• Advances in aircraft and spacecraft science
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• v.3 no.2
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• pp.171-195
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• 2016

The present paper is a review of the main activities carried out within the context of the COMPTINN' program, a joint research project founded by a FUI program (Fonds $Unifi{\acute{e}}s$ $Interminist{\acute{e}}riels$) in which four research teams focused on the thermo-oxidation behaviour of HTS-TACTIX carbon-epoxy composite at 'high' temperatures ($120^{\circ}C-180^{\circ}C$). The scientific aim of the COMPTINN' program was to better identify, with a multi-scale approach, the link between the physico-chemical mechanisms involved in thermo-oxidation phenomena, and to provide theoretical and numerical tools for predicting the mechanical behaviour of aged composite materials including damage onset and development.

• Tribology and Lubricants
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• v.11 no.5
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• pp.1-9
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• 1995

The mechanism of various spherical particles formation from wide range of tribo-systerns is suggested and deduced by the action of micro-explosion on the basis of the thermally-activated wear theory, in which the flash temperature at contact could be reached clearly upto the material molten temperature due to the secondary activation energy from the exothermic reactions involving lubricant thermo-decomposition, metals oxidation, hydrogen reactions and other possible complex thermo-reactions at the contacts. Various shapes of spherical particles generated from the tribosystem can be explained by the toroidal action of micro-explosion accompanied with the complex thermo-chemical reactions at the contact surfaces or sub-surfaces.

• Korean Chemical Engineering Research
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• v.49 no.2
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• pp.161-167
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• 2011

Recent popularity in mobile electronics requires higher standard on the mechanical strength of electronic packaging. Thus, the method of soldering between chip and substrate in electronic packaging process is changing from conventional method using intermetallic compound to a new method using organic solderability preservatives (OSP) in order to improve the stability and the reliability of final product. Since current OSPs have several serious problems like thermo-stability during packaging process, however, it is necessary to develop new OSPs having thermo-stability. The main purpose of this study is to develop various thermo-stable OSPs based upon poly(vinyl pyridine-co- methylmethacrylate) and to evaluate their anti-oxidation property protecting Cu pad, thermo-stability and solubility to acid- or alcohol-containing aqueous solution during pos-fluxing. All OSPs showed not only good anti-oxidation property, thermo-stability and solubility but also more advantages like low cost, less odor, and less hygroscopic.

• Carbon letters
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• v.25
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• pp.60-67
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• 2018

In the present work, capability of thymolphthalein-grafted graphene oxide, which was successfully synthesized in this study, in stabilization of polypropylene against thermal oxidation were investigated and compared with that of SONGNOX 1010, a commercially used phenolic antioxidant for the polymer. The modified graphene oxide were incorporated into polypropylene via melt mixing. State of distribution of the nanoplatelets in the polymer matrix was examined using scanning electron microscopy and was shown to be homogeneous. Measurements of oxidation onset temperature and oxidative induction time revealed that thymolphthalein-grafted graphene oxide modifies thermo-oxidative stability of the polymer in the melt state remarkably. However, the efficiency of the nanoplatelets in stabilization of polypropylene against thermal oxidation in melt state was shown to be inferior to that of SONGNOX 1010. Furthermore, oven ageing experiments followed by Fourier transform infrared spectroscopy showed that the modified graphene oxide improves thermo-oxidative stability of the polymer strongly in the solid state, so that its stabilization efficiency is comparable to that of SONGNOX 1010.

• Journal of Powder Materials
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• v.11 no.2
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• pp.111-117
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• 2004

The oxidation behavior of 91 WC-9Co hardmetal in weight percentage has been studied in the present work as a part of the development of recycling process. The morphological and compositional changes of the WC-Co hardmetal with oxidation time at 90$0^{\circ}C$ were analyzed by using surface observation and X-ray diffraction. respective]y. As the oxidation time increased, the WC-Co hardmetal was continuously expanded to form porous oxide mixtures of $CoWO_4$ and $WO_3$. The morphology of porous oxide mixture was basically dependent on initial shape of the WC-Co hardmetal. From thermo-gravimetric (TG) analysis, it was found that the oxidation rate was increased with increasing oxidation temperature and oxygen content in the flowing atmospheric gas. The fraction of oxidation versus time curves showed S-curve relationship at a given of oxidation temperature. These oxidation behaviors of the WC-Co hardmetal were discussed in terms of previously proposed kinetic models.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.11a
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• pp.84-85
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• 2005

Dislocations are often found at Shallow Trench Isolation (STI) process after repeated thermal cycles. The residual stress after STI process often leads defect like dislocation by post STI thermo-mechanical stress. Thermo-mechanical stress induced by STI process is difficult to remove perfectly by plastic deformation at previous thermal cycles. Embedded flash memory process is very weak in terms of post STI thermo-mechanical stress, because it requires more oxidation steps than other devices. Therefore, dislocation-free flash process should be optimized.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2004.06a
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• pp.105-114
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• 2004

This study investigated the thermal behavior of the nuclear graphite waste generated from the decommissioning of the Korean nuclear research reactor, The first part study investigated the decomposition rate of the nuclear graphite waste up to $1000^{\circ}C$ under various oxygen partial pressures using a thermo-gravimetric analyzer (TGA). Tested graphite waste sample not easily destroyed in the oxygen-deficient condition. However, the gas-solid oxidation reaction was found to be very effective in the presence of oxygen. No significant amount of the product of incomplete combustion was formed even in the limited oxygen concentration of 4% $O_2$. The influence of temperature and oxygen partial pressure was evaluated by the theoretical model analysis of the thermo-gravimetric data. The activation energy and the reaction order of graphite oxidation were evaluated as 128 kJ/mole and 1.1, respectively. The second part of this study investigated the behavior of radioactive elements under graphite oxidation atmosphere using thermodynamic equilibrium model. $^{22}Na$, $^{134}Cs$ and $^{137}Cs$ were found be the semi-volatile elements. Since volatile uranium species can be formulated at high temperatures above $1050^{\circ}C$, the temperature of incinerator furnace should be minimized. Other corrosion/activation products, fission products and uranium were found to be the non-volatile species.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.4
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• pp.759-764
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• 2012

Copper Pillar Tin Bump (CPTB) was investigated for high density chip interconnect technology development, which was prepared by electroplating and electro-less plating methods. Copper pillar tin bumps that have $100{\mu}m$ pitch were introduced with fabrication process using a KM-1250 dry film photoresist (DFR), with copper electroplating for Copper Pillar Bump (CPB) formation firstly, and then tin electro-less plating on it for control oxidation. Electric resistivity and mechanical shear strength measurements were introduced to characterize the oxidation effects and bonding process as a function of thermo-compression. Electrical resistivity increased with increasing oxidation thickness, and shear strength had maximum value with $330^{\circ}C$ and 500 N at thermo-compression process. Through the simulation work, it was proved that the CPTB decreased in its size of conduction area as time passes, however it was largely affected by the copper oxidation.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.726-729
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• 2010

Copper Pillar Tin Bump (CPTB) was investigated for high density chip interconnect technology development, which was prepared by electroplating and electro-less plating methods. Copper pillar tin bumps that have $100{\mu}m$ pitch were introduced with fabrication process using a KM-1250 dry film photoresist (DFR), with copper electroplating for Copper Pillar Bump (CPB) formation firstly, and then tin electro-less plating on it for control oxidation. Electric resistivity and mechanical shear strength measurements were introduced to characterize the oxidation effects and bonding process as a function of thermo-compression. Electrical resistivity increased with increasing oxidation thickness, and shear strength had maximum value with $330^{\circ}C$ and 500 N thermo-compression process. Through the simulation work, it was proved that when the CPTB decreased in its size, it was largely affected by the copper oxidation.

• Food Science and Biotechnology
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• v.16 no.6
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• pp.981-987
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• 2007

Effects of lignan compounds (sesamol, sesamin, and sesamolin) extracted from roasted sesame oil on the autoxidation at $60^{\circ}C$ for 7 days and thermal oxidation at $180^{\circ}C$ for 10 hr of sunflower oil were studied by determining conjugated dienoic acid (CDA) contents, p-anisidine values (PAV), and fatty acid composition. Contents of lignan compounds during the oxidations were also monitored. ${\alpha}$-Tocopherol was used as a reference antioxidant. Addition of lignan compounds decreased CDA contents and PAY of the oils during oxidation at $60^{\circ}C$ or heating at $180^{\circ}C$, which indicated that sesame oil lignans lowered the autoxidation and thermal oxidation of sunflower oil. Sesamol was the most effective in decreasing CDA formation and hydroperoxide decomposition in the auto- and thermo-oxidation of oil, and its antioxidant activity was significantly higher than that of ${\alpha}$-tocopherol. Sesamol, sesamin, and sesamolin added to sunflower oil were degraded during the oxidations of oils, with the fastest degradation of sesamol. Degradation of sesamin and sesamolin during the oxidations of the oil were lower than that of ${\alpha}$-tocopherol. The results strongly indicate that the oxidative stability of sunflower oil can be improved by the addition of sesamol, sesamin, or sesamolin extracted from roasted sesame oil.