• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.1
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• pp.666-671
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• 2018

A honeycomb panel is a plate made by attaching two surface plateson eitherside of a honeycomb core. The honeycomb plate hasexcellent specific strength and energy absorption and is suitable for use in regions where good impact resistance is required. Recently, with the increasing the need for a lightweight design to facilitate transportation, numerous studies have been conducted using aluminum honeycomb plates as body materials for vehicles such as automobiles and high-speed trains. In addition, honeycomb plates have excellent sound deadening properties, as well as excellent heat insulation and durability. Savings in weight using lightweight materials such as aluminum alloy for honeycomb panel's skin can lead to increase fuel economy and reduction in air pollution. In this study, in order to improve the design technology of the honeycomb plate material, the manufacturing technology of the aluminum honeycomb core and honeycomb plate material and various mechanical properties of the honeycomb plate were evaluated. From the results, it was found that the design of the manufacturing process of the aluminum honeycomb plate, as well as itsproduction and characteristics, were improved. The resulting excellent energy absorption capability of the honeycomb plate was due to the repetitive core buckling, indicating that the higher the compressive strength, the higher the strength per bonded area.

• The Journal of Korean Academy of Prosthodontics
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• v.58 no.1
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• pp.30-34
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• 2020

Maxillectomy is performed to remove the tumor in the palate, maxillary sinus, buccal mucosa or nasal cavity. The resection range depends on the size and the extent of the tumor and it affects speech production or cause nasal regurgitation during feeding. Obturator can occlude an opening such as an oro-nasal fistula and protect the defect area. Successful reconstrucion of the patient's oral cavity who have gone over the maxillectomy is a difficult task. The condition and number of teeth, the remaining support area, and the extent of the defect area have a great influence on manufacturing the obturator. If these factors are disadvantageous, the prognosis of the prosthesis is uncertain. The final obturator must have a sufficient retention in the patient's oral cavity and must not irritate the surrounding tissue and support area where the resection was performed.In this case, a 55 year old female went through the maxillectomy and the only 3 teeth remained. And the retention of the maxillary prosthesis seems to be poor. So that, we fabricated the closed hollow obturator which has reduced weight compared to the conventional obturator. Consequently the closed hollow obturator can give better sealing and the adaptation.

• Parasites, Hosts and Diseases
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• v.32 no.4
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• pp.259-266
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• 1994

The role of macrophages was observed In intranasally infected CSH/HeJ mice with trophozoites (3 ×105) of Acnnthomoeba culbertsoni which was a kind of free-living amoebae inducing meningoencephalitis in human and experimental animals. The mortality was 60% in the group of intraperitoneally injected mice with silica (0.5 mg/0.5 ml). It was much higher than that of 10% in the group of amoeba infected mice without silica administration. The phagocytic index of peritoneal macrophages co-cultured with Toxoplasma gondii was estimated daily. In contrast to the control and amoeba infected group which didn't show significant fluctuation of the phagocytic indices, the silica administrated group revealed under 3% until day 3, and gradual increase up to 24.7% in day 5 which was same level of amoeba infected group without silica administration. The level of interleukin- lb (IL- lb) measured by ELISA was the highest in the amoeba infected group without silica injection and the lowest in the amoeba infected group with silica administration. In the test of the amoebicidal activity of mice peritoneal macrcphages Dl uitro, silica administration revealed reducing effect on amoebicidal activity of macrophages. In conclusion, macrophages were proven to play a significant role in defense mechanism against the development of experimentally induced Acnnthamoebo menigoencephalitis.

• Fire Science and Engineering
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• v.33 no.3
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• pp.21-28
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• 2019

To examine the mechanical and combustion characteristics of FRTP, either polycarbonate or nylon were used as a matrix, and either glass fiber or carbon fiber were used as the fiber reinforcement. The fiber reinforcement content was differentiated at 0~40 wt%. The tensile strength and heat distortion temperature increased with increasing reinforcement content. When the fiber reinforcement content was above 30 wt%, the flammability rating showed V-0. As the fiber reinforcement content increased from 0 to 40 wt%, the peak heat release rate of polycarbonate decreased by approximately 51% and that of nylon decreased by approximately 24%. The rate of CO generation decreased for a period of time, and then increased. This appears to have resulted from incomplete combustion. The rate of CO₂ generation shows a similar tendency with the heat release rate. As fiber reinforcement content levels increased from 0 to 40 wt%, the CO₂ peak rate of polycarbonate generation decreased by approximately 50% and that of nylon decreased by 28%.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.1
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• pp.45-52
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• 2015

Fiber-reinforced polymer (FRP) has been generally accepted by civil engineers as an alternative for steel reinforcing bars (rebar) due to its advantageous specific tensile strength and non-corrosiveness. Even though some glass fiber reinforced polymer (GFRP) rebars are available on a market, GFRP is still somewhat uncompetitive over steel rebar due to their high cost and relatively low elastic modulus, and brittle failure characteristic. If the price of component materials of GFRP rebar is not reduced, it would be another solution to increase the performance of each material to the highest degree. The tensile strength generally decreases with increasing diameter of FRP rebar. One of the reasons is that only fibers except for fibers in center resist the external force due to the lack of force transfer and the deformation of only outer fibers by gripping system. Eliminating fibers in the center, which do not play an aimed role fully, are helpful to reduce the price and finally FRP rebar would be optimized over the price. In this study, the effect of the hollow section in a cross-section of a GFRP rebar was investigated. A GFRP rebar with 19 mm diameter was selected and an analysis was performed for the tensile test results. Parameter was the ratio of hollow section over solid cross-section. Four kinds of hollow sections were planned. A total of 27 specimens, six specimens for each hollow section and three specimens with a solid cross-section were manufactured and tested. The change by the ratio of hollow section over solid cross-section was analyzed and an optimized cross-section design was proposed.

• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.1
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• pp.49-54
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• 2007

The issue of acid precipitation and related environmental problems in East Asia has been emerging. To evaluate the acidity and chemical characteristics of rainwater in Korea, its chemical properties during cultivation season from April to October in 2005 were investigated at Taean. Also, to estimate the contribution of ions on acidity, ion composition characteristics and neutralization effects by cations were determined. The electrical conductivity balance between measured and estimated values showed a high correlation. Rainwater was highly distributed in the range of pH $4.5{\sim}5.0$. The acidity of rainwater was relatively low during the month of June compared with other monitored periods. $Na^+$ was the main cation, followed by $H^+>Ca^{2+}>NH_4^+>K^+>Mg^{2+}$. Among these ions, $Na^+,\;NH_4^+,\;Ca^{2+}$ and $H^+$ comprised over 94% of the total cations. Rainwater anion composition was more than 80% with $SO_4^{2-}$ and $NO_3^-$. In rainwater samples, $NH_4^+$ and $Ca^{2+}$ contributed greatly to neutralizing the rain acidity. The sulfate content decreased until September, and sea salt derivatives were higher in May and October than during other monitored periods. Also, 78% of the soluble sulfate in rainwater was nss-$SO_4^{2-}$ (non-sea salt sulfate).

• Tuberculosis and Respiratory Diseases
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• v.53 no.2
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• pp.101-112
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• 2002

Background : Toluene diisocyanate(TDI) is a leading cause of occupational asthma. However, the pathogenesis of TDI-induced asthma is largely unknown because there is no suitable animal model. Materials and Methods : We developed a murine model of TDI-induced asthma by performing two sensitization with 3% TDI and one challenge with 1% TDI using ultrasonic nebulization. Results : Similar to occupational asthma in humans, murine TDI-induced asthma includes findings 1) increased inflammatory cells, including neutrophils and eosinophils, 2) histologic changes, including infiltration of inflammatory cells around bronchioles, thickened airway epithelium, contraction of bronchioles, and accumulation of mucus and debris in the bronchioles, 3) increased MMP-9 activity in inflammatory cells in the airway lumen, 4) airway hyperrespnosiveness. Administraion of an MMP inhibitor, MMPI-I, remarkably reduced all these pathophysiological findings. Conclusion : Therefore, we conclude that TDI-induced occupational asthma is associated with the induction of MMP-9 in inflammatory cells, and the inhibition of MMP-9 may be a good therapeutic strategy.

• Korean Journal of Cleft Lip And Palate
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• v.9 no.2
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• pp.93-100
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• 2006

Although the delayed type of rhinoplasty is currently acceptable in the correction of cleft lip and nasal deformity, Delaire tried to achieve the simultaneous nasolabial reconstruction and muscular rearrangement that affect the subsequent skeletal growth of the face. the anatomic muscular reconstruction can be achieved by making the anchorage of the nasolabial muscles of the cleft side to the nasal septum and muscles on the non-cleft side. Two cleft lip patients of 6 and 7 year-old without any previous operation history were treated with the functional cheilorhinoplasty. One patient with incomplete cleft lip underwent a cheiloplasty along with the rearrangement of orbicularis oris muscle. The other patient had a complete cleft lip and palate with accompanying nasal deformity, who underwent the functional cheilorhinoplasty with the reconstruction of anterior nasal base. All the operation was done under the general anesthesia and patients healed without any significant complications. In the incomplete case, the shapes of Cupid's bow was restored, and the length of columella was regained comparable to the non-affected side. In the complete cleft lip and palate case, the depressed nostril was reconstructed with acceptable symmetry by complete releasing of deformed alar cartilage undermined with a dissecting scissors. In summary, the functional repair of cleft lip and nose could be possible at the same time by using Delaire method. This method is effective to correct the primary nasolabial deformity, which results in the restoring favorable anatomy and its function.

• Journal of Veterinary Clinics
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• v.28 no.3
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• pp.314-317
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• 2011

A 16-year-old, spayed female, Maltese dog weighing 4.3 kg was presented with a 2-week history of yellowish nose-and oral-discharge, anorexia and lethargy. In physical examination, indefinite ulcerative mass about $3{\times}3$ cm in size in the left sublingual region, severe gingivoperiodontitis, halitosis, moderate dental calculus, fever and swelling of mandible soft tissue were noted. In radiographic view, periodontitis and bone lysis findings on the left rostral part of maxilla and mandible were observed. In complete blood count and blood chemistry test, thrombocytosis, increased levels of serum $NH_3$, AST and ALP were obtained. Urinalysis revealed hematuria and proteinuria. In histological examination, squamous cell carcinoma was diagnosed. No surgery was performed, but combined treatment with carboplatin and piroxicam was initiated. Five days after initiation of medication, because of insistent vomiting, piroxicam was substituted to meloxicam. Although the therapeutic efficacy of meloxicam could not be known; administration of meloxicam might be less potential to gastrointestinal side-effects than piroxicam. The dog totally received 3 times of carboplatin infusion. Five days after third infusion of carboplatin, the dog was hospitalized with severe lethargy, vomiting and bloody diarrhea. In examination, severe renal failure signs were noted, and the dog was euthanized.

• Journal of Yeungnam Medical Science
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• v.7 no.1
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• pp.105-112
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• 1990

Ketotifen, a benzocycloheptathiophene, has an orally effective antiallergic as well as antihistaminic properties. In pervious studies, Ketotifen has shown encouraging results in patient with allergic rhinitis, either perennial or seasonal. 39 patients with allergic rhinitis had been treated with Ketotifen 1 mg twice daily for 8 weeks. And we obtained following results. 1) The efficacy rate in sneezing attack was 73.5%, in nasal discharge 71%, in nasal obstruction 58%. 2) Some improvements in at least one of three major symptoms were noted within 1 week in 30.7%, within 2 weeks in 55.8%, within 3 weeks in 66.7%, within 8 weeks in 87.2%. 3) Physical findings such as colour, swelling of turbinate, character of rhinorrhea were not improved significantly. 4) Side effect was observed only in one patient with abdominal pain and diarrhea, which was subsided after interruption of administration. These results suggested that Ketotifen was effective in treatment of allergic rhinitis.