• Elastomers and Composites
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• v.52 no.4
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• pp.272-279
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• 2017

The heterocoagulation of latex is a simple and useful method to fabricate various polymer nanocomposites in which a precise control of the colloid stability is essential. In this work, a multi-layered graphenes (MLGs)/poly(styrene-co-butyl acrylate) (P(S-co-BA)) nanocomposite having an excellent dispersion of MLGs was prepared via the sudden heating heterocoagulation process. The P(S-co-BA) component was obtained by emulsion polymerization. This process can effectively shorten the process and particles growth steps. The colloid stability of these dispersions was controlled by factors such as ionic charge, temperature, and reaction times. The influence of these factors on heterocoagulation was evaluated and the properties of the nanocomposites were investigated. The conductivity of the MLGs/P(S-co-BA) nanocomposites increased from -11.53 to -5.70 S/cm for an increase in MLG content from 0.01 to 5 wt%. Moreover, percolation threshold was observed in the case of 0.01 wt% MLGs.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10a
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• pp.91-91
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• 2003

Major factors including solvent and reaction temperature in the cationic polymerization of isobutyl vinyl ether (IBVE), photoinduced in the presence of diphenyliodonium iodide (DPII) zinc iodide in toluene/diethyl ether mixed solvent has been investigated. It was found that the living nature of the propagating species and the tacticity of the resulting polymer is significantly dependent on these factors. The addition of diethyl ether (DEE) results in not only the loss of the cationic living nature but also decrease in the isotactic content.

• Ocean Systems Engineering
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• v.6 no.2
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• pp.191-201
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• 2016

Stern bearing is a key component of marine propulsion plant. Its environment is diverse, working condition changeable, and condition severe, so that stern bearing load is of strong time variability, which directly affects the safety and reliability of the system and the normal navigation of ships. In this paper, three affecting factors of the stern bearing load such as hull deformation, propeller hydrodynamic vertical force and bearing wear are calculated and characterized by random theory. The uncertainty mathematical model of stern bearing load is established to research the relationships between factors and uncertainty load of stern bearing. The validity of calculation mathematical model and results is verified by examples and experiment yet. Therefore, the research on the uncertainty load of stern bearing has important theoretical significance and engineering practical value.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.384.3-385
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• 2002

Head of Panax ginseng C. A. Meyer indicates its growth number of years and has been widely used for supplying energy to weaklings or used as vomit. Butanol fraction of Panax ginseng head was significantly effective on gastritis and ulcer models in rats. and also had anti-oxidative properties in the previous study. It has been well established that gastric ulcer is induced by imbalance between aggressive factors and protective factors. and the oxidative reaction makes the lesions on gastric mucosal injury severer. (omitted)

• Journal of Electrochemical Science and Technology
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• v.7 no.1
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• pp.1-12
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• 2016

The production of oxygen and hydrogen from solar water splitting has been considered to be an ultimate solution for energy and environmental issues, and over the past few years, nano-sized semiconducting metal oxides alone and with graphene have been shown to have great promise for use in photocatalytic water splitting. It is challenging to find ideal materials for photoelectrochemical water splitting, and these have limited commercial applicability due to critical factors, including their physico-chemical properties, the rate of charge-carrier recombination and limited light absorption. This review article discusses these main features, and recent research progress and major factors affect the performance of the water splitting reaction. The mechanism behind these interactions in transition metal oxides and graphene based nano-structured semiconductors upon illumination has been discussed in detail, and such characteristics are relevant to the design of materials with a superior photocatalytic response towards UV and visible light.

• Journal of Korean society of Dental Hygiene
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• v.16 no.2
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• pp.155-163
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• 2016

The purpose of the review article is to investigate the influence of periodontal diseases on preterm birth(PTB) and low birth weight(LBW). PTB and LBW are the main risk factors of infant mortality and a major public health problem. PTB is defined as delivery at less than 37 weeks and LBW is less than 2,500 grams. Over Approximately 60 percent of perinatal mortality results from PTB or LBW. Although the causes of PTB and LBW are not fully understood, infection is the leading cause of PTB and LBW. Periodontal diseases are serious disease burdens because they are caused by bacterial endotoxin, inflammatory reaction, and cytokine. The periodontal diseases are the predisposing factors of cerebrovascular and cardiovascular diseases including atherosclerosis. Over the past 15 years, previous studies revealed that periodontitis had adverse outcomes including PTB and LBW in pregnancy.

• Journal of the Korean Ceramic Society
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• v.33 no.2
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• pp.235-241
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• 1996

Self-Propagating high temperature synthesis(SHS) technique was used to synthesize the spinel phase of MgAl2O from MgO and Al powder. Processing factors such as mixing time preheating temperature and ignition catalyst were varied to determine the optimum condition to form MgAl2O4 phase. The reaction products were heat treated at the temperature range of 120$0^{\circ}C$ and 150$0^{\circ}C$. to observe phase transformation of unreacted materials. Processing factors such as 48 hrs-mixing 80$0^{\circ}C$-preheating and 20wt% KNO3-ignition catalyst were effective of the formation of MgAl2O spinel. An activation energy 49.7kcal/mol. was calculated to form a MaAl2O4 spinel from unreacted materials.

• Corrosion Science and Technology
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• v.11 no.6
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• pp.270-274
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• 2012

This study represents the result of corrosion monitoring on reinforced concrete specimens by means of multi-functional corrosion monitoring sensors. To confirm the effectiveness of the sensors, eight different kinds of condition were adopted. Test factors were corrosion potential, current, corrosion rate, resistivity, and temperature, which were monitored with the sensors. Through this study, judging corrosion of steel in concrete with single corrosion factor such as corrosion potential was difficult, because many other factors can have an influence on the reaction of corrosion. By using three different kinds of sensors, it could enhance the accuracy of corrosion monitoring.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.793-808
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• 2009

This paper presents procedure and prediction method of internal and external stabilities when designing D.C.M, with main factors to be considered, such as chemical reaction of additive, physical properties of stabilized body and mixing strength. Results show that through case studies, a design unconfined compressive strength of stabilized body (hereafter referred to as 'compressive strength') directly depends on the quantity of cement, which is decided by laboratory test, and the compressive strength enormously affects internal and external stabilities. So laboratory mixing test to obtain the compressive strength for design allowable stress should be given careful considerations.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.11a
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• pp.9-12
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• 2000

Insulators for high-voltage and large-power should be endured mechanically the weight of mold bushing itself and the force of pushed from contact with circuit breaker and conductor. But dielectric breakdown could be occurred result from the external circumstances and internal factors such as chemical reaction, partial discharge, change of temperature and the relation of temperature-time in process of casting. Therefore, to get rid of external and internal factors of dielectric breakdown. Furthermore, to prevent the internal cracks, void, cavity which resulted from the contraction originated on the interface between copper and epoxy resin, formed semi-conductive layer with partially carbon painted on copper bar. The PD properties and the insulation qualities of epoxy molded insulators were improved by roles of cushions for the direction of diameter and natural sliding effects as like separated from conductor for the direction of length.