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Full-Text Articles in Physical Sciences and Mathematics

Raman Spectroscopic Analysis Of Human Serum Samples Of Convalescing Covid-19 Positive Patients, Hugh Byrne, Naomi Jackson, Jaythoon Hassan Dec 2023

Raman Spectroscopic Analysis Of Human Serum Samples Of Convalescing Covid-19 Positive Patients, Hugh Byrne, Naomi Jackson, Jaythoon Hassan

Articles

Rapid screening, detection and monitoring of viral infection is of critical importance, as exemplified by the rapid spread of SARS-CoV-2, leading to the worldwide pandemic of COVID-19. This is equally the case for the stages of patient convalescence as for the initial stages of infection, to understand the medium and long terms effects, as well as the efficacy of therapeutic interventions. Optical spectroscopic techniques potentially offer an alternative to currently employed techniques of screening for the presence, or the response to infection. In this study, the ability of Raman spectroscopy to distinguish between samples of the serum of convalescent COVID-19 …


A Primer On The Legendre Transformation, Steven J. Kilner, David L. Farnsworth Nov 2023

A Primer On The Legendre Transformation, Steven J. Kilner, David L. Farnsworth

Articles

Guidance is offered for understanding and using the Legendre transformation and its associated duality among functions and curves. The genesis of this paper was encounters with colleagues and students asking about the transformation. A main feature is simplicity of exposition, while keeping in mind the purpose or application for using the transformation.


Probability Distributions Arising In Connection With The Inspection Paradox For Bernoulli Trials., James E. Marengo, Anne Marino Himes, W. Cade Reinberger, David L. Farnsworth Nov 2023

Probability Distributions Arising In Connection With The Inspection Paradox For Bernoulli Trials., James E. Marengo, Anne Marino Himes, W. Cade Reinberger, David L. Farnsworth

Articles

In renewal theory, the Inspection Paradox refers to the fact that an interarrival period in a renewal process which contains a fixed inspection time tends to be longer than one for the corresponding uninspected process. We focus on the paradox for Bernoulli trials. Probability distributions and moments for the lengths of the interarrival periods are derived for the inspected process, and we compare them to those for the uninspected case.


Partnering For Climate Resilience: Exploring The Maturity Of Private-Sector Efforts In The Great Lakes Region, Lisa Greenwood, Yewande Abraham, Jennifer Schneider, Vicki Lin Sep 2023

Partnering For Climate Resilience: Exploring The Maturity Of Private-Sector Efforts In The Great Lakes Region, Lisa Greenwood, Yewande Abraham, Jennifer Schneider, Vicki Lin

Articles

Communities and businesses continue to experience the effects of climate change as global temperatures rise and extreme weather events become more frequent. In the United States (US), the public sector has traditionally been responsible for mitigating these risks; however, engaging the private sector is crucial, given industrial impacts on and vulnerability to climate change. Private-sector mitigation and adaptation efforts are critical in the Great Lakes Region due to aging infrastructure as well as its economic, environmental, and political importance in the US and Canada. This study explores private-sector resilience efforts in three Great Lakes cities to identify opportunities and trends …


Dynamic Influence Diagram-Based Deep Reinforcement Learning Framework And Application For Decision Support For Operators In Control Rooms, Joseph Mietkiewicz, Ammar N. Abbas, Chidera W. Amazu, Anders L. Madsen, Gabriele Baldissone Sep 2023

Dynamic Influence Diagram-Based Deep Reinforcement Learning Framework And Application For Decision Support For Operators In Control Rooms, Joseph Mietkiewicz, Ammar N. Abbas, Chidera W. Amazu, Anders L. Madsen, Gabriele Baldissone

Articles

In today’s complex industrial environment, operators are often faced with challenging situations that require quick and accurate decision-making. The human-machine interface (HMI) can display too much information, leading to information overload and potentially compromising the operator’s ability to respond effectively. To address this challenge, decision support models are needed to assist operators in identifying and responding to potential safety incidents. In this paper, we present an experiment to evaluate the effectiveness of a recommendation system in addressing the challenge of information overload. The case study focuses on a formaldehyde production simulator and examines the performance of an improved Human-Machine Interface …


A Method For Generating A Non-Manual Feature Model For Sign Language Processing, Robert G. Smith Dr, Markus Hofmann Dr Aug 2023

A Method For Generating A Non-Manual Feature Model For Sign Language Processing, Robert G. Smith Dr, Markus Hofmann Dr

Articles

While recent approaches to sign language processing have shifted to the domain of Machine Learning (ML), the treatment of Non-Manual Features (NMFs) remains an open question. The principal challenge facing this method is the comparatively small sign language corpora available for training machine learning models. This study produces a statistical model which may be used in future ML, rules-based, and hybrid-learning approaches for sign language processing tasks. In doing so, this research explores the emerging patterns of non-manual articulation concerning grammatical classes in Irish Sign Language (ISL). The experimental method applied here is a novel implementation of an association rules …


Optical Characterisation Of Holographic Diffusers And Bangerter Foils For Treatment Of Amblyopia, Matthew Hellis, Suzanne Martin, Matthew Sheehan, Kevin Murphy Jun 2023

Optical Characterisation Of Holographic Diffusers And Bangerter Foils For Treatment Of Amblyopia, Matthew Hellis, Suzanne Martin, Matthew Sheehan, Kevin Murphy

Articles

Amblyopia is a significant issue for children worldwide, and current treatment methods have drawbacks that can hinder treatment effectiveness and/or patient experience. This study proposes a new treatment method using holographic diffusers while also comparing their optical characteristics to a current treatment method (Bangerter foils). Holographic diffusers were developed by optically patterning thin polymer layers on a micron scale. Two compositions of photopolymer (acrylamide and diacetone acrylamide based) are analysed herein. Characterisation shows that holographic diffusers of either composition can achieve a wide range of on-axis intensity reductions, allowing for precise and customisable treatment levels by altering recording exposure time …


The State Of Accessibility In Blackboard: Survey And User Reviews Case Study, Mohamed Wiem Mkaouer, Wajdi Aljedaani, Stephanie Ludi, Mohammed Alkahtani, Marcelo M. Eler, Marouane Kessentini, Ali Ouni Apr 2023

The State Of Accessibility In Blackboard: Survey And User Reviews Case Study, Mohamed Wiem Mkaouer, Wajdi Aljedaani, Stephanie Ludi, Mohammed Alkahtani, Marcelo M. Eler, Marouane Kessentini, Ali Ouni

Articles

Context: Nowadays, mobile applications (or apps) have become vital in our daily life, particularly within education. Many institutions increasingly rely on mobile apps to provide access to all their students. However, many education mobile apps remain inaccessible to users with disabilities who need to utilize accessibility features like talkback or screen reader features. Accessibility features have to be considered in mobile apps to foster equity and inclusion in the educational environment allowing to use of such apps without limitations. Gaps in the accessibility to educational systems persist.

Objective: In this paper, we focus on the accessibility of the Blackboard mobile …


Analog Holographic Wavefront Sensor For Defocus And Spherical Aberration Measurement Recorded In A Photopolymer, Emma Branigan, Suzanne Martin, Matthew Sheehan, Kevin Murphy Feb 2023

Analog Holographic Wavefront Sensor For Defocus And Spherical Aberration Measurement Recorded In A Photopolymer, Emma Branigan, Suzanne Martin, Matthew Sheehan, Kevin Murphy

Articles

An analog holographic wavefront sensor (AHWFS), for measurement of low and high order (defocus and spherical aberration) aberration modes has been developed as volume phase holograms in a photopolymer recording medium. This is the first time that high order aberrations such as spherical aberration can be sensed using a volume hologram in a photosensitive medium. Both defocus and spherical aberration were recorded in a multi-mode version of this AHWFS. Refractive elements were used to generate a maximum and minimum phase delay of each aberration which were multiplexed as a set of volume phase holograms in an acrylamide based-photopolymer layer. The …


Fair4pghd: A Framework For Fair Implementation Over Pghd, Abdullahi Abubakar Kawu, Dympna O'Sullivan, Lucy Hederman, Mirjam Van Reisen Feb 2023

Fair4pghd: A Framework For Fair Implementation Over Pghd, Abdullahi Abubakar Kawu, Dympna O'Sullivan, Lucy Hederman, Mirjam Van Reisen

Articles

Patient Generated Health Data (PGHD) are being considered for integration with health facilities, however little is known about how such data can be made machine-actionable in a way that meets FAIR guidelines. This article proposes a 5-stage framework that can be used to achieve this.


Modeling And Fitting Two-Way Tables Containing Outliers, David L. Farnsworth Feb 2023

Modeling And Fitting Two-Way Tables Containing Outliers, David L. Farnsworth

Articles

A model is proposed for two-way tables of measurement data containing outliers. The two independent variables are categorical and error free. Neither missing values nor replication are present. The model consists of the sum of a customary additive part that can be fit using least squares and a part that is composed of outliers. Recommendations are made for methods for identifying cells containing outliers and for fitting the model. A graph of the observations is used to determine the outliers’ locations. For all cells containing an outlier, replacement values are determined simultaneously using a classical missing-data tool. The result is …


Determining The Proportionality Of Ischemic Stroke Risk Factors To Age, Elizabeth Hunter, John D. Kelleher Jan 2023

Determining The Proportionality Of Ischemic Stroke Risk Factors To Age, Elizabeth Hunter, John D. Kelleher

Articles

While age is an important risk factor, there are some disadvantages to including it in a stroke risk model: age can dominate the risk score and lead to over-or under-predictions in some age groups. There is evidence to suggest that some of these disadvantages are due to the non-proportionality of other risk factors with age, eg, risk factors contribute differently to stroke risk based on an individual’s age. In this paper, we present a framework to test if risk factors are proportional with age. We then apply the framework to a set of risk factors using Framingham heart study data …


Electromechanical Coupling In Collagen Measured Under Increasing Relative Humidity, Arwa Bazaid, Fengyuan Zhang, Qiancheng Zhang, Sabine Neumayer, Denise Denning, Stefan Habelitz, Ana Marina Ferreira, Brian J. Rodriguez Jan 2023

Electromechanical Coupling In Collagen Measured Under Increasing Relative Humidity, Arwa Bazaid, Fengyuan Zhang, Qiancheng Zhang, Sabine Neumayer, Denise Denning, Stefan Habelitz, Ana Marina Ferreira, Brian J. Rodriguez

Articles

The functional role of collagen piezoelectricity has been under debate since the discovery of piezoelectricity in bone in 1957. The possibility that piezoelectricity plays a role in bone remodelling has generated interest in the investigation of this effect in relevant physiological conditions; however, there are conflicting reports as to whether collagen is piezoelectric in a humid environment. In macroscale measurements, the piezoelectricity in hydrated tendon has been shown to be insignificant compared to dehydrated tendon, whereas, at the nanoscale, the piezoelectric effect has been observed in both dry and wet bone using piezo response force microscopy (PFM). In this work, …


Label-Free Quantification Of Nanoencapsulated Piperonyl Esters In Cosmetic Hydrogels Using Raman Spectroscopy, Suha Elderderi, Franck Bonnier, Xavier Perse, Hugh Byrne, Florent Yvergnaux, Igor Chourpa, Abdalla A. Elbashir, Emilie Munnier Jan 2023

Label-Free Quantification Of Nanoencapsulated Piperonyl Esters In Cosmetic Hydrogels Using Raman Spectroscopy, Suha Elderderi, Franck Bonnier, Xavier Perse, Hugh Byrne, Florent Yvergnaux, Igor Chourpa, Abdalla A. Elbashir, Emilie Munnier

Articles

Raman spectroscopy is a well-established technique for the molecular characterisation of samples and does not require extensive pre-analytical processing for complex cosmetic products. As an illustration of its potential, this study investigates the quantitative performance of Raman spectroscopy coupled with partial least squares regression (PLSR) for the analysis of Alginate nanoencapsulated Piperonyl Esters (ANC-PE) incorporated into a hydrogel. A total of 96 ANC-PE samples covering a 0.4% w/w–8.3% w/w PE concentration range have been prepared and analysed. Despite the complex formulation of the sample, the spectral features of the PE can be detected and used to quantify the concentrations. Using …


Cavitation Erosion And Corrosion Resistance Of Hydrophobic Sol-Gel Coatings On Aluminium Alloy, Manasa Hegde, Joseph Mohan, Muhammad Qasim Mushtaq Warraich, Yvonne Kavanagh, Brendan Duffy, Edmond F. Tobin Jan 2023

Cavitation Erosion And Corrosion Resistance Of Hydrophobic Sol-Gel Coatings On Aluminium Alloy, Manasa Hegde, Joseph Mohan, Muhammad Qasim Mushtaq Warraich, Yvonne Kavanagh, Brendan Duffy, Edmond F. Tobin

Articles

Cavitation erosion and erosion-corrosion are the popular failure modes of hydronautics components namely propellers, valves, turbines etc which occurs due to mechanical destructions and electrochemical corrosion. Erosion corrosion is caused due to surge in the number of solid particles affecting the surfaces whereas cavitation erosion is caused due to steady collapse of cavities or bubbles. Aluminium alloys are widely used in marine renewable industries owing to its high strength, light weight and good corrosion resistance. Despite that, cavitation and erosion-corrosion are the limiting factors for these alloys. The aim of the present work is to produce a coating system capable …


Design, Synthesis And Biological Evaluation Of A Novel Bioactive Indane Scaffold 2-(Diphenylmethylene)C-2,3-Dihydro-1h-Inden-1-One With Potential Anticancer Activity, Tao Zhang, Vilmar Bandero, Claire Corcoran, Ismael Obaidi, Manuel Ruether, John O'Brien, Lorraine O'Driscoll, Neil Frankish, Helen Sheridan Jan 2023

Design, Synthesis And Biological Evaluation Of A Novel Bioactive Indane Scaffold 2-(Diphenylmethylene)C-2,3-Dihydro-1h-Inden-1-One With Potential Anticancer Activity, Tao Zhang, Vilmar Bandero, Claire Corcoran, Ismael Obaidi, Manuel Ruether, John O'Brien, Lorraine O'Driscoll, Neil Frankish, Helen Sheridan

Articles

Over the past decades, designing of privileged structures has emerged as a useful approach to the discovery and optimisation of novel biologically active molecules, and many have been successfully exploited across and within different target families. Examples include indole, quinolone, isoquinoline, benzofuran and chromone, etc. In the current study, we focus on synthesising a novel hybrid scaffold constituting naturally occurring benzophenone (14) and indanone (22) ring systems, leading to a general structure of 2-(diphenylmethylene)-2,3-dihydro-1H-inden-1-one (23). It was hypothesised this new hybrid system would provide enhanced anti-cancer activity owing to the presence of the common features associated with the tubulin binding …


Characterization Of Food Chain Clostridioides Difficile Isolates In Terms Of Ribotype And Antimicrobial Resistance, Pilar Marcos, Aoife Doyle, Paul Whyte, Thomas R. Rogers, Maire Mcelroy, Seamus Fanning, Jesus Maria Frias, Declan Bolton Jan 2023

Characterization Of Food Chain Clostridioides Difficile Isolates In Terms Of Ribotype And Antimicrobial Resistance, Pilar Marcos, Aoife Doyle, Paul Whyte, Thomas R. Rogers, Maire Mcelroy, Seamus Fanning, Jesus Maria Frias, Declan Bolton

Articles

The aim of this study was to characterize C. difficile isolates from the farm, abattoir, and retail outlets in Ireland in terms of ribotype and antibiotic resistance (vancomycin, erythromycin, metronidazole, moxifloxacin, clindamycin, and rifampicin) using PCR and E-test methods, respectively. The most common ribotype in all stages of the food chain (including retail foods) was 078 and a variant (RT078/4). Less commonly reported (014/0, 002/1, 049, and 205) and novel (RT530, 547, and 683) ribotypes were also detected, but at lower frequencies. Approximately 72% (26/36 tested) of the isolates tested were resistant to at least one antibiotic, with the majority …


Evaluation Of The Photon Contributions To The Solar Energy Conversion For Organic Luminescent Down-Shifting Liquid Beam Splitters In Hybrid Photovoltaic-Thermal (Pvt) Applications Using Raytracing Monte Carlo Simulations, Kenneth Coldrick Jan 2023

Evaluation Of The Photon Contributions To The Solar Energy Conversion For Organic Luminescent Down-Shifting Liquid Beam Splitters In Hybrid Photovoltaic-Thermal (Pvt) Applications Using Raytracing Monte Carlo Simulations, Kenneth Coldrick

Articles

A hybrid photovoltaic-thermal (PVT) system combines photovoltaic (PV) and photo-thermal (PT) energy collection into a single structure, enhancing the potential to achieve greater solar energy conversion efficiencies. Such enhanced efficiencies can result in greater economic returns and could promote a larger uptake of PVT devices in cold and temperate climate countries. Through the utilization of a Monte Carlo ray-tracing model, this work provides new insights into the optical, electrical, and thermal characteristics of PVT devices. In particular, the work focuses on evaluating the behaviour of novel luminescent imidazole-phenanthroline-based working fluids that were previously experimentally investigated as liquid spectral beam splitters …


Feature Papers In Optical Sensors 2022, Vittorio M. N. Passaro, Yuliya Semenova, Benjamin Miller Jan 2023

Feature Papers In Optical Sensors 2022, Vittorio M. N. Passaro, Yuliya Semenova, Benjamin Miller

Articles

Today, optical sensors are the subject of a very significant number of studies and applications. Many well-established technologies, including free-space optics, integrated photonics, and fiber optics approaches, have been developed in recent decades to fabricate and develop increasingly more efficient optical sensors for applications ranging from industrial control to monitoring the environment, biomedical use, and even as part of the Internet of Things.


Enhancing The Thermo-Optic Tuning Performance Of Whispering Gallery Modes In A Microcapillary Resonator Filled With Nematic Liquid Crystals, Zhe Wang, Arun Kumar Mallik, Fangfang Wei, Zhuochen Wang, Anuradha Rout, Qiang Wu, Yuliya Semenova Jan 2023

Enhancing The Thermo-Optic Tuning Performance Of Whispering Gallery Modes In A Microcapillary Resonator Filled With Nematic Liquid Crystals, Zhe Wang, Arun Kumar Mallik, Fangfang Wei, Zhuochen Wang, Anuradha Rout, Qiang Wu, Yuliya Semenova

Articles

We investigated both theoretically and experimentally, the thermo-optic tuning of whispering-gallery modes (WGMs) in a microcapillary resonator filled with nematic liquid-crystal (LC). The tuning of WGMs was realized due to the photo-thermal effect of magnetic nanoparticles (MNPs) on the surface of a fiber half-taper connected to a pump laser source, resulting in temperature-induced refractive index (RI) changes of the LC material. Based on perturbation theory, we analyzed the influence the RI and the wall thickness on the sensitivity of the proposed tuning scheme. Furthermore, we experimentally demonstrated that increasing the thickness of the MNPs coating on the fiber taper surface …


The Pierce Decomposition And Pierce Embedding Of Endomorphism Rings Of Abelian P-Groups, Brendan Goldsmith, Luigi Salce Jan 2023

The Pierce Decomposition And Pierce Embedding Of Endomorphism Rings Of Abelian P-Groups, Brendan Goldsmith, Luigi Salce

Articles

We prove that more classes of groups than those described by Pierce have the property that the map Ψ is surjective, and we furnish examples of groups which do not have this property. Several results connecting the Pierce decomposition and the Pierce embedding of End(G) are obtained that allow one to derive general conditions on a group G which ensure that the Pierce embedding of End(G) is not surjective.


Modification Of Hyaluronic Acid To Enable Click Chemistry Photo-Crosslinking Of Hydrogels With Tailorable Degradation Profiles, Ciara Buckley Jan 2023

Modification Of Hyaluronic Acid To Enable Click Chemistry Photo-Crosslinking Of Hydrogels With Tailorable Degradation Profiles, Ciara Buckley

Articles

Hyaluronic acid (HA) is a naturally occurring mucopolysaccharide that, due to its inherent bioactivity and extracellular matrix-like structure, has the potential to be utilised extensively in tissue engineering. However, this glycosaminoglycan lacks the properties required for cellular adhesion and photo-crosslinking by UV light, which significantly hinders this polymers applicability. This research presents a method for modifying hyaluronic acid via thiolation and methacrylation to generate a novel photo-crosslinkable polymer with improved physicochemical properties, biocompatibility and the potential to customize biodegradability according to the ratio of monomers used. A decrease in stiffness proportional to increasing thiol concentration was observed when testing the …


The Use Of Transport Time Scales As Indicators Of Pollution Persistence In A Macro-Tidal Setting, Guanghai Gao, John J. O'Sullivan, Aisling Corkery, Zeinab Bedri, Gregory M.P. O'Hare, Wim G. Meijer Jan 2023

The Use Of Transport Time Scales As Indicators Of Pollution Persistence In A Macro-Tidal Setting, Guanghai Gao, John J. O'Sullivan, Aisling Corkery, Zeinab Bedri, Gregory M.P. O'Hare, Wim G. Meijer

Articles

An understanding of water exchange processes is essential for assessing water quality management issues in coastal bays. This paper evaluates the impact of water exchange processes on pollution persistence in a macro-tidal semi-closed coastal bay through two transport time scales (TTS), namely residence time and exposure time. The numerical model was calibrated against field-measured data for various tidal conditions. Simulated current speeds and directions were shown to agree well with the field data. By considering different release scenarios of a conservative tracer by the refinement of an integrated hydrodynamic and solute transport model (the EFDC), the two TTS were used …


Use Of Inner/Outer Sphere Terminology In Electrochemistry—A Hexacyanoferrate Ii/Iii Case Study, John Cassidy, Rafaela Cristina De Carvalho, Tony Betts Jan 2023

Use Of Inner/Outer Sphere Terminology In Electrochemistry—A Hexacyanoferrate Ii/Iii Case Study, John Cassidy, Rafaela Cristina De Carvalho, Tony Betts

Articles

Salts of hexacyanoferrate II/III anions have been widely used as redox couple probe molecules to determine the characteristics of electrode surfaces. Examples include the assessment of electrocatalysts for energy applications and electrocatalysts for the detection of biological or chemical species, as well as the determination of electrochemically active surface areas. An examination of the electrochemical literature, based largely on cyclic voltammetric investigations, reveals a wide range of peak separation and/or heterogeneous electron transfer rate constants, classified sometimes as inner or outer sphere electron transfer processes. Originally developed for the mechanistic interpretation of inorganic transition metal compounds in solution, this terminology …


Finally, It Seems To Be Working – The Evolving Valuation Effect Of The European Union’S Emissions Trading System, Benjamin Lynch, Martha O'Hagan-Luff Jan 2023

Finally, It Seems To Be Working – The Evolving Valuation Effect Of The European Union’S Emissions Trading System, Benjamin Lynch, Martha O'Hagan-Luff

Articles

This research examines the market reaction to the publication of firm-specific environmental news for participating firms in the European Union’s Emissions Trading System (EU ETS) during its third phase. Our sample of 123 publicly listed participating firms, located in 21 European countries, accounted for 45.43% of emissions in the EU ETS in 2020. Using an event study methodology during the period 2014–2021, we find that positive news was rewarded with increased returns for publication events related to the latter years of the phase (2017–2020) while it had an insignificant impact for earlier year (2013–2016). This indicates that the EU ETS …


Assessment Of The Imerg Early-Run Precipitation Estimates Over South American Country Of Chile, Luciana Das Dores De Jesus Da Silva, Mohammed Mahoud, Lisdelys González-Rodríguez, Safa Mohammed, Lien Rodríguez-López, Mauricio Ivan Aguayo Arias Jan 2023

Assessment Of The Imerg Early-Run Precipitation Estimates Over South American Country Of Chile, Luciana Das Dores De Jesus Da Silva, Mohammed Mahoud, Lisdelys González-Rodríguez, Safa Mohammed, Lien Rodríguez-López, Mauricio Ivan Aguayo Arias

Articles

Accurate rainfall measurement is a challenge, especially in regions with diverse climates and complex topography. Thus, knowledge of precipitation patterns requires observational networks with a very high spatial and temporal resolution, which is very difficult to construct in remote areas with complex geological features such as desert areas and mountains, particularly in countries with high topographical variability such as Chile. This study evaluated the performance of the near-real-time Integrated Multi-satellite Retrievals for GPM (IMERG) Early product throughout Chile, a country located in South America between 16°S–66°S latitude. The accuracy of the IMERG Early was assessed at different special and temporal …


Investigation Of Oleic Acid As A Dispersant For Hydroxyapatite Powders For Use In Ceramic Filled Photo-Curable Resins For Stereolithography, Brendan Kennedy, Eamonn De Barra, Stuart Hampshire, Maura Kelleher Jan 2023

Investigation Of Oleic Acid As A Dispersant For Hydroxyapatite Powders For Use In Ceramic Filled Photo-Curable Resins For Stereolithography, Brendan Kennedy, Eamonn De Barra, Stuart Hampshire, Maura Kelleher

Articles

Stereolithography allows production of porous hydroxyapatite scaffolds for bone regeneration but is limited by the challenging rheology of ceramic filled resins. Oleic acid, a natural fatty acid, was applied in concentrations of 0.0–0.3 wt% to improve the rheological properties of HAp resins for the fabrication of solid cylinders and scaffolds by digital light processing (DLP) printing in a wiperless system. Bonding by chemisorption was confirmed by FTIR analysis. The powders were then incorporated into a photo-curable resin of 1–6 hexanediol diacrylate at 18–30 vol%. The shear viscosity and sedimentation rates of photocurable resins containing HAp powder decreased with increasing concentration …


Improving The Angular Visibility Of Photopolymer-Based Reflection Holograms For Sensing Applications, Tatsiana Mikulchyk, Kevin Murphy, John Walsh, Suzanne Martin, Dervil Cody, Izabela Naydenova Jan 2023

Improving The Angular Visibility Of Photopolymer-Based Reflection Holograms For Sensing Applications, Tatsiana Mikulchyk, Kevin Murphy, John Walsh, Suzanne Martin, Dervil Cody, Izabela Naydenova

Articles

Volume reflection hologram-based sensors are designed to visibly change colour in response to a target stressor or analyte. However, reflection holograms fabricated in thick photopolymer films are highly angularly selective, making these sensors challenging to view and interpret by non-experts. Here, the use of speckle holography to improve the visibility of reflection holograms is presented. A novel recording approach combining speckle recording techniques with Denisyuk reflection recording geometry is described. The recorded speckle reflection grating operates as a series of multiplexed reflection gratings with a range of spatial frequencies, capable of reflecting light at a wider range of angles. A …


A Mathematical Model Of Juvenile Delinquency In The New York State, Oluwasegun Micheal Ibrahim Jan 2023

A Mathematical Model Of Juvenile Delinquency In The New York State, Oluwasegun Micheal Ibrahim

Articles

This report presents a mathematical model of juvenile delinquency in the New York State. In particular, we develop a juvenile delinquency system of non-linear differential equations using the mathematical epidemiology framework. In constructing this model, we assume that juvenile delinquency can be studied as a socially infectious disease. The stability of the juvenile delinquency-free equilibrium of the model is examined using the standard non-linear dynamical systems theory technique. We carried out a data fitting based on real-life data from the New York State Criminal Justice Services. The research result reveals that the formulated model conforms with the available data and …


Duality For Spaces Of Polynomials On Tree Spaces, Christopher Boyd, Costas Poulios, Milena Venkova Jan 2023

Duality For Spaces Of Polynomials On Tree Spaces, Christopher Boyd, Costas Poulios, Milena Venkova

Articles

In this paper we study the duality of certain spaces of polynomials on a class of tree spaces. In particular, we are interested in establishing isometric isomorphisms between the spaces of integral and nuclear polynomials and in determining when all polynomials are weakly continuous on bounded sets. This will provide us with new examples of what are known as Q-reflexive spaces.