Electromagnetic energy harvesting in a head-mountable DBS device using a circular PIFA

A circular planar inverted-F antenna (PIFA) is designed and simulated at the industrial, scientific, and medical (ISM) band of 915 MHz for energy harvesting in a head-mountable deep brain stimulation device. Moreover, a rectifier is designed, and also the interaction of the PIFA with a rat head model is investigated. In the proposed PIFA, the top radiating layer is meandered, and a substrate of FR-4 is used. The radius and the height of the antenna are 10 mm and 1.8 mm, respectively. The bottom conductive layer works as a ground plate, and a superstrate of polyethylene reduces the electromagnetic penetration into the rat head. The resonance frequency of the designed antenna is 915 MHz with a bandwidth of 18 MHz at the return loss of -10 dB in free space. The antenna parameters (e.g. reflection coefficient, gain, radiation efficiency), electric field distribution, and SAR value are evaluated within a seven-layer rat head model by using the finite difference time domain EM simulation software XFdtd. The interactions of the antenna and the rat head model are studied in both functional and biological aspects.

Effect of multiple cations in the feed solution on the performance of forward osmosis

In this study, different combinations of feed stream such as 0.2, 0.3 and 0.4 M of CaCl2 were, respectively, added with 1.0, 0.9 and 0.8 M of NaCl while maintaining the draw solution concentration at either 2.0 M of NaCl or CaCl2 in order to compare likely changes to the flux generated when the feed stream contained NaCl only. The results obtained showed that more constituents in feed stream generated lesser flux. Increase in CaCl2 concentration in feed stream resulted in more severe dilutive internal concentration polarisation (DICP) and hence, reduction in the performance ratio. The temperature and distribution of aggregated particle size also played a significant role in the overall performance of forward osmosis process. Further analysis showed that there is a relationship between the normalised driving force and flux behaviour which is governed by the effect of DICP. Additionally, the reflection coefficient was not unity as less than 2% traces of salt was found to permeate alongside with water towards the draw solution side. © 2014 © 2014 Balaban Desalination Publications. All rights reserved.

From personal reflection to social positioning: the development of a transformational model of a professional education in midwifery

A transformational model of professional identity formation, anchored and globalized in workplace conversations, is advanced. Whilst the need to theorize the aims and methods of clinical education has been served by the techno-rational platform of 'reflective practice', this platform does not provide an adequate psychological tool to explore the dynamics of social episodes in professional learning and this led us to positioning theory. Positioning theory is one such appropriate tool in which individuals metaphorically locate themselves within discursive action in everyday conversations to do with personal positioning, institutional practices and societal rhetoric. This paper develops the case for researching social episodes in clinical education through professional conversations where midwifery students, in practice settings, are encouraged to account for their moment-by-moment interactions with their preceptors/midwives and university mentors. It is our belief that the reflection elaborated by positioning theory should be considered as the new epistemology for professional education where professional conversations are key to transformative learning processes for persons and institutions.

Guided reflection: transcending a routine approach in the management of sexually transmissible infections

This paper describes a distinctive approach to the sexually transmissible infections (STI) clinical consultation: 'the guided reflection approach'. The authors coined this term and identified the guided reflection approach through analysis of 22 in-depth interviews with practitioners who provide care for people with STI, and 34 people who had attended a healthcare facility in Australia for screening or treatment of an STI. A grounded theory method was used to collect and analyse this information. The data revealed when the STI consultation is conducted using the principles characterized by the guided reflection approach creates contexts for sexual empowerment that have the potential to effectively assist people to gain autonomy for safe sex. Routinely, most of the practitioners in this study were shown to direct the STI consultation towards risk behaviours and practices and prevention of transmission, with minimal intervention. However, this study shows that if clinical interaction is to make a difference to the patient's autonomy for sexual behaviour, two changes will be required. First, practitioners need to adopt the goal of assisting patients to attain levels of autonomy, and second, practitioners require education to assist them to develop the interactive skills needed to engage patients in dialogue and reflection about sexual behaviour.

Skin friction coefficient on a yarn package surface in ring spinning

The skin friction coefficient on the surface of a rotating yarn package affects the power required to drive the package. This paper examines the relationship between the skin friction coefficient on the package surface and its diameter and rotating speed, based on the fundamentals of aerodynamics and the experimental results of power consumption. Skin friction coefficients on the surfaces of an airplane, car top, and yarn package are discussed. The results indicate that the skin friction coefficient on the package surface without hairiness depends on the package diameter and spindle speed only. The skin friction coefficient on the yarn package surface is about three times that on the top surface of a car, and is about twenty times that on an airplane surface. The power consumed to overcome skin friction drag is more than that consumed to drive the spindle if the spindle speed is very slow. However, the situation reverses when the spindle speed is fast.

Critical reflection in social work: a response to globalisation?

This article presents a reflective theoretical deconstruction of my practice with disempowered human service workers. Specifically, it presents a case study of how critical reflection was fostered amongst a group of practitioners in Geelong, a regional Victorian town in Australia. This models how a critical postmodern analysis provided a framework for overcoming entrenched power dynamics and structural barriers in a particular context and at a particular point in time. It describes and analyses the content of this work in terms of its significance and implications for responding to the impact of globalisation on this group, which was undermining the effectiveness of their social work practice.

Influence of the geometry of an immersed steel workpiece on mass transfer coefficient in a chemical heat treatment fluidised bed

The mass transfer during carburising in a fluidised bed and in a steel workpiece has been studied experimentally in this work. This involved carburising experiment in an electrically heated fluidised bed at 900–970°C with natural gas and air as the atmosphere. A steel workpiece was designed to provide a range of carbon transfer surfaces of different geometries in the fluidised bed, and the carbon transfer coefficient was measured at these surfaces. The carbon transfer coefficient was determined from the carbon distribution within the diffusion layer of the sample. An empirical relationship of the carbon potential as a function of carburising atmosphere, bed temperature and fluidising velocity was determined, based on the understanding of the mass transfer mechanism and analysis of the experimental results.

Application of bending under tension test to determine the effect of tool radius and the contact pressure on the coefficient of friction in sheet metal forming

To quantify the frictional behaviour in sheet forming operations, several laboratory experiments which simulate the real forming conditions are performed. The Bending Under Tension Test is one such experiment which is often used to represent the frictional flow of sheet material around a die or a punch radius. Different mathematical representations are used to determine the coefficient of friction in the Bending Under Tension Test. In general the change in the strip thickness in passing over the die radius is neglected and the radius of curvature to thickness ratio is assumed to be constant in these equations. However, the effect of roller radius, sheet thickness and the surface pressure are also omitted in some of these equations. This work quantitatively determined the effect of roller radius and the tooling pressure on the coefficient of friction. The Bending Under Tension Test was performed using rollers with different radii and also lubricants with different properties. The tool radii were found to have a direct influence in the contact pressure. The effect of roller radius on friction was considerable and it was observed that there is a clear relationship between the contact pressure and the coefficient of friction.

Capturing the ephemeral : reflection-in-action as research

This paper considers two different methodological approaches to 'capturing' and analysing reflection-in-action in process drama teaching. Reflection-in-action, the 'thinking on your feet' that drama teachers constantly do, is ephemeral and difficult to record. In the first project discussed here, a teacher researcher study, examines the problem of representing the reflection-in-action, working around the central question of 'How can I as a researcher describe and document my reflection-in- action when working as a teacher in process drama?' The second project, an interview-based research project', developed some of the findings of the first study through a series of interviews with drama practitioners. This paper considers these methodological approaches in terms of the possibilities they provide, the limitations for the study of reflection-in- action in process drama and some possible applications of the approaches investigated for future drama research

Carburising and carbon transfer coefficient in a fluidised bed furnance

The carburising of a steel workpiece with complex geometry in a fluidised bed hasbeen studied experimentally. This involved carburising experiment in an electrically heated fluidised bed at 900 - 970°C with natural gas and air as the atmosphere. The carbon transfer coefficient at the workpiece surface and diffusivity within the workpiece were determined from the carbon distribution within the diffusion layer of the sample. A reverse method and the Levenberg-Marquardt algorithm were used in the calculations. The methodology of the reverses method to extract the carbon transfer coefficient and diffusivity is also discussed in some detail.