• Proceedings of the Korea Concrete Institute Conference
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• 1993.10a
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• pp.108-112
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• 1993

The term Alkali-Silica Reaction (ASR) is used to describe a reaction between certain siliceous aggregates and hydroxyl ions present in the pore fluid of a concrete. The ASR is affected by the content of alkali, the particle size and the content of reactive aggregate, water-cement ratio, humidity, temperature and so on. In this paper, the fluence of alkali content and kind of added alkali to the ASR was studied. As a result, the more the content of alkali was increased, the more the mortar-bar was expand and the expansion of mortar-bar was showed differently with the added alkali kinds, The reaction products by ASR were observed by SEM(Scanning Electron Microscope) and analyzed by EDXA(Energy Dispersive X-ray Analysis) also and showed a gel composed of alkali(Na+, K+), silica and calcium.

• Magazine of the Korea Concrete Institute
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• v.6 no.2
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• pp.108-117
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• 1994

This study was performed to investigate the Alkali-Silica Reaction(ASR) of crushed stones using chemical analysis, polarization microscope, XRD, chemical method(KS F 2545, ASTM C 289), mortar-bar method( KS F 2546, ASTM C 227) and Scanning Electron Microscope (SEM ) and Energy Dispersive X-ray Analysis(EDXA) of reaction products by ASK in the mortar bars and to investigate the influence on alkali content and kind of added alkali to the ASR. Test results show that one kind of domestic crushed stone is estimated as deleterious by ASTM chemical method and mortar bar method, and reaction product is proved as alkali silicate gel by EDXA.

• Journal of Plant Biology
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• v.13 no.1
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• pp.13-24
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• 1970

This investigation was one of the series of ecological studies on the plant communities of Quelpart Island which was held in 1969. It was aimed at studying the ground vegetation of Torreya nucifera and the soil properties of the ground in which it grows. Observaton of the flora in a place where wild growth of Crinum maritimum, soil properties and distribution of micro-organisms in a place where wild growth occurs, were also made. 1) A few kinds which have important values among the ground vegetation fo Torreya nucifera forest are Liniope graminifolia, Convallaria keiskei, Sasaquelpaertensis, Carex kingiana, Pteridium aquilinum, Pyrola japonica, Hedera tobleri, etc. 2) While the studies of 25 Quadrats were being held, 29 species in A plot, 30 species in B plot, and 26 species in C plot have been found. 3) The kind which has the highest important value among the species located in naked plot(outside of Torreya nucifera forest) is Zoysia japonica and 18 other kinds were found. 4) The soil fertility through all depths are found higher in the forest soil than in that of open places. 5) P2O5, K, and total exchangeable bases etc. have shown the difference of contents according to the depth and generally had lower value as much as it goes down. 6) The content of N was a lot higher than any other forest soil and P2O5, K and total exchangeable bases seemed to be a little lower. 7) The overall flora of Todo consists of 71 species (9 species of wood plant and 62 species of herbs) added 28 kinds of non-reported species. 8) Themineral contents are the highest at a place of wind growth of Crinum maritimum which has much organic matter. The subsoil of this place is more fertile than surface soil. 9) The soil of Todo which is sandy soil, consists of shellfish shell and quartz, and has low fertility and alkali. 10) In the total occurrences of micro-organisms, bacteria was the greatest in number followed by actinomycete and fungi, in that order. 11) A survey of the soil depth and the ecological distributional pattern of micro-organismsm revealed that the number of micro-organisms is the greatest on the surface, gradually decreasing in proportion to the depth. 12) It was found that a comparatively greater number of micro-organisms occurred when the soil showed an adequate increase in water content.

• Applied Biological Chemistry
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• v.9
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• pp.71-81
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• 1968

Defatted rice bran is mixed with diluted acid solution, the mixture is agitated some hrs. at constant temparature. After the mixture is filtered, thus filtrate is obtained. This filtrate is phytin extract solution. (Test-1) The alkali is added to this filtrate and filtered out, then the precipitation of phytin is obtained. (Test-2) At the test-1, the effect of kind of acid, conc. of acid, amount of extract sol'n., time of extraction, temp. of extraction, to the extract amount of phytin is tested. Consequently, the following facts are known. 1. Amount of phytin extract is greater HCI extraction than $H_{2}SO_4$ extraction. 2. At 0.3% HCI, the amount of phytin extract is greatest of all HCl extraction. 3. The sufficient amount of acid solution is 8-10 times of amount of defatted rice bran. 4. The time of extraction at room temperature is sufficient 8-12 hrs. 5. When extract temperature is $20-30^{\circ}C$, the amount of phytin extraction is greater of all temp. 6, When defatted rice bran 20 g is shanken with 160 ml of 0.3% HCl for 10 hr. at room temp., in this case the amount of phytin extract is 11.34% of defatted rice bran, it is 93% of theoretical yield. At the test-2 the effect of kind of precipitation agent, degree of nutralization to the amount of phytin prcipitation is tested. 1. Degree of nut. is best at pH 6.8-7.0. 2. When use of $Ca(OH)_2$ the amount of phytin precipitation is more than use of KOH, NaOH, or $NH_{4}OH$. 3. At pH 6.0-7.2, the solubility of phytin is followed. K-phytate > $NH_{4}-phytate$ > Na-phytate > Ca-phytate 4. When phytin extract solution is nutralized with $Ca(OH)_2$ to pH 7.0, the amount of phytin precipitation is 94.78% of theoretical yield.