Hanger로 보강된 스터드 접합부의 인장거동에 관한 실험적 연구

박휘규,김승훈,이리형,이용택,황홍순,이정희 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.1(구조계)

This paper presents the tensile behavior of the stud connection between reinforced concrete(RC) and steel members. Hanger reinforcements are placed around the studs to transfer the tensile loads to the opposite side of the concrete member. Six specimens, of which variables were arrangement details of hanger reinforcements and studs. Tensile test results show that hanger reinforcements are effective to increase tensile strength and ductility. Test tensile strengths of specimens are compared with the nominal strengths by ACI codes(ACI 318-02, ACI 349-99) and PCI 1999.

SALT-INDUCED CHLOROPLAST PROTEIN (SCP) is Involved in Plant Tolerance to Salt Stress in Arabidopsis

Yong Zhuang,Yangxuan Liu,Yuxiang Li,Ming Wei,Yuying Tang,Penghui Li,Zhijian Liu,Hui Li,Weizao Huang,Songhu Wang 한국식물학회 2019 Journal of Plant Biology Vol.62 No.6

Soil salinization threats the agricultural productionand food security worldwide. Salt stress induced plantsenescence and chloroplast degradation. However, it remainslargely unknown how the chloroplast-localized proteins affectplant response to salt stress. Here, we characterized a novelgene (At5g39520) in Arabidopsis, which is induced by saltstress and encodes a chloroplast-localized protein. Thus, thisgene was named SALT-INDUCED CHLOROPLAST PROTEIN(SCP). A T-DNA insertion mutant of SCP gene (scp-1)showed the enhanced tolerance to salt stress, as indicated bythe increased survival rates, fresh weights and chlorophyllcontents compared with wild type plants under salt treatment. Salt-induced leaf senescence was also delayed in scp-1 mutant. The scp-1 complementation line and SCP overexpressionlines displayed the hypersensitivity to salt stress. The qRTPCRanalysis indicated that the transcripts of CHLOROPLASTVESICULATION (CV), which mediates stress-inducedchloroplast degradation, were altered in scp-1 mutant andSCP overexpression lines. Taken together, our results suggestthat SCP gene plays a negative role in response to salt stress andhas potential application for genetic modification of improvingplant tolerance to salt stress.

Investigation of Fe <tex> $_{3}$</tex>O <tex> $_{4}$</tex> Core/Mesoporous SiO <tex> $_{2}$</tex> Shell Microspheres Based on Mössbauer Spectroscopy

Yong Hui Li,In-Bo Shim,Chul Sung Kim IEEE 2011 IEEE transactions on magnetics Vol.47 No.10

<P>The Fe<SUB>3</SUB>O<SUB>4</SUB> core/mesoporous SiO<SUB>2</SUB> shell (Fe<SUB>3</SUB>O<SUB>4</SUB>@SiO<SUB>2</SUB>) microspheres were prepared by a solvothermal reaction method. The crystal structure was determined to be cubic spinel with lattice constant a<SUB>0</SUB> of 8.395 Å for core Fe<SUB>3</SUB>O<SUB>4</SUB>. Based on transmission electron microscopy (TEM) measurements, the core of Fe<SUB>3</SUB>O <SUB>4</SUB> particle diameter is 300-500 nm and shell thickness of 50 nm. From the magnetic hysteresis curves measured under 10 kOe, magnetization of Fe<SUB>3</SUB>O<SUB>4</SUB> and Fe<SUB>3</SUB>O<SUB>4</SUB>@SiO<SUB>2</SUB> microspheres is determined to be 77.0 and 17.0 emu/g , respectively, at room temperature. The M-T curve confirmed that the magnetic moment transition temperature was around 110 K in Fe<SUB>3</SUB>O<SUB>4</SUB> and 32 K in Fe<SUB>3</SUB>O<SUB>4</SUB>@SiO<SUB>2</SUB>. The Mössbauer spectra of the samples were analyzed with three six-line hyperfine patterns. It is noticeable that from the Mössbauer absorption area ratio between A(8a) and B(16d) sites, the area ratio of sextet increases from 40:60 for Fe<SUB>3</SUB>O<SUB>4</SUB> to 56:44 for Fe<SUB>3</SUB>O<SUB>4</SUB>@SiO<SUB>2</SUB>, respectively. The Fe valence state of A site was determined to be ferric, and B (B<SUB>1</SUB>, B<SUB>2</SUB>) site was ferric (B<SUB>1</SUB> site) and ferrous (B<SUB>2</SUB> site) from the isomer shift values.</P>

Magnetic Properties of Sn<SUB>1-x</SUB>Fe<SUB>x</SUB>O₂ Thin Films and Powders Grown by Chemical Solution Method

Yong Hui Li,In-Bo Shim,Chul Sung Kim 한국자기학회 2009 Journal of Magnetics Vol.14 No.4

Iron-doped Sn1-xFexO₂ (x = 0.0, 0.05, 0.1, 0.2, 0.33) thin films on Si(100) substrates and powders were prepared by a chemical solution process. The x-ray diffraction (XRD) patterns of the Sn1-xFexO₂ thin films and powders showed a polycrystalline rutile tetragonal structure. Thermo gravimetric (TG) - differential thermal analysis (DTA) showed the final weight loss above 430 ℃ for all powder samples. According to XRD Rietveld refinement of the powders, the lattice parameters and unit cell volume decreased with increasing Fe content. The magnetic properties were characterized using a vibrating sample magnetometer (VSM) and Mossbauer spectroscopy. The thin film samples with x = 0.1 and 0.2 showed paramagnetic properties but thin films with x = 0.33 exhibited ferromagnetic properties at room temperature. Mossbauer studies revealed the Fe<SUP>3+</SUP> valence state in the samples. The ferromagnetism in the samples can be interpreted in terms of the direct ferromagnetic coupling of ferric ions via an electron trapped in a bridging oxygen deficiency, which can be explained using the Fcenter exchange model.

The Domain Ontology and Domain Rules Based Requirements Model Checking

LI Zong-yong,WANG Zhi-xu,ZHANG Ai-hui,Xu Yong 보안공학연구지원센터 2007 International Journal of Software Engineering and Vol.1 No.1

Many ontology-based methods have been proposed and applied in order to elicit system requirements correctly and unambiguously. However, most of ontologies in these methods are purely conceptual models. Furthermore, the domain knowledge base only captures domain concepts and neglects domain-restricted rules. If the requirements model violate these rules or contradict the usual business behavior, they become unreasonable. This paper suggests a formal approach to precisely describe ontology using description logic at first, and then model the integrity rules and derivation rules which restrict the business behavior. All the rules are represented in three aspects: syntax, semantics and visualization. Finally, the requirements model checking framework is provided combining domain ontology and domain rules, which makes the requirements elicitation process both guided by domain ontology and restricted by domain rules. Therefore, the acquired requirements would comply with both business needs and domain knowledge.

Investigation of cation distribution in single crystalline Fe₃₋_<i>x</i>Mn_<i>x</i>O₄ microspheres based on Mössbauer spectroscopy

Hui Li, Yong,Kouh, Taejoon,Shim, In-Bo,Sung Kim, Chul American Institute of Physics 2012 JOURNAL OF APPLIED PHYSICS - Vol.111 No.7

Investigation of the Ferromagnetic Properties of ^(57)Fe doped Tin(IV) Oxide Based on Mössbauer Spectroscopy

Yong Hui Li,고태준,김삼진,심인보,김철성 한국물리학회 2011 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.58 No.4

Diluted magnetic semiconductor Sn_(1−x)^(57)Fe_xO_2 (x = 0.005, 0.01, and 0.03) powders were prepared by using a sol-gel method. The crystal structure was found to be a rutile tetragonal structure with space group P42/mnm. From vibrating sample magnetometer measurements at room temperature, we observed an enhanced ferromagnetic behavior with increasing ^(57)Fe concentration. Mössbauer spectra were taken at various temperatures ranging from 4.2 K to room temperature. Room temperature Mössbauer spectra show a ferromagnetic phase with a sextet and a paramagnetic phase with a doublet, and an increasing area ratio of the ferromagnetic phase with increasing ^(57)Fe concentration. The isomer shift (δ) value was about 0.30 mm/s within the temperature range considered here, indicating that the Fe valence state was ferric. Interestingly, Mössbauer spectra for the x = 0.01 and 0.03 samples at 4.2 K showed 2-sextets and 1-doublet while the spectrum for the x = 0.005 sample at 4.2 K only shows 1-sextet and 2-doublets.

JCAD deficiency attenuates activation of hepatic stellate cells and cholestatic fibrosis

Li Xie,Hui Chen,Li Zhang,Yue Ma,Yuan Zhou,Yong-Yu Yang,Chang Liu,Yu-Li Wang,Ya-Jun Yan,Jia Ding,Xiao Teng,Qiang Yang,Xiu-Ping Liu,Jian Wu 대한간학회 2024 Clinical and Molecular Hepatology(대한간학회지) Vol.30 No.2

Background/Aims: Cholestatic liver diseases including primary biliary cholangitis (PBC) are associated with active hepatic fibrogenesis, which ultimately progresses to cirrhosis. Activated hepatic stellate cells (HSCs) are the main fibrogenic effectors in response to cholangiocyte damage. JCAD regulates cell proliferation and malignant transformation in nonalcoholic steatoheaptitis-associated hepatocellular carcinoma (NASH-HCC). However, its participation in cholestatic fibrosis has not been explored yet. Methods: Serial sections of liver tissue of PBC patients were stained with immunofluorescence. Hepatic fibrosis was induced by bile duct ligation (BDL) in wild-type (WT), global JCAD knockout mice (JCAD-KO) and HSC-specific JCAD knockout mice (HSC-JCAD-KO), and evaluated by histopathology and biochemical tests. In situ-activated HSCs isolated from BDL mice were used to determine effects of JCAD on HSC activation. Results: In consistence with staining of liver sections from PBC patients, immunofluorescent staining revealed that JCAD expression was identified in smooth muscle α-actin (α-SMA)-positive fibroblast-like cells and was significantly up-regulated in WT mice with BDL. JCAD deficiency remarkably ameliorated BDL-induced hepatic injury and fibrosis, as documented by liver hydroxyproline content, when compared to WT mice with BDL. Histopathologically, collagen deposition was dramatically reduced in both JCAD-KO and HSC-JCAD-KO mice compared to WT mice, as visualized by Trichrome staining and semi-quantitative scores. Moreover, JCAD deprivation significantly attenuated in situ HSC activation and reduced expression of fibrotic genes after BDL. Conclusions: JCAD deficiency effectively suppressed hepatic fibrosis induced by BDL in mice, and the underlying mechanisms are largely through suppressed Hippo-YAP signaling activity in HSCs.

Crystallographic and M¨ossbauer Studies of Sintered Nd-Fe-B Magnet

Yong Hui Li,임정태,김철성,안성용,최강룡,최문희 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.62 No.11

Nd-Ga-Febal.-Nb-B alloy with Nd2Fe14B structure was synthesized by using the strip casting method. The Nd-Ga-Febal.-Nb-B alloy retains the tetragonal structure with lattice constants a0= 8.802, and c0 = 12.215 ˚A. M¨ossbauer spectra were recorded at various temperatures ranging from 4.2 to 620 K. The Curie temperature (TC), and Debye temperature (ΘD) were determined to be TC = 613, and ΘD = 471.4 K, respectively. Each spectrum below TC was fitted with six subspectra of Fe sites (8j1, 8j2, 16k1, 16k2, 4c, and 4e) based on the occupancy of Fe ions probability distribution. The area ratios of subspectra at 4.2 K are 12.8, 12.8, 29.6, 29.1, 6.8,and 9.1%, respectively. The magnetic hyperfine fields (Hhf ) for the Fe sites decrease in the order Hhf (8j2) > Hhf (16k2) > Hhf (4c) > Hhf (16k1) > Hhf (8j1) > Hhf (4e).

Applied-Field Dependent Hyperfine Structure and Magnetic Properties of <tex> ${\rm Ni}_{0.8-x}{\rm Cu}_{x}{\rm Zn}_{0.2}{\rm Fe}_{2}{\rm O}_{4}$</tex>

Yong Hui Li,Sam Jin Kim,Sung Yong An,Chul Sung Kim IEEE 2011 IEEE transactions on magnetics Vol.47 No.10

<P>The crystal structure of Ni<SUB>0.8-x</SUB>Cu<SUB>x</SUB>Zn<SUB>0.2</SUB>Fe<SUB>2</SUB>O<SUB>4</SUB> (<I>x</I> = 0.2, 0.4, 0.6) sample is determined to be cubic spinel with space group <I>Fd</I>-3 m by Rietveld refinement. The lattice constant <I>a</I><SUB>0</SUB> increased linearly with the Cu concentration from <I>x</I> = 0.2 to 0.6. With increasing Cu concentration, the saturation magnetization and coercivity decreased from 101.3 emu/g, 112 Oe to 88.7 emu/g, 83 Oe, respectively, at 4.2 K. Ni and Cu ions in NiCuZn ferrite prefer octahedral sites (<I>B</I>) and Zn ions prefer tetrahedral sites (<I>A</I>). Based on the distribution probability, we have analyzed Mössbauer spectra measured at 4.2 K as 5 sets with six-lines. Hyperfine fields at <I>A</I> and <I>B</I> sites at 4.2 K with zero magnetic field were <I>H</I><SUB>hf</SUB>(<I>A</I>)=500 kOe, and <I>H</I><SUB>hf</SUB>(<I>B</I><SUB>0</SUB>) =545 kOe, <I>H</I><SUB>hf</SUB>(<I>B</I><SUB>1</SUB>) = 525 kOe , <I>H</I><SUB>hf</SUB>(<I>B</I><SUB>2</SUB>) = 516 kOe, <I>H</I><SUB>hf</SUB>(<I>B</I><SUB>3</SUB>) = 483 kOe, for <I>x</I> = 0.6. Applied-field Mössbauer spectra of Ni<SUB>0.8-x</SUB>Cu<SUB>x</SUB>Zn<SUB>0.2</SUB>Fe<SUB>2</SUB>O<SUB>4</SUB> were measured parallel to the γ-ray direction under 5 T at 4.2 K. Hyperfine field <I>H</I><SUB>hf</SUB>(<I>A</I>) at <I>A</I> site under 5 T was 516 kOe, larger than that under zero applied-field, and at <I>B</I> site the average value of hyperfine field 〈<I>H</I><SUB>hf</SUB>(<I>B</I>)〉 was 440 kOe, smaller than 〈<I>H</I><SUB>hf</SUB>(<I>B</I>)〉 = 517 kOe under zero applied-field, for <I>x</I> = 0.6 . Then the hyperfine field at <I>A</I> and <I>B</I> sites decreased with increasing Cu content <I>x</I> = 0.2 to 0.6. Also, we noticed that the second and fifth absorption lines of Mössbauer spectra completely disappeared above 1 T, indicating that the spins of Fe ions at <I>A</I> and <I>B</I> sites were collinear to the applied-field. The Fe valence state was determined to be ferric from the isomer shift values.</P>