Steam reforming of model compounds and fast pyrolysis bio-oil on supported noble metal catalysts

The production of hydrogen by steam reforming of bio-oils obtained from the fast pyrolysis of biomass requires the development of efficient catalysts able to cope with the complex chemical nature of the reactant. The present work focuses on the use of noble metal-based catalysts for the steam reforming of a few model compounds and that of an actual bio-oil. The steam reforming of the model compounds was investigated in the temperature range 650-950 degrees C over Pt, Pd and Rh supported on alumina and a ceria-zirconia sample. The model compounds used were acetic acid, phenol, acetone and ethanol. The nature of the support appeared to play a significant role in the activity of these catalysts. The use of ceria-zirconia, a redox mixed oxide, lead to higher H-2 yields as compared to the case of the alumina-supported catalysts. The supported Rh and Pt catalysts were the most active for the steam reforming of these compounds, while Pd-based catalysts poorly performed. The activity of the promising Pt and Rh catalysts was also investigated for the steam reforming of a bio-oil obtained from beech wood fast pyrolysis. Temperatures close to, or higher than, 800 degrees C were required to achieve significant conversions to COx and H-2 (e.g., H-2 yields around 70%). The ceria-zirconia materials showed a higher activity than the corresponding alumina samples. A Pt/ceria-zirconia sample used for over 9 h showed essentially constant activity, while extensive carbonaceous deposits were observed on the quartz reactor walls from early time on stream. In the present case, no benefit was observed by adding a small amount of O-2 to the steam/bio-oil feed (autothermal reforming, ATR), probably partly due to the already high concentration of oxygen in the bio-oil composition. (c) 2005 Elsevier B.V. All rights reserved.

Accounting Undergraduates’ Perceptions of Cooperative Learning as a Model for Enhancing their Interpersonal and Communication Skills to Interface Successfully with Professional Accountancy Education and Training

To interface effectively with professional accountancy training, accounting educationalists should ensure that they turn out graduates who possess the interpersonal and communication skills required of today's accountant. Attainment of these skills is promoted by group work. However, little empirical evidence exists to help academics make an informed choice about which form of group learning enhances interpersonal and communication skills. This paper addresses this deficiency by comparing perceptions of skills enhancement between accounting students who experienced traditional or simple group learning and those who undertook cooperative learning. The findings reveal that the cooperative learning cohort perceived their learning experience to be significantly more effective at enhancing interpersonal and communication skills than that of the simple group learning cohort. This study provides evidence that cooperative learning is a more effective model for delivering interpersonal and communication skills than simple group learning, thereby creating a more successful interface between academic accounting and professional accountancy training.

Turbo channel estimation and equalisation for a superposition-based cooperative system

This study investigates the superposition-based cooperative transmission system. In this system, a key point is for the relay node to detect data transmitted from the source node. This issued was less considered in the existing literature as the channel is usually assumed to be flat fading and a priori known. In practice, however, the channel is not only a priori unknown but subject to frequency selective fading. Channel estimation is thus necessary. Of particular interest is the channel estimation at the relay node which imposes extra requirement for the system resources. The authors propose a novel turbo least-square channel estimator by exploring the superposition structure of the transmission data. The proposed channel estimator not only requires no pilot symbols but also has significantly better performance than the classic approach. The soft-in-soft-out minimum mean square error (MMSE) equaliser is also re-derived to match the superimposed data structure. Finally computer simulation results are shown to verify the proposed algorithm.

A Computer Music Retrospective

A composer who has worked in the field of computer music for the last 25 years reflects on how technological developments during that time have affected his work in computer music, instrumental music and hybrid combinations of the two. The compositional trajectories traced here often run parallel to opportunities afforded by the evolution of computer technology suitable for the generation of digital audio.

Theoretical and experimental correlations of gas dissolution, diffusion, and thermodynamic properties in determination of gas permeability and selectivity in supported ionic liquid membranes

Supported ionic liquid membranes (SILMs) has the potential to be a new technological platform for gas/organic vapour separation because of the unique non-volatile nature and discriminating gas dissolution properties of room temperature ionic liquids (ILs). This work starts with an examination of gas dissolution and transport properties in bulk imidazulium cation based ionic liquids [C_nmim][NTf2] (n = 2.4, 6, 8.10) from simple gas H₂, N₂, to polar CO₂, and C₂H₆, leading to a further analysis of how gas dissolution and diffusion are influenced by molecular specific gas-SILMs interactions, reflected by differences in gas dissolution enthalpy and entropy. These effects were elucidated again during gas permeation studies by examining how changes in these properties and molecular specific interactions work together to cause deviations from conventional solution–diffusion theory and their impact on some remarkably contrasting gas perm-selectivity performance. The experimental perm-selectivity for all tested gases showed varied and contrasting deviation from the solution–diffusion, depending on specific gas-IL combinations. It transpires permeation for simpler non-polar gases (H₂, N₂) is diffusion controlled, but strong molecular specific gas-ILs interactions led to a different permeation and selectivity performance for C₂H₆ and CO₂. With exothermic dissolution enthalpy and large order disruptive entropy, C₂H₆ displayed the fastest permeation rate at increased gas phase pressure in spite of its smallest diffusivity among the tested gases. The C₂H₆ gas molecules “peg” on the side alkyl chain on the imidazulium cation at low concentration, and are well dispersed in the ionic liquids phase at high concentration. On the other hand strong CO₂-ILs affinity resulted in a more prolonged “residence time” for the gas molecule, typified by reversed CO₂/N₂ selectivity and slowest CO₂ transport despite CO₂ possess the highest solubility and comparable diffusivity in the ionic liquids. The unique transport and dissolution behaviour of CO₂ are further exploited by examining the residing state of CO₂ molecules in the ionic liquid phase, which leads to a hypothesis of a condensing and holding capacity of ILs towards CO₂, which provide an explanation to slower CO₂ transport through the SILMs. The pressure related exponential increase in permeations rate is also analysed which suggests a typical concentration dependent diffusion rate at high gas concentration under increased gas feed pressure. Finally the strong influence of discriminating and molecular specific gas-ILs interactions on gas perm-selectivity performance points to future specific design of ionic liquids for targeted gas separations.

Bridging the Gap between CO Adsorption Studies on Gold Model Surfaces and Supported Nanoparticles

A happy medium: Volumetric adsorption of carbon monoxide at 308 K and UHR-HAADF-STEM, HREM, and computer modeling techniques were compared. Experimental CO/Au ratios at saturation coverage for two supported gold catalysts were shown to fit very well the predictions of a nanostructural model that considers CO adsorption on gold sites with coordination numbers of less than eight.

Common-sense knowledge for a computer vision system for human action recognition

This work presents a novel approach for human action recognition based on the combination of computer vision techniques and common-sense knowledge and reasoning capabilities. The emphasis of this work is on how common sense has to be leveraged to a vision-based human action recognition so that nonsensical errors can be amended at the understanding stage. The proposed framework is to be deployed in a realistic environment in which humans behave rationally, that is, motivated by an aim or a reason. © 2012 Springer-Verlag.

Swarm scheduling approaches for work-flow applications with security constraints in distributed data-intensive computing environments

The scheduling problem in distributed data-intensive computing environments has become an active research topic due to the tremendous growth in grid and cloud computing environments. As an innovative distributed intelligent paradigm, swarm intelligence provides a novel approach to solving these potentially intractable problems. In this paper, we formulate the scheduling problem for work-flow applications with security constraints in distributed data-intensive computing environments and present a novel security constraint model. Several meta-heuristic adaptations to the particle swarm optimization algorithm are introduced to deal with the formulation of efficient schedules. A variable neighborhood particle swarm optimization algorithm is compared with a multi-start particle swarm optimization and multi-start genetic algorithm. Experimental results illustrate that population based meta-heuristics approaches usually provide a good balance between global exploration and local exploitation and their feasibility and effectiveness for scheduling work-flow applications. © 2010 Elsevier Inc. All rights reserved.

Raiffeisenism abroad: why did German cooperative banking fail in Ireland but prosper in the Netherlands?

Why did imitations of Raiffeisen’s rural cooperative savings and loans associations work well in some European countries, but fail in others? This article considers the example of Raiffeisenism in Ireland and in the Netherlands. Raiffeisen banks arrived in both places at the same time, but had drastically different fates. In Ireland they were almost wiped out by the early 1920s, while in the Netherlands they proved to be a long-lasting institutional transplant. Raiffeisen banks were successful in the Netherlands because they operated in niche markets with few competitors, while rural financial markets in Ireland were unsegmented and populated by long- established incumbents, leaving little room for new players, whatever their institu- tional advantages. Dutch Raiffeisen banks were largely self-financing, closely integrated into the wider rural economy, and able to take advantage of economic and religious divisions in rural society. Their Irish counterparts were not.

Episodic Reasoning for Vision-Based Human Action Recognition

Smart Spaces, Ambient Intelligence, and Ambient Assisted Living are environmental paradigms that strongly depend on their capability to recognize human actions. While most solutions rest on sensor value interpretations and video analysis applications, few have realized the importance of incorporating common-sense capabilities to support the recognition process. Unfortunately, human action recognition cannot be successfully accomplished by only analyzing body postures. On the contrary, this task should be supported by profound knowledge of human agency nature and its tight connection to the reasons and motivations that explain it. The combination of this knowledge and the knowledge about how the world works is essential for recognizing and understanding human actions without committing common-senseless mistakes. This work demonstrates the impact that episodic reasoning has in improving the accuracy of a computer vision system for human action recognition. This work also presents formalization, implementation, and evaluation details of the knowledge model that supports the episodic reasoning.