• Bulletin of the Korean Chemical Society
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• 제6권4호
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• pp.183-186
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• 1985

The lattice vibrational calculation of orthorhombic hydrogen chloride is performed using physically realistic potential function which can reproduce the X-ray structure and heat of sublimation of the low temperature phase. The polar coordinates representation is introduced in order to describe the intermolecular interactions in a molecular crystal. The splitting in internal modes is calculated as 49 $cm^{-1}$ and the other modes are in good agreement with experimental results.

• Bulletin of the Korean Chemical Society
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• 제6권3호
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• pp.162-164
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• 1985

Nucleophilic substitution reaction of dansyl chloride with anilines in various solvents have been investigated. The Bronsted ${\beta}$ and Hammett ${\rho}_N$ values indicated that the bond formation is advanced more than the bond breaking at the transition state. Solvatochromic correlations also predicted the importance of bond formation at the TS, showing a greater contribution of polarity (${\pi}^{\ast}$) compared to hydrogen bond donor acidity (${\alpha}$). The effect of solvent on rate was found to violate the reactivity-selectivity principle.

• 한국산업보건학회지
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• 제16권1호
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• pp.68-80
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• 2006

This study aimed to prepare the fundamental data and assess the status and trend of exposure level for 5 chemical substances such as sulfuric acid, hydrogen chloride, ammonia, formaldehyde and phenol in manufacturing industry by type of industry, working process, and size of factory, chronological change. Subjects related to this study consist of 146 factories, 12 industries and 17 working processes located in Busan area from Jan. 1997 to Dec. 2001. 1. All 5 kinds of chemical substances by type of industry, working process were generated in chemical manufacturing industry. There were founded in 8 types of industries and 13 types of working processes for ammonia, which is the highest number of in all 5 chemical substances. 2. In terms of the exposure level for 5 chemical substances by type of industry, working process, geometric mean concentration for sulfuric acid was $0.40mg/m^3$ in manufacture of chemicals and chemical products, $0.30mg/m^3$ in compounding process, for hydrogen chloride was 0.57 ppm in manufacture of basic metal, 0.48 ppm in dyeing process, for ammonia was 1.11 ppm in manufacture of rubber and plastic products, 0.94 ppm in buffing process, for formaldehyde was 0.49 ppm in manufacture of wood and of products of wood and cork, except furniture; manufacture of articles straw and plating materials, 0.53 ppm in mixing process, and for phenol were 0.53 ppm in manufacture of chemical and chemical products, 0.55 ppm in compounding process, respectively. Results for 5 chemical substances by type of industry and working process were significantly higher than those of the others(p<0.05). 3. The exposure level for hydrogen chloride, formaldehyde were significantly increased by size of industry (p<0.01). ammonia was significantly decreased by size of industry (p<0.01). 4. In trend of the concentration difference of five chemical substances by chronology, geometric mean concentration for sulfuric acid was significantly increased (p<0.01), hydrogen chloride and ammonia were significantly decreased by year (p<0.05) and for formaldehyde and phenol were decreased in chronological change. According to the above results 5 chemical substances were founded together in a way mixed in the same places one another and concentrations of chemical substances by industry, working process, size of industry and year appeared markedly. The authors recommend more systemic and effective work environmental management should be conducted in workplaces generating five chemical substances.

• 한국수소및신에너지학회논문집
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• 제25권5호
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• pp.475-481
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• 2014

Ammonia borane ($NH_3BH_3$), as a source material for energy generation and hydrogen storage, has attracted growing interest due to its high hydrogen content. We have investigated the synthesis of ammonia borane from sodium borohydride ($NaBH_4$) and ammonium chloride ($NH_4Cl$) utilizing a low-temperature process. From our results, we obtained a maximum synthetic yield of 98.2% of ammonia borane complex. The diammoniate diborane (DADB) was detected in about 5~10mol% with in the solid ammonia borane by solid-state $^{11}B$-NMR analysis. The synthesized solid ammonia borane products were studied to characterize hydrogen release upon thermal dehydrogenation.

• 한국양식학회지
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• 제21권1호
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• pp.7-12
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• 2008

본 연구는 시판되는 10종의 소독제(hydrogen peroxide, sodium hypochlorite, chlorine dioxide, povidon iodine, formaldehyde, glutaraldehyde, quaternary ammonium compounds(QAC), didecyl dimethyl ammonium chloride(DDAC), ortho-dichlorobenzene, and copper sulfate)에 대한 CHSE-214 cell line과 넙치 Paralichthys olivaceus, 조피볼락 Sebastes pachycephalus, 감성돔 Acanthopagrus schlegelii에 대한 24 h $LC_{50}$ 농도를 측정하였다. 시험에 사용된 시판용 소독제에 대한 CHSE-214 cell line의 24 h 독성 농도는 시판액을 기준으로 hydrogen peroxide 0.955 ppm, sodium hypochlorite 12.5 ppm, chlorine dioxide 62.5 ppm, povidon iodine 50 ppm, formaldehyde 4 ppm, glutaraldehyde 1 ppm, quaternary ammonium compounds 10 ppm, didecyl dimethyl ammonium chloride 0.4 ppm, ortho-dichlorobenzene 6.2 ppm 이었다. 10종의 소독제의 독성 농도는 어종에 뿐만 아니라 각 소독제에 따라서도 매우 다양하게 관찰되었다. Hydrogen peroxide는 소독제 중에서 가장 높은 농도에서 어류에 대한 독성을 보였는데 넙치, 조피볼락 및 감성돔에 각각 201, 269 및 139 ppm에서 $LD_{50}$을 나타내었다. DDAC는 가장 낮은 농도에서 어류에 대한 독성을 보였는데 넙치, 조피볼락 및 감성돔에서 각각 2.1, 1.0 및 1.5 ppm에서 $LD_{50}$을 나타내었다. Copper sulfate는 어종에 따라 독성을 보이는 농도가 가장 크게 나타났다.

• 생명과학회지
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• 제23권11호
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• pp.1342-1350
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• 2013

본 연구는 화학적 허혈에 의해 손상된 마우스 간세포에서 hydrogen sulfide ($H_2S$)의 효과를 규명하기 위해 수행되었다. 본 연구에서 허혈 모방 화합물로 알려져 있는 cobalt chloride ($CoCl_2$)는 간세포 손상을 시간 및 농도 의존적으로 유의성 있게 증가 시켰다. $CoCl_2$에 의한 간세포 손상은 Sodium sulfide (NaHS, $H_2S$ 공여제)의 전처리에 의해 유의적으로 감소 되었다. $CoCl_2$는 세포 내 활성산소(reactive oxygen species, ROS)의 농도를 증가시켰으며, 이는 NaHS 및 N-acetyl-cysteine (NAC, a ROS 제거제)에 의해 감소하였다. 또한, $CoCl_2$에 의해 증가된 p38 MAPK 인산화가 NaHS 및 NAC에 의해 억제되었다. $CoCl_2$에 의해 증가된 Bax/Bcl-2 비율은 NaHS, NAC 및 SB 203580 (p38 MAPK 저해제)에 의해 차단되었으며, $CoCl_2$에 의해 유발된 간세포의 손상 또한 NaHS, NAC 및 SB 203580의 전처리에 의해 억제되었다. NaHS는 $CoCl_2$에 의해 증가된 COX-2의 발현을 억제하였다. 또한, NaHS의 효과와 유사하게 $CoCl_2$에 의해 증가된 COX-2의 발현이 NAC에 의해 억제되었다. 더욱이, NS-398 (COX-2 선택적 억제제)는 $CoCl_2$에 의한 Bax/Bcl-2 비율의 증가를 억제하였을 뿐 아니라, 간세포의 세포 손상 또한 억제하였다. 결론적으로, $H_2S$는 초대배양 된 마우스 간세포에서 $CoCl_2$에 의해 유발된 간세포의 손상을 ROS에 의해 유발된 p38 MAPK 및 COX-2 경로의 활성화를 억제함으로써 세포보호효과를 수행하는 것을 알 수 있었다.

• 한국표면공학회지
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• 제43권4호
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• pp.205-210
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• 2010

The A106 Gr B low carbon steel, which was used in the electric power plants and heavy chemical plants, was welded by multi-pass arc welding. The heat affected zone (HAZ) formed by welding was corroded in acid chloride solution, or in saturated $H_2S$ containing acid chloride solution, or in saturated $H_2S$ containing acid chloride solution under applied current. In this order of corrosion solution, the rate of corrosion increased, because $H_2S$ accelerated the iron dissolution, hydrogen evolution, and the formation of nonprotective FeS, whereas the applied current accelerated the electrochemical reaction. The scales formed in acid chloride solution consisted primarily of $Fe_3O_4$, while those formed in $H_2S$ containing acid chloride solution consisted primarily of $Fe_3O_4$ and FeS.

• 한국환경보건학회지
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• 제46권5호
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• pp.555-564
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• 2020

Objectives: To identify and investigate through qualitative and quantitative analysis the hazardous substances generated when compressed wood was burned at a live fire-training center. Methods: Four types of compressed wood that are actually used in live fire training were burned in a chamber according to KS F2271. The gaseous material was sampled with a gas detector tube and conventional personal samplers. Results: 1,3-butadiene, benzene, toluene, xylene, formaldehyde, hydrogen chloride, hydrogen cyanide, ammonia, carbon monoxide, and nitric acid were detected. In particular, 1,3-butadiene (497.04-680.44 ppm), benzene (97.79-125.02 ppm), formaldehyde (1.72-13.03 ppm), hydrogen chloride (4.71-15.66 ppm), hydrogen cyanide (3.64-8.57 ppm), and sulfuric acid (3.85-5.01 ppm) exceeded the Korean Occupational Exposure Limit as measured by sampling pump according to the type of compressed wood. Conclusions: We found through the chamber testing that firefighters could be exposed to toxic substances during live fire training. Therefore, firefighter protection is needed and more research is required in the field.

• Bulletin of the Korean Chemical Society
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• 제4권1호
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• pp.3-9
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• 1983

Lithium n-butylborohydride was prepared from borane-dimethylsulfide (BMS) and n-butyllithium, and the approximate rates and stoichiometrics of its reactions with selected organic compounds containing representative functional groups were studied in THF at room temperature. Phenol and benzenetiol liberated hydrogen quickly and quantitatively, and the reactions of primary alcohols, 2,6-di-ter-butylphenol and 1-hexanethiol liberated hydrogen quantitatively within 3 hrs, whereas the reactions of secondary and tertiary alcohols were very slow. Aldehydes and ketones were reduced rapidly and quantitatively to the corresponding alcohols. Cinnamaldehyde utilized 1 equiv. of hydride rapidly, suggesting the reduction to cinnamyl alcohol. Carboxylic acids evolved 1 equiv. of hydrogen rapidly and further reduction was not observed. Anhydrides utilized 2 equiv. of hydride rapidly but further hydride uptake was very slow, showing a half reduction. Acid chlorides were reduced to the alcohol stage very rapidly. All the esters examined were reduced to the corresponding alcohol rapidly. Lactones were also reduced rapidly. Expoxides took up 1 equiv. of hydride at a moderate rate to be reduced to the corresponding alcohols. Nitriles and primary amides were inert to this hydride system, whereas tertiary amide underwent slow reduction. Nitroethane and nitrobenzene were reduced slowly, however azobenzene and azoxybenzene were quite inert. Cyclohexanone oxime evolved 1 equiv. of hydrogen rapidly, but no further reduction was observed. Phenyl isocyanate and pyridine N-oxide were proceeded slowly, showing 1.74 and 1.53 hydride uptake, respectively in 24 hours. Diphenyl disulfide was reduced rapidly, whereas di-n-butyl disulfide, sulfone and sulfonic acids were inert or sluggish. n-Hexyl iodide and benzyl bromide reacted rapidly, but n-octyl bromide, n-octyl chloride, and benzyl chloride reacted very slowly.

• 한국위험물학회지
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• 제2권1호
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• pp.6-11
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• 2014

There have been frequent chemical leaks over the past 10 years. Particularly, inorganic acids like sulfuric acid, nitric acid, and hydrogen chloride take up 37 % of the total chemical accidents which took place for the past 10 years. When an acid chemical leak happens, fume is generated, diffusing into the air, which might cause serious damage to health of local residents and the environment. However, most of the acid-based chemicals, detecting and analysis methods have not been settled considering the frequency of accidents. In this study, we investigated detection and analysis methods to quickly analyze accident sites and evaluate the impacts on environments. Reviewing local and international test analysis methods of acids suggested that nitric acid, sulfuric acid, hydrogen chloride and hydrogen fluoride can be analyzed with IC. It was also found that UV is better for the analysis of hydrogen fluoride and GC/MS for acrylic acid. The analytical methods suggested in the official test methods basically have limitations of consuming much time at stages of preparation and analysis. Considering prompt responses to chemical accidents, further studies should be done to compare the applicability of rapid monitoring methods such as FT-IR, IMR-MS and SIFT-MS.