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Fresh-cut apples are commonly known as minimally processed agricultural products because of their convenience and ease of consumption. However, during storage, the quality of the apple rapidly changes after cutting due to enzymatic and non-enzymatic processes. This study aimed to monitor the quality changes and volatile compounds in fresh-cut apples at various temperatures using an electronic nose. The quality relationships of the product during distribution and storage using cold chain systems were also evaluated. The results showed that the total viable count initially differed between fresh-cut apples (2.59 Log CFU/g) and mixed fruits (apple ‘Hongro’, kumquat, and cherry tomatoes) (3.2 Log CFU/g) during the storage period (p < 0.05). There were no significant differences (p > 0.05) in the physicochemical properties except for the firmness, color values, browning index, whiteness index, and titratable acidity. The volatile compounds found in fresh-cut apples indicating apple fruit aroma were propyl propanoate and ethyl isovalerate, hexanol (freshness), and methanethiol and ethyl acetate (unpleasant off-odor), and these compounds could be used as markers for the deterioration process in fresh-cut apples during storage. Methanethiol and ethyl acetate were correlated with microbial growth (Pearson correlation of 0.81–0.98 for total viable microbe and 0.49–0.90 for coliform count). The limonene level was higher in the mixed fruits than in other treatments and gradually increased during storage due to the kumquat.

Brown rice (BR) is unpolished rice containing many bioactive compounds in addition to the basic nutrients of the rice grain. Herein, BR was germinated for up to 48 h to prepare germinated brown rice (GBR). The physiological and chemical changes in the GBR during germination were analyzed. GBR samples germinated for 48 h were in the radicle-emergence stage, but root formation was not observed. The change in the GBR metabolite profile during germination was analyzed to determine the effect of germination on the chemical profiles of the GBR samples. Twenty-five metabolites including acidic compounds, amino acids, sugars, lipid metabolites, and secondary metabolites were identified as the components that contributed to the variations in the GBR groups germinated for different time periods. Among the metabolites, the carbohydrates associated with energy production and lipid metabolites changed significantly. Based on the identified metabolites, a metabolomic pathway was proposed. Carbohydrate metabolism, citric acid cycle, and lipid metabolism were the main processes that were affected during germination. Although further studies on the relationship between the metabolite profile and nutritional quality of the GBR are needed, these results are useful for understanding the effect of germination on the physiological and chemical changes in BR.

Various studies have been conducted to minimize the damage and loss of stored grain. For safe storage, the moisture content must be reduced, or respiration must be suppressed. In this study, grain respiration rates were analyzed under various nitrogen atmospheric conditions, and the quality of stored rice was evaluated. As the nitrogen content of the storage space increases, the respiration rate of the grain decreases accordingly. In this study, the effect of the modified atmospheric nitrogen concentration on reducing respiration was determined. When predicting weight loss due to respiration, low moisture content, and high nitrogen concentration could reduce loss. Quality analysis was performed to compare different respiration rate conditions and showed that lower oxygen concentration and moisture content were associated with safer storage. Our results indicate that changes in atmospheric conditions depending on climate and storage conditions can be considered for the safe storage of harvested rice.

Cultivated lands within the river district are likely non-point sources of pollution that could be directly discharged into rivers and lakes, as well as identified as significantly risky areas for pollutant run-off during floods. In this study, major non-point sources in surface runoffs, from cultivated lands within the river districts, and their effects on the bodies of water in North Han River Basin were examined. It was found that pollutant concentrations in the run-offs from farms appeared to be generally higher than in the run-offs from paddies. Initial concentrations of pollutants during rainy seasons were usually higher than the medians of their concentration ranges, though not necessarily the highest. The unit loads of BOD from cultivated lands within river districts, which were proposed in this study for the first time in Korea, were 4.56, 3.35, and 10.26 kg/km²/year for paddies, farms, and greenhouses, respectively. Likewise the unit loads of total nitrogen (TN) were proposed as 1.54, 8.11, and 5.59 kg/km²/year for paddies, farms, and greenhouse, respectively. Meanwhile, the unit loads of Total phosphorus (TP) were 0.71, 2.79, and 1.11 kg/km²/year for paddies, farms, and greenhouses, respectively. The unit loads for both BOD and TP from paddies and farms in the North Han River basin were higher than those provided by the Ministry of Environment. It was largely attributable to the regional characteristics of the cultivated area, within the river district, that is adjacent to the water system. Three priority standard watersheds, which were believed to contain higher non-point sources of pollution than other standard watersheds, were recommended to undergo restoration. The sum of the discharged total loads per unit area for BOD, TN, and TP from these three standard watersheds (i.e. NHR M2, NHR1, and NHR M) was 71.8, 71.5, and 73.0%, respectively. Restoring cultivated lands within river districts into grasslands could effectively reduce the total load of TP rather than BOD and TN. Therefore, converting cultivated lands within river districts back to grasslands can be an alternative in effectively reducing pollution in bodies of water. [ABSTRACT FROM AUTHOR]

Carbon supported platinum nanoparticles were synthesized by reducing H2PtCI6 precursor dissolved in water containing carbon powders by a plasma-chemical method. The fast reduction of the precursor was achieved with the help of active hydrogen species generated in the plasma zone contacting the surface of the aqueous solution. The size of the Pt particles supported on the carbon was in the range of 3 to 5 nm with the solution temperature set at 5°C. The performance of the proton exchange membrane fuel cell employing as-prepared Pt/C as the electrocatalyst was comparable to that using commercial Pt/C catalyst. [ABSTRACT FROM AUTHOR]

The effect of copper addition on powder processed Al-10 vol% SiC composites was studied in regards to their sintering responses. Copper was mixed with aluminum powder either as elemental powders or as the coated layer on SiC particles. After sintering at 600°C for 1 h, Al-SiC composites with no copper addition showed little densification. It also demonstrated very low bend strengths of 49 and 60 MPa, indicating poor bonding between the powders in the sintered composite. The addition of 8% copper to the Al/SiC system effectively improved the sintering response, producing over 95% theoretical density, a bend strength of 231 MPa with the copper coated SiC, and a 90% density with over 200 MPa bend strength with the admixed copper.The as-sintered microstructures of the Al-SiC composites clearly revealed particle boundaries and sharp pores, indicating that only a limited neck growth occurred during sintering. In the case of Al-Cu-SiC composites, however, a liquid phase was formed and spread through particle boundaries filling the interfaces or voids between SiC particles and the matrix powders. The coated copper on SiC particles produced a somewhat better filling of the interface or voids, resulting in a little more densification and better sintered strength. Since the solubility of copper in aluminum is less than 2% at the sintering temperature, the alloying of copper in the aluminum matrix was limited. Most of the copper added was dissolved in the liquid phase during the sintering and precipitated as CuAl2 phase upon cooling. [ABSTRACT FROM AUTHOR]

The ultrafine titanium carbonitride particles (TiC0.5N0.5) with 100 nm in mean size was successfully synthesized by nitridation treatment at ordinary temperatures, 1373∼1473 K of the nanostructured half-stoichiometric titanium carbide (TiC0.5) particles, which were produced by the magnesium reduction of gaseous TiCl4+1/4C2Cl4. In addition, the nitrogen stability for the produced titanium carbonitride particles at various temperatures and vacuum conditions was investigated experimentally and compared with values calculated by an ideal solution model. [ABSTRACT FROM AUTHOR]

The objective of this study is to investigate the performance characteristics of a small-sized R600a household refrigeration system that adopts a condenser outlet split (COS) ejector cycle under various operating and ejector geometry conditions. The coefficient of performance and pressure lifting ratio of the COS ejector cycle were analyzed and measured by varying the entrainment ratio, compressor speed, and nozzle exit position. The optimum nozzle exit position in the COS ejector cycle adopted to achieve the maximum cycle performance was proposed as a function of the compressor speed and entrainment ratio. The optimum nozzle exit position was 0 mm when the entrainment ratio and compressor speed were low, and it increased as the entrainment ratio and compressor speed increased owing to the associated internal pressure drop in the suction section.