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1,3-Dipolar cycloadditions of 2-thio-3-chloroacrylamides with diazoalkanes
(RSC Publishing, 2010-06-21) Kissane, Marie; Lawrence, Simon E.; Maguire, Anita R.; Irish Research Council for Science Engineering and Technology
2-Thio-3-chloroacrylamides undergo 1,3-dipolar cycloadditions with diazoalkanes leading to a series of novel pyrazolines and pyrazoles. The mechanistic and synthetic features of the cycloadditions to the 2-thio-3-chloroacrylamides at both the sulfide and sulfoxide levels of oxidation are rationalised on the basis of the nature of the substituents.
1,3-Dipolar cycloadditions of 2-thio-3-chloroacrylamides with nitrile oxides and nitrones
(Elsevier, 2010-06-19) Kissane, Marie; Lawrence, Simon E.; Maguire, Anita R.; Irish Research Council for Science Engineering and Technology
1,3-Dipolar cycloadditions of 2-thio-3-chloroacrylamides with nitrile oxides and nitrones is described. A series of novel isoxazolines are isolated from the nitrile oxide cycloadditions, whilst the isoxazolines generated from the nitrone cycloadditions undergo further ring opening to yield piperidines.
1-to- N ring power combiners with common delta ports
(Institute of Electrical and Electronics Engineers (IEEE), 2019-01-04) Holzer, Kyle D.; Walling, Jeffrey S.; National Science Foundation
In this paper, we present a new 1-to-N way ring combiner that is an adaptation of the ring-hybrid (rat-race) structure. We present the general design guidelines for N-way planar ring combiners based on theoretical analysis of the structures. The proposed 1-to-N way ring structure offers a compact, planar layout that includes a single common delta port. This is beneficial to applications where power monitoring, calibration, or energy recycling can be leveraged. It offers similar loss to other N-way structures. To demonstrate the combiners operation, we present completely passive structures and structures with embedded power amplifiers for 4- and 6-way variants. The designs are optimized for operation in the 5-6 GHz unlicensed bands. The passive 4- and 6-way combiners achieve IL of 1.3 and 1 dB, respectively, with associated port isolations of <;-30 dB. The combiners with embedded amplifiers show similar performance and are validated using modulated signals and demonstrate good measured linearity when combining up to 6 amplifiers for output powers >1 W.
A 100 year review of electricity policy in Ireland (1916–2015)
(Elsevier Ltd., 2017-02-21) Gaffney, Fiac; Deane, John Paul; Ó Gallachóir, Brian P.; Bord Gáis Energy
Over the past century, Ireland's electricity sector has undergone a significant transformation. This paper documents the nation's struggle to build an electricity system, to improve security of electricity supply through portfolio diversification and to promote indigenous energy sources. This was a challenge for an (electrically) isolated island with little natural resources. The paper also identifies the ineffective policy decisions that left Ireland exposed to the 1970s energy crises. The crises did, however, provide a clear impetus for focusing Irish energy policy going forward. The successful deployment and integration of large-scale wind power was due to strong national and supranational policy decisions. In 2015, Ireland had the third highest wind energy share of national electricity demand (22.8%) of all IEA Wind Member Countries. The paper also traces Ireland's transition through market reform, regional fragmentation, and looks onwards to the EU internal market for electricity. In essence, this paper provides a holistic view of the implications of various policy decisions on the electricity sector along with the stresses of external factors on the electricity market and should be useful for policy makers elsewhere faced with similar decisions.
10Gb/s low-cost directly modulated multi-electrode laser with suppressed thermal wavelength drift for burst-mode upstream transmission in TWDM-PONs
(Optical Society of America, 2018-06-14) Porto, Stefano; van Veen, Doutje; Houtsma, Vincent; Basavanhally, Nagesh; Bolle, Cris; Schmuck, Harald; Townsend, Paul D.; Earnshaw, Mark; Pfeiffer, Thomas; Science Foundation Ireland
We report on a novel 10Gb/s low-cost multi-electrode DML employed as a very wavelength stable burst-mode source for upstream TWDM-PONs. 10X wavelength drift reduction is achieved compared to conventional DMLs enabling transmission on 100GHz grid.
A 10Gbps optical burst switching network incorporating ultra-fast (5ns) wavelength switched tunable laser sources
(SPIE, 2017) Ryan, Neil; Todd, Michael; Farrell, Tom; Lavin, Adrian; Rigole, Pierre-Jean; Corbett, Brian M.; Roycroft, Brendan; Engelstaedter, Jan-Peter
This paper outlines the development of a prototype optical burst mode switching network based upon a star topology, the ultimate application of which could be as a transparent payload processor onboard satellite repeaters. The network architecture incorporates multiple tunable laser sources, burst mode receivers and a passive optical router (Arrayed Waveguide Grating). Each tunable optical signal should carry ≥10Gbps and be capable of wavelength switching in c. 5ns timescales. Two monolithic tunable laser types, based upon different technologies, will be utilised: a Slotted Fabry Perot laser (a Fabry Perot laser with slots added in order to introduce controlled cavity perturbations); and a Modulated Grating Y-Branch Laser (MGY: a widely tunable, multi-section device similar to the DBR laser). While the Slotted Fabry Perot laser is expected to achieve the required switching times, it is an immature technology not yet capable of achieving tunability over 80 ITU channels from a single chip. The MGY device is a more mature technology and has full C-band ITU channel coverage, but is not capable of the required short switching times. Hence, in order to facilitate the integration of this more mature technology into the prototype breadboard with the requisite switching time capabilities, a system of ‘dual laser’ transmitters is being developed to enable data transmission from one MGY laser while the other switches and vice-versa. This work is being performed under ESA contract AO 1-5025/06/NL/PM, Optical Technologies for Ultra - fast Processing.
128 × 128 silicon photonic MEMS switch package using glass interposer and pitch reducing fibre array
(Institute of Electrical and Electronics Engineers (IEEE), 2017-12) Hwang, How Yuan; Morrissey, Padraic E.; Lee, Jun Su; O'Brien, Peter A.; Henriksson, Johannes; Wu, Ming C.; Seok, Tae Joon; Science Foundation Ireland
We design and fabricate the packaging of 128 × 128 silicon photonic MEMS switch device using through glass via (TGV) interposer and pitch reducing fibre array. The switch device contains 16384 MEMS switch cells and 272 grating couplers spaced at 63.5 μm in a compact footprint of 17.4 mm × 16 mm. The apodised grating couplers designed for 1300 nm have an insertion loss of 2.5 dB/facet at 10° coupling angle. The 0.5 mm thick glass interposer contains 512 electrical vias while the pitch reducing optical coupling array is polished to 40° for planar coupling.
16S rRNA gene sequencing of mock microbial populations-impact of DNA extraction method, primer choice and sequencing platform
(BioMed Central, 2016-06-24) Fouhy, Fiona; Clooney, Adam G.; Stanton, Catherine; Claesson, Marcus J.; Cotter, Paul D.; Seventh Framework Programme; Science Foundation Ireland
Background: Next-generation sequencing platforms have revolutionised our ability to investigate the microbiota composition of complex environments, frequently through 16S rRNA gene sequencing of the bacterial component of the community. Numerous factors, including DNA extraction method, primer sequences and sequencing platform employed, can affect the accuracy of the results achieved. The aim of this study was to determine the impact of these three factors on 16S rRNA gene sequencing results, using mock communities and mock community DNA. Results: The use of different primer sequences (V4-V5, V1-V2 and V1-V2 degenerate primers) resulted in differences in the genera and species detected. The V4-V5 primers gave the most comparable results across platforms. The three Ion PGM primer sets detected more of the 20 mock community species than the equivalent MiSeq primer sets. Data generated from DNA extracted using the 2 extraction methods were very similar. Conclusions: Microbiota compositional data differed depending on the primers and sequencing platform that were used. The results demonstrate the risks in comparing data generated using different sequencing approaches and highlight the merits of choosing a standardised approach for sequencing in situations where a comparison across multiple sequencing runs is required.
(2+1)-dimensional photonic crystals from Langmuir-Blodgett colloidal multilayers
(AIP Publishing, 2006) Romanov, Sergei G.; Bardosova, Maria; Pemble, Martyn E.; Torres, C. M. Sotomayor; Science Foundation Ireland; Sixth Framework Programme
Angle-resolved transmission spectra of multilayers of two-dimensional colloidal crystals prepared by the Langmuir-Blodgett technique have been studied. In contrast to the light diffraction in three-dimensional colloidal crystals, optical spectra revealed only very weak correlation between layers in the Langmuir-Blodgett multilayers. Two reasons for the observed transmission minima have been identified: the diffraction at a stack of layers and the scattering of the incident beam by guided modes of the two-dimensional colloidal crystals. (c) 2006 American Institute of Physics. (DOI:10.1063/1.2234568)
A 2-MS/s, 11.22 ENOB, extended input range SAR ADC with improved DNL and offset calculation
(Institute of Electrical and Electronics Engineers (IEEE), 2018-11) Asghar, Sohail; Afridi, Sohaib Saadat; Pillai, Anu; Schuler, Anita; de la Rosa José; O'Connell, Ivan; Enterprise Ireland; European Regional Development Fund; Junta de Andalucía
A 12-bit successive approximation register analog-to-digital converter (ADC) with extended input range is presented. Employing an input sampling scaling technique, the presented ADC can digitize the signals with an input range of 3.2 V pp-d (±1.33 V REF ). The circuit also includes a comparator offset compensation technique that results in a residual offset of less than 0.5 LSB. The chip has been designed and implemented in a 0.13-μm CMOS process and demonstrates the state-of-the-art performance, featuring an SNDR of 69.3 dB and the SFDR of 79 dB without requiring any calibration. Total power consumption of the ADC is 0.9 mW, with a measured differential non-linearity of 1.2/-1.0 LSB and INL of 2.3/-2.2 LSB.
2000 - 2017 inventory of extreme weather events in Ireland
(2019-01-01) Pasik, Adam; Hickey, Kieran; Leahy, Paul; Environmental Protection Agency
Globally, extreme weather events are responsible for far more financial losses than the increase in mean temperature. In the context of climate change, attribution of the ever-increasing losses from these high-impact events is still contested. Some research finds climate change to drive the rising costs while other attributes this trend to socioeconomic factors such as higher population densities, demographical shift, accumulation of wealth and exposure of assets. As of yet no systematic inquiry into this matter has been carried out in Ireland. This research compiles a dataset of extreme weather events in Ireland between 2000 and 2017 based on an applied financial threshold of €30m. The overall annual losses are adjusted for inflation and emerging trends are identified and discussed. Population change and per capita GDP are considered as important variables in this research due to their potential to exacerbate losses even without any change in their frequency or climate. Temporal trends in population and per capita GDP are discussed as well as emerging spatial patterns in population distribution. Furthermore, loss values are normalized by adjusting them for inflation, population rise and GDP growth to better understand the relationship between losses from weather extremes and societal and economic factors. The results are contextualized in relevant peer-reviewed literature and compared to similar studies carried out elsewhere in the world. This study, in agreement with similar research implemented elsewhere, establishes an increasing trend in annual losses from weather extremes in Ireland, while also demonstrating that this trend is nullified by population rise and economic growth. During the study period population of Ireland has increased by 26.4%, resulting in 1 million new residents, meanwhile, the per capita GDP has more than doubled. Larger and wealthier populations hold more assets which can be potentially damaged. Losses from weather extremes in Ireland adjusted for population and wealth increase no longer show a rising trend, highlighting the importance of population densities and wealth accumulation as key factors driving the increase in financial damages stemming from weather and climatic extremes.
25Gb/s PAM4 adaptive receiver equalisation requirements for burst-mode transmission systems
(VDE Verlag GMBH, 2016-12-05) Dalla Santa, Marco; Antony, Cleitus; Talli, Giuseppe; Townsend, Paul D.; Science Foundation Ireland
Requirements for burst-mode equalisation in a 25Gb/s PAM4 system for passive optical network upstream traffic are analysed for different linear equaliser solutions, with transmission over 40km of fibre. The impact of chromatic dispersion, transmitter bandwidth restriction and non-linearities is considered.
25Gb/s PAM4 burst-mode system for upstream transmission in passive optical networks
(Institute of Electrical and Electronics Engineers (IEEE), 2017-06-01) Dalla Santa, Marco; Antony, Cleitus; Power, Mark; Jain, Anil; Ossieur, Peter; Talli, Giuseppe; Townsend, Paul D.; Science Foundation Ireland
A 25Gb/s PAM4 burst-mode upstream transmission is demonstrated over 25km of fiber using 10G components and a linear burst-mode TIA with a 14.7dB dynamic range and with differential chromatic dispersion equivalent to 25km of fiber.
2D and 3D photonic crystal materials for photocatalysis and electrochemical energy storage and conversion
(National Institute for Materials Science; Taylor & Francis, 2016-09) Collins, Gillian; Armstrong, Eileen; McNulty, David; O'Hanlon, Sally; Geaney, Hugh; O'Dwyer, Colm; National University of Ireland; Science Foundation Ireland
This perspective reviews recent advances in inverse opal structures, how they have been developed, studied and applied as catalysts, catalyst support materials, as electrode materials for batteries, water splitting applications, solar-to-fuel conversion and electrochromics, and finally as photonic photocatalysts and photoelectrocatalysts. Throughout, we detail some of the salient optical characteristics that underpin recent results and form the basis for light-matter interactions that span electrochemical energy conversion systems as well as photocatalytic systems. Strategies for using 2D as well as 3D structures, ordered macroporous materials such as inverse opals are summarized and recent work on plasmonic–photonic coupling in metal nanoparticle-infiltrated wide band gap inverse opals for enhanced photoelectrochemistry are provided.
2D and 3D vanadium oxide inverse opals and hollow sphere arrays
(Royal Society of Chemistry (RSC), 2014-10-24) Armstrong, Eileen; Osiak, Michal J.; Geany, Hugh; Glynn, Colm; O'Dwyer, Colm; Irish Research Council; Science Foundation Ireland; Seventh Framework Programme
High quality 2D and 3D inverse opals and hollow sphere arrays of vanadium oxide are grown on conductive substrates from colloidal polymer sphere templates formed by electrophoretic deposition or surfactant-assisted dip-coating. Inverse opals (IOs) are formed using variants of solution drop-casting, N2-gun assisted infiltration and high-rate (200 mm min−1) iterative dip-coating methods. Through Raman scattering, transmission electron microscopy and optical diffraction, we show how the oxide phase, crystallinity and structure are inter-related and controlled. Opal template removal steps are demonstrated to determine the morphology, crystallinity and phase of the resulting 2D and 3D IO structures. The ability to form high quality 2D IOs is also demonstrated using UV Ozone removal of PMMA spheres. Rapid hydrolysis of the alkoxide precursor allows the formation of 2D arrays of crystalline hollow spheres of V2O5 by utilizing over-filling during iterative dip-coating. The methods and crystallinity control allow 2D and 3D hierarchically structured templates and inverse opal vanadium oxides directly on conductive surfaces. This can be extended to a wide range of other functional porous materials for energy storage and batteries, electrocatalysis, sensing, solar cell materials and diffractive optical coatings.
2D nanosheet paint from solvent-exfoliated Bi2Te3 ink
(American Chemical Society, 2017-08-09) Carroll, Elaine; Buckley, Darragh; Mogili, N. V. V.; McNulty, David; Moreno, M. Sergio; Glynn, Colm; Collins, Gillian; Holmes, Justin D.; Razeeb, Kafil M.; O'Dwyer, Colm; Irish Research Council; Science Foundation Ireland; Consejo Nacional de Investigaciones Científicas y Técnicas; Agencia Nacional de Promoción Científica y Tecnológica; Horizon 2020; Analog Devices; Ministry of Science, Technology, Innovation and Communication, Brazil
Embedding 2D layered materials into polymers and other materials as composites has resulted in the development of ultrasensitive pressure sensors, tunable conductive stretchable polymers, and thermoelectric coatings. As a wettable paint or ink, many 2D materials may be penciled, printed, or coated onto a range of surfaces for a variety of applications. However, the intrinsic conductive properties of painted coatings using 2D and layered materials are not completely understood, and conductive polymer additives may mask underlying properties such as directional conductivity. We report a process for making a paint from solvent-exfoliated Bi2Te3 into solution-dispersible 2D and few-layer (multiple quintuple) nanosheet inks, that form smooth, uniform paint blends at several concentrations of Bi2Te3. The individual solvent-exfoliated nanosheets are edge-coated by (poly)ethylene glycol to produce a paint, stable over extended period in solution. Electrical transport is found to be sensitive to aspect ratio, and conduction along the painting direction is suppressed for longer strips so long as the aspect ratio is high (4–10× or more), but for short and wide paint strips (aspect ratio ≤1), conductance is improved by a factor of 3×. Square 2D paint regions show no clear directional preference for conductance at room temperature but are markedly affected by higher temperatures. Conductivity along a preferential conduction pathway through the nanosheet ensemble is modulated by 2D nanosheet stacking along the direction of paint application for a given aspect ratio. This paint and insights into geometrical 2D composite conduction may have implications for conductive composites, thermoelectrics, and writable circuits using 2D material paints or inks.
A 3D hand motion capture device with haptic feedback for virtual reality applications
(Institute of Electrical and Electronics Engineers (IEEE), 2018-11-01) Torres-Sanchez, Javier; Tedesco, Salvatore; O'Flynn, Brendan; Science Foundation Ireland; European Regional Development Fund; Enterprise Ireland
In this paper, the challenges associated with the design of new generation hand motion capture devices for Virtual Reality (VR) applications are described. The need for developing a hand motion capture device with tactile feedback that integrates all the sensors and actuators associated with VR, while meeting the latency requirements is introduced. A detailed description of functional and non-functional specifications is also given. Finally, a comparison study with commercially available technology is provided highlighting that the proposed device compares favorably not only in terms of functional parameters, such as connectivity, integration of sensors and actuators, and latency, but also in terms of non-functional parameters, e.g., no need to wash, ambidextrous features and modularity.
3D interconnection by FIB assisted Pt deposition and electroless nickel deposition on the sides and edges of an I-Seed
(Institute of Electrical and Electronics Engineers (IEEE), 2006-05) Razeeb, Kafil M.; Nagle, Lorraine C.; Barton, John; Tassie, Paul; O'Flynn, Brendan; Rohan, James F.; Ó Mathúna, S. Cian; European Commission
This paper reports on the development of a 3D interconnection process leading to the successful assembly of a five-layer 3-D 1mm cube module. This proof of concept module demonstrates the capability for successful integration and interconnection of commercial off the shelf components to fabricate functional modules in 1mm cube dimensions. It also demonstrates that use of established volume scale technologies like Flip-chip, dicing and patterning techniques are viable for fabricating these 1mm modules. The demonstrator consists of LED's bonded to the six sides of the 1mm cube, interconnected and powered up. The work will particularly report on two different processes to fabricate the interconnection pattern using direct Focused Ion Beam (FIB) assisted Pt deposition and electroless metal deposition, which again patterned by FIB. Uniform thickness of the deposit and excellent coverage on all six sides is achieved by electroless nickel deposition. Voltage current characterisation of the deposited Pt shows a resistivity value of 1864 +/- 100 mu Omega cm, whereas electroless Ni film shows a resistivity of 25 mu Omega cm due to boron inclusion. 100 nm An layer is deposited by chemical displacement reaction to enhance the conductivity and solderability of the film.
3D open-worked inverse opal TiO2 and GeO2 materials for long life, high capacity Li-ion battery anodes
(Elsevier, 2017-10-18) McNulty, David; Lonergan, Alex; O'Hanlon, Sally; O'Dwyer, Colm; Science Foundation Ireland; Irish Research Council
In this short review, we overview some advancements made in Li-ion battery anode development, where the structural arrangement of the material plays an important role. Specifically, we summarise the benefits of 3D macroporous structure imposed the anode material, in order to improve ionic and electronic conductivity in the absence of conductive additives and binders. Two anode materials are overviewed: TiO2 and GeO2. These are either high capacity anode materials or accessible, abundant materials that are capable of very stable and long-term cycling. We have focused this review on 3D inverse opal structures of these anodes and summarise their enhanced behaviour by comparing their performance metrics to a range of nanoscale and porous analogues of these materials.
A 3D printed electromagnetic nonlinear vibration energy harvester
(IOP Publishing Ltd, 2016-08-24) Constantinou, Peter; Roy, Saibal; Science Foundation Ireland
A 3D printed electromagnetic vibration energy harvester is presented. The motion of the device is in-plane with the excitation vibrations, and this is enabled through the exploitation of a leaf isosceles trapezoidal flexural pivot topology. This topology is ideally suited for systems requiring restricted out-of-plane motion and benefits from being fabricated monolithically. This is achieved by 3D printing the topology with materials having a low flexural modulus. The presented system has a nonlinear softening spring response, as a result of designed magnetic force interactions. A discussion of fatigue performance is presented and it is suggested that whilst fabricating, the raster of the suspension element is printed perpendicular to the flexural direction and that the experienced stress is as low as possible during operation, to ensure longevity. A demonstrated power of ~25 μW at 0.1 g is achieved and 2.9 mW is demonstrated at 1 g. The corresponding bandwidths reach up-to 4.5 Hz. The system's corresponding power density of ~0.48 mW cm−3 and normalised power integral density of 11.9 kg m−3 (at 1 g) are comparable to other in-plane systems found in the literature.

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