W-REGULAR CONVERGENCE OF $R^i$-CONTINUA

Rhee, C. J.,Kim, I. S.,Kim, R. S. Korean Mathematical Society 1994 대한수학회보 Vol.31 No.1

In the course of study of dendroids, Czuba [3] introduced a notion of $R^{i}$ -continua which is a generalization of R-arc [1]. He showed a new class of non-contractible dendroids, namely of dendroids which contain an $R^{i}$ -continuum. Subsecequently Charatonik [2] attempted to extend the notion into hyperspace C(X) of metric continuum X. In so doing, there were some oversights in extending some of the results relating $R^{i}$ -continua of dendroids for metric continua. In fact, Proposition 1 in [2] is false (see example C below) and his proof of Theorem 6 in [2] is not correct (Take Example 4 in [4] with K = [e,e'] as an $R^{1}$-continuum of X and work it out. Then one seens that K not .mem. K as he claimed otherwise.). The aims of this paper are to introduce a notion of w-regular convergence which is weaker than 0-regular convergence and to prove that the w-regular convergence of a sequence {Xn}$^{\infty}$$_{n=1}$ to $X_{0}$ of subcontinua of a metric continuum X is a necessary and sufficient for the sequence {C( $X_{n}$)}$^{\infty}$$_{n=1}$ to converge to C( $X_{0}$ ), and also to prove that if a metric continuum X contains an $R^{i}$ -continuum with w-regular convergence, then the hyperspace C(X) of X contains $R^{i}$ -continuum.inuum.uum.

Aminoacyl-transferases and the N-end rule pathway of prokaryotic/eukaryotic specificity in a human pathogen

Graciet, E.,Hu, R.-G.,Piatkov, K.,Rhee, J. H.,Schwarz, E. M.,Varshavsky, A. Proceedings of the National Academy of Sciences 2006 PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF Vol.103 No.9

<P>The N-end rule relates the in vivo half-life of a protein to the identity of its N-terminal residue. Primary destabilizing N-terminal residues (Nd(p)) are recognized directly by the targeting machinery. The recognition of secondary destabilizing N-terminal residues (Nd(s)) is preceded by conjugation of an Nd(p) residue to Nd(s) of a polypeptide substrate. In eukaryotes, ATE1-encoded arginyl-transferases (R(D,E,C*)-transferases) conjugate Arg (R), an Nd(p) residue, to Nd(s) residues Asp (D), Glu (E), or oxidized Cys residue (C*). Ubiquitin ligases recognize the N-terminal Arg of a substrate and target the (ubiquitylated) substrate to the proteasome. In prokaryotes such as Escherichia coli, Nd(p) residues Leu (L) or Phe (F) are conjugated, by the aat-encoded Leu/Phe-transferase (L/F(K,R)-transferase), to N-terminal Arg or Lys, which are Nd(s) in prokaryotes but Nd(p) in eukaryotes. In prokaryotes, substrates bearing the Nd(p) residues Leu, Phe, Trp, or Tyr are degraded by the proteasome-like ClpAP protease. Despite enzymological similarities between eukaryotic R(D,E,C*)-transferases and prokaryotic L/F(K,R)-transferases, there is no significant sequelogy (sequence similarity) between them. We identified an aminoacyl-transferase, termed Bpt, in the human pathogen Vibrio vulnificus. Although it is a sequelog of eukaryotic R(D,E,C*)-transferases, this prokaryotic transferase exhibits a 'hybrid' specificity, conjugating Nd(p) Leu to Nd(s) Asp or Glu. Another aminoacyl-transferase, termed ATEL1, of the eukaryotic pathogen Plasmodium falciparum, is a sequelog of prokaryotic L/F(K,R)-transferases (Aat), but has the specificity of eukaryotic R(D,E,C*)-transferases (ATE1). Phylogenetic analysis suggests that the substrate specificity of R-transferases arose by two distinct routes during the evolution of eukaryotes.</P>

Magnetic Characterization of the Nd Based Permanent Magnet by Newly - Developed Bipolar Pulse - Type Hysteresis Loop Tracer

J. R. Rhee 한국자기학회 1999 Journal of Magnetics Vol.4 No.3

By applying an alternate pulsed magnetic field - generated by using a sequential ignition circuit and a magnet exciting circuit - with peak value of about 10 T to the rod type Nd based magnet Nd₂Fe_(l2.7)Cr_(1.3)B with length of 5㎜ and diameter of 3.6㎜, the basic magnetic properties such as saturation magnetization, residual magnetization, coercivity, maximum energy products, magnetic anisotropy and anisotropic field are investigated with obtaining the major and minor J-H loops of the magnet. The increase in coercivity due to eddy currents in ac measurement of coercivity is calculated considering eddy current loss by analyzing a wave of generating magnetic field. The average coercivity calculated for the magnet is about 12.2 kOe, anisotropy magnetic field and anisotropic constant are measured as 60 kOe and 2.43 Mj/㎥, respectively.

W-REGULAR CONVERGENCE OF R^i-CONTINUA

RHEE, C.J.,KIM, I.S.,KIM, R.S. 全北大學校 基礎科學硏究所 1994 基礎科學 Vol.17 No.-

Permalloy/Al₂O₃/Co 접합의 자기터널 효과

이장로,이민숙,송현주,장현숙,김미양,이용호 숙명여자대학교 자연과학연구소 1993 자연과학논문집 Vol.- No.4

1 X 10 -6 Torr의 진공에서 열저항 가열식 진공증착 방법으로 제작한 permalloy/Al₂O₃/Co 강자성 터널접합의 자기저항 효과를 조사하였다. 이 논문에서는 제작한 강자성 터널접합 시료의 전류-전압 특성과 자기 value 효과를 측정하고, 시료진동형자기계로 측정한 자기이력곡선을 통하여 터널저항의 히스테리시스성 자장 의존성을 조사하였다. 터널링은 전류 전압 특성을 측정함으로써 확인 되어진다. 자기저항의 히스테리시스 곡선은 자화의 히스테리시스 곡선과 잘 대응한다. 측정한 자기저항비 △R/R은 실온에서 약 0.6%였다. Magnetoresistance was studied for the ferromagnetic tunneling junction in permalloy/Al₂O₃Magnetoresistance was studied for the ferromagnetic tunneling junction in permalloy/Al₂O₃/Co prepared by evaporation in a vacuum of 1 X 10-6 Torr. We measured voltage-current characteristic and magnetic value effect of prepared ferromagnetic tunneling junction sample. We investigated field-dependency of tunnel resistance by Wheat-stone bridge method and measured magnetic hysteresis curve by vibrating sample magnetometer. The tunneling is confirmed by measuring voltage-current characteristic. The hysteresis curve of magnetoresistance corresponds well with that of magnetization. The magnetoresistance ratio △R/R is 0.6% at room temperature.

Permalloy/Al₂O₃/Co 접합의 자기터널 효과

이민숙,송현주,장현숙,김미양,이장로,이용호 全北大學校 基礎科學硏究所 1994 基礎科學 Vol.16 No.-

1×10 exp (-6) Torr의 진공에서 열저항 가열식 진공증착 방법으로 제작한 permalloy/Al_2O_3/Co 강자성 터널접합의 자기저항 효과를 조사하였다. 이 논문에서는 제작한 강자성 터널접합 시료의 전류-전압 특성과 자기 valve 효과를 측정하고, 시료진동형자기계로 측정한 자기이력곡선을 통하여 터널저항의 히스테리시스성 자장 의존성을 조사하였다. 터널링은 전류-전압 특성을 측정함으로써 확인 되어진다. 자기저항의 히스테리시스 곡선은 자화의 히스테리시스 곡선과 잘 대응한다. 측정한 자기저항비 ΔR/R은 실온에서 약 0.6 %였다. Magnetoresistance was studied for the ferromagnetic tunneling junction in permalloy /Al_2O_3/Co prepared by evaporation in a vacuum of 1×10 exp (-6) Torr. We measured voltage current characteristic and magnetic valve effect of perpared ferromagnetic tunneling junction sample. We investigated field dependency of tunnel resistance by Wheat stone bridge method and measured magnetic hysteresis curve by vibrating sample magnetometer. The tunneling is confirmed by measuring voltage-current characteristic. The hysteresis curve of magnetoresistance corresponds well with that of magnetization. The magnetoresistance ratio ΔR/R is 0.6% at room temperature.

롤러형 파종기 구동용 직류모터의 회전속도 제어

이중용,김유용,박상래 한국농업기계학회 2000 바이오시스템공학 Vol.25 No.5

Tb/Fe 다층박막의 자기 및 자기광 특성

이장로,장현숙,김미양,이용호,손봉균 全北大學校 基礎科學硏究所 1994 基礎科學 Vol.16 No.-

기판회전 테이블이 부착된 DC, RF-magnetron sputtering 장치로 유리기판 위에 제작한 1000 Å정도의 8.8 ÅTb/XÅ Fe (X= 5.4∼11.0) 다층박막에 관하여 시료진동현 자기계와 타원편광 분석장치를 사용하여 자화, 수직자기이 방성, Kerr 회전각의 Fe층 두께와 열처리온도 의존성이 연구되었다. Fe층 두께가 7.8Å 기점으로하여 자화용이축의 전이가 나타나기 시작하여 6.4Å 일때 수직자기이방성을 나타낸다. 실험치로부터 계산한 Fe와 Tb층의 경계면 수직이 방성 에너지 K_s = -0.38 erg/㎠이고, Fe층만의 체적수직이방성 에너지 K_s = -8.50 × 10 exp (5) erg/㎤이다. Polar kerr 회전각은 Fe층 두께 7.8Å에서 극대값 2θ_k=1.22˚를 갖는다. Studies have been done experimentally to investigate the effects of the Fe sublayer thickness on magnetization, anisotropy, and Kerr rotation in 8.8ÅTb/X Å Fe (X = 5.4∼11) compositionally modulated films prepared in a multiple-gun sputtering chamber with rotating table. The ranges of Fe sublayer thickness required for perpendicular anisotropy were detemined. The interface and volume anisotropy energies for Tb/Fe films were estimated. The annealing temperture dependence of magnetic and magneto-optic properties has been discussed.

진공증착박막 MnAl의 자기적 성질에 관한 연구

李章魯,우안진,장현숙 숙명여자대학교 자연과학연구소 1989 자연과학논문집 Vol.- No.1

Magnetic and other properties of MnAl films prepared by vacuum evaporation were examined. Mixed powders of Mn and Al were used as an evaporation source. To find the optimum conditions of fabrication of MnAl evaporated film, the dependence on substrate temperature and the concentration of evaporation source was investigated. The optimum conditions of fabrication of films were found to be as follows, substrate temperature : 400℃, concentration of Mn: 72∼74 wt %. Magnetic properties of the films evaporated under these condition were 550∼554 Oe in coercivity, 0.62 in squareness, 2.14∼2.90×10³ emu/cm³ in saturation induction and 410℃ in the Curie temperature. The easy axis of magnetization was normal to the coated film surface. In order to increase the saturation induction, element cu was added. Addition of Cu has an effect on increasing of the saturation induction at the sacrifice of deterioration of the coercivity.

Fe/Cu/Co(사이층 교환 상호작용 비결합) 박막의 자기저항 효과

이장로,송은주 숙명여자대학교 자연과학연구소 1993 자연과학논문집 Vol.- No.4

Fe/Cu/Co/Cu sandwiches were prepared by successively depositing Cu(30Å), Co(50Å), Cu(60Å) and Fe(50Å) layers on glass and silicon substrates in a vacuum of 1 X 10 Torr. The sandwiches consisting of magnetic layers with different coercive fields and intervening non-magnetic layer. When a moderate magnetic field is applied. magnetizations of two ferrimagnetics became oriented antiparalled to each other. and the electric resistance increased significantly by spin-dependent electron scattering. We masured field-dependency of magnetoresistance by Wheat-stone bridge method. and tried to correspond the hysterisis curve of magnetoresistance with magnetic hysterisis curve by vibration sample magnetometer. The magnetoresistance ratio of Fe/Cu/Co/Cu sandwiches on glass and silicon was found to be 2.3% at room temperature.