• Journal of Digital Convergence
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• v.11 no.4
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• pp.229-234
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• 2013

The purpose of this study is to develop a lighting apparatus of the illuminance and color temperature to maximize the ability of the optimal combination of light sources that can be controlled efficiently control device. Finding people comfortable feeling for indoor lighting that can be used in a variety of color temperature illumination area by combining light sensitivity can be realized. Lighting apparatus for fluorescent lamps with different color temperature of 2000K and 8000K, and by varying the quantity of each of the fluorescent lamps, the illuminance of lighting equipment and color temperature through optical simulations were evaluated. By infrared remote control receiver, divided into 5 types of relaxation, conversation, meeting, hospitality, arts and the lighting environment you want to transfer the PC0 ~ PC4 through the parallel port on the mode selected by the user at the receiving end the DC voltage output. EEFL inverter input DC voltage and the DC input voltage, depending on the level of EEFL dimming value (illuminance and color temperature) lighting environment you want to create change while using a PIR sensor EEFL automatically turn off if people do not have was developed so that the power consumption so you can save.

• Advances in environmental research
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• v.5 no.2
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• pp.125-140
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• 2016

The paper is focused on the economic analysis of two hydrometallurgical processes for recovery of yttrium and other rare earth elements (REEs) from fluorescent phosphors of spent lamps. The first process includes leaching with sulphuric acid and precipitation of a mixture of oxalates by oxalic acid, the second one includes leaching with sulphuric acid, solvent extraction with D2EHPA, stripping by acid and recovery of yttrium and traces of other rare earths (REs) by precipitation with oxalic acid. In both cases the REEs were recovered as oxides by calcination of the oxalate salts. The economic analysis was estimated considering the real capacity of the HydroWEEE mobile's plant ($420kg\;batch^{-1}$). For the first flow-sheet the cost of recycling comes to $4.0{\euro}kg^{-1}$, while the revenue from the end-product is around $5.40{\euro}kg^{-1}$. The second process is not profitable, as well as the first one, taking into account the composition of the final oxides: the cost of recycling comes to $5.2{\euro}kg^{-1}$, while the revenue from the end-product is around $3.56{\euro}kg^{-1}$. The process becomes profitable if the final RE oxide mixture is sold for nearly $50{\euro}kg^{-1}$, a value rather far from the current market prices but not so unlikely since could be achieved in the incoming years, considering the significant fluctuations of the Res' market.

• Horticultural Science & Technology
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• v.34 no.6
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• pp.840-844
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• 2016

Quinoa (Chenopodium quinoa Willd.) is a grain crop with high nutritional value. The leaves and sprouts of quinoa can also be consumed either raw or cooked, providing considerably nutritional value as well as high antioxidant and anticancer activities. This study was carried out to obtain basic data to assist in the practical design of a plant factory with artificial lighting for the cultivation of quinoa as a leafy vegetable. We estimated the energy content of the quinoa and the electrical energy required to produce this crop. The yield was 1,000 plants per day, with a planting density and light intensity of $0.015m^2$ ($15{\times}10cm$) and $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, respectively. The total number of plants, cultivation area, and electricity consumption were estimated to be 25,000, $375m^2$, and $93,750{\mu}mol{\cdot}s^{-1}$, respectively. White fluorescent lamps were used at a power of 20.4 kW from 1,857 fluorescent lamps (FL, 55 W), and the cost for electricity was approximately 1,820 dollars (exchange rate of $1 = 1,200 won) per month. For a daily harvest of 1,000 plants per day in a closed plant factory, the estimated light installation cost, total installation cost, and total production cost would be 15,473, 46,421, and 55,704 dollars, respectively. The calculated production cost per plant, including labor costs, would be 27 cents for the 25-day cultivation period, with a marketable ratio of 80%. Considering the annual total expenses, income, and depreciation costs, the selling price per plant was estimated to be approximately 56 cents.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.56 no.6
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• pp.878-888
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• 2023

Growth responses of Chlorella vulgaris exposed to different light intensities and wavelengths of light-emitting diodes (LEDs) were investigated. C. vulgaris was cultured under red LED (650 nm), blue LED (450 nm), green LED (520 nm), and fluorescent lamps (three wavelengths, control). The maximum growth rates (µ_max) of C. vulgaris were highest under the blue LED, followed by the red LED, green LED, and fluorescent lamps. The low compensation photon flux density (I₀) and low half-saturation constants (K_s) were observed in C. vulgaris cultured under the red LED, indicating that high C. vulgaris growth is closely related to the low light intensity of the red LED suggesting that the red LED can be useful for the biomass production of C. vulgaris. Furthermore, it was observed that under the blue LED during the stationary phase, there was an increase in useful bioactive substances, such as proteins and lipids, which are beneficial for biomass production. In conclusion, the red LED is an economical light source that can enhance cell density, and the blue LED is effective in promoting valuable intracellular substances.

• Journal of Bio-Environment Control
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• v.21 no.3
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• pp.220-227
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• 2012

This study was conducted to analyze the seeding quality of paprika and the growth and early yield after transplanting of paprika nursed under artificial light and natural light. In this study, blue LED, red LED, and white fluorescent lamps (FL) were used as artificial lighting sources. Photoperiod, average photosynthetic photon flux, air temperature, and relative humidity in a closed transplants production system (CTPS) were maintained at 16/8 h, $204{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, 26/$20^{\circ}C$, and 70%, respectively. Leaf length, leaf width, leaf area, top fresh weight and dry weight of paprika seedlings, and chlorophyll content in paprika leaves nursed under LED and fluorescent lamps for 21 days after experiment were significantly affected by light treatments. As compared with the control (white FL), leaf area of paprika grown under blue LED, red LED, and natural light was decreased by 63%, 63%, and 28%, respectively. Top dry weight of paprika grown under blue LED, red LED, and natural light was 64%, 50%, and 22%, respectively, compared with the control. Number of leaves on 18 days after transplanting showed with red LED, blue LED, and natural light by 86%, 84%, and 48%, respectively, compared with the control. On 114 days after transplanting, paprika nursed under blue LED and red LED had relatively short plant height. This result might be caused that the elongation of its internodes was suppressed by the illumination of sole blue or red light. Average number of fruits per plant harvested during 4 weeks after first harvest was 3.5 with red LED, 3.3 with blue LED, 1.0 with natural light, and 2.2 with control, respectively. Early yield of paprika nursed under red LED, blue LED, natural light, and control were 453 g/plant, 403 g/plant, 101 g/plant, and 273 g/plant, respectively. Larger fruit of 136 g was harvested with red LED treatment. Even though the early yield of paprika was greatly increased with artificial lighting, but total yield was almost similar as the harvest period after transplanting in greenhouses was lengthened. From the above results, we could understand that paprika nursed under white FL, blue LED, and red LED showed good growth after transplanting and was early harvested by a week as compared to the natural light. Therefore, the white FL, blue LED, and red LED as the artificial lighting sources in CTPS could be strategically used to enhance the seedling quality, to shorten the harvest time, and to increase the yield of paprika.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.6
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• pp.255-261
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• 2005

Recently, the RF inductive discharge or inductively coupled plasma continues to attract growing attention as an effective plasma source in many industrial applications, the best known of which are plasma processing and lighting technology. To the point of lighting sources, the ring-shaped electrodeless fluorescent lamps utilizing an inductively coupled plasma have been objects of interest and research during the last decades, mainly because of their potential for extremely long life, high lamp efficacies, rapid power switching response. In this paper, maxwell 3D finite element analysis program (Ansoft) was used to obtain electromagnetic properties associated with the coil and nearby structures. The electromagnetic emitting properties were presented by 3D simulation software operated at 250 kHz and some specific conditions. The electromagnetic field in the ferrite core was shown to be high and symmetric. An LS-100 luminance meter and a Darsa-2000 spectrum analyzer were used in the experiment. According to data on the lamp tested using high magnetic field ferrite, the optical and thermal wave fields were shown to be high around the ring-shaped electrodeless fluorescent lamp. The optical or light field was high at the center of the bulb rather than around the ferrite core. The light conditions of the bulb were assumed to be complex, depending on the condition of the filler gas, the volume of the bulb, and the frequency of the inverter. Our results have shown coupling between the gas plasma and the field of the light emitted to be nonlinear.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.3
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• pp.638-644
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• 2008

It is required small size electronic ballast to fullfill the design philosophy of miniaturizing in the application of slim lamps. However, the traditional magnetic ballasts operated at 50-60Hz have been suffered from noticeable flicker, high loss, large crest factor and heavy weight. In this study, in order to solve these problems, It was proposed for driving 35W Class fluorescent lamp in the new type of electronic ballast, which is composed of rectifier, active power factor corrector, series resonant half bridge inverter and piezoelectric transformer. A 35W class(T5 class) fluorescent lamp is driven to successful by the fabricated ballast with piezoelectric transformer. Experimental results, It is proposed to driving the lamp using a electronic ballast at operating frequency of $75{\sim}79kHz$ approximatively. It is operated after for 25 min that were obtained good results of the input power factor of 0.95 and efficiency of 86%, respectively.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.80-83
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• 2001

As a LCD monitor is larger and thinner, a Cold Cathode Fluorescent Lamp (CCFL) for backlight in LCD monitor gradually becomes longer and thinner. The backlight of a large LCD monitor, however, has a limitation in its brightness. In this study, a parallel multi-lamp is used in order to supply enough brightness. Though the CCFLs are made through a detail and equal manufacturing process, they don't have exactly the same features individually in their brightness, frequency, voltage and current. Consequently, it is difficult to have equal brightness at an early lighting condition or during lighting time. In this paper, a parallel multi-lamp which can have the same output under the same condition is designed. For this, 18 inch LCD monitor with four lamps is used. An inverter for multi-lamp driving is also used in this study. The newly designed inverter shows more than $90\%$ efficiency in its brightness input and output. Besides, it is also available for a multi-drive of other lamps.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.5 no.2
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• pp.49-57
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• 1991

A simple system to measure the correlated color temperature ($T_c$) and color rendering index ($R_a$) oflight sources was developed. And the T, and R, of incandescent lamps (I/L) and various fluorescent lamps(F/L) were measured with varying source voltage and power frequency. As results, $T_c$ variations of I/L and F/L with varying source voltage were relatively large, but $R_a$, variations were small. And $T_c$, $R_a$, variations of F/L under 5OkHz of power frequency were small, but over 50kHz, it is supposed that $T_c$, and $R_a$, will vary significantly.

• The Transactions of the Korean Institute of Power Electronics
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• v.5 no.5
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• pp.501-507
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• 2000

A nobel low-cost, simple and unity-power-factor electronic ballast is presented. The proposed electronic ballast employs a bypassing capacitor- and load networks composed of ballast capacitors and small charge pump capacitors as power factor correction circuit combined with the secondary winding of the transformer in the self-excited current-fed push-pull resonant inverter(CF-PPRI), resulting in cost-effectiveness and higher efficiency. By analyzing the princip1es of power factor correction mathematically, optimum design guidelines are presented. Since the lamps are used in power factor correction stage, the input power is automatically adjusted according to the number of the lamps.