• Title/Summary/Keyword: tapered

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The Eigenvalues and Their Relationships for the Rectangular Frame (4각형 골조의 고유치와 고유치 간의 관계)

  • Lee, Soo-Gon;Kim, Soon-Cheol;Song, Chang-Young;Song, Sang-Yong
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.9 no.3
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    • pp.139-150
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    • 2005
  • Finite element method is applied to the determinations of the two eigenvalues(the elastic critical load and the natural frequence of lateral vibrations) of single story-3 equal bay rectangular frame. The analysis parameters are taper parameter ${\alpha}$ for column, and beam span to column height ratio, ${\beta}$ and second moment area ratio of beam to column, ${\Upsilon}$. Support condition at the column base and sway condition at the column top are also considered in the stability analysis of frame. The changes in the coefficient of eigenvalue are represented by algebraic function of analysis parameter. The coefficients estimated by the proposed algebraic function show good agreement with those determined by finite element method, which suggest the design aid role of the proposed function. By increasing the column axial forces step by step, the corresponding frequencies are also determined, which makes one examine or confirm the relationship suggested by other studies.

A novel retentive type of dental implant prosthesis: marginal fitness of the cementless double crown type implant prosthesis evaluated by bacterial penetration and viability

  • Hong, Seoung-Jin;Kwon, Kung-Rock;Jang, Eun-Young;Moon, Ji-Hoi
    • The Journal of Advanced Prosthodontics
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    • v.12 no.4
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    • pp.233-238
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    • 2020
  • PURPOSE. This study aims to compare the marginal fitness of two types of implant-supported fixed dental prosthesis, i.e., cementless fixation (CL.F) system and cement-retained type. MATERIALS AND METHODS. In each group, ten specimens were assessed. Each specimen comprised implant lab analog, titanium abutment fabricated with a 2-degree tapered axial wall, and zirconia crown. The crown of the CL.F system was retained by frictional force between abutment and relined composite resin. In the cement-retained type, zinc oxide eugenol cement was used to set crown and abutment. All specimens were sterilized with ethylene oxide, immersed in Prevotella intermedia culture in a 50 mL tube, and incubated with rotation. After 48 h, the specimens were washed thoroughly before separating the crown and abutment. The bacteria that penetrated into the crown-abutment interface were collected by washing with 500 µL of sterile saline. The bacterial cell number was quantified using the agar plate count technique. The BacTiter-Glo Microbial Cell Viability Assay Kit was used to measure bacterial adenosine triphosphate (ATP)-bioluminescence, which reflects the bacterial viability. The t-test was performed, and the significance level was set at 5%. RESULTS. The number of penetrating bacterial cells assessed by colony-forming units was approximately 33% lower in the CL.F system than in the cement-retained type (P<.05). ATP-bioluminescence was approximately 41% lower in the CL.F system than in the cement-retained type (P<.05). CONCLUSION. The CL.F system is more resistant to bacterial penetration into the abutment-crown interface than the cement-retained type, thereby indicating a precise marginal fit.

Bronchiolitis Obliterans Organizing Pneumonia as the First Manifestation of Polymyositis (다발성근염의 선행증상으로 나타난 폐쇄성 세기관지염 기질화 폐렴)

  • Lee, Jong-Hoon;Son, Choon-Hee;Jeong, Won-Tae;Lee, Ki-Nam;Lee, Young-Hoon;Choi, Pil-Jo;Jeong, Jin-Sook;Lee, Chang-Hoon
    • Tuberculosis and Respiratory Diseases
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    • v.46 no.1
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    • pp.89-95
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    • 1999
  • Bronchiolitis obliterans organizing pneumonia (BOOP) preceding polymyositis is rare. In this report, a 40-year-old patient with fever, chillness, generalized myalgia and progressive exertional dyspnea, had bilateral interstitial infiltrates on chest radiograph. High-Resolution CT showed subpleural and peribronchial distribution of airspace consolidation. Open lung biopsy was consistent with BOOP. Prednisolone therapy led to improvement, but during tapering of prednisolone for 3 months to 30 mg, he complained of weakness of both lower legs. One month later, prednisolone was tapered to 15 mg a day, fever. chillness and generalized myalgia were recurred. He complained of weakness of both arms. The creatine kinase (CK) with MM isoenzyme, lactate dehydrogenase (LDH) and aspartate aminotransferase (AST) were elevated. Anti-Jo1 antibody was positive. Vastus lateralis muscle biopsy was compatible with polymyositis. After injection of methylprednisolone for 1 week, the patient became afebrile, the dyspnea resolved, the pulmonary infiltrates decreased, and the muscle strength improved. The serum CK, LDH, AST levels declined significantly. Patients with idiopathic BOOP should have follow-up for the possible development of connective tissue disorders including polymyositis.

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Sectorial Form UWB Antenna with a CPW-fed Uni-Planar (CPW 급전 단일 평면 부채꼴형 UWB 안테나 설계 및 제작)

  • Kim, Nam;Son, Gui-Bum;Park, Sang-Myeong
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.18 no.3 s.118
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    • pp.305-314
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    • 2007
  • In this paper, we suggested a CPW-fed UWB antenna with uni-planar sectoral structure. The area where radiation device face ground is designed to have the shape of tapered slot based on exponential function. We modified a rectangular bow-tie dipole structure antenna and thus formed a multi-resonant mode. From this, we expanded the impedance bandwidth and made a feature satisfying VSWR of less than 2 between $3.1\sim10.6GHz$. The test result showed that the return loss less than -10 dB was met in the full-band UWB system and maximum gain of $0.9\sim3.1dB$ was made with the half-power beamwidth of $40.1\sim89.9^{\circ}$ on XY plane(Theta, $Phi=90^{\circ}$) and the full band. By using CPW-fed structure with no ground on the back of the substrate, the suggested antenna is easy to design and its miniaturization is also possible.

Investigation of stiffening scheme effectiveness towards buckling stability enhancement in tubular steel wind turbine towers

  • Stavridou, Nafsika;Efthymiou, Evangelos;Gerasimidis, Simos;Baniotopoulos, Charalampos C.
    • Steel and Composite Structures
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    • v.19 no.5
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    • pp.1115-1144
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    • 2015
  • Current climate conditions along with advances in technology make further design and verification methods for structural strength and reliability of wind turbine towers imperative. Along with the growing interest for "green" energy, the wind energy sector has been developed tremendously the past decades. To this end, the improvement of wind turbine towers in terms of structural detailing and performance result in more efficient, durable and robust structures that facilitate their wider application, thus leading to energy harvesting increase. The wind tower industry is set to expand to greater heights than before and tapered steel towers with a circular cross-section are widely used as more capable of carrying heavier loads. The present study focuses on the improvement of the structural response of steel wind turbine towers, by means of internal stiffening. A thorough investigation of the contribution of stiffening rings to the overall structural behavior of the tower is being carried out. These stiffening rings are placed along the tower height to reduce local buckling phenomena, thus increasing the buckling strength of steel wind energy towers and leading the structure to a behavior closer to the one provided by the beam theory. Additionally to ring stiffeners, vertical stiffening schemes are studied to eliminate the presence of short wavelength buckles due to bending. For the purposes of this research, finite element analysis is applied in order to describe and predict in an accurate way the structural response of a model tower stiffened by internal stiffeners. Moreover, a parametric study is being performed in order to investigate the effect of the stiffeners' number to the functionality of the aforementioned stiffening systems and the improved structural behavior of the overall wind converter.

Combined Cytosine Arabinoside and Prednisolone Therapy for Meningoencephalitis of Unknown Etiology in 2 Dogs (원인불명의 수막뇌염을 보인 개에서 Cytosine Arabinoside와 Prednisolone으로 치료한 2례)

  • Kim, Tae-Ho;Seo, Kyoung-Won;Lee, Young-Heun;Hwang, Cheol-Yong;Lee, Young-Won;Youn, Hwa-Young
    • Journal of Veterinary Clinics
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    • v.27 no.4
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    • pp.462-467
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    • 2010
  • A Maltese (5-years old, castrated male) and a Yorkshire Terrier (8-years old, intact female) were referred to Seoul National University Hospital for Animals with ataxia, circling, depression and anorexia. It was suspected to meningoencephalitis of unknown etiology (MUE) based on neurological signs, magnetic resonance imaging findings, cerebrospinal fluid analysis and canine distemper virus antigen test. Immunosuppressive dose of corticosteroid was initially chosen to treat in two dogs. However, the clinical signs were relapsed and side effects had arisen including polyuria, polydipsia, calcinosis cutis, liver enzyme elevation, weight gain and abdominal distension. Combination therapy of cytosine arabinoside (CA) and prednisolone (PDS) was tried. With this combination, the clinical signs were resolved and the side effects were alleviated. The dose of PDS was tapered to 0.5 mg/kg q48h in one case and the PDS was discontinued in the other case. These cases suggested that combined CA and PDS therapy may be significantly useful for the treatment of MUE uncontrolled by PDS alone.

A case of steroid-induced psychosis in a child having nephrotic syndrome with toxic epidermal necrolysis (신증후군 환아에서 발생한 독성표피괴사용해 치료를 위해 사용된 고용량 스테로이드로 인한 정신질환 1례)

  • Kim, Sae Yoon;Lee, Jae Min;Park, Yong Hoon
    • Clinical and Experimental Pediatrics
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    • v.53 no.3
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    • pp.437-441
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    • 2010
  • Toxic epidermal necrolysis (TEN) and Stevens Johnson syndrome (SJS) are rare, life-threatening mucocutaneous -diseases, usually attributable to drugs and infections. Corticosteroids have been used in the management of TEN for the last 30 years. This remains controversial and is still much debated. TEN can occur despite administration of high doses of systemic corticosteroids. The psychiatric side effects of corticosteroids can include headache, insomnia, depression, and mood disorders with or without psychotic episodes. Steroid-induced psychosis is dealt with by tapering or discontinuing the steroid; antipsychotics are also sometimes used. We report a case of an 11-year-old boy who was admitted with TEN. He had also been diagnosed as having nephrotic syndrome in the past. Remission was achieved through induction therapy and by maintaining the use of steroids. After a full-dose intravenous dexamethasone for TEN, he showed psychotic symptoms. We diagnosed him as having steroid-induced psychosis. We tapered the steroid use and initiated an atypical antipsychotic medication, olazapine and intravenous immunoglobulin (IV-IG). His symptoms dramatically improved and he was discharged.

Competitive Adsorption for Binary Mixture of 4-Nitrophenol and Phenol on RSTA using GAC (GAC를 이용한 RSTA에서 Phenol과 4-Nitrophenol의 이성분계 경쟁흡착)

  • Lee, Seung-Mok;Kim, Dae-Hyun
    • Journal of Korean Society of Environmental Engineers
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    • v.22 no.4
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    • pp.723-731
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    • 2000
  • In recent years, the amount and number of synthetic organic compounds(SOCs) discharged from various industries has been increasing. Granular activated carbon(GAC) adsorption is one of the best available technology to remove SOCs from water supplies and wastewater. In this paper competitive adsorption for binary mixture of 4-nitrophenol and phenol on reverse stratified tapered adsorber(RSTA) using GAC was studied. Two isotherm experiments were conducted, one for phenol and the other for 4-nitrophenol. The phenol data of binary mixture isotherm were not fitted to Freundlich isotherm. The competitive adsorption increased significantly with decreasing carbon dose and increasing adsorbate concentration. The RSTA was found to provide an increase in breakthrough time when decreasing flow rate, increasing angle and injection layers. The performance enhancement provided by RSTA can be exploited in separation and in the purification of fluids.

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A STUDY ON THE SHAPE OF A CANAL PREPARED WITH PROFILES IN A CURVED CANAL (PROFILE을 이용한 만곡 근관 형성시 근관의 형태에 관한 연구)

  • Park, Han-Soo;Lee, Min-Koo;Kim, Jong-Jin;Lee, Jong-Yeop
    • Restorative Dentistry and Endodontics
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    • v.24 no.4
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    • pp.633-638
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    • 1999
  • The purpose of our study is to evaluate the ability of nickel-titanium(NiTi) files in maintaining the original curvature of a curved root canal during canal preparation. Curved canals on translucent resin blocks were prepared with Profiles and stainless steel files and they were placed at the platform which can reproduce the same position. The unprepared and prepared canal forms were accurately compared by double exposure technique of photography. The results were as follows : 1 NiTi files made a canal comparatively taper, but stainless steel files didn't make a canal taper, wicest at midportion and comparatively wide at a apical portion. 2. Canals preparations with no. 25 Profile.06 up to the working length were most excellent in taperness and in maintaining the original curvature. Canals prepared with no 30 Profile.06 up to the working length made a little outer transportation at a apical portion, but not severe. 3. Canal preparations with Profile GT were excellent in taperness and in maintaining the original curvature, but made more enlargement toward the inner side at the starting portion of the curvature. 4. Canal preparations with stainless steel files were not tapered and provided the largest transportation.

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Building up the foundation for the elderly apparel industry through the study on a clothes-sizing system of elderly obese males (노년 비만남성의 의복 사이즈체계 연구를 통한 실버 의류산업 활성화 기반 구축)

  • Seong, Ok jin;Kim, Sook jin
    • The Research Journal of the Costume Culture
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    • v.27 no.6
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    • pp.632-644
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    • 2019
  • This study presents an efficient clothes-sizing system for those experiencing obesity in old age with the aim of revitalizing the clothing industry for older obese people. The study targets 249 obese men aged 60 to 85 who satisfy a Rohrer index score of 1.6 or higher and a BMI (body mass index) of 25 or higher. Elderly obese males showed more obesity in the body based on the waist. In particular, those in their 60s were the most obese, and after reaching their 70s, characteristics of old age in which the stature was reduced and the limbs were tapered were shown. The clothes-sizing system was set to 5cm in stature, 5cm and 3cm in chest girth, 2cm in waist girth (omphalion), and 2cm in hip girth according to the KS standards. Through the two-way distribution of each section, the name of the section with a high distribution was given. Casual tops were selected from eight sizes, ranging from 155 to 170cm in stature and 95 to 105cm in chest girth. Suit top sizes were selected from eight sizes, ranging from 160 to 170cm in stature and 94 to 103cm in chest girth. Bottoms suggested 10 sizes distributed between 90 and 100cm in waist girth (omphalion) and 92 and 98cm in hip girth. According to the KS standards, the detailed size was divided into the basic part and the reference part.