• Title/Summary/Keyword: SCF

Search Result 241, Processing Time 0.032 seconds

An Estimation of the Stress Concentration Factor for Mast Lug of Yacht with Different Shapes (해양레저용 요트의 마스트 러그 형상에 따른 응력집중계수 추정)

  • Roh, Ji-Sun;Oh, Dong-Jin;Kim, Myung-Hyun
    • Journal of Welding and Joining
    • /
    • v.30 no.1
    • /
    • pp.72-77
    • /
    • 2012
  • Recently, according to the increase of income and development of quality of life, the leisure industry has been developed. In particular, the interest of design and manufacture technology of leisure yacht has significantly increased. However, domestic market of leisure ships is currently in its initiating stage. So research and development for structural strength of leisure yacht need to be investigated. In this study, lug of yacht's mast which is known for a critical damage region is explicitly considered. This paper deals with the estimation of stress concentration factors (SCFs) for lug of yacht's mast depending on dimensions of lug using hot spot stress. Also, SCF formulae is suggested using parametric study.

Expression of Human Stem Cell Factor with Recombinant Baculovirus in BmN Cell Line and Silkworm

  • Xijie, Guo;Yongfeng, Jin;Mingguan, Yang;Yaozhou, Zhang
    • International Journal of Industrial Entomology and Biomaterials
    • /
    • v.4 no.1
    • /
    • pp.51-56
    • /
    • 2002
  • A recombinant transfer vector pBacSCF was constructed by inserting huamn stem cell factor (hSCF) cDNA into plasmid pBacPAK8. BmN cells were co-transfected with modified Bombyx mori, nuclear polyhedrosis virus (BmBacPAK) DNA and the recmbinant transfer vector to construct a recombinant baculovirus containing hSCE gene. DNA dot blotting and RNA dot blotting demonstrated that the hSCE gene was contained in the recombinant virus and transcribed. The recombinant baculovirus was infectious to BmN cells and to silkworm. SDS-PAGE analysis showed a specific band of expressed product in the extract of infected cells and in the heamolymph of infected larvae. Bioactivity of the recombinant hSCE was determined with W-1 cell line and MTT colorimetric method in synergy with interlukin-3 (IL-3). These results revealed that the hSCF gene was over-expressed in cultured cells and lavae of silkworm.

A Theoretical Study on Vibrational Predissociation Rates of Ne-$I_2$

  • 성정희;선호성
    • Bulletin of the Korean Chemical Society
    • /
    • v.19 no.5
    • /
    • pp.539-544
    • /
    • 1998
  • A new theoretical method, named the SCF-DWB-IOS approximation, is suggested to investigate the vibrational predissociation of triatomic van der Waals complexes. The meta stable vibrational excited states are described with SCF (self-consistent-field) approximation and the fragmented diatomic continuum states are determined by using IOS (infinite order sudden) approximation. The dissociation process itself is studied by using DWB (distorted wave Born) approximation. As a test case, the predissociation rates, rotational state distributions of products, and the lifetimes of vibrationally excited states of $Ne-I_2$ are all computed which are in reasonable agreements with other theoretical and/or experimental results. The suggested SCF-DWB-IOS approximation scheme is found to be a very simple but efficient theoretical tool to investigate the vibrational predissociation dynamics of small van der Waals complexes.

Inhibition of Stem Cell Factor- and Nerve Growth Factor-Induced Morphological Change by Wortmannin in Mast Cells

  • Kim, Hyung-Min;Moon, Young-Hoe;An, Nyun-Hyung
    • Archives of Pharmacal Research
    • /
    • v.22 no.2
    • /
    • pp.108-112
    • /
    • 1999
  • Recombinant murine stem cell factor (rmSCF) or recombinant murine nerve growth factor (rmNGF) induced the morphological change of large numbers of rat peritoneal mast cells (RPMC). We investigated the role of phosphatidylinositol $3^{l}-kinase$ (PI3-kinase) in receptors-mediated morphological change in RPMC. Exposure of RPMC to PI3-kinase inhibitor, wortmannin, before the addition of rmSCF and rmNGF antagonized those factors-induced morphological change. These results suggest that the PI3-kinase is involved in the signal transduction pathway responsible for morphological change following stimulation of rmSCF and rmNGF and that wortmannin blocks these responses.

  • PDF

SCFs in offshore two-planar tubular TT-joints reinforced with internal ring stiffeners

  • Ahmadi, Hamid;Imani, Hossein
    • Ocean Systems Engineering
    • /
    • v.12 no.1
    • /
    • pp.1-22
    • /
    • 2022
  • The majority of tubular joints commonly found in offshore jacket structures are multi-planar. Investigating the effect of loaded out-of-plane braces on the values of the stress concentration factor (SCF) in offshore tubular joints has been the objective of numerous research works. However, due to the diversity of joint types and loading conditions, a number of quite important cases still exist that have not been studied thoroughly. Among them are internally ring-stiffened two-planar TT-joints subjected to axial loading. In the present research, data extracted from the stress analysis of 243 finite element (FE) models, verified against available numerical and experimental data, was used to study the effects of geometrical parameters on the chord-side SCFs in two-planar tubular TT-joints reinforced with internal ring stiffeners subjected to two types of axial loading. Parametric FE study was followed by a set of nonlinear regression analyses to develop six new SCF parametric equations for the fatigue analysis and design of axially-loaded two-planar TT-joints reinforced with internal ring stiffeners.

Role of Stem Cell Factor on the Recruitment of Mast Cells in the Development of Liver Fibrosis Induced by Bile Duct Ligation in the Rat (담관 결찰에 의한 간섬유증 발생에서 비만세포 동원에 미치는 Stem Cell Factor의 역할)

  • Jekal, Seung Joo;Ramm, Grant A.
    • Korean Journal of Clinical Laboratory Science
    • /
    • v.36 no.2
    • /
    • pp.163-172
    • /
    • 2004
  • Mast cells (MCs) have been implicated in the pathogenesis of tissue fibrosis. However, the role of MC in the development of liver fibrosis has not been fully elucidated. Stem cell factor (SCF) is known to recruit MCs to the liver following injury as it induces mast cell proliferation, survival and differentiation from resident tissue precursors. This study examines the interaction between activated hepatic stellate cells (HSCs) and MCs in rat fibrotic liver, and SCF production by HSCs during culture in vitro. Rats were studied 4, 7, 14 and 21 days after bile duct ligation (BDL). Fibrogenesis was assessed by a measurement of collagen stained with sirius red F3B. Activated HSCs and MCs were identified by ${\alpha}$-smooth muscle actin (${\alpha}-SMA$) immunohistochemical and alcian blue staining and measured by a computerized image analysis system. SCF production was determined in rat HSC cultures using Western blotting. Mild fibrotic changes were noted in BDL rat livers as early as 4 days after induction of cholestasis. Significant expansion and organization of fibrous tissue has occurred in day 14 BDL rats which progressed to bridging fibrosis by day 21. In BDL rats, both a large number of activated HSCs and MCs were detected in portal tracts and fibrous septa. Both area of activated HSCs infiltration and density of MCs were significantly higher in all BDL group compared with Shams. In BDL rats, both areas of activated HSCs infiltration and density of MCs were no significant difference between day 4 and 7 and were significantly higher in day 14. However, the areas of activated HSCs infiltration were significantly lesser in day 21 and the densities of MCs were significantly higher in day 21 compared with day14 BDL. In BDL rats, both areas of activated HSCs infiltration and density of MCs were highly correlated with areas of fibrosis. Western blotting showed that SCF protein was consistently produced in activated HSCs by culture on plastic and freshly isolated HSCs expressed relatively little 30kD SCF compared to late primary culture activated HSCs (day 14) and passaged HSCs. These results suggest that HSCs activated in vitro produce SCF, and may play an important role in recruiting mast cells to the liver during injury and fibrosis.

  • PDF

Crystallization and Properties of Poly(ethylene terephthalate) in Supercritical Carbon Dioxide (초임계이산화탄소에서의 폴리에틸렌테레프탈레이트의 결정화와 성질)

  • 정용채;조재환
    • Proceedings of the Korean Fiber Society Conference
    • /
    • 2001.10a
    • /
    • pp.171-174
    • /
    • 2001
  • 초임계유체(supercritical fluid, SCF)는 친환경적 용매로서 고분자 합성과 기능화를 비롯하여 RESS(rapid expansion of supercritical solution)와 초임계염색 등의 섬유공정 분야에서 연구자들의 흥미로운 관심을 받아 오고 있다. 초임계유체는 기체와 액체의 중간적인 특성을 가지면서도 가스와 같이 우수한 확산력을 가지며 또한 아주 낮은 점도를 갖는다. SCF 중에서 비교적 온화한 조건(31.1℃의 임계온도, 73.8기압의 임계압력, Figure 1)에서 초임계상태를 가질 수 있는 이산화탄소가 가장 많이 이용되고 있는데 이는 자원이 풍부하며 쉽게 회수하여 사용할 수 있어 응용 면에서 유리하다. (중략)

  • PDF