• The Korean Journal of Pesticide Science
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• v.9 no.4
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• pp.279-286
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• 2005

The herbicidal activities against pre-emergence barnyard grass (Echinochloa crus-galli) by a series of new 2-(4-(6-chloro-2-benzoxazolyloxy)phenoxy)-N-phenylpopionamide derivatives as substrate molecule were studied using molecular holographic (H) quantitative structure activity relationships (HQSAR) methodology. From the based on the findings, the higher herbicidal active compounds are predicted by the derived HQSAR model. The best HQSAR model (VI-1) was derived from fragment distinction combination of atoms/bonds in fragment size, $7{\sim}10$bin. The herbicidal activities from atomic contribution maps showed that the activity will be able to increased according to the R-substituents variation of the N-phenyl ring and change of 6-chloro-2-benzoxazolyloxy group. Based on the results, the statistical results of the best HQSAR model (VI-1) exhibited the best pedictability and fitness for the herbicidal activities based on the cross-validated value ($q^2=0.646$) and non cross-validated value ($r^2_{ncv.}=0.917$), respectively. From the graphical analyses of atomic contribution maps, it was revealed that the lowest herbicidal activitics depends upon the 4-(6-chloro-2-benzoxazolyloxy)phenoxy group ($pred.pI_{50}=-3.20$). Particularly, the R=4-fluoro, X=isobutoxy substituent (P2) of (X)-phenoxy-N-(R)-phenylpropionamide derivative is predicted as the highest active compound ($pred.pI_{50}=9.12$).

• Applied Chemistry for Engineering
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• v.27 no.4
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• pp.397-401
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• 2016

A new solid oxidizer, pyridinium dinitramide (Py-DN) is a low toxic energetic material which can be utilized as a HPGP (high performance green propellant). In this work, Py-DN was synthesized using various starting materials including potassium sulfamate, pyridine hydrochloride, strong nitric acid and sulfuric acid. Physical and chemical properties of the Py-DN were characterized using UV-Vis, FT-IR and a thermal analyzer and their properties were compared to those of previously prepared salts including ammonium dinitramide[ADN, $NH_4N(NO_2)_2$] and guanidine dinitramide[GDN, $NH_2C(NH_2)NH_2N(NO_2)_2$] in our lab. Endothermic and exothermic decomposition temperatures of Py-DN were $77.4^{\circ}C$ and $144.7^{\circ}C$, respectively. The combustion caloric value was 1739 J/g, which is thermally more sensitive than that of conventional dinitramides. It may enable to lower the decomposition temperature, which can reduce preheating temperature required for satellite thruster applications.

• Korean Chemical Engineering Research
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• v.49 no.2
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• pp.161-167
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• 2011

Recent popularity in mobile electronics requires higher standard on the mechanical strength of electronic packaging. Thus, the method of soldering between chip and substrate in electronic packaging process is changing from conventional method using intermetallic compound to a new method using organic solderability preservatives (OSP) in order to improve the stability and the reliability of final product. Since current OSPs have several serious problems like thermo-stability during packaging process, however, it is necessary to develop new OSPs having thermo-stability. The main purpose of this study is to develop various thermo-stable OSPs based upon poly(vinyl pyridine-co- methylmethacrylate) and to evaluate their anti-oxidation property protecting Cu pad, thermo-stability and solubility to acid- or alcohol-containing aqueous solution during pos-fluxing. All OSPs showed not only good anti-oxidation property, thermo-stability and solubility but also more advantages like low cost, less odor, and less hygroscopic.

• Journal of Animal Science and Technology
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• v.54 no.2
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• pp.95-101
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• 2012

The objective of this study was to examine the effect of amides as a cryoprotectant for semen cryopreservation in Korean Jeju Black Bull. The semen was cryopreserved with extenders containing 5% dimethyl acetamide (DMA), 5% dimethyl formamide (DMF), 5% methyl formamide (MF) or 7% glycerol. Post-thawed sperm were evaluated for sperm motility, viability, acrosome integrity and membrane integrity. Post-thawed sperm motility was significantly higher (p<0.05) in glycerol and DMF ($64.00%{\pm}9.62$ and $59.00%{\pm}5.48$, respectively) than DMA and MF ($50.00%{\pm}3.24$ and $44.00%{\pm}4.18$, respectively). Sperm viability wassignificantly higher (p<0.05) in glycerol and DMF ($58.25%{\pm}7.35$ and $53.05%{\pm}3.77$, respectively) than others. However, for sperm motility and viability, there were no differences among glycerol and DMF. Also, swelling sperm ratio by hypo-osmetic selling test (HOST) was significantly increased (p<0.05) in glycerol and DMF treatments ($45.12%{\pm}25.08$ and $44.95%{\pm}8.58$, respectively). The percentage of capacitated sperm assessed by CTC staining, F pattern was lower (p<0.05) in DMF than others. B pattern was increased (p<0.05) in DMA, DMF and MF when compared with glycerol. AR pattern ratio was decreased (p<0.05) in glycerol and DMF when compared with DMA and MF. These results suggested that amides performed better and could be used as a cryoprotectant for semen freezing of Korean Jeju Black Bull.