• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.432-436
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• 2001

In this study, calcium sulfate(gypsum) powder was obtained using waste sulfuric acid and stainless refinery sludge by- produced from chemical reagent and the iron industry, by the neutralization of waste sulfuric acid. As variables for the experiment the mole ratio of the H$_2$SO$_4$ : Ca(OH)$_2$, the pH, the reaction temperature and time, the amount of catalyst were used. The crystal shape and microstructure of obtained powder were observed by XRD and SEM, and the thermal property was investigated by DTA. As the NaCl is added 0~20wt% as a catalyst to the H$_2$SO$_4$ : Ca(OH)$_2$, system it can be found that the crystal shape goes through the processes as follows : gypsum dihydratlongrightarrowgypsum hemihydrate＋gypsum dihydratelongrightarrowgypsum hemihydrate. And gypsum hemihydrate is $\beta$-type as the result of DTA. As waste sulfuric acid and stainless refinery sludge were used, the pH of reacted solution (which was 0.8) was rapidly raised up to 8~9 by the addition of stainless sludge and gypsum dihydrate was produced as a by-product. Therefore, it was found that stainless refinery sludge is sufficiently applicable for the neutralization of waste sulfuric acid.

• 한국농촌생활과학회지
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• 제3권
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• pp.27-35
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• 1992

• 한국조리학회지
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• 제13권4호
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• pp.119-127
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• 2007

Pine mushroom is excellent for its unique smell, nutrients and functional factors. The quality characteristics of Demi-glace sauce made from pine mushrooms that have not been used despite their value as good ingredients and mushrooms that have been added to various kinds of sauce were examined by differing pine mushroom and mushroom powder in stock. The more pine mushroom and mushroom powder was added, the content of minerals increased; however, the content of moisture decreased. Overall, viscosity was increased. The content of each mineral varied in proportion to pine mushroom and mushroom powder contents level. Sensory evaluation of pine mushroom added to demi-glace sauce showed difference in sweetness, savory taste overall. 0.2% addition of sweetness, 0.3% addition of savory taste, 0.2% and 0.3% addition of overall acceptability appeared as the best estimation. Specially, 0.2% addition was the highest in salty taste and color. As the two mushroom powder contents was increased, tastes of demi-glace sauce were not increased; rather, the appropriate amount of addition existed.

• 한국세라믹학회지
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• 제53권1호
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• pp.7-12
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• 2016

In this paper, we have developed a simple, new and economical carbonation method to synthesize a pure form of aragonite needles using dolomite raw materials. The obtained aragonite Precipitated Calcium Carbonate (PCC) was characterized by XRD and SEM, for the measurement of morphology, particle size, and aspect ratio (ratio of length to diameter of the particles). The synthesis of aragonite PCC involves two steps. At first, after calcinated dolomite fine powder was dissolved in water for hydration, the hydrated solution was mixed with aqueous solution of magnesium chloride at $80^{\circ}C$, and then $CO_2$ was bubbled into the suspension for 3 h to produce aragonite PCC. Finally, aragonite type precipitated calcium carbonate can be synthesized from natural dolomite via a simple carbonation process, yielding product with average particle size of $30-40{\mu}m$.

• 한국세라믹학회지
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• 제53권2호
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• pp.222-226
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• 2016

The synthesis of pure calcium carbonate nanocrystals was achieved using a simultaneous injection method to produce nano particles of uniform size. These were characterized using scanning electron microscopy and powder X-ray diffraction. The nano particles were needle-shaped aragonite polymorphs, approximately 100-200 nm in length. The aragonite polymorph of calcium carbonate was prepared using aqueous solutions of $CaCl_2$ and $Na_2CO_3$, which were injected simultaneously into double distilled water at $50^{\circ}C$ and then allowed to react for 1.5 h. The resulting whisker-type nano aragonite with high aspect ratio (30) is biocompatible and potentially suitable for applications in light weight plastics, as well as in the medical, pharmaceutical, cosmetic and paint industries.

• 자원리싸이클링
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• 제25권5호
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• pp.75-83
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• 2016

탄소환원질화법을 이용하여 질화알루미늄(Aluminum Nitride: AlN)을 제조하는 연구를 배치당 0.7 ~ 1.5 kg 규모로 규모 확대하여 수행하였다. 고품위 알루미나 분말과 탄소(carbon black)를 배합하여 흑연 도가니에 장입하고, 노내 진공도 $2.0{\times}10^{-1}Torr$에서 온도($1,550{\sim}1,750^{\circ}C$), 시간(0.5 ~ 4 hr), $N_2$유량($10{\sim}40{\ell}/min$)을 변화시키면서 AlN을 합성하였다. 실험결과 합성온도 $1,700{\sim}1,750^{\circ}C$, 합성시간 3시간, 질소유량 $40{\ell}/min$가 적정 조건이었다. 또한, 합성한 AlN에 잔존하는 탄소를 제거하기 위하여 관상로에서 온도 $650-750^{\circ}C$, 1 - 2시간 범위에서 탈탄을 시킨 결과, 알루미나와 탄소 몰배합비 1 : 3.2 로 합성한 시료를 대기 분위기에서 탈탄온도 $750^{\circ}C$, 관상로의 회전속도 1.5 rpm에서 2시간 탈탄하는 것이 적정조건이었다. 시험 제조한 AlN의 성분 분석 결과 C 함량 835 ppm, O 함량 0.77%으로서 순도 99% 이상의 고품위 제품을 제조할 수 있었다.

• 한국식품영양학회지
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• 제21권1호
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• pp.71-78
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• 2008

This study examined the effects of mulberry-leaf powder Tofu(MPT) on the anthropometric measurements, bone mineral density(BMD), biochemical markers of bone turnover, serum lipid levels of and macrominerals status in 30 female university students living in Choongnam with low dietary Ca intake was low(mean daily $intake=524.66{\pm}21.47$ mg/day). The subjects received the MPT supplemented(100 g/day) for 4 weeks. The nutrient content per 100 g MPT was 84.10 kcal(energy), 8.98 g(protein), 0.53 mg(fiber), 211.33 mg(Ca) and 1.59 g(fat). Anthropometric measurements, 24-hour dietary recall, carpus BMD using DEXA, select BMD biomarckers(serum alkaline phophatase activity, osteocalcin, urinary deoxypyridinoline), serum protein levels, albumin, and glucose levels, lipid profiles(cholesterol, triglyceride, HDL-cholesterol, LDL-cholesterol) and serum macrominerals(Ca, Ca/P ratio, Mg) were analyzed before and after MPT supplementation. Following MPT supplementation, there was no significant differences in anthropometric measurements, nutrient intakes, carpus BMD, serum alkaline phosphatase activity, osteocalcin, and urinary deoxypyridinoline, serum levels of protein, albumin, and glucose or lipid profiles with AI, HTR, LHR and CRF. However, there were significant increases in dietary calcium as well as decreases in serum triglycerides with MPT supplementation. Although further research is needed, these results that regular intake MPT could prevent bone and cardiovascular diseases.

• 동아시아식생활학회지
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• 제17권1호
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• pp.1-10
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• 2007

The effects of mulberry-leaf powder Tofu(MPT) on anthropometric measurements, including bone mineral density(BMD) in the right carpus, biochemical bone turnover markers, serum levels of lipids and macrominerals, were investigated in 30 smoking male adults who lived in Choongnam were given MPT(100 g/day) for 4 weeks. The average ages, number of smoked cigarettes and packyear were 22.38 years, 15.12/day and 3.54 years, respectively. The nutrient contents per 100 g MPT were 86.10 kcal energy, 8.98 g protein, 0.53 mg fiber, 211.33 mg Ca and 1.59 g fat. Anthropometric measurements, including dietary intake using the 24-hours recall method, carpal BMD using DEXA, serum levels of protein, albumin and glucose, lipid profiles (cholesterol, triglyceride, HDL-cholesterol, LDL-cholesterol) with Al(atherosclerosis index), HTR, CRF, LHBt, some biomarkers of BMD(serum alkaline phosphatase activity, osteocalcin, urinary DPD), and serum macrominerals(Ca, Ca/P ratio, Mg) and Pb were analyzed before and after consumption of MPT. After MPT consumption, dietary intakes of plant protein, total Ca and plant Ca increased significantly, but there were no significant differences in anthropometric measurements, BMD with bone metabolism markers, serum levels of protein, albumin or glucose, lipid profiles with AI, HTR, LHR and CRF.

• 한국지하수토양환경학회지:지하수토양환경
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• 제27권1호
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• pp.39-49
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• 2022

Bottom ash generated from thermal power plants is mainly disposed in landfills, from which metals may be leached by infiltrating water. To evaluate the effect of metals in leachate on soil and groundwater, we characterized bottom ash generated from burning cokes, bituminous coal, the mixture of bituminous coal and wood pellets, and charcoal powder. The bottom ash of charcoal powder had a relatively large particle size, and its wood texture was well-preserved from SEM observation. The bottom ash of charcoal powder and wood pellets had relatively high K concentration from total element analysis. The eluates of the bottom ash samples had appreciable concentrations of Ca, Al, Fe, SO₄, and NO₃, but they were not a significant throughout the batch test. Therefore, it is considered that there is low possibility of soil and groundwater contamination due to leaching of metal ions and anions from these bottom ash in landfills. To estimate the trend of various trace elements, long-term monitoring and additional analysis need to be performed while considering the site conditions, because they readily adsorb on soil and aquifer substances.

• Restorative Dentistry and Endodontics
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• 제45권4호
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• pp.50.1-50.11
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• 2020

Objectives: In this study, we investigated the potential of amoxicillin-loaded polymeric microspheres to be delivered to tooth root infection sites via a bioactive reparative cement. Materials and Methods: Amoxicillin-loaded microspheres were synthesized by a spray-dray method and incorporated at 2.5% and 5% into a mineral trioxide aggregate cement clinically used to induce a mineralized barrier at the root tip of young permanent teeth with incomplete root development and necrotic pulp. The formulations were modified in liquid:powder ratios and in composition by the microspheres. The optimized formulations were evaluated in vitro for physical and mechanical eligibility. The morphology of microspheres was observed under scanning electron microscopy. Results: The optimized cement formulation containing microspheres at 5% exhibited a delayed-release response and maintained its fundamental functional properties. When mixed with amoxicillin-loaded microspheres, the setting times of both test materials significantly increased. The diametral tensile strength of cement containing microspheres at 5% was similar to control. However, phytic acid had no effect on this outcome (p > 0.05). When mixed with modified liquid:powder ratio, the setting time was significantly longer than that original liquid:powder ratio (p < 0.05). Conclusions: Lack of optimal concentrations of antibiotics at anatomical sites of the dental tissues is a hallmark of recurrent endodontic infections. Therefore, targeting the controlled release of broad-spectrum antibiotics may improve the therapeutic outcomes of current treatments. Overall, these results indicate that the carry of amoxicillin by microspheres could provide an alternative strategy for the local delivery of antibiotics for the management of tooth infections.