Transparency and Stability of Bilateral Kinesthetic Teleoperation with Time-Delayed Communication

This paper presents a novel control approach that simultaneously ensures stability and transparency of bilateral kinesthetic teleoperation in case of communication delay. The approach rests upon a straight-forward combination of two-port lossless line theory, proper adaptation of line terminating impedance functions and situation dependent switching of adaptation filters. Application of a resulting transparency oriented control strategy to 1- or multi-DoF telemanipultion systems leads to improvements in human operator's presence feeling and task performance.     

Impact of sorbitol on the thermostability and heat-induced gelation of bovine serum albumin

The influence of sorbitol (0–40 wt.%) on the thermal denaturation and gelation of bovine serum albumin (BSA, pH 7.0) in aqueous solution has been studied. The effect of sorbitol on heat denaturation of 0.5 wt.% BSA solutions was measured using ultrasensitive differential scanning calorimetry. The unfolding process was irreversible and was characterized by the thermal denaturation temperature (T_m). As the sorbitol concentration increased from 0 to 40 wt.%, T_m increased from 73.0 to 80.9 °C. The rise in T_m was attributed to the increased thermal stability of the globular state of BSA relative to its native state. The dynamic shear rheology of 4 wt.% BSA solutions containing 200 mM NaCl was monitored as they were heated from 30 to 90 °C at 1.5 °C min⁻¹, held at 90 °C for 120 min, and then cooled back to 30 °C at −1.5 °C min⁻¹. Sorbitol increased the protein gelation temperature (ΔT_gel +10 °C for 40 wt.% sorbitol), decreased the isothermal gelation rate at 90 °C, but increased the final shear modulus of the gels cooled to 30 °C. The impact of sorbitol on gel characteristics was attributed to its ability to increase protein thermal stability, increase the attractive force between proteins and decrease the protein–protein collision frequency.     

Symbolic model checking for channel-based component connectors

This paper introduces a temporal logic framework to reason about the coordination mechanisms and data flow of exogenous coordination models. We take a CTL-like branching time logic, augmented with regular expressions that specify the observable I/O-operations, as a starting point. The paper provides the syntax and semantics of our logic and introduces the corresponding model checking algorithm. The second part of the paper reports an implementation that relies on a symbolic representation of the coordination network and the connected components by means of binary decision diagrams. A couple of examples are given to illustrate the efficiency of the model checking techniques and their implementation.     

Symbolic Model Checking for Channel-based Component Connectors

The paper reports on the foundations and experimental results with a model checker for component connectors modelled by networks of channels in the calculus Reo. The specification formalisms is a branching time logic that allows to reason about the coordination principles of and the data flow in the network. The underlying model checking algorithm relies on variants of standard automata-based approaches and model checking for CTL-like logics. The implementation uses a symbolic representation of the network and the enabled I/O-operations by means of binary decision diagrams. It has been applied to a couple examples that illustrate the efficiency of our model checker.     

Abbrandbedingtes schwellen hochdichter oxidischer htr-brennstoffkerne

BISO- or TRISO-coated high-density UO₂ kernels with varying degrees of enrichment and with mean kernel diameters between 220 and 820 μm have been irradiated at 900–1300°C to burn-ups between 0.5 and 52.5% fima. From microradiographic measurements, burn-up-induced increases in kernel diameters were deduced: these ranged up to 12.8% (corresponding to 43.5% volume increase). In the low burn-up region, kernel diameters increase approximately linearly with burn-up. This increase is more pronounced for small kernels than for larger ones, it is higher for TRISO-coated kernels than for BISO-coated ones. In the high burn-up region, the dimensional increase seems to become independent of burn-up. (U, Th)O₂ kernels show more swelling than pure UO₂ kernels with identical diameters. All these results can be explained, at least qualitatively, taking into account results from fission-gas release measurements.     

Universal gelling agent for the control of hazardous liquid spills

Under contract to the U.S. Environmental Protection Agency, Calspan Corporation developed methods to treat, control and monitor spilled hazardous materials. One of the most successful spill countermeasures applied was a dry, finely-granulated blend which would, within seconds after contact with spilled liquids, begin their transformation into tough, immobile gels which could be easily controlled and removed. This blend is a “universal gelling agent” in the sense that it can immobilize essentially all hazardous liquid spills without foreknowledge of the liquid composition. The blend contains powdered polymeric components optimized separately for interaction with aqueous liquids, chlorinated organics, alcohols, and nonpolar hydrocarbons. It also contains a fumed silica fluidizer, which provides ease of field application and imparts longer term stiffening of all gels formed. The “universal gelling agent” has been demonstrated to be effective on a variety of medium scale (55-gallon drum) spills on both land and water. For special uses, such as organophosphorus pesticide spill control, the blend can be reformulated to include de-toxifying (oxidizing, hydrolytic) ingredients as well.     

Non-Coherent Pulse Detection with a Large Predetection Bandwidth

For a non-coherent detection circuit with a broad-band pre-detection filter and narrow-band post-detection-filter, equations are obtained for the probability of detection of a pulsed sinusoidal signal embedded in white noise. The equations can be used to calculate the detection probability directly from envelope form, noise power at the input of the circuit and the impulse response of the postdetection filter. The application of the equations is illustrated with reference to a sliding correlator acquisition circuit for PN-code generators.