Digital Commons Network^™

Short Communication: A Simple Nanoparticle - Based Tio2 Memristor Device And The Role Of Defect Chemistry In Its Operation, Rafaela De Carvalho, Tony Betts, John Cassidy

Articles

A simple metal-semiconductor-metal device comprising TiO2 cast from a suspension of Degussa P25 and placed between two metal plates (Al/Al lap shears) demonstrated memristive-like resistive switching behaviour. A mechanism is proposed which relies upon the formation of p and n-type regions within the P25 semiconductor material ultimately leading to the formation of a p-n junction. This device also exhibited enhanced steady state currents upon the imposition of potential steps, most notably at higher potential magnitudes (both anodic and cathodic), indicating lack of ionic conduction.

Preliminary Results From The Farce 2015 Campaign: Multidisciplinary Study Of The Forest–Gas–Aerosol–Cloud System On The Tropical Island Of Laréunion, Valentin Duflot, Pierre Tulet, Olivier Flores, Christelle Barthe, Aurélie Colomb, Laurent Deguillaume, Mickael Vaïtilingom, Anne Perring, Alex Huffman, Markt. Hernandez, Karine Sellegri, Ellis Robinson, David J. O'Connor, Odessa M .Gomez, Frédéric Burnet, Thierry Bourrianne, Dominique Strasberg, Manon Rocco, Allan K Bertram, Patrick Chazette, Julien Totems, Pierre Stamenoff, Jean-Marc Metzger, Mathilde Chabasset, Clothilde Rousseau, Eric Bourrianne, Martine Sancelme, Anne-Marie Delort, Rachel E. Wegener, Cedric Chou, Pablo Elizondo

Articles

The Forests gAses aeRosols Clouds Exploratory (FARCE) campaign was conducted in March–April 2015 on the tropical island of La Réunion. For the first time, several scientific teams from different disciplines collaborated to provide reference measurements and characterization of LaRéunionvegetation,volatileorganiccompounds(VOCs), biogenic VOCs (BVOCs), (bio)aerosols and composition of clouds, with a strong focus on the Maïdo mountain slope area. The main observations obtained during this 2-month intensivefieldcampaignaresummarized.Theyincludecharacterizations of forest structure, concentrations of VOCs and precursors emitted by forests, aerosol loading and optical properties in the planetary boundary layer (PBL), formation of new particles by nucleation of gas-phase precursors, icenucleatingparticlesconcentrations,andbiologicalloadingin bothcloud-freeandcloudyconditions.SimulationsandmeasurementsconfirmthattheMaïdoObservatorylieswithinthe PBL from …

Magnetic Field Sensor Based On A Tri-Microfiber Coupler Ring In Magnetic Fluid And A Fiber Bragg Grating, Fangfang Wei, Dejun Liu, Arun Kumar Mallik, Gerald Farrell, Qiang Wu, Gang-Ding Peng, Yuliya Semenova

Articles

In this paper we propose and investigate a novel magnetic field sensor based on a Tri-microfiber coupler combined with magnetic fluid and a fiber Bragg grating (FBG) in a ring. A sensitivity of 1306 pm/mT was experimentally demonstrated in the range of magnetic fields from 0 to 15 mT. The reflection peak in the output spectrum associated with the FBG serves as a reference point allowing to avoid ambiguity in determining the spectral shift induced by the magnetic field. Due to its high sensitivity at low magnetic fields, the proposed structure could be of high interest in low field biosensing …

Contracts Mattered As Much As Copyrights, Robert W. Gomulkiewicz

Articles

Scholars have begun to appreciate the fundamental role that contracts played in the development of copyrights. Contracts gave copyrights vitalilty. This article explores the network of book publishing contracts that formed the legal infrastructure for a pre-modern “internet” at the dawn of copyright law in Great Britain in the eighteenth century. Drawing on insights from archival research, the article shows how this network of copyright contracts advanced an important goal of copyright: the spread of ideas and information throughout all parts of society. Appreciating the historical significance of copyright contracts provides valuable context for modern debates about copyright policy. Indeed, …

Professionally Responsible Artificial Intelligence, Michael Hatfield

Articles

As artificial intelligence (AI) developers produce more applications for professional use, how will we determine when the use is professionally responsible? One way to answer the question is to determine whether the AI augments the professional’s intelligence or whether it is used as a substitute for it. To augment the professional’s intelligence would be to make it greater, that is, to increase and improve the professional’s expertise. But a professional who substitutes artificial intelligence for his or her own puts both the professional role and the client at risk. The problem is developing guidance that encourages professionals to use AI …

Analysis Of Bodily Fluids Using Vibrational Spectroscopy: A Direct Comparison Of Raman Scattering And Infrared Absorption Techniques For The Case Of Glucose In Blood Serum, Drishya Prachalil, Clément Bruno, Franck Bonnier, Helen Blasco, Igor Chourpa, Matthew Baker, Jennifer Mcintyre, Hugh Byrne

Articles

Analysis of biomarkers present in the blood stream can potentially deliver crucial information on patient health and indicate the presence of numerous pathologies. The potential of vibrational spectroscopic analysis of human serum for diagnostic purposes has been widely investigated and, in recent times, infrared absorption spectroscopy, coupled with ultra-filtration and multivariate analysis techniques, has attracted increasing attention, both clinical and commercial. However, such methods commonly employ a drying step, which may hinder the clinical work flow and thus hamper their clinical deployment. As an alternative, this study explores the use of Raman spectroscopy, similarly coupled with ultra-filtration and multivariate analysis …

Numerically Modelling Time And Dose Dependent Cytotoxicity, Hugh Byrne, Marcus A. Maher

Articles

Dose-response curves are fundamental tools of in vitro toxicology, extensively employed in toxicant or drug screening. They are expressed by a variety of end-points and assays, measured at different time-points in a choice of cell-lines, but are typically quantified only using the mean concentration for 50% response (e.g. drug efficacy or pathway inhibition) as an indicator of overall effect. However, the response is the result of a complex and dynamic cascade of events which occur between the initial exposure and the measured end-point, and the characteristic rates of the contributing stages govern the dose response and ultimately the measured characteristic …

Rapid Analysis Of Magnesium In Infant Formula Powder Using Laser-Induced Breakdown Spectroscopy, Maria Markiewicz-Keszycka, Ming Zhao, Xavier Cama-Moncunill, Toufic El Arnaout, Dana Becker, Colm O'Donnell, P. J. Cullen, Carl Sullivan, Maria Piedad Casado-Gavalda

Articles

Laser-induced breakdown spectroscopy (LIBS) was investigated to determine magnesium (Mg) content in infant formula powder. To predict Mg content in the range established by the Codex Alimentarius, a partial least squares regression (PLSR) model was developed using a calibration data set (n = 30) based on full cross-validation and validated using an independent validation data set (n = 21). The prediction model performance was evaluated using the regression coefficients of determination (Rcv2 = 0.94 and Rp2 = 0.85) with the root mean square errors on cross-validation and prediction (RMSECV = 60 mg kg−1 and RMSEP = 80 mg kg−1). The …

Thermostable Phytase In Feed And Fuel Industries, Ushasree Mrudula Vasudevan, Amit Jaiswal, Shyam Krishna, Ashok Pandey

Articles

Phytase with wide ranging biochemical properties has long been utilized in a multitude of industries, even so, thermostability plays a crucial factor in choosing the right phytase in a few of the sectors. Mesophilic phytases are not considered to be a viable option in the feed industry owing to its limited stability in the required feed processing temperature. In the recent past, inclusion of thermostable phytase in fuel ethanol production from starch based raw material has been demonstrated with economic benefits. Therefore, considerable emphasis has been placed on using complementary approaches such as mining of extremophilic microbial wealth, encapsulation and …

Adaptive Heuristics That (Could) Fit: Information Search And Communication Patterns In An Online Forum Of Investors Under Market Uncertainty, Niccolo Casnici, Marco Castellani, Flaminio Squazzoni, Manuela Testa, Pierpaolo Dondio

Articles

This article examines information-search heuristics and communication patterns in an online forum of investors during a period of market uncertainty. Global connections, real-time communication, and technological sophistication have created an unpredictable market environment. As such, investors try to deal with semantic, strategic, and operational uncertainty by following heuristics that reduce information redundancy. In this study, we have tried to find traces of cognitive communication heuristics in a large-scale data set including 8 years of online posts (2004–2012) for a forum of Italian investors. We identified various market volatility conditions on a daily basis to understand the influence of market uncertainty …

The Effect Of Using A Project-Based Learning (Pbl) Approach To Improve Engineering Students' Understanding Of Statistics, Fionnuala Farrell, Michael Carr

Articles

Over the last number of years we have gradually been introducing a project based learning approach to the teaching of engineering mathematics inDublin Institute of Technology. Several projects are now in existence for the teaching of both second-order differential equations and first order differential equations.We intend to incrementally extend this approach acrossmore of the engineering mathematics curriculum. As part of this ongoing process, practical realworld projects in statistics were incorporated into a second year ordinary degree mathematics module. This paper provides an overview of these projects and their implementation. As a means to measure the success of this initiative, we …

Improving Extraction Processes Of Crustacean Chitin Using Solid State Analytical Techniques, Fionn O'Fearghail, Michelle Giltrap, Christine O'Connor, Patrice Behan

Articles

Solid state analytical techniques are becoming more widely used for the analysis of a range of organic products which demonstrate very poor solubility in both common organic and polar solvents and as such cannot be accurately characterised using solution based techniques. Primarily used as a secondary technique for qualitative analysis of insoluble intermediates and products in organic synthesis, 13C CP-MAS NMR can be utilised in tandem with a targeted extraction and clean up procedure for accurate quantitative analysis of insoluble bio-molecules of interest. Here solid state 13C CP-MAS NMR is utilised as the primary analytical technique in the characterisation of …

Investigation Of Coastal Sea-Fog Formation Using The Wibs (Wide Band Integrated Bioaerosol Sensor) Technique, Shane M. Daly, David O'Connor, David A. Healy, Stig Hellebust, Jovanna Arndt, Eoinj. Mcgillicuddy, Patrick Feeney, Michael Quirke, John C. Wenger, John R. Sodeau

Articles

Abstract. A wideband integrated bioaerosol sensor (WIBS4) was deployed in Haulbowline Island, Cork Harbour, to detect fluorescence particles in real time during July and September 2011. A scanning mobility particle sizer (SMPS) was also installed providing sizing analysis of the particles over the 10–450nm range. During the campaign, multiple fog formation events occurred; they coincided with dramatic increases in the recorded fluorescent particle counts. The WIBS sizing and fluorescence intensity profiles indicated that the origin of the signals was potentially non-biological in nature (i.e. PBAPs, primary biological aerosol particles). Furthermore, the data did not support the presence of known fluorescing …

Synchrotron Macro Atr-Ftir Microspectroscopy For High Resolution Chemical Mapping Of Single Cells, Jitraporn Vongsvivut, David Perezguaita, Bayden Wood, Phil Heraud, Karina Khambatta, David Hartnell, Mark J. Hackett, Mark J. Tobin

Articles

Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy has been used widely for probing the molecular properties of materials. Coupling a synchrotron infrared (IR) beam to an ATR element using a high numerical aperture (NA) microscope objective enhances the spatial resolution, relative to transmission or transflectance microspectroscopy, by a factor proportional to the refractive index (n) of the ATR element. This work presents the development of the synchrotron macro ATR-FTIR microspectroscopy at Australian Synchrotron Infrared Microspectroscopy (IRM) Beamline, and demonstrates that high quality FTIR chemical maps of single cells and tissues can be achieved at an enhanced spatial …

Investigation Of The Assessment Of Low Degree (<50%) Renal Artery Stenosis Based On Velocity Flow Profile Analysis Using Doppler Ultrasound: An In-Vitro Study, Andrew Malone, Deepa Chari, Sean Cournane, Izabela Naydenova, Andrew J. Fagan, Jacinta Browne

Articles

Purpose: Renal arterial stenosis can lead to disrupted renal function due to reduced blood flow to the kidneys and is largely thought to be caused by atherosclerosis. Current diagnostic strategies for renal arterial stenosis rely on detecting large degree stenoses (>50%). This study aimed to test the viability of using Doppler ultrasound to assess velocity profiles to detect the presence of low degree (< 50%) stenoses.

Methods: A series of anatomically realistic renal artery flow phantoms were constructed exhibiting a range of low degree stenoses (symmetric and asymmetric). The behaviour of fluid flow in the phantoms was examined using Doppler ultrasound …

Sns Optical Fiber Structure Sensor For Direct Detection Of The Phase Transition In C18h38 N-Alkane Material, Wei Han, Marek Rebow, Xiaokang Lian, Dejun Liu, Gerald Farrell, Qiang Wu, Yuliya Semenova

Articles

A singlemode-no-core-singlemode (SNS) fiber structure optical sensor for detecting the solid-liquid phase change in a phase change material: C18H38 n-alkane material (n-octadecane) is proposed and demonstrated. The transmission-type sensor probe consists of a short section of no-core fiber sandwiched between two sections of a singlemode fiber. Phase changes in n-octadecane are accompanied by large step-like variations of its refractive index (RI). Such a large discontinuous change of the n-octadecane’s RI during its phase transition, leads to the corresponding step-like change in the transmitted optical power that can reliably indicate the phase change of the sample in the vicinity of the …

Econophysics And Fractional Calculus: Einstein's Evolution Equation, The Fractal Market Hypothesis, Trend Analysis And Future Price Prediction, Jonathan Blackledge, Derek Kearney, Marc Lamphiere, Raja Rani, Paddy Walsh

Articles

This paper examines a range of results that can be derived from Einstein’s evolution equation focusing on the effect of introducing a Lévy distribution into the evolution equation. In this context, we examine the derivation (derived exclusively from the evolution equation) of the classical and fractional diffusion equations, the classical and generalised Kolmogorov–Feller equations, the evolution of self-affine stochastic fields through the fractional diffusion equation, the fractional Poisson equation (for the time independent case), and, a derivation of the Lyapunov exponent and volatility. In this way, we provide a collection of results (which includes the derivation of certain fractional partial …

The Study Of Grit In Engineering Education Research: A Systematic Literature Review, Shannon Chance, Inês Direito, Manish Malik

Articles

Researchontheroleofgrit–definedasbothperseveranceandpassionfor long-termgoals–onhumanperformancehasbeenconductedforthepast decade. It has been suggested that this non-cognitive factor is a better predictor of students’ retention than traditional academic measures. These findings hold relevance for engineering education research but studies on this area are still scarce. This paper provides a systematic review of the current state of research on grit and its correlates in engineering higher education research. Publications were identified using three types of databases specific to engineering education; a final set of 31 relevant records was analysed by type of population, methods, research topics and main results. Most of the reviewed studies implemented quantitative methodologies to …

Use Of Matrix-Pencil Method For Efficient Islanding Detection In Static Dg And A Parallel Comparison With Dwt Method, Sanjay Agrawal, Sandipan Patra, Soumya R. Mohanty, Vineeta Agarwal, Malabika Basu

Articles

Islanding or nonislanding events in grid-connected distributed generation bring along a typical distinguishable transient signature in its frequency profile. This demarcation leads to the development of a new islanding protection approach, which is based on the estimation of frequency waveform parameter (transient's frequency) by Matrix pencil (MP) method. To demonstrate the efficacy of the proposed MP method, four critical scenarios are considered in this paper for covering all possible disturbance events. These events are also compared along with a discrete wavelet transform (DWT) based islanding detection method in simulations as well as in RT-LAB-based real-time environment. It is noteworthy to …

Associations Between Maternal Physical Activity In Early And Late Pregnancy And Offspring Birth Size: Remote Federated Individual Level Meta‐Analysis From Eight Cohort Studies, S. Pastorino, T. Bishop, S. Crozier, C. Granstrom, K. Kordas, L. Kupers, E. O'Brien, K. Polanska, K. Sauder, M. Zafarmand, R. Wilson, C. Agyemang, P. Burton, C. Cooper, E. Corpeleijn, D. Dabelea, W. Hanke, H. Inskip, F. Mcauliffe, S. Olsen, T. Vrijkotte, S. Brage, A. Kennedy, D. O'Gorman, P. Scherer, K. Wijndaele, N. Wareham, G. Desoye, K. K. Ong

Articles

Objective

Evidence on the impact of leisure time physical activity (LTPA) in pregnancy on birth size is inconsistent. We aimed to examine the association between LTPA during early and late pregnancy and newborn anthropometric outcomes.

Design

Individual level meta‐analysis, which reduces heterogeneity across studies.

Setting

A consortium of eight population‐based studies (seven European and one US) comprising 72 694 participants.

Methods

Generalised linear models with consistent inclusion of confounders (gestational age, sex, parity, maternal age, education, ethnicity, BMI, smoking, and alcohol intake) were used to test associations between self‐reported LTPA at either early (8–18 weeks gestation) or late pregnancy (30+ …

Modified Surface Relief Layer Created By Holographic Lithography: Application To Selective Sodium And Potassium Sensing, Sabad-E Gul, Luke O'Neill, John Cassidy, Izabela Naydenova

Articles

Point-of-care diagnostics will rely upon the development of low-cost, noncomplex, and easily integrated systems in order to examine biological samples such as blood and urine obtained from the patient. The development of metal ion sensors is a subject of significant relevance for physiological samples. The level of different blood electrolytes, mainly H+, Na+, K+ and Cl− is considerably used to monitor irregular physiologies. The particular challenge in biosensing, and in fact for any other sensor, is signal differentiation between non-specifically bound material and the specific detecting of the target molecule/ion. The biosensors described in this paper are fabricated by a …

Molecular Memory With Downstream Logic Processing Exemplified By Switchable And Self-Indicating Guest Capture And Release, Brian Daly, Thomas S. Moody, Allen J.M. Huxely, Chaoyi Yao, Benjamin Schazmann, Andre Alves-Areias, John F. Malone, H.Q. Nimal Gunaratne, Peter Nockemann, A. Prasanna De Silva

Articles

Molecular-logic based computation (MLBC) has grown by accumulating many examples of combinational logic gates and a few sequential variants. In spite of many inspirations being available in biology, there are virtually no examples of MLBC in chemistry where sequential and combinational operations are integrated. Here we report a simple alcohol-ketone redox interconversion which switches a macrocycle between a large or small cavity, with erect aromatic walls which create a deep hydrophobic space or with collapsed walls respectively. Small aromatic guests can be captured or released in an all or none manner upon chemical command. During capture, the fluorescence of the …

Highly Selective Fluorimetric Turn-Off Detection Of Copper (Ii) By Two Different Mechanisms In Calix[4]Arene-Based Chemosensors And Chemodosimeters, Justine O'Sullivan, John Colleran, Brendan Twamley, Frances Heaney

Articles

Isoxazolo‐pyrene tethered calix[4]arenes selectively detect copper(II) ions without interference from related perchlorate ions. The fluorescence emission of the probes, synthesised by nitrile oxide alkyne cycloaddition, and characterised by spectroscopic and crystallographic data, is rapidly reduced by Cu(II) ions. Detection limits are in the micromolar or sub‐micromolar range (0.3–3.6 μM) based on a 1 : 1 sensor:analyte interaction. Voltammetric behaviour and 1H NMR data provide new insights into the sensing mechanism which is dependent on the calixarene substitution pattern. When the calixarene lower rim is fully substituted, Cu(II) detection occurs through a traditional chelation mechanism. In contrast, for calixarenes 1,3‐disubstituted on …

Nanomole Silver Detection In Chloride-Free Phosphate Buffer Using Platinum And Gold Micro- And Nanoelectrodes, Prabhakar Sidambaram, John Colleran

Articles

The electrochemical determination of ultra-low concentrations of silver requires reliable, reproducible measurements using sensitive analytical techniques. To date, the electrochemical determination of silver in biological buffers and pH neutral media has not been successful in terms of reproducibility. In this work, we report on the determination of ultra-low concentrations of silver in chloride-free phosphate buffer solution (PB, pH 7.4). Detection was conducted at gold and platinum micro and nanoelectrodes using anodic stripping voltammetry (ASV). The micro and nanoelectrodes were fabricated using a Sutter P-2000 laser puller, with physical and electrochemical characterization revealing flat disk-shaped working surfaces of 10–15 μm (microelectrode) …

Low-Resolution Models For The Interaction Dynamics Of Coated Gold Nanoparticles With Β2-Microglobulin, Giorgia Brancolini, Hender Lopez, Stefano Corni, Valentina Tozzini

Articles

A large number of low-resolution models have been proposed in the last decades to reduce the computational cost of molecular dynamics simulations for bio-nano systems, such as those involving the interactions of proteins with functionalized nanoparticles (NPs). For the proteins, “minimalist” models at the one-bead-per residue (Cα-based) level and with implicit solvent are well established. For the gold NPs, widely explored for biotechnological applications, mesoscale (MS) models treating the NP core with a single spheroidal object are commonly proposed. In this representation, the surface details (coating, roughness, etc.) are lost. These, however, and the specificity of the functionalization, have been …

Impact Of Plasma Treatment On Acoustic Properties Of Natural Cellulose Materials, Sanja S. Pavlović, Snežana B. Stanković, Andrijana Žekić, Miloš Nenadović, Dušan M. Popović, Vladimir Milosavljevic, Goran B. Poparić

Articles

Low-temperature plasma is widely used in many surface treatment technologies for modifications of the physical properties of different polymeric materials. In the present work, we have examined the modification of acoustical properties of natural cellulose materials (cotton, hemp) by the radio-frequency argon plasma. We have observed an increase of the sound absorption coefficient due to the plasma treatment for certain range of applied powers. An analysis of elementary processes which happened during plasma–material interaction was conducted. Additional analyses related to material characterizations were performed in order to resolve structural and chemical changes of plasma treated materials. The micro-mechanical modification of …

Concentric Double Hollow Grid Cathode Discharges, C. T. Teodorescu-Soare, S. A. Irimiciuc, C. Ionita, D. G. Dimitriu, B. Hodoroaba, T. O'Hara, O. Vasilovici, L. Amarandi, R. W. Schrittwieser

Articles

A new cathode system, consisting of two concentric spherical hollow grids with two aligned orifices, is investigated by space-resolved Langmuir probe measurements and non-linear dynamics analysis. Negative biases of this spherical hollow grids arrangement lead to the formation of two complex space charge structures in the regions of the orifices. The overall dynamics of the current-voltage characteristic (I–V characteristic) of each discharge is characterized by strong oscillatory behaviour with various waveforms correlated with jumps in the static I–V characteristics. Space-resolved measurements through the two aligned orifices of the two grids show a peak increase of the electron temperature and particle …

Predicting Quality Attributes And Waste Of Strawberry Packed Under Modified Atmosphere Throughout The Cold Chain, Kompal Johsi, Brijesh Tiwari, Patrick J. Cullen, Jesus Maria Frias

Articles

Modified Atmosphere Packaging (MAP) is used commercially to extend the shelf life of strawberries. The attainment of desired gas (O2, CO2) concentrations inside MAP relies on the product respiration and the mass transfer through packaging and will affect the quality. The objective of this work is to build a mathematical model for strawberries to assess the effect of the uncertainties on headspace gas concentration and quality: 1) cold chain related temperature and relative humidity variations and 2) variability associated to product respiration and quality based on literature. Weight loss was more influenced by the cold chain storage conditions (temperature and …

Nuclear Frames In The Irish Media: Implications For Conversations On Nuclear Power Generation In The Age Of Climate Change, Catherine Devitt, Finbarr Brereton, Simon Mooney, David Conway, Eoin O'Neill

Articles

Keeping within the temperature limits set by the Paris Agreement on climate action will be a significant challenge. Nuclear power generation may contribute to achieving these targets, however, there are significant environmental, economic and health risks attached. Using qualitative and quantitative methods, this paper explores how nuclear power generation is framed in the Irish print media, and discusses the implications of these frames for how nuclear power is perceived within the context of climate change mitigation in Ireland. Two Irish broadsheet papers, the Irish Times and the Irish Independent were selected for data collection, focusing on Chernobyl and Fukushima incidents. …

Luminescent Calcium Carbonate Micro ‘Bow Ties’, Fearghal C. Donnelly, Finn Purcell-Milton, Peter W. Dunne, Aleksandra Rulikowska, Victor Alguacil, Yurii K. Gun’Ko

Articles

Calcium carbonate (CaCO3) is a ubiquitous material which has been studied for centuries due to its integral nature across various fields and its vast range of applications. Here we report, for the first time, a low temperature dry ice carbonation method for the production of unique rare earth-doped calcium carbonate ‘bow ties’. CaCO3 exhibits retrograde solubility, an interesting property in which its solubility increases with decreasing temperature. In this synthesis, dry ice acts not only as a CO2 source, but as a coolant, increasing the solubility of CaCO3 and CO2 and allowing specific growth to occur. The incorporation of trivalent …