• The Korean Journal of Ceramics
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• v.4 no.2
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• pp.95-98
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• 1998

We have developed new type of superconducting-superionic conducting nanohybrids, $Ag_xI_wBi_2Sr_2Ca_{n-1}Cu_nO_y$ (n=1 and 2) by applying the chimie douce reaction to the superconducting Bi-based cuprates. These nanohybrids can be achieved by the stepwise intercalation whereby the $Ag^+$ ion is thermally diffused into the pre-intercalated iodine sublattice of $IBi_2Sr_2Ca_{n-1}Cu_nO_y$. According to the X-ray diffraction analysis, the Ag-I intercalates are found to have an unique heterostructure in which the superionic conducting Ag-I layer and the superconducting $IBi_2Sr_2Ca_{n-1}Cu_nO_y$ layer are regularly interstratified with a remarkable basal increment of ~7.3$\AA$. The systematic XAS studies demonstrate that the intercalation of Ag-I accompanies the charge transfer between host and guest, giving rise to a change in hole concentration of $CuO_2$ layer and to a slight $T_c$ change. The Ag K-edge EXAFS result reveals that the intercalated Ag-I has a $\beta$-AgI-like local structure with distorted tetrahedral symmetry, suggesting a mobile environment for the intercalated $Ag^+$ ion. In fact, from ac impedance analyses, we have found that the Ag-I intercalates possess a fast ionic conductivity ($\sigma_i=10^{-1.4}\sim 10^{-2.6}\Omega^{-1}\textrm{cm}^{-1}\;at\;270^{\circ}C$ with an uniform activation energy ($\DeltaE_a=0.22\pm 0.02$ eV). More interesting finding is that these intercalates exhibit high electronic conducting as well as ionic ones ($t_i$=0.02~0.60) due to their interstratified structure consisting of superionic conducting and superconducting layers. In this respect, these new intercalates are expected to be useful as an electrode material in various electrochemical devices.

• Applied Biological Chemistry
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• v.26 no.4
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• pp.255-260
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• 1983

In order to examine the effect of storage conditions on lipid and minor elements compositions of sesame seed, the changes in general characteristics and fractionation pattern o the lipid, and such minor elements as sesamol, sesamolin and sesamin were analyzed during the storage of sesame seeds for 4, 9, and 15 months at the four different storage conditions, that is, storage under light with linen pouch(LA), storage in dark with linen pouch(DA), storage under light with polyethylene pouch(LS) and storage in dark with poly ethylene pouch(DS). The acid value were increased significantly during the storage for 4 to 9 months then continued same acid value with prolonged storage until 15 months, but iodine value were increased continuously until 15 months in all the storage conditions, and the increasing tendency of the value at LA and DA was higher than that at LS and DS. Steryl ester was increased in the LA but decreased in DS with prolonged storage until 15 months. Diglyceride was increased during the storage in alt the storage conditions and increasing tendency in LA was higher than that in DS and LS. The free fatty acid contents were significantly increased until g months of storage, then similar value was continued with prolonged storage. Phospholipid was decreased with prolonged storage until 15 months and decreasing tendency in DA and LA was sharper than that in LS and DS. The content of free sesamol was ranged from 0.0021 to 0. 0058% of total lipid. Free sesamol was increased but bound sesamol was decreased during the storage for 15 months in all the storage conditions. Sesamolin was ranged from 0.11 to 0.19% of total lipid and decreasing tendency during the storage was similar to free sesamol.

• Applied Biological Chemistry
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• v.24 no.1
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• pp.59-66
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• 1981

Trichoxanthes Kirilowii with high starch-content was investigated to utilize as a food source. The weight and starch content of Trichoxanthes Kirilowii roots increased rapid1y in proporion to the growth period. The seasonal variations of the starch content were $36.5{\sim}48.0%$ (dry basis) from June to December. The chemical properties of natural growth soils of Trichoxanthes Kirilowii contained more organic matter and total nitrogen content than citrus orchard soils, but less mineral; P,K,Ca and Mg. To prepare starch with the plant root, the centrifugal method(3,000 rpm, 20 min) obtained the highest yield. The industrial-scale method, was similar to the processing of sweetpotato starch (tank precipitation method), and was good in quality. The starch granules were mainly spherical with diameters ranging from $5{\sim}16{\mu}$. The density of the starch was 1.535 and amylose content was about 26.7%. The X-ray diffraction pattern showed that the granules were of the B-type. The blue value of starch, amylose and amylopectin was 0.46, 0.80 and 0.18, respectively. The starch contained 0.05% ash, 0.35% crude protein and 34 mg% phosphorus. and had an inital pasting temperature of $63.5^{\circ}C$. The color intensity of the starch which iodine gave rise to absorption maxima at 670nm. The starch paste showed high stability during cold storage at $5^{\circ}C$.

• Journal of the Korean Wood Science and Technology
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• v.4 no.1
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• pp.3-7
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• 1976

This is to reveal the chemical properties of resin of Pinus koraiensis Sieb. et Zvcc, and to give the basic data to resin chemistry and resin processing field. Its results are given; 1) Acid value was shown as 134.12 2) Saponification value was shown as 172.72 3) Iodine value was shown as 109.93 and therefore, it is considered as semi-boiled oil. 4) Ester value was shown as 41.60 5) Moisture content was shown as 11.28% 6) The impurities of resin was shown as 0.09% 7) The amount of turpentine oil was shown as 23.29% 8) Rosin content was shown as 76.74% 9) The amount of resin acid was shown as 72.33% 10) Unsaponification matter was shown as 4.41% 11) The refractive index of resin was shown as 1.5045 at $N^{20}_D$.

• Nuclear Engineering and Technology
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• v.4 no.3
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• pp.186-193
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• 1972

For efficient micro scale syntheses of Rose $Bengal-^{131}I$, $Hippuran-^{131}I$, and $H.S.A.-^{131}I$, the dependence of labelling yields on pH, on salt contents, and on the volume of buffer solution in the reaction mixtures as well as the reaction apparatus were studied. pH of 5.6 was optimum for preparation of both Rose $Bengal-_{131}I$ and Hippuran $-^{13}I$ but pH of 8.5 was optimum for preparation of $H.S.A.-^{131}I$. Salt in the reaction mixtures hindered drastically the formation of $Hippuran-^{131}I$ but it slightly increased the labelling yield of H.S.A.. The compactly closed reaction vessels were effective for preparations of both Rose $Bengal-^{131}I$and $Hippuran-^{131}I$ in small volume. Thereupon, the labelling procedures were modified to bring about higher labelling yields and better reproducibilities. By these newly established procedures, the labelling yields of Rose $Bengal-^{131}I$ and $Hippuran-^{131}I$ could be increased even with the home-produced sodium $iodide-^{131}I$ solution containing reducing agent.

• Transactions of the Korean hydrogen and new energy society
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• v.23 no.1
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• pp.1-7
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• 2012

This study was performed to develop a low Pt content catalyst as a catalyst for HI decomposition in S-I process. Bimetallic catalysts added various amounts of Pt on a silica supported Ni catalyst were prepared by impregnation method. HI decomposition was carried out using a fixed bed reactor. As a result, Ni-Pt bimetallic catalyst showed enhanced catalytic activity compared with each monometallic catalyst. Deactivation of Ni-Pt catalyst was not observed while deactivation of Ni monometallic catalyst was rapidly occurred in HI decomposition. The HI conversion of Ni-Pt bimetallic catalyst was increased similar to Pt catalyst with increase of the reaction temperature over a temperature range 573K to 773K. From the TG analysis, it was shown that $NiI_2$ remained on the Ni(5.0)-Pt(0.5)/$SiO_2$ catalyst after the HI decomposition reaction was decomposed below 700K. It seems that small amount of Pt in bimetallic catalyst increase the decomposition of $NiI_2$ generated after the decomposition of HI. Consequently, it was considered that the activity of Ni-Pt bimetallic catalyst was kept during the HI decomposition reaction.

• Korean Journal of Food Science and Technology
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• v.13 no.2
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• pp.127-132
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• 1981

Studies on the physico-chemical properties of acetone-solubles from Torreya nucifera seeds, the composition, and chemical structure of desmethylsterol from the lipids are summarized as follows; 1. The acetone-soluble lipids and moisture content of Torreya nucifera seeds amounted to 46.6% and 9.3%, respectively. 2. The unsaponifiable content, iodine value, and saponification value of the lipids were 0.3%, 122 and 189.3, respectively. 3. The desmethylsterols comprised three components, whose Rrts (1.5% OV-17 to ${\beta}$-sitosterol) corresponded to 1.09 (trace), 1.16 (trace) and 1.33 (98%). 4. From IR, mass and NMR spectrometric features, the prominent desemethylsterol appears to be 24(?)-ethylcholesta-5-en-3${\beta}$-ol.

• Korean Chemical Engineering Research
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• v.50 no.3
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• pp.551-555
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• 2012

Desorption reaction characteristics of the commercial activated carbons which were used for the removal of industrial odorants were investigated. BET specific surface area was analyzed to investigate the chemicophysical property of activated carbon. Adsorptivity of activated carbon was estimated by iodine number. Thermogravimetric analyzer (TGA) was used to investigate the desorption characteristics. Activation energies and reaction orders for reaction characteristics according to adsorption and desorption of activated carbons were estimated by employing the Friedman method and Freeman-Carroll method. Adsorptivity of reprocessed activated carbons were significantly lower than that of fresh activated carbons. In this study, it was found that the activation energies were 15.9~23.4 kJ/mol in Friedman method and 22.7~33.8 kJ/mol in Freeman-Carroll method.

• Transactions of the Korean hydrogen and new energy society
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• v.27 no.1
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• pp.13-21
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• 2016

The Sulfur-Iodine thermochemical hydrogen production process (SI process) consists of the Bunsen reaction section, the $H_2SO_4$ decomposition section, and the HI decomposition section. The $HI_x$ solution ($I_2-HI-H_2O$) could be recycled to Bunsen reaction section from the HI decomposition section in the operation of the integrated SI process. The phase separation characteristic of the Bunsen reaction using the $HI_x$ solution was similar to that of $I_2-H_2O-SO_2$ system. On the other hands, the amount of produced $H_2SO_4$ phase was small. To investigate the effects of $SO_2$ solubility on Bunsen reaction, the continuous Bunsen reaction was performed at variation of the amounts of $SO_2$ gas. Also, it was carried out to make sure of the effects of partial pressure of $SO_2$ in the condition of 3bar of $SO_2-O_2$ atmosphere. As the results, the characteristic of Bunsen reaction was improved with increasing the amounts and solubility of $SO_2$ gas. The concentration of Bunsen products was changed by reverse Bunsen reaction and evaporation of HI after 12 h.

• Journal of Soil and Groundwater Environment
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• v.19 no.1
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• pp.1-7
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• 2014

When processing the biomass by Hydrothermal carbonization (HTC), a slow pyrolysis process, it produces bio-gas, biooil, and biochar. Among these end products, biochar is known for isolating or storing carbon and being used as a soil amendment. In this study, the characteristics of biochar generated by HTC at $250^{\circ}C$ for 1 hour, 2 hours, 3 hours, and 20 hours with synthetic food wastes and wood wastes were analyzed for potential uses in soil contaminated with heavy metals. The yield of biochar (weight %) increased when the ratio of wood wastes increased and showed a decreasing tendency as reaction time increased. Elemental analysis of biochar based on various conditions showed a maximum of 70% carbon (C) content. The carbon content showed an increasing tendency with the increase of wood wastes. Iodine adsorption test was peformed to determine the optimum reaction condition, which was 15% wood waste for mixing ratio and 2 hours for reaction time. Using biochar generated at the optimum condition, its capability of adsorbing heavy metals (Cd, Cu, Pb, Zn, Ni) was evaluated. It was concluded that lead (Pb) was removed efficiently while zinc (Zn) and nickel (Ni) were hardly adsorbed by biochar.