• Title/Summary/Keyword: Dimension stability

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A study on the dependance of crucible dimension on AlN single crystal growth (AlN 단결정 성장에 관한 도가니 형태의 의존성에 관한 연구)

  • Yin, Gyong-Phil;Kang, Seung-Min
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.25 no.1
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    • pp.1-5
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    • 2015
  • For the special usage, the effort of developing AlN single crystals has been very hot in the world. The AlN-base UV LEDs are used on the field of sterilization, purification, curing and analyzing, which can advance human's living and medical processes etc.. AlN single crystals were grown by the PVT (Physical vapor transport) method. On the growing process, carbon crucibles with three different types such as normal size, taller than normal and wider than normal were used for comparison. The processing temperature was in the range of $1900{\sim}2100^{\circ}C$ and ambient pressure was 200~1 Torr. When the taller crucible was used, the sublimation mass was greater than normal dimension one but the best condition of growth changes widely. However the wider one gave much sublimation mass and growing condition was more stable than normal dimension. On limited growing furnace system, the changes of crucible dimension of PVT method provide the change of best condition for growth rate, as-grown crystal quality and growth condition stability.

Full-mouth rehabilitation of a patient with severe tooth wear using a gothic arch tracer and stabilization splint. (비기능적 습관에 의한 전반적인 마모 환자의 고딕아치 기록장치 및 교합안정장치를 통한 완전 구강 회복 증례)

  • Sungwoo Ju
    • Journal of the Korean Academy of Esthetic Dentistry
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    • v.32 no.1
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    • pp.23-32
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    • 2023
  • A patient with para-functional habits can cause widespread teeth wear, along with temporomandibular joint disorders and myofascial pain syndrome in the masticatory muscles. Prolonged teeth wear is associated with a decrease in vertical occlusal dimension, leading to issues such as changes in facial morphology, decreased masticatory efficiency, and temporomandibular joint disorders. To achieve a three-dimensional full-mouth rehabilitation in patients with decreased vertical occlusal dimension, accurate diagnosis, analysis, and proactive treatment planning are essential. Prosthetic treatment accompanied by the restoration of physiological vertical occlusal dimension and the re-establishment of a normal occlusal plane is necessary. This case report presents a full-mouth rehabilitation case involving a patient with overall teeth wear, showing decreased vertical occlusal dimension which results in discomfort in the temporomandibular joint and aesthetic dissatisfaction. The report highlights the successful outcome achieved through the use of occlusal stabilization splint for temporomandibular joint stability and Gothic arch tracing devices for the re-establishment of intermaxillary relationships. Also, through adjustments and adaptation assessment using provisional prostheses, favorable outcomes were achieved both functionally and aesthetically.

Quantum-dots light emitting diodes for a next generation display (양자점 기반 차세대 발광다이오드 기술)

  • Heo, Subeen;Kang, Seong Jun
    • Vacuum Magazine
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    • v.4 no.4
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    • pp.14-17
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    • 2017
  • Recently, quantum-dots light emitting diodes (QLEDs) are considered as a next-generation display due to the superior luminescence behaviors, photo stability and narrow spectral emission bandwidth. Moreover, the emission color of QLEDs can be easily controlled by changing the dimension of quantum dots (QDs). A flexible display based on QLEDs can be achieved using low-cost solution process, such as a printing technology. Therefore, QLEDs are expected as a next generation display. In this document, recent progresses in QDs technology will be introduced.

A PERSISTENTLY SINGULAR MAP OF 𝕋n THAT IS C2 ROBUSTLY TRANSITIVE BUT IS NOT C1 ROBUSTLY TRANSITIVE

  • Morelli, Juan Carlos
    • Journal of the Korean Mathematical Society
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    • v.58 no.4
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    • pp.977-1000
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    • 2021
  • Consider the high dimensional torus 𝕋n and the set 𝜺 of its endomorphisms. We construct a map in 𝜺 that is robustly transitive if 𝜺 is endowed with the C2 topology but is not robustly transitive if 𝜺 is endowed with the C1 topology.

The developmental history of Complete denture and its occlusal principle (임상가를 위한 특집 2 - 총의치 발달의 역사와 교합원리)

  • Lim, Young-Jun;Joo, Young-Hun;Lee, Jin-Han
    • The Journal of the Korean dental association
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    • v.50 no.1
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    • pp.13-21
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    • 2012
  • In an edentulous situation, the dentist must make several determinations when constructing artificial teeth. These include vertical and horizontal relationships of mandible with respect to the maxilla, occlusal form and position, vertical dimension, occlusal relationships during both centric closure and eccentric excursive movements. Artificial teeth are attached to a movable base resting on movable and displaceable living tissue subject to damage. They act as a unit; therefore, they must be arranged to function as a unit. Bilateral balanced occlusion is that stability of the denture is attained when bilateral contacts ex ist throughout all dynamic and static states of the denture during function. Lateral excursion in a balanced scheme implies simultaneous working side and nonworking side contact, while occlusal contacts are maintained on both anterior and posterior teeth as the mandible moves anteriorly into protrusion.

Stability Analysis of Jointed Rock Slope by D.E.M (개별요소법에 의한 절리 암반 비탈면의 안정성 해석)

  • Park, Geun-Uck;Lim, Han-Uk
    • Journal of Industrial Technology
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    • v.21 no.B
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    • pp.51-58
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    • 2001
  • The Distinct Element Method (DEM) was used to analyze the stability of jointed rock slope, of which dimension are about 200m(length), 60m(height), $55^{\circ}$ dip. The Barton-Bandis joint model was used, as a constitutive model. The parameters such as JRC and spatial distribution characteristics of discontinuities were acquired through field investigation. Three different cases such as $51^{\circ}$, $45^{\circ}$ and $38^{\circ}$ in angle of rock slope were analyzed to decide a stable slope. To keep the jointed rock slope safely, it is proposed to reduce the height of slope from 60m to 48m and to reduce the angle of the from $55^{\circ}$ to $38^{\circ}$ too.

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A numerical method for dynamic characteristics of nonlocal porous metal-ceramic plates under periodic dynamic loads

  • Abdulrazzaq, Mohammed Abdulraoof;Kadhim, Zeyad D.;Faleh, Nadhim M.;Moustafa, Nader M.
    • Structural Monitoring and Maintenance
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    • v.7 no.1
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    • pp.27-42
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    • 2020
  • Dynamic stability of graded nonlocal nano-dimension plates on elastic substrate due to in-plane periodic loads has been researched via a novel 3- unknown plate theory based on exact position of neutral surface. Proposed theory confirms the shear deformation effects and contains lower field components in comparison to first order and refined 4- unknown plate theories. A modified power-law function has been utilized in order to express the porosity-dependent material coefficients. The equations of nanoplate have been represented in the context of Mathieu-Hill equations and Chebyshev-Ritz-Bolotin's approach has been performed to derive the stability boundaries. Detailed impacts of static/dynamic loading parameters, nonlocal constant, foundation parameters, material index and porosities on instability boundaries of graded nanoscale plates are researched.

Protective Thin Films on PAN Fiber for Water Resistant Modification by Plasma Polymerization (PAN직물의 내수성개질을 위한 보호성 플라즈마중합박막제조)

  • Seo, Eun Deock;Kang, Young Reep;Kim, Jung Dal
    • Textile Coloration and Finishing
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    • v.7 no.2
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    • pp.55-62
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    • 1995
  • Plasma polymerization of Perfiuoropropene(PFP) and n-Hexane was carried out in a tubular type reactor by means of 13.56MHz radio frequency generator at the fixed RF discharge power of 25W and at the pressures of 100mTorr, 140mTorr and 200mTorr. The thin films were deposited on PAN fabrics in order to improve the dimemsional stability of woven states in hot water laundry. IR spectroscopy was used for the analysis of the structures of the thin films deposited and SEM for examination of surfaces of the fabrics. the PAN fabrics, which were coated by thin films at several experimental conditions, were immersed in boiling water for 2 hours and then the dimension stability of woven states were evaluated. In spite of very thin films, the results of surface modification were satisfactory. In general the performace of thin films by PFP was superior to that of n-Hexane.

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수치사진측량을 이용한 암반사면 조사

  • Lee, Jong-Chool;Park, Woon-Yong;Nam, Shin;Kang, Sang-Min
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2003.04a
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    • pp.219-222
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    • 2003
  • Even through hundreds of meters high steep slope is stable, only several ten meters high dull slope could be collapsed. This means that stability of slope is depend on the slope of a surface of discontinuity like faults existing in rock floor. The existence and nonexistence of a discontinuity surface have a very important effect to the stability of a rock floor slope, and examination for geologic peculiarity is one of the most important pant for investigation of stabilities. Accordingly, in the study, we extracted three dimension coordinates of slope with close photogrammetry, and through interpretations of three dimensions' position of fault within rock floor slope, we expect this will be use as a important sauces when evaluate stabilities of rock floor slope.

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Effect of Isocyanate Index on the Properties of Rigid Polyurethane Foams Blown by HFC 365mfc

  • Kim, Sung-Hee;Kim, Byung-Kyu;Lim, Ho
    • Macromolecular Research
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    • v.16 no.5
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    • pp.467-472
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    • 2008
  • Rigid polyurethane foams (RPUFs) were fabricated from crude MDI (CMDI) and polypropylene glycols (PPGs) of various isocyanate indices with a physical blowing agent (HFC 365mfc). There was a tendency for the gel time to decrease and the tack-free time to increase with increasing index value. With increasing index value the foam density and compression strength decreased and the glass transition temperature, dimension stability and thermal insulation increased, while the cell size and closed cell content were virtually unchanged. Allophanate crosslinks and condensation reactions between the isocyanate groups, which are favored with a high index value, exerted significant effects on the properties of RPUFs.