• Archives of Pharmacal Research
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• v.18 no.1
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• pp.22-26
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• 1995

The solubility and dissolution rate of naproxen (NPX) complexed with 2-hydroxypropyl-.betha.-cyc-lodextrin (2-HP.betha.CD) using coprecipitation, evaporation, freeze-drying and kneading method were investigated. Solubility of NPX linearly increased (correlation cefficient, 0.995) as $2-HP\betaCD$ concentraction increased, resutling in $A_l$ type phase solubility curve. Inclusion complexes prepared by four different methods were compared by different methods were compared by dfferential scanning calorimetry(DSC). The NPX showed sharp endothemic peak around $156^{\circ}C$ but inclusion complexes by evaporation, freeze-drying and kneading method showed very broad peak without distinct phase transtion temperature. In contrast, inclusion complex prepared by coprecipitation method resulted in detectable peak around $156^{\circ}C$ which is similar to NPX, suggesting incoplete formation of indusion co plex. Dissolution rate of inclusion complexes prepared by evaporation, frezz-drying and kneding except coprecipitation method was largely enhanced in the simultaed gastric and intestinal fluid when compared to NPX powder and commercial $NA-XEN^\registered$tablet. However, about 65% of NPX in gstric fluid. in case of inclusion complex prepared by coprecipitation method, formation of inclusion complex appeared to be incoplete, resulting in no marked enhancement of dissolution rate. From these findings, inclusion complexes of poorly water-soluble NPX with $2-HP\betaCD$ were useful to increase soubility and dissolution rate, resting in enhancement of bioavailability and minimization of gastrointestinal toxicity of drug upon oral administration of inclusion complex.

• Journal of Ocean Engineering and Technology
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• v.27 no.2
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• pp.19-26
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• 2013

Stress triaxiality is recognized as one of the most important factors for predicting the failure strain of ductile metals. This study dealt with the effect of the average stress triaxiality on the failure strain of a typical low-temperature high-strength marine structural steel, EH36. Tensile tests were carried out on flat specimens with different notches, from relatively smooth to very sharp levels. Numerical simulations of each specimen were performed by using ABAQUS. The failure initiation points in numerical simulations were identified from a comparison of the engineering stress vs. strain curves obtained from experiments with simulated ones. The failure strain curves for various dimensionless critical energy levels were established in the average stress triaxiality domain and compared with the identified failure strain points. It was observed that most of the failure initiation points were approximated with a 100% dimensionless critical energy curve. It was concluded that the failure strains were well expressed as a function of the average stress triaxiality.

• YAKHAK HOEJI
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• v.42 no.4
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• pp.395-402
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• 1998

Mori Cortex Radicis, the root bark of mulberry tree, has been used in the treatment of bronchial asthma and other lung diseases in traditional medicine. There was a recent repor t that the water soluble part with molecular weight of above 10,000 has anti-allergic activity. Therefore, we intended to isolate and purify the anti-allergic compound from hot water extract of the Mori Cortex Radicis. Crude extract of Mori Cortex Radicis was prepared by hot-water extraction, and anti-allergic compound was further purified by alcohol precipitation, successive ultrafiltration, anion exchange chromatography and gel filtration chromatography. This compound had homogeneity which was shown by the sharp single peak in HPLC chromatogram (TSK-GEL G400OPW column, RI detector). The molecular weight of the compound was estimated as 23Kda on the basis of calibration curve plotted against protein standards. This compound was identified as complex of sugar, protein and lignin (19.2: 5.9: 72.7), and proteolysis could not decrease the anti-allergic activity but mild delignification decreased the activity remarkably. Therefore, we concluded that the anti-allergic compound of Mori Cortex Radicis was a lignin-carbohydrate complex.

• Computers and Concrete
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• v.10 no.4
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• pp.331-347
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• 2012

This paper describes the varying material model, the analysis method and the software development for reinforced concrete circular columns confined by spiral or hoop transverse steel reinforcement and subjected to eccentric loading. The widely used Mander model of concentric loading is adapted here to eccentric loading by developing an auto-adjustable stress-strain curve based on the eccentricity of the axial load or the size of the compression zone to generate more accurate interaction diagrams. The prediction of the ultimate unconfined capacity is straight forward. On the other hand, the prediction of the actual ultimate capacity of confined concrete columns requires specialized nonlinear analysis. This nonlinear procedure is programmed using C-Sharp to build efficient software that can be used for design, analysis, extreme event evaluation and forensic engineering. The software is equipped with an elegant graphics interface that assimilates input data, detail drawings, capacity diagrams and demand point mapping in a single sheet. Options for preliminary design, section and reinforcement selection are seamlessly integrated as well. Improvements to KDOT Bridge Design Manual using this software with reference to AASHTO LRFD are made.

• Korean Journal of Food Science and Technology
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• v.17 no.5
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• pp.345-349
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• 1985

The textural properties of acorn flour gels were investigated with the variations in the concentraction, storage time and storage temperature by the use of Instron Universal Testing Machine. The experimental design was $3^3$ factorial experiment. TPA curves of acorn flour gels showed two sharp peaks in the first bite and no negative peak. The hardness and brittleness of acorn flour gels were very significantly affected by concentration, storage time and storage temperature. For the height difference between first peak and second peals, the main effects for concentration and storage temperature were very significant and the main effect for storage time was not negligible. For bend, the effect of concentration was more significant than the effect of storage temperature, and storage time effect was negligible. Springiness was affected only by the concentration.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.05a
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• pp.279-282
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• 2005

Composites comprising various volume fractions of crystalline nickel and bulk amorphous (BA) were produced by means of electroless coating of nickel on BA powder of $Cu_{54}Ni_6Zr_{22}Ti_{18}$ and subsequent spark plasma sintering (SPS) of coated BA powder. The flow curves of composites at various temperatures in the supercooled liquid region were determined by the uniaxial compression test with various strain rates. During compression at $450^{\circ}C$ with $\dot{\varepsilon}=2\times10^{-3}$, the monolithic BA sample and crystalline-BA composites displayed the superplastic deformation with $\varepsilon>1.4$. At temperatures above $460^{\circ}C$, the stress-strain curve of the monolithic BA sample depicted a sharp peak stress and a fellowing stress drop due to cracking, while those of the crystalline-BA composites displayed work-hardening up to the imposed strain. FEM analysis indicated that a fairly homogeneous strain state prevailed throughout the composite, while a higher level of stress was obtained in a harder BA.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.8
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• pp.113-119
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• 2000

There are two major factors which affect the cam design : the pressure angle and the radius of curvature, Cam shape will have an instantaneous radius of curvature at every point. Even though the design constraint of the pressure angle has been satisfied the follower may still not complete the desired contact motion. If the radius of the follower roller is larger than the concave(negative) radius on the cam it occurs the gap between the cam and the follower roller at the contact point. And also if the curvature of the pitch curve of the cam is too sharp the cam profile may be undercut. This paper proposes a new approach which uses the relative velocity of the follower roller parallel to the tangent line at the contact point on the cam surface for determining the pressure angle and the relative acceeration for determining the radius of curvature.

• Bulletin of the Korean Chemical Society
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• v.17 no.9
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• pp.820-826
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• 1996

The p2H dependence of the NMR chemical shifts of the proton signals of heme methyl groups and ionizable groups in the vicinity of the heme were investigated. The p2H titration of heme methyl signals in four macroscopic oxidation states by saturation tranfer method was performed in the range between p2H 5.2 and 9.0. While the p2H dependence of the heme methyl resonance in fully oxidized state was small, most resonances in the intermediate oxidation states showed certain shifts. Particularly, methyl resonances of heme 1 (sequential heme numbering) exhibited sharp p2H dependence in acidic range. β-CH2 of the propionate of hemes 1 and 4 were titrated in the range of p2H 4.5-9.0. Only the 6-propionate group of heme 1 was protonated in this p2H range and its titration curve was similar to those of methyl resonances of heme 1 in intermediate oxidation states. Analysis of the microscopic redox potentials showed that they change depending on p2H. The ionizable groups responsible for the p2H dependence of these potentials are 6-propionate of heme 1 in acidic range and His 67 in basic range.

• Journal of Magnetics
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• v.18 no.1
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• pp.39-42
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• 2013

We studied the structural and electrical properties of $SrRuO_3$ thin films grown on $SrTiO_3$ (110) substrate. High resolution X-ray diffraction measurement of the grown film showed 1) very sharp peaks for $SrRuO_3$ film with a very narrow rocking curve with FWHM = $0.045^{\circ}$ and 2) coherent growth behavior having the same in-plane lattice constants of the film as those of the substrate. The resisitivity data showed good metallic behavior; ${\rho}$ = 63(205) ${\mu}{\Omega}{\cdot}cm$ at 5 (300) K with a residual resistivity ratio of ~3. The observed kink at ${\rho}(T)$ showed that the ferromagnetic transition temperature was ~10 K higher than that of $SrRuO_3$ thin film grown on $SrTiO_3$ (001) substrate. The observed rather lower RRR value could be partially due to a very small amount of Ru vacancy generally observed in $SrRuO_3$ thin films grown by PLD method and is evident in the larger unit-cell volume compared to that of stoichiometric thin film.

• Journal of the Optical Society of Korea
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• v.17 no.1
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• pp.63-67
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• 2013

We perform an optical vestigial sideband (VSB) filtering using a pair of Fabry-Perot (FP) filters. The transmittance curve of each FP filter is made to have sharp skirts using an offset between input and output coupling fibers. Moreover, the accurate periodicity of FP filters in the optical frequency domain enables the simultaneous VSB filtering of a large number of optical channels. With this VSB filtering technique, we transmit 12.5-GHz spaced $64{\times}12.4-Gb/s$ wavelength-division-multiplexing channels over a single-mode fiber up to 150 km without any dispersion compensations. When the channel spacing is reduced to 10 GHz, we achieve the spectral efficiency of 1 bit/s/Hz in conventional optical intensity modulation systems up to 125 km.