• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2003.02a
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• pp.117-119
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• 2003

YBa$_2$Cu$_3$O$_{7-{\delta}}$(YBCO) high temperature superconducting thin films were grown on SrTiO$_3$single crystal substrates by pulsed laser deposition(PLD). The texture and lattice parameter of the YBCO films were analysed using the GADDS (general area detector diffraction system) which enables XRD analyses to be done faster and with fewer sample movement than with the XRD system with point detector. The XRD results of the films grown in different deposition conditions are reported together with the SEM microstructure analysis results.ysis results.

• Macromolecular Research
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• v.11 no.1
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• pp.14-18
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• 2003

Grafting of glycidyl methacrylate (GMA) upon coralline hydroxyapatite in conjugation with demineralized bone matrix (CHA-DBM) using equal molar ratio of potassium persulfate/sodium metabisulfite redox initiating system was investigated in aqueous medium. The optimum reaction condition was standardized by varying the concentrations of backbone, monomer, initiator, temperature and time. The results obtained imply that the percent grafting was found to increase initially and then decrease in most of the cases. The optimum temperature and time were found to be 50 $^{\circ}C$ and 180 min, respectively, to obtain higher grafting yield. Fourier transform infrared (FT-IR) spectroscopy and X-ray powder diffraction (XRD) method were employed for the proof of grafting. The FT-IR spectrum of grafted CHA-DBM showed epoxy groups at 905 and 853 $cm^{-1}$ / and ester carbonyl group at 1731 $cm^{-1}$ / of poly(glycidyl methacrylate) (PGMA) in addition to the characteristic absorptions of CHA-DBM, which provides evidence of the grafting. The XRD results clearly indicated that the crystallographic structure of the grafted CHA-DBM has not changed due to the grafting reaction. Further, no phase transformation was detected by the XRD analysis, which suggests that the PGMA is grafted only on the surface of CHA-DBM backbone. The grafted CHA-DBM will have better functionality because of their surface modification and hence they may be more useful in coupling of therapeutic agents through epoxy groups apart from being used as osteogenic material.

• Bulletin of the Korean Chemical Society
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• v.21 no.1
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• pp.56-60
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• 2000

The mechanism of a matrix modification for the trace determination of volatile lead and bismuth by an electro-thermal atomic absorption spectrophotometry was studied by a X-ray diffractometry (XRD). For the investigation of structures, the ash products of the elements were produced by using a palladium as a matrix modifier with or without aluminum or nickel as an auxiliary modifier. The same charring conditions as in the analysis of samples were applied together with much concentrated solution of analytical elements and modifiers in a graphite furnace to get a large amount of the product for XRD. The XRD patterns showed PbPd3 for lead and BiPd3 for bismuth. These mean that the reaction procedures through the charring and atomization were changed from $Pb^{2+}$ ${\rightarrow}$ PbO ${\rightarrow}$$Pb^0$ to $Pb^{2+}$ ${\rightarrow}$ PbO ${\rightarrow}PbPd_3$ ${\rightarrow}$ Pb o for lead and from $Bi^{3+}$ ${\rightarrow}$ BiO ${\rightarrow}$ Bi o to $Bi^{3+}$ ${\rightarrow}$ BiO ${\rightarrow}$ $BiPd_3$ ${\rightarrow}$ $Bi^0$ for bismuth by the addition of modifiers. The volatile elements were stabilized by the formation of palladium alloys through a charring process. Charring temperatures were raised about 500 $^{\circ}C$ by the alloying and the atomization was also stabilized for the enhancement of sensitivities.

• Journal of the Korean institute of surface engineering
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• v.56 no.4
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• pp.250-258
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• 2023

Ceramic oxide layer was formed on the surface of high silicon aluminum alloy by using PEO (plasma electrolytic oxidation) process. The microstructure of the oxide layer was analyzed using scanning electron microscopy (SEM) and x-ray diffraction patterns (XRD). The high silicon aluminum alloy prior to PEO process consists of Al, Si and Al₂Cu phases in XRD analysis, whereas Al₂Cu phase selectively disappeared after PEO treatment. Considerable decrease of relative intensity in most of peaks in XRD results of the high silicon aluminum alloy treated by PEO process was observed. It may be attributed to the formation of amorphous phases after PEO treatment. The corrosion behavior of the high silicon aluminum alloy treated by PEO process was investigated using electrochemical impedance spectroscopy (EIS) and other electrochemical techniques (i.e., open circuit potential and polarization curve). Electroanalytical studies indicated that the high silicon aluminum alloy treated by PEO process shows greater corrosion resistance than that untreated by PEO process.

• Analytical Science and Technology
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• v.21 no.6
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• pp.553-561
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• 2008

$CNT/TiO_2$ composites were prepared by using multiwall carbon nanotubes (MWCNT) and various titanium alkoxide precursors. The composites were comprehensively characterized by scanning electron microscopy (SEM), field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX) and UV-vis absorption spectroscopy. The photoactivity of the prepared materials under UV irradiation, was tested using the conversion of MB from model aqueous solution. Finally, according to the results of methylene blue (MB) removal experiment, we could see that sample CTOS have better MB removal effect than samples CTIP and CTPP.

• Journal of the Korean Society of Visualization
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• v.22 no.1
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• pp.18-27
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• 2024

A series of shock wave pulses with Mach number 2.2 of 100, 200, and 300 shocks were applied to lead sulfide (PbS) nanomaterials at intervals of 5 sec per shock pulse. To investigate the crystallographic, electronic, and magnetic phase stabilities, powder X-ray diffractometry (XRD), diffused reflectance spectroscopy (DRS), and vibrating-sample magnetometry (VSM) were employed. The material exhibited a rock salt structure (NaCl-type structure); XRD results indicated that material is monoclinic with space group C121 (5). Further, XRD results showed shifts due to lattice contraction and expansion when material was subjected to shock wave pulses, indicating stable material structure. Based on the data obtained, we believe that the PbS material is a good choice for high-pressure, high-temperature, and aerospace applications due to its superior shock resistance characteristics.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.85-85
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• 2010

In this paper, each specimen blended at weight proportions of 80% HDPE to 20% EVA, 70% HDPE to 30% EVA, 60% HDPE to 40% EVA, and 50% HDPE to 50% EVA was manufactued respectively. FE-SEM, DSC and XRD analysis were carried out as the means of structural and chemical analysis. From the results of DSC and XRD analysis, the lower contents in blended specimens were, the higher melting temperature and crystallinity of main crystal were. It seems that the phenomena was attributes to themoplastic interpenetrating network effect(TPIPN) in which EVA having low melting point penetrated into HDPE. Also, from the decreasing tendeancy of melting point as a function of blend ration, it was confirmd that above resins have compatibility. The thermal and mechanical performance of proposed insulator were compared with conventional XLPE, main insulating material of CV cable. Also, validity was proved by superior and inferior factor respectively.

• Journal of the Korean Home Economics Association
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• v.41 no.8
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• pp.55-62
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• 2003

Natural dyes generally fan into two categories; organic dyes coming from animals and plants and inorganic dyes obtained from various minerals such as bengala, loess, ultramarine, prussian blue and etc. The main components of volcanic ash is clay mineral such as kaolinite, illite, quartz. Clay minerals Composing volcanic ash are kaolinite［$Al_4Si_4O_{10}{(OH)_{8}}$］, illite［$K_{X}Al_2(Si,\;Al)_4O_{10}{(OH)}_2$］, quartz［$SiO_2$］, homblende［$Na_{0-1}\;Ca_2{(Mg,\;Fe,\;Al)}_5{(Si,\;Al)}_{8}O_{22}{(OH)}_2$］and etc. And the redish color mainly comes from iron oxide. In this paper, two different classes of dyeing process were tested; dyeing with volcanic ash only and cationic agent pre-treatment followed by dyeing with volcanic ash. The compositions of the volcanic ash powder and the volcanic ash deposited on the cotton knitted fabrics identified by energy dispersive spectrometer and XRD analysis. The major chemical components of volcanic ash deposited on the cotton knitted fabrics were confirmed to be the saicon oxide, iron oxide, and aluminum oxide and etc. According to the analysis by XRD and EDS-SEM, kaolinite, illite and quartz were also identified.

• Journal of the Korean institute of surface engineering
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• v.32 no.6
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• pp.709-716
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• 1999

Ceramic is select for an alternative substrate material for high-speed circuits due to its low-thermal expansion. As, in this study, ceramic was prepared by ISG (interlayer sol-gel) process using metal salts and a metal alkoxide as the starting materials. Generally ceramic substrate is used electroless copper plating for the metallization. But it has been indicate weakely the adhesion strength between the substrate and copper layer. Therefore, this research, using the ISG process on the preparation of homogeneous and possible preparation at law temperature fabricated sol solution. Using of the dip coating method was coated for the purpose of giving the anchoring effect on the coating layer and enhancing the adhesion strength between the $Al_2$O$_3$ substrate and copper layer. This study examined primary the characteristic of the sol making condition and differential thermal analysis (DTA) X-ray diffraction (XRD) were mearsured to identify the crystal phase of heat treatment specimens. The morphology of the coated films were studied by scanning electron microscopy(SEM). As a resurt, XRD analysis was obtained patterns of $\alpha$-cordierite after heat-treatment about 2 hours at $1000^{\circ}C$. SEM analysis could have seen a large number of voids on coated film. The more contants of$ Al_2$$O_3$ Wt% was increased the more voids was advanced. Peel adhesion strength has a maximum in the contants of the TEOS:ANE of 1:0.7 mole%. In this case, adhesion strength has been measured 1150gf, peel adhesion strength were about 10 times more than uncoated of the ceramics film.

• Electrical & Electronic Materials
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• v.9 no.4
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• pp.404-409
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• 1996

The structural and electric properties of $Y_{1-x}$YbF$_{x}$Ba$_{2}$Cu$_{3}$O$_{7-y}$(x=0.0, 0.1, 0.2, 0.3, 0.4, 0.5 and 0.6) have been investigated by using XRD(X-ray diffraction), TMA(thennomechanical analysis), NMR(nuclear magnetic resonance) analysis and four probe method. $Y_{1-x}$YbF$_{x}$Ba$_{2}$Cu$_{3}$O$_{7-y}$ samples were prepared by conventional solid-state reaction method using $Y_{2}$O$_{3}$, BaCO$_{3}$, CuO and YbF$_{3}$ power. TMA and high temperature XRD results shows that orthorhombic to tetragonal phase transition occurs in the unfluorinated 1-2-3 sample while the phase change is not observed in the fluorinated 1-2-3 samples. Superconducting transition temperature(T$_{c}$) increases with increasing YbF$_{3}$ content ; T$_{c}$, of the sample reaching maximum of 102K for x=0.3, and then decreases with further increasing YbF$_{3}$ content. The structural analysis and T$_{c}$ results shows that the fluorine doping stabilize the orthorhombic phase, together with the increase in T$_{c}$.}$ c/.TEX> c/.