200 GeV/핵자 유황이온과 핵건판핵의 충돌에 의해 생성된 헬륨 파쇄핵의 극한파쇄 연구

김동철,송진섭,윤천실,정성헌,박인곤,김종오,김철수,김태연,이승희,조재희,천병구,김재률,김준원,김태익,박명렬,장한일,임인택 慶尙大學校 기초과학연구소 1992 基礎科學硏究所報 Vol.8 No.-

고에너지 중이온 원자핵과 핵건판의 충돌에서, 200GeV/핵자 유황이온에 의해 생성된 파쇄 헬륨핵(Z=2)의 실험실계의 방출각 분포는 표적핵에 무관한 회귀공식. dN=exp[a+k exp(η-y_b)]d[exp(η-y_b)]로 잘 표현된다. 여기에서 의사신속도 η=-ln[tan(θ/2)]이고, y_b는 실험실계의 입사입자(^32S)의 신속도이다. 이 공식에 의한 적합에서 k=-0.057±0.008로 얻어진다. 즉, 핵건판과 고에너지 중이온의 충돌에서 파쇄 헬륨핵의 exp(η-y_b)의 분포는 "극한파쇄" 현상을 잘 설명하고 있다. The angular distribution of emission angle θ of helium (Z=2) produced in the collisions of incident particles of 200 GeV/nucleon ^32S in nuclear emulsion is well expressed by dN=exp[a+k exp(η-y_b)]d[exp(η-y_b)] where the pseudorapidity is η=-ln[tan(θ/2)], the laboratory system primary rapidity is y_b, and k=-0.057+0.008. The shape of this frequency of occurrence distributions in terms of exp(η-y_b) attests to the validity of the concept of "limiting fragmentation" for helium projectile fragments produced in the projectile fragmentation regions of heavy ion collisions in nuclear emulsion.

A study of nerve agent model organophosphonate binding with manganese-A₂B-corrole and -A₂B₂-porphyrin systems

Kim, K.,Kim, I.,Maiti, N.,Kwon, S.J.,Bucella, D.,Egorova, O.A.,Lee, Y.S.,Kwak, J.,Churchill, D.G. Pergamon Press 2009 Polyhedron Vol.28 No.12

Herein the synthesis and binding studies of novel trans-A<SUB>2</SUB>B-corrole and trans-A<SUB>2</SUB>B<SUB>2</SUB>-porphyrin derivatives are presented in comparing manganese(III)-organophosphonate (OP) binding (e.g., M<SUP>n+</SUP>←O?PR(OR)<SUB>2</SUB>) capabilities. H<SUB>3</SUB>(PFP-VC) [PFP-VC=5,15-di(pentafluorophenyl)-10-(3-vinylphenyl)corrolate] was synthesized by way of literature procedures and was characterized by a variety of 2-D NMR spectroscopic techniques and single-crystal X-ray diffraction. These compounds represent the first example of 3-vinyl-phenyl-containing meso-substituted corroles or porphyrins. Mn(PFP-VC) (3) was treated separately with (CH<SUB>3</SUB>CH<SUB>2</SUB>O)<SUB>2</SUB>P?O(C<SUB>3</SUB>H<SUB>6</SUB>NMe<SUB>2</SUB>), (C<SUB>4</SUB>H<SUB>9</SUB>O)<SUB>2</SUB>P?O(Me), (C<SUB>2</SUB>H<SUB>5</SUB>O)<SUB>2</SUB>P?O(CH<SUB>2</SUB>COCH<SUB>3</SUB>), (CH<SUB>3</SUB>CH<SUB>2</SUB>O)<SUB>2</SUB>P?O(Me), to give 1:1 adducts, as determined by UV-Vis spectroscopy (Job Plot), giving a red shift; Ph<SUB>3</SUB>P?O, was also found to bind, but very weakly. The trans-A<SUB>2</SUB>B<SUB>2</SUB>-porphyrin analogue Mn(PFP-VP) (4) was also prepared by way of a literature procedure; related binding studies gave 1:1 organophosphonate-Mn(PFP-VP) adducts (Job Plot). A clean blue shift occurred for the Mn-porphyrins at higher organophosphonate loadings (K<SUB>a</SUB> values: 6.7 (0.9)-11.9 (0.4)M<SUP>-1</SUP>). DFT geometry optimizations of O?P(OMe)<SUB>2</SUB>Me binding and formal Mn-O or P-O cleavage products in the unsubstituted neutral Mn-corrolato and -porphyrinato systems with a range of metal-based spin states revealed greatest stability in formal phosphoryl oxygen binding (energies: 11-13kcal/mol) for the Mn-corrole (singlet); the Mn-porphyrin (sextet) was also quite stable.

돼지 卵子의 透明帶에 대한 單一클론抗體生産과 그 特性에 關한 硏究

金鐘培,劉永春,金昌圭,權五中,鄭盛元,鄭吉生 건국대학교 동물자원연구센터 1991 動物資源硏究誌 Vol.16 No.-

本 試驗은 單一클론抗體의 강한 特異性과 抗體性質의 不變性을 이용하여 發生學的 側面에서 哺乳動物 卵子의 透明帶의 機能과 構造를 이해하고, 또한 種特異的인 精子 受容體의 存在 및 生化學的 構造를 규명하기 위한 기초연구로서, 돼지 卵子의 透明帶를 免疫原으로 하여 BABL/c 생쥐로부터 單一클론抗體를 생산하고 그 특성을 구명하였던 바 다음과 같은 결과를 얻었다. 1) 3마리의 BABL/c 생쥐(YⅠ, YⅡ, ZI)에 돼지卵子의 透明帶를 免疫化하고, 複合抗體 生成을 확인한 후 생쥐의 脾臟細胞와 Myeloma(SP2/O-Ag14)를 polyethylene glycol를 融合을 실시한 결과 각각 25.8%, 54.5% 그리고 59.7%의 融合效率을 나타내었으며, ELISQ에 의해 陽性反應을 조사한 결과 각각 17.3%, 32.6% 그리고 6.2% 陽性反應 效率을 나타내었다. 2) YI에서 강한 陽性反應을 보인 6개의 well에 대한 cloning을 실시하고 抗體檢證을 행한 결과 20.8% ∼ 48.4%의 Cloning效率과 54.6% ∼ 82%의 陽性反應 效率을 나타내었다. 3) 강한 陽性反應을 나타낸 항체에 대해 sandwich ELISA法에 의해 isotype을 決定하였던바 2E93C(YⅠ), 3E83E7(YⅠ), 4E3(YⅡ)각각 IgG₂b, IgG₂a, IgM으로 확인되었다. 4) Isotype이 決定된 2E93C9(YⅠ), 3E84E7(YⅠ), 4E3(YⅡ)의 세포를 생쥐의 腹腔에 주사하여 얻은 腹水를 indirect ELISA法에 의해 titer를 決定한 결과 모두 1:400,000 이상의 높은 titer를 나타내었다. 5) 處理區로서 單一클론抗體의 腹水와 對照區로서 normal mouse serum이 각각 2%씩 함유된 배양액속에서 난자를 배양한 후 顯徵鏡下에서 관찰했을 때 對照區에서 배양된 난자의 표면은 정상적인 형태를 나타냈으나 處理區에서 배양된 卵子는 표면에 뚜렷한 沈澱層을 형성하였다. 6) 處理區와 對照區 卵子를 Rabbit anti-mouse IgG-FITC가 1% 함유된 배양액속에서 배양하고 洗滌한 후 螢光顯徵鏡下에서 관찰한 바 處理區의 卵子는 透明帶 주위에서 螢光이 나타났으나, 對照區에서는 나타나지 않았다. This study was carried out ot produce and characterize monoclonal antibodies against porcine zona pellucida, and undertaken as a basic study to develop immunocontraceptive vaccine and to investigate the function of zana pellucida in early fertilization process. The results obtained were summarized as follows: 1. Spleen cells of three BALB/C mice(YⅠ, YⅡ and ZI) which were immunized with porcine zona pelucida were fused with myeloma cells(SP2/O-Ag14) by polyethylene glycol. At the result of fusion, fusion efficiency was 25.8 , 54.5% and 59.7% and positive efficiency 17.3%, 32.6% and 6.2%, respectively. 2. Cloning efficiency was shown to be from 20.8% to 48.4% and positive efficiency of them were 54.6% to 82%. 3. Sub-isotypes of three strong positive antibodies, 2E93C(YⅠ), 3E83E7(YⅠ) and 4E3(YⅡ) were determined by sandwich ELISA method and shown to be as IgG2b, IgH2a and IgM, respectively. 4. The titers of three ascitic fluids containing antibodies, 2E93C9(YⅠ), 3E84E7(YⅠ) and 4E3(YⅡ) were determined by indirect ELISA and all of them showed above 1:400,000. 5. The layer of precipitate was observed on the zona incubated with medium containing 2% ascitic fluid of monoclonal antibody while the eggs treated with 2% normal mouse serum did not. 6. Porcine eggs incubated with medium containing 2% ascitic fluid of monoclonal antibody and followed by subsequent incubation with Rabbit anti-mouse IgG-FITC conjugate showed strong fluorescent light on the zona surface while the zona of normal mouse serum-treated eggs did not show fluorescence.

RF-O₂ Plasma 처리한 MgO 박막의 스퍼터링 수율 측정

정원희(W. H .Jeoung),정강원(K. W. Jeong),임연찬(Y. C. Lim),오현주(H. J. Oh),박철우(C. W. Park),최은하(E. H. Choi),서윤호(Y. H. Seo),김윤기(Y. K. Kim),강승언(S. O. Kang) 한국진공학회(ASCT) 2006 Applied Science and Convergence Technology Vol.15 No.3

RF-O₂ plasma 처리한 MgO 박막의 스퍼터링 수율을 집속이온빔 장치를 이용하여 측정하였다. 가속 전압 10 ㎸의 Ga 이온빔을 주사했을 때 plasma 처리하지 않은 MgO 박막의 스퍼터링 수율은 0.33 atoms/ion, RF-O₂ plasma 처리한 MgO 박막의 스퍼터링 수율은 0.20 atoms/ion 으로 RF-O₂ plasma 처리한 경우 스퍼터링 수율이 낮아졌다. 또한 XPS, AFM을 통해 plasma 처리로 인한 MgO 표면의 변화를 관찰하였다. MgO 박막에 RF-O₂ plasma 처리 한 후 XPS O 1s spectra의 binding energy와 FWHM 값이 각각 2.36 eV와 0.6167 eV 작아졌고 표면거칠기의 RMS 값 또한 0.32 ㎚ 작아졌다. We measured sputtering yield of RF O₂-plasma treated MgO protective layer for AC-PDP(plasma display panel) using a Focused Ion Beam System(FIB). A 10 ㎸ acceleration voltage was applied. The sputtering yield of the untreated sample and the treated sample were 0.33 atoms/ion and 0.20 atoms/ion, respectively. The influence of the plasma-treatment of MgO thin film was characterized by XPS and AFM analysis. We observed that the binding energy of the O 1s spectra, the FWHM of O 1s spectra and the RMS(root-mean-square) of surface roughness decreased to 2.36 eV, 0.6167 eV and 0.32 ㎚, respectively.

Combustion properties of gaseous CH₄/O₂ coaxial jet flames in a single-element combustor

Kim, T.Y.,Choi, S.,Kim, H.K.,Jeung, I.S.,Koo, J.,Kwon, O.C. Butterworths [etc.] ; Elsevier Science Ltd 2016 Fuel Vol.184 No.-

Fundamental combustion properties of gaseous methane (CH<SUB>4</SUB>)/oxygen (O<SUB>2</SUB>) coaxial jet flames in a single-element combustor are experimentally evaluated as a preliminary step for subsequent studies of injection at very low temperature or using liquid O<SUB>2</SUB> for CH<SUB>4</SUB>/O<SUB>2</SUB> bipropellants, recently appearing to be the oncoming liquid bipropellant. A combustion chamber with quartz windows, a single shear coaxial injector and an exhaust nozzle on the downstream of the chamber is considered for the present study. Focusing on the measurements of the ignition and combustion stability limits of the coaxial jet flames in the chamber, flame visualization is also conducted by OH<SUP>*</SUP> chemiluminescence, schlieren imaging and direct imaging. Results show the ignition limits restricted than the combustion stability limits. Flame behaviors are largely classified into two, the stably attached flame and the oscillating, liftoff (near-blowout) flame. Due to cooling effects on the wall of the chamber, stably liftoff flame is not observed. The stability of the flame is greatest at fuel-rich condition (based on the injected amounts of CH<SUB>4</SUB> and O<SUB>2</SUB>). From the flame visualization flame thickness is found to be smaller than the injector lip thickness and insensitive to injection conditions. The laminar-flow behavior near the injector exit due to the strong burning of pure O<SUB>2</SUB> is observed even for high Reynolds numbers (Re). The flame visualization also exhibits the recirculating O<SUB>2</SUB> that enhances burning in the combustor through the reaction with the outer fuel jet. The results of ignition limits, combustion stability limits and flame visualization can be used as a database for researches of modeling the gaseous CH<SUB>4</SUB>/O<SUB>2</SUB> jet flames in the combustion chamber.

Magnetoelectric Coupling of CuFe2O4/Pt/Pb(Zr0.52Ti0.48)O3 Multilayer Thin Films

Hwang, S.-O.,Eum, Y.J.,Kim, J.-W.,Ryu, J.,Koo, C.Y.,Lee, J.-Y.,Lee, H.Y. Taylor Francis 2014 Ferroelectrics Vol.465 No.-

<P>CuFe2O4/Pt/Pb(Zr0.52Ti0.48)O-3 (PZT) multilayer thin films were grown on (111)-oriented Pt/TiO2/SiO2/Si < 100 > substrate. PZT layer was fabricated by the sol-gel method. Afterwards, Pt layer was deposited by ion beam sputtering method. Finally, CuFe2O4 layer were deposited using pulsed laser deposition method (PLD). The film structure is tri-layered type, where the bottom PZT layer covered the whole substrate, while Pt and CuFe2O4 layers were deposited through circular shadow masks to measure ferroelectric and magnetoelectric properties. Film microstructure was observed using XRD and FE-SEM. Magnetoelectric coefficients were calculated by measured magnetoelectric voltages using magnetoelectric measurement system.</P>

Influence of Annealing Temperature on Magnetoelectric Properties of CoFe2O4/Pt/Pb(Zr0.3Ti0.7)O3 Thin Films

Eum, Y.J.,Hwang, S.-O.,Ryu, J.,Kim, J.-W.,Koo, C.Y.,Lee, J.-Y.,Lee, H.Y. Taylor Francis 2014 Ferroelectrics Vol.465 No.-

<P>CoFe2O4/Pt/Pb(Zr0.3Ti0.7)O-3 thin films were grown on Pt/Ti/SiO2/Si substrate in order to investigate the magnetoelectric properties of ferromagnetic/ferroelectric multilayer thin films. Thin Pt layer was introduced to prevent inter-diffusion between CoFe2O4 and Pb(Zr0.3Ti0.7)O-3 (PZT) layers. PZT thin film was grown directly on top of Pt substrate by utilizing sol-gel spin coating technique. In order to investigate the possible annealing effect on film microstructure and magnetoelectric properties, multilayer thin film stack was heat-treated at different temperatures ranging from 550 degrees C to 650 degrees C. The structural properties of the films were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Ferroelectric and ferromagnetic behaviors were analyzed by measuring polarization and magnetization - electric and magnetic field hysteresis. Magnetoelectric coefficients were calculated by measuring magnetoelectric voltages using magnetoelectric measurement system. Both the magnetoelectric properties and the coupling effect of CoFe2O4/Pt/PZT films on ferromagnetic and magnetoelectric properties are discussed as a function of heat-treatment temperature.</P>

Self-standing and shape-memorable UV-curing epoxy polymers for three-dimensional (3D) continuous-filament printing

Sun, H.,Kim, Y.,Kim, Y. C.,Park, I. K.,Suhr, J.,Byun, D.,Choi, H. R.,Kuk, K.,Baek, O. H.,Jung, Y. K.,Choi, H. J.,Kim, K. J.,Nam, J. D. The Royal Society of Chemistry 2018 Journal of materials chemistry. C, Materials for o Vol.6 No.12

<P>In the development of three-dimensional printable materials for high-speed and high-resolution printing, UV-curing polymers can guarantee fast and precise printing of high performance load-bearing structures, but the injected drops of the monomers tend to spread over the substrates due to their low viscosity. In this study, we imposed the self-standing and shape-memorable capability of an epoxy acrylate (EA) monomer to ensure continuous filamentary 3D printing while maintaining its low viscosity nature. Using octadecanamide (ODA) with EA, strong hydrogen-bond networks (−N−H⋯OC−, −N−CO⋯H-O-, -N-H⋯N-) were additionally achieved in the material system and the developed material distinctively exhibited rheological duality at different processing stages: a low-viscosity liquid-like behavior (viscosity of ∼50 Pa) while passing through the nozzle and a self-standing solid-like behavior (static yield stress of ∼364 Pa) right after being printed. This reversible liquid-to-solid transitional capability was quantified by viscoelastic complex moduli provided a dynamic yield stress (<I>τ</I>y,G) of 210 Pa corresponding to the upright stacking up to ∼3.2 cm (3 wt% of ODA). The time (<I>t</I>y,G) required for conformational rearrangement was evaluated to be as fast as ∼10<SUP>−2</SUP> s. After UV curing, the 3D printed layers exhibited no air pockets or weld lines at the stacked interfaces, which could guarantee excellent mechanical performance and structural integrity.</P>

Amplification of Porcine SRY Gene for Sex Determination

Choi, S.G.,Bae, M.S.,Lee, E.S.,Kim, S.O.,Kim, B.K.,Yang, J.H.,Jeon, C.E.,Kim, H.H.,Hwang, Y.J.,Lee, E.S.,Kim, D.Y. Asian Australasian Association of Animal Productio 2009 Animal Bioscience Vol.22 No.8

The separation of X and Y chromosome-bearing sperm is of use in many aspects of livestock maintenance. In this study, we sought to determine the difference in DNA content between X- and Y-bearing sperm, separate sperm into X- and Y-enriched pools, and assess the efficacy of sorting. Sperm collected from Duroc and miniature pigs were stained with 20.8 $\mu{M}$ Hoechst 33342 and analyzed using a high-speed cell sorter. Measurement of the fluorescence intensity of stained sperm nuclei revealed that the X-bearing sperm of Duroc and miniature pigs respectively contain 2.75% and 2.88% more DNA than Y-bearing sperm. In total, 50.18% of the sperm were assigned to the X-sorted sample and 49.82% was assigned to the Y-sorted sample for Duroc pigs. For miniature pigs, the Xsorted sample represented 50.19% of the population and the Y-sorted represented 49.81% of the population. Duplex PCR was used to evaluate accuracy of sorting. A fast and reliable method for porcine sexing was developed through amplification of the sex-determining region of the Y chromosome gene (SRY). Oligonucleotide primers were designed to amplify the conserved porcine SRY high motility group (HMG) box sequence motif. We found that the primer pair designed in this study was 1.46 times more specific than previously reported primers. Thus, this study shows that the present method can be applied in porcine breeding programs to facilitate manipulation of the sex ratio of offspring and to achieve precise sexing of porcine offspring by amplification of the HMG box of the SRY gene.

Background study of NaI(Tl) crystals for the KIMS-NaI experiment

Adhikari, P,Adhikari, G,Choi, S,Ha, C,Hahn, I S,Jeon, EJ,Joo, H W,Kang, W G,Kim, H J,Kim, H O,Kim, K W,Kim, N Y,Kim, S K,Kim, Y D,Kim, Y H,Lee, H S,Lee, J H,Lee, M H,Leonard, D S,Li, J,Oh, S Y,Olsen, Institute of Physics Publishing Ltd 2016 Journal of Physics: Conference Series Vol.718 No.-