• Corrosion Science and Technology
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• v.16 no.2
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• pp.59-63
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• 2017

Chelating solutions can be damaged by strong acids during oil production. To design effective corrosion inhibitors and other alternatives for corrosion control, it is important to understand not only the behavior of the system under operating condition but also the kinetics of electrochemical reactions during the corrosion process. In this study, the electrochemical behaviors of P-110 steel in aqueous fluids based on ethylenediaminetetraacetic acid (EDTA) compounds under various temperatures and hydrodynamic regime conditions were assessed. Electrochemical measurements were conducted using rotating disc electrodes manufactured. Electrolytes were prepared using aqueous compounds of EDTA like diammonium salt, disodium salt, and tetrasodium salt. Potentiodynamic polarization, electrochemical impedance, and mass loss tests were performed in order to assess the corrosion kinetic in electrolytes. Hydrodynamic effects were observed only in the cathodic polarization curve. This proves that hydrodynamic regime plays an important role in the corrosion of steel mainly in disodium and diammonium EDTA solutions. Two cathodic reactions controlled the corrosion process. However, oxygen level and pH of the electrolyte played the most important role in metal corrosion. Corrosion rates in those fluids were decreased drastically when oxygen concentration was reduced.

• Advances in materials Research
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• v.2 no.1
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• pp.51-64
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• 2013

Enantioselective macromer of trimesic acid was prepared using S(-) menthol with trimesoyl chloride on polyimide (PI) ultrafiltration membrane. The chemical composition of macromer as well as polyimide ultrafiltration membrane was determined by ATR-FTIR Spectroscopy. The optical resolution of chiral alcohols was performed in pressure driven process. The effect of monomer solutions concentration, effect of air-drying time of S(-) menthol solution, effect of reaction time, effect of operating pressure, effect of feed concentration of racemate on the performance of macromer was studied. The synthesised material exhibits separation of chiral alcohols (menthol ~23% and sobrelol ~21%).

• Food Science and Preservation
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• v.15 no.5
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• pp.719-724
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• 2008

The overall objectives of this study were to examine the potential of sturgeon as an intermediate moisture food (IMF) by measurement of nutritional components, such as minerals, fatty acids, amino acids, and water activity. Chemical compositions were as follows:moisture 73.2%, crude protein 19.9%, crude lipid 5.7%, ash 1.1%, and carbohydrate 0.1%. Minerals were K 317.70, P 259.88, and Mg 29.78 mg/100 g. Fatty acids detected were oleic acid (40.46% of total), palmitic acid (23.27%), and linoleic acid (15.35%). In addition, sturgeon was very rich in glutamic acid (1,189.71 mg/100 g) and deficient in serine (55.12 mg/100 g). Moisture content and water activity of sturgeon dried at $40^{\circ}C$ after soaking in different concentrationsof sugar and salt solutions were 15.12-16.24% and 0.68-0.79, respectively. Sensory evaluation of sturgeon soaked in different concentrations of sugar and salt solutions indicated that sturgeon soaked in 3.0% (w/v) sugar and salt solution scored highest.

• Clean Technology
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• v.3 no.2
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• pp.74-86
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• 1997

Recently the treatment of industrial wastes by membrane processes has drawn much attention due to increasing demands for clean technology. In the process investigated in this study, metal species in the acidic wastes are precipitated as metal hydroxide forms in a neutralization tank, and acid and base solutions are regenerated by water-splitting electrodialysis(WSED) to be reused in the process. Material balances of the processes for treating pickle liquor and mixed wastewater were calculated to explain conceptual design of the process. Experiments for neutralization precipitation with KOH and NaOH for mixed wastewater were carried out to precipitate metal hydroxide and to recover salt solution as supernatant. Also WSED of the salt solutions producing acid and base was tested in 2 or 3 compartment stacks using KCl and NaCl to investigate the effects of stack configurations on the WSED performance.

• Journal of Powder Materials
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• v.20 no.3
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• pp.197-202
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• 2013

A novel route to prepare Nd-Fe-B magnetic particles by utilizing both spray drying and reduction/diffusion processes was investigated in this study. Precursors were prepared by spray drying method using the aqueous solutions containing Nd salt, Fe salt and boric acid with stoichiometric ratios. Precursor particles could be obtained with various sizes from 2 to $10{\mu}m$ by controlling concentrations of the solutions and the average size of $2{\mu}m$ of precursors were selected for further steps. After heat treatment of precursors in air, Nd and Fe oxides were formed through desalting procedure, followed by reduction processes in Hydrogen ($H_2$) atmosphere and with Calcium (Ca) granules in Argon (Ar) successively. Moreover, diffusion between Nd and Fe occurred during Ca reduction and $Nd_2Fe_{14}B$ particles were formed. With Ca amount added to particles after $H_2$ reduction, intrinsic coercivity was changed from 1 to 10 kOe. In order to remove and leach CaO and residual Ca, de-ionized water and dilute acid were used. Acidic solutions were more effective to eliminate impurities, but Fe and Nd were dissolved out from the particles. Finally, $Nd_2Fe_{14}B$ magnetic particles were synthesized after washing in de-ionized water with a mean size of $2{\mu}m$ and their maximum energy product showed 9.23 MGOe.

• Korean Journal of Food Science and Technology
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• v.52 no.1
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• pp.19-25
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• 2020

Turmeric pigments have been used as coloring agents and functional ingredients. In this study, the extraction property and chemical stability of the pigments were evaluated in several preservative solutions containing NaCl, sucrose, and acetic acid. After 72 h of infusion, the protein and polyphenol levels and antioxidant activity of the turmeric extracts in the solutions were less pronounced than those in water. Acetic acid (12%) was more efficient at extracting curcuminoids from turmeric than water, NaCl (20%), or sucrose (25%). Curcumin was highly abundant in all solutions. The relative yield of bisdemethoxycurcumin (BMC) was the highest in acetic acid, whereas that of curcumin was highest in NaCl and sucrose solutions. Curcuminoids were relatively stable in sucrose and acetic acid; among them, BMC had the highest stability. The stability of the curcuminoid solution decreased based on the increase in NaCl content, whereas it was significantly enhanced in sucrose and acetic acid. The observations from this study can be applied to the processing and storage of turmeric-derived products in these preservative agents.

• Korean Journal of Agricultural Science
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• v.8 no.2
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• pp.231-237
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• 1981

In order to obtain the basical data for utilization of protein in hazel nut, protein was extracted from defatted hazel nut meal with salt solutions and alkaline solutions, and precipitated by adjusting pH of extract to 5.5 or addition of organic solvents. Amino acid composition of the isolated protein and defatted hazel nut meal were analyzed, protein isolates were identified by polyacrylamide gel electrophoresis. The results summarized were as follows. 1. Defatted hazel nut showed highly nutritional value as the content of 'protein was 53.6%. 2. Extractabilities of salt-soluble protein treated with 2.5M $MgCl_2$, and 1M NaCl(pH 11.0) were 53.0%, 31.5%, respectively 3. Protein in hazel nut were contained 53% of salt-soluble globulin, 14% of water-soluble albumin, 29.5% of glutelin based on solubility. 4. At pH 5.5, 85% of the extracted protein was precipitated, and about 90% of the extracted protein was separated by addition of organic solvents such as acetone and ethanol at 60-70% concentration. 5. Proteins extracted from defatted hazel nut with water and 0.027N NaOH showed 3 and 6 hands by polyacrylamide gel electrophoresis, respectively. 6. Amino acids of defatted hazel nut and protein isolate were chiefly composed of glutamic acid, arginine and aspartic acid.

• Textile Coloration and Finishing
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• v.22 no.2
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• pp.88-93
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• 2010

Using extracted sepia melanin powder by repeated treatments with aqueous sodium hydroxide and acetic acid solutions, vat dyeing of wool and cotton fabrics was carried out under various dyeing conditions including concentration of melanin, alkali, reducing agent and salt, as well as dyeing time and temperature. A K/S of 25.3 for wool fabrics was obtained at the optimal dyeing condition with 9% owf melanin, 0.5g/L NaOH and 56g/L $Na_2S_2O_4$ without salt at $80^{\circ}C$ for 90minutes. The vat dyeing of sepia melanin was applicable to both cotton and wool fabrics but the wool showed higher dyeability. The color fastness properties of the dyed wool and cotton fabrics were excellent to washing, rubbing and light irradiation.

• Corrosion Science and Technology
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• v.7 no.1
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• pp.13-15
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• 2008

Aiming at the corrosion circumstances and corrosion prevention needs of downhole oil tubes, series protective coatings for downhole oil tubes have been developed in the authors' laboratory, including a baked type coating YG-01 and an air curing type coating YG-03, etc. The performance investigation of the coatings has been done for testing their corrosion resistance, mainly including salt fog test, immersion test in oil-field waste water and various acid solutions, high temperature and high pressure test in alkali solution or $H_2S/CO_2$ environment, as well as some other performances. The investigation results show that oil tube anti-corrosion coatings developed here can endure over 4000 hrs salt fog test, over 1000 hrs immersion in various acid solutions at room temperature and in boiling oil-field waste water. In addition, the coatings can keep intact after experiencing test in alkali solution under 70 MPa pressure at $150^{\circ}C$ for 24 hrs, and in simulative sour gas environment under the total pressure of 32 MPa ($P_{H_{2}S}=3.2MPa$, $P_{CO_{2}}=3.2MPa$) at $90^{\circ}C$ for 168 hrs, which show that the coatings can be used for corrosion prevention in downhole environments with specific high temperature and high pressure, such as sour gas wells. The other testing results show the oil tube protective coatings have excellent comprehensive performance.

• Korean Journal of Community Nutrition
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• v.15 no.5
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• pp.670-678
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• 2010

Recognition thresholds for NaCl, sucrose, citric acid, and caffeine, as well as the pleasant concentration of NaCl were assessed in 176 males and 312 females aged 50-88 years. Furthermore, relationships among taste sensitivities, taste preferences, and lifestyles were examined. The taste solutions were presented one after the other in ascending order using the sip-and-spit method. For the recognition thresholds of the 4 basic tastes, women perceived significantly lower concentrations than the men. However, the pleasant concentration of NaCl did not show a gender difference. Sensitivities for the 4 basic tastes did not decrease with age in the men, but they did significantly decrease with age for the women, especially for those above 70 years. For men, regular exercise was positively correlated with sensitivities for sour taste and bitter taste, and physical activity was negatively correlated with the pleasant concentrations of NaCl. For women, who had more physical activity, sensitivities for sweet taste and sour taste were lower compared to the others. This study indicates that the sensitivities for 4 basic tastes in water diminished with age, but pleasant salt concentration did not change with age. Further research on pleasant NaCl concentration is required to determine factors affecting salt preference, in order to decrease salt intake in the elderly.