• 제목/요약/키워드: Expansion Factor

검색결과 846건 처리시간 0.03초

담배잎의 일생에 있어서 RuBisCO 함량과 Protease활성의 변동 (Changes of RuBisCO Content and Protease Activity during the Life Span of Tobacco Leaf)

  • 이학수
    • 한국연초학회지
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    • 제15권1호
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    • pp.63-74
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    • 1993
  • Changes in the amount of ribulose 1, 5-bisphosphate carboxylase/oygenase(=RuBisCO) protein, namely fraction I protein, and the protease activity were determined in the 10th leaf of tobacco(Nicotiana tabacum, var. Ky-57) from 10 days after emergence through senescence at 5 days interval. The amount of RuBisCO per deveined leaf rapidly increased during the early growing season, reached a maximal quantity at the around 20 days after leaf emergence, when the leaf has gone through its most rapid expansion, and began gradually to decrease till 30 days after leaf emergence, thereafter significantly declined to 45 days that the leaf has been dried up partly. The pattern of the ratio of RuBisCO protein to soluble protein in quantity changed similar to that of RuBisCO contents in a leaf, that was 43%, 60%, and 21% at the around 10 days, 20 days, and 45 days, respectively. And RuBisCO contents was linearly correlated with the concentration of chlorophyll(r=0.98) throughout the life span of the leaf. So, it was assumed that the leaf color can be a useful indicator for judging whether RuBisCO contents higher or not in tobacco leaves without homogenization. On the other hand, the protease activities for degradation of casein were assayed at pH 5.5. 7.0. and 8.5 with crude extracts desalted on Sephadex G-25. The highest caseolytic activity was found at pH 5.5 throughout the life sawn of the leaf. Also, the activity at 5.5 became gradually to increase from 30 days after leaf emergence, when RuBisCO protein had became to disappear and remarkably increased in the last stage of senescence, although nitrogen contents of the leaf had reached low levels. The caseolytic activity at pH 5.5 was in negative correlation with RuBisCO contents throughout the life span of the leaf, but not in lineality between them. In other words, the caseolytic activity increased in a rapid exponential manner when RuBisCO contents had reached some low levels. These results showed that the leaf age, namely harvesting time, is a very important factor for the production of the tobacco leaf containing higher RuBisCO protein. It was concluded that the practical harvesting time is between 20 days and 30 days after the leaf emergence from the present results.

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Comparative analysis of two methods of laser induced boron isotopes separation

  • K.A., Lyakhov;Lee, H.J.
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
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    • pp.407-408
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    • 2011
  • Natural boron consists of two stable isotopes 10B and 11B with natural abundance of 18.8 atom percent of 10B and 81.2 atom percent of 11B. The thermal neutron absorption cross-section for 10B and 11B are 3837 barn and 0.005 barn respectively. 10B enriched specific compounds are used for control rods and as a reactor coolant additives. In this work 2 methods for boron enrichment were analysed: 1) Gas irradiation in static conditions. Dissociation occurs due to multiphoton absorption by specific isotopes in appropriately tuned laser field. IR shifted laser pulses are usually used in combination with increasing the laser intensity also improves selectivity up to some degree. In order to prevent recombination of dissociated molecules BCl3 is mixed with H2S 2) SILARC method. Advantages of this method: a) Gas cooling is helpful to split and shrink boron isotopes absorption bands. In order to achieve better selectivity BCl3 gas has to be substantially rarefied (~0.01%-5%) in mixture with carrier gas. b) Laser intensity is lower than in the first method. Some preliminary calculations of dissociation and recombination with carrier gas molecules energetics for both methods will be demonstrated Boron separation in SILARC method can be represented as multistage process: 1) Mixture of BCl3 with carrier gas is putted in reservoir 2) Gas overcooling due to expansion through Laval nozzle 3) IR multiphoton absorption by gas irradiated by specifically tuned laser field with subsequent gradual gas condensation in outlet chamber It is planned to develop software which includes these stages. This software will rely on the following available software based on quantum molecular dynamics in external quantized field: 1) WavePacket: Each particle is treated semiclassicaly based on Wigner transform method 2) Turbomole: It is based on local density methods like density of functional methods (DFT) and its improvement- coupled clusters approach (CC) to take into account quantum correlation. These models will be used to extract information concerning kinetic coefficients, and their dependence on applied external field. Information on radiative corrections to equation of state induced by laser field which take into account possible phase transition (or crossover?) can be also revealed. This mixed phase equation of state with quantum corrections will be further used in hydrodynamical simulations. Moreover results of these hydrodynamical simulations can be compared with results of CFD calculations. The first reasonable question to ask before starting the CFD simulations is whether turbulent effects are significant or not, and how to model turbulence? The questions of laser beam parameters and outlet chamber geometry which are most optimal to make all gas volume irradiated is also discussed. Relationship between enrichment factor and stagnation pressure and temperature based on experimental data is also reported.

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도시 내 묵논습지 생물서식 특성 및 관리방안 -북한산국립공원 울대습지를 대상으로- (Habitat Characteristics and Management of Abandoned Rice Paddy Field Wetlands in Mountain - In Case of the Uldae Wetland in Bukhansan National Park -)

  • 유소연;허명진;한봉호;최진우
    • 한국환경복원기술학회지
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    • 제21권4호
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    • pp.11-23
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    • 2018
  • The purpose of this study is to identify the ecological characteristics and biological interactions between species of the abandoned rice paddy field in mountainous areas and to suggest a management strategy for stable food chain formation and biodiversity enhancement. The study site is located in Uldae wetland of Songchu district Bukhansan National Park, site characteristics and biological habitat characteristics were identified through site survey and literature survey. With regard to physical environment, among geographical features, the Uldae Wetland and the neighborhood inside the basin was a gently sloping area($5{\sim}15^{\circ}$). And 64.0% of basin faced the north. With regard to water environment, the Uldae Wetland was wetland of rainfed paddy field depending on precipitation and the system of stream flowing into the wetland from valley. According to the results of examining flora in plant ecology, in general, they were herbaceous wetland species. 88.6% of existing plants inside the Uldae Wetland basin was a forest in the mountain. And Quercus spp. community and Pinus densiflora community accounted for 64.6% of that, and was dominant. Except for that, Salix koreensis community was distributed. The existing vegetation of Uldae Wetland inhabited wetland species and terrestrialization indicator species, and it was thought that partial terrestrialization inside the Uldae Wetland was in progress after the discontinuation of paddy cultivation, such as the expansion of Salix koreensis distribution area. In the status of appearing faunae in the Uldae Wetland with regard to wildbirds of appearing principal species, The Uldae wetland was based on a abandoned rice paddy field various wildlife, and was a wildlife feeding, spawning, and resting place. The water environment was an important factor in maintaining the wetland living creatures function, habitat of waterbirds and benthic macroinvertebrates, amphibians and odonate are spawning ground and habitat, it was affecting the vegetation ecosystem based on wetlands. In order to maintain the diversity of wildlife, it was important to maintain smooth water supply and water level. A stable food chain will be formed and the Uldae wetland biodiversity will be abundant by establishing the relationship between the species of Uldae wetland, which is abandoned rice paddy field, and the habitat environment favored by species belonging to the ecosystem stepwise linkage. The ecological characteristics of the Uldae wetlands and the relation between the species were analyzed and the environmental conditions were reflected in the planning and management plan of Uldae wetland ecology.

신규 복합 미디어 기업의 부상과 제작자 엑서더스: 종합편성채널 승인 이후 방송제작 부문의 창의성 재배치 동학 (Emerging Media Conglomerates and Producers' Exodus: The Dynamics of Creativity Relocations in the South Korean Broadcasting Production Sector after the Introduction of New General Programming Channels)

  • 정준희
    • 한국언론정보학보
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    • 제66권
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    • pp.28-58
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    • 2014
  • 2010년 말의 종편 승인 결정에서 현재 시점에 이르기까지 한국 방송산업은 상당 수준의 구조적 변동을 겪고 있다. 그 가운데 가장 특징적인 모습 하나는 단단한 수직결합 체계를 통해 국내 방송영상산업에서 강력한 콘텐츠 지배력을 유지해오던 지상파 제작 단위로부터 핵심 인력이 대규모로 유출되고 있는 현상일 것이다. 이 연구는 이와 같은 제작자 엑서더스 현상의 배후로서, 상업적 거대 미디어기업을 통해 방송부문에서 시장논리를 확대하려는 목적의식적 제도설계의 존재를 지목하고, 이와 같은 외부 요인이 방송산업 내부의 다양한 요인들과 맞물려 어떠한 양상을 빚어내고 있는지를 분석한다. 그 결과, 지상파 잔류보다는 이탈이 개인적 사회적 보상 차원에서 더 다양하고 더 큰 긍정유인을 제공한다고 본 제작자들 나름의 합리적 선택을 매개로 현재와 같은 대규모 이탈이 발생되었음을 확인하게 된다. 그러나 일부 복합 미디어 기업을 통해 진행되고 있는 이러한 창의성 재배치 과정이, 장기적으로 제작자들에게 더 많은 기회와 가능성을 보장하는 방향으로 귀결될지에 대해서는 다양한 의문이 제기된다. 이에 이 연구는 현재의 제도적 설계에 내재한 문제점을 지적하고, 이를 개선하기 위한 노력을 촉구한다.

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한국인 국제결혼의 설명틀과 혼인 및 이혼신고자료의 분석 (A Conceptual Scheme of International Marriage of Koreans and Analyses of the Marriage and Divorce Registration Data)

  • 김두섭
    • 한국인구학
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    • 제29권1호
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    • pp.25-56
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    • 2006
  • 이 논문은 혼인 및 이혼신고자료를 활용하여 1990년 이후 한국인의 국제결혼 증가추이와 이에 관련되는 사회인구학적 특성들을 살펴보기 위한 것이다. 이 논문은 국제결혼의 증가를 혼인력 변화의 한 단면으로 규정하고 그 인과구조에 관한 설명 틀을 제시하고 있다. 국제결혼의 급격한 증가를 초래한 주요 원인으로는 출산력의 지속적인 저하, 출생성비의 상승, 농촌-도시 인구이동, 양성평등 관념의 확산과 세계화가 강조되었다. 이 논문의 분석에 사용된 주요 자료는 $1999{\sim}2004$년 혼인신고자료와 $2000{\sim}2004$년의 이혼신고자료이다. 이 논문은 국제결혼한 부부들의 연령, 초혼 여부, 교육, 직업, 거주지 등의 특성을 분석하는데 초점을 맞추었다. 그리고 이혼한 부부의 인구학적 특성에 관한 분석도 이루어졌다. 이 연구의 분석결과는 국제결혼의 다양성이 그동안 간과되어 왔다는 사실을 확인해 준다. 한국 남자와 여자의 국제결혼은 부부의 사회인구학적 특성에서 확연하게 대비된다. 그리고 외국인 배우자의 국적에 따라서도 커다란 차이가 발견된다. 혼인적령인구의 성비불균형으로 인하여 혼인시장에 가해진 압박에 의해 촉진된 국제 결혼은 주로 한국 남자와 중국, 동남아시아 및 구소련연방 국가의 여자와의 결혼에 적용될 수 있다. 이에 비해 한국 남자와 선진국 여자의 결혼이나 한국 여자의 국제결혼은 가치관의 변화와 세계화에 따른 인적교류의 확대에 기인하는바 크다고 판단된다.

온라인 정치참여: 국내·외 연구동향 (A Critical Review on the Study of Online Political Participation: Focused on the Demestic and International Issues)

  • 민희;윤성이
    • 정보화정책
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    • 제22권2호
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    • pp.3-18
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    • 2015
  • 본 연구는 국내의 온라인 정치참여 연구 쟁점을 해외 연구 동향과의 비교를 통해 살펴보고, 기존 연구의 한계 및 전망에 대해 논의한다. 구체적으로, 본 연구는 국내의 온라인 정치참여 연구를 '누가' 참여하는가에 중점을 둔 시각으로 본다. 반면, 해외의 온라인 정치참여 연구를 새로운 참여 '유형'은 무엇인가에 중점을 둔 시각으로 본다. 즉, 기존 연구는 참여자의 확장에 초점을 맞추면서 온라인 미디어가 수용자 중심의 자발적 참여 모델을 촉진하는 기회구조로서 작용하는 것에 보다 관심을 보였다. 그리고 민주화로 인한 급격한 시민사회의 참여 분출과 민주화 이후 지속된 제도정치에 대한 불신이 온라인 미디어의 이러한 역할을 더욱 자극했다. 그런데, 국내 연구가 이 같은 참여자의 확장에 초점을 맞추다 보니 새로이 나타나는 온라인 정치참여를 개념화하고 유형화하는 데는 소홀했다. 이제는 온라인 정치참여를 더욱 다층적으로 관찰하고 이론적으로 개념화하려는 노력이 필요하다. 또한 '참여하는 자' 못지않게 '참여하지 않는 자'에 대해서도 관심을 기울여야 한다. 지금의 미디어 환경이 과거에 비해 자발적으로 정치에 참여하지 않는 자를 양산시키는 측면도 있기 때문이다. 이렇게 되면 우리는 앞으로 정보 격차를 넘어 민주주의의 격차를 고민해야 할 상황과 대면하게 될지도 모른다.

Characteristics and Geoeffectiveness of Small-scale Magnetic Flux Ropes in the Solar Wind

  • Kim, Myeong Joon;Park, Kyung Sun;Lee, Dae-Young;Choi, Cheong-Rim;Kim, Rok Soon;Cho, Kyungsuk;Choi, Kyu-Cheol;Kim, Jaehun
    • Journal of Astronomy and Space Sciences
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    • 제34권4호
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    • pp.237-244
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    • 2017
  • Magnetic flux ropes, often observed during intervals of interplanetary coronal mass ejections, have long been recognized to be critical in space weather. In this work, we focus on magnetic flux rope structure but on a much smaller scale, and not necessarily related to interplanetary coronal mass ejections. Using near-Earth solar wind advanced composition explorer (ACE) observations from 1998 to 2016, we identified a total of 309 small-scale magnetic flux ropes (SMFRs). We compared the characteristics of identified SMFR events with those of normal magnetic cloud (MC) events available from the existing literature. First, most of the MCs and SMFRs have similar values of accompanying solar wind speed and proton densities. However, the average magnetic field intensity of SMFRs is weaker (~7.4 nT) than that of MCs (~10.6 nT). Also, the average duration time and expansion speed of SMFRs are ~2.5 hr and 2.6 km/s, respectively, both of which are smaller by a factor of ~10 than those of MCs. In addition, we examined the geoeffectiveness of SMFR events by checking their correlation with magnetic storms and substorms. Based on the criteria Sym-H < -50 nT (for identification of storm occurrence) and AL < -200 nT (for identification of substorm occurrence), we found that for 88 SMFR events (corresponding to 28.5 % of the total SMFR events), substorms occurred after the impact of SMFRs, implying a possible triggering of substorms by SMFRs. In contrast, we found only two SMFRs that triggered storms. We emphasize that, based on a much larger database than used in previous studies, all these previously known features are now firmly confirmed by the current work. Accordingly, the results emphasize the significance of SMFRs from the viewpoint of possible triggering of substorms.

리더와의 접촉빈도와 심리적 거리가 직무 디스트레스에 미치는 영향: 구성원이 인지하는 셀프리더십의 매개효과 (Contact Frequency and Psychological Distance between Leaders: Job Distress and Mediation through Employees' Perceived Self-Leadership)

  • 양회창;전준호;박종록
    • 유통과학연구
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    • 제12권6호
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    • pp.41-48
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    • 2014
  • Purpose - This study aims to investigate a solution to reduce the negative reactions arising from the performance of duties or the job distress of workers in the service industry, because human resource statistics regarding workers in the service sector have been unreported, while concerns regarding exposure to emotional exertion and poor working conditions have been continuously increasing. Research design, data, and methodology - This study specifically focused on workers in highway service areas. It differs from previous studies because it involves the perspective of the person-organization fit and regards workers' cognition of leaders through the psychological distance toward the leader and the contact frequency between workers and leaders within the framework of the leader-individual fit. Moreover, this study highlights the role of the self-leadership of workers as an important factor that becomes manifested in the individual-level fit to the organization. Hence, this study investigates whether the positive role of the above factors, in turn, could reduce job distress. Workers from highway service areas in Gyeonggi-do province provided data; 141 valid questionnaires are collected. SPSS 19.0 and AMOS 19.0 were used to test the reliability and validity of constructs. Simple regression, multiple regression, and 3 step mediation tests were used to test the hypotheses after the correlation tests. Results - Results indicated that leader-member contact frequency and psychological distance have negative effects on job distress but positive effects on self-leadership. A mediation test revealed that self-leadership, in the relationships between contact frequency and job distress and between psychological distance and job distress, resulted in partial mediation and full mediation, respectively. Conclusions - The result can be understood through two different possible explanations. First, service area workers generally possess a positive perspective toward their leaders. This can be interpreted to mean that increased contact frequency and psychological distance would be considered as supports from the leader, rather than intrusive controls or management schemes. Therefore, the management in highway service areas should invest efforts in increasing contact frequency as well as maximizing psychological similarities by adopting the viewpoints of workers in terms of moral and ethical management, to reduce the workers' job distress. The results relating to self-leadership also indicate that increased contact frequency must be accompanied by intentions for the effective promotion of workers' self-leadership. It also signifies the necessity of a strategic approach by leaders to induce workers to perceive "in-group"ness as suggested both by the similarity-attraction theory and by the social identity theory. In addition, the results of the mediation test of self-leadership indicate that because workers' self-leadership activates upon increased contact frequency by the leader, it should not be a means of control and should not be utilized only from the perspective of management. It is also suggested that strategies such as transfer of authority could have a positive effect in promoting the expansion of self-influence from workers.

Mitochondrial DNA를 이용한 동북아시아 학꽁치 Hyporhamphus sajori의 유전적 다양성과 집단 구조 (Low Genetic Diversity and Shallow Population Structure of the Japanese Halfbeak Hyporhamphus sajori Revealed from Mitochondrial DNA in the Northeast Asia)

  • 곽우석
    • 한국어류학회지
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    • 제31권4호
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    • pp.187-194
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    • 2019
  • 학꽁치(Hyporhamphus sajori)의 유전적 다양성과 집단구조를 조사하기 위해 동북아시아에서 시료를 채집하여 mitochondrial DNA control region (mtDNA CR)을 분석하였다. 시료는 중국(Liaoning), 한국(통영), 일본(Wakasa Bay) 3곳에서 총 70개체를 채집했고, 일본 3곳(Wakasa Bay, Toyama Bay and Mikawa Bay)에서 분석된 47개체의 mtDNA CR 염기서열을 Genbank에서 다운로드했다. 분석결과 총 358 bp가 나타났고, 7개의 변이와 함께 haplotype이 7개 확인되었다. Haplotype diversity과 nucleotide diversity는 각각 0~0.295±0.156 및 0~0.0009±0.0011이고, main haplotype을 94%의 개체가 공유했다. 매우 낮은 haplotype diversity와 nucleotide diversity 그리고 starlike minimum spanning tree는 집단이 최근에 병목현상을 거친 후, 팽창되었음을 나타낸다. 집단 간에 Pairwise FST 값은 낮고 유의하지 않은 것으로 나타났고, 이것은 집단 간 gene flow가 있음을 시사한다. 학꽁치의 genetic homogenity는 부유조와 해류가 주요 원인으로 생각된다.

부산시 도심 노후화 진단에 관한 연구 (A Study of the Diagnosis of Downtown Deterioration in Busan)

  • 권일화;남광우
    • 한국지리정보학회지
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    • 제16권4호
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    • pp.39-53
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    • 2013
  • 효율적인 도시공간구조 형성은 에너지 절감 및 친환경적 측면에서 중요한 요소임에도 불구하고 핵심요소인 도심 및 부도심의 관리는 도시 활동의 변동성과 복잡성으로 인해 점차 어려워지고 있다. 부산의 경우 1960년 이후 도시의 급속한 경제성장으로 인한 도심 규모의 확대 및 인구과밀화 속에서 20년 단위의 도시기본계획 이외에 도심 기능에 대한 전문적인 진단이나 관리 등에 대한 체계적인 접근은 매우 부족하였다. 효율적인 도심지역의 관리를 위해서는 우선적으로 도심기능의 수요 및 노후 예측을 위한 체계적인 도심 모니터링이 필요하다. 이에 본 연구는 도심재생측면에서의 도심지역 노후 진단을 통해 현재 도심의 현황을 파악함과 동시에 향후 도심 관리를 위한 공간정보의 활용방안을 제시하고자 한다. 분석지표로는 물리적, 경제적, 사회적 지표로 나누어 현황을 살펴본 후, 미시적 접근으로 경제적 지표를 활용하여 부산시 서면 도심지역의 경제적 노후를 세부적으로 살펴보았다. 분석 결과 인구분포나 토지이용 측면에서 교외화 단계를 지나 비효율적 분산화 단계가 지속되고 있는 것으로 나타났다. 이는 도심 및 부도심의 기능 강화의 필요성을 의미하며 이에 본 연구는 보다 미시적 관점에서 도심지역을 진단하고 분석된 자료를 바탕으로 도심 지역의 문제점과 도심기능의 강화 방향을 제시하고자 한다.