• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1479-1483
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• 2008

The three main physiological functions of nose are air-conditioning, filtering and smelling. Knowledge of airflow characteristics in nasal cavities is essential to understand the physiological and pathological aspects of nasal breathing. Several studies have utilized physical models of the healthy nasal cavity to investigate the relationship between nasal anatomy and airflow. In our laboratory, there have been a series of experimental investigations on the nasal airflow in normal and deformed nasal cavity models by PIV under both constant and periodic flow conditions. In this time, airflow inside normal nasal cavity is investigated numerically by the FVM general purpose code. The comparisons with PIV measurement are appreciated. Heat and humidity transfer is dealt numerically. Dense CT data and careful treatment of model surface under the ENT doctor’s advice provide more sophisticated cavity models for both PIV experiment and numerical grid system. Average and RMS velocity distributions have been obtained for inspirational and expirational nasal. Temperature distribution, heat and humidity transfer through the mucosa are obtained.

• Composites Research
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• v.12 no.5
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• pp.12-22
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• 1999

Aluminum based metal matrix composites(MMCs) are well known for their high specific strength, stiffness and hardness. They are gaining further importance because of their high wear resistance. In this study wear behavior of $Al/Al_2O_3/C$ hybrid MMCs fabricated by squeeze infiltration method was characterized by the abrasive wear test under various sliding speeds at room and high temperature. Wear resistance of MMCs was improved due to the presence of reinforcements at high sliding speed. Especially wear resistance of carbon hybrid MMCs was superior to other materials because of its solid lubrication of carbon. The friction coefficient of MMCs was not affected by the sliding speed.

• Korean Journal of Head & Neck Oncology
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• v.25 no.2
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• pp.163-167
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• 2009

Sinonasal malignant tumors comprise less than 1% of all cancers and 3% of all malignant tumors of the head and neck, which explains a lack of large series addressing the clinical characteristics and management of these tumors. Neck node metastasis occurs in only about 7% to 15% of malignant tumors compared with other head and neck cancers. A 90-yr-old woman presented with left palpable neck mass and right nasal mass occupying nasal cavity. Fine needle aspiration biopsy of left neck mass results in metastatic squamous cell carcinoma(SCC). PET/CT shows intense FDG uptake in right nasal cavity with bone invasion. Histopathologic examination of excised lesion in the right nasal cavity revealed SCC. We report here on a primary sinonasal SCC with contralateral lymph node metastasis.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.178-178
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• 1993

생리활성 펩타이드류의 경점막 수송을 검토하기 위하여 토끼의 비강, 직장, 질 또는 눈 점막 구출액에서의 메치오닌엔케팔린 (Met-Enk) 및 그 합성 유사체인 [D-알라$^2$]-메치오닌엔케팔린아미드 (YAGFM)의 효소적 분해를 억제하고자 수종 효소억제제를 검토하였다. 방법: 토끼의 질, 직장 및 비강 점막을 차례로 적출하여 신속히 Valia-Chien투과셀에 마운팅하고, 눈의 각막은 절취하여 따로 각막 투과셀에 마운팅한 다음 등장 인산염 완충액 3.5ml씩으로 8시간씩 3회 추출하여 점막측 및 장막측 추출액을 제조하였다. 추출 완료 직후 이들 추출액에 Met-Enk 또는 YAGFM 50$\mu\textrm{g}$/ml의 농도로 첨가하고 여러 효소억제제를 단독 또는 혼합하여 첨가한 조건에서 37$^{\circ}C$에서 60 rpm으로 24시간 동안 흔들면서 경시적으로 시료를 취하여 잔존 펩타이드의 양을 HPLC법으로 정량하여 속도론적으로 비교 검토하였다. 이 연구에 사용한 효소억제제로는 아미노펩티다제의 억제제인 amastatin (AM), bestatin (BS). 엔케팔리나제 A의 억제제로 알려진 thiophan (TP), 엔케팔리나제 B의 억제작용이 있는 것으로 밝혀진 thimerosal (TM), metalloenzyme의 억제제인 에데트산나트륨 (EDTA) 등을 검토하였고 또 $\beta$-시클로덱스트린 유도체인 디메칠-$\beta$-시클로덱스트린과 2-히드록시프로필-$\beta$-시클로덱스트린이 펩타이드의 분해억제효과도 함께 검토하였다.

• Korean Journal of Veterinary Research
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• v.49 no.2
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• pp.113-119
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• 2009

Atrophic rhinitis (AR) is the one of important respiratory diseases and causes severe economic losses in pig industry. Severe attempts have been made to reduce the economic losses by preventing the disease. One of the methods is the spraying of antibiotics into nasal cavity of piglets. Recently, the efficacy of the spraying with kanamycin and gentamicin was reduced in the Korean swine industry. Therefore, the preventive methods have been required to be changed based on the antimicrobial susceptibility profiles of causative agents of swine AR. Based on the current situations of this disease, Bordetella (B.) bronchiseptica and Pasteurella (P.) multocida 4D were isolated from pigs with clinical signs of AR. The isolation rates of B. bronchiseptica and P. multocida 4D were 58.5% and 32.9%, respectively. In the antimicrobial susceptibility test, the bacteria were resistant to kanamycin and gentamicin which have been used as the spraying agents, but they were susceptible to amikacin. A new spraying agent was developed using amikacin using ${\beta}$-glucan and yakbaltag as supplementary agents. Field efficacy of the agent was carried out with different schedule. The results from this study suggested that the newly developed spraying agents might be helpful to prevent AR in swine.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.29 no.1
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• pp.61-65
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• 2016

Composites are materials that are widely used in industries such as automobile and aircraft. The composite material is required as a material for using in a high temperature environment as well as acting as a high pressure environment like the nozzle part of the ship. It is important to know the properties of composites. Result values obtained substituting the properties of matrix and fiber numerically have an large error compared with experimental value. In this study we utilize CASADsolver EDISON program for using Finite Element Method. Properties by substituting the fiber and Matrix properties of the composite material properties were compared with those measured in the experiment and calculated by the empirical properties.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.29 no.1 s.232
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• pp.103-109
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• 2005

Airflow in the nasal cavity of a normal Korean adult is investigated experimentally by tomographic PIV measurement. Knowledge of airflow characteristics in nasal cavities is essential to understand the physiology and pathology aspects of nasal breathing. Several studies have utilized physical models of the healthy nasal cavity to investigate the relationship between nasal anatomy and airflow. All of these researches on nasal airflow are under the condition of constant flow-rate. In this study, nasal cavity flow with the physiological period is investigated by tomographic PIV, for the first time. A pumping system that can produce the periodic flow is created. Thanks to a new method for the model casting by a combination of the rapid prototyping and curing of clear silicone, a transparent rectangular box containing the complex nasal cavity can be made for PIV, The CBC PIV algorithm is used for analysis. Phase-averaged mean and RMS velocity distributions are obtained for inspirational and expiration nasal airflows. The comparison with the constant flow case is appreciated. There exist many flow patterns depending on each phase.

• Journal of Clinical Otolaryngology Head and Neck Surgery
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• v.29 no.2
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• pp.254-258
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• 2018

The solitary fibrous tumor (SFT) is a mesenchymal neoplasm that is described as spindle-shaped tumor cells on a collagenous background originating from pleural tissues. Recently, extrapleural SFT has been reported in nearly all sites, including the sublingual gland, parotid gland, nasal cavity and paranasal sinuses. Complete surgical excision is primary treatment for SFT, but diagnosing SFT is not often made until immunohistochemical evaluation after surgical resection. We report that the patient, 45-year-old male, was considered as a case of inflammation polyp arising from left nasal cavity with initial biopsy, however, it has turned out to be SFT after surgical treatment.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.29 no.2
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• pp.79-82
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• 2018

Background and Objectives : Laryngeal contact granuloma is benign inflammatory disease induced by excessive mechanical contact of larynx such as endotracheal intubation, voice abuse, laryngeal microsurgery as well as laryngopharygeal reflux. Because it is caused by various risk factors, multiple treatment modalities are required. The purpose of study is to evaluate treatment effect of topical steroid through nasal cavity in contact granuloma. Materials and Method : Fifty-two patients were enrolled in this study with exception of intubation granuloma. Patients were classified with four groups (Proton pump inhibitor (PPI), Nasal steroid spray (SPR), PPI+SPR, Observation) according to treatment modality. Results : Patients who treated with PPI (Odds ratio 2.45, p=0.03) and combination of PPI and SPR (Odds ratio 2.88, p<0.01) had significantly better response than patients who not treated with medical therapy. Conclusion : Combination therapy of nasal steroid spray and PPI is effective for contact granuloma of larynx and considered as a treatment of choice rather than PPI only treatment.

• Composites Research
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• v.32 no.5
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• pp.222-228
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• 2019

The proton exchange membrane fuel cell (PEMFC) system has many potential uses as an environmentally friendly power source. Carbon fiber composite bipolar plates are highly corrosion resistant and have high specific strength and stiffness in acidic environments, however, the relatively low electrical conductivity is a major issue which reduces the efficiency of PEMFC. In this study, electrically conductive particles (graphite powder and carbon black) are applied to carbon-epoxy composite prepregs to reduce the electrical resistance of the bipolar plates. The electrical resistance and mechanical properties are measured using conventional test methods, and a unit cell performance evaluation of developed carbon composite bipolar plates is performed to compare with the conventional bipolar plate.