NUI Maynooth Eprint Archive
Not a member yet
18159 research outputs found
Sort by
Data-based hydrodynamic modelling of a fixed OWC wave energy converter
No full textSystem identification (SI) techniques represent an alternative strategy to provide the hydrodynamic
model of oscillating water column (OWC) devices, compared to relatively laborious, and potentially inaccurate,
model determination from first principles. In particular,
the assumption of small variations about equilibrium of
the water column, combined with difficulties in calculating
added mass, make the linear boundary-element modelling
of OWCs particularly challenging. With SI, the parameters
of the model are obtained, by minimizing a cost function,
from input-output data. Even though OWC modelling
typically features physics-based methods, such as linear
potential theory or computational fluid dynamics (CFD), SI
has already been successfully employed in the modelling
of other wave energy devices. The main advantage of SI
is its simplicity, as well as its potential validity range,
where the dynamic model is valid over the range for
which the identification data was recorded. This work aims
to develop a data-based hydrodynamic model of a single
chamber OWC wave energy converter by employing system
identification. Real wave tank (RWT) data of a scaled model
are gathered from the narrow tank experimental facility at
Dundalk Institute of Technology (DkIT). Particular attention is paid to the selection of suitable input signals for the
experimental campaign, in order to ensure that the model
is subjected to the entire range of equivalent frequencies,
and amplitudes, over which model validity is required
Focused wave interactions with floating structures: A blind comparative study
No full textThe paper presents results from the Collaborative Computational Project in Wave Structure Interaction (CCP-WSI)
Blind Test Series 2. Without prior access to the physical data, participants, with numerical methods ranging from
low-fidelity linear models to fully nonlinear Navier-Stokes (NS) solvers, simulate the interaction between focused
wave events and two separate, taut-moored, floating structures: a hemispherical-bottomed cylinder and a cylinder
with a moonpool. The ‘blind’ numerical predictions for heave, surge, pitch and mooring load, are compared against
physical measurements. Dynamic time warping is used to quantify the predictive capability of participating methods.
In general, NS solvers and hybrid methods give more accurate predictions; however, heave amplitude is predicted
reasonably well by all methods; and a WEC-Sim implementation, with CFD-informed viscous terms, demonstrates
comparable predictive capability to even the stronger NS solvers. Large variations in the solutions are observed
(even among similar methods), highlighting a need for standardisation in the numerical modelling of WSI problems
Assessing the validity of regular wave theory in a short physical wave flume using particle image velocimetry
No full textThe modelling of ocean waves is an integral part of coastal and offshore engineering. Both theoretical and
experimental modelling methods are available and are commonly used in support of each other. In particular,
due to the difficulty in measuring the velocity throughout the water column, the wave kinematics are often
derived, by means of wave theory, from a measurement of the free surface elevation. However, wave theory is
often based upon idealistic conditions, such as infinite spatial domains and time lengths. The question therefore
arises, how well are the wave kinematics in an experimental wave tank described by wave theory? The present
paper compares theoretical solutions against experimental data, for the free surface elevation and the velocity
throughout the water column, to assess the ability of Stokes’ wave theory to describe the kinematics of regular
waves in a short, physical, wave flume. Experimentally, the free surface elevation is measured with a set of
resistive wave probes, while wave kinematic data is acquired with particle image velocimetry (PIV). For this
study, ten different regular waves, of varying steepness, are generated in a 35 m long and 0.7 m deep wave flume.
The theoretical solutions are computed based on Stokes 2nd order wave theory. The presented results show error
values of the order of 10–20%, indicating validity of the employed wave theory as a function of the reflection
coefficient achieved in the physical wave flume. These result highlight the potential inaccuracies incurred in any
wave tank if the wave theory is used to derive the kinematics from the free surface elevation without having
detailed knowledge of the reflection characteristics at the point of interest in the tank
Hallmarks of Basidiomycete Soft- and White-Rot in Wood-Decay -Omics Data of Two Armillaria Species
No full textWood-decaying Basidiomycetes are among the most efficient degraders of plant cell walls,
making them key players in forest ecosystems, global carbon cycle, and in bio-based industries.
Recent insights from -omics data revealed a high functional diversity of wood-decay strategies,
especially among the traditional white-rot and brown-rot dichotomy. We examined the mechanistic
bases of wood-decay in the conifer-specialists Armillaria ostoyae and Armillaria cepistipes using transcriptomic and proteomic approaches. Armillaria spp. (Fungi, Basidiomycota) include devastating
pathogens of temperate forests and saprotrophs that decay wood. They have been discussed as
white-rot species, though their response to wood deviates from typical white-rotters. While we observed an upregulation of a diverse suite of plant cell wall degrading enzymes, unlike white-rotters,
they possess and express an atypical wood-decay repertoire in which pectinases and expansins are
enriched, whereas lignin-decaying enzymes (LDEs) are generally downregulated. This combination of wood decay genes resembles the soft-rot of Ascomycota and appears widespread among
Basidiomycota that produce a superficial white rot-like decay. These observations are consistent
with ancestral soft-rot decay machinery conserved across asco- and Basidiomycota, a gain of efficient
lignin-degrading ability in white-rot fungi and repeated, complete, or partial losses of LDE encoding
gene repertoires in brown- and secondarily soft-rot fungi
DDX3X Links NLRP11 to the Regulation of Type I Interferon Responses and NLRP3 Inflammasome Activation
No full textTight regulation of inflammatory cytokine and interferon (IFN) production in innate immunity is pivotal for optimal control of pathogens and avoidance of immunopathology. The human Nod-like receptor (NLR) NLRP11 has been shown to regulate type I IFN and pro-inflammatory cytokine responses. Here, we identified the ATP-dependent RNA helicase DDX3X as a novel binding partner of NLRP11, using co-immunoprecipitation and LC-MS/MS. DDX3X is known to enhance type I IFN responses and NLRP3 inflammasome activation. We demonstrate that NLRP11 can abolish IKKϵ-mediated phosphorylation of DDX3X, resulting in lower type I IFN induction upon viral infection. These effects were dependent on the LRR domain of NLRP11 that we mapped as the interaction domain for DDX3X. In addition, NLRP11 also suppressed NLRP3-mediated caspase-1 activation in an LRR domain-dependent manner, suggesting that NLRP11 might sequester DDX3X and prevent it from promoting NLRP3-induced inflammasome activation. Taken together, our data revealed DDX3X as a central target of NLRP11, which can mediate the effects of NLRP11 on type I IFN induction as well as NLRP3 inflammasome activation. This expands our knowledge of the molecular mechanisms underlying NLRP11 function in innate immunity and suggests that both NLRP11 and DDX3X might be promising targets for modulation of innate immune responses
Passivity considerations in robust spectral-based controllers for wave energy converters
No full textRecent developments in wave energy converter (WEC) control include robust control strategies, which admit a level of uncertainty in the model
description. Then, for the application of such control
methods, some knowledge of the uncertainty bounds is
initially required. As recently shown in the literature,
some approaches for uncertainty quantification can lead
to scenarios where, due to uncertainty quantification,
the passivity of the WEC model is not guaranteed
and, consequently, the optimisation required to capture
most of the available energy cannot be successfully
performed. Such approaches can generate significant
performance losses. Thus, in this study, a passivisation
methodology to extend the applicability of spectral
control approaches is presented. The benefit of the
presented approach, relative to previous results, is
shown with an application case
Sharing our Stories: From Durban to Dublin, Ireland: Lucky Khambule tells his story...
No full textHelen Fallon, Deputy Librarian at Maynooth University meets African people living in Ireland. Through
sharing stories we can reach a better understanding of each other and our hopes and dreams
The ‘Social’ can really work in Mental Health Social Work: A Critical Review of how the understanding of recovery has evolved and converged towards the skillset of Social Work
No full textThe idea of recovery within Irish mental health
services have undergone dramatic changes.
Historically, the person was considered the
problem and in need of treatment. Many people
using services experienced institutionalisation.
Recovery is now seen as a personalised journey
where people are influential in determining their
treatment plan. However, these aspirations
regarding recovery have continued to face
challenges in service culture. One reason is
the multiple perspectives involved in recovery orientated services. This has resulted in different
competing ideas in how recovery should
be experienced and delivered in practice.
Concurrently, the changing understanding of
recovery has increasingly converged towards
the perspective of the social worker. Now,
there is a need for a philosophy which is not
just a personalised journey, but also one which
incorporates a social recovery perspective.
Ultimately, the role of social work can lead to an
increased focus on agency, empowerment, and
a sense of belonging moving forward
Disputes in the Irish college, Douai (1594–1614)
No full textBy the late sixteenth century, Irish demand for seminary places was sufficient to warrant the establishment of a dedicated Irish college in Lisbon (1590). This was followed by foundations in Salamanca (1592), Douai (1594) and elsewhere. The great majority were administered by the Society of Jesus, whose Irish members were generally Old English, a term denoting descendants of the twelfth-century Anglo-Norman settlers. Old English Jesuit domination of Irish colleges occasioned accusations of discrimination against students of Gaelic family backgrounds, with the students seeking redress from the secular authorities. The Irish college in Douai was not formally administered by the Jesuits, but its founder, Christopher Cusack, collaborated closely with the Society. Accusations against him of anti-Gaelic bias emerged in the 1600s, coincidental with the arrival of large numbers of Gaelic Irish refugees in Flanders at the end of the Nine Years War (1594–1603). Ethnic tensions and financial difficulties all but put paid to the college in the 1620s
Mainstreaming restorative justice and therapeutic jurisprudence through higher education.
No full textCriminal justice reformers spill much ink in explicating the benefits and challenges of restorative justice and therapeutic jurisprudence.1
These writings show that our fields have much in common. They incorporate normative frameworks and methodologies through which to express their values in criminal justice.2
In doing so, they challenge modern justice to become more humane.3 Restorative justice asks criminal justice practitioners and legal professionals to involve
people in identifying their needs, repairing harm and building strong relationships, rather than imposing a proportionate amount of harm on perpetrators.4
Therapeutic jurisprudence recognizes that legal rules,
procedures, and actors have pro-therapeutic or anti-therapeutic effects, and looks for methods to prioritize and realize the former.5 Both propose a relational, participatory criminal justice process that
departs from modern standards by providing citizens with
opportunities for empowerment and to have their needs met.6
Some have sought to identify areas of theoretical and practical convergence between the two fields regarding their implications for criminal justice reform.