• Asian-Australasian Journal of Animal Sciences
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• v.13 no.7
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• pp.995-1002
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• 2000

To evaluate energy efficiency and partition of nutrients, 32 piglets were weaned at 14 d of age and individually fed diets containing 15% fat from coconut oil (CO, medium chain saturated), high oleate sunflower oil (HOSO, n-9 series), soybean oil (SO, n-6 series), or linseed oil plus fish oil, (LF, n-3 series). After 4 weeks, the subjects were sacrificed to evaluate empty body composition and apparent ileal digestibility with the slaughter method. No statistical effect of dietary fat sources on growth was observed. The digestibility of fat from the coconut oil diet was higher than fats from the diets containing high levels of unsaturated fatty acids. The efficiency of use of metabolizable energy for growth averaged 63% and was not affected by the diet. Dietary fat composition was reflected strongly in backfat. Total body neutral and polar fatty acids were influenced too. For the whole body phospholipid fraction the ratio of n-6 to n-3 and the double bond index were 4.3, 5.8, 7.2, 0.78 and 69, 87, 89, 87 for CO, HOSO, SO, and LF respectively. These results show that for the coconut oil diet the degree of unsaturation of phospholipids in the body was lower and that, in the other diets, it did not differ, but double bond index was maintained with different n-6 to n-3 ratios in carcass fat. On the whole the data on body fat composition indicate that the dietary fat tended to be deposited in similar quantity in the body, whatever was the dietary fatty acid profile.

• Journal of Applied Reliability
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• v.15 no.3
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• pp.197-206
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• 2015

Failure analysis of pre-insulated pipe (SPPS 380, 400A) transporting high temperature water ($95{\sim}110^{\circ}C$) for a plant was carried out. The damaged area (${\Phi}5mm$) of pre-insulated pipe was found only on welds. The chemical composition of damaged pipe meets specification of carbon steel pipes for pressure service (KS D 3562). As results of microstructure analysis, crack propagated from outer to inside after pitting corrosion occurred on the outside surface. The non-metallic inclusion existed on the end of crack. And the non-metallic inclusion continuously and linearly formed along with the bond line of welds. Based on SEM-EDS analysis, the nonmetallic inclusions have higher Manganese (Mn) and Oxygen (O) content but sulfur (S) was not detected. As results of water quality analysis, hydrogen ion concentration and minerals like Fe, Mg, Si were in low level. But the content of dissolved oxygen (11.2 ppm) was slightly higher than that of standard. It seems that the cause of damaged pipe is grooving corrosion due to MnO inclusion formed on bond line and corrosion took place nearby welds.

• Elastomers and Composites
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• v.51 no.1
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• pp.1-9
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• 2016

Characterization of the UV oxidation for raw natural rubber (NR) was investigated in controlled conditions through image and FT-IR analysis. The UV oxidation was performed on a thin film of natural rubber coated on a KBr window at 254 nm and room temperature to exclude the thermal oxidation. Before or after exposure to UV light, image of the NR thin film was observed at a right or tilted angle. FT-IR absorption spectra were measured in transmission mode with the UV irradiation time. The UV oxidation of NR was examined by the changes of absorption peaks at 3425, 1717, 1084, 1477, 1377, and $833cm^{-1}$ which were assigned to hydroxyl group (-OH), carbonyl group (-C=O), carbon-oxygen bond (-C-O), methylene group $(-CH_2-)$, methyl group $(-CH_3)$, and cis-methine group $(cis-CCH_3=CH-)$, respectively. During the initial exposure period, the results indicated that the appearance of carbonyl group was directly related to the reduction of cis-methine group containing carbon-carbon double bond (-C=C-). Most of aldehydes or ketones from carbon-carbon double bonds were formed very fast by chain scission. A lot of long wide cracks with one orientation at regular intervals which resulted in consecutive chain scission were observed by image analysis. During all exposure periods, on the other hand, it was considered that the continuous increment of hydroxyl and carbonyl group was closely related to the decrement of methylene and methyl group in the allylic position. Therefore, two possible mechanisms for the UV oxidation of NR were suggested.

• Journal of the Korean Chemical Society
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• v.40 no.7
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• pp.483-491
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• 1996

Dieis-Alder reaction between cyclopentadiene and 5-membered ring compounds which have exo-cyclic double bond has been studied using the PM3 method. Transition states do not show large geometrical change with the variation of dienophiles. Two isomers are possible due to the rotation of the exo-cyclic double bond of a dienophile. The reactivity for the formation of different products are explained using the FMO energy gap. The exo and endo selectivity of the reaction has been also studied from the correlation between the deformation energy and the activation barrier. Minimum energy reaction path is discussed using the Curtin-Hammett principle.

• Korean Journal of Crystallography
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• v.8 no.1
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• pp.1-5
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• 1997

The crystal structure of the title compound consists of discrete 4-N,N-dimethylamino-4'-N'-methyl-stilbazolium, $C_{16}H_{19}N_2$, and tosylate, $C_7H_7SO_3$, dimer. The 4-N,N-dimethylamino-4'-N'-methyl-stilbazolium molecule has a trans conformation at the central C=C double bond: the dihedral angle between the phenyl and the pyridyl rings is $5.7(2)^{\circ}$ and the whole molecule is planar within $0.138(8){\AA}$. Tosylate molecules display hydrogen-bonded dimers with the O-H...O distances of 2.855(9) and $2.899(8){\AA}$, respectively. The shortest intermolecular contact is the distance $3.10(1){\AA}$ between O(3) and C(16).

• Journal of the Korean Chemical Society
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• v.32 no.3
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• pp.260-266
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• 1988

The rate constants for the nucleophilic addition reactions of thioglycolic acid and cysteine to ${\beta},\;{\beta}$-dichlorostyrene derivatives(p-H, p-Cl, $p-CH_3,\;and\;p-OCH_3$) were photochemically determined at various pH and a rate equation which can be applied over a wide pH range was obtained. On the bases of rate equation, general base catalysis and substituent effect, the plausible addition reaction mechanism was proposed: Above pH 9.0, the reaction was initiated by the addition of sulfide anion, and in the range of pH 7.0 to 9.0, the neutral molecules and it's anions attacked to the double bond, competitively. However, below pH 7.0, only the neutral molecules of thioglycolic acid or cysteine added to the carbon-carbon double bond.

• Bulletin of the Korean Chemical Society
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• v.12 no.5
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• pp.554-559
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• 1991

The photophysical and photochemical properties of khellin were compared with those of 8-methoxypsoralen (8-MOP). Quantum yields of fluorescence and triplet formation decreases as solvent polarity increases, which is opposite to 8-MOP, and photocycloadditivity of khellin to olefins is much lower than that of 8-MOP. Electron ejection from khellin by laser flash was not observed, but observed from 8-MOP. As models of 4',5'-monoadducts of khellin or 8-MOP with thymine base, khellin<>dimethylfumarate 4',5'-monoadduct (KDF) was also compared with 8-MOP<>thymidine 4',5'-monoadduct (F-2) in those properties to give some insight on the second-step biadduct formation resulting in cross-links of DNA duplex. KDF and F-2 were very similar to khellin and 8-MOP in photophysical properties, respectively. However, KDF did not form adducts with various olefins, and thus it is thought that 2,3-double bond of chromone moiety in khellin is hardly reactive in contrast with 3,4-double bond of coumarin moiety in 8-MOP. These results indicate that khellin is fairly photostable compound, a poor type Ⅰ photodynamic sensitizer and producer of ${O_2}^{-}$ which is some cause of phototoxic erythemal reactions and undesirable side effects. Therefore khellin is safer to use than 8-MOP in photochemotherapy of some skin diseases. Although khellin is much less reactive than 8-MOP, khellin must be also a monofunctional drug. Since khellin is, however, as effective as 8-MOP in photochemotherapy of some skin diseases, it is suggested that khellin may be different from 8-MOP in the action mechanism.

• Journal of Korean Tunnelling and Underground Space Association
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• v.14 no.3
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• pp.247-260
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• 2012

In order to reduce the amount of steel reinforcements in TBM tunnel segments, the use of Steel Fiber Reinforced Concrete(SFRC) is being tried. The steel fibers with higher aspect ratio than that used in tunnel shotcrete are preferred to compensate the deficiency in tensile strength of the segments. In this study, the tensile properties of SFRC with aspect ratio of steel fibers equal to 80 were evaluated through flexural test and Double Punch Test. In the results of flexural test, flexural strengths of the SFRC were increased about 30%~150% thanks to bond of steel fibers used to concrete and could be properly predicted by the equation proposed by Oh(2008). There was a great difference in the estimated direct tensile strengths of the SFRC by the equations presented in ACI and RILEM. It was found that the Double Punch Test could be suitable methodology to estimate the direct tensile strength presented in RILEM of the SFRC.

• The Journal of Engineering Research
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• v.3 no.1
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• pp.235-242
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• 1998

Hydrosilylation and vromination of vacterial poly($\beta$-Hydroxyalkanoates) containing carbon-carbon double bond or triple bond were carried out. The produced polymers were characterized by IR-spectroscopy and differential scnning calorimetry. Hydrosilylated polymers were characterized crystallinity while brominated polymers had lower degree of crystallinity with increased glass transition temperatures. Mixing polymers containing carbon-carbon triple bonds with Co(II) AND Pt(II) resulted crosslinked polymers.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.19 no.3
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• pp.292-300
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• 2006

In order to improve energy efficiency in the dilute trichloroethylene removal using the nonthermal plasma process, the barrier discharge treatment combined with manganese dioxide was experimentally studied. Reaction kinetics in this process was studied on the basis of final byproducts distribution. Decomposition efficiency was improved to about $99\;\%$ at the specific energy of 40 J/L with passing through manganese dioxide. C=C ${\pi}$ bond cleavage of TCE substances gave DCAC, which has the single bond of C-C through oxidation reaction during the barrier discharge plasma treatment. Those DCAC were broken easily in the subsequent catalytic reaction due to the weak bonding energy about $3{\sim}4\;eV$ compared with the double bonding energy in TCE molecules. Oxidation byproducts of DCAC and TCAA from TCE decomposition are generated from the barrier discharge plasma treatment and catalytic surface chemical reaction, respectively. Complete oxidation of TCE into COx is required to about 400 J/L, but $CO_2$ selectivity remains about $60\;\%$.