• Korean Journal of Mathematics
• /
• v.16 no.1
• /
• pp.41-49
• /
• 2008

We show the existence of a negative solution for the system of the following nonlinear wave equations with critical growth, under Dirichlet boundary condition and periodic condition $$u_{tt}-u_{xx}=au+b{\upsilon}+\frac{2{\alpha}}{{\alpha}+{\beta}}u_+^{\alpha-1}{\upsilon}_+^{\beta}+s{\phi}_{00}+f,\\{\upsilon}_{tt}-{\upsilon}_{xx}=cu+d{\upsilon}+\frac{2{\alpha}}{{\alpha}+{\beta}}u_+^{\alpha}{\upsilon}_+^{{\beta}-1}+t{\phi}_{00}+g,$$ where ${\alpha},{\beta}>1$ are real constants, $u_+={\max}\{u,0\},\;s,\;t{\in}R,\;{\phi}_{00}$ is the eigenfunction corresponding to the positive eigenvalue ${\lambda}_{00}$ of the wave operator and f, g are ${\pi}$-periodic, even in x and t and bounded functions.

• Preventive Nutrition and Food Science
• /
• v.18 no.4
• /
• pp.292-295
• /
• 2013

Fermented whey solution presenting bifidogenic growth stimulation (BGS) activity was processed as prototypes such as sterilized fermented whey (SFW), spray-dried fermented whey (SDFW), and freeze-dried fermented whey (FDFW) and their BGS activities were compared. In optical density ($OD_{600}$) test, the BGS activity of three prototypes, which showed similar activities, were significantly different with non-fermented whey solution adjusted to pH 4.5 as a control (P<0.05). In viable cell count test, SDFW had the most positive influence than other prototypes on the BGS activity even though the difference was not significant. However, the activities of all prototypes were significantly different than the negative control (no addition). These results indicate that the processed prototypes of fermented whey solution show BGS activities and might be commercialized, with further evidences, in animal or human studies.

• Journal of Bio-Environment Control
• /
• v.5 no.2
• /
• pp.236-247
• /
• 1996

The main objective of this study was to evaluate the effectiveness of nutrient solutions, substrates, and nutrient solution concentrations in substrate culture of radish(Raphanus sativus L. var. sativus). Cooper's, Hoagland ＆ Arnon' 5, and Yamazaki's solution were used to determine the most suitable nutrient solution in deep flow culture(DFC). In result, Yamazaki's solution treatment showed better results than Hoagland's and Cooper's solution treatments in leaf length, leaf number, shoot and root fresh weights. Cooper's solution was much worse than others. Root shape index were low as 0.6 in all treatments. The selection of suitable was conducted among 14 kinds of substrates which were used commercially, such as sand, perlite and peatmoss, in substrates culture. Sand was the most proper in radish growth and shortened the growth periods. Sand also showed better results then others in leaf length, leaf number, shoot and root fresh weight. On the contrary, radish growth in peatmoss was the worst. Generally, root shape index was higher in substrate than in DFC. In order to investigate the suitable ionic strength in radish, Yamazaki's solution was treated with EC of 0.5, 1.0, 1.5, and 2.0 mS/cm. Generally radish growth above 1.0 mS/cm concentration was good, and the best result was shown in 1.5 mS/cm. Vitamin C contents were not significantly different in the roots of radish grown under 1.0 mS/cm or more. The highest vitamin C content was shown in 0.5 mS/cm, and so was thiocyanate content. Anthocyanin contents increased with the increase of the ionic strength in nutrient solution. Mineral nutrient contents had no significant statistical differences between the treatments, but potassium content was remarkably high in 1.5 mS/cm.

• Journal of Animal Environmental Science
• /
• v.15 no.1
• /
• pp.51-58
• /
• 2009

The compost leachate was dark-colored solution that leaches out of the bottom of the compost pile. The compost leachate was rich in nutrients and can potentially used in plant culture. In the organic production, commercial liquid fertilizer was used to insure the availability of nutrients during the formation of the yield. The cost of supplemental liquid fertilizer could be reduced by developing a fertilizer based on animal fertilizer. This experiment was conducted to investigate the effect of different combination of compost leachate and conventional inorganic solution in hydroponic culture for lettuce growth. Six different treatments were applied. The compost leachate(CL) and nutrient solution(NS) were mixed by six different mixing ratios of 0:100, 20:80, 40:60, 60:40%, 80:20 and 100%:0% based on nitrogen content. The chemical nutrient solution was the solution of National Horticulture Research Station for the growth of leaf lettuce. The concentration of nutrient solution was adjusted 1.5 mS/cm in EC. The compost leachate was low in phosphorus(P), calcium(Ca), magnesium(Mg), but rich in potassium(K). The plant height of lettuce treated with CL 20+NS 80% was similar with 100% NS of control plot. Plant height was highest in the plot of CL 20+NS 80%. The treatment of 100% compost leachate was lowest in the growth characteristics of leaf lettuce. Number of leaf was very low in 100% compost leachate compared with plot of chemical nutrient solution. In the beginning of growth stage, SPAD value was reduced in plot treated with CL100%, but CL20+NS80% plot was higher compared to 100% compost leachate. SPAD value of leaf lettuce leaves was decreased as the amount of CL was increased. The dry weight of lettuce were 107.4, 104.2g in plot of NS 100% and CL 20%+NS80%, respectively. The leaf number and plant weight were decreased at high application plots of compost leachate. The leaf lettuce showed lowest in the plot treated with 100% compost leachate, and the growth of lettuce severely decreased after application of 100% CL treatment. The results showed that compost leachate can be use as liquid fertilizer for the organic hydroponic production. The mixture solution of 20% of compost leachate and 80% of nutrient solution could be used as a nutrition solution in hydroponic culture of leaf lettuce. Our studies have shown that is possible to produce using compost leachate, although growth is slower than when using a conventional inorganic hydroponic solution.

• Proceedings of the Korea Association of Crystal Growth Conference
• /
• 1997.06a
• /
• pp.115-120
• /
• 1997

We have developed new algorithms for solution of the three-dimensional, time-dependent Navier-Stokes equations that utilize massively parallel supercomputing implemented on the Connection Machine 5. Here, we apply these techniques to analyze he fluid flows that occur during the growth of the tow nonlinear optical crystals-potassium dihydrogen phosphate (KDP), which is producted in a novel rapid growth system under development by the Lawrence Livermore National Laboratory Laser Division, and Potassium titanyl phosphate(KTP), which is grown from a high-temperature aqueous solution.

• Proceedings of the Korea Association of Crystal Growth Conference
• /
• 1997.06a
• /
• pp.149-155
• /
• 1997

We have successfully grown colorless and transparent Rb-doped potassium niobate (KRN) single crystals using the top seeded solution growth(TSSG) technique. In our crystal growth experiments, the Rb doping concentrations within the melt range from 2-15 mol% relative to that of Nb$_2$O5. Atomic absorption measurements indicate that the Rb content in the KRN solid solution is rather low; the Rb segregation coefficient is found to be on the order of 0.05. It is believed that this is due to the relatively much larger Rb+ ionic radius compared to that of K+, rendering it more difficult for Rb to replace K in the KNbO$_3$(KN) host lattice. Preliminary single-pass second harmonic generation (SHG) experimental results indicate that there exists marginal improvement in the phase-matching temperature tolerance of KRN compared to that of pure Kn single crystals.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 1993.10a
• /
• pp.516-516
• /
• 1993

This study was carried out to develop an environment -controlled vegetable growth system. The control objects considered were light, temperature, humidity, $CO_2$ concentration and the conditions of nutrient solution such as pH , EC and dissolved oxygen. A monitoring system was developed to measure the above environmental factors, fresh weight and $CO_2$consumption rate. The overall performance of the developed system was reasonably acceptable for vegetable growth. by the lettuce growing test, it was shown that the developed system had a good repeatability , and the growth responses could be measured satisfactorily.

• Korean Journal of Organic Agriculture
• /
• v.5 no.2
• /
• pp.105-115
• /
• 1997

This experiment was conducted to clarify the plant growth promoting effect of compost supplemented with cultured solution of photosynthetic bacteria(Rhodopseudomonas capsulatus) before sowing on the early growth of plug seedling of tomato and to evaluate the optimum concentration of bacterialization. Bacterializing concentrations(v/w) to the compost were 2%, 3.3%, 10%, 20% and 50%, respectively. Plant growth in terms of plant height, stem diameter, leaf area, total fresh and dry weight were promoted by the bacterialization of photosynthetic bacteria. Especially, in the plots supplemented with 10 to 20% the early growth was promoted markedly over 2 times. Compositions of photosynthetic bacteria consisted of crude protein 60.7%, soluble carbohydrates 20.1%, crude fat 7.6%, crude fiber 3.2% and crude ash 4.8, respectively.

• Applied Science and Convergence Technology
• /
• v.27 no.2
• /
• pp.38-41
• /
• 2018

We demonstrate the growth of a sheet-like ZnO membrane on ZnO nano rod layers. The growth process is composed of 3 steps of ZnO seed formation, ZnO nano rod growth and sheet-like ZnO membrane formation on those nano rods. To confirm the fundamental growth mechanism, the lattice structures of each step were analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM) measurement. Analysis of the relation between the texture coefficient and the surface shape of the ZnO membrane on the ZnO nano rods shows that the surface morphology of ZnO nano structures can be controlled using the temperature of the growing solution and the concentration of the chemical solution.

• Journal of the Korea Furniture Society
• /
• v.29 no.1
• /
• pp.18-23
• /
• 2018

The purpose of this study was to develop wood pots for create Optimum environment of plant growth using unused wood. to prove this, we examined the effects of cycle of water supply and nutrient concentration in wood pots on plant germination rate and growth factors (leaf number, stem diameter and length). The results are as follows. 1) The growth rate was higher at once of 2 days watering period. This suggests that the growth of the plants was better than that of the less water because the larch pots itself has the water retention capacity inside. 2) Germination rate and growth rate were better than other treatment groups when the concentration of nutrient solution was 0.5%. 3) Nitrogen, available phosphoric acid, and potassium showed higher contents than the nutrient - treated soil at 0.5% concentration of nutrient solution. This indicates that the nutrient solution absorbed from the larch affected the soil and plant growth in the inside.