• Title/Summary/Keyword: Ba/F3

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Relationship between PAHs Concentrations in Ambient Air and Deposited on Pine Needles

  • Chun, Man-Young
    • Environmental Analysis Health and Toxicology
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    • v.26
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    • pp.4.1-4.6
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    • 2011
  • Objectives: This study was carried out to determine whether or not pine needles can be used as passive samplers of atmospheric polycyclic aromatic hydrocarbons (PAHs) using the correlation between accumulated PAH concentrations in air (Ca, ng/$m^3$) and those deposited on pine needles (Cp, ng/g dry). Methods: PAHs in ambient air was collected using low volume PUF sampler and pine needles was gathered at same place for 7 months. Results: A good correlation ($R^2$=0.8582, p<0.05) was found between Ca and Cp for PAHs with a higher gaseous state in air (AcPy, Acp, Flu, Phen, Ant, Flt, Pyr, BaA and Chry), but there was a poorer correlation ($R^2$=0.1491, p=0.5123) for the PAHs with a lower gaseous state (BbF, BkF, BaP, DahA, BghiP and Ind123). A positive correlation ($R^2$=0.8542) was revealed between the logarithm of the octanol-air partitioning coefficient ($logK_{oa}$) and Cp/Ca for the PAHs with a higher gaseous state in air, but there was a negative correlation ($R^2$=0.8131) for the PAHs with a lower gaseous state. The Ca-Cp model could not be used to estimate PAHs concentrations in air using deposited PAHs concentrations on pine needles, but the logKoa-Cp/Ca model could be used. Conclusions: It was found that pine needles can be used as passive samplers of atmospheric PAHs.

The Microwave Dielectric properties of Low Temperature Firing Temperature Ceramics for Multilayer Dielectric Filter (적층형 유전체 필터를 위한 저온 소결용 마이크로파 유전체 유전특성)

  • 윤중락;이헌용;이석원
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.993-996
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    • 2001
  • In the composition of 0.16BaO-0.15(Nd$\_$0.87/,Bi$\_$0.13/)$_2$O$_3$-0.69TiO$_2$$.$Glass [EG-2782] 3wt% addition sintered at 1080$^{\circ}C$, we could obtained microwave properties of dielectric constant $\varepsilon$$\_$r/= 80.1, quality factor Q ${\times}$ f = 810 (at 3.5 GHz]) and temperature coefficient of resonant frequency $\tau$$\_$f/ = -1.3 [ppm/$^{\circ}C$]

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Spin injection and transport properties of Co/Au/Y$Ba_2$$Cu_3$$O_y$ tunnel junctions

  • Lee, Kiejin;Kim, Sunmi;Ishibashi, Takauki;Cha, Deokjoon
    • Progress in Superconductivity
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    • v.3 no.1
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    • pp.70-73
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    • 2001
  • We report the spin injection and transport properties of three terminal devices of Co/Au/$YBa_2$$Cu_3$$O_{y}$(F/N/S) tunnel junctions by injection of spin-polarized quaiparticles using a cobalt ferromagnetic injector. The observed current gain depends on the thickness of Au interlayer and is directly related to the nonequilibrium magnetization due to spin relaxation effects. The tunnel characteristic of a F/N/S tunnel junctions exhibited a zero bias conductance peak (ZBCP). The suppression of the ZBCP was observed due to the suppression of Andreev reflection at the interface, which is due to the spin scattering processes at the interface between a ferromagnetic and a d-wave superconductor.r.

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Brain Function During Recall of Anger Experience According to the Level of Trait Anger (분노 경험 회상시 특성 분노 수준에 따른 뇌 기능)

  • Eum, Young-Ji;Lee, Kyung Hwa;Sohn, Jin-Hun
    • Science of Emotion and Sensibility
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    • v.21 no.3
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    • pp.49-60
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    • 2018
  • Trait anger is one of the psychological traits associated with experiences of anger. Individuals with high trait anger become angry easily at trivial events, and experience anger more frequently, intensely, and over a longer duration. This study aimed to investigate neural responses during experiences of anger, and identify the neural correlates of trait anger. Thirty five adults participated in the functional magnetic resonance (fMRI) experiment. They were scanned while they recalled an anger-inducing memory that was supposed to evoke an experience of anger. During the angry recall compared to the emotionally neutral recall, our participants showed greater neural activation in the right superior temporal gyrus (BA38), left inferior frontal gyrus (BA45), right thalamus, right insula (BA13), bilateral cuneus (BA17), and right cerebellum anterior lobe. The correlation analysis revealed that trait anger scores were positively associated with right insula activity during the angry recall. Individuals with higher trait anger were more likely to show greater activity in the right insula in response to past experiences of anger, as previously implicated in various studies of emotional processing. This finding suggests that trait anger may be an important factor in modulating anger-related brain activity.

The Electrical Properties of High Voltage Mutilayer Chip Capacitor with X7R by addition of Er2O3 and Glass Frit (고압용 X7R 적층 칩 캐패시터의 Er2O3 및 유리프릿 첨가에 따른 전기적 특성)

  • Yoon, Jung-Rag;Kim, Min-Kee;Chung, Tae-Seog;Woo, Byoung-Chul;Lee, Seog-Won
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.21 no.5
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    • pp.440-446
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    • 2008
  • To manufacture the MLCC with X7R for high voltage stability, $BaTiO_3-MgO-MnO_2-Y_2O_3$ with $(Ba_{0.4}Ca_{0.6})SiO_3$ glass frit was formulated. Based on this composition, the addition of $Er_2O_3$ showed that TCC(Temperature Coefficient Capacitance) at $85^{\circ}C$ was improved from 5 % to ${\sim}0\;%$, but the dielectric constant and IR (Insulation Resistance) were decreased. The glass frit improved the dielectric constant and IR, so the appropriate contents of $Er_2O_3$ and glass frit were 0.6 mol% and 1 wt%, respectively. It showed that the dielectric constant and RC constant were 2,550 and 2,000 (${\Omega}F$), respectively in the sintering condition at $1250^{\circ}C$ in PO2 $10^{-7}$ Mpa. The MLCC with $3.2{\times}1.6$ (mm) size and $1\;{\mu}F$ was also suited for X7R with the above composition.

A comparative study on the impact of Gd2O3 burnable neutron absorber in UO2 and (U, Th)O2 fuels

  • Uguru, Edwin Humphrey;Sani, S.F.Abdul;Khandaker, Mayeen Uddin;Rabir, Mohamad Hairie;Karim, Julia Abdul
    • Nuclear Engineering and Technology
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    • v.52 no.6
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    • pp.1099-1109
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    • 2020
  • The performance of gadolinium burnable absorber (GdBA) for reactivity control in UO2 and (U, Th)O2 fuels and its impact on spent fuel characteristics was performed. Five fuel assemblies: one without GdBA fuel rod and four each containing 16, 24, 34 and 44 GdBA fuel rods in both fuels were investigated. Reactivity swing in all the FAs with GdBA rods in UO2 fuel was higher than their counterparts with similar GdBA fuel rods in (U, Th)O2 fuel. The excess reactivity in all FAs with (U, Th)O2 fuel was higher than UO2 fuel. At the end of single discharge burn-up (~ 49.64 GWd/tHM), the excess reactivity of (U, Th) O2 fuel remained positive (16,000 pcm) while UO2 fuel shows a negative value (-6,000 pcm), which suggest a longer discharge burn-up in (U, Th)O2 fuel. The concentration of plutonium isotopes and minor actinides were significantly higher in UO2 fuel than in (U, Th)O2 fuel except for 236Np. However, the concentration of non-actinides (gadolinium and iodine isotopes) except for 135Xe were respectively smaller in (U, Th)O2 fuel than in UO2 fuel but may be two times higher in (U, Th)O2 fuel due to its potential longer discharge burn-up.

Asymbiotic germination and seedling growth of Calanthe striata f. sieboldii Decne. ex Regel (금새우난초(Calanthe striata f. sieboldii Decne. ex Regel)종자의 비공생 발아 및 신초증식)

  • Bae, Kee Hwa;Kim, Soo-Young
    • Journal of Plant Biotechnology
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    • v.42 no.3
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    • pp.239-244
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    • 2015
  • Calanthe striata f. sieboldii Decne. ex Regel is a terrestrial orchid with beautiful flowers arranged in racemose inflorescences. This species is threatened due to over-collection and loss of suitable habitats. Asymbiotic germination is useful in the conservation efforts to re-establish plants in the wild, and for commercial propagation. In this study, we investigate the effects of sodium hypochlorite (NaOCl), three types of culture media (Phytomax Orchid Maintenance - POM, Seed Germination Maintenance - SGM, and Murashige and Skoog 1962 - MS), and plant growth regulators on embryo swelling, protocorm formation, and embryo diameter of C. striata f. sieboldii. Treatment with 1% NaOCl for 30 min greatly enhanced embryo swelling (28.3%), embryo diameter ($205.8{\mu}m$), and embryo protocorm formation (54.8%) compared to seeds without NaOCl treatment (embryo swelling 8.5%, embryo diameter $14.6{\mu}m$, and protocorm formation 13.4%) on POM medium. Protocorm formation on POM medium supplemented with 1.0 mg/L N6-benzyladenine (BA) (95.6%) was better than the control (54.5%). Additionally, the effects of activated charcoal (AC) and sucrose on seedling growth in in vitro culture were examined. The protocorm converted into healthy plants with well-developed shoot primordia on the POM medium with AC and sucrose. The most suitable conditions for seedling growth after 10 weeks of culture were the POM medium with AC or sucrose. These results show effective asymbiotic seed germination and in vitro seedling growth of C. striata f. sieboldii.

Etching Characteristics BST Thin Film in $CF_4$/Ar Plasma ($CF_4$/Ar 플라즈마에 의한 BST 박막 식각 특성)

  • 김동표;김창일;서용진;이병기;장의구
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.866-869
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    • 2001
  • In this study, (Ba,Sr)TiO$_3$(BST) thin films were etched with a magnetically enhanced inductively coupled plasma(MEICP). Etching characteristics of BST thin films including etch rate and selectivity were evaluated as a function of the etching parameters such as gas mixing ratio, rf power, dc bias voltage and chamber pressure. The maximum etch rate of the BST films was 1700 $\AA$/min at Ar(90)/CF$_4$(10), 600 W/350 V and 5 mTorr. The selectivity of BST to PR was 0.6, 0.7, respectively. To analyze the composition of surface residue remaining after the etching, samples etched with different CF$_4$/Ar gas mixing ratio were investigated with X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS). From the results of XPS and SIMS, there are chemical reaction between Ba, Sr, Ti and C, F radicals during the etching and remained on the surface.

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A study on the fabrication of Y-Ba-Cu-O High Tc superconducting thin film by sputtering system (스퍼터링 방식에 의한 Y-Ba-Cu-O 고온 초전도 박박의 제작에 관한 연구)

  • Chae, Kee-Byung;Kang, Ki-Sung;Soh, Dae-Wha
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1992.11a
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    • pp.81-83
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    • 1992
  • The superconducting thin films deposited on $SiO_x$ substrate by R.F magnetron sputter using $YBa_2Cu_3O_x$ single target have been made and annealed at $940^{\circ}C$ for 30 min. The thickness of films were 1000-2000${\AA}$ with a rate of 20-25${\AA}/min$ and superconducting properties of thin films depended on the compositions of pre-annealed the thin films. It has been analyzed by SEM photo-analysis and X-ray diffraction patterns of these samples obtained under the various conditions of this sputtering methods. and recognized the supperconducting thin films by electric properties.

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Clinical Application of Functional MRI : Motor Cortex Activities by Acupuncture

  • Choe, Bo-Young
    • Journal of the Korean Magnetic Resonance Society
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    • v.6 no.2
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    • pp.89-93
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    • 2002
  • We report a preliminary fMRI evidence of modulation of somatomotor areas by acupuncture in GB34 acupoint. GB34, located in the back of the knee, is known to be effective in recovering motor function after stroke. Using 3T MR scanner, functional MR imaging was performed in five normal volunteers in two stimulation paradigms; acupuncture manipulation on GB34 and sham points. Group analysis form five individuals showed that bilateral sensorimotor areas (BA 3,4,6 and 7) showed stimulation related BOLD signal contrast of approximately 6% whereas very few areas were activated when sham stimulation is given. Our results suggest that acupuncture fMRI study can be safely conducted in 3T environment and stimulation in GB34 modulate the cortical activities of the somatomotor area in human.

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