• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.247-248
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• 2010

This study is of manufacturing artificial lightweight aggregates using industrial wastes. The ingredients for manufacturing lightweight aggregate were stone sludge and bottom ash for main materials, and steel slag(SS), glass abrasive sludge(GS) and blast furnace slag(BS) respectively for accessory material. Their precursors were sintered in the range of $1,050{\sim}1,150^{\circ}C$ for 5 min. The sintered results show that the lightweight aggregate with SS had low water absorption ratio and density at $1,150^{\circ}C$. There's a possibility that if GS is used more than the range of this study, GS can be manufactured lightweight aggregate. But it is judged that BS are incongruent to be used for a raw material of lightweight aggregate.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.4
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• pp.459-464
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• 2008

This study was performed to investigate the effect of calcium-rich large anchovy on calcium metabolism in rats for 5 weeks. Experimental animals were randomly assigned to 5 treatments with 14 heads of Spraque Dawley male rats in each group. The experimental diets were as follows; market milk group (M) as control, market milk+calcium-rich large anchovy group (MA), market milk＋calcium carbonate group (MC), market milk+calcium lactate group (ML), and enriched-calcium market milk group (M2), which were formulated with commercially semi-purified rat chow (AIN-diet) to maintain the same level of calcium (1%) in all groups. Femur lengths of M and M2 groups were significantly higher than other groups. Bone mineral density (BMD) and bone mineral content (BMC) and calcium content of femur were the highest in MA group than other groups. In vitro and in vivo calcium absorption rates were high in MA group (7.30% vs 27.50%) compared with those of the other groups. Serum total-cholesterol and HDL-cholesterol levels were significantly different between M group and MA group (p<0.05). Creatinine levels were significantly higher in M, MA and MC groups than in M2 group (p<0.05). Serum calcium, osteocalcin and ALPase activities were higher in calcium-rich large anchovy (MA) group among the treatments, but there was no significant difference. SGOT activity was significantly lower in M2 group than those of M, MA and MC groups (p<0.05). These results may indicate that the calcium-rich large anchovy has enforced the BMD, BMC and calcium absorption rates of in vitro and in vivo compared with the other groups and might be a calcium-enriched food with large anchovy.

• Journal of the Korea Institute of Building Construction
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• v.14 no.1
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• pp.94-101
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• 2014

Approximately 240,000 tons of waste shells are produced annually in the south and west coast of South Korea. Some of these waste shells (oyster, cockle) are recycled as seeding collector and fertilizer, but most are dumped illegally near the coast. One of the alternative solutions that can economically utilize a large amount of these waste shells is to apply them to the production of construction materials. In this research, the basic physical properties of waste shells such as oyster, cockle, clam, manila clam were investigated, and were used to prepare cement mortar with a 25% replacement ratio of sand. According to the results, the 28 day compressive strength of cement mortar with cockle and manila clam shells was similar to that of plain cement mortar. The compressive strength decreased by about 18% when clam was used. However, the cement mortar with oyster shell showed about a 35% reduction in 28-day compressive strength, and two times the absorption capacity of plain cement mortar. The reduction in compressive strength and the increase in absorption capacity were mostly associated with the porous nature of the oyster shell.

• Journal of the Korean GEO-environmental Society
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• v.15 no.8
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• pp.31-37
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• 2014

In this study, mechanical properties of Very-Rapid Hardening Polymer (VRHP) mortar were investigated. To do it, 75 VRHP mortar specimens were tested by the compressive test, bending test, bonding test, freezing and thawing test, length variation test, and water absorption test. From the test results, it was confirmed that the bond strength of VRHP was higher than that of normal concrete by 50 %, and the resistance of freezing and thawing of VRHP was more excellent than normal concrete. In addition, length variation ratio and water absorption ratio of VRHP were smaller than those of normal concrete by 20 %. Therefore, It should be mentioned that VRHP can be successfully used as the material for repairing the crack of concrete structure.

• Journal of Radiation Protection and Research
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• v.16 no.1
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• pp.33-42
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• 1991

A pot experiment on the Sr-90 uptake by the barley from a loamy-sandy soil of pH 6.05 treated with Sr-90 and slaked lime was carried out in a green house. The rate of Sr-90 uptake at maturity was, on an average, 0.41% for a naked barley Neolssalbori and 0.23% for a covered one Olbori. Transfer coefficients of Sr-90 for the former were higher than those for the latter by about 30-60% depending on the plant parts. There were, on the whole, not significant differences in the rate and in the coefficient among Sr-90 concentration treatments. Slaked lime addition equivalent to about 94kg/10a was not effective for lessening Sr-90 uptake or diminishing Sr-90 transfer coefficient. As transfer coefficients, 1.51, 4.45, 0.35, and 1.30, on the dry weight basis, could be proposed for the stem, leaf, seed, and whole top of the barley, respectively. Growth inhibition or yield decrease due to Sr-90 uptake was not observed.

• Applied Chemistry for Engineering
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• v.9 no.1
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• pp.58-65
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• 1998

Substituted dicyandiamide(Sub-DICY), Accelerated dicyandiamide(Acc-DICY), Trimellitic anhydride(TMA), Pyromellitic dianhydride(PMDA) and Phenolic curing agent(Ph.C.A.) are mainly used for epoxy powder coating curing agent. Various characteristics of epoxy films fully cured by optimum condition such as mechanical properties like $T_g$, tensile strength, elongation at break hardness, abrasion resistance and chemical properties like water absorption, acid resistance, alkali resistance and electrical properties, corrosion resistance are determined by various measuring devices and analyses devices. In conclusion, phenolic curing agent was shown excellent thoughness but severe color change as temperature increased. Acid anhydride has excellent insulation properties and color stability at elevated temperature but lower thoughness and adhesion to substrate. DICY curing agent was shown high water absorption and severe color chance as temperature increased.

• Korean Journal of Food Science and Technology
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• v.3 no.1
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• pp.52-56
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• 1971

The cooked surf clam meat was treated with BHA or EDTA, and then dehydrated by means of hot-air dehydration or sun drying. The dehydrated products were packed in glass bottle and stored for three months in the dark place. After three month storage, the pigment loss and water absorbing capacity of dehydrated products were compared with those of directly after dehydration. Both of the sun dried and hot-air dehydrated surf clam products showed a great deal of pigment loss during storage. The BHA treatment prior to dehydration of surf clam meat had good effects on the pigment retention, and the EDTA treatment had a weak effect on it during storage. The rate of rehydration of dehydrated surf clam products had markedly decreased during storage. And it could be seen that there was little difference among the rate of rehydration of the BHA or EDTA treated product and untreated one during storage.

• Journal of the Korean Wood Science and Technology
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• v.33 no.3 s.131
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• pp.64-71
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• 2005

In this study, we attempted to apply ultrasonic treatment for the preservative treatment of two softwood species, Korean pine and Japanese red pines to evaluate its effectiveness. Wood samples were submerged in oilborne preservative, copper naphthenate (NCU) and waterborne preservative, alkyl ammonium compound (AAC) and then treated with ultrasonic wave of 40 kHz, 400 W. After the treatment, the retention and penetration depth of these preservatives in the specimens were measured as a function of treatment time. Both the retention and penetration depth were continuously increased with increasing the treatment time up to 120 hours, where the retention reached about 95% by the application of AAC and the penetrating depth of 95% and 83% by the application of NCU, respectively for both species. The results of electronic microscopic observation showed that the improved retention capacity could be attributed to air deflation, wood extractive deflation working of ultrasonic wavelength, and destruction of wood pits which served as the pathway of preservatives. The results suggested that the use of ultrasonic treatment could be applied to thick wood veneers for the production of laminated wood products.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.4
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• pp.95-104
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• 2004

A styrene solution of waste expanded polystyrene with a crosslinking agent and an initiator was used as a binder for waste wood-plastic composite panels. The waste wood-plastic composite panels are prepared with various binder contents and filler-binder ratios by using a hot press molding method. The apparent density of the composite panels is increased with increasing binder content and filler-binder ratio, while their water absorption and expansion in thickness are decreased with increasing binder content and filler-binder ratio. The maximum flexural strength and wet flexural strength of the composite panels are obtained at a binder content of 35% and a filler-binder ratio of 0.8. Decreases in the flexural strengths of the composite panels due to water immersion at 20 and $100^{\circ}C$ are hardly recognized at binder contents of 30% or more.

• Journal of the Korea Organic Resources Recycling Association
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• v.12 no.4
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• pp.85-94
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• 2004

Waste wood-plastic composite panels are made on different hot press molding conditions, and tested for apparent density, water absorption, expansion in thickness and flexural strength. From the test results, regardless of molding temperature and molding time, the apparent density of the composite panels is increased with an increase in the molding pressure, while their water absorption is decreased with an increase in the molding pressure. The flexural strength of the composite panels is markedly increased with increasing molding pressure, molding temperature and molding time, and tends to become nearly constant at a molding temperature of $120^{\circ}C$ and a molding time of 15min.