The micro-reactor testing of catalysts and fuel delivery apparatuses for diesel autothermal reforming

This study investigated two factors affecting the performance of diesel autothermal reforming (ATR): the reforming activity of selected catalysts and the effect of devised fuel delivery apparatuses. When fluorite and perovskite-structured ceramic materials were used as substrates, H₂ yields were higher than when an inert Al₂O₃ substrate was used at 700–800 °C. Gadolinium (Gd)-doped CeO₂ (CGO) had the highest H₂ production rate in the selected substrates. Platinum (Pt) showed better performance than rhodium (Rh) and ruthenium (Ru) when CGO was used as the substrate. Although the nickel (Ni)-added Pt catalyst (Pt–Ni) showed high H₂ yield, carbon deposition over this catalyst was more severe than with Pt. Oxygen ion (O²⁻) vacancies generated by Gd dopants can enhance the reforming activity of CeO₂. When using a microchannel catalyst bed, the performance degradation at high gas flowrates can be compared to a packed catalyst bed of pellet type. For effective fuel delivery, we have introduced an ultrasonic injector (UI) and a plasma injector (PI). The UI-reforming showed greater long-term stability than non-UI reforming because the generation of carbon precursors was suppressed. On the other hand, the PI-reformer had low conversion efficiency, although it had high H₂ selectivity.     

Reliability-based robust design optimization for torque ripple reduction considering manufacturing uncertainty of interior permanent magnet synchronous motor

Journal of Mechanical Science and Technology - This study performed reliability-based robust design optimization (RBRDO) of stator and rotor shape of the IPM type electric motor to reduce the...     

Effect of thermal decomposition products of coal on anodic reactions in direct carbon fuel cells

The effect of inherent volatile matter in fuels on anodic electrochemical reactions was investigated in a direct carbon fuel cell (DCFC). Through thermal decomposition, raw coals, which are used as power source in the DCFC system, release gases under an operating temperature of 700°C. These exhaust gases change the gas composition around the anode and affect the system’s electrochemical reaction. To investigate the effect of produced gases, a comparative study was conducted between Indonesian sub-bituminous coal and char obtained through thermal treatment. The open circuit voltage of raw coal increased to 0.23 V compared with that of char. The maximum power density of raw coal (52 mW/cm²) was also higher than that of char (37 mW/cm²) because of the enhanced electron transport caused by the additional reaction of hydrogen, methane, and carbon monoxide. The influence of volatile matter on the anodic electrolyte-electrode interface was analyzed with the use of the equivalent circuit induced from fitting the impedance data.     

Numerical prediction of morphological change of straight trapezoidal open-channel

This paper presents a numerical model that is capable of simulating the morphological process of the trapezoidal open-channel. The fact that particles on the sloped side bank do not move in the same direction as the flow adds the difficulty in modeling. The lateral distribution model, which distributes the unit discharge over the width, is used for the flow analysis. Vectorial bedload formula by Kovacs and Parker (1994) is used and channel topography is calculated by solving Exner’s equation with the help of sliding algorithm proposed by Menendez et al. (2008). Values of roughness coefficient and lateral eddy viscosity are calibrated using laboratory data sets. Finally, the proposed model is applied to laboratory experiments of Ikeda (1981) and Izumi et al. (1991). Time evolutions of channel cross section and dimensionless shear stress are provided and discussed.     

A modified exhaustive search on a password system using SHA-1

In this paper, we show a method of exhaustive search on a password system that uses SHA-1 iteratively. Our method uses both the technique shown in Steube [16] and a technique for computing repetitions of SHA-1. Combining these two techniques reduces the total number of operations. We also show how to apply our method to MS Office (Microsoft Office) 2007/2010.     

Production of a high concentration of ethanol from potato tuber by high gravity fermentation

To produce a high concentration of ethanol from viscous potato tuber mash, potato tuber mash containing high contents of solids (28%) was prepared by grinding the potato tuber without the addition of water. The viscosity of the potato mash was reduced by using Viscozyme (0.1%) at 50°C for 30 min. The potato mash was then liquefied using Liquozyme (0.1%) at 90°C for 30 min and optimal conditions for the simultaneous saccharification and fermentation (SSF) of the potato mash for ethanol production were investigated using statistical methods. Using 2⁴ factorial design, saccharifying-enzyme and incubation temperature were found to be important factors. Using response surface methodology, the optimal saccharifying-enzyme dosage and incubation temperature were determined to be 1.45 AGU/g dry matter and 31.3°C, respectively. Under these optimal conditions for SSF, 14.92%(v/v) ethanol with 91.0% of theoretical yield was produced after 60 h, and all the starch was completely used up.     

The influence of hydrogen-enriched gas on the performance of lean NOx trap catalyst for a light-duty diesel engine

Modern diesel engines have improved engine fuel economy and significantly reduced nitrogen oxides (NO_x) and particulate matter (PM) emissions achieved by advances in both combustion and exhaust aftertreatment technologies. Recently, it has been shown that the vehicle emissions can be further improved by several catalytic systems including fuel reformers and aftertreatment systems, such as the Lean NO_x Trap (LNT). This NO_x removal system, called LNT, absorbs NO_x under lean exhaust gas conditions and releases NO_x under rich conditions. This technology can provide high NO_x conversion efficiency, but the right amount of reducing agent should be supplied into the catalytic converter under appropriate conditions.     

Melt‐intercalation nanocomposites with fluorinated polymers and a correlation for nanocomposite formation

Various fluorinated polymers were investigated to produce polymer nanocomposites with special clays. Natural and organically treated montmorillonite clays were melt‐compounded with the polymers. Characterization by wide‐angle X‐ray scattering and transmission electron microscopy showed the separation of montmorillonite layers and the formation of polymer nanocomposites. Organically treated montmorillonite clay dispersed in poly(vinylidene fluoride) and various vinylidene fluoride copolymers and formed nanocomposites. Natural and organophilic clays were not well dispersed in other fluorinated copolymers and polyethylene. A correlation was developed for the formation of polymer–clay nanocomposite structures in chlorinated and fluorinated polymers in terms of the dielectric constant. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 1061–1071, 2004     

Assessing Effects of Task and Data Distribution on the Effectiveness of Visual Encodings

In addition to the choice of visual encodings, the effectiveness of a data visualization may vary with the analytical task being performed and the distribution of data values. To better assess these effects and create refined rankings of visual encodings, we conduct an experiment measuring subject performance across task types (e.g., comparing individual versus aggregate values) and data distributions (e.g., with varied cardinalities and entropies). We compare performance across 12 encoding specifications of trivariate data involving 1 categorical and 2 quantitative fields, including the use of x, y, color, size, and spatial subdivision (i.e., faceting). Our results extend existing models of encoding effectiveness and suggest improved approaches for automated design. For example, we find that colored scatterplots (with positionally‐coded quantities and color‐coded categories) perform well for comparing individual points, but perform poorly for summary tasks as the number of categories increases.