• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2005.05a
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• pp.441-445
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• 2005

In the resent years, as the research and the development of micro and precision machinery become active, the interest of micro actuators using SMA(Shape Memory Alloy) has been increased. But, no detailed researches between the thermo-dynamic property in Nitinol alloy have been done yet. In this study, the thermal property of high temperature Nitinol shape memory alloy were evaluated using differential scanning calorimeter(DSC). The structure property was investigated using X-ray diffraction(XRD). A dynamic mechanical analyzer(DMA) with three point bending mode was used to study storage and loss modulus of shape memory alloy according to the thirteen frequencies in the temperature range between 30 and $200^{\circ}C$. The effects of the temperature heating/cooling rate, the frequency on the damping capacity have been systematically investigated. Such a frequency and temperature changes also influenced significantly to the damping behavior of the shape memory alloy. It was also found that Nitinol exhibited high damping capacity during phase transformation.

• Journal of the Semiconductor & Display Technology
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• v.11 no.2
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• pp.75-80
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• 2012

Polymer composites which have electrical properties have been studied in various industries. The Multi-walled carbon nanotube (MWCNT) are thought to be reinforcements for polymers because of their high aspect ratio and specially mechanical, thermal and electrical properties. We introduced MWCNT and impact modifier in order to improve thermal and mechanical properties of Polyphenylene sulfide (PPS) and give electric characteristic to PPS. The thermal properties were investigated by Differential scanning calorimeter (DSC) and Thermogravimetric analysis (TGA). The morphology, mechanical properties and electrical characteristic were performed by Field emission scanning electron microscopy (FE-SEM), Izod impact tester and surface resistance meter. As a result, we could find that the PPS/MWCNT composites have high conductivity and good mechanical properties than neat PPS resin.

• Clean Technology
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• v.12 no.1
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• pp.27-35
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• 2006

Main compositions of powder paint based on thermoset type epoxy resin consist of epoxy resin for powder coating, curing agent, filler and pigment. The curing system used in this study was based on diglycidyl ether of bisphenol-A (DGEBA) and dicyan diamide (DICY). The curing behavior and rheological properties of powder coating material were investigated using DSC and rheometer, respectively. And the adhesion strength between steel and powder coating material was measured using lap shear geometry. The optimum formulation of epoxy powder paint obtained from this study was base resin of 100 phr, DICY of 6 phr, $CaCO_3$ of 20 phr, and $TiO_2$ of 10 phr.

• Applied Chemistry for Engineering
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• v.10 no.7
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• pp.1008-1013
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• 1999

Mechanical properties and morphology of pectin/starch blend films depending upon the composition and plasticizer ratio were studied. Blends were prepared continuously in a twin-screw extruder. Films were prepared using a single-screw extruder with slit die. Most of the blends showed a good thermoplastic behavior, while the blends with very high ratio of pectin/starch had a poor thermoplasticity. Tensile properties of blend films were changed significantly by the amount of glycerol and relatively little by the ratio of pectin/starch. Differential scanning calorimetry(DSC) curves of wet blends showed a transition similar to glass transition temperature(Tg) at about $125^{\circ}C$. It was found by Scanning electron microscopy(SEM) study that there exists a good interfacial adhesion between pectin and starch.

• Journal of the Korean Society of Clothing and Textiles
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• v.12 no.3 s.28
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• pp.343-350
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• 1988

This study was carried out to investigate the microstructure and physical property of PET POY which was taut-annealed under various conditions. The DSC melting curves of annealed PET POY showed double melting peaks in most cases. As temperature and time increased, form II crystal became sharp and increased in size, and form I crystal decreased in size. The slower the heating rate, the higher the programmed heating effect during DSC analysis. Crystallinity and briefringence of annealed specimens increased as the treatment temperature and time increased. Breaking tenacity of specimens treated for 3 minutes increased as the treatment temperature increased, but others decreased. Elongation at break decreased as the annealing temperature and time increased. Dye uptake of annealed specimens decreased as the temperature increased up to $190^{\circ}C\~210^{\circ}C$. then the uptakes increased at higher temperatures. At the same temperature, dye uptake of the specimen decreased as time increased.

• Food Science and Biotechnology
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• v.16 no.5
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• pp.832-835
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• 2007

Moisture content of normal, waxy, and high amylose com starches was adjusted to 10-35%, and irradiated in a microwave oven. The effect of microwave irradiation on the crystalline structure of starch was measured by using a differential scanning calorimetry (DSC), and X-ray diffractometry. Pasting viscosity profile was also determined by using a rapid viscoanalyzer (RVA). For all the 3 types of starches tested, the rate of temperature increase by the microwave irradiation was faster and more rapidly reached the maximum temperature of the pressure bomb ($120^{\circ}C$) when the moisture content was higher. X-ray diffraction and DSC data revealed that the microwave irradiated starch underwent partial disruption of crystalline structure. RVA studies showed that the irradiation caused significant reductions in maximal viscosity and breakdown, whereas pasting temperature was increased. Overall trends revealed that the microwave irradiation on the starch containing limited moisture content (less than 35%) provided the effects similar to the heat moisture treatment. These effects became more significant when the moisture content was higher. Compared to waxy com starch, normal, and high amylose com starches appeared to be more susceptible to the microwave irradiation.

• Journal of Pharmaceutical Investigation
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• v.39 no.2
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• pp.107-110
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• 2009

To investigate the interaction and skin damage of valsartan with polysorbate 80, the physical mixture of valsartan and polysorbate 80 was prepared and then its adhesion, dispersibility, DSC and skin damage in nude rats were investigated. The physical mixture of valsartan and polysorbate 80 appeared as an aggregated form and could hardly be dispersed in water. The DSC curve showed that physical mixture disappeared the intrinsic peaks of valsartan and polysorbate 80 at about $115^{\circ}C$ and $170^{\circ}C$, respectively. It appeared a new relatively broad endothermic peak at about $150^{\circ}C$, suggesting that valsartan was chemically interacted with polysorbate 80. Furthermore, it induced the severe skin irritation and damage in nude mice. Thus, polysorbate 80 must not be used in the preparation of valsartan-loaded pharmaceutical dosage forms.

• KIEE International Transactions on Electrophysics and Applications
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• v.3C no.2
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• pp.59-65
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• 2003

Electrical properties such as permittivity and tan$\delta$ of unaged (control) and aged (72 h at 18$0^{\circ}C$) mica/epoxy composites of 130 ${\mu}{\textrm}{m}$ thickness were measured and their surface conditions were characterized using scanning electron microscopy (SEM), Fourier transform infrared (FTIR), electron spectroscopy for chemical analysis (ESCA), differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Both permittivity and tan6 of control specimens were higher than those of short-time aged specimens. FTIR results show a new peak at 1710 $cm^{-1}$ / for short-time aged specimens, originating from carbonyl group formed by the oxidation reaction during the aging process. ESCA results show that the binding energy at 532.9 eV representing the singlet state of oxygen ( $O_{1s}$) decreases by 13.7%, whereas that at 534.6 eV increases by 13.7%. Glass transition temperatures of control and short-time aged specimens are observed to be 95.4$^{\circ}C$ and 113.4$^{\circ}C$, which increase with the increase of aging time. TGA results indicate that the control specimens contain a smaller amount of volatile components than the short-time aged specimens.s.

• Journal of Adhesion and Interface
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• v.14 no.4
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• pp.167-174
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• 2013

In this study, Ultraviolet (UV) curable urethane acrylates for ink binder was prepared by reaction of IPDI, polyether polyol and HEA. The UV curing behavior of compositions with HEA/PETA ratio on UV irradiation time was investigated by FT-IR spectrophotometer, probe tack tester and Photo-DSC. Conversion % and gel content were increased with increasing UV irradiation time, but probe tack was decreased. Storage modulus, tensile strength and decomposition temperature were increased as PETA content increased. In case of HEA/PETA ratio was 30/70, adhesion property of UV-cured composition on PMMA sheet was excellent.

• Journal of Applied Biological Chemistry
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• v.50 no.4
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• pp.234-238
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• 2007

The effects of ultra-fine pulverization on the physicochemical properties of rice starch (RS) were investigated using a high impact planetary mill. After pulverization, RVA characteristics, peak viscosity, break down, and set back values of RS decreased from 274.75 to 9.42 RVU, 214.46 to 6.17 RVU, and 87.80 to 17.00 RVU, respectively. The pasting properties also changed significantly. X-Ray diffractogram revealed RS had four A-type peaks, which disappeared after pulverization. The peak temperature and gelatinization enthalpy of RS using differential scanning calorimetry (DSC) were 13.99 J/g at $75.14^{\circ}C$, whereas the pulverized RS (PRS) had two peaks, 0.13 J/g at $63.88^{\circ}C$ and 1.23 J/g at $101.24^{\circ}C$. DSC measurement showed the retrogradation degree of PRS was lower than that of RS after storage at 4 and $25^{\circ}C$. The enzymatic (${\alpha}$-amylase) digestibilities of RS and PRS were 72.7 and 77.3%, respectively.