1522 research outputs found
Sort by
The Effectiveness and Feasibility of Using Ochre as a Soil Amendment to Sequester Dissolved Reactive Phosphorus in Runoff
Get PDFIncidental losses of dissolved reactive phosphorus
(DRP) to a surface waterbody originate from
direct losses during land application of fertilizer, or
where a rainfall event occurs immediately thereafter.
Another source is the soil. One way of immobilising
DRP in runoff before discharge to a surface waterbody,
is to amend soil within the edge of field area with a
high phosphorus (P) sequestration material. One such
amendment is iron ochre, a by-product of acid mine
drainage. Batch experiments utilising two grassland
soils at two depths (topsoil and sub-soil), six ochre
amendment rates (0, 0.15, 1.5, 7.5, 15 and 30 g kg−1
mass per dry weight of soil) and five P concentrations
(0, 5, 10, 20 and 40 mg L−1) were carried out. A
proportional equation, which incorporated P sources
and losses, was developed and used to form a
statistical model. Back calculation identified optimal
rates of ochre amendment to soil to ameliorate a
specific DRP concentration in runoff. Ochre amendment
of soils (with no further P inputs) was effective
at decreasing DRP concentrations to acceptable
levels. A rate of 30 g ochre kg−1 soil was needed to
decrease DRP concentrations to acceptable levels for
P inputs of ≤10 mg L−1, which represents the vast
majority of cases in grassland runoff experiments.
However, although very quick and sustained metal
release above environmental limits occurred, which
makes it unfeasible for use as a soil amendment to
control P release to a waterbody, the methodology
developed within this paper may be used to test the
effectiveness and feasibility of other amendments
Pump dependence of the dynamics of quantum dot based waveguide absorbers
Get PDFThe nonlinear two stage recovery of quantum dot based reverse-biased waveguide absorbers is
investigated experimentally and analytically as a function of the initial ground state occupation
probability of the dot. The latter is controlled experimentally by the pump pulse power. The
slow stage of the recovery is exponential and its basic timescale is independent of pump power.
The fast stage of the recovery is a logistic function which we analyze in detail. The relative
strength of slow to fast components is highlighted and the importance of higher order
absorption processes at the highest pump level is demonstrated
Riordan-Bernstein Polynomials, Hankel Transforms and Somos Sequences
Get PDFUsing the language of Riordan arrays, we define a notion of generalized Bernstein polynomials which are defined as elements of certain Riordan arrays. We characterize the general elements of these arrays, and examine the Hankel transform of the row sums and the first columns of these arrays. We propose conditions under which these Hankel transforms possess the Somos- property.
We use the generalized Bernstein polynomials to define generalized B\'ezier curves which can provide a visualization of the effect of the defining Riordan array
Towards Developing a Research Roadmap for Service Innovation in Ireland
Get PDFThe systematic development, design and testing of new and/or improved service offerings, processes and business models, i.e. service innovation, represents a timely and relevant growth area transcending European and Irish innovation and socio-economic recovery strategies. However, research into the development and practice of service innovation vis-àvis product innovation, is a relatively emerging domain and is at best characterised as emerging and fragmented. The existing body of research knowledge is derived largely from product innovation and fails to provide concrete processes by which to embed service
innovation at the firm-level. Hindered by a lack of integrative theoretical and supportive framework models, success rates for service innovation are low and there is a lack of tailored instruments and tools for planning, designing and developing service innovations which has
significant implications in terms of industry awareness, deployment and impact. Additionally, it has been well documented that innovation policy and supports have not been well attuned to service innovation, particularly as current framework mechanisms are predominantly
biased towards technological and product innovation.
Reflective of this, The European Expert Panel on Service Innovation has recently identified that the key underlying challenge facing Europe is the development of a coherent policy framework that enables and supports the transformative and horizontal cross-cutting economic potential of service innovation. Therefore, to underpin Ireland’s emerging service innovation agenda, informed research is required to address the underlying challenges that exist at policy, research and industry levels. Through a combination of desk research and semi-structured interviews with key stakeholders within Ireland’s innovation ecosystem, a range of challenges and action points relating to Ireland’s engagement and potential to exploit service innovation at policy, practice, research and education levels are surfaced. Moreover, the study subsequently proffers a responsive research roadmap, informed by EU best practice,as a starting point to stimulate further research developments within the field. Accordingly, the research impacts and has implications at various stakeholder levels, most notably in terms
of informing policy development through evidence based research, prioritising applied and academic research gaps and challenges and also signals the need to prioritise industry awareness and practice of the discipline
The Effect of a six month low-carbohydrate diet on the biomarkers of bone health in pre- and post-menopausal women: a randomised control crossover trial
Get PDFWith increasing levels of obesity, the low-carbohydrate diet has again become popular as a weight loss method. While weight loss through consumption of a low carbohydrate diet has been well researched, there is contradictory evidence regarding its effect on bone health. The effect of this diet on bone health for greater than 12 weeks and in menopausal women is relatively unknown. The aim of this study was to assess the effect of a low-carbohydrate diet consumed over 24 weeks on biomarkers of bone health in pre- and postmenopausal females. Following ethical approval, informed consent and screening, 24 subjects (13 pre-menopausal; 11 postmenopausal) were randomly assigned to a control or low-carbohydrate diet group for 24 weeks. Subjects were then crossed over to the alternative dietary regimen for 24 weeks. Blood and urine samples taken at week 12, 24, 36 and 48 were analysed for biomarkers of bone resorption and formation using ELIZA. Urine pH was measured and a 3 day food diary analysed using CompEat™. Data was analysed for treatment and carryover effects. Where carryover effects were evident analysis was completed on 12 subjects only. Consuming the low-carbohydrate diet resulted in a significant decrease in energy (P = 0.017) and carbohydrate (P = 0.001) but protein intake did not change (P = 0.264). There was a significant reduction in weight (P = 0.000), waist circumference (P = 0.000), diastolic blood pressure (P = 0.021), K (P = 0.047) and Mg (P = 0.005). Increased PRAL (P = 0.004), NTx (P = 0.019) and IGF-1 (P = 0.043) were observed in the low-carbohydrate period versus the control. Several other parameters changed over 12 weeks of the low-carbohydrate diet but not over the 24 week period. There were significant decreases in fibre, Ca and Na during the low carbohydrate diet over 12 weeks and increases in vitamin D and urinary Ca. There were no significant differences in any other parameters measured. Weight loss due to a low-carbohydrate diet caused significant changes in nutrient intake with some aspects being conducive to bone health but other aspects perhaps detrimental to bone. Increased bone resorption observed in this study without concomitant increased bone formation suggests this diet could cause poor bone health over time
Managing the Formation and Interaction of Groups within Emerging Social Networks
Get PDFThe formation, evolution and management of groups within modern social networks pose significant challenges and opportunities. Challenges arise from a combination of ubiquitous connectivity coupled with innovative and inexpensive cloud infrastructure, yielding new usage patterns which push existing service architectures, management infrastructure and technology stacks to their limits. Opportunities for remedying this situation arise from re-thinking the formation and management of social media groups and introducing innovative models, notations, algorithms and implementation strategies. To this end, this work analyses emerging group formation and interaction patterns, applies new approaches to current prominent protocols and evaluates resultant behavior and performance characteristics. This analysis is applied to more sophisticated usage patterns; models, notations and algorithms are devised to exibly support emerging scenarios, and specific implementations are discussed and analysed. Applying Policy Based Network Management principles to manage the formation of, and interaction within, groups is demonstrated to be viable, particularly if coupled with emerging technology stacks. An innovative architecture model is evolved, which can exibly match the performance and scalability requirements likely to emerge in next generation social network platforms. In addition, an approach to policy language development is proposed and demonstrated, capitalising on recent innovations in scripting language design and implementation. This is shown to deliver a considerably simplified, more exible and more expressive alternative to current policy languages, and offers significant scope for further research and innovation
Riordan arrays and the LDU decomposition of symmetric Toeplitz plus Hankel matrices
Get PDFWe examine a result of Basor and Ehrhardt concerning Hankel and Toeplitz plus Hankel matrices, within the context of the Riordan group of lower-triangular matrices. This allows us to determine the decomposition of certain symmetric Toeplitz plus Hankel matrices. We also determine the generating functions and Hankel transforms of associated sequences
A Note on Three Families of Orthogonal Polynomials defined by Circular Functions, and Their Moment Sequences
Get PDFUsing the language of exponential Riordan arrays, we study three distinct families of orthogonal polynomials defined by trigonometric functions. We study the moment sequences of theses families, finding continued fraction expressions for their generating functions, and calculate the Hankel transforms of these moment sequences. Results related to the Euler or zigzag numbers, as well as the generalized Euler or Springer numbers, are found. In addition, we characterize the Dowling numbers as moments of a family of orthogonal polynomials
Doctoral Education at the ‘Eye’ of the Perfect Storm
Get PDFThere is evidence of change in the context in which doctoral education is developing; in the need for research-based responses to the grand challenges facing society; and in the employability of the PhD. Key features of these changes identified by the EUA and the IUA, include quality research training, inter-disciplinarity, partnerships with industry, and a mentality of innovation. Researchers need to develop cross-disciplinary thinking in order to work with someone else within the discipline, outside the discipline or in practice.
Therefore, PhD research has to contribute in different ways, and the researcher must develop new and different skills and perspectives. In particular, the researcher must come to see that to explore and exploit the value latent in their thesis research, it may be necessary to interact directly with researchers from other disciplines and, together, to progress from multi-disciplinary interaction to interdisciplinary outcomes.
The overall objective of the study was to explore how distinctive learning spaces can be built into doctoral teaching-learning environments (TLEs) in order to create opportunities for cross-disciplinary transformative learning to occur. More precisely, the aim was to identify how to create doctoral learning spaces that enable one to think beyond one’s own discipline, to communicate across traditional disciplinary divides, in order to exploit the potential in the thesis research while not diluting the (disciplinary) core of the research.
Literatures that inform this study include EUA, IUA and other universities discussion papers and monographs; Entwistle (2009, 2008), Donald (2002), Land (2004, 2005, King (2005, 2009) and Graham (2011).
The TCD/UCD Innovation Academy is the context for this case study. Methods used included a student questionnaire, interviews, an end-of-programme 360°evaluation, and document analysis.
The research results identify aspects of the learning space that impact on student’s ability to communicate across the disciplines, and to move from ‘intra-disciplinary’, to ‘multi-disciplinary’ to ‘inter-disciplinary’ ways of thinking and practicing.
Further steps are identified for developing Academy programme TLE and also suggestions for initiatives within and between faculties in both universities. The need for more research into creating cross-disciplinary doctoral learning spaces in general is identified