability. Specifically, this research fills a gap in the literature by comparing and contrasting the sustainability views of business executives and consumers with specific regard to preferences, intentions, willingness-to-pay, behavior, and attitudes. For practitioners, much can be gained from a strategic standpoint. In addition to the many results already reported, respondents also reported than willing to pay more for products that protect the environment. Other specific results indicate that female respondents consistently communicate a stronger willingness than males to pay more for these products and to shop at eco-friendly retailers. Knowing this additional information, practitioners can now have a more specific market in which to target and communicate their sustainability efforts. While this research is only an initial step towards understanding similarities and differences among practitioners and consumers regarding sustainability, it presents original findings that contribute to both practice and research. Future research should be directed toward examining other variables affecting this relationship, as well as other specific industries.

A Conjoint Analysis of Online Information Privacy Concerns: A case in Korea (온라인 프라이버시 침해 우려에 관한 컨조인트 분석 : 한국에서의 사례)

  • Choi, Mi-Young;Lee, Sang-Yong Tom
    • Asia pacific journal of information systems
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    • v.18 no.3
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    • pp.45-65
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    • 2008
  • The rapid growth of the Internet has increased the amount of transmission of personally identifiable information. At the same time, with new Internet related technologies, organizations are trying to collect and access more personal information than before, which in turn makes individuals concern more about their information privacy. For their successful businesses, organizations have tried to alleviate these concerns in two ways: (1) by offering privacy policies that promise certain level of privacy protection; (2) by offering benefits such as financial gains or convenience. In this paper, we interpret these actions in the context of the information processing theory of motivation. This paper follows Hann et al.(2007)'s methods to analyze Internet users privacy concerns in Korea and tries to compare the findings. Our research objectives are as follows: First, we analyze privacy concern mitigation strategies in the framework of the expectancy theory of motivation. Subsequently, we show how the expectancy theory based framework is linked o the conjoint analysis. We empirically validate the predictions that the means to mitigate privacy concerns are associated with positive valences resulting in an increase in motivational score. In order to accommodate real-life contexts, we investigate these means in trade-off situation, where an organization may only be able to offer partially complete privacy protection and/or promotions and/or convenience, While privacy protection (secondary use, improper access) are associated with positive valences, we also find that financial gains can significantly increase the individuals' motivational score of a website in Korea. One important implication of this empirical analysis is that organizations may possess means to actively manage the privacy concerns of Internet users. Our findings show that privacy policies are valued by users in Korea just as in the US or Singapore. Hence, organizations can capitalize on this, by stating their privacy policy more prominently. Also organizations would better think of strategies or means that may increase online users' willingness to provide personal information. Since financial incentives also significantly increase the individuals' motivational score of website participation, we can quantify the value of website privacy protection in terms of monetary gains. We find that Korean Internet users value the total privacy protection (protection against errors, improper access, and secondary use of personal information) as worthy as KW 25,550, which is about US 28. Having done this conjoint analysis, we next adopt cluster analysis methodology. We identify two distinct segments of Korea's internet users-privacy guardians and information sellers, and convenience seekers. The immediate implication of our study is that firms with online presence must differentiate their services to serve these distinct segments to best meet the needs of segments with differing trade-offs between money and privacy concerns. Information sellers are distinguished from privacy guardians by prior experience of information provision, To the extent that businesses cannot observe an individual's prior experience, they must use indirect methods to induce segmentation by self-selection as suggested in classic economics literature of price discrimination, Businesses could use monetary rewards to attract information sellers to provide personal information. One step forward from the societal trends that emphasize the need of legal protection of information privacy, our study wants to encourage organizations and related authorities to have the viewpoints to consider both importance of privacy protection and the necessity of information trade for the growth of e-commerce.

Kinematics and Grip Forces of Professionals, Amateurs and Novices during Golf Putting (퍼팅 시 프로와 아마추어, 초보 골퍼사이의 운동학적 변인과 그립 악력 비교)

  • Choi, Jin-Seung;Kim, Hyung-Sik;Kang, Dong-Won;Kim, Han-Su;Oh, Ho-Sang;Seo, Jeong-Woo;Yi, Jeong-Han;Lim, Young-Tae;Tack, Gye-Rae
    • Korean Journal of Applied Biomechanics
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    • v.21 no.4
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    • pp.405-410
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    • 2011
  • The purpose of this study was to compare the differences in kinematic variables and grip forces among professionals(PG), amateurs(AG), and novice group(NG) during golf putting. The participants consisted of 3 groups based on their playing ability: 8 professional golfers (handicap<5), 8 amateurs (handicap<18) and 8 novice. Each subject attempted 2.1m putts from the hole. 3D motion analysis system(Motion analysis Corp., USA) with 6 high speed cameras and grip force measurement system(Kim et al., 2007) were used to acquired kinematic and force data, respectively. To compare differences among groups, joint angles of upper limbs, trajectory and smoothness by jerk cost function(JC) of putter head and grip forces were used in this study. Results showed that there were significant differences among groups in most of variables such as joint angles, trajectory & smoothness of putter head, and distribution of grip force in both hands. In brief, we confirmed that putting stroke in PG was more accurate and smooth than that in other groups, especially NG, due to their well-controlled upper limbs and keeping grip forces constant in both hands. It can be concluded that due to skilled levels, fundamental differences of putting movement could be identified and these differences might be helpful for improving one's putting skills.

A Study of Root Resorption in Upper and Lower Incisor in Patients following Orthodontic Treatment (교정환자의 교정치료 후 상·하악 전치의 치근흡수에 관한 연구)

  • Shim, Youn-Soo;Kim, Ah-Hyeon;An, So-Youn
    • Journal of dental hygiene science
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    • v.11 no.3
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    • pp.251-255
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    • 2011
  • Objectives One aspect of undesirable outcomes in orthodontic treatment includes excessive resorption of dental roots with mechanotherapy. The purpose of this study was to examine the relationship between treatment duration, adult and adolescent, gender, extraction and non-extraction root resorption after orthodontic treatment. Methods The subjects consisted of 140 orthodontic patients(adult : 70, adolescent : 70) who treated by standard edgewise technique at the three orthodontic hospital and clinic in seoul. Pre-treatment and post-treatment periapical radiographs were examined. The amount of root resorption was assessed for six anterior teeth according to criteria modified from Lupi et al root resorption score. Results Treatment duration was 24.7 months in the adult group and 33.5 months in the adolescents group. Between adult and adolescents group were significantly difference of mean of root resorption score(p<0.05). Female group and extraction group usually had higher prevalence of root resorption, but were not significant differences between the each groups(p>0.05). Conclusions When viewing these results, a lot of root resorption in adult patients appears, especially the maxillary central incisor, lateral incisor root resorption during orthodontic treatment occurs, so be careful and do more research to be done is suggested.

Fabrication of Schottky Device Using Lead Sulfide Colloidal Quantum Dot

  • Kim, Jun-Kwan;Song, Jung-Hoon;An, Hye-Jin;Choi, Hye-Kyoung;Jeong, So-Hee
    • Proceedings of the Korean Vacuum Society Conference
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    • 2012.08a
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    • pp.189-189
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    • 2012
  • Lead sulfide (PbS) nanocrystal quantum dots (NQDs) are promising materials for various optoelectronic devices, especially solar cells, because of their tunability of the optical band-gap controlled by adjusting the diameter of NQDs. PbS is a IV-VI semiconductor enabling infrared-absorption and it can be synthesized using solution process methods. A wide choice of the diameter of PbS NQDs is also a benefit to achieve the quantum confinement regime due to its large Bohr exciton radius (20 nm). To exploit these desirable properties, many research groups have intensively studied to apply for the photovoltaic devices. There are several essential requirements to fabricate the efficient NQDs-based solar cell. First of all, highly confined PbS QDs should be synthesized resulting in a narrow peak with a small full width-half maximum value at the first exciton transition observed in UV-Vis absorbance and photoluminescence spectra. In other words, the size-uniformity of NQDs ought to secure under 5%. Second, PbS NQDs should be assembled carefully in order to enhance the electronic coupling between adjacent NQDs by controlling the inter-QDs distance. Finally, appropriate structure for the photovoltaic device is the key issue to extract the photo-generated carriers from light-absorbing layer in solar cell. In this step, workfunction and Fermi energy difference could be precisely considered for Schottky and hetero junction device, respectively. In this presentation, we introduce the strategy to obtain high performance solar cell fabricated using PbS NQDs below the size of the Bohr radius. The PbS NQDs with various diameters were synthesized using methods established by Hines with a few modifications. PbS NQDs solids were assembled using layer-by-layer spin-coating method. Subsequent ligand-exchange was carried out using 1,2-ethanedithiol (EDT) to reduce inter-NQDs distance. Finally, Schottky junction solar cells were fabricated on ITO-coated glass and 150 nm-thick Al was deposited on the top of PbS NQDs solids as a top electrode using thermal evaporation technique. To evaluate the solar cell performance, current-voltage (I-V) measurement were performed under AM 1.5G solar spectrum at 1 sun intensity. As a result, we could achieve the power conversion efficiency of 3.33% at Schottky junction solar cell. This result indicates that high performance solar cell is successfully fabricated by optimizing the all steps as mentioned above in this work.

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