• Title/Summary/Keyword: stable core

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Effect of Bridge Exercise on the Thickness of Abdominal Muscle according to Support and Knee Angle (지지면과 무릎관절 각도에 따른 교각운동이 복부근육의 두께에 미치는 영향)

  • Mun, Dal Ju;Park, Jae Cheol;Choi, Suk Ju
    • Journal of Korean Physical Therapy Science
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    • v.25 no.3
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    • pp.25-31
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    • 2018
  • Background: The purpose of this study was to find out how changes in knee angles in stable and unstable support surfaces affect the muscle thickness of core muscles. Methods: The subjects of this study were 25 male adult. Each knee angle of 120, 90 and 60 degrees, they were performed bridge exercise on the stabilized surface and on the unstable support surface using TOGU, and measured the muscle thickness of the external and internal oblique muscle and the abdominal muscles through ultrasound images. Results: There was no significant difference between the thickness of the rectus abdominis and the internal oblique muscle depending on the support surface and the knee joint bending angles. However, there was a significant difference between the external oblique muscle and the transverse abdominis muscle by knee joint flexion angle. Conclusion: While the muscle thickness of the core muscle was not significantly affected by each support surface during the bridge exercise, there were significant changes in the core muscle as a result of changes in knee angle.

Use of Core-Crosslinked Amphiphilic Polymer Nanoparticles as Templates for Synthesis of Nanostructured Inorganic Materials (코아 가교 양친성 고분자 나노입자 템플레이트를 이용한 무기물 나노 구조체 합성)

  • Kim, Hyun-Ji;Kim, Na-Hae;Kim, Juyoung
    • Journal of Adhesion and Interface
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    • v.16 no.1
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    • pp.6-14
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    • 2015
  • In this study, physically and chemically stable core-crosslinked amphiphilic polymer (CCAP) nanoparticles were prepared using amphiphilic reactive precursors via soap-free emulsion process. Obtained CCAP nanoparticles were used as templates for synthesis of nanostructured $TiO_2$ nanoparticles. First, CCAP nanoparticles dispersed aqueous solutions were mixed with titanium isopropoxide to prepare stable organic-inorganic hybrid sols, and then obtained sols were spin coated onto glass substrate to prepare hybrid thin films onto glass, and then hybrid thin films were calcinated at various temperature to remove CCAP. Nanostructure of calcinated thin fims were examined by SEM. To study effect of CCAP nanoparticles on nanostructure of $TiO_2$ nanoparticles, the morphology of $TiO_2$ nanoparticles prepared using various CCAP templates was compared with that of $TiO_2$ nanoparticles prepared using conventional organic template, nonionic surfactant, Triton X-100.

Long-term outcomes after core extirpation of fibrous dysplasia of the zygomaticomaxillary region

  • Joseph Kyu-hyung Park;Se Yeon Lee;Jong-Ho Kim;Baek-kyu Kim
    • Archives of Craniofacial Surgery
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    • v.24 no.2
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    • pp.59-65
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    • 2023
  • Background: Fibrous dysplasia (FD) is a localized bone disorder in which fibro-osseous tissue replaces the normal bone structure. Patients with craniofacial FD often present with gradual swelling, deformity, and compromised vision or hearing. We previously introduced "the core extirpation method," a novel surgical technique that is minimally invasive like traditional bone shaving but has longer-lasting effects. This study presents the long-term outcomes of our core extirpation method. Methods: We conducted a retrospective analysis of patients who underwent core extirpation for FD of the zygomaticomaxillary region from 2012 through 2021. Computed tomography (CT) scans were performed 6 to 12 months before the operation, immediately before and after the operation, and during follow-up visits. We performed all operations using the upper gingivobuccal approach, and we extirpated the core of the lesion while preserving the cortical structures of the zygoma and the maxilla to maintain symmetrical facial contour. Results: In 12 patients with lesions in the growth phase, anteroposterior/mediolateral (AP/ML) length discrepancies and the volume increased between preoperative and immediate postoperative CT scans. All patients' immediate postoperative AP/ML discrepancies were stable up to 12-17 months postoperatively. Postoperative volume showed continuous lesion growth; the median volume growth rate was 0.61 cc per month. Conclusion: In this article, we present our experiences managing FD using the minimally invasive core extirpation technique, which entails small expected blood loss and can be performed as day surgery. It provides similar cosmetic outcomes as traditional bone shaving but with longer-lasting results. Although there are some limitations with the study's retrospective nature and small sample size, our 4-year follow-up results show promising results of the core extirpation method in well-indicated patients.

Purification and Structural Characterization of P93 Complex from Hyperthermophilic Archaeon Thermococcus profundus (초고온 archaeon인 Thermococcus profundus에서 P93 복합체의 분리 및 구조적 특성)

  • Lee, Mi-Hong;Kim, Suk-Kyoung;Yun, Young-Gun;Park, Seong-Cheol;Bahk, Jeong-Dong;Cheong, Gang-Won
    • Applied Microscopy
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    • v.30 no.2
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    • pp.185-191
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    • 2000
  • An unusually large protein complex was found in the cytosol of the hyperthmophilic archaeon. Thermococcus profundus. The purified protein was shown to be a homomultimer of 93 kDa subunit (P93 complex). The complex is extremely heat stable. During 12 hrs incubation with SDS (final concentration 1%) at $85^{\circ}C$, no changed structure could be observed. Electron image analysis of negatively stained showed that the complex has a single, stable characteristic view and a well-preserved core with threefold rotational symmetry. The periphery of the assembly is composed of a nebulose, possibly flexible, component. Based on the projected structure suggest the P93 complex from T. profundus is composed 24 homomultimer.

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Experimental study of buckling-restrained brace with longitudinally profiled steel core

  • Lu, Junkai;Ding, Yong;Wu, Bin;Li, Yingying;Zhang, Jiaxin
    • Structural Engineering and Mechanics
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    • v.81 no.6
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    • pp.715-728
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    • 2022
  • A new type of buckling-restrained braces (BRBs) with a longitudinally profiled steel plate working as the core (LPBRB) is proposed and experimentally investigated. Different from conventional BRBs with a constant thickness core, both stiffness and strength of the longitudinally profiled steel core along its longitudinal direction can change through itself variable thickness, thus the construction of LPBRB saves material and reduces the processing cost. Four full-scale component tests were conducted under quasi-static cyclic loading to evaluate the seismic performance of LPBRB. Three stiffening methods were used to improve the fatigue performance of LPBRBs, which were bolt-assembled T-shaped stiffening ribs, partly-welded stiffening ribs and stiffening segment without rib. The experimental results showed LPBRB specimens displayed stable hysteretic behavior and satisfactory seismic property. There was no instability or rupture until the axial ductility ratio achieved 11.0. Failure modes included the out-of-plane buckling of the stiffening part outside the restraining member and core plate fatigue fracture around the longitudinally profiled segment. The effect of the stiffening methods on the fatigue performance is discussed. The critical buckling load of longitudinally profiled segment is derived using Euler theory. The local bulging behavior of the outer steel tube is analyzed with an equivalent beam model. The design recommendations for LPBRB are presented finally.

Purification and Characterization of Recombinant Tadpole H-Chain Ferritin in Escherichia coli

  • Chang, So-Ran;Kim, Young-Taek;Kim, Kyung-Suk
    • BMB Reports
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    • v.28 no.3
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    • pp.238-242
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    • 1995
  • The tadpole H-ferritin produced in E. coli was purified and its molecular properties were investigated to obtain information about the contribution of the H-subunit in the reaction of iron core formation. All the expressed subunits were assembled into complete holoprotein in vitro, presumably 24-mer, and the protein was heat-stable. Electron microscopy revealed that the recombinant ferritin forms spherically and contains iron core. No difference was observed in the absorption spectrum of the expressed protein compared to that of the natural ferritin. The Ouchterlony double diffusion of the expressed protein showed that the H-chain ferritin shares an antigenic determinant with natural tadpole ferritin. Rabbit anti-horse spleen ferritin discriminated the H-ferritin from natural ferritin. The rate of ferritin formation by the recombinant H-chain apoferritin was determined to be higher than that shown by natural tadpole ferritin, which consists of H, M and L-subunits. This phenomenon may be caused by the absence of M and L-subunits in the recombinant H-chain apoferritin.

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Thermally Stable Antireflective Coatings based on Nanoporous Organosilicate

  • Kim, Su-Han;Cho, Jin-Han;Char, Kook-Heon
    • Proceedings of the Polymer Society of Korea Conference
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    • 2006.10a
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    • pp.282-282
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    • 2006
  • Nanoporous organosilicate thin films were realized by the microphase separation of pore generating components mixed with an organosilicate matrix. The refractive index of such nanoporous organosilicate films can be tuned in the range of $1.40{\sim}1.22$. With a nanoporous single layer with n ${\sim}1.225,\;99.85\;%$ transmittance in the visible range was achieved. In order to overcome the limitation on the narrow wavelength for high transmittance imposed by single nanoporous thin films, bilayer thin films with different reflectance for each layer were prepared by inserting high refractive index layer with a refractive index of 1.447. It is demonstrated that the novel broadband antireflection coating with improved transmittance can be easily achieved by the nanoporous bilayer thin films described in present study.

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An Experimental Study on the Stress-Strain Relation of Concrete-Filled Steel Tubes (콘크리트충전 강관기둥의 응력-변형도 관계에 관한 실험적 연구)

  • 한병찬;임경택;엄철환;연길환;윤석천;정수영
    • Proceedings of the Korea Concrete Institute Conference
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    • 1995.10a
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    • pp.210-214
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    • 1995
  • Research on concrete-filled steel columns has been conducted. It is also well known that the load and deformation capacity of concrete-filled steel columns are considerable larger than those of widely used reinforced concrete columns and steel encased concrete columns because the concrete core in the steel is confined laterally by the steel. But, most of these works focused on columns with strength enhancement by the confinement effect, so that no local buckling prevented by the concrete. columns because the concrete core in the steel is confined laterally by the steel. But, most of these works focused on columns with strength enhancement by the confinement effect, so that no local buckling prevented by the concrete. This paper, therefore, presents on the stress-strain relation of a concrete filled rectangular steel tube under axial compression. As the results, the axial load verse average axial strain relationship of concrete-filled rectangular steel columns were very stable. The small B/t ratios in concrete-filled rectangular steel columns aren't affected prevention of local buckling but strength enhancement by confinement effect.

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Integrated CFD on Atomization Process of Lateral Flow in Injector Nozzle

  • Ishimoto, Jun
    • 한국전산유체공학회:학술대회논문집
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    • 2006.10a
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    • pp.7-8
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    • 2006
  • The governing equations for high-speed lateral atomizing injector nozzle flow based on the LES-VOF model in conjunction with the CSF model are presented, and then an integrated parallel computation are performed to clarify the detailed atomization process of a high speed nozzle flow and to acquire data which is difficult to confirm by experiment such as atomization length, liquid core shapes, droplets size distributions, spray angle and droplets velocity profiles. According to the present analysis, it is found that the atomization rate and the droplets-gas two-phase flow characteristics are controlled by the turbulence perturbation upstream of the injector nozzle, hydrodynamic instabilities at the gas-liquid interface, shear stresses between liquid core and periphery of the jet. Furthermore, stable and a high-resolution computation can be attained in the high density ratio (pl/ pg = 554) conditions conditions by using our numerical method.

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The Study on Optical Properties by Adding $La_2O_3$ in Multicomponent Glass Fiber (다성분계 Glass Fiber의 $La_2O_3$ 첨가에 따른 광학적 특성에 관한 연구)

  • 김용호;강원호
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1994.11a
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    • pp.21-23
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    • 1994
  • By adding La₂O₃ to optical multicomponent glass composition, after making mother glass and core fiber that enable to enlarge the infrared transmittance region, then surveyed the optical properties. Through thermal analysis of the glass abstained by melt-quenching after selecting stable basic composition on devitrification and replace SiO₂ by 4-12wt% La₂O₃. As La₂O₃ increases up to l2wt% transition temperature, refractive index, density, deformation temperature increased, whereas thermal expansion coefficient decreased. As a result of inspectig transmittance in UV/VIS/IR region, visable region indicated the decrease of transmittance by increasing the La₂O₃ and transmittance region was enlarged by increasing the La₂O₃ in IR region. Also, fabricate core fiber at 820℃ and severy the optical loss we could fact that La₂O₃ composition added 12wt% showed the minimum optical loss.