$^{13}C$ Nuclear Magnetic Resonance Study of Graphite Intercalated Superconductor $CaC_6$ Crystals in the Normal State

김성훈,강기혁,민병진,이무희,김준성,Kim, Sung-Hoon,Kang, Ki-Hyeok,Mean, B.J.,Ndiaye, B.,Lee, Moo-Hee,Kim, Jun-Sung The Korean Superconductivity Society 2010 Progress in superconductivity Vol.12 No.1

$^{13}C$ NMR (nuclear magnetic resonance) measurements have been performed to investigate the local electronic structure of a superconducting graphite intercalation compound $CaC_6$ ($T_c$ = 11.4 K). A large number of single crystals were stacked and sealed in a quartz tube for naturally abundant $^{13}C$ NMR. The spectrum, Knight shift, linewidth, and spin-lattice relaxation time $T_1$ were measured in the normal state as a function of temperature down to 80 K at 8.0 T perpendicular to the c-axis. The $^{13}C$ NMR spectrum shows a single narrow peak with a very small Knight shift. The Knight shift and the linewidth of the $^{13}C$ NMR are temperature-independent around, respectively, +0.012% and 1.2 kHz. The spin-lattice relaxation rate, $1/T_1$, is proportional to temperature confirming a Korringa behavior as for non-magnetic metals. The Korringa product is measured to be $T_1T\;=\;210\;s{\cdot}K$. From this value, the Korringa ratio is deduced to be $\xi$ = 0.73, close to unity, which suggests that the independent-electron description works well for $CaC_6$, without complications arising from correlation and many-body effects.

Q-행렬에 근거하는 치유교습 순서

김성훈(Sung Hoon Kim) 한국교육평가학회 2020 교육평가연구 Vol.33 No.2

This study was to investigate how and how much does a Q-matrix contribute in deciding the sequence of remedial instruction of the unattained attributes being identified from cognitive diagnostic assessment. Applying the adjacency matrix, reachability matrix, and influence diagram introduced in cognitive assessment context by Tatsuoka (2009), the sequence was defined as the causal relationship among attributes forming a Q-matrix. Three Q-matrices were gone under analysis. They were an example one, one from Sung’s(2018) study, and the other from Park & Lee’s(2018) study. The results were discussed into three conclusions. Firstly, the Q- matrix could provide a objective starting point for a whole sequence of remedial instruction; secondly, the more hierarchical a Q- matrix was the more it helped deciding sequence of remedial instruction; thirdly, knowledge states from cognitive diagnosis might contradict the causal relationship assumptions implied by the Q-matrix.

홍바리, Epinephelus fasciatus의 인공수정 전.후 난문의 미세구조적 변화

김성훈,이치훈,주해성,김형배,이영돈,Kim, Seong-Hoon,Lee, Chi-Hoon,Ju, Hea-Sung,Kim, Hyung-Bae,Lee, Young-Don 한국현미경학회 2011 Applied microscopy Vol.41 No.2

The micropyles on the prefertilized and artificial fertilized eggs of Epinephelus fasciatus were investigated using scanning electron microscope (SEM). The micropyles ($6.6{\pm}0.41\;{\mu}m$) of E. fasciatus eggs were found in the animal pole and theirs shape were observed as a flat crateriform of cylindrical shape. The micropylar vestibule arranged by 6~7 thickened spiral annuli on the ridge and contributed to differentiate and form fertilization cone for blocking to polyspermy by presenting swollen vestibule structure. As E. fasciatus eggs was pelagic, so chorionic surface was an uneven structures such as circular and fillar form nodules. Especially, various pores (0.15~0.55 ${\mu}m$, 230~270 pores) distributed at the only around micropyles, those pores radiately exhibited regular projection structures showing gill filament-shape. These ultrastructural characters of E. fasciatus eggs can be utilized in a taxonomical cue of grouper species.

역기하렌즈 착용 전 요인들이 착용 후 시력에 미치는 영향

김성훈,이정훈,김춘식,Sung Hoon Kim,Jung Hoon Lee,Chun Sik Kim 대한안과학회 2010 대한안과학회지 Vol.51 No.10

Purpose: To determine whether patient factors (pre-fitting patient’s data) before reverse-geometry lens (RGL) use could be predicting factors for the increase in visual acuity after RGL use. Methods: The authors reviewed out patient records of 805 eyes of 423 patients wearing RGLs from March 2003 to May 2009. The relationship between patient factors on UVA before wearing a RGL examined at follow-ups and the IVA after wearing a RGL were analyzed. Results: The spherical refractive errors and the cylindrical refractive errors showed statistically significant results (p < 0.05). The lower was the refractive error, the greater were the UVA and IVA results. Correlations existed between the corneal astigmatism and UVA or IVA at three months (p < 0.05). The lower was the corneal astigmatism, the greater were the UVA and IVA results. Correlations were observed between the initial visual acuity and IVA, although the initial visual acuity cannot be a predictor. The other factors evaluated did not show statistically significant results (p > 0.05). Conclusions: The refractive error and the corneal astigmatism may be strong predictors of UVA and IVA after RGL use. J Korean Ophthalmol Soc 2010;51(10):1305-1311

홍바리, Epinephelus fasciatus 정자의 미세구조

김성훈,이치훈,송영보,주해성,김형배,이영돈,Kim, Seong-Hoon,Lee, Chi-Hoon,Song, Young-Bo,Ju, Hea-Sung,Kim, Hyung-Bae,Lee, Young-Don 한국현미경학회 2012 Applied microscopy Vol.42 No.2

Ultrastructural characteristics of blacktip grouper, Epinephelus fasciatus spermatozoa were investigated using transmission and scanning electron microscopy. The spermatozoa of E. fasciatus consisted of a spherical head part, a midpiece with cytoplasmic canal entrance and a flagellum with lateral fins. Internal ultrastructurally, the nucleus contains high electron dense chromatin having granular particles and has no acrosome. The centriolar complex lies outside of the nuclear fossa and it is connected by the osmophilic filaments. Also the osmophilic filaments connect between the centriolar complex and the nuclear membrane. The midpiece contains eight to nine spherical mitochondria, cytoplasmic canal and necklaces. The flagellum has a typical 9+2 axonemal structure. The lateral fins contain vesicles and a typical 9+2 axonemal structure. Consequently this study contributes to comparative grouper spermatology and provide useful systematic taxonomic characters.

Ethylenethiourea의 임신 랫트에 있어서 기관형성기 투여시험 2. 수 미로 시험과 양수내의 α-fetoprotein, 요소 및 유리지방산 함량에 미치는 영향

김성훈,허린수,Kim, Sung-hoon,Huh, Rhin-soo 대한수의학회 1991 대한수의학회지 Vol.31 No.4

This study was carried out to investigate; the alpha-fetoprotein, urea and free fatty acid in amniotic fluids and water filled multiple T-maze test of fetuses affected by Ethylenethiourea. The S.P.F. Sprague-Dawley female rats(10 weeks) were used in this study and these animals were divided into four groups; control group I (10mg/kg/day), group II(30mg/kg/day), group III(50mg/kg/day). The results obtained were summarized as follows; 1. In the water filled multiple T-maze test of F1 male rats, The time and errors from start point to goal point of 30mg/kg group are significantly(p<0.001) increased from control group in 3rd day of test. In F1 female rats of 2nd day and 3rd day of water filled multiple T-maze test, The time and some errors in 30mg/kg group are significantly (p<0.05) increased from control group. 2. Alpha-fetoprotein values of all treated groups(10mg/kg, 30mg/kg and 50mg/kg) were significantly(p<0.001) decreased from control values in the amniotic fluids. 3. Urea values of ammniotic fluids in 50mg/kg group are significantly increased from control group. 4. Free fatty acid values of ammniotic fluids in 50mg/kg group are significantly increased from control group.

계장화압입시험법을 이용한 비압흔관찰 브리넬 경도 평가

김성훈,최열,권동일,Kim, Sung-Hoon,Choi, Yeol,Kwon, Dong-Il 대한기계학회 2004 大韓機械學會論文集A Vol.28 No.5

Hardness test is performed for determination of the other properties, such as strength, wear resistance and deformation resistance, as well as hardness itself. And it is performed for prediction of residual lifetime by analysis of hardness reduction or hardness ratio. However, hardness test has limitation that observation of residual indent is needed for determination of hardness value, and that is the reason for not to be widely used in industrial field. Therefore, in this study, we performed researches to obtain Brinell hardness value from quantitative numerical formula by analysing relationship between indentation depths from indentation load-depth curve and mechanical properties such as work hardening exponent, yield strength and elastic modulus.

감압 감열 기록용 Fluorane계 색소의 합성과 전기변색성

김성훈,배진석,황석환,송한철,권태선,도명기,Kim, Sung Hoon,Bae, Jin Seok,Hwang, Seok Hwan,Song, Han Chul,Gwon, Tae Sun,Doh, Myung Ki 대한화학회 1996 대한화학회지 Vol.40 No.3

Fluorane dyes has been widely used for pressure and heat sensitive recording system as color forming materials. A new method of synthesizing fluorane dye by the Bamberger reaction has been developed. Electorchromic properties of fluorane dyes was discussed. The fading reaction kinetics follow a first-order relationship and resolved in two kinetics of first-order reaction with rate constant $k_1$ and $k_2$.

E . coli 의 Tryptophan 오페론 재조합 프라스미드의 불안정성에 관한 연구

김성훈,최영철,유두영,이세영 ( Sung Hoon Kim,Young Chul Choi,Dewey D . Y . Ryu,Se Yong Lee ) 생화학분자생물학회 1982 BMB Reports Vol.15 No.4

pBR322 and trp operon from φ80 trp or ColEl-trp was covalently joined by T4 ligase and introduced into E. coli JA221 r_k^-m_k^+ ΔtrpE5 recA, and the recombinant was selected on the VB minimal plate containing ampicillin (50 ㎍/㎖) and tetracycline (10 ㎍/㎖), The growth rate of transformants obtained was very low and they lost their trp^+ marker very rapidly. In MV12/ pVH5, when host repression system of the tryptophan biosynthesis was partially derepressed with indoleacrylic acid, the enzyme activity of trp operon was increased but the stability of pVH5 was inversely decreased with the concentration of indoleacrylic acid added. In the glucose limited continuous culture of this strain, trp variant began to appear after about 30 generations and the trp fraction increased gradually. Trp cells isolated from cultures grown under various conditions have lost their entire plasmids or arbored modified plasmids which increased or decreased in molecular weight compared to original pVH5.

Ethylenethiourea의 임신랫트에 있어서 기관형성기 투여시험 1. 기형발생과 양수내의 아미노산 및 단백질 함량에 미치는 영향

김성훈,허린수,Kim, Sung-hoon,Huh, Rhin-soo 대한수의학회 1991 대한수의학회지 Vol.31 No.4

This study was carried out to investigate the amino acid and protein concentrations in amniotic fluid and the potency of the teratogenic effect of ethylenethiourea(2-imidazolidinethione, ETU) in the fetuses due to different dose amounts of this compound. The S.P.F. Sprague-Dawley female rats(10 weeks) were used in this study and these animals were divided into four groups; control group(25pregnant female rats), group I (dosed ETU from day 7 to day 17 of gestation at 10mg/kg/day), group II (dosed ETU from day 7 to day 17 of gestation at 30mg/kg/day), group III (dosed ETU from day 7 to day 17 of gestation at 50mg/kg/ day). 250mg/100mg ETU in group I, 750mg/100ml ETU in group II and 1,250mg/100ml ETU in group III were administered 4ml/kg 13.W by oral route. The results obtained were summarized as follows; 1. The anomalies of the external examination werf meningocele in the head, kinky tail, clubfoot and sharp tail.(Meningocele, in group III, significantly increased from control value at p<0.001). 2. The skeletal variations and delayed ossification were Lumbar ribs, asymmetric sternebrae, asymmetric 13th rib and delayed ossification of skull. Asymmetric sternebrae(group III ) was significantly increased from control value at p<0.05 and delayed ossification of skull (group II and III ) were significantly increased from control value at p<0.05 and p<0.01, respectively. 3. The internal soft tissue anomalies were hydroencephaly of 3th lateral ventricle, dilatation of ureter, dilatation of renal pelvis and cleft palate. (Hydroencephaly, 28.1% in group I, 88.3% in group II and 100% in group III ). 4. Protein values in amniotic fluids are not significantly decreased in 10mg/kg group but significantly(p<0.05) decreased in 30mg/kg group and 50mg/kg group from control group. 5. In the levels of amino acid in amniotic fluids, the levels of glntamic acid, iso-lencine, leucine, tyrosine and phenylalanine of 10mg/kg group are significantly decreased from control group. In 50mg/kg group, except for glycine, valine and methionine, all amino acid levels are significantly(p<0.05) decreased from control group.