• Bulletin of the Korean Chemical Society
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• 제33권11호
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• pp.3539-3543
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• 2012

Butacaine sulfate is an ester of p-aminobenzoic acid which has been widely used as a local anaesthetic and it is a long standing agent particularly for spinal anaesthesia. For this reason, a kinetic study of oxidation of butacaine sulfate by sodium N-chlorobenzenesulfonamide (chloramine-B or CAB) has been carried out in $HClO_4$ medium at 303 K in order to explore this redox system mechanistic chemistry. The rate shows a first-order dependence on both $[CAB]_o$, and $[substrate]_o$, and a fractional-order dependence on acid concentration. Decrease of dielectric constant of the medium, by adding methanol, increases the rate of the reaction. Variation of ionic strength and addition of benzenesulfonamide or NaCl have no significant effect on the rate. The reaction was studied at different temperatures and the activation parameters have been evaluated. The stoichiometry of the reaction has been found to be 1:2 and the oxidation products have been identified by spectral analysis. The observed results have been explained by plausible mechanism and the related rate law has been deduced.

• Journal of Pharmaceutical Investigation
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• 제36권5호
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• pp.321-329
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• 2006

Albuterol, a selective ${\beta}_2$-adrenergic receptor stimulant, has been introduced as a potent bronchodilator for patients with bronchial asthma, chronic obstructive bronchial disease, chronic bronchitis and pulmonary emphysema. The percutaneous permeation of albuterol sulfate was investigated in hairless mouse skin in vitro with and without pretreatment with enhancers. The enhancing effects of ethanol and various penetration enhancers such as terpenes, non-ionic surfactants, pyrrolidones, and fatty acids on the permeation of albuterol sulfate were evaluated using Franz diffusion cells. Among terpenes studied, 1,8-cineole was the most effective enhancer, which increased the permeability of albuterol sulfate approximately 33-fold compared with the control without enhancer pretrement, followed by d-limonene with enhancement ratio of 21.79. 2-Pyrrolidone-5-carboxylic acid increased the permeability of albuterol sulfate approximately 5.5-fold compared with the control. Other pyrrolidones tested showed only slight permeability enhancing effect with enhancement ratio less than 2.8. Nonionic surfactants showed moderate enhancing effects. Lauric acid increased the permeability of albuterol sulfate approximately 30-fold with decreasing the lag time from 2.85 to 0.64 hr. Oleic acid and linoleic acid showed enhancement ratio of 24.55 and 22.91, respectively. These findings would allow a more rational approach for designing formulations for the transdermal delivery of albuterol sulfate and similar drugs.

• 한국표면공학회지
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• 제37권2호
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• pp.86-91
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• 2004

Effect of potassium formate, glycine and oxalic acid in a sulfate solution on the deposit composition and current efficiency of trivalent chromium plating was studied. The trivalent chromium layers prepared by solutions with potassium formate, glycine and oxalic acid contain a few carbon inside. The solutions containing potassium formate, glycine and oxalic acid are relatively stable with pH change. The solution with the potassium formate shows 6-30％ current efficiency with current density, whereas, the solutions with oxalic acid and glycine show about 5％ current efficiency, respectively. The improved current efficiency is related to enough supply of chromium ions to the electrode due to the increase of pH at the front of electrode.

• 지질공학
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• 제28권1호
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• pp.25-34
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• 2018

본 연구에서는 산성토를 대상으로 물리적 특성과 불포화 특성을 조사 및 분석하였다. 부산 일광광산 주변의 산성토를 대상으로 물리적 특성을 조사한 결과 건조단위중량이 $1.246t/m^3$이며, 통일분류법(USCS)상 실트질 모래(SM)에 해당된다. 자동 흙-함수특성곡선(SWCC) 측정장치를 이용하여 건조 및 습윤과정에 대한 흙-함수특성곡선(SWCC)을 산정하였다. 그리고 계수예측방법 가운데 가장 널리 활용되고 있는 van Genuchten (1980) 모델을 적용하여 건조 및 습윤과정에 따른 산성토의 불포화 투수계수함수(HCF)를 산정하였다. 산성토의 불포화 투수계수함수(HCF)는 건조과정의 경우 모관흡수력이 증가함에 따라 지속적으로 감소하지만 습윤과정의 경우 모관흡수력이 낮은 수준에서 상대적으로 작게 감소하고, 수분함입치 직전에 크게 감소함을 알 수 있다. 한편, 건조 및 습윤과정에서의 흙-함수특성곡선과 불포화 투수계수함수는 모두 이력현상이 발생되었다.

• 자원리싸이클링
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• 제21권5호
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• pp.50-57
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• 2012

황산동 용액중에 불순물로 존재하는 Sb, Bi 및 As를 제거하기 위해 Aminophosphosphonic acid를 관능기로 함유한 이온교환수지를 사용하여 비교 실험을 실시하였다. 이들 불순물 제거 반응에 영향을 미칠 수 있는 반응온도, 반응시간, 이온교환수지양 등에 대하여 고찰하였다. 기초 실험 결과 약 88%의 Sb 및 94%의 Bi가 이온교환수지에 흡착되어 황산동용액으로부터 제거가 가능하였다. 그러나 As의 경우는 제거율이 10% 이하로 미미하였다. 한편, Bi 와 Sb가 흡착된 수지에서 황산과 염산용액을 이용하여 선택적으로 세출이 가능하였다. 연속흡착실험 결과 Sb 와 Bi의 경우는 2BV 후에는 98.1%와 96.6%의 높은 흡착율을 보였다.

• Journal of Microbiology and Biotechnology
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• 제23권2호
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• pp.211-217
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• 2013

Corynebacterium glutamicum is one of the well-studied industrial strain that is used for the production of nucleotides and amino acids. Recently, it has also been studied as a possible producer of organic acids such as succinic acid, based on its ability to produce organic acids under an oxygen deprivation condition. In this study, we conducted the optimization of medium components for improved succinate production from C. glutamicum under an oxygen deprivation condition by Plackett-Burman design and applied a response surface methodology. A Plackett-Burman design for ten factors such as glucose, ammonium sulfate, magnesium sulfate, potassium phosphate ($K_2HPO_4$ and $KH_2PO_4$), iron sulfate, manganese sulfate, biotin, thiamine, and sodium bicarbonate was applied to evaluate the effects on succinate production. Glucose, ammonium sulfate, magnesium sulfate, and dipotassium phosphate were found to have significant influence on succinate production, and the optimal concentrations of these four factors were sequentially investigated by the response surface methodology using a Box-Behnken design. The optimal medium components obtained for achieving maximum concentration of succinic acid were as follows: glucose 10 g/l, magnesium sulfate 0.5 g/l, dipotassium phosphate ($K_2HPO_4$) 0.75 g/l, potassium dihydrogen phosphate ($KH_2PO_4$) 0.5 g/l, iron sulfate 6 mg/l, manganese sulfate 4.2 mg/l, biotin 0.2 mg/l, thiamine 0.2 mg/l, and sodium bicarbonate 100 mM. The parameters that differed from a normal BT medium were glucose changed from 40 g/l to 10 g/l, dipotassium phosphate ($K_2HPO_4$) 0.5 g/l changed to 0.75 g/l, and ammonium sulfate ($(NH_4)_2SO_4$) 7 g/l changed to 0 g/l. Under these conditions, the final succinic acid concentration was 16.3 mM, which is about 1.46 fold higher than the original medium (11.1 mM) at 24 h. This work showed the improvement of succinate production by a simple change of media components deduced from sequential optimization.

• 복식문화연구
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• 제11권3호
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• pp.416-422
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• 2003

Agricultural drainage salt generated during irrigation of crops in San Joaquin Valley, California, exceeds 600,000 tons annually and cumulates in the field in a rapid rate. As a result, the waste is taking out more farmlands for salt storage and disposal, imposing serious concerns to environment and local agricultural industry. In searching for a potential solution to reduce or eliminate the waste, this research explored feasibility of producing a value-added product, sodium sulfate, from the waste and utilizing the product in textile dyeing. The results indicated that sodium sulfate could be produced from the salt and could be purified by a recrystalization method in a temperature range within the highest and lowest daily temperatures in summer in the valley. The recovered sodium sulfate samples, with purities ranging from 67% to 99.91, were compared with commercially available sodium sulfate in the dyeing of levelling dyes with nylon/wool fabrics. In nylon/wool fabrics, C.I. Acid Yellow 23 had similar exhaustions among Na₂SO₄ I, Na₂SO₄ II, Na₂SO₄ III and Na₂SO₄ Ⅴ which had similar ratios of sodium sulfate and sodium chloride in recovered salts. Na₂SO₄ Ⅳ had low exhaustion which had low ratios of sodium sulfate and sodium chloride. In nylon/wool fabrics, C.I. Acid Blue 158 had similar exhaustions among Na₂SO₄ I, Na₂SO₄ II, Na2₂SO₄ III, Na₂SO₄ IV and Na₂SO₄ Ⅴ despite of Na₂SO₄ Ⅳ had low ratios of sodium sulfate and sodium chloride Generally, the dyeing of levelling dyes using recovered salts from farm drainage has similar or low exhaustion than the dyeing of levelling dyes using commercial sodium sulfate.

• 한국세라믹학회지
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• 제26권1호
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• pp.81-90
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• 1989

High purity alumina and amorphous silica were prepared from Ha-dong kaolin by means of appliance of sulfuric acid. The effect of sulfuric acid concentration, reaction temperature and reaction time on the formation of aluminum sulfate was investigated. The precipitation conditions ofaluminum sulfate from the sulfuric acid solution with ethanol and ammonium hydroxide were deteremined. In the optimum condition, the conversion of aluminum oxide in kaolin to aluminum oxide powder was 85.0 percent. Alumina powder was prepared by calcination of the precipitates, and its purity was 99.0 percent.

• Journal of Pharmaceutical Investigation
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• 제20권3호
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• pp.121-127
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• 1990

Mefenamic acid has been widely used clinically as an anti-inflammatory analgesic. It has poor solubility in water $(41\;{\mu}g/ml)$ and there is the difficulty of dissolution in the mefenamic acid capsules. A study was made to investigate the effect of various surfactants on the dissolution of mefenamic acid capsules. The surfactants used were sodium lauryl sulfate (SLS), Pluronic F-68, F-77, and F-127. Mefenamic acid capsule containing surfactant showed significantly improved dissolution characteristics. The dissolution rate was fast in the order of SLS > F-77 > F-68 > F-127 in mefenamic acid capsules containing 0.2 w/w % surfactant. SLS was selected for further study on the bioavailability in rabbits. The area under the plasma concentration-time curve $(AUC_{0-24})$ of mefenamic acid capsule containing SLS was higher than one of mefenamic acid capsule not containing surfactant.

• 한국염색가공학회지
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• 제5권2호
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• pp.117-124
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• 1993

The Silk fabric was dyed with various acid dyes, and than treated with copper sulfate or copper sulfate/thiourea. Munsell color system, dye exhaustion and light fastness were investigated for the treated fabrics. The results obtaind are as follows: 1) The color variation of the silk-dyed fabric by aftertreatment with copper sulfate was shown redish, but original color with copper sulfate/thiourea. 2) Copper sulfate/thiourea was much more effective than copper sulfate only to increase the light fastness. 3) The crease recovery was increased by aftertreatment with copper sulfate/thiourea. 4) Dye exhaustion and tensile strength of the silk-dyed fabric by aftertreatment with copper sulfate was decreased about 8-15% more than those of untreated.