• Journal of Bio-Environment Control
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• v.7 no.1
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• pp.55-61
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• 1998

This experiment was conducted to evaluate the effects of sulfate ion concentration in nutrient solution on the growth and qualify of Mongolian wormwood (Artemisia mongolica var. tenuifolia). Sulfate ion concentration was treated 0, 0.5, 1, 2 and 3mM using the modified nutrient solution composition for herb plants developed by European Vegetable R & D Center in Belgium. The growth of Mongolian wormwood was good at 3mM treatment and dry weight was best at 3mM treatment, Chlorophyll content increased with sulfate ion concentration. Mineral content did not show any significant difference among treatments. But Ca content in tissue markedly decreased at 3mM treatment. Sulfate ion uptake increased in proportion to sulfate ion concentration in nutreint solution, the higher sulfate ion concentration, the more uptake of sulfate ion by plant. At 1mM sulfate ion treatment, essential oil content was best, but the higher sulfate ion concentration resulted in decrease of essential oil content.

• Asian-Australasian Journal of Animal Sciences
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• v.19 no.4
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• pp.601-604
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• 2006

The objective of this study was to investigate technical methods for extraction of mucopolysachharide-protein containing chondroitin sulfate from keel cartilage of chickens. The chemical composition of chicken keel cartilage was determined. For the preparation of mucopolysaccharide-protein from lyophilized chicken keel cartilage, hot water extraction and alcalase hydrolysis methods were examined. Results showed that the optimum condition of hot water extraction was incubation for 120 min with a yield of 40.09% and chondroitin sulfate content of 28.46%. For alcalase hydrolysis, the most effective condition was 2% alcalase in 10 volumes of distilled water for 120 min. The yield of hydrolysate was 75.87%, and chondroitin sulfate content was 26.61%. For further separation of chondroitin sulfate from the alcalase hydrolysate, which has a higher yield than that of hot water, 60% ethanol precipitation was performed. The yield of the ethanol precipitate was 21.41% and its chondroitin sulfate content was 46.31%. The hot water extract, alcalase hydrolysate and ethanol precipitate showed similar electrophoretic migration with standard chondroitin sulfate (chondroitin sulfate A), using cellulose acetate membrane electrophoresis. These results indicated that a significant amount of mucopolysaccharide-protein containing chondroitin sulfate could be acquired form chicken keel cartilage. Therefore, keel cartilage in chicken may provide an inexpensive source of chondroitin sulfate for commercial purposes.

• Journal of the Korean Ceramic Society
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• v.44 no.9
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• pp.465-470
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• 2007

This paper presents an experimental study of the sulfate resistance of mortars and pastes exposed to sodium sulfate solutions up to one year. In order to check deterioration modes due to sulfate attack, the sodium sulfate solution was varied at three concentration steps (3,380, 10,140 and 33,800 ppm of $SO_4^{2-}$ ions), and maintained at ambient temperature. The tests include a visual examination, expansion and compressive strength loss measurements as well as x-ray diffraction tests. The experimental data indicated that the use of cement with a low $C_3A$ content and low silicate ratio has a beneficial effect on the sulfate attack of mortars. In contrast, the mortars with a high $C_3A$ content and high silicate ratio became severely degraded due to the formation of ettringite, gypsum and/or thaumasite in the cement matrix.

• The Journal of Korean Academy of Prosthodontics
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• v.28 no.1
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• pp.137-163
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• 1990

The properties of a investment material can be described by the consistency at the slurry state, the setting time, the compressive strength and the thermal expansion during the casting. In this study the effect of the production parameters which are included the ratio of quartz and cristobalite, the content of binder, the water powder ratio and the content and concentration of additives on the Properties of the gypsum-bonded investments has been investigated with help of the consistency test, the vicat needle test, the compressive strength test, the thermal expansion test, x-ray diffraction and DTA thermal differential test. The experimental results showed that the constitution of a investment with W/P ratio of 0.34, 30% of gypsum, 0.8% aluminium sulfate, 2% magnesium sulfate, 0.6% sodium phosphate was adapted for the properties of the KDA Spec. No. 13 type I investment. The important experimental results are summarized as follows. 1. The consistency of the investment decreased with increasing amount of aluminium sulfate and decreasing amount of sodium phosphate. An addition of magnesium sulfate up to 2% an increase of the consistency was shown. But 3% magnesium sulfate in investment showed a decrease of the consistency. The consistency did not vary significantly with a variation of the content of gypsum and cristobalite and the W/P ratio. 2. Aluminium sulfate and the magnesium sulfate promoted the hardening and the aluminium phosphate delayed the hardening. The setting time increased with amount of gypsum. The effect of the matrix on the setting time was insignificant. With the W/P ratio of 0.34 the setting time was 14 min. 3. The compressive strength decreased with the amount of aluminium sulfate up to 0.25% and increased with the amount of aluminium sulfate greater than 3%. The compressive strength decreased as decreasing the amount of magnesium sulfate and gypsum and as increasing the W/P ratio. The effect of the refractory on the compressive strength was also not significant. With the W/P ratio of 0.34 the compressive strength was $34Kg/mm^2$. 4. The 1st thermal expansion was found at the temperature near and the steady state or the contraction stage was found at the temperature between $250^{\circ}C$ and $500^{\circ}C$. After this stage the 2nd thermal expansion took place at the temperature near $500^{\circ}C$. The amount of thermal expansion increased with decreasing the content of magnesium sulfate, aluminium sulfate and gypsum and the W/P ratio. And the amount of thermal expansion increased as the content of sodium phosphate and cristobalite. With the W/P ratio of 0.34 the amount of total expansion was 1.2%.

• The Journal of Korean Academy of Prosthodontics
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• v.29 no.1
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• pp.139-165
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• 1991

The properties of a investment material can be described by the consistency at the slurry state, the setting time, the compressive strength and the thermal expansion during the casting. In this study the effect of the production parameters which are included the ratio of quartz and cristobalite, the content of binder, the water powder ratio and the content and concentration of additives on the properties of the gypsum-bonded investments has been investigated with help of the consistency test, the vicat needle test, the compressive strength test, the thermal expansion test, x-ray diffraction and DTA thermal differential test. The experimental results showed that the constitution of a investment with W/P ratio of 0.34, 30% of gypsum, 0.8% aluminium sulfate, 2% magnesium sulfate, 0.6% sodium phosphate was adapted for the properties of the KDA Spec. No. 13 type I investment. The important experimental results are summarized as follows. 1. The consistency of the investment decreased with increasing amount of aluminium sulfate and decreasing amount of sodium phosphate. An addition of magnesium sulfate up to 2% an increase of the consistency was shown. But 3% magnesium sulfate in investment showed a decrease of consistency. The consistency did not vary significantly with a variation of the content of gypsum and cristobalite and the W/P ratio. 2. Aluminium sulfata and the magnesium sulfate promoted the hardening and the aluminium phoshpate delayed the hardening. The setting time increased with amount of gypsum. The effect of the matrix on the setting time was insignificant. With the W/P ratio of 0.34 the setting time was 14 min. 3. The compressive strength decreased with the amount of aluminium sulfate up to 0.25% and increased with the amount of aluminium sulfate greater than 3%. The compressive strength decreased as decreasing the amount of magnesium sulfate and gypsum and as increasing the W/P ratio. The effect fo the refractory on the compressive strength was also not significant. With the W/P ratio of 0.34 the compressive strength was $34Kg/mm^2$. 4. The 1st thermal expansion was found at the temperature near $250^{\circ}C$ and the steady state or the contraction stage was found at the temperature between $250^{\circ}C$ and $500^{\circ}C$. After this stage the 2nd thermal expansion took place at the temperature near $500^{\circ}C$. The amount of thermal expansion increased with decreasing the content of magnesium sulfate, aluminium sulfate and gypsum and the W/P ratio. And the amount of thermal expansion increased as the content of sodium phosphate ad cristobalite. With the W/P ratio of 0.34 the amount of total expansion was 1.2%.

• 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 Korean Society of Radiology
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• v.14 no.5
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• pp.627-634
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• 2020

Instead of lead, we intend to develop shielding materials for morphological implementation by mixing barium sulfate, an eco-friendly substance, and PLA filament, a 3D printer material. The environmental substance, barium sulfate powder and PLA filament, a 3D printer material, were used, and the shielding was made with a 3D printer after being fused into an extruder to mix the powder powder of barium sulfate with PLA. To check the mixing ratio of barium sulfate powder and PLA filament, the mixing input was analyzed, and the absorption dose by thickness according to barium sulfate content was obtained to check the shielding function of the mixed shielding. In the evaluation of the mixture of sulfate barium powder particles and PLA filaments, it was mixed in the most appropriate proportion when the content was 30% in the apparent and electron microscopic observation photographs. In the absorption dose results by thickness according to barium sulfate content, the difference between the content of 0% and the content of each % was greatest at 0.5 cm in thickness and the lowest dose value at 3 cm in thickness when the barium content was 30%. In addition, as the barium content began to increase at 30%, the absorbed dose value increased again. Instead of conventional lead, barium sulfate, an eco-friendly substance, could be mixed with PLA, a filament material, to create morphological shielding. Based on this study, it is expected that the mixing ratio of barium to the mixture is the most appropriate 30%, and will be used as the basis for the implementation of morphological shielding using 3D printers in the diagnosis and treatment section.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.4
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• pp.391-418
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• 1983

Urea and ammonium sulfate without and with sulfur group, respectively, were compared with respect to their nutritive effects on the rice plants, Suweon 264 and Jinheung, under the nursery trial on the protected upland and lowland seedbed, the pot trials with their various combination ratios and with added sodium sulfate to urea and the trials on the paddy fields which have undergone urea and ammonium sulfate application for many years. The rice seedlings fertilized with ammonium sulfate surpassed those with urea in growth performance and nutrients absorption of the rice seedlings at nursery period. Such stimulating effect of ammonium sulfate on the growth and nutrients uptake was more remarkable under the upland nursery than under the lowland one. The pot trial with the various combination ratios of urea and ammonium sulfate revealed that the chlorophyll content in leaf blade increased with the increment of sulfate ratio in the combination and the sole application of urea caused the chlorosis of leaf which was more conspicuous in Suweon 264 than in Jinheung. Fertilized with the same active ingradient amount of nitrogen, the rice plants supplied with ammonium sulfate surpassed those with urea in the chlorophyll content consistently under the nursery, the pot and the paddy field trials. The photosynthesis of flag leaf at heading stage increased with the combination rate of ammonium sulfate in the pot trial. The sulfur applicated as supplementary element of nitrogen in the nursery, the pot and the field trials were observed to be in positive relationship to the nitrogen and potassium content, but to be in negative correlation to the calcium content. The sulfur content in the rice plants was higher at early growth stage and decreased with the advance in growth stage. The nitrogen content also showed a similiar tendency to the sulfur content, and the N/S ratio was higher at early growth stage than at later one. The N/S ratio was negatively correlated with the chlorophyll content. In the field experiment, ammonium sulfate surpassed urea in the number of productive tiller, dry matter production and unhulled rice yields, but much stimulating effect of ammonium sulfate on the grain production was shown to be less effective than that on the straw production. The nitrogen and major nutrients content in the rice straw at harvest were higher in the paddy field with long-term ammonium sulfate application than in that with long-term urea application, suggesting that the former might have greater potentiality in nutrients supply than the latter.

• Journal of Environmental Science International
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• v.28 no.2
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• pp.287-290
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• 2019

This study investigates the changes in ammonia fluxes, pH and total nitrogen of liquid ferrous sulfate-treated litter over 5 weeks. A total of 200 broiler chicks (Arbor Acres, 1 d old) was separated into two treatment groups (0 g and 100 g liquid ferrous sulfate/kg litter) with four replications of 25 birds in each group. Liquid ferrous sulfate was sprayed on the litter by using a small sprayer. There was no difference (p>0.05) in the ammonia fluxes observed between the control and liquid ferrous sulfate treatment groups at 0, 1, and 5 weeks, except for 2, 3 and 4 weeks. At 5 weeks, the litter pH and total nitrogen content did not show any difference (p>0.05) between the control and liquid ferrous sulfate treatment groups. In conclusion, the use of liquid ferrous sulfate is not a suitable for use in poultry litter to reduce ammonia and pH or improve the total nitrogen content.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.6
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• pp.803-810
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• 2004

Water contents in fine particles at Seoul and Gosan are estimated by using a gas/particle equilibrium model, SCAPE (Simulating Composition of Atmospheric Particles at Equilibrium). Also, sensitivity of particulate inorganic ionic concentrations on the total ionic species is estimated. Water content at Gosan is more sensitive to ambient relative humidity (RH) than Seoul. At both sites water content is most sensitive to sulfate concentration among sulfate, nitrate, and ammonium. Solid salts levels and compositions are also studied.