• Analytical Science and Technology
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• v.12 no.3
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• pp.230-234
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• 1999

Barium titanyl oxalates (BTO) has been homogeneously prepared by thermal decomposition of dimethyl oxalate (DMO) in hydrochloric solution containing $Ba^{2+}$ and $Ti^{4+}$. Particles of BTO settled on the bottom of the beaker were collected at the aging time of 120 min using hydroxy propyl cellulose (HPC) as a dispersant. The reaction temperature, the concentration ratio of $[DMO]_0/([Ba^{2+}]_0+[Ti^{4+}]_0)$ and the existence of HPC were found to influence on morphologies of BTO, chemical yields and characteristics of barium titanates formed from their precursors.

• Journal of Pharmaceutical Investigation
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• v.24 no.3
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• pp.109-113
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• 1994

Effects of various formulation factors using $L_8$ orthogonal arrays with the stability of doxorubicin hydrochloride injections(DHls) were investigated. The degradation of DHI may be occured by pH, temperature, light and metal ions. It is known that DHI should be stored on refrigerated condition of $4{\sim}8^{\circ}C$ because of its unstability on the room temperature. The employed factors were sodium chloride as isotonic solution, sodium bisulfite or sodium pyrosulfite as an antioxidant, disodium edetate as a chelating agent, methyl parahydroxybenzoate as a dissolution time shortening agent, and hydrochloric acid or citric acid as a pH adjusting agent at $22^{\circ}C$. From the results of $L_8$ orthogonal arrays, an optimal formula, including sodium chloride, disodium edetate, sodium bisulfite and hydrochloric acid, was obtained and the shelf-life of the formula was determined as 560 days approximately.

• Textile Coloration and Finishing
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• v.27 no.4
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• pp.229-244
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• 2015

The effects of synthesis conditions on characteristics of the calcium-azo complex pigment, C.I. Pigment Red 57:1, were studied. It was mainly considered that the industrially required synthesis conditions for lowering electrical conductivity of the pigment solution keeping pigment quality such as particle size and color characteristics. Three parameters were chosen as control factors during the synthesis. The first was the amount of hydrochloric acid added to transform sodium nitrite into nitrous acid. The second was the amount of calcium chloride added to insolubilize the synthesized azo dye. The final factor was pH control during the coupling reaction. The electrical conductivity and pigment aggregate particle size were dependent on the amount of hydrochloric acid and calcium chloride. Higher HCl concentration gave brighter yellowish-red color because of smaller particle aggregate size and narrower size distribution. Amount of charged ions in the synthesis process might affect the "lake" formation resulting different particle aggregate size and color shade.

• Resources Recycling
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• v.20 no.2
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• pp.60-66
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• 2011

Solvent extraction experiments were carried out to recover and separate Ru(III) from aqueous hydrochloric acid media using TBP and Cyanex923. The efficiency of the extraction was studied under various experimental conditions, such as concentration of HCl and NaCl, concentration of extractant in the organic phase and temperature. The extraction behavior of metal impurities, such as Pt, Bi, Sn, Fe, Pb and Cu in mixed solutions was examined. From the experimental studies, it was found that the Cyanex923 resulted in higher extraction percentage of Ru than TBP. However TBP was more effective for the separation of Ru and Pt, Bi, Sn in mixed solutions than Cyanex923.

• Analytical Science and Technology
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• v.12 no.5
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• pp.382-386
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• 1999

Spherical particles of barium titanyl oxalate(BTO) were homogeneously precipitated by thermal decomposition of dimethyl oxalate in hydrochloric mixture solutions of water and ethanol. The experimental parameters such as composition of the mixture solvents. the eoncentration of hydrochloric acid and reaction temperature had the paramount effect on the size of panicles collected from the bottom of the reaction vessel at the aging time of 120 min and the composition of BTO. Stoichiometric BTO powders were obtained under certain conditions as relatively low alcohol content in the mixtures, high chloride concentration and high temperature, Monosized, submicrometer, but titanium excess particles were obtained under certain reverse conditions.

• Journal of Chest Surgery
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• v.17 no.1
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• pp.101-109
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• 1984

The influences of acute respiratory and metabolic acid-base disturbances on the carotid, renal and coronary blood flow were measured in dogs. Respiratory acidosis was induced by artificial respiration with 8% CO2 -02 gas mixture and respiratory alkalosis was induced by hyperventilation under the control of respirator. Metabolic acidosis and metabolic alkalosis were induced by intravenous infusion of 0.3N hydrochloric acid and 0.6M sodium bicarbonate solution. To observe the effect of hyperkalemia, isotonic potassium chloride solution was infused. CVI electromagnetic flowmeter probes were placed on the left common carotid artery, left renal artery and left circumflex coronary artery. Each flow was recorded on polygraph. 1. The carotid blood flow showed rapid showed rapid and marked increase in acute respiratory acidosis. Even in the cases when arterial blood pressure was lowered during the state of respiratory acidosis, carotid blood flow increased. By the infusion of hydrochloric acid, carotid blood flow increased slowly and returned to the previous label after discontinuation of the infusion. Carotid blood flow also increased by the infusion of large amount of sodium bicarbonate, but it might be the combined effect of expansion of extracellular fluid and compensatory elevation of carbon dioxide tension. 2.The renal blood flow remained unchanged during the acute acid-base disturbances, suggesting effective autoregulation. Renal blood flow, however, increased very slowly when the infusion of potassium chloride continued for a long period. 3.Although less marked than the carotid blood flow, the coronary blood flow increased in the acute respiratory and metabolic acidosis. In asphyxiated condition, coronary blood flow increased most markedly and this might be the combined effect of hypoxia, hypercapnea, and lowering of pH. In summary, the carotid blowflow showed more marked change in the acute respiratory and metabolic acidosis than the renal and coronary blood flow. Respiratory and metabolic components of acid-base disturbances may influence the local blood flow concomitantly, there being more differences in the individual responses, but respiratory component manifested more rapid and marked effect than metabolic component.

• Applied Chemistry for Engineering
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• v.3 no.4
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• pp.686-693
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• 1992

In order to investigate the mechanism of dissolutin of nickel from a matte composed essentially of heazlewoodite and ferronickel, the leaching in an aqueous solution of hydrochloric was carried out at $50-90^{\circ}C$, 0.5-3.ON HCl, and with the particle sizes between $100-160{\mu}m$ and $400-500{\mu}m$. The leaching rate of heazlewoodite was much rapider than that of ferronickel, and the two components were simultaneously dissolved with different reaction rates. Within the experimental range, NiS, an intermediate, was not formed. However a possibility to form a thin layer of NiS on particle surface upon saturating the reaction mixture with $H_2S$ was not excluded. At the initial stage, the activation energy was about 10 kcal/g mol. The reaction occurred at the particle surface, and consequently the particle size decreased with time. The rate of dissoultion for nickel was linearly proportional to the concentration of HCl up to 1.0N.

• Resources Recycling
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• v.18 no.6
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• pp.38-45
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• 2009

Dissolution characteristics of magnesite ore in hydrochloric acid solution and removal of impurity were investigated. The dissolution yield increased with increasing temperature and with decreasing particle size. The optimum conditions for dissolution were found to be reaction period of 120 min, reaction temperature of $80^{\circ}C$ and mean particle size of 100. Under optimal dissolution condition the extraction of Mg was 98%. It was found that most of Si and Al exist in the residue, and they can be removed by filtering. Dissolved impurity ions were precipitated as metal hydroxides by pH adjustment. Polymers were used as coagulants for metal hydroxides and the suitable coagulant dosage was 1mg/100ml of non-ionic polymer.

• Applied Chemistry for Engineering
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• v.30 no.1
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• pp.34-38
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• 2019

A cement industrial by-product was used as a Ca source for the carbonation process. It was confirmed that the most of cement industrial by-products was composed of CaO and KCl through ICP and XRD analyses. The optimal extractant type and concentration was 1.5 M of hydrochloric acid, and the solid/liquid ratio was 0.1 g/mL. It was assumed that the cation extraction efficiency was dependent of the pair ions and their binding formation and also the solubility from extraction efficiency results by varing extractants. After extraction process, it was also confirmed that the cation could be selectively separated from the solution with respect to the kind of additives and the injection order. When NaOH was injected into the solution to control pH values ranging from 9.5 and 13, impurities and $Ca(OH)_2$ were precipitated, whereas the separated K ion was precipitated in the form of KCl under the injected $C_2H_5OH$.

• Archives of Pharmacal Research
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• v.7 no.1
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• pp.47-52
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• 1984

Four polymorphic forms (I, II, III and IV) of hydrochlorothiazide have been characterized on the basis of x-ray diffractometry and differential thermal analysis. Form I was obtained by crystallization from N, N-dimethylformamide and Form II was crystallized from hot methanol. Form III was precipitated from sodium hydroxide aqueous solution by treatment with hydrochloric acid and Form IV was crystallized from 50% methanol. The metastable form I was a most stable form among four polymorphs, which was stable more than ten months at room temperature. The thermodynamic parameters such as heat of solution, enthalpy, entropy, free energy difference and transition temperature were determined by the measurement of intrinsic dissolution rate. The transition temperature and the heat of transition between the metastable Form I an Form II were determined to be $299.15^{\circ}$K and 5.03 Kcal/mole, respectively and free energy difference ($\delta$ F) was 302. 13 cal/mole. Diuretic action of these four polymorphic forms was also evaluated by monitoring the difference in urinary excretion of sodium, potassium and magnesium in rats.