• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.1
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• pp.127-128
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• 2003

본 연구는 퇴비화 과정 중 난용성 인산의 가용화와 무기태 인산의 변화를 알아보기 위하여 수행하였다. 비료와 퇴비중의 인산형태는 다른 성분들보다 토양에 흡착 또는 고정되거나 불용화 되는 양이 많아 작물의 흡수량이 적다. 시비된 인산의 흡수율은 낮고, 그 대부분은 난용화되기 때문에 토양에 축적되거나 세탈과 용탈에 의해 수질을 오염화시키는 주원인이 되고 있다. 퇴비화 과정중의 인산형태별 함량변화를 분석조사하여 작물에 시비되는 인산비료와 퇴비의 시용량을 적절하게 조절하여 인산의 과잉 시비량을 저감시키기 위한 연구이다. 돈분을 원료로 한 퇴비화 과정에서 단계별로 퇴비시료를 채취하여 총인산(T-P), 유효인산(Avail. -P)과 무기태인산분획별(Ca-P, Al-P, Fe-P)로 분석한 결과는 다음과 같다. 퇴적더미의 초기부피는 570L였으며, 약 2개월간의 퇴비화를 통해서 시료채취와 미생물등의 분해작용으로 최종부피는 430L정도로 감소하였다. 이는 초기의 부피보다 25% 감소하였다. 퇴적더미의 분해로 인한 용적밀도의 변화를 고려하면, 총인산 함량은 초기 약 17,500mg/kg에서 최종시료는 22,500mg/kg로 증가되었다. 또한 퇴비화가 진행됨에 따라 인산의 가용태가 증가하는 결과를 보였으며, 초기의 유효인산이 4,500mg/kg에서 최종시료에서는 8,900mg/kg으로 증가되었다. 그리고 무기태 인산분획별 인산의 형태별 변화를 조사한 결과, 퇴비화 과정 중 Ca-P의 경우 pH와의 중요한 상관관계를 갖고 있었다. 유기물분해를 통해 유리된 인산과 Ca은 난용태로 전환되는데, 초기의 약 10일 동안 Ca-P의 감소원인은 pH의 감소로 인한 Ca이 유리되는 정도가 낮기 때문인 것으로 해석된다. 초기 Ca-P형태의 인산함량은 11,900mg/kg으로 Fe-P와 Al-P보다 많았다. 또한 퇴비화가 안정화되어 부숙된 최종시료의 무기태 인산분획물 중 Ca-P는 18,000mg/kg로 증가하였으며, Ca-P>Al-P>Fe-P의 순 이었다. 그러나 Al-P와 Fe-P 형태의 무기태인산은 초기의 함량비율보다 다소 감소한 결과를 보였다. 결론적으로, 퇴비화과정 중 단계별 인산함량의 형태전환을 분석한 결과 총인산의 함량은 퇴비화가 안정화될수록 부피감소로 인한 인산함량이 증가하는 경향을 보였지만, 유기물질의 분해로 인한 원료내 인산의 형태가 불용태와 난용태에서 가용태 인산으로 전환되는 것을 도출하였다. 또한 무기태 인산분획물에서는 Ca-P 인산형태가 퇴비화가 진행될수록 증가한다는 결과를 얻었으며, Fe-P와 Al-P는 분해된 유기물의 킬레이트작용으로 감소되었다고 판단되며, 그 존재형태가 경쟁적임을 알 수 있었다. 따라서 화학비료와 퇴비의 시용이 병행될 경우에는 퇴비의 가용태 인산함량뿐만 아니라 무기태 인산의 함량을 분석한 후 인산질비료의 시비량을 조절해야할 것으로 판단된다.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.2
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• pp.245-251
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• 2018

Objective: This study was conducted to determine the effects of dietary maifanite supplementation and fecal collection method on the apparent total tract digestibility (ATTD) of calcium (Ca) and phosphorus (P) and blood parameters in growing pigs. Methods: Thirty-six growing barrows (Duroc${\times}$Landrace${\times}$Yorkshire; $27.0{\pm}2.6kg$) were allotted to six dietary treatments with 6 pigs per treatment according to body weight in a completely randomized design. The experimental treatments were: i) Low Ca+cornstarch (2.25%), ii) Low Ca+maifanite (2.25%), iii) Medium Ca+cornstarch (1.42%), iv) Medium Ca+maifanite (1.42%), v) High Ca+cornstarch (0.64%), and vi) High Ca+maifanite (0.64%). Feces were collected by the total collection (TC) and indicator method (IM). At the beginning and the end of the experiment, blood samples were collected from each pig. Results: For the TC method, there were no difference in Ca intake, fecal Ca output, Ca retention and the ATTD of Ca between cornstarch and maifanite diets at the same dietary Ca level. However, urinary Ca excretion was lower (p = 0.01) in pigs fed low Ca diets without maifanite supplementation compared with other dietary treatments. Dietary maifanite supplementation had no effect on the P metabolism in growing pigs. For the IM method, there was no difference in Ca digestibility between cornstarch and maifanite diets at the same dietary Ca level. The ATTD of P was greater (p<0.01) in pigs fed the high Ca diet with maifanite supplementation compared with the high Ca diet with cornstarch treatment. Dietary inclusion of maifanite had no effect on blood parameters in growing pigs. Conclusion: Dietary maifanite supplementation had no effect on the ATTD of Ca and P and serum parameters in growing pigs. The IM resulted in lower digestibility values than the TC method.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.2
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• pp.278-286
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• 2008

Many studies regarding Casein phosphopeptides-amorphous calcium phosphate(CPP-ACP) have demonstrated the remineralization ability on the demineralized enamel surface. A question is still remained that how deep can the calcium (Ca) and phosphorus (P) ions supplied by the CPP-ACP paste penetrate into the enamel subsurface. The aims of this study were to measure the penetrating depth of Ca and P ions in the demineralized human enamel in vitro, and were to determine the amount and depth of Ca and P ions according to the duration. The amount and depth of Ca and P ions were measured by microscopic observation with Field Emission Scanning Electron Microscopy (FE-SEM; LEO SUPRA 55, Carl Zeiss, Germany) and Energy Dispersive X-ray Spectrometer (EDS; GENESIS 2000, EDAX, USA: Linescan of Calcium and Phosphorus). Freshly extracted four human 1st premolars were obtained from the Dept. of Pediatric Dent., Kyung Hee Univ. Buccal surfaces of the 1st premolars were covered with nail varnish to form a window on the middle third of buccal surface. All of the teeth with enamel windows were immersed in a solution of 0.1 M lactic acid, Carbopol C907 (carboxypolymethylene BF Goodrich, Cleveland, OH, USA) at pH 4.8, and then incubated for 7 days. Each tooth crown was sawn in half through the midline of buccal window along the long axis of premolar. The four blocks of premolars were immersed in a 10-times diluted solution of CPP-ACP paste (Tooth Mousse, GC Corp., Tokyo, Japan) for 1, 2, 3 and 5 weeks while the rests were immersed in a placebo solution (distilled water) for the same duration. Each specimen was embedded in epoxy resin, and was sectioned perpendicular to the window, using a water-cooled diamond blade saw. The spectrum density indices of Ca and P were measured in the sound, de- and remineralized enamels by FE-SEM and EDS. The Student's t test was performed to compare the Spectrum Density Indices (SDI) of sound, re-and demineralized enamels, and to compare the differences among the durations. Followings are the conclusion : 1. The penetration depth of the remineralizing ions (Ca & P) of CPP-ACP paste is related to the depth of demineralized enamel (approximately $1050{\sim}1350{\mu}m$). It is revealed that the penetration depth of both ions reaches full thickness of decalcification and even slightly into the sound enamel. 2. The Ca & P levels of remineralized enamels in 1, 2 weeks were significantly higher than those of the sound enamels (p<0.05). 3. No statistically significant difference of Ca & P levels was found in relation with the increasing duration of remineralization (p>0.05).

• Biomolecules & Therapeutics
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• v.29 no.6
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• pp.630-636
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• 2021

Eupafolin, a constituent of the aerial parts of Phyla nodiflora, has neuroprotective property. Because reducing the synaptic release of glutamate is crucial to achieving pharmacotherapeutic effects of neuroprotectants, we investigated the effect of eupafolin on glutamate release in rat cerebrocortical synaptosomes and explored the possible mechanism. We discovered that eupafolin depressed 4-aminopyridine (4-AP)-induced glutamate release, and this phenomenon was prevented in the absence of extracellular calcium. Eupafolin inhibition of glutamate release from synaptic vesicles was confirmed through measurement of the release of the fluorescent dye FM 1-43. Eupafolin decreased 4-AP-induced [Ca²⁺]_i elevation and had no effect on synaptosomal membrane potential. The inhibition of P/Q-type Ca²⁺ channels reduced the decrease in glutamate release that was caused by eupafolin, and docking data revealed that eupafolin interacted with P/Q-type Ca²⁺ channels. Additionally, the inhibition of calcium/calmodulin-dependent protein kinase II (CaMKII) prevented the effect of eupafolin on evoked glutamate release. Eupafolin also reduced the 4-AP-induced activation of CaMK II and the subsequent phosphorylation of synapsin I, which is the main presynaptic target of CaMKII. Therefore, eupafolin suppresses P/Q-type Ca²⁺ channels and thereby inhibits CaMKII/synapsin I pathways and the release of glutamate from rat cerebrocortical synaptosomes.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.4
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• pp.327-334
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• 2016

In order to compare phosphorus (P) behavior of livestock manure compost (LMC) and chemical fertilizer (CF) applied to the sea-reclaimed land soils, incubation experiments were conducted for five weeks. Four soils differing textural classes, sandy loam and clay loam, and electric conductivity (EC) value, high and low, were applied with CF and LMC. LMC was applied at the level of 0, 1, 2, and 3% on the soil weight basis and CF was applied at the same levels of P as LMC. The results showed that increase of P application rate of CF and LMC led to linearly increase available $P_2O_5$ and $0.01M\;CaCl_2$ extractable P contents regardless of soil texture and EC. However, 0.01M $CaCl_2$ extractable P from soil applied with CF was significantly higher than with LMC. Correlation analysis between $0.01M-CaCl_2$ extractable P and fractionated P by different extraction methods showed that $0.01M-CaCl_2$ extractable P positively correlated with KCl-P (soluble and exchangeable P) and HCl-P (Ca and Mg bound P). However, NaOH-P (Fe and Al bound P and organic P) and residual P was adverse. The amount of NaOH-P significantly influenced to the amount of 0.01M $CaCl_2$ extractable P of CF and LMC in the soils. The application of LMC at sandy loam soil could be carried out in the consideration of nutrient leaching and crop uptake.

• Korean Chemical Engineering Research
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• v.54 no.4
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• pp.548-554
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• 2016

In this study, semi-aqueous solutions containing carboxylic acids such as oxalic acid (OA), lactic acid (LA) and citric acid (CA) were formulated for the removal of copper etching residues produced at the interconnection process, and their characteristics were analyzed. Carboxylic acids in the solutions were apt to form various copper complexes according to the value of pH. Semi-aqueous solution containing 10 wt% CA showed the lowest etching rate of copper in the range from pH2 to pH7 and the highest selectivity in the range of pH 2 to pH 4. However, the cleaning solution containing 10 wt% LA revealed the superior selectivity at the range from pH 5 to pH 7. Appropriate selection of carboxylic acid should be required to improve the performance of cleaning solution. In the case of CA, the etching selectivity of copper oxide complex to copper was increased with the concentration of CA in the solution, when the solutions contain over 5 wt% CA, the copper interconnection layer has a metallic copper surface more than 88% in the area. The result shows that CA contained semi-aqueous solution has a relatively good cleaning ability.

• Korean Journal of Poultry Science
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• v.20 no.3
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• pp.133-140
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• 1993

A study was conducted to investigate the concentrations of Ca, P and ash in metatarsal bone of broiler chicks exposed to UV light in different Interval. Day-old Hubbard broiler chicks (199＝10 control＋3 irradiation interval $\times$ 9 elapsed time $\times$ 7 replicate) were fed vitamin D3 deficient diet for 3 wk in a windowless subdued-light room and exposed to 297 nm UVB light by 0.068 mJ/$\textrm{cm}^2$ three times In 0, 12 or 24 h interval. The metatarsal bones were taken at 0, 6, 12, 18, 24, 48, 96, 144 or 240 h after last irradiation, separated from adhering tissue, ether extracted, dried and ashed. The Ca concentration was measured by atomic absorption spectrophotometry and P by ammonium metavanadate colorimetry. When the birds were continuously exposed to UVB light for 30 min without interval, the Ca content in metatarsus increased gradually according to the time after irradiation and reached the highest value 16.75% at 240 h after exposure. The P content also increased gradually until 144 h, where it was 9.75%. The ash content in metatarsus increased continuously until 240 h, the final time in this research, where 42.75% was shown. As 10 min three times irradiation in 12 h interval was applied to the chicks, the metatarsal Ca presented a small peak(13.31%) at 12 h after irradiation and a large peak(16.91%) at 144 h. P content showed a small peak(7.18%) at 12 h and a large level(8.34%) at 240 h. Ash content increased continuously until 240 h, where it was 46.53%. The small peaks in Ca and P concentration were thought to be derived from preirradiation at 12 and 24 h before final irradiation for 10 min. When 24 h interval system was treated, the peak value of Ca content(24.18%) occurred earlier(96 h) than those in 0 and 12 h interval systems. P content also showed the maximum value at 96 h(7.29%). Ash content presented an increasing trend until 240 h, where 45.75% was appeared. In respecting the method of UVB irradiation, the peak value of Ca content in metatarsus appeared earlier in 24 h interval system than in other systems. Meanwhile the ash contents in metatarsus of birds exposed to UVB light in 12 and 24 h interval procedures were higher than those in 0 h interval one. Therefore, it was concluded that a daily 10 min irradiation of UVB light would be desirable for increasing the Ca and ash content in metatarsus of brolier chicks.

• Journal of Nutrition and Health
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• v.32 no.1
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• pp.30-39
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• 1999

This study was designed to investigate the effect of Ca supplementation of 1,000mg per day for 53 weeks on lipid, Na, and K metabolism and on blood pressure in postmenopausal women. The subjects were 12 healthy women aged from 60 to 70 years. They were divided into two groups : the placebo(control group) and the Ca supplemented(1,000 mg/day) group(Ca group). Metabolic studies were conducted twice in the 1st and the 53rd weeks. The results were as follows : Serum triglyceride, total cholesterol and LDL-choesterol levels tended to be decreased after the experiment. Serum VLDL-cholesterol lowering effect was observed with Ca supplementation(p<0.05), and also the significantly elevated HDL/(LDL+VLDL) ratio in Ca supplemented subjects whose average Na intake was as high as 4.9g per day. This phenomena was accompanied with increased Na retention and increased Na excretion in feces, but with decreased urinary Na in Ca supplemented group. However, considering much higher Na reteniton in the control group at the end of experiment(control va Ca ; 1272.3mg vs 732.9mg), Ca supplementation may have some beneficial effects on Na blance. Serum aldosterone level increased significantly in the Ca group after the exsperiment(p<0.05). With these normotensive subjects, there were no level increased significantly in the Ca group after the experiment(p<0.05). With these normotensive subjects, there were no pronounced effect of Ca supplementation on blood pressure, however, decrease in diastolic blood pressure were observed at the 14th week and end of the experiment(p<0.05). In summary, the Ca supplementation on postmenopausal Koran women appears to exert a desirables effect on blood lipid patterns related to the coronary heart diseases and to be beneficial in controlling diastolic blood pressure. Further studies with hypertensive or/and hyperlipidemic subjects are required to clarify the effect of Ca supplementation in Koreans.

• Journal of the Korean Ceramic Society
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• v.30 no.11
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• pp.905-910
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• 1993

$\alpha$-tricalcium phosphate($\alpha$-TCP) powders were synthesized and their hydration properties were investigated in Tris. solution. Two kinds of $\alpha$-TCP powder samples were prepared; the one is reaction product of CaHPO4.2H2O and CaCO3, and another is that of hydroxyapatite(HAp) and $\beta$-Ca2P2O7. They were satisfied with Ca/P mole ratio 1.5 and were heated at 150$0^{\circ}C$ for 5 hours. In the hydration of $\alpha$-TCP samples the powder which was synthesized from HAp and $\beta$-Ca2P2O7 was hydrated faster than that from CaHPO4.2H2O and CaCO3. The hydration reaction of $\alpha$-TCP powder transformed rapidly into HAp accompanying setting and hardening. It was realized that the hydration reaction of $\alpha$-TCP was due to the solution-precipitation mechanism and the hydrates from the reaction were Ca-deficient HAp having funtional group HPO42-.

• Corrosion Science and Technology
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• v.4 no.4
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• pp.121-129
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• 2005

Basic design concept of the future steel structure requires environmental compatibility and maintenance free capability to minimize economic burdens. Recent trends in alloy design for advanced weathering steel include addition of various alloying elements which can enhance formation of stable and protective rust layer even in polluted urban and/or high $Cl^{-}$ environment. The effects of Ca, Ni, W, and Mo addition on the corrosion property of Ca-modified weathering steel were evaluated through a series of electrochemical tests (pH measurement and electrochemical impedance spectroscopy: EIS) and structural analysis on rust layer formed on the steel surface. Ca-containing inclusions of Ca-Al-Mn-O-S compound are formed if the amount of Ca addition is over 25 ppm. Steels with higher Ca content results in higher pH value for condensed water film formed on the steel surface, however, addition of Ni, W, and Mo does not affect pH value of the thin water film. The steels containing a high amount of Ca, Ni, W and Mo showed a dense and compact rust layer with enhanced amount of ${\alpha}-FeOOH$. Addition of Ni, W and Mo in Ca-modified weathering steel shows anion-selectivity and contributes to lower the permeability of $Cl^{-}$ ions. Effect of each alloying element on the formation of protective rust layer will be discussed in detail with respect to corrosion resistance.