• Korean Chemical Engineering Research
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• v.43 no.1
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• pp.80-84
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• 2005

Nano-sized $Y_2O_3:Eu$ phosphor particles were prepared by ultrasonic spray pyrolysis. The effect of polymeric precursor and lithium carbonate flux on the morphology and luminescence characteristics of nano-sized $Y_2O_3:Eu$ phosphor particles was investigated. When using the spray solution containing both the polymeric precursor and the flux, the $Y_2O_3:Eu$ particles with spherical shape and micron size were turned into nano-sized $Y_2O_3:Eu$ phosphor particles during the post-treatment at high temperature. The mean size of $Y_2O_3:Eu$ phosphor particles was affected by the contents of polymeric precursors and lithium carbonate flux, and preparation temperature. The as-prepared particles by spray pyrolysis at high temperature from solution containing high contents of polymeric precursors had good photoluminescence intensity under vacuum ultraviolet after post-treatment above $1,000^{\circ}C$. The prepared nano-sized $Y_2O_3:Eu$ phosphor particles had comparable photoluminescence intensity under vacuum ultraviolet light with that of the commercial $Y_2O_3:Eu$ phosphor particles prepared by solid state reaction method.

• Horticultural Science & Technology
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• v.32 no.6
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• pp.872-878
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• 2014

This study aimed to enhance storage and freshness of strawberry fruits and foliage vegetables by spray treatment with Chlorella vulgaris as a bio-fertilizer. The tested strain, C. vulgaris CHK0008, was isolated from an organically cultivated rice paddy and identified as C. vulgaris by its morphology and 18S rDNA and 23S rDNA sequence homology. We successfully cultured C. vulgaris CHK0008 in BG11 modified medium (BG11MM) and adjusted $2.15{\times}10^6cell/mL$ C. vulgaris CHK0008 to one OD value by measuring the optical density at 680 nm using a UV-vis spectrophotometer. The soluble solid content of 'Seolhyang' and 'Yukbo' strawberry fruits treated by spray application with C. vulgaris CHK0008 was enhanced by 22.2% and 11.5% respectively, compared to untreated controls. Additionally, the decay rates of treated 'Seolhyang' and 'Yukbo' strawberry fruits decreased 63.8% and 74.4% respectively, compared to untreated control. Surface color changes and chlorosis of leaves in leaf vegetables such as lettuce, kale, red ornamental kale, white ornamental kale and beet were observed in samples treated with water spray for 10 days after cold storage. However, the decay rate of leafy vegetables treated with foliar application of 25% C. vulgaris CHK0008 liquid culture was significantly decreased compared to that of the untreated control during storage at $4^{\circ}C$.

• Journal of the Korean Electrochemical Society
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• v.11 no.4
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• pp.297-303
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• 2008

$LiNiO_2$ cathode powders with fine size have been synthesized by spray pyrolysis from the spray solution with citric acid and ethylene glycol. The as-prepared powders with spherical shape, porous structure and micron size turned into $LiNiO_2$ powders with micron size and regular morphology after post-treatment at $800^{\circ}C$. The initial discharge capacities of the $LiNiO_2$ powders changed from 199 to 171mAh/g when the concentrations of the citric acid and ethylene glycol added to the spray solutions were changed from 0 to 1 M. The maximum initial discharge capacity of the $LiNiO_2$ powders obtained from the spray solution with citric acid and ethylene glycol was 198 mAh/g when the lithium component added to the spray solution was 6 mol% excess of the stoichiometric amount. The discharge capacities of the fine-sized $LiNiO_2$ powders dropped from 198 to 163 mAh/g by the 30 th cycle at a current density of 0.1 C.

• Journal of ILASS-Korea
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• v.5 no.3
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• pp.17-26
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• 2000

The main parameter commonly used to evaluate spray distribution is spray angle. Spray angle is important because it influences the axial and radial distribution of the fuel. Spray angles were measured and compared for the two non-air assisted injectors such as 2hole-2stream 4hole-1stream injectors used for port fuel injection gasoline engines with n-heptane as a fuel by three different measuring techniques, i.e., digital image processing, shadowgraphy, and spray patternator, respectively. Fuel was injected with the injection pressures of 0.2-0.35 MPa into the room temperature and atmospheric pressure environment. In digital image processing approach, the selection of the transmittance level is critical to obtain the edge of spray and hence to measure the spray angle. From the measurement results by the shadowgraphy technique, it is dear that the spray angle is varied during the spray injection period. The measurement results from spray patternator show that the different spray angles exist in different region. Spray angle increases with the increase in the injection pressure. it is suggested that the spray angle and stream separated angle should be specified when spray is characterized for 2hole-2stream injector, because spray angle is much different though stream separated angle is same. It was also considerably affected by the measurement techniques introduced in this experimental work. However, the optimal axial distance for measuring the spray angle seems to be at least 60-80 mm from the injector tip for two non-air assisted injectors.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.11
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• pp.1005-1013
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• 2010

This study was conducted to assess the spray control of flash boiling with mixed fuel in consideration of HCCI (Homogeneous Charge Compression Ignition) engine condition. Mixed fuel existing in two phase regions can control the process of mixture formation under low temperature and density by using the spray resulting from flash boiling which is able to induce rapid evaporation of fuel spray as well as the evaporation of high boiling point component. Because HCCI engine injects the fuel early under ambient conditions, it can facilitate the chemical control of ignition combustion and physical control such as breakup and atomization of liquid fuel by flash boiling of mixed fuel which consists of highly ignitable light oil and highly volatile gasoline. This study was conducted by performing video processing after selected composition and molar fraction of the mixed fuel as major parameters and photographed Schlieren image and Mie scattered light corresponding to the flash boiling phenomenon of the fuel spray that was injected inside a constant volume vessel. It was found that flash boiling causes significant changes in the spray structure under relatively low temperature and density. Thus, we analyzed that the flash boiling spray can be used for HCCI combustion by controlling the mixture formation at the early fuel injection timing.

• Applied Biological Chemistry
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• v.42 no.4
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• pp.288-292
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• 1999

It was previously reported that cobalt(II) effectively suppresses the postharvest gravitropic response of snapdragon (Antirrhinum majus L.) (Kim et al. (1997) Agric. Chem. and Biotechnol. 40, 567-571). In this study, several factors affecting the suppression of the gravitropic response by cobalt ion were examined. When flower stalks of snapdragon were pretreated with several different cobalt salts, cobalt nitrate turned out to be the most effective not only in reducing the response but also in preserving the flower quality. We also tested the effects of various detergents which were added to cobalt(II) solution, finding that Tween-40 was the best among the tested with respect to the effectiveness as well as the flower quality. Based on these results, we optimized a protocol for the chemical treatment; that is, a suppressor solution containing 10 mM $CO(NO_3)_2$ and 0.05% Tween-40 was directly sprayed on the gravitropically sensitive region of cut flowers of snapdragon. The suppressor treatment gave rise to a significantly improved results when the flower stalks were stored at a lower temperature after the chemical treatment.

• Korean Journal of Weed Science
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• v.15 no.2
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• pp.141-147
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• 1995

Glyphosate(N-[phosphonomethyl]glycine) applied to the assimilate-exporting leaves or sprayed to the whole plants of tomato(Lycopersicon esculentum Mil var. Moneymaker). Glyphosate induced the rapid accumulation of shikimic acid within 24 h. The accumulation of shikimic acid companied with chlorophyll loss in meristematic leaves, i.e. apical leaves. The chlorosis was acropetal in apical region of young growing leaf. The degradation of chlorophyll seems to be a secondary or tertiary effect of glyphosate. However, the level of shikimic acid accumulated was reduced except for roots and apical leaves from 5 days after treatment. The accumulating levels are considerably differed through the applicated regions. The level of shikimic acid is highest at the apical meristem 4 days after the application to 3rd old leaf.

• Journal of Chitin and Chitosan
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• v.22 no.2
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• pp.110-117
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• 2017

This study was conducted to examine the physicochemical properties and hot air-dried and spray-dried powders process of sweet potato and steamed sweet potato. The moisture and the total starch contents were 1.66~2.19% and 52.65~57.42%, respectively. The total starch contents increased during process steaming. The water absorption index of the spray-dried powders (0.97 and 2.03) was lower than that of the hot air-dried powders (2.12 and 4.71), and the water solubility index of the spray-dried powders (83.83 and 86.95%) was higher than that of the hot air-dried powders (68.40 and 81.21%). The particle size and outer topology of the spray-dried powders were 46.18 and $65.53{\mu}m$, and its shape was generally globular. In the DSC analysis of this study, the $T_o$ of the spray-dried powders (64.40 and $67.80^{\circ}C$), $T_p$ of the spray-dried powders (74.40 and $78.20^{\circ}C$), and $T_c$ of the spray-dried powders (81.10 and $81.60^{\circ}C$) was higher than that of the hot air-dried powders. The solubility contents of the spray-dried powders (68.21 and 80.73%) was lower than that of the hot air-dried powders, and the swelling power contents of the spray-dried powders (14.79 and 15.35%) was higher than that of the hot air-dried powders. The amylose contents of spray-dried powders (11.67 and 12.51%) was lower than that of the hot air-dried powders. The soluble dietary fiber contents of spray-dried powders (1.34 and 2.02%) was higher than that of the hot air-dried powders.

• Journal of Bio-Environment Control
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• v.6 no.4
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• pp.284-291
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• 1997

This study was conducted to evaluate the optimum hydroponic system and nutrient solution for shortening the early growth period and quality improvement of dendrobium ( Dendrobium Phalaenopsis) seedlings. Dendrobium seedlings with 3 to 4 leaves were transplanted in the deep flow technique(DFT) system, aeroponic system, and ebb and flow system with different concentration of balanced nutrient solutions recommended by the Japanese Horticultural Experiment Station. Growth characteristics of shoot and root were recorded and evaulated among treatments. For autumn cultivation, plant height was the longest at the DFT system with quarter concentration of nutrient solution, where aeroponic system with half concentration of nutrient solution. Aeroponic system stimulated the root growth but fresh weight was observed in the plots of DFT system. For spring cultivation, pH values increased up 7.5 at the DFT and aeroponic system, where EC values did not fluctuate regardless of cultural system. Ebb and flow system showed the best result in the growth of plant followed by BFT system and aeroponic system. Higher concentration of nutrient solution within this range of treatment was recommended for the growth promotion of leaf length and width in DFT system. In conclusion, growth responses differed depending on the cultural system, concentrations of nutrient solutions and duration of cltivation.

• Journal of Korean Society of Forest Science
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• v.96 no.6
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• pp.676-683
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• 2007

In an attempt to develop an efficient method for the propagation of mature Prunus yedoensis (45 to 55 years old), green wood cuttings from normal branch and sprouts branch were treated with three different kinds of auxin (Rootone < 1-naphthylacetamide 0.4% >, IBA 100 ppm, and control and two different kinds of fog systems (0.9 L/min. and 0.54 L/min.). The Rootone treatment showed higher values in the percentage of rootings (PR) and the mean number of roots per cutting (NR) than the IBA treatment in the early stage. However, in the late stage, the values of PR and NR in the Rootone treatment become lower than those in the IBA 100 ppm treatment. On the other hand, root development ceased 62 days after taking cuttings for all of the treatments. The IBA 100 ppm treatment showed the best performance in root development (PR= 89.5%, NR = 6.5, LR=6.4 cm). The values of PR (76.5%) and NR (6.4) in the 0.9 L/min. of fog treatment was higher than those (PR = 71.7% and NR = 5.4) in the 0.54 L/min. of fog treatment. The cuttings from sprouts (PR: 74.8%, NR: 5.9, LR: 5.7 cm) showed slightly better performance in rooting rate that the cuttings from shoots (PR : 73.3%, NR: 5.9, LR: 5.4 cm). Statistically significant interactions were presented among most of the different combinations of three factors (auxin treatments, fog treatments, and types of cuttings). The PR showed the highest value of 98.0% in the combination of cuttings of shoots+IBA 100 ppm+0.54 L/min. fog treatments. In case of NR, the cuttings from normal branch showed a higher value than the cuttings from sprouts branch under the fog treatment of 0.9 L/min., while this tendency was reversed under the fog treatment of 0.54 L/min.. The perigon development of roots, which reflects the number and the direction of roots, was best in the IBA treatment (85.6%).