Feature integration across space, time, and orientation.

The perception of a visual target can be strongly influenced by flanking stimuli. In static displays, performance on the target improves when the distance to the flanking elements increases—presumably because feature pooling and integration vanishes with distance. Here, we studied feature integration with dynamic stimuli. We show that features of single elements presented within a continuous motion stream are integrated largely independent of spatial distance (and orientation). Hence, space-based models of feature integration cannot be extended to dynamic stimuli. We suggest that feature integration is guided by perceptual grouping operations that maintain the identity of perceptual objects over space and time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Estimation of fixed-point temperatures - A practical approach

Phase transition temperatures can be used for thermometer calibrations in accordance with the ITS-90. For this the thermometer is inserted into a fixed-point cell filled with a highly pure substance. While the substance is melting or freezing the temperature inside the cell remains almost constant and the thermometer measures a plateau in the temperature curve. From this plateau the phase transition temperature needs to be estimated for the calibration of the thermometer. This can be done using different mathematical methods, taking into account various systematic deviations as well as reproducibilities of the results depending on the chosen method, the fixed-point material’s purity and above all the amount of fixed-point material. Hence this article presents results from measurements in miniature fixed-point cells filled with zinc of various purities. The plateau curves were measured at different heating rates and comparatively analysed using five different estimation methods.     

Hydrothermal catalytic production of fuels and chemicals from aquatic biomass

One of the promising avenues for biomass processing is the use of water as a reaction medium for wet or aquatic biomass. This review focuses on the hydrothermal catalytic production of fuels and chemicals from aquatic biomass. Two different regimes for conversion of aquatic biomass in hydrothermal conditions are discussed in detail. The first is hydrothermal liquefaction, and the second is hydrothermal gasification. The goals of these processes are to produce liquid‐fuel‐range hydrocarbons and methane or hydrogen, respectively. The catalytic upgrading of biocrude resulting from noncatalytic liquefaction and the stability and degradation of catalysts in high temperature water are also discussed. The review concludes with a brief discussion of the outlook for and opportunities within the field of hydrothermal catalytic valorization of biomass. Copyright © 2012 Society of Chemical Industry     

The Tensile Response and Fracture Behavior of Four High Strength Specialty Steels

In this technical paper the role of alloy chemistry and secondary processing on tensile response and final fracture behavior of four high strength steels is presented and discussed. The conjoint influence of composition, secondary processing and intrinsic microstructural features in governing stress versus strain response and tensile properties is highlighted. The macroscopic mode and intrinsic microscopic features that result from final fracture of the four high strength steels is discussed. The intrinsic microscopic mechanisms governing tensile deformation and final fracture behavior of the high strength steels are outlined in light of the specific role played by composition, intrinsic microstructural effects and nature of loading.     

Advanced Alumina Composites Reinforced with Titanium-Based Alloys

New (inter)metallic-ceramic composites for high-temperature structural and functional applications are prepared via high-energy ball milling. During compaction by pressureless sintering, dense Al₂O₃/Ti-based alloy composites are formed that consist of inter-connected networks of the ceramic and the (inter)metallic phases. Ti-Al-V/Al₂O₃ and Ti-Al-Nb/Al₂O₃ composites show enhanced damage tolerance over monolithic Al₂O₃, i.e ., fracture toughnesses up to 5.6 MPa·m^0.5 and bending strengths up to 527 MPa. The resistance against abrasive wear is almost doubled with respect to monolithic Al₂O₃ ceramic. Electrical resistivity scales with the ceramic volume fraction and ranges between 0.3 mΩ·cm and 55.1 mΩ·cm, with only a weak temperature dependence ≤700°C.     

Externality, internality, and (in)dispensability of grammatical features in speech production: Evidence from Czech declension and conjugation.

In 3 picture–word experiments, the authors explored the activation of 2 grammatical features in Czech during lexical access: declensional class of nouns and conjugational class of verbs. Experiments 1 and 2 demonstrated congruency effects of declensional and conjugational class, respectively. Picture naming times were reliably longer if the declensional or conjugational classes of the pictures' names and the distractors were incongruent. Experiment 3 explored the origin of the congruency effect in more detail. Congruency effects were obtained for declensional class regardless of whether the target name and the distractor differed in form, speaking for competition at the lemma level. These findings are discussed in comparison with gender congruency effects. The authors propose a differentiation between externally and internally specified features of lemmas, especially with respect to the time course of their activation. Internal features that become available only when the lemma is activated (e.g., gender, declensional or conjugational class of nouns and verbs) can be bypassed or not, depending on the grammatical specification of the earlier available external features (like case or number). Following this argument, supposedly inconsistent findings regarding grammatical gender and declensional or conjugational class can be explained straightforwardly. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Raman investigation of single oxidized carbon nanotubes

The oxidation process of single-walled carbon nanotubes via nitric acid treatment was followed by IR-, UV-Vis-NIR, and single bundle Raman spectroscopy. The introduction of functional, oxygen-containing groups is revealed by an additional absorption band at 1725 cm⁻¹, characteristic of carbonyl stretch vibrations. No significant shift of the optical absorption bands could be detected after oxidation. The combination of atomic force microscopy and confocal scanning resonance-enhanced Raman microscopy was used to investigate thin bundles and, eventually, individual nanotubes in detail. These experiments enabled determination of the dependence of the Raman intensity of the G-line (around 1590 cm⁻¹) on the bundle height for both non-oxidized and oxidized tubes. The Raman cross-section of the oxidized tubes was found to be reduced by a factor of ˜4, compared to the pristine tubes. This observation is ascribed to all tubes within a bundle that are oxidized to the same degree.     

An Improved Method for Solution of the Linear Diffusion Equation

Abstract

The diffusion equation is often solved numerically, using finite-difference techniques. The linear one-dimensional diffusion equation may also be solved by the method of variation of parameters, which yields a solution in the form of an infinite series of products of eigenfunctions and time-varying coefficients. The series form of solution has advantages over finite-difference techniques, but the rate of convergence is often not sufficient to yield useful results. This paper presents an alternative form of the series solution for one-dimensional, Cartesian, homogeneous, and temperature-independent property conditions. The methodology, which exhibits excellent convergence, is applicable to several related problems.