• 제목/요약/키워드: Z20

검색결과 1,499건 처리시간 0.031초

성 pheromone에 의한 이화명나방의 교미교란에 관한 연구 (Field Study on Mating Confusion of Synthetic Sex Pheromone in the Striped Rice Borer, Chilo suppressalis (Lepidoptera: Pyralidae))

  • 이정운;박중수;고현관;김정한;전종갑
    • 한국응용곤충학회지
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    • 제20권1호
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    • pp.25-30
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    • 1981
  • 성 pheromone을 이용한 이화명나방의 교미교란효과를 구명하고저 합성 성 pheromone, (Z)-11-hexadecenal과 (Z)-13-octadecenal을 4,5 : 1로 공시하여 본 시험을 야외에서 수행한 결과 1화기에는 30a당 합성성 pheromone 29.3g 처리한 구에서 $90.4\%$의 교미교란효과가 인정되었고 2화기에는 $20m^2$당 합성 성 pheromone 33mg 처리까지도 교란효과가 있었다.

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Detection of Unbalanced Voltage Cells in Series-connected Lithium-ion Batteries Using Single-frequency Electrochemical Impedance Spectroscopy

  • Togasaki, Norihiro;Yokoshima, Tokihiko;Oguma, Yasumasa;Osaka, Tetsuya
    • Journal of Electrochemical Science and Technology
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    • 제12권4호
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    • pp.415-423
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    • 2021
  • For a battery module where single cells are connected in series, the single cells should each have a similar state of charge (SOC) to prevent them from being exposed to an overcharge or over-discharge during charge-discharge cycling. To detect the existence of unbalanced SOC cells in a battery module, we propose a simple measurement method using a single-frequency response of electrochemical impedance spectroscopy (EIS). For a commercially available graphite/nickel-cobalt-aluminum-oxide lithium-ion cell, the cell impedance increases significantly below SOC20%, while the impedance in the medium SOC region (SOC20%-SOC80%) remains low with only minor changes. This impedance behavior is mostly due to the elementary processes of cathode reactions in the cell. Among the impedance values (Z, Z', Z"), the imaginary component of Z" regarding cathode reactions changes heavily as a function of SOC, in particular, when the EIS measurement is performed around 0.1 Hz. Thanks to the significant difference in the time constant of cathode reactions between ≤SOC10% and ≥SOC20%, a single-frequency EIS measurement enlarges the difference in impedance between balanced and unbalanced cells in the module and facilitates an ~80% improvement in the detection signal compared to results with conventional EIS measurements.

Curing efficiency of various resin-based materials polymerized through different ceramic thicknesses and curing time

  • Lee, Jung-Won;Cha, Hyun-Suk;Lee, Joo-Hee
    • The Journal of Advanced Prosthodontics
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    • 제3권3호
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    • pp.126-131
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    • 2011
  • PURPOSE. The aim of this in vitro study was to examine the curing efficiency of various resin-based materials polymerized through ceramic restorations with 3 different thicknesses. Curing efficiency was evaluated by determining the surface microhardness (VHN) of the resin specimens. MATERIALS AND METHODS. Four kinds of resin materials were used. Z350 (3M ESPE $Filtek^{TM}$ Z350: A2 Shade), Z250 (3M ESPE $Filtek^{TM}$ Z250: A2 Shade) and $Variolink^{(R)}$ II (VL: Ivoclar vivadent, base: transparent) either with or without a self-curing catalyst (VLC: Ivoclar vivadent, catalyst: low viscosity/transparent) were filled into the silicone mold (10 mm diameter, 1 mm thick). They were cured through ceramic discs (IPS e.max Press MO-0 ingot ivoclar vivadent, 10 mm diameter, 0.5, 1 and 2 mm thicknesses) by LED light-curing units for 20 and 40 seconds. Vicker's microhardness numbers (VHNs) were measured on the bottom surfaces by a microhardness tester. Data were analyzed using a 3-way analysis of variance (ANOVA) at a significance level of 0.05. RESULTS. The thickness of ceramic disc increased, the VHNs of all four resin types were decreased (P<.05). The mean VHN values of the resins light cured for 40 seconds were significantly higher than that of LED for 20 seconds in all four resin materials (P<.05). VLC showed significantly higher VHN values than VL regardless of other conditions (P<.05). Z350 and Z250 showed higher values than VL or VLC (P<.01). CONCLUSION. Thinner ceramic disc with increased curing time resulted higher VHN values of all resin materials. The use of a catalyst produced a greater hardness with all polymerization methods. Restorative resin materials (Z350, Z250) showed higher VHN values than resin cement materials (VL, VLC).

피라미속(잉어목, 잉어과) 어류의 계통분류학적 연구 II. Zacco속 및 Candidia속 어류의 계통적 유연관계 (Systematic Study on the Genus Zacco (Pisces, Cyprinidae). II. Phylogenetic Relationships of the Genera Zocco and Candidia)

  • 민미숙;양서영
    • 한국동물학회지
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    • 제34권4호
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    • pp.571-584
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    • 1991
  • 잉어과(Gyprinidae)의 Zocco속 어류 4종과 Candidia속 어류 1종에 대한 종간 유연관계와 종분화 연대측정 및 이들의 지질학적 분포경로를 밝히기 위하여 한국, 일본 및 대만에서 채집된 개체를 대상으로 전기영동법에 의한 유전자 분석을 하였다. 각 종의 지역별(한국, 일본, 대만) 집단간 유전적 유연관계를 분석한 결과 평균 유전적 근연치는 90% 이상이었다. Z. temmincki의 경우 일본집 단들은 한국의 A-type 집단과는 유연관계가 가까왔으나 한국의 B-type과는 유전적 차이가 현저하러다. Z. PlaD여5의 경우 한국집단과 일본집단사이의 유연관계는 S = 0.852였고, 한국집단과 대만집단 사이는 5 = 0.672, 일본집단과 대만집단 사이는 S = 0.751로서 지리적으로 현저한 차이를 업였다. Z. pochycephalus 3개 집단간의 유전적 근인치는 S = 0.963이었고 Candidia borbota 2개 집단간은 S = 0.946이었다. 종간의 유전적 근연환계를 비교한 결과 Candidia borbota와 Z. temmincki사이는 S = 0.608, Z. pluDpus와 1. pachycephalus사이는 S = 0.612였으나, Z. temmincki와 Z. platypus사이는 S = 0.441, Z. temmincki 와 Z. pochycepholus 사이는 S = 0.350이었고, Z. plotpus와 Condfda barbata사이는 S = 0.328로서 이들 사이에는 현저한 유전적 차이가 있었다. 각 종간의 롱분화 연대를 추산한 결과 이들은 약 480만년 전인 Pliocene 초기에 공통 조상종에서 분화하여 Z. temmincki, Candidia borbato group과 Z. plotypus, Z. pochycepholus group으로 분리되었고 약 260만년 전인 Pliocene 후기에 Z. temminc소와 Candidia borbota로 분화되었다고 추산되며 약 80만년 전인 Pleistocene시기에 남 temmincki B-type에서 h-type이 분화되었다짙 여겨진다. 한편 또 다른 한 단opP은 약 230만년 전인 열iocene후기에 대만 지역의 Z. plotypas에서 Z. pochvcepholus가 분화된 후 현재에 이르렀다고 추정된다. Z. platypus는 약150만년 이전인 초기 Pleistocene시기에 대만지역에서 한국 및 일본집단으로 분리되었다고 보며 이들 한국집단과 일본집단은 약 50만년 전 Pleistocene의 Middle기에 고황하 수계를 거쳐 현재의 분포 상황에 이르렀다고 여겨진다. 한편 대. temmin체과의 B-type에서 저온 적응으로 분화되었다고 추측되는 A-type은 약 20만년 전인 Pleistocene의 Riss기에 역시 고황하 수계를 통하여 한국과 일본으로 분포하여 현재에 이르렀다고 사료된다.

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적도 태평양 아표층 자료의 시계열 분석 및 표층 수온 예측 (Time Series Analysis of the Subsurface Oceanic Data and Prediction of the Sea Surface Temperature in the Tropical Pacific)

  • 장유순;이다운;윤용훈;서장원
    • 한국지구과학회지
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    • 제26권7호
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    • pp.706-713
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    • 2005
  • 엘니뇨현상과 관련된 해양 아표층 변동성을 조사하기 위해 1980년부터 2004년까지의 적도 해역의 20도 등온선 깊이(Z20)와 난수질량(WWV) 자료를 분석하였다. 주성분 분석, 합성 분석 및 교차상관 분석 결과, 아표층 시계열 자료는 Nino3.4 SST와 유의미한 시간 지연을 가지고 강한 상관성을 보였다. 이 결과는 아표층 해양 변수가 엘니뇨현상에 유용한 예측 인자임을 시사한다. 분석된 결과를 근거로 1996년부터 2004년까지 Nino3.4 SST를 예측하기 위해 신경망 예측 모델을 구성하였다. 해상풍을 입력 자료로 사용하였을 경우 보다 WWV를 적용하였을 때 3개월 이하의 단기 예측을 제외하고 모든 예측 시간에서 더 우수한 예측력을 보였으며, 5-8개월의 예측에 있어서는 기존의 여러 통계 모델 결과보다 예측 성능이 우수함을 확인하였다.

잘피의 광합성에 대한 중금속 및 TBT의 독성 영향과 중금속 흡수에 대한 연구 (Preliminary Study on the Toxicity and Transfer of Heavy Metals and Tributyltin to Seagrass Zostera marina)

  • 최태섭;김광용;이병권;이정석
    • ALGAE
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    • 제20권2호
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    • pp.157-166
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    • 2005
  • Uptake kinetics of Cd and Zn by leaves and rhizome of the seagrass Zostera marina were examined in controlled laboratory radiotracer experiments. Subsequently, acute toxicity of Cd, Cu and TBT on photosynthetic quantum yield (ΔF/Fm’ of Z. marina were determined, and the differential sensitivities of rapid light curve (RLC) to those harmful substances were also compared. All measurements on photosynthetic activity were determined by chlorophyll a fluorescence method using pulse amplitude modulation (PAM). Metal uptake by Z. marina was saturated with increasing exposure time in leaves and rhizomes. Uptake of Zn by Z. marina was faster than that of Cd. Metal uptake rates in Z. marina decreased with the increase of dissolved metal concentrations and also with the increase of biomass. The adverse effect of TBT on effective quantum yield was stronger than other pollutants. Average acute toxicity on the RLC of the seagrass exposed to TBT and two heavy metals (Cd and Cu) was going to decrease as follows: TBT > Cd > Cu. Our preliminary results in this study suggested that Z. marina potentially can be used as a biomonitor of harmful substances contamination in coastal waters.

원형대칭 빛살 Z-스캔 방법에 의한 광학적 비선형 굴절율 측정 (Measurements of optical nonlinear refractive index through the Z-scan method with circular symmetric beam)

  • 김기훈;임용식;박종대;김칠민;조창호
    • 자연과학논문집
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    • 제7권
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    • pp.11-17
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    • 1995
  • 미소 반도체 $Bil_3$ 콜로이드의 광학적 비선형 굴절율을 원형 대칭 빛살을 사용한 Z 스캔 방법으로 측정하였다. 파장 $0.532\mum$, 펄스폭 20ns에서 비선형 굴절율은 주로 열적 요인에 의한 것이었으며, 그 크기는 -1.53 x $10^12($cm^2/W) 이었고, 비선형 흡수율 크기는 7.1 x $10^8$ (cm/W) 이었다.

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Delayed Analysis of Hydrogen-Methane Breath Samples

  • Willemsen, Marjolein;Van De Maele, Kristel;Vandenplas, Yvan
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • 제25권1호
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    • pp.13-20
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    • 2022
  • Purpose: Hydrogen-methane breath tests are used to diagnose carbohydrate malabsorption and small intestinal bacterial overgrowth. The COVID-19 pandemic has driven the modification of procedures as breath tests are potentially aerosol-generating procedures. We assessed the effect of delayed analysis of breath samples, facilitating the at-home performance of breath testing. Methods: Children provided two breath samples at every step of the lactose breath test. The samples were brought back to the clinic, and one set of samples was analyzed immediately. The second set was stored at room temperature and analyzed 1-4 days later. Results: Out of the 73 "double" lactose breath tests performed at home, 33 (45.8%) were positive. The second samples were analyzed 20 to 117 hours after the first samples (41.7±24.3 hours). There was no significant difference in the hydrogen concentration between the first and second sets (Z=0.49, p=0.62). This was not the case for methane, which had a significantly higher concentration in the second breath samples (Z=7.6). Conclusion: Expired hydrogen levels remain stable in plastic syringes if preserved at room temperature for several days. On the other hand, the delayed analysis of methane appeared to be less reliable. Further research is needed to examine the impact of delayed analysis on methane and hydrogen concentrations.

밀레니얼과 Z세대의 리빙랩 전망에 대한 정책 제안 (Policy Suggestions for Prospective Living Labs for Millennials and Generation Z)

  • 조윤정
    • 디지털산업정보학회논문지
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    • 제20권2호
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    • pp.91-108
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    • 2024
  • The purpose of this study is to investigate factors influencing the prospects of living labs among Millennials and Generation Z and to provide policy suggestions. This study proposed a comprehensive framework to investigate the influence of citizen awareness, perceived definition, willingness to participate, the role of local government. and expected satisfaction. This study employed an online survey conducted by a well-known research organization. Factor and regression analysis were utilized for data analysus. The results of this study indicate that the effects of citizen awareness, willingness to participate, the role of local government, and expected satisfaction on the prospects for living labs were significant for Millennials, whereas the effects of perceived definition and expected satisfaction on the prospects for living labs were significant for Generation Z. This study suggests the importance of developing better policies to create prospective living labs for real-world environments. This includes preparing policies for the development of future-oriented living labs, establising innovative living labs for practical applications, and designining future-realy living labs to address real-world challenges.

Low-Z Particle Electron Probe X-ray Microanalysis를 이용한 2001년 서울시 대기 중 입자상 물질 분석 (Single Particle Analysis of Atmospheric Aerosol Particles Collected in Seoul, 2001, Using Low-Z Particle Electron Probe X-ray Microanalysis)

  • 구희준;김혜경;노철언
    • 한국대기환경학회지
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    • 제20권6호
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    • pp.823-832
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    • 2004
  • Atmospheric aerosol particles collected in Seoul on four single days, each in every seasons of 2001, were characterized and classified on the basis of their chemical species using low-Z particle electron probe X-ray microanalysis (low-Z particle EPMA). Low-Z particle EPMA technique can analyze both the size and the chemical species of individual aerosol particles of micrometer size and provide detailed information on the size distribution of each chemical species. The major chemical species observed in Seoul aerosol were aluminosilicate, silicon dioxide, calcium carbonate, organic, carbon-rich, marine originated, and ammonium sulfate particles, etc. The soil originated species, such as aluminosilicate, silicon dioxide, and calcium carbonate were the most popular in the coarse fraction, meanwhile, carbonaceous and ammonium sulfate were the dominant species found in the fine fraction. Marine originated species such as sodium nitrate was frequently encountered, up to 30% of the analyzed aerosol particles.