• 제목/요약/키워드: Calcium Nitrate

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Low-Z Electron Probe X-ray Microanalysis 분석법을 이용한 해안인근 지역의 대기입자 분석 (Characterization of Individual Atmospheric Particles, Collected in Susan, Korea, Using Low-Z Electron Probe X-ray Microanalysis)

  • 김혜경;노철언
    • 한국대기환경학회지
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    • 제19권5호
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    • pp.503-513
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    • 2003
  • A single particle analytical technique, called low-Z electron probe X-ray microanalysis (low-Z EPMA) was applied to characterize atmospheric particles collected in Busan, Korea, over a daytime period in Dec. 2001. The ability to quantitatively analyze the low-Z elements, such as C, N, and 0, in microscopic volume enables the low-Z EPMA to specify the chemical composition of individual atmospheric particle. Various types of atmospheric particles such as organics, carbon-rich, aluminosilicates, silicon oxide, calcium carbonate, iron oxide, sodium chloride, sodium nitrate, ammonium sulfate, and titanium oxide were identified. In the sample collected in Busan, sodium nitrate particles produced as a result of the reaction between sea salt and nitrogen oxides in the atmosphere were most abundantly encountered both in the coarse and fine fractions. On the contrary, original sea salt particles were rarely observed. The fact that most of the carbonaceous particles were distributed in the fine fraction implies that their origin is anthropogenic.

펄프 섬유의 세포벽 미세공극 충전 (Cell Wall Micropore Loading of Pulp Fibers)

  • 이종만;조병묵
    • Journal of the Korean Wood Science and Technology
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    • 제20권4호
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    • pp.57-64
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    • 1992
  • The unique cell wall micropores of pulp fiber can be utilized as loading site in variety of important practical application which could be the basis of new papermaking technologies. One of these includes the manufature of paper containing higher levels of in situ filler precipitated. Hardwood pulp fiber were first impregnated with the solution of sodium carbonate($Na_2CO_3$). The micropores in cell wall of pulp fibers were filled with the liquid salt solution. The second calcium nitrate($Ca(NO_3)_2$) solution formed an insoluble calcium carbonate($CaCO_3$) precipitate within the cell wall micropores by interacting with the first sodium carbonate solution. The effects of chemical concentration and dryness of pulp fibers on the retention of cell wall micropore loaded filler were investigated. The paper properties of cell wall micropore loaded pulp fibers were compared with those of conventionally loaded and lumen loaded pulp fibers. Also the presense of the fillers within the cell wall micropore was observed by SEM. Increasing the chemical concentration to generate the calcium carbonate increased the retention of filler in cell wall micropore loaded pulp fibers. The particle size distribution of precipitated calcium carbonate ranged from $0.1{\mu}m$ to $80{\mu}m$. But, the average particle size of cell wall micropore loaded calcium carbonate was $4{\mu}m$. The paper made from never dried pulp fibers, the cell wall micropores which were filled with calcium carbonate, had better mechanical and optical properties than those of conventionally loaded or lumen loaded pulp fibers.

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Low-Z Particle Electron Probe X-ray Microanalysis를 이용한 2001년 서울시 대기 중 입자상 물질 분석 (Single Particle Analysis of Atmospheric Aerosol Particles Collected in Seoul, 2001, Using Low-Z Particle Electron Probe X-ray Microanalysis)

  • 구희준;김혜경;노철언
    • 한국대기환경학회지
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    • 제20권6호
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    • pp.823-832
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    • 2004
  • Atmospheric aerosol particles collected in Seoul on four single days, each in every seasons of 2001, were characterized and classified on the basis of their chemical species using low-Z particle electron probe X-ray microanalysis (low-Z particle EPMA). Low-Z particle EPMA technique can analyze both the size and the chemical species of individual aerosol particles of micrometer size and provide detailed information on the size distribution of each chemical species. The major chemical species observed in Seoul aerosol were aluminosilicate, silicon dioxide, calcium carbonate, organic, carbon-rich, marine originated, and ammonium sulfate particles, etc. The soil originated species, such as aluminosilicate, silicon dioxide, and calcium carbonate were the most popular in the coarse fraction, meanwhile, carbonaceous and ammonium sulfate were the dominant species found in the fine fraction. Marine originated species such as sodium nitrate was frequently encountered, up to 30% of the analyzed aerosol particles.

고산에서의 1994년 3월 - 4월 측정연구: (I) 입자상 오염물질의 이동 (Measurement Study at Kosan, Cheju Island during March-April, 1994: (I) Transport of Ambient Aerosol)

  • 김용표;박세옥;김진영;심상규;문길주;이호근;장광미;박경윤;강창희
    • 한국대기환경학회지
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    • 제12권1호
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    • pp.79-90
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    • 1996
  • Total suspended particles were measured at Kosan, Cheju Island, Korea during the period of March 11 .sim. April 19, 1994. Concentrations of non-sea salt(nss) ions were higher than those measured at clean marine areas in Japan and other background marine areas in the world. Especially, nss sulfate concentration is compatable to thoes measured at Seoul. It is suggested that most nss sulfate concentration is originated from anthropogenic sources. Nss sulfate concentration shows strong correlation with ammonium and nss potassium concentrations while shows no a pparent correlation with nitrate and nss calcium concentrations. Nss calcium concentrations shows strong correlation with nss potassium and mss magnesium concentrations. It is deduced that nss potassium has two origins, one anthropogenic, the other crustal. Backward trajectory analysis results show the trajectories of air parcel during the measurement period were mostly originated from China. It is shown that cases of high nss sulfate with high nss calcium can occur when an air parcel originated from arid and semi-arid regions of morthwestern China or Mongolia passes through northeastern China.

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Electrochemical behavior of Calcium Titanate Coated Ti-6Al-4V Substrate in Artificial Saliva

  • Lee, Byoung-Cheon;Balakrishnan, A.;Ko, Myung-Won;Choi, Je-Woo;Park, Joong-Keun;Kim, Taik-Nam
    • 한국재료학회지
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    • 제18권1호
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    • pp.22-25
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    • 2008
  • In this study, calcium titanate $(CaTiO_3)$ gel was prepared by mixing calcium nitrate and titanium isopropoxide in 2-methoxy-ethanol. $CaTiO_3$ gel was single-layer coated on Ti-6Al-4V using a sol-gel dip-coating technique. The coating was calcined at $750^{\circ}C$ in air by utilizing a very slow heating rate of $2^{\circ}C/min$. The crystalline phases of the coating were characterized by x-ray diffraction using a slow scan rate of $1^{\circ}/min$. The morphology of the coating was analyzed by scanning electron microscopy. The corrosion behavior of Ti-6Al-4V samples coated with $CaTiO_3$ films were tested in an artificial saliva solution by potentiodynamic polarization and were quantified by the Tafel extrapolation method. The electrochemical parameters showed a considerable increase in the corrosion resistance for the $CaTiO_3$-coated Ti-6Al-4V samples compared to bare substrates.

Effect of calcium hydroxide on inflammatory root resorption and ankylosis in replanted teeth compared with other intracanal materials: a review

  • Jahromi, Maryam Zare;Kalantar Motamedi, Mahmood Reza
    • Restorative Dentistry and Endodontics
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    • 제44권3호
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    • pp.32.1-32.13
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    • 2019
  • Calcium hydroxide (CH) is the gold-standard intracanal dressing for teeth subjected to traumatic avulsion. A common complication after the replantation of avulsed teeth is root resorption (RR). The current review was conducted to compare the effect of CH with that of other intracanal medications and filling materials on inflammatory RR and replacement RR (ankylosis) in replanted teeth. The PubMed and Scopus databases were searched through June 2018 using specific keywords related to the title of the present article. The materials that were compared to CH were in 2 categories: 1) mineral trioxide aggregate (MTA) and endodontic sealers as permanent filling materials for single-visit treatment, and 2) Ledermix, bisphosphonates, acetazolamide, indomethacin, gallium nitrate, and enamel matrix-derived protein (Emdogain) as intracanal medicaments for multiple-visit management of avulsed teeth prior to the final obturation. MTA can be used as a single-visit root filling material; however, there are limited data on its efficacy due to a lack of clinical trials. Ledermix and acetazolamide were comparable to CH in reducing RR. Emdogain seems to be an interesting material, but the data supporting its use as an intracanal medication remain very limited. The conclusions drawn in this study were limited by the insufficiency of clinical trials.

제주도 지하수의 증분변화에 대한 고제 (A survey on the fluctuation of dissolved solids into the groundwater in Chejudo)

  • 금성홍;신승종;오상실;송가기;오순미
    • 환경위생공학
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    • 제8권1호
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    • pp.67-80
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    • 1993
  • This survey was carried out to take the status of seawater intrusion into groundwater wells located in the eastern area of Chejudo, to get the elementary data which may evaluate the level of would-be groundwater contamination, and to perform effective the effort that will supply the clear water for the residents. The sampling sites were northeastern districts of Haengwon, Handong, and Sangdo, southeastern districts of Susan, Nansan, and Samdal, and northwestern districts, as reference, of Aewol, Keumnung, Panpo, Kosan, Shindo, and Bosung. We collected the samples from the public tap water by month, and analysed electrical conductivity, sodium(Na), potassium(K), magnesium(Mg), calcium(Ca), bicarbonate($HC0_{3^-}$), and items of the criteria as drinking water. In the northeastern districts we also added the sampling sites to survey the fluctuations of dissolved solids according to distance from seashore, including two private boreholes and one public tap water of Dukchun. The result is as follows 1) In the northeastern district, the concentration of chloride ion showed large fluctations from 40mg/l to 100mg/l, but suitable for the criteria of drinking water. It was thought that the drought influenced. 2) In the Sangdo of the northeastern districts, similar tendancy to Hangwon and Handong was showed only in the concentration of chloride ion, but different tendancy was showed in chloride-bicarbonate ratio, calcium-magnesium ratio, and sodium adsorption ratio(SAR). Considering these facts, it was not thought that seawater intruded. 3) The components of Na and Cl showed rapid slope in the northeastern districts above 3km from seashore. 4) In the northwestern districts as reference, the concentration of chloride ion fluctuated slightly according to the sampling sites and dates, and the concentration of nitrate-nitrogen in some sites exceeded the criteria of drinking water. These were thought that the surface contaminants rather than the intrusion of seawater influenced mainly the groundwater, considering the correlation(r=0.732) of chloride ion and nitrate-nitrogen. 5) Then we must consider the regional characteristies of soil profile in order to prevent the contamination of groundwater, and moniter also the movement of main components within the sol1 profile, not only the research of the intrusion of seawater.

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도라지 유묘기 액비처리가 질소와 인산의 식물체 흡수 및 생육에 미치는 영향 (Influence on Platycodon grandiflorum Absorption of Nitrogen and Phosphorous Acid and Growth during Seedling Stage by Liquid Fertilizers Treatment)

  • 이철호;이신우;안미정;조광복;이협
    • 한국약용작물학회지
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    • 제19권4호
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    • pp.227-232
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    • 2011
  • The roots of Platycodon grandiflorum has been widely used as a crude drug or a food stuff. Unfortunately, the output and the quality is not regular and highly dependent on the cultivation area and cultivation method. Therefore, seedling cultivation study of this plant under structure with various fertilizer supply was performed. As a result, significant big difference between ammonia nitrogen and nitrate nitrogen content was shown in the root at seedling stage while the difference was not significant in the aerial parts. Fresh weight of the root (7.73 g plant$^{-1}$) was higher in the group treated with three major nutrients (N, P and K) than in those treated with three major nutrients and calcium or magnesium or both calcium and magnesium, and non-treated group (2.69 g plant$^{-1}$). Total nitrogen content was recognized to be significantly correlated with root weight, plant height, number of leaves and weight of aerial parts. Ammonium nitrogen content was more correlated the growth of P. grandiflorum than nitrate nitrogen. For phosphoric acid, significant correlation was also shown with the four growth factors.

좀나무싸리버섯(Clavicorona pyxidata)의 균사체 최적 배양조건 및 세포효소활성 특성 (Optimized Culture Condition and Enzyme Activity of the Mycelia of Clavicorona pyxidata)

  • 이태희;김진만;한영환
    • 미생물학회지
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    • 제42권2호
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    • pp.131-134
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    • 2006
  • Clavicorona pyxidata DGUM 29005의 균사 생육을 위한 최적 배양조건 및 효소 활성을 조사하였다. 균사 생육을 위한 최적 온도 및 pH는 각각 $24^{\circ}C$ 및 5.0이었다. 사용된 복합배지 중 malt extract medium (MEM)에서 가장 좋은 균사 생육을 나타내었다. 최소배지로 Czapek-Dox 한천배지를 사용하고 탄소원으로 trehalose, mannitol, sucrose 및 maltose 첨가시 균사생육이 우수하였다. 전반적으로 무기질소원이 유기질소원 보다 균사 생육을 더 촉진하였으며, 무기질소원으로 calcium nitrate를 사용하였을 때 균사 생육이 가장 우수하였다. 인산원으로 $Na_2HPO_4$를 사용했을 때 균사생육이 촉진되었으며, 가장 우수한 비타민원은 p-aminobenzoic acid이었다. MEM 액체배지를 사용하여 $24^{\circ}C$에서 20일간 C. pyxidata DGUM 29005를 배양하여 균사외 분비효소 및 균사내 효소의 활성도를 측정한 결과, 균사외 분비 효소 중 laccase의 활성도가 다른 효소에 비해 높았으며, ${\alpha}$-amylase, chitinase, lipase 및 pretense의 활성도는 낮거나 없었다.

KOH/KL제올라이트 및 Ca/미역촤를 이용한 대두유의 전이에스테르화 반응 (Transesterification of Soybean Oil Using KOH/KL Zeolite and Ca/Undaria pinnatifida Char)

  • 조용범;박성훈;전종기;박영권
    • 공업화학
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    • 제23권6호
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    • pp.604-607
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    • 2012
  • 본 연구에서는 표면적이 높은 제올라이트나 촤를 지지체로 이용해 알칼리금속을 담지시킴으로써 염기 세기를 증가시켜 전이에스테르화 반응에 있어 보다 좋은 활성을 가지는 고체촉매를 만들고자 하였다. 제올라이트는 KOH 수용액으로 담지하였고, 미역촤는 calcium nitrate를 담지하여 염기의 세기를 증가시켰다. Hammett 지시약과 $CO_2$-TPD를 통하여 촉매의 특성을 분석하였다. 대두유과 메탄올을 사용하여 바이오디젤을 합성한 후 지방산 메틸에스테르 함유량을 측정함으로서 촉매의 활성을 알아보았다. 일정량까지는 담지량과 활성이 비례하였으나, 과량 담지 시 오히려 활성이 감소하는 결과를 보였다.