• Journal of Bio-Environment Control
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• v.29 no.4
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• pp.365-372
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• 2020

This study was conducted to compare the effects of foliar spray and sub-irrigation of the triazole fungicide diniconazole on the regulation of stem elongation and to investigate the stimulation of root system development during the seedling stage. Comparing the two application approaches, there were significant differences in the leaf area, leaf area ratio (LAR), plant height, compactness, fresh shoot and root production, relative growth rate (RGR), and root to shoot ratio (R/S). At the same application concentration, the sub-irrigation showed a better retarding effect on growth than the foliar spray, because the PGR activity of diniconazole in root absorption was higher than that in shoot absorption. For reaching a target of 20% to 30% inhibition rate of stem length, foliar application concentration of diniconazole exceeded 10, however, only approximately 1 was required in the sub-irrigation application. The root system of tomato seedlings responded strongly to diniconazole application. Total root length, root volume, root average diameter, and the number of root tips increased when diniconazole was sub-irrigation application at 1. A reduction in fine roots (diameter range of 0 to 0.3 mm) and an increase in the roots with a diameter range of 0.3 to 0.6 mm was observed, and this may contribute to the increase in average diameter. The increase in root average diameter may be positive because root penetration increases with root diameter. Our results suggested that sub-irrigation maximized the PGR activity of diniconazole to enhance the retarding effect. And it also possible to enhance the tomato seedling root system by diniconazole stimulating with a lower concentration.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.4
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• pp.420-428
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• 1988

Root is supposed to be important role in growth and yield formation of soybeans and also there is expected to exist varietal differences between soybean root morphology and system. 30 soybean varieties including 10 Korean recommended, 10 Introduced and 10 Korean native varieties were grown at field and pot under standard culture condition. Top and root characteristics were investigated at V4, R1 and R5 stage and T/R relations, correlations with yield were calculated. Top characteristics showed significant difference between 3 variety groups of Korean recommended, Introduced and Korean native variety. Stem length at R1 stage and stem length, stem diameter, number of nodes, number of branches, number of pods and grain yield at R5 stage were significantly different top characteristics. Root characteristics showed significant difference between 3 variety groups were number of thick primary root at V4 stage, primary root angle and root cutting strength at R1 stage, thick root diameter and root dry weight at R5 stage. The correlations between top and root characteristics and soybean yield was greatly different by soybean variety groups, and the top characteristics was more highly correlated then root characteristics. All the top and root characteristics of Korean recommended variety showed no correlations with yield. However, leaf area, stem length, top dry weight in Introduced variety and leaf area, top dry weight, number of nodes, number of thick primary root in Korean native variety were highly correlated with soybean yield.

• Korean Journal of Environmental Agriculture
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• v.18 no.1
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• pp.35-40
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• 1999

$N(^{15}N)$ and $P(^{32}P)$ absorption by 2 year-old Cymbidium Jungfrau in solution culture were investigated. Growth, photosynthesis rate, chlorophyll content and mineral composition of Cymbidium in the solution culture with bark or granular rockwool were compared with these parameters in the conventional pot culture. Nitrogen absorption by Cymbidium was higher in full sunlight than in 60% of sunlight while P absorption was higher in 60% of sunlight. Sixty seven % of N absorbed in plant was redistributed to the bulb(39%) and leaves(28%) while 46% of P absorbed was fund in the bulb (36.2%) and leaves (10.2%). Accumulation of P in leaves was 3-fold lower than that of N. N and P absorption in 0.5 or 1 year- old daughter plant Bowing vigorously were greater than in immature daughter or mother plant. The absorption rate of phosphorus in Cymbidium was 350-fold lower than that of barley. Greater shoot length and bulb diameter, and higher fresh weight, photosynthesis rate and chloroployll content were observed in the solution culture than in the conventional pot culture. Solution culture had-also more content of N, P, K and Mg in leaves, bulb and root than conventional pot culture but did not that of Ca. A large part of the nutrient absorption was occurred during vegetative growth. Also, There was no difference between bark and rockwool in the solution culture due to the improvement of poor dispersion of nutrient solution in bark.

• Journal of Forest and Environmental Science
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• v.36 no.1
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• pp.1-6
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• 2020

This study was conducted to investigate the effect of different pre-sowing treatments of seeds on germination and growth performance of native threatened tree species Quercus gomeziana A. Camus at the nursery of Chittagong University, Bangladesh. Furthermore, seedling growth attributes under different doses of fertilizer (urea) was also experimented to find the best dose of fertilizer on this tree species at the nursery stage for better field level growth. Seeds were placed to six pre-sowing treatments e.g. control (PT₀), treated with sand paper rubbing (PT₁), nicking (PT₂), seeds immersed in cold water for 48 hours (PT₃), seeds immersed in cold water for 7 days (PT₄) and seeds sown at propagator house with increased temperature (PT₅). It was found from the study that germination was started earlier (at 31 days) in treatments sand paper rubbing (PT₁) and nicking (PT₂). The highest germination percentage (93%) was in PT₁ followed by 86% in seeds immersed in cold water for 7 days (PT₄) and 80% in PT₀ (control). Germination percentage was observed least (63%) in PT₂ even though germination started earlier. For fertilizer dose experiment to seedlings at the nursery level, treatment FT₁: 100 kg/ha (0.33679 g urea/pot/seedling) comparing with other treatments FT₀: 0 kg/ha (Control), FT₂: 200 kg/ha (0.67358 g urea/pot/seedling), FT₃: 300 kg/ha (1.01037 g urea/pot/seedling) showed better performance in case of collar diameter (6.74 mm), number of leaves, shoot dry weight (19.74), total dry weight (28.16 g), total fresh weight (67.96 g), volume index (3904.82), sturdiness (127.69). Finally, it can be concluded that Quercus gomeziana seedlings revealed better performances under the treatment FT₁ in growth and biomass production. Findings of this study will be helpful to take decision on organic fertilizer dose application to seedlings of Q. gomeziana for large scale plantation and conservation of this species.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.381-390
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• 2018

This study was conducted to examine the growth characteristics of seedlings of several major fruit vegetables and compare them between plants grown with the conventional plug seedling system (Plug) and those grown with the cylindrical paper pot system (CPP). There were no significant differences in shoot growth characteristics, such as plant height, leaf area, dry weight, and fresh weight, between tomato, cucumber, and watermelon plants grown with the CPP and Plug systems. The total root lengths of tomato and cucumber plants grown with Plug were longer than those grown with CPP at the beginning of seedling growth, and the total root lengths of watermelon grown with Plug were longer than those grown with CPP throughout the whole seedling period. The length of root that separated five steps according to the diameter of the root of tomato did not differ between CPP and Plug, but those of cucumber and watermelon were 20-251% longer with Plug than with CPP for all kinds of roots. The fresh weight of Plug-grown tomato roots was about 30% heavier than that of CPP-grown tomato during the seedling period, but the difference decreased as growth progressed. Finally, there was no difference between plants before and after transplanting. The fresh weights of the Plug-grown plants were about 20-30% heavier than those of CPP-grown ones in terms of the whole seedling. After transplanting to the Wagner pot, the shoot growth of Plug-grown watermelon plants in terms of dry weight was low until 7 days had passed. However, this tendency was reversed from 8 days after transplantation onward. In conclusion, there were no significance differences in the growth of shoots between plants grown with the CPP and Plug systems. However, root development was better with Plug than with CPP.

• Journal of Soil and Groundwater Environment
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• v.19 no.3
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• pp.25-32
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• 2014

The amount of TPH contaminated soil treated at off-site remediation facilities is ever increasing. For the recycle of the treated-soil on farmlands, it is necessary to restore biological and physico-chemical soil characteristics and to remove residual TPH in the soil by an economic polishing treatment method such as phytoremediation. In this study, a series of experiments was performed to select suitable plant species and to devise a proper planting method for the phyto-restoration of TPH-treated soil. Rye (Secale cereale) was selected as test species through a germination test, among 5 other plants. Five 7-day-old rye seedlings were planted in a plastic pot, 20 cm in height and 15 cm in diameter. The pot was filled with TPH-treated soil (residual TPH of 1,118 mg/kg) up to 15 cm, and upper 5 cm was filled with horticulture soil to prevent TPH toxic effects and to act as root growth zone. The planted pot was cultivated in a greenhouse for 38 days along with the control that rye planted in a normal soil and the blank with no plants. After 38 days, the above-ground biomass of rye in the TPH-treated soil was 30.6% less than that in the control, however, the photosynthetic activity of the leaf remained equal on both treatments. Soil DHA (dehydrogenase activity) increased 186 times in the rye treatment compared to 10.8 times in the blank. The gross TPH removal (%) in the planted soil and the blank soil was 34.5% and 18.4%, respectively, resulting in 16.1% increase of net TPH removal. Promotion of microbial activity by root exudate, increase in soil permeability and air ventilation as well as direct uptake and degradation by planted rye may have contributed to the higher TPH removal rate. Therefore, planting rye on the TPH-treated soil with the root growth zone method showed both the potential of restoring biological soil properties and the possibility of residual TPH removal that may allow the recycle of the treated soil to farmlands.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.1
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• pp.21-28
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• 2000

Although commercial PIV systems have been widely used for the non-intrusive velocity field measurement of fluid flows, they are still under development and have considerable room for improvement. In this study, a single-frame double-exposure PIV system using a high-resolution CCD camera was developed. A pulsed Nd:Yag laser and high-resolution CCD camera were synchronized by a home-made control circuit. In order to resolve the directional ambiguity problem encountered in the single-frame PIV technique, the second particle image was genuinely shifted in the CCD sensor array during the time interval dt. The velocity vector field was determined by calculating the displacement vector at each interrogation window using cross-correlation with 50% overlapping. In order to check the effect of spatial resolution of CCD camera on the accuracy of PIV velocity field measurement, the developed PIV system with three different resolution modes of the CCD camera (512 ${\times}$ 512, lK ${\times}$ IK, 2K ${\times}$ 2K) was applied to a turbulent flow which simulate the Zn plating process of a steel strip. The experimental model consists of a snout and a moving belt. Aluminum flakes about $1{\mu}m$ diameter were used as scattering particles for the liquid flow in the zinc pot and the gas flow above the zinc surface was seeded with atomized olive oil with an average diameter of 1-$3{\mu}m$. Velocity field measurements were carried out at the strip speed $V_s$=1.0 m/s. The 2K ${\times}$ 2K high-resolution PIV technique was significantly superior compared to the smaller pixel resolution PIV system. For the cases of 512 ${\times}$ 512 and 1K ${\times}$ 1K pixel resolution PIV system, it was difficult to get accurate flow structure of viscous flow near the wall and small vortex structure in the region of large velocity gradient.

• Bulletin of the Korean Chemical Society
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• v.33 no.10
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• pp.3218-3224
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• 2012

Uniform and well dispersed metal sulfide semiconductor nanoparticles incorporated into matrices of alginate biopolymer are prepared by using a facile in situ method. The reaction was accomplished by impregnation of alginate with divalent metal ions followed by reaction with thioacetamide. XRD analysis showed that the nanoparticles incorporated in the polymer matrix were of cubic structure with the average particle diameter of 1.8 to 4.8 nm. Field emission scanning electron microscopy and high resolution transmission electron microscopy images indicated that the particles were well dispersed and distributed uniformly in the matrices of alginate polymer. FT-IR spectra confirmed the presence of alginate in the nanocomposite. The crystalline nature and thermal stability of the alginate polymer was found to be influenced by the nature of the divalent metal ions used for the synthesis. The proposed method is considered to be a simple and greener approach for large scale synthesis of uniform sized nanoparticles.

• Bulletin of the Korean Chemical Society
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• v.30 no.11
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• pp.2713-2716
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• 2009

$CuInS_{2}$ nanoparticles were synthesized by a simple sonochemical method; First, Cu nanoparticles were prepared from $CuInS_{2}$ in methanol solution by a one pot reaction through the sonochemistry under multibubble sonoluminescence (MBSL) conditions. Second, the resulting Cu nanoparticles were treated with $InCl_3{\cdot}4H_2O$ and $CH_3CSNH_2$ (thioacetamide) at the same MBSL conditions to synthesize $In_2S_3$-coated Cu nanoparticles in methanol solution. Then, they were transformed into $CuInS_{2}$ (CIS) nanoparticles of 20 $\sim$ 40 nm size in diameter by thermal heating at 300 ${^{\circ}C}$ for 2 hr. The prepared CIS nanoparticles, of which band gap is 1.44 eV, were investigated by X-ray diffractometer, UV-Vis spectrophotometer, inductively coupled plasma spectrometer, and high resolution-transmission electron microscope.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.1
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• pp.107-111
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• 2006

This study was to verity that the uptake inhibition and accumulation of nitrogen in different potassium levels. Lettuce was used as model plant in this study and grown in pot of 10cm's in diameter and depth with mixture media of vermiculite and perlite under supply of different culture solution for three weeks. Nitrogen absorption at root was inhibited by increased potassium concentration in nutrient solution, and nitrate accumulation of plant was depended on absorption of nitrogen because nitrate content of 0 K level was 4-5 times higher than that of 2 K level, Concentration of ascorbic acid was decreased by increasing the nitrogen absorption, since ascorbic acid (AsA) content of 2K level was higher than those of OK level in both of old leaf and flesh leaf.