• Fisheries and Aquatic Sciences
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• v.15 no.1
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• pp.63-67
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• 2012

A comparative study of bile acid components from four lamprey species revealed that mature male chestnut lamprey Ichthyomyzon castaneus can produce 3 keto petromyzonol sulfate (3kPZS) while mature males of Pacific lamprey Lampetra tridentata, river lamprey Lampetra fluviatilis and American brook lamprey Lethenteron appendix produce petromyzonol sulfate (PZS). Identification of 3kPZS from a group of ancient lamprey species and of PZS from recently derived species led to a speculation that differentiation of bile acid biosynthetic systems has taken place during the course of evolution. Further studies on the biological functions of different bile acids in the adult lampreys are required to understand the evolution of chemical communication in lampreys.

• Bulletin of the Korean Chemical Society
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• v.22 no.12
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• pp.1303-1308
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• 2001

A series of catalysts, NiSO4/TiO2, for ethylene dimerization was prepared by the impregnation method using aqueous solution of nickel sulfate. On the basis of the results obtained from X-ray diffraction, the addition of NiSO4 shifted the transition of TiO2 from the anatase to the rutile phase toward higher temperatures due to the interaction between NiSO4 and TiO2. Nickel sulfate supported on titania was found to be very active even at room temperature. The high catalytic activity of NiSO4/TiO2 closely correlated with the increase of acidity and acid strength due to the addition of NiSO4. It is suggested that the active sites responsible for ethylene dimerization consist of low valent nickel, Ni+, with an acid.

• Journal of the Korean Home Economics Association
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• v.17 no.1
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• pp.12-19
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• 1979

Five kinds of soybean curd were propared with five coagulants, such as, calcium sulfate, calcium chloride, magnesium chloride, glucono delta lactone and acetic acid. The products were evaluated by the sensory and objective examination. Optimal concentrations of each coagulant were determined. Soybean curd preparation was also standardized. The textural characteristics of the five soybean curds which were made by the standard recipe were measured by a Texturometer and a Penetrometer. The results were as follows : 1. From the proliminary study, the optimal concentration of coagulants for the soybean curd preparation, as determined by the sensory evaluation was 1.84% of calcium sulfute, 1.05% of calcium chloride. 1.84% of calcium sulfute, 1.05% of calcium chloride. 1.84% of magnesium chloride, 1.97% of glucono delta lactone and 0.48% 11of acetic acid. 2. As the result of the sensory evaluation, the most acceptable soybean curd was determined to be one with acetic acid. Next, in order of accetability , were magnesium chloride, calcium chloride, glucono delta lactone, calcium sulfate soybean curds and commerical soybean curd. 3. Through the objective examination of the five soybean curds by a Texturometer and a Penetrometer, it was found out that, calcium sulfate soybean curd was the hardest and the hardness decreased in order of glucono delta lactone, magnesium chloride, calcium chloride, and acetic acid soybean curd. Acetic acid soybean curd, the most acceptable , was 0.47 TU ; and calcium sulfate soybean curd, the least acceptable, was 1.73 TU.

• Korean Journal of Animal Reproduction
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• v.16 no.1
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• pp.7-14
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• 1992

These experiments were designed to investigate the effects of glycosaminoglycans(GAGs), which maybe produced by cumulus cells, on in vitro maturation process of bovine follicular oocytes. The rates of in vitro maturation of bovine oocytes were examined after incubating with the various concentrations of a hyaluronic acid, chondroitin sulfate, or heparin for 26 hours. The results obatained in these experiments were summarized as follows : 1. When the cumulus or removed oocytes treated with hyaluronic acid(200, 400, 800 and 1, 600$\mu\textrm{g}$/ml), the maturation rates of cumulus-removed oocytes were 48.6, 59.4, 68.4 and 61.3% respectively. Especially, at a concentration of 800$\mu\textrm{g}$/ml, the maturation rates(68.8%) of cumulus-removed oocytes were slightly lower than that(78.3%) of cumulus-enclosed oocytes. However, the treatment of hyaluronic acid showed significantly higher maturation rates compared to that(48.4%) of control group of cumulus-removed oocytes(p<0.05). Therefore, these results suggest thate hyaluronic acid had a beneficial effect on maturation of bovine follicular oocytes. 2. The maturation rate of cumulus-free oocytes treated with chondroitin sulfate(200, 400, 800 and 1, 600$\mu\textrm{g}$/ml) was 52.3, 56.1, 55.9 and 52.2% respectively. These rates were not different from those(52.9%) of control group. However, these rates in cumulus-free oocytes were significantly lower than that(79.0%) in cumulus-enclosed oocytes(p<0.01). Therefore, these results suggest that chondroitin sulfate do not affect on the maturation of oocytes. 3. In cumulus-free oocytes cultured with different heparin concentration, the maturation rates were ranged from 48.5 to 52.1%, showing no differencies from that(50.7%) of control group. However, these rates were significantly lower than 80.0% in cumulus-enlosed oocytes(p<0.01). 4. The nuclear maturaton of oocytes was increased by treatment of each of three glycosaminoglycans(hyaluronic acid, chondroitin sulfate, and heparin). In addition, the treatment of mixed together showed the significant additive effect. Hyaluronic acid was more effective than chondroitin sulfate and heparin were.

• Bulletin of the Korean Chemical Society
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• v.26 no.2
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• pp.292-296
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• 2005

Physical and chemical properties of thexylboronic acid and its derivatives such as thexylboroxine and ethylene glycol or diethanolamine thexylboronic ester have been studied. Thexylboronic acid can be extracted from an organic solution with an aqueous sodium hydroxide solution as an “te”complex. It is readily converted into thexylboroxine in the presence of anhydrous magnesium sulfate in pentane. It reacts with simple alcohols only slowly; however, it reacts readily with excess diethanolamine in the presence of anhydrous magnesium sulfate to give the corresponding ester.

• Proceedings of the KSEEG Conference
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• 2000.04b
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• pp.258-259
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• 2000

• Journal of Environmental Science International
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• v.17 no.9
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• pp.981-992
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• 2008

This study examined how to produce new methods of copper (II) sulfate crystallization by using a small-scale chemistry tool such as small-scale reaction surface and petri dish. The making of copper(II) sulfate is included in the 5th grade elementary science textbooks. Various copper(II) compounds were reacted with a 2 M sulfuric acid solution. The result of this study is as follows: Seven small amounts of copper(II) compounds were reacted with a few drops of 2 M sulfuric acid solution at room temperature to make a copper(II) sulfate crystal of triclinic shape. Using the petri dish method, a copper(II) sulfate crystal could be identified within one hour of reacting copper(II) hydroxide, copper(II) carbonate, copper(II) nitrate, copper(II) perchlorate, cupric(II) formate from a few drops of 2 M sulfuric acid solution at room temperature. When using the lap top method for copper(II) perchlorate, cupric formate, a proper crystal could be identified within one hour as well. SSC methods were used for the first time to make a copper sulfate crystal via chemical reaction. We can make a copper(II) sulfate crystal using a simple method which is easier, safer and saves time in class. And since a small quantity of chemicals are being used in SSC chemical methods, waste is greatly reduced. This lessens the amount of environmental problems caused by the experiment. This can be helpful in preserving nature. In addition the cost of chemical and laboratory equipment is greatly reduced because it uses material that we find in our daily lives. There will be continued study of small-scale methods such as improvement of new programs, study and training of teachers, and securing SSC tools. I would like to suggest such as SSC methods are applicable in elementary School Science. I would like it to become a wide spread program.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2015.11a
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• pp.11-12
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• 2015

This study analyzed sulfate resistance of strongly acid-resistant inorganic binder based on industrial byproducts. According to the study experiment, compared to OPC mixture, the mixture of high acid-resistant inorganic binder had excellent chemical resistance against 10% H₂SO₄ solution. In the case of ordinary portland cement, its sample with 28 days of immersion had severe corrosion on its mortar erosion part, and thus external appearance was damaged greatly, and compression strength decreased by around 57% and more.

• YAKHAK HOEJI
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• v.4 no.1
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• pp.43-46
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• 1959

A new quantitiative analytical method of prussic acid by "Microdiffusion analysis" was studied. HCN-Glucoside of ARMENIACA was hydrolysed with KOH in out-room of unit, and then concentrated sulfuric acid was poured in order to liberate the HCN gas. The liberated gas was absorbed into nickel sulfate solution of inner room of unit quantitatively. The excess of nickel sulfate was determined by EDTA Reagent using MX-indicator. By this method, the following results were obtained: (1) It was needed more than 4 hours, in order to hydrolyse completely at $50^{\circ}C$, but could be shortened to 3 hrs. at $^60{\circ}C$. (2) It was completely absorbed into nickel sulfate solution after 30min.

• Korean Journal of Animal Reproduction
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• v.16 no.1
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• pp.15-20
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• 1992

These experiments were undertaken to investigate the rate of in vitro fertilization of bovine follicular oocytes treated with glycosaminoglycans(GAGs). Bovine follicular oocytes were obtained from the ovary of slaughtered animal and matured in media containing the various concentrations of hydluronic acid, chondroitin sulfate or heparin for 26 hours. Epididymal spermatozoa were capacitated and insemination was made by introducing about 10~15 matured oocytes into the suspension of spermatozoa. Six hour after insemination the eggs were transferred to TCM-199 supplemented with FCS(10%) and then examined the embryo development. After in vitro insemination, percentages of ova fertilized were 61.3 or 48.3%, respectively, for the cumulus intact or removed in the percentages of GAGs. However, in case of cumulus-free oocytes treated with GAGs, the fertilization rates were 58.8, 62.1, 58.8, and 61.8%, respectively, showing significant effect compared to 48.3% in cumulus-free oocytes. Our findings suggest that cnondroitin sulfate and heparin are superior to hyaluronic acid in the fertilizatin and pronuclear formation of bovine oocytes.