• Journal of the korean academy of Pediatric Dentistry
• /
• v.45 no.3
• /
• pp.334-343
• /
• 2018

The purpose of this study was to investigate the cause of eruption disturbance in the maxillary central incisor and establish the effective treatment plan by analyzing the vertical distance, angulation of long axis and root development of the tooth with eruption disturbance using the cone-beam CT. The average age of 134 patients diagnosed with unilaterally impacted maxillary central incisor was 7.9 years old and the male was 2.1 times higher than the female. The most common cause of eruption disorder was physical obstruction, especially mesiodens and odontoma. Of the teeth with unilateral eruption disorder, 78 cases erupted spontaneously and 56 cases erupted non-spontaneously after removal of physical obstruction. The possibility of spontaneous or non-spontaneous eruption in the unilaterally impacted maxillary central incisor depended on several factors, such as vertical distance, angulation of long axis and root development of unerupted tooth. The spontaneous eruption of the impacted maxillary cental incisor was most frequent at the angulation of long axis of 50 to 90 degrees, which is similar to the angulation of long axis of the normally erupted maxillary central incisor. In addition, the spontaneous eruption period of impacted maxillary central incisor was more influenced by the vertical distance than the angulation of long axis and the root development. Most of the teeth that showed non-spontaneous eruption had orthodontic traction, and these teeth were usually erupted within about 12 months. The period treated with orthodontic traction was no statistical significance with the vertical distance, the angulation of long axis, and the root development. This study will provide information on the cause of unilaterally impacted maxillary cental incisor and help to establish the future treatment plan.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.36 no.3
• /
• pp.297-304
• /
• 2012

For the assessment of the performance of a wind-turbine blade, a simulated loading test may be required. In this study, the blade behavior was investigated through numerical analysis using a dual-axis loading test, closely simulating the real operation conditions. The blade structure for the 100-kW-class wind-turbine system was modeled using the finite element (FE) program ANSYS. The failure criteria and buckling analysis under dual-axis loading were examined. The failure analysis, including fiber failure and inter-fiber failure, was performed with Puck's failure criterion. As the dual-axis load ratio increases, the relatively increased stress occurs at the trailing edge and skin surface 3300-3600 mm away from the root. Furthermore, it is revealed that increasing the dual-axis load ratio makes the location that is weakest against buckling move toward the root part. Thus, it is seen that the dual-axis load test may be an essential requirement for the verification of blade performance.

• Korean Journal of Food Science and Technology
• /
• v.9 no.1
• /
• pp.19-23
• /
• 1977

The variation of the amount of starch, size and shape of the starch granules, amylose content, and blue value of the starch in the Korean ginseng roots from one year old to five year old cultivated at Kumsan was studied. The results obtained were as follows; 1) The starch content of the ginseng root(dried) was increased with the age of the root; that is, 9.62% for one-year-old roots, 10.35% for two-year-old root, 15.50% for three-year-old root, 17.05% for four-year-old root, and 18.32% for five-year-old root. 2) The shape of the ginseng starch granules was round or short oval, and in the latter case the ratio of minor axis to major axis was 1 to 1.1. Diameter of the starch granules was in the range of $1.48\;{\mu}\;to\;8.14\;{\mu}$ and the most frequent granule size was $3\;{\mu}\;(32.1{\sim}35.7%)$. The number of big size starch granules was increased during the five years of growing, while, the number of small size granules was decreased. 3) The amylose content in the ginseng starch was varied with the age of the root, in the range of $53.6{\sim}70.5%$. 4. The blue value of the ginseng starch was in the range of 0.60 to 0.71.

• Korean Journal of Materials Research
• /
• v.26 no.12
• /
• pp.676-680
• /
• 2016

We have investigated the properties of thin film transistors(TFT) fabricated using zinc tin oxide(ZTO) thin films deposited via on-axis sputtering and FTS methods. ZTO thin films deposited by FTS showed lower root-mean-square(RMS) roughness and more uniformity than those deposited via on-axis sputtering. We observed enhanced electrical properties of ZTO TFT deposited via FTS. The ZTO films were deposited at room temperature via on-axis sputtering and FTS. The as-deposited ZTO films were annealed at $400^{\circ}C$. The TFT using the ZTO films deposited via FTS process exhibited a high mobility of $12.91cm^2/V.s$, a low swing of 0.80 V/decade, $V_{th}$ of 5.78 V, and a high $I_{on/off}$ ratio of $2.52{\times}10^6$.

• Proceedings of the Korean Society for Agricultural Machinery Conference
• /
• 2001.02a
• /
• pp.16-21
• /
• 2001

The ride quality of agricultural tractor seats is evaluated based on the vibration of the human bodies. Tractor ride vibration levels have been measured at the person-seat interface along 7 axes(3 translational axes at the feet, 3 translational axes on a seat surface and 1 axis at the seat back), under different operating conditions. Since one of the most important parameters for ride comfort is the level and duration of the root mean square acceleration experienced, the ride values, such as the seat effective amplitude transmissibility, the component ride value, and the overall ride value based on acceleration root mean square are evaluated for a conventional tractor using frequency weighting functions and axis multiplying factors. The ride indices are also studied considering to the variation of vehicle speed and road profile.

• Bulletin of the Korean Mathematical Society
• /
• v.53 no.1
• /
• pp.21-28
• /
• 2016

It is known that no two of the roots of the polynomial equation (1) $$\prod\limits_{l=1}^{n}(x-r_l)+\prod\limits_{l=1}^{n}(x+r_l)=0$$, where 0 < $r_1{\leq}r_2{\leq}{\cdots}{\leq}r_n$, can be equal and all of its roots lie on the imaginary axis. In this paper we show that for 0 < h < $r_k$, the roots of $$(x-r_k+h)\prod\limits_{{l=1}\\{l{\neq}k}}^{n}(x-r_l)+(x+r_k-h)\prod\limits_{{l=1}\\{l{\neq}k}}^{n}(x+r_l)=0$$ and the roots of (1) in the upper half-plane lie alternatively on the imaginary axis.

• Wind and Structures
• /
• v.16 no.3
• /
• pp.241-248
• /
• 2013

The wind turbine blade is a very important part of the rotor. Extraction of energy from wind depends on the design of blade. In this work, the analysis is done on a blade of length 38.95 m which is designed for V82-1.65 MW horizontal axis wind turbine (supplied by Vestas). The airfoil taken for the blade is NACA 634-221 which is same from root to tip. The analysis of designed blade is done in flap-wise loading. Two shapes of the spar are taken, one of them is of square shape and the other one is combination of square and cross shape. The blade and spar are of the same composite material. The Finite element analysis of designed blade is done in ANSYS. This work is focused on the two segments of blade, root segment and transition segment. Result obtained from ANSYS is compared with the experimental work.

• Applied Microscopy
• /
• v.15 no.2
• /
• pp.69-79
• /
• 1985

Ultrastructural and cytochemical studies of the root hair cell and the trichoblast were undertaken with light and electron microscopes to clarify the type of root hair, fine structure and the activities of acid phosphatase and ATPase. The root hair was differentiated from the middle portion of the cell, and perpendicularly to the long axis of the cell. Consequently, the type of root hair comes under the panicoid type. In the trichoblast, nucleus and cytoplasm are located in the vicinity of cortex. On the contrary, after the root hair is formed, they migrate to the apical region of the root hair, and the basal region of the root hair is filled with numerous vacuoles. Cell walls of actively growing root hairs are subdivided into two layers on the basis of the arrangement of cellulose microfibrils. New cell wall of the root hair is presumptively formed from Golgi complex-derived vesicles. Activity of acid phosphatase appeared on tonoplast, plasma membrane, and nuclear envelope, whereas ATPase activity appeared on the plasma membrane, heterochromatin, and mitochondrial cristae.

• Journal of Crop Science and Biotechnology
• /
• v.11 no.1
• /
• pp.57-62
• /
• 2008

Isoflavone content in various parts of six soybean cultivars and soybean sprout during germination was analyzed by high performance liquid chromatography. The parts analyzed were seed coat, cotyledon, and axis for seeds and whole sprout, root, hypocotyl, and cotyledon for sprout. Two cultivars, Aga3 which is known to have the smallest seed size and the highest isoflavone content among the Korean soybean cultivars and Pungsannamulkong which is the most widely being used as soy-sprout, were selected for sampling from 1 to 10 days after germination. At the same weight, the order of isoflavone content increased from seed coat to cotyledon to axis. The highest total isoflavone(isoflavone$\times$dry weight) content was observed in the cotyledon and the lowest in the seed coat. The cotyledon of the Aga3 variety had the highest total isoflavone content and the lowest was measured in the Pungsannamulkong variety. The highest total isoflavone content, $10,788{\mu}g/g$, was observed in whole sprouts(cotyledon+hypocotyl+root) on day 7 for Aga3. After day 7, there was a decreasing trend in isoflavone content as the germination period increased. Total isoflavone content in the cotyledon of Aga3 significantly increased after seed germination, whereas the isoflavone content in the cotyledon of Pungsannamulkong decreased. However, total isoflavone content in the root of both varieties increased while isoflavone content in the hypocotyls decreased after seed germination.

• Journal of Plant Biology
• /
• v.26 no.4
• /
• pp.207-216
• /
• 1983

Mature embryo and developing seedlings of Ginkgo biloba L. were embedded in a paraplast and serially sectioned at 10${\mu}{\textrm}{m}$ to examine vascular differentiation and vascular transition. Procambium and protophloem formed a continuous system along the epicotylhypocotyl root axis and cotyledons in mature embryo, whereas protoxylem was differentiated discontinuously in the cotyledons and rarely in the upper hypocotyl. The traces of the first and second leaf primordia apeared almost at the same time oppositely to each otehr at the epicotyl and alternately with the cotyledon traces in the upper hypocotyl. The trace differentiated bidirectionally toward the epicotyl and root tips. the young root initially formed a diarch xylem. Then, as the traces of the first and second leaves were superimposed, the diarch xylem. Then, as the traces of the first and second leaves were superimposed, the diarch xylem of the root was changed totriarch and tetrarch xylem, respectively. On the formation of primary vascular system of Ginkgo biloba, it is suggested that the primary phloem forms a continuous system throughout the seedling, whereas the primary xylem of the epicotyl is formed independently from that of the root-hypocotyl cotyledon system.