• Applied Chemistry for Engineering
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• v.25 no.1
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• pp.14-19
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• 2014

Nanocomposites based on poly(methyl methacrylate) (PMMA)/poly(vinylidene fluoride) (PVDF) and poly(ethylene terephthalate) (PET)/(PVDF) blended with carbon fibers (CF) and carbon nanotube (CNT) were prepared by melt mixing in the twin screw extruder. Morphologies of the PMMA/PVDF/CF/CNT and PET/PVDF/CF/CNT nanocomposites were investigated using SEM. The aggregation of CNT was observed in PMMA/PVDF/CF/CNT nanocomposites while the good dispersion of CNT was shown in PET/PVDF/CF/CNT nanocomposites. In SEM image of PET/PVDF/CF/CNT nanocomposite, the CNT were mainly located at the PET domain of phase-separated PET/PVDF blend due to the ${\pi}-{\pi}$ interaction between the phenyl ring of PET and graphite sheet of the CNT's surface. In addition, a fairly good compatibility between PET/PVDF matrix and CF was shown in the SEM image. In the case of PET/PVDF nanocomposites blended with the co-addition of CF and CNT, the volume electrical resistivity decreased while no change was observed in PMMA/PVDF/CF/CNT composites. The degree of CNT dispersion in morphology results was consistent with the electrical conductivity results. From the DSC results, the crystallization temperature (Tc) of PET/PVDF/CF/CNT nanocomposites increased due to the co-addition of CF and CNTs acting as a nucleating agent. Flexural modulus of PET/PVDF/CF/CNT were sharply enhanced due to increasing the interaction between PET and CF.

• Progress in Medical Physics
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• v.17 no.3
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• pp.173-178
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• 2006

The purpose of this study was to evaluate the radiation dose for clinical PET/CT protocols in clinical environments using Alderson phantom and TLDs. Radiation doses were evaluated for both Philips GEMINI 16 slice PET/CT system and GE DSTe 16 slice PET/CT system. Specific organ doses with $^{137}Cs$ transmission scan, high quality CT scan and topogram in philips GEMINI PET/CT system were measured. Specific organ doses with CT scan for attenuation map, CT scan for diagnosis and topogram in GE DSTe PET/CT system were also measured. The organs were selected based on ICRP60 recommendation. The TLDs used for measurements were selected for within an accuracy of ${\pm}5%$ and calibrated in 10 MV X-ray radiation field. The effective doses for $^{137}Cs$ transmission scan, high qualify scan, and topogram in Philips GEMINI PET/CT system were $0.14{\pm}0.950,\;29.49{\pm}1.508\;and\;0.72{\pm}0.032mSv$ respectively. The effective doses for CT scan to make attenuation map, CT scan to diagnose and topogram in GE DSTe PET/CT system were $20.06{\pm}1.003,\;24.83{\pm}0.805\;and\;0.27{\pm}0.008mSv$ respectively. We evaluated the total effective dose by adding effective dose for PET Image. The total PET/CT doses for Philips GEMINI PET/CT (Topogram+$^{137}Cs$ transmission scan+PET, Topogram+high qualify CT+PET) and GE DSTe PET/CT (Topogram +CT for attenuation map+ PET, Topogram+diagnostic CT+ PET) are $7.65{\pm}0.951,\;37.00{\pm}1.508,\;27.12{\pm}1.003\;and\;31.89{\pm}0.805mSv$ respectively. Further study may be needed to be peformed to find optimal PET/CT acquisition protocols for reducing the patient exposure with good image qualify.

• Fashion & Textile Research Journal
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• v.11 no.3
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• pp.474-480
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• 2009

The purpose of this study is to prepare the hardness of polyester(PET) fabric by thermal bonding with low melting component of bicomponent fiber and to describe the change of physical properties of thermal bonded PET fabrics. The PET fabrics were prepared with regular PET fiber as warp and bicomponent fiber as weft. The bicomponent fiber of sheath-core type were composed with a regular PET core and low melting PET sheath. The thermal bonding of PET fabric was carried out in pin tenter from 120 to $195^{\circ}C$ temperature range for 60 seconds. In this study, we investigated the physical properties and melting behavior of PET fiber and the effect of the temperature of the pin tenter on the thermal bonding, mechanical properties. Melting peak of warp showed the thermal behavior of general PET fiber. However, melting peak of weft fiber(bicomponent fiber) showed the double melting peak. The thermal bonding of the PET fabric formed at about temperature of lower melting peak. The optimum thermal bonding conditions for PET fabrics was applied at $190{\sim}195^{\circ}C$ for 60seconds by pin tenter. On the other hand, the tensile strength of the PET fabric decreased with an increasing temperature of thermal bonding.

• Journal of the Korean Home Economics Association
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• v.36 no.8
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• pp.95-104
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• 1998

PET microfiber fabric dissociation reactions by ethylene glycol (EG) catalayzed by the corresponding EG anions were examined to provide an empirical basis for the improvement of a PET microfiber fabrics. The alkoxide ions, monosodium ethylene glycolate in ethylene glycol solution(MSEG-EG) are prepared by the reaction between NaH and the EG respectively. The dissociation reactions were carried out until the sample PET microfiber fabrics dissociate up to 80%. Temperature used ranged 100~$160^{\circ}C$. The kinetic behaviors of the dissociated PET microfiber fabrics were examined. The results are as follows : 1. In all cases, it was found that the PET-alkoxide dissociation rate constants increased exponentially with increasing temperature. The activation energies (Ea) of the reactions were 23.31kcal/mol in PET-EG system respectively. The calculated enthalpies of the activated [PET-EG] complexes from the corresponding Ea values were 22.53 ~ 22.61 kcal/mol, and the entropies were -19.03 ~ -19.24 kcal/mol/k respectively. 2. The kinetic behavior of the PET-alkoxide dissociation reactions examined was explained by the transition state theory. PET-alkoxide transition state is believed to be formed during the ester interchange mechanism between PET and MSEG-EG in the course of the PET dissociation reactions.

• The Journal of Korean Society for Radiation Therapy
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• v.25 no.1
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• pp.41-47
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• 2013

Purpose: To evaluate the usefulness of Integrated PET/CT and compare the gloss tumor volume (GTV) identified on CT, PET, PET/CT to that obtained from fluorodeoxyglucose (FDG). Materials and Methods: This experimental study was obtained using GE Discovery 690 (General Electric Healthcare, Milwaukee, MI, USA) PET/CT simulator with Gammex Laser System for five non-small cell lung cancer (NSCLC) patients. In order to increase the reproducibility of the patient setup, We have to fixed to patients using the Extended Wing Board. GTV delineation was painted using the EclipseTM ver.10 contouring program for CT, PET, PET/CT images. And then, We were to compare the changes in the GTV. Results: These results are drawn from 5 patients who have atelectasis or pneumonitis. Compared to CT defined GTV, PET was decreased by 10.5%, 11.8% and increased by 67.9%, 220%, 19.4%. PET/CT was decreased by 7.7%, 6.7%, 28% and increased by 232%, 24%. Conclusion: We were able to determine the usefulness of PET/CT simulator for NSCLC. PET/CT simulator in radiation therapy is useful to define the target volume and It is possible to delineate Objective and accurate target volume. It seems to be applicable to other areas in the near future.

• Fashion & Textile Research Journal
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• v.14 no.6
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• pp.1024-1031
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• 2012

The thermal bonding PET fabrics were produced through high temperature steaming (HTS) of low melting PET yarn as warp and composite fancy yarn containing low melting PET yarn as weft. The low melting PET yarn of sheath-core structure consisted of a regular PET in core portion and low melting PET in sheath portion. The composite fancy yarn consisted of regular PET yarn as inner part and effect part and low melting PET yarn as binding part. This study was carried out to investigate the melting behavior of thermal bonded PET fabric, the effect of HTS on the thermal bonding, mechanical properties, and dyeing properties. The melting peak of low melting PET yarn showed two melting peaks caused by sheath-core structure. Almost the entire thermal bonding of the fancy PET fabrics containing low melting PET yarn has formed at $200^{\circ}C{\times}3min$ of HTS. The tensile strength in warp and weft direction of the fancy PET fabrics slightly decreased as temperature of HTS increased. The total K/S value of the fancy PET fabrics decreased slightly to $180^{\circ}C{\times}3min$ of HTS, while increased slightly above $200^{\circ}C{\times}3min$ of HTS. The changes in the hue angle ($H^{\circ}$) of the thermal bonded fancy PET fabrics dyed with disperse dyes hardly ever happened.

• Applied Chemistry for Engineering
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• v.5 no.1
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• pp.54-62
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• 1994

Bisphenol A polycarbonate(PC) and polyethylene terephthalate(PET) was blended with methylmethacrylate-butadiene-styrene(MBS) copolymer for the improvement of impact resistance strength PC/PET alloy blending with PC more than 15 parts to 100 parts of PET usually have poor compatability, but increased the compatability characteristics of PC/PET alloy prepared by addition of MBS compatabilizer. The compatability of PC and PET using compatabilizer, MBS was determined by measuring the thermal characteristics of Tg difference between PC and PET, and crystallization temperature, Tcc. As the Tg difference becoming narrow to $60^{\circ}C$, and Tcc decreasing to $150^{\circ}C$, the comparability of PC and PET was increased. And also tough rate impact strength to PC/PET alloy using MBS was increased, in case more than 15 parts of PC being blended to PET.

• Nuclear Medicine and Molecular Imaging
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• v.43 no.5
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• pp.369-385
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• 2009

In this paper, the authors intended to summarize briefly the features of lymphoma with regard to $^{18}F$-FDG PET for assessment of tumor response to therapy, to describe why assessment of treatment response should be performed, to review what method so far has been used in monitoring treatment response, to discuss what limitations of morphologic imaging criteria for assessing tumor response are, in compared with $^{18}F$-FDG PET, and to introduce recently proposed criteria for assessing tumor response in malignant lymphoma. And also the authors emphasize the need to understand the characteristics of diagnostic performance of $^{18}F$-FDG PET in several clinical settings in order to interpret $^{18}F$-FDG PET results appropriately, and to encourage the use of interval likelihood ratio to enhance clinical implications of test results which, in turns, allows referring physicians to understand the meaning of interpretation with easy. Until recently, treatment response has been assessed according to the morphologic criteria. Metabolic imaging with $^{18}F$-FDG PET was adopted to have important role for treatment assessment in IWC+PET criteria proposed recently by IHP. To accomplish this role, we should perform and interpret $^{18}F$-FDG PET according to IWC+PET criteria. It is important for referring physicians to understand the various limitations of $^{18}F$-FDG PET and pitfalls in PET interpretation, and to understand that clinical information are needed by nuclear medicine physicians to optimize the interpretation of $^{18}F$-FDG PET.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.913-916
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• 2008

Direct tensile response of strain hardening cement composites(SHCC) depends primarily on the material's tensile response, which is a water cement ratio, direct function of fiber and matrix characteristics, the bond between them, and the fiber volume fraction. This paper discusses effect of aspect ratio of the direct tensile response of SHCC with PET and PVA fibers. The main variables considered include the aspect ratio of PET fibers(Aspect ratio, ${\ell}/d_f$ : 150, 300, 600). For the same mixture proportion, PET1.5+PVA0.5-300 and PET1.5+PVA 0.5-600(Aspect ratio 300, 600) showed better overall behavior(Pseudo strain-hardening, Multiple cracking) than specimens with PET1.5+PVA0.5-150(Aspect ratio 150). Tensile strain of PET1.5+PVA0.5-300 and PET1.5+PVA 0.5-600 at ultimate tensile stress were 0.5, 2.0% respectively.

• Journal of the Korean Society of Clothing and Textiles
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• v.10 no.2
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• pp.79-84
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• 1986

Methacrylic acid was graft polymerized with benzoyl peroxide in itiator onto the commercial PET film. Graft polymerization was carried out in emulsion, which consisted of BPO (1), chlorobenzene(8) as swelling agent, tween 80(1) and sodium lauryl sulfate(1) as emulsifier and water(1,000). Original PET film has poor reactivities and, so the film preswdled with benzyl alcohol($150^{\circ}C$, 1hr) was also examined. The graft yield of PET film was increased with reaction temperature and monomer concentration. The graft yield of preswelled PET film was higher than that of no-treated PET film. Moisture regain was linearly increased with graft yield. DSC thermodiagram showed the Tm of grafted PET film was same as that of original PET film. Grafted PET film was dyed with methylene blue solution. The photograph of the cross section showed that grafting was occured not at the center but near surfaces.