• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.140-143
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• 2001

A study has been made on the recovery of nitric acid and valuable metals such as Cu, Sn, Pb from the spent nitric etching solutions. The nitric acid was extracted effectively by TBP but the heavy metals such as Fe, Cu, Sn, Pb were not extracted by TBP from the spent nitric etching solutions. From the experimental results, 95% of nitric acid in spent etching solution was extracted at O:A ratio of 3:1 with five stage by 60% TBP and 98% of nitric acid was stripped from the loaded organic phase at O:A ratio of 1:1 with four stages by distilled water. After extracting nitric acid, Cu was recovered as a metal by electrowinning effectively and Sn was successfully removed by precipitation method by adjusting the pH of raffinate solution. Finally, Pb was recovered by cementation with iron scrap at $65^{\circ}C$. Parameters controlling the cementation process, such as temperature, pH and the effect of the additives were investigated.

• Journal of Acupuncture Research
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• v.27 no.3
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• pp.65-73
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• 2010

Objectives : Recently, Pharmacopuncture therapy has been used for the treatment of inflammatory diseases such as rheumatoid arthritis. Especially, we have been interested in chemical mediators concerned with inflammation such as prostaglandin, nitric oxide. The purpose of this study is investigated that the effect of Ampelopsis Radix Pharmacopuncture solution in RAW 264.7 macrophages, performed several experimental items : those are Prostaglandin $E_2$, Nitric Oxide and Cyclooxygenase-2. Methods : The cytotoxicity of Ampelopsis Radix Pharmacopuncture solution in RAW 264.7 macrophages were measured by MTT assay. In order to observe cyclooxygenase-2 mRNA expression in lipopolysaccharide and interferon-gamma stimulated RAW 264.7 macrophages, RT-PCR was used. Prostaglandin $E_2$ production and Nitric Oxide production was measured by nitric oxide detection kit and Prostaglandin $E_2$ assay kit. Results : 1. The MTT assay demonstrated that cytotoxic effect of Ampelopsis Radix Pharmacopuncture solution in RAW 264.7 macrophages was not appeared. 2. Ampelopsis Radix Pharmacopuncture solution inhibited nitric oxide production in lipopolysaccharide and interferon-gamma stimulated RAW 264.7 macrophages. 3. Ampelopsis Radix Pharmacopuncture solution inhibited cyclooxygenase-2 mRNA expression in lipopolysaccharide and interferon-gamma stimulated RAW 264.7 macrophages. 4. Ampelopsis Radix Pharmacopuncture solution inhibited Prostaglandin $E_2$ production in lipopolysaccharide and interferon-gamma stimulated RAW 264.7 macrophages. Conclusions : On the basis of these results, It was shown that Ampelopsis Radix Pharmacopuncture solution was able to inhibit the production of $PGE_2$ and NO, as well as COX-2 mRNA expression. Our results may provide new mechanism by which Ampelopsis Radix Pharmacopuncture solution accounts for its beneficial effect on accelerating wound healing and anti-inflammation.

• Clean Technology
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• v.9 no.2
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• pp.57-61
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• 2003

A novel nitric acid-free desmut solution has been developed to remove smut, which is produced from a NaOH etching, on the surface of aluminum alloy metal in metal surface treatment processes. Comparing with the performance of 5% $HNO_3$ desmut solution, the mixed acid solution containing 2% $H_2O_2$, 0.5% HF, and 10% $H_2SO_4$ shows the same effect of smut removal for aluminum alloy samples of A16061 and A15052. To examine the surface alterations of the aluminum samples, in addition, the surface analysis is carried out with scanning electron microscopy (SEM) and electron probe microanalysis (EPMA).

• Journal of the Korean institute of surface engineering
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• v.49 no.3
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• pp.231-237
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• 2016

This article reports a new chemical bath for preparing a mirror-like surface of AZ31 Mg alloy. In order to find an appropriate chemical polishing solution, four different acidic solutions of sulphuric acid, nitric acid, acetic acid and a specially designed mixture of nitric acid and acetic acid were investigated in view of the changes in surface appearance, roughness and dissolution rate of AZ31 Mg alloy. The surface scales on AZ31 Mg alloy were readily removed by all the acidic solutions, but a reflective surface was produced only by etching in the specially designed solution, and only after a specific etching time. The surface roughness increased with etching time in sulphuric acid, nitric acid, and acetic acid, but it lowered after a specific etching time in the specially designed mixture of nitric acid and acetic acid. Dissolution rate of the alloy in the specially designed mixture of nitric acid and acetic acid appeared to be more than twice than that in separate nitric acid or acetic acid. In this work, we recommend the mirror-like surface of AZ31 Mg alloy obtained by polishing for an optimum time in a mixture of nitric acid and acetic acid for following surface finishings, chemical conversion coating, electroplating, electrophoretic painting and anodizing treatment.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.11
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• pp.1624-1628
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• 2015

Rigorously standardized laboratory protocols are essential for meaningful comparison of data from multiple sites. Considering that interactions of minerals with organic matrices may vary depending on the material nature, there could be peculiar demands for each material with respect to digestion procedure. Acid digestion procedures were evaluated using different nitric to perchloric acid ratios and one- or two-step digestion to estimate the concentration of calcium, phosphorus, magnesium, and zinc in samples of carcass, bone, excreta, concentrate, forage, and feces. Six procedures were evaluated: ratio of nitric to perchloric acid at 2:1, 3:1, and 4:1 v/v in a one- or two-step digestion. There were no direct or interaction effects (p>0.01) of nitric to perchloric acid ratio or number of digestion steps on magnesium and zinc contents. Calcium and phosphorus contents presented a significant (p<0.01) interaction between sample type and nitric to perchloric acid ratio. Digestion solution of 2:1 v/v provided greater (p<0.01) recovery of calcium and phosphorus from bone samples than 3:1 and 4:1 v/v ratio. Different acid ratios did not affect (p>0.01) calcium or phosphorus contents in carcass, excreta, concentrate, forage, and feces. Number of digestion steps did not affect mineral content (p>0.01). Estimated concentration of calcium, phosphorus, magnesium, and zinc in carcass, excreta, concentrated, forage, and feces samples can be performed using digestion solution of nitric to perchloric acid 4:1 v/v in a one-step digestion. However, samples of bones demand a stronger digestion solution to analyze the mineral contents, which is represented by an increased proportion of perchloric acid, being recommended a digestion solution of nitric to perchloric acid 2:1 v/v in a one-step digestion.

• Journal of Pharmacopuncture
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• v.10 no.2 s.23
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• pp.25-30
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• 2007

Objectives : Free radical metabolism seems to occupy a remarkably common position in the mechanisms of aging and aging related disease. Oxidative damage to DNA, lipids. proteins and other molecules may contribute to the development of cancer, cardiovascular disease and possibly neurodegenerative disease. This study was designed to find out whether Carthami Flos Herbal-Acupuncture Solution can scavenge Nitric Oxide(NO) or not. SNAP is NO generator. NO concentration was estimated after 2,6, 12 and 24 hrs in no treatment group, after treatment with Vit. C or 1, 10, 100${\mu}$g/m1 of Carthami Flos Herbal-Acupuncture Solution. There was no significant scavenging effect of Carthami Flos Herbal-Acupuncture Solutionon NO after 2 hrs. But there was a significant scavenging effect of Cafhami Flos Herbal-Acupuncture Solution on NO in 10${\mu}$/m1 group after 6hrs. And there was a significant scavenging effect of carthami Flos Herbal-Acupuncture Solution on NO in 1, 10${\mu}$g/ml group after 12, 24 hrs. These results suggest that Carhami Flos Herbal-Acupuncture Solution has scavenging effect on NO. This study shows that Carthami Flos Herbal-Acupuncture Solution can be used for aging related disease and further studies are required to investigate the antioxidative effects of it.

• Resources Recycling
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• v.18 no.5
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• pp.44-51
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• 2009

Fundamental study has been made on the recovery of copper from the electronic scrap by hydrometallurgical process. Nitric acid was used as a leaching agent to dissolve the metals such as Cu, Sn, Pb, Fe etc. from the crushed electronic scraps. TBP was employed to extract nitric acid from the strong nitric acid leaching solutions and to reclaim nitric acid. From the experimental results, Cu was effectively leached by 3.0-4.0 M nitric acid. And 95% of nitric acid in the leaching solution was extracted by 60% TBP, and 98% of nitric acid was stripped from the loaded organic phase by distilled water and it was possible to reuse as a leaching agent.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.32 no.3
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• pp.13-22
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• 2019

Objectives : Armeniacae semen is the seed of Prunus armenica L. var. ansu MAXIM, and this is classified into Rosaceae. Armeniacae semen has been used for centuries in traditional oriental medicine for the treatment of pain and inflammatory diseases. Amygdalin is the major compound of Armeniacae semen, and it is now being used for the treatment of pain and cancer. Methods : In the present study, we compared the effects of an aqueous extract of Armeniacae semen and a solution of amygdalin extracted from Armeniacae semen on lipopolysaccharide(LPS)-stimulated prostaglandin E2 synthesis and nitric oxide production in mouse BV-2 microglial cells. For this study, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT) assay, reverse transcription-polymerase chain reaction(RT-PCR), prostaglandin E2 immunoassay and nitric oxide detection were performed on mouse BV-2 microglial cells. Results : In the present study, an aqueous extract of Armeniacae semen and an amygdalin solution extracted from Armeniacae semen suppressed prostaglandin E2 synthesis and nitric oxide production by inhibiting the LPS-induced enhancement of cyclooxygenase-2(COX-2) mRNA and the inducible nitric oxide synthase mRNA in mouse BV-2 cells. For the cyclooxygenase-1(COX-1) expression, an aqueous extract of Armeniacae semen showed a more potent suppression effect compared to the amygdalin solution. However, the amygdalin solution more potently suppressed the LPS-induced COX-2 mRNA expression compared to the aqueous extract of Armeniacae semen. Conclusions : As a result, aqueous extract of Armeniacae semen and amygdalin exert anti-inflammatory and analgesic effects.

• Carbon letters
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• v.9 no.1
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• pp.8-16
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• 2008

Oxidized activated carbons were prepared by reacting steam-activated carbon developed from pecan shells with nitric acid of varying strength (15, 30, 45 and 60%). The textural properties and the chemistry of the surface of the non-oxidized and of the oxidized carbons were determined from nitrogen adsorption and base neutralization capacities. The uptake of Pb(II) and Cd(II) from aqueous solution by these carbons was determined by kinetic and equilibrium experiments as well as by the column method. Treatment with nitric acid brought about drastic decrease in surface area and remarkable increase in the pore size of the carbon with these changes depending on the strength of nitric acid. Nitric acid increased the surface acidity by developing new surface oxygen functional groups of acidic nature. $HNO_3$-oxidized carbons exhibited high adsorption capacities for Pb(II) and Cd(II). The adsorption of these ions increased with the decrease of the surface pH of the carbon and with the increase of the solution pH from 2.5 to 6 and 7. The amount adsorbed from lead and cadmium was also related to the amount of surface acidity, the pH of the point of zero charge and on some metal ion parameters. Cadmium and lead uptake by the investigated carbons followed pseudo-second order model and the equilibrium sorption data fitted Langmuir adsorption model.

• Resources Recycling
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• v.26 no.1
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• pp.51-58
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• 2017

The present study to develop a process for extracting nitric acid and gold from aqua regia leach solution using TBP(tributyl phosphate) was conducted. The pure aqua regia was used to investigate the extractive behavior of nitric acid depending on the concentration of extractant, concentration ratio of nitric and hydrochloric acid. The extraction rate of nitric acid and gold from the gold bearing aqua regia was also examined. The theoretical extraction number was verified by counter current using the number of operations and the phase ratio obtained from McCabe-Thiele diagram. Stripping experiments were carried out for continuous recovery of nitric acid and gold in loaded organic. Considering the effect of extraction acid and gold, the simulation showed that greater than 99.9% extraction of $103.0mg{\cdot}L^{-1}$ gold and 98.0% of $151.2g{\cdot}L^{-1}$ nitric acid could be attained in a two and three-stage counter-current extraction at an O/A phase ratio of 1:0.85. Distilled water and sodium thiosulfate were used as the nitric acid and gold stripping solution. The stripping rates were 99.5% and 92.0%, respectively. The study revealed that the recovery of nitric acid and gold from gold bearing aqua regia was a plausible approach through simultaneous extraction and continuous stripping of nitric acid and gold.