In Situ Observation of Zirconia Particles at 1200°C by High-Resolution Electron Microscopy

Zirconia (ZrO₂) particles (average diameter, 30 nm) were observed in an in situ heating experiment up to 1200°C using a 400-kV high-resolution electron microscope. Thermal vibration of atoms on a (001) surface plane was observed at 1100°C. At 1200°C, grain growth and sintering phenomena were recorded on a videotape, showing (100) lattice planes migrating on a surface of a particle. Direct observation of the sintering process on a lattice level was accomplished for the first time.     

Negative emotion recognition using multimodal physiological signals for advanced driver assistance systems

Artificial Life and Robotics - Recent advanced driver assistance systems’ (ADASs) control cars to avoid accidents, but few of them consider driver’s comfort. To realize comfortable...     

A Possible Magnetic Phase with Scalar Chirality in Solid 3He Layers

We study quantum effects in a system of S = 1/2 spins with two–, three and four–spin exchange interactions on the triangular lattice, a possible model of the nuclear magnetism of solid ³ He layers. The ground state phases found in our previous work are studied by using the linear spin–wave theory. The uuud state shows a very flat spin–wave dispersion, which suggests that this state, though locally stable, will not survive non–linear quantum effects. The tetrahedral state, which has long–range order of a scalar chirality, is found to be stable against spin wave fluctuations. The ground state energies of different phases are compared. Results of numerical analysis of finite size clusters are also presented.     

Adsorption isotherms of pigments from alkali-refined vegetable oils with clay minerals

Adsorption isotherms of pigments from alkali-refined oils (rapeseed, soybean, wheatgerm, safflower, corn, cottonseed and sunflower) were measured to investigate the applicability of the Langmuir and Freundlich equations and to elucidate the adsorption characteristics of pigments on sepiolites and standard activated clay. The Freundlich equation was more applicable to the experimental adsorption isotherms. The equilibrium amount adsorbed, acidity, pore size distribution and inflection of the Freundlich isotherms could be explained by assuming that pigments were adsorbed on the stronger acid sites in smaller pores at low concentration, and then in the larger ones when the concentration increased. The amount adsorbed increased with a rise in adsorption temperatures from 70 to 110°C, and the heat of adsorption was below 10 kcal/mol. The results indicate that pigments were physically adsorbed on the acid sites activated at higher adsorption temperatures.     

Gain and phase margin of optimal memoryless regulator of systems with time-delay

A class of linear quadratic regulators of the system with time-delay in the states is constructed by a memoryless feedback, and its robustness is evaluated. First, a static non-linear perturbation is inserted in the input channel, and a robust stability condition is derived. As its special case, it is shown that the regulator has infinite gain margin and at least 50% gain reduction tolerance. Next, a dynamic linear perturbation is inserted in the same point, and an alternative stability condition is derived. It assures that the regulator has at least 60o phase margin. These results coincide with those of the finite dimensional LQ regulator.     

Trap Levels in Eu and other Rare‐Earth Ions Codoped CaAl2O4 Phosphors

Photoluminescence spectrum, trap depths, and densities of trapped carriers of CaAl₂O₄:Eu phosphor crystals doped with rare‐earth elements were studied using the thermally stimulated luminescence technique. Trap depths and densities of the specimens vary with rare‐earth elements doped as the auxiliary activators. Tm and Nd are found to be effective for the strong afterglow phosphorescence peaking at λ = 442 nm for several hours after the excitation. CaAl₂O₄:Eu phosphor crystals doped with Nd and Tm include high density of carriers trapped at E = 0.59 and 0.52 eV, respectively.     

Compositional Dependence of Normal Spectral Emissivity of Molten Cu-Fe Alloy

Metallurgical and Materials Transactions B - Normal spectral emissivity of molten Cu-Fe alloy with different compositions was measured at the wavelength of 807 nm using an electromagnetic...