• KSBB Journal
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• v.13 no.5
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• pp.502-510
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• 1998

Stabilization of antibody, which is specific to Salmonella typhimurium antigens, present in dry states on membranes was accomplished, and its shelf-life, i.e., duration for maintaining minimum 90% of the initial activity, under optimal conditions was determined. To prepare two major components of an immuno-strip, the antibody was not only immobilized on nitrocellulose membrane surfaces but also placed within the pores of glass fiber membrane after conjugating it with old colloids as signal generator. Among potential stabilizers of the immuno-components, a disaccharide, trehalose, showed a significant protection effect of immunoglobulin structure from thermal energy. Optimal concentrations of trehalose for the respective component were significantly different (8-fold higher for the antibody-gold conjugate than for the immobilized antibody), which probably resulted from distinct densities and configurations of antibody present on the membranes. An additional requirement for the gold conjugate was freeze-drying of this substance such that the conjugate can be readily resolubilized upon contact with aqueous medium. By using the components prepared under optimal conditions, immuno-strips were constructed and exposed to thermal energy. Signals with less than 10% decrease in the intensity were maintained for approximately 21 days at 60$^{\circ}C$. Compared to previous reports, this result represented a 2-year shelf-life at room temperature. it was, however, two times longer if determined from thermal acceleration tests based on the theory of inactivation rate of protein. Such discrepancy between the two estimates could be mainly attributed to errors in accurately controlling temperatures and also to changes in the physical properties of membranes due to a high thermal energy.

• The Journal of Engineering Research
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• v.3 no.1
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• pp.215-222
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• 1998

The effect of La and Si addition of the thermal stabilization of $\gamma-alumina$ powers have been studied. Reagent grade $La(NO_3)_3{\cdot}6H_2O$ and $Si(OC_2H_5)_4$ were used as starting materials. These additives were introduced by wet impregnation method. Both La and Si additives suppressed the sintering of alumina and were found to be good thermal stabilizers of $\gamma-alumina$. Especially, Si drastically suppressed the phase transition of alumina at high temperatures. The major mechanisms for the thermal stabilization of alumina were seemed to be new phase formation and retardation of surface diffusion by addition of La or Si into alumina matrix.

• Journal of Electrical Engineering and Technology
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• v.5 no.3
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• pp.503-510
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• 2010

This paper proposes the use of fuzzy applications to a 4-machine and 10-bus system to check stability in open conditions. Fuzzy controllers and the excitation of a synchronous generator are added. Power system stabilizers (PSSs) are added to the excitation system to enhance damping during low frequency oscillations. A fuzzy logic power system stabilizer (PSS) for stability enhancement of a multi-machine power system is also presented. To attain stability enhancement, speed deviation ($\Delta\omega$) and acceleration ($\Delta\varpi$) of the Kota Thermal synchronous generator rotor are taken as inputs to the fuzzy logic controller. These variables have significant effects on the damping of generator shaft mechanical oscillations. The stabilizing signals are computed using fuzzy membership functions that are dependent on these variables. The performance of the fuzzy logic PSS is compared with the open power system, after which the simulations are tested under different operating conditions and changes in reference voltage. The simulation results are quite encouraging and satisfactory. Similarly, the system is tested for the different defuzzification methods, and based on the results, the centroid method elicits the best possible system response.

• The Korean Journal of Food And Nutrition
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• v.22 no.1
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• pp.150-157
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• 2009

The purpose of this study was to analyze the anthocyanin contents of black soybean crude extracts derived using a countercurrent system and to compare the effects of stabilizers(${\beta}-cyclodextrin$, maltodextrin) and sugars(sucrose, maltose) on the color deterioration of the anthocyanin. When the extraction process was kept at 100$^{\circ}C$ for 120$\sim$180 min, only C3G (cyanidin-3-glucoside) was detected in the water extract. The C3G contents in the water extracts acquired at 8$^{\circ}C$, 60$^{\circ}C$, and 80$^{\circ}C$ were 2.38 ppm, 1.73 ppm, and 1.73 ppm, respectively. Sucrose and maltose retarded color deterioration of the crude pigment extract by the countercurrent method with methanol. Finally, the additions of maltodextrin or ${\beta}-cyclodextrin$ did not retard thermal color deterioration of the black soybean crude pigment extract.

• Polymer(Korea)
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• v.37 no.2
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• pp.156-161
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• 2013

Phenolic antioxidants are effective stabilizers that provide excellent long-term heat stability by preventing thermo-oxidative degradation during processing and service life. However, under a selected set of circumstances, certain types of phenolics have been susceptible to discoloration due to prolonged storage in an environment containing oxides of nitrogen. It is investigated that the effect of addition of secondary antioxidant and chemical structure of primary antioxidant on discoloration of amorphous poly-${\alpha}$-olefin (APAO), which is especially prone to be decomposed in high processing temperature. From the result, it is concluded that a higher level of steric hindrance of phenolic antioxidant provided by long alkyl chain allows a more enhanced synergic effect with secondary antioxidant.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.05a
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• pp.16.1-16.1
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• 2009

We have fabricated solution processed oxide semiconductor active layer for thin film transistors (TFTs). The oxide semiconductor layers were prepared by ink-jet printing the sol-gel precursor solution based on doped-ZnO. Inorganic ZnO-based thin films have drawn significant attention as an active channel layer for TFTs applications alternative to conventional Si-based materials and organic semiconducting materials, due to their wide energy band gap, optical transparency, high mobility, and better stability. However, in spite of such excellent device performances, the fabrication methods of ZnO related oxide active layer involve high cost vacuum processes such as sputtering and pulsed laser deposition. Herein we introduced the ink-jet printing technology to prepare the active layers of oxide semiconductor. Stable sol-gel precursor solutions were obtained by controlling the composition of precursor as well as solvents and stabilizers, and their influences on electrical performance of the transistors were demonstrated by measuring electrical parameters such as off-current, on-current, mobility, and threshold voltage. Microstructure and thermal behavior of the doped ZnO films were investigated by SEM, XRD, and TG/DTA. Furthermore, we studied the influence of the ink-jet printing conditions such as substrate temperature and surface treatment on the microstructure of the ink-jet printed active layers and electrical performance. The mobility value of the device with optimized condition was about 0.1-1.0 $cm^2/Vs$ and the on/off current ratio was about $10^6$. Our investigations demonstrate the feasibility of the ink-jet printed oxide TFTs toward successful application to cost-effective and mass-producible displays.