Representational momentum for a spiral path.

When a ball is shot through a spiral tube at high speed, the ball emerges in a straight path tangent to the ball's point of departure from the tube. However, past research has shown that many Ss believe the ball follows a curved pathway. In the 3 experiments described in this article, a ball traveling through a spiral tube was animated on a computer graphics screen. Ss' memory distortions for positions of the ball along each of 3 pathways were measured using a representational momentum paradigm. Retention interval was varied across the 3 experiments. The results from the 3 experiments reported here replicate retention interval results previously reported for representational momentum effects, and they suggest that the representational pathway of a ball exiting a spiral tube is spiral in shape. These findings may shed some light on why people have demonstrated naiveté on the spiral tube problem in past research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Assessing ventilation systems in hot building environments

The minimisation of energy and operating costs, together with the optimisation of comfort levels must be the aim of any air-conditioning plant. Industrial buildings offer much scope for improvements in the effective operation of air conditioning and ventilation systems. A method of determining the effectiveness of such systems is described—‘Thermal Efficacy’. This allows the assessment of total heat removal in hot industrial environments. Summarized results of tests carried out in a synthetic-fibre producing factory are presented. Advantages of using Thermal Efficacy include improved assessment of discomfort levels experienced by workers.     

How do argumentation diagrams compare when student pairs use them as a means for debate or as a tool for representing debate?

The objective of the research presented here was to study the influence of two types of instruction for using an argumentation diagram during pedagogical debates over the Internet. In particular, we studied how using an argumentation diagram as a medium of debate compared to using an argumentation diagram as a way of representing a debate. Two groups of students produced an individual argument diagram, then debated in pairs in one of the two conditions, and finally revised their individual diagrams in light of their debate. We developed an original analysis method (ADAM) to evaluate the differences between the argumentation diagrams constructed collaboratively during the interactions that constituted the experimental conditions, as well as those constructed individually before and after debate. The results suggest a complementary relationship between the usage of argumentation diagrams in the framework of conceptual learning. First, students who were instructed to use the argumentation diagram to represent their debate were less inclined to take a position in relation to the same graphical element while collaborating. On the other hand, students who were instructed to use the argumentation diagram alongside a chat expressed more personal opinions while collaborating. Second, the instructions given to the participants regarding the use of the argumentation diagram during the collaborative phase (either for debate or for representing a chat debate) have a significant impact on the post-individual graphs. In the individual graphs revised after the collaborative phase, participants who used the graph to represent their debate added more examples, consequences and causes. It follows that a specific usage for an argumentation diagram can be chosen and instructions given based on pedagogical objectives for a given learning situation.     

Non-destructive and contactless defect detection inside leading edge coatings for wind turbine blades using mid-infrared optical coherence tomography

Leading edge erosion of wind turbine blades is one of the most critical issues in wind energy production, resulting in lower efficiency, as well as increased maintenance costs and downtime. Erosion is initiated by impacts from rain droplets and other atmospheric particles, so to protect the blades, special protective coatings are applied to increase their lifetime without adding significantly to the weight or friction of the blade. These coatings should ideally absorb and distribute the force away from the point of impact; however, microscopic defects, such as bubbles, reduce the mechanical performance of the coating, leading to cracks and eventually erosion. In this work, mid-infrared (MIR) Optical Coherence Tomography (OCT) is investigated for non-destructive, contactless inspection of coated glass-fiber composite samples to identify subsurface coating defects. The samples were tested using rubber projectiles to simulate rain droplet and particle impacts. The samples were subsequently imaged using OCT, optical microscopy, and X-ray tomography. OCT scanning revealed both bubbles and cracks below the surface, which would not have been detected using ultrasonic or similar non-destructive methods. In this way, OCT can complement the existing quality control in turbine blade manufacturing, help improve the blade lifetime, and reduce the environmental impact from erosion.     

A question to the physician from a patient on hemodialysis: Would it be safe to run a marathon? A case report

A patient on maintenance hemodialysis asked his physician if it would be safe for him to run a marathon. For healthy persons, studies show that it is relatively safe. Very few data are available on patients on hemodialysis performing out of center endurance exercise. To address this question, we conducted a clinical study to investigate the electrolyte derangements during different running distances. Our main concern was development of hyperkalemia. We present a case of an anuric hemodialysis patient, who ran eight different runs with a maximum distance of 32.2 km. Blood was analyzed before and after the runs. We did not find severe hyperkalemia at any point. According to this study, we found no signs of increased risk.