• Fashion & Textile Research Journal
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• 제9권1호
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• pp.119-123
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• 2007

Dyeing properties of soybean fabrics on gromwell colorants were studied for the effect of dyeing conditions, such as colorants concentration, temperature, time and pH on the dye uptake and effect of mordants on color change, dye uptake and various colorfastness. Antimicrobial activity of soybean fabrics dyed and sim-mordanted with gromwell colorants was examined by shake flask method. Gromwell colorants showed considerably affinity to soybean fabric and its isotherm adsorption curve was Freundlich type. Therefore, it is considered that hydrogen bonding and Van der Waals force were involved in the adsorption of gromwell colorants to soybean fabric. Soybean fabrics showed R color on Al, Cu and Sn mordant, RP color on Cr and Fe mordant, but soybean fabrics showed low dye uptake depending on mordanting treatment. Light colorfastness was increased for Cr and Fe mordants. Staphylococcus aureus reduction rates were above 90% for Cr and Cu mordanted soybean fabrics, and the others were poor. Klebsiella pneumoniae reduction rates soybean fabrics did not show reduction rate hardly.

• Journal of the Korean Society of Clothing and Textiles
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• 제26권1호
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• pp.124-132
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• 2002

Dyeing properties of silk fabric on gromwell roof colorants were studied for the effect of dyeing conditions, such as methanol ratio, colorants concentration, pH, temperature and time etc. on the dye uptake and effect of mordants and mordanting methods on color change and dye uptake. And various colorfastnesses of dyed fabrics were evaluated far practical use. Gromwell colorants showed high affinity to silk and its isotherm adsorption curve was Freundlich type close to Nernst type. Therefore, it is considered that hydrogen bonding and Van der Waals force were involved in the adsorption of cromwell colorants to silk fabric. Post-mordanting method gave higher K/S value than other methods, but it was not significantly different color values from unmordanted one. Gromwell colorants produced mainly R and RP color depending on mordants and mordanting method. Dyed fabrics showed high colorfastness irrespective of mordanting treatment. Light colorfastness was increased for repeatedly dyed and Fe mordanted dyed fabrics.

• Bulletin of the Korean Chemical Society
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• 제28권12호
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• pp.2459-2465
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• 2007

V2O5/TiO2-ZrO2 catalyst modified with V2O5 was prepared by adding Ti(OH)4-Zr(OH)4 powder into an aqueous solution of ammonium metavanadate followed by drying and calcining at high temperatures. The characterization of prepared catalysts was performed using XRD, DSC, solid-state 51V NMR, and FTIR. In the case of calcination temperature of 500 oC, for the catalysts containing low loading V2O5 below 25 wt % vanadium oxide was in a highly dispersed state, while for catalysts containing high loading V2O5 equal to or above 25 wt % vanadium oxide was well crystallized due to the V2O5 loading exceeding the formation of monolayer on the surface of TiO2-ZrO2. The strong acid sites were formed through the bonding between dispersed V2O5 and TiO2-ZrO2. The larger the dispersed V2O5 amount, the higher both the acidity and catalytic activities for acid catalysis.

• Journal of the Korean Ceramic Society
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• 제31권10호
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• pp.1231-1239
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• 1994

In this study, gel powder which had relatively high hydration reactivity in CaO and P2O5 rich composition of CaO-P2O5-SiO2-H2O system was prepared by sol-gel process and its hydrated specimen was manufactured. The it was investigated to appropriate calcination temperature in sol-gel process which hydrated specimen of gel powder have proven to strength and the effect of factors influenced strength in hydration process. The major product of before and after hydration reaction was hydroxyapatite, and crystalline phase of C-S-H was already formed during gelation process. After hydration reaction of pressed specimen, crystalline phase of C-S-P-H was formed. It was hydrated product of silicocarnotite (5CaO.P2O5.SiO2). Gel phases of C-S-H and C-S-P-H occured as a result of partial substitution of amorphous silica by P2O5 was formed. The strength of hydrated hardened body is developed by strong bonding and bridging between the gel phases of C-S-H or C-S-P-H and the crystalline products such as hydroxyapatite, Ca(OH)2 C-S-H and C-S-P-H. In addition, the ultrafine gel powder have an great effect on increase of hydration reaction.

• Journal of Magnetics
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• 제15권4호
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• pp.194-198
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• 2010

In our present work, we developed a GMI (giant magnetoimpedance) sensor system to detect magnetic fields in the milli gauss range based on the asymmetric magnetoimpedance (AGMI) effect in Co-based amorphous ribbon with self bias field produced by field-annealing in open air. The system comprises magnetoimpedance sensor probe, signal conditioning circuits, A/D converter, USB controller, notebook computer, and program for measurement and display. Sensor probe was constructed by wire-bonding the cobalt based amorphous ribbon with dimensions $10\;mm\;{\times}\;1\;mm\;{\times}\;20\;{\mu}m$ on a printed circuit board. Negative feedback was used to remove the hysteresis and temperature dependence and to increase the linearity of the system. Sensitivity of the milli gauss meter was 0.3 V/Oe and the magnetic field resolution and environmental noise level were less than 0.01 Oe and 2 mOe, respectively, in an unshielded room.

• Proceedings of the Korean Vacuum Society Conference
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• 한국진공학회 2010년도 제39회 하계학술대회 초록집
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• pp.171-171
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• 2010

In this work, we investigated the effect of the oxidation temperature on the unipolar and bipolar resistance switching behaviors of the oxidized TiO-x films. TiOx films on Pt electrodes were fabricated by the oxidation of Ti films at $550^{\circ}C$ for 1 to 3 hours. The unipolar and bipolar resistance switching properties were investigated with the oxidation temperature and time. Also, the crystal structure and the physical properties such as chemical bonding states of TiOx layers were characterized in addition to the resistance switching characteristics. The resistance switching behaviors of TiOx films oxidized at above $450^{\circ}C$ and below $650^{\circ}C$ was shown. So, we investigated that the resistance switching behaviors of TiOx films oxidized at $550^{\circ}C$ with the oxidation time from 1 to 3 hour. The memory windows of unipolar switching in the oxidized TiOx films were reduced with increasing the oxidation time, but those of the bipolar switching were slightly enlarged. The enlargement of rutile TiO2 peak with increasing the oxidation time and temperature was studied by X-ray diffraction. An increase of non-lattice oxygen and Ti3+ in the TiOx films with the oxidation times was investigated by X-ray photoemission spectroscopy. It was expected that the uipolar and bipolar resistive switching of the oxidized TiOx film was strongly related with the migration of non-lattice oxygen anions and schottky barrier height, respectively.

• Current Photovoltaic Research
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• 제1권1호
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• pp.63-68
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• 2013

We investigated the effects of Au eutectic reaction on Si thin film growth by hot wire chemical vapor deposition. Small SiC and Si nano-particles fabricated through a wet etching process were coated and biased at 50 V on micro-textured Si p-n junction solar cells. Au thin film of 10 nm and a Si thin film of 100 nm were then deposited by an electron beam evaporator and hot wire chemical vapor deposition, respectively. The Si and SiC nano-particles and the Au thin film were structurally embedded in Si thin films. However, the Au thin film grew and eventually protruded from the Si thin film in the form of Au silicide nano-balls. This is attributed to the low eutectic bonding temperature ($363^{\circ}C$) of Au with Si, and the process was performed with a substrate that was pre-heated at a temperature of $450^{\circ}C$ during HWCVD. The nano-balls and structures showed various formations depending on the deposited metals and Si surface. Furthermore, the samples of Au nano-balls showed low reflectance due to surface plasmon and quantum confinement effects in a spectra range of short wavelength spectra range.

• Journal of the Institute of Electronics Engineers of Korea SD
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• 제41권1호
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• pp.15-20
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• 2004

The interfacial layer between the oxide film and the metal film according to RTP annealing temperature of metal film has been studied. Two types of oxides, BPSG and PETEOS, were used as a bottom layer under multi-layered metal films. We observed the interface between oxide and metal films using SEM (scanning electron microscopy), TEM (transmission electron microscopy), AES (auger electron spectroscopy). Bonding failure was occurred by interfacial reaction between the BPSG oxide and the multi-layered metal films above $650^{\circ}C$ RTP anneal. The phosphorus accumulation layer was observed at interface between BPSG oxide and metal films by AES and TEM measurements. On the other hand, bonding was always good in the sample using PETEOS oxide as a bottom layer. We have known that adhesion between BPSG and multi-layered metal films was improved when the sample was annealed below $650^{\circ}C$.

• Publications of The Korean Astronomical Society
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• 제32권1호
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• pp.351-353
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• 2017

To realize large-format compact array detectors covering a wide far-infrared wavelength range up to 200 µm, we have been developing Blocked-Impurity-Band (BIB) type Ge detectors with the room-temperature surface-activated wafer bonding technology provided by Mitsubishi Heavy Industries. We fabricated various types of $p^+-i$ junction devices which possessed a BIB-type structure, and evaluated their spectral response curves using a Fourier transform spectrometer. From the Hall effect measurement, we also obtained the physical characteristics of the $p^+$ layers which constituted the $p^+-i$ junction devices. The overall result of our measurement shows that the $p^+-i$ junction devices have a promising applicability as a new far-infrared detector to cover a wavelength range of $100-200{\mu}m$.

• Journal of the Korea Academia-Industrial cooperation Society
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• 제15권12호
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• pp.7283-7286
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• 2014

SiOC films were prepared as insulators for displays by sputtering at low temperatures, and the relationship with the electrical properties waaas examined. The electrical properties of SiOC films were affected by the annealing process, and SiOC films annealed at 100oC showed a significant increase in thickness and a decrease in the reflective index. XRD revealed an increase in the degree of the amorphous structure. Moreover, the capacitance and leakage current of the SiOC films annealed at 100oC decreased. These characteristics of SiOC films highlight their potential as ideal insulators. Amorphous SiOC films by the reduction of polarization are dependent on the elongation effect of the bonding lengths in the structure and the thickness. The properties of these SiOC films are suitable for low temperature displays.