945 resultados para Impacting drop
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Electrochemical processes in mesoporous TiO2-Nafion thin films deposited on indium tin oxide (ITO) electrodes are inherently complex and affected by capacitance, Ohmic iR-drop, RC-time constant phenomena, and by potential and pH-dependent conductivity. In this study, large-amplitude sinusoidally modulated voltammetry (LASMV) is employed to provide access to almost purely Faradaic-based current data from second harmonic components, as well as capacitance and potential domain information from the fundamental harmonic for mesoporous TiO2-Nafion film electrodes. The LASMV response has been investigated with and without an immobilized one-electron redox system, ferrocenylmethyltrimethylammonium+. Results clearly demonstrate that the electron transfer associated with the immobilized ferrocene derivative follows two independent pathways i) electron hopping within the Nafion network and ii) conduction through the TiO2 backbone. The pH effect on the voltammetric response for the TiO2 reduction pathway (ii) can be clearly identified in the 2nd harmonic LASMV response with the diffusion controlled ferrocene response (i) acting as a pH independent reference. Application of second harmonic data derived from LASMV measurement, because of the minimal contribution from capacitance currents, may lead to reference-free pH sensing with systems like that found for ferrocene derivatives.
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Liquid metal marbles that are droplets of liquid metal encapsulated by micro- or nanoparticles are introduced. Droplets of galinstan liquid metal are coated with insulators (including Teflon and silica) and semiconductors (including WO3, TiO2, MoO3, In2O3 and carbon nanotubes) by rolling over a powder bed and also by submerging in colloidal suspensions. It is shown that these marbles can be split and merged, can be suspended on water, and are even stable when moving under the force of gravity and impacting a flat solid surface. Furthermore, the marble coating can operate as an active electronic junction and the nanomaterial coated liquid metal marble can act as a highly sensitive electrochemical based heavy metal ion sensor. This new element thus represents a significant platform for the advancement of research into soft electronics.
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The charge transfer-mediated surface enhanced Raman scattering (SERS) of crystal violet (CV) molecules that were chemically conjugated between partially polarized silver nanoparticles and optically smooth gold and silver substrates has been studied under off-resonant conditions. Tyrosine molecules were used as a reducing agent to convert silver ions into silver nanoparticles where oxidised tyrosine caps the silver nanoparticle surface with its semiquinone group. This binding through the quinone group facilitates charge transfer and results in partially oxidised silver. This establishes a chemical link between the silver nanoparticles and the CV molecules, where the positively charged central carbon of CV molecules can bind to the terminal carboxylate anion of the oxidised tyrosine molecules. After drop casting Ag nanoparticles bound with CV molecules it was found that the free terminal amine groups tend to bind with the underlying substrates. Significantly, only those CV molecules that were chemically conjugated between the partially polarised silver nanoparticles and the underlying gold or silver substrates were found to show SERS under off-resonant conditions. The importance of partial charge transfer at the nanoparticle/capping agent interface and the resultant conjugation of CV molecules to off resonant SERS effects was confirmed by using gold nanoparticles prepared in a similar manner. In this case the capping agent binds to the nanoparticle through the amine group which does not facilitate charge transfer from the gold nanoparticle and under these conditions SERS enhancement in the sandwich configuration was not observed.
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Whilst there is a growing body of research considering corporate social responsibility (CSR) communication, calls have been made to consider the ‘how’ of CSR communication (Maon, Lindgreen, & Swaen, 2010). The challenge with exploring this however, is that communication research has largely been criticised for failing to consider the macro-phenomena impacting communication (Jones, Watson, Gardner, & Gallois, 2004; Lammers & Barbour, 2006). As such, limited attention has been given to who organisations need to indicate their responsiveness to in relation to CSR, and in turn, why they communicate about certain activities in their CSR reports. Without exploring these ideas, and hence, gaining an understanding of the macro-phenomena impacting CSR communication, we limit our understanding of the ‘how’ of CSR communication. As such, this study sought to explore both the why of CSR communication, and in turn, the implications this may have for the how of CSR communication. To do this, this study drew on the notions of institutional theory, legitimacy, and rhetoric, and explored propositions drawn from these concepts to consider the why and how of CSR communication. Extended abstract attached
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Mentoring relationships during pre-service education are a significant relationship through which emerging teachers negotiate their teacher identity (Iancu-Haddad & Oplatka, 2009; Hudson, 2010). It is therefore important to understand how mentor teachers frame their expectations. This paper explores mentoring relationships established within a Queensland partnership program funded through the Federal Government’s Improving Teacher Quality National Partnership Agreement (DEEWR, 2011). Within the broader policy context, these mentoring relationships were seen as an important space for pre-service teachers to experience cultural induction into Education Queensland schooling, and be advocates for quality teaching (Willis, Bahr, Bannah, & Welch, 2012). Interview and survey data from 14 teacher mentors were analysed using a dialectic constant comparison approach (Dick 2007). Three significant themes were identified. Mentor teachers’ understanding of their roles positioned pre-service teachers as either novices or alternatively as colleagues, and these had implications for the opportunities for learning that were then made available to the pre-service teachers. The mentor teacher’s beliefs about teaching as a practical craft, and how the mentor teachers judged a pre-service teacher’s “enthusiasm” were also analysed. Understanding the factors that guide teacher mentor approaches may inform future designs of mentoring and preservice teacher preparation programs.
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Background Acute respiratory illness, a leading cause of cough in children, accounts for a substantial proportion of childhood morbidity and mortality worldwide. In some children acute cough progresses to chronic cough (> 4 weeks duration), impacting on morbidity and decreasing quality of life. Despite the importance of chronic cough as a cause of substantial childhood morbidity and associated economic, family and social costs, data on the prevalence, predictors, aetiology and natural history of the symptom are scarce. This study aims to comprehensively describe the epidemiology, aetiology and outcomes of cough during and after acute respiratory illness in children presenting to a tertiary paediatric emergency department. Methods/design A prospective cohort study of children aged <15 years attending the Royal Children's Hospital Emergency Department, Brisbane, for a respiratory illness that includes parent reported cough (wet or dry) as a symptom. The primary objective is to determine the prevalence and predictors of chronic cough (>= 4 weeks duration) post presentation with acute respiratory illness. Demographic, epidemiological, risk factor, microbiological and clinical data are completed at enrolment. Subjects complete daily cough dairies and weekly follow-up contacts for 28(+/-3) days to ascertain cough persistence. Children who continue to cough for 28 days post enrolment are referred to a paediatric respiratory physician for review. Primary analysis will be the proportion of children with persistent cough at day 28(+/-3). Multivariate analyses will be performed to evaluate variables independently associated with chronic cough at day 28(+/-3). Discussion Our protocol will be the first to comprehensively describe the natural history, epidemiology, aetiology and outcomes of cough during and after acute respiratory illness in children. The results will contribute to studies leading to the development of evidence-based clinical guidelines to improve the early detection and management of chronic cough in children during and after acute respiratory illness.
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Background Substantial changing trends in women’s alcohol consumption show increased proportions women drinking at risky/ high risk levels. Not confined to the younger female population, these increases are also occurring in older female age groups (aged 35 and over), posing a set of risks differing to those of their male counterparts. However, little research investigates the influences behind these changing trends. The current research examined multiple level influences (i.e. cultural, social and psychosocial on women’s drinking across a range of age groups. Methods Semi-structured telephone interviews were conducted with thirty-five women (aged 18-55) residing in Australia. Interview development was guided by an adaptation of Bronfenbrenner’s Bioecological Model of Development to assess multiple areas of influences from cultural through to psychosocial (i.e. intra-individual). Each interview took approximately 1 hour to complete. Findings Bronfenbrenner’s Bioecological Model could account for multiple-level factors impacting women’s drinking with multidirectional influences interacting across each level. Cultural influences included gender roles and national identity. Exosystem influences (e.g. infrastructure, legislation, and media) and microsystem influences (e.g. drinking context, family, partner and peer influence) were clearly identified as impacting drinking behaviours. Finally, at the psychosocial level, attitudes and expectations around the disinhibiting effects of alcohol and social facilitation emerged as key influences. Discussion The outcomes indicated the importance of these influences as women’s alcohol-related attitudes and behaviours changed across a woman’s life span and across age cohorts. Future research will build on these initial findings in order to underpin targeted interventions of the key factors influencing women’s drinking.
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Background Changing trends in women's alcohol consumption have demonstrated that women, in both younger and older cohorts, are drinking at increased levels than previously. However, little research investigates these changing trends or the influences behind them. Aims The current research aims to identify influences on women's drinking across a range of age groups, with a focus on multiple level influences (i.e. cultural, social and psychosocial). Methods One hour semi-structured telephone interviews were conducted, in 2011, with 35 women (aged 18-55) residing in Australia. Interview development was guided by an adaptation of Bronfenbrenner's Bioecological Model of Development (BBMD) to assess multiple areas of influences from cultural through to psychosocial. Results Interview findings highlighted the existence of multiple levels of influence on women’s drinking and thus provided support for the BBMD framework. Cultural influences identified related to gender roles and national identity. Exosystem influences (e.g. legislation, infrastructure, and media) and Microsystem influences (e.g. immediate social networks) were also identified. A range of psychosocial factors, such as identity, normative influence and attitude were also found as influencing drinking behaviours. Finally, changes across a woman’s life span, and intergenerational differences, were Chronosystem constructs that also emerged as key influences. Discussion and conclusions This study has provided an in-depth understanding into the key factors, occurring across multiple levels of influence, impacting upon women's drinking across younger and older cohorts. The findings also highlight changes in alcohol-related attitudes and behaviours across a life span and across generations. Future research should extend upon these findings based on larger, quantitative studies based on representative samples. The findings do provide key insights into the influences that need to be addressed within targeted interventions.
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The 2012 OLT National Teaching Fellowship described in this report has mapped and analysed the complex and competing internal and external agencies impacting on the whole-of-curriculum design in contemporary higher education in Australia, particularly on degrees in Education with an emphasis on initial teacher education. The Fellowship was conducted at a time of both heightened public and political scrutiny of teacher education and the imposition of new nationally-consistent accreditation processes. This scrutiny culminated in a call by the previous Federal Government for TEQSA (Tertiary Education Quality Standards Agency) to conduct a comprehensive review of teacher education beginning in 2014 and the incoming Government announcing it will establish a short term ministerial advisory group to report on the “priority issue of improving teacher quality” (Pyne, 2013).
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Background Physiotherapists are a professional group with a high rate of attrition and at high risk of musculoskeletal disorders. The purpose of this investigation was to examine the physical activity levels and health-related quality of life of physiotherapists working in metropolitan clinical settings in an Australian hospital and health service. It was hypothesized that practicing physiotherapists would report excellent health-related quality of life and would already be physically active. Such a finding would add weight to a claim that general physical activity conditioning strategies may not be useful for preventing musculoskeletal disorders among active healthy physiotherapists, but rather, future investigations should focus on the development and evaluation of role specific conditioning strategies. Methods A questionnaire was completed by 44 physiotherapists from three inpatient units and three ambulatory clinics (63.7% response rate). Physical activity levels were reported using the Active Australia Survey. Health-related quality of life was examined using the EQ-5D instrument. Physical activity and EQ-5D data were examined using conventional descriptive statistics; with domain responses for the EQ-5D presented in a frequency histogram. Results The majority of physiotherapists in this sample were younger than 30 years of age (n = 25, 56.8%) consistent with the presence of a high attrition rate. Almost all respondents exceeded minimum recommended physical activity guidelines (n = 40, 90.9%). Overall the respondents engaged in more vigorous physical activity (median = 180 minutes) and walking (median = 135 minutes) than moderate exercise (median = 35 minutes) each week. Thirty-seven (84.1%) participants reported no pain or discomfort impacting their health-related quality of life, with most (n = 35,79.5%) being in full health. Conclusions Physical-conditioning based interventions for the prevention of musculoskeletal disorders among practicing physiotherapists may be better targeted to role or task specific conditioning rather than general physical conditioning among this physically active population. It is plausible that an inherent attrition of physiotherapists may occur among those not as active or healthy as therapists who cope with the physical demands of clinical practice. Extrapolation of findings from this study may be limited due to the sample characteristics. However, this investigation addressed the study objectives and has provided a foundation for larger scale longitudinal investigations in this field.
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Integration of small-scale electricity generators, known as Distributed Generation (DG), into the distribution networks has become increasingly popular at the present. This tendency together with the falling price of synchronous-type generator has potential to give the DG a better chance in participating in the voltage regulation process together with other devices already available in the system. The voltage control issue turns out to be a very challenging problem for the distribution engineers since existing control coordination schemes would need to be reconsidered to take into account the DG operation. In this paper, we propose a control coordination technique, which is able to utilize the ability of the DG as a voltage regulator, and at the same time minimizes interaction with other active devices, such as On-load Tap Changing Transformer (OLTC) and voltage regulator. The technique has been developed based on the concept of control zone, Line Drop Compensation (LDC), as well as the choice of controller's parameters. Simulations carried out on an Australian system show that the technique is suitable and flexible for any system with multiple regulating devices including DG.
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Technology is impacting on most elements of organisations today and workforce development professionals have been some of the leading proponents of embracing technologies and the benefits they offer. E-learning has emerged as at least a complementary offering to face-to-face training, and in some cases has totally replaced more traditional forms of workforce development. This chapter explores the use of learning technologies and the benefits and drawbacks of their use. In particular it focuses on further exploring the issue of a perceived lack of interaction in some e-learning offerings; a factor identified as critical to address in order to ensure effective e-learning. The chapter discusses the issues of interaction and social presence to address feelings of isolation and offers some key considerations for those considering integrating technology into workforce development.
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Significant investments in developing technological innovations have been made in the Australian beef industry but with low adoption rates. By modelling the key variables and their interactions in the innovation adoption process, this research seeks to demonstrate the complexity and dynamics of the process. This research uses causal loop modelling and develops a holistic model of the current innovation adoption system in the Australian beef industry to show the complexity of dynamic interactions among multiple variables. It is suggested that innovation adoption is such an extremely complex issue, and we need to shift our views on this issue from a paradigm of linear thinking to systems thinking. Innovation adoption is more likely to be enhanced based on a full understanding of the complexity and dynamics of the system as a whole. The paper demonstrates to practitioners and developers of innovation the multiple variables and interactions impacting innovation adoption.
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Single phase distributed energy resources (DERs) can cause voltage rise along distribution feeder and power imbalance among the phases. Usually transformer tap setting are used to mitigate voltage drop along feeders. However this can aggravate the voltage rise problem when DERs are connected. Moreover if the power generation in a phase is more than its load demand, the excess power in that phase will be fed back to the transmission network. In this paper, a unified power quality compensator (UPQC) has been utilized to alleviate the voltage quality excess power circulation problems. Through analysis and simulation results, the mode of operation of UPQC is highlighted. The proposals are validated through extensive digital computer simulation studies using PSCAD and MATLAB.
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Voltage drop at network peak hours is a significant power quality problem in Low Voltage (LV) distribution feeders. Recently, voltage rise due to high penetration of Photovoltaic cells (PVs) has been creating a new power quality problem during noon periods. In this paper, a voltage control strategy is proposed for the household installed PVs to regulate the voltage along the LV feeder. For this purpose, each PV is controlled to exchange reactive power with the grid. A droop control method is utilized to coordinate the reactive power exchange of each PV. The proposed method is a decentralized local voltage support since it is based on only local measurements and does not require any communication with other PVs. The required converter and filter structure and control algorithms are proposed to ensure the dynamic performance of the system. The study focuses on 3-phase PVs. The network is studied at network peak and off-peak periods, separately. The efficacy of the proposed voltage support concept is verified through numerical and dynamic analyses with MATLAB and PSCAD/EMTDC.