Effect of a diffuser on gas-solid behavior in CFB riser for CO2 capture

Gas-solid fluidized beds have been used in CO₂ capture processes because of their high mixing characteristic and heat and mass transfer. Sufficient residence time of solid particles in a reactor is required to capture CO₂. However, a fraction of solid particles pass through a reactor without capturing CO₂ due to normal reaction characteristics. Therefore, the objective of the present study was to increase the sorbent residence time using a diffuser in a reactor for CO₂ capture. An Eulerian-Eulerian model in a commercial CFD program was employed to simulate gas-solid flow in the reactor. First, sensitivity analysis depending on operating conditions was conducted to predict the residence time of solid particles. The diffuser was located in the middle of the reactor and the angle of the diffuser was changed. Solid particles dispersed in the radial direction because of gas characteristics in the diffuser and increased the residence time. The results showed that the diffuser increased the sorbent residence time, so that the probabilities of gas-solid reaction would be also improved.

     

A Generalized Crystallographic Description of All Tellurium Nanostructures

Despite tellurium being less abundant in the Earth's crust than gold, platinum, or rare‐earth elements, the number of industrial applications of tellurium has rapidly increased in recent years. However, to date, many properties of tellurium and its associated compounds remain unknown. For example, formation mechanisms of many tellurium nanostructures synthesized so far have not yet been verified, and it is unclear why tellurium can readily transform to other compounds like silver telluride by simply mixing with solutions containing silver ions. This uncertainty appears to be due to previous misunderstandings about the tellurium structure. Here, a new approach to the tellurium structure via synthesized structures is proposed. It is found that the proposed approach applies not only to these structures but to all other tellurium nanostructures. Moreover, some unique tellurium nanostructures whose formation mechanism are, until now, unconfirmed can be explained.     

Using Numerical Analysis to Develop and Evaluate the Method of High Temperature Sous‐Vide to Soften Carrot Texture in Different‐Sized Packages

The high‐temperature sous‐vide (HTSV) method was developed to prepare carrots with a soft texture at the appropriate degree of pasteurization. The effect of heating conditions, such as temperature and time, was investigated on various package sizes. Heating temperatures of 70, 80, and 90 °C and heating times of 10 and 20 min were used to evaluate the HTSV method. A 3‐dimensional conduction model and numerical simulations were used to estimate the temperature distribution and the rate of heat transfer to samples with various geometries. Four different‐sized packages were prepared by stacking carrot sticks of identical size (9.6 × 9.6 × 90 mm) in a row. The sizes of the packages used were as follows: (1) 9.6 × 86.4 × 90, (2) 19.2 × 163.2 × 90, (3) 28.8 × 86.4 × 90, and (4) 38.4 × 86.4 × 90 mm. Although only a moderate change in color (L*, a*, and b*) was observed following HTSV cooking, there was a significant decrease in carrot hardness. The geometry of the package and the heating conditions significantly influenced the degree of pasteurization and the final texture of the carrots. Numerical simulations successfully described the effect of geometry on samples at different heating conditions.     

Political disagreement and ambivalence in new information environment: Exploring conditional indirect effects of partisan news use and heterogeneous discussion networks on SNSs on political participation

This study investigates the (de)mobilizing influences of political (dis)agreement in the news and in political discussion on political attitudes and participation in new information environments. Results demonstrate the mediating functions of political ambivalence in that exposure to proattitudinal news reduces ambivalence and thereby promotes political participation, whereas exposure to counter-attitudinal news increases ambivalence and thereby discourages participation. Importantly, the effect of exposure to counter-attitudinal news on ambivalence was moderated by heterogeneous discussion networks on social network sites, such that the combination of exposure to counter-attitudinal news and to heterogeneous discussion networks amplifies ambivalence additively, and thereby augments the tendency toward demobilization. These results are interpreted as suggesting that changing media contexts may lead to complex roles of news and political discussion.     

Android application that provides information on the foot and mouth disease in Korea

The foot and mouth disease is one of the most infectious diseases among artiodactyla. This occurred in and caused great damage to Korea in 2010. The effect was spread all over the country since it was not dealt with effectively at the early stages of the outbreak. Thus, this study aims to develop an application with the menu items such as the outbreak areas, and symptoms, and prompt reports of the foot and mouth disease so that stock farmers can download it through Smartphone and tablet PC web markets. The developed application enables stock farmers to get realtime information on the foot and mouth disease anywhere anytime, and to cope with this disease promptly when it occurs around their farming areas. It is expected that this application will be of help in preventing the foot and mouth disease from spreading further.     

Antioxidant activities and nutritional properties of Jeonyak prepared with beef bone stock and gelatin

The antioxidant activities and nutritional properties of Jeonyak made with beef bone stock and gelatin were investigated. Traditional Jeonyak (J1) was prepared with beef bone stock, whereas modified Jeonyak was made with gelatin and honey (J2) or with gelatin and oligosaccharides (J3). All 3 kinds of Jeonyak had antioxidant activities and J1 had the highest activity. The α-glucosidase inhibitory activity was measured to investigate the antidiabetic effect and J3 had the highest inhibitory activity of 80.47%. Glycine was the most abundant amino acid in all 3 kinds of Jeonyak. Both traditional and modified Jeonyaks have antioxidative and antidiabetic effects, suggesting that Jeonyak can be used as an effective traditional functional food.     

An experimental study of acoustically driven medium-scale pool fires

A set of experiments has been conducted on a medium-scale propane fueled pool fire acoustically forced in order to facilitate repeatable measurements defining the flame’s transient behavior. The fuel flow was slightly perturbed at the pool fire’s natural frequency by a sine waveform driven with a loudspeaker which was installed under the burner. As a result of the perturbation, the puffing behavior of the pool fire and the fire shape were modified. As the magnitude of the sine wave was increased larger perturbations were clearly observed, based on the measurement of the radiative heat flux and image analysis. Temperature and soot volume fractions were measured along the center line and throughout a slice of the flame. The soot volume fractions in the flame region are in good agreement with the data of other researchers. The reproducibility of these measurements was established through several experiments. The acoustically driven flame provides the possibility of more repeatable measurements of the transient behavior of these pool fires.