A dual inverter based supercapacitor direct integration scheme for wind energy conversion systems

This paper presents a new direct integration scheme for supercapacitors that are used to mitigate short term power fluctuations in wind power systems. The proposed scheme uses the popular dual inverter topology for grid connection as well as interfacing a supercapacitor bank. The dual inverter system is formed by cascading two 2-level inverters named as the “main inverter” and the “auxiliary inverter”. The main inverter is powered by the rectified output of a wind turbine coupled permanent magnet synchronous generator. The auxiliary inverter is directly connected to a super capacitor bank. This approach eliminates the need for an interfacing dc-dc converter for the supercapacitor bank and thus improves the overall efficiency. A detailed analysis on the effects of non-integer dynamically changing voltage ratio is presented. The concept of integrated boost rectifier is used to carry out the Maximum Power Point Tracking (MPPT) of the wind turbine generator. Another novel feature of this paper is the power reference adjuster which effectively manages capacitor charging and discharging at extreme conditions. Simulation results are presented to verify the efficacy of the proposed system in suppressing short term wind power fluctuations.

Identification of direct transcriptional targets of V600EBRAF/MEK signalling in melanoma

Oncogenic mutations in BRAF are common in melanoma and drive constitutive activation of the MEK/ERK pathway. To elucidate the transcriptional events downstream of V600EBRAF/MEK signalling we performed gene expression profiling of A375 melanoma cells treated with potent and selective inhibitors of V600EBRAF and MEK (PLX4720 and PD184352 respectively). Using a stringent Bayesian approach, we identified 69 transcripts that appear to be direct transcriptional targets of this pathway and whose expression changed after 6 h of pathway inhibition. We also identified several additional genes whose expression changed after 24 h of pathway inhibition and which are likely to be indirect transcriptional targets of the pathway. Several of these were confirmed by demonstrating their expression to be similarly regulated when BRAF was depleted using RNA interference, and by using qRT-PCR in other BRAF mutated melanoma lines. Many of these genes are transcription factors and feedback inhibitors of the ERK pathway and are also regulated by MEK signalling in NRAS mutant cells. This study provides a basis for understanding the molecular processes that are regulated by V600EBRAF/MEK signalling in melanoma cells.

Muramidases found in the foregut microbiome of the Tammar wallaby can direct cell aggregation and biofilm formation

We describe here the role of muramidases present in clones of metagenomic DNA that result in cell aggregation and biofilm formation by Escherichia coli. The metagenomic clones were obtained from uncultured Lachnospiraceae-affiliated bacteria resident in the foregut microbiome of the Tammar wallaby. One of these fosmid clones (p49C2) was chosen for more detailed studies and a variety of genetic methods were used to delimit the region responsible for the phenotype to an open reading frame of 1425 bp. Comparative sequence analysis with other fosmid clones giving rise to the same phenotype revealed the presence of muramidase homologues with the same modular composition. Phylogenetic analysis of the fosmid sequence data assigned these fosmid inserts to recently identified, but uncultured, phylogroups of Lachnospiraceae believed to be numerically dominant in the foregut microbiome of the Tammar wallaby. The muramidase is a modular protein containing putative N-acetylmuramoyl--alanine amidase and an endo-β-N-acetylglucosaminidase catalytic module, with a similar organization and functional properties to some Staphylococcal autolysins that also confer adhesive properties and biofilm formation. We also show here that the cloned muramidases result in the production of extracellular DNA, which appears to be the key for biofilm formation and autoaggregation. Collectively, these findings suggest that biofilm formation and cell aggregation in gut microbiomes might occur via the concerted action of carbohydrate-active enzymes and the production of extracellular DNA to serve as a biofilm scaffold.

Prevention of Pollution of the Marine Environment from Vessels : The Potential and Limits of the International Maritime Organisation

--Critically discusses the role of International Maritime Organization (IMO) in the protection of the marine environment --Presents a clear, updated, concise and critical overview of the IMO marine environmental legal instruments --A fresh outlook on the north-south tensions in the IMO marine environmental discourses --Critically examines the principle of common but differentiated responsibilities in the context of IMO This book examines the role of The International Maritime Organization (IMO) in the prevention and control of pollution of the marine environment from vessels with a particular reference to the current north-south tensions regarding the strategy for combating climate change in the maritime sector as well as the prevention of marine pollution from the ship-breaking industry. The IMO, a United Nations specialized agency, has been entrusted with the duty to provide machinery for cooperation among governments for the prevention and control of pollution of the marine environment from vessels. The organization is responsible for drafting legal instruments as well as for facilitating technical cooperation for the protection of the marine environment. Although IMO legal instruments are mainly targeted at the prevention of pollution of the marine environment from vessels, there is a trend towards a liberal interpretation of this, and the organization has expanded its work to areas like shipbreaking, which is essentially a land-based industry.

Exact parametric confidence intervals for Bland-Altman limits of agreement

Purpose The previous literature on Bland-Altman analysis only describes approximate methods for calculating confidence intervals for 95% Limits of Agreement (LoAs). This paper describes exact methods for calculating such confidence intervals, based on the assumption that differences in measurement pairs are normally distributed. Methods Two basic situations are considered for calculating LoA confidence intervals: the first where LoAs are considered individually (i.e. using one-sided tolerance factors for a normal distribution); and the second, where LoAs are considered as a pair (i.e. using two-sided tolerance factors for a normal distribution). Equations underlying the calculation of exact confidence limits are briefly outlined. Results To assist in determining confidence intervals for LoAs (considered individually and as a pair) tables of coefficients have been included for degrees of freedom between 1 and 1000. Numerical examples, showing the use of the tables for calculating confidence limits for Bland-Altman LoAs, have been provided. Conclusions Exact confidence intervals for LoAs can differ considerably from Bland and Altman’s approximate method, especially for sample sizes that are not large. There are better, more precise methods for calculating confidence intervals for LoAs than Bland and Altman’s approximate method, although even an approximate calculation of confidence intervals for LoAs is likely to be better than none at all. Reporting confidence limits for LoAs considered as a pair is appropriate for most situations, however there may be circumstances where it is appropriate to report confidence limits for LoAs considered individually.

Combustion analysis of microalgae methyl ester in a common rail direct injection diesel engine

In this study, the biodiesel properties and effects of blends of oil methyl ester petroleum diesel on a CI direct injection diesel engine is investigated. Blends were obtained from the marine dinoflagellate Crypthecodinium cohnii and waste cooking oil. The experiment was conducted using a four-cylinder, turbo-charged common rail direct injection diesel engine at four loads (25%, 50%, 75% and 100%). Three blends (10%, 20% and 50%) of microalgae oil methyl ester and a 20% blend of waste cooking oil methyl ester were compared to petroleum diesel. To establish suitability of the fuels for a CI engine, the effects of the three microalgae fuel blends at different engine loads were assessed by measuring engine performance, i.e. mean effective pressure (IMEP), brake mean effective pressure (BMEP), in cylinder pressure, maximum pressure rise rate, brake-specific fuel consumption (BSFC), brake thermal efficiency (BTE), heat release rate and gaseous emissions (NO, NOx,and unburned hydrocarbons (UHC)). Results were then compared to engine performance characteristics for operation with a 20% waste cooking oil/petroleum diesel blend and petroleum diesel. In addition, physical and chemical properties of the fuels were measured. Use of microalgae methyl ester reduced the instantaneous cylinder pressure and engine output torque, when compared to that of petroleum diesel, by a maximum of 4.5% at 50% blend at full throttle. The lower calorific value of the microalgae oil methyl ester blends increased the BSFC, which ultimately reduced the BTE by up to 4% at higher loads. Minor reductions of IMEP and BMEP were recorded for both the microalgae and the waste cooking oil methyl ester blends at low loads, with a maximum of 7% reduction at 75% load compared to petroleum diesel. Furthermore, compared to petroleum diesel, gaseous emissions of NO and NOx, increased for operations with biodiesel blends. At full load, NO and NOx emissions increased by 22% when 50% microalgae blends were used. Petroleum diesel and a 20% blend of waste cooking oil methyl ester had emissions of UHC that were similar, but those of microalgae oil methyl ester/petroleum diesel blends were reduced by at least 50% for all blends and engine conditions. The tested microalgae methyl esters contain some long-chain, polyunsaturated fatty acid methyl esters (FAMEs) (C22:5 and C22:6) not commonly found in terrestrial-crop-derived biodiesels yet all fuel properties were satisfied or were very close to the ASTM 6751-12 and EN14214 standards. Therefore, Crypthecodinium cohnii- derived microalgae biodiesel/petroleum blends of up to 50% are projected to meet all fuel property standards and, engine performance and emission results from this study clearly show its suitability for regular use in diesel engines.

Setting limits to laughter : university teaching and the boundaries of humour

This paper forms one part of a broadly-based study into the use of humour within tertiary teaching. One theme to emerge from semi-structured, in-depth interviews with university academics concerns the setting of boundaries to the appropriate use of humour within lectures and tutorials. Following the ‘benign violations’ theory of humour—wherein, to be funny, a situation/statement must be some kind of a social violation, that violation must be regarded as relatively benign, and the two ideas must be held simultaneously—this paper suggests that the willingness of academics to use particular types of humour in their teaching revolves around the complexities of determining the margins of the benign. These margins are shaped in part by pedagogic limitations, but also by professional delimitations. In terms of limitations, the boundaries of humour are set by the academic environment of the university, by the characteristics of different cohorts of students, and by what those students are prepare to laugh at. In terms of delimitations—where humour choice is moderated, not by the possibility of immediate laughter, but rather by the consequences of that choice—academic seniority and security play a large role in determining what kinds of humour will be used, and where boundaries are to be set. The central conclusion here is that formal maxims of humour use—‘Never tease students’, ‘Don’t joke about potentially sensitive issues’—fail to account for the complexity of teaching relationships, for the differences between student cohorts, and for the talents and standing of particular teachers.

What Costs Accountability? Financial Accountability, Mission and Fundraising in Nonprofits

Although greater calls for accountability have been articulated by academics, policy makers and donors in the recent years, a stream of thought has been questioning where the giving of an account should stop. In conveying the limits to the giving of an account (Messner, 2009) and associated transparency (Roberts, 2009), critical accounting scholars have also pointed to as yet unresolved contradictions intrinsic to accountability (McKernan, 2012), especially when it comes to be operationalised (Joannides, 2012). The impact of accountability's discharging on nonprofits' strategy or operations has to date been underexplored (Dhanni & Connelly, 2012; Tucker & Parker, 2013). Accordingly, this chapter seeks to contribute to this body of literature on the consequences of accountability on fundraising strategies in nonprofits, questioning whether accountability practice may hamper the effectiveness of the nonprofit sector by restraining the fundraising profession. Our chapter seeks to fill a dual theoretical gap. Firstly, only a number of publications have investigated the interplay between accountability and the making of organisational strategy (Parker, 2002, 2003b, 2011, 2012, 2013; Tucker & Parker, 2013). Therefore, we seek to fill a theoretical gap as to the impact of accountability on the conduct of straegic operations. By questioning whether accountability hampers fundraising strategy in non-profits we are also contributing to the literature balancing accountability and the mission. In this literature, it appears that money and the mission are often conflictual, financial managers being often seen by mission advocates as guardians shielding organisational resources (Chiapello, 1993, 1998; Lightbody, 2000, 2003). Another approach shows that making nonprofits accountable to capital and multiple stakeholders (donors, public authorities) leaders to changes in organisational culture (O'Dwyer & Unerman, 2007; Unerman & Bennett, 2004; Underman & O'Dwyer, 2006a, 2006b, 2008). By examining a small number of cases we show how accountability practices result in fundraising adapting and adjusting under such external pressures and constraints. We also show accountability systems may have a direct impact on the conduct of strategic operations, which might hamper mission conduct.

Review-evaluating the molecular assays for measuring the oxidative potential of particulate matter

Several cell-free assays are currently used to quantify and detect the Reactive Oxygen Species (ROS). All of them have certain limitations, do not provide direct comparison of results and, to date, none of these assays have been acknowledged as the most suitable acellular assay and none has yet been adopted for investigation of potential PM toxicity. These assays include DTT, ascorbic acid, DCFHDA and PFN assays which have been used in measurements of the particles generated from various combustion sources such as diesel engine, wood smoke (or biomass burning) and cigarette smoke, as well as for outdoor measurements. All the probes use different units for expressing redox properties of PM. Also, their reactivity is being triggered by different types of ROS. This limits the direct comparison of the results that are reporting the toxicity of the same aerosol type measured with various probes. This study is evaluating and comparing the various assays in order to develop deeper understanding of their capabilities, selectivity as well as improve understanding of the underlying chemical mechanisms. Keywords: DTT, DCFH-DA, PFN, BPEA-nit, Ascorbic acid, oxidative potential

Hydrostratigraphic analysis of the MADE site with full-resolution GPR and direct-push hydraulic profiling

Full-resolution 3D Ground-Penetrating Radar (GPR) data were combined with high-resolution hydraulic conductivity (K) data from vertical Direct-Push (DP) profiles to characterize a portion of the highly heterogeneous MAcro Dispersion Experiment (MADE) site. This is an important first step to better understand the influence of aquifer heterogeneities on observed anomalous transport. Statistical evaluation of DP data indicates non-normal distributions that have much higher similarity within each GPR facies than between facies. The analysis of GPR and DP data provides high-resolution estimates of the 3D geometry of hydrostratigraphic zones, which can then be populated with stochastic K fields. The lack of such estimates has been a significant limitation for testing and parameterizing a range of novel transport theories at sites where the traditional advection-dispersion model has proven inadequate.

The limits to public service : rural communities, professional families, and work mobility

Australia faces an ongoing challenge recruiting professionals to staff essential human services in rural and remote communities. This paper identifies the private limits to the implicit service contract between professions and such client populations. These become evident in how private solutions to competing priorities within professional families inform their selective mobility and thus create the public problem for such communities. The paper reports on a survey of doctors, nurses, teachers and police with responsibility for school-aged children in Queensland that plumbed the strength of neoliberal values in their educational strategy and their commitment to the public good in career decisions. The quantitative analysis suggested that neoliberal values are not necessarily opposed to a commitment to the public good. However, the qualitative analysis of responses to hypothetical career opportunities in rural and remote communities drew out the multiple intertwined spatial and temporal limits to such public service, highlighting the priority given to educational strategy in these families’ deliberations. This private/public nexus poses a policy problem on multiple institutional fronts.

Improved fabrication of melt electrospun tissue engineering scaffolds using direct writing and advanced electric field control

Direct writing melt electrospinning is an additive manufacturing technique capable of the layer-by-layer fabrication of highly ordered 3d tissue engineering scaffolds from micron-diameter fibres. The utility of these scaffolds, however, is limited by the maximum achievable height of controlled fibre deposition, beyond which the structure becomes increasingly disordered. A source of this disorder is charge build-up on the deposited polymer producing unwanted coulombic forces. In this study we introduce a novel melt electrospinning platform with dual voltage power supplies to reduce undesirable charge effects and improve fibre deposition control. We produced and characterised several 90° cross-hatched fibre scaffolds using a range of needle/collector plate voltages. Fibre thickness was found to be sensitive only to overall potential and invariant to specific tip/collector voltage. We also produced ordered scaffolds up to 200 layers thick (fibre spacing 1 mm, diameter 40 μm) and characterised structure in terms of three distinct zones; ordered, semi-ordered and disordered. Our in vitro analysis indicates successful cell attachment and distribution throughout the scaffolds, with little evidence of cell death after seven days. This study demonstrates the importance of electrostatic control for reducing destabilising polymer charge effects and enabling the fabrication of morphologically suitable scaffolds for tissue engineering.

Antidepressant direct-to-consumer prescription drug advertising and public stigma of depression : the mediating role of perceived prevalence of depression

This study examines whether memory of antidepressant direct-to-consumer (DTC) prescription drug advertising is associated with the public stigma attached to depression. Results indicate that those who better remember antidepressant DTC ads tend to have a higher perceived prevalence of depression (i.e., more people suffer from depression). And, the perceived prevalence of depression is inversely associated with the public stigma toward depression. That is, those who have a higher perceived prevalence of depression report that they are more supportive of and comfortable with people who have depression. The results suggest that the perceived prevalence of depression is a mediating variable that accounts for the relationship between memory of antidepressant DTC ads and the public stigma toward depression. The implications and limitations of the study, as an exploratory investigation, are discussed.

Lecturing and the limits of laughter

The literature on humour in teaching frequently defaults to a series of maxims about how it can be used most appropriately: ‘Never tease students', ‘Don't joke about sensitive issues', ‘Never use laughter for disciplinary purposes'. This paper outlines recent research into the boundaries of humour-use within teacher education, which itself forms one part of a large scale, broadly-based study into the use of humour within tertiary teaching. This particular part of the research involves semi-structured, in-depth interviews with university academics. Following the ‘benign violations' theory of humour - wherein, to be funny, a situation/statement must be some kind of a social violation, that violation must be regarded as relatively benign, and the two ideas must be held simultaneously - this paper suggests that the willingness of academics to use particular types of humour in their teaching revolves around the complexities of determining the margins of ‘the benign'. These margins are shaped in part by pedagogic limitations, but also by professional delimitations. In terms of limitations, the boundaries of humour are set by the academic environment of the university, by the characteristics of different cohorts of students, and by what those students are prepare to laugh at. In terms of delimitations, most academics are prepared to tease their student, and many are prepared to use laughter as a form of discipline, however their own humour orientation, academic seniority, and employment security play a large role in determining what kinds of humour will be used, and where boundaries will be set. The central conclusion here is that formal maxims of humour provide little more than vague strategic guidelines, largely failing to account for the complexity of teaching relationships, for the differences between student cohorts, and for the talents and standing of particular teachers.