Strain and Temperature Sensing Properties of Multiwalled Carbon Nanotube Yarn Composites

Strain and temperature response of Multiwalled Carbon Nanotube (MWCNT/CNT) yarns on a stainless steel test beam has been studied. The carbon nanotube yarns are spun from a multiwalled carbon nanotube forest grown on a silicon substrate to a 4-ply yarn with a diameter of about 15-20 microns. Four of the 4-ply CNT yarns are arranged in a Wheatstone bridge configuration on the stainless steel test beam using a thin layer of polyurethane resin that insulates and protects the yarns from the test beam. Strain sensitivities of the CNT yarn sensors range from 1.39 to 1.75 mV/V/1000 microstrain at room temperature, and temperature sensitivity of the CNT yarn bridge is 91 microA/degC. Resistance of the yarns range from 215 to 270 ohms for CNT yarn length of approximately 5 mm. Processes used in attaching the CNT yarns on the test beam and experimental procedures used for the measurements are described. Conventional metallic foil strain gages are attached to the test beam to compare with the CNT sensors. The study demonstrates multifunctional capability of the sensor for strain and temperature measurements and shows its applicability where engineering strain is less than 3%

Deformation and Failure of a Multi-Wall Carbon Nanotube Yarn Composite

Forests of multi-walled carbon nanotubes can be twisted and manipulated into continuous fibers or yarns that exhibit many of the characteristics of traditional textiles. Macro-scale analysis and test may provide strength and stiffness predictions for a composite composed of a polymer matrix and low-volume fraction yarns. However, due to the nano-scale of the carbon nanotubes, it is desirable to use atomistic calculations to consider tube-tube interactions and the influence of simulated twist on the effective friction coefficient. This paper reports laboratory test data on the mechanical response of a multi-walled, carbon nanotube yarn/polymer composite from both dynamic and quasi-static tensile tests. Macroscale and nano-scale analysis methods are explored and used to define some of the key structure-property relationships. The measured influence of hot-wet aging on the tensile properties is also reported

Elastic Response and Failure Studies of Multi-Wall Carbon Nanotube Twisted Yarns

Experimental data on the stress-strain behavior of a polymer multiwall carbon nanotube (MWCNT) yarn composite are used to motivate an initial study in multi-scale modeling of strength and stiffness. Atomistic and continuum length scale modeling methods are outlined to illustrate the range of parameters required to accurately model behavior. The carbon nanotubes yarns are four-ply, twisted, and combined with an elastomer to form a single-layer, unidirectional composite. Due to this textile structure, the yarn is a complicated system of unique geometric relationships subjected to combined loads. Experimental data illustrate the local failure modes induced by static, tensile tests. Key structure-property relationships are highlighted at each length scale indicating opportunities for parametric studies to assist the selection of advantageous material development and manufacturing methods

Context and the leadership experience and perceptions of professionals: a review of the nursing profession

Purpose: Leadership studies which focus on categorising leadership styles have been critiqued for failure to consider the lived experience of leadership. The purpose of this paper is to use the framework of Jepson’s model of contextual dynamics to explore whether this framework assists understanding of the “how and why” of lived leadership experience within the nursing profession. Design/methodology/approach: Themes for a purposeful literature search and review, having regard to the Jepson model, are drawn from the contemporary and dynamic context of nursing. Government reports, coupled with preliminary interviews with a nurse leadership team, guided selection of contextual issues. Findings: The contextual interactions arising from managerialism, existing hierarchical models of leadership and increasing knowledge work provided insights into leadership experience in nursing, in the contexts of professional identity and changing educational and generational profiles of nurses. The authors conclude that employing a contextual frame provides insights in studying leadership experience. The author propose additions to the cultural and institutional dimensions of Jepson’s model.Practical implications: The findings have implications for structuring and communicating key roles and policies relevant to nursing leadership. These include the need to: address perceptions around the legitimacy of current nursing leaders to provide clinical leadership; modify hierarchical models of nursing leadership; address implications of the role of the knowledge workers. Originality/value: Observing nursing leadership through the lens of Jepson’s model of contextual dynamics confirms that this is an important way of exploring how leadership is enacted. The authors found, however, the model also provided a useful frame for considering the experience and understanding of leadership by those to be led

Context of Leadership: Nursing and Midwifery in the Western Australian Public Health System

The paper reports on Stage One of a three stage research project undertaken for the Nursing and Midwifery Office, Western Australian Department of Health. It was designed to contribute an understanding of perceptions of the practice of leadership in nursing and midwifery through interviews and focus groups with key stakeholders we found that nurses recognised that in their changing environment there was a need for adaptive leadership supported by leadership which was open, encouraged and nurtured nurses. The importance of administrative leadership to manage the ongoing operation of the system was also remarked on. We found that organisational context and the values framework of a professional workforce can have a significant impact, in practice, on the influencing capacities of leaders

Explorative study of the sensitivity and specificity of the pronator quadratus fat pad sign as a predictor of subtle wrist fractures

Objective: To investigate the value of post-traumatic pronator quadratus (PQ) fat pad sign as a reliable predictor of subtle wrist fractures. Materials and methods: This was a prospective study of 68 patients undergoing X-ray for traumatic wrist injuries and subsequent MRI. The reliability of a positive PQ fat pad sign on X-ray, defined as either raised, interrupted or obliterated, was evaluated in detection of subtle wrist fractures. Results: Out of 68 patients, 28 had a positive PQ sign without any obvious bony injuries on plain radiographs; of these, the PQ fat pad was obliterated in 11, disrupted in 12, and raised in five cases. Fractures defined as cortical interruption or trabecular fractures were revealed in 13/28 (46 %) patients with a positive PQ sign but only in 7/40 (18 %) patients with a negative sign. With regards to different types of abnormal PQ fat planes, fractures were present in 7/12 patients with a disrupted plane (58 %), 6/11 patients with an obliterated plane (54 %), and none of the patients with a raised plane. The overall sensitivity and specificity of a positive PQ sign in the prediction of occult wrist fractures were 65 and 69 %, respectively. Conclusions: Our findings indicate that a positive pronator quadratus (PQ) fat pad sign is not a reliable predictor of subtle fractures of the wrist, although we believe that it is a useful radiographic sign in justifying MRI for further clarification of possible joint abnormalities including occult fracture and cortex interruption

Ways of spectating: unravelling spectator participation in Kinect play

We explore spectating on video game play as an interactional and participatory activity. Drawing on a corpus of video recordings capturing 'naturally occurring' Kinect gaming within home settings, we detail how the analytic 'work' of spectating is interactionally accomplished as a matter of collaborative action with players and engagement in the game. We examine: spectators supporting players with continuous 'scaffolding'; spectators critiquing player technique during and between moments of play; spectators recognising and complimenting competent player conduct; and spectators reflecting on prior play to build instructions for the player. From this we draw out a number of points that shift the conversation in HCI about 'the spectator' towards understanding and designing for spectating as an interactional activity; that is, sequentially ordered and temporally coordinated. We also discuss bodily conduct and the particular ways of 'seeing' involved in spectating, and conclude with remarks on conceptual and design implications for HCI

Embeddedness and sequentiality in social media

Over the last decade, there has been an explosion of work around social media within CSCW. A range of perspectives have been applied to the use of social media, which we characterise as aggregate, actor-focussed or a combination. We outline the opportunities for a perspective informed by ethnomethodology and conversation analysis (EMCA)—an orientation that has been influential within CSCW, yet has only rarely been applied to social media use. EMCA approaches can complement existing perspectives through articulating how social media is embedded in the everyday lives of its users and how sequentiality of social media use organises this embeddedness. We draw on a corpus of screen and ambient audio recordings of mobile device use to show how EMCA research is generative for understanding social media through concepts such as adjacency pairs, sequential context, turn allocation / speaker selection, and repair

Conversation analysis (CA)

Conversation analysis (CA) is an approach to the study of language and social interaction that puts at center stage its sequential development. The chain of initiating and responding actions that characterizes any interaction is a source of internal evidence for the meaning of social behavior as it exposes the understandings that participants themselves give of what one another is doing. Such an analysis requires the close and repeated inspection of audio and video recordings of naturally occurring interaction, supported by transcripts and other forms of annotation. Distributional regularities are complemented by a demonstration of participants' orientation to deviant behavior. CA has long maintained a constructive dialogue and reciprocal influence with linguistic anthropology. This includes a recent convergence on the cross-linguistic and cross-cultural study of social interaction

The Aussie, 1918-1931: cartoons, digger remembrance and First World War identity

Feelings of community, cultural definition and memory were kept alive through the soldiers’ mass circulation tabloid, the Aussie, examined here in the light of theorization of memory and representation, applied to both text and cartoons. The publication’s aim for veterans’ values to become shared national values is analysed in the light of its high profile usage of soft cartoon humour and also of nostalgia – highlighting the limitations as well as the effectiveness in terms of Australia’s evolving national identity. When the post-war economic situation worsened, deeper issues of national tension were glossed over by the use of scapegoats such as ‘profiteers’ and ‘lazy workers’. The armed forces were obliged to take on a political role of lobbying for their cause, but the Aussie as ‘cheerful friend’ experienced its own identity crisis that proved to be terminal