• 한국식품저장유통학회지
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• 제7권2호
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• pp.207-210
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• 2000

The changes of non-cellulosic neutral sugar composition of strawberry during maturation were investigated. Arabinose, xylose, galactose and glucose were the main non-cellulosic neutral sugar of cell wall and increased until ripe stage. The main non-cellulosic neutral sugar of alkali soluble hemicellulose were arabinose, xylose, mammose, galactose. The contents of non-cellulosic neutral sugar of alkali soluble hemicellulose were increased during maturation.

• 한국안전학회지
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• 제8권2호
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• pp.30-38
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• 1993

To increase fire proofing characteristics of protective coating based on soluble alkali silicate, silicate coatings were studied on thermal properties, IR spectroscopy, solubility and intumescence. Intumescence and solubility of the samples were dependent on the strength of cationic cross-links between polysilicate particles. The degree of intumescence and solubility decrease K-silicate > Na-silicate > Li-silicate in the order. Especially Si$_2$O$_{5}$ $^{-2}$ crystalline regions were found to exist in Potassium silicate sample. Mixture of two kinds of silicate, for example, Lithium silicate when added to sodium silicate or potassium silicate was find to significantly reduce efflorescence and increase water resistance. This appears to be a result of stronger crosslinking between polysilicate particles by the small lithium cation.

• 한국세라믹학회지
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• 제22권1호
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• pp.25-34
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• 1985

The states of alkali occuring in Portland cement clinker were studied. Potassium was added to raw mixture by there kinds ; $K_2SO_4$, $K_2CO_3$ and KOH. In case of $K_2CO_3$ and KOH addition the new state of unstable alkali was found when alkakli content is high and $SO_3$ content is low in the clinker. Unstable state of highly basic free 4K_2O$ causes lowering burnability much more than alkali sulfate especially at the early stage of burning. Lowered burnability by 4K_2O$ became more serious with higher LSF. Unstable free-4K_2O$ which is readily soluble with water reacts with gypsum to form $Ca(OH)_2$ and syngenite as soon as water is added. As a results the liberation rate of heat of hydration at the early hydration process(1st peak) was increased.

• Bulletin of the Korean Chemical Society
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• 제21권10호
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• pp.989-994
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• 2000

• 미생물학회지
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• 제6권1호
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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.

• Preventive Nutrition and Food Science
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• 제15권1호
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• pp.78-82
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• 2010

This study investigated the effects of water-soluble calcium supplements manufactured with eggshells and oyster shells on growing rats. The aim was to review the potential use of food wastes as materials for water-soluble calcium supplements as compared to water-soluble calcium supplements made from imported seaweed powder. When experimental animals were administered three types of water-soluble calcium supplements orally for six weeks, the serum calcium level of the seaweed calcium supplement group were significantly higher than that of eggshell or oyster shell-derived calcium, but blood alkali phosphatase activity, osteocalcin and urine crosslink levels were not different in the three types of calcium supplements. Bone mineral density and bone mineral content in spine, femur and tibia also were not significantly different among the groups. However, when considering body weight of each group, bone mineral density and bone mineral content of the femur were significantly higher in the oyster shell calcium supplement group. These results suggest that at least on a short-term basis, the effect of calcium supplements prepared from eggshell and oyster shell are similar to the effects of seaweed calcium supplements.

• 농업과학연구
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• 제36권1호
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• pp.1-10
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• 2009

동양배 '신고'와 '사과배'의 저장기간 중 서로 다른 생리적 특성과 세포벽 특성 변화를 비교 검토하여 과실생리 및 저장기술의 기초자료로 얻고자 본 실험을 실시하였다. 저장 기간 중 '신고'의 품질변화는 중량감소가 큰 반면, '사과배'에서는 급격한 호흡급등현상과 에틸렌 생합성이 많았으며, 전분감소가 컸다. 수용성 펙틴함량은 '신고'가 '사과배'보다 높았으며 CDTA-가용성 펙틴은 두 품종간의 차이가 크지 않았다. $Na_2CO_3$-가용성 펙틴은 '사과배'가 '신고'보다 높았으며 수용성 펙틴과는 달리 저장 기간이 길어질수록 증가하였다. 4% 및 24% KOH 가용성 펙틴은 저장기간에 따른 변화 폭이 크지 않았다. 수용성 펙틴의 분획 결과,'신고'와 '사과배' 저장 중 거대 분자의 구조 변화에서 많은 차이를 보였고, '신고'와 '사과배' 모두 저장 기간이 길어질수록 펙틴의 가수분해 및 측쇄 사슬의 당 분해가 관찰되었다. $Na_2CO_3$-가용성 펙틴의 경우 당 분포는 저장 기간에 관계없이 일정하였지만 펙틴은 분자량 변화가 컸다. 4% 및 24% KOH 가용성 펙틴의 분획 결과 두 품종에 있어 헤미셀룰로스의 구조 변화가 서로 달라, '사과배'의 경우는 4% KOH 가용성 추출물의 분획에서 세포벽을 구성하고 있는 당들의 가수분해가 컸으며 '신고' 보다 '사과배'에서 노화 과정 중 헤미셀룰로스의 변화가 더 심하였다.

• Korea-Australia Rheology Journal
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• 제12권2호
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• pp.93-100
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• 2000

The interactions between methylated $\beta$-cyclodextrin (CD) and hydrophobically modified alkali-soluble associative polymers (HASE) were examined by a rheological technique. The effect of "capping" of hydrophobes by methylated $\beta$-cyclodextrin on the viscosity and modulus was evaluated. Model HASE polymers with $C_1$to $C_{20}$ alkyl hydrophobic groups ethoxylated with~10 moles of ethylene-oxide (EO 10) and at concentrations up to 3 wt% were examined. With the addition of methylated $\beta$-CD, the steady shear viscosity profiles shift from a Newtonian profile to one that display a shear-thinning characteristic. Significant "capping" of the hydrophobes occurs for HASE polymers with $C_{l2}$, $C_{16}$ and $C_{20}$ hydrophobes as reflected by the large reduction in the viscosity. However, the steady shear viscosity remains constant when the concentration of $\beta$-CD exceeds 1 wt%, suggesting that $\beta$-CD is not able to fully encapsulate the hydrophobes of the HASE polymer. The temperature variation plots indicate that the activation energy of the HASE-EO10-$C_{20}$ system and $\beta$-CD is dependent on the magnitude of the applied shear stress. These results further reinforce the hypothesis that $\beta$-CD is not able to completely remove all the hydrophobic associations.phobic associations.

• 미생물학회지
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• 제17권2호
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• pp.81-93
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• 1979

The mycelium of Rhizopus nigricans was harvested at intervals during the sporulation periods, fractioned into various cell components and analyzed the con!eiits of various cell materials in order to clarify the optimum conditions of sporulation and some characteristics of the metabolism during tke sporulation periods. The changes in enzyme activities, such as amylase and protease, were also measured during the sporulation period,. 1. Mycelium in distilled water culture, as control, did not sporulate but mycelial mat cultured in Petridish without mutrient spourulated. Optimum temperature range for sporulation was $20{\sim}25^{\circ}C$. 2. During the sporulation and maturation periods, proteins, especially alkali-labile protein were decreased remarkably but free amino acid and ninhydrin reactive substances in acid soluble fraction were increased, compared with control. 3. Acid solable polyphosphate was decreased but acid insoluble polyphosphate was increased, during the sporulation. 4. Carbohydrate and hexosamine in acid soluble fraction were increased, while carbohydrate in alkali insoluble residual fraction was decreased during the sporulation periods. 5. Amounts of UV-absorbing material in deoxyribonucleic acid fraction was increased a little but those in ribonucleic acid fraction was decreased, compared with control. 6. Intracellular amylases and proteases activities insporulating mycelial mat were increased continuously during the sporulation and maturation periods.

• Korea-Australia Rheology Journal
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• 제14권1호
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• pp.1-9
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• 2002

Steady and dynamic shear properties of two hydrophobically modified alkali soluble emulsions (HASE), NPJI and NPJ2, were experimentally investigated. At the same polymer concentration, NPJ1 is appreciably more viscous and elastic than NPJ2. The high hydrophobicity of NPJ1 allows hydrophobic associations and more junction sites to be created, leading to the formation of a network structure. Under shear deformation, NPJ1 exhibits shear-thinning behaviour as compared with Newtonian characteristics of NPJ2. NPJ1 and NPJ2 exhibit a very high and a low level of elasticity respectively over the frequency range tested. For NPJ1, a crossover frequency appears, which is shifted to lower frequencies and hence, longer relaxation times, as concentration increases. Three different surfactants anionic SDS, cationic CTAB, and non-ionic TX-100 were employed to examine the effects of surfactants on the rheology of HASE. Due to the different ionic behaviour of the surfactant, each type of surfactant imposed different electrostatic interactions on the two HASE polymers. In general, at low surfactant concentration, a gradual increase in viscosity is observed until a maximum is reached, beyond which a continuous reduction of viscosity ensues. Viscosity development is a combined result of HASE-surfactant interactions, accompanied by constant rearrangement of the hydrophobic associative junctions, and electrostatic interactions.