• Title/Summary/Keyword: $^{16}N$

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Fatty Acid Compositions of Sea Algaes in the Southern Sea Coast of Korea (남해안 해조류의 지방산 조성)

  • 최강주;최선남
    • The Korean Journal of Food And Nutrition
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    • v.15 no.1
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    • pp.58-63
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    • 2002
  • Lipid contents and fatty acid compositions of 16 kind sea algaes in the southern sea coast of Korea were analyzed to evaluate nutrient significance of total polyene, n-3 polyenes and n-6 polyene fatty acids. Total lipid contents were 0.58 ∼ 3.00% in 9 kinds of brown algaes, 0.47 ∼ 2.16% in 5 kinds of red algaes and 0.55 ∼2..99% in 2 kinds of green algeas. N-3 polyenes and n-6 polyenes of the fatty acid compositions were 1.46∼25.67% and 0∼48.51% in the brown algaes, 1.17∼21.91% and 0.28 ∼29.35% in the red algaes, and 3.67%∼ 10.61% and 4.10 ∼ 8.66% in the green algaes, respectirely. The fatty acid contents and compositions of n-3 polyenes and n-6 polyenes, monoenes and saturates were vary different in the algae groups and sepecies.

A First Principles Calculation of the Coherent Interface Energies between Group IV Transition Metal Nitrides and bcc Iron (IV족 천이금속 질화물과 bcc Fe간 계면 에너지의 제일원리 연구)

  • Chung, Soon-Hyo;Jung, Woo-Sang;Byun, Ji-Young
    • Korean Journal of Materials Research
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    • v.16 no.8
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    • pp.473-478
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    • 2006
  • The coherent interface energies and misfit strain energies of Fe/XN (X=Ti, Zr, Hf) systems were calculated by first principles method. The interface energies in Fe/TiN, Fe/ZrN and Fe/HfN systems were 0.343, 0.114, and 0.030 $J/m^2$, respectively. Influence of bond energy was estimated using the discrete lattice plane/nearest neighbor broken bond(DLP/NNBB) model. It was found that the dependence of interface energy on the type of nitride was closely related to changes of the bond energies between Fe, X and N atoms before and after formation of the Fe/XN interfaces. The misfit strain energies in Fe/TiN, Fe/ZrN, and Fe/HfN systems were 0.239, 1.229, and 0.955 eV per 16 atoms(Fe; 8 atoms and XN; 8 atoms). More misfit strain energy was generated as the difference of lattice parameters between the bulk Fe and the bulk XNs increased.

Effective Channel Mobility of AlGaN/GaN-on-Si Recessed-MOS-HFETs

  • Kim, Hyun-Seop;Heo, Seoweon;Cha, Ho-Young
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.16 no.6
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    • pp.867-872
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    • 2016
  • We have investigated the channel mobility of AlGaN/GaN-on-Si recessed-metal-oxide-semiconductor-heterojunction field-effect transistors (recessed-MOS-HFET) with $SiO_2$ gate oxide. Both field-effect mobility and effective mobility for the recessed-MOS channel region were extracted as a function of the effective transverse electric field. The maximum field effect mobility was $380cm^2/V{\cdot}s$ near the threshold voltage. The effective channel mobility at the on-state bias condition was $115cm^2/V{\cdot}s$ at which the effective transverse electric field was 340 kV/cm. The influence of the recessed-MOS region on the overall channel mobility of AlGaN/GaN recessed-MOS-HFETs was also investigated.

Role of Diffusion-weighted MR Imaging in Children with Various Brain Pathologies

  • 최성훈;구현우;고태성;나영신;강신광;김태형
    • Proceedings of the KSMRM Conference
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    • 2003.10a
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    • pp.99-99
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    • 2003
  • To exhibit our clinical experience of diffusion-weighted (DW) MR imaging for various brain pathologies and to determine its role in characterizing brain pathologies in children. DW images in 177 children (M:F=96:81, mean age, 4.7 years) with various brain pathologies were retrospectively collected over past 3 years. DW images (b value: 1000 s/mm) were reviewed along with corresponding apparent diffusion coefficient (ADC) maps. Brain pathologies included cystic or solid brain tumor (n = 55), cerebral infarct (n = 32), cerebritis with or without brain abscess (n = 21), metabolic or toxic brain disorder (n = 19), demyelinating disease (n = 16), hypoxic-ischemic encephalopathy (n = 16), intracerebral hemorrhage including traumatic brain lesion (n = 15), and posterior reversible leukoencephalopathy (n = 3). We reviewed whether DW images and ADCmaps contribute to further characterization of brain pathologies by defining a chronological age of lesions, the presence of cytotoxic edema in lesions, and the nature of cystic lesions.

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Effect on N Defect in Cu-doped III-nitride Semiconductors

  • Kang, Byung-Sub;Lee, Jae-Kwang;Lim, Yong-Sik;Song, Kie-Moon;Chae, Kwang-Pyo
    • Journal of Magnetics
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    • v.16 no.4
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    • pp.332-336
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    • 2011
  • We studied the effect on the electronic and magnetic properties of the N defect in clean and Cu-doped wurtzite III-nitrides by using the first-principles calculations. When it is doped two Cu atoms in the nearest neighboring sites, the system of AlN, GaN, or InN with the N vacancy is energetically more favorable than that without the N vacancy site. When the Cu concentration increases, the total magnetic moment of a supercell becomes small. The ferromagnetism of Cu atom is very low due to the weak 3d-3d coupling. It is noticeable that the spin-exchange interaction between the Cu-3d and N defect states is important.

Synthesis of AlN Powders from AlOOH (AlOOH로부터 AlN분말의 합성)

  • Lee, Jae-Bum;Kim, Seon-Tai
    • Korean Journal of Materials Research
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    • v.16 no.12
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    • pp.771-776
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    • 2006
  • In this study, we report a method to synthesize the aluminum nitride (AlN) powders from aluminum oxyhydroxide (AlOOH). AlOOH powders were prepared from the aluminum hydroxide ($Al(OH)_3$) by heattreatment at the reaction temperature of $350^{\circ}C$. Simple heat treatment of AlOOH in the flow of $NH_3$ gas leads to the formation of hexagonal AlN powders through intermediate conversion of ${\delta}-,\;{\gamma}-$ and ${\alpha}-Al_2O_3$. The FTIR transmission spectra show a broad peak related to Al-N bonds centered around 690 $cm^{-1}$ confirming the presence of AlN. The major peaks in Raman spectra were observed in 250 $cm^{-1}$ and 659 $cm^{-1}$. From the results, synthesized powders from the AlOOH powders were confirmed AlN powders.

Evaluate the diagnostic accuracy in the assessment of coronary artery stenoses using MDCT (MDCT를 이용한 관상동맥협착 진단의 정확성 평가)

  • Yang, Won-Seok;Sin, Sung-Gyu;Park, Jae-Hong
    • Journal of the Korean Society of Radiology
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    • v.6 no.4
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    • pp.275-279
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    • 2012
  • Methods and results : The suspected patient who have results of CTA and CAG examinations to evaluate coronary stenose to undergo each 16MD CT(n=93) and dual source CT(n=100). As a results of statistic, the highest rank of sensitivity, specificity, PPV, NPV and accuracy in coronary artery with using 16MDCT was displayed in LAD(73.5%), RCA(74.5%), LAD(66.7%), LCX(75%), LCX(67.7%). The mean diagnostic accuracy of dual source CT was more 17% than 16MDCT. Dual source CT was recorded 84% mean of accuracy. In addition to, segments of coronary artery did not show significant differences in all of them. However, distal segment become more and more accurate than proximal site.

Deodorization of Fish Oil Using Adsorption Method (흡착법을 이용한 어유의 탈취)

  • 김귀식;배태진
    • Journal of Life Science
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    • v.13 no.3
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    • pp.365-373
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    • 2003
  • Instead of deodorization appararus of fish oil, an adsorbent such as activated charcoal, activated alumina, silicagel, bamboo charcoal was packed in column alone or mixed with preparative ratio, and then test the effective deodorization with bleaching. In the progress of degumming, the effective method was 18 ml of 2.5% oxalic acid per 100m1 of crude large anchovy oil. The optical condition to deacidified was treating for 30 min at $40^{\circ}C$ with 2.5% sodium hydroride solution. The effective deodorization was added with 3% silicagel under the alone treating adsorbent, and mixed treating was 30% activated alumina and 10% silicagel but added to green tea powder was not effective. The major fatty acid of total lipid were 16:0, 20:5n-3, 18:1n-9, 16:1n-7 and 22:6n-3 after treatment of degumming, deacidfication and deodorizing in the large anchovy oil. The oxidative stability of refined anchovy oil added to $\alpha$-tocopherol was validated 20 days under the control, and 30 days in the case of $\alpha$-tocopherol. The 0.01% $\alpha$-tocopherol was more effective than 0.02% $\alpha$-tocopherol.

Characteristics and Fabrication of Vertical Type Organic Light Emitting Transistors Using n-Type Organic Materials (N형 유기물질을 이용한 세로형 유기 발광트랜지스터의 제작 및 특성에 관한 연구)

  • Oh Se-Young;Kim Hee-Jeong;Jang Kyoung-Mi
    • Polymer(Korea)
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    • v.30 no.3
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    • pp.253-258
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    • 2006
  • We have fabricated vortical type organic thin film transistors (OTFTs) consisting of ITO/n type active material/Al gate/n type active material/Al using F16CuPc, NTCDA, PTCDA and PTCDI C-8. The effect of mobility of n type active materials and thin film thickness on current-voltage (I-V) characteristics and on/off ratios were investigated. The vortical type organic transistor using PTCDI C-8 exhibited low operation voltage and high on-off ratio. In addition, we have investigated the feasibility of application in organic light emitting transistor using light emitting polymer. Especially, the light emitting transistor consisting of ITO/PEDOT-PSS/P3HT/F16CuPc/Al gate/F16CuPc/Al showed the maximum quantum efficiency of 0.054.

High-temperature Oxidation of CrZrN Films in Air (CrZrN 박막의 대기 중 고온산화)

  • Kim, Min-Jeong;Hwang, Yeon-Sang;Bong, Seong-Jun;Lee, Sang-Yul;Lee, Dong-Bok
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2012.05a
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    • pp.167-168
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    • 2012
  • Films of CrN, $Cr_{40}Zr_9N$, and $Cr_{31}Zr_{16}N$ were deposited on a steel substrate by closed field unbalanced magnetron sputtering, and their oxidation behaviors at $700^{\circ}C$ and $800^{\circ}C$ for up to 60h in air were investigated. All the deposited films were composed of the CrN phase. Zirconium atoms in $Cr_{40}Zr_9N$ and $Cr_{31}Zr_{16}N$ films partially dissolved in the CrN phase. They advantageously refined the columnar structure, reduced the surface roughness, and increased the microhardness. The CrN film displayed relatively good oxidation resistance, owing to the formation of the highly protective $Cr_2O_3$ on its surface. The $Cr_{40}Zr_9N$ and $Cr_{31}Zr_{16}N$ films oxidized to $Cr_2O_3$ as the major phase and ${\alpha}-ZrO_2$ as the minor one. They oxidized primarily by the inward transport of oxygen. The addition of Zr could not increase the oxidation resistance of the CrN film, because the formed $ZrO_2$ that was intermixed in the $Cr_2O_3$-rich oxide layer was oxygen permeable, and developed the compressive stress in the oxide scale owing to the volume expansion during its formation.

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