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THERE has recently been a marked tendency in aviation petrol specifications (particularly in the U.S.A.) to demand fuels of increasing volatility. The idea behind this is that the higher the volatility the better the distribution of the fuel and, therefore, the more uniform the mixture delivered to the various cylinders wjll be.

THE fact that the anti‐knock rating of aviation fuels in octane numbers presents difficulties, especially above 80 octane, has led us to develop a more suitable test method for aviation fuels, which might be called the “Allowable Boost Ratio ” method.

THE problem of undercarriage retraction has now been completely solved, and difficulties may occur only when the wheel has to be stowed flat under the wing as the motion generally requires a rotation about the centre line of the shock absorber.

THE original work of Mr. H. R. Ricardo in 1919 showed some of the technical advantages of using fuels of high anti‐knock value. Since this time the development of aero‐engines in respect of power output and economy has depended more upon the fuels available than upon any other factor. Considerable progress has been made in the direction of improving the anti‐knock value of petroleum spirits, which constitute the bulk of the fuel used in aviation throughout the world. However, until very recently this progress had not been very rapid, and as Mr. Ricardo showed, far greater improvements in anti‐knock value could be achieved by the use of other fuels such as benzol, toluol and alcohol. On the octane scale benzol and toluol have a blending value by the C.F.R. motor method of about 90 in concentrations up to 50 per cent; that of alcohol being about 105. This is shown in Fig. 1, from which it will be observed that two curves are given for ethyl alcohol, one being obtained under motor method conditions (mixture temperature 149 deg. C.) and the other with the same heat input as required for a normal aviation gasoline. By this means the additional advantage of the higher latent heat of the alcohol blends is shown. Neither benzol, toluol nor alcohol is produced in very large quantities, and moreover, in times of national emergency they are likely to be required for purposes other than for use as aviation fuels.

The purpose of this paper is to re-open a debate as to whether candidates for public leadership should be screened for psychopathy.

This is a conceptual paper which examines the diffuse literature concerning psychopaths in public leadership positions.

Psychopathy researchers have been divided as to whether psychopathic individuals should be screened out of leadership positions in public and corporate life. Recent evidence from bullying research and historical research into psychopaths in politics sheds new light on this issue.

There is increasing evidence that psychopaths are detrimental to the organisations they work for, to other employees, to the environment and to society. Screening for psychopathy should therefore be considered. This may help to prevent governments entering into illegal wars and committing crimes against humanity. Screening in the corporate sector may also help prevent the worst excesses of greed and fraud that were evident in collapses like Enron and the Mirror Group as well as in the events leading up to the global financial crisis of 2008.

The paper makes a contribution to the literature on public leadership by bringing together the diverse reports on the effects of psychopaths in public organisations like the National Health Service, publicly listed corporations, academia and politics. The paper uses historical and corporate examples to illustrate the initially favourable impression that psychopathic leaders can make but the ultimately disastrous outcomes they engender.

This paper aims to extend the understanding of the ways in which social entrepreneurs give sense to and legitimize their work by introducing a rhetoric-orientation view of social entrepreneurship (SE).

This study uses computer-aided text analysis and computational linguistics to study 191 interviews of social and business entrepreneurs. It offers validation and exploration of new concepts pertaining to the rhetoric orientations of SE.

This study confirms prior untested assumptions that the rhetoric of social entrepreneurs is more other, stakeholder engagement and justification-oriented and less self-oriented than the rhetoric of business entrepreneurs. It also confirms that the rhetoric of both types of entrepreneurs is equally economically oriented.

This research makes new contribution to the SE literature by introducing three new orientations, namely, solution, impact and geographical, which reflect distinctive rhetorical themes used by social entrepreneurs, and by revealing that social entrepreneurs use terms associated with other, stakeholder engagement, justification, economic, solution, impact and geographical orientations differently than business entrepreneurs.

This paper aims to present an iterative approach to creating a collaborative design-and-play skatepark videogame for a children’s museum physics exhibit. Intended for children of 5-8 years old and accompanying adults, this interactive tabletop game encourages players to build a skatepark and then skate through it with a skater character. This case study describes the authors’ design perspective shift to make the game’s possibilities for tinkering more “perceptible.”

This paper presents a case-based design narrative that draws on the project’s iterative playability testing with parent–child dyads and reflections from the design team’s endeavors. This analysis draws on methodological elements adapted from agile game development processes and educational design-based research.

The initial game prototype inhibited the collaborative tinkering of parent–child dyads because it used interface abstractions such as menus, did not orient to the task of tinkering with skatepark design and did not help players understand why their skatepark designs failed. Subsequent game versions adopted blocks as a metaphor for interaction, gave players explicit design goals and models and provided players with more explicit feedback about their skater’s motion.

Museum games that provide tinkering experiences for children are an emerging medium. Central concerns for those designing such games are presenting multiple modes of play for different players and contexts and clearly and quickly communicating the possible activities and interactions. The design approach in this study offers players the opportunity to – at both short and long timescales – take up game-directed challenges or explore the skatepark physics through self-generated goals.

With the increasing spread of ontologies in various domains, units have gradually become an essential part of ontologies and units ontologies have been developed to offer a better expression ability for the practical usage. From the perspectives of architecture, comparison and reuse, the purpose of this paper is to provide a comprehensive survey on four mainstream units ontologies: quantity-unit-dimension-type, quantities, units, dimensions and values, ontology of units of measure and units ontology (UO) of the open biomedical ontologies, in order to address well the state of the art and the reuse strategies of the UO.

An architecture of units ontologies is presented, in which the relations between key factors (i.e. units of measure, quantity and dimension) are discussed. The criteria for comparing units ontologies are developed from the perspectives of organizational structure, pattern design and application scenario. Then, the authors compare four typical units ontologies based on the proposed comparison criteria. Furthermore, how to reuse these units ontologies is discussed in materials science domain by utilizing two reuse strategies of partial reference and complete reference.

Units ontologies have attracted high attention in the scientific domain. Based on the comparison of four popular units ontologies, this paper finds that different units ontologies have different design features from the perspectives of basis structure, units conversion and axioms design; a UO is better to be applied to the application areas that satisfy its design features; and many challenges remain to be done in the future research of the UO.

This paper makes an extensive review on units ontologies, by defining the comparison criteria and discussing the reuse strategies in the materials domain. Based on this investigation, guidelines are summarized for the selection and reuse of units ontologies.

The purpose of this paper is to develop energy optimizer (ENEO) – a model‐based decision support system (DSS) for an existing European chemical plant with a multi‐stage continuous production process. The system comprises two modules – energy cost minimization and joined energy cost minimization and output maximization. Following the description of the researched production, the paper presents a gist of the underlying formulations. Then, it tests the DSS on real data instances with a focus on its configuration, practical implications and implementation challenges.

The design of the planning tool is consistent with that of the model‐based DSS and based on the existing information systems. The defined research problems are explored with the use of quantitative methods – the operations research methodology.

The findings show that ENEO reflects the essence of the researched production process and can provide benefits in practical business operations.

Both the proposed system configuration and the formulated models lay a foundation to further research within the described industrial setting.

The system can be utilized in daily operations to provide substantial cost savings, improved capacity utilization and reactivity.

This paper contributes to research by bridging the gap between theory and practice. On the one hand, it describes an unexplored problem and its subsequent solution embodied in the DSS. On the other hand, it emphasizes the importance of applying the operations research methodology to the real‐world issues. Therefore, this work is valuable to both academics and practitioners.

Engagement, motivation, and persistence are usually associated with positive outcomes. However, too much of it can overtax our psychophysiological system and put it at risk. On the basis of a neuro-dynamic personality and self-regulation model, we explain the neurobehavioral mechanisms presumably underlying engagement and how engagement, when overtaxing the individual, becomes automatically inhibited for reasons of protection. We explain how different intensities and patterns of engagement may relate to personality traits such as Self-directedness, Conscientiousness, Drive for Reward, and Absorption, which we conceive of as functions or strategies of adaptive neurobehavioral systems. We describe how protective inhibitions and personality traits contribute to phenomena such as disengagement and increased effort-sense in chronic fatigue conditions, which often affect professions involving high socio-emotional interactions. By doing so we adduce evidence on hemispheric asymmetry of motivation, neuromodulation by dopamine, self-determination, task engagement, and physiological disengagement. Not least, we discuss educational implications of our model.