• Clean Technology
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• v.15 no.1
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• pp.42-46
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• 2009

Solvent-free direct preparation of dichloropropanol (DCP) from glycerol (by-product of bio-diesel production) and hydrochloric acid gas was carried out over acetin catalyst in a gas-liquid batch reactor. For this purpose, acetin mixture and triacetin were used as a homogeneous acetin catalyst. Performance in the acetin-catalyzed reaction was compared to that in the non-catalytic reaction under the same reaction conditions ($110^{\circ}C$, 3 bar, 3 h). Conversion of glycerol in the acetin-catalyzed reactions was ca. 3% higher than that in the non-catalytic reaction, and selectivity for dichloropropanol in the acetin-catalyzed reactions was ca. 50% higher than that in the non-catalytic reaction. It was also revealed that the catalytic performance of triacetin was ca. 2% higher than that of acetic mixture.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.3
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• pp.290-298
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• 2018

This study aimed to evaluate surface morphology and resin tag penetration of resin infiltration into primary anterior teeth after enamel deproteinization with sodium hypochlorite (NaOCl) prior to phosphoric acid ($H_3PO_4$) etching. Ninety primary anterior teeth with non-cavitated caries lesion were devided five groups according to enamel pretreatment as follows, group I-15% hydrochloric acid (HCl) 2min. ; group II-5.25% NaOCl 1min., 35% $H_3PO_4$ 1min. ; group III-5.25% NaOCl 2min., 35% $H_3PO_4$ 1min. ; group IV-5.25% NaOCl 1min., 35% $H_3PO_4$ 2min. ; group V-5.25% NaOCl 2min., 35% $H_3PO_4$ 2min. Fifteen teeth were examined etched surface structure using field emission-scanning electron microscope. Seventy five teeth were infiltrated with resin, maximum penetration depth and percentage penetration were analysed using dual fluorescence confocal microscopy. As the application time of NaOCl increased, ratio of enamel type I, II were increased. Percentage penetration (PP) was higher in group V than group II, III (p < 0.05). PP of group IV, V did not show any differences. Non-cavitated caries of primary anterior teeth can be treated with resin infiltration. Enamel deproteinization with NaOCl prior to 35% $H_3PO_4$ etching could be an alternative of 15% HCl etching in resin infiltration.

• The Korean Journal of Food And Nutrition
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• v.12 no.5
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• pp.455-461
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• 1999

The possibility of wine making from soft and dried persimmon and the effects of treatment for persimmon on the quality of wine have been investigated. Soft persimmon was pretreated by two method of heat and hydrochloric acid treatment. Fermentation mash was composed of 12% persimmon and 15% of sucrose and was fermented at 17$^{\circ}C$ for 36 days. The fermentation using persimmons which were untreated and treated by acid was not successful because of contamination caused by lactic acid and acetic acid bacteria. Acidity of the fermented broth produced from boiled dried acid treated and untreated persimmon was 4,4, 5.0, 5,8 and 13.5ml(0.1N NaOH/10ml broth) respectively. Ethanol concentration of the fermented broth produced from boiled dried acid treated and untreated persimmon was 11.2, 10.0, 9.4 and 6.1% v/v respectively. The wine fermented for 28day's fermentation using boiled persimmon as substate had the best quality and stability. After 36day's fermentation using boild persimon following composition was obtained: 4.65% of total sugar 3.65% of reducing sugar 0.03mg/ml of protin 0.17$\mu$/ml of amino acid and 13.02 $\mu$g/ml of pectin. The pH and yeast cell of the boiled persimmon broth were 3.4 and 5.75 logCFU/ml. Fermented wine using dried persimmon had aslo good quality but the fermentation rate was slow.

• Journal of Pharmaceutical Investigation
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• v.3 no.1_2
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• pp.5-15
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• 1973

Fluorometric determination of dl-Methylephedrine hydrochloride from complex preparation were studied. According to the experimental results and considerations obtained the results for the following. (1) dl-Methylephedrine hydrochloride in Hydrochloric acid media occurs the fluorescens by Picrolonic acid and Cuppric acetate. (2) The maximum absorption fluorescence wave length of dl-Methylephedrine hydrochloride standard solution is $365m{\mu}$. (3) The relationship between the fluorescence proportions to concentration of standard solution at range of $4.2{\times}10^{-4}\;M$. $6{\times}10^{-4}M$. (4) dl-Methylephedrine hydrochloride was precisely determined even in the presence of various components, especially Chloropheniramine maleate, Dextromethorphan hydrobromide and Diphenylhydramine hydrochloride. (5) This method has high sensitivity and is simple in precedure. (6) This method be applicable with 99.79% accuracy and was 99.5% in complex preparation.

• Journal of the Korean Chemical Society
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• v.15 no.1
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• pp.5-9
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• 1971

A separation scheme using cation exchange procedure is designed specifically for the rapid determination of thorium in monazite samples. All the coexisting ions in monazite, including rare earth ions, are eluted with 3N hydrochloric acid. The remaining thorium is eluted from the resin column with 5N sulfuric acid prior to spectrophotometric determination with thorin reagent. The radioactive tracers and spectrophotometric methods were used to confirm the quantitative elution of thorium and also the chemical purity of the eluted thorium from the column.

• Journal of Powder Materials
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• v.22 no.1
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• pp.15-20
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• 2015

The composite of porous silicon (Si) and amorphous carbon (C) is prepared by pyrolysis of a nano-porous Si + pitch mixture. The nano-porous Si is prepared by mechanical milling of magnesium powder with silicon monoxide (SiO) followed by removal of MgO with hydrochloric acid (etching process). The Brunauer-Emmett-Teller (BET) surface area of porous Si ($64.52m^2g^{-1}$) is much higher than that before etching Si/MgO ($4.28m^2g^{-1}$) which indicates pores are formed in Si after the etching process. Cycling stability is examined for the nano-porous Si + C composite and the result is compared with the composite of nonporous Si + C. The capacity retention of the former composite is 59.6% after 50 charge/discharge cycles while the latter shows only 28.0%. The pores of Si formed after the etching process is believed to accommodate large volumetric change of Si during charging and discharging process.

• The Korean Journal of Nuclear Medicine
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• v.22 no.2
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• pp.193-197
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• 1988

Measurement of gastric emptying rate has been performed by a variety of techniques. Nuclear medicine method is a major advance in the quantitative evaluation of gastric function and also of pharmacologic intervention. Normal gastric emptying rate was measured in 48 healthy volunteers using live chicken liver labeled with $^{99m}Tc-Tin$ Colloid as a solid phase marker. In vitro studies were performed to evaluate the labeling efficiency and stability in hydrochloric acid and in human gastric juice of intracellularly labeled chicken liver. Anterior image counts only were compared with the geometric mean of anterior and posterior counts in 12 healthy volunteers who were studied by both anterior count and posterior count. The results were as follows: 1) The labeling efficiency in gastric juice and hydrochloric acid were $95.5{\pm}1.23%,\;95.7{\pm}1.15%$, respectively. 2) Half gastric emptying time by anterior count only was $126{\pm}21$ minutes 3) Although standard deviation of geometric mean method was smaller than anterior count method, gastric emptying curves from both method were similar. In daily practice, anterior count method may be useful alternative to geometric mean method in evaluation of gastric emptying rate.

• The KSFM Journal of Fluid Machinery
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• v.19 no.4
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• pp.35-38
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• 2016

A PFA lined ball valve, which is machined with fluorinated resin PFA to its inner part for improving corrosion resistance, non-stickness, heat-resistance, has been widely used in semiconductor/LCD manufacturing processes with the high purity chemicals as working fluid. Due to the safety concerns, the experiments for measuring the flow coefficient of a PFA lined ball valve should be conducted with water at room temperature according to IEC standards. However, it is required to know the real flow coefficient with the real working fluid, because the flow coefficient is critical to correctly design valves in piping system. In this study, we calculated the flow coefficient of a PFA lined ball valve 40A with hydrochloric acid ($40^{\circ}C$ 36% HCl) as the working fluid using a commercial CFD package, ANSYS CFX v15. The computational results had a good agreement with the measured data and showed a little difference between water and hydrochloric acid as the working fluid of a PFA lined ball valve.

• Economic and Environmental Geology
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• v.53 no.4
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• pp.337-346
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• 2020

This study was carried out to evaluate the applicability of the soil washing process to remediation mercury-contaminated mine tailing or solid material (soil and sediments etc.) around abandoned mines. First, the physicochemical characteristics of mine tailing were analyzed through particle size analysis and sequential extraction. Secondly, laboratory scale washing experiments were performed using hydrochloric acid, nitric acid, potassium iodide and sodium thiosulfate. As a results of particle size analysis, mine tailing particle were concentrated below 40 mesh and the particle size below 200 mesh was the most analyzed. As a result of sequential extraction, elemental mercury fraction was analyzed as the highest with 69.12%, with strongly bound fraction 15.25% and residual and HgS fractions 11.97%, respectively. Laboratory scale washing experiments showed low applicability for nitric acid and sodium thiosulfate solutions. In case of hydrochloric acid solution, it was analyzed that mercury removal was possible at particle size of 200 mesh or more. Therefore, it is considered to be performed together with the physical sorting process. Potassium iodide solution was analyzed to have high washing efficiency at all concentrations and particle sizes. In particular, the mercury removal efficiency is high in the micro particles, and thus the applicability of the washing technology is the highest.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.11
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• pp.1542-1548
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• 2001

Wheat straw was treated on laboratory scale with 4% urea at a moisture level of 50% along with different amount of HC1 to fix various levels of ammonia (30, 40, 50 and 60%) and stored for 4 weeks. Result, revealed a significant (p<0.01) increase in CP content of the samples where HC1 was added. The CP content of the straw was only 7.8%, which increased to 14.1, 16.0, 15.0 and 15.2% with the addition of acid. Similarly the concentrations of NDF, ADF and hemicellulose was significantly different due to HC1 addition. The level of HC1 recommended was to trap 30% ammonia as there was not significant difference in CP content of straw due to addition of 4 levels of acids. Results of in vivo experiment conducted on nine buffaloes divided randomly into three groups of three animals in each revealed no significant difference in the intake of DM, OM, NDF, ADF, cellulose and hemicellulose in group I (ammoniated straw), group II (HC1 treated ammoniated straw) and group III (HC1 treated ammoniated straw + 1 kg barley grain), but the intake of CP was significantly (p<0.01) more in group III as compared to other 2 groups. The digestibility of DM, OM and CP was significantly (p<0.01) more in groups where HCI treated straw was fed as compared to only ammoniated straw fed group, whereas there was no significant difference in the digestibility of NDF, ADF and cellulose in 3 groups. Intake was significantly higher of nitrogen (p<0.05), calcium (p<0.01) and phosphorus (p<0.01) in group III as compared to other two groups. Animals in all the 3 groups showed positive nitrogen, calcium and phosphorus balance, though the balances of all the 3 nutrients were significantly higher in group III as compared to other 2 groups. Rumen fermentation study conducted in 3 rumen fistulated buffaloes in $3{\times}3$ latin square design offering the same 3 diets as in group I to III revealed that rumen pH was alike statistically in 3 groups and at various time intervals. The mean ammonia-N concentration was significantly (p<0.01) more in group II and III as compared to group I. The mean TVFA concentration (mM/100 ml SRL) were 6.46, 7.84 and 8.47 in 3 groups respectively and different statistically (p<0.01). Results revealed no significant difference in the activities of carboxy methyl cellulase, urease or protease at both the time of sampling (0 h and 4 h) in all the 3 groups of animals.