Coupling of head and body movement with motion of the audible environment.

The authors asked whether standing posture could be controlled relative to audible oscillation of the environment. Blindfolded sighted adults were exposed to acoustic flow in a moving room, and were asked to move so as to maintain a constant distance between their head and the room. Acoustic flow had direct (source) and indirect (reflected) components. Participants exhibited strong coupling of postural motion with room motion, even when direct information about room motion was masked and was available only in reflected sound. Patterns of hip–ankle coordination closely resembled patterns observed in previous research involving coupling of sway with a visible moving room. The results demonstrate that blindfolded adults can control the dynamics of stance relative to motion of the audible environment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Metamodels in Europe: Languages, Tools, and Applications

Editor's note:This article provides an overview of current efforts in Europe for using metamodeling in the integrated development of critical systems such as automotive electronics. It distinguishes between lightweight versus heavyweight approaches, surveys a number of related current European projects, and gives details about the Speeds project to illustrate the role of metamodeling-driven system engineering.—Sandeep Shukla, Virginia Tech     

An economic evaluation of photovoltaic grid connected systems (PVGCS) in Flanders for companies: A generic model

In this paper an economic evaluation of photovoltaic grid connected systems (PVGCS) for companies situated in Flanders (Belgium) is conducted by using a generic Excel model. The model is unique in that it includes the dimension of taxation. This inclusion is required, otherwise the fiscal benefit of using solar panels is not accounted for. The model uses the cash flow projection method. This technique allows the calculation of the following classical evaluation criteria: net present value, internal rate of return, payback period, discounted payback period, profitability index, yield unit cost, yield unit revenue and break-even turnkey cost. Their outcome makes it possible to answer the question whether installing a PVGCS in Flanders is a responsible financial investment for companies. Furthermore, the paper estimates whether the corporate environment is ready for a subsidy legislation change. This change has recently been announced and as such it is possible to gauge whether the current market situation is profitable given future legislation.     

How the psychological theory of action identification can offer new advances for research in cognitive engineering

We present the psychological theory of action identification as a framework for a more in-depth understanding of a human operator's cognitive activity in the scope of cognitive engineering. A comparison of theoretical models and findings shows that both frameworks are founded on a similar theory of cognitive control based on an ontological viewpoint of means–ends relationships with the proposal that an individual mentally ‘navigates’ or ‘moves’ through a hierarchical arrangement of these relationships. However, whilst cognitive engineering begins the analysis from a viewpoint on affordances coming from the external work domain, the action identification theory starts from a viewpoint on action identities internally attributed to actions by individuals. We show that the conceptual articulation of these two approaches leads to confirming qualitative findings on an agent's cognitive activity and to proposing general cognitive principles that would explain a single agent's mental navigation through the abstraction hierarchy.     

What attracts and retains knowledge workers/students: The quality of place or career opportunities? The cases of Montreal and Ottawa

The creative class thesis of economic development has been influential in analyzing the mobility of human capital. The thesis has also had a major influence on the orientation of policies in North American cities regarding urban development aspects. Our aim is not to test this thesis of economic development as a whole but rather to use its quality of place criteria to evaluate how students enrolled in science and technology university programs decide where to live upon graduation. Using quantitative and qualitative material, this paper examines the influence of criteria related to quality of place and also to career opportunities concerning the mobility of students in science and technology who will soon be part of the professional category of the knowledge workers. Our hypothesis is that knowledge workers would be much more attracted by urban environments having more potential in terms of creativity, corresponding to the criterion emphasised in the creative class thesis. However, our results suggest that the quality of place is not as important as career opportunities. This does not lead us to refute the relevance of the creative class thesis but to nuance the relevance of various factors of location. It appears that the two cities in our study achieve different results on only one major point: the quality of life of Ottawa is a more powerful criterion of attraction/retention than in Montreal.     

Chemical‐looping combustion process: Kinetics and mathematical modeling

Chemical Looping Combustion technology involves circulating a metal oxide between a fuel zone where methane reacts under anaerobic conditions to produce a concentrated stream of CO₂ and water and an oxygen rich environment where the metal is reoxidized. Although the needs for electrical power generation drive the process to high temperatures, lower temperatures (600–800°C) are sufficient for industrial processes such as refineries. In this paper, we investigate the transient kinetics of NiO carriers in the temperature range of 600 to 900°C in both a fixed bed microreactor (WHSV = 2‐4 g CH₄/h/g oxygen carrier) and a fluid bed reactor (WHSV = 0.014‐0.14 g CH₄/h per g oxygen carrier). Complete methane conversion is achieved in the fluid bed for several minutes. In the microreactor, the methane conversion reaches a maximum after an initial induction period of less than 10 s. Both CO₂ and H₂O yields are highest during this induction period. As the oxygen is consumed, methane conversion drops and both CO and H₂ yields increase, whereas the CO₂ and H₂O concentrations decrease. The kinetics parameter of the gas–solids reactions (reduction of NiO with CH₄, H₂, and CO) together with catalytic reactions (methane reforming, methanation, shift, and gasification) were estimated using experimental data obtained on the fixed bed microreactor. Then, the kinetic expressions were combined with a detailed hydrodynamic model to successfully simulate the comportment of the fluidized bed reactor. © 2010 American Institute of Chemical Engineers AIChE J, 2010     

A New Approach to Assess Gold Nanoparticle Uptake by Mammalian Cells: Combining Optical Dark‐Field and Transmission Electron Microscopy

Toxicological effects of nanoparticles are associated with their internalization into cells. Hence, there is a strong need for techniques revealing the interaction between particles and cells as well as quantifying the uptake at the same time. For that reason, herein optical dark‐field microscopy is used in conjunction with transmission electron microscopy to investigate the uptake of gold nanoparticles into epithelial cells with respect to shape, stabilizing agent, and surface charge. The number of internalized particles is strongly dependent on the stabilizing agent, but not on the particle shape. A test of metabolic activity shows no direct correlation with the number of internalized particles. Therefore, particle properties besides coating and shape are suspected to contribute to the observed toxicity.