• 생물환경조절학회지
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• 제16권4호
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• pp.314-321
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• 2007

도시농업에 대한 관심과 수요가 증가하고 있으나 실내 채소재배에 대한 연구는 매우 미진한 상황이다. 따라서 본 연구는 아파트 베란다에서 이용하기에 좋은 관비방법 및 재배가 적합한 채소작목을 선발하고자 수행되었다. 가정용 채소 관비방법을 선발하기 위하여 담액수경, 심지관수(양액 또는 완효성비료), 두상관수 등 4가지 방법을 비교해 본 결과 심지관수법에서 상추, 겨자채, 적근대 모두 관행대비 생육과 수량이 높았다. 뿐만 아니라 심지관수 방법은 양수분관리에 필요한 노력과 시간을 대폭 줄일 수 있고 (주)애그로액티브와 공동 개발한 완효성비료를 이용하면 별도의 양분관리 없이 채소를 생산할 수 있다. 한편, 물이 바닥으로 흘러 나오지 않기 때문에 실내에서 사용도 가능하다. 한편, 가을의 베란다 환경을 조사한 결과 온 습도 환경은 채소 재배에 적절하였으나 광환경은 최고 광량이 남향 베란다에서는 온실의 48%, 남동향 베란다에서는 35%에 불과하여 생육에 가장 큰 제한요인으로 나타났다. 따라서 베란다의 약광 조건에서도 생육이 우수한 작물을 선발하고자 0%, 50%, 70%, 90% 차광조건에서 로메인상추, 청치마상추, 생채, 엔다이브, 청경채, 겨자채, 쑥갓, 적근대, 부추 등 9종의 엽채류를 재배하였다. 부추가 광이 부족한 환경에서도 가장 생육이 우수하였고 엔다이브도 약광에서 생육이 좋았으며 상추, 쑥갓, 청경채가 뒤를 이었다. 이 연구결과를 토대로 각 베란다의 방향이나 위치, 계절에 따라 달라지는 광환경에 적합한 채소작물 선발에 도움이 될 것으로 생각된다.

• 한국해양바이오학회지
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• 제6권1호
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• pp.31-40
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• 2014

The production of astaxanthin in the microalga Haematococcus pluvialis has been investigated using a sequential methodology based on the application of two types of statistical designs. The employed preliminary experiment was a fractional factorial design $2^6$ in which the factors studied were: excessive irradiance and nitrate starvation, phosphate deficiency, acetate supplementation, salt stress, and elevated temperature. The experimental results indicate that the amount of astaxanthin accumulation in the cells can be enhanced by excessive irradiance and nitrate starvation whereas the other factors tested did not yield any enhancement. In the subsequent experiment, a central composite design was applied with four variables, light intensity, nitrate, phosphate, and acetate, at five levels each. The optimal conditions for the highest astaxanthin production were found to be $1040{\mu}E/(m^2{\cdot}s)$ light intensity, 0.04 g/L nitrate, 0.31 g/L phosphate, 0.05 g/L acetate concentration.

• 한국화재소방학회논문지
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• 제19권2호
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• pp.105-110
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• 2005

외부 복사열원(10, 15, 20, 25 및 $35kW/m^2$)에 노출된 난연처리된 목재의 탄화특성을 측정하기 위해 Douglas fir를 사용하였으며, 목재에 복사열원을 노출시키기 위해 Cone heater를 사용하였다. 시료의 크기는 $100mm\times100mm\times50m$로 Monoammonium phosphate, Sodium borate, Zinc borate를 이용하여 배합된 수용성 난연제에 의해 함침 처리된 목재(F2와 F4)와 비처리된 목재(N)를 사용하였다. 연구결과, 난연처리된 Douglas fir의 경우 비처리된 목재에 비해 탄화율이 외부 복사열원의 증가와 관계없이 현저히 낮음을 알 수 있었으며, 난연제의 함량 증가에 따라 탄화율이 낮게 나타났다. 비처리된 목재에 있어 연소속도가 상대적으로 큼을 알 수 있으며, 낮은 외부 복사열원에서 보다 높은 복사열원에서 그 차이가 많이 남을 알 수 있다. 또한, 외부 복사열원이 $35kW/m^2$일 때 평균 탄화속도는 비처리된 목재가 난연처리된 목재에 비해 약 2배정도 빠름을 알 수 있었다 탄화율, 연소속도 및 탄화깊이와 속도의 측정결과 본 연구에서 배합된 난연성 수용액은 탄화층에 의한 단열 효과 및 불꽃 억제 효과가 있음을 알 수 있었다.

• Ocean and Polar Research
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• 제25권4호
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• pp.427-435
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• 2003

Growth and pigment responses to different levels of solar radiation with or without ultraviolet (UV)-B component $({\lambda}=280-315nm)$ were investigated in Antarctic rhodophytes, Kallymenia antarctica and Palmaria decipiens, collected around King George Island during the summer of 2000. In K. antarctica specific growth rate, based on thallus area or fresh weight, decreased with increasing solar irradiances while P. decipiens were relatively insensitive to the effects of light. It is noticeable that the presence or absence of UV-B had no significant effect on growth for either species. However, K. antarctica showed a more pronounced reduction in chlorophyll (Chl a) concentrations at higher irradiances in the presence of UV-B. In P. decipiens, Chl a concentrations did not differ despite radiation level fluctuations being lower albeit than initial measurements. Thallus thickness was greater in K. antarctica than in P. decipiens. There were higher relative amounts of UV-absorbing pigments (UVAPs) in P. decipiens than in K, antarctica. The single absorbance peak obtained from the methanol extracts was resolved into three (316,332 and 346nm) in K. antarctica and four peaks (315,326,333 and 349 nm) in Palmaria as a result of the fourth-derivative. After 7 days exposure to solar radiation, the amount of UVAPs in K. antarctica was significantly reduced to a similar degree at all light levels, whereas that of P. decipiens remained unchanged except at 5% of surface irradiance. High performance liquid chromatography (HPLC) analysis of purified extracts indicated that P. decipiens possesses porphyra-334 in addition to three other mycosporine-like anlino acids (MAAs; asterina-330, palythine, shinorine), which are commonly present in K. antarctica. Significantly lower tolerance of K. antarctica to high levels of solar radiation may be connected with its usual absence in the eulittoral, while the active growth and elastic pigment responses of P. decipiens over a wide range of solar irradiance levels up to full sunlight seems to correspond well with its wide vertical distribution from rock pools down to 25-30m.

• 한국수산과학회지
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• 제44권3호
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• pp.290-297
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• 2011

The phenology of Campylaephora hypnaeoides J. Agardh and optimal conditions for carpospore release, growth and reproduction were examined in the field and in the laboratory from January to December 2007. In the field population of C. hypnaeoides, approximately 50% of the plants were vegetative during the study period. Additionally, the percentages of carposporophytes and tetrasporophytes were maximal in April (37%) and June (57%), respectively. Maximum growth in plant length, dry weight, and hook number coincided with the tetrasporophyte reproductive peak in the field. In culture, carpospore release, sporeling growth and reproduction were affected by environmental factors such as daylength, temperature, and salinity. The liberation of carpospores was maximum under continuous light and at a combination of $15^{\circ}C$ and $10\;{\mu}mol$ photons $m^{-2}\;s^{-1}$. Maximum growth of tetrasporophyte sporelings occurred at a combination of $20\;{\mu}mol$ photons $m^{-2}\;s^{-1}$ of constant light and $25^{\circ}C$. However, the growth of gametophyte sporelings was maximal under $40\;{\mu}mol$ photons $m^{-2}\;s^{-1}$ of constant light and in a combination of $20^{\circ}C$ and 35 psu. The tetrasporophyte sporelings were grew faster than gametophytes, indicating that gametophyte- and tetrasporophyte-sporelings have different physiological responses to irradiance and temperature. Tetrasporangial branches and cystocarps of C. hypnaeoides were produced from carpospores and tetraspores within 1 month, and they were stimulated at high temperature and irradiance levels. In conclusion, C. hypnaeoides should be seeded using carpospores during early winter (November-December) because cystocarps are easily identified by fishermen, and tetrasporophytes grow faster than gametophytes.

• ALGAE
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• 제23권3호
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• pp.241-250
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• 2008

Since seagrasses in the coastal and estuarine ecosystems achieve high levels of production, they require high inorganic carbon and nutrient incorporation. Thus, seagrasses may play a significant role in carbon and nutrient cycling in the coastal and estuarine ecosystems. To examine growth dynamics of Zostera marina L. environmental factors such as underwater irradiance, water temperature, and salinity, and biological parameters such as shoot density, biomass, shoot morphology, and leaf productivity were measured in two bay systems (Jindong Bay and Gamak Bay) on the southern coast of Korea. While underwater irradiance did not show distinct seasonal trend, water temperature at both sites exhibited clear seasonal trend throughout the experimental period. Shoot density increased dramatically during winter due to the increased seedlings through germination of seeds in Jindong Bay and due to the increased lateral shoots in Gamak Bay. Eelgrass biomass increased during winter and decreased during summer. Maximum biomass in Jindong Bay and Gamak Bay was 250.2 and 232.3 g dry weight m–a2, respectively. Carbon incorporation into the eelgrass leaf tissues was estimated from productivity and leaf tissues carbon content. The calculated annual carbon incorporations at the Jindong Bay and Gamak Bay sites were 163 and 295 g C m–`2 y–`1, respectively. This high carbon incorporation into seagrass tissues suggests that seagrass habitats play an important role as a carbon absorber in the coastal and estuarine ecosystems.

• ALGAE
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• 제35권2호
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• pp.123-131
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• 2020

Sargassum macrocarpum is a rich source of anti-inflammatory compounds. Recently, one of the compounds, tuberatolide B, has been reported as a functional anti-inflammatory additive for foods and nutraceuticals. The artificial seeding, growth and maturation of S. macrocarpum were investigated from May 2018 to September 2019. Indoor culture experiments for induction of egg release were conducted at temperatures of 17, 20, 23, and 26℃ and irradiances of 0, 10, 20, 40, and 80 μmol photons m^-2 s^-1 under 14 : 10 h (L : D) photoperiod. Within a given treatment combination, higher temperatures and irradiance levels favoured the maturation of receptacles in S. macrocarpum. Using artificial temperature and irradiance control, thalli matured one month earlier than thalli in nature. Under natural condition, receptacle formation began in April, and the eggs were released in June and July. The release of eggs from the receptacles was promoted at 17-20℃ and 40-80 μmol photons m^-2 s^-1, and the fastest growth of germlings occuring at 15-17℃ and 40 μmol photons m^-2 s^-1. For mature thalli, 300 g wet-weight was sufficient to seed 100 m of seed string. Thalli grew to 10.5 ± 2.6 cm in length at a density of 6.7 ± 3.3 individuals m^-1 after 1 year of cultivation, from germination. This study demonstrates that it is possible to cultivate S. macrocarpum for the production of anti-inflammatory products.

• Molecular & Cellular Toxicology
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• 제4권4호
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• pp.300-306
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• 2008

We investigated high light-induced alterations in antioxidant enzymes by exposing green vegetative cells of the alga Haematococcus pluvialis to excess irradiance to induce the production of astaxanthin, a carotenoid pigment. Total activity of catalase decreased approximately 70% after high light exposure, whereas glutathione peroxidase (GPX) activity was slightly enhanced. Total activity of superoxide dismutase and ascorbate peroxidase (APX) also slightly decreased. Overall, we did not observe dramatically elevated levels of antioxidant isozymes, although APXn, GPX2, and GPX3 isozyme increased slightly. ${H_2}{O_2}$ content increased about sixfold after high light exposure, demonstrating severe cellular oxidative stress, whereas lipid peroxidation was notably reduced. Concomitantly, astaxanthin accumulation increased about sevenfold. This result suggests that probably massively accumulated astaxanthin may be one of the antioxidant protector against high light stress.

• Journal of the Optical Society of Korea
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• 제12권2호
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• pp.88-92
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• 2008

This paper discusses a photon-counting linear discriminant analysis (LDA) with computational integral imaging (II). The computational II method reconstructs three-dimensional (3D) objects on the reconstruction planes located at arbitrary depth-levels. A maximum likelihood estimation (MLE) can be used to estimate the Poisson parameters of photon counts in the reconstruction space. The photon-counting LDA combined with the computational II method is developed in order to classify partially occluded objects with photon-limited images. Unknown targets are classified with the estimated Poisson parameters while reconstructed irradiance images are trained. It is shown that a low number of photons are sufficient to classify occluded objects with the proposed method.

• 한국산업융합학회 논문집
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• 제22권4호
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• pp.395-403
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• 2019

The excessive need of power is creating an unbalance situation in power sector, where solar energy is one of the best solutions among other energy sources to mitigate this demand. It is globally accepted because of its flexibility and long life compared to others. A lot research is going on to enhance the energy efficiency by introducing photovoltaic (PV) power generation technology, but still irradiation of PV power is the major problem. In this manuscript, we have designed PV module using single diode methodology and also the solar conversion efficiency was boosted with maximum power point tracking (MPPT) by using perturb and observe (P&O) algorithm. The simulation was done for $1000W/m^2$ and $800W/m^2$ at solar irradiance in cell temperature of 25C and 40C degree levels in PSIM tool.