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Nanocomposites of blends of poly(vinylidene fluoride) (PVDF) and poly(methyl methacrylate) (PMMA) with multiwalled carbon nanotubes (CNTs) were prepared by melt mixing and hot press molding followed by quenching or annealing (120 C, 24 h). PMMA-rich nanocomposites showed higher electrical conductivity than PVDF-rich samples at identical CNT loading. At a specific composition, the quenched nanocomposites showed electrical conductivity values three to four orders of magnitude higher than those observed in annealed samples. Measurement of the dielectric constants also supported the electrical conductivity results. In the annealed samples, agglomerated CNTs located mainly in the PVDF crystalline phase were observed. Addition of CNTs promoted the crystallization, and especially, the formation of b-crystals, which was confirmed by X-ray diffraction. The thermal behavior of nanocomposites from differential scanning calorimetry (DSC) analysis was explained in terms of the three-phase model involving the presence of the rigid amorphous fraction, the mobile amorphous fraction, and the crystalline phase. POLYM. COMPOS., 36:1195-1204

This study investigates the improvement of the CO 2 sequestration percentage of a ground granulated blast furnace slag (GGBF-slag) with surface modification using a NaOH solution. The amount of CO 2 sequestration of the GGBF slag increased via the surface modification with the NaOH solution in the direct carbonation method. The increase of the carbonation percentage of the GGBF slag resulted from the increase in the hydraulic activity of the GGBF-slag. The carbonation percentage on the basis of the total calcium oxide of the GGBF slag was approximately 10 times larger than that of the GGBF-slag without the surface-modification. The carbonation rate depended on the morphology of the calcium carbonates formed on the surface of the GGBF-slag.

In this research, in order to develop technology/country-specific emission factors of methane (CH4) and nitrous oxide (N2O), a total of 585 samples from eight gas-fired turbine combined cycle (GTCC) power plants were measured and analyzed. The research found that the emission factor for CH4 stood at “0.82 kg/TJ”, which was an 18 % lower than the emission factor for liquefied natural gas (LNG) GTCC “1 kg/TJ” presented by Intergovernmental Panel on Climate Change (IPCC). The result was 8 % up when compared with the emission factor of Japan which stands at “0.75 kg/TJ”. The emission factor for N2O was “0.65 kg/TJ”, which is significantly lower than “3 kg/TJ” of the emission factor for LNG GTCC presented by IPCC, but over six times higher than the default N2O emission factor of LNG. The evaluation of uncertainty was conducted based on the estimated non-CO2 emission factors, and the ranges of uncertainty for CH4 and N2O were between −12.96 and +13.89 %, and −11.43 and +12.86 %, respectively, which is significantly lower than uncertainties presented by IPCC. These differences proved that non-CO2 emissions can change depending on combustion technologies; therefore, it is vital to establish country/technology-specific emission factors.

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In this study, volatile compounds of various beans (black bean, mung bean, and soybean) were analyzed on the basis of particle sizes and extraction temperatures by two extraction methods, namely, distillation under reduced pressure–continuous liquid–liquid extraction (DRP–LLE) and hot water extraction (HWE). The experimental results confirmed the presence of 10 volatile components. The five major volatile compounds were hexanal, 2-methyl-1-butanol, 1-hexanol, 1-octen-3-ol and benzaldehyde. The highest total volatile compound concentrations in the extracts of black bean, mung bean, and soybean using DRP–LLE were obtained at 60 °C and 355–500 μm, 60 °C and 500–710 μm, and 50 °C and 355–500 μm, respectively. For the same particle size, the total volatile compound concentrations in the extracts of black bean, mung bean, and soybean obtained by HWE at 70 °C were 2–3 times significantly higher than those obtained at 90 °C. Moreover, the highest total volatile compound concentration was obtained in the black bean extract by HWE at 500–710 μm, while the lowest total volatile compound concentration in the soybean extract was obtained by HWE at 500–710 μm. The total concentrations of volatiles in the black bean and soybean extracts obtained by DRP–LLE were significantly higher than those obtained by HWE.

A process to produce pure calcite-type calcium carbonate by the carbonation of air-cooled blast furnace slag (BFS), which is a waste material and which has been utilized in limited applications, is reported here. The process is composed of two reactions. First, calcium ions are extracted from an air-cooled BFS slurry under pressurized gaseous CO 2 (1 to 5 MPa) at 273 K, at which the extracted calcium ions and calcium carbonate formed during the extraction process are dissolved in the solution due to the high solubility of the calcium carbonate under the high pressure of CO 2 . The second reaction is the precipitation of pure calcite-type calcium carbonate at atmospheric pressure at the same temperature after the removal of the solid residue remaining after the extraction process. Gaseous CO 2 was fed at atmospheric pressure to increase the precipitation ratio of calcium carbonate by the carbonation of the unreacted calcium ions in the solution. In this study, the influences of the following parameters on the extraction of calcium ions at 293 K were investigated experimentally: the initial weight ratio of air-cooled BFS to water, the CO 2 pressure, and the extraction time. According to our results, the extraction of calcium ions is not proportionally improved by increasing the aforementioned experimental parameters.

Korea-specific GHG emissions should be estimated correctly in order to ensure effective measurement of climate change variables. The use of country-specific data that reflects fuel and technology characteristics is needed for accurate GHG emissions estimation. Oxidation factors are used to convert existing data into equivalent GHG emissions, and changes in these oxidation factors are directly related to changes in emissions. As such, the oxidation factor is one of the most important variables in using country-specific data to determine GHG emissions. In this study, the oxidation factor of bituminous coal in large scale boilers was estimated using 4,527 data points sampled from eight large-scale boilers that had been using bituminous coal for two years. The average oxidation factor was determined to be 0.997, which is lower than the oxidation factor of 1 that is recommended by the IPCC G/L for large scale boilers when estimating national GHG emissions. However, an oxidation factor less than 1 is assumed for fluidized bed boilers, internal combustion engines, and other small-scale boilers. Accordingly, studies on oxidation factor estimation should be continued to allow for accurate estimation of GHG emissions.