In situ SEM studies on strain sensing mechanisms of PPy-coated electrically conducting fabrics

This paper studies a flexible fabric strain sensor from PPy-coated fabrics prepared by a chemical vapor deposition method under low temperature, placing an emphasis on mechanisms of its strain sensing behavior. In situ tensile tests in a scanning electron microscope (SEM) were conducted for PPy-coated electrically conducting yarns, which were prepared by the same procedure as that for the PPy-coated fabrics, enabling it possible to observe in situ the phenomena that occurred on the fiber surface during fabric deformation. The investigation revealed that the PPy-coated nylon/polyurethane fabrics exhibited a high strain sensitivity of over 400 and very large workable strain range greater than 50%, which mainly attributes to the high conductivity and crack-opening and crack-closing mechanisms of PPy-coated polyurethane yarn, as well as the excellent properties of knitted fabric structure.     

The atomic absorption spectrometric determination of arsenic,bismuth, lead,antimony, selenium and tin with a flame-heated silica t-tube after hydride generation

A modified technique with a simple T-tube for atomisation held above conventional atomic absorption burners is described. The absolute sensitivities are in the range 0.3–11 ng and the r.s.d. is usually below 5%. It is confirmed that prior oxidation of lead markedly increases the sensitivity.     

Moments over short intervals

An asymptotic result for the kth moment (k 9) of the error term in the Dirichlet divisor problem over short intervals is obtained, which improves on an earlier result of Nowak.Received: 22 April 2004     

Pitch ranking ability of cochlear implant recipients: a comparison of sound-processing strategies

Pitch ranking of sung vowel stimuli, separated in fundamental frequency (F0) by half an octave, was measured with a group of eleven Nucleus 24 cochlear implant recipients using different sound coding strategies. In three consecutive studies, either two or three different sound coding strategies were compared to the Advanced Combinational Encoder (ACE) strategy. These strategies included Continuous Interleaved Sampling (CIS), Peak Derived Timing (PDT), Modulation Depth Enhancement (MDE), F0 Synchronized ACE (FOSync), and Multi-channel Envelope Modulation (MEM), the last four being experimental strategies. While pitch ranking results on average were poor compared to those expected for most normal hearing listeners, significantly higher scores were obtained using the MEM, MDE, and FOSync strategies compared to ACE. These strategies enhanced coding of temporal F0 cues by providing deeper modulation cues to F0 coincidentally in time across all activated electrodes. In the final study, speech recognition tests were also conducted using ACE, CIS, MDE, and MEM. Similar results among all strategies were obtained for word tests in quiet and between ACE and MEM for sentence tests in noise. These findings demonstrate that strategies such as MEM may aid perception of pitch and still adequately code segmental speech features as per existing coding strategies.     

Measurement of the D(s)+ lifetime

A high statistics measurement of the D(s)+ lifetime from the Fermilab fixed-target FOCUS photoproduction experiment is presented. We describe the analysis of the two decay modes, D(s)+ --> phi(1020)pi+ and D(s)+ -->K*(892)0K+, used for the measurement. The measured lifetime is 507.4 +/- 5.5(stat) +/- 5.1(syst) fs using 8961 +/- 105 D(s)+ --> phi(1020)pi+ and 4680 +/- 90 D(s)+ --> K*(892)0K+ decays. This is a significant improvement over the present world average.     

Hippocampal lesions facilitate instrumental learning with delayed reinforcement but induce impulsive choice in rats

Background  

Animals must frequently act to influence the world even when the reinforcing outcomes of their actions are delayed. Learning with action-outcome delays is a complex problem, and little is known of the neural mechanisms that bridge such delays. When outcomes are delayed, they may be attributed to (or associated with) the action that caused them, or mistakenly attributed to other stimuli, such as the environmental context. Consequently, animals that are poor at forming context-outcome associations might learn action-outcome associations better with delayed reinforcement than normal animals. The hippocampus contributes to the representation of environmental context, being required for aspects of contextual conditioning. We therefore hypothesized that animals with hippocampal lesions would be better than normal animals at learning to act on the basis of delayed reinforcement. We tested the ability of hippocampal-lesioned rats to learn a free-operant instrumental response using delayed reinforcement, and what is potentially a related ability – the ability to exhibit self-controlled choice, or to sacrifice an immediate, small reward in order to obtain a delayed but larger reward.     

Unexpectedly superior enantioselectivity for trans-stilbene cis-dihydroxylation over anchored triosmium carbonyl species in confined Al-MCM-41 channels

Superior enantioselectivity in the dihydroxylation of trans-stilbene catalysed by anchored triosmium carbonyl species without using a chiral modifier is observed inside sterically congested MCM-41 channels; this effect is more pronounced through the introduction of surface Al sites into the silicate.     

On a flexible elimination algorithm with applications to panel element equations

A flexible elimination algorithm is presented and is appliedto the solution of dense systems of linear equations. Propertiesof the algorithm are exploited in relation to panel elementmethods for potential flow and subsonic compressible flow. Furtherproperties in relation to distributed computing are also discussed.     

Aqueous emulsion containing fluorous cobalt species in supercritical CO2 for catalytic air oxidation of toluene

An aqueous emulsion containing ionic Co2+ and Br- species stabilised by fluorous surfactant-like species in supercritical CO2-air mixture acts as a nano-reactor with excellent interfacial contacts of all necessary hydrophilic/hydrophobic species, which renders safe operation of catalytic aerial oxidation of toluene at high yields.