• Environmental Engineering Research
• /
• v.18 no.3
• /
• pp.163-168
• /
• 2013

In this study, an innovative media, iron mixed ceramic pellet (IMCP) has been developed for arsenic (As) removal from groundwater. A porous, solid-phase IMCP (2-3 mm) was manufactured by combining clay soil, rice bran, and Fe(0) powder at $600^{\circ}C$. Both the As(III) and As(V) adsorption characteristics of IMCP were studied in several batch experiments. Structural analysis of the IMCP was conducted using X-ray absorption fine structure (XAFS) analysis to understand the mechanism of As removal. The adsorption of As was found to be dependent on pH, and exhibited strong adsorption of both As(III) and As(V) at pH 5-7. The adsorption process was described to follow a pseudo-second-order reaction, and the adsorption rate of As(V) was greater than that of As(III). The adsorption data were fit well with both Freundlich and Langmuir isotherm models. The maximum adsorption capacities of As(III) and As(V) from the Langmuir isotherm were found to be 4.0 and 4.5 mg/g, respectively. Phosphorus in the water had an adverse effect on both As(III) and As(V) adsorption. Scanning electron microscopy results revealed that iron(III) oxides/hydroxides are aggregated on the surface of IMCP. XAFS analysis showed a partial oxidation of As(III) and adsorption of As(V) onto the iron oxide in the IMCP.

• Nuclear Engineering and Technology
• /
• v.38 no.7
• /
• pp.675-680
• /
• 2006

The neutron transmutation doping of silicon (NTD), as a method to produce a high quality semiconductor, utilizes the transmutation of a silicon element into phosphorus by neutron absorption in a silicon single crystal. In this paper, we present the design of a neutron screen for a 6' Si ingot irradiation in the NTD2 hole of HANARO. The goal of the design is to achieve an even flat axial distribution of the resistivity, or $Si^{30}(n,{\gamma})Si^{31}$ reaction rate, in the irradiated Si ingot. We used the MCNP4C code to simulate the neutron screen and to calculate the reaction rate distribution in the Si ingot. The fluctuations in the axial distribution were estimated to be within ${\pm}2.0%$ from the average for the final neutron screen design; thus, they satisfy the customers' requirement for uniform irradiation. On the other hand, we determined the optimal insertion depths of the Si ingots by varying the critical control rod position, which greatly affects the axial flux distribution.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.44 no.1
• /
• pp.25-30
• /
• 2011

We investigated the effect of a lactic acid extract of Sargassum horneri (ExSL) as a calcium supplement on bone formation in 48 female Sprague-Dawley rats for 4 weeks of their growth phase. The rats were divided into four groups based on diet: two calcium-sufficient and two calcium-deficient diets. The normal control group (NC) was fed AIN-93G; the NCS group was fed the same diet containing 1% extract; the calcium-deficient control (DC) diet was based on AIN-93G; and the DCS group received the same calcium-deficient diet plus 1% extract. Bone formation in the rats was evaluated using the wet weight, length, diameter, and bone mineral density (BMD) of the femur. Serum parameters were also examined. The food intake among the groups did not differ significantly (P<0.05). The NCS group gained the most body weight, while the DC group gained much less weight than the other groups. The feeding efficiencies of the groups that received the extract (NCS and DCS) were slightly higher than those of the control groups (NC and DC). The calcium intakes of all groups depended on the amount of calcium in the feed; the NCS and DCS diets contained 12.15 mg more calcium than the NC and DC diets. The calcium absorption was lower in NCS than in DC and DCS, but significantly higher than in NC (P<0.05). The BMDs in the calcium-sufficient groups were not significantly different (P<0.05), while in the calcium-deficient groups the BMD was significantly higher in DCS than in DC (P<0.05). The serum calcium and phosphorus levels in all groups were not associated with markers of bone growth related to the extract. The osteocalcin content and alkaline phosphatase (ALPase) activity were higher in the calcium-deficient groups than in the normal groups (P<0.05). Ultimately, the osteocalcin content and ALPase activity were lower in DCS compared to DC. These results suggest that the addition of ExSL promotes bone formation and calcium absorption in growing rats.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.41 no.4
• /
• pp.405-410
• /
• 1996

To elucidate the pattern of nutrient absorption and endosperm consumption as the seedling age of rice, Dongjinbyeo was raised in the seedling box with different nitrogen levels. Absorption of nitrogen and phosphorus were high in the order of artificial seed bed soil, sand with N-1g /box and sand without N from 3 and 5 days after seeding but, potassium wasn't significantly different between sand＋N-1g /box and sand. Endosperm consumption rate was high in the order of artificial seed bed soil, sand ＋ N-1g /box and sand but, endosperm dependence rate (endosperm consumption /top dry weight) was vice versa. Seedling height and dry weight were higher in the order of artificial seed bed soil, sand+N-1g /box and sand from 3 days after seeding, number of leaves were more from 5 days after seeding in same order.

• Korean Journal of Poultry Science
• /
• v.34 no.3
• /
• pp.207-215
• /
• 2007

This work was carried out to assess the effect of microbial phytase (MP) on the performance, retention and excretion of phosphorus, and nutrients availability in broiler chicks. Two hundred and sixteen one day old Ross strains broiler chicks were used to investigate on performance for 5 weeks (earlier $(0{\sim}2wk)$, finisher $(3{\sim}5wk)$) and were divided 3 treatments, three cages per treatment and 12 birds per cage. Treatments are P0 (basal diet), P1 (microbial phytase 300 FTU/kg), and P2 (microbial phytase 600 FTU/kg). After 5 weeks, three diets containing 0, 300, 600 FTU/kg of microbial phytase were fed to 5-wk-old broilers to assess the digestibility. Twenty seven broilers were divided into 3 treatments (9 birds per treatment) to investigate on the absorption and retention of phosphorus and nutrient digestibility. Body weight gain and feed efficiency were highly significant at P1 and P2 treatments compared to those of P0 (P<0.05), however, feed intake was no significant difference among all treatments (P>0.05). The excretion of phosphorus decreased in P1 and P2 compared to P0 (P<0.05). The digestibility of nutrients and amino acid was high in P1 and P2 treatments compared to P0 (P<0.05). Ileal digestibility was lower about $1{\sim}2%$ than feces digestibility (P>0.05). Finally, microbial phytase influenced on the performance, the retention and excretion of phosphorus and ileal and feces digestibility in broilers.

• Korean Journal of Poultry Science
• /
• v.34 no.2
• /
• pp.119-128
• /
• 2007

The effects of microbial phytase on laying performance, egg quality, and ileal digestibility of nutrients and amino acids were examined at three levels of phytase (0, 300, 600 unit/kg) in 55-wk-old White Leghorn for 4 weeks. Egg productivity tended to increase with supplemental phytase compared to that of control. Daily feed intake of hens fed phytase also increased. Egg shell thickness was not significantly different among the treatments. Haugh unit and yolk color were not statistically different. However, egg shell breaking strength was high at phytase treatment. Excretion and absorption of nitrogen were no difference among all treatments, but those of phosphorus was higher in the phytase treatment than control. The digestibility was high at crude fiber, crude ash, calcium and phosphorus in nutrients, at lysine, methionine and phenylalanine in essential amino acids, and alanine, cystine, glutamic acid, glycine and tyrosine in non-essential amino acids. In conclusion, supplemental microbial phytase in laying hens diet may help to improve egg production and to decrease P of feces. But, further studies were needed to investigate on the digestibility.

• Korean Journal of Soil Science and Fertilizer
• /
• v.26 no.3
• /
• pp.181-188
• /
• 1993

The effects of paddy-upland rotation and cropping system on the mineralization of soil organic nitrigen, on the change of organic matter and available phosphorus content in the soil, and on the rice yield and nutrients absorption were studied in Seokcheon fine-sandy loam soil. 1. In the incubation test mineralzed soil nitrogen and the nitrogen extracted by pH 7 phosphate buffer solutions were higher in the soils from every and two year rotation systems than continuous rice cultivation. In terms of cropping system potato-chiness cabbage-rice increased them more than soybean-rice system. 2. The change of soil organic matter and available phosphorus contents were not much in continuous rice cultivation, while in rotation system they decreased as the paddy-upland rotation frequency decreased. In terms of cropping system they decresed more in potato-Chinese cabbage-rice system compared with soybean-rice systems. 3. The rice yield was higher in the paddy-upland rotation system than that of continuous rice cultivation. However, the effects were decreased gradually every year, as shown by 26~20, 17~5, and 5~4% yield increase for first, second, and third year, respectively, in potato-Chinese cabbage-rice and soybean-rice system compared with continuous rice cultivation. 4. All the absorbed nutrient contents increased in every and two year rotation system compared with continuous rice cultivation. In terms of cropping system potato-Chiness cabbage-rice system increased them more compared with soybean-rice system.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.36 no.5
• /
• pp.651-656
• /
• 2007

Fish-frames which are left after obtaining fillets or muscle during fish processing, consist of useful food components such as muscle, collagen, calcium, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). This study was carried out to prepare snack using flatfish frame and also to elucidate food component characterization of the snack. The results of heavy metal and volatile basic nitrogen (VBN) content suggested that flatfish frame was a suitable material for preparing snack. The optimal addition ratio of flatfish frame to mix was 3% for preparing snack according to the results of VBN content, water activity and sensory evaluation. The major fatty acids of the snack with 3% flatfish frame (SFF) were 16:0 and 18:0 as saturates, 18:1n-9+7 as monoenes, and 18:2n-6 and 18:3n-3 as polyenes, while EPA and DHA were contained in small amount SFF. Total amino acid content (9,281.9 mg/100 g) of the SFF was higher than that of the snack without flatfish frame (7,791.3 mg/100 g) and the major amino acids were aspartic acid, glutamic acid, proline and leucine. The calcium and phosphorus contents of SFF were 492.3 mg/100 g and 270.3 mg/100 g, respectively. The Ca/P of SFA was 1.82 which is a good ratio for the absorption of calcium. The SFF was superior in total amino acid, calcium and phosphorus contents compared to the snack without flatfish frame.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.35 no.10
• /
• pp.1467-1474
• /
• 2006

Fish-frames, which are left after obtaining fillets or muscle during fish processing, consists of useful food components, such as muscle, collagen, calcium, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). This study was carried out to prepare snack using conger eel frame (SF) for human consumption and also to elucidate food component characterization of the snack. The results of volatile basic nitrogen suggested that conger eel frame was a suitable material for preparing snack. Based on the results of sensory evaluation and costs, starch syrup was an optimal sweetener for preparing snack using conger eel frame. The starch syrup-treated SF appeared safe because the moisture content and peroxide value were below the safety limits described in the guideline of Korea Food and Drug Administration (KFDA). Starch syrup-treated SF was similar in the pattern of fatty acid composition to soybean oil, whereas EPA and DHA were detected in SF. The total content of amino acid in starch syrup-treated SF was 23.9% based on 100 g of raw material. The maj or amino acids were aspartic acid, glutamic acid, glycine and alanine. The total contents of calcium and phosphorus in starch syrup-treated SF were 4.9% and 2.8%, respectively. The Ca/P of starch syrup-treated SF was 1.9, which is a good ratio for absorption of calcium. The SF made with starch syrup was superior in EPA and DHA compositions, total amino acid, calcium and phosphorus contents to commercial snack using eel frame.

• Animal Bioscience
• /
• v.35 no.12
• /
• pp.1921-1928
• /
• 2022

Objective: This research aimed to evaluate the effects of age on growth, tibia development, and intestinal calcium (Ca) and phosphorus (P) transporter gene expressions in broiler chickens. Methods: A total of 224 male Arbor Acres broilers were fed with nutrient-adequate diets and reared in eight cages (28 broilers per cage). Eight broilers (one broiler per cage) were selected and killed at 5, 10, 15, 20, 25, 30, 35, and 40 days of age, respectively. Results: Body weight continuously increased with age of broiler chickens from 5 to 40 days. The bone weight, ash weight, diameter, and length of the tibia also increased with broiler age. By contrast, the tibia ash, Ca, and P percentages quadratically changed with age (p<0.001), and the highest values of mineral contents were observed at 20, 25, and 25 days of age, respectively. The mRNA abundances of calcium-binding protein 28-kDa (CaBP-D28k), sodium-calcium exchanger 1 (NCX1), and plasma membrane ATPase 1b (PMCA1b) increased from 5 to 25 days and then decreased up to 40 days. Similar results were noted in the mRNA abundances of IIb sodium-phosphate cotransporter (NaPi-IIb), inorganic phosphate transporter 1 (PiT-1), inorganic phosphate transporter 2 (PiT-2), nuclear vitamin D receptor (nVDR), and membrane vitamin D receptor (mVDR). The mRNA abundances of Ca and P transporters and VDRs were the highest at 25 days of age. Conclusion: These data indicate that age quadratically affects intestinal Ca and P transporter gene expression and mineral absorption capacity in broiler chickens.