A mathematical model, implementation and study of a swarm system

The work reported in this paper is motivated towards the development of a mathematical model for swarm systems based on macroscopic primitives. A pattern formation and transformation model is proposed. The pattern transformation model comprises two general methods for pattern transformation, namely a macroscopic transformation method and a mathematical transformation method. The problem of transformation is formally expressed and four special cases of transformation are considered. Simulations to confirm the feasibility of the proposed models and transformation methods are presented. Comparison between the two transformation methods is also reported.

Prospects and challenges for sustainable management of the mango stone weevil, Sternochetus mangiferae (F.) (Coleoptera: Curculionidae) in West Africa: a review

Commercial mango production in Ghana is a relatively young industry faced with several pest problems including the mango stone weevil, Sternochetus mangiferae (F.). There is an urgent need to control this and other pests to facilitate access to the international export market for fresh mango fruits. A literature survey identifies stone weevil control tactics in the areas of host plant resistance, administrative and legislative controls, use of pesticides, biological control, cultural control and quarantine and phytosanitary measures that have been developed in other mango-producing areas. We assess these pest management approaches for their relevance to Ghana and West Africa, with emphasis on the research required for their appropriate, effective and sustainable use in the systems of mango production of the West African sub-region. The importance of processing and value addition technologies, as a means of circumventing the quarantine hurdles of S. mangiferae, is highlighted.

Barriers and commitment of facilities management profession to the sustainability agenda

The practice of sustainable facilities management (FM) is rapidly evolving with the increasing interest in the discourse of sustainable development. This paper examines a recent survey of the experiences of facilities managers in the rapidly growing and evolving industry in regard to the barriers and their commitment to the sustainability agenda. The survey results show that time constraints, lack of knowledge and lack of senior management commitment are the main barriers for the implementation of consistent and comprehensive sustainable FM policy and practice. The paper concludes that the diversity of the FM role and the traditional undervaluation of the contribution it makes to the success of organisations are partially responsible for lack of success in achieving sustainable facilities. The overwhelming barrier for sustainable FM practice is the lack of understanding, focus and commitment of senior executives in appreciating the opportunities, threats and need for strategic leadership and direction in driving essential change, and hence further the sustainability agenda.

Evaluation of dichroic material for enhancing light pipe/natural ventilation and daylighting in an integrated system

Integration of natural ventilation and daylighting in a single installation would make both technologies more attractive. One method for the integration is the use of concentric light pipe and ventilation stack. By constructing the light pipe using dichroic materials, the infrared part of the solar radiation is allowed to be transmitted to the stack but the visible light is guided by the light pipe into a room. The heat gain to the interior can be reduced and the thermal stack effect strengthened. Work presented here involved the experimental and computational evaluation of dichroic materials for enhancing both natural stack ventilation and daylighting. The transmittance of a dichroic light pipe was found to be similar to that of a light pipe with a 95% specular reflectance. The infra-red radiation transmitted through the dichroic material into a passive stack was found to enhance the natural ventilation flow by up to 14%. The effect is greater in summer than in winter, which is highly desirable as there is often a lack of driving force for natural stack ventilation in summer.