• Proceedings of the Korean Society of Crop Science Conference
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• 2005.04a
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• pp.188-189
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• 2005

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.11a
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• pp.189-189
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• 2005

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.10a
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• pp.1070-1073
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• 2004

This paper is on the development of a system for removing membranes which is designed exclusively for aircraft components. Membrane removal solution is a most critical issue in aerospace industries since a method of manufacturing the components tends to be changed from fabrication of many parts to cutting into one body. The cutting method inevitably produces a huge amount of chips and then membranes remain in the body. The membrane removal process, as a result, becomes an important issue since it is directly related to productivity. We tried to develop a new machine which will replace the conventional method that uses a handy tool. The machine has been designed for a cutting tool set to follow the unique shape of the slot in the body by a cam follower and cut the membrane automatically. The design has been checked by structural analysis: stress and vibration analysis. A prototype test has been finished. This paper summarizes a series of development process of the deburring machine and some design issues are discussed.

• Transactions on Electrical and Electronic Materials
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• v.14 no.3
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• pp.116-120
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• 2013

This paper proposes a novel RF MEMS dc-contact switch with stiff membrane on a quartz substrate. The uniqueness of this work lies in the utilization of a seesaw mechanism to restore the movable part to its rest position. The switching action is done by using separate pull-down and pull-up electrodes, and hence operation of the switch does not rely on the elastic recovery force of the membrane. One of the main problems faced by electrostatically actuated MEMS switches is the high operational voltages, which results from bending of the membrane, due to internal stress gradient. This is resolved by using a stiff and thick membrane. This membrane consists of flexible meanders, for easy movement between the two states. The device operates with an actuation voltage of 6.43 V, an insertion loss of -0.047 dB and isolation of -51.82 dB at 2 GHz.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1998.10a
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• pp.266-273
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• 1998

The object of this study is shape finding and cutting pattern generation of membrane structures under the following assumptions: (1) material is linearly elastic (2) stress state is plane stress. Cable and membrane structures should introduce the nonlinear analysis considering geometric nonlinearity because these structures deform largely under the external loads. The analysis procedure is consisted of three steps considering geometric nonlinearity unlike any other structures. First step is the shape finding analysis to determine the initial equilibrium shape. Second step is the stress-deformation analysis to investigate the behaviors of structures under various external loads. Once a satisfactory shape has been found, a cutting pattern based on the shape finding analysis may be generated from the view point of construction. In this paper, after shape finding analysis, cutting pattern determination procedure using weighted least-square minimization flattening method and some results are presented.

• Geomechanics and Engineering
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• v.2 no.4
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• pp.281-302
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• 2010

An extended model for the response of a rigid footing on a reinforced foundation bed on super soft soil is proposed by incorporating the rough membrane element into the granular bed. The super soft soil, the granular bed and the reinforcement are modeled as non-linear Winkler springs, non-linear Pasternak layer and rough membrane respectively. The hyperbolic stress-displacement response of the super soft soil and the hyperbolic shear stress-shear strain response of the granular fill are considered. The finite deformation theory is used since large settlements are expected to develop due to deformation of the super-soft soil. Parametric studies quantify the effect of each parameter on the stress-settlement response of the reinforced foundation bed, the settlement and tension profiles.

• Archives of Pharmacal Research
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• v.19 no.3
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• pp.183-190
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• 1996

There are a wide variety of semi-solid ointments used for healing the skin diseases, whose therapeutic and skin penetration abililties may greatly differ from one another depending on the compositions of ointment vehicles. A computer optimization technique was applied to obtain the optimum formula of o/w type ointment giving the in vitro maximum absorption rate through hairless rat skin membrane. Some of the formulations were selected to find out a relationship between skin penetration of ointment and its Theological characteristics. The experimental value of absorption rate obtained from the ointment by optimum formula agreed well with the theoretical value obtained from a polynomial regression analysis, Three kinds of ointments selected among 15 formulations were obtained with a concentric cylinder type rheometer (Model; Rheolab SM-HM Physica, Germany) at 20, 30, 40 and $50^{\circ}C$ for rheograms of rhelolgical properties of o/w type ointments. As the temperature was raised, all products showed a decrease in both shear stress and yield values. The higher skin penetration, the lower shear stress showed.

• Journal of Life Science
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• v.20 no.12
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• pp.1820-1828
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• 2010

Cobalt(II) chloride, a chemical compound with the formula$CoCl_2$, has been widely used in the treatment of anemia, as a chemical agent for the induction of hypoxia in cell cultures, and is known to activate hypoxic signaling. However, excessive exposure to cobalt is associated with several clinical conditions, including asthma, pneumonia, and hematological abnormalities, and can lead to tissue and cellular toxicity. It is also known to induce apoptosis. One of the questions was that of whether $CoCl_2$ might induce apoptosis via endoplasmic reticulum (ER) stress in neurons. To address this question, first, the level of DNA fragmentation was measured for assay of apoptotic rates using $CoCl_2$ with neuron PC12 cells. After confirmation of apoptosis inductions, under the same conditions, the expression levels of ER stress associated factors [ER chaperones Bip, calnexin, ERp72, ERp29, PDI, and ER membrane kinases (IRE1, ATF6, PERK)] were examined by RT-PCR and Western blotting. These results indicated that apoptosis is induced through activation of ER membrane kinases via ER stress. In conclusion, during induction of apoptosis through $CoCl_2$-induced hypoxia in neuron PC12 cells, ER membrane kinase of IRE1 was dominantly up-expressed, and, consecutively, TRAF2, which has been suggested to be one of the links connecting apoptosis and ER stress, was strongly up-expressed.

• Ecology and Resilient Infrastructure
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• v.10 no.3
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• pp.64-72
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• 2023

Biopolymer is a versatile material used in food processing, medicine, construction, and soil reinforcement. 𝛽-glucan is one of the biopolymers that improves the soil water content and ion adsorption in a drought or toxic metal contaminated land for plant survival. We analyzed drought stress damage reduction in sweet potatoes (Ipomoea batatas L. cv. Sodammi) by measuring the growth and major protein expression and activity under 𝛽-glucan soil amendment. The result showed that sweet potato leaf length and width were not affected by drought stress for 14 days, but sweet potatoes grown in 𝛽-glucan-amended soil showed an effect in preventing wilting caused by drought in phenotypic changes. Under drought stress, sweet potato leaves did not show any changes in electrolyte leakage, but the relative water content was higher in sweet potatoes grown in 𝛽-glucan-amended soil than in normal soil. 𝛽-glucan soil amendment increased the expression of plasma membrane (PM) H⁺-ATPase, but it decreased the aquaporin PIP2 (plasma membrane intrinsic protein 2) in sweet potatoes under drought stress. Moreover, water maintenance affected the PM H⁺-ATPase activity, which contributed to tolerance under drought stress. These results indicate that 𝛽-glucan soil amendment improves the soil water content during drought and affects the water supply in sweet potatoes. Consequently, 𝛽-glucan is a potential material for maintaining soil water contents, and analysis of the major PM proteins is one of the indicators for evaluating the biopolymer effect on plant survival under drought stress.

• Journal of the Korean Institute of Gas
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• v.13 no.1
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• pp.21-27
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• 2009

This paper presents the numerical study on the strength safety of the prestressed concrete outer tank for a LNG storage tank, which is manufactured by sets of membrane panels with special corrugations. This study for a finite element analysis assumes that the membrane panel of the inner tank was fractured and the liquefied natural gas stored in the inner membrane tank was leaked to the prestressed concrete outer tank. The stress and displacement of the outer tank have been analyzed for five different loadings, which are originated by a hydrostatic pressure and a weight of a LNG, a temperature difference, a weight of the prestressed concrete and a boil-off gas pressure. The computed FEM results indicate that the PC outer tank with a storage capacity of 200,000$m^3$ has a good strength safety for a leaked LNG from the membrane inner tank, but the increased cryogenic loadings in which are originated by a leaked LNG decreases the strength safety of the PC structure. This may lead to the collapse of the outer storage tank.