• Polymer(Korea)
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• v.29 no.6
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• pp.557-564
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• 2005

Thermoplastic starch (TPS) was manufactured and blended with poly(butylene adipate-co-succinate) (PBAS), which is one of the most popular biodegradable aliphatic polyesters. The effects of the TPS contents on the mechanical properties, thermal characteristics, and biodegradability of PBAS/TPS blends were investigated. The foaming characteristics of those were also studied. With small amount of TPS, mechanical properties of the blends were largely deteriorated and the variations of them decreased with more addition of TPS. In addition, TPS decreased crystallinity and thermal decomposition temperature of PBAS. The PBAS/TPS foam having maximum blowing ratio was obtained with 20 Phr of TPS, and their blowing ratio decreased with the further increase of TPS.

• Journal of the Korean Electrochemical Society
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• v.22 no.1
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• pp.13-21
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• 2019

Prussian blue analogues(PBAs) are comprised of cyano-bridged transition metal ions. The wide and unique open-framework structures of the PBAs enable reversible intercalation and deintercalation of various ions such as $Na^+$, $K^+$, $Mg^{2+}$, $Zn^{2+}$, etc. In addition, since PBAs are synthesized through coprecipitation reaction in aqueous solution at room temperature, they are produced economically and environmentally friendly. However, the formation of crystals proceeds rapidly, and defects such as vacancy and crystal water tend to be present in the crystals, thereby affecting key battery performance. Therefore, significant efforts to inhibit defects in PBAs have been made. In the case of vacancy, the reaction rate was controlled at the synthesis stage to reduce the formation of vacancy, and the crystal water was removed by heat treatment under vacuum. In addition, by adding transition metals that do not react within the structure of PBA, the structural instability during the electrochemical reaction was largely alleviated.

• Applied Chemistry for Engineering
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• v.16 no.6
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• pp.800-808
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• 2005

The compounding resin for biodegradable wrap was developed, and its manufacturing process and physical properties were studied. For these purposes, following factors were optimized: the types and amounts of raw resin material, anti-oxidants, and lubricants used. In this work, the stable compounding resin used to make biodegradable wrap was based on poly(butylene adipate-co-butylenesuccinate) (PBAS) and poly(butyleneadipate-co-butylene succinate-co-butyleneterephthalate) (PBAST). The improved properties of resin with an additive were investigated by melting flow index (MFI). From these results, the physical properties of compounding resin, based on PBAST, were more than those of PBAS. For PBAS, the Irganox 1010, 1076 and Irgafos TNPP as the first and second anti-oxidants, respectively, were good. For PBAST, the good first and second anti-oxidants, respectively, were Irganox 1076 and Mark PEP 36. The good lubricants for feeding PBAS and PBAST were glycerol monostearate and palmityl alcohol, respectively. The stability and tensile strength experiment of wrap were also investigated by the elution of heavy metals and universal testing machine (UTM), respectively. The decomposition ratio of developed wrap was increased proportional to the reclaiming time. The degradation ratio of compounding resin sample was about 60% after 40 days.

• Bulletin of the Korean Chemical Society
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• v.31 no.5
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• pp.1336-1338
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• 2010

Three cobalt-iron Prussian Blue Analogues (PBAs) nanotubes contained with different alkali metal cations of K, Rb or Cs, respectively, were prepared by using cetyltrimethylammonium bromide (CTAB)/ethanol-water micelles as soft templates. The products were characterized by energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), transmission electron microscopy (TEM) and scanning electron micrograph (SEM), which confirmed the composition of the substances and their unique nanotube structures. Furthermore, the formation mechanism of the PBAs nanotubes was discussed and provided useful insight for further synthesis of nanotubes of other Prussian blue analogues.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.3
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• pp.55-64
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• 1996

In this paper, we analyze packaging data of th eprinted board assemblies (PBAs) of an ATM switching system (the first network test bed) by statistical methods and discuss the relation between devices packaging area of a PBA and power consumption by a regression nalysis method. As a result, we evaluate the maximum power consumption of the PBA. And, this paper presents a forecasting mehtod of the packagable maximum power consumption per a PBA when TTL devices are replaced by ASIC or FPGA ones in a PBA. And, we forecast the possibility of packaging ATM switch circuit packs in the near future form a statistical viewpoint. These evaluation and forecasting results can reduce much development cost and time because trial nd error will not be made using these useful data when phase II ATM switching system will be realized in the near future.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.8 no.2
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• pp.133-138
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• 2014

In this paper, a simple but efficient gait recognition method using spatial-temporal silhouette analysis is proposed. For each image sequence, a background subtraction algorithm and a PBAS(pixel based adaptive segmenter) procedure are first used to segment the moving silhouettes of a walking figure. Then, to identify people, the step count and stride length of walking figure is obtained in silhouette images. Experimental results on a CASIA dataset including 124 subjects demonstrate the validity of the proposed method. Also, the proposed system are believed to have a sufficient feasibility for the application to gait recognition.

• Elastomers and Composites
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• v.58 no.4
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• pp.208-215
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• 2023

In this study, the properties of polyurethane-polydimethylsiloxane (PU-PDMS) hybrid foams containing different types and contents of physical blowing agents (PBAs) were investigated. Two types of blowing agents, namely physical blowing agents and thermally expandable microspheres (TEM), were applied. The apparent density was measured using precisely cut foam samples, and the pore size was measured using image software. In addition, the microstructure of the foam was confirmed via scanning electron microscopy and transmission electron microscopy. The thermal conductivities related to the microstructures of the different foams were compared. When 0.5 phr of the hydrocarbon-based PBA was added, the apparent density and pore size of the foam were minimal; however, the pore size was larger than that of neat foam. In contrast, the addition of 3 phr of TEM effectively reduced both the apparent density and pore size of the PBAs. The increase in resin viscosity owing to TEM could enhance bubble production stability, leading to the formation of more uniform and smaller pores. These results indicate that TEM is a highly efficient PBA that can be employed to decrease the weight and pore size of PU-PDMS hybrid foams.

• Composites Research
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• v.32 no.6
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• pp.355-359
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• 2019

The high efficient water splitting system should involve the reduction of high overpotential value, which was enhanced by the electrocatalytic reaction efficiency of catalysts, during the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) reaction, respectively. Among them, transition metal-based compounds (oxides, sulfides, phosphides, and nitrides) are attracting attention as catalyst materials to replace noble metals that are currently commercially available. Herein, we synthesized optimal monodisperse Co₃[Co(CN)₆]₂ PBAs by FESEM, and confirmed crystallinity by XRD and FT-IR, and thermal behavior of PBAs via TG-DTA. Also, we synthesized monodispersed Co₃O₄ nanocubes by calcination of Co₃[Co(CN)₆]₂ PBAs, confirmed the crystallinity by XRD, and proceeded OER measurement. Finally, the synthesized Co₃O₄ nanocubes showed a low overpotential of 312 mV at a current density of 10 mA·cm^-2 with a low Tafel plot (96.6 mV·dec^-1).

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.27 no.3
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• pp.110-114
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• 2017

$NiO/NiCo_2O_4$ nanocubes were successfully synthesized via the calcination process of $Ni_3[Co(CN)_6]_2$ PBAs. The prepared monodispersed $Ni_3[Co(CN)_6]_2$ PBAs were aggregated by 'self-assembly' of the nuclei generated during the synthesis reaction. The self-assembly rate of the particles is affected by the temperature and the amount of surfactant SDBS (sodium dodecylbenzenesulfonate). FESEM analysis shows that monodispersed 200 nm PBA nanocubes are obtained at 0.25 g SDBS and $60^{\circ}C$ temperature. Thermal behavior was confirmed by thermogravimetric-differential thermal analysis (TG-DTA) to determine optimal calcination conditions. Then, field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD) analyzes were performed to investigate the morphology and crystallinity of the particles precursors and $NiO/NiCo_2O_4$ nanocubes.

• Journal of the Korea Society of Computer and Information
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• v.24 no.6
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• pp.67-72
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• 2019

This paper proposes a computer vision-based banknote recognition system intended to assist the blind. This system is robust and fast in recognizing banknotes on videos recorded with a smartphone on real-life scenarios. To reduce the computation time and enable a robust recognition in cluttered environments, this study segments the banknote candidate area from the background utilizing a technique called Pixel-Based Adaptive Segmenter (PBAS). The Speeded-Up Robust Features (SURF) interest point detector is used, and SURF feature vectors are computed only when sufficient interest points are found. The proposed algorithm achieves a recognition accuracy of 98%, a 100% true recognition rate and a 0% false recognition rate. Although Korean banknotes are used as a working example, the proposed system can be applied to recognize other countries' banknotes.