• Title/Summary/Keyword: Wall-function

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Impact of Ash Deposit on Conversion Efficiency of Wall Flow Type Monolithic SCR Reactor (벽유동 방식 담체를 사용하는 SCR 촉매 반응기에서 재 퇴적이 변환 효율에 미치는 영향에 대한 연구)

  • Park, Soo-Youl
    • Journal of Power System Engineering
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    • v.17 no.1
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    • pp.27-35
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    • 2013
  • SCR (Selective Catalytic Reduction) on DPF (Diesel Particulate Filter) is a multi-functional after-treatment device which integrates soot filtration and DeNOx function into a single can. Because of its advantage in package and cost, the SCR on DPF is considered as a potential candidate for future application. It inherently employes wall flow type monolithic reactor so ash included in exhaust gas may deposit inside the inlet channel of this device. This study is intended to identify the impact of ash deposit on SCR reaction under wall flow type monolithic reactor. Simulation approach is used so relevant species transport equations for wall flow type monolith is derived. These equations can be solved together with momentum conservation equations and give solution for conversion performance. Both ash deposit and clean catalyst case are simulated and comparison of these two cases gives an insight for the impact of ash deposit on conversion performance. Ash deposit can be classified as ash layer and ash plug. and impact of ash deposit is described along with different morphology of ash deposit.

A Light and Electron Microscopical Study of Compatible and Incompatible Interactions between Phytophthora capsici and Tomato (Lycopersicon esculentum) (Phytophthora capsici 균주와 토마토의 친화적, 불친화적 상호작용에 대한 광학 및 전자현미경적 연구)

  • 황재순;황병국;김우갑
    • Korean Journal Plant Pathology
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    • v.10 no.2
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    • pp.83-91
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    • 1994
  • Stem tissues of tomato plants (cv. Kwanyang) inoculated with Phytophthora capsici were examined by light and electron microscopy to compare early cytological differences between comaptible and incompatible interactions of tomatoes with the fungus. Twenty four hours after inoculation, the compatible isolate S 197 colonized severely the epidermis, cortex, and xylem vessels of stem tissue, whereas only few fungal cells colonized the stem tissues inoculated with the incompatible isolate CBS 178.26. Fragmented plasma membrane, distorted chloroplast, degraded cell wall, remnants of host cytoplasm were early ultrastructural features of the damaged host cell observed both in the compatible and incompatible interaction, a number of vesicles were distributed in the space between fungal cell walls and plasma membrane. The degradation of host cell walls by P. capsici was more pronounced in the compatible than the incompatible interactions. The incompatible interactions of tomato cells with P. capsici were characterized by formation of host cell wall apposition in the cortical parenchyma cells, indicating that the apposition of electron-dense material from the host cell walls may function as a plant defense reaction to the fungus. The fungal cells encased by wall appositions had abnormal cytoplasm and separated plasma membranes. The haustorium which formed from the fungal hyphae did not further penetrate through the host wall apposition and cytoplasmic aggregation, especially in the incompatible reactions. In contrast, the haustorium of the compatible isolate S 197 was not encased by wall appositions.

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Damage assessment and performance-based seismic design of timber-steel hybrid shear wall systems

  • Li, Zheng;He, Minjuan;Li, Minghao;Lam, Frank
    • Earthquakes and Structures
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    • v.7 no.1
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    • pp.101-117
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    • 2014
  • This paper presents a reliability-based analysis on seismic performance of timber-steel hybrid shear wall systems. Such system is composed of steel moment resisting frame and infill wood frame shear wall. The performance criteria of the hybrid system with respect to different seismic hazard levels were determined through a damage assessment process, and the effectiveness of the infill wood shear walls on improving the seismic performance of the hybrid systems was evaluated. Performance curves were obtained by considering different target non-exceedance probabilities, and design charts were further established as a function of seismic weight. Wall drift responses and shear forces in wood-steel bolted connections were used as performance criteria in establishing the performance curves to illustrate the proposed design procedure. It was found that the presence of the infill wood shear walls significantly reduced the non-performance probabilities of the hybrid wall systems. This study provides performance-based seismic evaluations on the timber-steel hybrid shear walls in support of future applications of such hybrid systems in multi-story buildings.

Displacement-based design method for an energy-dissipation self-centering wall panel structure

  • Sisi Chao;Guanqi Lan;Hua Huang;Huiping Liu;Chenghua Li
    • Steel and Composite Structures
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    • v.51 no.3
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    • pp.289-304
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    • 2024
  • The seismic performance of traditional steel frame-shear wall structures was significantly improved by the application of self-centering steel-reinforced concrete (SRC) wall-panel structures in the steel frames. This novel resilience functionality can rapidly restore the structure after an earthquake. The presented steel frame with steel-reinforced concrete self-centering wall-panel structures (SF-SCW) was validated, indicating its excellent seismic performance. The seismic design method based on bear capacity cannot correctly predict the elastic-plastic performance of the structure, especially certain weak floors that might be caused by a major fracture. A four-level seismic performance index, including intact function, continued utilization, life safety, and near-collapse, was established to achieve the ideal failure mode. The seismic design method, based on structural displacement, was proposed by considering performance objectives of the different seismic action levels. The pushover analysis of a six-floor SF-SCW structure was carried out under the proposed design method and the results showed that this six-floor structure could achieve the predicted failure mode.

Development of the Chest Wall in Children with Cerebral Palsy according to GMFCS Levels (뇌성마비 아동의 대동작운동기능 수준에 따른 흉곽발달 양상)

  • Jung, Jee Woon;Ko, Joo Yeon
    • The Journal of Korean Physical Therapy
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    • v.25 no.5
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    • pp.246-251
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    • 2013
  • Purpose: The purpose of this study was to provide quantitative data regarding development of the chest wall in children with cerebral palsy (CP) according to Gross Motor Function Classification System (GMFCS) levels and age using the radiological image diameter measurement method. Methods: Subjects included 112 children with CP and 110 healthy children, All of the children underwent simple chest x-ray. The diameters of the upper chest ($D_{apex}$) and lower chest ($D_{base}$) were measured on the anteroposterior (AP) view of a chest x-ray, and the $D_{apex}$ to $D_{base}$ ratio was calculated. Chest wall ratios were compared among children with CP at GMFCS levels I ~ III, GMFCS levels IV and V, and healthy children. Results: The results showed significant differences between the upper and lower chest wall diameters of children with CP at GMFCS levels IV and V, and healthy children (F=4.54, p=0.01; F=3.20, p=0.04). Results of comparison between the chest wall ratios of children with CP and healthy children, showed that the upper chest walls of healthy children were significantly larger in children younger than 48 months (p<0.05), and both the upper and lower chest walls of healthy children were significantly larger compared to children with CP in children older than 48 months (p<0.05). Conclusion: Radiographic measurement for examination of chest wall development is relatively simple, and the results yield quantitative data on development of the chest wall for children with CP. In addition, therapeutic interventions may be considered based on the results.

Morphological Analysis of the Sinus Lateral Wall using Computed Tomography (전산화단층촬영법을 이용한 상악동 측벽의 형태학적 분석)

  • Kim, Yong-Gun
    • Journal of Dental Rehabilitation and Applied Science
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    • v.27 no.3
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    • pp.285-292
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    • 2011
  • The purpose of thise study was to measure the thickness of the sinus lateral wall using computed tomography (CT), and to find the most suitable vertical position for lateral window opening prior to sinus elevation. Thirty patients requiring sinus elevation had CT images taken with Philips Brilliance iCT. The thickness of the sinus lateral wall was measured according to its vertical position against the sinus inferior border, and its mean was calculated through three repeated measurements. When measured 2 mm above the sinus inferior border (SIB+2), the thickness of the sinus lateral wall was observed to be more than 2 mm. When measured 3 mm above the sinus inferior border (SIB +3), the sinus lateral wall was less than 2 mm in thickness. It is recommended that the lateral wall window be made 3 mm above the sinus inferior border when performing sinus elevation using the lateral approach.

Optimization of Angled Ribs for Heat Transfer Enhancement in Square Channel with Bleed Flow (유출홀이 설치된 정사각유로 내 열전달 향상을 위한 경사진 요철 최적설계)

  • Lee, Hyun;Kim, Kyung-Min;Lee, Dong-Hyun;Cho, Hyung-Hee
    • Proceedings of the KSME Conference
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    • 2007.05b
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    • pp.2384-2389
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    • 2007
  • The 2nd order response surface method (RSM) has been carried out to get optimum thermal design for enhanced heat transfer on square channel with bleed holes. The RSM was used as an optimization technique with Reynolds-averaged navier-stokes equation. Turbulence model for heat transfer analysis used RNG k-epsilon model. The wall function used enhanced wall function. Numerical local heat transfer coefficients were similar to the experimental tendency. Two design variables such as attack angle of rib (${\alpha}$), rib pitch-to-rib height ratio (p/e) were chosen. Operation condition considered bleeding ratio per bleed hole ($BR_{hole}$). A response surface were constructed by the design variables and operation condition. As a result, adjusted $R^2$ was more than 0.9. Optimization results of various objective function were similar to heat transfer in channel with and without bleed flow. But friction factor was lower than channel without bleed flow.

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Complex dielectric function of CdTe/GaAs thin films studied by spectroscopic ellipsometry (타원 분광기를 이용한 CdTe/GaAs 박막의 복소 유전함수에 관한 연구)

  • Jeen, Gwang-Soo;Jo, Jae-Hyuk;Park, Hyo-Yeol
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.15 no.4
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    • pp.157-161
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    • 2005
  • Spectroscopic ellipsomerty measurements of the complex dielectric function of the CdTe thin films grown on GaAs(100) substrates by hot wall epitaxy have been performed in 1.5${\~}$5.5 eV photon energy range at room temperature. The spectroscopic ellipsometer spectra revealed distinct structures at energies of the $E_l,\;E_1+{\Delta}_1$, and $E_2$ critical points. These energies were decreased with increasing thickness of CdTe thin films.

Knowledge Based Automated Boundary Detection for Quantifying of Left Ventricular Function in Low Contrast Angiographic Images (저대조 혈관 조영상에서 좌심실 기능의 정량화를 위한 지식 기반의 경계선 자동검출)

  • 전춘기;권용무
    • Journal of Biomedical Engineering Research
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    • v.17 no.1
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    • pp.109-120
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    • 1996
  • Cardiac function is evaluated quantitatively using angiographic images via the analysis of the shape change or the heart wall boundaries. To kin with, boundary defection or ESLV(End Systolic Lert Ventricular) and EDLV(End Diastolic Left Ventricular) is essential for the quantitative analysis of cardiac function. The boundary detection methods proposed in the past were almost semi-automatic. Intervention by a knowledgeable human operator was still required Of con, manual tracing of the boundaries is currently used for subsequent analysis and diagnosis. This method would not cut excessive time, labor, and subjectivity associated with manual intervention by a human operator. EDLV images have noncontiguous and ambiguous edge signal on some boundary regions. In this paper, we propose a new method for automated detection of boundaries in noncontiguous and ambiguous EDLV images. The boundary detection scheme which based on a priori knowledge information is divided into two steps. The first step is to detect the candidate edge points of EDLV using ESLV boundaries. The second step is to correct detected boundaries of EDLV using the LV shape. We developed the algorithm of modifying EDLV boundaries defined adaptive modifier. We experimented the method proposed in this paper and compared our proposed method with the manual method in detecting boundaries of EDLV. In the areas within estimated boundaries of EDLV, the percentage of error was about 1.4%. We verified the useflilness and obtained the satisfying results througll the experiments of the proposed method.

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Effect of the High Frequency Chest Wall Oscillation (HFCWO) on Pulmonary Function and Walking Ability in Stroke Patients

  • Kim, Beom-Ryong;Park, Jin
    • The Journal of Korean Physical Therapy
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    • v.29 no.2
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    • pp.50-54
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    • 2017
  • Purpose: This investigation aimed to determine the effects of treadmill training (TT) and high frequency chest wall oscillation (HFCWO) on pulmonary function and walking ability in stroke patients as well as propose an exercise program to improve cardiovascular function. Methods: Twenty hemiplegic stroke patients were randomized to either the control group (CG) (n=10) or the experimental group (EG), which received TT and HFCWO (n=10). Pulmonary function was quantitated using patient forced vital capacity (FVC) and forced expiratory volume at one second (FEV1) while walking speed was assessed by the 10m walking test (10MWT). Further, walking endurance was determined utilizing the 6-minute walk test (6MWT). Subjects of the EG performed the study protocol for 60 minutes, five times a week for six weeks; CG patients did not participate in regular exercise. To determine significance for the differences observed before and after exercise, within-group and between-group comparisons were conducted utilizing paired and independent t-tests, respectively, with the level of significance set at ${\alpha}=0.05$. Results: Within-groups, significant differences were observed in both FVC and FEV1 (p<0.01) following completion of the study protocol. Further, between-group comparisons demonstrated significant differences in both FVC (p<0.05) and FEV1 (p<0.01). Post-exercise, significant changes in the 10MWT and 6MWT score were observed between the EG and CG (p<0.01). Further, statistically significant differences were observed in 6MWT scores between-groups (p<0.05). Conclusion: The TT and HFCWO effectively improved pulmonary function and walking ability in subjects with stroke. The proposed program can be applied to stroke patients as a useful therapy.