• 한국자동차공학회논문집
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• 제23권2호
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• pp.199-207
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• 2015

Solid materials of ammonia sources with SCR have been considered for the application of lean NOx reduction in automobile industry, to overcome complex problems of liquid urea based SCR. These solid materials produce ammonia gas directly with proper heating and can be packaged by compact size, because of high volumetric ammonia density. Among ammonium salts and metal ammine chlorides, calcium ammine chloride was focused on this paper due to low decomposition temperature. In order to make calcium ammine chloride in lab-scale, simple reactor and glove box was designed and built with ammonium gas tank, regulator, and sensors. Basic test conditions of charging ammonia gas to anhydrous calcium chloride are chosen from equilibrium vapor pressure by Van't Hoff plot based on thermodynamic properties of materials. Synthetic method of calcium ammine chloride were studied for different durations, temperatures, and pressures with proper ammonia gas charged, as a respect of ammonia gas adsorption rate(%) from simple weight calculations which were confirmed by IC. Also, lab-made calcium ammine chloride were analyzed by TGA and DSC to clarify decomposition step in the equations of chemical reaction. To understand material characteristics for lab-made calcium ammine chloride, DA, XRD and FT-IR analysis were performed with published data of literature. From analytical results, water content in lab-made calcium ammine chloride can be discovered and new test procedures of water removal were proposed.

• 펄프종이기술
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• 제46권2호
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• pp.1-7
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• 2014

Causticizing calcium carbonate (CCC) is produced as a by-product in the causticization step of the kraft pulping process. It is often calcined in a rotary lime kiln after being dewatered and reused in the causticizing process. But for the China mill, the conventional recycled way is difficult because the CCC is mainly obtained from non-wood pulping materials, which higher silicon content led to serious silicon obstacle. So it is often discarded as solid waste or used in landfill after dewatering and secondary pollution is brought. In order to prevent its secondary pollution, recent years, the CCC is used as a filler in China papermaking industry. In mill trials, the CCC can be used to replace an amount of precipitated calcium carbonate (PCC). Unfortunately, the application scope and dosage of CCC have been limited due to its lower sizing efficiency than PCC. In this study, the reason for the lower sizing efficiency of alkyl ketene dimer (AKD) when CCC was used as a filler was investigated. The results showed that the materials in green liquid, such as insoluble matter in green liquid, silicon and metal ions, were a little influence on the sizing efficiency of AKD. The higher BET and BJH pore volume of the CCC were the main reason for lower sizing efficiency of AKD when it was used as filler.

• 대한화학회지
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• 제57권3호
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• pp.365-369
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• 2013

With the wide application of ASP (alkaline-surfactant-polymer) flooding, the scaling becomes more and more serious, which is harmful to the oilfield and environment. In order to investigate the effects of HPAM on calcium carbonate crystallization, the crystallization behaviors of $CaCO_3$ in HPAM (Hydrolyzed polyacrylamide) solutions were studied and the composition and morphology of $CaCO_3$ crystal were investigated in different concentrations of polyacrylamide solutions. The crystal forms and morphologies of $CaCO_3$ were characterized by Fourier transform infrared spectroscopy, X-ray diffraction and scanning electron microscopy. The results show that the crystallization of $CaCO_3$ is strongly influenced by the HPAM. The paper analyzed the internal cause, and the results show: The reasons leading to the change of morphology are carboxyl groups in polyacrylamide molecule and $Ca^{2+}$ in solution form chelates by coordination bond. And the chelates are adsorbed on the calcium hydroxide surfaces of solid-liquid interfaces so as to change the formation rate of calcium carbonate crystal nucleus. The research provides a reliable basis for the mechanism research of the scaling problem in the oil extraction process of ASP flooding and the adoption of scale inhibition and scale inhibitor.

• 치위생과학회지
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• 제17권4호
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• pp.352-357
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• 2017

액상소화제의 법랑질 부식능을 알아보기 위하여 마트에서 쉽게 구입할 수 있는 2종의 액상소화제와 약국에서 판매하는 1종의 액상소화제 그리고 대조군으로 생수를 선정하였다. 음료의 pH와 적정산도를 측정하고, 시편을 제작하여 음료에 1, 3, 5, 10, 15, 30분을 침지한 후 나타나는 양상을 표면 미세 경도계로 측정하여 다음과 같은 결론을 얻었다. 대조군인 생수를 제외한 모든 액상소화제의 pH가 4.0 이하로 나타났으며 위청수에서 $2.93{\pm}0.00$으로 가장 낮았다. pH 5.5로 변환하는 데 필요한 적정산도 또한 위청수에서 1.27 ml로 가장 높게 나타났다. 모든 액상소화제에서 침지시간이 증가함에 따라 표면경도가 감소하였으며 음료 30분 처리 후 표면 경도값은 위청수에서 $207.80{\pm}15.52$ VHN으로 가장 낮았고, 까스활명수 $216.86{\pm}4.01$, 생록천 $223.28{\pm}9.56$ 순이었다. 실험에 사용된 모든 액상소화제는 치아 법랑질에 부식을 유발하였으며, 음료처리 후에 pH가 가장 낮고 적정산도가 가장 높은 위청수에서 가장 낮은 표면 경도 값을 보여 실험에 사용된 액상소화제 중 가장 많은 법랑질 부식을 유발하였다. 따라서 액상소화제의 섭취는 법랑질표면경도를 감소시켜 치아 부식을 유발할 수 있으므로 이에 대한 대처방안이 마련되어야 할 것이다.

• Mass Spectrometry Letters
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• 제12권4호
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• pp.163-171
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• 2021

Emiliania huxleyi is a marine phytoplankton that plays a critical role in global carbon and sulfur cycling. The genome of E. huxleyi has been sequenced, and an in-depth proteomic profile of this organism has been reported. This study analyzed the phosphoproteome of E. huxleyi and identified its changes under calcium-limited conditions. A TiO₂ microcolumn was used for phosphopeptide enrichment, followed by liquid chromatography-tandem mass spectrometry analysis. Overall, we identified 7,010 phosphorylated sites on 3,355 phosphopeptides associated with 2,929 phosphoproteins in E. huxleyi. Quantitative analysis revealed changes in the phosphoproteome in E. huxleyi when ambient conditions changed to calcium-limited conditions, notably the phosphorylation of some transporters was altered. This study provides an overview of protein phosphorylation in E. huxleyi and paves the way for further investigations of its biological functions.

• 한국구조물진단유지관리공학회 논문집
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• 제9권4호
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• pp.261-269
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• 2005

본 연구의 목적은 칼슘 함량이 낮은 플라이 애쉬를 이용하여 포틀랜트시멘트를 대신할 수 있는 알칼리활성 플라이 애쉬-시멘트를 제조하는데 있다. 플라이 애쉬의 활성화는 다양한 수산화나트륨 농도와 온도 그리고 liquid/fly ash 혼합비율에서 수행하였다. 좀 더 높은 압축강도를 가진 경화체를 얻기 위하여 규산나트륨을 알칼리 용액에 첨가하였다. 강도발현의 관점에서 볼 때, liquid/fly ash의 혼합비율과 활성화제 농도 그리고 온도는 항상 중요한 인자로 작용하였다. $NaOH(210g)+Na_2SiO_3{\cdot}9H_2O(30g)+H_2O=1L$로 구성된 알칼리 활성용액은 $50^{\circ}C$에서 칼슘 함량이 낮은 플라이 애쉬의 알칼리활성 효과를 가장 높게 나타냈다. 알칼리활성화된 플라이 애쉬는 주로 quartz와 mullite 그리고 무정형의 aluminosilicate로 구성되었음을 SEM과 XRD 분석결과에서 보여주었다.

• 동아시아식생활학회지
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• 제14권3호
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• pp.233-242
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• 2004

The purpose of this study was to investigated the possibility of Meles meles as an edible functional resource. To assess the effects of Meles meles fermented liquid(ML) with medicinal plants in postmenopausal women, the menopause symptoms, hematological and serum chemical variables and bone health indices were examined. Twenty five postmenopausal women participated in the study. As a result, in postmenopausal women, ML supplements were effective in reducing the incidence of menopause symptoms, such as insomnia(44.0%), sensitivity(40.0%), headache(34.0%), hot flush and decreased vaginal lubrication(20.0%) after 12 weeks. Also serum estradiol and calcitonin and calcium levels were 23.27 pg/mL, 14.88 pg/mL and 8.86 mg/dL before the ML intake. Levels were significantly increased of estradiol and calcitonin and calcium after ML intake during 12 weeks to 30.36 pg/mL, 21.61 pg/mL and 10.01 mg/dL. Osteocalcin and bone alkaline phosphatase activity were 14.36 ng/mL, 21.55 U/L before the ML intake, but according to ML intake, the levels were significantly decreased. In conclusion, ML play benefical roles in the prevention of bone loss and menopause symptoms. Howere current data are not sufficient to determine the effective doses for benefical effect as well as harmful effect and support dietary recommendation level for ML. Therefore, our results should be viewed with caution. But Meles meles fermented liquid with medicinal plants can be used as possible food resources and functional food materials, more studies are needed to identify the proper mechanism of ML.

• 한국세라믹학회지
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• 제11권1호
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• pp.29-35
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• 1974

Effect of calcium sulfate and barium sulfate on the formation of portland cement clinker was studied by means of chemical analysis. DTA and X-ray diffraction analysis. In the presence of liquid phase, effect of the additives on the formation of tricalcium silicate was examined according to the reaction, 2CaO.$SiO_3$＋CaO$\longrightarrow$3CaO.$SiO_3$, which is the principal reaction in portland cement clinkerization, and optimum conditions in firing clinker concerning amount of additive, firing time and temperature were determined, and its kinetics was referred to. The experimental results are summerized as follow: (1) Appropriate burning temperature range of cement clinker is more limited as the content of calcium sulfate in clinker is increased. Amount of calcium sulfate, firing time and temperature in proper condition of clinkerization is related to each others. Being added suitable quantity of calcium sulfate, firing temperature of clinker can be lowered about $100^{\circ}C$. (2) When 3-5 mole% of calcium sulfate is added, firing time of 15-30 minutes at about $1380^{\circ}C$ is reasonable, and if the content is over7 mole %, firing for 1 hr. or more at $1350^{\circ}C$ is anticipated to be optimum condition. (3) In the reaction of tricalcium silicate formation, the role of barium sulfate as a mineralizer is similar to that of calcium sulfate, but the optimum firing temperature of cement clinker containing barium sulfate tends to be 20-$30^{\circ}C$ higher than that of clinker containing calcium sulfate. (4) When barium sulfate is used as mineralizer, 2-3 mole % of it to tricalcium silicate is recommended and if it is added more than this amount, free CaO is increased rapidly in clinker and alite formation is inhibited.

• 한국토양비료학회지
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• 제46권6호
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• pp.530-535
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• 2013

This study was carried out to investigate the effect of slurry composting and biofiltration (SCB) liquid manure application on shoot growth, fruit qualities and soil chemical properties in peach orchard. SCB liquid manure was fertigated ten times from April to October in SCB plot, whereas chemical fertilizer was treated two times as basal and additional fertilizers in control plot. The shoot growth, leaf nitrogen and potassium content, soil exchangeable K, fruit weight and yield were higher in SCB plot than in control. Soluble solid content and acidity, soil organic matter, soil available phosphate and soil exchangeable Mg showed no significant difference between treatments, and the leaf calcium and magnesium content were lower in SCB plot than in control. In conclusion, fertigating SCB liquid manure in peach orchard has positive effects on fruit weight and yield, and it is suggested that periodical soil testing is needed because of the possibility of K accumulation in SCB liquid manure treated soil when the orchard is fertigated based on the soil nitrogen content.

• 한국응용과학기술학회지
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• 제30권4호
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• pp.770-778
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• 2013

In this study, a liquid carbonation method was applied for producing precipitate calcium carbonate by liquid-liquid reaction. We recycled the recycling water of ready-mixed concrete, one of construction waste for use source of carbonate ion. A supernatant separated from the recycling water of ready-mixed concrete, as a result of ICP analysis of a cation, $Ca^{2+}$ was contained up to 1100 ppm. We used MEA as a $CO_2$ absorbent for the liquid carbonation. A precipitate $CaCO_3$ was produced at more than MEA 20 wt%. The precipitate $CaCO_3$ as a final product was separated and dried. The result of XRD was confirmed the generation of $CaCO_3$ to calcite structure.