• 대한두경부종양학회지
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• 제16권2호
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• pp.235-237
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• 2000

It is difficult to find the penetrating foreign bodies in the head and neck area only with history taking and physical examinations. One of the most important things is to detect the precise location of foreign bodies or possibly remained materials. The detection of wooden foreign bodies is important because they can cause phlegmon formation and because wood is often contaminated by Clostridium tetani bacteria. CT has proved to be an expedient method for detecting foreign bodies of various materials in soft tissues, but the wooden foreign body is often misinterpreted as a gas bubble in soft tissue. We have experienced a case of wooden foreign body which has penetrated through nasal dorsum and remained for 4 months. It had been initially misinterpreted as longstanding inflammatory lesion and osteitis of maxilla and nasal bone.

• 상하수도학회지
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• 제31권6호
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• pp.481-490
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• 2017

Water and wastewater treatment has always been a challenging task due to the continuous increase in amount and the change in characteristics of the poorly biodegradable and highly colored organic matters, as well as harmful micro-organisms. Advanced techniques are therefore required to successfully remove these pollutants from water before reuse or discharge to receiving water bodies. Application of ozone, which is a powerful oxidant and disinfectant, alone or as part of advanced oxidation process depends on the complex kinetic reactions and the mass transfer of ozone involved. Micro- and nano bubbling considerably improves gas dissolution compared to conventional bubbles and hence mass transfer. It can also intensify generation of hydroxyl radical due to collapse of the bubbles, which in turn facilitates oxidation reaction under both alkaline as well as acidic conditions. This review gives the overview of application of micro- and nano bubble ozonation for purification of water and wastewater. The drawbacks of previously considered techniques and the application of the hydrodynamic ozonation to synthetic aqueous solutions and various industrial wastewaters are systematically reviewed.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2005년도 생물공학의 동향(XVII)
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• pp.468-474
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• 2005

SOx and NOx are known major precursors of acid rain and thus the abatement of their emissions is a major target in air pollution control. To obtain basic data on the removal process of simultaneous $SO_2/NO$, the optimal reaction condition and the composition of reaction solution for simultaneous removal of $SO_2/NO$, ware investigated using a bubble column reactor. Pilot scrubber was consisted of scrubber, filter and control box. Dust removal rate was 83, 92, and 97% with catalyst flux of 0.5, 0.8, 1.5 L/min, respectively Average dust removal efficiency with a kind of nozzle was about 94 and 90% in STS FF6.5 (5/8in.) and 14 of P.P W(1.0in.), respectively Dust and $SO_2$ were removed more than 98-96% regardless of reactor number. In the case of NO gas, removal yield of 83.3% was achieved after 48 hours in 1 stage, also removal yield of 95.7% was reached in 2 stages. In tile case of application of STS (5/8 in.) and P.P (1.0 in.) as used fill packing, removal efficiency was reached higher than 98% without related to of kind of fill packing.

• 천문학회보
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• 제42권2호
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• pp.42.2-42.2
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• 2017

The Large Magellanic Cloud (LMC) is a unique target to study the detail structures of molecular clouds and star-forming regions, due to its proximity and face-on orientation from us. Most part of the astrophysical subjects for the LMC have been investigated, but the magnetic field is still veiling despite its role in the evolution of the interstellar medium (ISM) and in the main force to influence the star formation process. Measuring polarization of the background stars behind interstellar medium allows us to describe the existence of magnetic fields through the polarization vector map. In this presentation, I introduce the near-infrared polarimetric results for the $39^{\prime}{\times}69^{\prime}$ field of the northeastern region of the LMC and the N159/N160 star-forming complex therein. The polarimetric observations were conducted at IRSF/SIRPOL 1.4 m telescope. These results allow us to examine both the global geometry of the large-scale magnetic field in the northeastern region and the close structure of the magnetic field in the complex. Prominent patterns of polarization vectors mainly follow dust emission features in the mid-infrared bands, which imply that the large-scale magnetic fields are highly involved in the structure of the dust cloud in the LMC. In addition, local magnetic field structures in the N159/N160 star-forming complex are investigated with the comparison between polarization vectors and molecular cloud emissions, suggesting that the magnetic fields are resulted from the sequential formation history of this complex. I propose that ionizing radiation from massive stellar clusters and the expanding bubble of the ionized gas and dust in this complex probably affect the nascent magnetic field structure.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2012년도 전기공동학술대회 논문집
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• pp.123-124
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• 2012

Effervescent atomizer in which the liquid is ejected from nozzle with bubble caused by gas injection into the liquid is one of twin-fluid atomizers. Effervescent atomizer is operated with the lower injection pressure and the smaller air flow rate when compared with those of other twin-fluid atomizers. In this study, we attempted experiment study to investigate the atomization characteristics of effervescent atomizer related with the internal flow condition. The nozzle was made with acrylic material to investigate the nozzle internal flow. The macroscopic spray analysis was conducted with internal flow images and spray images. Furthermore, SMD was measured by using the laser diffraction method. According to this study, the internal flow condition changed from bubbly flow to annular flow as the air-liquid mass ratio(ALR) increases. At that time, the atomization characteristics were improved.

• 한국연소학회지
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• 제5권1호
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• pp.31-41
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• 2000

A numerical study was conducted to investigate the combustion phenomena of regular start and unstart processes based on ISL#s RAMAC 30 experiments with different diluent amounts in a ram accelerator. The initial projectile launching speed was 1800m/s which corresponded to the superdetonative speed of the stoichiometric $H_2/O_2$ mixture diluted with $5CO_2\;or\;4CO_2$. In this study, it was found that neither shock nor viscous heating was sufficient to ignite the mixture at a low speed of 1800m/s, as was found in the experiments using a steel-covered projectile. However, we could succeed in igniting the mixtures by imposing a minimal amount of additional heat to the combustor section and simulate the regular start and unstart processes found in the experiments with an aluminum-covered projectile. The numerical results matched almost exactly to the experimental results. As a result, it was found that the regular start and unstart processes depended on the strength of gas mixture, development of shock-induced combustion wave stabilized by the first separation bubble, and its size and location.

• Advances in pediatric surgery
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• 제2권1호
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• pp.72-76
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• 1996

Annular pancreas is a rare congenital anomaly with the descending duodenum encircled by a ring of pancreatic tissue, which may cause partial or complete obstruction of the duodenum. In newborn, the symptoms can be those of duodenal stasis resulting from partial intestinal obstruction secondary to some degree of duodenal stenosis. A male newborn weighing 2.0 Kg was born by C-section delivery at 37 weeks' gestation to a 27-year-old mother who had a hydramnios. He was in relatively good condition at birth except regurgitation of saliva and intermittent apnea. A plain film of the abdomen showed the double-bubble of gas filled stomach and proximal duodenum, and upper gastrointestinal series showed a dilated proximal duodenum, with a complete obstruction of the descending duodenum. Intraoperative finding revealed encirclement of the duodenal second portion by pancreatic tissue. Duodenojejunostomy was performed. After the operation, he had developed two serious complications, neonatal septicemia by Enterobacter cloacae on postoperative day 12 and systemic candidiasis on postoperative day 19, and been managed with ventilatory support, antibiotics, and antifungal agents with recovery.

• 한국산업융합학회 논문집
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• 제24권6_2호
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• pp.787-793
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• 2021

The global demand for Liquefied Natural Gas(LNG) continues to increase and is facing a big cycle. To keep pace with the increase in international demand for LNG, the demand for LNG fueled ships is also increasing. Since LNG fuel tanks are operated in a cryogenic environment, insulation technology is very important, and although there are various types of insulation applied to Type C tanks, multi-layer insulation and vacuum insulation are typically applied. Powder insulation materials are widely used for storage and transportation of cryogenic liquids in tanks with such a complex insulation structure. In this study, compression tests at room and cryogenic temperature were performed on closed perlite, glass bubble, and fumed silica, which are representative powder insulation material candidates. Finally, the applicability to the Type C fuel tank was reviewed by analyzing the experimental results of this study.

• Nuclear Engineering and Technology
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• 제55권6호
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• pp.2011-2017
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• 2023

Gas submerged jet is an outstanding thermohydraulic phenomenon in pool scrubbing of fission products during a severe nuclear accident. Experiments were performed on the hydraulic characteristics in the ranges of air mass flux 0.1-1400 kg/m²s and nozzle diameter 10-80 mm. The results showed that the dependence of inlet pressure on the mass flux follows a power law in subsonic jets and a linear law in sonic jets. The effect of nozzle submerged depth was negligible. The isolated bubbling regime, continuous bubbling regime, transition regime, and jetting regime were observed in turn, as the mass flux increased. In the bubbling regime and jetting regime, the air volume fraction distribution was approximately symmetric in space. Themelis model could capture the jet trajectory well. In the transition regime, the air volume fraction distribution loses symmetry due to the bifurcated secondary plume. The Li correlation and Themelis model showed sufficient accuracy for the prediction of jet penetration length.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 봄 학술논문 발표대회
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• pp.77-78
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• 2020

In Korea, more than 30,000 tons of waste Styrofoam are produced every year. Styrofoam is spent more than 500 years decomposing during the reclamation process, so it needs to be recycled. The recycling rate of waste styrofoam continues to be the third highest in the world, but it is lower than that of Germany and Japan. Therefore, measures are needed to increase the recycling rate of waste Styropol. Another problem is that cement is mainly used in existing lightweight foam concrete. However, large amounts of CO2 from cement-producing processes cause environmental pollution. Currently, Korea is increasing its greenhouse gas reduction targets to cope with energy depletion and climate change, and accelerating efforts to identify and implement reduction measures for each sector. In 2013 alone, about 600 million tons of carbon dioxide was generated in the cement industry. Therefore, this study replaces CO2 generation cement with furnace slag fine powder, uses crude steel cement for initial strength development of bubble concrete, and manufactures hardening materials to study its properties using waste styrofoam. As a result of the experiment, the hardening agent replaced by micro powder of furnace slag was less intense and more prone to absorption than cement using ordinary cement. Further experiments on the segmentation and strength replenishment of furnace slag are believed to contribute to the manufacture of environmentally friendly lightweight foam concrete.