• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.352.2-352.2
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• 2014

In this present work, we report a Cu-Mn alloy as a materials for the self-forming barrier process. And we investigated diffusion barrier properties of self-formed layer on low-k dielectrics with or without UV curing treatment. Cu alloy films were directly deposited onto low-k dielectrics by co-sputtering, followed by annealing at various temperatures. X-ray diffraction revealed Cu (111), Cu (200) and Cu (220) peaks for both of Cu alloys. The self-formed layers were investigated by transmission electron microscopy. In order to compare barrier properties between Mn-based interlayer interlayer, thermal stability was measured with various low-k dielectrics. X-ray photoelectron spectroscopy analysis showed that chemical compositions of self-formed layer. The compositions of the Mn based self-formed barriers after annealing were determined by the C concentration in the dielectric layers.

• Journal of the Korean Ceramic Society
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• v.43 no.8 s.291
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• pp.498-503
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• 2006

A gas turbine blade with thermal barrier ceramic coating is operated at high temperature to increase engine efficiency. Recently, thermal barrier characteristics have been improved by advanced coating technology through microstructure control and increase of adhesion force of the coating layer. More advanced coating materials, rare earth zircon ate ceramics have been studied for replacing YSZ coatings as thermal barrier coatings. In this study, $La_2O_3,\;HfO_2,\;CeO_2,\;Gd_2O_3$ and pure or yttria stabilized zirconia were prepared. Microstructure analysis and the evaluation of mechanical properties such as Hertzian indentation and hardness test were performed.

• JSTS:Journal of Semiconductor Technology and Science
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• v.3 no.1
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• pp.1-12
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• 2003

This paper describes a study on the abnormal behavior of the electrical characteristics of the (n)GaAs/Ti/Pt/Au Schottky contacts prepared by the two techniques of electron beam deposition and rf sputtering and after an annealing treatment. The samples were characterized by I-V and C-V measurements carried out over the temperature range of 150 - 350 K both in the as prepared state and after a 300 C, 30 min. anneal step. The variation of ideality factor with forward bias, the variation of ideality factor and barrier height with temperature and the difference between the capacitance barrier and current barrier show the presence of a thin interfacial oxide layer along with barrier height inhomogenieties at the metal/semiconductor interface. This barrier height inhomogeneity model also explains the lower barrier height for the sputtered samples to be due to the presence of low barrier height patches produced because of high plasma energy. After the annealing step the contacts prepared by electron beam have the highest typical current barrier height of 0.85 eV and capacitance barrier height of 0.86 eV whereas those prepared by sputtering (at the highest power studied) have the lowest typical current barrier height of 0.67 eV and capacitance barrier height of 0.78 eV.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.27 no.1
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• pp.17-23
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• 2021

Recent studies on recyclable materials in the packaging have an increased attention due to the eco-friendly policies of reducing carbon dioxide emissions in worldwide. Roasted coffee beans mostly packed in multi-layered films and papers according to their expiration date. To satisfy both recyclability and barrier properties, researches have been continued on paper-based packaging materials to enhance their properties. In this study, packaging materials for coffee beans are developed by laminating bioplastic films on papers. The tests of packaging materials were performed with mechanical properties, gas and water vaper permeability, recyclability and storage quality for coffee beans. Compared to other samples, the paper/bioplastics-based coffee package composed of starch coated papers and two bioplastics showed the lowest barrier properties, comparable mechanical strength and ability to maintain the quality of roasted coffee beans. Thus, it could be a good alternative for multi-layered packages for roasted coffee beans.

• Proceedings of the Korean Magnestics Society Conference
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• 2003.12a
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• pp.93-93
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• 2003

• Proceedings of KHEA Conference
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• 1997.07a
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• pp.258-258
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• 1997

• Proceedings of the Korean Magnestics Society Conference
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• 2005.06a
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• pp.100-101
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• 2005

• Food Science and Biotechnology
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• v.15 no.1
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• pp.133-137
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• 2006

Wheat gluten-chitosan composite film (WGCCF) can prevent moisture migration and enhance the antimicrobial properties of gluten in intermediate-moisture foods like sandwiches. To mimic the structure of actual sandwich-type products we developed multi-layer food models, where moisture content and water activity differ. Water activity gradients direct moisture migration and therefore determine product characteristics and product stability. A 10% wheat gluten film-forming solution was mixed with chitosan film-forming solution (0-3%, w/w) and evaporated to generate WGCCF. Addition of 3% chitosan enhanced the mechanical properties of the film composite, lowered its water vapor permeability, and improved its ability to protect against both, Streptococcus faecalis and Escherichia coli, in a 24 hr sandwich test (reduction of 1.3 and 2.7 log cycles, respectively, compared to controls). Best barrier and antimicrobial performance was found for 3% chitosan WGCCF at pH 5.1. Film of this type may find application as barrier film for intermediate-moisture foods.

• Food Science and Biotechnology
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• v.16 no.1
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• pp.62-66
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• 2007

Four different biopolyester films, two aliphatic polyesters including polylactides (PLA) and poly(3-hydroxy-butyrate-co-3-hydroxyvalerate (PHBV), and two aliphatic-aromatic copolyesters including Ecoplex and Biomax, were prepared using by thermo-compression, and their tensile and water barrier properties were determined. Among the films tested, PLA film was the most transparent (T: 95.8%), strongest, and stiffest (TS, 40.98 MPa; E, 1916 MPa), however it was rather brittle. In contrast, Ecoplex film was translucent while being the most flexible and resilient (EB, 766.8%). Biomax film was semitransparent and was the most brittle film tested (EB, 0.03%). All biopolyester films were water resistant exhibiting very low water solubility (WS) values ranging from 0.0.3 to 0.36%. PHBV film showed the lowest water vapor permeability (WVP) value ($1.26{\times}10^{-11}\;g{\cdot}m/m^2{\cdot}sec{\cdot}Pa$) followed by Biomax, PLA, and Ecoflex films, respectively. The water vapor barrier properties of each film were approximately 100 times higher than those of carbohydrate or protein-based films, but about 100 times lower than those of commodity polyolefin films such as low-density polyethylene (LDPE) or polypropylene (PP).

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2001.11b
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• pp.659-664
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• 2001

Noise barriers are widely used to reduce the sound level propagating from highways, railways or factories to residential areas. The reduced noise level at a receiver point is then determined by the diffracted waves around the edge of the barrier as well as by the transmitted waves through the barrier. For proper usage, many studies either theoretical or experimental have been made with the objective of precisely predicting the acoustic field and improving the noise attenuating properties of barriers. In this study, a simple scattering model, a line acoustic source scattered by an infinite cylinder, is introduced to simply investigate the sound attenuation efficiency of a sound-resonating barrier. From this model study, it is observed that the sound-resonating barrier can be used as a good sound-shielding element especially for the pure-tone noise generated from the transformer. Large sound-attenuation is achieved by applying the sound-resonating barrier to the large transformers in a substation.