• 한국광학회지
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• 제25권6호
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• pp.315-325
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• 2014

어류를 잡기 위한 기존의 여러 방법 중 하나로, 한국과 일본에서는 광원을 이용해 오징어를 잡는 방법이 주로 행하여져 왔다. 사용된 광원으로는 메탈할라이드를 이용한 방법이 주로 이용되었으나 유가 상승으로 인한 유지비용 상승이 문제로 대두되어져 왔다. 또한 메탈할라이드 광원은 고온으로 인한 화상의 위험과 인체에 유해한 자외선 스펙트럼 방출로 인하여 어업인의 건강을 위협하여 왔다. 이에 반해 엘이디 광원은 저전력, 저발열의 장점을 가지고 있어서 메탈할라이드 광원을 대체하는 연구가 주로 한국과 일본에서 이루어져 왔으나, 메탈할라이드 광원 대비 낮은 광량과 다른 배광특성으로 인해 어획량은 메탈할라이드 집어등 어선 대비 저조한 실정이다. 이러한 문제점을 해결하고자 본 논문에서는 기존의 메탈할라이드 집어등 어선과 가장 유사한 조도 분포를 얻기 위해 메탈할라이드 광원과 엘이디 광원을 조합 배치하였고, 그때의 수심별 조도 분포 시뮬레이션을 하여 최적의 배치조건을 제시하였다.

• Journal of the Optical Society of Korea
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• 제20권5호
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• pp.547-556
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• 2016

A fishing lamp is the instrument for attracting distributed fish to a certain place, and is the lighting system mainly used in fishery. In the inshore fishing, most fishing lamps are used for squid and hairtail jigging fishing, and the light source of the fishing lamps mainly used is metal halide with 1.5 KW in electric power consumption. We will analyze the irradiance distribution according to depth because squid is attracted towards light. To analyze irradiance distribution by such fishing lamps, data for seawater Type-II among the seawater types defined in 1976 are applied to East Sea. However, the Type-II data have limitations in analyzing precise seawater transmission characteristics, due to insufficient information on deep seawater. This paper analyzed the irradiance distribution of fishing lamps using the measurement of transmission characteristics in the seawater in East Sea up to 100 m underwater instead of Type-II data, which is not sufficient for transmission. A compensation factor was drawn between the actual measurement data and Type-II data through seawater transmission characteristics simulation.

• Journal of Microbiology and Biotechnology
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• 제27권11호
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• pp.2010-2018
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• 2017

Mixotrophic microalgal growth gives a great premise for wastewater treatment based on photoautotrophic nutrient utilization and heterotrophic organic removal while producing renewable biomass. There remains a need for a control strategy to enrich them in a photobioreactor. This study performed a series of batch experiments using a mixotroph, Chlorella sorokiniana, to characterize optimal guidelines of mixotrophic growth based on a statistical design of the experiment. Using a central composite design, this study evaluated how temperature and light irradiance are associated with $CO_2$ capture and organic carbon respiration through biomass production and ammonia removal kinetics. By conducting regressions on the experimental data, response surfaces were created to suggest proper ranges of temperature and light irradiance that mixotrophs can beneficially use as two types of energy sources. The results identified that efficient mixotrophic metabolism of Chlorella sorokiniana for organics and inorganics occurs at the temperature of $30-40^{\circ}C$ and diurnal light condition of $150-200{\mu}mol\;E{\cdot}m^{-2}{\cdot}s^{-1}$. The optimal specific growth rate and ammonia removal rate were recorded as 0.51/d and 0.56/h on average, respectively, and the confirmation test verified that the organic removal rate was $105mg\;COD{\cdot}l^{-1}{\cdot}d^{-1}$. These results support the development of a viable option for sustainable treatment and effluent quality management of problematic livestock wastewater.

• 한국수산과학회지
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• 제43권6호
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• pp.715-722
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• 2010

The effects of temperature, salinity and irradiance on the growth of the harmful red tide dinoflagellate Cochlodinium polykrikoides Margelef isolated from the South Sea of Korea were examined in the laboratory. Growth was examined under the following combinations of temperature and salinity: 15, 20, 25 and $30^{\circ}C$, and 15, 20, 25, 30 and 35 psu at a constant irradiance of $180\;{\mu}mol/m^2/s$. No growth was observed with a temperature of $15^{\circ}C$ and a salinitiy of 15 psu. Moderate growth rates of more than 0.30 /day were obtained at $25^{\circ}C$ with salinities of 25.35 psu. These values are similar to in situ observations for this species. The maximum growth rate, 0.35 /day, was obtained at $25^{\circ}C$ and 30 psu. In light experiments, cell growth of C. polykrikoides was conducted with constant temperature ($20^{\circ}C$) and salinity (30 psu) under light photon flux densities (PFD) of 10, 25, 50, 70, 100, 150, 250 and $350\;{\mu}mol/m^2/s$. C. polykrikoides did not grow at $10\;{\mu}mol/m^2/s$. Cell growth was observed at irradiance values of $25\;{\mu}mol/m^2/s$ and above. The irradiance-growth curve was described as ${\mu}=0.30{\cdot}(I-15.27)/(I+27.22)$, (r=0.99). This suggests a compensation PFD of $15.27\;{\mu}mol/m^2/s$ and a maximum growth rate of 0.30 /day. In conclusion, C. polykrikoides prefers high salinity, temperature and irradiance in summer in Korea. These results provide important information for understanding the mechanism of C. polykrikoides blooms and developing technology to predict blooms of this organism in the field.

• 대기
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• 제21권2호
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• pp.131-142
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• 2011

Spectral solar irradiances were observed using a visible and UV Multi-Filter Rotating Shadowband Radiometer on the rooftop of the Science Building at Yonsei University, Seoul ($37.57^{\circ}N$, $126.98^{\circ}E$, 86 m) during one year period in 2006. 1-min measurements of global(total) and diffuse solar irradiances over the solar zenith angle (SZA) ranges from $20^{\circ}$ to $70^{\circ}$ were used to examine the effects of clouds and total optical depth (TOD) on enhancing four solar irradiance components (broadband 395-955 nm, UV channel 304.5 nm, visible channel 495.2 nm, and infrared channel 869.2 nm) together with the sky camera images for the assessment of cloud conditions at the time of each measurement. The obtained clear-sky irradiance measurements were used for empirical model of clear-sky irradiance with the cosine of the solar zenith angle (SZA) as an independent variable. These developed models produce continuous estimates of global and diffuse solar irradiances for clear sky. Then, the clear-sky irradiances are used to estimate the effects of clouds and TOD on the enhancement of surface solar irradiance as a difference between the measured and the estimated clear-sky values. It was found that the enhancements occur at TODs less than 1.0 (i.e. transmissivity greater than 37%) when solar disk was not obscured or obscured by optically thin clouds. Although the TOD is less than 1.0, the probability of the occurrence for the enhancements shows 50~65% depending on four different solar radiation components with the low UV irradiance. The cumulus types such as stratoculmus and altoculumus were found to produce localized enhancement of broadband global solar irradiance of up to 36.0% at TOD of 0.43 under overcast skies (cloud cover 90%) when direct solar beam was unobstructed through the broken clouds. However, those same type clouds were found to attenuate up to 80% of the incoming global solar irradiance at TOD of about 7.0. The maximum global UV enhancement was only 3.8% which is much lower than those of other three solar components because of the light scattering efficiency of cloud drops. It was shown that the most of the enhancements occurred under cloud cover from 40 to 90%. The broadband global enhancement greater than 20% occurred for SZAs ranging from 28 to $62^{\circ}$. The broadband diffuse irradiance has been increased up to 467.8% (TOD 0.34) by clouds. In the case of channel 869.0 nm, the maximum diffuse enhancement was 609.5%. Thus, it is required to measure irradiance for various cloud conditions in order to obtain climatological values, to trace the differences among cloud types, and to eventually estimate the influence on solar irradiance by cloud characteristics.

• 원예과학기술지
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• 제19권4호
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• pp.555-559
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• 2001

본 연구는 유도일장과 강광도 조건에서 화아발달 시기에 간이 엽록소 측정기(SPAD-502 chlorophyll meter)를 이용한 국화잎의 위치별 엽록소 함량변화를 조사하기 위하여 실시하였다. SPAD 값은 수확기에 줄기의 최상부에서부터 매 3엽씩 하부로 내려가면서 서로 다른 일장과 광도조건에서 측정하였다. 10시간의 단일에서 SPAD 값이 가장 높았고, 뒤를 이어 13시간과 16기간 일장 순이었다. 특히 단일조건에서는 화아의 아래로부터 첫 번째인 가장 어린잎에서 가장 높았으며, 줄기의 하부로 내려갈수록 감소하였다. 장일조건에서는 줄기의 상부에서 15-27번째의 잎이 가장 높은 SPAD 값을 나타내었고, 줄기 최상단의 어린잎에서는 최소값을 기록하였다. 이러한 결과는 단일 조건에서는 상부의 잎들이 발달하는 꽃들을 지지하기 위한 중요한 소스(source)가 되는 반면, 영양생장기의 국화는 상부에서 분화 또는 발달하는 어린잎이 여전히 중요한 싱크(sink)의 하나로서 역할하고 있는 것으로 판단된다. SPAD 값은 강광도 조건에서 증가하였고, 광도가 낮아짐에 따라 감소하였다.

• 한국수산과학회지
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• 제44권1호
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• pp.64-70
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• 2011

Nitrate reductase (NR) is activated by nitrogen sources (${NO_3}^-$ and ${NH_4}^+$) and irradiance. This study investigated the effects of these factors on the NR activity of Ulva pertusa (Chlorophyta) and Ecklonia cava (Phaeophyta). In addition, the ammonium (${NH_4}^+$) and nitrate (${NO_3}^-$) uptake rates of the two species were examined. U. pertusa took up most of the ${NO_3}^-$ and ${NH_4}^+$ in the medium during a 3hour incubation, while E. cava had a relatively high uptake rate after 3 hours. The NR activities of the two species were affected by the nitrogen source and irradiance and were highest when they were exposed to ${NO_3}^-$-rich medium and high irradiance. However, the patterns of NR activity differed between the two species. In ${NO_3}^-$-rich medium and high irradiance, U. pertusa achieved the highest NR activity ($2.01{\pm}0.07\;{\mu}mol$ ${NO_2}^-$ $g^{-1}$ DW $h^{-1}$) within the first 3 hours and then this activity decreased drastically. By contrast, the NR activity of E. cava ($0.36{\pm}0.04\;{\mu}mol$ ${NO_2}^-$ $g^{-1}$ DW $h^{-1}$) was constant for 12 hours. When exposed to darkness, the NR activity of U. pertusa decreased dramatically, while that of E. cava increased gradually for 12 hours. Therefore, E. cava is able to maintain NR activity during the dark because of its adequate carbohydrate reserves and substrate.

• Journal of Applied Biological Chemistry
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• 제43권4호
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• pp.192-196
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• 2000

The molecular basis of plant adaptation to the environment is one of the most complex areas of plant science and an understanding of this subject is critical to our ability to feed an increasing word population. Research on plant adaptation to the environment often involves two complementary approaches; top-down studies of well-adapted plants with the goal of identifying and describing the biochemical basis of adaptation and bottom-up targeted analysis of specific biochemical mechanisms with the goal of understanding how these mechanisms contribute to overall plant performance. This brief review will provide examples of both of these approaches by describing the study of sorghum's adaptation to dry environments and the role of a blue light responsive chloroplast promoter that helps protect plants against damage by high irradiance.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 하계학술대회 논문집 Vol.9
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• pp.16-17
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• 2008

Recently, characteristic research by the changes in the spectrum, one of the factors that influence analysis of maximum output power of PV module, has been studied. In this paper, a one-day intensity of solar irradiation, change of spectrums with time and electrical output for spectrums are analyzed. As a result, blue-rich wavelength compared with red-rich wavelength has large variation of solar irradiance with time. It is recognized that change of solar irradiance is predominately on variation of blue-rich wavelength. Also in same intensity of solar irradiance, electrical output in blue-rich wavelength was 4-8[%] higher compared to in red-rich wavelength.

• 수산해양기술연구
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• 제37권2호
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• pp.117-123
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• 2001

멸치초망어업에서는 반사갓에 AC 100V, 1kW 백열등 1개를 끼워서 집어등으로 사용하고 있다. 집어등은 저층에 있는 어군을 표층까지 부상시키고, 또한 표층에 유집된 어군을 자루그물로 유도하는 역할을 수행하고 있다. 본 연구에서는 멸치군을 유효하게 집어, 유도할 수 있는 집어 등을 구명하기 위한 기초연구로서 현재 초망어업에서 사용되고 있는 반사갓의 방사효율과 1kW 백열등의 파장별 방사특성을 계측하였으며, 그 결과를 요약하면 다음과 같다. 1. 반사갓은 백열등의 방사효율을 1.8배 정도 증가시켰으며, 전구를 중심으로 원형에 가깝게 빛을 수중으로 방사시켰고, 이는 수중광도계로 측정한 방사조도와도 잘 일치하였다. 2. 공기중에서 백열등의 방사조도는 994nm의 파장에서 최대치를 보인 반면 심도 0.5m, 1.0m 층에서 최대치를 보인 반면 심도 0.5m, 1.0m층에서는 모두 690nm의 파장에서 최대치를 보였다. 3. 집어등의 연직 하방에 있어서 심도(x)과 수중조도(y)와의 관계식은 다음과 같다. y=146.03e 상(-0.37x) 4. 1kW 백열등의 빛은 정횡방향보다 연직방향쪽으로 많이 투과되었으며, 집어등 직하에서의 빛은 심도 20m이심에는 도달하지 않는다고 추정된다.