• Title/Summary/Keyword: H-G model

Search Result 1,727, Processing Time 0.037 seconds

Analysis of the turbulent flow on the periodically arranged semi-circular ribs in a rectangular channel (사각채널 내 주기적으로 배열된 반원 리브 영향의 유동해석)

  • Lee, G.H.;Nine, Md.J.;Choi, S.H.;Jeong, H.M.;Chung, H.S.
    • Journal of Power System Engineering
    • /
    • v.15 no.2
    • /
    • pp.31-36
    • /
    • 2011

  • The flow characteristics on the periodically arranged semi-circular ribs in a rectangular channel for turbulent flow have been investigated numerically. The aspect ratio of the rectangular channel was AR=5, the rib height to hydraulic diameter ratio was 0.07 and rib height to channel height ratio was e/H=0.117. The v2-f turbulence model and SST k-${\omega}$ turbulence model were used to find the flow characteristics of near the wall which are suited for realistic phenomena. The numerical analysis results show turbulent flow characteristics and pressure drop at the near the wall as observed experimentally. The results predict that turbulent kinetic energy(k) is closely relative to the diffusion of recirculation flow, and v2-f turbulence model simulation results have a good agreement with experimental.

  • https://doi.org/10.9726/kspse.2011.15.2.031 인용 PDF KSCI

Effects of Immunostimulatory CpG-Oligodeoxynucleotides on Bronchial Asthma in Rat (백서 천식에서 면역 증강성 CpG 올리고 뉴클레오티드 투여의 효과)

  • Lee, Sin-Hyung;Kim, Je-Hyeong;Jeong, Hye-Cheol;Kim, Kyung-Kyu;Jung, Ki-Hwan;Kim, Byung-Gyu;Lee, Seung-Heon;Park, Sang-Myun;Sin, Cheol;Cho, Jae-Youn;Shim, Jae-Jeong;In, Kwang-Ho;Yoo, Se-Hwa;Kang, Kyung-Ho
    • Tuberculosis and Respiratory Diseases
    • /
    • v.50 no.1
    • /
    • pp.12-28
    • /
    • 2001

  • Background and Object : Immunostimulatory CpG-oligodeoxynucleotides (ISS CpG-ODN) up-regulate the $T_{H1}$-type immune response and down-regulate the $T_{H2}$-type response. This study was performed to investigate the immune response changes resulting from ISS CpG-ODN on bronchial hyperresponsiveness, eosinophilic inflammation and mucus hypersecretion in rat asthma. Materials and Methods : 10 normal controls(NC) and 26 asthmatic rats, which were generated by ovalbumin(OVA) sensitization and challenge, were studied. The asthmatic rats were randomized into 11 asthma controls(AC) and 15 in the asthma-CpG treatment group(CpG). The CpG group was administered ISS CpG-ODN intramuscularly and the AC group was administered a placebo(0.9% NaCl) on day 15 and 20. After CpG-ODN or placebo administration, we measured the IFN-${\gamma}$($T_{H1}$-type cytokine) and IL-4($T_{H2}$-type cytokine) levels in the bronchoalveolar lavage fluid(BALF), the specific airway resistance(sRaw), eosinophilic fraction in BALF, eosinophilic infiltration, goblet cell dysplasia and MUC5AC gene expression in the lung tissue. Results : In the BALF of the CpG group, the IFN-${\gamma}$ concentration was significantly high and the IL-4 concentration was significantly low when compared with the AC group. Both the sRaw and eosinophilic fraction, and infiltration into the BALF and lung tissue significantly lower in the CpG group when compared with the AC group. However, little difference in goblet cell dysplasia and MUC5AC gene expression was observed between the CpG group and the AC group. Conclusion : ISS CpG-ODN decreases bronchial hyperresponsiveness and eosinophilic inflammation in the rat asthma model through the up-regulation of the $T_{H1}$-type immune response with the down-regulation of the $T_{H2}$-type response. However, the effect of these immune response changes on mucus hypersecretion was is not remarkable in this study.

  • PDF

Adsorption of Pb and Cu from Aqueous Solution by β-Glucan Crosslinked with Citric Acid (베타글루칸과 구연산의 교차결합 바이오 폴리머 흡착제를 이용한 수용액내 납과 구리의 흡착)

  • Jeon, Han Gyeol;Kim, Kyoung-Woong
    • Economic and Environmental Geology
    • /
    • v.55 no.4
    • /
    • pp.367-376
    • /
    • 2022

  • One of biopolymer, β-glucan (BG) chains were crosslinked by citric acid under the heating condition for the adsorption of Pb and Cu ions in the aqueous solution. The variation of functional groups on BG itself and crosslinked β-glucan (CBG) with their surface adsorption characteristics were investigated by FTIR and SEM-EDX. Adsorption kinetic results showed that adsorption of Pb and Cu onto the CBG followed the pseudo-second-order kinetic model and intra-particle diffusion model. The Langmuir adsorption model was depicted better adsorption characteristics than the Freundlich model. The adsorption capacities of Pb and Cu onto the CBG estimated by the Langmuir model were 59.70 and 23.44 mg/g, respectively. This study suggested that CBG may act as an eco-friendly adsorbent for the adsorption of Pb and Cu in the aqueous solution.

  • https://doi.org/10.9719/EEG.2022.55.4.367 인용 PDF KSCI