• 한국토양비료학회지
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• 제46권5호
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• pp.308-312
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• 2013

The monitoring of chemical dynamic changes in controlled horticultural lands is very important for agricultural sustainability. Field monitoring was performed to evaluate the soil chemical properties of 200 controlled horticultural soil samples in Gyeongnam province every 4 years from 2000 to 2012. Soil chemical properties such as pH, amount of organic matter, available phosphate, nitrate nitrogen, and exchangeable potassium, calcium, magnesium, and sodium were analyzed. The amount of exchangeable calcium and soil pH were significantly higher in 2012 than in 2000. In 2012, the frequency distribution for values of pH, organic matter, available phosphate, and exchangeable potassium, calcium, and magnesium that were within the optimum range was 16.0%, 22.5%, 11.5%, 3.5%, 2.5%, and 5.0%, respectively. Especially, available phosphate and exchangeable calcium were excess level with portions of 76.0% and 96.5%, respectively. These results indicated that a balanced management of soil chemical properties can reduce the amount of fertilizer applied for sustainable agriculture in controlled horticultural lands.

• Macromolecular Research
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• 제17권6호
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• pp.445-447
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• 2009

• 동아시아식생활학회지
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• 제12권5호
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• pp.379-387
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• 2002

본 연구는 여러 가지 조리 및 영양 생리작용을 가진 유기산을 닭뼈에 이용하여 조리할 때 산의 종류와 조리 시간에 따른 칼슘, 마그네슘, 인의 용출량에 미치는 영향을 조사하였으며 그 결과는 다음과 같다. 1. 칼슘, 마그네슘, 인의 용출량은 산의 농도가 높을수록 증가하였고, 끓이는 시간에 비례하여 증가하였다. 같은 농도에서는 초산의 첨가군보다 구연산, 사과산의 첨가군이 많이 용출되었다. 2. 단백질과 총 유리아미노산의 용출량도 무기성분의 용출과 같은 경향을 나타내었다. 이상의 결과는 유기산을 첨가하여 12시간 끓이면 무기성분뿐만 아니라 단백질, 아미노산의 용출량이 증가하는데, 이것은 유기산의 첨가로 인하여 가용화 상태가 된 뼈가 끓임으로써 한층 더 연해져 뼈 중의 성분이 용출되기 쉽다는 사실을 확인할 수 있었다.

• 한국농공학회지
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• 제12권4호
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• pp.2084-2089
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• 1970

간척지의 토양개량제로서 효과가 있을 것으로 기대되는 여러종류의 석회질 물질을 비교 시험하여 그 효과를 밝히고저 강화간척지 시험포장에서 실시한 결과는 다음과 같다. 1. 정조수량은 Ca-Humate 1.0% 구에서 제일 많았고 다음이 생고, 석고, 소석회의 순으로 되었다. 2. 석회나 유기물을 시용함으로서 증수를 가져 온 것은 수량구성 요인인 주당수수(株當穗數) 수당입수(穗當粒數), 천립중(千粒重), 등숙율(登熟率) 등을 모두 증가 시켰기 때문이다. 3. 유기물이나 석회를 시용함으로서 입단형성을 증가시켜 수도생육을 양호하게 하였다. 4. 간척지 토양을 개량하기 위하여서는 석고나 소석회 및 생고를 따로따로 분리해서 시용하는 것도 좋지마는 Ca-Humate와 같이 석회를 유기물과 함께 시용하는 것도 효과가 좋다.

• 한국세라믹학회지
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• 제21권2호
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• pp.143-148
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• 1984

In this study we mainly dealt with the effects of organic retarder(calcium lignosulfate) on the early hydration process of clinker minerals. From a consideration of the hydration process of tricalcium silicate $(C_3S)$ tricalcium silicate $(C_3S)$-tricalcium aluminate $(C_3A)$ tricalcium silicate $(C_3S)$-tetracalcium aluminof-errite $(C_4AF)$ systems with calcium lignosulfate the following results were obtained. 1. when 0.25wt% of CLS was added to $C_3S$ the hydration process was progressed normally but adding of 0.5wt% its hydration was greatly retarded. 2. The hydration of $C_3S$-$C_3A$ system was progressed normally up to 0.5wt% but by adding gypsum its hydration was retarded slightly. 3. The hydration of $C_3S$-$C_4AF$ system was greatly retarded even with 0.25wt% of CLS but by adding gypsum its hydration process was recovered normally.

• Membrane and Water Treatment
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• 제9권3호
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• pp.163-172
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• 2018

This study investigated the effect of organic matter on the precipitation of struvite and calcium phosphate for phosphorus recovery from synthetic dairy wastewater. Batch precipitation experiments were performed to precipitate phosphorus from solutions containing $PO_4{^{3-}}$ and $NH_4{^+}$ by the addition of $Mg^{2+}$ and $Ca^{2+}$, separately, at varying pH, Mg/P and Ca/P molar ratios, and organic matter concentrations. Soluble total organic solids exhibited more inhibition to precipitation due to potential interaction with other dissolved ionic species involved in phosphorus precipitation. Xylan with low total acidity only exhibited significant inhibition at very high concentrations in synthetic wastewater (at up to 100 g/L). No significant inhibition was observed for Mg and Ca precipitation at relatively lower concentrations (at up to 1.2 g/L). MINTEQ simulations show that dissolved organic matter (DOM) as humic substances (HS) can cause significant inhibition even at relatively low concentrations of 0.165 g/L fulvic acid. However, scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis suggested that xylan altered the crystal structure of both precipitates and had caused the formation of smaller sized struvite crystals with slightly rougher surfaces This could be due to xylan molecules adhering on the surface of the crystal potentially blocking active sites and limit further crystal growth. Smaller particle sizes will have negative practical impact because of poorer settleability.

• 한국축산식품학회지
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• 제30권4호
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• pp.685-694
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• 2010

The present study investigated the combined effects of modified atmosphere packaging (MAP) and organic acid salts on the quality and shelf-life of Hanwoo ground beef patties. The ground beef containing 500 ppm of ascorbic acid was prepared with air-packaging (Air-P), high oxygen-MAP (70% $O_2$+30% $CO_2$/OxyMAP), and nitrogen-MAP (100% $N_2$/NitroMAP), in combination with organic acid salts (1500 ppm of sodium acetate and 500 ppm of calcium lactate). The samples were stored for 11 d at $5^{\circ}C$. The pH value of ground beef patties decreased during storage in all the treatments. The ground beef patties with organic acid salts showed relatively higher level of pH during storage compared with non-added patties (p<0.05). Lipid oxidation was accelerated in OxyMAP while it was delayed in NitroMAP treated with organic acid salts. Nitro-MAP treated with organic acid salts was effective in stabilizing the color characteristics of lightness (CIE $L^*$) and redness (CIE $a^*$) during storage. Oxygen content in MAP was shown to be a more important factor affecting color stability and lipid oxidation of ground beef than organic acid salts. The aerobic and anaerobic bacterial counts were reduced both in OxyMAP and NitroMAP (p<0.05), and the lactic acid bacteria was inhibited by Oxy-MAP (p<0.05). Coliform bacteria decreased during storage as pH value was decreased in all treatments. According to the sensory evaluation, the ground beef patties in NitroMAP showed the best quality among all treatments during storage. Therefore, Hanwoo ground beef patties added with sodium acetate and calcium lactate and packed with NitroMAP showed better quality characteristics than other treatments. This packaging method is recommended and could be utilized for packaging hanwoo ground beef patties for improving quality and extending shelf-life.

• 한국축산식품학회지
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• 제33권4호
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• pp.515-521
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• 2013

In this study, we examined the effects of organic types of calcium derived from oyster shell (OS-Ca) and nano-calcium (Nano-Ca) on the bio-availability and physiological responses associated with bone health in ovariectomised rats. Increased body weight, which is one of the physiological effects of ovary removal, was significantly recovered by Nano-Ca treatment (p<0.05). The reduced calcium level in the liver in ovariectomised rat was increased significantly with OS-Ca and Nano-Ca treatment (p<0.05), suggesting improved calcium bio-availability. Alkaline phosphatase (ALP), osteocalcin, and deoxypyridinoline (DPD) were analysed as biochemical markers of bone metabolism and health in the presence or absence of OSCa and Nano-Ca. ALP, osteocalcin, and DPD levels increased following ovary removal and tended to decrease after treatment with Nano-Ca, indicating that Nano-Ca induces favourable bone metabolism. This result was reflected in the recovery of bone mineral density (BMD) and bone mineral content (BMC) of the femur after Nano-Ca treatment following ovary removal. Taken together, our data show that the tested calcium treatments, especially using Nano-Ca, enhanced the bioavailability or absorption of calcium and positively affected bone metabolism in ovariectomised rats.

• 식물병연구
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• 제21권3호
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• pp.215-221
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• 2015

본 연구는 유기농 생강재배지에서 발생한 생강 뿌리썩음병을 헤어리벳치와 난각칼슘+훈탄을 혼합 처리하여 방제하고자 하였다. 생강의 잎이 황화되고 식물체가 시드는 생강 근경썩음병의 병징은 화학비료 처리구에서 7월 1일부터 시작되었다. 수확기인 10월 2일에 생강 근경썩음병이 더욱 진전되어 생강의 줄기가 갈변하고 식물체가 고사하여 36.7-43.0%의 높은 발병율을 보였다. 반면에 헤어리벳치+훈탄+난각칼슘 처리구는 9월말까지 근경썩음병이 전혀 발생되지 않았고 10월 초순까지 발생이 지연되어 1.3-1.7%의 매우 낮은 발병율을 보였다. 토양내 Na, Fe, Cu 함량은 헤어리벳치+훈탄+난각칼슘 처리에 의해 처리 전보다 감소하였으나 유기물 함량은 31.6%로 시험 전보다 2배 증가하였다. 토양내 Pythium sp.의 밀도는 헤어리벳치+훈탄+난각칼슘 처리구($0.3-2.0{\times}10^3cfu/g$)에서 낮았으나, 화학비료 처리구($12.0-12.3{\times}10^3cfu/g$)에서 유의적으로 높았다. 따라서, 유기농 생강 재배지에 헤어리벳치를 녹비작물로 재배하고 토양 개량제인 훈탄과 난각칼슘을 토양에 처리하면 생강의 고질적인 병인 생강 근경썩음병을 효과적으로 방제할 수 있을 것으로 사료된다.

• KSBB Journal
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• 제21권3호
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• pp.199-203
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• 2006

본 연구에서는 에탄올 농도에 따른 모델용액과 발효액에서 여러 유기산들의 침전거동을 조사하였다. 발효액에서 에탄올의 농도가 높을수록 Ca(LA)2의 침전양이 많았다. Ca(LA)2의 침전효과는 발효액 내에서도 비슷하게 관찰되었다. 모델용액이나 발효액과의 혼합물 대비 30%(v/v)로 에탄올을 첨가하였을 때 젖산분리 공정의 불순물로 존재하는 다른 organic salt들의 침전율도 높았다. 따라서 전체 젖산회수공정의 효율에 대한 연구에서는 에탄올과 발효액의 혼합비율을 20%로 하였다. 반응증류시 일정 온도 이상에서는 젖산회수율이 차이나지 않았다. 에탄올이 첨가된 발효액에서는 대조군과 비교하여 최종젖산 회수율이 38.9% 증가하였다. 또한, 다른 유기산들을 포함한 회수액에서의 순도도 99.7%에 달하였다. 이러한 젖산 회수율의 증가는 owning-out crystallization에 의한 Ca(LA)2의 용해도 감소에 기인한 것으로 판단한다. 본 실험 이후에 더 높은 젖산 회수와 정제 효율을 얻기 위해서는 에탄올의 첨가에 따른 유기산의 거동과, 반응증류에서 사용되는 triethylamine의 양과 반응시간에 대한 검토가 필요할 것으로 사료된다.