• Textile Coloration and Finishing
• /
• v.7 no.4
• /
• pp.61-73
• /
• 1995

Inorganic salts have negative or positive effects on the rates of many chemical reactions and also the rates of acidic and alkaline hydrolysis of carboxylic esters. The direction of salt effects on the hydrolysis of ester depends on the charge of esters. It is expected that the rate of the alkaline hydrolysis of Poly(ethylene terephthalte)(PET), polymeric solid carboxytic polyester with carboxyl end group at the polymer end, is also influenced by inorganic salts. In the present work, to clarify the effect of divalent cations on the alkaline hydrolysis of PET, many salts with divalent cations like $MgCl_{2},CaCl_{2},SrCl_{2},BaCl_{2},$ were added to the aqueous alkaline solutions. Then PET was hydrolyzed with aqueous NaOH solution having many salts under various conditions. Some conclusions obtained from the experimental results were summarized as follows. Many salts with various divalent cations increased or decreased the reaction rate of alkaline hydrolysis of PET depending on their electrophilicity, hydration property, ability of ion pair formation, solubility, and the degree of interactions between divalent cations and anions, etc. The hydrolysis was interrupted in the order of $Ca^{+2} and was generally accelerated in the order of $Ba^{+2}. It was inferred from the increase in ΔS$^*$and the decrease in the ΔG$^*$that the divalent cations $Sr^{+2}$ and $Ba^{+2}$attracted by PET increased the collision frequency between carbonyl carbon and $OH^{-}$ion and then accelerated the reaction rate. $Mg^{+2}$and $Ca^{+2}$decreased the reaction rate because of their strong interaction with $OH^{-}$.

• Journal of Sericultural and Entomological Science
• /
• v.33 no.2
• /
• pp.87-92
• /
• 1991

The shrinkages and physical properties of silk yarn were studied on the effect of treatment concentration, time and temperature with various neutral salts. The degummed silk yarn was shrunk about 35 percent by highly concentrated solution of Ca(NO3)2 on conditions of S.G.(special gravity) 1.45 at 9$0^{\circ}C$ or S. G. 1.46 at 8$0^{\circ}C$. About 40 percent of silk yarn was contracted in length by the treatment of CaCl2 solution on conditions of S. G. 1.33 at 9$0^{\circ}C$ for 5 mins. or at 85$^{\circ}C$ for 10 mins. By treating the concentrated solution of LiBr the silk yarn showed about 40 percent of shrinkage on a conditions of S. G. 1.38, $25^{\circ}C$ 24hrs. The physical properties of salt-treated silk yarn could be significantly changed with shrinkage variations. There were some differences in shrinkages between different type of salts. However, it was observed that generally the tenacity was decreased and breaking elongation increased as the shrinkage increased. The bulkiness of salt-treated silk yarn was increased by 110 to 120 percent compared with untreated yarn.

• Journal of Industrial Technology
• /
• v.31 no.A
• /
• pp.59-62
• /
• 2011

The demineralizing effect of chelating agents(Maleic acid solution, EDTA salts solutions; disodium-, trisodium- and tetrasodium-EDTA) on hydroxyapatite(HA) for the root canal dentin treatment was investigated. Dissolution of Ca from HA was increased with increasing immersion time in chelating solutions. Among the EDTA salts solutions, tetrasodium-EDTA was least effective in dissolving Ca out from HA, and trisodium-EDTA was the most effective. Trisodium-EDTA solutionmight be more effective in removing the smear layer compared to tetrasodium-EDTA solution.

• International Journal of Industrial Entomology and Biomaterials
• /
• v.27 no.2
• /
• pp.326-328
• /
• 2013

Sericin undergoes gelation by the structural transition from random coil to b-sheet transition. In the present study, the gelation time of sericin solution was investigated in the presence of NaCl, KCl and $CaCl_2$. The addition of salts delayed the gelation time, and $CaCl_2$ had the most pronounced effect, which delayed about 8 h at maximum. The gelation time increased with the concentration of salt. The transition of secondary structure of sericin was retarded in the presence of salt. The effect of salts on the gelation time of sericin might be due to the solvation effect of relevant cation.

• Asian Journal of Atmospheric Environment
• /
• v.10 no.4
• /
• pp.190-196
• /
• 2016

The objective of this study is to obtain the optimal conditions to remove hydrogen fluoride (HF) generated from a variety of F-gas treatment processes. First, we selected $Ca(OH)_2$ and $CaCO_3$ as a reactant among the various alkali salts which have a high removal efficiency and a competitive price by forming a calcium fluoride precipitate. Additionally, various factors were investigated to improve the removal efficiency of HF. The conditions such as the settling time, agitating time and intensity, reaction temperature, and pH were considered as main factors. As a result, in the treatment process to remove HF through Ca-based alkali salts, the optimal conditions were a 120 min settling time, 30 min of agitation at 100 rpm, a pH of 4-8, and a reaction temperature of $40^{\circ}C$.

• BMB Reports
• /
• v.44 no.5
• /
• pp.341-346
• /
• 2011

The single-stranded DNA binding activity of the Escherichia coli RecA protein is crucial for homologous recombination to occur. This and other biochemical activities of ssDNA binding proteins may be affected by various factors. In this study, we analyzed the effect of $CaCl_2$, NaCl and $NH_4NO_3$ salts in combination with the pH and nucleotide cofactor effect on the ssDNA-binding activity of RecA. The studies revealed that, in addition to the inhibitory effect, these salts exert also a stimulatory effect on RecA. These effects occur only under very strict conditions, and the presence or absence and the type of nucleotide cofactor play here a major role. It was observed that in contrast to ATP, ATP${\gamma}$S prevented the inhibitory effect of NaCl and $NH_4NO_3$, even at very high salt concentration. These results indicate that ATP${\gamma}$S most likely stabilizes the structure of RecA required for DNA binding, making it resistant to high salt concentrations.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.20 no.6
• /
• pp.565-571
• /
• 1991

A short time microwave heat treatment, bringing in hot NaCl solution, addition of KCI, CaCl2, MgCl2 into brining solution and salts mixture of phosphates into half fermented dongchim were investigated for their effects on some quality of dongchimi, a Korean pickle of Chinese radish roots, during fermentation. The reference dongchimi was prepared by brining the radish roots in 7% NaCl added with seasonings at $25^{\circ}C$. The result showed that microwave heat treatment affected little on the pH or total acidity change during fermentation. Soaking the roots in 80-9$0^{\circ}C$ hot salt solution significantly reduced the fermentation and softening rate of dongchimi while a rather rapid fementation was found for those soaked in 7$0^{\circ}C$. Addition of KCI and CaCl2 into brining solution slowed the pH decrease and softening of the roots, respectively. The dangchimi added with the salts mixture of phosphate, citrate and nitrite was significantly extreneded the fermentation time to pH 4.0 by more than two folds.

• Korean Journal of Food Science and Technology
• /
• v.27 no.3
• /
• pp.336-341
• /
• 1995

Effect on alginate, pectin and Ca salts on textural properties of whole soybean gel(soygel) was investigated. The soygel was prepared by addition of sodium alginate, pectin and Ca salts into whole soy flour(300 mesh, WSF) suspension followed by through mixing. Addition of sodium alginate or pectin into WSF suspension significantly increased the hardness, adhesiveness and cohesiveness of the gel. The most uniform gel was obtained by $12{\sim}15%$ addition of sodium alginate or pectin, while their mixture rather decreased the textural properties. Sensory evaluation by ranking test for the gels showed that 12% sodium alginate and 0.125g $CaSO_4/g$ WSF produced the most desirable gel in terms of elasticity, uniformity, smoothness and total acceptability, followed by 12% sodium alginate and 0.12g Ca $gluconate-CaSO_4$(50 : 50). From the results, the optimal preparative conditions for soygel were suspension of WSF in 10 times of water(v/w), addition of 12% sodium alginate(w/w of WSF) and 12.5% $CaSO_4$ or Ca $gluconate-CaSO_4$(50 : 50) into WSF suspension followed by gel formation at $4^{\circ}C$.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.37 no.10
• /
• pp.1307-1311
• /
• 2008

This study was conducted to evaluate the quality characteristics of mugwort-tofu prepared by purified salt (A1), sun-dried salt (A2), bamboo salt (A3), and deep ground water salt (A4) in addition to $CaCl_2$ as coagulants. Addition of various salts with $CaCl_2$ increased yield of the tofu resulting in high content of lipid, protein and mineral contents of mugwort-tofu. Sun-dried salt was most effective in yield of the tofu among tested salts. It was also most efficient in increasing protein, and lipid contents of the tofu. The amounts of Ca, K, Mg, and Na were highest in mugwort-tofu prepared with sun-dried salt, while they were lowest in the tofu with deep ground water salt. The texture analysis showed the tofu prepared with various salts generally increased the hardness and gumminess of the tofu significantly. The sensory evaluation of the tofu with various salts demonstrated that the saltiness, tastiness, chewiness, and overall acceptance were enhanced significantly. Among tested salts, bamboo salt showed the highest overall acceptance in mugwort-tofu, followed by deep ground water salt, purified salt, and sun-dried salt.

• Journal of Plant Biology
• /
• v.12 no.3
• /
• pp.1-7
• /
• 1969

The lethal actions in Arabidopsis thaliana and Lemna polyrhiza brought about by certain inorganic form of Mn, Ba, Hg, Cu salts, and organic form of Na salts, were studied with aseptic artificial media. These metal ions at certain concentrations caused lethality of either Arabidopsis or Lemna when the media were without Ca ion. On the contrary, addition of Ca to the media protected the organisms from such lethality. It was postulated for the present from the proceeding evidence that Ca adsorbed and distributed along the sites between the plasma and cell membrane acts for suppressing permeation of toxic level of metal ions causing the lethality of these plants.