• Title/Summary/Keyword: alkali-free

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A Study on Properties of High Blaine Cement for Shotcrete (숏크리트용 고분말도 시멘트의 특성)

  • Kim, Jae-Young;Kim, Teuk-Jun;Lee, Min-Suk;Ryoo, Dong-Woo
    • Journal of the Korea Concrete Institute
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    • v.22 no.5
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    • pp.633-640
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    • 2010
  • This study was performed to get basic information about properties of high blaine cement for shotcrete use. Particle size distribution, setting time and compressive strength test, analysis like as SEM, DSC thermal analysis, XRD was carried out to investigate principle properties of high blaine cement. Setting time of high blaine cement was shorter and compressive strength was higher than those of ordinary portland cement (OPC). Results of analysis showed early hydration products of high blaine cement is smaller and spread widely due to increased specific surface. From the SEM observation and analysis of DSC and XRD results, it was seen that the aluminates accelerators promoted calcium aluminium hydrates while the alkali free accelerators increased ettringite and monosulfates formation. Strength and setting time measurement of cement paste with aluminate accelerator is more effective than the alkali free accelerator in reducing the setting time and increasing early strength while alkali free accelerator is more effective in increasing the strength after 7 days.

A Study on Field Test of High-Strength Shotcrete using High-quality Additions and Accelerators (고품질 혼화재와 급결제를 적용한 고강도 숏크리트의 현장실험 연구)

  • Ma, Sang-Joon;Kim, Dong-Min
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.26 no.2C
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    • pp.121-131
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    • 2006
  • The strength standard of shotcrete in Korea is relatively lower than that in Europe where high-strength shotcrete has been developed and actively applied to the common practice, so it is hard to test a quality of high-strength shotcrete. In this study, field test was performed to find a solution improving the strength and a long-term durability on domestic shotcrete. In field test, a high-strength shotcrete was produced using high-quality additions and accelerators, and an effect of additions and accelerators was observed. In addition, quality test based on EFNARC was also performed. As a result of field test, a promotion ratio of early strength is 90~97% in case of using alkali-free accelerators, therefore, alkali-free accelerators had an effect on an increase of early strength on shotcrete. A compressive strength of shotcrete using Micro-silica fume was 45.2~55.8MPa and flexible strength was 5.01~6.66MPa, so a promotion ratio of strength was 37~79%, 17~61% respectively. It was showed that increment effect of strength by the silica fume replacement of 7.5~10% for cement mass was remarkable. As a result of test, it was possible to apply high-strength shotcrete to the domestic practice using high-quality additions such as Micro-silica fume and accelerators such as alkali-free.

Growth Performance, Humoral Immune Response and Carcass Characteristics of Broiler Chickens Fed Alkali Processed Karanj Cake Incorporated Diet Supplemented with Methionine

  • Panda, K.;Sastry, V.R.B.;Mandal, A.B.
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.5
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    • pp.677-681
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    • 2005
  • A study was conducted to see the effect of dietary incorporation of alkali (1.5% NaOH, w/w) processed solvent extracted karanj cake (SKC) supplemented with methionine on growth performance, humoral immune response and carcass characteristics of broiler chickens from 0 to 8 weeks of age. One hundred and twenty, day- old broiler chicks were wing banded, vaccinated against Marek' disease and distributed in a completely randomized design (CRD) into 3 groups of 40 chicks each, which was further replicated to 4 and fed on diet containing soybean meal and those of test groups were fed diets containing alkali (1.5% NaOH) treated SKC partially replacing soybean meal nitrogen of reference diet (12.5%) without or with supplementation of methionine (0.2%). Individual body weight of chicks and replicate-wise feed intakes were recorded at weekly intervals throughout the experimental period. Feed consumption from 1 to 14, 28, 42 and 56 d of age was recorded for each replicate and feed conversion efficiency (weight gain/feed intake) for the respective period was calculated. Mortality was monitored on daily basis. On 28$^{th}$ day of experimental feeding, two birds of each replicate in each dietary group (8 birds/diet) were inoculated with 0.1 ml of a 1.0% suspension of sheep red blood cells (SRBC) and the antibody titre (log 2) was measured after 5 days by the microtitre haemmagglutination procedure. After 42 days of experimental feeding, a retention study of 4 days (43-47 d) duration was conducted on all birds to determine the retention of various nutrients such as DM, N, Ca, P and GE. On 43$^{rd}$ day of experimental feeding, one representative bird from each replicate of a dietary treatment (4/dietary group) was sacrificed, after fasting for two hours with free access to water, through cervical dislocation to observe the weight of dressed carcass, primal cuts (breast, thigh, drumstick, back, neck and wing), giblet (liver, heart and gizzard), abdominal fat and digestive organs. The body weight gain of chicks fed reference diet and those fed diet incorporated with NaOH treated SKC (12.5% replacement) with or without methionine supplementation was comparable during 0 to 4 weeks of age. However, dietary incorporation of alkali processed SKC replacing 12.5% nitrogen moiety of soybean meal resulted in growth retardation, subsequently as evidenced by significantly (p<0.05) lowered body weight gain during 0 to 6 weeks of age in birds fed diet incorporated with alkali processed SKC at 6.43% without methionine as compared to those supplemented with methionine or reference diet. Dietary incorporation of alkali (1.5% NaOH) processed SKC replacing 12.5% of soybean meal nitrogen in the diet of broiler chickens had no adverse effect on feed conversion ratio during all the weeks of experimental feeding. The humoral immune response (HIR) as measured by the antibody titre in response to SRBC inoculation was comparable among all the dietary groups. No significant difference in the intake and retention of DM, N, Ca, P or GE was noted among the chicks fed reference and alkali processed SKC incorporated diets with or without methionine supplementation. None of the carcass traits varied significantly due to dietary variations, except the percent weight of liver and giblet. The percent liver weight was significantly (p<0.05) higher in the birds fed diet incorporated with alkali processed SKC as compared to that in other two groups. Thus solvent extracted karanj cake could be incorporated after alkali (1.5% NaOH, w/w) processing at an enhanced level of 6.43%, replacing 12.5% of soybean meal nitrogen, in the broiler diets up to 4 weeks of age, beyond which the observed growth depression on this diet could be alleviated by 0.2% methionine supplementation.

The Conversion of Jatropha Oil into Biodiesel Using Acid / Alkali Catalysts (산 / 알칼리 촉매를 사용한 자트로파유의 바이오디젤화)

  • Hyun, Young-Jin;Kim, Hae-Sung
    • Journal of the Korean Applied Science and Technology
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    • v.25 no.3
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    • pp.275-281
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    • 2008
  • The esterification of free fatty acid in Jatropha oil added by propylene glycol using p-TSA catalyst was done, and then the transesterification of Jatropha oil added by 1.0vol% GMS as an emulsifier using TMAH, and mixed catalyst(60wt%-TMAH+ 40wt%-KOH) respectively was followed at $60^{\circ}C$. The esterification conversion at the 1:8 molar ratio of free fatty acid to methanol using 8.0wt% p-TSA was 94.7% within 60min. The overall conversion at the 1:8 molar ratio of Jatropha oil to methanol and $60^{\circ}C$ using mixed catalyst was 95.4%. The kinematic viscosity of Biodiesel using TMAH and mixed catalyst in 24h met the ASTM D-6751 above $30^{\circ}C$, and showed a little more than its criterion.

Evaluation of the Ripening Degree and Functional Properties on Enzyme Modified cheese (Enzyme Modified Cheese의 숙성도 및 기능성 평가)

  • Seo, Hyeong-Ju;Hong, Jae-Hun;Son, Jong-Yeon
    • The Korean Journal of Food And Nutrition
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    • v.9 no.2
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    • pp.143-150
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    • 1996
  • The studies was carried out to investigate ripening degree and functional properties of EMC produced with pancreatic protease and palatase ML. During production of EMC, the amounts of free amino acid and free fatty acid were increased with increasing the reaction time. The amount of total nitrogen(T-N) and water soluble nitrogen(WSN) were increased with increasing time. EMC had contents of 1.79eA T-N and 0.52o WSN at 60 min of hydrolysis time. SRI and FRI value had also a similar correlationship. On the gel filtration, 2 kinds of soluble proteining capacity was also shown in alkali solution. Furthermore the foaming stability had the same result as that of the solubility. The water absorption of EMC showed the highest level at pH 4.0 and 5.0.

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Durability Characteristics of High Performance Shotcrete for Permanent Support of Large Size Underground Space (대형 지하공간의 영구지보재로서 고성능 숏크리트의 내구 특성)

  • Won, Jong-Pil;Kim, Hwang-Hee;Jang, Chang-Il;Lee, Sang-Woo
    • Journal of the Korea Concrete Institute
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    • v.19 no.6
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    • pp.701-706
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    • 2007
  • This study evaluated the durability of high-performance shotcrete mixed in the proper proportions using alkali-free and cement mineral accelerators as a permanent support that maintains its strength for the long term. Durability tests were performed the chloride permeability, repeated freezing and thawing, accelerated carbonation, and the effects of salt environments. Test results showed that all the shotcrete mixes included silica fume had low permeability. In addition, after 300 freeze/thaw cycles, the shotcrete mix had excellent freeze/thaw resistance more than the 85% relative dynamic modulus of elasticity. The accelerated carbonation test results were no effect of accelerator type but, the depth of carbonation was greater in the shotcrete mix containing silica fume. No damage was seen in a salt environments. Therefore, the high performance shotcrete mix proportions used in this study showed excellent durability.

Changes in Amounts of Polysaccharides and Polyphosphates under Catabolic Repression and Derepression in Yeast (V) (Catabolic Repression 및 Derepression에 의한 효모 세포의 다당류 함량 변화와 무기 폴리 인산(제 5 보))

  • Lee, Ki-Sung;Choi, Yong-Keel
    • The Korean Journal of Mycology
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    • v.13 no.4
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    • pp.235-241
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    • 1985
  • The present study was designed to investigate biosynthetic patterns of polysaccharides under catabolic repression and derepression in Saccharomyces uvarum. Correlation coefficients between polysaccharide synthesis and polyphosphate accumulation were examined, according to the culture phase and under various phosphate concentrations (free, limited, sufficient). During catabolic derepression, biosynthesis of glycogen was enhanced. rapidly and highly in the cells grown on minimal medium, compared with those grown on the complete medium. Acid soluble glycogen type was the main component of total glycogen and alkali soluble glycogen was synthesized in small amount, after 24 hr culture, at the time of almost exhaustion of sugar in the medium. Total glycogen was accumulated highly in proportion to the amount of phosphate added to the medium. It could be postulated that type 'C' isoenzyme among ALPase was directly or indirectly correlated with the glucan synthesis. Mannan synthesis indicated maximal amount at the early exponential phase and stationary phase, and also acid soluble sugars at the stationary phase. Correlation coefficient between the mannan synthesis and poly-p-'C' accumulation, and also between mannan synthesis and phospholipid content indicated 0.866 and 0.726, respectively.

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Treatment Characteristics of Plating Wastewater Containing Freecyanide, Cyanide Complexes and Heavy Metals (I) (도금폐수내 유리시안과 착염시안 및 중금속의 처리특성 (I))

  • Jung, Yeon-Hoon;Lee, Soo-Koo
    • Journal of Korean Society on Water Environment
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    • v.25 no.6
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    • pp.979-983
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    • 2009
  • The mean pH of wastewater discharged from the plating process is 2, so a less amount of alkali is required to raise pH 2 to 5. In addition, if sodium sulfite is used to raise pH 5 to 9 in the secondary treatment, caustic soda or slaked lime is not necessary or only a small amount is necessary because sodium sulfite is alkali. Thus, it is considered desirable to use only $FeSO_4{\cdot}7H_2O$ in the primary treatment. At that time, the free cyanide removal rate was highest as around 99.3%, and among heavy metals, Ni showed the highest removal rate as around 92%, but zinc and chrome showed a low removal rate. In addition, the optimal amount of $FeSO_4{\cdot}7H_2O$ was 0.3g/L, at which the cyanide removal rate was highest. Besides, the free cyanide removal rate was highest when pH value was 5. Of cyanide removed in the primary treatment, the largest part was removed through the precipitation of ferric ferrocyanide: $[Fe_4(Fe(CN)_6]_3$, and the rest was precipitated and removed through the production of $Cu_2[Fe(CN)_6]$, $Ni_2[Fe(CN)_6]$, CuCN, etc. Furthermore, it appeared more effective in removing residual cyanide in wastewater to mix $Na_2SO_3$ and $Na_2S_2O_5$ at an optimal ratio and put the mixture than to put them separately, and the optimal weight ratio of $Na_2SO_3$ to $Na_2S_2O_5$ was 1:2, at which the oxidative decomposition of residual cyanide was the most active. However, further research is required on the simultaneous removal of heavy metals such as chrome and zinc.

Cytotoxic Effects and Components of Lipid Fractions from Soybean Products on Cancer Cell Lines (대두식품 지질추출물의 세포독성 및 지질성분분석)

  • 송성광;김광혁;김희숙
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.30 no.6
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    • pp.1266-1271
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    • 2001
  • The cytotoxic effects of lipid extracts from soybean products were studied using K562 human leukemia cell, Yac1 mouse leukemia cell and S 180 mouse sarcoma cell. Total lipids from soybean powder, soybean curd residue and doenjang were extracted with chloroform/methanol (2 : 1) and water saturated butanol, consecutively, and fractionated into acetone supernatants (AS fraction) and acetone precipitates (AP fraction) by adding excess acetone. AS fraction of doenjang lipids showed the strongest cytotoxic effects on K562, Yac1 and S180 cancer cells, whereas each lipid fraction of soybean curd residue also showed relatively weak cytotoxic effects on cancer cells but soybean powder did not. AS and AP fractions of doenjang contained more free fatty acids than those of soybean curd residue and soybean. And when lipid fractions were digested with 0.4 N KOH/methanol, doenjang lipid fractions showed to contain some alkali-stable substances which showed positive reaction with ninhydrin solution on silica TLC separation.

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Properties of Non-Sintered Cement Pastes Immersed in Sea Waters at Different Temperatures for Binders Mixed with Different Ratios (침지된 해수 온도 및 결합재 혼합비에 따른 비소성 시멘트의 강도 특성)

  • Jun, Yubin;Kim, Tae-Wan
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.20 no.5
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    • pp.75-84
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    • 2016
  • This paper presents an investigation of the mechanical properties on non-sintered cement pastes immersed in sea waters at three different temperatures. The non-sintered cement pastes were synthesized using blended binder(Class F fly ash; FA and ground granulated blast furnace slag; GGBFS) and alkali activator(sodium hydroxide and sodium silicate). Binders were prepared by mixing the FA and GGBFS in different blend weight ratios of 6:4, 7:3 and 8:2. The alkali activators were used 5wt% of blended binder, respectively. Calcium carbonate was used as an chemical additive. The compressive strength, bulk density and absorption of alkali-activated FA-GGBFS blends pastes were measured at 3 and 28 days after immersed in sea waters at three different temperatures($5^{\circ}C$, $15^{\circ}C$ and $25^{\circ}C$). The XRD and SEM tests of the pastes were conducted at 28 days. Water-soluble chloride(free chloride) and acid-soluble chloride(total chloride) contents in the pastes were also measured after 28 days immersion in sea water. The experimental results showed that increasing the content of FA in alkali-activated FA-GGBFS blends pastes immersed in sea water increases the absorption, water-soluble chloride content and acid-soluble chloride content, and reduces the compressive strength and bulk density. And it was found that there was a variation of strength change for the alkali-activated FA-GGBFS blends pastes immersed in sea waters at three different temperatures that depends on the blending ratio of FA and GGBFS.