An investigation of the grindability of two torrefied energy crops

The process of torrefaction alters the physical properties of biomass, reducing its fibrous tenacious nature. This could allow increased rates of co-milling and therefore co-firing in coal fired power stations, which in turn would enable a reduction in the amount of coal used and an increase in the use of sustainable fuels, without the need for additional plant. This paper presents an experimental investigation of the pulverisation behaviour of two torrefied energy crops, namely: willow and Miscanthus. A multifactorial method approach was adopted to investigate the three process parameters of temperature, residence time and particle size, producing fuels treated using four different torrefaction conditions. The untreated and torrefied fuels were subjected to standard fuel analysis techniques including ultimate analysis, proximate analysis and calorific value determination. The grindability of these fuels was then determined using a laboratory ball mill and by adapting the Hardgrove Grindability Index (HGI) test for hard coals. After grinding, two sets of results were obtained. Firstly a determination similar to the HGI test was made, measuring the proportion of sample passing through a 75 mu m sieve and plotting this on a calibrated HGI chart determined using four standard reference coals of known HGI values. Secondly the particle size distributions of the entire ground sample were measured and compared with the four standard reference coals. The standard fuel tests revealed that temperature was the most significant parameter in terms of mass loss, changes in elemental composition and energy content increase. The first grindability test results found that the untreated fuels and fuels treated at low temperatures showed very poor grindability behaviour. However, more severe torrefaction conditions caused the fuels to exhibit similar pulverisation properties as coals with low HGI values. Miscanthus was found to have a higher HGI value than willow. On examining the particle size distributions it was found that the particle size distributions of torrefied Miscanthus differed significantly from the untreated biomass and had comparable profiles to those of the standard reference coals with which they had similar HGI values. However, only the torrefied willow produced at the most severe conditions investigated exhibited this behaviour, and the HGI of torrefied willow was not generally a reliable indicator of grindability performance for this energy crop. Overall it was concluded that torrefied biomass can be successfully pulverised and that torrefied Miscanthus was easier to grind than torrefied willow

International Trade With Quality Differentiated Goods

This thesis is primarily concerned with the role of both scale economies and demand differences between countries producing quality differentiated goods, in determining the variety of qualities produced both in autarky, and once trade opens, and on the pattern of trade. Attention is also paid to the effects of trade on individual consumers in each country.;Chapter 3 focuses on the role of demand differences within a country in determining the variety of qualities produced by both price discriminating and non-price discriminating monopolists, in a very flexible two consumer-type version of the basic model of quality differentiated goods production developed in Chapter 2. Comparing the two equilibrium configurations shows that preventing price discrimination or freeing trade between the two groups reduces either the number of qualities produced, or the average level of quality produced. High willingness to pay consumers are shown to gain consumer surplus but only in the presence of a substantial population of low willingness to pay consumers who warrant being served.;Chapter 4 examines the consequences of opening up trade between two economies where consumers in each country are assumed to be uniformly distributed over their willingness to pay for quality. Trade causes the two firms to push their qualities apart from their autarky levels, to minimize the price competition between them. All consumers are shown to gain consumer surplus as a result of the competition brought about by trade. These gains are shown to be larger between countries with narrow distributions, as the scope for firms to differentiate their qualities to avoid price competition is reduced.;Chapter 5 considers a rather special variation of the model developed in Chapter 4, which highlights the role of demand differences by assuming that the distribution of willingnesses to pay for quality for each country is characterized by a right triangular distribution, with the home country having a majority of high willingness to pay consumers, and the foreign country having a majority of low willingness to pay consumers. The pattern of trade which emerges is very much in the spirit of the Linder hypothesis as each country is producing a level of quality in keeping with its respective demand, which it exports to consumers who are on the fringe of the representative demand in the other country

Clinical Outcomes of the Ilizarov Method After an Infected Tibial Non Union

Background: The Ilizarov technique has been used in the UK for the last 20 years in the management of infected non-union of long bones. This method uses fine wires inserted percutaneously which are attached and tensioned to provide a strong frame construct. The majority of tibial and femoral non unions can be treated successfully by internal fixation. However, an infected non-union of the tibia can prove a difficult problem. The Ilizarov method can prove useful for treating these complex injuries. Objectives: To assess whether a new limb reconstruction centre in the UK has comparable results. Patients and Methods: Twelve patients (10 M: 2 F; Avg age 43.3 years) who had an infected tibial non-union between March 2009 and August 2010 treated with the Ilizarov technique. Intervention method was Ilizarov technique and main outcome measures include functional and radiological outcomes assessed using the Association for the Study and Application of Methods of Ilizarov (ASAMI) criteria, American Orthopaedic Foot and Ankle Score (AOFAS) and Visual Analogue Pain scores. Results: All twelve patients united. None required amputation. Mean time to union was 46 weeks (range 24 - 70/median 50). The average follow up time was 62 weeks (39 - 164/ median 59). According to the ASAMI score bone/radiological results ten were classed as excellent with the remainder being good. Functionally six were graded as excellent, four as good and two as poor. The average AOFAS score was 83/100 (70 - 90) and pain visual analogue scale (VAS) was two. Conclusions: Our results in terms of ASAMI scores are comparable with the published literature. Furthermore, our return to work is better than most European studies (63%). All our patients said they would have the procedure again. We attribute this success partly to the multidisciplinary approach. We recommend early referral to a dedicated unit if there is any evidence of a non-union

A matrix isolation and computational study of molecular palladium fluorides : does PdF₆ exist?

Palladium atoms generated by thermal evaporation and laser ablation were reacted with and trapped in F₂ /Ar, F₂ /Ne, and neat F₂ matrices. The products were characterized by electronic absorption and infrared spectroscopy, together with relativistic density functional theory calculations as well as coupled cluster calculations. Vibrational modes at 540 and 617 cm⁻¹ in argon matrices were assigned to molecular PdF and PdF₂ , and a band at 692 cm⁻¹ was assigned to molecular PdF₄ . A band at 624 cm⁻¹ can be assigned to either PdF₃ or PdF₆, with the former preferred from experimental considerations. Although calculations might support the latter assignment, our conclusion is that in these detailed experiments there is no convincing evidence for PdF₆

Portable LED fluorescence instrumentation for the rapid assessment of potable water quality

Characterising the organic and microbial matrix of water are key issues in ensuring a safe potable water supply. Current techniques only confirm water quality retrospectively via laboratory analysis of discrete samples. Whilst such analysis is required for regulatory purposes, it would be highly beneficial to monitor water quality in-situ in real time, enabling rapid water quality assessment and facilitating proactive management of water supply systems. A novel LED-based instrument, detecting fluorescence peaks C and T (surrogates for organic and microbial matter, respectively), was constructed and performance assessed. Results from over 200 samples taken from source waters through to customer tap from three UK water companies are presented. Excellent correlation was observed between the new device and a research grade spectrophotometer (r 2 = 0.98 and 0.77 for peak C and peak T respectively), demonstrating the potential of providing a low cost, portable alternative fluorimeter. The peak C/TOC correlation was very good (r 2 = 0.75) at low TOC levels found in drinking water. However, correlations between peak T and regulatory measures of microbial matter (2 day/3 day heterotrophic plate counts (HPC), E. coli, and total coliforms) were poor, due to the specific nature of these regulatory measures and the general measure of peak T. A more promising correlation was obtained between peak T and total bacteria using flow cytometry. Assessment of the fluorescence of four individual bacteria isolated from drinking water was also considered and excellent correlations found with peak T (Sphingobium sp. (r 2 = 0.83); Methylobacterium sp. (r 2 = 1.0); Rhodococcus sp. (r 2 = 0.86); Xenophilus sp. (r 2 = 0.96)). It is notable that each of the bacteria studied exhibited different levels of fluorescence as a function of their number. The scope for LED based instrumentation for insitu, real time assessment of the organic and microbial matrix of potable water is clearly demonstrated

Using artificial intelligence-enhanced video feedback for reflective practice in coach development: benefits and potential drawbacks

Sports coaching has used video feedback for decades to improve athlete and coach performance. More recently, artificial intelligence (AI) and machine-learning technologies have enabled analytics alongside visual review to accelerate development further. So too in coaching conversations, software allows the implementation of behavioural analytics, tracking speech patterns, body language and facial expressions to deliver performance data measured against core coaching competencies. In this study, we interviewed 15 coaches who used AI-enhanced video review software in coaching sessions with clients over several weeks and reflected on those sessions using the recordings and AI-generated data. Our aim was to discover the benefits and drawbacks of using such an approach in reflective practice. Clear benefits emerged: insights gained from video and data analysis drove deeper reflection and heightened self-awareness; coaches focused on skills development, made specific changes to their practice, developed over time and gained in confidence. Challenges included coaches’ nervousness around using new technology, viewing and analysing their own performance, and a sense that the software does not understand the subtle nuances and context of conversations. Limitations are discussed as well as the implications for coach training, reflective practice and supervision. We suggest possibilities for further study in this area

Dual Adaptation and Adaptive Generalization of the Human Vestibulo-Ocular Reflex

In two experiments, we examined the possibility that the human vestibulo-ocular reflex (VOR) is subject to dual adaptation (the ability to adapt to a sensory rearrangement more rapidly and/or more completely after repeated experience with it) and adaptive generalization (the ability to adapt more readily to a novel sensory rearrangement as a result of prior dual adaptation training). In Experiment 1, the subjects actively turned the head during alternating exposure to a visual-vestibular rearrangement (target/head gain = 0.5) and the normal situation (target/head gain = 0.0). These conditions produced both adaptation and dual adaptation of the VOR but no evidence of adaptive generalization when tested with a target/head gain of 1.0. Experiment 2, in which exposure to the 0.5 gain entailed externally controlled (i.e., passive) whole body rotation, resulted in VOR adaptation but no dual adaptation. As in Experiment 1, no evidence of adaptive generalization was found

Integrating language learning practises in first year science disciplines

Student retention and progression rates are a matter of concern for most institutions in the higher education sector (Burton & Dowling, 2005;. Simpson, 2006;. Tinto & Pusser, 2006) in Australia. There is also a substantial body of literature concentrating on the first year experience at university (for example, in the Australian context, see Krause, Hartley, James, McInnis, & Centre for the Study of Higher Education. University of Melbourne, 2005). One of the particular concerns is that the diversity of the student body is rapidly increasing. Of course, with diversity comes with differentiated level of preparation for academic study within the student body

Language difficulties in first year Science

A key goal of the study entitled ‘A cross-disciplinary approach to language support for first year students in the science disciplines’, funded by the Carrick Institute for Learning and Teaching in Higher Education, is to examine the role of language in the learning of science by first-year university students. The disciplines involved are Physics, Chemistry and Biology. This national project also aims to transfer active learning skills, which are widely used in language teaching, to the teaching of science in first year. The paper discusses the background to the study, reports on some of the preliminary results on the language difficulties faced by first year student cohorts in science from data collected in 2008, and describes the framework we have established for the organization and delivery of first year science courses to be implemented in semester one 2009

Embedding in-discipline language support for first year students in the sciences

This paper reports on a project which aims at addressing the need to cater for the language needs of a diverse student body (both domestic and international student body) by embedding strategic approaches to learning and teaching in first year sciences in tertiary education. These strategies consist of active learning skills which are widely used in language learning. The disciplines covered by the project are Biology, Chemistry and Physics and involves the University of Canberra (UC), University of Sydney (USyd), University of Tasmania (UTAS), University of Technology, Sydney (UTS) and University of Newcastle (Newcastle) in Australia. This project is funded by the Australian Learning and Teaching Council (ALTC). The paper discusses the background to the study and reports on results on the language difficulties faced by first year science student cohorts from data collected in 2008 as well as qualitative data was also collected on 2008 students’ attitudes towards online science learning. It will also report on the results on the implementation of the learning strategies at UTS and UTAS in Physics and Chemistry disciplines in 2009. Keywords: First year science teaching, role of language in science teaching, active learning skill