• Title/Summary/Keyword: shape characteristic

Search Result 1,553, Processing Time 0.033 seconds

Characteristic Strength of $\delta$-Al$_2$O$_3$/Aluminum Composite by Rheo-compocasting (반용융 가공법에 의한 $\delta$-Al$_2$O$_3$/Aluminum 복합재료의 강도 특성)

  • 이상필;김만수;김석호;윤한기
    • Proceedings of the KWS Conference
    • /
    • 1995.04a
    • /
    • pp.155-159
    • /
    • 1995
  • A16061 alloy reinforced with 10 vol% $\delta$-A1$_2$O$_3$ short fiber have been fabricated by Rheo-compocasting and squeeze casting and extruded at high temperature using conical shape die and curved shape die with various extrusion ratios.. Tensile and hardness tests were carried out to examine mechanical properties of extruded materials and SEM observation of fractured surface was capable of accounting for fracture mechanism and bonding state of fiber and matrix.

  • PDF

Nondestructive Inspection Method of Composite Laminated Plates by Holographic Interferometry (홀로그래피 간섭계를 이용한 복합적층판의 결함측정)

  • 김석중;김재형;박현철
    • Transactions of the Korean Society of Mechanical Engineers
    • /
    • v.18 no.12
    • /
    • pp.3202-3218
    • /
    • 1994
  • Mode shapes and natural frequencies of vibrating laminated composite plates are taken using real-time and time-average holographic interferometry. Debonds and delamination in the laminated plates are measured nondestructively. During holographic testing of composite plates, it has been found that the conditions for the local resonance in debonds are strongly dependent on the frequency of excitation. A membrane resonance model was proposed to describe this behavior. Relations between characteristic length according to the size, shape of debonds and membrane resonance frequency are presented. Several experiments were performed to verify the membrane resonance model. The agreements between the predicted excitation frequency and the observed resonance frequency are good. The experimental results show that higher stresses and strains due to local resonance lead to the debond detection.

Breeding of Korean Ginseng (Panax ginseng C. A. Meyer)

  • Kwang-Tae Choi;Woo
    • Proceedings of the Ginseng society Conference
    • /
    • 1998.06a
    • /
    • pp.96-102
    • /
    • 1998
  • A lot of individual ginseng plants were selected in the farmer's fields to develop new ginseng varieties with desirable traits. Among them, a promising line has been developed through comparative cultivation of several lines selected with pure line separation of local raced. It was then designated as "KC (denotes Korean Ginseng)" and tested in the regional yield and adaptation trials for 10 years. KG lines grew vigorously after 4 years of age. Especially, KG 102 line arson운 them showed traits of multiple and short stems. As for the root characters, the length of taproot of KG 101 line was longer than that of local race, Jakyung-jong, or other lines ailed the root weight of KG 102 line waIn 15 % higher than that of local race. In general, KG 101, KG 103, KG 104, and Hwangsauk-jong had good root shape. Total amount of ginsenosides of ginseng taproot was the highest in KG 103 line than in local race and other lines. In these studies, we, elected three superior lines, KG 101, KG 102, and KG 103, having characteristic of good root shape, high yield, and large amount of ginsenoside, respectively.

  • PDF

Optimum Design of a Reversed Trapezoidal Fin with Variable Fin Base Thickness (핀 바닥 두께가 변화하는 역 사다리꼴 핀의 최적 설계)

  • Kang, Hyung-Suk
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.20 no.7
    • /
    • pp.455-461
    • /
    • 2008
  • A reversed trapezoidal fin with variable fin base thickness is optimized using a two-dimensional analytical method. For the fin base boundary condition, instead of a constant temperature, heat transfer from the inside fluid to the fin base is considered. Heat loss from the fin tip is not ignored. The maximum heat loss, corresponding optimum fin effectiveness, fin length and base height are presented as a function of the fin base thickness, shape factor and volume.

A Study on the Interference Effect of the Noise Barrier Edge for Railway Noise Reduction (철도소음 저감을 위한 방음벽 상단 간섭효과에 관한 연구)

  • 심상덕;장강석;김영찬;김두훈
    • Proceedings of the KSR Conference
    • /
    • 2002.05a
    • /
    • pp.577-583
    • /
    • 2002
  • We have made known the study of shape development of interference device for vehicle noise control. It's primary object greatly attenuate the noise due to transport vehicle by small products installed on the noise barrier edge. Also, it is able to improve the insertion loss of a noise barrier without increasing the height of noise barrier. The present time, we set up a newly manufactured products on the noise barrier edge and testify to it's the performance use of an experiment and evaluation for the reduction of railway noise. In this paper the frequency characteristic of interference device of noise barriers with attached newly developed products in terms of shape, absorptive material and split panel, are examined using field test around of railroad.

  • PDF

Clinical Practice Guideline for Sasang Constitutional Medicine: The Examination of Sasangin Disease and Diagnosis for Sasang Constitution (사상체질병증 임상진료지침: 사상체질병증 검사 및 체질진단)

  • Kim, Sang-Hyuk;Lee, Siwoo;Lee, Jun-Hee;Lee, Eui-Ju
    • Journal of Sasang Constitutional Medicine
    • /
    • v.27 no.1
    • /
    • pp.110-124
    • /
    • 2015
  • Objectives This study was purposed to develop the clinical practice guideline for examination of Sasangin disease and diagnosis for Sasang Constitution. Methods "Donguisusebowon" and many articles were reviewed and examined for developing clinical practice guidelines. And "Guideline for Educating Public Health Korean Medical Doctors on Diagnosis of Sasang Constitution" was basically used to develop clinical guidelines. Results & Conclusions By researching and discussing the examination of Sasangin disease and diagnosis for Sasang Constitution, we make the principle of the clinical practice guideline, including methods using body shape, facial shape, vocal characteristic and personality etc.

냉음극을 이용한 plasma전자 beam의 전기적 입력특성 II

  • 전춘생;김상현;이보호
    • 전기의세계
    • /
    • v.27 no.6
    • /
    • pp.49-53
    • /
    • 1978
  • This paper investigates on the electric input characterisitcs of plasma electron beam in H$_{2}$ gas chamber with various pressures, effected by the shape and dimension of hollow screen cathode during electron beam is formed. The result are as follows: (1)Electron beam is formed in the region of positive resistance on the characteristic curve which shows the relation between the voltage and current of electron beam, independent of the shape and dimension of hollow screen cathode. (2)At a given electron beam current, electron beam voltage increases with the decreases of hollow screen cathode length and screen mesh number of it. (3)At a given electron beam current, electron beam voltage increases with the diameters of hollow screen cathode and electron beam hole of it.

  • PDF

Development of Aerospace Components Forming Technology using Superplasticity and Diffusion Bonding Characteristic (초소성 및 확산접합을 이용한 우주항공 부품 성형기술 개발)

  • Lee, Ho-Sung;Yoon, Jong-Hoon;Yi, Yeong-Moo
    • Journal of the Korea Institute of Military Science and Technology
    • /
    • v.8 no.3 s.22
    • /
    • pp.51-55
    • /
    • 2005
  • In this paper, a near net shape technology using superplasticity and diffusion bonding characteristics was presented for application to various components of aircraft and missiles. Due to these special characteristics of some aerospace alloys, it is possible to produce complex components to shape very near final dimension with enhanced design freedom, reduced material usage, and overall saving of weight and cost. The high pressure vessel for a space launcher was fabricated with Ti-6Al-4V alloy by superplastic forming and diffusion bonding process and the failure characteristics are compared with conventionally fabricated vessel spin formed and TIG welded. The structural integrity of the superplastic forming and diffusion bonding process was successfully demonstrated.

The Aging Characteristics of Polymer Electrical Insulation Materials bv UV Radiation and Salt Water Spray (옥외용 고분자 전기절연재료의 염수 및 UV조사에 의한 열화 특성)

  • 최남호;한상일;한상옥;박강식;김종석;박양범
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 1997.11a
    • /
    • pp.221-224
    • /
    • 1997
  • In this study we investigated the acting characteristics of Polymers for electrical insulation by UV radiation and salt water spray treatment. We used the Polymers such as EPDM, SR. PTFE. EVA. We measured contact angle and surface resistance to know the aging characteristic of Polymer surface. And we use SEM to observe the change of the surface shape. Dry flashover voltage test impulse voltage test were carried for the polymer insulator(EVA) . Through this experiment and the analysis we could know the polymers have a good resistance to weathering conditions like as salt spray UV irradiation and mix of them. And we can compare the aging characteristics between Polymers. As a result, we could know that the surface characteristics of PTFE is better than the other. And the degree, electrical characteristics is affected by change of surface shape is not big.

  • PDF

Characteristic Analysis of a Linear Synchronous Propulsion System (선형동기전동기의 특성해석)

  • Kim, Dong-Soo;Jeon, Dae-Young;Cha, Guee-Soo;Hahn, Song-Yop
    • Proceedings of the KIEE Conference
    • /
    • 1993.07b
    • /
    • pp.957-960
    • /
    • 1993
  • We calculate characteristics of the linear synchronous propulsion system by the finite element analysis. The finite element method using voltage source can consider the ripple factor caused by the core shape and the distored wave of stator currents caused by the core shape and the back e.m.f. The TRANSRAPID-06 system developed by Germany is adoped for the numerical example.

  • PDF