No description available.

No description available.

No description available.

No description available.

The ability to accurately predict object weight is essential for skilled manipulation and recent studies suggest that such prediction is based, in part, on learned size-weight maps associated with families of objects. Weight prediction based on size-weight maps is also involved when judging weights; there is strong evidence that weight judgments are biased by expected weight, based on size. This bias is revealed by the size-weight illusion (SWI) whereby the smaller of two equally weighted and otherwise similar objects is judged to be heavier because it is heavier than expected based on its size. The overall aim of the current set of studies was to examine how size-weight maps for different families of objects are organized and represented at the perceptual and sensorimotor levels. We found that distinct and independent size-weight maps, used to predict weight, were used when lifting objects and judging their weights. At the perceptual level, interference between size-weight maps for the different sets of cubes was observed; participants could learn the inverted size-weight relationship for the green cubes when experienced alone but not when experienced along with the black cubes with a normal size-weight relationship. However, about half of participants learned to scale lift forces accurately for both sets of cubes indicating that the sensorimotor system can learn, without interference, opposite size-weight maps. We further investigated why not all participants learned to accurately scale their lift forces and found that learning to lift objects with different and arbitrary size weight maps involves visuomotor working memory resources. Moreover, an outside task that steals attentional resources can interfere even after previous learning of the size-weight maps. / Thesis (Master, Psychology) -- Queen's University, 2011-09-30 12:51:49.413

The heterogeneous metallocene catalyst is becoming a very competitive industrially due to its ability to produce tailor-made polymers. The main advantage of the metallocene polymer product is the narrow molecular weight distribution (MWD) and the systematic comonomer distribution along the polymer chains. Therefore, the metallocene polymer product has well-defined mechanical and optical properties. The aim of this thesis is to investigate the effects of the silica support on the reaction kinetics and micro properties of the heterogeneous metallocene catalyst system. These investigations include studying the influence of the pore volume, surface area, particle size distribution, and the surface chemical characteristics of silica support on the catalyst performance. The experiments showed that the silica type has an influence on the kinetic behavior. For instance, silica with a lower pore volume shows an induction period when compared with higher pore volume silicas. Moreover, the silica type has a clear influence on catalyst activity and polymer morphology. The smallest silica particles produced the highest activity among the other sizes regardless of silica type. The supported catalysts were characterized and linked to the silica type and size in terms of catalyst activity and polymer morphology. Each catalyst in terms of silica type behaved similarly regardless of type of alkylaluminum used in the formulation. The micro properties of the produced polymers, such as MWD and chemical composition distribution (CCD), were studied to understand the effects of the type and size of silica support and co-catalyst on these properties. The silica types showed no effect on the MWD, but had a slight effect on the CCD. Silica with a high pore volume had a stronger more comonomer response. However, the silica particle size had an influence on the CCD, with less comonomer incorporation observed with smaller silica particles. Finally, triethylauminum was observed to produce polymer with a different MWD when compared with other alkylaluminums. However, all alkylaluminums used in this work had no effect on the CCD of the produced polymer regardless of silica type. / Thesis (Master, Chemical Engineering) -- Queen's University, 2012-04-11 13:37:09.878

No description available.

The research analyzes the bridge load stress effects resulting from international bridge formulae and truck size and weight regulations in Europe. This is done with a view to identifying issues that may need to be considered in the development of a European Bridge Formula (EUBF) conforming to European Directive truck configurations for the regulation of truck size and weight limits associated with international travel between European Union (EU) member states. The level of efficiency of bridge formulae vary depending on the design criteria used in the development of the formula, the compatibility to the jurisdiction’s infrastructure and truck fleet characteristics, and the method of implementation as part of the regulation and by operators in the trucking industry. The EUBF should limit imposed critical bending moment and shear stresses on single and continuous span bridges of varying lengths (5, 20, and 50 metres) in accordance to design live loads specified in the Eurocode. The analysis of bridge load effects imposed by European Directive truck configurations in this research, provide the basis for the development of a EUBF.

No description available.

This thesis examined the validity of allometric models (Y = aXbg) in scaling physiological and human performance data (Y) for differences in body size (X). 1) Anaerobic performance. External peak power output (PPO) derived from supramaximalleg ergometry was compared in young adult males and females, using a multivariate allometric model. Estimated fat free mass (FFM) and thigh muscle-and-bone cross-sectional area served as indicators of involved musculature. Male PPO was greater than female (P < 0.05), after allometric adjustment for body size differences. This finding is questionable, however, as the within-gender goodness-of-fit values for the regression models were very poor. 2) Cardiac dimensions. The proper relationships between echocardiographic dimensions [left ventricular (LV) mass, and LV internal dimensions] and various indicators of overall body size [height, body mass (BM), FFM, and body surface area (BSA)] were examined in young, apparently healthy, adult males and females. Scaling by FFM was associated with the least residual error in these samples. The obtained relationships were generally dimensionally consistent, that is, LV mass proportional to FFM to the first power, and LV internal dimensions related to the 1/3 power ofFFM. 3) Methodological issues. The multivariate allometric scaling of peak oxygen uptake by height and BM was investigated. Regression diagnostics revealed that the obtained exponents were unstable, and potentially numerically inaccurate, due to severe collinearity between height and BM in the sample. For elite weightlifting performance, detailed examination of the allometric regression residuals revealed that the model was poorly specified. Re-specification of the model using secondorder polynomials provided the optimal scaling of this data set.