• Geotechnical Engineering
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• v.13 no.5
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• pp.45-58
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• 1997

In this paper the factors developing ground disturbance with the penetration of PDB mandrels are analysed by using field reconnaissance and laboratory test. In the laboratory tests, the amount of smear zones around the PDB mandrels is compared with respect to the shape and the size of mandrels by penetrating model mandrels of various shapes into the reconstituted clay. The shapes of mandrels selected are circular, oval and rectangular. It was recognized from the field reconnaissance that the size and shape, driving techniques of mandrels, as well as the size and shape of anchor shoe could develop ground disturbance. The mandrels that would reduce the smear effect of clay is oval and rectangular shapes rat her than circular one. It was found that the smear effect becomes smaller as the ratio of the long and short edge of the rectangular shape mandrel becomes larger.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.3
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• pp.262-268
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• 2009

We investigated the properties of inorganic diatomic films like silicon oxide ($SiO_2$) and zinc oxide (ZnO) and their composite films are packed as a passivation layer around Ca cells on glass substrates by using an electron-beam evaporation technique and rf-magnetron sputtering method. When these Ca cells are exposed to an ambient atmosphere, the water vapor penetrating through the passivation layers is adsorbed in the Ca cells, resulting in a gradual progress of transparency in the Ca cells, which can be represented by changes of the optical transmittance in the visible range. Compared with the saturation times for the Ca cells to become completely transparent in the atmosphere, the protection effects against permeation of water vapor are estimated for various passivation films. The thin composite films consist of$SiO_2$ and ZnO are found to show a superior protection effect from water vapor permeation compared with diatomic inorganic films like $SiO_2$ and ZnO. Also, this inorganic thin composite films are also found that their protection effect against permeation of water vapor can be significantly enhanced by choosing their suitable composition ratio and deposition method, in addition, the main factors affecting the permeation of water vapor through the oxide films are found to be the polarizability and the packing density.

• Geomechanics and Engineering
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• v.16 no.3
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• pp.285-293
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• 2018

In densely populated urban areas with a large amount of infrastructure, ground subsidence events can result in massive casualties and economic losses. In South Korea, the incidence of ground subsidence in urban areas has increased in recent years and the number of underground cavities suspected of causing such events has significantly increased. Therefore, it is essential to develop techniques to prevent the occurrence of underground and ground subsidence. In this study, a field test, laboratory test, and numerical analysis were conducted to determine the optimal compaction degree of the upper support layer of any underground cavity below the level of sewer pipes in order to prevent such cavities from collapsing and leading to ground subsidence accidents. During the field test, an underground cavity was simulated using ice, and the generation of the cavity was confirmed using ground penetrating radar. The ground investigation was performed using a cone penetration test, and the compaction of the ground where ground subsidence occurred was evaluated with a laboratory test. The behaviour of the ground under various conditions was predicted using a numerical analysis based on the data obtained from the field test and previous studies. Based on these results, the optimal compaction degree of the ground required to prevent the underground cavity from causing ground subsidence was predicted and presented.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.6
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• pp.714-720
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• 2017

Exposure to ultraviolet (UV) radiation is associated with the development of adverse effects in skin. Among the three types of UV rays, UV-B causes the most damaging effects, inducing sunburn and penetrating the outer skin, resulting in DNA mutations and skin cancer. The objective of this study was to formulate a UV-protective film by incorporating Ecklonia cava extracts. Cells covered with the film were exposed to UV-B (50, 80, and $100mJ/cm^2$). To determine the protective effects of the film, we evaluated cell viability, intracellular ROS generation, and apoptosis. We found that all E. cava extracts absorbed UV light and exhibited protective effects against UV-B-induced photodamage. Among the protective films examined in this study, that incorporating an E. cava 70% ethanol extract (70EX) formed the most effective protection against UV-B in HaCaT cells. These findings suggest that the application of film containing E. cava extract could prevent UV-B-induced photodamage, and offer protection against the detrimental effects of UV radiation, thus maintaining physiological condition.

• Journal of the Korean Applied Science and Technology
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• v.31 no.2
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• pp.183-189
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• 2014

On the basis of our previous research results concerning a batch Teflon coating process on the surface of basalt fiber which has superior fire-resistance and chemical resistance, we have tried to set up suitable operating conditions for continuous polytetrafluoroethylene(PTFE) coating process. The basalt fiber was continuously pre-treated with 7.5 wt%(6.5% of DPU) of triethoxytrifluoropropylsilane(TMTFPS) and then coated with 20 wt% of PTFE dispersions containing 0.25 wt% of penetrating agent sodium bis(2-ethylhexyl)sulfo succinate (DOS-Na) to get the highest tensile and loop strengths. After dipping process, the PTFE coated basalt fiber was dried under 2 m drying chamber at $120^{\circ}C$ with 12 m/min of winding speed and consequently sintered under 2 m sintering chamber at $380^{\circ}C$ for 40 s. Conclusively, PTFE coated basalt fiber whose tensile and loop strengths were to $3.4g_f/D$ and $2.3g_f/D$, respectively, applicable to high temperature sewing thread could be continuously prepared with our pilot scale process under optimum conditions.

• Journal of Korean Neurosurgical Society
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• v.52 no.6
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• pp.528-533
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• 2012

Objective : In the pediatric population the skull has not yet undergone ossification and it is assumed that the diagnostic rate of skull fractures by simple X-rays are lower than that of adults. It has been recently proposed that the diagnostic rates of skull fractures by 3-dimensional computer tomography (3D-CT) are higher than simple X-rays. The authors therefore attempted to compare the diagnostic rates of pediatric skull fractures by simple X-rays and 3D-CTs with respect to the type of fracture. Methods : One-hundred patients aged less than 12 years who visited the Emergency Center for cranial injury were subject to simple X-rays and 3D-CTs. The type and location of the fractures were compared and Kappa statistical analysis and the t-test were conducted. Results : Among the 100 pediatric patients, 65 were male and 35 were female. The mean age was $50{\pm}45$ months. 63 patients had simple skull fractures and 22 had complex fractures, and the types of fractures were linear fractures in 74, diastatic fractures 15, depressed fractures in 10, penetrating fracture in 1, and greenstick fractures in 3 patients. Statistical difference was observed for the predictive value of simple skull fractures' diagnostic rate depending on the method for diagnosis. A significant difference of the Kappa value was noted in the diagnosis of depressed skull fractures and diastatic skull fractures. Conclusion : In the majority of pediatric skull fractures, 3D-CT showed superior diagnosis rates compared to simple skull X-rays and therefore 3D-CT is recommended whenever skull fractures are suspected. This is especially true for depressed skull fractures and diastatic skull fractures.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.3
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• pp.351-358
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• 2007

Carbohydrate-protein interactions are known to be important in gamete interactions. Several evidence indicated that a fucose-containing sulfated polysaccharide fucoidan was potential inhibitor of fertilization in vitro and thus fucose seemed to be part of the recognition signal of gamete interaction in mammals. In recent investigation we found that ${\alpha}$-L-fucosidase activity was present in boar spermatozoa and it was related to sperm binding to and penetration into zona pellucida (ZP) in vitro. The objective of this study was to determine the effects of monosaccharide L-fucose and polysaccharide fucoidan on sperm ${\alpha}$-L-fucosidase activity and relation to sperm-oocyte interaction in pig. Results indicated that the activity of sperm ${\alpha}$-L-fucosidase was largely inhibited (62%) when sperm suspension was treated with monosaccharide L-fucose. It also significantly inhibited the number of sperm binding to ZP (32%) and penetration into zona-intact oocytes (72%), but did not inhibit penetration into zona-free oocytes when fertilization medium contained L-fucose. The chlorotetracycline (CTC) assessment showed that L-fucose did not affect induction of sperm capacitation and acrosome reaction. In contrast, the activity of sperm ${\alpha}$-L-fucosidase was not inhibited when sperm suspension was treated with polysaccharide fucoidan but sperm-ZP binding was greatly inhibited (85%) and completely blocked sperm penetration into zona-intact or zona-free oocytes. The CTC assessment showed that fucoidan increased the F pattern and decreased the AR pattern sperm. These results suggested that the different inhibitory mechanisms were present between monosaccharide L-fucose and polysaccharide fucoidan on sperm-oocyte interaction, the inhibition effect of ${\alpha}$-L-fucose on sperm binding and penetrating into ZP caused sperm ${\alpha}$-L-fucosidase inhibited by ${\alpha}$-L-fucose.

• Conservation Science in Museum
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• v.22
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• pp.1-14
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• 2019

The excavation of the south mound of Hwangnamdaechong Tomb in Gyeongju has yielded diverse types of shell artifacts. Among the them, this paper investigated fragments of shell ornaments with gilt-bronze frames, the use of which has not been identified. It was revealed that the artifacts are in fact nautilus cups, which had never been found previously in excavations in Korea. A nautilus is a species marine mollusk known to be the closest to prehistoric ammonites. It has brown stripes on the surface of the shell and septa inside, and a siphuncle penetrating to the center of the septa. It is known that nautilus cups were made and used in China, but only three examples have thus far been identified. These surviving cups have metal ornaments and are dated to the Western and Eastern Jin periods of China. No nautilus cups have been found in Japan, and the shell ornaments investigated in this study were determined to be the first nautilus cups ever found in Korea. Nautilus cups are mentioned in ancient documents and literature, including in poems by the Tang Dynasty poet Li Bai and in Joseon-period documents. This paper presents the biological characteristics of nautili, cases of excavation of nautilus cups outside Korea, and findings from the basic research of the nautilus cup from Hwangnamdaechong Tomb.

• The Journal of Korean Orthopaedic Ultrasound Society
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• v.4 no.1
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• pp.20-23
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• 2011

Penetrating injury and retained foreign substances in human body are the main causes of visiting to the emergency room. In hand, foreign substances are caused by trauma. The most common plant pieces, the glass fragments and metal fragments should occur in the order. Especially, it's hard to find fragments of plants and plastic materials because of their radiolucency. And although these fragments are removed, it's difficult to differentiated clearly whether residual foreign bodies are in human hand or not. This study reports the authors' experience in the treatment of a patient from whom he removed a residual tree thorn in the operating room. The thorn was found 4 weeks after the trauma by ultrasonography and then the patients' symptoms were improved.

• Journal of Chest Surgery
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• v.30 no.4
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• pp.402-407
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• 1997

The records of 28 patients with traumatic diaphragmatic injuries seen at Masan Samsung Hospital from march 1986 o March 1995 were reviewed. We treated 21 male and 7 female patients ranging in ages from 5 to 68 years. Thc diaphragimatic injuries were due to blunt trauma in'20 cases(Trawc accident 18, compression injury 1, Human trauma 1) and penetrating injuries 8 cases (all stab wound). Most common symptoms were dyspnea 27 (96%), chest pain 26 (93%), abdomianl pain 8 (29%), comatose mentality 36 (11 %). Chest X-ray were elevated diaphragm in 20 cases(71%) find hemothorax in 18 cases (64%) and 25 cascs (89%) were diagnosed or suspected as diaphragmatic inju,rims prcopcrativcly. The repair of 28 cases were performed with thoracic approach in 20 cases, abdominal approach 7, thoracoabdominal approach in 1 cases. There were 5 death (18%) and all death related to the severity of associated injury. (hypovolcmic shock 3, combined head injury 1, renal failure 1).