• Journal of Plant Biotechnology
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• 제39권3호
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• pp.133-139
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• 2012

The influences of ethylene inhibitors ($AgNO_3$ and silver thiosulfate) and cytokinins (BAP and TDZ) on shoot regeneration from cotyledon and hypocotyl explants of B. napus cv. Youngsan were investigated. The presence of $50{\mu}M$ Silver thiosulfate (STS) in shoot regeneration medium formed shoots at 60-68% after 3-4 weeks of culture, which was enhanced by 2-fold compared to that of Silver nitrate ($AgNO_3$). Moreover, cotyledon explants were more regenerative than hypocotyls; shoots from cotyledon explants began to occur 4-5 days earlier than that of hypocotyl explants. TDZ at a concentration of $8-10{\mu}M$ was effective for shoot regeneration, compared with BAP. Consequently, the optimal shoot regeneration response was observed in medium supplemented with $50{\mu}M\;STS+8{\mu}M\;TDZ$. In transmission electron microscopy (TEM) analysis, higher density of silver nanoparticles was shown to be accumulated widely inside the cell wall and plasmodesmata of regenerating leaf cultured in medium supplemented with $AgNO_3$. By contrast, in the cell cultured in medium with STS, fine-grained deposits were partly observed in the surroundings of the cell wall.

• 한국광물학회지
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• 제2권1호
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• pp.26-36
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• 1989

Clinopyroxene in the Geodo mine belongs to diopside-hedenbergite series. It is widely distributed throughout the mine area together with garnet and is also closely related with Fe-mineralization. Clinopyroxenes in the Geodo mine including two samples from the sangdong and Ulchin Mines are studied using polarized microscope, EPMA, XRD, and IR spectroscopy for occurrence, chemistry, structure, and crystal chemistry. Especially, variations in unit-cell parameters are examined in relation with the substitution scheme between Fe and Mg cations. Clinopyroxenes in the Geodo mine occur in both endoskarn and exoskarn zone. It is mostly anhedral to subhedral with fine- to medium-grained in texture, but some have bigger crystals of short prismatic or columnar habits. Clinopyroxene occurs as monomineralic or is associated with mostly garnet and sometimes with actinolite, magnetite, epidote, and chlorite. Chemical analysis reveals that the Geodo clinopyroxene is diopsidic in composition (Di: 65-96%). This fact is in good contrast with garnet chemistry showing mostly andraditic (An: 41-82%). Especially, clinopyroxene coexisting with magnetite belongs to nearly end member diopside (Di: 97-99%). Thus, diopside-andradite pair indicates that Geodo skarns were formed under the reduced environment. X-ray diffraction analysis shows unit-cell parameters vary with increase of Fe contents: a = 9.765-9.838$\AA$, b = 8.943-9.020$\AA$, c= 5.240-5.253$\AA$.$\beta$ = 105.70-104.83$^{\circ}$, and V =440.64-448.19$\AA$3. It is noted from the least square regression that a, b and V increase linearly with increase of Fe content, while $\beta$ slightly decreases and c remains nearly unchanged as change in Fe content. These trends are to difference between synthetic and natural clinopyroxenes. This fact is also recognized in IR spectra which show a slight shift of several absorption bands toward lower wavenumber region with increasing Fe content.

• 한국재료학회지
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• 제10권2호
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• pp.128-137
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• 2000

가스터빈 블레이드 재료로 사용되는 IN738LC 니켈기 초합금 주조재에 대하여 고온등압압축(HIP) 공정에 의한 미세조직 변화와 고온 피로수명에 미치는 영향을 조사하였다. 세부적으로 HIP 처리에 따른 주조결함 제거와 피로변형 열화재의 물성재생효과 확인에 중점을 두었으며, 이를 위하여 회전굽힘 피로시험을 실시하고 변형전후의 미세조직을 광학 및 주사전자현미경으로 관찰하였다. HIP 처리 전후의 미세조직과 피로수명을 비교, 평가한 결과, 주조재와 열처리재의 피로수명 차는 크지 않았으나 HIP 처리재의 피로수명은 이들과 비교하여 평균 60배 이상 증가한 것으로 나타났다. 또한 인위적으로 고온 피로변형을 가한 열화재를 대상으로 반복 HIP 처리한 결과, 열화 변형조직이 신재 상태로 거의 완전히 재생될 뿐만 아니라, 재료내에 미세하게 잔존하던 주조결함까지 부가적으로 제거됨에 따라 반복 HIP 처리에 의한 피로수명 연장 효과가 크게 나타났다.

• Smart Structures and Systems
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• 제6권3호
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• pp.197-209
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• 2010

The structural state of a bridge is currently examined by visual inspection or by wired sensor techniques, which are relatively expensive, vulnerable to inclement conditions, and time consuming to undertake. In contrast, wireless sensor networks are easy to deploy and flexible in application so that the network can adjust to the individual structure. Different sensing techniques have been used with such networks, but the acoustic emission technique has rarely been utilized. With the use of acoustic emission (AE) techniques it is possible to detect internal structural damage, from cracks propagating during the routine use of a structure, e.g. breakage of prestressing wires. To date, AE data analysis techniques are not appropriate for the requirements of a wireless network due to the very exact time synchronization needed between multiple sensors, and power consumption issues. To unleash the power of the acoustic emission technique on large, extended structures, recording and local analysis techniques need better algorithms to handle and reduce the immense amount of data generated. Preliminary results from utilizing a new concept called Acoustic Emission Array Processing to locally reduce data to information are presented. Results show that the azimuthal location of a seismic source can be successfully identified, using an array of six to eight poor-quality AE sensors arranged in a circular array approximately 200 mm in diameter. AE beamforming only requires very fine time synchronization of the sensors within a single array, relative timing between sensors of $1{\mu}s$ can easily be performed by a single Mote servicing the array. The method concentrates the essence of six to eight extended waveforms into a single value to be sent through the wireless network, resulting in power savings by avoiding extended radio transmission.

• 한국재료학회지
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• 제28권2호
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• pp.108-112
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• 2018

The present study demonstrates the effect of raw powder on the pore structure of porous W-Ni prepared by freeze drying of camphene-based slurries and sintering process. The reduction behavior of $WO_3$ and $WO_3-NiO$ powders is analyzed by a temperature programmed reduction method in Ar-10% H2 atmosphere. After heat treatment in hydrogen atmosphere, $WO_3-NiO$ powder mixture is completely converted to metallic W without any reaction phases. Camphene slurries with oxide powders are frozen at $-30^{\circ}C$, and pores in the frozen specimens are generated by sublimation of the camphene during drying in air. The green bodies are hydrogen-reduced at $800^{\circ}C$ and sintered at $1000^{\circ}C$ for 1 h. The sintered samples show large and aligned parallel pores to the camphene growth direction, and small pores in the internal wall of large pores. The strut between large pores, prepared from pure $WO_3$ powder, consists of very fine particles with partially necking between the particles. In contrast, the strut densification is clearly observed in the Ni-added W sample due to the enhanced mass transport in activation sintering.

• 복식문화연구
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• 제17권6호
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• pp.1112-1128
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• 2009

The purpose of this study was to develop royal costume design with contemporary taste depending on the character of hero, Lee San, and time flow of TV historical drama and research design discrimination and creative expression. As study methods, the literature study using books and theses concerning costume, fine art, culture and history were used for theoretical background and the empirical study method manufacturing actual costume on the basis of literature and relic were used for dress manufacture. The design concept of costume was modern & chic & clean. The costume was designed through straight silhouette, clean & bright colors excluding prime colors, style transformed to permanent straight pleats on the basis of chulik, 100% silk material focusing on high quality and pattern & decoration of the age of Three Kingdoms. As results, the designs of princess' official rob, day dress and chulik, and emperor's official robe, chulik, military dress and chun-dam-bok were developed. The design discrimination depending on social status change. In the period of princess, black, white, silver and blue were used but in the period of emperor, red, gold and black were used. It was expressed through dragon pattern and extended length used in cloth. The design discrimination depending on character change was visualized through color. Although it is not consistent with historical investigation, contemporary fashion design elements were added to royal costume through color contrast of black & white, permanent straight pleats, velcore, wristlet, extended length and layered-look.

• Corrosion Science and Technology
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• 제19권2호
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• pp.100-107
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• 2020

The demand for powder-coated steel used in the marine industry is increasing owing to their superior corrosion resistance. However, the powder coatings used in commercial products can deteriorate easily by the penetration of brine. In an attempt to suppress brine penetration into the powder coating and significantly increase the corrosion resistance, three types of oxide particles were added to the coating. Electrochemical impedance spectroscopy tests in 3.5% NaCl solution were performed to evaluate the corrosion behaviors of the powder coating with oxide particles. The results showed that the addition of SiO₂ particles to a powder coating severely decreased the corrosion resistance due to the easy detachment of agglomerated SiO₂ particles with a coarse size from the coating layer. In contrast, the TiO₂ and SnO₂-added coatings showed better corrosion resistance, and the TiO₂-added coating performed best in the test conducted at room temperature. However, conflicting results were obtained from tests conducted at a higher temperature, which may be attributed to the effective suppression of brine penetration by the fine SnO₂ particles uniformly distributed in the coating.

• 한국임상수의학회지
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• 제25권5호
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• pp.424-428
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• 2008

A 10-year-old castrated male Schnauzer (case 1) and a 13-year-old intact male Schnauzer (case 2) was referred with mass of left hind limb. We performed hemogram, serum chemistry, radiography, ultrasonography, computed tomography, fine needle aspiration and histopathology. The complete blood counts and serum biochemistry results were within the reference range. Radiography showed cutaneous mass with soft tissue density. The lesions of two dogs were revealed a definite marginated hyperechoic mass with vascularization in ultrasonography. Computed tomography showed an isodense mass in the left hind limb region with minimal contrast enhancing in case 1 and heterogenous enhancement in case 2. Cytology from ultrasonographic guided aspiration of the mass was suspected fibrous tissue-derived benign cell in two dogs. A surgical excision was performed in two dogs. In histological examination of the resected mass, cutaneous fibroma was revealed. The two patients were successfully treated by surgery and postoperative care. This report decribes and compares radiographic, ultrasonographic, computed tomographic, cytologic and histopathologic features of the cutaneous fibroma of two schnauzer dogs.

• Journal of Ginseng Research
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• 제39권2호
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• pp.135-140
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• 2015

Background: A leaf cuticle has different structures and functions as a barrier to water loss and as protection from various environmental stressors. Methods: Leaves of Panax ginseng were examined by scanning electron microscopy and transmission electron microscopy to investigate the characteristics and development of the epicuticular structure. Results: Along the epidermal wall surface, the uniformly protuberant fine structure was on the adaxial surface of the cuticle. This epicuticular structure was highly wrinkled and radially extended to the marginal region of epidermal cells. The cuticle at the protuberant positions maintained the same thickness. The density of the wall matrix under the structures was also similar to that of the other wall region. By contrast, none of this structure was distributed on the abaxial surface, except in the region of the stoma. During the early developmental phase of the epicuticular structure, small vesicles appeared on wallecuticle interface in the peripheral wall of epidermal cells. Some electron-opaque vesicles adjacent to the cuticle were fused and formed the cuticle layer, whereas electron-translucent vesicles contacted each other and progressively increased in size within the epidermal wall. Conclusion: The outwardly projected cuticle and epidermal cell wall (i.e., an epicuticular wrinkle) acts as a major barrier to block out sunlight in ginseng leaves. The small vesicles in the peripheral region of epidermal cells may suppress the cuticle and parts of epidermal wall, push it upward, and consequently contribute to the formation of the epicuticular structure.

• 산업경영시스템학회지
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• 제31권1호
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• pp.74-82
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• 2008

The objective of this paper is to remove noises of image based on the heuristic noises filter and to extract a tumor region by using morphology techniques in breast ultrasound image. Similar objective studies have been conducted based on ultrasound image of high resolution. As a result, efficiency of noise removal is not fine enough for low resolution image. Moreover, when ultrasound image has multiple tumors, the extraction of ROI (Region Of Interest) is not accomplished or processed by a manual selection. In this paper, our method is done 4 kinds of process for noises removal and the extraction of ROI for solving problems of restrictive automated segmentation. First process is that pixel value is acquired as matrix type. Second process is a image preprocessing phase that is aimed to maximize a contrast of image and prevent a leak of personal information. In next process, the heuristic noise filter that is based on opinion of medical specialist is applied to remove noises. The last process is to extract a tumor region by using morphology techniques. As a result, the noise is effectively eliminated in all images and a extraction of tumor regions is possible though one ultrasound image has several tumors.