• 한국섬유공학회:학술대회논문집
• /
• 한국섬유공학회 1998년도 가을 학술발표회논문집
• /
• pp.83-86
• /
• 1998

PVC사의 연신은 Fig. 1과 같이 끊는 물 속에서 이루어지며 연신 후 정전기 방지를 위해 유제를 습식 방법으로 처리한다. 따라서 건조와 heat set chamber에 들어가기 전 어느 정도의 수분과 유제를 함유한 체 각각의 chamber를 통과하며 건조, heat set된다. 본 연구의 목표는 연신 후 squeezing roller의 접압에 따른 건조시간의 관계와 heat set온도, 시간에 따른 열 수축률의 관계를 알아보고자 한다. (중략)

• 대한조선학회논문집
• /
• 제42권3호
• /
• pp.259-267
• /
• 2005

The effects of hull flexibility on shaft alignment are growing as ship sizes are increased mainly for container carrier and LNG carrier. In order to consider hull flexibility on a propulsion shafting system, standardization of ship service conditions is necessary because hull deformation is continuously variable according to ship service conditions. How to summarize ship service conditions is suggested based on practically applicable four viewpoints : hull, engine, loading and sea status. Effects of the external forces acting on a ship propulsion shafting system are generally commented. Several design criteria regulated by classification societies are pointed at issue which seems to have Insufficient technical background. A qualitative verification is carried out to point out the invalidity of the assumption of effective supporting position. In this work, an elastic nonlinear multi-supporting bearing system is introduced as a key concept of the elastic shaft alignment. Hertz contact theory is proved to be more proper one than projected area method in calculation of the nonlinear elastic stiffness of the bearing, The squeezing and oil film pressure calculations in the long journal bearing like an after stern tube bearing are recognized as a necessary process for elastic shaft alignment design.

• Geomechanics and Engineering
• /
• 제21권6호
• /
• pp.571-582
• /
• 2020

Aiming at the mechanical and structural characteristics of the contact zone composite rock, the uniaxial compression tests and numerical studies were carried out. The interaction forms and formation mechanisms at the contact interfaces of different materials were analyzed to reveal the effect of interaction on the mechanical behavior of composite samples. The research demonstrated that there are three types of interactions between the two materials at the contact interface: constraint parallel to the interface, squeezing perpendicular to the interface, and shear stress on the interface. The interaction is mainly affected by the differences in Poisson's ratio and elastic modulus of the two materials, stronger interface adhesion, and larger interface inclination. The interaction weakens the strength and stiffness of the composite sample, and the magnitude of weakening is positively correlated with the degree of difference in the mechanical properties of the materials. The tensile-shear stress derived from the interaction results in the axial tensile fracture perpendicular to the interface and the interfacial shear facture. Tensile cracks in stronger material will propagation into the weaker material through the bonded interface. The larger inclination angle of the interface enhances the effect of composite tensile/shear failure on the overall sample.

• 한국전기전자재료학회논문지
• /
• 제34권2호
• /
• pp.126-129
• /
• 2021

We fabricated plate typed shunt resistors composed of carbon nanotube (CNT) and metal alloy for measuring DC current. CNT plates were prepared from dispersed CNT/Urethane solution by squeezing method. Cu/Ni alloys were prepared from composition-designed alloy wires for adjusting the temperature coefficient of resistance (TCR) by pressing them. As well, we fabricated a hybrid resistor by squeezing the CNT/Urethane solution on the metal alloy plate directly. In order to confirm the composition ratio of the Cu/Ni alloy, we used an energy-dispersed X-ray spectroscopy (EDX). Cross-section and surface morphology were analyzed by using a scanning electron microscopy (SEM). Finally, we measured the initial resistance of 2.35 Ω at 25℃ for the CNT paper resistor, 7.56 mΩ for the alloy resistor, and 7.38 mΩ for the hybrid resistor. The TCR was also measured to be -778.72 ppm/℃ at the temperature range between 25℃ to 125℃ for the CNT paper resistor, 824.06 ppm/℃ for the alloy resistor, and 17.61 ppm/℃ for the hybrid resistor. Some of the hybrid resistors showed a near-zero TCR of 1.38, -2.77, 2.66, and 5.49 ppm/℃, which might be the world best-value ever reported. Consequently, we could expect an error-free measurement of the DC current using this resistor.

• 대한심미치과학회지
• /
• 제30권2호
• /
• pp.91-101
• /
• 2021

치간유두의 Connective Tissue Graft (CTG)는 좁은 공간 때문에 아주 까다롭다. 그래서 치간유두의 재생은 아주 도전적인 과제라고 생각한다. 이렇게 인접치와의 좁은공간에서 잇몸이식은 아주어렵지만, 3mm의 공간을 만들 수 있다면 CTG는 그렇게 어렵지 않다. 그래서 교정력을 이용하여 임시적으로 3mm의 공간을 만들어 주고 잇몸이식을 진행하였다. CTG는 마이크로블레이드를 이용하여 치은박리를 시행하였고, 치아사이의 공간에 수직절개를 만들어 그곳을 이용해서 결합조직을 이식하였다. 유지기간후에 교정력을 이용해 다시 치아사이의 공간을 모아서 치아를 배열하였다. 이 방법을 통해 치아사이의 치간유두를 재생하였고 이 술식을 이름을 ELSA (Enlargement of space - Labial graft - Squeezing - for Augmentation of papilla)로 이름지었다. 치주질환 등으로 치간유두가 소실된 경우, ELSA technique을은 치간유두를 재생하는 아주 효과적인 방법이다.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2004년도 ICCAS
• /
• pp.1424-1429
• /
• 2004

In this paper a mathematical framework for deriving acceleration bounds from given joint torque limits of multiple cooperating robots are described. Especially when the different frictional contacts for every contact are assumed and the torque limits are given in 2-norm sense, we show that the resultant geometrical configuration for the acceleration is composed of corresponding parts of ellipsoids. Since the frictional forces at the contacts are proportional to the normal squeezing forces, the key points of the work includes how to determine internal forces exerted by each robot in order not to cause slip at the contacts while the object is carried by external forces. A set of examples composed of two robot systems are shown with point-contact-with-friction model and insufficient or proper degree of freedom robots.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 1999년도 가을 학술발표회 논문집
• /
• pp.59-66
• /
• 1999

ILT proposed by Tezaghi was frequently used which is based on one dimensional consolidation theory. But this test require time longer than a week and has problems for extra soft clay such as the squeezing around the consolidation ring. Also consolidation curve is not clearly defined since only a few data is obtained in a test. Therefore it is difficult to determine Pc and the interpretation to determine the consolidation constants are rather complicated. In this paper, the stress-strain relationship and consolidation constant obtained by CRS and CG-test were analyzed and compared with the results by ILT.

• Biotechnology and Bioprocess Engineering:BBE
• /
• 제7권4호
• /
• pp.221-224
• /
• 2002

Biomass of non-viable and dried brown marine algae Ecklonia radiata Turn. was used to examine Its cadmium uptake capability. Twelve different pretreatments on the algal biomass were prepared. Among these pretreatments, the algal biomass, which treated with 0.1 M NaOH and kept in water. bath (100$\^{C}$, 18 h) followed by washing with distilled water and squeezing, showed the highest amount of cadmium uptake as 1634 $\pm$ 195 mg/g dry biomass at pH 4.0 and 50$\^{C}$. Adsorption temperatures and pH levels played some Important role In cadmium uptake. However, cadmium uptake decreased dramatically at a lower pH than 4.0. Freundlich adsorption isotherm showed potent cadmium uptake capacity of the non-viable biomass. Pretreatments on the non-viable algal biomass shown in this study nay enhance the Eadmium removal in the industrial wastewater.

• 대한수학회보
• /
• 제53권1호
• /
• pp.21-28
• /
• 2016

It is known that no two of the roots of the polynomial equation (1) $$\prod\limits_{l=1}^{n}(x-r_l)+\prod\limits_{l=1}^{n}(x+r_l)=0$$, where 0 < $r_1{\leq}r_2{\leq}{\cdots}{\leq}r_n$, can be equal and all of its roots lie on the imaginary axis. In this paper we show that for 0 < h < $r_k$, the roots of $$(x-r_k+h)\prod\limits_{{l=1}\\{l{\neq}k}}^{n}(x-r_l)+(x+r_k-h)\prod\limits_{{l=1}\\{l{\neq}k}}^{n}(x+r_l)=0$$ and the roots of (1) in the upper half-plane lie alternatively on the imaginary axis.

• Tribology and Lubricants
• /
• 제21권6호
• /
• pp.272-277
• /
• 2005

Continuously variable transmission (CVT) of toroidal type has a elliptical shape of contact zone under the elastohydrodynamic lubrication (EHL) condition, where the power is transmitted only by shearing the lubricant. Due to the small contact area of elliptical shape, the traction of the shear behaviors of lubricant over the contact zone is under extremely high contact pressure over 1.0GPa. During the power transmission by shearing the fluid, many kinds of mechanical movements occur such as squeezing, sliding, rolling and spin. Among the movements, the spin effect that is the most undesirable contact behavior in transmitting the power frequently makes significant abnormal wear damage. In this work, the analysis of elliptical contact of EHL with spin effect is performed, which will give very useful information to understand the traction behaviors in toroidal type of CVT system.