• 한국물환경학회지
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• 제32권5호
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• pp.458-464
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• 2016

This study evaluated the dewatering efficiency of inorganic dehydrating agents that contain oyster shells. A filter press dehydrator was used for this study. The experiments were performed by the single injection of calcium-based chemicals, the single injection of oyster shells, and the mixed injection of oyster shells and calcium-based chemicals. The moisture content of the dewatered cake generated after dehydration confirmed that the best dewatering efficiency was found at the mixing ratios of CaCO₃ to sludge, oyster shell to sludge, and inorganic dehydrating agent to sludge of 3:1, 10:1, and 1.5:2.5:1, respectively. The moisture contents exhibited less than 58% when the injection mixing ratio of inorganic dehydrating agent to sludge was 1.5:2.5:1. From EPS, SEM, and EDX analysis, it was found that the calcium adsorbed on the sludge surface could reduce extracellular polymeric substances (EPSs) and enhanced the dewaterbility. Based on the above results, it is considered possible to apply inorganic dehydrating agents containing recycled oyster shells in sludge dewatering in order to reduce sludge.

• 한국수산과학회지
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• 제34권5호
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• pp.483-487
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• 2001

갑오징어 가공 부산물인 갑으로부터 유용 칼슘을 효율적으로 추출하기 위하여 소성처리 ($800^{\circ}C$, 2시간), 고온가압처리 ($121^{\circ}C$, 10시간) 및 초음파처리 ($60^{\circ}C$, 10시간)와 같은 전처리 방법에 대하여 검토하였다 소성처리에 의한 칼슘 추출 분말의 경우 백색이었으나, 기타 추출법으로 처리되어진 칼슘 분말의 경우 연노랑색을 나타내었다 소성처리에 의한 갑 분말의 칼슘함량은 $70.5\%$로 원료 및 다른 전처리 방법에 비하여 약 2배정도 증가하였다 전 처리 방법에 따른 칼슘의 가용화율은 원료에 비하여 초음파처리 및 고온가압처리의 경우 약간 감소하였으나, 소성처리한 경우 약 22배가 증가하였다. 이상의 칼슘제로서 가장 중요한 품질지표인색조, 칼슘 가용화율 및 순도 둥으로 미루어 보아 전처리 방법으로는 소성처리가 가장 우수하였다. 소성처리 시료를 RED 상분석한 결과 주성분은 산화칼슘이었다. 그러나, 소성처리에 의한 칼슘 추출 분말의 경우 pH가 12.9로 강알칼리를 나타내어 안전성 측면에서 식품품질 개선제 둥으로 사용하기에는 다소 문제가 있었다. 이상의 결과로 미루어 보아 갑오징어갑으로부터 칼슘을 추출하는 방법으로는 소성처리가 가장 우수하였으나, 강알칼리로 인해 식품 품질개선제 등과 같이 효율적으로 이용하기 위하여는 반드시 중성부근의 pH로 조정이 이루어져야 하리라 판단되었다.

• 대한수의학회지
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• 제36권3호
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• pp.709-718
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• 1996

This experiment was carried out to clarify the effect of lead poisoning on the lead and essential trace elements homeostasis of tissues in rats. Fifty female Wistar rats, 7 weeks old, were divided into four experimental groups(B, C, D, and E) and a control(A). The four experimental groups received diets contaminated artificially with 10 (B group), 100 (C group), 1,000 (D group) and 5,000 (E group) ${\mu}g/g$ of lead as lead acetate, respectively. The control group received normal diet. Rats were necropsied on the 4th or 8th week of experimental periods and heart, liver, spleen, kidney, muscle, lung and hair were taken. The tissues were analysed for lead, copper, zinc, iron and calcium content by atomic absorption spectrophotometry. From these experiments following results ware obtained ; In C group, lead content of the heart, liver, kidney and hair were significantly increased both on the 4th and 8th week of experiment. In D and E group, lead content of all tissues including heart, liver, spleen, kidney, muscle, hair and lung were significantly increased in accordance with the lead contamination both on the 4th and 8th week of experiment. In C group, copper content of tissues were significantly increased in the heart, liver, kidney and lung on the 4th week and all tissues on the 8th week of experimental periods. In D and E group, copper content of the liver were significantly increased both on the 4th and 8th week of experiment. But the copper content of tissues were gradually decreased compared with C group in accordance with the lead contamination. Especially the content in spleen, heart or kidney were significantly decreased compared with the control group. The zinc content of kidney, heart, or spleen were decreased in D and E groups whereas the iron and calcium content showed no significant change.

• 한국토양비료학회지
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• 제14권3호
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• pp.137-145
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• 1981

화강암(花崗巖)에서 유래(由來)된 신개지토양(新開地土壤)에서 석회(石灰), 가리(加里) 및 붕소시용(硼素施用)이 상치와 그 후작대두(後作大豆)에 미치는 상호효과(相互效果)를 주로 식물영양면(植物榮養面)에서 비교검토(比較檢討)한 결과(結果)를 요약(要約)하면 다음과 같다. 1. 석회시용(石灰施用)은 상치 및 대두(大豆)에 현저한 증수효과(增收效果)가 있었고 대두엽중(大豆葉中) Ca함량(含量)은 수량(收量), 협수(莢數) 및 건물중(乾物重)과 정상관(正相關)이 있었다. 2. 석회(石灰)는 단독효과(單獨效果)도 좋았지만 붕소(硼素)와의 병용(倂用)이 더 효과적(效果的)이었으며 가장 효과적(效果的)인 처리(處理)는 $Ca+B+K_1$구(區)였다. 3. 식물생육(植物生育)과 식물체중(植物體中) Ca/B율(率)은 어떠한 경향(傾向)을 보이지 않았다. 4. 붕소시용(硼素施用)은 석회처리구(石灰處理區)는 물론 무석회구(無石灰區)에서도 Ca흡수(吸收)를 증가(增加)시켰다. 5. 붕소(硼素)는 대두(大豆)의 협수(莢數), 100입중(粒重)을 증가(增加)시켰고 대두엽중(大豆葉中) 붕소함량(硼素含量)은 협수(莢數)와 정상관(正相關)을 보였다. 6. 석회(石灰), 가리(加里), 붕소(硼素)의 1회기비(回基肥)는 상치와 후작대두(後作大豆)에까지 효과(效果)가 나타났다.

• 농업과학연구
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• 제3권2호
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• pp.139-144
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• 1976

신개간지토양(新開墾地土攘)의 합리적(合理的)인 지력증진(地力增進) 개선방안(改善方案)을 구명(究明)하기 위(爲)하여 7종(種)의 토양개량방법(土壤改良方法)을 처리(處理)하고 대두(大豆)을 재배(栽培)하였던바 그결과를 요약(要約)하면 다음과 같다. 신개간지(新開墾地) 토양(土攘)에서는 pH가 낮고 유기물(有機物)과 인산(燐酸)은 물론 석회(石灰) 마그네슘등(等)의 염기가 부족(不足)하였다. 석회(石灰)와 용성인비(熔成燐肥)는 토양산도(土壤酸度)의 교정효과(校訂效果)가 컷으며 유기물(有機物)의 증가(增加)에 대해서는 퇴비(堆肥)의 효과(效果)가 가장 큰 것과 퇴비(堆肥)와 용성인비(熔成燐肥)는 토양중(土壤中)의 칼슘함량(含量)을 증가(增加)시키는 효과(效果)가 컷으며 석회(石灰) 용성인비(熔成燐肥) 퇴비(堆肥) 및 심경(深耕)모드가 토양중(土壤中)의 고토함량(苦土含量)을 현저(顯著)히 증가(增加)시켰다. 그리고 퇴비(堆肥)는 토양중(土壤中)의 가리함량(加里含量)을 증가(增加) 시키는 효과(效果)가 현저(顯著)하다. 석회용성인비(石灰熔成燐肥) 및 퇴비(堆肥)는 식물체내의 마그네슘함량(含量)의 증가(增加)에 현저(顯著)한 효과(效果)를 나타내었으며 석회(石灰) 및 용성인비(熔成燐肥)는 각각(各各) 종실중(種實重)의 증효효과(增效效果)가 컸다. 3요소(要素) 퇴비(堆肥) 및 석회시용(石灰施用)과 동시(同時)에 심경(深耕)을 실시(實施)한 구(區)에서 최고(最高)의 종실수량(種實收量)을 보였다. 종실수량(種實收量)은 토양산도(土壤酸度), 토양중(土壤中)의 유기물(有機物) 고토함량(苦土含量) 그리고 식물체내의 고토함량(苦土含量)과 현저(顯著)한 정(正)의 상관관계(相關關係)를 나타내었다.

• Journal of Nutrition and Health
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• 제38권7호
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• pp.544-552
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• 2005

This study was conducted to examine the correlation among bone mineral density (BMD), hair and nail calcium and magnesium contents, and nutrient intakes in preschool children in Chungnam district. A total of 111 preschool children (61 boys, 50 girls) measured the anthropometric characteristics, the bone mineral density of carpus using DEXA and hair and nail calcium and magnesium contents were analyzed by ICP spectrometer. The average ages of the study subjects were 55.7 months in boys and 53.0 months in girls (3.8${\~}$7 years). The birth height and weight of subjects were 51.0 cm and 3.3 kg in boys and 50.3cm and 3.2kg in girls, respectively. The average height, weight, $\%$ body fat, and obesity index were 111.6 cm, 19.6 kg, $15.0\%,\;96.1\%$ in boys and 108.6 cm, 18.5 kg, $17.5\%,\;98.1\%$ in girls, respectively. The bone mineral density in carpus was $0.25 g/cm^2$ in boys and $0.24 g/cm^2$ in girls. The hair calcium and magnesium contents were 440.9 ppm, 16.4 ppm in boys and 373.2 ppm, 28.9 ppm in girls. The nail calcium and magnesium contents were 9.4 ppm, 2.1 ppm in boys and 10.4 ppm, 2.4 ppm in girls. The intakes of energy, calcium, iron, zinc, vitamin A. niacin, and vitamin C did not meet the Korean RDAs. The ultradis and average carpus BMD were positively correlated to the plant calcium intake (p < 0.05, p < 0.05). And the ultradis, distal, and average carpus BMD were positively correlated to the plant iron intake (p < 0.05, p < 0.05, p < 0.05). The average bone mineral density in the carpus was positively correlated to the nail magnesium content (p < 0.05). Therefore, more systematic studies to investigate the roles of iron and calcium intakes, nail magnesium content in bone development of preschool children were required.

• 공업화학
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• 제7권2호
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• pp.315-320
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• 1996

본 실험에서는 보류향상제의 첨가량과 중질 탄산칼슘 첨가량에 따른 탄산칼슘 보류량(회분함량)을 조사하였으며, 동일 회분량에서 종이의 기계적 광학적 특성을 비교하였다. 각 보류시스템 모두 보류향상제 첨가량을 증가시키면 중질 탄산칼슘(입자평균직경 $3.2{\mu}m$) 보류, 즉 종이의 회분량은 증가한다. 이 경우 보류향상제와 중질 탄산칼슘 첨가량을 조절하여 이미 예정된 회분량이 함유된 종이를 초지할 수 있다. 종이의 인장지수, 파열지수, 인열지수 및 내부결합강도는 종이의 회분량이 증가됨에 따라 직선적으로 감소한다. 특히 동일 회분량에서 비교하면, 콤포질 시스템에 의한 종이에서 제반 강도가 높고, 듀알 폴리머 시스템에서는 강도가 낮다. 불투명도는 회분량 증가에 따라 함께 증가하며, 하이드로콜 시스템에서 가장 높고 역시 듀알 폴리머에서 가장 낮다. 동일 불투명도에서 종이의 강도는 콤포질, 하이드로콜, 듀알 폴리머 시스템 순으로 감소한다. 그러나 보류향상제의 우열을 판단하기 위해서는 충전제의 보류량과 종이의 강도 이외에도 적정 생산조건 및 적정 공정조건과 같은 여러 가지 다른 요인들도 고려되어야 한다.

• Asian-Australasian Journal of Animal Sciences
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• 제20권8호
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• pp.1266-1271
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• 2007

This study examined effects of calcium supplemented milk on bone loss in ovariectomized rats. Twenty four Sprague-Dawley female rats, 7 weeks-old, were divided into 4 groups, ovariectomized and fed diets containing: 1) control, no Ca supplemented milk, 2) ovx 1, Ca carbonate supplemented milk, 3) ovx 2, ionized Ca supplemented milk, and 4) ovx 3, nano Ca supplemented milk. All rats were fed 1 ml of milk containing 20 mg supplemented Ca. After 18 wk feeding, body weight gain and food efficiency ratio were significantly different between ovx 1 and ovx 3. Serum concentration of calcium and phosphorus were not different among groups. However, there was a significant difference in calcium content of dry femoral weight in ovx 3 compared with the control and ovx 2. In addition, femoral bone mineral density ($g/cm^2$) was significantly greater in ovx 3 than in other groups (p<0.05). The ovx 3 group showed the highest stiffness (N/mm), maximum energy (N) in femur and trabecular bone area (%). The present study indicated that nano Ca supplementation in milk may be an effective way to enhance bone calcium metabolism for ovariectomized rats.

• Asian-Australasian Journal of Animal Sciences
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• 제29권10호
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• pp.1477-1482
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• 2016

This study was conducted to investigate the effects of diets with varying levels of calcium on egg production, shell quality and overall calcium status in aged laying hens. A total of five hundred 70-wk-old Hy-Line Brown layers were divided five groups and fed one of the five experimental diets with 3.5%, 3.8%, 4.1%, 4.4%, or 4.7% Ca, for 10 weeks. There were no significant differences in feed intake, egg production and egg weight among groups. The cracked eggs were linearly reduced as dietary Ca levels increased to 4.7% (p<0.01). A significant linear improvement for eggshell strength and thickness were determined with increasing dietary Ca levels (p<0.01). The contents of serum Ca and phosphorus were not affected by dietary Ca levels. With increase in dietary Ca levels, the tibial breaking strength slightly increased. There were no significant differences in the tibial contents of ash, Ca and phosphorus among groups. In conclusion, eggshell quality, as measured by appearance, strength and thickness of eggshell, were influenced by dietary Ca content as expected (p<0.05). These results suggested that aged laying hens require relatively higher level of Ca than required levels from current Korean feeding standards for poultry.

• 한국식품영양과학회지
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• 제23권1호
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• pp.13-22
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• 1994

This study was designed to investigate the effects of dietary protein and caffeine consumption levels on Ca, P, Na and K metabolism. One hundred twenty rats were divided into twelve groups according to age, protein level and caffeine consumption such as group(120-130g young rat, 250-300g adult rat) , dietary protein group (20% normal protein , 85 low protein) , caffeine consumption group(0, 3.5mg, 7.0mg). Low protein diet containing high caffeine levels caffeine levels increased calcium, phosphorus, sodium and potassium contents of urine and fecal in rats. Young rat has higher level of calcium, phosphorus , sodium and potassium than adult rat. In the serum, calcium contents were not affected by age, dietary protein levels and caffeine consumption . However, phosphorus, sodium and potassium contents of serum in adult rat were higher than young rat. In the liver, potassium decreased with decreasing dietary protein levels. In the kidney, calcium , phosphorus and potassium contents were not different by age group, dietary protein levels and caffeine consumption , but sodium content was significantly reduced in the adult rat.