• Journal of Oral Medicine and Pain
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• v.23 no.4
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• pp.343-352
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• 1998

This experiment was performed to investigate effects of zinc containing solution on the major normal flora Staphylococccus aureus, Streptococus mutans and Candida albicans and to observe the variation according to anionic change and concentration difference. Zinc chloride, zinc iodide and zinc acetate solution were added to werially diluted broth culture so that each final concentration might be 0.25%, 0.5%. 1%. After that, 100ul of each aliquot was spreaded on each selective media plate( Mannitol Salts Agar plate for Staphylococcus aureus, Mitis Salivarius Agar plate for Streptococcus mutans and Sabouraud Destrose Agar plate for Candida albicans). The % killing was calculated bu CFU count after incubation under the appropriate condition. 1. zinc iodide, zinc chloride, and zinc acetate solutions showed inhibitory effects on Staphylococcus aureus, Streptococcus mutans and Candida albicans. 2. The inhibitory effects on Staphylococcus aureus were ranked in order of ainc iodide, zinc chloride and zinc actate. 3. The inhibitory effects on Streptococcus mutans were ranked in orfer of zinc iodide, zinc chloride and zinc acetate. 4. the inhibitory effects on Candida albicans showed no difference among zinc iodide, zinc chloride and zinc acetate. 5. The inhibitory effects of zinc chloride and zinc acetate on Staphylococcus aureus and Streptococcus mutnas showed increasing pattern as the concentration increase. But the inhibitory effects of zinc iodide on Staphylococcus aureus and Streptococcus mutans showed no apparent difference according to concentrations and it was the case with the inhibitory effects of zinc iodide, zinc chloride and zinc acetate on Candida albicans.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.2
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• pp.295-302
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• 2012

The coagulation of combined sewer overflows ($CSO_{s}$) was investigated by jar-testing with several commercial coagulants. $CSO_{s}$ sample showed different characteristics of coagulation from secondary wastewater with three common coagulants, aluminum sulfate, ferric chloride and polyaluminum chloride (PACl). Jar-tests showed that relatively wide range of optimal SS and T-P removal yielded with alum and ferric chloride compared with cationic polymers, though efficient SS and T-P removal can be achieved with all three coagulants. The decrease of pH was caused by the increase in dosage of aluminum sulfate, ferric chloride and PACl as coagulants. The pH was changed from 7.0 to 4.7 with the dosages of ferric chloride 25 mL/L. Aluminum sulfate revealed pH of 5.0 and PACl was highest pH of 5.4 after dosing of coagulants. The optimal pH to treat $CSO_{s}$ with aluminum sulfate were 6-6.5; with PACl 6-7, and with ferric chloride higher than 7.

• Journal of the Korean Society of Combustion
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• v.9 no.4
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• pp.28-34
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• 2004

Numerical simulations of freely propagating flames burning $H_2/HCl/Air$ Air mixtures were performed at atmospheric pressure in order to understand the effect of hydrogen chloride on flame structures. The chemical and physical effects of hydrogen chloride on flame structures were observed. A chemical kinetic mechanism was developed, which involved 26 gas-phase species and 198 forward elementary reactions. Under several equivalence ratios the flame speeds were calculated and compared with those obtained from the experiments, the results of which were in good agreement. As hydrogen chloride as additive was added into $H_2/Air$ flame, the flame speed, radical concentration and NO production rate were decreased. The chemical effect of hydrogen chloride caused the reduction of radical concentration, and then the decrease of the net rate of NO production. It was found that the influence in the reduction of $EI_{NO}$ with the addition of hydrogen chloride was attributed more due to the chemical effect than the physical effect.

• International Journal of Concrete Structures and Materials
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• v.4 no.2
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• pp.109-112
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• 2010

Part I of this study was devoted to the electrical accelerated chloride diffusion in mortars. In this second part, natural chloride diffusion has been investigated for four types of mortars under exposure to a 0.5 mol/L NaCl solution for a period of up to 35 days. Two different types of sand were used for the production of test samples: siliceous sand (used as a reference) and limestone sand (used in this study). The effect of water to cement ratio and exposure time on the diffusion coefficients of mortars was also investigated. In this study, the total and free chloride content and penetration depth of mortar were measured after immersion, and Fick's second law of diffusion was fitted to the experimental data to determine the diffusion coefficient. Their results show that the use of crushed limestone sand in mortar had a positive effect on the chloride resistance. The apparent diffusion coefficient in all specimens was smaller than that in siliceous sand mortar. However, the chloride penetration of these mortars was increased as exposure time progressed.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.442-442
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• 2013

ZnO의 나노 구조는 화학적으로 안정하고 큰 결합에너지를 가지는 성질 때문에 청색 영역에서 작동하는 광전소자의 제작에 대단히 유용하다. 전기 화학 증착법으로 성장된 ZnO의 나노구조는 가격이 저렴하고 낮은 온도에서 성장이 가능하며 대면적화를 할 수 있는 장점이 있다. 전기 화학 증착법으로 ZnO을 성장할 때 ITO 기판을 음극으로 백금 전극을 양극으로 사용하였고 기준 전극은 Ag/AgCl을 사용하였다. Potassium chloride의 몰 농도를 변화하면서 ZnO 나노구조를 성장하였다. 성장한 ZnO 나노구조를 $400^{\circ}C$에서 2분 정도 열처리를 하였다. 성장된 ZnO을 X-선 회절 결과는 (0002) 피크가 $34.35^{\circ}$에서 나타났다. 주사 전자 현미경상은 Potassium chloride의 몰 농도가 낮을 때 성장한 ZnO 나노구조체가 고르게 성장되는 것을 알 수 있었다. Potassium chloride의 농도가 변화하면 ZnO 나노구조체의 형태가 변화하는 것을 알 수 있었다. 300 K에서 광루미네선스 스펙트럼은 형성된 나노구조가 엑시톤과 관련된 피크가 potassium chloride 농도에 따라 변화하게 되는 것을 알 수 있었다. 이 실험결과는 ZnO 나노구조의미세구조와 광학적 성질이 potassium chloride의 농도에 영향을 많이 받는 것을 알 수 있었다.

• Computers and Concrete
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• v.8 no.3
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• pp.343-355
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• 2011

This paper presented the model to predict the chloride diffusion coefficient in tension zone of plain concrete under flexural cyclic load. The fictitious crack based analytical model was used together with the stress degradation law in cracked zone to predict crack growth of plain concrete beams under flexural cyclic load. Then, under cyclic load, the chloride diffusion, in the steady state and one dimensional regime, through the tension zone of the plain concrete beam, in which microcracks were formed by a large number of cycles, was simulated with assumptions of continuously straight crack and uniform-size crack. The numerical analysis in terms of the chloride diffusion coefficient, $D_{tot}$, normalized $D_{tot}$, crack width and crack length was issued as a function of the load cycle, N, and load level, SR. The nonlinear model as regarding with the chloride diffusion coefficient in tension zone and the load level was proposed. According to this model, the chloride diffusion increases with increasing load level. The predictions using model fit well with experimental data when we adopted suitable crack density and tortuosity parameter.

• Journal of the Korean Chemical Society
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• v.9 no.1
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• pp.23-28
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• 1965

Halogen exchanges between benzyl chloride and chloride ion have been studied in 90% ethanol-water mixture, and activation parameters in the exchange reaction have been determined; ${\Delta}H^{\neq}$ = 18. 50 Kcal and ${\Delta}S^{\neq}$ = -22. 09 e. u. Results indicated that the reaction proceeded via a typical bimolecular mechanism. The importance of nucleophilic ability of attacking anion in $S_N2$ process has been stressed giving some experimental evidence. The order of reactivity of halides in the exchange reaction is better explained with the Swain's nucleophilic parameter than with the bond dissociation energies.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.259-260
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• 2009

Many concrete structures have suffered from carbonation or chloride ion diffusion induced reinforcement corrosion, and a number of studies have been done on these topics. Many studies were mostly confined to the single deterioration of carbonation or chloride ion, although the environment actually presents a combined condition. This paper tried to develop the approach to compute re-diffusion of de-sorbed chloride due to carbonation of concrete. This is a key for successful combined deterioration model of carbonation and chloride. It is thought that this paper can contribute to express mathematically chloride enrichment and re-diffusion of chloride at front of carbonation.

• Computers and Concrete
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• v.21 no.4
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• pp.471-484
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• 2018

Refined analysis depicting mass transportation and physicochemical reaction and reasonable computing load with acceptable DOFs are the two major challenges of numerical simulation for concrete durability. Mesoscopic numerical simulation for chloride diffusion considering binder, aggregate and interfacial transition zone is unable to be expended to the full structure due to huge number of DOFs. In this paper, a multiscale approach of combining both mesoscopic model including full-graded aggregate and equivalent macroscopic model was introduced. An equivalent conversion of chloride content at the Interfacial Transition Layer (ITL) connecting both models was considered. Feasibility and relative error were discussed by analytical deduction and numerical simulation. Case study clearly showed that larger analysis model in multiscale model expanded the diffusion space of chloride ion and decreased chloride content in front of rebar. Difference for single-scale simulation and multiscale approach was observed. Finally, this paper addressed some worth-noting conclusions about the chloride distribution and rebar corrosion regarding the configuration of rebar placement, rebar diameter, concrete cover and exposure period.

• Journal of Chest Surgery
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• v.21 no.2
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• pp.240-245
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• 1988

This study was prospectively planned to realize the reduction of calcium ion in serum along with the cardiopulmonary bypass[CPB], to find out the cause of the reduction, and to verify the justification of the classical methods of calcium replacement. Nine patients with various open heart surgeries by CPB in 1987 wee selected at random. Calcium chloride was added as follows:: For each unit of ACD blood transfusion, 600mg of calcium chloride was added. In case of massive transfusion, 600 mg of calcium chloride was injected every 2 or 3 units of transfusion. On occasions such as weaning from CPB, or following defibrillation, or hypotension, weak myocardial contractility of the heart, calcium chloride was needed in an amount of 10 mg / kg. In ICU, calcium chloride was limited to use in low serum level or in emergency use. Total calcium decreased early bypass and progressively increased above the preoperative value during late bypass and three hours thereafter, Ionized calcium increased during late bypass and three hours following. Total and ionized calcium depicted similar patterns of change during open heart surgery. Decrease of the calcium at the early bypass was thought from reduction of total protein and alkalosis during bypass. Meanwhile, increase of both calciums during the end of surgery was presumably attributable to addition of calcium chloride in priming solution, injections of calcium chloride in the process of termination of bypass. We conclude that enough calcium was replaced by the classical methods of calcium supplement.