• Korean journal of applied entomology
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• v.53 no.1
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• pp.51-57
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• 2014

We identified the five root-lesion nematode species, Pratylenchus crenatus, P. fallax, P. kumamotoensis, P. panamaensis and P. penetrans from intercepted in quarantine inspection over the past five years. Their diagnostic characters are including number of lip annuli, stylet length, shape of the labial region, presence or absence of males, structure of lateral fields, shape of spermatheca, length of the post-vulval uterine sac and shape of tail and so forth. We described the photos, measurements and morphological characters.

• Journal of The Korean Society of Grassland and Forage Science
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• v.23 no.2
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• pp.91-94
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• 2003

Rhizotron technique was used to determine the zone of active root growth in contrasting field situations. The distribution of roots with depth showed most root in the 15∼30 cm layer with fewer in the 0∼15 cm and below 30 cm layer at Lincoln Farm, while root density increased with depth at Winchmore. At Mt Johm (Lake Tekapo) roots were more distributed near soil surface. Root density was increased with fertilizer and irrigation at Mt John. Root number showed the same trends as root length at all lesions. Tube method was good for comparative purposes, and for long-term root growth studies at the same place.

• Journal of the korean academy of Pediatric Dentistry
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• v.47 no.1
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• pp.25-35
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• 2020

The purpose of this study is to evaluate the morphological characteristics of the roots and roots canals of primary molar teeth using Cone-Beam Computed Tomography (CBCT). A total of 68 CBCT images of children aged 4 - 5 years was used for this study. A total of 160 molar teeth were analyzed. Various parameters such as the number of roots and canals, length of root and root canal, and the angulation and shape of the roots were analyzed. All maxillary primary molars had 3 roots. The presence of 2 root canals in 1 root was only observed in the mesiobuccal root of maxillary primary second molars. Most mandibular primary molars had 2 roots, and most mesial roots had 2 root canals. Concerning the length of the roots, the palatal root of the maxillary primary molar was found to be longest whereas the distobuccal root was shortest. In mandibular primary molars, the mesial root was longer than the distal root. In maxillary primary molars, the palatal root had the greatest angulation whereas the distal root has the greatest in mandibular molars. The root and root canals of maxillary primary molars were more curved in shape whereas mandibular primary molars were straight.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.222-222
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• 2017

This study aimed to determine an optimal temperature of root zone for the chive cultivation in a greenhouse during the winter season that may raise the possibility of chive (Allium schoenoprasum L.) harvest any time year-round by reducing energy consumption. The maximum and minimum temperatures of root zone were 26.8 and $19.8^{\circ}C$ for the R-Z20, 28.3 and $23.6^{\circ}C$ for the R-Z25 and 22.4 and $14.3^{\circ}C$ for the control. The highest fresh weights of shoot and root, plant height, root length and stem diameter were observed in the R-Z20 treatment. There was no significant difference in the growth between the R-Z25 and control treatment. These results suggest that the optimal temperature of root zone is $20^{\circ}C$ for the chive cultivation in the greenhouse during winter season.

• Journal of Environmental Science International
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• v.12 no.6
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• pp.659-664
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• 2003

The experiment was carried out to investigate the effects of sulfuric acid and nitric acid among the main components of simulated acid rain (SAR) on the growth of vegetative organs and seed germination of Arabidopsis thaliana. The Arabidopsis treated with SAR supplemented with sulfuric and nitric acids, respectively, showed 28% and 30% decrease of shoot and root growth compared to the control plants, and also many necrotic spots on leaf surfaces after SAR treatment were observed. The shoot and root length for plants grown with nitric acid rain was 14% and 17% lower, respectively, compared to the control, whereas those grown with sulfuric acid rain was 24% and 25% lower than control plants. When Arabidopsis seeds were sown in distilled water, germination rate was 100% after 7 days. However, 80% in SAR medium supplemented with sulfuric and nitric acids, 88% in sulfuric acid rain medium and 93% in nitric acid rain medium. The germination abilities of seeds harvested from SAR supplemented with sulfuric and nitric acids, sulfuric acid rain, and nitric acid rain were 73%, 73% and 94%, respectively. Consequently, sulfuric acids showed more inhibitory effects than nitric acids on the growth of vegetative organs as well as germination rates in Arabidopsis.

• Korean Journal of Agricultural Science
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• v.44 no.2
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• pp.196-210
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• 2017

The synergistic effect on phosphate solubilization of single- and co-inoculation of two phosphate solubilizing bacteria, Burkholderia cepacia (C1) and Alcaligenes aquatilis (H6), was assessed in liquid medium and maize plants. Co-inoculation of two strains was found to release the highest content of soluble phosphorus (309.66 ?g/mL) into the medium, followed by single inoculation of B. cepacia (305.49 ?g/mL) and A. aquatilis strain (282.38 ?g/mL). Based on a plant growth promotion bioassay, co-inoculated maize seedlings showed significant increases in shoot height (75%), shoot fresh weight (93.10%), shoot dry weight (84.99%), root maximum length (55.95%), root fresh weight (66.66%), root dry weight (275%), and maximum leaf length (81.53%), compared to the uninoculated control. In a field experiment, co-inoculated maize seedlings showed significant increases in cob length (136.92%), number of grain/cob (46.68%), and grain weight (67.46%) over control. In addition, single inoculation of maize seedlings also showed improved result over control. However, there was no significant difference between single inoculation of either bacterial strains and co-inoculation of these two bacterial strains in terms of phosphate solubilization index, phosphorous release, pH of the media, and plant growth parameters. Thus, single inoculation and co-inoculation of these bacteria could be used as biofertilizer for improving maize growth and yield.

• Korean Journal of Environmental Agriculture
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• v.29 no.4
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• pp.408-416
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• 2010

To evaluate the effectiveness of AMF on the growth of horticultural crops, we compared mycorrhizal and non-mycorrhizal plants, perilla (P. frutescens Britt.), that were inoculated with AMF propagules. In the early stages of growth of perilla, compared to the AMF- perilla seedlings, in AMF+ perilla seedlings at 3 weeks after sowing, leaf length and width increased 17% and 29%, leaf area increased 28%, and shoot fresh weight increased 33%, root total length increased 1%, and chlorophyll content increased 3%. Further at 10 weeks after sowing, compared to the AMF- perilla plants, in perilla plants inoculated with AMF at the sowing and transplanting stages, leaf area increased 21% and 19%, shoot length increased 19% and 17%, root fresh weight increased 17% and 20%, and chlorophyll content increased 5.1% and 4.8%, respectively. Moreover, at 14 weeks after sowing, compared to the AMFperilla plants, in perilla plants inoculated with AMF at the sowing and transplanting stages, the number of leaves increased 16% and 20%, root fresh weight increased 16% and 17% significantly. Further, leaf fresh weight increased 9% and 11%, shoot diameter increased 4.5% and 7.3%, and chlorophyll content increased 1.5% and 2.5%, respectively. The levels of many macronutrients and micronutrients were tended to be significantly higher in AMF+ plants than in AMF- plants, supporting the association between AMF and enhanced growth of plants grown from AMF+ seedlings.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.37 no.10
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• pp.694-701
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• 1988

Distributed-type railguns are designed to maintain the armature current and the length between the armature and the current-feed region nearly constant with time. This paper deals with factors affecting current distribution, effective resistance and effective skin depth in the rail of a distributed-type railgun. Analytical solutions for the current distributions and resistance in the rail are presented for a simple two-dimensional model under steady-state contions. For diffusion limited current, it is found that effective rail resistance is proportional to the square root of the relative velocity, the permeability of the rail and the length between the armature and that effective skin depth of the rail is proportional to the square root of the length and inversely proportional to the square root of the permeability, the conductivity and the velocity.

• Imaging Science in Dentistry
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• v.36 no.1
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• pp.55-62
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• 2006

Purpose : To find the cause of root curvature by use of panoramic and lateral cephalometric radiograph. Materials and Methods : Twenty six 1st graders whose mandibular 1st molars .just emerged into the mouth were selected. Panoramic and lateral cephalometric radiograph were taken at grade 1 and 6, longitudinally. In cephalometric radio graph, mandibular plane angle, ramus-occlusal plane angle, gonial angle, and gonion-gnathion distance (Go-Gn distance) were measured. In panoramic radio graph, elongated root length and root angle were measured by means of digital subtraction radiography. Occlusal plane-tooth axis angle was measured, too. Pearson correlations were used to evaluate the relationships between root curvature and elongated length and longitudinal variations of all variables. Multiple regression equation using related variables was computed. Results : The Pearson correlation coefficient between curved angle and longitudinal variations of occlusal plane-tooth axis angle and ramus-occlusal plane angle was 0.350 and 0.401, respectively (p<0.05). There was no significant correlation between elongated root length and longitudinal variations of all variables. The resulting regression equation was $Y=10.209+0.208X_1+0.745X_2$ (Y: root angle, $X_1$: variation of occlusal plane-tooth axis angle, $X_2$: variation of ramus-occlusal plane angle). Conclusion : It was suspected that the reasons of root curvature were change of tooth axis caused by contact with 2nd deciduous tooth and amount of mesial and superior movement related to change of occlusal plane.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.6
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• pp.539-543
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• 2006

Lodging is classified as root lodging caused by the loss of supporting force in the root, bending caused by the deformation of the stem and breaking where the stem breaks down as loads exceeding critical elasticity were applied. This research excluded breaking which is not in a state of equilibrium and tried to partition the level of lodging using an algebraic model in root lodging and stem lodging, or bending. When a vertical load was applied, the deformation of the stem of rice plant showed the form of a quadratic equation. The trace of the panicle neck in the process of lodging was an ellipse-shape. When loading was pure root lodging, the trace of the panicle neck became a circle of which culm length is the radius. When it was a pure stem lodging, the trace of the panicle neck is an ellipse of which major axis is culm length and minor axis is 0.64* culm length. When both stem lodging and root lodging occurred in a natural setting, the partitioning of lodging can be calculated by a formula using eccentricity of an ellipse, S=e*100/0.768(S is the ratio of stem lodging in the whole lodging, e is eccentricity of the ellipse). This method is expected to be useful in simple lodging partitioning. We could also calculate the partitioning of stem lodging and root lodging as units of angles as an accuracy method, by using a straight line calculated by differentiating a quadratic equation of stem deformation at the origin of the coordinates. These two methods for dividing root and stem lodging showed different values. However, each of them showed almost same values with different lodging degree in one plant.