• Structural Engineering and Mechanics
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• v.1 no.1
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• pp.1-16
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• 1993

The behavior of shear-wall dominant, low-rise, multistory reinforced concrete building structures is investigated. Because there are no beams or columns and the slab and wall thicknesses are approximately equal, available codes give little information relative to design for gravity and lateral loads. Items which effect the analysis of shear-wall dominant building structures, i.e., material nonlinearity including rotating crack capability, 3-D behavior, slab-wall interaction, floor flexibilities, stress concentrations around openings, the location and the amount of main discrete reinforcement are investigated. For this purpose 2 and 5 story building structures are modelled. To see the importance of 3-D modelling, the same structures are modelled by both 2-D and 3-D models. Loads are applied first the vertical then lateral loads which are static equivalent earthquake loads. The 3-D models of the structures are loaded in both in the longitudinal and transverse directions. A nonlinear isoparametric plate element with arbitrarily places edge nodes is adapted in order to consider the amount and location of the main reinforcement. Finally the importance of 3-D effects including the T-C coupling between walls are indicated.

• Bulletin of the Korean Chemical Society
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• v.7 no.4
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• pp.275-279
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• 1986

Concentration dependences of the isotropic Raman band width and the peak position for the ${\nu}_1$ (C-H stretching) mode of nitromethane in chloroform-d, pyridine-$d_5$, 1,3,5-trifluorobenzene, and hexafluorobenzene have been investigated. For all solutions, the experimental concentration dependences have been well described by the concentration fluctuation model of Knapp and Fischer when appropriate values for the effective numbers (N) of nearest neighbors were used. For the $CH_3NO_2/C_6F_6$ solution, an abnormally small value (2) of N indicates strong intermolecular interaction.

• Bulletin of the Korean Chemical Society
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• v.15 no.2
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• pp.126-132
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• 1994

RhCl [P($C_6H_5)_3]_3$ complexes have been incorporated in polysulfone (PS) as a dispersion medium using cosolvent (THF). The interactions between Rh(Ⅰ) complexes and polysulfone polymer molecules are examined by infrared spectroscopy and thermal analysis. The chemical reactivity of Rh in PS films has been investigated by reacting Rh sites with CO, $H_2,\;D_2,\;O_2\;NO,\;C_2H_2\;and\;C_2H_4$ in the temperature range $25-200^{\circ}C$. Various Rh-carbonyl, -hydride and -nitrosyl species formed in PS films are characterized by their infrared spectra. Rh complexes in PS film show interesting catalytic reactivities in the reactions such as hydrogenation of $C_2H_2\;and\;C_2H_4$, oxidation of CO, and reduction of NO by CO or $H_2$ gas under relatively mild conditions.

• Environmental Engineering Research
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• v.21 no.3
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• pp.311-317
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• 2016

A new type of biofilter packed with composite carriers was designed for tertiary denitrification of the secondary effluent with removal of both oxidized nitrogen and suspended solids (SS). At the empty bed residence time of 15 min and organic carbon to nitrate nitrogen ($C/NO_3-N$) ratios of 2, 1.5 and 1 g/g, the removal percentage of $NO_3-N$ was 67%, 58% and 36% in the ethanol biofilter, and was 61%, 43% and 26% in the acetate biofilter, respectively. The biofilters packed with composite carriers removed SS effectively, with the effluent turbidity in both biofilters of less than 3 NTU. During the operating cycle between the biofilter backwashings, the $NO_3-N$ removal percentage decreased initially after backwashing, and then gradually increased. Under $C/NO_3-N$ ratios of 2, 1.5 and 1 g/g, the $NO_3-N$ reduction rate was 1.75, 1.04 and $0.68g/m^2/d$ in the ethanol biofilter, and was 1.56, 1.07 and $0.76g/m^2/d$ in the acetate biofilter, respectively. In addition, during denitrification, the ratio of the consumed chemical oxygen demand to the removed $NO_3-N$ was 5.06-8.23 g/g in the ethanol biofilter, and was 4.26-8.6 g/g in the acetate biofilter.

• Proceedings of the Ginseng society Conference
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• 1990.06a
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• pp.149-154
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• 1990

Various rates of 2, 4-2 were sprayed on 2 and 3 year old ginseng plants as fouler spray to define the critical concentration. No apparent plant injury was noticeable for those ginseng plants when application concentration of 2, 4-D doubled the recommended dosage (70 mil 10a). Neither abnormal fouler change occurred nor any inhibition in leaf and stem growth was resulted for the plants treated with 2, 4-D concentrated two times of the recommended dosage. When the rates of 2, 4-D application were increased greater than this level, injury ratings increased linearly with the rates of 2, 4-D application and plant growth was inhibited. Ethylene gas was not produced from the ginseng plant treated with 2 times concentrated 2, 4-D, how- ever the ginseng plants produced 0.03 to 0.09 ppd ethylene gas when the rate of application were increased 3 and 4 times, respectively. On the other hand the soybean treated with the recommended amount of 2i-D produced ethylene gas of 10-20 times higher compared with ginseng plants and died. Photosynthesis ability of the ginseng leaf was significantly decreased by 2, 4.D fouler application but it was recovered 4 weeks after 2, 4-D fouler treatment. The herbicide 2, 4-D was appreciated to 2, 3 and 4 years old ginseng plants as fouler spray with the rates of 0.5, 1.0, 1.5 and 2.0 times of the recommended dosage to define the effects of 2, 4-D on the plant growth and root yield of the ginseng, There were no significant differences in the leaf and stem growth between untreated and 2, 4-D treated plant. Berry maturing of 3 and 4 year old ginseng was not influenced by 2, 4-D. The root weight of 4 years old ginseng plant was not reduced b). application of 2, 4-D concentrated 2 times of the recommended dosage. Application time of the herbicide 2, 4-D had no effects on the leaf or stem growth of 2, 3 and 4 year old year old ginseng plants. When the ginseng seedling was treated with 2, 4-D, detrimental phenomena as stem bending and deceleration of seedling leaf margin occurred, but stem bending was recovere d in a few day.

• The Journal of Korean Academy of Prosthodontics
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• v.38 no.1
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• pp.1-11
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• 2000

Relining and rebasing are essential for long-term success and oral health in removable prosthodontics. Major features of failures between metal base and relining resins are adhesive failure due to lack of chemical bonding. The purpose of this study was to find a better metal primer and metal surface treatment method that enhance the bonding strength with relining resin materials. The surfaces of ticonium alloys were treated with $25{\mu}m$ sandblasting (Group A), stone wheel(Group B), stone wheel and EZ oxisor(Group C), $75{\mu}m$ sandblasting(Group D) and EZ oxisor application after $75{\mu}m$ sandblasting(Group E). They were subdivided into no primer application (Group I), MR bond application(Group II) and Metafast bonding liner (Group III). Then specimens were completed though being bonded with relining resins. The specimens were stored in $38^{\circ}C$ water for 48 hours and tensile strength was measured using the universal testing machine. The results were as follows, 1. Primer application groups showed higher bond strength than no primer application group(p<0.05). 2. In comparison with primer application groups, MR bond group showed higher bond strength than Meta fast bonding liner application group(p<0.05). 3. In comparison with surface treatment methods, Bond strengths of group A and B were significantly different with group C, D, and E, and group C were significantly different with group D, and E in no primer application group()(0.05). In primer application groups, group A, B, C were significantly different with group D and E(p<0.05). According to results of this study, Metal primer application and metal surface roughening were considered to be advantageous for relining of metal base dentures.

• Journal of Welding and Joining
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• v.20 no.5
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• pp.78-86
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• 2002

A metallurgical model for the prediction of prior austenite grain size considering the dissolution kinetics of M$_3$C precipitates at the heat affected zone of SA508-cl.3 was proposed. The isothermal kinetics of grain growth and dissolution were respectively described by well-known equation, $dD/dT=M({\Delta}F_{eff})^M$ and Whelan's analytical model. The isothermal grain growth experiments were carried out for measure the kinetic parameters of grain growth. The precipitates of the base metal and the specimens exposed to thermal cycle were examined by TEM-carbon extraction replica method. The model was assessed by the comparison of BUE simulation experiments and showed good consistencies. However, there was no difference between the model considering and ignoring $M_3C$ precipitates. It seems considered that pinning force exerted by $M_3C$ Precipitates was lower than driving force for grain growth due to large size and small fraction of precipitates, and mobility of grain boundary was low in the lower temperature range.

• Microbiology and Biotechnology Letters
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• v.15 no.6
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• pp.369-374
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• 1987

A bacterium which grows on D-$\alpha$-Amino-$\varepsilon$-Caprolactam as sole carbon, energy and nitrogen source was isolated from the sludge of industrial areas in Taegu, and identified as Alcaligenes eutrophus. The optimum pH, temperature and concentration of D-$\alpha$-Amino-$\varepsilon$-Caprolactam for the growth were 6.0, 3$0^{\circ}C$ and 0.2% respectively. The bacteria could utilize glucose and fructose as a carbon source, and utilize ammonium chloride, ammonium nitrate, ammonium sulfate and sodium nitrate as a nitrogen source, and utilize L-Iysine and L-glutamate as a carbon and nitrogen source. It was found with thin layer chromatography and polarimeter that D-$\alpha$-Amino-$\varepsilon$-Caprolactam was converted to L-Iysine by the cell-free extracts of Alcaligenes eutrophus A52.

• Carbon letters
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• v.2 no.1
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• pp.27-36
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• 2001

The pack-cementation process is the method which is formed SiC coating layer to improve weak oxidation properties of CFRCs (carbon fiber-reinforced carbons). This method develops the anti-oxidation coating layer having no dimensional changes and good wetting properties. In this study to improve the oxidative resistance of the prepared 4D CFRCs, the surface of CFRCs is coated by SiC using pack cementation method. The mechanical properties of SiC-coated 4D CFRCs are measured by the 3-point bending test, and their ablation properties are investigated by the arc torch plasma test. From the results, it is found that both mechanical and ablation properties of SiC-coated 4D CFRCs are much better than bare CFRCs.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.7
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• pp.1036-1039
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• 2002

The effect of germination on phytase activity in wheat NEAU123, triticale5305 and rye2 was studied in the present study. Germination significantly increased phytase activity by 2.04 times for wheat NEAU123 (3 d), 1.82 times for triticale 5305 (1 d) and 2.45 times for rye2 (1 d), respectively. It was safe for phytase in fresh malts kilned for 2 h at $40^{\circ}C$. Phytase in cereal seeds had strong heat stability. There was no loss of phytase activity in cereal seeds heated at $70^{\circ}C$ for 1 h, a little loss (${\leq}$5.46%) at $80^{\circ}C$ or $90^{\circ}C$. Even heated at $100^{\circ}C$, the phytase activity in wheat NEAU123, triticale5305 and rye2 remained 89.47%, 86.44% and 104.64%, respectively.