• 대한정형외과 초음파학회지
• /
• 제1권1호
• /
• pp.14-17
• /
• 2008

반월상 연골 탈출은 슬관절 반월상 연골이 관상면상 3 mm 이상의 전위를 보이는 경우로 반월상 연골의 퇴행성 변화, 파열, 관절 부종, 골극, 골 관절염 등과 관련이 있다. 초음파는 비교적 저렴한 비용으로 바로 그 자리에서 실시간으로 동적 검사를 할 수 있는 장점이 있다. 이에 슬관절 전내측에 존재하는 종괴 1례를 초음파를 이용하여 내측 반월상 연골 탈출로 진단하였기에 문헌 고찰과 함께 보고 하고자 한다.

• 소성∙가공
• /
• 제7권2호
• /
• pp.177-185
• /
• 1998

The kinematically admissible veolcity field is developed for the shapes of dead metal zone and the curving velocity distribution in the eccentric plane dies extrusion. The shape of dead metal zone is defined as the boundary surface with the maximum friction constant between the deformable zone and the rigid zone. The curving phenomenon in the eccentric lane dies is caused by the eccentricity of plane dies. The axial velocity distribution in the plane dies is divided in to the uniform velocity and the deviated velocity. The deviated velocity is linearly changed with the distance from the center of cross-section of the workpiece. The results show that the curvature of products and the shapes of the dead metal one are determined by the minimization of the plastic work and that the curvature of the extruded products increase with the eccentricity.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 1999년도 춘계학술대회논문집
• /
• pp.80-83
• /
• 1999

Rigid Plasticity Finite Element Analysis is developed for the shapes of dead metal zone and the curving velocity distribution in the eccentric square dies extrusion. The shape of dead metal zone is defined as the boundary surface with the maximum friction constant between the deformable zone and the rigid zone. The curving phenomenon in the eccentric square dies is caused by the eccentricity of square dies. The deviated velocity is changed with the distance form the center of cross-section of the workpiece. The results show that the curving of products and the shapes of the dead metal zone are determined by Rigid Plasticity Finite Element Analysis and that the curvature of the extruded products increases with the eccentricity.

• 한국식품과학회지
• /
• 제19권2호
• /
• pp.171-175
• /
• 1987

삶은 국수의 식미 평가를 위한 객관적 측정 방법으로 레오메타에 특수하게 고안한 test cell을 사용하는 층밀림 압출 시험법을 개발하였다. 층밀립 압출 시험에서 얻어지는 힘-거리 곡선을 분석하여 최초 압출력, 최고 압출력, 압출일, 경사도 등의 파라메타를 구하였다. 17종류의 호주밀로부터 만든 밀국수(건면)에 대한 실험 결과, 최초 압출력 압출일은 삶은 국수의 기호도를 가장 크게 영향하는 단단하고 무른 성질과 쫄깃쫄깃한 성질의 정도를 나타낼 수 있었다. 한편, 경사도는 삶은 국수의 저장중에 일어나는 조직감 변화를 감지할 수 있었다. 이들 파라메타들은 원료 밀가루의 단백질 함량, 수분흡수력, 발전시간(D.T.), 인장도와 높은 삼관관계를 나타내었으나 비스코그램의 최고 점도와는 상관관계를 나타내지 않았다. 비스코스램의 최고 점도와 층밀림 압출 시험의 최고 압출력을 두 독립변수로 한 다중회귀분석 결과 관능적 조직감 기호도와의 상관계수는 최고 압출력만을 사용한 단순회귀분석상관계수보다 크게 증가하지 않았다.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2009년도 추계학술대회 논문집
• /
• pp.354-357
• /
• 2009

The effect of texture of an extruded OFHC Cu rod on its sliding wear has been explored. Disk specimens with three different orientations were machined from the Cu rod for the wear test; surfaces of the disk were perpendicular ($0^{\circ}$), inclined with a specific angle ($45^{\circ}$), and parallel ($90^{\circ}$) to the extrusion axis of the rod. The texture was analyzed using an X-ray goniometer by measuring {111}, {200}, and {220} pole figures of each specimen. The analyzed texture was correlated with wear-test results of the Cu specimen. Dry sliding wear tests were performed at room temperature using a pin-on-disk wear tester against an Al2O3 ball. Applied load, sliding distance, sliding speed were fixed as 20 N, 200 m, and 0.5 m/sec, respectively. The $45^{\circ}$-inclined (to the extrusion axis) disk specimen showed the lowest wear resistance with the least data scatters. It has been found that distribution of cube texture strongly influences wear rate of the extruded Cu rod.

• 소성∙가공
• /
• 제7권4호
• /
• pp.340-346
• /
• 1998

A kinematically admissible velocity field is developed for the analysis of twisting of the extruded products with elliptical shapes from round billet. The twisting of extruded product is caused by the lin-early increased rotational velocity from the center on the cross-section of the workpiece at the die exit. In the analysis the rotational velocity in angular direction is assumed by the multiplication of radial distance and angular velocity. The angular velocity is zero at the die entrance. The increase rate of angular velocity is determined by the minimization of plastic work. The results of the analysis show that the angular velocity of the extruded product in creases with the die twisting angle, the aspect ratio of product the friction condition, the reduction of area, and decreases with the die length.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 1998년도 춘계학술대회논문집
• /
• pp.250-253
• /
• 1998

The kinematically admissible velocity field is developed for the shapes of dead metal zone and the curving velocity distribution in the eccentric plane dies extrusion. The shape of dead metal zone is defined as the boundary surface with the maximum friction constant between the deformable zone and the rigid zone. The curving phenomenon in the eccentric plane dies is caused by the eccentricity of plane dies. The axial velocity distribution in the plane dies is divided in to the uniform velocity and the deviated velocity. The deviated velocity is linearly changed with the distance from the center of cross-section of the workpiece. The results show that the curvature of products and the shapes of the dead metal zone are determined by the minimization of the plastic work and that the curvature of the extruded products increases with the eccentricity.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 1998년도 춘계학술대회논문집
• /
• pp.210-213
• /
• 1998

A kinematically admissible velocity field is developed for the analysis of twisting of extruded products. The twisting of extruded product is caused by the linearly increased rotational velocity from the center on the cross-section of the workpiece at the die exit. In the analysis, the rotational velocity in angular direction is assumed by the multiplication of radial distance and angular velocity. The angular velocity is zero at the die entrance and is increased linearly by axial distance from die entrance. The increase rate of angular velocity is determined by the minimization of plastic work. The results of the analysis show that the angular velocity of the extruded product increase with the die twisting angle and the aspect ratio of product and friction condition and reduction area and show that angular velocity increases with the decreases in die length.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 1997년도 춘계학술대회논문집
• /
• pp.130-135
• /
• 1997

A kinematically admissible velocity field is developed for the analysis of twisting of extruded products. The twisting of extruded product is caused by the linearly increased rotational velocity from the center on the cross-section of the workpiece at the die exit. In the analysis, the rotational velocity in angular direction is assumed by the multiplication of radial distance and angular velocity. The angular velocity is zero at the die entrance and is increased linearly by longitudinal distance from die entrance. The increase rate of angular velocity is determined by the minimization of plastic work. The results of the analysis show that the angular velocity of the extruded product changes with the aspect ratio of product and increases with the decreases in die length and in eccentricity of gravity center of the cross-section of workpiece at die entrance from that of the cross-section at the die exit.

• 한국식품과학회지
• /
• 제45권4호
• /
• pp.473-477
• /
• 2013

혼합디자인에 의해 설정된 조건하에서 압출성형한 율무와 밀가루의 압출성형물은 율무 첨가에 대해 여러 반응 요인들이 압출성형물의 특성에 영향을 끼치는 것으로 나타났다. 실험조건은 율무 함량 5-75%, 밀가루 25-95%로 결정하였으며, 수분함량은 20.55%로 고정하여 modified distance based mixture design으로 실험설계 및 분석하였다. Bending 파손강도, WAI, a값 등은 유의성이 없는 것으로 나타났으나, 팽화물의 직경, WSI, L값, b값은 율무와 밀가루의 혼합에 의해 유의성이 존재하는 것으로 나타났다. 팽화물의 직경, L값, b값은 선형 모델로 분석할 수 있었으나 WSI는 quadratic 모델로만 설정이 가능한 것으로 나타났다. 율무의 함량이 많아질수록 외관적으로 팽창되어지는 정도가 적어졌으며, 색상도 어두워지는 것으로 나타났다. 율무의 함량이 증가할수록 L값은 77.84에서 72.73, a값은 1.37에서 1.77로, b값은 19.42에서 17.64로 이동되었다. WSI는 율무와 밀가루가 40%:60%로 혼합되어 압출성형되었을 때 가장 낮게 나타났으며, WAI는 율무와 밀가루 혼합 비율에 대해서는 유의성이 없는 것으로 나타났다. 혼합디자인 계획법은 시리얼류 제품 생산에 적합한 조직 형성과 반응량에 유의한 영향을 미치는 요인 등에 대해 적절한 혼합 비율과 가공 조건 등을 제시할 수 있음을 알 수 있었다. Modified distance based mixture design에 의해, 일반 시중 제품과 유사한 조직감을 나타낼 수 있는 율무와 밀가루, 물의 적정 배합 비율은 60.12:19.42:20.46으로 나타났다.