Alaster Yoxall

Food for Thought? — A UK pilot study testing a methodology for compositional domestic food waste analysis

Recent media attention has amply demonstrated the need for changes in our society regarding waste. The cost of waste is rising, European legislation is driving forward waste reduction policies and industry is being made responsible for the waste that all products make. This legislation is also driving a reduction in biodegradable municipal waste. In general there are a number of factors ranging from the media, financial and political to environmental, that are driving forward an agenda to decrease both general waste and food waste going to landfill. A necessary requirement of such an agenda is a benchmark of the current composition and scale of both general waste and food waste. Hence, this can then be used as a measure to demonstrate improvement. A measurement methodology and the benchmark data already exists for general waste. However, there is little or no previous work about the compositional make up of food waste. This paper discusses the necessity for a compositional food waste analysis and the pros and cons of various food waste measurement methodologies. Results for a specific methodology are illustrated and suggestions for a revision of this methodology are proposed.

Bayesian sensitivity analysis of a model of the aortic valve.

Understanding the mechanics of the aortic valve has been a focus of attention for many years in the biomechanics literature, with the aim of improving the longevity of prosthetic replacements. Finite element models have been extensively used to investigate stresses and deformations in the valve in considerable detail. However, the effect of uncertainties in loading, material properties and model dimensions has remained uninvestigated. This paper presents a formal statistical consideration of a selected set of uncertainties on a fluid-driven finite element model of the aortic valve and examines the magnitudes of the resulting output uncertainties. Furthermore, the importance of each parameter is investigated by means of a global sensitivity analysis. To reduce computational cost, a Bayesian emulator-based approach is adopted whereby a Gaussian process is fitted to a small set of training data and then used to infer detailed sensitivity analysis information. From the set of uncertain parameters considered, it was found that output standard deviations were as high as 44% of the mean. It was also found that the material properties of the sinus and aorta were considerably more important in determining leaflet stress than the material properties of the leaflets themselves.

The use of uncertainty analysis as a food waste estimation tool

Food waste going to landfill is a significant environmental issue with 33% of all food we buy simply being thrown away. Not only is this extremely wasteful but rotting food produces gases that are harmful to the environment and contributes to global warming. The UK government is committed to reducing the amount of household waste directly being disposed of at landfills by 10.1 million tonnes tonnes over 20 years from 2000 (Waste Composition Analysis: Guidance for Local Authorities, Defra, 2004). As part of this the Waste Reduction Action Programme was set up to fund and facilitate innovative solutions to reduce waste to landfill. Part of that process was to assess bids by solution providers with regards the effectiveness of the technologies that they were offering. This was found to be a non-trivial task, with multiple input parameters and large variations in data. Establishing which parameters have the greatest effect on food waste estimation was therefore essential in any decision-making process. However, the large number of unknowns, assumptions and parameters makes this understanding both difficult and time consuming. A branch of mathematics known as uncertainty analysis can be used to analyse these types of situations quickly and effectively and is easily adapted to understanding of food waste estimation. This paper outlines the techniques used to develop an internet-based decision-making tool and demonstrates the methodology used with simple case studies.

Of mice and men : the role of interactive exhibitions as research tools for inclusive design

ABSTRACT The Exhibition is embedded within the culture of Art and Design and has a long history as a form of ‘gathering’ to prompt academic discourse. This paper explores the role of the exhibition as a theatre for conversation that has parallels with the salon gatherings that emerged in mid-seventeenth-century France. This paper will describe ‘The Future Bathroom’ – a project that contributes to the development of methods and tools to support an inclusive design agenda. The bathroom provides a number of challenges to user-centred design methodology because of the highly personal, sensitive and intimate nature of the activities that take place there. Various methods were adopted during the course of the enquiry and here we focus on the role of the interactive exhibition as a research tool to gather data and further our understanding within the context of the research objectives. As part of the interdisciplinary research network ‘Engineering for Life’ (supported through the Engineering and Physical Sciences Research Council (EPSRC) Bridging the Gap Programme), researchers within the Art and Design Research Centre (ADRC) at Sheffield Hallam University explored the potential of a ‘field lab’ exhibition based on the ‘future bathroom’ research to both gather and disseminate knowledge.

Husband, daughter, son and postman, hot-water, knife and towel: Assistive Strategies for Jar Opening

Society is ageing and this demographic shift creates significant hurdles for designers, engineers, manufacturers and health practitioners. Not least is the development of a society where the majority of people will have some issues related to a loss of strength, dexterity and, possibly, locomotion, sight and cognition. Public acknowledgement of people with disabilities has changed significantly over recent years with three parallel drivers: legislation such as the Disability Discrimination Act (1995), advances in assistive technology and rehabilitation and lastly the understanding in the design community of the need for a change in the way products are designed. With this change in demographics it is assumed that the elderly will become drivers for change, demanding changes in infrastructure, products and services. Of particular interest in the design community has been the development of a concept called ‘Inclusive’ or ‘Universal’ design, promoted by various organisations, notably the Royal College of Art, in the UK. The British Standards Institute (BSi, 2005) defines inclusive design as “The design of mainstream products and/or services that are accessible to, and usable by, as many people as reasonably possible....without the need for special adaptation.”

Comparison of numerical and ultrasonic techniques for quantifying interference fit pressures

Press fits are commonly used in manufactured assemblies, components, and machines. For example railway wheels are press or shrink fitted onto axles. Railway axles occasionally fail by fatigue resulting from the alternating rotating bending loading. The site of the fatigue crack initiation is commonly at the location of the press fit. Therefore, a good understanding is needed of the press-fit region, particularly where stress-raising effects are caused by, for example, large changes in geometry. Analytical techniques are unable to predict stresses in these areas. In this work, an ultrasonic technique was used to measure the contact stresses in a real shaft—sleeve contact. The results were compared with finite-element models of the same components. The results from the two techniques compared well both in the centre of the fit and around the edges where the stresses were raised. Both showed good correlation with the analytical Lamé solution away from the edges. The two techniques could therefore be combined in a design tool to help remove problems with edge effects that could lead to mechanical failures.

Squeezability. Part 2: Getting stuff out of a bottle

Abstract Western Europe, the USA, and Japan are experiencing rapidly ageing societies. That ageing brings with it a host of issues, not least a society in which a large proportion is likely to have relative difficulties with strength, dexterity, and cognition. One specific area that stimulates a significant amount of controversy is the accessibility and functionality of product packaging. Newspapers and television frequently report on consumer frustration with regard to ‘over’ packaged or poorly accessible goods. In response, researchers, designers, brand-owners, and manufacturers have been undertaking significant work to address these concerns. Developments in ‘easy to open’ packaging are all around. However, the question remains ‘how easy is easy?’ In a previous study, the authors used analytical and experimental techniques to look at accessibility of the contents of ‘squeezy’ bottles; bottles that have, in essence, been specifically designed to improve physical access to the product. This work demonstrated that ease of access is affected by a complex combination of several factors, not least of these are bottle stiffness, shape, and orifice type. This article outlines a continuation of this study, using thin-film force sensors to study grip forces applied when squeezing a bottle and assessing how that force changes with gender and age. The article goes further to derive what the authors term bottle ‘efficiency’ and illustrates that this varies significantly with the bottle design.

Service learning experiences: a way forward in teaching engineering students?

Abstract Engineering education in the UK has slowly begun to understand the benefits of service learning, in which students take part in a community project as part of their course. The Department of Mechanical Engineering at the University of Sheffield has explored service learning for the past three years. This paper looks at the use of service learning in an engineering environment in terms of embedding social awareness into the curriculum and looks at the issues surrounding the engagement of engineering students. It discusses problems which cause barriers to successful implementation as well as how service learning can inspire the next generation of engineers and change the perception of engineering in the community.

Squeezability. Part 1: a pressing issue

Abstract Within the UK it is estimated that by 2020 over half the adult population will be over 50. A society in which the majority are aged poses some interesting questions, not least how that society will use and access goods and services, when the majority are likely to experience some loss of strength and dexterity. One such issue, the openability or accessibility of packaging, is becoming a major issue for brand owners, manufacturers, designers, and engineers due to the rapid ageing of much of the developed world. The authors have previously undertaken a significant amount of work on understanding the openability of vacuum lug closures (jam or sauce jars). This work looked at the forces to keep the system closed, the forces a human could apply and used experimental, numerical, and analytical analysis to understand these systems. Packaging, however, comes in many varied and differing forms and little or no previous work has been undertaken in this field on other forms of packaging such as thin film packets or bottles. The work in this article applies the principles used in the earlier studies to the squeezable bottle pack format. The article describes initial experimental and analytical work undertaken from first principals to establish the factors that contribute to the ease of use along with various laboratory tests carried out in order to determine the design rules for developing bottle styles and nozzle designs, for specific fluid contents. The work suggested several things that may be important for designers and manufacturers of squeezable bottles. Fundamental analysis shows that bottle material and shape generally dominate the squeezeability of and access to bottle contents. Bottle shape was seen to affect performance with the conditioner bottle having the best volume—deflection performance. Work also showed that hole size and Borda length can be calculated to determine specific flow characteristics with a relatively simple set of equations.

Analyzing finger interdependencies during the Purdue Pegboard Test and comparative activities of daily living

Study Design: Bench and cross‐sectional study. Introduction: Information obtained from dexterity tests is an important component of a comprehensive examination of the hand. Purpose of the Study: To analyze and compare finger interdependencies during the performance of the Purdue Pegboard Test (PBT) and comparative daily tasks. Methods: A method based on the optoelectronic kinematic analysis of the precision grip style and on the calculation of cross‐correlation coefficients between relevant joint angles, which provided measures of the degree of finger coordination, was conducted on 10 healthy participants performing the PBT and 2 comparative daily living tasks. Results: Daily tasks showed identifiable interdependencies patterns between the metacarpophalangeal joints of the fingers involved in the grip. Tasks related to activities of daily living resulted in significantly higher cross‐correlation coefficients across subjects and movements during the formation and manipulation phases of the tasks (0.7–0.9), whereas the release stage produced significantly lower movement correlation values (0.3–0.7). Contrarily, the formation and manipulation stages of the PBT showed low finger correlation across most subjects (0.2–0.6), whereas the release stage resulted in the highest values for all relevant movements (0.65–0.9). Discussion: Interdependencies patterns were consistent for the activities of daily living but differ from the patterns observed from the PBT. Conclusions: The PBT does not compare well with the whole range of finger movements that account for hand performance during daily tasks. Level of evidence: Not applicable.