• Journal of Bio-Environment Control
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• v.13 no.2
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• pp.112-119
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• 2004

Objective of this research was to evaluate the effects of nutrient solution strength and Arbuscular Mycorrhizal Fungi (AMF, Glomus sp.) on growth and flowering of potted miniature rose (Rosa hybrids L. cv 'Scarlet'). To achieve this, plants cultured with six different strength of Japanese Horticultural Experiment Station solution (0.125, 0.25, 0.5, 1.0, 2.0, and $4.0\;{\times}\;{full}$ strength) and inoculated with AMP at cutting and transplanting. Leachate EC increased as solution strength were elevated. The leachate EC were not different between non-inoculated plants and AMF treatment at cutting, but significantly decreased when plants were inoculated with AMF at transplanting. The elevated strength of nutrient solution resulted in decrease of leachate pH. When plants were inoculated AMF at transplanting, leachate pH was lower than those of non-inoculated plants and inoculated with AMF at cutting. At harvesting (93 days after transplanting), plant height, leaf width, number of branches and shoot fresh and dry weight of rose 'Scarlet' increased with elevated nutrient solution strength. AMF treatment at transplanting of potted rose 'Scarlet' showed the best results in growth such as chlorophyll content, number of flowers, and shortening the days required to flower. The content of N, P, K, and Mn in leaf tissue of potted rose increased by elevated nutrient solution strength and AMF treatment, while the tissue Na contents decreased by an AMF treatment.

• FLOWER RESEARCH JOURNAL
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• v.18 no.2
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• pp.147-150
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• 2010

A new cultivar potted miniature rose (Rosa hybrida) 'Tiny Ball' was selected out of cross combination 1999 and 2002 at Gumi Floricultural Experiment Station. Characteristics trials were conducted three times from 2003 to 2006. 'Tiny Ball' came from the combination that '990905' crossed to 'Manish'. New cultivar has pink and white flower color and the shape of flower is similar to tiny ball. The number of flower petals and flowers per pot are more than those of 'POULra022' as comparison cultivar. This cultivar has low plant height without treatment of plant retardant materials, so the high quality grade ratio of potted rose is higher than that of comparison cultivar.

• Journal of Electrical Engineering and Technology
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• v.10 no.3
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• pp.1075-1080
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• 2015

A hybrid electric vehicle (HEV) powertrain has more than one energy source including a high-voltage electric battery. However, for a high voltage electric battery, the average current is relatively low for a given power level. Introduced to increase the voltage of a HEV battery, a compact, high-efficiency boost converter, sometimes called a step-up converter, is a dc-dc converter with an output voltage greater than its input voltage. The inductor occupies more than 30% of the total converter volume making it difficult to get high power density. The inductor should have the characteristics of good thermal stability, low weight, low losses and low EMI. In this paper, Mega Flux^® was selected as the core material among potential core candidates. Different structured inductors with Mega Flux^® were fabricated to compare the performance between the conventional air cooled and proposed potting structure. The proposed inductor has reduced the weight by 75% from 8.8kg to 2.18kg and the power density was increased from 15.6W/cc to 56.4W/cc compared with conventional inductor. To optimize the performance of proposed inductor, the potting materials with various thermal conductivities were investigated. Silicone with alumina was chosen as potting materials due to the high thermo-stable properties. The proposed inductors used potting material with thermal conductivities of 0.7W/m·K, 1.0W/m·K and 1.6W/m·K to analyze the thermal performance. Simulations of the proposed inductor were fulfilled in terms of magnetic flux saturation, leakage flux and temperature rise. The temperature rise and power efficiency were measured with the 40kW boost converter. Experimental results show that the proposed inductor reached the temperature saturation of 107℃ in 20 minutes. On the other hand, the temperature of conventional inductor rose by 138℃ without saturation. And the effect of thermal conductivity was verified as the highest thermal conductivity of potting materials leads to the lowest temperature saturations.

• Horticultural Science & Technology
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• v.34 no.1
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• pp.55-66
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• 2016

This study was carried out to investigate the effect of artificial light sources with different light qualities on the growth and flowering characteristics of a herbaceous long-day plant, Petunia ${\times}$ hybrida Hort. Seedlings of petunia cultivar 'Madness Rose' were potted, acclimated for one week, and grown in a phytotron equipped with tube- and bulb-type fluorescent lamps (FL tube and bulb), tube-type white light-emitting diodes (LED tube), halogen lamps (HL), metal halide lamps (MH), and high pressure sodium lamps (HPS) for 10 weeks. The temperature, photoperiod, and photosynthetic photon flux density (PPFD) in the phytotron were $22{\pm}2^{\circ}C$, 16 h, and $25{\pm}2{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, respectively. Light sources combined with HL promoted stem elongation, and plant height and internode length decreased with increasing red to far-red (R:FR) ratio. FL tube + LED tube, HPS, and FL tube promoted branching, whereas plants grown under light sources combined with HL did not have any branches. Days to flowering (from longest to shortest) occurred as follows: FL tube + HL > FL tube + HL > MH > HPS = FL tube + FL bulb > FL tube + LED tube > LED tube > FL tube, indicating that reducing the R:FR ratio of the light sources promoted flowering. Only 20% of plants grown under an FL tube flowered, whereas under all other treatments, 100% of plants flowered. At 10 weeks after treatment, plants grown under HPS and MH had (cumulatively) 12 open flowers, and those grown under FL tube + FL bulb, LED tube, FL tube + LED tube, and HPS treatment had approximately seven flower buds. These results suggest that light sources with low R:FR ratios promote flowering and stem elongation in petunia, but they reduce its ornamental value due to overgrowth and poor branching.

• Horticultural Science & Technology
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• v.33 no.2
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• pp.292-297
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• 2015

A new cultivar of Hibiscus 'Red Bohanjae' (Hibiscus syriacus 'Red Bohanjae') was developed after crossing between Hibiscus syriacus 'Andong' (♀) with white flowers and Hibiscus syriacus 'Samchully' (♂) with pink flowers to improve flower quality and growth habit. The Hibiscus breeding program was initiated in 2002, and H. syriacus 'Red Bohanjae' was preliminarily selected as '02-RV-17' in 2003 due to its stable flower quality with rich pink flowers and small tree type. The selected line was further evaluated for growth characteristics, leaf shape, leaf size, flowering characteristics, and tested for distinctness, homogeneity, and stability during 2004-2007. The characteristics preserved by grafting. 'Red Bohanjae' showed a small growth habit with slightly upright branches. The tree had potential use as a potted plant or bonsai because of its dwarf form. The new cultivar 'Red Bohanjae' had violet-pink color flowers (RHS N78C) with red eye spots, small size (9.2 cm) and spatulate (I-type) petals. Leaves were 4.2 cm long and 2.3 cm wide. After the evaluation of plant characteristics for 3 years (2005-2007), it was registered as cultivar 'Red Bohanjae' (4118, plant variety protection rights number) in 2012. 'Red Bohanjae' having violet-pink flowers with red eye and dwarf tree form seems to be suitable for pot or bonsai cultivation in both indoor and outdoor conditions.

• FLOWER RESEARCH JOURNAL
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• v.18 no.3
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• pp.186-192
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• 2010

An infrared heating system, installed in a small venlo-type glasshouse ($280m^2$) in Gyeongsang National University, Jinju, Korea, was used to investigate its heating effect with potted Phalaenopsis, Schefflera arboricola 'Hongkong', Ficus elastica 'Variegata', and Rosa hybrida 'Yellow King' as the test plants. Temperature changes in test plants with the system turned 'On' and 'Off' were measured by using an infrared camera and the consumption of electricity by this infrared heating system was measured and analyzed. In potted Phalaenopsis, when the set air temperature of the greenhouse was $18^{\circ}C$, temperature of leaves and the growing medium were $22.8{\sim}27^{\circ}C$ and $21.3{\sim}24.3^{\circ}C$, respectively. In such tall plants as Schefflera arboricola 'Hongkong' and Ficus elastica 'Variegata', the upper part showed the highest temperature of 24.0 and $26.9^{\circ}C$, respectively. From the results of temperature change measurements, the plant temperatures were near or above the set point temperatures with some fluctuations depending on the position or distance from the infrared heating system. When air temperature between night and dawn dropped sharply, plant temperatures were maintained close to the set temperature ($18^{\circ}C$). There was a significant difference between 'On' and 'Off' states of the infrared heating system in average temperatures of root zone and leaf: 21.8 and $17.8^{\circ}C$ with the system 'On' and 20.4 and $15.5^{\circ}C$ with the system 'Off', respectively, in a cut rose Rosa hybrida 'Yellow King'. The heating load was about $24,850{\sim}35,830kcal{\cdot}h^{-1}$, which comes to about 27,000~40,000 won in Korean currency when calculated in terms of the cost of heating by a hot water heating system heated by petroleum. The cost for heating by the infrared heating system was about 35% of that of a hot water heating system. With the infrared heating system, the air temperature during the night was maintained slightly lower than the set point air temperature, probably due to the lack of air tightness of the glasshouse. Therefore, glasshouses with an infrared heating system requires further investigation including the installation space of the heat-emitting units, temperature sensor positions, and convection.