Conduction-radiation effect on natural convection flow in a fluid-saturated non-Darcy porous medium enclosed by non-isothermal walls

The effect of conduction-convection-radiation on natural convection flow of Newtonian optically thick gray fluid, confined in a non-Darcian porous media square cavity is numerically studied. For the gray fluid consideration is given to Rosseland diffusion approximation. Further assuming that (i) the temperature of the left vertical wall is varying linearly with height, (ii) cooled right vertical and top walls and (iii) the bottom wall is uniformly-heated. The governing equations are solved using the Alternate Direct Implicit method together with the Successive Over Relaxation technique. The investigation of the effect of governing parameters namely the Forschheimer resistance (Γ), the Planck constant (Rd), and the temperature difference (Δ), on flow pattern and heat transfer characteristics has been carried out. It was seen that the reduction of flow and heat transfer occurs as the Forschheimer resistance is increased. On the other hand both the strength of flow and heat transfer increases as the temperature ratio, Δ, is increased.

Quantifying the roles of cell motility and cell proliferation in a circular barrier assay

Moving fronts of cells are essential features of embryonic development, wound repair and cancer metastasis. This paper describes a set of experiments to investigate the roles of random motility and proliferation in driving the spread of an initially confined cell population. The experiments include an analysis of cell spreading when proliferation was inhibited. Our data have been analysed using two mathematical models: a lattice-based discrete model and a related continuum partial differential equation model. We obtain independent estimates of the random motility parameter, D, and the intrinsic proliferation rate, λ, and we confirm that these estimates lead to accurate modelling predictions of the position of the leading edge of the moving front as well as the evolution of the cell density profiles. Previous work suggests that systems with a high λ/D ratio will be characterized by steep fronts, whereas systems with a low λ/D ratio will lead to shallow diffuse fronts and this is confirmed in the present study. Our results provide evidence that continuum models, based on the Fisher–Kolmogorov equation, are a reliable platform upon which we can interpret and predict such experimental observations.

Removal of epoxy-attached thin-sections from glass slides by plasma-etching

Thin-sectioned samples mounted on glass slides with common petrographic epoxies cannot be easily removed (for subsequent ion-milling) by standard methods such as heating or dissolution in solvents. A method for the removal of such samples using a radio frequency (RF) generated oxygen plasma has been investigated for a number of typical petrographic and ceramic thin sections. Sample integrity and thickness were critical factors that determined the etching rate of adhesive and the survivability of the sample. Several tests were performed on a variety of materials in order to estimate possible heating or oxidation damage from the plasma. Temperatures in the plasma chamber remained below 138°C and weight changes in mineral powders etched for 76 hr were less than ±4%. A crystal of optical grade calcite showed no apparent surface damage after 48 hr of etching. Any damage from the oxygen plasma is apparently confined to the surface of the sample, and is removed during the ion-milling stage of transmission electron microscopy (TEM) sample preparation.

A Review of potential countermeasures for motorcycle and scooter safety practices across APEC for project : Compendium of Best Practices on Motorcycle and Scooter Safety

Motorcyclists and scooter riders are among the most vulnerable road users, across APEC. This report assesses the potential road safety measures that can be used to address these issues and selects measures that could feasibly and effectively be implemented across the Asia Pacific Economic Communities (APEC). The scope of the report is confined to on-road motorcycle riding. While the numbers of injuries resulting from off-road riding (including as part of farm work) are likely to be substantial based on data from other states, many of the issues and measures to reduce trauma in off-road riding would be quite different. A previous report described important motorcycle and scooter safety issues across APEC economies and any current barriers that might exist in implementing potentially effective countermeasures.

Groundwater visualisation system (GVS) : a software framework for integrated display and interrogation of conceptual hydrogeological models, data and time-series animation

Management of groundwater systems requires realistic conceptual hydrogeological models as a framework for numerical simulation modelling, but also for system understanding and communicating this to stakeholders and the broader community. To help overcome these challenges we developed GVS (Groundwater Visualisation System), a stand-alone desktop software package that uses interactive 3D visualisation and animation techniques. The goal was a user-friendly groundwater management tool that could support a range of existing real-world and pre-processed data, both surface and subsurface, including geology and various types of temporal hydrological information. GVS allows these data to be integrated into a single conceptual hydrogeological model. In addition, 3D geological models produced externally using other software packages, can readily be imported into GVS models, as can outputs of simulations (e.g. piezometric surfaces) produced by software such as MODFLOW or FEFLOW. Boreholes can be integrated, showing any down-hole data and properties, including screen information, intersected geology, water level data and water chemistry. Animation is used to display spatial and temporal changes, with time-series data such as rainfall, standing water levels and electrical conductivity, displaying dynamic processes. Time and space variations can be presented using a range of contouring and colour mapping techniques, in addition to interactive plots of time-series parameters. Other types of data, for example, demographics and cultural information, can also be readily incorporated. The GVS software can execute on a standard Windows or Linux-based PC with a minimum of 2 GB RAM, and the model output is easy and inexpensive to distribute, by download or via USB/DVD/CD. Example models are described here for three groundwater systems in Queensland, northeastern Australia: two unconfined alluvial groundwater systems with intensive irrigation, the Lockyer Valley and the upper Condamine Valley, and the Surat Basin, a large sedimentary basin of confined artesian aquifers. This latter example required more detail in the hydrostratigraphy, correlation of formations with drillholes and visualisation of simulation piezometric surfaces. Both alluvial system GVS models were developed during drought conditions to support government strategies to implement groundwater management. The Surat Basin model was industry sponsored research, for coal seam gas groundwater management and community information and consultation. The “virtual” groundwater systems in these 3D GVS models can be interactively interrogated by standard functions, plus production of 2D cross-sections, data selection from the 3D scene, rear end database and plot displays. A unique feature is that GVS allows investigation of time-series data across different display modes, both 2D and 3D. GVS has been used successfully as a tool to enhance community/stakeholder understanding and knowledge of groundwater systems and is of value for training and educational purposes. Projects completed confirm that GVS provides a powerful support to management and decision making, and as a tool for interpretation of groundwater system hydrological processes. A highly effective visualisation output is the production of short videos (e.g. 2–5 min) based on sequences of camera ‘fly-throughs’ and screen images. Further work involves developing support for multi-screen displays and touch-screen technologies, distributed rendering, gestural interaction systems. To highlight the visualisation and animation capability of the GVS software, links to related multimedia hosted online sites are included in the references.

Growing profitable or growing from profits : putting the horse in front of the cart?

Top lists of and praise for the economy's fastest growing firms abound in business media around the world. Similarly, in academic research there has been a tendency to equate firm growth with business success. This tendency appears to be particularly pronounced in-but not confined to­ entrepreneurship research. In this study we critically examine this tendency to portray firm growth as more or less universally favorable. While several theories suggest that growth drives profitability we first show that the available empirical evidence does not support the existence of a general, positive relation­ ship between growth and profitability. Using the theoretical lens of the Resource-Based View (RBV) we then argue that sound growth usually starts with achieving sufficient levels of profitability. In summary, our theoretical argument is as follows: In a population of SMEs, superior profitability is likely to be indicative of having built a resource-based competitive advantage. Building such a valuable and hard to-copy advantage may at first constrain growth. However, the underlying advantage itself and the financial resources generated through high profitability make it possible for firms in this situation to now achieve sound and sustainable growth - which may require building a series of temporary advantages- without having to sacrifice profitability. By contrast, when firms strive for high growth starting from low profitability, the latter often indicates lack of competitive advantage. Therefore growth must be achieved in head-to-head competition with equally attractive alternatives, leading to profitability deterioration rather than improvement. In addition, these low profitability firms are unlikely to be able to finance strategies toward building valuable and difficult-to-imitate advantages while growing.

A water-dielectric capacitor using hydrated graphene oxide film

Despite the widespread use of paper, plastic or ceramics in dielectric capacitors, water has not been commonly used as a dielectric due to its tendency to become conductive as it easily leaches ions from the environment. We show here that when water is confined between graphene oxide sheets, it can retain its insulating nature and behave as a dielectric. A hydrated graphene oxide film was used as a dielectric spacer to construct a prototype water-dielectric capacitor. The capacitance depends on the water content of the hydrated GO film as well as the voltage applied to the device. Our results show that the capacitance per unit area of the GO film is in the range of 100–800 mF cm �2, which is 5–40 times that of the double layer capacitance per surface area of activated carbon.

Intracellular trafficking and secretion of inflammatory cytokines

The secretion of cytokines by immune cells plays a significant role in determining the course of an inflammatory response. The levels and timing of each cytokine released are critical for mounting an effective but confined response, whereas excessive or dysregulated inflammation contributes to many diseases. Cytokines are both culprits and targets for effective treatments in some diseases. The multiple points and mechanisms that have evolved for cellular control of cytokine secretion highlight the potency of these mediators and the fine tuning required to manage inflammation. Cytokine production in cells is regulated by cell signaling, and at mRNA and protein synthesis levels. Thereafter, the intracellular transport pathways and molecular trafficking machinery have intricate and essential roles in dictating the release and activity of cytokines. The trafficking machinery and secretory (exocytic) pathways are complex and highly regulated in many cells, involving specialized membranes, molecules and organelles that enable these cells to deliver cytokines to often-distinct areas of the cell surface, in a timely manner. This review provides an overview of secretory pathways - both conventional and unconventional - and key families of trafficking machinery. The prevailing knowledge about the trafficking and secretion of a number of individual cytokines is also summarized. In conclusion, we present emerging concepts about the functional plasticity of secretory pathways and their modulation for controlling cytokines and inflammation.

Introduction to the special issue

Creative productivity emerges from human interactions (Hartley, 2009, p. 214). In an era when life is lived in rather than with media (Deuze, this issue), this productivity is widely distributed among ephemeral social networks mediated through the internet. Understanding the underlying dynamics of these networks of human interaction is an exciting and challenging task that requires us to come up with new ways of thinking and theorizing. For example, inducting theory from case studies that are designed to show the exceptional dynamics present within single settings can be augmented today by largescale data generation and collections that provide new analytic opportunities to research the diversity and complexity of human interaction. Large-scale data generation and collection is occurring across a wide range of individuals and organisations. This offers a massive field of analysis which internet companies and research labs in particular are keen on exploring. Lazer et al (2009: 721) argue that such analytic potential is transformational for many if not most research fields but that the use of such valuable data must neither remain confined to private companies and government agencies nor to a privileged set of academic researchers whose studies cannot be replicated nor critiqued. In fact, the analytic capacity to have data of such unprecedented scope and scale available not only requires us to analyse what is and could be done with it and by whom (1) but also what it is doing to us, our cultures and societies (2). Part (1) of such analysis is interested in dependencies and their implications. Part (2) of the enquiry embeds part (1) in a larger context that analyses the long-term, complex dynamics of networked human interaction. From the latter perspective we can treat specific phenomena and the methods used to analyse them as moments of evolution.

An objective measure of reactive behaviour in horses

Several tests have been devised in an attempt to detect behaviour modification due to training, supplements or diet in horses. These tests rely on subjective observations in combination with physiological measures, such as heart rate (HR) and plasma cortisol concentrations, but these measures do not definitively identify behavioural changes. The aim of the present studies was to develop an objective and relevant measure of horse reactivity. In Study 1, HR responses to auditory stimuli, delivered over 6 days, designed to safely startle six geldings confined to individual stalls was studied to determine if peak HR, unconfounded by physical exertion, was a reliable measure of reactivity. Both mean (±SEM) resting HR (39.5 ± 1.9 bpm) and peak HR (82 ± 5.5 bpm) in response to being startled in all horses were found to be consistent over the 6 days. In Study 2, HR, plasma cortisol concentrations and speed of departure from an enclosure (reaction speed (RS)) in response to a single stimulus of six mares were measured when presented daily over 6 days. Peak HR response (133 ± 4 bpm) was consistent over days for all horses, but RS increased (3.02 ± 0.72 m/s on Day 1 increasing to 4.45 ± 0.53 m/s on Day 6; P = 0.005). There was no effect on plasma cortisol, so this variable was not studied further. In Study 3, using the six geldings from Study 1, the RS test was refined and a different startle stimulus was used each day. Again, there was no change in peak HR (97.2 ± 5.8 bpm) or RS (2.9 ± 0.2 m/s on Day 1 versus 3.0 ± 0.7 m/s on Day 6) over time. In the final study, mild sedation using acepromazine maleate (0.04 mg/kg BW i.v.) decreased peak HR in response to a startle stimulus when the horses (n = 8) were confined to a stall (P = 0.006), but not in an outdoor environment when the RS test was performed. However, RS was reduced by the mild sedation (P = 0.02). In conclusion, RS may be used as a practical and objective test to measure both reactivity and changes in reactivity in horses.

Incongruence between self-reported and observed senior physical education teaching styles : an analysis using Mosston and Ashworth’s spectrum

Pedagogical styles, methods, models, practices or strategies are valued for what they claim they can achieve. In recent times curriculum documents and governments have called for a range of teaching approaches to meet the variety of learner differences and allow students to make more independent decision making in physical education (Hardy and Mawer, 1999). One well known system of categorizing teaching styles is the Mosston and Ashworth’s Spectrum of Teaching Styles (2002). In Queensland, prior to 2005, no research had been conducted on the teaching styles used by teachers of Physical Education. However, many teachers self-reported that they employed a variety of teaching styles depending on the aims and content of the material to be taught (Cothran, et al., 2005). This research, for the first time, collected teacher’s self-reported use of teaching styles and through observations verify the styles that were being used to teach Senior Physical Education in Queensland. More specifically the aims of the research were to determine: a) What teaching styles teachers of Senior Physical Education in Queensland believe they use? i) Were they using a range of teaching styles? ii) Were teachers of Senior Physical Education in Queensland using teaching styles that the Queensland Senior Physical Education Syllabus (2004) required? b) If Mosston and Ashworth’s (2002) Spectrum of Teaching Styles were used to categorise styles observed during the teaching of Senior Physical Education did the styles being used provide opportunities for evaluating as described by the Queensland Senior Physical Education Syllabus (2004)? The research was conducted in two phases. Part A involved use of a questionnaire to determine the teaching styles Queensland teachers of Senior Physical Education reported using and how often they reported using them. The questionnaire was administered to 110 teachers throughout Queensland. The sample was determined from 346 schools teaching Senior Physical Education (in 2006) across the state of Queensland, Australia. 286 questionnaires were sent to 77 non-randomised schools. There were 66 male and 44 female respondents in the sample. A wide range of teaching styles were reportedly used by teachers of Senior Physical Education with Practice Style-Style B, Command Style-Style A and Divergent Discovery Style-Style H, the most reportedly used. The Self-Teaching Style-Style K was reportedly used the least by teachers involved in this study. From the respondents a group of teachers were identified to form the participants for Part B. Part B of the study involved observation of a group of volunteer participants (from those who had completed the questionnaire) who displayed many of the ‘typical’ characteristics, and a cross-section of backgrounds, of teachers of Senior Physical Education in Queensland. In the case of this study, the criteria used to select the group of teachers to be observed teaching were, teaching experience (number of years: 0-4, 5-10 and 11 years and over), gender, geographical location of schools (focused on Brisbane and near area for travel/access purposes), profile of the students at schools (girls, boys or co-educational), nature of school (Government or Private) and the physical activities being taught in a school (activities to reflect all the areas of physical activity outlined within the syllabus). A total of 27 questionnaire respondents from Part A indicated that they were willing to be observed teaching practical lessons. The respondents who volunteered to be involved in Part B of the study came from different regions across the state of Queensland and was not confined to the Brisbane metropolitan area or large cities. From the group of people who volunteered for Part B four came from outside Brisbane and 23 from the Brisbane area. The final observation group of nine participants included eight teachers from the Brisbane area and one from a rural area. The characteristics of the final group included three females and six males from private and public schools with a range of teaching experience in years and a range of physical activities. Four year 12 and five year 11 teachers and their classes were videoed on three occasions as they progressed through an eight – nine week unit of work. This resulted in 24 hours 48 minutes and 20 seconds (or 4465 observations) of video teaching data which was subsequently coded by several researchers (99% interobserver reliability) to determine the teaching styles employed by the participants. This research indicated that, based on Mosston and Ashworth’s (2002) Spectrum of Teaching Styles, teachers of Senior Physical Education in Queensland used predominantly one style to teach 27 observed lessons. This is in sharp contrast to the variety of styles 110 teachers self- reportedly used and in spite of the Queensland Senior Physical Education Syllabus (2004) suggesting a range of specific styles be used. These results are discussed in the context of the Queensland Senior Physical Education Syllabus (2004), teacher knowledge of teaching styles and high-stakes curriculum and external pressures such as national testing and the publication of data from schools in tabloid newspapers. The data and findings in this research provide a rationale for improving teacher knowledge regarding teaching styles and the need for a clear definition of terminology in syllabus documents. Careful examination of the effects that the publishing of school data may have on teaching styles is advised. This research not only collected teacher’s perceptions of the teaching styles they believed they used it also verified these claims through direct observations of the teachers while teaching. These findings are relevant to syllabus writers, teacher educators, policy makers within education and teachers.

Establishing design thinking : accident, program frameworks and personal practices

Distribution through electronic media provides an avenue for promotion, recognition and an outlet of display for graphic designers. The emergence of available media technologies have enabled graphic designers to extend these boundaries of their practice. In this context the designer is constantly striving for aesthetic success and is strongly influenced by the fashion and trends of contemporary design work. The designer is always in a state of inquiry, finding pathways of discovery that lead to innovation and originality that are highly valued criteria for self-evaluation. This research is based on an analysis of the designer perspective and the processes used within an active graphic design practice specializing entirely within a digital collage domain. Contemporary design methodologies were critically examined, compared and refined to reflect the self-practice of the researcher. The refined methodology may assist designers in maintaining systematic work practices, as well as promote the importance of exploration and experimentation processes. Research findings indicate some differences in the identified methodologies and the design practice of the researcher in the sense that many contemporary designers are not confined to a client-base but are self-generating design images influenced by contemporary practitioners. As well as confirming some aspects of more conventional design processes, the researcher found that accidental discoveries and the designer’s interaction with technology plays a significant part in the design process.

Encapsulation of transition metal species into zeolites and molecular sieves as redox catalysts: Part I-preparation and characterisation of nanosized TiO2, CdO and ZnO semiconductor particles anchored in NaY zeolite

In this paper, we report the preparation and characterisation of nanometer-sized TiO2, CdO, and ZnO semiconductor particles trapped in zeolite NaY. Preparation of these particles was carried out via the traditional ion exchange method and subsequent calcination procedure. It was found that the smaller cations, i.e., Cd2+ and Zn2+ could be readily introduced into the SI′ and SII′ sites located in the sodalite cages, through ion exchange; while this is not the case for the larger Ti species, i.e., Ti monomer [TiO]2+ or dimer [Ti2O3]2+ which were predominantly dispersed on the external surface of zeolite NaY. The subsequent calcination procedure promoted these Ti species to migrate into the internal surface of the supercages. These semiconductor particles confined in NaY zeolite host exhibited a significant blue shift in the UV-VIS absorption spectra, in contrast to the respective bulk semiconductor materials, due to the quantum size effect (QSE). The particle sizes calculated from the UV-VIS optical absorption spectra using the effective mass approximation model are in good agreement with the atomic absorption data.

Feasibility of ranking articular cartilage conditions with non-destructive near-infrared spectroscopy with extension to the Mankin grading system

Grading osteoarthritic tissue has, until now, been a laboratory process confined to research activities. This thesis establishes a scientific protocol that extends osteoarthritic tissue ranking to surgical practice. The innovative protocol, which now incorporates the structural degeneration of collagen, enhances the traditional Modified Mankin ranking system, enabling its application to real time decision during surgery. Because it is fast and without time consuming laboratory process, it would potentially enable the cataloguing of tissues in osteoarthritic joints in all compartments of diseased joints during surgery for epistemological study and insight into the manifestation of osteoarthritis across age, gender, occupation, physical activities and race.

Dislocations of desire : the transnational movement of gifts within the Vietnamese diaspora

Gifts have intrigued and challenged scholars ever since interest in the subject was piqued by Marcel Mauss who, in 1925, wrote the book The gift: The form and reason for exchange in archaic societies. Although ethnographic studies of giftgiving have been mostly confined to small-scale communities, scholars have more recently turned their attention to industrial societies, with studies of Christmas giving, Japanese gift-giving, etc. Now, as studies of consumption are entering a phase of efflorescence, it is time to re-evaluate gift-giving. The recent rapid expansion in the transnational flow of people, objects and ideas has had an impact on the social conditions associated with new global patterns of consumption. In this atmosphere of overlapping cultural, economic and political worlds, there is a need to look again at the objects that pass between us as gifts...