• Journal of the Korean Recycled Construction Resources Institute
• /
• v.4 no.2
• /
• pp.157-164
• /
• 2016

In this research, based on the condition of using desulfurization gypsum(FGD) as a stimulator for high-volume blast furnace slag cement mortar, sieving and heating process methods of removing activated carbon in FGD were compared with the non-processed FGD and recycled and natural fine aggregates were compared for suitable aggregate to be used. According to the result of experiment, sieving with 0.3mm was more efficient than $500^{\circ}C$ heating for processing the FGD, and recycled fine aggregate showed more favorable result than natural fine aggregate at the FGD content was 5 to 10%. On the other hand, the mortar mixture including recycled fine aggregate had a high drying shrinkage, and absorption ratio, and thus specific limitations on applying recycled fine aggregate should be required.

• Journal of the Korean Recycled Construction Resources Institute
• /
• v.6 no.3
• /
• pp.167-173
• /
• 2018

In general, calcium is required for the reaction of blast furnace slag fine powder and fly ash. The by-products generated during the process of producing recycled aggregates have different calcium contents depending on the crushing stage and the possibility of using the process by-product as a concrete mixture is also different. In this study, the effect of the calcium content of the by-products on the compressive strength was investigated and the block was fabricated by using this. To utilize the by-products as an admixture, the calcium content was analyzed and the bending strength and surface temperature were measured according to the shape of the water storage block. As a result of this study, the possibility of making a block using recycled aggregate by-products was verified and arch type block was constructed to secure storage capacity and bending strength. Also, the surface temperature of the water storage block was reduced by $9^{\circ}C$ or more than that of the general permeable block.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.4 no.1
• /
• pp.59-66
• /
• 1975

Silkworm and silkworm-chrysalis as an edible insect have been investigated. Through this investigation, the following results are obtained : 1) Silkworm and silkworm-chrysalis as a good source of protein-rich compound was examined, and they contained 54.9% to 56% protein as a crude protein. 2) Except tryptophan, almost all the essential amino acids contained. The amount of the amino acids was on the increased as much as the silkworm growth. 3) The following amino acids was not detected on the silkworm fibron analysis, aspartic acid, glutamic acid, cystine and methionine. But the following amino acid were relatively high amount : glycine, alanine, and tyrosine. 4) Sucrose, fructose, and glucose as a carbohydrates was investigated, the results are from 0.312% to 0.313% as an invert sugar; 0.289% to 0.305% as a glucose; 0.333% to 0.412% as a fructose. 5) The acidity and pH of the milk was examined according to the silkworm-chrysalis powder added. added material was not effected as far as the milk was change. Therefore, the milk and the silkworm-chrysalis mixture are being a good drinkable things.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
• /
• 2001.10a
• /
• pp.660-664
• /
• 2001

$Zn_xSr_{1-x}S$ thin films were prepared in the whole composition range by rf sputtering, using powder targets of a mixture of ZnS and SrS with the required mole fraction. The possibility of existence of $Zn_xSr_{1-x}S$ solid solutions was systematically investigated from the results of thin film growth, in terns of structural, optical characteristics and the chemical bonding of the constituent atoms. The XRD, XPS and optical results made it clear that the solid solutions with a single-phased zincblende structure and a single-phased rocksalt structure were formed at $0.86~0.93{\leq}x{\leq}1$ and $0{\leq}x{\leq}0.29$, respectively. The miscibility gap, including phase separation regions was found to exist in $0.3{\leq}x{\leq}0.86~0.91$, in which lattice constants, binding energy and absorption edges kept almost constant by the same values as those at border compositions. The experimental results on phase transition agreed well with the fraction of ionic character $f_{i}$ based on the Phillips'dielectric theory.

• Resources Recycling
• /
• v.8 no.4
• /
• pp.57-63
• /
• 1999

Wood-Polymer Composites (WPC) m s prepared irom recycled films of agricullural use and wood wastes, and LLDPE and neal PE resin mlxlurr war also utilized in order to cornpiue the praperlies. Molc~ca nhydride (MA) and dicumyl peroxide were used as an adheslon pmmoler and an il~lliatotor~, .espcmivelyT. ensile prapenies of W Cw zrc measured via lenslle test as a funclieu of woad lille~m d MA contmt, and rractu1.e surface was also mvestigaled wilh SEM. As the content of wwd tiller mcreased, clongauon deneased bul modulus increased However, tensile slrength OI WPC increased only when MA war used, and 1 wt.% of MA may be hgh enough to increase the tensile properties. The tensilc ptopcrlies af WPC prepwed from recycled PE films were &nost same as thosc of neal PE resin mixture.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2007.11a
• /
• pp.57-60
• /
• 2007

This study is to discuss the effect of the liquid type high early strength agent considering early strength, developing strength, and economics of the concrete using admixtures. The powder type high early strength agent does not helpful because the field application is not available such as the problem of mixing process and rack of economics. To make up these subjects, the plain mixture contains the standard type AE water reducing agent, and the types of the agents are the standard type AE water reducing agent(P),liquid type high early strength agent(AD),poly carboxylate high early strength type AE water reducing agent(E1), and naphthalene + melamine high early strength type AE water reducing agent(E2). As the Contents of the agents, E1 and E2 is two types each cases, and P is one type to satisfy the target fluidity and air content, AD is three types as 0.5, 1.0,and 1.5%. In the case that AD is mixed, the fluidity is decreased, but air content is increased. For increasing strength of the early age, using OPC is more effective than FA and BS for increasing the early strength of the concrete, and if the air content is secure as plain, the effect of the developing strength can be increased because the air content is increased about 2% in the case that AD is used.

• Archives of Pharmacal Research
• /
• v.20 no.3
• /
• pp.259-263
• /
• 1997

In the preparation of acyclic thymidine nucleoside analogues, $K_2CO_3$(or NaH) treated thymine in DMSO was alkylated with .omega.-chloroalkyl nitrite (Cl-(CH_2)n-CN; n=1, 2, 3, 4) to provide an isomeric mixture of 1-(${\omega}$-cyanoalkyl)thymine (2a-d) and 1,3-bis(${\omega}$-cyanoalkyl)thymine in approximately 5:1 ratios. Reduction of the cyano function 2a-d with $NaBH_{4}/CoCl_{2}$ center dot$ 6H_{2}O$gave the corresponding 1-(${\omega}$aminoalkyl)thymine (3a-d). The newly formed primary amino function in 3a-d was directly reacted with 2-chloroethylisocyanate to afford the 1-[.omega.($N^{I}$-2-chloroethylureido) alkyl]thymine (4a-d) in good yields. Nitrosation of 1-[5-($ N^{I}-2$-chloroethylureido)pentyl] thymine (4d) with glacial acetic acid and dry $NaNO_{2}$-powder in anhydrous $CH_{2}Cl_{2}$gave two types of regioisomeric nitrosoureas, 1-[5-($N^{I}$--chloroethyl-$N^{I}$--nitrosoureido)pentylithymine (5d) and 1-[5-($N^{I}-2$-chloroethyl-N-nitrosoureido)pentyllthymine in approximately 5 :1 ratios. The in vitro cytotoxicity of the synthesized compounds (2a-d, 3a-d, 4a-d and 5a-d) against three cell lines (K-562, P-388 and FM-3A) are measured as $IC^{50}$ values. Compounds 3b and 4c showed moderate activities against all three cell lines, and all other compounds were found to be not active.

• Journal of Forest and Environmental Science
• /
• v.21 no.1
• /
• pp.24-33
• /
• 2005

Fallen needles (8.5kg) of Larix kaempferi were separately collected, extracted with 95% EtOH. EtOH extract was evaporated under reduced pressure, concentrated then successively fractionated with a series of hexane, methylene chloride, ethylacetate and water on a separatory funnel. Then, each fraction was freeze dried. A portion of ethylacetate and water soluble powder were packed on a column chromatography (Sephadex LH-20) eluting with aqueous MeOH and EtOH-hexane mixture. Spectrometric analyses such as NMR and FAB-MS including TLC were performed to characterize the structures of isolated compounds. 5 compounds were isolated from the fallen needles of Larix kaempferi. The antioxidative activities of each fraction and isolated compounds were done by DPPH radical scavenging test.

• Transactions of the Korean hydrogen and new energy society
• /
• v.24 no.1
• /
• pp.29-35
• /
• 2013

A dense mixed ionic and electronic conducting ceramic membrane is one of the most promising materials because it can be used for separation of oxygen from the mixture gas. The $ABO_3$ perovskite structure shows high chemical stability at high temperatures under reduction and oxidation atmospheres. $BaCo_{1-x-y}Fe_xZr_yO_{3-{\delta}}$ (BCFZ) was well-known material as high mechanical strength, low thermal conductivity and stability in the high valence state. Glycine Nitrate Process (GNP) is rapid and effective method for powder synthesis using glycine as a fuel and show higher product crystallinity compared to solid state reaction and citrate-EDTA method. BCFZ was fabricated by modified glycine nitrate process. In order to control the burn-up reaction, $NH_4NO_3$ was used as extra nitrate. According to X-Ray Diffraction (XRD) results, BCFZ was single phase regardless of Zr dopants from y=0.1 to 0.3 on B sites. The green compacts were sintered at $1200^{\circ}C$ for 2 hours. Oxygen permeability, methane partial oxidation rate and hydrogen production ability of the membranes were characterized by using Micro Gas Chromatography (Micro GC) under various condition. The high oxygen permeation flux of BCFZ 1-451 was about $1ml{\cdot}cm^{-2}s^{-1}$. Using the humidified Argon gas, BCFZ 1-433 produced hydrogen about $1ml{\cdot}cm^{-2}s^{-1}$.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.60 no.11
• /
• pp.2083-2087
• /
• 2011

The SiC-$ZrB_2$ composites were produced by subjecting a 40:60 vol.% mixture of zirconium diboride($ZrB_2$) powder and ${\beta}$-silicon carbide (SiC) matrix to spark plasma sintering(SPS). Sintering was carried out for 60sec at $1400^{\circ}C$ (designation as TP145 and TP146), $1500^{\circ}C$(designation as TP155 and TP156) and uniaxial pressure 50MPa, 60MP under argon atmosphere. The physical, electrical, and mechanical properties of the SiC-$ZrB_2$ composites were examined. The relative density of TP145, TP146, TP155 and TP156 were 94.75%, 94.13%, 97.88% and 95.80%, respectively. Reactions between ${\beeta}$-SiC and $ZrB_2$ were not observed via x-ray diffraction (hereafter, XRD) analysis. The flexural strength, 306.23MPa of TP156 was higher than that, 279.42MPa of TP146 at room temperature, but lower than that, 392.30MPa of TP155. The properties of a SiC-$ZrB_2$ composites through SPS under argon atmosphere were positive temperature coefficient resistance (hereafter, PTCR) in the range from $25^{\circ}C$ to $500^{\circ}C$. The electrical resistivities of TP145, TP146, TP155 and TP156 were $6.75{\times}10^{-4}$, $7.22{\times}10^{-4}$, $6.17{\times}10^{-4}$ and $6.71{\times}10^{-4}{\Omega}{\cdot}cm$ at $25^{\circ}C$, respectively. The densification of a SiC-$ZrB_2$ composite through hot pressing depend on the sintering temperature and pressure. However, it is convinced that the densification of a SiC-$ZrB_2$ composite do not depend on sintering pressure under SPS.