• Journal of Bio-Environment Control
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• v.32 no.1
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• pp.72-80
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• 2023

Melons, a rich source of vitamins and fibers, are commonly grown in the soil. Hydroponic cultivation could improve yield and quality of melon and selection of substrate volume and the kind of substrates is important for hydroponic cultivation of melons. This study investigated the effect on melon growth according to volume of granular rockwool and substrates of coir and rockwool slab. 'Geumsegye' melon (Cucumis melo L. cv. Geumsegye) was cultivated hydroponically according to volume of granular rockwool to 1.0, 1.5, 2.0, 3.0, and 4.0 L, and was also cultivated using coir and rockwool slabs. Logistic model was applied to estimate the growth characteristics of melons such as plant height, leaf length, leaf width, and the characteristics of fruit. The growth characteristics of melons were significantly increased at 4.0 L compared to those grown of 1.0 L volume of on granular rockwool, and the results were the highest in coir and rockwool slabs. Melons grown in rockwool slabs showed the largest fruit fresh weight, fruit length, and fruit width. During hydroponic cultivation, growth characteristics of melon appropriate at the 4.0 L volume of granular rockwool, and the highest at coir and rockwool slabs. This study provides a basis for understanding the effect of root zone environment to the growth characteristics and fruit quality of non-netted melon.

• Korean Journal of Microbiology
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• v.27 no.1
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• pp.56-62
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• 1989

Antagonistic effects of Streptomyces species aganinst Fusarium solani causing ginseng root rot were investigated in terms of chitinase activity and growth inhibition in vitro. Among 131 isolates of streptomycetes obtained from ginseng cultivating soil, 9 isolates producing large clear zone around the colony on a chitin agar medium were selected for further study. All 9 isolates produced chitinase in a range from 0.10 to 0.38 U lysing cells of F. solani and inhibited germination of the conidia. In the ten-fold condentrated culture filtrate of S. alboniger ST59 and S. roseolilacinus ST129, the number of conidia of F. solane was reduced to about 20% of original count within 14 days. When S. alboniger ST59 and F. solani were grown simultaneously in the mineral saly medium, chitinase activity increased with incubation period, whereas mycelial volume of F. solani decreased. In a chitin added mineral salt medium, chitinase activity increased during the first four days and maintained steady level until the 8th day, and increased thereafter. S. alboniger ST59 lysed mycelia, conidia and even chlamydospores of F. solani. It is probable that the antagonistic activity of this streptomycete against F. solani is the lysis of fungal cell wall by streptomycete producing chitinase affected by antifungal substances.

• Restorative Dentistry and Endodontics
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• v.45 no.3
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• pp.30.1-30.11
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• 2020

Objectives: This micro-computed tomographic (CT) study aimed to compare the shaping abilities of ProTaper Next (PTN), One Shape (OS), and One Curve (OC) files in 3-dimensionally (3D)-printed mandibular molars. Materials and Methods: In order to ensure standardization, 3D-printed mandibular molars with a consistent mesiobuccal canal curvature (45°) were used in the present study (n = 18). Specimens were instrumented with the OC, OS, or PTN files. The teeth were scanned pre- and post-instrumentation using micro-CT to detect changes of the canal volume and surface area, as well as to quantify transportation of the canals after instrumentation. Two-way analysis of variance was used for statistical comparisons. Results: No statistically significant differences were found between the OC and OS groups in the changes of the canal volume and surface area before and after instrumentation (p > 0.05). The OC files showed significantly less transportation than the OS or PTN systems for the apical section (p < 0.05). In a comparison of the systems, similar values were found at the coronal and middle levels, without any significant differences (p > 0.05). Conclusions: These 3 instrumentation systems showed similar shaping abilities, although the OC file achieved a lesser extent of transportation in the apical zone than the OS and PTN files. All 3 file systems were confirmed to be safe for use in mandibular mesial canals.

• Korean Journal of Weed Science
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• v.8 no.3
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• pp.219-236
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• 1988

Bensulfuron concentrations of $10^{-7}$, $10^{-6}$, $10^{-5}$ and $10^{-4}M$ were applied to agar medium on susceptible (cv. KH 17854 and cv. IR 1846) and tolerant (cv. Chinsurah Boro II and IR 14252) rice cultivars were grown for microscopic inspection. Susceptible cultivars showed the decrease in shoot and root growth at the concentration of $10^{-5}M$ while ones showed no difference. Such a tendency was also observed from microscopic inspection in the elongation zone of shoot meristematic tissue. Seedlings grown in soil for 10 days were transfered to distilled water containing only bensulfuron solutions. There were significant differences between cultivars in terms of supression of shoot meristematic activity and swelling of cell volume. Observations of those cells made it clear that especially susceptible cultivars showed the irregular cell layering, vacuolation, cell swelling and partial damage in membrane of shoot tissue. The major response of root tips of susceptible cultivars showed the disorganization of cortex, rupture and contraction of membrane, inhibition of cell division, swelling and emergence of lateral root while tolerant ones showed no such responses.

• Journal of Korean Neurosurgical Society
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• v.40 no.3
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• pp.148-153
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• 2006

Objective : The authors conducted this study to present the long-term treatment outcomes [minimum 2 years] of Gamma knife radiosurgery[GKS] for trigeminal neuralgia[TN] and to demonstrate the correlation of treatment outcomes and the anatomical characteristics of TN. Methods : From 1997 to 2003, 44 consecutive patients suffering from medically intractable pain underwent GKS for TN. A single 4mm collimator was used with a median maximum dose of 80Gy [range $75{\sim}80Gy$] prescribed to the root entry zone of the trigeminal nerve. Median follow up duration was 30 months [range $24{\sim}78\;months$]. Anatomical measurements of trigeminal nerve in magnetic resonance images during GKS planning were correlated with clinical outcome. Results : Twenty-two patients [50%] achieved an excellent outcome [BNI grade I & II], 20 patients [45.5%] a good outcome [grade IIIa & IIIb], and only 2 patients [4.5%] a poor outcome [grade IV & V]. Eleven patients [25.0%] experienced pain recurrence after initial pain relief. Smaller volume of trigeminal nerve area irradiated more than 40Gy was significantly correlated with excellent outcome in both univariate and multivariate analyses respectively [P=0.033 and 0.040]. Conclusion : Anatomical considerations during the planning of GKS would be helpful for predicting clinical outcome in TN.

• Asian Journal of Turfgrass Science
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• v.25 no.1
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• pp.79-88
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• 2011

The purpose of this study was to obtain information on rates and salinity levels of irrigation for growth of Kentucky bluegrass by minimizing the hazard of salt accumulation in the sand based growing medium. Root zone profile consists of 20 cm sand based top soil, 20 cm of coarse sand as layer to interrupt capillary rise and 10 cm of reclaimed paddy soil as a base of the root zone profile. Topsoil was a mixture of dredged sand and peat with a ratio of 95%: 5% by volume. The columns were soaked into 5 cm depth saline water reservoir with salinity level of 3-5 $dSm^{-1}$. Salinity levels of irrigation water were 0, 2 and 3 $dSm^{-1}$. Irrigation rates were 3.8, 5.7 and 7.6 mm $day^{-1}$ which were equivalent to 70%, 100% and 130% of average ET (evapotranspiration) rate of Kentucky bluegrass, and irrigation interval was 3 days. Salt accumulation was due to irrigated water and moved up water from shallow water base. At the end of second year, the accumulation of salt in the rootzone showed ECc of3.86, 4.7 and 5.1 $dSm^{-1}$, and SAR of 19.2, 23.9 and 27.5 when the salinities were 0, 2 and 3 dS $m^{-1}$, respectively. Irrigation rates of 100% and 130% of ET rate with saline water did not decrease ECe and SAR in growing media. The growth of KEG was influenced by irrigation rate in the $1^{st}$ year, however, salinity level was more critical in the $2^{nd}$ year. Compared to non-saline water, saline water of 2 and 3 dS $m^{-1}$ resulted in decreased visual quality by 3.2% and 16.5%, by 6.4% and 39.3% in clipping weight, and by 5.5% and 5.0% in root mass, respectively.

• Asian Journal of Turfgrass Science
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• v.25 no.1
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• pp.106-111
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• 2011

This study was conducted to investigate the effect of the mixture ratio of a soldier fly casts (SFC), compost and cocopeat on the soil physicochemical properties. The mixture ratios of soil amendment were 0%, 3%, 5%, 7% and 10% (V/V) incorporated with sand which met to the USGA particle standard. To analyze the effects of amendments on soil chemical properties, pH and EC were measured. The porosity, capillary porosity, air-filled porosity, bulk density and hydraulic conductivity also measured to analyze the physical properties. Chemical properties were significantly different by mixture ratios of a SFC, compost and cocopeat. Capillary porosity was a factor involved in soil physical properties by blending with a SFC and compost. It was affected on the volume of porosity or hydraulic conductivity. To analyze the correlation of mixture ratio versus to physical characters, the ratios of SFC were significantly different in capillary porosity, air-filled porosity, and hydraulic conductivity. These results indicated that mixing ratios of SFC were affected on soil physicochemical properties such as porosity and hydraulic conductivity of the root zone on the USGA sand green.

• Asian Journal of Turfgrass Science
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• v.23 no.2
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• pp.271-278
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• 2009

This study was conducted to investigate the effect of the mixture ratio of the inorganic soil amendments on the soil physicochemical properties. In this experiment, three kinds of soil amendments which had similar pH, EC and particle size, the A, B and C, were tested. The mixture ratio of soil amendment were 0%, 3%, 5%, 7% and 10% (V/V) incorporated with sand which met to the USGA(United State of Golf Association) particle standard. To analyze the effects of amendment on chemical soil properties, pH, EC(electrical conductivity) and CEC(cation exchangeable capacity) were measured. The porosity, bulk density and hydraulic conductivity also measured to analyze the changes of physical properties. In the chemical properties, pH was significantly related to the mixture ratios of amendments, A and C(P<0.05), CEC and EC also related to the ratios of C(P<0.01). When the results were applied to the USGA standard of the soil physical properties, the optimum mixture ratios of each amendment were 3% in A and B, and 7~10% in C. To analyze the corelation of mixture ratio versus to physical character, volume of porosity was significantly related to the ratio of B (P<0.05), and showed similar corelation in porosity and hydraulic conductivity with ratio of C(P<0.05). These results indicate that types and mixture ratio of inorganic soil amendments should affect on soil physio-chemical properties of root zone on USGA sand green.

• Korean Journal of Environment and Ecology
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• v.34 no.3
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• pp.249-258
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• 2020

This study aims to provide reference material for effective forest management techniques at the catchment scale, based on the field investigation of large woody debris (LWD) in 11 streams within a third-order forest catchment in Gangwon Province, Korea. To achieve this aim, we analyzed the morphological features of LWD pieces, and the storage and distribution status of LWD by stream order throughout the entire investigation. As a result, a total of 1,207 individual pieces of LWD were categorized into three types as follows: (ⅰ) 1,142 pieces (95%) as only trunk and 65 pieces (5%) as a trunk with root wad, (ⅱ) 1,015 pieces (84%) as non-thinned and 192 pieces (16%) as the thinned, and (ⅲ) 1,050 pieces (87%) as conifer and 157 pieces (13%) as broadleaf. Additionally, in-stream LWD loads (㎥/ha) decreased with increasing stream order, yielding 105.4, 71.3, and 35.6 for first-, second-, and third-order streams, respectively. On the other hand, the ratio of LWD jams to the total LWD volume increased with increasing stream order, yielding 11%, 43%, and 49% for first-, second-, and third-order streams, respectively. Finally, a comparison of the in-stream LWD load with previous studies in several countries around the world indicated that in-stream LWD load was positively correlated with forest stand age even though the climate, topography, forest soil type, forest composition, stand growth rate, disturbance regime, and forest management practices were different. These results could contribute to understanding the significance of LWD as a by-product of forest ecosystems and an indicator of riparian forest disturbance. Based on this, we conclude that advanced forest management techniques, including treatment of thinning slash and stand density control of riparian forest by site location (hillslope and riparian zone, or stream order), should be established in the future, taking the forest ecosystem and the aquatic environment from headwater streams to low land rivers into consideration.

• Journal of Bio-Environment Control
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• v.23 no.2
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• pp.139-143
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• 2014

This study was conducted to investigate the effect of cultivation period and rockwool block size on the growth and early yield of paprika transplants grown in a closed transplant production system. Paprika seeds were sown and germinated in three different size of rockwool blocks ($45{\times}40{\times}35$, $70{\times}70{\times}60$, $100{\times}100{\times}65mm$) and cultivated in a closed transplant production system for 23, 30, and 37 days after sowing. Paprika transplants were cultivated using $100{\times}100{\times}65mm$ rockwool blocks in a greenhouse following a conventional and typical production method for comparing with the growth of paprika transplants grown in a closed transplant production system. Also, we transplanted paprika transplants grown for 23, 30, and 37 days in a closed transplant production system and greenhouse to rockwool slabs and investigated fresh weight of fruits and yield 125 days after sowing. The growth of paprika transplants grown in $70{\times}70{\times}60mm$ rockwool blocks in a closed transplant production system was highest, and the quality of paprika transplant grown in a closed transplant production system was better than in a greenhouse. Rockwool block size and cultivation period in a closed transplant production system did not affect fresh weight of fruits, however, yield was largest when paprika transplants were cultivated using $70{\times}70{\times}60$ and $100{\times}100{\times}65mm$ rockwool blocks for 23 days in a closed transplant production system. These results suggest that decreasing rockwool block size and cultivation period can be strategically used to enhance transplant quality and yield of paprika, as paprika transplants were cultivated in a closed transplant production system.