• Archives of Pharmacal Research
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• 제11권1호
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• pp.74-79
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• 1988

Crystals of tolazamide, $C_{14}H_{21}N_3O_3S$, are triclinic space group $P{\bar{1}}$ with cell dimensions of a = 6.355 (2), b = 9.223 (2), c = 13.510 (3) A, ${\alpha}\;=\;101.04\;(8),\;{\beta}=92.80(5),\;{\gamma}\;=\;85.72\;(6)^{\circ}$ and Z = 2. Intensities were collected on an automated four-circle diffractometer using graphite-monochromated Cu K ${\alpha}$ radiations. The structure was solved by direct method and refined by full-matrix least-squares to an R factor of 0.058 for 1184 observed reflections. The molecules are dimerized by the $N-H{\cdots}O$ hydrogen bonds. There are only van der Waals interactions between these molecular dimers.

• KIEE International Transactions on Electrophysics and Applications
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• 제3C권6호
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• pp.211-215
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• 2003

Alternating current (AC) losses of two Bi-2223 ([Bi, Pb] : Sr : Ca : Cu :O = 2:2:2:3) tapes [one untwisted (Tape I, twist-pitch of $\infty$ mm) and the other with a twist-pitch of 8mm (Tape II) ] were measured and compared. These samples, produced by the powder-in-tube (PIT) method, are multi-filamentary and have a Ag/Au and Ag matrix, respectively. Susceptibility measurements were conducted while cooling in a magnetic field. Flux loss measurements were conducted as a function of ramping rate, frequency and field direction. The AC flux loss increases as the twist-pitch of the tapes decreased, in agreement with the Norris Equation.

• Journal of Magnetics
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• 제6권3호
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• pp.94-100
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• 2001

Fe-Co-Ni particles with an average size of 45 and 135 nm are characterized in terms of magnetic phase transformation and magnetic properties at room temperature. BCC structure of Fe-Co-Ni spherical particles can be synthesized from Fe-Co-Ni-Al-Cu precursor films by heating at 600-80$0^{\circ}C$ for the phase separation of Fe-Co rich Fe-Co-Ni particles, followed by a post heating at $600^{\circ}C$ for 5 hours. The average size of nanoparticles was directly determined by the thickness of precursor films. Exchange interactive hysteresis was observed for the nano-composite (Fe-Co-Ni)+(Fe-Ni-Al) films resulting from the short exchange interface between ferromagnetic Fe-Co-Ni particles surrounded by almost papramagnetic Ni-Al-Fe matrix. Arraying the isolated Fe-Co-Ni nano-particles in a random arrangement on $Al_2O_3$substrate the particle assembly showed a behavior of dipole interactive ferromagnetic clusters depending on their volume and inter-particle distance.

• Bulletin of the Korean Chemical Society
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• 제24권5호
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• pp.555-558
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• 2003

An enrichment/separation system for atomic absorption spectrometric determinations of Cu(Ⅱ), Fe(Ⅲ), Ni(Ⅱ) and Co(Ⅱ) has been established. The procedure is based on the adsorption of the analytes as calmagite chelates on Chromosorb-102. The effects of some parameters including pH, amount of ligand, salt matrix, flow rates of sample and eluent solutions were investigated. Under optimized conditions, the relative standard deviation of the combined method of sample treatment, preconcentration and determination with FAAS (N=5) is generally lower than 5%. The limit of detection (3σ) was between 6.0-112.9 ㎍/L. The results were used for preconcentration of analytes from some sodium and ammonium salt.

• 약학회지
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• 제47권6호
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• pp.356-360
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• 2003

Nitroso-2-naphthol-3,6-disulfonic acid, disodium salt (NRS) was used as an organic ligand to prepare basic drug-selective polymeric membrane electrode. The sensing membrane of the electrode consited of basic drug-meta1(II)-NRS as an ion-exchanger site in a poly(vinyl chloride) matrix plasticized with 2-nitrophenyl octyl ether (NPOE). The metal ions used were Fe$^{2+}$, Co$^{2+}$, Ni$^{2+}$ and Cu$^{2+}$. The electrodes exhibited fast and wide linear response in the basic drug concentration of 10$^{-5}$ ∼10$^{-3}$ mol/l with a response slope of 50∼60 mV/decade in a buffer solution of pH 4∼8. The electrodes exhibited good selectivity for many basic compounds.mpounds.

• 대한전기학회논문지
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• 제45권2호
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• pp.193-198
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• 1996

Low power superconducting persistent current switch(PCS) for the superconducting magnet systems in the persistent mode was developed and its experimental results were analyzed when the system was charged or discharged. The multifilament NbTi wire with Cu matrix was used for the PCS. The constructed NbTi superconducting switch with superconducting magnet system operated successfully. It also operated on-off switching action with good stabilization. The maximum operating current in persistent mode was 60A (at 1T). In persistent current mode, the decay of the persistent current at 60A was observed. Its decay was 3.55% in 60 min. It is possible to make the persistent current switch with the better decaying of persistent current if some problems for joint resistance are solved.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.523-524
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• 2006

The $TiB_2$ dispersion strengthened copper alloy was attracted as thermal and electrical functional material for the high mechanical strength, high thermal stability and good conductivity of $TiB_2$. In the present study, the focus is on the synthesis of $TiB_2$ dispersed copper alloy by spark plasma sintering process using copper oxide and titanium diboride as raw materials. The mechanical, thermal and electrical properties of sintered bodies were discussed with the sintering parameters, and developed microstructure and phase of sintered bodies.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part 1
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• pp.495-496
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• 2006

The kneading process and formulations of feedstock obviously affect the quality of MIM products. In the present work, the rheological behaviour of the composite MIM feedstock, metal matrix (Cu) with few additions of ceramic powders $(Al_2O_3)$, was measured by a self-designed/manufactured simple capillary rheometer. Experimental results show that the distribution between powders and binder is more uniformly when blending time increased. Though high powder loading will increase the feedstock viscosity, the fluidity reveals relatively stable through the load curves of extrusion. Besides, the temperature-dependence of viscosity of the feedstock approximately follows an Arrehnius equation. Basing on Taguchi's method, the kneading optimization conditions and the rheological model of the feedstock were established, respectively.

• Bulletin of the Korean Chemical Society
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• 제6권1호
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• pp.7-11
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• 1985

The crystal structure of phlorizin, a ${\beta}$ -D-glucopyranoside of a flavonoid dihydrochalcone phloretin, has been determined by single crystal diffraction methods using diffractometer data obtained by the ${\omega}-2{\theta}$ scan technique with Cu $K{\alpha}$ radiation from a crystal with space group symmetry $P2_12_12_1$ and unit cell parameters a = 4.9094 (2), b = 19.109 (1), c = 23.275 (4) $\AA$. The structure was solved by direct methods and refined by full-matrix least-squares to a final R = 0.047 for the 1697 observed reflections. The dihydrochalcone moiety is flat and fully extended. The glucose ring has the $^4C_1$ chair conformation and the conformation of the primary alcohol group is gauche-gauche. The crystal packing is dominated by an extensive hydrogen bonding pattern. There are one strong and two weak intramolecular hydrogen bonds in the phlorizin molecule.

• Bulletin of the Korean Chemical Society
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• 제6권4호
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• pp.222-224
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• 1985

The crystal structure of sulindac, $C_{20}H_{17}Fo_3S$, one of the nonsteroid antiinflammatory agents, has been determined by the X-ray diffraction techniques using diffractometer data obtained by the $\varpi-2{\theta}$ scan technique with Cu $$K_{\alpha}$$ radiation from a crystal with space group symmetry Pbca and unit cell parameters a = 8.166(1), b = 18.291(8), c = 23.245(10) ${\AA}.$ The structure was solved by direct methods and refined by full-matrix least-squares to a final R = 0.11 for the 1153 observed reflections. The carboxyl group is nearly perpendicular to the indenyl ring as observed in indomethacin. The dihedral angle between the indenyl and phenyl rings is $35^{\circ}while$ the corresponding angle in indomethacin is $67^{\circ}.$ Crystal packing consists of a hydrogen bond and partial ring stacking between the indenyl rings.