• Journal of Pharmaceutical Investigation
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• v.23 no.3
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• pp.145-153
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• 1993

Retaining a drug in the stomach by some means is sometimes necessary to extend the G1 absorption time of the drug more than 6-8 hrs. Hydrogel has often been examined for its feasibility as a dosage form, so called platform, that could be retained in the stomach due to its excellent swelling properties in the gastric fluid. In this study, polyvinylpyrrolidone (PVP) hydrogel crosslinked by albumin or acrylated albumin was synthesized in a tablet form and evaluated for its possibility as the platform. The synthesis of the hydrogel was performed by $^{60}Co\;{\gamma}-ray$ irradiation of N-vinyl-2-pyrrolidone (monomer) in the presence of a crosslinking agent: aqueous solution of albumin or acrylated albumin. Synthetic conditions such as radiation dose, dose rate and concentration of crosslinking agent were varied in order to optimize the swelling and mechanical properties of the hydrogels. Degree of swelling of albumin-crosslinked PVP (Al-PVP) was highly dependent on radiation dose, dose rate and albumin concentration: it was decreased as they increased. On the other hand, that of acrylated albumin-crosslinked PVP (Acryl-PVP) was almost independent on them except dose rate: it was decreased as the radiation dose rate increased. The compressive strength of the two hydrogels was decreased as the dose rate increased. Digestion of both PVP in artificial gastric fluid containing pepsin was delayed by the ${\gamma}-ray$ irradiation. In conclusion, Al-PVP and Acry-PVP with diverse swelling and mechanical properties could be obtained by controlling synthetic conditions, mainly the irradiation dose rate.

• KSBB Journal
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• v.32 no.2
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• pp.108-116
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• 2017

Omeprazole, a benzimidazole derivative, suppresses gastric acid secretion by inhibiting $H^+/K^+$ ATPase in gastric parietals cells, and by reducing $H^+$ concentration. To improve stability of esomeprazole magnesium dihydrate (ESMD), enteric-coated preperation was composed of core tablet, subcoating and enteric coating layer. We were evaluated in vitro dissolution characteristics between test and reference ESMD preparation and stability. We could prepare enteric-coated formulation of ESMD by controlling disintegrating agent and coating ratio which could rapidly dissolved in neutral or alkali medium. The formulation D5 with crospovidone of 1.25% and coating ratio of 16.25% had a similar dissolution behavior compare to reference preparation. Difference factor ($f_1$) and similarity factor ($f_2$) were 0~15 and 50~100 and there was no significant difference in bioequivalence between formulations. The content and dissolution rate of formulation D5 were $96.54{\pm}0.21$ and $78.56{\pm}0.87%$ without change of color in accelerated condition ($40^{\circ}C$, RH 75%, high density polyethylene (HDPE) container) for 6 months. This study concluded that our enteric coated preparation of ESMD could be an useful method to improve stability of unstable drug without direct contact with coating material.

• The Plant Pathology Journal
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• v.19 no.3
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• pp.129-132
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• 2003

Fusarium wilt of cucumber caused by Fusarium oxy-sporum f. sp. cucumerinum is a serious vascular disease worldwide. Biological control of Fusarium wilt in several crops has been accomplished by introducing non-pathogenic Fusarium sup. and other biocontrol agents in soil or in infection courts. In this study, quantitative models were used to determine the biocontrol efficacy of inundatively applied antagonist formulations and the length of their effectiveness in controlling Fusarium wilt of cucumber. Quantitative model of the form [Y=L (1${-exp}^{-kx}$)] best described the relationship between disease incidence (Y, %) and inoculum density (X) of isolates F51 and F55. Isolate F51 was selected as a more virulent isolate based on the extent of its effectiveness in causing the wilt disease. The degree of disease control (Xi/X) obtained with the density of the biocontrol agent (Z), was described by the model [Xi/X=A (1${-exp}^{-cz}$)]. The zeolite-based antagonist formulation amended with chitosan (ZAC) was better at lower rates of application and peaked at around 5 g/ kg of the potting medium, whereas the peat-based antagonist formulation (PA) peaked at around 10 g/kg of the potting medium. ZAC formulation provided significantly better suppression of Fusarium wilt as described by the curvilinear relationship of the type Y= a+bX+c$X^2$, where Y represents percent disease incidence and X represents sustaining effect of the biocontrol agent.

• Proceedings of the Materials Research Society of Korea Conference
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• 2010.05a
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• pp.19.2-19.2
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• 2010

Printed electronics using printing process has broadened in all respects such as electrics (lighting, batteries, solar cells etc) as well as electronics (OLED, LCD, E-paper, transistor etc). Copper is considered to be a promising alternative to silver for printed electronics, due to very high conductivity at a low price. However, Copper is easily oxidized, and its oxide is non-conductive. This is the highest hurdle for making copper inks, since the heat and humidity that occurs during ink making and printing simply accelerates the oxidation process. A variety of chemical treatments including organic capping agents and metallic coating have been used to slow this oxidation. We have established synthetic conditions of copper nanoparticles (CuNPs) which are resistant to oxidation and average diameter of 20 to 50nm. Specific resistivity should be less than $4\;{\mu}{\Omega}{\cdot}cm$ when sintered at lower temperature than $250^{\circ}C$ to be able to apply to conductive patterns of FPCBs using ink-jet printing. Through this study, the parameters to control average diameter of CuNPs were found to be the introduction of additive agent, the feeding rate of reducing agent, and reaction temperature. The CuNPs with various average diameters (58, 40, 26, 20nm) could be synthesized by controlling these parameters. The dispersed solution of CuNPs with an average size of 20 nm was made with nonpolar solvent containing 3 wt% of binder, and then coated onto glass substrate. After sintering the coated substrates at $250^{\circ}C$ for 30 minutes in nitrogen atmosphere, metallic copper film resulted in a specific resistivity of $4.2\;{\mu}{\Omega}{\cdot}cm$.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.47 no.5
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• pp.5-14
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• 2015

Recently, the use of wood resources has been limited due to global environmental change, like global warming and desertification. It is very critical in Korea's paper industries because lots of virgin pulp are dependant on direct import from abroad for printing grade of paper. In this work, the alternatively best available technique for reducing the import amounts of BKP (bleached Kraft pulp) was considered by mixing DIP (deinked pulp) and TMP (thermomechanical pulp) for the manufacture of high quality paper. Generally known, the sheet prepared from fibrous raw materials of DIP and TMP has lower strength and optical properties than that prepared from BKP. This study was aimed to improve the sheet quality by using DIP and TMP. 4 kinds of polyelectrolytes were approached to find out the best effects on physical strength and optical brightness improvements, and high retention behaviors with GCC (ground calcium carbonate). In conclusion, amphoteric PAM with 1,000,000 molecular weight (g/mol) and 0.5 charge density (meq/g) was best for the improvement of strength properties with the mixture of DIP and TMP. GCC retention rate was also the highest with cationic-PAM of above 2,000,000 molecular weight (g/mol) and about 2.0-3.0 charge density (meq/g) of strengthening agent.

• Journal of Wetlands Research
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• v.7 no.3
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• pp.67-73
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• 2005

At research, the river's water which the sewage treatment facility will ask growth suppression the algae in the artificial rivers which it is using or it researched the method for the removal of the algae which grew. At results, when 60ppm of Chlorine was put in, the possibility of getting the result where 90% chlorophyll-a was removed and LC50 was 0.8ppm. The algae did not create even after 20days by which uses prevent agent of creation of the algae. Controlling the chlorine almost there was not an extinction effect of the algae which was already in large quantities multiplied, with in the effect against an water ecosystem widely known it is not. The prevent agent could inhibit creation of the algae, but it was judged with the fact that the methods are directly applied to the field must be researched continuously.

• The KIPS Transactions:PartA
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• v.16A no.5
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• pp.369-380
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• 2009

SNMP (Simple Network Management Protocol) is a standard protocol for management of network devices, and it provides excellent features such as scalability, information management, authentication, encryption, and access control. However, SNMP has a structural weakness to fully support control functions for integrated management of digital convergence devices, and it has a limitation of message length in SNMP communication. In this paper, we present an extended SNMP scheme for integrated management of digital convergence devices with control functions. We modified the SNMP architecture by adding DDS (Device Driver Subsystem) to SNMP engine for controlling different devices and by defining CADM (Control Agent Driver Model), therefore we solved the ambiguity problem between 'set' and 'control' of SNMP. And the extended SNMP made it easy for SNMP applications to use various control functions. The extended SNMP can transport massive high-level information by adding three new SNMP commands which eliminate the limit of message length.

• Journal of the Korean Society for Heat Treatment
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• v.35 no.3
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• pp.130-138
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• 2022

In this study, the characteristic of an amorphous fishing weight material according to controlling the alloy type and alloy composition of the glass forming agent added in PbO₂ oxide was investigated. According to the experimental, when the glass forming agent of 15wt%SiO₂-1wt%MgO content was added in β-PbO₂, an amorphous fishing weight substitute having the lowest friction coefficient, excellent corrosion resistance and durability was obtained. The cell number of PbO₂-15wt%SiO₂-1wt%MgO sample incubated in cell culture fluid tended to hardly decrease even after a lapse of 24 hours, It means that the fabricated PbO₂-15wt%SiO₂-1wt%MgO sample is significantly less-toxic and harmless to the human body, unlikely to metallic lead. It is considered that an fabricated amorphous fishing weight substitute proved to have a potential as an eco-friendly material with little marine pollution.

• The Korean Journal of Pesticide Science
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• v.3 no.3
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• pp.37-44
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• 1999

Two sulphamide (dichlofluanid and tolylfluanid) and three dicarboximide fungicides (iprodione, vinclozolin, procymidone) were used to investigate the correlation between in vitro antifungal activities and in vivo disease controlling activities against Botrytis cinerea, a causal agent of tomato gray mold and to develop efficient in vitro assays. They controlled effectively the development of tomato gray mold disease in vivo and their controlling activities were similar one another. However, several in vitro assays revealed that their in vitro antifungal activities were quite different between sulphamide and dicarboximide fungicides; the formers showed stronger inhibition activities for spore germination than the latters, whereas the formers inhibited mycelial growth less severely than the latters. The results indicate that the fungicides having different modes of action can show different in vitro antifungal activities according to in vitro assays, even if they have similar in vivo disease controlling activities. On the other hand, two rapid and efficient in vitro assays named Microtiter plate methods I (MPM I) and II (MPM II) were developed for the evaluation of fungicides for inhibitory activities against spore germination and mycelial growth of B. cinerea, respectively. The antifungal activities of five fungicides of two chemical groups in MPM I and II were correlated with the inhibitory activities against spore germination and mycelial growth using solid media, respectively.

• Journal of the Korean Ceramic Society
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• v.46 no.1
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• pp.41-46
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• 2009

The rheological properties of highly concentrated Ag nano sol depending on particle size were studied. The Ag nano sol was prepared by reducing the Ag ion in aqueous solution. The size of Ag nano particle was controlled by two steps of nucleation and growth, and the thickness of adsorption layer was varied by molecular weight of polyelectrolytes. The polyelectrolytes acted as not only ionic complex agent in ionic state and but also dispersant after formation of Ag nano sol. The effective volume was controlled by combination of varying the molecular weight of polyelectrolytes and the size Ag nano sol. The particle size and the viscosity of nano sol were characterized by particle size analyzer, HR-TEM and cone & plate viscometer. It was found that the 10 nm and 40 nm-sized Ag nano sols were prepared by controlling the nucleation and growth steps, respectively. Finally, we could prepare highly concentrated Ag nano sol over 50 wt%.