• Journal of the Korea Concrete Institute
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• v.27 no.4
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• pp.443-450
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• 2015

This paper presents an investigation of the mechanical and microstructural properties of Class F fly ash based geopolymer containing sodium sulfate as an additive. Sodium sulfate was used as an chemical additive at the dosage levels of 0, 2, 4, and 6wt% of fly ash. Sodium hydroxide and sodium silicate solutions were used to activate fly ash. The compressive strengths of geopolymer pastes were measured at the age of 28 days. The microstructures of the geopolymer pastes were examined using XRD, MIP and SEM tests. The additions of 2wt% and 4wt% sodium sulfate produced geopolymers with high strength, while increasing the dosage of levels to 6% resulted in almost no changes in strength, comparing with the control geopolymer. The optimum increase in strength was obtained with the addition of 4wt% sodium sulfate. As the amount of sodium sulfate is increased, no additional crystalline phase was detected and no change of amorphous phase indicated despite the change in the strength development. The increase in the strength was due to the change of pore size distribution in samples. As addition of sodium sulfate altered the morphologies of reactive productions and Si/Al ratios of the reaction products, the strengths were thus affected. It was found that the strengths of geopolymer were larger for lower Si/Al ratios of reaction products formed in samples. The optimal amount of sodium sulfate in the fly ash based geopolymer helps to improve mechanical properties of the geopolymer, on the other hand, the high percentage of sodium sulfate could exist as an impurity in the geopolymer and hinder the geopolymer reaction.

• Korean Journal of Plant Resources
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• v.31 no.4
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• pp.275-282
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• 2018

Paeoniae Radix has been used as a traditional medicine for various diseases including hepatic disease. However, the inhibitory effect of Paeoniae Radix on intestinal inflammation has not been fully understood yet. The aim of this study was to evaluate the effect of Paeoniae Radix on colitis induced by dextran sulfate sodium in mice. To investigate the protective effects of Paeoniae Radix, the colitis mice were induced by drinking water containing 5% dextran sulfate sodium for 7 days. Mice were randomized into groups receiving Paeoniae Radix (100 mg/kg), sulfasalazine (150 mg/kg) as a positive control, or water as a negative control. We evaluated the effects of Paeoniae Radix on clinical signs induced by dextran sulfate sodium, measuring weight loss, colon length, and disease activity index. Additionally, to find a possible explanation for the anti-inflammatory effects of Paeoniae Radix, we evaluated the effects of Paeoniae Radix on the interleukin-6 and cyclooxygenase-2 levels in colitis tissue. The results indicated that mice treated with dextran sulfate sodium showed measurable clinical signs, including weight loss and reduced colon length. However, Paeoniae Radix treatment significantly improved the weight loss and disease activity index as clinical symptoms. Moreover, Paeoniae Radix inhibited the interleukin-6 and cyclooxygenase-2 expression levels in colon tissues treated with dextran sulfate sodium. Taken together, the findings of this study suggest that Paeoniae Radix may be useful for treating intestinal inflammation, including ulcerative colitis.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.5
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• pp.523-523
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• 2003

The change of interactions of anionic surfactants, sodium dodecyl sulfate(SDS) and sodium tetradecyl sulfate(575) in the presence of electrolytes, to the chitosan-based polyelectrolyte(sol＇n and gel phase) were studied. The chitosan gel used in this study were crosslinked with epichlorohydrin(ECH). Binding isotherms were determined by potentiometric technique using a surfactant ion selective solid-state electrode and the results were represented by using the sequence generating function(SGF) method. The results of binding isotherm were shown comparatively high cooperativity. The addition of electrolytes in the chitosan/SDS system resulted in a shift of the binding to higher free surfactant concentration because of screen effect by the electrolytes. Degree of binding of chitosan gel was higher than that of chitosan sol＇n. And also a conformational phase transition of the chitosan gel in the presence of electrolytes has been investigated.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.5
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• pp.524-532
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• 2003

The change of interactions of anionic surfactants, sodium dodecyl sulfate(SDS) and sodium tetradecyl sulfate(575) in the presence of electrolytes, to the chitosan-based polyelectrolyte(sol＇n and gel phase) were studied. The chitosan gel used in this study were crosslinked with epichlorohydrin(ECH). Binding isotherms were determined by potentiometric technique using a surfactant ion selective solid-state electrode and the results were represented by using the sequence generating function(SGF) method. The results of binding isotherm were shown comparatively high cooperativity. The addition of electrolytes in the chitosan/SDS system resulted in a shift of the binding to higher free surfactant concentration because of screen effect by the electrolytes. Degree of binding of chitosan gel was higher than that of chitosan sol＇n. And also a conformational phase transition of the chitosan gel in the presence of electrolytes has been investigated.

• Korean Journal of Poultry Science
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• v.37 no.2
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• pp.131-137
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• 2010

The present study has been performed to suggest a method to decrease the adverse effects of transportation on chicken meat quality. The groups were prepared as follows; Control group and three groups of treatments (sodium phosphate, sodium bicarbonate and magnesium sulfate). The chicken fed magnesium sulfate showed higher chicken meat quality compared to control and other treatment groups. Also, minor and severe PSE incidence of chicken breast was found at 88% in sodium phosphate group, 24% in sodium bicarbonate group and 56% in magnesium sulfate group. Control group showed 92% higher minor and severe PSE incidence of chicken breast compared to other groups. In control group, the external bruise of chicken showed 32% but 22, 24 and 44% in other treatment groups, respectively. Lightness ($L^*$) of chicken containing sodium phosphate treatment, sodium bicarbonate treatment and magnesium sulfate were 67.05, 66.27 and 65.89, while Lightness ($L^*$) of chicken containing control group was decreased of 67.88. In conclusion, dietary buffer material (sodium phosphate, sodium bicarbonate, magnesium sulfate) under heat stress decreased adverse effects including death, wound or abnormality of chickens.

• Advances in concrete construction
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• v.11 no.3
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• pp.183-192
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• 2021

Due to economic and environmental benefits, increasing the substitution ratio of ordinary cement by industry by-products like fly ash (FA) is one of the best approaches to reduce the impact of the concrete industry on the environment. However, as the substitution rate of FA increases, it will have an adverse impact on the performance of cement-based materials, so the actual substitution rate of FA is limited to around 10-30%. Therefore, in order to increase the early-age strength of high replacement (30-70%) low-calcium ultrafine FA blended cement paste, sodium sulfate and calcium sulfate dihydrate were used to improve the reactivity of FA. The results show that sodium sulfate has a significant enhancement effect on the strength of the composite pastes in the early and late ages, while calcium sulfate dihydrate has only a slight effect in the late ages. The addition of sodium sulfate in the cement-FA blended system can enhance the gain rate of non-evaporation water, and can decrease the Ca(OH)2 content. In addition, when the sulfate chemical activators are added, the ettringite content increases, and the surface of the FA is dissolved and hydrated.

• Journal of the Korea Concrete Institute
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• v.12 no.5
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• pp.141-151
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• 2000

Compressive strength, sulfate deterioration factor(SDF) and length change of 5 types of mortars immersed in sodium sulfate solution were observed. As the results of tests, it was found that the sulfate resistance of blended cement mortars were superior to that of portland cement mortars. Pore volume with diameter larger than 0.1 $\mu\textrm{m}$ of 5 types of pastes indicated that the micro-structures of blended cement pastes were denser, due to pozzolan reaction and latent hydraulic properties, than those of portland cement pastes. The XRD, ESEM, EDS and TG analyses demonstrated that the reactants such as ettringite and gypsum were significantly formed in portland cement pastes. Besides, compared with the $Ca(OH)_2$ content of ordinary portland cement pastes immersed in water and sodium sulfate solution, the $Ca(OH)_2$ contents of fly ash blended cement and ground granulated blast-furnace slag cement paste were about 58% and 28% in water, and 55% and 20% in sodium sulfate solution, respectively.

• Applied Chemistry for Engineering
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• v.7 no.6
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• pp.1105-1114
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• 1996

The characteristic and performance of ${\beta}-PbO_2$ layer electrodeposited on ${\alpha}-PbO_2/IrO_2-TiO_2/Ti$ substrate by adding sodium lauryl sulfate and $TiO_2$ powder in lead nitrate solution were investigated by using XRD, SEM, cyclic voltammograms, and macro-elctrolysis. Results of XRD analysis ascertain that ${\beta}-PbO_2$ layers electrodeposited in the presence of sodium lauryl sulfate and $TiO_2$, powder on ${\alpha}-PbO_2/IrO_2-TiO_2/Ti$ substrate have the same tetragonal structure as pure ${\beta}-PbO_2$ layers. The SEM results show that sodium lauryl sulfate tend to diminish crystal size of the deposited layer. The ${\beta}-PbO_2$ electrode electrodeposited in the presence of sodium lauryl sulfate and $TiO_2$ powder gives significantly improved oxygen overvoltage and durability for anodic oxidation in KOH and $HClO_4$ supporting electrolyte. Electrode performance and durability for the evolution of ozone in perchloric acid solution have been investigated by using ${\beta}-PbO_2$ electrodes electrodeposited on Titanium $madras^{(R)}$. It was ascertained that the $PbO_2$ electrode electrodeposited on ${\alpha}-PbO_2/IrO_2-TiO_2/Ti$ $madras^{(R)}$ by adding sodium lauryl sulfate and $TiO_2$ powder in $HClO_4$ supporting electrolyte had the highest current efficiency and durability.

• Journal of Veterinary Clinics
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• v.20 no.3
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• pp.351-356
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• 2003

The aim of this experiment was to study the calcium sulfate on early bone consolidation in distraction osteogenesis in the canine mandible. Twelve dogs were used and divided into control group (group A, 4 heads), sodium hyaluronate injection group (group B, 4 heads), mixture of calcium sulfate and sodium hyaluronate injection group (group C, 4 heads). Each group were subdivided into 3 weeks testing group (totally 6 heads) and 5 weeks testing group (totally 6 heads). Mandibular distraction was started at the 5th day after the mandibular osteotomy and continued for 10 days by 1 mm a day. After the distraction on the 10th day of mandibular distraction, 0.5 m1 saline in group A, 0.5 m1 sodium hyaluronate in group B, and 0.5 ml mixture of calcium sulfate and sodium hyaluronate in group C were each injected in mandibular distraction lesion. And X-ray examination, bone mineral density, and histopathological findings were examined. The radiological findings were the most radiopaque in group C, and the most radiolucent in group A in both 3 and 5 week testing group. The level of bone mineral density was also the highest in group C, and the lowest in group C in both 3 and 5 week testing group. The histopathological findings of new bone formation were the most remarkable in group C in both 3 and 5 week testing group. New bone formation of group A was not present in both 3 and 5 week testing group. In conclusion, calcium sulfate is a kind of material that can stimulate early bone formation and can shorten the duration of bone consolidation. And it can be effective in clinical usage.

• Journal of Industrial and Engineering Chemistry
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• v.67
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• pp.326-332
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• 2018

In this study,the result shows that polyvinyl alcohol-sodium alginate (PVA-SA) gel bead crosslinked with sodium sulfate are better among the different methods by comparing the relative mechanical strength, mechanical strength swelling and expansion coefficient of beads in water. Subsequently, anammox biomass entrapment by PVA-SA gel was introduced into continuous stirred tank reactor (CSTR). After 24 operation days, the nitrogen removal efficiency achieved 60%, while the nitrogen loading rate (NLR) was $0.14kgN/m^3/d$ and the experiment data indicated that PVA-SA gel bead crosslinked with sodium sulfate can be used to initiate anammox process. Furthermore, it is an alternative for culturing anammox in a long-term operation.