Topographical optimisation of single-storey non-domestic steel framed buildings using photovoltaic panels for net-zero carbon impact

A methodology is presented that combines a multi-objective evolutionary algorithm and artificial neural networks to optimise single-storey steel commercial buildings for net-zero carbon impact. Both symmetric and asymmetric geometries are considered in conjunction with regulated, unregulated and embodied carbon. Offsetting is achieved through photovoltaic (PV) panels integrated into the roof. Asymmetric geometries can increase the south facing surface area and consequently allow for improved PV energy production. An exemplar carbon and energy breakdown of a retail unit located in Belfast UK with a south facing PV roof is considered. It was found in most cases that regulated energy offsetting can be achieved with symmetric geometries. However, asymmetric geometries were necessary to account for the unregulated and embodied carbon. For buildings where the volume is large due to high eaves, carbon offsetting became increasingly more difficult, and not possible in certain cases. The use of asymmetric geometries was found to allow for lower embodied energy structures with similar carbon performance to symmetrical structures.

An efficient genetic algorithm for the design optimization of cold-formed steel portal frame buildings

The design optimization of a cold-formed steel portal frame building is considered in this paper. The proposed genetic algorithm (GA) optimizer considers both topology (i.e., frame spacing and pitch) and cross-sectional sizes of the main structural members as the decision variables. Previous GAs in the literature were characterized by poor convergence, including slow progress, that usually results in excessive computation times and/or frequent failure to achieve an optimal or near-optimal solution. This is the main issue addressed in this paper. In an effort to improve the performance of the conventional GA, a niching strategy is presented that is shown to be an effective means of enhancing the dissimilarity of the solutions in each generation of the GA. Thus, population diversity is maintained and premature convergence is reduced significantly. Through benchmark examples, it is shown that the efficient GA proposed generates optimal solutions more consistently. A parametric study was carried out, and the results included. They show significant variation in the optimal topology in terms of pitch and frame spacing for a range of typical column heights. They also show that the optimized design achieved large savings based on the cost of the main structural elements; the inclusion of knee braces at the eaves yield further savings in cost, that are significant.

Advanced design optimization of cold-formed steel portal frame buildings

The design optimization of cold-formed steel portal frame buildings is considered in this paper. The objective function is based on the cost of the members for the main frame and secondary members (i.e., purlins, girts, and cladding for walls and roofs) per unit area on the plan of the building. A real-coded niching genetic algorithm is used to minimize the cost of the frame and secondary members that are designed on the basis of ultimate limit state. It iis shown that the proposed algorithm shows effective and robust capacity in generating the optimal solution, owing to the population's diversity being maintained by applying the niching method. In the optimal design, the cost of purlins and side rails are shown to account for 25% of the total cost; the main frame members account for 27% of the total cost, claddings for the walls and roofs accounted for 27% of the total cost.

Topographical optimisation of single-storey non-domestic steel framed buildings using photovoltaic panels for zero carbon impact

The optimisation is based on a combination of neural networks and evolutionary algorithm. It has selected buildings with different midpoint configurations with zero carbon impacts. With operational energy included the structures could be offset with asymmetry.

Energy and environmental forensic analysis for public buildings.

This paper outlines a forensic method for analysing the energy, environmental and comfort performance of a building. The method has been applied to a recently developed event space in an Irish public building, which was evaluated using on-site field studies, data analysis, building simulation and occupant surveying. The method allows for consideration of both the technological and anthropological aspects of the building in use and for the identification of unsustainable operational practice and emerging problems. The forensic analysis identified energy savings of up to 50%, enabling a more sustainable, lower-energy operational future for the building. The building forensic analysis method presented in this paper is now planned for use in other public and commercial buildings.

Ionic liquid gel materials: applications in green and sustainable chemistry

Ionic liquid gel materials offer a way to further utilise ionic liquids in technological applications. Combining the controlled and directed assembly of gels, with the diverse applications of ionic liquids, enables the design of a heady combination of functional tailored materials, leading to the development of task specific / functional ionic liquid gels. This review introduces gels and gel classification, focusing on ionic liquid gels and their potential roles in a more sustainable future. Ionic liquid gels provide the ability to build functionality at every level, the solid component, the ionic liquid, and any incorporated active functional agents. This allows materials to be custom designed for a vast assortment of applications. This diverse class of materials has the potential to yield functional materials for green and sustainable chemistry, energy, electronics, medicine, food, cosmetics, and more. The discussion of the development of ionic liquid gel materials for applications in green and sustainable chemistry centres on uses of ionic liquid gels in catalysis and energy.

Integrating personality research and animal contest theory:Aggressiveness in the green swordtail xiphophorus helleri

Aggression occurs when individuals compete over limiting resources. While theoretical studies have long placed a strong emphasis on context-specificity of aggression, there is increasing recognition that consistent behavioural differences exist among individuals, and that aggressiveness may be an important component of individual personality. Though empirical studies tend to focus on one aspect or the other, we suggest there is merit in modelling both within- and among-individual variation in agonistic behaviour simultaneously. Here, we demonstrate how this can be achieved using multivariate linear mixed effect models. Using data from repeated mirror trials and dyadic interactions of male green swordtails, Xiphophorus helleri, we show repeatable components of (co)variation in a suite of agonistic behaviour that is broadly consistent with a major axis of variation in aggressiveness. We also show that observed focal behaviour is dependent on opponent effects, which can themselves be repeatable but were more generally found to be context specific. In particular, our models show that within-individual variation in agonistic behaviour is explained, at least in part, by the relative size of a live opponent as predicted by contest theory. Finally, we suggest several additional applications of the multivariate models demonstrated here. These include testing the recently queried functional equivalence of alternative experimental approaches, (e.g., mirror trials, dyadic interaction tests) for assaying individual aggressiveness. © 2011 Wilson et al.

Green Space Attachment and Health: A Comparative Study in Two Urban Neighborhoods

The positive relationships between urban green space and health have been well documented. Little is known, however, about the role of residents’ emotional attachment to local green spaces in these relationships, and how attachment to green spaces and health may be promoted by the availability of accessible and usable green spaces. The present research aimed to examine the links between self-reported health, attachment to green space, and the availability of accessible and usable green spaces. Data were collected via paper-mailed surveys in two neighborhoods (n = 223) of a medium-sized Dutch city in the Netherlands. These neighborhoods differ in the perceived and objectively measured accessibility and usability of green spaces, but are matched in the physically available amount of urban green space, as well as in demographic and socio-economic status, and housing conditions. Four dimensions of green space attachment were identified through confirmatory factor analysis: place dependence, affective attachment, place identity and social bonding. The results show greater attachment to local green space and better self-reported mental health in the neighborhood with higher availability of accessible and usable green spaces. The two neighborhoods did not differ, however, in physical and general health. Structural Equation Modelling confirmed the neighborhood differences in green space attachment and mental health, and also revealed a positive path from green space attachment to mental health. These findings convey the message that we should make green places, instead of green spaces.

Effects of a green tax reform in Portugal: a general equilibrium analysis

Do ponto de vista da política económica, existe a possibilidade de utilizar a receita dos impostos ambientais para baixar os impostos sobre o trabalho, promovendo assim o emprego. Esta oportunidade surge na literatura como forma dos países industrializados responderem a um duplo desafio: um crescente nível de poluição e um decrescente nível de emprego. Alguns países tomaram já decisões no sentido de alcançar o “duplo dividendo”: melhorias ambientais e diminuição do desemprego. Os resultados teóricos, na sua maioria cépticos em relação à verificação do segundo dividendo, são substancialmente contrariados por uma série de estudos que utilizam modelos de equilíbrio geral. Pretendese com este trabalho fazer uma simulação para a economia portuguesa de uma reforma fiscal ambiental com as características referidas e a verificação da existência do “duplo dividendo”, através de um modelo computacional de equilíbrio geral. Para além disso, é feita uma análise dos impactos do Mercado Europeu de Licenças de Emissão, ao nível sectorial e regional, em Portugal, utilizando dados microeconómicos, com o objectivo de estudar as consequências ao nível das trasacções entre sectores e efeitos distributivos entre regiões.