• Applied Chemistry for Engineering
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• v.21 no.6
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• pp.689-693
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• 2010

When natural rubber dissolved in toluene comes into use as a binder of carbon powder, the volatilization of solvent just after the construction of biosensor brought the mechanical robustness on the paste. This characteristic satisfied the pre-requisite condition for the practical use of carbon paste electrode and a biosensor for the determination of hydrogen peroxide was designed. In order to evaluate its electrochemical qualitative and quantitative behaviors, various electrochemical kinetic parameters of the electrode, e.g. the symmetry factor (${\alpha}$, 0.37), the exchange current density ($i_0$, $0.075mAcm^{-2}$), the capacitance of double layer ($C_d$, $9.7{\times}10^{-3}F$), the time constant (${\tau}_A$, 0.92 s), the maximum current ($i_{max}$, $5.92{\times}10^{-7}Acm^{-2}$), the Michaelis constant ($K_M$, $1.99{\times}10^{-3}M$) and others were investigated. Results show that natural rubber is a promising binder of carbon powder.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.1
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• pp.366-375
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• 1991

In this study, vibrational behavior of uniform pipe carrying a moving medium is studied by using a transfer matrix and the displacement function derived from the conventional beam theory. In various boundary conditions, flow velocity and mechanical property change of the variation of natural frequency are investigated. The Coriolis term in the original differential equation of motion has been ignored in the investigation. This method is used to study the variation of natural frequency with flow velocity for clamped-clamped, cantilevered, clamped-pinned, pinned-pinned, free-free straight pipe element. It is shown that clamped-clamped, free-free pipe have the highest natural frequency and critical velocity values while cantilevered pipe have the smallest natural frequency for the same mechanical properties. From the vibration effects of mechanical property variation, it is shown that bending stiffness and pipe length variation has large influence on natural frequency and critical velocity. Since the order of transfer matrix is not changed with boundary conditions of pipe element, this method proposed can be easily applied to personal-computer for vibration analysis of pipe element. Furthermore, this method can be extended to three-dimensional system by using a coordinate transformation for the analysis of piping systems.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.12
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• pp.1680-1685
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• 2015

Since ancient days, domestic horses have been closely associated with human civilization. Today, horse racing is an important industry. Various genes involved in energy production and muscle contraction are differentially regulated during a race. Among them, creatine kinase (CK) is well known for its regulation of energy preservation in animal cells. CK is an iso-enzyme, encoded by different genes and expressed in skeletal muscle, heart, brain and leucocytes. We confirmed that the expression of CK-M significantly increased in the blood after a 30 minute exercise period, while no considerable change was observed in skeletal muscle. Analysis of various tissues showed an ubiquitous expression of the CK-M gene in the horse; CK-M mRNA expression was predominant in the skeletal muscle and the cardiac muscle compared to other tissues. An evolutionary study by synonymous and non-synonymous single nucleotide polymorphism ratio of CK-M gene revealed a positive selection that was conserved in the horse. More studies are warranted in order to develop the expression of CK-M gene as a biomarker in blood of thoroughbred horses.

• Journal of the Korean Institute of Gas
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• v.5 no.2 s.14
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• pp.43-51
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• 2001

ln this study, a natural gas pipeline network model was established using STONER. First a map of natural gas pipeline network was drawn on STONER and then the length and diameter of the pipe were inputted. And as the specific gravity of gas flowing in the pipeline which is the value of natural gas was inputted. Finally in order to decide the pipeline variables and gas temperature, through the verification with observed real data, the possible error was minimized. For the verification, the pipeline variables and gas temperature were assumed and the pipeline network analysis was accomplished with real demand data. The square deviation of analysed pressure from observed pressure was calculated and the minimum case was selected for the optimum pipeline variables and gas temperature. Thus a proper natural gas pipeline network model for real network was established.

• Journal of Plant Biotechnology
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• v.3 no.3
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• pp.145-149
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• 2001

This study was conducted to analyze the morphological characteristics such as flower color, flower type, flower diameter and flower stalk, and the main annual production yield, and genetic similarity of twenty four Gerbera species growing in Korea. Most of flower colors were pink. The numerical order of flower color was pink, orange, red, double-colored, and milk-white. Majority of flower types were sin81e or semidouble flowers. A few species were double flowers. flower diameters were from 7 ㎝ to 12 ㎝, showed significant differences compared to other characteristics. Flower stalks were ranged from 55 ㎝ to 65 ㎝. Only one species was the shortest as 55 ㎝. The others were similar size as about 65 ㎝. Main annual production yields were between 190 and 400 blossoms. Fifty seven reproducible polymorphic bands from eighty primers were used for analyses of genetic similarity. The genetic similarity of 24 collected Gerberas was largely classified into five groups. The average similarity coefficient was 0.72 ranged from 0.50 to 0.90. The highest similarity coefficient was shown between 'Sardana' with red/white flower color and double flower type, and 'Tamara' with orange flower color and double flower type as 0.90.

• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.2
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• pp.85-92
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• 2000

The purpose of this study was to identify the controlling factors to construct tidal flat ecosystems having similar characteristics as natural ones. We transplanted the soil in a constructed tidal flat to a natural one and vice versa. Parameters monitored after these transplantations were silt content, organic matter, bacterial population and oxidation-reduction potential. Moreover, the relationship among silt content, organic matter and bacterial population was investigated by laboratory column experiment. The silt content, organic matter, bacterial population and vortical profile of oxidation-reduction potential in the soil transplanted from the constructed tidal flat to the natural one changed to similar values to those In the natural one. On the contrary, all the parameters for the soil transplanted from the natural tidal flat to the constructed one changed to similar values as those in the constructed one. The silt contents in these two transplanted soils were in proportion to the organic carbon contents and bacterial population. Similarly, the bacterial population in laboratory column experiment increased with the increase in silt and organic matter contents. It seemed to be important to select a place to enhance accumulative of silt and/or to maintain the silt content by hydrodynamic control of seawater in order to construct a tidal flat having similar characteristics as natural one.

• Applied Biological Chemistry
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• v.43 no.4
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• pp.253-259
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• 2000

In order to study the effects of the maturing temperature of kanjang(Korean traditional soy sauce) mash on the distributions of chemical compositions and sensory characteristics of kanjang, test kanjang mash prepared by mixing one part of meju and three parts of 20% salt solutions was matured at 15, 30 and $45^{\circ}C$ for 60 days respectively. It was found that although the higher the maturing temperature upto $45^{\circ}C$ for 60 days of maturing the higher total nitrogen, total free amino acids and pigment content in kanjang could be obtained, better quality kanjang containing the lower acetic acid, butyric acid and pyroglutamic acid with the higher ratio of the glutamic acid to the total free amino acids and the higher sensory evaluation scores could be prepared by maturing kanjang mash at $15^{\circ}C$.

• Journal of Korean Society for Atmospheric Environment
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• v.29 no.2
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• pp.125-134
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• 2013

Various antimicrobial technologies have been developed to inactivate bioaerosols in indoor environments. In this study, air filter media were treated with a natural antibacterial agent of Sophora flavescens in order to inactivate the bacteria collected on the air filter. Three treatment methods were applied to manufacture the test antibacterial air filter media: electrospray, nebulization and dip-coating methods. In case of electrospray and nebulization processes, the size distribution of aerosolized natural antibacterial agent was measured using a scanning mobility particle sizer. Staphylococcus epidermidis bacteria were aerosolized to test inactivation of the filter media treated with a natural antibacterial agent. The pressure drop and the antibacterial efficiency of the filter media increased with increasing the mass loading of natural antibacterial agent in each treatment method. The antibacterial efficiency per loaded antibacterial agent mass by the electrospray method was the highest and the filter treated by the dip-coating method was the lowest among three treatment methods.

• Journal of the Earthquake Engineering Society of Korea
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• v.22 no.2
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• pp.55-62
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• 2018

In this study, natural period formular is presented for a RC shear wall structure with H-, T-, and L-shaped wall sections. The natural period formular proposed by Goel and Chopra and adopted in ASCE 7-10 was modified by using the ratio of the flange and web wall area. The natural periods of structures with H-shaped wall were numerically obtained, the results indicated that the ASCE 7-10 could not consider the natural period variation according to the length of the flange wall, but the proposed formula could do. Especially, ASCE 7-10 estimated much longer periods than eigenvalue analysis, and this implies that conservative seismic design is difficult. The periods by eigenvalue analysis exist between the upper and lower bounds given by the proposed formula, and conservative design is possible by using the proposed lower bound value. In order to verity the effectiveness of the proposed method, actual residential buildings with various types of flange walls are considered. Ambient vibration tests, eigenvalue analyses, and nonlinear dynamic analyses were conducted and the periods were compared with the values by ASCE 7-10 and the proposed formula. The results showed that the proposed formula could estimate more accurately the periods than ASCE 7-10.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.495-499
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• 2000

The relative affinity of seaweed alginate, polyguluronate and polymannuronate for cations was investigated. The cations used in this study were $Ca^{2+}$, $Cd^{2+}$, $Co^{2+}$, $Cu^{2+}$, $Fe^{3+}$, $Hg^{2+}$, $Mg^{2+}$, $Mn^{2+}$, $Pb^{2+}$, $Rb^{1+}$, $Sr^{2+}$ and $Zn^{2+}$. The ability of cations to precipitated polymers was determined as the relative affinity of seaweed alginate, polyguluronate and polymannuronate for cations. The relative affinity of polymers for cations in order are as follow: Seaweed alginate: $Fe^{3+}$,$Cu^{2+}$,$Cd^{2+}>Pb^{2+}>Co^{2+}$,$Zn^{2+}>Ca^{2+}>Sr^{2+}$,$Rb^{1+}>Mn^{2+}>Mg^{2+}$,$Hg^{2+}$ Ployguluronate:$Fe^{3+}$,$Cu^{2+}$,$Cd^{2+}>Ca^{2+}$,$Co^{2+}$,$Pb^{2+}>Sr^{2+}$,$Rb^{1+}$,$Zn^{2+}>Hg^{2+}$,$Mn^{2+}>Mg^{2+}$ Polymannuronate:$Fe^{3+}$,$Cd^{2+}$,$Cu^{2+}>Ca^{2+}$,$Pb^{2+}>Zn^{2+}$,$Rb^{1+}$$Sr^{2+}$,$Hg^{2+}>Co^{2+}>Mn^{2+}>Mg^{2+}$