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Magnetic Field Sensor Based On A Tri-Microfiber Coupler Ring In Magnetic Fluid And A Fiber Bragg Grating, Fangfang Wei, Dejun Liu, Arun Mallik, Gerald Farrell, Qiang Wu, Gang-Ding Peng, Yuliya Semenova Nov 2019

Magnetic Field Sensor Based On A Tri-Microfiber Coupler Ring In Magnetic Fluid And A Fiber Bragg Grating, Fangfang Wei, Dejun Liu, Arun 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 …


Runge–Kutta–Gegenbauer Explicit Methods For Advection-Diffusion Problems, Stephen O'Sullivan Jul 2019

Runge–Kutta–Gegenbauer Explicit Methods For Advection-Diffusion Problems, Stephen O'Sullivan

Articles

In this paper, Runge-Kutta-Gegenbauer (RKG) stability polynomials of arbitrarily high order of accuracy are introduced in closed form. The stability domain of RKG polynomials extends in the the real direction with the square of polynomial degree, and in the imaginary direction as an increasing function of Gegenbauer parameter. Consequently, the polynomials are naturally suited to the construction of high order stabilized Runge-Kutta (SRK) explicit methods for systems of PDEs of mixed hyperbolic-parabolic type.

We present SRK methods composed of L ordered forward Euler stages, with complex-valued stepsizes derived from the roots of RKG stability polynomials of degree $L$. Internal stability …


An Agent-Based Model Of Financial Benchmark Manipulation, Gabriel Virgil Rauterberg, Megan Shearer, Michael Wellman Jun 2019

An Agent-Based Model Of Financial Benchmark Manipulation, Gabriel Virgil Rauterberg, Megan Shearer, Michael Wellman

Articles

Financial benchmarks estimate market values or reference rates used in a wide variety of contexts, but are often calculated from data generated by parties who have incentives to manipulate these benchmarks. Since the the London Interbank Offered Rate (LIBOR) scandal in 2011, market participants, scholars, and regulators have scrutinized financial benchmarks and the ability of traders to manipulate them. We study the impact on market quality and microstructure of manipulating transaction-based benchmarks in a simulated market environment. Our market consists of a single benchmark manipulator with external holdings dependent on the benchmark, and numerous background traders unaffected by the benchmark. …


Can Refactoring Be Self-Affirmed? An Exploratory Study On How Developers Document Their Refactoring Activities In Commit Messages, Eman Abdullah Alomar, Mohamed Wiem Mkaouer, Ali Ouni May 2019

Can Refactoring Be Self-Affirmed? An Exploratory Study On How Developers Document Their Refactoring Activities In Commit Messages, Eman Abdullah Alomar, Mohamed Wiem Mkaouer, Ali Ouni

Articles

Refactoring is a critical task in software maintenance and is usually performed to enforce best design practices, or to cope with design defects. Previous studies heavily rely on defining a set of keywords to identify refactoring commits from a list of general commits extracted from a small set of software
systems. All approaches thus far consider all commits without checking whether refactorings had actually happened or not. In this paper, we aim at exploring how developers document their refactoring activities during the software life cycle. We call such activity Self-Affirmed Refactoring, which is an indication of
the developer-related refactoring events …


On The Impact Of Refactoring On The Relationship Between Quality Attributes And Design Metrics, Mohamed Wiem Mkaouer, Eman Abdullah Alomar, Ali Ouni, Marouane Kessentini May 2019

On The Impact Of Refactoring On The Relationship Between Quality Attributes And Design Metrics, Mohamed Wiem Mkaouer, Eman Abdullah Alomar, Ali Ouni, Marouane Kessentini

Articles

Refactoring is a critical task in software maintenance and is generally performed to enforce the best design and implementation practices or to cope with design defects. Several studies attempted to detect refactoring activities through mining software repositories allowing to collect, analyze and get actionable data-driven insights about refactoring practices within software projects. Aim: We aim at identifying, among the various quality models presented in the literature, the ones that are more in-line with the developer’s vision of quality optimization, when they explicitly mention that they are refactoring to improve them. Method: We extract a large corpus of design-related refactoring activities …


Phase-Only Digital Encryption, Jonathan Blackledge, Western Govere, Dumisani Sibanda May 2019

Phase-Only Digital Encryption, Jonathan Blackledge, Western Govere, Dumisani Sibanda

Articles

Abstract—We study then-dimensional deconvolution prob-lem associated with an impulse response function and an(additive) noise function that are both characterised by thesame phase-only stochastic spectrum. In this case, it is shownthat the deconvolution problem becomes well-posed and has ageneral solution that is both exact and unique, subject to are-normalisation condition relating to the scale of the solution.While the phase-only spectral model considered is of limitedvalue in general (in particular, problems arising in the fieldsof digital signal processing and communications engineering,specifically with regard to the retrieval of information fromnoise), its application to digital cryptography has potential.One of the reasons for this (as …


Examining The Limits Of Predictability Of Human Mobility, Vaibhav Klukarni, Abhijit Mahalunkar, Benoit Garbinato, John D. Kelleher Apr 2019

Examining The Limits Of Predictability Of Human Mobility, Vaibhav Klukarni, Abhijit Mahalunkar, Benoit Garbinato, John D. Kelleher

Articles

We challenge the upper bound of human-mobility predictability that is widely used to corroborate the accuracy of mobility prediction models. We observe that extensions of recurrent-neural network architectures achieve significantly higher prediction accuracy, surpassing this upper bound. Given this discrepancy, the central objective of our work is to show that the methodology behind the estimation of the predictability upper bound is erroneous and identify the reasons behind this discrepancy. In order to explain this anomaly, we shed light on several underlying assumptions that have contributed to this bias. In particular, we highlight the consequences of the assumed Markovian nature of …


An Investigation Of The Detection Capability Of Pulsed Wave Duplex Doppler Of Low Grade Stenosis Using Ultrasound Contrast Agent Microbubbles – An In-Vitro Study, Jacinta Browne, Deirdre King, Andrew Fagan, Deepa Chari, Carmel Moran Apr 2019

An Investigation Of The Detection Capability Of Pulsed Wave Duplex Doppler Of Low Grade Stenosis Using Ultrasound Contrast Agent Microbubbles – An In-Vitro Study, Jacinta Browne, Deirdre King, Andrew Fagan, Deepa Chari, Carmel Moran

Articles

Objective: The objective of the study was to investigate whether clinically used ultrasonic contrast agents improved the accuracy of spectral Doppler ultrasound in the detection of low grade (< 50%) renal artery stenosis. Low grade stenoses in the renal artery are notoriously difficult to reliably detect using Doppler ultrasound due to difficulties such as overlying fat and bowel gas.

Methods: A range of anatomically-realistic renal artery phantoms with varying low degrees of stenosis (0, 30 and 50%) were constructed and peak velocity data was measured from within the pre-stenotic and mid-stenotic regions in each phantom, for both unenhanced and contrast-enhanced spectral Doppler data acquisitions. The effect of a 20mm overlying fat layer on the ultrasound beam distortion and phase aberration, and hence on the measured peak velocity data, was also …


Monitoring Meaningful Activities Using Small Low-Cost Devices In A Smart Home, Jordan Tewell, Dympna O'Sullivan, Neil Maiden, James Lockerbie, Simone Stumpf Apr 2019

Monitoring Meaningful Activities Using Small Low-Cost Devices In A Smart Home, Jordan Tewell, Dympna O'Sullivan, Neil Maiden, James Lockerbie, Simone Stumpf

Articles

A challenge associated with an ageing population is increased demand on health and social care, creating a greater need to enable persons to live independently in their own homes. Ambient assistant living technology aims to address this by monitoring occupants’ ‘activities of daily living’ using smart home sensors to alert caregivers to abnormalities in routine tasks and deteriorations in a person’s ability to care for themselves. However, there has been less focus on using sensing technology to monitor a broader scope of so-called ‘meaningful activities’, which promote a person’s emotional, creative, intellectual, and spiritual needs. In this paper, we describe …


Temperature-Compensated Magnetic Field Sensing With A Dual-Ring Structure Consisting Of Microfiber Coupler-Sagnac Loop And Fiber Bragg Grating - Assisted Resonant Cavity, Fangfang Wei, Dejun Liu, Arun Kumar Mallik, Gerald Farrell, Qiang Wu, Gang-Ding Peng, Yuliya Semenova Mar 2019

Temperature-Compensated Magnetic Field Sensing With A Dual-Ring Structure Consisting Of Microfiber Coupler-Sagnac Loop And Fiber Bragg Grating - Assisted Resonant Cavity, Fangfang Wei, Dejun Liu, Arun Kumar Mallik, Gerald Farrell, Qiang Wu, Gang-Ding Peng, Yuliya Semenova

Articles

A novel temperature-compensated magnetic field sensor based on a ring erbium-doped fiber laser combined with a fiber Bragg grating (FBG) and a Sagnac loop containing a microfiber coupler (MFC) and magnetic fluid is proposed and investigated. Thanks to the dual-ring structure of the MFC-Sagnac loop and the FBG-assisted resonant cavity, the output of the structure has two distinct laser peaks. In addition to the magnetic field sensing capability, the proposed structure can simultaneously provide temperature information. The maximum experimentally demonstrated sensitivity to a magnetic field determined from the spectral shift of one laser peak is 102 pm/mT in the magnetic …


A U-Net Deep Learning Framework For High Performance Vessel Segmentation In Paitents With Cerebrovascular Disease, Michelle Livne, Jana Rieger, Orhun Utku Aydin, Abdel Aziz Taha, Ela Maria Akay, Tabea Kossen, Jan Sobesky, John D. Kelleher, Kristian Hildebrand, Dietmar Frey, Vince I. Madai Feb 2019

A U-Net Deep Learning Framework For High Performance Vessel Segmentation In Paitents With Cerebrovascular Disease, Michelle Livne, Jana Rieger, Orhun Utku Aydin, Abdel Aziz Taha, Ela Maria Akay, Tabea Kossen, Jan Sobesky, John D. Kelleher, Kristian Hildebrand, Dietmar Frey, Vince I. Madai

Articles

Brain vessel status is a promising biomarker for better prevention and treatment in cerebrovascular disease. However, classic rule-based vessel segmentation algorithms need to be hand-crafted and are insufficiently validated. A specialized deep learning method—the U-net—is a promising alternative. Using labeled data from 66 patients with cerebrovascular disease, the U-net framework was optimized and evaluated with three metrics: Dice coefficient, 95% Hausdorff distance (95HD) and average Hausdorff distance (AVD). The model performance was compared with the traditional segmentation method of graph-cuts. Training and reconstruction was performed using 2D patches. A full and a reduced architecture with less parameters were trained. We …


Sustainable Energy Governance In South Tyrol (Italy): A Probabilistic Bipartite Network Model, Jessica Belest, Laura Secco, Elena Pisani, Alberto Caimo Feb 2019

Sustainable Energy Governance In South Tyrol (Italy): A Probabilistic Bipartite Network Model, Jessica Belest, Laura Secco, Elena Pisani, Alberto Caimo

Articles

At the national scale, almost all of the European countries have already achieved energy transition targets, while at the regional and local scales, there is still some potential to further push sustainable energy transitions. Regions and localities have the support of political, social, and economic actors who make decisions for meeting existing social, environmental and economic needs recognising local specificities.

These actors compose the sustainable energy governance that is fundamental to effectively plan and manage energy resources. In collaborative relationships, these actors share, save, and protect several kinds of resources, thereby making energy transitions deeper and more effective.

This research …


Automatic Acquisition Of Annotated Training Corpora For Test-Code Generation, Magdalena Kacmajor, John D. Kelleher Feb 2019

Automatic Acquisition Of Annotated Training Corpora For Test-Code Generation, Magdalena Kacmajor, John D. Kelleher

Articles

Open software repositories make large amounts of source code publicly available. Potentially, this source code could be used as training data to develop new, machine learning-based programming tools. For many applications, however, raw code scraped from online repositories does not constitute an adequate training dataset. Building on the recent and rapid improvements in machine translation (MT), one possibly very interesting application is code generation from natural language descriptions. One of the bottlenecks in developing these MT-inspired systems is the acquisition of parallel text-code corpora required for training code-generative models. This paper addresses the problem of automatically synthetizing parallel text-code corpora …


Use Of Novel Anthropomorphic Breast Ultrasound Phantoms For Radiology Resident Education, Jacinta Browne, Chris Gu, Robert Fazzio, Andrew Fagan, Donald Tradup, Nicholas Hangiandreou Feb 2019

Use Of Novel Anthropomorphic Breast Ultrasound Phantoms For Radiology Resident Education, Jacinta Browne, Chris Gu, Robert Fazzio, Andrew Fagan, Donald Tradup, Nicholas Hangiandreou

Articles

Purpose: This study evaluated the training and assessment role of anthropomorphic breast ultrasound phantoms which simulated both the morphological and sonographic characteristics of breast tissue, including lesions, in a group of radiology residents at a large academic medical center. Methods: This was a prospective study involving 9 residents across all years (2nd–4th year) of a radiology residency program. Baseline assessments of all residents ability to detect and characterize lesions in P-I were carried out, followed by a two-hour teaching session on the same phantom. All residents underwent a post-training, final assessment on P-II to evaluate changes in …


Urban Aerobiological Risk Mapping Of Ornamental Trees Using A New Index Based On Lidar And Kriging: A Case Study Of Plane Trees, Raúl Pecero-Casimiro, Santiago Fernández-Rodríguez, Rafael Tormo-Molina, Alejandro Monroy-Colín, Inmaculada Silva-Palacios, Juan Pedro Cortés-Pérez, Ángela Gonzalo-Garijo, J. M. Maya-Manzano Jan 2019

Urban Aerobiological Risk Mapping Of Ornamental Trees Using A New Index Based On Lidar And Kriging: A Case Study Of Plane Trees, Raúl Pecero-Casimiro, Santiago Fernández-Rodríguez, Rafael Tormo-Molina, Alejandro Monroy-Colín, Inmaculada Silva-Palacios, Juan Pedro Cortés-Pérez, Ángela Gonzalo-Garijo, J. M. Maya-Manzano

Articles

Ornamental trees bring benefits for human health, including reducing urban pollution. However, some species, such as plane trees (Platanus sp.), produce allergenic pollen. Consequently, urban maps are a valuable tool for allergic patients and allergists, but they often fail to include variables that contribute to the “building downwash effect”, such as the width and shape of streets and the height of buildings. Other factors that directly influence pollen dispersion (slopes and other geographical features) also have not traditionally been discussed. The LiDAR (Laser Imaging Detection and Ranging) technique enables one to consider these variables with high accuracy. This work proposes …


Predicted Temperature-Increase-Induced Global Health Burden And Its Regional Variability, Jae Young Lee, Ho Kim, Antonio Gasparrini, Ben Armstrong, Michelle L. Bell, Franceso Sera, Eric Lavingne, Rosana Abrutzky, Shilu Tong, Micheline De Sousa Zanotti Stagliorio Coelho, Paulo Hilario Nascimento Saldiva, Patricia Matus Correa, Nicolas Valdes Ortega, Haidong Kan, Samule Osorio Garcia, Jan Kysely, Ales Urban, Hans Orru, Ene Indermitte, Jouni J.K. Jaakkola, Niilo R.I. Ryti, Mathilde Pascal, Patrick J. Goodman, Ariana Zeka, Paolo Michelozzi, Matteo Scortichini, Masahiro Hashizume, Yasushi Honda, Magali Hurtado, Julio Cruz, Xerxes Seposo, Balthazar Nunes, Joao Paulo Teixeira, Aurelio Tobias, Carmen Iniguez, Bertil Forsberg, Christofer Astrom, Ana Maria Vicedo-Cabrera, Martina S. Ragettli, Yeu-Liang Leon Guo, Bing-Yu Chen, Antonella Zanobetti, Joel Schwartz, Tran Ngoc Dang, Dung Do Van, Fetemeh Mayvaneh, Ala Overcenco, Shanshan Li, Yuming Guo Jan 2019

Predicted Temperature-Increase-Induced Global Health Burden And Its Regional Variability, Jae Young Lee, Ho Kim, Antonio Gasparrini, Ben Armstrong, Michelle L. Bell, Franceso Sera, Eric Lavingne, Rosana Abrutzky, Shilu Tong, Micheline De Sousa Zanotti Stagliorio Coelho, Paulo Hilario Nascimento Saldiva, Patricia Matus Correa, Nicolas Valdes Ortega, Haidong Kan, Samule Osorio Garcia, Jan Kysely, Ales Urban, Hans Orru, Ene Indermitte, Jouni J.K. Jaakkola, Niilo R.I. Ryti, Mathilde Pascal, Patrick J. Goodman, Ariana Zeka, Paolo Michelozzi, Matteo Scortichini, Masahiro Hashizume, Yasushi Honda, Magali Hurtado, Julio Cruz, Xerxes Seposo, Balthazar Nunes, Joao Paulo Teixeira, Aurelio Tobias, Carmen Iniguez, Bertil Forsberg, Christofer Astrom, Ana Maria Vicedo-Cabrera, Martina S. Ragettli, Yeu-Liang Leon Guo, Bing-Yu Chen, Antonella Zanobetti, Joel Schwartz, Tran Ngoc Dang, Dung Do Van, Fetemeh Mayvaneh, Ala Overcenco, Shanshan Li, Yuming Guo

Articles

An increase in the global health burden of temperature was projected for 459 locations in 28 countries worldwide under four representative concentration pathway scenarios until 2099. We determined that the amount of temperature increase for each 100 ppm increase in global CO2 concentrations is nearly constant, regardless of climate scenarios. The overall average temperature increase during 2010–2099 is largest in Canada (1.16 °C/100 ppm) and Finland (1.14 °C/100 ppm), while it is smallest in Ireland (0.62 °C/100 ppm) and Argentina (0.63 °C/100 ppm). In addition, for each 1 °C temperature increase, the amount of excess mortality is increased largely in …


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 Jan 2019

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 …


Nanomole Silver Detection In Chloride-Free Phosphate Buffer Using Platinum And Gold Micro- And Nanoelectrodes, Prabhakar Sidambaram, John Colleran Jan 2019

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) …


Improving Extraction Processes Of Crustacean Chitin Using Solid State Analytical Techniques, Fionn O'Fearghail, Michelle Giltrap, Christine O'Connor, Patrice Behan Jan 2019

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 …


Self-Cleaning Hydrophobic Nanocoating On Glass: A Scalable Manufacturing Process, Surendra Maharjan, Kang-Shyang Liao, Alexander J. Wang, Killian Barton, Amrita Haldar, Nigel J. Alley, Hugh Byrne, Seamus A. Curran Jan 2019

Self-Cleaning Hydrophobic Nanocoating On Glass: A Scalable Manufacturing Process, Surendra Maharjan, Kang-Shyang Liao, Alexander J. Wang, Killian Barton, Amrita Haldar, Nigel J. Alley, Hugh Byrne, Seamus A. Curran

Articles

A method of forming a self-cleaning hydrophobic coating (SCHN) on glass substrates utilizing a scalable manufacturing process is described. The process initiates with roughening of planar glass surfaces using diamond micro-/nano-particle abrasives, which creates microscopic tortuous grooves. After cleaning the substrates, the roughened surface is vapor deposited with trichloro(1H,1H,2H,2H-perfluorooctyl)silane (TCPFOS) under enclosure with controlled humidity. TCPFOS chemically binds with the substrate via covalent linkage. Due to the greatly reduced surface tension between water and the self-cleaning surface, the water droplet slides down leaving no trail (sliding angle of 14° for 0.1 mL water droplet). Due to the reduced adhesion of …


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 Jan 2019

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 …


Raman Spectroscopy As A Potential Tool For Label Free Therapeutic Drug Monitoring In Human Serum: The Case Of Busulfan And Methotrexate, Drishya Parachalil, Franck Bonnier, Deirdre Commerford, Igor Chourpa, Jennifer Mcintyre, Hugh Byrne Jan 2019

Raman Spectroscopy As A Potential Tool For Label Free Therapeutic Drug Monitoring In Human Serum: The Case Of Busulfan And Methotrexate, Drishya Parachalil, Franck Bonnier, Deirdre Commerford, Igor Chourpa, Jennifer Mcintyre, Hugh Byrne

Articles

A methodology is proposed, based on Raman spectroscopy coupled with multivariate analysis, to determine the Limit of Detection (LOD) and Limit of Quantification (LOQ) for therapeutic drug monitoring in human serum, using the examples of Busulfan, a cell cycle non-specific alkylating antineoplastic agent, and, Methotrexate, a chemotherapeutic agent and immune system suppressant. In this study, ultrafiltration is employed to fractionate spiked human pooled serum to efficiently recover the drug in the filtrate prior to performing Raman analysis. The drug concentration ranges were chosen to encompass the recommended therapeutic ranges and toxic levels in patients. Raman spectra were collected from the …


On The Use Of Vibrational Spectroscopy And Scanning Electron Microscopy To Study Phenolic Extractability Of Cooperage Byproducts In Wine, Berta Baca‑Bocanegra, Julio Nogales‑Bueno, Brian Gorey, Francisco José Heredia, Hugh Byrne, José Miguel Hernández‑Hierro Jan 2019

On The Use Of Vibrational Spectroscopy And Scanning Electron Microscopy To Study Phenolic Extractability Of Cooperage Byproducts In Wine, Berta Baca‑Bocanegra, Julio Nogales‑Bueno, Brian Gorey, Francisco José Heredia, Hugh Byrne, José Miguel Hernández‑Hierro

Articles

Wood is an important source of phenolic compounds, which can be transferred to wine during aging process, improving its properties, from an organoleptic point of view. Therefore, understanding and optimizing the extractability of phenolic compounds from wood are crucial in the oenological field. The structural composition of oak wood samples has been evaluated using Raman and attenuated total reflectance Fourier transform infrared (ATR–FTIR) spectroscopies, and their main spectral features have been linked to phenolic compound extractabilities, as measured by classic chemical analyses. To support the analysis, microscopic images of the samples were also recorded using scanning electron microscopy (SEM). The …


Third-Order Optical Nonlinearity Properties Of Cdcl2-Modifed Ge–Sb–S Chalcogenide Glasses, Xiaosong Lu, Jianhui Li, Lu Yang, Runan Zhang, Yindong Zhang, Jing Ren, Aurelian Catalin Galca, Mihail Secu, Gerald Farrell, Pengfei Wang Jan 2019

Third-Order Optical Nonlinearity Properties Of Cdcl2-Modifed Ge–Sb–S Chalcogenide Glasses, Xiaosong Lu, Jianhui Li, Lu Yang, Runan Zhang, Yindong Zhang, Jing Ren, Aurelian Catalin Galca, Mihail Secu, Gerald Farrell, Pengfei Wang

Articles

We developed a new type of chalcohalide glasses with physicochemical and nonlinear optical properties that are tunable by composition. It is found that more than 60 mol.% CdCl2 heavy metal halide can be dissolved into the ternary Ge–Sb–S system and forming stable glasses. The visible-light transparency range is extended to shorter wavelengths with the addition of CdCl2, which is beneficial for the optical quality control and infra-red (IR) system alignment. The third-order optical nonlinearity (TONL) is studied using the femtosecond Z-scan method. The results show that both the nonlinear refractive index and two photon absorption co-efficient decrease with CdCl2. Benefiting …


A Twelve-Wavelength Thulium-Doped Fibre Laser Based On A Microfibre Coil Resonator Incorporating Black Phosphorus, Shi Li, Yu Yin, Elfed Lewis, Gerald Farrell, Pengfei Wang Jan 2019

A Twelve-Wavelength Thulium-Doped Fibre Laser Based On A Microfibre Coil Resonator Incorporating Black Phosphorus, Shi Li, Yu Yin, Elfed Lewis, Gerald Farrell, Pengfei Wang

Articles

A novel multi-wavelength continuous Thulium-doped fibre laser incorporating a microfibre coil resonator based on black phosphorus (MCR-BP) material has been successfully fabricated and demonstrated. A twelve-wavelength spectrum with 0.54 nm channel spacing has been achieved by simply adjusting the pump source power. A single peak extinction ratio of more than 40 dB was observed. The superior performance of the MCR-BP described in this article compared to conventional MCR based fibre lasers can be attributed the inclusion of the Black Phosphorous Material. The enhanced lasing is primarily due to the twin properties of the MCR-BP device combining a comb-like filter effect …


All Fibre Q-Switched Thulium-Doped Fibre Laser Incorporating Thulium–Holmium Co-Doped Fibre As A Saturable Absorber, Shi Li, Elfed Lewis, Gerald Farrell, Ahmad Haziq Aiman Rosol, A.A. Latiff, Sulaiman Wadi Harun, Bingang Guo, Pengfei Wang Jan 2019

All Fibre Q-Switched Thulium-Doped Fibre Laser Incorporating Thulium–Holmium Co-Doped Fibre As A Saturable Absorber, Shi Li, Elfed Lewis, Gerald Farrell, Ahmad Haziq Aiman Rosol, A.A. Latiff, Sulaiman Wadi Harun, Bingang Guo, Pengfei Wang

Articles

A novel all fibre Q-switched Thulium-doped fibre laser (TDFL) is reported which includes a short length of a Thulium–Holmiumco-doped fibre (THDF) as a saturable absorber. A high repetition rate (27.26 kHz) coupled with a low pulse width (19.06μs) is obtained for single wavelength Q-switched pulse operation at an output wavelength of 1911.5 nm using a pump power of 200 mW. Increasing the pump power from 200 mW to 700 mW results in the repetition rate increasing from 27.26 kHz to 99.67 kHz and the pulse width decreasing from 19.06μs to 920 ns. The centre wavelength of the single Q-switched pulse …


Distribution Of Tm 3+ And Ni 2+ In Chalcogenide Glass Ceramics Containing Ga2s3 Nanocrystals: Influence On Photoluminescence Properties, Xiaosong Lu, Zhiqiang Lai, Jing Ren, Lukas Strizik, Tomas Wagner, Yanqiu Du, Gerald Farrell, Pengfei Wang Jan 2019

Distribution Of Tm 3+ And Ni 2+ In Chalcogenide Glass Ceramics Containing Ga2s3 Nanocrystals: Influence On Photoluminescence Properties, Xiaosong Lu, Zhiqiang Lai, Jing Ren, Lukas Strizik, Tomas Wagner, Yanqiu Du, Gerald Farrell, Pengfei Wang

Articles

The distribution of Tm3+ and Ni2+ ions is unambiguously exhibited in 80GeS2-20Ga2S3 chalcogenide glass ceramics (GCs) containing Ga2S3 nanocrystals (NCs) by using advanced analytical transmission electron microscopy. Distinctively different distribution patterns of Tm3+ and Ni2+ ions are observed in the GCs obtained by controlled crystallization. The distribution of the dopants imposes strong influence on their optical properties which are revealed by absorption and photoluminescence (PL) spectra. Detailed discussions are given of the mechanisms of the crystallization-induced PL enhancement and quenching of the Tm3+ mid-infrared and Ni2+ near-infrared emissions, respectively.


In-Fiber Temperature Sensor Based On Green Up-Conversion Luminescence In An Er3+-Yb3+ Co-Doped Tellurite Glass Microsphere, Meng Zhang, Angzhen Li, Jibo Yu, Xiaosong Lu, Shunbin Wang, Elfed Lewis, Gerald Farrell, Libo Yuan, Pengfei Wang Jan 2019

In-Fiber Temperature Sensor Based On Green Up-Conversion Luminescence In An Er3+-Yb3+ Co-Doped Tellurite Glass Microsphere, Meng Zhang, Angzhen Li, Jibo Yu, Xiaosong Lu, Shunbin Wang, Elfed Lewis, Gerald Farrell, Libo Yuan, Pengfei Wang

Articles

A novel, to the best of our knowledge, in-fiber temperature sensor based on green up-conversion (UC) luminescence in an Er3+-Yb3+" role="presentation" style="box-sizing: border-box; display: inline; font-size: 12.88px; line-height: normal; word-spacing: normal; overflow-wrap: normal; white-space: nowrap; float: none; direction: ltr; max-width: none; max-height: none; min-width: 0px; min-height: 0px; border: 0px; padding: 0px; margin: 0px; position: relative;">Er3+-Yb3+Er3+-Yb3+ co-doped tellurite glass microsphere is described. The tellurite glass microsphere is located firmly inside a suspended tri-core hollow-fiber (STCHF) structure. The pump light launched via a single-mode fiber (SMF) is passed through a section of multimode fiber, which is fusion spliced between the SMF …


Ultrabroadband Mid-Infrared Emission From Cr 2+ -Doped Infrared Transparent Chalcogenide Glass Ceramics Embedded With Thermally Grown Zns Nanorods, Xiaosong Lu, Zhiqiang Lai, Runan Zhang, Haitao Guo, Jing Ren, Lukas Strizik, Tomas Wagner, Gerald Farrell, Pengfei Wang Jan 2019

Ultrabroadband Mid-Infrared Emission From Cr 2+ -Doped Infrared Transparent Chalcogenide Glass Ceramics Embedded With Thermally Grown Zns Nanorods, Xiaosong Lu, Zhiqiang Lai, Runan Zhang, Haitao Guo, Jing Ren, Lukas Strizik, Tomas Wagner, Gerald Farrell, Pengfei Wang

Articles

We report, for the first time to our knowledge, an ultrabroadband mid-infrared (MIR) emission in the range of 1800–2800 nm at room temperature from a Cr2+-doped chalcogenide glass ceramic embedded with pure hexagonal (wurtzite) β-ZnS nanorods and study the emission-dependent properties on the doping concentration of Cr2+. A new family of chalcogenide glasses based on (100 − x) Ge1.5As2S6.5 – x ZnSe (in mol.%) was prepared by melt-quenching method. The Cr2+: β-ZnS nanorods of ˜150 nm in diameter and ˜1 μm in length were grown in the Cr2+-doped glass after thermal annealing. The compositional variations of glass structures and optical …


(E)-6,6′-(Diazene-1,2-Di­Yl)Bis­(1,10-Phenanthrolin-5-Ol) Tri­Chloro­Methane Disolvate: A Superconjugated Ligand, Muhib Ahmed, Michael Devereux, Vickie Mckee, Malachy Mccann, A. Denise Rooney Jan 2019

(E)-6,6′-(Diazene-1,2-Di­Yl)Bis­(1,10-Phenanthrolin-5-Ol) Tri­Chloro­Methane Disolvate: A Superconjugated Ligand, Muhib Ahmed, Michael Devereux, Vickie Mckee, Malachy Mccann, A. Denise Rooney

Articles

Phenanthroline ligands are important metal-binding mol­ecules which have been extensively researched for applications in both material science and medicinal chemistry. Azo­benzene and its derivatives have received significant attention because of their ability to be reversibly switched between the E and Z forms and so could have applications in optical memory and logic devices or as mol­ecular machines. Herein we report the formation and crystal structure of a highly unusual novel diazo-diphenanthroline compound, C24H14N6O2·2CHCl3.