• Journal of Magnetics
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• v.8 no.4
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• pp.146-148
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• 2003

Multilayered films of Co/Pd have been studied as a candidate material for a high density perpendicular recording medium due to higher anisotropy energy. However, high exchange coupling among grains results in large transition noise. To reduce the exchange coupling and grain size, addition of 3rd elements and physical separation of grains have been attempted. In the present paper, effects of sputtering pressure, Co sublayer thickness and Pd underlayer thickness on magnetic properties and microstructures were studied. It was found that by increasing sputtering pressure from 5 mTorr to 25 mTorr, Ms decreased to one half and coercivity increased more than 5000 Oe. The increase of the coercivity is associated with physical separation of grains by high pressure sputtering. Ms per volume of Co for Co/Pd multilayered film deposited at 25 mTorr shows continuous decrease with increasing Co sublayer thickness. This was related to void formation and intermixing of Co/Pd interface. Also, effect of Pd underlayer thickness on magnetic properties will be discussed.

• Nuclear Engineering and Technology
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• v.45 no.3
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• pp.415-420
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• 2013

A determination method for $^{237}Np$ in spent nuclear fuel samples was developed using an isotope dilution method with $^{239}Np$ as a spike. In this method, inductively coupled plasma mass spectrometry (ICP-MS) was taken for the $^{237}Np$ instead of the previously used alpha spectrometry. $^{237}Np$ and $^{239}Np$ were measured by ICP-MS and gamma spectrometry, respectively. The recovery yield of $^{237}Np$ in synthetic samples was $95.9{\pm}9.7$% (1S, n=4). The $^{237}Np$ contents in the spent fuel samples were 0.15, 0.25, and $1.06{\mu}g/mgU$ and these values were compared with those from ORIGEN-2 code. A fairly good agreement between the measurements (m) and calculations (c) was obtained, giving ratios (m/c) of 0.93, 1.12 and 1.25 for the three PWR spent fuel samples with burnups of 16.7, 19.0, and 55.9 GWd/MtU, respectively.

• Korean Journal of Plant Tissue Culture
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• v.28 no.4
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• pp.205-208
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• 2001

This study was conducted to improve the regeneration efficiency from seed-derived calli of rice by optimizing the copper concentrations in the media. Mature seeds were cultured on MS medium supplemented with copper sulphate (0 to 5.0 mg/L) and 2 mg/L 2,4-D. Callus growth was influenced by the levels of copper sulphate containing with medium, The addition of copper sulphate (2.5 mg/L) in regeneration medium enhanced dramatically the ability of plant regeneration from seed-derived calli. The mean frequency of plant regeneration of 6 indica rices was 27.4% on medium containing copper sulphate, whereas that of the cultivars on copper-free medium was 2.4%. These results suggest that copper sulphate may have an important role in improving regeneration ability of indica rices.

• Current Optics and Photonics
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• v.4 no.4
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• pp.273-276
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• 2020

We report on the relationship between output current for quadrant photodetector (QPD) and bias voltage in silicon-based p-i-n (positive-intrinsic-negative) QPD examined using millisecond pulse laser (ms pulse laser) irradiation. The mechanism governing the relationship was further studied experimentally. The output current curves were obtained by carrying out QPD under different bias voltages (0-40 V) irradiated by ms pulse laser. Compared to other photodetectors, the relaxation was created in the output current for QPD which is never present in other photodetectors, such as PIN and avalanche photodetector (APD), and the maximum value of relaxation was from 6.8 to 38.0 ㎂, the amplitude of relaxation increases with bias value. The mechanism behind this relaxation phenomenon can be ascribed to the bias voltage induced Joule heating effect. With bias voltage increasing, the temperature in a QPD device will increase accordingly, which makes carriers in a QPD move more dramatically, and thus leads to the formation of such relaxation.

• Mass Spectrometry Letters
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• v.10 no.2
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• pp.50-55
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• 2019

The fragmentation statistics of ion trap CID (Collision-Induced Dissociation) spectra using 87,661 tandem mass spectra of doubly charged tryptic peptides are analyzed here. In contrast to the usual method of using intensity information, the frequency of occurrence of fragment ions, with respect to the position of the cleavage site and the residues at these sites is studied in this paper. The analysis shows that the frequency of occurrence of fragment ion peaks is more towards the middle of the peptide than its ends. It was noted that amino acid with an aromatic and basic side chain at N- & C- terminal end of the peptide stimulates more peaks at the lower end of the spectrum. The residue pair effect was shown when the amide bond occurs between acidic and basic residues. The fragmentation at these sites (D/E-H/R/K) stimulates the generation of the y-ion peak. Also, the cleavage site H-H/R/K stimulates the generation of b-ions. K-P environment in the peptide sequence has more tendency to generate y-ions than b-ions. Statistical analysis helps in the visualization of the CID fragmentation pattern. Cleavage pattern along the length of the peptide and the residue pair effects, enhance the knowledge of fragmentation behavior, which is useful for the better interpretation of tandem mass spectra.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.223.2-223.2
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• 2003

A rapid, sensitive and selective liquid chromatography-tandem mass spectrometric (LC/MS/MS) method for the determination of eupatilin in human plasma was developed. Eupatilin and internal standard, (S)-[N-3-(4-(2-(1-methyl-5-tetrazolyl)-pyridine-5-y1)- 3-fluorophenyl)-2-oxo-5-oxazolidinyl]methyl acetamide (DA-7867) were extracted from human plasma by liquid-liquid extraction and analyzed on a phenyl-hexyl column with the mobile phase of acetonitrile-ammonium formate (10 mM, pH 3.0) (60:40, v/v). (omitted)

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.32 no.4
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• pp.371-380
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• 2022

Objectives: To ensure that employers handling petroleum compounds understand whether petroleum-based UVCB (unknown or variable composition, complex reaction products, or biological materials) substances contain hazardous substances and comply with the Occupational Safety and Health Act, petroleum-based UVCB substances were analyzed and the results from samples were compared with MSDS (Material Safety Data Sheet) contents. Methods: Twenty-one petroleum samples were analyzed using GC-MS (Gas Chromatography-Mass Spectrometry), targeting ten volatile organic compounds regulated by the Occupational Safety and Health Act. Results: The target chemicals were detected in 13 out of 21 samples. All 13 samples were in the naphtha (low boiling point naphthas (gasolines)) group. There were also naphtha group samples containing 2% benzene. Some naphtha samples used as solvents contained about 1% benzene. Conclusions: This study shows that naphtha group petroleum substances contain hazardous chemicals in many cases. In particular, if benzene, n-hexane, and toluene with low occupational exposure limits are contained above the limit concentration. Such information should be delivered in the article on MSDS legal regulations.

• Journal of Information Processing Systems
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• v.18 no.1
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• pp.97-114
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• 2022

Interest is increasing in electrocardiogram (ECG) signal analysis for embedded devices, creating the need to develop an algorithm suitable for a low-power, low-memory embedded device. Linear approximation of the ECG signal facilitates the detection of fiducial points by expressing the signal as a small number of vertices. However, dynamic programming, a global optimization method used for linear approximation, has the disadvantage of high complexity using memoization. In this paper, the calculation area and memory usage are improved using a linear approximated template. The proposed algorithm reduces the calculation area required for dynamic programming through local optimization around the vertices of the template. In addition, it minimizes the storage space required by expressing the time information using the error from the vertices of the template, which is more compact than the time difference between vertices. When the length of the signal is L, the number of vertices is N, and the margin tolerance is M, the spatial complexity improves from O(NL) to O(NM). In our experiment, the linear approximation processing time was 12.45 times faster, from 18.18 ms to 1.46 ms on average, for each beat. The quality distribution of the percentage root mean square difference confirms that the proposed algorithm is a stable approximation.

• Korean Journal of Plant Resources
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• v.35 no.6
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• pp.770-777
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• 2022

The main objective of this study was to identify the most appropriate condition for root formation of in vitro micropropagated pear (Pyrus spp.) plants. In vitro propagation was induced on Murashige and Skoog (MS) medium with 2.0 mg/L of N6-benzyladenine (BA) and 0.2 mg/L of Indole-3-butyric acid (IBA) medium. The short pre-treatment of explants with a high concentration (1 mg/L) of NAA and IBA (R0 medium) in dark for three days, followed by transfer to five different media (R1 to R5) resulted in good rooting responses in the pear 'Oharabani (P. pyrifolia × P. communis)' genotype. For the rooting experiments, the highest rooting percentage (83.3 ± 8.3%), average root length (3.6 ± 1.9 mm), total root number (31 ± 4.0), and average root number per plant (2.6 ± 2.1) were obtained on half strength (1/2) of MS medium supplemented with 30 g/L sucrose without hormones and activated charcoal (AC) (R1 medium). The highest rooting percentage was obtained at 83.3% from explants on R1 and R3 media. The rooting procedure described in this study resulted in good root formation and significantly shorting the root induction time to within 14 days of culture. Further studies are underway to test the suitability of the protocol developed in this study for other pear genotypes.

• Progress in Superconductivity and Cryogenics
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• v.11 no.3
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• pp.1-5
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• 2009

It is important to predict AC loss in $Nb_3Sn$ and NbTi cable-in-conduit-conductor (CICC) reliably for the design and operation of large superconducting coils. The hysteresis loss in the superconducting filaments and coupling loss within strands and among strands in a cable or composite are dominant ac losses in superconducting magnets. The coupling loss in a superconductor can be characterized by identifying the coupling constant time $n{\tau}$. To reduce the coupling loss, all the strands (superconductor and Cu) in KSTAR (Korea Superconducting Tokamak Advance Research) are chromium plated with thickness of $l{\pm}0.5{\mu}m$. The ac losses of PF1, PF5 and PF6 coils has been measured by calorimetric method while applying trapezoidal current pulses with various ramp rate from 0.5 kA/s to 2 kA/s. The coupling time constants for $Nb_3Sn$ coils are $25{\sim}55$ ms and the values are not co-related with the coil size, the time constants for NbTi coil is 30 ms.