Aalto University

About: Aalto University is a education organization based out in Espoo, Finland. It is known for research contribution in the topics: Population & Carbon nanotube. The organization has 9969 authors who have published 32648 publications receiving 829626 citations. The organization is also known as: TKK & Aalto-korkeakoulu.

Global Sex Differences in Test Score Variability

Abstract: D o boys and girls differ in their intellectual and cognitive abilities and, if so, in what way? These questions have raised considerable debate, both in terms of average performance and in terms of variability around the average. Empirical research on gender differences in achievements produces mixed conclusions, with some evidence that favors boys and some that favors girls (1–4). In many countries, girls show superior performance in school examinations, which is also reflected in higher rates of attendance in tertiary education. In addition, girls have been improving their position relative to boys (5, 6). In countries with a more gender-equal culture, the gender gap that is usually in favor of boys in average mathematics test scores is erased or even reversed in favor of girls (7). At the same time, some research focuses on the notion that there are more males at the upper end of the distributions of educational and professional success (8). Oft-cited examples include there being more male than female Nobel Prize winners and the inequity of wages in the labor market in favor of males (9, 10). Studies of talented individuals who succeed at the very highest levels, especially in science, highlight substantial male overrepresentation (11). These outcomes can be generated by various kinds of distributions describing the educational and intellectual make-up of boys and girls. Differences in the gender composition of the high-scoring group can be a consequence of gender differences in the mean or variance of the test scores or both. Given that recent research has shown that gender

Ioncell-F: A High-strength regenerated cellulose fibre

Abstract: In this paper, we report the development of a novel regenerated cellulose fibre process of the Lyocell type, denoted Ioncell-F. The process is characterized by the use of a powerful direct cellulose solvent, 1,5-diazabicyclo[4.3.0]non-5-enium acetate ([DBNH][OAc]) a superbase-based ionic liquid. Compared with the commercial NMMO-based Lyocell fibre process, airgap spinning can be conducted at higher cellulose concentration in the dope, while temperature during dissolution and spinning can be maintained at a lower level. Owing to the generally milder process conditions, the cellulose is less degraded which contributes to both higher fibre yield and better strength properties. In this study we demonstrated the effect of different cellulose concentrations and draw ratios on the fibre properties. The highest tenacities, consistently above 50 cN/tex, were achieved by spinning from 15 and 17 wt% cellulose solutions. A very high initial modulus of up to 34 GPa makes the Ioncell-F fibres very interesting for technical applications such as a reinforcing fiber in composites. The chain orientation in the fibre direction, particularly in the amorphous regions, revealed the best correlation with the elastic modulus and the tensile strength of the IoncellF fibres, in agreement with other high-tenacity regenerated cellulose fibres as reported in the literature.

Halogen Bonding versus Hydrogen Bonding in Driving Self‐Assembly and Performance of Light‐Responsive Supramolecular Polymers

Abstract: Halogen bonding is arguably the least exploited among the many noncovalent interactions used in dictating molecular self-assembly. However, its directionality renders it unique compared to ubiquitous hydrogen bonding. Here, the role of this directionality in controlling the performance of lightresponsive supramolecular polymers is highlighted. In particular, it is shown that light-induced surface patterning, a unique phenomenon occurring in azobenzene-containing polymers, is more effi cient in halogen-bonded polymer‐azobenzene complexes than in the analogous hydrogen-bonded complexes. A systematic study is performed on a series of azo dyes containing different halogen or hydrogen bonding donor moieties, complexed to poly(4vinylpyridine) backbone. Through single-atom substitution of the bond-donor, control of both the strength and the nature of the noncovalent interaction between the azobenzene units and the polymer backbone is achieved. Importantly, such substitution does not signifi cantly alter the electronic properties of the azobenzene units, hence providing us with unique tools in studying the structure‐performance relationships in the light-induced surface deformation process. The results represent the fi rst demonstration of light-responsive halogen-bonded polymer systems and also highlight the remarkable potential of halogen bonding in fundamental studies of photoresponsive azobenzenecontaining polymers.

Innovation and the Market Value of UK Firms, 1989-1995

Abstract: Using a new data set covering a sample of UK firms, 1989-1995, we study the impact of innovation and innovation assets on firm value. We find, for all reporting firms, that the flow of R&D and the use of new technologies (as measured by investment in tangible assets) have significant positive impacts on market value. A patent count variable is insignificant in cross section estimates, although significant but impacting negatively in panel estimates. A sample of firms reporting their R&D for the first time yields much larger estimates of the impact of R&D on market value than in the sample of all reporting firms.