• 제목/요약/키워드: Kappa distribution

검색결과 164건 처리시간 0.024초

철도터널 화재 유동에 사용되는 FDS code의 적용성 분석 (The Applicability Analysis of FDS code for Fire-Driven Flow Simulation in Railway Tunnel)

  • 장용준;박원희
    • 한국철도학회논문집
    • /
    • 제10권2호
    • /
    • pp.224-230
    • /
    • 2007
  • The performance and applicability of FDS code is analyzed for flow simulation in railway tunnel. FDS has been built in NIST(USA) for simulation of fire-driven flow. RANS and DNS's results are compared with FDS's. AJL non-linear ${\kappa}-{\epsilon}$[7,8] model is employed to calculate the turbulent flow for RANS. DNS data by Moser et al.[9] are used to prove the FDS's applicability in the near wall region. Parallel plate is used for simplified model of railway tunnel. Geometrical variables are non-dimensionalized by the height (H) of parallel plate. The length of streamwise direction is 50H and the length of spanwise direction is 5H. Selected Re numbers are 10,667 for turbulent flow and 133 for laminar low. The characteristics of turbulent boundary layer are introduced. AJL model's predictions of turbulent boundary layer are well agreed with DNS data. However, the near wall turbulent boundary layer is not well resolved by FDS code. Slip conditions are imposed on the wall but wall functions based on log-law are not employed by FDS. The heavily dense grid distribution in the near wall region is necessary to get correct flow behavior in this region for FDS.

연속흐름 반응기에서 광촉매 반응에 의한 VOC 물질제거 특성에 대한 수치적 연구 (A Numerical Analysis of the Abatement of VOC with Photocatalytic Reaction in a Flow Reactor)

  • 최우혁;김창녕;정석진
    • 설비공학논문집
    • /
    • 제13권7호
    • /
    • pp.637-646
    • /
    • 2001
  • VOC(Volatile Organic Compound) removal characteristics in continuous flow reactors have been numerically investigated. The photocatalytic reaction have been simulated with the binding constant and the reaction rate constant obtained from experimental data for the constant-volume batch reactor, and then VOC abatement in continuous flow reactors with the same conditions as those of batch reactor has been analyzed. The standard 4\kappa-\varepsilon$ model and mass conservation equation have been employed for numerical calculation, and heterogeneous reaction rate has been used in terms of the boundary condition of the conservation equation. in the case of the continuous flow reactor, reaction characteristics have been estimated with various inlet velocities and with different number of baffles. The result shows that the concentration distribution and flow patterns are strongly affected by the inlet velocity, and that with the increased inlet velocity, VOC removal rate is increased, while removal efficiency is decreased. This result may be useful in the design of reactors with improved VOC removal efficiency.

  • PDF

CFD를 이용한 풍향에 따른 스마트무인기 흡기구 성능 변화 예측 (Prediction of Performance Change for the Intake system of Smart UAV With Freestream Wind Direction Using CFD Analysis)

  • 정용운;전용민;양수석
    • 한국전산유체공학회:학술대회논문집
    • /
    • 한국전산유체공학회 2004년도 추계 학술대회논문집
    • /
    • pp.95-99
    • /
    • 2004
  • The developing Smart UAV in KARI supposes high speed flight as like a conventional plane, as well as vertical takeoff and landing as like a helicopter. Therefore, the air intake system should be designed to provide the sufficient air flow to the engine and the maximum possible total pressure recovery at the engine intake screen over a wide range of flight conditions. For this purpose, we designed the intake system using a pilot type intake model and plenum chamber In this paper, we designed the intake model and analyzed the performance of designed intake system using the general-purpose commercial CFD code, CFD-ACE+ For 3-D calculation, we generated mesh using the unstructured gird and used $\kappa-\epsilon$ turbulence model. The analysis results of the total pressure variation and the velocity distribution was illustrated in this paper. The pressure recovery and distortion coefficient at a plane coincident with the compressor inlet were calculated and streamline variation through the intake system was investigated at the worst condition as well as the standard flight condition.

  • PDF

The protective effect of Prunella vulgaris ethanol extract against vascular inflammation in TNF-α-stimulated human aortic smooth muscle cells

  • Park, Sun Haeng;Koo, Hyun Jung;Sung, Yoon Young;Kim, Ho Kyoung
    • BMB Reports
    • /
    • 제46권7호
    • /
    • pp.352-357
    • /
    • 2013
  • Atherosclerosis, which manifests as acute coronary syndrome, stroke, and peripheral arterial diseases, is a chronic inflammatory disease of the arterial wall. Prunella vulgaris, a perennial herb with a worldwide distribution, has been used as a traditional medicine in inflammatory disease. Here, we investigated the effects of P. vulgaris ethanol extract on TNF-${\alpha}$-induced inflammatory responses in human aortic smooth muscle cells (HASMCs). We found that P. vulgaris ethanol extract inhibited adhesion of monocyte/macrophage-like THP-1 cells to activated HASMCs. It also decreased expression of intercellular adhesion molecule-1, vascular cell adhesion molecule-1, E-selectin and ROS, No production in TNF-${\alpha}$-induced HASMCs and reduced NF-${\kappa}B$ activation. Furthermore, P. vulgaris extract suppressed TNF-${\alpha}$-induced phosphorylation of p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated kinase (ERK). These results demonstrate that P. vulgaris possesses anti-inflammatory properties and can regulate TNF-${\alpha}$-induced expression of adhesion molecules by inhibiting the p38 MAPK/ERK signaling pathway.

초크랄스키법에 의한 8인치 실리콘 단결정 성장시 비대칭 커스프자장의 영향에 관한 연구 (A numerical study on the effects of the asymmetric cusp magnetic field in 8 inch silicon single crystal growth by Czochralski method)

  • 이승철;정형태;윤종규
    • 한국결정성장학회지
    • /
    • 제6권1호
    • /
    • pp.1-10
    • /
    • 1996
  • 초크랄스키법에 의한 8언치 실리콘 단결정 성장시 커스프자장의 영향에 관한 수치 해석적 연구를 행하였다. 액상실리콘의 유동에 대한 모렐은 저레이놀즈수 모렐을 사용하였다. 대칭커스프자장은 유션의 강도를 감쇄하였고, 특히 도가니 벽면 근처에서의 유동의 감쇄효과가 현저하였다. 결정으로 혼업되는 산소의 농도는 인가되는 커스프자장의 증가에 따라 감소하였다. 그리고, 결정으로 혼업되는 산소농도의 균일성은 향상되었다. 비대칭커스프 자장은 결정으로 혼 입되는 산소의 농도를 중가시켰지만, 반경방향의 산소농도의 분포는 일정하게 유지되었다. 대칭 과 비대청 커스프자장의 적절한 조합을 행하면 축방향으로 일정한 산소의 분포를 갖는 적절한 조업조건이 도출될 것으로 예상된다.

  • PDF

Mouse의 십이지장 점막 염증에 대한 사삼맥문동탕의 면역반응 연구 (The Effects of Sasammaickmoondong-tang against Duodenal Mucosal Lesions)

  • 임성우;최준혁
    • 대한한방내과학회지
    • /
    • 제24권2호
    • /
    • pp.300-314
    • /
    • 2003
  • Objectives : This study was carried out to investigate the effects of Sasammaickmoondong-tang(SME) on duodenal mucosal lesions induced by indomethacin in mouse. Methods : The normal group is that no inflammation elicitated mouse. Control group is that gastro-inflammation elicitated mouse. Sample group is that SME administered mouseice after gastro-inflammation elicitation. Results : In the common morphology and histochemical change, control group was observed various injury-mucous surface cell, micro-villi, paneth cell, surface epithelial cell, goblet cell-by hemorrhagic erosion, while sample group was as same as normal group. In the immunohistochemical change, the distributions of COX-1, Bcl-2, and BrdU treated with SME noticeably increased than control group(p<0.05). The distributions of TUNEL, $NF-{\kappa}B$, COX-2, $IL-2R-{\alpha}$, NK-1.1, ICAM-1, and CD11b/18 treated with SME noticeably decreased than control group(p<0.05). And the distribution of SBA was as same as normal group. Conclusion : According to the above results, it is supposed that Sasammaickmoondong-tang is applicable to duodenal mucosal lesions.

  • PDF

시계열 고해상도 항공영상을 이용한 소나무재선충병 감염목 탐지 - 강원대학교 학술림 일원을 대상으로 - (Detection of Pine Wilt Disease tree Using High Resolution Aerial Photographs - A Case Study of Kangwon National University Research Forest -)

  • 박정묵;최인규;이정수
    • 한국지리정보학회지
    • /
    • 제22권2호
    • /
    • pp.36-49
    • /
    • 2019
  • 본 연구는 강원대학교 학술림을 대상으로 현장조사 기반(Field Survey Based)에 의한 감염목(FSB_감염목)과 객체분류기반(Object Classification Based)에 의한 감염목(OCB_감염목)을 추출하고 감염목에 대한 공간적 분포특성 및 발생강도 평가를 목적으로 하였다. OCB 최적 가중치는 Scale 11, Shape 0.1, Color 0.9, Compactness 0.9, Smoothness 0.1로 선정되었으며, 전체 분류정확도는 약 94%, Kappa 계수는 0.88로 매우 높았다. OCB_감염목 지역은 약 2.4ha로 전체 면적의 약 0.05% 발생하였다. OCB_감염목와 FSB_감염목의 임분구조 분포특성 및 지형 지리적 요인을 비교 하면, OCB_감염목 영급은 IV영급의 분포비율이 약 44%로 가장 높았으며, FSB_감염목의 영급도 IV영급의 분포비율이 약 55%로 가장 높았다. OCB_감염목의 IV영급 비율은 FSB_감염목보다 약 11% 낮았다. OCB_감염목 경급은 소경목과 중경목이 약 93%로 대부분을 차지한 반면, FSB_감염목 경급은 중경목과 대경목이 약 87%로 전체 대상지의 경급 분포와 상이하였다. 한편, OCB_감염목 표고 분포비율은 401-500m에서 약 30%로 가장 높은 반면, FSB_감염목은 301-400m에서 약 45%로 상이하였으며, 임도로부터 접근성 분포 비율은 OCB_감염목과 FSB_감염목 모두 100m이하에서 각각 약 24%와 31%로 가장 높아 임도로부터 접근성이 높을수록 감염목이 높았다. OCB_감염목 핫스팟은 31임반과 32임반으로 영급과 경급이 높은 지역에서 높게 분포하였다.

호마자 추출물이 NC/Nga 생쥐의 아토피 피부염에 미치는 영향 (Therapeutic Effects of Sesamum Indicum Extracts on Atopic Dermatitis-Like Skin Lesions of NC/Nga Mouce)

  • 김윤희;이혜림
    • 대한한방소아과학회지
    • /
    • 제29권4호
    • /
    • pp.39-66
    • /
    • 2015
  • Objectives The purpose of this study is to investigate the effects of Sesamum indicum extracted (SEI) on atopic dermatitis in an in-vitro and in-vivo experiment using a MC/9 murine mast cells and a NC/Nga mouse. Methods In-vitro experiment, IL-4, IL-5, IL-6, IL-13, TNF-${\alpha}$ and GM-CSF mRNA expression were evaluated by Real-time PCR, IL-13, MIP-$1{\alpha}$ production by ELISA and manifestations of NFAT-1, NFAT-2, c-jun, c-fos, NF-${\kappa}B$ p65 transcription factors by western blotting. In-vivo experiment, we measured WBC, Eosinophil, Neutrophil, and serum IL-5, IL-13 in NC/Nga atopic dermatitis mouse, IL-5, IL-13, IFN-${\gamma}$, IL-4 in the spleenocyte culture supernatant by ELISA, the absolute cell numbers of CD4+, CD8+, +Gr-1+CD11b, B220+CD23+ in the axillary lymph node (ALN), peripheral blood mononuclear cells (PBMCs) and dorsal skin tissue, IL-5, IL-13 by Real-time PCR, the distribution of tissue inflammation and cellular infiltration by H&E and toluidine blue. Results SEI decreased IL-4, IL-5, IL-6, IL-13, GM-CSF, TNF-${\alpha}$ mRNA expression, IL-13, MIP-$1{\alpha}$ production and the expression of transcription factors including NFAT-1, c-jun, NF-${\kappa}B$ p65 in MC/9 murine mast cells. SEI orally administration decreased cell number of WBC, Eosinophil, the level of serum IgE, total cell number of ALN and dorsal skin tissue, absolute cell number of CD4+, CD8+, B220+CD23+ in the ALN. SEI orally administration also increased absolute cell number of CD8+/CD3+ and decreased Gr-1+/CD11b+ in PBMCs, decreased CD4+ in dorsal skin tissue, inhibited IL-5, IL-13 mRNA expression. Infiltration levels of inflammatory immune cells, mast cells and thickness of epidermis decreased in dorsal skin tissue. Conclusions SEI can regulate allergic inflammatory response suppressed the gene expression and production of cytokines that mediate allergic reactions, and will be able to be effectively utilized in the treatment of atopic dermatitis future.

사상체질진단표(四象體質診斷表) 및 망진(望診), 설진(舌診)에 관한 연구(硏究) (A Study on the Sasang Constitutional Checkup List and Inspection Diagnosis of Face and Tongue)

  • 김종채;최민기;정운기;신우용;김선형;유준상
    • 사상체질의학회지
    • /
    • 제19권3호
    • /
    • pp.156-175
    • /
    • 2007
  • 1. Objectives and Methods This study was performed to know the relationship between Sasang Constitution and characteristics of ordinary symptoms, inspection diagnosis of face and tongue. There were 666 participants(280 men and 386 women) who answered Sasang Constitutional Checkup list and were taken pictures of faces and tongues. Sasang Constitution was diagnosed by only PSSC(Phonetic System for Sasang Constitution). Distribution of Sasang Constitution and X2 test, kappa value for agreement were calculated using SPSS 10.0. 2. Results From characteristics of ordinary symptoms' point of view, Taeeumin had loud voices, big body shapes and easily sweated themselves. They felt good after sweating and had warm hands and feet. And their upper back, shoulders and chest were, they thought, well developed. They were apt to have meals quickly and overeat themselves. Soyangin and Soeumin had thin body shapes and were difficult to sweat themselves and felt powerless after sweating. They had cold hands and feet. Especially, Soeumin was apt to have meals slowly and a little amounts. They walked so fast. Soyangin was introvert and had developed their abdomen and waist. 'Looking heavy and steady' was higher in Taeeumin, 'delicate and modest' was higher in Soeumin(42.8%) and Soyangin(36.1 %) in first impression. It was thought to be difficult to discriminate Soyangin from Soeumin in first impression and make a notion of right Soyangin's first impression. Soyangin had pinky tongue color and little tongue fur whereas Soeumin had red tongue color and whitish tongue fur. Taeeumin had whitish tongue fur too. 3. Conclusions To diagnose Sasang Constitution much effectively, PSSC results and comprehensive Sasang Constitutional Checkup list extracted from effective Questionnaire items and Face and Tongue Inspection Diagnosis are thought to be needed.

  • PDF

백선피(白鮮皮) 추출물이 DNCB로 유발된 NC/Nga 생쥐의 아토피 피부염에 미치는 영향 (The Effects of Dictamni Radicis Cortex Extracts on DNCB Induced Atopic Dermatitis-like Skin Lesions of NC/Nga Mouse)

  • 이윤실;한재경;김윤희
    • 대한한방소아과학회지
    • /
    • 제28권4호
    • /
    • pp.1-29
    • /
    • 2014
  • Objectives Dictamni Radicis Cortex extracts (DRC) has been known to suppress allergic reaction, however the cellular target of DRC and its mode of action remain unclear. The purpose of this study is to investigate the effects of Dictamni Radicis Cortex extracts on DNCB induced atopic dermatitis-like skin lesions of NC/Nga mouse. Methods This study was designed to investigate the effects of DRC extract in the DNP-IgE-induced activation of MC/9 murine mast cell lines in vitro and in the DNCB-induced activation of NC/Nga mouse in vivo. For this investigation, We examined IL-4, IL-5, IL-6, IL-13, TNF-${\alpha}$ and GM-CSF mRNA expression by Real-time PCR, IL-13, MIP-$1{\alpha}$ production by ELISA analysis and manifestations of NFAT1, NFAT2, AP-1 and NF-${\kappa}B$ p65 transcription factors by western blotting in vitro. Then, we examined WBC, eosinophil and neutrophil in NC/Nga mouse, IL-5, IL-13 in serum, IFN-${\gamma}$, IL-4 in the spleenocyte culture supernatant, the absolute cell numbers of $CD4^+$, $CD8^+$, $^+Gr-1^+CD11b$, $B220^+CD23^+$ in the ALN, PBMCs and dorsal skin, IL-5, IL-13 in the dorsal skin by Real-time PCR and the distribution of mast cells by H&E and toluidine blue. Results In vitro the mRNA expression of IL-4, IL-5, IL-6, IL-13, TNF-${\alpha}$, GM-CSF and IL-13, MIP-$1{\alpha}$ production by ELISA analysis were completely abolished by DRC and the western blot analysis decreased the expression of mast cell-specific transcription factors including NFAT-1, NF-${\kappa}B$ p65. In vivo DRC oral adminstration also decreased the counts of WBC, eosinophils and inflammatory cytokines such as IL-13 and IgE in the serum. DRC oral adminstration elevated IL-4 level in the spleenocyte culture supernatant. DRC oral adminstration decreased total ALN cells, total skin cells, cell numbers of $CD4^+$, $B220^+CD23^+$ in the ALN, $^+Gr-1^+CD11b$ in the PBMCs and $CD4^+$, $CD8^+$ in the dorsal skin. The mRNA expression of IL-5, IL-13, thickness of epidermis, inflammation immune cells and mast cells were abolished by DRC in the dorsal skin. Conclusions Histological examination showed that infiltration levels of immune cells in the skin of AD-induced NC/Nga mouse were much improved by DRC oral adminstration. These results, therefore, suggest that DRC can regulate molecular mediators and immune cells that are functionally associated with atopic dermatitis induced in NC/Nga mouse, and may play an important role in recovering AD symptoms.