• 제목/요약/키워드: Mie Density

검색결과 35건 처리시간 0.029초

유해성 적조생물, Cochlodinium polykrikoides Margalef (Dinophyceae) 성장에 영향을 미치는 광량과 파장 (Effects of Light Quantity and Quality on the Growth of the HarmfulDinoflagellate, Cochlodinium polykrikoides Margalef (Dinophyceae))

  • 오석진;윤양호;김대일
    • ALGAE
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    • 제21권3호
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    • pp.311-316
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    • 2006
  • The effects of light quality and irradiance on the growth of Cochlodinium polykrikoides were investigated in the laboratory. At 25°C and 30 psu the irradiance-growth curve was described as μ = 0.34 (I-9.76)/(I+12.5), (r=0.98). This suggests half-saturation photon flux density (PFD) (Ks) of 32.0 μmol photons m–2 s–1, and a compensation PFD (Ic) of 9.76 μmol photons m–2 s–1. Because the Ic equates to a depth of ca. 15.4 m, these responses suggest that irradiance at the depth around and below the thermocline in Yeosuhae Bay would provide favorable conditions for C. polykrikoides. Photoinhibition did not occur at 300 μmol photons m–2 s–1, which was the maximum irradiance used in this study. Blue (450 nm), yellow (590 nm) and red (650 nm) light had different effects on the growth of C. polykrikoides: it grew well under blue light, but not under yellow light. This implies that C. polykrikoides is more likely to cause an outbreak of red tide in the open sea where blue-green wavelengths predominate, rather than in enclosed water bodies where suspended particles absorb most of the blue wavelengths, and yellow-orange wavelengths predominate.

Agronomic features and yield components of sago palms grown in the islands in Southeast Asia and Melanesia

  • Ehara, Hiroshi;Naito, Hitoshi;Mishima, Takashi;Toyoda, Yukio;Mizota, Chitoshi;Susanto, Slamet;Bintoro, M.H.;Pasolon, Yulius B.;Abbas, Barahima;Suwignyo, Rujito A.;Munandar, Munandar
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2017년도 9th Asian Crop Science Association conference
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    • pp.360-360
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    • 2017
  • Morphological characteristics indicating agronomic features and yield components (trunk length, trunk diameter, thickness of bark, pith density, dry-matter percentage of pith and starch concentration in pith) of sago palms (Metroxylon sagu Rottbøll) were compared between the 27 populations grown in the islands in Southeast Asia (West Sumatra, South Sumatra, West Java, Southeast Sulawesi, Ternate, Halmahera and Seram in Indonesia) and the 20 populations grown in Melanesia (West Papua in Indonesia, East Sepik and New Ireland island in Papua New Guinea). The average starch yield calculated based on the yield components was $310kg\;plant^{-1}$ and $244kg\;plant^{-1}$ in the islands in Southeast and Melanesia, respectively. The variation of starch yield in Melanesia (CV: about 80%) was larger than that in the islands in Southeast Asia (CV: about 60%). The difference in starch yield in the islands in Southeast Asia was mainly attributed to the trunk diameter breast height and the dry-matter percentage of pith. In contrast, the differences in trunk length and dry-matter percentage of pith mainly accounted for the difference in starch yield in Melanesia. The sago palms in the islands in Southeast Asia had a comparatively thick and short trunk and those in Melanesia had a comparatively thinner and longer trunk. However, the average pith dry-matter yield was almost same level as $400kg\;plant^{-1}$ in both the islands in Southeast Asia and Melanesia. The difference in starch yield between the two areas was attributed to the difference in starch concentration in pith, 77% and 58% in the islands in Southeast Asia and Melanesia, respectively.

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High-k ZrO2 Enhanced Localized Surface Plasmon Resonance for Application to Thin Film Silicon Solar Cells

  • Li, Hua-Min;Zang, Gang;Yang, Cheng;Lim, Yeong-Dae;Shen, Tian-Zi;Yoo, Won-Jong;Park, Young-Jun;Lim, Jong-Min
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2009년도 제38회 동계학술대회 초록집
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    • pp.276-276
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    • 2010
  • Localized surface plasmon resonance (LSPR) has been explored recently as a promising approach to increase energy conversion efficiency in photovoltaic devices, particularly for thin film hydrogenated amorphous silicon (a-Si:H) solar cells. The LSPR is frequently excited via an electromagnetic (EM) radiation in proximate metallic nanostructures and its primary con sequences are selective photon extinction and local EM enhancement which gives rise to improved photogeneration of electron-hole (e-h) pairs, and consequently increases photocurrent. In this work, high-dielectric-constant (k) $ZrO_2$ (refractive index n=2.22, dielectric constant $\varepsilon=4.93$ at the wavelength of 550 nm) is proposed as spacing layer to enhance the LSPR for application to the thin film silicon solar cells. Compared to excitation of the LSPR using $SiO_2$ (n=1.46, $\varepsilon=2.13$ at the wavelength of 546.1 nm) spacing layer with Au nanoparticles of the radius of 45nm, that using $ZrO_2$ dielectric shows the advantages of(i) ~2.5 times greater polarizability, (ii) ~3.5 times larger scattering cross-section and ~1.5 times larger absorption cross-section, (iii) 4.5% higher transmission coefficient of the same thickness and (iv) 7.8% greater transmitted electric filed intensity at the same depth. All those results are calculated by Mie theory and Fresnel equations, and simulated by finite-difference time-domain (FDTD) calculations with proper boundary conditions. Red-shifting of the LSPR wavelength using high-k $ZrO_2$ dielectric is also observed according to location of the peak and this is consistent with the other's report. Finally, our experimental results show that variation of short-circuit current density ($J_{sc}$) of the LSPR enhanced a-Si:H solar cell by using the $ZrO_2$ spacing layer is 45.4% higher than that using the $SiO_2$ spacing layer, supporting our calculation and theory.

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Chemistry of mist deposition of organic polymer PEDOT:PSS on crystalline Si

  • Shirai, Hajime;Ohki, Tatsuya;Liu, Qiming;Ichikawa, Koki
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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    • pp.388-388
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    • 2016
  • Chemical mist deposition (CMD) of poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) was investigated with cavitation frequency f, solvent, flow rate of nitrogen, substrate temperature $T_s$, and substrate dc bias $V_s$ as variables for efficient PEDOT:PSS/crystalline (c-)Si heterojunction solar cells (Fig. 1). The high-speed camera and differential mobility analysis characterizations revealed that average size and flux of PEDOT:PSS mist depend on f, solvent, and $V_s$. The size distribution of mist particles including EG/DI water cosolvent is also shown at three different $V_s$ of 0, 1.5, and 5 kV for a f of 3 MHz (Fig. 2). The size distribution of EG/DI water mist without PEDOT:PSS is also shown at the bottom. A peak maximum shifted from 300-350 to 20-30 nm with a narrow band width of ~150 nm for PEDOT:PSS solution, whose maximum number density increased significantly up to 8000/cc with increasing $V_s$. On the other hand, for EG/water cosolvent mist alone, the peak maximum was observed at a 72.3 nm with a number density of ~700/cc and a band width of ~160 nm and it decreased markedly with increasing $V_s$. These findings were not observed for PEDOT:PSS/EG/DI water mist. In addition, the Mie scattering image of PEDOT:PSS mist under white bias light was not observed at $V_s$ above 5 kV, because the average size of mist became smaller. These results imply that most of solvent is solvated in PEDOT:PSS molecule and/or solvent is vaporized. Thus, higher f and $V_s$ generate preferentially fine mist particle with a narrower band width. Film deposition occurred when $V_s$ was impressed on positive to a c-Si substrate at a Ts of $30-40^{\circ}C$, whereas no deposition of films occurred on negative, implying that negatively charged mist mainly provide the film deposition. The uniform deposition of PEDOT:PSS films occurred on textured c-Si(100) substrate by adjusting $T_s$ and $V_s$. The adhesion of CMD PEDOT:PSS to c-Si enhanced by $V_s$ conspicuously compared to that of spin-coated film. The CMD PEDOT:PSS/c-Si solar cell devices on textured c-Si(100) exhibited a ${\eta}$ of 11.0% with the better uniformity of the solar cell parameters. Furthermore, ${\eta}$ increased to 12.5% with a $J_{sc}$ of $35.6mA/cm^2$, a $V_{oc}$ of 0.53 V, and a FF of 0.67 with an antireflection (AR) coating layer of 20-nm-thick CMD molybdenum oxide $MoO_x$ (n= 2.1) using negatively charged mist of 0.1 wt% 12 Molybdo (VI) phosphoric acid n-Hydrate) $H_3(PMo_{12}O_40){\cdot}nH_2O$ in methanol. CMD. These findings suggest that the CMD with negatively charged mist has a great potential for the uniform deposition of organic and inorganic on textured c-Si substrate by adjusting $T_s$ and $V_s$.

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임신성 당뇨병 환자의 식습관 및 식이섭취에 관한 환자-대조군 연구 (A Case-Control Study of Food Habits and Diet Intakes of Women with Gestational Diabetes Mellitus)

  • 지선경;장학철;최혜미
    • Journal of Nutrition and Health
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    • 제41권1호
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    • pp.41-53
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    • 2008
  • 임신성 당뇨병의 발병에 영향을 미치는 식이 인자를 알아보고자 컴퓨터용 식품섭취 빈도조사지와 설문지 등을 이용하여 임신성 당뇨병의 환자군-대조군 연구를 시행한 결과는 다음과 같다. 임신성 당뇨병군이 대조군보다 연령과 BMI가 높았고, 당뇨병의 가족력이 많았다. 임신전의 식습관은 임신성 당뇨병군이 대조군보다 1일 식사횟수가 적었고, 식사시간이 불규칙하고 식사속도가 빨랐으며 채식을 적게 하고 기름진 음식을 싫어하는 경향이었으며, 식습관점수가 낮았다. 식품섭취빈도법으로 조사한 영양소 섭취량에서는 임신성당뇨병군이 대조군보다 탄수화물의 섭취량이 유의적으로 많았고 단백질의 에너지 섭취비율이 유의적으로 낮았다. 지방의 섭취량에는 두 군간에 차이가 없었으며 임신성 당뇨병군이 대조군보다 단백질과 칼슘, 인, 비타민 B,의 영양밀도가 유의적으로 낮았다. 두 그룹간에 섭취량에 유의적 차이를 보이는 식품 중 쌀, 중국국수, 돼지고기 등은 임신성 당뇨병군에서 대조군보다 많이 섭취하였고, 옥수수, 오징어채, 큰멸치, 수박, 포도, 복숭아, 밤, 땅콩, 호상 요구르트, 치즈, 검정콩, 당근 등은 대조군에서 섭취량이나 섭취빈도가 많았다. 두 군 사이에 섭취량에 유의적 차이를 보이는 음식 중 온면, 시루떡, 햄버거, 돼지고기편육, 삶은 계란 등은 임신성 당뇨병군에서 섭취량이 많았고, 전병, 두부조림, 오징어채무침, 깍두기, 야채샐러드, 김치국, 과일샐러드, 콩밥, 콩조림, 토마토쥬스 등은 대조군에서 섭취량이나 섭취빈도가 많았다. 특히 쌀의 경우에는 임신성 당뇨병군이 대조군보다 섭취량은 많았으나 섭취빈도는 적어 임신성 당뇨병군에서 1회의 섭취분량이 많았던 것으로 생각할 수 있다. 영양소 중에서는 탄수화물이나 에너지의 섭취량이 많을 때 임신성 당뇨병의 odds ratio가 증가하였고, 식품이나 음식은 쌀, 국수, 돼지고기, 온면, 시루떡, 햄버거, 삶은 계란, 돼지고기편육 등의 섭취량이 많을 때 임신성 당뇨병의 odds ratio가 증가하였다. 상관관계의 분석결과 에너지 섭취량, 탄수화물 섭취량 등이 혈액의 포도당농도와 상관관계가 있는 것으로 나타났다. 이상으로 본 연구 결과를 종합해 볼 때 임신성 당뇨병에 영향을 미치는 식이 인자는 지방보다는 탄수화물의 섭취량으로 생각되어지며 단백질을 포함한 식사의 질과 바람직하지 않은 식습관이 영향을 미칠 수 있음을 생각해 볼 수 있다.