• Title/Summary/Keyword: $^{14}C$ and $^{15}N$

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Fatty Acid Composition of Salt-Fermented Seafoods in Chonnam Area (전남산 젓갈의 지방산 조성)

  • 박복희;박영희
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.22 no.4
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    • pp.465-469
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    • 1993
  • This study was designed to investigate fatty acid composition of salt-fermented seafoods in Chonnam area. The seven samples were analyzed for fatty acid composition. The contents of lipid was highest in salt-fer-mented anchovies and followed by salt-fermented small mullets, salt-fermented oysters, salt-fermented sea-arrows and salt-fermented small shrimps. The ratio of fatty acid composition depended on the samples but the major fatty acids were $C_{l6:0}$, $C_{20:5}$, $C_{l6:1}$, $C_{22:6}$, and $C_{l8:1}$ among all samples. The composition of n-3 polyunsaturated fatty acids was highest in salt-fermented sea-arrows (39.11%) and followed by salt-fermented small shrimps, salt-fermented oysters, salt-fermented anchovies and salt-fermented small mullets. In n-3 polyunsaturated fatty acids, $C_{20:5}$ was relatively abundant in salt-fermented oysters (17.71%) and salt-fermented sea-arrows (16.38%), and $C_{22:6}$ in salt-fermented sea-arrows (22.22%) and salt-fermented small shrimps (15.13~21.50%). However, $C_{22:6}$ was very little in salt-fermented small mullets.l mullets.

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Simulation Study of ion-implanted 4H-SiC p-n Diodes (이온주입 공정을 이용한 4H-SiC p-n Diode에 관한 시뮬레이션 연구)

  • Lee, Jae-Sang;Bahng, Wook;Kim, Sang-Cheol;Kim, Nam-Kyun;Koo, Sang-Mo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.22 no.2
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    • pp.128-131
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    • 2009
  • Silicon carbide (SiC) has attracted significant attention for high frequency, high temperature and high power devices due to its superior properties such as the large band gap, high breakdown electric field, high saturation velocity and high thermal conductivity. We performed Al ion implantation processes on n-type 4H-SiC substrate using a SILVACO ATHENA numerical simulator. The ion implantation model used Monte-Carlo method. We simulated the effect of channeling by Al implantation in both 0 off-axis and 8 off-axis n-type 4H-SiC substrate. We have investigated the effect of varying the implantation energies and the corresponding doses on the distribution of Al in 4H-SiC. The controlled implantation energies were 40, 60, 80, 100 and 120 keV and the implantation doses varied from $2{\times}10^{14}$ to $1{\times}10^{15}\;cm^{-2}$. The Al ion distribution was deeper with increasing implantation energy, whereas the doping level increased with increasing dose. The effect of post-implantation annealing on the electrical properties of Al-implanted p-n junction diode were also investigated.

Synthetic Studies on Carbapenam Skeletons

  • 구양모;서민효;이윤영
    • Bulletin of the Korean Chemical Society
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    • v.17 no.10
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    • pp.909-918
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    • 1996
  • Syntheses of carbapenam skeletons were achieved from 1,3-propanediol through 1,3-dipolar cycloaddition. 3-(Tetrahydropyran-2-yloxy)-(10) and 3-(t-butyldimethylsilyloxy) propanal (13) were obtained from 1,3-propanediol. 3-Hydroxypropanals (10, 13, 14) were reacted with N-hydroxyglycine esters to give C-(2-hydroxyethyl)-N-alkoxycarbonylmethylnitrones (15a-15d). 1,3-Dipolar cycloaddition of the nitrones with methyl acrylate or ethyl crotonate gave 3-(2-hydroxyethyl)isoxazolidines (16a-16b, 17a-17b, 18, 19a-19b). 3-(2-Hydroxyethyl)isoxazolidines (17a, 17c, 19a, 19b) were converted to 3-(2-iodoethyl)isoxazolidines (21a-21d) or 3-phenylthiocarbonylmethylisoxazolidines (25a-25d) which were cyclized to give 2-oxa-1-azabicyclo[3.3.0]octanedicarboxylates (22a-22d, 26a-26d). 2-Oxa-1-azabicyclo[3.3.0]octane-4,8-dicarboxylates (22c-22d, 26c-26d) were transformed to 6-(l-hydroxyethyl)carbapenam-3-carboxylates (30a-30b, 31a-31b).

The effect of $Nd_2O_3$ addition on the microwave dielectric properties of the BSST ceramics (BSST계 세라믹스의 마이크로파 유전특성에 미치는 $Nd_2O_3$ 첨가 효과)

  • 박인길;류기원;배선기;이영희
    • Electrical & Electronic Materials
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    • v.9 no.5
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    • pp.439-444
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    • 1996
  • 0.15(B $a_{0.95}$ S $r_{0.05}$)O-0.15(S $m_{2(1-x}$/N $d_{2x}$) $O_{3}$-0.7Ti $O_{2}$(x=0-10[m/o]) ceramics were fabricated by mixed oxide method. Microwave dielectric properties were investigated with contents of N $d_{2}$ $O_{3}$. In the case of specimen with N $d_{2}$ $O_{3}$(6[m/o]), dielectric constant, quality factor and temperature coefficient of resonant frequency were 78.14, 2938(at 3[GHz]) and +14.19[ppm/.deg. C], respectively. By comparison its properties with undoped specimen, dielectric constant and quality factor were highly improved, but the temperature coefficient of resonant frequency was increased to positive value......

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Annual Increase in Carbon and Nitrogen Stocks of Trees and Soils in a 'Niitaka' Pear Orchard Following Standard Fertilization Recommendations (표준 시비에 따른 '신고'배 수체 및 재배지 토양의 탄소 및 질소 저장량 변화)

  • Ro, Hee-Myong;Choi, Jin-Ho;Lee, Seo-Yeon;Lee, Tae-Kyu;Kim, Jong-Sung;Park, Ji-Suk;Choi, Jang-Jeon;Lee, Min-Jin
    • Horticultural Science & Technology
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    • v.33 no.4
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    • pp.591-597
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    • 2015
  • We determined the total C and N stocks in trees and soils after 1 year of fertilization in an experimental orchard with 16-year-old 'Niitaka' pear (Pyrus pyrifolia Nakai cv. Niitaka) trees planted at $5.0m{\times}3.0m$ spacing on a Tatura trellis system. Pear trees were fertilized at the rate of 200 kg N, 130 kg P and $180kg\;K\;ha^{-1}$. At the sampling time (August 2013), trees were uprooted, separated into six fractions [trunk, main branches, lateral branches (including shoots), leaves, fruit, and roots] and analyzed for their total C and N concentrations and dry masses. Soil samples were collected from 0 to 0.6 m in 0.1 m intervals at 0.5 m from the trunk, air-dried, passed through a 2-mm sieve, and analyzed for total C and N concentrations. Undisturbed soil core samples were also taken to determine the bulk density. Dry mass per tree was 5.6 kg for trunk, 12.0 kg f or m ain branches, 15.7 kg for lateral branches, 5.7 kg for leaves, 9.8 kg for fruits, and 10.5 kg for roots. Total amounts of C and N per tree were respectively 2.6 and 0.02 kg for trunk, 5.5 and 0.04 kg for main branches, 7.2 and 0.07 kg for lateral branches, 2.6 and 0.11 kg for leaves, 4.0 and 0.03 kg for fruit, and 4.8 and 0.05 kg for roots. Carbon and N stocks stored in the soil per hectare were 155.7 and 14.0 Mg, respectively, while those contained in pear trees were 17.8 and $0.2Mg{\cdot}ha^{-1}$ based on a tree density of 667 trees/ha. Overall, C and N stocks per hectare stored in the pear orchard were 173.6 and 14.2 Mg, respectively. Compared with results obtained in 2012, the amounts of C stocks have increased by $17.7Mg{\cdot}ha^{-1}$, while those of N stocks remained virtually unchanged ($0.66Mg{\cdot}ha^{-1}$).

Structure of a Copper(Ⅱ) Hexaazamacrotricyclic Complex : (1,3,6,9,11,14-Hexaazatricyclo[12.2.1.16,9]octadecane)-copper(Ⅱ) Perchlorate

  • Cheon Manseog;Suh Paik Myunghyun;Shin Whanchul
    • Bulletin of the Korean Chemical Society
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    • v.13 no.4
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    • pp.363-367
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    • 1992
  • The crystal structure of (1,3,6,9,11,14-hexaazatricycol[12.2.1.$1^{6,9}$]octadecane)copper(Ⅱ) perchlorate, Cu($C_{12}H_{26}N_6$)$(ClO_4)_2$, has been determined by the X-ray diffraction methods. The crystal data are as follows: Mr=516.9, triclinic, ${\alpha}=8.572\;(2)$, b=8.499 (3), c=15.204 (3) ${\AA}$, ${\alpha}=80.42\;(5),\;{\beta}=73.57\;(3),\;{\gamma}=69.82\;(4)^{\circ},\;V=994.2\;{\AA}^3,\;D_C=1.726\;gcm^{-3}$, space group $P{\tilde{1}},\;Z=2,\;{\mu}=21.27\;cm^{-1}&, F(000)=534 and T=297 K. The structure was solved by direct methods and refined by full-matrix least-squares methods to and R value of 0.081 for 1608 observed reflections measured with graphite-mono-chromated Mo Ka radiation on a diffractometer. There are two independent complexes in the unit cell. The two copper ions lie at the special positions (1/2, 0, 0) and (0, 1/2, 1/2)and each complex possesses crystallographic center of symmetry. Each Cu ion is coordinated to four nitrogen donors if the hexaazamacrotricyclic ligand and weakly interacts with two oxygen atoms of the perchlorate ions to form a tetragonally distorted octahedral coordination geometry. The Cu_N (sec), Cu_N(tert) and Cu_O coordination distances are 1.985 (14), 2.055 (14) and 2.757 (13) ${\AA}$ for the complex A and 1.996 (10), 2.040 (11) and 2.660 (13) ${\AA}$ for the complex B, respectively. The macrocycles in the two independent cations assume a similar conformation with the average r.m.s. deviation of 0.073 ${\AA}$. Two 1,3-diazacyclopentane ring moieties of the hexaazamacrotricyclic ligand are placed oppositely and almost perpendicularly to the square coordination plane of the ruffled 14-membered macrocycle. The secondary N atoms are hydrogen-bonded to the perchlorate O atoms with distances of 3.017 (23) and 3.025 (19) ${\AA}$ for the complexes A and B, respectively.

Biochemical and Structural Characterization of HP1423 (Y1423_HELPY) from Helicobacter pylori

  • Kim, Ji-Hun;Lee, Ki-Young;Park, Sung-Jean;Lee, Bong-Jin
    • Journal of the Korean Magnetic Resonance Society
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    • v.14 no.1
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    • pp.45-54
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    • 2010
  • HP1423 (Y1423_HELPY) is a conserved hypothetical protein from H. pylori strain 26695. However, Sequence Blast result indicates that HP1423 belongs to S4 (PF01479) superfamily. According to Pfam database, the S4 domain is a small domain consisting of 60-65 amino acid residues, that probably mediates binding to RNA. In this study, we report the sequence-specific backbone resonance assignment of HP1423, which has 84 amino acid residues. We could assign unambiguously about 88% of all $^{1}H_{N}$, $^{15}N$, $^{13}C_{\alpha}$, $^{13}C_{\beta}$ and $^{13}C=O$ resonances. We could not detect the resonances from residues 15-20, and disappearance of these peaks seems to be related with the intermediate-conformational exchange. These assigned NMR peaks of HP1423 can be used for studying the role of protein dynamics in millisecond timescale, and Protein-RNA binding.

The Effects of Precursor on the Formation and Their Properties of Spin-on Dielectric Films Used for Sub-50 nm Technology and Beyond (50 nm 이상의 CMOS 기술에 이용되는 Spin-on Dielectric 박막 형성과 그 특성에 미치는 전구체의 영향)

  • Lee, Wan-Gyu
    • Journal of the Korean Vacuum Society
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    • v.20 no.3
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    • pp.182-188
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    • 2011
  • Polysilazane and polymethylsilazane based precursor films were deposited on Si-substrate by spin-coating, subsequently annealed at $150{\sim}850^{\circ}C$, and characterized. Structural analysis, shrink, compositional change, etch rate, and gap-filling were observed. Annealing the precursor films led to formation of spin-on dielectric films. C-containing precursor films showed that less loss of N, H, and C while less gain of O than that of C-free precursor films at $400^{\circ}C$, but more loss of N, H, and C while more gain of O at $850^{\circ}C$. Thus polysilazane based precursor films exhibited less reduction in thickness of 14.5% than silazane based one of 15.6% at $400^{\circ}C$ but more 37.4% than 19.4% at $850^{\circ}C$. FTIR indicated that C induced smaller amount of Si-O bond, non-uniform property, and lower resistance to chemical etching.

Near-IR Spectroscopic Studies of the Hydrogen Bonding between Thioacetamide and N,N-Dimethylacetamide in $CCl_4$ ($CCl_4$중에서 Thioacetamide와 N,N-Dimethylacetamide사이의 수소 결합에 관한 분광학적인 연구)

  • Kang Bong Lee;Byung-Chul Kim;Chang-ju Yun;O. D. Bonner;Young-Sang Choi
    • Journal of the Korean Chemical Society
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    • v.30 no.6
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    • pp.510-515
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    • 1986
  • Spectra for the $v_3$+ Amide II combination band of thioacetamide(TA) were obtained in carbon tetrachloride solutions and in very dilute solutions of TA-N,N-dimethlylacetamide (DMA) in carbon tetrachloride in the range of 5~55$^{\circ}$C. The combination band in the three component system can be resolved into components due to monomeric TA, 1 : 1 TA-DMA complex and 1 : 2 TA-DMA complex. In the dilute solutions the experimental spectrum was resolved by using the computer into its two Lorentzian-Gaussian product components which have been identified with the monomeric TA and the 1 : 1 complex. The equilibrium constants and thermodynamic parameters of 1 : 1 complex were determined by analysis of concentration and temperature dependent spectra. The ${\Delta}H^{\circ}$ and ${\Delta}S^{\circ}$ for the 1 : 1 complex were -14.4 KJ mol$^{-1}$ and -15.6 J mol$^{-1}deg^{-1}$, respectively.

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Exchange Bias Perpendicular Magnetic Anisotropy and Thermal Stability of (Pd/Co)N/FeMn Multilayer ((Pd/Co)N/FeMn 다층막에서의 교환바이어스 수직자기이방성과 열적안정성)

  • Joo, Ho-Wan;An, Jin-Hee;Kim, Bo-Keun;Kim, Sun-Wook;Lee, Kee-Am;Lee, Sang-Suk;Hwang, Do-Geun
    • Journal of the Korean Magnetics Society
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    • v.14 no.4
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    • pp.127-130
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    • 2004
  • Magnetic properties and thermal stability by exchange biased perpendicular magnetic anisotropy in (Pd/Co)$_{N}$FeMn multilayer deposited by do magnetron sputtering system are investigated. We measured the perpendicular magnetization curves of (Pd(0.8nm)/Co(0.8nm)$_{5}$FeMn multilayer as function of FeMn thickness and annealing temperature. As FeMn thickness increases from 0 to 21nm, the perpendicular exchange bias(Hex) obtained 127 Oe at FeMn thickness 15nm. As the annealing temperature increases to 24$0^{\circ}C$, the E$_{ex}$ increased from 115 Oe to 190 Oe and disappeared exchange biased perpendicular magnetic anisotropy effect at 33$0^{\circ}C$.