• Proceedings of the Korea Water Resources Association Conference
• /
• 2023.05a
• /
• pp.30-30
• /
• 2023

This study aims to establish the multi-reservoir operation system model in the Upper Mun River Basin which includes 5 main dams namely, Mun Bon (MB), Lamchae (LC), Lam Takhong (LTK), Lam Phraphoeng (LPP), and Lower Lam Chiengkrai (LLCK) Dams. The knowledge and AI technology were applied aiming to develop innovative prototype for SMART dam-reservoir operation in future. Two different sorts of reservoir operation system model namely, Fuzzy Logic (FL) and Constraint Programming (CP) as well as the development of rainfall and reservoir inflow prediction models using Machine Learning (ML) technique were made to help specify the right amount of daily reservoir releases for the Royal Irrigation Department (RID). The model could also provide the essential information particularly for the Office of National Water Resource of Thailand (ONWR) to determine the short-term and long-term water resource management plan and strengthen water security against flood and drought in this region. The simulated results of base case scenario for reservoir operation in the Upper Mun from 2008 to 2021 indicated that in the same circumstances, FL and CP models could specify the new release schemes to increase the reservoir water storages at the beginning of dry season of approximately 125.25 and 142.20 MCM per year. This means that supplying the agricultural water to farmers in dry season could be well managed. In other words, water scarcity problem could substantially be moderated at some extent in case of incapability to control the expansion of cultivated area size properly. Moreover, using AI technology to determine the new reservoir release schemes plays important role in reducing the actual volume of water shortfall in the basin although the drought situation at LTK and LLCK Dams were still existed in some periods of time. Meanwhile, considering the predicted inflow and hydrologic factors downstream of 5 main dams by FL model and minimizing the flood volume by CP model could ensure that flood risk was considerably minimized as a result of new release schemes.

• Korean Journal of Environmental Agriculture
• /
• v.41 no.4
• /
• pp.282-287
• /
• 2022

BACKGROUND: Green algae (Chlorella spp.) has been widely used as a biofertilizer to improve the crop yield and quality. However, available information is not enough to verify the mechanism of green algae's beneficial impact on strawberry. This study was conducted to investigate the effect of Chlorella fusca CHK005 application on the growth and nutrient status of strawberry plant and fruit characteristics. METHODS AND RESULTS: A total of 800 seedlings of strawberry variety 'Kuemsil' were planted. Once a week, C. fusca culture solution (1.0 × 10⁷ cells mL^-1) was applied into soil via irrigation in four different concentrations: no application (control), 1/1000 times (× 0.5), 1/500 times (× 1), and 1/250 times (× 2). Result showed that growth of strawberry plant was enhanced by Chlorella application and the highest impact on fresh weight (FW) and chlorophyll content of the plants were observed in × 2 treatment, followed by × 1, × 0.5, and control treatments. The phosphorus (P) concentration in the plant was significantly higher in × 1 and × 2 treatments compared to control. In case of fruit quality, sugar content (°Brix), hardness, and FW were lowest in control, but these values increased as application levels of Chlorella were higher. Also, P and K contents in the fruits increased with increasing the application levels and significant correlation between P content and oBrix in the fruits was found. CONCLUSION(S): Overall, Chlorella application seemed to improve plant growth and fruit quality by increasing the utilization efficiency of P and K in strawberries.

• Korean Journal of Environmental Biology
• /
• v.41 no.4
• /
• pp.463-472
• /
• 2023

The insecticidal activities of 27 different commercial products with environmentally friendly organic material(EFOM) against Scotinophara lurida, a major rice pest, were evaluated in the laboratory using spraying methods on plants and insects. Seven plant-derived organic farming materials (EFOM-8, -10, -12, -13, -19, -20, and -26) with high insecticidal effects when sprayed directly on the insect's body rather than on the plant were selected. In the indoor rice pot test, all 7 EFOMs showed an insecticidal rate of over 73.3% under flooding conditions. Notably, EFOM-13 and EFOM-20 demonstrated much higher insecticidal rates, ranging from 1.5 to 1.8 times, in flooding conditions compared to drained conditions. In the semi-paddy field test, EFOM-10 (80% garlic extract), EFOM-13 (62% neem extract), and EFOM-26 (70% sophora extract+28% ethyl alcohol+2% pyrethrum extract) exhibited a higher control value of 88.9% in the irrigated paddy on the 7th day, surpassing the control values in the drained paddy by 1.4 to 1.9 times. The control value in the irrigated rice paddy field sprayed with EFOM-10 reached 86.2% on the 7th day, which was 1.4 times higher than 61.9% in the drained paddy. Taken together, the findings suggest that direct contact of the insect's body with sufficient amounts of spray solution and the maintenance of paddy irrigation can enhance the controlling effect of EFOMs. These findings will be valuable in developing an optimal S. lurida control strategy for application in rice paddy fields in the near future.

• Restorative Dentistry and Endodontics
• /
• v.24 no.1
• /
• pp.166-179
• /
• 1999

Apical sealing is essential for the success of surgical endodontic treatment. Root-end cavity is apt to be contaminated with moisture or blood, and is not always easy to be dried completely. The purpose of this study was to evaluate the influence of dry methods of retrocavity on the apical seal in endodontic surgery. Apical seal was investigated through the evaluation of apical leakage and adaptation of filling material over the cavity wall. To investigate the influence of various dry methods on the apical leakage, 125 palatal roots of extracted human maxillary molar teeth were used. The clinical crown of each tooth was removed at 10 mm from the root apex using a slow-speed diamond saw and water spray. Root canals of the all the specimens were prepared with step-back technique and filled with gutta-percha by lateral condensation method. After removing of the coronal 2 mm of filling material, the access cavities were closed with Cavit$^{(R)}$. Two coats of nail polish were applied to the external surface of each root. Apical three millimeters of each root was resected perpendicular to the long axis of the root with a diamond saw. Class I retrograde cavities were prepared with ultrasonic instruments. Retrocavities were washed with physiologic saline solution and dried with various methods or contaminated with human blood. Retrocavities were filled either with IRM, Super EBA or composite resin. All the specimens were immersed in 2% methylene blue solution for 7 days in an incubator at $37^{\circ}C$. The teeth were dissolved in 14 ml of 35% nitric acid solution and the dye present within the root canal system was returned to solution. The leakage of dye was quantitatively measured via spectrophotometric method. The obtained data were analysed statistically using one-way ANOVA and Duncan's Multiple Range Test. To evaluate the influence of various dry methods on the adaptation of filling material over the cavity wall, 12 palatal roots of extracted human maxillary molar teeth were used. After all the roots were prepared and filled, and retrograde cavities were made and filled as above, roots were sectioned longitudinally. Filling-dentin interface of cut surfaces were examined by scanning electron microscope. The results were as follows: 1. Cavities dried with paper point or compressed air showed less leakage than those dried with cotton pellet in Super EBA filled cavity (p<0.05). However, there was no difference between paper point- and compressed air-dried cavities. 2. When cavities were dried with compressed air, dentin-bonded composite resin-filled cavities showed less apical leakage than IRM- or Super EBA-filled ones (p<0.05). 3. Regardless of the filling material, cavities contaminated with human blood showed significantly more apical leakage than those dried with compressed air after saline irrigation (p<0.05). 4. Outer half of the cavity showed larger dentin-filling interface gap than inner half did when cavities were filled with IRM or Super EBA. 5. In all the filling material groups, cavities contaminated with blood or dried with cotton pellets only showed larger defects at the base of the cavity than ones dried with paper points or compressed air.

• Journal of Bio-Environment Control
• /
• v.22 no.4
• /
• pp.408-412
• /
• 2013

This study was carried out to investigate damp injury caused by tomato coir bag culture and prevent that. The tomato variety was used 'Minichal', and tomatoes were grown in greenhouse. The nutrient solution based on Yamazaki Tomato Standard Solution was irrigated from one hour after sunrise to two hour before sunset. The slits for darainage were made in three types; I, L, and bottom slit type. The coir bag of I and L type had six slits of 15cm length, that of bottom slit type had three slits of 15 cm length. The weight of coir bag in 24 hours after saturation was 14.2 kg in I type, 13.8 kg in L type, and 12.8 kg in bottom slit type, but there was not significant difference. The weight of coir bag after one day irrigation was 14.5 kg, 14.2 kg, and 13.3 kg at L, I, and bottm slit type, respectively. This means that the moisture content of coir bag during cultivation was lowest in bottom slit type. The number of adventitious root on stem was 160, 170, and 53 at I, L, and bottom slit type, respectively. The dry weight of root and root length were highest at bottom slit type, compared to other treatment. The marketable yield was highest 26.5 kg/20 plant in bottom slit type. For increasing yield and preventing damp injury, bottom slit type was most effective at U type bed coir bag culture.

• Restorative Dentistry and Endodontics
• /
• v.32 no.2
• /
• pp.121-129
• /
• 2007

The purpose of this study was to assess the antibacterial effect of sodium dichloroisocyanurate (NaDCC), sodium hypochlorite (NaOCl), and chlorhexidine (CHX) on Enterococcus faecalis and to evaluate and to compare the time-dependant antimicrobial effect of NaDCC with NaOCl and CHX in the root canal in vitro before and after instrumentation. Extracted Human single teeth were prepared by serial instrumentation technique. The samples were autoclaved and contaminated for 3 days with E. faecalis monocultures. The teeth were then divided into 4 groups Each group was irrigated and inserted with 2% NaOCl, 2% NaDCC, 2% CHX and steri)ized saline. After 6, 12, 24, 72h, and 1 week incubation, sterilized paper point was inserted into the root canal. Paper points containing root canal contents were then placed on the agar plate. And then each root cana) was prepared with #4 and #5 GG (Gates-Glidden) drill. The debris were collected in the sterilized microtube and the plates were incubated at $37^{\circ}C$ in an increased $CO_2$ atmosphere. After 24h incubation the growth of bacteria around the paper points were measured. NaOCl and NaDCC solution shows similar antimicrobial effect for E. faecalis at 6, 12, 24, 72h and 1 week. In centrol group, irrigated with sterilized saline, no antimicrobial effect was observed. The results are in agreement with other investigators, who have shown the bactericidal property and possibility of NaDCC as a root canal irrigation solution. Thus it seems that NaDCC solutions can be clinically applied into the root canal within 1 week after dilution.

• Journal of Bio-Environment Control
• /
• v.31 no.4
• /
• pp.409-415
• /
• 2022

Plant growth and development are also affected by root-zone environment. Therefore, it is important to consider the variables of the root-zone environment when establishing an irrigation strategy. The purpose of this study is to analyze the relationship between the volumetric moisture content (VWC), Bulk EC (ECb), and Pore EC (ECp) used by plant roots using FDR sensors in two types of rockwool media with different water transmission characteristics, using the method above this was used to establish a method for collecting and correcting available root-zone environmental data. For the experiment, two types of rockwool medium (RW1, RW2) with different physical characteristics were used. The moisture content (MC) and ECb were measured using an FDR sensor, ECp was measured after extracting the residual nutrient solution from the medium using a disposable syringe in the center of the medium at a volumetric moisture content (VWC) of 10-100%. Then, ECb and ECp are measured by supplying nutrient solution having different concentration (distilled water, 0.5-5.0) to two types of media (RW1, RW2) in each volume water content range (0 to 100%). The relationship between ECb and ECp in RW1 and RW2 media is best suited for cubic polynomial. The relationship between ECb and ECp according to volume moisture content (VWC) range showed a large error rate in the low volume moisture content (VWC) range of 10-60%. The correlation between the sensor measured value (ECb) and the ECp used by plant roots according to the volumetric water content (VWC) range was the most suitable for the Paraboloid equation in both media (RW1, RW2). The coefficient of determination the calibration equation for RW1 and RW2 media were 0.936, 0.947, respectively.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.38 no.2
• /
• pp.129-136
• /
• 2011

Microorganisms are the main causative factors of pulpal and periapical diseases, therefore successful endodontic treatment is depend on the effective elimination of intracanal bacterial populations. Many studies have been reported antimicrobial effect of Allyl isothiocyanate (AIT) which the principle ingredient of Horseradish (Armoracia rusticana) root extracts. The purposes of this study are to evaluate the antimicrobial effectiveness of Horseradish root extracts against Enterococcus faecalis in root canals of extracted human teeth and compare to sodium hypochlorite (NaOCl). Extracted human mandibular premolar root canals were infected with E. faecalis for 21 days, and then irrigated with Horseradish root extracts, NaOCl solution and saline. After canal irrigation, first samples (S1) were taken. After first sampling, the canals were additionally incubated 7 days, and then second samples (S2) were taken. The samples were inoculated on EHI agar plate to determine the colony forming units (CFU). 1. Mean values of CFU in S1 were $5.815{\times}10^3$ CFU/ml at Horseradish groups, and $3.465{\times}10^3$ CFU/ml at NaOCI groups. There was no statistically significant differences (p=0.086). 2. Mean values of CFU in S2 were $3.100{\times}10^3$ CFU/ml at Horseradish groups, and $5.252{\times}10^5$ CFU/ml at NaOCI groups. There was statistically significant difference (p<.05). 3. There was no statistically significant differences (p=0.076) between S1 and S2 at Horseradish groups in the mean values of CFU. However, there was statistically significant differences (p<.05) between S1 and S2 at NaOCI groups in the mean values of CFU.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.29 no.1
• /
• pp.37-44
• /
• 2013

Sodium hypochlorite and ethylene diamine tetra acetic acid are substances usually used during endodontic treatment. Several studies found that the bonding was negated with certain irrigants and some of the used irrigants have demineralizing and chealating effects, so it was advocated to omit the etching step in etch and rinse adhesive systems. The purpose of this in vitro study was to evaluate the influence of NaOCl & EDTA on the bonding strength of ethanol wet bonding. Thirty human molars were selected and mesiodistally sectioned into halves, thus providing sixty specimens. The specimens were randomly assigned to 4 groups(n=15) according to the irrigant regimen used : (1) irrigated with distilled water for 10min (control); (2) irrigated with 5.25% NaOCl(10min), flushed with 5.25% NaOCl(1min) (3) irrigated with 5.25% NaOCl, flushed with 17% EDTA (4) irrigated with 5.25% NaOCl, flushed with 17% EDTA. Each group was acid-etched with 37% phosphoric acid(except group 4) and had their dentin surfaces dehydrated with ethanol solutions : 50%, 70%, 80%, 95%, 3x100%, 30s for each application. After dehydration, a primer( 50% all bond 3 resin + 50% ethanol) was used, followed by the adhesive(ALL-BOND 3 RESIN) application. Resin composite build-ups were then prepared using an incremental technique. Specimens were sectioned into beams and submitted to a tensile load using a Micro Tensile Tester(Bisco Inc.). The data were statistically analyzed using one-way ANOVA and Tukey HSD at p<0.5 level. There was no significant difference on G1(control) and G2(irrigated with NaOCl only ). (p>0.05). G3(flushed with EDTA) showed significantly high tensile bonding strength compared to the G2 (p<0.05). G4( treated with EDTA but no acid-etching) was significantly lower value than G3. (p<0.05) Although there was no significant difference, 5.25% NaOCl seemed to have an adverse effect on the bonding strength of ethanol wet bonding. The flushing with EDTA after NaOCl irrigation prevents the decrease of bonding strength. The use of 17% EDTA as a final flush can enhance the bonding strength but EDTA flushing can't substitute for a acid-etching.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.37 no.5
• /
• pp.468-475
• /
• 1992

In order to understand more clearly the integration between N-assmilation and C-metabolism in relation to N fertilization, a pot experiment with 5 different level of N fertilization(0, 5, 10, 25, 50 mM NO$_3$$_{[-10]}$ ) was conducted in Manchester, U.K. The peas (Pisum sativum L., cv. Early Onward) were sown in vermiculate (5 cm depth) and cultivated for 6 days under temperature controlled dark room conditions ($25^{\circ}C$). The plants received frequent irrigation with a nutrient solution: it was fertilized every 2 days, 3 times a day at 10h, 13h, 16h respectively. Elevated NO$_3$$^{[-10]}$ concentration, the activity levels of NR, NiR, total GS(crude extract), GS$_2$(plastid) in both root and shoot were increased and reached the peak in 5～25 mM, except NiR specific activity which increased its activity continually until 50 mM NO$_3$$^{[-10]}$ treatment. Total activities of GS (crude extract) in both root and shoot became higher than those of GS$_2$(Plastid), and the activity ratios of total GS in the crude extract and GS$_2$ in the plastids were 3.0 to 4.3 in root, but 3.2 to 10.6 in shoot. It was concluded that the reductants and A TP from OPPP itself should be enough to achieve the high rate of NR, NiR, GS$_1$, GS$_2$ in plant root and shoot for reduction or assimilation of nitrogen, but these enzyme activities might be inhibited by an excess of NO$_3$$^{[-10]}$ influx over the reduction capacity.