Thick-film coating of hexaaluminate catalyst on ceramic substrates for high-temperature combustion

Structural and chemical stabilities of substituted hexaaluminate catalyst films coated on some ceramic substrates were investigated for high-temperature combustion applications. The thermal stability of the hexaaluminate catalyst films on -SiC substrate was greatly enhanced by the insertion of both, a neat hexaaluminate and mullite intermediate layer. Pure alumina substrate was preferable in depositing the substituted hexaaluminate catalyst film to pure mullite, mullite-zirconia composite, or partially stabilized zirconia substrates. The thermal stability of the hexaaluminate catalyst films, coated on these oxide ceramic substrates, greatly depended on the extent of diffusion of components between the film and substrate at high temperatures. The substituted hexaaluminate microparticles in the film rearranged during the sintering process above 1400°C, and their (00l) plane oriented parallel to the surface of the substrate. Manganese introduced in the substituted hexaaluminate films or disks gradually decreased with an increase in the heat-treatment temperature because of its volatilization.     

Modeling and Recognition of Driving Behavior Based on Stochastic Switched ARX Model

This paper presents the development of the modeling and recognition of human driving behavior based on a stochastic switched autoregressive exogenous (SS-ARX) model. First, a parameter estimation algorithm for the SS-ARX model with multiple measured input-output sequences is developed based on the expectation-maximization algorithm. This can be achieved by extending the parameter estimation technique for the conventional hidden Markov model. Second, the developed parameter estimation algorithm is applied to driving data with the focus being on driver's collision avoidance behavior. The driving data were collected using a driving simulator based on the cave automatic virtual environment, which is a stereoscopic immersive virtual reality system. Then, the parameter set for each driver is obtained, and certain driving characteristics are identified from the viewpoint of switched control mechanism. Finally, the performance of the SS-ARX model as a behavior recognizer is examined. The results show that the SS-ARX model holds remarkable potential to function as a behavior recognizer.     

Preparation of macroreticular anion exchange membrane and its behavior relating to organic fouling

Base membranes were prepared by coating a monomer mixture consisting of styrene–divinylbenzene–polybutadiene–t-amyl alcohol onto a polypropyrene cloth and subsequently by polymerizing the monomers. The resultant base membranes were chloromethylated and then quaternized. Thus, macroreticular anion exchange membranes were prepared and their properties were investigated. Furthermore, the organic fouling of the membranes was studied by using Na dodecylbenzenesulfonate as a foulant. The resistibility of the membranes was dependent on the balance between the porosity of the membranes and the foulant quantity.     

Influence of external additives on the preservation of carthamin red colour: an introductory test for utilizing carthamin as a herbal colorant of processed foods

A number of carbohydrates and related compounds was admixed with carthamin in an acidic buffer solution and the effect of the test chemicals on carthamin stability examined at low temperature. Monosaccharides were scarcely effective, although slightly accentuated values were obvious in thed-forms (d-forml-form=1.31.0). Disaccharides were less effective for carthamin red preservation (dimermonomer=1.01.8). However, a high level of colour conservation was observed with sugar alcohols. Both polyethylene glycol and glycerine very effectively protected carthamin from bleaching in solution: the colour preservation rates calculated were 91.3% and 83.8%, respectively, after 24 h incubation at 5° C in the dark. Gelatine was also effective for maintaining carthamin colour (preservation rate: 81.3%). The results are assessed in connection with utilizing carthamin as a herbal colorant of processed foods.

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Einfluß von Zusatzstoffen nach Konservierung des Carthaminrots. Ein Test für die Verwertung von Carthamin als pflanzliche Farbe für verarbeitete Lebensmittel

Zusammenfassung Eine Zahl von Kohlenhydraten und verwandten Verbindungen wurden mit Carthamin in saurer Pufferlösung vermischt und die Wirkung auf dessen Stabilität bei niederer Temperatur getestet. Die Monosaccharide waren kaum effektiv, jedoch died-Form beschleunigte etwas stärker (d-Forml-Form=1.31.0). Die Disaccharide waren weniger wirksam auf die Farberhaltung (DimerMonomer=1.01.8). Jedoch wurde eine gute Farbkonservierung mit Zuckeralkoholen beobachtet, sowohl Polyethyleneglycol und auch Glycerin schützten Carthamin sehr wirksam zu 91,3 bzw. 83,8% nach 24h Einwirkung. Auch Gelatine war sehr farberhaltend (81,3%). Die Resultate wurden in bezug auf ihre Verwendung von Carthamin als Farbe für industriell verarbeitete Lebensmittel beurteilt.

     

Probability of cochannel interference in the case of noncoherentphasor addition with unequal powers in Rayleigh fading environments

New, closed form expressions are derived for calculation of the probability of cochannel interference (PCI) in Rayleigh fading environments when interfering phasors with unequal mean powers add noncoherently in the receiver. Expressions enable PCI calculation at every point within a cell and/or cluster, both in base stations and mobile units     

In Situ Time-Resolved XAFS of Transitional States of Pt/C Cathode Electrocatalyst in an MEA During PEFC Loading with Transient Voltages

The transitional states of a Pt/C cathode electrocatalyst in the membrane electrode assembly of a polymer electrolyte fuel cell during loading with transient voltages were systematically analyzed by in situ time-resolved X-ray absorption fine structure with time resolution of 100 ms. The results suggest that the local coordination of the Pt cathode electrocatalyst was unaffected by the transient voltages during both rapid and gradual loading over 0–30 s.     

Friction and wear of self-mated SiC and Si3N4 sliding in water

The friction and wear of self-mated SiC and Si₃N₄ with different initial roughness sliding in water were investigated with pin-on-disk apparatus at normal load of 5 N and sliding speed of 120 mm/s in ambient condition. It was found that, for self-mated Si₃N₄, the wear mechanism for surface smoothening to obtain low friction was tribochemical wear, but for self-mated SiC, it changed from mechanical wear into tribochemical wear with increasing sliding cycles. After running-in in water, self-mated Si₃N₄ exhibited lower steady-state friction coefficient than self-mated SiC did. For these two ceramics, initial and steady-state friction coefficients were hardly dependent on initial roughness. Initial roughness mainly affected the running-in period. The larger the initial roughness, the longer the running-in period, but the running-in period was much shorter for self-mated Si₃N₄ at each initial roughness than that for self-mated SiC.     

Investigation of soil deformation characteristics during pullout of a ribbed reinforcement using X-ray micro CT

Steel-strip reinforced earth walls stabilize through the pullout resistance of the reinforcements. Soil dilation during the pullout of ribbed reinforcements may contribute to the evolution of pullout resistance; however, few studies have clarified this mechanism by investigating how soils behave with increasing pullout displacement. The ribs of the reinforcements enhance the pullout resistance, although the influence of the rib dimensions on the evolution of pullout resistance with increasing pullout displacement has not been sufficiently revealed. In the present study, a triaxial pullout apparatus is developed and pullout tests are conducted using ribbed reinforcements with different rib-inclination angles under isotropic stress. The displacement and strain fields in the soils during the pullout of the reinforcements are investigated by X-ray micro CT and a digital image correlation technique. It is found that larger rib-inclination angles provide higher pullout resistance at an early stage of the pullout because of the higher bearing resistance related to the more significant soil densification above the ribs. With increasing pullout displacement, the reinforcements with different rib-inclination angles come to behave as almost one in the same since a rigid soil wedge related to the passive soil failure is generated above the ribs. This tendency results in similar soil deformation characteristics and pullout resistance levels for every reinforcement beyond the soil failure state, although the rib-inclination angles are different.