Multimodal perception in the control of infant reaching.

Six-month-old infants were presented with sounding objects under 3 conditions of illumination: in full vision, in the dark with target location specified by a glowing and sounding object, and in the dark with location specified by sound alone. Reaching behavior was videotaped with an infrared camera, and hand movement was measured by infrared-emitting diodes on the hand that were tracked by a motion analysis system. No differences were found in reaching behavior for objects in the light and glowing objects in the dark. Reaches for sounding objects in the dark had higher speeds, shorter durations, and more errors compared to the other 2 conditions. These findings indicate that vision of the hand did not appear to affect infants' reaching in this situation, whereas vision of the target did. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Tribological Model for Chocolate in the Mouth: General Implications for Slurry-Lubricated Hard/Soft Sliding Counterfaces

We have investigated the rheological and lubrication properties of molten chocolate samples. To this end, a series of chocolate samples having various textural/compositional features have been prepared. The rheological properties of the chocolate samples are discussed in terms of the Casson model. The lubrication properties of the molten chocolate samples have been characterized by means of pin-on-disk tribometry. For the tribo-pairs, zirconia (ZrO₂) and poly(tetrafluoroethylene) (PTFE) have been used in all permutations for both slider (pin) and track (disk), providing the four tribo-pair combinations; ZrO₂/ZrO₂, PTFE/ZrO₂, ZrO₂/PTFE, and PTFE/PTFE. The results showed that both the rheological and lubrication properties of the chocolate samples are strongly influenced by the textural and compositional characteristics. The lubrication properties are further influenced by the choice of the tribo-pair. The different lubrication properties of the chocolate samples at different tribo-pairs are discussed in terms of particle behavior in the surrounding region of the inlet of the sliding tribo-pairs.     

Solid-State Ionics: Roots, Status, and Future Prospects

This review represents the authors' view of the evolution of solid-state ionics over approximately the past 100 years. A brief history, introducing milestones of the development of this discipline, is followed by a short summary of the theory of ionic conduction in the bulk and the more recently developed theory of ionic conduction at interfaces. The central part of the article gives examples of ionic-conducting materials systems with structures ranging from one- to three-dimensional disorder. Important experimental techniques for analyzing ionic conduction, including alternating-current impedance spectroscopy, direct-current coulometry, and direct-current current-voltage measurements with blocking electrodes, are also summarized. The main technological applications, that is, batteries, solid-oxide fuel cells, electrochemical sensors, electrochromic windows, and oxygen-separation membranes, are reviewed. Finally, new concepts in solid-state ionics are presented, including the investigation of new materials (such as nanostructured phases), the study of boundaries (for example, using microelectrodes), the development of computational techniques, and the connections with other classes of materials (notably magnetic and semiconducting materials).     

Load Response to Voltage Variations and Dynamic Stability

This paper discusses the influence of the load response to the voltage on the stability of a power system. A theorical study is undertaken in an attempt to understand the process involved. This is followed by an examination of the effects on the stability of the Hydro-Québec power system. It appears that critical values of the Characteristic coefficients of the load exist, below which the system becomes unstable, and that even for a system as large as Hydro-Québec's it is advisable to adjust the controls of the excitation systems in terms of these coefficients.     

Deregulation as a switch of regime: Price effects using a modified Hotelling rule

Concern over rising energy prices has led to support for government intervention to regulate the price of domestic non-renewable energy resources. However, US policy makers appear to be looking more towards competition, rather than regulation, to decide who will provide energy resources and how these will be priced. This paper models possible dynamic price effects occasioned by the removal of a regulatory constraint. The analysis focuses on a government decision to eliminate binding price ceilings on a non-renewable (energy) substitute when the incumbent resource is monopolistically controlled (using deregulation of natural gas as an illustration). Under certain conditions it is shown that one will get continuity of marginal revenue and a fall in the world price following decontrol (the expiration of a patent or a decision to grant mineral rights on federal land). In general, however, the model suggests that both marginal revenue and prices will be discontinuous and that the discontinuity is likely to result in a fall in price.     

Radical Polymerisation of Methylacrylate Initiation by the Azidoadamantane / Copper Bromide System

Summary A new initiating system, azidoadamantane/CuBr, for the radical polymerisation of methylacrylate was found. Polymerisations occur as well at 50°C in toluene solution as in bulk at 70°C. A kinetic study seems to show a monomer consumption of first order in monomer concentration. However, despite a polydispersity index lower than 2, the value and the constancy of Mn during the whole polymerisation time gave an indication of a non controlled polymerisation. This is assumed to be due to the double role played by the azide function: strong complexing agent for copper ions and radical initiatior for the polymerisation, so that the presence of an additional ligand, i.e. bipyridine, is not necessary. Received: 15 October 2002/Revised version: 31 March 2003/ Accepted: 14 April 2003 Correspondence to Hung Anh Nguyen     

Regioselective end‐functionalization of polylactide oligomers with D‐glucose and D‐galactose

D ‐glucose and D ‐galactose end‐functionalized polylactide oligomers were synthesized by controlled ring‐opening polymerization of lactide using aluminium triisopropoxide, triethylaluminium or stannous octoate as promoter. Accordingly, two selectively protected monosaccharides were studied as co‐initiators, either 1,2;5,6‐di‐O‐isopropylidene‐α‐D ‐glucofuranose (1) and 1,2;3,4‐di‐O‐isopropylidene‐α‐D ‐galactopyranose (2). In contrast to what is known in polymerization of ?‐caprolactone, both protected monosaccharides proved to be efficient co‐initiators and yielded end‐functionalized polylactide chains with controlled regioselectivity (C‐3 or C‐6 linkage), predictable molecular weights and narrow molecular weight distributions. © 2003 Society of Chemical Industry