• 대한화학회지
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• 제20권1호
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• pp.59-72
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• 1976

수소화붕소아연의 선택환원성을 조사하기 위하여 대표적 유기화합물 54종을 택하여 수소화붕소 아연과 일정한 조건 (THF 용액, 실온, 수소화이온의 농도 : 0.5M, 유기화합물의 농도 : 0.125M)하에서 반응시켜 대략의 반응속도와 정량관계를 알아보았다.

• 대한화학회지
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• 제28권2호
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• pp.121-129
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• 1984

원료가 서로 다른 세종류의 국산활성탄을 사용하여 니켈 및 아연이온에 관한 할로겐과 시안이온의 활성탄 흡착에 대한 공존효과를 살펴보았다. 수용액중에서 니켈 및 아연이온은 할로겐이나 시안이온의 공존으로 착음이온 형태로 활성탄에 용이하게 흡착됨을 알 수 있었으며 니켈이온은 pH $6.0{\sim}7.0$에서, 아연이온은 pH $6.5{\sim}7.0$의 범위가 가장 적합함을 알았다. 또한 니켈이온과의 착음이온을 만들기 위한 음이온은$ 1{\times}10^{-2}mol/l$에서 그 최대치를 나타내었다. 실온에서 구한 이들의 흡착등온선은 거의 직선으로 Freundlich의 흡착등온식게 따랐으며, 시안이온 공존시의 기울기는 활성탄 A, B, C에 대해 각각 1.7, 5.4, 7.1로서 활성탄 A가 흡착제로서 매우 양호한 것을 알 수 있다.

• Environmental Analysis Health and Toxicology
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• 제20권2호
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• pp.167-178
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• 2005

This study was carried out to evaluate the temporal, spatial, and seasonal variations of VOC, and to characterize the VOC concentrations in two large industrial complexes located in Pohang and Gumi cities. Twenty -four hours continuous sampling of selected VOC was made with STS 25 sequential tube samplers and double-bed adsorbent tubes. Air samples were collected every three hour interval for 7 consecutive days in each site during summer and winter. VOC were determined by thermal desorption coupled with GC/MS. A total of 27 VOCs of environmental concern were determined, including aliphatic, aromatic and halides. Generally. concentrations of toxic VOC were higher in Gumi than Pohang, and VOC levels in industrial areas were typically several-fold higher than those in residential areas. The most abundant VOC appeared to be toluene for both cities. However, chlorinated VOC were higher in Gumi than Pohang, while aromatic VOC were more abundant in Pohang than in Gumi. Two cities showed relatively different variations of VOC concentrations within a day. It is likely that traffic related sources are major factors affecting the VOC in Pohang, and industrial solvents usages are important sources in Gumi. These results imply that the occurrence and levels of atmospheric VOC are strongly dependent on the type of industries in each city. Therefore, in order to develop any control strategies or to establish the priority rankings for VOC in large industrial complexes, the type of industries and the occurrence of VOC in the atmosphere should be taken into consideration.

• Korean Chemical Engineering Research
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• 제48권3호
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• pp.332-336
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• 2010

이미다졸염 형태의 이온성 액체를 구조유도체를 사용하지 않고 솔-젤 법으로 무정형 실리카에 담지시켜 고정화된 이온성 액체 촉매를 제조하였다. 이 촉매를 에틸렌카보네이트와 메탄올과의 에스테르 교환반응에 의한 디메틸카보네이트(DMC)의 합성 반응에 사용한 결과 우수한 촉매 활성을 나타내었다. DMC 합성 반응을 두 단계의 반응식으로 가정한 모델을 설정하여 반응온도와 촉매량을 변화시켜 실험한 결과와 비교한 속도론적 연구에서 실험 결과가 반응모델에 잘 일치하는 것을 알 수 있었다. 이로부터 계산한 유사 활성화 에너지 값은 67.4 kJ/mol 이었다.

• Korean Chemical Engineering Research
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• 제43권5호
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• pp.566-570
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• 2005

이중고리형 불포화탄화수소 화합물인 methylcyclopentadiene dimer(MCPD)의 수소화 및 이성화반응에 관한 연구를 행하였다. Exo 화합물은 2단계의 수소화반응 후에 이성화반응에 의해 제조되었다. 수소 1몰이 첨가되는 1차 수소화 반응은 $100^{\circ}C$이상의 반응온도에서는 다이머가 분해되어 모노머가 생성이 증가되었다. 1차 수소화 반응에 의하여 DHDMCPD[dihydrodi(methylcyclopentadiene)]가 생성된 후 2차 수소화반응을 진행하여 THDMCPD[tetrahydrodi (methylcyclopentadiene)]를 제조하였는데, 2차 반응온도조절에 의해 exo와 endo 비율이 변화되었다. 공정개선을 위하여 2단 가열반응기를 사용함으로 연속식 1, 2차 수소화 조건을 확립하였고 또한 endo THDMCPD로부터 exo 형태로 의 이성화반응에 할로겐화 알루미늄과 같은 할로겐화 금속촉매와 고체산 촉매를 사용하여 촉매의 활성을 비교하였다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 C
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• pp.1512-1514
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• 2001

In this work, PZT thin films were etched as a function of $Cl_2$/Ar and additive $CF_4$ into $Cl_2$(80%)/Ar(20%). The etch rates of PZT films were 1600 $\AA$/min at $Cl_2$(80%)/Ar(20%) gas mixing ratio and 1973 $\AA$/min at 30% additive $CF_4$ into $Cl_2$(80%)/Ar(20%). Therefore the etch rate of PZT in $CF_4/Cl_2/Ar$ plasma is faster than in $Cl_2$/Ar. From XPS and SIMS analysis, metal halides and C-O, FCI and $CClF_2$ were detected. The etching of PZT films in Cl-based plasma is primarily chemically assisted ion etching and the remove of nonvolatile etch byproducts is the dominant step. Consequently, we suggest that the increase of Cl radicals and the volatile oxy-compound such as $CO_y$ are made by adding $CF_4$ into $Cl_2$/Ar plasma. Therefore, the etch rate of PZT in $CF_4/Cl_2/Ar$ plasma is faster than in $Cl_2$/Ar. The etched profile of PZT films was obtained above 70$^{\circ}$ by the SEM micrograph.

• Bulletin of the Korean Chemical Society
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• 제35권12호
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• pp.3459-3464
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• 2014

Synthesis and structural characterization of mercury(II) halides and perchlorate complexes (1-4) of bis-$OS_2$-macrocycle (L) are reported. L reacts with mercury(II) chloride and bromide to yield an isostructural 2D coordination polymers with type $[Hg(L)X_2]_n$ (1: X = Cl and 2: X = Br). In 1, each Hg atom which lies outside the cavity is six-coordinate with a distorted octahedral geometry, being bound to four adjacent ligands via monodentate Hg-S bonds and two remaining sites are occupied by two terminal chlorido ligands to form a fishnet-like 2D structure. When reacting with mercury(II) iodide, L afforded a 1D coordination polymer $\{[Hg_2(L)I_4]{\cdot}CHCl_3\}_n$ (3) in which each exocyclic Hg atom is four-coordinate, being bound to two sulfur donors from different ligands doubly bridging the ligand molecules in a head-to-tail mode. The coordination sphere in 3 is completed by two iodo terminal ligands, adopting a distorted tetrahedral geometry. On reacting with mercury(II) perchlorate, L forms solvent-coordinated 1D coordination polymer $\{[Hg_2(L)(DMF)_6](ClO_4)_4{\cdot}2DMF\}_n$ (4) instead of the anion-coordination. In 4, the Hg atom is five-coordinate, being bound to two sulfur donors from two different ligands doubly bridging the ligand molecules in a side-by-side mode to form a ribbon-like 1D structure. The three remaining coordination sites in 4 are completed by three DMF molecules in a monodentate manner. Consequently, the different structures and connectivity patterns for the observed exocyclic coordination polymers depending on the anions used are influenced not only by the coordination ability of the anions but also by anion sizes.

• Archives of Plastic Surgery
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• 제36권1호
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• pp.113-117
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• 2009

Purpose: Although Hydrofluoric acid(HF) is not a strong acid when compared to other hydrogen halides, it is a feared corrosive and is particularly dangerous at higher concentrations. HF burns are characterized by symptoms, often delayed and localized with diluted HF solutions, to include erythema, edema and severe pain. Pain, a well known symptom following exposure to calcium binding. And, EMLA$^{(R)}$ cream is a topical formulation based upon the eutectic mixture of lidocaine and prilocaine and is used in clinical settings to provide pain relief undergoing superficial surgical procedures. The aim of this study is to evaluate effects of EMLA$^{(R)}$ cream, pain - control dressing on the treatment for HF injury wound. Methods: From June 2007 to June 2008, this study was carried out with 10 patients who had HF partial thickness burns. We were applied topically EMLA$^{(R)}$ cream to injured wound with vaseline gauze and 10% calcium gluconate wet gauze dressings. As a principle, in the emergency treatment, partial or complete removal of the bullae along with copious washing with normal saline was done, depending on the degree of HF invasion of the distal digital extremities. The effect of dressing was investigated by visual analogue pain scale. Results: We therefore reviewed 10 cases of HF - induced pain and pain relief treatment principle. The 10 cases who came to the hospital nearly immediately after the injury healed completely without sequelae and EMLA$^{(R)}$ related complications. Conclusion: Proper initial treatment of HF burns are important, if not promptly recognized and properly treated, for produce serious injury. Topical EMLA$^{(R)}$ cream remain a powerful, new advancement for minimizing HF - related pain during dressing procedures. When used appropriately, topical EMLA$^{(R)}$ cream can provide a safe and effective alternative to other forms of HF - pain control treatment.

• 대한화학회지
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• 제32권2호
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• pp.85-93
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• 1988

등유전상수 용매로 취급되는 MeOH-nitromethane, MeOH-nitrobenzene 및 MeOH-ethylene glycol 혼합용매 하에서 t-butyl halides (X = Cl, Br, I)의 가용매 분해반응을 연구 하였다. MeOH-NM 및 MeOH-NB에서 t-butyl halide의 가메탄올 분해반응 속도는 40~100 % (v/v) MeOH 조성에서 최대치를 보였다. 최대속도 현상은 용매의 극성-편극성과 수소결합 주게능력의 협력적인 결과로 설명하였다. Y값의 변화로 부터 극성-편극성과 수소 결합 주게능력의 협력적인 결과로 설명하였다. Y값의 변화로 부터 극성-편극성과 수소결합 주게능력이 기질의 반응성에 미치는 효과를 논의 하였다. E.G.에서 기질의 반응성은 MeOH에 비해 20배 이상 빠름을 보였으며 이는 아마도 E.G.의 특이한 용매구조에 기인 한다고 여겨 진다.

• Bulletin of the Korean Chemical Society
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• 제33권1호
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• pp.143-148
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• 2012

The photodissociation dynamics of cyclopropyl bromide ($C_3H_5Br$) and cyclobutyl bromide ($C_4H_7Br$) at 234 nm was investigated. A two-dimensional photofragment ion-imaging technique coupled with a [2+1] resonanceenhanced multiphoton ionization scheme was utilized to obtain speed and angular distributions of the nascent $Br(^2P_{3/2})$ and $Br^*(^2P_{1/2})$ atoms. The recoil anisotropies for the Br and $Br^*$ channels were measured to be ${\beta}_{Br}=0.92{\pm}0.03$ and ${\beta}_{Br^*}=1.52{\pm}0.04$ for $C_3H_5Br$ and ${\beta}_{Br}=1.10{\pm}0.03$ and ${\beta}_{Br^*}=1.49{\pm}0.05$ for $C_4H_7Br$. The relative quantum yield for Br was found to be ${\Phi}_{Br}=0.13{\pm}0.03$ and for $C_3H_5Br$ and $C_4H_7Br$, respectively. The soft radical limit of the impulsive model adequately modeled the related energy partitioning. The nonadiabatic transition probability from the 3A' and 4A' potential energy surfaces was estimated and discussed.