Compact Facility for Testing Steady and Transient Thermal Performance of Building Walls

Energy efficiency retrofit of buildings represents a key effort in reducing EU energy demand by 20% by 2020. However, predictions tend to overestimate savings by large percentages. The shortfall in savings can be attributed to incorrect predictive techniques, comfort takeback along with other behavioural and workmanship variables. Common predictive techniques related to heat loss tend to be based on the U-value of the building envelope. This paper presents the design of a more straightforward and compact version of the traditional Hot-Box apparatus (measures U-value) which instead determines the thermal resistance of samples of building envelope. U-value includes the need to measure/predict the effective surface resistances. In situ surface resistances, which include radiation and convection, are difficult to predict and vary depending on climatic conditions, exposure levels, surface emissivities among many other influences. The design of the test facility eliminates the need to incorporate these surface behaviour variables. This paper details the replicable apparatus and test methodology. The results of testing a hollow block wall of typical construction using the rig is then presented. The determined R-value is found to be within 1% of calculated values and the thermal time constant also matches closely with the most accurate predictive estimates

Educating engineers to embrace complexity and context

Education represents a key intervention point in encouraging the emergence of a professional engineering ethos informed by a sustainability ethic. In terms of establishing an appropriate relationship between sustainability and education, many would contend that incorporating sustainability as merely add-on material to already overcrowded curricula is insufficient. Instead sustainability should actually be a leading principle for curricula. Traditional reductionist models of engineering education seek to extinguish context and uncertainty and reduce complexity across socio-economic and ecological domains. They therefore constitute a wholly inadequate response to the need for fit-for-purpose, twenty-first century graduates required to address broader sustainability issues. This paper presents research from an undergraduate module at University College Cork, Ireland. The module is aimed at developing students' conceptions of complexity, uncertainty, risk, context and ethics as foundational bases for productively engaging with sustainability. The paper also highlights some problematic issues

Transient and Quasi-Steady Thermal Behaviour of a Building Envelope due to Retrofitted Cavity Wall and Ceiling Insulation

Accurate understanding of the thermal behaviour of building components is essential for predicting heat-ing or cooling needs and facilitates the implementation of more successful energy saving strategies and retrofits. This paper focuses on a specific measure commonly introduced through the residential energy efficiency retrofit programmes in Ireland–insulation. Traditionally, assessments of the performance of building envelopes have been based on assumed thermal resistances of the materials involved, labora-tory tests and computer modelling. The aim of the present work is to investigate the in situ thermal behaviour of a case study building and its components under transient and quasi-steady environmental conditions, comparing data before and after the fixing of cavity wall and ceiling insulation. The paper concludes by proposing that predicted values of heat loss using standardised assumed material prop-erties of the existing structure do not reflect the actual values achieved in situ for this test case. These values greatly overestimated the impact of the retrofitted insulation on heat loss through the ceiling and wall

Propagating an integral and transdisciplinary approach to sustainability education

Recent directions in engineering for sustainable development (EESD) (and in ESD more generally) have pointed towards an increasing realisation that in order to adequately begin to address respective meta-problems associated with global (un)sustainability, ‘object world’ disciplinary perspectives alone are insufficient. Instead, the required depth of knowledge that expert disciplinary knowledge can provide must be both complimented and built upon by other disciplinary as well as experiential knowledge. Integral and transdisciplinary approaches to learning can play a central role in helping achieve this. When such approaches are applied, they facilitate the possibility of new and emergent knowledge and insights which can transcend disciplinary bounds, with the potential to reach places where no single disciplinary approach can; a classic case of ‘whole greater than the sum of parts’. This however requires a degree of disciplinary humility and openness to other approaches and disciplinary norms, as well as a degree of trust, patience and time. Nevertheless, in the context of seeking authentic sustainability, it is necessary. The classical engineering degree structure is not amenable to this approach. Engineering has traditionally seen itself as a ‘problem solving profession only insofar as ‘problems’, including complex socio-technological ones (with ecological and economic import) can be neatly reduced to well-defined closed system decontextualized ‘puzzles’ which can then be algorithmically optimised. This is deeply problematic as it cannot map reality; specifically, complex contemporary 21st century reality, instead resulting in emergent ‘unintended consequences’. A key intervention point therefore in the development of a fit-for-purpose cohort of engineering graduates capable of addressing emergent twenty first century meta-problems is through their formative education. Here integral and transdisciplinary approaches to sustainability education/ESD offer a useful approach. But this requires not just the inclusion of ‘sustainable development material’, but a perpendicular reconceptualization of pedagogical approaches. This approach coheres with contemporary pedagogical best practice as it privileges relational and constructivist approaches to learning over the traditional atomistic approach, incorporating as it does, peer to peer and personal reflective learning opportunities. This paper reflects on the experiences of a programme where undergraduate chemical engineering students undertaking a sustainability module collaborate with students on an analogous sociology module. It describes how this transdisciplinary collaboration takes an integral approach to sustainability learning, incorporating both subjective and objective perspectives as well as inter-subjective and inter-objective. The work reflects on how this initiative worked by drawing on student feedback and the authors’ experiences

Total internal reflection microscopy studies on colloidal particle endocytosis by living cells

The purpose of this study was to develop novel optical microscopy techniques in order to investigate colloidal drug particle endocytosis by mammalian cells. A total internal reflection microscope (TIRM) was initially developed for high resolution cellular imaging. TIRM is a non-fluorescent imaging technique based on the principle of ‘scattering’ of the evanescent field created when a light beam undergoes total internal reflection at an interface between two media with different refractive indices, such as glass and air. The key design considerations with respect to development of a TIRM instrument are discussed. The technique is also compared and contrasted to the more commonly known non-fluorescent RICM (Reflection Interference Contrast Microscopy) technique using computer simulations. Time-lapse video TIRM is applied to imaging the interaction between A549 and 3T3 cells, and a polylysine coated substrate. Real-time label-free visualisation of 0.5 and 1 m polystyrene particle endocytosis by living cells is then demonstrated. Modifications to the TIRM system to include a dual-colour fluorescent TIRF (Total Internal Reflection Fluorescence) microscope are described in detail. Results are shown which demonstrate the ability of a combined TIRM/TIRF instrument to selectively image the basal cell membrane both label-free and fluorescently. 3T3 fibroblast cells were genetically modified using standard molecular biology protocols to express the fluorescent fusion protein EGFP-Clathrin LCa (enhanced green fluorescent protein clathrin light chain a). Finally, colloidal particle endocytosis by the genetically modified cell was imaged using the TIRM/TIRF microscope. Direct visualisation of the internalisation of 500 nm particles via clathrin coated pits in 3T3 cells was shown for the first time

Growth and production of lipase by rhizopus arrhizus in submerged culture

In this project the physiology and growth of Rhizopus arrhizus was investigated in detail with a view to developing an industrial fermentation process to produce a lipase enzyme. Spore and vegetative inocula were examined and biomass production was optimized in flasks and fermenters. Pelleting of growth was controlled by developing suitable inoculum procedures and media. Storage conditions for stock cultures were optimized also as part of this work. Factors affecting lipase production were investigated initially m shake-flasks, and later in stirred laboratory fermenters. The inoculum development and production fermentations were then integrated and scaled-up to plant-scale (3,000 litres). Economic yields of lipase were obtained at this scale. Other experiments were conducted to determine the biochemical characteristics of several lipase enzymes and to develop a rapid and inexpensive lipase assay. Finally, growth morphology of R. arrhizus was examined m a range of media to investigate some possible causes and mechanisms associated with pelleting of growth

Treatment of specific phobia in older adults

Phobias are common in later life, yet treatment research in this population remains scant. The efficacy of exposure therapy, in combination with other Cognitive-Behavioral Therapy (CBT) components, in the treatment of specific phobia with a middle and older aged sample was examined. Sixteen adults aged 45–68 with DSM-IV diagnosis of a specific phobia received a manualized intervention over ten weeks, and were compared with a control group. Results indicated significant time effects in the treatment group for the primary outcome variables of phobic severity and avoidance as well as secondary outcome variables including depression and anxiety. Symptom presence and severity also significantly declined in the treatment group. No significant changes in state anxiety were noted across the treatment period. Such results provide support for the efficacy of exposure combined with CBT treatment for specific phobia in middle to older aged adults