• The Journal of the Korean dental association
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• v.12 no.12
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• pp.919-923
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• 1974

Serum calcium level was decreased by submaxillary gland removal in rate. To investigate the mechanisms involved in the above change, the authors examined the effects of thyroxine, vitamin D₂, and calcium gluconate, which influence the metabolisms of calcium and submaxillary gland, on the serum calcium level of the intact and submaxillary gland removal rats. The results were as follows: 1) Serum calcium level decreased by submaxillary gland removal. 2) Vitamin D₂, increased the serum calcium level significantly. 3) Thyroxine falied to recover the decreased serum calcium level induced by submaxillary gland removal to the control level. 4) In submaxillary gland removal rats, vitamin D₂ failed to increase the serum calcium level. 5) In thyroxine administered rats for 55 days, of which submaxillary glands were removed, vitamin D₂ failed to increase the serum calcium level. 6) The serum calcium level in intact rats was increased slightly, but increased significantly in submaxillary gland removal rats shortly after intravenous injection of calcium gluconate.

• Journal of the Korean Society of Clothing and Textiles
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• v.7 no.2
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• pp.19-25
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• 1983

The purpose of this study was to investigate the effects of laundry variables and additives on the removal of deposited calcium on the cotton fabric. Samples of calcium deposited fabric was made by treating fabric with $CaC1_2$ and $Na_2CO_3$ solution subsequently. The experimental variables were: 1) NaOH concentration ($0.0001\%$, $0.0005\%$, $0.001\%$, $0.005\%$, $0.01\%$) 2) Alkaline builders(sodium carbonate, sodium meta silicate) 3) Sequestering agents(STPP and EDTA concentration: $0.02\%$, $0.04\%$, $0.06\%$, $0.08\%$, $0.1\%$, $0.15\%$, $0.2\%$) 4) Temperatures($25\pm1^{\circ}C$, $40\pm1^{\circ}C$, $60\pm1^{\circ}C$) 5) Edge-abrasion to the removal of deposited calcium on the cotton fabric. The fabric was washed for 15 minutes in a washing machine(Model: Gold Star WP-3007) or Launder-0-meter(40$\~$45 r.p.m., Toyo Rika Instrument Inc.) and rinsed 3 times per every rinsing time. The amount of calcium deposits on the fabrics was determined by EDTA-back titration methods and edge-abrasion was evaluated by ASTM D 3886 method. The results of this study were as follows: 1) pH of surfactant solution(NaOH concentration) did not influence on the removal of deposited calcium on the cotton fabric. 2) Added alkaline builders did not influence on the removal of deposited calcium on the cotton fabric. 3) It was shown that STPP and EDTA were effective to remove deposited calcium. The removal of deposited calcium on the cotton fabric was proportionally increased with increasing concentration of STPP and EDTA. At high concentration, however, the rate was rather decreased with increasing concentration. 4) The temperature of washing solution did not influence on the removal of dedosited calcium on the cotton fabric. 5) As the removal of deposited calcium on the cotton fabric was increased, the rate of edge-abrasion of the fabric was gradually increased.

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.2
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• pp.153-159
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• 2004

This study was focused on evaluating physical properties and SO$_{x}$ removal capability of porous lime filters prepared by a foaming and a gelcasting method. Porosities of lime filters ranged from 55% to 85%, and their mean pore sizes were about 95 ${\mu}{\textrm}{m}$. It was observed that porous lime filters had the continuous pore structure that most pores were inter-connected by many windows. Before SO$_{x}$ removal reaction a surface of porous lime filters was made up of calcium oxide, but after reaction calcium sulfate became a main component. The SO$_{x}$ removal efficiency and the conversion ratio of calcium oxide to calcium sulfate increased according to reaction temperature and porosity. At 100$0^{\circ}C$, SO$_{x}$ removal efficiency of filters was always over 98% regardless of the porosity. In case of the filter with the porosity of 85%, the conversion ratios of calcium oxide increased according to the reaction temperature, and they were in the range 30% to 60%. to 60%.

• Food Science of Animal Resources
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• v.33 no.4
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• pp.515-521
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• 2013

In this study, we examined the effects of organic types of calcium derived from oyster shell (OS-Ca) and nano-calcium (Nano-Ca) on the bio-availability and physiological responses associated with bone health in ovariectomised rats. Increased body weight, which is one of the physiological effects of ovary removal, was significantly recovered by Nano-Ca treatment (p<0.05). The reduced calcium level in the liver in ovariectomised rat was increased significantly with OS-Ca and Nano-Ca treatment (p<0.05), suggesting improved calcium bio-availability. Alkaline phosphatase (ALP), osteocalcin, and deoxypyridinoline (DPD) were analysed as biochemical markers of bone metabolism and health in the presence or absence of OSCa and Nano-Ca. ALP, osteocalcin, and DPD levels increased following ovary removal and tended to decrease after treatment with Nano-Ca, indicating that Nano-Ca induces favourable bone metabolism. This result was reflected in the recovery of bone mineral density (BMD) and bone mineral content (BMC) of the femur after Nano-Ca treatment following ovary removal. Taken together, our data show that the tested calcium treatments, especially using Nano-Ca, enhanced the bioavailability or absorption of calcium and positively affected bone metabolism in ovariectomised rats.

• Journal of the Korean Society of Industry Convergence
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• v.16 no.2
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• pp.35-39
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• 2013

This paper synthesized the new copper removal agent(PW-2001) and investigated removal efficiency of copper, COD, calcium, SS and sludge amounts. Removal efficiency of copper were 96.1% and 99.1% with the lime and PW-2001, respectively while COD removals reached up to 38% and 69.6% with the use of lime and PW-2001. The concentrations of calcium and SS with PW-2001 were decreased 2.68 and 4.95 times lower than those with lime. Amount of sludge with PW-2001 was 60% smaller than lime. Quantity of PW-2001 needed for coagulation only reached 58.7, compared to lime standard quantity(100), and total cost of copper removal with PW-2001 was saved 25% more than lime.

• Proceedings of the Safety Management and Science Conference
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• 2013.11a
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• pp.547-560
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• 2013

In this study, the air pollutant removal such as sulfur oxides was studied. A combination of the plasma discharge in the reactor by the reaction surface discharge reactor Calcium hydroxides catalytic reactor and air pollutants, hazardous gas SOx, changes in gas concentration, change in frequency, the thickness of the electrode, kinds of electrodes and the addition of simulated composite catalyst composed of a variety of gases, including decomposition experiments were performed by varying the process parameters. The experimental results showed the removal efficiency of 98% in the decomposition of sulfur oxides removal experiment when Calcium hydroxides catalysts and the tungsten(W) electrodes were used. It was increased 3% more than if you do not have the catalytic. If added to methane gas was added the removal efficiency increased decomposition.

• Korean Chemical Engineering Research
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• v.59 no.2
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• pp.219-224
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• 2021

Ion flotation is an efficient method to remove metal ions from aqueous solution. In this work, ion flotation was applied to calcium removal from aqueous solution. The parameters used included sodium stearate (SS) and sodium dodecyl sulfate (SDS) as collectors, 1-butanol and 1-propanol as frothers, pH, and air-flow rate. An L16 orthogonal array was chosen according to the mentioned factors and levels, and experimental tests were conducted according to the Taguchi orthogonal array. The results showed that all of the factors except one had significant effect on the flotation performance. The percentage contribution of parameters showed that type of frother and type of collector made the greatest (43.14%) and the lowest (9.86%) contribution, respectively. In optimal conditions, the recovery of Ca (II) ion was 45.67%. Also, the results illustrated that the Taguchi method could predict calcium removal from aqueous solution by ion flotation with 2.63%. This study showed that the use of ion flotation was an effective method for Ca (II) ion removal from aqueous solution.

• Applied Chemistry for Engineering
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• v.30 no.6
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• pp.726-730
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• 2019

The removal of calcium ions using zeolite to solve problems of the CaCO₃ manufacturing process using cement kiln dust was investigated. To do so, a modified zeolite was employed and experiments were conducted to select the optimal zeolite type considered the binding cation and structure, evaluate the removal performance of calcium ions, the influence of the type and concentration of the modifying solution, and the removal selectivity when K coexists. Among five zeolites, 13X zeolite was found to have the best calcium ion removal performance, and it was confirmed that the removal performance was enhanced when KCl was used as a modifying solution instead of NaCl. This study is expected to be the basis for the solution of carbonation process and high concentration of KCl recovery technology.

• Environmental Engineering Research
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• v.10 no.5
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• pp.205-212
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• 2005

The study was conducted to investigate the removal of heavy metals by using Hydroxyapatite(HAp) made from waste oyster shells and wastewater with high concentration of phosphorus. The maximum calcium concentration for the production of HAp in this study was released up to 361 mg/L at pH of 3 by elution experiments. When the pH was at adjusted 6, the maximum calcium released concentration was 41 mg/L. During the elution experiment, most of the calcium was released within 60 minutes. This reaction occurred at both pH levels of 3 and 6. The result of the XRD analysis for the HAp product used in this study shows the main constituent was HAp, as well as OCP. The pH was 8.6. As the temperature increased, the main constituent did not vary, however its structure was crystallized. When the pH was maintained at 3, the removal efficiency decreased as the heavy metal concentration increased. The order of removal efficiency was as follows: $Fe^{2+}$(92%), $Pb^{2+}$(92%) > $Cu^{2+}$(20%) > $Cd^{2+}$(0%). Most of these products were dissolved and did not produce sludge in the course of heavy metals removal. As the heavy metal concentration increased at pH of 6, the removal efficiency increased. The removal efficiencies in all heavy metals were over 80%. From the analysis of the sludge after reaction with heavy metals, the HAp was detected and the OCP peak was not observed. Moreover, lead ion was observed at the peaks of lead-Apatite and lead oxidant. In the case of cadmium, copper and iron ions, hydroxide forms of each ion were also detected.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.09a
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• pp.219-222
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• 2004

Removal characteristics of Mn and Co was studied from the contaminated solutions via surface reaction with various calcium carbonate (calcite). Synthetic calcium carbonates which has different surface morphology as well as surface areas were prepared by a spontaneous precipitation method and used. Mn and Co removal behavior by the different solid surface demonstrate characteristic sorption behaviors depend on the type of calcite used, such as surface area or surface morphology. Calcium carbonate crystals (mostly calcite) which exhibit complicated surface morphology (c-type) shows strong sorption affinity for Mn and Co removal via sorption than on the a-type or b-type calcite crystals of less complicated surfaces. The applicability of two kinetic models, the pseudo-first-order kinetic equation and the Elovich kinetic model was examined on these sorption behavior. Elovich kinetic model was found more suitable to explain the very early stage adsorption kinetics, while the pseudo-first-order kinetic equation was successfully fitted for the adsorption kinetics after 50 hours.