• Fire Science and Engineering
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• v.23 no.6
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• pp.111-115
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• 2009

Acetone LIF and Rayleigh scattering measurements were performed to identify the entrainment of ambient air in the buoyant jet qualitatively. The air entrainment near nozzle exit was enhanced with increasing both an axial distance and Reynolds number. The results supported that the air entrainment had to be considered in isothermal model for the development of its accuracy. Also, this paper provided an isothermal model based on the ideal plume, of which radiative heat loss fraction was assumed to 0.35 and the entainment of isothermal jet was considered. This simple model could be used in compartment or semi-enclosure fires such as tunnel, and it is more reliable because of introducing entrainment effect in isothermal jet.

• Journal of the Society of Naval Architects of Korea
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• v.37 no.4
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• pp.48-55
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• 2000

A basic research of air bubble locus around the ship hull is performed to know the bubble's behavior which is generated around the hull surface. In this paper. bubble's behavior around the ship hull is calculated and experimented with the variation of bubble size and the location of bubble generation. For the use of the equation for bubble locus, Kawakita's equation which include the effect of bubble buoyancy is adopted. For the numerical simulation. a finite difference method based on the MAC method is used. Also experiments are performed about series 60 hull form at CWC. The results of calculation are compared with those of experiment.

• Journal of the Korean Society of Radiology
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• v.84 no.1
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• pp.304-310
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• 2023

Solitary fibrous tumors (SFTs) commonly arise from the pleura and are mostly benign. However, they may develop anywhere in the body, and 10%-30% are malignant. Classically, SFTs appear as solitary enhancing masses, and bilateral presentation is extremely rare. In this case, an 88-year-old male presented with back pain and a history of chronic tuberculous empyema. Imaging studies revealed bilateral paravertebral masses with aggressive radiologic features, which were speculatively presumed as thoracic malignancies in association with chronic empyema. Herein, we report a unique case of bilateral paravertebral malignant SFTs that were accurately diagnosed with a CT-guided coaxial needle biopsy.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.34 no.7
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• pp.97-104
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• 2006

The spray and breakup characteristics of swirling liquid sheet were investigated by measuring the spray angle and breakup length as the axial Weber number Wel was increased up to 1554 and the ambient gas pressure up to 4.0MPa. As Wel and ambient gas density increased, the disturbances on the annular liquid sheet surface were amplified by the increase of the aerodynamic forces, and thus the liquid sheet disintegrated near from the injector exit. The measured spray angles according to the ambient gas density were different before and after the sheet breaks. Before the liquid sheet breaks, the spray angle was almost constant, but once the liquid sheet started to breakup, the spray angle decreased. And the breakup length decreased because of the increase of the aerodynamic force as the ambient gas density and Wel increased. Lastly, the measured breakup length according to the ambient gas density and Wel was compared with the result by the linear instability theory. We found that the corrected linear instability theory considering the attenuation of sheet thickness agrees well with our experimental results.

• Korean Journal of Veterinary Research
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• v.33 no.3
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• pp.465-469
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• 1993

This paper dealt with the histopathological findings on the natural cysticercosis in pigs. Three cases of porcine cysticercosis, which had been kept in the Department of Veterinary Medicine, Cheju. University more than ten years, were histopathologically examined in order to see the host reaction to the parasite. Capsules containing scolex were mainly found in the fascia of skeletal muscle, heart, and brains. Microscopically, cysticerci in the epicardium and the fascia of skeletal muscles were encapsulated with fibroblasts and collagen fibers. Around capsules, there was infiltration of eosinophils, lymphocytes and macrophages, although the degree and severity of inflammatory reaction varied case by case. Cerebral cortex also had the inflammatory exudate of lymphoid cells in the vicinity of the scolex. whereas perivascular lymphocytic cuffings were commonly seen around capsules. GFAP immunoreactive fibers formed a limiting membrane along the outer side of capsules. There was also proliferation of GFAP-positive astrocytes encirling infiltrating lymphocytes around vessels. In the central nervous system, astrocytes and lympoid cells play an important role in the demarcation of cysts and local immunity, respectively. In conclusion, host tissue reaction in porcine cysticercosis seemed to vary significantly according to the affected organs of pigs. It is assumed that capsules containing worms seemed to be formed at early stage of cysticercosis.

• Applied Microscopy
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• v.28 no.1
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• pp.73-82
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• 1998

To elucidate how microfilaments and vesicles participate in bile formation, the pericanalicular cytoplasms were observed in the liver of rats treated with taurocholic acid by deep etching with rapid freezing, and copmpared them with the findings on convensional thin sections. The microfilaments were identified around the bile canaliculi in the forms of core filaments of microvilli, filaments of pericanalicular web running in parallel to the border of bile canaliculi, and filaments on the junctional complex. In taurocholic acid-treated rats, microfilaments could be visualized around the bile canaliculi and along their borders. The microfilaments appeared to be installed to link to both the canalicular membrane and vesicles. Such specialized microfilaments are considered to participate in the translocation of vesicles in the pericanalicular cytoplasm. From the evidence, it is assumed that the microfilament induces the vesicles to transport and fuse to bile canalicull into which bile acids is secreted by exocytosis.

• The korean journal of orthodontics
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• v.36 no.4
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• pp.251-262
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• 2006

Objective: The purpose of this study was to compare the bacterial flora at the peri-implant sulcus of the orthodontic mini-implant placed in the alveolar mucosa with the bacterial flora at the adjacent healthy gingival sulcus. Methods: Two plaque samples from 7 patients were collected by inserting paper points into the sulcus between the mini-implant and ligature wire connected to the mini-implant head and inflamed alveolar mucosa, and from the gingival sulcus of a healthy tooth adjacent to the mini-implant. Results: Using 16S rDNA clone library, the 24 kinds of bacteria including Haemophilus aphrophilus, Sphingomonas species, Capnocytophaga species, Prevotella melaninogenica, Lachnospiraceae species, Porphyromonas species, Neisseria flava were identified only from the sulcus around the mini-implant. These bacteria constituted only 9.2% of total clones, and the bacteria identified from both the sulcus around mini-implants and the gingival sulcus constituted 80.4% of total clones. Of these bacteria, clones of Prevotella species, Atopobium rimae, Veillonella species, Streptococcus intermedius/constellatus, Streptococcus salivarius were more frequently isolated from the peri-implant sulcus. Conclusion: This study suggests that a broad epidemiological study is needed to find causative bacteria which induce inflammation from the peri-implant sulcus.

• Pediatric Infection and Vaccine
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• v.15 no.1
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• pp.36-44
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• 2008

Purpose : Orbital cellulitis is rare, but it could be from the serious complication of sinusitis in children. It is often difficult to distinguish periorbital cellulitis from orbital cellulitis. The purpose of this study is to describe the clinical features of orbital and periorbital cellulitis in a pediatric population and to assess the predisposing factors and their complications. Methods : Forty-one patients aged 18 years and younger who were admitted between January 2000 and December 2006 to Hanil General Hospital and Kyunghee University Hospital with orbital or periorbital cellulitis. The retrospective analyses included clinical characteristics of orbital and periorbital cellulitis, dermographics, past history, predisposing factors, clinical presentations, treatments, and complications. Results : Among 41 patients, 34 patients had periorbital cellulitis, 7 patients had orbital cellulitis. While paranasal sinus disease was the most common predisposing cause in orbital cases, skin lesion, insect bite, dacrocystitis and conjunctivitis were the common causes in periorbital cases. In comparison with periorbital cases, orbital cases had higher level of white blood cell count, erythrocyte sedimentation rate, and C-reactive protein. Blood cultures were taken in 23 patients, but only one had Staphylococcus aureus from blood. Only one case had surgical incision and drainage and recovered without complications. Conclusion : From the results of our data, when patient shows erythematous swelling of periorbital area with opthalmoplegia, chemosis and proptosis, orbital CT scan is required to make diagnosis of orbital cellulitis. Most cases of orbital cellulitis can be treated successfully without surgical intervention. If there is no clinical improvement, repeated CT scan and/or surgical intervention should be considered.

• Clinical and Experimental Pediatrics
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• v.48 no.12
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• pp.1330-1336
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• 2005

Purpose : It has been suggested that changes in cerebral blood flow by ventilator care could be a risk factor in periventricular leukomalacia(PVL) and severe periventricular-intraventricular hemorrhage(PV-IVH). The study aims to assess the relationship between perinatal clinical events, including ventilator care, and the development of PVL and severe PV-IVH; especially, whether ventilator care could be causers of PVL and severe PV-IVH as an individual risk factor. Methods : Among 255 very low birth weight infants who survived in the Fatima neonatal intensive care unit from January 1999 to December 2003, 15 infants with PVL and eight infants with severe PV-IVH were classified as a study group, while 231 infants were enrolled as a control group. The analysis was performed retrospectively with medical records. Results : Twenty four infants were diagnosed with PVL or severe PV-IVH. Asphyxia, recurrent apnea, sepsis, acidosis and ventilator care were significantly increased in the PVL goup. Asphyxia, recurrent apnea, RDS, acidosis and ventilator care were significantly increased in the severe PV-IVH group. Conclusion : Infants with PVL or severe PV-IVH may have multiple perinatal risk factors including asphyxia, recurrent apnea, sepsis, acidosis, RDS and ventilator care. Because most patients with ventilator care have multiple perinatal risk factors, ventilator care does not cause PVL and severe PV-IVH independently. Therefore, incidences of PVL and severe PV-IVH can be decreased by not only gentle ventilation, but also more professional antenatal care.

• Neonatal Medicine
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• v.17 no.1
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• pp.64-74
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• 2010

Purpose : The aim of this study was to determine the risk factors, clinical characteristics and prognosis for the development of periventricular leukomalacia (PVL) in preterm infants according to the extent and site of the PVL. Methods : The medical records of infants (under 36 weeks of gestational age) delivered from January 1999 to December 2008 were reviewed. Twenty-five preterm infants with were PVL were diagnosed by brain magnetic resonance imaging (MRI) and an addition 50preterm infants with no brain lesions were enrolled in this study. The perinatal and neonatal risk factors for the development of PVL was determine in these infants. Mental and Psychomotor Developmental Indices (MDI, PDI) were assessed by a clinical psychologist using the Bayley Scales of Infant Development II. We compared the differences of the clinical characteristics and prognosis according to brain MRI findings. Results : Maternal fever, young maternal age, extended oxygen use, hypotension within the first week of birth, use of inotropics within the first week of birth, and respiratory distress syndrome were the risk factors associated with PVL (P <0.05). In the multivariate analysis, maternal fever and extended oxygen use were statistically significant independent risk factors (P <0.05). The mean MDI and PDI scores of the PVL group (74.4$\pm$ 27.8 and 58.0$\pm$17.7) were significantly lower than those of the control group (103.5$\pm$8.9 and 101.7$\pm$16.1, P <0.05). Conclusion : Maternal fever and extended oxygen use were independent risk factors for PVL. We should pay attention to infants who had the risk factors and follow them up closely by brain imaging study and Bayley Scales of Infant Development II.