• The Korean Journal of Physiology
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• 제16권1호
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• pp.1-11
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• 1982

Force development of smooth muscle cells is directly regulated by the concentration of free calcium ions in the sarcoplasm, and the sarcoplasmic concentration of calcium ion can be modulated by electrogenic Na-K pump. The role of Na-K pump on vascular tone was studied in isolated rabbit renal artery. Helical strips of arterial muscle were prepared from left renal arteries. All experiments were performed in $HCO_3^--buffered$ Tyrode solution which was aerated with $3%CO_2-97%\;O_2$ mixed gas and kept at $35^{\circ}C$. In some experiments, rabbit was injected intraperitoneally $18{\sim}24$ hours prior to the experiments, with a large dose(5 mg/kg body wt) of reserpine, in order to eliminate the catecholamines present in intrinsic adrenergic nerve terminate. Treatment used in this experiment that inhibits Na-K pump was the exposure of strips to K-free Tyrode solution. Contractile response to K free Tyrode solution developed slowly and the time required for maximum contracture was $20{\sim}30$ minutes. This K-free contracture was rapidly relaxed by the addition of potassium to the bathing solution. No K-free contracture occurred in a Ca-free Tyrode solution. But contraction developed rapidly when calcium ion was added to the bathing solution after 30 minute exposure of the strip to Ca-free Tyrode solution. This contracture was completely inhibited by Ca-antagonist, verapamil. The K-free contracture was abolished by ${\alpha}-adrenergic$ blocker, phentolamine, as well as by the catecholamine depletion from adrenergic nerve terminals. Even in reserpinized strip, the exogenous norepinephrine-induced contraction in K-free Tyrode solution was rapidly suppressed by the addition of potassium ion. The results of this experiment suggest that K free contracture develops by norepinephrine release from adrenergic nerve terminals, while the relaxation of K-free contracture is induced by the activation of electrogenic Na-K pump.

• 상하수도학회지
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• 제18권2호
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• pp.174-180
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• 2004

This study is a fundamental research to test the applicability of abandoned eggshell as seed material for crystallization reaction. Eggshell was calcinated at $850^{\circ}C$ and ground to lesser than 0.42mm. The calcination characteristics of eggshell were examined by X-ray diffraction (XRD). The effect of initial calcium concentration, alkalinity, reaction temperature condition, seed dosage were studied by batch test. For the low concentration sample(P concentration is under 50mg/L), more than 90% of P can be removed. The effect of initial calcium concentration(0~120mg/L) was performed. At the result of the test, more than 50mg/L calcium concentration has high removal efficiency. Alkalinity effect was studied for synthetic solution(100mg/L initial P, 50mg/L calcium, 0.025% seed dosage) with 0~300mg/L bicarbonate alkalinities. For synthetic solution(100mg/L initial P, 50mg/L calcium, 100mg/L bicarbonate alkalinity, 0.025% seed dosage), the phosphorus concentration was examined with $10{\sim}35^{\circ}C$. In addition, calcinated eggshell was injected to swine wastewater to test the applicability to actual wastewater.

• 한국응용과학기술학회지
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• 제33권4호
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• pp.813-823
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• 2016

The purpose of this study was to investigate the effects of ionized calcium treatment on total bacterial cross-contamination of chicken carcass surface in the slaughtering process. The growth of Escherichia coli was strongly inhibited in a medium prepared by using a 0.5% ionized calcium solution. The total bacterial cross-contamination of chicken carcass surface and the scalding water was significantly increased as the number of scalding was increased (p<0.05). The total bacterial cross-contamination of chicken carcass surface reached a plateau without a further increase as scalding was performed consecutively for 10 or more times. The total bacterial cross-contamination of the scalding water was significantly increased as the number of scalding was increased (p<0.05). The total bacterial cross-contamination of chicken carcass surface of the chickens raised on a floor type farm was significantly higher than that of the chickens raised in a battery cages (p<0.05). The total bacterial cross-contamination of chicken carcass surface of the chickens raised on a floor type farm was significantly lower in the 0.5% ionized calcium solution treatment group than in the control group (p<0.05).

• 공업화학
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• 제31권1호
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• pp.103-107
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• 2020

본 연구는 대부분의 산업부산물에 다량 포함되어 있는 칼슘이온을 자원화하기 위한 것으로 칼슘이온의 추출 및 분리 조건 별 특성을 확인하였다. 칼슘 추출원으로 산화칼슘, 추출용제로 염산을 사용했으며, 추출용제의 농도에 따른 추출량 및 추출액의 pH 변화 특성을 분석하였다. 추출용제의 농도가 높아짐에 따라 추출량은 증가하는 반면 추출액의 pH는 일정하게 유지되는 경향을 나타내었다. 추출된 칼슘이온을 분리하기 위하여 산·염기성 용액 주입하였으며, 침전물 발생 여부와 침전물의 형태에 대하여 분석하였다. 산·염기성 물질 중 황산, 수산화나트륨 용액을 칼슘추출액에 주입하였을 때 침전물이 발생하였으며 각각 CaSO₄, Ca(OH)₂ 형태로 분리되는 것을 확인할 수 있었다.

• 폴리머
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• 제38권5호
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• pp.580-587
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• 2014

7 wt% alginate를 용액상태로 제조한 후 필름 메이커를 이용하여 필름 형태로 만든 후 3, 5 wt%의 $ZnCl_2$, $CaCl_2$ 수용액에 필름을 고화시킨 후 수세하여 상온에서 건조시켜 zinc calcium alginate 복합필름을 제조하였다. 필름의 특성을 조사하기 위하여 항균성, 수용해도, 팽윤도 및 점도, SEM, EDS 분석 등을 측정하였다. Zinc calcium alginate 복합필름은 $ZnCl_2$, $CaCl_2$ 함량이 증가할수록 용해저항성은 증가하였으며, 항균성 시험 결과, zinc alginate 필름뿐만 아니라 calcium alginate 필름에서도 두 균주(포도상구균, 대장균) 모두 우수한 항균력을 확인하였으며, 본 연구를 통해 복합필름의 물성개선의 가능성을 확인하였다.

• Preventive Nutrition and Food Science
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• 제15권4호
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• pp.282-286
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• 2010

To isolate a calcium-binding peptide from chlorella protein hydrolysates, chlorella protein was extracted and hydrolyzed using Flavourzyme, a commercial protease. The degree of hydrolysis and calcium-binding capacity were determined using trinitrobenzenesulfonic acid and orthophenanthroline methods, respectively. The enzymatic hydrolysis of chlorella protein for 6 hr was sufficient for the preparation of chlorella protein hydrolysates. The hydrolysates of chlorella protein were then ultra-filtered under 5 kDa as molecular weight. The membrane-filtered solution was fractionated using ion exchange, reverse phase, normal phase chromatography, and fast protein liquid chromatography to identify a calcium-binding peptide. The purified calcium-binding peptide had a calcium binding activity of 0.166 mM and was determined to be 700.48 Da as molecular weight, and partially identified as a peptide containing Asn-Ser-Gly-Cys based on liquid chromatography/electrospray ionization tandem mass spectrum.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.526-531
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• 2001

LD slag, that is, a by-product of steel making process, has been mainly used as land construction materials. Recently, the seashore application of LD slag was tried in Japan and Korea tut the reaction between LD slag and seawater was not studied yet. We tried to clarify the leaching reaction and/or mechanism of LD slag and the reaction between seawater and LD slag. We tried to apply these results to the decarbonization of seawater for seawater magnesia process. At first, LD slag was milled and classified into 5 grades, that is, (ⅰ)45${\mu}{\textrm}{m}$ under, (ⅱ)0.25~0.5mm (ⅲ)0.5~1mm(ⅳ)1~2mm, (ⅴ)2.36~3.35mm. These slags were leached in the distilled water. In case of 45${\mu}{\textrm}{m}$ under, the pH of the leached solution was over 12. The chemical analysis of leached solution showed that the $Ca^{+}$$^2$was main component and the S $i^{+}$$^4$was very low. On the other hand, the content of S $i^{+}$$^4$in leached solution was decreased with the increase of pH of this solution. The nearly pure calcium solution was made and the ultra high purity MgO could be made with this calcium solution. The leaching behavior of LD slag was different between the fine particle and coarse particle. The calcium was leached by bulk dissolution in the coarse particle and by surface controlled reaction in fine particle. The leaching rate was slow in coarse particle and fast in fine particle. Therefore, the high pH solution, that is, over 12, was obtained in fine particle.cle.e.

• KSBB Journal
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• 제17권3호
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• pp.314-316
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• 2002

염소계 소독제인 TICA (Trichloro isocyanuric acid)와 calcium hypochlorite에 의한 대장균의 사멸특성을 비교하기 위하여, 접촉시간과 소독제의 농도를 달리 하여 소독력을 측정하였다. 소독제의 농도는 4∼16 ppm으로 하고 접촉시간은 30sec, 1, 2, 4, 8 min으로 하여 각각 측정하였다. TICA 12 ppm에서 4초만에 90%의 대장균이 사멸하였다. 하지만 calcium hypochlorite 12 ppm에서는 390초 동안 접촉시켜야 같은 사멸효과를 얻을 수 있었다. 또한 햇빛에 의한 소독력의 감소를 측정한 결과 TICA는 햇빛에 6시간동안 노출되어도 소독력이 유지되었으나, calcium hypochlorite는 햇빛에 1시간만 노출되어도 소독력이 급격히 감소하기 시작하여 4시간만에 소독력을 완전히 상실하였다. 본 실험조건 하에서는 TICA가 calcium hypo-chlorite보다 대장균에 대한 사멸률 및 소독지속력이 모두 우수하게 측정되었으며, 또한 본 연구결과로부터 동일한 소독 효과를 얻기 위한 소독제별 최적조건을 비교 제시하였다.

• International Journal of Advanced Culture Technology
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• 제10권1호
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• pp.284-293
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• 2022

After extracting the calcium component from the KR slag and the converter slag using ammonium chloride solution, the extract was reacted with carbon dioxide to synthesize precipitated calcium carbonate (PCC). In order to understand the effect of ultrasonic waves on calcium extraction from slags and calcium carbonate synthesis, the efficiency of calcium carbonate synthesis according to the with or without of ultrasonic waves was analyzed. The synthetic efficiency of PCC was investigated according to various experimental conditions, and the synthesized calcium carbonate was analyzed using XRD and SEM. In both slags, the amount of PCC decreased as the reaction temperature increased. The pH at the end of the experiment capable of synthesizing the maximum PCC in the carbonation reaction was 7 (irradiated with ultrasound) and 8 (irradiated without ultrasound), respectively. Because the pH of the extraction filtrate is different when irradiated with or without ultrasound, the pH was adjusted to 9 by injecting an additive (10 M NaOH) before the carbonation experiment, and then the experiment was performed. When calcium was extracted from KR slag, the crystal phase appeared as calcite regardless of the pH at the end of the experiment. However, when calcium was extracted from the converter slag and the pH was set to 7 at the end of the experiment, the crystal phase of PCC appeared as a mixture of calcite and vaterite.

• 한국세라믹학회지
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• 제11권2호
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• pp.11-16
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• 1974

Korean Yung-il bentonite was treated with potassium chloride, zinc chloride, calcium chloride, ferric chloride, or chromic chloride solutions respectively varying their concentration, treating temperature and treating time. The adsorbabilities of methylene blue on these pretreated bentonite were investigated. In the case of treatment with potassium chloride solution, the improvement of the adsorbahility of methylene blue on the products was observed, and in the best result the adsorbability was 1.6 times better than that on the original bentonite. With zinc chloride solution, the optimum adsorbability was a value of 1.7 times better than that on the original bentonite. With ferric chloride, chromic chloride or calcium chloride solution, slight improvement of the adsorbability was observed.