• Journal of Periodontal and Implant Science
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• 제31권2호
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• pp.333-344
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• 2001

The present study was performed to evaluate the effect of tetracycline - HCl on the change of implant surface microstructure according to application time. Implants with pure titanium machined surface and titanium plasma-sprayed surface were utilized. Implant surface was rubbed with 50mg/ml tetracycline - HCl solution for 1 min., $1\frac{1}{2}\;min$., 2 min., $2\frac{1}{2}\;min$. and 3min. respectively in the test group and with saline for 1 min. in the control group. Then, the specimens were processed for scanning electron microscopic observation. The following results were obtained. 1. Pure titanium machined surfaces conditioned with saline for 1 min., showed a few shallow grooves and ridges and were less irregular. 2. Pure titanium machined surfaces conditioned with 50mg/ml tetracycline - HCl solution showed more irregular and corrosive surfaces compared to the control group irrespective of the application time of tetracycline - HCl solution. 3. Titanium plasma-sprayed surfaces conditioned with saline for 1 min., were deposited with round amorphous particles and showed round or irregular pores that can be connected to each other. 4. The irregularity of titanium plasma-sprayed surfaces conditioned with 50mg/ml tetracycline - HCl solution was lessened and the flattened areas were wider relative to the application time of tetracycline - HCl solution. 5. Titanium plasma-sprayed surfaces conditioned with tetracycline - HCl solution for 1 min. and $1\frac{1}{2}\;min$. were very similar to that of the control group, but the surfaces conditioned for 2 min., $2\frac{1}{2}\; min$. and 3 min. were changed. In conclusion, pure titanium machined surfaces were changed irrespective of the application time of tetracycline - HCl solution. And titanium plasma-sprayed surfaces conditioned with tetracycline - HCl solution began to be changed from $1\frac{1}{2}\;min$. This results will be applicable to the regenerative procedures for peri-implantitis treatment.

• Bulletin of the Korean Chemical Society
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• 제30권10호
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• pp.2203-2207
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• 2009

Chemical equilbria of nickel chloride in HCl solution at $25\;{^{\circ}C}$ were analyzed by considering chemical equilibria, mass and charge balance equations. The activity coefficients of solutes were calculated by using Bromley equation. The necessary thermodynamic properties, such as the equilibrium constant for the formation of Ni$Cl^+$ at zero ionic strength and interaction parameter, were evaluated by applying Bromley equation to the stability constant data reported in the literature. It was found that most nickel exists as $Ni^{2+}$ in HCl solution up to 5 molality HCl. The pH values of Ni$Cl_2-HCl-H_2O$ system at $25\;{^{\circ}C}$ calculated in this study agreed well with the pH values measured by employing pH meter.

• 한국결정성장학회지
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• 제32권1호
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• pp.40-44
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• 2022

35 % 농도의 염산 용액을 이용하여 α-Ga₂O₃ epitaxy 박막의 습식 식각을 수행하였다. 35 % 염산 용액의 온도가 증가함에 따라 α-Ga₂O₃ epitaxy 박막의 식각 속도가 증가하였고, 본 연구에서 시도한 가장 높은 온도인 75℃에서 119.6 nm/min의 식각 속도를 나타내었다. 식각 반응의 활성화 에너지는 0.776 eV로 계산되었고, HCl 용액에서의 습식 식각은 reaction-limited 반응 기구에 의해 지배됨을 확인하였다. 각 온도에서 식각된 표면들의 AFM 분석결과 식각 용액의 온도가 증가함에 따라 식각된 표면의 표면조도가 증가함을 알 수 있었다.

• 약학회지
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• 제33권5호
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• pp.312-318
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• 1989

Microcapsule of Propranolol HCl with Cellulose Acetate Phthalate (CAP) by coacervation-phase separation method was studied. Encapsulation was carried out in the CAP-liquid paraffin-acetone ethanol solvent system. The optimum weight ratio for microencapsulation in the CAP-liquid paraffin-solvent system was 1.32:89.18:9.50 or 1.65:89.42:8.93. The wall thickness of microcapsules increased according to increasing of CAP concentration, but dissolution rate decreased. The dissolution of propranolol-HCl in simulated gastric and intestinal fluid test solution was completed within 3 min., but T50% of propranolol HCl from 10.0% CAP-microcapsules were 390 min. and 210 min. respectively. The released amount from 12.5% CAP-microcapsules was 41.8% within 720 min. in simulatd gastric fluid test solution and T50% of those in simulated intestinal fluid test solution was 250 min.

• 자원리싸이클링
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• 제26권3호
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• pp.26-31
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• 2017

LIX 63 은 6 M의 염산용액에서 백금(IV), 이리듐(IV) 및 로듐(III)에 비해 팔라듐(II)에 대한 선택성이 크다. 또한 염산용액의 농도는 이리듐과 LIX 63간에 일어나는 산화-환원반응에 큰 영향을 미친다. 따라서 상기 4개의 백금족 금속을 함유한 3 M의 염산용액에서 LIX 63에 의한 분리성을 검토하였다. 3 M의 염산용액에서 LIX 63은 오직 팔라듐만을 추출했으며, 6 M의 염산용액에 비해 추출율이 높았다. TBP를 사용하면 팔라듐 추출여액으로부터 백금만을 추출하는 것이 가능하였다. 백금 추출후 $NaClO_3$로 추출여액에 함유된 이리듐을 산화시킨 다음 Aliquat 336를 접촉시키면 이리듐만이 추출되었다. 각각의 용매추출단계에 대해 최적의 탈거조건을 구했다. 본 논문의 공정으로 4개의 백금족 금속을 3 M의 염산용액에서 분리하는 것이 가능하였다.

• 대한화학회지
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• 제56권4호
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• pp.401-405
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• 2012

Corrosion inhibition efficiencies of holy basil on Al in HCl solution were studied by weight loss and thermometric methods in presence and in absence of stem extract of three different varieties of holy basil viz. ocimum basilicum ($E_B$), ocimum canum ($E_C$) and ocimum sanctum ($E_S$). Inhibition efficiency increases with the increasing concentration of stem extract and decreases with increases in acid strength. Results show that all varieties under study are good corrosion inhibitors, among which, $E_B$ is most effective. Maximum inhibition efficiency was found 97.09% in 0.5N HCl solution with 0.6% stem extract. The Langmuir adsorption isotherm indicates that surface coverage also increases with increasing in the concentration of extract of stem in HCl solution.

• Bulletin of the Korean Chemical Society
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• 제32권1호
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• pp.113-116
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• 2011

Slope analysis method was applied to determine the stoichiometry of the solvent extraction reaction of Ni(II) by Alamine336 from strong HCl solution range from 1 to 10 M. Solvent extraction data was obtained from the literature. The effective equilibrium constant for the solvent extraction reaction was estimated by considering the ionic equilibria of $NiCl_2$ in the HCl solution. The measured distribution coefficients of Ni(II) agreed well with those calculated in this study. Our results suggest that further study on the measurement of the activities of nickel complexes at high HCl solution need to be done.

• 자원리싸이클링
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• 제24권5호
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• pp.80-86
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• 2015

In, Ga, Fe, Al이 함유되어 있는 혼합용액으로부터 In을 분리하기 위해 D2EHPA를 이용한 용매추출 연구를 수행하였으며, In의 추출에 대한 수상의 HCl 및 추출제 농도 효과를 확인하였다. In과 Ga의 추출률은 HCl 농도의 감소에 따라 증가하였지만, Fe와 Al의 추출률에는 큰 영향을 미치지 않았다. In과 Ga의 분리인자($D_{In}/D_{Ga}$)는 1.0 M D2EHPA, 0.5 M HCl조건에서 115로 나타났다. 즉, D2EHPA는 혼합용액으로부터 In을 분리하는 추출제로 적합하며, 추출률 및 분리인자는 HCl 및 추출제의 농도 조절을 이용하여 조절할 수 있다.

• 자원환경지질
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• 제46권1호
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• pp.21-28
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• 2013

저항성 황화광물 정광으로부터 금 용출을 최적화시키기 위하여 HCl-NaClO-$FeCl_3$ 용액과 다양한 변수를 유일광산 소성정광에 적용하였다. 유일광산의 gold는 용출시키기 어려운 비가시성 gold로 산출되었다. 다양한 변수를 이용하여 용출실험을 수행한 결과, 소성온도 $550^{\circ}C$, 첨가량 2.0 M, 광액농도 1.0% 그리고 용출온도 $70^{\circ}C$에서 최대의 gold 용출율을 얻었다. HCl-NaClO-$FeCl_3$ 용액은 황화광물 정광으로부터 금과 은을 친환경적으로 용출시킬 수 있는 시안 대체 용매제 일 것으로 사료된다.

• 대한화학회지
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• 제62권5호
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• pp.364-371
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• 2018

공기가 제거된 0.5 M HCl 과 0.5 M NaCl 용액에서 일어나는 알루미늄의 부식에 대하여 알라닌(Ala), 히스티딘(His) 과 메티오닌(Met)의 부식억제 효과를 조사하였다. HCl에 용해된 Ala, His, Met의 경우 모두 환원반응 속도가 감소되어 부식이 억제 되었으며, 부식억제 효율은 Met$10^{-4\;}M$ 보다 묽은 용액에서 Langmuir 흡착 등온식이 적용되었으나 $10^{-4\;}M$ 보다 진한 용액에서는 흡착된 분자 사이의 상호작용에 의하여 Temkin의 대수함수 등온식이 적용되었다.