• The Microorganisms and Industry
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• v.25 no.2
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• pp.7-10
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• 1999

• Journal of Microbiology and Biotechnology
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• v.16 no.2
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• pp.163-177
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• 2006

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2003.06a
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• pp.175-176
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• 2003

• Korean Journal of Construction Engineering and Management
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• v.16 no.5
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• pp.86-96
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• 2015

According to previous research, the reason why Design-Build(hereinafter "DB") outperforms Design-Bid-Build(hereinafter "DBB") in terms of cost is due to less change orders(hereinafter "COs"). However, if biddropping was low for DBB resulting into increasing COs, then it would be wrong to conclude that DB is superior due to less COs. Therefore, in order to confirm such misjudgment, the attempt to comprehensively analyze biddropping, COs and delivery method was made as previous methods had analyzed either the relationship between delivery method and COs, or biddropping and COs. This research uses path analysis, which simultaneously compares effect sizes on COs according to delivery method and biddropping based on the project type, and validated the mediator effect. The research proved that DB outperforms DBB due to less COs cannot be validated as biddropping caused a mediator effect by intervening between the delivery method and COs for specific project types. Therefore, the mechanism of delivery method acts on COs through biddropping was established. Also, the identity of biddropping was investigated in a different perspective from previous research. Based on this result, this research is expected to help determine a delivery method by considering the mediator effect of specific projects and evaluate performance.

• Journal of Microbiology and Biotechnology
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• v.9 no.3
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• pp.365-367
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• 1999

A fuel cell type biosensor for lactate was developed using a metal-reducing bacterium, Shewanella putrefaciens IR-1. Under the operational conditions, the bacterial cell suspension generated the current without an electrochemical mediator in the presence of lactate. The current was proportional to the lactate concentration up to 30 mM.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2004.06a
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• pp.75-79
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• 2004

• Journal of Electrochemical Science and Technology
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• v.11 no.3
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• pp.310-317
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• 2020

A development of disposable strip-type galactose sensor for point-of-care testing (POCT) was studied, which was constructed using screen-printed carbon electrodes. Galactose levels were determined by the redox reaction of galactose oxidase in the presence of potassium ferricyanide as an electron transfer mediator in a small sample volume (i.e., less than 1 µL). The optimal performance of biosensor was systematically designated by varying applied potential, operating pH, mediator concentration, and amount of enzyme on the electrode. The sensor system was identified as a highly active for the galactose measurement in terms of the sensitivity (slope = 4.76 ± 0.05 nA/µM) with high sensor-to-sensor reproducibility, the linearity (R² = 0.9915 in galactose concentration range from 0 to 400 µM), and response time (t_95% = <17 s). A lower applied potential (i.e., 0.25 V vs. Ag/AgCl) allowed to minimize interference from readily oxidizable metabolites such as ascorbic acid, acetaminophen, uric acid, and acetoacetic acid. The proposed galactose sensor represents a promising system with advantage for use in POCT.

• Journal of Digital Convergence
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• v.17 no.5
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• pp.207-215
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• 2019

This study was attained to examine the relationship between the videogame players' motivation and loyalty, and to investigate the mediator effect of flow. We conducted a survey based on former researches and verified outcomes through empirical analysis. The results proposed that intrinsic and extrinsic motivation have positive influence on game loyalty, and flow has the mediating effect of this relationship. Additionally, extrinsic motivation has less impact on game loyalty and flow than intrinsic motivation does. The inherent value of game players from this paper will promote the development of VR(virtual reality) games or serious games.

• Transactions of the Korean hydrogen and new energy society
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• v.19 no.6
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• pp.498-504
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• 2008

Metal-reducing bacterium, Geobacter sulfurreducens is available for mediator-less microbial fuel cell (MFC) because it has biological nanowires(pili) which transfer electrons to outside the cell. In this study, in the anode chamber of the MFC system using G. sulfurreducens, the concentrations of NaCl, sodium phosphate and sodium bicarbonate as electrolytes were mainly optimized for the generation of electricity from acetate. 0.4%(w/v) NaClO and 0.5M $H_2SO_4$ could be utilized for the sterilization of acrylic plates and proton exchange membrane (major construction materials of the MFC reactor), respectively. When NaCl concentration in anode phosphate buffer increased from 5 to 50 mM, power density increased from 6 to $20\;mW/m^2$. However, with increasing sodium phosphate buffer concentration from 5 to 50 mM, power density significantly decreased from 18 to $1\;mW/m^2$. Twenty-four mM sodium bicarbonate did not affect electricity generation as well as pH under 50 mM phosphate buffer condition. Optimized anode chamber of MFC using G. sulfurreducens generated relatively high power density ($20\;mW/m^2$) with the maximum coulombic efficiency (41.3%).

• Korean Journal of Environmental Agriculture
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• v.31 no.1
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• pp.24-29
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• 2012

BACKGROUND: In recent years, microbial fuel cells (MFCs) have emerged as a promising technology for recovering renewable energy from waste biomass, especially wastewater. In this study, the possibility of bioelectricity generation in two chambered mediator-less microbial fuel cells (MFCs) was successfully demonstrated using fermentable and non-fermentable substrates. METHODS AND RESULTS: Two different electron acceptors have been tested in the cathode chamber for the effects of reducing agent on the power generation in MFCs. The average voltages of $0.26{\pm}0.014$ V and $0.36{\pm}0.02$ V were achieved with acetate using oxygen and potassium ferricyanide as reducing agent, respectively. Similarly, with glucose the average voltages of $0.256{\pm}0.05$ V and $0.340{\pm}0.04$ V were obtained using oxygen and ferricyanide, respectively. Using potassium ferricyanide as the reducing agent, the power output increases by 39 and 43% with acetate and glucose, respectively, as compared to the dissolved oxygen. Slightly higher coulombic efficiency (CE%) was obtained in acetate as compared to MFCs operated with glucose. The maximum power densities of 124 mW/$m^2$ and 204 mW/$m^2$ were obtained using dissolved oxygen and $K_3Fe(CN)_6$, respectively. CONCLUSION(s): This study demonstrates that power generation from the MFCs can be influenced significantly by the different types of catholyte. Relatively higher CE was obtained with $K_3Fe(CN)_6$. Thus, application of $K_3Fe(CN)_6$ as the catholyte can be vital for scaling uppower generation from the MFCs forreal time applications.