Applying an information transmission approach to extract valence electron information from reconstructed exit waves

The knowledge of the valence electron distribution is essential for understanding the properties of materials. However this information is difficult to obtain from HREM images because it is easily obscured by the large scattering contribution of core electrons and by the strong dynamical scattering process. In order to develop a sensitive method to extract the information of valence electrons, we have used an information transmission approach to describe the electron interaction with the object. The scattered electron wave is decomposed in a set of basic functions, which are the eigen functions of the Hamiltonian of the projected electrostatic object potential. Each basic function behaves as a communication channel that transfers the information of the object with its own transmission characteristic. By properly combining the components of the different channels, it is possible to design a scheme to extract the information of valence electron distribution from a series of exit waves. The method is described theoretically and demonstrated by means of computer simulations.     

Designing for collaboration: a study in intergenerational social game design

This paper presents a study of a computer game designed for the elderly, allowing them to train their memory while playing the game. The game supports both a single-player and a multiplayer mode, in which the elderly can play with their friends or family using an embedded video chat application. The main question that is addressed in this paper is how the elderly gamers’ experience is influenced by the possibility to communicate directly with the other players. The study presents a comparison of the game experience and appreciation of older users and their (grand)children playing the game together, with or without the video chat application. Most importantly, the study shows that the added value of video chat is not limited to social contact, but that it also provides opportunities for the younger generation to assist the elderly during the game. In conclusion, the paper points out some intergenerational game design implications, and some future research suggestions.     

Assigning Electronic States in Carbon Nanodots

Luminescent carbon nanodots exhibit enormous potential to be used as functional building blocks in energy conversion devices. Their intrinsic heterogeneity, however, hinders a thorough characterization and subsequently their applicability. In this work, the spectroscopic and electrochemical properties of prototype carbon nanodots were thoroughly studied in solution. Spectro‐electrochemical experiments revealed information on the spectral features of several oxidized and reduced species of our carbon nanodots. Therefore, these experiments were complemented with pulse radiolysis where the spectral signature of the one‐electron oxidized and reduced forms were identified. Both, electrochemically and radiolytically reduced and oxidized products show high reactivity in solution which correlates with an open‐shell character, detected by paramagnetic resonance spectroscopy. The herein presented studies help to understand the complex nature of carbon nanodots and serve to overcome difficulties in device fabrication.     

Beating hydrogen with its own weapon: Nano-twin gradients enhance embrittlement resistance of a high-entropy alloy

High-entropy alloys have shown exceptional damage tolerance at cryogenic temperatures. Here we report that this essential property can be maintained even when exposing the equiatomic CoCrFeMnNi alloy to the most detrimental environmental condition known to metals, hydrogen. This is enabled by a self-accommodation mechanism: the higher the local hydrogen content, the higher the twin formation rate as hydrogen reduces the stacking fault energy. Thus, the hydrogen’s through thickness diffusion gradient translates into a nano-twin gradient that counteracts material weakening by enhanced local strengthening. The concept targets applications under harsh and cryogenic conditions, such as encountered in arctic, offshore, energy and liquid gas chemical processing, and transport operations. The new mechanism opens a pathway to the design of alloys that withstand heavy mechanical loading under cryogenic and hydrogen-containing conditions.     

Enhancing methane production by anaerobic co-digestion of extruded organic wastes from slaughterhouse and vegetable market in batch and continuous processes

Clean Technologies and Environmental Policy - The organic wastes generated from centralized wholesale markets from urban centres are predominantly disposed in dumpsites/landfills. Although...