• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.05a
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• pp.513-516
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• 2008

We have replicated nanopillar arrays using injection molding process of active heating and cooling method by several peltier devices. The injection melding has a high accuracy ed good reproducibility that are essential for mass production at low cost. Conventional molding processes widely use the water-based mold heating and air cooling methods. However, in case of replication for nano-patterned structures, it caused several defects such as air-flow mark, non-fill, sticking and tearing. In this study, periodic nano-scale patterns are replicated by using injection molding with Peltier devices. Porous nano-scale patterns, which have pore diameter range from 120nm to 150nm, were fabricated by using anodizing process. Periodic nano-pore structures ( $20mm\;{\times}\;20mm$) were used as a mold stamp of injection molding. Finally, PMMA with nanopillar arrays was obtained by injection molding process. By using the Peltier devices, the temperature of locally adiabatic molds can be dramatically controlled and the quality of the molded patterns can be slightly improved.

• Journal of Korean Neurosurgical Society
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• v.59 no.1
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• pp.1-5
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• 2016

Chronic subdural hematomas (CSHs) are generally regarded to be a traumatic lesion. It was regarded as a stroke in 17th century, an inflammatory disease in 19th century. From 20th century, it became a traumatic lesion. CSH frequently occur after a trauma, however, it cannot occur when there is no enough subdural space even after a severe head injury. CSH may occur without trauma, when there is sufficient subdural space. The author tried to investigate trends in the causation of CSH. By a review of literature, the author suggested a different view on the causation of CSH. CSH usually originated from either a subdural hygroma or an acute subdural hematoma. Development of CSH starts from the separation of the dural border cell (DBC) layer, which induces proliferation of DBCs with production of neomembrane. Capillaries will follow along the neomembrane. Hemorrhage would occur into the subdural fluid either by tearing of bridge veins or repeated microhemorrhage from the neomembrane. That is the mechanism of hematoma enlargement. Trauma or bleeding tendency may precipitate development of CSH, however, it cannot lead CSH, if there is no sufficient subdural space. The key determinant for development of CSH is a sufficient subdural space, in other words, brain atrophy. The most common and universal cause of brain atrophy is the aging. Modifying Virchow's description, CSH is sometimes traumatic, but most often caused by degeneration of the brain. Now, it is reasonable that degeneration of brain might play pivotal role in development of CSH in the aged persons.

• Elastomers and Composites
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• v.6 no.2
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• pp.47-63
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• 1971

We have studied the blending effects of Diene 33R and styrenebutadiene rubber at various blending ratios of 100/0, 70/30, 50/50, 30/70, 0/100, and of carbon black HAF and ISAF at various compounding ratios of 55 PHR, 65 PHR, 75 PHR for tyre tread rubber. As the results, it was found that ; 1. For tyre tread rubber, when the blending ratio, Diene NF 35R/SBR 1778, indicated 30/70, the physical properties we examined were most excellent. 2. Excellent result was obtained in case of carbon black compounding ratio of 65 PHR. The compounding of ISAF made better result than that of HAF for abrasion quantity, tearing strength, and tensile strength. 3. Heat buildup obtained from compounding carbon black HAF indicated low temperature than that from compounding carbon black ISAF. As the compounding amount of carbon black increased, the heat buildup improved. And as the blending amount of Diene NF 35R decreased, the heat buildup dropped. 4. Carbon black was more efficient to SBR than to Diene Rubber. 5. It is a shortage that elongation revealed low price.

• Elastomers and Composites
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• v.49 no.2
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• pp.149-154
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• 2014

Friction and abrasion behaviors were investigated for SBR rubber compounds reinforced by silica and carbon black. Knife-blade abrader, newly designed based on tearing energy theory, was utilized in order to evaluate the effect of frictional work on the wear rate of the rubber compounds. It was found that the power law relation between frictional work and wear rate worked, in which as the wear rate was increased as frictional work increased. The wear rate could be determined successfully using the knife-blade abrader in which a moving distance of the knife blade in the process of wearing was measured continuously, instead of intermittent measurements of weight loss by wear during experiment.

• Journal of the Semiconductor & Display Technology
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• v.17 no.3
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• pp.46-52
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• 2018

Slitting, which is supposed to be one of the most critical processes in Li-Ion battery manufacturing, is supposed to cut off the uncoated parts of the foil, and cut the wide foils into the size of the Li-ion batteries. Vibrations of slitting machines are the most critical factors for uneven cut surface such as surface roughness and burr, which are the main reasons of the tearing of microporous membranes to separate the cathodes and the anodes, and eventually causing explosion of the batteries. In this study, the structure of a slitting machine has been analyzed through computer simulations to figure out the main reasons of the vibrations. The result of the study shows that simple design alterations of the supporting area and roller without modifying the main structure of the machine can suppress the vibrations effectively, and further to prevent the devastating explosion.

• Journal of English Language & Literature
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• v.57 no.1
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• pp.129-146
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• 2011

Despite the ubiquity of love in the work of Sarah Kane, the theme has been overshadowed by the violence that characterizes her early plays. This essay differentiates Kane from her contemporary "in-yer-face" playwrights, arguing that violence in Kane operates as a means of securing love. Antonin Artaud's concept of cruelty, often (mis)understood in a physical sense alone, provides a clue to the nature of Kane's violence and its relation to love. The essay focuses on Cleansed and Crave, both written in 1998, one about love's redemptive possibility, the other about its pure impossibility. What makes Cleansed hopeful is its violence that works as love's obstacle, creating the illusion that once it is removed love would be possible. The absence of violence in Crave on the contrary lays the illusion of love bare, making it Kane's most despairing play. Kane's oeuvre draws a trajectory of love from hope to despair; as a whole it stages the impossibility of love. To love the other requires the relinquishing of the self, making love logically impossible by depriving the verb of its subject. Love, if possible, would offer the bliss of unity, tearing out the constraint of the Symbolic Order. Kane's only alternative is death, as is expressed in Crave and 4.48 Psychosis.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.34 no.5
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• pp.327-332
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• 2021

Lithium-ion batteries (LIBs) have become a main energy storage device in various applications, such as portable appliances, renewable energy facilities, and electric vehicles. However, the poor thermal stability of LIBs may cause explosion or fire. The thermal runaway is the result of a failure of the separator inside LIB. Damages like tearing, piercing, and collapsing of the separator were simulated in a mechanical, an electrical, and a thermal way, and small discharge pulses of a few mV were detected at the time of separator damages. From the experimental results, this paper provided a method that can identify the separator failure before thermal runaway in the aspect of a potential explosion and fire prevention measures.

• Journal of Chest Surgery
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• v.56 no.1
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• pp.56-58
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• 2023

Untreated severe tricuspid regurgitation (TR) is associated with poor outcomes. Functional TR occurs secondary to dilatation of the annulus and tethering of the leaflets. Ring annuloplasty alone can correct most cases, but is insufficient in cases of severe annular dilatation due to severe leaflet tethering. In such cases, a tricuspid edge-to-edge technique may be an option. However, stitching of the leaflet tips alone is likely to result in tearing of the leaflets. Approximation of the durable chordae tendineae is considered helpful for this problem. Herein, we present the case of a 39-year-old man who had undergone open-heart surgery for acute type A aortic dissection 13 months earlier. A right mini-thoracotomy approach with a beating-heart strategy was used, which did not require unnecessary pericardial adhesiolysis and dissection. This technique had the advantage of reducing the operation time and the risk of bleeding. To summarize, we present a case of tricuspid valve repair in a high-risk patient with severe leaflet tethering that was successfully managed using these methods.

• Steel and Composite Structures
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• v.47 no.2
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• pp.289-296
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• 2023

The failure of a thin-walled tube was studied in this paper based on three failure models. Both proportional and non-proportional loading paths were applied. Proportional loading consisted of combined tension-torsion. Cyclic non-proportional loading was also applied. It was a circular out-of-phase axial-shear stress loading path. The third loading path was a combination of a constant internal pressure and a bending moment. The failure models under study were equivalent plastic strain, modified Mohr-Coulomb (Bai-Wierzbicki) and Tearing parameter models. The elasto-plastic analysis was conducted using J2 criterion and nonlinear kinematic hardening. The return mapping algorithm was employed to numerically solve the plastic flow relations. The effects of the hydrostatic stress on the plastic flow and the stress triaxiality parameter on the failure were discussed. Each failure model under study was utilized to predict failure. The failure loads obtained from each model were compared with each other. The equivalent plastic strain model was independent from the stress triaxiality parameter, and it predicted the highest failure load in the bending problem. The modified Mohr-Coulomb failure model predicted the lowest failure load for the range of the stress triaxiality parameter and Lode's angle.

• Nuclear Engineering and Technology
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• v.17 no.3
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• pp.193-199
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• 1985

Iodine-induced stress corrosion cracking tests of Zircaloy-4 cladding were undertaken using the modified infernal pressurization method. The effects of iodine concentration and applied stress were studied. The critical iodine concentration for SCC was found to be about 0.2 mg/$\textrm{cm}^2$ at 603$^{\circ}$K. The threshold stress was dependent on the test temperature and the mechanical properties of the specimen. The fracture surface showed that the crack propagated stepwise iron one grain to others until the material was unstable and then ruptured mechanically. The initial region showed the transgranular feature and the wedge-shaped cracks. As the crack proceeded, the transgranular and ductile-tearing mired feature appeared in the middle region.