Spin Properties of PVA Nanofibers with Ferritin

이영백,현영훈,S. Y. Park,M. K. Shin,S. J. Kim 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.3

We investigate the morphological and the magnetic properties of ferritin-embedded poly(vinylalcohol) (PVA) nanofibers. Monodispersed ferritin (MF) and the clustered superparamagnetic (SPM) ferritin (CF) were embedded into biocompatible PVA nanofibers by using an electrospinning method. The magnetic phase of CF was partly changed from an antiferromagnetic to a ferromagnetic ordering, depending on the annealing temperature. CF keeping the SPM phase was successfully synthesized into PVA nanofibers and the SPM properties were analyzed and compared with those of natural ferritin embedded in PVA nanofibers. These results can be applied in manipulating the size and the magnetic ordering of biocompatible superparamagnets to realize biomedical electromagnetic devices.

직무역량 향상을 위한 전문대 조리과 교육과정개선 기초연구

이영백 한국외식경영학회 2003 외식경영연구 Vol.6 No.2

The department of culinary arts is established in junior college according to development food service industries. The curriculum in this department should be developed to improve job competence. This study aims to assess the need for improving job competency of students majoring in culinary arts. 26 common and 68 culinary job competences are extracted by literature review and interview. These job competences are extracted by literature review and interview. These job competences are used for survey items. A need assessment had been performed to identify the order of job competence. These result are helpful to develop the curriculum in the field of culinary arts. The result revealed that job-related abilities, knowledges, and attitudes for comprter, foreign language, and law are needed to be educated for enhancing common job competence. For culinary job competence, computer ability, carving and decoration, knowledge for food service industries are needed to be learned for future performance.

Spin-Photonic, Photonic and other Relevant Properties of Ni2MnGe and Other Heusler Alloys

이영백,김기원,R. J. Kim,Y. J. Yoo,Y. V. Kudryavtsev 한국물리학회 2006 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.49 No.5I

Various physical properties for .lms of Heusler alloys, such as Ni2MnGe and Cu2MnAl, with dierent atomic orders were studied. The .lms were deposited on glass substrates at several sub- strate temperatures from 150 to 730 K. The structural characterization was performed by using X-ray diraction. A superconducting-quantum-interference-device magnetometer was employed to measure the temperature dependence of the spin properties. The photonic and the spin-photonic properties were also investigated. Alloy .lms with corresponding L21-type structural orders were successfully fabricated. The ordered .lms exhibited physical properties close to those of the cor- responding bulk alloy. The signi.cant eects of structural disorder on the photonic, the spin, and the spin-photonic properties were experimentally observed. Unexpectedly, the disordered Ni2MnGe alloy .lms were not ferromagnetically ordered. Atomic disordering led to the disappearance of the high-energy absorption peak in the optical-conductivity spectrum and to the lack of a spin-photonic response. All these results were further analyzed in connection with the electronic structures of the alloy.

Finite Difference Method for the Landau-Lifshitz Equation

이영백,남원창,조민형 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.3

A numerical approach, based on a nite difference method and a successive over relaxation (SOR) method, is presented for the Landau-Lifshitz or the Landau-Lifshitz-Gilbert equation for the study on the dynamics of magnetization. One- and two-dimensional formula for the discretized Landau- Lifshitz equation with an exact solution are described and numerically solved using the Gauss-Seidel and the SOR methods. The numerical errors are compared for both methods and the optimum relaxation factor, !, for the SOR method is numerically found.

Flux-Pinning Effects in MgB2 Doped with Nano-Scale TiO2 and SiC Inclusions

이영백,J. S. Park,G. H. Kim,V. L. Svetchnikov,V. G. Prokhorov,J.-H. Kang,V. A. Khokhlov,P. Mikheenko 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.3

Bulk MgB2 doped with TiO2 and SiC was prepared by using an in-situ solid state reaction. A high-resolution TEM study revealed that TiO2 doping led to finer grains than doping with SiC one, while small-sized MgO inclusions were presented in both cases. At the same time, the TiO2-doped MgB2 manifested an improved upper critical eld and critical current density over the entire temperature and magnetic eld ranges. We conclude that the observed improvements on superconducting properties are attributable to an enhanced flux pinning by the grain boundaries.

Electromagnetic Behavior of Representative Metamaterial Structures

이영백,V. D. Lam,J. B. Kim,이성재 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.2

We investigated systematicaly the electromagnetic behavior of different magnetic metamaterials, from the split-ring resonator to the cut-wire pair, for providing a negative magnetic permeability. The combination of a cut-wire pair and a continuous wire was also studied experimentaly. We found that the combined structure exhibited both left- and right-handed transmision bands. Until the width of the cut-wire pair was increased to merge with the adjacent continuous wire to form the so-caled fishnet structure, the left-handed (LH) behavior continued to be observed. Finaly, the effect of the structural parameters on the LH behavior of the fishnet structure was also investigated. These structures were designed, built and measured in the microwave frequency range.

寺下 聚落에 關한 硏究 : 通度寺 周邊을 中心으로

李永白 동국대학교 지역환경연구소 1983 地域環境 Vol.- No.2

The purpose of this study is to clarify the structural and regional Characteristics of the “SAHACHON” a village developed and originated for the purpose of maintaining the temple economy. To achieve the purpose, both indoors studies and field works are utilized to the utmost, studying various books and pamphlets published by the public and private institutions and visiting the villages more than seven times. The results of the study are summarized as follows; 1. The location and form of SAHACHON have to do with by the living ways of the inhabitants and the conditions of the roads and the land form. The villages inside the gate of the temple form agricultural cluster villages and the villages outside the gate of temple are formed along the roads, which is mainly due to the function of the villages as tourist settlement. 2. The type of the houses and accompanying facilities SAHACHON varies according to the social and economic position of their owners. 3. The development and function of SAHACHON varies according to time and the policies of the government. In Koryeo Dynasty, SAHACHON were large establishments under the control of temple, in which temple servants, peasants and other craftman lived. 4. The proportion of temple owned land in the village has decreased with time but the decrease of temple owned land has deen slower in the areas nearest the temple. 5. The population of the agricultural village inside the gate of the temple has decreased remarkably but the population of the villages outside the gate has increased, which seems mainly due to the function of the villages as tourist settlement. 6. The consciousness of the populace of SAHACHON are complex, but Buddhism is found to be the main basis of their consciousness.

Correlation Between the Diffracted Magneto-Optical Kerr Effect and the Structure in Gyrotropic Gratings

이영백,Y. H. Lu,M. H. Cho,J. B. Kim,G. J. Lee,이주열 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.4

One-dimensional gyrotropic gratings can be fabricated by using all kinds of nano-fabrication techniques. Such laterally patterned magnetic nanostructures become more attractive because of their potential applications to magnetic and magneto-optical (MO) information storage media, light waveguides, filters, new metamaterials, etc. A significant difference in the MO response between specular and non-specular spots was noticed, which is mainly attributed to the structure of gyrotropic gratings. In order to elucidate the correlation between the diffracted MO Kerr effect (DMOKE) and the structure, we utilize the rigorous coupled-wave analysis, which is implemented with Airy-like internal reflection series. This analysis is a powerful tool to detect the grating structure so that the D-MOKE signal can be effectively controlled.

Induced Magnetization and Charge Ordering in La0:7Ca0:3MnO3/La0:9Ca0:1MnO3 Multilayered Films

이영백,Y. H. Hyun,G. H. Kim,J. S. Park,V. G. Prokhorov,V. L. Svetchnikov 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.5

The structural, the magnetic and the transport properties of La0:7Ca0:3MnO3/La0:9Ca0:1MnO3 multilayered lms, prepared by rf-magnetron sputtering, have been investigated. The high-resolution electron-microscopy studies reveal the formation of dierent crystal structures in the two constituent sublayers, but without sharp and well-dened interfaces between sublayers. At the same time, small regions of a double-period modulated phase exist in the La0:9Ca0:1MnO3 sublayers at room temperature, manifesting the formation of a charge-ordered state. The magnetic measure-ments reveal a signicant enhancement of the ferromagnetic ordering in the La0:9Ca0:1MnO3 due to strong magnetic coupling between the constituent sublayers. The films show an alternating shape of the temperature-dependent anisotropic magnetoresistance near the metal-insulator transition.

Simulation of the Reflectivity of One-Dimensional Photonic Crystals Made of Ti2O3 and Al2O3 Films

이영백,K. W. Kim,M. D. Huang,S. Y. Park 한국물리학회 2005 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.47 No.6

The reflectance spectra of one-dimensional photonic crystals (PCs), consisting of alternating Ti2O3 and Al2O3 films with different repetition numbers, have been systematically simulated using the transfer-matrix method. The simulation was performed at oblique incidence and at normal incidence. The results are presented as a function of the repetition number, and a graphic method is employed to explain and understand the results in a visual way. At the designed wavelength,no omni-directional photonic bandgap (PBG) can be realized, due to a fact that the effect of the Brewster angle always exists in this system, regardless of the repetition number. However, a narrow omni-PBG can be found away from the designed wavelength.