• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.603-610
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• 2017

Steel used for various industrial fields including ammunition is vulnerable to corrosion so surface treatments are required such as plating, painting and chemical conversion coating. Zinc phosphate, used for ammunition manufacturing, is used to stick the stable compound on the surface by chemical conversion of metal. The quality of phosphate coating depends on many factors such as total acidity and iron content. In this study, we studied the influence of total acidity and iron content on coating weight and corrosion resistance of phosphate coating. The surface structure of the coating becomes dense and corrosion resistance is improved with increasing iron content. However, total acidity influences only the thickness and phosphate coating weight. In conclusion, this study suggests the optimal range of total acidity and iron content to manufacture the ammunition.

• Korean Journal of Microbiology
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• v.6 no.1
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• pp.22-28
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• 1968

Chlorella ellipsoidea cells were cultured in an iron, copper, zinc, manganese, molybdenum or boron-free medium. Biosynthetic activities of nucleic acids, protein and phospholipid in chlorella cells, which were growing in a microelement deficient medium were compared with those of the normal cells by measuring the contents of phosphate, amino acids or UV-absorbing substances in the various cell fractions. When the algae were grown in a molybdenum-free medium, the amounts of phosphate in the acid-soluble fraction of the cells increased, whereas the amounts of alkali-stable protein and RNA decreased compared with the normal cells showing that the synthesis of protein and RNA from the early products of photosynthesis was inhibited. When the algae were grown in a boron-free medium, amounts of alkali-labile protein and phospholipid of the cells decreased, while the amount of phosphate in acid-soluble fraction increased compared with the normal cells showing that the biosynthesis of protein and phospholipid from the early products of photosynthesis was retarded. In general, amounts of protein and RNA in the microelement deficient cells significantly decreased compared with those of the normal cells. Phosphate content in the acid-soluble fraction of the algal cell grown in an zinc, copper, molybdenum, or boron-free medium increased considerably, whereas that of the algal cell grown in an iron or manganese-free medium decreased remarkably compared with that of the control. It is considered, therefore, that molybdenum, zinc, copper and boron etc. play an important role in the biosyntbesis of macromolecule from acid-soluble phosphate compounds, in contrast to the principal action of iron and manganese on the photosynthetic process itself.

• Bulletin of the Korean Chemical Society
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• v.26 no.8
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• pp.1277-1280
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• 2005

• Journal of Korean Society of Water and Wastewater
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• v.19 no.2
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• pp.228-237
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• 2005

The main purpose of this study was to investigate the red water reducing effects of phosphate based inhibitor when it was applied to water distribution system. The effects of pH, alkalinity, calcium concentration in the reduction of the red water also studied. The most finished water in Korea showed relatively high corrosiveness and was required to introduce some types of corrosion reducing methods such as addition of alkalinity. The precipitation of $CaCO_3$ by addition of $Ca(OH)_2$ formed porous film on the surface of the carbon steel pipes and was displaced easily from the surface of the pipes; on the other hand, addition of zinc phosphate (ZOP) formed reliable film on the surface and reduced iron release and color. Although the main function of ZOP was to suppress the release of Pb and Cu, it also reduced iron concentration released from water distribution pipes.

• 한국생물공학회:학술대회논문집
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• 2003.10a
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• pp.284-286
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• 2003

In order to optimize the culture medium for fumaric acid production using newly isolated fungi, we investigated the effects of various carbon sources and nitrogen sources. When rice bran as nitrogen source was used, the effects of trace elements (phosphate, magnesium, zinc, and iron) on fumaric acid production were also investigated. When initial glucose of 50 g/L and rice bran was employed, maximum fumaric acid was produced without addition of magnesium, zinc, and iron.

• Environmental Engineering Research
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• v.24 no.3
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• pp.434-442
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• 2019

The present study investigated a novel calcium hydroxide-coated dairy manure-derived biochar (Ca-BC) for adsorption of phosphate from water and dairy wastewater. The Ca-BC showed much higher adsorption of phosphate than that of dairy manure-derived biochar. The Ca-BC possessed mainly the calcium hydroxide and various functional groups resulting in high reactivity between phosphate and calcium hydroxide in the Ca-BC. The adsorption of phosphate onto Ca-BC followed pseudo-second order kinetic and Freundlich isotherm models indicating chemisorptive interaction occurred on energetically heterogeneous surface of Ca-BC. The maximum adsorption capacity of the Ca-BC was higher than those of iron oxide and zinc oxide-coated biochars, but lower than those of CaO- and MgO-coated biochars. However, the Ca-BC showed high reactivity per surface area for adsorption of phosphate indicating importance of surface functionalization of biochar. On the other hand, the adsorption of phosphate in dairy wastewater on Ca-BC was lower than that in water owing to competition between other anions in wastewater and phosphate. Overall, the Ca-BC would be a low cost and effective adsorbent for recovery of phosphate from water and wastewater.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.91.2-92
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• 2003

In order to elucidate influence of nutritional status on rice brown spot caused by Cochliobolus miyabeanus, rice cultivation soils and rice straws were collected from paddy fields where ice brown spot occurred severely, moderately, a little and none respectively. Rice plant materials were analyzed to measure inorganic nutrients in rice straws and rice seeds. Analysis of chemical properties of rice paddy soil showed that EC and contents of available phosphate, cation and silicic acid in soil with severe infections were lower than those in healthy soil. This result suggests that amount and holding capacity of nutrient contents in soils collected from paddy field with infection of C. miyabeanus are relatively low compared to those in soils collected from healthy paddy field. Analysis of inorganic nutrients in rice straws showed that amount of macronutrient elements such as silicic acids, available phosphate and total nitrogen, and micronutrients such as copper, iron and zinc in rice straws from paddy field with infection were lower than those in healthy soil. Especially amount of iron and silicic acid were very low in rice straws from paddy field soils with infection Amount of inorganic nutrients such as iron and zinc in rice seeds was the same trend as those of rice straws. These results showed that one of major factors affecting rice brown spot was amount of nutrient contents in soil and rice straw.

• Korean Journal of Community Nutrition
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• v.11 no.5
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• pp.575-586
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• 2006

This study was performed to compare nutrient intakes, diet quality and serum indices (TG, Total cholesterol, LDL-cholesterol, HDL-cholesterol, RBC, Hb, Hct, Serum iron, ferritin, MCV) of obese and normal weight children. The subjects were 149 children living in the Seoul and Gyeonggi areas. Each subject was assigned to one of such as normal weight group ($15th{\le}BMI$ percentile < 85th, n = 82) or obese children ($85th{\le}BMI$ percentile, n = 67) according to their percentile of BMI by The Korean Pediatric Society. Data on dietary intakes, body composition and serum indices were obtained. Differences of all the above variables were assessed. Energy, carbohydrate, fat, cholesterol, total fatty acid, SFA, MUFA, PUFA, phosphate, potassium, zinc, vitamin $B_1$ and vitamin $B_6$ intakes of girls in the obese group were higher than those of the normal weight group (p<0.05). The intake of fiber was as insufficient as below 50% of KDRIs in both groups. Nutrient adequacy ratio of calcium, iron, phosphate, zinc and folate in obese boys were lower than those of normal weight boys (p<0.05). Energy intakes of grain and milk and dairy food in the obese girl group ($905.9{\pm}344.5kcal,\;210.9{\pm}166.4kcal$) were higher than those of normal weight girls ($671.2{\pm}360.7kcal,\;184.0{\pm}103.5kcal$) (p<0.05). HDL-cholesterol level of obese boys ($52.7{\pm}6.3mg/dL$) was significantly lower than that of normal weight boys ($65.3{\pm}15.6mg/dL$). Serum iron level of obese boys and girls (boys: $79.4{\pm}32.6mg/dL$, girls: $98.3{\pm}16.2mg/dL$) was significantly lower than those of normal weight children (boys: $104.8{\pm}38.6mg/dL$, girls: $106.7{\pm}28.9mg/dL$) (p<0.05). These results suggest that there should be sensible food selection and more intakes of fruit and vegetable are needed to improve the nutritional status in obese children.

• Corrosion Science and Technology
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• v.4 no.1
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• pp.15-18
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• 2005

Hydroxyapatite(HAp) was synthesized using the waste sludge from semiconductor process and used as an anticorrosive pigment. The water absorption of coating pigmented with anticorrosive pigment and the corrosion at interface between coating and substrate were monitored using AC impedance techniques. The anticorrosive performance of HAp was compared with those of red lead(RL) and zinc potassium chromate(ZPC), which have been known as representative anticorrosive pigments. The amount of absorbed water in ZPC- and HAp- pigmented coatings was much higher compared to that in RL-pigmented and unpigmented film. However, it seems that the water absorbed into HAp- or ZPC-pigmented film is beneficial to anticorrosive function. The anticorrosive performance of HAp is superior or at least comparable to those of ZPC and RL. The excellent anticorrosive properties of HAp can be explained by its passivating ability, caused by the reaction of the soluble component of HAp with Fe to form iron phosphate in the presence of water.

• Korean Journal of Community Nutrition
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• v.7 no.6
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• pp.824-832
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• 2002

The present study was conducted to evaluate nutritional intake by lunch-box of middle school girls who live in Chonbuk area. Anthropometric measurements and food intake from lunch-box over a three day period were investigated in a total of 110 middle school girls from rural (n＝37) and urban (n＝73) areas. The results are summarized as follows : 1. Not all the steamed rice in the lunch-box had enough mixed-cereal. 2. In the survey of food intake by food groups, 70.5% of the food came from the cereal group. 3. The intake of protein, phosphate, Vitamins $B_1 and B_2$, niacine and Vitamin E were adequate, however, the intake of other nutrients was significantly lower than those of one-third of the Korean RDA.4. Protein, lipid, and zinc intakes of the students from the rural area were significantly lower than those of students from the urban area. however, the carbohydrate and dietary fiber intakes of those in the rural area were significantly higher than those of the students in the urban area. 5. The percentage of calories from carbohydrate : protein lipid ratio was 67.6 : 12.2 : 16.9 for students in the rural area and 59.2 : 14.9 : 22.5 respectively for those in the urban area. In Summary, the intake of calcium, iron, Vitamins A, $B_6$, and D, folate and zinc from lunch-box in middle school girls was much lower than that of one-third of the Korean RDA. The intake of carbohydrate and dietary fiber of the students in the rural area was significantly higher, but that of protein, lipids, and zinc was lower than that of the students in the urban area. Therefore, nutritional education programs for both students and their parents should be provided to improve the daily food intake from lunch-box.