• Title/Summary/Keyword: horizontal plane

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A Study on the Surface Modification of Graphite by CVD SiC -Growth Characteristics of SiC in a Horizontal CVD Reactor- (화학증착 탄화규소에 의한 흑연의 표면개질 연구 -수평형 화학증착반응관에서 탄화규소 성장특성-)

  • 김동주;최두진;김영욱;박상환
    • Journal of the Korean Ceramic Society
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    • v.32 no.4
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    • pp.419-428
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    • 1995
  • Polycrystalline silicon carbide (SiC) thick films were depostied by low pressure chemical vapor deposition (LPCVD) using CH3SiCl3 (MTS) and H2 gaseous mixture onto isotropic graphite substrate. Effects of deposition variables on the SiC film were investigated. Deposition rate had been found to be surface-reaction controlled below reactor temperature of 120$0^{\circ}C$ and mass-transport controlled over 125$0^{\circ}C$. Apparent activation energy value decreased below 120$0^{\circ}C$ and deposition rate decreased above 125$0^{\circ}C$ by depletion effect of the reactant gas in the direction of flow in a horizontal hot wall reactor. Microstructure of the as-deposited SiC films was strongly influenced by deposition temperature and position. Microstructural change occurred greater in the mass transport controlled region than surface reaction controlled region. The as-deposited SiC layers in this experiment showed stoichiometric composition and there were no polytype except for $\beta$-SiC. The preferred orientation plane of the polycrystalline SiC layers was (220) plane at a high reactant gas concentration in the mass transfer controlled region. As depletion effect of reactant concentration was increased, SiC films preferentially grow as (111) plane.

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Correlation between Cephalometric Reference Planes for Clinical Application to Articulators

  • Lee, Sang Hyun;Yang, Il-Hyung;Kim, Tae-Woo;Yeo, In-Sung Luke
    • Journal of Korean Dental Science
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    • v.14 no.1
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    • pp.26-31
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    • 2021
  • Purpose: This study aimed to find a correlation between the occlusal plane and two reference planes that are frequently used in semi-adjustable articulators. Materials and Methods: Sixty-two males and fifty females with normal articulation were recruited and the lateral cephalograms of these patients were taken. The angles between the Frankfort horizontal (FH) and the occlusal planes, the angles between the gnathologic and the occlusal planes, and the angles between the FH and gnathologic planes were measured on the lateral cephalograms. Result: The mean angles between the FH and the occlusal planes was 8.29°±3.62°, with 8.88°±3.09° and 7.63°±4.10° for male and female patients, respectively. The mean angles between the gnathologic and the occlusal planes was 2.77°±3.62°, and the angle between the FH and the gnathologic planes was 5.52°±3.62°. No significant differences were found in the measured angles between the male and female patients (P>0.05). Conclusion: Different guidance angles may be applied to articulators for prosthodontic restoration, depending on the reference planes that the articulators use.

Compensatory changes of occlusal plane angles in relation to skeletal factors (골격적 요소에 따른 교합평면 검사도의 보상적 변화)

  • Kim, Hyun-Sook;Kim, Seon-Young;Lee, In-Seong;Kim, Sang-Cheol
    • The korean journal of orthodontics
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    • v.34 no.3 s.104
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    • pp.229-240
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    • 2004
  • The purpose of this study was to evaluate the compensatory changes of occlusal plane angle in relation to skeletal factors. Lateral cephalograms of 61 adults with normal occlusion and 92 adults with skeletal malocclusions were traced and measured to analyze skeletal factors and occlusal plane angles. In terms of horizontal relationships, the normal occlusion group and malocclusion group were classified Into subgroups of skeletal Classes I, II, and III, while in terms of vertical relationships, each group was also classified into horizontal , average, and vertical subgroups. Some measurements were evaluated statistically by ANOVA and Post Hoc, and the others were reviewed by Paired t-tests. In this study, only the occlusal plane angle to AB plane did not show a significant difference between the normal occlusion group and malocclusion group. After treatment, the occlusal plane angle to the AB plane of the malocclusion group was approximated to that of normal occlusion group. The LOP to AB plane angle of the normal occlusion group was 91.7 in skeletal Class I, 88.8 in skeletal Class II, and 93.5 in skeletal Class III. This study was done to assess the treatment changes of the occlusal plane in the malocclusion group, and to draw a comparison with the normal occlusion group in order to present a reference to establish a new occlusal plane inclination.

Elastic Wave Propagation in Monoclinic System Due to Harmonic Line Load

  • Kim, Yong-Yun
    • The Journal of the Acoustical Society of Korea
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    • v.17 no.2E
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    • pp.47-52
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    • 1998
  • An analysis of dynamic responses is carried out on monoclinic anisotropic system due to a buried harmonic line source. The load is in the form of a normal stress acting along an arbitrary axis on the plane of symmetry within the orthotropic materials: In case that the line load is acting along the symmetry axis normal to the plane of symmetry, plane wave equation is coupled with verital shear wave and longitudinal wave. However, if the line load is acting along an arbitrary axis normal to the plane of symmetry, plane wave equation is coupled with vertical shear wave, longitudinal wave and horizontal shear wave. We first considered the equation of motion in a reference coordinate system, where the line load is coincident with a symmetry axis of the orthotropic material. Then the equation of motion is transformed into one with respect to general coordinate system with azimuthal angle by using transformation tensor. Plane wave solutions of monoclinic systems are derived for infinite media. Finally complete solutions for the plane harmonic wave are obtained by calculating the inverse of the integral transforms, in which bulk wave poles are avoided by deforming the contour of the integration to the complex plane. Numerical results for examples of orthotropic material belonging to monoclinic symmetry are demonstrated.

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Radiological Analysis of Osteoarthritis of the Second Metatarsophlangeal and Tarsometatarsal Joint (제2 중족 족지 및 중족 설상 관절의 관절염에 대한 방사선학적 분석)

  • Kim, Jung-Rae;Kim, Sung-Yoon;Lee, Woo-Chun
    • Journal of Korean Foot and Ankle Society
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    • v.16 no.2
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    • pp.101-107
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    • 2012
  • Purpose: The aim of this study was to investigate the radiological characteristics of the osteoarthritis of the second metatarsophalangeal (MTP) and tarsometatarsal (TMT) joint. Materials and Methods: Between January 2002 and August 2010, 27 patients (33 feet) who had second metatarsal osteoarthritis (OA) were reviewed retrospectively. Group 1 was 14 patients (17 feet) with second MTP joint OA. Group 2 was 13 patients (16 feet) with second TMT joint OA. Group 3 was 24 patients (25 feet) had hallux valgus without second metatarsal (MT) OA as control. Weight bearing foot anteroposterior (AP) and lateral view were checked, and measured hallux valgus angle, metatarsus adductus angle (MAA), second MT functional length, first and second MT length by Hardy & Clapham method on AP view, angle of second MT with horizontal plane, calcaneal pitch, talo-first MT on lateral view. Results: On weight bearing foot AP view, second MT functional length of group 1, 2, 3 was 2.4 mm, -0.1 mm, 0.7 mm and MAA of group 1, 2, 3 was $17.7^{\circ}$, $17.7^{\circ}$, $14.5^{\circ}$. Second MT functional length of group 1 was longer than control group and it was statistically significant. MAA was significant different between group 1-3 and group 2-3. Angle of second MT with horizontal plane of group 2 was smaller than control group and it was statistically significant. Other radiographic parameters have no statistical significance. Conclusion: Group 1 has long functional length of second MT and group 2 has small angle of second MT with horizontal plane.

역에프형 구조를 이용한 RFID 리더기용 편파 및 공간 다이버시티 안테나 설계

  • Kim, Jong-Seong
    • Proceedings of the IEEK Conference
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    • 2006.06a
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    • pp.191-192
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    • 2006
  • An orthogonal antenna is presented for reader applications of radio frequency identification (RFID) at 433 MHz. The antenna is composed of two $1{\times}2$ sub-arrays orthogonally placed on a ground plane. Two different feeding networks are introduced to control horizontal and vertical radiation current flows for each sub-array, respectively. An inverted-F structure is used as a radiation element with vertical and horizontal currents flowing on the radiator, thereby obtaining two linear polarizations. Antenna gains are 3.71 and 3.43 dBi and isolation between the two input ports is less than 25dB.

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SINGLY-PERIODIC MINIMAL SURFACES IN ℍ2×ℝ

  • Pyo, Jun-Cheol
    • Bulletin of the Korean Mathematical Society
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    • v.49 no.5
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    • pp.1089-1099
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    • 2012
  • We construct three kinds of complete embedded singly-periodic minimal surfaces in $\mathbb{H}^2{\times}\mathbb{R}$. The first one is a 1-parameter family of minimal surfaces which is asymptotic to a horizontal plane and a vertical plane; the second one is a 2-parameter family of minimal surfaces which has a fundamental piece of finite total curvature and is asymptotic to a finite number of vertical planes; the last one is a 2-parameter family of minimal surfaces which fill $\mathbb{H}^2{\times}\mathbb{R}$ by finite Scherk's towers.

A study on the Measurement of the Condyle Path Inclination in Relation to Skull Reference Lines by Roentgeno-Cephalometry (Roentgenocephalometry에 의한 한국인 과로와 두부참조선과의 각도계측에 관한 연구)

  • Yun, Young-Yun
    • The Journal of the Korean dental association
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    • v.11 no.2
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    • pp.134-138
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    • 1973
  • The author measured and analyzed the condyle path inclinations of 25 normal Korean adults roentgeno-cephalometrically and following conclusions were obtained. In protrusive movement of mandible, the angle of condyle pation inclination in relation to 1) occlusal plane is 19.86±8.25, 2) Frankfort Horizontal plane is 28.32±8.56, 3) Camper line is 12.22±4.06, 4) Nasion-sella line is 36.80±8.54.

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Fast Algorithm for Location Determination of Mobile Robot: Vertical Line to Point Correspondences (이동로보트의 실시간 위치결정을 위한 수직선과 점 대응 알고리즘)

  • 김재희;조형석
    • 제어로봇시스템학회:학술대회논문집
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    • 1990.10a
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    • pp.716-721
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    • 1990
  • It is one of the essential task to determine the absolute location of mobile robot during its navigation. In this paper we propose an algorithm to calculate the distance and orientation of camera from landmark through the visual image of stripe typed landmark. Exact closed form solution of camera location is obtained with the correspondences from vertical line on mark plane to the intersection point of projected line with horizontal axis of image plane. It needs only one line image information, so that location determination can be processed in real time.

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Maneuvering simulation of an X-plane submarine using computational fluid dynamics

  • Cho, Yong Jae;Seok, Woochan;Cheon, Ki-Hyeon;Rhee, Shin Hyung
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.12 no.1
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    • pp.843-855
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    • 2020
  • X-plane submarines show better maneuverability as they have much longer span of control plane than that of cross plane submarines. In this study, captive model tests were conducted to evaluate the maneuverability of an X-plane submarine using Computational Fluid Dynamics (CFD) and a mathematical maneuvering model. For CFD analysis, SNUFOAM, CFD software specialized in naval hydrodynamics based on the open-source toolkit, OpenFOAM, was applied. A generic submarine Joubert BB2 was selected as a test model, which was modified by Maritime Research Institute Netherlands (MARIN). Captive model tests including propeller open water, resistance, self-propulsion, static drift, horizontal planar motion mechanism and vertical planar motion mechanism tests were carried out to obtain maneuvering coefficients of the submarine. Maneuvering simulations for turning circle tests were performed using the maneuvering coefficients obtained from the captive model tests. The simulated trajectory showed good agreement with that of free running model tests. From the results, it was proved that CFD simulations can be applicable to obtain reliable maneuvering coefficients for X-plane submarines.