Arc-Magnetron 복합 코팅 공정에 의한 (TiAl)N 박막 합성에 관한 연구

한전건,윤주선,한준희 대한금속재료학회(대한금속학회) 2000 대한금속·재료학회지 Vol.38 No.3

(TiAl)N films deposited by cathodic arc process employing two separate targets of Al and Ti have lots of macro-particles on the surface. The macro-particles were found out to be generated mainly from Al cathode of low melting temperature. In the previous study, TiN films deposited with external magnetic field showed remarkable reduction of surface droplet. For the (TiAl)N coatings, however, the efficiency of Al droplet removal was not so much as TiN films. A new coating concept combining magnetron sputtering and arc evaporation for improved coating properties was made in this study. (TiAl)N and Al-gradient (TiAl)N coatings were deposited by arc-magnetron hybrid process and content of Al in the films was changed by power density of Al magnetron sputtering source. This hybrid process allowed compositionally gradient (TiAl)N coatings to be deposited with low macro-particles and excellent adhesion. It is noted that Al-gradient (TiAl)N coating showed micro hardness of 3,000 ㎏/㎟ and good adhesion of HF2 grade. The present study introduces the hybrid process parameters involved. The formation behavior of (TiAl)N and Al-gradient (TiAl)N coatings were investigated by SEM, EDX AES and XRD.

한국농업에서 농민층의 계층분화 : 제주농촌마을의 사례연구

고승한,레리버마이스터 부산대학교 사회조사연구소 1999 사회 조사 연구 Vol.14 No.-

Tropane Spirohydantoin들의 합성 및 구조분석

정대일,이도훈,송주현,이용균,최순규,박유미,한정태 동아대학교 환경문제연구소 2006 硏究報告 Vol.28 No.1

The tropane ring system is an important substructure in a number of natural products and synthetic compounds of biological and medicinal importance. As a result of the significance of the tropane ring system, the purpose of this study is the synthesis of anticonvulsant compounds of new s tructure anticipated anticonvulsant activity. After we first synthesized the various N-substituted nortropinone derivatives, we prepared new nortropane alkaloids and nortropinone derivatives. Substantially, we tried several experiments to optimize reaction condition. The tropane spirohydantoins 17, 18, 19, 20, 21 were respectively synthesized by the treatment of corresponding N-substituted nortropinone with potassium cyanide and ammonium carbonate.

Amazon’s Distribution Strategy: Doing the Right Things

Hahn,Yoonah,Youn,Myoung-Kil,Kim,Dongho 한국유통과학회 2019 KODISA ICBE (International Conference on Business Vol.2019 No.-

The purpose of this paper is to analyze and illustrate Amazon’s distribution strategy and its success. This paper examines Amazon’s distribution strategy to demonstrate the importance of distribution strategy to the success and sustainability of its organization. The analysis indicates that the distribution strategy, including technology, shipping, and distribution infrastructure, is the most vital factor for the success of Amazon. Recognizing the importance of distribution systems, constantly innovating convenient and on-time delivery methods, and taking control of inventory and shipping activities have separated Amazon from its competitors and led Amazon to establish many different types of fulfillment facilities all over the world. Given Amazon’s continued growth that came with its constant strive for delivery and cost efficiency and customer satisfaction, it was inevitable that Amazon would eventually venture into the actual shipping business and emerge as the competitor of the traditionally well-known shipping companies such as DHL, FedEx, and UPS. The previous and current Amazon’s distribution strategies demonstrate that Amazon will continue to focus on developing and implementing new and creative distribution strategies to separate itself from the rest of the retail and e-businesses.

Hydrophobic Properties of Phytochrome : Interactions of 8-anilinonaphthalene-1-sulfonate to the 59 kD and 124 kD Oat Phytochromes 59kD 및 124kD 귀리 phytochrome과 8-anilinonaphthalene-1-sulfonate의 상호작용

Hahn, Tae-Ryong 경희대학교 유전공학연구소 1989 遺傳工學論文集 Vol.1 No.-

귀리 59kD 및 124kD phytochrome의 소수성질을 8-anilinonaphthalene-1-sulfonate(ANS)를 써서 구명하였다. 59kD 및 124kD phytochrome의 흡광도와 광변환속도를 측정 분석한 결과 ANS는 Pr형보다 Pfr형에 대해 조금더 친화성이 있었다. 124kD phytochrome의 광변환에 따른 ANS의 형광을 측정한 결과 거의 변화가 없었다. 이러한 결과는 118kD phytochrome의 Pfr형에 노출된 소수 domain(Hahn and Song, 1981)이 59kD 및 124kD phytochrome에서는 숨겨져 있음을 의미한다. 이 소수 donain은 chromophore와 매우 근접하여 있을 것으로 생각되므로(Hershey et al., 1985; Hahn and Chae, 1986), 6kD 및 55kD proteolttic domain은 각각 Pfr형 phytochrome의 소수표면 노출에 부정적 및 긍정적으로 각각 작용할 것으로 믿어진다. 8-anilinonaphthalene-1-sulfonate (ANS) has been employed to probe the hydrophobic properties of 59 kD and 124 kD oat phytochromes. ANS interacts slightly more with the Pfr than the Pr for both of the 59 kD and 124 kD phytochromes in terms of spectral perturbation and phototransformation kinetics. Almost no changes in the ANS fluorescence emission upon phototransformation of 124 kD phytochrome have been observed. These results suggest that the hydrophobic domain which is exposed in the Pfr form of 118 kD phytochrome (Hahn and Song, 1981) is shielded for the 59 kD and 124 kD phytochromes. Since the hydrophobic domain is assumed to locate at/near the chromophore (Hershey et al., 1985; Hahn and Chae, 1986), the 6 kD and 55 kD proteolytic domains seem to negative and positive roles for the exposure of the hydrophobic site in the Pfr of phytochrome, respectively.

Focal form of acquired myasthenia gravis with megaesophagus in a Yorkshire terrier dog

Hahn, Tae-Yeon,Kang, Min-Hee,Eom, Ki-Dong,Park, Hee-Myung The Korean Society of Veterinary Science 2014 大韓獸醫學會誌 Vol.54 No.1

A 12-year-old, castrated male Yorkshire terrier dog presented with frequent regurgitations that had begun 45 days earlier and become more progressive. Radiographs revealed an air-trap region behind the cranial esophageal sphincter muscle in the esophagus and esophagographies with barium contrast showed mild esophageal dilation with decreased motility. Esophageal motility increased within 5 min of neostigmine methylsulfate administration and acetylcholine receptor antibodies titer increased to beyond the normal range. Based on these findings, acquired myasthenia gravis with focal form was diagnosed, making this the first such case diagnosed by an acetylcholine receptor antibody test in Korea.

Physical Origin of the Contact Frequency in Chromosome Conformation Capture Data

Hahn, S.,Kim, D. Biophysical Society ; Published for the Biophysica 2013 Biophysical journal Vol.105 No.8

Physical proximity between each pair of genomic loci in a nucleus is measured as a form of contact frequency in chromosome conformation capture-based methods. Complexity of chromosome structure in interphase can be characterized by measuring a statistical property of physical distance between genomic loci according to genomic separation along single chromatids. To find a relationship between the physical distance and the contact frequency, we propose a polymer model derived from the Langevin equation. The model is derived by considering a structure of a chromosome as a trajectory of a particle, where each consecutive segment in the chromosome corresponds to a transient position in the trajectory over time. Using chromosome conformation capture data, we demonstrate the functional relationship between the two quantities. The physical distances derived from the mean contact frequencies by the model show a good correlation with those from experimental data. From the model, we present that the mean contact frequency curve can be divided into three components that arise from different physical origins and show that the contact frequency is proportional to the contact surface area, not to the volume of segments suggested by the fractal globule model. The model explains both a decaying pattern of the contact frequency and the biphasic relationship between the physical distance and the genomic length.

The Relationship Between the Water Color and the Transparency in the Seas Around Korea

Hahn, Sangbok The Korean Society of Oceanography 1968 韓國海洋學會誌 Vol.3 No.2

The distributions of average water color and the transparency in the seas around Korea show two patterns: the one is the East Sea and the South Ses, the other is the Yellow Sea. In the East Sea and the South Sea, the water colors C$\sub$E/ in Forel scales change from green to greenish blue with distance x in miles from the seashore, an average color is bluish green, 3.7 in Forel scales, and the relationship is given by C$\sub$E/ = 5e$\^$-0.056.root.x; an average transparency is 15m and the transparency T$\sub$E/ shows following formula with distance x, E$\sub$E/=0.9.root.x+10. In the Yellow Sea, the water color C$\sub$Y/ changes from green yellow to bluish green with distance, an average color is light green, 5.6 in Forel scales, and the relationship is given by C$\sub$Y/= 8.5e$\^$-0.086.root.x; an average transparency is 7m, the farther it is from the seashore, the deeper transparency T$\sub$Y/ is as following, T$\sub$Y/=1.2 .root.x+1. Along the seashore, the transparency T$\sub$Y/ is only 10% that of the East Sea and the South Sea. The distributions of the water color and the transparency by depth change in values within the continental shelf. The water color in Forel scales decreases with the distance from the seashore and depth; the transparency increases with the distance and depth. They are caused by suspended particles, especially suspended clay, and it is the major factor in the change in color and transparency, particularly in the Yellow Sea. In September, the sea water is the clearest in the seas around Korea, transparency shows the maximum and water color the minimum in forel scales. The water color shows green yellow when transparency is 1m, green at 10m, and greenish blue at 20m. the relationship between the water color and the transparency shows an exponential distribution as following, C=9e$\^$-kT/, k=0.0625m$\^$-1/. This formula agrees with calculated formulas between the water color and the transparency from the emprircal formulas C$\sub$E/ and T$\sub$E/, C$\sub$Y/ and T$\sub$Y.

From Partition Identities to a Combinatorial Approach to Explicit Satake Inversion

Hahn, Heekyoung,Huh, JiSun,Lim, EunSung,Sohn, Jaebum Springer-Verlag 2018 Annals of Combinatorics Vol.22 No.3

A COLLISION MODEL FOR FINE PARTICLES IN A TURBULENT SYSTEM

Hahn, Yoon Bong 한국화학공학회 1994 Korean Journal of Chemical Engineering Vol.11 No.4

A model is proposed to describe the collision rate of small particles suspended in a turbulent system. The model combines the possible collision mechanisms: 1) collisions due to the relative velocity between fluid and particles, and 2) collisions due to the turbulent diffusion of particles. This model also accounts for the effect of particle concentration on the collision rate. It was found that the turbulent diffusion of particles plays an important role in the collision of equally sized particles as well as of unequally sized particles. The model predictions also show that the collision rate of particles is strongly affected by the concentration of solid particles and by the turbulence intensity. Much more reliable predictions than previously possible have been obtained with the present model.