• Nuclear Engineering and Technology
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• v.54 no.3
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• pp.984-990
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• 2022

Corrosion release behavior of Alloy 690 in high-temperature water was investigated under the conditions of injected Zn concentrations of 0 ppb, 10 ppb and 50 ppb. A protective oxide film composed of Zn(Fe_xCr_1-x)₂O₄ and Cr₂O₃ was formed with Zn injection, resulting in a better corrosion resistance. In comparison with the Zn-free condition, the corrosion release rate under the Zn-injection conditions was smaller. The corrosion release inhibiting factors were 1.7 and 1.9 under the conditions of 10 ppb and 50 ppb Zn-injection respectively. A foreseen application of the corrosion and corrosion release rates has been proposed and discussed.

• YAKHAK HOEJI
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• v.41 no.3
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• pp.305-311
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• 1997

Sustained release-microspheres and immediate release-pellets were prepared to develop a controlled release multiparticulate system containing both water soluble and insoluble dr ug. Pseudoephedrin.HCl (EPD) and terfenadine (TRF) were used as model drugs, respectively. Sustained release-EPD microspheres were prepared by solvent evaporation method using Eudragit RL or RS as a matrix combined with pH-insensitive film coating. Smaller EPD microspheres were obtained when smaller amount of Eudragit as a matrix material or larger amount of magnesium stearate as a dispersing agent was used. However the obtained microspheres did not show syfficient sustained release characteristics. About 97% of EPD was released after 1 hr irrespective of matrix material used. Subsequent coating of the microspheres with pH-insensitive polymer such as Eudragit RS or ethylcelulose (EC) resulted good sustained in 37.5, 73.3 and 92.0% release of encapsulated EPD in distilled water after 1, 3 abd 7 hr, respectively. It corresponds to mean dissolution time (MDT) of 2.3 hr, which is much larger than that of un-coated EPD microspheres (0.0048 hr). Immediate release TRF pellets were prepared by spherically agglomerated crystallization using Eudragit E as an inert matrix and methylene chloride as a liquid binder. Using Eudragit E alone as a matrix resulted in satisfactory physical properties of the pellets such as sphericity, surface texture and flowability, but led to slower release of TRF from pellets than un-modified TRF powder (MDT of 1.70 vs 1.43 hr in pH 1.2 dissolution medium). Introducing propylene glycol or sodium lauryl sulfate as an emulsifier brought about faster release of TRF from pellets (MDT of 1.14 and 0.95 hr, respectively). In conclusion, microencapsulation by solvent evaporation combined with film coating and spherically agglomerated crystallization were successfully utilized to prepare controlled release multiparticulate system composed of sustained release EPD-microspheres and immediate release TRF pellets.

• Journal of Korea Entertainment Industry Association
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• v.13 no.7
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• pp.1-13
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• 2019

This study tried to explore the contents of film critics' reviews reported in the press. Based on fifty nine Korean movies with over 100,000 audience in 2017, this study collected 1113 reviews from fifty five movies with the exception of four without reviews. This study focused on the correlation between film's overall quality and four evaluation items such as directing, acting, story, and the visual. Examining the difference in the report timing of the review, the length of the review, and the intensity of the opinion, this study also analyzed the relationship between the internal aspects of reviews and box office performance. According to the results, the valence of critics' reviews was generally positive. Looking at the difference of reporting time, this valence was higher in the week before release than in the release week of film. The evaluation items of reviews were highly covered both before movie release and in the opening week. These were significantly declined in the second week of release. In the relationship between the number of reviews by each movie and box office performance, a positive correlation was found.

• Polymer(Korea)
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• v.29 no.6
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• pp.593-598
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• 2005

This work studied the loading capabilities and release behaviors of poly(ethylene-alt-maleic anhydride) (PEMAh)/poly(4-vinyl pyridine) (P4VP) multilayer films formed by the layer-by-layer(LbL) sequential self-assembly method, using Rodamine 6G(R6G) as an indicator. Thickness of the multilayer, and loading and subsequent release behavior of R6G from the multilayer were studied using UV-visible spectroscopy. The amount of R6G loaded in multilayer film increased linearly with increasing film thickness. pH-Sensitive permeability was observed, where lower pH environments increased both release rate and release amount. By additional assembling of PEMAh/poly(ethyleneimine) (PEI) capping layers on top of (PEMAh/P4VP)n multilayers, the release of R6G was better controlled.

• Journal of information and communication convergence engineering
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• v.15 no.4
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• pp.217-226
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• 2017

Korea has the tenth largest film industry in the world; however, detailed analyses using the factors contributing to successful film commercialization have not been approached. Using big data, this paper analyzed both internal and external factors (including genre, release date, rating, and number of screenings) that contributed to the commercial success of Korea's top 10 ranking films in 2011-2015. The authors developed a WebCrawler to collect text data about each movie, implemented a Hadoop system for data storage, and classified the data using Map Reduce method. The results showed that the characteristic of "release date," followed closely by "rating" and "genre" were the most influential factors of success in the Korean film industry. The analysis in this study is considered groundwork for the development of software that can predict box-office performance.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.11a
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• pp.721-725
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• 1996

The microfabricated test structures were used in order to evaluate the stress characteristics in films. The test structures were fabricated using surface micromachining technique, including HF vapor phase etching as an effective release method. The fabricated structures were micro strain gauge, cantilever-type vernier gauge and bridge for stress measurement, and cantilever for stress gradient measurement. The strain was measures by observing the deformation of the structures occurred after release etching and the amount of deformation can be detected by micro vernier gauge, which has gauge resolution of 0.2${\mu}{\textrm}{m}$. The detection principles and the degree of precision for the measured strain were also discussed. The characteristics of residual stress in LPCVD polysilicon films were studied using these test structures. The stress gradient due to the stress variation through the film thickness was calculated by measuring the deflection at the cantilever free end.

• Archives of Pharmacal Research
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• v.28 no.3
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• pp.364-369
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• 2005

HPMC (Hydroxypropyl methylcellulose) was chemically modified, using maleic anhydrides, to obtain pH-sensitive HPMCAM (Hydroxypropyl methylcellulose acetate maleate) polymers for use as novel duodenum-specific coating agents. The pharmaceutical properties of HPMCAM, such as film forming, acid values, pH-sensitive values, water vapor permeability, tensile strength and Tg, were investigated, and found to show good film forming properties. The pH­sensitive values were 3.0 to 3.7. In vitro results demonstrate that HPMCAM could completely suppress drug release within 2h in a simulated gastric fluid (pH 1.2) and rapidly release the drug in a simulated pathological duodenal fluid (pH 3.4). These results indicate that HPMCAM might be a useful material for a duodenum-specific drug delivery system.

• YAKHAK HOEJI
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• v.33 no.6
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• pp.324-332
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• 1989

Drug release from sulfanilamide granules coated with a polyelectrlyte complex of sodium tripolyphosphate and chitosan was studied. The coating film thickness increased with increasing concentration of chitosan in the coating solution and the drug release rates of the coated granules were significantly reduced comparing with those of the uncoated granules. $T_{50%}$ of the uncoated granules was 6 minutes, but those of the granules coated with chitosan-sodium tripolyphosphate from 0.5, 0.7, and 0.9% (w/v) chitosan-HCl solution were 27, 135, and 180 minutes, respectively in distilled water. In dissolution medium at pH 6.8, $T_{50%}$ of the uncoated granules was 4 minutes, but those of the granules coated with chitosan-sodium tripolyphosphate from 0.5, 0.7, and 0.9(w/v)% chitosan-HCl solution, were 32, 135, and 160 minutes, respectively.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.2
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• pp.228-237
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• 2005

The main purpose of this study was to investigate the red water reducing effects of phosphate based inhibitor when it was applied to water distribution system. The effects of pH, alkalinity, calcium concentration in the reduction of the red water also studied. The most finished water in Korea showed relatively high corrosiveness and was required to introduce some types of corrosion reducing methods such as addition of alkalinity. The precipitation of $CaCO_3$ by addition of $Ca(OH)_2$ formed porous film on the surface of the carbon steel pipes and was displaced easily from the surface of the pipes; on the other hand, addition of zinc phosphate (ZOP) formed reliable film on the surface and reduced iron release and color. Although the main function of ZOP was to suppress the release of Pb and Cu, it also reduced iron concentration released from water distribution pipes.

• Biomaterials Research
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• v.22 no.4
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• pp.290-302
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• 2018

Background: The main purpose of drug delivery systems is to deliver the drugs at the appropriate concentration to the precise target site. Recently, the application of a thin film in the field of drug delivery has gained increasing interest because of its ability to safely load drugs and to release the drug in a controlled manner, which improves drug efficacy. Drug loading by the thin film can be done in various ways, depending on type of the drug, the area of exposure, and the purpose of drug delivery. Main text: This review summarizes the various methods used for preparing thin films with drugs via Layer-by-layer (LbL) assembly. Furthermore, additional functionalities of thin films using surface modification in drug delivery are briefly discussed. There are three types of methods for preparing a drug-carrying multilayered film using LbL assembly. First methods include approaches for direct loading of the drug into the pre-fabricated multilayer film. Second methods are preparing thin films using drugs as building blocks. Thirdly, the drugs are incorporated in the cargo so that the cargo itself can be used as the materials of the film. Conclusion: The appropriate designs of the drug-loaded film were produced in consideration of the release amounts and site of the desired drug. Furthermore, additional surface modification using the LbL technique enabled the preparation of effective drug delivery carriers with improved targeting effect. Therefore, the multilayer thin films fabricated by the LbL technique are a promising candidate for an ideal drug delivery system and the development possibilities of this technology are infinite.