• Horticultural Science & Technology
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• v.28 no.3
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• pp.409-414
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• 2010

The first drainage time in a day was controlled for precise irrigation management with low consumption of nutrient solution in tomato perlite bag culture system by measuring water level of drained water in drainage catchment part. This method automatically adjusted the irrigation time under any condition of light, temperature and humidity, resulting in stable water content in substrates. However, it was difficult to keep the time consistent as they were set. It drained with the deviation of 20 min in the treatment in which the first drainage time was set at 10:00 and 50 min in the treatment set at 10:30. The first drainage time was not constant, but the drain occurred stably before noon in the treatment of which irrigation frequency was longer than 30 min. The drainage ratio was better balanced in all the treatments using drainage level sensors than the treatment using time clock for irrigation control. High water and fertilizer efficiencies were obtained. Although the growth, total yield and sugar content were not significantly different between the treatments, fruit weight was higher in the treatments using drainage level sensors than that using timer.

• Korean Journal of Environmental Agriculture
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• v.28 no.2
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• pp.171-178
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• 2009

Water shortages are expected to be a major impact of climate change. This study examined the growth of Chinese cabbage seedling using reclaimed wastewater and waste nutrient solution as alternative irrigation resources. Generally, the concentration of nutrients, such as $K^+$, $NH_4^+$, $Mg^{2+}$, $Ca^{2+}$, $Cl^-$,$NO_3^-$, $PO_4^-$ and $SO_4^{2-}$, in waste nutrient solution was higher than that in wastewater. However, Chinese cabbage seedling irrigated with wastewater was supplied a higher concentration of $Na^+$ and $Cl^-$ than waste nutrient solution. The growth of Chinese cabbage seedling irrigated with waste nutrient solution was similar or higher than those irrigated with groundwater as control, while the growth of those irrigated with wastewater was similar to those irrigated with groundwater. The total nitrogen uptake in Chinese cabbage seedling irrigated with groundwater, waste nutrient solution from organic and inorganic hydroponic cultures, and wastewater was 5.47, 10.02, 5.20, and 4.59 mg/plant, respectively. The nitrogen uptake of Chinese cabbage seedling irrigated with waste nutrient solution from organic hydroponic substrates in a 50% lower dose than recommended was 8.34 mg/plant, which is higher than that of the cabbage irrigated with groundwater. Overall, the results suggest that waste nutrient solution and wastewater can be used as alternate water resources, and can allow a reduction in the amount of fertilizer needed to raise Chinese cabbage seedling.

• Journal of Bio-Environment Control
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• v.25 no.2
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• pp.89-94
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• 2016

This study was conducted to determine the optimum nutrient solution, pH, irrigation interval, light intensity and planting density to growth of common ice plant (Mesembryanthemum crystallinum L.) in a closed-type plant production system. Three-band radiation type fluorescent lamps with a 12-h photoperiod were used. Nutrient film technique systems with three layers were used for the plant growth system. Environmental conditions, such as air temperature, relative humidity and $CO_2$ concentration were controlled by an ON/OFF operation. Treatments were comparison of the nutrient solution of Horticultural Experiment Station in Japan (NHES) and the nutrient solution of Jeju National University (NJNU), pH 6.0 and 7.0, irrigation interval 5 min and 10 min, light intensity 90 and $180{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, and within-row spacing 10 cm, 15 cm, 20 cm and 25 cm with between-row spacing 15 cm. Optimum macronutrients were composed N 7.65, P 0.65, K 4.0, Ca 1.6 and Mg $1.0mM{\cdot}L^{-1}$. There were no significant interactions between pH 6.0 and 7.0 about shoot fresh weight and shoot dry weight of common ice plant. Irrigation interval 5 min and 10 min was also the same result. Shoot fresh weight and shoot dry weight were highest at $180{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. Shoot fresh weight and shoot dry weight were decreased according to increasing the planting density. From the above results, we concluded that optimum nutrient solution, optimum levels of pH, irrigation interval, light intensity and planting density were 6.0-7.0 and 10 min, $180{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ and $15{\times}15cm$, respectively for growth of common ice plant in a closed-type plant production system.

• KCID journal
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• v.1 no.2
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• pp.11-21
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• 1994

A numerical model for conservation form of Saint Venant equations for nonprismatic channels (CFSVE model) is developed. The model is based on a finite difference solution of the Preissmann scheme. The CFSVE model consists of data pre-management program (D

• Journal of Periodontal and Implant Science
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• v.20 no.1
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• pp.153.1-153.1
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• 1990

• Journal of Periodontal and Implant Science
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• v.29 no.2
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• pp.371-387
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• 1999

The present study was performed to assess and compare the clinical and microbiological effects following local application of 2% minocycline gel or 0.1% chlorhexidine subgingival irrigation to augment scaling and root planing in patients with moderate to advanced chronic adult periodontitis. 32 healthy patients with moderate to advanced chronic adult periodontitis were enrolled in the study. In each patient, the quadrants that had 2 or more teeth with $5{\sim}8mm$ probing pocket depth and radiographic evidence of alveolar bone loss were selected and divided into test side and control side according to the split-mouth design. All patients received standardized oral hygiene instructions at the beginning of the study and all remaining teeth received scaling and root planing until 0 week. The 2% minocycline gel was applied to periodontal pocket at 0, 1, 2, 3 week in the test side. The 0.1% chlorhexidine solution and the normal saline were irrigated subgingivally for about 30 seconds in the positive control side and negative control side respectively. The clinical and microbiological analysis carried out at 0, 4, 8, and 12 weeks . The results of this study were as follows; 1. In saline irrigation group, there was no adjunctive effects in probing pocket depth reduction, sulcular bleeding index and no significant changes in relative proportions of subgingival bacteria. 2. The chlorhexidine irrigation as an adjunct to scaling and root planing results in reduction in the plaque index and sulcular bleeding index, but there was not statistically significant. The relative proportion of spirochetes was significantly reduced, but the proportion of motile rods was no significant reduction. 3. The minocycline gel delivered subgingivally as an adjunct to scaling and root planing provide significant benefit in reducing probing depths and sulcular bleeding index compared to saline and chlorhexidine irrigation groups. 4. The relative proportions of spirochetes and motile rods were significantly reduced and the proportions of cocci and non-motile bacteria were correspondingly increased in the minocycline gel group. In conclusion, minocycline gel delivered subgingivally as an adjunct to scaling and root planing induces clinical and microbial responses more favorable for periodontal health than saline and chlorhexidine subgingival irrigation.

• Korean Journal of Environmental Agriculture
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• v.19 no.2
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• pp.128-133
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• 2000

This study was conducted to investigate the adsorptive characteristics with cadmium in different levels of organic matter and lime in soil. And in order to identify the effect of soil ameliorators on cadmium uptake in rice plants, compost and lime were treated. Plants were grown at two soil textures(sandy loam and clay loam) with irrigation water containing $0.01\;mg\;L^{-1}$ of cadmium and treatments of two irrigation systems(intermittent irrigation and continuous submersion). The adsorption capacity of cadmium by soil was increased in proportion to initial concentration of solution, and it was higher at clay soil compared to loamy soil. The adsorption rate of cadmium by soil was increased with increasing the concentration of organic matter and lime in soil, highly increased at the both organic matter and lime treatment. Soil pH was negatively correlated with the cadmium contents of the both shoot and brown rice while Eh was positively correlated with those. In the harvest season, cadmium contents in the both leaves and brown rice were lower in the clay sail plots than sandy soil plots, and the continuous submersion plots were lower than intermittent irrigation plots. Cadmium uptake was highly reduced at the compost and lime mixture plot compared to other treatments among the continuous submersion plots. The cadmium content of shoot was positively correlated with that of brown rice in the harvest season.

• Applied Microscopy
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• v.37 no.4
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• pp.219-230
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• 2007

The morphological effects of intranasal zinc sulfate(5% solution) irrigation on the mouse olfactory epithelium and the regeneration process of olfactory receptor cells following nasal irrigation were studied with scanning and transmission electron microscope. The results were as follows: 1. The septal epithelium except some basal cells was wholly detached from the basement membrane, during the first 6 to 24 hours after 5% zinc sulfate irrigation. 2. 3 days after $ZnSO_4$ treatment, two layered septal epithelium was formed from basal cells. And microvilli were observed in the apical epithelium of newly formed olfactory epithelial cells. 3. 5 days after treatment, a lot of centrosomes and basal bodies were observed in the olfactory receptor cells, and cilia were lined up between microvilli on the apical membrane of olfactory receptor cells. And immature olfactory knob was first observed in the newly formed olfactory receptor cells. Mature olfactory knob was observed 1 week after treatment. 4. There are very many mature olfactory knobs in the olfactory receptor cells 2 weeks after intranasal zinc sulfate irrigation. These results support that treatment with 5% zinc sulfate is a good experimental model for the regeneration of mammalian nervous tissues because this method could thoroughly detach the septal epithelium. During the regeneration of olfactory receptor cells, the surface membrane of the olfactory receptor cells widen the surface with the microvilli. Then cilia, which arranged in a line, substituted for the microvilli. The part of the surface membrane with cilia protruded and finally formed the olfactory vesicle.

• Korean Journal of Environmental Agriculture
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• v.30 no.2
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• pp.125-131
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• 2011

BACKGROUND: Reuse of waste nutrient solution for the cultivation of crops could lead to considerable conservation of water resources, plant nutrients, and water quality. Therefore, this study was conducted to evaluate the potential for reducing the use of chemical fertilizer in Chinese cabbage cultivation via the reuse of waste nutrient solution as an alternative irrigation resource. METHODS AND RESULTS: The nutrients supplied in the waste nutrient solution consisted of 1474.5, 1285.1, 991.6, and 872.6 mg/L for $K+$, ${NO_3}^-$, $Ca^{2+}$ and ${SO_4}^{2-}$, respectively. At 56 days after transplanting (DAT), the leaf length of Chinese cabbage plants irrigated with the waste nutrient solution treatment was significantly higher than that of plants irrigated using a conventional groundwater treatment. Additionally, the leaf width, fresh weight and dry weight of the plants irrigated with the waste nutrient solution were similar or greater than that of plants irrigated with a conventional treatment. Furthermore, the growth of plants treated with the waste nutrient solution +25% fertilizer was the highest among all tested treatments. CONCLUSION(s): These results indicate that the waste nutrient solution can be used as an alternate water resource for crop cultivation. In addition, it can contribute to reduce the fertilizer and to obtain the higher crop yield of Chinese cabbage.

• Restorative Dentistry and Endodontics
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• v.39 no.2
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• pp.104-108
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• 2014

Objectives: To evaluate the effect of passive ultrasonic agitation on the cleaning capacity of a hybrid instrumentation technique. Materials and Methods: Twenty mandibular incisors with mesiodistal-flattened root shape had their crowns sectioned at 1 mm from the cementoenamel junction. Instrumentation was initiated by catheterization with K-type files (Denstply Maillefer) #10, #15, and #20 at 3 mm from the working length. Cervical preparation was performed with Largo bur #1 (Dentsply Maillefer) followed by apical instrumentation with K-type files #15, #20 and #25, and finishing with ProTaper F2 file (Denstply Maillefer). All files were used up to the working length under irrigation with 1 mL of 2.5% sodium hypochlorite (Biodyn$\hat{a}$mica) at each instrument change. At the end of instrumentation, the roots were randomly separated into 2 groups (n = 10). All specimens received final irrigation with 1 mL of 2.5% sodium hypochlorite. The solution remained in the root canals in Group 1 for one minute; and ultrasonic agitation was performed in Group 2 for one minute using a straight tip inserted at 1 mm from working length. The specimens were processed histologically and the sections were analyzed under optic microscope (x64) to quantify debris present in the root canal. Results: The samples submitted to ultrasonic agitation (Group 2) presented significant decrease in the amount of debris in comparison with those of Group 1 (p < 0.05). Conclusions: The hybrid instrumentation technique associated with passive ultrasonic agitation promoted greater debris removal in the apical third of the root canals.