• Journal of Pharmaceutical Investigation
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• v.28 no.2
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• pp.115-119
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• 1998

Five polymorphic modifications of Cephradin were prepared by recrystallization from organic solvents. The isolated crystal forms were characterized by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and X-ray crystallography powder diffractometry. Modificaition 1 was the most stable form and decomposed at $201.3^{\circ}C$. Modification 3 and 4 were metastable. The dissolution of modification 3 and 4 was faster than that of marketed form.

• Bulletin of the Korean Chemical Society
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• v.29 no.7
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• pp.1369-1373
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• 2008

A stable twist boat conformation of thiane S-oxide 1a in solid state and in solution was unambiguously determined by single crystal X-ray crystallography and solution NMR analyses. On the contrary, the thiane Sdioxide 2 which was obtained from the oxidation of corresponding thiane S-oxide 1a was confirmed to adopt a regular chair conformation.

• Korean Journal of Crystallography
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• v.1 no.1
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• pp.57-59
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• 1990

We point out an error in the Table 2.3.2 of International Tables of X-Ray Crystallograhy Vol. IV(1974). The equivalent reflections of the point group 422 should be hkl=hkl=hkl=hkl=hkl=khl=khl=khl.

• Journal of Pharmaceutical Investigation
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• v.30 no.3
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• pp.201-205
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• 2000

Three new polymorphic modifications were prepared by recrystallization under various conditions and characterized by DSC and X-ray crystallography. In pH 4.0 buffer at $37{\pm}0.5^{\circ}C$, the polymorphic modifications showed significant differences in the dissolution rate. The dissolution rate of Mod. 4, amorphous form, was faster than that of marketed cefaclor (Mod. 1). When all modifications were stored at 52% RH, 95% RH and in silica gel desiccator, any polymorphic transformation was not observed.

• Journal of Pharmaceutical Investigation
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• v.30 no.4
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• pp.289-293
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• 2000

Three polymorphic modifications and one amorphous form were prepared by recrystallization under various conditions and characterized by DSC and X-ray crystallography. At $37{\pm}0.5^{\circ}C$, the polymorphic modifications showed significant differences in the dissolution rate. The dissolution rate of Mod. 4, amorphous form, was faster than that of other polymorphic modifications. When all modifications were stored at 52% RH, 95% RH, and in silica gel desiccator, amorphous form was transformed at 95% humidity condition.

• Polymer Science and Technology
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• v.6 no.2
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• pp.178-184
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• 1995

• Polymer Science and Technology
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• v.6 no.3
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• pp.279-288
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• 1995

• Bulletin of the Korean Chemical Society
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• v.20 no.1
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• pp.53-58
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• 1999

We synthesize the spinel lithium manganese oxides of the LiCrxMn2-xO4 from x=0.00 to 0.70 at 750 ℃ in air and identifiy them with X-ray crystallography.

• Korean Journal of Crystallography
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• v.12 no.4
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• pp.233-238
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• 2001

X-ray microdiffraction which uses x-ray beam focused down to a micron size from synchrotron radiation sources allow precision measurements of local orientation and strain variations in polycrystalline materials. Using x-ray microdiffraction setup at Pohang Light Source, we investigated the tex-ture of Cu interconnects with various widths on Si wafer by collecting Laue images and focused to about 2×3㎛ ² in size. Our results show that 1㎛ wide Cu interconnect had grains in rather ran- dom orientation. On the other hand the 20㎛ wide interconnects showed a 〈111〉fiber texture near the center. The grains were 2∼5㎛ long at the 1㎛ wide interconnect and 6∼8㎛ in size at the 20㎛ wide interconnect.

• Bulletin of the Korean Chemical Society
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• v.31 no.5
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• pp.1326-1330
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• 2010

Evidences have proved the versatile role of sulfur atom in supramolecular chemistry. $^1$Presence of S atom in the molecule usually results in the specific structural properties of molecules. In the present study, $S{\cdots}arene$, $N{\cdots}arene$, $CH{\cdots}{\pi}$, $CH{\cdots}S$ and $CH{\cdots}N$ type of weak interactions stabilize the conformation and self assembly of symmetrical as well as dissymmetrical molecules.