• Geomechanics and Engineering
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• v.16 no.4
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• pp.375-384
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• 2018

Unconfined compressive strength (UCS) of high plasticity clayey soil mixed with 5 and 10 % of Portland cement and four chemical agents such as sodium hexametaphosphate, aluminum sulfate, sodium carbonate, and sodium silicate with 0, 5, 10, and 20% concentrations was comparatively evaluated. The individual and combined effects of the cement and chemical agents on the UCS of the soil mixture were investigated. The strength of the soil-cement mixture generally increases with increasing the cement content. However, if the chemical agent is added to the mixture, the strength of the cement-chemical agent-soil mixture tends to vary depending on the type and the amount of the chemical agent. At low concentrations of 5% of aluminum sulfate and 5% and 10% of sodium carbonate, the average UCS of the cement-chemical agent-soil mixture slightly increased compared to pure clay due to increasing the flocculation of the clay in the mixture. However, at high concentrations (20%) of all chemical agents, the UCS significantly decreased compared to the pure clay and clay-cement mixtures. In the case of high cement content, the rate of UCS reduction is the highest among all cement-chemical agent-soil mixtures, which is more than three times higher in comparison to the soil-chemical agent mixtures without cement. Therefore, in the mixture with high cement (> 10%), the reduction of the USC is very sensitive when the chemical agent is added.

• Korean Journal of Food Science and Technology
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• v.17 no.1
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• pp.5-7
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• 1985

Effect of phosphate (sodium polyphosphate 85%, sodium hexametaphosphate 7% and potassium phosphate 7%) on gelatinization of nonwaxy and waxy rice starches was investigated with X-ray diffractometry. The minimum moisture content for the gelatinization of nonwaxy starches was lowered in the presence of phosphate. The minimum temperature for the gelatinization of 5% starch suspensions was not altered by phosphate. However, the degree of gelatinigation of rice starches at the same temperature was higher in the presence of phosphate, except waxy rice starch.

• Journal of Sericultural and Entomological Science
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• v.36 no.1
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• pp.37-43
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• 1994

The effects of some sodium phosphates as auxiliary agents were studied on the blockade of hardness for silk degumming. In this work, four kinds of sodium phosphates were tested and the results were obtained through masking effects of metallic ions, difference of pH value and boil-off ratio. The degumming of calcium ingredient was analyzed by means of atomic absorption spectrophotometer and degumming test of cocoon shell was performed in the presence of calcium ingredient and sodium phosphates added to soap solution. In the view of the effects of sodium phosphates on calcium hardness, tetrasodium pyrophosphate(TSPP) and sodium phosphate dibasic(SPD) masked calcium ions more than sodium phosphate monobasic(SPM) and sodium hexametaphosphate(SHP). SHP and TSPP have excellent abilities of masking ferrous ions. The pH values of TSPP solution is higher than others, but lower than soap solution. The pH values were differently measured one another among the sodium phosphates but the boil-off ratio was increased in case of sodium phosphate with high pH value.

• Economic and Environmental Geology
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• v.45 no.2
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• pp.121-135
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• 2012

Soil dispersion and heavy metal leaching with two heavy metal-contaminated soils were studied to derive the optimal dispersion condition in the course of developing the remedial technology using magnetic separation. The dispersion solutions of pyrophosphate, hexametaphosphate, orthophosphate and sodium dodecylsulfate (SDS) at 1 - 200 mM and the pH of solutions was adjusted to be 9 - 12 with NaOH. The clay content of suspension as an indicator of dispersion rate and the heavy metal concentration of the solution were tested at the different pHs and concentrations of the dispersion solution during the experiment. The dispersion rate increased with increasing the pH and dispersion agent concentration of the solution. The dispersion efficiency of the agents showed as follows: pyrophosphate > hexametaphosphate > SDS > orthophosphate. Arsenic leaching was sharply increased at 50 mM of phosphates and 100 mM of SDS. The adsorption of $OH^-$, phosphates and dodecysulfate on the surface of Fe- and Mn-oxides and soil organic matter and the broken edge of clay mineral might decrease the surface charge and might increase the repulsion force among soil particles. The competition between arsenic and $OH^-$, phosphates and dodecylsulfate for the adsorption site of soil particles might induce the arsenic leaching. The dispersion and heavy metal leaching data indicate that pH 11 and 10 mM pyrophosphate is the optimum dispersion solution for maximizing dispersion and minimizing heavy metal leaching.

• Journal of the Korean Ceramic Society
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• v.38 no.7
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• pp.654-659
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• 2001

고령토 슬러리의 분산특성에 미치는 양이온성 polyethyleneimine 결합제의 영향을 고찰하였다. 분산제인 Sodium Hexametaphosphate (SHP)를 0.8 wt% 첨가한 경우와 첨가하지 않은 두 가지 슬러리 내에서 polyethyleneimine (PEI)의 첨가량에 따른 슬러리의 응집, 분산거동을 점도 및 제타전위 측정을 통해 평가하였다. 슬러리 내에 SHP 유무에 상관없이 PEI 농도가 0.02 wt%일 경우에는 응집, 0.6 wt%에서는 분산, 0.6 wt% 이상에서는 재응집되는 것으로 각각 나타났다. 슬러리가 응집-분산-재응집과정을 거치는 동안 점토입자의 제타전위는 항상 일정한 값을 유지하였다. 또한 입자표면의 PEI의 흡착량은 SHP를 첨가한 슬러리의 경우가 크게 나타났으며, 분산성은 상대적으로 더 향상됨을 알 수 있었다.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.32-33
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• 2021

The corrosion of the embedded steel rebars and the consequent deterioration of the reinforced concrete structure has become a challenging concern to the construction industries for the fiscal deficit. However, corrosion inhibitors are potential and being widely used for corrosion mitigation to solve such problems. This study has been focused on the mixed type of corrosion inhibitor where one component of the corrosion inhibitor is organic and another one is inorganic material. 0.1 (M) triethanolamine (TEA) and 0.01 (M) sodium hexametaphosphate (SHMP) have been mixed in distilled water to produce the mixed inhibitor. Studies of the steel rebar corrosion in chloride contaminated (3.5 wt.% NaCl) concrete pore (CCCP) solution has been conducted using different concentrations of corrosion inhibitor. Electrochemical impedance spectroscopy (EIS) method is involved to understand the corrosion behaviour of the steel rebars at different exposure durations.

• Korean Journal of Food Science and Technology
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• v.11 no.2
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• pp.112-117
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• 1979

By using the existing caustic refining system with a minimum modification and by using a combination of various emulsifiers(0.2 % sodium hexametaphosphate. 0.05 % sodium lauryl sulfate and 0.001 % dioctyl sodium sulfosuccinate), a new economical dewaxing process for sunflower seed oil was developed in order to reduce the cost of the dewaxing process. The results indicate that the waxes can be removed satisfactorily from the sunflower seed oil by emulsifying. batchwise or continuously, the oil with the aqueous surfactant solution, followed by centrifugation at ambient temperatures $(16{\sim}27^{\circ}C)$. Dewaxing loss for the batch process was satisfactory for both low wax-and high wax-crude oil, whereas dewaxing loss for the continuous process needs to be improved. The results indicate that initial level of wax content (low wax vs. high wax) did not affect the loss for batch process (0.82 % vs. 0.62 %), but affected the loss for continuous processes, regardless of the type of mixing mode (2.28 % and 5.68 % for low wax-and high wax-oil, respectively). It was also noted that the type of mixing mode (centactor vs. static mixer) for the continuous process affected the loss, regardless of the wax content (5.2 % and 2.8 % for contactor and static mixer, respectively).

• Korean Journal of Food Science and Technology
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• v.17 no.6
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• pp.421-425
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• 1985

The changes of pectic substances during baking at $175{\sim}180^{\circ}C$ for 30 minutes and polygalacturonase activities of three sweet potato cultivars on textural properties were investigated. The three different types of sweet potato cultivars were the dry type (Wonki), the intermediate type (Shinmi), and the moist type (Chunmi). The moisture content, alcohol insoluble solid content, composition of pectic substances and hardness were determined before and after baking. It was found that HCl-soluble pectin was significantly changed into water soluble and sodium hexametaphosphate soluble pectin by baking. The dry type, Wonki showed the lowest moisture content, but the highest alcohol insoluble solid content and hardness. Wonki, whose polygalacturonase activity was the highest, had the highest HCl-soluble pectin content after backing.

• Journal of the East Asian Society of Dietary Life
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• v.14 no.6
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• pp.582-590
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• 2004

The purpose of this study was to investigate the effect of maesil(Prunus mume) on Dongchimi fermentation. Dongchimi with 0, 2, 4 and 6%(w/v) maesil was fermented at 10℃ for 45 days. The pH of Dongchimi decreased slowly in all samples during fermentation. Total acidity of Dongchimi increased gradually during fermentation and total acidity of Dongchimi with maesil was higher than that of control. Redox potentials decreased until 30 days of fermentation but increased thereafter. Reducing sugar content increased in the initial stage of the fermentation periods, and then it decreased gradually, the reducing sugar content of Dongchimi with maesil was higher than that of control. The content of total vitamin C was much higher in Dongchimi with maesil. In color measurement, lightness value decreased gradually, redness and yellowness values increased gradually during fermentation but decreased thereafter. The content of hot water soluble pectin(HWSP) decreased as the fermentation proceeded but the content of hydrochloric acid soluble pectin(HCISP) and sodium hexametaphosphate soluble pectin(NaSP) increased.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.6
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• pp.551-558
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• 1991

We investigated the physicochemical and functinal properties of rapeseed(Brassica napus var. Youngsan) protein prepared by combining various soluvent and purification procedures, such as ultrafiltration (UF) concentration and acid-washin. The lightness value(YCIE) of each protein was greadully improved and its hydrophobicity increased by the degree of purification. The analysis of each protein by sodium dodecyl sulfate-plyacrylamide gel electrophoresis (SDS-PAGE) had nine bands revealed without difference, the considerable portion of which were of $1.96~1.59{\times}10^4$ dalton molecular weight. The content of amino acid increased a little more in the other processed proteins than in the control, and decreased considerably in the proteins extracted by the mixed solvent of 1% sodium hexametaphosphate(SHMP) and 0.25M ethlene diamine tetraacetic acid (EDTA). The better proteins were purified, the lower the kinematic viscosities were in their values. The water absorption and foaming properties were scarcely different according to the processes. The oil absorption and the emulsion activity index normally increased according to the degree of purification. The properties of heat coagulation revealed high values only in the proteins processed by EDTA while they showed considerably low values the other proteins.