• Bulletin of the Korean Chemical Society
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• v.15 no.11
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• pp.1013-1016
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• 1994

• Journal of the Society of Disaster Information
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• v.10 no.2
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• pp.294-303
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• 2014

The state has the constitutional duty to secure the safety of its citizens and provide protection against any physical dangers. The Republic of Korea has a high threat of nuclear, biological and or chemical(hereafter referred to as NBC) attack from the Democratic People's Republic of Korea. Thus, the state has a responsibility to form a legislation to provide the protection for its citizens and implement duty to guarantee the human rights. Under the current legislation, the 'United Defense Act', 'Framework Act on Civil Defense' that are applied under wartime conditions are insufficient in providing the protection of the citizens of the state in the occurrence of NBC attack. Therefore, it is necessary that the 'Act for the Protection of Citizens in the occurrence of NBC Attack' is legislated to provide a system that protects the nation's citizens under the wartime conditions mentioned above. This paper incorporates a theoretical analysis of the need for the constitutional responsibility of the state to provide protection for its citizens under wartime conditions, the necessity of a specific measure to protect citizens during NBC attack, the relationship between 'Act for the Protection of Citizens in the occurrence of Nuclear, Chemical and or Biological Attack' and current legislations that are applied under wartime conditions, and the particulars of the proposed act.

• Proceedings of the Korean Geotechical Society Conference
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• 2003.03a
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• pp.189-196
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• 2003

Soil-cement column is often used as a contaminant barrier. This study presents the results of experimental study performed to investigate the changes of properties of soil-cement column under the attack of acids. Sulfuric nitric, and ascetic acid were used as contaminants. Specimen were made of clayey and sandy soils with addition of cement and water Permeability of soil-cement decreased with time during permeability test. When significant amount of acid percolated the specimen, permeability increased and compressive strength decreased due to the dissolution and leaching of cement and its chemical reaction compounds. Sulfuric and nitric acid were more effective than ascetic acid in deteriorating soil-cement column. Amount of acid required to lower the pH of soil cement below 12 was calculated from the results of permeability tests. This leads to a conclusion that, under the conditions employed in this study, the chemical stability of soil-cement column could be maintained against acid attack for longer than generally accepted lifetime of contaminant barriers.

• Journal of the Korean Applied Science and Technology
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• v.4 no.1
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• pp.61-66
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• 1987

2,4,6-Triamino-5-nitrosopyrimidine was prepared using malononitrile and guanidine carbonate, and acetylated refluxing in acetic acid with acetic anhydride in order to activate the nitroso group for nucleophilic attack. Nucleophilic attack of phenylpyrimidium bromide on the nitroso group of 2,4,6-triacetamido-5-nitrosopyrimidine gave the intermediate, which lost pyrdidine to give the nitrone derivative. Addition of the methanethiol anion to nitrone gave 2,4-diacetamido-7-phenyl-6-methylthiopteridine which was hydrolyzed to give 2,4-diamino-7-phenyl-6-methylthiopteridine. Spectral data (IR, M.S, NMR) were provided to identify the reaction products during synthesis.

• Resources Recycling
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• v.17 no.5
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• pp.11-18
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• 2008

The purpose of this study was to evaluate the effects of blast-furnace slag on chemical attack and carbonation of latex-modified concrete (LMC) and ordinary portland cement concrete as slag contents. Main experimental variables were performed latex contents (0%, 15%) and slag contents (0%, 30%, 50%). The compressive strengths, chemical attacks resistance and carbonation depth were measured to analyze the characteristic of the developed LMC and BS-LMC(latex-modified concrete added blast-furnace slag) on hardened concrete. The test results showed that compressive strength of BS-LMC with blast-furnace slag content 30% was quite similar to it of OPC without slag content. The structural quality deterioration was concerned when blast slag content was up to 50%. However, carbonation restraint of BS-LMC with blast-furnace slag 30% was bigger then that of opc. Also, the effects of added latex on OPC and BS-LMC were increased on the carbonation restraint and chemical attacks resistance.

• Journal of the Korean GEO-environmental Society
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• v.11 no.1
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• pp.53-59
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• 2010

In seawater deposition condition, the corrosion and chemical attack of grouts are similar to those of concrete structure. Used in domestic MSG (Micro Silica Grouting) mixtured large amounts of silicate materials containing as cement powder is $8,000cm^2/g$ of the specific surface area or more due to the high hydration activity and high-strength, high durability, and features, $C_3A$ content of less than 5% to meet the standards chemical attack of seawater was evaluated as a cement material. Therefore, in this paper, with excellent seawater attack resistant MSG in combination with rapid hardening mineral was used, those of seawater characteristics were evaluated experimentally. Typically, sodium-silicate minerals or rapid hardening cements are used in domestic. About the homogel specimens with combination of MSG and rapid hardening agents for compressive strength, weight and length change characteristics were evaluated experimentally, and so we could present the excellent seawater resistant grouts combination.

• Magazine of the Korea Concrete Institute
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• v.13 no.6
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• pp.52-57
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• 2001

• Bulletin of the Korean Chemical Society
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• v.28 no.10
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• pp.1797-1802
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• 2007

The kinetics and mechanism of the nucleophilic substitution reactions of diphenyl phosphinic (1) and thiophosphinic (2) chlorides with substituted X-pyridines are investigated kinetically in acetonitrile at 35.0 and 55.0 oC, respectively. A concerted mechanism with backside nucleophilic attack is proposed for the pyridinolysis of 1, on the basis of the linear Bronsted plot with the βX value of 0.68. In the case of the pyridinolysis of 2, the Hammett and Bronsted plots are biphasic concave upwards with the break point at 3- phenyl pyridine. These results indicate a change in mechanism from a concerted SN2(P) process with direct backside nucleophilic attack for less basic nucleophiles (X = 3-CN-3-Ph) to a stepwise process with frontside attack for more basic nucleophiles (X = 4-MeO-3-Ph). Apparent secondary inverse kinetic isotope effects with deuterated pyridine (C5D5N), kH/kD < 1, are observed for the pyridinolysis of 1 and 2.

• Bulletin of the Korean Chemical Society
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• v.32 no.6
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• pp.1997-2002
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• 2011

The nucleophilic substitution reactions of dicyclohexyl phosphinic chloride [3; $cHex_2$P(=O)Cl] with substituted anilines ($XC_6H_4NH_2$) and deuterated anilines ($XC_6H_4ND_2$) are investigated kinetically in acetonitrile at 60.0 $^{\circ}C$. The anilinolysis rate is too slow to be rationalized by the stereoelectronic effects. The rate is contrary to expectations for the electronic influence of the two ligands and exhibits exceptionally great negative deviation from the Taft's eq. The deuterium kinetic isotope effects (DKIEs) involving deuterated anilines invariably change from primary normal ($k_H/k_D$ > 1; max $k_H/k_D$ = 1.10 with X = 4-MeO) with the strongly basic anilines (X = 4-MeO, 4-Me, 3-Me) to secondary inverse ($k_H/k_D$ < 1; min $k_H/k_D$ = 0.673 with X = 3-Cl) with the weakly basic anilines (X = H, 4-F, 4-Cl, 3-Cl). A concerted $S_N2$ mechanism is proposed on the basis of both secondary inverse and primary normal DKIEs. The obtained DKIEs imply that the fraction of a frontside attack increases as the aniline becomes more basic. A hydrogen-bonded, four-center-type transition state is suggested for a frontside attack, while the trigonal bipyramidal pentacoordinate transition state is suggested for a backside attack.

• Bulletin of the Korean Chemical Society
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• v.32 no.8
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• pp.2628-2632
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• 2011

The nucleophilic substitution reactions of Y-O-aryl phenyl phosphonochloridothioates with substituted anilines ($XC_6H_4NH_2$) and deuterated anilines ($XC_6H_4ND_2$) are kinetically investigated in acetonitrile at $55.0^{\circ}C$. The deuterium kinetic isotope effects (DKIEs) invariably increase from an extremely large secondary inverse ($k_H/k_D$ = 0.439; min) to a primary normal ($k_H/k_D$ = 1.34; max) as both substituents of nucleophile (X) and substrate (Y) change from electron-donating to electron-withdrawing. These results are opposite to the DKIEs on Y-O-aryl methyl phosphonochloridothioates, and can be rationalized by the gradual transition state (TS) variation from backside to frontside attack. The trigonal bipyramidal pentacoordinate TS is proposed for a backside attack, while the hydrogen-bonded, four-center-type TS is proposed for a frontside attack. The negative values of the cross-interaction constants (${\rho}_{XY(H)}$ = -0.38 for $XC_6H_4NH_2$ and ${\rho}_{XY(D)}$ = -0.29 for $XC_6H_4ND_2$) indicate that the reactions proceed by a concerted $S_N2$ mechanism.